Development of environmental-friendly and cost-effective recycled plastic fiber reinforced recycled aggregate SCC

This study addressed the disposal of waste concrete and plastic, industrial waste by employing an environmental-friendly and cost-effective method. A sustainable self-compacting concrete (SCC) was manufactured by recycling waste concrete, industrial waste, and waste plastic. An in-depth insight into the advantages of the combined addition of waste plastic fiber (WPF), recycled coarse aggregate (RCA) and supplementary cementitious materials (SCMs) on the mechanical properties, environmental impact and economic cost of SCC was presented in this paper. 10 WPF reinforced recycled aggregate SCC (WPF-RA-SCC) mixtures were prepared by substantially replacing natural aggregates and cement with RCAs and SCMs, respectively. The compressive strength and elastic modulus of WPF-RA-SCC mixes were evaluated as well as the combined effect of WPF and SCMs. A formula was proposed to predict the elastic modulus of WPF-RA-SCC. The environmental impacts and economic cost of WPF-RA-SCC were quantified using Life cycle assessment and life cycle cost analysis. A novel Multi-criteria Decision Analysis (MCDA) methodology for WPF-RA-SCC was proposed to identify the optimal mixture by integrating fresh and hardened properties, environmental and economic performance. The research findings indicate that combined effect WPF and SCMs significantly enhanced the compressive strength and elastic modulus of RA-SCC. Additionally, the combined addition of RCAs, SCMs and WPF offered considerable advantages on environmental and economic performance, by reducing the environmental load and economic cost up to 73.9% and 34.7%, respectively. Quaternary RA-SCC comprising 1.0% WPF and 75% SCMs using a combination type was recognized by the MCDA as the optimized mix, which exhibited superior mechanical properties, low environmental impacts and economic cost. This study proposed a novel approach for prioritizing sustainable materials selection, thus facilitating the recycling of waste concrete, waste plastic and industrial by-products.