DOE/AL/99567--1 (DE97000259 )

DIStribution Category UC-t414

DEVELOPMENT OF ASPHALTS AND PA VEMENTS USING RECYCLED TIRE RUBBER

Phase I: Technical Feasibility

Technical Progress Report

By Jerry A. Bullin

Richard R. Davison Charles J. Glover

Cindy Estakhri Raymond W. F1umerfelt

Travis Billiter Jay Chum

HeamoKoo Vikas Sheth

Gerald Elphingstone Clint Eckhardt

June 1996

Work Performed Under Contract No. DE-FC04-94AL99567

Prepared for U.S. Department of Energy

Office ofIndustrial Technologies Washington, D.C.

Prepared by Texas Transportation Institute

College Station, Texas

DISCLAIMER

This report was prepared as an account of work IIpODSOred by an agency of the United Slates Government. Neither the United States Govcmmcnt nor any agency thereof, nor any of their employees, makes any warranty I express or implied, or assumes any legal liability or Jeoponsibility fur the ~, comp1ercness, or usefulness of any information, apparatus, product, or process disclosed, or represents that its use would not infringe privately owned rights. Reference ben:in to any opocific commercial product, proc:cas, or service: by trade name, trademark, lIWIufacturer, or otherwise cines not necessarily constitute or imply its cndonement, recoii1lilCDdalion, or favoring by the United States Clov<nun<m or any agency thereof. The views and opinions of aulhon """","ed herein do not necessarily stale or rellec:t those of the United _ Govemmcm or any agency thereof.

This report has been reproduced directly from the best available copy.

Available to DOE and DOE conttactors from the Office of Scientific and Technical Information, P.O. Box 62, Oak Ridge, TN 37831; prices available from (615)576-8401.

Available to the public from the U.S. Department of Commerce, Technology Administration, National Technical Information Service, Springfield, VA 22161, (703)487-4650.

DOE! ALl99567-1

DEVELOPMENT OF ASPHALTS AND PA VEMENTS USING RECYCLED TIRE RUBBER

Phase I: Technical Feasibility

Technical Progress Report

By Jerry A. Bullin Richard R. Davison Charles J. Glover Cindy Estakhri Raymond W. Flumerfelt Travis Billiter Jay Chum HeamoKoo Vikas Sheth Gerald Elphingstone Clint Eckhardt

June 1996

Work Performed Under Contract No. DE-FC04-94AL99567

For U.S. Department of Energy Office of Industrial Technologies Washington, D.C.

In Cooperation with Texas A&M University Research Foundation Texas Transportation Institute Department of Chemical Engineering

PREFACE

This report documents the technical progress made on the DOE funded project

"Development of Asphalts and Pavements Using Recycled Tire Rubber" for the time period

covering September I, 1994 through August 31, 1995. Cost sharing for this study is being

supplied by the Texas Department of Transportation and industry. Bruce Cranford is the Program

Man<\ger for the DOE Office of Industrial Technologies. Ken Lucien is the Project Officer and

M. Laurene Dubuque is the Contracting Officer, both for the DOE Albuquerque Operations

Office. Frank Childs, the Project Technical Monitor, is on the staff of Scientech, Inc., Idaho

Falls, Idaho. Professors Jerry A. Bullin, Charles J. Glover, Richard R. Davison, and Raymond

W. Flumerfelt, together with Cindy K. Estakhri of the Texas Transportation Institute are the Co­

Principal Investigators. Other co-authors of this report are current PhD candidates Travis Billiter,

Vikas Sheth, and Gerald Elphingstone and masters students Jay Chun and Hearno Koo, and

technician Clint Eckhardt.

Work supported by the U.S. Department of Energy, Assistant Secretary for Energy Efficiency and

Renewable Energy, Office of Industrial Technologies, under DOE Albuquerque Operations Office

Cooperative Agreement DE-FC04-94AL99567.

i

TABLE OF CONTENTS

Page

Preface ...... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Table of Contents ................................................ ii

List of Figures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . v

List of Tables ................................................. IX

Chapter

1 Introduction and Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

2 Laboratory Testing and Evaluation .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

Fractionate Asphalt Material ., . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

Reblend for Aromatic Asphalts ................................. 6

Verify Optimal Parameters ... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

Curing Temperature as a Variable ............................. 9

Curing Time as a Variable . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

Rubber Amount as a Variable . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 12

Rubber Particle Size as a Variable . . . . . . . . . . . . . . . . . . . . . . . . . . .. 12

Rubber Type as a Variable . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 16

Mixing Speed as a Variable ................................ 16

Asphalt Type as Variable . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20

General Conclusions about Curing Asphalt with Rubber .............. 20

Age Blends . . . . . • . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

Hardening Susceptibility .................................. 22

Aging Rate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27

Hardening Rate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27

Development of Microductility Test ............................. 37 for use with Asphalt-Rubber Binders

Experimental Method (Hveem et al.) .......................... 38

Modified Experimental Method . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38

Application . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. " 39

ii

3 Evaluate Mixture Characteristics ................................. 40

Evaluate Compaction Characteristics of Mixtures ..................... 40

Evaluate Deformation and Failure of Compacted Mixtures ............... 49

4 Adhesion Test Properties ...................................... 51

Adhesion Tests. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53

Wilhelmy Plate Method . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53

Gas Adsorption . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56

Adhesion and Cohesion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59

Water Susceptibility Tests. . . . . . . . . . . . . . . . . ... . . . . . . . . . . . . . . . . . 59

Summary of Adhesion Tests . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59

5 Economic Summary ......................................... 68

The Rose Refining Process .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69

Crumb Rubber Modified Asphalt Pavement ........................ 70

Capital Cost ... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70

Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70

Energy Use .......................................... 71

Waste . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72

References ................................................... 73

Abbreviations ................................................. 77

Notation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . : . . . . . . . . 78

Appendix A: Experimental Methods .................................. 79

Supercritical Fractionation ................................... 79

Pressure Oxygen Vessel (POV) ................................ 82

Corbett Analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 84

Mixing Apparatus . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 84

Bending Beam Rheometer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 85

Dynamic Shear Rheometer .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 85

Brookfield Rotational Viscometer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 86

iii

Gel Permeation Chromatography (GPC) . . . . . . . . . . . . . . . . . . . . . . . . . . . 87

Fourier Transform Infrared Spectroscopy (FTIR) . . . . . . . . . . . . . . . . . . . . . 87

Microductility Measurements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 88

Appendix B: arT Spreadsheets .................................... 89

iv

LIST OF FIGURES

Page

Figure 2-1. Effect of Curing Temperature on Viscosity @ 60°C ............... 10 10% TG-40 and 90% Fina AC-IO

Figure 2-2. Effect of Curing Temperature on Low Temperature Data . . . . . . . . . . .. 10 10% TG-40 and 90% Fina AC-IO

Figure 2-3. Effect of Curing Temperature on the Solubility of ................ 11 Rubber 10% TG-40 and 90% Fina AC-1O

Figure 2-4. Intermediate and High Temperature Data ., . . . . . . . . . . . . . . . . . . .. 11 10% TG-1O and 90% Exxon AC-S

Figure 2-S. Low Temperature Data 10% TG-lO and 90% Exxon AC-S ........... 13

Figure 2-6. Solubility of Rubber in Asphalt 10% TG-IO and 90% Exxon AC-S ...... 13

Figure 2-7. Effect of Rubber Amount on Temperature Susceptibility ............ 14 Sand 10% TG-40 with Fina AC-IO

Figure 2-8. Low Temperature Data Fina AC-lO and TG Blends ............... 14

Figure 2-9. Effect of Particle Size on Temperature Susceptibility . . . . . . . . . . . . . .. IS Exxon AC-S and 10% Rouse Blends

Figure 2-10. Low Temperature Data Exxon AC-S and RS Blends ............... IS

Figure 2-11. Effect of Particle Size on Solubility of Rubber . . . . . . . . . . . . . . . . . .. 17 in Asphalt Exxon AC-S and RS Blends

Figure 2-12. Effect of Rubber Type on Temperature'Susceptibility .............. 17 Fina AC-I0 with 10% TG-lO and RS-lO

Figure 2-13. Low Temperature Data 90% Fina AC-I0 ...................... 18 with 10% TG-1O and 10% RS-lO

Figure 2-14. Effect of Rubber Type on the Solubility of Rubber ................ 18 90% Fina AC-lO with 10% TG-1O and 10% RS-lO

Figure 2-1S. Effect of Mixing Speed on Temperature Susceptibility .............. 19 Fina AC-lOwith 10% TG-lO

Figure 2-16. Effect of Mixing Speed on Low Temperature Data ................ 19 10% TG-lO and 90% Fina AC-1O

Figure 2-17. Effect of Mixing Speed on Solubility of Rubber in ................ 21 Asphalt 10% TG-lO and 90% Fina AC-I0

v

Figure 2-18.

Figure 2-19.

Figure 2-20.

Figure 2-2l.

Figure 2-22.

Figure 2-23.

Figure 2-24.

Figure 2-25.

Figure 2-26.

Figure 2-27.

Figure 2-28.

Figure 2-29.

Figure 2-30.

Figure 2-3l.

Figure 2-32.

Figure 2-33.

Figure 2~34.

Figure 2-35.

Figure 2-36.

~ Figure 2-37.

Figure 2-38.

Figure 2-39.

Figure 2-40.

Figure 3-1.

Figure 3-2.

Figure 3-3.

Hardening .susceptibilities of Exxon AC-5 Blends ................. 23

Hardening Susceptibilities of Exxon AC-IO and Blends ............. 23

Hardening Susceptibilities of Fina AC-IO and Blends .............. 24

Hardening Susceptibility of Exxon AC-5 ...................... 25

Hardening Susceptibility of 5/95 Exxon AC-5 and TG -40B .......... 25

Hardening Susceptibility of 10/90 Exxon AC-IO and TG -40B ......... 26

Comparing the Hardening Susceptibilities . . . . . . . . . . . . . . . . . . . . . . 26 of POV-aging and ENV-aging

Hardening Susceptibilities of Exxon AC-5 and Blends . . . . . . . . . . . . . . 28

Aging Rates of Exxon AC-5 and Blends at 190"F . . . . . . . . . . . . . . . . . 28

Aging Rates of Exxon AC-I0 and Blends at 200"F ................ 29

Aging Rates of Fina AC-I0 and Blends at 21O"F ................. 29

Aging Rates of Exxon AC-5 and Blends at 14O"F . . . . . . . . . . . . . . . . . 30

Aging Rate Kinetics Plot of Exxon AC-5 and Blends . . . . . . . . . . . . . . . 30

Hardening Rates of Fina AC-lO and Blends at 19O"F ............... 31

Hardening Rates of Exxon AC-5 and Blends at 200"F .............. 31

Hardening Rates of Exxon AC-I0 and Blends at 21O"F ............. 32

Hardening Rate Kinetics Plot of Exxon AC-5 and Blends . . . . . . . . . . . . 32

Hardening Susceptibilities of Fina AC-IO and Blends at 14O"F ......... 34

Hardening Susceptibilities of Exxon AC-5 and Blends at 140"F ........ 34

Hardening Susceptibilities of Exxon AC-lO and Blends at 140"F ....... 35

Change in Delta with Aging for Fina AC-IO and Blends. . . . . . . . . . . . . 35

Change in Delta with Aging for Exxon AC-5 and Blends ............ 36

Change in Delta with Aging for Exxon AC-I0 and Blends ........... 36

Density Versus GTM Revolution for CRM Asphaltic Mixtures ........ 42 Prepared with Binders Containing -#10 Mesh CRM

Density Versus GTM Revolution for CRM Asphaltic Mixtures ........ 42 Prepared with Binders Containing -#40 Mesh CRM

Density Versus GTM Revolution for CRM Asphaltic Mixtures ........ 43 Prepared with Binders Containing -#80 Mesh CRM

vi

Figure 3-4. Effect of CRM Particle Size on ............................ 44 Gyratory Compactibility Index (GCI)

Figure 3-5. Effect of CRM Concentration on ........................... 44 Gyratory Compactibility Index (GCI)

Figure 3-6. Effect of Binder Curing Time on Gyratory ..................... 45 Compactibility Index (GCI)

Figure 3-7. Effect of CRM Particle Size on Gyratory Stability Index (GSI) ........ 46

Figure 3-8. Effect of CRM Concentration on Gyratory Stability Index (GSI) ....... 46

Figure 3-9. Effect of Binder Curing Time on ........................... 47 Gyratory Stability Index (GSI)

Figure 3-10. Sample Height Before Extrusion from the ...................... 48 Mold and 24-Hours After Extrusion

Figure 4-1. Work of Cohesion ..................................... 52

Figure 4-2. Work of Adhesioin ....... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52

Figure 4-3. Dynamic Wilhelmy Plate Method Force Balance ................. 54

Figure 4-4. Wilhelmy Plate Apparatus. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55

Figure 4-5. Example Experimental Results ............................. 57

Figure 4-6. Surface Energy of Various Asphalts ......................... 57

Figure 4-7. Gas Adsorption Experimental Apparatus. . . . . . . . . . . . . . . . . . . . . . . 58

Figure 4-8. Surface Energy of Various Aggregates . . . . . . . . . . . . . . . . . . . . . . . . 61

Figure 4-9. Work of Cohesion of Various Asphalts ....................... 61

Figure 4-10. Work of Adhesion and Cohesion of Various Asphalts .............. 62 with Aggregate JOlla in Vacuum

Figure 4-11. Work of Adhesion and Cohesion of Various Asphalts .............. 62 with Aggregate JG21 in Vacuum

Figure 4-12. Work of Adhesion for Various Asphalts and Aggregates in Vacuum ..... 63

Figure 4-13. Work of Adhesion !ilf Various Asphalts with Aggregate JG 11a . . . . . . . . . 63

Figure 4-14. Work of Adhesion of Various Asphalts with Aggregate JG21 ......... 64

Figure 4-15. Work of Adhesion and Cohesion of Various Asphalts .............. 64 with Aggregate JG11a in Water

Figure 4-16. Work of Adhesion and Cohesion of Various Asphalts .............. 65 with Aggregate JG21 in Water

vii

Figure 4-17. Work of Adhesion for Various Asphalts and Aggregates in Water ...... 65

Figure A-I. Supercritical Unit Process Diagram .......................... 80

Figure A-2. Legend for Supercritical Extraction Unit Diagram ................ 81

Figure A-3. Pressure Oxygen Vessel Control Panel ........................ 83

Figure A-4. Pressure Oxygen Vessel and Control Panel ..................... 83

Vlll

Table I-I.

Table 2-1.

Table 4-1.

Table 4-2.

Table 4-3.

Table 5-1.

Table 5-2.

LIST OF TABLES

Page

Proposed Schedule for Completion of Tasks ..................... 2

Chemical Composition of Several Asphalts ...................... 6 and Supercritical Fractions

Characterized Asphalts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60

Characterized Aggregates . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60

Ranking of Asphalt Aggregate Systems ....................... 66

Estimated Cost to Produce Aromatic Material ................... 69 Using a Supercritical Fractionation Unit

CRMA Pavement versus Conventional . . . . . . . . . . . . . . . . . . . . . . . . 72 Asphalt Pavement Comparison

IX

CHAPTER 1

INTRODUCTION AND SUMMARY

Approximately 285 million tires are discarded every year. Of these, less than 100 million

are currently being recycled. The excess tires not being recycled are placed in landfills and other

waste sites, collecting moisture, breeding insects, and constituting a general nuisance.

A solution to reduce the littering of the environment is to use ground tire rubber in the

construction of the nation's roadways. Currently, about 27 million tons of asphalt are used each

year to construct and maintain most of the country's two million miles of roads (Takallou and

Takallou, 1991). If all of the waste tire rubber could be combined with asphalt in road

construction, it would displace less than 6% of the total asphalt used each year, yet could save

about 60 trillion BTUs annually. This suggests there is a great opportunity to solve a serious

waste problem, save energy, and improve asphalt roadway life and performance.

The use of tire rubber with various types of asphalt pavements has been demonstrated in

recent years with promising results (Sainton, 1990). Unfortunately, the technology for using

ground tire rubber is relatively undeveloped, and the results of using rubber-asphalt concrete have

been very erratic. The purpose of this project is to provide data needed to optimize the

performance of rubber-asphalt concretes and avoid failures of the past.

The first phase of the overall project is to implement the exploratory development (phase

I). This was to develop asphalts and recycling agents tailored for compatibility with ground tire

rubber in order to eliminate or reduce compatibility problems to improve compaction properties.

To accomplish this objective, this project has been divided into several tasks. The proposed

schedule for completion of all tasks is given in Table I-I.

Chapter 2 presents results obtained during the first year of this project on Laboratory

Testing and Evaluation (Task 1). This task was divided into four parts, the first of which was

Fractionate Asphalt Material (Task 1.1). For this portion, various asphalts and Residuum Oil

Supercritical Extractions (ROSE) fractions were fractionated in a supercritical unit to obtain highly

aromatic material of various viscosities. Shell AC-20 was fractionated to produce a highly-

1

Table I-I. Proposed Schedule for Completion of Tasks

TASK NAME COMPLETION DATE

1 Laboratory Testing and Evaluation

1.1 Fractionate Asphalt Material 2/96

1.2 Reblending for Aromatic Asphalts 5/96

1.3 Verifying Optimal Curing Parameters 8/95

1.4 Aged Blends 10/96

2 Evaluating Mixture Characteristics

2.1 Developing an Experiment Plan 11196

2.2 Evaluating Compaction Characteristics of Mixtures 5/96

2.3 Evaluating Deformation and Failure of Compacted Mixtures 8/96

3 Adhesion Test Development

3.1 Adhesion Tests 8/99

3.2 Water Susceptibility 8/99

4 Commercialization Plan 8/99

aromatic, low asphaltene AC-5 asphalt and to also produce various highly-aromatic recycling

agents. Also, various ROSE fractions were obtained from Murphy, Diamond Shamrock, Witco,

and Fina. These were prepared as potentia! asphalts and recycling agents.

The second portion of Chapter 2 concerns the Reblending for Aromatic Asphalts (Task

1.2). The supercritical fractions of the Shell AC-20 have been characterized and blended to

produce a large quantity of a highly-aromatic, low-asphaltene AC-5. A Sun 125 recycling agent

was blended with a Murphy resin to produce a highly-aromatic, low-asphaltene AC-5. Also,

Diamond ShaInrock and Fina resins were characterized for possible use as components of highly­

aromatic asphalts.

The next section involves Verifying Optimal Curing Parameters (Task 1.3). The ultimate

goal of this portion of the research was to determine the optimal curing variables that results in

2

an asphalt-rubber being flexible at low temperatures, resists rutting at road temperatures, and is

compactibl,' at high temperatures. This involves optimizing the following seven variables: asphalt

composition, rubber type, rubber content, rubber particle size, curing temperature, curing time,

and curing shear rate.

The fourth part of Chapter 2 concerns Aged Blends (Task 1.4). The asphalt-rubber blends

prepared in Task 1.3 were aged in a pressure oxygen vessel (POY) and in a 140"F environmental

(ENV) room to evaluate the aging rates of typical road conditions. The physical properties of the

aged samples were analyzed using a rheometer and Fourier Transform Infrared (FTIR)

Spectrometer. From such data, hardening susceptibilities, aging rates, and hardening rates were

determined for the aged samples.

The final portion of Chapter 2 describes a test that will be used to measure ductilities of

asphalt-rubber binders. The apparatus and procedure used for such experiments was developed

by California's Division of Highways. Because this method accommodates samples at relatively

low temperatures (35-45"F), it may provide additional support for the low-temperature benefits

of rubber-modified binders.

Chapter 3 focuses on Evaluating Mixture Characteristics (Task 2). The main goal of this

part of the project is to evaluate the modified binders in asphalt concrete mixtures. This chapter

was divided into three subtasks, the first being Developing an Experiment Plan (Task 2.1). This

plan has been developed and implemented within the first year of this study.

The second part of this chapter presents progress made on Evaluating Compaction

Characteristics of Mixtures (Task 2.2). The U.S. Army Corps of Engineers gyratory procedure

(ASTM 3387) is being used to evaluate the compaction characteristics of the materials. This is

essentially an instrumented version of the Texas gyratory compactor and can be used to describe

the progression of material changes throughout the compaction process. The procedure is

designed to address both the compatibility and performance-related issues of mix designs such as

rutting.

. The next portion of this chapter concerns Evaluating Deformation and Failure of

Compacted Mixtures (Task 2.3). The prepared materials are currently being aged. They are then

to be tested for deformation and failure using three test methods: (1) "non-destructive" sinusoidal

3

frequency sweeps (fully reversed tension-compression), (2) creep and recovery, and (3) tensile

strength to failure. The mixtures with the optimum combination of resistance to aging and

permanent deformation/cracking will be selected for further study.

Chapter 4 details work accomplished during the first year involving an Adhesion Test

Development (Task 3). The objective of this task is developing methods to measure the adhesive

and cohesive strength of asphalt-rubber/aggregate systems. This chapter is divided into two parts.

The first portion concentrates on describing Adhesion Tests (Task 3.1). The main goal of this

portion of the work is to develop improved test procedures to measure aggregate surface energies.

The next section of this chapter concerns Water Susceptibility Tests (Task 3.2). The

objective of this portion of the project is to develop improved tests for water susceptibility.

Although an improved test is currently in the process of development, a theoretical prediction of

water susceptibility is available from surface energy measurements. The aggregates appear to be

more important than the asphalts in determining which mix is water susceptible. This may be due

to the larger acid-base interaction parameter of the aggregates since it is theorized that water

attacks the acid-base portion of the asphalt-aggregate bonds. The mixes that have a large acid­

base interaction parameter are more likely to water strip.

The final chapter focuses on the Performance/Economic Update and Commercialization

Plan (Task 4) of this report. First-year work centered on finishing the DOE-Orr Projection

Description which included completing a performance/economic analysis of the complete system.

4

CHAPTER 2

LABORATORY TESTING AND EVALUATION

The overall objective for this portion of the project was to formulate improved asphalts for

use with ground tire rubber as well as improved recycling agents for recycling asphalt rubber (AR)

concretes. In addition, parameters such as rubber type, rubber content, rubber particle size,

mixing temperature, mixing time, and mixing shear rate were studied with these asphalts.

FRACTIONATE ASPHALT MATERIAL

The Supercritical (SC) fractionation apparatus design and operation is described by

Davison et al. (1991, 1992) in detail under TxDOT studies 1155 and 1249. Modifications were

made in the TxDOT Study 1314 (Davison et al., 1994). The unit operates at constant pressure

above the critical pressure of the solvent. It separates heavy petroleum products into a maximum

of four fractions according to solubility in SC solvents. The temperatures of the separators

determine the density of the solvent, therefore, controlling the solvent power in each vessel.

Components of the feed precipitate when no longer soluble in the solvent. The lightest, most­

soluble materials are removed by decompression during solvent recovery.

Numerous runs were made in supercritically fractionating Shell AC-20. Enough Shell AC-

20 was fractionated to produce a highly-aromatic, low-asphaltene AC-5 asphalt and to also

produce various highly-aromatic recycling agents. Furthermore, various ROSE fractions were

obtained from Murphy, Diamond Shamrock, Witco, and Fina. The fractions represent both

potential asphalts and recycling agents. The fractions were evaluated and characterized for use

as supercritical asphalts.

As a means of comparison, Corbett fractions were obtained for various asphalts.

Although, these fractions were not produced by supercritical methods, the fractions obtained via

Corbett fractionation were used as tools in understanding asphalt chemistry in general. Quantities

of Corbett fractions (saturates, naphthene aromatics, polar aromatics, and asphaltenes) were

5

produced. The composition of 6 asphalts/supercritical fractions are given in Table 2-1. Three

are asphalts- Exxon AC-5, Exxon AC-lO, and Fina AC-IO while the other three are supercritical

fractions- Fina Demex Resin, Supercritical Asphalt, and Diamond Shamrock (DS) Resin.

Two of the supercritical fractions had the highest aromatic content: Fina Demex Resin and

Supercritical Asphalt. The remaining supercritical fraction, the DS Demex Resin, has low

asphaltenes but a very high saturate content. The three asphalts all had a lower aromatic content

than the supercritical fractions, with the composition of the three being very similar.

Table 2-1. Chemical Composition of Several Asphalts and Supercritical Fractions

Chemical Composition

ASPHALT % Polar % Napthene % Asphaltenes Aromatics Aromatics % Saturates

Exxon AC-5 10.80 31.11 45.52 12.57

Exxon AC-I0 12.68 26.60 48.40 12.31

FinaDemex 3.00 38.18 49.65 9.19 Resin

Fina AC-lO 14.46 30.12 43.35 12.08

Supercritical 2.97 35.74 . 52.58 8.70 Asphalt

DS Demex 4.13 34.14 46.26 15.47 Resin

REBLEND FOR AROMATIC ASPHALTS

Several supercritical fractions produced earlier were used to obtain sufficient quantities

of highly-aromatic ,low-asphaltene asphalts. The supercritical fractions of the Shell AC-20 have

been characterized and blended to produce a large quantity of a highly-aromatic low-asphaltene

AC-5 supercritical asphalt. Furthermore, a Sun 125 recycling agent and a Murphy resin were

blended to produce a highly-aromatic low-asphaltene AC-5. The supercritical asphalt and the

6

Murphy/Sun asphalt both have an acceptable temperature susceptibility, which is the slope

resulting from a plot of log viscosity (11*) versus l/(Temperature).

Diamond Shamrock and Fina resins were characterized for possible use as components of

highly-aromatic asphalts. The Fina resin has an acceptable temperature susceptibility and its

viscosity of 285 poise at 60DC makes it well suited for use as an asphalt for blending with rubber.

The Diamond Shamrock (DS) resin contained solvent which had to be removed before analysis.

The DS resin, with a viscosity of 626.8 poise at 6O"C and an acceptable temperature susceptibility,

can be mixed with rubber to produce an acceptable binder. Chemical analysis for saturate,

aromatic, and asphaltene content utilizing the Corbett column was performed on the Fina and DS

resin with the results listed previously in Table 2-1.

VERIFY OPTIMAL PARAMETERS

The ultimate goal of the curing study was to determine the optimal curing variables that

allows production of asphalt-rubber that is flexible at low-temperature, resists rutting at road­

temperatures, and is compactible at high- temperatures. This task was achieved by investigating

one variable while holding the other variables constant. The verification of the optimal parameters

involved the following seven variables: asphalt composition, rubber type, rubber content, rubber

particle size, curing time, curing temperature, and curing shear rate. Work planned in the first­

year of the project involved using the following materials and conditions:

-Four asphalts: Fina AC-lO, Exxon AC-I0, Exxon AC-5, and a Murphy/Sun AC-1O.

-Two rubber types: Rouse (RS) and Tire Gator (TG).

-Four rubber contents: 5, 10, 15, and 20%.

-Three rubber mesh sizes: -10, -40, and -80 mesh.

~Variable curing times: Up to 60 hours.

-Three curing temperatures: 350, 375, and 4oo"F.

-Two curing shear rates: 500 and 1550 RPM.

The blending of the various asphalt-rubber binders occurred in the mixing apparatuses

where each binder was contained and heated to the desired temperature within a holding tank and

7

stirred with a mixer blade turned by a I/]6 hp motor. While curing, nitrogen was introduced into

the tank to create an oxygen-free blanket over the binder and thus prevent oxidation.

Furthermore, the effects of the above variables on the binder are being investigated with the

following analytical equipment (see Appendix A for equipment descriptions):

-Bending beam rheometer: Determines low-temperature (SOF) rheological properties.

-Cam-Med rheometer: Determines intermediate-temperature (32 -194 F) rheological

properties.

-Brookfield rheometer: Determines high-temperature (300-400"F) viscosities.

-Fourier transform infrared spectrometer (FTIR): Determines carbonyl areas.

-Gel permeation chromatography: Determines molecular-size distributions.

-High pressure liquid chromatography: Determines chemical compositions.

-Rubber recovery: Determines rubber amount in asphalt solution as a result of curing.

A brief summary of the findings are listed below with detailed discussion of each variable studied

following.

-Asphalt composition: The compatibility of the asphalt and the rubber is definitely

dependent upon the asphalt composition. Preliminary findings indicate that low-asphaltene

highly-aromatic asphalts are the most compatible. Furthermore, high-asphaltene high­

saturate asphalts are the least compatible

-Rubber type: For Rouse (RS) and Tire Gator (TG) rubber of the same particle size, the

Rouse rubber is better at improving the binder properties than the TG rubber. It

is believed that this can be explained by the fact that for equivalent "labeled" mesh

sizes, i.e. -10, -40, or -80 mesh, the distribution of the Rouse rubber is finer than

the TG rubber.

-Rubber content: Generally, the properties of a binder were found to improve with

increasing rubber content within the range tested, 0 to 20%. The viscosity at

rutting temperature (14O"F) increases, the creep stiffness at low-temperature (S"F)

decreases, and the temperature susceptibility decreases, improvements in all, with

rubber content. The negative aspect of increasing rubber content is that the high­

temperature (375"F) viscosity increases with rubber content, leading to pavement

8

compaction problems.

-Rubber particle size: Rubber with smaller particle size allows increased interaction

with the asphalt improving binder properties. It is theorized that this phenomenon

is explained by the smaller rubber particles having more surface area per mass and

volume than the larger rubber particles.

-Curing time: The binder properties improve with curing time within the range tested,

0-60 hours.

-Curing Temperature: The rate of asphalt-rubber interaction, and thus the rate of

improvement in binder properties, increases with higher curing temperatures within

the range studied, 3S0-400"F.

-Curing shear rate: A higher shear rate increases the rate of asphalt-rubber interaction

improving binder properties at a faster rate. The curing process is apparently mass­

transfer limited since a higher shear rate allows greater dispersion, and thus better

interaction, of the mixture.

Curing Temperature as a Variable

It was suspected that a higher curing temperature would allow a faster reaction rate

between the asphalt and rubber when being cured. Figure 2-1 shows that a higher curing

temperature produces a binder with a higher viscosity at 60°C. Also, the binder cured at the

higher temperature appeared to have a lower creep stiffness at -15°C as evidenced in Figure 2-2.

The improvement in the binder's physical properties can be attributed to the additional

amount of rubber going into the asphalt solution as a result of the higher curing temperature.

According to Figure 2-3, more rubber dissolves in the asphalt when cured at a higher temperature.

Curing Time as a Variable

By extending the amount of time a binder is cured, more rubber should go into solution

with the asphalt. This was expected to improve intermediate- and low-temperature properties and

reduce the high-temperature viscosity, all relative to the less-dissolved state.

Figure 2-4 shows a binder's temperature susceptibility, the slope of a In TJ'" vs.

9

'C c: .. (,) • 5l ill ';'

'" '0 So

u o

'" ":"

6000 ------------~~_r~~~~~~~~._~~~, o cured @ 4000F· Flna AC-10 with 10%1 TG-40 mes rubber

5000

4000

3000

2000

1000

0 0

• cured @ 3750F Cured at 3 different temperatures @ 500 RP

C cured @ 350°F ~

ij

0

B a 0

0

10 20 30 Curing Time (hra)

0

• =

40

J j

~ 1 1

= J

50

Figure 2·1. Effect of Curing Temperature on Viscosity 10% TG·40 and 90% Fino AC·I0

350 ~ ________ ~ ____ ~ ______ ~ ______ ,-______ ~

--- curad 0 350"F Fine AC·10 wllh 10"k TG-40 mesh rubber ••• 0(> ••• curad 0 37S"F Cured al 3 dlff .... nl t.mpmralu ... s 41 500 RP~

300 -e. curad 0 400'F -

'g OJ 250 r -lil .. IE 200 I-

50

o o 10

-

-I I I

20 30 40 50 CiI';ing. Tim. (hra)

Figure 2·2. Effect of Curing Temperature on Low Temperature Data 10% TG·40 and 90% Fino AC·I0

10

iii .r:: C­UI

'"

10 .~----------~ __ ~~-r __ ~~-r __ .-~-r~

B

, -6--. cured @ 400°F

"'-0' . cured @' 37SoF

--= . cured e 350°F

Fins AC·l0 with 10% TG-40 mesh rubber Cured at 3 diNerent temperatures @ 500 RP

~ I

""i J

1 •

.= 6 J E " E o u ~

" .., .., " ~ il ,. '0 ., ., 2i

4

o D····'···

2

10

·0 ..... " ...... "

--

20 30 Curing Time (hr.)

.. 0

..... ·0····

--

40 50

Figure 2·3. Effect of Curing Temperature on the Solubility of Rubber 10% TG·40 and 90% Fina AC·I0

10'

~ ~ 10' ~ c ,..: @

'i) 103

i • <='

10'

-.-48h,rr ···.··-24h. IT -e '6h, IT - ... ·TANK,IT

o 4Bh. HT o 24h. HT c 6h, HT 6 TANK. HT

• •• .'

Exxon AC-5 with 10% TG·l0 mesh rubber Cured at 375 Fend 500 RPM

......... Y = 7.6014 .. 15' 13487x R= 0.99991 ---Y= 1.41758-14' ~13330XI R=0.99995

- . Y = 4.00568015 • 13644x R= 0.99987 - .... Y = 1.96200·17 • 15057x R= 0.99997

10" 0.0020 0.0025 0.0030

1rr (I{"') 0.0035 0.0040

Figure 2·4. Intermediate and High Temperature Data 10% TG·I0 and 90% Exxon AC·5

11

lI(Temperature) correlation, decreases with an increase in curing time. In addition, the viscosity

of the binder decreases as curing time increases at high temperatures. According to Figure 2-5,

extended curing lowers the creep stiffness of the binder. Again, these improvements in the

binder's physical properties can be attributed to the additional amount of rubber that dissolves into

the asphalt as a result of the extended curing time (see Figure 2-6).

Rubber Amount as a Variable

To study the effects of the amount of rubber in a given binder, various samples were

prepared using two different concentrations of rubber, 5 and 10%. All other curing parameters

were held constant except for the amount of rubber in the binders.

Increasing the amount of rubber in a binder was expected to benefit some physical

properties but hinder other properties. The low and intermediate temperature properties benefit

with the additional amount of rubber. Figure 2-7 shows that the binder cured with 10% rubber

has a lower temperature susceptibility than the binder cured with less rubber. However, at high

temperatures, the binder with 10% rubber has a higher viscosity. Figure 2-8 reveals that the creep

stiffness is lower for the binder containing the larger amount of rubber;

Rubber Particle Size as a Variable

The effect of mesh size on the curing process was evaluated by preparing binders using the

various available mesh sizes. Theoretically, smaller rubber particles are much more easily

dissolved in asphalt than larger rubber particles. The smaller graded rubber reacts faster when

cured with asphalt because of the increased surface area. Therefore, if better dissolution improves

asphalt-rubber properties, then using smaller rubber particles benefits all physical properties of

a binder: a lower creep stiffness at low temperatures, a lower temperature susceptibility in the

intermediate temperature region, reduced viscosities at high temperatures (compared to the less­

cured state) and reduced curing time.

Figure 2-9 shows that the temperature susceptibility is lower for the binder cured with the

smaller graded rubber (-80 mesh rubber). This figure also reveals that the binder containing the

-80 mesh rubber has lower viscosities at the higher temperatures. From Figure 2-10, it is evident

12

150 r---~~~~~~T7~~~~~--~~~--~ --.10'% TG·10 I Exxon A -5 with 10% G-10 mesh rubber

~ I ~ ::. '",e " m """,00 ."

~ 100 ~ ., ., o

'" @

=:! .. ~ tID

.5 .. C II .. C o " .. 1: ... 2 ... ~ WI WI

is

Curing Time (hrml

Figure 2·5. Low Temperature Data 10% TG·I0 and 90% Exxon AC·S

J

10r-------~~~~~~~_r~~--~~~~ ---10% TG-10 I Exxon "COS with 10% TG-10 me.mh rubber

Cured at 375 F and 500 RPM

B t- -

6 I- -

4 I- .

'CL , , o 10 20 30 40 50

Curing Time (hrml

Figure 2·6. Solubility of Rubber in Asphalt 10% TG·IO and 90% Exxon AC·S

13

'0'

'0'

'0'

'0'

10'

10·'

"'-0 •.. '~:/o TG-40, IT i ........ Y = 2.26'e.' 6 • ""!' .48ge+04Xl R= , -II . 5/Q TG-40, IT :- . y = 7.473e-19 • eA 1 655e+84x R= 1 ---+- FIN A AC·'O TANK, IT ,-Y = 3.3230·20 • eA :748e+ 4x R=

o 10% TG-40. HT 3 • 5% TG-40. HT 1 o FINA AC·' 0 TANK, HT ~"

Fina AC·l0 wllh 5 and 10% TG-40 mesh rubber J Cured for 24 hours @ 375 F and 500 RPM ,

o 0 o • • • 0 o 0

o 0

e e

,.<6'

0.0020 0.0024 0.0028 0.0032 0.0036 1fT (IC"')

Figure 2·7. Effect of Rubber Amount on Temperature Susceptibility 5 and 10% TG·40 with Fina AC·I0

350 r-----~--~-r~~~~~~~~~,_~~-r, --5% Ta-10 Fin .. ACo1!l. lind TI ... Gator Blends • · .. <>···5% TG-40 Cured III 375 F lind 500 RPM

~ 300 -0 ... '0% TG·,O - ·10%TG-40 .

II) -• 4 TANK

... fa 250 '" Tank

~ ... 200

• i 150 -GO

;.

:: 100 -~ iii

50 -

/ o

Curing Tlma (hrs)

Figure 2·8. Low Temperature Data Fina AC·I0 lind TG Blends

14

-

-

-

u o

e­li.

!! .. .. ~ iii ... .. I!! u

, -e---- As·ao IT , ........ AS •• W: IT

j j 1 iExxon AC~5 and Rouse Blends

107 ~ ·AS-10,1T :Cured for 24 hours at 375 F and 500 RPM

10'

---'9"- . EXXON AC-5 TANK. IT Q AS·BO, HT II AS-40, HT o AS-10,HT ... EXXON AC-5 TANK HT

00 .0 8 o •

II e ,," ~" "

--- y = 3.36240,14 • e"l12866x) R= 0.99995 .. ....... Y = 1.5650·14 • e"(13167x) R= 1.00000 - . y = 1.0895.·14' e"f13410x) R= 0.99997 - - . y = 1.962 ... 17' e"(15057x) R= 0.99997

1 1 3 ,

1~:Ok02~0~----~0~.0~0~2~5------~0~.0~0~30~----.~0".ftOOk3~5~----~O~.O~O 11T (I{"')

Figure 2·9. Effect of Particle Size on Temperature Susceptibility Exxon AC·5 and 10% Rouse Blends

150 --+- 5% RS·10 "'-0-'- 5% Rs-40 -<J ·5% Rs.80 ~100k RS.10 ••• ... ···10"10 R5-40 -m ·10% Rs.80

A TANK

ElOIon AC-S and Rouae rubber blenda Cured .. t 375 F and 500 RPM

100 ~

o

50

o o

, , 10 20 30 40

Curing Time (hra)

Figure 2·10. Low Temperature Data Exxon AC·5 and RS Blends

15

-

50

that the binder cured with the smaller graded rubber has the lower creep stiffness. Again, these

improved physical properties can be explained by the fact that the smaller graded rubber goes into

the asphalt solution at a faster rate (see Figure 2-11).

Rubber Type as a Variable

Rubber used during experimentation was obtained from two sources. Tire Gator rubber

with mesh sizes of -10 and -40 was received from Granular Products located in Mexia, Texas.

A second supply with mesh sizes of -10, -40, and -80 was obtained from Rouse rubber located in

Vicksburg, MissiSsippi. Binders were cured to study the differences of these two rubber sources.

According to Figure 2-12, the binders cured with the Rouse rubber produced a lower

temperature susceptibility. Also, the binders with the Rouse rubber had lower viscosities than the

Tire Gator rubber at high temperatures. Figure 2-13 shows that the creep stiffness for the binders

cured with the Rouse rubber are lower than the ones prepared using the Tire Gator rubber. These

differences in the binders' physical properties are attributed to the amount of rubber going into

solution after curing. Figure 2-14 reveals that more rubber is dissolved in the asphalt for the

binder cured with the Rouse rubber. Such results suggest that the Rouse rubber reacts better with

asphalt than the Tire Gator rubber. For a given mesh size, the Rouse rubber has a finer gradation

than the Tire Gator rubber. This finer gradation of the Rouse rubber is thought to explain its

increased reactivity.

Mixing Speed as a Variable

Two blending speeds were used to cure the asphalt and rubber to see if an increased mixing

speed attained improved binder physical properties at a faster rate. Binders were cured using

mixing speeds of 500 or 1550 RPM.

Figure 2-15 shows that the temperature susceptibility for the binder cured for 2 hours at

1550 RPM is comparable to that of the binder cured for 24 hours at 500 RPM. The viscosities

at high temperatures show a similar correlation. From Figure 2~16, it is evident that the creep

stiffness for the binder cured for a short time at 1550 RPM is similar to that of the binder cured

for a much longer time at 500 RPM. The solubility experiment suggests that the rubber in the

16

10 --&- 10% Rs-ao

Exxon AC·5 and Rouse rubber blends "'0···10% AS-40 ,~ . 10°,0 RS·10 Cured at 375 F and 500 RPM

" f

~ B ~ ;;

r i "' c-

o>

" .E 6

'E ·0

~ 0" ." . -£

'E ---" -0 --" --4 .~- - -e--~ 0 ~ .a V .a o . :> Q." ~

'C ~

2 > 0 .. .!! Q

0 10 20 30 40 50

Curing Time (hi'll)

Figure 2·11. Effect of Particle Size on Solubility of Rubber in Asphalt Exxon AC·5 and RS Blends

2 ~ CD ~

C! ~

CI "i' VI

0 .!!: • .,.

10'

10'

10'

10'

10'

Fins AC'10 wHh 10% TG·10 and RS-10 mesh rubber

Cured for 24 hours at 375 F and 500 RPM 0"0/

•... /

Q •••••

.... / ...... /

....... J1 .. ,r-

... / ....... ~> /

--y = 2.114e-13· e"{12S21x) R= 0.99999 ......... Y = 7.6014e-15 • e"I13487x) R= 0.99991 - . Y = 1.962e-17 • e"I1S057x) R= 0.99997

10' 0.0026 0.0028 0.0030 0.0032 0.0034 0.0036

11T (1<"')

Figure 2·12. Effect of Rubber .Type on Temperature Susceptibility Fina AC·10 with 10% TG·I0 and RS·I0

17

u •

350 ----~~~~~~,_~~~,_-----r~~~~, __ 10~~ TG·l0 "'-0···10% AS·10

" TANK

300 r Fin. AC-l0 with 10% TG-l0 and

10% RS-10 mesh rubber Cured at 375 F and 500 RPM

'g 250 .. u ~ ., lE 200

III

o 0

..•..• <P=." ~ ..... 6= ....... = ......... ==e===~:::::------ii a ·· .. · .. ·e····· .. ··· .. ··· .......... 0............... ,..

" ........ P

150

100

50

°0~~~~~10~~~~2~0~~~~30~~~~4tO~~~~5·0 Curing Time (hrml

Figure 2·13. Low Temperature Data 90% Fina AC·I0 with 10% TG·I0 and 10% RS·I0

10r-------~~~~~~~-r~~~-r~~-r~ --6-10% R$-10 I ···.0···10% TG-10 I

s

Fins AC-10 with 10% TG·10 and 10% R!l-10 mash rubber

Curmd III 375 F and 500 RPM

6 I-

4 I-

v:: .... -.. .., ............. .

2 I- ..... ., .............. .

0.······· .. ··". .... · ............ .

o ......... I I I

o 10 20 30 40 Curing Time (hrml

-

.

-". .• 0

50

Figure 2·14. Effect oC- Rubber Type on the Solubility of Rubber 90% Fina AC·I0 with 10% TG ·10 and 10% RS ·10

18

u ., :[l .. ~

C! ~

@

';' ., C .So -.,.

() D ., ~

0 .., c .. " II ., c CD

GIl -II c. ::IE -.. ., ., c ., iii "-II I!! CJ

10' r-----~--~~~~--~~~_r~~--r-~~~-r_; I --- cured 811550 RPM tor 2 hrs

10'

10'

10'

10'

10'

10'

I ........ cured al 500 RPM ror 24 hrs r -= . FINA AC-10 TANK

Fin. AC·10 with 10% TG-10 mesh rubber Cured at 1550 RPM for 2hr and

500 RPM for 24 hrs

.. /

/

/ ... / ....•

/u

/ • /'

......... y= 1.57318-16- 14995x R=0.9999B --y = 3.5056e·16 - ~14B34XI R= 0.9999B

-- . Y = 3.32268·20 - 174B3x R= 0.99999

10' ~~~~~~~~~~~~~~~~--~~~~~~ 0.0026 0.0028 0.0030 0.0032 0.0034 0.0036

1rr (1("')

Figure 2-15. Effect of Mixing Speed on Temperature Susceptibility Fina AC-IO with 10% TG-IO

350 --0- cured 0 500 RPM

, , 0 cured 01550 RPM • TANK

300 -Fins AC-10 wHh 10% TG-10 mesh rubber

Cured lilt 375 F mnd lit 2 dlllorlllnt shomr ",toa 250 - -

-- Tank 200 -150 _0 0

00 • 0 - 0

100 -

50 -

00 ,

10 20 30 40 50 Curing Time (hm)

Figure 2·16. Effect of Mixing Speed on Low Temperature Data 10% TG-I0 and 90% Fina AC-IO

19

binder cured at a high mixing speed goes into the asphalt solution at a faster rate than the binder

cured at a much slower mixing speed (see Figure 2-17). From this it would appear that the curing

time could be reduced by using higher mixing speeds.

Asphalt Type as Variable

Numerous binders were prepared using three base asphalts: a Fina AC-lO, an Exxon AC-

5, and a Murphy/Sun AC-IO. According to literature, a softer asphalt reacts with rubber at a

faster rate. This was clearly evident during experimentation. The binders prepared using the

Exxon AC-5, which is softest base asphalt, yielded superior physical properties when compared

with the other two asphalts.

General Conclusions about Curing Asphalt with Rubber

The extent to which the rubber dissolves into the asphalt is very dependent upon the curing

environment. Under the curing conditions studied, dissolving the rubber was found to improve

the properties of a binder. However, future work should be done to verify this conclusion, since

it is doubtful that complete destruction of the rubber molecule, and thus its elasticity, is desirable.

That is, the optimization of binder properties is very dependent on the extent to which the rubber

particle is devulcanized and/or depolymerized.

In this study, the rubber dissolved faster with a higher curing temperature, a longer curing

time, and a faster mixing speed. If dissolving rubber is desirable, the standard curing temperature

of 350"F and curing time of I hour (Takallou and Takallou, 1991) may not be optimal, since

increasing temperature and curing time greatly increases the rate of rubber degradation.

Furthermore, the shear rate of mixing is a very important variable which should be studied in the

future.

The chemical composition of the asphalt, the rubber mesh size, and the rubber content

were all determined to be important variables. Apparently, increasing the aromatic content of an

asphalt increases the rubber and asphalt reaction. Faster reaction rates can also be obtained by

using finer rubber gradation, with increased surface area per mass of the smaller particles allowing

for faster reaction rates. Finally, the benefits of adding rubber were directly related to the rubber

20

10--~~~~~~~~'-~-r~~~-r'-~-r~ -+- cured @ 500 RPM

... -0 .. cured @ 1550 RPM

Fin. AC-l0 with 10% TG-l0 mesh rubber Cured at 375 F and at 2 different shear rates

j J

O~~~~~~~~~~~~~~~~~. o 10 20 30 40 50 Curing Time (hm)

Figure 2·17. Effect of Mixing Speed on Solubility of Rubber in Asphalt 10% TG·IO and 90% Fina AC·IO

content, over the range of content studied.

AGE BLENDS

Asphalt and rubber blends were prepared under various curing conditions and were aged

in the pressure oxygen vessel (pOV, see Appendix A for description of POV apparatus), or

equivalent device, adequate to evaluate aging rates of typical road conditions. Three asphalts·

Exxon AC·5, Exxon AC-lO, and Fina AC-IO, and twelve asphalt-rubber blends cured at 375"F

for 12 hours and 500 RPM were aged in several POVs and the ENV room. These samples are

listed below:

Asphalts: (Total of 3)

Fina AC-lO

Exxon AC-5

21

Exxon AC-IO

Asphalt-Rllbber Blends: (Total of 12, 3 asphalts x 4 blends)

4 blends of each asphalt:

2 blends: 5 % and 10% TG-40 B, where -B stands for retreading shop buffings,

which were used in the feedstock to produce this rubber

2 blends: 5% and 10% RS-40

The POYs were utilized at three temperatures- 190, 200, and 21O"F, under atmospheric

air for up to 2 months, to obtain kinetic data on each of the binders which will subsequently be

verified with 140"F data. The ENV room was maintained at 14O"F with air at atmospheric

pressure. The ENV room samples were aged up to 7 months.

The POY and the ENV room samples have been analyzed using FTIR and the Carri-Med

rheometer. Furthermore, bending beam analysis was performed on 15 tank (TK) (unaged) blends

and the corresponding 15 blends that have been aged approximately 2 months at 140"F in the ENV

room.

Generally, initial results show that rubber is beneficial to a binder's oxidative aging

characteristics, with the hardening susceptibility of an asphalt-rubber binder being less than the

base asphalt of that binder. Additionally, the hardening rate of an asphalt-rubber binder is less

than the base asphalt of that binder. Preliminary bending beam results show that the creep

stiffness increases with aging time. Pertinent results from the aging tests are given below.

Hardening Susceptibility

Figures 2-18,2-19, and 2-20, representing Exxon AC-5, Exxon AC-10, and Fina AC-10

asphalt-rubber blends that were POY-aged at temperatures of 190, 200, and 210"F under

atmospheric air, show that the hardening susceptibility, the slope of a log viscosity (T]*) versus

carbonyl area plot, decreases and thus improves, with increasing rubber content. Figures 2-18,

2-19, and 2-20 also show that the amount of improvement in the hardening susceptibility is asphalt

dependent.

The hardening susceptibility was also determined to be independent ofPOY-temperature

22

~ ., '0 .e: (,)

c

0 II)

'C r: .. u II

~ ., ~

C! ~

iii • ...

-II> .. '0 ... -U

0

c '" 'C c " U II

;!I f! C! .. iii i:-

10'

10'

10' 0.6

--e- EXX AC-5 EXXON AC·5 AND BLENDS

POV·AGED DATA

I""" . 5/95. EXX AG·5, TG -40S ...,....,~~~..,~~~"T'~~~..., I I - 0- '10/90, EXX AC-5, TG -408 Blends cured at 375 of and 500 rpm

for 12 hours under N~ . t:. '5/95, EXX AC·5, AS ·40

.••• Q- .. 10190. EXX AC-S. AS ·40

POV·Aged at 190, 200, and 210 OF with Atmospheric Air

o

--y c 225. I • 0"(2.85'1 R

... o

o 0

O.B

- . y = 514.2' 0"(2.552>1 R 0.9746

..• y .432.9' 0"(2.189'1 0.94B

·········y=105S·e"(1.711x)R 0,9767

1 1.2 1.4 1.6 1.B CARBONYL AREA

Figure 2-18. Hardening Susceptibilities of Exxon AC-5 and Blends

___ EXX AC-l0

-e .5/95. EXX AC-l0. TG-40

EXXON AC·l0 AND BLENDS POV·AGED DATA

10' - .. '10190. EXX AC-l0. TG -4OB I-...-..,..."T-.-r::-...-..,......,.-.-~ c. '

10'

..•.. 5/95, EXX AC-l0, RS -40 '/. . 0

/.4" ~' · ••• 90···10190. EX)( AC-10, RS -40 c~ ... ~ ~.;. .. (?.v

POV-AgedaI190,200,and210 oF ~o·.6 ~::-: ..... . with Atmospheric A1r_ JJ..~ I{.~.:::'" o-v

"';1;" 0.4'" .

-

o

o

o o

o /"lfI:'. .. oM' 1J./.. 6 . ....vv

.6 c· 9"0"

o

o o 0 0

Blends cured at 375 of and 500 rpm for 12 hours under N, -

--YIll205.1 • e"(3.524x) R=O.9768

- • Y II: 1062 • e"'t2.821x) R= 0,9482

- - • y =- 943.4 • eA(2.674x) R= 0.9164

..•.• y = 1051 • ~(2.7SSx) R=O.9809

••••••••• y = 1446· e .... {2.287x) R=O.9767

CARBONYL AREA

Figure 2-19. Hardening Susceptibilities of Exxon AC·I0 and Blends

23

~ '" (; ~ u • 0

'" 'C c: co

" ..

'0'

, 0'

~ - 10" "l -7ii '",

I ~ FINA AC.10 FINA AC·' a AND BLENDS

POV·AGED DATA : -= ·5195. FINA AC·10. TG -408 i-: ~"""~~.....,..~~--r~""-"''''''3 , - .... 10/90, FINA AC·10. TG -40B .,

" t.. '5/95. FINA AC·1Q. AS -40 ~ ••. Q- •.• 10/90. FINA AC-1Q. AS .40 ~ 1

POV·Aged al 190. 200, and 210°F 0 .--;;. ;.;.= - '" 0 J with Atmospheric Air .............. ~- -L., ~ • 1"

o o

o '§:: ~- i. ~.L.. V V a ~-.$4. v

o :..c-o ...... ,w' v -- y = 222.2· e"(4.029x) A

Q.. _.:.:.:.::~t~t.~.·.... _ . y = 1001 • eJl{2.704x) R

0.9756

.9887

- - . y = 1963 • 0"(2.187x) R= .9731

...• y = 658.3 • 0"(2.861x) R 0.9584

......... Y = 1267 • O"(2.254x) R 0.953

Blends cured at 375 OF and 500 rpm lor'2 hours under N

2

CARBONYL AREA

Figure 2·20. Hardening Susceptibilities of Fina AC·IO and Blends

within the range studied, 190-21O"F. This is shown by Figures 2-21,2-22, and 2-23, representing

Exxon AC-5, (5/95, TG -40, Exxon AC-5), and (10/90, TG -40, Exxon AC-5) aged at the above­

mentioned POV conditions, with the scatter of the data points around the straight line are no worse

for the asphalt-rubber blends than the asphalt. This conclusion agrees with previous work by our

research group that showed that the hardening susceptibility of an asphalt was independent of

POV-aging temperature (Lau et al., 1992). However, this conclusion contradicts earlier asphalt­

rubber high-pressure aging results, obtained using high-pressure (300 psia) oxygen, that showed

the hardening susceptibility was dependent upon the POV-aging temperature (Bullin et al., 1994).

Further analysis yielded that the hardening susceptibility of an asphalt-rubber is however

not independent of temperature over the temperature range studied, 140-210"F, with the 14O"F­

aged data and hardening susceptibility line lying distinctly above and away from the POV -aged

data and hardening susceptibility. This is shown in Figure 2-24 for an Exxon AC-5 asphalt-rubber

blend. This phenomenon complicates the mathematical analysis required to investigate the kinetics

of asphalt-rubber oxidation. The difference in the activation energies of the two distinct

24

-;-~

"0 ,e, U

D ., '" "tl C .. u .. ~ .. ~

C! ~ -.. .".

-;-.. "0 ,e, I.l c ., '" "tl C II u II

~ I!! C! ~

7ii • .,.

10'

10'

10' 0.7

EXXON AC·5 POV·AGED DATA

I -e- EXX AC-5 -- Y = 225.1 • e'(2.85x) A= 0.970

POV-Aged at 190,200. and 210 'F with Atmospheric Air

o~ o 0

0_8 0.9 1 1.1 1.2 CARBONYL AREA

I

1.3

Figure 2·21. Hardening Susceptibility of Exxon AC·5

10'

10'

EXXON AC·5 WITH 5% TG-40B POY·AGED DATA

I ---- 5195. EXX AC-5, TG -408 I --y = 514.2 • e"(2.552x) A= 0.9746

POY·Aged at 190, 200, and 210 OF with Atmospheric Air

Blends cured at 375 OF and 500 rpm for 12 hours under N,

1 0~.9L"""..I..L.l1"""'-'-1e-.f,.1 ..... ~1.-!:2..I..L-'--;1-!.3,..... ...... 1e-.f,.4 ........ ....,.1.-!:5,....-'-'1,...6~ ..... ""1. 7

CARBONYL AREA

Figure 2·22. Hardening Susceptibility of 5/95 Exxon AC·5 and TG ·40B

25

-;-Ul

'0 .e u • 0 CD

" " " " " ~ " -C! --CD ..,.

-;-.!! 0 ... -U

0

ll! ... c ID .. .. ~ E C! --ID

• .,.

10'

10'

10' O.S

10'

10'

10' 0.6

EXXON AC·5 WITH 10'10 TG -406 POV-AGED DATA

-<>- 10/90, TG ·40B, EXXON AC·5 ,-- Y = 963,2 • eAI' ,BBx) R= 0,973B

POV·Aged al , 90,200, and 210 'F with Atmospheric AIr

c c

a

Blends cured al 375 of and 500 rpm for 12 hours under N,

j

1

1 1.2 1.4 1.6 1.S CARBONYL AREA

Figure 2·23. Hardening Susceptibility of 10/90 Exxon AC·I0 and TG ·40B

EXXON AC-S with 5% TG -40B POV- and ENV-AGED DATA

__ 5195. EXX Ac;.S, TG o4OB, POV·DATA

...... • 5195, EXX Ac;.S, TG o4OB, ENV('40 °F}-DATA

POV·Aged at 190, 200, and 210 OF lInd ENV·Aged at 140 OF

with Atmospheric Air

~ • •

• •

•

o 0

? • --y c 514.2 • e"(2,552x) R= 0.9746

O.S 1

- ·yc43S.7· e"(3.164X) R= 0.9532

Blends cured at 375 OF and 500 rpm for 12 hours under N,

1.2 1.4 1.6

CARBONYL AREA

1.S

Figure 2·24. Comparing the Hardening Susceptibilities of POV.aging and ENV.aging

26

components of the asphalt-rubber blend may explain this phenomenon. Furthermore, the

hardening susceptibility is improved by the addition of rubber at 140°F. This is shown in Figure

2-25 for Exxon AC-5 and Exxon AC-5 asphalt-rubber blends.

Aging Rate

Figures 2-26,2-27, and 2-28, representing various asphalt-rubber blends aged at the three

POV-temperatures; 190, 200, and 21O"F, show that the aging rate, the slope of a carbonyl area

versus time plot, increases, and thus becomes worse, with the addition of rubber. The amount

of the increase in aging rate is apparently not a function of the rubber concentration. Figure 2-29

shows that the aging rate at 140"F also increases with the addition of rubber, with the aging rate

increasing with increasing rubber content.

The aging rate when plotted versus the inverse of the absolute aging temperature, lIT,

yields an activation energy based on aging rate. Figure 2-30 shows that the activation energies

(magnitude of the slope of the line), as predicted by the POV-aged data, decrease with the addition

of rubber. The decrease appears to not be function of the rubber concentration. Additionally,

Figure 2-30 shows that the activation energies obtained from the POV -data predict a 14O"F aging

rate that is much higher than the 14O"F aging rate that was actually obtained. An in-depth analysis

of numerous asphalts and asphalt-rubber blends is required to verify this finding.

Hardening Rate

Figure 2-31,2-32, and 2-33, representing various asphalt-rubber blends aged at the three

POV-temperatures- 190, 200, and 210"F, show that the hardening rate, the slope in a plot of log

TJ* versus time, generally decreases with the addition of rubber and thus, the rubber is beneficial

at the elevated temperatures of the POV. Figure 2-34 shows that the hardening rate activation

energies, the slope of a log (hardening rate) versus the inverse of the aging temperature, lIT, are

lowered by the addition of rubber .. Additionally, Figure 2-34 shows that the activation energies

obtained from the POV-data predict a 14O"F hardening rate that is much higher than the 140"F

hardening rate that was actually obtained. The activation energies of Figure 2-34 also indicate

that, at low temperature, the hardening rate of the asphalt rubber binder will be l1ll'ger than the

27

" '" "0 ::: (.)

0

0 CD

'C

" to

" .. ~ " -~ -ii i:-

10'

10'

1.4

1_2

1

0.8

0.6

r--::===::-----, EXXON AC-S AND BLENDS I--e- EXXON AC-5 ! ENV room (140 of) DATA --E ,5/95, EXXON AC·5, TG -408

- (I- ·10/90. EXXON AC·5, TG -408 -- y::: 171.7 • e"{3-499x) R= 0.9923

· A ·5/95. EXXON AG·5, RS -40 - 'y=441.9"e"(3.157x)A=O.9534

"';)-"'10/90, EXXON AC-5, RS -40

POV-Aged and ENVAOOM-Aged with Atmosphenc Air

. y::: 667.5' e"(2.59Sx) R= 0.9721 ~

. y = 401.7' efl (2.7x) R= 0.9459

........ y = 550' e"(2.n7x) R= 0.9873

... Blends cured at 375 OF and 500 rpm

for 12 hours under N,

CARBONYL AREA

Figure 2·25. Hardening Susceptibilities of Exxon AC·5 lind Blends

• EXX AC-5, lK • 5/95, EXX AC-5, TG -4IlB, lK

EXXON ACoS AND BLENDS 1ao OF DATA

• 10190, EXX AC-S, TG -4IlB, lKh-.,.......-...-..... ....,.-,..... .... ...--,.-, • 5/95, EXX AC-5, RS -40, lK • 10190, EXXAC-S, RS-40, lK

-e-EXXAC-5 -e . 5/95, EXX AC-5, TG-4IlB - ... 10190, EXX AC-5, TG-4IlB .••.• 5/95, EXX AC-5, AS-40 .... " ... 10190, EXX AC-5, RS-40

.... fi v ,,:/.'

.···SV .' V. "fl" ...... ~·4··· .~.

POV-Aged at 190 'F .;;:. .' . wHh Atmospheric Air .. ,y,;":--.....

0'11·,' .... ", "

~ .' . ... . .. --y • 0.5499 + 0.03266>< Roo 0.9994

- . 'I- 0.666 + O.03867x R. 0.9965

- - -y.O.6204+0.04196xR.O.9984

..... y. 0.5414 + O.04493x R= 0.9964 lends cured at 375 OF and 500 rpm

for 12 hours under N, ...... • .. Y -0,6467 +O.0426x R.O.seas

0.4 O!;-------.............. 7:S ............................ "r.O ... --'--'--'-,.-ls,.... ........ '--'--'--;;lzo TIME (DAYS)

Figure 2·26. Aging Rlltes of Exxon AC·5 lind Blends lit 190 OF

28

..: w a: ..: oJ > Z o ID a: ..:

1.6

1.4

1.2

1

t.l 0.8

c w

0.6

0.4

2.5

2

a: 1.5 C(

oJ > Z o

! 1

t.l

0.5

o

• EXX AG-10, TK EXXON AC·10 AND BLENDS

• 5/95, EXX AC-l0, TG -408. TK ! 200 of DATA • 10/90. EXX AC-1O. TG -40B. TK' , • 5195, EXX AC-l0. RS ·40, TK i

'1 T 10/90, EXX AC-10, RS -40, TK 9 -e-- EXX AG-' 0

- '5/95, EXX AC-10, TG ·40B _0 V -~ . 10/90. EXX AC-l0. TG -408 " ./'

" ·5/95, EXX AC-l0, AS -40 0 - .,/ 1 ... v. ... 10/90. EXX AC-l0, AS -40 - '" J

, ----.~ I .- r:r -' <;' ./ J POV-Aged at 200 OF -, ' 'l-, with Atmospheric Air "

Blands Curad at 375 OF and 500 rpm for 12 hours under N,

5

0 _./ V~·'

c

o

--y = 0.6452 + O.03172x R= 0.9 35

- • y = 0.8072 + O.04143x R= 0.9 96

- - -y = 0.927 + O.04082x R= 0.9

.... -y = 0.7944 + O.03915x R= O. 23

......... y • 0.956 + 0.03383x R= 0.9 4

10 15 TIME (DAYS)

Figure 2·27. Aging Rates of Exxon AC·I0 and Blends at 200 OF

• FINA AC-10, 1l( • 5/95, FINA AC-l0, TG -408, 1l( • 10190, ANA AC-l0, TG -408, 1l( • 5195, FtNA AC-l0, RS -40, TK • 10190, FtNA AC-l0, RS -40, 1l(

-e- FtNA AC-l0 -e . 5/95, ANA AC-l0, TG-408 - .. ,10190, ANA AC-l0, TG-408 ..•.• 5195, ANA AC-l0, RS-40 .... " .. ·10190, FINA AC-l0, RS-40

POV·Aged at 210 OF with Atmospheric Air

Blends cured at 375 OF and 500 rpm for 12 hours undar N,

FlNA AC·l0 AND BLENDS 210 OF DATA

o

--v .0.6111 + 0.06642x A= O. 5

- - . y. 0.9321 + O.07479x R. O. 66

.. -y I:Il 0.9311 + 0.07003)( R= 0, 72

....... _- y 1:1. 0.9096 + O.07377x R= O. 93

°0L-~~~~5~~~~~1~0~~~~~1~5~~~~~2~0

TIME (DAYS)

Figure 2·28. Aging Rates of Fina ACI0 and Blends at 210 OF

29

>: .. ~ l!! c ;;. c 0 .., ~

" (J -.! " II: II>

i, C

"" w II:

"" -' > z 0 III II:

"" (.)

- - • y = 0.6634 + O.001317x R:;: 0.9882 EXXON AC·5 AND BLENDS

140 'F DATA

1.2

1.1

1

0.9

O.B

0.7

0.6

0.5

0.4 0

0.1

0.01 r-

.. v = 0.6873 ... O.001912x R= 0.9454

. y ::: 0,7167 ... O.0020B7x R= 0.9722

. y = 0.6979 ... O.001546x R= 0.9802 ...-::; .... 0

B.:;-'w-. y = 0,7007 + O.002136x R= 0.993 0 /_ _.- ~ -t -... -~ -'

0..-;::::"--_ "...'" ____ " ; .J

......-::: 17 "'tJ. 0.--" S- j --- ~ ~ .....-:~.- ____ -c ::! .....8"" :; .... ~ l.> _ - -=--=-----cccc-=-::--.::L--

~, .... ::;:,. ____ " = ..e- - c: c • EXXAC·5 TK :: l!. I') .J.I - .. 5/95, EXX AC-5, TG ·408. TK

• 10190. EXX AC'5, TG -406. TK: • 5/95. EXX AC·5. AS -..10, TK I ... 10190. EXx AC·5, AS -40. TK o

C IJ = Inlial Jump Region o EXX AC-S, IJ

ENV.Aged al140 OF wnh Atmospheric Air

Blends cured al 375 OF and 500 rpm for 12 hours under N,

50 1 0 150 TIME (DAYS)

Iii S/95, EXX AC·5. TG ..os, U lSj 10190, EXX AC·5, TG -408, IJ ~ 5195, EXX AC·5, RS -40, U ... 10/90, EXX AC-5, RS -4(], U

--0- . EXX AC-S -.r:; .. 5195, EXX AC-5, TG-4OB --0 ... 10190, EXX AC-s, TG-4QB --6 . 5195, EXX AC-5, RS-40 - V- • 10190, EXX AC-5, RS...co

200 2 0

Figure 2·29. Aging Rates of Exxon AC·S and Blends at 140 OF

Enon Ac-5 and Blands

, _EXXONAC-5

~ -e . 5195. TG -40 - .. ,10190. TG-40 -.0- ·51115. RS -40 I .. • ..... ·10190. AS-40

co EXXON AC-5. 14O"F

'" 5195, TG -40. 140'F Blends cured al 375 OF and 500 rpm • 10190, TG -40, 140°F

for 12 hours under N, A 5195. RS -40. 140'F

POV·AGED al19O, 200, and 210'F • 10190. RS -40. 140'F I _

and ENVROOM-AGED al140 OF under Air ENV-Room

--y • 5.7_ • 0"(-e862x) Ra 0.9904 140'F Data

- .y _l.tKl6&+05· 0"(-5524.) RaO.U16 I - - . y. 6340 ·0"(-4311.) R. 0.1183 ..

- - . y _ 23.93 • 0"(-2264.) R. 0.9965 ~ • •

0.00J.0026

......... y. 60.27 • 0"(.2612><) R. 0.9584 , , 0.0027 0.0028 0.0029 0.003 0.0031

1fTemp (11K)

Figure 2·30. Aging Rate Kinetics Plot of Exxon AC·S and Blends

30

'C C .. U

c

o

'" iii

'C

Ii u

D

Ii! iii '.,.

--y = 3214· e"{O.1479x) R= 0.9929

• y = 6732 • e"{O.1411x) R= 0.9938 FINA AC-l0 AND BLENDS

190 'F DATA

le'-~~~~~~~~~~~,-~-r~~-,-~~~-r-, .----.8

. -y=6630"eJ"{O.138Sx}A=O.9973 __ r-,.i- ~ .. -9

"."' .... Y = 9586' e"(O.09994x) R= 0.993 0 _.-~. . v - - ----- .

10'

10'

10' o

10'

10'

10'

10' o

0- - ~ ~.,

V

• Tank Samples

POV-AGED AT 190 'F wfth Atmospheric Air

5

Blends cured at 375 of and 500 rpm for 12 hours under N2

10 Time (Daya)

• FINA AC-l0, TK II 5/95, FINA AC-l0, TG -40, TK • 10190, FINA ACrl0. TG -40, TK " 5/95. FINAAC·l0. RS-40, TK • 10/90, FINA AC-10, RS -40, TK

-e- FINA AG-l0, 190F --a -5/95, FINA AC-l0, TG 0040 - -- ·10/90, FINA AC-10, TG-40 ..•.. 5I9S, FINA AC-10, RS-40 .... ~ .. ·10/90, FINA AC-10, RS-40

15 20

Figure 2·31. Hardening Rates of Fina AC-10 and Blends at 190 OF

• EXX Ae-S, TK • 5/95, EXX AC-S, TG -40, TK EXXON AC-5 AND BLENDS

200 OF DATA • 10/90, EXX Ae-S, TG -40, TK • 5/95, EXX Ae-S, RS -40, TK v 10190, EXX AC-5, RS -40, TK 1-.,-,..,..--,.-.-,-.,-,..,.....,.--,-,-.,

-<>- EXXON Ae-S -s . 519S, EXX Ae-S, TG -40 Blends cured at 375 of and 500 " m - ... ·10190, EXXAC-S, TG -40 for 12 hours under N, - -. - . 5/95, EXX Ac;.s, RS-40 -<1- ,10190, exx AC-5, RS-40

... f---- Tank Samples

, 5

--y .. 967.7 • e"(O.1247x) R. 0.995

_ .y-ms'0"(0.1329xIR.O,9907 c

- - - y - 3060 • 0"(0.11.) R. 0,9901

- - - - oy .1610· e"(O.1156x) RI: 0.9963

- - • y - 3027' 0"(0,10320<) R_ 0.9979 ,

10 15 Time (Days)

20

Figure 2-32. Hardening Rates of Exxon AC·5 and Blends at 200 OF

31

" c .. (.)

o

'.,.

.. ii II:

'" .5 c .. ... ~ .. :c

10'

10'

10'

10' o

EXXON AC·l0 AND Bt.ENDS 210 'F DATA

Tank Samples

5

II EXX AC·10, TK m 5/95, EXX AC·l0. TG -40, TK • 10190. EXX AC-l0, TG ·40, TK • S/95. EXX AC-10. RS ·40. TK " 10/90. EXX AC-1Q, RS -40, TK

-E-- EXXON AC-10 - 5/95, EXX AC-l0 TG -40

c c - (>- . 10/90. EXX AC-l0. TG-40 t. ·5/95, EXX AC-l0 RS -40 Q-. ·10/90. EXX AC-l0, AS -40

POV-aged a12,0 OF with Atmospheric Air

Blends cured at 375 OF and 500 rpm for 12 hours under N2

--Y = 1492' O"{O.'844x) A. 0.94'2

- . y = 1.B736+04 • &",{O.126x) R= 0.9647

- - - y • 1.4651Hll4 • 0"{0.1443x) A. 0.9876

.... -y. 1.1 171Hll4 • 0"{0.158x) A. 0.9759

......... Y • 1.21l41Hll4 • 0"{0.1273x) A. 0.9876

10 15 Time (Dsys)

20

Figure 2·33. Hardening Rates of Exxon AC·I0 lind Blends at 210 OF

ElOIon Ac-5 and Blanda

1 Ha. !ening R~te Activation Energies -e- EXXON Ac-5

-e . 5195. EXX AC-5. TG -10. POV DATA

POf/·AGED at leo. 200. and 210"1' - .. ·10190. EXXAC-S. TG-IO. POV DATA ...... ·5195. EXX AC-S. AS -10. POV DATA .. • ..... ·10190. EXXAC-S. AS-IO. POV DATA and E VROOM·AGED at 14O'F under Air

0.1 l:-

0.01 I:-

~---. ..... ~.-.. ~

• EXX Ac-5. 14O'F DATA

• 5195. EXX AC-5. TG -lOB. 140 OF DATA • 10190. EXX AC-S. TG -lOB. 140 OF DATA

• 5195. EXX AC-S. AS -10. 140 OF DATA

• 10190. EXX AtrS. RS -40. 140 OF DATA

Blends cured at 375 OF and 50 rpm

__ y. 1.2048+10. 0''{.9301.) Ro 0.9792 for 12 hours under N,

- :y _3.1970+06' 0"{-/l249x) Ro 0.9821

- - • y _ 5.0120+06 • 0"{-6479.) R. 0.9911

- •• y. 3.3720+07' 0"{·7163.) Ro 0.957

......... y. 3.550+07 • 0"{·7247.) R.O.9339

/-ENV·Room

140"F Data

0.001 , , , ,

0.0027 0.0028 0.0029 0.003 llTemp (11K)

Figure 2·34. Hardening Rate Kinetics Plot of Exxon AC·5 and Blends

32

corresponding base asphalt. This prediction from the POY elevated-temperature data is

contradicted by the 140°F ENV-Room data in Figure 2-35,2-36, and 2-37, which represent the

3 base asphalts; Fina AC-IO, Exxon AC-5, and Exxon AC-1O aged at 140°F. Figures 2-35,2-36,

and 2-37 show that the hardening rate (slope) at 140°F is not a function of rubber content. The

data that was in the initial jump region is labeled with U in the figures. The initial jump region

is defined as the time before In Tj" is linear with time. An in-depth analysis of numerous asphalt

and asphalt-rubber blends is required to verify this finding.

Although an asphalt-rubber binder hardens as fast or faster than its base asphalt at 140"F,

this hardening may not be as detrimental to the asphalt-rubber binder as it is to the base asphalt.

The hardening is not as detrimental because the rate of change of elasticity of the binder, as

measured by delta, 0, (A material with 0=90" is perfectly viscous, whereas a material with 0=0°

is perfectly elastic.) with aging time is more negative for the asphalt-rubber binder than the base

asphalt. This is shown in Figures 2-38, 2-39, and 2-40, representing the 3 base asphalts; Fina

AC-IO, Exxon AC-5, and Exxon AC-IO aged at 140"F, and implies that for the same amount of

aging time, the elasticity of an asphalt-rubber binder increases more than the elasticity of its base

asphalt.

Additionally, several asphalts and cured asphalt-rubber blends are currently being aged in

the ENV room and will be POV aged as well. These samples will be analyzed to determine the

effects of rubber content (10 and 20%) and high shear rate of curing on aging properties. These

samples include:

Asphalts: (Total of 4)

Fina AC-I0

Exxon AC-5

Exxon AC-IO

Fina Demex Resin

Asphalt-Rubber Blends: (Total of 8, 4 asphalts x 2 blends)

2 blends of each asphalt:

with 10% TG-40 Buff

with 20% TG-40 Buff

33

." c: .. (.) • lil iii '.,.

i

10'

10'

la'

10' o

10'

¥ 10' I-

j C! -." c: .. ~ 10' ~

lil iii '.,.

10' o

FINA AC·l0 AND BLENDS

ENVROOM·AGED AT 140 of UNDER AIR _ ~~~ v

_o-::':::::_:&-" 0- .-0- =.~E·;"'-

o ~-:iI2:!?-' ti - _ _ &

o

oX J::: IJ = Initial Jump Region

• FINA AC-10, TK III 5110, FINA AC·l0, TG -40, TK

o o

Blends cured at 375 of and 500 rpm for 12 hours under N,

• 10/90. FINA AC·10, TG -40, TK ' .. 5/95, FINA AC·10, RS --40, TK II

• 10190, FINA AC-l0. RS -40. TK o FINA AC-10, IJ ' c 5/95. FINA AC-l0. TG -40.IJ I --Y = 5258 ' ~0.009327x) R= 0.9953 o 10/90, FINA AC-l0, TG --40, IJ • 5195. FINA AC-l0. RS -40.IJ - • y =: 8581 • e"(O.009558x) A .. D.99n

- - • Y = 1.3078+04' ~0.OO7479x) R. 0.996 • 10190. FINA AC-l0. RS -40. IJ

-<>- FINA AC-l0 -e . 5195. FINA AC-l0, TG-40 - .. ·10190, FINA AC-l0, TG-40 - •. y • 911 I '~0.00B449x) R. 0.991

-<I •. 5195, FINA AC-l0, RS-40 ....... ·10190, FINA AC-l0. RS-40 ......... y. 1.1_' ~0.OO7067x) R. 0.9808

50 100 150 200 250 Time (Days)

Figure 2·35. of Fina AC·IO

Hardening Rates and Blends at 140°F

,::.:..-="'EXX,:,..,"""-:':-S.-:TK,.,....---, II 5ID5, EXX AC-5, TG -40, TK

EXXON Ac.5 AND BLENDS • l(W(), EX)( IDS. TG..co, TK .. 5195, EXX AC-5, RS -40, TK • 101B0. EXX AC-5, RS..co, TK , o EXXAC-S, U

ENVROOM-aged at 140 OF with Atmospheric Air

o 5J95, EXX AC·5, TG..co, U o 101B0, EXX AC-5, TG -40, U A 5ID5, EXX AC-5, RS ,",,0, U

Blends cumd at 375 OF and 500 rpm lor 12 hours under N,

v 1CWO, EXX AC-S. RS 040, U -e- EXX AC-<;

-a -5ID5, EXX AC-S. TG..co - .... lt1J9O, EXX AC-5, TG..co -.\- ·5195, EXX AC-5, RS..co ····9··· 10190, £XX AC-S, RS..co -~ =8-"-' u g:::.....:;" -Ir ~e- .6

It! .6- 6 -. B -v 0-- -er- c E

A

c c

I

50

IJ = InRla1 Jump Region

--y. 1665 • ~0.004955x) R= 0.998S

- ·y.3344·~0.00731ax)R.0.9a14 •

- - .y. 3881 • ~0.00B12x) R. 0.9908

- •. y. 1093 • ~O.OOB34Sx) R. 0.9948

......... y. 3316 • ~O.OO7088x) R.0.9884

I

100 150 200 Time (Daya)

250

Figure 2·36, Hardening Rates of Exxon AC·5 and Blends at 140°F

34

'C C ., U • o

'" 'Ci -r:-

10'

10'

10' r

10' o

85

80

75

70 o

ENVAOOM-aged al 140 of with Atmospheric Air EXXON AC·l0 AND BLENDS

, Blends cured al 375 of and 500 rpm

lor 12 hours under N2

o o

--Y = 2824 • eA(O.005489x) R= 0.9928

- . y = 1.0B60+04 - e"{0.OO763x) R= 0,993B

- - . y = 1.2390+04 - e"{0.OO641Bx) R. 0,993

- - . y = 1.125&+04' e"{0.OO6192x) R. 0,9653

......... y. 1.2918+04 - e"{O,OO5364x) R. 0,9941 I I

50 100 150 Time (Days)

--i 3

• EXX AC-10, TK II 5/95. EXX AC-10, TG -40, TK , • 10/90, EXX AC-,O, TG -40, TK I ... 5/95. EXX AC-10. RS -40, TK ! .. 10/90, EXX AC-10, RS -40, TK i o EXX AG-10, IJ I o 5195, EXX AC-10, TG -40, IJ o , 0190, EXX AC-1 D, TG -40, U • 5195, EXX AC-10, RS -40, IJ • 10190, EXX AC-10, RS -40, W

--e- EXX AG-l0 -a . 5195, EXX AC-10, TG-40 - ... 10190, EXX AC-10, TG-40 _ •. 5195, EXX AC-10, RS-40 ····"···10190, FINA AC-10, RS-40

200 250

Figure 2·37. Hardening Rates of Exxon AC·I0 and Blends at 140 of

--y iii 89.22 + .o.02692x R= 0.9916

FlNA AC·10 AND BLENDS - Y ... 83.52 + ..(l.043OBx R .. 0.9802

o Y.,

Figure

". ".

ENVAOOM·aged at 140 'F with Atmosphertc Air

- - • y ... 82..12 + .o.03508x A 0.9817

_._--_._. Y a: 78.31 + -o.05191x R 0.9886

Blends cured at 375 'F and 00 rpm for 12 hours under N,

• FINA AC-10, TK • 5195, FINA AC-10. TG -40. TK • 10190. FINA AC-10. TG -40. TK • 5195. FINA AC-10. RS -40, TK

- ~'"!:"""'" • 10190. FINA AC-10. RS -40, TK

-<>- FlNA AC-10

50

- _v.:: ..... ~ o ..

-a ·5195. FINA AC-10. TG-40 - .. ,10190. FINA AC-10, TG-40

:; .:.:.. .. ~._.p.._.......... ~- -5195, FINA AC-10. AS -40 .... " .. ·10190. FINA AC-10. RS-40

.... ·v'-------r-----

100 150 200 Time (Days)

2·38. Change in Delta with Aging for Fina AC·I0 anb Blends

3S

"tI c

" (.) •

-., .. I!! ." II ~ U II

:a E C! ...

80

7S o

EXXON AC·5 AND BLENDS Blends cured at 375 of and 500 rpm

for 12 hours under N2

'l... V" ........... 0

'. -"9

i

Q

, ,

0 j C

C

-- y ~ 89 79 - ·O.OOBD93. h'~ 0.9433

• Y" B5 75 _ .a.02824. R~ 0.0001

. Y = 62.35 - -0.02941. R~ 0 9727 -n- _ J

£. - - ,y"a764 ·-Q,02261,R 0.9935

••..... - y .. B2.11 .. ·O.QJ589x 0.sa16

• EXX AC-5. TK

o • 5/90. EXX AC-5. TG -40. TK • 10190. EXX AC·5. TG -40. TK

-'0 '0 ...... $. A 5/95, EXX AC-S. RS -40, TK v·····~ ..... " 10190, EXXAC-S, RS-40, TK

...... ~ ... 0 -----"'-EXXAo 5 '. '. .... ..... --.::0--...,..

ENVROOM d t 140 OF -.0"""0 :-:. ~ ~~o~A;-~5~;G~O ·age a •..... ~. wfth Atmospheric Air ........ 5/95, EXX AC-5, RS -40

v · .. ·" .. ·10190, FINA AC-10, RS-40

50 100 150 200 250

Time (Days)

Figure' 2·39. Change in Delta with Aging --y = 89,69 + ·0.01115x R= 0.9986

- • Y = 82.81 + -o.0352x R= 0.9862

EXXON AC·10 AND BLENDS - - .y = 77.91 + -o.03322X R= 0.9763

90 r...-.....,....,..T.,.......-...-.,...,....,.....,.......-I'...,....,....,....~ • ..ei!ri!T.+-.I",062x R= 0.979

<>--..,· ...... -e-e_ .. 'O ....... -'Q"--'O'-""Oo---'Q ....... :: .. :: ... ~ .. ~ .. ~Y~=~77:.29 + -0.0 766x A= 0.9771 8 O-e

85 p-

80 -

75 -

70 o

ENVROOM·AGED AT 140 OF UNDER AIR .. EXX AC-10, TK

II 5195, EXX AC-10, TG -40, TK

Blends cured at 375 OF and 500 rpm : ~~A~~?R1G-46?TkK ~ for 12 hours under N2 v 10190. EXX AC-1 0, RS -40, TK "'- -e-EXXAC·10 -~~e::::::,.. -e -5I95,EXXAC-10,TG-40

.~.. -n.. ~ - ... '10190, EXX AC·10, TG-40 zr--..~ -0' . 5195. EXX AC-10, RS-40

10 ~. ""4.. .. .. " ... 1 0190, EXX AC·10, RS -40 o v- _0

·······9.""':.." - _ o ~:::::;. ...

J;>

·····.0 ... - 0_° v·..... - _ 0 '" 0-_

V··... -<>_ V .9'.... - "0

v··.. -0_ I ····9 .... '!1 ~

I

.

50 100 150 200 250 Tim" (Days)

Figure 2-40. Change in Delta with Aging for Exxon AC-10 and Blends

36

The asphalt-rubber blends were cured for 6 hours at 375°F and 1550 RPM under a nitrogen

blanket.

DEVELOPMENT OF MICRODUCTILITY TEST

FOR USE WITH ASPHALT-RUBBER BINDERS

The ductility of an asphalt-rubber binder is defmed as the distance to which it will elongate

before breaking when two ends of a specified geometry are pulled apart at a defined speed and

temperature. It is a physical test that can be used to help characterize the performance properties

of a binder. Although the significance of ductility for unaged binders is highly debatable, changes

in ductility over a binder's service life appear to correlate with overall roadway performance

(Hveem et al., 1963).

Several methods are currently being used to test the ductility of a binder. The most widely

used ductility method is the method specified in ASTM D1l3. The drawback to the current

methods is that they require large sample sizes. For example, ASTM D113 requires a 1.0 cm

thick "dogbane" briquette that is over 7.0 em long. The total sample mass is close to 10 g. This

method is particularly unsuitable when small amounts of material are available, as is the case with

laboratory aged samples or binder recovered from pavement samples. Another widely used

method is the SHRP direct tension method as specified in AASHTO TP3. The direct tension test

measures the low-temperature fracture properties of the asphalt binder. A dogbone-shaped

specimen is tested at a constant rate of elongation of 1.0 mm/min at a specified temperature until

it fractures. The stress and strain at failure are calculated using the initial cross-sectional area (A)

and effective gauge length (L,) of the specimen, the load at failure (Pr), and elongation at failure

(Ll Lr). The Texas A&M Center for Asphalt and Materials Chemistry plans to acquire a SHRP

direct tension apparatus when sufficient funds are available.

Currently, ductility is being measured with the micro-ductility instrument. This instrument

and a micro-ductility test were developed in the 1960s by Hveem et al. (1963) to measure the

ductility of a small amount of these materials. The apparatus and method developed by Hveem

et al. and a modified version of their method are described below.

37

Experimental Method (Hveem et al.)

The apparatus and procedure used for the microductility experiment was developed in

November, 1962 by California's Division of Highways. This test method (Calif. 349-A) is

designed to measure ductility of a small sample (0.05 g) of bituminous material at 77 +/- 1°F.

Test specimens are liquified on a hot plate, thoroughly stirred, and then placed inside a two part

brass mold of cylindrical geometry. This mold is allowed to cool to ambient conditions for 15

minutes. The mold forms a 0.069 inch diameter cylinder of asphalt binder and grips it at both

ends. The mold is placed into a ductility machine designed to pull the mold halves apart along

their axis. After the machine and mold have been immersed in a water bath for 10 minutes, the

mold is placed into a holder. One end of the holder is attached to a motor. The motor is then

activated and pulls the sample apart at a constant rate of 0.5 cm/min. As the test progresses, the

original cylinder of asphalt-rubber binder stretches into a very thin thread and eventually breaks.

The separation distance of the two mold halves is measured in millimeters and reported as the

ductility. In addition to being able to measure the ductility using a small sample size,

approximately 60-75 % of the specimen can be recovered at the conclusion of the test, if necessary.

The biggest limitation of the equipment used by the Calif. 349-A method is the inability

to measure the force required to generate the constant strain rate. Such force information could

be used to create a stress-strain curve for the sample. Another limitation is the small size of the

asphalt cylinder formed inside the mold. Aged binders will often fail before the molds separate

a significant distance.

Modified Experimental Method

As described above, one limitation of the original method is the small size of the asphalt

cylinder. To minimize this problem, molds with larger diameter holes were fabricated. The

largest of the hole sizes is approximately twice that of the original mold. This only increases the

sample mass required by a factor of four; so the apparatus is still capable of measuring the

ductility of a material using much less than· 1 g of sample. An additional benefit of using a larger

hole size is the ability to perform the test at lower temperatures, where ductility is generally

greatly reduced.

38

Application

The modified microductility apparatus is currently being used to study bituminous materials

without any addition of rubber. It is hoped that this test method will also yield useful information

concerning asphalt-rubber binders. Because this method accommodates samples at relatively low

temperatures (35-45°F), it may provide additional support for the low temperature benefits of

rubber-modified binders. This test will be performed on several asphalt-rubber binders and the

measurements compared to existing physical property data.

39

CHAPTER 3

EVALUATE MIXTURE CHARACTERISTICS

TIlls portion of the project is a laboratory study to evaluate the modified binders in asphalt

concrete mixtures. The two primary objectives are (1) to assess the expected performance of

mixtures that will be placed in the engineering development and demonstration phases of the

research, and (2) to define the construction procedures to be used.

EVALUATE COMPACTION CHARACTERISTICS OF MIXTURES

Compactibility of crumb rubber modified asphaltic concrete mixtures has been thought to

be a serious problem based on field experience. The crumb rubber seems to interfere with

compaction such that adequate field densities are not obtained thus contributing to early failure

of the pavement. This problem has been combatted with the development of mixture design

procedures such as that used by the Texas Department of Transportation (TxDOT). It is thought

that with a gap-graded aggregate, more void space is available to accommodate the crumb rubber

particles without interfering with field densities. Limited field experience supports the validity

of this type of design for crumb rubber mixtures.

Crumb rubber asphaltic mixtures were designed and fabricated in the laboratory according

to a mixture design procedure developed by the Texas Department of Transportation for crumb

rubber mixtures. This design procedure was developed to ensure that the load is carried by the

stone skeleton and the void space is filled with the crumb rubber modifier (CRM) and binder.

An experim~nt was designed to meet the following objectives:

• Determine the effect of CRM conc.entration on the compactibility of CRM

asphaltic concrete mixtures.

Determine the effect of CRM size and/or gradation on the compactibility

of CRM asphaltic concrete mixtures.

Determine the effect of binder curing time on the compactibility of

40

asphaltic concrete mixtures.

Evaluate the effectiveness of the mixture design procedure.

Evaluate the expected permanent deformation characteristics.

The experiment was designed to incorporate the following variables:

(l) CRM Particle Size (Gradation)

.. Top size particle passing #10 sieve

.. Top size particle passing #40 sieve

.. Top size particle passing #80 sieve

(2) Binder Curing Time (low shear blending)

III 1 hour at 350°F

III 6 hours at 350 OF

(3) CRM Concentration (percent by weight of asphalt cement)

.. 0 percent

.. 10 percent

III 18 percent (concentration typically used by DOTs)

.. 25 percent

The US Army Corps of Engineers gyratory procedure (ASTM 3387) was used to evaluate

the compaction characteristics of the materials in this subtask. This is essentially an instrumented

version of the Texas gyratory compactor and can be used to describe the progression of material

changes throughout the compaction process. The procedure is designed to address both

compactibility and performance-related issues of the mix designs, such as rutting.

All of the samples for this experiment have been tested and preliminary data analysis is

complete. A discussion of the preliminary analysis follows.

A unique feature of the Corps of Engineers gyratory test machine (GTM) is its ability to

record the density of the sample with each revolution of the compactor. Unit weight per GTM

revolution is shown in Figures 3-1, 3-2 and 3-3 for the I-hour and 6-hour binder curing times for

the -#10, -#40, and -#80 CRMs, respectively. Preliminary analysis of the data indicates very little

measured difference between the 1 and 6-hour cures. for any of the CRM sizes. There also

41

Unit Weight, pcf 150r---~----------------------------~

- '-hour Cure 140 "" + "6-hour Cure""

130 """"" L" "~~.~" "~. ~" "~" ;$i:~$:::::;;$;;:;::;$

120 .................... . . . . . . . . . . . . . . . . . . . . . . . . . .............. .

110 ......... ........... ~ ................... -." ... . . . . -.............. .

100~~~=-~~=-~~~~--~~--~~~~ o 20 40 60 80 100 120 140 160 180 200 220 240

GTM Revolution

Figure 3-1. Density Versus GTM Revolution [or CRM Asphaltic Mixtures Prepared with Binders Containing -#10 Mesh CRM

Unit Weight. pef 150r-----~--~------~~~~~-------

130 ",-. ;"~' .. ".-~."; ....•....

120--

;.' ,

100~~~~~~'~'~' ~~~~~~~~~~~ o 20 40 60 80 100 120 140 160 180 200 220 240

GTM Revolution Figure 3-2. Density Versus GTM Revolution [or CRM Asphaltic Mixtures Prepared

with Binders Containing -#40 Mesh CRM

42

Unit Weight, pef 150r--------------------------------------

I - l-hour Cure 140 ... + 6-hour Cure··

130 ~"l

, , ,

120 .. . ....................................................................... .

110 ...... .- ................................................................ ..

~

, , " , 1oo~~--~~--~--~~--~~--~--~~--~

o 20 40 60 80 100 120 140 160 180 200 220 240

GTM Revolution

Figure 3-3. Density Versus GTM Revolution for CRM Asphaltic Mixtures Prepared with Binders Containing -#80 Mesh CRM

appears to be little difference between -#10, -#40, and -#80 mesh CRMs

The gyratory compactibility index (GCI) is an indicator of the compactibility of the mix.

The closer this index approaches unity, the easier the mix is to compact. It is calculated as the

ratio of the unit mass (total mix) at 30 revolutions of the GTM to the unit mass (total mix) at 60

revolutions of the GTM. The GCl data is presented in Figures 3-4, 3-5, and 3-6.

The effect of CRM particle size on the GCl is presented in Figure 3-4 and based on these

data, all of the mixtures including the control mix (with no CRM) were very easy to compact.

The effect of CRM concentration on the GCl is shown in Figure 3-5. Surprisingly enough, the

mixture with the binder containing 25 percent CRM (by weight of the asphalt cement) was no

more difficult to compact than the asphaltic mixture with no CRM. The effect of binder curing

43

Compactibility Index

1~~~--~~~--~~~--~~~

0.8 ...

0.6 .....

0.4 .....

0.2 .....

-#10 mesh -#40 mesh -#80 mesh

CRM Particle Size

Figure 3-4. Effect of CRM Particle Size on Gyratory Compactibility Index (GCn

Compactibility Index

,~~~--~~~--~~~--~~~

0.8

0.6

O 4 .:~.::. . ,.: .

0.2 . ~" . ..~ .. ," ......... ;.

: '. '::",:=: ..

Control

CRM Concentration

Figure 3-5. Effect of CRM Concentration on Gyratory Compactibility Index (GCn

44

Compactibility Index

1~~~~---r~~--~~~~

0.8

0.6 ..... .

0.4 "" ..

0.2 """

Ed 1-hour Cure

o 6-hour Cure

- '.,' .' .. " ..... , ...

. : ~ :: .:. .

O~~~~~----~~~J-____ ~~~~~ -#10 mesh -#40 mesh -#80 mesh

CRM Particle Size

Figure 3-6. Effect of Binder Curing TIlDe on Gyratory Compactibility Index (GCl)

time on compactibility can be seen in Figure 3-6 which indicates that no difference was detected

in compactibility between I-hour and 6-hour mixes.

The gyratory stability index (GSI) is calculated as the ratio of the maximum gyratory angle

to the minimum gyratory angle. A GS! in excess of unity indicates a progressive increase in

plasticity during densification. An increase in this index indicates an excessive bitumen content

for the compaction pressure employed and foretells instability of the bituminous mixture for the

loading employed. A mix GS! in excess of unity also indicates the likelihood of the mixture to

permanently deform. The effect of CRM particle size on GS! is shown in Figure 3-7. All of

these mixtures have acceptable GSIs. The effect of CRM concentration on GS! is shown in Figure

3-8 which indicates instability in the mixture containing 25 percent CRM in the binder. The

binder curing time (Figure 3-9) does not appear to affect the GS!.

45

Gyratory Stability Index 1.2,-----------------------------------------,

0.8

0.6

0.4

0.2

O~~~~----~~~----~~~----~~~--~

Control -#10 mesh -#40 mesh -#80 mesh

CRM Particle Size

Figure 3-7. Effect of CRM Particle Size on Gyratory Stability Index (GSI)

Gyratory Stability Index 1.2r---------------------------------------~

0.8

0.6 ,:.: ..

0.4 .'::"""

0.2

O~~~~----~~~--~~~----~~~~

10% 18% 25% Control

CRM Concentration

Figure 3-8. Effect of ClRM Concentration on Gyratory Stability llndex (GSI)

46

Gyratory Stability Index 1.2r-----------------_

1

0.8

0.6

0.4

0.2

0

• 0·. ~ ...

-#10 mesh -#40 mesh

CRM Particle Size

Ed 1-hour Cure

o 6-hour Cure

. ...... ;.

-#80 mesh

Figure 3-9. Effect of Binder Curing Time on Gyratory Stability Index (GSI)

Based on the results presented herein, the GTM did not measure adverse compactibility

properties of the mixtures tested. However, the GTM measurements are made during the

compaction process (while the sample is under load). When the load was removed from the

sample, some significant changes were observed. The samples which were compacted containing

the -#10 mesh rubber swelled significantly within the first24 hours after compaction. One sample

made with the -#10 CRM even disintegrated upon removing it from the mold. Sample heights

were taken at the end of the compaction process and again 24 hours after removing them from the

mold. These data are shown in Figure 3-10. Note that the -#10 CRM mixture was significantly

taller 24 hours after extrusion. Intuitively, this characteristic would be highly undesirable in a

field mixture. It indicates that CRM mixtures may certainly compact in the field under the weight

of the roller; however, when the roller is removed the density may become unacceptable.

47

Sample Height. inches 3.51-----~ _______ ~ _ ___,

3-- ---

2.5

2

1.5

1

0.5

El Before Extrusion

o 24-hrs After

......... ~ ....

.... , ..•. --.~ .... ,.

O~~~~--~~~---L~~--~~~~ Control -#10 mesh -#40 mesh -#80 mesh

CRM Particle Size

Fagure 3-10. Sample Height Before Extrusion from the Mold and 24-Hours After Extrusion

In the past, it has been standard practice to allow CRM asphaltic concrete samples to cool

in the mold to prevent the sample from swelling; however, this practice may be deceptive. It

may be better practice to extrude the sample after molding and then measure if swelling occurs.

If swelling does occur, then adjustments to the mixture design (in particular, the aggregate

gradation) should be made.

The following are some preliminary conclusions based on this effort:

8 The TxDOT mixture design procedure used in this study, in general seems

to be acceptable for the design of CRM asphaltic mixtures.

CRM mixtures designed _ according to the TxDOT mixture designed

procedure appear to be resistant to permanent deformation, with the

48

exception of the mixture which contained a large concentration of CRM

(25%).

The CRM binder curing times evaluated in this study did not affect

compactibility or permanent deformation characteristics of the asphaltic

concrete mixtures.

CRM particle size is the main variable evaluated in this study which affects

its compactibility, based on measurements of sample heights taken after

extrusion from the mold. CRM particle size of -#10 or greater is of

greatest concern. While it may be possible to design a mix to accommodate

CRM of this size, the mixture design in this study was not adequate.

EVALUATE DEFORMATION AND FAILURE OF COMPACTED MIXTURFS

In the compaction study, a methodology for designing good mixtures was verified. In

Subtask 2.3, the methodology is being applied to design and compact mixtures having different

asphalts and binder preparation methods. These materials will be aged and tested for deformation

and failure using three test methods: (1) "nondestructive" sinusoidal frequency sweeps (fully

reversed tension-compression), (2) creep and recovery, and (3) tensile strength to failure. A

summary of the experiment plan is shown below.

Aging CRMBinder Time

1 2 3 4 5 6 7 8 9 10 11 12

0

1

2

3

49

Preparation of binder samples to be tested for this subtask is complete. Compacted

samples will be prepared using six different asphalt cements combined with 18 % -#80 CRM cured

under two different conditions for a total of 12 binders. The six asphalt cements to be used in the

experiment are as follows:

Diamond Shamrock Resin,

Fina Resin,

Fina AC-lO,

Fina AC-5,

Exxon AC-5,

Exxon AC-lO.

Two curing conditions were used for preparation of the binders:

375°F, 1550 rpm, 6 hours, and

350°F, 500 rpm, 1 hour.

All of these twelve binders have been prepared. Aggregate has also been prepared for preparation

of the compacted samples and compaction of samples is ongoing.

50

CHAPTER 4

ADHESION TEST PROPERTIES

The strength of an asphalt-aggregate composite mix and its performance under varying

loads and environmental conditions are key factors in determining pavement lifetimes. These

factors strongly depend on the cohesive properties of the asphalt constituent and the adhesive

properties at the asphalt-aggregate interface (Labib, 1992).

The work of cohesion is the work required to create two interfaces from one phase (see

Figure 4-1):

(4.1)

where aGo is the Gibbs free energy of cohesion, and Y I is the surface energy of phase 1. The

work of adhesion is what is needed to create two interfaces from two phases in contact (see Figure

4-2):

(4.2)

where aG'12 is the Gibbs free energy of adhesion and Y 12 is the interfacial surface energy of phase

1 and phase 2.

The cohesive and adhesive bonding interactions in asphalt-aggregate systems arise mainly

from two effects: (1) the Lifshitz-van der Waals interactions of electron shells df neighboring

molecules and (2) the acid-base interactions between constituent molecules (Good and van Oss,

1992). The acid-base interactions are generally dominant for asphalt-aggregate composites and

are particularly critical in establishing strong adhesive bonds as well as bonds that are resistant to

water enhanced stripping (Labib 1992). The acid-base interaction term is further partitioned into

a Lewis acid parameter and Lewis base parameter. Thus, three parameters must be determined

to calculate the surface energy of the material: Lifshitz-van der Waals, Lewis acid, and Lewis

base. The surface energies of the materials, the asphalt and aggregate, are used to calculate the

work of cohesion and the work of adhesion. It should be noted that the Lifshitz-van der Waals

force is present in all molecules, but acid-base interaction are not. In fact, the acid-base

interactions will be the key in determining the compatibility of asphalts and aggregates.

51

1

Vacuum

1

1

Figure 4-1. Work of Cohesion

1

1

Vacuum

2

2

Figure 4-2. Work of Adhesion

52

The usefulness in being able to calculate the work of cohesion and adhesion by measuring

the surface energies of asphalts and aggregates are threefold: (I) The mechanical work required

to crack an asphalt-aggregate interface can be predicted. This theoretical work of adhesion would

correspond to a fracture test measured below the brittle-ductile transition· temperature. (2)

Numerous crack propagation models exist; but, these models require difficult experiments to

determine the parameters. It can be shown that these parameters are functions of the surface

energies of the materials. By measuring the surface energies of asphalts and aggregates, these

parameters can be calculated. (3) Asphalt-aggregate systems can be evaluated for the propensity

to be water susceptible. Suitable asphalts may be found for the so-called" stripping aggregates."

The focus of this portion of the project is establishing the framework for predicting adhesion and

cohesion in asphalt-aggregate systems. The main goals of this investigation are: (1) to develop

test methods that predict adhesion and cohesion in asphalt/asphalt-rubber and aggregate systems,

(2) to develop test methods predicting adhesion and cohesion in asphalt/asphalt-rubber and

aggregate systems in a water environment, and (3) to use the test methods to evaluate

asphalt/asphalt-rubber and aggregate mixes.

ADHESION TESTS

Wilhelmy Plate Method

The Wilhelmy plate method (Wilhelmy, 1863) is an established technique for measuring

contact angles of liquid/solid systems and is being used in this study. The contact angle is

determined by measuring the change in force during immersion and emersion cycles (see Figure

4-3):

~F = py cose (4.3)

where ~F is the change in force; p is the perimeter of the plane; y is the surface tension of the

liquid; and e is the contact angle between the solid and liquid measured through the liquid.

. The apparatus consists of three main components (see Figure 4-4): the Cahn C2000

balance for measuring the force; the moveable platform to advance and recede the liquid;

53

(al before plate contacts with liquid

Liquid

(b) plate just contacts the liquid-air surface

Liquid

(c) plate is partially immersed in the liquid

. " Liquid

Figure 4-3. Dynamic Wilhelmy Plate Method Force Balance

54

glass plate

Cahn C2000 balance

step motor

shielding case

computer data acquisition

& control

lFigwre 4-4. Wilhelmy Plate Apparatus

55

and a computer for data acquisition and control. Glass plates are coated with asphalt to produce

a smooth solid surface. The contact angle of four fluids (water, glycerol, ethylene glycol, and

formamide) are measured against the asphalt coated glass plate. From the advancing and receding

contact angle measurements of two fluids, the three parameters of the surface energy can be

determined. The two remaining fluids are used to verify the results.

An inherent problem with the Wilhelmy plate technique is contact angle hysteresis.

Hysteresis is the difference between the advailcing contact angle and the receding contact angle.

It is believed that for heterogeneous materials that the hysteresis effect can be explained. While

the liquid "sticks" on the high energy acid-base regions and only wets the Lifshitz-van der Waals

regions. Therefore, the acid-base interactions are negligible while advancing. While receding,

the liquid preferentially wets the high energy regio}ls; the receding contact angles are a measure

of the total surface energy.

Figure 4-5 is an example of a typical set of experimental results. The lower straight-line

region corresponds to the advancing angle while the upper straight-line corresponds to the receding

angle. For each experiment, a total of 5 advancing and receding cycles are measured. As can be

seen from Figure 4-5, the reproducibility for a single plate is quite good.

A total of 19 asphalts have been characterized using the Wilhelmy plate method (see Table

4-1). Figure 4-6 is a graphical representation of the two surface energy components: yLW is the

Lifshitz-van der Waals force while yAB is the acid-base interactions. All of the asphalts exhibit

a wide range of values.

Gas Adsorption

The aggregates pose a more difficult problem than the asphalts. Since a smooth surface

cannot be made from the aggregates, gas adsorption must be utilized (see Figure 4-7). A total of

four gases are needed for this process; three to characterize each aggregate with the fourth being

used to check the results. The gases used are hexane, water, methyl propyl ketone, and

chloroform.

Six aggregates have been characterized with one being separated into 7 size gradations

56

Asphalt Coated Plate AAG-1 in Glycerol

350

300

-I/) 250 CI) I: >-'C 200 ...... CI) u 150 ... 0 u.

100

50

0 -0.4 -0.2 0 0.2 0.4 0.6 O.B

Depth (em)

Figure 4-5. Example Experimental Results

60 -- 1 8 (\I < 50 E -.., E 40 -->-i:7)

30 "-til I: W

til 20 u m - 10 ... ::::I rn

0

Figure 4·6. Surface Energy of Various Asphalts

57

Pressure Gauge

High

Hand Pump

Nitrogen In!d.

Go to Fume Hood forRc1easc

Go to Fume Hood

Safety Disc

J" ransducer

1tfj....,r-tf;I-Pressure Release

Figure 4-7. Gas Adsorption Experimental Apparatus

58

988 Funoe!

(see Table 4-2). Figure 4-8 represents the two components of the surface energy. Both

components are much larger for the aggregates than for the asphalts.

Adhesion and Cohesion

From the measured surface energies, the work of cohesion and the work of adhesion can

be calculated. The work of cohesion for various asphalts in a vacuum and in water can be seen

in Figure 4-9. For less polar asphalts (having small acid-base parameters), water increases the

work of cohesion.

If the work of adhesion is greater than the work of cohesion, fracture should occur in the

asphalt. If the work of the adhesion is less than the work of cohesion, fracture should occur at

the asphalt-aggregate interface. Two aggregates were analyzed with various asphalts in a vacuum.

According to Figures 4-10 and 4-11, fracture should occur in the asphalt binder. Figure 4-12 is

a comparison of the two aggregates in a vacuum. Both JG11a and JG21 have similar works of

adhesion.

WATER SUSCEPTIBILITY TESTS

According to Figures 4-13 and 4-14, water will decrease the work of adhesion. For

aggregate JG 11a, some asphalts have the potential to strip (see Figure 4-15) since the work of

cohesion is greater than the work of adhesion. For aggregate IG21, virtually all the asphalts have

the potential to strip (see Figure 4-16). In Figure 4-17, the aggregates are compared by the work

of adhesion in water. The results suggest that IGlla is better aggregate than JG21 for all asphalts.

Summary of Adhesion Tests

Using the work of adhesion and the work of cohesion, the asphalt-aggregate systems can

be ranked according to their potential to water strip (see Table 4-3). These are presented from

highest to lowest with the acceptable systems having a positive difference and the unacceptable

systems having' a negative difference.

59

Table 4-1. Characterized Asphalts

Code Description AAB-J SHRP WYoming Sour AC-lO AAD-J SHRP California Coastal AR 5000 AADN AAD-J + 6% PE. Novophalt AAG-J SHRP California Valley AR 4000 AAM-l West Texas Intermediate AC-20 EX 10 Exxon AC-lO

hXlOa EXIO + 5% CaO EX5 Exxon AC-5 EX5a I EX5 + 5% Rouse -40 Mesh F110 . FinaAC-lO JA: 1 RTFO A edJG3l

II-J..;;;;;G-'~j li-nF.Ku~wT.~O/lOi JUjL I Saudi /Iv, 100 [Esso) JU33 Venezuela 80! 100 (Nvnas)

JC 33a J(i33 Jlijjb I J( .33 BUDble Al!;ed tor 24{J hours JU34 I KuWaIt 45/60

JG34a • JG34~ I-~ JUjrr-:> ""'"V;T.:en=e=Ziielii"HUlluu"WSliiii=)-----I

Table 4-2_ Characterized Aggregates

Code "i'5eSC'ritition JGlla Meuse River Sand 500-1000 !1111 JUUb Meuse River Sand 250-500 !1111 Julle Meuse River Sand 125-250 !1111 JGlld Meuse River Sand 125-250 !1111 repeated JGIle Meuse River Sand 63-125!1111 JGllf Meuse River Sand <63 !1111 JGllg Meuse River Sand <63 !1111 crushed JU12 Lake Ijsselmeer 125-25O!1II1 JGl3 Glansanda Crushed Granite 125-250!1ll1 JG21 Limestone Filler from Winterswiik JG22 WlgI3S 40K from WmterswJ.jk

(Limestone dust. fly ash. and -hydrate) JG23 Wigro 6OKfrom WmtersWljk

(Limestone dust and hydrate)

60

250 --N < E 200 -..., E -->- 150 Cl .. II) c 100 I!J

II) U III

50 -.. ::3 fI)

0 lIS U - Cl C\I t':l C\I t':l .,... .... .... .,... .,... .... .,... .,... .... .... .,... C\I C\I C\I (!) (!) (!) (!) (!) (!) (!) (!) (!) ..., ..., ..., ..., ..., ..., ..., ..., ...,

Material

Figure 4·8. Surface Energy of Various Aggregates

..... 150 1"""T..,....,....,...-rI"'f"T"I""'T..,....,....,...-r""""'I""'T""""'T"""!"" '" <

~ E ..... c 100 o iii II) .c o CJ

50

o

III Work in Vacuum Ea Cohesive Work in Water

Figure 4·9. Work of Cohesion of Various Asphalts

61

200 -N <

.E 150 ..,

.s t: 100 o 3:

50

III JG11a Adhesive Work in Vacuum lSl Cohesive Work in Vacuum

Figure 4·10. Work of Adhesion and Cohesion of Various Asphalts with Aggregate . JGlla in Vacuum

250

200 .... N < E

150 -.., E -.lit 100 .. 0 3:-

50

0

Figure 4·11. Work of Adhesion and Cohesion of Various Asphalts with Aggregate JG21 in Vacuum

62

c: 0 III Q) .c: 'C 0:( -0 .liI: .. 0 :t

150

100

50

0

~ JG 11 a Adhesive Work in Vacuum ~ JG21 Adhesive Work in Vacuum

Figure 4·12. Work of Adhesion for Various Asphalts and Aggregates in Vacuum

.-. 250 """"'''''-''T"'"'I--r'"''T'''''T''''"T''''-''T"'"'I''''''''''''T'''''"'''''''''''''''''''''''''''''''' C'i < E :::; 200 E .... c:

150 0 ;;; Q) .c: 'C 100 0:(

'0 .liI: 50 .. 0

':t ; 0

~ JG11a Adhesive Work in Vacuum ~ JG11a Adhe 've Work in Water

Figure 4·13. Work of Adhesion of Various Asphalts with Aggregate JGlla

63

c 0 Ui III .c 'C oCt -0

.lI: ... 0 ::t

150

100

50

0

~ JG21 Adhesive Work in Vacuum cw JG21 Adhesive Work in Water

Figure 4·14. Work of Adhesion of Various Asphalts with Aggregate JGll

..... N

~ 100 "")

E --.lI: .. ~ 50

II JG11 a Adhesive Work in Water lSI Cohesive Work in Water

Figure 4-15. Work of Adhesion and Cohesion of Various Asphalts with Aggregate JGna in Water

64

1 5 0 ,......r-r,~.,.... ',.....,-,...,"...,..,.,~.,...,.. I'-""'II~"""'" ,.,...,..,......",~,~ ......... ,"""" ,'-"'"

-('oj

< 100 E -"')

E --~ .... ~ 50

III JG21 Adhesive Work in Water I:::sI Cohesive Work in Water

T

T

T

-

Figure 4-16_ Work of Adhesion and Cohesion of Various Asphalts with Aggregate JG21 in Water

--'" 140 <

~ 120 ..... c 100 o iii II) .s:: 'D <I:

80

60

'0 40 ~ .. o 20 ~

til JG11a Adhesive Work in Water l,Sl JG21 Adhesive Work in Water

Figure 4-17. Work of Adhesion for Various Asphalts and Aggregates in Water

65

· Table 4-3. Ranking of Asphalt Aggregate Systems

Acre table JGlla--EX5a JGlla--EX5 JG21----EX5a JGlla--EXlOa JGlla-AAM-l JGlla--JG33a JG21-EX5 JGlla-EXlO

Unacce table JGlla---JG35 JGlla---JG33 JG2l---EXlOa JG21-AAM-l JGlla-AAG-l JGlla-AADN JG21--JG33a JGlla---JG33b JG21---EXlO JG21--JG35 JG21----JG33 JGlla-JG31 JGlla-FIlO JGlla-AAB-l JG21--JG33b JG21-AAG-l JG21-AADN JG lla--JG32 JGlla-AAD-l JGlla-JA31 JGlla-JG34 JG21-AAB-l JG21---JG31 JG21-AAD-l JGlla-JG34a JG21-FIIO JG21-JA31 JG21--JG32 JG21---JG34 JG21-JG34a

66

The goals for future adhesion work are as follows:

-determine if predictions of water stripping are true

-compare calculated work of cohesion with direct tension measurements for confirmation

of strength predictions

-characterize asphalt-aggregate systems of known water strippers

-determine the effects of rubber in more asphalts on adhesion and cohesion

-determine the effects of other asphalt additives (LDPE, lime, etc.) to adhesion and

cohesion

67

CHAPTER 5

ECONOMIC SUMMARY

This chapter provides economic analyses for using recycled tire rubber in an asphalt

binder in original construction. It does not consider the use of coarse rubber in the "dry"

process. With this application, we envision the use of a supercritical refinery process to produce

an optimal asphalt material for blending with the crumb rubber and this added cost is included

in the analysis.

Two economic evaluations are considered in this chapter. The first addresses the incentive

for the refiner (as producer) to construct a ROSE unit for producing the additive material

necessary to produce the optimal asphalt binder. The second type of evaluation addresses the

incentive for departments of transportation (as users) to construct pavements using crumb-rubber

modified asphalt (CRMA) binder. This latter situation is considered in three economic scenarios

based on three different service lifetimes of the CRMA pavement (15, 18, and 21 years).

From the point of view of the departments of transportation, and with the government

mandate for using tire rubber in pavements now gone, the only argument for using crumb rubber

is that pavements would have a lower life-cycle cost. Since the CRMA pavement will initially

be more costly, this requires that it also last sufficiently long and with sufficiently reduced

maintenance to justify the greater initial expense. As a result, this would also use less material

(reduced energy cost) and produce less waste than the conventional pavement.

At a crumb rubber cost of $O.14/lbm and a blending/curing processing cost of $25/ton

of binder, a pavement life extension of approximately 6 years (beyond a conventional pavement

life of 12 years) provides an internal rate of return of 29%. While this required life extension

is significant, based upon the technical results of the earlier chapters on CRMA aging and

low-temperature property improvements, we believe that such improvement ultimately will be

achieved.

68

THE ROSE REFINING PROCESS

This analysis is for a single residual oil supercritical extraction (ROSE) refinery process

with a capacity of handling 30,000 bbVday of feed to produce 10,000 bbl/day of aromatic material

for blending with conventional asphalt. The cost for such a plant is summarized in Table 5-1

and is based upon data taken from Hydrocarbon Processing (1992) and Peters and Timmerhaus

(1991). The data in Table 5-1 show that the annualized cost of producing the aromatic material

(AM) is $3.40/bbl of AM.

Table 5-1. Estimated Cost to Produce Aromatic Material Using a Supercritical Fractiona­tion Unit.

Basis: 30,000 BbVday of feed (10,000 Bbl/day of Aromatic Material)

Item

Installed Cost Utilities· ($/yr) Labor & supervision ($/yr) Maintenance & supplies ($/yr) Other ($/yr) Depreciation (lQ.yr) Total Annual Operating Cost CostIBbl of feed CostIBbl of recycling agent

• 105 BtulBbl of feed, 330 operating days/yr, $3.51106 Btu

Cost

$30 xl06 3.5x106

1.5 x 106

1.8x106

1.5x106

3.0xl06 ll.3x 106

$1.14 $3.40

Using the minIbers in Table 5-1 and an assumed sales price for the aromatic blending

material of $6.25/bbl of AM over and above the feed cost/bbl, an economic analysis using the

OIT spreadsheet is obtained (Appendix B).

As a result of these calculations, it is seen that a sales price of $6.25/bbl above the feed

cost is sufficient to provide an internal rate of return (lRR) of 26% for the ROSE process, with

a discounted payback period of 4.4 years. This is an aromatic material cost of approximately

$ 135/ton. This cost of the supercritically-refined material is passed on to the next sections for

calculating the cost of the CRM asphalt pavement.

69

CRUMB RUBBER MODIFIED ASPHALT PAVEMENT

This section compares the relative cost and benefit of a CRM asphalt pavement compared

10 a conventional asphalt binder pavement. It is assumed that a new conventional overlay is

placed which is 4 inches thick, 30 feet wide (2 lanes), contains 5 wt% binder and 95 wt%

aggregate and has a density approximately twice that of water. With these assumptions, there

are 3,270 tons of pavement per mile:

(30 ft)(O. 333 ft)(5280 ft) I (2)(62) Ibm I ton of mix _ 3,270 tons of pavement mi ft3 2000 Ibm - mi

At 5% binder in the mix, this is 164 tons of asphalt binder/mile. Assuming that the CRMA

pavement contains approximately the same weight of pavement, per mile, then there would be

196 tons of CRMA binder/mile.

Capital Cost

The in-place cost of a conventional pavement is approximately $30/lon of pavement (0.95

t of aggregate at $5/t of aggregate, 0.05 t of binder at $100/t of binder, and $20/1 of mix for

placement) which is approximately $98,100/mile of pavement.

The in-place cost of a CRMA pavement, assuming the same costs except $103.5/t of

CRMA binder (90% asphalt at $100/lon and 10% aromatic material at $135/ton) plus a processing

cost of $25/ton of binder for blending and curing, plus 6% binder instead of 5% gives a CRMA

pavement cost of approximately $12,200/t of pavement more than the conventional pavement

or $1l0,300/mile of pavement. Of this increase, $8,400 is due to the cost of the rubber and

blending and curing process, $3,100 is due to the larger binder content (6% versus 5%), and

$690/t is required for the superior asphalt.

Maintenance

For both the conventional and CRMA pavement, a baseline maintenance cost was ap­

proximated as one-fourth of the original capital cost of the conventional pavement (including

construction) distributed over the life of the pavement. For the conventional pavement (having an

average service life of 12 years), this is $2,040/mile/year. For the CRMA pavement, assuming

70

a service life of 15 years for example, this is $1,635/mile/year, assuming that maintenance

procedures will be less frequent (occuring over 15 years) but technically no different than for

the conventional pavement. This level of maintenance cost for the conventional binder is sup­

poned by the actual amount, approximately $1,OOO/lane-mile/year (for conventional pavement),

budgeted for pavement maintenance by Texas DOT.

Several eRMA pavement perfonnance levels were considered in the analysis. Each level

represented a different pavement life (15, IS, and 21 years) and was compared to an average life

of 12 years for a conventional pavement. To compare the two pavements at each perfonnance

level over the same time period, the cost to replace the conventional pavement was prorated

over its expected life (12 years), multiplied by the additional number of years needed to meet

the projected life of the eRMA pavement, and then this total additional expense was distributed

over the entire perfonnance period as additional maintenance cost. For example, with the COS! of

the conventional pavement at $9S,I00/mile, the added "maintenance" cost to bring the 12 year

conventional pavement to 15 years would be

$98,100 1 2 yr _ 12 mi yr 15 yr

$1,090 miyr

and this is added to the usual baseline maintenance cost in the preceeding paragraph to obtain

the total. No such adjustment is required for the eRMA pavement since its assumed life is 15

years.

Energy Use

The energy use entered for each pavement is the amount of binder used, convened to

energy equivalents. For the conventional material, this is

163.5 tons of asphalt 12000 Ibm 120,000 Btu 1 = 545 x 106 Btu mile ton Ibm 12 yr -m-'-l--yr-

For the CRMA binder, this amount is proportionately less because of the extended lifetime of

the pavement, but increased by the higher binder content of the pavement. Accordingly, for the

eRMA binder the pro-rated energy use is

196 tons of asphalt 12000 Ibm 120,000 Btu 1 = 523 x 106_B....,.tu_ mile ton Ibm 15 yr mi yr

71

Waste

The amount of waste for the conventional pavement is simply 3,270 IOns/mile over 12

years or 273 tons/mi/yr. For the CRMA pavement, this amount is reduced proponionately due

to the extended lifetime of the pavement.

Table 5-2 summarizes the economic results obtained for three hypothetical lifetimes of

the CRMA pavement: 15 years, 18 years, and 21 years.

Table 5·2. CRMA Pavement versus Conventional Asphalt Pavement Comparison

CRMA Payback Pvmnt Cap Cost Maint Cost Energy Use Waste IRR Period Life ($103/mi) ($/mi/yr) (106 Btu/mi/yr) (tons/mi/yr) (%) (yr)

(years) Cony CRMA Cony CRMA Cony CRMA Conv CRMA

15 98 110 3.678 1.635 545 523 273 218 14.9 9.3 18 98 110 4.770 1,362 545 436 273 182 29.0 4.4 24 98 110 6,130 1,168 545 374 273 137 38.0 3.2

•

72

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76

AASHTO

AC M1 AR ASTM ATR BBR CA CRM CRMA DOE-OIT DOT DS ENV ES FTIR GCl GPC GSl GTM HPLC D IRR MP P POV PTFE RA ROSE RPM RS S SA SC SHRP TG THF TK TxDOT WC

ABBREVIA TIONS

American Association of State Highway and Transportation Officials

asphaltene content aromatic material asphalt rubber American Society for Testing and Materials attenuated total reflectance bending beam rheomater carbonyl area crumb rubber modifier crumb-rubber modified asphalt Department of Energy Office ofIndustrial Technologies Department of Transportation Diamond Shamrock environmental exposed surface Fourier transform infrared spectroscopy gyratory compactibility index gel permeation chromatography gyratory stability index gyratory test machine high performance liquid chromatography initial jump internal rate of return metering pump pressure or pressure gauge pressure oxygen vessel poly tetrafluoroethylene recycling agent residual oil supercritical extraction revolutions per minute Rouse separators superior asphalt supercritical Strategic Highways Research Program Tire Gator tetrahydrofuran tank Texas Department of Transportation water cooled condenser

77

NOTATION

cross-sectional area effective gauge length elongation at failure Lifshitz-van der Waal's component of surface energy load at failure low frequency limiting viscosity

78

APPENDIX A

EXPERIMENTAL METHODS

SUPERCRITICAL FRACTIONATION

A brief description of the supercritical fractionation process, operating conditions, and

apparatus modifications follow. The following description is taken primarily from the TxDOT

Study 1249 (Davison et al, 1992) report with appropriate modifications. The unit operates at a

constant pressure above the critical pressure of the solvent. The SC fractionation unit separates

heavy petroleum products into up to four fractions according to solubility in SC solvents .. The

temperatures of the separators determine the density of the solvent and, consequently, the solvent

power in each vessel. Components of the feed precipitate when no longer soluble in the solvent.

The lightest, most-soluble materials are removed by decompression during solvent recovery.

Figures A-I and A-2 illustrate schematically the SC unit. The solvent is pumped to the

operating pressure in S 1-S3 by MPl. Several hours are required to bring the temperatures to the

desired steady-state values. The steady-state operating temperature in S4 determines the steady

state pressure for S4. Once steady-state conditions are achieved, MP2 is activated, introducing

feed material into the circulating solvent stream. The temperature in each separator determines

the solubility in the SC solvent. The insoluble material is transferred from the separator to its

.corresponding collector periodically to avoid potential plugging problems while the soluble

material travels to the next separator. Finally, the overhead mixture from S3 passes through the

control valve, where the pressure is reduced to significantly subcritical value. At these gaseous

conditions, none of the asphaltic material is soluble and complete separation of the solvent is

achieved. The solvent then passes overhead, is condensed in WCI and flows back into the solvent

reservoir. For this DOE effort, n-pentane is the solvent used for supercritical fractionation.

The four asphalts fractionated during the first year of this DOE effort were fractionated

in two passes through the unit. The lightest fraction from the first pass was fed through the unit

79

00 o

Al

','

Filler

P6

C3 C4

C2

Figure A·1. Supercrltlcal Unit Process Diagram WC2

so

C1-C4

III

C?

Solvent Tank

Collectors

In-line Filter/mixer

Control Valve

Tubing Wall Temperature Thennocouple

Pressure Controller

Heating Tape Heater

Dual Purpose Heater/Cooier

S1-S4 Separators

A1 Asphalt Tank

Valve

<y Thennocouple

~ Temperature Monitor and Controller

Pressure Gauge

Metering Pump

WC1

~ Water Cooled Condenser

Figure A·2. Legend for Supercritical Extraction Unit Diagram'

81

a second time yielding eight fractions that may be analyzed. The lightest fraction from the second

pass is designated as fraction F I and the heaviest fraction from the first pass is designated as

fraction F8 (fraction F5 is the feed material for the second pass through the unit).

PRESSURE OXYGEN VESSEL (POV)

The original unit is described by Lau (1992) and Davison et al. (1992). In order to

improve on aging simulation capacity, four additional units were constructed and a central control

panel was installed as shown in Figure A-3. Later, to eliminate temperature gradient problems

with the initial design, the vessels were placed in glycol/water baths.

Figure A-4 shows a schematic of one of the pav s. The vessels are located behind a steel

wall in an explosion proof hood. Each vessel is contained in an aluminum barrel filled to the

bottom of the top flange with a mixture of triethylene glycol and water. The vessel is monitored

and controlled from a panel outside the explosion proof hood. The control panel houses a

compound pressure gauge to monitor the pressure, a variable transformer to control the amount

of electrical power to the heating elements in the water/triethylene glycol bath, a temperature

controller which controls the temperature of the bath, and a recorder to monitor the temperature

within the pav. A stirrer is employed in the bath to insure that the temperature distribution in

the bath is uniform. A vacuum pump is used to evacuate the vessels before charging with oxygen

or to remove oxygen depleted air once per day. Three valves per vessel, as labeled in Figure A-I,

are used for venting to atmospheric pressure, evacuating to low pressure to remove the gas inside

the vessel, and charging with oxygen. The oxygen feed valve isobites the pays from the oxygen

cylinder when closed.

Asphalt samples are prepared in aluminum trays. The dimensions of the tray are 7.0 cm

(2.75 in) by' 3.5 cm (1.38 in). Typical ftlm thicknesses of less that 1 mm (0.039 in) are used to

minimize potential diffusion problems at low pressure; however, diffusion studies may be

performed with thicker films. After preparing the asphalt samples, loading the sample rack, and

allowing the temperature in the pav to reach equilibrium, the operator places the rack inside the

pav and bolts the cover flange to the top. The vent valves, oxygen feed valves, and vacuum

82

VACUUM

POVS POV4

PG

5

POV 3 POV2 POV 1

IiOI ~

OXYGEN FEED

VACUUM VACUUM VACUUM VACUUM VACUUM OXYGEN ~....:!5 ___ -=4,-__ ..::3!:::-_--.;2=--__ -!1 ______ -l CYLINDER

I ~ VALVES ~ VARIAC

[l£) TEMPERATURE Q COMPOUND CONTROLLER V PRESSURE

GAUGE

r-::-1 TEMPERATURE ~ DISPLAY

r-;ii"""l10 CHANNEL ~ SWITCHING BOX

Figure A·3. Pressure Oxygen Vessel Control Panel

.... -------TEMPERATUR~

RECORDER

/---r:;:Uij TEMPERATURE!

POWER SUPPLY

-' w rn rn w > Cl Z

~ VACUUM

PUMP

L~"'::==:I~· POV BEHIND SHIELD

VENT

OXYGEN FEED

VALVE • I _ C.QNTROI..I

PANEL

OXYGEN CYLINDER L-._J

Figure A·4. Pressure Oxygen Vessel and Control Panel

83

valves are closed. A vacuum pump evacuates the air in the vessel to a pressure of 0.03 atm

absolute. The vessels are slowly pressurized to the desired level by manipulating the oxygen

cylinder regulator and oxygen feed valves for pure oxygen aging, or by slowly opening the

atmospheric venting valve for aging with air (note 0.2 atm oxygen is equivalent to atmospheric

air aging). Once the desired oxygen pressure is reached, the cylinder, regulators, and feed valves

are closed.

During the experiment, samples are periodically removed. To obtain samples, the pressure

in the vessel is decreased by slowly venting off the oxygen to the atmosphere until the pressure

gauge reads zero. The operator removes the top insulation, unbolts the cover flange, and collects

the samples. Samples to be aged further are loaded back into the vessel, and the process is

repeated. The aged samples are saved for chemical and physical analysis.

CORBETT ANALYSIS

A description of the traditional Corbett (1969) analysis can be found in the standard

method ASTM 04124. Corbett analysis separates the components of an asphalt according to

polarity. Some modifications of the Corbett procedure were implemented to reduce sample size

and increase efficiency as suggested by Thenoux et al. (1988).

MIXING APPARATUS

To produce the asphalt-rubber binders, asphalts and rubbers were 'cured' or mixed at high

temperatures (> 177"C (350"F). Curing, for the purpose of this paper, is defined as an increase

in viscosity without oxidation, with oxidation being measured by the carbonyl peak area of the

infrared spectrum. The curing process, as carried out in this laboratory, involved mixing at high

temperatures with a 5.1 cm (2") diameter blade driven at variable speeds, 500-1550 rpm by a

variable speed motor. The blends were cured in either 1 quart or I gallon paint can, depending

on sample size, under a nitrogen blanket to prevent the binder from oxidizing.

84

BENDING BEAM RHEOMETER

Low-temperature properties of the asphalt-rubber binder, were evaluated using a bending

beam rheometer (BBR). Anderson et al. (1990) concluded that the BBR is the best instrument for

measuring low-temperature properties of binders. Furthermore, both Set) and the m-value, the

properties obtained by utilizing the BBR, have been correlated with the low-temperature thermal

cracking of binders (Bahia et aL 1992). All bending beam results were obtained at a beam testing

temperature of -15DC (5"F). The beam specimens were produced and the bending beam rheometer

was utilized as specified in AASHTO Designation TPI.

DYNAMIC SHEAR RHEOMETER

The intermediate-temperature rheological properties were tested with a Carri-Med CSL-500

dynamic shear rheometer configured in the parallel plate geometry. This instrument may be

operated in either a constant stress-mode (its natural mode) or a constant-strain mode over a

temperature range from O"C (32"F) to 9O"C (l94"F). This instrument was operated in the constant­

stress oscillation mode for analysis of neat asphalt samples but the constant-strain mode was

necessary for analyses of asphalt-rubber samples.

The behavior of asphalt samples is non-Newtonian at intermediate oscillatory frequencies.

However, by utilizing the constant-stress mode, a limiting complex viscosity, TJ:, can usually be

obtained at low frequencies. For highly aged samples the low frequencies are obtained by

utilizing temperatures greater than the reference temperature and the time-temperature

superposition principle (Ferry 1985). For asphalt-rubber samples, however, at low frequencies,

a limiting complex viscosity can not be obtained. To complicate matters further, the strains

induced in the asphalt-rubber binders at low frequencies are quite large and may cause partial

destruction of the bonds' formed between the asphalt and rubber during the curing process.

Therefore, it is necessary to operate the rheometer in the constant-strain mode for asphalt-rubber

samples.

To analyze the asphalt-rubber samples in this study it was necessary to determine the strain

85

level which corresponds to the linear viscoelastic region. Theorectically, the linear viscoelastic

region exists in the strain level range from 0% to some maximum percent strain level. However,

a rheometer cannot accurately measure linear behavior at and slightly above the 0% strain level,

thus narrowing the range of the linear viscoselastic region. In reality the measureable linear

viscoelastic region exists from a stain level range of slightly above 0%, a minimum strain level,

to a maximum percent strain level. This range was determined by specifying several different

strains and observing the strain response wave. Linear viscoelastic behavior is encountered when

the strain response to sinusoidal stress input is also sinusoidal. The strain level for measurement

was chosen to be the minimum strain level at which measureable linear viscoelastic behavior

occurred. This minimum strain level was found to be highly sample dependent and ranged from

approximately 0.5% to 200%, depending upon the temperature.

An additional complication to the measurement of asphalt-rubber properties is the presence

of the rubber particles. As a result, it was necessary to determine the gap width for the parallel

plate geometry. This gap width was found to be strictly a function of the rubber particle size and

rubber content. The gap width for a given rubber size and content was determined by measuring

the rheological properties of a given asphalt-rubber at multiple gap settings. To insure the

elimination of the 'gap effect', the gap width was chosen such that the rheological properties taken

at as wide or wider gap widths, were independent of the gap width.

BROOKFIELD ROTATIONAL VISCOMETER

A Brookfield rotational viscometer Model RVF 7 was used to obtain the high-temperature

(> 121"C) (250"F) viscosities of the asphalt-rubber binders. Torque is applied to spindle placed

in the binder sample which is contained in a thermostatically controlled beaker. The relative

resistance to rotation is measured for a given rotational speed. The relative resistance, the spindle

size, an the rotational speed are then used to calculate the viscosity, ".

86

GEL PERMEATION CHROMATOGRAPHY (GPC)

GPC analyses were performed using a Waters 712 sample processor and a Waters 600E

multisolvent delivery system. Helium-sparged HPLC grade tetrahydrofuran (THF) at a flow rate

of 1 mLimin was used as the carrier solvent to efficiently separate the asphalt-rubber binders.

Three columns with pore sizes of 1000A, 100A, and 50A were connected in series. The lO00A

and lOOA columns are 30.5 cm (l foot) in length and are packed with ultrastyragel particles. The

50A column is 61.0 cm (2 feet) in length and is packed with PLgel particles. A Waters 410

Differential Refractometer and a Visctoek HS02 Viscometer was used to monitor sample elution.

The column and detector temperatures were controlled at 40·C (104"F). Samples were prepared

by dissolving 0.20 to 0.25 grams, depending upon the rubber content, in 10 mL of THF and

filtering through a PTFE syringe fllter with a membrane pore size of 0.45 p.m (0.45 micron).

Thus, sample preparation removes all rubber particles greater than 0.45 microns, since asphalt is

soluble in THF and rubber is not.

FOURIER TRANSFORM INFRARED SPECTROSCOPY (FTIR)

A Mattson Galaxy series 5020 Spectrometer at 4 cm·1 resolution and 64 scans is used to

measure the infrared absorbance spectra of asphalt samples. In particular, the Attenuated Total

Reflectance, ATR, method with a Zinc Selenide prism is used (Jemison et aI., 1992). To quantify

the changes in the spectra, the carbonyl content is defined as the integrated absorbance from 1820

to 1650 cm-I with respect to the baseline at the absorbance of 1820 cm-I. This area is called the

Carbonyl Area or C4. The range of wave numbers includes the following carbonyl compounds:

esters, ketones, aldehydes, and carboxylic acids. The primary absorbance peak for the oxidized

asphalt is located at 1700 cm-I and corresponds to ketone formation. The carbonyl area has been

shown to be a good measure of oxidation (Liu et aI. 1995).

At low aging pressures of2 and 0.2 atm oxygen and for thick (-=Imm) fllms, oxygen

diffusion may be significant. To partially eliminate this diffusion problem, only the exposed

surface, ES, of the film is analyzed for kinetic data. For analysis, a quarter of the material in the

87

aluminum tray is removed and the ES placed on the prism face. For samples that have been aged

in thinner films, diffusion is probably not significant, so it is possible to measure the spectra of

a stirred sample. To insure good contact at the sample/prism interface, the sample is compressed.

Heating of the sample is avoided, if possible.

For measuring the spectrum of asphaltenes, the material is dissolved in THF and the

solution deposited on the A TR prism drop by drop allowing the THF to evaporate. When the film

on the prism is sufficiently thick it is further dried with a heat gun.

MICRODUCTILITY MEASUREMENTS

A detailed description of the microductility measurements can be found in Chapter 2.

, ,

c 88

APPENDIX lB

OIT SPREADSHEETS

89

Economic Analysis for a

ROSE Supercritical Unit for Producing

Aromatic Material for eRMA

90

'" .....

Projecf Name:

Filename:

Anlll/ysf:

olr Project Benefit Analysis Worksheet Version 2 . .,

Development of Asphalts 3. Pavements Using Recycled Tire Rubber

1trr95_7.XIS

ICharles Glover I This syst.m of apraadaheet. was developed 10 old In "'" 1InmncIal, morkot, ond bonoll! """Iyo'" of orr proJocts. Tho u •• r '" .sked for. number of Input. relatlog 10 both the new and """"log technolagles for. """"In proJocI, auch .. : capIIol coats, onnual coals, onorgy us., wam. reduction. oqulpmonlllratlma, discount rate and merkollnformatlon. The system will calculatotho following proJoci "''''latlc9: InRIaI capftallnves1ment. Ialol onnual coals, proJoci rmmnclollnformollon, mmrkol pm_Ion Infor",allon, not """'lIY BIIIIIr1gs and not Wlllolo reduction. Tho spread,heel, ore doolgned In ouch a way thol "'" uaor can change lnfor",,,,11on In "'" cello wIlh _1m only. The cello wIlh red Ie'" contain formulas and are locked.

Industrial Partner: Tellaa Deplllrtment of Trlllnsportation

ROSE unit for producing recycllnglllgenVauperlor IIIsphalt. The Installed cost of III ROSE unit I" $30 million for a 10,000 bblfday recycling agent produced. At 330 operating dmymlyr, this Is $9.09/bbl of RA (capital Investment). The annualized coat of producing the recycling agent Is $2.381bbl of RA (eKcludlng energy costa) leslI "n allllllumed sales price of $11.251bbl. The aneflllY savings Is sloss due 10 the anergy cost of processing the RA. This Is cslculatmd eccordlnglo 100,000 Btu/bbl of faed and 330 operating dayBlyr for the 30,000 bblfday of feed unit which produces 10,000 bblfday of RA. The energy cost la antared In the anergy &lIvlng8 work .. h .... t These assumptions plullla10% discount rata glvaan Intarnal rata of rmturn of 28% and a dlscountad payb .. ck period of 4.4 y .... ra. Ths en .. rgy u ... for this pracellllllis 990,000 million Btu/yr (100,000 Btu/Bbl of faed, 30,000 Bbl of

faed/day, and 330 opsrmtlng dayelyrl·

5130196

\0 N

1 2 3 4 5 e 7 8

9

10

SheelA

Capital Investment Worlcsheet

Capital Cost Component

FInIt Cost of Equipment SR. Prepormllon and Englneorlng Installation Contingency Allowance Construction indirect Coste Interest During ConstrucIIon Start-up Expen ..... ~orkIng C.pIlmI Qther.,

TOTAL: Initial Capital Investment

Coste ehould be onIorod In 1994 cIo!mJ.

5130196

DlIII8lopment of Asphafls & Pavemenllo Using Recycled TIre Rubber

ConvenUonal New Unit Incremental Incremental Net Cost Unit Capital Costs Savings Increment

S - S -. - $ - $ -S - $ - $ - $ - $ -$ - $ - s - $ - $ -S - . - S - S - $ -$ - s - $ - $ - $ -S -. - S - $ - $ -• -. - $ - $ - $ -• - S - $ - $ - $ -S - S

. 30, __ S 30,000,000 • - $ 30,000,000

$ - $ 30,000,000 $ 30,000,000 $ - $ 30,000,000

Equipment Cost Index 1988 797.8 1991 930.0 1987 .,3.0 1992 943.1 1988 852.0 1993 984.2 1988 895.1 1994 993.4 1980 tllS.l 19S5 1015.3 -----_.-

Source: Marnhal & Swlft Equipment Cost Index Chemical Ellglneerlng Mogazlne; McGraw-HI!, Inc. Now YorI<, NY. (19S51ndox Is estfmaIod.) ,

1 2 3 4 5

e

\0 7 w

SheeiB

Annual (non-energy) Cost Worksheet

Annual Cost Component PayroD pfus Labor Indlreclll Operllllng Supplies Maintenance Supplies TrmnspoftaSon PoluSon Control mnd Waste DIIIpose! other Costs/Credits

TOTAL: Annual (non-enerUllt<:_C)sls_

Coots should be entered In 1994 doll",".

5130196

Development of Asphl!!ts & Pavements Using Recycled TIre RubbeJ!

Conventional New Unit Incremental Incremental Net Cost Unit Annual Costs Savings Increment

$ - $ - $ -$ - $ - $ - $ -• - $ - $ - $ - $ -

S - $ - $ - $ - $ -$ - $ - $ - .

$ - $ 11211370001 $ - $ 12837000 $ (12,837,OOO)

$ - $ 112,837,000) $ - $ 12,837,~00 _t (12,837,000)

Sh881 C

Energy Savings Worksheet

Annual Unit Energy Use Net IMiliion Btutyearl Energy

Conventional New Saved Technol2l!l Technol2l!l

I O_eOD 850,000 (990,000) 2 ReoldumlOR 3 Natural Gao 4 Propane 5 Geolne 6 ColdngCoal 7 St .. mCoal

'" 8 EIsctrIcIy ~

9 other 10 IJBo by Othere .

II TOTAL 990,000 (990,000,

Expraoa ond-uoe olocbldly ..... ao prIrmKy equIwIont (10,500 1ItuIkWh)

Energy Ssvtng8: Only nat ...... "" __ pmrIded for the enelyo"'.

Oovalopmenl of AsphoRs & P"""",onI. thllng Recycled The Rubber

12 13 14 15 Ie 17 18 19 20

Default 1994 Fuel Prices 1994 Fuel Prices· ($ per million Btu) ($ per million Btu)

Olsllllale on 4.12 Olsllllal. OD 4.12 R80ldual on 2035 R .. lduolOI 2.35 N""""'I G80 2.98 N""""'I Go. 2.98

Propane U8 Propane 5.66 Gaooane 8.89 Gasoline 5.89

Coldng Coal 1.53 Coking Coal 1.53 Stoam COllI t.38 St.am Cool 1.38

EIsctrIcIy 4.50 EIoctrlcIly 4.50 other 2.00 Other 2.00

---- ------

• Source: Enorgy information Administration, Monthly Energy RevIow, April 19915; Energetics, Inc. _BO.

5130/96

1 2 3 4 5 e 7 8 9

\0 10 Ln 11

12 13 14

15

Sheet 0

Waste Reduction Worksheet

Annual Unit Waste Production (TonslYear)

ConventIClriiil---Wew Technology Technology

f':!.on-t:ombU!y'on Relllted Non-hlWlrdous (RCRA) Toxic (TRI) Hazardous (non-TRI) CFCs VOC. SHH O1her2 O1her 3 O1her4

CombUstion Relllted

Particulates !l VOCe 1 Sulfur Dioxides 711 Nitrogen OxIdes al Corban Dioxide 711,1115

TOTAL 79,849.4

Net Waste

Reduction

(5) (i)

(79) (G9)

(71,895)

(79,849.4) -SHH • Sold. hydrocsrbon/orgllRlc. regulstad under hlWll'dous.

5130/96

Development of Asphalls I!. Pavemenls Using Recycled Tire Rubber

Combiiiition Emission Rates (Ibs/mlliion Btu)

Particulate. VOC. SOx NOx CO2 18 DlslBIate OB 0.010 0.002 0.160 0.140 161.000 17 Residual OR 0.080 0.009 1.700 0.370 161.000 18 Na\ureIGos 0.003 0.008 0.000 0.140 113.000 19 Propane 0.003 0.008 0.000 0.140 113.000 20 Gasoline 0.000 0.090 0.000 0.140 162.000 21 Coking Coal 0.720 0.005 2.500 0.950 208.000 22 Sleam Cae! 0.720 0.005 2.500 0.950 208.000 23 EIecIrlcIly OAOO 0.004 1.450 0.550 134.000

24 O1her 1

EleclJlclly use expressed as primary equivalent (10.500 Btu/kWh)

'" '"

1 2

3

4

ShoolE

FlnlllJncllllJ' WbrlrlBhHf

Unit Technology Inputs

DI!ICOUI1I rate: Equipment lifetime (yra.): Initial capital Investment:

Annual costs:

10% 10

$30,000,000 ($12,137,0001

5

a 7

8

• 10 11 12 13

14 15 I.

5130/98

OowIopmGnI of Asph.R. & P.""",ento Using Rocycled Tiro Rubbor J User's Unit Summary Financial Results

Annual energy Income: -$4,078,800 Annual net Income: $8,758,200

Total life Cycle Cost $30,000,000 Total life Cycle Benellt $53,815,348

Net Present Value: $23,815,348 Benefit-Cost Ratio: 1.79

Internal Rate of Return: 26.39% Rate of Return: 29.19%

Uniform Capital Recovery Factor: 0.1627 levenzed Cos! of Energy (per mil. Btu): $8.03

Annual Production Cos! Savings: $3,875,838 Dl!ICOUI1Ied Payback Period: 4.42

~ cooIlnpth .. '994$

'" "

2 3 4 5 a

Shget F

Mamef PenwlBtlon WorlrOOH' D~ of Asphalts & Pa""rnents Using Recycled Tire

Inputs

Hurdle rote IRR (%): Veor of lrtroductJon:

Number of units oIlrtroductJon: Total potontlol rnarko! (III unRs):

MOJdrnum markot ~ (fraction): Number of yuem 01 morko! aoIumtIon:

1

25% 1997

1 1

1.00 10

25 2iI

Number of Units in Operation

Market PenelraUon

Intemol Role of Return: Marko! ""a ... at lrtroduc!lon:

1 1--1-----. ·_D· __ • _____ ··_···· ___ .••• _ .•... ··_.···· •• · •• _ •. - •. - •....•.••..

1 --·1 ----.... - ... -.. -.--............ --.- ................ .

1 --... --.---.- ·--1---·_·· ........... --..... -.. .

1 ----- .• ---.------.--.~-.. ---.-.. ---.-,-.. --.-

1 ._--.. _---_._.-------_. __ ._--------\I!I------_ .. _-_.- . __ ............. -............. .

0

0 .. ----.. .g._----_.-------_.--_.-_._ ... _-_ ............... .

o t-·-o -\-... .. ..•. _-_ ..•. _---_ .. -._-_ ... -_ ............ __ ... _ ... _.-... "'.'--'--.'--'.'---"--'.'.'.'.'.'-'-" .•.•. _-_ .. _. __ ._-_ ............... . o , ,

26-4 100-4

tm .... 200!1 ato v ....

20tB 2020 ms

5I:lO.OO

5130/96

SheetG

Market Penetration Results Development of Asphalts I/, Pavements UsIng Recycled Tire R

Yemr Units In Energy Smvlngs Wmslle Reduction Prod. Cost Savings Operation million Btu/yeer tons/yesr ($/Year)

1 1995 - - - -2 1998 - - - -3 1997 1 -990,000 -79,849 3,875,838

" 1998 1 -990,000 -79,849 3,875,838 5 1999 1 -990,000 -79,849 3,875,838 6 2000 1 -990,000 -79,849 3,875,838 7 2001 1 -990,000 -79,849 3,875,838 8 2002 1 -990,000 -79,849 3,875,838 9 2003 1 -990,000 -79,849 3,875,838 10 2004 1 -990,000 -79,1149 3,875,838 11

'" 12 '" 2005 1 -990,000 -79,849 3,875,838 2008 1 -990,000 -79,849 3,875,838

13 2007 1 -990,000 -79,1149 3,875,838 14 2008 0 0 0 0 15 2009 0 0 0 0 16 2010 0 0 0 0 17 2011 0 0 0 0 18 2012 0 0 0 0 19 2013 0 0 0 0 20 2014 0 0 0 0 21 2015 0 0 0 0 22 2016 0 0 0 0 23 2017 0 0 0 0 24 2018 0 0 0 0 25 2019 0 0 0 0 2B 2020 0 0 0 0 27 2021 0 0 0 0 2B 2022 0 0 0 0

29 2023 0 0 0 0 30 2024 0 0 0 0 31 2025 0 0 0 0

1 2 3 4 5 a 7 8

8

'" 10 '" 11

12 13 14 15 IS

Sheet H

Tota' Eng'11Y SavlnglB

Number of

Year Units In DI8t1"211111

Operation 0" 1990 - -1995 - -2000 1 (990,000) 2005 1 (990,000) 2010 - -2015 - -2020 - -2025 - -

Year Number 01'

StslllmCoa Units In

OPlll'l!lllon 1990 - -1995 - -2000 1 -2005 1 -2010 - -2015 - -2020 - -2025 - -

5130196 Oewfopment or AsphllRa & Pavements Using Recycled Tire Rubber

Energy Savings by Fuel Type Cmlllion Btu",

ResIdual 0" Natural G.8 Propane Ga80llne Coking Coal

- - - - -- - - - -- - - - -- - - - -- - - - -- - - - -- - - - -- - - - -

EIIICtrlclty othlll' Totsl Enl!lrgy Savlnga

mlRlonatus 19114$

- - - -- - - -- - (990,000) (4,078,800)

- - (990,000) (4,078,800) - - - -- - - -- - - -- - - -

1 2 3 4 9 a 1 8

D 1" 1 " ~ I-' 12

01 o 1

1 1 : 8

Sheet I 5r.J019S Tolat Waste Reduction Development or Asphalb & Pavements Using Recycled Tlra Rubber

Waste ReducUon by Waste Type (tons) .......... l1li Non-Combustlon Related ...........

Number of Non-hazanlous Hazanlouo Units In (RCM) Toxic (TRI) (non-TRI) CFCs voc. IIHH OIlIer 2 0lIl ... 3 OIlIer 4

Va. OperaHan

1990 - - - - - - - - - -1995 - - - - - - - - - -2000 1 - - - - - - - - -2005 1 - '" - - - - - - -201D - - - - - - - - - -2015 - - - - - - - - - -2020 - - - - - - - - - -2025 - - - - - - - - - -

Waste ReducUon by Waste Type (tons) .......... ,. Combustion Related· .......... TOTAL

Number of lIutrur NHrogI!ll Ct!Irban WASTE Units In PlI!rtIcstetes voc. Dioxides Oxide. DIoxide REDUCTION

Va. OperaUon lton., 1990 - - - - - - -1995 - - - - - - -2000 1 (5) (1) (19) (69) (19,695) (19,849) 2005 1 (5) (1) (19) (69) (19,695) (19,849) 201D - - - - - - -2015 - . . . . . -2020 - - - - - - -2025 - - - - - - - - -

Economic Comparison of a

Conventional Aspbalt, 12-Year Pavement

witb a

CRMA, IS-Year Pavement

101

..... o N

Project Name:

Filename:

Analyst:

OIT Project Benefit Analysis Worksheet Version 2.1

Development of Asphalts 3. Pavements Using Recycled Tire Rubber

ITRf95_3.xIS

ICharies Glover I This systom 01 spreodshoels was dovotoped 10 old In the nnsnclal, marlo!!, and bonefilonBlysls 01 OIT projects. Tho user Is asked for s number of Inputs relating to boIh the new and mdsIfng technologies for. certain proJod, such .s: capRal costs, .nnual costs, anorgy USB, waste reduction. oqulpmont 1Ifotlme, discount l1IIa mnd morlo!!lnI'ormalion. Tho systam \'An calculalathe foIto\'Ang proJmct statlsllca: Inftlsl capftBllnwstment, totalonnual costs, proJmct Onanclallnflll,,_, _ plliObatloillnformallon, nat anergy sol.!ngs and nat wasta roductlon. The spreadsheets .'" dasIgnod In ouch. waytha! the user can chongo hirom_11n the caIIo __ tmt only. Tho caIIo _ rod telt contsln lonnulas snd .", locked.

Industrial Partner: Tellms Department of Transportallon

Comport ..... bet ... on .,. con_I pavement plac&nentlhavfng an ........ ed"r.. 01 12 yo ..... ,_ b,. ouperlor a""haHlCRM pavement pI ....... ent Iv.fth an ........ ed or.. of 11 yeara'. AI ... , II I ......... ed thollha annuo' coolin both ca .... equo'. the Iioial <splta' cool 01 Iha conventional pavement)llyra _.114 and thollha CRM cententln tho binder ,. 10% and dI""loc •• an equlv.lent .... ounI of aophaH binder, thereby ",mulling In both Wllole reduction and energy savlnglL Ho ... v .... It ,. osoumed Ihol Iha pr_ng coo! wm offoot Iha b'nder energy oavfnglL For th' •• nary .... 10 mesh crumb rub ..... '. asoumed, 01. coot 01 $O.1411bm. A'ao, e CRMA binder procasalng cool of $2&IIon of binder ,. aeaumed lor blending and curing the CRM and .""han and. price 01 $103.l!IIon Iplu.the procesalng cool". placed on Iha .""holt molerla', .nowng lor 1110 be. designed molerlal of 00% .""".11101 $IOD/Ion,ond 10%"",,,,0110 malerla'ial $13&/Ion~ Tho required blnderlo"""all plu. rub ..... ' 'n the pavanent'. taken 10 be 8% 1IIIHh th .. " aoaumptlons pluo 0 10% discount not. ,Iha Internal not. of return ,. 14.0% and the dIscounted

paybeck period ,. D.3 ye .......

5130196

.... o w

2 3

4 5 6 7 6

9

10

SheelA

Capital Investment Worksheet

Capital Cost Component

First Cost of Equipment Sfte Preparation and Englnoerlng InstaRmllon Contingency AIIowanca Construction indirect Costa Interest During Construction S1art-up Expon ..... Working CopRal other.

TOTAL: Initial Capltallnvesiment

Cost. should .... ontored In 1994 doIIare •

Development of AsphaRs & Pavemant. Using Recycled Tire Rubber

Conventional New Unit Incremental Unit Capital Costs

$ 31,883 $ 44,083 $ 12,200 $ $ - $ - $ - $ $ 88,217 $ 88,217 $ - $ $ - $ - $ - $ S - $ - $ - $ • - $ - $ - $ $ - S - $ - $ $ - $ - $ - $ $ - $ - $ - s $ 98,100 $ 110,300 $ 12,200 $

Equipment Cost Index 1986 787.6 1991 1997 813.8 1992 1986 852.0 1993 1999 895.1 1994 1990 915.1 1995

Source: Marehal & SwIft EqulpmGnl Cost Indox Chamleel Englnaerlng Magazine; McGraw-HI!I, Inc. New York, NY. (l995lndox Is estimated.)

Incremental Net Cost I Savings Increment

- $ 12,200 - $ -- $ -- $ -- $ -- $ -- $ -- $ -- $ -- $ 12,20Q I

930.6 943.1 964.2 993.4 1015.3

5130196

.....

1 2 3 4 5

6

~ 7

Sheet B

Annual (non-energy) Cost Worksheet

AnnualCostComDonent Payroll plus Labor Indlrects Opemllng Supplies Maintenance Supplies Tmnsportatlon PoIluUon Control and Wast" Disposal

Othllll' Costs/Creel""

TOTAL: Annual (non-energy' Costs

Costs should be entered In 1994 doIlmn •.

Conventional Unit

S

• - . S - . S 3,11711 S

1- 3.S7~ $

5130196

Development of Asphalts & Pavements Using Recycled Tire Rubb

New Unit Incremental Incremental Net Cost Annual Costs Savings Increment

S - $ - $ -- $ - $ - $ -- $ - $ - $ -- . - $ - $ -

$ - $ - $ -U3fI $ - $ 2,043 $ (2,043)

'D,S31i . .t __ - $ 2,043 $ (2,043)

-a OJ>

Sheet C

1 2 3 4 5 6 7 8 9 10

11

Energy Savings Worksheet

Distillate all Resldual all Natural Gas Propane Gasoflne Coking Coal steam Coal Electrlclty Other Use by Others

TOTAL

Annual Unit Energy Use (Million IBtuiyear)

Conventional New Technology Technology

1145 1123

545 523

Net Energy Saved

22

22

Express end-use electrlclty use as primary equivalent (10,500 Btu/kWh)

Energy Savings: Only net savings were provided for the analysis.

5/30/96

Development of Asphalts & Pavements Using Recycl ed Tire Rubber

12 13 14 15 16

I 17 111 19 20

I

Default 1994 Fuel Prices 1994 Fuel Prices' ($ per million Btu) ($ per million Btu)

DIstillate all 4.12 Distillate Oil 4.12 Residual all 2.35 Residual Oil 2.35 Natural Gas 2.96 Natural Gas 2.96

Propane 5.66 Propane 5.66 Gasoline 5.89 Gasoline 5.89

Coking Coal 1.53 Coking Coal 1.53 steam Coal 1.36 Steam Coal 1.36

Electrlclty 4.50 Electricity 4.50 Other 2.00 Other 2.00

• Source: Energy Information Administration, Monthly Energy Review, April 1995; Energetics. Inc. estimates.

5130/96

She"tD

Waste Reduction Worksheet Development of Asphalts & Pavemenls Using Recycled Tire Rubber

Annuml Unit Waste Production Net !TonsNearl Waste

Conventional New Reduction Technology Technology Combustion EmiSSion Rates 1 (Ibs/million Btu)

Non-combu$tlon RlIIsted 1 Non-hazardous (RCRA) 273 2111 55 Por1lculat •• VOC. sax NOx CO2

2 Toxic (TRI) 18 DlstBIat. aD 0.010 0.002 0.160 0.140 161.000

3 Hazardous (no ... TRI) 17 Resldu.IOD 0.080 0.009 1.700 0.370 161.000

4 CFC. 18 NaturalGos 0.003 0.006 0.000 0.140 113.000

5 VOC. 19 Propane 0.003 0.006 0.000 0.140 113.000

8 SHH 20 GasoDne 0.000 0.090 0.000 0.140 162.000

7 Other 2 21 Coking Coal 0.720 0.005 2.500 0.950 208.000

8 Other 3 22 Steom Coml 0.720 0.005 2.500 0.950 208.000

9 Other .. 23 Elec!rlclly 0.400 0.004 1.450 0.550 134.000

Combu$tlon Related 24 Other 1

.... 10 Particulate. 0 0 0 0 a- II VOC. 0 0 0 EIec!rlcIIy usa expressed a. primary equivalent (10,500 Btu/kWh)

12 Sulfur Dloxfde. 1 1 0 13 Nitrogen Oxfdes 0 0 0 14 Carbon Dloxfde 57 54 2

15 TOTAL 330.8 273.5 57.3

SHH • SoRd, hydrocarbon/organic, regulated under hazardous.

..... a

"

2

3

4

Sheet E

Flmmclll' WorirshHf

Unit TechnololJ~lnputs

Discount rate: Equipment Ilfe6me (yrs.): InlUal capHallnvestment

Annual costs:

10% 111

$12,200 ($2,043)

5 8

7

8

• 10 11

12 13

14 15 18

51301'96

Development of Asphafts & Pavements Using Recycled TIre Rubber

User's Unit Summary Financia! Results

Annual energy Income: $34 Annual net Income: $2,077

Total life Cycle Cost $12,200 Total life Cycle Benefit $15,795

Net Present Value: $3,595 Benefit-Cos! RaUo: 1.29

Internal Rate of Return: 14.90% Rate of Return: 17.02%

Uniform Capital Recovery Factor: 0.1315 Levellzed Cos! of Energy (per mil. Btu): -$19.96

Annual ProducUon Cost Savings: $473 Discounted Payback Period: 9.30

~ coeIlnpuIB .. ,994$

..... o (XI-

2 3 4 5 a

Sheet F . MllIrlref Penefrlllflon Worlrsheef Oavalopmon! 0' A'phaRo & P.""ment. Using Recycled Tire

Inputs

HUldIe mle IRR 1%': YOM 01 lntroducIIon:

Number 0' units III! introduction: lo!lll poton!laIlI1IIr1<l!t III unR.,:

Mmdmum mar1<l!t ponoImtIon 1_': Number of Y""'" at II1IIr1<l!t _on:

26% 11197 61!OO

2,660,660.00 0.33

10

25 2!1

Number of Units in Operation

Market PenetraUon

Intemal Rat. Dr Return: Markel: shIre at Jntroductlon:

1~'-----------------------------------------~

1:moo

10000 ---------_._--_._----_._-_._._._. __ ..... _._ ... __ ._.-

eooo ~ --8 ~ --------------... ---.-.--.-... --.--.-.-.-.. -.-.-...

eooo -\-.---, '10.

~

:moo

o , ... .... 200!! "'0 Ye ...

.. ,. 2020 2025

15% 1%

5I:lO.96

5130196

Sheet G

Marlcet Penetration Results Development of Asphmlts & Pavements Using Recycled nre R

Year Units In Energy Savings lIIfum Reduction Prod. Cost Savings Operation mil/ion Btulyear tonslyear ($lYear)

1 2 ~=

. . . .

. . . . 3 1997 5500 121,000 315,337 2,599,740 4 1998 13271 291,982 780,879 8,272,935 5 1999 10653 234,368 810,no 5,035,459 8 2000 11545 187,990 489,9111 4,039,050 7 2001 8849 150,878 392,680 3,237,385 8 2002 5488 120,736 314,649 2,594,067 9 2003 4395 96,690 251,983 2,on,428 10 2004 3518 n,396 201,701 1,662,888 - 11

0 12 '"

2005 2816 61,952 161,452 1,331,067 2008 2253 49,588 129,173 1,064,948

13 2007 1803 39,666 103,373 852,242 14 2008 1442 31,724 82,676 681,604 15 2()()g 1154 25,388 88,163 545,473 18 2010 923 20,306 52,919 438,284 17 2011 736 16,236 42,312 348,838 18 2012 590 12,980 33,827 278,881 19 2013 472 10,384 27,062 223,105 20 2014 3n 11,294 21,615 178,200 21 2015 302 6,644 17,315 142,749 22 2016 241 5,302 13,817 113,916 23 2017 193 "',248 11,065 91,227 24 2018 154 3,388 8,829 72,793 25 2019 123 2,706 7,052 58,140 2B 2020 99 2,178 5,676 46,795 27 2021 79 1,738 4,529 37,342 2B 2022 63 1,386 3,612 29,779

29 2023 50 1,100 2,867 23,634

30 2024 40 880 2,293 18,907

31 2025 32 704 1,835 15,126

..... ..... o

1 2 3 4 5 a 7 B

8 10 11 12 13 14 15 18

Sheet H

Tofal Energy Savings

Number of

Y"ar Units In Disollata

Operaoon 011

1990 - -1995 - -2000 8,545 -2005 2,818 -2010 923 -2015 302 -2020 99 -2025 ~.:-~- 32 -

Yelll' Number of Staam Coa! Unitl!lln

Oaraoon 1990 - -1995 - -2000 8,545 -

,2005 2,818 -2010 923 -2015 302 -2020 99 -2025 32 -

5130196

Development of Asphofts & Pavements Using Recycled Tire Rubber

En"rgy Savings by Fu,,1 Typ" {million Btus,

Residual Oil NaturalOaa Propane Oallolln" Coking Coal

- - - - - !

- - - - - i

- - - - 187,990

- - - - 61,952

- - - - 20,306

- - - - 6,644

- - - - 2,178

- - - - 704

Electricity Otb8f Total Energy Savings

mlltlon StIllS 1994$

- - - -- - - -- - 187,990 287,625

- - 81,952 94,787

- - 20,306 31,OBB

- - 8,644 10,165

- - 2,178 3,332

- - 704 1,077

, 2

• • • 8 7

•

• • , • ,

..... '

..... ' ..... ,

, , 2

• • • 8

Sheet I 5130f98 Total West" Reduction Development d Allphafta & pavements oDlnp Rm:ycled Tlre Rubber

Waste Reduction by Waste Type (Ionol ••• •• Non-Combuatlon Related· ••••

Number 01 Non..f1azardoulIJ Hazardous UnHsln (RCRAI TOlle (TRII (non-TRII CFC. VOCe SHH other 2 oth.,,3 other 4

Vear Oparallon

1990 . · · · · · · · · · 1995 . · · · · · · · · · 2000 8,545 489,975 · · · · · · · · 2005 2,818 154,880 · ~ · · · · · · 2010 923 50,7115 · · · · · · · · 201. 302 10,810 - · · - · · · · 2020 99 '.445 · · · - - · · · 2025 32 1.7!IO - · · · · · · ·

Wast. Reduction by waste Typo Ilonol •••• • Combullltlon Refated· •••• TOTAL

Num .... ol Sulfur Nitrogen Cerbon WASTE Unltoln P""_o. VOCa Dlolldea Oxide. ilIollds REDUC110N

v .... O ..... mllon Ilonol '900 . · - · · · · 1995 . · · · · · · 2000 0,545 88 0 23. 00 1 •••• 1 488,818 2005 2,818 22 0 T7 211 8.443 101.'52 2010 923 7 0 2!1 10 2,112 02,91. 201. 302 2 0 8 S 881 17.st. 2020 99 1 0 3 1 227 5,8711 2025 32

, _ 0 0 1 0 7S 1.835

Economic Comparison of a

Conventional Asphalt, 12· Year Pavement

with a

CRMA, 18· Year Pavement

112

.... .... w

Project Name:

Filename:

Analyst:

OIT Project Benefit Analysis Worksheet Version 2.1

Development of Asphalts & Pavements Using Recycled nre Rubber

ITRf95_ 4.xls

ICharles Glover I Thlo ayaIom of opreadsoom. _ d .... 1oped 10 mid In the IInImcIoI, ma"".I, ond benall! .""!yolo of OfT p!UJocts. The user Is .sked for a number of

Inpuls roIoIIng t. both the new and exlotlng loChnoIogIae for a certain p!UJee!, much as: ""plio! costs, annuel costo, energy u .. , wasle reduction,

equipment lifetime, dIocount rate and merltGt Infonnatlon. The ayaIom will cafcuIotethe following p!UJee! sI_: InRIaI capftallnveslment.

lotal.nnuol costs, proJee!linanclollnfonnellon, markllt paIftItJ"lI.iI Infonnellon, not anergy oavIngtI and not WIlsie reduction. The spreadsheets 0 .. designed In 8UCh a WfIY _the ....... ClIO ""-Moo",.II.h In the ___ taxi only. The __ nod text conIaln fonnulas and

0 .. !ockad.

Indumtrlml Partner: Tel!!!e Department of Trmnllportntlon

Comp .... son between ., • conlllHlllonal pm""""",t pI .... ment (having an assumed me of 12 Y" ..... , WIth b, •• uperlor asph.,tlCRM pa""""",t placement (wtIII an ossumed life of 18 Y"I!I'S'. Also, It I ••• sumed that the annual cost In both cases equals the (Iolal capital cost of the conlllHlllonal pmvemenl)l(yrs """"")14 ond that the CRM conlent In the bind ... I. 10% and displaces an equivalent amount of .sphalt bind ... , thEreby resulUngln both wasta reducHon and enorgy .... vlng.. HoweVEr, It Is assumed that the processing cost will _I the bind ... enorgy .. Vlngs. Far this analysis, 10 mesh crumb rubbor I. a.sumed, at • cost of SO.1411bm. Also, a CRMA binder .....,., ••• ,ng cost of $Z5Iton of binder I. assumed far blending and clBlng the CRM and asphalt .nd • price of $103.5Iton (plus the processing cost, I. placed on the asphalt ma_', .noWlng far It to be • designed m.ter1al 01 90% a.phalt (al StOOIton, and 10% .... mallc mater1al (at $1351ton,. The requlrod binder (a'phalt plus rubbor, In the pavement Is taken to ba 8%. WIth \hess assumpHon. plu. a 10% discount rata, the Internsl reta of retum I. 29.0% and a discounted payback

period of 4.4 yes •.

5/30/96

..... ..... ..,.

1 2 3 4

5 8 7 a 9

10

Shonl A

Capital Investment Worlcsheet

Capital Cost Component

FIrot Cost of Equipment SMa Praparmllon and Engln80flng Installation ContIng&ncy AIIowanca Construction IndImct Costs Il1Ierest During Construction Start·up Expenses Working Capftsl

Other:

TOTAL: Initial Capital Investment

Costs ""auld be entorad In 1994 doIIsrs •

Development of Asphafts & Pavements Using Recycled Tire Rubber

Conventional New Unit Incremental Unit Capital Costs

$ 31,883 • 44,083 • 12,200 $ $ • $ • • - $ $ 88,217 • 88,217 $ • $ S • • • $ - $ $ • • -. - $ • - s • • - . • • $ • $ • $ $ • $ • $ - $ S • $ • $ - $

$ 98,100 $ 110,300 $ 12,200 $

Equipment Cost Index 1988 797.1 1991 1987 813.8 1992 1988 852.0 1993 1989 899.1 1994 1980 "5.' 1995

lIoun:a: Marshal & SWIll EquIpment Cost Ind"" Chemical EngIntiaI1no Magazine; McGrsw-HII, Inc. Now York, NY. (19951nd",," estbnatod.)

Incremental Net Cost Savings Increment

- $ 12,200 !

- $ -- $ · - $ -- $ · - $ · - $ -- $ -- s · . $ 12,200

930.6 943.1 964.2 993.4 1015.3

5i3OI96

.....

1 2 3 <4 5 B

::;:7

Sheet B

Annual (non-energy) Cost Worlrsheet

Annual Cost Component Payroll plus labor Indlrects Opemllng Supplies Mmlntenrmce Supplies Tnonspor1atlon PolluUon Control and Waste Disposal other Costs/Credits

TOTAL: Annual (non-energy) Costs

Costs should be entered In 1994 dollars.

Conventional Unit

• S - $ • - S

$ 4,770 $

$ 4,770 $

5/30/96

Development of Asphalts & Pavements UsIng Recycled Tire Rubb

New Unit Incremental Incremental Net Cost Annual Costs Savings Increment

• - $ - $ -- $ - $ - $ -- $ - $ - $ -- S - $ - $ -

$ - $ - $ -1,3112 $ - $ 3,408 $ (3,408

1,362 $ - $ 3,408 $ (3,408)

Sheet C

1 2 3

.... 4 ;; 5

6 7 II 9 10 11

Energy Savings Worksheet

-Annual Unit Energy Use (MIllion Btu/year)

Conventional New I Technology Technolo

Distillate 011 Residual Oli Natural Gas Propane Gasoline Coldng Coal 6411 438 Steam Coal Electricity O1her Use by Others

TOTAL 545 436

Net Energy Saved

1011

109

Express end-use electricity use as primary equivalent (10,500 BtulkVllh)

Energy Savings: Only net savings were provided for the analysis.

5/30/96

Development of Asphalts & Pavements Using Recycled Tire Rubber

12 13 14 15 111

I 17 18 19 20

I

Default 1994 Fuel Prices 1994 Fuel Prices' ($ per million Btu) ($ per million Btu)

Distillate 011 4.12 Distillate Oil 4.12 Residual 011 2.35 Residual Oil 2.35 Natural Gas 2.98 Natural Gas 2.96

Propane 5.68 Propane 5.66 Gasoline 5.119 Gasoline 5.89

Coldng Coal 1.53 Coking Coal 1.53 Steam Coal 1.36 Steam Coal 1.36

Electricity 4.50 Electricity 4.50 Other 2.00 Other 2.00

• Soun:e: Energy Information Administration, Monthly Energy Review, April 1995; Energetics. Inc. estlmates.

5/30/96

Sh •• tD

Waste Reduction Worksheet Development of Asphalts & Pavements Using Recycled Tire Rubber

Annual Unit Waste Production Net !TonsNear) Waste

Conventional New Reduction Technology Technology

Non-combustJon Rellllted 1 Non-hazardous (RCRA) 273 162 111 Parlfculates VOC. SOx NOx CO2 2 Toxic (TRI) 18 Distillate 00 0.010 0.002 0.160 0.140 161.000 3 Hazardous (non-TRI) 17 Re.lduolOI 0.080 0.009 1.700 0.370 161.000 4 CFCs 18 Natur.IGa. 0.003 0.006 0.000 0.140 113.000 5 VOCs 19 Propane 0.003 0.006 0.000 0.140 113.000 8 SHH 20 Gmsolne 0.000 0.090 0.000 0.140 162.000 7 Other 2 21 Colmg Co"" 0.720 0.005 2.500 0.950 208.000 e Other 3 22 Stemm Coal 0.720 0.005 2.500 0.950 208.000 9 Other 4 23 Elec:1rlcfly 0.400 0.004 1.450 0.550 134.000

CombustIon Rellllted 24 Other 1 .....

Po_ales 0 0 0 ..... 10 .... 11 VOCs 0 0 0 Elec:1rlcflyuse expressed as primary equivalent (10.500 BlulkWh) 12 Sulfur Dloxfde. 1 1 0 13 Nitrogen OxIde. 0 0 0 14 Corbon Dloxfde S7 45 11

15 TOTAL 330.8 228.3 102.6

SHH • Sol~, hydrocarbon/organic, regulated IDlder hazardous.

.... .... 00

2

3

4

Sheet E

Flnlllncl.' Worlraheef

Unit Technology Inputs

Discount rate: Equipment lifetime (yrs.): Initial capHallnvestment

Annual costs:

10% 111

$12,200 ($3,4011,

5

8

7

8

• 10

II

12

13

14

IS 18

5130198

OawIopment of Asphalts & Pavements Using Recycled TIre Rubber

User's Unit Summary Financial Results

Annual energy Income: $167 Annual net Income: $3,575

Total Ute Cycle Cost $12,200 Total Ute Cycle Benefit $29,318

Net Pre.ent Value: $17,118 Benefit-Cost RaUo: 2.40

Intemal Rate of Return: 29.00% Rate of Return: 29.30%

Uniform CapItaJ Recovery Factor: 0.1219

LeveOzed Cos! of Energy (per mO. Btu): -$11' .';2

Annual ProducUon Cost Savfngs: $2,087 Discounted Payback Pertod: 4.39

Elqnoa cooIlnpul. as 1994$

.... .... '"

1 2 3 4 5 8

Sheet F

Marlcef P.".hflon WorlrMH' Dowlopmentof AsphaRs & Pavements Using Roc)tled Tire

Inputs

HunfI. rutolRR (%1: VOIr 01 introduction:

Number 01 0015 ot introduction: Total potential morlall (II 00151:

Mmdmum morIaII pe""tll,full (_,: Number oIyoaro ot morIaII_:

leooco

l4OOCO

28% 1897 8Il00

2,000,000.00 0.33

10

2S 211

Number of Units In Operation

Market Penetration

Internsl Rote of Return: Marlallsh.", ot introduction:

--_ .............. _. __ ._ ...... .

12DOOO -.-.----.----.. .._---------_ ... __ ._------_ ............. _ .................... .

100000 f-- .. ---... -... -...... -...... -........... .

eooco -1--.--.-.. --.---.. -.---

eooco .. ~--..... --... -.-....... -.-................................. .

4OOCO -1-....... ----..... -.----- ...... -=--... -.... -----........ -.... -.-........ -. 2JOOO -1-..... ""'-''''''''-''''';;p .......... ----.. ----.......... -.-.-........ ---..... -- ...... - .................... - .... --_ .. - ... -......... .. ... - ....... - .............. .

o ~ I

1195 2000 2005 2010 2018 2020 2025

v ....

29% 1%

5fJO/96

5/30/96

Sheet G

Maricet Penetration Results Development of Asphalts & Pavements Using Recycled TIre R

Year Units In Energy Savings Waslle Reduction Prod. Cost Savings

1 2

Operation million Btulyesr tons/yesr ~$lYeatl

~~ - - - -- - - -3 1987 5500 599,500 564,099 11,479,717

" 1988 18007 1,982,783 1,846,882 37,584,594 5 199Q 19827 2,139,343 2,013,015 40,965,892 8 2000 21389 2,331,401 2,193,732 44,643,576 7 2001 23303 2,540,027 2,390,038 48,838,518 8 2002 25382 2,766,638 2,603,266 52,977,851 9 2003 27838 3,012,542 2,1134,651 57,686,622 10 2004 3OOIl8 3,279,374 3,085,727 82,796,140 ..... , 11

N 0 12

2005 32739 3,568,551 3,357,828 68,333,538 200B 35812 3,B81,7OIl 3,652,493 74,330,125

13 2007 38723 4,220,807 3,971,568 80,823,470 14 2008 42087 4,587,483 4,318,592 87,844,882 15 2009 45722 4,983,1198 4,689,410 95,431,932 16 2010 49848 5,411,414 5,091,869 103,822,188 17 2011 53878 5,872,702 5,525,9111 112,455,309 16 2012 584311 11,369,524 5,993,403 121,968,883 19 2013 83340 11,904,080 11,498,374 132,204,596 20 2014 681101l 7,4711,272 7,036,1179 143,200,078 21 2015 742111 8,094,449 7,1118,471 154,99Q,140 22 2018 80318 11,754,882 11,237,698 187,641,439 23 2017 118795 9,480,855 8,902,002 181,160,372 24 2018 93712 . 10,214,1IOIl 9,811,434 195,597,681 25 2019 101084 11,018,158 10,387,533 210,984,677 2B 2020 108925 11,1172,825 11,171,733 227,350,579 27 2021 117248 12,780,032 12,025,370 244,722,522 2B 2022 121101l3 13,740,867 12,929,467 263,121,377 29 2023 135377 14,758,093 13,884,744 282,561,758 30 2024 145195 15,828,255 14,891,713 303,054,095 31 2025 155515 18,951,135 15,950,169 324,594,219

.... '" ....

I 2 3 4 5 B 7 D

• 10 II 12 I' 14 15 18

Sheol H

Totll' Energy SlIvlngs

Number of

Year Units In Distillate Operation Oil

1990 - -1995 - -2000 21,389 -2005 32,739 -2010 ~,646 -2015 74,261 -2020 108,925 -2025 155,515 -

Yelll' Number"f Staam Coml Units In

Opersllon 1990 - -1995 - -2000 21,389 -2005 32,739 -2010 ~,646 -2015 74,261 -2020 108,925 -2025 155,515 -

- L_ _

5/30196 I -Development of AaphBRD & Pavements Using Recycled TIre Rubber

Energy Savings by Fuel Type (million Blus)

Residual Oil NsturalOms Propane Omsollne Coking Coal

- - - - -- - - - -- - - - 2,331,~01

- - - - 3,56B,551 - - - - 5,411,414

- - - - 8,094,449,

- - - - I I ,872,8251 - - - - 16,951,135

Electricity OIlIer Total Energy Savings

mlmanS'1IIiII 1994$

- - - -,- - - -- - 2,331,401 3,567,044 - - 3,568,551 5,459,883

- - 5,411,414 8,279,463 - - 6,094,~ 12,384,507 - - 11,672,825 18,155,422

- - 16,951,135 25,935,237 -

2

• • • • 7 8

• 1. , t: ,

..... ' N' N"

Sheet I Tota' Waste Reduction Dewtopment 01 AlphDIla &. Pavementa Ustna Recycled Tlra Rubber

Wilst. Reducllon by Wast. Typ. lIons) •••• • Non-Combumtlon Related··· ••

Number 01 Non-haZMdous Hazardous Unlt.'n IRCRA) Toxic ITRI) Inon-TRI) CFC. VOC. SHH 0IIJ ... 2 other 3

Ve. Operallon

1990 0 0 0 0 0 0 0 0

1995 0 0 0 0 0 0 0 0

2000 21,389 1,8411,399 0 0 0 0 0 0

2005 32,739 2,879,24. 0 0 0 0 0 0

2010 49,848 4,517,7811 0 0 0 0 0 0

2015 74,201 8,757,751 0 0 0 0 0 0

2020 108,825 .,812,175 0 0 0 0 0 0

202S 155,515 14,151,8115 0 0 0 0 0 0

lIVasle on by WOsle T~ ~Ion.) •••• • Combustion Related· •••• TOTAL

Number 01 Sull'ur NIIrogen Corbon WASTE Unit. In Pll!ltlcutate. VOCe DIoxide. Oxide. DIoxide REDUC110N

V .... Operation (tona) 1880 0 0 0 0 0 0 0

1985 0 0 0 0 0 0 0

2000 21,3B8 638 8 2,814 1,107 242,_ 2,1.',732 2005 32,738 t,285 • 4,4111 1,115 371,121 ',357,828 2010 49,848 1,848 14 8,784 2,578 S02,797 G,081,888 2015 74,211 2,814 20 10,118 3,845 841,823 7,818,471 2020 108,825 4.274 so 14,841 5,840 1.234,77' 11,171,73' 202S 155,515 .,102 42 21,18_~_ _B,~ _~.7I2,'18 ____ 1S,DS~~

5130100

other 4

0 0

0 0

0 0

0 0

0 0

0 0

0 0

0 0

Economic Comparison of a

Conventional Asphalt, 12· Year Pavement

with a

CRMA, 21·Year Pavement

123

.... '" ~

ProJecf Name:

Filename:

. Analyst:

ODT Project Benefit Analysis Worksheet Version 2.1

Development of Asphalts 3. Pavements Using Recycled Tire Rubber

ITRf9S_S.Xls

ICharkls Glover I This ayslom of ep<eedsheeta WIllI developed to aid In IIIe I'InsncIIII, markof, end beneIII analysla of OIT pmJocIs. Th. usar Is .sked for. number of Inputs rMItIng to both the new end 8ldoIIng technclogloa fer" certain "",Joct, such am: c:apbl costs, annual costs. onorgy U98, wast. reduction, equipment lIfollme, dIscounIl8Ie and marItet Inflll1rlOlhJlt. '"'" aysIem will cmlculote IIIe folluwlng pmJoct _1otIcs: InRIaI capRallnvaslment. total an""'" costs, ptJIjoct IInIIrtcIaIInfClllllii1ltHt, markof "",""'mllott 1nfllfllU!lllon, IitIt onorgy aovfngs and IitIt wasto reduction. Tho spreadsheets ano d ... lgned In ouch a waylltslthe _ CIIh chImga ..v",,,tIIIIIott In the ..... wIIIt green t8lII only. '""' ..... wIIh red toxt cont.1n formulas and oro locked.

Industrial Partner. Tellas Depl!lrirnent of Transportation

Compmrlson between a) • convenllonal pavement placement (having an assumed IIfa or 12 Y"ar.) with h) • supmrlor asphaltlCRM pavemtHtt placement (with an a.sumed IIfa or 21 years). Also, It Is assumed that tha annual cost In both cases equals the (Iotal capital cost or the con\llllillonal pavemtHtt)l(yrs ..vIce)l4 snd that tha CRM content In tha bind ... I. 10% and displaces an equivalent lIiiiOunt or asphalt bind .... th .... by ..... uHlno In both wasta nducllon and energy savlnos. Howev ... , It Is assumed Utat the pnJCf!ss\ng cost will offset the bind ... energy savings. Far thl. analysiS, 10 mesh crumb ntbber Is •• sumed, .ta cost 01 $0.1411hm. Also. II CRMA bind ... pnJCf!sslno cost or $2!11ton or binder ... assumed for blending and curlno the CRM and asphalt and a prlce or S103.!IIton (plus the processing cost) Is placed on the asphalt rna""'.I, .nowlno for It to be a designed material of 80% a.phalt (at S1001tonland 10% ......... Oc ma""'.1 (at $13!11ton). '"'" required binder (msphalt plus ntbber) In the pavement Is laken to be G%. WHIt these assumpUons plus a 10% discount rata,the Intern.1 rate or .... turn I. 38.0% .nd a discounted payback

period or 3.2 Y"l!!NI.

5/30/96

..... N V>

2 3 4 5 8 7 8

9

10

ShoelA

Capital Investment Worksheet

Capital Cost Component

FlmI Cost of Equipment SHe Preparation and EngInaaring I"uI.1lsl1on Centlngancy AlIowanca Construction Ind~ect Costs Int"""" During ConstrucIIon Start-up Expanses wortdng CopR11

other:

TOTAL: Initial Capltallnveslment

, costa ohould be antGI8d In 1994 cIoIIIaN •

Development of Asphalts II Povamants Using Recycled Tire Rubber

Conventional New Unit Incremental Unit Capital Costs

$ 31,883 $ 44,083 $ 12,200 S $ - . -. - S $ 88,217 $ 88,217 $ - $ $ -. -. - S • - $ - $ - $ $ - $ - $ - s $ - $ - $ - $ • - $ -. - s $ - $ - $ - $

$ 98,100 $ 110,300 $ 12,200 $

EqUipment COllt Index 1988 797.1 1991 1987 813.8 1992 1988 852.0 1993 1989 895.1 1994 1990 915.1 1995

Source: Marahall '" SwIll Equipment Cost Indox Chamlcal EngIneMlng Magazine; McGraw-HI, Inc. Now YorI<, NY. (1995 Index Is auIIn1atod.)

Incremental Net Cost •

Savings Increment ;

- $ 12,20~ I

- $ - $ -- $ -- $ -- $ -- $ -- $ -- $ -, - $ 12,200 I

930.8 943.1 964.2 993." 1015.3

5130196

.....

1 2 3 <4 5

6

~ 7

Sheet B

Annual (non-energy) Cost Worksheet

Annual Cost Component Payroll plus labor Indlrects Opermllng Supplies Maintenance Supplies Transportation Pollution Control and Waste Disposal

Other Costs/Credits

TOTAL: Annual (non-energy) Costs

Costs should be entered In 1994 dclllII'I.

Conventional Unit

S S - $

• - S

$ 8,1147 $

$ &,647 $

5/30/96

Development of Asphalts & Pavements Using Recycled 11 •• Rubb

New Unit Incremental Incremental Net Cost Annual Costs Savin as Increment

$ - $ - $ --. - $ - $ -- $ - $ - $ -- $ - $ - $ -

$ - S - $ -t 1811 • - $ 4,379 $ (4,379

1,168 $ - $ 4,379 $ (4,379)

..... '" '""

ShaetC

1 2 3 4 5 B 7 a 9 10

II

!Energy Savings Worlrsheet

Dlstll!ala OD ReoldualOU Nslural Gem Propane GosoBne ColdngCoal st ... rn Coal Elactrlclly other U88byOlh ...

TOTAL

Annual Unit Energy Use (Million Btulyear)

Conventional New TechnolcJgY---'-IechnolllgY

84!1 374

•

545 374

Nef Energy Saved

171

171

Expnosa -...... .""",lclly use .. prma.y equlvalanl (10,500 1IIuII<Wh)

Energy SavInga: Only nsfll8\llngtl wmt pnwIdod , ... tho "",,!ya"'.

Davalopmenl of Asphalts 80 P_ uolng Recycled TIre Rubber

12 13 14 15 18 17 18 19 20

Default 1994 Fuel PrIces 1994 Fuel Prices· ($ per million BbJ) ($ per million Btu)

Dlstll!alo OD 4.12 Dlstll!ale 08 4.12 ReolduslOD 2.35 ReoldualOB 2.35 NsIursIG ... 2.IIS Nslural Ga. 2.98

Ptupane 5.66 Propane 5.88 Ge"'Bne 8.88 GasoDn. 5.89

Coldng Coal 1.53 Coldng Coal 1.53 stearnC'" 1.38 stearnC'" 1.38

EIocIrIcIty 4./10 EIoctrIcIly 4.50 I 0Ih0r 2.00 OIhor 2.00

--_._--

• Sourco: Energy InfDfmsllon AdmInIolralIon. Monthly Energy RevIew. Apr1119S5; Energetlco. Inc. _atos.

5130/96

5130/96

Sheel D

Waste Reduction Worksheet Development of Asphalts & Pavements Using Recycled Tire Rubber

Annual Unit Waste Production Net !TonslYear) Waste

Conventional New Reduction Technology Technology

t!.on-eombustlon Rell/ted 1 Non-hazardous (RCRA) 273 1511 117 Particulate. VOC. SOx NOx CO2

2 Toxic (TRI) 18 Distillate OB 0.010 0.002 0.160 0.140 161.000

3 Hazardous (noR-TRI) 17 ResklualOD 0.080 0.009 1.700 0.370 161.000

4 CFCs 18 Natural Gas 0.003 0.008 0.000 0.140 113.000

5 VOCs 19 Propane 0.003 0.008 0.000 0.140 113.000

8 SHH 20 Gasoline 0.000 0.090 0.000 0.140 162.000

7 Other 2 21 Coking Coal 0.720 0.005 2.500 0.950 208.000

8 Other 3 22 steam Coal 0.720 0.005 2.500 0.950 208.000

9 Other 4 23 EJectrlclly 0.400 0.004 1.450 0.550 134.000

Combustion Rell/ted 24 Other 1

;::; 10 Particulates 0 0 0 CD 11 VOCs 0 0 0 Electrlclly use expressed !!IS primary equivalent (10,500 Btu/kWh)

12 Sulfur Dioxides 1 0 0 13 Nitrogen OxIdes 0 0 0 14 Carbon Dioxide 57 3i1 1B

1.5 TOTAL 330.8 195.7 135.1

SHH • Sold, hyttocmrbon/orgonlc, regulated under hazardous.

.... N \0

2

3

4

Shoe! E

Flnancla' Worlcsheof

Unit Technology Inputs

Discount rate: Equlpment IlfeHme (yra.): InlHal capital Investment

Annual cosl!II:

10% 21

$12,200 ($4,3711,

5

8

7

8

• 10 11 12 13 14

15 18

5130198

Oewlopment of Asphalts & Pavements Using Recycled Tire Rubber J User's Unit Summary Financial Results

Annual energy Income: $262 Annual net Income: $4,641

Total Ufe Cycle Cost $12,200 Total Ufe Cycle Benent $40,135

Net Present Value: $27,935 BeneHl-Cost RaHo: 3.29

Internal Rate of Return: 37.99% Rate of Return: 38.04%

Uniform Capital Recovery Factor: 0.1156 Levellzed Cost of Energy (per mil. Btu): -$17.36

Annual Production Cost Savings: $3,230 Dlacounted Payback Period: 3.23

~ coet Input ... 1994$

.... w o

1 2 S 4 5 6

Sheet F

Marlee' Penetration Worle_heef Development of Asphalts & Pavements Using Recycled Tire

Inputs

Hurdle ratalRR (%1: Voo, of introduction:

Number of unh 01 introduction: Total potonllol morlmt (/I unhl:

Maldmum morlmt penobollon (_I: ",umber of Y""'" ot morlmt ooturollon:

-~.;

26% 1997 GGOO

2,800,800.00 0.33

10

25 211

Number of Units In Opemtlon

Market Penetration

Internol Rol. of Return: Marlmt .hora oI Introduction:

~ r---~---------------------------------------------------------------'

eooooo .a. __ ._ •. _M" ____ '"

500000 -1----.--------------------- ----_._-----------,,;1".------_._---------_ .. _ .. _._-----------

400000 ---.----.--.------- -_. ---------/

300000 -1---------------

200000 ..J-._._. ____ . __ .... _. __ . ________ . ___ . _____ . __ ...........

100000 -~----------.-----.-------.--.-------------------------_._------------_ .. __ ._------_.

o 'DOS 2IIDO .... ""'0 "",. 202tI 202'

Ve ...

38% 1%

5I3JI96

5/30196

Sheet G

Maricet Penetration Results Development of Asphalts /I. Pavements Using Recycled TIre R

Year Units In Energy Savings Wasle Reduction Prod. Cost Savings Operation million Btulyear tonslyear JPfeatl

1 2 ~= - - - -- - - -3 1997 5500 940,500 743,275 17,765,068 4 1998 21847 3,735,837 2,952,425 70,566,082 5 1999 28822 4,9211,562 3,895,033 93,095,419 B 2000 37892 11,479,532 5,120,781 122,391,632 7 2001 49594 11,480,574 8,702,1111 160,189,237 8 2002 84540 11,038,340 11,721,999 208,465,003 9 2003 113379 14,257,1109 11,267,9111 269,315,208 10 2OD4 108743 111,253,053 14,425,352 344,781,218 ....

'" .... 11 12

2005 135134 23,107,914 18,282,139 436,484,502 2005 1887911 28,884,456 22,811,524 545,219,841

13 2007 207568 35,494,128 28,050,939 670,447,223 14 20DB 250753 42,1178,763 33,1187,002 809,935,310 15 2009 297100 50,1104,100 40,150,390 959,636,697 18 2010 3448911 58,977,5511 48,809,1148 1,114,024,832 17 2011 392210 87,087,910 53,003,637 1,266,843,181 18 2012 437178 74,757,0911 59,080,395 1.412,083,920 19 2013 478291 111,787,781 84,636,708 1,544,885,882 20 2014 514578 87,992,839 69,540,568 1,662,093,344 21 2015 545615 93,300,185 73,734,939 1,762,343,240 22 2018 571460 97,719,BBD 77,227,854 1,845,822,911 23 2017 592503 101,318,013 80,071,428 1,913,792,063 24 2018 809327 104,194,917 82,345,037 1,988,133,793 25 2019 822582 108,481,522 84,139,331 2,010,947,608 2B 2020 632908 108,228,926 85,531,528 2,044,294,256 27 2021 840873 109,589,283 86,608,194 2,070,027,765 2B 2022 846980 .110,633,580 87,433,500 2,089,753,451 29 2023 851636 111,429,758 88,062,718 2,104,792,399 30 2024 855172 112,034,412 88,540,575 2,118,213,713 31 2025 857848 112,492,005 88,902,212 2,124,857,226

1 2 3,

'~

5 'II 1 D

• t:; . 10

'" 11 12 13 14 15 IS

Shoot H

Tof8IllEnergy Savin".

Number of

Year Units In DIstillate

OpermtJon 011

1990 · · 1995 · · :roOD ,

37,892 · 2005 135,134 ·

'2010 344,898 · 2015 545,815 · '2020 832,908 · 2025 657,848 .- · -- -, " .

,

Number of Vel!lr StMmCoaI Units In

. Oll8l'l!ltlon 1990 · · 1995 · · 2000 37,892 !: · 2005 135,134 . · 2010 344,898 " · 2015 545,615 u · 2020 832,908 r, · 2025 657.848 • t ~ · .

5130196

Oevatopmerd of Alpha .. & Pavement. Using Recycled Tire Rubber

Energy SlIvlnglll by Fuel Type (million Btul!l, I

Residual 011 Natural Oms Propmne Omsollne Coking Coal ,

· · · · .

· · · · . · ·

,

· 6,479,532 · " · · · 23,107,914 ~ · , '. · 56,977,556

· · ; ". · · 93,300,165

· ,. , · · 106,228,926 .. · · , · · 112,492,006

Electricity otftsr Total Energy Sl!Ivlngs

mlmonSt • fiN.

· · · · · · · · · · 11,479,532 9,913,684

· · 23,107,914 35,355,106

· · 56,977,556 9O,235,1!64

· · 93,300,165 142,749,252

· · 106,228,926 165,567,197

· · 112,492,006 In,112,772

1 2 3

• 5 6 7 8

e I. 1

..... 12 ~1

• • 18

Shoe! I Total Waste Reduction o.volopmenl oJ Aspholb & _em. Using Rocyclod TIro Rubbor

Waste ReducUon by Waste Type (tons) .. III lit lit • NOrt-Combustlon Related .........

Num ...... '" Non-hazardous Hazardous Units In (RCRA) Toxic (TRI) (non-TRI) CFCs VOCs ISHH 0111 ... 2 0111 ... 3

Va ... Operation

1990 - - - - - - - -1995 - - - - - - - -2000 37,892 4,433,384 I": - - - - - -2005 135,13.4 15,810,878 - - - - - -2010 344,898 4O,353,oee - - - - - -2015 545,615 83,835,655 " - - - - - -c 2020

~= 74,~~ - - - - - -2025 657 78968 18 - - - - - -

Wasta Reduction by Waste Typo (tons) •• ," , • • CombustIOn Related ... ,. • flo TOTAL

Num ...... '" Sulfur Nitrogen Cl!!tbon WASTE Units In PlI!I'IIcuIates i VOCs ' ,DIoxides Oxides DIoxide REOUCTlON

Va ... OperaUon . :';

" (tons) 1990 - - - - - - -1995 - - - - - - -2000 37,892 2,333 16 8,099 3,078 673,871 5,120,761 2005 135,13.4 8,319 65 26,_ 10,976 2,403,223 16,262,139 2010 344,898 21,232 ,147 ,73,722 26,014 8,133,688 49,609,040 2015 545,615 33,_ 233 116,1125 44,318 8,703,217 73,734,938 2020 832,906 38,862 '271 135,284 51,406 1:~:eoo ~:~526 2025 657,848 ~,~1_ 261 ' 14iii15 53 43.4 11 169 65 12

,.-----

5130196

OII1er 4

- -- -- -- -- -- -- -- -