A Critical Review on Strength Characteristics of Red Mud-Stabilized Black Cotton Soil for Building Foundations in Semi-Arid Zones

This comprehensive review explores the utilization of red mud, a by-product of aluminium production, as a stabilizer for black cotton soil, with a specific focus on its application in building foundations in semi-arid zones. Black cotton soil, known for its high swelling and shrinkage characteristics, poses significant challenges for construction in many parts of the world. Concurrently, the vast quantities of red mud generated by the aluminium industry present environmental concerns. This paper examines the potential synergy between these two problems, offering a sustainable solution for both soil stabilization and industrial waste management. The review synthesizes findings from numerous studies, detailing the chemical composition of red mud and its mechanisms of interaction with black cotton soil. It presents a thorough analysis of the improvements in soil strength characteristics, including enhanced unconfined compressive strength, increased shear strength, improved California Bearing Ratio (CBR), and reduced plasticity index. The influence of key factors such as red mud content, curing time, and moisture conditions on the stabilization effectiveness is critically examined. The paper further explores practical applications through case studies of building foundations and road subgrades in semi-arid regions, demonstrating the real-world viability of this technique. Environmental and economic considerations are carefully weighed, balancing the benefits of waste utilization and improved soil properties against potential risks such as soil alkalinity and heavy metal content.