Roller compacted concrete (RCC) pavements are strong and durable, but generally have a rough riding surface. The use of a bonded concrete overlay (BCO) improves pavement smoothness. In addition, the BCO increases pavement thickness and flexural strength of the composite pavement system. Previous research evaluated different methods of bonding the BCO to the RCC base. In this project, an MTS fatigue testing machine was used to test composite sections of an RCC beam overlaid with concrete. Loss of bond strength led to premature fatigue failure of the beam. Attempts were made to improve the fatigue life of RCC by employing three alternatives: internal curing, air-entrainment, and fiber reinforcement. Air entraining RCC, in addition to being a difficult procedure, did not provide a decisive result on improving fatigue life of RCC. Internally curing RCC gave the best results by improving fatigue life and increasing overall compressive strength. The fatigue life of the RCC-BCO composite beams was generally equal to or better than that of conventional concrete pavements.
Abstract