Effect of bauxite residue inclusion on the strength, shrinkage, and abrasion of alkali-activated slag concrete

The objective of this study was to evaluate the effect of two temperature ranges, 50–250 °C and 600–750 °C, in thermogravimetric analysis (TGA) on the compressive strength and drying shrinkage of alkali-activated slag-red mud (AASR). The abrasion resistance of AASR concrete as a function of shrinkage and compressive strength was also investigated. This was accomplished by substituting five different proportions of slag (0, 10, 20, 30, and 40 wt%) with red mud (RM). The results demonstrated that the mass loss between 50 and 250 °C was directly related to the compressive strength and ultimate shrinkage. In contrast, the early-age drying shrinkage strongly correlated with the mass loss at 600–750 °C. Additionally, the AAS abrasion resistance of AASR concrete was further influenced by early-age drying shrinkage than by compressive strength. Moreover, when the RM content was increased to 20%, the abrasion resistance of AASR did not change significantly, whereas a higher level of RM caused a substantial decrease in abrasion resistance. The VIKOR method suggested various optimal contents for RM based on the results of all experiments and the importance of the energy required to produce AASR concrete.