Performance grading of the Lamont, Alberta C-SHRP pavement trial binders

Abstract

This paper documents and discusses an investigation into the improved performance grading of asphalt binders that were used in the Canadian Strategic Highway Research Program (C-SHRP) pavement trial in Lamont, Alberta. Binders were assessed for their tendency to reversibly age at low-temperatures. While the correlation between cracking severity and regular AASHTO M320 and MP1a grades was weak (r ²=0.73 and 0.49, respectively), the predictive ability of the BBR method increased significantly when binders were tested after 1, 3 and 8 days of conditioning (r ²=0.94–0.97). Brittle and ductile fracture energies were measured in single-edge-notched bending (SENB) and double-edge-notched tension (DENT), respectively. In the brittle state, the SENB test revealed little difference between the binders. However, in the ductile state, the DENT test revealed significant differences between materials, with binders that showed the least amount of cracking having the highest works of fracture at 0°C.

Keywords:

• Asphalt binder grading
• Transverse cracking
• Fatigue cracking
• Reversible aging
• Essential and plastic works of fracture
• Fracture energy