Red mud as a sustainable road construction material: An experimental investigation

Abstract

In response to the pressing need for environmentally responsible waste management, this research delves into the potential applications of bauxite residue, commonly called red mud, a by-product of the Bayer process employed in aluminum extraction, within concrete-based applications. This study explores the viability of utilizing red mud to prepare construction materials for highway infrastructure. Characterization of the red mud unveiled that it poses no hazardous concerns, establishing its safety for further application. The experimental phase of the research involved the development of six distinct concrete mixtures, including a control mixture with varying proportions of red mud. Notably, including red mud, they had no adverse impact on the fresh concrete properties, with all values well within acceptable ranges. Furthermore, comprehensive microstructural analyses and leaching tests confirmed that concrete incorporating red mud adheres to safety and toxicity standards, assuaging environmental concerns. Regarding mechanical properties, laboratory tests showcased significant improvements, including a notable 14.01% increase in compressive strength, a robust 6.74% boost in flexural strength, and a 7.58% enhancement in split tensile strength following a 28-day curing period. The culmination of these findings underscores the feasibility of integrating red mud as a partial substitute for cement, up to 15%, in the construction of rigid pavement for highway applications. This approach tackles sustainable waste management and fosters eco-friendly construction materials, especially for highway projects.