Concrete Containing RAP for Use in Concrete Pavement

The feasibility of using concrete containing recycled asphalt pavement (RAP) in concrete pavement applications was evaluated. Concrete containing 0%, 10%, 20%, and 40% of RAP were produced in the laboratory and evaluated for their properties that are relevant to performance of concrete pavements. Results of the laboratory testing program indicate that compressive strength, splitting tensile strength, flexural strength, and elastic modulus of the concrete decreased as the percentage of RAP increased. The coefficient of thermal expansion and drying shrinkage did not appear to be significantly affected by RAP content. When a finite element analysis was performed to determine the maximum stresses in typical concrete pavements in Florida under critical temperature and load conditions, the maximum stresses in the pavement were found to decrease as the RAP content of the concrete increased, due to a decrease in the elastic modulus of the concrete. Though the flexural strength of the concrete decreased as RAP was incorporated in the concrete, the resulting maximum stress to flexural strength ratio for the concrete was reduced as compared with that of a reference concrete with no RAP. This indicates that using a concrete containing RAP could possibly result in improvement in the performance of concrete pavements.