Performance Tests for Road Aggregates and Alternative Materials

Abstract

At least half the roughness and wheeltrack rutting that occur on surface courses in New Zealand are contributed to by aggregates used as base materials in thin surface granular pavements. At this point, there does not exist, in specifications, a reliable and cost-effective way to measure an aggregate's resistance to rutting. This study utilized several test methods of repeated load triaxial equipment to examine them for use in base course aggregate specifications. Traffic load limits were determined by pavement finite modeling and rut depth prediction methods. Results indicate that the average slope from the six stage repeated load triaxial test was the best predictor of traffic load limit. Therefore, this test was recommended for utilization in specifications for base courses.