Production of Environmentally Friendly Concrete Incorporating Bauxite Residue and Silica Fume

Toward a sustainable approach, concrete consumption is confronted with new challenges to developing and implementing cleaner technology. Concrete production is associated with excessive use of natural resources along with environmental pollution, which can be partially addressed through cement replacement with industrial waste. Red mud (RM), a toxic by-product of alumina refineries, is a potential supplementary cementitious material that has attracted researchers’ attention in the last years. In this study, 10 mixes were prepared and tested to investigate the simultaneous application of RM (10%, 15%, and 20%) and silica fume (SF) (5% and 7.5%) as cement replacement on concrete properties. The properties of fresh and hardened concrete and its durability were investigated. Overall, the mechanical performance of mixes decreased by increasing RM incorporation, whereas the simultaneous application of 20% RM and 5% SF as cement replacement yielded the same compressive strength as the reference. Furthermore, an evaluation of global warming potential and used water as environmental impacts in addition to a simplified cost analysis was performed on all mixes. Overall, the mix made with 10% RM and 7.5% SF achieved the highest consolidated performance score.