Concrete Containing Recycled Concrete Aggregate for Use in Concrete Pavement

Abstract

This study evaluated the feasibility of using concrete containing recycled concrete aggregate (RCA) in concrete pavement application. Concrete containing 0%, 25%, and 50% RCA was produced in the laboratory and properties vital to the performance of concrete pavement were evaluated. Results from the laboratory testing program indicate that the compressive strength and elastic modulus are reduced slightly as the percentage of RCA increases. The flexural strength, splitting tensile strength, and coefficient of thermal expansion are about the same for concrete containing virgin aggregate and RCA. The free shrinkage increases slightly as the percentage of RCA increases. With the measured properties, a finite element analysis was performed to determine how the concretes containing the different amounts of RCA would perform if they were used in a typical concrete pavement in Florida. Analysis from the finite element model determined the maximum stresses under critical temperature and load conditions. Potential performance of the pavements was evaluated based on the computed maximum stress to flexural strength ratio. The maximum stress to flexural strength ratio in the pavement was found to stay about the same as the percentage of RCA increases. This indicates that RCA can be used in concrete pavement without affecting its performance.