Cyclic Testing of Aggregates for Pavement Design

Two most commonly encountered aggregates that are used as subbases/bases of roadways in Oklahoma were selected and tested under cyclic loading to evaluate their Resilient Modulus (RM). Following the repeated triaxial RM testing, the specimens were subjected to the triaxial compression tests from which the parameters of cohesion (C), and friction angle (Φ) were obtained. A good statistical correlation was established between RM and C and Φ. The repeated triaxial RM testing procedure serves as a “conditioning” prior to the static triaxial compression and it simulates the loads imposed by the moving vehicle. The effects of conditioning on C and Φ were investigated. The strength increase through conditioning was found to vary from 18 to 85 percent, depending confining pressure and aggregate type. Also, it was found that C increases and ø decreased because of conditioning