The use of bauxite mining waste as fine aggregate replacement for concrete production

Abstract

Conventional construction materials require the extraction of large quantities, causing depletion of natural resources and environmental damage. This work investigates the possibility of using bauxite mining waste as fine aggregate replacement for concrete production. The experimental works were conducted by varying sand and bauxite mining waste to mix ratio of 1:2:4 with five different replacement levels namely: 0%, 25%, 50%, 75% and 100% by weight and water cement ratio of 0.60. A total of sixty (60) cubes of size 150mm x 150mm x150mm, sixty (60) cylinders having diameter of 150mm and height of 300mm and sixty (60) beams of size 150 mm x 150 mm x 450 mm were cast and tested in 7days, 14 days, 21 days and 28 days respectively. Tests conducted include workability, density, compressive strength, tensile strength and flexural strength. It was found that the bauxite mining waste composite mix was less workable to control mix. It was found that the density of the bauxite mining waste produce achieved slightly higher results as the quantity of bauxite mining waste increased, there was no statistical significant difference among concrete produced. It was also found that the compressive strength, tensile strength and flexural strength achieved good results as the quantity of bauxite mining waste increased, there was statistical significant difference in the various mix proportions as the quantity of bauxite mining waste increased. It was also found that there was positive correlation between the density of the concrete produced and the compressive strength, tensile strength and flexural strength. It is recommended that bauxite mining wastes are suitable to use as fine aggregate replacement for concrete production in the areas where the bauxite residues are deposited.