Recycling red mud for low-carbon pavement: Performance evaluation and environment risk assessment

This study investigates the use of red mud as a substitute in grouting materials to reduce energy consumption and emissions in semi-flexible pavements (SFP). The pavement performance of SFPs constructed with various alkali-activated grouting materials was experimentally validated and investigated. Life cycle assessment (LCA) highlighted that red mud significantly lowers energy use and environmental impact of SFP. Ecotoxicological assessments confirmed that red mud is safe for use in pavement applications, posing no significant hazards even under traffic and rainfall conditions. Surface treatments for low-carbon SFP were recommended to enhance skid resistance and ecological safety. Microscopic analysis revealed that replacing cement with red mud improves the bonding interface in SFPs. This research validates the potential of recycling solid waste in SFPs, contributing to the development of low-carbon construction materials while addressing environmental impact in pavement engineering.