rubber-modified self-compacting concrete: mechanical performance and cradle-to-gate life cycle assessment for low-load applications

This study investigates the utilization of recycled tire rubber in self-compacting concrete (scc) as a sustainable construction technology aligned with circular economy principles and climate change mitigation. rubber powder (≤150 µm) replaced limestone powder, and rubber granules substituted fine aggregates at 10%, 20%, and 30% by volume. mechanical testing revealed a 15–25% reduction in compressive and tensile strengths, primarily due to increased porosity and weak interfacial transition zones. however, replacing limestone powder with fine rubber enhanced microstructural densification through a filler effect: the mixture with 30% rubber powder (crlw3) achieved a 28-day compressive strength of 38 mpa. life cycle assessment (lca), conducted using simapro and the ecoinvent 3.8 database, demonstrated a 45% reduction in co₂ emissions and global warming potential, along with 56% and 40% decreases in acidification and eutrophication potentials, respectively. these results indicate that rubberized scc, particularly with fine rubber powder, offers a viable and environmentally beneficial alternative for non-structural applications such as pavement base layers, lightweight concrete blocks, and noise-absorbing barriers, where ecological advantages outweigh the need for high mechanical performance.