Resilient response of recycled concrete road aggregates

Abstract

This paper presents the results of a recent investigation on the performance of four recycled concrete aggregates (RCAs). The materials, obtained by crushing concrete with compressive strength ranging from 15 MPa to 75 MPa, were reconstituted to satisfy the grading requirements for a subbase material. Triaxial specimens were tested under repeated loading one day after compaction. It appears that the original concrete compressive strength, the amount of softer material in the RCA, and the flakiness index of the RCA can significantly affect the resilient modulus. Degradation is mostly related to the crushing of softer and flaky materials within the aggregate matrix. In this regard, the Ten Percent Fines test is suitable as an evaluation test as it does not impose an excessive force on the RCA. The overall results indicated that RCA may be utilized as a subbase or base course material if it can be produced to consistently meet product quality standards.