Aggregate Specifications for Stone Mastic Asphalt (SMA)

摘要

Stone matrix or stone mastic asphalt (SMA) is one of the more promising mixes to211u001ecome out of the European Study Tour. SMA mixes rely on a strong aggregate 211u001eskeleton structure to support wheel loads and a high asphalt content to provide 211u001edurability. Due to the stone-on-stone contact of property designed SMA mixes, 211u001ehigh quality, angular, rough-textured aggregates are typically recommended. 211u001eTypical specification requirements are a maximum LA Abrasion of 30 percent, 211u001ehowever, aggregates with and LA Abrasion as high as 40 percent have been 211u001esuccessfully utilized. The objectives of the study were to evaluate Kansas 211u001eaggregates for use in SMA mixes. Aggregates were selected that have LA Abrasions 211u001eof less than 30 percent, 31 to 40 percent and more than 40 percent. SMA mixes 211u001ewere made from the aggregates and the extracted aggregate evaluated to determine 211u001epercent degradation during laboratory compaction and testing. SMA samples were 211u001etested for performance using the Asphalt Pavement Analyzer to determine rutting 211u001eperformance. The results were analyzed to determine the relationships between 211u001eaggregate degradation and LA Abrasion.