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Laboratory Performance Testing Update
Dr. Richard Willis
Assistant Research Professor
National Center for Asphalt Technology/Auburn University
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OverviewOverview
• Dynamic Modulus Testing• Dynamic Modulus Testing•
Asphalt Pavement Analyzer• Beam Fatigue•
State of Other Tests
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ObjectivesObjectives
• Provide an update on the results of completed•
Provide an update on the results of completed performance tests
P id d h f h•
Provide an update on the status of other tests to be completed
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Dynamic Modulus (E*)
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Dynamic Modulus TestingDynamic Modulus Testing
• Primary Input in MEPDGPrimary Input in MEPDG•
AASHTO TP 79‐09
– 4 and 20 °C4 and 20
C10, 1 and 0.1 Hz
– 3rd Temperature based on i h
dHigh PG Grade10, 1, 0.1 and 0.01 Hz
• Confined and unconfined• Confined and unconfined•
Master Solver creates mastercurves
AMPT
mastercurves
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Group Experiment Surface Mixtures
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GE+ Surface Mixtures
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Missouri Experiment
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Asphalt Pavement Analyzer (APA)
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Asphalt Pavement Analyzer
TestingAsphalt Pavement Analyzer Testing
• Superpave Gyratory Compactor specimensp p
• Reheated plant mix• Diameter: 150
mmDiameter: 150 mm• Height: 75 mm• Air Voids: 7
± 0 5%Air Voids: 7 ± 0.5%
APA Specimen
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MethodologyMethodology
• Temperature: 64CTemperature: 64C•
Load: 100 lbs• Pressure: 100
psiPressure: 100 psi• Repetitions: 8000 cycles•
Results• Results
– Automated and manual rut depthsp
– Secondary consolidation rateAPA Testing Device
• Go/No Go
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9.5 mm GE Mixtures
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9.5 mm GE+ Mixtures
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Other Surface mixtures
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2006 Test Track2006 Test Track
• Maximum allowable APA depth of 5 5 mm for•
Maximum allowable APA depth of 5.5. mm for 8,000 cycles
C l d 12 5 f T T k i•
Correlated to 12.5 mm of Test Track rutting•
Mixture susceptible to rutting
– High RAP/WMA
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Bending Beam Fatigue Tests
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Bending Beam Fatigue
TestingBending Beam Fatigue Testing
• Plant produced base mixtures
• Voids: 7% • Temperature: 20
°CTemperature: 20 C• Frequency: 10 Hz• Strain:
200 400
andStrain: 200, 400, and 800 με
Beam Fatigue Apparatus
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Beam Results
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GE and GE+ AnalysisGE and GE Analysis
• Field to Laboratory Comparisons•
Field to Laboratory Comparisons•
Use strain‐temperature relationships•
Determine field strain at 68 °F•
Determine number of beam cycles until failure yat this strain
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Field‐Lab Relationship (May 12)Mixture ε68 Nf
@ ε68 Nf % of Control
C t l 252 485 673 100%Control 252 485,673 100%
High RAP 252 438,074 90%
High RAP + Foam 254 1,729,710 356%
WMA ‐ Foam 325 794 570 164%WMA ‐ Foam 325 794,570 164%
WMA ‐ Additive 312 378,309 78%
Shell ‐ 7" 359 6,524,693 1,343%
Shell ‐ 9" 219 97,190,578 20,012%
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Kraton 387 16,359,625 3,368%
TLA 322 859,142 177%
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Field‐Lab Relationship (October 10)
Mixture ε68 Nf @ ε68 Nf % of ControlControl 340
493,102 100%
High RAP 247 477,011 96%
High RAP + Foam 254 1,729,710 350%
%WMA ‐ Foam 322 834,870 169%
WMA ‐ Additive 314 369,571 75%
Shell ‐ 7" 345 8,109,048 16,44%
Shell ‐ 9" 223 88,036,988 17,854%
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Kraton 369 24,117,492 4,890%
TLA 341 616,138 125%
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Beam Fatigue Preliminary SSummary
• Group Experiment–
High RAP + WMA and WMA –
Foam test sections are expected to last longer in fatigue than control section
• Group Experiment +–
All test sections are expected to perform better than the control test section
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Other Tests
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Other TestsOther Tests
• Performance Grading (Complete)•
Performance Grading (Complete)•
Multiple Stress Creep Recovery (Complete)•
Frequency Sweeps (Complete)•
Extracted Performance Grade (Complete)( p )
– RAP, WMA, TLA• APA Secondary Consolidation
(Complete)APA Secondary Consolidation (Complete)•
Flow Number (Sample Fabrication)
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Other TestsOther Tests
• Hamburg Wheel Tracking Device (Sample•
Hamburg Wheel Tracking Device (Sample Fabrication)
M i S ibili /TSR (S T i•
Moisture Susceptibility/TSR (Some Testing Complete)
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Indirect Tension Creep Compliance and Strength (Complete)
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Bending Beam Fatigue (Final Strain Level)•
Energy Ratio (Sample Fabrication
Complete)Energy Ratio (Sample Fabrication Complete)
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QuestionsQuestions
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