Integrated assessment on the use of Recycled Concrete Aggregate (RCA) in structural concrete

The objective of this research is to facilitate comparison of using an alternative material in a construction application against the virgin material counterpart, through providing a holistic and an integrated evaluation that can be considered as a representative indicator in policy decision making. The study adopts the case of using recycled concrete aggregate in structural concrete as a case study and evaluates the net benefit to society with the uptake of the initiative. This research is published in six journal research articles. The research integrates multi-disciplinary knowledge and presents a comprehensive evaluation methodology to evaluate the suitability of a building material, covering both the manufacture and use phases of RAC. The methodology employs a systematic approach to conduct a complete evaluation, which enables to determine future course of action. The results suggest that RAC is marginally expensive with the adoption costs and the direct environmental impact is similar to that of NAC production. However, the indirect environmental impact results in a significant positive value, indicating a positive NPV with the manufacture of RAC and the use of it in structural applications. The result leads to the conclusion that private operators do not find production of RAC financially viable, yet society benefits with its production. Therefore, the study recommends the use of economic instruments based on ‘the polluter pays’ principle to promote RAC production, in order to internalise the external costs/benefits remaining outside the market pricing system and enable their realisation. Outcome The work provides a systematic, comprehensive and complete methodology to evaluate the use of an alternative material in a construction application that provides a representative answer for public/government policy decision making to encourage or discourage its uptake. The methodology is demonstrated in detail by taking the use of recycled concrete aggregate to produce structural concrete as a case study.