Assessing recycled concrete’s sustainability with emergy theory and input–output modeling

This study is the first to integrate emergy theory, life cycle assessment (LCA), and input-output analysis (IOA) to analyze the environmental performance of conventional concrete (CC), recycled coarse aggregate concrete (RAC), recycled fine aggregate concrete (RFC), and recycled powder concrete (RPC). It comprehensively covers the entire life cycle from raw material extraction to waste disposal, employing dynamic emergy flowcharts to visually represent emergy inputs and pollutant emissions at each stage. By introducing an emergy-based input-output emission coefficient, this study standardizes environmental impact assessments across different material flows, enhancing both accuracy and comparability. The findings reveal that recycled concrete significantly reduces emergy consumption and pollutant emissions, especially in cement production, where its reduction potential is most pronounced. Additionally, the findings highlight recycled concrete’s ability to enhance resource efficiency and minimize environmental degradation. This study contributes an innovative emergy-input-output evaluation framework based on Cradle to Cradle (C2C) principles, providing valuable insights for optimizing and selecting sustainable building materials to promote a circular construction economy.