Volume 8, Issue 10 (November 2011)
Comparison of Specifications for Recycled Concrete Aggregate for Pavement Construction
This paper reviews existing specifications, specifically for the application of crushed concrete or recycled concrete aggregate (RCA) as pavement material for unbound subbases and basecourses. While the use of recycled crushed concrete is not new internationally, its application in Australia is unique as it is being commonly used as a granular basecourse/subbase supporting thin bituminous seals (asphalt or spray seal/chip seal). Commonality of specifications is explored and differences that exist are questioned. In light of practice outside of Australia, limitations by Australian authorities placed on recycled material inclusions other than crushed concrete are raised. In this paper, two South Australian-based RCA products, which were designed for use as pavement bases, are compared with current engineering specifications. The RCA products performed well in terms of resilient modulus and permanent deformation. However, properties such as abrasion resistance and wet/dry strength may restrict the application of the material if current specifications are justifiable.