Development and Implementation of the Reflective …onlinepubs.trb.org/onlinepubs/webinars/160817.pdf · Development and Implementation of the Reflective Cracking Model in the Mechanistic-Empirical

Development and Implementation of the Reflective Cracking Model in the Mechanistic-Empirical Pavement Design Guide Organizer: TRB Standing Committee on Pavement Rehabilitation August 17, 2016

Today’s Presenters • Moderator

Mostafa Elseifi, Louisiana State University

• Development of the Reflection Cracking Model in the Mechanistic-Empirical Pavement Design Guide Robert L. Lytton, Texas A&M University

• Reflection Cracking Integration into Pavement ME Design Harold L. Von Quintus, ARA/TRANS

• Questions & Answers

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Today’s First Presenter

• Development of the Reflection Cracking Model in the Mechanistic-Empirical Pavement Design Guide Robert L. Lytton, Texas A&M University

Development of the Reflection Cracking Model in the Mechanistic-Empirical Pavement Design Guide

Robert L. Lytton

Webinar August 17, 2016

National Cooperative Highway Research Program

1

2

Traffic Material Properties

Climate EICM

Pavement Structure

Pavement Response (σ, ε) Model: Multi-layer

elastic system

Pavement Distress Models

Pavement Performance Predictions

INPUT

OUTPUT

MODELS

Interlayer

Existing Pavement Conditions

Pavement Response Model Stress Intensity Factor (SIF)

Artificial Neural Network (ANN)

Pavement Distress Model Reflection Cracking

(Thermal, Shearing, Bending)

Pavement Performance Prediction: Reflection Cracking

Extent and Severity

MEPDG Model Reflection Cracking Model

Flow Chart in Overall

3

Selected Test Sections • 10 models

Field Data Collection • Distress • Traffic • Pavement • Weather

Field Data Analysis • Distress • Traffic • Axle load distribution

Temperature Model • Weather data • Modeling temperature with

depth • New temperature model

Crack Propagation Model • Temperature

• Traffic shear

• Traffic bending

• Artificial neural network models Modulus Stress intensity factors

• Viscoelastic thermal stress • Crack growth

Calibration Process • Asphalt modulus

Falling weight deflectometer

Artificial neural network • Calculated number of days

Thermal (2) Shear (2) Bending (1)

• Calibration to field distress Five calibration

coefficients Three levels of damage

Mechanisms of Reflection Cracking

4

Thermal crack growth

Traffic crack growth

Thermal expansion and contraction

Traffic movement

Bituminous surfacing

Lean concrete roadbase

Sub-base

Bending Stress Shearing Stress Thermal Stress

Overlay

Position I NfB1 NfS1

NfS2

NfT1

NfT1

C

Bending Stress

Shearing Stress

Stre

sses

at T

ip o

f Cra

ck

Overlay

Old Concrete Layer

Base Course

Tip of Crack

5

6

WF

DF

WNF

DNF

Field Data Collection – LTPP Test Sections

Field Data Collection - Test Sections

7

Category (Overlay/ Exist. Layer) Total Test Sections

No. of Test Sections

WF DF WNF DNF

AC/AC 108 59 16 33

AC/Mill/AC 125 62 47 16

AC/CRC 21 21

AC/JRC(JPC) 69 69

AC/SC(FC) 38 26 12

AC/Reinforcing/AC 11 11

AC/Reinforcing/JPC 31 24 7

Total 403 261 27 99 16

• Section 340503 (WF zone in New Jersey) – AC/AC overlay rehabilitation: July 27th, 1992 – Transverse crack length before overlay: 88.2m

Data Collected from LTPP Sections

8

0

10

20

30

40

50

60

7/27/9

2

12/9/

93

4/23/9

59/4

/96

1/17/9

86/1

/99

10/13

/00

2/25/0

2

7/10/0

3

11/21

/04

Observation Date

Ref

lect

ive

Cra

ck L

engt

h (m

)

0.00.10.20.30.40.50.60.70.80.91.0

0 1000 2000 3000 4000 5000

No. of Days after Overlay

Cra

ck L

engt

h (ra

tio)

Observed crack length Ratio of reflection crack length to max. length

• The amount and severity of reflection cracking follows a sigmoidal curve (S-shape)

Development of Reflection Cracking

9

0

1020

3040

5060

7080

90

0 200 400 600 800 1000 1200 1400 1600

Traffic or Time

AR

EA (%

)

High Severity

High+Medium Severity

High+Medium+Low Severity

• Factors in reflection cracking model

– Scale factor ρ : how wide the rising portion of curve is – Shape factor β : how steep the rising portion of curve is

Reflection Cracking Model

10

100 TotalDRFAS e

βρ

− = ⋅

β < 1.0

β > 1.0

Crack Length

Traffic or Time

Crack Length

Traffic or Time

t =ρ1 t =ρ2 t =ρ3

e-1 = 36.8%

β = 1.0

• LTPP section 340503 (WF zone in New Jersey) – AC/AC overlay

Calibrated Models for LTPP Sections

11

0.00.10.20.30.40.50.60.70.80.91.0

0 1000 2000 3000 4000 5000

No. of Days after Overlays

Ref

lect

ive

Cra

ck L

engt

h (r

atio

)

Severity Parameter

β ρ

H+M+L 2.365 3617.12

H+M 4.107 4761.25

H N/A N/A

Calibrated Parameters Values measured predicted H+M+L H+M H

Mechanisms of Reflection Cracking

12

Thermal crack growth

Traffic crack growth

Thermal expansion and contraction

Traffic movement

Bituminous surfacing

Lean concrete roadbase

Sub-base

Bending Stress Shearing Stress Thermal Stress

Overlay

Position I NfB1 NfS1

NfS2

NfT1

NfT1

C

Rectangular Tire Patch Length

Tire LoadTire Length Tire Pressure Tire Width

=×

Tire Length

Width

Uniform Pressure

13

Eight Categories on Axle Type and Number of Tires

14

Vehicle Class Single Axle Tandem Axle Tridem Axle Quad. Axle

4

No. 1 No. 3 No. 5 No. 7

5 6

No. 4 No. 6 No. 8

7 8

No. 2

9 10 11 12 13 14

Dual Tires

Single Tires

Example: Category 1 of LTPP Section 180901 in 2004

15

0.00

0.20

0.40

0.60

0.80

1.00

0 3 6 9 12 15 18 21

Tire Length (in.)

Cu

mu

lati

ve A

xle

Lo

ad D

istr

ibu

tio

n Measured

Model

L 2

P 2

L 1

P 1

• Model developed by Dr. Charles Glover’s research group, Department of Chemical Engineering, Texas A&M.

Pavement Temperature Model

16

(Model source: Xin Jin, Rongbin Han, and Dr. Charles Glover, Department of Chemical Engineering, Texas A&M University)

α : Albedo Ta: Air temperature qs: Solar radiation ε : emissivity coefficient εa : absorption coefficient

к: Thermal conductivity

Solar radiation Atmospheric downwelling

longwave radiaiton

Outgoing longwave radiation

Heat convection by wind

Pavement Heat conduction

Albedo Distribution in Winter

17

0.15-0.2 0.3-0.35

0 2 4 6 8 10 12 14 16 18 20 22 24 26

-8

-6

-4

-2

0

2

4

6

8Te

mpe

ratu

re F

lutua

tion

Patte

rn A

roun

d Da

ily A

vera

ge T

empe

ratu

re (D

egre

e C)

Hours

Texas (48-1000) Texas (48-0800) Texas (48-A800) South Dakota (46-0800) Utah (49-0800) Nevada (32-0100)

18

Pavement Structural Cases

19

Modeling of Stress Intensity Factor (SIF) by Artificial Neural Network (ANN) (1/2)

20

AC_AC AC_PCC

Modeling of Stress Intensity Factor (SIF) by Artificial Neural Network (ANN) (2/2)

21

Pure_Bending_AC_AC_Single_Tire_Together Pure_Bending_AC_AC_Single_Tire_Together (Only Positive)

• Witczak 2006 Model

Modeling of Relaxation Modulus by Artificial Neural Network (ANN) (2006 Model)

22

Input Output

R2 Gradation Volumetric Binder Data Witczak ANN

3/4 (%)

3/8 (%)

#4 (%)

#200 (%)

Va

(%) Vbeff

(%) Log|G*| 106 psi

δc

deg E* psi 0.77 0.96

0

10

20

30

40

50

60

0 10 20 30 40 50 60

Pre

dict

ed IE

*I (G

Pa)

Observed IE*I (GPa)

Witczak 2006 ANN 2006

Crack Growth Model - Paris’ Law

23

( )

10

32 1 4

0

log log log

( )

nk

mix

tmix

t nk

dc A K adN

gn gm

gA g D gm

a w t dt

σ

∆

= ⋅ ∆ ⋅

= +

= + +

= ∫D1 = creep compliance coefficient σt = tensile strength mmix = slope of complex moduli versus loading times g0 ~ g6 = coefficients varying with climate zones ak = the viscoelastic stress pulse effect

Loading Time

E(t,T)

mmix

11.95

11.56

( , ) 10000.005 / , 77 , 6.8956.895 21.3

( , ) 10000.5 / , 77 , 6.8956.895 45.5

t

t

E t Tr in mm T F Temperature

E t Tr in mm T F Traffic

σ

σ

× = = = − > ×

× = = = − > ×

24

Crack Growth Model - Paris’ Law

Coefficient Climatic Zone

Wet-Freeze Wet-No Freeze Dry-Freeze Dry-No Freeze g0 -2.09 -1.429 -2.121 -2.024 g1 1.952 1.971 1.677 1.952 g2 -6.108 -6.174 -5.937 -6.107 g3 0.154 0.19 0.192 1.53 g4 -2.111 -2.079 -2.048 -2.113 g5 0.037 0.128 0.071 0.057 g6 0.261 1.075 0.762 0.492

25

Load Wave Shape for Tandem Axle

Crack or Joint

L j L j

4.0 ft

Overlay

Old Surface

5.0 ft L j

W ( t ) Load Wave Shape

[ W ( t )] n

2.0 ft 2.0 ft

5.0 ft L j

0.72 0.82

0.92 0.92

0.82 0.72

0.0 0.0

0.0 0.0

(0.72) n

(0.92) n

(0.82) n (0.82) n

(0.92) n

(0.72) n

(0.095) n

0.095

∆ t

(1 4 + L j ) ft.

Overlay

C

Thermal Stress Shear Stress

Bending Stress

Position I

Position II

NfB1 NfT1 NfS1

NfT2 NfS2

• NfB1 = Number of days for crack growth due to bending to reach Position I.

• NfT1 = Number of days for thermal crack growth to reach Position I.

• NfS1 = Number of days for crack growth due to shearing stress to reach Position I.

• NfT2 = Number of days for thermal crack growth to go from Position I to Position II.

• NfS2 = Number of days for crack growth due to shearing stress to go from Position I to Position II.

26

Calculated Number of Days

100%

0

Number of Days Damage

Perc

ent o

f Ref

lect

ed

36.8%

High severity

Medium+ High

High + Medium+ Low

ρLMH ρMH ρH

27

Calibration Quantities

Calibration Model Set

1 1 21 0 1 2 2 3 4

1 1 2

0 1 2 3 4

1 1 21 5 6 7 2 8 9

1 1 2

: , , , , ,

fB fB fTLMH fB fT

fT fS fS

LMH

fB fB fTMH fB fT

fT fS fS

N N NN N

N N N

Calibration Coefficients

N N NN N

N N N

Calibration Coeffi

ρ α α α α α

α α α α α β

ρ α α α α α

= + + + +

= + + + +

5 6 7 8 9

1 1 21 10 11 12 2 13 14

1 1 2

10 11 12 13 14

: , , , , ,

: , , , , ,

MH

fB fB fTH fB fT

fT fS fS

H

cients

N N NN N

N N N


α α α α α β

ρ α α α α α

α α α α α β

= + + + +

28

HOW DOES THE TIME-SCALE PARAMETER, ρ , VARY WITH

OVERLAY THICKNESS?

SENSITIVITY ANALYSIS

29

Sensitivity analysis of ρLMH for AC over AC pavement structure in a Dry-No Freeze

climate zone

30

10

100

1000

10000

100000

0 2 4 6 8

Scal

e co

effic

ient

(ρLM

H),

log

Thickness, inch

3002

5003

5004

3003

3004

3005

3006

3001

5006

5007

5008

3007

3008

Sensitivity analysis of ρH for AC over AC pavement structure in a Dry-No Freeze

climate zone

31

10

100

1000

10000

100000

1000000

0 2 4 6 8

Scal

e co

effic

ient

(ρH),

log

Thickness, inch

3002

5003

5004

3003

3004

3005

3006

3001

5006

5007

5008

3007

3008

Sensitivity analysis of ρMH for AC over JPC pavement structure in a Wet-Freeze

climate zone

32

10

100

1000

10000

100000

0 2 4 6 8 10 12

Scal

e co

effic

ient

(ρM

H),

log

Thickness, inch

12002 12003

13001 14005

14007 15002

22001 22004

30001 30002

30003 38003

38001 38005

13002 20005

22006 27001

32001 12001

12007 13008

14009 20008

20009 32002

38006

Sensitivity analysis of ρLMH for AC over Reinforcing over PCC pavement structure

in a Wet-Freeze climate zone

33

10

100

1000

10000

100000

0 2 4 6 8

Scal

e co

effic

ient

(ρLM

H),

log

Thickness, inch

25005 25007

25008 25009

25010 25011

25012 25013

25014 25015

25016 25017

25006 25018

25019 25020

25021 25022

25023 25024

25025 25026

25027 25028

Reflection Cracking Integration into Pavement ME Design

Harold L. Von Quintus

Webinar August 17, 2016

American Association of State and Highway

Transportation Officials

34

Outline for Session 2: 1. Overview of Enhancement to MEPDG 2. Inputs – Specific to Reflection Cracking 3. Calibration of Reflection Cracking Transfer

Function 4. Application/Demonstration of Reflection

Cracking Models for Rehabilitation Design

Enhancement to AASHTOWare Pavement ME® Design in FY2015:

Version 2.2 & 2.3

35

1. Judith Corley-Lay, P.E.; NCDOT, Chairperson 2. Vicki Schofield, AASHTO Project Manager 3. John Donahue, P.E.; Missouri DOT 4. William Barstis, P.E.; Mississippi DOT 5. Jay Goldbaum, P.E.; Colorado DOT 6. Marta Juhasz, P.E.; Alberta Transportation 7. Mehdi Parvini, P.E.; California DOT 8. Felix Doucet; TAC Liaison 9. Tom Yu, P.E.; FHWA Liaison 10. Shane Marshall, P.E.; Utah DOT, SCOJD Liaison 11. Jack Dartman, Montana DOT; T&AA Liaison

AASHTO Pavement ME Design Task Force Members:

36

Reflection Cracking Integration into Pavement ME Design

Based on results and methodology developed from NCHRP Project 1-41

A special thank you to: Bob Lytton and Sheng Hu (Texas Transportation

Institute): explanation on the models/equations. Halil Ceylan (Iowa State University): completed neural

networks.

37

Enhancement to MEPDG

Earlier Version; pre 2.2 Regression equation Fatigue cracks

Version 2.2 & Higher Fracture mechanics Fatigue cracks Transverse cracks

( ) ( )dbtcaeRC ++

=1

100( )( )

+

=iDILogci ec

CRCR5

4

100

38

Enhancement to MEPDG Earlier Version; pre 2.2 1. AC over AC 2. AC over PCC

Version 2.2 & Higher 1. AC over AC 2. AC over AC with seal

coat and interlayer 3. AC over intact JPCP 4. AC over fractured JPCP 5. AC over CRCP 6. Semi-Rigid Pavement 7. AC over Semi-Rigid

( ) ( )dbtcaeRC ++

=1

100( )( )

+

=iDILogci ec

CRCR5

4

100

39

Enhancement to MEPDG

Expanded Pavement Design Types: 1. Overlay with seal coat

and interlayer 2. Semi-rigid pavement 3. Overlay of semi-rigid

pavement 4. Overlay of PCC; intact

and fractured

40




41

Inputs to Software Performance criteria and reliability Condition of existing pavement Load transfer efficiency of cracks and/or joints Mixture properties

42

Performance Criteria and Reliability

AC of AC AC seal coat and interlayer of AC

AC of AC Pavements

43

Performance Criteria and Reliability

AC of PCC Pavements

AC of intact JPCP AC of fractured JPCP

AC of CRCP

44

Condition of Existing Pavement AC over AC AC over Semi-Rigid

45

Condition of Existing Pavement AC over Fractured JPCP

46

Condition of Existing Pavement Semi-Rigid Pavement

47

Load Transfer Efficiency Flexible and PCC pavements Measured in accordance with LTPP procedure Tied to crack severity for calibration

Severity LTE, percent Low 85

Medium 50 High 30

48

Overlay Mixture Properties No “new” or additional mixture properties needed

49




50

Sampling Matrix Ex

istin

g Pa

vem

ent

Con

ditio

n

Ove

rlay

Thic

knes

s Interlayer/Climate AC None Seal Coat

DF DNF WF WNF DF DNF WF WNF DF DNF WF WNF

Good Thick — — — — 8 — 6 2 3 — — — Thin — — 1 1 3 3 30 37 3 — — 3

Mod. Thick — — — — 3 — 5 — 1 — — 1 Thin — — — 1 3 3 22 7 2 — 2 1

Poor Thick — — — — 1 1 3 — 1 — — — Thin — — 1 4 8 5 30 13 4 — — 2

AC over AC Pavements

Data Sources: LTPP and other agency test sections. Total Number of Test Sections: 58

51

Sampling Matrix AC over PCC Pavements

Pavement Type

Existing Condition

Overlay Thickness

Climate

DF DNF WF WNF

Fractured Not Applicable Thick 4 18 31 8 Thin — — 3 1

Intact Good/Moderate

Thick 5 5 25 13 Thin 2 — 20 7

Poor Thick 2 2 22 — Thin 2 1 10 —

Data Sources: LTPP, New York City composite test sections, other agency test sections; 60 test sections.

52

Sampling Matrix Semi-Rigid Pavements

Pavement Type

Existing Condition

Overlay Thickness

Climate

DF DNF WF WNF

New AC over CTB Not Applicable

Thick 5 35 40 17

Thin 5 2 1 8

Data Sources: LTPP other agency test sections; Total number of sections: 55

53



Pavement Type AC over

AC AC over

Intact JPCP

AC over CRCP or Fractured

JPCP

Semi-Rigid

AC over Semi-Rigid

K1 0.012 0.012 0.012 0.45 0.012 K2 0.005 0.005 0.0002 0.05 0.005 K3 1.00 1.00 0.1 1.0 1.0 C1 3.22 0.1 1.0375 0.1 3.22 C2 25.7 0.52 1.8929 0.9809 25.7 C3 0.1 3.1 0.1 0.19 0.1 C4 133.4 79.3 262.1 165.3 133.4 C5 -72.4 -27.1 -9.6645 -5.1048 -72.4

Transverse Cracks

Critical coefficients, local calibration: C1, C2 and C5. 54



Pavement Type AC over

AC AC over

Intact JPCP

AC over CRCP or Fractured

JPCP

Semi-Rigid

AC over Semi-Rigid

K1 0.012 NA NA 0.45 0.012 K2 0.005 NA NA 0.05 0.005 K3 1.00 NA NA 1.00 1.00 C1 0.38 NA NA 1.64 0.38 C2 1.66 NA NA 1.1 1.66 C3 2.72 NA NA 0.19 2.72 C4 105.4 NA NA 62.1 105.4 C5 -7.02 NA NA -404.6 -7.02

Fatigue Cracks

Critical coefficients, local calibration: C1, C2 and C5. 55


AC over Flexible Pavements:

Fatigue Cracks

Transverse Cracks

56




57

Application of Models Sensitivity of load transfer efficiency or crack severity:

Load transfer efficiency is important.

58

Application of Models Eastern Colorado Existing AC Thickness: 6

in.

Distress Severity: Medium 90% Reliability

Effect of AC overlay thickness.

59

Application of Models Fractured JPCP Southern Arizona

Slab thickness – 10 inches AC overlay – 5 inches

Effect of reliability for transverse cracking.

60

Application of Models Fractured JPCP 90% Reliability

Slab thickness – 9 inches AC overlay – 5 inches

Effect of LTE for fractured JPCP.

61

Application of Models Fatigue cracking predictions for AC over AC.

62

Application of Models Transverse cracking predictions for AC over AC.

63

Application of Models Transverse cracking predictions for AC over fractured PCC.

Block cracking recorded in LTPP.

64

Reflection Cracking addendum is available through the ME-Design Resource Website for downloading the software: http:www.me-design.com Addendum #FY2015.4; dated August 2015.

65

QUESTION AND ANSWER SESSION

Comments & suggestions for future webinars are welcomed.

66