A framework for the integrated cost-benefit analysis of the use of recycled aggregate concrete in structural applications

Recycled concrete waste in the form of recycled concrete aggregate (RCA) is presently used mostly as a road base filler replacing natural aggregate in Australia. However, instead of manufacturing Natural Aggregate Concrete (NAC) using Natural Aggregate (NA) as a constituent material to use in structural applications, there is potential to use RCA replacing NA to manufacture Recycled Aggregate Concrete (RAC). This paper presents a framework to estimate the costs and benefits of producing RAC, against producing NAC. The framework applies to the system boundary of production processes of RAC, NAC and the life cycle of their respective constituent materials. Cost-benefit assessment (CBA) is identified as an appropriate method to evaluate the internalised impacts as well as external costs concerning the use of both RAC and NAC. This paper proposes a framework to cover the primary impacts which are directly attributable to the RAC or the NAC, as well as the secondary impacts which results in the immediate boundary due to the proposed changes using CBA. The basic methodology for the evaluation of the above impacts considering technical, financial, environmental and social perspectives to obtain a comparable value is discussed in the paper