Experimental and correlational study on the utilisation of RCA as an alternative coarse aggregate in asphalt mixtures

Over the past decades, growing population has created high demand for new road pavements. Due to considerable usage of various natural aggregates for constructing roads, these materials have started to deplete gradually. At the same time, the rate at which solid waste is generated in the society is increasing with the population growth and changes in the people life style. The management of solid wastes has become an acute problem. These challenges have attracted the attention of many to investigate the feasibility of the application of some of the waste materials as alternative materials in pavement construction. Among various waste materials, construction and demolition wastes, including Recycled Construction Aggregate (RCA), constitute a major part of the municipal solid wastes in Australia. Using RCA in asphalt mixtures results in significant economic and environmental benefits. However, in spite of such promising potentials, insufficient and inconclusive information on the engineering properties of RCA had limited the reliability and design specifications of RCA to date. In light of this, this paper aims to investigate the feasibility of RCA for the replacement of part of coarse aggregates. Accordingly, an experimental program is set up to evaluate the physical and mechanical properties of RCA. In addition, the comparison of RCA properties with virgin aggregates has been included as part of this investigation.