Evaluation of Mix Designs for Rapid Construction of Bonded Concrete Overlays on Asphalt

Abstract

Road users in California have a low tolerance for delays during pavement rehabilitation. Therefore, the California Department of Transportation (Caltrans) is interested in evaluating bonded concrete overlays on asphalt (BCOA) as a potential rehabilitation alternative for distressed asphalt pavement. The use of high early strength concrete to facilitate rapid construction of BCOA has not been used in other U.S. states. This paper summarizes a complete study for the evaluation of concrete mix designs for rapid construction of BCOA that were placed on a set of full-scale test sections for accelerated pavement testing. Two types of mixes were created according to selected targets for opening times (OT) to traffic. The concrete mixes for use in night closures require an opening time of four hours, and the mixes for use in 55-hour weekend closures require an OT of 10 hours. Type III Portland cement and calcium sulfoaluminate (CSA) cement were used to design the 4H-OT mixes. Two 10H-OT mixes were designed using the same Type II/V portland cement. One of the 10H-OT mixes included light weight aggregate instead of a portion of conventional sand to evaluate the effects of this approach for internal curing to reduce drying shrinkage stresses.