Effects of Aggregate Angularity on VMA and Rutting of KDOT Superpave Level 1Mixes

摘要

With the recent introduction and acceptance of Superpave design criteria for hotmix asphalt, designers have had difficulty meeting the minimum voids in the mineral aggregate (VMA) requirements. VMA is affected by compactive effort, gradation, and aggregate angularity. This research focused on the effects of fine aggregate angularity on VMA and rutting. Two 12.5-mm Superpave gradations, one coarse and one fine, were developed using 100% crushed limestone. Once the base line gradations were established, laboratory samples were produced with increasing natural sand percentages. The percentage of natural sand directly replaced the limestone on each sieve allowing the gradation to remain constant and the effect of fine aggregate angularity to be observed independent of gradation. The resultant VMA and fine aggregate angularity of each blend was compared.