Sensitivity Analysis Of Aashto's 2002 Flexible And Rigid

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Sensitivity Analysis Of Aashto's 2002 Flexible And Rigid Pavement Sensitivity Analysis Of Aashto's 2002 Flexible And Rigid Pavement

Design Methods Design Methods

Sanjay Shahji University of Central Florida

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SENSITIVITY ANALYSIS OF AASHTO’S 2002 FLEXIBLE AND RIGID PAVEMENT DESIGN METHODS

by

SANJAY SHAHJI B.E. Mumbai University, 2002

A thesis submitted in partial fulfillment of the requirements for the degree of Master of Science

in the Department of Civil & Environmental Engineering in the College of Engineering and Computer Science

at the University of Central Florida Orlando, Florida

Spring Term 2006

ii

© 2006 Sanjay Shahji

iii

ABSTRACT

Over the years pavement design has been based on empirical equations developed from

the American Association of State Highway Transportation Officials (AASHTO) road tests. The

various editions of the AASHTO pavement design guide have served well for several decades;

nevertheless many serious limitations existed for their continued use as the nation’s primary

pavement design procedure. For example, the traffic loads and truck sizes have increased over

the years, the AASHTO design equations were derived based on the climatic conditions present

at the Road Tests site, and the issue of aging materials was not addressed in the design.

To overcome these limitations AASHTO finally proposed the AASHTO 2002 design

guide which is based on mechanistic – empirical approach and serves to address the

shortcomings and limitations of the earlier empirical design equations developed from the Road

Tests.

In this report, sensitivity analyses were conducted of the new AASHTO 2002 method for

both flexible and rigid pavements, to understand its performance with respect to the various

design parameters. Several important design parameters were selected and were varied one at a

time and their effect on the pavement distresses was found. The sensitivity analysis included

different amount of traffic loads, base materials, base material thicknesses, surface/slab layer

thicknesses and subgrade materials. Some of the illogical results obtained from the sensitivity

analyses were also addressed.

.

iv

.

ACKNOWLEDGMENTS

The writer wishes to express his sincere appreciation and gratitude to his major advisor,

Dr. Shiou-San Kuo, for his guidance and assistance during investigation and preparation of this

research report and for his constant inspiration throughout the graduate program. Special thanks

to the other members of the writer’s guidance committee – Dr. Manoj Chopra and Dr. Hesham

Mahgoub.

v

TABLE OF CONTENTS

LIST OF FIGURES ..................................................................................................................... viii

LIST OF TABLES....................................................................................................................... xiii

CHAPTER ONE: INTRODUCTION............................................................................................. 1

1.1 Problem Statement ................................................................................................................ 1

1.2 Thesis Organisation .............................................................................................................. 2

1.3 Objective ............................................................................................................................... 3

CHAPTER TWO: LITERATURE REVIEW................................................................................. 4

2.1 Introduction........................................................................................................................... 4

2.2 AASHTO Design Equations ................................................................................................. 5

2.2.1 Original AASHTO Design Equations for flexible pavements....................................... 6

2.2.2 Original AASHTO Design Equations for Rigid pavements .......................................... 8

2.3 Need for Mechanistic- Empirical Design ........................................................................... 10

2.4 2002 Mechanistic Empirical Design Models...................................................................... 11

2.4.1 Models for flexible pavement distresses...................................................................... 12

2.4.1.1 Permanent Deformation in Asphalt mixtures ....................................................... 12

2.4.1.2 Permanent Deformation in Unbound Materials ................................................... 14

2.4.1.3 Permanent Déformation of Total Pavement Structure ......................................... 17

2.4.1.4 Fatigue Cracking in Asphalt Mixtures.................................................................. 18

2.4.2 Models for Rigid Pavement Distresses ........................................................................ 21

2.4.2.1 JPCP Cracking Model .......................................................................................... 21

2.4.2.2 JPCP Faulting Model ........................................................................................... 22

2.4.2.3 CRCP Punchout Model......................................................................................... 24

vi

CHAPTER THREE: AASHTO 2002 DESIGN METHODOLOGY ........................................... 27

3.1 Introduction......................................................................................................................... 27

3.2 Pavement Design Components ........................................................................................... 28

3.2.1 Design Inputs ............................................................................................................... 28

3.2.2 Processing of inputs over design analysis period ........................................................ 29

3.2.3 Pavement Response Model .......................................................................................... 30

3.2.4 Incremental Distress and Damage accumulation......................................................... 30

3.2.5 Distress Prediction ....................................................................................................... 31

3.2.5.1 International Roughness Index (IRI) ................................................................... 31

3.2.5.2 Bottom-up Fatigue cracking or Alligator cracking .............................................. 32

3.2.5.3 Surface-down fatigue cracking or Longitudinal Cracking ................................... 33

3.2.5.4 Thermal Cracking ................................................................................................. 34

3.2.5.5 Permanent Deformation........................................................................................ 34

3.2.5.6 Joint Faulting for JPCP........................................................................................ 35

3.2.5.7 Transverse Slab Cracking in JPCP ...................................................................... 35

3.2.5.8 Punchouts in CRCP .............................................................................................. 36

3.2.6 Design Reliability: ....................................................................................................... 36

CHAPTER FOUR: RESULTS OF SENSITIVITY ANALYSIS................................................. 37

4.1 Flexible Pavement Sensitivity Analysis.............................................................................. 37

4.2 Rigid Pavement Sensitivity Analysis................................................................................ 101

4.2.1 Jointed Plain Concrete Pavement (JPCP) .................................................................. 101

4.2.2 Continuous Reinforced Concrete Pavement (CRCP) ................................................ 135

CHAPTER FIVE: COMPARISON OF METHODS.................................................................. 152

vii

CHAPTER SIX: SUMMARY OF RESULT AND CONCLUSION ......................................... 156

6.1 Flexible Pavements ........................................................................................................... 156

6.1.1 Tabulated Results....................................................................................................... 156

6.1.2 Conclusions on Flexible Pavement............................................................................ 159

6.2 Rigid Pavements ............................................................................................................... 162

6.2.1 Tabulated Results (Jointed Plain Concrete Pavement) .............................................. 162

6.2.2 Conclusions on Jointed Plain Concrete Pavement (JPCP) ........................................ 165

6.2.3 Tabulated Results (Continuous Reinforced Concrete Pavement).............................. 166

6.2.4 Conclusions on Continuous Reinforced Concrete Pavement (CRCP) ...................... 167

APPENDIX: AASHTO 2002 SOFTWARE OUTPUT FOR FLEXIBLE PAVEMENT

EXAMPLE.................................................................................................................................. 169

LIST OF REFERENCES............................................................................................................ 210

viii

LIST OF FIGURES

Figure 1: Terminal IRI vs AADTT............................................................................................... 42

Figure 2: AC surface down cracking vs AADTT ......................................................................... 43

Figure 3: AC bottom up cracking vs AADTT .............................................................................. 44

Figure 4: AC Thermal Fracture vs AADTT ................................................................................. 45

Figure 5: Permanent Deformation (AC only) vs AADTT............................................................ 46

Figure 6: Permanent Deformation (Total Pavement) vs AADTT ................................................ 47

Figure 7: Permanent Deformation in different pavement layers over the design life................... 48

Figure 8: Terminal IRI vs AC Layer Thickness .......................................................................... 49

Figure 9: AC Surface down cracking vs AC Layer Thickness..................................................... 50

Figure 10: AC bottom up cracking vs AC layer thickness ........................................................... 51

Figure 11: AC thermal fracture vs Asphalt Layer thickness......................................................... 52

Figure 12: Permanent Deformation (AC only) vs Asphalt Layer Thickness................................ 53

Figure 13: Permanent Deformation (Total Pavement) vs AC layer thickness.............................. 54

Figure 14: Terminal IRI vs Base layer thickness.......................................................................... 55

Figure 15: AC surface down cracking vs Base layer thickness .................................................... 56

Figure 16: AC bottom up cracking vs Base layer thickness ......................................................... 57

Figure 17: AC thermal fracture vs Base layer thickness............................................................... 58

Figure 18: Permanent Deformation (AC only) vs Base layer thickness....................................... 59

Figure 19: Permanent deformation (total) pavement vs Base Layer thickness ............................ 60

Figure 20: Terminal IRI vs Base layer modulus........................................................................... 61

Figure 21: AC surface down cracking vs Base layer modulus ..................................................... 62

ix

Figure 22:AC bottom up cracking vs Base layer modulus ........................................................... 63

Figure 23: AC thermal fracture vs Base layer modulus................................................................ 64

Figure 24: Permanent Deformation (AC only) vs Base layer modulus ........................................ 65

Figure 25: Permanent deformation (Total Pavement) vs Base layer modulus ............................. 66

Figure 26: Terminal IRI vs Subbase thickness ............................................................................. 67

Figure 27: AC surface down cracking vs Subbase layer thickness .............................................. 68

Figure 28:AC bottom up cracking vs Subbase layer thickness..................................................... 69

Figure 29:AC thermal fracture vs Subbase layer thickness .......................................................... 70

Figure 30: Permanent deformation (AC only) vs Subbase layer thickness .................................. 71

Figure 31: Permanent deformation (Total Pavement) vs Subbase layer thickness....................... 72

Figure 32: Terminal IRI vs Subbase layer modulus ..................................................................... 73

Figure 33: AC surface down cracking vs Subbase layer modulus................................................ 74

Figure 34: AC bottom up cracking vs Subbase layer modulus..................................................... 76

Figure 35: AC thermal fracture vs Subbase layer thickness ......................................................... 77

Figure 36: Permanent deformation (AC only) vs Subbase layer Modulus................................... 78

Figure 37: Permanent deformation (Total Pavement) vs Subbase layer thickness....................... 79

Figure 38: Terminal IRI vs Subgrade modulus............................................................................. 80

Figure 39: AC surface down cracking vs Subgrade Modulus ...................................................... 81

Figure 40: AC bottom up cracking vs Subgrade modulus............................................................ 82

Figure 41: AC thermal fracture vs Subgrade modulus ................................................................. 83

Figure 42: Permanent deformation (AC only) vs Subgrade modulus........................................... 84

Figure 43: Permanent deformation vs Subgrade modulus........................................................... 85

Figure 44: Sensitivity of Total pavement rutting to Asphalt layer thickeness.............................. 86

x

Figure 45: Sensitivity of Total Pavement Rutting with Base thickness........................................ 87

Figure 46: Sensitivity of total pavement rutting with the subbase thickness................................ 88

Figure 47: Sensitivity of Terminal IRI with AC layer thickness .................................................. 89

Figure 48: Sensitivity of Surface down cracking with Asphalt layer thickness ........................... 90

Figure 49: Sensitivity of Bottom up cracking vs Asphalt thickness............................................. 91

Figure 50: Sensitivity of AC layer rutting with AC layer thickness............................................. 92

Figure 51: Sensitivity of Terminal IRI with base layer thickness ................................................ 93

Figure 52: Sensitivity of Bottom up cracking with base layer thickness...................................... 94

Figure 53: Sensitivity of AC rut with base layer thickness .......................................................... 95

Figure 54: Terminal IRI vs AC layer thickness ( for Subgrade Modulus of 5k psi and 10k psi). 96

Figure 55: AC surface down cracking vs AC layer thickness ( for subgrade modulus of 5k and

10k psi).................................................................................................................................. 97

Figure 56: AC bottom up cracking vs AC layer thickness ( for subgrade modulus of 5k and 10k

psi)......................................................................................................................................... 98

Figure 57: Permanent deformation (AC only) vs AC layer thickness ( for subgrade modululs of

5k and 10k psi)...................................................................................................................... 99

Figure 58: Perm. Deformation (Total Pavement) vs AC layer thickness ( for subgrade modulus

of 5k and 10k psi) ............................................................................................................... 100

Figure 59: Sensitivity of Terminal IRI with AADTT................................................................. 105

Figure 60: Sensitivity of Transverse Cracking with AADTT..................................................... 106

Figure 61: Sensitivity of Mean Joint Faulting with AADTT...................................................... 107

Figure 62: Sensitivity of Terminal IRI with Slab thickness ....................................................... 108

Figure 63: Sensitivity of Transverse Cracking with Slab Thickness.......................................... 109

xi

Figure 64: Sensitivity of Mean Joint Faulting with Slab Thickness........................................... 110

Figure 65: Sensitivity of Terminal IRI with Joint Spacing......................................................... 111

Figure 66: Sensitivity of Transverse Cracking with Joint Spacing............................................. 112

Figure 67: Sensitivity of Mean Joint Faulting with Joint Spacing.............................................. 113

Figure 68: Sensitivity of Terminal IRI with Dowel Bar Spacing ............................................... 114

Figure 69: Sensitivity of Transverse Cracking with Dowel Bar Spacing................................... 115

Figure 70: Sensitivity of Mean Joint Faulting with Dowel Bar Spacing.................................... 116

Figure 71: Sensitivity of Terminal IRI with Dowel Bar Diameter ............................................. 117

Figure 72: Sensitivity of Transverse Cracking with Dowel Bar Diameter................................. 118

Figure 73: Sensitivity of Mean Joint Faulting with Dowel Bar Diameter.................................. 119

Figure 74: Sensitivity of Terminal IRI with layer 2 (Cement Stabilized base) thickness .......... 120

Figure 75: Sensitivity of Transverse Cracking with Layer – 2 (Cement Stabilized) thickness.. 121

Figure 76: Sensitivity of Mean Joint Faulting with Layer 2 (Cement Stabilized) thickness...... 122

Figure 77: Sensitivity of Terminal IRI with Layer 3 (Crushed Stone Subbase) thickness......... 123

Figure 78: Sensitivity of Transverse Cracking with Layer 3 (subbase layer) thickness............. 124

Figure 79: Sensitivity of Mean Joint Faulting with Layer 3 (Crushed Stone) thickness............ 125

Figure 80: Sensitivity of Terminal IRI with Subgrade Modulus ................................................ 126

Figure 81: Sensitivity of Transverse Cracking with Subgrade Modulus.................................... 127

Figure 82: Sensitivity of Mean Joint Faulting with Subgrade .................................................... 128

Figure 83: Effect of Tied/Untied PCC shoulder on Terminal IRI .............................................. 129

Figure 84: Effect of Tied/Untied PCC shoulder on Transverse Cracking .................................. 130

Figure 85: Effect of Tied/Untied PCC shoulder on Mean Joint Faulting ................................... 131

Figure 86: Sensitivity of Terminal IRI with Base Modulus ....................................................... 132

xii

Figure 87: Sensitivity of Transverse Cracking with Base layer modulus................................... 133

Figure 88: Sensitivity of Mean Joint Faulting with Base layer modulus.................................... 134

Figure 89: Sensitivity of Terminal IRI with AADTT................................................................. 138

Figure 90: Sensitivity of Punchouts with AADTT ..................................................................... 139

Figure 91: Sensitivity of Terminal IRI with Slab Thickness ...................................................... 140

Figure 92: Sensitivity of Punchouts with Slab Thickness .......................................................... 141

Figure 93: Sensitivity of Terminal IRI with Base Layer Thickness ........................................... 142

Figure 94: Sensitivity of Punchouts with Base layer thickness .................................................. 143

Figure 95: Sensitivity of Terminal IRI with Compacted Subgrade layer thickness ................... 144

Figure 96: Sensitivity of Punchouts with Compacted Subgrade Thickness ............................... 145

Figure 97: Sensitivity of Terminal IRI with Percent Steel ......................................................... 146

Figure 98: Sensitivity of Punchouts with Percent Steel.............................................................. 147

Figure 99: Sensitivity of Terminal IRI with Steel Depth............................................................ 148

Figure 100: Sensitivity of Punchouts with Steel Depth ............................................................. 149

Figure 101: Sensitivity of Terminal IRI with Uncompacted Subgrade Modulus...................... 150

Figure 102: Sensitivity of CRCP Punchouts with Subgrade Modulus ....................................... 151

Figure 103: Flexible Pavement Design Example........................................................................ 152

xiii

LIST OF TABLES

Table 1 Truck Traffic Classification 1 based on LTPP traffic data.............................................. 38

Table 2: The average axle spacing for tandem, tridem and quad axles ........................................ 39

Table 3: List of the parameters used in the sensitivity analyses of Flexible pavement ................ 41

Table 4: List of parameters used for sensitivity analyses of JPCP pavement............................. 103

Table 5: List of parameters used in the sensitivity analyses of CRCP pavement....................... 137

Table 6: Percent Change in Pavement Distresses for changes in AADTT................................. 156

Table 7: Percent Change in Pavement Distresses for changes in AC layer thickness................ 156

Table 8: Percent Change in Pavement Distresses for changes in Base Layer thickness ............ 157

Table 9: Percent Change in Pavement Distress for changes in Base Layer Modulus ................ 157

Table 10: Percent Change in Pavement Distress for change in Subbase Layer Thickness ........ 157

Table 11: Percent Change in Pavement Distress for change in Subbase Layer Modulus .......... 158

Table 12: Percent Change in Pavement Distress for change in Subgrade Modulus................... 158

Table 13: Sensitivity Analysis of Pavement Distresses Versus Pavement Design Parameters.. 159

Table 14: Percentage change in JPCP pavement distresses for change in AADTT ................... 162

Table 15: Percent change in JPCP pavement distresses for change in Slab thickness ............... 162

Table 16: Percent change in JPCP pavement distresses for change in Joint Spacing................. 163

Table 17: Percentage change in JPCP pavement distresses for change in Dowel bar diameter . 163

Table 18: Percent Change in JPCP pavement distresses for change in Dowel Bar Spacing ...... 163

Table 19: Percentage change in JPCP pavement distresses for change in Layer – 2 thickness . 163

Table 20: Percentage change in JPCP pavement distresses for change in Layer – 3 thickness . 163

Table 21: Percent Change in JPCP pavement distresses for change in layer 4 Modulus ........... 164

xiv

Table 22: Percentage change in JPCP pavement distresses for Tied/Untied PCC Shoulder...... 164

Table 23: Percentage change in JPCP pavement distresses for change in Base Modulus.......... 164

Table 24: Sensitivity of pavement distresses with change in JPCP pavement design parameters

............................................................................................................................................. 164

Table 25: Percentage change in CRCP pavement distresses for change in AADTT.................. 166

Table 26: Percentage change in CRCP pavement distresses for change in Slab Thickness....... 166

Table 27: Percentage change in CRCP pavement distresses for change in Base Layer Thickness

............................................................................................................................................. 166

Table 28: Percentage change in CRCP pavement distresses for change in Compacted Subgrade

............................................................................................................................................. 166

Table 29: Percentage change in CRCP pavement distresses for change in Percent Steel .......... 167

Table 30: Percentage change in CRCP pavement distresses for change in Steel Depth ............ 167

Table 31: Percentage change in CRCP pavement distresses for change in Uncompacted Subgrade

Modulus .............................................................................................................................. 167

Table 32: Sensitivity of pavement distresses with changes in CRCP pavement design parameters

............................................................................................................................................. 167

1

CHAPTER ONE: INTRODUCTION

1.1 Problem Statement

Earliest years pavement design solely depended on rule-of-thumb procedures based on

past experiences. The same thickness was designed for a section of highway even though widely

different soils were encountered. From 1920’s to 1940’s engineers made efforts to evaluate the

structural properties of soil and correlations were established relating the pavement performance

with the subgrade types. In the early 1950’s gear loads imposed by heavy aircrafts and the

increased truck traffic necessitated a more rational approach towards the design of pavements.

This resulted in the construction of several test roads for the purpose of evaluating the effect of

load and materials on pavement design. The Bureau of Public Roads and AASHO as well as

many state highway departments have been responsible for several test roads constructed in the

United States. These road tests yielded pavement design formulas for the Interstate Highway

System that were based on observations of the performance of pavement test sections.

With the availability of computers, high speed and memory it was possible to do complex

calculations and operations in quick time. This resulted in the development of computer

programs and applications for the design of pavements in a more mechanistic way. But theory

alone had not proven sufficient to design pavements realistically and there was still a need to rely

on observed performance. Therefore, efforts were made to design the pavements in a mechanistic

– empirical way to realistically predict pavement responses. The AASHTO Joint force on

Pavements in cooperation with National Cooperative Highway Research Program (NCHRP) and

Federal Highway Authority (FHWA) sponsored the “Workshop on Pavement Design” in March

2

1996 at Irvine California. At the workshop many of the top pavement engineers were charged

with identifying the means for developing an AASHTO mechanistic empirical pavement design

procedure by 2002. Based on the conclusions developed at the March 1996 meeting the

Development of the 2002 guide for Design of New and Rehabilitated Pavement Structures was

awarded to ERES Consultants Division of Applied Research and Associates Inc. in February

1998.

This resulted in the development of the new AASHTO 2002 design guide that utilizes

existing mechanistic-based models and databases reflecting current state of the art pavement

design procedures. A mechanistic- empirical design approach relates an input such as a wheel

load to an output or pavement response, such as a stress or strain. The responses are used to

predict distress based on laboratory test and field performance data. This was the first pavement

design procedure that incorporated both the impact of climate and aging on materials properties

in an iterative and comprehensive manner throughout the entire design life. However, prior to the

use of this guide in practice it is necessary to investigate and evaluate the pavement response

models incorporated in the design guide. This is required so that design guide yields realistic

pavement responses for the design inputs.

1.2 Thesis Organization

The thesis is organized into six chapters. Chapter 2 includes the literature review related

to the various pavement response models for the new AASHTO 2002 design guide. It also

includes the design equations used in the earlier AASHTO design guides.

3

Chapter 3 includes a very brief summary of the new AASHTO design methodology. It

discusses in general the steps involved in the mechanistic empirical design approach for both

flexible and rigid pavement designs.

Chapter 4 presents the sensitivity analysis of AASHTO 2002 design guide for both

flexible and rigid pavements. It includes various design parameters including traffic loads,

thicknesses and moduli of pavement components. Chapter 5 presents a design example solved

using earlier AASHTO design methods and new AASHTO 2002 design guide, and Chapter 6

presents the results and the conclusions of this research study.

1.3 Objective

The report aims at understanding the new AASHTO 2002 pavement design guide by

conducting a sensitivity analysis of its mechanistic-empirical design approach for both flexible

and rigid pavements. In order to achieve this objective, major pavement distresses were selected

and their sensitivity with respect to the design parameters for both flexible and rigid pavement

design methods was found. This was done to understand the pavement response models to

changes in various design parameters including traffic, layer properties etc. and to check if the

pavement response models yielded realistic responses to changes in the design inputs.

4

CHAPTER TWO: LITERATURE REVIEW

Literature review was conducted through information search using electronic databases

and documented publications. This chapter clearly distinguishes the theories and approaches

between the old various (1960 – 1993) design guides and the new 2002 design method.

2.1 Introduction

Over the past years, empiricism had played a significant role in the design of road

pavements. The thickness of road pavements was based purely on experience. The same

thickness was used for pavement design along a highway despite encountering different types of

soils along the length of the highway. As experience was gained over a period of years in

pavement design, various methods were adopted by different agencies for determining the

thickness of pavement under different conditions.

From 1958 to 1960 American Association of State Highway Officials (AASHO)

sponsored the full-scale road test in Ottawa, Illinois, which yielded pavement design formulas

for the Interstate highway system that were based on observations of the performance of

pavement test sections. Tests were conducted to determine the effects of a wide range of design

factors. Test sections were subjected to thousands of load repetitions before being taken out of

the test; surviving test sections received more than a million load applications. The most

significant road test finding was that pavement damage was related to the accumulation of axle

repetitions of all types, even if ultimate strength of the pavement was not exceeded by any one

axle load. In other words, even though the load of an axle passing the pavement was less than the

ultimate strength of the pavement, damage to the pavement will still occur on account of the

5

repetition of axle load of all types through the pavement. Furthermore the road tests

demonstrated that the damage caused by heavier loads is exponentially greater than damage

caused by lighter loads.

One of the key products of the road test was the concept of load equivalency, which

accounts for the effects of the axle loads on pavements in terms of an equivalent single axle load

(ESAL). Under this concept the damage imposed by any vehicle is based on its axle weights

compared with a standard 18,000 lb axle load. The ESAL values for other axles express their

relative effect on pavement wear. If the number and types of vehicles using the pavement can be

predicted, then engineers can design the pavement for anticipated number of 18 kips equivalent

single axle loads (18 kips ESAL). Virtually, all heavy-duty pavements built in the United States

since the mid-1960s have been designed using the principles and formulas developed from the

Road Test.

The adoption of 20 year design life as the standard for the Interstate system enabled the

state highway agencies to design the Interstate Highway Pavements to the same service criteria.

On the basis of the information available at that time 20 years was considered a reasonable

length of service for such a major highway network and was about as far into the future as

designers wished to project traffic growth or extrapolate the road test findings. However, many

pavements did not endure 20 years design life and had to undergo some rehabilitation.

2.2 AASHTO Design Equations

The empirical design equations developed from the AASHO road tests are discussed in

the following sections (Reference: Pavement Analysis and Design, Yuang H Huang (1)):

6

2.2.1 Original AASHTO Design Equations for flexible pavements

The basic equations developed form the AASHO road test for flexible pavements are

given by

Gt β log Wt( ) log ρ( )−( ) (2.1)

β 0.400.081 L1 L2+( )

SN 1+( )5.19 L23.23⋅

+

(2.2)

log ρ( ) 5.93 9.36 log SN 1+( )⋅+ 4.79 log L1 L2+( )⋅− 4.33 log L2( )⋅+ (2.3)

where,

Gt = logarithm of the ratio of loss in serviceability at time‘t’ to the potential loss taken at a point

when the terminal serviceability pt is 1.5, or Gt = log [(4.2- pt)/ (4.2-1.5)], noting that 4.2 is the

initial serviceability for flexible pavements.

β = a function of design and load variables that influences the shape of p versus Wt curve.

ρ = a function of design and load variables that denotes the expected number of load applications

to a pt equal to 1.5, while ρ = Wt when pt = 1.5.

Wt = axle load application at the end of time t.

pt = serviceability at the end of service time t.

L1 = load on one single axle or a set of tandem axles, in kip.

L2 = axle load, 1 for single axle and 2 for tandem axle.

SN = structural number of pavement system, which is computed as;

SN = a1D1 + a2D2 + a3D3

7

in which a1, a2 and a3 are layer coefficients for the surface, base and subbase, respectively; and

D1, D2 and D3 are the thicknesses of the surface, base, and subbase respectively. The procedure is

greatly simplified if an equivalent 18 kip (80-kN) single-axle load is used. By setting L1 = 18 and

L2 = 1 the following equation is obtained as:

log Wt18( ) 9.36 log SN 1+( )⋅ 0.20−

log4.2 pt−

4.2 1.5−

⎛⎜⎝

⎞⎟⎠

0.41094

SN 1+( )5.19+

+

(2.4)

in which Wt18 is the number of 18-kip single axle load application to time t and pt is the terminal

serviceability index. The above equation is applicable only to flexible pavements in the AASHO

road test with an effective subgrade modulus of 3000 psi.

For other subgrade and environmental conditions, the equation (2.4) is modified to

log Wt18( ) 9.36 log SN 1+( )⋅ 0.20−

log4.2 pt−

4.2 1.5−

⎛⎜⎝

⎞⎟⎠

0.41094

SN 1+( )5.19+

+ 2.32 log MR( )⋅+ 8.07−

(2.5)

in which MR is the effective roadbed soil resilient modulus.

To take local precipitation and drainage conditions into account, the equation of structural

number was modified to

SN = a1D1 + a2D2m2 + a3D3m3 (2.6)

in which m2 is the drainage coefficient of base course and m3 is the drainage coefficient of

subbase course.

The modified equation is the performance equation which gives the allowable number of

18-kip single-axle load applications Wt18 to cause the reduction of PSI to pt. If the predicted

number of applications W18 is equal to Wt18 the reliability of design is only 50% because all

8

variables in the equation are based on mean values. To achieve a higher level of reliability, W18

must be smaller than Wt18 by a normal deviate ZR as:

ZRlog W18( ) log Wt18( )−

So (2.7)

in which, ZR is the normal deviate for a given reliability R, and So is the standard deviation.

Combining these two equations and replacing (4.2 - pt) by ΔPSI, equation (2.5) yields

log Wt18( ) ZR So⋅ 9.36 log SN 1+( )⋅+ 0.20−

logΔPSI

4.2 1.5−⎛⎜⎝

⎞⎟⎠

0.41094

SN 1+( )5.19+

+ 2.32 log MR( )⋅+ 8.07−

(2.8)

This is the final equation used for flexible pavement design or analysis.

2.2.2 Original AASHTO Design Equations for Rigid pavements

The basic equations developed from the AASHO road test for rigid pavements are given

by

Gt β log Wt( ) log ρ( )−( ) (2.9)

β 1003.63 L1 L2+( )5.2

D 1+( )8.46 L23.52⋅

+

(2.10)

log ρ( ) 5.85 7.35 log D 1+( )⋅+ 4.62 log L1 L2+( )⋅− 3.28 log L2( )⋅+ (2.11)

Gt = log[(4.5- pt)/(4.5-1.5)], where 4.5 is the initial serviceability and 1.5 is terminal

serviceability for rigid pavement at the AASHO Road Test, and pt is the serviceability at time t.

D = slab thickness in inches.

9

Using an equivalent 18 kip single axle load with L1 = 18 and L2 = 1 and combining Equations

(2.9) through (2.11) it yields,

log Wt18( ) 7.35 log D 1+( )⋅ 0.06−

log4.5 pt−

4.5 1.5−

⎛⎜⎝

⎞⎟⎠

11.624 107⋅

D 1+( )8.46+

+

(2.12)

In order to account for conditions other than those that existed in the road test, the above

equation was modified using experience and theory. The modified equation is given as:

log Wt18( ) ZR So⋅ 7.35 log D 1+( )⋅+ 0.06−

logΔPSI

4.5 1.5−⎛⎜⎝

⎞⎟⎠

11.624 107⋅

D 1+( )8.46+

+ 4.22 0.32pt−( ) logSc Cd⋅ D0.75 1.132−( )⋅⎡⎣ ⎤⎦

215.63 J⋅ D0.75 18.42

Eck

⎛⎜⎝

⎞⎟⎠

0.25−⎡⎢

⎢⎢⎣

⎤⎥⎥⎥⎦

⋅

⎡⎢⎢⎢⎢⎢⎣

⎤⎥⎥⎥⎥⎥⎦

⋅+

(2.13)

where,

Sc = Modulus of rupture of concrete

Ec = Modulus of elasticity of concrete

k = Modulus of subgrade reaction

J = load transfer coefficient

Cd = drainage coefficient

This is the final design equation for rigid pavements.

10

2.3 Need for Mechanistic- Empirical Design

Pavement design methods were constantly updated by the AASHTO through research

findings; thus, the most recent AASHTO 2002 design guide was developed based on mechanistic

- empirical design approach.

The system of highways designed using the earlier AASHTO Design Guide has matured.

Some have exceeded 20 years life and other may have been rehabilitated and reconstructed

before reaching the design life. Although those pavements performed well, the experience with

the interstate pavements has revealed some serious limitations to the design methods, such as

shortcoming in the quality of basic design inputs to the design process, problems with the

materials and construction control, and an inability to predict how well alternative rehabilitation

schemes.

The needs for and the benefits of a mechanistically based pavement design procedure

were clearly recognized and the AASHTO Joint Task Force on pavements, in cooperation with

NCHRP and FHWA, sponsored the workshop on pavement design in March 1996 at Irvine,

California. The workshop participants included many top pavement design engineers from

United States who were charged with identifying the means for developing an AASHTO

mechanistic-empirical design procedure by 2002. Based on the conclusions developed at the

March 1996 meeting, NCHRP Project 1-37A, Development of the 2002 Guide for the Design of

New and Rehabilitated Pavement Structures was awarded to ERES Consultants, division of

Applied Research Associates, Inc. in February 1998. The project called for the development of a

guide that utilized existing mechanistic based models and databases reflecting current state-of-

11

the-art design pavement design procedures. This guide addressed all new and rehabilitation

design issues and provided an equitable design basis for all pavement types.

2.4 2002 Mechanistic Empirical Design Models

This was the first pavement design procedure that incorporated both the impact of climate

and aging of materials properties in an iterative and comprehensive manner throughout the entire

design life. Most of the existing models have limited usage with equivalent or worst case

material properties being used as inputs. When varying material properties and climatic

conditions are applied using an incremental damage approach over the design period, some of

the models give erroneous results. As a result significant resources are required to modify and

adapt these models to work within the incremental damage approach. In addition, the hourly,

monthly and annual variations in traffic loadings are superimposed on changes to materials and

climate to more realistically reflect the ways in which pavements exist in-service.

The performance models (Reference: ERES. 2002 Design Guide (2)) that have been

incorporated in the AASHTO 2002 design guide are:

12

2.4.1 Models for flexible pavement distresses

2.4.1.1 Permanent Deformation in Asphalt mixtures

The constitutive relationship in this Guide to predict rutting in the asphalt mixtures is

based upon a field calibrated statistical analysis using laboratory repeated load permanent

deformation tests. This selected laboratory model is:

εpεr

a1 Ta2⋅ N

a3⋅

(2.14) where,

εp = Accumulated plastic strain at N repetitions of load (in/in)

εr = Resilient strain of the asphalt material as a function of mix properties, temperature and time

rate of loading (in/in)

N = Number of load repetitions

T = Temperature (deg F)

ai = Non-linear regression coefficients

While statistical relationships evaluated from laboratory repeated load tests on asphalt mixtures

were found to be reasonable; field calibration factors, βri, were necessary to ascertain the final

field distress model. The final asphalt rutting equation implemented in the Design Guide is thus

of the form:

εpεr

βr1 a1⋅ Ta2 β r2⋅

⋅ Na3 β r3⋅

⋅

(2.15)

13

This is a relatively simple equation to use in the implementation process. The final lab

expression that was initially selected for the field calibration / validation process was:

εpεr

10 3.15552− T1.734 N0.39937⋅

(2.16)

Where, the sample size, N = 3476 observations and R2 = 0.644

Se = 0.321, where Se = Standard error of estimate

Se/S

y = 0.597, where Sy = Standard deviation of the y scores

This model shown in equation (2.16) was based on extensive research work conducted by Ayers

(3), Leahy (4) and Kaloush (5) (NCHRP 9-19: “Superpave Models”). The national field

calibrated model used in the Design Guide was determined by numerical optimization and other

modes of comparison to result in national calibration factors of:

βr1

= 0.509

βr2

= 0.9

βr3

= 1.2

This results in the final model as:

εpεr

k1 10 3.4488−⋅ T1.5606 N0.479244⋅

(2.17)

A depth parameter “k1” in Equation (2.17) is introduced to provide as accurate a rut depth

prediction model as possible from the following equations:

k1 C1 C2 depth⋅+( ) 0.328196depth⋅ (2.18)

C1 0.1039− hac2⋅ 2.4868 hac⋅+ 17.342− (2.19)

14

C2 0.0172 hac2⋅ 1.7331 hac⋅− 27.428+ (2.20)

where,

k1

= function of total asphalt layers thickness (hac

, in) and depth (in) to computational point, to

correct for the confining pressure at different depths. Equation (2.17) is calibrated from the

sample size of 387 observations with

R2 = 0.648

Se = 0.063 in where, Se = Standard error of estimate

Se/S

y = 0.574, where Sy = Standard deviation of y scores

The rutting model for new pavement systems has been partially calibrated based on 88 LTPP

new sections located in 28 states. Time-series data were available for many of the sections,

making the total number of 387 field rutting observations.

2.4.1.2 Permanent Deformation in Unbound Materials

The initial model framework used to predict the permanent deformation in unbound

material layers was that proposed by Tseng and Lytton (6). The basic relationship is:

δa N( ) β1εο

εr

⎛⎜⎜⎝

⎞⎟⎟⎠

⋅ e

ρN

⎛⎜⎝

⎞⎟⎠

β

−⋅ εv⋅ h⋅

(2.21)

where,

δa = Permanent deformation for the layer/sublayer (in).

N = Number of traffic repetitions.

εo, β, and ρ = Material properties.

15

εr = Resilient strain imposed in laboratory test to obtain the above listed material properties, ε

o, β,

and ρ (in/in).

εv = Average vertical resilient strain in the layer/sublayer as obtained from the primary response

model (in /in)

h = Thickness of the layer/sublayer (in).

β1 = calibration factor for the unbound granular and subgrade materials

During the development process and field calibration studies, numerous modifications were

necessary to determine a final reasonable calibrated relationship. Changes leading to the

elimination of the stress term in the model, major simplifications to the “β” and “ρ” equations

and an eventual combination of all unbound granular and subgrade materials into one model

were accomplished. The modified models developed are:

log β( ) 0.61119− 0.017638Wc− (2.22)

logεο

εr

⎛⎜⎜⎝

⎞⎟⎟⎠

e ρ( )β a1⋅ Erb1⋅⎡

⎣⎤⎦ e

ρ

109⎛⎜⎝

⎞⎟⎠

β

a9⋅ Erb9⋅

⎡⎢⎢⎣

⎤⎥⎥⎦+

2 (2.23)

Co lna1 Er

b1⋅⎛⎝

⎞⎠

a9 Erb9⋅

⎡⎢⎢⎢⎣

⎤⎥⎥⎥⎦ (2.24)

ρ 109 Co

1 109⎛

⎝⎞⎠β

−⎡⎣

⎤⎦

⎡⎢⎢⎣

⎤⎥⎥⎦

1β

⋅

(2.25)

16

Wc 51.712Er

2555⎛⎜⎝

⎞⎟⎠

10.64

⎡⎢⎢⎢⎣

⎤⎥⎥⎥⎦

0.3586− GWT0.1192⋅

⋅

(2.26)

where,

Wc = Water content (%).

Er = Resilient modulus of the layer/sublayer (psi).

GWT = Ground water table depth (ft).

a1 = 0.15

b1 = 0.0

a9 = 20.0

b9 = 0.0

The final calibrated model for the unbound granular base is given by:

δa N( ) βGBεο

ε.r

⎛⎜⎜⎝

⎞⎟⎟⎠

⋅ e

ρN

⎛⎜⎝

⎞⎟⎠

β

−⋅ εv⋅ h⋅

(2.27)

with the national calibration factor of βGB

= 1.673 being determined, where the sample size N =

387 observations,

R2 = 0.677


Se/S

y = 0.524 where, Sy = Standard deviation of y scores

The final calibrated model for all subgrade soils is as follows:

17

δa N( ) βSG

εο

ε.r

⎛⎜⎜⎝

⎞⎟⎟⎠

⋅ e

ρN

⎛⎜⎝

⎞⎟⎠

β

−⋅ εv⋅ h⋅

(2.28)

with the national calibration factor of βSG

= 1.35 being determined.

R2 = 0.136

N = 387 observations


Se/Sy = 0.850 where, Sy = Standard deviation of the y scores

Both rutting models were calibrated based on 88 Long Term Pavement Performance

(LTPP) new sections located in 28 states. Time-series data were available for many of the

sections, making the total number of 387 field rutting observations. In addition, comparative

studies involving general comparisons of unbound rutting levels for AASHTO Design Guide

(current) pavement structures also, provided valuable insight into the final selection.

2.4.1.3 Permanent Deformation of Total Pavement Structure

The total rutting in the pavement structure is equal to the summation of the individual

layer permanent deformation for each season and to estimate the permanent deformation of each

individual sublayer, the system verifies the type of layer, applies the model corresponding to the

material type of the sublayer and computes the plastic strain accumulated at the end of each

subseason. The overall permanent deformation for a given subseason is the sum of the permanent

deformation for each individual layer and is mathematically expressed as:

18

RD

1

nsublayers

i

εpi hi⋅∑

= (2.29)

where,

RD = Pavement Permanent Deformation

nsublayers = Number of sublayers

εpi

= Total plastic strain in sublayer i

hi = Thickness of sublayer i

The Equation (2.29) for total rutting can also be expressed as:

RDTotal RDAC RDGB+ RDSG+ (2.30)

RDAC, RDGB and RDSG can be found from equations (2.17), (2.27) and (2.28) as discussed

earlier.

2.4.1.4 Fatigue Cracking in Asphalt Mixtures

The most commonly used model form to predict the number of load repetitions to fatigue

cracking is a function of the tensile strain and mix stiffness (modulus). Most of relationships

available have a common basic structure and are function of the stiffness of the mix and the

tensile strain. The commonly used mathematical relationship used for fatigue characterization is

given by:

Nf Ck11εt

⎛⎜⎝

⎞⎟⎠

k2

⋅1E

⎛⎜⎝

⎞⎟⎠

k3

⋅ βf1 k1⋅ εt( )β f2− k2⋅

⋅ E( )β f3− k3⋅

⋅

(2.31)

19

where,

Nf = number of repetitions to fatigue cracking.

εt = tensile strain at the critical location.

E = stiffness of the material.

k1, k

2, k

3 = laboratory regression coefficients.

βf1

, βf2

, βf3

= calibration parameters.

C = laboratory to field adjustment factor.

The national field calibrated model used in the Design Guide was determined by numerical

optimization and other modes of comparison to result in national calibration factors of:

β f1

= k1* β’

f1

β’f1

= 1.0 β

f2 = 1.2

βf3

= 1.5 This results in the following final model as:

Nf 0.00432 k1⋅ C⋅1εt

⎛⎜⎝

⎞⎟⎠

3.9492⋅

1E

⎛⎜⎝

⎞⎟⎠

1.281⋅

(2.32)

Equation (2.32) has the parameter “k” being introduced to provide a correction for different

asphalt layer thickness (hac

) effects given by

a. For the bottom-up cracking :

k11

0.000398 0.003602

1 e11.02 3.49hac⋅−( )

+

+

(2.33) b. For the top-down cracking

20

k11

0.01 12.00

1 e15.676 2.8186hac⋅−( )

+

+

(2.34)

where,

hac

= Total thickness of the asphalt layers, in.

The final transfer function to calculate the fatigue cracking from the fatigue damage is expressed

as:

a. For bottom-up cracking (% of total lane area) :

(2.35) where,

FCbottom

= bottom-up fatigue cracking, percent lane area

D = bottom-up fatigue damage

C1 = 1.0

C1’

’= -2 * C2’

C2 = 1.0

C2’ = -2.40874 – 39.748 * (1 + hac)-2.856

Here,


Se = 6.2 percent

Se/Sy = 0.947

b. For top-down cracking (feet/mile);

21

(2.36)

where,

FCtop = top-down fatigue cracking, (ft/mile)

D = top-down fatigue damage, (ft/mile) Here, N = 414 observations S

e = 1242.25

Se/Sy = 0.977 The fatigue-cracking model for the asphalt concrete mixtures has been calibrated based on 82

LTPP sections located in 24 States

2.4.2 Models for Rigid Pavement Distresses

2.4.2.1 JPCP Cracking Model

The percentage of slabs with transverse cracks in a given traffic lane is used as a measure

of transverse cracking and is predicted using the following model for both bottom up and top

down crackings:

CRK1

1 FD 1.68−+ (2.37)

where,

CRK = predicted amount of top – down or bottom-up cracking (fraction)

22

FD = Calculated fatigue Damage

Model Statistics are:

R2 = 0.68


SEE = 5.4 percent

The total amount of cracking is determined as follows:

TCRACK CRKTop_down CRKBottom_up+ CRKTop_down CRKBottom_up⋅−( ) 100⋅ % (2.38)

where,

TCRACK = Total Cracking (percent)

CRKBottom_up = Predicted amount of Bottom Up cracking (Fraction)

CRKTop_down = Predicted amount of Top Down cracking (Fraction)

The JPCP transverse cracking model was calibrated based on performance of 196 field sections

located in 24 States.

2.4.2.2 JPCP Faulting Model

The faulting models for Rigid JPCP pavement is as follows p_

Faultm

1

m

i

ΔFaulti∑= (2.39)

ΔFaulti C34 FAULTMAXi 1− Faulti 1−−( )2⋅ DEi⋅ (2.40)

FAULTMAXi FAULTMAX0 C71

m

i

DEj∑=

⋅ log 1 C5 5.0EROD⋅+( )C6

⋅+

(2.41)

23

FAULTMAX0 C12 δcurling⋅ log 1 C5 5.0EROD⋅+( ) logP200 WetDays⋅

ps

⎛⎜⎝

⎞⎟⎠

⋅⎛⎜⎝

⎞⎟⎠

C6

⋅

(2.42)

where,

Faultm = mean joint faulting at the end of the month, in

ΔFaulti = incremental change (monthly) in mean transverse joint faulting during month i, in.

FAULTMAXi = Maximum Mean Transverse Joint Faulting for month i, in

FAULTMAXO = initial maximum mean transverse joint faulting, in

EROD = Base/Subbase erodibility factor

DEi = differential deformation energy accumulated during month i

δcurling = maximum mean monthly slab corner upward deflection PCC due to temperature curling

and moisture warping

Ps = overburden on subgrade, lb.

P200 = percent subgrade material passing #200 sieve

WetDays = average annual number of wet days (greater than 0.1 in of rainfall)

C1 through C8 and C12 and C34 are national calibration constants:

C12 C1 C2 FR0.25⋅+

C34 C3 C4 FR0.25⋅+

C1 1.29 C5 250

C2 1.1 C6 0.4

C3 0.001725 C7 1.2

C4 0.0008

24

FR = base freezing index defined as percentage of time the top base temperature is below

freezing (32 oF) temperature.

Model Statistics are:

R2 = 0.71

SEE = 0.029 inches


The JPCP transverse joint faulting model is a result of the calibration based on performance of

248 field sections located in 22 States and is applicable for both doweled and undoweled JPCP.

2.4.2.3 CRCP Punchout Model

CRCP punchout are predicted using a calibrated model, which predicts punchouts as a function

of accumulated fatigue damage due to top-down stresses in transverse direction. The nationally

calibrated model is as follows:

POA

1 α FDβ⋅+ (2.43)

where,

PO = total predicted number of punchouts per mile

FD = accumulated fatigue damage at the end of the yth year

A, α, β = calibration constants (105.26, 4.0, -0.38 respectively)

Model Statistics:

R2 = 0.67

SEE = 4.73 punchouts per mile

N = 220

25

The CRCP punchout model was calibrated based on performance of 74 field sections from 23

states.

The greatest challenge was to calibrate the mechanistic-based conceptual models with

nationally available field performance data. This had never been successfully accomplished

before nationally. After the theoretical distress models were formulated they were compared and

calibrated against the observed data. The results were then evaluated which lead to

improvements to the model, which in turn required another time consuming calibration. This

process was repeated many times to achieve each of the final acceptable mechanistic based

distress prediction models. After model calibration was completed, design reliability was

incorporated into the design procedure by considering the residual between the observed and

predicted distress.

The complex models and the design concepts were finally incorporated into a user

friendly software package. The software package includes climatic database containing an hourly

climatic data from over 800 locations in North America, which allows the user to easily select a

given station or to generate virtual weather stations. Another very important feature of the design

procedure and software is that improvements can be made over time in a piecewise manner to

any of the component models and incorporated into the procedure for recalibration. Ranges and

default values of design inputs can be set by local agencies.

According to the results of sensitivity analysis of the AASHTO 2002 design guide

conducted by Masad (7), the base modulus and thickness have significant influence on the

international roughness index and the longitudinal cracking. However, the base material

properties have almost no influence on the permanent deformation of the pavement.

26

The AASHTO 2002 design guide software is relatively complex and required a longer

time to run. On an average the run time for a 4 - layered flexible pavement system it took about

twenty five (25) minutes and for a rigid pavement system it took about seven (7) minutes. These

run times resulted with a computer configuration of Intel(R) Pentium (R) M processor 1.50 GHz

with 1.0 GB RAM.

27

CHAPTER THREE: AASHTO 2002 DESIGN METHODOLOGY

3.1 Introduction

The AASHTO 2002 Design Guide is based on mechanistic – empirical approach to

pavement design. The design procedure in this guide contributes a major improvement from the

existing empirical design procedure. The procedures in this guide has the capability to both

structurally and climatically model the pavement structure using mechanistic principles and

requires a much more comprehensive input data for analysis. These procedures have been

calibrated using design inputs and performance data largely from the national LTPP database

which includes sections located throughout significant parts of North America.

The mechanistic–empirical design requires an iterative hands-on approach by the

designer. The designer must first establish a performance criterion, then select a trial design, and

finally analyze the design in detail to see if it meets the established performance criteria. If the

trial design does not meet the performance criteria, the design is then modified and reanalyzed

until the design does satisfy all criteria. The designs that meet the applicable criteria are

considered feasible from structural and functional viewpoint.

The major steps in the design process according to this design guide can be summarized

as follows:

1. Assemble a trial design for specific site conditions – define pavement layer material

properties, traffic loads, climate, pavement type and design and construction features.

2. Establish criteria for acceptable pavement performance at the end of the design period. (i.e.

acceptable levels of rutting, fatigue cracking, thermal cracking, faulting, punchouts, IRI etc.)

28

3. Select the desired level of reliability for each of the performance indicators.

4. Process input to obtain monthly values of traffic inputs and seasonal variations of material

and climatic inputs needed in the design evaluations for the entire design period.

5. Compute structural responses (stresses and strains) using multilayer elastic theory or finite

element based pavement response models for each axle type and load and for each damage

calculation increment throughout the design period.

6. Calculate the accumulated distress and/or damage at the end of the each analysis period for

the entire design period.

7. Predict key distresses at the end of the analysis period throughout the design life using the

calibrated mechanistic – empirical performance models provided in the guide.

8. Predict smoothness (IRI) as a function of initial IRI, distresses that accumulate over time, and

site factors at the end of each time increment.

9. Evaluate the expected performance of the trial design at the given reliability level.

10. If the trial design does not meet the performance criteria, modify the design and repeat steps

4 through 9 above until the design does meet the criteria.

3.2 Pavement Design Components

3.2.1 Design Inputs

The ASHTO 2002 design procedure has the capability to consider a wide range of

structural sections. The designer must provide inputs for the project site conditions including

subgrade properties, traffic and climatic data as well as several design inputs related to

29

constructions such as the initial smoothness (IRI), estimated month of construction, and

estimated month that the pavement will be opened to the traffic.

For the convenience of the designer the design inputs are divided into three different

levels of data quality.

Level 1 – refers to the site and/or material specific inputs obtained through direct testing or

measurements.

Level 2 - refers to the use of correlations to establish and determine the required inputs.

Level 3 - refers to the use of national or regional default values to define the input.

Most of the design inputs considered in sensitivity analysis done in this report are level 3

inputs. The input level for a particular parameter is decided based on the criticality of the project,

sensitivity of the pavement performance to the given input, the information available at the time

of the design and also the resources and the time available to the designer to obtain the input.

Sensitivity analysis can be used to determine which parameter should be determined more

precisely for a given project.

3.2.2 Processing of inputs over design analysis period

Seasonal values of traffic, material and climatic inputs are needed for each analysis

increment in the design evaluations. These are obtained by processing the raw design inputs

which is automated in the design guide software and the processed inputs are then directly fed in

to the structural response calculation modules that compute critical pavement responses on a

period by period basis over the entire design period.

30

Analysis inputs that are required on a seasonal basis for flexible pavements consist of the

average daily number of single, tandem, tridem, and quad axles in each axle weight category for

each month, temperature within the asphalt layer, average moduli of all unbound layers (base,

subbase, subgrade) for each analysis period.

The analysis inputs that are required on a seasonal basis for rigid pavements consists of

the average hourly number of single, tandem, tridem and quad axles in each axle weight category

for each month of the analysis period

3.2.3 Pavement Response Model

The purpose of the pavement response model is to determine the structural response of

the pavement system due to traffic loads and environmental influences. Of particular interest are

the critical response variables required as inputs to the pavement distress models in the

mechanistic – empirical design procedure. Examples of the critical response variable include:

Tensile / Horizontal strain at the bottom/top of the HMA layer (for HMA fatigue cracking)

Compressive / Vertical stresses / strains within the HMA layer

Compressive / Vertical stresses / strains within the base / subbase layers

Compressive / Vertical stresses / strains at top of the subgrade

3.2.4 Incremental Distress and Damage accumulation

The design guide is based upon incremental damage approach. The trial design is

analyzed for adequacy by dividing the target design life into shorter design analysis period

beginning with the traffic opening month. Within each increment, all factors that affect pavement

31

responses and damage are held constant. These include Traffic levels, Asphalt Concrete

Modulus, Base and Subbase Moduli and Subgrade Modulus for flexible pavement analysis and

PCC Strength and Modulus, Base Modulus, Subgrade Modulus, Joint Load Transfer and Base

Erosion and Loss of Support for Rigid Pavement Analysis. Incremental distresses and/or damage

are summed over all increments and output at the end of each analysis period by the design guide

software.

3.2.5 Distress Prediction

The cumulative distress calculated and accumulated forms the basis for evaluating the

structural adequacy of the trial designs formulated. A variety of structural distresses are

considered in pavement design and analysis.

The structural distresses considered for flexible pavement design include Bottom-up

fatigue cracking, Surface down fatigue cracking, Permanent Deformation (Rutting), Thermal

Cracking and Terminal IRI.

The rigid pavement structural distresses considered in this guide include Joint Faulting

and Transverse Cracking for JPCP, Punchouts for CRCP, and International Roughness Index

(IRI) for both rigid pavement types.

The following includes a brief explanation of the above distresses:

3.2.5.1 International Roughness Index (IRI)

IRI was developed to provide a common quantitative basis on which different measures

of roughness can be compared. IRI summarizes the longitudinal surface profile in the wheelpath

32

and is computed from surface elevation data collected by either a topographic survey or a

mechanical profilometer. It is defined by the average rectified slope (ARS), which is a ratio of

the accumulated suspension motion to the distance traveled obtained from a mathematical model

of a standard quarter car traversing a measured profile at 50 mph. It is expressed in units of

inches per mile. The initial IRI which defines the as-constructed smoothness of the pavement

typically ranges from 50 to 100 in/mile. The performance criterion for smoothness is defined by

the acceptable IRI at the end of the design life. Typical values for Terminal IRI are chosen in the

range of 150 to 250 in/mile depending on the functional class of the roadway and design

reliability.

The IRI over the design period depends upon the initial as-constructed profile of the

pavement from which the initial IRI is computed and upon the subsequent development of

distresses over time. These distresses include rutting, bottom-up/top-down fatigue cracking and

thermal cracking for flexible pavements and transverse slab cracking, joint spalling and joint

faulting for Jointed Plain Concrete Pavement (JPCP) and punchouts for Continuous Reinforced

Concrete Pavement (CRCP). The IRI over time is predicted by using the distresses predicted

over time by the distress models and site factors. The site factors include the subgrade and

climatic factors to account for the roughness caused by the shrinking or swelling soils and frost

heave conditions.

3.2.5.2 Bottom-up Fatigue cracking or Alligator cracking

This type of fatigue cracking first shows up as short longitudinal cracks in the wheel path

that quickly spread and become interconnected to form an alligator cracking pattern. The cracks

33

initiate at the bottom of the HMA layer and propagate to the surface under repeated load

applications. This type of fatigue cracking is a result of the repeated bending of the HMA layer

under traffic. The pavement and HMA layer deflect under wheel loads that result in tensile

strains and stresses at the bottom of the layer. With continued bending the tensile stresses and

strains cause cracks to initiate at the bottom of the layer and then propagate to the surface. The

performance criterion for bottom up fatigue cracking is defined as the maximum area of alligator

cracking expressed as a percentage of the total lane area that is permitted to occur over the

design period. Typical values of the allowable-bottom up fatigue cracking are in the range of 25

to 50 percent of the total lane area.

3.2.5.3 Surface-down fatigue cracking or Longitudinal Cracking

These are load-related cracks that initiate at the surface and propagate downward. These

cracks initiate and propagate in tension due to the wheelload induced tensile stresses and strains

that occur at the surface. Also high contact pressure near the edge of the tire results in the

shearing of the HMA surface mixture and causes cracks to initiate and propagate both in shear

and tension. Severe aging of HMA mixtures results in high stiffness and combined with high

contacts pressure, adjacent to tire loads results, cause the cracks to initiate at the surface. The

performance criterion for surface-down fatigue cracking is defined as the maximum allowable

length of longitudinal cracking per mile of the pavement that is permitted to occur over the

design period. Typical values of allowable surface-down fatigue cracking are on the order of

1000 ft per mile of pavement.

34

3.2.5.4 Thermal Cracking

Thermal cracking is caused in flexible pavements due to cold temperatures or

temperature cycling. These cracks typically appear as transverse cracks on the pavement surface

roughly perpendicular to the pavement centerline. These cracks can be caused by the shrinkage

of the HMA surface due to low temperatures, hardening of the asphalt and/or daily temperature

cycles. The performance criterion for thermal cracking is defined as the maximum length of

transverse cracking per mile of pavement that is permitted to occur over the design period.

Typical values of the allowable thermal cracking are of the order of 1000 ft per mile of

pavement.

3.2.5.5 Permanent Deformation

Permanent deformation is a surface depression in the wheel paths caused by plastic

deformation in any or all of the pavement layers. These deformations occur mainly due to

densification or one dimensional compression or consolidation and lateral movements or plastic

flow of materials from wheel loads. Rutting is a major contributor of loss of pavement

smoothness. It can also create functional problems such as water ponding and handling problem

for vehicles during lane changes. The performance criterion for total permanent deformation is

defined in terms of the maximum rut depth in the wheel path. Typical maximum rut depths for

total permanent deformation are on the order of 0.3 to 0.5 inches.

35

3.2.5.6 Joint Faulting for JPCP

Repeated heavy axle loads crossing transverse joints create the potential for joint faulting.

The mean transverse joint faulting is a critical factor affecting ride quality. The performance

criteria for joint faulting, defines the allowable amount of mean joint faulting at the end of the

design life and determines the level of joint faulting over the design period. The typical

acceptable levels of mean joint faulting ranges from 0.1 to 0.2 inches depending on the

functional class of roadway and design reliability.

3.2.5.7 Transverse Slab Cracking in JPCP

When the truck axles are near the longitudinal edge of the slab, midway between the

transverse joints, a critical tensile bending stress occurs at the bottom of the slab. With a high

positive gradient through the slab the stress increases greatly and results in fatigue damage along

the bottom edge of the slab which eventually results in a transverse crack that propagates to the

surface of the pavement. Fatigue damage at the top of the slab resulting in transverse cracking at

the surface of the pavement can also be caused due to repeated heavy truck loads with certain

axle spacings, when the pavement is exposed to high negative temperature gradient Inadequate

design to control transverse cracking may result in premature failing of the JPCP. The

performance criterion for transverse cracking defines the maximum allowable percentage of

cracked slabs at the end of the design life. Typical values of allowable cracking range from 10 to

45 percent depending on the functional class of the roadway and design reliability.

36

3.2.5.8 Punchouts in CRCP

When truck axles pass along near the longitudinal edge of the slab between two closely

spaced transverse cracks a high tensile stress occurs at the top of the slab. This stress increases

greatly when there is loss of load transfer across the transverse cracks or loss of support along

the edge of the slab resulting in fatigue damage at the top of the slab which results first in micro-

cracks that initiate at the transverse crack and propagate longitudinally across the slab to the

other transverse crack causing CRCP punchouts. The performance criterion for punchout defines

the acceptable number of punchouts per mile at the end of the design life and also determines the

number of punchouts that may develop over the design period. Typical values of allowable

CRCP punchouts range from 10 to 20 per mile.

3.2.6 Design Reliability:

The desired level of reliability is specified along with the acceptable level of distress at

the end of the design life in defining the performance requirements for a pavement design. For

example, one criterion might be to limit the rut depth to 1” (25 mm) at a design reliability of 90

percent. Thus, if a designer designed 100 projects, 90 of these projects would exhibit rut depths

less than 1” (25 mm) at the end of the design period. Different reliability may be specified for

different distresses in the same design.

37

CHAPTER FOUR: RESULTS OF SENSITIVITY ANALYSIS

Various analyses were done to investigate the sensitivity of various pavement distresses

with respect to changes in the design parameters for flexible and rigid pavements. In order to

achieve this, a sample problem was selected and key design parameters were identified. These

selected parameters were varied one at a time and all the other design parameters were kept

constant and their effect on the various pavement distresses was found.

4.1 Flexible Pavement Sensitivity Analysis

A sample problem is executed as given in the following design.

Analysis Parameters:

Design Life - 20-year design life

Initial IRI - 75 in/mile

Maximum Acceptable Terminal IRI – 200 in/mile

Maximum Acceptable AC surface-down or longitudinal cracking <= 1000 ft/mile

Maximum Acceptable Bottom-up fatigue cracking <= 25 percent

Maximum Acceptable AC thermal fracture (transverse cracking) <= 1000 feet per mile

Maximum Acceptable total permanent deformation in the AC layer <= 0.25 inches

38

Maximum Acceptable permanent deformation pavement (total pavement) <= 0.75 inches

These criteria are to be satisfied at a reliability level of 90 percent

The depth of the water table -10 feet

Traffic Data

Initial two-way average annual daily truck traffic (AADTT) - 1500 trucks

Number of Lanes in the design direction – 2

Percent of Trucks in the Design Lane 50%.

Operational speed - 60 mph.

Pavement will be open to traffic in the month of October

The percentage of AADTT in each vehicle class is assumed to be same as the default Truck

Traffic Classification 1 based on LTPP traffic data as shown in the table below:

Table 1 Truck Traffic Classification 1 based on LTPP traffic data

Vehicle Class Percent AADTT in ClassClass 04 1.3 Class 05 8.5 Class 06 2.8 Class 07 0.3 Class 08 7.6 Class 09 74.0 Class 10 1.2 Class 11 3.4 Class 12 0.6 Class 13 0.3

Traffic growth rate - 4.0% of the preceding year’s traffic (compounded annually).

39

The axle load distribution is identical to the national defaults (derived from LTPP)

provided with the Design Guide software for each vehicle class, axle type, load category, and

months of the year. The number of single, tandem, tridem and quad axles for each vehicle class

is also same as the national defaults derived from LTPP data (provided in the Design Guide and

the software).

Axle configuration:

Average axle width (edge-to-edge outside dimensions, ft) - 8.5

Dual tire spacing (in) -12

Single and dual tire pressures - 120 psi.

Design lane Width - 12 feet wide

Table 2: The average axle spacing for tandem, tridem and quad axles

Axle Type Axle Spacing (in)Tandem 51.6 Tridem 49.2 Quad 49.2

Drainage and Surface Properties:

Cross slope - 2 %

Length drainage path - 12 feet

Shortwave absorptivity of 0.85.

Asphalt Material Properties:

The asphalt concrete mix to be used in this study has material property information in

compliance with level 3 inputs for the Design Guide. Sieve analysis results for the aggregate to

40

be used in the mix suggest that the ¾”, 3/8”, and #4 size sieves have 12, 38, and 50 percentage

aggregate retained on them respectively. 4 percent passes through the #200 sieve. A PG grade

64-22 or 64-28 binder will be used for the asphalt mix design.

The volumetric design of the mix includes 12 percent binder content, 6 percent air voids,

and the mix has a unit weight of 143 lb per cubic foot. Assume a thermal conductivity of 0.67

BTU/hr-ft-oF and a specific heat of 0.23 BTU/lb-oF. Also assume that the poison’s ratio is 0.35.

The reference temperature is 70 deg F. The asphalt layer thickness for the use in the trial design

is 3 in.

Subgrade:

The subgrade in this location is classified as A-7-6 per the AASHTO classification

system, and has a resilient modulus (Mr) value of 10,000 psi estimated at optimum conditions.

The plasticity index of the soil is 40. Results from sieve analysis of this subgrade soil indicated

that 90% of the material passes the #200 sieve, and 99% passes the #4 sieves, the subgrade is

basically clay soil. The D60 of this material is 0.01mm:

Other layers:

The available base and subbase materials for this study are classified as A-1-a and A-2-5,

with modulus of 40,000 psi and 28,000 psi at optimum moisture content respectively. The A-1-a

and A-2-5 materials having a PI of 1.0 and 2.0 have 3% and 20% passing the #200 sieve, 20%

and 80% passing the #4 sieve, and have D60 values of 8 and 0.1mm respectively. The base layer

thickness is taken as 6 in and the subbase layer thickness is 9 in for the trial design. Table 3

shows the list of trial values used in the sensitivity analysis.

41

Table 3: List of the parameters used in the sensitivity analyses of Flexible pavement

Input Parameters Default Value For Sensitivity

Analyses

1 Design Life 20 yrs Constant

2 AADTT 1500 500 – 3000

3 Initial IRI 75 in/mile Constant

4 Maximum Acceptable Terminal IRI 200 in/mile Constant

5 Max. Acceptable AC surface down cracking 1000 ft/mile Constant

6 Max. Acceptable AC bottom up cracking 25% Constant

7 Max. Acceptable AC thermal fracture 1000 ft/mile Constant

8 Max. Acceptable Permanent Deformation (AC

only)

0.25 in Constant

9 Max. Acceptable Permanent Deformation (Total

Pavement)

0.75 in Constant

10 AC layer thickness 3 in 2 – 7 in

11 Base layer thickness 6 in 5 – 10 in

12 Base layer Modulus 40,000 psi 38,500 – 42,000 psi

13 Subbase layer thickness 9 in 7 – 12 in

14 Subbase layer Modulus 28,000 psi 25,000 – 33,000 psi

15 Subgrade Modulus 10000 psi 5,000 – 13,500 psi

42

To conduct a sensitivity analyses, the effects on the pavement distresses were obtained

with changing the values of one parameter while keeping all other parameters constant. The

following is a brief summary result of each of the sensitivity analyses.

1. Terminal IRI vs AADTT

Terminal IRI v/s AADTT

88

90

92

94

96

98

100

500 1000 1500 2000 2500 3000

AADTT

Term

inal

IRI (

in/m

i)

Design Life = 20 yrsAC Layer Thickness = 3 inBase Layer Thickness = 6 inBase Layer Modulus = 40,000 psiSubbase Layer Thickness = 9 inSubbase Layer Modulus = 28,000 psiSubgrade Modulus = 10,000 psi

Figure 1: Terminal IRI vs AADTT

The plot of Terminal IRI versus AADTT is shown in Figure 1. From the graph it can be

seen that the terminal IRI increases with the increase in AADTT. Thus, it concludes that the

increase of the traffic load results in decreasing the terminal smoothness of the pavement. An

increase in AADTT from 500 to 3000 results in an increase of the Terminal IRI from 89.3 to

43

98.5. The initial IRI for a newly constructed pavement is about 75 in/mile and the maximum

acceptable terminal IRI is 200 in/mile. From the plot it appears that even for a heavy load of

3000 AADTT, the terminal IRI is not reached. Therefore, AADTT has only a minor effect on the

pavement smoothness.

2. AC surface down cracking vs AADTT

AC surface down cracking (longitudinal cracking) vs AADTT

0

0.2

0.4

0.6

0.8

1

1.2

1.4

500 1000 1500 2000 2500 3000

AADTT

AC

sur

face

dow

n (lo

ngitu

dina

l) cr

acki

ng (f

t/mile

)


Figure 2: AC surface down cracking vs AADTT

The plot of AADTT versus surface down cracking is shown in Figure 2. From the graph

it can be seen that the AC surface down cracking increases with the increase of AADTT. An

increase of AADTT from 500 to 3,000 results in an increase of AC surface down cracking from

0.1 to 1.3 ft/mi. The surface down cracking of 1,000 ft/mile is considered a severe surface

distress and a value of surface down cracking over 1,000 ft/mile is not acceptable. In this case,

44

even with a heavy load of 3,000 AADTT the surface down cracking is only 1.3 ft/mile. This

indicates that AADTT has a little effect on AC surface down cracking.

3. AC bottom up cracking vs AADTT

AC bottom up cracking (alligator cracking) vs AADTT

0

5

10

15

20

25

30

500 1000 1500 2000 2500 3000

AADTT

AC

bot

tom

up

(alli

gato

r) c

rack

ing

(%)


Figure 3: AC bottom up cracking vs AADTT

The plot of AADTT versus AC bottom up cracking is shown in Figure 3. From the graph

it can be seen that the AC bottom up cracking increases with the increase of AADTT. An

increase of AADTT from 500 to 3,000 results in an increase of AC bottom up cracking from

2.8% to 25.2%. This indicates that the repeated heavy traffic load applications will initiate cracks

from the tensile stresses and strains at the bottom of the AC layer and propagate to the surface.

The allowable AC bottom up cracking for design is 25%. In this case for an AADTT of 3,000 the

45

cracking at the bottom of AC is 25.2%. The result implies that, the given pavement system

cannot be sustained for an AADTT of 3,000. Thus, AADTT has a major effect on the bottom up

cracking of the Asphalt Concrete layer.

4. AC thermal Fracture vs AADTT

AC thermal fracture vs AADTT

0

0.2

0.4

0.6

0.8

1

1.2

500 1000 1500 2000 2500 3000

AADTT

AC

ther

mal

frac

ture

(ft/m

i)


Figure 4: AC Thermal Fracture vs AADTT

The plot of AADTT versus AC thermal fracture is shown in Figure 4. From the graph it

can be seen that AADTT has no effect on the AC thermal cracking. An increase in AADTT from

500 to 3,000 results in no change in the AC thermal fracture. These cracks are mostly initiated by

the extremes in the daily and seasonal temperatures.

46

5. Permanent Deformation (AC only) vs AADTT

Permanent Deformation (AC only) vs AADTT

0

0.1

0.2

0.3

0.4

0.5

0.6

500 1000 1500 2000 2500 3000

AADTT

Perm

anen

t Def

orm

atio

n (A

C o

nly)

(in)


Figure 5: Permanent Deformation (AC only) vs AADTT

The plot of permanent deformation (AC layer only) versus AADTT is shown in Figure 5.

The plot shows that for a constant AC layer thickness of 3 in, an increase of AADTT results in

an increase of the permanent deformation in the AC layer. An increase of the AADTT from 500

to 3,000 results in an increase of the permanent deformation of the AC layer from 0.22 inches to

0.52 inches. The acceptable permanent deformation in AC layer is limited to 0.25 inches for the

given example. From the plot, the given pavement system can only sustain 500 AADTT for

acceptable 0.25 inches of AC permanent deformation. Therefore, the permanent deformation in

AC layer is highly sensitive to AADTT applications.

47

6. Permanent Deformation (Total Pavement) vs AADTT

Permanent Deformation (Total Pavement) vs AADTT

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1

500 1000 1500 2000 2500 3000

AADTT

Perm

anen

t Def

orm

atio

n (T

otal

Pav

emen

t) (in

)


Figure 6: Permanent Deformation (Total Pavement) vs AADTT

With all the other input parameters constant, it is seen that the increase of AADTT results

in an increase of the permanent deformation of the pavement. An increase of AADTT from 500

to 3,000 results in an increase of the permanent deformation of the total pavement from 0.5

inches to 0.89 inches. For an acceptable 0.75 inches of total pavement deformation in this

example, not more than 1500 AADTT can be applied for the given pavement system. For an

AADTT of 3000, out of the total permanent deformation of 0.89 inches, 0.52 inches is

contributed by AC layer, 0.07 inches by base layer and 0.30 inches by subgrade layer as can be

seen in the next graph (Figure 7) obtained as an output from AASHTO 2002 Design Guide.

48

Figure 7: Permanent Deformation in different pavement layers over the design life




49

7. Terminal IRI vs AC layer thickness

Terminal IRI vs AC layer thickness

87

88

89

90

91

92

93

94

2 2.5 3 3.5 4 4.5 5 5.5 6 6.5 7

Asphalt Layer Thickness (in)

Term

inal

IRI (

in/m

i)

Design Life = 20 yrsAADTT = 1500Base Layer Thickness = 6 inBase Layer Modulus = 40,000 psiSubbase Layer Thickness = 9 inSubbase Layer Modulus = 28,000 psiSubgrade Modulus = 10,000 psi

Figure 8: Terminal IRI vs AC Layer Thickness

The plot of terminal IRI versus AC layer thickness is shown in Figure 8. The IRI values

were obtained by varying AC layer thickness from 2 to 7 inches. From the plot it reveals that AC

layer thickness has a minor effect on the terminal IRI. It is interesting to see that the terminal IRI

increases as the AC layer thickness is increased from 2 to 3 inches. However, the terminal IRI

decreases with further increase in the AC layer thickness. Thus, for the given data, it is obvious

that a minimum of 3 inches AC thickness should be designed to prevent the increase of the

terminal IRI. This may be the fact that many thinner AC roads have premature cracking.

50

8. AC surface down cracking vs AC layer thickness

AC surface down cracking longitudinal cracking vs AC layer thickness

0

50

100

150

200

250

300

350

400

450

2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 6.0 6.5 7.0

AC layer thickness (in)

AC

sur

face

dow

n cr

acki

ng (f

t/mi)


Figure 9: AC Surface down cracking vs AC Layer Thickness

The plot of AC surface down cracking versus AC layer thickness varied from 2 to 7

inches is shown in Figure 9. It is interesting to note that for AC layer thickness between 2 and 4

inches, there is minimal surface down cracking. However, when the layer thickness is increased

further, the AC surface down cracking increases sharply and reaches 409 ft/mile at AC layer

thickness of 6 inches. Yet, this still less than the maximum allowable limit of 1000 ft/mile. When

the AC layer thickness is increased beyond 6 inches there is again a decrease in the surface down

cracking. The result may imply that AC surface down cracking would no longer be affected if

the AC thickness is over 6 inches.

51

9. AC bottom up cracking vs AC layer thickness

AC bottom up cracking (alligator cracking) vs AC layer thickness

0

2

4

6

8

10

12

14

2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 6.0 6.5 7.0

Asphalt Layer thickness (in)

AC

bot

tom

up

crac

king

(%)


Figure 10: AC bottom up cracking vs AC layer thickness

The plot of AC bottom up cracking versus AC layer thickness varied from 2 to 7 inches is

shown in Figure 10. The graph shows that for an AC layer thickness between 2 and 4 inches,

there is a sharp increase in the bottom up cracking. But as the AC layer thickness is increased

beyond 4 inches the bottom up cracking decreases. Yet, an AC layer thickness of 4 inches would

only result in maximum bottom up cracking of 12.40% that is still less than 50% of the

maximum allowable limit of 25%. This implies that for the given data, a 4 inches thickness

would result in no bottom up cracking.

52

10. AC thermal fracture vs AC layer thickness

AC thermal fracture vs Asphalt layer thickness

0.0

0.2

0.4

0.6

0.8

1.0

1.2

2 3 3 4 4 5 5 6 6 7 7

Asphalt layer thickness (in)

AC

ther

mal

frac

ture

(ft/m

i)


Figure 11: AC thermal fracture vs Asphalt Layer thickness

The plot of AC thermal fracture versus AC layer thickness is shown in Figure 11. From

the Figure it can be seen that the AC layer thickness does not have any effect on the thermal

cracking of AC layer.

53

11. Permanent Deformation (AC only) vs AC layer thickness

Permanent Deformation (AC only) vs AC thk

0.00

0.05

0.10

0.15

0.20

0.25

0.30

0.35

0.40

2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 6.0 6.5 7.0


Perm

anen

t Def

orm

atio

n (A

C o

nly)

(in)


Figure 12: Permanent Deformation (AC only) vs Asphalt Layer Thickness

The plot of Permanent Deformation (AC only) versus AC layer thickness is shown in

Figure 12. The graph shows that the Permanent deformation in the AC layer increases as the AC

layer thickness is increased from 2 to 3 inches. But with further increase of the AC layer

thickness beyond 3 inches, the permanent deformation in the AC layer slightly decreases. Since

the maximum allowable permanent deformation in AC layer is 0.25 in, a minimum of 6 inches

AC layer thickness should be required in order to restrict the AC layer deformation to less than

0.25 inches.

54

12. Permanent Deformation (Total Pavement only) vs AC layer thickness

Permanent Deformation (Total Pavement) vs AC layer thickness

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

2 2.5 3 3.5 4 4.5 5 5.5 6 6.5 7


Perm

anen

t Def

orm

atio

n (T

otal

Pav

emen

t) (in

)


Figure 13: Permanent Deformation (Total Pavement) vs AC layer thickness

The plot of Permanent Deformation of total pavement versus AC layer thickness is

shown in Figure 13. From the plot it appears that the Permanent deformation of the total

pavement decreases as the AC layer thickness increases from 2 to 7 inches. The result implies

that an increase of the AC layer thickness will decrease the rut depths in the total pavement

system. The maximum allowable permanent deformation for total pavement is 0.75 inches.

Therefore, the ranges of AC layer thickness from 2 to 7 inches would not cause the problem of

total permanent deformation beyond allowable limit as can be seen from the graph.

55

13. Terminal IRI vs Base Layer Thickness

Terminal IRI vs Base Layer Thickness

92.0

92.2

92.4

92.6

92.8

93.0

93.2

93.4

93.6

93.8

94.0

5.0 5.5 6.0 6.5 7.0 7.5 8.0 8.5 9.0 9.5 10.0

Base Layer Thickness (in)

Term

inal

IRI (

in/m

i)

Design Life = 20 yrsAADTT = 1500AC Layer Thickness = 3 inBase Layer Modulus = 40,000 psiSubbase Layer Thickness = 9 inSubbase Layer Modulus = 28,000 psiSubgrade Modulus = 10,000 psi

Figure 14: Terminal IRI vs Base layer thickness

The plot of Terminal IRI versus Base Layer Thickness is shown in Figure 14. The plot

shows that the Terminal IRI changes abruptly with the changes in the Base Layer Thickness.

However, the general trend of the curve is the decrease in terminal IRI with the increase in the

base layer thickness. The role of base layer is basically to transfer the load from the stronger AC

layer to the relatively weaker subgrade. This concludes that, with the given data of the pavement

system, the change in the base layer thickness does not result in terminal IRI beyond the

maximum allowable limit of 200 in/mile.

56

14. AC surface down cracking vs Base Layer Thickness

AC surface down cracking (longitudinal cracking) vs Base Layer Thickness

0.0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

5.0 5.5 6.0 6.5 7.0 7.5 8.0 8.5 9.0 9.5 10.0


AC

sur

face

dow

n cr

acki

ng (f

t/mile

)


Figure 15: AC surface down cracking vs Base layer thickness

The plot of AC surface down cracking versus Base Layer Thickness is shown in Figure

15. The plot shows that, as the base layer thickness is increased from 5 to 6 inches the AC

surface down cracking decreases. Then for base layer thickness of 6 to 7 inches, the AC surface

down cracking remains constant. The AC surface down cracking decreases as the base layer

thickness is increased from 7 to 8 inches. With further increase in the base layer thickness

beyond 8 inches the AC surface down cracking remains constant. It can be noted that the

57

maximum allowable limit of 1000 ft/mile for AC surface down cracking is not exceeded when a

range of base layer thicknesses from 5 t 10 inches are used for pavement design.

15. AC bottom up cracking vs Base Layer Thickness

AC bottom up cracking (alligator cracking) vs Base Layer thickness

0.0

2.0

4.0

6.0

8.0

10.0

12.0

14.0

16.0

5.0 5.5 6.0 6.5 7.0 7.5 8.0 8.5 9.0 9.5 10.0


AC

bot

tom

up

crac

king

(%)


Figure 16: AC bottom up cracking vs Base layer thickness

The plot of AC bottom up cracking versus Base Layer Thickness varied from 5 to 10

inches is shown in Figure 16. The plot shows that the AC bottom up cracking changes abruptly

with the changes in the Base Layer Thickness. However, the general trend of the curve is the

decrease in AC bottom up cracking with the increase in the Base Layer thickness. This is

because a greater base layer thickness helps in transferring the load to the subbase and subgrade

58

layers as well as reduces the tensile strains at the bottom of the AC layer. It can also be noted

that, with the given pavement configuration and using a range of 5 to 10 inches thickness of base

layer the maximum allowable limit of 25% for bottom up cracking is not exceeded.

16. AC Thermal Fracture vs Base Layer Thickness

AC thermal fracture vs Base Layer Thickness

0.0

0.2

0.4

0.6

0.8

1.0

1.2

5.0 5.5 6.0 6.5 7.0 7.5 8.0 8.5 9.0 9.5 10.0


AC

ther

mal

frac

ture

(ft/m

i)


Figure 17: AC thermal fracture vs Base layer thickness

The plot of AC Thermal Fracture versus Base Layer Thickness is shown in Figure 17.

The plot shows that the change in the base layer thickness has no effect on the AC thermal

fracture and it remains constant with the changes in the base layer thickness.

59

17. Permanent Deformation AC only vs Base Layer Thickness

Permanent Deformation (AC only) vs Base Layer Thickness

0.358

0.360

0.362

0.364

0.366

0.368

0.370

0.372

5.0 5.5 6.0 6.5 7.0 7.5 8.0 8.5 9.0 9.5 10.0


Perm

anen

t Def

orm

atio

n (A

C o

nly)

(in)


Figure 18: Permanent Deformation (AC only) vs Base layer thickness

The plot of permanent deformation (AC only) versus the base layer thickness is shown in

Figure 18. From the plot, it reveals that the Permanent Deformation in the AC layer remains

constant with increase in the base layer thickness from 5 to 8 inches. With further increase in the

base layer thickness from 8 to 9 inches, the Permanent Deformation in the AC layer decreases by

0.01 inch. The permanent deformation in the AC layer remains constant with the increase in the

base layer thickness from 9 to 10 inches. Therefore it can be concluded, that the change in the

base layer thickness has a minor effect on the Permanent Deformation in the AC layer.

60

18. Permanent Deformation (Total Pavement) vs Base Layer Thickness

Permanent Deformation (Total Pavement) vs Base Layer Thickness

0.685

0.690

0.695

0.700

0.705

0.710

0.715

0.720

0.725

5.0 5.5 6.0 6.5 7.0 7.5 8.0 8.5 9.0 9.5 10.0


Perm

anen

t Def

orm

atio

n (in

)


Figure 19: Permanent deformation (total) pavement vs Base Layer thickness

The above plot shows that permanent deformation of the total pavement decreases as the

base layer thickness is increased from 5 to 6 inches. For a base thickness of 6 to 7 inches the

permanent deformation remains constant. The permanent deformation decreases for 7 to 8 inches

of base thickness, remains constant for 8 to 9 inches base thickness and again decreases for 9 to

10 inches of base thickness. Thus the general trend of the curve is that the permanent

deformation in the total pavement decreases as the base layer thickness increases. In some cases

the permanent deformation is the same for two different thicknesses. In such cases the smaller of

61

the two thicknesses must be used for pavement design. It can also be concluded, that with the

given data of the pavement system, the change in base layer thicknesses from 5 to 10 inches does

not result in total pavement deformation beyond the maximum allowable limit of 0.75 inch.

19. Terminal IRI vs Base Layer Modulus

Terminal IRI vs # Base Layer Modulus

92.4

92.5

92.6

92.7

92.8

92.9

93.0

93.1

93.2

93.3

93.4

38500 39000 39500 40000 40500 41000 41500 42000

Base Layer Modulus (psi)

Term

inal

IRI (

in/m

i)

Design Life = 20 yrsAADTT = 1500AC Layer Thickness = 3 inBase Layer Thickness = 6 inSubbase Layer Thickness = 9 inSubbase Layer Modulus = 28,000 psiSubgrade Modulus = 10,000 psi

Figure 20: Terminal IRI vs Base layer modulus

The plot of Terminal IRI versus base layer Modulus is shown in Figure 20. The plot

shows that Terminal IRI decreases with the increase in the base layer modulus values. For a

change in base layer modulus from 38,500 psi to 42,000 psi, the terminal IRI decreases from

93.3 to 92.5 in/mile. It can also be noted, that with the given data of pavement system and using

62

different base layer modulus, the maximum acceptable limit of 200 in/mile for the Terminal IRI

is not exceeded at the end of the design life.

20. AC surface down cracking vs Base Layer Modulus

AC surface down cracking longitudinal cracking vs # Base Layer Modulus

0.0

0.1

0.2

0.3

0.4

0.5

0.6

38500 39000 39500 40000 40500 41000 41500 42000


AC

sur

face

dow

n C

rack

ing

(ft/m

i)


Figure 21: AC surface down cracking vs Base layer modulus

The plot of AC surface down cracking versus base layer modulus is shown in Figure 21.

The plot shows that the AC surface down cracking remains constant with the increase in the base

layer modulus from 38500 to 39000 psi. There is a drop in the AC surface down cracking with

the increase in the base layer modulus from 39000 to 40000 psi. There is no change in the AC

surface down cracking with increase in the base layer modulus beyond 40,000 psi. The amount

63

of AC surface down cracking for the given pavement system is negligible compared to the

maximum allowable limit of 1000 ft/mile for the pavement. Therefore, it can be concluded that

the base layer moduli has a minor effect on the AC surface down cracking of the pavement.

21. AC bottom up cracking vs Base Layer Modulus

AC bottom up cracking (alligator cracking) vs Base Layer Modulus

10.0

10.5

11.0

11.5

12.0

12.5

38500 39000 39500 40000 40500 41000 41500 42000


AC

bot

tom

up

crac

king

(%)


Figure 22: AC bottom up cracking vs Base layer modulus

The plot of AC bottom up cracking versus base layer modulus is shown in Figure 22. The

plot shows that AC bottom up cracking decreases with the increase in the base layer modulus.

Thus a stiffer base layer decreases bottom up cracking in the asphalt concrete layer by limiting

64

the tensile stresses and strains at the bottom of the AC layer. It can be noted that the maximum

allowable limit of 25% for bottom up cracking is not exceeded for the given pavement system.

22. AC thermal fracture vs Base Layer Modulus

AC thermal fracture vs Base Layer Modulus

0.0

0.2

0.4

0.6

0.8

1.0

1.2

38500 39000 39500 40000 40500 41000 41500 42000


AC

ther

mal

Fra

ctur

e (ft

/mi)


Figure 23: AC thermal fracture vs Base layer modulus

The plot of AC thermal fracture versus base layer modulus is shown in Figure 23. The

plot shows that AC thermal fracture remains unchanged with the increase in the base layer

modulus. Thus AC thermal fracture is independent of the base layer modulus.

65

23. Permanent Deformation (AC only) vs Base Layer Modulus

Permanent Deformation (AC only) vs Base Layer Modulus

0.00

0.05

0.10

0.15

0.20

0.25

0.30

0.35

0.40

38500 39000 39500 40000 40500 41000 41500 42000


Pem

anen

t Def

orm

atio

n (A

C o

nly)

(in)


Figure 24: Permanent Deformation (AC only) vs Base layer modulus

The plot of permanent deformation (AC only) versus base layer modulus is shown in

Figure 24. From the Figure it can be seen that the Permanent Deformation (AC only) remains

constant at 0.37 inches with the increase in the base layer modulus, however it exceeds the

maximum allowable limit of 0.25 inches of permanent deformation in AC layer. Thus, it can be

concluded that the permanent deformation in the AC layer is independent of the stiffness of base

layer modulus.

66

24. Permanent Deformation (Total Pavement) vs Base Layer Modulus

Permanent Deformation (Total Pavement) vs Base Layer Modulus

0.698

0.700

0.702

0.704

0.706

0.708

0.710

0.712

38500 39000 39500 40000 40500 41000 41500 42000


Perm

anen

t Def

orm

atio

n (T

otal

Pav

emen

t) (in

)


Figure 25: Permanent deformation (Total Pavement) vs Base layer modulus

The plot of permanent deformation (Total Pavement) versus base layer is shown in the

Figure 25. The figure shows that permanent deformation in the total pavement remains constant

with the increase in the base layer modulus from 38,500 to 40,000 psi and then it decreases by

0.1 inches as the modulus increases from 40,000 to 40,500 psi. Beyond 40,500 psi the permanent

deformation remains constant. Since the maximum allowable permanent deformation is 0.75

inches, the quality of base course does not cause much impact on total pavement permanent

deformation.

67

25 Terminal IRI vs Subbase layer thickness

Terminal IRI vs Subbase Thickness

92.6

92.7

92.8

92.9

93.0

93.1

93.2

93.3

93.4

7.0 7.5 8.0 8.5 9.0 9.5 10.0 10.5 11.0 11.5 12.0

Subbase Layer Thickness (in)

Term

inal

IRI (

in/m

i)

Design Life = 20 yrsAADTT = 1500AC Layer Thickness = 3 inBase Layer Thickness = 6 inBase Layer Modulus = 40,000 psiSubbase Layer Modulus = 28,000 psiSubgrade Modulus = 10,000 psi

Figure 26: Terminal IRI vs Subbase thickness

The plot of terminal IRI versus subbase layer thickness is shown in Figure 26. From the

figure it can be concluded, that the terminal IRI decreases with the increase in the subbase layer

thickness. However, it is interesting to note that for the subbase layer thickness of 10 and 11

inches the terminal IRI value remains constant. The plot also shows that the effect of subbase

layer thickness on the terminal IRI is not too significant and the maximum allowable terminal

IRI value of 200 in/mile for the given pavement system is not exceeded.

68

26. AC surface down cracking vs Subbase Layer Thickness

AC surface down cracking (longitudinal cracking) vs Subbase Layer thickness

0.0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

7.0 7.5 8.0 8.5 9.0 9.5 10.0 10.5 11.0 11.5 12.0


AC

sur

face

dow

n cr

acki

ng (l

ongi

tudi

nal)

(ft/m

i)


Figure 27: AC surface down cracking vs Subbase layer thickness

The plot of AC surface down cracking versus subbase layer thickness is shown in Figure

27. From the figure it can be seen that the AC surface down cracking decreases with the increase

in the subbase layer thickness. However for the change in subbase layer thickness from 9 to 10

inches and from 11 to 12 inches the AC surface down cracking remains constant. Also the

amount of AC surface down cracking is negligible compared to the maximum allowable limit of

1000 ft/mile of the pavement.

69

27. AC bottom up cracking vs Subbase layer thickness

AC bottom up cracking (alligator cracking) vs Subbase Layer Thickness

10.6

10.8

11

11.2

11.4

11.6

11.8

12

12.2

12.4

7 7.5 8 8.5 9 9.5 10 10.5 11 11.5 12


AC

bot

tom

up

crac

king

(%)


Figure 28: AC bottom up cracking vs Subbase layer thickness

The plot of AC bottom up cracking versus subbase layer thickness is shown in Figure 28.

From the figure it can be concluded, that the AC bottom up cracking decreases with the increase

in the subbase layer thickness. The plot also shows that the changes in subbase layer thickness

have a minor effect on the AC bottom up cracking. For the given pavement system, variation in

the subbase layer thickness from 7 to 12 inches, does not result in exceeding the bottom-up

cracking beyond the allowable maximum limit of 25%.

70

28. AC thermal fracture vs Subbase Layer Thickness

AC thermal fracture vs Subbase Layer Thickness

0.0

0.2

0.4

0.6

0.8

1.0

1.2

7.0 7.5 8.0 8.5 9.0 9.5 10.0 10.5 11.0 11.5 12.0


AC

ther

mal

frac

ture

(ft/m

i)


Figure 29: AC thermal fracture vs Subbase layer thickness

The plot of AC thermal fracture versus subbase layer thickness is shown in Figure 29.

From the figure it can be seen that the change in subbase layer thickness has no effect on the AC

thermal fracture. Thus the AC thermal fracture is independent of the subbase layer thickness.

71

29. Permanent Deformation (AC only) vs Subbase Layer Thickness

Permanent Deformation (AC only) vs Subbase Layer Thickness

0.00

0.05

0.10

0.15

0.20

0.25

0.30

0.35

0.40

7.0 7.5 8.0 8.5 9.0 9.5 10.0 10.5 11.0 11.5 12.0


Perm

anen

t Def

orm

atio

n (A

C o

nly)

(in)


Figure 30: Permanent deformation (AC only) vs Subbase layer thickness

The plot of permanent deformation (AC only) versus subbase layer thickness is shown in

Figure 30. From the figure it can be concluded that the change in subbase layer thickness from 7

to 12 inches has no effect on the Permanent Deformation in the AC layer. The plot also shows,

that for the given pavement configuration and range of subbase layer thickness from 7.0 to 12.0

inches, the permanent deformation in AC layer is more than the allowable maximum limit of

0.25 inches.

72

30. Permanent Deformation (Total Pavement) vs Subbase Layer Thickness

Permanent Deformation (Total Pavement) vs Subbase Layer Thickness

0.685

0.690

0.695

0.700

0.705

0.710

0.715

0.720

0.725

7.0 7.5 8.0 8.5 9.0 9.5 10.0 10.5 11.0 11.5 12.0


Perm

anen

t Def

orm

atio

n (T

otal

Pav

emen

t) (in

)


Figure 31: Permanent deformation (Total Pavement) vs Subbase layer thickness

The plot of permanent deformation (total pavement) versus subbase layer thickness

varying from 7.0 to 12.0 feet is shown in Figure 31. From the figure it can be concluded that

Permanent Deformation in the total pavement decreases with the increase in the subbase layer

thickness. However, it is noted that for the increase in the subbase layer thickness from 7 to 8

inches and from 10 to 11 inches there is no change in the permanent deformation value of the

total pavement. It can also be noted that for the given pavement system and the given range of

73

subbase layer thickness, permanent deformation in the total pavement is less than the maximum

allowable limit of 0.75 inches.

31 Terminal IRI vs Subbase layer Modulus

Terminal IRI vs Subbase Layer Modulus

92.5

92.6

92.7

92.8

92.9

93.0

93.1

93.2

93.3

93.4

25000 26000 27000 28000 29000 30000 31000 32000 33000

Subbase Layer Modulus (psi)

Term

inal

IRI (

in/m

i)

Design Life = 20 yrsAADTT = 1500AC Layer Thickness = 3 inBase Layer Thickness = 6 inBase Layer Modulus = 40,000 psiSubbase Layer Thickness = 9 inSubgrade Modulus = 10,000 psi

Figure 32: Terminal IRI vs Subbase layer modulus

The plot of terminal IRI versus subbase layer modulus varying from 25,000 psi to 33,000

psi is shown in Figure 32. The plot shows that the terminal IRI decreases with the increase in the

subbase layer modulus. Thus, it concludes that the increase in the stiffness of the subbase layer

moduli results in increasing the terminal smoothness of the pavement. An increase in the subbase

layer modulus from 25,000 psi to 33,000 psi results in a decrease of terminal IRI from 93.3 to

74

92.6 in/mile. The initial IRI for a newly constructed pavement is about 75 in/mile and the

maximum acceptable terminal IRI is 200 in/mile. From the plot it appears that for the given

pavement system and the given range of subbase layer thickness the maximum acceptable

terminal IRI is not exceeded. Therefore, change in subbase layer thickness has only a minor

effect on the pavement smoothness.

32. AC surface down cracking vs Subbase Layer Modulus

AC surface down cracking (longitudinal cracking) vs Subbase Layer Modulus

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

25000 26000 27000 28000 29000 30000 31000 32000 33000


AC

sur

face

dow

n cr

acki

ng (f

t/mi)


Figure 33: AC surface down cracking vs Subbase layer modulus

The plot of AC surface down cracking versus varying subbase layer modulus is shown in

Figure 33. The plot shows that the AC surface down cracking decreases with the increase in the

75

subbase layer modulus. It is to be noted that there is no change in the AC surface down cracking

as the subbase layer modulus is increased from 28,000 psi to 29,500 psi. No change in surface

down cracking is also found when the subbase layer modulus is increased from 31,000 psi to

33,000 psi. The maximum value of surface down cracking from the above plot is 0.6 ft/mile for a

subbase layer modulus of 25000 psi and the given pavement system, which is negligible

compared to maximum allowable value of 1000 ft/mile for failure. Thus, it concludes that the

change in subbase layer thickness has a minor effect on the AC surface down cracking.

33. AC bottom up cracking vs Subbase Layer Modulus

AC bottom up cracking (alligator cracking) vs Subbase Layer Modulus

10.4

10.6

10.8

11.0

11.2

11.4

11.6

11.8

12.0

12.2

12.4

25000 26000 27000 28000 29000 30000 31000 32000 33000


AC

bot

tom

up

crac

king

(%)


76

Figure 34: AC bottom up cracking vs Subbase layer modulus

The plot of AC bottom up cracking versus subbase layer modulus varying from 25,000

psi to 33,000 psi is shown in Figure 34. The plot shows that the AC bottom up cracking

decreases with the increase in the subbase modulus. Thus, it concludes that the use of a stiffer

subbase layer will result in reduced AC bottom up cracking. From the plot it also appears that for

the given pavement system a subbase layer modulus of 25,000 psi or a bit lower stiffness can be

still be used, as the maximum allowable limit of 25% bottom up cracking, set for the given

example, is not exceeded even at subbase modulus of 25000 psi, which is the lowest subbase

modulus value in the above analysis.

34. AC thermal fracture vs Subbase Layer Modulus

AC thermal fracture vs Subbase Layer Modulus

0.0

0.2

0.4

0.6

0.8

1.0

1.2

25000 26000 27000 28000 29000 30000 31000 32000 33000


AC

The

rmal

frac

ture

(ft/m

i)


77

Figure 35: AC thermal fracture vs Subbase layer thickness

The plot of AC thermal fracture versus subbase layer modulus is shown in Figure 35.

From the figure it can be seen that there is no change in the AC thermal fracture with the

increase in the subbase layer modulus. Thus AC thermal fracture is independent of the subbase

layer modulus.

35. Permanent Deformation (AC only) vs Subbase Layer Modulus

Permanent Deformation (AC only) vs Subase Layer Modulus

0.00

0.05

0.10

0.15

0.20

0.25

0.30

0.35

0.40

25000 26000 27000 28000 29000 30000 31000 32000 33000


Perm

anen

t Def

orm

atio

n (A

C o

nly)

(in)


78

Figure 36: Permanent deformation (AC only) vs Subbase layer Modulus

The plot of Permanent Deformation (AC only) versus subbase layer modulus is shown in

Figure 36. The plot shows that there is no change in the permanent deformation in the AC layer

with the increase in the subbase modulus. Thus the permanent deformation in the AC layer is

independent of the change in stiffness of subbase layer.

36. Permanent Deformation (Total Pavement) vs Subbase Layer Modulus

Permanent Deformation (Total Pavement) vs Subbase Layer Modulus

0.685

0.690

0.695

0.700

0.705

0.710

0.715

0.720

0.725

25000 26000 27000 28000 29000 30000 31000 32000 33000


Perm

anen

t Def

orm

atio

n (T

otal

Pav

emen

t) (in

)


79

Figure 37: Permanent deformation (Total Pavement) vs Subbase layer thickness

The plot of Permanent Deformation (Total Pavement) versus subbase layer modulus

varying from 25,000 psi to 33,000 psi is shown in Figure 37. The plot shows, that in general the

permanent deformation in the total pavement decreases with the increase in the subbase layer

modulus. However, there is no change in the permanent deformation of the total pavement for

the increase in subbase modulus from 26500 to 28000 psi and from 29500 to 31000 psi. The plot

also reveals that the permanent deformation in total pavement does not exceed the maximum

allowable limit of 0.75 inch set for the given pavement system for the range of subbase layer

modulus used in the analysis.

37. Terminal IRI vs Subgrade Modulus

Terminal IRI vs # Subgrade Modulus

92.7

92.8

92.9

93.0

93.1

93.2

93.3

93.4

93.5

5000 6000 7000 8000 9000 10000 11000 12000 13000

Subgrade Modulus (psi)

Term

inal

IRI (

in/m

i)

Design Life = 20 yrsAADTT = 1500AC Layer Thickness = 3 inBase Layer Thickness = 6 inBase Layer Modulus = 40,000 psiSubbase Layer Thickness = 9 inSubbase Layer Modulus = 28,000 psi

80

Figure 38: Terminal IRI vs Subgrade modulus

The plot of terminal IRI versus subgrade modulus is shown in Figure 38. The plot shows,

that the terminal IRI decreases with the increase in the subgrade modulus. Thus greater the

stiffness of the subgrade, greater will be the smoothness of the pavement at the end of the design

life. For a decrease in the stiffness of the Subgrade Modulus from 5,000 psi to 13,000 psi, the

terminal IRI decreases from 93.4 to 92.8 in/mile. Thus, the change in subgrade modulus does not

have a significant impact on the terminal IRI of the pavement as can be seen from the graph.

38. AC surface down cracking vs Subgrade modulus

AC surface down cracking longitudinal cracking vs Subgrade Modulus

0.0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

5000 6000 7000 8000 9000 10000 11000 12000 13000

Subgrade Modulus

AC

sur

face

dow

n cr

acki

ng (f

t/mi)


81

Figure 39: AC surface down cracking vs Subgrade Modulus

The plot of AC surface down cracking versus subgrade modulus is shown in Figure 39.

From the plot it can be noted that the AC surface down cracking increases with the increase in

the modulus of the subgrade, which is not realistic. Conceptually, a stronger subgrade should

help in reducing the stresses and strains within the pavement and reduce the surface down

cracking. This implies some error in the AASHTO 2002 Design Guide Software pertaining to

the AC surface down cracking model.

39. AC bottom up cracking vs Subgrade modulus

AC bottom up cracking (alligator cracking) vs Subgrade Modulus

10.8

11.0

11.2

11.4

11.6

11.8

12.0

12.2

12.4

12.6

12.8

5000 6000 7000 8000 9000 10000 11000 12000 13000

Subgrade Modulus

AC

bot

tom

up

crac

king

(%)


82

Figure 40: AC bottom up cracking vs Subgrade modulus

The plot of AC bottom up cracking versus subgrade modulus is shown in Figure 40.

From the figure it can be inferred that the AC bottom up cracking decreases with the increase in

the subgrade layer modulus. Thus it implies, that a stronger subgrade helps in limiting the

permanent deformation in the overlying layers and thereby reduces the tensile stress and strains

at the bottom of the AC layer. For an increase in the subgrade modulus from 5,000 psi to 13,500

psi, the AC bottom up cracking decreases from 12.7% to 11.0%.It can be noted that with the

given system of the pavement, and using a subgrade modulus range from 5,000 to 13,500 psi, the

maximum allowable limit of 25% for bottom-up cracking in the pavement is not exceeded.

Therefore, it concludes that the subgrade modulus has a minor effect on AC bottom up cracking.

83

40. AC thermal fracture vs subgrade modulus

AC thermal fracture vs # Subgrade Modulus

0.0

0.2

0.4

0.6

0.8

1.0

1.2

5000 6000 7000 8000 9000 10000 11000 12000 13000


AC

ther

mal

Fra

ctur

e (ft

/mi)


Figure 41: AC thermal fracture vs Subgrade modulus

The plot of AC thermal fracture versus subgrade modulus is shown in Figure 41. From

the figure it can be seen that AC thermal fracture is independent of the subgrade modulus.

84

41. Permanent Deformation (AC only) vs Subgrade modulus

Permanent Deformation (AC only) vs Subgrade Modulus

0.00

0.05

0.10

0.15

0.20

0.25

0.30

0.35

0.40

5000 6000 7000 8000 9000 10000 11000 12000 13000


Perm

anen

t Def

orm

atio

n (A

C o

nly)

(in)


Figure 42: Permanent deformation (AC only) vs Subgrade modulus

The plot of permanent deformation (AC only) versus subgrade modulus is shown in

Figure 42. The plot shows that there is no change in the permanent deformation of the AC layer

with the increase in the subgrade modulus. Thus the Permanent deformation in AC layer is

independent of the subgrade modulus.

85

42. Permanent Deformation (Total Pavement) vs Subgrade modulus

Permanent Deformation (Total Pavement) vs Subgrade Modulus

0.0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1.0

5000 6000 7000 8000 9000 10000 11000 12000 13000


Perm

anen

t Def

orm

atio

n (T

otal

Pav

emen

t) (i

n)


Figure 43: Permanent deformation vs Subgrade modulus

The plot of permanent deformation (Total Pavement) versus subgrade modulus is shown

in Figure 43. The plot shows that the permanent deformation in the total pavement decreases

with the increase in the subgrade modulus. Thus a stiffer subgrade will result in reduced rut

depths in the total pavement structure at the end of the design life. For the given pavement

system, the maximum allowable limit set for permanent deformation of the total pavement is

0.75 inches. From the plot it can noted that the permanent deformation of the total pavement is

less than the maximum allowable limit for subgrade modulus of 8500 psi or greater. Therefore,

86

to limit the total permanent deformation for the given pavement system below the maximum

acceptable value of 0.75 inches, a subgrade modulus of 8,500 psi or greater must be used.

43. Sensitivity of Total Pavement Rutting to Asphalt layer thickness over design period

Sensitivity of Total Pavement Rutting to Asphalt Layer Thickness

0.0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0 10 20 30 40 50 60 70 80 90 100

110

120

130

140

150

160

170

180

190

200

210

220

230

240

250

Pavement Age (months)

Tota

l Rut

ting

(in)

Lay#1 thk 2 "Lay#1 thk 3"Lay#1 thk 6"Lay#1 thk 7"Lay#1 thk 4"Lay#1 thk 5"

Design Life = 20 yrsAADTT = 1500Base Layer Thickness = 6 inBase Layer Modulus = 40,000 psiSubbase Layer Thickness = 9 inSubbase Layer Modulus = 28,000 psi Subgrade Layer Modulus = 10,000 psi

Figure 44: Sensitivity of Total pavement rutting to Asphalt layer thickness

The Figure 44 shows the sensitivity of the Total Pavement Rutting to Asphalt Layer

Thickness over the design period. From the figure it can be seen that the Total pavement Rutting

is highly sensitive to the Asphalt layer thickness. For a change in the asphalt layer thickness from

2 to 7 inches, the Total Pavement Rutting decreases from 0.737 to 0.457 inches. With limiting

value of 0.75 inches, the design of 2 to 7 inches of thickness of asphalt layer is acceptable.

87

44. Sensitivity of Total Pavement Rutting with Base (Layer # 2) Thickness over design period

Sensitivity of Total Pavement Rutting with Base Thickness

0.0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0 10 20 30 40 50 60 70 80 90 100

110

120

130

140

150

160

170

180

190

200

210

220

230

240

250

Pavement Age (mon)

Tota

l Rut

ting

(in) Lay#2 Thk 5"

Lay#2 Thk 6"Lay#2 Thk 7"Lay#2 Thk 8"Lay#2 Thk 9"Lay#2 Thk 10"

Design Life = 20 yrsAADTT = 1500AC Layer Thickness = 3 inBase Layer Modulus = 40,000 psiSubbase Layer Thickness = 9 inSubbase Layer Modulus = 28,000 psi Subgrade Layer Modulus = 10,000 psi

Figure 45: Sensitivity of Total Pavement Rutting with Base thickness

The Figure 45 shows the sensitivity of the Total Pavement Rutting to Base layer

thickness over the design period. From the figure it can be seen that the total pavement layer

rutting is not too sensitive to the base layer thickness. For a change in the base layer thickness

from 5 to 10 inches the Total Pavement Rutting changes from 0.72 to 0.691 inches. With limiting

value of 0.75 inches the design of 5 to 10 inches of thickness of base layer thickness is

acceptable.

88

45. Sensitivity of the total pavement rutting with the Subbase thickness over design period

Sensitivity of Total Pavement Rutting with Subbase Thickness

0.0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0 10 20 30 40 50 60 70 80 90 100

110

120

130

140

150

160

170

180

190

200

210

220

230

240

250

Pavement Age (mon)

Tota

l Rut

ting

(in)

Lay#3 Thk 7"Lay#3 Thk 8"Lay#3 Thk 9"Lay#3 Thk 10"Lay#3 Thk 11"Lay#3 Thk 12"

Design Life = 20 yrsAADTT = 1500AC Layer Thickness = 3 inBase Layer Thickness = 6 inBase Layer Modulus = 40,000 psiSubbase Layer Modulus = 28,000 psi Subgrade Layer Modulus = 10,000 psi

Figure 46: Sensitivity of total pavement rutting with the subbase thickness

The Figure 46 shows the sensitivity of the Total Pavement Rutting to subbase layer

thickness over the design period. From the figure it can be seen that the total pavement layer

rutting is not too sensitive to the subbase layer thickness. For a change in the subbase layer

thickness from 7 to 12 inches the Total Pavement Rutting changes from 0.723 to 0.695 inches.

With the limiting value of 0.75 5inches, the design of 7 to 12 inches of thickness of subbase layer

is acceptable.

89

46. Sensitivity of Terminal IRI with AC layer thickness over design period

Sensitivity of IRI with AC Layer Thicknesses

86

87

88

89

90

91

92

93

94

0 10 20 30 40 50 60 70 80 90 100

110

120

130

140

150

160

170

180

190

200

210

220

230

240

250

Pavement Age (mon)

IRI (

in/m

i)

Lay#1 thk 2"Lay#1 thk 3"Lay#1 thk 4"Lay#1 thk 5"Lay#1 thk 6"Lay#1 thk 7"


Figure 47: Sensitivity of Terminal IRI with AC layer thickness

The Figure 47 shows the sensitivity of the Terminal IRI to AC layer thickness over the

design period of 20 years. From the figure it can be seen that the Terminal IRI changes with

changes in the AC layer thickness. For a change in the AC layer thickness from 2 inches to 3

inches the Terminal IRI increases from 91 to 93, for a change in the AC layer thickness from 3

inches to 4 inches the Terminal IRI reduces to 92.4. With further increase in the AC layer

thickness the Terminal IRI value goes on decreasing. Thus terminal IRI value reaches its peak at

90

3 inches of Asphalt concrete layer. With a limiting value of terminal IRI of 200 in/mile, the

design of 2 to 7 inches of AC layer thickness is acceptable.

47. Sensitivity of Surface Down (Long.) cracking with Asphalt Layer thickness

Sensitivity of Surface Down (Long. ) cracking with Asphalt thickness

0

50

100

150

200

250

300

350

400

450

0 10 20 30 40 50 60 70 80 90 100

110

120

130

140

150

160

170

180

190

200

210

220

230

240

250

Pavement Age (mon)

Surf

ace

Dow

n C

rack

ing

(ft/m

ile)



Figure 48: Sensitivity of Surface down cracking with Asphalt layer thickness

The Figure 48 shows the sensitivity of the surface down longitudinal cracking to AC

layer thickness over the design period of 20 years. From the figure it can be seen that the AC

surface down cracking is highly sensitive to the AC layer thickness. The maximum surface down

cracking of 409 ft/mile occurs for an AC layer thickness of 6 inches at the end of design life of

20 years whereas the minimum surface down cracking of 0.40 ft/mile occurs for an asphalt layer

thickness of 3inches.

91

48. Sensitivity of Bottom up (Alligator) cracking with Asphalt (Layer # 1) thickness over design period

Sensitivity of Bottom up Cracking with AC layer Thickness

0

2

4

6

8

10

12

14

0 50 100 150 200 250 300

Pavement Age (mon)

Bot

tom

up

crac

king

(%)



Figure 49: Sensitivity of Bottom up cracking vs Asphalt thickness

The Figure 49 shows the sensitivity of the bottom up alligator cracking to AC layer

thickness over the design period. From the figure it can be seen that the Bottom up cracking is

highly sensitive to the AC layer thickness. With changes in the AC layer thickness the AC

Bottom up Cracking reaches it peak value of 12.4% at an Asphalt layer thickness of 4 inches and

is at its minimum of 1.4% at an Asphalt layer thickness of 7 inches.

92

49. Sensitivity of AC rutting with AC (layer # 1) thickness over design period

Sensitivity of AC ruttting with AC layer thickness

0.00

0.10

0.20

0.30

0.40

0 50 100 150 200 250 300

Pavement Age (mon)

AC

rutti

ng (i

n) Lay#1 thk 2"Lay#1 thk 3"Lay#1 thk 4"Lay#1 thk 5"Lay#1 thk 6"Lay#1 thk 7"


Figure 50: Sensitivity of AC layer rutting with AC layer thickness

The Figure 50 shows the sensitivity of the AC rutting to AC layer thickness over the

design period. From the figure it can be seen that the AC rutting is highly sensitive to the AC

layer thickness. With the change in AC layer thickness from 2 to 7 inches the AC layer rutting

reaches its maximum value of 0.37 inch at AC layer thickness of 3 inches and its minimum value

of 0.23 inch at a thickness of 7 inches.

93

50. Sensitivity of Terminal IRI with base layer thickness over design period

Sensitivity of IRI with layer # 2 thickness

86

87

88

89

90

91

92

93

94

95

0 50 100 150 200 250 300

Pavement Age (mon)

Term

inal

IRI (

in/m

i)



Figure 51: Sensitivity of Terminal IRI with base layer thickness

The Figure 51 shows the sensitivity of Terminal IRI with base layer thickness over the

design period. From the figure it can be seen that the base layer thickness has a minor effect on

the terminal IRI or the smoothness of the road. Also it can be found that greater the base layer

thickness lesser the Terminal IRI which means more smooth pavements.

94

51. Sensitivity of Bottom Up Cracking with base layer thickness over design period

Sensitivity of Bottom up Cracking with Lay#2 thickness

0

2

4

6

8

10

12

14

16

0 50 100 150 200 250 300

Pavement Age (mon)

Bot

tom

up

Cra

ckin

g (%

)



Figure 52: Sensitivity of Bottom up cracking with base layer thickness

The Figure 52 shows the sensitivity of bottom up cracking with the base layer thickness

over the design period. It can be seen that Bottom up cracking in AC layer is moderately

sensitive to the base layer thickness. Also it can be seen that higher thickness does not ensure

reduced bottom up cracking. From the figure we can see that, at the end of the design life for a

base layer thickness of 7 inches the bottom up cracking is 12.0% whereas for 6 inches it is

11.5%. Similarly for a base layer thickness of 9 inches the bottom up cracking is 10.6% whereas

for 8 inches it is 10.1%.

95

52. Sensitivity of AC rut with base layer thickness over design period

Sensitivity of AC Rut with Lay # 2 thickness

0.00

0.05

0.10

0.15

0.20

0.25

0.30

0.35

0.40

0 50 100 150 200 250 300

Pavement Age (mon)

AC

rut (

in)



Figure 53: Sensitivity of AC rut with base layer thickness

The Figure 53 shows the sensitivity of the AC layer rut with the base layer thickness. It

can be seen that the change in the base layer thickness has negligible influence on the AC layer

rut. For different base layer thickness the AC rut depth is almost constant over the design life of

the pavement.

96

53. Terminal IRI vs AC layer thickness (for Subgrade Modulus of 5000psi and 10000psi)

Layer 1thk vs Terminal IRI for diff. layer # 4 Modulus

87

88

89

90

91

92

93

94

0 1 2 3 4 5 6 7 8

Layer # 1 thickness (in)

Term

inal

IRI (

in/m

i)

Terminal IRI (10000) Terminal IRI (5000)

Design Life = 20 yrsAADTT = 1500Base Layer Thickness = 6 inBase Layer Modulus = 40,000 psiSubbase Layer Thickness = 9 inSubbase Layer Modulus = 28,000 psi Subgrade Layer Modulus = 10k psi, 5k psi

Figure 54: Terminal IRI vs AC layer thickness (for Subgrade Modulus of 5k psi and 10k psi)

In this analysis a graph of Terminal IRI versus AC layer thickness is plotted for two

different values of Subgrade Modulus of 5,000 psi and 10,000 psi. The plot is shown in figure

54. The plot shows that having a greater subgrade modulus does not ensure smaller terminal IRI.

The asphalt layer thickness also plays a role in determining the Terminal IRI of the pavement.

From the figure it can be concluded that it is advisable to use subgrade modulus of 5000 psi if an

asphalt layer thickness of 4 to 5 inches is used in the pavement design for a lower terminal IRI.

97

54. AC surface down cracking vs AC layer thickness (for subgrade modulus of 5000 psi and 10000 psi)

Layer # 1 thickness vs AC surface down crack for diff Lay #4 Modulus

0

50

100

150

200

250

300

350

400

450

0 1 2 3 4 5 6 7 8

Layer # 1 thk (in)

AC

sur

face

dow

n cr

acki

ng (f

t/mi)

AC surface down crack (10000) AC surface down crack (5000)


Figure 55: AC surface down cracking vs AC layer thickness (for subgrade modulus of 5k and

10k psi)

The plot is shown in the Figure 55. The plot shows that higher value of subgrade modulus

results in increased AC surface down cracking. Therefore it is better to use a subgrade modulus

of 5000 psi for the design to control AC surface down cracking especially if the AC layer

thickness used for the pavement design is between 4 to 7 inches.

98

55. AC bottom up cracking vs AC Layer thickness (for subgrade modulus of 5000psi and

10000psi)

AC bot. up crack. vs Layer # 1 thickness for diff. Layer #4 Modulus

0

2

4

6

8

10

12

14

0 1 2 3 4 5 6 7 8

Layer # 1 thk (in)

AC

bot

tom

up

crac

king

(%)

AC bottom up crack. (10000) AC bottom up crack. (5000)


Figure 56: AC bottom up cracking vs AC layer thickness (for subgrade modulus of 5k and 10k

psi)

The plot is shown in Figure 56. The plot shows that greater subgrade modulus does not

necessarily result in smaller AC bottom up cracking. The asphalt layer thickness also has a role

to play. From the figure it can be seen that if an asphalt layer thickness of 4 to 5 inches is used in

the pavement design it is better to have a subgrade modulus of 5,000 psi as against 10,000 psi to

have lower AC bottom up cracking.

99

56. Perm. Deformation (AC only) vs AC layer thickness (for subgrade modulus of 5000psi and

10000psi)

Perm defm. AC vs Layer 1 thk for diff layer #4 Modulus

0.00

0.05

0.10

0.15

0.20

0.25

0.30

0.35

0.40

0 1 2 3 4 5 6 7 8

Layer #1 thickness (in)

Perm

Def

m A

C (i

n)

Perm. Defm AC (10000) Perm. Defm. (5000)


Figure 57: Permanent deformation (AC only) vs AC layer thickness (for subgrade modulus of 5k

and 10k psi)

The plot is shown in Figure 57. The plot shows that greater subgrade modulus does not

necessarily result in smaller Permanent Deformation in AC layer. The asphalt layer thickness

also plays a role in controlling the permanent deformation of the AC layer. From the figure it can

be seen that the subgrade modulus of 5,000 psi results in smaller permanent deformation in AC

100

layer as against a subgrade modulus of 10,000 psi for AC layer thickness between 2 inches to 7

inches.

57. Perm. Deformation Total Pavement vs AC Layer thickness (for subgrade modulus of 5000psi

and 10000 psi)

Permanent Deformation Total Pavement vs Layer #1 thickness for different Layer # 4 Modulus

0.0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1.0

0 1 2 3 4 5 6 7 8

Layer # 1 thickness (in)

Perm

anen

t Def

orm

atio

n To

tal (

in)

Perm. Defm Total Pav. (10000) Perm. Defm Total Pav. (5000)


Figure 58: Perm. Deformation (Total Pavement) vs AC layer thickness ( for subgrade modulus of

5k and 10k psi)

The plot is shown in Figure 58. The plot shows that subgrade modulus of 10,000 psi results in

smaller permanent deformation of the total pavement compared to a subgrade modulus of 5,000

psi for different thicknesses of the AC layer between 2 inches to 7 inches. Thus to control

101

permanent deformation in the total pavement structure it is advisable to use a greater sub-grade

modulus

4.2 Rigid Pavement Sensitivity Analysis

The sensitivity analysis of the rigid pavements is discussed in the following sections.

4.2.1 Jointed Plain Concrete Pavement (JPCP)

To conduct sensitivity analyses on the JPCP pavement the following sample problem was

executed with the design inputs as listed below.

Analysis Parameters

The jointed plain concrete pavement will have a design life of 25 years and initial IRI of

63 in/mile. It is expected that at the end of the design life the pavement will have a terminal IRI

of no more than 200 in/mile at 95 % reliability, transverse cracking of no more than 15% at 90%

reliability and Mean Joint Faulting of no more than 0.15 in at 90% reliability.

Traffic Data

The two-way average annual truck traffic on this pavement is estimated to be 2500 trucks

during the first year of its service. The pavement will be open to traffic in November. There will

be two lanes in the design direction with 90% of the trucks in the design lane. Truck traffic is

equally distributed in both directions and the operational speed is 60 mph. The functional class of

the highway is Interstate. For each class of the vehicle the traffic pattern for monthly and daily

basis remains same throughout the year. The traffic variation over a 24 hour period is assumed to

be same as the national default based on LTPP data. After the initial year the traffic increases at

102

the rate of 4 % compounded annually over the design life of the pavement. The axle load

distribution is assumed to be the same as the national default.

Axle Configuration

The mean of the outerwheel edge is located 18 inches from the edge of the pavement.

The truck lateral wander has a standard deviation of 10 inches and the standard design lane width

is 12 ft. The number of single, tandem, tridem and quad axles for each vehicle class is similar to

national defaults derived from the LTPP. The average axle width is 8.5 ft and the dual tire

spacing is 12 in. The single and dual tire pressure is 120 psi.

Drainage and Surface Properties

The pavement has a cross slope of 2 %, the drainage path length is 12 ft and the surface

shortwave absorptivity is 0.85.

Material Properties

It is anticipated that the temperature and curing conditions will induce a permanent warp

in the pavement equivalent to -10’F. The concrete mix design to be used in the design has level 1

strength tests for the concrete compressive strength, modulus of elasticity and modulus of

rupture. The coefficient of thermal expansion of the mix is assumed to be 6.3 in/in/deg F.

Thermal conductivity and specific heat assumed are 1.25 BTU/hr-ft-‘F and 0.28 BTU/lb-‘F. The

unit weight and poisson’s ratio of the mix are 145 pcf and 0.20 respectively. The concrete mix

designed comprised of type I cement and the aggregate type used for the design is dolomite.

The base materials chosen in this design example include a cement stabilized base and a

crushed stone layer. The cement stabilized base layer has a unit weight of 150 pcf, poisson’s

ratio of 0.20 and an average elastic modulus of 1789845 psi. Thermal conductivity and specific

heat assumed are 1.25 BTU/hr-ft-‘F and 0.28 BTU/lb-‘F. The crushed stone subbase layer has a

103

modulus of 40,000 psi and a PI of 1. 10% of this material passes through #200 sieve and 80%

passes through #4 sieve. The D60 of the crushed stone material is 2mm.The subgrade has a

modulus of 18,000 psi and a plasticity index of the soil is 25.

The initial trial thickness used for the different layers is:

Slab Thickness: 8 in

Cement Stabilized Base Layer thickness: 4 in

Crushed Stone Subbase Layer thickness: 6 in

The following table gives a list of the important parameters used in the sensitivity

analysis.

Table 4: List of parameters used for sensitivity analyses of JPCP pavement

Input Parameters Value For Sensitivity Analyses


2 Two-way AADTT 2500 1500 – 3500


4 Max. Acceptable Terminal IRI 200 in/mile Constant

5 Max. Acceptable Transverse Cracking 15% Constant

6 Max. Acceptable Mean Joint Faulting 0.15 in Constant

7 Slab Thickness 8 in 6 – 12 in

8 Joint Spacing 15 in 10 – 20 in

9 Dowel Bar Diameter 1.5 in 1.0 – 1.5 in

10 Dowel Bar Spacing 12 in 10 – 14 in

11 Base Layer 4 in 4 – 8 in

104

12 Subbase Layer thickness 6 in 4 – 10 in

13 Subgrade Modulus 18,000 psi 8,000 – 24,000 psi

14 Base Modulus 1789845 psi 1250000 – 3000000 psi

To conduct a sensitivity analyses, the effects on the pavement distresses were obtained

with changing the values of one parameter while keeping all other parameters constant. The key

pavement distresses for a JPCP pavement are the Terminal IRI, Transverse Cracking and the

Mean Joint Faulting.

The following is a brief summary of the sensitivity analyses done.

105


Sensitivity of Terminal IRI with AADTT

70

72

74

76

78

80

82

1500 2000 2500 3000 3500

AADTT

Term

inal

IRI (

in/m

ile)

Figure 59: Sensitivity of Terminal IRI with AADTT

The plot of Terminal IRI versus AADTT varying from 1,500 to 3,500, for JPCP is shown

in Figure 59. From the figure it can be seen that terminal IRI increases with the increase in

AADTT. Thus, heavy truck loads result in decreased smoothness of the pavement. An increase

in AADTT from 1,500 to 3,500 resulted in an increase in the Terminal IRI from 71.2 to 80.5

in/mile. The initial IRI for a newly constructed pavement is about 75 in/mile and the maximum

acceptable terminal IRI is 200 in/mile. The plot shows that even for a heavy load of AADTT of

3500, the maximum limit of Terminal IRI is not yet reached. Therefore, AADTT has minor

effect on the Terminal International Roughness Index.

Design Life = 25 years Slab thickness = 8 in Base Layer thickness = 4in Subbase layer thickness = 6 in Slab Modulus = 4,954,161 psi Base Layer Modulus = 1,789,845 psi Subbase Layer Modulus = 40,000 psi Subgrade Modulus = 18,000 psi

106

2. Transverse Cracking vs AADTT

Sensitivity of Transverse Cracking with AADTT

0

0.2

0.4

0.6

0.8

1

1.2

1.4

1500 2000 2500 3000 3500

AADTT

Tran

sver

se C

rack

ing

(%sl

abs

crac

ked)

Figure 60: Sensitivity of Transverse Cracking with AADTT

The plot of Transverse Cracking versus AADTT is shown in the Figure 60. From the

figure it can be seen that the Transverse Cracking in the slab increases with the increase in

AADTT. Thus, increase in the number of heavy truck load passes through the pavement results

in increase of transverse cracking of the pavement. An increase in the AADTT from 1500 to

3500 resulted in the increase of Transverse Cracking of the slab from 0.3 to 1.3%. The maximum

allowable limit for transverse cracking in this example is 15% and any value over 15% percent at

the end of the design life is not acceptable. It can be noted that, even with a heavy load of

AADTT of 3,500 the maximum acceptable value of Transverse cracking is not reached.


107

3. Mean Joint Faulting vs AADTT

Sensitivity of Mean Joint Faulting with AADTT

0

0.005

0.01

0.015

0.02

0.025

0.03

0.035

1500 2000 2500 3000 3500

AADTT

Mea

n Jo

int F

aulti

ng (i

n)

Figure 61: Sensitivity of Mean Joint Faulting with AADTT

The plot of Mean Joint Faulting versus AADTT is shown in the Figure 61. From the

figure it can be seen that the Joint Faulting in the slab increases with the increase in AADTT as

expected. A change in the AADTT from 1500 to 3500 results in the linear increase in the Mean

Joint Faulting from 0.015 to 0.031. The maximum acceptable limit for Mean Joint Faulting

acceptable for this example is 0.15 in. It is interesting to note that, even with a heavy load of

3500 AADTT the maximum limit for Mean Joint Faulting set for the example is not reached.


108

4. Terminal IRI vs Slab Thickness

Sensitivity of Terminal IRI with Slab Thickness

0

20

40

60

80

100

120

140

160

6 7 8 9 10 11 12

Slab Thickness (in)

Term

inal

IRI (

in/m

ile)

Figure 62: Sensitivity of Terminal IRI with Slab thickness

The plot of Terminal IRI versus Slab Thickness is shown in Figure 62. From the figure it

can be seen that the Terminal IRI decreases with the increase in the Slab Thickness. There is

steep drop in the Terminal IRI value as the slab thickness increases from 6 to 7 inches. However

there is gradual decrease in Terminal IRI as the slab thickness increases beyond 7 inches. Using

a slab thickness of 6-inch results in a terminal IRI of 147.8 in/mile whereas, a slab thickness of

7-inch results in a terminal IRI value of 84.4 in/mile. Thus, the slab thickness has a major effect

on the smoothness of the pavement and for the given example a slab thickness of seven or

greater should be used to control Terminal IRI.

Design Life = 25 years AADTT = 2500 Base Layer thickness = 4in Subbase layer thickness = 6 in Slab Modulus = 4,954,161 psi Base Layer Modulus = 1,789,845 psi Subbase Layer Modulus = 40,000 psi Subgrade Modulus = 18,000 psi

109

5. Transverse Cracking vs Slab Thickness

Sensitivity of Transverse Cracking with Slab Thickness

0

10

20

30

40

50

60

70

80

90

100

6 7 8 9 10 11 12

Slab Thickness (in)

Tran

sver

se C

rack

ing

(%)

Figure 63: Sensitivity of Transverse Cracking with Slab Thickness

The plot of Transverse Cracking versus Slab Thickness is shown in Figure 63. From the

figure it can be seen that the Transverse cracking decreases with the increase in the Slab

Thickness. There is a steep decrease in the transverse cracking as the slab thickness is increased

from 6 to 7 inches. The transverse cracking reduces by approx. 10% as the slab thickness is

increased from 7 to 8 inches. Beyond a slab thickness of 8 inches there is very minimal

percentage of Transverse Cracking. Therefore to limit transverse cracking in given pavement

system a minimum thickness of 8 inches should be used.


110

6. Mean Joint Faulting vs Slab Thickness

Sensitivity of Mean Joint Faulting with Slab Thickness

0

0.005

0.01

0.015

0.02

0.025

0.03

6 7 8 9 10 11 12

Slab thickness (in)

Mea

n Jo

int F

aulti

ng (i

n)

Figure 64: Sensitivity of Mean Joint Faulting with Slab Thickness

The plot of Mean Joint Faulting versus Slab Thickness is shown in Figure 64. From the

figure it can be seen that the Mean Joint Faulting decreases as the Slab thickness is increased

from 7 to 12 inches. However, it is interesting to note that the Mean Joint Faulting increases as

the slab thickness is increased from 6 to 7 inches. Though the change is minimal about 0.005

inches, it is not realistic. Conceptually, as the slab thickness is increased one would expect the

Mean Joint Faulting to decrease.


111

7. Terminal IRI vs Joint Spacing

Sensitivity of Terminal IRI with Joint Spacing

0

20

40

60

80

100

120

140

10 11 12 13 14 15 16 17 18 19 20

Joint Spacing (in)

Term

inal

IRI (

in/m

ile)

Figure 65: Sensitivity of Terminal IRI with Joint Spacing

The plot of Terminal IRI with Joint Spacing is shown in Figure 65. The plot shows that

the Terminal IRI decreases as the joint spacing is increased from 10 to 12 inches but it starts to

increase as the joint spacing is increased beyond 12 inches. Even for a high joint spacing of 20

inches the terminal IRI value at the end of the design life is 129.8 in/mile which is less than the

maximum acceptable value of 200 in/mile for failure of the pavement.

Design Life = 25 years AADTT = 2500 Slab Thickness = 8 in Base Layer thickness = 4in Subbase layer thickness = 6 in Slab Modulus = 4,954,161 psi Base Layer Modulus = 1,789,845 psi Subbase Layer Modulus = 40,000 psi Subgrade Modulus = 18,000 psi

112

8. Transverse Cracking vs Joint Spacing

Sensitivity Analysis of Transverse Cracking with Joint Spacing

0

10

20

30

40

50

60

70

10 11 12 13 14 15 16 17 18 19 20

Joint Spacing (in)

Tran

sver

se C

rack

ing

(% s

lab

crac

ked)

Figure 66: Sensitivity of Transverse Cracking with Joint Spacing

The plot of Transverse Cracking versus Joint Spacing is shown in Figure 66. The plot

shows that the Transverse Cracking increases with the increase in the Joint Spacing as expected.

There is no transverse cracking for the joint spacing of 10 in and 12 in. However the Transverse

cracking increases sharply as the joint spacing is increased beyond 12 inches. From the plot it

can be inferred that a joint spacing of 18 or greater cannot be used as it results in transverse

cracking which exceeds the maximum acceptable limit of 15% set for the given pavement

system.


113

9. Mean Joint Faulting vs Joint Spacing

Sensitivity of Mean Joint Faulting with Joint Spacing

0

0.005

0.01

0.015

0.02

0.025

0.03

0.035

0.04

0.045

10 11 12 13 14 15 16 17 18 19 20

Joint Spacing (in)

Mea

n Jo

int F

aulti

ng (i

n)

Figure 67: Sensitivity of Mean Joint Faulting with Joint Spacing

The plot of Mean Joint Faulting versus Joint Spacing is shown in Figure 67. The plot

shows that the Mean Joint Faulting increases with the increase in the Joint Spacing. However it

remains constant as the joint spacing is increased from 10 in to 12 in. Even for a joint spacing as

high as 20 inches the Mean Joint Faulting at the end of design life is only 0.04 inch for the given

pavement system, which is less than the Mean Joint Faulting value of 0.15 inches set for failure.


114

10. Terminal IRI vs Dowel Bar Spacing

Sensitivity of Terminal IRI with Dowel Bar Spacing

0

10

20

30

40

50

60

70

80

10 10.5 11 11.5 12 12.5 13 13.5 14

Dowel Bar Spacing (in)

Term

inal

IRI (

in/m

ile)

Figure 68: Sensitivity of Terminal IRI with Dowel Bar Spacing

The plot of Terminal IRI versus Dowel bar spacing is shown in Figure 68. From the

figure it can be seen that Terminal IRI remains constant with changes in the Dowel Bar Spacing.

The dowel bar spacing affects the concrete bearing stress and also the joint faulting. Terminal

IRI depends upon the development of distresses in the pavement which in turn depend on the

Dowel Bar Spacing. However, since the amount of distresses is low for the given pavement

system, we find no change in the terminal IRI with change in dowel bar spacing.


115

11. Transverse Cracking vs Dowel Bar Spacing

Sensitivity of Transverse Cracking to Dowel Bar Spacing

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

10 10.5 11 11.5 12 12.5 13 13.5 14


Tran

sver

se C

rack

ing

(% s

lab

crac

ked)

Figure 69: Sensitivity of Transverse Cracking with Dowel Bar Spacing

The plot of Transverse Cracking versus Dowel Bar Spacing is shown in Figure 69. From

the figure it can be seen that the Transverse cracking remains constant with changes in the Dowel

Bar Spacing. Conceptually, closer dowel bar spacing should decrease concrete bearing stress and

thereby reduce the subsequent transverse cracking in the pavement. The distresses are relatively

low for the given pavement system, therefore transverse cracking is not too sensitive to the

dowel bar spacing.


116

12. Mean Joint Faulting vs Dowel Bar Spacing

Sensitivity of Mean Joint Faulting with Dowel Bar Spacing

0

0.005

0.01

0.015

0.02

0.025

10 10.5 11 11.5 12 12.5 13 13.5 14


Mea

n Jo

int F

aulti

ng (i

n)

Figure 70: Sensitivity of Mean Joint Faulting with Dowel Bar Spacing

The plot of Mean Joint Faulting versus Dowel Bar Spacing is shown in Figure 70. From

the figure it can be seen that the Mean Joint Faulting remains constant with changes in the Dowel

Bar Spacing for the given pavement system. It can also be noted that, for the given pavement

system and various Dowel Bar Spacing, the mean joint faulting does not exceed the maximum

acceptable limit of 0.15 inches.


117

13. Terminal IRI vs Dowel Bar Diameter

Sensitivity of Terminal IRI with Dowel Bar Diameter

0

20

40

60

80

100

120

140

160

1 1.05 1.1 1.15 1.2 1.25 1.3 1.35 1.4 1.45 1.5

Dowel Bar Diameter (in)

Term

inal

IRI

Figure 71: Sensitivity of Terminal IRI with Dowel Bar Diameter

The plot of Terminal IRI versus Dowel Bar Diameter is shown in Figure 71. From the

figure it can be seen that the Terminal IRI is highly sensitive to the dowel bar diameter. The plot

shows that Terminal IRI decreases with the increase in the dowel bar diameter. Therefore, a

greater Dowel Bar Diameter results in greater smoothness of the pavement over the design life of

the pavement. The dowel bar diameter of 1 inch, results in a terminal IRI value of 141.20 in/mile

at the end of the design life of the pavement, whereas as dowel bar diameter of 1.5 inches results


118

in a terminal IRI value of 76 in/mile. The larger the dowel bar diameter, the lower the concrete

bearing stress and joint faulting which in turn results in lower subsequent terminal IRI.

14. Transverse Cracking vs Dowel Bar Diameter

Sensitivity of Transverse Cracking with Dowel Bar Diameter

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

1 1.05 1.1 1.15 1.2 1.25 1.3 1.35 1.4 1.45 1.5

Dowel Bar Diameter (in)

Tran

sver

se C

rack

ing

(% S

lab

crac

ked)

Figure 72: Sensitivity of Transverse Cracking with Dowel Bar Diameter

The plot of Transverse Cracking versus Dowel Bar Spacing is shown in Figure 72. The

plot shows that, there is no change in the Transverse Cracking of the slab with change in the

dowel bar diameter. Thus, the transverse cracking in the slab is independent of the diameter of

the dowel bar and it mostly affects the joint faulting of the pavement.


119

15. Mean Joint Faulting vs Dowel Bar Diameter

Sensitivity of Mean Joint Faulting with Dowel Bar Diameter

0

0.02

0.04

0.06

0.08

0.1

0.12

0.14

0.16

1 1.05 1.1 1.15 1.2 1.25 1.3 1.35 1.4 1.45 1.5

Dowel Bar Diameter(in)

Mea

n Jo

int F

aulti

ng(in

)

Figure 73: Sensitivity of Mean Joint Faulting with Dowel Bar Diameter

The plot of Mean Joint Faulting versus Dowel Bar Diameter is shown in Figure 73. The

plot shows that the Mean Joint Faulting decreases with the increase in the diameter of the dowel

bar. The Mean Joint Faulting decreases from 0.147 inch to 0.023 inch as the dowel bar diameter

is increased from 1.0 to 1.5 inch. Since, the maximum Mean Joint Faulting value for failure is

0.15 inches at the end of the design life, a dowel bar diameter of greater than 1 inch should be

used for the given pavement system. JPCP joint faulting is highly sensitive to dowel bar diameter

as increase in diameter increases the effective area of the bar relative to the slab thickness,

thereby lowering joint faulting and concrete bearing stress.


120

16. Terminal IRI vs Layer 2 (base layer) thickness

Sensitivity of Terminal IRI with Layer 2 thickness

71.5

72

72.5

73

73.5

74

74.5

75

75.5

76

76.5

4 4.5 5 5.5 6 6.5 7 7.5 8

Layer 2 thickness (in)

Term

inal

IRI (

in/m

ile)

Figure 74: Sensitivity of Terminal IRI with layer 2 (Cement Stabilized base) thickness

The plot of Terminal IRI versus Layer 2 thickness is shown in Figure 74. The plot shows

that the Terminal IRI decreases with the increase in the Layer 2 (base layer) thickness. The

terminal IRI value decreases from 76 to 71.9 as the layer 2 (base thickness) is increased from 4

to 8 inches. Thus, it can be concluded that, terminal IRI is not too sensitive to the thickness of the

cement stabilized base layer of the pavement.

Design Life = 25 years AADTT = 2500 Slab Thickness = 8 in Subbase layer thickness = 6 in Slab Modulus = 4,954,161 psi Base Layer Modulus = 1,789,845 psi Subbase Layer Modulus = 40,000 psi Subgrade Modulus = 18,000 psi

121

17. Transverse Cracking vs Layer 2 (base layer) thickness

Sensitivity of Transverse Cracking with Layer -2 thickness

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

4 4.5 5 5.5 6 6.5 7 7.5 8

Layer 2 Thickness (in)

Tran

sver

se C

rack

ing

(% S

labs

cra

cked

)

Figure 75: Sensitivity of Transverse Cracking with Layer – 2 (Cement Stabilized) thickness

The plot of Transverse Cracking versus Layer 2 (base layer) thickness is shown in Figure

75. The plot shows that the transverse cracking decreases as the Layer 2 (base layer) thickness is

increased from 4 to 7 inches. However, transverse cracking increases as the layer 2 (base layer)

thickness is increased from 7 to 8 inches. This is contradictory as a thicker base layer is expected

to reduce cracking of the pavement. It can also be noted that the transverse cracking remains

constant for base layer thickness of 5 and 6 inches. For the given pavement system, it can be

inferred that the layer 2 (base layer) thickness of 7 inches will result in minimum transverse

cracking of the slab.


122

18. Mean Joint Faulting vs Layer 2 thickness

Sensitivity of Mean Joint Faulting with Layer 2 thickness

0

0.005

0.01

0.015

0.02

0.025

4 4.5 5 5.5 6 6.5 7 7.5 8


Mea

n Jo

int F

aulti

ng (i

n)

Figure 76: Sensitivity of Mean Joint Faulting with Layer 2 (Cement Stabilized) thickness

The plot of Mean Joint Faulting versus Layer 2 thickness is shown in Figure 76. From the

figure it can be seen that the Mean Joint Faulting decreases as the layer 2 (base layer) thickness

increases from 4 to 8 inches. The Mean Joint Faulting decreases from 0.023 to 0.016 inches as

the layer 2 (base) thickness is increased from 4 to 8 in. The Mean Joint Faulting is a critical

factor affecting ride quality. The acceptable level of Mean Joint faulting for the given pavement

system is 0.15 in at the end of the design life. From the figure it can be inferred that, using a

Cement Stabilized Base layer thickness from 4 to 8 inches will not result in Mean Joint Faulting

beyond the acceptable level of 0.15 inches and the pavement will have better ride quality at the

end of the design life.


123

19. Terminal IRI vs Layer 3 (Subbase) thickness

Sensitivity ofTerminal IRI with Layer 3 thickness

75

75.5

76

76.5

77

4 5 6 7 8 9 10


Term

inal

IRI (

in/m

ile)

Figure 77: Sensitivity of Terminal IRI with Layer 3 (Crushed Stone Subbase) thickness

The plot of Terminal IRI versus Layer 3 (subbase layer) thickness is shown in Figure 77.

The plot shows that the Terminal IRI remains constant with the increase in the Layer 3 (subbase)

thickness. However for an increase in the crushed stone layer thickness from 9 to 10 inches there

is almost a negligible decrease in Terminal IRI value from 76 to 75.9 in/mile. From the previous

analyses it can be seen that Terminal IRI is more sensitive to the slab thickness and to base layer

thickness compared to subbase layer thickness. Thus, the change in subbase layer thickness has

only a minor effect on the terminal IRI of the pavement.

Design Life = 25 years AADTT = 2500 Slab Thickness = 8 in Base Layer thickness = 4in Slab Modulus = 4,954,161 psi Base Layer Modulus = 1,789,845 psi Subbase Layer Modulus = 40,000 psi Subgrade Modulus = 18,000 psi

124

20. Transverse Cracking vs Layer 3 (subbase layer) thickness

Sensitivity of Transverse Cracking with Layer-3 thickness

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

4 5 6 7 8 9 10


Tran

sver

se C

rack

ing

Figure 78: Sensitivity of Transverse Cracking with Layer 3 (subbase layer) thickness

The plot of Transverse Cracking versus Layer 3 (subbase layer) thickness is shown in

Figure 78. From the figure it can be seen that the transverse cracking of the slab remains constant

at 0.7 percent with the increase in the subbase layer thickness. Thus, the change in the subbase

layer thickness has no effect on the transverse cracking of the slab.


125

21. Mean Joint Faulting vs Layer 3 (subbase layer) thickness

Sensitivity of Mean Joint Faulting with Layer 3 thickness

0

0.005

0.01

0.015

0.02

0.025

4 5 6 7 8 9 10

Layer 3 Thickness (in)

Mea

n Fa

ultin

g (in

)

Figure 79: Sensitivity of Mean Joint Faulting with Layer 3 (Crushed Stone) thickness

The plot of Mean Joint Faulting versus Layer 3 (subbase layer) thickness is shown in

Figure 79. The plot shows that the Mean Joint Faulting of the slab remains constant with the

change in the layer 3 thickness. Therefore, the Mean Joint Faulting is not sensitive to changes in

the layer 3 (crushed stone) thickness of the pavement.


126

22. Terminal IRI vs Subgrade Modulus

Sensitivity of Terminal IRI with Subgrade Modulus

71

72

73

74

75

76

77

78

79

8000 10000 12000 14000 16000 18000 20000 22000 24000


Term

inal

IRI (

in/m

ile)

Figure 80: Sensitivity of Terminal IRI with Subgrade Modulus

The plot of Terminal IRI versus Subgrade Modulus is shown in Figure 80. From the

figure it can be seen that the Terminal IRI decreases with the increase in the subgrade modulus.

Thus, the use of stiffer subgrade will result in greater smoothness of the pavement at the end of

design life. For an increase in the subgrade modulus from 8000 to 24000 psi the Terminal IRI

decreases from 78.3 to 71.9 in/mile. This change is nominal and therefore using a subgrade with

a higher modulus of 24000 psi instead of a subgrade with lower modulus of 8000 psi will not

make considerable difference given the acceptable terminal IRI for the given pavement system at

the end of design life is 200 in/mile.

Design Life = 25 years AADTT = 2500 Slab Thickness = 8 in Base Layer thickness = 4in Subbase layer thickness = 6 in Slab Modulus = 4,954,161 psi Base Layer Modulus = 1,789,845 psi Subbase Layer Modulus = 40,000 psi

127

23. Transverse Cracking vs Subgrade Modulus

Sensitivity of Transverse Cracking with Subgrade Modulus

0

0.2

0.4

0.6

0.8

1

1.2

8000 10000 12000 14000 16000 18000 20000 22000 24000


Tran

sver

se C

rack

ing

(%sl

abs

crac

ked)

Figure 81: Sensitivity of Transverse Cracking with Subgrade Modulus

The plot of Transverse Cracking versus Subgrade Modulus is shown in Figure 81. The

plot shows that the Transverse Cracking decreases as the subgrade modulus increases from 8,000

psi to 18,000 psi. It remains constant for increase in the subgrade modulus from 18,000 psi to

20,000 psi. However, the transverse cracking increases for an increase in subgrade modulus from

20,000 to 24,000 psi. Thus, a subgrade modulus between 18,000 psi to 20,000 psi will result in

minimum transverse cracking in the pavement. However, the graph is conceptually not realistic

between the subgrade modulus ranges of 20,000 psi to 24,000 psi, as a greater subgrade modulus

is expected to reduce transverse cracking.


128

24. Mean Joint Faulting vs Subgrade Modulus

Sensitivity of Mean Joint Faulting with Subgrade Modulus

0

0.005

0.01

0.015

0.02

0.025

0.03

8000 10000 12000 14000 16000 18000 20000 22000 24000


Mea

n Jo

int F

aulti

ng (i

n)

Figure 82: Sensitivity of Mean Joint Faulting with Subgrade

The plot of Mean Joint Faulting versus Subgrade Modulus is shown in Figure 82. The

plot shows that the Mean Joint Faulting decreases with the increase in the subgrade modulus.

Therefore, a stiffer subgrade will result in reduced Mean Joint Faulting of the pavement. For an

increase in the subgrade modulus from 8000 psi to 24000 psi the Mean Joint Faulting decreases

from 0.027 to 0.015. For the change in subgrade modulus from the 8000 psi to 24000 psi the

corresponding change in the Mean Joint Faulting is not too significant, given the acceptable limit

for Mean Joint Faulting at the end of the design life is 0.15 inches.


129

25. Effect of Tied / Untied PCC shoulder on the Terminal IRI

Effect of Tied/Untied PCC shoulder on Terminal IRI

70

71

72

73

74

75

76

77

Tied PCC Shoulder Not tied to PCC

Term

inal

IRI (

in/m

ile)

Figure 83: Effect of Tied/Untied PCC shoulder on Terminal IRI

The plot comparing the effect of tied/untied PCC shoulder on Terminal IRI is shown in

Figure 83. From the figure it can be seen that an untied PCC shoulder will result in greater

terminal IRI than with tied PCC shoulder. Thus a tied PCC shoulder will ensure a greater

terminal smoothness of the pavement at the end of the design life as they reduce critical

deflections and stresses along the edge.

130

26. Effect of Tied / Untied PCC shoulder on Transverse Cracking

Effect of Tied/Untied PCC Shoulder on Transverse Cracking

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8


Tran

sver

se C

rack

ing

(%Sl

abs

Cra

cked

)

Figure 84: Effect of Tied/Untied PCC shoulder on Transverse Cracking

The plot comparing the effect of tied/untied PCC shoulder on Transverse Cracking is

shown in Figure 84. From the figure it can be seen that an untied PCC shoulder will result in

greater Transverse Cracking compared with tied PCC shoulder at the end of the design life. This

is because tied PCC shoulders reduce the deflections and stresses at the edge of the pavement.

131

27. Effect of Tied / Untied PCC shoulder on Mean Joint Faulting

Effect of Tied/Untied PCC Shoulder on Mean Joint Faulting

0

0.005

0.01

0.015

0.02

0.025


Mea

n Jo

int F

aulti

ng (i

n)

Figure 85: Effect of Tied/Untied PCC shoulder on Mean Joint Faulting

The plot comparing the effect of tied/untied PCC shoulder on Mean Joint Faulting is

shown in Figure 85. From the figure it can be seen that an untied PCC shoulder will result in

greater Mean Joint faulting compared with tied PCC shoulder at the end of the design life.

132

28. Sensitivity of Terminal IRI with Base Modulus

Sensitivity of Terminal IRI (in/mile) with Base Modulus

74

74.5

75

75.5

76

76.5

77

1250000 1500000 1750000 2000000 2250000 2500000 2750000 3000000

Base Modulus (psi)

Term

inal

IRI (

in/m

ile)

Figure 86: Sensitivity of Terminal IRI with Base Modulus

The plot of Terminal IRI vs Base Modulus is shown in Figure 86. From the figure it can

be seen that the Terminal IRI decreases with the increase in the Base Layer Modulus. Thus, the

use of stiffer base will result in greater terminal smoothness of the pavement at the end of the

design life. For an increase in the base layer modulus from 1,250k to 3,000k psi, the Terminal

IRI decreases only from 76.4 to 75.8 in/mile. Thus, it can be concluded that the base layer

modulus has a minor effect on the terminal IRI of the pavement.

Design Life = 25 years AADTT = 2500 Slab Thickness = 8 in Base Layer thickness = 4in Subbase layer thickness = 6 in Slab Modulus = 4,954,161 psi Subbase Layer Modulus = 40,000 psi Subgrade Modulus = 18,000 psi

133

29. Sensitivity of Transverse Cracking with Base Modulus

Sensitivity of Transverse Cracking with Base Layer Modulus

0.60

0.65

0.70

0.75

0.80

0.85

0.90

1250000 1500000 1750000 2000000 2250000 2500000 2750000 3000000


Tran

sver

se C

rack

ing

(%sl

abs

crac

ked)

Figure 87: Sensitivity of Transverse Cracking with Base layer modulus

The plot of Transverse Cracking with Base Modulus is shown in Figure 87. From the

figure it can be seen that the Transverse Cracking decreases from 0.8% to 0.7% as the base layer

modulus is increased from 1,250k to 1,500k psi. However, it remains constant at 0.7% for base

layer modulus beyond 1,500k psi, which is not realistic as it is expected that the transverse

cracking should decrease with the use of stiffer base layers.


134

30. Sensitivity of Mean Joint Faulting with Base Modulus

Sensitivity of Mean Joint Faulting with Base Layer Modulus

0.021

0.0215

0.022

0.0225

0.023

0.0235

0.024

0.0245

0.025

1250000 1500000 1750000 2000000 2250000 2500000 2750000 3000000


Mea

n Jo

int F

aulti

ng (i

n)

Figure 88: Sensitivity of Mean Joint Faulting with Base layer modulus

The plot of Mean Joint Faulting with base modulus is shown in Figure 90. From the

figure it can be seen that the Mean Joint Faulting decreases with the increase in base layer

modulus. For an increase of base layer modulus from 1250k to 3000k psi the Mean Joint

Faulting decreases from 0.024 in to 0.023 in. However, the Mean Joint Faulting remains constant

for an increase in Base Layer Modulus from 1750k to 3000k.


135

4.2.2 Continuous Reinforced Concrete Pavement (CRCP)

To conduct sensitivity analyses on the CRCP pavement the following sample problem

was executed with the design inputs as listed below.

Analysis parameters

The continuous reinforced concrete pavement will have a design of 30 years and initial

IRI of 63 in/mile. It is expected that at the end of the design life the pavement will have a

terminal IRI of no more than 252 in/mile at 95 % reliability and no more than 10 punchouts per

mile at 95% reliability.

Traffic Data

The two-way average annual truck traffic on this pavement is estimated to be 2500 trucks

during the first year of its service. The pavement will be open to traffic in September. There will

be two lanes in the design direction with 90% of the trucks in the design lane. Truck traffic is

equally distributed in both directions and the operational speed is 60 mph. The functional class of

the highway is Interstate. For each class of the vehicle the traffic pattern for monthly and daily

basis remains same throughout the year. The traffic variation over a 24 hour period is assumed to

be same as the national default based on LTPP data. After the initial year the traffic increases at

the rate of 4 % compounded annually over the design life of the pavement. The axle load

distribution is assumed to be the same as the national default.

Axle Configuration

The mean of the outerwheel edge is located 18 inches from the edge of the pavement.

The truck lateral wander has a standard deviation of 10 inches and the standard design lane width

is 12 ft. The number of single, tandem, tridem and quad axles for each vehicle class is similar to

136

national defaults derived from the LTPP. The average axle width is 8.5 ft and the dual tire

spacing is 12 in. The single and dual tire pressures are 120 psi.

Drainage and Surface Properties

The pavement has a cross slope of 2 %, the drainage path length is 12 ft and the surface

shortwave absorptivity is 0.85.

Material Properties

It is anticipated that the temperature and curing conditions will induce a permanent warp

in the pavement equivalent to -10 deg F. The concrete mix design to be used in the design has

level 1 strength tests for the concrete compressive strength, modulus of elasticity and modulus of

rupture. The coefficient of thermal expansion of the mix is assumed to be 6.3 in/in/deg F.

Thermal conductivity and specific heat assumed are 1.25 BTU/hr-ft-‘F and 0.28 BTU/lb-‘F. The

unit weight and poisson’s ratio of the mix are 145 pcf and 0.20 respectively. The concrete mix

designed comprised of type I cement and the aggregate type used for the design is dolomite. The

subgrade in this location has a Mr value of 20,000 psi estimated at optimum moisture conditions

and has a plasticity index of 15.

The initial trial thickness used for the different layers is:

Slab Thickness: 8 in

Asphalt Concrete Base Layer thickness: 4 in

Compacted Subgrade Layer thickness (Subbase): 12 in

The following table gives a list of the important parameters used in the sensitivity analysis.

137

Table 5: List of parameters used in the sensitivity analyses of CRCP pavement

Input Parameters Value For Sensitivity Analyses


2 Two-way AADTT 2500 1500 – 3500


4 Maximum Acceptable Terminal IRI 252 in/mile Constant

5 Maximum Allowable Punchouts (per mile) 10 Constant

7 Slab Thickness 9 in 8 – 12 in

8 Base Layer Thickness 4 in 4 – 8 in

9 Compacted Subgrade Thickness 12 in 10 – 14 in

10 Percent Steel 0.6 0.4 – 0.8

11 Steel Depth 4 in 3 – 4.5 in

12 Subgrade Modulus 20,00 psi 4 – 10 in

138


CRCP - Sensitivity of Terminal IRI with AADTT

0

20

40

60

80

100

120

140

160

1500 1700 1900 2100 2300 2500 2700 2900 3100 3300 3500

AADTT

Term

inal

IRI (

in/m

ile)

Figure 89: Sensitivity of Terminal IRI with AADTT

The plot of Terminal IRI versus AADTT varying from 1500 to 3500 is shown in Figure

89. The plot shows that the terminal IRI increases with the increase in the AADTT. For an

increase in the AADTT from 1500 to 3500 trucks the Terminal IRI increased from 70.6 to 147.2.

Thus, it concludes that the ADDTT has a major effect on the smoothness of the pavement at the

end of the design life. Since the maximum allowable Terminal IRI at the end of the design life is

252 in/mile for the given pavement system, the terminal IRI expected for an AADTT of 3500 is

still within acceptable limits.

Design Life = 30 years Slab Thickness = 9 in Base Layer thickness = 4in Subbase layer thickness = 12 in Slab Modulus = 4,954,161 psi Subbase Layer Modulus = 20,000 psi Subgrade Modulus = 13,000 psi

139

2. Punchouts vs AADTT

CRCP - Sensitivity of Punchouts with AADTT

0

5

10

15

20

25

30

35

40

45

50

1500 1700 1900 2100 2300 2500 2700 2900 3100 3300 3500

AADTT

Punc

hout

s (p

er m

ile)

Figure 90: Sensitivity of Punchouts with AADTT

The plot of punchouts versus AADTT varying from 1500 to 3500 is shown in Figure 90.

The plot shows that the number of punchouts per mile increase with the increase in the AADTT.

For an increase in the AADTT from 1500 to 3500 trucks the number of punchouts per mile

increased from 3.9 to 43. Thus, the AADTT has a major effect on the number of punchouts per

mile of the pavement. Since the maximum allowable number of punchouts set for the given

example is 10 per mile of the pavement at the end of the design life, the given pavement system

can only support an AADTT of approx 1750.

Design Life = 30 years Slab Thickness = 9 in Base Layer thickness = 4in Subbase layer thickness = 12 in Slab Modulus = 4,954,161 psi Subbase Layer Modulus = 20,000 psi Subgrade Modulus = 13,000 psi

140

3. Terminal IRI vs Slab Thickness

Sensitivity of Terminal IRI with Slab Thickness

0

20

40

60

80

100

120

140

160

180

200

8 8.5 9 9.5 10 10.5 11 11.5 12

Slab Thickness (in)

Term

inal

IRI

Figure 91: Sensitivity of Terminal IRI with Slab Thickness

The plot of Terminal IRI versus Slab Thickness is shown in Figure 91. The plot shows

that the terminal IRI decreases with the increase in slab thickness. Thus, it concludes that a

greater slab thickness will ensure smoother roads at the end of the design life of the pavement.

Slab thickness is one of the most critical design features from the standpoint of both cost and

performance. For an increase in the slab thickness from 8 inches to 12 inches the terminal IRI

decreased from 186.8 to 63.4 in/mile. As slab thickness increases, critical bending stresses and

deflections decrease with the consequent increase in smoothness over design life. Since the

acceptable limit for terminal IRI at the end of the design life is 252 in/mile, a slab thickness of 8

Design Life = 30 years AADTT = 2500 Base Layer thickness = 4in Subbase layer thickness = 12 in Slab Modulus = 4,954,161 psi Subbase Layer Modulus = 20,000 psi Subgrade Modulus = 13,000 psi

141

inches can be used for the given pavement provided the criteria for maximum acceptable number

of punchouts is met.

4. Punchouts vs Slab thickness

Sensitivity of Punchouts with Slab Thickness

0

10

20

30

40

50

60

70

8 8.5 9 9.5 10 10.5 11 11.5 12

Slab Thickness (in)

Punc

hout

s (p

er m

ile)

Figure 92: Sensitivity of Punchouts with Slab Thickness

The plot of Punchouts versus Slab thickness is shown in Figure 92. The plot shows that

the number of punchout per mile decreases with the increase in the slab thickness. For an

increase in the slab thickness from 8 to 11 inches the Punchouts per mile decrease from 63.2 to

0.3. For an increase in the slab thickness from 11 to 12 inches the number of punchouts per mile

predicted increase from 0.3 to 2. Thus a slab thickness of 11 inches will result in the minimum

number of punchouts per mile for the given pavement system. It is interesting to note that the

Design Life = 30 years AADTT = 2500 Base Layer thickness = 4in Subbase layer thickness = 12 in Slab Modulus = 4,954,161 psi Subbase Layer Modulus = 20,000 psi Subgrade Modulus = 13,000 psi

142

number of punchouts increases as the slab thickness is increased from 11 to 12 inches. This is not

realistic as with a greater thickness of slab the number of punchouts are expected to decrease.

5. Terminal IRI vs Base Thickness

Sensitivity of Terminal IRI with Base Layer Thickness

118

118.5

119

119.5

120

120.5

121

121.5

122

122.5

123

123.5

4 4.5 5 5.5 6 6.5 7 7.5 8


Term

inal

IRI (

in/m

ile)

Figure 93: Sensitivity of Terminal IRI with Base Layer Thickness

The plot of Terminal IRI versus Base Thickness varying from 4 to 8 inches is shown in

Figure 93. The plot shows that the terminal IRI decreases with the increase in the base thickness.

For an increase in the base thickness from 4 to 8 inches the Terminal IRI decreases from 122.9 to

118.7. Thus the base thickness plays a minor role in the determining the terminal IRI of the

pavement at the end of the design life.

Design Life = 30 years AADTT = 2500 Slab Thickness = 9 in Subbase layer thickness = 12 in Slab Modulus = 4,954,161 psi Subbase Layer Modulus = 20,000 psi Subgrade Modulus = 13,000 psi

143

6. Punchouts vs Base Thickness

Sensitivity of Punchouts with Base layer Thickness

28

28.5

29

29.5

30

30.5

31

4 4.5 5 5.5 6 6.5 7 7.5 8


Punc

hout

s (p

er m

ile)

Figure 94: Sensitivity of Punchouts with Base layer thickness

The plot of CRCP punchouts versus base thickness is shown in Figure 94. From the

figure it can be seen that the number of CRCP punchouts per mile decrease with the increase in

the base layer thickness. For an increase in the base thickness from 4 to 8 inch, the CRCP

punchouts decrease from 30.6 per mile 28.4 per mile. However, for the given range of base

thicknesses the allowable limit of 10 Punchouts per mile for the given pavement system is not

met. Therefore, to control the punchouts the base thickness must be increased beyond 8 inches

for the given pavement system.

Design Life = 30 years AADTT = 2500 Slab Thickness = 9 in Subbase layer thickness = 12 in Slab Modulus = 4,954,161 psi Subbase Layer Modulus = 20,000 psi Subgrade Modulus = 13,000 psi

144

7. Terminal IRI vs Compacted Subgrade Layer thickness

Sensitivity of Terminal IRI with Compacted Subgrade Layer thickness

122

122.5

123

123.5

124

10 10.5 11 11.5 12 12.5 13 13.5 14

Compacted Subgrade Layer Thickness (in)

Term

inal

IRI (

in/m

ile)

Figure 95: Sensitivity of Terminal IRI with Compacted Subgrade layer thickness

The plot of Terminal IRI versus Compacted Subgrade Layer Thickness is shown in

Figure 95. From the figure it can be seen that the terminal IRI remains constant for a compacted

subgrade layer thickness of 10 to11 inches, then decreases marginally for a thickness of 11 to 12

inches and again remains constant beyond a thickness of 12 inches. Thus, it can be concluded

that the Terminal IRI of the pavement is not too sensitive to the Compacted subgrade thickness

of the pavement.

Design Life = 30 years AADTT = 2500 Slab Thickness = 9 in Base Layer thickness = 4in Slab Modulus = 4,954,161 psi Subbase Layer Modulus = 20,000 psi Subgrade Modulus = 13,000 psi

145

8. CRCP punchouts vs Compacted Subgrade Layer thickness

Sensitivity of Punchouts with Compacted Subgrade Thickness

0

5

10

15

20

25

30

35

10 10.5 11 11.5 12 12.5 13 13.5 14

Compacted Subgrade Thickness (in)

Punc

hout

s pe

r mile

Figure 96: Sensitivity of Punchouts with Compacted Subgrade Thickness

The plot of CRCP punchouts versus compacted subgrade layer thickness is shown in

Figure 96. From the figure it can be seen that the number of punchouts remain constant with the

increase in the compacted Subgrade Layer thickness. However, the number of punchouts per

mile is more than the maximum acceptable limit of 10 for the given pavement system.

Design Life = 30 years AADTT = 2500 Slab Thickness = 9 in Base Layer thickness = 4in Slab Modulus = 4,954,161 psi Subbase Layer Modulus = 20,000 psi Subgrade Modulus = 13,000 psi

146

9. Terminal IRI vs Percent Steel

Sensitivity of Terminal IRI with Percent Steel

0

20

40

60

80

100

120

140

160

180

0.4 0.45 0.5 0.55 0.6 0.65 0.7 0.75 0.8

Percent Steel (%)

Term

inal

IRI (

in/m

ile)

Figure 97: Sensitivity of Terminal IRI with Percent Steel

The plot of Terminal IRI versus Percent Steel is shown in Figure 97. From the figure it

can be seen that the terminal IRI decreases with the increase in the percentage of steel used. Steel

is used to control the opening of transverse cracking and it also affects the crack spacing. For an

increase in the percentage of steel used from 0.4 to 0.8 % the terminal IRI decreases from 159.4

to 65.5 in/mile. Thus, the percent of steel used has a major effect on the terminal IRI of the

pavement. For the given pavement system, 0.4% of steel can control the terminal IRI value to

160 in/mile which is less than the maximum acceptable value of 252 in/mile set for the given

pavement system.


147

10. CRCP punchouts vs Percent Steel

Sensitivity of Punchouts with Percent Steel

0

10

20

30

40

50

60

0.4 0.45 0.5 0.55 0.6 0.65 0.7 0.75 0.8

Percent Steel

Punc

hout

s (p

er m

ile)

Figure 98: Sensitivity of Punchouts with Percent Steel

The plot of CRCP punchouts versus Percent Steel is shown in Figure 98. The plot shows

that the number of punchouts decreases with the increase in the percent of steel used. For an

increase in the percent steel used from 0.4 to 0.8 % the number of CRCP punchouts decreases

from 49.2 to 1.3 per mile. The allowable number of punchouts set for the given example is 10

per mile at the end of the design life. In order to meet this criterion the percent steel used should

be 0.7 or greater for the given example. Thus, the percentage of steel used has a significant

effect on the number of CRCP punchouts per mile.


148

11. CRCP Terminal IRI vs Depth of Steel

Sensitivity of Terminal IRI with Steel Depth

0

20

40

60

80

100

120

140

3 3.5 4 4.5

Steel Depth (in)

Term

inal

IRI (

in/m

ile)

Figure 99: Sensitivity of Terminal IRI with Steel Depth

The plot of Terminal IRI versus Depth of Steel is shown in Figure 99. From the figure it

can be seen that the terminal IRI increases with the increase in the depth of steel from the top of

the slab. For an increase in the depth of steel from 3 to 4.5 inches the terminal IRI increases from

86.6 to 131 in/mile. The allowable terminal IRI set for the pavement is 252 in/mile at the end of

the design life, which is not exceeded even by using a steel depth of 4.5 inches from the top of

the slab. However it is advisable to use a smaller steel depth from the top of the slab in order to

have comparatively smoother pavements at the end of the design life. Placing the reinforcement

closer to the surface results in much tighter cracks and fewer punchouts with consequent increase


149

in smoothness of the pavement. Thus, the depth of steel has a significant effect on the terminal

IRI of the pavement.

12. CRCP punchouts vs Depth of Steel

Sensitivity of Punchouts with Steel Depth

0

5

10

15

20

25

30

35

40

3 3.5 4 4.5

Steel Depth (in)

Punc

hout

s (p

er m

ile)

Figure 100: Sensitivity of Punchouts with Steel Depth

The plot of CRCP punchouts versus depth of steel is shown in Figure 100. From the

figure it can be seen that the number of CRCP punchouts increases with the increase in the depth

of steel from the top of the slab. For an increase in the depth of steel from 3 to 4.5 inches the

CRCP punchout increases from 12 to 34.7 per mile. Thus the depth of steel has a significant

effect on the CRCP punchout cracks. Also the since the number of punchouts per mile at the end

of the design life for the given range of steel depths are more than the allowable number of 10


150

punchouts per mile of the pavement, a steel depth smaller than 3 inches from the top of the slab

will be required for the given pavement system.

13. CRCP Terminal IRI vs Uncompacted Subgrade Modulus

Sensitivity of Terminal IRI with Uncompacted Subgrade Modulus

122

122.5

123

123.5

124

10000 11000 12000 13000 14000 15000

Uncompacted Subgrade Layer Modulus (psi)

Term

inal

IRI (

in/m

ile)

Figure 101: Sensitivity of Terminal IRI with Uncompacted Subgrade Modulus

The plot of Terminal IRI with Subgrade Modulus is shown in Figure 101. From the figure

it can be seen that the Terminal IRI decreases from 123.5 to 122.8 in/mile as the Subgrade

Modulus is increased from 10,000 psi to 14,000 psi, However, it increases from 122.8 in/mile to

123.8 in/mile as the Subgrade Modulus is increased from 14,000 psi to 15,000 psi which is

unrealistic and not expected. Overall the uncompacted subgrade has only a minor effect on the

Terminal IRI of the pavement.

Design Life = 30 years AADTT = 2500 Slab Thickness = 9 in Base Layer thickness = 4in Subbase layer thickness = 12 in Slab Modulus = 4,954,161 psi Subgrade Modulus = 13,000 psi

151

14. CRCP Punchouts vs Uncompacted Subgrade Modulus

Sensitivity of CRCP Punchouts with Subgrade Modulus

30

30.2

30.4

30.6

30.8

31

31.2

31.4

31.6

31.8

32

10000 10500 11000 11500 12000 12500 13000 13500 14000 14500 15000

Subgrade Modulus (psi0

Punc

hout

s (p

er m

ile)

Figure 102: Sensitivity of CRCP Punchouts with Subgrade Modulus

The plot of CRCP Punchouts versus Uncompacted Subgrade Modulus is shown in Figure

102. From the figure it can be seen that the number of Punchouts decreases from 30.9 to 30.5 as

the Subgrade Modulus is increased from 10,000 psi to 14,000 psi, however, it increases from

30.5 to 31 as the Subgrade Modulus is increased from 14,000 psi to 15,000 psi. The number of

punchouts for the given range of subgrade modulus at the end of the design life exceeds the

allowable number of punchouts of 10 per mile. Overall, the Subgrade Modulus has only a minor

effect on the number of Punchouts per mile of the pavement.

Design Life = 30 years AADTT = 2500 Slab Thickness = 9 in Base Layer thickness = 4in Subbase layer thickness = 12 in Slab Modulus = 4,954,161 psi Subgrade Modulus = 13,000 psi

152

CHAPTER FIVE: COMPARISON OF METHODS

This section only presents a flexible pavement design using (1993) AASHTO Guide for

Design of Pavement Structure as well as the new AASHTO (2002) design guide. The following

figure illustrates a pavement system with the resilient moduli, layer coefficients, and drainage

coefficients as shown.

Figure 103: Flexible Pavement Design Example

If the predicted Equivalent Single Axle Load equals 4.07 x 106, Reliability (R) = 95%, Standard

Deviation (So) = 0.35, and change in serviceability (ΔPSI) = 2.1. Find the thickness of the

various pavement layers D1, D2 and D3.

Solution:

With E2 = 40,000 psi, the structural number required to protect the base is SN1 = 2.8, as per the

AASHTO design equations

Therefore the thickness of surface course should be:

D1

D2

D3

MR = 10,000 psi

E2 = 40,000 psi a2 = 0.14 m2 = 1.2

E3 = 28,000 psi a3 = 0.08 m3 = 1.2

E1 = 2,500,000 psi a1 = 0.42

153

D1SN1a1

≥

D1

2.80.42

≥

D1 6.7≥

Use D1 = 7 in.

With E3 = 28,000 psi, the structural number required to protect subbase, SN2 = 3.3 as per the

AASHTO design equations for flexible pavements.

The thickness of the layer 2 i.e. base course is given by

D2SN2 a1 D1⋅−

a2 m2⋅≥

D23.2 0.42 7⋅−

0.14 1.2⋅≥

D2 1.55≥

It is generally impractical and uneconomical to use layers of material that are less than

some minimum thickness. Furthermore, the traffic conditions may dictate the use of a certain

minimum level of thickness for stability. The minimum thickness required for base layer is 6

inches for traffic of 2 x 106 to 7 x 106 (ESAL) applications.

Therefore use D2 = 6 in.

For Modulus of subgrade, MR = 10,000 psi, the total structural number, SN3 = 4.8.

The thickness of layer 3 i.e. subbase course is given as:

D3SN3 a1 D1⋅− a2 D2⋅ m3⋅−

a3 m3⋅≥

154

D34.8 0.42 7⋅− 0.14 6⋅ 1.2⋅−

0.08 1.2⋅≥

D3 8.87≥

Use D3 = 9 in.

Therefore, for a 20 year performance period for the given pavement configuration, the thickness

of surface, base and subbase layers used should be 7 in, 6 in and 9 in respectively as per (1993)

AASHTO guide for pavement structures.

If the material properties used in the above example and the design thicknesses obtained

are used for analysis using AASHTO 2002 design guide software, the following distresses are

predicted at the end of the 20 years design life.

1. Terminal IRI (in/mile) = 88 at (99.99% reliability)

2. AC surface down cracking (ft/mile) = 110 at (71.12% reliability)

3. AC bottom up cracking (%) = 1.4 at (99.99% reliability)

4. AC Thermal Fracture (ft/mile) = 1 at (99.99% reliability)

5. AC Permanent Deformation (in) = 0.23 at (59.29% reliability)

6. Permanent Deformation (Total Pavement) (in) = 0.46 in at (99.6 % reliability)

These distresses do not exceed the general maximum allowable limits at the end of 20 years of

design life. It is difficult to draw a comparison between the 1993 AASHTO design procedure and

the new AASHTO 2002 design methodology because of the different inputs involved and

difference in the design approach. The new method is much more comprehensive and

mechanistic as compared to the 1993 AASHTO design equation method.

The equivalent single axle load approach used for traffic characterization in previous

versions of the AASHTO guide for pavement design is not needed for analysis presented in this

155

AASHTO 2002 guide. The 2002 design guide software outputs on a monthly basis the cumulated

number of heavy trucks in the design lane as an overall indicator of the magnitude of truck traffic

loadings. The cumulated number of heavy trucks in the design lane can be considered as the

general indicator of the level of truck traffic.

In addition, in the 1993 AASHTO Guide, the modulus of asphalt concrete is directly used

as input for the design. However, in the 2002 AASHTO Design Guide, the dynamic modulus

(E*) of asphalt concrete is determined by using the various inputs such as the asphalt mix

properties (aggregate gradation), asphalt binder (superpave binder grading, conventional

viscosity grade or conventional penetration grade), volumetric effective binder content, air voids

and reference temperature for master curve development. A master curve of E* versus reduced

time derived from this data defines the behavior of this layer under loading and at various

climatic conditions.

The new 2002 AASHTO Design Guide also addresses the effect of various climatic

conditions on pavement performance. The 1993 AASHTO Design Guide relates the thickness of

the pavement surface layers to serviceability. However pavements may fail prematurely for

reasons not directly related to pavement thickness like rutting, thermal cracking, faulting etc.

These issues are addressed in the new 2002 AASHTO Design Guide.

156

CHAPTER SIX: SUMMARY OF RESULT AND CONCLUSION

The following tables present the results of the sensitivity analysis on pavement distresses

and the percentage change in various pavement distresses for changing the default design input

parameters as listed in the Table 3, 4 and 5.

6.1 Flexible Pavements

6.1.1 Tabulated Results

AADTT 500 1000 1500 2000 2500 3000

Terminal IRI (in/mi) 89.30 91.10 93.00 94.80 96.60 98.50% change inTerminal IRI -3.98 -2.04 0.00 1.94 3.87 5.91AC surface down cracking (ft/mi) 0.10 0.20 0.40 0.70 1.00 1.30% change in AC surface down cracking -75.00 -50.00 0.00 75.00 150.00 225.00AC bottom up cracking (%) 2.80 6.90 11.50 16.20 20.80 25.20% change in AC bottom up cracking -75.65 -40.00 0.00 40.87 80.87 119.13AC thermal fracture (ft/mi) 1.00 1.00 1.00 1.00 1.00 1.00% change in AC thermal fracture 0.00 0.00 0.00 0.00 0.00 0.00Permanent Deformation (AC only) (in) 0.22 0.31 0.37 0.43 0.47 0.52% change in Perm. Deformation (AC only) -40.54 -16.22 0.00 16.22 27.03 40.54Permanent Deformation (Total Pavement) (in) 0.50 0.62 0.71 0.78 0.84 0.89% change in Deformation (Total Pavement) -29.58 -12.68 0.00 9.86 18.31 25.35 Table 6: Percent Change in Pavement Distresses for changes in AADTT

AC layer thickness (in) 2 3 4 5 6 7Terminal IRI (in/mi) 91.00 93.00 92.40 89.60 88.50 88.00% change inTerminal IRI -2.15 0.00 -0.65 -3.66 -4.84 -5.38AC surface down cracking (ft/mi) 4.10 0.40 7.70 161.00 409.00 110.00% change in AC surface down cracking 925.00 0.00 1825.00 40150.00 102150.00 27400.00AC bottom up cracking (%) 3.10 11.50 12.40 5.60 2.80 1.40% change in AC bottom up cracking -73.04 0.00 7.83 -51.30 -75.65 -87.83AC thermal fracture (ft/mi) 1.00 1.00 1.00 1.00 1.00 1.00% change in AC thermal fracture 0.00 0.00 0.00 0.00 0.00 0.00Permanent Deformation (AC only) (in) 0.34 0.37 0.32 0.28 0.25 0.23% change in Perm. Deformation (AC only) -8.11 0.00 -13.51 -24.32 -32.43 -37.84Permanent Deformation (Total Pavement) (in) 0.74 0.71 0.62 0.54 0.50 0.46% change in Deformation (Total Pavement) 4.23 0.00 -12.68 -23.94 -29.58 -35.21 Table 7: Percent Change in Pavement Distresses for changes in AC layer thickness

157

Base layer thickness (in) 5 6 7 8 9 10Terminal IRI (in/mi) 93.90 93.00 93.10 92.40 92.60 92.10% change inTerminal IRI 0.97 0.00 0.11 -0.65 -0.43 -0.97AC surface down cracking (ft/mi) 0.80 0.40 0.40 0.20 0.20 0.20% change in AC surface down cracking 100.00 0.00 0.00 -50.00 -50.00 -50.00AC bottom up cracking (%) 13.90 11.50 12.00 10.10 10.60 9.40% change in AC bottom up cracking 20.87 0.00 4.35 -12.17 -7.83 -18.26AC thermal fracture (ft/mi) 1.00 1.00 1.00 1.00 1.00 1.00% change in AC thermal fracture 0.00 0.00 0.00 0.00 0.00 0.00Permanent Deformation (AC only) (in) 0.37 0.37 0.37 0.37 0.36 0.36% change in Perm. Deformation (AC only) 0.00 0.00 0.00 0.00 -2.70 -2.70Permanent Deformation (Total Pavement) (in) 0.72 0.71 0.71 0.70 0.70 0.69% change in Deformation (Total Pavement) 1.41 0.00 0.00 -1.41 -1.41 -2.82 Table 8: Percent Change in Pavement Distresses for changes in Base Layer thickness

Base Layer Modulus (psi) 38500 39000 40000 40500 41500 42000Terminal IRI (in/mi) 93.30 93.20 93.00 92.80 92.70 92.50% change inTerminal IRI 0.32 0.22 0.00 -0.22 -0.32 -0.54AC surface down cracking (ft/mi) 0.50 0.50 0.40 0.40 0.40 0.40% change in AC surface down cracking 25.00 25.00 0.00 0.00 0.00 0.00AC bottom up cracking (%) 12.40 12.10 11.50 11.20 10.70 10.40% change in AC bottom up cracking 7.83 5.22 0.00 -2.61 -6.96 -9.57AC thermal fracture (ft/mi) 1.00 1.00 1.00 1.00 1.00 1.00% change in AC thermal fracture 0.00 0.00 0.00 0.00 0.00 0.00Permanent Deformation (AC only) (in) 0.37 0.37 0.37 0.37 0.37 0.37% change in Perm. Deformation (AC only) 0.00 0.00 0.00 0.00 0.00 0.00Permanent Deformation (Total Pavement) (in) 0.71 0.71 0.71 0.70 0.70 0.70% change in Deformation (Total Pavement) 0.00 0.00 0.00 -1.41 -1.41 -1.41 Table 9: Percent Change in Pavement Distress for changes in Base Layer Modulus

Subbase Layer Thickness (in) 7 8 9 10 11 12Terminal IRI (in/mi) 93.30 93.20 93.00 92.80 92.80 92.70% change inTerminal IRI 0.32 0.22 0.00 -0.22 -0.22 -0.32AC surface down cracking (ft/mi) 0.70 0.60 0.40 0.40 0.30 0.30% change in AC surface down cracking 75.00 50.00 0.00 0.00 -25.00 -25.00AC bottom up cracking (%) 12.30 12.00 11.50 11.20 10.90 10.70% change in AC bottom up cracking 6.96 4.35 0.00 -2.61 -5.22 -6.96AC thermal fracture (ft/mi) 1.00 1.00 1.00 1.00 1.00 1.00% change in AC thermal fracture 0.00 0.00 0.00 0.00 0.00 0.00Permanent Deformation (AC only) (in) 0.37 0.37 0.37 0.37 0.37 0.37% change in Perm. Deformation (AC only) 0.00 0.00 0.00 0.00 0.00 0.00Permanent Deformation (Total Pavement) (in) 0.72 0.72 0.71 0.70 0.70 0.69% change in Deformation (Total Pavement) 1.41 1.41 0.00 -1.41 -1.41 -2.82 Table 10: Percent Change in Pavement Distress for change in Subbase Layer Thickness

158

Subbase Layer Modulus (psi) 25000 26500 28000 29500 31000 33000Terminal IRI (in/mi) 93.30 93.10 93.00 92.80 92.70 92.60% change inTerminal IRI 0.32 0.11 0.00 -0.22 -0.32 -0.43AC surface down cracking (ft/mi) 0.60 0.50 0.40 0.40 0.30 0.30% change in AC surface down cracking 50.00 25.00 0.00 0.00 -25.00 -25.00AC bottom up cracking (%) 12.20 11.90 11.50 11.20 10.90 10.50% change in AC bottom up cracking 6.09 3.48 0.00 -2.61 -5.22 -8.70AC thermal fracture (ft/mi) 1.00 1.00 1.00 1.00 1.00 1.00% change in AC thermal fracture 0.00 0.00 0.00 0.00 0.00 0.00Permanent Deformation (AC only) (in) 0.37 0.37 0.37 0.37 0.37 0.37% change in Perm. Deformation (AC only) 0.00 0.00 0.00 0.00 0.00 0.00Permanent Deformation (Total Pavement) (in) 0.72 0.71 0.71 0.70 0.70 0.69% change in Deformation (Total Pavement) 1.41 0.00 0.00 -1.41 -1.41 -2.82 Table 11: Percent Change in Pavement Distress for change in Subbase Layer Modulus

Subgrade Modulus (psi) 5000 6500 8500 10000 12000 13500

Terminal IRI (in/mi) 93.40 93.30 93.10 93.00 92.80 92.80% change inTerminal IRI 0.43 0.32 0.11 0.00 -0.22 -0.22AC surface down cracking (ft/mi) 0.10 0.20 0.30 0.40 0.60 0.70% change in AC surface down cracking -75.00 -50.00 -25.00 0.00 50.00 75.00AC bottom up cracking (%) 12.70 12.30 11.80 11.50 11.20 11.00% change in AC bottom up cracking 10.43 6.96 2.61 0.00 -2.61 -4.35AC thermal fracture (ft/mi) 1.00 1.00 1.00 1.00 1.00 1.00% change in AC thermal fracture 0.00 0.00 0.00 0.00 0.00 0.00Permanent Deformation (AC only) (in) 0.37 0.37 0.37 0.37 0.37 0.37% change in Perm. Deformation (AC only) 0.00 0.00 0.00 0.00 0.00 0.00Permanent Deformation (Total Pavement) (in) 0.86 0.79 0.74 0.71 0.68 0.66% change in Deformation (Total Pavement) 21.13 11.27 4.23 0.00 -4.23 -7.04 Table 12: Percent Change in Pavement Distress for change in Subgrade Modulus

From the above tables, the design parameters tested for the sensitivities of the pavement

distresses can be categorized into 4 categories depending on the degree of their effects on the

pavement distresses. These categories are:

1. Parameters having a major effect

2. Parameters having a moderate effect

3. Parameters having a minor effect

4. Parameters having no effect

These design input parameters and their effect pavement distresses are tabulated as follows:

159

Table 13: Sensitivity Analysis of Pavement Distresses Versus Pavement Design Parameters

Pavement Distress Design Parameters

Terminal IRI

AC Surface Down

Cracking

AC Bottom

up Cracking

AC Thermal Cracking

Permanent Deformation

(AC only)

Permanent Deformation

(Total Pavement)

AADTT Minor Minor Major No Major Major AC layer thickness

Minor Major Major No Major Major

Base Layer thickness

Minor Minor Moderate No Minor Minor

Base Layer Modulus

Minor Minor Minor No No Minor

Subbase Layer Thickness


Subbase Layer Modulus


Subgrade Modulus

Minor Minor Minor No No Moderate

6.1.2 Conclusions on Flexible Pavement

The findings and conclusions presented in this section are applicable to all the material

properties, pavement profiles and environmental conditions used in the example problem

discussed in Section 4.1 of this paper.

The sensitivity analysis of the AASHTO 2002 Guide shows that the terminal

international roughness index of the pavement is not too sensitive to the various design

parameters used in the analysis. This is because the terminal IRI depends on the other distresses

that occur in the pavement which in turn depends directly on the pavement design parameters.

Thus, Terminal IRI can be controlled by controlling the other distresses in the pavement like AC

surface down cracking, AC bottom up cracking, rutting and thermal fracture.

160

From the results of sensitivity analysis, it appears that the AC surface down cracking

model is sensitive to all the design parameters considered in the sensitivity analysis in a minor

way. However it is very sensitive to the change in AC layer thickness. It also reveals two

contradicted theories (facts). First, an increase in the subgrade modulus results in an increase in

the AC surface down cracking, which is very unrealistic and not conceptual. With the increase in

stiffness of the subgrade, it is expected that the AC surface cracking should reduce as a stronger

subgrade will provide a greater support to the overlying layers. Second, an increase in the AC

layer thickness from 3 to 6 inches resulted in an increase of the AC surface down cracking,

which is again not realistic pavement function. The AC surface down cracking remains almost

constant when various base layer thicknesses and moduli are used for analysis. Because of these

misleading results, the implementation of AASHTO 2002 guide for flexible pavement design the

AC surface down cracking model must be carefully examined, or the revision of 2002 AASHTO

Design Guide is needed.

From the analysis, it is observed that the AC bottom up cracking is most sensitive to the

parameters of AADTT and AC layer thickness, and there is little effect by the other design

parameters such as the base and subbase layer thickness, and the modulus of the subgrade

material.

It is also observed that the AC bottom up cracking increases with the increase in the AC

layer thickness from 2 to 4 inches but then decreases as the AC layer thickness increases beyond

4 inches. The conclusion that can be drawn from this observation is that for a good pavement

performance, the proper thickness of the AC layer must be as thick as possible. It can be seen

that the greatest potential for AC bottom up cracking is associated with AC thickness in the

ranges of 3 to 5 inches.

161

The permanent deformation of the AC layer is mostly influenced by the AADTT and the

AC layer thickness. Surprisingly, all the results show that the change in base, subbase and

subgrade properties have almost no effect on the pavement deformation which is not quite

realistic. The pavement deformation model should be further reviewed to address this

discrepancy. The permanent deformation of the total pavement is mostly influenced by the

AADTT and the AC layer thickness. The other parameters including the base subbase and

subgrade properties have a minor influence on the total pavement deformation. Permanent

deformation of the total pavement is a product of cumulative ruts occurring in all layers of the

pavement system. From analysis of permanent deformation in total pavement, using the design

inputs shown in Figure 7, a total permanent deformation of 0.89 inches was cumulated by 0.52

inches (58%) of AC layer, 0.07 inches (8%) of base layer and 0.30 inches (36%) of subgrade

layer.

The comparative analysis of the Terminal international roughness index with AC layer

thickness using two types of subgrade modulus shows that using a larger subgrade modulus does

not result in smaller Terminal IRI. Similarly, it was also found that the use of larger subgrade

modulus resulted in greater pavement fatigue cracking. This draws to the conclusion that the

performance of the pavement depends on the combination of the asphalt layer thickness and the

subgrade modulus used for the design.

The results of the sensitivity analysis performed for this study do not completely agree

with the findings of study conducted by Masad (7). This study indicates that the base properties

have only a minor influence on the international roughness index, longitudinal cracking and

practically no influence on permanent deformation of the pavement. This discrepancy might be

162

due to the fact that the pavement design life of 10 years was used by Masad (7) in his study,

whereas in this study the pavement was analyzed based on a design life of 20 years.

The plot of asphalt sub-layers modulus versus time is presented as output by the

AASHTO 2002 Design guide software as shown in the Appendix. This plot appears confusing,

however it is explained clearly in the Design Guide Chapter Two of Part Two (Design Inputs).

The runtime for the analysis of flexible pavements using AASHTO 2002 Design Guide

software was about 24 minutes. The improvement of software execution may be needed.

6.2 Rigid Pavements

6.2.1 Tabulated Results (Jointed Plain Concrete Pavement)

AADTT 1500 2000 2500 3000 3500Terminal IRI (in/mile) 71.200 73.700 76.000 78.300 80.500% change in Terminal IRI -6.316 -3.026 0.000 3.026 5.921Transverse Cracking (%slabs cracked) 0.300 0.500 0.700 1.000 1.300% change in Transverse Cracking -57.143 -28.571 0.000 42.857 85.714Mean Joint Faulting (in) 0.015 0.019 0.023 0.027 0.031% Change in Mean Joint Faulting -34.783 -17.391 0.000 17.391 34.783 Table 14: Percentage change in JPCP pavement distresses for change in AADTT

Slab Thickness (in) 6 7 8 9 10 11 12Terminal IRI (in/mile) 147.800 84.400 76.000 73.800 72.200 70.500 68.900% change in Terminal IRI 94.474 11.053 0.000 -2.895 -5.000 -7.237 -9.342Transverse Cracking (%slabs cracked) 88.800 10.000 0.700 0.100 0.000 0.000 0.000% change in Transverse Cracking 12585.714 1328.571 0.000 -85.714 -100.000 -100.000 -100.000Mean Joint Faulting (in) 0.022 0.025 0.023 0.020 0.017 0.014 0.011% Change in Mean Joint Faulting -4.348 8.696 0.000 -13.043 -26.087 -39.130 -52.174 Table 15: Percent change in JPCP pavement distresses for change in Slab thickness

163

Joint Spacing (ft) 10 12 15 18 20

Terminal IRI (in/mile) 76.500 74.300 76.000 93.400 129.800% change in Terminal IRI 0.658 -2.237 0.000 22.895 70.789Transverse Cracking (%slabs cracked) 0.000 0.000 0.700 19.200 62.200% change in Transverse Cracking -100.000 -100.000 0.000 2642.857 8785.714Mean Joint Faulting (in) 0.017 0.017 0.023 0.033 0.040% Change in Mean Joint Faulting -26.087 -26.087 0.000 43.478 73.913 Table 16: Percent change in JPCP pavement distresses for change in Joint Spacing

Dowel Bar Diameter (in) 1 1.25 1.375 1.5Terminal IRI (in/mile) 141.200 84.800 77.100 76.000% change in Terminal IRI 85.789 11.579 1.447 0.000Transverse Cracking (%slabs cracked) 0.700 0.700 0.700 0.700% change in Transverse Cracking 0.000 0.000 0.000 0.000Mean Joint Faulting (in) 0.147 0.040 0.025 0.023% Change in Mean Joint Faulting 539.130 73.913 8.696 0.000 Table 17: Percentage change in JPCP pavement distresses for change in Dowel bar diameter

Dowel Bar Spacing 10 11 12 13 14Terminal IRI (in/mile) 76.000 76.000 76.000 76.000 76.000% change in Terminal IRI 0.000 0.000 0.000 0.000 0.000Transverse Cracking (%slabs cracked) 0.700 0.700 0.700 0.700 0.700% change in Transverse Cracking 0.000 0.000 0.000 0.000 0.000Mean Joint Faulting (in) 0.023 0.023 0.023 0.023 0.023% Change in Mean Joint Faulting 0.000 0.000 0.000 0.000 0.000 Table 18: Percent Change in JPCP pavement distresses for change in Dowel Bar Spacing

Layer-2 thickness 4 5 6 7 8Terminal IRI (in/mile) 76.000 75.100 74.100 73.000 71.900% change in Terminal IRI 0.000 -1.184 -2.500 -3.947 -5.395Transverse Cracking (%slabs cracked) 0.700 0.600 0.600 0.500 0.600% change in Transverse Cracking 0.000 -14.286 -14.286 -28.571 -14.286Mean Joint Faulting (in) 0.023 0.022 0.020 0.018 0.016% Change in Mean Joint Faulting 0.000 -4.348 -13.043 -21.739 -30.435 Table 19: Percentage change in JPCP pavement distresses for change in Layer – 2 thickness

Layer 3 thickness 4 5 6 7 8 9 10Terminal IRI (in/mile) 76.000 76.000 76.000 76.000 76.000 76.000 75.900% change in Terminal IRI 0.000 0.000 0.000 0.000 0.000 0.000 -0.132Transverse Cracking (%slabs cracked) 0.700 0.700 0.700 0.700 0.700 0.700 0.700% change in Transverse Cracking 0.000 0.000 0.000 0.000 0.000 0.000 0.000Mean Joint Faulting (in) 0.023 0.023 0.023 0.023 0.023 0.023 0.023% Change in Mean Joint Faulting 0.000 0.000 0.000 0.000 0.000 0.000 0.000 Table 20: Percentage change in JPCP pavement distresses for change in Layer – 3 thickness

164

Layer - 4 Modulus 8000 12000 18,000 20,000 24000Terminal IRI (in/mile) 78.300 77.200 76.000 74.800 71.900% change in Terminal IRI 3.026 1.579 0.000 -1.579 -5.395Transverse Cracking (%slabs cracked) 1.000 0.800 0.700 0.700 0.800% change in Transverse Cracking 42.857 14.286 0.000 0.000 14.286Mean Joint Faulting (in) 0.027 0.025 0.023 0.021 0.015% Change in Mean Joint Faulting 17.391 8.696 0.000 -8.696 -34.783 Table 21: Percent Change in JPCP pavement distresses for change in layer 4 Modulus

Tied / Untied PCC Shoulder Tied PCC SNot tied to PCCTerminal IRI (in/mile) 72.400 76.000% change in Terminal IRI -4.737 0.000Transverse Cracking (%slabs cracked) 0.100 0.700% change in Transverse Cracking -85.714 0.000Mean Joint Faulting (in) 0.017 0.023% Change in Mean Joint Faulting -26.087 0.000 Table 22: Percentage change in JPCP pavement distresses for Tied/Untied PCC Shoulder

Base Modulus (psi) 1250000 1500000 1789845 2000000 2500000 3000000Terminal IRI (in/mile) 76.400 76.200 76.000 75.900 75.900 75.800% change in Terminal IRI 0.526 0.263 0.000 -0.132 -0.132 -0.263Transverse Cracking (%slabs cracked) 0.800 0.700 0.700 0.700 0.700 0.700% change in Transverse Cracking 14.286 0.000 0.000 0.000 0.000 0.000Mean Joint Faulting (in) 0.024 0.024 0.230 0.023 0.023 0.023% Change in Mean Joint Faulting -89.565 -89.565 0.000 -96.714 -90.000 -90.000 Table 23: Percentage change in JPCP pavement distresses for change in Base Modulus

Table 24: Sensitivity of pavement distresses with change in JPCP pavement design parameters Pavement Distress Design Parameter Terminal IRI Transverse Cracking Mean Joint Faulting

AADTT Minor Minor Minor Slab Thickness Major Major Moderate Joint Spacing Major Major Moderate

Dowel Bar Spacing No No No Dowel Bar Diameter Major No Major Base Layer Thickness Minor Minor Minor

Subbase Layer thickness Minor No No Subgrade Modulus Minor Minor Minor

Tied/ Untied PCC Shoulder Minor Minor Minor Base Modulus Minor Minor Minor

165

6.2.2 Conclusions on Jointed Plain Concrete Pavement (JPCP)

From the results of the sensitivity analysis of the AASHTO 2002 design guide it can be

concluded that the JPCP pavement distresses: Terminal international roughness index,

Transverse Cracking and Mean Joint Faulting are mostly influenced by the PCC slab thickness,

joint spacing and the dowel bar diameter. The change in subbase thickness has no effect on the

pavement distresses. Similarly change in dowel bar spacing has no effect on the pavement

distresses. These findings are applicable only to the pavement design example discussed in

chapter 4 of this paper.

From the analyses, it can also be concluded that the use of tied PCC shoulder will help in

reducing the transverse cracking of the slab. The joint spacing of greater than 15 ft results in a

sharp increase in the pavement distresses, therefore a joint spacing of 15 ft or less is

recommended to keep the pavement distresses under control. The use of a slab thickness equal to

or greater than 8 inches is recommended as it will reduce the transverse cracking in slab to less

than 1%.

From the Figure 64 it can be seen that Mean Joint Faulting increases from 0.022 inch to

0.025 inch as the slab thickness is increased from 6 to 7 inches. This is not conventional as with

the increase in slab thickness the amount of distresses should decrease. Therefore the distress

model for Mean Joint Faulting must be reviewed to address this discrepancy. With the increase

in base layer thickness from 5 to 6 inches, the predicted transverse cracking remained constant at

0.6% as seen in Figure 75. From the same figure it can be seen that the transverse cracking

increases from 0.5% to 0.6% with the increase in base layer thickness from 7 to 8 inches. This

discrepancy in the model for predicting transverse cracking for JPCP should be reviewed.

166

It can also be noted from Figure 87 and 88 that the Transverse Cracking and Mean Joint

Faulting remain constant with the increase in the base layer modulus from 1.7 Mpsi to 3 Mpsi.

This is not realistic, as it is expected that with a stronger base, the pavement distresses should

decrease. Therefore, the Mean Joint Faulting model also needs to be reviewed further before

implementing the AASHTO 2002 Design Guide for design of JPCP pavements.

6.2.3 Tabulated Results (Continuous Reinforced Concrete Pavement)

AADTT 1500 2000 2500 3000 3500Terminal IRI (in/mile) 70.600 93.000 122.900 138.000 147.200% change in Terminal IRI -42.555 -24.329 0.000 12.286 19.772Number of Punchouts per mile 3.900 15.300 30.600 38.300 43.000% change in number of Punchouts per mile -87.255 -50.000 0.000 25.163 40.523 Table 25: Percentage change in CRCP pavement distresses for change in AADTT

Slab thickness (in) 8 9 10 11 12Terminal IRI (in/mile) 186.800 122.900 66.200 63.700 63.400% change in Terminal IRI 51.993 0.000 -46.135 -48.169 -48.413Number of Punchouts per mile 63.200 30.600 1.600 0.300 2.000% change in number of Punchouts per mile 106.536 0.000 -94.771 -99.020 -93.464 Table 26: Percentage change in CRCP pavement distresses for change in Slab Thickness

Base Layer Thickness (in) 4 5 6 7 8Terminal IRI (in/mile) 122.900 122.000 120.800 120.500 118.700% change in Terminal IRI 0.000 -0.732 -1.709 -1.953 -3.417Number of Punchouts per mile 30.600 30.100 29.500 29.300 28.400% change in number of Punchouts per mile 0.000 -1.634 -3.595 -4.248 -7.190 Table 27: Percentage change in CRCP pavement distresses for change in Base Layer Thickness

Compacted Subgrade Thickness (in) 10 11 12 13 14Terminal IRI (in/mile) 123.000 123.000 122.900 122.900 122.900% change in Terminal IRI 0.081 0.081 0.000 0.000 0.000Number of Punchouts per mile 30.600 30.600 30.600 30.600 30.600% change in number of Punchouts per mile 0.000 0.000 0.000 0.000 0.000 Table 28: Percentage change in CRCP pavement distresses for change in Compacted Subgrade Layer Thickness

167

Percent Steel 0.4 0.5 0.6 0.7 0.8Terminal IRI (in/mile) 159.400 149.900 122.900 67.400 65.500% change in Terminal IRI 29.699 21.969 0.000 -45.159 -46.705Number of Punchouts per mile 49.200 44.400 30.600 2.200 1.300% change in number of Punchouts per mile 60.784 45.098 0.000 -92.810 -95.752 Table 29: Percentage change in CRCP pavement distresses for change in Percent Steel

Steel Depth (in) 3 3.5 4 4.5Terminal IRI (in/mile) 86.600 108.300 122.900 131.000% change in Terminal IRI -29.536 -11.880 0.000 6.591Number of Punchouts per mile 12.000 23.100 30.600 34.700% change in number of Punchouts per mile -60.784 -24.510 0.000 13.399 Table 30: Percentage change in CRCP pavement distresses for change in Steel Depth

Uncompacted Subgrade Modulus (psi) 10000 12000 13000 14000 15000Terminal IRI (in/mile) 123.5 123.1 122.9 122.8 123.8% change in Terminal IRI 0.49 0.16 0.00 -0.08 0.73Number of Punchouts per mile 30.9 30.7 30.6 30.5 31% change in number of Punchouts per mile 0.98 0.33 0.00 -0.33 1.31 Table 31: Percentage change in CRCP pavement distresses for change in Uncompacted Subgrade Modulus

Table 32: Sensitivity of pavement distresses with changes in CRCP pavement design parameters

Pavement Distress Design Parameters Terminal IRI CRCP Punchouts

AADTT Major Major Slab Thickness Moderate Major Base Thickness Minor Minor Compacted Subgrade Layer Thickness

No No

Percent Steel Used Moderate Major Steel Depth Moderate Major Uncompacted Subgrade Modulus

Minor Minor

6.2.4 Conclusions on Continuous Reinforced Concrete Pavement (CRCP)

From the results of the sensitivity analyses, it can be concluded that the CRCP pavement

distresses: terminal IRI and Punchouts are highly sensitive to the design parameters like

AADTT, slab thickness and the percent and the depth of steel used.

168

It is also seen that the change in compacted subgrade layer thickness has almost no effect

on the terminal IRI or the number of punchouts of the pavement.

It is observed from Figure 91 and 92 that, as the slab thickness is increased from 8 to 10

inches there is a sharp decrease in the Terminal IRI and Number of Punchouts, and beyond a slab

thickness of 10 inches the pavement distresses remain almost constant. It can also be seen that

the number of pavement punchouts increases from 0.3 to 2 (per mile) as the slab thickness is

increased from 11 to 12 inches, which is not expected pavement behavior. Therefore the use of

slab thickness of 10 inches or greater is recommended to control the CRCP punchouts to less

than 2 per mile for the given pavement system.

It is also observed that the pavement terminal IRI and CRCP punchouts increase with the

increase in uncompacted subgrade modulus from 13,000 to 14,000 psi which is not realistic.

The CRCP punchout model needs careful review to address the above mentioned

discrepancies before AASHTO 2002 Design Guide can be implemented in practice.

169

APPENDIX: AASHTO 2002 SOFTWARE OUTPUT FOR FLEXIBLE PAVEMENT EXAMPLE

Input Summary: Project T-1

Limit Reliability75

200 901000 90

25 901000 900.25 900.75 90

15002

505060

Class 4 Class 5 Class 6 Class 7 Class 8 Class 9 Class 10 Class 11 Class 12 Class 131.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00

Project: T-1

General Information Description:Design Life 20 yearsBase/Subgrade construction: September, 2005Pavement construction: September, 2005Traffic open: October, 2005Type of design Flexible

Analysis ParametersAnalysis type Probabilistic

Performance CriteriaInitial IRI (in/mi)Terminal IRI (in/mi)AC Surface Down Cracking (Long. Cracking) (ft/500):AC Bottom Up Cracking (Alligator Cracking) (%):AC Thermal Fracture (Transverse Cracking) (ft/mi):Permanent Deformation (AC Only) (in):Permanent Deformation (Total Pavement) (in):

Location: Orlando FLProject ID: Sensitivity Analysis - 1Section ID: 1.1

Principal Arterials - Interstate and Defense RoutesDate: 8/11/2005

Station/milepost format: Feet: 00 + 00Station/milepost begin: 05+00Station/milepost end: 10+00Traffic direction: North bound

Default Input LevelDefault input level Level 3, Default and historical agency values.

Traffic Initial two-way aadtt:Number of lanes in design direction:Percent of trucks in design direction (%):Percent of trucks in design lane (%):Operational speed (mph):

Traffic -- Volume Adjustment FactorsMonthly Adjustment Factors (Level 3, Default MAF)

Vehicle ClassMonth

JanuaryFebruaryMarchAprilMayJuneJuly


1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00

Midnight 2.3% Noon 5.9%1.3% 1:00 am 2.3% 1:00 pm 5.9%8.5% 2:00 am 2.3% 2:00 pm 5.9%2.8% 3:00 am 2.3% 3:00 pm 5.9%0.3% 4:00 am 2.3% 4:00 pm 4.6%7.6% 5:00 am 2.3% 5:00 pm 4.6%

74.0% 6:00 am 5.0% 6:00 pm 4.6%1.2% 7:00 am 5.0% 7:00 pm 4.6%3.4% 8:00 am 5.0% 8:00 pm 3.1%0.6% 9:00 am 5.0% 9:00 pm 3.1%0.3% 10:00 am 5.9% 10:00 pm 3.1%

11:00 am 5.9% 11:00 pm 3.1%

4.0%4.0%4.0%4.0%4.0%4.0%4.0%4.0%4.0%4.0%

18

1012

1.62 0.39 0.00 0.00 2.00 0.00 0.00 0.00 1.02 0.99 0.00 0.00 1.00 0.26 0.83 0.00 2.38 0.67 0.00 0.00

AugustSeptemberOctoberNovemberDecember

Vehicle Class Distribution Hourly truck traffic distribution(Level 3, Default Distribution) by period beginning:

AADTT distribution by vehicle classClass 4Class 5Class 6Class 7Class 8Class 9Class 10Class 11Class 12Class 13

Traffic Growth Factor

Vehicle Class

Growth Rate

GrowthFunction

Class 4 CompoundClass 5 CompoundClass 6 CompoundClass 7 CompoundClass 8 CompoundClass 9 CompoundClass 10 CompoundClass 11 CompoundClass 12 CompoundClass 13 Compound

Traffic -- Axle Load Distribution FactorsLevel 3: Default

Traffic -- General Traffic InputsMean wheel location (inches from the lane marking):Traffic wander standard deviation (in):Design lane width (ft):

Number of Axles per Truck

Quad Axle

Class 4Class 5Class 6

Vehicle Class

Single Axle

Tandem Axle

Tridem Axle

Class 7Class 8


1.13 1.93 0.00 0.00 1.19 1.09 0.89 0.00 4.29 0.26 0.06 0.00 3.52 1.14 0.06 0.00 2.15 2.13 0.35 0.00

8.5

12

120120

51.649.249.2

26.4-80.0911710

Class 9Class 10Class 11Class 12Class 13

Axle ConfigurationAverage axle width (edge-to-edge) outside dimensions,ft):Dual tire spacing (in):

Axle ConfigurationSingle Tire (psi):Dual Tire (psi):

Average Axle SpacingTandem axle(psi):Tridem axle(psi):Quad axle(psi):

Climate icm file:

C:\DG2002\Projects\florida.icmLatitude (degrees.minutes)Longitude (degrees.minutes)Elevation (ft)Depth of water table (ft)

Structure--Design Features

Structure--Layers Layer 1 -- Asphalt concrete

Material type: Asphalt concreteLayer thickness (in): 3

General PropertiesGeneralReference temperature (F°): 70

Volumetric Properties as BuiltEffective binder content (%): 12Air voids (%): 6Total unit weight (pcf): 143

Poisson's ratio: 0.35 (user entered)

Thermal PropertiesThermal conductivity asphalt (BTU/hr-ft-F°): 0.67Heat capacity asphalt (BTU/lb-F°): 0.23

Asphalt MixCumulative % Retained 3/4 inch sieve: 12Cumulative % Retained 3/8 inch sieve: 38Cumulative % Retained #4 sieve: 50


-10 -16 -22 -28 -34 -40 -46

Value11.11.830.51361

% Passing #200 sieve: 4

Asphalt BinderOption: Superpave binder gradingA 10.9800 (correlated)VTS: -3.6800 (correlated)

High temp.°C

Low temperature, °C

46525864707682

Layer 2 -- A-1-aUnbound Material: A-1-aThickness(in): 6

Strength PropertiesInput Level: Level 3Analysis Type: ICM inputs (ICM Calculated Modulus)Poisson's ratio: 0.35Coefficient of lateral pressure,Ko: 0.5Modulus (input) (psi): 40000

ICM InputsGradation and Plasticity IndexPlasticity Index, PI: 1Passing #200 sieve (%): 3Passing #4 sieve (%): 20D60 (mm): 8

Calculated/Derived ParametersMaximum dry unit weight (pcf): 122.2 (derived)Specific gravity of solids, Gs: 2.66 (derived)Saturated hydraulic conductivity (ft/hr): 263 (derived)Optimum gravimetric water content (%): 11.1 (derived)Calculated degree of saturation (%): 82 (calculated)

Soil water characteristic curve parameters: Default values

Parametersabc

Hr.

Layer 3 -- A-2-5Unbound Material: A-2-5


Value12.61.580.534412

Thickness(in): 9


ICM InputsGradation and Plasticity IndexPlasticity Index, PI: 2Passing #200 sieve (%): 20Passing #4 sieve (%): 80D60 (mm): 0.1

Calculated/Derived ParametersMaximum dry unit weight (pcf): 121.9 (derived)Specific gravity of solids, Gs: 2.68 (derived)Saturated hydraulic conductivity (ft/hr): 0.000866 (derived)Optimum gravimetric water content (%): 11.7 (derived)Calculated degree of saturation (%): 83.9 (calculated)


Parametersabc

Hr.

Layer 4 -- A-7-6Unbound Material: A-7-6Thickness(in): Semi-infinite


ICM InputsGradation and Plasticity IndexPlasticity Index, PI: 40Passing #200 sieve (%): 90Passing #4 sieve (%): 99D60 (mm): 0.01

Calculated/Derived ParametersMaximum dry unit weight (pcf): 91.3 (derived)Specific gravity of solids, Gs: 2.77 (derived)Saturated hydraulic conductivity (ft/hr): 3.25e-005 (derived)Optimum gravimetric water content (%): 28.8 (derived)


Value750

0.9110.77247500

0.004323.94921.281

-3.44881.56060.4791

5

11

1.673

1.35

73.501000

1

Calculated degree of saturation (%): 89.4 (calculated)


Parametersabc

Hr.

Distress Model Calibration Settings - Flexible AC Fatigue Level 3 (Nationally calibrated values)

k1k2k3

AC Rutting Level 3 (Nationally calibrated values)k1k2k3

Standard Deviation Total Rutting (RUT):

0.1587*POWER(RUT,0.4579)+0.001

Thermal Fracture Level 3 (Nationally calibrated values)k1

Std. Dev. (THERMAL): 0.2474 * THERMAL + 10.619

CSM Fatigue Level 3 (Nationally calibrated values)k1k2

Subgrade Rutting Level 3 (Nationally calibrated values)Granular:

k1Fine-grain:

k1

AC CrackingAC Top Down Cracking

C1 (top)C2 (top)C3 (top)C4 (top)

Standard Deviation (TOP) 200 + 2300/(1+exp(1.072-2.1654*log(TOP+0.0001)))

AC Bottom Up CrackingC1 (bottom)


106000

1101000

0.04630.001190.18340.003840.007360.001150.387

0.0099950.0005180.0023518.360.96940.292

0.007320.076470.0001450.008420.0002120.229

C2 (bottom)C3 (bottom)C4 (bottom)

Standard Deviation (TOP) 32.7 + 995.1 /(1+exp(2-2*log(BOTTOM+0.0001)))

CSM CrackingC1 (CSM)C2 (CSM)C3 (CSM)C4 (CSM)

Standard Deviation (CSM) CTB*1

IRIIRI Flexible Pavements with GB

C1 (GB)C2 (GB)C3 (GB)C4 (GB)C5 (GB)C6 (GB)Std. Dev (GB)

IRI Flexible Pavements with ATBC1 (ATB)C2 (ATB)C3 (ATB)C4 (ATB)C5 (ATB)Std. Dev (ATB)

C4 (CSM)C5 (CSM)Std. Dev (CSM)

IRI Flexible Pavements with CSMC1 (CSM)C2 (CSM)C3 (CSM)

Reliablity Summary: Project T-1

Distress Target

Reliablity Target

Distress Predicted

ReliabilityPredicted Acceptable

200 90 93 99.999 Pass

1000 90 0.4 99.93 Pass

25 90 11.5 87.63 Fail

1000 90 1 99.999 Pass0.25 90 0.37 11.83 Fail0.75 90 0.71 62.54 Fail

Project: T-1Reliability Summary

Performance Criteria

Terminal IRI (in/mi)

Permanent Deformation (Total Pavement) (in):

AC Surface Down Cracking (Long. Cracking) (ft/500):AC Bottom Up Cracking (Alligator Cracking) (%):AC Thermal Fracture (Transverse Cracking) (ft/mi):Permanent Deformation (AC Only) (in):

Predicted distress: Project T-1

mo yr1 0.08 October 0 0.0061 0 0.025 0.15 86.6 11414 118.192 0.17 November 0 0.0146 0 0.031 0.173 86.6 22828 118.213 0.25 December 0 0.0236 0 0.035 0.187 86.6 34242 118.234 0.33 January 0 0.0337 0 0.038 0.198 86.7 45656 118.255 0.42 February 0 0.0451 0 0.041 0.208 86.7 57070 118.276 0.5 March 0 0.0583 0 0.047 0.22 86.7 68484 118.297 0.58 April 0 0.0722 0 0.051 0.229 86.7 79898 118.318 0.67 May 0 0.0878 0 0.057 0.241 86.7 91313 118.339 0.75 June 0 0.105 0 0.065 0.253 86.8 102727 118.3510 0.83 July 0 0.123 0 0.073 0.267 86.8 114141 118.3711 0.92 August 0 0.141 0 0.08 0.277 86.8 125555 118.412 1 September 0 0.16 0 0.084 0.285 86.8 136969 118.4213 1.08 October 0 0.178 0 0.087 0.29 86.8 148839 118.4414 1.17 November 0 0.195 0 0.088 0.294 86.9 160710 118.4615 1.25 December 0 0.209 0 0.089 0.296 86.9 172581 118.4716 1.33 January 0 0.224 0 0.09 0.299 86.9 184451 118.4917 1.42 February 0 0.238 0 0.09 0.301 86.9 196322 118.5118 1.5 March 0.01 0.254 0 0.091 0.304 86.9 208193 118.5219 1.58 April 0.01 0.273 0 0.093 0.308 86.9 220063 118.5420 1.67 May 0.01 0.294 0 0.097 0.314 87 231934 118.5621 1.75 June 0.01 0.316 0 0.103 0.322 87 243804 118.5822 1.83 July 0.01 0.34 0 0.11 0.331 87 255675 118.6123 1.92 August 0.01 0.365 0 0.115 0.339 87 267546 118.6324 2 September 0.01 0.388 0 0.118 0.343 87.1 279416 118.6525 2.08 October 0.01 0.412 0 0.12 0.347 87.1 291762 118.6726 2.17 November 0.01 0.434 0 0.122 0.35 87.1 304107 118.6927 2.25 December 0.01 0.454 0 0.123 0.352 87.1 316453 118.7128 2.33 January 0.01 0.472 0 0.123 0.353 87.1 328798 118.7329 2.42 February 0.01 0.49 0 0.124 0.355 87.1 341144 118.7430 2.5 March 0.01 0.51 0 0.125 0.357 87.2 353489 118.7631 2.58 April 0.01 0.534 0 0.127 0.36 87.2 365834 118.7832 2.67 May 0.01 0.56 0 0.129 0.364 87.2 378180 118.833 2.75 June 0.01 0.586 0 0.132 0.368 87.2 390525 118.8334 2.83 July 0.01 0.614 0 0.135 0.373 87.3 402871 118.8535 2.92 August 0.01 0.643 0 0.138 0.378 87.3 415216 118.8736 3 September 0.01 0.671 0 0.141 0.382 87.3 427562 118.8937 3.08 October 0.01 0.698 0 0.142 0.384 87.3 440401 118.9138 3.17 November 0.02 0.722 0 0.143 0.386 87.3 453240 118.9339 3.25 December 0.02 0.742 0 0.144 0.387 87.4 466079 118.9540 3.33 January 0.02 0.761 0 0.144 0.388 87.4 478919 118.9741 3.42 February 0.02 0.781 0 0.144 0.39 87.4 491758 118.9842 3.5 March 0.02 0.806 0 0.145 0.391 87.4 504597 11943 3.58 April 0.02 0.833 0 0.147 0.393 87.4 517437 119.0244 3.67 May 0.02 0.863 0 0.149 0.397 87.4 530276 119.0545 3.75 June 0.02 0.894 0 0.151 0.4 87.5 543115 119.0746 3.83 July 0.02 0.926 0 0.154 0.404 87.5 555954 119.0947 3.92 August 0.02 0.958 0 0.157 0.408 87.5 568794 119.1148 4 September 0.02 0.99 0 0.159 0.411 87.5 581633 119.1449 4.08 October 0.02 1.02 0 0.16 0.413 87.6 594986 119.1650 4.17 November 0.02 1.05 0 0.161 0.414 87.6 608339 119.1851 4.25 December 0.03 1.07 0 0.161 0.415 87.6 621691 119.1952 4.33 January 0.03 1.08 0 0.161 0.416 87.6 635044 119.2153 4.42 February 0.03 1.11 0 0.162 0.417 87.6 648397 119.2354 4.5 March 0.03 1.14 0 0.163 0.419 87.6 661750 119.2555 4.58 April 0.03 1.17 0 0.164 0.421 87.7 675103 119.2756 4.67 May 0.03 1.2 0 0.165 0.423 87.7 688456 119.2957 4.75 June 0.03 1.23 0 0.168 0.426 87.7 701808 119.3158 4.83 July 0.03 1.27 0 0.17 0.429 87.7 715161 119.3459 4.92 August 0.03 1.31 0 0.173 0.433 87.8 728514 119.3660 5 September 0.03 1.34 0 0.176 0.437 87.8 741867 119.3961 5.08 October 0.03 1.38 0 0.177 0.439 87.8 755754 119.4162 5.17 November 0.03 1.41 0 0.178 0.441 87.8 769641 119.43

Heavy Trucks(cumulative)

IRI atReliability

(in/mi)


Pavementage

Month

LogitudinalCracking

(ft/mi)

AlligatorCracking

(%)

TransverseCracking

(ft/mi)

SubtotalAC Rutting

(in)

TotalRutting

(in)IRI

(in/mi)


63 5.25 December 0.04 1.43 0 0.178 0.442 87.8 783528 119.4564 5.33 January 0.04 1.46 0 0.179 0.443 87.9 797415 119.4765 5.42 February 0.04 1.49 0 0.179 0.444 87.9 811302 119.4966 5.5 March 0.04 1.52 0 0.181 0.446 87.9 825189 119.5167 5.58 April 0.04 1.56 0 0.181 0.447 87.9 839076 119.5368 5.67 May 0.04 1.59 0 0.183 0.45 88 852963 119.5669 5.75 June 0.04 1.63 0 0.185 0.453 88 866850 119.5870 5.83 July 0.04 1.67 0 0.188 0.456 88 880736 119.6171 5.92 August 0.04 1.71 0 0.191 0.46 88 894623 119.6372 6 September 0.04 1.75 0 0.192 0.462 88 908510 119.6673 6.08 October 0.05 1.79 0 0.193 0.464 88.1 922953 119.6874 6.17 November 0.05 1.82 0 0.194 0.465 88.1 937395 119.775 6.25 December 0.05 1.85 0 0.194 0.466 88.1 951838 119.7276 6.33 January 0.05 1.87 0 0.195 0.466 88.1 966280 119.7477 6.42 February 0.05 1.9 0 0.195 0.467 88.1 980723 119.7578 6.5 March 0.05 1.93 0 0.195 0.468 88.2 995165 119.7779 6.58 April 0.05 1.96 0 0.196 0.469 88.2 1009610 119.880 6.67 May 0.05 2 0 0.198 0.472 88.2 1024050 119.8281 6.75 June 0.05 2.05 0 0.201 0.476 88.2 1038490 119.8582 6.83 July 0.06 2.1 0 0.204 0.48 88.3 1052930 119.8883 6.92 August 0.06 2.14 0 0.207 0.483 88.3 1067380 119.984 7 September 0.06 2.19 0 0.209 0.486 88.3 1081820 119.9385 7.08 October 0.06 2.23 0 0.21 0.488 88.3 1096840 119.9686 7.17 November 0.06 2.27 0 0.211 0.489 88.4 1111860 119.9887 7.25 December 0.06 2.3 0 0.211 0.49 88.4 1126880 12088 7.33 January 0.06 2.33 0 0.212 0.491 88.4 1141900 120.0289 7.42 February 0.06 2.36 0 0.212 0.491 88.4 1156920 120.0490 7.5 March 0.07 2.39 0 0.213 0.492 88.4 1171940 120.0691 7.58 April 0.07 2.44 0 0.214 0.494 88.5 1186960 120.0892 7.67 May 0.07 2.48 0 0.215 0.496 88.5 1201980 120.1193 7.75 June 0.07 2.53 0 0.217 0.498 88.5 1217000 120.1494 7.83 July 0.07 2.58 0 0.219 0.501 88.5 1232020 120.1795 7.92 August 0.07 2.63 0 0.221 0.504 88.6 1247040 120.1996 8 September 0.07 2.67 0 0.223 0.506 88.6 1262060 120.2297 8.08 October 0.07 2.72 0 0.224 0.508 88.6 1277680 120.2598 8.17 November 0.08 2.75 0 0.225 0.509 88.6 1293300 120.2799 8.25 December 0.08 2.78 0 0.225 0.509 88.7 1308920 120.29100 8.33 January 0.08 2.82 0 0.225 0.51 88.7 1324540 120.31101 8.42 February 0.08 2.85 0 0.225 0.511 88.7 1340170 120.33102 8.5 March 0.08 2.89 0 0.226 0.512 88.7 1355790 120.35103 8.58 April 0.08 2.93 0 0.227 0.513 88.8 1371410 120.38104 8.67 May 0.09 2.98 0 0.228 0.515 88.8 1387030 120.4105 8.75 June 0.09 3.03 0 0.23 0.517 88.8 1402650 120.43106 8.83 July 0.09 3.08 0 0.232 0.52 88.8 1418270 120.46107 8.92 August 0.09 3.13 0 0.234 0.522 88.9 1433890 120.49108 9 September 0.09 3.18 0 0.235 0.525 88.9 1449510 120.52109 9.08 October 0.09 3.23 0 0.236 0.526 88.9 1465760 120.54110 9.17 November 0.09 3.27 0 0.237 0.527 88.9 1482000 120.57111 9.25 December 0.1 3.3 0 0.237 0.527 89 1498250 120.59112 9.33 January 0.1 3.33 0 0.237 0.528 89 1514500 120.6113 9.42 February 0.1 3.37 0 0.238 0.529 89 1530740 120.63114 9.5 March 0.1 3.41 0 0.238 0.53 89 1546990 120.65115 9.58 April 0.1 3.46 0 0.239 0.531 89 1563230 120.68116 9.67 May 0.1 3.5 0 0.24 0.532 89.1 1579480 120.7117 9.75 June 0.11 3.56 0 0.242 0.535 89.1 1595720 120.73118 9.83 July 0.11 3.62 0 0.244 0.537 89.1 1611970 120.77119 9.92 August 0.11 3.67 0 0.246 0.54 89.2 1628220 120.8120 10 September 0.11 3.73 0 0.248 0.543 89.2 1644460 120.82121 10.1 October 0.11 3.78 0 0.25 0.544 89.2 1661360 120.85122 10.2 November 0.11 3.82 0 0.25 0.545 89.2 1678250 120.88123 10.3 December 0.12 3.86 0 0.25 0.546 89.3 1695150 120.9124 10.3 January 0.12 3.9 0 0.251 0.547 89.3 1712040 120.92125 10.4 February 0.12 3.94 0 0.251 0.548 89.3 1728940 120.95126 10.5 March 0.12 3.99 0 0.252 0.549 89.3 1745840 120.97127 10.6 April 0.12 4.04 0 0.253 0.55 89.4 1762730 121128 10.7 May 0.12 4.1 0 0.254 0.552 89.4 1779630 121.03129 10.8 June 0.13 4.16 0 0.256 0.554 89.4 1796520 121.06


130 10.8 July 0.13 4.22 0 0.258 0.557 89.4 1813420 121.09131 10.9 August 0.13 4.28 0 0.26 0.56 89.5 1830310 121.12132 11 September 0.13 4.34 0 0.262 0.562 89.5 1847210 121.15133 11.1 October 0.13 4.39 0 0.263 0.563 89.5 1864780 121.2134 11.2 November 0.14 4.44 0 0.263 0.564 89.6 1882350 121.21135 11.3 December 0.14 4.47 0 0.263 0.564 89.6 1899920 121.23136 11.3 January 0.14 4.51 0 0.264 0.565 89.6 1917490 121.26137 11.4 February 0.14 4.55 0 0.264 0.565 89.6 1935070 121.27138 11.5 March 0.14 4.59 0 0.264 0.566 89.6 1952640 121.3139 11.6 April 0.15 4.64 0 0.265 0.567 89.7 1970210 121.33140 11.7 May 0.15 4.7 0 0.266 0.569 89.7 1987780 121.36141 11.8 June 0.15 4.77 0 0.269 0.572 89.7 2005350 121.39142 11.8 July 0.15 4.84 0 0.272 0.576 89.8 2022920 121.44143 11.9 August 0.15 4.9 0 0.274 0.578 89.8 2040490 121.47144 12 September 0.16 4.96 0 0.276 0.58 89.8 2058070 121.5145 12.1 October 0.16 5.02 0 0.277 0.582 89.9 2076340 121.53146 12.2 November 0.16 5.08 0 0.278 0.583 89.9 2094610 121.56147 12.3 December 0.16 5.13 0 0.278 0.584 89.9 2112890 121.59148 12.3 January 0.16 5.17 0 0.278 0.584 89.9 2131160 121.62149 12.4 February 0.17 5.21 0 0.279 0.585 90 2149440 121.62150 12.5 March 0.17 5.26 0 0.279 0.586 90 2167710 121.65151 12.6 April 0.17 5.31 0 0.28 0.587 90 2185990 121.68152 12.7 May 0.17 5.38 0 0.281 0.589 90 2204260 121.71153 12.8 June 0.17 5.44 0 0.282 0.59 90.1 2222530 121.77154 12.8 July 0.18 5.51 0 0.285 0.593 90.1 2240810 121.79155 12.9 August 0.18 5.58 0 0.286 0.595 90.1 2259080 121.82156 13 September 0.18 5.65 0 0.288 0.597 90.2 2277360 121.85157 13.1 October 0.18 5.71 0 0.289 0.598 90.2 2296360 121.88158 13.2 November 0.19 5.76 0 0.289 0.599 90.2 2315370 121.91159 13.3 December 0.19 5.81 0 0.29 0.6 90.3 2334370 121.94160 13.3 January 0.19 5.85 0 0.29 0.6 90.3 2353380 121.97161 13.4 February 0.19 5.89 0 0.29 0.601 90.3 2372380 121.98162 13.5 March 0.2 5.95 0 0.291 0.602 90.3 2391390 122.01163 13.6 April 0.2 6.01 0 0.291 0.603 90.3 2410390 122.04164 13.7 May 0.2 6.07 0 0.293 0.604 90.4 2429400 122.09165 13.8 June 0.2 6.14 0 0.294 0.606 90.4 2448400 122.13166 13.8 July 0.2 6.21 0 0.296 0.609 90.5 2467410 122.16167 13.9 August 0.21 6.29 0 0.298 0.611 90.5 2486410 122.19168 14 September 0.21 6.36 0 0.299 0.613 90.5 2505420 122.22169 14.1 October 0.21 6.42 0 0.3 0.614 90.6 2525190 122.27170 14.2 November 0.21 6.47 0 0.3 0.614 90.6 2544950 122.3171 14.3 December 0.22 6.52 0 0.301 0.615 90.6 2564720 122.31172 14.3 January 0.22 6.55 0 0.301 0.615 90.6 2584480 122.34173 14.4 February 0.22 6.61 0 0.301 0.616 90.7 2604250 122.37174 14.5 March 0.23 6.67 0 0.302 0.617 90.7 2624010 122.4175 14.6 April 0.23 6.72 0 0.302 0.618 90.7 2643780 122.43176 14.7 May 0.23 6.79 0 0.303 0.619 90.7 2663540 122.46177 14.8 June 0.23 6.87 0 0.305 0.621 90.8 2683310 122.49178 14.8 July 0.24 6.94 0 0.307 0.623 90.8 2703070 122.55179 14.9 August 0.24 7.02 0 0.309 0.626 90.9 2722840 122.58180 15 September 0.24 7.1 0 0.311 0.628 90.9 2742610 122.61181 15.1 October 0.24 7.16 0 0.312 0.63 90.9 2763160 122.64182 15.2 November 0.25 7.22 0 0.312 0.631 90.9 2783720 122.67183 15.3 December 0.25 7.28 0 0.313 0.631 91 2804270 122.7184 15.3 January 0.25 7.33 0 0.313 0.632 91 2824830 122.73185 15.4 February 0.26 7.38 0 0.314 0.632 91 2845390 122.76186 15.5 March 0.26 7.46 0 0.314 0.634 91.1 2865940 122.79187 15.6 April 0.26 7.52 0 0.315 0.635 91.1 2886500 122.82188 15.7 May 0.26 7.59 0 0.316 0.636 91.1 2907050 122.88189 15.8 June 0.27 7.67 0 0.318 0.638 91.2 2927610 122.91190 15.8 July 0.27 7.75 0 0.32 0.641 91.2 2948170 122.94191 15.9 August 0.27 7.84 0 0.322 0.643 91.3 2968720 123192 16 September 0.27 7.91 0 0.323 0.645 91.3 2989280 123.03193 16.1 October 0.28 7.99 0 0.324 0.646 91.3 3010660 123.06194 16.2 November 0.28 8.04 0 0.325 0.647 91.3 3032040 123.09195 16.3 December 0.28 8.1 0 0.325 0.647 91.4 3053410 123.12196 16.3 January 0.29 8.14 0 0.325 0.648 91.4 3074790 123.15


197 16.4 February 0.29 8.19 0 0.325 0.648 91.4 3096170 123.19198 16.5 March 0.29 8.25 0 0.326 0.649 91.4 3117550 123.19199 16.6 April 0.3 8.32 0 0.326 0.65 91.5 3138930 123.25200 16.7 May 0.3 8.4 0 0.328 0.651 91.5 3160310 123.28201 16.8 June 0.3 8.48 0 0.33 0.654 91.5 3181680 123.31202 16.8 July 0.3 8.57 0 0.333 0.658 91.6 3203060 123.37203 16.9 August 0.31 8.66 0 0.335 0.66 91.6 3224440 123.4204 17 September 0.31 8.74 0 0.336 0.662 91.7 3245820 123.46205 17.1 October 0.31 8.83 0 0.338 0.663 91.7 3268050 123.49206 17.2 November 0.32 8.9 0 0.338 0.664 91.7 3290290 123.52207 17.3 December 0.32 8.96 0 0.339 0.665 91.8 3312520 123.55208 17.3 January 0.32 9.01 0 0.339 0.665 91.8 3334750 123.58209 17.4 February 0.33 9.07 0 0.339 0.666 91.8 3356990 123.62210 17.5 March 0.33 9.13 0 0.339 0.667 91.9 3379220 123.65211 17.6 April 0.34 9.21 0 0.341 0.668 91.9 3401450 123.68212 17.7 May 0.34 9.29 0 0.342 0.669 91.9 3423690 123.74213 17.8 June 0.34 9.37 0 0.343 0.671 92 3445920 123.77214 17.8 July 0.34 9.46 0 0.345 0.673 92 3468150 123.83215 17.9 August 0.35 9.55 0 0.347 0.676 92.1 3490390 123.86216 18 September 0.35 9.64 0 0.348 0.677 92.1 3512620 123.92217 18.1 October 0.35 9.72 0 0.349 0.679 92.1 3535740 123.95218 18.2 November 0.36 9.79 0 0.349 0.679 92.2 3558870 123.98219 18.3 December 0.36 9.85 0 0.35 0.68 92.2 3581990 124.02220 18.3 January 0.37 9.9 0 0.35 0.68 92.2 3605110 124.05221 18.4 February 0.37 9.96 0 0.35 0.681 92.3 3628230 124.08222 18.5 March 0.37 10 0 0.351 0.681 92.3 3651360 124.11223 18.6 April 0.38 10.1 0 0.351 0.682 92.3 3674480 124.15224 18.7 May 0.38 10.2 0 0.353 0.684 92.3 3697600 124.18225 18.8 June 0.38 10.3 0 0.354 0.686 92.4 3720730 124.24226 18.8 July 0.39 10.4 0 0.356 0.688 92.4 3743850 124.27227 18.9 August 0.39 10.5 0 0.357 0.69 92.5 3766970 124.33228 19 September 0.39 10.6 0 0.359 0.692 92.5 3790090 124.36229 19.1 October 0.4 10.6 0 0.36 0.693 92.6 3814140 124.42230 19.2 November 0.4 10.7 0 0.36 0.694 92.6 3838190 124.45231 19.3 December 0.41 10.8 0 0.36 0.694 92.6 3862240 124.49232 19.3 January 0.41 10.8 0 0.36 0.694 92.7 3886280 124.52233 19.4 February 0.41 10.9 0 0.361 0.695 92.7 3910330 124.55234 19.5 March 0.42 10.9 0 0.361 0.696 92.7 3934380 124.59235 19.6 April 0.42 11 0 0.362 0.697 92.7 3958430 124.62236 19.7 May 0.43 11.1 0 0.363 0.698 92.8 3982480 124.65237 19.8 June 0.43 11.2 0 0.365 0.7 92.8 4006520 124.71238 19.8 July 0.43 11.3 0 0.366 0.702 92.9 4030570 124.77239 19.9 August 0.44 11.4 0 0.368 0.704 92.9 4054620 124.8240 20 September 0.44 11.5 0 0.37 0.707 93 4078670 124.86

Layers Modulus: Project T-1

mo yr 1 2 3 4 5 1 2 3 4 5 1 2 3 4 5 1 2 3 4 51 0.08 October 1193000 1029990 907538 690730 461000 1026980 886443 780950 621795 433343 894357 773957 686137 569015 418123 788400 683668 611949 524975 407045 41640 41320 29568 8100 8090 8070 80302 0.17 November 1650020 1351770 1179150 973119 635024 1400610 1162060 1016930 857296 584978 1199570 1009380 892737 763072 555887 1047520 897208 798827 694642 530741 42160 41840 29456 8100 8090 8070 80303 0.25 December 2184150 1573110 1353090 1058090 715760 1862440 1332740 1148740 920676 660753 1590700 1143900 993300 828764 626664 1382900 1002710 877306 759241 603013 42640 42320 29400 8100 8090 8070 80304 0.33 January 2470810 1669580 1437010 1143420 687046 2106940 1418280 1231130 984798 626923 1780720 1218670 1057440 865121 590891 1532170 1078270 932294 777359 563964 43000 42720 29372 8090 8090 8070 80305 0.42 February 1859640 1487700 1307410 1010340 701833 1566430 1249910 1096320 880767 636447 1324340 1067950 943886 781115 596964 1138090 929848 831818 709443 574199 43320 43040 29316 8090 8080 8070 80306 0.5 March 1630170 1377320 1153720 830020 529096 1356820 1142080 958342 723904 477809 1127330 956416 812086 645635 450345 961782 823431 710488 590439 433115 43600 43320 29316 8090 8080 8070 80307 0.58 April 1770250 1431620 1214880 909138 630963 1461720 1188610 1013630 790480 563021 1210440 999309 858771 700154 522566 1028140 860345 751586 636295 496831 43840 43600 29288 8090 8080 8070 80308 0.67 May 1392410 1185720 984478 743447 534684 1143150 974633 819769 641918 473018 950348 813515 697291 567576 435765 806254 699082 610902 515529 411890 44120 43840 29316 8090 8080 8070 80309 0.75 June 1306010 1081040 881036 658210 475944 1072410 881769 730443 566898 419223 885408 736651 616842 502340 383618 752472 629118 540937 456159 361984 44320 44040 29344 8090 8080 8070 803010 0.83 July 1118950 971190 803067 578577 454693 910856 789225 658361 498471 396950 747323 652547 552096 440842 362629 629356 554043 481005 401507 340832 44440 44160 29344 8080 8080 8070 803011 0.92 August 1169790 1025230 858215 639130 483927 950932 834916 704948 544634 423079 781305 688618 589848 479429 384552 658849 585528 509098 429931 362294 44560 44320 29372 8080 8080 8070 803012 1 September 1307470 1159870 1009460 776007 578360 1067710 948355 826457 660382 503591 886066 786668 690514 573465 453863 747884 669786 597262 514396 422167 44720 44480 29400 8080 8080 8070 803013 1.08 October 1715880 1375930 1219230 937944 673445 1413630 1132740 1004290 794488 587799 1164860 946424 834974 687768 532524 983912 803504 717984 612192 494117 44840 44600 29428 8080 8080 8060 803014 1.17 November 2256760 1765620 1521770 1266580 942003 1885410 1468020 1266490 1076720 820844 1559900 1230440 1071650 931168 745968 1311950 1046840 927448 825859 687049 45000 44720 29456 8080 8080 8060 803015 1.25 December 3315450 2331090 1772720 1480780 1041180 2901260 1987200 1498620 1245150 912707 2489890 1694800 1277990 1069980 817560 2118900 1461890 1110950 940833 750122 45080 44840 29484 8080 8080 8060 803016 1.33 January 2923420 2169500 1864880 1549790 1148010 2522900 1844800 1567340 1321500 1001350 2151610 1565400 1337920 1141180 901849 1838870 1352530 1157410 1011920 827883 45200 44920 29512 8080 8080 8060 803017 1.42 February 3317990 2272940 1832560 1476580 956848 2902840 1940360 1557700 1260350 833922 2478100 1642870 1322360 1085900 760929 2117350 1427820 1153470 957135 704089 45320 45080 29540 8080 8070 8060 803018 1.5 March 3147790 2119340 1757110 1343280 945007 2708190 1781570 1469670 1154630 831523 2281190 1493320 1238620 1004200 754751 1915430 1268430 1068620 894975 706039 45440 45200 29568 8080 8070 8060 803019 1.58 April 2138920 1677200 1407480 1011860 731272 1767360 1374680 1153680 862161 635520 1446050 1130340 957548 755668 577317 1197860 956499 824003 675910 538008 45520 45280 29596 8080 8070 8060 803020 1.67 May 1638520 1324440 1056880 734668 538743 1329390 1069450 864252 624545 467195 1072770 868023 711329 546159 424476 879712 727958 608606 494748 397231 45600 45360 29624 8080 8070 8060 803021 1.75 June 1329230 1111870 902067 631051 472801 1068530 892640 725925 530763 405479 856052 723001 598075 462865 364304 708606 603737 508860 417218 337525 45680 45400 29680 8080 8070 8060 803022 1.83 July 1255390 1060380 854130 635716 467165 1010750 846513 693238 532404 396064 815402 687463 572278 458963 351458 677275 575822 489902 410240 322605 45680 45440 29708 8080 8070 8060 803023 1.92 August 1282740 1122700 936582 688099 501803 1037090 897002 755985 575511 428886 839583 728209 619667 495004 382536 696656 609403 526379 439590 351673 45680 45440 29708 8080 8070 8060 803024 2 September 1452630 1271460 1109270 885864 642434 1189470 1031250 902569 736959 546027 976181 841030 746581 630724 481468 819178 708811 636652 551702 437669 45680 45440 29736 8080 8070 8060 803025 2.08 October 1668990 1422430 1227470 947870 662746 1376310 1158430 1001740 789966 567293 1127890 949754 819417 676729 505680 946239 796509 698593 594355 463201 45680 45440 29736 8080 8070 8060 803026 2.17 November 2117350 1739590 1521780 1193860 840538 1768790 1437900 1253340 1003890 727342 1456960 1179450 1033130 857973 651974 1219990 993810 877420 752411 598824 45680 45440 29736 8080 8070 8060 803027 2.25 December 2763430 1925320 1749160 1421640 995575 2374980 1616800 1458570 1200650 865261 1998990 1356690 1218330 1018140 774516 1694910 1150270 1035880 890912 711503 45680 45440 29764 8080 8070 8060 803028 2.33 January 3401950 2228980 1920020 1574310 1073890 3010860 1878820 1611750 1326060 933062 2628820 1597830 1358220 1133090 840777 2277630 1367640 1162330 993112 770523 45680 45440 29764 8080 8070 8060 803029 2.42 February 3294890 2323310 1937460 1435800 925378 2863990 1957340 1620140 1227790 812089 2424330 1629070 1352660 1059290 741137 2029100 1381190 1157190 930779 693000 45680 45440 29764 8080 8070 8060 803030 2.5 March 2918570 2215150 1803970 1263450 863228 2492010 1848950 1487160 1085240 754063 2075720 1518230 1242240 943478 687902 1735380 1277420 1055410 841237 641193 45680 45440 29764 8080 8070 8060 803031 2.58 April 2094430 1667090 1347510 927400 634069 1723590 1349600 1088420 783799 547448 1402930 1098290 888986 684021 492842 1154970 910610 755789 607921 460340 45680 45440 29764 8080 8070 8060 803032 2.67 May 1964130 1541840 1241550 865001 629437 1607660 1253090 1003240 728305 541019 1304080 1013070 824555 631184 484691 1077310 843176 694564 564037 445620 45680 45440 29764 8080 8070 8060 803033 2.75 June 1578570 1343250 1145890 913188 688186 1284360 1093070 937223 759455 582461 1052300 892172 775058 649069 512615 875518 748321 665659 566908 465264 45680 45440 29764 8080 8070 8060 803034 2.83 July 1477700 1260560 1044730 768359 561618 1202850 1014690 844837 640476 474351 979338 823495 694301 549885 417258 814362 687491 588406 483750 379591 45680 45440 29764 8080 8070 8060 803035 2.92 August 1400310 1214850 1026780 771337 594154 1131990 976286 832629 642751 501467 912545 788432 681190 549638 442011 752131 657923 576958 485073 402753 45680 45440 29764 8080 8070 8060 803036 3 September 1596250 1363240 1166920 926554 621515 1298960 1104930 947030 767375 527204 1054540 897496 779424 650252 467102 876579 752002 660590 565031 426245 45680 45440 29764 8080 8070 8060 803037 3.08 October 2026260 1601710 1394000 1129420 794451 1684230 1314550 1149420 943638 676112 1387300 1081440 949936 798053 597667 1156800 910914 806101 689971 542011 45680 45440 29764 8080 8070 8060 803038 3.17 November 2519170 2008580 1780810 1372280 1019400 2120420 1683090 1471640 1163110 882859 1756270 1399250 1221090 1003090 786856 1453290 1184010 1034890 885699 719738 45680 45440 29764 8080 8070 8060 803039 3.25 December 3588640 2369210 2064480 1683290 1213090 3175780 2026230 1741790 1440310 1053560 2751380 1713700 1471710 1243590 947184 2367790 1468750 1265840 1084230 864336 45680 45440 29764 8080 8070 8060 803040 3.33 January 3793800 2703220 2209470 1784820 1190430 3486650 2336590 1884520 1514040 1044690 3077720 2000980 1600630 1304780 938456 2711620 1721250 1374270 1144840 863407 45680 45440 29764 8080 8070 8060 803041 3.42 February 3367790 2512260 2128090 1590240 1080190 2949130 2142800 1792200 1366330 945231 2528960 1802480 1502280 1186730 858262 2169320 1540650 1299510 1052460 793375 45680 45440 29764 8080 8070 8060 803042 3.5 March 2429580 2066210 1704870 1232610 849625 2045710 1712120 1410130 1045710 737155 1689040 1417470 1161940 900792 662570 1409210 1181510 992265 799292 613501 45680 45440 29764 8080 8070 8060 803043 3.58 April 2436320 1966000 1605280 1153710 796769 2024070 1622100 1316770 982459 685829 1661620 1326350 1091760 847412 616036 1363990 1109130 926744 750496 568513 45680 45440 29764 8080 8070 8060 803044 3.67 May 1870890 1572250 1248230 891242 644346 1537490 1271770 1014370 748059 548847 1248140 1021420 830962 645548 484991 1032490 847247 702928 572087 442960 45680 45440 29764 8080 8070 8060 803045 3.75 June 1600970 1404680 1159600 870544 649995 1301730 1129460 939182 727023 550207 1055110 916052 773962 621891 482779 871226 762480 651418 548329 439137 45680 45440 29764 8080 8070 8060 803046 3.83 July 1537700 1340850 1113820 813378 629552 1242050 1080010 897072 676716 531632 1005290 867737 735437 581177 468504 826110 718945 618592 513187 425392 45680 45440 29764 8080 8070 8060 803047 3.92 August 1535360 1343980 1124360 825797 640451 1239950 1078210 909184 689743 541179 1003390 869699 742514 588382 475578 824385 720403 621974 521544 430405 45680 45440 29764 8080 8070 8060 803048 4 September 1568940 1377670 1188940 894227 659127 1279200 1115320 959855 744634 557730 1040390 903825 784697 632314 490731 858474 751745 657438 553066 444529 45680 45440 29764 8080 8070 8060 803049 4.08 October 2162860 1840960 1566300 1174540 843002 1799160 1517230 1282180 984763 721746 1478840 1241700 1051880 845024 639269 1226960 1036000 887457 741106 578494 45680 45440 29764 8080 8070 8060 803050 4.17 November 2965110 2220900 1904960 1492840 1009310 2558670 1868960 1595090 1259700 870765 2156230 1562490 1333070 1073950 778913 1813910 1325290 1129990 935132 712782 45680 45440 29764 8080 8070 8060 803051 4.25 December 3793800 2701730 2189750 1848740 1291700 3630090 2356010 1873750 1571600 1124240 3209410 2028560 1613200 1336980 990586 2797500 1754970 1405800 1166980 895508 45680 45440 29764 8080 8070 8060 803052 4.33 January 3793800 3568470 2664150 2048290 1358280 3673740 3194630 2329800 1780980 1196160 3563400 2823250 2044430 1557300 1090400 3467290 2501910 1828220 1404340 1003140 45680 45440 29764 8080 8070 8060 803053 4.42 February 2616300 2180750 1901190 1391870 971922 2241590 1831710 1570520 1188120 842042 1882660 1528980 1299030 1022960 757105 1586310 1288820 1105460 909337 697223 45680 45440 29764 8080 8070 8060 803054 4.5 March 3059060 2158500 1808380 1358360 920534 2627520 1803010 1501040 1157490 794432 2187380 1488910 1250110 999504 714422 1821930 1260170 1067590 879722 658778 45680 45440 29764 8080 8070 8060 803055 4.58 April 2326200 1954810 1603470 1155060 770265 1948820 1604110 1314010 970423 658987 1602100 1309610 1087790 834661 588021 1325390 1093190 917379 734001 539530 45680 45440 29764 8080 8070 8060 803056 4.67 May 2122920 1723740 1388980 1035140 728791 1762460 1407250 1137880 873841 619020 1453230 1142250 941032 750993 546310 1204270 950938 802173 661091 499499 45680 45440 29764 8080 8070 8060 803057 4.75 June 1572010 1365550 1115020 835404 640734 1275730 1095370 900166 694178 539540 1027500 882599 736509 594946 473754 842944 726759 622959 522157 428650 45680 45440 29764 8080 8070 8060 803058 4.83 July 1682580 1404190 1186110 883286 675909 1377150 1132380 956423 733530 569177 1116720 916811 780562 630111 496217 920691 761344 660653 551757 448263 45680 45440 29764 8080 8070 8060 803059 4.92 August 1547000 1305550 1130560 822778 609940 1259340 1053180 909654 682853 511680 1022540 851103 735688 580403 446104 849792 709257 617207 506935 402260 45680 45440 29764 8080 8070 8060 803060 5 September 1585800 1367080 1104970 761078 538118 1282010 1087720 878317 632943 455559 1023530 861815 707086 539758 401653 832050 706454 588297 477080 367373 45680 45440 29764 8080 8070 8060 803061 5.08 October 1990330 1670780 1454120 1087650 739882 1642690 1366660 1174580 906570 632372 1342250 1112610 955654 770684 559916 1109610 916944 803911 670219 511819 45680 45440 29764 8080 8070 8060 803062 5.17 November 2753690 2196340 1869410 1512870 967634 2341800 1854100 1562180 1271330 833631 1954890 1540800 1309170 1073560 741967 1632780 1305100 1113320 929259 676069 45680 45440 29764 8080 8070 8060 803063 5.25 December 3552330 2493970 2095260 1592900 1057660 3150660 2105130 1752780 1349140 927092 2738500 1766690 1465230 1163170 840216 2366720 1490550 1244770 1023380 776007 45680 45440 29764 8080 8070 8060 803064 5.33 January 3793800 2548470 2167290 1684670 993349 3442060 2186310 1843700 1414560 863356 3002640 1868640 1553940 1200770 772703 2622500 1607070 1316410 1037840 707918 45680 45440 29764 8080 8070 8060 803065 5.42 February 2776390 2179110 1892470 1435060 988158 2385210 1829710 1569020 1216370 858387 2004650 1533890 1315100 1047290 770862 1685920 1292100 1118330 917868 714833 45680 45440 29764 8080 8070 8060 803066 5.5 March 2337740 1948930 1611960 1146270 745832 1950230 1598380 1315180 968784 639169 1602760 1310040 1078310 831863 571542 1325120 1081980 904135 733333 526198 45680 45440 29764 8080 8070 8060 803067 5.58 April 2487440 1983110 1658690 1232390 862222 2079770 1643270 1367390 1042230 736383 1709180 1355100 1132820 897906 657311 1416970 1130980 959340 789934 602335 45680 45440 29764 8080 8070 8060 803068 5.67 May 1884810 1591260 1312640 992188 728442 1541580 1291690 1071180 831102 616971 1255240 1048990 879455 708654 542675 1030790 871230 747727 621605 492782 45680 45440 29764 8080 8070 8060 803069 5.75 June 1729410 1415600 1154770 870024 646954 1411530 1141380 936263 725637 545128 1139760 923391 765669 619451 475714 938983 765860 649426 543096 429146 45680 45440 29764 8080 8070 8060 803070 5.83 July 1449700 1255010 1039010 761338 613135 1165570 1002040 832282 634069 513104 931646 801638 675954 537774 447416 759673 661452 569914 474277 403666 45680 45440 29764 8080 8070 8060 803071 5.92 August 1496140 1307820 1094890 824757 639900 1204930 1050210 882149 683267 538549 967926 844284 717401 579445 469391 792665 696749 600619 504927 425907 45680 45440 29764 8080 8070 8060 803072 6 September 1655820 1464130 1271710 980783 743302 1347360 1187360 1027770 817695 625919 1100480 965523 839139 691174 546826 905952 800866 706738 603181 492798 45680 45440 29764 8080 8070 8060 803073 6.08 October 2165460 1723920 1522630 1168460 847520 1800580 1418720 1247870 976860 722297 1478560 1166370 1020650 828513 636280 1230910 969770 858342 720737 575013 45680 45440 29764 8080 8070 8060 803074 6.17 November 2829080 2203260 1890590 1565800 1161570 2414190 1851770 1580880 1329450 1000850 2021070 1553320 1331310 1139310 895730 1691140 1308630 1137490 996143 811204 45680 45440 29764 8080 8070 8060 803075 6.25 December 3793800 2888770 2187850 1818750 1271330 3660550 2517390 1871100 1535960 1107030 3239990 2181780 1601640 1315500 980312 2826780 1896970 1386500 1145570 887418 45680 45440 29764 8080 8070 8060 803076 6.33 January 3565540 2659450 2280730 1887090 1390000 3164120 2303560 1941190 1620010 1208900 2765050 1978210 1666560 1398830 1081220 2404840 1716620 1438240 1233640 983180 45680 45440 29764 8080 8070 8060 803077 6.42 February 3793800 2759880 2219230 1779750 1149090 3582590 2401670 1909310 1526670 992872 3145090 2060660 1628790 1312940 895176 2747670 1803380 1418660 1148670 817460 45680 45440 29764 8080 8070 8060 803078 6.5 March 3754370 2549370 2107650 1602970 1126490 3319710 2176930 1779630 1380780 983025 2865520 1840940 1502920 1196340 881923 2448600 1564400 1290280 1057620 815255 45680 45440 29764 8080 8070 8060 803079 6.58 April 2551870 1994000 1668110 1196850 872125 2139760 1645410 1369370 1013280 746699 1762220 1350050 1128810 877934 665759 1454800 1131550 959573 774163 609338 45680 45440 29764 8080 8070 8060 803080 6.67 May 1932900 1557350 1241490 870316 651052 1576790 1256790 1009530 729866 552659 1266980 1010310 820018 626709 489435 1025180 834329 689893 557103 447284 45680 45440 29764 8080 8070 8060 803081 6.75 June 1552850 1297720 1055120 749097 574429 1247730 1037230 842093 620294 481727 989963 829731 683428 529941 421147 806751 681285 571204 467881 380319 45680 45440 29764 8080 8070 8060 803082 6.83 July 1457000 1230550 994598 749897 564712 1171290 977413 800241 618953 468902 935687 783964 650868 523363 405383 765503 646031 547612 458568 362905 45680 45440 29764 8080 8070 8060 8030

Subseason Layer Modulus: Project T-1Pavement

ageMonth

Modulus (psi)AC1 (1) h=0.5 AC1 (2) h=0.5 AC1 (3) h=1.0 AC1 (4) h=1.0 GB2 (5)

h=2.0GB2 (6)

h=4.0NSG4 (11)

h=264.0NSG3 (7)

h=9.0NSG4 (8)

h=24.0NSG4 (9)

h=24.0NSG4 (10)

h=24.0


83 6.92 August 1480520 1295400 1082510 803658 599094 1196080 1031190 867926 663831 502256 959985 828037 702173 561240 437426 785397 682554 586993 489476 393094 45680 45440 29764 8080 8070 8060 803084 7 September 1669310 1459610 1273280 1019820 749261 1370280 1183020 1032560 842151 628145 1119310 957191 845835 711869 544048 929412 796640 711672 613686 485756 45680 45440 29764 8080 8070 8060 803085 7.08 October 1910870 1625920 1401910 1084460 767803 1584930 1326600 1142790 898578 648829 1297500 1082220 927478 761620 568776 1080680 898101 781518 660294 512439 45680 45440 29764 8080 8070 8060 803086 7.17 November 2416900 1982670 1732120 1357100 959901 2041740 1649690 1431710 1140050 824044 1691470 1353450 1176920 968718 730489 1415450 1134130 991845 841901 663124 45680 45440 29764 8080 8070 8060 803087 7.25 December 3133400 2185940 1984330 1609860 1128100 2736840 1852200 1665920 1363420 976372 2334890 1560840 1393690 1153720 867838 1997150 1321430 1180440 1003880 790780 45680 45440 29764 8080 8070 8060 803088 7.33 January 3793800 2520800 2170100 1776440 1210870 3434410 2149550 1837420 1503420 1049540 3051700 1843050 1555020 1285320 941093 2684190 1582820 1329890 1123090 857009 45680 45440 29764 8080 8070 8060 803089 7.42 February 3681910 2616060 2180640 1612470 1041470 3257650 2230430 1838890 1383250 909211 2803560 1871290 1541240 1192690 823684 2376290 1591580 1317620 1043740 764360 45680 45440 29764 8080 8070 8060 803090 7.5 March 3263200 2484280 2021320 1412920 969462 2829610 2095540 1677180 1214570 841515 2387780 1731070 1403730 1053080 761079 2012940 1457940 1189200 934139 703197 45680 45440 29764 8080 8070 8060 803091 7.58 April 2339690 1859920 1501680 1036220 718256 1942720 1512430 1213940 871688 613204 1587560 1229490 986939 754555 544201 1304240 1012880 832273 664071 501265 45680 45440 29764 8080 8070 8060 803092 7.67 May 2185680 1713300 1378790 964760 710789 1802340 1396800 1113730 807851 604375 1465360 1126420 910462 693855 533953 1206600 930875 760076 613675 484243 45680 45440 29764 8080 8070 8060 803093 7.75 June 1748520 1486940 1268800 1014020 771161 1427580 1211150 1036400 839606 647094 1167910 984467 852057 711746 562701 965615 819172 725512 615471 504415 45680 45440 29764 8080 8070 8060 803094 7.83 July 1631140 1391080 1154160 854607 634159 1330910 1119670 931059 707780 529788 1080770 904117 759894 601618 459279 892457 748342 637870 523374 411730 45680 45440 29764 8080 8070 8060 803095 7.92 August 1540860 1336830 1131280 855281 666559 1247440 1073770 915072 708316 557063 1001960 862510 743552 599925 484469 819421 713558 623909 523747 435492 45680 45440 29764 8080 8070 8060 803096 8 September 1752270 1495780 1280740 1019660 693497 1430800 1213730 1038500 841390 582895 1160040 982356 850320 707848 510050 958939 817310 714935 609531 459645 45680 45440 29764 8080 8070 8060 803097 8.08 October 2220260 1753470 1525470 1236540 875251 1858670 1444210 1259920 1032060 740581 1536260 1187350 1038720 868908 649067 1279730 995717 876407 746011 583227 45680 45440 29764 8080 8070 8060 803098 8.17 November 2751770 2194950 1945270 1497820 1114380 2339450 1852040 1615670 1271820 962927 1951890 1545310 1342500 1095750 854459 1620050 1307460 1135260 964385 777431 45680 45440 29764 8080 8070 8060 803099 8.25 December 3793800 2582220 2250380 1833720 1321090 3476660 2228430 1912320 1576440 1147720 3051330 1897620 1623140 1364260 1030460 2655260 1632590 1398140 1188770 937870 45680 45440 29764 8080 8070 8060 8030100 8.33 January 3793800 2936020 2402590 1940060 1293510 3673740 2563950 2065550 1654330 1135330 3393140 2215040 1764410 1429860 1018410 3024880 1917240 1518990 1255180 934772 45680 45440 29764 8080 8070 8060 8030101 8.42 February 3631330 2724140 2308690 1723940 1171920 3218580 2344910 1958230 1486860 1024260 2791860 1986620 1648880 1293510 927540 2417250 1705360 1429130 1146670 854542 45680 45440 29764 8080 8070 8060 8030102 8.5 March 2629120 2236510 1844530 1333320 923394 2232570 1865140 1531820 1131550 797674 1854340 1549480 1262960 972606 712493 1550830 1291030 1076150 859637 655409 45680 45440 29764 8080 8070 8060 8030103 8.58 April 2630710 2123340 1732860 1245840 865567 2203590 1761750 1425850 1060490 741388 1819050 1443850 1182050 912108 661263 1495500 1205950 1000280 804148 605820 45680 45440 29764 8080 8070 8060 8030104 8.67 May 2016290 1693730 1344760 963702 703744 1665000 1373660 1093070 806286 595273 1353480 1101840 892551 691791 521076 1117010 909873 750752 608822 471325 45680 45440 29764 8080 8070 8060 8030105 8.75 June 1721410 1510140 1247360 939980 708202 1403650 1215900 1009790 782439 595593 1136880 983947 829061 665373 517910 934850 814782 693561 582518 466657 45680 45440 29764 8080 8070 8060 8030106 8.83 July 1650220 1438940 1196290 878010 685486 1336000 1160060 962743 727747 575074 1080000 929518 786107 621016 502117 883431 765919 657118 544306 451601 45680 45440 29764 8080 8070 8060 8030107 8.92 August 1644790 1439780 1205430 889493 695518 1331300 1156090 974097 740297 584048 1076030 930117 792498 627726 508767 880122 766373 659852 552461 456277 45680 45440 29764 8080 8070 8060 8030108 9 September 1677960 1473340 1272070 959926 713676 1371520 1194190 1026820 797178 600364 1114670 965685 836700 673447 523896 916186 799353 697130 585255 470516 45680 45440 29764 8080 8070 8060 8030109 9.08 October 2310210 1966160 1672380 1254730 904536 1933010 1627170 1372430 1051860 771723 1594260 1333410 1125380 900455 679854 1322990 1110630 946578 786565 611543 45680 45440 29764 8080 8070 8060 8030110 9.17 November 3155100 2368310 2031350 1591380 1078000 2746120 2005110 1708700 1345900 928531 2331780 1683130 1431280 1147580 827965 1972040 1429830 1212820 997420 754786 45680 45440 29764 8080 8070 8060 8030111 9.25 December 3793800 2873790 2331510 1968300 1375130 3673740 2525180 2006840 1680480 1198080 3448000 2188750 1735560 1433090 1055150 3033770 1902880 1516400 1251640 952415 45680 45440 29764 8080 8070 8060 8030112 9.33 January 3793800 3769620 2829970 2177700 1443750 3673740 3405090 2492990 1903590 1273480 3563400 3035930 2201910 1671430 1161860 3467290 2711380 1979540 1511920 1068900 45680 45440 29764 8080 8070 8060 8030113 9.42 February 2775570 2315130 2018310 1477340 1034050 2394840 1955240 1674150 1263070 894206 2022880 1637920 1387230 1087210 801405 1710300 1382110 1180010 964938 735296 45680 45440 29764 8080 8070 8060 8030114 9.5 March 3234960 2288350 1917040 1439870 978828 2801160 1921480 1597030 1228560 842790 2348610 1591740 1331970 1060410 755054 1965790 1348370 1136710 931482 693370 45680 45440 29764 8080 8070 8060 8030115 9.58 April 2462520 2069660 1697370 1223570 820934 2074890 1705360 1394330 1027800 699680 1712240 1394660 1154350 882172 620868 1418020 1163210 971315 773123 566360 45680 45440 29764 8080 8070 8060 8030116 9.67 May 2244760 1822470 1468520 1096170 776835 1872600 1492240 1204500 924370 657164 1548320 1211660 994968 792108 576545 1283150 1006590 845562 694434 523826 45680 45440 29764 8080 8070 8060 8030117 9.75 June 1659910 1442040 1178540 886430 684827 1349890 1157840 951063 734709 573920 1086580 931323 775931 626789 500455 888584 763824 653339 547088 449542 45680 45440 29764 8080 8070 8060 8030118 9.83 July 1774620 1481040 1251710 935130 720200 1456340 1195760 1009340 774971 603895 1181130 966782 821749 662984 523221 971466 800001 692652 577628 469493 45680 45440 29764 8080 8070 8060 8030119 9.92 August 1629700 1375650 1192090 871205 651345 1329230 1110470 958906 721241 543785 1078710 895744 773436 610311 470814 893999 743637 646042 530196 421434 45680 45440 29764 8080 8070 8060 8030120 10 September 1668730 1438740 1164020 806334 576761 1351800 1145790 924929 668582 485382 1078600 906204 742523 567377 424521 874074 739977 615022 498629 385097 45680 45440 29764 8080 8070 8060 8030121 10.08 October 2092380 1756310 1528580 1144700 783528 1733500 1440150 1236440 953615 667272 1418970 1172650 1005020 808777 587776 1172240 964275 843063 700820 534352 45680 45440 29764 8080 8070 8060 8030122 10.17 November 2888820 2306400 1963180 1588660 1018550 2471730 1955900 1646060 1337520 876195 2073680 1630290 1381810 1129620 777716 1737280 1382450 1174850 976426 706333 45680 45440 29764 8080 8070 8060 8030123 10.25 December 3708160 2615350 2198120 1671010 1111140 3312420 2219330 1846380 1418500 973219 2899350 1870140 1547430 1224080 880565 2520880 1581360 1315560 1076550 811620 45680 45440 29764 8080 8070 8060 8030124 10.33 January 3793800 2669600 2271370 1765580 1043210 3609140 2302520 1940610 1486280 905570 3171690 1976670 1640560 1262980 808617 2788010 1705030 1391400 1091050 738781 45680 45440 29764 8080 8070 8060 8030125 10.42 February 2903970 2281560 1981550 1502650 1036840 2509180 1923830 1648150 1275510 899546 2119120 1617370 1383710 1098300 805977 1787880 1363680 1176510 961409 745475 45680 45440 29764 8080 8070 8060 8030126 10.5 March 2445070 2038790 1686230 1200110 785551 2049080 1677570 1378510 1014180 671048 1689140 1376960 1130270 869470 597266 1397820 1136380 945986 764489 547244 45680 45440 29764 8080 8070 8060 8030127 10.58 April 2598770 2072690 1733570 1288660 904717 2183450 1723330 1432280 1090230 771075 1800660 1423580 1187100 938310 685928 1495060 1187810 1004030 823746 626217 45680 45440 29764 8080 8070 8060 8030128 10.67 May 1968250 1661670 1371100 1038230 766202 1614530 1351300 1119650 868810 646977 1316050 1097210 918139 738959 566465 1079510 909400 778557 645965 511852 45680 45440 29764 8080 8070 8060 8030129 10.75 June 1804430 1477160 1205850 911170 681970 1476190 1192300 977661 758664 572543 1192380 963673 798004 645552 497021 980698 797135 674666 563701 445852 45680 45440 29764 8080 8070 8060 8030130 10.83 July 1511480 1308950 1084930 798592 646749 1216680 1045540 868648 663507 539218 971610 835062 703812 560571 467587 790049 686821 591237 492084 419382 45680 45440 29764 8080 8070 8060 8030131 10.92 August 1558620 1362780 1141910 863074 673507 1256940 1095020 919795 713698 564829 1009040 879112 746456 603202 489785 824259 723344 622819 523441 441948 45680 45440 29764 8080 8070 8060 8030132 11 September 1723570 1524150 1324260 1023100 778757 1405210 1237560 1070760 852183 654073 1147950 1005740 873074 718615 569097 943374 832309 733319 625061 510567 45680 45440 29764 8080 8070 8060 8030133 11.08 October 2252230 1793120 1583810 1216300 885093 1879370 1478910 1299930 1016910 752877 1546550 1216560 1062970 861314 661146 1287980 1010270 892339 747477 595366 45680 45440 29764 8080 8070 8060 8030134 11.17 November 2937240 2289820 1965060 1627520 1208290 2518870 1931480 1647670 1384300 1041130 2117470 1624220 1389670 1187060 931007 1776590 1369610 1187480 1037380 841940 45680 45440 29764 8080 8070 8060 8030135 11.25 December 3793800 2996640 2272230 1889070 1321020 3673740 2624110 1950190 1599390 1150990 3382110 2284220 1673840 1371900 1019010 2967410 1992880 1451210 1195110 921664 45680 45440 29764 8080 8070 8060 8030136 11.33 January 3685850 2758450 2366900 1958690 1443000 3289000 2399900 2021980 1686150 1256410 2889680 2068820 1740920 1458680 1124220 2525030 1800290 1504970 1287630 1022120 45680 45440 29764 8080 8070 8060 8030137 11.42 February 3793800 2860100 2301650 1846060 1192940 3673740 2500090 1987210 1587380 1030730 3279420 2153610 1699800 1367150 928576 2880070 1890490 1482960 1196600 846900 45680 45440 29764 8080 8070 8060 8030138 11.5 March 3793800 2641360 2184640 1661660 1168860 3444030 2264710 1850470 1433980 1019850 2989360 1921510 1566110 1243580 914161 2566690 1636250 1345780 1099420 844068 45680 45440 29764 8080 8070 8060 8030139 11.58 April 2642280 2065600 1728070 1240690 906555 2224470 1709160 1421170 1050600 774954 1837490 1404300 1171950 909475 689142 1519070 1176900 995354 800608 628915 45680 45440 29764 8080 8070 8060 8030140 11.67 May 2001100 1612400 1285980 904119 680041 1636490 1303020 1046090 757164 575499 1316150 1047170 848696 648465 507420 1063910 863217 712314 574596 461606 45680 45440 29764 8080 8070 8060 8030141 11.75 June 1606800 1343230 1093260 779561 601596 1292800 1074170 872315 644290 502793 1025290 858318 706664 548632 437390 833880 703008 588909 482513 392939 45680 45440 29764 8080 8070 8060 8030142 11.83 July 1506850 1273190 1030440 779878 591285 1212610 1011610 828676 642529 489404 968088 810339 672679 541595 421077 790346 666056 564283 472740 375003 45680 45440 29764 8080 8070 8060 8030143 11.92 August 1530280 1339300 1120140 834290 625804 1237640 1066690 897955 688096 523034 992854 855616 725268 580136 453479 810686 703621 604645 504213 405579 45680 45440 29764 8080 8070 8060 8030144 12 September 1724310 1507870 1315780 1055140 778267 1417800 1223390 1067510 870895 651179 1158470 989395 873621 734888 562203 960826 821986 733503 631915 500155 45680 45440 29764 8080 8070 8060 8030145 12.08 October 1972690 1678610 1447580 1120910 796715 1639980 1371660 1181030 928568 671969 1343980 1119120 957958 785922 587261 1118990 927539 805807 679839 527305 45680 45440 29764 8080 8070 8060 8030146 12.17 November 2493070 2045710 1787270 1400670 992598 2113120 1706310 1479980 1177550 851336 1754910 1401670 1217280 1000300 753352 1470270 1174480 1025170 868311 682422 45680 45440 29764 8080 8070 8060 8030147 12.25 December 3225730 2254110 2046370 1660330 1164530 2829390 1915460 1722200 1408340 1007800 2423320 1617440 1442870 1192400 895049 2079140 1370520 1222410 1037180 814586 45680 45440 29764 8080 8070 8060 8030148 12.33 January 3793800 2597310 2236670 1831140 1248930 3540700 2222340 1899090 1552740 1082810 3160200 1910790 1610430 1328970 970575 2791100 1644050 1378580 1161520 883161 45680 45440 29764 8080 8070 8060 8030149 12.42 February 3778790 2693780 2246430 1661380 1074570 3358680 2304720 1899600 1427440 937629 2903710 1939100 1595160 1231720 848499 2470820 1652270 1364920 1077800 786384 45680 45440 29764 8080 8070 8060 8030150 12.5 March 3353310 2557350 2081450 1455310 1000360 2920020 2164160 1731160 1252210 867598 2473720 1792080 1450980 1085900 783481 2091650 1511280 1229590 962761 722671 45680 45440 29764 8080 8070 8060 8030151 12.58 April 2407750 1914440 1545880 1068170 743707 2005080 1559760 1250980 898192 633559 1641710 1268840 1016800 776434 560497 1349470 1044590 856325 681981 514555 45680 45440 29764 8080 8070 8060 8030152 12.67 May 2248480 1762770 1418920 994606 735733 1858940 1439390 1146970 832279 624257 1513670 1161090 937121 713641 549790 1246570 958568 781043 629766 496955 45680 45440 29764 8080 8070 8060 8030153 12.75 June 1798210 1529370 1305430 1044490 796752 1470540 1246950 1066770 864472 667514 1203630 1013320 876347 731739 578927 994324 842001 744940 631387 517405 45680 45440 29764 8080 8070 8060 8030154 12.83 July 1676820 1430300 1187400 881335 657218 1370020 1152080 957971 729162 547805 1112660 929762 780979 618492 473258 917766 768280 654227 536632 422659 45680 45440 29764 8080 8070 8060 8030155 12.92 August 1583420 1374060 1163480 881625 689746 1283290 1104310 941150 729395 575262 1030560 886418 763856 616515 498687 841592 732038 639622 536822 446693 45680 45440 29764 8080 8070 8060 8030156 13 September 1799790 1536510 1316020 1048900 716743 1471910 1248000 1067570 865203 601265 1193860 1009850 873483 726865 524530 986099 839064 733176 624599 471146 45680 45440 29764 8080 8070 8060 8030157 13.08 October 2279200 1800300 1566350 1270230 901192 1912770 1485120 1295070 1060510 761729 1583590 1221640 1067710 892288 666312 1319830 1023910 899977 764973 597361 45680 45440 29764 8080 8070 8060 8030158 13.17 November 2822050 2252370 1996350 1537390 1144800 2406910 1905110 1661350 1306790 989088 2013500 1592240 1381930 1126250 877031 1673880 1348100 1168680 990881 797107 45680 45440 29764 8080 8070 8060 8030159 13.25 December 3793800 2647840 2308290 1881190 1355760 3566300 2291780 1966410 1620190 1178550 3142340 1956390 1672180 1403850 1058270 2744160 1686040 1441920 1223830 962932 45680 45440 29764 8080 8070 8060 8030160 13.33 January 3793800 3007730 2463200 1989490 1327030 3673740 2635120 2123330 1699810 1165360 3488290 2283240 1817700 1471220 1045420 3121040 1980880 1567060 1292410 959348 45680 45440 29764 8080 8070 8060 8030161 13.42 February 3711190 2790760 2366250 1767310 1202260 3301640 2409500 2012070 1526640 1050860 2874440 2046610 1697380 1329450 951308 2496610 1760080 1472870 1179010 875926 45680 45440 29764 8080 8070 8060 8030162 13.5 March 2692830 2291550 1890200 1366790 948374 2293250 1915510 1572360 1160620 818536 1909120 1593840 1297370 997435 730031 1598810 1328690 1105370 880934 670403 45680 45440 29764 8080 8070 8060 8030163 13.58 April 2693520 2174960 1775190 1276890 889203 2262630 1808410 1462750 1087270 760813 1871880 1483950 1213250 934776 677367 1540650 1239740 1026270 823330 619343 45680 45440 29764 8080 8070 8060 8030164 13.67 May 2064690 1734520 1377520 988703 724641 1708210 1408550 1120320 826755 611881 1389950 1130020 914367 708376 534216 1146960 932332 768070 622256 481832 45680 45440 29764 8080 8070 8060 8030165 13.75 June 1762270 1546140 1277580 964216 728874 1438880 1245980 1034590 802141 611982 1165770 1008110 848835 681143 530823 957844 833818 709017 595157 476945 45680 45440 29764 8080 8070 8060 8030166 13.83 July 1688880 1472850 1225030 900882 705589 1368880 1188270 986083 746134 590942 1106720 951777 804507 635647 514603 904398 783221 671407 555947 461499 45680 45440 29764 8080 8070 8060 8030167 13.92 August 1682780 1473230 1233950 912236 715477 1363600 1183810 997376 758665 599834 1102260 952085 810806 642296 521194 900694 783453 674020 564117 466124 45680 45440 29764 8080 8070 8060 8030168 14 September 1716150 1507050 1301550 983518 733596 1404430 1222480 1051000 816375 616177 1141690 988344 855872 688762 536399 937631 817160 712065 597460 480470 45680 45440 29764 8080 8070 8060 8030169 14.08 October 2361520 2010140 1709930 1283450 926908 1980330 1666400 1404910 1076290 790176 1635790 1366760 1152350 921003 695088 1358220 1138310 968698 803722 624152 45680 45440 29764 8080 8070 8060 8030


170 14.17 November 3220330 2420090 2076120 1626670 1103000 2811340 2053600 1749530 1377240 949871 2393820 1726800 1467180 1174810 846373 2028860 1468320 1243650 1020860 770798 45680 45440 29764 8080 8070 8060 8030171 14.25 December 3793800 2933990 2381840 2011120 1405470 3673740 2585060 2054700 1720020 1225300 3529620 2246210 1780160 1468540 1079330 3115870 1956670 1557320 1283350 974056 45680 45440 29764 8080 8070 8060 8030172 14.33 January 3793800 3793800 2888650 2224260 1475060 3673740 3478490 2551360 1948220 1302170 3563400 3110890 2258900 1713510 1188730 3467290 2786020 2034900 1552080 1093960 45680 45440 29764 8080 8070 8060 8030173 14.42 February 2832560 2363780 2061010 1508900 1057320 2450350 2000560 1712470 1291130 914014 2074410 1678490 1420390 1111650 818473 1756590 1417440 1208510 986416 750177 45680 45440 29764 8080 8070 8060 8030174 14.5 March 3297660 2335830 1957100 1470280 1000900 2863870 1965370 1632920 1255440 861351 2407740 1630440 1363070 1083800 770871 2019400 1382110 1163410 951667 707025 45680 45440 29764 8080 8070 8060 8030175 14.58 April 2512610 2112250 1732470 1249500 840440 2121820 1743440 1424800 1049830 715554 1753870 1427170 1180020 900699 633858 1453630 1190430 992473 788619 577116 45680 45440 29764 8080 8070 8060 8030176 14.67 May 2290150 1859610 1498680 1119560 795533 1914170 1524660 1230140 944008 672204 1584770 1238580 1016070 808334 588632 1313890 1028560 862816 707795 533680 45680 45440 29764 8080 8070 8060 8030177 14.75 June 1693370 1471300 1203020 906320 702242 1378530 1182110 970979 750733 587671 1109780 950580 791620 639568 511277 906832 778733 665630 557242 458120 45680 45440 29764 8080 8070 8060 8030178 14.83 July 1809860 1510650 1277140 955453 737779 1487080 1220540 1030160 791443 617849 1206530 986653 838228 676243 534222 991839 815635 705663 588216 478253 45680 45440 29764 8080 8070 8060 8030179 14.92 August 1661730 1402960 1216170 890395 667996 1356670 1133110 978472 736660 556853 1101120 913679 788684 622501 481000 911927 757679 657879 539814 429437 45680 45440 29764 8080 8070 8060 8030180 15 September 1701080 1466830 1187340 824466 592531 1379400 1168880 943610 683048 497682 1100730 924161 756963 578747 434061 891254 753767 626087 507620 392575 45680 45440 29764 8080 8070 8060 8030181 15.08 October 2132150 1789870 1557940 1167410 801169 1769330 1469360 1261160 972589 681541 1449680 1196880 1025060 824360 599308 1197700 983683 859202 713518 543791 45680 45440 29764 8080 8070 8060 8030182 15.17 November 2941010 2349450 2000100 1618730 1039050 2522460 1996150 1679480 1364100 893537 2120640 1666130 1411130 1152440 792463 1779160 1413850 1200040 995890 718971 45680 45440 29764 8080 8070 8060 8030183 15.25 December 3767510 2662900 2238760 1702190 1132770 3374670 2264560 1883770 1446490 992078 2961940 1911590 1580680 1248970 897252 2581550 1618220 1344580 1098550 826518 45680 45440 29764 8080 8070 8060 8030184 15.33 January 3793800 2717380 2312750 1798050 1063570 3673330 2348790 1979530 1515390 922993 3237440 2020150 1675760 1288540 823614 2853110 1744900 1422270 1113210 751819 45680 45440 29764 8080 8070 8060 8030185 15.42 February 2954410 2322600 2017430 1530120 1056860 2558680 1961920 1680380 1299820 916656 2165340 1651550 1411990 1119520 820740 1829560 1393370 1200810 979752 758499 45680 45440 29764 8080 8070 8060 8030186 15.5 March 2488240 2075220 1716520 1222300 802176 2089260 1710020 1404660 1033100 684530 1724690 1404740 1152020 885346 608263 1428140 1159300 963743 777806 556338 45680 45440 29764 8080 8070 8060 8030187 15.58 April 2643750 2109240 1764310 1311960 922523 2225770 1756340 1459210 1110330 785767 1838460 1452160 1209920 955435 698180 1527750 1211860 1023080 838253 636553 45680 45440 29764 8080 8070 8060 8030188 15.67 May 2002600 1690820 1395430 1057560 782236 1644900 1376260 1140070 884819 659849 1341690 1117670 934653 751984 576782 1100340 925825 791891 656563 520211 45680 45440 29764 8080 8070 8060 8030189 15.75 June 1835610 1502900 1227340 928636 697012 1503370 1213840 995285 772839 584436 1214790 980951 811956 656890 506364 998711 810735 685699 572757 453253 45680 45440 29764 8080 8070 8060 8030190 15.83 July 1537470 1331740 1104440 814587 661317 1238430 1064140 884285 676281 550646 988854 849552 715952 570581 476505 803341 697970 600651 499990 426400 45680 45440 29764 8080 8070 8060 8030191 15.92 August 1585060 1386120 1161970 879580 688132 1279200 1114270 936055 726948 576375 1026870 894279 759171 613668 498838 838147 735082 632661 531692 449138 45680 45440 29764 8080 8070 8060 8030192 16 September 1752350 1549730 1346740 1041340 794186 1430040 1259190 1089360 867205 666445 1168570 1023280 887944 730708 578985 959849 846208 745114 634815 518537 45680 45440 29764 8080 8070 8060 8030193 16.08 October 2288990 1822660 1610030 1236940 901466 1913070 1504870 1322470 1034370 766330 1575960 1238460 1081510 875777 672197 1312970 1028160 907421 759403 604503 45680 45440 29764 8080 8070 8060 8030194 16.17 November 2982820 2326720 1996970 1654110 1228590 2563360 1965760 1676560 1408150 1058790 2158850 1655010 1415170 1208030 946618 1813670 1396390 1209560 1055690 855677 45680 45440 29764 8080 8070 8060 8030195 16.25 December 3793800 3042340 2308430 1919420 1342680 3673740 2669660 1984410 1627020 1170320 3441660 2328300 1705360 1396700 1036190 3026930 2034500 1479730 1217110 937012 45680 45440 29764 8080 8070 8060 8030196 16.33 January 3736380 2800850 2404050 1989760 1466200 3341880 2441470 2057100 1715070 1277380 2942910 2108240 1773520 1485090 1143360 2576810 1837010 1534500 1311680 1039620 45680 45440 29764 8080 8070 8060 8030197 16.42 February 3793800 2903220 2337440 1875060 1212340 3673740 2542740 2021290 1614140 1047620 3336810 2194230 1731140 1391260 943612 2937100 1928850 1511590 1218130 860274 45680 45440 29764 8080 8070 8060 8030198 16.5 March 3793800 2681320 2218330 1687560 1187720 3497290 2303150 1881720 1457640 1036370 3042880 1957110 1594240 1264790 928761 2618210 1668290 1370740 1118350 857230 45680 45440 29764 8080 8070 8060 8030199 16.58 April 2681800 2097190 1754660 1260280 922078 2261820 1737530 1444340 1067430 787802 1871000 1428690 1191460 923838 699869 1547980 1197520 1011710 812770 637976 45680 45440 29764 8080 8070 8060 8030200 16.67 May 2031390 1637000 1305960 919446 693318 1663240 1323860 1062660 769653 586041 1338430 1063980 861849 658517 515790 1081670 876545 722712 582754 468327 45680 45440 29764 8080 8070 8060 8030201 16.75 June 1631030 1363760 1110560 793516 614170 1313240 1091010 886161 655382 512618 1041500 871496 717429 557354 445027 846473 713138 597202 489404 398920 45680 45440 29764 8080 8070 8060 8030202 16.83 July 1529400 1292570 1046810 793685 603657 1231490 1027310 841791 653483 499024 983055 822578 682849 550148 428502 801953 675454 572139 479450 380774 45680 45440 29764 8080 8070 8060 8030203 16.92 August 1552910 1359320 1137380 848439 638272 1256720 1083050 911848 699405 532807 1008110 868462 736069 589027 461091 822552 713542 612989 511212 411547 45680 45440 29764 8080 8070 8060 8030204 17 September 1749390 1529940 1335280 1071430 791765 1439650 1242030 1083690 884272 661985 1176660 1004420 886621 745705 570795 975571 833934 743823 640564 507027 45680 45440 29764 8080 8070 8060 8030205 17.08 October 2000940 1702780 1468600 1137790 810228 1665330 1392510 1198790 942574 682869 1365590 1136360 972257 797379 596041 1136980 941439 817317 689141 534424 45680 45440 29764 8080 8070 8060 8030206 17.17 November 2527810 2074640 1812670 1420840 1007860 2145910 1732480 1502380 1195060 864173 1784300 1424170 1236190 1015170 764194 1495900 1193490 1040930 880862 691649 45680 45440 29764 8080 8070 8060 8030207 17.25 December 3267580 2285470 2074990 1683730 1181550 2871610 1944760 1748350 1429330 1022600 2463970 1643870 1465920 1210630 907961 2117120 1393640 1242250 1053010 825973 45680 45440 29764 8080 8070 8060 8030208 17.33 January 3793800 2632520 2267470 1856580 1266770 3588780 2256060 1927810 1575840 1098520 3209620 1942390 1636430 1349570 984604 2840150 1672840 1401620 1179810 895702 45680 45440 29764 8080 8070 8060 8030209 17.42 February 3793800 2729690 2277010 1684300 1090220 3405080 2339270 1928020 1448270 951162 2950000 1970880 1620610 1250280 860401 2514830 1680940 1387420 1094120 797024 45680 45440 29764 8080 8070 8060 8030210 17.5 March 3394720 2591350 2109610 1475320 1015060 2961870 2196310 1756620 1270100 880100 2513820 1820890 1473440 1101620 794296 2128670 1536690 1248960 976583 732140 45680 45440 29764 8080 8070 8060 8030211 17.58 April 2439640 1940140 1566820 1083420 755980 2034520 1582250 1268680 910945 643440 1667490 1287710 1031190 787047 568465 1371200 1059940 868028 690740 521097 45680 45440 29764 8080 8070 8060 8030212 17.67 May 2278120 1786260 1438060 1008950 747822 1885840 1459770 1162950 844108 633956 1536820 1177820 950057 723300 557571 1265910 972065 791312 637684 503245 45680 45440 29764 8080 8070 8060 8030213 17.75 June 1821900 1549670 1323020 1059190 809181 1491180 1264220 1081460 876557 677502 1220940 1027350 888204 741537 586923 1008370 853212 754507 639254 523853 45680 45440 29764 8080 8070 8060 8030214 17.83 July 1698740 1449180 1203470 894338 668537 1388930 1167800 971080 739643 556708 1128220 942320 791343 626829 480213 930224 778134 662339 543235 428135 45680 45440 29764 8080 8070 8060 8030215 17.92 August 1603960 1392080 1179120 894498 701158 1300730 1119210 953915 739772 584280 1044600 898189 773884 624748 505781 852574 741220 647452 543362 452321 45680 45440 29764 8080 8070 8060 8030216 18 September 1822760 1556270 1333180 1063190 728221 1491930 1264750 1081820 876932 610394 1210470 1023400 884939 736308 531775 999559 849887 742277 632143 476940 45680 45440 29764 8080 8070 8060 8030217 18.08 October 2307680 1823050 1586260 1286710 913975 1939080 1505130 1312320 1074520 772219 1606770 1238550 1082050 903896 674927 1339630 1037930 911732 774464 604472 45680 45440 29764 8080 8070 8060 8030218 18.17 November 2855930 2280240 2021220 1556760 1159770 2439630 1931030 1683730 1324020 1002050 2043580 1615330 1401400 1141380 888288 1700370 1368240 1185310 1004120 806986 45680 45440 29764 8080 8070 8060 8030219 18.25 December 3793800 2679690 2336510 1904440 1372850 3609180 2322690 1992930 1641740 1193830 3186160 1985250 1696370 1423470 1072150 2787260 1712460 1463670 1241320 975515 45680 45440 29764 8080 8070 8060 8030220 18.33 January 3793800 3042540 2492820 2013770 1343640 3673740 2669840 2151720 1722290 1180310 3534010 2316700 1844040 1491780 1058960 3167530 2012290 1590970 1311040 971739 45680 45440 29764 8080 8070 8060 8030221 18.42 February 3749710 2823330 2394530 1788760 1217370 3341930 2441250 2038670 1546430 1064200 2914760 2076280 1721510 1347440 963290 2535590 1787320 1494770 1195300 886772 45680 45440 29764 8080 8070 8060 8030222 18.5 March 2724150 2318740 1912860 1383490 960932 2323260 1940530 1592610 1175220 829085 1936390 1616040 1314670 1009990 738954 1622860 1347670 1120160 891777 678079 45680 45440 29764 8080 8070 8060 8030223 18.58 April 2724540 2200600 1796300 1292470 901150 2291960 1831720 1481270 1100800 770689 1898300 1504130 1229030 946299 685605 1563410 1256880 1039500 833149 626304 45680 45440 29764 8080 8070 8060 8030224 18.67 May 2088850 1754970 1394010 1001360 735300 1729920 1426150 1134130 837185 620401 1408410 1144350 925505 716885 540999 1162240 943842 776980 629196 487288 45680 45440 29764 8080 8070 8060 8030225 18.75 June 1782830 1564290 1292860 976543 739458 1456710 1261260 1047220 812226 620422 1180510 1020470 858984 689272 537514 969668 843635 717012 601717 482308 45680 45440 29764 8080 8070 8060 8030226 18.83 July 1708420 1490030 1239640 912577 715931 1385610 1202660 998028 755596 599152 1120410 963221 813997 643227 521102 915233 792188 678833 562019 466681 45680 45440 29764 8080 8070 8060 8030227 18.92 August 1702070 1490240 1248510 923908 725780 1380100 1198000 1009330 768150 608029 1115760 963423 820283 649871 527684 911366 792336 681410 570217 471296 45680 45440 29764 8080 8070 8060 8030228 19 September 1735610 1524260 1316630 995653 743911 1421290 1237020 1063460 826310 624411 1155640 1000070 865823 696742 542948 948786 826448 719876 603862 485714 45680 45440 29764 8080 8070 8060 8030229 19.08 October 2387590 2032560 1729130 1298210 938473 2004500 1686520 1421620 1088920 799768 1657140 1383980 1166320 931693 703054 1376460 1152700 980240 812706 630786 45680 45440 29764 8080 8070 8060 8030230 19.17 November 3253280 2446480 2099020 1644810 1115930 2844460 2078440 1770530 1393430 960967 2425500 1749300 1485750 1188960 855999 2058040 1488280 1259700 1033120 779219 45680 45440 29764 8080 8070 8060 8030231 19.25 December 3793800 2964630 2407610 2033120 1421150 3673740 2615660 2079310 1740430 1239450 3563400 2275710 1803220 1486950 1091970 3157550 1984440 1578580 1299920 985427 45680 45440 29764 8080 8070 8060 8030232 19.33 January 3793800 3793800 2918640 2248230 1491290 3673740 3515810 2581330 1971290 1317110 3563400 3149150 2288270 1735360 1202790 3467290 2824260 2063550 1573020 1107150 45680 45440 29764 8080 8070 8060 8030233 19.42 February 2861830 2388880 2083100 1525320 1069490 2478990 2024060 1732410 1305810 924432 2101130 1699660 1437750 1124510 827499 1780730 1435980 1223530 997778 758089 45680 45440 29764 8080 8070 8060 8030234 19.5 March 3329810 2360430 1977940 1486160 1012510 2896180 1988230 1651670 1269550 871159 2438390 1650710 1379420 1096150 779274 2047350 1399880 1177530 962389 714318 45680 45440 29764 8080 8070 8060 8030235 19.58 April 2538610 2134440 1750830 1263130 850766 2146290 1763380 1440830 1061470 723999 1775710 1444310 1193600 910549 640807 1472430 1204880 1003740 796907 582899 45680 45440 29764 8080 8070 8060 8030236 19.67 May 2313860 1879070 1514550 1131920 805477 1935990 1541740 1243700 954441 680244 1604010 1252860 1027300 817006 595127 1330220 1040280 872060 714978 539004 45680 45440 29764 8080 8070 8060 8030237 19.75 June 1711000 1486760 1215980 916907 711563 1393710 1195000 981591 759308 595067 1122160 960878 800035 646447 517128 916633 786762 672267 562741 462782 45680 45440 29764 8080 8070 8060 8030238 19.83 July 1828470 1526340 1290650 966296 747208 1503400 1233750 1041280 800280 625370 1220110 997308 847088 683397 540183 1002800 824075 712704 593963 483025 45680 45440 29764 8080 8070 8060 8030239 19.92 August 1678730 1417480 1229020 900681 676979 1371310 1145220 988966 744969 563936 1113160 923341 796917 629109 486550 921619 765293 664312 545058 433819 45680 45440 29764 8080 8070 8060 8030

T-1

Asphalt Sub-Layers Modulus Vs Time

0

500,000

1,000,000

1,500,000

2,000,000

2,500,000

3,000,000

3,500,000

4,000,000

0 24 48 72 96 120 144 168 192 216 240

Pavement Age (month)

Mod

ulus

(psi

) AC1(1) h=0.5AC1(2) h=0.5AC1(3) h=1.0AC1(4) h=1.0

Fatigue Cracking: Project T-1

mo yr1 0.08 October 0.000442 0 13.4 0.0000472 0 2.5 0.0859 0.01 0 257.17 1.042 0.17 November 0.000841 0 2.5 0.000101 0 2.5 0.163 0.01 0 257.75 1.293 0.25 December 0.00128 0 2.5 0.000161 0 2.5 0.23 0.02 0 258.37 1.54 0.33 January 0.00171 0 2.5 0.000218 0 2.5 0.299 0.03 0 258.97 1.695 0.42 February 0.00212 0 2.5 0.000271 0 2.5 0.37 0.05 0 259.53 1.896 0.5 March 0.00251 0 2.5 0.000316 0 2.5 0.446 0.06 0 260.06 2.097 0.58 April 0.0029 0 2.5 0.000363 0 2.5 0.52 0.07 0 260.58 2.288 0.67 May 0.00326 0 2.5 0.000402 0 2.5 0.6 0.09 0 261.06 2.489 0.75 June 0.00362 0 2.5 0.000439 0 2.5 0.681 0.11 0 261.54 2.6810 0.83 July 0.00398 0 2.5 0.000471 0 2.5 0.765 0.12 0 262.01 2.8811 0.92 August 0.00433 0 2.5 0.000504 0 2.5 0.848 0.14 0 262.47 3.0712 1 September 0.00468 0 2.5 0.000541 0 2.5 0.928 0.16 0 262.93 3.2513 1.08 October 0.00505 0 2.5 0.000584 0 2.5 1 0.18 0 263.41 3.4114 1.17 November 0.00545 0 2.5 0.000636 0 2.5 1.07 0.2 0 263.93 3.5615 1.25 December 0.00589 0 2.5 0.000695 0 2.5 1.13 0.21 0 264.49 3.6916 1.33 January 0.00633 0 2.5 0.000757 0 2.5 1.19 0.22 0 265.05 3.8117 1.42 February 0.00677 0 2.5 0.000817 0 2.5 1.24 0.24 0 265.61 3.9218 1.5 March 0.00719 0.01 2.5 0.000873 0 2.5 1.3 0.25 0 266.14 4.0419 1.58 April 0.00756 0.01 2.5 0.000918 0 2.5 1.37 0.27 0 266.61 4.1820 1.67 May 0.00791 0.01 2.5 0.000955 0 2.5 1.44 0.29 0 267.05 4.3221 1.75 June 0.00825 0.01 2.5 0.000986 0 2.5 1.53 0.32 0 267.48 4.4922 1.83 July 0.00859 0.01 2.5 0.00102 0 2.5 1.61 0.34 0 267.9 4.6523 1.92 August 0.00893 0.01 2.5 0.00105 0 2.5 1.69 0.36 0 268.33 4.824 2 September 0.00926 0.01 2.5 0.00108 0 2.5 1.77 0.39 0 268.74 4.9525 2.08 October 0.00962 0.01 2.5 0.00112 0 2.5 1.85 0.41 0 269.19 5.126 2.17 November 0.01 0.01 2.5 0.00117 0 2.5 1.92 0.43 0 269.66 5.2327 2.25 December 0.0104 0.01 2.5 0.00122 0 2.5 1.99 0.45 0 270.15 5.3528 2.33 January 0.0109 0.01 2.5 0.00128 0 2.5 2.04 0.47 0 270.77 5.4429 2.42 February 0.0113 0.01 2.5 0.00134 0 2.5 2.1 0.49 0 271.26 5.5430 2.5 March 0.0117 0.01 2.5 0.00139 0 2.5 2.16 0.51 0 271.75 5.6531 2.58 April 0.0121 0.01 2.5 0.00144 0 2.5 2.24 0.53 0 272.24 5.7932 2.67 May 0.0124 0.01 2.5 0.00148 0 2.5 2.31 0.56 0 272.61 5.9133 2.75 June 0.0128 0.01 2.5 0.00151 0 2.5 2.4 0.59 0 273.1 6.0634 2.83 July 0.0131 0.01 2.5 0.00155 0 2.5 2.48 0.61 0 273.46 6.1935 2.92 August 0.0135 0.01 2.5 0.00158 0 2.5 2.56 0.64 0 273.94 6.3236 3 September 0.0138 0.01 2.5 0.00162 0 2.5 2.64 0.67 0 274.31 6.4537 3.08 October 0.0142 0.01 2.5 0.00166 0 2.5 2.72 0.7 0 274.79 6.5838 3.17 November 0.0146 0.02 2.5 0.00172 0 2.5 2.79 0.72 0 275.28 6.6939 3.25 December 0.0151 0.02 2.5 0.00178 0 2.5 2.84 0.74 0 275.88 6.7840 3.33 January 0.0156 0.02 2.5 0.00185 0 0 2.9 0.76 0 276.48 6.8741 3.42 February 0.016 0.02 2.5 0.00191 0 0 2.96 0.78 0 276.96 6.9642 3.5 March 0.0165 0.02 2.5 0.00197 0 0 3.02 0.81 0 277.56 7.0643 3.58 April 0.0169 0.02 2.5 0.00202 0 0 3.1 0.83 0 278.04 7.1844 3.67 May 0.0172 0.02 2.5 0.00206 0 0 3.18 0.86 0 278.39 7.345 3.75 June 0.0176 0.02 2.5 0.00209 0 0 3.26 0.89 0 278.87 7.4246 3.83 July 0.018 0.02 2.5 0.00213 0 0 3.35 0.93 0 279.35 7.5547 3.92 August 0.0183 0.02 2.5 0.00217 0 0 3.43 0.96 0 279.7 7.6748 4 September 0.0187 0.02 2.5 0.0022 0 0 3.52 0.99 0 280.18 7.849 4.08 October 0.0191 0.02 2.5 0.00225 0 0 3.59 1.02 0 280.65 7.9150 4.17 November 0.0196 0.02 2.5 0.00231 0 0 3.66 1.05 0 281.24 8.0151 4.25 December 0.0201 0.03 2.5 0.00239 0 0 3.71 1.07 0 281.83 8.0852 4.33 January 0.0206 0.03 2.5 0.00247 0 0 3.75 1.08 0 282.42 8.1353 4.42 February 0.0211 0.03 2.5 0.00253 0 0 3.82 1.11 0 283.01 8.2454 4.5 March 0.0215 0.03 2.5 0.00259 0 0 3.89 1.14 0 283.48 8.3455 4.58 April 0.0219 0.03 2.5 0.00264 0 0 3.97 1.17 0 283.94 8.4556 4.67 May 0.0223 0.03 2.5 0.00269 0 0 4.05 1.2 0 284.41 8.5657 4.75 June 0.0227 0.03 2.5 0.00273 0 0 4.13 1.23 0 284.88 8.6658 4.83 July 0.0231 0.03 2.5 0.00277 0 0 4.22 1.27 0 285.35 8.7959 4.92 August 0.0235 0.03 2.5 0.0028 0 0 4.31 1.31 0 285.81 8.9260 5 September 0.0238 0.03 2.5 0.00284 0 0 4.4 1.34 0 286.16 9.0361 5.08 October 0.0242 0.03 2.5 0.00289 0 0 4.48 1.38 0 286.63 9.1462 5.17 November 0.0247 0.03 2.5 0.00295 0 0 4.55 1.41 0 287.21 9.24

Fatigue Cracking: Project T-1Top Down at Surface Top Down at 0.5" Bottom Up at hac Reliability

Pavementage

Month

MaximumDamage

(%)

MaximumCracking

(ft/mi)Location

(in)

MaximumDamage

(%)

MaximumCracking

(ft/mi)Location

(in)

Bottom UpCracking

(%)

MaximumDamage

(%)

MaximumCracking

(%)Location

(in)

Top DownCracking

(ft/mi)


63 5.25 December 0.0252 0.04 2.5 0.00302 0 0 4.61 1.43 0 287.79 9.3164 5.33 January 0.0257 0.04 2.5 0.00309 0 0 4.68 1.46 0 288.37 9.465 5.42 February 0.0262 0.04 2.5 0.00315 0 0 4.75 1.49 0 288.94 9.4966 5.5 March 0.0266 0.04 2.5 0.0032 0 0 4.83 1.52 0 289.41 9.5967 5.58 April 0.0271 0.04 2.5 0.00326 0 0 4.9 1.56 0 289.98 9.6968 5.67 May 0.0275 0.04 2.5 0.0033 0 0 4.99 1.59 0 290.44 9.869 5.75 June 0.0279 0.04 2.5 0.00334 0 0 5.08 1.63 0 290.9 9.9270 5.83 July 0.0282 0.04 2.5 0.00338 0 0 5.17 1.67 0 291.25 10.0371 5.92 August 0.0286 0.04 2.5 0.00342 0 0 5.26 1.71 0 291.71 10.1572 6 September 0.029 0.04 2.5 0.00346 0 0 5.35 1.75 0 292.17 10.2673 6.08 October 0.0295 0.05 2.5 0.00351 0 0 5.44 1.79 0 292.74 10.3774 6.17 November 0.03 0.05 2.5 0.00358 0 0 5.51 1.82 0 293.31 10.4575 6.25 December 0.0305 0.05 2.5 0.00366 0 0 5.56 1.85 0 293.88 10.5276 6.33 January 0.0311 0.05 2.5 0.00374 0 0 5.62 1.87 0 294.56 10.5977 6.42 February 0.0316 0.05 2.5 0.00382 0 0 5.68 1.9 0 295.13 10.6778 6.5 March 0.0321 0.05 2.5 0.00389 0 0 5.75 1.93 0 295.7 10.7579 6.58 April 0.0326 0.05 2.5 0.00395 0 0 5.83 1.96 0 296.27 10.8480 6.67 May 0.033 0.05 2.5 0.00399 0 0 5.92 2 0 296.72 10.9581 6.75 June 0.0334 0.05 2.5 0.00403 0 0 6.01 2.05 0 297.18 11.0682 6.83 July 0.0338 0.06 2.5 0.00407 0 0 6.12 2.1 0 297.63 11.1983 6.92 August 0.0342 0.06 2.5 0.0041 0 0 6.21 2.14 0 298.08 11.384 7 September 0.0346 0.06 2.5 0.00415 0 0 6.31 2.19 0 298.53 11.4285 7.08 October 0.0351 0.06 2.5 0.0042 0 0 6.4 2.23 0 299.1 11.5286 7.17 November 0.0356 0.06 2.5 0.00426 0 0 6.48 2.27 0 299.66 11.6287 7.25 December 0.0361 0.06 2.5 0.00433 0 0 6.55 2.3 0 300.22 11.6988 7.33 January 0.0366 0.06 2.5 0.00441 0 0 6.62 2.33 0 300.78 11.7789 7.42 February 0.0372 0.06 2.5 0.00449 0 0 6.68 2.36 0 301.46 11.8490 7.5 March 0.0377 0.07 2.5 0.00456 0 0 6.75 2.39 0 302.02 11.9291 7.58 April 0.0382 0.07 2.5 0.00461 0 0 6.84 2.44 0 302.58 12.0392 7.67 May 0.0386 0.07 2.5 0.00466 0 0 6.93 2.48 0 303.03 12.1393 7.75 June 0.0391 0.07 2.5 0.00471 0 0 7.03 2.53 0 303.58 12.2494 7.83 July 0.0395 0.07 2.5 0.00475 0 0 7.13 2.58 0 304.03 12.3695 7.92 August 0.0399 0.07 2.5 0.00479 0 0 7.23 2.63 0 304.48 12.4796 8 September 0.0403 0.07 2.5 0.00484 0 0 7.32 2.67 0 304.92 12.5697 8.08 October 0.0408 0.07 2.5 0.0049 0 0 7.41 2.72 0 305.48 12.6798 8.17 November 0.0413 0.08 2.5 0.00497 0 0 7.49 2.75 0 306.04 12.7599 8.25 December 0.0419 0.08 2.5 0.00505 0 0 7.56 2.78 0 306.7 12.82100 8.33 January 0.0425 0.08 2.5 0.00514 0 0 7.62 2.82 0 307.37 12.9101 8.42 February 0.0431 0.08 2.5 0.00522 0 0 7.68 2.85 0 308.03 12.96102 8.5 March 0.0436 0.08 2.5 0.00529 0 0 7.76 2.89 0 308.59 13.05103 8.58 April 0.0441 0.08 2.5 0.00535 0 0 7.85 2.93 0 309.14 13.14104 8.67 May 0.0446 0.09 2.5 0.00541 0 0 7.94 2.98 0 309.69 13.24105 8.75 June 0.0451 0.09 2.5 0.00545 0 0 8.04 3.03 0 310.24 13.35106 8.83 July 0.0455 0.09 2.5 0.0055 0 0 8.14 3.08 0 310.68 13.46107 8.92 August 0.0459 0.09 2.5 0.00554 0 0 8.25 3.13 0 311.13 13.57108 9 September 0.0464 0.09 2.5 0.00559 0 0 8.35 3.18 0 311.68 13.68109 9.08 October 0.0469 0.09 2.5 0.00565 0 0 8.44 3.23 0 312.23 13.77110 9.17 November 0.0474 0.09 2.5 0.00573 0 0 8.52 3.27 0 312.77 13.86111 9.25 December 0.0481 0.1 2.5 0.00582 0 0 8.58 3.3 0 313.54 13.92112 9.33 January 0.0487 0.1 2.5 0.00593 0 0 8.63 3.33 0 314.2 13.98113 9.42 February 0.0493 0.1 2.5 0.006 0 0 8.71 3.37 0 314.86 14.06114 9.5 March 0.0499 0.1 2.5 0.00608 0 0 8.79 3.41 0 315.51 14.14115 9.58 April 0.0504 0.1 2.5 0.00614 0 0 8.88 3.46 0 316.06 14.24116 9.67 May 0.0509 0.1 2.5 0.0062 0 0 8.97 3.5 0 316.6 14.32117 9.75 June 0.0513 0.11 2.5 0.00625 0 0 9.08 3.56 0 317.04 14.44118 9.83 July 0.0518 0.11 2.5 0.0063 0 0 9.19 3.62 0 317.58 14.56119 9.92 August 0.0523 0.11 2.5 0.00634 0 0 9.3 3.67 0 318.13 14.66120 10 September 0.0527 0.11 2.5 0.00639 0 0 9.4 3.73 0 318.56 14.77121 10.1 October 0.0532 0.11 2.5 0.00645 0 0 9.5 3.78 0 319.11 14.87122 10.2 November 0.0538 0.11 2.5 0.00652 0 0 9.59 3.82 0 319.76 14.95123 10.3 December 0.0544 0.12 2.5 0.00661 0 0 9.66 3.86 0 320.41 15.03124 10.3 January 0.0551 0.12 2.5 0.0067 0 0 9.73 3.9 0 321.16 15.1125 10.4 February 0.0556 0.12 2.5 0.00678 0 0 9.81 3.94 0 321.7 15.18126 10.5 March 0.0562 0.12 2.5 0.00684 0 0 9.91 3.99 0 322.35 15.27127 10.6 April 0.0567 0.12 2.5 0.00691 0.01 0 10 4.04 0 322.89 15.37128 10.7 May 0.0572 0.12 2.5 0.00697 0.01 0 10.1 4.1 0 323.43 15.47129 10.8 June 0.0577 0.13 2.5 0.00702 0.01 0 10.2 4.16 0 323.97 15.58130 10.8 July 0.0582 0.13 2.5 0.00706 0.01 0 10.3 4.22 0 324.51 15.68


131 10.9 August 0.0586 0.13 2.5 0.00711 0.01 0 10.4 4.28 0 324.94 15.79132 11 September 0.0591 0.13 2.5 0.00716 0.01 0 10.5 4.34 0 325.48 15.89133 11.1 October 0.0597 0.13 2.5 0.00723 0.01 0 10.7 4.39 0 326.12 16.03134 11.2 November 0.0603 0.14 2.5 0.00731 0.01 0 10.7 4.44 0 326.76 16.08135 11.3 December 0.061 0.14 2.5 0.00741 0.01 0 10.8 4.47 0 327.51 16.15136 11.3 January 0.0616 0.14 2.5 0.00751 0.01 0 10.9 4.51 0 328.16 16.23137 11.4 February 0.0623 0.14 2.5 0.00761 0.01 0 10.9 4.55 0 328.91 16.27138 11.5 March 0.0629 0.14 2.5 0.0077 0.01 0 11 4.59 0 329.55 16.36139 11.6 April 0.0635 0.15 2.5 0.00777 0.01 0 11.1 4.64 0 330.19 16.45140 11.7 May 0.064 0.15 2.5 0.00783 0.01 0 11.2 4.7 0 330.72 16.55141 11.8 June 0.0645 0.15 2.5 0.00787 0.01 0 11.3 4.77 0 331.25 16.66142 11.8 July 0.065 0.15 2.5 0.00792 0.01 0 11.5 4.84 0 331.78 16.81143 11.9 August 0.0655 0.15 2.5 0.00796 0.01 0 11.6 4.9 0 332.32 16.91144 12 September 0.066 0.16 2.5 0.00802 0.01 0 11.7 4.96 0 332.85 17.01145 12.1 October 0.0665 0.16 2.5 0.00808 0.01 0 11.8 5.02 0 333.38 17.11146 12.2 November 0.0671 0.16 2.5 0.00816 0.01 0 11.9 5.08 0 334.01 17.21147 12.3 December 0.0678 0.16 2.5 0.00825 0.01 0 12 5.13 0 334.76 17.3148 12.3 January 0.0685 0.16 2.5 0.00834 0.01 0 12.1 5.17 0 335.5 17.37149 12.4 February 0.0691 0.17 2.5 0.00844 0.01 0 12.1 5.21 0 336.13 17.41150 12.5 March 0.0698 0.17 2.5 0.00853 0.01 0 12.2 5.26 0 336.87 17.5151 12.6 April 0.0704 0.17 2.5 0.00859 0.01 0 12.3 5.31 0 337.5 17.59152 12.7 May 0.0709 0.17 2.5 0.00866 0.01 0 12.4 5.38 0 338.03 17.7153 12.8 June 0.0714 0.17 2.5 0.00871 0.01 0 12.6 5.44 0 338.56 17.83154 12.8 July 0.072 0.18 2.5 0.00877 0.01 0 12.7 5.51 0 339.19 17.93155 12.9 August 0.0725 0.18 2.5 0.00882 0.01 0 12.8 5.58 0 339.71 18.04156 13 September 0.073 0.18 2.5 0.00887 0.01 0 12.9 5.65 0 340.24 18.15157 13.1 October 0.0736 0.18 2.5 0.00894 0.01 0 13 5.71 0 340.87 18.24158 13.2 November 0.0742 0.19 2.5 0.00903 0.01 0 13.1 5.76 0 341.5 18.33159 13.3 December 0.0749 0.19 2.5 0.00913 0.01 0 13.2 5.81 0 342.24 18.41160 13.3 January 0.0757 0.19 2.5 0.00924 0.01 0 13.3 5.85 0 343.07 18.49161 13.4 February 0.0764 0.19 2.5 0.00935 0.01 0 13.3 5.89 0 343.8 18.53162 13.5 March 0.0771 0.2 2.5 0.00943 0.01 0 13.4 5.95 0 344.54 18.62163 13.6 April 0.0777 0.2 2.5 0.00951 0.01 0 13.5 6.01 0 345.16 18.71164 13.7 May 0.0783 0.2 2.5 0.00958 0.01 0 13.7 6.07 0 345.79 18.84165 13.8 June 0.0788 0.2 2.5 0.00963 0.01 0 13.8 6.14 0 346.31 18.94166 13.8 July 0.0793 0.2 2.5 0.00969 0.01 0 13.9 6.21 0 346.83 19.05167 13.9 August 0.0798 0.21 2.5 0.00974 0.01 0 14 6.29 0 347.35 19.16168 14 September 0.0804 0.21 2.5 0.0098 0.01 0 14.1 6.36 0 347.97 19.26169 14.1 October 0.081 0.21 2.5 0.00988 0.01 0 14.3 6.42 0 348.6 19.38170 14.2 November 0.0817 0.21 2.5 0.00997 0.01 0 14.4 6.47 0 349.32 19.46171 14.3 December 0.0825 0.22 2.5 0.0101 0.01 0 14.4 6.52 0 350.15 19.51172 14.3 January 0.0833 0.22 2.5 0.0102 0.01 0 14.5 6.55 0 350.98 19.58173 14.4 February 0.084 0.22 2.5 0.0103 0.01 0 14.6 6.61 0 351.7 19.67174 14.5 March 0.0847 0.23 2.5 0.0104 0.01 0 14.7 6.67 0 352.43 19.76175 14.6 April 0.0853 0.23 2.5 0.0105 0.01 0 14.8 6.72 0 353.05 19.84176 14.7 May 0.0859 0.23 2.5 0.0106 0.01 0 14.9 6.79 0 353.67 19.94177 14.8 June 0.0865 0.23 2.5 0.0106 0.01 0 15 6.87 0 354.28 20.05178 14.8 July 0.0871 0.24 2.5 0.0107 0.01 0 15.2 6.94 0 354.9 20.18179 14.9 August 0.0876 0.24 2.5 0.0107 0.01 0 15.3 7.02 0 355.42 20.29180 15 September 0.0882 0.24 2.5 0.0108 0.01 0 15.4 7.1 0 356.03 20.4181 15.1 October 0.0888 0.24 2.5 0.0109 0.01 0 15.5 7.16 0 356.65 20.48182 15.2 November 0.0895 0.25 2.5 0.011 0.01 0 15.6 7.22 0 357.37 20.57183 15.3 December 0.0903 0.25 2.5 0.0111 0.01 0 15.7 7.28 0 358.19 20.66184 15.3 January 0.091 0.25 2.5 0.0112 0.01 0 15.8 7.33 0 358.91 20.74185 15.4 February 0.0918 0.26 2.5 0.0113 0.01 0 15.9 7.38 0 359.73 20.82186 15.5 March 0.0924 0.26 2.5 0.0113 0.01 0 16 7.46 0 360.34 20.93187 15.6 April 0.0931 0.26 2.5 0.0114 0.01 0 16.1 7.52 0 361.05 21.01188 15.7 May 0.0937 0.26 2.5 0.0115 0.01 0 16.3 7.59 0 361.67 21.14189 15.8 June 0.0943 0.27 2.5 0.0116 0.01 0 16.4 7.67 0 362.28 21.24190 15.8 July 0.0949 0.27 2.5 0.0116 0.01 0 16.5 7.75 0 362.89 21.35191 15.9 August 0.0954 0.27 2.5 0.0117 0.01 0 16.7 7.84 0 363.4 21.49192 16 September 0.096 0.27 2.5 0.0117 0.01 0 16.8 7.91 0 364.01 21.59193 16.1 October 0.0967 0.28 2.5 0.0118 0.01 0 16.9 7.99 0 364.72 21.7194 16.2 November 0.0974 0.28 2.5 0.0119 0.01 0 17 8.04 0 365.43 21.77195 16.3 December 0.0983 0.28 2.5 0.0121 0.01 0 17.1 8.1 0 366.35 21.86196 16.3 January 0.0991 0.29 2.5 0.0122 0.01 0 17.2 8.14 0 367.16 21.92197 16.4 February 0.0999 0.29 2.5 0.0123 0.01 0 17.3 8.19 0 367.97 22198 16.5 March 0.101 0.29 2.5 0.0124 0.01 0 17.3 8.25 0 369.08 22.06


199 16.6 April 0.101 0.3 2.5 0.0125 0.01 0 17.5 8.32 0 369.08 22.18200 16.7 May 0.102 0.3 2.5 0.0126 0.01 0 17.6 8.4 0 370.09 22.28201 16.8 June 0.103 0.3 2.5 0.0126 0.01 0 17.7 8.48 0 371.1 22.39202 16.8 July 0.103 0.3 2.5 0.0127 0.01 0 17.9 8.57 0 371.1 22.53203 16.9 August 0.104 0.31 2.5 0.0127 0.01 0 18 8.66 0 372.11 22.64204 17 September 0.104 0.31 2.5 0.0128 0.01 0 18.2 8.74 0 372.11 22.77205 17.1 October 0.105 0.31 2.5 0.0129 0.01 0 18.3 8.83 0 373.11 22.88206 17.2 November 0.106 0.32 2.5 0.013 0.01 0 18.4 8.9 0 374.12 22.98207 17.3 December 0.107 0.32 2.5 0.0131 0.01 0 18.5 8.96 0 375.12 23.06208 17.3 January 0.107 0.32 2.5 0.0132 0.01 0 18.6 9.01 0 375.12 23.13209 17.4 February 0.108 0.33 2.5 0.0133 0.01 0 18.7 9.07 0 376.12 23.22210 17.5 March 0.109 0.33 2.5 0.0134 0.01 0 18.8 9.13 0 377.13 23.3211 17.6 April 0.11 0.34 2.5 0.0135 0.01 0 18.9 9.21 0 378.12 23.4212 17.7 May 0.11 0.34 2.5 0.0136 0.01 0 19.1 9.29 0 378.13 23.53213 17.8 June 0.111 0.34 2.5 0.0137 0.01 0 19.2 9.37 0 379.12 23.63214 17.8 July 0.112 0.34 2.5 0.0137 0.01 0 19.4 9.46 0 380.12 23.76215 17.9 August 0.112 0.35 2.5 0.0138 0.01 0 19.5 9.55 0 380.12 23.87216 18 September 0.113 0.35 2.5 0.0138 0.01 0 19.7 9.64 0 381.12 24.01217 18.1 October 0.114 0.35 2.5 0.0139 0.01 0 19.8 9.72 0 382.11 24.11218 18.2 November 0.114 0.36 2.5 0.014 0.01 0 19.9 9.79 0 382.12 24.2219 18.3 December 0.115 0.36 2.5 0.0142 0.01 0 20 9.85 0 383.11 24.28220 18.3 January 0.116 0.37 2.5 0.0143 0.02 0 20.1 9.9 0 384.1 24.35221 18.4 February 0.117 0.37 2.5 0.0144 0.02 0 20.2 9.96 0 385.09 24.43222 18.5 March 0.118 0.37 2.5 0.0145 0.02 0 20.3 10 0 386.08 24.49223 18.6 April 0.119 0.38 2.5 0.0146 0.02 0 20.4 10.1 0 387.07 24.61224 18.7 May 0.119 0.38 2.5 0.0147 0.02 0 20.5 10.2 0 387.07 24.74225 18.8 June 0.12 0.38 2.5 0.0148 0.02 0 20.7 10.3 0 388.06 24.88226 18.8 July 0.121 0.39 2.5 0.0149 0.02 0 20.8 10.4 0 389.05 25227 18.9 August 0.121 0.39 2.5 0.0149 0.02 0 21 10.5 0 389.05 25.14228 19 September 0.122 0.39 2.5 0.015 0.02 0 21.1 10.6 0 390.03 25.26229 19.1 October 0.123 0.4 2.5 0.0151 0.02 0 21.3 10.6 0 391.02 25.3230 19.2 November 0.124 0.4 2.5 0.0152 0.02 0 21.4 10.7 0 392 25.41231 19.3 December 0.125 0.41 2.5 0.0153 0.02 0 21.5 10.8 0 392.98 25.53232 19.3 January 0.126 0.41 2.5 0.0155 0.02 0 21.6 10.8 0 393.96 25.55233 19.4 February 0.126 0.41 2.5 0.0156 0.02 0 21.7 10.9 0 393.97 25.67234 19.5 March 0.127 0.42 2.5 0.0157 0.02 0 21.8 10.9 0 394.95 25.69235 19.6 April 0.128 0.42 2.5 0.0158 0.02 0 21.9 11 0 395.93 25.81236 19.7 May 0.129 0.43 2.5 0.0159 0.02 0 22 11.1 0 396.9 25.93237 19.8 June 0.13 0.43 2.5 0.016 0.02 0 22.2 11.2 0 397.88 26.07238 19.8 July 0.13 0.43 2.5 0.0161 0.02 0 22.4 11.3 0 397.88 26.2239 19.9 August 0.131 0.44 2.5 0.0161 0.02 0 22.5 11.4 0 398.85 26.32240 20 September 0.132 0.44 2.5 0.0162 0.02 0 22.7 11.5 0 399.83 26.46

T-1

Surface Down Cracking - Longitudinal

0

10

20

30

40

50

60

70

80

90

100

0 24 48 72 96 120 144 168 192 216 240 264


Max

imum

Dam

age(

%)

SurfaceDepth = 0.5"

T-1

Surface Down Cracking - Longitudinal

0

200

400

600

800

1000

1200

1400

1600

1800

2000

0 24 48 72 96 120 144 168 192 216 240 264


Long

itudi

nal C

rack

ing

(ft/m

i)

SurfaceDepth = 0.5"Surface at ReliabilityDesign Limit

T-1

Bottom Up Damage for Alligator Cracking

0

10

20

30

40

50

60

70

80

90

100

0 24 48 72 96 120 144 168 192 216 240 264


Max

imum

Dam

age

(%)

T-1

Bottom Up Cracking - Alligator

0

10

20

30

40

50

60

70

80

90

100

0 24 48 72 96 120 144 168 192 216 240 264


Alli

gato

r Cra

ckin

g (%

)

Maximum CrackingBottom Up ReliabilityMaximum Cracking Limit

Thermal Cracking: Project T-1

mo yr1 0.08 October 0 0 0 14.62 0.17 November 0 0 0 14.63 0.25 December 0 0 0 14.64 0.33 January 0 0 0 14.65 0.42 February 0 0 0 14.66 0.5 March 0 0 0 14.67 0.58 April 0 0 0 14.68 0.67 May 0 0 0 14.69 0.75 June 0 0 0 14.610 0.83 July 0 0 0 14.611 0.92 August 0 0 0 14.612 1 September 0 0 0 14.613 1.08 October 0 0 0 14.614 1.17 November 0 0 0 14.615 1.25 December 0 0 0 14.616 1.33 January 0 0 0 14.617 1.42 February 0 0 0 14.618 1.5 March 0 0 0 14.619 1.58 April 0 0 0 14.620 1.67 May 0 0 0 14.621 1.75 June 0 0 0 14.622 1.83 July 0 0 0 14.623 1.92 August 0 0 0 14.624 2 September 0 0 0 14.625 2.08 October 0 0 0 14.626 2.17 November 0 0 0 14.627 2.25 December 0 0 0 14.628 2.33 January 0 0 0 14.629 2.42 February 0 0 0 14.630 2.5 March 0 0 0 14.631 2.58 April 0 0 0 14.632 2.67 May 0 0 0 14.633 2.75 June 0 0 0 14.634 2.83 July 0 0 0 14.635 2.92 August 0 0 0 14.636 3 September 0 0 0 14.637 3.08 October 0 0 0 14.638 3.17 November 0 0 0 14.639 3.25 December 0 0 0 14.640 3.33 January 0 0 0 14.641 3.42 February 0 0 0 14.642 3.5 March 0 0 0 14.643 3.58 April 0 0 0 14.644 3.67 May 0 0 0 14.645 3.75 June 0 0 0 14.646 3.83 July 0 0 0 14.647 3.92 August 0 0 0 14.648 4 September 0 0 0 14.649 4.08 October 0 0 0 14.650 4.17 November 0 0 0 14.651 4.25 December 0 0 0 14.652 4.33 January 0 0 0 14.653 4.42 February 0 0 0 14.654 4.5 March 0 0 0 14.6

Thermal Cracking: Project T-1Pavement

ageMonth

Crack DepthCave

(in)

DepthRatioC/hac

Crack Length(ft/mi)

AverageCrack Spacing

(ft)

Crack Lengthat Reliability

(ft/mi)


55 4.58 April 0 0 0 14.656 4.67 May 0 0 0 14.657 4.75 June 0 0 0 14.658 4.83 July 0 0 0 14.659 4.92 August 0 0 0 14.660 5 September 0 0 0 14.661 5.08 October 0 0 0 14.662 5.17 November 0 0 0 14.663 5.25 December 0 0 0 14.664 5.33 January 0 0 0 14.665 5.42 February 0 0 0 14.666 5.5 March 0 0 0 14.667 5.58 April 0 0 0 14.668 5.67 May 0 0 0 14.669 5.75 June 0 0 0 14.670 5.83 July 0 0 0 14.671 5.92 August 0 0 0 14.672 6 September 0 0 0 14.673 6.08 October 0 0 0 14.674 6.17 November 0 0 0 14.675 6.25 December 0 0 0 14.676 6.33 January 0 0 0 14.677 6.42 February 0 0 0 14.678 6.5 March 0 0 0 14.679 6.58 April 0 0 0 14.680 6.67 May 0 0 0 14.681 6.75 June 0 0 0 14.682 6.83 July 0 0 0 14.683 6.92 August 0 0 0 14.684 7 September 0 0 0 14.685 7.08 October 0 0 0 14.686 7.17 November 0 0 0 14.687 7.25 December 0 0 0 14.688 7.33 January 0 0 0 14.689 7.42 February 0 0 0 14.690 7.5 March 0 0 0 14.691 7.58 April 0 0 0 14.692 7.67 May 0 0 0 14.693 7.75 June 0 0 0 14.694 7.83 July 0 0 0 14.695 7.92 August 0 0 0 14.696 8 September 0 0 0 14.697 8.08 October 0 0 0 14.698 8.17 November 0 0 0 14.699 8.25 December 0 0 0 14.6100 8.33 January 0 0 0 14.6101 8.42 February 0 0 0 14.6102 8.5 March 0 0 0 14.6103 8.58 April 0 0 0 14.6104 8.67 May 0 0 0 14.6105 8.75 June 0 0 0 14.6106 8.83 July 0 0 0 14.6107 8.92 August 0 0 0 14.6108 9 September 0 0 0 14.6109 9.08 October 0 0 0 14.6110 9.17 November 0 0 0 14.6111 9.25 December 0 0 0 14.6112 9.33 January 0 0 0 14.6


113 9.42 February 0 0 0 14.6114 9.5 March 0 0 0 14.6115 9.58 April 0 0 0 14.6116 9.67 May 0 0 0 14.6117 9.75 June 0 0 0 14.6118 9.83 July 0 0 0 14.6119 9.92 August 0 0 0 14.6120 10 September 0 0 0 14.6121 10.1 October 0 0 0 14.6122 10.2 November 0 0 0 14.6123 10.3 December 0 0 0 14.6124 10.3 January 0 0 0 14.6125 10.4 February 0 0 0 14.6126 10.5 March 0 0 0 14.6127 10.6 April 0 0 0 14.6128 10.7 May 0 0 0 14.6129 10.8 June 0 0 0 14.6130 10.8 July 0 0 0 14.6131 10.9 August 0 0 0 14.6132 11 September 0 0 0 14.6133 11.1 October 0 0 0 14.6134 11.2 November 0 0 0 14.6135 11.3 December 0 0 0 14.6136 11.3 January 0 0 0 14.6137 11.4 February 0 0 0 14.6138 11.5 March 0 0 0 14.6139 11.6 April 0 0 0 14.6140 11.7 May 0 0 0 14.6141 11.8 June 0 0 0 14.6142 11.8 July 0 0 0 14.6143 11.9 August 0 0 0 14.6144 12 September 0 0 0 14.6145 12.1 October 0 0 0 14.6146 12.2 November 0 0 0 14.6147 12.3 December 0 0 0 14.6148 12.3 January 0 0 0 14.6149 12.4 February 0 0 0 14.6150 12.5 March 0 0 0 14.6151 12.6 April 0 0 0 14.6152 12.7 May 0 0 0 14.6153 12.8 June 0 0 0 14.6154 12.8 July 0 0 0 14.6155 12.9 August 0 0 0 14.6156 13 September 0 0 0 14.6157 13.1 October 0 0 0 14.6158 13.2 November 0 0 0 14.6159 13.3 December 0 0 0 14.6160 13.3 January 0 0 0 14.6161 13.4 February 0 0 0 14.6162 13.5 March 0 0 0 14.6163 13.6 April 0 0 0 14.6164 13.7 May 0 0 0 14.6165 13.8 June 0 0 0 14.6166 13.8 July 0 0 0 14.6167 13.9 August 0 0 0 14.6168 14 September 0 0 0 14.6169 14.1 October 0 0 0 14.6170 14.2 November 0 0 0 14.6


171 14.3 December 0 0 0 14.6172 14.3 January 0 0 0 14.6173 14.4 February 0 0 0 14.6174 14.5 March 0 0 0 14.6175 14.6 April 0 0 0 14.6176 14.7 May 0 0 0 14.6177 14.8 June 0 0 0 14.6178 14.8 July 0 0 0 14.6179 14.9 August 0 0 0 14.6180 15 September 0 0 0 14.6181 15.1 October 0 0 0 14.6182 15.2 November 0 0 0 14.6183 15.3 December 0 0 0 14.6184 15.3 January 0 0 0 14.6185 15.4 February 0 0 0 14.6186 15.5 March 0 0 0 14.6187 15.6 April 0 0 0 14.6188 15.7 May 0 0 0 14.6189 15.8 June 0 0 0 14.6190 15.8 July 0 0 0 14.6191 15.9 August 0 0 0 14.6192 16 September 0 0 0 14.6193 16.1 October 0 0 0 14.6194 16.2 November 0 0 0 14.6195 16.3 December 0 0 0 14.6196 16.3 January 0 0 0 14.6197 16.4 February 0 0 0 14.6198 16.5 March 0 0 0 14.6199 16.6 April 0 0 0 14.6200 16.7 May 0 0 0 14.6201 16.8 June 0 0 0 14.6202 16.8 July 0 0 0 14.6203 16.9 August 0 0 0 14.6204 17 September 0 0 0 14.6205 17.1 October 0 0 0 14.6206 17.2 November 0 0 0 14.6207 17.3 December 0 0 0 14.6208 17.3 January 0 0 0 14.6209 17.4 February 0 0 0 14.6210 17.5 March 0 0 0 14.6211 17.6 April 0 0 0 14.6212 17.7 May 0 0 0 14.6213 17.8 June 0 0 0 14.6214 17.8 July 0 0 0 14.6215 17.9 August 0 0 0 14.6216 18 September 0 0 0 14.6217 18.1 October 0 0 0 14.6218 18.2 November 0 0 0 14.6219 18.3 December 0 0 0 14.6220 18.3 January 0 0 0 14.6221 18.4 February 0 0 0 14.6222 18.5 March 0 0 0 14.6223 18.6 April 0 0 0 14.6224 18.7 May 0 0 0 14.6225 18.8 June 0 0 0 14.6226 18.8 July 0 0 0 14.6227 18.9 August 0 0 0 14.6228 19 September 0 0 0 14.6


229 19.1 October 0 0 0 14.6230 19.2 November 0 0 0 14.6231 19.3 December 0 0 0 14.6232 19.3 January 0 0 0 14.6233 19.4 February 0 0 0 14.6234 19.5 March 0 0 0 14.6235 19.6 April 0 0 0 14.6236 19.7 May 0 0 0 14.6237 19.8 June 0 0 0 14.6238 19.8 July 0 0 0 14.6239 19.9 August 0 0 0 14.6240 20 September 0 0 0 14.6

T-1

Thermal Cracking: Crack Depth Vs Time

0

0.5

1

1.5

2

2.5

3

3.5

4

0 24 48 72 96 120 144 168 192 216 240 264


Cra

ck D

epth

(in)

T-1

Thermal Cracking: Depth Ratio Vs Time

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1

0 24 48 72 96 120 144 168 192 216 240 264


Cav

e/ha

c

T-1

Thermal Cracking: Total Length Vs Time

0

200

400

600

800

1000

1200

1400

1600

1800

2000

0 24 48 72 96 120 144 168 192 216 240 264


Tota

l Len

gth

(ft/m

i)

Thermal Crack LengthCrack Length at ReliabilityDesign Limit

T-1

Transverse Crack Spacing

0.0

0.2

0.4

0.6

0.8

1.0

1.2

0 24 48 72 96 120 144 168 192 216 240 264


Cra

ck S

paci

ng (f

t)

T-14/14/2006 12:37 PM

1 of 1

Permanant Deformation: Rutting

0.00

0.10

0.20

0.30

0.40

0.50

0.60

0.70

0.80

0.90

1.00

0 24 48 72 96 120 144 168 192 216 240 264


Rut

ting

Dep

th (i

n)

SubTotalACSubTotalBaseSubTotalSGTotal RuttingTotalRutReliabilityTotal Rutting Design Limit

AC Rutting Design Value = 0.25Total Rutting Design Limit = 0.75

T-14/14/2006 12:37 PM

1 of 1

IRI

0

30

60

90

120

150

180

210

240

270

300

0 24 48 72 96 120 144 168 192 216 240 264


IRI (

in/m

i) IRIIRI at ReliabilityDesign Limit

Predicted Rutting: Project T-1

mo yr1 0.08 October 0.0254 0 0.0345 0 0.0225 0 0.0678 0 0.0254 0.0345 0.0903 0.1502 0 0.22652 0.17 November 0.0311 0 0.0377 0 0.0252 0 0.0789 0 0.0311 0.0377 0.1041 0.1729 0 0.25523 0.25 December 0.0346 0 0.0393 0 0.0268 0 0.0859 0 0.0346 0.0393 0.1127 0.1866 0 0.27254 0.33 January 0.0379 0 0.0406 0 0.028 0 0.0912 0 0.0379 0.0406 0.1191 0.1977 0 0.28635 0.42 February 0.0414 0 0.0419 0 0.029 0 0.0956 0 0.0414 0.0419 0.1246 0.208 0 0.29916 0.5 March 0.0468 0 0.0434 0 0.0301 0 0.0995 0 0.0468 0.0434 0.1296 0.2198 0 0.31377 0.58 April 0.0509 0 0.0445 0 0.0309 0 0.1028 0 0.0509 0.0445 0.1337 0.2292 0 0.32538 0.67 May 0.0571 0 0.0458 0 0.0318 0 0.1059 0 0.0571 0.0458 0.1377 0.2406 0 0.33939 0.75 June 0.0645 0 0.0472 0 0.0326 0 0.1088 0 0.0645 0.0472 0.1414 0.2531 0 0.354610 0.83 July 0.0731 0 0.0486 0 0.0334 0 0.1114 0 0.0731 0.0486 0.1448 0.2665 0 0.370911 0.92 August 0.0798 0 0.0496 0 0.0341 0 0.1138 0 0.0798 0.0496 0.1479 0.2773 0 0.38412 1 September 0.0839 0 0.0503 0 0.0346 0 0.1159 0 0.0839 0.0503 0.1505 0.2847 0 0.392913 1.08 October 0.0866 0 0.0508 0 0.035 0 0.1178 0 0.0866 0.0508 0.1528 0.2901 0 0.399414 1.17 November 0.0879 0 0.051 0 0.0353 0 0.1194 0 0.0879 0.051 0.1547 0.2936 0 0.403615 1.25 December 0.0888 0 0.0511 0 0.0355 0 0.1209 0 0.0888 0.0511 0.1564 0.2963 0 0.406916 1.33 January 0.0896 0 0.0512 0 0.0356 0 0.1223 0 0.0896 0.0512 0.1579 0.2987 0 0.409817 1.42 February 0.0904 0 0.0514 0 0.0358 0 0.1236 0 0.0904 0.0514 0.1594 0.3012 0 0.412718 1.5 March 0.0914 0 0.0515 0 0.036 0 0.1249 0 0.0914 0.0515 0.1609 0.3038 0 0.415919 1.58 April 0.0933 0 0.0518 0 0.0363 0 0.1262 0 0.0933 0.0518 0.1625 0.3076 0 0.420420 1.67 May 0.0971 0 0.0523 0 0.0366 0 0.1276 0 0.0971 0.0523 0.1642 0.3136 0 0.427621 1.75 June 0.1033 0 0.053 0 0.037 0 0.129 0 0.1033 0.053 0.166 0.3223 0 0.43822 1.83 July 0.1099 0 0.0537 0 0.0374 0 0.1304 0 0.1099 0.0537 0.1678 0.3313 0 0.448723 1.92 August 0.1149 0 0.0542 0 0.0377 0 0.1316 0 0.1149 0.0542 0.1693 0.3385 0 0.457224 2 September 0.1178 0 0.0546 0 0.038 0 0.1328 0 0.1178 0.0546 0.1708 0.3431 0 0.462725 2.08 October 0.1203 0 0.0549 0 0.0382 0 0.1339 0 0.1203 0.0549 0.1721 0.3472 0 0.467626 2.17 November 0.1216 0 0.055 0 0.0384 0 0.1349 0 0.1216 0.055 0.1733 0.3499 0 0.470727 2.25 December 0.1225 0 0.0551 0 0.0385 0 0.1358 0 0.1225 0.0551 0.1743 0.3519 0 0.473128 2.33 January 0.1231 0 0.0552 0 0.0386 0 0.1367 0 0.1231 0.0552 0.1753 0.3535 0 0.47529 2.42 February 0.1238 0 0.0553 0 0.0387 0 0.1375 0 0.1238 0.0553 0.1762 0.3553 0 0.477130 2.5 March 0.1247 0 0.0554 0 0.0389 0 0.1384 0 0.1247 0.0554 0.1772 0.3573 0 0.479531 2.58 April 0.1266 0 0.0556 0 0.039 0 0.1393 0 0.1266 0.0556 0.1783 0.3605 0 0.483332 2.67 May 0.129 0 0.0558 0 0.0392 0 0.1402 0 0.129 0.0558 0.1794 0.3643 0 0.487733 2.75 June 0.1315 0 0.0561 0 0.0394 0 0.1411 0 0.1315 0.0561 0.1805 0.3681 0 0.492234 2.83 July 0.135 0 0.0565 0 0.0396 0 0.142 0 0.135 0.0565 0.1816 0.3731 0 0.498135 2.92 August 0.1383 0 0.0568 0 0.0399 0 0.1428 0 0.1383 0.0568 0.1827 0.3778 0 0.503636 3 September 0.1408 0 0.057 0 0.0401 0 0.1437 0 0.1408 0.057 0.1838 0.3816 0 0.508137 3.08 October 0.1423 0 0.0572 0 0.0402 0 0.1444 0 0.1423 0.0572 0.1846 0.3841 0 0.51138 3.17 November 0.1431 0 0.0573 0 0.0403 0 0.1452 0 0.1431 0.0573 0.1855 0.3858 0 0.51339 3.25 December 0.1436 0 0.0573 0 0.0404 0 0.1458 0 0.1436 0.0573 0.1862 0.3871 0 0.514640 3.33 January 0.144 0 0.0573 0 0.0404 0 0.1464 0 0.144 0.0573 0.1868 0.3882 0 0.515841 3.42 February 0.1445 0 0.0574 0 0.0405 0 0.1471 0 0.1445 0.0574 0.1876 0.3895 0 0.517442 3.5 March 0.1455 0 0.0575 0 0.0406 0 0.1477 0 0.1455 0.0575 0.1883 0.3913 0 0.519543 3.58 April 0.1467 0 0.0576 0 0.0407 0 0.1484 0 0.1467 0.0576 0.1891 0.3934 0 0.521944 3.67 May 0.1488 0 0.0578 0 0.0409 0 0.1491 0 0.1488 0.0578 0.19 0.3967 0 0.525845 3.75 June 0.1513 0 0.058 0 0.041 0 0.1498 0 0.1513 0.058 0.1908 0.4002 0 0.529946 3.83 July 0.1539 0 0.0583 0 0.0412 0 0.1505 0 0.1539 0.0583 0.1917 0.4039 0 0.534247 3.92 August 0.1565 0 0.0585 0 0.0414 0 0.1512 0 0.1565 0.0585 0.1926 0.4076 0 0.538548 4 September 0.1588 0 0.0587 0 0.0415 0 0.1519 0 0.1588 0.0587 0.1934 0.4109 0 0.542449 4.08 October 0.1599 0 0.0588 0 0.0416 0 0.1525 0 0.1599 0.0588 0.1941 0.4128 0 0.544650 4.17 November 0.1606 0 0.0589 0 0.0417 0 0.153 0 0.1606 0.0589 0.1947 0.4142 0 0.546251 4.25 December 0.1609 0 0.0589 0 0.0418 0 0.1536 0 0.1609 0.0589 0.1954 0.4152 0 0.547452 4.33 January 0.1612 0 0.0589 0 0.0418 0 0.154 0 0.1612 0.0589 0.1958 0.4159 0 0.5482

Predicted Rutting: Project T-1Pavement

ageMonth

Maximum Rutting (inch)

AC1 Location (in) GB2 Location (in) SG3 Location (in) SG4 Location (in) SubTotalAC SubTotalBase SubTotalSG Total Location (in)TotalRutRelia

bility


53 4.42 February 0.1619 0 0.059 0 0.0419 0 0.1546 0 0.1619 0.059 0.1965 0.4173 0 0.549954 4.5 March 0.1626 0 0.059 0 0.042 0 0.1551 0 0.1626 0.059 0.1971 0.4187 0 0.551555 4.58 April 0.1638 0 0.0592 0 0.042 0 0.1557 0 0.1638 0.0592 0.1978 0.4207 0 0.553856 4.67 May 0.1653 0 0.0593 0 0.0422 0 0.1562 0 0.1653 0.0593 0.1984 0.423 0 0.556557 4.75 June 0.1678 0 0.0595 0 0.0423 0 0.1568 0 0.1678 0.0595 0.1991 0.4264 0 0.560558 4.83 July 0.17 0 0.0597 0 0.0424 0 0.1574 0 0.17 0.0597 0.1998 0.4295 0 0.564159 4.92 August 0.1726 0 0.0599 0 0.0426 0 0.158 0 0.1726 0.0599 0.2006 0.4331 0 0.568260 5 September 0.1758 0 0.0601 0 0.0427 0 0.1586 0 0.1758 0.0601 0.2013 0.4372 0 0.57361 5.08 October 0.1772 0 0.0603 0 0.0428 0 0.1591 0 0.1772 0.0603 0.2019 0.4394 0 0.575662 5.17 November 0.1779 0 0.0603 0 0.0429 0 0.1596 0 0.1779 0.0603 0.2025 0.4407 0 0.577163 5.25 December 0.1783 0 0.0604 0 0.0429 0 0.1601 0 0.1783 0.0604 0.203 0.4417 0 0.578264 5.33 January 0.1788 0 0.0604 0 0.043 0 0.1605 0 0.1788 0.0604 0.2035 0.4427 0 0.579465 5.42 February 0.1795 0 0.0604 0 0.0431 0 0.161 0 0.1795 0.0604 0.2041 0.4439 0 0.580866 5.5 March 0.1806 0 0.0605 0 0.0432 0 0.1615 0 0.1806 0.0605 0.2047 0.4458 0 0.58367 5.58 April 0.1815 0 0.0606 0 0.0432 0 0.1619 0 0.1815 0.0606 0.2051 0.4473 0 0.584768 5.67 May 0.1831 0 0.0607 0 0.0433 0 0.1624 0 0.1831 0.0607 0.2057 0.4496 0 0.587469 5.75 June 0.1853 0 0.0609 0 0.0435 0 0.163 0 0.1853 0.0609 0.2065 0.4526 0 0.590970 5.83 July 0.1882 0 0.0611 0 0.0436 0 0.1635 0 0.1882 0.0611 0.2071 0.4564 0 0.595371 5.92 August 0.1906 0 0.0613 0 0.0437 0 0.164 0 0.1906 0.0613 0.2077 0.4596 0 0.59972 6 September 0.1923 0 0.0614 0 0.0438 0 0.1645 0 0.1923 0.0614 0.2083 0.462 0 0.601773 6.08 October 0.1934 0 0.0615 0 0.0439 0 0.1649 0 0.1934 0.0615 0.2088 0.4637 0 0.603774 6.17 November 0.1939 0 0.0616 0 0.0439 0 0.1653 0 0.1939 0.0616 0.2092 0.4647 0 0.604975 6.25 December 0.1942 0 0.0616 0 0.044 0 0.1657 0 0.1942 0.0616 0.2097 0.4655 0 0.605876 6.33 January 0.1945 0 0.0616 0 0.044 0 0.1661 0 0.1945 0.0616 0.2101 0.4662 0 0.606677 6.42 February 0.1948 0 0.0616 0 0.0441 0 0.1665 0 0.1948 0.0616 0.2106 0.467 0 0.607578 6.5 March 0.1952 0 0.0617 0 0.0441 0 0.1669 0 0.1952 0.0617 0.211 0.4679 0 0.608679 6.58 April 0.1961 0 0.0617 0 0.0442 0 0.1673 0 0.1961 0.0617 0.2115 0.4693 0 0.610280 6.67 May 0.198 0 0.0619 0 0.0443 0 0.1678 0 0.198 0.0619 0.2121 0.4719 0 0.613281 6.75 June 0.201 0 0.0621 0 0.0444 0 0.1682 0 0.201 0.0621 0.2126 0.4757 0 0.617682 6.83 July 0.2044 0 0.0623 0 0.0445 0 0.1687 0 0.2044 0.0623 0.2132 0.4799 0 0.622483 6.92 August 0.2072 0 0.0625 0 0.0446 0 0.1692 0 0.2072 0.0625 0.2138 0.4835 0 0.626584 7 September 0.2088 0 0.0626 0 0.0447 0 0.1696 0 0.2088 0.0626 0.2143 0.4858 0 0.629285 7.08 October 0.2101 0 0.0627 0 0.0448 0 0.17 0 0.2101 0.0627 0.2148 0.4877 0 0.631486 7.17 November 0.2109 0 0.0628 0 0.0449 0 0.1704 0 0.2109 0.0628 0.2153 0.4889 0 0.632887 7.25 December 0.2114 0 0.0628 0 0.0449 0 0.1708 0 0.2114 0.0628 0.2157 0.4898 0 0.633888 7.33 January 0.2117 0 0.0628 0 0.045 0 0.1711 0 0.2117 0.0628 0.2161 0.4906 0 0.634789 7.42 February 0.2121 0 0.0628 0 0.045 0 0.1715 0 0.2121 0.0628 0.2165 0.4914 0 0.635690 7.5 March 0.2126 0 0.0629 0 0.045 0 0.1718 0 0.2126 0.0629 0.2168 0.4923 0 0.636791 7.58 April 0.2138 0 0.063 0 0.0451 0 0.1722 0 0.2138 0.063 0.2173 0.4942 0 0.638892 7.67 May 0.2153 0 0.0631 0 0.0452 0 0.1726 0 0.2153 0.0631 0.2178 0.4962 0 0.641293 7.75 June 0.2168 0 0.0632 0 0.0453 0 0.173 0 0.2168 0.0632 0.2183 0.4983 0 0.643694 7.83 July 0.2191 0 0.0633 0 0.0454 0 0.1735 0 0.2191 0.0633 0.2189 0.5013 0 0.64795 7.92 August 0.2214 0 0.0635 0 0.0455 0 0.1739 0 0.2214 0.0635 0.2194 0.5042 0 0.650496 8 September 0.223 0 0.0636 0 0.0456 0 0.1743 0 0.223 0.0636 0.2199 0.5064 0 0.652997 8.08 October 0.224 0 0.0637 0 0.0456 0 0.1746 0 0.224 0.0637 0.2202 0.5079 0 0.654698 8.17 November 0.2245 0 0.0637 0 0.0457 0 0.175 0 0.2245 0.0637 0.2207 0.5088 0 0.655699 8.25 December 0.2248 0 0.0637 0 0.0457 0 0.1753 0 0.2248 0.0637 0.221 0.5095 0 0.6564100 8.33 January 0.225 0 0.0637 0 0.0457 0 0.1756 0 0.225 0.0637 0.2213 0.5101 0 0.6571101 8.42 February 0.2253 0 0.0637 0 0.0458 0 0.1759 0 0.2253 0.0637 0.2217 0.5108 0 0.6579102 8.5 March 0.226 0 0.0638 0 0.0458 0 0.1763 0 0.226 0.0638 0.2221 0.5119 0 0.6592103 8.58 April 0.2268 0 0.0638 0 0.0459 0 0.1766 0 0.2268 0.0638 0.2225 0.5131 0 0.6606104 8.67 May 0.2283 0 0.0639 0 0.0459 0 0.177 0 0.2283 0.0639 0.2229 0.5151 0 0.6629105 8.75 June 0.2299 0 0.064 0 0.046 0 0.1774 0 0.2299 0.064 0.2234 0.5174 0 0.6655106 8.83 July 0.2319 0 0.0642 0 0.0461 0 0.1777 0 0.2319 0.0642 0.2238 0.5199 0 0.6684107 8.92 August 0.2338 0 0.0643 0 0.0462 0 0.1781 0 0.2338 0.0643 0.2243 0.5224 0 0.6712108 9 September 0.2355 0 0.0644 0 0.0463 0 0.1785 0 0.2355 0.0644 0.2248 0.5247 0 0.6738109 9.08 October 0.2364 0 0.0645 0 0.0463 0 0.1788 0 0.2364 0.0645 0.2251 0.526 0 0.6753


110 9.17 November 0.2368 0 0.0645 0 0.0464 0 0.1791 0 0.2368 0.0645 0.2255 0.5268 0 0.6763111 9.25 December 0.2371 0 0.0645 0 0.0464 0 0.1794 0 0.2371 0.0645 0.2258 0.5274 0 0.6769112 9.33 January 0.2372 0 0.0645 0 0.0464 0 0.1797 0 0.2372 0.0645 0.2261 0.5278 0 0.6774113 9.42 February 0.2377 0 0.0645 0 0.0465 0 0.18 0 0.2377 0.0645 0.2265 0.5287 0 0.6784114 9.5 March 0.2383 0 0.0646 0 0.0465 0 0.1803 0 0.2383 0.0646 0.2268 0.5297 0 0.6796115 9.58 April 0.2391 0 0.0646 0 0.0466 0 0.1806 0 0.2391 0.0646 0.2272 0.531 0 0.6811116 9.67 May 0.2402 0 0.0647 0 0.0466 0 0.181 0 0.2402 0.0647 0.2276 0.5325 0 0.6828117 9.75 June 0.2422 0 0.0648 0 0.0467 0 0.1813 0 0.2422 0.0648 0.228 0.535 0 0.6856118 9.83 July 0.2439 0 0.0649 0 0.0468 0 0.1817 0 0.2439 0.0649 0.2285 0.5373 0 0.6883119 9.92 August 0.246 0 0.0651 0 0.0469 0 0.182 0 0.246 0.0651 0.2289 0.54 0 0.6913120 10 September 0.2484 0 0.0652 0 0.047 0 0.1824 0 0.2484 0.0652 0.2294 0.543 0 0.6948121 10.08 October 0.2495 0 0.0653 0 0.047 0 0.1827 0 0.2495 0.0653 0.2297 0.5445 0 0.6965122 10.17 November 0.25 0 0.0653 0 0.0471 0 0.183 0 0.25 0.0653 0.2301 0.5454 0 0.6975123 10.25 December 0.2504 0 0.0653 0 0.0471 0 0.1833 0 0.2504 0.0653 0.2304 0.5461 0 0.6983124 10.33 January 0.2508 0 0.0654 0 0.0471 0 0.1836 0 0.2508 0.0654 0.2307 0.5468 0 0.6991125 10.42 February 0.2513 0 0.0654 0 0.0472 0 0.1838 0 0.2513 0.0654 0.231 0.5476 0 0.7126 10.5 March 0.2522 0 0.0654 0 0.0472 0 0.1842 0 0.2522 0.0654 0.2314 0.549 0 0.7016127 10.58 April 0.2529 0 0.0655 0 0.0473 0 0.1845 0 0.2529 0.0655 0.2318 0.5501 0 0.7029128 10.67 May 0.2541 0 0.0656 0 0.0473 0 0.1848 0 0.2541 0.0656 0.2321 0.5518 0 0.7048129 10.75 June 0.256 0 0.0657 0 0.0474 0 0.1851 0 0.256 0.0657 0.2325 0.5541 0 0.7075130 10.83 July 0.2584 0 0.0658 0 0.0475 0 0.1854 0 0.2584 0.0658 0.2329 0.5571 0 0.7109131 10.92 August 0.2604 0 0.0659 0 0.0476 0 0.1858 0 0.2604 0.0659 0.2334 0.5596 0 0.7137132 11 September 0.2618 0 0.066 0 0.0476 0 0.1861 0 0.2618 0.066 0.2337 0.5615 0 0.7159133 11.08 October 0.2627 0 0.0661 0 0.0477 0 0.1864 0 0.2627 0.0661 0.2341 0.5628 0 0.7174134 11.17 November 0.2631 0 0.0661 0 0.0477 0 0.1867 0 0.2631 0.0661 0.2344 0.5635 0 0.7182135 11.25 December 0.2633 0 0.0661 0 0.0477 0 0.1869 0 0.2633 0.0661 0.2346 0.5641 0 0.7188136 11.33 January 0.2636 0 0.0661 0 0.0478 0 0.1872 0 0.2636 0.0661 0.235 0.5646 0 0.7194137 11.42 February 0.2638 0 0.0661 0 0.0478 0 0.1874 0 0.2638 0.0661 0.2352 0.5652 0 0.7201138 11.5 March 0.2641 0 0.0662 0 0.0478 0 0.1877 0 0.2641 0.0662 0.2355 0.5658 0 0.7208139 11.58 April 0.2649 0 0.0662 0 0.0479 0 0.188 0 0.2649 0.0662 0.2359 0.5669 0 0.722140 11.67 May 0.2664 0 0.0663 0 0.0479 0 0.1883 0 0.2664 0.0663 0.2362 0.5689 0 0.7243141 11.75 June 0.269 0 0.0664 0 0.048 0 0.1886 0 0.269 0.0664 0.2366 0.5721 0 0.7279142 11.83 July 0.2719 0 0.0666 0 0.0481 0 0.1889 0 0.2719 0.0666 0.237 0.5755 0 0.7318143 11.92 August 0.2742 0 0.0667 0 0.0482 0 0.1893 0 0.2742 0.0667 0.2375 0.5784 0 0.7351144 12 September 0.2757 0 0.0668 0 0.0482 0 0.1896 0 0.2757 0.0668 0.2378 0.5803 0 0.7373145 12.08 October 0.2769 0 0.0669 0 0.0483 0 0.1899 0 0.2769 0.0669 0.2382 0.5819 0 0.7391146 12.17 November 0.2775 0 0.0669 0 0.0483 0 0.1901 0 0.2775 0.0669 0.2384 0.5829 0 0.7402147 12.25 December 0.2779 0 0.0669 0 0.0484 0 0.1904 0 0.2779 0.0669 0.2388 0.5836 0 0.741148 12.33 January 0.2782 0 0.0669 0 0.0484 0 0.1906 0 0.2782 0.0669 0.239 0.5841 0 0.7416149 12.42 February 0.2785 0 0.067 0 0.0484 0 0.1909 0 0.2785 0.067 0.2393 0.5847 0 0.7423150 12.5 March 0.2789 0 0.067 0 0.0485 0 0.1911 0 0.2789 0.067 0.2395 0.5855 0 0.7432151 12.58 April 0.28 0 0.067 0 0.0485 0 0.1914 0 0.28 0.067 0.2399 0.5869 0 0.7448152 12.67 May 0.2812 0 0.0671 0 0.0486 0 0.1917 0 0.2812 0.0671 0.2403 0.5886 0 0.7467153 12.75 June 0.2825 0 0.0672 0 0.0486 0 0.192 0 0.2825 0.0672 0.2406 0.5904 0 0.7487154 12.83 July 0.2846 0 0.0673 0 0.0487 0 0.1923 0 0.2846 0.0673 0.241 0.5929 0 0.7516155 12.92 August 0.2865 0 0.0674 0 0.0488 0 0.1926 0 0.2865 0.0674 0.2414 0.5953 0 0.7543156 13 September 0.288 0 0.0675 0 0.0488 0 0.1929 0 0.288 0.0675 0.2417 0.5972 0 0.7564157 13.08 October 0.2889 0 0.0675 0 0.0489 0 0.1932 0 0.2889 0.0675 0.2421 0.5984 0 0.7578158 13.17 November 0.2893 0 0.0676 0 0.0489 0 0.1934 0 0.2893 0.0676 0.2423 0.5992 0 0.7587159 13.25 December 0.2896 0 0.0676 0 0.0489 0 0.1936 0 0.2896 0.0676 0.2425 0.5997 0 0.7593160 13.33 January 0.2898 0 0.0676 0 0.0489 0 0.1939 0 0.2898 0.0676 0.2428 0.6002 0 0.7598161 13.42 February 0.2901 0 0.0676 0 0.049 0 0.1941 0 0.2901 0.0676 0.2431 0.6007 0 0.7604162 13.5 March 0.2906 0 0.0676 0 0.049 0 0.1944 0 0.2906 0.0676 0.2434 0.6016 0 0.7614163 13.58 April 0.2913 0 0.0677 0 0.049 0 0.1946 0 0.2913 0.0677 0.2436 0.6026 0 0.7626164 13.67 May 0.2926 0 0.0677 0 0.0491 0 0.1949 0 0.2926 0.0677 0.244 0.6043 0 0.7645165 13.75 June 0.2942 0 0.0678 0 0.0491 0 0.1952 0 0.2942 0.0678 0.2444 0.6063 0 0.7668166 13.83 July 0.2959 0 0.0679 0 0.0492 0 0.1954 0 0.2959 0.0679 0.2446 0.6085 0 0.7692


167 13.92 August 0.2977 0 0.068 0 0.0493 0 0.1957 0 0.2977 0.068 0.245 0.6107 0 0.7717168 14 September 0.2992 0 0.0681 0 0.0493 0 0.196 0 0.2992 0.0681 0.2453 0.6126 0 0.7739169 14.08 October 0.3 0 0.0681 0 0.0494 0 0.1963 0 0.3 0.0681 0.2457 0.6137 0 0.7752170 14.17 November 0.3004 0 0.0682 0 0.0494 0 0.1965 0 0.3004 0.0682 0.2459 0.6144 0 0.7759171 14.25 December 0.3006 0 0.0682 0 0.0494 0 0.1967 0 0.3006 0.0682 0.2461 0.6149 0 0.7765172 14.33 January 0.3007 0 0.0682 0 0.0494 0 0.1969 0 0.3007 0.0682 0.2463 0.6152 0 0.7768173 14.42 February 0.3012 0 0.0682 0 0.0495 0 0.1972 0 0.3012 0.0682 0.2467 0.616 0 0.7778174 14.5 March 0.3016 0 0.0682 0 0.0495 0 0.1974 0 0.3016 0.0682 0.2469 0.6167 0 0.7785175 14.58 April 0.3024 0 0.0683 0 0.0495 0 0.1976 0 0.3024 0.0683 0.2471 0.6179 0 0.7799176 14.67 May 0.3034 0 0.0683 0 0.0496 0 0.1979 0 0.3034 0.0683 0.2475 0.6192 0 0.7814177 14.75 June 0.3052 0 0.0684 0 0.0497 0 0.1982 0 0.3052 0.0684 0.2479 0.6214 0 0.7839178 14.83 July 0.3068 0 0.0685 0 0.0497 0 0.1984 0 0.3068 0.0685 0.2481 0.6234 0 0.7861179 14.92 August 0.3087 0 0.0686 0 0.0498 0 0.1987 0 0.3087 0.0686 0.2485 0.6258 0 0.7888180 15 September 0.3109 0 0.0687 0 0.0498 0 0.199 0 0.3109 0.0687 0.2489 0.6285 0 0.7919181 15.08 October 0.3119 0 0.0688 0 0.0499 0 0.1993 0 0.3119 0.0688 0.2492 0.6298 0 0.7934182 15.17 November 0.3124 0 0.0688 0 0.0499 0 0.1995 0 0.3124 0.0688 0.2494 0.6306 0 0.7942183 15.25 December 0.3127 0 0.0688 0 0.05 0 0.1997 0 0.3127 0.0688 0.2496 0.6311 0 0.7948184 15.33 January 0.313 0 0.0688 0 0.05 0 0.1999 0 0.313 0.0688 0.2499 0.6317 0 0.7955185 15.42 February 0.3135 0 0.0688 0 0.05 0 0.2002 0 0.3135 0.0688 0.2502 0.6325 0 0.7964186 15.5 March 0.3143 0 0.0689 0 0.05 0 0.2004 0 0.3143 0.0689 0.2504 0.6336 0 0.7976187 15.58 April 0.315 0 0.0689 0 0.0501 0 0.2006 0 0.315 0.0689 0.2507 0.6346 0 0.7988188 15.67 May 0.3161 0 0.069 0 0.0501 0 0.2009 0 0.3161 0.069 0.251 0.6361 0 0.8005189 15.75 June 0.3178 0 0.0691 0 0.0502 0 0.2011 0 0.3178 0.0691 0.2513 0.6382 0 0.8028190 15.83 July 0.3201 0 0.0692 0 0.0503 0 0.2014 0 0.3201 0.0692 0.2516 0.6409 0 0.8059191 15.92 August 0.3219 0 0.0693 0 0.0503 0 0.2017 0 0.3219 0.0693 0.252 0.6432 0 0.8085192 16 September 0.3233 0 0.0693 0 0.0504 0 0.2019 0 0.3233 0.0693 0.2523 0.6449 0 0.8104193 16.08 October 0.3241 0 0.0694 0 0.0504 0 0.2022 0 0.3241 0.0694 0.2526 0.6461 0 0.8117194 16.17 November 0.3245 0 0.0694 0 0.0504 0 0.2024 0 0.3245 0.0694 0.2528 0.6467 0 0.8124195 16.25 December 0.3247 0 0.0694 0 0.0505 0 0.2026 0 0.3247 0.0694 0.2531 0.6472 0 0.813196 16.33 January 0.3249 0 0.0694 0 0.0505 0 0.2028 0 0.3249 0.0694 0.2533 0.6476 0 0.8134197 16.42 February 0.3252 0 0.0694 0 0.0505 0 0.203 0 0.3252 0.0694 0.2535 0.6481 0 0.814198 16.5 March 0.3255 0 0.0694 0 0.0505 0 0.2032 0 0.3255 0.0694 0.2537 0.6486 0 0.8146199 16.58 April 0.3262 0 0.0695 0 0.0505 0 0.2034 0 0.3262 0.0695 0.2539 0.6496 0 0.8157200 16.67 May 0.3276 0 0.0695 0 0.0506 0 0.2037 0 0.3276 0.0695 0.2543 0.6515 0 0.8178201 16.75 June 0.3301 0 0.0697 0 0.0507 0 0.204 0 0.3301 0.0697 0.2547 0.6544 0 0.8211202 16.83 July 0.3328 0 0.0698 0 0.0507 0 0.2042 0 0.3328 0.0698 0.2549 0.6576 0 0.8247203 16.92 August 0.335 0 0.0699 0 0.0508 0 0.2045 0 0.335 0.0699 0.2553 0.6602 0 0.8276204 17 September 0.3364 0 0.0699 0 0.0508 0 0.2047 0 0.3364 0.0699 0.2556 0.6619 0 0.8296205 17.08 October 0.3375 0 0.07 0 0.0509 0 0.205 0 0.3375 0.07 0.2559 0.6634 0 0.8312206 17.17 November 0.3381 0 0.07 0 0.0509 0 0.2052 0 0.3381 0.07 0.2561 0.6643 0 0.8322207 17.25 December 0.3385 0 0.0701 0 0.051 0 0.2054 0 0.3385 0.0701 0.2564 0.6649 0 0.8329208 17.33 January 0.3388 0 0.0701 0 0.051 0 0.2056 0 0.3388 0.0701 0.2566 0.6654 0 0.8335209 17.42 February 0.3391 0 0.0701 0 0.051 0 0.2058 0 0.3391 0.0701 0.2568 0.6659 0 0.8341210 17.5 March 0.3394 0 0.0701 0 0.051 0 0.206 0 0.3394 0.0701 0.257 0.6666 0 0.8348211 17.58 April 0.3405 0 0.0701 0 0.0511 0 0.2063 0 0.3405 0.0701 0.2574 0.6679 0 0.8363212 17.67 May 0.3416 0 0.0702 0 0.0511 0 0.2065 0 0.3416 0.0702 0.2576 0.6694 0 0.838213 17.75 June 0.3429 0 0.0703 0 0.0512 0 0.2067 0 0.3429 0.0703 0.2579 0.6711 0 0.8399214 17.83 July 0.3449 0 0.0704 0 0.0512 0 0.207 0 0.3449 0.0704 0.2582 0.6734 0 0.8425215 17.92 August 0.3467 0 0.0704 0 0.0513 0 0.2072 0 0.3467 0.0704 0.2585 0.6757 0 0.8451216 18 September 0.3482 0 0.0705 0 0.0513 0 0.2075 0 0.3482 0.0705 0.2588 0.6775 0 0.8471217 18.08 October 0.349 0 0.0706 0 0.0514 0 0.2077 0 0.349 0.0706 0.2591 0.6787 0 0.8485218 18.17 November 0.3494 0 0.0706 0 0.0514 0 0.2079 0 0.3494 0.0706 0.2593 0.6793 0 0.8491219 18.25 December 0.3497 0 0.0706 0 0.0514 0 0.2081 0 0.3497 0.0706 0.2595 0.6798 0 0.8497220 18.33 January 0.3499 0 0.0706 0 0.0514 0 0.2083 0 0.3499 0.0706 0.2597 0.6802 0 0.8501221 18.42 February 0.3501 0 0.0706 0 0.0514 0 0.2085 0 0.3501 0.0706 0.2599 0.6807 0 0.8507222 18.5 March 0.3507 0 0.0706 0 0.0515 0 0.2087 0 0.3507 0.0706 0.2602 0.6815 0 0.8516223 18.58 April 0.3513 0 0.0707 0 0.0515 0 0.2089 0 0.3513 0.0707 0.2604 0.6824 0 0.8526


224 18.67 May 0.3526 0 0.0707 0 0.0515 0 0.2091 0 0.3526 0.0707 0.2606 0.684 0 0.8544225 18.75 June 0.3541 0 0.0708 0 0.0516 0 0.2094 0 0.3541 0.0708 0.261 0.6859 0 0.8566226 18.83 July 0.3558 0 0.0709 0 0.0517 0 0.2096 0 0.3558 0.0709 0.2612 0.688 0 0.8589227 18.92 August 0.3575 0 0.0709 0 0.0517 0 0.2099 0 0.3575 0.0709 0.2616 0.69 0 0.8612228 19 September 0.359 0 0.071 0 0.0518 0 0.2101 0 0.359 0.071 0.2619 0.6919 0 0.8633229 19.08 October 0.3597 0 0.071 0 0.0518 0 0.2103 0 0.3597 0.071 0.2621 0.6929 0 0.8644230 19.17 November 0.3601 0 0.0711 0 0.0518 0 0.2105 0 0.3601 0.0711 0.2623 0.6935 0 0.8651231 19.25 December 0.3603 0 0.0711 0 0.0518 0 0.2107 0 0.3603 0.0711 0.2625 0.6939 0 0.8655232 19.33 January 0.3605 0 0.0711 0 0.0518 0 0.2109 0 0.3605 0.0711 0.2627 0.6942 0 0.8659233 19.42 February 0.3609 0 0.0711 0 0.0519 0 0.2111 0 0.3609 0.0711 0.263 0.6949 0 0.8667234 19.5 March 0.3613 0 0.0711 0 0.0519 0 0.2113 0 0.3613 0.0711 0.2632 0.6956 0 0.8675235 19.58 April 0.3621 0 0.0711 0 0.0519 0 0.2115 0 0.3621 0.0711 0.2634 0.6967 0 0.8687236 19.67 May 0.3631 0 0.0712 0 0.052 0 0.2117 0 0.3631 0.0712 0.2637 0.6979 0 0.87237 19.75 June 0.3648 0 0.0713 0 0.052 0 0.2119 0 0.3648 0.0713 0.2639 0.7001 0 0.8725238 19.83 July 0.3664 0 0.0713 0 0.0521 0 0.2122 0 0.3664 0.0713 0.2643 0.7019 0 0.8745239 19.92 August 0.3683 0 0.0714 0 0.0521 0 0.2124 0 0.3683 0.0714 0.2645 0.7043 0 0.8772240 20 September 0.3704 0 0.0715 0 0.0522 0 0.2126 0 0.3704 0.0715 0.2648 0.7068 0 0.88

210

LIST OF REFERENCES

1. Yuang H . Huang, Pavement Analysis and Design, 1993 Prentice-Hall Inc. New Jersey 2. ERES. 2002 Design Guide, Design of New and Rehabilitated Pavement Structures, Draft

Final Report. National Cooperative Highway Research Program. Washington D.C., 2002

3. Ayres, M and Witczak, M.(1998) “AYMA - A Mechanistic Probabilistic System to Evaluate Flexible Pavement Performance”, Transportation Research Board, 77th Annual Meeting Paper No. 980738, Washington D.C.

4. Leahy, R. B., Permanent Deformation Characteristics of Asphalt Pavement, Ph.D.

Dissertation University of Maryland, College Park, 1989.

5. Kaloush K.E. and Witczak M. W. (2000) “Development of a Permanent to Elastic Strain Ratio Model for Asphalt Mixtures”. Development of the 2002 Guide for the Design of New and Rehabilitated Pavement Structures. NCHRP 1-37A. Inter Team Technical Report. Sept. 2000.

6. Tseng, K and Lytton, R (1989) Prediction of Permanent Deformation in Flexible

Pavement Materials. Implication of the Aggregates in the Design, Construction and Performance of Flexible Pavements, ASTM STP 1016, ASTM, pp. 154-172.

7. Masad, S, Sensitivity Analysis of Flexible Pavement Response and AASHTO 2002 Design

Guide for Properties of Unbound Layers, M.S., Thesis Texas A & M University, 2004.

Documents

Sensitivity Analysis Of Aashto's 2002 Flexible And Rigid