Comparative assessment of GHG emissions from end-of-life scenarios for waste prestressed concrete railway sleeper in Korea

This study conducted a comparative life cycle assessment (LCA) of three end-of-life scenarios for prestressed concrete railway sleepers (PCRS): landfilling without recycling (S1), recycled concrete aggregate (RCA) recycling (S2), and CO₂ capturing material reprocessing (S3). The system boundary and functional unit were defined in accordance with EN 15,804, and greenhouse gas (GHG) emissions were evaluated using the IPCC 2021 GWP (100-year) method. An avoided burden approach was applied to reflect the environmental benefits of material substitution and CO₂ capture. The results indicate that S2 and S3 achieved net carbon offsets of 44,416 kgCO₂eq and 95,371 kgCO₂eq, respectively, relative to the baseline scenario (S1). These environmental benefits were primarily attributed to the avoided emissions from virgin material substitution and direct CO₂ removal. The study highlights the importance of on-site separation technologies for maximizing resource recovery and provides a circular solution for decarbonizing infrastructure waste management systems.