An eco-friendly solution for construction and demolition waste: Recycled coarse aggregate with CO2 utilization

Carbonation of recycled coarse aggregate (RCA) is an eco-friendly solution for the recycling of construction and demolition waste. This paper provides a comprehensive understanding of utilizing CO2 in RCA. The carbonation mechanism associated with CO2 treatment of RCA has been systematically summarized. The methods for CO2 treatment of RCA and the calculation of CO2 sequestration were discussed. Meanwhile, the efficiency of physical properties enhancement of carbonized RCA was analyzed. The microstructure, mechanical properties and durability improvement of recycled concrete containing carbonized RCA were reviewed. Additionally, the environmental benefits of carbonized RCA were provided through carbon footprint, carbon accounting and carbon intensity. Furthermore, the future perspectives of RCA with CO2 utilization were prospected. [Display omitted] •Carbonation of RCA consists of Ca2+ extraction, CO2 dissolution and CaCO3 formation.•The carbonation reaction greatly improves the physical properties of RCA.•Provide an assessment method of environmental benefits for carbonized RCA.•Carbonized RCA offers an eco-friendly solution for C&D waste.