Properties of Recycled Concrete Aggregate for Unbound Pavement Construction

Abstract

The suitability of crushed concrete or recycled concrete aggregate (RCA) materials has been evaluated for use as pavement material for unbound basecourses. This paper covers the general engineering properties and response to cyclic loading as determined by repeated load triaxial testing (RLTT). In Australia, pavements commonly consist of granular basecourses and subbases supporting thin bituminous seals (asphalt or spray—chip seal). In this paper, a study is presented of the performances of three South Australian basecourse products, nominally 20 mm. The basecourse products included two RCA materials and a local virgin aggregate (quartzite). The resilient modulus and permanent deformation behaviour of RCA mixtures were investigated at different levels of moisture contents (90, 80, and 60% of optimum moisture content), subjected to a simplified stress regime suited to Australian construction. In terms of both resilient modulus and accumulation of permanent deformation, the RCA material performed better than the quartzite aggregate.