CO2 Sequestration in Green Porous Concrete Using Red Mud

Achieving carbon neutrality in construction requires materials that balance structural resilience and ecological adaptability. This study explores CO2-cured porous red mud vegetated concrete (RMVC), an innovative solution that repurposes red mud-a nutrient-rich industrial byproduct challenged by high alkalinity-into resilient and sustainable construction materials. Leveraging CO2 mineralization to neutralize alkalinity and enhance material properties, RMVC efficiently and effectively integrates CO2 sequestration into low-carbon functional concrete production. In this study, the effects of different red mud contents (5%, 10%, 20%) and CO2 curing durations (5 h, 10 h, 1 d, 3 d) on RMVC properties are investigated through XRD, TGA, SEM, FT-IR, and microhardness tests. Results reveal that 10% red mud content achieves optimal mechanical strength, balancing hydration and carbonation. Red mud addition regulates pH, accelerates hydration, and enhances carbonation, underscoring its dual role in reducing alkalinity and supporting robust plant growth. This material offers great potential for sustainable, intelligent, and resilient infrastructure.