Abstract:As part of SHRP 2, the University of California Pavement Research Center conducted two accelerated pavement tests to evaluate the effects of overlay thickness on the cracking performance of composite pavement composed of rubberized hot-mix asphalt with gap-graded aggregates and portland cement concrete (RHMA-G-PCC) by using the heavy vehicle simulator. Cracking failure mechanisms in these tests included both reflective cracking near the PCC joints and fatigue cracking in the PCC slabs. Increasing overlay thickness led to a significant increase in cracking life but at the same time increased rutting susceptibility. The data collected provide insights for design of RHMA-G-PCC composite pavements as well as calibration of related mechanistic-empirical models. The observations and findings from the two accelerated pavement test sections are summarized.