Design of HMA for Airfield Pavements Using the Superpave Gyratory Compactor

1. 2010 FAA Tech Transfer Conference Atlantic City, NJ Design of HMA for Airfield Pavements Using the Superpave Gyratory Compactor Allen Cooley, Ph.D. Burns Cooley Dennis, Inc.

2. Acknowledgements • AAPTP Program, Monte Symons • Project Panel • Jeff Rapol, Ray Rollings • H.D. Campbell, Jay Gabrielson • Casimir Bognacki • Others • Randy Ahlrich and Robert James • Ray Brown, Brian Prowell, and Andrea Kvasnak

3. Marshall is not a Mix Type. It is a Mix Design Method Item P401 or UFGS 32 12 15 Superpave is not a Mix Type. It is a Mix Design Method Highways or EB 59A Both are simply methods for proportioning asphalt binder and aggregates

4. Comparison of Mix Design Systems SuperpaveMarshall ≠

5. Approach for Adapting Superpave for Airfields • First, What Are We Defining As a Superpave Mix Design for Airfields? • Designed with Superpave Gyratory Compactor

6. Experimental Plan • Field and Laboratory Work • 10 Airfields • Conduct Performance Evaluations • Distress Mix Problem, Pavement Design Problem, or Construction Problem? • Obtain Mix Design and QC/QA Data • Obtain Cores From Projects • Obtain Materials from Original Sources

8. Experimental Plan • Reproduce HMA Using Materials From Original Sources • Compact Mix at 50 Blows • Compact Mix at 75 Blows • Compact Mix at 50 Gyrations • Compact Mix at 75 Gyrations • Compact Mix at 100 Gyrations

9. Experimental Plan • Distress To Evaluate >> Durability • Durability Problems Most Prevalent on Airfields • How? • Not Comfortable with Durability Tests Available • Use Rut Resistance to “Back Into” Durability • Add As Much Asphalt As Possible Without Rutting

10. Experimental Plan • Rutting Test • Repeated Load Permanent Deformation Test • Confining Pressure – 40 psi • Deviator Stresses • 100 psi • 200 psi • 350 psi

11. Test Results • When Comparing the Marshall and Superpave Mix Design Methods, It was Obvious that the Biggest Difference was the Design Compactive Effort • Evaluated By: • Ultimate Density • Comparison of Bulk Specific Gravity • “Durability” Testing

15. 50 Blow 67% of data Between 40 And 50 gyr 75 Blow 60% of data Between 50 And 60 gyr

18. Ndesign Values Data Recommended

19. Gradation • Evaluated Permeability to determine the lower (coarse) limits for gradation requirements • Permeability related to durability • Compared P401, UFGS 32 12 15, and Superpave Requirements

22. Gradation Requirements

23. Conclusions/Recommendations • Developed • Material Requirements (excluding binder – AAPTP 04-02) • Gradation Requirements • Design Compactive Efforts and Volumetric Requirements • Moisture Susceptibility (TSRs)

24. Material Requirements

25. Compactive Effort and Volumetrics

26. Compactive Effort and Volumetrics

27. Deliverables • Three Volumes to Report • Research Results • Guidelines on Mix Design and Mix Selection • Revised P401 for Designing with SGC www.aaptp.us

28. Thank You! Allen Cooley (601) 856-2332 acooley@bcdgeo.com