Multi-dimensional life cycle assessment of a typical recycled aggregate concrete production facility in China

The focus of this study was on a life cycle assessment (LCA) of a concrete production facility manufacturing both natural aggregate concrete (NAC) and recycled aggregate concrete (RAC), with the recycled aggregates (RAs) sourced from construction and demolition waste. A comprehensive evaluation using LCA was established, addressing four dimensions: environmental load, compressive strength, service life and economic cost. The functional unit for the analysis was defined as 1 m3 C20, C25 and C30 strength grade concretes from factory delivery to a specific affordable housing project. The environmental loads of the NAC and RAC was compared. The results showed that cement is the primary contributor to environmental load. Notably, incorporating RAs significantly reduced the environmental load. At a 50% replacement ratio of natural aggregates with RAs, the environmental load for the aggregate stage of C20 concrete achieved a net environmental benefit of −1.46 × 10−14. Several multi-dimensional indicators were introduced. Considering economic cost, service life and compressive strength, the 28-day cost-weighted annual average environmental load-to-compressive strength ratios of C20, C25 and C30 concrete with 50% RA decreased by 21.2%, 14.8%, and 14.5%, respectively.