Effect of Partial Replacement of Sand by Coal Bottom Ash in Concrete

Abstract

The manufacture of cementitious composite involves the depletion of numerous natural resources, like clay, sand and limestone. This study aims to partially replace sand with concrete. Three types of specimens were prepared to contain 3%, 5%, and 10% partial replacement of sand by coal bottom ash, obtained from Lakhra Coal power plant in Sindh province of Pakistan. Initially, the XRF results showed that the coal bottom ash is not pozzolanic and can be used as filler material in the cementitious composite. Workability, density, compressive and tensile strengths were determined using ASTM standard methods and the results were compared with those of the control specimen. The mechanical tests were performed on the third, seventh, and twenty-eighth day of concrete age. The results show reduced workability and density and increased strength at the age of maturity. It is concluded that the partial replacement of the sand with the coal bottom ash is a feasible solution, leading to the eco-friendly recycling of hazardous industrial waste products.