ALKALI-SILICAREACTION INPORTLAND CEMENTCONCRETE:TESTING METHODSANDMITIGATIONALTERNATIVES
RESEARCH REPORT ICAR - 301-1f
Sponsored by the Aggregates Foundation
for Technology, Research and Education
1
Technical Report Documentation Page
1. Report No. ICAR 301-1F
2. Government Accession No. 3. Recipient’s Catalog No.
5. Report Date July 2001
4. Title and Subtitle ALKALI-SILICA REACTION IN PORTLAND CEMENT CONCRETE:
TESTING METHODS AND MITIGATION ALTERNATIVES 6. Performing Organization Code
7. Author(s) Wissam E. Touma, David F. Fowler, Ramon L. Carrasquillo
8. Performing Organization Report No. Research Report ICAR 301-1F
10. Work Unit No. (TRAIS) 9. Performing Organization Name and Address International Center for Aggregates Research The University of Texas at Austin Cockrell Hall 5.200 Austin, TX 78712-1076
11. Contract or Grant No. Project No. ICAR-301
13. Type of Report and Period Covered Research Report January 1998-December 2000
12. Sponsoring Agency Name and Address Aggregates Foundation for Technology, Research, and Education c/o National Sand, Stone, and Gravel Association 2101 Wilson Boulevard, Suite 100 Arlington, VA 22201 14. Sponsoring Agency Code
15. Supplementary Notes Research performed in cooperation with the Aggregates Foundation for Technology, Research, and Education. Research Project Title: Alkali-Silica Reaction in Portland Cement Concrete
16. Abstract Identifying the susceptibility of an aggregate to alkali-silica reaction (ASR) before using it in concrete is one of the most efficient practices for preventing damage and failure. Several tests have been developed for identifying aggregates subject to ASR, but each has its limitations. A three-year research study was initiated on January 1, 1998 at The University of Texas at Austin for investigating ASR in portland cement concrete. The scope of the study was essentially three fold: (1) investigate the predictive ability of ASTM C 1260 and C 1293, (2) develop more accurate and more efficient modifications of these procedures, and (3) investigate ASR mitigation alternatives. Aggregate samples from 14 sources from around the United States were acquired for the investigation. Aggregates were used in an extensive testing program during which guidelines for predicting the potential ASR of aggregates were developed and recommendations for minimizing concrete damage due to ASR were formulated. This report includes a review of the state-of-the-art of ASR, an evaluation of testing protocols and recommendations for dramatically shortening test time, test results, and mitigation options.
17. Key Words Alkali-Silica Reaction, Testing Procedures, Aggregates, ASTM C 1293, Concrete Testing, Mitigation Alternatives, Fly Ash, Silica Fume, Granulated Slag, Calcined Clay, Lithium Nitrate, Cement
18. Distribution Statement No restrictions
19. Security Classif. (of report) Unclassified
20. Security Classif. (of this page) Unclassified
21. No. of pages 520
22. Price
ALKALI-SILICA REACTION IN PORTLAND CEMENT CONCRETE: TESTING METHODS AND MITIGATION ALTERNATIVES
by
Wissam Touma, Ph.D.
Civil Engineering Department The University of Texas at Austin
David Fowler, Ph.D., P.E.
Civil Engineering Department The University of Texas at Austin
and
Ramon Carrasquillo, Ph.D., P.E. Civil Engineering Department
The University of Texas at Austin
Research Report ICAR 301-1F Research Project Number ICAR-301
Research Project Title Alkali-Silica Reaction in Portland Cement Concrete
Sponsored by the Aggregates Foundation for Technology, Research, and Education
July 2001
International Center for Aggregates Research The University of Texas at Austin
Austin, Texas 78712 and
Texas A &M University College Station, Texas 77843
DISCLAIMER
The contents of this report reflect the view of the authors who are responsible for the facts and accuracy of the data presented therein. The contents do not necessarily reflect the views of policies of the International Center for Aggregates Research (ICAR). This report does not constitute a standard, specification, or regulation.
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ACKNOWLEDGEMENTS
This is the final report of the Aggregates Foundation for Technology, Research, and Education Research Project 301 titled Alkali-Silica Reaction in Portland Cement Concrete. This research project was conducted at The University of Texas at Austin. This report is a product of the combined efforts of many. Norman R. Nelson of Lyman-Richey Sand and Gravel Company, Chair of both Task Force Three of the International Center for Aggregates Research (ICAR) entitled “Alkali-Silica/Alkali-Carbonate Reaction in Portland Cement Concrete” and Project 301’s Advisory Panel provided invaluable assistance. The authors would also like to commend the sterling efforts of the other advisory panelists and task force members. In addition, the authors are grateful to the Aggregates Foundation for Technology, Research, and Education and the National Stone, Sand, and Gravel Association for sponsoring this research through ICAR. Finally, the authors would also like to thank the organizations that contributed materials to this study.
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TABLE OF CONTENTS
Chapter 1 – Introduction
Chapter 2 – Alkali-Silica Reaction Mechanisms
Chapter 3 – Review of Selective Research
Chapter 4 – Review of International Experience with ASR
Chapter 5 – Testing Materials
Chapter 6 – Laboratory Testing Procedures
Chapter 7 – Mixture Proportions
Chapter 8 – Miscellaneous Testing Results
Chapter 9 – ASTM C 1260 Results and Discussion
Chapter 10 – ASTM C 1293 Results and Discussion
Chapter 11 – Investigation of Mitigation Alternatives Using ASTM C 1260
Chapter 12 – Investigation of Mitigation Alternatives Using ASTM C 1293
Chapter 13 – Comparison Between C 1260, C 1293, Petrographic Analysis, and Field Investigation
Results
Chapter 14 – Guidelines and Recommendations
Chapter 15 – Summary of Conclusions
Appendix A – Effect of Changing the Curing Solution Molarity on the Results of ASTM C 1260
Appendix B – Variables for the K-A-M-J Model using C 1260 Expansions Up to 28 Days
Appendix C – Effective Levels of Cement Replacement with Class C Fly Ash, Class F Fly Ash, and Silica Fume Appendix D – Petrographic Analysis and Field Performance Documentation of Aggregates
Appendix E – Petrographic Examination of Mortar Bars After Being Tested in Accordance with ASTM C
1260
References
TABLE OF CONTENTS
Chapter Page
CHAPTER ONE - INTRODUCTION 1.1 GENERAL ............................................................................................. 1 1.2 BACKGROUND AND PROJECT JUSTIFICATION ............................................ 1 1.2.1 ASR Survey..................................................................................................... 1 1.2.2 Testing Procedures ......................................................................................... 3 1.2.3 Mitigation Alternatives ................................................................................... 5 1.3 PROJECT OBJECTIVE .......................................................................................... 6 1.4 WORK PLAN .......................................................................................................... 7 1.5 BENEFITS .............................................................................................................. 9 CHAPTER TWO – ALKALI-SILICA REACTION MECHANISMS 2.1 GENERAL DEFINITION ..................................................................................... 11 2.2 CONTRIBUTION OF THE SILICA TO THE REACTION ................................. 12 2.3 ALKALI CONTRIBUTION TO THE REACTION …….……………………...14 CHAPTER THREE – REVIEW OF SELECTIVE RESEARCH 3.1 INTRODUCTION ............................................................................................... 16 3.2 TESTING FOR POTENTIAL REACTIVITY OF AGGREGATES ................... 16 3.2.1 Petrographic Examination: ASTM C 295 .................................................. 17 3.2.2 Chemical Method: ASTM C 289 .............................................................. 18 3.2.3 Mortar-Bar Method: ASTM C 227 ............................................................ 18 3.2.4 Accelerated Mortar-Bar Method: ASTM C 1260 ...................................... 21 3.2.5 Autoclave Mortar-Bar Methods ................................................................. 22 3.2.6 Concrete Prism Method: CAN/CSA-A23.2-14A (ASTM C 1293) ............ 23 3.2.7 Accelerated Concrete Prism Method (Used in Quebec) ............................. 24 3.2.8 The Duggan Test ....................................................................................... 24 3.2.9 Conclusions of the Survey by Fournier and Bérubé ................................... 24 3.3 ASR MITIGATION MEASURES ...................................................................... 27 3.3.1 Minimizing Alkalis ..................................................................................... 29 3.3.2 Effectiveness of Supplementary Cementious Materials ............................ 30 3.3.3 Control Mechanisms of Supplementary Cementitious Materials ............... 57 3.4 FINAL REMARKS ............................................................................................. 59 CHAPTER FOUR – REVIEW OF INTERNATIONAL EXPERIENCE WITH ASR 4.1 INTRODUCTION ................................................................................................ 60 4.2 RILEM SURVEY ................................................................................................. 60 4.2.1 Specific RILEM Survey Conclusions Related to Testing ........................... 62 4.3 ASR IN AUSTRALIA .......................................................................................... 63 4.3.1 Evaluating the Reactivity of Aggregates ..................................................... 63 4.3.2 ASR Preventive Measures ........................................................................... 68 4.4 ASR IN CHINA ..................................................................................................... 69
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4.6.1 Evaluating the Reactivity of Aggregates ..................................................... 70 4.6.2 ASR Preventive Measures ........................................................................... 70 4.6.3 ASR in Beijing ............................................................................................ 70 4.5 ASR IN CANADA ............................................................................................... 71 4.5.1 Evaluating the Reactivity of Aggregates ..................................................... 71 4.5.1.1 “Testing Concrete for AAR in NaOH and NaCl Solutions at 380C and 800C” ............................................................................ 71 4.5.1.2 “Effectiveness of High-Volume Fly Ash Concrete in Controlling Expansion Due to Alkali-Silica Reaction” ..................................... 72 4.5.1.3 Inter-Laboratory Test Evaluation ....................................................... 77 4.5.2 ASR Preventive Measures ........................................................................... 78 4.5.2.1 Field Performance .............................................................................. 78 4.5.2.2 Laboratory Studies ............................................................................. 79 4.5.2.3 Preventive Measures .......................................................................... 80 4.6 ASR IN DENMARK ............................................................................................ 81 4.6.1 Alkali Content of the Concrete .................................................................... 82 4.6.2 Environmental Classification ...................................................................... 82 4.6.3 Aggregate Specification .............................................................................. 82 4.6.4 Concrete Specification ................................................................................ 83 4.7 ASR IN FRANCE ................................................................................................. 84 4.7.1 Evaluating the Reactivity of Aggregates ..................................................... 87 4.7.2 ASR Preventive Measures ........................................................................... 87 4.7.2.1 Alkali Content of the Concrete .......................................................... 89 4.7.2.2 Acceptable Level of Risk and Environmental Conditions ................. 89 4.8 ASR IN THE NETHERLANDS ........................................................................... 94 4.8.1 Evaluating the Reactivity of Aggregates ..................................................... 95 4.8.2 ASR Preventive Measures ........................................................................... 95 4.9 ASR IN KOREA ................................................................................................... 96 4.10 ASR IN NORWAY ............................................................................................. 96 4.10.1 Evaluating the Reactivity of Aggregates ................................................... 96 4.10.1.1 Petrographic Analysis ...................................................................... 97 4.10.1.2 NBRI Accelerated Mortar-Bar Test (C 1260) .................................. 97 4.10.1.3 The Concrete-Prism Test ................................................................. 98 4.10.1.4 Testing Protocol ............................................................................... 98 4.10.2 ASR Preventive Measures ......................................................................... 98 4.11 ASR IN PORTUGAL ......................................................................................... 98 4.12 ASR IN NEW ZEALAND .................................................................................. 99 4.13 ASR IN HONG KONG .................................................................................... 100 4.14 ASR IN TAIWAN ............................................................................................ 100 4.15 ASR IN ITALY ................................................................................................ 101 4.16 ASR IN ICELAND ........................................................................................... 102 4.17 ASR IN THE UNITED KINGDOM................................................................... 102 4.18 ASR IN THE UNITED STATES OF AMERICA ............................................ 106
4.18.1 DOT Survey ............................................................................................ 106 4.18.2 Strategic Highway Research Program (SHRP) ....................................... 106 4.18.3 ASR in North Carolina............................................................................. 112
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4.18.4 ASR in Virginia........................................................................................ 112 4.18.5 ASR in South Dakota (Polynomial and Avrami) .................................... 114 4.18.6 Mid-Atlantic Regional Technical Committee .......................................... 115 4.18.7 AASHTO ASR Lead State Team............................................................. 117 4.18.8 Portland Cement Association ................................................................... 118 4.18.9 The National Aggregates Association ...................................................... 118 4.18.10 Lithium as a Preventive Measure ........................................................... 120
4.20 FINAL REMARKS ........................................................................................... 122 CHAPTER FIVE – TESTING MATERIALS 5.1 AGGREGATE SELECTION ............................................................................. 123 5.2 OTHER TESTING MATERIALS ...................................................................... 126 CHAPTER SIX – LABORATORY TESTING PROCEDURES 6.1 INTRODUCTION .............................................................................................. 132 6.2 STAGE 1: AGGREGATE TESTING AND PREPARATION .......................... 132 6.3 STAGE 2: TESTING FOR THE POTENTIAL ALKALI-SILICA REACTIVITY OF AGGREGATES ............................................... 135 6.3.1 Aggregate Testing Using ASTM C 227 .................................................... 135 6.3.2 Aggregate Testing Using ASTM C 1260 .................................................. 135 6.3.3 Aggregate Testing Using ASTM C 1293 .................................................. 142 6.4 STAGE 3: ASR MITIGATION ALTERNATIVES ........................................... 147 6.5 SUMMARY OF THE TESTING PROGRAM ................................................... 149 CHAPTER SEVEN – MIXTURE PROPORTIONS 7.1 ASTM C 227 MIXTURE PROPORTIONS ....................................................... 150 7.2 ASTM C 1260 MIXTURE PROPORTIONS ................................................... 151 7.3 ASTM C 1293 MIXTURE PROPORTIONS ................................................... 160 CHAPTER EIGHT – MISCELLANEOUS TESTING RESULTS 8.1 INTRODUCTION .............................................................................................. 169 8.2 PHYSICAL PROPERTY TESTS RESULTS ................................................... 169 8.3 PETROGRAPHIC EXAMINATION, CHEMICAL ANALYSIS AND FIELD PERFORMANCE DOCUMENTATION ............................................ 169 8.4 ASTM C 227 RESULTS OF TESTING .......................................................... 173 CHAPTER NINE – ASTM C 1260 RESULTS AND DISCUSSION 9.1 ASTM C 1260 ..................................................................................................... 178 9.2 ASTM C 1260 PERFORMED NY THE NAA ................................................... 183 9.3 MODIFIED C 1260: EXPANSION UP TO 56 DAYS ...................................... 185 9.4 MODIFIED C 1260: ADJUSTING WATER CONTENT TO ACCOUNT FOR AGGREGATES ABSORPTION ............................................................... 189 9.5 MODIFIED C 1260: USING A POLYNOMIAL FITTING PROCEDURE FOR INTERPRETATION OF RESULTS ......................................................... 193 9.6 MODIFIED C 1260: USING KOLMOGOROV-AVRAMI-MEHL- JOHNSTON’S MODEL FOR INTERPRETATION OF RESULTS ................. 194
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9.6.1 K-A-M-J’s Model Applied To NAA Data ................................................ 196 9.6.2 K-A-M-J’s Model Applied To Virginia’s Data ......................................... 297 9.7 MODIFIED C 1260: CHANGING THE MOLARITY OF THE TESTING SOLUTION ........................................................................................................ 298 CHAPTER TEN – ASTM C 1293 RESULTS AND DISCUSSION 10.1 ASTM C 1293 ................................................................................................... 210 10.2 MODIFIED C 1293: PRISMS STORED IN A 1N NaOH SOLUTION AT 800C ........................................................................................................... 217 10.3 MODIFIED C 1293: PRISMS STORED IN A 1N NaOH SOLUTION AT 380C ........................................................................................................... 227 10.4 MODIFIED C 1293: PRISMS STORED OVER WATER, AT 100% R.H. AND 600C ................................................................................................... 235 10.5 SUMMARY: STANDARD AND MODIFIED C 1293 TESTING PROCEDURES ........................................................................................... 241 CHAPTER ELEVEN – INVESTIGATION OF MITIGATION ALTERNATIVES USING ASTM C 1260 11.1 INTRODUCTION ............................................................................................ 243 11.2 EFFECT OF CLASS C FLY ASH USING C 1260 .......................................... 243 11.3 EFFECT OF CLASS F FLY ASH USING C 1260 ............................................ 249 11.4 EFFECT OF SILICA FUME USING C 1260 .................................................. 255 11.5 EFFECT OF GRANULATED SLAG USING C 1260 ...................................... 260 11.6 EFFECT OF CALCINED CLAY USING C 1260 ........................................... 266 11.7 EFFECT OF AIR ENTRAINMNT USING C 1260........................................... 274 11.8 EFFECT OF WATER-CEMENT RATIO USING C 1260 .............................. 279 11.9 EFFECT OF LITHIUM NITRATE (LiNO3) USING C 1260 ............................ 285 11.10 SUMMARY OF MITIGATION ALTERNATIVES INVESTIGATION USING C 1260 .............................................................................................. 292 11.11 EFFECTIVENESS OF THE MITIGATION ALTERNATIVES AT DIFFERENT CEMENT ALKALI CONTENT ............................................. 294 11.11.1 Effect of Class C Fly Ash Coupled with Various Cement Alkali Contents ................................................................................................ 305 11.11.2 Effect of Class F Fly Ash Coupled with Various Cement Alkali Contents ................................................................................................ 306 11.11.3 Effect of Granulated Slag Coupled with Various Cement Alkali Contents ................................................................................................ 307 11.11.4 Effect of Silica Fume Coupled with Various Cement Alkali Contents ................................................................................................ 308 11.11.5 Effect of Air Entrainment Coupled with Various Cement Alkali Contents ................................................................................................ 309 11.11.6 Effect of Calcined Clay Coupled with Various Cement Alkali Contents ................................................................................................ 309 11.12 EVALUATION OF THE MITIGATION ALTERNATIVES C 1260 RESULTS USING K-A-M-J’S MODEL ....................................................... 310 11.13 EVALUATION OF THE MITIGATION ALTERNATIVES C 1260
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RESULTS USING K-A-M-J’S MODEL ....................................................... 319 11.14 ASTM C 1260 INVESTIGATION OF MITIGATION ALTERNATIVES: SUMMARY ................................................................... 325 11.15 COMPARISON OF THE MITIGATION ALTERNATIVES ........................ 327 CHAPTER TWELVE – INVESTIGATION OF MITIGATION ALTERNATIVES USING ASTM C 1293 12.1 INTRODUCTION ............................................................................................ 331 12.2 INVESTIGATION OF MITIGATION ALTERNATIVES USING C 1293 ................................................................................................ 334 12.2.1 Effect of Class C Fly Ash Using C 1293 ................................................. 334 12.2.2 Effect of Class F Fly Ash Using C 1293 ................................................... 338 12.2.3 Effect of Silica Fume Using C 1293 ....................................................... 342 12.2.4 Effect of Granulated Slag Using C 1293................................................... 346 12.2.5 Effect of Calcined Clay Using C 1293 .................................................... 350 12.2.6 Effect of Lithium Nitrate (Lino3) Using C 1293 ....................................... 355 12.2.7 Effect of Air Entrainmnt Using C 1293 .................................................... 360 12.3 COMPARISON BETWEEN ONE YEAR C 1293 RESULTS AND 13-WEEK ACCELERATED C 1293 RESULTS ............................................ 367 12.4 INVESTIGATION OF MITIGATION ALTERNATIVES USING ACCELERATED C 1293 ................................................................. 368 12.4.1 Effect Class C Fly Ash Accelerated C 1293 ........................................... 369 12.4.2 Effect Class F Fly Ash Accelerated C 1293.............................................. 373 12.4.3 Effect Silica Fume Accelerated C 1293 .................................................. 378 12.4.4 Effect Granulated Slag Accelerated C 1293.............................................. 383 12.4.5 Effect Calcined Clay Accelerated C 1293 ............................................... 388 12.4.6 Effect Lithium Nitrate Accelerated C 1293............................................... 393 12.4.7 Effect Air Entrainmnt Accelerated C 1293 ............................................... 398 12.4.8 Effect of Lowering the Cement Alkali Content Using Accelerated C 1293 ............................................................................... 403 12.4.9 Comparison Betwwn the Effectiveness of the Different Mitigation Alternatives ............................................................................ 408 12.4.10 Summary of the Evaluation of the Mitigation Alternatives Using the Accelerated Concrete-Prism Test ........................................ 411 12.5 INVESTIGATION OF MITIGATION ALTERNATIVES USING ACCELERATED c 1293 RESULTS AND CEMENTS WITH DIFFERENT Na2Oequiv. CONTENTS ...................................................................................... 413 12.6 SUMMARY AND SPECIFICATION ............................................................. 418 CHAPTER THIRTEEN – COMPARISON BETWEEN C 1260, C 1293, PETROGRAPHIC ANALYSIS, AND FIELD INVESTIGATION RESULTS 13.1 INTRODUCTION ............................................................................................ 420 13.2 ASTM C 1260, ASTM C 1293, PETROGRAPHIC EXAMINATION AND FIELD PERFORMANCE ....................................................................... 420 13.3 ASTM C 1260 MITIGATION ALTERNATIVES VS. C 1293 MITIGATION ALTERNATIVES ................................................................... 427
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13.4 EVALUATING THE EFFECT OF CEMENT TOTAL ALKALI CONTENT USING ASTM C 1260 AND ACCELERATED C 1293 ............. 435 13.5 EVALUATING THE EFFECTIVENESS OF MITIGATION ALTERNATIVES WITH A 0.80% Na2Oequiv. CEMENT USING ASTM C 1260 AND ACCELERATED C 1293 ................................................ 437
CHAPTER FOURTEEN – GUIDELINES AND RECOMMENDATIONS 14.1 INTRODUCTION ............................................................................................ 438 14.2 PREDICTING THE POTENTIAL ALKALI-SILICA REACTIVITY OF AGGREGATES ......................................................................................... 439 14.2.1 Field Performance Record ....................................................................... 439 14.2.2 Laboratory Testing .................................................................................. 442 14.3 MINIMIZING POTENTIAL FOR ASR-RELATED DAMAGE ..................... 445 14.4 COST OF USING THE DIFFERENT MITIGATION ALTERNATIVES............................................................................................... 448 14.5 CONCLUDING REMARKS ............................................................................ 449 CHAPTER FIFTEEN – SUMMARY OF CONCLUSIONS 15.1 INTRODUCTION ............................................................................................ 452 15.2 ASSESSING AGGREGATE REACTIVITY ................................................... 452 15.3 EFFECTIVE MITIGATION ALTERNATIVES .............................................. 456 15.4 FINAL REMARKS .......................................................................................... 463 APPENDIX A – EFFECT OF CHANGING THE CURING SOLUTION MOLARITY ON THE RESULTS OF ASTM C 1260 ...................... 464 APPENDIX B – VARIABLES FOR THE K-A-M-J MODEL USING C 1260 EXPANSIONS UP TO 28 DAYS......................................................... 473 APPENDIX C - EFFECTIVE LEVELS OF CEMENT REPLACEMENT
WITH CLASS C FLY ASH, CLASS F FLY ASH, AND SILICA FUME EVALUATED USING THE K-M-A-J’S MODEL FOR A6-NM, A4-ID, A2-WY, C2-SD, AND B4-VA .……………...480
APPENDIX D – PETROGRAPHIC ANALYSIS AND FIELD PERFORMANCE DOCUMENTATION OF AGGREGATES ...................................... 484 REFERENCES ........................................................................................................... 501
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LIST OF TABLES Table Page 3.1 Testing Methods for Potential Aggregate Reactivity ....................................................25 3.2 Most Widely Used Aggregate Tests for Identifying ASR Reactivity...........................26 3.3 Alkali Contribution from Fly Ash: Concrete with Cristobalite.....................................38 3.4 Chemical Compositions of Three Investigated Ashes..................................................39 3.5 Tallowa Dam Cement and Fly Ash Properties ..............................................................42 3.6 Composition of Class C Fly Ashes (Kakodkar et al., 1997)..........................................45 3.7 Composition of Selective Natural Pozzolans Tested By Johnston et al ........................48 3.8 Properties of Investigated Fly Ashes (Chen et al. 1993) ...............................................51 3.9 Properties of Investigated Silica Fume, Natural Pozzolan, and Slag ............................51 3.10 Effective Levels of Replacements for Materials Effective in Mitigating the ASR Damage……………….. .............................................................................................52 3.11 Example for Specifying Fly Ash with Reactive Aggregates.......................................56 3.12 Slag Specification Example.........................................................................................57 4.1 Survey Results (published by RILEM in 1996) ..........................................................61 4.2 Classification of Aggregates by Different Test Methods (Shayan, 1992)...................66 4.3 Maximum Alkali Content (Tang et al., 1996) .............................................................82 4.4 Properties of Aggregates Investigated (Fournier, Bilodeau, and Malhotra; 1994)......75 4.5 Proposed Limits for Different Testing Conditions (Fournier et al., 1994)..................76 4.6 Recommended Procedures and Limits to Detect Alkali-Reactive Aggregates (Berube, 1992) ..........................................................................................79 4.7 Alkali Content Groups (Chatterji et al. 1992) ...............................................................82 4.8 Sand Classification (Chatterji et al. 1992).....................................................................83 4.9 Coarse Aggregate Classification (Chatterji et al. 1992) ................................................83 4.10 Specifications for Concrete (Chatterji et al. 1992) ......................................................84 4.11 Summary of the Different AFNOR Testing Procedures (Le Roux et al., 1996) .........88 4.12 Level of Prevention as Determined by the Category and Exposure of the Structure (Le Roux et al., 1996) ..................................................................................................89 4.13 Methodology Used for Level B Prevention (Le Roux et al., 1996) ............................90 4.14 Aggregate Sources Investigated Throughout the Study (Starks, 1993) ....................108 4.15 Results of the C 1260 Test (Starks, 1993).................................................................110 4.16 Investigated Aggregate Source, Field Performance, & C 227 Results (Lane, 1994) 113 4.17 Recommended Testing Procedures and Limits (Mid-Atlantic RTC, 1993) ..............116 4.18 Recommended Mitigation Alternatives and Methods of Validation (RTC 1993) ...116 4.19 Recommended Testing Procedures and Limits (Lead State Team, 1999).................117 4.20 Recommended Mitigation Alternatives and Methods of Validation (Lead State Team, 1999) .............................................................................................................118 4.21 C 1260 and C 1293 Results of Testing Performed by NAA (NAA, 1999) ...............121 5.1 Aggregates Representing the Complete Spectrum of ASR Reactivity......................123 5.2 Aggregates and Aggregate Sources Selected for the Study ......................................125 5.3 Chemical and Physical Properties of Type I/II Cement with High Alkali Content...127 5.4 Chemical and Physical Properties of Type I/II Cement with Low Alkali Content ...128 5.5 Chemical Properties of Granualted Slag ...................................................................128 5.6 Chemical and Physical Properties of Calcined Clay .................................................129 5.7 Chemical and Physical Properties of the Class C Fly Ash ........................................130
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5.8 Chemical and Physical Properties of the Class F Fly Ash ........................................130 5.9 Properties of Chemical Admixtures ..........................................................................131 6.1 Aggregate Testing Performed....................................................................................132 6.2 ASTM C 227 and C1260 Aggregate Grading Requirements ....................................133 6.3 ASTM C 1293 Coarse Aggregate Grading Requirements ........................................133 6.4 Aggregates and Test Combinations Used to Investigate Mitigation Alternatives.....148 6.5 Summary of the Testing Program..............................................................................149 7.1 Proportions and Mortar Properties for C 227 Mixtures.............................................150 7.2 Mortar Mixtures Used for ASTM C 1260, C 1260M1, C 1260M2, C 1260 M3, AND C 1260M4........................................................................................................151 7.3 Mortar Mixtures Used to Evaluate the Effect of Class C Fly Ash ............................152 7.4 Mortar Mixtures Used to Evaluate the Effect of Class F Fly Ash.............................153 7.5 Mortar Mixtures Used to Evaluate the Effect of Silica Fume ...................................153 7.6 Mortar Mixtures Used to Evaluate the Effect of Granulated Slag ............................154 7.7 Mortar Mixtures Used to Evaluate the Effect of Lithium Nitrate .............................155 7.8 Mortar Mixtures Used to Evaluate the Effect of Entrained Air ................................156 7.9 Mortar Mixtures Used to Evaluate the Effect Calcined Clay ....................................157 7.10 Mortar Mixtures Used to Evaluate the Effect of W/C...............................................158 7.11 Mortar Mixtures Used to Count for the Absorption of Aggregates ..........................159 7.12 Concrete Mix Proportions for ASTM C 1293 and Modified C 1293........................161 7.13 Concrete Mixtures Used to Investigate the Effect of Air Entrainment .....................162 7.14 Concrete Mixtures Used to Investigate the Effect of Silica Fume ............................163 7.15 Concrete Mixtures Used to Investigate the Effect of Class C Fly Ash .....................164 7.16 Concrete Mixtures Used to Investigate the Effect of Class F Fly Ash......................165 7.17 Concrete Mixtures Used to Investigate the Effect of Granulated Slag......................166 7.18 Concrete Mixtures Used to Investigate the Effect of Calcined Clay.........................167 7.19 Concrete Mixtures Used to Investigate the Effect of Lithium Nitrate.......................168 8.1 Physical Properties of Aggregates Investigated ........................................................170 8.2 Chemical Analysis of Aggregates .............................................................................171 8.3 Summary of Available Documentation on Aggregates Investigated ........................172 8.4 ASTM C 227 Expansion Results for Aggregates investigated..................................173 9.1 ASTM C 1260 Expansion Test Results.....................................................................179 9.2 ASTM C 1260 Performed by NAA...........................................................................183 9.3 Differences Between NAA Results and Results Generated in this Study .................183 9.4 Variations from the Mean of the NAA and the C 1260 Results Generated Through this Study ..................................................................................184 9.5 Expansions up to 56 days in 1N NaOH Curing Solution ..........................................185 9.6a C 1260 Expansions for Mixtures Adjusted for Aggregate Absorption .....................190 9.6b Expansions of Category A Aggregates (Different Molarity Solutions) ....................199 9.7 Expansions of Category B, C, & D Agg. (Different Molarity Solutions) .................200 9.8 Expansions of Category E Aggregates (Different Molarity Solutions).....................201 9.9 14-Day Expansions of the Different Testing Solutions.............................................202 9.10 Effect of Na2Oequiv. Content on ASR Using ASTM C 1260 ......................................208 10.1 ASTM C 1293 Results for Category A Aggregates ..................................................211 10.2 ASTM C 1293 Results for Category B, C, & D Aggregates ............................................211 10.3 Standard ASTM C 1293 Results for Category E Aggregates ..................................212
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10.4 Expansions of Concrete Prisms Stored in 1N NaOH Solution at 80oC for Category A Aggregates ................................................................................................................217 10.5 Expansions of Concrete Prisms Stored in 1N NaOH Solution at 80oC for Category B, C, & D Aggregates ...............................................................................................218 10.6 Expansions of Concrete Prisms Stored in 1N NaOH Solution at 80oC for Category E Aggregates ................................................................................................................218 10.7 Summary of Generated Results: ASTM C 1293 vs 1N NaOH at 800C Using Respectively 0.040% at One-year and 0.040% at Four-Week as Failure Criteria ...223 10.8 Summary of Generated Results: ASTM C 1293 vs 1N NaOH at 800C Using Respectively 0.040% at One-year and 0.060% at 1-week as Failure Criteria .........225 10.9 Expansions of Concrete Prisms Stored in 1N NaOH Solution at 38oC for Category A Aggregates ................................................................................................................227 10.10 Expansions of Concrete Prisms Stored in 1N NaOH Solution at 38oC for Category B, C, & D Aggregates ...............................................................................................228 10.11 Expansions of Concrete Prisms Stored in 1N NaOH Solution at 38oC for Category E Aggregates ................................................................................................................228 10.12 Summary of Generated Results: ASTM C 1293 vs 1N NaOH at 800C Using Respectively 0.040% at One-year and 0.040% at 26-week as Failure Criteria .......233 10.13 Expansions of Category A Aggregate Concrete Prisms Stored Over Water, at 100% R.H., and 600C ......................................................................235 10.14 Expansions of Category B, C, & D Aggregate Concrete Prisms Stored Over Water, at 100% R.H., and 600C...........................................................................................235 10.15 Expansions of Category E Aggregate Concrete Prisms Stored Over Water, at 100% R.H., and 600C...........................................................................................236 10.16 Summary of Generated Results: ASTM C 1293 vs C 1293 at 600C Using Respectively 0.040% at One-year and 0.040% at 13-week as Failure Criteria .......239 10.17 Expansion Limits for the Different C 1293 Procedures ...........................................241 10.18 Aggregate’s Reactivity Classification for the Different C 1293 Procedures............241 10.19 Summary Results of the Different C 1293 Procedures.............................................242 11.1 C 1260 Expansions Using Class C Fly Ash .............................................................244 11.2 Effect of Class C Fly Ash on the 14-Day C 1260 Expansions.................................249 11.3 C 1260 Expansions Using Class F Fly Ash..............................................................250 11.4 Effect of Class F Fly Ash on the 14-Day C 1260 Expansions .................................254 11.5 C 1260 Expansions Using Silica Fume ....................................................................255 11.6 Effect of Silica Fume on the 14-Day C 1260 Expansions........................................260 11.7 C 1260 Expansions Using Granulated Slag..............................................................261 11.8 Effect of Granulated Slag on the 14-Day C 1260 Expansions .................................266 11.9 C 1260 Expansions Using Calcined Clay.................................................................267 11.10 Category E C 1260 Expansions Using Calcined Clay..............................................272 11.11 Effect of Calcined Clay on the 14-Day C 1260 Expansions ....................................273 11.12 C 1260 Expansions Using Air Entrainment .............................................................274 11.13 Effect of Air Entrainment on the 14-Day C 1260 Expansions .................................279 11.14 C 1260 Expansions Using Various Water-Cement Ratios .......................................280 11.15 C 1260 Expansions Using Different LiNO3 Dosages...............................................286 11.16 Effect of LiNO3 on the 14-Day C 1260 Expansions ................................................291 11.17 Effectiveness of the Mitigation Alternatives Using the
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14-day of 0.10% Criteria ..........................................................................................293 11.18 Expansion Results of A6-NM Used with Mitigation Alternatives at Different Cement Alkali Content.............................................................................295 11.19 Exposure Solution Normalities Investigated and their Corresponding Na2Oequiv. Content and Recommended Expansion Limits .........................................................305 11.20 Effectiveness of Class C Fly Ash at Different Cement Alkali Contents with the Highly Reactive Aggregate A6-NM (0.92% C1260, 14-Day)............................306 11.21 Effectiveness of Class F Fly Ash at Different Cement Alkali Contents with the Highly Reactive Aggregate A6-NM (0.92% C1260, 14-Day)............................307 11.22 Effectiveness of Granulated Slag at Different Cement Alkali Contents with the Highly Reactive Aggregate A6-NM (0.92% C1260, 14-Day)............................308 11.23 Effectiveness of Silica Fume at Different Cement Alkali Contents with the Highly Reactive Aggregate A6-NM (0.92% C1260, 14-Day)............................308 11.24 Effectiveness of Air Entrainment at Different Cement Alkali Contents with the Highly Reactive Aggregate A6-NM (0.92% C1260, 14-Day)............................309 11.25 Effectiveness of Calcined Clay at Different Cement Alkali Contents with the Highly Reactive Aggregate A6-NM (0.92% C1260, 14-Day)............................310 11.26 Mitigation Alternatives Results Using K-A-M-J’s Ln (k) = -6 ................................318 11.27 Predicted Levels of Replacement Using the K-M-A-J’s Model...............................319 11.28 C 1260 Expansions of Some Predicted Values of K-M-A-J’s Model .....................320 11.29 Effective ASR Mitigation Alternatives When Evaluating Aggregates Using ASTM C 1260 with 1N NaOH Solution (1.5% Na2Oequiv.).......................................327 11.30 Effective ASR Mitigation Alternatives for Highly Reactive Aggregate A6-NM (C1260 14-day of 0.92%) Evaluated Using C 1260 with 0.75N, 0.50N, & 0.35N NaOH Solutions .................................................................326 12.1 Aggregates Used for Mitigation Alternative Investigation ......................................333 12.2 C 1293 Expansions Using Class C Fly Ash .............................................................335 12.3 Effect of Class C Fly Ash on ASR Using C 1293....................................................338 12.3a C 1293 Expansions Using Class F Fly Ash ..............................................................341 12.4 Effect of Class F Fly Ash on ASR Using C 1293 ....................................................342 12.5 C 1293 Expansions Using Silica Fume ....................................................................343 12.6 Effect of Silica Fume on ASR Using C 1293...........................................................346 12.7 C 1293 Expansions Using Granulated Slag..............................................................347 12.8 Effect of Granulated Slag on ASR Using C 1293 ....................................................350 12.9 C 1293 Expansions Using Granulated Slag..............................................................351 12.10 Effect of Calcined Clay on ASR Using C 1293 .......................................................354 12.11 C 1293 Expansions Using Lithium Nitrate ..............................................................356 12.12 Effect of Lithium Nitrate on ASR Using C 1293 .....................................................359 12.13 C 1293 Expansions Using Air Entrainment .............................................................363 12.14 Effect of Air Entrainment on ASR Using C 1293....................................................364 12.15 Additional C 1293 Expansions Using Air Entrainment ...........................................365 12.16 Accelerated C 1293 Expansions Using Class C Fly Ash .........................................372 12.17 Effect of Class C Fly Ash on ASR Using Accelerated C 1293................................373 12.18 Accelerated C 1293 Expansions Using Class F Fly Ash..........................................374 12.19 Effect of Class F Fly Ash on ASR Using Accelerated C 1293 ................................378 12.20 Accelerated C 1293 Expansions Using Silica Fume ................................................379
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12.21 Effect of Silica Fume on ASR Using Accelerated C 1293.......................................383 12.22 Accelerated C 1293 Expansions Using Granulated Slag..........................................384 12.23 Effect of Granulated Slag on ASR Using Accelerated C 1293 ................................388 12.24 Accelerated C 1293 Expansions Using Granulated Slag..........................................389 12.25 Effect of Calcined Clay on ASR Using Accelerated C 1293 ...................................393 12.26 Accelerated C 1293 Expansions Using Lithium Nitrate ..........................................394 12.27 Effect of Lithium Nitrate on ASR Using Accelerated C 1293 .................................398 12.28 Accelerated C 1293 Expansions Using Air Entrainment .........................................399 12.29 Effect of Air Entrainment on ASR Using Accelerated C 1293 ................................403 12.30 Accelerated C 1293 Expansions Using Different Cement Na2Oequiv. Contents ........404 12.31 Effect of Na2Oequiv. Content on ASR Using Accelerated C 1293 .............................408 12.32 Effectiveness of the Mitigation Alternatives Using the Accelerated C 1293 Criteria..412 12.33 Accelerated C 1293 Expansions of Aggregate A6-NM Using Different Mitigation Alternatives and 0.80% Na2Oequiv. Content Cement................................414 12.34 Effectiveness of Different Mitigation Alternatives Using the Accelerated C 1293 with Aggregate A6-NM and 0.80% Na2Oequiv. Cement ............417 12.35 Effective ASR Mitigation Alternatives When Evaluating Aggregates Using Accelerated C 1293 at 600C ........................................................418 12.36 Effective ASR Mitigation Alternatives for Highly Reactive Aggregate A6-NM (Accelerated C 1293 13-week of 0.407%) Evaluated Using Accelerated C 1293 (600C) with 0.80% Na2Oequiv. Cement ......................................419 13.1 C 1260 14-Day Expansions and C 1293 52-Week Expansions ...............................421 13.2 Expansion Limits Used to Evaluate Effectiveness of Mitigation Alternatives ........427 13.3 Effectiveness of Mitigation Alternatives with Aggregate A4-ID Evaluated Using C 1260 and Accelerated C 1293....................................................428 13.4 Effectiveness of Mitigation Alternatives with Aggregate A2-WY Evaluated Using C 1260 and Accelerated C 1293....................................................429 13.5 Effectiveness of Mitigation Alternatives with Aggregate C2-SD Evaluated Using C 1260 and Accelerated C 1293....................................................430 13.6a Effect of Na2Oequiv. Content on ASR Using ASTM C 1260 .....................................436 13.6b Effect of Na2Oequiv. Content on ASR Using Accelerated C 1293 .............................436 13.7 Effective ASR Mitigation Alternatives for Highly Reactive Aggregate A6-NM (C1260 14-day of 0.92%) Evaluated Using a Cement Alkali Content of 0.80% Na2Oequiv. ..438 14.1 Expansion Limits for Identifying Potentially Alkali-Silica Reactive Aggregates....444 14.2 Determination of the Degree of Alkali-Silica Reactivity of Aggregates..................444 14.3 Cost of Materials Used Throughout Investigation ...................................................448 14.4 Cost of Using the Mitigation Alternatives for a Cementitious Material Content of 710 lb/yd3................................................................................................449 15.1 Effectiveness of the Mitigation Alternatives Using the 14-Day C 1260 Test with 0.10% Criteria .................................................................456 15.2 Effective ASR Mitigation Alternatives for Highly Reactive Aggregate A6-NM (C1260 14-Day Expansion of 0.92%) Evaluated with 0.75N, 0.50N, & 0.35N NaOH Solutions .........................................................457 15.3 Effectiveness of the Mitigation Alternatives Using the Accelerated C 1293 Criteria......................................................................................459 15.4 Effective ASR Mitigation Alternatives ....................................................................461
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15.5 Effective ASR Mitigation Alternatives for Highly Reactive Aggregate A6-NM (ASTM C 1293 One-year Expansion of 0.411%) Using 0.80% Na2Oequiv. Cement .462
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LIST OF FIGURES Figure Page 1.1 Results of the DOT Survey ...........................................................................................2 2.1 Silicon Tetrahedron (Silica) ........................................................................................12 2.2 Quartz Structure (SiO2) (Crystalline Structure) ............................................................12 2.3 Effect of Silica Content On ASR...................................................................................14 3.1 Effect of alkali content (% Na2Oeq) in the ASTM C 227 Mortar-Bar Method (Siliceous limestone from Ottawa, Ontario).................................................................19 3.2 Effect of water-cement ratio in the ASTM C 227 Mortar-Bar Method (Siliceous Limestone from Trois-Rivieres, Quebec) ....................................................................20 3.3 Comparison Between ASTM C 1260 and ASTM C 1293 Results Illustrating the Severity of ASTM C 1260 .....................................................................................21 3.4 Effect of Aggregate Reactivity and Percent Fly Ash Replacement on the Effective Alkali Contribution from Fly Ash ................................................................33 3.5 Effect of Aggregate Reactivity Effective Alkali Contribution from Fly Ash ...............34 3.6 Using 25% Class F Fly Ash to Prevent Cracking of Concrete Made with a Moderately Reactive Aggregate (flint).........................................................................35 3.7 Effect of Using 6% Class F Fly Ash with a Moderately Reactive Aggregate (flint) 35 3.8 Effect of Class F Fly Ash on Cracking of Concrete Made with a Highly Reactive Aggregate ......................................................................................................36 3.9 Effect of Class F Fly Ash on Expansions of Concrete Containing a Highly Reactive Aggregate (Cristobalite) ................................................................................38 3.10 Effect of Replacement Levels of Fly Ash A on ASR Expansions ..............................40 3.11 Effect of Replacement Levels of Fly Ash B on ASR Expansions...............................40 3.12 Effect of Replacement Levels of Fly Ash F on ASR Expansions...............................41 3.13 Expansion Curves for Concrete Cores Taken from Several Locations of the Dam and Stored in a 1M NaOH Solution at 400C..................................................43 3.14 ASTM C 1260 vs. Replacement Levels of Cement with Class F Fly Ash..................44 3.15 Comparison of 14-Dya Expansions of Mortar Bars Made with the Different Fly Ashes and a Slowly Reactive Aggregate................................................46 3.16 Comparison of 14-Dya Expansions of Mortar Bars Made with the Different Fly Ashes and a Highly Reactive Aggregate ................................................46 3.17 Effect of Class F Fly Ash on the 14-Day Expansions of Mortar Bars Made with a Highly Reactive Aggregates and Tested Using ASTM C 1260 ......................47 3.18 Effect of Selective Natural Pozzolans on the 14-Day Expansions of Mortar Bars Made with a Highly Reactive Aggregates and Tested Using C 1260................49 3.19 Expansions of Concrete Prisms Made Using a Cement with 1.13% alkalis, a Reactive Aggregate (Spratt), and 58% Class F Fly Ash: Prisms Stored in a 1M NaOH Solution at 380C.................................................................................50 3.20 C 227 Expansion after 6 Months for Specimens Made with Multiple Replacement Levels ...................................................................................................54 4.1 Decision Chart for Determining the Potential ASR of ConcreteAggregates .................81 4.2 Flowchart of Testing Procedures Used to Evaluate Aggregate Reactivity....................94 4.3 Failure Criteria for Determining Safe Cement Alkali Level for
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Deleterious Aggregates ..............................................................................................111 4.4 Flow Chart Suggested by PCA....................................................................................119 5.1 Locations of the Selected Aggregate Sources ...........................................................124 6.1 Aggregate Washing Over #100 Sieve .......................................................................134 6.2 Sieve Sizes Required For C 227 and C 1260 Mortar Bars ..........................................134
6.3 Mortar Bars Cured for 24 Hours in a Moisture Room, Immediately after Formation(C 227 and C 1260)……………… ....................................................................................136
6.4 Mortar Bars Stored over Sater, in Containers with No Sicks, in an Environmental Room at 380C …………………………...…………………………………………..136
6.5 First Step in Performing ASTM C 227........................................................................137 6.6 Second Step in Performing ASTM C 227 ...................................................................138 6.7 Mortar Bars Stored in a 1N NaOH Solution Used for C 1260 ....................................140 6.8 Mortar Bars Stored in an Oven at 800C, in 1N NaOH Solution (C 1260
Requirements) …………………………………………………………………140 6.9 ASTM C 1260 Procedures ..........................................................................................141 6.10 Concrete Prisms Stored Over Water, in 6-gal Buckets with Wicks, in an Environmental Room at 380C...................................................................................143 6.11 C 1293 Buckets Stored for 16 h in a Moisture Room before Measuring Scheduled Expansion Eeadings..............................................................144 6.12 Top View of a C 1293 Bucket; Concrete Prisms over Water; Wicks on the Sides; Seal Cover ...............................................................................144 6.13 Concrete Prism Being Measured for Expansion........................................................144 6.14 Aggregate Preparation for C 1293.............................................................................145 6.15 C 1293 Concrete Prism Procedures...........................................................................146 8.1 ASTM C 227 Results for Category A Aggregates .....................................................174 8.2 ASTM C 227 Results of Category B, C, & D Aggregates .........................................174 8.3 ASTM C 227 Results for Category E Aggregates......................................................175 9.1 ASTM C 1260 Expansions for Category A Aggregates ............................................180 9.2 ASTM C 1260 Expansions for Category B, C, & D Aggregates ...............................180 9.3 ASTM C 1260 Expansions for Category E Aggregates .............................................181 9.4 Comparison Between the 14-Day Expansions Generated for the ASTM C 1260 and for the 56-Day Extended ASTM C 1260.............................................................186 9.5 56-Day C 1260 Results for Category A Aggregates ..................................................187 9.6 56-Day C 1260 Results for Category B, C, & D Aggregates.....................................187 9.7 56-Day C 1260 Results for Category E Aggregates...................................................188 9.8 Modified Water C 1260 Expansions for Category A Aggregates ..............................191 9.9 Modified Water C 1260 Expansions for Category B, C, & D Aggregates.................191 9.10 Modified Water C 1260 Expansions for Category E Aggregates ............................192 9.11 Polynomial Regression Coefficients A1 vs. A2 ........................................................193 9.12a Avrami’s Exponent M versus ln(k) Illustrating Avrami’s Equation ......................195 9.12b K-A-M-J’s Model Results For NAA C 1260 Data.................................................196 9.12c K-A-M-J’s Model Results For Virginia Aggregates ..............................................197 9.13 14-Day Expansion Comparison Between Different Curing Solutions, Category A Aggregates .....................................................................................................203 9.14 14-Day Expansion Comparison Between Different Curing Solutions Category B, C, & D Aggregates..............................................................................203
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9.15 14-Day Expansion Comparison Between Different Curing Solutions Category E Aggregates ………………………………………………………………..204
9.16 Category A Results at Different Solution Normalities and Cement Alkali Content ...........................................................................................205 9.17 Category B, C, & D Results at Different Solution Normalities and Cement Alkali Content .................................................................205 9.18 Category E Results at Different Solution Normalities and Cement Alkali Content .....................................................................................206 10.1a ASTM C 1293 Results for Category A Aggregates ...............................................212 10.1b ASTM C 1293 Results for Coarse Aggregates of Category A...............................213 10.1c ASTM C 1293 Results for Fine Aggregates of Category A...................................213 10.2 ASTM C 1293 Results for Category B, C, & D Aggregates....................................214 10.3 ASTM C 1293 Results for Category E Aggregates..................................................214 10.4 Comparison Between the 12-month Expansions of Tested Coarse and Fine Aggregates from the Same Source ...........................................................................215 10.5a 52-Week (One-year) Expansions of Concrete Prisms Stored in 1N NaOH Solution at 80oC for Category A Aggregates .........................................................219 10.5b Four-Week Expansions of Concrete Prisms Stored in 1N NaOH Solution at 80oC for Category A Aggregates ...........................................................................219 10.6a 52-Week (One-year) Expansions of Concrete Prisms Stored in 1N NaOH Solution at 80oC for Category B, C, and D Aggregates ........................................220 10.6b Four-Week Expansions of Concrete Prisms Stored in 1N NaOH Solution at 80oC for Category B, C, and D Aggregates...........................................................220 10.7a 52-Week (One-year) Expansions of Concrete Prisms Stored in 1N NaOH Solution at 80oC for Category E Aggregates.........................................................221 10.7b Four-Week Expansions of Concrete Prisms Stored in 1N NaOH Solution at 80oC for Category E Aggregates ...........................................................................221 10.8 Comparison Between the Standard C 1293 procedures and Modified C 1293 Storing Prisms in 1N NaOH at 800C .......................................................................226 10.9a 52-Week (One-year) Expansions of Concrete Prisms Stored in 1N NaOH Solution at 38oC for Category A Aggregates ........................................................229 10.9b 13-Week (6-Month) Expansions of Concrete Prisms Stored in 1N NaOH Solution at 38oC for Category A Aggregates ........................................................229 10.10a 52-Week (One-year) Expansions of Concrete Prisms Stored in 1N NaOH Solution at 38oC for Category B, C, & D Aggregates.........................................230 10.10b 13-Week (6-month) Expansions of Concrete Prisms Stored in 1N NaOH Solution at 38oC for Category B, C, & D Aggregates...........................................230 10.11a 52-Week (One-year) Expansions of Concrete Prisms Stored in 1N NaOH Solution at 38oC for Category E Aggregates.......................................................231 10.11b 13-Week (6-month) Expansions of Concrete Prisms Stored in 1N NaOH Solution at 38oC for Category E Aggregates.......................................................231 10.12 Comparison Between the Standard C 1293 procedures and Modified C 1293 Storing Prisms in 1N NaOH at 380C .....................................................................234 10.13 Expansions of Category A Aggregate Concrete Prisms Stored Over Water, at 100% R.H., and 600C....................................................................236 10.14 Expansions of Category B, C, & D Aggregate Concrete Prisms Stored Over
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Water, at 100% R.H., and 600C.............................................................................237 10.15 Expansions of Category E Aggregate Concrete Prisms Stored Over Water, at 100% R.H., and 600C ............................................................................................237 10.16 Comparison Between the Standard C 1293 procedures and Modified C 1293 at 600C ...................................................................................................240 11.1 Effect of Class C Fly Ash on C 1260 Expansions of Aggregate A2-WY ..............................................................................................245 11.2 Effect of Class C Fly Ash on C 1260 Expansions of Aggregate A4-ID .................................................................................................245 11.3 Effect of Class C Fly Ash on C 1260 Expansions of Aggregate A6-NM ...............................................................................................246 11.4 Effect of Class C Fly Ash on C 1260 Expansions of Aggregate B4-VA ................................................................................................246 11.5 Effect of Class C Fly Ash on C 1260 Expansions of Aggregate C2-SD ................................................................................................247 11.6 Effect of Class C Fly Ash on C 1260 Expansions of Aggregate E2-IA .................................................................................................247 11.7 Comparison of the 14-Day C 1260 Expansions for the Different Aggregates and Levels of Class C Fly Ash Replacement ........................................................248 11.8 Effect of Class F Fly Ash on C 1260 Expansions of Aggregate A2-WY ..............................................................................................250 11.9 Effect of Class F Fly Ash on C 1260 Expansions of Aggregate A4-ID .................................................................................................251 11.10 Effect of Class F Fly Ash on C 1260 Expansions of Aggregate A6-NM ...............................................................................................251 11.11 Effect of Class F Fly Ash on C 1260 Expansions of Aggregate B4-VA ................................................................................................252 11.12 Effect of Class F Fly Ash on C 1260 Expansions of Aggregate C2-SD ................................................................................................252 11.13 Effect of Class F Fly Ash on C 1260 Expansions of Aggregate E2-IA .................................................................................................253 11.14 Comparison of the 14-Day C 1260 Expansions for the Different Aggregates and Levels of Class F Fly Ash Replacement.........................................................253 11.15 Effect of Silica Fume on C 1260 Expansions of Aggregate A2-WY ...................256 11.16 Effect of Silica Fume on C 1260 Expansions of Aggregate A4-ID .....................256 11.17 Effect of Silica Fume on C 1260 Expansions of Aggregate A6-NM ...................257 11.18 Effect of Silica Fume on C 1260 Expansions of Aggregate B4-VA ....................257 11.19 Effect of Silica Fume on C 1260 Expansions of Aggregate C2-SD .....................258 11.20 Effect of Silica Fume on C 1260 Expansions of Aggregate E2-IA ......................258 11.21 Comparison of the 14-Day C 1260 Expansions for the Different Aggregates and Levels of Silica Fume Replacement ...............................................................259 11.22 Effect of Granulated Slag on C 1260 Expansions of Aggregate A2-WY ..............................................................................................262 11.23 Effect of Granulated Slag on C 1260 Expansions of Aggregate A4-ID .................................................................................................262 11.24 Effect of Granulated Slag on C 1260 Expansions of
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Aggregate A6-NM ...............................................................................................263 11.25 Effect of Granulated Slag on C 1260 Expansions of Aggregate B4-VA ................................................................................................263 11.26 Effect of Granulated Slag on C 1260 Expansions of Aggregate C2-SD ................................................................................................264 11.27 Effect of Granulated Slag on C 1260 Expansions of Aggregate E2-IA .................................................................................................264 11.28 Comparison of the 14-Day C 1260 Expansions for the Different Aggregates and Levels of Granulated Slag Replacement.........................................................265 11.29 Effect of Calcined Clay on C 1260 Expansions of Aggregate A2-WY ...............268 11.30 Effect of Calcined Clay on C 1260 Expansions of Aggregate A4-ID ..................268 11.31 Effect of Calcined Clay on C 1260 Expansions of Aggregate A6-NM ................269 11.32 Effect of Calcined Clay on C 1260 Expansions of Aggregate B4-VA ................269 11.33 Effect of Calcined Clay on C 1260 Expansions of Aggregate C2-SD .................270 11.34 Effect of Calcined Clay on C 1260 Expansions of Aggregate E2-IA ..................270 11.35 Comparison of the 14-Day C 1260 Expansions for the Different Aggregates and Levels of Calcined Clay Replacement............................................................271 11.36 Effect of Calcined Clay on the 14-Day C 1260 Expansions of Category E Aggregates .....................................................................................272 11.37 Effect of Air Entrainment on C 1260 Expansions of Aggregate A2-WY ..............................................................................................275 11.38 Effect of Air Entrainment on C 1260 Expansions of Aggregate A4-ID .................................................................................................275 11.39 Effect of Air Entrainment on C 1260 Expansions of Aggregate A6-NM ...............................................................................................276 11.40 Effect of Air Entrainment on C 1260 Expansions of Aggregate B4-VA ................................................................................................276 11.41 Effect of Air Entrainment on C 1260 Expansions of Aggregate C2-SD ................................................................................................277 11.42 Effect of Air Entrainment on C 1260 Expansions of Aggregate E2-IA .................................................................................................277 11.43 Comparison of the 14-Day C 1260 Expansions for the Different Aggregates and Levels of Entrained Air Levels.......................................................................278 11.44 Effect of W/C on C 1260 Expansions of Aggregate A2-WY ...............................281 11.45 Effect of W/C on C 1260 Expansions of Aggregate A4-ID .................................281 11.46 Effect of W/C on C 1260 Expansions of Aggregate A6-NM ...............................282 11.47 Effect of W/C on C 1260 Expansions of Aggregate B4-VA ................................282 11.48 Effect of W/C on C 1260 Expansions of Aggregate C2-SD ................................283 11.49 Comparison of the 14-Day C 1260 Expansions for the Different Water-Cement Ratios ............................................................................................283 11.50 Effect of LiNO3 on C 1260 Expansions of Aggregate A2-WY ...........................287 11.51 Effect of LiNO3 on C 1260 Expansions of Aggregate A4-ID ..............................287 11.52 Effect of LiNO3 on C 1260 Expansions of Aggregate A6-NM ............................288 11.53 Effect of LiNO3 on C 1260 Expansions of Aggregate B4-VA .............................288 11.54 Effect of LiNO3 on C 1260 Expansions of Aggregate C2-SD .............................289 11.55 Effect of LiNO3 on C 1260 Expansions of Aggregate E2-IA ..............................289
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11.56 Comparison of the 14-Day C 1260 Expansions for the Different LiNO3 Dosages 290 11.57 Effect of Class C Fly Ash at Different Cement Alkali Contents for the Highly Reactive A6-NM ...................................................................................................296 11.58 Effect of Class F Fly Ash at Different Cement Alkali Contents for the Highly Reactive A6-NM ...................................................................................................297 11.59 Effect of granulated Slag at Different Cement Alkali Contents for the Highly Reactive A6-NM ...................................................................................................297 11.60 Effect of Silica Fume at Different Cement Alkali Contents for the Highly Reactive A6-NM ...................................................................................................298 11.61 Effect of Air Entrainment at Different Cement Alkali Contents for the Highly Reactive A6-NM ...................................................................................................298 11.62 Effect of Calcined Clay at Different Cement Alkali Contents for the Highly Reactive A6-NM ...................................................................................................299 11.63a Comparison of the 14-Day Expansions for the Combination of 35% Class C Fly Ash with Different Cement Alkali Contents ...................................................300 11.63b Comparison of the 14-Day Expansions for the Combination of 25% Class C Fly Ash with Different Cement Alkali Contents ...................................................300 11.64a Comparison of the 14-Day Expansions for the Combination of 20% Class F Fly Ash with Different Cement Alkali Contents ...................................................301 11.64b Comparison of the 14-Day Expansions for the Combination of 15% Class F Fly Ash with Different Cement Alkali Contents ...................................................301 11.65a Comparison of the 14-Day Expansions for the Combination of 50% Granulated Slag with Different Cement Alkali Contents......................................302 11.65b Comparison of the 14-Day Expansions for the Combination of 25% Granulated Slag with Different Cement Alkali Contents......................................302 11.66a Comparison of the 14-Day Expansions for the Combination of 10% Silica Fume with Different Cement Alkali Contents.............................................303 11.66b Comparison of the 14-Day Expansions for the Combination of 5% Silica Fume with Different Cement Alkali Contents.............................................303 11.67 Comparison of the 14-Day Expansions for the Combination of Air Entrainment with Different Cement Alkali Contents......................................304 11.68 Comparison of the 14-Day Expansions for the Combination of Calcined Clay with Different Cement Alkali Contents .........................................304 11.69 Ln (K) Values for Various Class C and Class F fly ash Replacement Levels Using 14-Day C 1260 Results ...............................................................................311 11.70 Ln (K) Values for Various Silica Fume and Granulated Slag Replacement Levels Using 14-Day C 1260 Results..............................................312 11.71 Ln (K) Values for Various Calcined Clay and Lithium Nitrate Replacement Levels Using 14-Day C 1260 Results..............................................312 11.72 M Values for Various Air Entrainment Levels and Various Water-Cement Ratios Using 14-Day C 1260 Results ...........................................313 11.73 M Values for Various Class C and Class F Fly Ash Replacement Levels Using 14-Day C 1260 Results ...............................................................................313 11.74 M Values for Various Silica Fume and Granulated Slag Replacement Levels Using 14-Day C 1260 Results..............................................314
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11.75 M Values for Various Calcined Clay and Lithium Nitrate Replacement Levels Using 14-Day C 1260 Results..............................................314 11.76 M Values for Various Air Entrainment Levels and Various Water-Cement Ratios Using 14-Day C 1260 Results ...........................................315 11.77 Ln (K) vs. M Plot for the Class C and Class F Fly Ash C 1260 Results .................................................................................................... 315 11.78 Ln (K) vs. M Plot for the Silica Fume and Granulated Slag C 1260 Results .................................................................................................... 316 11.79 Ln (K) vs. M Plot for the Calcined Clay and LiNO3 C 1260 Results .................................................................................................... 316 11.80 Ln (K) vs. M Plot for the Air Entrainment and Various W/C C 1260 Results .................................................................................................... 317 11.81 Effectiveness of K-M-A-J Model Predictions for Aggregate A2-WY................... 321 11.82 Effectiveness of K-M-A-J Model Predictions for Aggregate A4-ID ..................... 321 11.83 Effectiveness of K-M-A-J Model Predictions for Aggregate A6-NM ................... 322 11.84 Effectiveness of K-M-A-J Model Predictions for Aggregate B4-VA.................... 322 11.85 Effectiveness of K-M-A-J Model Predictions for Aggregate C2-SD..................... 323 11.86 Comparison Between the 14-Day C 1260 expansions of Aggregates with 0% Replacement and with Predicted Replacements .................................................... 323 11.87 Mitigation Alternatives Used with Aggregate A6-NM .......................................... 328 11.88 Mitigation Alternatives Used with Aggregate A4-ID ............................................ 328 11.89 Mitigation Alternatives Used with Aggregate A2-WY.......................................... 329 11.90 Mitigation Alternatives Used with Aggregate C2-SD............................................ 329 11.91 Mitigation Alternatives Used with Aggregate B4-VA........................................... 330 11.92 Mitigation Alternatives Used with Aggregate E2-IA............................................. 330 12.1 Summary of the Investigation of Mitigation Alternatives Using C 1293 and Accelerated C 1293 .................................................................332 12.2 Effect of Class C Fly Ash on C 1293 Expansions of Aggregate A4-ID .................................................................................................336 12.3 Effect of Class C Fly Ash on C 1293 Expansions of Aggregate A2-WY ..............................................................................................336 12.4 Effect of Class C Fly Ash on C 1293 Expansions of Aggregate C2-SD ................................................................................................337 12.5 Comparison Between the 52-week (One-year) Expansions of the Different Aggregates and Levels of Class C Fly Ash Replacement .....................................337 12.6 Effect of Class F Fly Ash on C 1293 Expansions of Aggregate A4-ID .................................................................................................339 12.7 Effect of Class F Fly Ash on C 1293 Expansions of Aggregate A2-WY ..............................................................................................339 12.8 Effect of Class F Fly Ash on C 1293 Expansions of Aggregate C2-SD ................................................................................................340 12.9 Comparison Between the 52-week (One-year) Expansions of the Different Aggregates and Levels of Class F Fly Ash Replacement......................................340 12.10 Effect of Silica Fume on C 1293 Expansions of Aggregate A4-ID .....................344 12.11 Effect of Silica Fume on C 1293 Expansions of Aggregate A2-WY ...................344 12.12 Effect of Silica Fume on C 1293 Expansions of Aggregate C2-SD .....................345
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12.13 Comparison Between the 52-week (One-year) Expansions of the Different Aggregates and Levels of Silica Fume Replacement ............................................345 12.14 Effect of Slag on C 1293 Expansions of Aggregate A4-ID .................................348 12.15 Effect of Slag on C 1293 Expansions of Aggregate A2-WY ...............................348 12.16 Effect of Slag on C 1293 Expansions of Aggregate C2-SD .................................349 12.17 Comparison Between the 52-week (One-year) Expansions of the Different Aggregates and Levels of Slag Replacement ........................................................349 12.18 Effect of Calcined Clay on C 1293 Expansions of Aggregate A4-ID ..................352 12.19 Effect of Calcined Clay on C 1293 Expansions of Aggregate A2-WY ...............352 12.20 Effect of Calcined Clay on C 1293 Expansions of Aggregate C2-SD .................353 12.21 Comparison Between the 52-week (One-year) Expansions of the Different Aggregates and Levels of Calcined Clay Replacement.........................................353 12.22 Effect of Lithium Nitrate on C 1293 Expansions of Aggregate A4-ID ................357 12.23 Effect of Lithium Nitrate on C 1293 Expansions of Aggregate A2-WY .............357 12.24 Effect of Lithium Nitrate on C 1293 Expansions of Aggregate C2-SD ...............358 12.25 Comparison Between the 52-week (One-year) Expansions of the Different Aggregates and Levels of Lithium Nitrate Replacement ......................................358 12.26 Effect of Air Entrainment on C 1293 Expansions of Aggregate A4-ID ..............360 12.27 Effect of Air Entrainment on C 1293 Expansions of Aggregate A2-WY ............361 12.28 Effect of Air Entrainment on C 1293 Expansions of Aggregate C2-SD ..............361 12.29 Comparison Between the 52-week (One-year) Expansions of the Different Aggregates and Air Entrainment Contents............................................................362 12.30 Comparison Between the 52-week (One-year) Expansions of the Different Aggregates and Air Entrainment Contents of Table 12.15 ...................................366 12.31 Comparison Between the Standard One-Year Expansions and the Accelerated 13-Week Expansions of the Various Mitigation Alternatives...............................367 12.32 Effect of Class C Fly Ash on the Accelerated C 1293 Expansions of Aggregate A4-ID .................................................................................................369 12.33 Effect of Class C Fly Ash on the Accelerated C 1293 Expansions of Aggregate A2-WY ..............................................................................................370 12.34 Effect of Class C Fly Ash on the Accelerated C 1293 Expansions of Aggregate C2-SD ................................................................................................370 12.35 Effect of Class C Fly Ash on the Accelerated C 1293 Expansions of Aggregate E2-IA .................................................................................................371 12.36 Comparison Between the 26-Week Expansions Generated Using Accelerated C 1293 Procedures and the Different Class C Fly Ash Replacement ...................371 12.37 Effect of Class F Fly Ash on the Accelerated C 1293 Expansions of Aggregate A4-ID .................................................................................................375 12.38 Effect of Class F Fly Ash on the Accelerated C 1293 Expansions of Aggregate A2-WY ..............................................................................................375 12.39 Effect of Class F Fly Ash on the Accelerated C 1293 Expansions of Aggregate C2-SD ................................................................................................376 12.40 Effect of Class F Fly Ash on the Accelerated C 1293 Expansions of Aggregate E2-IA .................................................................................................376 12.41 Comparison Between the 26-Week Expansions Generated Using Accelerated C 1293 Procedures and the Different Class F Fly Ash Replacement ....................377
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12.42 Effect of Silica Fume on the Accelerated C 1293 Expansions of Aggregate A4-ID .................................................................................................380 12.43 Effect of Silica Fume on the Accelerated C 1293 Expansions of Aggregate A2-WY ..............................................................................................380 12.44 Effect of Silica Fume on the Accelerated C 1293 Expansions of Aggregate C2-SD ................................................................................................381 12.45 Effect of Silica Fume on the Accelerated C 1293 Expansions of Aggregate E2-IA .................................................................................................381 12.46 Comparison Between the 26-Week Expansions Generated Using Accelerated C 1293 Procedures and the Different Silica Fume Replacement ..........................382 12.47 Effect of Granulated Slag on the Accelerated C 1293 Expansions of Aggregate A4-ID .................................................................................................385 12.48 Effect of Granulated Slag on the Accelerated C 1293 Expansions of Aggregate A2-WY ..............................................................................................385 12.49 Effect of Granulated Slag on the Accelerated C 1293 Expansions of Aggregate C2-SD ................................................................................................386 12.50 Effect of Granulated Slag on the Accelerated C 1293 Expansions of Aggregate E2-IA .................................................................................................386 12.51 Comparison Between the 26-Week Expansions Generated Using Accelerated C 1293 Procedures and the Different Granulated Slag Replacement....................387 12.52 Effect of Calcined Clay on the Accelerated C 1293 Expansions of Aggregate A4-ID .................................................................................................390 12.53 Effect of Calcined Clay on the Accelerated C 1293 Expansions of Aggregate A2-WY ..............................................................................................390 12.54 Effect of Calcined Clay on the Accelerated C 1293 Expansions of Aggregate C2-SD ................................................................................................391 12.55 Effect of Calcined Clay on the Accelerated C 1293 Expansions of Aggregate E2-IA .................................................................................................391 12.56 Comparison Between the 26-Week Expansions Generated Using Accelerated C 1293 Procedures and the Different Calcined Clay Replacement.......................392 12.57 Effect of Lithium Nitarte on the Accelerated C 1293 Expansions of Aggregate A4-ID .................................................................................................395 12.58 Effect of Lithium Nitarte on the Accelerated C 1293 Expansions of Aggregate A2-WY ..............................................................................................395 12.59 Effect of Lithium Nitarte on the Accelerated C 1293 Expansions of Aggregate C2-SD ................................................................................................396 12.60 Effect of Lithium Nitarte on the Accelerated C 1293 Expansions of Aggregate E2-IA .................................................................................................396 12.61 Comparison Between the 26-Week Expansions Generated Using Accelerated C 1293 Procedures and the Different Lithium Nitarte Replacement.....................397 12.62 Effect of Air Entrainment on the Accelerated C 1293 Expansions of Aggregate A4-ID .................................................................................................400 12.63 Effect of Air Entrainment on the Accelerated C 1293 Expansions of Aggregate A2-WY ..............................................................................................400 12.64 Effect of Air Entrainment on the Accelerated C 1293 Expansions of Aggregate C2-SD ................................................................................................401
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12.65 Effect of Air Entrainment on the Accelerated C 1293 Expansions of Aggregate E2-IA .................................................................................................401 12.66 Comparison Between the 26-Week Expansions Generated Using Accelerated C 1293 Procedures and the Different Air Entrainment Replacement....................402 12.67 Effect of Different Cement Alkali Contents on the Accelerated C 1293 Expansions of Aggregate A6-NM.........................................................................405 12.68 Effect of Different Cement Alkali Contents on the Accelerated C 1293 Expansions of Aggregate A4-ID ...........................................................................405 12.69 Effect of Different Cement Alkali Contents on the Accelerated C 1293 Expansions of Aggregate A2-WY.........................................................................406 12.70 Effect of Different Cement Alkali Contents on the Accelerated C 1293 Expansions of Aggregate C2-SD ..........................................................................406 12.71 Comparison Between the 13-Week Accelerated C 1293 Expansions of Concrete Prisms Made with Different Na2Oequiv. Contents....................................407 12.72 Comparison Between the Different Mitigation Alternatives Used With Aggregate A4-ID and the Accelerated C 1293......................................................409 12.73 Comparison Between the Different Mitigation Alternatives Used With Aggregate A2-WY and the Accelerated C 1293 ...................................................409 12.74 Comparison Between the Different Mitigation Alternatives Used With Aggregate C2-SD and the Accelerated C 1293.....................................................410 12.75 Comparison Between the Different Mitigation Alternatives Used With Aggregate E2-IA and the Accelerated C 1293 ......................................................410 12.76 Effect of Silica Fume, Granulated Slag, and Calcined Clay on the Accelerated C 1293 Expansions Aggregate A6-NM Using 0.80% Na2Oequiv. Cement .............415 12.77 Effect of Class C Fly Ash and Class F Fly Ash on the Accelerated C 1293 Expansions of Aggregate A6-NM Using a 0.80% Na2Oequiv. Cement...................415 12.78 Effect of Lithium Nitrate and Air Entrainment on the Accelerated C 1293 Expansions of Aggregate A6-NM Using a 0.80% Na2Oequiv. Cement...................416 13.1 C 1260 Results vs. C 1293 Results.........................................................................422 13.2a Characterization of Aggregate Potential Alkali-Silica Reactivity ..........................425 13.2b Summary Characterization of Aggregate Potential AS Reactivity.........................426 13.3a Different Replacement Levels of Class C Fly Ash, Class F Fly Ash, Silica Fume, Slag, and Calcined Clay, Evaluated Using ASTM C 1260 and the Accelerated C 1293 Procedures (600C).................................................................431 13.3b Trend line Illustrating the Relation Between ASTM C 1260 and Accelerated C 1293 in Evaluating the Use of Class C Fly Ash, Class F Fly Ash, Silica Fume, Slag, and Calcined Clay .............................................................................432 13.4 Different Dosages of Air Entrainment and Lithium Nitrate, Evaluated Using ASTM C 1260 and the Accelerated C 1293 Procedures (600C) ..............................432 13.5 Comparison of the 14-Day C 1260 Expansions for the Different Entrained Air Levels ................................................................................................434 13.6 Comparison Between the 52-week (One-year) Expansions of the Different Aggregates and Air Entrainment Contents of Table 12.15 ......................................434 13.7 Comparison Between the 13-Week Expansions Generated Using the Accelerated C 1293 Procedures and the Different Air Entrainment .........................435 14.1 Flow Chart I for Assessing Aggregate’s Potential Alkali-Silica Reactivity..............440
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14.2 ASTM C 1260 Expansion Criteria Using Different NaOH Solution Molarities to Investigate Effectiveness of Cement Alkali Content ...........................................446 14.3 Flow Chart II for Determining Effective Preventive Measures.................................447 15.1 Characterization of Aggregate Potential Alkali-Silica Reactivity.............................454
1
CHAPTER ONE
INTRODUCTION
1.1 GENERAL
Alkali-silica reaction (ASR) is one of the most recognized deleterious phenomena
in concrete. ASR is a chemical reaction between the reactive silica contained in the
aggregates and the alkalis (Na2O and K2O) within the cement paste. The result is an
alkali-silicate gel that absorbs water and increases in volume. If the gel is confined
by the cement paste, it builds up pressure as it grows, causing internal stresses that
eventually might crack the concrete.
Identifying the susceptibility of an aggregate to alkali-silica reaction (ASR) before
using it in concrete is one of the most efficient practices for preventing damage.
Several tests have been developed to identify aggregates subject to ASR, but each
has its limitations. A three-year research study was initiated on January 1, 1998 at
The University of Texas at Austin for investigating ASR in portland cement
concrete. The study was approved by the ICAR Advisory Board of Directors in
November of 1997. The scope of the study is essentially two fold: 1) develop more
accurate testing protocols for identifying aggregates which are subject to ASR and 2)
develop mitigation methods for preventing ASR damage in concrete if a reactive
aggregate is used.
1.2 BACKGROUND AND PROJECT JUSTIFICATION
1.2.1 ASR Survey
In an effort to determine the incidence of ASR in the United States of America
(USA), a survey was conducted to get input from departments of transportation
(DOT’s) across the country. Figure 1.1 shows a summary of the survey.
ASR Occurrence
No ASR Reported
No ASR Problems Because of Low-alkali cement
No Response
2
Figure 1.1: Results of the DOT Survey on ASR
3
The survey will be detailed in a later chapter. All DOT’s were contacted; 39 DOT’s
responded. It was concluded that 31 states (79.5%) out of the 39 have at some point
experienced damage due to ASR. Eight states (20.5%) reportedly had never
experienced damage due to ASR and this was attributed to either the use of
innocuous aggregates or the use of low-alkali cements. The survey highlighted ASR
as a national concern.
1.2.2 Testing Procedures
Over the years, several ASTM tests have been developed for the purpose of
identifying reactive aggregates. The most popular tests include:
ASTM C 295: “Guide for Petrographic Examination of Aggregates for Concrete” is
used to determine the physical and mineralogical characteristics of aggregates. The
test is used to describe and classify the constituents of an aggregate, to determine the
relative amounts of the constituent in the aggregate, and to compare samples of
aggregates from new sources to samples of aggregates from other well-established
sources. Petrographic examination also provides a means of identifying types of
potentially deleterious minerals present in aggregates. The test method allows the
identification of most types of reactive silica minerals. However, a petrographic
examination will not clearly identify materials such as microcrystalline, strained, or
microfractured quartz, which can be found in a wide variety of aggregates. These
materials are usually present in aggregates that are slowly reactive.
ASTM C 227: “Test Method for Potential Alkali Reactivity of Cement-Aggregate
Combinations (Mortar-Bar Method)” has been the most widely used test method
since the 1950’s. The test is used to determine the susceptibility of cement-aggregate
combinations to alkali-silica reaction by means of measuring the change in length of
mortar bars made using the proposed combinations of materials for a job. Large
4
amounts of literature exist reporting on the inadequacy of this test method. Some
papers mentioned that the use of wicks in the storage container lead to alkali leaching
and misleading results. Other research projects have documented that the C 227 test
is not suitable for identifying slowly reactive aggregates. Other researchers have
complained that the processing of aggregates is not realistic; the processed
aggregates have different surface areas, which leads to different ASR reactivity and
does not represent the actual reactivity of an aggregate.
ASTM C 1260: “Test Method for Potential Reactivity of Aggregates (Mortar-Bar-
Test)” is used to detect the potential of aggregates in mortar bars for exhibiting
alkali-silica reaction within sixteen days. It does not investigate combinations of
aggregates with cementitious materials nor does it represent the environments to
which aggregates will be subjected in the field. The alkali content of the cement
does not affect the expansion in this test method because the specimens are stored in
a 1N NaOH solution. If mortar bars exhibit high expansion, it is recommended that
more information be gathered about the aggregate using ASTM C 295 to determine
whether the expansion is due to alkali-silica reaction. C 1260 is capable of detecting
slowly reactive aggregates. Several researchers have reported that the test is very
severe and might identify an aggregate as potentially reactive even if it has a very
good long-term service record. The test has considerable value in providing a rapid
means of detecting potentially ASR aggregates. Recently, aggregates have been
identified as innocuous using C 1260 but have reacted deleteriously in the field with
low-alkali cements. There are also some aggregates that have been identified as
reactive using C 1260 but have had over 30 years of good service records. As a
result, it is recommended that aggregate expansion results from this test be combined
with the results of a service record investigation for the aggregate in question or a
long-term concrete testing program.
5
ASTM C 1293: “Test Method for Concrete Aggregates by Determination of Length
Change of Concrete Due to Alkali-Silica Reaction” is used to determine the alkali-
silica reactivity of coarse and fine aggregates by monitoring the length change of
concrete prisms over a period of one year. It is used to predict the reactivity of an
aggregate in an alkaline environment (1.25% Na2O or 5.25 kg/m3) under laboratory
conditions that will differ from field conditions. As a result, the test does not
duplicate actual field performance. Results of this test should be used to decide
whether precautions should be taken to prevent alkali-silica reaction expansions
before the tested aggregate is used in construction. When expansions from this test
method indicate that the aggregate is reactive (one-year expansions greater than
0.04%) petrographic examination (ASTM C 856) is required to confirm that the
expansion is due to alkali-silica reaction. Supplemental testing could also be
performed to confirm the test results. Such tests include ASTM C 277, C 1260, C
295, and C 289.
Clearly, an ideal test method for predicting the alkali-silica reactivity of
aggregates does not exist. A comprehensive evaluation of test methods is needed for
aggregates having known alkali-silica reactivity ranging from innocuous to highly
reactive.
1.2.3 Mitigation Alternatives
Soon after ASR was first identified as the cause of several concrete failures, it was
found that the use of mineral admixtures as a replacement of a portion of the cement
in concrete could reduce the ASR effects on concrete. The most commonly used
admixtures are fly ash, silica fume, and slag. Several natural pozzolans such as
calcined clay have also been reported effective in mitigating the ASR effects. The
use of air entrainment and lithium admixtures in concrete has been proven to
potentially mitigate the effects of ASR. Effective mitigation methods need to be
6
available for use with aggregates that are prone to ASR. In order to reduce the cost
of construction, it is important that reactive aggregate sources be used as effectively
as possible.
1.3 PROJECT OBJECTIVES
The overall objective of the project was to closely examine the alkali-silica
reaction expansion potential in portland cement concrete containing different
aggregate sources in the United States (U.S.) and then to relate the results of the
laboratory testing performed on these aggregates to their reported field performance.
Another objective of the study was to investigate ASR mitigation or prevention
methods using aggregates with established ASR performance. Specific objectives
were as follows:
1. Improve the Testing Program for ASR Evaluation of Aggregates: This includes
investigating, modifying, or developing better interpretation techniques for
ASTM C 227, ASTM C 1260, and ASTM C 1293. A combination of the
improved tests was assembled to generate a recommended protocol for a better
ASR evaluation procedure for aggregates.
2. Improve Mitigation Methods: Using mortar bars and concrete prisms,
respectively ASTM C 1260 and C 1293, mitigation alternatives were
investigated. These alternatives included the use of fly ash, silica fume, ground-
granulated slag, calcined clay, lithium nitrate, air entrainment, low-alkali content,
and low permeability.
3. Improve Field Performance Recording: A database containing physical,
chemical, mineralogical, ASR expansion test results, and field performance for
7
each aggregate was initiated. The database helps improve the correct use of
aggregates in order to prevent ASR damage in concrete.
4. Implement Latest Findings: Final outputs of the project were presented at a
demonstration seminar at industry-selected sites.
1.4 WORK PLAN
A technical project advisory panel (PAP) was established to monitor the progress
of the research, to ensure effective use of resources, to act as a liaison between
researchers and industry members, to secure test samples, and to facilitate the
transfer of technology and prompt implementation. Twelve members representing
different sectors of the aggregates industry were chosen and added to the committee
after consultation. A list of the committee members is included in Appendix A. In
order to meet all the objectives of the project, six tasks were developed and
implemented. The list of tasks was as follows:
1. Task #1: Determine State-of-the-Art: The purpose of determining the state-of-
the-art was to identify areas in which research will be needed to fill the existing
gaps in the available ASR technology. The state-of-the-art will be determined by:
Extensive literature search
Survey of industry representatives such as the National Aggregates Association-
National Stone Association (NAA-NSA), and others.
Survey of knowledgeable professionals such as researchers, petrographers, and
consultants specializing in aggregates and concrete.
Survey of DOT’s in the United States and other selected countries.
2. Task #2: Identify and Select Test Materials: Based on available information on
field performance, chemical composition, and mineralogical composition,
8
sources of aggregates representing the complete spectrum of ASR reactivity
were selected for testing in the laboratory. In addition, the aggregates will
represent the various climatic regions and geographic areas of the U.S. Various
types of portland cement and admixtures were also selected to result in a
comprehensive testing program.
3. Task #3: Laboratory Test Program for Evaluating and Modifying Test
Procedures: An extensive laboratory test program was conducted to address the
different objectives of the study. ASTM test methods available to determine the
ASR reactivity of a specific aggregate include ASTM C 227, C 1260, C 1293,
and C 295. The objectives of the testing program are:
Evaluate the efficiency and accuracy of currently available ASTM test
procedures and document their limitations, disadvantages, and potentially
misleading predictions.
Identify a correlation or document a lack of correlation between the results of the
different tests investigated.
Identify a correlation or a lack of correlation between the results of each
investigated test and the documented performance in service of the aggregates
being tested.
Develop modifications to available test procedures in order to improve their
efficiency, accuracy, and predictability of the performance of a given aggregate
when used in concrete.
Evaluate and develop mitigation methods capable of reducing or eliminating the
ASR-related damage of concrete when using a reactive aggregate source.
Mitigation alternatives include the use of fly ash, slag, silica fume, blended
cements, air entrainment, low permeability, and lithium nitrate.
9
4. Task #4: Document the Field Performance of Investigated Aggregates: In
order to define the relationship between the laboratory and field performance the
field performance of investigated aggregates was documented. Methodology
included contacting the aggregate producers, DOT’s, and other authorities that
have used the aggregates.
5. Task #5: Establish Aggregate Database: A database was established to correlate
the laboratory results performed on a specific aggregate source to its field
performance in concrete.
6. Task #6: Develop Recommended Guidelines: Upon completion of the work on
previous tasks, guidelines were developed for:
Test protocols capable of accurately assessing the potential for ASR damage of
aggregate sources.
Mitigation methods for ASR-reactive aggregates that will be used in concrete.
Procedures for establishing acceptance of an aggregate source on the basis of
laboratory evaluation or mitigating mix designs.
7. Task #7: Implementation: Recommendations from the research were presented
to agencies that might have an interest in adopting all or a portion of the results.
8. Task #8: Reports: Reports were generated as the research progressed in the form
of quarterly reports, task completions, and final reports.
1.5 BENEFITS
Accurate evaluation of the potential ASR of aggregates is essential for producing
durable concrete. In the industry today, there is a need for improved or modified
testing procedures capable of accurately predicting the susceptibility of aggregates to
10
ASR. These new procedures will permit the use of some aggregates that have
formerly been excluded on the basis of being classified as reactive. Effective
mitigation methods will permit the economic use of reactive aggregates that normally
would be excluded. In summary, the improved testing procedures and mitigation
methods will result in two major benefits to the industry and users: 1) aggregates
previously erroneously classified as reactive can be used and 2) many reactive
aggregates can be used by incorporating the appropriate mitigation methods.
Mitigation of ASR will extend the life of concrete structures and result in
substantial savings in repair and replacement costs. Based on estimates by the Bridge
Design Section in New Mexico, 20 bridges per year are built and 50 to 75 percent
replaced due to ASR-related distress. It is estimated that by reducing rehabilitation
and replacement of bridges, about $11 million to $15 million annual savings would
accrue (Mc Keen, 1998).
Results of this study will increase the aggregate sources that can be used in
concrete, resulting in increased sales for producers and reduced costs for users. No
accurate estimates exist of the annual tonnage of aggregates that has been rejected
because of alleged susceptibility to ASR, but if the results of this research would
enable even 25 percent of these materials to be used, the increased volume available
for use would increase substantially.
11
CHAPTER TWO
ALKALI-SILICA REACTION MECHANISMS
2.1 GENERAL DEFINITION
Alkali-silica reaction (ASR) is a reaction that takes place between the reactive
silica contained in aggregates and the alkalis in the cement paste. For the reaction to
take place in concrete, three conditions must exist: high pH, moisture, and reactive
silica. Various types of silica present in aggregates react with the hydroxyl ions
present in the pore solution in concrete. The silica, now in solution, reacts with the
sodium (Na+) and potassium (K+) alkalis to form a volumetrically unstable alkali-
silica gel. Once formed, the gel starts imbibing water and swelling to a greater
volume than that of the reacted materials. Water absorbed by the gel can be water
not used in the hydration reaction of the cement, free water from rain, melted snow,
tides, rivers, or water condensed from air moisture (ACI 221, 1998). In general, the
reaction can be viewed as a two-step process (Farny, 1996):
Step 1:
Silica + alkali alkali-silica gel (sodium silicate)
SiO2 + 2NaOH + H2O Na2SiO3.2H2O (2KOH can replace 2NaOH)
Step 2
Gel reaction product + water expansion
Since the gel is restrained by the surrounding mortar, an osmotic pressure is
generated by the swelling. Once that pressure is larger than the tensile strength of
the concrete, cracks occur, leading to additional water migration or absorption and
additional gel swelling (ACI 221, 1998).
12
2.2 CONTRIBUTION OF THE SILICA TO THE REACTION
Various forms of silica or silicon oxide tetrahedron may be found in natural
aggregates. The silicon tetrahedron is shown in Figure 2.1 where Si4+ occupies the
center of the structure and four oxygen ions (O--), bonded to Si4+, occupy the corners
(Leming, 1996). A crystalline silicate structure is formed by the repetition of the
silicon tetrahedron in an oriented three-dimensional space (Prezzi et al., 1997).
Quartz (SiO2) is an example of completely crystalline silica where the different
tetrahedra are linked by oxygen ions. Each oxygen ion is bonded to two silicon ions
in order to achieve electrical neutrality. Figure 2.2 shows the structure of quartz. A
complete tetrahedron cannot form on the surface of a crystalline structure. The
bonds between oxygen and silicon are broken on the surface resulting in negative
charges that are unsatisfied (Prezzi et al., 1997). Such structures are chemically and
mechanically stable, impermeable, and react only on the surface (Leming, 1996).
Amorphous silicates (non-crystalline) are also formed by a combination of the silicon
tetrahedron with the exception that the tetrahedra are arranged in a random three-
dimensional network without forming a regular structure (Prezzi et al., 1997). As a
result, amorphous silica is more porous, has a large surface area, and as a
consequence is very reactive. The more amorphous the silica is, the more reactive it
becomes. Certain volcanic aggregates, for example, contain glassy materials formed
by the rapid cooling of melted silica that prevents it from crystallizing and renders it
very reactive (Leming,1996).
Figure 2.1: Silicon tetrahedron (Silica)
Figure 2.2: Quartz structure (SiO2) (Crystalline Structure)
13
In addition to the degree of crystallization of silica, the amount of energy stored in
the crystal structure also affects the reactivity of an aggregate. Some silica structures
might contain large amounts of strain energy caused by heat and pressure usually
called strained structure. Aggregates containing this type of silica are likely to be
susceptible to deleterious alkali-silica reactions. However, the rate of reaction is
much slower than that of aggregates containing amorphous silica. Metamorphic
aggregates containing strained quartz are an example of such aggregates (Leming,
1996).
Some aggregates contain crystalline silica formed by very fine crystals having
very large surface areas. These types of aggregates, such as chert, are prone to ASR
(Leming, 1996).
The amount of silica contained in aggregates also affects their reactivity as shown
in Figure 2.3 (ACI 221, 1998). There is a maximum amount of silica beyond which
the reaction does not take place, called the “pessimum effect.” Aggregates
containing the following amounts of silica are susceptible to ASR (ACI 221, 1998):
Opal: more than 5%
Chert and chalcedony: more than 3%
Strained or microcrystalline quartz: more than 5%. Examples are: granites,
granite gneiss, graywackes, argillites, phyllites, siltstones, and natural sands and
gravels
Natural volcanic glasses.
14
2.3 ALKALI CONTRIBUTION TO THE REACTION
Depending on the type of reactive silica contained in aggregates, the alkali-silica
reaction can be divided into two groups (CSA, 1994):
Group A: Alkali-silica reaction that occurs with amorphous (poorly crystalline)
silica minerals and volcanic or artificial glasses: Alkalis such as sodium (Na+) and
potassium (K+) present in the concrete paste will break the silica-oxygen bonds,
opening the crystal structure for alkalis and water. The result is a sodium silicate
hydrate (Na2SiO3.2H2O) that is very hygroscopic, capable of imbibing large amounts
of water that in turn results in swelling pressures which, if larger than the concrete
Reactive aggregate content: Percent by mass of total aggregate
0 20 40 60 80
0 1 2 3 4 5 6
A B C D
A,D = Reaction but no cracking B = Reaction, cracking C = Reaction, cracking, excess of
reactive silica
Reactive silica content: Percent by mass of total aggregate
Exp
ansi
on
Figure 2.3: Effect of Silica Content on ASR (West 1996)
15
tensile strength, will cause cracking. Cracks will allow the penetration of additional
water causing the swelling pressures to increase. This type of reaction is fairly fast
and can cause cracking within a few years.
Group B: Alkali-silica reaction that occurs with various variety of quartz such as
strained and fractured quartz: Aggregates in this group either contain moderately
reactive silica or contain a small amount of silica. Since the reactive silica in these
aggregates is localized at the surface, the resulting gel product is more stable because
of the presence of large amounts of calcium hydroxide at the interface between the
aggregate and paste. Porous aggregates are an exception, because the alkalis will
penetrate the aggregates causing a less stable gel to form away from the interface and
the calcium hydroxide. This process will cause the softening of the aggregates.
Damaging effects of this reaction on concrete are a slower and less obvious process
than the effects of Group A.
The higher the concentration of potassium and sodium alkalis in concrete the
higher the concentration of the hydroxyl ions (higher pH) and in turn the more
readily the silica will react with the hydroxyl ions (ACI 221, 1998). If all the
ingredients for the reaction are present in fresh concrete, then the gel can often be
detected at the interface between the aggregate and cement paste. Cracks will start
propagating from the aggregate particles. However, if the alkalis are provided from
an exterior source such as de-icing salts, seawater, and industrial solutions, then the
reaction will propagate from the exposed faces to the interior of the concrete (ACI
221, 1998).
16
CHAPTER THREE
REVIEW OF SELECTED NORTH AMERICAN RESEARCH
3.1 INTRODUCTION
This chapter includes a review of select research summarizing the latest
developments in the field of aggregate testing for potential ASR and ASR-mitigation
methods.
3.2 TESTING FOR POTENTIAL REACTIVITY OF AGGREGATES
Information gathered on the past field performance of aggregates might be the
most dependable method for predicting their alkali-silica reactivity in service.
However, field performance records may be inconclusive because (Bérubé and
Fournier, 1993):
1. The aggregate being evaluated might have been used in a limited number of
structures that are old enough or that are exposed to sufficient moisture.
2. There is a lack of information on mixture properties used with the aggregate such
as the cement alkali content, curing methods, etc.
3. The exposure conditions might change from the reference structure to the
structure being built.
4. There might be a variation in the aggregate production from the period the
reference structure has been built to when the new construction begins.
As a result of the above arguments, aggregates are often evaluated in the
laboratory under more controlled conditions. In addition, it may be necessary to
rapidly evaluate reactivity of aggregates before the aggregates are used in a structure,
which requires the need for test methods that are rapid, reliable, simple and
reproducible (Bérubé and Fournier, 1993).
17
In order to be able to predict, in less than one year, how an aggregate will react in
the field over many years, at least one of the following conditions must be increased
in a testing method (Bérubé and Fournier, 1993):
1. Alkali concentration: in the form of use of high-alkali cement or immersion in
alkaline solution.
2. Temperature: up to 380C, 800C, or autoclave.
3. Pressure: such as autoclave.
4. Humidity: either 100% RH or immersion in an aqueous solution.
5. Specific area: reducing the aggregates to powder or sand sizes
Bérubé and Fournier (1993) presented an extensive review of existing accelerated
testing procedures for predicting aggregate reactivity. The following is a summary of
some of the work and conclusions that they have referred to:
3.2.1 Petrographic Examination: ASTM C 295 (Bérubé and Fournier, 1993)
Examining thin sections of aggregates using an optical microscope is helpful in
detecting potentially reactive minerals that could cause damage. These minerals
include opal, cristobalite, tridymite, volcanic glass, chert, chalcedony, and
microcrystalline quartz (Dolar-Mantuani, 1983). In some cases, the petrographic
analysis can be completed using techniques such as X-ray diffraction, scanning
electron microscopy, or IR spectroscopy. Grattan-Bellew mentioned that
“petrographic examination alone cannot supply information on the expansiveness of
a particular cement-aggregate combination; however, experienced petrographers can
predict the likely behavior of aggregates with which they are familiar (Grattan-
Bellew, 1989).” Information from petrographic analysis could aid in determining
which accelerated testing method should be used to further evaluate the alkali-silica
reactivity of an aggregate.
18
3.2.2 Chemical Method: ASTM C 289 (Bérubé and Fournier, 1993)
This method consists of reducing the aggregate source to 150 to 300 µm particles
and then immersing it in a 1M NaOH solution at 800C for 24h. The solution is then
filtered and analyzed for the content of dissolved silica (Sc) and reduction in
alkalinity (Rc) both of which are plotted on a standard graph defining areas of
innocuous, deleterious, and potentially reactive aggregates.
Many aggregates are not adequately identified using this test. A significant
number of known alkali-silica reactive aggregates pass the test while many
innocuous aggregates are identified as deleterious. The poor performance of this
testing method can be blamed on 1) the interference of minerals such as calcium,
magnesium, silicates, gypson, zeolites, clay minerals, organic matter, or iron oxides
and 2) the crushing and preparation of the aggregates, especially with aggregates
containing microcrystalline quartz.
3.2.3 Mortar-bar method: ASTM C 227 (Bérubé and Fournier, 1993)
This test has proved to be incapable of predicting the alkali-silica reactivity of
many slowly reactive aggregates, namely, greywackes and argillites (Bérubé and
Fournier, 1993). The presence of wicks inside the storage containers, which differ
from one laboratory to another, has been shown to largely affect the results obtained
from this method. It was found that the wicks promote the leaching of alkalis from
mortar bars, causing lower expansions. As a result, a reactive aggregate ends up
being evaluated as an innocuous aggregate. It was also recommended that a reference
aggregate that does not release significant amounts of alkalis be included when
testing a new aggregate with unknown reactivity.
The alkali content of the cement used to make the mortar bars was also found to
largely affect the expansion results as shown in Figure 3.1. The cement alkali content
19
is not specified in the standard procedures of the test. A current practice that is being
used by many agencies is to increase the alkali content of the mortar bars to 1.25
percent Na2Oequiv. by adding NaOH to the mixing water.
0
0.02
0.04
0.06
0.08
0.1
0.12
0.14
0 2 4 6 8 10 12 14
Time, montths
AST
M C
227
Exp
ansi
ons,
%
0.66% Alkali Content1.03% Alkali Content1.25% Alkali Content
The water-cement ratio, which is not specified in the standard, was also found to
influence the expansion results as shown in Figure 3.2. Expansion increased with
decreasing water-cement ratio when the test was performed on typical reactive
aggregates from Quebec. This trend may be attributed to 1) a larger content of alkalis
caused by a lesser amount of pore solution or 2) a lower porosity, which leaves less
space for the reaction product to form (Bérubé and Fournier, 1993). On the other
hand, Kishitani et al. tested several Japanese aggregates and found that the C 227
expansions increased as the water-cement ratio increased (Kishitani et al., 1986).
Figure 3.1: Effect of alkali content (Percent Na2Oeq) in the ASTM C 227 mortar-bar method (Siliceous limestone from Ottawa, Ontario) (Bérubé and
Fournier, 1993)
20
When opal was tested using C 227, the effect of the water-cement ratio was also not
clearly defined (Grattan-Bellew, 1989).
0
0.02
0.04
0.06
0.08
0.1
0.12
0 2 4 6 8 10 12 14
Time, montths
AST
M C
227
Exp
ansi
ons,
%
W/C = 0.45W/C = 0.50W/C = 0.60
As a result of the survey, it was found that the storage condition, the water-cement
ratio, and the cement alkali content need to be controlled in order to produce more
reliable results. It was recommended to:
1. Use storage containers without wicks on the sides,
2. Increase the cement alkali content to 1.25% Na2Oeqiv.
3. Control the water-cement ratio to 0.50 by mass.
Figure 3.2: Effect of water-cement ratio in the ASTM C 227 mortar-bar method (Siliceous Limestone from Trois-Rivieres, Quebec) (Bérubé and
Fournier, 1993)
21
3.2.4 Accelerated Mortar-bar method: ASTM C 1260 (Bérubé and Fournier,
1993)
This test is being thoroughly investigated all over the world. In contrast to the
results of the C 227 test method, it was found that 14-day expansions decrease with
decreasing water-cement ratio. Since in this test mortar bars are immersed in a 1M
NaOH solution, the pore solution of the bars is controlled by the concentration of the
solution and the migration of the alkali ions in the bars is likely to decrease with
decreasing water-cement ratio.
It was also found that even though the test was capable of detecting numerous
aggregates, it was too severe for many aggregates that have performed well when
tested using the concrete prism method and that have performed well in the field. In
particular, these aggregates included greywackes, lithic gravels, some hornfelses,
gabbros, or andesites as shown in Figure 3.3.
Figure 3.3: Comparison Between ASTM C 1260 and ASTM C 1293 Results Illustrating the Severity of ASTM C 1260 (Bérubé and Fournier, 1993)
22
Several researchers including Grattan-Bellew and DeMerchant and Soles have
suggested using different expansion limits with varying aggregate types, namely,
0.10% for reactive siliceous limestone, 0.20% for greywackes, and 0.15% for the
other types of aggregates. These researchers have also called for performing a
petrographic examination before performing any accelerated testing in order to
determine which limit to use (Gratta-Bellew, 1990; DeMerchant and Soles, 1992).
ASTM C 1260 should not be used for rejecting aggregates. Negative results
should highlight the need for additional investigation. This test was found to be “very
useful, as it was capable of recognizing most deleterious aggregates within 2 weeks
only.” The test should be considered as a screening tool for aggregates. The reaction
products formed within tested mortar bars were exactly the same as those in field
concrete affected by the alkali-silica reaction (Shayan, 1989).
3.2.5 Autoclave Mortar-bar methods (Bérubé and Fournier, 1993)
The autoclave method that has been showing the most promising results consists
of forming mortar bars in accordance with ASTM C 227, but using a water-cement
ratio of 0.50 and an alkali content of 3.50 percent Na2Oequiv. The mortar bars are then
placed for 5 hours in an autoclave under 0.17 mPa (25 psi) at about 1300C.
When quarried silicate aggregates from Quebec were evaluated under the above
conditions, a proposed expansion limit of 0.10% expansion after 5 hours was found
to be acceptable, and the test was found to be more reliable than the accelerated
mortar bar test, ASTM C 1260. Limestones and dolostones have also been evaluated
using this test method. A proposed expansion limit of 0.15 percent after 5 hours
produced acceptable results that correlated to the field performance of aggregates.
Other aggregates were evaluated, and the results indicated that this autoclave method
23
is as reliable as C 1260. The only reactive aggregate that was not detected using the
autoclave was the same one that was not detected using the C 1260 procedures.
3.2.6 Concrete Prism Method CAN/CSA-A23.2-14A (ASTM C 1293) (Bérubé
and Fournier, 1993)
This test is recommended for all types of aggregates, and a limit of 0.040 percent
expansion after one year seems to be acceptable for all reactivity levels.
The expansion of concrete prisms under the environments of the test are affected by:
1. Water-cement ratio: For reactive limestone aggregates, the expansion decreases
as the water-cement ratio increases. Similar results were obtained when
greywackes and argillite aggregates were tested. This behavior was similar to the
one observed with the C 227 test, and the same reasoning can be applied to the
concrete test. Opposite results were observed when opaline aggregates were
tested. Other research studies have shown that by using 410 kg/m3 of cement to
make test prisms, the test was capable of predicting the potential reactivity of
aggregates to correspond to field-performance data (Grattan-Bellew, 1990).
2. Cement fineness: the finer the cement, the more rapidly the alkalis in the cement
are diluted, and the higher the expansions (Krell, 1986).
3. Storage conditions (temperature and humidity): The storage conditions have a
great deal of influence on the test results. Several research studies have
concluded that storing concrete prisms over water, in a sealed container with
wicks on the sides, at 100% R.H., and at 380C resulted in the most accurate
method for predicting potential reactivity of aggregates (Rogers and Hooton,
1989; Bérubé and Fournier, 1993, etc.)
24
3.2.7 Accelerated Concrete Prism Method (Used in Quebec) (Bérubé and
Fournier, 1993)
This test method consists of storing the concrete prisms in 1M NaOH solution at
800C. It was found that a limit of 0.04% after 24 days was adequate for identifying
most of the reactive aggregates but was too severe for several numbers of innocuous
aggregates. It was concluded that this test should only be used as a screening method
but not for rejecting aggregates. Testing cores taken from field structures under the
conditions of this test is a very useful method for rapidly identifying the reactivity of
the aggregates in the core.
3.2.8 The Duggan Test (Bérubé and Fournier, 1993)
Scott and Duggan proposed a testing procedure in which concrete prisms are cast
and submitted to accelerated curing. Small cores, 22-mm diameter by 50-mm length,
are taken from the prisms and subjected to cycles of immersion in distilled water at
210C. The cores are then heated in air at 820C after which the first reading is taken.
Subsequently the cores are stored in distilled water and periodic expansion readings
are taken. An expansion limit of 0.10% after 20 days of immersion is proposed as a
cut-off point between reactive and innocuous aggregates (Scott and Duggan, 1986).
The same researchers have proven in a later study that this test results in erroneous
aggregate characterization and is not adequate for alkali-silica reaction (Scott and
Duggan, 1990).
3.2.9 Conclusions of the Survey by Fournier and Bérubé
Table 3.1 includes a list of all testing procedures mentioned by Bérubé and
Fournier (1993). Three tests were recommended: 1) the petrographic examination, 2)
ASTM C 1260 because it was the only rapid method that is statistically dependable,
and 3) ASTM C 1293, which is required if the tested aggregate failed the
25
petrographic examination and caused excessive expansions using C 1260. A
summary of these tests is presented in Table 3.2 (Ativitavas, 1998).
Table 3.1: Testing Methods for Potential Aggregate Reactivity (Bérubé, 1993)
• Petrographic Method - ASTM C295 (≥ 1 day)
• Chemical Methods - ASTM C 289 Chemical Method (2-3 days) - Modified Chemical Method (ASTM C 289 on insoluble residues) (2-3
days) - German Dissolution Test (1 day) - Osmotic Cell Test (< 40 days) - Gel Pat Test (≥1 week) - Chemical Shrinkage Method (1 day)
• Mortar-Bar Methods - ASTM C 227 Method (6 months) -AFNOR P 18-585 Method (6 months) - CCA Method (6 months) - Danish Accelerated Method (5 months) - NBRI or ASTM C 1260 Accelerated Method (2 weeks) - Autoclave Methods (Chinese, Japanese, Canadian ) (≥ 3 days)
• Concrete-Prism Methods - CAN/CSA A 23.2-14A or ASTM C 1293 (1 year) - AFNOR P 18-587 Method (8 months) - South African Method (21-24 days) - BSI 812 Method (1 year) - CCA Method (6 months) - Accelerated Method (used in Quebec) (1 month) - Autoclave Methods
26
Table 3.2: Most Widely Used Aggregate Tests for Identifying ASR Reactivity (Ativitavas, 1998)
Test
Method
Procedure
Type of Sample
Criteria
Significant Points
ASTM C 227 Potential Alkali Reactivity of Cement-Aggregate Combinations (Mortar-Bar Method)
Mortar bars are stored over water at high relative humidity and 38ºC (100ºF). Expansions are measured at 14 days, 1, 2, 3, 4, 6, 8, and 12 months and every 6 months after that if necessary
At least 2 mortar bars with standard dimensions 25x25x285 mm (1x1x11-1/4 in)
- 1- year expansion > 0.10% = Reactive - 1-year expansion < 0.10% = Innocuous - 3-month expansion > 0.05% = Reactive - if 3-month expansion < 0.05% wait for the 1-year expansion
1. Low cost 2. Slow test (6-month) 3. Fails to detect slowly reactive
aggregates (expansion is too small). 4. Wicks create excessive leaching of
alkalis out of mortar resulting in expansion reduction
5. There is a reduction of aggregate size (not realistic)
6. Aggregate surface is not the same as that of aggregate in field structures
7. All papers concerning C 227 stated that it is too mild
8. Fournier, Bérubé (1992) modified the test by increasing alkali content to 1.25% Na2Oequiv. and using plastic pails instead of wicks
ASTM C 289 Potential Alkali-Silica Reactivity of Aggregates (Chemical method)
Crushed aggregates are reacted with alkaline solution at 80ºC (176ºF) during 24 hours. Amount of dissolved silica and reduction in alkalinity are measured
Three of 25-gr samples of crushed and sieved aggregate
Plot Sc and Rc on a graph and locate the aggregates in predetermined potentially deleterious or innocuous areas
1. Quick 2. Good for highly reactive aggregates 3. Fail for slowly reactive aggregates
such as gneiss, schist quartzite. 4. Complicated 5. Costs more than C 1293 and C 1260 6. Considerable amount of carbonate in
silicate aggregates could alter the results and underestimate Sc value
ASTM C 1260 Potential Alkali Reactivity of Aggregates (Accelerated mortar-bar method)
Mortar bars are immersed in 1N NaOH solution at 80ºC (176ºF) and expansions are measured at 4, 7, 11, and 14 days
At least 3 mortar bars with standard dimensions 25x25x285 mm (1x1x11-1/4 in)
- 14-day expansion <0.10% = Innocuous - 0.10% <14-day expansion < 0.20% = inconclusive - 14-day expansion > 0.20% = Reactive
1. Too severe; aggregates with good field performance may test reactive
2. Can detect slowly reactive aggregates 3. Fails to detect reactive granites,
gneisses which have microcrystalline quartz associated with strained quartz
4. Increase in alkali content of cement causes only small change
5. Reliable to evaluate the effectiveness of cementitious materials
6. If expansion > 0.10%, concrete prism test should be performed for confirmation
ASTM C 1293 Test Method for Concrete Aggregates by Determination of Length Change of Concrete Due to ASR
Concrete prisms are stored over water at 38ºC (100.4ºF). Expansions are measured at 7, 28, 56 days, and 3, 6, 9, 12 months and every 6 months after that if necessary
3 prisms per cement-aggregate combination with standard dimensions: 75x75x285 mm (3x3x11-1/4 in)
Expansion of 0.04% or more at one year indicates potentially deleteriously reactive
1. More realistic 2. Low cost 3. Slow test (1 year) 4. Is very much dependent on storage
conditions 5. The use of damp tissue to wrap each
prism placed in sealed plastic bags gave good results
6. Testing in 1M NaOH at 80ºC gave the most rapid expansion but is unreliable.
7. Testing in 1M NaCl caused a combination of at least two expansion mechanisms
8. Testing in 1M NaOH at 38ºC is recommended
ASTM C 295 Petrographic Examination of Aggregates for Concrete
Visual examination and analysis of the sample by microscopy or other methods such as X-ray diffraction, differential thermal analysis or electron microscopy
Core sample, thin sections, or pieces of aggregates
Appearance of dark rim at the surface of aggregate. Certain amount of reactive constituents
1. Reliability depends on the experience of petrographers
2. Analysis of aggregates before casting is useful
3. Performing additional tests is recommended
27
3.3 ASR MITIGATION MEASURES
Mitigating or preventing deleterious expansions caused by the alkali-silica
reaction can be achieved by:
1. Limiting moisture: The alkali-silica reaction will not take place in a concrete
structure if the internal relative humidity of the concrete is lower than 80%. As a
result, keeping the concrete dry will prevent the reaction from occurring.
However, this is practically impossible for exterior structures. Lowering the
permeability of concrete by reducing the water-cement ratio reduces the internal
moisture and delays the reaction. However, a low water-cement ratio results in a
higher cement content, higher alkali content, and a reduced pore space, which
could lead to higher expansions (ACI 221, 1998). Lowering the permeability of
concrete using mineral admixtures is a more viable approach to reducing the
deleterious effects of ASR (ACI 221, 1998). A protective coating for concrete is
a good solution provided that the coating is correctly applied. Because of the
high cost of concrete coatings, this method has been used on a limited basis.
2. Selecting Non-Reactive Aggregates: Using a non-reactive aggregate in concrete
and avoiding reactive aggregates will prevent ASR damage. This demands an
accurate testing protocol capable of correctly predicting the ASR reactivity of
aggregates. Such tests exist but need more refining and improvements (ACI 221,
1998). This is not economical in some regions where all locally available
aggregates are considered reactive.
3. Minimizing Alkalis: The most commonly used mitigation method is to control
the alkali content in the concrete for the purpose of reducing the hydroxyl ion
concentration and eventually the pH of the concrete. Cement is the major source
of alkali in the concrete. Alkalis are also provided, in smaller amounts, from fly
ash, mixing water, chemical admixtures, aggregates, and external sources such as
de-icing salts and seawater. Controlling the alkali content of the cement has been
proven to decrease the expansions caused by ASR. A proposed limit of 0.60%
28
has been recommended for the alkali content of cement to be used in concrete to
reduce ASR expansions (ACI 221, 1998).
4. Mineral Admixtures: Ever since the alkali-silica reaction was discovered,
researchers have reported on the effectiveness of mineral admixtures in reducing
its deleterious effects on concrete. Effective mineral admixtures include fly ash,
silica fume, ground granulated slag, and calcined clay. In addition, there exist
documents reporting structures over 25 years old containing reactive aggregates
and 20 to 30 percent fly ash. Mineral admixtures reduce ASR expansions by one
or more of the following mechanisms:
Reducing the alkali content of the concrete mix.
Reducing the pH of the concrete pore solution.
Consuming the calcium hydroxide, which might result in less swelling.
Reducing concrete permeability.
Testing for the effectiveness of mineral admixtures is a challenge. Researchers
have reported that ASTM C 441, Effectiveness of Fly Ash and Mineral Admixtures
in Reducing Deleterious ASR Expansions, is not a valid test for investigating the
effectiveness of mineral admixtures (ACI 221, 1998). ASTM C 1260 has been
successfully used for this purpose. If ASTM C 1293 is to be used, a two-year
period is recommended for obtaining the final expansion results (ACI 221, 1998).
5. Chemical Admixtures: Lithium salts have been used to prevent excessive ASR
expansions. Several salts have been tried, some of which have shown to be
effective. The best results were obtained using lithium nitrate (LiNO3) because
1) it is non-toxic and 2) minimal amounts were found to significantly reduce the
ASR expansions (ACI 221, 1998).
6. Air Entrainment: It was reported that adding 4% of entrained air to concrete
reduced the ASR expansions by 40%. It was also noticed that the expanding gel
had filled the air void system. However, this method has not yet been thoroughly
investigated nor has it been used in the field (ACI 221, 1998).
29
3.3.1 Minimizing Alkalis
The maximum limit of 0.60% Na2Oequivalent in cement was the result of a study
initiated in 1940 by Stanton of the California Division of Highways (Hill, 1996).
During the same period of time the Bureau of Reclamation imposed the same limit
on their “important” projects, basing their decision on the work conducted by Blanks
and Meissner in 1945. Although the Bureau of Reclamation concluded that a 0.50%
Na2O is a much safer limit, a 0.60% limit was considered adequately safe and more
economical. Several other research studies performed between 1941 and 1963,
namely, by Tremper (1941 and 1944), Kammer and Carlson (1941), Woolf (1952),
Bryant Mather (1952), and Oleson (1963), all concluded that cement with alkali
contents lower than 0.60% have shown very little to no ASR damaging effects (Hill,
1996).
Over the years, the 0.60% Na2Oequivalent limit in the cement has been proven to be
very effective in preventing concrete damage due to ASR. There are, however, some
instances where cements with Na2Oequivalent of less than 0.60% and even less than
0.40% have resulted in deleterious expansions due to ASR (Hill, 1996). In 1978,
Starks discovered concrete pavements in southeastern Wyoming and pavement
sidewalks in the Albuquerque, New Mexico area that had been deteriorated, in less
than 12 years, due to excessive ASR expansions. The alkali content of the cements
used for these projects was just under the 0.60% Na2Oequivalent limit. He also noticed
that some older structures in these areas constructed using cements with alkali
contents of about 0.48% have shown no ASR damage while some of them have
shown some map cracking. This fact was also noted by the first ASR researchers of
the 1940s who noticed that some aggregates might cause deleterious effects even
with very low-alkali-content cements (Hill, 1996).
30
While the emphasis in the United States was concentrated on limiting the alkali
content of the cement, some of the western European countries as well as Canada
were trying to limit the alkali content of the concrete including alkalis from the
cement, aggregates, mineral, and chemical admixtures (Hill, 1996).
Since there is a large diversity in natural aggregates, there is no magic number
that can be specified for the alkali limit of cement in order to prevent alkali-silica
reaction in concrete. A combination of measures might have to be employed to
prevent the reaction and that includes the use of low alkali cement in combination
with a mineral admixture (Hill, 1996).
3.3.2 Effectiveness of Supplementary Cementing Materials
The effectiveness of supplementary cementing materials (SCM) in suppressing
ASR in concrete has been a subject for extensive research for a long time. Various
researchers and authors have reported opposing results on their effectiveness mainly
because of the wide range of available fly ash types and the different properties and
reactivity of aggregates being investigated (Shayan et al., 1996).
To minimize the risk of damage due to alkali-aggregate reaction in concrete
containing reactive aggregates, current UK guidelines permit the use of fly ash.
However, definite advice on the use of fly ash in concrete and on percentages to use
is not included in the guidelines because there exists conflicting evidence regarding
the alkali content of the fly ash and whether these are available for reacting with the
aggregate causing additional ASR damage (Thomas, Blackwell, and Nixon; 1996).
This is especially a concern when the total alkali content of the concrete is being
controlled below a certain level in order to prevent ASR damage. Several
recommendations exist on how to deal with the alkali content of fly ash, including
(Thomas, Blackwell, and Nixon; 1996):
31
1. The Concrete Society (UK) recommends using the water-soluble alkali content of
the fly ash for determining the total alkali content of the concrete, and
2. The Building Research Establishment (UK), Department of Transport (UK),
French Guidelines, and Ireland guidelines recommend using one-sixth of the total
alkali content of the fly ash to calculate the total alkali content of the concrete.
This is a more conservative approach since 0.40% to 0.70% Na2Oequiv. is
equivalent to 0.10% water-soluble alkali content.
Evidence from the literature show that the use of sufficient levels of Class F fly
ash is effective in preventing ASR expansions in concretes containing natural
reactive aggregates even when the alkalis from sources other than the fly ash are
enough to cause deleterious expansions in concretes without any fly ash (Thomas et
al., 1996). In this case, the fly ash is considered to have a positive effect and to have
no reactive alkali contribution. However, when moderate levels of fly ash are used
in concrete containing very highly reactive aggregates with low alkali content
cements, then the fly ash will likely contribute alkalis to the reaction. In this case,
higher replacement levels may be required in order for the fly ash to completely
prevent the reaction from causing damage (Thomas, Blackwell, and Nixon; 1996).
In order to clarify these matters, Thomas, Blackwell, and Nixon (1996) reported
about a study where five reactive aggregate sources from the UK area were
investigated. Aggregates were used to make concrete specimens using one high-
alkali portland cement (1.15% Na2Oequiv.) and three Class F fly ashes with varying
total alkali content (2.98, 3.46, and 3.86% Na2Oequiv.). Fly ash was used at different
replacement levels and concrete prisms were stored in plastic containers at 200C and
100% relative humidity. At 7 days, initial length measurements of all prisms were
taken before wrapping them in moist toweling and polyethylene. Some of the
wrapped prisms were stored at 200C while some were stored at 380C all at 100%
32
humidity. For the particular materials used in this study (UK reactive aggregates and
UK Cement and Class F fly ash) it was determined that (Thomas, Blackwell, and
Nixon; 1996):
1. The effective alkali contribution of the ash depends upon the nature of the
reactive aggregate and the levels at which the weight of cement is replaced with
the fly ash (Figures 3.4 and 3.5).
2. The alkali content of concrete in the control specimens (neglecting the alkalis in
the fly ash) was enough to cause deleterious expansions and cracking of
specimens containing moderately reactive flint. Replacing the cement with 25%
fly ash was effective in reducing expansions. As a result, it was noted that the fly
ash has a positive effect in reducing damage due to AAR and does more then just
dilute the alkalis in the cement. Using the same reactive aggregate but replacing
6% of the cement with fly ash resulted in an increase in expansions for a given
cement alkali content. It was determined that 40% of the total alkalis in the fly
ash contributed to the expansions of concrete specimens. These matters are
illustrated in Figures 3.6 and 3.7.
3. Replacing 25% of the cement weight with fly ash was not effective in preventing
excessive expansions and cracking of specimens containing highly reactive
aggregates (e.g. aggregates that cause deleterious expansions with low-alkali-
content cement). These aggregates required using 35% fly ash by weight. The
contribution of the total alkalis in the fly ash to the expansions was estimated to
be 10%. This is illustrated in Figure 3.8.
4. It is inappropriate to use a single value (e.g. one-sixth of the total alkali content in
ash) to estimate the contribution of the alkalis of the fly ash to the rate of ASR. It
is dependent upon the aggregate nature and levels of replacements. In addition,
using this approach ignores mechanisms, other than the alkali availability, that
contributes to the efficiency of the fly ash in reducing ASR damage.
33
0
20
40
60
80
100
2 3 4 5 6
Threshold alkali content for expansion in OPC concrete: kg/m3 Na2Oequiv.
Eff
ectiv
e al
kali
cont
ribu
tion
from
fly
ash:
%to
tal a
lkal
i Cristobalite
Greywacke
Siltstone/Siliceous limestoneThames Valley Sand
6% fly ash
25% fly ash35-40% fly ash
Figure 3.4: Effect of Aggregate Reactivity and Percent Fly Ash Replacement on the Effective Alkali Contribution from Fly Ash
(Thomas, Blackwell, and Nixon; 1996) OPC = Portland Cement Concrete with No Additives
34
0
10
20
30
40
50
60
70
80
90
100
0 5 10 15 20 25 30 35 40
Replacement Level: %
Eff
ectiv
e al
kali
cont
ribu
tion
from
fly
ash:
% to
tal a
lka
CristobaliteSiltstone/ Siliceous Limestone
Thames Valley Sand
Moderately Reactive
Highly Reactive
Figure 3.5: Effect of Aggregate Reactivity on the Effective Alkali Contribution from Fly Ash (Thomas, Blackwell, and Nixon; 1996)
35
0
0.1
0.2
0.3
0.4
3 4 5 6 7
OPC alkali content: kg/m^3 Na2Oequiv.
Exp
ansi
on a
t 4 y
ears
: %
Control - (no fly ash)25% F125% F225% F3
0
0.1
0.2
0.3
0.4
3 4 5 6 7
OPC alkali content: kg/m^3 Na2Oequiv.
Exp
ansi
on a
t 3 to
4 y
ears
: %
Control - (no fly ash)
6% F1
Figure 3.6: Using 25% Class F Fly Ash to Prevent Cracking of Concrete Made with a Moderately Reactive Aggregate (Flint) (Thomas, et al.; 1996)
OPC = Portland Cement Concrete with No Additives
Figure 3.7: Effect of Using 6% Class F Fly Ash with a Moderately Reactive Aggregate (flint) (Thomas, Blackwell, and Nixon; 1996)
OPC = Portland Cement Concrete with No Additives
36
0
0.1
0.2
0.3
0.4
0 2 4 6 8
OPC alkali content: kg/m^3 Na2Oequiv.
Exp
ansi
on: %
Control - 3 years25% F3 - 4 years35% F3 - 4 years
Specifications for using fly ash as an ASR mitigation alternative should take into
consideration that highly reactive aggregates require higher amounts of fly ash in the
mixture. As the calcium content of the fly ash increases (Class C fly ash), the
amounts of the fly ash used in the concrete should also be increased.
Pepper and Mather (1952) found that any deleterious expansion caused by ASR
can be eliminated by the use of a range of fly ash and other mineral admixtures.
Nixon and Gaze (1983), Nixon et al. (1986), and Stark (1978) investigated the
effectiveness of fly ash with slowly reactive aggregates and concluded that when 20
or 30% of the weight of cement was replaced with Class F fly ash, deleterious ASR
expansions were eliminated.
Figure 3.8: Effect of Class F Fly Ash on Cracking of Concrete Made with a Highly Reactive Aggregate (Thomas, Blackwell, and Nixon; 1996)
OPC = Portland Cement Concrete with No Additives
37
Factors that influence the effectiveness of fly ash in mitigating ASR include the
composition of the cement and fly ash, levels of replacement and the fineness of the
admixture. Dunstan (1981) found that while 25% fly ash addition was effective in
reducing ASR expansion, 5 to10% addition resulted in increasing the expansions
depending on the alkali content of the cement. Thomas et al. (1991) found that when
high-alkali fly ash was used to replace 20% or more of the weight of cement in
concrete specimens containing a very reactive aggregate, ASR was greatly reduced
and very little evidence of the reaction was recorded. Blackwell et al. (1992) showed
that a Class F fly ash with 4.0% Na2Oequivalent was effective in preventing excessive
ASR expansions in concrete specimens made with a reactive greywacke and a high
alkali content concrete (7.0 kg Na2Oequivalent/m3). A 30-year testing program was
presented by Thomas et al. in 1992 which provided long-term evidence on the
effectiveness of 20% to 30% of a high alkali Class F fly ash in preventing ASR
cracking in a dam structure containing a reactive greywacke. Portions of the dam
that were constructed without the use of fly ash showed extensive ASR cracking.
To determine the effectiveness of fly ash, Hobbs (1994) conducted a study using a
very reactive synthetic cristobalite aggregate. He concluded that ASR expansion
depended upon 1) the alkali content of the cement (0.60-1.20% Na2Oequiv.), 2) the
alkali content of the fly ash (3.0-3.9% Na2Oequiv.), and 3) the level of replacement. He
found that the alkali contribution from Class F fly ash depended upon the level of
replacement as indicated in Table 3.3. The effect of Class F fly ash is illustrated in
Figure 3.9.
38
Table 3.3: Alkali Contribution from Fly Ash: Concrete with Cristobalite (Highly Reactive) (Hobbs, 1994)
Alkali Contribution from fly ash: % Total alkali content
Cement Alkali:% Na2Oequiv.
6% Ash Class F
25% Ash Class F
40% Ash Class F
0.6 100 16 9 0.9 100 11 3 1.2 60 0 0
Figure 3.9: Effect of Class F Fly Ash on Expansions of Concrete Containing a Highly Reactive Aggregate (Cristobalite) (Hobbs, 1994)
OPC = Portland Cement Concrete with No Fly Ash
39
The calcium content of fly ash (Class C fly ash) also plays a role in its
effectiveness in suppressing ASR. Lee (1989) suggested that ASR expansions are
dependent upon the specific Na2O/SiO2 ratio of the fly ash. Nagataki et al., 1991,
investigated eight different fly ashes using high alkali cement and pyrex glass as a
reactive aggregate. They concluded that the ASR expansions were related to the
amount of soluble alkali and amorphous SiO2 content of the fly ashes as well as their
fineness. The reaction can be controlled by using finer SiO2 ashes with higher
amount of amorphous SiO2, and higher replacement levels. This is illustrated in
Table 3.4 and Figures 3.10 through 3.12, where it can be seen that fly ash F was the
most effective and had the finest SiO2 and the highest amount of amorphous SiO2.
They also concluded that the total alkali content of the fly ashes did not have any
effect in controlling ASR expansions.
Table 3.4: Chemical Compositions of three Investigated Ashes (Nagataki et al., 1991)
Fly Ash A Fly Ash B Fly Ash F L.O.I 3.12 2.54 5.09 SiO2 55.7 66.0 61.1 Al2O3 25.1 24.2 20.4 Fe2O3 6.14 3.15 5.72 CaO 2.55 1.44 1.99 MgO 2.19 0.38 1.48 SO3 0.76 0.06 0.78 TiO2 13.2 1.37 0.96 Na2O 1.54 0.32 0.66 K2O 1.21 0.28 1.53
Na2Oequiv. 2.34 0.50 1.67 Amorphous
SiO2 49.8 40.0 51.3
Mean Diameter 23.0 28.5 13.1
40
Fly Ash A
0
1000
2000
3000
4000
5000
6000
7000
0 10 20 30
Replacement Ratio of Fly Ash (%)
Exp
ansi
on 84 day56 day28 day14 day7 day3 day
Fly Ash B
0100020003000400050006000700080009000
0 10 20 30
Replacement Ratio of Fly Ash (%)
Exp
ansi
on 84 day56 day28 day14 day7 day3 day
Figure 3.10: Effect of Replacement Levels of Fly Ash A on ASR Expansions (Nagataki et al., 1991)
Figure 3.11: Effect of Replacement Levels of Fly Ash B on ASR Expansions (Nagataki et al., 1991)
41
Fly Ash C
0
1000
2000
3000
4000
5000
6000
7000
0 10 20 30
Replacement Ratio of Fly Ash (%)
Exp
ansi
on 84 day56 day28 day14 day7 day3 day
Thomas (1996) investigated three concrete structures containing alkali-silica
reactive aggregates and Class F fly ash. Two dams were constructed using reactive
greywacke aggregates and Class F fly ash replacing 20 to 30 percent of the weight of
cement and one dam was constructed using similar reactive aggregates but without
fly ash. The investigation indicated that the structures containing fly ash were in
great condition even after 25 years in service while the structure with no fly ash
exhibited ASR damage. In addition, the dam structure with no fly ash had a concrete
pore solution with an alkali concentration below 3 kg/m3 whereas both concrete
dams with fly ash had alkali contents in excess of this value. Based on these findings
it was concluded that Class F fly ash could be successfully used to prevent ASR if it
was used at sufficient levels of cement replacement. “The findings from this study
cannot be extended to Class C fly ash.” (Thomas, 1996)
Figure 3.12: Effect of Replacement Levels of Fly Ash F on ASR Expansions (Nagataki et al., 1991)
42
Investigations performed before the construction of the Tallowa Dam, Australia,
indicated that the local aggregate was deleterious with regard to alkali-aggregate
reaction. (Shayan et al., 1993) As a result, a cement with an alkali content lower than
0.60% in addition to fly ash were incorporated into the concrete to prevent the ASR
damage from occurring. After more than 23 years of service life, the dam has still
not shown signs of ASR damage and is expected to continue the good performance
in the future. Aggregates separated from cores taken in 1995 were determined to be
alkali-silica reactive using ASTM C 1260. Even though the dam contained
potentially reactive aggregate, the combination of low alkali cement and fly ash has
proven to work in preventing damage due to ASR. Table 3.5 includes the chemical
properties of the cement and fly ash used in the structure and Figure 3.13 show the C
1260 results generated using cores from the dam. The concrete used for the
construction of the dam had the following proportions:
Maximum aggregate size 150 mm Cement Content 119 kg/m3 Fly Ash Content 59 kg/m3 Water/(cement + fly ash) ratio 0.50 Specified compressive strength (1 year) 13.8 MPa Actual mean cylinder strength (28 days) 15.8 MPa
(90 days) 21.8 MPa (1 year) 29.6 Mpa
Table 3.5: Tallowa Dam Cement and Fly Ash Properties (Shayan et al. 1993)
Oxide (%)
Portland Cement
Fly Ash SiO2 23.4 58.3 Al2O3 4.5 Fe2O3 5.0 34.6
CaO 63.4 1.5 MgO 0.6 1.1 Na2O 0.04 K2O 0.44 0.71 Soluble
SO3 2.0 0.19 Na2O equivalent 0.33 --- Loss on Ignition 1.1 3.6
43
Hanks and Young (1992) found that 15, 22.5 and 30% cement replacement levels
with Class F fly ash were effective in reducing the 14-day expansions of mortar bars
made with two known reactive aggregates below 0.10% when tested in accordance
with ASTM C 1260. The 7.5% replacement level was not effective and showed 14-
day expansions greater than 0.20%. This is illustrated in Figure 3.14 for one of the
tested aggregates.
Figure 3.13: Expansion Curves for Concrete Cores Taken from Several Locations of the Dam and Stored in a 1M NaOH Solution at 400C
(Shayan et al., 1996)
44
Kakodkar et al. (1997) used the accelerated mortar bar test, ASTM C 1260, to
investigate the effectiveness of five Class C fly ashes in reducing ASR in mortar bars
incorporating five different sands, one highly reactive and four slowly reactive.
Mortar bars were cast using the different aggregates and replacing 10, 15, 20, 25, and
30% of the cement with the different Class C fly ashes shown in Table 3.6.
Conclusions were as follows:
1. The addition of Class C fly ashes at any level caused a decrease in the expansions
of mortar formed with highly reactive aggregates. When appropriate levels were
used, the expansion of mortar bars decreased below the test limit.
Figure 3.14: ASTM C 1260 Expansions vs. Replacement Levels of Cement with Class F Fly Ash (Hanks and Young, 1992)
45
2. When Class C fly ash is used with slowly reactive aggregates, there is a limit
replacement level (about 15 or 20 percent) below which the ash will cause an
increase in the 14-day expansions.
3. The oxide content of the fly ashes had an influence on ASR expansions. Low-
oxide fly ashes (53.3 percent) were not effective in reducing the expansion of
mortar bars made using highly and slowly reactive aggregates. As the oxide
content increased the effectiveness of the fly ashes was slightly improved causing
a greater decrease in expansions.
4. The alkali content of the fly ashes did not seem to affect their effectiveness in
preventing expansions due to ASR in mortar bars containing highly and slowly
reactive aggregates.
5. Results are illustrated in Figures 3.15 and 3.16 which show the expansions of one
slowly reactive and one highly reactive aggregate.
Table 3.6: Composition of Class C Fly Ashes (Kakodkar et al., 1997) Fly Ash
#1 Fly Ash
#2 Fly Ash
#3 Fly Ash
#4 Fly Ash
#5 SiO2 36.5 32.8 29.9 35.1 46.7 Al2O3 20.8 20.0 17.7 20.3 13.4 Fe2O3 6.6 5.9 5.7 6.4 8.3
SiO2+ Al2O3+ Fe2O3 63.9 58.7 53.3 61.8 68.4 SO3 1.3 3.5 4.3 1.9 1.4 CaO 23.5 26.9 30.1 23.6 18.7 MgO 4.3 4.7 7.1 4.2 -- Na2O 1.12 0.77 1.70 1.92 --
Moisture Content 0.0 0.1 0.1 0.0 0.02 Loss on Ignition 0.1 0.4 0.2 0.2 0.02
46
00.050.1
0.150.2
0.250.3
0.350.4
0.45
0 10 15 20 25 30
Pecentage Fly Ash
14-D
ay E
xpan
sion
, %
Fly Ash #1Fly Ash #2Fly Ash #3Fly Ash #4
Innocuous
Slowly Reactive
Highly Reactive
0
0.05
0.1
0.15
0.2
0.25
0.3
0.35
0.4
0 10 15 20 25 30
Pecentage Fly Ash
14-D
ay E
xpan
sion
, % Fly Ash #1Fly Ash #2Fly Ash #3Fly Ash #4Fly Ash #5
Innocuous
Slowly Reactive
Highly Reactive
Figure 3.15: Comparison of 14-Day Expansions of Mortar Bars Made with the Different Fly Ashes and a Slowly Reactive Aggregate (Kakodkar et al., 1997)
Figure 3.16: Comparison of 14-Day Expansions of Mortar Bars Made with the Different Fly Ashes and a Highly Reactive Aggregate (Kakodkar et al., 1997)
47
Johnston et al. (1997) also used ASTM C 1260 to investigate the effectiveness of
Class F fly ash and ten natural pozzolans in preventing deleterious expansions caused
by the alkali-silica reaction. A 14-day expansion lower than 0.10% was the criteria
for innocuous expansions. The results of the study are summarized as follows:
1. More than 25% of the cement had to be replaced with Class F fly ash in order to
effectively reduce ASR expansions of mortar bars made with a highly reactive
sand below 0.10% as seen in Figure 3.17.
0
0.05
0.1
0.15
0.2
0.25
0 10 15 20 25 30
Pecentage Fly Ash
14-D
ay E
xpan
sion
, %
Innocuous
Slowly Reactive
Highly Reactive
2. All investigated natural pozzolans were able to reduce ASR expansions for the
exception of one pozzolan, a white volcanic ash (VA2 in Table 3.7), which
actually increased the mortar-bar expansions as seen in Figure 3.18.
3. Two natural pozzolans (LK2 and PS1E in Table 3.7), a gray, highly siliceous
fire-clay and a dark brown to black, non-calcareous shale, were the most
effective in controlling ASR expansions at levels of cement replacement between
Figure 3.17: Effect of Class F Fly Ash on the 14-Day Expansions of Mortar Bars Made with a Highly Reactive Aggregates and Tested Using ASTM C 1260
(Johnston et al., 1997)
48
15 and 25 percent by weight. Replacing the cement with 10% pozzolans was not
effective in preventing ASR excessive expansions above the test limit. Both
pozzolans were more effective than the investigated Class F fly ash in controlling
ASR expansions as seen in Figure 3.18.
Table 3.7: Composition of Selective Natural Pozzolans Tested by Johnston et al. (1997)
VA1 LK2 PS1E SiO2 -- 79.94 58.98 Al2O3 -- 7.58 16.59 Fe2O3 -- 1.11 6.29 CaO -- 0.25 1.57 MgO -- 0.15 2.11 Na2O 0.34 0.01 0.02 K2O 5.98 1.53 4.53 TiO2 -- 0.35 0.70 SO3 -- 0.13 1.01
MnO -- -- 0.05 BaO -- -- 0.05 NiO -- -- -- H2O -- 0.81 0.15
L.O.I. -- 4.37 1.10 Description White pure
ash Silicified volcanic
tuff Brown shale, expanded Pierre shale by
kiln heating
49
0
0.05
0.1
0.15
0.2
0.25
0.3
0.35
0 10 15 25
Pecentage Fly Ash
14-D
ay E
xpan
sion
, %
VA2PS1ELK2
Innocuous
Slowly Reactive
Highly Reactive
Alasali and Malhotra (1991) evaluated the effectiveness of high volume Class F
fly ash in preventing ASR damage caused by excessive expansions. Concrete
specimens were made using Class F fly ash with 58% of the weight of cement
replaced and a water-cementitious materials ratio of 0.31. NaOH was added to the
mixing water in order to increase the alkali content of the concrete. Concrete
specimens were stored under different curing conditions, namely, moist room at 230C
dry and wet cycles at 380C, in water at 380C, in 5% NaCl solution at 380C, in 1M
NaOH solution at 380C, in 1M KOH solution at 380C, in 5% NaCl solution at 800C,
in 1M NaOH solution at 800C, and in 1M KOH solution at 800C. Expansion
measurements were carried out for 275 days. It was concluded that expansions of
concrete prisms made with 58% Class F fly ash were insignificant regardless of the
test method used and of the addition of NaOH to the mixing water. Figure 3.19 is an
Figure 3.18: Effect of Selective Natural Pozzolans on the 14-Day Expansions of Mortar Bars Made with a Highly Reactive Aggregates and Tested Using ASTM
C 1260 (Johnston et al., 1997)
50
example of the expansions generated when concrete prisms were stored in a 1M
NaOH solution at 380C.
-0.02
0
0.02
0.04
0.06
0.08
0.1
0.12
0.14
0 100 200 300
Age, Days
Exp
ansi
on, %
No Fly Ash
No Fly Ash + Alkali
Cement + Fly Ash
Cement + Fly Ash +Alkali
The Canada Center for Mineral and Energy Technology (CANMET), under
contract to Lafarge (Canada), investigated the effectiveness of 15 fly ashes, slags,
condensed silica fume, and natural pozzolans in reducing expansion of concrete and
mortar caused by alkali-aggregate reaction. Two reactive siliceous aggregates were
used in combination with the cementitious materials and high-alkali-content cement
and results were compared to expansion of specimens made with low-alkali-content
cement. Expansions were monitored over a five-year period. Properties of
investigated fly ashes are included in Table 3.8, and properties for investigated silica
fume, natural pozzolan, and slag are included in Table 3.9.
Figure 3.19: Expansions of Concrete Prisms Made Using a Cement with 1.13% Alkalis, a Reactive Aggregate (Spratt), and 58% Class F Fly Ash. Prisms were Stored in a 1M NaOH Solution at 380C (Alasali et al., 1991)
51
Table 3.8: Properties of Investigated Fly Ashes (Chen et al., 1993)
Table 3.9: Properties of Investigated Silica Fume, Natural Pozzolan, and Slag (Chen et al., 1993)
52
It was concluded that (Chen et al., 1993):
1. The desirable characteristics of a cementitious material for reducing ASR
expansions due to AAR are:
a) low-alkali content
b) high-45-µm fraction
c) high total acidic oxides (SiO2 + Al2O3 +Fe2O3).
2. ASTM C 441 and ASTM C 618 are not reliable in assessing the effectiveness of
cementitious materials in mitigating ASR.
3. From the materials listed in Tables 3.8 and 3.9, only several were effective in
decreasing expansions below testing limits. Findings for the effective materials
are summarized in Table 3.10. It should be noted that only Class F fly ashes were
effective in decreasing expansions below a safe limit and that none of the
investigated Class C ashes were effective in doing so.
Table 3.10: Effective Levels of Replacements for Materials Effective in Mitigating ASR Damage (Chen et al., 1993)
Refer to Table 3.8 And Table 3.9
Pessimum %Replacement
Effective % Replacement
Critical alkali as solubleNa2O (kg/m3)
Lingan fly ash Class F
10 40 3.5
Dalhousie fly ash Class F
10 40 3.3
Sundance fly ash Class F
10 40 3.2
Lakeview fly ash Class F
10 40 3.4
Standard Slag 35 65 1.9 Atlantic Slag 35 65 1.9 SKW condensed silica fume
5 15 4.7
Amherst natural pozzolan
10 30 3.9
53
4. The effectiveness of the cementitious materials in reducing expansions was
coupled with a reduction of compressive strength of concrete. Fly ashes that were
effective in reducing ASR, especially at 50% cement replacement level, resulted
in lower compressive strengths. The reduction was greater in the 28-day strength
than the 84-day strength. Fly ashes that were not effective in reducing ASR
expansion either increased concrete strength or maintained the same strength of
the control concrete. Silica fume and natural pozzolans that were effective in
reducing ASR expansions resulted in a substantial increase in 28- and 84-day
strengths. When cement was replaced with 65% slag, the ASR expansions were
lower than testing limits; however, the concrete strength was decreased.
A study was conducted at King Fahd University of Petroleum and Minerals in
Dhahran, Saudi Arabia. Using ASTM C 441 and ASTM C 227 the following
conclusions were drawn (Rasheedbuzafar, 1991):
1. Replacing cement with 10 to 20% silica fume or 60 to 70% slag reduced the C
227 6-month expansions below the limit of 0.10% as seen in Figure 3.20.
2. There is a strong indication that the mechanism by which the silica fume and slag
reduce ASR expansion is through lowering the hydroxide ion concentration in the
pore solution. However, there are also some deviations that indicate that other
mechanisms are taking place.
3. When used with low-alkali cements, 60% of slag was found to be very effective
in removing alkalis from the pore solution and thus reducing ASR expansions.
When using comparable alkali contents of cements, 60% slag had similar effects
to 10% silica fume. As the alkali content of the cement increased, the
effectiveness of slag decreased.
4. Replacing cement with 10% silica fume was adequate in controlling ASR
expansions.
54
0.865
0.009
0.023
0.047
0.028
0 0.2 0.4 0.6 0.8 1
Plain Concrete
10% Silica Fume
20% Silica Fume
60% Slag
70% Slag
6-Month Expansion, %
In 1996, Thomas published a report in which he included a critical review of
published work up to May of 1994. The literature review concentrated on work
completed towards better understanding of the effects of fly ash and slag on ASR
expansions. More than 400 published references were examined and evaluated.
Particular attention was concentrated on work performed by the:
1. National Building Research Institute (NBRI) in the Republic of South Africa,
2. British Cement Association (BCA),
3. Building Research Establishment (BRE) in London,
4. CSIRO in Australia,
5. The University of Texas at Austin, and
6. Concrete Society Technical Sub-Committee on AAR.
Figure 3.20: C 227 Expansion after 6 Months for Specimens Made with Different Replacement Levels (Rasheedbuzafar, 1991)
55
Class F fly ash, Class C fly ash, and slag concrete structures from around the
world were reviewed. Most of the structures with the exception of two showed
adequate performance because of the use of Class F fly ash, Class C fly ash, and slag
(Thomas, 1996).
The following conclusions and recommendations were noted:
1. ASTM C 441 is not reliable for assessing the effectiveness of fly ash and slag in
mitigating ASR.
2. The satisfactory performance of Class F fly ash, Class C fly ash, and slag
concrete structures from around the world should confirm their ability to mitigate
damaging ASR. However, there are a few exceptions in which fly ash and slag
concrete performed poorly, which emphasizes that these materials do not
guarantee a cure.
On the Use of Fly Ash (Thomas, 1996)
3. Low calcium fly ash (Class F) is not very effective with highly reactive
aggregates that are reactive with low alkali cements (less than 0.50%), such as
cristobalite and silstone. However, low-calcium fly ash is highly effective with
the less reactive aggregates such as greywacke, argillite, quartzite, etc.
4. Limiting the alkali content of the concrete will not enhance the effectiveness of
low-calcium fly ash (Class F). “The expansion in fly ash concrete appears to be
somewhat independent of the concrete alkali content in many cases.”
5. As the calcium content of the fly ash increases, its effectiveness decreases and
the proportion needed for effective mitigation increases for the same aggregate.
6. High-calcium fly ash (Class C), as well as slag, is very sensitive to the alkali
content of the concrete.
7. It is very critical to be able to classify the reactivity of an aggregate before
attempting to specify an adequate level of fly ash or slag replacement. However,
56
such an aggregate classification did not exist at the time the report was
conducted.
8. Table 3.11 includes an example of specifying fly ash for effective use. The levels
in the table are approximations.
Table 3.11: Example for Specifying Fly Ash with Reactive Aggregates (Thomas,
1996) Minimum fly ash proportion (%)
Aggregate Reactivity CaO content of ash (%)
Low
Medium
High
Max. Total alkali level
in ash (Na2Oequiv.)
Max. OPC Total alkali in
concrete kg/m3 Na2O
< 10 (Class F) 20 30 40 5.0 5.0
10 – 20 25 40 50 4.5 4.0 > 20
(Class C) 35 50 60 4.5 3.0
OPC = Original Portland Cement with No Additives
On the Use of Slag (Thomas, 1996)
9. Slag is less effective with highly reactive aggregates that are reactive with low
alkali cements (less than 0.60%).
10. As the reactivity of aggregates decreases, the effectiveness of the slag increases
with increasing level of replacement (greater than 65% replacement). At this
stage, the contribution of the alkali content of the cement is less important.
11. The contribution of the alkali content of the cement becomes more significant at
lower levels of slag (less than 50% replacement).
12. When low levels of replacement are used with highly reactive aggregates, the
alkali content of the slag becomes very critical. The higher the alkali content of
the slag the less effective it is in reducing the ASR expansions below safe limits.
13. Slag is less effective than low-calcium fly ash (Class F). Slag is also more
influenced by its alkali content and the alkali content of the cement than low-
calcium fly ash.
57
14. An example of slag specification is included in Table 3.12.
Table 3.12: Slag Specification Example (Thomas, 1996) Maximum Slag Proportion (%)
Aggregate Reactivity Defined by ASTM C 1293 Total Alkali Level in
blended cement (OPC + slag)
(% Na2Oequiv.) Low Medium High < 0.8 35 50 65
0.8 –1.5 50 60 70 > 1.5 60 70 75
Max. OPC alkali level in concrete (kg/m3 Na2Oe)
3.5 3.0 2.5
OPC = Portland Cement with No Additives
On Rapid Testing Procedures for Supplementary Cementitious Materials (SCM)
(Thomas, 1996)
15. ASTM C 441 is unsatisfactory. There is a need for developing test methods that
will accurately determine the effect of SCM in a reasonable amount of time.
16. There is an increasing interest and success with the use of ASTM C 1260
procedures. However, this test method “requires a higher level of Class C fly ash,
Class F fly ash, and slag to control deleterious expansion compared to the
standard concrete test, ASTM C 1293.”
3.3.3 Control Mechanisms of Supplementary Cementitious Materials (SCM)
The various proposed mechanisms of control can be summarized as follows (Xu
et al., 1995):
1. The pozzolanic reaction between mineral admixtures and cement hydrates results
in a decrease in the permeability of the cement paste which in turn reduces the
mobility of ions in the concrete,
2. Mineral admixtures will result in higher strength that provides higher resistance
to the expansive stresses produced by ASR,
58
3. The alkalinity of the concrete pore solution is reduced by the use of mineral
admixtures,
4. Mineral admixtures deplete Ca(OH)2 in the cement paste,
5. The pozzolanic reaction produces a secondary hydrate that entraps alkali ions in
the cement.
The chemistry of pore solution of cement pastes incorporating different amounts
of two silica fumes, three pulverized fly ash, and one ground granulated blast furnace
slag was evaluated by Ducheness and Bérubé (1994) using the high-pressure
extraction method. Examinations were performed after curing the cement pastes for
7, 28, 84, 182, 364, and 545 days at 380C and 100% relative humidity. Results of the
pore solution examinations were related and compared to expansions obtained over a
two-year period using the Concrete Prism Test, ASTM C 1293 or CAN/CSAA23.2-
14A. Concrete specimens were made with two very reactive aggregates using the
same water-cementitious materials ratio. An expansion lower than 0.04% after two
years was considered to be innocuous. It was concluded that the effectiveness of
silica fume, fly ash, and slag was attributed to their ability for decreasing the alkali
concentration in the pore solution down to a safe level. An alkali concentration of
0.65M, NaOH + KOH, over a long period of time was recommended. No significant
expansions occurred in specimens made with very reactive aggregates which had
pore solutions with alkali concentrations below 0.65N. This level was more easily
reached when the alkali contents of the cementitious materials and the concrete were
the lowest and the cementitious materials content was the highest (Duchenesse and
Bérubé, 1994).
59
3.4 FINAL REMARKS
After reviewing the selected research discussed earlier, it was clear that even
though there exist conflicting results about the effectiveness of some of the
mitigation alternatives, it is possible to mitigate ASR in concrete. The effectiveness
of an alternative depended upon the degree of reactivity of aggregates, the type of
alternative used, and the dosages used. It was also noticed that there is a lack of
specifications for the use of mitigation alternatives, which is mainly caused by the
large variety of aggregate reactivity and by the lack of accurate testing procedures
capable of predicting the degree of aggregate reactivity and determining the
effectiveness of a proposed alternative. It is possible, however, to develop guidelines
and recommendations to be used for minimizing concrete damage due to ASR. These
guidelines and recommendations need to be formulized and proven.
60
CHAPTER FOUR
REVIEW OF INTERNATIONAL EXPERIENCE WITH ASR
4.1 INTRODUCTION
An international survey was conducted in order to determine the state-of-the-art of
alkali-silica reaction worldwide. The survey concentrated on two major areas:
1. testing methods used to predict aggregate reactivity, and
2. alternatives used for mitigating the reaction.
The following is a brief summary of the survey of practices worldwide for dealing
with alkali-silica reaction in concrete.
4.2 RILEM SURVEY (Nixon And Sims, 1996)
A RILEM technical committee, RILEM TC-106 (Alkali-Aggregate Reaction),
was formed in 1988 to develop internationally approved methods for identifying the
alkali-reactivity of aggregates. The committee conducted a survey of participating
countries and was regularly updated. The following section presents the findings of
the survey.
Results from the survey, summarized in Table 4.1, indicated that there exists a
general interest in each of the petrographical, chemical, and expansion tests
categories, with the most emphasis and recognition being concentrated on the most
accelerated expansion tests methods such as ASTM C 1260. However, different
countries preferred different tests, and it was not possible to find a single test or a
series of tests that has been adopted by most countries. In addition, it was not
possible to find a “strong relationship between the reactive aggregates identified and
the methods preferred for aggregate testing and assessment.” (Nixon and Sims, 1996)
It was also found that there is an increased interest in developing test methods
capable of producing reliable results in a short period of time. Although ASTM C
61
1260 is gaining acceptance in a number of countries, several other test methods are
being developed and investigated.
It was not clear from the survey if the acceptance of a certain test method in a
country was based on the ability of a test method to predict the behavior of
aggregates in actual structures or service records. The general impression was that
test methods have been adopted from elsewhere and the interpretative criteria of the
test have been modified based on local experiences.
Table 4.1: Survey Results (published by RILEM in 1996)
Country
Petro-graphy ASTM C 295
Chemical ASTM C 289
Expansion
Mortar ASTM C 227
Expansion Concrete ASTM C 1293
Expansion Ultra-
Accel’d ASTM C 1260
Other Australia Belgium Denmark France
Germany Hong Kong
Iceland Italy Japan
Netherlands N. Zealand
Norway Romania Russia
S. Africa UK
U.S.A. = Method sometimes used or being developed = Important method
All countries, with the exception of Germany, reported that no one test is capable
of providing a comprehensive assessment of aggregates for their alkali-aggregate
62
reactivity. Germany has required that all aggregates have a satisfactory performance
when tested with specified methods established for materials in a “closely defined
geographical region.” Finally, the survey indicated that there is no test method
universally accepted for assessing the susceptibility of aggregates to the AAR.
4.2.1 Specific RILEM Survey Conclusions Related to Testing Procedures
(Nixon and Sims, 1996)
1. Petrographical examination: Petrographic examination is universally considered
adequate for identifying potentially reactive constituents in the aggregates. Most
participating countries reported that petrographic examination is used to evaluate
aggregates for ASR, and over half of the countries classified the method as being
the best. The reported range of rock types susceptible to ASR was extremely
diverse. However, there seemed to be an agreement over the range of potentially
reactive constituents such as opal, microcrystalline quartz, etc, contained in the
aggregates.
2. Chemical testing methods: Most countries performed some type of chemical test.
There appeared to be a universal adoption of the ASTM C 289 test, often with
modified interpretation procedures. No country had reported that ASTM C 289
or similar test methods are the best methods to use. This situation suggests that
results of ASTM C 289 were best used to support results from other test methods.
In France new test procedures have been standardized under “The Kinetic
Method” and the test is being evaluated internationally.
3. Expansion Methods: With the exception of Germany and Belgium, all countries
reported the use of a form of mortar or concrete expansion tests. Methods used
worldwide shared many similarities and potential differences -- mainly different
storage conditions. A universally agreed upon expansion testing method was not
apparent and a method using concrete specimens was more likely to be
acceptable universally than one using mortar bars.
63
4. Ultra-Accelerated Expansion Methods: Most replies indicated that the ultra-
accelerated expansion methods are more concerned with determining the
presence of potentially reactive constituents in the aggregates rather than being
concerned with the likelihood of expansion. Replies also indicted that this could
only be achieved with the long-term expansion methods. In addition, most replies
indicated that the long-term expansion tests are not suitable for specification
purposes. As a result, there was a universal interest in the accelerated expansion
methods that are capable of producing adequate results in less than a month. A
universally acceptable ultra-accelerated method is also desirable. The method
should be able to predict the performance of the aggregates when tested with the
long-term concrete test. In particular, ASTM C 1260 was becoming widely used.
Denmark, the Netherlands, and Norway used a slightly different version of
ASTM C 1260, and France was investigating the Chinese microbar test.
5. Other Test Methods: Several other testing procedures are being developed and
investigated; however, none have gained international acceptance. At this stage,
efforts should be spent on improving the most established procedures.
6. Overall Survey Conclusion: The overall survey conclusion was that it seems
possible to reach an international agreement on a series of tests for assessing
aggregate reactivity. For example, the following test procedures can be used in a
sequential order: first a petrographic examination should be performed, supported
sometimes by a chemical analysis. If a potentially reactive aggregate is identified
then the concrete prism expansion test should be performed. An ultra-accelerated
mortar-bar test might be used to provide an early prediction of the performance
of the concrete prisms.
4.3 ASR IN AUSTRALIA
4.3.1. Evaluating the Reactivity of Aggregates
Alkali-silica reaction has been the topic of many research studies in Australia. The
original test method used to predict Australian aggregate reactivity consisted of
64
combining appropriately graded fine aggregate with various cements to form mortar
bars measuring 25 x 25x 285 mm. The cement-to-aggregate ratio was 0.50 and
water-cement ratio was 0.40 to 0.50. Specimens were then stored at 100% R.H. in
sealed containers at a temperature of 150C. Length change was monitored
periodically every two years. This test was shown to be very slow and not practical
(Shayan, Green, and Collins; 1996).
In addition, past experience showed that the quick chemical test, ASTM C 289
(AS 1141 section 39), and the long term mortar-bar test, ASTM C 227 (AS 1141
Section 38) were inadequate for predicting the ASR reactivity of most Australian
aggregates (Shayan, Green, and Collins; 1996).
Following current trends, investigations, and recommendations, several
accelerated testing procedures were investigated at CSIRO, which included storing
concrete prisms and mortar bars in saturated NaCl solutions and in 1M NaOH at 500
and 800C. Results obtained using concrete prisms were unsatisfactory, showing
erratic expansions. Results of the mortar bars in the 1M NaOH solutions were more
consistent and more reliable. When alkalis were added to the concrete prisms, more
consistent results were obtained, but a significant reduction in the concrete strength
was noticed (Shayan, Green, and Collins; 1996).
Based on the field performance of several Australian aggregates in concrete
structures and the results of the accelerated mortar-bar test (similar to ASTM C
1260) performed on these aggregates, evaluation criteria were established as follows:
10-day expansions of 0.10% or greater identifies reactive aggregates and 21-day
expansions of 0.10% or greater identifies slowly reactive aggregates. It was noted
that this accelerated mortar-bar test was found to be more reliable than the autoclave
test. Through a series of research studies, Shayan showed that the accelerated mortar
65
bar (or ASTM C 1260) could be used to evaluate the effectiveness of fly ash and
slag in mitigating ASR expansions (Shayan 1990, 1992).
Another test that was investigated in Australia is a concrete-prism test which
consists of steam curing the prisms and subsequently storing them at 500C and 100%
R.H. Limited data have been generated using these test conditions (Shayan, Green,
and Collins; 1996).
Several aggregates with different field performances were tested using the
chemical method (ASTM C 289), the standard mortar bar (ASTM C 227), the
concrete prism (similar to ASTM C 1293), and the accelerated mortar bar (similar to
ASTM C 1260). The results are shown in Table 4.2, where it can be seen that the
concrete-prism test and the accelerated mortar bar are the most reliable test methods
(Shayan, Green, and Collins; 1996).
Describing the trend of aggregate testing for ASR in Australia, Shayan mentioned
that it is likely that “new test methods including the accelerated mortar-bar test and
the concrete-prism test (both normal and steam-cured) will be introduced. The
petrographic analysis, ASTM C 295 is likely to remain as a useful tool for the
identification of possible reactivity.” (Shayan, 1996)
66
Table 4.2: Classification of Aggregates by Different Test Methods (Shayan, 1992)
Test Method
Aggregate Service Record
Chemical C 289
Standard mortar bara
C 227
Concrete prism
Similar to C 1293
Accelerated mortar barb
C 1260 1 --- NR NR PRc R 2 --- NR NR NR NRd 3 --- R NR NR Pessimum 4 --- Borderline NR R R 5 R R Re PRc R 6 R NR NR Rf R 7 R NR NR Rf R 8 R NR NR R R 9 --- NR NR NR NR
10 --- NR NR R R 11 --- Borderline NR R R 12 --- Borderline NR R R 13 --- NR NR R R 14 --- NR R R R 15 R R R R R
aCement alkali = 1.38% Na2Oe; bBased on criteria proposed by Shayan; cDepends on the level of alkali in concrete; dExcept for one batch;eExpansion exceeded 0.10% after one year, but not six months; fat high alkali content. R = Reactive; PR = Potentially Reactive; NR = Non-Reactive.
Shayan, Ivanusec, and Diggins (1994) investigated the reactivity of five sands
with different petrographic properties but mainly slowly reactive. The investigated
testing procedures included (Shayan, Ivanusec, and Diggins; 1994):
1. Mortar-bar test at 400C and 100% R.H.: Mortar bars were made in accordance
with ASTM C 227 except that the sand was used as received without any
processing. NaOH was added to the mixing water in order to increase the alkali
content of the bars to 1.38 and 1.8% Na2Oequiv. The W/C used was between 0.30
and 0.40. Mortar bars were cured in fog for one week while being covered with a
polythene sheet. Subsequent curing consisted of storing the bars at 400C and
100% R.H.
67
2. Accelerated mortar-bar test in NaOH solutions at 800C: Mortar bars were
made in accordance with ASTM C 227 and cured in fog at 230C for three days
before starting the accelerated procedures. Subsequently, one series of specimens
was stored in each of the 0.50, 0.75, and 1M NaOH solutions at 800C.
3. Accelerated mortar-bar testing using autoclave at 1270C: Specimens, 25 mm x
25 mm x 285 mm, were made using a sand/cement/water ratio of 2:1:0.5 and
increasing the alkali content of the specimen to 2.5 and 3.5% by addition of
NaOH to the mixing water. After 24 hours of curing, specimens were demolded,
covered with a protective cover, and stored for 24 hours in a fog room at 230C.
Subsequently, specimens were autoclaved for four or five hours at 1270C.
4. Concrete-prism test: Using a non-reactive basalt coarse aggregate, concrete
prisms were made using five sands and a concrete mixture consisting of 1 part
cement, 2.62 parts aggregate, 1.55 part sand, and a w/c of 0.46. The alkali content
of the cement was increased to 1.38 and 1.8%, and the cement content of the
concrete mixtures was set at 460 kg/m3. After 24 hours of curing, concrete prisms
were demolded, covered, cured in fog at 230C for one week, wrapped in a wet
cloth and plastic sheeting, and then stored at 400C and 100% R.H.
After gathering and analyzing all the data, the following conclusions were drawn
(Shayan, Ivanusec, and Diggins; 1994):
1. Results of the mortar-bar test at 400C and 100% R.H. indicated that all five sands
are non-reactive, which contradicted the results of ASTM C 1260.
2. An expansion limit of 0.20% at 14 days for the mortar bars stored in 1M NaOH
at 800C (ASTM C 1260) resulted in all aggregates being non-reactive and was
viewed as not effective. An expansion limit of 0.10% was found more effective.
3. ASTM C 1260 expansions of all sands exceeded 0.10% at ages 10 to 17 days but
were lower than 0.20%.
68
4. When evaluated using the proposed expansion limits for non-reactive aggregate
of 0.15, 0.33, and 0.48% at ages of 14, 28, and 56 days, respectively (Rogers,
1993), only one aggregate out of five was classified as reactive. These limits
were found to be not effective in identifying a number of known slowly reactive
aggregates (Shayan et. al., 1988).
5. Four out of the five aggregates were classified as slowly reactive using the
expansion results of the mortar bars stored in 0.75M NaOH at 800C.
6. Expansions of mortar bars in 0.50N NaOH at 800C classified all five aggregates
as non-reactive.
7. The testing conditions of the concrete-prism test did not result in considerable
expansions for all the sands but one and that was after 40 weeks of storage.
8. The autoclave testing procedures resulted in a non-reactive classification of the
aggregates except for one sand.
9. The autoclave test, with 3.5% alkali content mortar bar autoclaved at 1270C for 4
or 5 hours, were not suitable for detecting slowly reactive aggregates.
10. The ASTM C 1260 procedures were effective in predicting the potential alkali
reactivity of slowly reactive aggregates which showed 10- to 17-day expansions
between 0.10% and 0.20%; however, the relevance of this method to field
concrete needs to be determined
4.3.2. ASR Preventive Measures
Shayan, Diggins, and Ivanusec (1996) conducted a long-term, six-year study in
order to determine the effects of fly ash on ASR. They tested one innocuous
aggregate and six reactive aggregates. Two types of fly ashes with varying total
alkali content (0.01 and 6.30% Na2Oequiv.) and two types of cements were used. The
alkali content of the concrete was varied by adding NaOH to the mixing water.
Concrete specimens were formed and stored in a fog room at either 230C or 400C at
100% relative humidity. Expansions were monitored for nearly six years and several
69
mortar tests were performed. The results were as follows (Shayan, Diggins, and
Ivanusec; 1996):
1. The fly ashes tested were effective in preventing deleterious ASR expansions
when used in concretes with alkali contents as high as 7.0 kg Na2Oequivalent per m3
(1.4% Na2Oequivalent cement content); however, they only delayed damage in
concretes with alkali contents around 12 kg Na2Oequivalent per m3 (2.5%
Na2Oequivalent cement content). These alkali levels are outside the usual range of
concrete alkali levels in the field that vary between 0.60% to 1.20% Na2Oequivalent
cement content.
2. Long-term monitoring of concrete specimens is necessary to evaluate the
effectiveness of fly ash in reducing ASR damage.
3. The alkalinity of the pore solution of mortar cylinders was reduced significantly
by the use of fly ash. The reduction occurred faster for specimens stored at 400C
than those stored at 230C.
4. The accelerated mortar-bar test (ASTM C 1260) can be used to predict the long-
term effectiveness of fly ash in controlling ASR expansion in concretes having an
alkali contents resulting in pore solutions having approximately 1M NaOH
concentrations which corresponds to concrete specimens at 1.38% alkali levels.
4.4 ASR IN CHINA
Alkali-silica reactive aggregates exist in China. Portland cements with an alkali
content as high as 1.20% Na2Oequiv. are used in China. In addition, chemical
admixtures are widely used to improve workability, strength, or other properties.
These admixtures usually add about 0.30-1.30 kg/m3 Na2Oequiv. to the total alkali
content of concrete. In general, in North China, there are “absences of low alkali
portland cements and non-reactive aggregates (Tang et al., 1996).”
70
4.4.1. Evaluating the Reactivity of Aggregates (Tang et al., 1996)
Testing procedures used to evaluate aggregates’ reactivity include ASTM C 295,
C 227, C 289, and an accelerated autoclave method proposed by Tang et al.,1996.
The autoclave method is most widely used by engineers and researchers (Tang et al.,
1996).
4.4.2. Preventive Measures
In order to minimize the risk of deterioration due to ASR, the maximum alkali
contents of concrete listed in Table 4.3 were proposed (Tang et al., 1996).
Table 4.3: Maximum Alkali Content (Tang et al., 1996)
Maximum alkali content (kg/m3) in concrete Conditions of Circumstances Ordinary Structure Important Structure Special Structure
Dry No limit No limit 3.0 Wet 3.5 3.0 2.1
With alkali 3.0* Non-reactive aggregate Non-reactive aggregate * The structures should be effectively painted, otherwise non-reactive aggregates should be used
4.4.3. ASR in Beijing
The alkali-silica reaction in concrete is a concern to the Beijing area. As the
concrete structures become older, more damage due to ASR is expected to be
identified (Peixing et al., 1996). After conducting extensive field surveys and
laboratory testing, it was concluded that most sands available in the Beijing area are
non-reactive (only a few samples were found to be reactive) while several coarse
aggregates were found to be responsible for most of the alkali-silica reaction
problems.
Testing procedures used in Beijing included ASTM C 227, C 1260, C 289, and an
autoclave method. Preventive measures practiced included (Peixing et al., 1996):
71
Routinely evaluating the reactivity of aggregates used in important concrete
structures using the above listed tests.
1. Limiting the total alkali content in concrete to 3 kg/m3.
2. Using low-alkali mineral admixtures.
4.5. ASR IN CANADA
In Canada the alkali-silica reaction has been divided into two groups (CSA,
1994):
1. Alkali-silica reaction with chalcedony, opal, cristobalite, glass, etc., which can be
usually identified using ASTM C 227. Concrete prisms expansion tests at 380C
using high cement content and high alkali content cement (ASTM C 1293) can
also be used to evaluate this type of reaction. ASTM C 289 can also be used;
however, this test might give misleading results when carbonates are present
(Rogers, 1993).
2. Slow alkali-silica reaction associated with sandstones, granites containing
strained quartz, and metamorphosed sediments such as phyllite, argillite, and
greywacke. Conventional testing procedures such as ASTM C 227 and C 289 are
not suitable for evaluating this type of reaction. ASTM C 1293 is more
adequately used to identify these slow reactions (Rogers, 1993).
4.5.1 Evaluating the Reactivity of Aggregates
A large number of research studies have been completed in Canada for the
purpose of identifying and developing the ideal testing procedures for assessing
aggregates reactivity. The following is just a review of selective work conducted in
Canada.
4.5.1.1. “Testing Concrete for AAR in NaOH and NaCl Solutions at 380C and
800C (Berube and Frenette, 1994).
72
In order to minimize the effects of storage conditions used with CSA A23.2-14A
(ASTM C 1293) and to accelerate the procedures, concrete prisms were tested in
NaCl and NaOH solutions at different temperatures. Two very reactive Canadian
aggregates were used: 1) a very fine-grained rhyolitic tuff and 2) a fine-grained
siliceous limestone. Non-reactive sand satisfying the requirements of ASTM C 1260
was used for mixture proportioning. Two types of cements were also used: one
having a high alkali content of 0.85% Na2Oequiv. and the other having an alkali
content of 0.54%. Concrete prisms, 75 mm x 75 mm x 300 mm, were made using the
two reactive aggregates in combination with the non-reactive sand. The concrete
mixtures had a water-cement ratio of 0.55 and incorporated 310 kg/m3 of the high
alkali content cement. NaOH was added to the mixing water in order to increase the
alkali content of the cement mass to 1.25% Na2Oequiv. (equivalent to a concrete alkali
content of 3.9 kg of Na2O/m3). Several concrete specimens were made using the low
alkali content cement in order to determine the effect of the initial alkali content of
the cement on the expansions. These specimens had a total alkali content of 1.7
kg/m3. After fabrication, concrete prisms were stored, while still in molds, for 24
hours at 100% R.H. and 230C. Prisms were then demolded and cured for another 24
hours under the same conditions. Two concrete prisms were stored under each of the
following conditions (Berube and Frenette, 1994):
1. Tests in air at 100% RH and 380C: After curing was completed, concrete
specimens were immersed in water for 30 min., measured for the zero reading,
and then stored over water in sealed 22-liter plastic pails, with wicking, at 380C.
Before taking scheduled expansion readings, the sealed containers were stored
for sixteen hours at 230C after which the specimens were immersed in water for
30 minutes and then measured for expansion.
2. Tests in air at 100% RH and 800C: Specimens were stored over water in sealed
8-liter Rubbermaidcontainers (two specimens per container) in an oven at 800C.
73
The initial reading (zero reading) was taken after one day. All expansion
measurements were taken while specimens were still hot, as soon as they were
taken out of the oven.
3. Immersion tests in 1M NaCl solution at 38 or 800C: After curing, specimens
were immersed, in groups of two, in 1M NaCl solution (6% NaCl by mass), in
sealed 8-liter Rubbermaid containers. Each container had 4.4 liters of solution,
for a volumetric solution/concrete ratio of 1.3 (1 prism = 1.7 liter). The
containers were then immediately stored in an oven at 800C or in a temperature-
controlled room at 380C. The zero reading was recorded the following day.
Expansion measurements were taken while specimens were still hot, as soon as
they were taken out of the oven or the temperature-controlled room.
4. Immersion tests in 1M NaOH solution at 38 or 800C: The same procedures as
for immersion tests in 1M NaCl solution at 38 or 800C were used.
5. Immersion tests in water at 38 or 800C: The same procedures as for immersion
tests in 1M NaCl solution at 38 or 800C were used.
The following conclusions and recommendations were documented (Berube and
Frenette, 1994):
1. A relatively rapid ion migration exists, by diffusion, between the immersion
solution and the concrete pore solution.
2. Testing in 1M NaCl solution is not appropriate.
3. Testing in water resulted in a dilution of the alkalis in the pore solution of the
specimens and gave very low expansion results.
4. The initial concrete alkali content affected the rate of expansion of specimens
immersed in 1M NaOH solutions. Increasing the concrete alkali content to 1.25%
Na2Oequiv. of the cement mass was recommended.
5. While testing in 1M NaOH at 800C proved to be the most rapid concrete test
74
method, it was also proven that it is unreliable for determining the potential
alkali-reactivity of numerous aggregates.
6. The best concrete test method used 1M NaOH at 380C based on the following
reasons: a) it gave expansion results that are either similar or greater than the
results of the 100% RH test but in a significantly shorter term (about 6 months),
b) there was no alkali leaching from the concrete specimens, c) there was no
variation in the humidity conditions during one test and from one laboratory to
another, and d) since the chemistry of the concrete pore solution is controlled by
the curing solution, the effects of the water-cement ratio were minimized.
7. The recommended testing method to use for the evaluation of the potential alkali
reactivity of aggregate is the immersion of concrete prisms in 1M NaOH at 380C.
Prisms were made using a cement content of 310 kg/m3 and a water-cement ratio
between 0.50 and 0.55. The proposed criterion for identifying reactive aggregates
was 0.040% expansion or larger at 6 months.
4.5.1.2. “Effectiveness of High-Volume Fly Ash Concrete in Controlling
Expansion Due to Alkali-Silica Reaction (Fournier, Bilodeau, and Malhotra;
1994).
This study consisted of testing two alkali-silica reactive Canadian aggregates,
siliceous limestone (Sp) and metagreywacke (Con), in combination with a local non-
reactive fine aggregate from granite. Properties of the aggregates are included in
Table 4.4.
The two reactive aggregates were tested for ASR in concrete mixtures containing
high- and low-alkali Type I portland cements and incorporating 56% of six selected
Canadian fly ashes. All high-volume fly ash mixtures had a nominal cementitious
materials content of 375 ± 10 kg/m3and water-to-cementitious materials ratio of
0.31 ± 0.01.
75
Table 4.4: Properties of Aggregates Investigated (Fournier, Bilodeau, and Malhotra; 1994)
Expansion ASTM C 1260, %
Aggregates ID
Location
Type
Rock Type
Realtive Density (SSD), g/cm3
Absorption,
%
14 day
28 day
Sp
Ottawa
Quarried
Rock
Siliceous limestone and traces of chert
2.69
0.48
0.356
0.625
Con
Halifax
Quarried
Rock
Greywacke
2.71
0.80
0.362
0.590
Fine
Aggregate
Cantley
Natural Sand
Derived
from granite
2.70
0.81
0.032
0.085
Concrete prisms, 75 mm by 75 mm by 300 mm, were made using variable
proportions and subjected to the following conditions:
1. 380C and relative humidity greater than 95%. Prisms were wrapped individually
in two damp sheets, placed in a plastic sleeve, and then placed vertically over
water inside a 25-L plastic pail with wicking materials on the sides.
2. 1M NaOH solution at 380C
3. 5% NaCl solution at 380C
4. 1M NaOH solution at 800C
Prisms subjected to conditions 2, 3 and 4 were stored in large polyethelene tubes
containing 24 prisms and the appropriate solution. The tubes were then placed in a
large tank filled with water and constantly maintained at the needed temperature.
Mortar bars were formed and tested according to ASTM C 1260.
76
The results of that study were as follows (Fournier, Bilodeau, and Malhotra; 1994):
1. After evaluating the results and comparing expansions from the different storage
conditions investigated during this study, the following expansion limits in Table 4.5
were suggested.
Table 4.5: Proposed Limits for Different Testing Conditions (Fournier, Bilodeau, and Malhotra; 1994)
Storage/Testing Condition
Proposed Expansion Limit
380C and R.H. > 95%: (Concrete Prisms)
0.04% at 52 weeks (CSA proposed limit) 0.04% at 104 weeks (mixtures with fly ash)
380C in 1M NaOH Solution: (Concrete Prisms)
0.04% at 26 weeks (control mixtures) 0.04% at 52 weeks (mixtures with fly ash)
380C in 5% NaCl solution: (Concrete Prisms)
Not Recommended (control mixtures) Not Recommended (mixtures with fly ash)
800C in 1M NaOH solution: (Concrete Prisms)
0.04% at 4 weeks (control mixtures) 0.04% at 8 weeks (mixtures with fly ash
800C in 1M NaOH solution: (Mortar Bars)
0.15% at 14 days (CSA proposed limit) 0.10% at 14 days (mixtures with fly ash)
1. Using the above expansion limits, it was possible to reliably evaluate the
potential alkali-reactivity of the tested reactive aggregates. The accelerated
concrete tests represented substantial acceleration compared to the proposed
standards.
2. The accelerated mortar-bar test, ASTM C 1260, was successful in predicting the
effectiveness of the high volume fly ash replacement in controlling expansions
due to ASR. All the results generated using this accelerated mortar-bar test
correlated very well to expansion results obtained from the different concrete
prisms testing conditions.
77
3. In concretes incorporating high volumes of fly ash, control of the expansions
due to ASR is dependent upon the chemical composition of the fly ash, in
particular its calcium and alkali content.
4.5.1.3. Inter-laboratory Test Evaluation
4.5.1.3. 1.ASTM C 1260 Rogers (1996) reported a study with a purpose of developing a multi-laboratory
precision statement for the accelerated mortar-bar test (ASTM C 1260). A Spratt
siliceous limestone from a quarry in Ottawa (Ontario) was tested by 46 laboratories.
It was found that the coefficient of variation in the 14-day expansion was 13.3%
when all laboratories used the same cement and 14.9% when each laboratory used a
different cement. Precision was stated as follows: “For mortars giving average
expansions after 14 days in solution of more than 0.30%, the muti-laboratory
coefficient of variation has been found to be 14.9%. Therefore, the results of two
properly conducted tests in different laboratories on specimens of a sample of
aggregate should not differ by more than 42% of the mean expansion (Rogers,
1996).”
The CSA version of the test requires the use of a cement with a total alkali content
of 0.90 ± 0.10%. The ASTM version requires the use of a cement with an autoclave
expansion of less than 0.20%. The new recommended specification should be to use
any type of cement provided that when combined with the Spratt aggregate tested in
this study, it can produce 14-day expansions between 0.329% and 0.504% (Rogers,
1996).
4.5.1.3.2. ASTM C 1293 Fournier and Malhotra conducted a study in order to determine the inter-
laboratory variation of the concrete-prism test. The study consisted of testing two
reactive aggregates in combination with three non-reactive sands and Type 1
cements. The mixture designs were changed as well as the storage conditions of the
78
concrete prisms. A total of 27 laboratories, 24 from Canada, one from the U.S.A,
and two from France participated in the study. It was concluded that the between-
laboratory variability could be greatly reduced by using well-controlled testing
conditions or parameters such as “ a reference sand, a reference cement, a standard
storage container, and fixed concrete mixture proportioning.” It was also found that
the between-laboratory standard deviation and the coefficient of deviation of the test
prisms stored in 1M NaOH solution at 380C was significantly lower than the
coefficients of prisms under other storage conditions which included over water at
380C and 95% R.H (Fournier and Malhotra 1996).
4.5.2. ASR Preventive Measures
Thomas, Hooton, and Rogers (1997) outlined the guidelines recommended by the
Canadian Standards Association (CSA 1994) for preventing damage due to AAR in
new concrete construction. In order to minimize the risk of ASR in concrete, 1)
aggregates can be selected based on documented field performance, petrographic
examination, or satisfactory performance in a sequence of accelerated and long-term
expansion tests, namely, ASTM C 1260 (CSA A23.2-25A) and ASTM C 1293 (CSA
A23.2-14A) or 2) preventive measures can be adopted.
4.5.2.1. Field Performance (CSA, 1994)
The best method for determining whether an aggregate is potentially reactive is to
examine the history of its field performance. An aggregate can be used in concrete
without any additional precautions providing that satisfactory field performance can
be demonstrated as follows (CSA, 1994):
1. The cement content and the alkali content of the cement should be the same or
higher in the field concrete as is proposed in the new structure.
2. The concrete examined should be at least 10 years old.
3. The exposure conditions of the field concrete should be at least as severe as those
in the proposed structure.
79
4. A petrographic study should be conducted to demonstrate that the aggregate in
the structure is similar to that under investigation in the absence of conclusive
documentation.
5. The possibility of supplementary cementing materials having been used should
be considered.
6. The water-cement ratio of the concrete may affect performance.
4.5.2.2. Laboratory Studies (CSA, 1994)
The laboratory testing procedures recommended by the CSA are listed in the
following Table 4.6. Figure 4.1 shows a flow chart that was proposed by Berube
(1992) for using these three testing procedures.
Table 4.6: Recommended Procedures and Limits to Detect Alkali-Reactive Aggregates (Berube, 1992).
Designation
Name and Description
Recommended Limits
ASTM C 295
Petrographic examination of aggregates for concrete
No limits but regarded as essential in interpreting results of other observations
CSA A23.2-25A (ASTM C 1260)
“Detection of alkali-silica reactive aggregate by accelerated expansion of mortar bars.” Mortar bars stored in NaOH solution at 800C. Can be used for coarse and fine aggregate.
Maximum of 0.15% at 14 days in solution (0.10% for some siliceous limestones, granites, gneisses, and some sandstones). Aggregate may still be used if it meets CSA A23.2-14A.
CSA A23.2-14A (ASTM C 1293)
“Potential expansivity of aggregates (length change of concrete prisms).” Concrete is made with cement content of 420 kg/m3 and 1.25% alkalis, stored at 38oC. Can be used for testing coarse or fine aggregate.
Maximum of 0.04% at 1 year, less than this (no value given) for critical structures such as dams and nuclear containment where small strains can cause excessive damage.
80
4.5.2.3. Preventive Measures (CSA, 1994)
If an aggregate is classified as non-reactive using the above procedures then it can
be used in concrete without additional precautions. On the other hand, potentially
alkali-silica reactive aggregates should be used with appropriate preventive
measures. Recommended measures include:
1. Limiting the total alkali content of the concrete including alkalis from portland
cement and other sources to 3.0 kg/m3 Na2Oequivalent. Reducing the alkali content of
the concrete may be achieved by reducing the cement content, using a low-alkali
content cement, or replacing part of the cement with a supplementary cementitious
material.
1. Using supplementary cementitious materials such as fly ash with a minimum
replacement level between 20 and 30% depending on composition or slag with a
minimum replacement level of 50%. Effectiveness of these materials with
specific cements should be checked using the long-term concrete-prism test. The
total alkali content of the slag is limited to 1.0% while that of fly ash is limited to
4.5% Na2Oequiv. If these criteria are met, the contribution of the slag and fly ash to
the total alkali content of the concrete is considered to be zero.
2. Using silica fume, which is another potential cementitious material for reducing
the damage caused by potentially reactive aggregates. However, there is no
guidance for its use with reactive aggregates. Additional investigations are
needed to determine the ideal use of silica fume for controlling ASR damage.
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4.6 ASR IN DENMARK (Chatterji et al., 1992)
Most of the aggregate sources available in Denmark contain some form of
reactive components. “There is always a risk of ASR (Chatterji et al., 1992).” As a
result, Denmark is very active and very strict in providing specifications for
preventing ASR damage in concrete. The following is a description of the practices
used to address ASR:
Figure 4.1: Decision Chart for Determining Potential ASR Reactivity of Concrete Aggregates (Berube, 1992).
82
There are three parameters used to minimize the risk of ASR in concrete:
1. Alkali content of the concrete
2. Reactivity of the aggregate
3. Environmental conditions
4.6.1 Alkali Content of the Concrete
The alkali content of the cement is added to alkalis from other sources such as
mineral and chemical admixtures used as mixture components to determine under
which group the cement falls. Table 4.7 includes the different cement groups. “The
assumption of a constant and uniform distribution of alkali in a concrete structure has
been dropped” (Chatterji et al., 1992).
Table 4.7: Alkali Content Groups (Chatterji et al., 1992) Group Label Description Details
EA Extra low Alkali ≤ 0.4% Na2Oequiv..
LA Low Alkali ≤ 0.6% Na2Oequiv..
MA Medium Alkali ≤ 0.8% Na2Oequiv..
HA High Alkali ≤ 0.4% Na2Oequiv..
4.6.2 Environmental Classification
Three environmental classes are defined as follows:
1. Aggressive Environmental Class: Includes concrete exposed to salt, flue gases,
seawater, or brackish water.
2. Moderate Environmental Class: Includes concrete exposed to moisture, non-
aggressive outdoor and indoor environment, and flowing or standing fresh water.
3. Passive Environmental Class: Includes concrete exposed to dry and non-
aggressive environment (particularly indoor climate).
4.6.3. Aggregate Specification
Aggregates are classified into three different categories:
1. Class P: Used in passive environments
83
2. Class M: Used in moderate environments
3. Class A: Used in aggressive environments
Sands are classified using thin-section point-count method or the mortar-bar
expansion test in saturated sodium chloride solution. Example of such a classification
is included in Table 4.8.
Table 4.8: Sand Classification (Chatterji et al., 1992) Class P Class M Class A
Volume of reactive Flint (%) No Demand Max. 2.00% Max. 2.00% Mortar bar expansion at 8 weeks No Demand Max 0.10% Max. 0.10%
Coarse aggregates are limited by their content of reactive components and the
absorption of the flint with density larger than 2400 kg/m3. Table 4.9 is an example.
Table 4.9: Coarse Aggregate Classification (Chatterji et al., 1992) Class P Class M Class A
Particles with density less than 2400 kg/m3 No Demand Max. 5.0% Max. 1.0% Absorption No Demand Max. 2.5% Max. 1.1%
4.6.4 Concrete Specifications
The Danish code of practice called “BBB (Basis Betonbeskrivelsen for
Byningskonstruktioner)” requires that concrete used in all public building
construction should be proportioned as a function of all the above factors and as
detailed in Table 4.10.
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Table 4.10: Specifications for Concrete (Chatterji et al., 1992)
4.7 ASR IN FRANCE
4.7.1. Evaluating the Reactivity of Aggregates
Available French draft methods can be divided into three categories: 1) long-term,
mortar and concrete, accelerated expansion tests at 380C (P 18-585 mortar and P 18-
587 concrete), 2) ultra-accelerated expansion methods using mortar bars (P 18-588
and P 18-590), and 3) chemical methods (P 18-589) (Criaux et al., 1994).
85
The long-term expansion test performed on mortar specimens (P 18-585) applies
to natural sands only. Sands containing high quantities of chert (potentially reactive
with a pessimum effect (PRP) aggregates) are not identified using these procedures.
The test is similar to ASTM C 227 with the following exceptions (Criaux et al.,
1994):
1. Test is only applicable to sand.
2. Sands are used as received and are not processed.
3. The alkali content of the cement is increased to 1.25% Na2Oequiv.
4. The mortar bars are stored in double containers maintaining 100% humidity at
380C.
5. The proposed expansion limit is 0.10% at 6 months.
The long-term concrete-prism test is similar to ASTM C1293, where the cement
alkali content is increased to 1.25% Na2Oequiv. and the cement dosage is 410 kg/m3.
Concrete prisms are formed using the coarse aggregate in combination with a pure
limestone sand. Prisms are stored at 380C and 100% RH. The proposed limit is
0.04% after 8 months of periodic expansion monitoring. It was concluded that this
test is not recommended for coarse aggregates containing more than 50% chert
(Criaux et al., 1996).
The microbar test (P 18-588) consists of grinding and sieving the sand or gravel
samples to the 160 to 630 µm fraction. Small mortar bars are cast using cement-
aggregate (c/a) ratios of 2, 3, and 10. The alkali content of the bars is increased to
1.5% of Na2Oequiv.. The bars are first cured for four hours at 100% R.H. and 1000C
and then submerged in a 10% KOH solution at 1500C for 6 hours. For each cement-
to-aggregate ratio (c/a), the final expansion is measured. The highest expansion
among the different c/a rations is compared to the threshold of 0.11%. Except for
86
chert-rich aggregates, expansion decreases with increasing c/a ratio. The plot of
expansion versus the c/a ratio shows the distinction between potentially reactive
aggregates and aggregates potentially reactive with a pessimum (Criaux et al., 1996).
The kinetic test (P 18-589) consists of reducing the sand or gravel to the 0 to 300
µm fraction and subjecting it to a chemical attack by a 1M NaOH solution at 800C.
The SiO2 and Na2O concentrations in the solution are determined after 24, 48, and 72
hours. The values of SiO2/Na2O are plotted on a graph resulting in three reactivity
domains, non-reactive (NR), potentially reactive (PR), and potentially reactive with a
pessimum (PRP). This test method is not recommended for identifying the potential
reactivity of dolomitic limestones. It is, however, suitable for distinguishing between
PR and PRP aggregates (Criaux et al., 1994).
The first step in conducting the autoclave test (P 18-590) is to prepare the
aggregates in accordance with ASTM C 227. The alkali content of the mixtures is
increased to 4.0% Na2O. The mortar bars are first pre-cured in water for 24 hours and
then subjected to a five-hour autoclave treatment at 1270C and 0.15 MPa. The
proposed expansion limit is 0.15% (Criaux et al., 1994).
According to the requirements of AFNOR P 18-542, the limits of the different
testing methods must be met to within ±10% uncertainty zone.
After testing nine sands and 20 coarse aggregates of various petrographic types
using all five testing procedures, it was concluded that there was good agreement
between the various test methods and between the tests and petrographic evaluation
of the aggregates. One exception was with the long-term mortar and concrete tests
used to evaluate chert-rich aggregates. Three types of aggregates were distinguished:
non-reactive (NR), potentially reactive (PR), and potentially reactive with pessimum
87
effect (PRP) with the latest (PRP) representing aggregates with more than 60%
chert. The following Table 4.11 includes some conclusions specific to each
investigated testing methods (Criaux et al., 1994).
4.7.2. Preventive Measures (Le Roux et al., 1996)
According to LeRoux et al. (1996) factors affecting the process of reducing the
risk of damage due to AAR include:
1. Alkali content of the concrete
2. Type of aggregates
3. Type of cement
4. Environmental conditions
5. Acceptable level of risk
88
Table 4.11: Summary of the Different AFNOR Testing Procedures (Le Roux et al., 1996)
AFNOR Method
Testing Method
Na2Oeq
uiv. by weight
of cement
Dimensions of Specimens
(cm)
Materials Tested
Proposed Limits and diagnosis
P 18-585 Mortar-bar test (modified C 227)
Expansion test on mortar at 380C and 100% R.H.
1.25%
2.5x2.5x28
Sand only
0.10% at 6 months PR or NR
P 18-587 concrete-prism test (C 1293)
Expansion test on concrete prisms at 380C and 100% R.H.
1.25%
7x7x28
Gravel only
with NR sand
0.04% at 8 months PR or NR
P 18-588 Microbar test
Expansion test on mortar bars at 3 cement/aggregate ratios; pre-cure at 1000C, 100% R.H. (4h); cure at 1500C in KOH 10% (6h)
1.50%
1x1x4
Sand or coarse
aggregates
0.11% and curve of expansion vs. C/a PR, PRP, or NR
P 18-589 Kinetic test
Chemical and kinetic test at 800C in 1M NaOH; SiO2/Na2O measured at 24, 48, and 72 h.
Not applicable
Sand or coarse
aggregate
3 zones on a graph
P 18-590 Autoclave test
Expansion test on mortar bars; pre-cure in water (24 h); cure at 1270C, 0.15 MPa, in autoclave (18 h).
4.0%
4x4x16
Sand or coarse
aggregate
0.15% PR or NR
Petrography
Binocular, optical microscopy on thin sections, point counting, scanning electron microscope, chemical analysis, XRD
Sand or coarse
aggregate
Presence of reactive silica NR or PR
The following sections include a summary of the French code of practice
regarding ASR.
89
4.7.2.1. Alkali Content of the Concrete (Le Roux et al., 1996)
The threshold alkali content recommended by the French Ministry of Equipment
and Transportation is 3.0 kg/m3 of concrete.
4.7.2.2. Acceptable Level Of Risk And Environment Conditions (Le Roux et al.,
1996)
The following Table 4.12 categorizes structures according to their environment
and characterization (location, strategic and economic importance, size, purpose,
etc.). “The Employer is responsible for the decision as to which category the
structure belongs to.” (Le Roux et al.,1996)
Table 4.12: Level of Prevention as Determined by the Category and Exposure of the Structure (Le Roux et al.,1996)
Environment Class Category of Structure
1 dry or not very damp
2 damp to
wet
3 damp with
frost and de-icing salts
4 maritime
environment
I Slight risk Acceptable A A A A II Risk not very acceptable A B B B III Risk Unacceptable C C C C
The following are definitions of the different levels (Le Roux et al.,1996):
Level A: No special precautions with respect to the alkali-aggregate reaction are
necessary. The only requirements are the usual rules of construction.
Level B: In this case, which is the most common (it applies to most civil engineering
works), there are theoretically six possibilities allowing the use of potentially
reactive aggregates. They allow the use of aggregates of all types satisfying the
conditions of one of the possibilities for eliminating risk.
90
Level C: In this case, non-reactive aggregates (NR), or else aggregates characterized
as potentially reactive with pessimum effect (PRP), may be used in the concrete.
Methodology used for Level B prevention is summarized in Table 4.13.
Table 4.13: Methodology Used for Level B Prevention (Le Roux et al., 1996)
Question 1 Question 2 Question 3 Question 4 Question 5 Question 6 Does the quarry documentation show that the aggregates are non-reactive?
Does the formulation satisfy an analytical criterion (assessment of alkalis)?
Does the formulation satisfy a performance criterion (swelling test)?
Is the formulation accompanied by sufficiently convincing references of use?
Does the concrete contain mineral addition in sufficient proportions?
Are the conditions specific to PRP aggregates met?
Questions 1 and 4 are based on statistical data that the aggregate producer should
supply.
Question 2 is concerned with the determination of the active alkalis contained in
a sample of cement, Tm, which should not exceed the specified threshold of 3.0
kg/m3.
Formulation of Planned Concrete
The concrete formulation is accepted
The concrete formulation must be modified
Yes to one of the questions
No to all of the questions
91
VcTm
215.3
+< (Eq 4.1)
Where “Vc is the ratio of the standard deviation to the mean of the active alkali
content values observed over the last twelve months’ output.” The active alkali
content of the aggregates is determined by submerging the aggregates in boiling
lime water and measuring the dissolved alkalis after seven hours. The active
alkalis of blended cements are determined using either of two methods:
1. Using a formula: If the proportions of the various components of the cement
are known, then the active alkalis are obtained by adding “together the alkalis
from the individual constituents in proportion to the contents of each in the
cement and weighting the alkalis by an activity coefficient determined by the
type of constituent. The coefficients used are 0.5 for slags and calcareous
fines; 0.17 for fly ash and pozzolans; and 1.0 for clinker and gypsum.”
2. Using an experimental method: By attacking the blended cement with a weak
acid (HNO3 1:50), it is possible to determine the soluble alkali content (As)
and the insoluble residue content (R). The active alkali content (A) is then
determined by the formula:
AsR
RJJAsAtA−
−+−+−=
1)(5.0)1()(17.0 (Eq 4.2)
where
At = total alkali content of the cement
J = content of the constituents other than clinker (slag, ash, pozzolans, etc.)
Question 3 calls for using an accelerated test method to check that the concrete
mixture proposed will not exhibit deleterious ASR. The measured expansions
during this test should be less than the maximum allowed expansions. The testing
92
procedure to be used is P 18-587 (Table 4.11), but the temperature should be
increased to 600C. The maximum allowable expansion is 0.02% at 3 months if
the following aggregates are used:
1. Massive Rocks: sandstones, limestones, quartzites
2. Alluvial Deposits: Silico-calcareous alluvia, calcareous alluvia, flints,
siliceous concretions, cherts.
For all other types of rocks, the maximum allowable expansion is 0.02% at five
months. Exactly the same concrete mixture proposed for use in the structure
should be used for fabricating the testing specimens. However, in order to
account for the variability of the alkali content in the field concrete, the alkali
content of test specimens should be adjusted by adding NaOH without changing
the water-cement ratio. The quantity of NaOH to be added (δ) should be
calculated as follows (Le Roux et al., 1996):
])21([ AechVcAmC −+=δ kg/m3 (Eq 4.3)
where
C = cement content in kg/m3
Am = mean active alkali content of cement
Vc = coefficient of variation of the alkali content of the cement
Aech = active alkali content of the sample of cement in the specimens
If Am and Vc are not available than the following equation should be used:
AechC ××= 25.0δ (Eq 4.4)
93
1.29δ kg/m3 of NaOH should be added. If δ is negative, then no additional NaOH is
required.
Question 6 deals with flint aggregates which usually are potentially reactive with
pessimum effect (PRP). These aggregates can be used for a Level C structure.
The following conditions have to be met in order for the aggregate to be
acceptable for use:
Condition 1:
-- Either the concrete contains only PRP aggregates (PRP sand, PRP
gravel);
-- The mixture, composed of aggregates separately classified as NR, PR, or
PRP, is characterized as PRP. The mixture has to be checked using either
NF P 18-588 or NF P 18-589 (Table 4.11).
Condition 2:
-- Using the counting procedures, the granular mix is found to contain more
than 60% flint by mass;
-- Or the 8-month expansion of specimens made with the proposed
aggregates, is less than 0.04% when tested with the procedures of the
modified NF P 18-587 (Table 4.11).
The flow chart shown in Figure 4.2 represents the procedures followed for
assessing the reactivity of aggregates. This approach was evaluated by applying it to
different aggregates used in existing very old deteriorated structures.
94
4.8 ASR IN THE NETHERLANDS
According to Heijnen et al. (1996), the number of the structures affected by ASR
in the Netherlands has increased from three to 35 from 1991 to 1996. Most of these
structures were between 30 and 60 years old, which suggested that the rate of ASR in
Figure 4.2: Flowchart of Testing Procedures Used to Evaluate Aggregate Reactivity (Le Roux et al., 1996)
95
this country is relatively slow. This was attributed to “the nature of the reactive
components (coarse porous chert grains) of the aggregates, the relatively low content
of potentially reactive aggregate particles, the generally low cement content of Dutch
concrete, and the generally low alkali content of Dutch portland cement (Heijnen et
al.,1996).” Two concrete structures incorporating low amounts of slag (about 40% by
mass of cement) were identified as being damaged due to ASR.
4.8.1. Evaluating the Reactivity of Aggregates
In the Netherlands, petrographic examination is the major test used for identifying
the susceptibility of aggregates to ASR. Petrographic examination, in combination
with PFM and point-counting analysis, are used on a routine basis. Concrete
aggregates are separated based upon their mineralogical composition (Heijnen et al.,
1996):
1. Aggregates with such a low amount of reactive components that no harmful ASR
can occur, indicated as “under critical,”
2. Aggregates with such a high amount of reactive components that no harmful
ASR can occur, indicated as “above critical,”
3. Aggregates with an amount of reactive components that harmful ASR can occur,
indicated as “critical.”
4.8.2. Preventive Measures
In the Netherlands, determining the potential ASR reactivity of aggregates is of
minor importance, since“concrete mix design and cement type can be chosen in such
a way that the risk of harmful ASR is negligible (Heijnen et al., 1996).” More than
70% of all concrete produced in the Netherlands incorporate one of the following
cements, which are assumed to prevent damage due to ASR (Heijnen et al., 1996):
1. Portland blast furnace slag cement with more than 65% (by mass) slag and an
96
alkali content less than 2.0% (by mass)
2. Portland blast furnace slag cement with more than 50% (by mass) slag and an
alkali content less than 1.1% (by mass)
3. Portland fly ash cement with more than 25% (by mass) fly ash and an alkali
content less than 1.1% (by mass).
4.9. ASR IN KOREA
Deterioration of concrete structures due to ASR has been mitigated in Korea by
using relatively low-alkali cement, as low as 0.50% (Yangsoo et al., 1996). Forty
samples of crushed stones used by the ready-mix concrete plants in Korea were
investigated using petrographic analysis (XRD, SEM, and polarized light
microscope), ASTM C 289, and ASTM C227 while varying the alkali content of the
mortar bars. Several aggregates were identified as being reactive, which
corresponded well with their bad field performance. ASR is being identified as a
problem in several concrete structures in Korea (Yangsoo et al., 1996).
4.10. ASR IN NORWAY
4.10.1. Evaluating the Reactivity of Aggregates
In order to determine the alkali-silica reactivity of Norwegian concrete
aggregates, two consecutive test methods are performed, namely, a petrographic
analysis (Norwegian method) and the South African accelerated mortar-bar test
(ASTM C 1260) (Jensen, 1996). Until 1993, the concrete-prism test (ASTM C 1293)
was considered a reliable method, but is no longer suitable for evaluating the alkali
reactivity of sandstones, phyllite, and concrete aggregates in general (Jensen, 1996).
97
4.10.1.1. Petrographic Analysis (Jensen, 1996)
An improved version of the ASTM C 295 petrographic analysis method was
developed to classify concrete aggregate samples. The method is based on point
counting of thin sections and is used with natural sand, coarse gravel, and crushed
stone. “Rock types are then classified according to geological nomenclature,
microstructure of the rock, degree of deformation and alteration. Results are reported
as volume percentage of major rock/minerals in addition to alkali reactivity based on
field experience.”
Rocks have been divided into three categories:
1. Reactive Aggregates: Sandstone, siltstone, cataclastic rocks, acid volcanic rocks,
argillaceous rocks, greywacke, marl and rock types with microcrystalline quartz
(grain size less than 0.06 mm).
2. Potentially reactive aggregates: Fine-grained quartzite or rock types containing
micro-(very fine)-grained quartz (crystal size 0.06 - 0.13 mm).
3. Innocuous aggregates: Gneiss, granite, coarse-grained quartzite, crystalline
limestone, gabbro, and rock types with coarse grains and/or minor amounts of
quartz.
Aggregates containing more than volume 20% reactive + potentially reactive
rocks are classified as alkali reactive. Aggregates containing less than 20% volume
reactive + potentially reactive rocks are classified as innocuous.
4.10.1.2. NBRI Accelerated Mortar-bar Test (ASTM C 1260)
This test is the same as the ASTM C 1260 test with 14-day expansions higher than
0.10%, representing reactive aggregates and lower than 0.10%, representing
innocuous aggregates (Jensen, 1996).
98
4.10.1.3. The Concrete-prism test (ASTM C 1293)
This concrete-prism test is identical to ASTM C 1293 (Jensen, 1996).
4.10.1.4. Testing Protocol
In order to identify the reactivity of an aggregate, the first step should be to
perform the petrographic analysis. If the aggregate contains less than 20% volume
reactive plus potentially reactive rocks, then the aggregate is innocuous and no
further testing is required. If the aggregate contains more than 20% volume reactive
plus potentially reactive rocks then it is recommended but not required to perform C
1260. If the aggregate exhibits 14-day expansion higher than 0.1% then it is
classified as reactive. It is noted that the C 1260 test “overrule the result from the
petrographic analysis (Jensen, 1996).”
The concrete-prism test (C 1293) is no longer recommended because of its
inability to correctly identify the alkali reactivity of sedimentary rocks for which the
test classified the aggregates as being innocuous when they were shown reactive in
the field (Jensen, 1996).
4.10.2. Preventive Measures
Specifications for minimizing the risk of damage due to AAR are limited in
Norway. “The Norwegian NS 3420, L5 from 1986, dealing with aggregates for
concrete, specifies that reactive aggregates in harmful amounts are not to be used in
concrete (Jensen, 1996).”
4.11 ASR IN PORTUGAL
In Portugal, only a few cases of ASR deterioration have been reported. As a
result, little attention has been allocated to research the reaction in concrete. As the
structures become older, more cases of ASR damage are becoming evident. Work
geared towards identifying the ASR in damaged structures and mitigating the
reaction in other structures is being performed. Work has been completed to evaluate
99
the geology and lithology of aggregates used in concrete. A map showing the
different aggregates produced in Portugal and showing their degree of reactivity has
been produced (Silva et al., 1996).
4.12 ASR IN NEW ZEALAND (St. John and Freitag, 1996)
Volcanic aggregates are the most abundant aggregates in New Zealand and their
reactivity has been recognized since 1943. The current New Zealand code of practice
for minimizing damage due to AAR requires the use of low-alkali cement and low
total soluble alkali content of concrete. This approach was considered adequate for
most concretes until recently when “the number of structures identified with AAR
has increased.” Some of the problems with this approach includes 1) errors in
determining the alkali content of a concrete and 2) variability of the alkali content of
the concrete due to the alkalis present in the environment, even if the analytical
results are correct.
The author has developed chemical techniques capable of estimating the original
alkali content of concrete. This analytical process has been verified with the
investigation of concrete samples obtained from structures. Notably, the alkali
content of the investigated concrete increased during the life of the structure causing
AAR damage even though low alkali content cement was used as specified. The
change in the alkali content was attributed to the leaching of alkalis from some New
Zealand basalt.
Concerns about the effectiveness of silica fume in reducing damage due to AAR
were noted. Expansive cracking due to AAR was produced in test specimens
containing New Zealand cements and aggregates and subjected to wetting and drying
and outdoor exposure.
100
Most of the work concerned with AAR in New Zealand has been concentrated on
field structures. Very little work has been accomplished in the laboratory for the
purpose of investigating test methods for predicting the reactivity of aggregates.
4.13 ASR IN HONG KONG (Tse and Gilbert, 1996)
Due to the rapid growth in construction, Hong Kong’s construction industry had
to depend on local aggregates of granitic origins and on imported aggregates of
mostly volcanic tuff origins. The AAR problem is still new to Hong Kong. Field
investigations have concluded that ASR is the cause of deterioration in several
structures, including sewage treatment plants. Research is currently undertaken by
several universities in order to investigate the AAR problem.
In order to minimize the AAR damage caused by using local and imported
aggregates, the Hong Kong government is specifying a 3 kg/m3 limit on the reactive
alkali content of concrete for government projects. This specified limit has been used
for all engineering and building works contracts since 1994.
4.14 ASR IN TAIWAN (Yen et al., 1996)
Forty-four aggregate sources used in Taiwan have been investigated for alkali-
silica reactivity using ASTM C 289, ASTM C 227, and ASTM C1260. It was
concluded that:
1. C 227 underestimates aggregates reactivity of most reactive aggregates tested,
and
2. C 1260 overestimated the reactivity of several aggregates.
101
4.15 ASR IN ITALY
ASR has been a matter of concern in Italy. Several investigations have been
geared towards investigating the validity of accelerated testing procedures in
predicting the reactivity of aggregates and the effectiveness of mitigation
alternatives. The most recent work has been conducted by Berra, De Casa, and
Mangialardi (1996) and Berra, Mangialardi, and Paolini (1994).
Berra et al. (1996) used two alkali-reactive aggregates to investigate the
effectiveness of the C 1260 test procedures in predicting the effects of using
supplementary cementing materials (SCM), particularly, silica fume and fly ash.
Tests performed included measurements of expansions, water permeability, pore
liquid composition, and Ca(OH)2 content. It was concluded that the testing
procedures are adequate for evaluating the effectiveness of SCM in reducing the risk
of ASR damage. The test is “suitable to accelerate the pozzolanic reactions of SCMs
such as condensed silica fume and pulverized ash.” It was also concluded that the
pozzolanic reaction causes a decrease in OH- ion concentration in the pore solution
of the mortar bars, which is caused by the reduced permeability and the incorporation
of alkali hydroxides. The decrease in OH- is responsible for the reduction in the
expansivity of alkali-reactive aggregates (Berra et al., 1996).
Berra et al. (1994) investigated the use of ASTM C 1260 in assessing the
effectiveness of fly ash and silica fume in reducing expansions caused by the alkali-
silica reaction using fused quartz as a reactive aggregate. Results of the C 1260 test
were compared against the long-term results obtained form C 227. A good
correlation was found between the results of both tests. C 1260 provided adequate
minimum contents of fly ash and silica fume needed to prevent deleterious ASR
expansions. For silica fume, it was found that the two tests provided comparable
results when the expansion limits for C 1260 and C 227 were respectively 0.25% at
102
twelve days and 0.10% at one year or alternatively, 0.15% at 14 days and 0.05% at
one year. Results from both tests did not indicate that there is a relationship between
the alkali content of the fly ash and its performance in reducing ASR expansions
(Berra et al., 1994).
4.16 ASR IN ICELAND
Between 1961 and 1979, alkali-aggregate reaction was identified as the main
cause of damage to many concrete structures (mostly housing) in Iceland. As a result,
using silica fume as a partial replacement of cement was required in order to mitigate
the problem. Twenty years later, no AAR damage has been noticed in concrete
structures. It was concluded that using silica fume is an effective method for
preventing damage due to AAR (Gudmudsson and Olafsson 1996, 1999).
4.17 ASR IN THE UNITED KINGDOM
In order to minimize the risk of damage due to alkali-aggregate reaction in
concretes containing reactive aggregates, current UK guidelines permit the use of fly
ash (Thomas Blackwell, and Nixon; 1996). However, definite advice on how to use
the fly ash in concrete and what percentages to use are not included in the guidelines
(Concrete Society, 1992) because of conflicting evidence regarding whether the
alkali content of the fly ash is available for reacting with the aggregate causing
additional damage (Thomas, Blackwell, and Nixon; 1996). This situation is
specifically a problem when the total alkali content of the concrete is being
controlled below a certain level in order to prevent AAR damage. Several
recommendations exist on how to deal with the alkali content of fly ash:
1. The Concrete Society (UK) recommends using the water-soluble alkali content of
the fly ash for determining the total alkali content of the concrete (Concrete
Society, 1992).
103
2. The Building Research Establishment (UK), Department of Transport (UK),
French Guidelines, and Ireland guidelines recommend using one-sixth of the total
alkali content of the fly ash to calculate the total alkali content of the concrete.
This is a more conservative approach since 0.40% to 0.70% Na2Oequiv. is
equivalent to 0.10% water-soluble alkali content (BRE 1988, Department of
Transportation (UK), 1992; Thomas et al., 1996).
In the UK the belief is that the use of sufficient levels of Class F fly ash is
effective in preventing ASR expansions in concretes containing natural reactive
aggregates even when the alkalis from sources other than the fly ash are enough to
cause deleterious expansions in concretes without fly ash (Thomas, Blackwell, and
Nixon; 1996). In this case, the fly ash is considered to have a positive effect and to
have no reactive alkali contribution. However, when moderate levels of fly ash are
used in concrete containing very highly reactive aggregates with low alkali content
cements, then the fly ash will likely contribute alkalis to the reaction. In this case
higher replacement levels may be required in order for the fly ash to completely
prevent the reaction from occurring (Thomas, Blackwell, and Nixon; 1996).
In a study reported on by Thomas, Blackwell, and Nixon (1996), five reactive
aggregate sources from the UK area were used to make concrete specimens using
one high-alkali portland cement (1.15% Na2Oequiv.) and three Class F fly ashes with
varying total alkali content (2.98, 3.46, and 3.86% Na2Oequiv.). Fly ash was used at
different replacement levels and concrete prisms were stored in plastic containers at
200C and 100% relative humidity. At 7 days, length measurements of all prisms were
taken before wrapping them in moist toweling and polyethylene. Some of the
wrapped prisms were stored at 200C while some were stored at 380C, all at 100%
humidity. For the particular materials used in this study (UK reactive aggregates and
104
UK Cement and Class F fly ash) it was determined that (Thomas, Blackwell, and
Nixon; 1996):
1. The effective alkali contribution of the fly ash depends upon the nature of the
reactive aggregate and the levels at which the weight of cement is replaced with
the fly ash.
2. The alkali content of concrete in the control specimens (neglecting the alkalis in
the fly ash) was enough to cause deleterious expansions and cracking of
specimens containing moderately reactive flint. Replacing the cement with 25%
fly ash was effective in reducing expansions. As a result, it was noted that the fly
ash has a positive effect in reducing damage due to ASR and does more than just
dilute the alkalis in the cement. Using the same reactive aggregate but replacing
6% of the cement with fly ash resulted in an increase in expansions for a given
cement alkali content. It was determined that 40% of the total alkalis in the fly
ash contributed to the expansions of concrete specimens.
3. Replacing 25% of the cement weight with fly ash was not effective in preventing
excessive expansions and cracking of specimens containing highly reactive
aggregates (i.e. aggregates that cause deleterious expansions with low alkali
content cement). These aggregates required using 35% fly ash by weight. The
contribution of the total alkalis in the fly ash to the expansions was estimated to
be 10%.
4. It is inappropriate to use a singular value (e.g. one-sixth of the total alkali content
in ash) to estimate the contribution of the alkalis of the fly ash to the rate of ASR.
It is dependent upon the aggregate nature and levels of replacements. In addition,
using this approach ignores mechanisms other than alkali availability that
contribute to the efficiency of the fly ash in reducing ASR damage.
5. Specifications for using fly ash as an ASR mitigation alternative should take into
consideration that highly reactive aggregates require higher amounts of fly ash in
105
the mixture. As the calcium content of the fly ash increases (Class C fly ash), the
amounts of the fly ash used in the concrete should also be increased.
4.18 ASR IN THE UNITED STATES OF AMERICA
In his 1996 paper, Hooton (1996) discussed the current status of aggregate testing
for ASR in the USA. He mentioned that ASTM C 227 and C 289 are no longer
considered reliable and are no longer used for assessing aggregate reactivity. The two
tests that are gaining popularity are ASTM C 1260-94 (CSA A23.2-25A-M94) and
ASTM C 1293-95 (CSA A23.2-25A-M94). The following are some points about the
tests (Hooton, 1996)
ASTM C 1260: Accelerated Mortar-bar test (Hooton, 1996)
1. Effect of cement: This test is only used for determining the potential reactivity of
aggregates and not to evaluate cement-aggregate combinations. The alkali
content of the cement does not have a significant effect on the test expansions
because: 1) the bars are immersed in the 1M NaOH solution at the early age of
two days, allowing the alkalis to rapidly reach the aggregate, 2) specimens are
stored at 800C which greatly accelerates the reaction, and 3) the 1M NaOH
solution represent a much higher pore solution alkalinity than what can be
reached with normal high alkali, high cement content concrete.
2. Use for evaluating the effectiveness of Supplementary Cementing Materials
(SCM): Both ASTM C 1260 and CSA A23.2-25A test methods do not suggest
using the test for evaluating the effectiveness of SCM.
3. Interpretation of Expansions: Proposed limits are 0.15% after 14 days, 0.33%
after 28 days, and 0.48% after 56 days of testing. Thus, an aggregate has to show
expansions lower than these three criteria in order to be innocuous. Aggregates
cannot be rejected based solely on C 1260 results although they can be accepted.
4. Possibilities for Modifications: The work conducted by Starks (1993) and
106
discussed later in this chapter was suggested as being a potential modification
for the ASTM C 1260 procedures.
ASTM C 1293: Concrete-Prism Expansion Test (Hooton, 1996)
The test results relate well with observed field performance. The 12-month
duration of the test is a concern, but is required for accurate results. Accelerated
results can be achieved by raising the temperature or other changes. However,
acceleration of the test may have undesirable side effects.
Hooton (1996) concluded that if an aggregate was classified as potentially
reactive when tested according to ASTM C 1260, it should be checked using C 1293
before finally concluding the aggregate reactivity. In addition, he mentioned that
ASTM needs to develop a document as guidance for the use of C 1260 and C 1293.
4.18.1 DOT Survey
A survey of the DOT’s was conducted to determine the status of ASR in the U.S.
The following were the conclusions of the survey (Figure 1.1):
1. ASR exists nationally in the U.S.
2. ASTM C 1260 and C 1293 are the two tests that are used the most. One DOT
reported the use of a modification of the C 289 test.
3. Low-alkali cement, Class F fly ash, and slag are the most popular mitigation
methods.
4.18.2 Strategic Highway Research Program (SHRP)
Starks (1993) conducted the most extensive aggregate testing work in the USA as
part of a Strategic Highway Research Program (SHRP) study. Throughout the study,
eleven aggregates found to be reactive in field applications and five aggregates
known to be innocuous were investigated (Table 4.14). After examining the results
107
of ASTM C 227 and C 289 performed on the aggregates listed in Table 4.14, it was
concluded that these two tests are inadequate for detecting slowly reactive aggregates
and that a rapid and more reliable ASR test procedure is needed. ASTM C 1260 was
the test that was chosen to be investigated in this study (Starks, 1993).
Aggregates were prepared in accordance with the requirements of C 227. Four
mortar bars were then made using (1) Type I cement, with 1.0-percent equivalent
Na2O, (2) an aggregate to cement ratio of 2.25:1.00, and (3) a fixed water to cement
ratio of 0.50. Mortar specimens representing each aggregate were then stored in
NaOH with varying normalities namely 1M, 0.75N, 0.52N, 0.35N, and 0.18N. The
varying levels of normalities were used in order to determine a cement alkali level
below which the aggregates do not exhibit deleterious expansions. This was
achieved by using the following equation (Starks, 1993):
LmolescwONaOH /06.0022.0
/2339.0][ ±+=− (Eq 4.4)
In equation 4.4, [OH-] corresponds to NaOH normality, Na2O represents the
percent Na2O equivalent of the cement, and w/c is the water-cement ratio. This
equation was developed during the SHRP-342 study (Helmuth 1993). After
examining data from the literature (Diamond, 1989; Nixon and Page, 1987; Canham
and Page, 1987; Kawamura, Kayyali, and Hague; 1988; and Larbi and Bijen, 1990)
Equation 4.4 was developed and justified.
108
Table 4.14: Aggregate Sources Investigated Throughout the Study (Starks, 93) Source Identity
Source Area
Aggregate Type
Field Performance
Deleterious AL Albuquerque, NM Mixed sand and gravel,
rhyolite to andesite Highly reactive with low-alkali cement
BK Bennettsville, SC Quartz, quartzite gravel, reactive quartzite
Slowly reactive with high-alkali cement
GH Salisbury, NC Quarried Argillite Slowly reactive with high-alkali cement
GR Charlottesville, VA Quarried metabasalt Slowly reactive with high-alkali cement
OR Barstow, CA Mixed sand and gravel, reactive rhyolite to andesite
Highly reactive with low-alkali cement
PR Princeton, NC Quarried granite to granite-gneiss
Slowly reactive with high-alkali cement
RH Charlottesville, VA Quarried granite-granite gneiss
Slowly reactive with high-alkali cement
RQ Montgomery, Al Mixed sand and gravel, reactive chert and quartzite
Reactive with low-alkali cement
SF Wilmington, DE Quarried granite-gneiss to amphibolite
Slowly reactive with high-alkali cement
SX Sioux Falls, SD Quarried quartzite Slowly reactive with high-alkali cement
TM Petersburg, VA Mixed sand and gravel, reactive chert and quartzite
Slowly reactive with high-alkali cement
WR Trenton, NJ Mixed sand and gravel, reactive chert, quartzite, granite gneiss
Slowly reactive with high-alkali cement
Innocuous
DR St. Paul, MN Quarried gabbro-diabase Non-reactive with low-alkali cement
EC Eau Claire, WI Mixed siliceous sand and gravel
Non-reactive with low-alkali cement
EL Chicago, IL Mixed carbonate and siliceous sand and gravel
Non-reactive with low-alkali cement
ML Rock Island, IL Quarried Limestone Non-reactive with low-alkali cement
TH Chicago, IL Quarried Dolomite Non-reactive with low-alkali cement
TR Central New Jersey Quarried gabbro-diabase Non-reactive with low-alkali cement
109
It was concluded that aggregates showing 14-day expansions exceeding 0.08%
should be classified as being potentially deleterious aggregates. Aggregates showing
14-day expansions lower than 0.08% can be classified as innocuous. One notable
exception, a mixed siliceous aggregate, was reported to be innocuous in field
performance and showed a 14-day expansion of 0.278% (greater than 0.08%). This
abnormality was considered to reflect “the fact that observed satisfactory field
performance was based on use with high-alkali cements that produce pore solutions
in concrete less alkaline than the 1M solution used in the test (Starks, 1993).”
Results are listed in Table 4.15.
Other conclusions included (Starks, 1993):
1. The immersion test (C 1260) can be used to estimate maximum cement alkali
levels at which deleterious ASR is not very probable. This is accomplished by
using equation 4.4 and changing the normalities of the curing NaOH solution.
2. When changing the normality of the curing solution, “the test criterion must be
adjusted progressively downward to a minimum of about 0.02 percent as solution
normality decreases to about 0.6N (Figure 4.3).”
3. The test procedures combined with a criterion of 0.08 percent expansion at
fourteen days can be effectively used to determine the mineral admixture
requirements for preventing deleterious ASR.
4. The C 1260 procedures did not result in accurate results when concrete prisms
were used. When the molarity of the solution changed from 1M to 0.70N and
0.35N the expansion of the concrete prisms decreased as expected. However, one
innocuous aggregate showed expansions higher than several reactive aggregates.
As a result, it was concluded that these procedures are not dependable for testing
concrete prisms.
110
Table 4.15: Results of the C 1260 Test (Starks, 1993)
C 1260 Expansion, %
Source Composition 4
Days 7
Days 10
Days 14
Days 21
Days 28
Days Deleterious in Field Performance
AL Granitic Volcanic 0.190 0.483 0.713 0.867 1.035 1.098
OR Granitic Volcanic 0.205 0.296 0.375 0.424 0.500 0.541 GH Argillite 0.080 0.252 0.354 0.418 0.511 0.566 RQ Chert, Quartzite 0.070 0.212 0.328 0.409 0.515 0.574 WR Chert, Quartzite 0.073 0.160 0.246 0.314 0.416 0.487 PR Granitic Gneiss 0.108 0.189 0.239 0.309 0.385 0.422 SX Quartzite 0.069 0.122 0.170 0.225 0.312 0.389 TM Chert, Quartzite 0.032 0.066 0.116 0.177 0.270 0.309 BQ Chert, Quartzite 0.042 0.063 0.073 0.106 0.142 0.196 RH Granitic Gneiss 0.013 0.032 0.065 0.096 0.132 0.164 SF Granitic Gneiss 0.044 0.038 0.064 0.086 0.124 0.146 GR Metavolcanics 0.026 0.040 0.052 0.082 0.115 0.146
Innocuous in Field Performance ML Limestone 0.025 0.024 0.029 0.026 0.035 0.024 TH Dolomite 0.028 0.047 0.066 0.066 0.077 0.078 TR Gabbro 0.014 0.022 0.029 0.044 0.066 0.102 EC Mixed Siliceous 0.055 0.076 0.181 0.278 0.329 0.388 DR Gabbro 0.032 0.027 0.061 0.075 0.157 0.263
111
0.00
0.01
0.02
0.03
0.04
0.05
0.06
0.07
0.08
0.09
0.10
0.00 0.20 0.40 0.60 0.80 1.00
NaOH Solution Normality
14-D
ay E
xpan
sion
, per
cent
TR (Innocuous)TH (Innocuous)SF (Deleterious)GR (Deleterious)WR (Deleterious)
0.00 0.23 0.52 0.82 1.1 1.4 Corresponding Cement Alkali
Equivalent Na2O (From Equation 4.4)
Figure 4.3: Failure Criteria for Determining Safe Cement Alkali Level for Deleterious Aggregates Using ASTM C 1260 (Starks, 1993)
112
4.18.3 ASR in North Carolina (Leming et al., 1996) After investigating 22 highway structures in North Carolina, it was concluded that
ten of them have experienced extensive damage and are likely to see more damage
due to ASR. The following conclusions were drawn (Leming et al., 1996):
1. The most serious problems related to ASR were associated with the use of schist,
gneiss, and phyllites as coarse aggregate. Phyllite was present in ASR damaged
structures and missing in structures without phyllite. As a result, “the presence of
phyllite should be considered likely to produce ASR.”
2. On the other hand, a number of structures containing schist and gneiss did not
undergo any damage. As a result, determining the reactivity of aggregates cannot
be accomplished by simply determining their mineralogical composition using
petrographic analysis.
3. Even though the use of low-alkali cement can be helpful, it does not ensure a
low- alkali content concrete in the field. Damaged structures were characterized
with high alkali contents.
4. Aggregates from the same source may vary widely as far as reactivity depending
on the structure.
5. Damaged structures were characterized by having low air content, “lower than
normally desired.”
4.18.4 ASR in Virginia (Lane, 1994) Alkali-silica reaction has been a major cause of the deterioration of several
concrete structures in Virginia. A report, completed by Lane (1994), examined the
occurrence of the reaction in Virginia structures. Table 4.16 summarizes the findings
of the study. The following conclusions were suggested (Lane, 1994):
1. Virginia aggregates containing microcrystalline and strained quartz have been
associated with ASR damage in the field.
113
2. The use of C 227 is not effective for identifying the reactivity of these
aggregates.
3. Cements with alkali content exceeding 0.40% should be used with a mitigation
method such as the use of fly ash, slag, or silica fume.
Table 4.16: Investigated Aggregate Source, Field Performance, and C 227
Results (Lane, 1994) C 1260 Expansion, %
Aggregate Source
Rock Type
Field Performance
C227 Expansion
5-day
8-day
11-day
14-day
28-day
C 1260 Classification
Augusta Dolomitic Limestone Undetermined 0.04 0.09 0.18 0.23 Reactive
Blacksburg Argillaceous Dolomite Good 0.03 0.05 0.07 0.09 Innocuous
Warrenton Diabase Good 0.03 0.05 0.08 0.13 0.36 Reactive
Fredericksburg Quartzose Sand Undetermined 0.02 0.05 0.06 0.09 0.2 Reactive
Fredericksburg Quartzose Gravel Undetermined 0.04 0.07 0.09 0.12 0.28 Reactive
Richmond Quartzose Sand
Alkali-silica reactive
0.045% @27 mon 0.03 0.06 0.13 0.19 0.37 Reactive
Richmond Quartzose Gravel
Alkali-silica reactive
0.016% @ 6 mon 0.13 0.21 0.27 0.32 0.49 Reactive
Rockville Hylas Metarhyolite Alkali-silica
reactive 0.014%
@ 6 mon 0.18 0.25 0.34 0.39 0.59 Reactive
Sylvatus Quartzite Undetermined 0.021% @ 6 mon 0.12 0.19 0.26 0.30 0.43 Reactive
Mt. Athos Acrch Marble Calc Chist
Alkali-silica reactive
0.012% @ 6 mon 0.03 0.08 0.12 0.17 0.30 Reactive
Shelton Granite Gneiss
Suspected Alkali-silica
reactive 0.05 0.09 0.13 0.17 0.28 Reactive
Red Hill Lovingston
Granite Gneiss
Alkali-silica reactive
0.049% @27 mon 0.03 0.04 0.06 0.07 0.14 Reactive
Shadwell Greenstone Metabasalt
Alkali-silica reactive
0.038% @27 mon 0.03 0.04 0.06 0.08 0.15 Reactive
Note: the C 1260 Classification was changed from the original data to represent the new findings for the test interpretation. Basically 14-day expansions higher than 0.08% are considered reactive.
114
4.18.5 ASR in South Dakota (polynomial and Avrami) To improve the interpretation of the C 1260 results, two models were introduced
by Johnston of the South Dakota DOT (1994). The first model consisted of using a
polynomial fit procedure on the C 1260 expansions versus time for each of the tested
aggregates and then to plot the coefficients of these curves against each other. This
process was more detailed in Johnston’s paper published in 1994. The advantage of
this model was that it considered the expansion history over the full 14-day period
instead of just using the 14-day expansion reading. According to the findings of
previous researchers, the polynomial fit procedure should show a clear separation
between innocuous and reactive aggregates with the innocuous aggregates being
concentrated around one line and reactive aggregates being concentrated along
another, separate line (Johnston, 1994).
The second model consisted of applying Avrami’s equations to the C 1260
expansions. The model, presented in 1940, described the nucleation and growth
reaction using equation 4.5 (Johnston, 1994).
α = 1 + α0 − e (-k * (t-t0)^M) (Eq 4.5)
In that equation, α0 is the degree of expansion at time t0 representing the time at
which the nucleation and growth becomes dominant. In the case of C 1260, t0 is the
fourth day of curing. The constant k in equation 4.4 is a rate constant that reflects the
effects of nucleation, multidimensional growth, the geometry of reaction products,
and diffusion. The constant M is combining the effects of parameters P, Q, and S as
described in equation 4.6 (Johnston, 1994).
M = P/S + Q (Eq 4.6)
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The parameter P describes the dimensionality of the product phase with P = 1, P =2,
and P = 3 respectively corresponding to needles, sheets, polygonal forms. S = 1
indicates a phase boundary growth while S = 2 indicates the diffusion of components
through the liquid phase. Q = 0 indicates no nucleation and Q = 1 indicates constant
nucleation. It is assumed that the characteristics of the alkali-silica reaction are (1)
sheet formation (P = 2), (2) diffusion through the liquid phase (S = 2), and (3) no
nucleation (Q = 0), which means that the value of M is almost 1 for ASR. Taking the
double natural log of both sides of Equation 1 results in equation 4.7 (Johnston,
1994):
ln ln (1 / 1+α+α0) = ln (t-t0)*M + ln(k) or Y = X*M + ln (k)
Plotting X versus Y for each aggregate will result in an intercept value for ln(k)
and a slope value for M. The validity of this model for ASR kinetics was evaluated
by Johnston in his 1998 paper. He concluded that using the model allows the correct
prediction of an aggregate reactivity with ln(k) equals to -6 being the separating
value between reactive and innocuous aggregates. Aggregates with ln(k) greater than
-6 are reactive and aggregates with ln(k) less than -6 are innocuous. He also
concluded that the model is very efficient in evaluating and predicting the
effectiveness of mitigation methods (Johnston, 1994).
4.18.6 Mid-Atlantic Regional Technical Committee (Mid-Atlantic RTC, 1993)
In June of 1993, the Mid-Atlantic Regional Technical Committee published a
report titled “Guide Specifications for Concrete Subject to Alkali-Silica Reactions.”
Recommended practices are summarized in Tables 4.17 and 4.18.
(Eq 4.7)
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Table 4.17: Recommended Testing Procedures and Limits (Mid-Atlantic RTC, 1993)
Testing Procedures Description Limits Optically strained, microfractured, or microcrystalline quartz (commonly found in granite and granite gneiss)
5.0 % (max.)
Chert or chalcedony 3.0 % (max.) Tridymite or cristobalite 1.0 % (max.) Opal 0.5 % (max.)
ASTM C 295 Petrographic Examination of Aggregates for Concrete
Natural volcanic glass 3.0 % (max.)
ASTM C 1260 Average mortar expansion after 14-day of curing in 1M NaOH at 800C 0.10 % (max.)
ASTM C 227 Average mortar expansion after 6 months 0.10 % (max.)
Aggregates containing reactive materials as determined by ASTM C 295, should
be tested using C 1260. If the aggregate still shows signs of reactivity, it should be
considered as potentially reactive unless additional testing results and service records
support its reclassification and are found to be acceptable to the specifier. C 227
might not be able to detect all reactive aggregates. However, aggregates that fail the
test should be considered potentially reactive.
Table 4.18: Recommended Mitigation Alternatives and Methods of Validation (Mid-Atlantic RTC, 1993)
Mitigation Alternative Recommended Percentage
Validation Method
Class F fly ash 15 % (min.) C 227, C 1260 Class C fly ash 25 % (min.) C 227, C 1260 Slag 25 % (min.) C 227, C 1260 Silica fume 5 % (min.) C 227, C 1260
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4.18.7 AASHTO ASR Lead State Team (Lead State Team, 1999)
In 1999, the AASHTO ASR Lead State Team published a report similar to the
Mid-Atlantic Committee report. Major recommendations are summarized in Tables
4.19 and 4.20. One of the Lead State Team recommendations was to use the
procedures detailed in SHRP C-315, Handbook for the Identification of Alkali-Silica
Reactivity in Highway Structures, in order to determine whether a concrete structure
is affected by the alkali-reactivity of aggregates.
Table 4.19: Recommended Testing Procedures and Limits (Lead State Team, 1999)
Testing Procedures Description Limits Optically strained, microfractured, or microcrystalline quartz
5.0 % (max.)
Chert or chalcedony 3.0 % (max.) Tridymite or cristobalite 1.0 % (max.) Opal 0.5 % (max.)
ASTM C 295 Petrographic Examination of Aggregates for Concrete
Natural volcanic glass 3.0 % (max.)
Mean mortar bar expansion at 14 days
0.08 % (max.) metamorphic aggregates 0.10 % (max.) all other aggregates
AASHTO T 303 (ASTM C 1260) Accelerated Detection of Potentially Deleterious Expansion of Mortar Bars Due to Alkali-Silica Reaction
Perform a polynomial fit of data at 3, 7, 11, and 14 days to determine reliability of results
Repeat the AASHTO T 303 if r2 is less than 0.95.
ASTM C 1293 Concrete Aggregates by Determination of Length Change of Concrete Due to Alkali-Silica Reaction
Mean concrete prism expansion at one year 0.04 % (max.)
ASTM C 295 should be used as verification to either T 303 or C 1293. Using C
1293, some reactive aggregates might not develop expansions greater than 0.040%
after one year. However, these aggregates will result in extensive cracking of the
concrete prism surface.
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Table 4.20: Recommended Mitigation Alternatives and Methods of Validation (Lead State Team, 1999)
Mitigation Alternative Recommended Percentage Validation Method Mineral Admixture Methods
Class F fly ash 15 % (min.) C 441, T 303, or C 1293 Class C fly ash 25 % (min.) C 441, T 303, or C 1293 Class N pozzolan Not specified C 441, T 303, or C 1293 GGBFS 25 % (min.) C 441, T 303, or C 1293 Silica fume 5 % (min.) C 441, T 303, or C 1293
Cement Methods Low-alkali cement 100 % C 441 Blended Cement 100 % T 303 or C 1293
Chemical Admixture Methods Use 4.6 liters or 5.5 kilograms (min.) per kilogram of Na2Oequiv.
C 441 or C 1293 LiNO3 Lithium Nitrate Deduct from the mix water
an equivalent volume of 85% of the LiNO3 solution.
4.18.8 Portland Cement Association (Farny and Kosmatka, 1997)
In 1997, the Portland Cement Association (PCA) published a report summarizing
the state-of-art of ASR research (Farny and Kosmatka, 1997). The flow chart shown
in Figure 4.4 summarizes the recommendation for best testing procedures.
4.18.9 The National Aggregates Association (NAA, 1999)
The National Aggregates Association (NAA) investigated the effectiveness of
ASTM C 1260 and C 1293 using aggregate samples obtained from about 150 sources
representing different regions of the United States (154 aggregates were tested).
Results of aggregates that were tested with both C 1260 and C 1293 are included in
Table 4.21.
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1. Results of C 1260 performed on fine and coarse aggregates from the same source
were not always comparable. In nearly two-third of the cases, the fine aggregates
showed higher expansions. This raises concern over the ability of C 1260 to
correctly evaluate the reactivity of coarse aggregates.
2. Eighty percent of the tested aggregates have been used in concrete for more than
ten years. Still, 73% of the aggregates showed 14-day expansions higher than
0.10% and 52% showed 14-day expansions higher than 0.20%
3. When comparing the results of C 1260 and C 1293 performed on the same
aggregates, it was observed that only two out of ten investigated aggregates were
classified as reactive using the two tests. The remaining eight aggregates were
classified as reactive when tested using C 1260 and non-reactive when tested
using C 1293.
4. Similarly, there was no correlation between the results of C 1260 and C 227.
Most aggregates classified as reactive with C 1260 were found to be non-reactive
with C 227.
5. Field service records reported by aggregates producers did not correlate with the
results of C 1260. Most aggregates classified as reactive did not cause deleterious
expansions in concrete.
6. When using C 1260, consideration should be given to the absorption of
aggregates in order to ensure a constant water-cement ratio.
7. Rejection of an aggregate for use in concrete should not be based solely on the
results of C 1260.
4.18.10 Lithium as A Preventive Measure
Recent work has been concentrated on determining the effects of lithium additives
on ASR. The use of lithium as an ASR mitigation alternative have been investigated
by several researchers including Stanton (1940), McCoy and Caldwell (1951),
Sakaguchi et al. (1989), Ong and Diamond (1993), Stark (1993), and Wang et al.
(1994). The aforementioned and other researchers have shown that lithium can be
121
used to mitigate damage due to ASR. The effective dosages varied depending on the
molar ratio Li:Na and varied between 0.6 and 0.9. ASTM C 1260 was found to be
not effective in evaluating the usefulness of lithium mainly due to the lithium
leaching out of the mortar bars and into the curing solution. It was recommended by
Starks to add lithium to the curing solution at the same rate as that used for the
mortar bars (1993).
Table 4.21: C 1260 and C 1293 Results of Testing Performed by NAA (NAA, 1999)
lot Comp F/C N/M Petro St
C126014-Day
% C 1260
Classification
C 1293 1-yr %
C 1293 Classification
004 2 C M LS OK 0.252 Reactive 0.083 Reactive 007 4 F N SI, DO WI 0.227 Reactive 0.009 Innocuous 008 4 C CG DO, SI WI 0.159 Slowly Reactive 0.020 Innocuous 017 9 F N LS ALB 0.285 Reactive 0.015 Innocuous 018 9 C CG LS ALB 0.335 Reactive 0.070 Reactive 023 12 C CG SI CO 1.061 Highly Reactive 0.196 Reactive 032 16 C M LS PA 0.041 Innocuous 0.016 Innocuous 043 21 F N SI NE 0.210 Reactive 0.012 Innocuous 049 22 F N SI CO 0.139 Slowly Reactive 0.018 Innocuous 052 23 F N SI SD 0.250 Reactive 0.012 Innocuous 055 25 F N SI CA 0.678 Highly Reactive 0.026 Innocuous 060 26 C N SI NV 1.072 Highly Reactive 0.016 Innocuous 064 28 F N SI CA 0.080 Innocuous 0.008 Innocuous 088 37 C CG DO, LS, SI NY 0.154 Slowly Reactive 0.038 Innocuous 129 48 F N SI IN 0.279 Reactive 0.007 Innocuous 139 49 F N SI MI 0.316 Reactive 0.005 Innocuous
Type: F = Fine agg., C = coarse agg. N/M: N = Natural, M = Manufactured, CG = Crushed Gravel Petro: SI = Siliceous, LS = Limestone, DO = Dolomite, U = Unknown
During the Strategic Highway Research Program, a field test was initiated to
investigate the effectiveness of lithium hydroxide monohydrate in several pavement
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sections in Albuquerque, NM (Starks 1993). Reactive aggregates were used in the
pavements in combination with a cement having 0.55% alkali content. Long-term
monitoring of the pavement is an ongoing process.
4.19 FINAL REMARKS
After reviewing the literature and examining how different countries manage the
alkali-silica reactivity of aggregates, it was clear that there is a lack of unified
procedures and guidelines. Different countries have adopted different aggregate
testing procedures and different ASR mitigation measures that best fit their needs.
Notably, there is a great interest in reliable accelerated testing procedures capable of
predicting the potential reactivity of aggregates in a short period of time. It also
seemed that ASTM C 1260, ASTM C 1293, and modifications or combinations of
these procedures are becoming more and more popular and more trusted in giving
accurate results. Some guidelines are available to manage the alkali-silica reactivity
of aggregates.
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CHAPTER FIVE
TESTING MATERIALS
5.1 AGGREGATE SELECTION
After reviewing the literature and contacting knowledgeable researchers and
industry representatives, a list of 200 aggregates was compiled from which the
selection was made for the testing program. The aggregates possessed different
physical and chemical properties, represented different regions of the USA, had
different field performances as far as ASR performance, and had different laboratory
performances when tested for ASR.
Aggregates for the testing program were acquired from fourteen different
aggregate producers providing a total of twenty-three aggregates of which ten were
coarse, twelve were fine, and one was mixed sand and gravel.
Aggregates were selected to cover the complete spectrum of ASR reactivity as
shown in Table 5.1. Aggregates were also representative of most regions of the USA
as shown in Figure 5.1. Table 5.2 contains a list of all chosen aggregates including
their types and sources.
Table 5.1: Aggregates Representing the Complete Spectrum of ASR Reactivity
Category Field Performance Laboratory Performance A Poor Reactive B Poor Inconclusive C Poor Non-Reactive D Good Non-Reactive E Good Reactive
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Table 5.2: Aggregates and Aggregate Sources Selected for the Study
Agg. Number
Aggregate I.D.
Agg. type
Aggregate Mineralogy
Aggregate Source
Category A: Poor field performance / tested reactive 1 A1-WY Coarse Rhyolite Wyoming 2 A2-WY Fine Rhyolite Wyoming
3 A3-ID Coarse Quartzite, sandstone, limestone, andesite, rhyolite Idaho
4 A4-ID Fine Quartzite, sandstone, limestone, andesite, rhyolite Idaho
5 A5-NM (PL) Coarse Rhyolite, andesite New Mexico 6 A6-NM (PL) Fine Rhyolite, andesite New Mexico 7 A7-NC Coarse Argillite N. Carolina
8 A8-VA Coarse Quartz, quartzite, granitic rock fragments, siltstone, sandstone, and natural mineral fragments
Virginia
9 A9-NE Mixed Pink granite, orthoquartzite, metaquartzite, chert, metachert and allogenic quartz
Nebraska
10 A10-PA Fine Pennsylvania Category B: Poor field performance / tested inconclusive
11 B1-MD Coarse Chlorite feldspar, quartz, and chlorite Maryland
12 B2-MD Fine Chlorite feldspar, quartz, and chlorite Maryland
13 B4-VA Fine Quartz, quartzite, granitic rock fragments, siltstone, sandstone, and natural mineral fragments
Virginia
Category C: Poor field performance / tested nonreactive (slowly reactive)
14 C1-SD Coarse Pink quartzite, pyroxene, iron oxide, sericite, clay South Dakota
15 C2-SD Fine Pink quartzite, pyroxene, iron oxide, sericite, clay South Dakota
Category D: Good field performance / Tested nonreactive 16 D1-IL Coarse Dolomite Illinois 17 D2-IL Fine Dolomite Illinois
Category E: Good field performance / tested reactive 18 E2-Ia Fine Glacial deposit, shale Iowa 19 E3-NV Coarse Natural siliceous and glassy Nevada 20 E4-NV Fine Natural siliceous and glassy Nevada 21 E6-IN Fine Natural siliceous Indiana 22 E7-NM (SA) Coarse Rhyolite, andesite New Mexico 23 E8-NM (SA) Fine Rhyolite, andesite New Mexico
126
Identifications for each aggregate tested, as specified in Table 5.2, were used
throughout the study to identify the aggregate source. The first letter indicates the
category to which the aggregate belongs. The next number indicates the number of
that aggregate in its specified category. An odd number indicates a coarse aggregate
while an even number indicates a fine aggregate. The next two letters indicate the
state from which the aggregate was sent. For example, A1-WY is a category A
coarse aggregate from Wyoming and E4-NV is a Category E fine aggregate from
Nevada. Detailed information about the history of Table 5.2 aggregates, their field
performance, and petrographic analysis can be found in Appendix D.
Field and laboratory performance of aggregates (Table 5.2) was determined using
information provided by aggregate producers and DOT’s that have extensively used
these aggregates in field applications. Information provided was summarized in
Appendix D where the history of all the aggregates is detailed.
5.2 OTHER TESTING MATERIALS
Two types of cements with an average alkali content of 0.50 and 1.14% were used
throughout the study. Admixtures included one class F fly ash, one class C fly ash,
silica fume, granulated slag, calcined clay, lithium nitrate, one high range water
reducer, and one air entraining agent. Physical and chemical properties are provided
in Tables 5.3 through 5.9.
127
Table 5.3: Chemical and Physical Properties of Type I/II Cement with High Alkali Content
Chemical Composition Physical Properties Metal Oxide Specific Surface
Element Percent Blaine 3910 cm2/g SiO2 20.90 Al2O3 4.43 Fe2O3 3.01 CaO 62.65 Soundness MgO 2.97 Autoclave Expansion 0.88 SO3 3.06 Le Chatelier’s 2
Alkali Oxide Na2O 0.35 K2O 1.21
Na2Oequiv 1.14 Set Time (min.) Phase Analysis Gilmore Vicat
C3S 53.5 Initial Set 175 80 C2S 19.6 Final Set 300 225 C3A 6.6
C4AF 9.2 Air Content
Loss of Ignition 1.68 % H20 66.2 Insoluble Residue 0.51 % Flow 84
Free Lime 1.15 % Air 8.0
128
Table 5.4: Chemical and Physical Properties of Type I/II Cement with Low Alkali Content
Chemical Composition Physical Properties Element Percent Specific Surface
Silicon Dioxide 21.30 Blaine (cm2/gm) 3530 Aluminum Dioxide 4.60 Wagner (cm2/gm) 1970 Ferric Oxide 4.10 Calcium Oxide 64.60 Magnesium Oxide 0.90 Compressive Strength Sulfur Trioxide 2.60 1-Day 2190 Loss on Ignition 1.10 3-Day 3650 Insoluble Residue 0.20 7-Day 4670 Free Lime 0.70 Tricalcium Silicate 57.00 Tricalcium Aluminate 5.20 Set Time Na2Oequiv. 0.50 Vicat Gilmore Initial Set (min.) 100 130 Final Set (min.) 210 230
Table 5.5: Chemical Properties of Granualted Slag Element Percent
SiO2 38 Al2O3 8 Fe2O3 Tr. CaO 42 MgO 7 SO3 ----
S 1 Na2Oequiv 0.4
MnO 1
129
Table 5.6: Chemical and Physical Properties of Calcined Clay Chemical Composition Physical Properties
Metal Oxide Specific Surface Element Percent Blaine ----
SiO2 52.45 Al2O3 16.91 Fe2O3 9.04 CaO 11.70 Soundness MgO 1.70 Autoclave Expansion -0.02** SO3 3.06 45 Micron, passing 95.1 %
Alkali Oxide Na2O 0.24 K2O 2.32
Na2Oequiv 1.76 Set Time (Hrs: Min) Compressive Strength, psi Gilmore Vicat
1 Day Initial Set --- 3:25** 3 Day 2950** Final Set --- 5:25** 7 Day 4110**
Air Content
Loss on Ignition 1.70 % H20 ---- Specific Gravity 2.40±0.05 % Flow ----
Normal Consistency 27.7%** % Air ---- **Indicates these tests were done using 20% replacement of cement
130
Table 5.7 Chemical and Physical Properties of the Class C Fly Ash Chemical Composition Physical Properties
Metal Oxide Element Percent
SiO2 34.99 Specific Gravity 2.63 Al2O3 20.25 Fe2O3 6.24 Retained on #325 16.57 % CaO 26.12 MgO 4.65 Water Requirement 94 % SO3 1.74
Autoclave Exp. 0.09 % Total Alkali
Na2Oequiv 1.18
Loss on Ignition 0.28 Moisture Content 0.06
Table 5.8 Chemical and Physical Properties of the Class F Fly Ash Chemical Composition Physical Properties
Metal Oxide Element Percent
SiO2 56.5 Specific Gravity 2.40 Al2O3 19.3 Fe2O3 4.7 Retained on #325 22.5 % CaO 12.3 MgO 2.3 Water Requirement 94.2% SO3 1.5
Autoclave Exp. 0.02% Total Alkali
Na2Oequiv 0.3
Loss on Ignition 0.3 Moisture Content 0.1
131
Table 5.9: Properties of Chemical Admixtures
Admixture Type Description
Conforms to
Air-Entrainment
Is a light-orange liquid product based on a high-grade saponified rosin formulation. It is chemically similar to vinsol-based products but with increased purity. Typical addition rates range from 50 to 200 mL/100 kg (3/4 to 3 fl oz/100 lbs) of cement to have 4 to 8% air.
ASTM C 260
Super-plasticizer
Is a high range water-reducing admixture that contains no added chloride. 1 liter weighs approximately 1.08 kg (9 lb/gal). It is a dispersing admixture having a capacity to disperse the cement agglomerates. Typical addition rates range from 195 to 650 mL/100 kg (3 to 10 fl oz/100 lb) of cement.
ASTM C 494
Type F
Lithium Nitrate Is a solution of LiNO3 diluted with water.
132
CHAPTER SIX
LABORATORY TESTING PROCEDURES
6.1 INTRODUCTION
The laboratory testing-program was divided into three stages:
1. Stage 1 consisted of testing each aggregate to determine the physical properties
required for concrete proportioning. Aggregates were also prepared for mortar
and concrete batching.
2. Stage 2 consisted of testing all aggregates listed in Table 5.2 using ASTM C 227,
C 1260, and C 1293. Modifications to these tests were also investigated during
this stage.
3. Stage 3 consisted of investigating ASR mitigation alternatives.
6.2 STAGE 1: AGGREGATE TESTING AND PREPARATION
Aggregate testing was divided into two phases: 1) fine aggregate testing and 2)
coarse aggregate testing. Table 6.1 shows a list of all aggregate tests performed on
both fine and coarse aggregates.
Table 6.1: Aggregate Testing Performed
Aggregate Test Fine Coarse ASTM C 29 : “Unit Weight and Voids in Aggregate” ASTM C 127:“Specific Gravity and Absorption of Coarse Aggregate” ASTM C 128: “Specific Gravity and Absorption of Fine Aggregate” ASTM C 136: “Sieve Analysis of Fine and Coarse Aggregates”
= Test performed for this aggregate type
ASTM C 227 and C 1260 require that all aggregates be graded as per Table 6.2.
As a result, all aggregates had to be separated into the required sieve sizes, washed
over a #100 sieve, and then combined using the specified quantities for each sieve.
ASTM C 1293 requires that the coarse aggregate be proportioned as described in
133
Table 6.3. Again all coarse aggregates were sieved and aggregate portions retained
on the specified sieves were separated into different containers. Before concrete
batching, the different sizes were combined in accordance with the requirements of
Table 6.3. Fine aggregates to be tested according to C 1293 did not require any
processing and were tested as supplied. Figures 6.1 and 6.2 illustrate the aggregate
preparation procedures.
Table 6.2: ASTM C 227 and C1260 Aggregate Grading Requirements
Sieve Size Passing Retained on Mass, %
4.75 mm (No. 4) 2.36 mm (No. 8) 10 2.36 mm (No. 8) 1.18 mm (No. 16) 25 1.18 mm (No. 16) 600 µm (No. 30) 25 600 µm (No. 30) 300 µm (No. 50) 25 300 µm (No. 50) 150 µm (No. 100) 15
Table 6.3: ASTM C 1293 Coarse Aggregate Grading Requirements
Sieve Size Passing Retained on Mass, %
19 mm (3/4-in) 12.5 mm (1/2-in) 33 12.5 mm (1/2-in) 9.5 mm (3/8-in) 33 9.5 mm (3/8-in) 4.75 mm (No. 4) 33
134
Figure 6.1: Aggregate Washing Over #100 Sieve
Figure 6.2: Sieve Sizes Required For C 227 and C 1260 Mortar Bars
135
6.3 STAGE 2: TESTING FOR THE POTENTIAL ALKALI-SILICA
REACTIVITY OF AGGREGATES
6.3.1 Aggregate Testing Using ASTM C 227
All the fine aggregates listed in Table 5.2 were sieved, washed over a #100 sieve,
and combined in accordance with Table 6.2 to cast 1-in. x 1-in. x 11-in. mortar bars.
A total of two bars per aggregate were made. A fixed water-cement ratio of 0.47 was
used for all the mixtures instead of the range of flow numbers (flow between 105 and
120) specified by the actual testing procedures. The flow of all mixtures was
determined in accordance with the procedures detailed in ASTM C 109,
“Compressive Strength of Hydraulic Cement Mortars,” and the unit and air content
in accordance with the requirements of ASTM C 138, “Weight per Cubic Foot, Yield,
and Air Content of Concrete.” After fabrication, the bars were stored for 24 hours,
while still in the forms, in a moisture room. All bars were then demolded and stored
in sealed containers over water in an environmental room at 100oF. Absorbent
material around the walls of the containers was not used. Expansion data were
recorded after 14 days of curing and then every 1, 2, 3, 4, 6, 9, and 12 months.
Aggregate-cement combinations showing 3-month expansions higher than 0.05% or
6-month expansions higher than 0.10% were considered ASR reactive. Aggregate-
cement combinations showing 3-month expansions higher than 0.05% but 6-month
expansions lower than 0.10% were considered innocuous. Procedures for this test are
summarized in Figures 6.5 and 6.6. Figures 6.3 and 6.4 show some of the mortar bar
mixing procedures.
6.3.2 Aggregate Testing Using ASTM C 1260
In a similar manner to the C 227 procedures, aggregates were also used to cast 1-
in. x 1-in. x 11-in. mortar bars. Three mortar bars were cast using each of the
aggregates. All mixtures were also tested for flow, unit weight, and air content in
accordance with the requirements of ASTM C 109 and C 138 respectively. After 24
136
hours of moist curing, bars were stored in water at 80oC for 24 hours after which the
initial readings were recorded. Subsequent measures consisted of storing the bars in
a 1N NaOH solution at 80oC and recording expansion readings at 4, 7, 11, 14, 21,
and 28 days. A 14-day expansion greater than 0.20% indicated a potentially reactive
aggregate in the field, while a 14-day expansion smaller than 0.10% indicated a non-
reactive (innocuous) aggregate. Recent specifications have mentioned that 14-day
expansions higher than 0.10% should be used to classify aggregates as reactive.
Figures 6.7 and 6.8 show the curing process while Figure 6.9 includes a summary of
the C 1260 procedures.
Figure 6.3: Mortar bars cured for 24 hours in a moisture room, immediately after being formed (C 227 and C 1260)
Figure 6.4: Mortar bars stored over water, in containers with no wicks, in an environmental room at 380C
Figure 6.5: First Step in Performing ASTM C 227
Either Use Emmediately orStore in Jars for Later Use
Weight 330-g of Cement
Pass Cement Through a No.20 Sieve
Select Cement Type
Cement Handling
Put Excess Materials in a Plastic Bagand Store it with the Original Aggregate
Move Weighted Sample to 70-deg Rm24-hrs Before Mixing
Weight 675-g Sample,Label, and Store
Sieve for 5-min. in 300-g incrementsStop Sieving When Required Amount
is Obtained
Oven Dry
Wash Over #100 Sieve
Mix Fine AggregateSample 2000g w/Sampling Tube
No Project RequirementsSands Satisfy Table 1
Remove Materials Retained onNo.4 Sieve
Mix Fine AggregateSample 2000g w/Sampling Tube
Required Project Grading
Fine Aggregate
Wash Aggregate While on Sieve
Wash Over #100 Sieve
Sample Approximately 10-lbswith Sample Splitter
Crushed Coarse Aggregate Satisfying Table 1 Requirements
Choose Aggregate and Assign Number
Aggregate Handling
137
Figure 6.6: Second Step in Performing ASTM C 227
(See ProportioningDirections)
(See Mixing and MoldingProcedures)
Not needed when duplicatemortar is made for additionalspecimens
Return Containers to 100-DegRoom
Take Readings at1,2,3,4,6,9, and 12-Months Examine Specimens
Day 0
Day 1
Day 2
Day 14Day 15 1-year
(1) Strip Molds (2) Label Bars
Take 14-Day Readings Clean Container, Change WaterReturn Specimens in Inverted Position
Take Containers Out and Placefor at Least 16-Hrs at 73.4-Deg
Place Specimens in Containersin 100-Deg. Envir. for 12-Days
(3) Record Initial Reading (4) Clean Molds and Assemble
Place Specimens in Moisture Rm for 24 hrs
Fill the Molds, 2-Min 15-s
Run Flow Test and Return Materials toMixing Bowl, Mix for 15-s
Mix the Mortar
Assemble Molds, Oil with Agentand Set Gage Studs
Set Up Data Booksand Schedule Readings
Proportion Dry Materials
138
139
Several research programs and papers in the literature have documented the
effectiveness of C 1260 for predicting the potential alkali-reactivity of aggregates
and for investigating the effectiveness of mitigation alternatives such as the use of air
entrainment, mineral admixtures, pozzolans, and chemical admixtures. In general,
most of the researchers and users agreed that this test is a good ASR predictor;
however, it is too severe for some aggregates that have had good field performances
(Category E aggregates). To overcome this obstacle, several modifications of the C
1260 were investigated including:
1. Using different interpretation methods: Avrami’s model and the polynomial fit
procedures, both of which were discussed earlier.
2. Changing the molarity of the curing solution: 0.75N, 0.50N, and 0.25N.
3. Expanding the length of testing from 14 days to 56 days.
4. Changing the water content of the mixing proportions so as to account for the
absorption of the tested aggregate. The water-cement ratio is controlled at 0.47.
This modification was not used to remedy the Category E problem but to
improve the consistency of the mixing procedures.
140
Figure 6.7: Mortar bars stored in a 1N NaOH solution used for C 1260
Figure 6.8: Mortar bars stored in an oven at 800C, in 1N NaOH solutions (C 1260 requirements)
Figure 6.9: ASTM C 1260 Procedures
(See ProportioningDirections)
(See Mixing and MoldingProcedures)
Take 4-Day Readings Take 7-Day Readings Take 11-Day Readings Take 14-Day Readings
Clean Molds and Assemble
Day 0
Day 1
Day 2Day 3Day 7 Day 10 Day 14 Day 17
Strip Molds Label Bars
Place Specimens in NaOH Solutionin 176-Deg. Envir.
Remove Containers One at aTime and Take Zero Readings
Place Specimens in H20in 176-Deg. Envir. for 24-Hrs
Prepare the NaOH Solutionand STore in Comtainers at 176-deg
Record Initial Reading
Place Specimens in Moisture Rm for 24 hrs
Mix Mortarand Prepare Bar Specimens
Assemble Molds, Oil with Agentand Set Gage Studs
Set Up Data Booksand Schedule Readings
Proportion Dry Materials
141
142
6.3.3 Aggregate Testing Using ASTM C 1293
Aggregates listed in Table 5.2, including fine and coarse aggregates, were used to
cast 3-in. x 3-in. x 11-in. concrete prisms in accordance with the requirements of
ASTM C1293. All mixtures were batched using the procedures described in ASTM
C 192, “Making and Curing Concrete Test Specimens in the Laboratory,” tested for
the slump according to ASTM C 143, “Slump of Portland Cement Concrete”, and
tested for the unit weight and air content as described in ASTM C 138. Prisms were
covered with a plastic sheet and stored in a moisture room immediately after
fabrication. After 24 hours of curing, prisms were demolded and subjected to the
following testing conditions:
1. Over water, in a sealed 6-gal bucket with absorbent material covering the sides,
and in an environmental room at 38oC (3 prisms/container). These are the
requirements of C 1293. The failure criterion for this test is 0.040% after 0ne
year of testing.
2. Over water, in a sealed 6-gal bucket with absorbent material covering the sides,
and in an environmental room at 60oC. The proposed failure criterion for these
procedures is 0.040% after 3 months of testing. This criterion was obtained from
the literature and will be discussed in Chapter 10.
3. In a 1N NaOH solution at 38oC. 2.2-liter containers were used (2
prisms/container). This is a proposed modification process that will result in
accelerated ASR results. The proposed failure criterion for these procedures is
0.040% after 26 weeks (6 months) of testing. This criterion was obtained from
the literature and will be discussed in Chapter 10.
4. In a 1N NaOH solution at 80oC. 2.2-liter containers were used (2
prisms/container). This is a modification that will result in yet more accelerated
results. The proposed failure criterion for these procedures is 0.040% after 4
143
weeks of testing. This criterion was obtained from the literature and will be
discussed in Chapter 10.
The initial readings were taken immediately after demolding, and readings were
recorded after 1, 2, 4, 6, 8, 13, 26, 39, and 52 weeks of curing. The estimated length
of C 1293 is one year. As a result, readings for prisms under the different conditions
continued for one year. Figures 6.10 through 6.13 illustrate several of the steps in
ASTM C 1293. Figures 6.14 and 6.15 contain a summary of the C 1293 procedures
that are common to all modifications. The only difference was the storage
environment.
Figure 6.10: Concrete prisms stored over water, in 6-gal buckets with wicks, in an environmental room at 380C
144
Figure 6.11: C 1293 buckets stored for 16 hours in a moisture room before measuring scheduled expansion readings
Figure 6.12: Top view of a C 1293 bucket; Concrete prisms over water;
Wicks on the sides; Seal cover
Figure 6.13: Concrete prism being measured for expansion
Figure 6.14: Aggregate Preparation for C 1293
Dry the Sand and Either Store or Test
Batch Sized Quantities Required forMixing
Blend the Material With the Sand
Remove Required Sand Fraction toProvide FM = 2.70 (from a portion)
Run, Specific Gravity, Absorption,Sieve Analysis, and Void Content
Sample Aggregate in DampCondition
Non-Reactive Fine Aggregate
Sample Quantities for Mixing fromthe Damp Sand not the Tetsed.
Oven DryStore
Run a Void Content Test by Recombiningthe Sieve Analysis Sample in the
Standard Grading
Use 500-g for a Sieve Analysis andPassing No.200
Determine Absorption andSpecific Gravity
Split the Sample and Obtain1000-g
Sample 2000g w/Sampling Tubeand Oven Dry
Fine Aggregate to Be Evaluated
Obtain Mixing Quantities From theDRUW Sample
Determine Specific Gravity andAbsorption
Split the Sample to Obtain 3000-g
Determine DRUWUsing a 0.2 cu.ft. Container
Sample About 30-lbRecombine According to Table 1
Wash Sample over No.4 SieveOven Dry
Coarse Aggregate to be Evaluated
Recombine Size Fractions inQuantities Used for Test
Determine Dry-Rodded Unit Weight (1/2 cu.ft. bucket)
Separate Aggreagte Into Table 1 Sizes
Determine Specific Gravityand Absorption
Non-Reactive Coarse Aggregate
Aggregate Handling
145
Figure 6.15: C 1293 Concrete Prism Procedures
(See ProportioningDirections)
(See Mixing and MoldingProcedures)
Not needed when duplicatemortar is made for additionalspecimens
Return Containers to 100-DegRoom
Take 28, 56-Day Readingsand 3,6,9,12-Months.
Examine Specimens
Day 0
Day 1
Day 2
Day 7Day 8 1-year
(1) Strip Molds (2) Label Bars
Take 7-Day Readings Clean Container, Change WaterReturn Specimens in Inverted Position
Take Containers Out and Placefor at Least 16-Hrs at 73.4-Deg
Place Specimens in Containersin 100.4-Deg. Envir. for 6-Days
(3) Record Initial Reading (4) Clean Molds and Assemble
Place Specimens in Moisture Rm for 24 hrs
Fill the Molds
Run Slump, Yield, and Air Content TestsReturn Concrete to Mixer
Mix the Mortar
Assemble Molds, Oil with Agentand Set Gage Studs
Set Up Data Booksand Schedule Readings
Proportion Dry Materials
146
147
6.4 STAGE 3: ASR MITIGATION ALTERNATIVES
ASTM C 1260 and C 1293 were used to evaluate the effects of Class C fly ash,
Class F fly ash, silica fume, granulated slag, calcined clay, lithium nitrate (LiNO3),
air content, and permeability on the ASR reactivity of selective aggregates. C 1293
was used to evaluate three aggregates of which one was highly reactive, one was
moderately reactive, and one was slowly reactive. Due to the short period of time
over which C 1260 can be conducted, six aggregates were chosen to evaluate the
mitigation alternatives using the test. The same aggregates used with C 1293 were
used with C 1260 with the addition of one highly reactive aggregate, one slowly
reactive aggregate, and one aggregate from Group E (Table 5.2). These aggregates
were chosen after the first run of C 1260 was completed, and the aggregates were
classified between highly reactive and innocuous according to their 14-day
expansions. Table 6.4 summarizes the aggregates investigated and tests
combinations.
All the concrete mixtures representing the mitigation alternatives mentioned in
Table 6.4 were tested for compressive strength as described in ASTM C 39,
“Compressive Strength of Cylindrical Concrete Specimens,” the modulus of
elasticity in accordance with ASTM C 469, “Static Modulus of Elasticity and
Poisson’s Ratio of Concrete in Compression,” the splitting tensile strength as
detailed in ASTM C 496, “Splitting Tensile Strength of Cylindrical Concrete
Specimens,” and the rapid chloride permeability according to ASTM C 1202, “Rapid
Chloride Ion Penetration Test.” These properties were needed to determine how the
mitigating alternatives are affecting the mixtures and to be able to determine whether
a decrease in aggregates reactivity is due to the method being investigated or due to
the decrease in permeability or any other property.
148
Table 6.4: Aggregates and Test Combinations Used to Investigate Mitigation Alternatives
ASTM C 1260 ASTM C 1293 Agg. # 6: A6-NM (Highly Reactive) Agg. # 4: A4-ID (Highly Reactive) Agg. # 2: A2-WY (Moderately Reactive) Agg. # 12: B4-VA (Slowly Reactive) Agg. # 14: C2-SD (Slowly Reactive) Agg. # 22: E2-IA
Note: Refer to Table 5.2 for aggregate notation and source locations = Aggregate evaluated using this test
6.5 SUMMARY OF THE TESTING PROGRAM
A summary of the testing program is included in Table 6.5 that includes standard
tests, modifications, and mitigation alternatives investigated.
149
Table 6.5: Summary of the Testing Program Tests investigated Mitigation Alternatives (C 1260, C 1293)
ASTM C 227 (Modified) - No Wicks - Fixed W/C = 0.47 - High alkali cement (≈ 1.25%Na2Oe) - Estimated length: 1-yr
Effect of Class C Fly Ash - 20%, 27.5%, 35% replacement by weight of cement
ASTM C 1260 (Standard) - Mortar 1N NaOH @ 800C - 14-day expansion
Effect of Class F Fly Ash - 15%, 25% replacement by weight of cement
ASTM C 1260M1 (Modified) - Mortar 1N NaOH @ 800C
- 14-day expansion - 0.25N, 0.5N, 0.75N NaOH @ 800C
Effect of Silica Fume - 5%, 10% replacement by weight of cement
ASTM C 1260M2 (Modified) - Mortar 1N NaOH @ 800C - 14-day, 28-day, 56-day expansion
Effect of Granulated Slag - 25%, 50%, 70% replacement by weight of cement
ASTM C 1260M3 (Modified) - Mortar 1N NaOH @ 800C - 14-day expansion - Avrami’s Model
Effect of Calcined Clay - 17%, 25% replacement by weight of cement
ASTM C 1260M4 (Modified) - Mortar 1N NaOH @ 800C - 14-day expansion - Polynomial Fit Procedures
Effect of Lithium Nitrate - 3.5L, 4.5L, 10L per 1-kg of Na2Oeq
ASTM C 1260M5 (Modified) - Mortar 1N NaOH @ 800C - 14-day expansion - W/C = 0.47 counting for absorption of Aggregates
Effect of Permeability by changing W/C (Fixed cement content and increasing water)
- W/C = 0.35, 0.55, 0.65
ASTM C 1293 (Standard) - Prisms Over Water @ 380C - Estimated length: 1-yr
Effectiveness of the above alternatives with different alkali content of mortar bars - C 1260M1; 0.5N and 0.75N
ASTM C 1293M1 (Modified) - Prisms Over Water @ 600C - Estimated length: 3 to 6 months
Low alkali mortar and concrete - C 1260M1; 0.25N, 0.5N, 0.75N - C 1293M1; 0.5%, 0.75%, 1.25% Na2Oe
ASTM C 1293M2 (Modified) - Prisms in 1N NaOH @ 380C - Estimated length: 6-months
ASTM C 1293M3 (Modified) - Prisms in 1N NaOH @ 800C - Estimated length: 8-weeks
150
CHAPTER SEVEN
MIXTURE PROPORTIONS
7.1 ASTM C 227 MIXTURE PROPORTIONS
ASTM C 227 was used to evaluate the aggregates listed in Table 5.2 for their
potential alkali-silica reactivity. A water-cement ratio by weight of 0.47 was used for
all mixtures. The absorption capacity of the aggregates tested (before sieve
separation) was considered in the calculation of the water demand. Table 7.1
includes a description of the mixtures investigated.
Table 7.1: Proportions and Mortar Properties for C 227 Mixtures
Agg. ID
Mixing Date
Cement g
(Note 2)
Agg. Dry
Weightg
(Note 2)
Water g
(Note 2) Flow
(Note 3)
Unit Weight kg/m3
(lb/ft3) (Note 4)
Air Content,
% (Note 4)
A1-WY 3/10/99 740 1665 361 64.5 2184 (136.3) 2.86 A2-WY 2/3/99 740 1665 361 115.0 2194 (137.0) 2.29 A4-ID 2/4/99 740 1665 380 108.5 2142 (133.8) 2.78
A6-NM 2/5/99 740 1665 376 109.5 2175 (135.8) 1.18 A7-NC 2/6/99 740 1665 357 41.5 2258 (141.0) 2.67 A9-NE 1/27/99 740 1665 353 116.5 2211 (138.0) 1.75 B2-MD 1/28/99 740 1665 361 69.0 2205 (137.7) 1.79 B4-VA 3/10/99 740 1665 348 87.0 2184 (136.3) 2.52 C2-SD 1/27/99 740 1665 353 83.5 2205 (137.7) 2.38 D2-IL 1/28/99 740 1665 378 106.0 2202 (137.5) 2.18 E2-IA 2/1/99 740 1665 366 97.0 2182 (136.2) 2.70 E4-NV 2/2/99 740 1665 443 81.0 1988 (124.1) 1.63 E6-IN 2/3/99 740 1665 366 113.0 2216 (138.3) 1.38
E8-NM 2/4/99 740 1665 370 98.0 2200 (137.3) 1.18 Note 1: Refer to Table 5.2 for Nomenclature Note 2: Weights were calculated on a 5-bars basis
Note 3: ASTM C 109 used to measure the Flow Note 4: ASTM C 138 used to measure the Unit Weight and Air Content
151
7.2 ASTM C 1260 MIXTURE PROPORTIONS
As mentioned earlier, this test was used to investigate its validity in predicting the
alkali-silica reactivity of aggregates in concrete and to investigate potential ASR
mitigation alternatives. Aggregates listed in Table 5.2 were tested using the C 1260
method and mixture proportions are included in this section. Mixture proportions for
the completed procedures are shown in Tables 7.2 through 7.11. In the following list
of tables, ASTM C 138 was used to measure the unit weight, yield, and air content;
ASTM C 109 was used to measure the flow. The unit weight is represented by the
Greek symbol γ and the water-to-cementitious materials ratio by "W/CM." All
weights shown were calculated on a three-mortar-bar basis.
Table 7.2: Mortar Mixtures Used for ASTM C 1260, C 1260M1, C 1260M2, C 1260 M3, AND C 1260M4 (See Table 6.5)
Mix ID
Graded Aggregate
Dry Weight,
g
Cement, g
Water,g
W/CMby
Mass
γ kg/m3
γ lb/ft3
Yield ft3
Flow
Total Air
Content%
A1-WY 990 440 207 0.47 2234.5 139.5 0.03 54.5 1.35 A2-WY 990 440 207 0.47 2251.9 140.6 0.03 78.5 0.48 A4-ID 990 440 207 0.47 2171.7 135.6 0.03 76.0 2.86
A6-NM 990 440 207 0.47 2223.4 138.8 0.03 87.5 0.26 A7-NC 990 440 207 0.47 2274.3 142.0 0.03 36.0 2.49 A9-NE 990 440 207 0.47 2235.0 139.5 0.03 120.0 1.03 A10-PA 990 440 207 0.47 2237.6 139.7 0.03 45.0 1.11 B2-MD 990 440 207 0.47 2236.0 139.6 0.03 50.5 1.09 B4-VA 990 440 207 0.47 2215.7 138.3 0.03 82.0 1.89 C2-SD 990 440 207 0.47 2217.6 138.4 0.03 75.5 2.19 D2-IL 990 440 207 0.47 2220.5 138.6 0.03 78.0 2.88 E2-IA 990 440 207 0.47 2224.1 138.8 0.03 75.0 1.71 E4-NV 990 440 207 0.47 2054.8 128.3 0.03 0.0 1.70 E6-IN 990 440 207 0.47 2233.6 139.4 0.03 103.0 1.49
E8-NM 990 440 207 0.47 2232.9 139.4 0.03 86.0 0.73 Note 1: Aggregate absorption neglected for water calculation
152
Table 7.3: Mortar Mixtures Used to Evaluate the Effect of Class C Fly Ash
Mixture ID
Graded Aggregate
Dry Weight
g
Cementg
H2Og
Class CFly Ash
g
W/CM by
Mass
γ kg/m3
γ lb/ft3
Yield ft3 Flow
Total Air
Content%
WY-FAC-20 990 352 207 88 0.47 2226.0 139.0 0.03 108.0 0.88 WY-FAC-27.5 990 319 207 121 0.47 2224.1 138.8 0.03 117.0 0.68 WY-FAC-35 990 286 207 154 0.47 2216.9 138.4 0.03 116.5 0.72 ID-FAC-20 990 352 207 88 0.47 2181.7 136.2 0.03 97.0 1.68
ID-FAC-27.5 990 319 207 121 0.47 2194.5 137.0 0.03 97.0 0.82 ID-FAC-35 990 286 207 154 0.47 2176.2 135.9 0.03 110.5 1.37
NM-FAC-20 990 352 207 88 0.47 2196.9 137.1 0.03 107.5 0.71 NM-FAC-27.5 990 319 207 121 0.47 2203.1 137.5 0.03 114.5 0.15 NM-FAC-35 990 286 207 154 0.47 2190.7 136.8 0.03 124.5 0.43 VA-FAC-20 990 352 207 88 0.47 2205.7 137.7 0.03 112.5 1.58
VA-FAC-27.5 990 319 207 121 0.47 2206.9 137.8 0.03 119.0 1.25 VA-FAC-35 990 286 207 154 0.47 2214.1 138.2 0.03 117.5 0.65 SD-FAC-20 990 352 207 88 0.47 2181.7 136.2 0.03 82.5 3.04
SD-FAC-27.5 990 319 207 121 0.47 2183.4 136.3 0.03 102.5 2.69 SD-FAC-35 990 286 207 154 0.47 2188.4 136.6 0.03 104.5 2.19 IA-FAC-20 990 352 207 88 0.47 2204.8 137.6 0.02 82.5 2.01
IA-FAC-27.5 990 319 207 121 0.47 2216.7 138.4 0.02 102.5 1.20 IA-FAC-35 990 286 207 154 0.47 2204.8 137.6 0.02 104.5 1.45
Note 1: Aggregate absorption neglected for water calculation
153
Table 7.4: Mortar Mixtures Used to Evaluate the Effect of Class F Fly Ash
Mixture ID
Graded Aggregate
Dry Weight
g
Cementg
H2Og
Class F
Fly Ash
g
W/CM by
Mass
γ kg/m3
γ lb/ft3
Yield ft3 Flow
Total Air
Content%
WY-FAF-15 990 374 207 66 0.47 2228.6 139.1 0.02 98.0 0.62 WY-FAF-25 990 330 207 110 0.47 2226.7 139.0 0.02 113.0 0.11 ID-FAF-15 990 374 207 66 0.47 2195.0 137.0 0.03 92.5 0.94 ID-FAF-25 990 330 207 110 0.47 2202.9 137.5 0.02 113.0 0.00
NM-FAF-15 990 374 207 66 0.47 2195.7 137.1 0.03 99.0 0.62 NM-FAF-25 990 330 207 110 0.47 2182.4 136.2 0.02 104.0 0.64 VA-FAF-15 990 374 207 66 0.47 2196.2 137.1 0.03 91.5 1.87 VA-FAF-25 990 330 207 110 0.47 2214.3 138.2 0.02 96.0 0.47 SD-FAF-15 990 374 207 66 0.47 2216.9 138.4 0.03 83.5 1.33 SD-FAF-25 990 330 207 110 0.47 2206.7 137.8 0.02 100 1.20 IAFAF-15 990 374 207 66 0.47 2206.7 137.8 0.03 83.5 1.60 IA-FAF-25 990 330 207 110 0.47 2206.9 137.8 0.02 100 1.00 * Aggregate absorption neglected for water calculation
Table 7.5: Mortar Mixtures Used to Evaluate the Effect of Silica Fume
Mixture ID
Graded Aggregate
Dry Weight
g
Cementg
H2Og
Silica Fume
g
W/CM by
Mass
� kg/m3
� lb/ft3
Yield ft3 Flow
Total Air
Content%
WY-SF-5 990 418 207 22 0.47 2208.8 137.9 0.03 75.5 2.09 WY-SF-10 990 396 207 44 0.47 2183.1 136.3 0.03 52.0 2.94
ID-SF-5 990 418 207 22 0.47 2174.5 135.8 0.03 57.0 2.44 ID-SF-10 990 396 207 44 0.47 2135.7 133.3 0.03 27.5 3.90 NM-SF-5 990 418 207 22 0.47 2201.9 137.5 0.03 74.0 0.93
NM-SF-10 990 396 207 44 0.47 2203.4 137.6 0.03 49.0 0.57 VA-SF-5 990 418 207 22 0.47 2209.1 137.9 0.03 59.0 1.89
VA-SF-10 990 396 207 44 0.47 2203.8 137.6 0.03 31.5 1.83 SD-SF-5 990 418 207 22 0.47 2198.8 137.3 0.03 57.0 2.73
SD-SF-10 990 396 207 44 0.47 2200.3 137.4 0.03 42.0 2.37 IA-SF-5 990 418 207 22 0.47 2228.6 139.1 0.03 57 1.22
IA-SF-10 990 396 207 44 0.47 2216.7 138.4 0.03 42 1.45
154
* Aggregate absorption neglected for water calculation
Table 7.6: Mortar Mixtures Used to Evaluate the Effect of Granulated Slag
Mixture ID
Graded Aggregate
Dry Weight
g
Cement g
H2Og
Granulated Slag
g
W/CM by Mass
γ kg/m3
γ lb/ft3
Yield ft3 Flow
Total Air
Content%
WY-SL-40 990 264 207 176 0.47 2207.4 137.8 0.02 94.0 0.96
WY-SL-55 990 198 207 242 0.47 2206.0 137.7 0.02 79.5 0.46
WY-SL-70 990 132 207 308 0.47 2201.5 137.4 0.02 72.5 0.11
ID-SL- 40 990 264 207 176 0.47 2191.7 136.8 0.02 64.5 0.49
ID-SL- 55 990 198 207 242 0.47 2186.2 136.5 0.02 52.5 0.18
ID-SL- 70 990 132 207 308 0.47 2171.0 135.5 0.02 50.5 0.33
NM-SL-40 990 264 207 176 0.47 2181.5 136.2 0.02 86.0 0.67
NM-SL-55 990 198 207 242 0.47 2178.6 136.0 0.02 72.0 0.25
NM-SL-70 990 132 207 308 0.47 2169.1 135.4 0.02 67.5 0.14
VA-SL-40 990 264 207 176 0.47 2199.5 137.3 0.02 73.5 1.12
VA-SL-55 990 198 207 242 0.47 2207.4 137.8 0.02 71.0 0.21
VA-SL-70 990 132 207 308 0.47 2183.4 136.3 0.02 66.5 0.74
SD-SL- 40 990 264 207 176 0.47 2187.6 136.6 0.02 66.5 2.04
SD-SL- 55 990 198 207 242 0.47 2198.1 137.2 0.02 59.5 1.01
SD-SL- 70 990 132 207 308 0.47 2197.9 137.2 0.02 52.5 0.46
IA-SL- 40 990 264 207 176 0.47 2187.6 136.6 0.02 66.5 2.04
IA-SL- 55 990 198 207 242 0.47 2198.1 137.2 0.02 59.5 0.82
IA-SL- 70 990 132 207 308 0.47 2181.0 136.2 0.02 52.5 1.04
* Aggregate absorption neglected for water calculation
155
Table 7.7: Mortar Mixtures Used to Evaluate the Effect of Lithium Nitrate
Mixture ID LiNO3
Graded Aggregate
Dry Weight
g
Cementg
H2Og
W/CM by Mass
γ kg/m3
γ lb/ft3
Yield Ft3 Flow
Total Air
Content%
WY-LI-21 21 990 440 207 0.47 2175.5 135.8 0.03 76.5 3.86
WY-LI-28 28 990 440 207 0.47 2185.3 136.4 0.03 83.5 3.43
WY-LI-60 60 990 440 207 0.47 2219.6 138.6 0.03 96.0 1.91
ID-LI- 21 21 990 440 207 0.47 2139.2 133.5 0.03 85.0 4.32
ID-LI- 28 28 990 440 207 0.47 2128.0 132.8 0.03 84.0 4.82
ID-LI- 60 60 990 440 207 0.47 2182.9 136.3 0.03 83.0 2.36
NM-LI- 21 21 990 440 207 0.47 2196.5 137.1 0.03 101.0 1.47
NM-LI- 28 28 990 440 207 0.47 2198.6 137.3 0.03 98.0 1.37
NM-LI- 60 60 990 440 207 0.47 2190.9 136.8 0.03 105.5 1.72
VA-LI- 21 21 990 440 207 0.47 2147.6 134.1 0.03 82.0 4.91
VA-LI- 28 28 990 440 207 0.47 2206.6 137.8 0.03 82.5 2.29
VA-LI- 60 60 990 440 207 0.47 2192.7 136.9 0.03 82.2 2.91
SD-LI- 21 21 990 440 207 0.47 2189.9 136.7 0.03 75.5 3.42
SD-LI- 28 28 990 440 207 0.47 2162.9 135.0 0.03 75.2 4.60
SD-LI- 60 60 990 440 207 0.47 2167.1 135.3 0.03 75.9 4.42
* Aggregate absorption neglected for water calculation
156
Table 7.8: Mortar Mixtures Used to Evaluate the Effect of Entrained Air
Mixture ID
Graded Aggregate
Dry Weight
g
Cement g
H2Og
W/CM by
Mass
γ kg/m3
γ lb/ft3
YieldFt3 Flow
Total Air
Content %
EntrainedAir
Content%
WY-AE-4 990 440 207 0.47 2164.1 135.1 0.03 99.5 4.36 3.88 WY-AE-8 990 440 207 0.47 2087.9 130.3 0.03 94.0 7.73 7.25 ID-AE-4 990 440 207 0.47 2084.5 130.1 0.03 96.0 6.76 3.90 ID-AE-8 990 440 207 0.47 1968.8 122.9 0.03 90.5 11.93 9.07
NM-AE-4 990 440 207 0.47 2156.0 134.6 0.03 90.0 3.29 3.02 NM-AE-8 990 440 207 0.47 2012.9 125.7 0.03 98.5 9.70 9.44 VA-AE-4 990 440 207 0.47 2111.9 131.8 0.03 67.5 6.48 4.60 VA-AE-8 990 440 207 0.47 2045.1 127.7 0.03 130 9.44 7.55 SD-AE-4 990 440 207 0.47 2121.0 132.4 0.03 91.5 6.45 4.26 SD-AE-8 990 440 207 0.47 2047.2 127.8 0.03 91.5 9.71 7.52 IA-AE-4 990 440 207 0.47 2151.4 134.3 0.03 91.5 4.92 4.92 IA-AE-8 990 440 207 0.47 2084.0 130.1 0.03 91.5 7.90 7.90
* Aggregate absorption neglected for water calculation
157
Table 7.9: Mortar Mixtures Used to Evaluate the Effect of Calcined Clay
Mixture ID
Graded Aggregate
Dry Weight
g
Cementg
H2Og
Calcined Clay
g
W/CM by
Mass
γ kg/m3
γ lb/ft3
Yield ft3 Flow
Total Air
Content%
WY-CC-17 990 365 207 75 0.47 2186.0 136.5 0.03 91.5 2.40 WY-CC-25 990 330 207 110 0.47 2219.5 138.6 0.02 65.5 0.43 ID-CC-17 990 365 207 75 0.47 2192.6 136.9 0.03 53.0 0.93 ID-CC-25 990 330 207 110 0.47 2190.7 136.8 0.02 44.0 0.55
A6NM-CC-17 990 365 207 75 0.47 2206.2 137.7 0.03 61 0.03 A6NM-CC-25 990 330 207 110 0.47 2178.6 136.0 0.02 60.5 0.82 VA-CC-17 990 365 207 75 0.47 2200.7 137.4 0.03 60 1.55 VA-CC-25 990 330 207 110 0.47 2192.6 136.9 0.02 53.5 1.45 SD-CC-17 990 365 207 75 0.47 2202.6 137.5 0.03 52.5 1.85 SD-CC-25 990 330 207 110 0.47 2196.0 137.1 0.02 54 1.68 IA-CC-25 990 365 207 75 0.47 2195.3 137.0 0.02 55 1.37 IA-CC-25 990 330 207 110 0.47 2183.1 136.3 0.02 52.0 2.07 IN-CC-25 990 330 207 110 0.47 2196.5 137.1 0.02 53.5 0.29 NV-CC-25 990 330 207 110 0.47 2191.2 136.8 0.02 55 0.24
E6-NM-CC-25 990 330 207 110 0.47 2193.4 136.9 0.02 60.5 1.41 * Aggregate absorption neglected for water calculation
158
Table 7.10: Mortar Mixtures Used to Evaluate the Effect of W/C
Mixture ID
Graded Aggregate
Dry Weight
g
Cementg
H2Og
HRWRcc
W/CM by
Mass
γ kg/m3
γ lb/ft3
Yield ft3 Flow
WY-WC-35 990 440 154 5 0.35 2321.2 144.9 0.02 1.76 WY-WC-55 990 440 242 --- 0.55 2203.1 137.5 0.03 0.06 WY-WC-65 990 440 286 --- 0.65 2100.0 131.1 0.03 1.79 ID-WC-35 990 440 154 5 0.35 2286.9 142.8 0.02 1.94 ID-WC-55 990 440 242 --- 0.55 2177.9 136.0 0.03 0.06 ID-WC-65 990 440 286 --- 0.65 2097.6 131.0 0.03 0.83
NM-WC-35 990 440 154 5 0.35 2320.5 144.9 0.02 0.19 NM-WC-55 990 440 242 --- 0.55 2169.8 135.5 0.03 0.16 NM-WC-65 990 440 286 --- 0.65 2106.2 131.5 0.03 0.17 VA-WC-35 990 440 154 5 0.35 2301.2 143.7 0.02 2.39 VA-WC-55 990 440 242 --- 0.55 2177.6 135.9 0.03 1.03 VA-WC-65 990 440 286 --- 0.65 2119.8 132.3 0.03 0.69 SD-WC-35 990 440 154 5 0.35 2276.9 142.1 0.02 3.84 SD-WC-55 990 440 242 --- 0.55 2170.5 135.5 0.03 1.73 SD-WC-65 990 440 286 --- 0.65 2103.6 131.3 0.03 1.80
* Aggregate absorption neglected for water calculation
159
Table 7.11: Mortar Mixtures Used to Count for the Absorption of Aggregates
Aggregate ID
Cement g
AggregateDry
Weight g
H2O g Flow Unit Weight kg/m3
(lb/ft3)
Total Air
Content %
A1-WY 740 1665 361 64.5 2184 (136.3) 2.86 A2-WY 740 1665 361 115 2194 (137.0) 2.29 A4-ID 740 1665 380 108.5 2143 (133.8) 2.78
A6-NM 740 1665 376 109.5 2175 (135.8) 1.18 A7-NC 740 1665 357 41.5 2258 (141.0) 2.67 A9-NE 740 1665 353 116.5 2211 (138.0) 1.75 B2-MD 740 1665 361 69 2205 (137.7) 1.79 B4-VA 740 1665 372 87 2184 (136.3) 2.52 C2-SD 740 1665 353 83.5 2205 (137.7) 2.38 D2-IL 740 1665 378 106 2202 (137.5) 2.18 E2-IA 740 1665 366 97 2182 (136.2) 2.7 E4-NV 740 1665 443 81 1988 (124.1) 1.63 E6-IN 740 1665 366 113 2216 (138.3) 1.38
E8-NM 740 1665 370 98 2200 (137.3) 1.18 Note 1: Refer to Table 5.2 for Nomenclature Note 2: Weights were calculated on a 5-bars batch basis:
160
7.3 ASTM C 1293 MIXTURE PROPORTIONS
ASTM C 1293 was used to investigate the alkali-silica reactivity of all
aggregates listed in Table 5.2. The test was also used to evaluate modification
procedures and mitigation alternatives using two highly reactive and one slowly
reactive aggregates. Table 7.12 includes the proportions and fresh concrete properties
of mixtures used to investigate the standard C 1293 at 380C, C 1293 at 600C, and C
1293 in 1N NaOH solution at 380C and 800C.
In the following tables, ASTM C 138 was used to measure the mixtures’ unit
weight, γ, yield, and total air content, whereas ASTM C 143 was used to measure the
slump.
Using the aggregates listed in Table 5.2, 0.6 ft3 concrete mixtures were prepared
to cast seven 3-in. x 3-in. x 11-in. prisms. Three prisms were stored in a closed
container over water at 380C, two prisms were stored in a 1N NaOH solution at 380C,
and two prisms were stored in a 1N NaOH solution at 800C. Smaller batches (0.2 ft3)
with the same proportions were prepared at a later date to cast concrete prisms for
performing C 1293 at 600C. Proportions for these mixtures are listed in Table 7.12.
Additional concrete mixtures, listed in Tables 7.13 to 7.20, were prepared to
investigate mitigation alternatives. All these mixtures were used to cast three 3-in. x
3-in. x 11-in. prisms that were stored in a closed container over water at 380C and six
4-in. x 8-in. concrete cylinders that were used to test for compressive strength,
modulus of elasticity, tensile strength, and rapid chloride permeability
161
Table 7.12: Concrete Mix Proportions for ASTM C 1293 and Modified C 1293
Aggregate ID
Coarse Aggregate
SSD Weight lb/yd3
Fine Aggregate
SSD Weight lb/yd3
Cementlb/yd3
Waterlb/yd3
W/CM by
Mass
γ∗
lb/ft3 Yield*
ft3 Slump**
in.
Total Air
Content*
%
A1-WY 1711 1188 710 315 0.45 143.8 0.6 4.50 1.8 A2-WY 1666 1198 710 320 0.45 143.8 0.6 4.00 0.8 A3-ID 1603 1256 710 270 0.45 143.8 0.6 4.50 2.8 A4-ID 1608 1192 710 315 0.45 145.4 0.6 4.50 1.8
A5-NM 1742 1137 710 270 0.45 145.4 0.6 4.50 2.2 A6-NM 1608 1185 710 315 0.45 145.4 0.6 4.75 1.5 A7-NC 1672 1322 710 270 0.45 148.8 0.6 3.50 2.5 A8-VA 1668 1260 710 315 0.45 147.3 0.6 3.50 1.8 A9-NE 1322 1545 710 315 0.45 147.3 0.6 4.00 2.9 A10-PA 1666 1203 710 315 0.45 147.3 0.6 3.50 1.8 B1-MD 1615 1279 710 270 0.45 147.3 0.6 4.00 1.4 B2-MD 1582 1282 710 320 0.45 141.9 0.6 2.50 1.5 B4-VA 1613 1248 710 270 0.45 147.3 0.6 4.00 1.8 C1-SD 1591 1296 710 270 0.45 145.5 0.6 4.25 2.4 C2-SD 1608 1262 710 320 0.45 145.4 0.6 2.50 1.9 D2-IL 1613 1278 710 320 0.45 143.8 0.6 3.75 2.4 E2-IA 1666 1198 710 320 0.45 142.6 0.6 4.00 2.5 E3-NV 1405 1284 710 334 0.45 138.4 0.6 4.25 1.1 E4-NV 1639 1058 710 320 0.45 138.4 0.6 4.00 2.0 E6-IN 1666 1203 710 320 0.45 144.0 0.6 4.50 1.9
E7-NM 1512 1402 710 315 0.45 148.8 0.6 4.50 1.3 E8-NM 1586 1265 710 320 0.45 144.0 0.6 3.00 1.6
* = ASTM C 138 to measure unit weight, γ, yield, and total air content ** = ASTM C 143 to measure the Slump
W/C = Water-to-Cement Ratio by weight γ = Concrete Unit Weight
162
Table 7.13: Concrete Mixtures Used to Investigate the Effect of Air Entrainment
Mixture ID
Control Air
Content %
Coarse Aggregate
SSD Weight lb/yd3
Fine Aggregate
SSD Weight lb/yd3
Cementlb/yd3
Waterlb/yd3
W/C by
Mass
γ∗
lb/ft3 Yield*
ft3 Slump**
in.
EntrainedAir
Content* %
WY-2 0.8 1666 1198 710 360 0.45 140.4 0.6 4.25 2.4 WY-4 0.8 1666 1198 710 360 0.45 137.0 0.6 4.50 4.7 WY-6 0.8 1666 1198 710 360 0.45 133.6 0.6 5.00 7.1 WY-8 0.8 1666 1198 710 360 0.45 130.1 0.6 7.00 9.5 ID-2 1.8 1608 1192 710 315 0.45 140.4 0.6 4.50 2.3 ID-4 1.8 1608 1192 710 315 0.45 137.0 0.6 6.00 4.7 ID-6 1.8 1608 1192 710 315 0.45 133.6 0.6 6.00 7.0 ID-8 1.8 1608 1192 710 315 0.45 130.1 0.6 7.00 9.3
NM-2 1.5 1608 1185 710 315 0.45 140.4 0.6 5.00 2.4 NM-6 1.5 1608 1185 710 315 0.45 137.0 0.6 5.25 4.7 NM-8 1.5 1608 1185 710 315 0.45 133.6 0.6 6.00 7.1
NM-10 1.5 1608 1185 710 315 0.45 130.1 0.6 6.50 9.4 SD-4 1.9 1608 1262 710 337 0.45 140.4 0.6 4.00 2.4 SD-8 1.9 1608 1262 710 337 0.45 133.6 0.6 6.00 7.1 IA-4 2.5 1666 1198 710 320 0.45 137.0 0.6 4.00 3.9 IA-8 2.5 1666 1198 710 320 0.45 133.6 0.6 6.00 6.3
* = ASTM C 138 to measure unit weight, γ, yield, and total air content ** = ASTM C 143 to measure the Slump W/C = Water-to-Cement Ratio γ = Concrete Unit Weight Control Air = Total air of concrete with no admixture (Table 7.12)
Entrained air = Total Air obtained by adding Entraining Agent – Control Air
163
Table 7.14: Concrete Mixtures Used to Investigate the Effect of Silica Fume
Mixture ID
Coarse Aggregate
SSD Weight lb/yd3
Fine Aggregate
SSD Weight lb/yd3
Cementlb/yd3
Waterlb/yd3
Silica Fumelb/yd3
W/CM by
Mass
γ∗
lb/ft3 Yield*
ft3 Slump**
in.
Total Air
Content*
%
WYSF- 5 1666 1198 675 360 36 0.45 143.8 0.6 4.50a 0.8
WYSF-10 1666 1198 630 360 71 0.45 143.8 0.6 5.50b 0.8
ID-SF- 5 1608 1192 675 315 36 0.45 143.8 0.6 3.50a 1.8
ID-SF-10 1608 1192 630 315 71 0.45 143.8 0.6 3.00b 1.8
SD-SF-5 1608 1262 675 337 36 0.45 143.8 0.6 1.25a 1.9 SD-SF-
10 1608 1262 630 337 71 0.45 143.8 0.6 3.00b 1.9
IA-SF- 5 1666 1198 675 337 36 0.45 143.8 0.6 1.50a 1.80
IA-SF-10 1666 1198 630 337 71 0.45 143.8 0.6 3.50b 1.80
* = ASTM C 138 to measure unit weight, γ, yield, and total air content ** = ASTM C 143 to measure the Slump
γ = Concrete Unit Weight W/CM = Water-to-Cementitious-Materials Ratio a = Slump after adding 20cc of Superplasticizer b = Slump after adding 60cc of Superplasticizer
164
Table 7.15: Concrete Mixtures Used to Investigate the Effect of Class C Fly Ash
Mixture ID
Coarse Aggregate
SSD Weight lb/yd3
Fine Aggregate
SSD Weight lb/yd3
Cementlb/yd3
Waterlb/yd3
Class C Fly Ash
lb/yd3
W/CM by
Mass
γ∗
lb/ft3 Yield*
ft3 Slump**
in.
Total Air
Content*
%
WY-FAC-20 1666 1198 568 360 142 0.45 143.2 0.6 4.50 0.8
WY-FAC-27.5
1666 1198 515 360 195 0.45 143.2 0.6 5.00 0.5
WY-FAC-35 1666 1198 462 360 249 0.45 142.5 0.6 4.75 0.9
ID- FAC-20 1608 1192 568 315 142 0.45 143.2 0.6 3.00 1.7
ID- FAC-27.5
1608 1192 515 315 195 0.45 143.2 0.6 3.50 1.5
ID- FAC-35 1608 1192 462 315 249 0.45 142.5 0.6 3.75 1.8
SD- FAC-20 1608 1262 568 337 142 0.45 143.2 0.6 3.00 1.8
SD- FAC-27.5
1608 1262 515 337 195 0.45 143.2 0.6 4.00 1.6
SD- FAC-35 1608 1262 462 337 249 0.45 142.5 0.6 5.00 1.9
IA- FAC-20 1666 1198 568 360 142 0.45 143.2 0.6 3.00 1.73
IA- FAC-27.5
1666 1198 515 360 195 0.45 143.2 0.6 4.00 1.52
IA- FAC-35 1666 1198 462 360 249 0.45 142.5 0.6 5.00 1.83
* = ASTM C 138 to measure unit weight, γ, yield, and total air content ** = ASTM C 143 to measure the Slump
γ = Concrete Unit Weight W/CM = Water-to-Cementitious Materials Ratio
165
Table 7.16: Concrete Mixtures Used to Investigate the Effect of Class F Fly Ash
Mixture ID
Coarse Aggregate
SSD Weight lb/yd3
Fine Aggregate
SSD Weight lb/yd3
Cementlb/yd3
Waterlb/yd3
Class F Fly Ash
lb/yd3
W/CM by
Mass
γ∗
lb/ft3 Yield*
ft3 Slump**
in.
Total Air
Content*
%
WY-FAF-15 1666 1198 604 360 107 0.45 143.2 0.6 4.50 0.6
WY-FAF-25 1666 1198 533 360 178 0.45 142.5 0.6 5.00 0.7
ID-FAF-15 1608 1192 604 315 107 0.45 143.2 0.6 3.00 1.6
ID-FAF-25 1608 1192 533 315 178 0.45 142.5 0.6 3.50 1.7
SD-FAF-15 1608 1262 604 337 107 0.45 143.2 0.6 3.00 1.7
SD-FAF-25 1608 1262 533 337 178 0.45 142.5 0.6 4.00 1.8
IA-FAF-15 1666 1198 604 337 107 0.45 143.2 0.6 3.00 1.61
IA-FAF-25 1666 1198 533 337 178 0.45 142.5 0.6 4.00 1.70
* = ASTM C 138 to measure unit weight, γ, yield, and total air content ** = ASTM C 143 to measure the Slump
γ = Concrete Unit Weight W/CM = Water-to-Cementitious Materials Ratio
166
Table 7.17: Concrete Mixtures Used to Investigate the Effect of Granulated Slag
Mixture ID
Coarse Aggregate
SSD Weight lb/yd3
Fine Aggregate
SSD Weight lb/yd3
Cementlb/yd3
Waterlb/yd3
Slaglb/yd3
W/CM by
Mass
γ∗
lb/ft3 Yield*
ft3 Slump**
in.
Total Air
Content*
%
WY-SL-25 1666 1198 533 360 178 0.45 143.2 0.6 4.50 0.6
WY-SL-50 1666 1198 355 360 355 0.45 141.8 0.6 5.00 0.9
WY-SL-70 1666 1198 213 360 497 0.45 141.1 0.6 4.75a 0.9
ID-SL-25 1608 1192 533 315 178 0.45 143.2 0.6 3.00 1.8
ID-SL-50 1608 1192 355 315 355 0.45 143.2 0.6 3.50 1.9
ID-SL-70 1608 1192 213 315 497 0.45 143.8 0.6 3.75a 1.6
SD-SL-25 1608 1262 533 337 178 0.45 143.2 0.6 3.00 1.9
SD-SL-50 1608 1262 355 337 355 0.45 143.8 0.6 4.00 1.6
SD-SL-70 1608 1262 213 337 497 0.45 143.8 0.6 5.00a 1.7
IA-SL-25 1666 1198 533 337 178 0.45 143.2 0.6 3.25 1.82
IA-SL-50 1666 1198 355 337 355 0.45 143.8 0.6 3.75 1.49
IA-SL-70 1666 1198 213 337 497 0.45 143.8 0.6 5.50a 1.59
* = ASTM C 138 to measure unit weight, γ, yield, and total air content ** = ASTM C 143 to measure the Slump
γ = Concrete Unit Weight W/CM = Water-to-Cementitious Materials Ratio
a = Slump after adding 10 to 30 cc Superplasticizers
167
Table 7.18: Concrete Mixtures Used to Investigate the Effect of Calcined Clay
Mixture ID
Coarse Aggregate
SSD Weight lb/yd3
Fine Aggregate
SSD Weight lb/yd3
Cementlb/yd3
Waterlb/yd3
Calcined Clay lb/yd3
W/CM by
Mass
γ∗
lb/ft3 Yield*
ft3 Slump**
in.
Total Air
Content*
%
WY-CC-17 1666 1198 589 360 121 0.45 143.2 0.6 4.50 0.6
WY-CC-25 1666 1198 533 360 178 0.45 142.5 0.6 5.00 0.7
ID- CC-17 1608 1192 589 315 121 0.45 143.2 0.6 3.00 1.5
ID- CC-25 1608 1192 533 315 178 0.45 142.5 0.6 3.50 1.7
SD- CC-A7 1608 1262 589 337 121 0.45 143.2 0.6 3.00 1.7
SD- CC-25 1608 1262 533 337 178 0.45 142.5 0.6 4.00 1.8
IA- CC-A7 1666 1198 589 337 121 0.45 143.2 0.6 2.75 1.55
IA- CC-25 1666 1198 533 337 178 0.45 142.5 0.6 3.50 1.70
* = ASTM C 138 to measure unit weight, γ, yield, and total air content ** = ASTM C 143 to measure the Slump
γ = Concrete Unit Weight W/CM = Water-to-Cementitious Materials Ratio
168
Table 7.19: Concrete Mixtures Used to Investigate the Effect of Lithium Nitrate
Mixture ID
Coarse Aggregate
SSD Weight lb/yd3
Fine Aggregate
SSD Weight lb/yd3
Cementlb/yd3
Waterlb/yd3
LiNO3lb/yd3
W/CM by
Mass
γ∗
lb/ft3 Yield*
ft3 Slump**
in.
Total Air
Content*
%
WY-LI-315 1666 1198 710 337 31 0.45 143.8 0.6 4.50 0.8
WY-LI-495 1666 1198 710 326 49 0.45 143.8 0.6 5.00 0.8
WY-LI-900 1666 1198 710 292 89 0.45 143.8 0.6 4.75 1.0
ID-LI-315 1608 1192 710 292 31 0.45 143.8 0.6 3.00 1.8
ID-LI-495 1608 1192 710 281 49 0.45 143.8 0.6 3.50 1.7
ID-LI-900 1608 1192 710 247 89 0.45 143.8 0.6 3.75 1.9
SD-LI-315 1608 1262 710 315 31 0.45 143.8 0.6 3.00 1.9
SD-LI-495 1608 1262 710 304 49 0.45 143.8 0.6 4.00 1.9
SD-LI-900 1608 1262 710 270 89 0.45 143.8 0.6 5.00 2.0
IA-LI-315 1666 1198 710 315 31 0.45 143.8 0.6 2.75 1.81
IA-LI-495 1666 1198 710 304 49 0.45 143.8 0.6 3.75 1.76
IA-LI-900 1666 1198 710 270 89 0.45 143.8 0.6 4.50 1.93
* = ASTM C 138 to measure unit weight, γ, yield, and total air content ** = ASTM C 143 to measure the Slump
γ = Concrete Unit Weight W/CM = Water-to-Cementitious Materials Ratio
169
CHAPTER EIGHT
MISCELLANEOUS TESTING RESULTS
8.1 INTRODUCTION
This chapter includes information about the aggregates investigated obtained
either by performing tests or reported by others. Information includes physical
properties, summarized results of petrographic examination, field performance status,
and any C 1260 and C 1293 results reported by aggregate producers.
8.2 PHYSICAL PROPERTY TESTS RESULTS
After performing the tests listed in Table 6.1, physical properties of the
aggregates investigated were determined. Table 8.1 lists the measured and calculated
properties for the aggregates listed in Table 5.2.
8.3 PETROGRAPHIC EXAMINATION, CHEMICAL ANALYSIS AND FIELD PERFORMANCE DOCUMENTATION
Table 8.2 includes the chemical analysis results for the aggregates. This analysis
was submitted as part of the petrographic analysis report for each aggregate. Table
8.3 includes the following:
1. Petrographic examination results, whether the aggregates contain reactive
materials or not. This information was obtained from petrographic analysis
reports that were submitted by either aggregate producers or departments of
transportation using the aggregates. Detailed information can be found in
Appendix D.
2. Field performance status of aggregates. This information was obtained by getting
input from aggregate producers and departments of transportation with
experienced using these aggregates. Detailed information can be found in
Appendix D.
170
3. ASTM C 227, C 1260, and C 1293 results that were submitted by aggregate
producers.
Table 8.1: Physical Properties of Aggregates Investigated Dry Apparent SSD Abs. DRUW γssd Void Fineness
Agg. Agg. B.S.G. B.S.G. B.S.G. % lb/ft3 lb/ft3 Content, % ModulusID Type Note1 Note1 Note1 Note1 Note2 Note2 Note2 Note3
A1-WY C.A. 2.62 2.67 2.64 0.77 99.8 100.6 39 N/A A2-WY F.A. 2.61 2.66 2.63 0.80 95.7 96.5 41 2.7 A3-ID C.A. 2.52 2.65 2.57 1.9 101.5 103.4 36 N/A A4-ID F.A. 2.52 2.65 2.57 1.90 92.5 94.3 41 2.8
A5-NM C.A. 2.57 2.67 2.61 1.50 100.9 102.4 37 N/A A6-NM F.A. 2.51 2.63 2.56 1.70 100.8 102.5 36 2.92 A7-NC C.A. 2.76 2.81 2.79 0.53 97.8 98.3 43 N/A A8-VA C.A. 2.59 2.65 2.62 1.07 100.2 101.3 38 N/A A9-NE S&G 2.62 2.64 2.62 0.30 116.7 117.1 29 3.8 A10-PA F.A. 2.63 2.69 2.64 1.10 117.5 118.4 30 2.6 B1-MD C.A. 2.79 2.83 2.81 0.50 102.0 102.5 41 N/A B2-MD F.A. 2.60 2.65 2.63 0.78 97.3 98.0 40 3.6 B4-VA F.A. 2.59 2.65 2.62 0.80 100.8 101.1 40 2.9 C1-SD C.A. 2.59 2.65 2.61 0.84 95.8 96.6 41 N/A C2-SD F.A. 2.63 2.65 2.64 0.30 101.4 101.7 38 2.9 D1-IL C.A. 2.63 2.76 2.67 1.81 97.7 99.5 40 N/A D2-IL F.A. 2.64 2.71 2.68 1.80 101.5 103.3 38 2.9 D3-TX C.A. 2.49 2.56 2.56 2.85 95.2 97.9 39 N/A E2-Ia F.A. 2.63 2.63 2.63 1.10 100.2 101.3 39 2.675
E3-NV F.A. 2.15 2.28 2.27 5.70 78.6 83.1 41 2.75 E4-NV C.A. 2.19 2.29 2.29 4.80 81.4 85.3 40 N/A E6-IN F.A. 2.61 2.69 2.64 1.10 106.8 108.0 34 2.79
E7-NM C.A. 2.63 2.70 2.66 0.90 91.0 91.8 45 N/A E8-NM F.A. 2.57 2.66 2.60 1.30 100.8 102.1 37 3.02
Agg. = Aggregate; B.S.G. = Bulk specific gravity; Abs. = Absorption; γssd = SSD unit weight;
DRUW = Dry rodded unit weight = γd; N/A = Not applicable C.A. = Coarse aggregate; F.A. = Fine aggregate Note1: ASTM C 127 for coarse aggregates and ASTM C 128 for fine aggregates Note2: ASTM C 29 Note3: ASTM C 136
171
Table 8.2: Chemical Analysis of Aggregates Agg. CaO
% MgO
% Fe2O3
% Na2O
% K2O%
MnO%
TiO2%
SiO2 %
Al2O3 %
Loss on Ignition
A-WY 2.30 0.54 6.77 2.36 2.67 0.10 0.77 74.62 10.43 1.41 A-ID 2.47 1.15 3.72 2.78 3.31 0.09 0.74 74.02 10.96 1.57
A-NM 1.44 0.57 2.93 1.80 2.60 0.05 0.43 80.65 8.12 1.04 A-NC 1.42 1.98 7.18 2.09 3.84 0.16 0.87 62.68 15.70 3.77
A,B-VA 0.55 0.40 3.23 0.63 2.18 0.09 2.13 84.50 4.01 1.51 A-NE 0.80 0.12 0.45 1.38 2.45 0.01 0.11 88.14 6.05 0.37 B-MD 5.47 5.74 8.92 4.03 0.60 0.21 0.54 59.04 13.23 1.62 C-SD 0.34 0.13 0.13 0.21 0.08 0.01 0.05 97.98 0.59 0.14 D-IL 29.91 20.52 0.29 0.00 0.00 0.02 0.01 0.56 0.45 50.19 E-IA 4.51 1.25 3.03 1.40 1.40 0.07 0.34 78.30 5.88 3.83 E-NV 0.88 0.37 1.17 3.30 3.82 0.09 0.14 74.02 12.55 3.18 E-IN 5.82 1.52 1.77 0.99 1.48 0.04 0.25 77.12 4.35 5.80
E-NM 4.01 0.37 7.41 1.16 1.76 0.13 0.77 75.73 5.35 3.28 This analysis was provided as part of the petrographic analysis report
172
Table 8.3: Summary of Available Documentation on Aggregates Investigated
Aggregate ID
Petrographic Analysis
Reported
Field Performance
ASTM C 1260 (14-Day
Expansion)
ASTM C 1293 (1-Year
Expansion)
ASTM C227
(6-Month Expansion)
A(1,2)-WY Reactive Materials
Reactive N.R. N.R. N.R.
A(3,2)-ID Reactive Materials
Reactive Reactive (0.80 %)
N.R. N.R.
A(5,6)-NM Reactive Materials
Reactive Reactive (1.040 %)
N.R. N.R.
A7-NC Reactive Materials
Reactive N.R. N.R. Reactive
A8-VA No Reactive Materials
N.R. N.R. N.R. N.R.
A9-NE Reactive Materials
Reactive Reactive (0.29 %)
N.R. Innocuous (0.03%)
A10-PA Reactive Materials
Reactive Reactive (0.314 %)
N.R. N.R.
B(1,2)-MD No Reactive Materials
Reactive Inconclusive (0.11 %)
N.R. N.R.
B4-VA No Reactive Materials
N.R. N.R. N.R. N.R.
C(1,2)-SD No Reactive Materials
Reactive N.R. N.R. N.R.
D(1,2)-IL No Reactive Materials
Good with high alkali
cement
N.R. N.R. N.R.
E2-Ia No Reactive Materials
Good with high alkali
cement
Reactive (0.33 %)
N.R. Innocuous (0.03 %)
E(3,4)-NV Reactive Materials
Good with mitigation
N.R. N.R. N.R.
E6-IN No Reactive Materials
Good with high alkali
cement
N.R. N.R. N.R.
E(7,8)-NM Reactive Materials
Good with mitigation
Reactive (0.34 %)
N.R. N.R.
Note1: Refer to Table 5.2 for aggregate notation Note2: Detailed information about properties of aggregates in this table can be
found in Appendix D. N.R. = No Record
173
8.4 ASTM C 227 RESULTS OF TESTING PERFORMED AS PART OF THIS STUDY
ASTM C 227 procedures were followed with the following exceptions:
1. The cement used had an average alkali content of 1.14% Na2Oequiv.
2. No wicks were used around the sides of the containers.
3. Mixture proportions were controlled by a constant water-cement ratio of 0.47
instead of a constant flow.
4. Expansions were monitored for up to 1-year.
Results of the testing procedures are illustrated in Table 8.4 and Figures 8.1
through 8.3. Mixture proportions used for this test are listed in Table 7.1, which
includes the mixture properties unit weight, flow number, yield and air content.
Table 8.4: ASTM C 227 Expansion Results for Aggregates Investigated Expansion, % Agg.
ID 14-day 1-month 2-month 3-month 4-month 6-month 9-month 12-monthA1-WY 0.01 0.04 0.06 0.08 0.11 0.14 0.20 0.21 A2-WY 0.01 0.02 0.08 0.13 0.15 0.20 0.23 0.24 A4-ID 0.01 0.05 0.19 0.30 0.37 0.51 0.63 0.69
A6-NM 0.00 0.05 0.21 0.31 0.39 0.49 0.60 0.61 A7-NC 0.00 0.01 0.03 0.07 0.10 0.68 0.74 0.75 A9-NE 0.01 0.01 0.02 0.03 0.04 0.05 0.06 0.07 A10-PA 0.01 0.02 0.02 0.03 0.03 0.04 0.06 0.08 B2-MD 0.01 0.01 0.02 0.03 0.03 0.04 0.06 0.06 B4-VA 0.01 0.02 0.02 0.03 0.04 0.05 0.06 0.07 C2-SD 0.01 0.01 0.02 0.03 0.04 0.06 0.08 0.10 D2-IL 0.00 0.00 0.01 0.02 0.02 0.03 0.04 0.04 E2-IA 0.00 0.00 0.00 0.02 0.02 0.03 0.04 0.04 E4-NV 0.00 0.01 0.02 0.05 0.07 0.09 0.13 0.14 E6-IN 0.00 0.01 0.02 0.04 0.05 0.07 0.08 0.08
E8-NM 0.00 0.01 0.07 0.16 0.21 0.33 0.41 0.43
174
0.000.050.100.150.200.250.300.350.400.450.500.550.600.650.700.75
0 1 2 3 4 5 6 7 8 9 10 11 12 13
Time, months
Exp
ansi
on, %
A1-WYA2-WYA4-IDA6-NMA7-NCA9-NEA10-PA
0.00
0.02
0.04
0.06
0.08
0.10
0.12
0 1 2 3 4 5 6 7 8 9 10 11 12 13
Time, months
Exp
ansi
on, %
B2-MDB4-VAC2-SDD2-IL
Figure 8.1: ASTM C 227 Results for Category A Aggregates
Figure 8.2: ASTM C 227 Results of Category B, C, & D Aggregates
175
-0.050.000.050.100.150.200.250.300.350.400.45
0 1 2 3 4 5 6 7 8 9 10 11 12 13
Time, months
Exp
ansi
on, %
E2-IAE4-NVE6-INE8-NM
This test has been heavily criticized in the literature; the major complaint is that it
does not provide for the correct prediction of the alkali-silica reactivity of several
aggregate types, namely, slowly reactive aggregates. The standard limit criteria for
the interpretation of the testing results are:
1. Expansions are considered excessive if they exceed 0.05% at 3 months or 0.10%
at 6 months.
2. Expansions greater than 0.05% at 3 months should not be considered excessive if
the 6-month expansions are less than 0.10%.
3. Data for the 3-month test should be considered only when the 6-month results are
not available.
4. Other researchers suggested using a value of 0.10% at 12-months as a criterion
for reactivity.
These criteria were used to generate the following observations:
Figure 8.3: ASTM C 227 Results for Category E Aggregates
176
1. Category A: Aggregates in this category have been identified as being alkali-
silica reactive in field applications (Table 8.3) and have been identified as
reactive using C 1260 and C 1293 (Chapters 9). Using the C 227 results these
aggregates have shown 3-month expansions higher than 0.05% with the
exception of A9-NE and A10-PA (Figure 8.1). In addition, A9-NE and A10-PA
had 6-month and 12-month expansions lower than 0.10%. Thus, using the results
of this test, A9-NE and A10-PA are considered innocuous aggregates, which
does not correlate with the field performance of these aggregates nor does it
correlate with the results of C 1260 and C 1293 generated in this study.
2. Category B and C: Aggregates in these categories have been identified as slowly
reactive aggregates using C 1260 and C 1293 (Chapter 9, and 10) and some have
been identified as being alkali-silica reactive in field applications (Table 8.3). All
three aggregates showed 3-month expansions lower than 0.05% and 6-months
and 12-month expansions lower than 0.10%. Thus, based on the C 227 results
these aggregates are considered innocuous; these results do not correlate with the
results of C 1260, C 1293 or the field performance record.
3. Category D: The aggregate in this category has been identified as being
innocuous in field applications (Table 8.3) and innocuous using C 1260 and C
1293 (Chapters 9 and 10). The C 227 results indicated that this aggregate is
innocuous with a 3-month expansion lower than 0.05 and 6-month and 12-month
expansions lower than 0.10%.
4. Category E: Aggregates in this category have been identified as being innocuous
in field applications (Table 8.3) with the exception of E4-NV, which has been
reported as a reactive aggregate. E4-NV had a 3-month expansion slightly higher
than 0.05% and a 12-month expansion higher than 0.10%. Thus, E4-NV is
correctly classified as reactive. According to these results, E8-NM is also
reactive. The other two aggregates (E2-IA and E4-IN) have shown innocuous
177
expansions and are classified as such. This classification correlates well with the
field performance of these aggregates.
In summary, the C 227 results were not very reliable and several discrepancies
were noted. The procedures failed to predict the potential reactivity of all slowly
reactive aggregates and two reactive aggregates. These facts, coupled with the
criticism about the test in the literature, generated the conclusion that the ASTM C
227 testing procedures are not reliable and should not be used to predict the potential
alkali-silica reactivity of aggregates. It should be noted that an aggregate or an
aggregate-cement combination that fails this test is probably reactive and should be
rejected or mitigated.
178
CHAPTER NINE
ASTM C 1260 RESULTS AND DISCUSSION
“TEST METHOD FOR POTENTIAL REACTIVITY OF AGGREGATES (MORTAR-BAR TEST)”
9.1 ASTM C 1260
ASTM C 1260 is used to test for the potential alkali-silica reactivity of aggregates
within two weeks. Aggregates are separated into specified sieve sizes, combined
using specified amounts of each sieve size, and mixed with cement to make
1”x1”x11” mortar bars. After 24-hours of moist curing, mortar bars are stored for an
additional 24 hours in water maintained at 800C after which the bars are stored in a
1N NaOH solution maintained at 800C. Expansion readings are taken at 4, 7, 11, and
14 days of storage in the NaOH solution. Fourteen-day expansions higher than
0.20% are considered reactive, 14-day expansions lower than 0.10% are considered
innocuous, and 14-day expansions between 0.10% and 0.20% are considered
inconclusive. Aggregates were tested using these procedures described in details in
section 6.3.2, and the results are shown in this chapter. Table 9.1 includes a summary
of expansion readings for the aggregates and Figures 9.1 through 9.3 illustrate the
expansions in a graphical form. Mixture proportions for these tests were included in
Table 7.2.
179
Table 9.1: ASTM C 1260 Expansion Test Results Aggregate Expansion, %
ID 4-day 7-day 11-day 14-day 21-day 28-day A1-WY 0.12 0.18 0.21 0.24 0.31 0.32 A2-WY 0.18 0.24 0.27 0.29 0.34 0.37 A4-ID* 0.45 0.62 0.75 0.79 0.89 0.95 A6-NM 0.50 0.67 0.83 0.91 1.04 1.12 A7-NC* 0.13 0.23 0.28 0.31 0.39 0.48 A9-NE* 0.07 0.14 0.23 0.28 0.39 0.43 A10-PA* 0.02 0.07 0.19 0.26 0.40 0.49 B2-MD* 0.04 0.07 0.09 0.11 0.16 0.18 B4-VA* 0.02 0.06 0.11 0.15 0.25 0.28 C2-SD 0.05 0.10 0.14 0.17 0.24 0.30 D2-IL* 0.01 0.01 0.02 0.02 0.03 0.03 E4-NV 0.04 0.06 0.18 0.25 0.44 0.64 E6-IN* 0.03 0.10 0.20 0.25 0.34 0.43 E2-IA 0.12 0.24 0.38 0.42 0.53 0.62
E8-NM 0.10 0.22 0.33 0.36 0.46 0.54 * = The test was performed twice and the expansions shown
are the average of two tests. Note: Expansions were the average of three prisms for each aggregate
180
0.00
0.05
0.10
0.15
0.20
0.25
0.30
0.35
0 5 10 15 20 25 30
Curing Days
Exp
ansi
on, % B2-MD*
B4-VA*C2-SDD2-IL*
0.00
0.20
0.40
0.60
0.80
1.00
1.20
0 5 10 15 20 25 30
Curing Days
Exp
ansi
on, %
A1-WYA2-WYA4-ID*A6-NMA7-NC*A9-NE*A10-PA*
Figure 9.1: ASTM C 1260 Expansions for Category A Aggregates
Figure 9.2: ASTM C 1260 Expansions for Category B, C, & D Aggregates
181
0.00
0.10
0.20
0.30
0.40
0.50
0.60
0.70
0 5 10 15 20 25 30
Curing Days
Exp
ansi
on, % E4-NV
E6-IN*E2-IAE8-NM
Criteria proposed in the standard ASTM C 1260 document to determine the
reactivity of aggregates are as follows: 14-day expansions lower than 0.10% are
considered innocuous, 14-day expansions between 0.10% and 0.20% are considered
inconclusive, and 14-day expansions greater than 0.20% are considered reactive.
Based on the results of the study conducted by Starks (1993) in the Strategic
Highway Research Program (SHRP C-343) (details in Chapter 4), it was concluded
that aggregates showing 14-day expansions higher than 0.08% are considered
reactive and 14-day expansions lower than 0.08% are considered innocuous.
However, this conclusion was based on a limited amount of data (one aggregate), and
the 0.10% has been adequately justified in the literature for a voluminous amount of
aggregates. As a result, the 0.10% criterion was adopted throughout this study for the
interpretation of the ASTM C 1260 results.
Figure 9.3: ASTM C 1260 Expansions for Category E Aggregates
182
Aggregates listed in Category A are highly reactive and have shown 14-day
expansions varying between 0.24 and 0.91%, all larger than 0.20%. Aggregates
listed in Category B and C are slowly reactive and have shown 14-day expansions
varying between 0.12 and 0.17%. Aggregates listed in Category D are innocuous
and have shown 14-day expansions varying between 0.03 and 0.06%. Category E
aggregates have shown 14-day expansions varying between 0.25 and 0.42% all larger
than 0.20%, which imply that all Category E aggregates are reactive. Petrographic
analysis and field performance of E2-IA and E6-IN indicate that the aggregates are
not reactive (Table 8.3) and this was reinforced by the results of ASTM C 1293
presented in Chapter 10 that showed that these aggregates are innocuous after 1-year
of testing. Given these discrepancies, it can be concluded that the ASTM C 1260
results were too severe for E2-IA and E6-IN. On the other hand, petrographic
analysis concluded that E4-NV and E8-NM were found to contain reactive materials
(Table 8.3), which means that the aggregates are expected to have 14-day expansions
larger than 0.20% and should be listed as Category A aggregates.
Using the 14-day expansion criterion of 0.10%, it was possible to efficiently
detect highly reactive aggregates that showed 14-day expansions higher than 0.20%.
The test was also particularly useful in detecting slowly reactive aggregates that
showed expansions between 0.10% and 0.20%. Thus, 14-day expansions between
0.10% and 0.20% should not be considered inconclusive but should be considered
slowly reactive. The power of these procedures lies in being able to detect reactive
aggregates, which was demonstrated by the correct classification of E4-NV and E8-
NM. Even though the aggregates were erroneously listed as being innocuous, the test
allowed the correct assessment of their reactivity.
The procedures however, were found to be too severe for E2-IA and E6-IN which
have been reported to have good field performance (Table 8.3), good petrographic
analysis results (Table 8.3), and innocuous when tested according to C 1293 results
(Chapter 10) but were found to be reactive when tested with C 1260.
183
9.2 ASTM C 1260 PERFORMED BY THE NATIONAL AGGREGATES ASSOCIATION (NAA)
In order to test the accuracy of the C 1260 testing procedures, three aggregates,
used in this study, were tested by the NAA. The aggregates were A2-WY, A4-ID,
and C2-SD (Table 5.2). The same cement used in this study was used by the NAA.
The C 1260 expansions for these aggregates were reported as shown in Table 9.2.
Table 9.2: ASTM C 1260 Performed by NAA Expansion, % Aggregate
ID 3-day 7-day 11-day 14-day A2-WY 0.19 0.22 0.26 0.27 A4-ID 0.43 0.58 0.68 0.73 C2-SD 0.06 0.11 0.16 0.20
A comparison between the NAA results and the results generated in this study is
included in Tables 9.3 and 9.4.
Table 9.3: Differences Between NAA Results and
Results Generated in this Study A2-WY A4-ID C2-SD
4-Day + 5.0% - 5.0% + 17.0% 7-Day 0.0% 6.5% + 8.0% 11-Day - 6.0% - 9.0% + 19.0% 14-Day - 5.0% - 8.0% + 12.0%
Positive = percentage the NAA result is larger than the one generated in this study Negative = percentage the NAA result is smaller than the one generated in this study
An inter-laboratory study evaluating the variation of C 1260 resulted in the
following conclusion (section 4.5.1.3.1): “For mortars giving average expansions
after 14 days in solution of more than 0.30%, the muti-laboratory coefficient of
variation has been found to be 14.9%. Therefore, the results of two properly
conducted tests in different laboratories on specimens of a sample of aggregate
184
should not differ by more than 42% of the mean expansion.” (Rogers 1996) Table
12.2 shows the variation from the mean of all readings. It can be seen from that table
that the variations between the results of both labs are small and the results can be
considered accurate. This was done to measure the accuracy of the testing being
performed for this study and the results show that testing was conducted properly.
Table 9.4: Variations from the Mean of the NAA and the C 1260 Results
Generated Through this Study 4-Day 7-Day 11-Day 14-Day A2-WY
NAA, expansion, % 0.19 0.22 0.26 0.274 UT, Expansion, % 0.18 0.24 0.27 0.29
Mean 0.19 0.23 0.27 0.28 NAA Variation 2.0% 4.0% 3.0% 2.7% UT Variation 2.0% 4.0% 3.0% 2.7%
A4-ID NAA, expansion, % 0.43 0.58 0.68 0.73 UT, Expansion, % 0.45 0.62 0.75 0.79
Mean 0.44 0.60 0.72 0.76 NAA Variation 3.0% 3.5% 5.0% 4.0% UT Variation 3.0% 3.5% 5.0% 4.0%
C2-SD NAA, expansion, % 0.06 0.11 0.16 0.20 UT, Expansion, % 0.05 0.10 0.14 0.17
Mean 0.06 0.10 0.15 0.18 NAA Variation 7.0% 4.0% 8.0% 6.0% UT Variation 8.0% 4.0% 10.0% 6.0%
185
9.3 MODIFIED C 1260: EXPANSIONS UP TO 56-DAYS
Selected aggregates were retested using the C 1260 procedures but expansions
were recorded over 56 days in order to investigate the possibility of a better
interpretation of the results. Mixture proportions for these procedures were the same
as before and are listed in Table 7.2 which also includes mixture properties such as
yield, unit weight, air content, and flow number. Expansions are shown in Table 9.5
and Figures 9.5 through 9.7.
Roger (1993) suggested expanding the C 1260 readings to 56 days instead of 14
and using the following criteria for assessing the reactivity of aggregates: 0.15% at
14 days, 0.33% at 28 days, and 0.48% at 56 days. Thus, for an aggregate to be
classified as reactive, it should exceed all three criteria. A study conducted in
Australia (Shayan, 1992) concluded that these criteria were not effective in detecting
the reactivity of several slowly reactive aggregates. These procedures were used to
determine whether Category E aggregates could be accurately classified using these
limits and whether these limits are effective with slowly reactive aggregates. That is
why only two Category A aggregates were tested while all Category B, C, D, and E
were investigated.
Table 9.5: Expansions up to 56 days in 1N NaOH Curing Solution Expansion, %
Aggregate 4-day 7-day 11-day 14-day 21-day 28-day 42-day 56-dayA1-WY 0.06 0.16 0.21 0.24 0.30 0.35 0.42 0.48 A9-NE 0.04 0.10 0.17 0.21 0.30 0.37 0.47 0.56 B4-VA 0.01 0.04 0.08 0.12 0.19 0.26 0.37 0.46 C2-SD 0.02 0.07 0.10 0.13 0.20 0.26 0.38 0.48 D2-IL 0.01 0.01 0.02 0.02 0.03 0.03 0.04 0.05 E2-IA 0.10 0.28 0.41 0.47 0.56 0.65 0.77 0.85 E4-NV 0.04 0.11 0.21 0.30 0.47 0.66 0.99 1.35 E6-IN 0.02 0.09 0.18 0.23 0.34 0.43 0.56 0.67
E8-NM 0.09 0.26 0.35 0.40 0.46 0.53 0.63 0.71
186
A comparison between the 14-day expansions generated for the 56-day
procedures were compared to the 14-day expansions generated earlier using ASTM
C 1260 is shown in Figure 9.4. ASTM C 1260 was essentially repeated and the 14-
day expansions of both set of data should be comparable and should give an
indication about the variation of the procedures when the same materials and
procedures are used and when the tests are performed by the same laboratory
operators.
0.000
0.050
0.100
0.150
0.200
0.250
0.300
0.350
0.400
0.450
0.500
A1-WY A9-NE B4-VA C2-SD D2-IL E2-IA E4-NV E6-IN E8-NM
Aggregate Investigated
14-D
ay E
xpan
sion
, %
14-day expansions generated for the 56-day procedures
14-day expansions generated for the 14-day procedures
It can be seen from Figure 9.4 that the expansions are comparable with some
differences that are comparable to the differences noted between the data generated
for this study and the data examined by the NAA.
Figure 9.4: Comparison Between the 14-Day Expansions Generated for the ASTM C 1260 and for the 56-Day Extended ASTM C 1260
187
0.00
0.10
0.20
0.30
0.40
0.50
0.60
0 4 8 12 16 20 24 28 32 36 40 44 48 52 56 60
Time, Days
Exp
ansi
on, %
A1-WYA9-NE
0.00
0.10
0.20
0.30
0.40
0.50
0.60
0 4 8 12 16 20 24 28 32 36 40 44 48 52 56 60
Time, Days
Exp
ansi
on, % B4-VA
C2-SDD2-IL
Figure 9.5: 56-Day C 1260 Results for Category A Aggregates
Figure 9.6: 56-Day C 1260 Results for Category B, C, & D Aggregates
188
0.00
0.20
0.40
0.60
0.80
1.00
1.20
1.40
1.60
0 4 8 12 16 20 24 28 32 36 40 44 48 52 56 60
Time, Days
Exp
ansi
on, % E2-IA
E4-NVE6-INE8-NM
Using the criteria of 0.33% at 28 days, and 0.48% at 56 proposed by Rogers
(1996), the following observations were recorded:
1. Slowly reactive aggregates B4-VA and C2-SD showed 28-day expansions of
0.26%. The two aggregates also exhibited 56-day expansions of 0.46% and
0.48% respectively. Both the 28-day and the 56-day expansions of both
aggregates were lower than the proposed limits and as such should be classified
as innocuous, which is false. These two aggregates are slowly reactive aggregates
as it was determined using ASTM C 1260 (Table 9.1), ASTM C 1293 (Table
10.1), and field performance (Table 8.3). Thus using the proposed criteria it was
not possible to correctly characterize the reactivity of the slowly reactive
aggregates tested.
Figure 9.7: 56-Day C 1260 Results for Category E Aggregates
189
2. Using the same line of reasoning, all Category E aggregates were all
characterized as reactive, which is true for E4-NV and E8-NM but not E2-IA and
E6-IN.
3. Using the proposed criteria for the 28-day and 56-day expansions, Category D
aggregates were correctly characterized as innocuous.
4. In summary, the criteria were not effective in detecting slowly reactive
aggregates and correctly characterizing Category E aggregates.
9.4 MODIFIED C 1260: ADJUSTING WATER CONTENT TO ACCOUNT FOR AGGREGATE ABSORPTION
For proportioning the mortar bar mixtures, ASTM C 1260 requires using a water-
cement ratio that neglects the absorption of the processed aggregates. As mentioned
earlier, aggregates for these procedures are separated into sieve sizes and then
combined in a required percentage. This results in a high-fines aggregate with an
unknown absorption. That is why the absorption is neglected. In order to account for
the absorption of aggregates and obtain a constant 0.47 water-cement ratio for all
mixtures, the C 1260 procedures were repeated but using the absorption of
aggregates in calculating the water content. Mixture proportions for these tests were
included in Table 7.11. Results are shown in Table 9.6 and Figures 9.8 through 9.10.
190
Table 9.6: C 1260 Expansions for Mixtures Adjusted for Aggregate Absorption Expansion, % Aggregate
ID 0-day 4-day 7-day 11-day 14-day 21-day 28-day A2-WY 0.00 0.17 0.24 0.26 0.29 0.33 0.36 A4-ID 0.00 0.37 0.53 0.64 0.69 0.75 0.81
A6-NM 0.00 0.48 1.01 1.02 1.02 1.02 1.03 A7-NC 0.00 0.18 0.28 0.34 0.38 0.46 0.55 A9-NE 0.00 0.08 0.15 0.25 0.32 0.39 0.45 B2-MD 0.00 0.03 0.04 0.08 0.11 0.14 0.17 C2-SD 0.00 0.05 0.07 0.11 0.17 0.24 0.28 D2-IL 0.00 0.00 0.00 0.01 0.02 0.03 0.03 E2-IA 0.00 0.27 0.40 0.51 0.57 0.61 0.65 E4-NV 0.00 0.09 0.21 0.38 0.49 0.70 0.91 E6-IN 0.00 0.06 0.15 0.26 0.32 0.33 0.34
E8-NM 0.00 0.22 0.32 0.42 0.46 0.54 0.61
Increasing the water content of the mortar bars to satisfy the absorption of
aggregates and keeping a constant water-cement ratio of 0.47, resulted in the same
aggregate classification as the standard C 1260 procedures. The 14-day expansions
were slightly higher but still resulted in the same aggregate classification. The
additional water resulted in a much better workability of mortar bar mixtures as can
be seen from the flow numbers in Tables 7.2 (Standard Mixtures) and 7.11 (Adjusted
Water). Table 7.11 shows higher flow numbers and better workability. Still the
results increased slightly, and the aggregates were classified in the same categories.
It looks like these procedures can be used without affecting the testing results.
However, before making that conclusion additional testing should be performed
using aggregates that have 14-day expansions close to the 0.10% limit.
191
0.00
0.20
0.40
0.60
0.80
1.00
1.20
0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30
Time, Days
Exp
ansi
on, %
A2-WYA4-IDA6-NMA7-NCA9-NE
0.00
0.05
0.10
0.15
0.20
0.25
0.30
0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30
Time, Days
Exp
ansi
on, % B2-MD
C2-SDD2-IL
Figure 9.8: Modified Water C 1260 Expansions for Category A Aggregates
Figure 9.9: Modified Water C 1260 Expansions for Category B, C, & D Aggregates
192
0.00
0.10
0.20
0.30
0.40
0.50
0.60
0.70
0.80
0.90
1.00
0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30
Time, Days
Exp
ansi
on, % E2-IA
E4-NVE6-INE8-NM
Figure 9.10: Modified Water C 1260 Expansions for Category E Aggregates
193
9.5 MODIFIED C 1260: USING A POLYNOMIAL FITTING PROCEDURE FOR INTERPRETATION OF RESULTS
An attempt was made to use a polynomial fit procedure on the C 1260 expansion
test results versus time for each of the tested aggregates and then to plot the
coefficients of these curves against each other. Results are shown in Figure 9.11.
This process is discussed in more details by Johnston (Johnston, 1994), and was
mentioned in section 4.18.5 of this document.
There was a separation between reactive and innocuous aggregates as shown by
the two lines in Figure 9.11. These lines were developed using the expansion
readings over 14 days (specified in C 1260). The more reactive aggregates were to
the left of the graph and aggregate reactivity diminished from left to right. Slowly
reactive aggregates (Categories B and C) fell in between the two lines. Most of the
slowly reactive aggregates and innocuous aggregates were concentrated in the area
-0.40
-0.20
0.00
0.20
0.40
0.60
0.80
-0.08 -0.06 -0.04 -0.02 0.00 0.02 0.04 0.06 0.08
Coefficient, A2
Coe
ffic
ient
, A1 Category A
Category BCategory CCategory ECategory D
Innocuous Line A1 = -4.6821*A2 + 0.0024
Reactive Line A1 = -7.3833*A2 + 0.0868
Figure 9.11: Polynomial Regression Coefficients A1 vs. A2
Expansion = A2*Time + A1*SQRT(Time) + A0
194
where the lines meet. In this area the lines are too close to be able to make a definite
identification of the reactivity of aggregates. As a result, it was concluded that these
procedures are not very accurate in assessing the reactivity of aggregates and
interpreting the C 1260 expansions.
9.6 MODIFIED C 1260: USING KOLMOGOROV-AVRAMI-MEHL-JOHNSTON’S MODEL FOR INTERPRETATION OF RESULTS
Johnston evaluated the Kolmogorov-Avrami-Mehl-Johnston model in his 1998
paper. He concluded that using the model allows the correct prediction of an
aggregate reactivity with ln(k) equal to -6 being the separating value between
reactive and innocuous aggregates. Aggregates with ln(k) greater than -6 are reactive
and aggregates with ln(k) lower than -6 are innocuous. The model is discussed in
more details in section 4.18.5 of this document. The model was applied to Table 5.2
aggregates, and results are shown in Figure 9.12.
195
0.00
0.50
1.00
1.50
2.00
2.50
-10.0 -8.0 -6.0 -4.0 -2.0 0.0ln (Avrami Rate Constant k)
Avr
ami E
xpon
ent M Category A
Category BCategory CCategory DCategory E
Innocuous Slowly Reactive
Reactive
All Category D aggregates had ln(k) values smaller than –6 and M values larger
than 1. All Category A aggregates had ln(k) values larger than –6 and M values
smaller than 1. Category B and C aggregates had ln(k) values between –6 and –4 and
M values close to 1. Three of the Category E aggregates had ln(k) values larger than
–6 while one had a value slightly smaller than –6.
The K-A-M-J model is better than the polynomial fitting procedures. It provides a
better visualization and is more accurate. However, the model was not successful in
correctly predicting the reactivity of Category E aggregates. It resulted in the same
conclusions as the ones generated using the 14-day expansion of 0.10% criterion.
Thus, even though the model is a more realistic representation of the mortar bar
expansions, it did not provide new advantages. The classification of aggregates was
identical using the K-A-M-J model and the 14-day expansion criterion.
Figure 9.12a: Avrami’s Exponent M versus ln(k) illustrating Avrami’s Equation
Kolmogorov-Avrami-Mehl-Johnson Model Normal Results
196
9.6.1 K-A-M-J’s Model Applied to NAA Data
The NAA performed C 1293 and C 1260 on several aggregates, and the results
were listed in Table 4.17. As can be seen in that table, there is no correlation between
the C 1260 and C 1293 results. Most of the aggregates were tested innocuous with C
1293 while reactive with C 1260. This is basically the same problem as the Category
E problem (C 1260 is too severe for some aggregates). The K-A-M-J model was used
to evaluate these data, and results are shown in Figure 9.12b.
0.0
0.5
1.0
1.5
2.0
2.5
-10 -8 -6 -4 -2 0
Ln (Rate Constant K)
Exp
onen
t M
Innocuous Slowly Rapidly Reactive ReactiveFailed C 1260 Passed C 1293
Failed C 1260 Failed C 1293
From Table 4.17 it can be seen that aggregates with Lot numbers 007,008, 017,
043, 049, 052, 055, 060, 088, 129, and 139 (empty diamonds in Figure 9.12b) were
found to be reactive based on the C 1260 results and innocuous based on the C 1293
results. Thus, C 1260 was too severe for all these aggregates. The C 1260 data were
used to draw the K-A-M-J plot shown in Figure 9.12b, and it can be seen that all
these aggregates showed ln(k) values larger than –6. Thus, the K-A-M-J model
Figure 9.12b: K-A-M-J’s Model Results For NAA C 1260 Data
197
resulted in the same conclusions as the ones generated using C 1260 (the aggregates
are showing as reactive while passing the C 1293 test). The K-A-M-J did not provide
new information; it is basically a different way of arriving at the same results as for
the standard C 1260.
9.6.2 K-A-M-J’s Model Applied to Virginia’s Data
C 1260 data of several aggregates from Virginia were included in Table 4.12.
Again, C 1260 data were used to develop a K-A-M-J diagram that shows the
obtained ln (K) values in Figure 9.12c.
0
0.5
1
1.5
2
2.5
-10 -8 -6 -4 -2 0
Ln (Rate Constant K)
Exp
onen
t M
Innocuous Slowly Rapidly Reactive Reactive
Blacksburg
Warrenton
Basically, all aggregates were found to be reactive in field applications with the
exception of aggregates from Blacksburg and Warrenton. A K-A-M-J plot was
Figure 9.12c: K-A-M-J’s Model Results For Virginia Aggregates
198
generated as Figure 9.12c where it can be seen that all aggregates showed ln(k)
values larger than –6 with the exception of the Blacksburg aggregate that showed a
ln(k) value smaller than –6. In Table 4.12 it can be seen that the Blacksburg
aggregate was found to be innocuous showing 14-day expansion of 0.09% when
tested using C 1260, which corresponded to a ln(k) value of –6.2, slightly smaller
than –6. Thus, the same conclusion was generated using ASTM C 1260 and the K-A-
M-J model.
On the other hand, the Warrenton aggregate was innocuous in the field but
showed C 1260, 14-day expansion, equals to 0.13%, which is slightly above the
limit, and thus, was labeled as Reactive. Using Figure 9.12c indicated that this
aggregate has a ln(k) value slightly larger than –6 which classifies that aggregate as
reactive. Thus, using the K-A-M-J’s model, it was possible to regenerate the C 1260
conclusion. The model did not correlate with the field performance but with the
expansions generated using C 1260.
The rest of the aggregates were reactive in the field and were classified as reactive
using both C 1260 procedures and K-A-M-J’s model. Thus, the same conclusions
that were obtained using the C 1260 procedures were generated using the K-A-M-J
model. Again, results indicate that the model is a more sophisticated method for
saying the same thing.
9.7 MODIFIED C 1260: CHANGING THE MOLARITY OF THE TESTING SOLUTION
In order to investigate the effect of the cement alkali content on ASR using C
1260, the investigated aggregates were tested in solutions with varying molarities,
namely, 1N (standard), 0.75N, 0.5N, and 0.25N. This was also performed to
determine whether using a lower concentration for the curing solution could result in
more reliable results. Mixture proportions used for the standard test (Table 7.2) were
199
used, also. Results for this set of testing are illustrated in Tables 9.6 through 9.9 and
Figures 9.13 through 9.18. Detailed expansions for all aggregates investigated, under
the different molarity solutions, are included in Appendix A.
Table 9.6: Expansions of Category A Aggregates (Different Molarity Solutions) Expansion, % Mixture
ID 4-Day 7-Day 11-Day 14-Day 21-Day 28-Day A1-WY 1N 0.12 0.18 0.21 0.24 0.31 0.32
A1-WY 0.75N 0.05 0.11 0.17 0.20 0.24 0.25 A1-WY 0.50N 0.01 0.03 0.05 0.06 0.10 0.12 A1-WY 0.25N 0.01 0.01 0.01 0.02 0.03 0.04
A2-WY 1N 0.18 0.24 0.27 0.29 0.34 0.37 A2-WY 0.75N 0.11 0.17 0.21 0.25 0.28 0.34 A2-WY 0.50N 0.02 0.05 0.08 0.09 0.13 0.14 A2-WY 0.25N 0.01 0.01 0.02 0.02 0.03 0.05
A4-ID 1N 0.45 0.62 0.75 0.79 0.89 0.95 A4-ID 0.75N 0.31 0.49 0.64 0.72 0.79 0.88 A4-ID 0.50N 0.08 0.18 0.27 0.30 0.40 0.43 A4-ID 0.25N 0.01 0.01 0.06 0.09 0.16 0.21 A6-NM 1N 0.50 0.67 0.83 0.91 1.04 1.12
A6-NM 0.75N 0.37 0.58 0.76 0.86 0.97 1.11 A6-NM 0.50N 0.10 0.21 0.30 0.33 0.45 0.51 A6-NM 0.25N 0.01 0.01 0.07 0.12 0.22 0.29
A7-NC 1N 0.13 0.23 0.28 0.31 0.39 0.48 A7-NC 0.75N 0.06 0.16 0.24 0.29 0.33 0.40 A7-NC 0.50N 0.01 0.02 0.04 0.06 0.10 0.11 A7-NC 0.25N 0.01 0.01 0.01 0.02 0.02 0.02
A9-NE 1N 0.07 0.14 0.23 0.28 0.39 0.43 A9-NE 0.75N 0.02 0.04 0.08 0.12 0.20 0.27 A9-NE 0.50N 0.02 0.03 0.04 0.06 0.12 0.17 A9-NE 0.25N 0.01 0.01 0.01 0.01 0.01 0.01 A10-PA 1N 0.02 0.07 0.19 0.26 0.40 0.49
A10-PA 0.75N 0.01 0.03 0.08 0.18 0.34 0.53 A10-PA 0.50N 0.02 0.02 0.03 0.04 0.10 0.21
200
Table 9.7: Expansions of Category B, C, & D Agg. (Different Molarity Solutions)
Expansion, % Mixture ID 4-Day 7-Day 11-Day 14-Day 21-Day 28-Day
B2-MD 1N 0.04 0.07 0.09 0.11 0.16 0.18 B2-MD 0.75N 0.02 0.03 0.06 0.08 0.11 0.17 B2-MD 0.50N 0.01 0.01 0.03 0.04 0.07 0.10 B2-MD 0.25N 0.00 0.02 0.02 0.02 0.02 0.03
B4-VA 1N 0.02 0.06 0.11 0.15 0.25 0.28 B4-VA 0.75N 0.02 0.04 0.05 0.10 0.19 0.25 B4-VA 0.50N 0.01 0.02 0.03 0.04 0.08 0.11 B4-VA 0.25N 0.01 0.01 0.01 0.02 0.02 0.02
C2-SD 1N 0.05 0.10 0.14 0.17 0.24 0.30 C2-SD 0.75N 0.03 0.06 0.07 0.11 0.19 0.25 C2-SD 0.50N 0.01 0.02 0.05 0.07 0.11 0.15 C2-SD 0.25N 0.00 0.01 0.02 0.02 0.02 0.02
D2-IL 1N 0.00 0.01 0.02 0.02 0.03 0.03 D2-IL 0.75N 0.00 0.01 0.02 0.02 0.02 0.03 D2-IL 0.50N 0.00 0.01 0.01 0.01 0.02 0.02 D2-IL 0.25N 0.00 0.00 0.01 0.01 0.01 0.01
201
Table 9.8: Expansions of Category E Aggregates (Different Molarity Solutions) Expansion, % Mixture
ID 4-Day 7-Day 11-Day 14-Day 21-Day 28-Day E2-IA 1N 0.12 0.24 0.38 0.42 0.53 0.62
E2-IA 0.75N 0.10 0.17 0.31 0.37 0.45 0.48 E2-IA 0.50N 0.00 0.01 0.02 0.03 0.04 0.04 E2-IA 0.25N 0.00 0.00 0.01 0.02 0.05 0.07 E4-NV 1N 0.04 0.06 0.18 0.25 0.44 0.64
E4-NV 0.75N 0.05 0.06 0.13 0.17 0.31 0.41 E4-NV 0.50N 0.02 0.04 0.05 0.09 0.14 0.20 E4-NV 0.25N 0.00 0.01 0.02 0.02 0.02 0.03
E6-IN 1N 0.03 0.10 0.20 0.25 0.34 0.43 E6-IN 0.75N 0.02 0.05 0.12 0.16 0.27 0.33 E6-IN 0.50N 0.01 0.01 0.02 0.04 0.07 0.12 E6-IN 0.25N 0.00 0.01 0.01 0.01 0.01 0.01 E8-NM 1N 0.10 0.22 0.33 0.36 0.46 0.54
E8-NM 0.75N 0.04 0.09 0.19 0.22 0.29 0.33 E8-NM 0.50N 0.01 0.02 0.03 0.04 0.05 0.06 E8-NM 0.25N 0.00 0.01 0.01 0.02 0.04 0.07
202
Table 9.9: 14-Day Expansions of the Different Testing Solutions 14-Day Expansions, %
Aggregate ID 1N NaOH 0.75N NaOH 0.50N NaOH 0.25N NaOH A1-WY 0.24 0.20 0.06 0.02 A2-WY 0.29 0.25 0.09 0.02 A4-ID 0.79 0.72 0.30 0.09
A6-NM 0.91 0.86 0.33 0.12 A7-NC 0.31 0.29 0.06 0.02 A9-NE 0.28 0.12 0.06 0.01 A10-PA 0.26 0.18 0.04 0.02 B2-MD 0.11 0.08 0.04 0.02 B4-VA 0.15 0.10 0.04 0.02 C2-SD 0.17 0.11 0.07 0.02 D2-IL 0.02 0.02 0.01 0.01 E2-IA 0.42 0.37 0.03 0.02 E4-NV 0.25 0.17 0.09 0.02 E6-IN 0.25 0.16 0.04 0.01
E8-NM 0.36 0.22 0.04 0.02
203
0.000.040.080.120.160.200.240.280.320.360.400.440.480.520.560.600.640.680.720.760.800.840.880.920.96
A1-WY A2-WY A4-ID A6-NM A7-NC A9-NE A10-PA
Investigated Aggregate
14-D
ay E
xpan
sion
, %
1N NaOH0.75N NaOH0.50N NaOH0.25N NaOH
0.000.020.040.060.080.100.120.140.160.18
B2-MD B4-VA C2-SD D2-IL
Investigated Aggregate
14-D
ay E
xpan
sion
, %
1N NaOH0.75N NaOH0.50N NaOH0.25N NaOH
Figure 9.13: 14-Day Expansion Comparison Between Different Curing Solutions, Category A Aggregates
Figure 9.14: 14-Day Expansion Comparison Between Different Curing Solutions Category B, C, & D Aggregates
204
0.000.040.080.120.160.200.240.280.320.360.400.440.48
E2-IA E4-NV E6-IN E8-NM
Investigated Aggregate
14-D
ay E
xpan
sion
, %
1N NaOH0.75N NaOH0.50N NaOH0.25N NaOH
As mentioned earlier in section 4.18.2, the varying levels of normalities could
be used to determine a cement alkali level below which the aggregates do not exhibit
deleterious expansions. These different normalities corresponds to cement alkali
content defined by equation 9.1 that is the same as equation 4.4 (Starks, 1993):
LmolescwONaOH /06.0022.0
/2339.0][ ±+=− (Eq 9.1)
The following list of figures will illustrate the generated expansion results using
1N, 0.75N, 0.50N, and 0.25N NaOH solutions. On each figure, the corresponding
cement alkali content is indicated on a separate axis.
Figure 9.15: 14-Day Expansion Comparison Between Different Curing Solutions Category E Aggregates
205
0.000.100.200.300.400.500.600.700.800.901.00
0 0.2 0.4 0.6 0.8 1 1.2
NaOH Solution Normality
14-D
ay E
xpan
sion
, % A1-WYA2-WYA4-IDA6-NMA7-NCA9-NEA10-PA
0.000.020.040.060.080.100.120.140.160.180.20
0 0.2 0.4 0.6 0.8 1 1.2
NaOH Solution Normality
14-D
ay E
xpan
sion
, %
B2-MDB4-VAC2-SDD2-IL
Figure 9.16: Category A Results at Different Solution Normalities and Cement Alkali Content
0.39 0.67 0.95 1.22 1.50
Cement Alkali Na2Oequiv.
0.39 0.67 0.95 1.22 1.50
Figure 9.17: Category B, C, & D Results at Different Solution Normalities and Cement Alkali Content
Cement Alkali Na2Oequiv.
206
0.000.040.080.120.160.200.240.280.320.360.400.440.48
0 0.2 0.4 0.6 0.8 1 1.2
NaOH Solution Normality
14-D
ay E
xpan
sion
, %
E2-IAE4-NVE6-INE8-NM
Starks (1993) was the first to investigate these procedures (Section 4.18.2). He
suggested that the test failure criteria must be adjusted progressively downward from
0.08% at 1.0N to a minimum of about 0.02% as solution normality decreases to
about 0.6N (Figure 4.3). Thus, for the 0.5N (0.81% Na2Oequiv.) and 0.25N (0.46%
Na2Oequiv.) NaOH solutions, the failure criterion should be 0.02% and for the 0.75N
(1.15% Na2Oequiv.) NaOH solution the failure criterion should be 0.04%. These
criteria were used to evaluate the result listed above.
Results indicated that as the solution normality decreased the expansions
decreased progressively. The following observations were recorded:
0.39 0.67 0.95 1.22 1.50
Figure 9.18: Category E Results at Different Solution Normalities and Cement Alkali Content
Cement Alkali Na2Oequiv.
207
1. The highly reactive aggregates A4-ID and A6-NM of Category A were reactive
even when tested using the 0.25N solution (0.46% Na2Oequiv.).
2. The moderately reactive aggregates of Category A, namely A1-WY, A2-WY,
A7-NC, A9-NE, and A10-PA showed 14-day expansions lower than 0.02% when
tested using the 0.25N solution (0.46% Na2Oequiv.). When 0.50N solution was
used all Category A aggregates showed expansions higher than the proposed
limit of 0.04%.
3. A solution normality of 0.25N (0.46% Na2Oequiv.) was required to decrease the
14-day expansions of slowly reactive aggregates of Categories B and C below
0.02%. Testing at a higher cement alkali content of 0.81% Na2Oequiv. (i.e. higher
solution normality of 0.50N) resulted in 14-day expansions higher than the safe
limit of 0.04%.
4. Category E aggregates had similar behavior to the slowly reactive aggregates. A
solution normality of 0.25N (0.46% Na2Oequiv.) was required to decrease the 14-
day expansions below 0.02%. Testing at a higher cement alkali content of 0.81%
Na2Oequiv. (i.e. higher solution normality of 0.50N) resulted in 14-day expansions
higher than the safe limit of 0.04%. This contradicts the field performance reports
of E2-IA which indicate that the aggregate has been successfully used in field
application with cement alkali contents higher than 0.9%. In addition, E2-IA and
E6-IN have both passed the C 1293 test (corresponding to 1.25% alkali content).
Thus, these procedures are very conservative and very severe for these
aggregates.
5. These observations are summarized in Table 9.10.
208
Table 9.10: Effect of Na2Oequiv. Content on ASR Using ASTM C 1260 Na2Oequiv. Cement Content
1.15% 0.81% 0.46% NaOH Solution Normality Aggregate
ID
C 1260 14-Day
Expansiona 0.75Nb 0.50Nc 0.25Nc
A1-WY 0.24% H.R.
Reactive Reactive Innocuous
A2-WY 0.29% H.R.
Reactive Reactive Innocuous
A4-ID 0.79% H.R.
Reactive Reactive Reactive
A6-NM 0.91% H.R.
Reactive Reactive Reactive
A7-NC 0.31% H.R.
Reactive Reactive Innocuous
A9-NE 0.28% H.R.
Reactive Reactive Innocuous
A10-PA 0.26% H.R.
Reactive Reactive Innocuous
B2-MD 0.12% S.R.
Reactive Reactive Innocuous
B4-VA 0.15% S.R.
Reactive Reactive Innocuous
C2-SD 0.17% S.R.
Reactive Reactive Innocuous
D2-IL 0.02% Innocuous
Innocuous Innocuous Innocuous
E4-NV 0.25% H.R.
Reactive Reactive Innocuous
E6-IN 0.25% H.R.
Reactive Reactive Innocuous
E2-IA 0.42% H.R.
Reactive Reactive Innocuous
E8-NM 0.36% H.R.
Reactive Reactive Innocuous
aH.R. = ASTM C 1260 14-day expansion > 0.20% aS.R. = 0.10% < ASTM C 1260 14-day expansion < 0.20%
aInnocuous = ASTM C 1260 14-day expansion < 0.10% bReactive = 14-day expansion > 0.04% ; Innocuous = 14-day expansion < 0.04% cReactive = 14-day expansion > 0.02% ; Innocuous = 14-day expansion < 0.02%
209
In summary, changing the solution molarity was not an effective modification of
the ASTM C 1260. Decreasing the solution normality will not solve the severity of
ASTM C 1260. However, changing the NaOH solution normality can be used to
evaluate the effect of cement Na2Oequiv. content on ASR. These procedures are very
conservative and will result in a worst-case scenario. Using the proposed limit, it was
found that a cement alkali content of about 0.5% Na2Oequiv. was effective in
decreasing the 14-day expansions to safe levels for moderately and slowly reactive
aggregates. Highly reactive aggregates were still showing deleterious expansions at
that level.
210
CHAPTER TEN
ASTM C 1293 TESTS RESULTS AND DISCUSSION
“TEST METHOD FOR CONCRETE AGGREGATES BY DETERMINATION OF LENGTH CHANGE OF CONCRETE DUE TO ALKALI-SILICA
REACTION”
10.1 ASTM C 1293
ASTM C 1293 is a concrete prism test that is used to test for the potential alkali-
silica reactivity of aggregates and concrete mixtures. The test consists of casting
three 3”x3”x11” concrete prisms using the aggregate in question and storing the
prisms over water, in a sealed container with wicks covering the sides, at 380C. Some
of the test procedures requirements include the use of (1) a cement content of 708 ±
17 lb, (2) a volume of coarse aggregate per unit volume of concrete of 0.70 ± 0.2%
based on the oven-dry-rodded weight, and (3) a water-cement ratio of 0.42 to 0.45 by
mass. The alkali content of the prisms, Na2Oequiv., is increased to 1.25% by adding
NaOH to the mixing water. Expansions are measured periodically over a period of
one year. Concrete mixtures exhibiting one-year expansions larger than 0.040% are
considered reactive while mixtures showing one-year expansions lower than 0.040%
are considered innocuous.
Aggregates listed in Table 5.2 were tested using the ASTM C 1293 procedures
described in section 6.3.3 and the results are shown in Tables 10.1 through 10.3 and
Figures 10.1 through 10.4. Mixture proportions for these tests were included in Table
7.12.
211
Table 10.1: ASTM C 1293 Results for Category A Aggregates Expansion, %
Time A1-WY A2-WY A3-ID A4-ID A5-NM A6-NM A7-NC A8-VA A9-NE A10-PA1-week 0.005 0.003 0.015 0.019 0.000 0.006 0.000 0.015 0.006 0.008 2-week 0.010 0.005 0.008 0.026 0.009 0.013 0.002 0.017 0.015 0.011 4-week 0.014 0.009 0.008 0.039 0.019 0.048 0.001 0.024 0.019 0.012 6-week 0.018 0.010 0.009 0.092 0.026 0.117 0.002 0.017 0.020 0.017 8-week 0.020 0.013 0.016 0.141 0.034 0.175 0.004 0.021 0.025 0.017
13-week 0.030 0.018 0.020 0.216 0.048 0.266 0.010 0.024 0.031 0.024 18-week 0.034 0.028 0.030 0.267 0.068 0.320 0.025 0.031 0.035 0.024 26-week 0.048 0.067 0.043 0.319 0.077 0.371 0.057 0.040 0.036 0.035 39-week 0.069 0.109 0.053 0.350 0.086 0.400 0.077 0.051 0.037 0.039 52-week 0.073 0.107 0.058 0.379 0.084 0.411 0.085 0.047 0.051 0.043
Table 10.2: ASTM C 1293 Results for Category B, C, & D Aggregates Expansion, %
Time B1-MD B2-MD B4-VA C1-SD C2-SD D2-IL 1-week 0.000 0.006 0.001 0.001 0.010 0.003 2-week 0.002 0.004 0.005 0.003 0.006 0.004 4-week 0.004 0.015 0.008 0.006 0.015 0.007 6-week 0.007 0.016 0.007 0.010 0.017 0.008 8-week 0.009 0.019 0.010 0.014 0.019 0.010
13-week 0.012 0.026 0.013 0.022 0.025 0.014 18-week 0.020 0.029 0.016 0.036 0.030 0.016 26-week 0.028 0.041 0.022 0.048 0.043 0.019 39-week 0.036 0.045 0.030 0.061 0.051 0.024 52-week 0.040 0.046 0.040 0.063 0.053 0.022
212
Table 10.3: Standard ASTM C 1293 Results for Category E Aggregates Expansion, %
Time E2-IA E3-NV E4-NV E6-IN E7-NM E8-NM 1-week 0.009 0.003 0.001 0.002 0.000 0.001 2-week 0.011 0.005 0.001 0.005 0.000 0.001 4-week 0.014 0.008 0.004 0.007 0.001 0.002 6-week 0.015 0.014 0.003 0.008 0.006 0.003 8-week 0.016 0.015 0.005 0.010 0.006 0.005
13-week 0.019 0.018 0.014 0.011 0.010 0.012 18-week 0.021 0.023 0.041 0.018 0.014 0.046 26-week 0.027 0.029 0.046 0.019 0.024 0.048 39-week 0.028 0.029 0.048 0.022 0.026 0.050 52-week 0.025 0.058 0.060 0.022 0.063 0.064
0.000.040.080.120.160.200.240.280.320.360.400.44
0 4 8 12 16 20 24 28 32 36 40 44 48 52 56
Time, Days
Exp
ansi
on, %
A1-WYA2-WYA3-IDA4-IDA5-NMA6-NMA7-NCA8-VAA9-NEA10-PA
Figure 10.1a: ASTM C 1293 Results for Category A Aggregates
213
0.000.010.020.030.040.050.060.070.080.090.10
0 4 8 12 16 20 24 28 32 36 40 44 48 52 56
Time, Days
Exp
ansi
on, %
A1-WYA3-IDA5-NMA7-NCA8-VA
0.000.040.080.120.160.200.240.280.320.360.400.44
0 4 8 12 16 20 24 28 32 36 40 44 48 52 56
Time, Days
Exp
ansi
on, %
A2-WYA4-IDA6-NMA9-NEA10-PA
Figure 10.1b: ASTM C 1293 Results for Coarse Aggregates of Category A
Figure 10.1c: ASTM C 1293 Results for Fine Aggregates of Category A
214
-0.01
0.00
0.01
0.02
0.03
0.04
0.05
0.06
0.07
0 4 8 12 16 20 24 28 32 36 40 44 48 52 56
Time, Days
Exp
ansi
on, %
B1-MDB2-MDB4-VAC1-SDC2-SDD2-IL
-0.02
0.00
0.02
0.04
0.06
0.08
0 4 8 12 16 20 24 28 32 36 40 44 48 52 56
Time, Days
Exp
ansi
on, %
E2-IAE3-NVE4-NVE6-INE7-NME8-NM
Figure 10.2: ASTM C 1293 Results for Category B, C, & D Aggregates
Figure 10.3: ASTM C 1293 Results for Category E Aggregates
215
0.00
0.04
0.08
0.12
0.16
0.20
0.24
0.28
0.32
0.36
0.40
0.44
WY ID A-NM MD SD NV E-NM
Investigated Source
12-M
onth
Exp
ansi
on, %
Fine AggregateCoarse Aggregate
An expansion limit of 0.040%, after one year (52 weeks) of testing, was used as a
cut off point between reactive and innocuous aggregates. This limit is what the
standard test calls for and is the limit that is most accepted and used in the literature.
As can be seen from the results above, Category A aggregates, which are highly
reactive, have all shown one-year expansions higher than 0.040%. The expansions
varied from 0.047% to 0.308%. Categories B and C aggregates, which are slowly
reactive, have also shown one-year expansions higher than 0.040% and varying
between 0.040% and 0.063%. Only one Category D aggregate (Innocuous) was
tested and it showed one-year expansion lower than 0.040% specifically, 0.022%.
E4-NV and E8-NM of Category E were found to be reactive with one-year
expansions higher than 0.040%. The coarse aggregates corresponding to these
Figure 10.4: Comparison Between the 12-month Expansions of Tested Coarse and Fine Aggregates from the Same Source
216
aggregates, E3-NV and E8-NM, showed lower expansions than the fine aggregates
however they still were found to be reactive. This correlates well with the field
performance record, and the petrographic analysis of these aggregates, shown in
Table 8.3. E2-IA and E6-IN of Category E were found to be innocuous with one-year
expansions lower than 0.040%, which also correlates well with the field performance
and the petrographic analysis reported in Table 8.3. As a result, using ASTM C 1293,
it was possible to predict the potential alkali-silica reactivity of all aggregates
investigated in a manner that correlated with the field performance records of these
aggregates. This was the only test that was capable of correctly portraying the field
performance of all aggregates. When tested in accordance with ASTM C 1260, E2-
IA and E6-IN, which have had good field performance records, were found to be
reactive but were found to be innocuous when tested in accordance with C 1293.
That is why the C 1260 procedures were labeled as being too severe for some
aggregates.
A comparison between expansions of coarse and fine aggregates from the same
source was included in Figure 10.4 where it can be seen that, with the exception of
SD aggregates, coarse aggregates showed much lower expansions than their
corresponding fine aggregates. This difference can be explained by the fact that fine
aggregates have a larger surface area than coarse aggregates and thus more reactive
silica surface is exposed to alkalis and as a result, higher expansions in shorter
amount of time are expected. Still the reactivity classification of coarse and fine
aggregates from the same source was the same for all combinations.
217
10.2 MODIFIED C 1293: PRISMS STORED IN A 1N NaOH SOLUTION AT 80OC
As mentioned earlier, ASTM C 1293 requires monitoring the expansions of
concrete prisms over a period of one year in order to obtain the final results. In an
effort to decrease the testing period and generate results in a shorter period of time,
ASTM C 1293 concrete prisms were stored in a 1N NaOH solution maintained at
800C. These measures are expected to accelerate the alkali-silica reaction. Mixture
proportions for these tests are the same as the standard C 1293 and are listed in Table
7.12. Results of these procedures are included in Tables 10.4 through 10.6 and
Figures 10.5 through 10.7. C 1293 procedures were followed for the fabrication of
prisms; however, the storage conditions were modified.
Table 10.4: Expansions of Concrete Prisms Stored in 1N NaOH Solution at 80oC for Category A Aggregates
Expansion, % Time A1-WY A2-WY A3-ID A4-ID A5-NM A6-NM A7-NC A8-VA A9-NE A10-PA
1-week 0.004 0.049 0.102 0.181 0.039 0.191 0.042 0.109 0.105 0.099 2-week 0.012 0.100 0.123 0.244 0.070 0.259 0.045 0.119 0.128 0.115 4-week 0.037 0.151 0.159 0.318 0.099 0.332 0.052 0.118 0.209 0.159 6-week 0.060 0.202 0.192 0.363 0.120 0.383 0.057 0.145 0.272 0.210 8-week 0.074 0.254 0.223 0.392 0.144 0.418 0.066 0.162 0.330 0.266
13-week 0.109 0.305 0.281 0.443 0.184 0.482 0.073 0.187 0.418 0.409 18-week 0.124 0.345 0.338 0.478 0.208 0.523 0.081 0.201 0.477 0.551 26-week 0.151 0.395 0.443 0.529 0.499 0.581 0.097 0.223 0.548 0.694 39-week 0.176 0.445 0.548 0.566 0.582 0.622 0.133 0.244 0.619 0.836 52-week 0.201 0.495 0.653 0.602 0.665 0.663 0.170 0.266 0.690 0.979
218
Table 10.5: Expansions of Concrete Prisms Stored in 1N NaOH Solution at 80oC for Category B, C, & D Aggregates
Expansion, % Time B1-MD B2-MD B4-VA C1-SD C2-SD D2-IL
1-week 0.047 0.085 0.040 0.099 0.087 0.005 2-week 0.055 0.104 0.051 0.121 0.113 0.006 4-week 0.064 0.141 0.097 0.092 0.148 0.006 6-week 0.072 0.154 0.100 0.174 0.164 0.010 8-week 0.070 0.210 0.119 0.180 0.209 0.016
13-week 0.095 0.268 0.155 0.230 0.266 0.019 18-week 0.099 0.320 0.192 0.251 0.304 0.028 26-week 0.097 0.387 0.245 0.280 0.379 0.028 39-week 0.128 0.442 0.297 0.293 0.449 0.027 52-week 0.160 0.497 0.349 0.306 0.519 0.027
Table 10.6: Expansions of Concrete Prisms Stored in 1N NaOH Solution at 80oC for Category E Aggregates
Expansion, % Time E2-IA E3-NV E4-NV E6-IN E7-NM E8-NM
1-week 0.059 0.046 0.047 0.049 0.068 0.079 2-week 0.115 0.054 0.092 0.054 0.077 0.126 4-week 0.207 0.063 0.189 0.068 0.092 0.176 6-week 0.253 0.068 0.267 0.090 0.101 0.209 8-week 0.276 0.074 0.332 0.109 0.108 0.230
13-week 0.315 0.089 0.478 0.154 0.121 0.279 18-week 0.342 0.099 0.585 0.193 0.131 0.314 26-week 0.385 0.157 0.896 0.259 0.145 0.374 39-week 0.428 0.252 1.207 0.325 0.153 0.435 52-week 0.471 0.692 1.518 0.391 0.322 0.495
219
0.000.100.200.300.400.500.600.700.800.901.001.10
0 4 8 12 16 20 24 28 32 36 40 44 48 52 56
Time, Weeks
Exp
ansi
on, %
A1-WYA2-WYA3-IDA4-IDA5-NMA6-NMA7-NCA8-VAA9-NEA10-PA
0.00
0.04
0.08
0.12
0.16
0.20
0.24
0.28
0.32
0.36
0 1 2 3 4 5
Time, Weeks
Exp
ansi
on, %
A1-WYA2-WYA3-IDA4-IDA5-NMA6-NMA7-NCA8-VAA9-NEA10-PA
Figure 10.5a: 52-Week (one-year) Expansions of Concrete Prisms Stored in 1N NaOH solution at 80oC for Category A Aggregates
Figure 10.5b: Four-Week Expansions of Concrete Prisms Stored in 1N NaOH Solution at 80oC for Category A Aggregates
220
0.00
0.10
0.20
0.30
0.40
0.50
0.60
0 4 8 12 16 20 24 28 32 36 40 44 48 52 56
Time, Weeks
Exp
ansi
on, %
B1-MDB2-MDB4-VAC1-SDC2-SDD2-IL
0.00
0.04
0.08
0.12
0.16
0 1 2 3 4 5
Time, Weeks
Exp
ansi
on, %
B1-MDB2-MDB4-VAC1-SDC2-SDD2-IL
Figure 10.6a: 52-Week (One-year) Expansions of Concrete Prisms Stored in 1N NaOH Solution at 80oC for Category B, C, and D Aggregates
Figure 10.6b: Four-Week Expansions of Concrete Prisms Stored in 1N NaOH solution at 80oC for Category B, C, and D Aggregates
221
0.00
0.20
0.40
0.60
0.80
1.00
1.20
1.40
1.60
0 4 8 12 16 20 24 28 32 36 40 44 48 52 56
Time, Weeks
Exp
ansi
on, %
E2-IAE3-NVE4-NVE6-INE7-NME8-NM
0.00
0.04
0.08
0.12
0.16
0.20
0.24
0 1 2 3 4 5
Time, Weeks
Exp
ansi
on, %
E2-IAE3-NVE4-NVE6-INE7-NME8-NM
Figure 10.7a: 52-Week (one-year) Expansions of Concrete Prisms Stored in 1N NaOH Solution at 80oC for Category E Aggregates
Figure 10.7b: Four-Week Expansions of Concrete Prisms Stored in 1N NaOH Solution at 80oC for Category E Aggregates
222
A proposed limit of 0.040% after 4 weeks of testing was used to differentiate
between reactive and innocuous aggregates. Thus, 4-week expansions greater than
0.040% are indicative of reactive aggregates and vice versa. This limit was proposed
by researchers in the literature and was found to be most realistic.
From results shown in Figures 10.5 through 10.7, it can be seen that all aggregates
in Categories A, B, and C were classified as reactive and Category D aggregate was
classified as innocuous. These conclusions correlate well with the standard C 1293
test results as far as characterizing the reactivity of aggregates. Using these
procedures, Category E aggregates were all classified as reactive including E2-IA
and E6-IN, which is not in correlation with the standard C 1293 results. This means
that storing the concrete prisms in a 1N NaOH solution at 800C was too severe for
these aggregates. In addition, when tested using the standard C 1293 procedures, A9-
NE, A10-PA, and B2-MD exhibited one-year expansions lower than the expansion of
A5-NM but when tested using the 1N NaOH solution at 800C, all three aggregates
exhibited expansions that are higher than the A5-NM expansion (A5-NM was chosen
as the comparison aggregate). This means that these procedures were too severe
resulting in over estimating aggregate reactivity. Other aggregates exhibited similar
problems. Table 10.7 summarizes the above comparison.
223
Table 10.7: Summary of Generated Results: ASTM C 1293 vs 1N NaOH at 800C Using Respectively
0.040% at One Year and 0.040% at Four-Week as Failure Criteria
Field
Performance
100% R.H. 380C
Standarda
1N NaOH 800C
Modifiedb
A1-WY Reactive Reactive Reactive A2-WY Reactive Reactive Reactive A3-ID Reactive Reactive Reactive A4-ID Reactive Reactive Reactive
A5-NM Reactive Reactive Reactive A6-NM Reactive Reactive Reactive A7-NC Reactive Reactive Reactive A8-VA Reactive Reactive Reactive A9-NE Reactive Reactive Reactive A10-PA Reactive Reactive Reactive B1-MD Reactive Reactive Reactive B2-MD Reactive Reactive Reactive B4-VA Reactive Reactive Reactive C1-SD Reactive Reactive Reactive C2-SD Reactive Reactive Reactive D1-IL Innocuous Innocuous Innocuous E2-Ia Innocuous Innocuous Reactive
E3-NV Reactive Reactive Reactive E4-NV Reactive Reactive Reactive E6-IN Innocuous Innocuous Reactive
E7-NM Reactive Reactive Reactive E8-NM Reactive Reactive Reactive
a = ASTM C 1293 failure criterion is 0.040% at one year b = Failure criterion is 0.040% at 4 weeks Shaded area indicate aggregates with discrepancies
In an effort to solve that problem, the failure criterion of 0.040% after 4 weeks of
testing was changed and made more lenient. E2-IA and E6-IN, which according to
ASTM C 1293 and the field performance data should be innocuous, exhibited 1-
week expansions of 0.059% and 0.049% respectively when tested using the 1N
NaOH solution at 800C procedures. These were the lowest expansions recorded for
these two aggregates. Thus, in order for these procedures to produce results that
224
correlate with ASTM C 1293 and the field performance data of E2-IA and E6-IN, a
1-week expansion limit of 0.06% should be chosen as a cut off point between
reactive and innocuous aggregates. This is the only criterion that will result in E2-IA
and E6-IN to be innocuous aggregates. Using this criterion, 0.06% expansion after 1
week of testing, resulted in false results for A1-WY, A2-WY, A5-NM, and A7-NC,
indicating that these aggregates are innocuous with 1-week expansions lower than
0.06%. All these aggregates were classified as highly reactive when tested in
accordance with C 1260 and C 1293 and have had a bad field performance record as
mentioned in Table 8.3. The same erroneous results were generated for the slowly
reactive aggregates B1-MD and B4-VA. In addition, the reactive aggregates of
Category E, E3-NVand E4-NV, were labeled as innocuous. This is illustrated in
Table 10.8. As a result, using the criterion of 0.06% expansion after 1 week of testing
is not a good limit to use. Using the 4-week criterion of 0.040% resulted in better
results than the 1-week criterion; however, the results were on the high side.
A plot comparing these procedures to the standard C 1293 is included in Figure
10.8 where the above discrepancies are illustrated. E2-IA and E6-IN that showed
ASTM C 1293 one-year expansions lower than 0.040% have exhibited 4-week
expansions that are much higher than the proposed limit of 0.040%. In addition, the
450 line on the plot indicates the poor correlation between the ASTM C 1293
expansion results and the results generated by storing the concrete prisms in a 1N
NaOH solution at 800C.
225
Table 10.8: Summary of Generated Results: ASTM C 1293 vs 1N NaOH at 800C Using 0.040% at One Year and 0.060%
at 1 Week as Failure Criteria Respectively
Field
Performance
100% R.H. 380C
Standarda
1N NaOH 800C
Modifiedb
A1-WY Reactive Reactive Innocuous A2-WY Reactive Reactive Innocuous A3-ID Reactive Reactive Reactive A4-ID Reactive Reactive Reactive
A5-NM Reactive Reactive Innocuous A6-NM Reactive Reactive Reactive A7-NC Reactive Reactive Innocuous A8-VA Reactive Reactive Reactive A9-NE Reactive Reactive Reactive A10-PA Reactive Reactive Reactive B1-MD Reactive Reactive Innocuous B2-MD Reactive Reactive Reactive B4-VA Reactive Reactive Innocuous C1-SD Reactive Reactive Reactive C2-SD Reactive Reactive Reactive D1-IL Innocuous Innocuous Innocuous E2-Ia Innocuous Innocuous Reactive
E3-NV Reactive Reactive Innocuous E4-NV Reactive Reactive Innocuous E6-IN Innocuous Innocuous Reactive
E7-NM Reactive Reactive Reactive E8-NM Reactive Reactive Reactive
a = ASTM C 1293 failure criterion is 0.040% at one year b = Failure criterion is 0.06% at 1 weeks Shaded area indicate aggregates with discrepancies
226
0.00
0.04
0.08
0.12
0.16
0.20
0.24
0.28
0.32
0.36
0.00 0.04 0.08 0.12 0.16 0.20 0.24 0.28 0.32 0.36
ASTM C 1293 1-Year Expansions, %
4-w
eek
Exp
ansi
on, %
(1
N a
t 80-
deg.
)
E2-IA
E6-IN
ASTM C 1293
Failure Criterion
Modified C 1293 Failure
Criterion
These procedures are the same as the ones used for the C 1260 procedures
(Mortar-Bar Test), and in both tests E2-IA and E6-IN were classified as reactive
even though they have good performance in the field and passed ASTM C 1293. In
addition, Starks (1993) and Fournier (1992) investigated aggregates using these
procedures, and they concluded that they are inadequate. Several innocuous
aggregates showed higher expansions than reactive aggregates. These procedures are
inadequate and should not be used to differentiate between reactive and innocuous
aggregates.
Figure 10.8: Comparison Between the Standard C 1293 Procedures and Modified C 1293 Storing Prisms in 1N NaOH at 800C
227
10.3 MODIFIED C 1293: PRISMS STORED IN A 1N NAOH SOLUTION AT 38OC
As mentioned earlier, ASTM C 1293 requires monitoring the expansions of
concrete prisms over a period of one year in order to obtain the final results. In an
effort to decrease the testing period and to generate results in a shorter period of
time, ASTM C 1293 concrete prisms were stored in a 1N NaOH solution maintained
at 380C. These measures are expected to accelerate the alkali-silica reaction. Mixture
proportions for these tests are the same as for the standard C 1293 and are listed in
Table 7.12. Procedures are also similar to C 1293 with the exception of storage
environment. Results of these procedures are included in Tables 10.9 through 10.11
and Figures 10.9 through 10.11.
Table 10.9: Expansions of Concrete Prisms Stored in 1N NaOH Solution at 38oC for Category A Aggregates
Expansion, % Time A1-WY A2-WY A3-ID A4-ID A5-NM A6-NM A7-NC A8-VA A9-NE A10-PA
1-week 0.002 0.012 0.022 0.015 0.133 0.015 0.011 0.034 0.024 0.031 2-week 0.000 0.011 0.024 0.019 0.138 0.021 0.015 0.035 0.026 0.032 4-week 0.005 0.013 0.023 0.036 0.114 0.058 0.015 0.037 0.033 0.039 6-week 0.011 0.014 0.027 0.064 0.118 0.096 0.018 0.038 0.035 0.043 8-week 0.010 0.018 0.027 0.090 0.147 0.130 0.022 0.047 0.038 0.043
13-week 0.017 0.030 0.045 0.144 0.155 0.194 0.030 0.053 0.049 0.050 18-week 0.024 0.063 0.058 0.186 0.162 0.238 0.042 0.059 0.057 0.057 26-week 0.034 0.092 0.084 0.242 0.172 0.297 0.058 0.066 0.069 0.063 39-week 0.043 0.122 0.123 0.292 0.186 0.352 0.068 0.073 0.081 0.070 52-week 0.051 0.151 0.163 0.343 0.199 0.407 0.078 0.079 0.093 0.076
228
Table 10.10: Expansions of Concrete Prisms Stored in 1N NaOH Solution at 38oC for Category B, C, & D Aggregates
Expansion, % Time B1-MD B2-MD B4-VA C1-SD C2-SD D2-IL
1-week 0.020 0.023 0.011 0.026 0.020 0.013 2-week 0.020 0.027 0.012 0.027 0.020 0.014 4-week 0.020 0.029 0.012 0.027 0.023 0.014 6-week 0.022 0.026 0.013 0.029 0.022 0.015 8-week 0.022 0.030 0.014 0.029 0.024 0.014
13-week 0.028 0.038 0.019 0.041 0.031 0.021 18-week 0.034 0.050 0.023 0.050 0.040 0.026 26-week 0.042 0.071 0.045 0.064 0.052 0.025 39-week 0.049 0.103 0.055 0.077 0.072 0.025 52-week 0.057 0.135 0.065 0.091 0.091 0.026
Table 10.11: Expansions of Concrete Prisms Stored in 1N NaOH Solution at 38oC for Category E Aggregates
Expansion, % Time E2-IA E3-NV E4-NV E6-IN E7-NM E8-NM
1-week 0.006 0.014 0.012 0.015 0.013 0.014 2-week 0.007 0.015 0.014 0.015 0.010 0.013 4-week 0.007 0.017 0.019 0.016 0.012 0.016 6-week 0.011 0.018 0.029 0.018 0.013 0.019 8-week 0.015 0.019 0.048 0.018 0.014 0.024
13-week 0.020 0.022 0.089 0.022 0.020 0.060 18-week 0.030 0.025 0.122 0.033 0.026 0.103 26-week 0.036 0.030 0.161 0.038 0.033 0.145 39-week 0.041 0.032 0.201 0.042 0.040 0.187 52-week 0.046 0.069 0.240 0.046 0.095 0.229
229
0.000.040.080.120.160.200.240.280.320.360.400.44
0 4 8 12 16 20 24 28 32 36 40 44 48 52 56
Time, Weeks
Exp
ansi
on, %
A1-WYA2-WYA3-IDA4-IDA5-NMA6-NMA7-NCA8-VAA9-NEA10-PA
0.00
0.04
0.08
0.12
0.16
0.20
0.24
0.28
0.32
0 2 4 6 8 10 12 14 16 18 20 22 24 26 28
Time, Weeks
Exp
ansi
on, %
A1-WYA2-WYA3-IDA4-IDA5-NMA6-NMA7-NCA8-VAA9-NEA10-PA
Figure 10.9a: 52-Week (one-year) Expansions of Concrete Prisms Stored in 1N NaOH Solution at 38oC for Category A Aggregates
Figure 10.9b: 13-Week (6-Month) Expansions of Concrete Prisms Stored in 1N NaOH Solution at 38oC for Category A Aggregates
230
0.00
0.02
0.04
0.06
0.08
0.10
0.12
0.14
0.16
0 4 8 12 16 20 24 28 32 36 40 44 48 52 56
Time, Weeks
Exp
ansi
on, %
B1-MDB2-MDB4-VAC1-SDC2-SDD2-IL
0.00
0.02
0.04
0.06
0.08
0 2 4 6 8 10 12 14 16 18 20 22 24 26 28
Time, Weeks
Exp
ansi
on, %
B1-MDB2-MDB4-VAC1-SDC2-SDD2-IL
Figure 10.10a: 52-Week (one-year) Expansions of Concrete Prisms Stored in 1N NaOH Solution at 38oC for Category B, C, & D Aggregates
Figure 10.10b: 13-Week (6-month) Expansions of Concrete Prisms Stored in 1N NaOH Solution at 38oC for Category B, C, & D Aggregates
231
0.000.020.040.060.080.100.120.140.160.180.200.220.240.26
0 4 8 12 16 20 24 28 32 36 40 44 48 52 56
Time, Weeks
Exp
ansi
on, %
E2-IAE3-NVE4-NVE6-INE7-NME8-NM
0.00
0.02
0.04
0.06
0.08
0.10
0.12
0.14
0.16
0.18
0 2 4 6 8 10 12 14 16 18 20 22 24 26 28
Time, Weeks
Exp
ansi
on, %
E2-IAE3-NVE4-NVE6-INE7-NME8-NM
Figure 10.11a: 52-Week (one-year) Expansions of Concrete Prisms Stored in 1N NaOH Solution at 38oC for Category E Aggregates
Figure 10.11b: 13-Week (6-month) Expansions of Concrete Prisms Stored in 1N NaOH Solution at 38oC for Category E Aggregates
232
A proposed expansion limit for these procedures is 0.040% after 6 months (26
weeks) of testing. Thus, 26-week expansions higher than 0.040% are representative
of reactive aggregates. In the literature, these procedures were found to be effective
in correctly predicting the reactivity of aggregates.
Results indicate that using a 26-week expansion limit of 0.040% results in the
same aggregate classification as the standard C 1293 test. Category A, B, and C
aggregates were all found to be reactive; Category D aggregate was found to be
innocuous; E2-IA and E6-IN of Category E were found to be innocuous; and E4-NV
and E8-NM of Category E were found to be reactive. These are the same
conclusions obtained using the standard C 1293 procedures. Basically, storing the
concrete prisms in a 1N NaOH solution at 380C resulted in the same results but in a
shorter time (26-weeks). This is illustrated in Table 10.12.
It should be noted, however, that the 26-week expansions of E2-IA and E6-IN
were respectively 0.036% and 0.038% both of which are very close to the 0.040%
limit and should be considered potentially reactive according to these procedures. In
addition, several aggregates were characterized as highly reactive while they were
showing as slowly reactive with the standard C 1293 (Figure 10.12). These
aggregates included E4-NV and E8-NM. As a result, these procedures were deemed
to be effective in detecting reactive aggregates but might be too severe for some
aggregates such E2-IA and E6-IN and might be over conservative with other
aggregates. A plot comparing these procedures to the standard C 1293 is included in
Figure 10.12 which shows a better distribution around the 450 line than the previous
results generated by storing concrete prisms in 1N NaOH solution at 800C.
233
Table 10.12: Summary of Generated Results: ASTM C 1293 vs 1N NaOH at 380C Using 0.040% at One Year and 0.040%
at 26 Weeks as Failure Criteria Respectively
Field
Performance
100% R.H. 380C
Standarda
1N NaOH 800C
Modifiedb
A1-WY Reactive Reactive Reactive A2-WY Reactive Reactive Reactive A3-ID Reactive Reactive Reactive A4-ID Reactive Reactive Reactive
A5-NM Reactive Reactive Reactive A6-NM Reactive Reactive Reactive A7-NC Reactive Reactive Reactive A8-VA Reactive Reactive Reactive A9-NE Reactive Reactive Reactive A10-PA Reactive Reactive Reactive B1-MD Reactive Reactive Reactive B2-MD Reactive Reactive Reactive B4-VA Reactive Reactive Reactive C1-SD Reactive Reactive Reactive C2-SD Reactive Reactive Reactive D1-IL Innocuous Innocuous Innocuous E2-Ia Innocuous Innocuous Innocuous
E3-NV Reactive Reactive Reactive E4-NV Reactive Reactive Reactive E6-IN Innocuous Innocuous Innocuous
E7-NM Reactive Reactive Reactive E8-NM Reactive Reactive Reactive
a = ASTM C 1293 failure criterion is 0.040% at one year b = Failure criterion is 0.06% at 1 weeks
Shaded area indicate aggregates with discrepancies (No discrepancies were noted)
234
0.00
0.04
0.08
0.12
0.16
0.20
0.24
0.28
0.32
0.36
0.00 0.04 0.08 0.12 0.16 0.20 0.24 0.28 0.32 0.36
ASTM C 1293 1-Year Expansions, %
4-w
eek
Exp
ansi
on, %
(1
N a
t 80-
deg.
)
ASTM C 1293
Failure Criterion
Modified C 1293 Failure
Criterion
Storing concrete prisms in 1N NaOH solution at 380C resulted in aggregate
classifications that are comparable to ASTM C 1293 and that correlate well with the
field performance of all aggregates investigated; however, aggregates were shown to
be more reactive when evaluated using these procedures than when tested using C
1293.
Figure 10.12: Comparison Between the Standard C 1293 procedures and Modified C 1293 Storing Prisms in 1N NaOH at
380C
235
10.4 MODIFIED C 1293: PRISMS STORED OVER WATER, AT 100% R.H. AND 600C
These procedures are identical to the standard C 1293 except that the containers
are stored at 600C instead of 380C. These procedures are expected to produce
comparable results in a shorter period of time. Mixture proportions for these tests are
the same as the standard C 1293 and are listed in Table 7.12. Results of these
procedures are included in Tables 10.13 through 10.15 and Figures 10.13 through
10.15.
Table 10.13: Expansions of Category A Aggregate Concrete Prisms Stored
Over Water, at 100% R.H., and 600C Expansion, %
Time A1-WY A2-WY A3-ID A4-ID A5-NM A6-NM A7-NC A8-VA A9-NE A10-PA1-week 0.021 0.027 0.019 0.082 0.012 0.082 0.029 0.009 0.005 0.026 2-week 0.038 0.038 0.028 0.224 0.021 0.233 0.048 0.017 0.019 0.037 4-week 0.050 0.062 0.043 0.408 0.035 0.377 0.062 0.020 0.022 0.039 8-week 0.065 0.077 0.050 0.436 0.046 0.397 0.071 0.035 0.029 0.039
13-week 0.072 0.083 0.061 0.479 0.054 0.440 0.088 0.046 0.042 0.046
Table 10.14: Expansions of Category B, C, & D Aggregate Concrete Prisms Stored Over Water, at 100% R.H., and 600C
Expansion, % Time B1-MD B2-MD B4-VA C1-SD C2-SD D2-IL
1-week 0.005 0.008 0.009 0.011 0.014 0.010 2-week 0.011 0.015 0.018 0.029 0.016 0.011 4-week 0.019 0.020 0.027 0.040 0.029 0.012 8-week 0.033 0.034 0.034 0.058 0.050 0.017
13-week 0.041 0.045 0.043 0.065 0.059 0.021
236
Table 10.15: Expansions of Category E Aggregate Concrete Prisms Stored Over Water, at 100% R.H., and 600C
Expansion, % Time E2-IA E3-NV E4-NV E6-IN E7-NM E8-NM
1-week 0.016 0.010 0.019 0.012 0.015 0.027 2-week 0.016 0.021 0.023 0.018 0.027 0.034 4-week 0.023 0.037 0.034 0.020 0.042 0.040 8-week 0.024 0.051 0.045 0.024 0.051 0.048
13-week 0.028 0.062 0.059 0.029 0.063 0.054
0.000
0.100
0.200
0.300
0.400
0.500
0.600
0 2 4 6 8 10 12 14
Time, Weeks
Exp
ansi
on, %
A1-WYA2-WYA3-IDA4-IDA5-NMA6-NMA7-NCA8-VAA9-NEA10-PA
Figure 10.13: Expansions of Category A Aggregate Concrete Prisms Stored Over Water, at 100% R.H., and 600C
237
0.000
0.010
0.020
0.030
0.040
0.050
0.060
0.070
0 2 4 6 8 10 12 14
Time, Weeks
Exp
ansi
on, %
B1-MDB2-MDB4-VAC1-SDC2-SDD2-IL
0.000
0.010
0.020
0.030
0.040
0.050
0.060
0.070
0 2 4 6 8 10 12 14
Time, Weeks
Exp
ansi
on, %
E2-IAE3-NVE4-NVE6-INE7-NME8-NM
Figure 10.14: Expansions of Category B, C, & D Aggregate Concrete Prisms Stored Over Water, at 100% R.H., and 600C
Figure 10.15: Expansions of Category E Aggregate Concrete Prisms Stored Over Water, at 100% R.H., and 600C
238
A proposed expansion limit of 0.040% after 3 months (13-weeks) of testing was used
to differentiate between reactive and innocuous aggregates. This limit was proposed
by researchers in the literature and was found to be effective with all types of
aggregates.
Category A, B, and C aggregates were all found to be reactive; Category D
aggregate was found to be innocuous; E2-IA and E6-IN of Category E were found to
be innocuous; and the E4-NV and E8-NM of Category E were found to be reactive.
These are the same conclusions obtained using the standard C 1293 procedures. Thus
these procedures generated results similar to the C 1293 procedures but in a much
shorter period of time (3 months). This is illustrated in Table 10.16.
A plot comparing these procedures to the standard C 1293 is included in Figure
10.16, where it can be noted that both testing procedures resulted in almost identical
results with an R2 value of 0.98. Thus, running the same procedures as C 1293 but
increasing the storage temperature to 600C resulted in identical results but in a much
shorter, 3-month period of time.
239
Table 10.16: Summary of Generated Results: ASTM C 1293 vs C 1293 at 600C Using 0.040% at One Year and 0.040% at
13 weeks (3 Months) as Failure Criteria Respectively
Field
Performance
100% R.H. 380C
Standarda
1N NaOH 800C
Modifiedb
A1-WY Reactive Reactive Reactive A2-WY Reactive Reactive Reactive A3-ID Reactive Reactive Reactive A4-ID Reactive Reactive Reactive
A5-NM Reactive Reactive Reactive A6-NM Reactive Reactive Reactive A7-NC Reactive Reactive Reactive A8-VA Reactive Reactive Reactive A9-NE Reactive Reactive Reactive A10-PA Reactive Reactive Reactive B1-MD Reactive Reactive Reactive B2-MD Reactive Reactive Reactive B4-VA Reactive Reactive Reactive C1-SD Reactive Reactive Reactive C2-SD Reactive Reactive Reactive D1-IL Innocuous Innocuous Innocuous E2-Ia Innocuous Innocuous Innocuous
E3-NV Reactive Reactive Reactive E4-NV Reactive Reactive Reactive E6-IN Innocuous Innocuous Innocuous
E7-NM Reactive Reactive Reactive E8-NM Reactive Reactive Reactive
a = ASTM C 1293 failure criterion is 0.040% at one year b = Failure criterion is 0.06% at 1 weeks
Shaded area indicate aggregates with discrepancies (No discrepancies were noted)
240
R2 = 0.9808
0.000.040.080.120.160.200.240.280.320.360.400.440.480.52
0.00 0.04 0.08 0.12 0.16 0.20 0.24 0.28 0.32 0.36 0.40 0.44 0.48 0.52
Standard C 1293 1-Year Expansions, %
13-w
eek
Exp
ansi
on, %
(C
129
3 at
60-
deg.
)
ASTM C 1293
Failure Criterion
Modified C 1293 Failure Criterion
Figure 10.16: Comparison Between the Standard C 1293 Procedures and Modified C 1293 at 600C
241
10.5 SUMMARY: STANDARD AND MODIFIED C 1293 TESTING PROCEDURES
A summary of the results generated with the C 1293 procedures and its
modifications is included in Table 10.19. Tables 10.17 and 10.18 include a summary
of the expansion limit criteria used with each of the investigated testing procedures.
Table 10.17: Expansion Limits for the Different C 1293 Procedures Testing Procedure Length of Testing Expansion Limit Criteria
Over Water, 100% R.H., 380C 52 weeks (one year) 0.040% Over Water, 100% R.H., 600C 13 weeks (3 months) 0.040% In 1N NaOH Solution, 380C 26 weeks (6 months) 0.040% In 1N NaOH Solution, 800C 4 weeks 0.040%
Table 10.18: Aggregate’s Reactivity Classification for the Different C 1293 Procedures
Testing Procedure Length of Testing
Slowly Reactive
%
Highly Reactive
% Over Water, 100% R.H., 380C 52 weeks (one-year) 0.040-0.070 > 0.070 Over Water, 100% R.H., 600C 13 weeks (3 months) 0.040-0.070 > 0.070 In 1N NaOH Solution, 380C 26 weeks (6 months) 0.040-0.070 > 0.070 In 1N NaOH Solution, 800C 4 weeks 0.040-0.070 > 0.070
242
Table 10.19: Summary Results of the Different C 1293 Procedures 100% R.H.
380C Standard
100% R.H
600C
1N NaOH
380C
1N NaOH
800C A1-WY H.R. (0.073%) H.R. (0.072%) S.R. (0.034%) S.R. (0.037%) A2-WY H.R. (0.107%) H.R. (0.072%) H.R. (0.092%) H.R. (0.151%) A3-ID S.R. (0.058%) S.R. (0.061%) H.R. (0.242% H.R. (0.159%) A4-ID H.R. (0.379%) H.R. (0.467%) H.R. (0.242%) H.R. (0.318%)
A5-NM S.R. (0.084%) S.R. (0.054%) H.R. (0.172%) H.R. (0.099) A6-NM H.R. (0.411%) H.R. (0.427%) H.R. (0.297%) H.R. (0.332%) A7-NC H.R. (0.085%) H.R. (0.088%) S.R. (0.066%) H.R. (0.170%) A8-VA S.R. (0.047%) S.R. (0.046%) S.R. (0.066%) H.R. (0.118%) A9-NE S.R. (0.051%) S.R. (0.042%) S.R. (0.069%) H.R. (0.209%) A10-PA S.R. (0.043%) S.R. (0.041%) S.R. (0.063%) H.R. (0.159%) B1-MD S.R. (0.040%) S.R. (0.041%) S.R. (0.045%) S.R. (0.064%) B2-MD S.R. (0.046%) S.R. (0.045%) S.R. (0.071%) H.R. (0.141%) B4-VA S.R. (0.040%) S.R. (0.043%) S.R. (0.045%) H.R. (0.097%) C1-SD S.R. (0.063%) S.R. (0.065%) S.R. (0.064%) H.R. (0.092%) C2-SD S.R. (0.053) S.R. (0.059%) S.R. (0.052%) H.R. (0.148%) D1-IL Innocuous
(0.022%) Innocuous (0.021%)
Innocuous (0.025%)
Innocuous (0.006%)
E2-Ia Innocuous (0.025%)
Innocuous (0.024%)
Innocuous (0.036%)
H.R. (0.207%)
E3-NV S.R. (0.058%) S.R. (0.062%) Innocuous S.R. (0.063%) E4-NV S.R. (0.060%) S.R. (0.059%) H.R. (0.161%) H.R. (0.189%) E6-IN Innocuous
(0.022%) Innocuous (0.029%)
S.R. (0.038%)
S.R. (0.068%)
E7-NM S.R. (0.063%) S.R. (0.063%) Innocuous H.R. (0.092%) E8-NM S.R. (0.064%) S.R. (0.044%) H.R. (0.145%) H.R. (0.176%)
H.R. = Highly Reactive ; S.R. = Slowly Reactive Note1: The numbers in Parenthesis are the expansions at the specified length of
testing in Table 12.3 Note 2: Shaded area = Results that do not correlate with standard C 1293
Expansions that correlated perfectly with field performance
243
CHAPTER ELEVEN
INVESTIGATION OF MITIGATION ALTERNATIVES USING ASTM C 1260
11.1 INTRODUCTION
ASTM C 1260 was used to evaluate the effects of Class C fly ash, Class F fly ash,
silica fume, granulated slag, calcined clay, lithium nitrate (LiNO3), air content,
permeability, and cement alkali content on the ASR reactivity of selected aggregates.
Six aggregates were chosen to conduct these investigations: A4-ID (highly reactive C
1260 and C 1293), A6-NM (Highly Reactive C 1260 and C 1293), A2-WY
(moderately reactive C 1260 and C 1293), C2-SD (slowly reactive C 1260 and C
1293), B4-VA (Slowly Reactive C 1260 and C 1293), and E2-IA (Highly Reactive C
1260 and Innocuous C 1293). The following is a presentation and a discussion of
results generated using C 1260.
11.2 EFFECT OF CLASS C FLY ASH USING C 1260
In order to investigate the effect of Class C fly ash on the expansions due to ASR,
three levels of cement replacement were investigated, namely, 20, 27.5, and 35%.
The six aggregates mentioned above were used to conduct the different mixtures
listed in Table 7.3. Results for these procedures are illustrated in Table 11.1 and
Figures 11.1 through 11.6. A comparison of the 14-day expansions of the various
replacement levels is shown in Figure 11.7.
244
Table 11.1: C 1260 Expansions Using Class C Fly Ash Expansion, %
4-Day 7-Day 11-Day 14-Day 21-Day 28-Day Aggregate ID
Class C Fly Ash
Content A2-WY A2-WY 20% 0.17 0.19 0.23 0.24 0.29 0.32 A2-WY 27.5% 0.07 0.10 0.14 0.16 0.21 0.24 A2-WY 35% 0.03 0.05 0.08 0.10 0.14 0.17
A4-ID A4-ID 20% 0.22 0.29 0.37 0.41 0.51 0.58 A4-ID 27.5% 0.07 0.12 0.19 0.22 0.31 0.37 A4-ID 35% 0.03 0.06 0.11 0.14 0.21 0.26
A6-NM A6-NM 20% 0.21 0.31 0.43 0.49 0.61 0.72 A6-NM 27.5% 0.08 0.15 0.24 0.29 0.39 0.47 A6-NM 35% 0.03 0.08 0.13 0.20 0.29 0.36
BA-VA BA-VA 20% 0.02 0.05 0.10 0.14 0.20 0.25 BA-VA 27.5% 0.03 0.04 0.06 0.08 0.12 0.15 BA-VA 35% 0.02 0.03 0.05 0.06 0.08 0.10
C2-SD C2-SD 20% 0.05 0.10 0.14 0.18 0.24 0.30 C2-SD 27.5% 0.04 0.05 0.08 0.10 0.14 0.18 C2-SD 35% 0.02 0.04 0.06 0.07 0.09 0.12
E2-IA E2-IA 20% 0.11 0.20 0.33 0.36 0.47 0.53 E2-IA 27.5% 0.02 0.11 0.20 0.22 0.29 0.35 E2-IA 35% 0.01 0.08 0.09 0.11 0.12 0.15
245
0.00
0.05
0.10
0.15
0.20
0.25
0.30
0.35
0.40
0 4 8 12 16 20 24 28 32
Time, Days
Exp
ansi
on, % A2-WY-FAC 0%
A2-WY-FAC 20%A2-WY-FAC 27.5%A2-WY-FAC 35%
0.000.100.200.300.400.500.600.700.800.901.00
0 4 8 12 16 20 24 28 32
Time, Days
Exp
ansi
on, % A4-ID-FAC 0%
A4-ID-FAC 20%A4-ID-FAC 27.5%A4-ID-FAC 35%
Figure 11.1: Effect of Class C Fly Ash on C 1260 Expansions of Aggregate A2-WY
Figure 11.2: Effect of Class C Fly Ash on C 1260 Expansions of Aggregate A4-ID
246
0.000.100.200.300.400.500.600.700.800.901.001.101.20
0 4 8 12 16 20 24 28 32
Time, Days
Exp
ansi
on, % A6-NM-FAC 0%
A6-NM-FAC 20%A6-NM-FAC 27.5%A6-NM-FAC 35%
0.00
0.05
0.10
0.15
0.20
0.25
0.30
0.35
0 4 8 12 16 20 24 28 32
Time, Days
Exp
ansi
on, %
B4-VA-FAC 0%B4-VA-FAC 20%B4-VA-FAC 27.5%B4-VA-FAC 35%
Figure 11.3: Effect of Class C Fly Ash on C 1260 Expansions of Aggregate A6-NM
Figure 11.4: Effect of Class C Fly Ash on C 1260 Expansions of Aggregate B4-VA
247
0.00
0.05
0.10
0.15
0.20
0.25
0.30
0.35
0 4 8 12 16 20 24 28 32
Time, Days
Exp
ansi
on, % C2-SD-FAC 0%
C2-SD-FAC 20%C2-SD-FAC 27.5%C2-SD-FAC 35%
0.00
0.10
0.20
0.30
0.40
0.50
0.60
0.70
0 4 8 12 16 20 24 28 32
Time, Days
Exp
ansi
on, % E2-IA-FAC 0%
E2-IA-FAC 20%E2-IA-FAC 27.5%E2-IA-FAC 35%
Figure 11.5: Effect of Class C Fly Ash on C 1260 Expansions of Aggregate C2-SD
Figure 11.6: Effect of Class C Fly Ash on C 1260 Expansions of Aggregate E2-IA
248
0.00
0.10
0.20
0.30
0.40
0.50
0.60
0.70
0.80
0.90
1.00
A6-NM A4-ID A2-WY C2-SD B4-VA E2-IA
Investigated Aggregate
14-D
ay E
xpan
sion
, %
0% Class C Fly Ash20% Class C Fly Ash27.5% Class C Fly Ash35% Class C Fly Ash
From these results, it can be noticed that the expansions decreased as the levels of
replacement of cement with Class C fly ash increased. The more Class C fly ash in
the mixture the less expansion the aggregates were showing. Thirty-five percent
Class C fly ash was needed to reduce the expansions of the slowly reactive (C2-SD
and B4-VA) aggregates below 0.10%. Thirty-five percent Class C fly ash reduced
the 14-day expansions of the highly reactive aggregates A6-NM, A4-ID, and A2-WY
by an average of 80% but was not enough to reduce them below 0.10%. These results
are illustrated in Table 11.2. As a result, it was concluded that replacing 35% of the
weight of cement with Class C fly ash is effective with slowly reactive aggregates
but not highly reactive aggregates. Class C fly ash can be used with highly reactive
aggregates to reduce the expansions caused by ASR; however, it is not capable of
reducing the expansions to levels that are considered safe and innocuous.
Figure 11.7: Comparison of the 14-Day C 1260 Expansions for the Different Aggregates and Levels of Class C Fly Ash Replacement
249
Table 11.2: Effect of Class C Fly Ash on the 14-Day C 1260 Expansions Class C Fly Ash
Replacement by Weight of Cement Aggregate ID
C 1260 14-Day
Expansion
C 1260 Classification 20% 27.5% 35%
A6-NM 0.91% H.R. H.R. H.R. H.R. A4-ID 0.79% H.R. H.R. H.R. S.R.
A2-WY 0.29% H.R. H.R. H.R. S.R. C2-SD 0.17% S.R. S.R. S.R. Innocuous B4-VA 0.15% S.R. S.R. Innocuous Innocuous E2-IA 0.42% H.R. H.R. H.R. S.R.
H.R. = Highly Reactive = C 1260 14-day expansion > 0.20% S.R. = Slowly Reactive = 0.10% < C 1260 14-day expansion < 0.20%
Innocuous = C 1260 14-day expansion < 0.10%
11.3 EFFECT OF CLASS F FLY ASH USING C 1260
In order to investigate the effect of Class F fly ash on the expansions due to ASR,
two levels of cement replacement were investigated , namely, 15 and 25%. The six
aggregates mentioned above were used to conduct the various mixtures listed in
Table 7.4. Results for these procedures are illustrated in Table 11.3 and Figures 11.8
through 11.12. A comparison of the 14-day expansions of the various replacement
levels is shown in Figure 11.13.
250
Table 11.3: C 1260 Expansions Using Class F Fly Ash Expansion, %
4-Day 7-Day 11-Day 14-Day 21-Day 28-Day Aggregate ID
Class F Fly Ash
Content A2-WY A2-WY 15% 0.06 0.12 0.16 0.18 0.24 0.28 A2-WY 20% 0.01 0.02 0.03 0.05 0.10 0.14
A4-ID A4-ID 15% 0.10 0.17 0.24 0.29 0.40 0.45 A4-ID 20% 0.02 0.03 0.07 0.10 0.17 0.22
A6-NM A6-NM 15% 0.11 0.17 0.28 0.32 0.43 0.52 A6-NM 20% 0.01 0.03 0.09 0.12 0.20 0.27
B4-VA B4-VA 15% 0.02 0.02 0.05 0.07 0.11 0.16 B4-VA 20% 0.01 0.01 0.02 0.03 0.04 0.06
C2-SD C2-SD 15% 0.03 0.06 0.10 0.13 0.18 0.23 C2-SD 20% 0.01 0.02 0.03 0.04 0.06 0.09
E2-IA E2-IA 15% 0.05 0.11 0.18 0.25 0.31 0.36 E2-IA 20% 0.01 0.02 0.03 0.05 0.08 0.10
0.00
0.05
0.10
0.15
0.20
0.25
0.30
0.35
0.40
0 4 8 12 16 20 24 28 32
Time, Days
Exp
ansi
on, % A2-WY-FAF 0%
A2-WY-FAF 15%A2-WY-FAF 25%
Figure 11.8: Effect of Class F Fly Ash on C 1260 Expansions of Aggregate A2-WY
251
0.000.100.200.300.400.500.600.700.800.901.001.10
0 4 8 12 16 20 24 28 32
Time, Days
Exp
ansi
on, % A4-ID-FAF 0%
A4-ID-FAF 15%A4-ID-FAF 25%
0.000.100.200.300.400.500.600.700.800.901.001.101.20
0 4 8 12 16 20 24 28 32
Time, Days
Exp
ansi
on, % A6-NM-FAF 0%
A6-NM-FAF 15%A6-NM-FAF 25%
Figure 11.9: Effect of Class F Fly Ash on C 1260 Expansions of Aggregate A4-ID
Figure 11.10: Effect of Class F Fly Ash on C 1260 Expansions of Aggregate A6-NM
252
0.00
0.05
0.10
0.15
0.20
0.25
0.30
0 4 8 12 16 20 24 28 32
Time, Days
Exp
ansi
on, % B4-VA-FAF 0%
B4-VA-FAF 15%B4-VA-FAF 25%
0.00
0.05
0.10
0.15
0.20
0.25
0.30
0.35
0 4 8 12 16 20 24 28 32
Time, Days
Exp
ansi
on, % C2-SD-FAF 0%
C2-SD-FAF 15%C2-SD-FAF 25%
Figure 11.11: Effect of Class F Fly Ash on C 1260 Expansions of Aggregate B4-VA
Figure 11.12: Effect of Class F Fly Ash on C 1260 Expansions of Aggregate C2-SD
253
0.00
0.10
0.20
0.30
0.40
0.50
0.60
0.70
0 4 8 12 16 20 24 28 32
Time, Days
Exp
ansi
on, % E2-IA-FAF 0%
E2-IA-FAF 15%E2-IA-FAF 25%
0.000.100.200.300.400.50
0.600.700.800.901.00
A6-NM A4-ID A2-WY C2-SD B4-VA E2-IA
Investigated Aggregate
14-D
ay E
xpan
sion
, %
0% Class F Fly Ash15% Class F Fly Ash25% Class F Fly Ash
Figure 11.14: Comparison of the 14-Day C 1260 Expansions for the Different Aggregates and Levels of Class F Fly Ash Replacement
Figure 11.13: Effect of Class F Fly Ash on C 1260 Expansions of Aggregate E2-IA
254
As the percentage of replacing cement with Class F fly ash increased the
expansions of the six aggregates decreased. Fifteen percent replacement of cement
with Class F fly ash was not effective in decreasing the 14-day expansions below
0.10% of any of the aggregates. Twenty-five percent Class F fly ash was needed to
decrease the 14-day expansions of A4-ID, A2-WY, C2-SD, and B4-VA below
0.10%. Twenty-five percent Class F fly ash was not effective in decreasing the 14-
day expansions of the highly reactive aggregate A6-NM below 0.10%. A6-NM,
when used with 25% Class F fly ash, had 14-day expansions of 0.119%, which is
about 87% lower than the expansions shown by this aggregate without fly ash
replacement (0.913%). These observations are summarized in Table 11.4
Table 11.4: Effect of Class F Fly Ash on the 14-Day C 1260 Expansions Class F Fly Ash
Replacement by Weight of Cement
Aggregate ID
C 1260 14-Day
Expansion C 1260
Classification15% 25%
A6-NM 0.91% H.R. H.R. S.R. A4-ID 0.79% H.R. H.R. S.R.
A2-WY 0.29% H.R. S.R. Innocuous C2-SD 0.17% S.R. S.R. Innocuous B4-VA 0.15% S.R. Innocuous Innocuous E2-IA 0.42% H.R. S.R. Innocuous
H.R. = Highly Reactive = C 1260 14-day expansion > 0.20% S.R. = Slowly Reactive = 0.10% < C 1260 14-day expansion < 0.20%
Innocuous = C 1260 14-day expansion < 0.10%
255
11.4 EFFECT OF SILICA FUME USING C 1260
In order to investigate the effect of silica fume on the expansions due to ASR, two
levels of cement replacement were investigated , namely, 5 and 10%. The six
aggregates mentioned above were used to conduct the various mixtures listed in
Table 7.5. Results for these procedures are illustrated in Table 11.5 and Figures
11.15 through 11.20. A comparison of the 14-day expansions of the various
replacement levels is shown in Figure 11.21.
Table 11.5: C 1260 Expansions Using Silica Fume Expansion, %
4-Day 7-Day 11-Day 14-Day 21-Day 28-Day Aggregate ID
Silica Fume
Content A2-WY A2-WY 5% 0.14 0.25 0.32 0.35 0.38 0.41 A2-WY 10% 0.02 0.05 0.10 0.13 0.20 0.26
A4-ID A4-ID 5% 0.14 0.30 0.46 0.53 0.66 0.74 A4-ID 10% 0.02 0.04 0.10 0.13 0.22 0.29
A6-NM A6-NM 5% 0.21 0.37 0.56 0.67 0.89 1.03 A6-NM 10% 0.03 0.06 0.14 0.19 0.30 0.39
B4-VA B4-VA 5% 0.02 0.05 0.09 0.13 0.21 0.27 B4-VA 10% 0.01 0.02 0.04 0.06 0.11 0.15
C2-SD C2-SD 5% 0.03 0.06 0.11 0.15 0.21 0.27 C2-SD 10% 0.00 0.02 0.05 0.08 0.13 0.17
E2-IA E2-IA 5% 0.11 0.19 0.25 0.31 0.39 0.47 E2-IA 10% 0.03 0.07 0.09 0.14 0.19 0.23
256
0.00
0.05
0.10
0.15
0.20
0.25
0.30
0.35
0.40
0.45
0 4 8 12 16 20 24 28 32
Time, Days
Exp
ansi
on, % A2-WY-SF 0%
A2-WY-SF 5%A2-WY-SF 10%
0.000.100.200.300.400.500.600.700.800.901.001.10
0 4 8 12 16 20 24 28 32
Time, Days
Exp
ansi
on, % A4-ID-SF 0%
A4-ID-SF 5%A4-ID-SF 10%
Figure 11.15: Effect of Silica Fume on C 1260 Expansions of Aggregate A2-WY
Figure 11.16: Effect of Silica Fume on C 1260 Expansions of Aggregate A4-ID
257
0.000.100.200.300.400.500.600.700.800.901.001.101.20
0 4 8 12 16 20 24 28 32
Time, Days
Exp
ansi
on, % A6-NM-SF 0%
A6-NM-SF 5%A6-NM-SF 10%
0.00
0.05
0.10
0.15
0.20
0.25
0.30
0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30
Time, Days
Exp
ansi
on, % B4-VA-SF 0%
B4-VA-SF 5%B4-VA-SF 10%
Figure 11.17: Effect of Silica Fume on C 1260 Expansions of Aggregate A6-NM
Figure 11.18: Effect of Silica Fume on C 1260 Expansions of Aggregate B4-VA
258
0.00
0.05
0.10
0.15
0.20
0.25
0.30
0.35
0 4 8 12 16 20 24 28 32
Time, Days
Exp
ansi
on, % C2-SD-SF 0%
C2-SD-SF 5%C2-SD-SF 10%
0.00
0.10
0.20
0.30
0.40
0.50
0.60
0.70
0 10 20 30
Time, Days
Exp
ansi
on, % E2-IA-SF 0%
E2-IA-SF 5%E2-IA-SF 10%
Figure 11.19: Effect of Silica Fume on C 1260 Expansions of Aggregate C2-SD
Figure 11.20: Effect of Silica Fume on C 1260 Expansions of Aggregate E2-IA
259
0.000.100.200.300.400.500.600.700.800.901.00
A6-NM A4-ID A2-WY C2-SD B4-VA E2-IA
Investigated Aggregate
14-D
ay E
xpan
sion
, %0% Silica Fume5% Silica Fume10% Silica Fume
Expansions decreased as the silica fume content increased. Replacing 10% by
weight of the cement with silica fume was needed to decrease the 14-day expansions
of the slowly reactive aggregates, B4-VA and C2-SD, below 0.10%. Ten percent
replacement of cement with silica fume decreased the 14-day expansions of the
highly reactive aggregates by an average of 70%. Still, these expansions were higher
than 0.10% and were considered excessive. The use of 5% silica fume caused a
decrease in the expansions but was not effective in decreasing the 14-day expansions
below 0.10% for any of the investigated aggregates. These observations are
summarized in Table 11.6.
Figure 11.21: Comparison of the 14-Day C 1260 Expansions for the Different Aggregates and Levels of Silica Fume Replacement
260
Table 11.6: Effect of Silica Fume on the 14-Day C 1260 Expansions Silica Fume
Replacement by Weight of Cement
Aggregate ID
C 1260 14-Day
Expansion C 1260
Classification5% 10%
A6-NM 0.91% H.R. H.R. S.R. A4-ID 0.79% H.R. H.R. S.R.
A2-WY 0.29% H.R. H.R. S.R. C2-SD 0.17% S.R. S.R. Innocuous B4-VA 0.15% S.R. S.R. Innocuous E2-IA 0.42% H.R. H.R. S.R.
H.R. = Highly Reactive = C 1260 14-day expansion > 0.20% S.R. = Slowly Reactive = 0.10% < C 1260 14-day expansion < 0.20%
Innocuous = C 1260 14-day expansion < 0.10%
11.5 EFFECT OF GRANULATED SLAG USING C 1260
In order to investigate the effect of granulated slag on the expansions due to ASR,
three levels of cement replacement were investigated , namely, 40, 55, and 70%. The
six aggregates mentioned above were used to conduct the different mixtures listed in
Table 7.6. Results for these procedures are illustrated in Table 11.7 and Figures
11.22 through 11.27. A comparison of the 14-day expansions of the various
replacement levels is shown in Figure 11.28.
261
Table 11.7: C 1260 Expansions Using Granulated Slag Expansion, %
4-Day 7-Day 11-Day 14-Day 21-Day 28-Day Aggregate ID
Granulated Slag
Content A2-WY A2-WY 40% 0.07 0.12 0.17 0.19 0.24 0.31 A2-WY 55% 0.00 0.02 0.05 0.07 0.11 0.16 A2-WY 70% -0.01 0.00 0.01 0.01 0.03 0.06
A4-ID A4-ID 40% 0.07 0.15 0.22 0.33 0.38 0.44 A4-ID 55% 0.02 0.03 0.05 0.09 0.17 0.21 A4-ID 70% 0.01 0.01 0.02 0.03 0.05 0.07
A6-NM A6-NM 40% 0.09 0.17 0.27 0.32 0.45 0.60 A6-NM 55% 0.01 0.05 0.11 0.15 0.23 0.30 A6-NM 70% -0.01 0.00 0.01 0.02 0.06 0.12
B4-VA B4-VA 40% 0.01 0.02 0.05 0.06 0.10 0.14 B4-VA 55% 0.01 0.01 0.02 0.02 0.04 0.05 B4-VA 70% 0.00 0.00 0.00 0.01 0.01 0.02
C2-SD C2-SD 40% 0.04 0.07 0.10 0.14 0.20 0.25 C2-SD 55% 0.02 0.03 0.04 0.07 0.10 0.17 C2-SD 70% -0.01 0.00 0.00 0.01 0.03 0.04
E2-IA E2-IA 40% 0.07 0.10 0.15 0.20 0.23 0.29 E2-IA 55% 0.01 0.03 0.06 0.08 0.09 0.12 E2-IA 70% 0.00 0.01 0.02 0.02 0.03 0.05
262
-0.05
0.00
0.05
0.10
0.15
0.20
0.25
0.30
0.35
0.40
0 4 8 12 16 20 24 28 32
Time, Days
Exp
ansi
on, % A2-WY-SLAG 0%
A2-WY-SLAG 40%A2-WY-SLAG 55%A2-WY-SLAG 70%
0.000.100.200.300.400.500.600.700.800.901.001.10
0 4 8 12 16 20 24 28 32
Time, Days
Exp
ansi
on, % A4-ID-SLAG 0%
A4-ID-SLAG 40%A4-ID-SLAG 55%A4-ID-SLAG 70%
Figure 11.22: Effect of Slag on C 1260 Expansions of Aggregate A2-WY
Figure 11.23: Effect of Slag on C 1260 Expansions of Aggregate A4-ID
263
-0.20
0.00
0.20
0.40
0.60
0.80
1.00
1.20
0 4 8 12 16 20 24 28 32
Time, Days
Exp
ansi
on, % A6-NM-SLAG 0%
A6-NM-SLAG 40%A6-NM-SLAG 55%A6-NM-SLAG 70%
-0.05
0.00
0.05
0.10
0.15
0.20
0.25
0.30
0 4 8 12 16 20 24 28 32
Time, Days
Exp
ansi
on, % B4-VA-SLAG 0%
B4-VA-SLAG 40%B4-VA-SLAG 55%B4-VA-SLAG 70%
Figure 11.24: Effect of Slag on C 1260 Expansions of Aggregate A6-NM
Figure 11.25: Effect of Slag on C 1260 Expansions of Aggregate B4-VA
264
-0.05
0.00
0.05
0.10
0.15
0.20
0.25
0.30
0.35
0 4 8 12 16 20 24 28 32
Time, Days
Exp
ansi
on, % C2-SD-SLAG 0%
C2-SD-SLAG 40%C2-SD-SLAG 55%C2-SD-SLAG 70%
0.00
0.10
0.20
0.30
0.40
0.50
0.60
0.70
0 10 20 30
Time, Days
Exp
ansi
on, % E2-IA-SLAG 0%
E2-IA-SLAG 40%E2-IA-SLAG 55%E2-IA-SLAG 70%
Figure 11.26: Effect of Slag on C 1260 Expansions of Aggregate C2-SD
Figure 11.27: Effect of Slag on C 1260 Expansions of Aggregate E2-IA
265
0.000.100.200.300.400.500.600.700.800.901.00
A6-NM A4-ID A2-WY C2-SD B4-VA E2-IA
Investigated Aggregate
14-D
ay E
xpan
sion
, %0% Slag40% Slag55% Slag70%Slag
An examination of these results led to the following observations:
1. As the amount of slag in the mixture increased the expansions of the six
aggregates decreased.
2. Replacing 40% of the weight of cement with slag resulted in decreasing the 14-
day expansion of B4-VA (Slowly Reactive) below 0.10%. However, 40% slag
was not effective with the other slowly reactive aggregate C2-SD that showed a
14-day expansion of 0.14% (a 21% decrease). The other aggregates A2-WY
(H.R.), A4-ID (H.R.), A6-NM (H.R.), and E2-IA (H.R.) showed 14-day
expansions higher than 0.10% at this level of slag corresponding to an average
decrease of 55%.
3. Using 55% slag in the mixtures was effective in decreasing the 14-day
expansions of A4-ID (H.R.), A2-WY (H.R.), E2-IA (H.R.), B4-VA (S.R.), and
C2-SD (S.R.) below 0.10%. Fifty-five percent slag was not effective with the
Figure 11.28: Comparison of the 14-Day C 1260 Expansions for the Different Aggregates and Levels of Slag Replacement
266
highly reactive aggregates A6-NM, which showed 14-day expansions of 0.15%
(84% lower than the expansion of mortar bars with no slag).
4. Replacing 70% of the weight of cement with slag was enough to keep the 14-day
expansions of the six aggregates well below 0.10%.
5. The above observations are summarized in Table 11.8.
Table 11.8: Effect of Granulated Slag on the 14-Day C 1260 Expansions Granulated Slag
Replacement by Weight of Cement Aggregate ID
C 1260 14-Day
Expansion
C 1260 Classification 40% 55% 70%
A6-NM 0.91% H.R. H.R. S.R. Innocuous A4-ID 0.79% H.R. H.R. Innocuous Innocuous
A2-WY 0.29% H.R. S.R. Innocuous Innocuous C2-SD 0.17% S.R. S.R. Innocuous Innocuous B4-VA 0.15% S.R. Innocuous Innocuous Innocuous E2-IA 0.42% H.R. S.R. Innocuous Innocuous
H.R. = Highly Reactive = C 1260 14-day expansion > 0.20% S.R. = Slowly Reactive = 0.10% < C 1260 14-day expansion < 0.20%
Innocuous = C 1260 14-day expansion < 0.10%
11.6 EFFECT OF CALCINED CLAY USING C 1260
In order to investigate the effect of calcined clay on the expansions due to ASR,
two levels of cement replacement were investigated, namely, 17 and 25%. The six
aggregates mentioned above were used to conduct the various mixtures listed in
Table 7.9. Results for these procedures are illustrated in Table 11.9 and Figures
11.29 through 11.34. A comparison of the 14-day expansions of the various
replacement levels is shown in Figure 11.35.
267
Table 11.9: C 1260 Expansions Using Calcined Clay Expansion, %
4-Day 7-Day 11-Day 14-Day 21-Day 28-Day Aggregate ID
Calcined Clay
Content A2-WY A2-WY 17% 0.02 0.04 0.08 0.10 0.16 0.19 A2-WY 25% 0.00 0.01 0.01 0.02 0.02 0.03
A4-ID A4-ID 17% 0.01 0.03 0.07 0.13 0.20 0.24 A4-ID 25% 0.00 0.01 0.01 0.03 0.05 0.07
A6-NM A6-NM 17% 0.01 0.04 0.09 0.16 0.25 0.31 A6-NM 25% 0.00 0.00 0.01 0.02 0.04 0.07
B4-VA B4-VA 17% 0.00 0.01 0.01 0.02 0.03 0.05 B4-VA 25% 0.00 0.00 0.00 0.01 0.01 0.03
C2-SD C2-SD 17% 0.01 0.02 0.03 0.06 0.07 0.09 C2-SD 25% 0.00 0.01 0.01 0.02 0.03 0.04
E2-IA E2-IA 17% 0.01 0.03 0.07 0.10 0.12 0.18 E2-IA 25% 0.00 0.01 0.01 0.01 0.03 0.03
268
-0.050.000.050.100.150.200.250.300.350.40
0 4 8 12 16 20 24 28 32
Time, Days
Exp
ansi
on, % A2-WY-CC 0%
A2-WY-CC 17%A2-WY-CC 25%
0.000.100.200.300.400.500.600.700.800.901.001.10
0 4 8 12 16 20 24 28 32
Time, Days
Exp
ansi
on, % A4-ID-CC 0%
A4-ID-CC 17%A4-ID-CC 25%
Figure 11.29: Effect of Calcined Clay on C 1260 Expansions of Aggregate A2-WY
Figure 11.30: Effect of Calcined Clay on C 1260 Expansions of Aggregate A4-ID
269
0.000.100.200.300.400.500.600.700.800.901.001.101.20
0 4 8 12 16 20 24 28 32
Time, Days
Expa
nsio
n, % A6-NM-CC 0%
A6-NM-CC 17%A6-NM-CC 25%
0.00
0.05
0.10
0.15
0.20
0.25
0.30
0 4 8 12 16 20 24 28 32
Time, Days
Exp
ansi
on, % B4-VA-CC 0%
B4-VA-CC 17%B4-VA-CC 25%
Figure 11.31: Effect of Calcined Clay on C 1260 Expansions of Aggregate A6-NM
Figure 11.32: Effect of Calcined Clay on C 1260 Expansions of Aggregate B4-VA
270
0.00
0.05
0.10
0.15
0.20
0.25
0.30
0.35
0 4 8 12 16 20 24 28 32
Time, Days
Exp
ansi
on, % C2-SD-CC 0%
C2-SD-CC 17%C2-SD-CC 25%
0.00
0.10
0.20
0.30
0.40
0.50
0.60
0.70
0 4 8 12 16 20 24 28 32
Time, Days
Exp
ansi
on, % E2-IA-CC 0%
E2-IA-CC 17%E2-IA-CC 25%
Figure 11.33: Effect of Calcined Clay on C 1260 Expansions of Aggregate C2-SD
Figure 11.34: Effect of Calcined Clay on C 1260 Expansions of Aggregate E2-IA
271
0.000.100.200.300.400.500.600.700.800.901.00
A6-NM A4-ID A2-WY C2-SD B4-VA E2-IA
Investigated Aggregate
14-D
ay E
xpan
sion
, %0% Calcined Clay17% Calcined Clay25% Calcined Clay
In order to determine whether the remaining Category E aggregates react in a
comparable manner to the mitigation alternatives, calcined clay was used to replace
17 and 25% of the cement of mortar bars formed with Category E aggregates.
Results are presented in Table 11.10 and Figure 11.36.
Figure 11.35: Comparison of the 14-Day C 1260 Expansions for the Different Aggregates and Levels of Calcined Clay Replacement
272
Table 11.10: Category E C 1260 Expansions Using Calcined Clay Expansion, %
4-Day 7-Day 11-Day 14-Day 21-Day 28-Day Aggregate ID
Calcined Clay
Content E2-IA E2-IA 17% 0.01 0.03 0.07 0.10 0.12 0.18 E2-IA 25% 0.00 0.01 0.01 0.01 0.03 0.03
E4-NV E4-NV 17% 0.02 0.05 0.09 0.13 0.19 0.22 E4-NV 25% 0.01 0.02 0.02 0.02 0.03 0.04
E6-IN E6-IN 17% 0.01 0.05 0.09 0.11 0.15 0.20 E6-IN 25% 0.00 0.01 0.01 0.01 0.02 0.02
E8-NM E8-NM 17% 0.01 0.04 0.07 0.12 0.20 0.25 E8-NM 25% 0.01 0.01 0.02 0.02 0.03 0.04
0.00
0.05
0.10
0.15
0.20
0.25
0.30
0.35
0.40
0.45
E2-IA E4-NV-CC E6-IN E8-NM
Investigated Aggregate
14-D
ay E
xpan
sion
, %
0% Calcined Clay17% Calcined Clay25% Calcined Clay
Figure 11.36: Effect of Calcined Clay on the 14-Day C 1260 Expansions of Category E Aggregates
273
An examination of these results generated the following observations:
1. As noticed before, the expansion decreased as the amount of calcined clay in the
mixtures increased.
2. Using 17% calcined clay to replace cement by weight was effective in decreasing
the 14-day expansion of the slowly reactive aggregates, B4-VA and C2-SD, and
the highly reactive aggregates A2-WY and E2-IA below 0.10%. However, 17%
calcined clay was not effective with the highly reactive aggregates A4-ID and
A6-NM, both of which showed 14-day expansions higher than 0.10%. Fourteen-
day expansions of mortar bars made with 17% calcined clay were lower than the
expansions of mortar bar with no calcined clay. For A4-ID (H.R.) and A6-NM
(H.R.), the 14-day expansions were about 83% lower.
3. Replacing 25% of the weight of cement with calcined clay was effective in
decreasing the 14-day expansions of the six aggregates well below 0.10%.
4. Category E aggregates reacted in a similar manner to Category A aggregates.
5. The observations noted above are summarized in Table 11.11.
Table 11.11: Effect of Calcined Clay on the 14-Day C 1260 Expansions Calcined Clay
Replacement by Weight of Cement
Aggregate ID
C 1260 14-Day
Expansion C 1260
Classification17% 25%
A6-NM 0.91% H.R. S.R. Innocuous A4-ID 0.79% H.R. S.R. Innocuous
A2-WY 0.29% H.R. S.R. Innocuous C2-SD 0.17% S.R. Innocuous Innocuous B4-VA 0.15% S.R. Innocuous Innocuous E2-IA 0.42% H.R. S.R. Innocuous E4-NV 0.25% H.R. S.R. Innocuous E6-IN 0.25% H.R. S.R. Innocuous
E8-NM 0.36% H.R. S.R. Innocuous H.R. = Highly Reactive = C 1260 14-day expansion > 0.20% S.R. = Slowly Reactive = 0.10% < C 1260 14-day expansion < 0.20%
Innocuous = C 1260 14-day expansion < 0.10%
274
11.7 EFFECT OF AIR ENTRAINMENT USING C 1260
In order to investigate the effect of air entrainment on the expansions due to ASR,
two ranges of entrained air were investigated, namely, between 2 and 4% labeled AE
4% and between 6 and 8% labeled AE 8%. In this section entrained air refers to total
air content reduced by the entrapped air content. The six aggregates mentioned above
were used to conduct the different mixtures listed in Table 7.8. Results for these
procedures are illustrated in Table 11.12 and Figures 11.37 through 11.42. A
comparison of the 14-day expansions of the different air levels is shown in Figure
11.43.
Table 11.12: C 1260 Expansions Using Air Entrainment Expansion, %
4-Day 7-Day 11-Day 14-Day 21-Day 28-Day Aggregate ID
Air Entrainment
Content A2-WY A2-WY 4% 0.06 0.10 0.12 0.13 0.15 0.16 A2-WY 8% 0.05 0.08 0.10 0.11 0.12 0.14
A4-ID A4-ID 4% 0.16 0.26 0.35 0.37 0.42 0.46 A4-ID 8% 0.15 0.24 0.33 0.36 0.40 0.44
A6-NM A6-NM 4% 0.21 0.28 0.44 0.48 0.54 0.59 A6-NM 8% 0.21 0.33 0.43 0.47 0.53 0.57
B4-VA B4-VA 4% 0.02 0.04 0.06 0.08 0.11 0.13 B4-VA 8% 0.02 0.04 0.07 0.08 0.11 0.13
C2-SD C2-SD 4% 0.04 0.07 0.10 0.12 0.15 0.18 C2-SD 8% 0.04 0.07 0.10 0.12 0.16 0.19
E2-IA E2-IA 4% 0.07 0.11 0.13 0.14 0.15 0.16 E2-IA 8% 0.06 0.09 0.1 0.12 0.14 0.15
275
0.00
0.05
0.10
0.15
0.20
0.25
0.30
0.35
0.40
0 4 8 12 16 20 24 28 32
Time, Days
Exp
ansi
on, % A2-WY-AE 0%
A2-WY-AE 4%
A2-WY-AE 8%
0.000.100.200.300.400.500.600.700.800.901.001.10
0 4 8 12 16 20 24 28 32
Time, Days
Exp
ansi
on, % A4-ID-AE 0%
A4-ID-AE 4%
A4-ID-AE 8%
Figure 11.37: Effect of Air Entrainment on C 1260 Expansions of Aggregate A2-WY
Figure 11.38: Effect of Air Entrainment on C 1260 Expansions of Aggregate A4-ID
276
0.000.100.200.300.400.500.600.700.800.901.001.101.20
0 4 8 12 16 20 24 28 32
Time, Days
Exp
ansi
on, % A6-NM-AE 0%
A6-NM-AE 4%
A6-NM-AE 8%
0.00
0.05
0.10
0.15
0.20
0.25
0.30
0 4 8 12 16 20 24 28 32
Time, Days
Exp
ansi
on, % B4-VA-AE 0%
B4-VA-AE 4%B4-VA-AE 8%
Figure 11.39: Effect of Air Entrainment on C 1260 Expansions of Aggregate A6-NM
Figure 11.40: Effect of Air Entrainment on C 1260 Expansions of Aggregate B4-VA
277
0.00
0.05
0.10
0.15
0.20
0.25
0.30
0.35
0 4 8 12 16 20 24 28 32
Time, Days
Exp
ansi
on, % C2-SD-AE 0%
C2-SD-AE 4%
C2-SD-AE 8%
0.00
0.10
0.20
0.30
0.40
0.50
0 4 8 12 16 20 24 28 32
Time, Days
Exp
ansi
on, % E2-IA-AE 0%
E2-IA-AE 4%
E2-IA-AE 8%
Figure 11.41: Effect of Air Entrainment on C 1260 Expansions of Aggregate C2-SD
Figure 11.42: Effect of Air Entrainment on C 1260 Expansions of Aggregate E2-IA
278
0.00
0.10
0.20
0.30
0.40
0.50
0.60
0.70
0.80
0.90
1.00
A6-NM A4-ID A2-WY C2-SD B4-VA E2-IA
Investigated Aggregate
14-D
ay E
xpan
sion
, % 0% Air Entrained2-4% Air Entrained6-8% Air Entrained
An examination of these results generated the following observations:
1. Using between 2 and 4% entrained air (Total Air – Entrapped Air) in the
mixtures caused the 14-day expansions to decrease by 66% for A2-WY, 53% for
A4-ID, 48% for A6-NM, 44% for B4-VA, and 32% for C2-SD. However, the 14-
day expansions for the six aggregates were higher than 0.10%, with the exception
of B4-VA that showed a 14-day expansion of 0.081%. Table 11.13 summarizes
these observations.
2. Increasing the entrained air content from between 2 and 4% to between 6 and 8%
showed little benefit. Fourteen-day expansions of mortar bars with 4% entrained
air were comparable and very close to those with 8% entrained air. This is
probably caused by the increase in porosity that results from increasing the air
content. This means that the beneficial effects of air entrainment can be achieved
by using 2 to 4% air.
Figure 11.43: Comparison of the 14-Day C 1260 Expansions for the Different Entrained Air Levels
279
Table 11.13: Effect of Air Entrainment on the 14-Day C 1260 Expansions Calcined Clay
Replacement by Weight of Cement
Aggregate ID
C 1260 14-Day
Expansion C 1260
Classification17% 25%
A6-NM 0.91% H.R. H.R. H.R. A4-ID 0.79% H.R. H.R. H.R.
A2-WY 0.29% H.R. S.R. S.R. C2-SD 0.17% S.R. S.R. S.R. B4-VA 0.15% S.R. Innocuous Innocuous E2-IA 0.42% H.R. S.R. S.R.
H.R. = Highly Reactive = C 1260 14-day expansion > 0.20% S.R. = Slowly Reactive = 0.10% < C 1260 14-day expansion < 0.20%
Innocuous = C 1260 14-day expansion < 0.10%
11.8 EFFECT OF WATER-CEMENT RATIO USING C 1260 In order to investigate the effect water-cement ratio on the expansions due to
ASR, the water-cement ratio was varied between 0.35 and 0.65. The investigated
water-cement ratios were 0.35, 0.47, 0.55, and 0.65. The water-cement ratio was
varied by varying the amount of water in the mixture while keeping all other
constituents constant. Mixture proportions are listed in Table 7.10. Results for these
procedures are illustrated in Table 11.14 and Figures 11.44 through 11.48. A
comparison of the 14-day expansions of the various water-cement ratios is shown in
Figure 11.49.
280
Table 11.14: C 1260 Expansions Using Various Water-Cement Ratios Expansion, %
4-Day 7-Day 11-Day 14-Day 21-Day 28-Day Aggregate ID
Water-Cement Ratio A2-WY
A2-WY 0.35 0.16 0.24 0.32 0.35 0.42 0.47 A2-WY 0.55 0.17 0.21 0.23 0.25 0.27 0.29 A2-WY 0.65 0.13 0.15 0.17 0.18 0.20 0.22
A4-ID A4-ID 0.35 0.64 0.88 1.04 1.11 1.22 1.29 A4-ID 0.55 0.52 0.68 0.80 0.84 0.91 0.96 A4-ID 0.65 0.36 0.48 0.56 0.60 0.65 0.69
A6-NM A6-NM 0.35 0.62 0.84 1.03 1.13 1.30 1.42 A6-NM 0.55 0.48 0.68 0.83 0.90 0.99 1.06 A6-NM 0.65 0.29 0.43 0.53 0.57 0.62 0.68
B4-VA B4-VA 0.35 0.03 0.06 0.12 0.17 0.26 0.36 B4-VA 0.55 0.03 0.06 0.10 0.13 0.17 0.23 B4-VA 0.65 0.03 0.06 0.09 0.11 0.15 0.20
C2-SD C2-SD 0.35 0.06 0.09 0.16 0.20 0.29 0.38 C2-SD 0.55 0.03 0.06 0.09 0.11 0.16 0.21 C2-SD 0.65 0.03 0.05 0.07 0.09 0.13 0.18
281
0.000.050.100.150.200.250.300.350.400.450.50
0 4 8 12 16 20 24 28 32
Time, Days
Exp
ansi
on, % A2-WY-W/C 0.35
A2-WY-W/C 0.47A2-WY-W/C 0.55A2-WY-W/C 0.65
0.00
0.20
0.40
0.60
0.80
1.00
1.20
1.40
0 4 8 12 16 20 24 28 32
Time, Days
Exp
ansi
on, %
A4-ID-W/C 0.35A4-ID-W/C 0.47A4-ID-W/C 0.55A4-ID-W/C 0.65
Figure 11.44: Effect of W/C on C 1260 Expansions of Aggregate A2-WY
Figure 11.45: Effect of W/C on C 1260 Expansions of Aggregate A4-ID
282
0.00
0.20
0.40
0.60
0.80
1.00
1.20
1.40
1.60
0 4 8 12 16 20 24 28 32
Time, Days
Exp
ansi
on, %
A6-NM-W/C 0.35A6-NM-W/C 0.47A6-NM-W/C 0.55A6-NM-W/C 0.65
0.00
0.05
0.10
0.15
0.20
0.25
0.30
0.35
0.40
0 4 8 12 16 20 24 28 32
Time, Days
Exp
ansi
on, %
BA-VA-W/C 0.35BA-VA-W/C 0.47BA-VA-W/C 0.55BA-VA-W/C 0.65
Figure 11.46: Effect of W/C on C 1260 Expansions of Aggregate A6-NM
Figure 11.47: Effect of W/C on C 1260 Expansions of Aggregate B4-VA
283
0.00
0.05
0.10
0.15
0.20
0.25
0.30
0.35
0.40
0 4 8 12 16 20 24 28 32
Time, Days
Exp
ansi
on, %
C2-SD-W/C 0.35C2-SD-W/C 0.47C2-SD-W/C 0.55C2-SD-W/C 0.65
0.00
0.20
0.40
0.60
0.80
1.00
1.20
A6-NM A4-ID A2-WY C2-SD B4-VA
Investigated Aggregate
14-D
ay E
xpan
sion
, %
W/C = 0.35W/C = 0.47W/C = 0.55W/C = 0.65
Figure 11.48: Effect of W/C on C 1260 Expansions of Aggregate C2-SD
Figure 11.49: Comparison of the 14-Day C 1260 Expansions for the Different Water-Cement Ratios
284
The investigated water-cement (W/C) ratios were 0.35, 0.47 (standard), 0.55, and
0.65. The W/C was changed by varying the water content of the mixture. It was
predicted that by increasing the W/C, the permeability would increase and vice versa.
The results indicate that the expansions at a W/C of 0.35 for all six aggregates were
higher than the expansions at the other W/C ratios. Thus, as the W/C decreased from
0.47 (standard C 1260 test requirement) to 0.35 the expansions increased by 26% for
A2-WY, 40% for A4-ID, 24% for A6-NM, 19% for B4-VA, and 14% for C2-SD
(about 25% on average). Even though the permeability was decreased the expansion
increased. This might be explained by the fact that as the W/C is decreased to 0.35
the porosity decreases and becomes more compact and uniform. Very little space is
left for the gel to form. If the same amount of gel that was formed at a W/C of 0.47 is
formed at 0.35, the bars with W/C of 0.35 will expand more. As a result, decreasing
the permeability by decreasing the water-cement ratio (water content) had a
detrimental effect on the expansions caused by ASR. Decreasing the W/C resulted in
an increase in expansions.
As the water-cement ratio increased from 0.35 to 0.65, the expansions of the five
aggregates decreased. Mortar bars with a water-cement ratio of 0.35 showed the
highest expansions, followed by the bars with water-cement ratio of 0.47, than the
bars with water-cement ratio of 0.55, and finally the bars with water-cement ratio of
0.65. It should be noted that all 14-day expansions for all six aggregates at all water-
cement ratios were well above 0.10%. As a result, it can be concluded that as the
water-cement ratio of the mortar bars increased from 0.35 to 0.65, their C 1260
expansions decreased.
285
11.9 EFFECT OF LITHIUM NITRATE (LiNO3) USING C 1260
In order to investigate the effect of LiNO3 on the expansions due to ASR, a
volume of the mixing water was replaced with a LiNO3 solution. The replaced
volume of water was equal to 85% of the volume of LiNO3 added. The dosages of
LiNO3 were as follows:
1. 3.5 liters of LiNO3 per 1 kg of Na2O in the mixture (21 g of LiNO3 for our
mixtures)
2. 4.6 liters of LiNO3 per 1 kg of Na2O in the mixture (28 g of LiNO3 for our
mixtures)
3. 10 liters of LiNO3 per 1 kg of Na2O in the mixture (60 g of LiNO3 for our
mixtures)
Mixture proportions are listed in Table 7.7. Results for these procedures are
illustrated in Table 11.15 and Figures 11.50 through 11.55. A comparison of the 14-
day expansions of the various lithium dosages is shown in Figure 11.56.
286
Table 11.15: C 1260 Expansions Using Different LiNO3 Dosages Expansion, %
4-Day 7-Day 11-Day 14-Day 21-Day 28-DayAggregate ID
Lithium Content A2-WY
A2-WY 21 g 0.02 0.04 0.07 0.09 0.15 0.18 A2-WY 28 g 0.01 0.03 0.05 0.07 0.13 0.17 A2-WY 60 g 0.00 0.01 0.02 0.02 0.05 0.08
A4-ID A4-ID 21 g 0.15 0.27 0.44 0.49 0.59 0.66 A4-ID 28 g 0.07 0.19 0.38 0.46 0.59 0.66 A4-ID 60 g 0.01 0.03 0.10 0.16 0.27 0.33
A6-NM A6-NM 21 g 0.17 0.31 0.45 0.55 0.73 0.83 A6-NM 28 g 0.11 0.26 0.43 0.55 0.77 0.88 A6-NM 60 g 0.02 0.08 0.20 0.28 0.42 0.47
B4-VA B4-VA 21 g 0.01 0.02 0.07 0.09 0.18 0.22 B4-VA 28 g 0.01 0.02 0.05 0.07 0.15 0.21 B4-VA 60 g 0.01 0.01 0.02 0.03 0.05 0.08
C2-SD C2-SD 21 g 0.02 0.05 0.10 0.15 0.23 0.28 C2-SD 28 g 0.02 0.04 0.06 0.10 0.17 0.21 C2-SD 60 g 0.00 0.01 0.02 0.03 0.05 0.07
E2-IA E2-IA 21 g 0.02 0.05 0.06 0.08 0.10 0.14 E2-IA 28 g 0.01 0.04 0.05 0.07 0.15 0.18 E2-IA 60 g 0.00 0.01 0.03 0.04 0.04 0.07
287
0.00
0.05
0.10
0.15
0.20
0.25
0.30
0.35
0.40
0 4 8 12 16 20 24 28 32
Time, Days
Exp
ansi
on, % A2-WY-Lithium 0g
A2-WY-Lithium21gA2-WY-Lithium28g
0.000.100.200.300.400.500.600.700.800.901.001.10
0 4 8 12 16 20 24 28 32
Time, Days
Exp
ansi
on, % A4-ID-Lithium 0 g
A4-ID-Lithium 21gA4-ID-Lithium 28gA4-ID-Litium 60g
Figure 11.50: Effect of LiNO3 on C 1260 Expansions of Aggregate A2-WY
Figure 11.51: Effect of LiNO3 on C 1260 Expansions of Aggregate A4-ID
288
0.000.100.200.300.400.500.600.700.800.901.001.101.20
0 4 8 12 16 20 24 28 32
Time, Days
Exp
ansi
on, % A6-NM-Lithium 0 g
A6-NM-Lithium21gA6-NM-Lithium28g
0.00
0.05
0.10
0.15
0.20
0.25
0.30
0 4 8 12 16 20 24 28 32
Time, Days
Exp
ansi
on, % B4-VA-Lithium 0 g
B4-VA-Lithium 21gB4-VA-Lithium 28gB4-VA-Litium 60g
Figure 11.52: Effect of LiNO3 on C 1260 Expansions of Aggregate A6-NM
Figure 11.53: Effect of LiNO3 on C 1260 Expansions of Aggregate B4-VA
289
0.00
0.05
0.10
0.15
0.20
0.25
0.30
0.35
0 4 8 12 16 20 24 28 32
Time, Days
Exp
ansi
on, % C2-SD-Lithium 0 g
C2-SD-Lithium 21gC2-SD-Lithium 28gC2-SD-Litium 60g
0.00
0.10
0.20
0.30
0.40
0.50
0.60
0.70
0 4 8 12 16 20 24 28 32
Time, Days
Exp
ansi
on, % E2-IA-Lithium 0 g
E2-IA-Lithium 21gE2-IA-Lithium 28gE2-IA-Litium 60g
Figure 11.54: Effect of LiNO3 on C 1260 Expansions of Aggregate C2-SD
Figure 11.55: Effect of LiNO3 on C 1260 Expansions of Aggregate E2-IA
290
0.000.100.200.300.400.500.600.700.800.901.00
A6-NM A4-ID A2-WY C2-SD B4-VA E2-IA
Investigated Aggregate
14-D
ay E
xpan
sion
, %0g LiNO321g LiNO328g LiNO360g LiNO3
It was suggested in the literature (Starks, 1993; McKeen, 1998) that ASTM C
1260 is not a suitable test for investigating the effect of LiNO3 on ASR because of
the leaching of LiNO3 from the mortar bars to the NaOH solution. Still the
procedures were performed. As can be seen from the results, expansions decreased as
LiNO3 replaced part of the mixture water. The addition of 21g LiNO3 was effective
in decreasing the 14-day expansions of only A2-WY below 0.10%. Twenty-eight
grams of LiNO3 was effective with A2-WY (H.R.), B4-VA (S.R.), and C2-SD (S.R.)
but not A4-ID (H.R.) and A6-NM (H.R.). Sixty grams of LiNO3 was also not
effective with the highly reactive A4-ID and A6-NM. These observations are
summarized in Table 11.16.
It should be noted that as time progressed, the difference between the expansions
of mortar bars with 21g and 28g of LiNO3 became smaller. In the case of A4-ID and
A6-NM the 14-day, 21-day, and 28-day expansions of bars with 28g of LiNO3 were
Figure 11.56: Comparison of the 14-Day C 1260 Expansions for the Different LiNO3 Dosages
291
almost the same as the expansions of bars with 21g of LiNO3 (Figures 10.44 through
10.48). This might be explained by the leaching theory that can be stated as follows:
As time progresses, LiNO3 starts leaching out of the mortar bars and into the
solution. Less LiNO3 is present in the bars for suppressing the ASR reaction, which
results in increased expansions. That is why the expansion of mortar bars with 28g
LiNO3 increase and become closer to the expansions of bars with 21g LiNO3.
Table 11.16: Effect of LiNO3 on the 14-Day C 1260 Expansions LiNO3 Weight
Aggregate ID
C 1260 14-Day
Expansion
C 1260 Classification 21 g 28 g 60 g
A6-NM 0.91% H.R. H.R. H.R. H.R. A4-ID 0.79% H.R. H.R. H.R. S.R.
A2-WY 0.29% H.R. Innocuous Innocuous Innocuous C2-SD 0.17% S.R. S.R. Innocuous Innocuous B4-VA 0.15% S.R. Innocuous Innocuous Innocuous E2-IA 0.42% H.R. Innocuous Innocuous Innocuous
H.R. = Highly Reactive = C 1260 14-day expansion > 0.20% S.R. = Slowly Reactive = 0.10% < C 1260 14-day expansion < 0.20%
Innocuous = C 1260 14-day expansion < 0.10%
292
11.10 SUMMARY OF MITIGATION ALTERNATIVE INVESTIGATION USING C 1260
ASTM C 1260 was used to evaluate the effectiveness of the mitigation
alternatives using a 14-day expansion of 0.10% as a criterion. Table 11.17 includes a
summary of this evaluation. As can be seen from this table, the only alternatives that
were effective with all six aggregates are the use of 70% granulated slag and 25%
calcined clay. Twenty-five percent Class F fly ash and 55% slag were effective with
four out of the six aggregates except for the very reactive aggregate A6-NM (14-day
expansion of 0.91%). Alternatives that were effective with slowly reactive
aggregates (B4-VA and C2-SD) are the use of 35% Class C fly ash, 15% and 25%
Class F fly ash, 10% silica fume, 40% and 70% slag, 17% and 25% calcined clay,
and 60g of LiNO3. Alternatives that were effective with the highly reactive aggregate
A2-WY are the use of 25% Class F fly ash, 55% and 70% slag, 25% calcined clay,
and 60g of LiNO3. Alternatives that were effective with the highly reactive aggregate
A6-NM are the use of 70% slag and 25% calcined clay. It seems that different levels
of aggregate reactivity require different mitigation alternatives. It should be noted
that aggregate E2-IA, which was classified as highly reactive when tested in
accordance to C 1260 but innocuous when tested according to C 1293, exhibited
identical reaction to the mitigation alternatives as the reaction of A2-WY. The 14-
day expansions of E2-IA and A2-WY were 0.42% and 0.29% respectively, which
puts them in the same reactivity category.
293
Table 11.17: Effectiveness of the Mitigation Alternatives Using the 14-day of 0.10% Criteria
Aggregate, 14-day expansion, (C 1260 Classification)
Cementitious Material
Replacement Level by
Weight of Cement
A6-NM 0.91% (H.R.)
A4-ID 0.79% (H.R.)
A2-WY 0.29% (H.R.)
C2-SD 0.17% (S.R.)
B4-VA 0.15% (S.R.)
E2-IA 0.42% (H.R.)
20% H.R. H.R. H.R. S.R. S.R. H.R. 27.5% H.R. H.R. H.R. S.R. Innocuous H.R. Class C
Fly Ash 35% H.R. S.R. S.R. Innocuous Innocuous S.R. 15% H.R. H.R. S.R. S.R. Innocuous S.R. Class F
Fly Ash 25% S.R. S.R. Innocuous Innocuous Innocuous Innocuous 5% H.R. H.R. H.R. S.R. S.R. H.R. Silica
Fume 10% S.R. S.R. S.R. Innocuous Innocuous S.R. 40% H.R. H.R. S.R. S.R. Innocuous S.R. 55% S.R. Innocuous Innocuous Innocuous Innocuous Innocuous
Granulated Slag
70% Innocuous Innocuous Innocuous Innocuous Innocuous Innocuous 17% S.R. S.R. S.R. Innocuous Innocuous S.R. Calcined
Clay 25% Innocuous Innocuous Innocuous Innocuous Innocuous Innocuous Aggregate, 14-day expansion, (C 1260 Classification)
Chemical Material Dosage
A6-NM 0.91% (H.R.)
A4-ID 0.79% (H.R.)
A2-WY 0.29% (H.R.)
C2-SD 0.17% (S.R.)
B4-VA 0.15% (S.R.)
E2-IA 0.42% (H.R.)
21 g H.R. H.R. Innocuous S.R. Innocuous Innocuous 28 g H.R. H.R. Innocuous Innocuous Innocuous Innocuous
Lithium Nitrate
60 g H.R. S.R. Innocuous Innocuous Innocuous Innocuous 4% H.R. H.R. S.R. S.R. Innocuous S.R. Entrained
Air 8% H.R. H.R. S.R. S.R. Innocuous S.R. H.R. = Highly Reactive = C 1260 14-day expansion > 0.20% S.R. = Slowly Reactive = 0.10% < C 1260 14-day expansion < 0.20%
Innocuous = C 1260 14-day expansion < 0.10%
294
11.11 EFFECTIVENESS OF THE MITIGATION ALTERNATIVES AT DIFFERENT CEMENT ALKALI CONTENT
It has been suggested by Stark (1993) and investigated by this research that
changing the normality of the NaOH solution in the C 1260 test can be used to
determine the reactivity of aggregates at a certain cement alkali level corresponding
to the solution normality (Section 4.18.2, eq. 4.4, Section 9.7). As the normality of
the solution decreases, the equivalent alkali content of the mortar bars decreases, and
the need for mitigation decreases. This concept was investigated using mitigation
alternatives for the following purposes:
1. Determine the effect of decreasing the NaOH solution normality on the
effectiveness of mitigation alternatives.
2. Mitigate the excessive expansions of highly reactive aggregates by using low
alkali content and a mitigation alternative.
The mitigation methods used for these procedures were Class C fly ash, Class F
fly ash, granulated slag, silica fume, calcined clay, and air entrainment in
combination with the highly reactive aggregate A6-NM. The use of LiNO3 was not
evaluated because it proved to be effective with highly reactive aggregates at
reasonable levels. The investigated NaOH solution normalities were the standard
1.0N corresponding to 1.50% Na2Oequiv., 0.75N corresponding to 1.15% Na2Oequiv.,
0.5N corresponding to 0.80% Na2Oequiv., and 0.35N corresponding to 0.6%
Na2Oequiv..
Results of these procedures are presented in Table 11.18 and Figures 11.57
through 11.68.
295
Table 11.18: Expansion Results of A6-NM Used with Mitigation Alternatives at Different Cement Alkali Content
Expansion, % 4-Day 7-Day 11-Day 14-Day 21-Day 28-Day Mixture ID
Class C Fly Ash A6-NM-0.75N-FAC 25% 0.08 0.15 0.23 0.26 0.34 0.41 A6-NM-0.75N-FAC 35% 0.02 0.06 0.08 0.11 0.17 0.22 A6-NM-0.5N-FAC 25% 0.01 0.03 0.05 0.07 0.10 0.12 A6-NM-0.5N-FAC 35% 0.00 0.01 0.01 0.02 0.03 0.05 A6-NM-0.35N-FAC 25% 0.00 0.02 0.04 0.05 0.09 0.10 A6-NM-0.35N-FAC 35% 0.00 0.00 0.01 0.01 0.02 0.02 Class F Fly Ash A6-NM-0.75N-FAF 15% 0.06 0.11 0.19 0.23 0.31 0.38 A6-NM-0.75N-FAF 20% 0.02 0.04 0.09 0.12 0.19 0.25 A6-NM-0.5N-FAF 15% 0.01 0.03 0.07 0.09 0.13 0.15 A6-NM-0.5N-FAF 20% 0.00 0.01 0.02 0.02 0.05 0.06 A6-NM-0.35N-FAF 15% 0.00 0.03 0.07 0.09 0.13 0.15 A6-NM-0.35N-FAF 20% 0.00 0.00 0.01 0.01 0.03 0.03 Granulated Slag A6-NM-0.75N-SL 25% 0.24 0.38 0.54 0.61 0.74 0.85 A6-NM-0.75N-SL 50% 0.02 0.03 0.09 0.12 0.18 0.25 A6-NM-0.5N-SL 25% 0.02 0.10 0.18 0.23 0.32 0.37 A6-NM-0.5N-SL 50% 0.00 0.00 0.01 0.01 0.02 0.03 A6-NM-0.35N-SL 25% 0.01 0.08 0.16 0.21 0.33 0.38 A6-NM-0.35N-SL 50% 0.00 0.00 0.00 0.00 0.01 0.02 Silica Fume A6-NM-0.75N-SF 5% 0.20 0.39 0.62 0.75 0.99 1.13 A6-NM-0.75N-SF 10% 0.03 0.09 0.20 0.26 0.42 0.57 A6-NM-0.5N-SF 5% 0.02 0.10 0.21 0.27 0.40 0.47 A6-NM-0.5N-SF 10% 0.00 0.01 0.01 0.02 0.05 0.08 A6-NM-0.35N-SF 5% 0.01 0.08 0.18 0.24 0.39 0.47 A6-NM-0.35N-SF 10% 0.00 0.00 0.01 0.01 0.03 0.04 Air Entrainment A6-NM-0.75N-AE 4% 0.17 0.27 0.38 0.42 0.48 0.52 A6-NM-0.5N-AE 4% 0.05 0.11 0.17 0.21 0.27 0.29 A6-NM-0.35N-AE 4% 0.03 0.07 0.12 0.14 0.20 0.22
296
Table 11.18: Expansion Results of A6-NM Used with Mitigation Alternatives at Different Cement Alkali Content (Cont’d)
Expansion, % 4-Day 7-Day 11-Day 14-Day 21-Day 28-Day
Mixture ID Calcined Clay A6-NM-0.75N-CC 17% 0.01 0.03 0.07 0.12 0.15 0.20
A6-NM-0.5N-CC 17% 0.00 0.00 0.01 0.03 0.05 0.08 A6-NM-0.35N-CC 17% 0.00 0.00 0.01 0.01 0.02 0.02
0.000.100.200.300.400.500.600.700.800.901.001.101.20
0 4 8 12 16 20 24 28 32
Time, Days
Exp
ansi
on, %
A6-NM-1N-FAC 0%
A6-NM-1N- FAC 35%
A6-NM-0.75N-FAC 25%
A6-NM-0.75N-FAC 35%
A6-NM-0.5N-FAC 25%
A6-NM-0.5N-FAC 35%
A6-NM-0.35N-FAC 25%
A6-NM-0.35N-FAC 35%
Figure 11.57: Effect of Class C Fly Ash at Different Cement Alkali Contents for the Highly Reactive A6-NM
297
0.000.100.200.300.400.500.600.700.800.901.001.101.20
0 4 8 12 16 20 24 28 32
Time, Days
Exp
ansi
on, %
A6-NM-1N-FAF 0%
A6-NM-1N- FAF 25%
A6-NM-0.75N-FAF 15%
A6-NM-0.75N-FAF 20%
A6-NM-0.5N-FAF 15%
A6-NM-0.5N-FAF 20%
A6-NM-0.35N-FAF 15%
A6-NM-0.35N-FAF 20%
0.000.100.200.300.400.500.600.700.800.901.001.101.20
0 4 8 12 16 20 24 28 32Time, Days
Exp
ansi
on, %
A6-NM-1N-SL 0%
A6-NM-1N- SL 55%
A6-NM-0.75N-SL 25%
A6-NM-0.75N-SL 50%
A6-NM-0.5N-SL 25%
A6-NM-0.5N-SL 50%
A6-NM-0.35N-SL 25%
A6-NM-0.35N-SL 50%
Figure 11.58: Effect of Class F Fly Ash at Different Cement Alkali Contents for the Highly Reactive A6-NM
Figure 11.59: Effect of Granulated Slag at Different Cement Alkali Contents for the Highly Reactive A6-NM
298
0.000.100.200.300.400.500.600.700.800.901.001.101.20
0 4 8 12 16 20 24 28 32Time, Days
Exp
ansi
on, %
A6-NM-1N-SF 0%
A6-NM-1N- SF 10%
A6-NM-0.75N-SF 5%
A6-NM-0.75N-SF 10%
A6-NM-0.5N-SF 5%
A6-NM-0.5N-SF 10%
A6-NM-0.35N-SF 5%
A6-NM-0.35N-SF 10%
0.000.100.200.300.400.500.600.700.800.901.001.101.20
0 4 8 12 16 20 24 28 32
Time, Days
Exp
ansi
on, %
A6-NM-1N-AE 0%
A6-NM-1N- AE 8%
A6-NM-0.75N-AE 4%
A6-NM-0.5N-AE 4%
A6-NM-0.35N-AE 4%
Figure 11.60: Effect of Silica Fume at Different Cement Alkali Contents for the Highly Reactive A6-NM
Figure 11.61: Effect of Air Entrainment at Different Cement Alkali Contents for the Highly Reactive A6-NM
299
0.000.100.200.300.400.500.600.700.800.901.001.101.20
0 4 8 12 16 20 24 28 32Time, Days
Exp
ansi
on, %
A6-NM-1N-CC 0%
A6-NM-1N- CC 17%
A6-NM-0.75N-CC 17%
A6-NM-0.5N-CC 17%
A6-NM-0.35N-CC 17%
Figure 11.62: Effect of Calcined at Different Cement Alkali Contents for
the Highly Reactive A6-NM
300
0.000.020.040.060.080.100.120.140.160.180.200.220.240.260.280.30
A6-NMInvestigated Aggregate
14-D
ay E
xpan
sion
, % A6-NM-1N-FAC 0%A6-NM-1N- FAC 35%A6-NM-0.75N-FAC 35%A6-NM-0.5N-FAC 35%A6-NM-0.35N-FAC 35%
Failure Criterion0.35N and 0.50N
Failure Criterion0.75N
0.000.020.040.060.080.100.120.140.160.180.200.220.240.260.280.30
A6-NMInvestigated Aggregate
14-D
ay E
xpan
sion
, % A6-NM-1N-FAC 0%A6-NM-0.75N-FAC 25%A6-NM-0.5N-FAC 25%A6-NM-0.35N-FAC 25%
Failure Criterion0.35N and 0.50N
Failure Criterion0.75N
Figure 11.63a: Comparison of the 14-Day Expansions for the Combination of 35% Class C Fly Ash with Different Cement Alkali Contents
Figure 11.63b: Comparison of the 14-Day Expansions for the Combination of 25% Class C Fly Ash with Different Cement Alkali Contents
Failure Criterion 0.75N Failure Criteria 0.35N and 0.50N
Failure Criterion 0.75 N Failure Criteria 0.35N and 0.50N
Failure Criterion 0.75 N Failure Criteria 0.35N and 0.50N
Failure Criterion 0.75 N Failure Criteria 0.35N and 0.50N
301
0.000.020.040.060.080.100.120.140.160.180.200.220.240.260.280.30
A6-NMInvestigated Aggregate
14-D
ay E
xpan
sion
, % A6-NM-1N-FAF 0%A6-NM-1N- FAF 25%A6-NM-0.75N-FAF 20%A6-NM-0.5N-FAF 20%A6-NM-0.35N-FAF 20%
Failure Criterion0.35N and 0.50N
Failure Criterion0.75N
0.000.020.040.060.080.100.120.140.160.180.200.220.240.260.280.30
A6-NMInvestigated Aggregate
14-D
ay E
xpan
sion
, % A6-NM-1N-FAF 0%A6-NM-0.75N-FAF 15%A6-NM-0.5N-FAF 15%A6-NM-0.35N-FAF 15%
Failure Criterion0.35N and 0.50N
Failure Criterion0.75N
Figure 11.64a: Comparison of the 14-Day Expansions for the Combination of 20% Class F Fly Ash with Different Cement Alkali Contents
Figure 11.64b: Comparison of the 14-Day Expansions for the Combination of 15% Class F Fly Ash with Different Cement Alkali Contents
Failure Criterion 0.75 N Failure Criteria 0.35N and 0.50N
Failure Criterion 0.75 N Failure Criteria 0.35N and 0.50N
302
0.000.020.040.060.080.100.120.140.160.180.200.220.240.260.280.30
A6-NMInvestigated Aggregate
14-D
ay E
xpan
sion
, % A6-NM-1N-SL 0%A6-NM-1N- SL 55%A6-NM-0.75N-SL 50%A6-NM-0.5N-SL 50%A6-NM-0.35N-SL 50%
Failure Criterion0.35N and 0.50N
Failure Criterion0.75N
0.000.020.040.060.080.100.120.140.160.180.200.220.240.260.280.30
A6-NMInvestigated Aggregate
14-D
ay E
xpan
sion
, %
A6-NM-1N-SL 0%A6-NM-0.75N-SL 25%A6-NM-0.5N-SL 25%A6-NM-0.35N-SL 25%
Failure Criterion0.35N and 0.50N
Failure Criterion0.75N
Figure 11.65a: Comparison of the 14-Day Expansions for the Combination of 50% Granulated Slag with Different Cement Alkali Contents
Figure 11.65b: Comparison of the 14-Day Expansions for the Combination of 25% Granulated Slag with Different Cement Alkali Contents
Failure Criterion 0.75 N Failure Criteria 0.35N and 0.50N
Failure Criterion 0.75 N Failure Criteria 0.35N and 0.50N
Failure Criterion 0.75 N Failure Criteria 0.35N and 0.50N
303
Label1 Label2
0.000.020.040.060.080.100.120.140.160.180.200.220.240.260.280.30
A6-NM
Investigated Aggregate
14-D
ay E
xpan
sion
, %
A6-NM-1N-SF 0%A6-NM-1N- SF 10%A6-NM-0.75N-SF 10%A6-NM-0.5N-SF 10%A6-NM-0.35N-SF 10%
0.000.020.040.060.080.100.120.140.160.180.200.220.240.260.280.30
A6-NMInvestigated Aggregate
14-D
ay E
xpan
sion
, %
A6-NM-1N-SF 0%A6-NM-0.75N-SF 5%A6-NM-0.5N-SF 5%A6-NM-0.35N-SF 5%
Failure Criterion0.35N and 0.50N
Failure Criterion0.75N
Figure 11.66a: Comparison of the 14-Day Expansions for the Combination of 10% Silica Fume with Different Cement Alkali Contents
Figure 11.66b: Comparison of the 14-Day Expansions for the Combination of 5% Silica Fume with Different Cement Alkali Contents
Failure Criteria 0.35N and 0.50N
Failure Criterion 0.75N
Failure Criterion 0.75 N Failure Criteria 0.35N and 0.50N
304
0.000.020.040.060.080.100.120.140.160.180.200.220.240.260.280.30
A6-NMInvestigated Aggregate
14-D
ay E
xpan
sion
, % A6-NM-1N-AE 0%A6-NM-1N- AE 8%A6-NM-0.75N-AE 4%A6-NM-0.5N-AE 4%A6-NM-0.35N-AE 4%
Failure Criterion0.35N and 0.50N
Failure Criterion0.75N
0.000.020.040.060.080.100.120.140.160.180.200.220.240.260.280.30
A6-NMInvestigated Aggregate
14-D
ay E
xpan
sion
, % A6-NM-1N-CC 0%A6-NM-1N- CC 17%A6-NM-0.75N-CC 17%A6-NM-0.5N-CC 17%A6-NM-0.35N-CC 17%
Failure Criterion0.35N and 0.50N
Failure Criterion0.75N
Figure 11.67: Comparison of the 14-Day Expansions for the Combination of Air Entrainment with Different Cement Alkali Contents
Figure 11.68: Comparison of the 14-Day Expansions for the Combination of Calcined Clay with Different Cement Alkali Contents
Failure Criterion 0.75 N Failure Criteria 0.35N and 0.50N
Failure Criterion 0.75 N Failure Criteria 0.35N and 0.50N
305
It was also suggested by Stark (1993) that lowering the normality of the solution
in which the mortar bars are stored for 14 days, has to be accompanied with a lower
14-day expansion limit as mentioned in Table 11.19.
Table 11.19: Exposure Solution Normalities Investigated and Their Corresponding Na2Oequiv. Content and Recommended Expansion Limits
Investigated Normality
1N (Standard)
0.75N 0.50N 0.35N
Corresponding Na2Oeqiv. Content
1.5% 1.15% 0.81% 0.6%
14-Day Expansion
Limit
0.10% 0.04% 0.04% 0.02%
11.11.1 Effect of Class C Fly Ash Coupled with Various Cement Alkali
Contents
Using Class C fly ash to replace 35% of the weight of cement was not effective in
reducing the mortar bar expansions of A6-NM (a highly reactive aggregate) below
the 14-day limit of 0.10% when the bars were tested using the standard 1N NaOH
solution (1.5% Na2Oequiv.). As the normality of the testing solution decreased, the
effectiveness of the Class C fly ash increased for both fly ash contents (Figures 11.57
and 11.63). At 0.75N (1.15% Na2Oequiv.), using 35% Class C fly ash was also not
effective in lowering the 14-day expansions below the limit. An alkali content
between 0.60% and 0.81% (0.35N and 0.50N) and the use of 35% Class C fly ash
were required to limit the 14-day expansions of A6-NM below 0.02%. Using 25%
Class C fly ash was not effective at any investigated alkali content. These
observations are summarized in Table 11.20. Thus, in order for Class C fly ash to be
able to mitigate the deleterious ASR expansions of the investigated highly reactive
aggregate, it should be used to replace 35% of the weight of a cement with an alkali
content of 0.80% or lower.
306
Table 11.20: Effectiveness of Class C Fly Ash at Different Cement Alkali Contents with the Highly Reactive Aggregate A6-NM (0.92% C1260, 14-Day)
Investigated Normality 1N (Standard) 0.75N 0.50N 0.35N
Corresponding Na2Oeqiv. Content 1.5% 1.15% 0.81% 0.6% Mitigation Alternative
Replacement Level Evaluation
25% Reactive Reactive Reactive Reactive Class C Fly Ash 35% Reactive Reactive Innocuous Innocuous
Reactive = Alternative exhibiting 14-day expansion higher than Table 11.19 limits Innocuous = Alternative exhibiting 14-day expansions lower than Table 11.19 limits
11.11.2 Effect of Class F Fly Ash Coupled with Various Cement Alkali Contents
When tested using the standard 1N NaOH solution, Class F fly ash was not
effective in decreasing the deleterious expansions of the highly reactive aggregate
A6-NM below safe levels even when it was used to replace 25% of the weight of
cement. As the normality of the testing solution was decreased, the corresponding
alkali content of the cement decreased, and the effectiveness of the Class F fly ash
increased for both fly ash contents investigated (Figures 11.58 and 11.64). Using
20% Class F fly ash at 0.75N was not effective in decreasing the 14-day expansions
below the proposed safe levels. It was as effective as using 25% Class F fly ash at
1N. It was noticed that when using the 0.5N and 0.35N solution normalities to
respectively represent the cases of 0.81 and 0.61% alkali content, 20% Class F fly
ash was required to decrease the 14-day expansions below 0.02%. Fifteen-percent
Class F fly ash was not effective even when tested in a 0.35N solution. Thus, in order
to mitigate the deleterious expansions of the highly reactive aggregate A6-NM, a
cement with an alkali content lower than 0.80% in combination with 20% Class F fly
ash was required. A summary of these observations is presented in Table 11.21.
307
Table 11.21: Effectiveness of Class F Fly Ash at Different Cement Alkali Contents with the Highly Reactive Aggregate A6-NM (0.92% C1260, 14-Day)
Investigated Normality 1N (Standard) 0.75N 0.50N 0.35N
Corresponding Na2Oeqiv. Content 1.5% 1.15% 0.81% 0.6% Mitigation Alternative
Replacement Level Evaluation
15% Reactive Reactive Reactive Reactive Class F Fly Ash 20% Reactive Reactive Innocuous Innocuous
Reactive = Alternative exhibiting 14-day expansion higher than Table 11.19 limits Innocuous = Alternative exhibiting 14-day expansions lower than Table 11.19 limits 11.11.3 Effect of Granulated Slag Coupled with Various Cement Alkali Content
Using granulated slag to replace 70% of the cement weight was effective in
mitigating the deleterious expansions of the highly reactive aggregate A6-NM when
the combination was evaluated using the 1N NaOH solution (1.5% Na2Oequiv.). In
order to determine whether lower percentages of granulated slag can be used with
lower cement alkali contents, the solution normality was decreased. Figures 11.59
and 11.65 illustrate that using 25% slag was not effective in mitigating the
deleterious alkali-silica reaction even when a solution normality of 0.35N was used
(0.6% Na2Oequiv.). When the A6-NM and slag combination was investigated using the
0.75N (1.15% Na2Oequiv.) solution normality, 50% slag was found to be not effective
in lowering the 14-day expansions below safe limits. However, 50% slag was
effective when evaluated using the 0.50N (0.80% Na2Oequiv.) and 0.35N (0.60%
Na2Oequiv.) in decreasing the 14-day expansions below 0.02%. Thus, 70% slag can be
used in combination with any alkali cement content (as high as 1.5% Na2Oequiv.). If a
lower alkali content cement is used, then the required slag percentage might be
decreased to 50% since the cement alkali content is lower than 0.8% Na2Oequiv..
Table 11.22 includes a summary of these observations.
308
Table 11.22: Effectiveness of Granulated Slag at Different Cement Alkali Contents with the Highly Reactive Aggregate A6-NM (0.92% C1260, 14-Day)
Investigated Normality 1N (Standard) 0.75N 0.50N 0.35N
Corresponding Na2Oeqiv. Content 1.5% 1.15% 0.81% 0.6% Mitigation Alternative
Replacement Level Evaluation
25% Reactive Reactive Reactive Reactive Granulated Slag 50% Reactive Reactive Innocuous Innocuous
Reactive = Alternative exhibiting 14-day expansion higher than Table 11.19 limits Innocuous = Alternative exhibiting 14-day expansions lower than Table 11.19 limits
11.11.4 Effect of Silica Fume Coupled with Various Cement Alkali Content
When evaluated using the 1N NaOH solution, the use of 10% silica fume was not
effective in decreasing the 14-day expansions of A6-NM below safe levels. This
level of replacement was effective when the solution normality was dropped to
0.50N and 0.35N at which levels the 14-day expansions of A6-NM were reduced to
lower than 0.02% (Figures 11.60 and 11.66). Using 5% silica fume was not effective
even when evaluated using the 0.35N NaOH solution. Thus, in order to mitigate the
ASR reaction of A6-NM, the use of 10% silica fume had to be coupled with the use
of a cement with an alkali content lower than 0.8%. Table 11.23 illustrates these
observations.
Table 11.23: Effectiveness of Silica Fume at Different Cement Alkali Contents with the Highly Reactive Aggregate A6-NM (0.92% C1260, 14-Day)
Investigated Normality 1N (Standard) 0.75N 0.50N 0.35N
Corresponding Na2Oeqiv. Content 1.5% 1.15% 0.81% 0.6% Mitigation Alternative
Replacement Level Evaluation
5% Reactive Reactive Reactive Reactive Silica Fume 10% Reactive Reactive Innocuous InnocuousReactive = Alternative exhibiting 14-day expansion higher than Table 11.19 limits Innocuous = Alternative exhibiting 14-day expansions lower than Table 11.19 limits
309
11.11.5 Effect of Air Entrainment Coupled with Various Cement Alkali Content
Using air entrainment to lower the 14-day expansions of A6-NM below safe
levels was not effective even when the mortar bars were investigated using the 0.35N
solution (Figures 10.61 and 10.67). Thus, even though air entrainment contributes in
decreasing the expansions of A6-NM, it cannot be used to mitigate the reaction even
when it was coupled with low alkali cement as seen in Table 11.24.
Table 11.24: Effectiveness of Air Entrainment at Different Cement Alkali Contents with the Highly Reactive Aggregate A6-NM (0.92% C1260, 14-Day)
Investigated Normality 1N (Standard) 0.75N 0.50N 0.35N
Corresponding Na2Oeqiv. Content 1.5% 1.15% 0.81% 0.6% Mitigation Alternative
Replacement Level Evaluation
5% Reactive Reactive Reactive ReactiveAir Entrainment 10% Reactive Reactive Reactive ReactiveReactive = Alternative exhibiting 14-day expansion higher than Table 11.19 limits Innocuous = Alternative exhibiting 14-day expansions lower than Table 11.19 limits
11.11.6 Effect of Calcined Clay Coupled with Various Cement Alkali Content When evaluated using the 1N NaOH solution, the use of 17% calcined clay was
not effective in decreasing the 14-day expansions of A6-NM below safe levels.
Twenty five percent calcined clay was required. The 17% level of replacement was
effective when the solution normality was dropped to 0.50N and 0.35N at which
levels the 14-day expansions of A6-NM were reduced to lower than 0.02% (Figures
11.62 and 11.68). Thus, in order to mitigate the ASR reaction of A6-NM, the use of
17% calcined clay had to be coupled with the use of a cement with an alkali content
lower than 0.8%. Table 11.24 illustrates these observations.
310
Table 11.25: Effectiveness of Calcined Clay at Different Cement Alkali Contents with the Highly Reactive Aggregate A6-NM (0.92% C1260, 14-Day)
Investigated Normality 1N (Standard) 0.75N 0.50N 0.35N
Corresponding Na2Oeqiv. Content 1.5% 1.15% 0.81% 0.6%
Mitigation Alternative
Replacement Level Evaluation
25% Innocuous Innocuous Innocuous InnocuousAir Entrainment 17% Reactive Reactive Innocuous Innocuous
Reactive = Alternative exhibiting 14-day expansion higher than Table 11.19 limits Innocuous = Alternative exhibiting 14-day expansions lower than Table 11.19 limits
11.12 EVALUATION OF THE MITIGATION ALTERNATIVES C 1260 RESULTS USING KOLMOGOROV-AVRAMI-MEHL-JOHNSTON’S MODEL
The Kolmogorov-Avrami-Mehl-Johnson’s (K-A-M-J) model, described earlier in
section 4.18.5, was used to evaluate the results of the test of different alternatives for
mitigating the excessive expansions caused by ASR. The 3-, 7-, 11-, and 14-day C
1260 results were used to determine the variables required by the model and they are
ln (K) and M. Results are presented in Figures 11.69 through 11.80. A second set of
variables was developed using the 3-, 7-, 11-, 14-, 21-, and 28-day C 1260 results.
Results for the 28-day set are presented in Appendix B.
311
-10.0-9.0-8.0-7.0-6.0-5.0-4.0-3.0-2.0-1.00.0
A6-NM A4-ID A2-WY C2-SD B4-VA
Ln
(K)
20% Class C27.5% Class C35% Class C15% Class F25% Class F
Figure 11.69: Ln (K) Values for Various Class C and Class F Fly Ash Replacement Levels Using 14-Day C 1260 Results
Failure Limit
312
-12.0
-10.0
-8.0
-6.0
-4.0
-2.0
0.0A6-NM A4-ID A2-WY C2-SD B4-VA
Ln
(K)
5% Silica Fume10% Silica Fume40% Slag55% Slag70% Slag
-10.0-9.0-8.0-7.0-6.0-5.0-4.0-3.0-2.0-1.00.0
A6-NM A4-ID A2-WY C2-SD B4-VA
Ln
(K)
17% Calcined Clay
25% Calcined Clay
21g Lithium Nitrate
28g lithium Nitrate
60g Lithium Nitrate
Figure 11.70: Ln (K) Values for Various Silica Fume and Granulated Slag Replacement Levels Using 14-Day C 1260 Results
Figure 11.71: Ln (K) Values for Various Calcined Clay and LiNO3 Replacement Levels Using 14-Day C 1260 Results
Failure Limit
Failure Limit
313
-10.0-9.0-8.0-7.0-6.0-5.0-4.0-3.0-2.0-1.00.0
A6-NM A4-ID A2-WY C2-SD B4-VA
Ln
(K)
4% Entrained Air8% Entrained AirW/C = 0.35W/C = 0.55W/C = 0.65
0.0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
A6-NM A4-ID A2-WY C2-SD B4-VA
Con
stan
t M
20% Class C27.5% Class C35% Class C15% Class F25% Class F
Figure 11.72: Ln (K) Values for Various Air Entrainment Levels and Various Water-Cement Ratios Using 14-Day C 1260 Results
Figure 11.73: M Values for Various Class C and Class F Fly Ash Replacement Levels Using 14-Day C 1260 Results
Failure Limit
Failure Limit
314
0.0
0.5
1.0
1.5
2.0
2.5
3.0
A6-NM A4-ID A2-WY C2-SD B4-VA
Con
stan
t M
5% Silica Fume10% Silica Fume40% Slag55% Slag70% Slag
0.0
0.5
1.0
1.5
2.0
2.5
3.0
A6-NM A4-ID A2-WY C2-SD B4-VA
Con
stan
t M
17% Calcined Clay
25% Calcined Clay
21g Lithium Nitrate
28g lithium Nitrate
60g Lithium Nitrate
Figure 11.74: M Values for Various Silica Fume and Granulated Slag Replacement Levels Using 14-Day C 1260 Results
Figure 11.75: M Values for Various Calcined Clay and LiNO3 Replacement Levels Using 14-Day C 1260 Results
Failure Limit
Failure Limit
315
0.0
0.5
1.0
1.5
2.0
2.5
3.0
A6-NM A4-ID A2-WY C2-SD B4-VA
Con
stan
t M
4% Entrained Air8% Entrained AirW/C = 0.35W/C = 0.55W/C = 0.65
0.0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
-10.0 -8.0 -6.0 -4.0 -2.0 0.0Ln (K)
Con
stan
t M 20% Class C27.5% Class C35% Class C15% Class F25% Class F
Figure 11.76: M Values for Various Air Entrainment Levels and Various Water-Cement Ratios Using 14-Day C 1260 Results
Figure 11.77: Ln (K) vs. M Plot for the Class C and Class F Fly Ash C 1260 Results
Failure Limit
Failure Limit
316
0.0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
-10.0 -8.0 -6.0 -4.0 -2.0 0.0Ln (K)
Con
stan
t M
5% Silica Fume10% Silica Fume40% Slag55% Slag70% Slag
0.0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
-10.0 -8.0 -6.0 -4.0 -2.0 0.0Ln (K)
Con
stan
t M
17% Calcined Clay25% Calcined Clay21g Lithium Nitrate28g lithium Nitrate60g Lithium Nitrate
Figure 11.78: Ln (K) vs. M Plot for the Silica Fume and Granulated Slag C 1260 Results
Figure 11.79: Ln (K) vs. M Plot for the Calcined Clay and LiNO3 C 1260 Results
Failure Limit
Failure Limit
317
0.0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
-10.0 -8.0 -6.0 -4.0 -2.0 0.0Ln (K)
Con
stan
t M
4% Entrained Air8% Entrained AirW/C = 0.35W/C = 0.55W/C = 0.65
For a mitigation alternative to be effective, it should have ln (k) values that are
more negative than –6. Using this criterion, the effectiveness of the investigated
mitigation alternatives is evaluated in Table 11.26.
It can be inferred from Table 11.26 that the only alternatives that were
effective with all six aggregates are the use of 70% granulated slag and 25% calcined
clay. Alternatives that were effective with slowly reactive aggregates (B4-VA and
C2-SD) are the use of 25% Class F fly ash, 70% slag, 17 and 25% calcined clay, and
60g of LiNO3. Alternatives that were effective with the moderately reactive
aggregate A2-WY are the use of 70% slag and 25% calcined clay. Alternatives that
were effective with the highly reactive aggregates A4-ID and A6-NM are the use of
70% slag and 25% calcined clay. It seems that different levels of aggregate reactivity
require different mitigation alternatives.
The use of both criteria, 14-day expansion of 0.10% and Ln (k) = -6, resulted in
the conclusion that the only mitigation alternatives that are effective with all
Figure 11.80: Ln (K) vs. M Plot for the Air Entrainment and Various W/C C 1260 Results
Failure Limit
318
aggregates are the use of 70% slag and 25% calcined clay. The evaluation differed
slightly when it came to the individual aggregates.
Table 11.26: Mitigation Alternatives Results Using K-A-M-J’s Ln (k) = -6 Note: Not Effective = ln(k) > -6 and Effective = ln(k) < -6
Mitigation Alternative
ReplacementLevel A6-NM A4-ID A2-WY B4-VA C2-SD
20% Not Effective
Not Effective
Not Effective
Not Effective
Not Effective
27.5% Not Effective
Not Effective
Not Effective
Not Effective
Not Effective
Class C Fly Ash
35% Not Effective
Not Effective
Not Effective
Not Effective
Not Effective
15% Not Effective
Not Effective
Not Effective
Not Effective Effective Class F Fly
Ash 25% Not Effective
Not Effective
Not Effective Effective Effective
5% Not Effective
Not Effective
Not Effective
Not Effective
Not Effective Silica Fume
10% Not Effective Effective Not
Effective Not
Effective Effective
40% Not Effective
Not Effective
Not Effective
Not Effective Effective
55% Not Effective Effective Not
Effective Not
Effective Effective Granulated
Slag
70% Effective Effective Effective Effective Effective
17% Not Effective
Not Effective
Not Effective Effective Effective Calcined Clay
25% Effective Effective Effective Effective Effective
21 g Not Effective
Not Effective
Not Effective
Not Effective Effective
28 g Not Effective
Not Effective
Not Effective
Not Effective Effective Lithium
Nitrate
60 g Not Effective Effective Not
Effective Effective Effective
4% Not Effective
Not Effective
Not Effective
Not Effective
Not Effective Entrained Air
8% Not Effective
Not Effective
Not Effective
Not Effective
Not Effective
319
11.13 PREDICTIONS OF EFFECTIVE LEVELS OF REPLACEMENT USING K-M-A-J’S MODEL
Since the investigated levels of cement replacement with Class C fly ash, Class F
fly ash and silica fume were found not effective in mitigating ASR when evaluated
using the K-M-A-J’s model, the model was used to predict effective levels of
replacement. Results are presented in Table 11.27 and Appendix C. The
effectiveness of some of the predictions is demonstrated in Figure 11.81 through
11.86. Results of the C 1260 investigation of some of the predicted levels are
presented in Table 11.28.
Table 11.27: Predicted Levels of Replacement Using the K-M-A-J’s Model A6-NM
H.R. A4-ID H.R.
A2-WY M.R.
C2-SD S.R.
B4-VA S.R.
Class C Fly Ash 50% 65% 80% 45% 50%
Class F Fly Ash 40% 30% 30% 15% 20%
Silica Fume 20% 15% 15% 8% 20%
H.R. = Highly Reactive M.R. = Moderately Reactive S.R. = Slowly Reactive Highlighted Box = Values that were Investigated Not Highlighted Box = Values that were effective before
320
Table 11.28: C 1260 Expansions of Some Predicted Values of the K-M-A-J’s Model
Expansion, % 4-Day 7-Day 11-Day 14-Day 21-Day 28-DayAggregate
ID Mitigation Alternative
Replacement Level A2-WY
A2-WY Class C Fly Ash 80% 0.01 0.01 0.01 0.01 0.01 0.01
A2-WY Class F Fly Ash 30% 0.00 0.00 0.00 0.02 0.03 0.04
A2-WY Silica Fume 15% 0.01 0.03 0.04 0.07 0.11 0.14
A4-ID
A4-ID Class C Fly Ash 65% 0.00 0.01 0.01 0.02 0.02 0.03
A4-ID Class F Fly Ash 30% 0.00 0.01 0.02 0.03 0.06 0.11
A4-ID Silica Fume 10% 0.02 0.03 0.05 0.08 0.14 0.19
A6-NM
A6-NM Class C Fly Ash 50% 0.00 0.01 0.01 0.02 0.03 0.03
A6-NM Class F Fly Ash 40% 0.00 0.01 0.01 0.02 0.04 0.06
A6-NM Silica Fume 20% 0.02 0.03 0.05 0.09 0.16 0.22
B4-VA
B4-VA Class C Fly Ash 50% 0.01 0.02 0.04 0.04 0.06 0.10
B4-VA Silica Fume 20% 0.02 0.03 0.05 0.05 0.08 0.12
C2-SD
C2-SD Class C Fly Ash 45% 0.00 0.01 0.01 0.02 0.03 0.04
321
-0.050.000.050.100.150.200.250.300.350.40
0 4 8 12 16 20 24 28 32
Time, Days
Exp
ansi
on, %
A2-WY 0%A2-WY-FAC 80%A2-WY-FAF 30%A2-WY-SF 15%
0.000.100.200.300.400.500.600.700.800.901.001.10
0 4 8 12 16 20 24 28 32
Time, Days
Exp
ansi
on, %
A4-ID 0%A4-ID-FAC 65%A4-ID-FAF 30%A4-ID-SF 10%
Figure 11.81: Effectiveness of the K-M-A-J Model Predictions for Aggregate A2-WY
Figure 11.82: Effectiveness of the K-M-A-J Model Predictions for Aggregate A4-ID
322
0.000.100.200.300.400.500.600.700.800.901.001.101.20
0 4 8 12 16 20 24 28 32
Time, Days
Exp
ansi
on, %
A6-NM 0%A6-NM-FAC 50%A6-NM-FAF 40%A6-NM-SF 20%
0.00
0.05
0.10
0.15
0.20
0.25
0.30
0 4 8 12 16 20 24 28 32
Time, Days
Exp
ansi
on, %
B4-VA 0%B4-VA-FAC 50%B4-VA-SF 20%
Figure 11.83: Effectiveness of the K-M-A-J Model Predictions for Aggregate A6-NM
Figure 11.84: Effectiveness of the K-M-A-J Model Predictions for Aggregate B4-VA
323
0.00
0.05
0.10
0.15
0.20
0.25
0.30
0.35
0 4 8 12 16 20 24 28 32
Time, Days
Exp
ansi
on, % C2-SD 0%
C2-SD-FAC 45%
0.000.100.20
0.300.400.500.600.70
0.800.901.00
A6-NM A4-ID A2-WY C2-SD B4-VA
Investigated Aggregate
14-D
ay E
xpan
sion
, %
40%
Cla
ss F
Fly
Ash
30%
Cla
ss F
Fly
Ash
30%
Cla
ss F
Fly
Ash
20%
Sili
ca F
ume
65%
Cla
ss C
Fly
Ash
15%
Sili
ca F
ume
80%
Cla
ss C
Fly
Ash
20%
Sili
ca F
ume
45%
Cla
ss C
Fly
Ash
50%
Cla
ss C
Fly
Ash
15%
Sili
ca F
ume
50%
Cla
ss C
Fly
Ash
Figure 11.85: Effectiveness of the K-M-A-J Model Predictions for Aggregate C2-SD
Figure 11.86: Comparison Between the 14-Day C 1260 expansions of Aggregates with 0% Replacement and with Predicted Replacements
Control
324
Results presented above indicate that replacing the cement with Class C fly ash,
Class F fly ash, or silica fume at levels predicted by the K-A-M-J’s model is
effective in mitigating the deleterious ASR expansions. The investigated alternatives
and aggregate combinations (Table 10.12) showed 14-day expansions below 0.10%.
It can be concluded that the model is effective in representing the actual expansions
that the bars are undergoing. The following conclusions about the effectiveness of
mitigation alternatives can be drawn:
1. Between 65% and 80% Class C fly as was needed to mitigate ASR in moderately
(M.R.) and highly (H.R.) reactive aggregates.
2. About 45% to 50% Class C fly ash was needed to mitigate ASR in slowly
reactive (S.R.) aggregates.
3. Between 30% and 40% Class F fly ash was needed to mitigate ASR in M.R. and
H.R. aggregates.
4. Between 15% and 20% silica fume was needed to mitigate ASR in H.R., M.R.,
and S.R. aggregates.
It can be noticed that these levels are on the high side and higher than what is usually
used in the field.
1. Practically, the highest percentage of Class C fly ash used in the field is 35% of
the weight of cement. In order for Class C fly ash to be effective in mitigating
ASR, replacement levels from 45% to 80% by weight were required. These high
contents of Class C fly ash might be achieved if the ash was used to add fines to
the concrete mixture. It should be noted that A6-NM, which is the most reactive
aggregate investigated, required a 50% Class C fly ash content in order to
decrease the 14-day expansion below 0.10%, specifically 0.02%. As a result,
using 50% Class C fly ash could be used with the other less reactive aggregates.
2. Class F fly ash is usually used to replace 15% to 25% of the weight of cement.
The predicted range of 30% to 40% is on the high side and may not be very
325
practical for many concretes. These high levels might be achieved if adding the
ash as fine materials is an option.
3. Silica fume is usually used to replace 5% to 10% of the weight of cement. Using
between 15% and 20% silica fume will result in a high-fines content concrete and
might not be practical.
11.14 ASTM C 1260 INVESTIGATION OF MITIGATION ALTERNATIVES: SUMMARY
The following Tables list the effective mitigation alternatives for each aggregate.
These results were generated using the ASTM C 1260 procedures.
326
Table 11.29: Effective ASR Mitigation Alternatives When Evaluating Aggregates Using ASTM C 1260 with 1N NaOH Solution (1.5% Na2Oequiv.)
Aggregate, 14-day expansion, C 1260 Classification A6-NM 0.91% (H.R.)
A4-ID 0.79% (H.R.)
A2-WY 0.29% (H.R.)
C2-SD 0.17% (S.R.)
B4-VA 0.15% (S.R.)
E2-IA 0.42% (H.R.) Cementitious
Material Minimum Replacement Levels by Weight of Cement Calcined
Clay 25% 25% 25% 17% 17% 25%
Granulated Slag 70% 55% 55% 40% 55% 55%
Class F Fly Ash 40% 25% 25% 15% 25% 25%
Silica Fume 10% 10%
Air Entrainment 4%
Class C Fly Ash 50% 50% 50% 35% 35% 50%
Chemical Admixture Minimum LiNO3 Volume (weight) per 1 kg of Na2Oequiv.
Lithium Nitrate 4.6 L
(5.5 kg) 4.6 L
(5.5 kg) 4.6 L
(5.5 kg) 4.6 L
(5.5 kg) Shaded Areas = Alternative could not be used
327
Table 11.30: Effective ASR Mitigation Alternatives for Highly Reactive Aggregate A6-NM (C1260 14-day of 0.92%) Evaluated Using C 1260 with
0.75N, 0.50N, & 0.35N NaOH Solutions Minimum Replacement Levels by Weight of Cement
Highly Reactive Aggregate A6-NM Cementitious
Material 1N NaOH
(1.5%Na2Oequiv.) 0.75N NaOH
(1.15%Na2Oequiv.)0.50N NaOH
(0.81%Na2Oequiv.) 0.35N NaOH
(0.60%Na2Oequiv.)Calcined
Clay 25% 25% 17% 17%
Granulated Slag 70% 55% 50% 50%
Class F Fly Ash 40% 25% 20% 20%
Silica Fume 10% 10%
Class C Fly Ash 50% 50% 35% 35%
Minimum LiNO3 Volume (weight) per 1 kg of Na2Oequiv. Highly Reactive Aggregate A6-NM
Chemical Admixture
1N NaOH (1.5%Na2Oequiv.)
0.75N NaOH (1.15%Na2Oequiv.)
0.50N NaOH (0.81%Na2Oequiv.)
0.35N NaOH (0.60%Na2Oequiv.)
Lithium Nitrate 3.5 L (4.18 kg) 3.5 L (4.18 kg)
Air Entrainment
Shaded Areas = Alternative could not be used
11.15 COMPARISON OF THE MITIGATION ALTERNATIVES
Figures 11.87 through 11.92 provide a comparison between the effectiveness of
each of the investigated ASR mitigation alternatives for all six aggregates tested. As
can be seen in these figures, the effectiveness of the mitigation depended on the
aggregates. It seems that using 70% slag resulted in the lowest 14-day expansions for
all aggregates, followed by 25% calcined clay.
328
Highly Reactive Aggregate A6-NM
0 0.2 0.4 0.6 0.8 1
No Mitigation5% Silica Fume
21g LiNO328g LiNO3
20% Class C Fly Ash15% Class F Fly Ash
40% Slag27.5% Class C Fly
60g LiNO335% Class C Fly Ash
10% Silica Fume17% Calcined Clay
55% Slag25% Class F Fly Ash
25% Calcined Clay70%Slag
Miti
gatio
n A
ltern
ativ
e
14-Day Expansion, %
Highly Reactive Aggregate A4-ID
0 0.2 0.4 0.6 0.8 1
No Mitigation5% Silica Fume
21g LiNO328g LiNO3
20% Class C Fly Ash40% Slag
15% Class F Fly Ash27.5% Class C Fly
60g LiNO335% Class C Fly Ash
17% Calcined Clay10% Silica Fume
25% Class F Fly Ash55% Slag
25% Calcined Clay70%Slag
Miti
gatio
n A
ltern
ativ
e
14-Day Expansion, %
Figure 11.87: Mitigation Alternatives Used with Aggregate A6-NM
Best
Worst
Figure 11.88: Mitigation Alternatives Used with Aggregate A4-ID
Best
Worst
329
Highly Reactive Aggregate A2-WY
0 0.05 0.1 0.15 0.2 0.25 0.3 0.35 0.4
No Mitigation5% Silica Fume
20% Class C Fly Ash40% Slag
15% Class F Fly Ash27.5% Class C Fly
10% Silica Fume35% Class C Fly Ash
17% Calcined Clay21g LiNO3
55% Slag28g LiNO3
25% Class F Fly Ash25% Calcined Clay
60g LiNO370%Slag
Miti
gatio
n A
ltern
ativ
e
14-Day Expansion, %
Highly Reactive Aggregate C2-SD
0 0.05 0.1 0.15 0.2
No Mitigation20% Class C Fly Ash
5% Silica Fume21g LiNO3
40% Slag15% Class F Fly Ash
27.5% Class C Fly Ash28g LiNO3
10% Silica Fume35% Class C Fly Ash
55% Slag17% Calcined Clay
25% Class F Fly Ash60g LiNO3
25% Calcined Clay70%Slag
Miti
gatio
n A
ltern
ativ
e
14-Day Expansion, %
Figure 11.89: Mitigation Alternatives Used with Aggregate A2-WY
Best
Worst
Figure 11.90: Mitigation Alternatives Used with Aggregate C2-SD
Best
Worst
330
Highly Reactive Aggregate B4-VA
0 0.02 0.04 0.06 0.08 0.1 0.12 0.14 0.16
No Mitigation20% Class C Fly Ash
5% Silica Fume21g LiNO3
27.5% Class C Fly Ash15% Class F Fly Ash
28g LiNO335% Class C Fly Ash
10% Silica Fume40% Slag
25% Class F Fly Ash60g LiNO3
17% Calcined Clay55% Slag
25% Calcined Clay70%Slag
Miti
gatio
n A
ltern
ativ
e
14-Day Expansion, %
Highly Reactive Aggregate E2-IA
0 0.05 0.1 0.15 0.2 0.25 0.3 0.35 0.4 0.45
No Mitigation20% Class C Fly Ash
5% Silica Fume15% Class F Fly Ash
27.5% Class C Fly Ash40% Slag
10% Silica Fume35% Class C Fly Ash
17% Calcined Clay55% Slag
21g LiNO328g LiNO3
25% Class F Fly Ash60g LiNO3
70%Slag25% Calcined Clay
Miti
gatio
n A
ltern
ativ
e
14-Day Expansion, %
Figure 11.91: Mitigation Alternatives Used with Aggregate B4-VA
Best
Worst
Figure 11.92: Mitigation Alternatives Used with Aggregate E2-IA
Best
Worst
331
CHAPTER TWELVE
INVESTIGATION OF MITIGATION ALTERNATIVES USING ASTM C 1293 AND ACCELERATED ASTM C 1293
12.1 INTRODUCTION
ASTM C 1293 and accelerated C 1293 were used to evaluate the effects of Class
C fly ash, Class F fly ash, silica fume, granulated slag, calcined clay, lithium nitrate
(LiNO3), air content, and cement alkali content on the ASR reactivity of selected
aggregates. A summary of the investigation is presented in Figure 12.1.
ASTM C 1293 is a concrete prism test that consists of storing three 3-in. x 3-in. x
11-in. concrete prisms over water, at 100% relative humidity, in a sealed container
with wicks on the sides, and at 380C. A cement content of 708 ± 17 lb/yd3 is required
and the alkali content of the cement is increased to 1.25% Na2Oequiv. by adding
NaOH to the mixing water. The accelerated C 1293 test consists of performing the
same procedures; however, the prisms are stored in containers at 600C. Results of the
investigation of these modified procedures were presented and discussed in Chapter
10 where it was shown that these procedures produced results within a period of 3
months that are similar to the C 1293 results after 12 months. Figure 10.16 shows the
high correlation between the results of both tests (R2 = 0.98).
A list of aggregates used for investigating mitigation alternatives using both C
1260 and C 1293 is included in Table 12.1. For investigating mitigation alternatives
using C 1293 one aggregate from each reactivity category was chosen. Three
aggregates were chosen for these investigations: A4-ID (highly reactive C 1260 and
C 1293), A2-WY (moderately reactive C 1260 and C 1293), and C2-SD (slowly
reactive C 1260 and C 1293). E2-IA was found to be innocuous when tested in
accordance to C 1293 and as a result was not included in the C 1293 investigation
but was used with the accelerated C 1293.
332
Class C Fly Ash 20%, 27.5%, 35%
Control
Class F Fly Ash 15%, 25%
Silica Fume 5%, 10%
Granulated Slag 25%, 55%, 70%
Calcined Clay 17%, 25%
Lithium Nitrate 3.5L, 4.6L, 10L
Air Entrainment 2-4%, 6-8%
Low-Alkali Cement Content
0.6%, 0.90%, 1.25%
ASTM C 1293 - Concrete prisms - Alkali content 1.25% - Cement: 708 ± 17 lb/yd3
- W/C = 0.45 - Store prisms over water- Container with Wicks - 100% R.H. - Container stored at 380C
Accelerated ASTM C 1293
- Concrete prisms - Alkali content 1.25% - Cement: 708 ± 17 lb/yd3
- W/C = 0.45 - Store prisms over water- Container with Wicks - 100% R.H. - Container stored at 600C
ASTM C 1293 2-year (104-weeks)
Expansion of 0.040%
Accelerated ASTM C 1293
6-month (26-weeks) Expansion of
0.040%
ASTM C 1293 one-year (52-
weeks) Expansion of 0.040%
Accelerated ASTM C 1293
3-month (13-weeks) Expansion of
0.040%
Failure Criteria Concrete Samples Testing Method
Figure 12.1: Summary of the Investigation of Mitigation Alternatives Using C 1293 and Accelerated C 1293
333
Table 12.1: Aggregates Used for Mitigation Alternative Investigation Original (Non-Mitigation Study) Results Mitigation Study
Aggregate ID
14-Day C 1260
Expansion
One-Year C 1293
Expansion
3-month Accelerated 600C C 1293 Expansion
Aggregate Used for C 1260
Investigation
Aggregate Used for C 1293
Investigation
Aggregate Used for Modified C 1293
Investigation
A6-NM 0.91% (H.R.)
0.308% (H.R.)
0.427% (H.R.)
A4-ID 0.79% (H.R.)
0.305% (H.R.)
0.467% (H.R.)
A2-WY 0.29% (H.R.)
0.107% (H.R.)
0.072% (H.R.)
C2-SD 0.17% (S.R.)
0.043% (S.R.)
0.059% (S.R.)
B4-VA 0.15% (S.R.)
0.040% (S.R.)
0.043% (S.R.)
E2-IA 0.42% (H.R.)
0.025% (Innocuous)
0.024% (Innocuous)
= Aggregate Used Using These procedures H.R. = Highly Reactive = C 1260 14-day expansion > 0.20% = C 1293 1-year, Modified C 1293 3-month expansion > 0.070% S.R. = Slowly Reactive = 0.10% < C 1260 14-day expansion < 0.20% = 0.040% < C 1293 One-Year expansion < 0.070% = 0.040% < Modified C 1293 3-month expansion <0.070%
Innocuous = C 1260 14-day expansion < 0.10%
Based on C 1293, an alternative is considered effective if it decreases the 52-week
(one-year) expansions of concrete prisms below 0.040%. For evaluating pozzolanic
materials such as Class C fly ash, Class F fly ash, silica fume, slag, and calcined clay,
expansions should be monitored for a period of 104 weeks (two years) after which
expansions higher than 0.040% are considered reactive. This two-years limit was
proposed in the literature by researchers who found that the effect of pozzolanic
materials could not be assessed using the one-year limit. Expansions should be
monitored over a longer period of time and two years was found to be adequate
(Fournier 1992, Shayan 1992, and etc.). At this stage only the one-year expansions
are available. The remainder of the data will be available in a later report. Thus,
mitigation alternatives resulting in C 1293 expansions that exceed 0.040% after one-
year of testing are considered to be not effective in mitigating ASR.
334
Based on the accelerated C 1293 procedures (procedures of C 1293 performed at
600C instead of 380C), an alternative is considered effective if it decreases the 13-
week (3-month) expansions below 0.040%. For evaluating pozzolanic materials such
as Class C fly ash, Class F fly ash, silica fume, slag, and calcined clay, expansions
should be monitored for a period of 26 weeks (6 months) after which expansions
higher than 0.040% are considered reactive.
12.2 INVESTIGATION OF MITIGATION ALTERNATIVES USING C 1293
12.2.1 Effect of Class C Fly Ash Using C 1293
In order to investigate the effect of Class C fly ash on the expansions due to ASR,
three levels of cement replacement were investigated namely, 20, 27.5, and 35%. The
three aggregates identified in Table 12.1 were used to prepare the different mixtures
listed in Table 7.15. Results for these procedures are illustrated in Table 12.2 and
Figures 12.2 through 12.4. A comparison of the one-year expansions of the various
replacement levels is shown in Figure 12.5. As mentioned in Figure 12.1, a failure
limit of 0.040% at two years is used to evaluate the use of Class C fly ash.
From these results it can be noticed that expansions decreased with increasing
Class C fly ash contents. Replacing up to 35% of the weight of cement with Class C
fly ash decreased the one-year expansions of the highly reactive aggregates A4-ID to
0.034%, of the highly reactive aggregate A2-WY to 0.031%, and of the slowly
reactive aggregate to 0.016%, all of which are lower than 0.040%. But as mentioned
earlier, the effectiveness of Class C fly ash should be determined using the two-years
expansions, and, thus, it is not possible at this stage to determine the effect of 35%
Class C fly ash on ASR. However, it should be noted that the one-year expansions of
A4-ID and A2-WY when used with 35% Class C fly ash are very close to the limit of
0.040%. It is expected that these expansions will be higher than 0.040% after two-
years of testing.
335
Table 12.2: C 1293 Expansions Using Class C Fly Ash Class C Fly Ash Replacement Level by Weight of Cement
0% 20% 27.5% 35% Time Aggregate A4-ID Expansions, %
1-week 0.019 -0.001 0.004 0.001 2-week 0.026 0.009 0.007 0.005 4-week 0.039 0.014 0.015 0.006 6-week 0.092 0.017 0.017 0.012 8-week 0.141 0.022 0.020 0.014
13-week 0.216 0.028 0.027 0.018 18-week 0.267 0.038 0.037 0.024 26-week 0.319 0.057 0.042 0.033 39-week 0.350 0.081 0.040 0.029 52-week 0.379 0.094 0.042 0.034
Aggregate A2-WY Expansions, % 1-week 0.003 0.011 0.004 0.001 2-week 0.005 0.013 0.024 0.005 4-week 0.009 0.023 0.026 0.011 6-week 0.010 0.023 0.029 0.011 8-week 0.013 0.027 0.034 0.014
13-week 0.018 0.032 0.037 0.017 18-week 0.028 0.045 0.047 0.026 26-week 0.067 0.050 0.051 0.030 39-week 0.109 0.049 0.049 0.027 52-week 0.107 0.058 0.057 0.031
Aggregate C2-SD Expansions, % 1-week 0.010 0.002 0.001 0.000 2-week 0.006 0.008 0.008 0.003 4-week 0.015 0.008 0.009 0.003 6-week 0.017 0.010 0.012 0.005 8-week 0.019 0.016 0.016 0.009
13-week 0.025 0.023 0.022 0.014 18-week 0.030 0.028 0.023 0.017 26-week 0.043 0.036 0.027 0.017 39-week 0.051 0.033 0.025 0.014 52-week 0.053 0.034 0.028 0.016
336
-0.040
0.000
0.040
0.080
0.120
0 4 8 12 16 20 24 28 32 36 40 44 48 52 56
Time, Weeks
52-W
eek
(One
-Yea
r) E
xpan
sion
, %
ID-FAC 0%ID-FAC 20%ID-FAC 27.5%ID-FAC 35%
0.000
0.010
0.020
0.030
0.040
0.050
0.060
0.070
0 4 8 12 16 20 24 28 32 36 40 44 48 52 56
Time, Weeks
52-W
eek
(One
-Yea
r) E
xpan
sion
, %
WY-FAC 0%WY-FAC 20%WY-FAC 27.5%WY-FAC 35%
Figure 12.2: Effect of Class C Fly Ash on C 1293 Expansions of Aggregate A4-ID
Figure 12.3: Effect of Class C Fly Ash on C 1293 Expansions of Aggregate A2-WY
337
-0.005
0.000
0.005
0.010
0.015
0.020
0.025
0.030
0.035
0.040
0 4 8 12 16 20 24 28 32 36 40 44 48 52 56
Time, Weeks
52-W
eek
(One
-Yea
r) E
xpan
sion
, %
SD-FAC 0%SD-FAC 20%SD-FAC 27.5%SD-FAC 35%
0.000
0.040
0.080
0.120
A4-ID A2-WY C2-SDAggregate Investigated
52-W
eek
(One
-Yea
r) E
xpan
sion
, % 0% Class C Fly Ash20% Class C Fly Ash27.5% Class C Fly Ash35% Class C Fly Ash
Figure 12.4: Effect of Class C Fly Ash on C 1293 Expansions of Aggregate C2-SD
Figure 12.5: Comparison Between the 52-week (one-year) Expansions of the Different Aggregates and Levels of Class C Fly Ash Replacement
338
Using 20% and 27.5% Class C fly ash with the highly reactive aggregates A4-ID
and A2-WY produced one-year expansions that are higher than 0.040% and were
concluded not effective in mitigating ASR for these aggregates. A summary of these
findings is included in Table 12.3.
Table 12.3: Effect of Class C Fly Ash on ASR Using C 1293 Class C Fly Ash
Replacement by Weight of Cement Aggregate
ID
C 1293 One-Year Expansion
C 1293 Classification 20% 27.5% 35%
A4-ID 0.379% H.R. H.R. S.R. Inconclusive A2-WY 0.107% H.R. S.R. S.R. Inconclusive C2-SD 0.053% S.R. Inconclusive Inconclusive Inconclusive H.R. = Highly Reactive = C 1293 One-Year expansion > 0.070% S.R. = Slowly Reactive = 0.040% < C 1293 One-Year expansion < 0.070%
Innocuous = C 1293 One-Year expansion < 0.040% Inconclusive = C 1293 two-year expansion not available
12.2.2 Effect of Class F Fly Ash Using C 1293
In order to investigate the effect of Class F fly ash on the expansions due to ASR,
two levels of cement replacement were investigated, namely 15 and 25%. The three
aggregates identified in Table 12.1 were used to prepare the various mixtures listed
in Table 7.16. Expansion results for these procedures are illustrated in Table 12.3a
and Figures 12.6 through 12.8. A comparison of the one-year expansions of the
various replacement levels is shown in Figure 12.9. As shown in Figure 12.1, a
failure limit of 0.040% at two years was used to evaluate the use of Class F fly ash.
339
0.0000.0400.0800.1200.1600.2000.2400.2800.3200.3600.400
0 4 8 12 16 20 24 28 32 36 40 44 48 52 56
Time, Weeks
52-W
eek
(One
-Yea
r) E
xpan
sion
, %
ID-FAF 0%ID-FAF 15%ID-FAF 25%
-0.020
0.000
0.020
0.040
0.060
0.080
0.100
0.120
0 4 8 12 16 20 24 28 32 36 40 44 48 52 56
Time, Weeks
52-W
eek
(One
-Yea
r) E
xpan
sion
, %
WY-FAF 0%WY-FAF 15%WY-FAF 25%
Figure 12.6: Effect of Class F Fly Ash on C 1293 Expansions of Aggregate A4-ID
Figure 12.7: Effect of Class F Fly Ash on C 1293 Expansions of Aggregate A2-WY
340
-0.010
0.000
0.010
0.020
0.030
0.040
0.050
0.060
0 4 8 12 16 20 24 28 32 36 40 44 48 52 56
Time, Weeks
52-W
eek
(One
-Yea
r) E
xpan
sion
, %
SD-FAF 0%SD-FAF 15%SD-FAF 25%
0.000
0.0400.080
0.1200.160
0.200
0.2400.280
0.3200.360
0.400
A4-ID A2-WY C2-SDAggregate Investigated
52-W
eek
(One
-Yea
r) E
xpan
sion
, %
0% Class F Fly Ash15% Class F Fly Ash25% Class F Fly Ash
Figure 12.8: Effect of Class F Fly Ash on C 1293 Expansions of Aggregate C2-SD
Figure 12.9: Comparison Between the 52-week (one-year) Expansions of the Different Aggregates and Levels of Class F Fly Ash Replacement
341
Table 12.3a: C 1293 Expansions Using Class F Fly Ash Class F Fly Ash Replacement Level by weight of Cement
0% 15% 25% Time Aggregate A4-ID Expansions, %
1-week 0.019 0.009 0.015 2-week 0.026 0.011 0.017 4-week 0.039 0.016 0.020 6-week 0.092 0.020 0.026 8-week 0.141 0.022 0.027
13-week 0.216 0.032 0.034 18-week 0.267 0.033 0.034 26-week 0.319 0.036 0.038 39-week 0.350 0.039 0.032 52-week 0.379 0.047 0.032
Aggregate A2-WY Expansions, % 1-week 0.003 0.009 0.000 2-week 0.005 0.009 -0.003 4-week 0.009 0.012 0.000 6-week 0.010 0.021 0.003 8-week 0.013 0.020 0.005
13-week 0.018 0.029 0.013 18-week 0.028 0.030 0.013 26-week 0.067 0.034 0.018 39-week 0.109 0.032 0.014 52-week 0.107 0.043 0.017
Aggregate C2-SD Expansions, % 1-week 0.010 0.003 -0.005 2-week 0.006 0.008 0.000 4-week 0.015 0.009 0.002 6-week 0.017 0.015 0.004 8-week 0.019 0.016 0.007
13-week 0.025 0.017 0.007 18-week 0.030 0.024 0.012 26-week 0.043 0.032 0.016 39-week 0.051 0.030 0.015 52-week 0.053 0.035 0.019
342
From these results, it can be noted that increasing the level of Class F fly ash
caused a decrease in the one-year expansion of concrete prisms. It was not possible
to determine whether Class F fly ash should be considered effective in mitigating
ASR using the one-year expansions. This can be accomplished by using the
accelerated C 1293 results or the two-year C 1293 results. Observation on the results
are summarized in Table 12.4
Table 12.4: Effect of Class F Fly Ash on ASR Using C 1293 Class F Fly Ash
Replacement by weight of Cement Aggregate
ID C 1293 One-
Year Expansion C 1293
Classification 15% 25% A4-ID 0.379% H.R. S.R. Inconclusive
A2-WY 0.107% H.R. S.R. Inconclusive C2-SD 0.053% S.R. Inconclusive Inconclusive H.R. = Highly Reactive = C 1293 one-year expansion > 0.070% S.R. = Slowly Reactive = 0.040% < C 1293 one-year expansion < 0.070%
Innocuous = C 1293 one-year expansion < 0.040% Inconclusive = C 1293 two-year expansion not available
12.2.3 Effect of Silica Fume Using C 1293
In order to investigate the effect of silica fume on the expansions due to ASR, two
levels of cement replacement were investigated, namely 5 and 10%. The three
aggregates identified in Table 12.1 were used to prepare the various mixtures listed
in Table 7.14. Results for these procedures are illustrated in Table 12.5 and Figures
12.10 through 12.12. A comparison of the one-year expansions of the various
replacement levels is shown in Figure 12.13. As mentioned in Figure 12.1, a failure
limit of 0.040% at two years was used to evaluate the use of silica fume.
343
Table 12.5: C 1293 Expansions Using Silica Fume Silica Fume Replacement Level by Weight of Cement
0% 5% 10% Time Aggregate A4-ID, Expansion, %
1-week 0.019 0.018 0.008 2-week 0.026 0.020 0.005 4-week 0.039 0.025 0.014 6-week 0.092 0.028 0.016 8-week 0.141 0.031 0.015
13-week 0.216 0.034 0.022 18-week 0.267 0.039 0.025 26-week 0.319 0.043 0.026 39-week 0.350 0.043 0.027 52-week 0.379 0.054 0.033
Aggregate A2-WY Expansions, % 1-week 0.003 0.008 0.005 2-week 0.005 0.011 0.007 4-week 0.009 0.015 0.011 6-week 0.010 0.016 0.011 8-week 0.013 0.020 0.014
13-week 0.018 0.024 0.015 18-week 0.028 0.029 0.022 26-week 0.067 0.037 0.025 39-week 0.109 0.033 0.027 52-week 0.107 0.040 0.028
Aggregate C2-SD Expansions, % 1-week 0.010 0.014 0.001 2-week 0.006 0.015 0.006 4-week 0.015 0.018 0.002 6-week 0.017 0.021 0.002 8-week 0.019 0.022 0.005
13-week 0.025 0.029 0.007 18-week 0.030 0.036 0.012 26-week 0.043 0.040 0.020 39-week 0.051 0.043 0.018 52-week 0.053 0.041 0.016
344
0.0000.0400.0800.1200.1600.2000.2400.2800.3200.3600.400
0 4 8 12 16 20 24 28 32 36 40 44 48 52 56
Time, Weeks
52-W
eek
(One
-Yea
r) E
xpan
sion
, %
ID-SF 0%ID-SF 5%ID-SF 10%
0.000
0.020
0.040
0.060
0.080
0.100
0.120
0 4 8 12 16 20 24 28 32 36 40 44 48 52 56
Time, Weeks
52-W
eek
(One
-Yea
r) E
xpan
sion
, %
WY-SF 0%WY-SF 5%WY-SF 10%
Figure 12.10: Effect of Silica Fume on C 1293 Expansions of Aggregate A4-ID
Figure 12.11: Effect of Silica Fume on C 1293 Expansions of Aggregate A2-WY
345
0.000
0.010
0.020
0.030
0.040
0.050
0.060
0 4 8 12 16 20 24 28 32 36 40 44 48 52 56
Time, Weeks
52-W
eek
(One
-Yea
r) E
xpan
sion
, %
SD-SF 0%SD-SF 5%SD-SF 10%
0.000
0.0400.080
0.1200.160
0.200
0.2400.280
0.3200.360
0.400
A4-ID A2-WY C2-SDAggregate Investigated
52-W
eek
(One
-Yea
r) E
xpan
sion
, %
0% Silica Fume5% Silica Fume10% Silica Fume
Figure 12.12: Effect of Silica Fume on C 1293 Expansions of Aggregate C2-SD
Figure 12.13: Comparison Between the 52-week (one-year) Expansions of the Different Aggregates and Levels of Silica Fume Replacement
346
An examination of these results is presented in Table 12.6 where it can be seen
that using 5% silica fume by mass was not effective with any of the aggregates in
decreasing the one-year expansions below the limit of 0.040%. The effect of using
10% silica fume by mass could not be determined using the one-year criterion. This
is accomplished using the accelerated C 1293. it should be noted that one-year
expansions decreased as the silica fume dosage increased.
Table 12.6: Effect of Silica Fume on ASR Using C 1293 Silica Fume
Replacement by weight of Cement Aggregate
ID C 1293 One-
Year Expansion C 1293
Classification 5% 10% A4-ID 0.379% H.R. S.R. Inconclusive
A2-WY 0.107% H.R. S.R. Inconclusive C2-SD 0.053% S.R. S.R. Inconclusive H.R. = Highly Reactive = C 1293 one-year expansion > 0.070% S.R. = Slowly Reactive = 0.040% < C 1293 one-year expansion < 0.070%
Innocuous = C 1293 one-year expansion < 0.040% Inconclusive = C 1293 two-year expansion not available
12.2.4 Effect of Granulated Slag Using C 1293
In order to investigate the effect of granulated slag on the expansions due to ASR,
three levels of cement replacement were investigated, namely 25, 55, and 70%. The
three aggregates identified in Table 12.1 were used to prepare the various mixtures
listed in Table 7.17. Results for these procedures are illustrated in Table 12.7 and
Figures 12.14 through 12.16. A comparison of the one-year expansions of the various
replacement levels is shown in Figure 12.17. As mentioned in Figure 12.1, a failure
limit of 0.040% at two years was used to evaluate the use of granulated slag.
347
Table 12.7: C 1293 Expansions Using Granulated Slag Granulated Slag Replacement Level by Weight of Cement
0% 25% 55% 70% Time Aggregate A4-ID Expansions, %
1-week 0.019 0.004 -0.001 0.006 2-week 0.026 0.008 0.004 0.008 4-week 0.039 0.016 0.002 0.014 6-week 0.092 0.022 0.004 0.015 8-week 0.141 0.025 0.003 0.016
13-week 0.216 0.065 0.011 0.024 18-week 0.267 0.167 0.014 0.026 26-week 0.319 0.277 0.014 0.026 39-week 0.350 0.345 0.014 0.023 52-week 0.379 0.363 0.021 0.025
Aggregate A2-WY Expansions, % 1-week 0.003 0.003 0.002 0.001 2-week 0.005 0.004 0.004 0.002 4-week 0.009 0.011 0.003 0.002 6-week 0.010 0.015 0.006 0.003 8-week 0.013 0.021 0.011 0.006
13-week 0.018 0.027 0.016 0.009 18-week 0.028 0.031 0.018 0.014 26-week 0.067 0.036 0.019 0.017 39-week 0.109 0.036 0.018 0.010 52-week 0.107 0.043 0.021 0.017
Aggregate C2-SD Expansions, % 1-week 0.010 0.006 0.000 0.003 2-week 0.006 0.009 0.003 0.007 4-week 0.015 0.016 0.007 0.010 6-week 0.017 0.015 0.013 0.012 8-week 0.019 0.020 0.013 0.011
13-week 0.025 0.026 0.017 0.018 18-week 0.030 0.032 0.019 0.021 26-week 0.043 0.036 0.021 0.019 39-week 0.051 0.033 0.023 0.017 52-week 0.053 0.045 0.022 0.017
348
-0.0400.0000.0400.0800.1200.1600.2000.2400.2800.3200.3600.400
0 4 8 12 16 20 24 28 32 36 40 44 48 52 56
Time, Weeks
52-W
eek
(One
-Yea
r) E
xpan
sion
, %
ID-SL 0%ID-SL 25%ID-SL 55%ID-SL 70%
0.000
0.020
0.040
0.060
0.080
0.100
0.120
0 4 8 12 16 20 24 28 32 36 40 44 48 52 56
Time, Weeks
52-W
eek
(One
-Yea
r) E
xpan
sion
, %
WY-SL 0%WY-SL 25%WY-SL 55%WY-SL 70%
Figure 12.14: Effect of Slag on C 1293 Expansions of Aggregate A4-ID
Figure 12.15: Effect of Slag on C 1293 Expansions of Aggregate A2-WY
349
0.000
0.010
0.020
0.030
0.040
0.050
0.060
0 4 8 12 16 20 24 28 32 36 40 44 48 52 56
Time, Weeks
52-W
eek
(One
-Yea
r) E
xpan
sion
, %
SD-SL 0%SD-SL 25%SD-SL 55%SD-SL 70%
0.000
0.0400.080
0.1200.160
0.200
0.2400.280
0.3200.360
0.400
A4-ID A2-WY C2-SDAggregate Investigated
52-W
eek
(One
-Yea
r) E
xpan
sion
, % 0% Slag25% Slag55% Slag70% Slag
Figure 12.16: Effect of Slag on C 1293 Expansions of Aggregate C2-SD
Figure 12.17: Comparison Between the 52-week (one-year) Expansions of the Different Aggregates and Levels of Slag Replacement
350
An examination of these results is presented in Table 12.8 where it can be seen
that Replacing 25% of the weight of cement with granulated slag was not effective
with any of the aggregates in decreasing the one-year expansions below the limit of
0.040%. The effect of using 55 and 70% slag by mass could not be determined using
the one-year criterion. This is accomplished using the accelerated C 1293. It should
be noted that for all three aggregates, the one-year expansions decreased as the
percentage of slag in the mixture increased.
Table 12.8: Effect of Granulated Slag on ASR Using C 1293 Granulated Slag
Replacement by Weight of Cement Aggregate
ID
C 1293 One-Year Expansion
C 1293 Classification 25% 55% 70%
A4-ID 0.379% H.R. H.R. Inconclusive Inconclusive A2-WY 0.107% H.R. S.R. Inconclusive Inconclusive C2-SD 0.053% S.R. S.R. Inconclusive Inconclusive H.R. = Highly Reactive = C 1293 one-year expansion > 0.070% S.R. = Slowly Reactive = 0.040% < C 1293 one-year expansion < 0.070%
Innocuous = C 1293 one-year expansion < 0.040% Inconclusive = C 1293 two-year expansion not available
12.2.5 Effect of Calcined Clay Using C 1293
In order to investigate the effect of calcined clay on the expansions due to ASR,
two levels of cement replacement were investigated, namely 17 and 25%. The three
aggregates identified in Table 12.1 were used to prepare the various mixtures listed
in Table 7.18. Results for these procedures are illustrated in Table 12.9 and Figures
12.18 through 12.20. A comparison of the one-year expansions of the various
replacement levels is shown in Figure 12.21. As mentioned in Figure 12.1, a failure
limit of 0.040% at two years was used to evaluate the use of calcined clay.
351
Table 12.9: C 1293 Expansions Using Calcined Clay Calcined Clay Replacement Level by Weight of Cement
0% 17% 25% Time Aggregate A4-ID, Expansion, %
1-week 0.019 0.010 -0.004 2-week 0.026 0.011 0.002 4-week 0.039 0.017 0.006 6-week 0.092 0.017 0.007 8-week 0.141 0.020 0.008
13-week 0.216 0.025 0.011 18-week 0.267 0.027 0.014 26-week 0.319 0.024 0.010 39-week 0.350 0.028 0.012 52-week 0.379 0.030 0.017
Aggregate A2-WY Expansions, % 1-week 0.003 0.003 -0.001 2-week 0.005 0.012 0.003 4-week 0.009 0.012 0.004 6-week 0.010 0.017 0.008 8-week 0.013 0.019 0.011
13-week 0.018 0.023 0.015 18-week 0.028 0.026 0.017 26-week 0.067 0.019 0.013 39-week 0.109 0.026 0.014 52-week 0.107 0.029 0.016
Aggregate C2-SD Expansions, % 1-week 0.010 0.000 0.000 2-week 0.006 0.002 0.000 4-week 0.015 0.000 0.003 6-week 0.017 0.006 0.006 8-week 0.019 0.006 0.006
13-week 0.025 0.010 0.005 18-week 0.030 0.011 0.013 26-week 0.043 0.007 0.007 39-week 0.051 0.011 0.013 52-week 0.053 0.013 0.011
352
-0.0400.0000.0400.0800.1200.1600.2000.2400.2800.3200.3600.400
0 4 8 12 16 20 24 28 32 36 40 44 48 52 56
Time, Weeks
52-W
eek
(One
-Yea
r) E
xpan
sion
, %
ID-CC 0%ID-CC 17%ID-CC 25%
-0.020
0.000
0.020
0.040
0.060
0.080
0.100
0.120
0 4 8 12 16 20 24 28 32 36 40 44 48 52 56
Time, Weeks
52-W
eek
(One
-Yea
r) E
xpan
sion
, %
WY-CC 0%WY-CC 17%WY-CC 25%
Figure 12.18: Effect of Calcined Clay on C 1293 Expansions of Aggregate A4-ID
Figure 12.19: Effect of Calcined Clay on C 1293 Expansions of Aggregate A2-WY
353
-0.010
0.000
0.010
0.020
0.030
0.040
0.050
0.060
0 4 8 12 16 20 24 28 32 36 40 44 48 52 56
Time, Weeks
52-W
eek
(One
-Yea
r) E
xpan
sion
, %
SD-CC 0%SD-CC 17%SD-CC 25%
0.000
0.0400.080
0.1200.160
0.200
0.2400.280
0.3200.360
0.400
A4-ID A2-WY C2-SDAggregate Investigated
52-W
eek
(One
-Yea
r) E
xpan
sion
, %
0% Calcined Clay17% Clacined Clay25% Calcined Clay
Figure 12.20: Effect of Calcined Clay on C 1293 Expansions of Aggregate C2-SD
Figure 12.21: Comparison Between the 52-week (one-year) Expansions of the Different Aggregates and Levels of Calcined Clay Replacement
354
Observations deducted from these results are presented in Table 12.10 where it
can be seen that the effect of using calcined clay could not be determined using the
one-year criterion. This is accomplished using the accelerated C 1293. It should be
noted, that the one-year expansions decreased as the percentage of calcined clay
increased.
Table 12.10: Effect of Calcined Clay on ASR Using C 1293 Calcined Clay
Replacement by weight of Cement Aggregate
ID C 1293 One-
Year Expansion C 1293
Classification 17% 25% A4-ID 0.379% H.R. Inconclusive Inconclusive
A2-WY 0.107% H.R. Inconclusive Inconclusive C2-SD 0.053% S.R. Inconclusive Inconclusive H.R. = Highly Reactive = C 1293 one-year expansion > 0.070% S.R. = Slowly Reactive = 0.040% < C 1293 one-year expansion < 0.070%
Innocuous = C 1293 one-year expansion < 0.040% Inconclusive = C 1293 two-year expansion not available
355
12.2.6 Effect of Lithium Nitrate (LiNO3) Using C 1293
In order to investigate the effect of LiNO3 on the expansions due to ASR, a
volume of the mixing water was replaced with a LiNO3 solution. The replaced
volume of water was equal to 85% of the volume of LiNO3 added. The dosages of
LiNO3 were as follows:
1. 3.5 liters of LiNO3 per 1 kg of Na2O in the mixture (315 g of LiNO3 for concrete
mixtures)
2. 4.6 liters of LiNO3 per 1 kg of Na2O in the mixture (495 g of LiNO3 for concrete
mixtures)
3. 10.0 liters of LiNO3 per 1 kg of Na2O in the mixture (900 g of LiNO3 for
concrete mixtures)
Mixture proportions were listed in Table 7.19. Results for these procedures are
illustrated in Table 12.11 and Figures 12.22 through 12.24. A comparison of the one-
year expansions of the various lithium dosages is shown in Figure 12.25. As
mentioned in Figure 12.1, a failure limit of 0.040% at one year is used to evaluate the
use of lithium nitrate.
356
Table 12.11: C 1293 Expansions Using Lithium Nitrate Weight of Lithium Nitrate
0g 315g 495g 900g Time Aggregate A4-ID Expansions, %
1-week 0.019 0.003 0.007 0.007 2-week 0.026 0.007 0.012 0.007 4-week 0.039 0.013 0.017 0.014 6-week 0.092 0.015 0.020 0.016 8-week 0.141 0.021 0.023 0.018
13-week 0.216 0.028 0.025 0.022 18-week 0.267 0.035 0.027 0.022 26-week 0.319 0.054 0.025 0.022 39-week 0.350 0.067 0.026 0.027 52-week 0.379 0.074 0.024 0.027
Aggregate A2-WY Expansions, % 1-week 0.003 0.002 0.007 0.007 2-week 0.005 0.002 0.012 0.007 4-week 0.009 0.011 0.017 0.011 6-week 0.010 0.012 0.020 0.012 8-week 0.013 0.016 0.023 0.016
13-week 0.018 0.019 0.025 0.019 18-week 0.028 0.024 0.027 0.022 26-week 0.067 0.020 0.025 0.019 39-week 0.109 0.029 0.026 0.018 52-week 0.107 0.046 0.024 0.016
Aggregate C2-SD Expansions, % 1-week 0.010 0.007 0.002 0.001 2-week 0.006 0.016 0.010 0.009 4-week 0.015 0.020 0.013 0.012 6-week 0.017 0.019 0.013 0.010 8-week 0.019 0.024 0.016 0.014
13-week 0.025 0.029 0.022 0.019 18-week 0.030 0.029 0.024 0.017 26-week 0.043 0.029 0.020 0.014 39-week 0.051 0.032 0.027 0.023 52-week 0.053 0.041 0.023 0.018
357
0.0000.0400.0800.1200.1600.2000.2400.2800.3200.3600.400
0 4 8 12 16 20 24 28 32 36 40 44 48 52 56
Time, Weeks
52-W
eek
(One
-Yea
r) E
xpan
sion
, %
ID-LI 0gID-LI 315gID-LI 495gID-LI 900g
0.000
0.020
0.040
0.060
0.080
0.100
0.120
0 4 8 12 16 20 24 28 32 36 40 44 48 52 56
Time, Weeks
52-W
eek
(One
-Yea
r) E
xpan
sion
, %
WY-LI 0gWY-LI 315gWY-LI 495gWY-LI 900g
Figure 12.22: Effect of Lithium Nitrate on C 1293 Expansions of Aggregate A4-ID
Figure 12.23: Effect of Lithium Nitrate on C 1293 Expansions of Aggregate A2-WY
358
0.000
0.010
0.020
0.030
0.040
0.050
0.060
0 4 8 12 16 20 24 28 32 36 40 44 48 52 56
Time, Weeks
52-W
eek
(One
-Yea
r) E
xpan
sion
, %
SD-LI 0gSD-LI 315gSD-LI 495gSD-LI 900g
0.000
0.0400.080
0.1200.160
0.200
0.2400.280
0.3200.360
0.400
A4-ID A2-WY C2-SDAggregate Investigated
52-W
eek
(One
-Yea
r) E
xpan
sion
, % 0g Lithim Nitrate315g Lithim Nitrate495g Lithim Nitrate900g Lithim Nitrate
Figure 12.24: Effect of Lithium Nitrate on C 1293 Expansions of Aggregate C2-SD
Figure 12.25: Comparison Between the 52-week (one-year) Expansions of the Different Aggregates and Levels of Lithium Nitrate
359
From these results, it can be seen that using 315g of lithium nitrate (3.5 L) to
replace part of the mixing water was not effective, with any of the three aggregates,
in decreasing the one-year expansions below 0.040%. All three aggregates required a
minimum of 495g (4.6 L) of LiNO3 in order to decrease the one-year expansions of
concrete prisms below 0.040%. As can be seen in Figure 12.25, minimal benefit in
decreasing the one-year expansions was obtained by increasing the LiNO3 dosage
from 495g (4.6 L) to 900g (10.0 L). In fact, for aggregate A4-ID, the one-year
expansion of concrete with 900g LiNO3 was slightly higher than the concrete with
495g (4.6 L) LiNO3; however, the 900g LiNO3 was still showing innocuous
expansions. Thus, for minimizing deleterious expansions due to ASR, a minimum of
495g (4.6 L) of LiNO3 was required to replace part of the mixing water (The
replaced volume of water was equal to 85% of the volume of LiNO3 added).
Additional LiNO3 might not be very beneficial. These observations are summarized
in Table 12.12.
Table 12.12: Effect of Lithium Nitrate on ASR Using C 1293 Lithium Nitrate Weight
Aggregate ID
C 1293 One-Year Expansion
C 1293 Classification 315 g 495 g 900 g
A4-ID 0.379% H.R. H.R. Innocuous Innocuous A2-WY 0.107% H.R. S.R. Innocuous Innocuous C2-SD 0.053% S.R. S.R. Innocuous Innocuous H.R. = Highly Reactive = C 1293 one-year expansion > 0.070% S.R. = Slowly Reactive = 0.040% < C 1293 one-year expansion < 0.070%
Innocuous = C 1293 one-year expansion < 0.040%
360
12.2.7 Effect of Air Entrainment Using C 1293
In order to investigate the effect of air entrainment (AE) on the expansions due to
ASR, two ranges of entrained air were investigated namely, between 2 and 4%
labeled AE 4% and between 6 and 8% labeled AE 8%. Entrained air refers to total air
content reduced by the entrapped air content. The three aggregates, mentioned Table
12.1, were used to prepare the different mixtures listed in Table 7.13. Results for
these procedures are illustrated in Figures 12.26 through 11.28 and Table 12.13. A
comparison between the one-year expansions of the different air levels is shown in
Figure 12.29.
0.000
0.050
0.100
0.150
0.200
0.250
0.300
0.350
0.400
0.450
0 4 8 12 16 20 24 28 32 36 40 44 48 52 56
Time, Weeks
52-W
eek
(One
-Yea
r) E
xpan
sion
, %
ID-AE 0%ID-AE 2-4%ID-AE 6-8%
Figure 12.26: Effect of Air Entrainment on C 1293 Expansions of Aggregate A4-ID
361
0.000
0.020
0.040
0.060
0.080
0.100
0.120
0 4 8 12 16 20 24 28 32 36 40 44 48 52 56
Time, Weeks
52-W
eek
(One
-Yea
r) E
xpan
sion
, %
WY-AE 0%WY-AE 2-4%WY-AE 6-8%
0.000
0.010
0.020
0.030
0.040
0.050
0.060
0 4 8 12 16 20 24 28 32 36 40 44 48 52 56
Time, Weeks
52-W
eek
(One
-Yea
r) E
xpan
sion
, %
SD-AE 0%SD-AE 4%SD-AE 8%
Figure 12.27: Effect of Air Entrainment on C 1293 Expansions of Aggregate A2-WY
Figure 12.28: Effect of Air Entrainment on C 1293 Expansions of Aggregate C2-SD
362
0.000
0.050
0.100
0.150
0.200
0.250
0.300
0.350
0.400
0.450
A4-ID A2-WY C2-SD
Aggregate Investigated
52-W
eek
(One
-Yea
r) E
xpan
sion
, %
0% Air2-4% Air6-8% Air
Figure 12.29: Comparison Between the 52-week (one-year) Expansions of the Different Aggregates and Air Entrainment Contents
363
Table 12.13: C 1293 Expansions Using Air Entrainment Air Entrainment Content
0% 2 to 4% 6 to 8% Time Aggregate A4-ID, Expansion, %
1-week 0.019 0.005 0.004 2-week 0.026 0.018 0.011 4-week 0.039 0.027 0.023 6-week 0.092 0.038 0.034 8-week 0.141 0.058 0.041
13-week 0.216 0.127 0.069 18-week 0.267 0.193 0.100 26-week 0.319 0.281 0.162 39-week 0.350 0.310 0.223 52-week 0.379 0.382 0.267
Aggregate A2-WY Expansions, % 1-week 0.003 0.004 0.010 2-week 0.005 0.007 0.011 4-week 0.009 0.015 0.017 6-week 0.010 0.021 0.025 8-week 0.013 0.024 0.023
13-week 0.018 0.031 0.032 18-week 0.028 0.042 0.041 26-week 0.067 0.053 0.049 39-week 0.109 0.069 0.055 52-week 0.107 0.083 0.060
Aggregate C2-SD Expansions, % 1-week 0.010 0.011 0.012 2-week 0.006 0.010 0.011 4-week 0.015 0.012 0.014 6-week 0.017 0.016 0.014 8-week 0.019 0.019 0.017
13-week 0.025 0.028 0.023 18-week 0.030 0.033 0.028 26-week 0.043 0.044 0.040 39-week 0.051 0.049 0.045 52-week 0.053 0.052 0.042
364
An examination of these results generated the comments listed in Table 12.14
where it can be noted that using air entrainment to mitigate the alkali-silica reactivity
of aggregates investigated was not effective.
Table 12.14: Effect of Air Entrainment on ASR Using C 1293 Air Entrainment Content
Aggregate ID
C 1293 One-Year Expansion
C 1293 Classification 2 to 4% 6 to 8%
A4-ID 0.379% H.R. H.R. H.R. A2-WY 0.107% H.R. H.R. S.R. C2-SD 0.053% S.R. S.R. S.R. H.R. = Highly Reactive = C 1293 one-year expansion > 0.070% S.R. = Slowly Reactive = 0.040% < C 1293 one-year expansion < 0.070%
Innocuous = C 1293 one-year expansion < 0.040% Inconclusive = C 1293 two-year expansion not available
As can be seen in Figure 12.29, for aggregate A4-ID, concretes with 2 to 4% and
6 to 8% entrained air exhibited higher one-year expansions than the control concrete
with no entrained air. The concrete with 6 to 8% entrained air showed one-year
expansion lower than the concrete with 2 to 4%. For A2-WY and C2-SD, the one-
year expansions decreased as the entrained air content increased; however, the
expansions were still higher than 0.040%. Thus, using 2 to 4% entrained air has an
adverse effect on the mitigation of the alkali-silica reactivity of highly reactive
aggregates. Using 6 to 8% entrained air decreased the one-year expansions of all
aggregates, but not to safe limits. It can be concluded that air entrainment is not an
effective alternative for mitigating ASR.
In order to further proof the inadequacy of air entrainment in mitigating the alkali-
silica reactivity of aggregates, one highly reactive aggregate, A6-NM, was added to
the investigation and additional air entrainment levels were investigated as indicated
in Table 12.15.
365
Table 12.15: Additional C 1293 Expansions Using Air Entrainment Air Entrainment Content
0 - 2% 2 – 4% 4 – 6% 6 – 8% Time Aggregate A6-NM Expansions, %
1-week 0.003 0.002 0.003 0.005 2-week 0.006 0.004 0.008 0.009 4-week 0.044 0.025 0.023 0.025 6-week 0.142 0.066 0.047 0.042 8-week 0.232 0.127 0.076 0.064
13-week 0.377 0.188 0.149 0.122 18-week 0.456 0.313 0.212 0.173 26-week 0.553 0.395 0.296 0.252 39-week 0.633 0.439 0.334 0.302 52-week 0.749 0.499 0.386 0.357
Aggregate A4-ID Expansions, % 1-week 0.005 0.005 -0.002 0.004 2-week 0.018 0.018 -0.002 0.011 4-week 0.028 0.027 0.002 0.023 6-week 0.054 0.038 0.012 0.034 8-week 0.097 0.058 0.024 0.041
13-week 0.209 0.127 0.077 0.069 18-week 0.286 0.193 0.134 0.100 26-week 0.353 0.281 0.211 0.162 39-week 0.400 0.310 0.261 0.223 52-week 0.455 0.382 0.301 0.267
Aggregate A2-WY Expansions, % 1-week 0.008 0.004 0.008 0.010 2-week 0.014 0.007 0.017 0.011 4-week 0.018 0.015 0.026 0.017 6-week 0.024 0.021 0.032 0.025 8-week 0.027 0.024 0.036 0.023
13-week 0.034 0.031 0.043 0.032 18-week 0.048 0.042 0.053 0.041 26-week 0.072 0.053 0.067 0.049 39-week 0.091 0.069 0.077 0.055 52-week 0.110 0.083 0.099 0.060
366
A comparison between the one-year expansions of the different aggregates and air
entrainment contents listed in Table 12.15 is included in Figure 12.30.
0.000
0.100
0.200
0.300
0.400
0.500
0.600
0.700
0.800
A6-NM A4-ID A2-WYAggregate Investigated
52-W
eek
(One
-Yea
r) E
xpan
sion
, % 0% Air0-2% Air2-4% Air4-6% Air 6-8% Air
It can be seen from Figure 12.30 that for concrete prisms made with the highly
reactive aggregates A6-NM and A4-ID, 4 to 6% entrained air was required to slightly
decrease the one-year expansions below the concrete with no entrained air. Lower
entrained air contents caused the one-year expansions to increase. With all three
aggregates, using up to 8% entrained air was not effective in decreasing the one-year
expansions of concrete prisms below the safe limit of 0.040%. Thus, air entrainment
could not be used to mitigate ASR.
Figure 12.30: Comparison Between the 52-week (one-year) Expansions of the Different Aggregates and Air Entrainment Contents of Table 12.15
367
12.3 COMPARISON BETWEEN ONE YEAR C 1293 RESULTS AND
13-WEEK ACCELERATED C 1293 RESULTS
The accelerated C 1293, consisting of performing the same procedure as the
standard C 1293 with the exception of storing the containers at 600C instead of 380C,
was also used to investigate the effectiveness of the different mitigation alternatives
listed in Figure 12.1. Detailed results for the accelerated C 1293 are presented in the
section 12.4. In this section, one-year expansions generated using C 1293 are
compared against the 13-week (3-month) expansions generated using the accelerated
C 1293 in order to demonstrate the effectiveness of the accelerated procedures in
producing results that are comparable to the standard C 1293. This is accomplished
in Figure 12.31 which plots the standard one-year expansions versus the accelerated
13-week expansions.
y = 0.8526x + 0.0034R2 = 0.9732
0.000
0.050
0.100
0.150
0.200
0.250
0.300
0.350
0.400
0.450
0.500
0.00 0.05 0.10 0.15 0.20 0.25 0.30 0.35 0.40 0.45 0.50 0.55
13-Week Accelerated C 1293 Expansion, %
One
-Yea
r St
anda
rd C
129
3 E
xpan
sion
, %
Figure 12.31: Comparison Between the Standard One-Year Expansions and the Accelerated 13-Week Expansions of the Various Mitigation Alternatives
368
Figure 12.31 indicates that there is a strong relationship between the two
procedures and that the accelerated procedures can produce, with high confidence,
results that are very similar to the standard procedures. This is manifested by the high
correlation that exists between expansions generated by both procedures. This
evidence coupled with the argument proposed in Chapter 10 provide the basis for
being able to use the accelerated procedures to evaluate the effectiveness of the
mitigation alternatives. As mentioned in Figure 12.1, a limit of 0.040% at 13 weeks
(corresponding to one year in the standard procedure) is used to evaluate the
effectiveness of LiNO3 and air entrainment while a limit of 0.040% at 26 weeks
(corresponding to two years in the standard procedures) is used to evaluate the
effectiveness of Class C fly ash, Class F fly ash, silica fume, granulated slag, and
calcined clay.
12.4 INVESTIGATION OF MITIGATION ALTERNATIVES USING
ACCELERATED C 1293 RESULTS
The accelerated C 1293 procedures were used to evaluate the effectiveness of
the alternatives, listed in Figure 12.1, in mitigating the alkali-silica reactivity of
aggregates listed in Table 12.1. Concrete mixtures were proportioned using a reactive
aggregate in combination with an innocuous aggregate, a cement with an alkali
content of 0.9 ± 0.1%, and the alternative being investigated. The cement alkali
content was increased to 1.25% Na2Oequiv. by adding NaOH to the mixing water. A
cementitious materials content of 710 lb/yd3 and a water-cement ratio by mass of
0.45 were used for concrete proportioning. Each mixture was used to cast three 3-in.
x 3-in. x 11-in. concrete prisms which were moist cured for 24 hours while still in
molds. Prisms were then demolded, measured for their initial length, and stored over
water, in a sealed 6-gal bucket with wicks on the sides (100% R.H.). These
procedures were identical to the procedures of the standard C 1293. The only
exception was that the buckets were stored in an environmental room maintained at a
369
temperature of 60 ± 20C. Length expansions were monitored periodically over a
period of 26 weeks. The failure criteria used with these procedures are listed in
Figure 12.1.
12.4.1 Effect of Class C Fly Ash Using Accelerated C 1293
The effect of Class C fly ash on the expansions caused by ASR was evaluated
using the accelerated C 1293 procedures. Three levels of cement replacement were
investigated, namely 20, 27.5, and 35%. Four aggregates, identified in Table 12.1,
were used to prepare the different mixtures listed in Table 7.15 (these are the same
mixtures used for the standard C 1293). Results for these procedures are illustrated in
Table 12.16 and Figures 12.32 through 12.35. A comparison of the 26-week
expansions of the various replacement levels is shown in Figure 12.36. As mentioned
in Figure 12.1, a failure limit of 0.040% at 26 weeks was used to evaluate the use of
Class C fly ash.
0.0000.0500.1000.1500.2000.2500.3000.3500.4000.4500.500
0 2 4 6 8 10 12 14 16 18 20 22 24 26 28
Time, Weeks
26-W
eek
(6-M
onth
) Exp
ansi
on, %
ID-FAC 0%ID-FAC 20%ID-FAC 27.5%ID-FAC 35%
Figure 12.32: Effect of Class C Fly Ash on the Accelerated C 1293 Expansions of Aggregate A4-ID
370
0.000
0.020
0.040
0.060
0.080
0.100
0.120
0 2 4 6 8 10 12 14 16 18 20 22 24 26 28
Time, Weeks
26-W
eek
(6-M
onth
) Exp
ansi
on, %
WY-FAC 0%WY-FAC 20%WY-FAC 27.5%WY-FAC 35%
0.000
0.010
0.020
0.030
0.040
0.050
0.060
0.070
0.080
0 2 4 6 8 10 12 14 16 18 20 22 24 26 28
Time, Weeks
26-W
eek
(6-M
onth
) Exp
ansi
on, %
SD-FAC 0%SD-FAC 20%SD-FAC 27.5%SD-FAC 35%
Figure 12.33: Effect of Class C Fly Ash on the Accelerated C 1293 Expansions of Aggregate A2-WY
Figure 12.34: Effect of Class C Fly Ash on the Accelerated C 1293 Expansions of Aggregate C2-SD
371
0.000
0.005
0.010
0.015
0.020
0.025
0.030
0.035
0 2 4 6 8 10 12 14 16 18 20 22 24 26 28
Time, Weeks
26-W
eek
(6-M
onth
) Exp
ansi
on, %
IA-FAC 0%IA-FAC 20%IA-FAC 27.5%IA-FAC 35%
0.0000.0400.0800.1200.1600.2000.2400.2800.3200.3600.4000.4400.480
A4-ID A2-WY C2-SD E2-IAAggregate Investigated
26-W
eek
(6-M
onth
) Exp
ansi
on, % 0% Class C Fly Ash
20% Class C Fly Ash27.5% Class C Fly Ash35% Class C Fly Ash
Figure 12.35: Effect of Class C Fly Ash on the Accelerated C 1293 Expansions of Aggregate E2-IA
Figure 12.36: Comparison Between the 26-Week Expansions Generated Using the Accelerated C 1293 Procedures and the Different Class C Fly Ash
Replacement Levels
372
Table 12.16: Accelerated C 1293 Expansions Using Class C Fly Ash Class C Fly Ash Replacement Level by Weight of Cement
0% 20% 27.5% 35% Time Aggregate A4-ID Expansions, %
1-week 0.058 0.023 0.009 0.007 2-week 0.141 0.036 0.019 0.011 4-week 0.324 0.064 0.032 0.017 8-week 0.353 0.085 0.040 0.025
13-week 0.396 0.101 0.050 0.038 18-week 0.424 0.108 0.061 0.045 26-week 0.440 0.117 0.069 0.050
Aggregate A2-WY Expansions, % 1-week 0.027 0.010 0.008 0.002 2-week 0.038 0.015 0.019 0.005 4-week 0.062 0.031 0.035 0.010 8-week 0.077 0.042 0.049 0.019
13-week 0.083 0.053 0.050 0.040 18-week 0.088 0.072 0.071 0.050 26-week 0.096 0.089 0.083 0.062
Aggregate C2-SD Expansions, % 1-week 0.014 0.001 0.001 0.000 2-week 0.016 0.005 0.004 0.004 4-week 0.029 0.012 0.010 0.007 8-week 0.050 0.025 0.020 0.011
13-week 0.059 0.044 0.032 0.020 18-week 0.063 0.050 0.047 0.025 26-week 0.071 0.062 0.052 0.030
Aggregate E2-IA Expansions, % 1-week 0.016 0.010 0.008 0.002 2-week 0.016 0.015 0.014 0.005 4-week 0.023 0.021 0.019 0.010 8-week 0.024 0.023 0.020 0.019
13-week 0.028 0.027 0.024 0.023 18-week 0.028 0.030 0.028 0.026 26-week 0.031 0.032 0.030 0.029
Observations related to these results are summarized in Table 12.17 where it can
be seen that replacing 25 and 27.5% of the weight of cement by Class C fly ash was
373
not effective in decreasing the 26-week expansions below 0.040% for any of A4-ID,
A2-WY, and C2-SD. Using 35% Class C fly ash was only effective with C2-SD and
not A4-ID and A2-WY. Aggregate E2-IA which was non-reactive in concrete made
with cement only, exhibited innocuous expansions also when 20, 27.5, and 35%
Class C fly ash was used to replace the cement by weight.
Table 12.17: Effect of Class C Fly Ash on ASR Using Accelerated C 1293
Class C Fly Ash Replacement by Weight of Cement
Aggregate ID
C 1293 One-Year Expansion
and Classification
Accelerated C 1293 13-Week Expansion and Classification 20% 27.5% 35%
A4-ID 0.379% Highly Reactive
0.396% Highly Reactive H.R. H.R. S.R.
A2-WY 0.107% Highly Reactive
0.083% Highly Reactive H.R. H.R. S.R.
C2-SD 0.053% Slowly Reactive
0.059% Slowly Reactive S.R. S.R. Innocuous
E2-IA 0.025% Non-Reactive
0.028% Non-Reactive Innocuous Innocuous Innocuous
H.R. = Accelerated C 1293 26-week expansion > 0.070% S.R. = 0.040% < Accelerated C 1293 26-week expansion < 0.070%
Innocuous = Accelerated C 1293 26-week expansion < 0.040%
12.4.2 Effect of Class F Fly Ash Using Accelerated C 1293
The effect of Class C fly ash on the expansions caused by ASR was evaluated
using the accelerated C 1293 procedures. Two levels of cement replacement were
investigated namely, 15 and 25%. Four aggregates, identified in Table 12.1, were
used to prepare the different mixtures listed in Table 7.16 (these are the same mixture
used for the standard C 1293). Results for these procedures are illustrated in Table
12.18 and Figures 12.37 through 12.40. A comparison between the 26-week
expansions of the various replacement levels is shown in Figure 12.41. As mentioned
in Figure 12.1, a failure limit of 0.040% at 26 weeks is used to evaluate the use of
Class F fly ash.
374
Table 12.18: Accelerated C 1293 Expansions Using Class F Fly Ash Class F Fly Ash Replacement Level by weight of Cement
0% 15% 25% Time Aggregate A4-ID Expansions, %
1-week 0.058 0.004 0.001 2-week 0.141 0.010 0.005 4-week 0.324 0.019 0.012 8-week 0.353 0.030 0.021
13-week 0.396 0.059 0.042 18-week 0.424 0.065 0.052 26-week 0.440 0.080 0.065
Aggregate A2-WY Expansions, % 1-week 0.027 0.001 0.000 2-week 0.038 0.008 0.003 4-week 0.062 0.015 0.005 8-week 0.077 0.033 0.008
13-week 0.083 0.044 0.011 18-week 0.088 0.051 0.019 26-week 0.096 0.062 0.028
Aggregate C2-SD Expansions, % 1-week 0.014 0.003 0.001 2-week 0.016 0.005 0.004 4-week 0.029 0.010 0.010 8-week 0.050 0.021 0.015
13-week 0.059 0.040 0.021 18-week 0.063 0.048 0.025 26-week 0.071 0.053 0.029
Aggregate E2-IA Expansions, % 1-week 0.016 0.010 0.008 2-week 0.016 0.013 0.011 4-week 0.023 0.019 0.017 8-week 0.024 0.023 0.019
13-week 0.028 0.024 0.022 18-week 0.028 0.027 0.024 26-week 0.031 0.030 0.029
375
0.0000.0400.0800.1200.1600.2000.2400.2800.3200.3600.4000.4400.480
0 2 4 6 8 10 12 14 16 18 20 22 24 26 28
Time, Weeks
26-W
eeks
(6-M
onth
) Exp
ansi
on, %
ID-FAF 0%ID-FAF 15%ID-FAF 25%
0.000
0.020
0.040
0.060
0.080
0.100
0.120
0 2 4 6 8 10 12 14 16 18 20 22 24 26 28
Time, Weeks
26-W
eeks
(6-M
onth
) Exp
ansi
on, %
WY-FAF 0%WY-FAF 15%WY-FAF 25%
Figure 12.37: Effect of Class F Fly Ash on the Accelerated C 1293 Expansions of Aggregate A4-ID
Figure 12.38: Effect of Class F Fly Ash on the Accelerated C 1293 Expansions of Aggregate A2-WY
376
0.000
0.010
0.020
0.030
0.040
0.050
0.060
0.070
0.080
0 2 4 6 8 10 12 14 16 18 20 22 24 26 28
Time, Weeks
26-W
eeks
(6-M
onth
) Exp
ansi
on, %
SD-FAF 0%SD-FAF 15%SD-FAF 25%
0.000
0.005
0.010
0.015
0.020
0.025
0.030
0.035
0 2 4 6 8 10 12 14 16 18 20 22 24 26 28
Time, Weeks
26-W
eeks
(6-M
onth
) Exp
ansi
on, %
IA-FAF 0%IA-FAF 15%IA-FAF 25%
Figure 12.39: Effect of Class F Fly Ash on the Accelerated C 1293 Expansions of Aggregate C2-SD
Figure 12.40: Effect of Class F Fly Ash on the Accelerated C 1293 Expansions of Aggregate E2-IA
377
0.0000.0400.0800.1200.1600.2000.2400.2800.3200.3600.4000.4400.480
A4-ID A2-WY C2-SD E2-IAAggregate Investigated
26-W
eek
(6-M
onth
) Exp
ansi
on, %
0% Class F Fly Ash15% Class F Fly Ash25% Class F Fly Ash
Observations related to these results are summarized in Table 12.19 where it can
be seen that replacing 15% of the weight of cement by Class F fly ash was not
effective in decreasing the 26-week expansions below 0.040% for any of A4-ID, A2-
WY, and C2-SD. Using 25% Class F fly ash was effective with A2-WY and C2-SD
but not A4-ID. Aggregate E2-IA, which was non-reactive in concrete made with
cement only, exhibited innocuous expansions also when 15 and 25% Class C fly ash
was used to replace the cement by weight.
Figure 12.41: Comparison Between the 26-Week Expansions Generated Using the Accelerated C 1293 Procedures and the Different Class F Fly Ash
Replacement Levels
378
Table 12.19: Effect of Class F Fly Ash on ASR Using Accelerated C 1293 Class F Fly Ash
Replacement by Weight of Cement
Aggregate ID
C 1293 One-Year Expansion
and Classification
Accelerated C 1293 13-Week Expansion and Classification 15% 25%
A4-ID 0.379% Highly Reactive
0.396% Highly Reactive H.R. S.R.
A2-WY 0.107% Highly Reactive
0.083% Highly Reactive S.R. Innocuous
C2-SD 0.053% Slowly Reactive
0.059% Slowly Reactive S.R. Innocuous
E2-IA 0.025% Non-Reactive
0.028% Non-Reactive Innocuous Innocuous
H.R. = Accelerated C 1293 26-week expansion > 0.070% S.R. = 0.040% < Accelerated C 1293 26-week expansion < 0.070%
Innocuous = Accelerated C 1293 26-week expansion < 0.040%
12.4.3 Effect of Silica Fume Using Accelerated C 1293
The effect of silica fume on the expansions caused by ASR was evaluated using
the accelerated C 1293 procedures. Two levels of cement replacement were
investigated, namely 5 and 10%. Four aggregates, identified in Table 12.1, were used
to prepare the different mixtures listed in Table 7.14 (these are the same mixtures
used for the standard C 1293). Results for these procedures are illustrated in Table
12.20 and Figures 12.42 through 12.45. A comparison between the 26-week
expansions of the various replacement levels is shown in Figure 12.46. As mentioned
in Figure 12.1, a failure limit of 0.040% at 26 weeks was used to evaluate the use of
silica fume.
379
Table 12.20: Accelerated C 1293 Expansions Using Silica Fume Silica Fume Replacement Level by weight of Cement
0% 5% 10% Time Aggregate A4-ID Expansions, %
1-week 0.058 0.004 0.002 2-week 0.141 0.010 0.006 4-week 0.324 0.028 0.013 8-week 0.353 0.042 0.020
13-week 0.396 0.079 0.041 18-week 0.424 0.088 0.049 26-week 0.440 0.099 0.055
Aggregate A2-WY Expansions, % 1-week 0.027 0.002 0.001 2-week 0.038 0.010 0.005 4-week 0.062 0.020 0.010 8-week 0.077 0.034 0.018
13-week 0.083 0.044 0.023 18-week 0.088 0.053 0.036 26-week 0.096 0.061 0.041
Aggregate C2-SD Expansions, % 1-week 0.014 0.005 0.000 2-week 0.016 0.011 0.004 4-week 0.029 0.020 0.010 8-week 0.050 0.031 0.018
13-week 0.059 0.040 0.019 18-week 0.063 0.047 0.025 26-week 0.071 0.052 0.031
Aggregate E2-IA Expansions, % 1-week 0.016 0.001 0.002 2-week 0.016 0.009 0.009 4-week 0.023 0.015 0.011 8-week 0.024 0.021 0.015
13-week 0.028 0.029 0.023 18-week 0.028 0.031 0.025 26-week 0.031 0.033 0.029
380
0.0000.0400.0800.1200.1600.2000.2400.2800.3200.3600.4000.4400.480
0 2 4 6 8 10 12 14 16 18 20 22 24 26 28
Time, Weeks
26-W
eek
(6-M
onth
) Exp
ansi
on, %
ID-SF 0%ID-SF 5%ID-SF 10%
0.000
0.020
0.040
0.060
0.080
0.100
0.120
0 2 4 6 8 10 12 14 16 18 20 22 24 26 28
Time, Weeks
26-W
eek
(6-M
onth
) Exp
ansi
on, %
WY-SF 0%WY-SF 5%WY-SF 10%
Figure 12.42: Effect of Silica Fume on the Accelerated C 1293 Expansions of Aggregate A4-ID
Figure 12.43: Effect of Silica Fume on the Accelerated C 1293 Expansions of Aggregate A2-WY
381
0.000
0.010
0.020
0.030
0.040
0.050
0.060
0.070
0.080
0 2 4 6 8 10 12 14 16 18 20 22 24 26 28
Time, Weeks
26-W
eek
(6-M
onth
) Exp
ansi
on, %
SD-SF 0%SD-SF 5%SD-SF 10%
0.000
0.005
0.010
0.015
0.020
0.025
0.030
0.035
0 2 4 6 8 10 12 14 16 18 20 22 24 26 28
Time, Weeks
26-W
eek
(6-M
onth
) Exp
ansi
on, %
IA-SF 0%IA-SF 5%IA-SF 10%
Figure 12.44: Effect of Silica Fume on the Accelerated C 1293 Expansions of Aggregate C2-SD
Figure 12.45: Effect of Silica Fume on the Accelerated C 1293 Expansions of Aggregate E2-IA
382
0.0000.0400.0800.1200.1600.2000.2400.2800.3200.3600.4000.4400.480
A4-ID A2-WY C2-SD E2-IAAggregate Investigated
26-W
eek
(6-M
onth
) Exp
ansi
on, %
0% Silica Fume5% Silica Fume10% Silica Fume
Observations related to these results are summarized in Table 12.21 where it can
be seen that replacing 5 and 10% of the weight of cement by silica fume was not
effective in decreasing the 26-week expansions below 0.040% for any of A4-ID and
A2-WY. Ten percent silica fume was needed to reduce the 26-week expansions of
aggregate C2-SD below 0.040%. Aggregate E2-IA, which was non-reactive in
concrete made with cement only, exhibited innocuous expansions also when 5 and
10% silica fume was used to replace the cement by weight.
Figure 12.46: Comparison Between the 26-Week Expansions Generated Using the Accelerated C 1293 Procedures and the Different Silica Fume
Replacement Levels
383
Table 12.21: Effect of Silica Fume on ASR Using Accelerated C 1293 Silica Fume
Replacement by Weight of Cement
Aggregate ID
C 1293 One-Year Expansion
and Classification
Accelerated C 1293 13-Week Expansion and Classification 5% 10%
A4-ID 0.379% Highly Reactive
0.396% Highly Reactive H.R. S.R.
A2-WY 0.107% Highly Reactive
0.083% Highly Reactive S.R. S.R.
C2-SD 0.053% Slowly Reactive
0.059% Slowly Reactive S.R. Innocuous
E2-IA 0.025% Non-Reactive
0.028% Non-Reactive Innocuous Innocuous
H.R. = Accelerated C 1293 26-week expansion > 0.070% S.R. = 0.040% < Accelerated C 1293 26-week expansion < 0.070%
Innocuous = Accelerated C 1293 26-week expansion < 0.040%
12.4.4 Effect of Granulated Slag Using Accelerated C 1293
The effect of granulated slag on the expansions caused by ASR was evaluated
using the accelerated C 1293 procedures. Three levels of cement replacement were
investigated, namely 25, 55, and 70%. Four aggregates, identified in Table 12.1,
were used to prepare the different mixtures listed in Table 7.17 (these are the same
mixtures used for the standard C 1293). Results for these procedures are illustrated in
Table 12.22 and Figures 12.47 through 12.50. A comparison between the 26-week
expansions of the various replacement levels is shown in Figure 12.51. As mentioned
in Figure 12.1, a failure limit of 0.040% at 26 weeks was used to evaluate the use of
granulated slag.
384
Table 12.22: Accelerated C 1293 Expansions Using Granulated Slag Granulated Slag Replacement Level by Weight of Cement
0% 25% 55% 70% Time Aggregate A4-ID Expansions, %
1-week 0.058 0.035 0.005 0.007 2-week 0.141 0.078 0.009 0.010 4-week 0.324 0.193 0.013 0.015 8-week 0.353 0.267 0.020 0.021
13-week 0.396 0.355 0.026 0.026 18-week 0.424 0.360 0.029 0.022 26-week 0.440 0.365 0.033 0.031
Aggregate A2-WY Expansions, % 1-week 0.027 0.004 0.000 0.000 2-week 0.038 0.008 0.001 0.003 4-week 0.062 0.019 0.005 0.008 8-week 0.077 0.031 0.011 0.011
13-week 0.083 0.048 0.018 0.015 18-week 0.088 0.053 0.023 0.025 26-week 0.096 0.063 0.026 0.029
Aggregate C2-SD Expansions, % 1-week 0.014 0.005 0.001 0.003 2-week 0.016 0.009 0.005 0.006 4-week 0.029 0.017 0.011 0.011 8-week 0.050 0.025 0.018 0.018
13-week 0.059 0.049 0.023 0.022 18-week 0.063 0.053 0.021 0.029 26-week 0.071 0.059 0.025 0.033
Aggregate E2-IA Expansions, % 1-week 0.016 0.014 0.009 0.008 2-week 0.016 0.016 0.011 0.009 4-week 0.023 0.020 0.015 0.011 8-week 0.024 0.025 0.019 0.013
13-week 0.028 0.029 0.023 0.020 18-week 0.028 0.032 0.024 0.021 26-week 0.031 0.033 0.026 0.025
385
0.0000.0400.0800.1200.1600.2000.2400.2800.3200.3600.4000.4400.480
0 2 4 6 8 10 12 14 16 18 20 22 24 26 28
Time, Weeks
26-W
eek
(6-M
onth
) Exp
ansi
on, %
ID-SL 0%ID-SL 25%ID-SL 55%ID-SL 70%
0.000
0.020
0.040
0.060
0.080
0.100
0.120
0 2 4 6 8 10 12 14 16 18 20 22 24 26 28
Time, Weeks
26-W
eek
(6-M
onth
) Exp
ansi
on, %
WY-SL 0%WY-SL 25%WY-SL 55%WY-SL 70%
Figure 12.47: Effect of Granulated Slag on the Accelerated C 1293 Expansions of Aggregate A4-ID
Figure 12.48: Effect of Granulated Slag on the Accelerated C 1293 Expansions of Aggregate A2-WY
386
0.000
0.010
0.020
0.030
0.040
0.050
0.060
0.070
0.080
0 2 4 6 8 10 12 14 16 18 20 22 24 26 28
Time, Weeks
26-W
eek
(6-M
onth
) Exp
ansi
on, %
SD-SL 0%SD-SL 25%SD-SL 55%SD-SL 70%
0.000
0.005
0.010
0.015
0.020
0.025
0.030
0.035
0 2 4 6 8 10 12 14 16 18 20 22 24 26 28
Time, Weeks
26-W
eek
(6-M
onth
) Exp
ansi
on, %
IA-SL 0%IA-SL 25%IA-SL 55%IA-SL 70%
Figure 12.49: Effect of Granulated Slag on the Accelerated C 1293 Expansions of Aggregate C2-SD
Figure 12.50: Effect of Granulated Slag on the Accelerated C 1293 Expansions of Aggregate E2-IA
387
0.0000.0400.0800.1200.1600.2000.2400.2800.3200.3600.4000.4400.480
A4-ID A2-WY C2-SD A2-IAAggregate Investigated
26-W
eek
(6-M
onth
) Exp
ansi
on, % 0% Slag
25% Slag55% Slag70% Slag
Observations related to these results are summarized in Table 12.23 where it can
be seen that replacing 25% of the weight of cement with granulated slag was not
effective in decreasing the 26-week expansions below 0.040% for any of A4-ID, A2-
WY, and C2-SD. A minimum of 55% granulated slag was needed to reduce the 26-
week expansions of all three aggregates below 0.040%. Aggregate E2-IA, which was
non-reactive in concrete made with cement only, exhibited innocuous expansions
also when 25, 55, and 70% granulated slag was used to replace the cement by
weight.
Figure 12.51: Comparison Between the 26-Week Expansions Generated Using the Accelerated C 1293 Procedures and the Different Granulated
Slag Replacement Levels
388
Table 12.23: Effect of Granulated Slag on ASR Using Accelerated C 1293
Granulated Slag Replacement by Weight of Cement
Aggregate ID
C 1293 One-Year Expansion
and Classification
Accelerated C 1293 13-Week Expansion and Classification 25% 55% 70%
A4-ID 0.379% Highly Reactive
0.396% Highly Reactive H.R. Innocuous Innocuous
A2-WY 0.107% Highly Reactive
0.083% Highly Reactive S.R. Innocuous Innocuous
C2-SD 0.053% Slowly Reactive
0.059% Slowly Reactive S.R. Innocuous Innocuous
E2-IA 0.025% Non-Reactive
0.028% Non-Reactive Innocuous Innocuous Innocuous
H.R. = Accelerated C 1293 26-week expansion > 0.070% S.R. = 0.040% < Accelerated C 1293 26-week expansion < 0.070%
Innocuous = Accelerated C 1293 26-week expansion < 0.040%
12.4.5 Effect of Calcined Clay Using Accelerated C 1293
The effect of calcined clay on the expansions caused by ASR was evaluated using
the accelerated C 1293 procedures. Two levels of cement replacement were
investigated, namely 17 and 25%. Four aggregates, identified in Table 12.1, were
used to prepare the different mixtures listed in Table 7.18 (these are the same
mixtures used for the standard C 1293). Results for these procedures are illustrated in
Table 12.24 and Figures 12.52 through 12.55. A comparison between the 26-week
expansions of the various replacement levels is shown in Figure 12.56. As mentioned
in Figure 12.1, a failure limit of 0.040% at 26 weeks was used to evaluate the use of
calcined clay.
389
Table 12.24: Accelerated C 1293 Expansions Using Calcined Clay Calcined Clay Replacement Level by weight of Cement
0% 17% 25% Time Aggregate A4-ID Expansions, %
1-week 0.058 0.004 0.000 2-week 0.141 0.009 0.002 4-week 0.324 0.014 0.005 8-week 0.353 0.020 0.011
13-week 0.396 0.027 0.018 18-week 0.424 0.035 0.021 26-week 0.440 0.046 0.029
Aggregate A2-WY Expansions, % 1-week 0.027 0.001 0.000 2-week 0.038 0.004 0.003 4-week 0.062 0.010 0.006 8-week 0.077 0.017 0.010
13-week 0.083 0.029 0.013 18-week 0.088 0.036 0.019 26-week 0.096 0.049 0.025
Aggregate C2-SD Expansions, % 1-week 0.014 0.000 0.000 2-week 0.016 0.001 0.000 4-week 0.029 0.005 0.003 8-week 0.050 0.009 0.008
13-week 0.059 0.015 0.015 18-week 0.063 0.019 0.019 26-week 0.071 0.023 0.021
Aggregate E2-IA Expansions, % 1-week 0.016 0.014 0.005 2-week 0.016 0.015 0.008 4-week 0.023 0.019 0.010 8-week 0.024 0.023 0.014
13-week 0.028 0.026 0.019 18-week 0.028 0.027 0.021 26-week 0.031 0.029 0.022
390
0.0000.0400.0800.1200.1600.2000.2400.2800.3200.3600.4000.4400.480
0 2 4 6 8 10 12 14 16 18 20 22 24 26 28
Time, Weeks
26-W
eek
(6-M
onth
) Exp
ansi
on, %
ID-CC 0%ID-CC 17%ID-CC 25%
0.000
0.020
0.040
0.060
0.080
0.100
0.120
0 2 4 6 8 10 12 14 16 18 20 22 24 26 28
Time, Weeks
26-W
eek
(6-M
onth
) Exp
ansi
on, %
WY-CC 0%WY-CC 17%WY-CC 25%
Figure 12.52: Effect of Calcined Clay on the Accelerated C 1293 Expansions of Aggregate A4-ID
Figure 12.53: Effect of Calcined Clay on the Accelerated C 1293 Expansions of Aggregate A2-WY
391
0.000
0.010
0.020
0.030
0.040
0.050
0.060
0.070
0.080
0 2 4 6 8 10 12 14 16 18 20 22 24 26 28
Time, Weeks
26-W
eek
(6-M
onth
) Exp
ansi
on, %
SD-CC 0%SD-CC 17%SD-CC 25%
0.000
0.005
0.010
0.015
0.020
0.025
0.030
0.035
0 2 4 6 8 10 12 14 16 18 20 22 24 26 28
Time, Weeks
26-W
eek
(6-M
onth
) Exp
ansi
on, %
IA-CC 0%IA-CC 17%IA-CC 25%
Figure 12.54: Effect of Calcined Clay on the Accelerated C 1293 Expansions of Aggregate C2-SD
Figure 12.55: Effect of Calcined Clay on the Accelerated C 1293 Expansions of Aggregate E2-IA
392
0.0000.0400.0800.1200.1600.2000.2400.2800.3200.3600.4000.4400.480
A4-ID A2-WY C2-SD E2-IAAggregate Investigated
26-W
eek
(6-M
onth
) Exp
ansi
on, %
0% Calcined Clay17% Clacined Clay25% Calcined Clay
Observations related to these results are summarized in Table 12.25 where it can
be seen that replacing 17% of the weight of cement by calcined was effective in
decreasing the 26-week expansions below 0.040% for C2-SD but not A4-ID and A2-
WY. Twenty-five percent calcined clay was needed to reduce the 26-week
expansions of all aggregates below 0.040%. Aggregate E2-IA, which was non-
reactive in concrete made with cement only, exhibited innocuous expansions also
when 17 and 25% calcined clay was used to replace the cement by weight.
Figure 12.56: Comparison Between the 26-Week Expansions Generated Using the Accelerated C 1293 Procedures and the Different Calcined Clay
Replacement Levels
393
Table 12.25: Effect of Calcined Clay on ASR Using Accelerated C 1293 Calcined Clay
Replacement by Weight of Cement
Aggregate ID
C 1293 One-Year Expansion
and Classification
Accelerated C 1293 13-Week Expansion and Classification 17% 25%
A4-ID 0.379% Highly Reactive
0.396% Highly Reactive S.R. Innocuous
A2-WY 0.107% Highly Reactive
0.083% Highly Reactive S.R. Innocuous
C2-SD 0.053% Slowly Reactive
0.059% Slowly Reactive Innocuous Innocuous
E2-IA 0.025% Non-Reactive
0.028% Non-Reactive Innocuous Innocuous
H.R. = Accelerated C 1293 26-week expansion > 0.070% S.R. = 0.040% < Accelerated C 1293 26-week expansion < 0.070%
Innocuous = Accelerated C 1293 26-week expansion < 0.040%
12.4.6 Effect of Lithium Nitrate (LiNO3) Using Accelerated C 1293
The effect of LiNO3 on the expansions caused by ASR was evaluated using the
accelerated C 1293 procedures. The effects of three dosages were investigated:
1. 3.5 liters of LiNO3 per 1 kg of Na2O in the mixture (315 g of LiNO3 for concrete
mixtures)
2. 4.6 liters of LiNO3 per 1 kg of Na2O in the mixture (495 g of LiNO3 for concrete
mixtures)
3. 10.0 liters of LiNO3 per 1 kg of Na2O in the mixture (900 g of LiNO3 for
concrete mixtures)
A volume of the mixing water equal to 85% of the volume of LiNO3 added was
replaced by the LiNO3 solution according to the dosages mentioned. Four aggregates,
identified in Table 12.1, were used to prepare the different mixtures listed in Table
7.19 (these are the same mixture used for the standard C 1293). Results for these
procedures are illustrated in Table 12.26 and Figures 12.57 through 12.60. A
comparison between the 26-week expansions of the various replacement levels is
394
shown in Figure 12.61. As mentioned in Figure 12.1, a failure limit of 0.040% at 13
weeks is used to evaluate the use of lithium nitrate.
Table 12.26: Accelerated C 1293 Expansions Using Lithium Nitrate
Lithium Nitrate Weight 0g 315g 495g 900g Time
Aggregate A4-ID Expansions, % 1-week 0.058 0.029 0.009 0.006 2-week 0.141 0.042 0.015 0.010 4-week 0.324 0.064 0.020 0.017 8-week 0.353 0.072 0.025 0.024
13-week 0.396 0.085 0.029 0.030 18-week 0.424 0.100 0.030 0.031 26-week 0.440 0.111 0.035 0.033
Aggregate A2-WY Expansions, % 1-week 0.027 0.007 0.004 0.002 2-week 0.038 0.012 0.009 0.006 4-week 0.062 0.022 0.013 0.011 8-week 0.077 0.030 0.019 0.015
13-week 0.083 0.042 0.025 0.020 18-week 0.088 0.049 0.026 0.021 26-week 0.096 0.058 0.028 0.025
Aggregate C2-SD Expansions, % 1-week 0.014 0.008 0.003 0.000 2-week 0.016 0.015 0.007 0.005 4-week 0.029 0.022 0.015 0.010 8-week 0.050 0.031 0.020 0.018
13-week 0.059 0.040 0.030 0.022 18-week 0.063 0.042 0.031 0.025 26-week 0.071 0.046 0.033 0.028
Aggregate E2-IA Expansions, % 1-week 0.016 0.011 0.009 0.001 2-week 0.016 0.016 0.016 0.006 4-week 0.023 0.019 0.018 0.012 8-week 0.024 0.022 0.021 0.018
13-week 0.028 0.028 0.026 0.023 18-week 0.028 0.031 0.028 0.026 26-week 0.031 0.033 0.030 0.029
395
0.0000.0400.0800.1200.1600.2000.2400.2800.3200.3600.4000.440
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14
Time, Weeks
13-W
eek
(3-M
onth
) Exp
ansi
on, %
ID-LI 0gID-LI 315gID-LI 495gID-LI 900g
0.000
0.010
0.020
0.030
0.040
0.050
0.060
0.070
0.080
0.090
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14
Time, Weeks
13-W
eek
(3-M
onth
) Exp
ansi
on, %
WY-LI 0gWY-LI 315gWY-LI 495gWY-LI 900g
Figure 12.57: Effect of Lithium Nitrate on the Accelerated C 1293 Expansions of Aggregate A4-ID
Figure 12.58: Effect of Lithium Nitrate on the Accelerated C 1293 Expansions of Aggregate A2-WY
396
0.000
0.010
0.020
0.030
0.040
0.050
0.060
0.070
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14
Time, Weeks
13-W
eek
(3-M
onth
) Exp
ansi
on, %
SD-LI 0gSD-LI 315gSD-LI 495gSD-LI 900g
0.000
0.005
0.010
0.015
0.020
0.025
0.030
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14
Time, Weeks
13-W
eek
(3-M
onth
) Exp
ansi
on, %
IA-LI 0gIA-LI 315gIA-LI 495gIA-LI 900g
Figure 12.59: Effect of Lithium Nitrate on the Accelerated C 1293 Expansions of Aggregate C2-SD
Figure 12.60: Effect of Lithium Nitrate on the Accelerated C 1293 Expansions of Aggregate E2-IA
397
0.0000.0400.0800.1200.1600.2000.2400.2800.3200.3600.4000.440
A4-ID A2-WY C2-SD A2-IAAggregate Investigated
13-W
eek
(3-M
onth
) Exp
ansi
on, % 0g Lithim Nitrate
315g Lithim Nitrate495g Lithim Nitrate900g Lithim Nitrate
Observations related to these results are summarized in Table 12.27 where it can
be seen that these results are identical to the ones generated using the standard C
1293 and summarized in Table 12.12. Using 315g of lithium nitrate (3.5 L) to replace
part of the mixing water was not effective in decreasing the 13-week expansions
below 0.040% for any of A4-ID, A2-WY, and C2-SD. All three aggregates required
a minimum of 495g (4.6 L) of LiNO3 in order to decrease the 13-week expansions of
concrete prisms below 0.040%. As can be seen in Figure 12.61, minimal benefit in
decreasing expansions was obtained by increasing the LiNO3 dosage from 495g (4.6
L) to 900g (10.0 L). Thus, for minimizing deleterious expansions due to ASR, a
minimum of 495g (4.6 L) of LiNO3 was required to replace part of the mixing water
(The replaced volume of water was equal to 85% of the volume of LiNO3 added).
Additional LiNO3 might not be very beneficial. Aggregate E2-IA, which was non-
Figure 12.61: Comparison Between the 26-Week Expansions Generated Using the Accelerated C 1293 Procedures and the Different Calcined Clay
Replacement Levels
398
reactive in concrete made without lithium nitrate, exhibited innocuous expansions
also when 315, 495, and 900g LiNO3 was used to replace a volume of the water.
Table 12.27: Effect of Lithium Nitrate on ASR Using Accelerated C 1293 LiNO3 Weight (Volume)
Replacing Part of the Mixing Water
Aggregate ID
C 1293 One-Year Expansion
and Classification
Accelerated C 1293 13-Week Expansion and Classification
315g (3.5L)
495g (4.6L)
900g (10.0L)
A4-ID 0.379% Highly Reactive
0.396% Highly Reactive H.R. Innocuous Innocuous
A2-WY 0.107% Highly Reactive
0.083% Highly Reactive S.R. Innocuous Innocuous
C2-SD 0.053% Slowly Reactive
0.059% Slowly Reactive S.R. Innocuous Innocuous
E2-IA 0.025% Non-Reactive
0.028% Non-Reactive Innocuous Innocuous Innocuous
H.R. = Accelerated C 1293 13-week expansion > 0.070% S.R. = 0.040% < Accelerated C 1293 13-week expansion < 0.070%
Innocuous = Accelerated C 1293 13-week expansion < 0.040%
12.4.7 Effect of Air Entrainment Using Accelerated C 1293
In order to investigate the effect of air entrainment on the expansions due to ASR
using the accelerated C 1293, two ranges of entrained air were investigated, namely
between 2 and 4% and between 6 and 8%. Entrained air refers to total air content
reduced by the entrapped air content. The four aggregates, mentioned Table 12.1,
were used to prepare the different mixtures listed in Table 7.13. Results for these
procedures are illustrated in Table 12.28 and Figures 12.62 through 11.65. A
comparison between the 13-week expansions of the different air levels is shown in
Figure 12.66. As mentioned in Figure 12.1, a failure limit of 0.040% at 13 weeks was
used to evaluate the use of air entrainment.
399
Table 12.28: Accelerated C 1293 Expansions Using Air Entrainment Entrained Air Content Range
0% 2 – 4% 6 - 8% Time Aggregate A4-ID Expansions, %
1-week 0.058 0.061 0.098 2-week 0.141 0.109 0.152 4-week 0.324 0.225 0.256 8-week 0.353 0.433 0.341
13-week 0.396 0.500 0.389 18-week 0.424 0.522 0.457 26-week 0.440 0.541 0.475
Aggregate A2-WY Expansions, % 1-week 0.027 0.015 0.038 2-week 0.038 0.029 0.052 4-week 0.062 0.048 0.078 8-week 0.077 0.060 0.090
13-week 0.083 0.079 0.101 18-week 0.088 0.082 0.118 26-week 0.096 0.091 0.210
Aggregate C2-SD Expansions, % 1-week 0.014 0.015 0.013 2-week 0.016 0.019 0.020 4-week 0.029 0.031 0.029 8-week 0.050 0.049 0.041
13-week 0.059 0.058 0.050 18-week 0.063 0.066 0.059 26-week 0.071 0.075 0.063
Aggregate E2-IA Expansions, % 1-week 0.016 0.015 0.014 2-week 0.016 0.016 0.017 4-week 0.023 0.022 0.020 8-week 0.024 0.024 0.022
13-week 0.028 0.030 0.025 18-week 0.028 0.033 0.029 26-week 0.031 0.035 0.031
400
0.000
0.100
0.200
0.300
0.400
0.500
0.600
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14
Time, Weeks
13-W
eek
(3-M
onth
) Exp
ansi
on, %
ID-AE 0%ID-AE 2-4%ID-AE 6-8%
0.000
0.020
0.040
0.060
0.080
0.100
0.120
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14
Time, Weeks
13-W
eek
(3-M
onth
) Exp
ansi
on, %
WY-AE 0%WY-AE 2-4%WY-AE 6-8%
Figure 12.62: Effect of Air Entrainment on the Accelerated C 1293 Expansions of Aggregate A4-ID
Figure 12.63: Effect of Air Entrainment on the Accelerated C 1293 Expansions of Aggregate A2-WY
401
0.000
0.010
0.020
0.030
0.040
0.050
0.060
0.070
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14
Time, Weeks
13-W
eek
(3-M
onth
) Exp
ansi
on, %
SD-AE 0%SD-AE 2-4%SD-AE 6-8%
0.000
0.005
0.010
0.015
0.020
0.025
0.030
0.035
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14
Time, Weeks
13-W
eek
(3-M
onth
) Exp
ansi
on, %
IA-AE 0%IA-AE 4%IA-AE 6%
Figure 12.64: Effect of Air Entrainment on the Accelerated C 1293 Expansions of Aggregate C2-SD
Figure 12.65: Effect of Air Entrainment on the Accelerated C 1293 Expansions of Aggregate E2-IA
402
0.000
0.100
0.200
0.300
0.400
0.500
0.600
A4-ID A2-WY C2-SD A2-IAAggregate Investigated
13-W
eek
(3-m
onth
) Exp
ansi
on, %
0% Air2-4% Air6-8% Air
Observations related to these results are summarized in Table 12.25 where it can
be seen that using air entrainment was not effective in decreasing the 13-week
expansions to safe level for any of the reactive aggregates. It is worth noting that
these results are similar to the ones generated using the standard C 1293 and
summarized in Table 12.14. It is clear from Figure 12.66 that ranges of air
entrainment investigated did not result in any decrease in the 13-week expansions of
any of the reactive aggregates investigated. In the case of A4-ID, 2 to 4% entrained
air caused a drastic increase in the 13-week expansion and in the case of A2-WY, 6
to 8% entrained air also caused an increase in the 13-week expansion. Thus, it was
concluded that air entrainment is not effective in mitigating the alkali-silica reactivity
of aggregates in portland cement concrete.
Figure 12.66: Comparison Between the 13-Week Expansions Generated Using the Accelerated C 1293 Procedures and the Different Air
Entrainment Contents
403
Table 12.29: Effect of Air Entrainment on ASR Using Accelerated C 1293
Entrained Air Content Range
Aggregate ID
C 1293 One-Year Expansion
and Classification
Accelerated C 1293 13-Week Expansion and Classification 2 - 4% 6- 8%
A4-ID 0.379% Highly Reactive
0.396% Highly Reactive H.R. H.R.
A2-WY 0.107% Highly Reactive
0.083% Highly Reactive H.R. H.R.
C2-SD 0.053% Slowly Reactive
0.059% Slowly Reactive S.R. S.R.
E2-IA 0.025% Non-Reactive
0.028% Non-Reactive Innocuous Innocuous
H.R. = Accelerated C 1293 13-week expansion > 0.070% S.R. = 0.040% < Accelerated C 1293 13-week expansion < 0.070%
Innocuous = Accelerated C 1293 13-week expansion < 0.040%
12.4.8 Effect of Lowering the Cement Alkali Content Using Accelerated C 1293
In order to evaluate the effect of lowering the cement alkali content on ASR, the
accelerated C 1293 (at 600C) procedures were performed using cement Na2Oequiv.
contents of 1.25% (required by C 1293), 0.90%, and 0.60% Na2Oequiv.. The Na2Oequiv.
contents were achieved by using a cement with a total alkali content of 0.60% and
adding necessary amounts of NaOH to the mixing water. The highly reactive
aggregate, A6-NM, was added for this investigation in order to obtain more
confidence in the effects of Na2Oequiv. on the ASR expansions caused by such
aggregates. Mixture proportions, which were identical to the ones used for the C
1293 and accelerated C 1293 procedures, are listed in Table 7.12. Expansion results
are listed in Table 12.30 and Figures 12.67 through 12.70. An expansion limit of
0.040% at 13 weeks was used to differentiate between reactive and innocuous
expansions. A comparison between the 13-week expansions of concrete prisms made
with the different cement alkali contents is shown in Figure 12.71.
404
Table 12.30: Accelerated C 1293 Expansions Using Different Cement Na2Oequiv. Contents
Cement Na2Oequiv. Content 1.25% 0.90% 0.60% Time
Aggregate A6-NM Expansions, % 1-week 0.057 0.037 0.019 2-week 0.208 0.041 0.024 4-week 0.352 0.044 0.027 8-week 0.372 0.054 0.040
13-week 0.407 0.099 0.052 Aggregate A4-ID Expansions, %
1-week 0.058 0.043 0.025 2-week 0.141 0.046 0.024 4-week 0.324 0.045 0.024 8-week 0.353 0.064 0.040
13-week 0.396 0.084 0.052 Aggregate A2-WY Expansions, %
1-week 0.027 0.019 0.019 2-week 0.038 0.019 0.020 4-week 0.062 0.023 0.023 8-week 0.077 0.032 0.026
13-week 0.083 0.046 0.033 Aggregate C2-SD Expansions, %
1-week 0.014 0.014 0.012 2-week 0.016 0.020 0.014 4-week 0.029 0.024 0.015 8-week 0.050 0.028 0.013
13-week 0.059 0.029 0.014
405
0.000
0.050
0.100
0.150
0.200
0.250
0.300
0.350
0.400
0.450
0 2 4 6 8 10 12 14
Time, Weeks
13-W
eek
Exp
ansi
on, %
NM-1.25% Na2ONM-0.90% Na2ONM-0.60% Na2O
0.000
0.050
0.100
0.150
0.200
0.250
0.300
0.350
0.400
0.450
0 2 4 6 8 10 12 14
Time, Weeks
13-W
eek
Exp
ansi
on, %
ID-1.25% Na2OID-0.90% Na2OID-0.60% Na2O
Figure 12.67: Effect of Different Cement Alkali Contents on the Accelerated C 1293 Expansions of Aggregate A6-NM
Figure 12.68: Effect of Different Cement Alkali Contents on the Accelerated C 1293 Expansions of Aggregate A4-ID
406
0.000
0.010
0.020
0.030
0.040
0.050
0.060
0.070
0.080
0.090
0 2 4 6 8 10 12 14
Time, Weeks
13-W
eek
Exp
ansi
on, %
WY-1.25% Na2OWY-0.90% Na2OWY-0.60% Na2O
0.000
0.010
0.020
0.030
0.040
0.050
0.060
0.070
0 2 4 6 8 10 12 14
Time, Weeks
13-W
eek
Exp
ansi
on, %
SD-1.25% Na2OSD-0.90% Na2OSD-0.60% Na2O
Figure 12.69: Effect of Different Cement Alkali Contents on the Accelerated C 1293 Expansions of Aggregate A2-WY
Figure 12.70: Effect of Different Cement Alkali Contents on the Accelerated C 1293 Expansions of Aggregate C2-SD
407
0.0000.0400.0800.1200.1600.2000.2400.2800.3200.3600.4000.440
A6-NM A4-ID A2-WY C2-SD
Aggregate Investigated
13-W
eek
Exp
ansi
on, % 1.25% Na2O
0.90% Na2O0.60% Na2O
Observations related to these results are summarized in Table 12.31 where it can
be seen that at 1.25 Na2Oequiv., the alkali level required by the C 1293 procedures, all
aggregates investigated were reactive. At 0.90% Na2Oequiv., only the slowly reactive
aggregate, C2-SD, exhibited innocuous expansions. At 0.60% the slowly reactive
aggregate, C2-SD, and the moderately reactive aggregate, A2-WY, exhibited
innocuous expansions. At all three levels, the highly reactive aggregates, A6-NM and
A4-ID, showed reactive expansions. From Figures 12.67 through 12.71, it can be
noted that as the Na2Oequiv. content decreased the expansion decreased with the
biggest decrease noted for the highly reactive aggregates, A6-NM and A4-ID. Even
though these two aggregates exhibited reactive expansion at 0.60% Na2Oequiv., their
13-week expansions were drastically decreased. Thus, using a cement alkali content
as low as 0.60% resulted in the slowly and moderately reactive aggregate to be
innocuous; however, the highly reactive aggregates were still showing reactive
expansions.
Figure 12.71: Comparison Between the 13-Week Accelerated C 1293 Expansions of Concrete Prisms Made with Different Na2Oequiv. Contents
408
Table 12.31: Effect of Na2Oequiv. Content on ASR Using Accelerated C 1293
Na2Oequiv. Cement Content
Aggregate ID
C 1293 One-Year Expansion
and Classification
Accelerated C 1293 13-Week Expansion and Classification 1.25% 0.90% 0.60%
A6-NM 0.411% Highly Reactive
0.407% Highly Reactive H.R. H.R. S.R.
A4-ID 0.379% Highly Reactive
0.396% Highly Reactive H.R. H.R. S.R.
A2-WY 0.107% Highly Reactive
0.083% Highly Reactive H.R. S.R. Innocuous
C2-SD 0.053% Slowly Reactive
0.059% Slowly Reactive S.R. Innocuous Innocuous
H.R. = Accelerated C 1293 13-week expansion > 0.070% S.R. = 0.040% < Accelerated C 1293 13-week expansion < 0.070%
Innocuous = Accelerated C 1293 13-week expansion < 0.040%
12.4.9 Comparison Between the Effectiveness of the Different Mitigation
Alternatives
With the exception of air entrainment, expansions caused by ASR decreased as
the mitigating alternative dosage increased in the mixture. This was true for the
reactive aggregates A4-ID, A2-WY, and C 2-SD combined with Class C fly ash,
Class F fly ash, silica fume, granulated slag, calcined clay, and lithium nitrate. Even
though not all the dosages decreased the expansions to safe level, they did cause a
decrease in the expansions. Lowering the total alkali content of the cement resulted
in decreasing the expansions of investigated aggregates. A comparison between the
effectiveness of the different dosages investigated for all four aggregates is illustrated
in Figures 12.72 through 12.75.
409
Highly Reactive Aggregate A4-ID
0.000 0.070 0.140 0.210 0.280 0.350 0.420 0.490
No Mitigation25% Slag
20% Class C Fly Ash315g LiNO3
5% Silica Fume15% Class F Fly Ash
27.5% Class C Fly Ash25% Class F Fly Ash
10% Silica Fume35% Class C Fly Ash
17% Calcined Clay495g LiNO3900g LiNO3
55% Slag70%Slag
25% Calcined ClayM
itiga
tion
Alte
rnat
ive
26-Week Expansion, %
Best
Worst
Highly Reactive Aggregate A2-WY
0.000 0.040 0.080 0.120
No Mitigation20% Class C Fly Ash
27.5% Class C Fly Ash25% Slag
15% Class F Fly Ash35% Class C Fly Ash
5% Silica Fume315g LiNO3
17% Calcined Clay10% Silica Fume
70%Slag495g LiNO3
25% Class F Fly Ash55% Slag
25% Calcined Clay900g LiNO3
Miti
gatio
n A
ltern
ativ
e
26-Week Expansion, %
Best
Worst
Figure 12.72: Comparison Between the Different Mitigation Alternatives Used With Aggregate A4-ID and the Accelerated C 1293
Figure 12.73: Comparison Between the Different Mitigation Alternatives Used With Aggregate A2-WY and the Accelerated C 1293
410
Slowly Reactive Aggregate C2-SD
0.000 0.010 0.020 0.030 0.040 0.050 0.060 0.070 0.080
No Mitigation20% Class C Fly Ash
25% Slag15% Class F Fly Ash
5% Silica Fume27.5% Class C Fly
315g LiNO3495g LiNO3
70%Slag10% Silica Fume
35% Class C Fly Ash900g LiNO3
55% Slag17% Calcined Clay
25% Class F Fly Ash25% Calcined Clay
Miti
gatio
n A
ltern
ativ
e
26-Week Expansion, %
Best
Worst
Innocuous Aggregate E2-IA
0.000 0.010 0.020 0.030 0.040
5% Silica Fume25% Slag
315g LiNO320% Class C Fly Ash
No Mitigation15% Class F Fly Ash
27.5% Class C Fly Ash495g LiNO3
10% Silica Fume35% Class C Fly Ash
17% Calcined Clay25% Class F Fly Ash
900g LiNO355% Slag70%Slag
25% Calcined Clay
Miti
gatio
n A
ltern
ativ
e
26-Week Expansion, %
Best
Worst
Figure 12.74: Comparison Between the Different Mitigation Alternatives Used With Aggregate C2-SD and the Accelerated C 1293
Figure 12.75: Comparison Between the Different Mitigation Alternatives Used With Aggregate E2-IA and the Accelerated C 1293
411
12.4.10 Summary of the Evaluation of the Mitigation Alternatives Using the
Accelerated Concrete Prism Test
The accelerated C 1293, performed at 600C, was used to evaluate the effectiveness
of the mitigation alternatives using a 13-week expansion limit of 0.040% for lithium
nitrate, air entrainment, and low Na2Oequiv. content, and a 26-week expansion limit of
0.040% for Class C fly ash, Class F fly ash, silica fume, granulated slag, and calcined
clay. Table 12.32 includes a summary of this evaluation. As can be seen from this
table, the only alternatives that were effective with all aggregates investigated are the
use of a minimum of 55% granulated slag and a minimum of 25% calcined clay.
Alternatives that were effective with the slowly reactive aggregates C2-SD are the
use of a minimum of 35% Class C fly ash, 15% Class F fly ash, 10% silica fume,
55% slag, 17% calcined clay by weight of cement, the use of a minimum of 495g of
LiNO3 (4.6L per 1 kg of Na2Oeqiv.), and the use of cement with a maximum Na2Oequiv.
content of 0.90%. Alternatives that were effective with the moderately reactive
aggregate A2-WY are the use of a minimum of 25% Class F fly ash, 55% slag, 25%
calcined clay by weight of cement, the use of a minimum of 495g of LiNO3 (4.6L per
1 kg of Na2Oeqiv.), and the use of cement with a maximum Na2Oequiv. content of
0.60%. Alternatives that were effective with the highly reactive aggregate A4-ID are
the use of a minimum of 55% slag and 25% calcined clay by weight of cement, and
the use of a minimum of 495g of LiNO3 (4.6L per 1 kg of Na2Oeqiv.). It seems that
different levels of aggregate reactivity required different mitigation alternatives. It
should be noted that aggregate E2-IA, which was classified innocuous when tested
according to C 1293, exhibited innocuous expansions when tested using all the
mitigation alternatives.
412
Table 12.32: Effectiveness of the Mitigation Alternatives Using the Accelerated C 1293 Criteria
Aggregate ID, 13-Week Expansion, C 1293 Reactivity Classification
Cementitious Material
Replacement Level By Weight of Cement
A4-ID 0.396% Highly
Reactive
A2-WY 0.083% Highly
Reactive
C2-SD 0.059% Slowly
Reactive
E2-IA 0.028%
Innocuous
20% H.R. H.R. S.R. Innocuous
27.5% H.R. H.R. S.R. InnocuousClass C Fly Asha
35% S.R. S.R. Innocuous Innocuous
15% H.R. S.R. S.R. InnocuousClass F Fly Asha 25% S.R. Innocuous Innocuous Innocuous
5% H.R. H.R. S.R. InnocuousSilica Fumea 10% S.R. S.R. Innocuous Innocuous
25% H.R. S.R. S.R. Innocuous
55% Innocuous Innocuous Innocuous InnocuousGranulated Slaga
70% Innocuous Innocuous Innocuous Innocuous
17% S.R. S.R. Innocuous InnocuousCalcined Claya 25% Innocuous Innocuous Innocuous Innocuous
Aggregate ID, 13-Week Expansion, C 1293 Reactivity Classification
Chemical Material Dosage
A4-ID 0.396% Highly
Reactive
A2-WY 0.083% Highly
Reactive
C2-SD 0.059% Slowly
Reactive
E2-IA 0.028%
Innocuous
Lithium Nitrateb 315 g H.R. S.R. S.R. Innocuous
495 g Innocuous Innocuous Innocuous Innocuous
900 g Innocuous Innocuous Innocuous Innocuous
Entrained Airb 2 - 4% H.R. H.R. S.R. Innocuous
6 - 8% H.R. H.R. S.R. Innocuous
413
Table 12.32 (Cont’d): Effectiveness of the Mitigation Alternatives Using the Accelerated C 1293 Criteria
Cementitious Material
Na2Oequiv. Content
A6-NM 0.407% Highly
Reactive
A4-ID 0.396% Highly
Reactive
A2-WY 0.083% Highly
Reactive
C2-SD 0.059% Slowly
Reactive 0.90% H.R. H.R. S.R. Innocuous
Cementb
0.60% S.R. S.R. Innocuous InnocuousaH.R. = Accelerated C 1293 26-week expansion > 0.070% aS.R. = 0.040% < Accelerated C 1293 26-week expansion < 0.070%
aInnocuous = Accelerated C 1293 26-week expansion < 0.040%
bH.R. = Accelerated C 1293 13-week expansion > 0.070% bS.R. = 0.040% < Accelerated C 1293 13-week expansion < 0.070%
bInnocuous = Accelerated C 1293 13-week expansion < 0.040%
12.5 INVESTIGATION OF MITIGATION ALTERNATIVES USING
ACCELERATED C 1293 RESULTS AND CEMENTS WITH
DIFFERENT Na2Oequiv. CONTENTS
Earlier sections of this chapter were devoted to investigating the effects of the
mitigation alternatives using the procedures of C 1293 (at 380C) or the accelerated C
1293 (at 600C), both of which call for increasing the cement alkali content to 1.25%
Na2Oequiv.. It was found that few alternatives were able to decrease the expansions of
highly reactive aggregates to safe levels. An attempt was made to evaluate the
effectiveness of these alternatives in decreasing the expansions of the highly reactive
aggregate, A6-NM, using cement with an alkali content of 0.80% Na2Oequiv.. The
purpose of this investigation was as follows:
1. Evaluate the effect of coupling the use of a mitigation alternative with a low
alkali cement on the reactivity of highly reactive aggregates and
2. Confirm the conclusions obtained using ASTM C 1260 (the mortar bar test).
According to the C 1260 results (Chapter 11, Table 11.30), at a cement alkali
content lower than 0.80% Na2Oequiv., effective alternatives include the use of a
414
minimum of 17% calcined clay, 50% granulated slag, 20% Class F fly ash, 10%
silica fume, 35% Class C fly ash, and 3.5 L LiNO3 per 1 kg of Na2Oequiv..
The accelerated C 1293 procedures were used to evaluate the effectiveness of the
mitigation alternative on the ASR expansions of aggregate A6-NM using a cement
with a total alkali content of 0.80%. Expansion limits were as specified earlier.
Expansion results for these procedures are listed in Table 12.33 and Figures 12.76
through 12.78.
Table 12.33: Accelerated C 1293 Expansions of Aggregate A6-NM Using Different Mitigation Alternatives and 0.80% Na2Oequiv. Content Cement
Accelerated C 1293 Expansion For Aggregate A6-NM % Mitigation
Alternative
Replacement Level by
Weight of Cement 1-week 2-week 4-week 8-week 13-week 18-week 26-week
25% 0.002 0.009 0.015 0.021 0.036 0.049 0.063 Class C Fly Ash 35% 0.001 0.005 0.010 0.015 0.021 0.028 0.032
15% 0.006 0.011 0.019 0.024 0.033 0.049 0.056 Class F Fly Ash 20% 0.000 0.005 0.011 0.020 0.024 0.029 0.031
5% 0.009 0.019 0.026 0.037 0.049 0.060 0.082 Silica Fume 10% 0.001 0.006 0.010 0.015 0.020 0.029 0.034
25% 0.050 0.098 0.121 0.185 0.200 0.210 0.231 Granulated Slag 50% 0.001 0.003 0.008 0.015 0.020 0.027 0.031
17% 0.000 0.002 0.005 0.010 0.019 0.021 0.030 Calcined Clay 25% 0.000 0.001 0.004 0.010 0.017 0.020 0.025
315g 0.001 0.008 0.015 0.021 0.028 0.033 0.044 Lithium Nitrate 495g 0.000 0.002 0.009 0.018 0.022 0.025 0.029
2-4% 0.070 0.119 0.153 0.185 0.201 0.220 0.231 Entrained Air 6-8% 0.050 0.099 0.120 0.168 0.194 0.210 0.219
415
0.000
0.050
0.100
0.150
0.200
0.250
0 2 4 6 8 10 121416 1820 2224 2628
Time, Weeks
Exp
ansi
on, %
NM-SF 5%NM-SF 10%NM-SL 25%NM-SL 50%NM-CC 17%NM-CC 25%
0.000
0.010
0.020
0.030
0.040
0.050
0.060
0.070
0 2 4 6 8 101214161820 22242628
Time, Weeks
Exp
ansi
on, % NM-FAC 25%
NM-FAC 35%NM-FAF 15%NM-FAF 20%
Figure 12.76: Effect of Silica Fume, Granulated Slag, and Calcined Clay on the Accelerated C 1293 Expansions of Aggregate A6-NM Using a 0.80%
Na2Oequiv. Cement
Figure 12.77: Effect of Class C Fly Ash and Class F Fly Ash on the Accelerated C 1293 Expansions of Aggregate A6-NM Using a 0.80%
Na2Oequiv. Cement
416
0.000
0.050
0.100
0.150
0.200
0.250
0 2 4 6 8 10 12 14 16 18 20 22 24 26 28
Time, Weeks
Exp
ansi
on, % NM-LI 315 g
NM-LI 495 gNM-AE 4%NM-AE 6%
Findings from these results are summarized in Table 12.34, where it can be seen
that using a maximum of 0.80% Na2Oequiv. cement with the highly reactive aggregate
A6-NM allowed the use of more alternatives for mitigating excessive ASR
expansions. Alternatives that resulted in innocuous expansions for aggregate A6-NM
and 0.80% Na2Oequiv. cement included the use of a minimum of a 35% Class C fly
ash, 20% Class F fly ash, 10% silica fume, 50% granulated slag, 17% calcined clay,
and 495g of LiNO3 (4.6L of LiNO3 per 1 kg of Na2Oequiv. in mixture). These results
are comparable to the ones obtained using ASTM C 1260 (the mortar-bar test at two
weeks). Thus, using a 0.80% Na2Oequiv. cement allowed more flexibility with
alternatives and resulted in more efficient mitigation of the alkali-silica reactivity of
the highly reactive aggregate A6-NM.
Figure 12.78: Effect of Lithium Nitrate and Air Entrainment on the Accelerated C 1293 Expansions of Aggregate A6-NM Using a 0.80%
Na2Oequiv. Cement
417
Table 12.34: Effectiveness of Different Mitigation Alternatives Using The Accelerated C 1293 with Aggregate A6-NM and 0.80% Na2Oequiv. Cement
Mitigation Alternative
Replacement Level by
Weight of Cement
Aggregate A6-NM 13-Week C 1293 (600C) Expansion of
0.407% Highly Reactive
25% S.R. Class C Fly Asha 35% Innocuous
15% S.R. Class F Fly Asha 20% Innocuous
5% H.R. Silica Fumea 10% Innocuous
25% H.R. Granulated Slaga 50% Innocuous
17% Innocuous Calcined Claya 25% Innocuous
315g S.R. Lithium Nitrateb 495g Innocuous
2-4% H.R. Entrained Airb 6-8% H.R.
aH.R. = Accelerated C 1293 26-week expansion > 0.070% aS.R. = 0.040% < Accelerated C 1293 26-week expansion < 0.070%
aInnocuous = Accelerated C 1293 26-week expansion < 0.040%
bH.R. = Accelerated C 1293 13-week expansion > 0.070% bS.R. = 0.040% < Accelerated C 1293 13-week expansion < 0.070%
bInnocuous = Accelerated C 1293 13-week expansion < 0.040%
418
12.6 SUMMARY AND SPECIFICATIONS
Tables 12.35 and 12.36 list alternatives that were effective in mitigating the alkali
silica reactivity of aggregates investigated. These results were generated using the
accelerated C 1293 procedures performed at 600C.
Table 12.35: Effective ASR Mitigation Alternatives When Evaluating Aggregates Using Accelerated C 1293 at 600C
Aggregate ID, 13-Week Accelerated C 1293 Expansion, Classification A4-ID
0.396% Highly Reactive
A2-WY 0.083%
Highly Reactive
C2-SD 0.059%
Slowly Reactive
E2-IA 0.028%
Innocuous Cementitious Material Minimum Replacement Level by Weight of Cement Calcined
Clay 25% 25% 17% 0%
Granulated Slag 55% 55% 55% 0%
Class F Fly Ash > 25% 25% 25% 0%
Silica Fume 10% 0%
Class C Fly Ash > 35% > 35% 35% 0%
Minimum Cement Na2Oequiv. Content Cement
0.60% 0.90% Not Applicable
Chemical Admixture Minimum LiNO3 Volume (weight) per 1 kg of Na2Oequiv.
Lithium Nitrate 4.6 L (495 kg) 4.6 L (495 kg) 4.6 L (495 kg) 0g
Shaded Areas = Alternative could not be used
419
Table 12.36: Effective ASR Mitigation Alternatives for Highly Reactive Aggregate A6-NM (Accelerated C 1293 13-week of 0.407%) Evaluated Using
Accelerated C 1293 (600C) with 0.80% Na2Oequiv. Cement
Cementitious Material Minimum Replacement Levels by Weight of Cement
Calcined Clay 17%
Granulated Slag 50%
Class F Fly Ash 25%
Silica Fume 10%
Class C Fly Ash 35%
Chemical Material Minimum LiNO3 Volume (Weight) per 1 kg of Na2Oequiv.
Lithium Nitrate 4.6 L (495 kg)
Air Entrainment
Shaded Areas = Alternative could not be used
420
CHAPTER THIRTEEN
COMPARISON BETWEEN C 1260, C 1293, PETROGRAPHIC ANALYSIS, AND FIELD INVESTIGATION RESULTS
13.1 INTRODUCTION
This chapter includes a comparison between the results generated using the C
1260 (mortar-bar test) and the C 1293 (concrete-prism test) testing procedures. The
first part of this chapter is dedicated to comparing testing results for assessing the
potential reactivity of aggregates. The second part is concerned with comparing the
results of evaluating mitigation alternatives using both testing procedures.
Discussions and conclusions are stated when appropriate.
13.2 ASTM C 1260, ASTM C 1293, PETROGRAPHIC EXAMINATION, AND
FIELD PERFORMANCE
Comparing the results of C 1260 and C 1293 consisted of comparing the 14-day
expansions generated using C 1260 versus the 52-week expansions generated using
C 1293. A list of these expansions is included in Table 13.1 and a comparison is
shown in Figure 13.1. The following observations were noted:
1. Aggregates with 14-day expansions below 0.10% correlated well with 52-week
expansions below 0.040%. These aggregates had good field performance and no
reactive materials were found after a petrographic examination. Thus, innocuous
aggregates were correctly identified using C 1260 and C 1293.
2. Aggregates with 14-day expansions between 0.10% and 0.20% correlated well
with 52-week expansions between 0.040% and 0.070%. Slowly reactive
aggregates showing 14-day expansions between 0.10% and 0.20% were also
identified as slowly reactive using C 1293 with 52-week expansions between
0.040% and 0.070%. This correlated well with the field performance of these
aggregates. However, a petrographic analysis failed to detect the reactive
materials in these aggregates. Thus, for slowly reactive aggregates, C 1260 and C
421
1293 correlated well with field performance but petrographic examination was
not effective.
Table 13.1: C 1260 14-Day Expansions and C 1293 52-Week Expansions
Aggregate ID
Petrographic Analysisa
Reported Field
Performance
C 1260 14-Day
%
C 1293 52-Weeks
%
A1-WY Reactive Materials Reactive 0.24
H.R 0.073 H.R.
A2-WY Reactive Materials Reactive 0.29
H.R. 0.107 H.R.
A4-ID Reactive Materials Reactive 0.79
H.R. 0.305 H.R.
A6-NM Reactive Materials Reactive 0.91
H.R. 0.308 H.R.
A7-NC Reactive Materials Reactive 0.31
H.R. 0.085 H.R.
A9-NE Reactive Materials Reactive 0.28
H.R. 0.051 S.R.
A10-PA Reactive Materials Reactive 0.26
H.R. 0.043 S.R.
B2-MD No Reactive Materials Reactive 0.12
S.R. 0.046 S.R.
B4-VA No Reactive Materials No Record 0.15
S.R. 0.041 S.R.
C2-SD No Reactive Materials Reactive 0.17
S.R. 0.053 S.R.
D2-IL No Reactive Materials
Good with high alkali cement
0.02 Innocuous
0.022 Innocuous
E4-NV Reactive Materials
Good with mitigation
0.25 H.R.
0.060 S.R.
E6-IN No Reactive Materials
Good with high alkali cement
0.25 H.R.
0.022 Innocuous
E2-IA No Reactive Materials
Good with high alkali cement
0.42 H.R.
0.025 Innocuous
E8-NM Reactive Materials
Good with mitigation
0.36 H.R.
0.064 S.R.
H.R. = Highly Reactive; S.R. = Slowly Reactive Shaded areas are instances where C 1260 overestimated the reactivity as compared to ASTM C 1293
a Petrographic analysis obtained through reported provided by aggregate producers and confirmed by a petrographer, Mr. Tom Patti (Appendix D).
422
0.00
0.04
0.08
0.12
0.16
0.20
0.24
0.28
0.32
0.36
0.00 0.10 0.20 0.30 0.40 0.50 0.60 0.70 0.80 0.90 1.00
14-Day C 1260 Expansions, %
52-W
eek
C 1
293
Exp
ansi
ons,
%
E2-IAE6-IN
C 1260 Failure Criteria
C 1293 Failure Criteria
Figure 13.1: C 1260 Results vs. C 1293 Results Note on Figure 13.1: C 1293 one-year expansions plotted on the y-axis and C1260 14-day expansions plotted on the x-axis. The figure shows how the C1260 expansions are overestimating the reactivity of aggregates. Aggregatesclassified as slowly reactive using C 1293 are shown as highly reactive by theC 1260 criteria. In addition, E6-IN and E2-IA that are innocuous by C 1293are found highly reactive with C 1260.
423
3. Fourteen-day expansions higher than 0.20% correlated well with 52-week
expansions higher than 0.070%. Moderately and highly reactive aggregates were
correctly identified using both C 1260 (0.20% limit) and C 1293 (0.070% limit).
These aggregates were reactive in field applications and contained reactive
materials when examined petrographically.
4. Potentially reactive aggregates showed 14-day expansions higher than 0.10% (C
1260) and 52-week expansions (C 1293) higher than 0.040%.
5. A9-NE did not satisfy the above observations. A9-NE is a mixture of coarse and
fine aggregate that has shown a 14-day expansion of 0.280% and a 52-week
expansion of 0.051%. Thus, using C 1260, the aggregate was classified as highly
reactive but using C 1293 it was classified as slowly reactive. This behavior was
expected since for C 1293 the aggregate was used “as is” including the fine and
coarse portions. The coarse portion of the aggregate consisted of an innocuous
limestone which when combined with the fine portion will result in an aggregate
with lower reactivity than the fine portion. The C 1260 procedures call for
separating the aggregate into several sieve sizes and using a percentage of each
sieve. As a result, only the fine portion of the mixed aggregate was tested with C
1260, which explains why the C 1260 reactivity was higher than the C 1293
reactivity. Thus, C 1260 cannot be accurately used to predict the reactivity of
mixed aggregates. This should be accomplished using C 1293.
6. E2-IA and E6-IN also presented discrepancies from the above observations as
seen in Figure 13.1. Both aggregates were reported as potentially reactive when
tested using C 1260 (0.42% and 0.25% respectively) but both passed C 1293
(0.025% and 0.022% respectively). As noted in Table 13.1, these two aggregates
have been successfully used in field applications with high alkali cements (at
least as high as 0.9%). In addition, petrographic analysis indicated that the two
aggregates do not contain reactive materials. The C 1293 results correlated best
with the field performance and the petrographic analysis results and was
424
considered to be more realistic. It was mentioned earlier that this problem was
also noted by the NAA results where they had 10 aggregates that passed C 1293
but failed C 1260. Thus, it can be concluded that the C 1260 procedures are too
severe for some aggregates that pass C 1293.
7. ASTM C 1260 was also too severe for A10-PA, E4-NV, and E8-NM resulting in
an over estimation of the aggregates’ reactivity. A10-PA, E4-NV, and E8-NM
exhibited 14-day expansions of 0.26, 0.25, and 0.36%, respectively, indicating
that the aggregates should be characterized as highly reactive. However, these
aggregates exhibited one-year expansions of 0.043, 0.060, and 0.064%,
respectively, indicating that the aggregates should be characterized as slowly
reactive. Thus, C 1260 resulted in a more conservative estimate of the reactivity.
Nevertheless, both tests indicated that the three aggregates were reactive, which
corresponds to the field performance and petrographic analysis record.
8. From the above comments, it can be concluded that C 1260 should be used only
as a screening method in combination with C 1293. C 1260 should not be solely
used to determine the potential reactivity of aggregates but should be supported
by C 1293. On the other hand, C 1293 could be solely used to predict the
potential reactivity of aggregates.
9. Petrographic analysis failed to detect the reactive materials present in the slowly
reactive aggregates investigated (detailed reports in Appendix D). Petrography
should not be used with this type of aggregate.
10. A summary of an appropriate test combination for determining the potential
alkali-silica reactivity of aggregate is shown in Figure 13.2.
425
Potential Alkali-Silica Reactivity Characterization of Aggregates
ASTM C 1260 Mortar-Bar Test
Results required within 2 weeks No Time Constraint
14-day expansion > 0.20%
Innocuous Yes
No
0.10% < 14-day
expansion < 0.20%
Slowly Reactive
Yes
14-day expansion < 0.10%
Highly Reactive
Yes
No
ASTM C 1293 Concrete Prism Test
380C 600C
If ti
me
is a
vaila
ble
verif
y us
ing
AST
M C
129
3 Innocuous
One-year expansion< 0.040%
13-week expansion< 0.040%
Yes
No No
Slowly Reactive
0.040% < one-year
expansion< 0.070%
0.040% < 13-week
expansion< 0.070%
Yes
No No
Highly Reactive
One-year expansion> 0.070%
13-Week Expansion> 0.070%
Yes
Figure 13.2a: Characterization of Aggregate Potential Alkali-Silica Reactivity
426
Figure 13.2b: Summary Characterization of Aggregate Potential Alkali-Silica Reactivity
Potential Alkali-Silica Reactivity Characterization of Aggregates
ASTM C 1260 Mortar-Bar Test
Signs of Reactivity?
ASTM C 1293 Concrete-Prism Test
Signs of Reactivity?
Potentially Reactive AggregateSpecial Requirements
Innocuous Aggregate No Special Requirement
If time available
Yes No
Yes
Yes No
427
13.3 C 1260 MITIGATION ALTERNATIVES vs. C 1293 MITIGATION
ALTERNATIVES
This comparison consisted of evaluating mitigation alternatives using both C 1260
and C 1293. Expansion limits used to evaluate the alternatives using both testing
procedures are listed in Table 13.2.
Table 13.2: Expansion Limits Used to Evaluate Effectiveness of Mitigation Alternatives
ASTM C 1260 ASTM C 1293
at 380C Accelerated C 1293 at 600C
Specified Period of Evaluation Mitigation Alternative 14-Days 2-Years 26-Weeks
Class C Fly Ash 0.10% 0.040% 0.040%
Class F Fly Ash 0.10% 0.040% 0.040%
Silica Fume 0.10% 0.040% 0.040%
Granulated Slag 0.10% 0.040% 0.040%
Calcined Clay 0.10% 0.040% 0.040%
Specified Period of Evaluation 14-Days One-Year 13-Week
Lithium Nitrate 0.10% 0.040% 0.040%
Air Entrainment 0.10% 0.040% 0.040%
Cement Na2Oequiv.
0.10% 0.040% 0.040%
Shaded area indicate results that are not available as yet
It was mentioned in Chapter 12 that the 2-years of ASTM C 1293 are not
available and that the accelerated C 1293 performed at 600C exhibited remarkable
correlation with the standard C 1293. A comparison between the results generated
using both test indicated that the accelerated procedures could be used to evaluate
mitigation alternatives. Comparison between the accelerated C 1293 and ASTM C
1260 (The mortar bar test) is presented in this section.
428
Table 13.3: Effectiveness of Mitigation Alternatives with Aggregate A4-ID Evaluated Using C 1260 and Accelerated C 1293
Aggregate A4-ID
Cementitious Material
Replacement Level by Weight of
Cement
ASTM C 1260a
14-day expansion of
0.79% Highly Reactive
C 1293 at 600Cb,c
13-week expansion of
0.396% Highly Reactive
20% H.R. H.R. 27.5% H.R. H.R. Class C
Fly Ash 35% S.R. S.R. 15% H.R. H.R. Class F
Fly Ash 25% S.R. S.R. 5% H.R. H.R. Silica
Fume 10% S.R. S.R. 55% Innocuous Innocuous Granulated
Slag 70% Innocuous Innocuous 17% S.R. S.R. Calcined
Clay 25% Innocuous Innocuous
Chemical Material
Dosage Volume per 1 kg of
Na2Oequiv.
3.5 L H.R. H.R. 4.6 L H.R. Innocuous Lithium Nitrate
10.0 L S.R. Innocuous 2-4% H.R. H.R. Entrained
Air 6-8% H.R. H.R. aH.R. = C 1260 14-day expansion > 0.20% aS.R. = 0.10% < C 1260 14-day expansion < 0.20%
aInnocuous = C 1260 14-day expansion < 0.10%
bH.R. = Accelerated C 1293 26-week expansion > 0.070% bS.R. = 0.040% < Accelerated C 1293 26-week expansion < 0.070%
bInnocuous = Accelerated C 1293 26-week expansion < 0.040%
cH.R. = Accelerated C 1293 13-week expansion > 0.070% cS.R. = 0.040% < Accelerated C 1293 13-week expansion < 0.070%
cInnocuous = Accelerated C 1293 13-week expansion < 0.040%
429
Table 13.4: Effectiveness of Mitigation Alternatives with Aggregate A2-WY Evaluated Using C 1260 and Accelerated C 1293
Aggregate A2-WY
Cementitious Material
Replacement Level by Weight of
Cement
ASTM C 1260a
14-Day Expansion of
0.29% Highly Reactive
C 1293 at 600Cb,c
13-Week Expansion of
0.083% Highly Reactive
20% H.R. H.R. 27.5% H.R. H.R. Class C
Fly Ash 35% S.R. S.R. 15% S.R. S.R. Class F
Fly Ash 25% Innocuous Innocuous 5% H.R. H.R. Silica
Fume 10% S.R. S.R. 55% Innocuous Innocuous Granulated
Slag 70% Innocuous Innocuous 17% S.R. S.R. Calcined
Clay 25% Innocuous Innocuous
Chemical Material
Dosage Volume per 1 kg of
Na2Oequiv.
3.5 L Innocuous S.R. 4.6 L Innocuous Innocuous Lithium Nitrate
10.0 L Innocuous Innocuous 2-4% S.R. H.R. Entrained
Air 6-8% S.R. H.R. aH.R. = C 1260 14-day expansion > 0.20% aS.R. = 0.10% < C 1260 14-day expansion < 0.20%
aInnocuous = C 1260 14-day expansion < 0.10%
bH.R. = Accelerated C 1293 26-week expansion > 0.070% bS.R. = 0.040% < Accelerated C 1293 26-week expansion < 0.070%
bInnocuous = Accelerated C 1293 26-week expansion < 0.040%
cH.R. = Accelerated C 1293 13-week expansion > 0.070% cS.R. = 0.040% < Accelerated C 1293 13-week expansion < 0.070%
cInnocuous = Accelerated C 1293 13-week expansion < 0.040%
430
Table 13.5: Effectiveness of Mitigation Alternatives with Aggregate C2-SD Evaluated Using C 1260 and Accelerated C 1293
Aggregate A2-WY
Cementitious Material
Replacement Level by Weight of
Cement
ASTM C 1260a
14-Day Expansion of
0.17% Slowly Reactive
C 1293 at 600Cb,c
13-Week Expansion of
0.059% Slowly Reactive
20% S.R. S.R. 27.5% S.R. S.R. Class C
Fly Ash 35% Innocuous Innocuous 15% S.R. S.R. Class F
Fly Ash 25% Innocuous Innocuous 5% S.R. S.R. Silica
Fume 10% Innocuous Innocuous 55% Innocuous Innocuous Granulated
Slag 70% Innocuous Innocuous 17% Innocuous Innocuous Calcined
Clay 25% Innocuous Innocuous
Chemical Material
Dosage Volume per 1 kg of
Na2Oequiv.
3.5 L S.R. S.R. 4.6 L Innocuous Innocuous Lithium Nitrate
10.0 L Innocuous Innocuous 2-4% S.R. S.R. Entrained
Air 6-8% S.R. S.R. aH.R. = C 1260 14-day expansion > 0.20% aS.R. = 0.10% < C 1260 14-day expansion < 0.20%
aInnocuous = C 1260 14-day expansion < 0.10%
bH.R. = Accelerated C 1293 26-week expansion > 0.070% bS.R. = 0.040% < Accelerated C 1293 26-week expansion < 0.070%
bInnocuous = Accelerated C 1293 26-week expansion < 0.040%
cH.R. = Accelerated C 1293 13-week expansion > 0.070% cS.R. = 0.040% < Accelerated C 1293 13-week expansion < 0.070%
cInnocuous = Accelerated C 1293 13-week expansion < 0.040%
431
Results listed in Table 13.3 through 13.5 are illustrated in Figures 13.3 and 13.4.
Figure 13.3 shows how the effectiveness of Class C fly ash, Class F fly ash, silica
fume, granulated slag, and calcined clay is evaluated using both concrete and mortar
bar tests. Figure 13.4 shows the same thing but for the use of lithium nitrate and air
entrainment.
0.00
0.10
0.20
0.30
0.40
0.50
0.60
0.000 0.040 0.080 0.120 0.160
26-Week Accelerated C 1293 Expansion, %
14-D
ya A
STM
C 1
260
Exp
ansi
on, %
Accelerated C 1293 Failure Criterion
ASTM C 1260 Failure Criterion
Figure 13.3a: Different Replacement Levels of Class C Fly Ash, Class F Fly Ash, Silica Fume, Slag, and Calcined Clay, Evaluated Using ASTM C
1260 and the Accelerated C 1293 Procedures (600C)
432
y = 4.2424x - 0.0769R2 = 0.7441
0.00
0.10
0.20
0.30
0.40
0.50
0.60
0.000 0.040 0.080 0.120 0.160
26-Week Accelerated C 1293 Expansion, %
14-D
ya A
STM
C 1
260
Exp
ansi
on, %
0.00
0.10
0.20
0.30
0.40
0.50
0.60
0.000 0.080 0.160 0.240 0.320 0.400 0.480 0.560
13-Week Accelerated C 1293 Expansion, %
14-D
ya A
STM
C 1
260
Exp
ansi
on, %
Figure 13.3b: Trend line Illustrating the Relation Between ASTM C 1260 and Accelerated C 1293 in Evaluating the Use of Class C Fly Ash, Class F
Fly Ash, Silica Fume, Slag, and Calcined Clay
Figure 13.4: Different Dosages of Air Entrainment and Lithium Nitrate, Evaluated Using ASTM C 1260 and the Accelerated C 1293 Procedures
(600C)
433
Results indicate that, with very exceptions, ASTM C 1260 and the accelerated C
1293 are producing similar results. As indicated in Table 13.3 through 13.5 using a
limit of 0.10% at 14 days for ASTM C 1260 and a limit of 0.040% at 26 weeks for
the accelerated C 1293 it was possible to generate identical results for aggregates A4-
ID, A2-WY, and C2-SD when the use of Class C fly ash, Class F fly ash, silica fume,
granulated slag, and calcined clay was being evaluated.
It was suggested in Chapter 11 that ASTM C 1260 could not be used to evaluate
the use of lithium nitrate due to the leaching of the material from the mortar bars.
This fact is further reinforced by the conflicting results between ASTM C 1260 and
the accelerated C 1293 as indicated in Tables 13.3 and 13.4 for the highly reactive
aggregates A4-ID and A2-WY. The use of lithium nitrate with the slowly reactive
aggregate C2-SD was similarly evaluated using both C 1260 and accelerated C 1293
as indicated in Table 13.5.
ASTM C 1260, C 1293, and the accelerated C 1293 seem to produce comparable
results as far as the use of air entrainment. However, a major difference was noted in
Chapter 11 and 12. When using C 1260, increasing the air entrainment content
caused a decrease in the 14-day expansion of mortar bar made with all aggregates
investigated as indicated in Figure 13.5. When using ASTM C 1293 or the
accelerated C 1293, low contents of entrained air (2 to 4%) caused an increase in the
expansions of highly reactive aggregates as indicated in Figure 13.6 and 13.7. High-
entrained air contents (6 to 8%) were required to decrease the expansions of some
highly reactive aggregates (Figures 13.6 and 13.7). As a result, it was concluded that
using ASTM C 1260 to evaluate the effect of air entrainment should be avoided
because of the misleading results.
434
0.000.100.200.300.400.500.600.700.800.901.00
A6-NM A4-ID A2-WY C2-SD B4-VA E2-IA
Investigated Aggregate
14-D
ay E
xpan
sion
, % 0% Air Entrained2-4% Air Entrained6-8% Air Entrained
0.000
0.100
0.200
0.300
0.400
0.500
0.600
0.700
0.800
A6-NM A4-ID A2-WYAggregate Investigated
52-W
eek
(One
-Yea
r) E
xpan
sion
, % 0% Air0-2% Air2-4% Air4-6% Air 6-8% Air
Figure 13.5: Comparison of the 14-Day C 1260 Expansions for the Different Entrained Air Levels
Figure 13.6: Comparison Between the 52-week (One-Year) Expansions of the Different Aggregates and Air Entrainment Contents of Table 12.15
435
0.000
0.100
0.200
0.300
0.400
0.500
0.600
A4-ID A2-WY C2-SD A2-IA
Aggregate Investigated
13-W
eek
(3-m
onth
) Exp
ansi
on, %
0% Air2-4% Air6-8% Air
13.4 EVALUATING THE EFFECT OF CEMENT TOTAL ALKALI
CONTENT USING ASTM C 1260 AND ACCELERATED C 1293
Using different NaOH solution normalities, it was possible to evaluate the
reactivity of aggregates at different cement alkali contents using ASTM C 1260
(mortar-bar test). The accelerated C 1293, performed at 600C, was also used to
evaluate aggregate reactivity different cement alkali contents by changing the
Na2Oequiv. content of the mixtures. A comparison between the results of both tests is
presented in Table 13.6 where it can be seen that
1. The highly reactive aggregates A6-NM and A4-ID were reactive even at a
Na2Oequiv. content as low as 0.46%,
2. the highly reactive aggregate A2-WY required a 0.60% Na2Oequiv. content in
order to exhibit innocuous expansions, and
Figure 13.7: Comparison Between the 13-Week Expansions Generated Using the Accelerated C 1293 Procedures and the Different Air
Entrainment Contents
436
Table 13.6a: Effect of Na2Oequiv. Content on ASR Using ASTM C 1260 Na2Oequiv. Cement Content
1.15% 0.81% 0.46% NaOH Solution Normality Aggregate
ID
C 1260 14-Day
Expansiona 0.75Nb 0.50Nc 0.25Nc
A6-NM 0.91% H.R.
Reactive Reactive Reactive
A4-ID 0.79% H.R.
Reactive Reactive Reactive
A2-WY 0.29% H.R.
Reactive Reactive Innocuous
C2-SD 0.17% S.R.
Reactive Reactive Innocuous
aH.R. = ASTM C 1260 14-day expansion > 0.20% aS.R. = 0.10% < ASTM C 1260 14-day expansion < 0.20%
aInnocuous = ASTM C 1260 14-day expansion < 0.10% bReactive = 14-day expansion > 0.04% ; Innocuous = 14-day expansion < 0.04% cReactive = 14-day expansion > 0.02% ; Innocuous = 14-day expansion < 0.02%
Table 12.6b: Effect of Na2Oequiv. Content on ASR Using Accelerated C 1293
Na2Oequiv. Cement Content
Aggregate ID
C 1293 one-year Expansion
and Classification
Accelerated C 1293 13-Week Expansion and Classification 1.25% 0.90% 0.60%
A6-NM 0.411% Highly Reactive
0.407% Highly Reactive H.R. H.R. S.R.
A4-ID 0.379% Highly Reactive
0.396% Highly Reactive H.R. H.R. S.R.
A2-WY 0.107% Highly Reactive
0.083% Highly Reactive H.R. S.R. Innocuous
C2-SD 0.053% Slowly Reactive
0.059% Slowly Reactive S.R. Innocuous Innocuous
H.R. = Accelerated C 1293 13-week expansion > 0.070% S.R. = 0.040% < Accelerated C 1293 13-week expansion < 0.070%
Innocuous = Accelerated C 1293 13-week expansion < 0.040%
437
3. The slowly reactive aggregate C2-SD exhibited innocuous expansions when
tested using accelerated C 1293 (concrete-prism test) using a cement with 0.90%
Na2Oequiv.. However, when evaluated using the C 1260 (mortar-bar test), the
slowly reactive aggregate C2-SD required a cement alkali content of 0.46% for it
to exhibit innocuous expansions. As a result, it was concluded that the C 1260 is
a conservative estimation of the effect of Na2Oequiv. content on ASR.
4. Thus, at 0.60% Na2Oequiv., moderately and slowly reactive aggregates did not
show excessive expansions due to ASR. Highly reactive aggregates were still
reactive at levels lower that 0.60%.
13.5 EVALUATING THE EFFECTIVENESS OF MITIGATION
ALTERNATIVES WITH A 0.80% Na2Oequiv. CEMENT USING ASTM C
1260 AND ACCELERATED C 1293
Using ASTM C 1260 and the accelerated C 1293 (600C) it was possible to
determine the effectiveness of the mitigation alternatives using the highly reactive (C
1260 and C 1293) aggregate A6-NM in combination with a cement with 0.80%
Na2Oequiv. content. A comparison between the results of both tests is shown in Table
13.7, where it can be noted that with the exception of Class F fly ash and lithium
nitrate the minimum requirements were the same in both tests. The concrete-prism
test required higher levels of Class f fly ash and lithium nitrate. Thus, using a low
alkali cement (lower than 0.80%) allow for more flexibility in choosing an effective
ASR mitigating measure even with the most reactive aggregates like aggregate A6-
NM.
438
Table 13.7: Effective ASR Mitigation Alternatives for Highly Reactive Aggregate A6-NM (C1260 14-day of 0.92%) Evaluated Using a Cement Alkali
Content of 0.80% Na2Oequiv. Minimum Replacement
Levels by Weight of Cement Highly Reactive Aggregate
A6-NM
Minimum Replacement Levels by Weight of Cement Highly Reactive Aggregate
A6-NM Cementitious
Material C 1260 with 0.50N NaOH
(0.81% Na2Oequiv.) Accelerated C 1293 (0.80% Na2Oequiv.)
Calcined Clay 17% 17%
Granulated Slag 50% 50%
Class F Fly Ash 20% 25%
Silica Fume 10% 10%
Class C Fly Ash 35% 35%
Minimum LiNO3 Volume (weight) per 1 kg of Na2Oequiv.
Highly Reactive Aggregate A6-NM
Minimum LiNO3 Volume (weight) per 1 kg of Na2Oequiv.
Highly Reactive Aggregate A6-NM
Chemical Admixture
0.50N NaOH (0.81% Na2Oequiv.)
Accelerated C 1293 (0.80% Na2Oequiv.)
Lithium Nitrate 3.5 L 4.6 L
Air Entrainment
Shaded Areas = Alternative could not be used
439
CHAPTER FOURTEEN
GUIDELINES AND RECOMMENDATIONS
14.1 INTRODUCTION
This chapter includes guidelines for managing the alkali-silica reactivity of
aggregates. All recommendations and courses of action were based on the testing
performed using the provided aggregate samples and information gathered from
literature review. Conclusions generated throughout the study were analyzed and
organized to produce some guiding principles, detailed in this chapter, which could
be used to predict the alkali-silica reactivity of aggregates and to mitigate the
reaction of these aggregates in concrete.
14.2 PREDICTING THE POTENTIAL ALKALI-SILICA REACTIVITY OF
AGGREGATES
Predicting the potential alkali-silica reactivity of aggregates can be accomplished
either by monitoring their field performance records or by conducting accelerated
laboratory testing. Procedures are illustrated in Figure 14.1 and detailed in the
following sections.
14.2.1 Field Performance Record
Using the field performance of a particular aggregate might be the best method for
determining whether the aggregate is alkali-silica reactive or not. Choosing an
aggregate based on its field performance should be the result of a thorough
investigation that details the field applications of the aggregate. The main idea is to
use the aggregate in a proposed concrete that is identical to a field concrete being
exposed to similar environments. The following are some considerations that should
be addressed while assessing the field performance records (Bérubé and Fournier,
1993; CSA, 1994; etc.):
440
Aggregate CharacterizationFlow Chart I
Field Performance
History Available?
Yes
Is cement and alkali content of the
proposed concrete as high or lower than the
field concrete?
Is aggregate reactive in field concrete?
Is the field concrete at least
10 years old?
Yes
Are exposure conditions of field concrete at least as severe as proposed
concrete?
Are aggregate and W/CM in field concrete similar to that used in proposed concrete?
Yes
Yes
Yes
No
No
No
No
No
Yes
Accept Aggregate No Special Requirements
Reject or Take Preventive Measures
Flow Chart II
No
Figure 14.1: Flow Chart I for Assessing Aggregate’s Potential Alkali-Silica Reactivity
Does aggregate show13-week expansions higher than 0.040%?
Laboratory Testing Required
Mortar-Bar Test: ASTM C 1260
Does aggregate show 14-day expansions higher than 0.10%?
NoAccept aggregate No special requirements
Yes
C 1293 at 380C C 1293 at 600C
Does aggregate show1-year expansions
higher than 0.040%?
Yes
OR
No
Yes
No
Reject or Take Preventive Measures
Flow Chart II OR If time is available
Yes
Note: Use ASTM C 295 to verify the results ofC 1260 and
C 1293
ASTM C 295 couldn’t be
used to identify slowly
reactive aggregates
441
1. The cement content and the alkali content of the cement used in the new
proposed concrete should be lower than that of field concrete,
2. Examined field concrete should be at least 10 years old,
3. Exposure conditions of field concrete should be at least as severe as those of
proposed concrete,
4. The aggregate in field concrete should be identical to the aggregate used for the
proposed concrete. This should be verified by detailed documentation or by
petrographically examining field concrete,
5. The water-cementitious materials ratio used for the field concrete should be the
same as that used for the proposed concrete, and
6. Mixture proportions of field concrete, including the use of a mitigation
alternative, should be identical to the proportions of the proposed concrete.
If all the above conditions are satisfied, then the field performance record of the
aggregate can be used to determine its potential alkali-silica reactivity:
1. If the aggregate in the field concrete was alkali-silica reactive and has been
identified as the major cause of ASR damage, then the aggregate should not be
used in the proposed concrete or preventive measures should be considered.
2. If the aggregate in the field concrete was not alkali-silica reactive and has never
been identified as being the major cause of ASR damage, then the aggregate can
be used in the proposed concrete.
3. Reactivity of aggregates in field applications could be verified using SHRP C-
315 (Lead-State Team, 1999), Handbook for the Identification of Alkali-Silica
Reactivity in Highway Structures.
The field performance record could not be used to determine the degree of alkali-
silica reactivity. It is simply used to determine whether the aggregate has shown
signs of ASR in field applications. In addition, the conditions mentioned above are
442
usually very hard to determine, since information is often not available. That is why
predicting the potential reactivity of aggregates using accelerated laboratory testing
is very useful.
14.2.2 Laboratory Testing
Results generated throughout this study indicate that there are three testing
procedures that could be used solely or in combination in order to determine the
potential alkali-silica reactivity of aggregates. These tests are ASTM C 1260 (two-
week mortar bar test), ASTM C 1293 (52-week concrete prism test), and an
accelerated C 1293 (13-week concrete prism test). Figure 14.1 (Flow Chart I)
illustrates the use of these tests. Petrographic analysis performed in accordance to
ASTM C 295 could not be used to identify reactive materials in slowly reactive
aggregates. ASTM C 295 could be used to verify and confirm the results generated in
accordance to C 1260 and C 1293.
ASTM C 1260 is a mortar bar test that consists of testing aggregates using a
specified gradation. The aggregate being investigated is combined with a cement to
cast three 1-in. x 1-in. x 11-in. mortar bars that are moist cured for 24 hours while in
the molds. Bars are demolded and stored for another 24 hours in water maintained at
800C. Bars are then moved to a 1N NaOH solution maintained at 800C and kept in
this solution for 14 days. Length expansions of the bars are monitored periodically
over the 14-day period of testing.
ASTM C 1293 is a concrete prism test that consists of investigating the reactivity
of an aggregate while being used in a concrete mixture. The reactive aggregate
(coarse or fine) is combined with an innocuous aggregate (coarse or fine depending
on the reactive aggregates) and a cement with an alkali content of 0.9 ± 0.1% to cast
three 3-in. x 3-in. x 11-in. concrete prisms. The cement alkali content is increased to
443
1.25% Na2Oequiv. by adding NaOH to the mixing water. A cement content of 708 ±
17 lb/yd3, a coarse aggregate oven-dry-rodded unit volume of 0.70 ± 0.20%, and a
water-cement ratio between 0.42 and 0.45 are required for concrete proportioning.
Concrete prisms are moist cured for 24 hours while still in molds. Prisms are then
demolded, measured for their initial length, and stored over water, in a sealed 6-gal
bucket with wicks on the sides (100% R.H.). Buckets are then stored in an
environmental room maintaining a temperature of 38 ± 20C. Length expansions are
monitored periodically over a period of one year.
The accelerated C 1293 consists of performing the same exact procedure as the
standard C 1293 with the exception of storing the bucket in an environmental room
maintained at 60 ± 20C. These procedures generated identical results to the standard
C 1293 but in a 3-month (13-weeks) period of time.
Identifying the potential alkali-silica reactivity of aggregates using the above
testing procedures should be performed as indicated in Figure 14.1 and Table 14.1,
whereas determining the degree of alkali-silica reactivity of aggregates should be
completed as illustrated in Table 14.2.
444
Table 14.1: Expansion Limits for Identifying Potentially Alkali-Silica Reactive Aggregates
ASTM C 1260 Mortar Bar Test
ASTM C 1293 Concrete Prism Test
Accelerated C 1293 Concrete Prism Test
14-day Expansion > 0.10%a,b,c
one-year Expansion > 0.040%d
13-week Expansion > 0.040%d
a Several aggregates showing 14-day expansions higher than 0.10% have not caused ASR related damage in field application concretes and exhibited one-year expansions lower than 0.040% when tested in accordance to C 1293 and 13-week expansions lower than 0.040% when tested in accordance to the accelerated C 1293. C 1293 results should prevail. b In rare occasions, some aggregates known to be reactive in field applications might exhibit 14-day expansions lower than 0.10%. This is usually caused by the removal of part of the reactive constituents of the aggregate as a result of aggregate preparation. A petrographic analysis in accordance to ASTM C 295 can be used to identify these aggregates and prevent the negative results. c An expansion limit of 0.08% after 14-day should be used with metamorphic aggregates. d An expansion limit lower than 0.040% may be required if aggregate will be used in a critical structure such as a nuclear containment or large dams (CSA, 1994).
Table 14.2: Determination of the Degree of Alkali-Silica Reactivity of Aggregates
Degree of Alkali-Silica Reactivity
14-Day ExpansionUsing
ASTM C 1260b
One-Year Expansion
Using ASTM C 1293a,c
13-Week ExpansionUsing Accelerated
C 1293a,c
Highly Reactive > 0.20% > 0.070% > 0.070% Slowly Reactive 0.10% - 0.20% 0.040% - 0.070% 0.040% - 0.070%
Innocuous < 0.10% < 0.040% < 0.040% a ASTM C 1293 and accelerated C 1293 give the degree of reactivity for the combination of coarse and fine aggregates intended for the proposed concrete. If information about the combination is not available, then the degree of alkali-silica reactivity of the most expansive of the aggregates should be used to characterize the combination (CSA 1994). b ASTM C 1260 could not be used to test coarse and fine aggregate combinations. Each aggregate is tested separately and the largest test value should be used to determine the degree of alkali-silica reactivity. c If results of ASTM C 1260 and ASTM C 1293 contradict, then the results obtained using C 1293 should prevail.
445
14.3 MINIMIZING POTENTIAL FOR ASR-RELATED DAMAGE
Minimizing the potential for ASR related damage in a proposed concrete could be
achieved using a number of alternative approaches that are mainly dependent upon
the degree of alkali-silica reactivity of aggregates specified for the job. Results
generated throughout this investigation are summarized in Figure 14.3, which shows
the alternatives that passed C 1260 and the accelerated C 1293 for aggregates
investigated.
Different degrees of alkali-silica reactivity required different mitigation measures.
Mitigation alternatives included the use of sufficient amounts of Class C fly ash,
Class F fly ash, silica fume, granulated slag, and calcined clay to replace cement by
mass. Additional alternatives included the use of low alkali cement and the use of
lithium nitrate to replace a portion of the mixing water.
Effectiveness of alternatives listed in Figure 14.3 or any additional alternative
being considered for ASR mitigation should be verified using either ASTM C 1260
(mortar-bar test at 800C), C 1293 (concrete-prism-test at 380C), or the accelerated C
1293 (concrete-prism test at 600C) with the appropriate expansion limits. These tests
are also listed in Figure14.3.
When using ASTM C 1260, an alternative is considered effective in mitigating
ASR if it exhibits 14-day expansions lower than 0.10%. ASTM C 1260 can also be
used to investigate the effectiveness of lowering the alkali content of cement by
performing the test procedures using a NaOH solution molarity that corresponds to
the alkali content being investigated as determined by equation 14.1. When changing
the solution molarity, the expansion criterion should also be changed as shown in
Figure 14.2. ASTM C 1260 should not be used to evaluate the effectiveness of
lithium nitrate in mitigating ASR. Using equation 14.1 and Figure 14.2, ASTM C
446
1260 can also be used to investigate the effectiveness of a mitigation method used
with different cement alkali contents. However, it should be noted that these
procedures are quite conservative.
LmolescmwONaOH /06.0022.0
/2339.0][ ±+=− (Eq 14.1)
0.00
0.02
0.04
0.06
0.08
0.10
0.12
0 0.2 0.4 0.6 0.8 1 1.2
NaOH Solution Molarity
Exp
ansi
on C
rite
rion
, %
Figure 14.2: ASTM C 1260 Expansion Criteria Using Different NaOH Solution Molarities to Investigate Effectiveness of Cement Alkali Content
0.39 0.67 0.95 1.22 1.50 Corresponding Cement Na2Oequiv. as Determined by Eq. 14.1
447
Figure 14.3: Flow Chart II for Determining Effective Preventive Measures
Standard ASTM C 1293 Over water, 100% R.H., wicks, at 380C Expansion limit: 0.040% after 2 years
Accelerated ASTM C 1293 Over water, 100% R.H., wicks, at 600C Expansion limit: 0.040% after 26 weeks
Standard ASTM C 1260 In 1N NaOH solution at 800C Expansion limit: 0.10% after 14 days
ASR Preventive MeasuresFlow Chart II
Is aggregate highly
reactive?
Yes
Cement Na 2O equiv. < 0.08% - 17% Calcined Clay (min.) - 50% Slag (min.) - 25% Class F Fly Ash (min.) - 10% Silica Fume (min.) - 35% Class C Fly Ash (min.) - 4.6L of LiNO3 per 1Kg of Na2Oequ.
Higher Na 2O equiv. Cement - 25% Calcined Clay (min.) - > 55% Slag - 30% Class F Fly Ash (min.) - 50% Class C Fly Ash (min.)
Yes
No
Yes
- 17% Calcined Clay (min.) - 55% Slag (min.) - 25% Class F Fly Ash (min.) - 35% Class C Fly Ash (min.) - 10% Silica Fume (min.) - 4.6L LiNO3 per 1Kg of Na2O (min.)- < 0.90% Na2Oequiv. Cement No Special Requirements
Is aggregate slowly
reactive?
Is aggregate innocuous?
No
Yes
Is cement Na2Oequiv. less than 0.08%?
No
Verify Effectiveness of Alternative
Fly Ash, Calcined Clay, Slag, Silica Fume, or any Pozzolan
Reducing Cement Alkali Content
Standard ASTM C 1293 Over water, 100% R.H., wicks, at 380C Expansion limit: 0.040% after one year
Accelerated ASTM C 1293 Over water, 100% R.H., wicks, at 600C Expansion limit: 0.040% after 13 weeks
C 1260 with Corresponding MolarityNaOH solution at 800C: Equation 14.1 Expansion limit: Figure 14.2
Lithium Nitrate: LiNO3
448
When using ASTM C 1293, an expansion limit of 0.040% after 2 years of testing
is required to evaluate the effectiveness of supplementary cementitious materials
(SCM) such as fly ash, silica fume, granulated slag, and calcined clay. An expansion
limit of 0.040% after one year of testing should be used to evaluate the effectiveness
of air entrainment, low cement alkali content, and lithium nitrate.
When using the accelerated C 1293, an expansion limit of 0.040% after 26 weeks
of testing is required to evaluate the effectiveness of supplementary cementitious
materials (SCM) such as fly ash, silica fume, granulated slag, and calcined clay. An
expansion limit of 0.040% after 13 weeks of testing should be used to evaluate the
effectiveness of air entrainment, low cement alkali content, and lithium nitrate.
14.4 COST OF USING THE DIFFERENT MITIGATION ALTERNATIVES
Alternatives effective in mitigating ASR are listed in Figure 14.3. In this section a
comparison between the costs of using these alternatives is detailed. Table 14.3
includes the average costs used for the comparison. Assumptions used for the
comparison were as follows:
1. The cement content of the mixtures is 710 lb/yd3 (used throughout this
investigation),
2. Na2Oequiv. content in the mixtures is 3.67 kg/yd3, and
3. Cost included only cementitious materials cost and additives.
Table 14.3: Price Cost of Materials Used In Investigation Alternative Cost
Cement $70/ton Class F Fly Ash $23/ton Class C Fly Ash $26/ton
Silica Fume $0.35/lb Granulated Slag $65/ton Calcined Clay $82/ton
Lithium Nitrate $11/gal
449
Table 14.4: Cost of Using The Mitigation Alternatives for a Cementitious Material Content of 710 lb/yd3
Aggregate Reactivity Alternative
Cost of Cementitious
Materials Differential Cost
Cost of Cement Without any Replacement is $22/yd3
17% Calcined Clay $23/yd3 +4.54% 50% Granulated
Slag $22/yd3 +0.00%
25% Class F Fly Ash $19/yd3 -16.64%
10% Silica Fume $45/yd3 +104.54% 35% Class C Fly
Ash $18/yd3 -18.18%
Highly Reactive Aggregates Used with a
Cement having an total alkali content lower than 0.80%
Na2Oequiv. 4.6 L Lithium Nitrate per 1kg of
Na2Oequiv. $72/yd3 +227.27%
25% Calcined Clay $26/yd3 +18.18% 60% Granulated
Slag $22/yd3 +0.00%
Highly Reactive Aggregates
Without Restriction on
Na2Oequiv. Content 30% Class F Fly
Ash $18/yd3 -18.18%
17% Calcined Clay $23/yd3 +4.54% 55% Granulated
Slag $22/yd3 +0.00%
25% Class F Fly Ash $19/yd3 -16.64%
10% Silica Fume $45/yd3 +104.54%
Slowly Reactive Aggregates
< 0.90% Na2Oequiv. Cement $22/yd3 +0.00%
+ = Increase in price of cementitious materials - = Decrease in price of cementitious materials
450
Onl
y C
emen
t
17%
Cal
cine
d C
lay
50%
Gra
nula
ted
Slag
10%
Silic
a Fu
me
25%
Cal
cine
d C
lay
60%
Gra
nula
ted
Slag
17%
Cal
cine
d C
lay
55%
Gra
nula
ted
Slag
10%
Silic
a Fu
me
25%
Cla
ss F
Fly
Ash
< 0.
90%
Na2
Oeq
uiv
Cem
ent
30%
Cla
ss F
Fly
Ash
35%
Cla
ss C
Fly
Ash
25%
Cla
ss F
Fly
Ash
4.6L Lithium Nitrate per 1kg of Na2Oequiv
0
10
20
30
40
50
60
70
80C
ost,
$/yd
^3
14.5 ONE BEST ALTERNATIVE
The comparison of the alternatives was based on cost (Table 14.4 and Figure
14.4), effectiveness (Figures 12.72 through 12.75), and workability (Tables 7.12
through 7.19). Using this information, the following conclusions can be made:
1. Highly reactive aggregates without restriction on Na2Oequiv. content: As can be
seen from Table 14.4, it is possible to mitigate ASR for these aggregates using
25% calcined clay, 60% granulated slag, and 30% class F fly ash. It can also be
noted from Table 14.4 that using 30% Class F fly ash resulted in the lowest cost
that is actually $4 lower than the concrete made using only cement. In addition,
using Class F fly ash resulted in a good workable mix as indicated in Table 7.16.
Figure 14.4: Comparison Between the Cost of the Cementitious Materials of the Different Mitigation Alternatives
Cost of Only Cement
Highly Reactive Aggregate with <0.80% Na2Oequiv Cement
Highly Reactive Agg. No Na2Oequiv restriction
Slowly Reactive Aggregate
451
Thus, using 30% Class F fly ash is the alternative of choice for this aggregate
category.
2. Highly reactive aggregates used with a cement having an total alkali content
lower than 0.80% na2oequiv. Table 14.4 illustrates that using 35% Class C fly ash
and 25% Class F fly ash resulted in the mostly economical alternatives for this
aggregate category. Both of these alternatives had good workability as indicated
in Tables 7.15 (Class C) and 7.16 (Class F).
3. Slowly reactive aggregates: As indicated in Table 14.4, using 25% Class F fly
ash was the most economical alternative for these aggregates. Workability of
concrete mixtures made using 25% Class F fly ash was very good as indicated in
Table 7.16.
The use of Class F fly ash will result in a decrease in the price of the cementitious
materials of the mix and is capable of mitigating the reactivity of all aggregates if the
necessary percentage is used. The use of Class F fly ash appears to be the best
alternative for the mitigation of ASR.
14.6 CONCLUDING REMARKS
Depending on the degree of alkali-silica reactivity of aggregates, it is possible to
find an alternative that will decrease the expansion of the concrete or mortar
specimens below safe limits. Even the deleterious expansions of the mostly reactive
aggregate tested were decreased below safe limits using appropriate measures. It is
possible to determine the potential alkali-silica reactivity of aggregates and it is also
possible to mitigate even the mostly reactive aggregates. It should be noted that the
mitigation alternatives suggested apply only to the materials investigated whether
aggregates or admixtures. Properties of these aggregates and materials were
presented in Chapter 5.
452
CHAPTER FIFTEEN
SUMMARY OF CONCLUSIONS
15.1 INTRODUCTION
This chapter includes recommendations and conclusions generated by this study.
All conclusions and recommendations are based on the testing performed using the
provided aggregate samples. Conclusions and recommendations are true for the
tested aggregates and might not be appropriate for different aggregates. Each
aggregate has to be tested and evaluated individually.
15.2 ASSESSING AGGREGATE REACTIVITY
The following conclusions were generated on the use of ASTM C 1260 for
predicting the potential reactivity of aggregates:
1. ASTM C 1260 is valuable in identifying aggregates with reactivity varying from
innocuous to highly reactive.
2. A 14-day expansion of 0.10% should be used as the limit between reactive and
innocuous aggregates. Aggregates with expansions lower than 0.10% are
considered innocuous. Aggregates with 14-day expansions between 0.10% and
0.20% are considered slowly reactive. Aggregates with 14-day expansions higher
than 0.20% are considered highly reactive.
3. ASTM C 1260 is too severe for some aggregates (E2-IA and E6-IN) indicating
that they are reactive while the aggregates have good field performance and pass
C 1293. With other aggregates (A10-PA, E4-NV, and E8-NM), C 1260 over-
estimated the aggregate reactivity, indicating that they were highly reactive when
they were characterized as slowly reactive with the C 1293 procedures.
4. ASTM C 1260 should be used only as a screening method in combination with C
1293. C 1260 should not be solely used to determine the potential reactivity of
aggregates but should be supported by C 1293.
453
5. Increasing the testing time from 14 days to 56 days and using the limits of 0.33%
at 28 days and 0.48% at 56 days are not effective in predicting the correct
reactivity of aggregates. Slowly reactive aggregates did not pass these limits, and
Category E aggregates were still erroneously identified as reactive.
6. Using the polynomial fitting procedure for interpreting the C 1260 results is not
very accurate.
7. The Kolmogorov-Avrami-Mehl-Johnston model is more effective in representing
the C 1260 results. However, the model is a more sophisticated procedure for
generating the same conclusions as the standard C 1260 procedures. It does not
provide additional information.
8. Decreasing the normality of the testing solution can be used to determine the
effect of lowering the alkali content of cement. These procedures can also be
used to determine the effectiveness of mitigation alternatives at multiple alkali
contents. However, it should be noted that these procedures represent worst-case
scenarios and will give very conservative results.
9. An illustration of the use of ASTM C 1260 for aggregate characterization is
shown in the flow chart in Figure 15.1
The following conclusions were generated on the use of ASTM C 1293 for
predicting potential reactivity:
1. Innocuous aggregates showed one-year expansions lower than 0.040%. Slowly
reactive aggregates showed one-year expansions varying between 0.040% and
0.070%. Highly reactive aggregates experienced one-year expansions greater
than 0.070%.
2. E2-IA and E6-IN experienced innocuous one-year expansions lower than 0.040%
while A10-PA, E4-NV, and E8-NM exhibited one-year expansions between
0.040% and 0.070% indicating that they are slowly reactive.
3. Storing concrete prisms in a 1N NaOH solution at 800C was too severe for E2-IA
454
and E6-IN. With the exception of these two aggregates, using a 4-week
expansion limit of 0.040% allowed the correct classification of innocuous, slowly
reactive, and highly reactive aggregates. However, based on the results reported
in the literature, these procedures were not recommended.
4. Storing concrete prisms in a 1N NaOH solution at 380C resulted in E2-IA and
E6-IN having innocuous expansions slightly below the 0.040% limit after 26-
week of testing. The reactivity of innocuous, slowly reactive, and highly reactive
aggregates was correctly characterized using the 26-week expansion limit of
0.040%.
5. Storing concrete prisms over water, at 100% R.H., in sealed containers with
wicks, at 600C resulted in almost identical results as the standard C 1293 but in a
much shorter, 3-month, period of time. Using an expansion limit of 0.040% after
3 months of testing was effective, with all aggregates, in generating results
similar to the standard C 1293.
6. An illustration of the use of ASTM C 1293 for aggregate characterization is
shown in the flow chart in Figure 15.1
455
Potential Alkali-Silica Reactivity Characterization of Aggregates
ASTM C 1260 Mortar-Bar Test
Results required within 2 weeks No Time Constraint
14-day expansion > 0.20%
Innocuous Yes
No
0.10% < 14-day
expansion < 0.20%
Slowly Reactive
Yes
14-day expansion < 0.10%
Highly Reactive
Yes
No
ASTM C 1293 Concrete Prism Test
380C 600C
If ti
me
is a
vaila
ble
verif
y us
ing
AST
M C
129
3 Innocuous
One-year expansion< 0.040%
13-week expansion< 0.040%
Yes
No No
Slowly Reactive
0.040% < one-year
expansion< 0.070%
0.040% < 13-week
expansion< 0.070%
Yes
No No
Highly Reactive
One-year expansion> 0.070%
13-Week Expansion> 0.070%
Yes
Figure 15.1: Characterization of Aggregate Potential Alkali-Silica Reactivity
456
15.3 EFFECTIVE MITIGATION ALTERNATIVES
The following conclusions, summarized in Table 15.1 were generated using
ASTM C 1260 for assessing the effectiveness of mitigation alternatives:
1. Using up to 35% Class C fly ash to replace cement by weight was effective in
decreasing the 14-day expansions by about 80%. However, expansions of highly
reactive aggregates were still higher than the safe limit of 0.10%. This level was
effective with slowly reactive aggregates and one moderately reactive aggregate.
2. With the exception of A6-NM, replacing 25% of the weight of cement with Class
F fly ash was effective in decreasing the 14-day expansions of slowly and highly
reactive aggregates below 0.10%.
3. Using 10% silica fume to replace cement by weight was effective in decreasing
the 14-day expansions of slowly reactive aggregates below 0.10%. This level of
replacement was not effective with highly reactive aggregates even though it
caused a decrease in 14-day expansions of about 70%.
4. With the exception of A6-NM, replacing 55% of the cement weight with
granulated slag was effective in decreasing the 14-day expansions of slowly and
highly reactive aggregates below 0.10%. It took 70% slag in order for the 14-day
expansions of all aggregates to decrease below 0.10%.
5. Using 17% calcined clay to replace cement by weight was effective in decreasing
14-day expansions below 0.10% with slowly reactive aggregates and one highly
reactive aggregate. This level caused a decrease of about 80% in the 14-day
expansions of highly reactive aggregates. Replacing 25% of the cement weight
with calcined clay was effective in decreasing the 14-day expansions below
0.10% for slowly and highly reactive aggregates.
6. Using 2 to 4% entrained air caused between 30 and 50% decrease in the 14-day
expansions. However, 14-day expansions of the five aggregates were still much
higher than the 0.10% limit. Using 6 to 8% entrained air did not result in an
additional decrease in expansions. Entrained air was not effective in mitigating
457
deleterious expansions of slowly, moderately, or highly reactive aggregates.
Table 15.1: Effectiveness of the Mitigation Alternatives Using the 14-Day C 1260 Test with 0.10% Criteria
Aggregate, 14-day expansion, C 1260 Classification A6-NM 0.91% (H.R.)
A4-ID 0.79% (H.R.)
A2-WY 0.29% (H.R.)
C2-SD 0.17% (S.R.)
B4-VA 0.15% (S.R.)
E2-IA 0.42% (H.R.) Cementitious
Materials Replace.
Level C 1260 Reactivity Classification 20% H.R. H.R. H.R. S.R. S.R. H.R.
27.5% H.R. H.R. H.R. S.R. Innocuous H.R. Class C Fly Ash
35% H.R. S.R. S.R. Innocuous Innocuous S.R. 15% H.R. H.R. S.R. S.R. Innocuous S.R. Class F
Fly Ash 25% S.R. S.R. Innocuous Innocuous Innocuous Innocuous 5% H.R. H.R. H.R. S.R. S.R. H.R. Silica
Fume 10% S.R. S.R. S.R. Innocuous Innocuous S.R. 40% H.R. H.R. S.R. S.R. Innocuous S.R. 55% S.R. Innocuous Innocuous Innocuous Innocuous Innocuous
Granulated Slag
70% Innocuous Innocuous Innocuous Innocuous Innocuous Innocuous 17% S.R. S.R. S.R. Innocuous Innocuous S.R. Calcined
Clay 25% Innocuous Innocuous Innocuous Innocuous Innocuous Innocuous Aggregate, 14-day expansion, C 1260 Classification
Chemical Materials Dosage
A6-NM 0.91% (H.R.)
A4-ID 0.79% (H.R.)
A2-WY 0.29% (H.R.)
C2-SD 0.17% (S.R.)
B4-VA 0.15% (S.R.)
E2-IA 0.42% (H.R.)
21 g H.R. H.R. Innocuous S.R. Innocuous Innocuous 28 g H.R. H.R. Innocuous Innocuous Innocuous Innocuous
Lithium Nitrate
60 g H.R. S.R. Innocuous Innocuous Innocuous Innocuous 4% H.R. H.R. S.R. S.R. Innocuous S.R. Entrained
Air 8% H.R. H.R. S.R. S.R. Innocuous S.R. H.R. = Highly Reactive = C 1260 14-day expansion > 0.20% S.R. = Slowly Reactive = 0.10% < C 1260 14-day expansion < 0.20%
Innocuous = C 1260 14-day expansion < 0.10%
7. Using a minimum of 4.6L LiNO3 to replace a volume of mixing water equal to
85% of the volume of the LiNO3 added was effective in decreasing the 14-day
expansions of slowly reactive aggregates below 0.10%. Using 10L LiNO3 was
not effective with highly reactive aggregates.
8. Increasing the water-cement ratio from 0.35 to 0.65 caused the 14-day
expansions to be highest for concretes with w/c of 0.35 and lowest with w/c of
458
0.65. For testing, aggregates with a w/c of 0.47 (standard) was used throughout
the study.
9. When the normality of solution was decreased to 0.50N and 0.35N (0.80% and
0.60% Na2Oequiv., respectively), alternatives effective in decreasing the 14-day
expansions of highly reactive aggregates below safe levels included replacing the
cement weight with a minimum of 25% calcined clay, 50% slag, 20% Class F fly
ash, 10% silica fume, or 35% Class C fly ash. Using a minimum of 4.6L LiNO3
to replace a volume of mixing water equal to 85% of the volume of the LiNO3
added was also effective at these normalities. This is illustrated in Table 15.2.
Table 15.2: Effective ASR Mitigation Alternatives for Highly Reactive Aggregate A6-NM (C1260 14-Day Expansion of 0.92%) Evaluated Using C 1260
with 0.75N, 0.50N, & 0.35N NaOH Solutions Minimum Replacement Levels by Weight of Cement
Highly Reactive Aggregate A6-NM Cementitious
Material 1N NaOH
(1.5%Na2Oequiv.)0.75N NaOH
(1.15%Na2Oequiv.)0.50N NaOH
(0.81%Na2Oequiv.) 0.35N NaOH
(0.60%Na2Oequiv.)Calcined
Clay 25% 25% 17% 17%
Granulated Slag 70% 55% 50% 50%
Class F Fly Ash 40% 25% 20% 20%
Silica Fume 10% 10%
Class C Fly Ash 50% 50% 35% 35%
Minimum LiNO3 Volume (weight) per 1 kg of Na2O Highly Reactive Aggregate A6-NM
Chemical Admixture
1N NaOH (1.5%Na2Oequiv.)
0.75N NaOH (1.15%Na2Oequiv.)
0.50N NaOH (0.81%Na2Oequiv.)
0.35N NaOH (0.60%Na2Oequiv.)
Lithium Nitrate 3.5 L (4.18 kg) 3.5 L (4.18 kg)
Shaded Areas = Alternative could not be used
459
The following conclusions, summarized in Table 15.3, were generated using
ASTM C 1293 for assessing the effectiveness of mitigation alternatives:
1. Class C fly ash was not an effective alternative for mitigating the alkali-silica
reactivity of highly reactive aggregates, A4-ID and A2-WY. Thirty-five percent
Class C fly ash, by weight of cement was needed to decrease the expansions of
the slowly reactive aggregate C2-SD to safe levels.
2. A minimum of 25% Class F fly ash was effective with the moderately reactive
aggregate A2-WY and the slowly reactive aggregate C2-SD but not with the
highly reactive aggregate A4-ID.
3. Silica fume was not effective with A4-ID (H.R.) and A2-WY (M.R.). A
minimum of 10% silica was required to mitigate ASR of the C2-SD (S.R.).
4. A minimum of 55% granulated slag was effective in mitigating ASR of all
aggregates investigated. Lower slag contents were not effective.
5. A minimum of 25% calcined clay was effective in mitigating ASR of all
aggregates investigated. Seventeen percent was only effective with the slowly
reactive aggregates
6. Air entrainment was not effective in mitigating ASR. Lower entrained air
contents were detrimental to the reaction causing an increase in expansion.
7. A minimum of 4.6 l per 1 kg of Na2Oequiv. in the mixture was effective in
mitigating the alkali-silica reactivity of all aggregates investigated.
8. Using a cement alkali content of 0.90% Na2Oequiv. was effective in mitigating the
alkali-silica reactivity of the slowly reactive aggregate C2-SD. An alkali content
of 0.60% Na2Oequiv. was needed to mitigate the alkali-silica reactivity of
moderately reactive aggregate A2-WY. The highly reactive aggregate A4-ID was
still showing signs of reactivity even at low alkali contents.
9. Using Class F fly ash resulted in the most economical and effective mitigation
alternative.
460
Table 15.3: Effectiveness of the Mitigation Alternatives Using the Accelerated C 1293 Criteria
Aggregate ID, 13-Week Expansion, C 1293 Reactivity Classification
Cementitious Material
Replacement Level By Weight of Cement
A4-ID 0.396% Highly
Reactive
A2-WY 0.083% Highly
Reactive
C2-SD 0.059% Slowly
Reactive
E2-IA 0.028%
Innocuous
20% H.R. H.R. S.R. Innocuous27.5% H.R. H.R. S.R. InnocuousClass C
Fly Asha
35% S.R. S.R. Innocuous Innocuous15% H.R. S.R. S.R. InnocuousClass F
Fly Asha 25% S.R. Innocuous Innocuous Innocuous5% H.R. H.R. S.R. InnocuousSilica
Fumea 10% S.R. S.R. Innocuous Innocuous25% H.R. S.R. S.R. Innocuous55% Innocuous Innocuous Innocuous InnocuousGranulated
Slaga
70% Innocuous Innocuous Innocuous Innocuous17% S.R. S.R. Innocuous InnocuousCalcined
Claya 25% Innocuous Innocuous Innocuous InnocuousAggregate ID, 13-Week Expansion, C 1293
Reactivity Classification
Chemical Material Dosage
A4-ID 0.396% Highly
Reactive
A2-WY 0.083% Highly
Reactive
C2-SD 0.059% Slowly
Reactive
E2-IA 0.028%
Innocuous
Lithium Nitrateb 315 g H.R. S.R. S.R. Innocuous
495 g Innocuous Innocuous Innocuous Innocuous 900 g Innocuous Innocuous Innocuous Innocuous
Entrained Airb 2 - 4% H.R. H.R. S.R. Innocuous
6 - 8% H.R. H.R. S.R. InnocuousaH.R. = Accelerated C 1293 26-week expansion > 0.070% aS.R. = 0.040% < Accelerated C 1293 26-week expansion < 0.070%
aInnocuous = Accelerated C 1293 26-week expansion < 0.040%
bH.R. = Accelerated C 1293 13-week expansion > 0.070% bS.R. = 0.040% < Accelerated C 1293 13-week expansion < 0.070%
bInnocuous = Accelerated C 1293 13-week expansion < 0.040%
461
Table 15.3 (Cont’d): Effectiveness of the Mitigation Alternatives Using the Accelerated C 1293 Criteria
Cementitious Material
Na2Oequiv. Content
A6-NM 0.407% Highly
Reactive
A4-ID 0.396% Highly
Reactive
A2-WY 0.083% Highly
Reactive
C2-SD 0.059% Slowly
Reactive 0.90% H.R. H.R. S.R. Innocuous0.60% S.R. S.R. Innocuous InnocuousCementb
6 - 8% H.R. H.R. S.R. InnocuousbH.R. = Accelerated C 1293 13-week expansion > 0.070% bS.R. = 0.040% < Accelerated C 1293 13-week expansion < 0.070%
bInnocuous = Accelerated C 1293 13-week expansion < 0.040%
A summary of the minimum requirements for ASR mitigation is included in Tables
15.4 and 15.5.
462
Table 15.4: Effective ASR Mitigation Alternatives Aggregate ID, 13-Week Accelerated C 1293 Expansion, Classification
A4-ID 0.396%
Highly Reactive
A2-WY 0.083%
Highly Reactive
C2-SD 0.059%
Slowly Reactive
E2-IA 0.028%
Innocuous Cementitious Material Minimum Replacement Level by Weight of Cement Calcined
Clay 25% 25% 17% 0%
Granulated Slag 55% 55% 55% 0%
Class F Fly Ash > 25% 25% 25% 0%
Silica Fume 10% 0%
Class C Fly Ash 50% 50% 35% 0%
Minimum Cement Na2Oequiv. Content Cement 0.60% 0.90% Not Applicable
Chemical Admixture Minimum LiNO3 Volume (weight) per 1 kg of Na2Oequiv.
Lithium Nitrate 4.6 L (495 kg) 4.6 L (495 kg) 4.6 L (495 kg) 0L
Shaded Areas = Alternative could not be used
463
Table 15.5 Effective ASR Mitigation Alternatives for Highly Reactive Aggregate A6-NM (ASTM C 1293 one-year expansion of 0.411%) Using 0.80% Na2Oequiv.
Cement
Cementitious Material Minimum Replacement Levels by Weight of Cement
Calcined Clay 17%
Granulated Slag 50%
Class F Fly Ash 25%
Silica Fume 10%
Class C Fly Ash 35%
Chemical Material Minimum LiNO3 Volume (Weight) per 1 kg of Na2Oequiv.
Lithium Nitrate 4.6 L (495 kg)
Air Entrainment
Shaded Areas = Alternative could not be used
15.3 Final Remarks
After completing the testing program and examining the results, it was possible to
see how different aggregates required different procedures for the identification of
levels of ASR and for the mitigation of the reaction. Throughout the study,
procedures for predicting the alkali-silica reactivity of aggregates were detailed and
alternatives for mitigating ASR were presented. The correct identification of the
potential alkali-silica reactivity of aggregates would allow for the use of appropriate
mitigating alternatives and hence prevent excessive expansions that cause concrete
damage. In addition, the presented mitigation alternatives will allow the use of
reactive aggregates in durable concrete structures without having the risk of ASR. It
is believed that results from this study will enhance the state-of-the-art of ASR
testing and prevention and will support a more efficient use of aggregate sources.
465
0
0.08
0.16
0.24
0.32
0.4
0 4 8 12 16 20 24 28 32
Time, Day
Exp
ansi
on, % A1-WY 1N
A1-WY 0.75NA1-WY 0.50NA1-WY 0.25N
0
0.08
0.16
0.24
0.32
0.4
0 4 8 12 16 20 24 28 32
Time, Day
Exp
ansi
on, % A2-WY 1N
A2-WY 0.75NA2-WY 0.50NA2-WY 0.25N
466
00.10.20.30.40.50.60.70.80.9
1
0 4 8 12 16 20 24 28 32
Time, Day
Exp
ansi
on, % A4-ID 1N
A4-ID 0.75NA4-ID 0.50NA4-ID 0.25N
00.10.20.30.40.50.60.70.80.9
11.11.2
0 4 8 12 16 20 24 28 32
Time, Day
Exp
ansi
on, % A6-NM 1N
A6-NM 0.75NA6-NM 0.50NA6-NM 0.25N
467
0
0.08
0.16
0.24
0.32
0.4
0.48
0.56
0 4 8 12 16 20 24 28 32
Time, Day
Exp
ansi
on, % A7-NC 1N
A7-NC 0.75NA7-NC 0.50NA7-NC 0.25N
0
0.08
0.16
0.24
0.32
0.4
0.48
0 4 8 12 16 20 24 28 32
Time, Day
Exp
ansi
on, % A9-NE 1N
A9-NE 0.75NA9-NE 0.50NA9-NE 0.25N
468
0
0.08
0.16
0.24
0.32
0.4
0.48
0.56
0 4 8 12 16 20 24 28 32
Time, Day
Exp
ansi
on, % A10-PA 1N
A10-PA 0.75NA10-PA 0.50N
0
0.08
0.16
0.24
0 4 8 12 16 20 24 28 32
Time, Day
Exp
ansi
on, % B2-MD 1N
B2-MD 0.75NB2-MD 0.50NB2-MD 0.25N
469
0
0.08
0.16
0.24
0.32
0 4 8 12 16 20 24 28 32
Time, Day
Exp
ansi
on, % B4-VA 1N
B4-VA 0.75NB4-VA 0.50NB4-VA 0.25N
0
0.08
0.16
0.24
0.32
0 4 8 12 16 20 24 28 32
Time, Day
Exp
ansi
on, % C2-SD 1N
C2-SD 0.75NC2-SD 0.50NC2-SD 0.25N
470
0
0.005
0.01
0.015
0.02
0.025
0.03
0.035
0 4 8 12 16 20 24 28 32
Time, Day
Exp
ansi
on, % D2-IL 1N
D2-IL 0.75ND2-IL 0.50ND2-IL 0.25N
00.080.160.240.320.4
0.480.560.640.72
0 4 8 12 16 20 24 28 32
Time, Day
Exp
ansi
on, % E2-IA 1N
E2-IA 0.75NE2-IA 0.50NE2-IA 0.25N
471
00.080.160.240.320.4
0.480.560.640.72
0 4 8 12 16 20 24 28 32
Time, Day
Exp
ansi
on, % E4-NV 1N
E4-NV 0.75NE4-NV 0.50NE4-NV 0.25N
0
0.08
0.16
0.24
0.32
0.4
0.48
0 4 8 12 16 20 24 28 32
Time, Day
Exp
ansi
on, % E6-IN 1N
E6-IN 0.75NE6-IN 0.50NE6-IN 0.25N
472
00.080.160.240.320.4
0.480.560.64
0 4 8 12 16 20 24 28 32
Time, Day
Exp
ansi
on, % E8-NM 1N
E8-NM 0.75NE8-NM 0.50NE8-NM 0.25N
473
Appendix B
VARIABLES FOR THE KOLMOGOROV-AVRAMI-MEHL-JOHNSTON
MODEL USING C 1260 EXPANSIONS UP TO 28 DAYS
474
-9.0-8.0-7.0-6.0-5.0-4.0-3.0-2.0-1.00.0
A6-NM A4-ID A2-WY C2-SD B4-VA
Ln
(K)
20% Class C27.5% Class C35% Class C15% Class F25% Class F
-10.0-9.0-8.0-7.0-6.0-5.0-4.0-3.0-2.0-1.00.0
A6-NM A4-ID A2-WY C2-SD B4-VA
Ln
(K)
5% Silica Fume10% Silica Fume40% Slag55% Slag70% Slag
475
-10.0-9.0-8.0-7.0-6.0-5.0-4.0-3.0-2.0-1.00.0
A6-NM A4-ID A2-WY C2-SD B4-VA
17% Calcined Clay
25% Calcined Clay
21g LithiumNitrate28g Lithium
-10.0-9.0-8.0-7.0-6.0-5.0-4.0-3.0-2.0-1.00.0
A6-NM A4-ID A2-WY C2-SD B4-VA
Ln
(K)
4% Entrained Air8% Entrained AirW/C = 0.35W/C = 0.55W/C = 0.65
476
0.0
0.5
1.0
1.5
2.0
2.5
A6-NM A4-ID A2-WY C2-SD B4-VA
Con
stan
t M
20% Class C27.5% Class C35% Class C15% Class F25% Class F
0.0
0.5
1.0
1.5
2.0
2.5
A6-NM A4-ID A2-WY C2-SD B4-VA
Con
stan
t M
5% Silica Fume10% Silica Fume40% Slag55% Slag70% Slag
477
25% Calcined Clay -8.15699 -6.71853 -6.22177 -6.34958 -8.2813321g Lithium Nitrate -2.94618 -2.75198 -4.96673 -4.63047 -6.5002128g Lithium Nitrate -3.02742 -2.94918 -5.5054 -5.64496 -6.6255360g Lithium Nitrate -4.00186 -5.37417 -6.44735 -6.55925 -7.73977
ln k ln k ln k ln k ln kA6-NM A4-ID A2-WY C2-SD B4-VA
4% Entrained Air -3.44152 -2.76035 -3.80067 -4.47041 -4.898288% Entrained Air -2.64584 -2.82111 -4.14823 -4.33586 -4.89649
W/C = 0.35 -2.36331 -1.9446 -3.11906 -4.50455 -4.6858W/C = 0.55 -2.16651 -2.31688 -3.97906 -4.66743 -4.46676W/C = 0.65 -2.3739 -2.63112 -4.4314 -5.27792 -4.50453
0.0
0.5
1.0
1.5
2.0
2.5
3.0
A6-NM A4-ID A2-WY C2-SD B4-VA
Con
stan
t M
4% Entrained Air8% Entrained AirW/C = 0.35W/C = 0.55W/C = 0.65
478
0.0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
-10.0 -8.0 -6.0 -4.0 -2.0 0.0Ln (K)
Con
stan
t M 20% Class C27.5% Class C35% Class C15% Class F25% Class F
0.0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
-10.0 -8.0 -6.0 -4.0 -2.0 0.0Ln (K)
Con
stan
t M
5% Silica Fume10% Silica Fume40% Slag55% Slag70% Slag
480
0.0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
-10.0 -8.0 -6.0 -4.0 -2.0 0.0Ln (K)
Con
stan
t M
4% Entrained Air8% Entrained AirW/C = 0.35W/C = 0.55W/C = 0.65
480
Appendix C
EFFECTIVE LEVELS OF CEMENT REPLACEMENT WITH CLASS C FLY
ASH, CLASS F FLY ASH, AND SILICA FUME EVALUATED USING THE
K-M-A-J’S MODEL FOR A6-NM, A4-ID,
A2-WY, C2-SD, AND B4-VA
481
A6-NM, Highly Reactive Aggregate
-8
-7
-6
-5
-4
-3
-2
-1
0
0 20 40 60 80 100 120Percent Replacemnt of Cement by Weight
ln(k
)
Class C Fly AshClass F Fly AshSilica Fume
A4-ID, Highly Reactive Aggregate
-8
-7
-6
-5
-4
-3
-2
-1
0
0 20 40 60 80 100 120
Percent Replacement of Cement by Weight
ln(k
) Class C Fly AshClass F Fly AshSilica Fume
482
A2-WY, Highly Reactive Aggregate
-8
-7
-6
-5
-4
-3
-2
-1
0
0 20 40 60 80 100 120
Percent Replacement of Cement by Weight
ln(k
)
Class C Fly AshClass F Fly AshSilica Fume
B4-VA, Slowly Reactive Aggregate
-8
-7
-6
-5
-4
-3
-2
-1
0
0 20 40 60 80 100 120Percentage Replacemnt of Cement by
Weight
ln(k
) Class C Fly AshClass F Fly AshSilica Fume
483
C2-SD, Slowly Reactive Aggregate
-8
-7
-6
-5
-4
-3
-2
-1
0
0 20 40 60 80 100 120Percentage Replacemnt of Cement by
Weight
ln(k
) Class C Fly AshClass F Fly AshSilica Fume
484
Appendix D:
Petrographic Analysis and Field Performance Documentation of Aggregates Investigated
485
WYOMING AGGREGATES: A1-WY AND A2-WY The Wyoming DOT provided a coarse (A1-WY) and a fine aggregate (A2-WY) from the same source. The aggregate is a rhyolite and has been used extensively in the Wyoming area in structures varying from sidewalks to highway structures. It was reported that this aggregate is alkali-silica reactive. It was used in a section of Interstate 80 (I 80) and the section was heavily deteriorated due mainly to ASR. Since then, the deteriorated section was removed and replaced using non-reactive aggregates. It was also reported that signs of ASR, caused by the reactivity of this aggregate, can be seen all over the Wyoming area, namely, in sidewalks, poles, and driveways. IDAHO AGGREGATES: A3-ID AND A4-ID The Idaho DOT provided a coarse (A3-ID) and a fine (A4-ID) aggregate from the same source. The aggregate is a combination of quartzite, sandstone, limestone, andesite, and rhyolite. This aggregate is a Snake River deposit. Historically aggregates from that river were used in bridge deck sections of the US 26. The decks were heavily deteriorated due to ASR. Recent use of the aggregate is confined to asphalt hot mixes and chip seals. However, there are several occasions where the aggregate was used in portland cement concrete. “In 1993 aggregate from the source being investigated was used in two concrete bridge decks, the lower Payette Canal and Payette River Slough bridge decks. For the lower Payette Canal Deck, Type K cement was used to evaluate its effect on shrinkage cracking. No fly ash nor other ASR mitigation measures were used in either deck, except that low alkali cement was specified. Chip seals are present, so the full deck surface is not visible. According to the most recent maintenance inspection reports (in 1998), “the chip seals are worn away in some spots and there are narrow bare strips along the curbs. Some cracking is visible (more cracking on deck w/o type K), but at this point it appears to be shrinkage cracking rather than the more irregular map cracking. This leads us to believe that ASR, if present, isn’t very far advanced at this time (Stanley, A.F. 1999 Interview).” ASTM C 1260 results for both the coarse and fine aggregates were also reported. Mortar bars were not stored in hot water before storing them in the 1N NaOH solution. For the fine aggregate the 14-day expansions reported were 0.78% and 0.92%. The reported 14-day expansions for the coarse aggregates were 0.69% and 0.70%. NEW MEXICO AGGREGATES: A5-NM (PL), A6-NM (PL), E7-NM (SA),
AND E8-NM (SA) There were two aggregates that originated from New Mexico. Coarse and fine aggregate samples from each aggregate were made available for investigating. The following is a presentation of their reported properties.
486
Petrographic Analysis: A5-NM and A6-NM Petrographic examination of A5-NM (coarse) and A6-NM (fine) indicates a volcanic-and-metamorphic-rock suite of rocks in the coarse aggregate. The coarse-aggregate fractions are dominated by various tuffs, andesites, and basalts of volcanic origins, and gneisses and metaquartzites of metamorphic origin. Each sieve fraction contains potentially alkali-reactive constituents, mainly tuffs and andesites having a wide range in percentages of crystals, devitrified glass, and rock (lithic) fragments. Almost all of the tuffs are devitrified, that is, the glass that once comprised the volcanic ash shards has crystallized and compressed, forming unusually small crystals of cristoballite and other silica minerals, now making up a silica-rich matrix showing only hints of the previously particulate rock. Numerous potentially reactive andesitic rocks having an extremely finely microcrystalline matrix (in which the larger crystals are set), make up roughly 30% of the andesite-basalt category. Within the gneiss category are several varieties of finely crystalline, banded rocks in which the mineral constituents exhibit the effects of directed metamorphic stresses. These particular aggregates are also potentially reactive. Chert (microcrystalline and chalcedonic quartz) was noted in some of the sieve fractions. Its microcrystalline structure clearly suggests potential alkali reactivity.
Thus, in general, approximately 20 to 30% of the A5-NM and A6-NM materials in each of the sieve intervals are easily classified as potentially reactive. Approximately 99% of the aggregate particles are considered very hard and durable, showing little tendency to break apart. No caliche coatings were observed. The large majority of the particles are equidimensional to slightly elongated and flattened. Particle surfaces are generally smooth, except where the particle has been crushed. These morphologies typically produce concrete mixes having a normal water demand.
487
Percentages of Constituents in Each Sieve Fraction of A5-NM Retained on: 3/4 1/2 3/8 No. 4
Tuffs 3.0 6.2 7.1 3.7 Rhyolite and Trachyte 7.1 14.9 7.7 6.4 Andesite and Basalt 38.5 37.9 41.8 52.1 Granite and Syenite 8.9 7.5 10.6 12.2 Diabase 0.6 - - - Gneiss 8.9 3.7 7.1 4.3 Metaquartzite 28.4 26.7 14.7 10.1 Metaporphyry 1.2 1.2 2.9 - Feldspar - - 2.9 6.4 Quartz - - 1.8 2.7 Chert 0.6 - - 1.6 Limestone - - - 0.5 Sandstone, Siltstone 3.0 1.9 3.5 -
Percentages of Constituents in Each Sieve Fraction of A6-NM Retained on: No.8 16 30 50 100 Dust
Tuffs 7.1 3.1 6.8 2.1 2.8 - Rhyolite and Trachyte 3.3 2.6 1.2 - - - Andesite and Basalt 44.2 36.5 24.1 18.6 22.2 26.1 Granite and Syenite 11.7 8.3 7.4 3.6 1.1 - Diabase - - - 0.5 - - Gneiss 4.6 5.7 1.9 4.1 3.3 - Metaquartzite 3.9 8.2 3.1 5.7 2.8 - Metaporphyry 8.4 2.1 - 1.6 0.6 - Feldspar 7.8 13.5 19.8 23.7 26.1 29.6 Quartz - 13.5 35.2 35.1 32.2 14.8 Chert 3.9 2.1 - - 1.1 - Limestone - 1.6 - - - - Sandstone, Siltstone 3.3 1.6 0.6 0.5 - - Shale, Argillite 2.0 - - - - - Ferro-magnesian minerals - - - 0.5 2.2 5.6 Opaque (iron-rich minerals) - - - - 1.6 6.3 Volcanic Glass - 2.1 - 4.1 3.9 14.1 Others - - - - - 3.5
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Reported ASTM C 1260 Results A5-NM and A6-NM were reported as reactive aggregates with a 14-day expansion of 1.04% when tested using C 1260 procedures in 1997. E7-NM and E8-NM were reported as potentially reactive aggregates with a 14-day expansion of 0.34%. Field Performance A5-NM and A6-NM have been established as being reactive aggregates. As a result the aggregate is not used in portland cement concrete structures without an ASR mitigating method. E7-NM and E8-NM have been reported as having good field performance with mitigation alternatives. NORTH CAROLINA AGGREGATE: A7-NC A coarse aggregate from North Carolina was made available for the study. The following are some of the aggregate properties that were reported. Petrographic Analysis The following is a summary of a petrographic analysis report that was completed on the aggregate in question on February 2, 1993. The types of aggregate identified are described as follows: Slate Rock Type: Light to medium green-gray and medium to dark blue-gray, very fine to fine-grained slate (argillite) Mineralogy: The mineralogy is very hard to determine due to fine-grained particles; however, it is evident that some percentage of the rock is comprised of clay, chlorite, quartz, and feldspar with a trace to 2% sulphides. Particle Shape: Angular to subangular, triangular to tabular with occasional rectangular fragments Degree of Weathering: Fresh with some weathered fragments. Deleterious Materials: This slate most likely derived much of its materials from the surrounding volcanic rocks, and therefore, may contain volcanic glass. Other: Carbonate and sulphides are present on fracture surfaces and along bedding planes and foliation planes. Tuff Rock Type: Medium gray, aphanitic (very fine-grained) and fine to medium-grained tuff/tuffaceous sediment. Mineralogy: Mineralogy is hard to determine; however, some percentage of the rock is comprised of chlorite, feldspar, epidote, and carbonate. Particle Shape: Angular to subangular. Degree of Weathering: Fresh to slightly weathered.
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Deleterious Materials: Volcanic Glass may be one of the constituents of this type of rock since it is of volcanic origin. In conclusion, the minerals present in the aggregate may have potential for alkali reactivity, pending the success of ASTM C 287 tests for aggregate. Field and Laboratory Performance In the spring of 1987, members of a Federal Highway inspection tour observed extensive pattern cracking in the wing walls of the James Garrison Bridge over the Tillery on NC 24-27-73. Constructed during 1977-78, this structure exhibited no noticeable cracking in the superstructure until 1982 when cracking in the end bents and wing walls was photographed. A 1984 inspection report noted cracking on the deck, abutment, and back walls of end bents, pier caps, and columns. Cracking has continued to progress and although the cracking is most extensive in the wing walls and caps, some cracking is present in all components of the bridge structure. It has been noted that presence and condition of these cracks is worse than some 50 year old bridges. A7-NC was the coarse aggregate used for that bridge in combination with a Type I cement, widely used sand, city water, and widely used chemical admixtures. A7-NC, which is reported as a meta-argillite, is used infrequently in concrete, but easily passes the standard quality tests for wear and soundness. Intact concrete cores were taken from the structure and examined. The cores showed a compressive strength in excess of 7000 psi and cracking that is best described as pattern or map cracking. Cracks on the surface typically extend only an inch or two in depth before disappearing into a myriad of many finer cracks. Concrete specimens obtained from cores are characterized by fractured aggregates with dark rims around the coarse aggregate portion. White deposits are present on the fractured faces of the coarse aggregate. Petrographic examinations confirmed alkali-silica reactivity. It was estimated that the alkali content of the cement is 0.70%.
A7-NC was also used in the construction of NC 138 over Long Creek between Oakboro and Aquadale. NC 138 was identified as exhibiting cracking due to the alkali-aggregate reactivity of A7-NC. Because the construction records for that bridge were destroyed, an extensive laboratory-testing program was conducted in order to verify the reactivity of the aggregate. The tests performed included:
1. Petrographic Examination, ASTM C 295 and C-856 2. Rock Cylinder Test, ASTM C-586 3. Quick Chemical Test, ASTM C 289 4. Mortar Bar Test, ASTM C 227 5. Testing of Concrete Prisms, ASTM C-157
The conclusion of the testing program was that A7-NC has a high reactivity potential and that its use should be restricted to concretes with cements having an alkali content of 0.4% or less.
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Virginia Aggregates: A8-VA and B4-VA Coarse and a fine aggregate samples from a Virginia aggregate were made available for investigating. The following is a presentation of their reported properties. Petrographic Analysis: A8-VA “The sample generally consisted of particles of Quartz, Quartzite, Granitic rock fragments, Siltstone and Sandstone. A general description of the particles is as follows: 1. Quartz: The particles display a massive crystal structure with low porosity and
permeability. They were generally rounded aggregates with smooth surfaces. The aggregate was hard and dense. Some particles had fractures that did not penetrate completely through. Particle colors included milky white, smokey brown and clear (transparent).
2. Quartzite: This aggregate displayed a granoblastic (equigranular) texture. The particles were composed of medium to fine grain sand cemented tightly in a silica matrix. Particle colors were rose, light brown and reddish brown.
3. Granite Rock: Particle shapes range from angular to rounded. Mineral constituents included quartz, mica, hornblend, and feldspar. The aggregate has good intergranular bonds and is considered to be sound and durable. Only minor evidence of weathering was noted on the surface of some particles. Particle color was generally grey.
4. Sandstone: These aggregate particles were mainly composed of angular to subrounded quartz minerals along with other fine grain ferruginous minerals. The aggregate displayed good intergranular bonds and was generally free of fractures. Particle colors were predominately brown with some gray particles.
5. Siltstone: These aggregate particles display a compact crystal structure. The grain size is approximately 1/16 to 1/256 mm (medium to very fine silt). Particle colors were brown, black, and yellow. Intergranular bonds were considered to be good.
No external coatings were noted on the aggregate. The aggregate is considered to be sound and durable (Petrographic report supplied by aggregate producer, 1999).”
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Composition of Aggregate Sample (A8-VA) In
whole sample
Constituents 1” ¾” ½” 3/8” #4 Cdt 1 Cdt 2 TotalsSandstone 25 42 22 28 40 31 - 31 Quartz Rock 44 43 49 52 39 45 - 45 Quartzite 25 12 16 11 13 14 - 14 Granite Rock Fragments 6 1 7 6 2 4 1 5 Siltstone 0 2 6 3 6 4 - 4 Totals 100 100 100 100 100 - - 99 Average (Cdt 1) 98 - Average (Cdt 2) - 1 Cdt 1: Rock particles considered to be fresh, dense, and in good physical condition. Cdt 2: Rock particles considered sound and durable with minor weathering. Petrographic Analysis: B4-VA The sample generally consisted of particles of quartz, quartzite, granitic rock fragments, siltstone, sandstone, and natural mineral fragments. A general description of the particles is as follows: 1. Quartz: The quartz is the most abundant of all constituents contained in this
sample. Particle shapes range from angular to sub-rounded. The particle colors were milky white, brick red, rose or pink, and clear.
2. Quartzite: This aggregate displayed a granoblastic (equigranular) texture. The aggregate was composed of tightly interlocked grains of quartz. In some particles, feldspar is evident in the matrix. The quartzite is of the sedimentary type of formation. Particle colors were white, grey, reddish, and clear.
3. Granite Rock: Particle shapes range from angular to rounded. Mineral constituents included quartz, mica, hornblende, and fine grained pink feldspar. The aggregate has good intergranular bonds. Particle colors were generally grey and shades of pink and red.
4. Sandstone: The sandstone particles were mainly composed of fine grained and well-sorted quartz. Particle shape ranged from sub-rounded to rounded which were cemented in a silica matrix. Particle colors were variable between red, brown, yellow, white, and grey.
5. Siltstone: Thee aggregate particles displayed a compact crystal structure. The grain size is approximately 1/16 to 1/256 mm (medium to very fine silt). Particle colors were brown, black, and yellow.
6. Minerals: These particles were composed of natural minerals which became detached from the parent rock. Components included hornblende, feldspar, and various other ferruginous minerals.
No external coatings were noted on the aggregate. The aggregate is considered to be sound and durable.
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Composition of Aggregate Sample (B4-VA) In whole
sample
Constituents #4 #8 #16 #30 #50 #100 Cdt 1 Cdt 2 TotalsSandstone 40 40 62 74 82 82 67 - 67 Quartz Rock 8 9 13 6 6 5 7 - 7 Quartzite 5 6 4 2 2 1 3 - 3 Granite Rock Fragments
20 22 11 4 trace trace 5 1 6
Siltstone 27 23 8 11 7 4 9 1 10 Mineral Fragments trace trace 2 3 3 8 3 - 3 Totals 100 100 100 100 100 100 - - 96 Average (Cdt 1) 94 - Average (Cdt 2) - 2 Cdt 1: Rock particles considered to be fresh, dense, and in good physical condition. Cdt 2: Rock particles considered sound and durable with minor weathering. Field Performance: A8-VA and B4-VA It was reported that these aggregates “have been on the list of approved materials for the Virginia Department of Transportation for many years.” Many fairly new concrete structures incorporate these aggregates. It was also reported that an ASR mitigation alternative is required in all used mixtures. About 10 to 15 years ago, the Virginia DOT has required the use of a pozzolan in all their portland cement concrete mixtures, namely, 20-25% Class F fly ash, 5% silica fume, and 35-50% slag. All these alternatives at these levels have been used to mitigate ASR. NEBRASKA AGGREGATES: A9-NE Samples of an aggregate composed of mixed sand and gravel and heavily used in the Nebraska area were made available for this ASR study. The following are some of the documentation that was provided with the aggregate. Petrographic Analysis: A9-NE The following is a summary of a petrographic analysis performed on A9-NE: 1. The aggregate sample is partially crushed natural gravel comprising primarily of
siliceous rocks and other fragments as indicated in the following table. 2. Major constituents of the aggregate sample include pink granite, orthoquartzite,
metaquartzite, chert, metachert and allogenic quartz. Allogenic indicates rock or mineral constituents were derived from pre-existing rocks (e.g. granite) and transported to their present depositional site. This allogenic quartz becomes the major constituents of the size fraction passing the No. 30 sieve (less than 0.6mm).
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3. Minor constituents of the aggregate sample include sandstone, siltstone/claystone, and miscellaneous volcanic rocks, igneous rocks and metamorphic rocks.
4. The crypto-to-micro-crystalline textured silica as exhibited by orthoquartzite/metaquartzite and chert/metachert as well as the microgranular to fine granular silica as exhibited by the allogenic quartz are prone to be alkali-reactive when used in concrete containing high-alkali cement paste and in concrete exposed to very moist conditions.
5. Most aggregate partcles are hard, dense, free of coatings, and are sub-angular to well-rounded.They appear to be frost resistant and should bond well to cement paste.
6. Test methods and petrographic description of the aggregate sample are given in the following sections of this report.
Pink granite is the most abundant constituent of the sand-gravel aggregate sample
larger than the No.30 sieve (0.6mm). It is pink-colored, coarse-grained, hypidiomorphic-granular, plutonic rock, containing quartz as the most essential mineral. Accessory minerals include plagioclase feldspar and some mafic minerals such as hornblende, mica and little iron oxide.
Orthoquartize and metaquartizite are the second most abundant constituent of the aggregate sample particularly in the coarse size fractions (retained on No.16 mesh sieve). Orthoquartzite is a sandstone comprising primarily of quartz and minor amount of feldspar, limonite, and other mafic minerals. It exhibits crypto-crystalline to micro-crystalline texture, well-sorted, well-rounded to sub-rounded quartz sand grains cemented in a siliceous matrix. Metaquartzite is compositionally similar to orthoquartzite except that metaquartzite has undergone metamorphism resulting in strain of quartz sand grains and cement. Metamorphism has imparted the appearance of a mosaic of interlocking quartz sand grains in metaquartzite particles.
The stained quartz sand grains exhibit undulatory extinction in thin sections. The quartzites (ortho and meta) are fine-to-coarse-grained, hard and dense, tan to translucent to buff. Chert and metachert are also one of the major constituents of the sand-gravel aggregate sample. They are dull to semi-vitreous, microcrystalline sedimentary rock constitute dominantly of interlocking minute crystals of quartz. Impurities include small amount of chalcedony, mica, limonite, calcite and other minerals. The varieties of chert present in the sample are: (a) light-colored (light brown, tan, and buff) amorphous silica (opaline), (b) dark brown to black metachert, and (c) light to dark-colored porous chert.The chert/metachert are known to be alkali-reactive when used in concrete especially the crypto-and-micro-crystalline and porous varieties. Quartz (silica) is also a major constituent of the aggregate sample particularly those size fractions passing the No. 30 sieve (0.6mm). It is allogenic, indicating it was formed or generated elsewhere, usually at a distant place specifically from rock
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constituents and minerals derived from pre-existing rocks (i.e granite) and transported to their present depositional site. They are microgranular to fine granular, crystalline to crypto-crystalline silica. They exhibit vitreous to greasy luster, conchoidal fracture and an absence of cleavage. The crypto-crystalline variety includes chalcedony, agate, and opal. These kinds of minerals when used in concrete containing high-alkali cement pastes are prone to be alkali-reactive. Sandstone is a minor constituent (less than 5%) of the aggregate sample. The sandstone particles are composed of fine to coarse sand grains of quartz, feldspar, calcite , ironstone and other dark-colored minerals. The sand grains are sub-angular to well rounded and cemented primarily by secondary quartz or detrital chert grains. Sandstone grades into siltstone and claystone as particle size of the sand grains decreases. Therefore, composition of the siltstones and claystones are similar to the sandstones. The sandstone, siltstone, and claystone particles are tan to brown, generally moderately hard to hard, frequently dense to less commonly porous. Other minor constituents of the aggregate sample include mica, volcanic and igneos rocks and metamorphic rocks, schist, phyllite, hornfels) categorized as miscellaneous group. These particles are generally dark-colored, moderately hard and dense except the lineated particles.
Petrographic Composition for A9-NE Composition of Fractions Retained on Sieves
3/8” No.4 No.8 No.16 No.30 No.50 No.100 No.200 <0.075mm Constituents % % % % % % % % % Pink Granite 46.5 46.9 46.2 41.1 33.7 9.8 6.2 4.5 2 Orthoquartzite & Metaquartzite
27.2 35.1 30 21.8 18.7 5.9 3.7 1.9 1
Chert & Metachert
12.2 4.3 10.0 15.1 11.3 4.6 3.1 0.6 Trace
Sandstone 1.8 3.3 2.7 1.0 1.9 0 0 0 Trace Siltstone & Claystone
0.9 1.4 1.5 0.7 0.6 0 0 0 Trace
Quartz (Silica)
7.0 7.6 7.7 20.0 31.9 76.5 82.0 87.9 92.0
Miscllaneous 4.4 1.4 1.9 0.3 1.9 3.2 5.0 5.1 5.0 Total 100 100 100 100 100 100 100 100 100
Field Performance: A9-NE It was reported that A9-NE “is representative of that used in much of the pavement when Interstate I-80 was first constructed through Nebraska. The aggregate is still being used but limestone is added to mitigate reactivity. When I-80 was first constructed, about one-half was built with a mix that used only A9-NE.”
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These sections of I-80 were heavily damaged due to ASR as can be seen in the following figures.
Alkali-Silica Reaction Damage in Sections of the I-80 in Nebraska
More Alkali-Silica Reaction Damage in Sections of I-80 in Nebraska
Laboratory Performance: A9-NE Available laboratory test results indicate that the sand-gravel aggregate A9-NE complies with the majority of requirements outlined in ASTM C 33. However, the aggregate exhibit signs of being reactive with alkali and can cause potentially harmful expansions. Reported results are as follows:
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Reported ASTM C 227 Results for A9-NE Test Results ASTM C 33 Limits Comment Expansion at 1 month 0.005% Expansion at 2 months 0.016% Expansion at 3 months 0.021% 0.05% Expansion at 4 months 0.031% Expansion at 5 months 0.031% Expansion at 6 months 0.031% 0.10% Non-Reactive
Note 1: Alkali content of laboratory cement = 1.01% Na2Oequiv. Note 2: Expansion is generally considered to be excessive if it exceeds
0.05% at 3 months or 0.10 at 6 months. Expansions greater than 0.05% at 3 months should not be considered excessive where 6 month expansion remains below 0.10% (Appendix X1.1.3 ASTM C 33) Reported ASTM C 1260 Resultsfor A9-NE
Test Results Comment Coarse Aggregate Expansion at 10 days
0.058% Innocuous
Fine Aggregate Expansion at 10 days
0.290% Reactive
Aggregate Combination: 70% sand 30% Coarse Expansion at 10 days
0.174% Reactive
Note 1: W/C = 0.50 Note 2: Expansion greater than 0.10% at 10 days is considered reactive MARYLAND AGGREGATE: B1-MD AND B2-MD Coarse and fine aggregate samples from the Maryland area where made available for this ASR investigation. Properties of the aggregate are as follows. Petrographic Analysis: B1-MD AND B2-MD The following table includes a summary of a petrographic examination performed on the aggregate.
Results of Petrographic Analysis on B1-MD and B2-MD
Mineral Species Crystal/Grain Size % of Composition Comments Chlorite Feldspar Fine-Grained Together:
80 – 90 Finely Intergrown
Matted Groundmass Quartz Minor Chlorite 0.3 mm 10-20 Some “Floating
Crystals”
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Field Performance: B1-MD and B2-MD The aggregate has been used extensively in Delaware. It is well known as a slowly reactive aggregate with ASTM C 1260 expansions between 0.10% and 0.15%. It has shown to be reactive in very old structures that do not have any pozzolan or any other ASR mitigating method. However, since its identification as a slowly reactive aggregate, it has been successfully used with appropriate ASR mitigating measures. Laboratory Performance: B1-MD and B2-MD Reported C 1260 date back to 1991. A type I cement was used in combination with a water-cement ratio of 0.50. Results are listed in the following able.
Reported ASTM C 1260 Results for B1-MD and B2-MD Bar No. 4-Days 7-Days 11-Days 14-Days
1 0.041 0.062 0.086 0.112 2 0.031 0.058 0.080 0.105
Average 0.036 0.060 0.083 0.11
SOUTH DAKOTA AGGREGATES: C1-SD AND C2-SD Petrographic Analysis: C1-SD and C2-SD 1. The rock is a crushed, equi-dimentional, hand sample (2 to 3 inch) sized massive,
pink quartzite. 2. The material exhibits well-developed quartz overgrowths of the individual quartz
grains. The pink to purplish color is derived from finely disseminated iron oxide which coats the original, well-rounded quartz grains as a thin film.
Reported Optical Properties and Mineralogy: C1-SD
Minerals Vol. Color Relief Other Quartz 98% Colorless Low Quartz, quartzite sand, and cement;
undulatory extinction in most grains, unit extinction in few
Pyroxene <1 Green, yellow, Pink pleoch
m-high Diopside, pyroxene cleavage and parallel extinction
Iron Oxide <1 Red Medium Finely disseminated, coating on original sand grains
Heavy Minerals
<0.1 Browns, greens
Medium to high
Various, zircon, epidote and others
Sericite <0.1 Colorless m-low At some grain boundaries Clays <0.1 Colorless low Clay “books" 3. The aggregate has a lengthy service history of good performance as concrete
aggregate and in other construction applications.
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Field Performance: C1-SD and C2-SD In old structures, namely dams, the aggregate was found to be alkali-silica
reactive. Its reactivity is attributed to the existence of strained quartz in the aggregate, which makes it a slowly reactive aggregate that cannot be detected using the existing C 227 procedures (Buck 1983). ILLINOIS AGGREGATE: D1-IL AND D2-IL
An innocuous fine and coarse aggregate form the same source and representative of aggregates used in the Illinois area were used throughout the study. Aggregate properties are as follows: Petrographic Analysis: D1-IL and D2-IL
The aggregate is hard, massive, structureless to highly coralliferous, finely crystalline dolomite. It contains numerous fossils (corals, trilobites, crinoids, cephalopods, brachiopods, gastropods, sponges). It also contains very minor amounts of clay minerals, detrial quartz, authigenic silica and traces of carbonaceous matter (tar-like hydrocarbons) and iron-oxide compounds. It does not contain mineral assemblages that are prone to alkali-aggregate reactions.
The quarried stones have been used for many years as good, chert-free concrete aggregates, excellent aggregate source for high strength concrete, raw materials for the manufacture of high-quality lime, source for ripraps, blacktop chips and mineral fillers. IOWA AGGREGATE: E2-IA Field Performance: E2-IA
The aggregate is a glacial deposit that is quite shaley and has been successfully used in concrete structures with no evidence of ASR damage. The sand aggregate was used on a 1961 paving project on U.S. Highway 18. The mix design used was an IDOT C-3 as follows for volume: 1. Cement 0.114172 2. Sand (E2-IA) 0.297395 3. Coarse 0.364593 4. Water 0.457 lb per lb 5. Cement alkali content > 0.9% Na2Oequiv. 6. Air 6.0%
The latest inspection showed that the pavement has small pop outs but no ASR evidence. Laboratory Performance: E2-IA
Reported C 1260 results show that E2-IA had a 14-day expansion of 0.33% and was classified as reactive. The average of three bars was used to get the final expansion result.
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Reported C 1293 results are listed below. The test was performed by both the IaDOT and LaFarge Corporation. Both tests resulted in 1-year concrete-prism expansions lower than 0.04% (around 0.020%).
Reported C 1293 Results for E2-IA Testing Agency
Expansion 1-month
Expansion3-months
Expansion18-week
Expansion6-month
Expansion 9-month
Expansion12-months
IaDOT 0.017 0.019 0.019 0.022 0.026 0.027 Lafarge 0.012 0.018 0.018 0.019 0.023 0.023
NEVADA AGGREGATES: E3-NV AND E4-NV Petrographic Information: E3-NV AND E4-NV
E3,E4-NV is a glassy rhyolite that comes from Rilite aggregates. The rhyolite is a young, volcanic rock. It is an amorphous siliceous rock with more than 65% SiO2. Physically, the rhyolite consists of 80 to 90% glass and 5 to 10% voids. The minerals present, which make up from 5 to 10% of the total aggregate, are phenocrysts within the glass matrix and consist of (in order of abundance) quartz, alkali-feldspar, plagioclase, and biotite. The rhyolite is light to dark grey in color and flow-banded. It is an angular aggregate with 100% fractured faces. The aggregate is considered to be potentially deleterious. Field and Laboratory Performance
Even though the aggregate is considered deleterious when examined petrographically, it has been used successfully in concrete structures. Petrographic examinations of cores taken from an 11-year-old concrete slab that utilized E4-NV, show no evidence of ASR. This is explained by the following points that are quoted from the petrographic examination report of the cores: 1. E3,4-NV is and always has been used only with a low alkali cement (<0.6% by
weight alkalis). 2. When Rilite is used in concrete, it composes both the coarse and fine fractions of
the aggregate. It has been shown that a deleterious degree of alkali-aggregate reaction will not occur if the reactive forms of siliceous material are sufficiently abundant in the concrete to consume available alkalies in production of alkali-silica combinations of very low alkali to silica, so that they lack the capacity to develop swelling or osmotic pressure by absorption of water.
INDIANA AGGREGATE: E6-IN This aggregate has only been used either with a low alkali cement or with an ASR
mitigating method. As a results, the aggregate has been successfully used for years.
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There are no records of whether this aggregate can be used with high alkali cement and no ASR mitigating method and not show deleterious expansions. SUMMARY
The following table is a summary of the available documentation about the alkali-silica reactive of aggregates investigated in this study (Table 5.2).
Summary of Aggregates Contituents and Performance
Aggregate
Petrographic Analysis
ClassificationField
Performance Mineral Materials A(1,2)-WY Reactive Reactive Rhyolite A(3,2)-ID Reactive Reactive Quartzite, sandstone, limestone,
andesite, rhyolite A(5,6)-NM Reactive Reactive Rhyolite, andesite
A7-NC Reactive Reactive Argillite A8-VA Innocuous N.R. Quartz, quartzite, granitic rock
fragments, siltstone, sandstone, and natural mineral fragments
A9-NE Reactive Reactive Pink granite, orthoquartzite, metaquartzite, chert, metachert and
allogenic quartz A10-PA Reactive N.R.
B(1,2)-MD Reactive Reactive Chlorite feldspar, quartz, and chlorite B4-VA Innocuous N.R. Quartz, quartzite, granitic rock
fragments, siltstone, sandstone, and natural mineral fragments
C(1,2)-SD Reactive Reactive Pink quartzite, pyroxene, iron oxide, sericite, Clay
D(1,2)-IL Innocuous Good with high-alkali
cement
Dolomite
E2-Ia Innocuous Good with high-alkali
cement
Glacial deposit, shale
E(3,4)-NV Reactive Good with mitigation
Glassy rhyolite
E6-IN Innocuous Good with high alkali
cement
N.R.
E(7,8)-NM Reactive Good with mitigation
Rhyolite, andesite
N.R. = No Record
Appendix E
Petrographic Examination of Mortar Bars After Being Tested In Accordance
with ASTM C 1260
Introduction Thin sections from six mortar bars tested according to ASTM C 1260 were
petrographically examined for signs of ASR. Two bars contained highly reactive aggregates from Category A (A4-ID and A2-WY), two contained slowly reactive aggregates (C2-SD and B4-VA), and two contained aggregates form Category E (E2-IA and E6-IN). The two category E aggregates were determined to be innocuous in the field and using C 1293; however, showed reactive C 1260 expansions. The following is a discussion of the findings. Category A Aggregates (A4-ID and A2-WY)
Representative pictures of damage found in mortar bars made with these aggregates are shown in Figures E.1 and E.2. Evidence of ASR was not easily detected. In a few locations aggregates had internal damage and had a thin rim around the outside of aggregate particle, as seen in Figure E.1. However, even in these instances the evidence did not overwhelmingly indicate the presence of ASR.
Figure E.1: A piece of aggregate showing internal cracking and a very thin
black rim around the outside of the aggregate
Figure E.2: Cracking propagating from a piece of aggregate into an air void
indicating that there might be distress caused by aggregate expansion
Slowly Reactive Aggregates (C2-SD and B4-VA)
Thin sections taken from mortar bars containing these aggregates did not show any signs of aggregate distress. All examined aggregate particles were sound with no internal cracking and no presence of the outside rim characterizing the ASR gel. Signs of ASR damage could not be identified from examining the thin sections taken. Category E Aggregates (E2-IA and E6-IN) As mentioned earlier these aggregates were determined to be innocuous in field applications and according to C 1293; however, they tested reactive using C 1260. Figures E.3 and E.4 show typical distress found in thin sections taken from mortar bars containing these aggregates. Figure E.3 indicates that the distress was located in the paste and cracks were propagating away from an aggregate particle. No rims were identified around aggregate particles. Figure E.4 might be representative of DEF; however, it is not very clear. Examining the thin sections obtained, it was not possible to determine the cause of the excessive expansion and damage caused to the mortar bars containing these aggregates.
Figure E.3: Cracks in the paste propagating away from an aggregate particle
Figure E.4: Possible presence of DEF
Final Remarks Examining the different thin sections, it was not possible to determine the definite cause of expansions in the mortar bars. Even though the highly reactive aggregates showed some signs of aggregate distress, the evidence was not very conclusive. No evidence of ASR was found in slowly reactive aggregates and in Category E aggregates.
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