PERFORMANCE-RELATED TESTING OF STONE MASTIC ASPHALT (WITH DISCUSSION)

Based on years of field experience in Europe, stone mastic asphalt (SMA) has shown improved durability and resistance to rutting and fatigue cracking. The purpose of the research program presented herein was to evaluate the influence of long-term oven aging (LTOA), low temperature cracking, resilient modulus, rutting, and water sensitivity of SMA mixtures. The application of performance related test methods developed/used as a part of the Strategic Highway Research Program (SHRP) for SMA is discussed and several parameters which are significant for SMA are evaluated. Two types of SMA were investigated: (1) slabs from a road in Switzerland representing a field situation, and (2) samples produced in the laboratory with two extreme air void contents using the same aggregate gradation as the Swiss SMA.