Field-Focused Superpave Validation

Field-Focused SuperpaveValidation

FINAL REPORT

November 2008

By Mansour Solaimanian and Scott M. MilanderThe Thomas D. LarsonPennsylvania Transportation Institute

COMMONWEALTH OF PENNSYLVANIADEPARTMENT OF TRANSPORTATION

CONTRACT # 510401PROJECT # 009

Technical Documentation Page

Form DOT F 1700.7 (8-72) Reproduction of completed page authorized

1. Report No. FHWA-PA-2008-009-510401-009

2. Government Accession No.

3. Recipient’s Catalog No.

5. Report Date August 2008

4. Title and Subtitle Field-Focused Superpave Validation

6. Performing Organization Code

7. Author(s) Mansour Solaimanian, Scott M. Milander

8. Performing Organization Report No. LTI 2009-03 10. Work Unit No. (TRAIS)

9. Performing Organization Name and Address The Thomas D. Larson Pennsylvania Transportation Institute Transportation Research Building The Pennsylvania State University University Park, PA 16802-4710

11. Contract or Grant No. 510401, Work Order No. 9 13. Type of Report and Period Covered Final Report 7/10/2006 – 6/30/2008

12. Sponsoring Agency Name and Address Pennsylvania Department of Transportation Bureau of Planning and Research Commonwealth Keystone Building 400 North Street, 6th Floor Harrisburg, PA 17120-0064

Mid-Atlantic Universities Transportation Center The Pennsylvania State University Transportation Research Building University Park, PA 16801-4710

14. Sponsoring Agency Code

15. Supplementary Notes COTR: Mr. Tim Ramirez 16. Abstract The Superpave design system came into existence in the mid-1990s. Many pavements have been constructed with Superpave designed hot mix asphalt (HMA). Today, this technology is well established in many states. It has been over a decade since the Commonwealth of Pennsylvania began using this system for designing HMA. There has been general satisfaction with the pavements constructed with this mix, and anecdotal evidence suggests that Superpave pavements are performing well in Pennsylvania; however, within the last several years, there has been concern raised in regard to the durability of some Superpave mixes. Some have reported these problems as a result of insufficient binder content in the mix. This issue has been the driving force for several states to take measures to increase the binder content in the mix. There has also been a move by some to increase the minimum required VMA to allow more space within the aggregate structure for asphalt and therefore provide a higher binder content mix at a specified design air void level. The Pennsylvania Department of Transportation is now specifying 1/2 percent higher VMA for all aggregate-size gradations than is specified in AASHTO M323. As the Superpave design criteria are evolving, it is worth looking back into the performance of the pavements constructed with Superpave mixes. The research findings presented in this report are the result of such effort, evaluating the long-term performance of Superpave-designed mixes. 17. Key Words SuperPave, asphalt, asphalt binder, rutting, fatigue, thermal cracking, pavement performance

18. Distribution Statement No restrictions. This document is available from the National Technical Information Service, Springfield, VA 22161

19. Security Classif. (of this report) Unclassified

20. Security Classif. (of this page) Unclassified

21. No. of Pages 138

22. Price

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TABLE OF CONTENTS

LIST OF FIGURES ...................................................................................................................... vii

LIST OF TABLES.......................................................................................................................... x

EXECUTIVE SUMMARY.................................................................................... xiii

CHAPTER ONE ........................................................................................................1

INTRODUCTION......................................................................................................1

BACKGROUND .............................................................................................................................1

Objectives ........................................................................................................................................2

Research Approach and Scope of Work ..........................................................................................3

CHAPTER TWO .......................................................................................................4

SCOPE OF FIELD AND LABORATORY INVESTIGATION...............................4

Pavement Condition Survey ............................................................................................................4

Status of Available Data for Projects Considered Under WO-43 .................................................. 4

Inventory of Materials .................................................................................................................... 5

Projects Selected for Performance Evaluation................................................................................ 6

Scope of Performance Evaluation................................................................................................... 7

Detailed Pavement Evaluation Procedure....................................................................................... 8

Transverse Profiles (Rutting).......................................................................................................... 9

Criterion to Determine Rut Depth ................................................................................................ 10

Field Seismic Modulus Testing .................................................................................................... 11

Laboratory Investigation................................................................................................................15

Preparation of Cores ..................................................................................................................... 16

Indirect Tensile Creep and Strength Testing ................................................................................ 16

Resilient Modulus Testing ............................................................................................................ 17

Asphalt-Aggregate Extraction ...................................................................................................... 20

Binder Recovery ........................................................................................................................... 21

CHAPTER THREE..................................................................................................23

ANALYSIS, INTERPRETATION, AND FINDINGS ...........................................23

Section 1: Results of Pavement Condition Evaluation .................................................................23

Evaluation Results for SR 15 Northbound, Lycoming County .................................................... 23

vi

Evaluation Results for Highway SR 11, Snyder County .............................................................. 32

Evaluation Results for SR 153-Section 225, Clearfield County....................................................37

Evaluation Results for I-80, EastBound, Centre County ...............................................................44

Evaluation Results for SR 522, SouthBound – Huntingdon County.............................................52

Rutting........................................................................................................................................... 52

Section 2: Results from Laboratory Investigation ........................................................................55

Low Temperature Creep and Strength Testing Results ................................................................ 56

Results from Resilient Modulus Testing ...................................................................................... 77

Results form PSPA Tests .............................................................................................................. 77

Analysis of Rutting Data............................................................................................................... 80

Investigation of Aging in Superpave Binders............................................................................... 83

CHAPTER FOUR....................................................................................................88

SUMMARY AND CONCLUSIONS ......................................................................88

References......................................................................................................................................91

APPENDIX A: Inventory of Data and Materials from PennDOT WO-43 Project ……… A-1

APPENDIX B: Pictures of Cores Obtained Under WO-9 ……………………………….. B-1

APPENDIX C: Scope of Pavement Condition Survey …………………………………… C-1

APPENDIX D: Aggregate Gradations Obtained from WO-9 Cores ……………………… D-1

vii

LIST OF FIGURES

Figure 1 Transverse profiling using the digital depth meter........................................................ 10

Figure 2 Approach used in this project to determine rut depth. .................................................. 11

Figure 3 Portable Seismic Pavement Analyzer (PSPA) .............................................................. 13

Figure 4 Sample PSPA data......................................................................................................... 14

Figure 5 Compression testing of the cores in diametral direction to determine indirect

tensile creep and strength...................................................................................................... 17

Figure 6 Load cycle (kN) vs. time(s). .......................................................................................... 19

Figure 7 Horizontal deformation (mm) vs. time(s)...................................................................... 19

Figure 8 Vertical deformation (mm) vs. time(s). ......................................................................... 20

Figure 9 Transverse profile at Lycoming SR 15- northbound, ID2 section. ............................... 25

Figure 10 Transverse profile at Lycoming SR 15- northbound, Superpave section.................... 26

Figure 11 Transverse profile at Lycoming SR 15- southbound, Superpave overlay section. ..... 26

Figure 12 Transverse profile at Lycoming SR 15- southbound, Superpave full section............. 27

Figure 13 Pictures of Lycoming SR 15 pavement – ID2, northbound. ....................................... 29

Figure 14 Pictures from Lycoming SR 15, Superpave full depth, northbound. .......................... 30

Figure 15 Pictures of Lycoming SR 15 pavement, Superpave over concrete, southbound......... 31

Figure 16 Transverse profile at Snyder SR 11- southbound passing lane. .................................. 33

Figure 17 Transverse profile at Snyder SR 11- southbound travel lane...................................... 33

Figure 18 Transverse profile at Snyder SR 11- southbound travel lane...................................... 34

Figure 19 Pictures of Snyder SR 11 pavement, southbound. ...................................................... 36

Figure 20 Transverse profile at Clearfield SR 153- northbound, PG 64-22 section. .................. 39

Figure 21 Transverse profile at Clearfield SR 153- northbound, PG 64-28 section. .................. 39

Figure 22 Pictures of Clearfield SR 153 pavement, PG 64-22 section........................................ 42

Figure 23 Pictures of Clearfield SR 153 pavement, PG 64-28 section........................................ 43

Figure 24 Transverse profile at Centre I-80, eastbound, MP 167.0 to MP 167.5........................ 46

Figure 25 Transverse profile at Centre I-80, eastbound, MP 167.5 to MP 168........................... 46


Figure 27 Transverse profile at Centre I-80, eastbound, MP 168.5 to MP 169........................... 47

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Figure 29 Pictures of Centre I-80 pavement. ............................................................................... 50

Figure 30 Pictures of Centre I-80 pavement. ............................................................................... 51

Figure 31 Transverse profile at Huntingdon SR 522, southbound. ............................................. 53

Figure 32 Pictures of Huntingdon SR 522 pavement. ................................................................. 54

Figure 33 Creep Compliance versus reduced time for ID-2 and Superpave Sections

at Lycoming SR 153. ............................................................................................................ 57

Figure 34 Creep compliance (1/MPa) vs. time(s) for CR 64-22. ............................................... 59

Figure 35 Creep compliance (1/MPa) vs. reduced time(s) for CR 64-22.................................... 59

Figure 36 Log shift factors vs. temp for CR 64-28...................................................................... 60

Figure 37 Creep compliance (1/MPa) vs. time(s) for CR 64-28. ................................................ 60

Figure 38 Creep compliance (1/MPa) vs. reduced time(s) for CR 64-28.................................... 61

Figure 39 Log shift factors vs. temp for CR 64-28...................................................................... 61

Figure 40 Comparison of master curves of both sites on log-log domain. .................................. 62

Figure 41 Comparison of shift factor curves for both sites. ........................................................ 63

Figure 42 Strength test results for CR 64-22. .............................................................................. 64

Figure 43 Strength test results for CR 64-28. .............................................................................. 64

Figure 44 Creep compliance vs. time – Huntingdon. .................................................................. 66

Figure 45 Creep compliance vs. reduced time – Huntingdon...................................................... 66

Figure 46 Log shift factor curve – Huntington. ........................................................................... 67

Figure 47 Indirect tensile strength test results– Huntington SR 522. .......................................... 68

Figure 48 Creep compliance vs. time for cores 10, 11, and 12 between MP 169 and

169.5 (I-80 Centre). .............................................................................................................. 70

Figure 49 Creep compliance vs. reduced time for cores between MP 169 and

169.5 (I-80 Centre). .............................................................................................................. 70

Figure 50 Log shift factor vs. temp for cores 10, 11, and 12....................................................... 71

Figure 51 Creep compliance vs. time for cores 6 and 7 between MP 168 and

168.5 (I-80 Centre). .............................................................................................................. 71

Figure 52 Creep compliance vs. reduced time for cores between MP 168 and 168.5................. 72

Figure 53 Log shift factor vs. temp for cores 6 and 7.................................................................. 73

Figure 54 Comparison of master curves for I-80......................................................................... 73

ix

Figure 55 Comparison of shift factors (I-80)............................................................................... 74

Figure 56 Strength values for cores between MP 169 and 169.5. ............................................... 75

Figure 57 Strength values for cores between MP 168 and 168.5. ............................................... 75

Figure 58 Measure rut depth at different sites. ............................................................................ 81

Figure 59 Rut Depth versus CHRST permanent shear strain of the wearing layer. .................... 83

Figure 60 Binder modulus for Clearfield SR 153-PG 64-28 from PAV simulation

and field cores. ...................................................................................................................... 85

Figure 61 Binder modulus for Clearfield SR 153-PAV simulation: PG 64-28 versus

PG 64-28. .............................................................................................................................. 85

Figure 62 Binder modulus for Clearfield SR 153 field cores: PG 64-28 versus PG 64-28........ 86

Figure 63 Binder modulus for Huntingdon SR 522 PAV simulation versus field cores............. 86

x

LIST OF TABLES

Table 1 Projects Selected for Condition Survey under Task 2. ..................................................... 6

Table 2 Projects Selected for Coring. ............................................................................................ 7

Table 3 Pavement Sections Surveyed or Cored Under WO-9....................................................... 8

Table 4 Tests Conducted on the Cores for WO-9 Project. .......................................................... 15

Table 5 Tests Conducted on the Asphalt Binder for WO-9 Project. ........................................... 15

Table 6 Measured Rut Depth for Lycoming SR 15 – Northbound.............................................. 27

Table 7 Measured Rut Depth for Lycoming SR 15 – Southbound.............................................. 28

Table 8 Measured Rut Depth for Snyder SR 11 – Southbound................................................... 34

Table 9 Measured Rut Depth for Snyder SR 11- Southbound. ................................................... 35

Table 10 Measured Rut Depth for Clearfield SR 153-Northbound............................................. 40

Table 11 Measured Rut Depth for Centre I-80, Eastbound. ........................................................ 48



Table 14 Measured Rut Depth for Huntingdon SR 522, Southbound. ........................................ 53

Table 15 Thicknesses and Specific Gravities for Cores Tested Under WO-9............................. 55

Table 16 Comparison of Design and Measured Gmm for the Wearing Course .......................... 56

Table 17 SR 153 Cores Selected for IDT. ................................................................................... 58

Table 18 Log Shift Factors for Both Sections at SR 153............................................................. 63

Table 19 Sigmoidal Coefficients for Both Sections at SR 153.................................................... 63

Table 20 Huntingdon SR 522 Cores Selected for IDT. ............................................................... 65

Table 21 Sigmoidal Coefficients – Huntington. .......................................................................... 67

Table 22 Shift Factors – Huntington............................................................................................ 67

Table 23 Strength Test – Huntington........................................................................................... 68

Table 24 Details of Cores Selected for IDT from Centre I-80. ................................................... 69

Table 25 Strength Values for All Cores in I-80........................................................................... 76

Table 26 Log Shift Factors for All Cores in I-80. ....................................................................... 76

Table 27 Sigmoidal Coefficients for All Cores in I-80. .............................................................. 76

Table 28 Results of Resilient Modulus Test for Centre I-80....................................................... 77

xi

Table 29 Results of Resilient Modulus Test for Huntingdon SR 522. ........................................ 77

Table 30 Results of PSPA Testing at Huntingdon SR 522.......................................................... 79

Table 31 Shear Test Results for Cored Projects and Correspondence with Measured

Field Rut Depth..................................................................................................................... 82

Table 32 Comparing Modulus of Binder from PAV Simulation with That of Field Cores. ....... 84

xii

ACKNOWLEDGEMENTS The work upon which this report is based is the result of two years of field and laboratory investigation. Financial support for this project was provided by the Pennsylvania Department of Transportation (PennDOT) and the Mid-Atlantic Universities Transportation Center (MAUTC). This support is greatly appreciated. Ms. Michelle Tarquino and Ms. Lisa Karavage of the PennDOT Bureau of Research and Planning served as project managers. Their guidance is truly appreciated. Mr. Tim Ramirez of the PennDOT Bureau of Construction and Materials served as technical liaison with PennDOT. His counsel and directions were great and highly needed. Also recognized is the invaluable help provided by Mr. Dean Maurer of the Bureau of Construction and Materials. Mr. Maurer was instrumental in helping the research team with all of the site visits and identifying the projects to be investigated. The authors are also grateful to Ms. Janice Dauber of Penn State, who served as the research coordinator and oversaw the MAUTC portion of the project. Mr. Michael Casper and Ms. Mara Poorman provided support with editing and formatting the report and their assistance is appreciated. Penn State graduate students Qinwu Xu and Laxmikanth Premkumar provided valuable assistance with the laboratory testing. Finally, great appreciation is extended to all PennDOT personnel who assisted the research team with field visits, traffic control, and coring the pavements of the visited sites.

This work was sponsored by the Pennsylvania Department of Transportation and the U.S. Department of Transportation, Federal Highway Administration. The contents of this report reflect the views of the authors, who are responsible for the facts and the accuracy of the data presented herein. The contents do not necessarily reflect the official views or policies of either the Federal Highway Administration, U.S. Department of Transportation, or the Commonwealth of Pennsylvania at the time of publication. This report does not constitute a standard, specification, or regulation.

xiii

EXECUTIVE SUMMARY

At the beginning of the implementation of the Superpave system in the Commonwealth of

Pennsylvania, a series of projects were selected for detailed study to validate and determine the

effectiveness of this system in designing asphalt concrete mixtures. Consequently, a research project

titled “Superpave Validation Studies” was sponsored by Pennsylvania Department of Transportation

(PennDOT) in 1999. That study, known as Work Order 43, was conducted by the Northeast Center

of Excellence for Pavement Technology (NECEPT) at The Thomas D. Larson Pennsylvania

Transportation Institute (LTI). In a 2003 report, the data, findings, and conclusions from that study

were presented to PennDOT (Anderson et al., 2003). The WO 43 study was focused on the general

characteristics of materials used in Superpave design. That includes both binder and mixture

properties. Overall, the study included extensive laboratory testing of the materials obtained at the

time of construction to capture the engineering properties and to determine if the Superpave

mixtures exhibit adequate levels of resistance to rutting, thermal cracking, and fatigue damage.

Asphalt binder and asphalt concrete from more than 10 Superpave projects were obtained and tested

at NECEPT laboratories during WO 43. The WO 43 study did not include field performance

evaluation and in that respect the laboratory test results could not be correlated to the observed field

performance. As a result, PennDOT initiated a new work order (WO-9) titled “Field Focused

Superpave Validation” to complement findings of WO 43 through field performance measurements.

A number of WO 43 pavements were selected for evaluation. The projects were visited and detailed

data of observed distresses (rutting, cracking, and raveling) were collected. Some of the projects

were cored and the cores were tested at NECEPT laboratories. Major laboratory tests on cores

included specific gravity measurements, indirect tensile resilient modulus, indirect tensile creep and

strength, extraction and binder recovery, and finally, determination of the binder dynamic modulus

using the dynamic shear rheometer.

The pavement sections evaluated for this research were 9 to 10 years old at the time of the

pavement condition survey. They mostly exhibited satisfactory performance. The average rutting

was 5.4 mm and 6.4 mm for right wheel path and left wheel path, respectively, when all surveyed

projects are considered. The lowest measured rutting was about 2 mm (Centre I-80 right lane) and

the highest 11 mm (Lycoming SR 15, Southbound). The laboratory test results from the repeated

shear constant height tests on the wearing course at 52 ºC, conducted during the WO 43 project were

compared with the rut levels observed. No clear trend could be found. However, it could be

xiv

concluded that the laboratory shear strain values under 1 percent result in an acceptable rutting level

in the field.

The two pavement sections with the most dominant cracking were the ID-2 Marshall section

on the northbound lanes of Lycoming SR 15 and the PG 64-22 section of Clearfield SR 153.

Laboratory tests of indirect creep at low temperatures indicated lower compliance of these two

mixes compared to their companion sections at each site.

An investigation was also made into the level of aging observed in the field and how this

aging compares with laboratory-simulated aging. Such comparative analysis was conducted for

those projects from which cores were available. That includes Clearfield SR 153, Huntingdon SR

522, and Centre I-80. The results indicated that for both PG 64-28 and PG 64-22 sections at

Clearfield SR 153, the PAV laboratory simulation provided a significantly higher aging level (stiffer

binder) compared with actual aging observed in the field for a 10-year-old pavement. For the

Huntingdon SR 522 with an original PG 64-28 binder, the field-aged binder is closer to the PAV-

aged binder for this 9-year-old pavement. However, the wheel path core indicated lower stiffness

than the PAV laboratory simulation while the between-wheel-path core indicted higher aging.

Significantly higher air void level of between-wheel-path core could have contributed to the higher

level of aging observed for the binder of this core.

The overall conclusion from this study was that most of the projects included in the detailed

survey demonstrated satisfactory performance considering their age. Rutting levels were acceptable

and there were no considerable levels of cracking except the two cases mentioned above. Surveys of

these pavements indicated that longitudinal joint construction continues to be a serious concern, as

several projects were found with longitudinal joint cracks extending over a significant stretch of the

pavement.

Laboratory rutting tests (constant height repeated shear test at high temperature) on wearing

course did not deliver a good correlation with rutting levels observed, but the data provide a guide as

to the range of laboratory strain levels that could result in acceptable rutting levels. Unfortunately,

sufficient laboratory shear strain data were not available for the binder course of all pavements

surveyed, and it did not become possible to investigate the relationship between the rutting level and

the laboratory test results on the pavement binder layer.

1

CHAPTER ONE INTRODUCTION

The Superpave design system came into existence in the mid-1990s. Many pavements have

been constructed with Superpave designed hot mix asphalt (HMA). Today, this technology is well

established in many states. It has been over a decade since the Commonwealth of Pennsylvania

began using this system for designing HMA.

Since its inception, the system has gone through several specification revisions. The

compaction effort in the Superpave Gyratory Compactor was revised at the early stages, and a

simplified compaction requirement was introduced (Brown and Buchanan, 1999). The restriction on

aggregate grading, referred to as the restricted zone, was eliminated (Kandhal and Cooley, 2001).

There has been general satisfaction with the pavements constructed with this mix, and anecdotal

evidence suggests that Superpave pavements are performing well in Pennsylvania; however, within

the last several years there has been concern raised in regard to the durability of some Superpave

mixes. Some have reported these problems as a result of insufficient binder content in the mix. This

issue has been the driving force for several states to take measures to increase the binder content in

the mix. Some have been designing at a reduced number of gyrations while others have been

designing at an air void level about 1/2 percent lower than what is specified in Table 6 of AASHTO

specification M323-04. Both of these changes result in higher design binder content. There has also

been a move by some to increase the minimum required VMA to allow more space within the

aggregate structure for asphalt and therefore provide a higher binder content mix at a specified

design air void level. The Pennsylvania Department of Transportation (PennDOT) is now

specifying 1/2 percent higher VMA for all aggregate-size gradations than is specified in AASHTO

M323.

As the Superpave design criteria are evolving, it is worth looking back into the performance

of the pavements constructed with Superpave mixes. The research findings presented in this report

are the result of such effort, i.e., evaluating long-term performance of Superpave-designed mixes.

BACKGROUND

At the beginning of the implementation of Superpave in the Commonwealth, a series of

projects was selected for detailed study to validate and to determine the effectiveness of the

Superpave system in designing asphalt concrete mixtures of superior durability. Consequently, a

2

research project titled “Superpave Validation Studies” was sponsored by the Pennsylvania

Department of Transportation (PennDOT) in 1999. That study, under the University-Based

Cooperative Agreement (Contract No. 359704) Work Order 43, was conducted by the Northeast

Center of Excellence for Pavement Technology (NECEPT) at the Thomas D. Larson Pennsylvania

Transportation Institute (LTI). The data, findings, and conclusions from that study were presented to

PennDOT (Anderson et al., 2003). The WO-43 study focused on the general characteristics of

materials used in Superpave design, which includes both binder and mixture properties. Overall, the

study included extensive laboratory testing of these materials to capture the engineering properties

and to determine whether the Superpave mixtures exhibit adequate levels of resistance to rutting,

thermal cracking, and fatigue damage. Asphalt binder and asphalt concrete from more than 10

Superpave projects were obtained and tested at NECEPT laboratories during the WO-43. The goal

of the WO-43 study was also to determine whether the Superpave mixture performance-related tests

could be used to reliably predict mixture performance in the field. While laboratory testing was

comprehensive in the WO-43 project, it did not include field performance evaluation, and in that

respect, the laboratory test results could not be correlated to the observed field performance. No field

survey was conducted on these projects during the WO-43, and, therefore, no analysis was

conducted in regard to the relationship between the predicted performance from laboratory

characterization and the actual performance of these projects in the field. It was considered essential

for many of the WO-43 projects to be monitored and surveyed after several years in service and for

accurate measurements of rut depth, fatigue cracking, and thermal cracking to be made for these

projects. As a result, PennDOT initiated a new work order (WO-9) titled “Field Focused Superpave

Validation” to complement findings of WO-43 through field performance measurements. This work

was undertaken to evaluate the performance of these projects after they have been in service for

several years and determine their relationship with the material properties established in the

laboratories.

OBJECTIVES

The objectives of the WO-9 project could be summarized as follows:

• Follow up on the actual field performance of all the projects analyzed in the WO-43 project where materials were collected and materials characterization testing was performed.

• Conduct a pavement distress survey and performance measurements (rutting, cracking, etc.) of selected project pavement sections.

3

• Conduct laboratory material characterization testing on material from pavement cores drilled from some of the projects.

• Analyze and compare field-collected performance measurements and laboratory materials characterization results to the predicted performance from the original laboratory material characterization testing.

RESEARCH APPROACH AND SCOPE OF WORK

Through coordination with the PennDOT technical manager for this research project, a

number of WO-43 pavements were selected for evaluation. Selection was based on a number of

factors: availability of laboratory data and worthiness of the project in terms of comparative analysis

among different sections built for the pavement under the same project. In two cases, in spite of

insufficient laboratory data, the decision was made to conduct the pavement evaluation because of

the significance of the project in terms of comparing different designs or binders. The projects were

visited, and detailed data of observed distresses were collected. Some of the projects were cored,

and the cores were tested at NECEPT laboratories. Information from the pavement condition survey

and laboratory testing were analyzed. Findings are provided in this report.

4

CHAPTER TWO Scope of Field and Laboratory Investigation

Two major goals of this project were to evaluate and assess the condition of selected

pavements constructed during WO-43 research project, and to conduct an investigation into the

relationship between laboratory results and field observations. This chapter provides details of how

these two tasks were completed.

PAVEMENT CONDITION SURVEY

The first step toward establishing a framework for conducting field survey of projects

considered under WO-43 was to determine the extent of available laboratory data and sampled

materials. Task 1 of this research was directed toward this goal and was the basis for selection of

projects studied under WO-9.

Status of Available Data for Projects Considered Under WO-43

Nineteen projects were identified as the projects considered under WO-43. These projects

had been selected to evaluate the impact of a range of project variables on pavement performance.

Examples of such variables include differences in performance grade (PG) binders, differences in

performance of polymer modified binders, Superpave versus ID-2 Marshall mixes, layer thickness,

slow-moving vehicles, and pavement grade. Not all of these projects were selected for

comprehensive evaluation and material characterization under WO-43. The extent of material

procurement was vastly different for these projects. For some, a considerable amount of binder and

mixture had been collected. For others, no material was procured at the time of construction. The

extent of the laboratory work on the procured materials also varied within a wide range. Data from a

relatively comprehensive set of tests on both the binders and mixtures are available for some

projects. For others, testing has been very limited, and little laboratory data are available.

Table A.1 (Appendix A) presents the list of projects under WO-43. It is clear from this table

that the level of available data from laboratory material characterization varies within a wide range.

For four of the projects (Warren 0062, Schuylkill 0081, Bucks 0131, and Indiana 0022), no data are

available. The original plan called for the data from Schuylkill 0081 to come from a different

source; therefore, no material was received at NECEPT laboratories for this project. There was no

material received for Bucks 0131 and Indiana 0022 either. Of the four projects with no data, Warren

0062 is the only project for which materials of asphalt mixture for wearing and binder mixtures have

5

been received at NECEPT laboratories and are still available. Records also indicate that Warren

materials are available at PennDOT Materials and Test Division laboratories. For the Berks 0061

project, limited laboratory work has been conducted, and only volumetric and repeated shear test

data for the PG 64-22 mixture of this project are available.

For three of the projects (Crawford 0322, Centre 0080, and Huntingdon 522), only some

binder data are available. The Clearfield 0080 project is an important one considering the use of a

control binder along with five modified binders (with Novophalt, Polybilt, Kraton, Styrelf, and

Gilsonite). However, this project was milled and overlaid several years ago.

The Centre I-80 project is of interest because of using different aggregate size gradations for

wearing and binder courses and using different layer thicknesses. Unfortunately no mixture or

binder data is available for the Centre 0080 project, and there is currently no material of this mixture

available at NECEPT laboratories.

There is no mixture data currently available for the Huntingdon 522 project; however, binder

and base mixtures form this project are available at NECEPT laboratories in case of a future need to

conduct characterization tests on the mixtures. For the remaining projects, both the binder and

mixture data are available to various degrees. The most comprehensive laboratory data exists for

Lycoming 0015, York 0083, Franklin 0011, and Indiana 0422, and these were the projects originally

considered with the best chances of evaluation based on the laboratory data. Franklin 0011 is also of

interest because of using various polymer-modified binders.

Inventory of Materials

An investigation was conducted to determine the amount of binder and mixtures of WO-43

projects available at NECEPT laboratories. This was done to assess the possibility of conducting

further laboratory material characterization tests in case of a future need under an extension project.

Tables A.2 (Appendix A) presents the binder materials from WO-43 projects that are currently

available at NECEPT laboratories. The table indicates that the binder is available for several

projects; however, the available material is mostly for the projects for which binder characterization

data are already available. No material could be found for projects that have not been already

included for binder testing. Currently available binders could be used to complete the direct tension

test for those projects for which this property has not been already determined.

The available mixtures from different projects are presented in Table A.3 (Appendix A).

Available mixture from the Snyder 0011 project could possibly be used in limited testing, in case

6

needed under an extension project, to complete the current data set and to provide data from indirect

tensile test (IDT) for evaluation of low temperature cracking. In addition, the repeated shear test

data are not available for the binder course of this project, but the material is available to conduct a

limited number of such tests. For Fayette 0119, there is sufficient material to conduct one or more of

the mixture tests (strain controlled frequency sweep, the repeated shear test, and IDT) for the base as

well as the IDT for the binder course, for which there are no data available at this point. Similarly,

as shown in Table A.3, there is limited mixture available for York 0030. While there is currently

binder data available for this project, no mixture data could be found. Therefore, the available

mixture material for York 0030 could be tested to provide characterization of the mixture for this

project.

A list of cores currently available at NECEPT laboratories, as obtained as part of WO-43

project, is provided in Table A.4. The largest number of available cores belongs to binder layers of

Lycoming SR 15 and York SR 30. The existing inventory of materials (binders and mixtures) at

NECEPT could be integrated with the existing inventory at the laboratories of PennDOT Materials

and Tests Division.

Projects Selected for Performance Evaluation

Task 2 of WO-9 was dedicated to surveying the condition of pavements considered under

WO-43. The results of Task 1 analysis and consultation with the PennDOT technical manager were

used in deciding which of the WO-43 projects should be included in the pavement condition survey.

The projects presented in Table 1 were selected for evaluation under Task 2.

Table 1 Projects Selected for Condition Survey under Task 2.

District S.R.-Sec. - County 2-0 0153 - 225 - Clearfield 2-0 0080 - B22 - Centre 3-0 0015 - B43 - Lycoming 3-0 0015 - B42 - Lycoming 3-0 0011 - 38M - Snyder 8-0 0083 - 832 - York 8-0 0030 – B01 - York 8-0 0011-024 - Franklin 9-0 0070 - 009 - Fulton 9-0 522 - 001- Huntingdon 10-0 0422 - 404 - Indiana

7

Out of the projects presented in Table 1, six were selected for further evaluation and more

detailed analysis through procurement of cores (Table 2). This selection was considered to include

those projects with the largest available mixture and binder data or at least those for which a

comparative study of different sections would be valuable.

Table 2 Projects Selected for Coring.

District S.R.-Sec. - County

2-0 0080 - B22 - Centre

2-0 0153 - 225 - Clearfield

3-0 0011 - 38M - Snyder

3-0 0015 - B43 - Lycoming

3-0 0015 - B42 - Lycoming

9-0 522 - 001- Huntingdon

Scope of Performance Evaluation

Evaluation of pavements was conducted at two stages. The first stage, considered

preliminary evaluation, was carried out to

• identify location of the sections for detailed evaluation. • provide initial assessment of pavement condition. • determine whether the pavement is a good candidate for detailed evaluation.

The PennDOT and PTI personnel were both present at the site for the preliminary evaluation.

Based on this evaluation, I-70 in District 9 and SR 422 in District 10 were dropped from the list for

detailed evaluation. The former was found to be too extensive in terms of number of sections to be

included in this research and appeared to be a good candidate for thorough investigation under a

different research project. The latter was dropped since the pavement was found to have been

overlaid. The decision was made to continue with a detailed condition survey of the remaining nine

projects presented in Table 1. As the detailed investigation of projects began, difficulties arose with

scheduling site visits for some of the sites within the time frame of the project, and finally, the

detailed evaluation could only be conducted for six of the nine selected projects. Similarly, coring

was only conducted for three of the six projects selected even though all six were marked for coring

at the time of the detailed evaluation. Table 3 summarizes what was finally accomplished regarding

8

the pavement condition evaluation and coring for selected projects. The date of completing the

activity is also provided in the table.

Table 3 Pavement Sections Surveyed or Cored Under WO-9.

District S.R.-Sec. - County

Preliminary

Evaluation

Detailed

Evaluation

Coring

2-0 0153 - 225 - Clearfield

11/14/06

07/11/07

07/18/07

07/11/07

07/18/07

2-0 0080 - B22 - Centre 11/14/06 07/19/07

07/31/07

07/31/07

3-0 0015 - B43 - Lycoming 11/13/06 06/05/07 __

3-0 0015 - B42 - Lycoming 11/13/06 06/06/07 __

3-0 0011 - 38M - Snyder 11/13/06 06/14/07 __

8-0 0083 - 832 - York 04/09/07 __ __

8-0 0030 – B01 - York 04/09/07 __ __

8-0 0011-024 - Franklin 12/05/06 __ __

9-0 0070 - 009 - Fulton 12/05/06 __ __

9-0 522 - 001- Huntingdon 12/05/06 11/08/2007 11/08/2007

01/08/08

10-0 0422 - 404 - Indiana 11/14/06 __ __

Detailed Pavement Evaluation Procedure

Conducting a detailed pavement performance evaluation was a major part of this project.

The main idea was to determine the quality of these Superpave pavements after being in service for

9 to 10 years. The surveyed pavements were built between 1997 and 1998. The total length of the

pavement section surveyed varied for each project depending on the project size, number of sections,

geometric limitations, and time limitations. Overall, the total length of each surveyed section was

between 750 and 1500 feet. The total length surveyed for each project was dependent on the number

of sections surveyed and for the longest one was 5,000 feet. The travel lane (right-hand lane in

direction of traffic) was selected as the survey lane. Clearfield SR 153 and Huntingdon SR 522,

9

were both two lane roads, and therefore, for the former, the northbound lane was surveyed, and for

the latter, the southbound was considered. Another exception was the Snyder SR 11 project, for

which both the passing and travel lanes on the southbound side were surveyed.

At each site location, once traffic control was established, the start and end points of the

survey area were established. The pavement shoulder was then marked at 100-ft intervals to provide

the opportunity for detailed mapping of distresses at small intervals. This was followed by taking

numerous photos of the pavement mat throughout the whole stretch of the road selected for survey.

A transverse profiler was used to determine the rut depth. Transverse profiling of the pavement and

determination of crack length and type were conducted in parallel. A wheel manufactured by

Calculated Industries (DigiRoller Plus 2) was used to measure the crack length. FHWA publication

“Distress Identification Manual for the Long-Term Pavement Performance Program” was used as a

guide for determination of crack type and severity.

Transverse Profiles (Rutting)

Transverse profiles at each site were captured at 200- to 400-ft intervals. At least five

profiles were captured for each project, and three profiles were obtained for each section if the

project contained more than one section.

The rut depth measurement equipment was a simple system consisting of a 14-ft long

aluminum I-beam, a depth gauge, and a laptop computer to capture data (Figure 1). The beam

spanned the pavement section transversely, resting on tripods at both ends. A Mitutyo Digimatic

Absolute Depth Gauge was aligned vertically adjacent to the beam and connected to a laptop

computer. Every time the triggering button on the meter was activated, the measured depth was

transferred to the spreadsheet file developed on the laptop computer. Measurements with this

system were conducted at 50 mm intervals along the beam.

10

Figure 1 Transverse profiling using the digital depth meter.

Criterion to Determine Rut Depth

Rutting manifested at the pavement surface is the result of densification of HMA layers and

shoving of the material to the sides due to shear load imposed by load on the wheel path. It is also

partly the result of densification and shear movement of the underlying unbound layers.

The approach presented in Figure 2 was uniformly followed for all projects to determine rut

depth. A straight line was applied tangent to the two peaks observed at the shoulder and at the line

between two lanes. The distance between the mid-point of this tangent and the deepest point in the

wheel path was measured and considered as the rut depth.

11

Typical Transverse Profile

98

100

102

104

106

108

110

04080120160200240280320360400440Distance, cm

Rea

ding

, mm

Rut

h D

epth

Figure 2 Approach used in this project to determine rut depth.

Field Seismic Modulus Testing

Parallel to obtaining cores, attempts were made to determine in-situ elastic modulus of

asphalt concrete using Portable Seismic Pavement Analyzer (PSPA).

Theoretical Background

If an elastic half-space is disturbed by a vertical impact on the surface, two types of waves

will propagate in the medium: body and surface waves. Body waves propagate radially outward in

the medium and are composed of two different types: compression and shear waves. These waves

are differentiated by the direction of particle motion relative to the direction of wave propagation.

Particle motions associated with shear waves are perpendicular to the direction of wave propagation,

whereas particle motions associated with compression waves are parallel to the direction of wave

propagation. Surface waves resulting from a vertical impact are primarily Rayleigh waves, which

propagate away from impact along a cylindrical wavefront near the surface of the medium.

The Spectral Analysis of Surface Wave (SASW) method can be used for in situ evaluation of

elastic moduli and layer thicknesses of layered systems like soils and pavements (Nazarian and

Stokoe 1984). The method is based on the phenomenon of Rayleigh wave dispersion in layered

12

systems, i.e. the phenomenon that the velocity of propagation is frequency dependent. Because shear

wave velocity and shear modulus are mainly dependent on the effective stress and density, the

SASW method is useful in estimating the changes in material strength and density. In layered media,

the velocity propagation of surface waves depends on the frequency (or wavelength) of the wave

because waves of different wavelengths sample different parts of the layered medium. The algorithm

of the SASW method is to determine the velocity-frequency relationship described by the dispersion

curve, and then, through the process of inversion or backcalculation, to obtain the shear wave

velocity profile. Elastic moduli profiles can then be easily obtained using simple relationships with

the velocity of propagation and measured or approximated values for mass density and Poisson’s

ratio in two steps:

1. The relationship amongst velocity, V, travel time, Δt, and receiver spacing, ΔX, can be written in the following form:

tXV

ΔΔ

= (1)

In this equation, V can be the propagation velocity of any of the three waves (i.e.

compression wave, VP; shear wave, VS; or surface (Rayleigh) wave, VR). Knowing wave

velocity, the modulus can be determined in several ways.

2. Elastic modulus, E, can be determined from shear modulus, G, through the Poisson's ratio, υ, using:

GE )1(2 υ+= (2)

Shear modulus can be determined from shear wave velocity, VS, and mass density, ρ,

using:

2

SVG ρ= (3)

Portable Seismic Pavement Analyzer

The Portable Seismic Pavement Analyzer (PSPA), as shown in Figure 3, is a device designed

to determine the modulus of the top pavement layer in real-time. The PSPA consists of two receivers

13

(accelerometers) and source packaged into a hand-portable system which can perform high

frequency seismic tests.

source

electronics box

receivers

source

electronics box

receivers

Figure 3 Portable Seismic Pavement Analyzer (PSPA)

The analysis method implemented in the PSPA is called the ultrasonic surface waves (USW)

method which is a simplified version of the SASW method. The major distinction between these two

methods is that, in the USW method, the modulus of the top pavement layer can be directly

determined without an inversion algorithm (Nazarian et al. 1993). As surface waves (Rayleigh, R

waves) contain most of the seismic energy, the USW method utilizes the surface wave energy to

determine the variation in modulus with wavelength. Detailed review of NDT applications using

surface wave methods can be found elsewhere (Nazarian et al. 1993, Goel and Das 2006). At

wavelengths less than or equal to the thickness of the uppermost layer, the velocity of propagation is

independent of wavelength. Therefore, if one simply generates high-frequency (short-wavelength)

waves, and if one assumes that the properties of the uppermost layer are uniform, the shear wave

velocity of the upper layer, VS, can be calculated from surface wave velocity, VR:

)16.013.1( υ−= RS VV (4)

Then, the elastic modulus of the top layer, E, can be determined:

14

[ ]2)16.013.1()1(2 sVE υυρ −+= (5)

Field PSPA Testing

To collect data with a PSPA, the technician initiates the testing sequence through the

computer. The high-frequency source is activated four to six times. The outputs of the two receivers

from the last three impacts are saved and averaged (stacked). The other (pre-recording) impacts are

used to adjust the gains of the amplifiers. The gains are set in a manner that optimizes the dynamic

range. Typical voltage outputs of the three accelerometers are shown in Figures 4a. In this plot, the

red line presents the signal from the electronic source, while black and green lines indicate signals

from accelerometers 1 and 2. An actual variation in modulus with wavelength from the time records

(data reduction process) is shown in Figures 4b. For practical reasons, the wavelength is simply

relabelled as depth. In that manner, the operator of the PSPA can get a qualitative feel for the

variation in modulus with depth. The red solid line represents the average seismic modulus of the

pavement layers. It should be noted that the modulus at a depth smaller than 50 mm could not be

determined due to the fixed spacing between the two accelerometers of the PSPA. The dispersion

curve shown in Figures 4b is developed from the phase spectra shown at the bottom of the same

figure. The phase spectrum, which can be considered as an intermediate step between the time

records and the dispersion curve (Nazarian et al. 1993), is determined by conducting Fourier

transform and spectral analysis on the time records from the two accelerometers. This step makes the

determination of the modulus with wavelength much easier.

(a) signal (b) data reduction

Figure 4 Sample PSPA data

15

LABORATORY INVESTIGATION

The laboratory investigation included preparation of the cores and conducting a series of

tests on the prepared cores. Preparation included taking pictures of the cores, assessment of the core

condition, measuring thickness of the different layers on each core, and cutting cores to separate

different layers. Testing included indirect tensile resilient modulus, indirect tensile creep and

strength, specific gravities, extraction, determination of gradation and asphalt content, binder

recovery, and determination of binder stiffness using a dynamic shear rheometer. Tables 4 and 5

present the tests conducted on the cores and the asphalt binder, respectively:

Table 4 Tests Conducted on the Cores for WO-9 Project.

Designation Standard Method of Test for AASHTO

T 322-03

Determining the Creep Compliance and Strength of Hot-Mix Asphalt

(HMA) Using the Indirect Tensile Test Device

ASTM D4123 Standard Test Method for Indirect Tension Test for Resilient Modulus of

Bituminous Mixtures

AASHTO

T 166-05

Bulk Specific Gravity of Compacted Hot-Mix Asphalt Using Saturated

Surface-Dry Specimens

AASHTO

T 209-05

Theoretical Maximum Specific Gravity and Density of Hot-Mix Asphalt

Paving Mixtures

AASHTO

T 164-05

Quantitative Extraction of Asphalt Binder from Hot-Mix Asphalt (HMA

AASHTO

T 30-05

Mechanical Analysis of Extracted Aggregates

Table 5 Tests Conducted on the Asphalt Binder for WO-9 Project.

Designation Standard Method of Test for ASTM

D5404-03

Recovery of Asphalt from Solution Using the Rotary Evaporator

AASHTO

T 315-05

Determining the Rheological Properties of Asphalt Binder Using A

Dynamic Shear Rheometer (DSR)

The bulk specific gravity of the cores was determined using AASHTO T166. This was

followed by the indirect tensile testing. Afterward, the cores were broken loose in an oven set at a

temperature of 135°C for a period of 30 to 60 minutes depending on the size of the specimen. This

16

was followed by determination of the maximum theoretical specific gravity (Gmm) of the cores

according to AASHTO T209. Upon completion of the Gmm tests, the cores were processed through

extraction (AASHTO T164) so that the binder could be recovered (ASTM 5404). The recovered

binder from these cores was subject to determination of the complex modulus using the dynamic

shear rheometer (AASHTO T315).

Preparation of Cores

Cores were first photographed, and the thickness of different layers for each core was

measured. The pictures of the cores are provided in Appendix B. The cores were then cut at the

layer interface using a single saw blade to provide separate specimens from each core representing

different pavement layers.

Indirect Tensile Creep and Strength Testing

Testing apparatus:

All IDT tests were carried out using hydraulic loading systems manufactured by MTS®. The

MTS system consists of a 100 kN (22 kip) load frame and actuator interfaced with an MTS® 458.20

Micro Console fitted with an MTS® 458.91 MicroProfiler to program loading modes. An MTS®

409.80 temperature controller is interfaced with an environmental chamber that contains an electric

heater and a mechanism for handling liquid nitrogen for cooling. This temperature controller is

supplemented by a separate mechanism to monitor specimen temperature before testing. This is

accomplished by monitoring the temperature readout measured from a thermocouple embedded in a

dummy specimen that is prepared with the same mixture and satisfies all specifications for the actual

test specimen. Data acquisition is performed using a separate computer fitted with a National

Instruments® 6329 DAQ card. For tests in IDT mode, four XS-B LVDTs with a range of ±0.25 mm

are used to measure the vertical and horizontal deformation. These LVDTs are fitted onto aluminum

mounts sitting on steel targets. The targets are glued on the specimen using a five-minute epoxy.

Testing Protocol:

The testing protocol is in accordance with AASHTO T322. In this test, tensile creep and

tensile strength are determined on the same specimen for thermal cracking analysis. The tensile

creep is determined by applying a static load of fixed magnitude along the diametric axis of a

specimen for 100 seconds at temperatures of 0°C, -10°C, and -20°C (Figure 5). The horizontal and

17

vertical deformations measured across a gauge length of 1.5 inches near the center of the specimen

are used to calculate creep compliance as a function of time. Loads are selected to keep horizontal

strains in the linear viscoelastic range (typically below a horizontal strain of 500 µstrains) during the

creep test. After the fixed load is applied, the tensile strength will be determined by applying a load

to the specimen at the rate of 12.5 mm per minute (vertical ram movement) to failure at -10°C.

Typically, the maximum strength of the specimen occurs at a point prior to failure, and, hence, the

vertical and horizontal LVDTs measurements are used to accurately determine the value of tensile

strength (AASHTO T322). It was found earlier (NCHRP 530), as well as during the course of this

testing, that there could be possible damage to the LVDTs when the specimen fails during the

strength test. Hence, the LVDTs were removed prior to the strength test, and the correct strength was

determined using a correction equation developed by Christensen and Bonaquist (2004).

σIDT/Corr = 0.27 + 0.78*σIDT

Figure 5 Compression testing of the cores in diametral direction to determine indirect tensile

creep and strength.

Resilient Modulus Testing

Prior to conducting the indirect tensile creep tests on cores, indirect tensile resilient modulus

tests were conducted on cores from Huntingdon SR 522 and Centre I-80. The purpose of this

testing was to provide further information on the engineering properties of these two projects since

no original IDT data were available.

The resilient modulus tests were conducted in accordance with ASTM D4123. The values of

resilient modulus can be used to evaluate the relative quality of materials and also as an input for

18

pavement design or pavement evaluation and analysis. Being non-destructive in nature, multiple

tests can be repeated on the same specimen. Furthermore, this test can be used to study the effects of

temperature, loading rates, rest periods, etc. (ASTM D4123). Though different temperatures and

loading rates can be used for the test, in this study, all the tests were conducted at 25˚C with a

loading time of 0.1 seconds and rest period of 0.9 seconds because of time constraints. The number

of load cycles was restricted to maintain the cumulative vertical deformation within 0.0381 mm (100

μstrains). Though this limit was exceeded in some of the tests, they were well within the limits

defined by ASTM standards. The total resilient modulus was calculated in accordance with the

ASTM standards using the last five deformation cycles. A poison’s ratio value of 0.35 was assumed

for the calculation (Barksdale et al., 1997). A sample of the loading cycle, horizontal deformation,

and vertical deformation, as a function of time, are shown in Figures 6 through 8, respectively.

19

Load cycles (kN) vs Time(s)

-0.4

-0.35

-0.3

-0.25

-0.2

-0.15

-0.1

-0.05

71.5 72 72.5 73 73.5 74 74.5 75 75.5

Time(s)

Load

(kN

)

Figure 6 Load cycle (kN) vs. time(s).

Horizontal Deformation (mm) vs Time(s)

-0.0065

-0.0064

-0.0063

-0.0062

-0.0061

-0.006

-0.0059

-0.0058

-0.0057

-0.005670 70.5 71 71.5 72 72.5 73 73.5 74 74.5 75

Time(s)

Hor

izon

tal d

efor

mat

ion

Figure 7 Horizontal deformation (mm) vs. time(s).

20

Vertical Deformation(mm) vs Time(s)

0.008

0.0082

0.0084

0.0086

0.0088

0.009

0.0092

0.0094

0.0096

0.0098

0.01

55 55.5 56 56.5 57 57.5 58 58.5 59 59.5 60

Time(s)

Vert

ical

Def

orm

atio

n(m

m)

Figure 8 Vertical deformation (mm) vs. time(s).

The total resilient modulus is calculated using the formula:

ERI = P (VRT +0.27)/ (tΔHT)

where

ERI = Total resilient modulus of elasticity in MPa

P = Repeated load (kN)

VRT = Total resilient poisons ratio ( assumed as 0.35)

t = Thickness of specimen (mm)

ΔHT = Total recoverable horizontal deformation

Asphalt-Aggregate Extraction

After completion of mechanical testing, the binder from the cores was first extracted using

centrifuge extraction according to AASHTO T 164. Briefly, the extraction uses a centrifuge and

solvent to dissolve and extract the asphalt from a sample. The procedure requires a centrifuge,

solvent, container for catching the solvent, filter ring, and other standard laboratory equipment to

21

perform the test method. To begin, the test sample, filter, and empty ignition dish are weighed, and

the values are recorded. Next, the test sample is placed into the centrifuge bowl and covered with

the solvent. Enough time is allowed for the sample to get dissolved. After the sample has been

dissolved, the filter is placed on the bowl and covered with the lid tightly. A container is placed to

catch the solvent beneath the drain of the centrifuge. The centrifuge is started slowly, and the speed

is gradually increased to the maximum of 3600 rpm until the solvent ceases to flow from the drain.

After the centrifuge has stopped rotating, an additional 200 mL of solvent is added, and the

extraction continues. Additional solvent must be added in 200 mL quantities until the extract is

clear and no darker than a light straw color.

When the extract color flows clear from the drain, the filter ring is removed from the bowl

and is let to air dry. After air drying, the mineral matter is removed from the filter ring as much as

possible and is placed into the centrifuge bowl with the aggregate. Then, the filter ring is placed into

an oven at 163oC and dried to a constant mass, after which its weight is recorded. Next, the collected

extract solvent is agitated, and a 100-mL aliquot is measured and placed into the ignition dish. First,

the ignition dish is dried on a hot plate; then, it is burned at a dull, red heat at 600oC, cooled, and

weighed, and then 5 mL of saturated ammonium carbonate solution is added per gram of the ash.

The mixture is then digested at room temperature for one hour and then placed into an oven at 110oC

to dry and then cooled in a desiccator and weighed to 0.001 grams. Last, the volume of the extracted

solvent solution and also the mass of the extracted mineral matter are recorded.

Binder Recovery

Once extraction was completed, the binder was recovered using a rotary evaporator

according to ASTM D 5404. In brief, the binder is recovered from the solvent solution by using a

rotary evaporator to evaporate, condense, and then recover the solvent in a separate flask. The

binder remains in the distillation flask. First, an oil bath is heated to 140oC, and water is circulated

through the condenser. A 500-mL sample of the solvent solution is added to the distillation flask

and then is attached to the evaporator. Next, a vacuum is applied at 5.3 kPa, and a nitrogen flow of

500 mL/min is added to the system. The distillation flask is then lowered into the hot oil bath and

begins to rotate until most of the solvent solution is evaporated, and then an additional 500-mL

sample of the solvent solution is added, and this procedure is repeated until all of the solvent

solution has evaporated. After the bulk of the solvent has been distilled from the asphalt and no

noticeable condensation is occurring in the condenser, the flask is then immersed to a depth of 1.5

22

in, a vacuum is applied at an increased pressure of 80.0 kPa, and the nitrogen flow is increased to

600 mL/min. This is applied for a total of 15 minutes, after which the asphalt is then poured into

containers for storage.

23

CHAPTER THREE ANALYSIS, INTERPRETATION, AND FINDINGS

This chapter covers the results of field and laboratory investigation as part of this research

project. The chapter is divided into two major sections. The first section provides a discussion of

pavement evaluation, and the second section covers laboratory tests results and comparison of field

and laboratory data.

SECTION 1: RESULTS OF PAVEMENT CONDITION EVALUATION

The projects selected and visited under this research project and the approach taken in

evaluating pavement condition was presented in a preceding chapter. Details of each pavement

section and the range of distress evaluation are covered in Appendix C. In this section, for each

project, explanation is provided on the distresses observed and the overall condition of the

pavement.

Evaluation Results for SR 15 Northbound, Lycoming County

Cracking

ID-2 Section-Northbound: Cracking appeared dominant in this section. The width of the

cracks were mostly in the range of 1 to 5 mm, with a few as wide as 15 mm. Longitudinal cracks

were not significant, and the total length of this type of crack did not exceed 50 ft for the whole

stretch of road surveyed, and this was mostly both in the left and right wheel path. Transverse cracks

were more dominant as the total measured length was approximately 100 ft. No pattern could be

found for this cracking and was mostly sporadic. Remaining cracks on the pavement were mostly

fatigue cracking of low to medium severity and in a few spots were of high severity. The total area

of fatigued pavement was approximately 200 ft2. Longitudinal construction joint cracks between the

two lanes were severe and continuous for a long stretch of the surveyed section. There was also

significant longitudinal crack length observed to the right of the white stripe between the travel lane

and shoulder heading north.

Superpave Section-Northbound: The section overall looked good. Compared to the ID-2

section, very few cracked areas were observed at this section. Total length of all cracks was

approximately 95 ft. These cracks were mostly superficial and sporadic with no specific pattern.

24

There was a continuous stretch of 400 ft of cracking observed in longitudinal direction between the

wheel path for the first 400 ft of the section surveyed. In this cracked area, there were small areas of

minor raveling and segregation. No transverse cracks could be found on this section. After this 400-

ft stretch, the mat appeared in a significantly better condition, with no signs of raveled or segregated

areas. Contrary to the ID-2 section, the longitudinal construction joint cracking was also absent

from this section.

Superpave Section-Southbound: This is a Superpave section over jointed concrete

pavement. Fatigue and transverse cracks were absent from this section. Longitudinal cracking

appeared to be the only type of cracking observed in this section. The total length of this type of

crack was 470 ft in the 750-ft stretch of road that was surveyed. This length includes the

longitudinal crack observed between the travel and passing lanes. The length between wheel path

cracking (close to the center of the lane) was about 70 ft. The longitudinal cracking under the left

wheel path was approximately 230 ft, while the right wheel path cracking was about 54 ft. No

construction joint was observed for this section, implying possible construction of both lanes

together.

Rutting

Rutting for different sections is presented in Figures 9 through 12, and Tables 6 and 7. The

ID-2 section exhibits lower rutting, on the average, compared with the full-depth construction of the

northbound full-depth Superpave section and the southbound overlay Superpave section. This is

consistent with laboratory shear strain results for the wearing course as the ID-2 section had the

lowest permanent shear strain for the wearing layer as well as for the average of the strain for both

the wearing and binder layers, compared with the Superpave sections.

25

Figure 9 Transverse profile at Lycoming SR 15- northbound, ID2 section.

26

Figure 10 Transverse profile at Lycoming SR 15- northbound, Superpave section.

Figure 11 Transverse profile at Lycoming SR 15- southbound, Superpave overlay section.

27

Figure 12 Transverse profile at Lycoming SR 15- southbound, Superpave full section.

Table 6 Measured Rut Depth for Lycoming SR 15 – Northbound.

Rut Depth (mm) Rut Depth (mm)

Distance, ft Left Right Distance, ft Left Right

100 4.5 6.0 500 10.5 3.5

700 5.0 5.0 800 7.5 5.0

1300 4.0 1100 8.0 7.0

1400 6.0 4.5

Average 4.5 5.5 Average 8.0 5.0

Std. Dev. 0.5 0.71 Std. Dev. 1.62 1.27

ID2

Full

Depth

Const.

C.O.V. 11.1 12.9

Superpave

Full

Depth

Const.

C.O.V. 20.3 25.5

28

Table 7 Measured Rut Depth for Lycoming SR 15 – Southbound.



100 8.5 4.5 800 5.0 7.0

200 6.0 3.0 900 7.5 9.0

300 7.0 3.5 1000 6.0 13.5

500 7.0 2.0 1100 6.0 15.0

600 5.5 5.0


Std. Dev. 1.15 1.19 Std. Dev. 1.03 3.75

Superpave

over

Concrete

C.O.V. 16.9 33.2

Superpave-

Full

Depth

Const.

C.O.V. 16.8 33.7

Pictures showing general appearance of the pavement sections are presented in Figures

13 through 15.

29

Figure 13 Pictures of Lycoming SR 15 pavement – ID2, northbound.

30

Figure 14 Pictures from Lycoming SR 15, Superpave full depth, northbound.

31

Figure 15 Pictures of Lycoming SR 15 pavement, Superpave over concrete, southbound.

32

Evaluation Results for Highway SR 11, Snyder County

Overall, this pavement appeared to be in good shape. A few spots of minor raveling and loss

of fines were observed on the surface.

Cracking

The level of cracking on the mat was found to be limited. No transverse cracks were

observed on this pavement. The total length of sporadic cracks was approximately 110 ft within the

1500-ft length surveyed. Most of this cracking was observed within the right wheel path of the

travel lane.

Major cracking was the continuous longitudinal crack at the construction joint between the passing

and travel lanes, as well as between the travel lane and shoulder. This longitudinal joint crack was

observed throughout most of the 1500-ft length surveyed.

The pavement was also surveyed for a length of 300 ft on the southbound lane, north of Mill

Rd. No distresses were observed except the longitudinal cracking at the joints. Most of the passing

lane within the 300 ft surveyed appeared to be in excellent shape.

Rutting

Figures 16 through 18 and Tables 8 and 9 present rutting results for Snyder SR 11. Rutting

in excess of 12 mm was observed at the vicinity of the 11th Street intersection due to slow-moving

traffic. As we moved farther from the intersection, the rutting decreased. Average rutting observed

at distances away from the intersection was approximately 6 to 7 mm. On average, the left and right

wheel paths indicated similar levels of rutting.

33

Figure 16 Transverse profile at Snyder SR 11- southbound passing lane.

Figure 17 Transverse profile at Snyder SR 11- southbound travel lane.

34

Figure 18 Transverse profile at Snyder SR 11- southbound travel lane.

Table 8 Measured Rut Depth for Snyder SR 11 – Southbound.



50 14.0 13.5 500 5.5 7.5

100 15.0 12.0 400 6.5 7.5

274 8.5 10.0 300 7.0 6.0

308 7.5 8.0 Average 6.3 7.0

500 7.0 7.0 Std. Dev. 0.76 0.87

700 6.5 9.0

Travel

Lane

North Of

Mill

Road

C.O.V. 12.1 12.4

Average 9.8 9.9

Std. Dev. 3.75 2.46

Travel

Lane

North of

11th Street

C.O.V. 38.5 24.8

35

Table 9 Measured Rut Depth for Snyder SR 11- Southbound.

Rut Depth (mm)

Distance, ft Left Right

500 7.0 5.0

400 6.5 4.5

300 6.0 4.5

Average 6.5 4.7

Std. Dev. 0.41 0.29

Passing

Lane

C.O.V. 6.3 6.2

Pictures showing general appearance of the pavement sections for Snyder SR 11 are

presented in Figure 19.

36

Figure 19 Pictures of Snyder SR 11 pavement, southbound.

37

EVALUATION RESULTS FOR SR 153-SECTION 225, CLEARFIELD COUNTY

Cracking

PG 64-22 Section: Cracking appeared dominant in this section. The first 600 ft of the

surveyed section exhibited significant cracking. The amount of cracking at the remaining 500 ft was

considerably lower than the first 600 ft. The width of the cracks was mostly in the range of 3 to 5

mm, but some were as wide as 10 to 17 mm. Longitudinal cracks both in the right and left wheel

paths were obvious, with medium severity (crack width > 6mm). Total length of wheel path

cracking was 227 ft in the right wheel path and 236 ft in the left wheel path. Non-wheel path

longitudinal cracking was measured to be approximately 51 ft, with low severity (crack width <

6mm). Transverse cracks were observed with low severity (crack width < 6mm), but no pattern

could be found, and they were sporadic. Total length of transverse cracks was about 157 ft.

Longitudinal joint cracks between the two lanes was severe, and in some cases very severe, and

continuous for a long stretch of the surveyed section. Of the 1100 ft surveyed, the total length of

longitudinal joint cracking was about 980 ft. Total length of cracking measured (excluding

longitudinal joint cracking) was approximately 735 ft. Cracking was also observed at the

shoulder/lane interface area. These cracks were mostly concentrated on the shoulder at a distance of

about 5 ft from the white stripe, but some were right at the edge close to the stripe. These cracks

were mostly of medium severity, with a total length of about 647 ft. Some of the edge cracks,

however, were very severe.

PG 64-28 Section: For the 1000-ft stretch of the road surveyed for the PG 64-28 section, the

pavement appeared in significantly better condition compared with the PG 64-22 section. There

were no cracks observed on the mat. The pavement for the most part looked very uniform. Only

minor raveling close to the left wheel path (between the center of wheel path and longitudinal

construction joint) was observed in some areas. The only cracking observed on the mat was the

longitudinal cracks in the left wheel path. This was limited as the total length of this low severity

cracking was about 46 ft.

Rutting

While multiple transverse profiles could be obtained for PG 64-22 section, only one

38

relatively meaningful graph for rutting could be obtained for the PG 64-28 section (Figures 20 and

21, and Table 10). Overall, it was observed that the left wheel path rutting was larger for the PG 64-

28 section compared to the PG 64-22 section. Average rutting for both sections was approximately

6 to 7 mm.

39

Figure 20 Transverse profile at Clearfield SR 153- northbound, PG 64-22 section.

Figure 21 Transverse profile at Clearfield SR 153- northbound, PG 64-28 section.

40

Table 10 Measured Rut Depth for Clearfield SR 153-Northbound.



0 6.0 6.5 800 9.5 4.0

200 7.0 4.0 Average 9.5 4.0

400 7.5 9.5 Std. Dev. 0 0

600 5.5 7.0

PG 64-28

C.O.V. 0 0

800 6.0 7.0

Average 6.4 6.8

Std. Dev. 0.82 1.96

PG 64-22

C.O.V. 12.8 28.8

Pictures showing general appearance of the pavement sections at Clearfield SR 153 are

presented in Figures 22 and 23.

41

42

Figure 22 Pictures of Clearfield SR 153 pavement, PG 64-22 section.

43

Figure 23 Pictures of Clearfield SR 153 pavement, PG 64-28 section.

44

EVALUATION RESULTS FOR I-80, EASTBOUND, CENTRE COUNTY

Cracking

MP 167-167.5: The pavement mat was free of cracks in the section surveyed. No cracks of

any type were found except longitudinal cracks at the white stripe between the travel lane and the

shoulder. This crack was continuous throughout the 1000-ft section surveyed. The cracks were

mostly located 4 to 7 inches to the right of the white stripe.

There was slight raveling and loss of fines observed on the surface in some areas throughout

the pavement; however, the pavement looked uniform and in a relatively good shape.

MP 167.5-168: Overall, this section was similar to the previous section. No cracks of any

kind were found except the edge crack between the travel lane and shoulder throughout the whole

section. Minor loss of fines from the surface was observed; otherwise, the mat looked very uniform.

MP 168-168.5: Similar to the two previous sections, no cracks were observed except the

edge crack discussed previously. Even though loss of fines and raveling was minor, it was more

prominent compared to previous sections. This is probably because the wearing course in this

section was a 19 mm mix, and in the previous two sections, a 12.5 mm mix was used at the surface.

MP 168.5-169: This section was very similar to the first two sections, with minor raveling

present. The crack between the travel lane and shoulder was observed as before except with less

severity in some areas.

MP 169-169.5: This section appeared the best section, with no cracks. Even the cracking

between the travel lane and shoulder were absent in this section. The mat looked uniform.

Rutting

The range of rutting for all sections varied between 2 and 6 mm (Figures 24 through 28, and

Tables 11 through 13) . For all cases, the level of rutting in the left wheel path was larger than that

in the right wheel path. The difference between different sections was in the aggregate size (12.5

mm versus 19 mm for the wearing course and 19 mm versus 25 mm for the binder course) and the

45

layer thickness (40 mm versus 50 mm for the wearing layer and 50 mm versus 75 mm for the binder

layer). From measurements, it can be concluded that none of the sections is manifesting excessive

rutting.

46

Figure 24 Transverse profile at Centre I-80, eastbound, MP 167.0 to MP 167.5.

Figure 25 Transverse profile at Centre I-80, eastbound, MP 167.5 to MP 168.

47


Figure 27 Transverse profile at Centre I-80, eastbound, MP 168.5 to MP 169.

48


Table 11 Measured Rut Depth for Centre I-80, Eastbound.



200 4.5 200 5.0 2.0

400 4.0 3.5 400 5.0 2.0

600 4.5 3.0 600 5.5 2.0

800 5.0 3.5 Average 5.2 2.0

Average 4.5 3.3 Std. Dev. 0.29 0.00

Std. Dev. 0.41 0.29

MP

167.5 to

168.0

C.O.V. 5.6 0.0

MP

167.0 to

167.5

C.O.V. 9.1 8.7

49




200 6.5 2.0 200 4.5 4.0

400 5.5 2.5 400 5.0 5.0

600 6.5 2.5 600 4.0 3.5


Std. Dev. 0.58 0.29 Std. Dev. 0.50 0.76

MP

168.0 to

168.5

C.O.V. 9.4 12.4

MP

168.5 to

169.0

C.O.V. 11.1 18.3


Rut Depth (mm)


200 4.5 4.0

600 5.0 3.5

800 6.0 4.5

Average 5.2 4.0

Std. Dev. 0.76 0.50

MP

169.0 To

169.5

C.O.V. 14.8 12.5

Pictures showing general appearance of different pavement sections at Centre I-80 are

presented in Figures 29 and 30.

50

Figure 29 Pictures of Centre I-80 pavement.

51

Figure 30 Pictures of Centre I-80 pavement.

52

EVALUATION RESULTS FOR SR 522, SOUTHBOUND – HUNTINGDON COUNTY

Cracking

Overall, the pavement appeared to be in good condition. Cracking on the pavement mat was

very limited. The only cracks on the mat were left wheel path longitudinal cracks with a total length

of about 31 ft at three different locations. The crack width did not exceed 3 mm. No transverse or

fatigue crack was observed at any point on the mat. The most dominant cracking was observed at

the white stripe between the shoulder and the travel lane, with a total length of about 56 ft. In a long

section of the road, about 430 ft, the cracking was also observed at a distance of about 20 to 24

inches to the right of the white strip on the shoulder. All of these cracks seemed to be the result of

joint construction. The crack width was in the range of 5 to 15 mm. Longitudinal cracking was also

observed at a length of about 360 ft between the two lanes.

The other type of distress observed on the pavement section was minor to medium severity

raveling, mostly along the center of the lane. These were continuous stretches of raveled areas,

clearly showing loss of fine material at the surface.

Rutting

Average rutting was about 7 mm, with the left wheel path showing slightly larger rut depth

than the right wheel path (Figure 31 and Table 14). Overall, it can also be observed that at distances

closer to the intersection with SR 22, the rutting level is higher and as we move further from the

intersection, a decrease in rutting is observed.

53

Figure 31 Transverse profile at Huntingdon SR 522, southbound.

Table 14 Measured Rut Depth for Huntingdon SR 522, Southbound.

Rut Depth (mm)


0 10.0 9.5

200 6.5 8.0

400 6.5 5.0

600 7.0 3.5

800 8.0 4.5

Average 7.6 6.1

Std. Dev. 1.47 2.53

Travel

Lane

C.O.V. 19.4 41.6

Pictures showing general appearance of Huntingdon SR 522 are presented in Figure 32.

54

Figure 32 Pictures of Huntingdon SR 522 pavement.

55

SECTION 2: RESULTS FROM LABORATORY INVESTIGATION

The laboratory investigation was concentrated on determination of thicknesses and air voids

for both binder and wearing layers and determination of low temperature creep and strength for the

wearing layer. Details of the testing procedure were covered in a previous chapter. A summary of

layer thickness and air void for all cores is presented in Table 15.

Table 15 Thicknesses and Specific Gravities for Cores Tested Under WO-9.

Highway County Section Core # Gmm % Voids

Wearing Binder Wearing Binder Wearing WearingPG 64-28 1 39.2 46.4 2.451 2.477 2.567 4.5

2 43.7 N/A 2.487 N/A 2.567 3.14 38.5 N/A 2.501 N/A 2.567 2.65 36.9 55.2 2.476 2.437 2.567 3.56 33.7 43.7 2.500 2.497 2.567 2.67 33.8 60.0 2.451 2.403 2.567 4.58 36.3 57.5 2.484 2.433 2.567 3.2

PG 64-22 1 35.1 52.9 2.470 2.460 2.567 3.82 35.6 N/A 2.455 2.471 2.567 4.44 33.7 N/A 2.468 N/A 2.567 3.8

4p 35.5 N/A 2.459 N/A 2.567 4.25 41.0 N/A 2.467 2.390 2.567 3.96 38.7 52.6 2.493 2.472 2.567 2.98 39.6 54.4 2.416 2.426 2.567 5.9

MP 167 + 1350 ft 1 37.2 56.1 2.403 2.452 2.515 4.4MP 167 + 1350 ft 2 43.7 52.1 2.409 2.452 2.515 4.2MP 167 + 1350 ft 3 42.7 51.0 2.416 2.470 2.515 3.9MP 167.5 + 600 ft 4 34.0 51.5 2.417 2.472 2.515 3.9MP 167.5 + 600 ft 5 38.1 53.9 2.409 2.425 2.515 4.2

MP 168+691 ft 6 47.8 67.7 2.385 2.500 2.515 5.2MP 168 + 700 ft 7 47.2 66.5 2.402 2.502 2.547 5.7

MP 168.5 + 765 ft 9 50.8 71.3 2.400 2.456 2.515 4.6MP 169 + 700 ft 10 40.0 70.7 2.405 2.484 2.515 4.4

MP 167.5 + 700 ft 11 42.8 76.3 2.372 2.456 2.515 5.7MP 169 + 700 ft 12 39.4 78.6 2.390 2.457 2.515 5.0MP 169 + 700 ft 13 42.6 76.1 2.354 2.458 2.515 6.4

1 35.60 49.8 2.441 2.514 2.538 3.82 41.70 51.6 2.339 2.389 2.538 7.83 37.8 54.8 2.332 2.418 2.538 8.14 36.1 56.1 2.289 2.508 2.538 9.85 39.70 53.7 2.384 2.533 2.538 6.16 37.7 51.1 2.333 2.457 2.538 8.1

Bulk Specific Gravity

SR 522 Huntingdon

SR 153 Clearfield

I-80 Centre

mm GmbAvg. Layer Thickness

56

The results for the maximum theoretical specific gravity (Gmm) from laboratory testing of

cores versus design values are presented in Table 16. The results are comparable except the 19 mm

mix of Centre I-80 where lower Gmm is obtained from cores compared to design values.

Table 16 Comparison of Design and Measured Gmm for the Wearing Course

Highway County SectionDesign Cores

PG 64-22 2.571 2.5732.561

PG 64-28 2.571 2.570

12.5mm Mix 2.517 2.515

19mm Mix 2.600 2.5462.548

2.528 2.5302.5522.531

Clearfield

Centre

Huntingdon

SR 153

I-80

SR 522

Gmm

Low Temperature Creep and Strength Testing Results

Analysis of Cracking

Of all the sites visited, the ID2-section of Lycoming SR15 and PG 64-22 section of

Clearfield SR153 showed the highest level of cracking. While for both of these projects, most of the

cracking appeared to be fatigue related, there were areas of transverse cracks at both locations.

Since no IDT results were available for Clearfield, Centre I-80, and Huntingdon 522, cores from

these projects were used to complete such testing.

Lycoming SR 15: Original creep and strength testing for the Lycoming project was available

from indirect tensile tests (IDT) conducted on laboratory-prepared specimens during the WO-43

study. Among those selected for this research, the Lycoming SR 15 was the only project for which

IDT data were available from testing original materials. The master curve from creep compliance

results at -20ºC, -10ºC, and 0ºC is presented in Figure 33. A reference temperature of -10°C is used

to generate this graph. The figure indicates higher compliance of the Superpave mixture compared

57

to the ID-2 mixture. Higher compliance is an indication of better resistance against low temperature

cracking and fatigue cracking. Field observations indicated severe cracking of the ID-2 section

compared to the Superpave section where little cracking was observed. It should be noted that PG

64-22 binder was used in the ID-2 mix, while the Superpave mix contained a PG 64-28 binder.

1.00E-05

1.00E-04

1.00E-03

1.00E-02

1.00E-01

1.00E-02 1.00E+00 1.00E+02 1.00E+04 1.00E+06 1.00E+08

Reduced time(s)

D(t

) 1/M

pa

Superpave

Control (ID-2)

Reference -10°C

Figure 33 Creep Compliance versus reduced time for ID-2 and Superpave Sections at

Lycoming SR 153.

Clearfield SR 153: For the Clearfield SR 153, no IDT test results were available for the

original mixes, i.e., from materials at the time of construction. Therefore, during this project, IDT

creep and strength tests were conducted on cores collected at the time of pavement condition survey.

The tests were conducted to provide data needed to evaluate thermal cracking sensitivity of the

mixes. It is important to note that the results discussed here are for the cores from an aged 10-year-

old pavement; however, since both the PG 64-24 and PG 64-28 sections were subject to the same

climatic and traffic conditions, the results are comparable.

For the Clearfield SR 153, the IDT tests were conducted on six of the cores of the wearing

layers. Three cores from the PG 64-22 section and three from the PG 64-28 were used. The core

58

identification number and the pavement condition neighboring the core are shown in Table 17.

These two sections will be referred to as CR 64-28 and CR 64-22.

Table 17 SR 153 Cores Selected for IDT.

Core ID Pavement Section Condition

1 CR 64-28 Good

6 CR 64-28 Cracked

7 CR 64-28 Raveled

2 CR 64-22 Extension of Transverse Crack

5 CR 64-22 Good

6 CR 64-22 Cracked

The results are shown in Figures 34 through 43. The creep compliance master curve (at -

10ºC) and indirect tensile strength (at -10ºC) calculated for both sections are shown in Figure 38. It

is observed from this figure that, as expected, the PG 64-28 mix has higher compliance (lower

stiffness) than the 64-22 mix. This is consistent with observed level of cracking in the field. The

average tensile strength value is higher for the 64-28 mix (Figures 42 and 43). It should be noted that

the creep compliance master curve developed for each section was obtained as an average of three

replicates (AASHTO T322).

59

Creep compliance vs. Time (Clearfield 64-22)

0.00E+00

5.00E-05

1.00E-04

1.50E-04

2.00E-04

2.50E-04

3.00E-04

3.50E-04

1.00E-02 1.00E-01 1.00E+00 1.00E+01 1.00E+02Time(s)

D(t

) 1/M

pa-20C-10C0C

Figure 34 Creep compliance (1/MPa) vs. time(s) for CR 64-22.

Creep compliance mastercurve (Clearfield 64-22)

1.00E-05

1.00E-04

1.00E-03

1.00E-04 1.00E-02 1.00E+00 1.00E+02 1.00E+04Reduced time(s)

D(t

) 1/M

pa

Figure 35 Creep compliance (1/MPa) vs. reduced time(s) for CR 64-22.

60

Log shift factors vs Temperature (Clearfield 64-22)

y = -0.0034x2 - 0.2233x - 1.8908R2 = 1

-2.5

-2

-1.5

-1

-0.5

0

0.5

1

1.5

-25 -20 -15 -10 -5 0 5Temp (C)

Log

shift

fact

or

Figure 36 Log shift factors vs. temp for CR 64-28.

Creep compliance vs. Time (Clearfield 64-28)

0.00E+00

5.00E-05

1.00E-04

1.50E-04

2.00E-04

2.50E-04

3.00E-04

3.50E-04

4.00E-04

1.00E-02 1.00E-01 1.00E+00 1.00E+01 1.00E+02Time(s)

D(t

) 1/M

pa

-20C

-10C

0C

Figure 37 Creep compliance (1/MPa) vs. time(s) for CR 64-28.

61

Creep compliance mastercurve (Clearfield 64-28)

1.00E-05

1.00E-04

1.00E-03


D(t

) 1/M

pa

Figure 38 Creep compliance (1/MPa) vs. reduced time(s) for CR 64-28.

Log shift factors vs Temperature (Clearfield 64-28)

y = -0.0026x2 - 0.1849x - 1.5858R2 = 1

-2

-1.5

-1

-0.5

0

0.5

1

1.5

-25 -20 -15 -10 -5 0 5Temp (C)

Log

shift

fact

or

Figure 39 Log shift factors vs. temp for CR 64-28.

62

Creep compliance mastercurves -Clearfield

1.00E-05

1.00E-04

1.00E-03


D(t

) 1/M

pa

64-2864-22

Figure 40 Comparison of master curves of both sites on log-log domain.

63

Shift factor curves for Clearfield

y = -0.0034x2 - 0.2233x - 1.8908R2 = 1

y = -0.0026x2 - 0.1849x - 1.5858R2 = 1

-2.5

-2

-1.5

-1

-0.5

0

0.5

1

1.5

-25 -20 -15 -10 -5 0 5Temperature (C)

Log

shift

fact

or

64-22

64-28

Figure 41 Comparison of shift factor curves for both sites.

Table 18 Log Shift Factors for Both Sections at SR 153.

64-22 64-28

temp Log shift factors

-20 1.206 1.0598

-10 0 0

0 -1.891 -1.586

Table 19 Sigmoidal Coefficients for Both Sections at SR 153

64-22 64-28

a1 3.768 -2.223

a2 -40.539 -8.917

a3 4.959 4.366

a4 3.486 0.0627

a5 3.184 -1.722

a6 -0.365 -0.598

64

Tensile strength data (Clearfield 64-22)

0

0.5

1

1.5

2

2.5

3

3.5

4

4.5

core 2 core 5 core 6Core ID

Stre

ngth

(Mpa

)

Figure 42 Strength test results for CR 64-22.

Tensile strength data (Clearfield 64-28)

0

0.5

1

1.5

2

2.5

3

3.5

4

4.5

core 1 core 6 core 7Core ID

Stre

ngth

(Mpa

)

Figure 43 Strength test results for CR 64-28.

65

Huntingdon SR 522: Indirect tensile creep, strength, and resilient modulus tests were

conducted on three cores from Huntingdon SR 522, as shown in Table 20. Cores 1 and 2 were from

the same transverse section on the right wheel path and between the wheel paths, respectively. Core

5 is on the right wheel path, approximately 400 ft farther south from core 1.

Table 20 Huntingdon SR 522 Cores Selected for IDT.

Core ID Location Pavement Condition

1 Right Wheel Path Good

2 Between Wheel Path Minor Raveling

5 Right Wheel Path Good

The results of IDT tests are shown in Figures 44 through 47 and in Tables 21 and 22. The creep

compliance master curve (at -10ºC) and indirect tensile strength (at -10ºC) calculated for both

sections are shown in Figures 45 and 47, respectively. As shown in Figure 47, the Huntingdon SR

522 presents an asphalt concrete mix which has slightly a lower indirect tensile strength (and

possibly higher compliance) at low temperatures compared with the mixes used in Clearfield SR

153. Huntingdon SR 522 exhibited little cracking as discussed previously.

66

Creep compliance vs. Time (Huntington Core 1,2 and 5)

0.00E+00

1.00E-04

2.00E-04

3.00E-04

4.00E-04

5.00E-04

6.00E-04

7.00E-04

8.00E-04

9.00E-04

1.00E-03

1.00E-02 1.00E-01 1.00E+00 1.00E+01 1.00E+02Time(s)

D(t

) 1/M

pa

-20C

-10C

0C

Figure 44 Creep compliance vs. time – Huntingdon.

Creep compliance mastercurve (Huntington Core 1,2 and 5)

1.00E-05

1.00E-04

1.00E-03

1.00E-02


D(t

) 1/M

pa

Figure 45 Creep compliance vs. reduced time – Huntingdon.

67

Log shift factors vs Temp (Huntington - Core1,2 and 5)

y = -0.0001x2 - 0.1789x - 1.7758R2 = 1

-2

-1.5

-1

-0.5

0

0.5

1

1.5

2

-20 -18 -16 -14 -12 -10 -8 -6 -4 -2 0

Temp (C)

Log

shift

fact

or

Figure 46 Log shift factor curve – Huntington.

Table 21 Sigmoidal Coefficients – Huntington.

Core (1,2 and 5)

a1 11.907

a2 -70.517

a3 4.368

a4 0.0620

a5 -0.467

a6 -0.333

Table 22 Shift Factors – Huntington.

temp shift log shift

-20 56.224 1.750

-10 1 0

0 0.0168 -1.776

68

Strength Test (Huntington Core 1,2 and 5)

0

0.5

1

1.5

2

2.5

3

3.5

4

Core 1 Core 2 Core 5

Core ID

Stre

ngth

(Mpa

)

Figure 47 Indirect tensile strength test results– Huntington SR 522.

Table 23 Strength Test – Huntington.

Core #

Strength

(MPa)

1 3.115

2 2.856

5 2.680

Centre I-80: The indirect tensile creep and strength tests were also conducted on the cores

from the wearing layers of I-80 in Centre County. Five cores were used for testing. The core

identification number and locations are shown in Table 24. All cores appeared to be in a good shape.

69

Table 24 Details of Cores Selected for IDT from Centre I-80.

Core ID Location (mile + feet)

Nominal Maximum Aggregate Size. mm

10 MP 169+700 12.5

11 MP 169+700 12.5

12 MP 169+700 12.5

6 MP 168+691 19.0

7 MP 168+700 19.0

Cores 6 and 7 were from the 50-mm thick wearing course constructed with a 19 mm mix,

and cores 10, 11, and 12 were from the 40-mm thick wearing course constructed with a 12.5 mm

mix. The results of the tests are shown in Figures 48 through 57 and Tables 25 though 27.

Comparison of creep compliance between the 19 mm mix and 12.5 mm mix, as shown in Figure 54,

indicates that the 19 mm mix is a stiffer mix compared with the 12.5 mm mix. However, both are

more compliant than the mixes used in Clearfield SR 153, and this level of compliance is clearly the

reason for observing no cracks in this pavement after ten years of service. The indirect tensile

strength results indicate significant variability among cores. On the average, the 12.5mm mix

exhibits higher tensile strength than the 19mm mix.

70

Creep compliance vs. Time (I-80, Core 10,11 and 12)

5.00E-05

1.00E-04

1.50E-04

2.00E-04

2.50E-04

3.00E-04

1.00E-02 1.00E-01 1.00E+00 1.00E+01 1.00E+02Time(s)

D(t

) 1/M

pa

-20C

-10C

0C

Figure 48 Creep compliance vs. time for cores 10, 11, and 12 between MP 169 and 169.5 (I-80

Centre).

Creep compliance mastercurve (I-80, Core 10,11 and 12)

1.00E-05

1.00E-04

1.00E-03


D(t

) 1/M

pa

Figure 49 Creep compliance vs. reduced time for cores between MP 169 and 169.5 (I-80 Centre).

71

Log shift factors vs Temp (I-80 MP 169-169.5)

y = -0.0019x2 - 0.1836x - 1.6466R2 = 1

-2

-1.5

-1

-0.5

0

0.5

1

1.5

-20 -18 -16 -14 -12 -10 -8 -6 -4 -2 0

Temp (C)

Log

shift

fact

or

Figure 50 Log shift factor vs. temp for cores 10, 11, and 12.

Creep compliance vs. Time (I-80 , core 6 and 7)

5.00E-05

7.00E-05

9.00E-05

1.10E-04

1.30E-04

1.50E-04

1.70E-04

1.90E-04

2.10E-04

2.30E-04

2.50E-04

1.00E-02 1.00E-01 1.00E+00 1.00E+01 1.00E+02Time(s)

D(t

) 1/M

pa

-20C

-10C

0C

Figure 51 Creep compliance vs. time for cores 6 and 7 between MP 168 and 168.5

(I-80 Centre).

72

Creep compliance mastercurve (I-80, core 6 and 7)

1.00E-05

1.00E-04

1.00E-03

1.00E-03 1.00E-02 1.00E-01 1.00E+00 1.00E+01 1.00E+02 1.00E+03 1.00E+04Reduced time(s)

D(t

) 1/M

pa

Figure 52 Creep compliance vs. reduced time for cores between MP 168 and 168.5

(I-80 Centre).

73

Log shift factors vs Temp (I-80-MP 168-168.5)

y = -0.0048x2 - 0.2313x - 1.8283R2 = 1

-2

-1.5

-1

-0.5

0

0.5

1

-20 -18 -16 -14 -12 -10 -8 -6 -4 -2 0

Temp (C)

Log

shift

fact

or

Figure 53 Log shift factor vs. temp for cores 6 and 7.

Creep compliance mastercurves (I-80)

1.00E-05

1.00E-04

1.00E-03

1.00E-04 1.00E-03 1.00E-02 1.00E-01 1.00E+00 1.00E+01 1.00E+02 1.00E+03 1.00E+04Reduced time(s)

D(t

) 1/M

pa

Core 6 7

Core 10 11 12

Figure 54 Comparison of master curves for I-80.

74

Shift factor curves for I-80

y = -0.0019x2 - 0.1836x - 1.6466R2 = 1

y = -0.0048x2 - 0.2313x - 1.8283R2 = 1

-2

-1.5

-1

-0.5

0

0.5

1

1.5

-25 -20 -15 -10 -5 0

Temperature (C)

log

shift

fact

or Core 6 and 7

Core 10,11 and 12

Figure 55 Comparison of shift factors (I-80).

75

Strength Test (I-80-MP 169-169.5)

2.7

2.8

2.9

3

3.1

3.2

3.3

Core 10 Core 11 Core 12

Core ID

Stre

ngth

(Mpa

)

Figure 56 Strength values for cores between MP 169 and 169.5.

Strength test (I-80-MP 168-168.5)

2.3

2.4

2.5

2.6

2.7

2.8

2.9

3

Core 6 Core 7

Core ID

Stre

ngth

(Mpa

)

Figure 57 Strength values for cores between MP 168 and 168.5.

76

Table 25 Strength Values for All Cores in I-80.

Core #

Strength

(MPa)

10 2.930

11 2.961

12 3.257

6 2.578

7 2.727

Table 26 Log Shift Factors for All Cores in I-80.

MP 169-169.5 MP 168-168.5

Core (10,11,12) Core (6,7)

Temp.,

ºC log shift

-20 1.276 0.979

-10 0 0

0 -1.646 -1.802

Table 27 Sigmoidal Coefficients for All Cores in I-80.

MP 169-169.5 MP 168-168.5

Core (10,11,12) Core(6,7)

a1 5.367 -0.374

a2 -48.631 -26.798

a3 5.097 6.968

a4 0.439 2.343

a5 1.999 2.443

a6 -0.472 -0.476

77

Results from Resilient Modulus Testing

It was mentioned previously that the resilient modulus testing was conducted on cores from

Huntingdon SR 522 and Centre I-80. These tests were performed on the same cores that were used

for IDT strength and creep discussed previously.

The resilient modulus values for the cores tested for Centre I-80 and Huntingdon SR 522 are

shown in Tables 28 and 29, respectively.

Table 28 Results of Resilient Modulus Test for Centre I-80.

Core

#

Resilient modulus

(MPa)

10 12089

11 10237

12 13990

6 9554

7 13590

The two cores tested from the 19 mm mix of Centre I-80 (cores 6 and 7) showed significant

variability. On the average, the modulus values from 19 mm mix and the 12.5 mm mix are

comparable. The resilient modulus values for Huntingdon SR 522 were significantly lower than

those of Centre I-80. The recovered binders from these two sites exhibit very different values for

complex modulus, with the Centre I-80 binder being considerably stiffer than the binder of SR 522,

as shown in Table 32. Significant difference in binder stiffness has certainly affected the difference

observed in resilient modulus of the mixes.

Table 29 Results of Resilient Modulus Test for Huntingdon SR 522.

Core # Resilient Modulus (MPa)

1 4327

2 4792

5 3870

Results form PSPA Tests

Due to resource limitations, Huntingdon SR 522 was the only site where PSPA testing was

conducted. Such testing was not part of the original testing plan but was conducted to obtain

78

additional data regarding pavement modulus at this site. All seismic tests were performed on

11/08/2007.

Seismic data were collected at different locations along the pavement: left wheel path

(LWP), right wheel path (RWP), and centreline (C) of travel lane. Coring areas were also included

during PSPA testing. For each testing location, PSPA tests were conducted in both longitudinal and

transverse orientation. The longitudinal orientation is parallel to the traffic direction, while the

transverse orientation is perpendicular. Finally, at least three measurements were obtained at

additional locations at distances about 300 to 500 feet from the survey start point. Pavement surface

temperature was recorded for each PSPA measurement. Summarized PSPA data are tabulated in

Tables 30. The average seismic modulus of binder layer was found to be approximately 9000 MPa

In general, a good structural uniformity was observed throughout the pavement section. In other

words, seismic modulus does not vary significantly from one testing location to another. It should be

noted that, in most cases, testing at centreline yields lower seismic moduli than wheel paths (LWP

and RWP). One possible explanation of this observation is the material densification in wheel paths

due to traffic.

79

Table 30 Results of PSPA Testing at Huntingdon SR 522

Modulus Pav. Temp Modulus Pav. TempMPa oC MPa oC

Core 1 RWP Longitudinal 8678 25 300 ft C Transverse 8079 27Core 1 RWP Longitudinal 8671 25 300 ft C Transverse 8100 27Core 1 RWP Longitudinal 8765 25 300 ft C Transverse 8136 27Core 1 RWP Transverse 8817 26 300 ft LWP Longitudinal 8686 27Core 1 RWP Transverse 8962 26 300 ft LWP Longitudinal 8701 27Core 1 RWP Transverse 10003 26 300 ft LWP Longitudinal 8729 27Core 2 BWP Longitudinal 11389 26 300 ft LWP Transverse 7954 27Core 2 BWP Longitudinal 11295 26 300 ft LWP Transverse 7791 27Core 2 BWP Longitudinal 11299 26 300 ft LWP Transverse 7796 27Core 2 BWP Transverse 10801 26 334 ft RWP Longitudinal 9953 27Core 2 BWP Transverse 10843 26 334 ft RWP Longitudinal 9956 27Core 2 BWP Transverse 10822 26 334 ft RWP Longitudinal 9975 27Core 3 LWP Longitudinal 8450 26 334 ft RWP Transverse 8439 27Core 3 LWP Longitudinal 8439 26 334 ft RWP Transverse 8316 27Core 3 LWP Longitudinal 8503 26 334 ft RWP Transverse 8103 27Core 3 LWP Transverse 7955 26 334 ft Center Longitudinal 8475 27Core 3 LWP Transverse 8003 26 334 ft Center Longitudinal 8530 27Core 3 LWP Transverse 8024 26 334 ft Center Longitudinal 8581 27Core 4 Center Longitudinal 8140 25 334 ft Center Transverse 8253 27Core 4 Center Longitudinal 8199 25 334 ft Center Transverse 8250 27Core 4 Center Longitudinal 8227 25 334 ft Center Transverse 8319 27Core 4 Center Transverse 7536 25 454 ft RWP Longitudinal 10311 27Core 4 Center Transverse 7488 25 454 ft RWP Longitudinal 10170 27Core 4 Center Transverse 7501 25 454 ft RWP Longitudinal 10160 27Core 5 RWP Longitudinal 9220 24 454 ft RWP Transverse 8573 27Core 5 RWP Longitudinal 9232 24 454 ft RWP Transverse 8625 27Core 5 RWP Longitudinal 9221 24 454 ft RWP Transverse 8653 27Core 5 RWP Transverse 8907 25 454 ft Center Longitudinal 7340 27Core 5 RWP Transverse 8929 25 454 ft Center Longitudinal 7366 27Core 5 RWP Transverse 8933 25 454 ft Center Longitudinal 8145 27Core 6 LWP Longitudinal 6872 27 454 ft Center Transverse 7805 27Core 6 LWP Longitudinal 6867 27 454 ft Center Transverse 7834 27Core 6 LWP Longitudinal - 27 454 ft Center Transverse 7801 27Core 6 LWP Transverse 8148 27 454 ft LWP Longitudinal 11994 27Core 6 LWP Transverse 8154 27 454 ft LWP Longitudinal 12273 27Core 6 LWP Transverse 8150 27 454 ft LWP Longitudinal 11922 27300 ft RWP Longitudinal 11223 27 454 ft LWP Transverse 11358 27300 ft RWP Longitudinal 11238 27 454 ft LWP Transverse 11280 27300 ft RWP Longitudinal 11219 27 454 ft LWP Transverse 11274 27300 ft RWP Transverse 10503 27 500 ft - Longitudinal 7114 27300 ft RWP Transverse 10510 27 500 ft - Longitudinal 7107 27300 ft RWP Transverse 10497 27 500 ft - Longitudinal 7052 27300 ft Center Longitudinal 7898 27 500 ft - Transverse 7496 27300 ft Center Longitudinal 8861 27 500 ft - Transverse 8244 27300 ft Center Longitudinal 9142 27 500 ft - Transverse 8031 27

RWP: Right Wheel Path Average Modulus, Mpa 8962LWP: Left Wheel Path Std. Dev., Mpa 1355

OrientationLocation LocationLocation Location Orientation

80

Analysis of Rutting Data

The tables on rutting presented previously contain the peak magnitude of rut depth for both

left and right wheel paths. The lowest reported rutting is about 2 mm (Centre I-80 right lane) and

the highest 11 mm (Lycoming SR 15, southbound). The average rutting for right wheel path was 5.4

mm and 6.4 mm for right wheel path and left wheel path, respectively, when all surveyed sites are

considered. In addition, in most cases, the rutting in the left wheel path exceeds that of the right

wheel path; however, for one-third of the cases, the opposite is true.

The rutting data indicates that almost all projects are performing satisfactorily in this regard.

We have adopted the following ranges to categorize pavement performance in terms of rutting:

• 0 < rut < 5 mm: Excellent Performance • 5 < rut < 10 mm: Acceptable Performance • 10 < rut < 15 mm: Marginal Performance • rut > 15 mm: Poor Performance

Considering this definition, performance of most sites is in the excellent or acceptable range

(Figure 58). The only two sections with marginal performances would be the travel lane of the

Snyder SR 11 (at the proximity of the 11th Street) and the travel lane of the full-depth construction

Superpave mix on the southbound lane of Lycoming SR15. For Snyder, the obvious reason is slow-

moving traffic close to the intersection causing excessive rutting. The data for this site indicate that

as we move farther from the intersection, rutting is reduced. Among the sites presented in Figure 58,

the full-depth construction Superpave mix of the Lycoming SR15 did indicate the highest level of

shear strain in the Superpave shear tester.

81

Snyd

er S

R 1

1 Pa

ssin

g La

ne

Snyd

er S

R 1

1 Tr

avel

Lan

e N

orth

of 1

1th

St.

Snyd

er S

R 1

1 Tr

avel

Lan

e N

orth

of M

ill R

d.

Lyco

min

g SR

15

Nor

th B

ound

ID2

Lyco

min

g SR

15

Nor

th B

ound

Sup

erpa

ve

Lyco

min

g SR

15

Sout

h B

ound

Sup

erpa

ve O

ver C

oncr

ete

Lyco

min

g SR

15

Sout

h B

ound

Sup

erpa

ve-F

ull D

epth

Lyco

min

g SR

15

Nor

th B

ound

Sou

th o

f Tio

ga B

orde

r Sig

n

Lyco

min

g SR

15

Nor

th B

ound

Nor

th o

f Tio

ga B

orde

r Sig

n

Cen

tre I-

80 M

P 16

7.0

to 1

67.5

Cen

tre I-

80 M

P 16

7.5

to 1

68.0

Cen

tre I-

80 M

P 16

8.0

to 1

68.5

Cen

tre I-

80 M

P 16

8.5

to 1

69.0

Cen

tre M

P 16

9.0

to 1

69.5

Cle

arfie

ld S

R 1

53 P

G 6

4-22

Cle

arfie

ld S

R 1

53 P

G 6

4-28

Hun

tingd

on S

R 5

22 T

rave

l Lan

e

0

5

10

15

20R

ut D

epth

, mm

Proposed Guide:0<rut<5 mm: EXCELLENT5<rut<10 mm: ACCEPTABLE10<rut<15 mm: MARGINALrut>15 mm: POOR

Figure 58 Measure rut depth at different sites.

Table 31 is presented in an attempt to compare the results of the laboratory shear tests to the

Superpave shear tester (SST) and the observed field rutting. The laboratory tests were the constant

height repeated shear tests (CHRST) conducted at 52ºC during the WO-43 project. Figure 59

presents the relationship between shear strain at an equivalent number of cycles versus rut depth.

No clear trend is observed, indicating the impact of other factors that are not included in the

analysis. Such factors include the rate of loading (higher truck speed on SR 15 versus SR 153), the

grade effect (higher slope at SR 153 compared to SR 153), and temperature differences. At best, we

could conclude that the laboratory shear strain values under 1 percent result in acceptable rutting

level in the field.

82

Table 31 Shear Test Results for Cored Projects and Correspondence with Measured Field Rut Depth.

Specimen Air Voids,

%

Lycoming 3,058 4808 SuperPave Wearing Course, 12.5 mm, RPS, SRL-H 64-22 1.13 3 0.18 1.13

0015 - B43 Bituminous Concrete Base Course 64-22 0.51 3 0.2 0.5ID-2 Bituminous Concrete Binder Course 64-22 0.96 7 0 0.95ID-2 Bituminous Concrete Wearing Course 64-22 0.43 3 0.26 0.42 5.5

Lycoming 4,054 6820 SuperPave Wearing Course, 12.5 mm, RPS, SRL-H 64-28 0.96 3 0.23 1.02 8.0

0015 - B42 032200 SuperPave Wearing Course, 12.5 mm, RPS, SRL-H 64-22 1.04 3 0.14 1.08SuperPave Wearing Course, 12.5 mm, RPS, SRL-E 64-22 0.72 3 0.17 0.76

Snyder 7,304 14152 SuperPave Wearing Course, 19 mm, RPS, SRL-E* 64-22 0.69 3 0.12 0.78 6.5

0011 - 38M SuperPave Wearing Course, 19 mm, RPS, SRL-E ** 76-22 0.56 3 0.14 0.65 7.0

Clearfield 1,000 1202 SuperPave Wearing Course, 12.5 mm, RPS, SRL-G 64-28 0.41 3 0.17 0.32 9.5

0153-225 64-28 0.46 3 0.23 0.33SuperPave Binder Course, 64-22 0.63 3 0.14 0.5225 mm 64-22 2.01 7 0.34 1.24

Maximum Average Field Measured Rut,

mmPENNDOT ProjectESALS

(Thousands)

No. of shear strain cycles equivalent to

ESALS Pavement Course PG Grade

Permanent Shear Strain after 5000

cycles

Slope of shear

deformation vs. Cycles

Curve

Permanent Shear Strain

after equivalent

cycles

83

0

2

4

6

8

10

0 0.2 0.4 0.6 0.8 1 1.2 1.4Shear Strain from Constant Height Repeated Shear Test, %

Mea

sure

d R

ut D

epth

, mm

Figure 59 Rut Depth versus CHRST permanent shear strain of the wearing layer.

Investigation of Aging in Superpave Binders

The goal of this research project was validation of the Superpave system through field

investigation. As part of accomplishing this objective, an investigation was made into the level of

aging observed in the field and how this aging compares with laboratory-simulated aging with the

pressure aging vessel (PAV). Such comparative analysis was conducted for those projects from

which cores were available. That includes Clearfield SR 153 and Huntingdon SR 522. For the

Centre I-80 project, complex modulus was determined for the recovered binder from field cores but

no comparison could be made with PAV data since no such data was available.

The binders recovered from field cores were tested with the dynamic shear rheometer (DSR) at

high and intermediate temperatures. The modulus results for both recovered binder and PAV-aged

binder are presented in Table 32 and Figures 60 through 63.

84

Table 32 Comparing Modulus of Binder from PAV Simulation with That of Field Cores.

County Highway Specimen IDTest

Temp. oC

Binder Modulus From Lab PAV Simulation, kPa

Binder Modulus From Field Cores

Test, kPa

Aging Ratio (Field/PAV)

25 8,762.8 4,431.9 0.5128 5,637.6 2,820.2 0.5031 3,551.8 1,642.9 0.46

22 6,437.5 3,308.3 0.5125 4,068.4 2,018.9 0.5028 2,568.1 1,350.4 0.53

22 4,970.0 3,624.0 0.7325 2,272.228 2,060.0 1,380.2 0.6731 858.2

22 4,970.0 5,695.2 1.1525 3,857.728 2,060.0 2,561.7 1.2431 1,678.0

22 8,018.425 5,366.428 3,116.231 1,766.8

22 11,441.025 9,618.328 7,506.031 4,384.6

(1) Data from Testing of Original Binder for Centre I-80 is not available and therefore not presented.

Core # 7, 19mm Mix

Core # 6, 19 mm Mix

PG 64-22 Core # 2

PG 64-28 Core # 1

Core # 1

Core # 2

Centre(1) I-80

Clearfield SR-153

Huntingdon SR-522

85

0

1,000

2,000

3,000

4,000

5,000

6,000

7,000

25ºC 28ºC 31ºC

PAV

Fiel

d

Clearfield, SR 153, PG 64-28 Section

Bin

der M

odul

us, k

pa

Figure 60 Binder modulus for Clearfield SR 153-PG 64-28 from PAV simulation and field

cores.

0

1,0002,000

3,0004,000

5,000

6,0007,000

8,0009,000

10,000

25ºC 28ºC 31ºC

PG 6

4-22

PG 6

4-28

Clearfield, SR 153, PG 64-28 vs PG 64-22, PAV Simulation

Bin

der M

odul

us, k

pa

Figure 61 Binder modulus for Clearfield SR 153-PAV simulation: PG 64-28 versus PG 64-28.

86

0500

1,0001,500

2,0002,500

3,0003,500

4,0004,500

5,000

25ºC 28ºC 31ºC

PG 6

4-22

PG 6

4-28

Bin

der M

odul

us, k

pa

Clearfield, SR 153, PG 64-28 vs PG 64-22, Field Cores

Figure 62 Binder modulus for Clearfield SR 153 field cores: PG 64-28 versus PG 64-28.

0

1,000

2,000

3,000

4,000

5,000

6,000

22ºC 28ºC

PAV

Fiel

d C

ore

#2Huntingdon SR 522

Bin

der M

odul

us, k

pa Fiel

d C

ore

#1

Figure 63 Binder modulus for Huntingdon SR 522 PAV simulation versus field cores.

The results indicate that for both PG 64-28 and PG 64-22 sections at Clearfield SR 153, the

PAV simulation provided a significantly higher aging level (stiffer binder) compared with actual

aging observed in the field for a 10-year-old pavement. The field aging is approximately 50 percent

of PAV simulation aging for both sections, indicating the same aging rate for both binders. The PG

64-22 binder was stiffer than the PG 64-28 binder to begin with, and this original difference in

stiffness is manifested in the modulus results obtained for PAV-simulated aging and the field aging.

87

For the Huntingdon SR 522 with an original PG 64-28 binder, the field-aged binder is closer

to the PAV-aged binder for this 9-year-old pavement. The binder recovered from the wheel path

core (core #1) shows approximately 30 percent lower stiffness than the PAV-aged binder (i.e., lower

aging level). The binder from between the wheel path core (core #2) has about 20 percent higher

modulus than the PAV-aged binder (i.e., higher aging level). The air voids for these cores are 3.5

percent and 8.3 percent, respectively. The significantly higher air void level of core #2 (between the

wheel path core) could have contributed to the higher level of aging observed for the binder of this

core. A third core was also extracted, but during the binder recovery, the retaining clip broke on the

evaporator and the sample spilled out, causing loss of the binder.

88

CHAPTER FOUR SUMMARY AND CONCLUSIONS

The results presented in this report demonstrate the outcome of a two-year study by the

Northeast Center of Excellent Technology (NECEPT) at The Thomas D. Larson Pennsylvania

Transportation Institute on field performance of Superpave hot-mix asphalt concrete. Sponsored by

the Pennsylvania Department of Transportation, this study was initiated to complement the efforts

and findings from an earlier study known as “Superpave Validation Studies” (Work Order 43) and to

address PennDOT concerns regarding performance of these Superpave mixes. Six 9- and 10-year-

old pavements were evaluated to assess their condition. These included some of the pavements

considered under Work Order 43. Time constraints and difficulties in scheduling prevented

evaluation of three other pavements that were originally planned to be included in the study.

A detailed pavement condition evaluation was conducted and a series of laboratory tests were

performed on cores obtained from three of these pavements. Pavement condition evaluation

consisted of determination of magnitude and type of cracking as well as transverse profiling to

determine the rutting magnitude. Major laboratory tests on cores included specific gravity

measurements, indirect tensile resilient modulus, indirect tensile creep and strength, extraction and

binder recovery, and finally, determination of the binder dynamic modulus.

The results were evaluated to address two questions: (1) What is the quality of these

pavements after 10 years of service? and (2) How do the laboratory results relate with observed

performance of these pavements?

The answer to the first question is that most of the pavements appeared to be in relatively

good condition. Rutting level was within acceptable range and cracking was minimal. No

significant bleeding or raveling was observed. Exceptions to decent performance of such mixes

were the PG 64-22 pavement section at Clearfield SR 153 and the ID-2 section on the northbound of

Lycoming SR 15. These two pavement sections had the most dominant cracking.

The average rutting was 5.4 mm and 6.4 mm for right wheel path and left wheel path,

respectively, when all projects were considered. The lowest measured rutting was about 2 mm

(Centre I-80 right lane) and the highest 11 mm (Lycoming SR 15, southbound).

Beyond observed distresses as discussed above, the major concern was the longitudinal joint

between the lanes which, in most cases, was cracked for a very long stretch of the road, sometimes

89

very severely.

To answer the second question, laboratory tests were performed on cores. In addition, to the

extent that the Work Order 43 laboratory data were available for the projects evaluated under Work

Order 9, those results were used to determine the relationship between laboratory results and field

performance.

Laboratory rutting tests (constant height repeated shear test at 52 ºC) on wearing course did

not deliver a good correlation with rutting levels observed, but the data provide a guide as to the

range of laboratory strain levels that could result in acceptable rutting levels. Unfortunately,

sufficient laboratory shear strain data were not available for the binder course of all pavements

surveyed, and it did not become possible to investigate the relationship between the rutting level and

the laboratory test results for the binder layer. Based on the results from shear tests on wearing

course mixes, it could be concluded that the laboratory shear strain values under 1 percent, when

tested for 5,000 cycles at 52 ºC, result in an acceptable rutting level in the field.

For the two pavement sections with the most cracking (PG 64-22 of Clearfield SR 153 and

ID-2 section of Lycoming SR 15), laboratory tests of indirect creep at low temperatures indicated

lower compliance of these two mixes compared to their companion sections. For the SR 153 project,

low temperature creep tests were conducted on cores, whereas for SR 15 no cores were obtained and

results from the original Work Order 43 low temperature creep tests were used for comparison.

An investigation was also made into the level of aging observed in the field and how this

aging compares with laboratory-simulated aging. Such comparative analysis was conducted for

those projects from which cores were available. That includes Clearfield SR 153 and Huntingdon

SR 522. For the Centre I-80 project, complex modulus was determined for the recovered binder

from field cores but no comparison could be made with PAV data, since no such data were available.

The results indicated that for both PG 64-28 and PG 64-22 sections at Clearfield SR 153, the PAV

simulation provided a significantly higher aging level (stiffer binder) compared with actual aging

observed in the field for a 10-year-old pavement. For the Huntingdon SR 522 with an original PG

64-28 binder, the field-aged binder is closer to the PAV-aged binder for this 9-year-old pavement.

However, the wheel path core indicated lower stiffness than the PAV simulation, while the between-

wheel-path core indicted higher aging. Significantly higher air void level of between-wheel-path

core could have contributed to the higher level of aging observed for the binder of this core.

This study provided invaluable information regarding long-term performance of Superpave

90

mixes. Detailed field distress information and laboratory tests on cores provided a unique

opportunity to compare test results with observed performance.

91

REFERENCES

Brown, E. R., and M. S. Buchanan, “Superpave Gyratory Compaction Guidelines,” NCHRP Research Results Digest 23, 1999. Kandhal, P. S., and L. A. Cooley, Jr., “The Restricted Zone in the Superpave Aggregate Gradation Specification,” National Cooperative Highway Research Program, NCHRP report 464, Washington, DC, 2001. 464 Anderson, D.A., M. Solaimanian, D. Christensen, M. Marasteanu, and D. Hunter, “Superpave Validation Studies,” Pennsylvania Transportation Institute, Report PTI 2003-14, January 2003. Goel, A and A. Das, “A Brief Review on Different Surface Wave Methods and Their Applicability for Non- Destructive Evaluation of Pavements.” Proceedings of Highway Geophysics – NDE, St. Louis, MO, 2006. Nazarian, S. and K. H. Stokoe, “Nondestructive Testing of Pavements Using Surface Waves.” Transportation Research Record 993, National Research Council, Washington, D.C. 1984. Nazarian, S, Baker, MR, and Crain, K., “Fabrication and Testing of a Seismic Pavement Analyzer,” SHRP Report H-375. National Research Council, Washington, D.C., 1993. Nazarian, S, Baker, M, and Crain, K., “Assessing Quality of Concrete with Wave Propagation Techniques,” Materials Journal, Vol. 94, No. 4. American Concrete Institute, MI. 1997. Christensen, D.W., and R. F. Bonaquist, “Evaluation of Indirect Tensile Test (IDT) Procedures for Low-Temperature Performance of Hot Mix Asphalt,” NCHRP Report 530, Transportation Research Board, National Research Council, Washington, DC, 2004. Barksdale, R.B., J. Alba, R. Kim, P. Khosla, and M.S. Rahman, “Laboratory Determination of Resilient Modulus for Flexible Pavement Design,” NCHRP Web Document 14, 1997.

APPENDIX

A

Inventory of Data and Materials from PennDOT WO-43 Project

A-2

Table A.1 Available Binder and Mixture Data from PennDOT WO-43 Project.

Specified Pavement Courses Vol

. Ana

lysi

sFr

eq. S

wee

pR

ep. S

hear

IDT

DSR

- T

ank

DSR

- R

TFO

TB

BR

- PA

VD

T -

PAV

0322-08M Crawford Superpave Wearing Course, 12.5 mm, RPS, SRL-H 38 58-28 √ √ √ √

Superpave Binder Course, 25 mm leveling >50 58-28 √ √ √ √

1-0 (2)

0062-12M Warren Superpave Wearing Course, 12.5 mm, SRL-E 38 64-22

Superpave Binder Course, 25 mm leveling 64-22

Superpave Wearing Course, 12.5 mm, SRL-G (scratch layer) 38 64-22√

Superpave Wearing Course, 12.5 mm, RPS, SRL-G (southern segment) 38 64-22√

Superpave Wearing Course, 12.5 mm, RPS, SRL-G (northern segment) 38 64-28√ √ √

Superpave Binder Course, 25 mm (for all) 50 64-22√ √ √ √ √ √ √

2-0 (4)

0080-B22 Centre

Wearing, Binder, and Base 64-28√ √ √ √

2-0 (5)

0080- Base Asphalt (AC-20)√ √ √ √

Clearfield Base Asphalt + Novophalt√ √ √ √

Base + Polybilt√ √ √ √

Base + Kraton√ √ √ √

Base + Styrelf√ √ √ √

Base + Gilsonite√ √ √ √

Superpave Wearing Course, 12.5 mm, RPS, SRL-H (South Bound, Overlay) 38 64-22√ √ √ √ √ √ √ √

Superpave Binder Course, 25 mm, RPS (South Bound, Overlay) 75 64-22√ √ √ √ √ √ √

Superpave Binder Course, 19 mm, Leveling (South Bound, Overlay) 64-22√ √ √ √ √ √ √

Bituminous Concrete Base Course (North Bound, Full Depth) 64-22√ √ √ √ √ √

ID-2 Bituminous Concrete Binder Course (North Bound, Full Depth) 64-22√ √ √ √ √ √

ID-2 Bituminous Concrete Wearing Course (North Bound, Full Depth) 64-22√ √ √ √ √ √ √

Dep

th (

mm

)

S.R.-Sec. Co.County

1-0 (1)

Mixture Tests

0153 - 225 Clearfield

2-0(3)

0015 - B43 Lycoming

3-0(6)

Dis

tric

t

PG B

inde

r G

rade

Binder Tests

A-3

Table A.1 Available Binder and Mixture Data from PennDOT WO-43 Project. (continued).


. Ana

lysi

sFr

eq. S

wee

pR

ep. S

hear

IDT

DSR

- T

ank

DSR

- R

TFO

TB

BR

- PA

VD

T -

PAV

Superpave Wearing Course, 12.5 mm, RPS, SRL-H (North Bound, Full Depth) 64-28√ √ √ √

Superpave Wearing Course, 12.5 mm, RPS, SRL-H (North Bound, Full Depth) 70-28

Superpave Wearing Course, 12.5 mm, RPS, SRL-H (North Bound, Full Depth) 64-22√ √ √ √ √ √ √

Superpave Binder Course, 25 mm, RPS(North Bound, Full Depth) 58-28√ √ √ √

Superpave Binder Course, 19 mm, Leveling 64-22√ √

Superpave Base Course, 37.5 mm, RPS(North Bound, Full Depth) 150 58-28√ √ √ √ √ √ √ √

Superpave Base Course, 37.5 mm, RPS(North Bound, Full Depth) 250 58-28√ √

Superpave Wearing Course, 12.5 mm, RPS, SRL-E 64-22√ √ √

Superpave Binder Course, 25 mm 64-22√ √ √

Superpave Wearing Course, 19 mm, RPS, SRL-E * 100 64-22√ √ √ √ √ √

Superpave Wearing Course, 19 mm, RPS, SRL-E ** 100 76-22M√ √ √

Superpave Binder Course, 25 mm, RPS 150 64-22√

Superpave Wearing Course, 12.5 mm, RPS, SRL-E * 64-22√ √ √ √ √ √

Superpave Wearing Course, 12.5 mm, RPS, SRL-E ** 76-22√ √

Superpave Intermediate Course, 19 mm, RPS, SRL-L * 64-22√

Superpave Intermed Course, 19 mm, RPS, SRL-L ** 76-22√

Gyratory Wearing Course, 19 mm, RPS, SRL-E 50 70-28 (Tyrsolv)

Gyratory Wearing Course, 19 mm, RPS, SRL-E 50 70-28M

3-0(8)

0081 - 050 Schuykill

5-0 (9)

Dis

tric

t

S.R.-Sec. Co.County

0015 - B42 Lycoming

032200

3-0(7)

0011 - 38M Snyder

Dep

th (

mm

)

PG B

inde

r G

rade

Mixture Tests

Binder Tests

A-4



. Ana

lysi

sFr

eq. S

wee

pR

ep. S

hear

IDT

DSR

- T

ank

DSR

- R

TFO

TB

BR

- PA

VD

T -

PAV

5-0 (10)

0061-10M Berks Superpave Wearing Course, 12.5 mm, RPS, SRL-E

38 70-22

Superpave Wearing Course, 12.5 mm, SRL-L, Levelling64-22

Superpave Wearing Course, 12.5 mm, SRL-L<50 64-22

√ √

Superpave Wearing Course, 19 mm, SRL-L>50 64-22

√ √

Superpave Binder Course, 25 mm, RPS50 64-22

Superpave Binder Course, 25 mm, PG 70-22, RPS63 64-22

Superpave Wearing Course, 12.5 mm, SRL-M*64-22

Superpave Wearing Course, 19 mm, SRL-M**64-22

6-0 (11)

0132-M00 Bucks Superpave Wearing Course, 19 mm, RPS, SRL-E

38 70-22

Superpave Binder Course, 25 mm, RPS63 64-22

6-0 (12)

0132-M01 Bucks Superpave Wearing Course, 19 mm, RPS, SRL-E

38 64-22

Superpave BinderCourse, 25 mm, RPS63 64-22

8-0(13)

0083 - 832 York

Superpave Wearing Course, 19 mm, RPS, SRL-E 50 76-22√ √ √ √ √ √

Superpave Binder Course, 25 mm, RPS 50 64-22√ √ √ √ √ √

Superpave Binder Course, 25 mm, Leveling 64-22√ √ √ √ √ √

Superpave Base Course, 37.5 mm 175 64-22√ √ √ √ √ √ √

Superpave Base Course, 37.5 mm 64-22√ √ √ √ √ √ √

Mixture Tests

Binder Tests

Dis

tric

t

S.R.-Sec. Co.County D

epth

(m

m)

PG B

inde

r G

rade

A-5



. Ana

lysi

sFr

eq. S

wee

pR

ep. S

hear

IDT

DSR

- T

ank

DSR

- R

TFO

TB

BR

- PA

VD

T -

PAV

8-0 (14)

0011-024 Franklin

Superpave Wearing Course, 12.5 mm, Section 1, SB/SBS 76-22√ √ √ √ √ √

Superpave Wearing Course, 12.5 mm, Section 2, Elvaloy 76-22√ √ √ √ √ √

Superpave Wearing Course, 12.5 mm, Section 3, Fibers 64-22√ √ √ √ √ √

Superpave Wearing Course, 12.5 mm, Section 4, Oxidized 76-22√ √ √ √

Superpave Wearing Course, 12.5 mm, Section 5, Neat 64-22

8-0 (15)

0030-B01 York

Superpave Wearing Course, 19 mm, SRL-E 76-22√ √ √ √

Superpave Binder Course, 25 mm 64-22√ √ √ √

Superpave Base Course, 37.5 mm 64-22√ √ √ √

9-0(16)

0070 - 009 Fulton

Superpave Wearing Course, 12.5 mm, RPS, SRL-H 38 64-22√ √ √ √ √ √ √ √

Superpave Wearing Course, 12.5 mm, RPS, SRL-H 38 70-28 (Tyrsolv) √

Superpave Wearing Course, 12.5 mm, RPS, SRL-H 50 70-28 (Tyrsolv)

Superpave Binder Course, 25 mm, RPS 50 64-22√ √

Stone Matrix Asphalt Wearing Course, SRL-H 50

Superpave Wearing Course, 12.5 mm, SRL-L√ √ √ √

9-0(17)

6522 - 001 Huntingdon

Superpave Wearing Course, 12.5 mm, SRL-H 38 64-28√ √ √

Superpave Wearing Course, 12.5 mm, SRL-M 38 64-28√ √ √

Superpave Wearing Course, 12.5 mm, RPS, SRL-H 38 64-28√ √ √

Superpave Wearing Course, 12.5 mm, SRL-H, Special 38 70-22√ √ √

Superpave Binder Course, 25 mm 50 58-28√ √ √

Superpave Binder Course, 25 mm, RPS 50 64-28√ √ √

Superpave Binder Course, 25 mm, Special 50 58-22

Superpave Base Course, 37.5 mm 100 58-28√ √ √

Superpave Base Course, 37.5 mm 175 58-28√ √ √

Superpave Base Course, 37.5 mm 225 58-22

Superpave Wearing Course, 12.5 mm, SRL-H 180 64-22

S.R.-Sec. Co.County

Mixture Tests

Binder Tests

Dis

tric

t

Dep

th (

mm

)

PG B

inde

r G

rade

A-6



. Ana

lysi

sFr

eq. S

wee

pR

ep. S

hear

IDT

DSR

- T

ank

DSR

- R

TFO

TB

BR

- PA

VD

T -

PAV

10-0(18)

0422 - 404 Indiana

Superpave Wearing Course, 19 mm, RPS, SRL-H 40 58-28√ √ √ √ √ √ √ √

Superpave Wearing Course, 19 mm, RPS, SRL-H (West Bound) 40 64-22√ √ √ √ √ √ √ √

Superpave, 37.5 mm 58-28√ √ √ √ √ √

10-0(19)

0022-PL1 Indiana

Superpave Wearing Course, 12.5 mm 64-22

NOTE Superpave Binder Course, 25 mm 64-22

Superpave Base Course, 37.5 mm 64-22

Superpave Wearing Course, 12.5 mm. RPS, SRL-H 38 64-22

Superpave Wearing Course, 12.5 mm. RPS, SRL-H 38 70-28 (Tyrsolv)

Superpave Wearing Course, 12.5 mm. RPS, SRL-H 50 70-28 (Tyrsolv)

Superpave Binder Course, 12.5 mm. RPS, SRL-H 50 64-22

SMA Wearing Course, SRL-H 50

Superpave Wearing Course, 12.5 mm. SRL-L

12-0(20)

0119 - 13R Fayette

Superpave Wearing Course, 19 mm, RPS, SRL-E 50 70-28√ √ √ √ √ √ √ √

Superpave Binder Course, 25 mm, RPS 50 64-22√ √ √

Superpave Binder Course, 25 mm, Leveling >50 64-22

Superpave Wearing Course, 9.5 mm, SRL-E, Leveling 64-22

Superpave Wearing Course, 9.5 mm 64-22

Superpave Binder Course 25.0 mm 64-22

Superpave Base Course, 37.5 mm 163 64-22√

Dis

tric

t

S.R.-Sec. Co.County D

epth

(m

m)

PG B

inde

r G

rade

Mixture Tests

Binder Tests

Information different

from different

tables

A-7

Table A.2 WO-43 Asphalt Binders Currently Available at NECEPT Laboratories.

Unaged RTFO PAVP001 PG 64-22 Lycoming No Yes Yes NoP002 PG 64-22 Lycoming No Yes Yes YesP003 PG 64-22 Lycoming No Yes Yes YesP004 PG 64-22 Lycoming No Yes Yes YesP005 PG 64-22 Lycoming No Yes Yes YesP006 PG 64-22 Lycoming No Yes Yes YesP007 PG 64-22 Lycoming No Yes Yes NoP008 PG 58-28 Crawford Yes Yes Yes NoP009 PG 58-28 Crawford No No Yes YesP010 PG 64-22 Snyder No Yes Yes NoP011 PG 58-28 Indiana Yes Yes Yes NoP012 PG 64-22 Indiana Yes Yes Yes YesP013 PG 58-28 Lycoming Yes Yes Yes YesP014 PG 70-28 Fayette Yes Yes Yes NoP015 PG 64-22 Fulton Yes Yes Yes YesP016 PG 64-22 Fulton Yes Yes Yes YesP017 PG 64-22 Clearfield Yes Yes Yes YesP018 PG 64-22 Clearfield Yes Yes Yes YesP019 PG 64-28 Clearfield Yes Yes No YesP021 PG 58-28 Lycoming Yes Yes Yes YesP024 PG 76-22 York Yes Yes No NoP025 PG 64-22 York Yes Yes Yes YesP026 PG 58-28 Huntingdon Yes Yes No NoP027 PG 58-22 Huntingdon Yes Yes No NoP028 PG 64-28 Huntingdon Yes Yes No NoP029 PG 70-22 Huntingdon Yes Yes No No

B9254 PG 64-28 Centre Yes Yes Yes NoB0108 PG 76-22 Franklin Yes Yes Yes NoB0115 PG 76-22 Franklin Yes Yes Yes NoB0117 PG 64-22 Franklin Yes Yes Yes NoB0123 PG 76-22 Franklin Yes Yes Yes NoB0124 PG 64-22 Franklin Yes Yes Yes No

Notes:

2. Processed material is in 1 ounce tins with enough material to perform a master curve and performance grading.1. Raw material is in quart cans and is either available (YES), or not available (NO).

Processed Material Available2Binder Sample County

Raw Material

Available1Binder Grade

A-8

Table A.3 WO-43 Asphalt Mixtures Currently Available at NECEPT Laboratories.

PG70-22

SR11 (38M)

19mm PMB SRL-L Intermediate

Snyder County

7.6 kg

16 kg

SR11 (38M) 19mm Poly Mod SRL-L

63 kgSR0119-13R 25mm Superpave Binder

PG64-22

40.8 kg

Fayette County

PG76-22

SR11 (38M)

25mm Binder

PG64-22

76.4 kg

28.7 kg9.5mm Superpave WearingPG64-22

PG70-28

SR0119-13R

19mm Superpave Wearing

SR0119-13R

SR0119-13R

76.6 kg37.5mm Superpave BCBC

PG?

York CountySR0030-B01

22 kg37.5mm PG64-22

SR0030-B01

67.2 kg19mm Wearing

PG76-22

SR0030-B01

29.6 kg25mm

PG64-22

SR0083-832

21.6 kg37.5mm Superpave BCBC

PG64-22

Huntingdon CountySR6522-001

31 kg25mmPG64-22

SR6522-001

33.7 kg25mmPG58-28

SR6522-001

32.7 kg37.5mmPG58-28

Fulton CountySR0070-009

39.3 kg25mmPG64-22

Lycoming CountySR15-B42

147.6 kg37.5mm BCBC

PG58-28

Berks CountySR61-10M

7.6 kg12.5mm Superpave

PG64-22

SR61-10M

13.2 kg19mm Superpave

PG64-22

Warren CountySR0062-12m/610

22 kg12.5mm Superpave WearingPG?

SR0062-12m/610

13.3 kg25mm Binder/LevelingPG?

SR0062-12m/610

4 kg25mm leveling

PG?

SR0062-12m/608

22.4 kg25mm Leveling

PG?

A-9

Table A.4 WO-43 Cores Currently Available at NECEPT Laboratories. County Route Section Layer # of Cores

Wearing 9Binder 12BCBC 10







York SR83 832

York SR30 B01

Lycoming SR153 B43

Warren SR62

Fulton SR70 B43

Lycoming SR153 B42

Fayette SR19 13R

APPENDIX

B

Pictures of Cores Obtained Under WO-9

B-2

Clearfield SR153- #4 (PG 64-22) Clearfield SR153- #2 (PG 64-28)

Centre I-80 #2 Centre I-80 - #6

Centre I-80 #9 Centre I-80 - #12

B-3

Huntingdon SR522- #4 Huntingdon SR522- #6 Table B-1 Location of Cores for Which Pictures Are Shown in This Appendix Highway County Core # Location Description SR 153 Clearfield 4 1030 ft north of

segment marker 650.

PG 64-22 Section Extension of longitudinal crack along WP

SR 153 Clearfield 2 1050 ft north of segment marker 690.

PG 64-28 Section Good pavement, WP

I-80 Centre 2 1350 ft east of MP 167

W: 12.5mm Mix, 40mm thick B: 19mm Mix, 50 mm thick


W: 19mm Mix, 50mm thick B: 25mm Mix, 75 mm thick

I-80 Centre 9 766 ft east of MP 168.5




SR 522 Huntingdon 4 Area with minor raveling SR 522 Huntingdon 6 501 feet from

intersection of SR 22 and SR 522

Right on crack

APPENDIX

C

Scope of Pavement Condition Survey

C-2

Pavement Condition Evaluation

Highway: SR 0015– Section B42/B43, Northbound Lane Width: 11 feet County: Lycoming Construction Year: 1997 District: 3 Survey Dates: 6/5/2007

Pavement Section Profile, Full Depth Construction – Northbound


Zero Mark

Northbound

22 fe

et

Wearing Course

Binder Course

ID-2, 1.5-inch layer, PG 64-22, NMAS: 9.5 mm

3-inch layer, PG 64-22, NMAS: 25 mm

Superpave, 1.5-inch layer, PG 64-28, NMAS: 12.5 mm

ID-2 Section: Zero mark (starting point of survey) is located 200 ft south of segment marker 1760. Pavement evaluation was conducted on travel lane for a stretch of 1400 feet northbound.

Superpave Section: Zero mark (starting point of survey) is located at segment marker 1770. Pavement evaluation was conducted on travel lane for a stretch of 1500 ft northbound.

Passing Lane

Travel Lane

PG 64-22, NMAS: 19 mm Leveling

Superpave PG 58-28, NMAS: 37.5 mm Base Course

C-3

Pavement Condition Evaluation Highway: SR 0015– Section B42/43, Southbound Lane Width: 11 feet County: Lycoming Construction Year: 1997 District: 3 Survey Dates: 6/6/2007

Pavement Section Profile, Overlay Construction – Southbound


Zero Mark

South Bound

22 fe

et

Wearing Course

Binder Course

2-inch layer, PG 64-22, NMAS: 25 mm


Zero mark (starting point of survey) is located 750 ft north of segment marker 1701. Pavement evaluation was conducted on travel lane for a stretch of 750 ft southbound. This 750-ft section consisted of Superpave mixes overlaying old concrete pavement. Beyond this section, moving south, a full depth Superpave construction exists, which is not part of this project.

Passing Lane

Travel Lane

Old Jointed Concrete Pavement

C-4


Highway: SR 11 Lane Width: 12 feet County: Snyder Construction Year: 1998 District: 3 Survey Dates: 6/14/2007

Pavement Section Profile


SR11: Southbound

Wearing Course

Binder Course

Concrete in three inner lanes and subbase at two outer lanes (widened section)

Superpave, 1.5-inch layer, PG 76-22, NMAS: 12.5 mm, travel lane

Superpave, 2-inch layer, PG 64-22, NMAS: 19 mm

Superpave, 2-inch layer, PG 64-22, NMAS: 12.5 mm, passing lane

11th

Ave

nue

Passing Lane

Travel Lane

Shoulder100 ft.

Zero Mark

Pavement evaluation started 100 ft before 11th Avenue and extended for 1500 ft southbound.

C-5

Pavement Condition Evaluation Highway: SR 153 – Section 225 Lane Width: 12 feet County: Clearfield Construction Year: 1997 District: 2 Survey Dates: 7/11/07 & 7/18/07

Pavement Section Profile


Southbound

Zero Mark

Northbound 22 fe

et

Wearing Layer

Binder Layer

ID-2 Leveling Course

1.5- inch layer, PG 64-22, NMAS: 12.5 mm, Sta. 798+33 to 917+00

2- inch layer, PG 64-22, 25 mm NMAS

1.5-inch, PG 76-28, NMAS: 12.5 mm, Sta. 917+00 to 1065+33

Old pavement: 8-inch aggregate base with several buildups of wearing course overlays Widened sections: subbase 2A and bituminous base course

PG 64-22 Section: Zero mark (starting point of survey) is located 850 ft north of segment marker 650. Pavement evaluation was conducted for a stretch of 1100 ft northbound.

PG 64-28 Section: Zero mark (starting point of survey) is located 850 ft north of segment marker 690. Pavement evaluation was conducted for a stretch of 900 ft northbound.

C-6


Highway: I-80 , MP 167-167.5 Lane Width: 12 feet County: Centre Construction Year: 1999 District: 2 Survey Dates: 7/31/2007

Pavement Section Profile – Overlay Construction – Control Section


I-80: Eastbound

Wearing Course

Binder Course


Superpave 2-inch layer, PG 64-22, NMAS: 19

Passing Lane

Travel Lane

Shoulder

Zero Mark

Zero Mark (starting point of survey) is located 950 ft east of MP 167. Pavement evaluation was conducted on travel lane for a stretch of 1000 ft eastbound.

Leveling Course Superpave, PG 64-22, 9.5 mm

Old Concrete Pavement - Patched

C-7


Highway: I-80 , MP 167.5-168 Lane Width: 12 feet County: Centre Construction Year: 1999 District: 2 Survey Dates: 7/31/2007

Pavement Section Profile – Overlay Construction – High ESAL Design


I-80: Eastbound

Wearing Course

Binder Course


Superpave 2-inch layer, PG 64-22, NMAS: 19 mm

Passing Lane

Travel Lane

Shoulder

Zero Mark

Zero Mark (starting point of survey) is located 450 ft east of MP 167.5. Pavement evaluation was conducted on travel lane for a stretch of 1000 ft eastbound.



C-8



Pavement Section Profile – Overlay Construction – 25-mm Binder Course-Thick Layers


I-80: Eastbound

Wearing Course

Binder Course

Superpave, 2- inch layer, PG 64-22, NMAS: 12.5 mm

Superpave 3- inch layer, PG 64-22, NMAS: 25 mm

Passing Lane

Travel Lane

Shoulder

Zero Mark




C-9


Highway: I-80 , MP 168.5-169 Lane Width: 12 feet County: Centre Construction Year: 1999 District: 2 Survey Dates: 7/31/2007

Pavement Section Profile – Overlay Construction – 19-mm Binder Course – Thick Layers


I-80: Eastbound

Wearing Course

Binder Course

Superpave, 2 inches, PG 64-22, 12.5 mm NMAS

Superpave 3 inches, PG 64-22, 19 mm NMAS

Passing Lane

Travel Lane

Shoulder

Zero Mark

Zero Mark (starting point of survey) is located 400 ft east of MP 168.5. Pavement evaluation was conducted on travel lane for a stretch of 1000 ft eastbound.



C-10



Pavement Section Profile – Overlay Construction-19-mm Binder Course – Thick Binder Layer


Wearing Course

Binder Course

Superpave, 1.5- inch, PG 64-22, NMAS: 12.5 mm

Superpave 3- inch, PG 64-22, NMAS: 19 mm

I-80: Eastbound Passing Lane

Travel Lane

Shoulder

Zero Mark




C-11


Highway: SR 522–001 Lane Width: 11 feet County: Huntingdon Construction Year: 1998 District: 9 Survey Dates: 11/8/2007

Pavement Section Profile, Overlay Construction – Southbound


Zero Mark

Southbound 22 fe

et

Wearing Course

Binder Course

Superpave, 2- inch layer, PG 58-28, NMAS: 25 mm

Superapave, 1.5-inch layer, PG 64-28, NMAS: 12.5 mm

Zero mark (starting point of survey) is located 92 ft south of SR22/SR522 intersection. Pavement evaluation was conducted for a stretch of 800 ft southbound.

Base Course Superpave, 7- inch layer, PG 58-28, 37.5 mm

Northbound

APPENDIX

D

Aggregate Gradations Obtained from WO-9 Cores

D-2

Clearfield SR 153 Wearing Course - PG 64-22 Section

Gradation for Core # 2

SievesUS SI,mm

Units Units Core # 21.5 37.5 100.01 25 100.0

3/4 19 100.01/2 12.5 96.33/8 9.5 91.3#4 4.75 62.7#8 2.36 43.8

#16 1.18 27.7#30 0.6 18.3#50 0.3 13.2

#100 0.15 10.8#200 0.075 9.0pan 0 0.0

0.010.020.030.040.050.060.070.080.090.0

100.0

Sieve Size (mm) Raised to 0.45 Power

Perc

ent P

assi

ng

D-3



SievesUS SI,mm

Units Units Core # 51.5 37.5 100.01 25 100.0

3/4 19 100.01/2 12.5 94.23/8 9.5 86.6#4 4.75 58.9#8 2.36 40.5

#16 1.18 25.9#30 0.6 18.1#50 0.3 13.8

#100 0.15 11.5#200 0.075 9.7pan 0 0.0

0.0

10.0

20.0

30.0

40.0

50.0

60.0

70.0

80.0

90.0

100.0


Perc

ent P

assi

ng

D-4



SievesUS SI,mm

Units Units Core # 61.5 37.5 100.01 25 100.0

3/4 19 100.01/2 12.5 93.83/8 9.5 86.0#4 4.75 59.1#8 2.36 41.1

#16 1.18 26.9#30 0.6 19.4#50 0.3 15.2

#100 0.15 13.0#200 0.075 11.0pan 0 0.0

0.010.020.030.040.050.0

60.070.080.090.0

100.0


Perc

ent P

assi

ng

D-5



SievesUS SI,mm

Units Units Core # 11.5 37.5 100.01 25 100.0

3/4 19 100.01/2 12.5 95.03/8 9.5 88.2#4 4.75 61.4#8 2.36 43.8

#16 1.18 28.1#30 0.6 18.9#50 0.3 13.8

#100 0.15 11.2#200 0.075 9.1pan 0 0.0

0.010.0

20.030.0

40.050.0

60.070.0

80.090.0

100.0


Perc

ent P

assi

ng

D-6

Huntingdon SR 522 Wearing Course - PG 64-28


SievesUS SI,mm

Units Units Core # 11.5 37.5 100.01 25 100.0

3/4 19 100.01/2 12.5 93.53/8 9.5 87.2#4 4.75 59.7#8 2.36 38.0

#16 1.18 23.8#30 0.6 15.6#50 0.3 11.0

#100 0.15 8.8#200 0.075 7.3pan 0 0.0

0.010.0

20.030.0

40.050.0

60.070.0

80.090.0

100.0


Perc

ent P

assi

ng

D-7



SievesUS SI,mm

Units Units Core # 21.5 37.5 100.01 25 100.0

3/4 19 99.11/2 12.5 92.43/8 9.5 87.4#4 4.75 57.5#8 2.36 36.9

#16 1.18 23.4#30 0.6 15.4#50 0.3 10.9

#100 0.15 8.7#200 0.075 7.2pan 0 0.0

0.010.0

20.030.0

40.050.0

60.070.0

80.090.0

100.0


Perc

ent P

assi

ng

D-8



SievesUS SI,mm

Units Units Core # 51.5 37.5 100.01 25 100.0

3/4 19 100.01/2 12.5 94.93/8 9.5 88.4#4 4.75 59.3#8 2.36 37.0

#16 1.18 22.8#30 0.6 15.0#50 0.3 10.6

#100 0.15 8.5#200 0.075 7.0pan 0 0.0

0.010.0

20.030.0

40.050.0

60.070.0

80.090.0

100.0


Perc

ent P

assi

ng

D-9

Centre I-80 Wearing Course – 19 mm Mix


SievesUS SI,mm

Units Units Core # 61.5 37.5 100.01 25 100.0

3/4 19 100.01/2 12.5 90.73/8 9.5 81.6#4 4.75 45.8#8 2.36 30.3

#16 1.18 19.8#30 0.6 14.3#50 0.3 10.7

#100 0.15 8.6#200 0.075 6.7pan 0 0.0

0.010.0

20.030.0

40.050.0

60.070.0

80.090.0

100.0


Perc

ent P

assi

ng

D-10

Centre I-80 Wearing Course – 19 mm Mix


SievesUS SI,mm

Units Units Core # 71.5 37.5 100.01 25 100.0

3/4 19 100.01/2 12.5 89.83/8 9.5 80.6#4 4.75 46.1#8 2.36 30.3

#16 1.18 19.7#30 0.6 14.2#50 0.3 10.5

#100 0.15 8.4#200 0.075 6.5pan 0 0.0

0.010.0

20.030.0

40.050.0

60.070.0

80.090.0

100.0


Perc

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D-11

Centre I-80 Wearing Course – 12.5 mm Mix


SievesUS SI,mm

Units Units Core # 101.5 37.5 100.01 25 100.0

3/4 19 100.01/2 12.5 96.23/8 9.5 91.5#4 4.75 49.8#8 2.36 32.2

#16 1.18 21.7#30 0.6 15.7#50 0.3 11.6

#100 0.15 9.0#200 0.075 6.8pan 0 0.0

0.010.0

20.030.0

40.050.0

60.070.0

80.090.0

100.0


Perc

ent P

assi

ng

Date post:	02-Jan-2017
Category:	Documents
Upload:	trinhhanh
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Field-Focused Superpave Validation

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