Replacement of Sand with Bauxite Mining Waste in Concrete Production

The use of natural sand as fine aggregate in concrete is becoming problematic due to scarcity and pressure on mining of the resource. Alternate sources such as the use of industrial waste as replacement of natural sand in concrete are gaining popularity as a sustainable construction material. The aim of this study is to examine the possibility of using bauxite mining waste as a fine aggregate replacement for concrete production. The quantities of sand replaced with bauxite mining waste used are 0, 25, 50, 75 and 100%. Cube, cylinder and beam specimens were molded and cured for 7, 14, 21 and 28 days, and tested for density, compressive strength, tensile splitting strength and flexural strength. The study found that there was a slight increase in density of bauxite mining waste produced concrete over the control as the quantity of bauxite residue increased. The study further revealed a significant increase in compressive, tensile splitting and flexural strengths of the concrete produced with bauxite residue as compared with the control, with an increase between 60.3 and 65.5%. Additionally, a good correlation was established between the bauxite contents and the density of concrete produced with bauxite mining waste, recording R2 values between 0.9749 and 0.9896. The 100% bauxite residue replacement of sand obtained the highest strength properties in the concrete. The study, therefore, concludes that it is feasible to use bauxite mining waste as a fine aggregate replacement in concrete production. It is recommended that further studies should be conducted on the durability and chemical properties of concrete produced with bauxite mining waste as the current study only focused on the strength properties