Lifecycle Assessment and Lifecycle Cost Analysis of Sustainable Concrete Incorporating Recycled Aggregates

In recent decades, the construction industry in China has experienced significant growth, leading to substantial consumption of non-renewable natural resources and a large amount of construction and demolition waste (CDW). As a result, the effective utilization of CDW has become critically important in China. This study focuses on the processing of CDW to produce recycled fine aggregates (RFAs) and recycled coarse aggregates (RCAs), which were subsequently used to produce recycled aggregate concrete (RAC). A total of 12 RAC composites incorporating RFAs and RCAs were prepared, and their compressive strength was evaluated in detail. The life cycle assessment (LCA) methodology was employed to assess the environmental impact of 1 m3 of RAC within a “cradle-to-gate” system boundary. Furthermore, the life cycle cost analysis (LCCA) method was applied to evaluate the economic benefits of RAC. The contributions of RCAs and RFAs were analyzed in detail. Lastly, multi-criteria decision analysis (MCDA) using the Data Envelopment Analysis (DEA) approach was proposed to comprehensively compare the environmental and economic impacts of RAC and ordinary concrete. The results of the LCA and LCCA indicate that the inclusion of RCAs and RFAs in composite mixtures leads to significant environmental and economic benefits. The MCDA identified the optimized RAC mixture as one containing 70% RCA and 100% RFA, which demonstrated the best performance in terms of mechanical properties, environmental impact, and economic cost. The composite addition of RCA and RFA in RAC production can significantly reduce both environmental impacts and economic costs, thereby enhancing the sustainability of the concrete industry.