Y. Richard Kim, Ph.D, P.E. North Carolina State University...Fortaleza, Brazil October 5, 2009....
Transcript of Y. Richard Kim, Ph.D, P.E. North Carolina State University...Fortaleza, Brazil October 5, 2009....
Asphalt Pavement Response and p pFatigue Performance Prediction Using the VECD Approach‐Application tothe VECD Approach Application to
Warm Mix Asphalt
Y. Richard Kim, Ph.D, P.E.North Carolina State University
Presented at the International Workshop onCold and Warm Asphalt Mixture Design/Characterization
and Pavement DesignIdentification of Worldwide Best Practices
Fortaleza, Brazil
October 5, 2009
Outline
FHWA PRS ProjectVEPCD ModelVEPCD Model• Characterization• Verification• Verification• Application
NCHRP 1 42A I t t d VECD FEP++NCHRP 1-42A Integrated VECD-FEP++
FHWA HMA‐PRS ProjectFo r ear long project started in Feb 2007Four year long project started in Feb. 2007Objectives
T d l i t l f t ti d l i f HMA • To develop various tools for testing and analysis of HMA mixture
• To develop a hierarchical system for performance-related p y pspecification
The original research plan includes a wide range of HMA mixtures from various pavement sections.Recently incorporated RAP and WMA mixtures from NCAT Test Track and Manitoba projects
Summary of PRS PavementsSummary of PRS Pavements FHWA ALF Pavements (control and modified)FHWA ALF Pavements (control and modified)NY I-86 Perpetual PavementsNCAT RAP and WMA PavementsNCAT RAP and WMA Pavements• Control, OGFC w/15% RAP, High RAP (50%), High RAP
plus WMA (Evotherm and Advera)Manitoba RAP and WMA Pavements• WMA (Sasobit, Advera, Evotherm)• RAP (0, 15, 50%)
Chinese Perpetual Pavements in Binzhou, ShandongKEC Test Road Pavements
Proposed Hierarchical PRSProposed Hierarchical PRSModel Description Level 1 Level 2 Level 3
E* Unconfined and Confined E* AMPT E* IR E* and 55°C
Predictive Equation
CrackingPredictive Equation for
VEPCD Coefficients
HMA Model
Cracking(Tension) Uniaxial VEPCD Uniaxial VEPCD VEPCD Coefficients
from Mix Characteristics
Rutting (Compression) MVEPCD VP at a Representative
Confining Pressure
Predictive Equation for VP Coefficients from Mix Characteristics
Pavement Model MVEPCD-FEP++ Layered Viscoelastic Model
Layered Viscoelastic Model
Testing Time 17 days 5 days Less than 1 dayA l i Ti 3 d 2 d L th 1 dAnalysis Time 3 days 2 days Less than 1 day
Total Time 20 days 7 days 1 day
VEPCDModelVEPCD ModelViscoelastoplastic Continuum Damage (VEPCD) ModelViscoelastoplastic Continuum Damage (VEPCD) Model
W kTime-
T tElastic- WorkPotentialTheory
Temperature Superposition with Growing
Damage
Viscoplastic Model
ElasticViscoelastic
Correspondence Principle
Linear Viscoelastic
Microcracking Related
Time-Temperature
Damage
Permanent DeformationViscoelastic
EffectsRelated
DegradationTemperature
EffectsDeformation
Growth
VEPCDModeling ApproachVEPCD Modeling Approach
Elastic
Monotonic Tests at 5°C or
C clic Tests at 19°C
Monotonic Tests at 5°C or
C clic Tests at 19°CStrain Hardening VP Model
Strain Hardening VP Model
ElasticLVE
Damage PlasticDamage Characteristic R l ti hi
Damage Characteristic R l ti hi
Cyclic Tests at 19°CCyclic Tests at 19°C
εεε +(Microcracking) VPRelationshipRelationship
vpvetotal εεε +=
VECD ModelVECD Model
Linear Viscoelastic Creep ComplianceLinear Viscoelastic Creep Compliance
Viscoplastic CoefficientsViscoplastic Coefficients
VECD ModelVECD ModelDynamic Modulus Test
and InterconversionDynamic Modulus Test
and InterconversionMonotonic Tests
at 40°CMonotonic Tests
at 40°C
VECD Experimental Program
Dynamic modulus (LVE Characterization)• -10°, 5°, 20°, 40° and 54°C10 , 5 , 20 , 40 and 54 C• 25, 10, 5, 1, 0.5 and 0.1 Hz• 50 – 75 microstrain peak-to-peak strain amplitude50 75 microstrain peak to peak strain amplitude• Tension-compression protocol
Monotonic at 19°C or controlled crosshead cyclic Monotonic at 19 C or controlled crosshead cyclic at 19°C and 10 Hz (Damage Characterization)
Linear Viscoelastic Behaviori ea i oe a i e a io
2 E+04
3.E+04
30
35
40
deg)
1.E+04
2.E+04
|E*|
(MPa
)
10
15
20
25
Pha
se A
ngle
(d
0.E+001.E-05 1.E-02 1.E+01 1.E+04
Reduced Frequency (Hz)
0
5
1.E-05 1.E-02 1.E+01 1.E+04
Reduced Frequency (Hz)
P2
4
6From MeasureFitted
1.E+04
1.E+05
)
-2
0
2lo
g a T
1.E+03|E*|
(MPa
)
-6
-4
-20 0 20 40 60Temperature (C)
1.E+021.E-05 1.E-02 1.E+01 1.E+04
Reduced Frequency (Hz)
Damage Characteristic CurvegCyclic and Monotonic
1.005C - 126 me
0.80
5C 126 me5C - 150 me19C - 190 me19C - 240 me
0.60
C*
19C - 240 me27C - 520 me27C -668 meMonotonic
0.40Monotonic
0 00
0.20
0.000.E+00 2.E+05 4.E+05 6.E+05 8.E+05
S
St d Mi tStudy MixturesFHWA ALF pooled fund study TPF 5(019)FHWA ALF pooled fund study TPF-5(019)Four mixtures each the same coarse 12.5 mm gradation with the same asphalt content (5 3%)with the same asphalt content (5.3%)• Unmodified PG 70-22 (Control)• Crumb Rubber Terminal Blend (CRTB, PG 76-28)Crumb Rubber Terminal Blend (CRTB, PG 76 28)• Styrene Butadiene Styrene (SBS, PG 70-28)• Ethylene Terpolymer (Terpolymer, PG 70-28)
ALF Mixtures ComparisonLVE Characteristics
40000 100000
30000
40000ControlCRTBSBS
100000
20000
*| (M
Pa) Terpolymer 10000
10000
|E*
1000
01.E-08 1.E-05 1.E-02 1.E+01 1.E+04
1001.E-08 1.E-05 1.E-02 1.E+01 1.E+04
Reduced Frequency (Hz) Reduced Frequency (Hz)
Simplified FormulationV ifi iVerification
0.8
1.019-CX-L 19-CX-L (2)19-CX-H 5-CX-L5-CX-H (2) 5-CX-H 0.8
1.019-CX-L19-CX-H19-CS-L19 CS H
0.4
0.6
C*
5 CX H (2) 5 CX H19-CS-L 19-CS-H5-CS-H Monotonic
0.4
0.6
C*
19-CS-H5-CS-HMonotonic
0.0
0.2
0.E+00 2.E+05 4.E+05 6.E+05 8.E+05 1.E+06S
0.0
0.2
0.E+00 1.E+05 2.E+05 3.E+05 4.E+05 5.E+05S
ControlControl CRTBCRTB
S S
0.8
1.019-CX-L19-CX-H19-CS-L19-CS-H
0.8
1.019-CX-L19-CX-H19-CS-L19-CS-H
0 2
0.4
0.6
C*
19 CS H5-CS-HMonotonic
0 2
0.4
0.6
C*
19 CS H5-CS-HMonotonic
0.0
0.2
0.E+00 1.E+05 2.E+05 3.E+05 4.E+05 5.E+05 6.E+05 7.E+05S
0.0
0.2
0.E+00 1.E+05 2.E+05 3.E+05 4.E+05 5.E+05S
TerpolymerTerpolymerSBSSBS
VECD Comparison of ALF MixturesDamage Characteristics
1.0Control
0.8
ControlSBSTerpolymer
0.6
C*
p yCRTB
0 2
0.4
0.0
0.2
0.E+00 2.E+05 4.E+05 6.E+05 8.E+05 1.E+06S
VEPCDModel VerificationVEPCD Model Verification
Random Loading ValidationRandom Stress le el and frequency 87 5 650 kPa 1 20 Hz 25°CRandom Stress level and frequency, 87.5‐650 kPa, 1‐20 Hz, 25 C
600
700
400
500
600s
(kPa
)
100
200
300
Stre
ss
00 200 400 600 800 1000 1200 1400
Time (s)700 25600
200300
400500
600700
tress
(kPa
)
10
15
20
25
eque
ncy
(Hz)
200
400
600
mbe
r of C
ycle
s
0100
200
0 5 10 15 20 25 30
Loading Block
St
0
5
0 5 10 15 20 25 30
Loading Block
Fre
0
200
0 5 10 15 20 25 30
Loading Block
Num
Random Loading Verificationa o oa i g e i i a io1.5E-02
6 0E 03
8.0E-03
Measured
Predicted TotalControlControl CRTBCRTB
5.0E-03
1.0E-02
Stra
in
Measured
Predicted Total4.0E-03
6.0E-03
Stra
in
Predicted Total
Predicted VP
0.0E+00
5.0E 03
0 200 400 600 800
Predicted VP
Predicted VE0.0E+00
2.0E-03
0 200 400 600 800
Predicted VE
Time (s) Time (s)
6.3E-03Measured
Predicted Total8 0E 03
1.2E-02
Measured
Predicted TotalTerpolymerTerpolymerSBSSBS
2.1E-03
4.2E-03
Stra
in
Predicted VP4.0E-03
8.0E-03
Stra
in
Predicted VP
0.0E+000 50 100 150 200
Time (s)
Predicted VE0.0E+00
0 75 150 225 300Time (s)
Predicted VE
MEPDG Fatigue ModelMEPDG Fatigue Model1000
ude
5C Measured
19C Measured
Am
plitu 27C Measured
Stra
in A
1001.E+01 1.E+03 1.E+05 1.E+07
Nf (Cycle)
Fatigue Life Prediction UsingFatigue Life Prediction Using Monotonic Data
0 8
1 1
0 4
0.6
0.8
C*
0 4
0.6
0.8
C*
5 CX L P di t d
0
0.2
0.4
19-CX-VL-Measured19-CX-VL-Measured19-CX-H-Predicted19-CX-H-Measured
0
0.2
0.4 5-CX-L-Predicted5-CX-L-Measured5-CX-H-Predicted5-CX-H-Measured
00.0E+00 1.0E+06 2.0E+06 3.0E+06 4.0E+06
Reduced Time (s)
00.0E+00 5.0E+03 1.0E+04 1.5E+04 2.0E+04 2.5E+04
Reduced Time (s)
Failure Criteria
4000
50
3000
E*|
40
e A
gnle
1000
2000|
30 Phas
|E*| Nf
00 E+00 1 E+03 2 E+03 3 E+03 4 E+03 5 E+03
20
|E |Phase Angle (a)
f
0.E+00 1.E+03 2.E+03 3.E+03 4.E+03 5.E+03Number of Cycles
VECD Failure CriteriaVECD Failure Criteria1.0
ALF Control0.8
re
ALF ControlALF CRTBALF Terp.Mix A
0 4
0.6
@ F
ailu
r Mix AFailure Envelope
0.2
0.4
C*@
0.00 5 10 15 20 25 300 5 10 15 20 25 30
Temperature (deg. C)
Prediction of Nf vs εt FatiguePrediction of Nf vs. εt Fatigue Relationship
1000
e
5C Measured19C Measured27C M d
mpl
itude 27C Measured
Predicted
Stra
in A
100
S
1.E+01 1.E+03 1.E+05 1.E+07
Nf (Cycle)
Prediction of Fatigue LifeCh i d i h C liCharacterized with Cyclic
1.E+06R2 = 0.91Se/Sy = 0.37
1.E+04
1.E+05Pr
edic
ted
Nf
E i CX C t l CX
1.E+02
1.E+03
1.E+02 1.E+03 1.E+04 1.E+05 1.E+06
P Eric-CX Control-CXCRTB-CX Terpolymer-CXEric-CS Control-CSCRTB-CS SBS-CSTerpolymer-CS LOE
Measured, Nf
3.E+05
4.E+05
Nf
R2 = 0.86Se/Sy = 0.37
1.E+05
2.E+05
Pred
icte
d
Eric-CX Control-CXCRTB-CX Terpolymer-CXEric-CS Control-CS
0.E+000.E+00 1.E+05 2.E+05 3.E+05 4.E+05
Measured, Nf
Eric CS Control CSCRTB-CS SBS-CSTerpolymer-CS LOE
Fatigue Life VerificationMultiple mixtures 10 H 100 700 5° 19° and 27°CMultiple mixtures, 10 Hz, 100 – 700 με, 5 , 19 , and 27 C1.E+06
S9.5C S9.5BI19C B25B
1.E+05
f
I19C B25BI19B RS12.5CRI19B RI19CRB25B LOE
1.E+04
dict
ed N
1.E+03
Pred
1 E+02
5 ~ 30% Error(in arithmetic space)
5 ~ 30% Error(in arithmetic space)
1.E 021.E+02 1.E+03 1.E+04 1.E+05 1.E+06
Measured Nf
Fatigue Endurance Limit
1E+03
gUsing VECD Model
Endurance Limit
1E+02n Le
vel
Stra
in
1E+01
5C19C
1E+011.E+01 1.E+05 1.E+09
Nf50 million
Effect of Mixture Variables
250
)
250
)
Solid Symbols = Modified Mixes
100
150
200
ance
Lim
it ( με
100
150
200
ance
Lim
it ( με
0
50
100
0 5 10 15 20 25 30
Endu
ra
0
50
100
4 4.5 5 5.5 6 6.5 7
Endu
ra
Aggregate SizeAggregate Size Asphalt ContentAsphalt Content
NMAS % AC
200
250
t (με)
200
250
t (με)
100
150
dura
nce
Lim
it
100
150
dura
nce
Lim
it
0
50
58 64 70 76 82
High Temperature PG Grade
En
0
50
1 2 3 4
Use of RAP Materials
EnAsphalt GradeAsphalt Grade RAP EffectRAP Effect
RAPNo-RAP
Thermal Cracking Verification4000
3000
4000-4.4C/hr-8.6C/hr-17.7C/hr
2000
3000
ss (k
Pa)
1000
Stre
s
LVE
VECD
00 150 300 450
VEPCD
Actual
0 150 300 450Time (min)
TSRST Prediction4500 450
3000
3500
4000
Stre
ss (k
Pa)
250
350
Tim
e (m
in)
2000
2500
3000
0 5 10 15 20 25
Failu
re S
Filled Symbols: PredictedClear Symbols: Measured
50
150
0 5 10 15 20 25
Failu
re T
Filled Symbol: PredictedClear Symbols: Measured
0 5 10 15 20 25Cooling Rate (C/hr)
0 5 10 15 20 25Cooling Rate (C/hr)
-20
ure
at
(C)
-25
Tem
pera
tFa
ilure
(
Filled Symbols: PredictedCl S b l M d-30
0 5 10 15 20 25
Cooling Rate (C/hr)
Clear Symbols: Measured
Predictions from the VEPCD ModelPredictions from the VEPCD ModelStress-strain behavior of asphalt mix in:• monotonic tests at varying rates of loading and
temperature; and• random load cyclic tests under varying stress/strain random load cyclic tests under varying stress/strain
magnitudes, temperatures, and loading frequencies.Nf vs. εt relationship at various temperaturesf tEndurance limitTSRST results under different cooling rates i l diincluding:• thermal stress development history;
fracture time fracture stress and fracture • fracture time, fracture stress, and fracture temperature.
VECDModel ApplicationVECD Model Application
Fatigue Performance PredictionFatigue Performance Prediction of HMA Pavement
Two-Step Method• Pavement response model (3-D FEP++) plus VECD Pavement response model (3 D FEP ) plus VECD
modelIntegrated MethodIntegrated Method• Finite element simulation of damage under
continuous loading cyclescontinuous loading cycles
Two‐Step Method
3-D FEMLinear VE HMAElastic Base/SG
PavementResponse
ModelElastic Base/SG
ε kernel
Model
M t i l
VECD Model
MaterialLevel
PerformanceModel
Transfer FunctionsModel
Predicted Distresses
Effect of Material TypeypVertical Strain
ControlControl SBS ModifiedSBS ModifiedControlControl SBS-ModifiedSBS-Modified
ALF PavementTransverse Strain ResponseTransverse Strain ResponseVECD Input Kernel
3E-04ControlCRTBSBS
2E-04
∗f(ξ)
SBSTerpolymer
1E-04
ε0∗
0E+000 0.2 0.4 0.6 0.8
Time (s)
ALF Mixtures ComparisonDamage Characteristics
1.0Control
0.8
ControlSBSTerpolymer
0.6
C*
p yCRTB
0 2
0.4
0.0
0.2
0.E+00 2.E+05 4.E+05 6.E+05 8.E+05 1.E+06S
ALF Fatigue Life Prediction
y = 0.7119x + 2.321R2 = 0.84736.4
6.6SBSControlCRTB
6
6.2
edic
ted
Nf CRTB
EVYNo Terpolymer
y = 0.6189x + 2.73915 6
5.8
log
Pre With Terpolymer
yR2 = 0.9932
5.4
5.6
4 4 4 6 4 8 5 5 2 5 4 5 64.4 4.6 4.8 5 5.2 5.4 5.6log Field Nf
Integrated Method
M-E PDGM-E PDGPavement
Fully MechanisticFully Mechanistic
3 D FEM withLayered Elastic Model
σ ε
PavementResponse
Model
3-D FEM withVEPCDInterfaceFractureσ, ε
Performance Prediction Model
MaterialLevel
Performance
HealingAging
Nonlinear Base/SG
Transfer FunctionsModel
Transfer Functions
Predicted Distresses Predicted Distresses
Simulation Results (Damage)Simulation Results (Damage)Only Mechanical Loading
Thin Pavement Thick Pavement
C: 0.25 0.3 0.35 0.4 0.45 0.5 0.55 0.6 0.65 0.7 0.75
Pavement Simulation for Lime‐Pavement Simulation for LimeModified Mix Evaluation
16.855cm
Viscoelastic AC Layer
Pressure 827.37kPa
10cm
Linear Base 75ksi (517107kPa) 20.3cm
Subgrade 10.9ksi (75056kPa)
Effect of Moisture ConditioningEffect of Moisture ConditioningCycles Control Control Moisture Lsub Lsub Moisture
50,000 0 0.1 0.2 0.3 0.4 0.5
0
0.05
0.1 0 0.1 0.2 0.3 0.4 0.5
0
0.05
0.1 0 0.1 0.2 0.3 0.4 0.5
0
0.05
0.1 0 0.1 0.2 0.3 0.4 0.5
0
0.05
0.1 100,000
0 0.1 0.2 0.3 0.4 0.5
0
0.05
0.10 0.1 0.2 0.3 0.4 0.5
0
0.05
0.10 0.1 0.2 0.3 0.4 0.5
0
0.05
0.10 0.1 0.2 0.3 0.4 0.5
0
0.05
0.10 0.1 0.2 0.3 0.4 0.5 0 0.1 0.2 0.3 0.4 0.5 0 0.1 0.2 0.3 0.4 0.5 0 0.1 0.2 0.3 0.4 0.5
500,000 0 0.1 0.2 0.3 0.4 0.5
0
0.05
0.1 0 0.1 0.2 0.3 0.4 0.5
0
0.05
0.1 0 0.1 0.2 0.3 0.4 0.5
0
0.05
0.1 0 0.1 0.2 0.3 0.4 0.5
0
0.05
0.1 1,000,000
0
0.05
0
0.05
0
0.05
0
0.051,000,000 0 0.1 0.2 0.3 0.4 0.5
0.1 0 0.1 0.2 0.3 0.4 0.50.1 0 0.1 0.2 0.3 0.4 0.5
0.1 0 0.1 0.2 0.3 0.4 0.50.1
2,500,000 0 0.1 0.2 0.3 0.4 0.5
0
0.05
0.1 0 0.1 0.2 0.3 0.4 0.5
0
0.05
0.1 0 0.1 0.2 0.3 0.4 0.5
0
0.05
0.1 0 0.1 0.2 0.3 0.4 0.5
0
0.05
0.1 0 0 0 0
5,000,000 0 0.1 0.2 0.3 0.4 0.5
0
0.05
0.1 0 0.1 0.2 0.3 0.4 0.5
0
0.05
0.1 0 0.1 0.2 0.3 0.4 0.5
0
0.05
0.1 0 0.1 0.2 0.3 0.4 0.5
0
0.05
0.1 7,500,000
0 0.1 0.2 0.3 0.4 0.5
0
0.05
0.1 0 0.1 0.2 0.3 0.4 0.5
0
0.05
0.1 0 0.1 0.2 0.3 0.4 0.5
0
0.05
0.1 0 0.1 0.2 0.3 0.4 0.5
0
0.05
0.1 10,000,000
0 0.1 0.2 0.3 0.4 0.5
0
0.05
0.1 0 0.1 0.2 0.3 0.4 0.5
0
0.05
0.1 0 0.1 0.2 0.3 0.4 0.5
0
0.05
0.1 0 0.1 0.2 0.3 0.4 0.5
0
0.05
0.1
C: 0.25 0.3 0.35 0.4 0.45 0.5 0.55 0.6 0.65 0.7 0.75
NCHRP 1‐42A VECD‐FEP++NCHRP 1‐42A VECD‐FEP++
Aging Stiffness|E*|
DamageM t i CS CX
ViscoplasticM t i
HealingC lig g |E | Monotonic, CS, CX Monotonic Cyclic
MaterialMaterial Characteristics(VECD + Aging)Pavement
Structure
Base Layer(Non-linear Elastic)
Subgrade
VECD-FEP++
g(Linear Elastic)
Moisture(EICM)
Traffic Loading(Non-uniform, Single, Dual)
ResponseStrain, Damage
Temperature(EICM)
Mesh Size Sensitivity Check
InterpretationCondition Index
Effect of Aging on |E*|100000100000
AL-STAAL-LTA1AL-LTA2
10000
*| (M
Pa)
AL LTA2AL-LTA3
1000|E
(b)
1001.E-08 1.E-05 1.E-02 1.E+01 1.E+04
(b)
Reduced Frequency (Hz)
Effect of Aging on Phase Angle45
35
40
45
g)
AL-STAAL-LTA1
20
25
30
Ang
le (d
e AL-LTA2AL-LTA3
10
15
20
Phas
e A
0
5
1.E-08 1.E-05 1.E-02 1.E+01 1.E+04
Reduced Frequency (Hz)
Effect of Aging on VECD Model
0.8
1.0
AL-STAAL-LTA1
0.6
C
AL LTA1AL-LTA2AL-LTA3
0 2
0.4
C
0.0
0.2
0.E+00 1.E+05 2.E+05 3.E+05 4.E+05S
Healing ModelHealing ModelKim, Lee, and Little (AAPT 1997)
Pa)
Region IIRegion I
Pa)
Region IIRegion I
iffne
ss (k
P
RSB’iff
ness
(kP
RSB’
Pse
udo
St R
BSBR
CSC
D’
Pse
udo
St R
BSBR
CSC
D’
P
DΔNf
P
DΔNf
No. of CyclesNo. of Cycles
Modified Healing ModelModified Healing ModelNCHRP 1‐42A
CΔCΔCCΔ
S1, ΔSi
S2, ΔSi
CCΔ
S1, ΔSi
S2, ΔSi2 i
S2, ΔSj
2 i
S2, ΔSj
kPa)
0
2 oadi
ng
kPa)
0
2kPa)
0
2 oadi
ng
kPa)
0
2 oadi
ng
kPa)
0
2kPa)
0
2 oadi
ng
restξrestξ
o S
tiffn
ess
(k 4
13
5
Lo
Time
0 1 3 52 4
o S
tiffn
ess
(k 4
13
5o S
tiffn
ess
(k 4
13
5
Lo
Time
0 1 3 52 4
o S
tiffn
ess
(k 4
13
5
Lo
Time
0 1 3 52 4
o S
tiffn
ess
(k 4
13
5o S
tiffn
ess
(k 4
13
5
Lo
Time
0 1 3 52 4
Pseu
do Time
Pseu
doPs
eudo Time
Pseu
do Time
Pseu
doPs
eudo Time
Damage, SDamage, SDamage, SDamage, SDamage, SDamage, S
Simulation Results (Cracking Index)i u a io e u ( a i g I e )Mechanical and Thermal Loading, Aging, Healing, and
Viscoplasticity
Thin Pavement Thick Pavement
CI: 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9
Summary
VEPCD model’s ability to predict material’s behavior at a wide range of conditionsgCracking simulation of VECD-FEP++ does not need to know the crack location a priorineed to know the crack location a priori.Thermal stress, aging, healing, viscoplasticity models implemented into VECD FEP++models implemented into VECD-FEP++VECD-FEP++ as a tool to investigate and
d l WMA t i l d tmodel WMA materials and pavements
Thank you!Thank you!
NCAT Test Track Cross Section
Control, OGFC, Foam WMA,
Evotherm WMA
Control, OGFC, Foam WMA,
Evotherm WMA1.25” (32 mm)Surface (9.5 mm)
2.75” (70 mm)Intermediate (19 mm)
NCAT T t T k3.00” (76 mm)Base (19 mm)NCAT Test Track
50% RAP, 50% RAP with Foam
WMA
50% RAP, 50% RAP with Foam
WMA6.00” (152 mm)
Dense Graded Aggregate Base
WMAWMA
Stiff Subgrade
Summary of NCAT MixturesHMA Mixtures• Control, OGFC (15% RAP) ( )• High RAP (50%), High RAP + WMA
WMA• Evotherm (additive), Advera (foam)
RAP• 0 15 50% RAP• 0, 15, 50% RAP
Binder Grades• Surface/Intermediate layersSurface/Intermediate layers
No RAP – PG 76-22With High RAP – PG 67-22
• Base layer• Base layerPG 67-22
Summary of MIT MixturesWMA Project• WMA AdditivesWMA Additives
Advera, Sasobit, Evotherm
• Layer PropertiesSurface layer – 0% RAP, 150/200 penIntermediate layer – 30% RAP, 200/300 pen
RAP ProjectRAP Project• RAP
0, 15, 50%
• Binder150/200 pen for all % RAP, also 200/300 pen for 50% RAP
B M t i l ( t l d)• Base Materials (not sampled)70% RAP
MIT RAP SectionsMIT RAP Sections2 5 km
0% RAP150/200
15% RAP150/200
50% RAP150/200
50% RAP200/300 0 m
m
2.5 km
150/200 pen 150/200 pen 150/200 pen 200/300 pen 100
m
70% RAP Base Layer
100 m
m
MIT WMA SectionsMIT WMA Sections3 km 1 km0.5 km 3 km 3 km 0.5 km1 km
HMA Advera HMA Sasobit HMA Evotherm HMA
50 m
m
3 km 1 km0.5 km 3 km 3 km 0.5 km1 km
+30%RAP +30% RAP +30%
RAP +30% RAP +30%RAP +30% RAP +30%
RAP 50 m
m