Asphalt Performance Testing

Transcription

1 Asphalt Performance Testing National Asphalt Pavement Association 56 th Annual Meeting February 2011 Peter J. Stephanos, P.E. Director, Office of Pavement Technology Federal Highway Administration 1

2 Why Performance Testing? Volumetric design alone is not always sufficient o High traffic o Critical projects o Evaluate new materials and methods Engineering properties Needed for structural analysis o MEPDG 2

3 Why Performance Testing? Improve mix designs Obtain fundamental engineering properties Directly relate to in-service performance Support performance based specifications 3

4 Superpave Mixture Tests Shear test AASHTO T320 o Modulus o Permanent deformation Flexural fatigue AASHTO T321 o Fatigue cracking Indirect tensile test AASHTO T322 o Thermal cracking 4

5 Issues With SHRP Products High cost o Equipment o Training Prototype equipment Used with performance models o Errors o Not calibrated o Not user friendly 5

6 Performance Test Still Needed! FHWA and NCHRP Considered o Gyratory compactor modification o Asphalt pavement analyzer o Other Fundamental tests 6

7 Path for Test Development Research Commercial Equipment Need Draft Test Method Prototype Equipment Verification Specification First Article Equipment Ruggedness Critical Aspects Improve Test Method Equipment Production Equipment Provisional AASHTO Test Methods Round Robin Testing Precision and Bias Engineering Practice 7

8 Path for Test Development Need Research Superpave Performance Draft Test Method Prototype Test Equipment Verification Commercial Equipment Specification First Article Equipment Ruggedness Critical Aspects Improve Test Method Equipment Production Equipment Provisional AASHTO Test Methods Round Robin Testing Precision and Bias Engineering Practice 8

9 Path for Test Development Need Research Draft Test Method Prototype Equipment Verification Commercial Equipment FHWA research and NCHRP 9-19 Specification First Article Equipment Ruggedness Critical Aspects Improve Test Method Equipment Production Equipment Provisional AASHTO Test Methods Round Robin Testing Precision and Bias Engineering Practice 9

10 Path for Test Development Research Commercial Equipment Need Draft Test Method Prototype Equipment Verification Specification First Article Equipment Ruggedness Critical Aspects Improve Test Method Equipment Production Equipment NCHRP 9-29 Provisional AASHTO Test Methods Round Robin Testing Precision and Bias Engineering Practice 10

11 Recommended Tests Dynamic Modulus o Rutting o Cracking Flow Number (repeated load) o Rutting 11

12 Path for Test Development Research Commercial Equipment Need Draft Test Method Prototype Equipment Verification Specification First Article Equipment Ruggedness Critical Aspects NCHRP 9-29 Asphalt Mix ETG Improve AMPT Pooled Fund Test Method Equipment Production Equipment Provisional AASHTO Test Methods Round Robin Testing Precision and Bias Engineering Practice 12

13 Asphalt Mixture Performance Tester (AMPT) Machine Specifically for Testing Engineering Properties of Asphalt Mixtures: Dynamic Modulus Flow Number Fatigue Test (potential) 13

14 AMPT Pooled Fund Study TPF-5(178) Objectives o Procure AMPT for highway agencies o Provide training on AMPT o Support national AMPT implementation Progress and Schedule o Four AMPTs delivered o More AMPTs to be ordered in 2011 o One training course completed o Four additional courses scheduled in

15 AMPT Pooled Fund Study TPF-5(178) 15

16 Application of Performance Testing Mix Design and Evaluation o Identify potential performance issues Pavement Design o Engineering properties for MEPDG New Material Evaluation Construction Acceptance o Performance based specifications o Performance Monitoring 16