Environmental and economic effect assessment of low-carbon high performance recycled aggregate concrete based on life cycle assessment （LCA）

The popularization and application of low-carbon high performance recycled aggregate concrete （LC-HPRAC） prepared from industrial waste residue and building recycled concrete aggregate align with the requirements of China's Double Carbon Goals. Based on the life cycle assessment （LCA） method， the environmental and economic effect of LC-HPRAC with various steel fiber （SF） contents and recycled aggregate （RA） replacement rates were quantified， and a range analysis and factorial method was used to analyze the significance of each index， with the mechanical properties， environmental impact and economy of LC-HPRAC materials taken into consideration comprehensively. The results showed that the carbon emission of Portland cement-based plain concrete was 426 kg CO2-eq/m3， and the carbon emission of LC-HPRAC was only 42% of that of plain concrete. The environmental impact of LC-HPRAC mainly came from alkali-activator， steel fiber and slag in the raw material production stage， accounting for more than 60% totally. The environmental impact of LC-HPRAC was mainly attributed to the Global Warming Potential， accounting for over 45%， among which， the carbon emission was the main factor. The environmental and economic comprehensive impact indexes of LC-HPRAC were generally positively correlated with the recycled aggregate replacement rate and steel fiber content. When the steel fiber content was 0.5% and recycled aggregate replacement rate was 50%， the environmental and economic comprehensive effect of LC-HPRAC were optimal.