Mechanical performance of recycled aggregate concrete in green civil engineering: Review

The use of recycled aggregate concrete can save natural resources and reduce environmental pollution, which has been widely concerned in recent years. The physical and mechanical properties of recycled aggregate concrete (RAC) are studied based on the literature on waste concrete coarse aggregate (RCCA) and waste brick coarse aggregate (RBCA) published around the world in the last 40 years, in order to understand and study the performance of common RAC. The common characteristics (water absorption, density, and crushing value) of two recycled aggregates with the same particle size were compared. The effects of effective water-cement ratio (e-W/C), aggregate cement ratio (A/C), and recycled aggregate content on the compressive properties of recycled concrete are explained, and the microstructure of recycled concrete is explored. The influence of recycled aggregate content on its elastic modulus (Ec) and the correlation between Ec and the compressive strength of recycled concrete are also investigated. Finally, prospects were made for two types of RAC for further research by scholars.