Accelerated Testing of Full-Scale Thin Bonded Concrete Overlay of Asphalt

A research study was conducted with the goal of determining the expected performance life of thin bonded concrete overlay of asphalt (BCOA) in California. Eleven thin BCOA sections were built and tested with the Heavy Vehicle Simulators (HVS) in Davis, California. The performance of the sections in the HVS testing provided insight into the mechanics of the thin BCOA structures and the effects the different rapid-strength concrete materials, traffic, jointing, and base factors on their performance, including testing in both very wet and very dry conditions. Overall, the performance of the thin BCOA sections in the HVS testing was excellent. The eleven sections resisted the predefined HVS loading without cracking. In five of the sections, that loading was equivalent to 6 million single-axle loads and included load levels more than twice the legal limit in California, channelized traffic at the shoulder edge of the slabs, and a continuous water supply that simulated flooded conditions. The main conclusion from this research study is that a well-designed, well-built thin bonded concrete overlay with half-lane width slabs placed on top of an asphalt base that is in fair to good condition can provide 20 years of good serviceability on most of California's non-interstate roadways.