BIM-integrated life cycle assessment of decentralized cement-based waste recycling in renovation projects.

Decentralized community recycling offers a sustainable pathway for managing 100% cement-based waste (CBW) from renovation activities, providing a viable alternative to centralized recycling facilities and landfilling. This study employs an integrated BIM-Life Cycle Assessment (LCA) framework to evaluate the use of recycled concrete aggregate as a substitute for natural aggregates in non-structural concrete. The CBW was dismantled, segregated, crushed, and graded to produce RCA. Thirty-six specimens were prepared in three mixes: CBW0 (100% NA), CBW1 (100% coarse RCA + 50% fine RCA, Styrene butadiene rubber/Water (SBR/W) = 1:25), and CBW2 (100% coarse RCA + 50% fine RCA, SBR/W = 1:50). A cradle-to-site LCA (A1-A4), following the EN 15,804 + A2 (adapted) baseline, quantified the environmental impacts of 1 m3 of concrete. Relative to conventional concrete (CC), CBW2 achieved the target for grade 20 concrete, reaching 16 MPa after 28 days while reducing overall environmental impacts by 29%. Phase-specific savings reached 23.4% (A1-A3) and 75% (A4). These outcomes demonstrate the potential of decentralized recycling and BIM-LCA integration to balance mechanical performance with environmental efficiency in sustainable construction.