An experimental study on cement concrete with industrial fly ash and Phosphogypsum

Abstract

Industrial Flyash (IFA) is a fine powder made from non-combustible materials and a residue of carbon from incomplete combustion. Phosphogypsum (PG) is also a solid by product of phosphoric acid processing, which is employed in a variety of fertilisers and chemicals. Traditional construction material manufacturing processes destroy the earth's vital natural resources. Furthermore, IFA and PG is a solid waste, which is frequently dumped in open spaces. IFA and PG contains natural mineral which can be used as admixture in concrete. It can be used as partial replacement to the cement in the concrete up to certain limit. The experimental findings include compressive strength (CS), flexural strength (FS) and split tensile strength (STS) by partially cement replacement with Industrial IFA and PG employing 0 %, 5 %, 7.5 %, 10 %, 12.5 %, 15 %, and 20 % on M40 grade concrete and water-binder ratios of 0.45. The CS is determined by testing cube specimens for 7 and 28 days, as well as FS and STS is found by testing the beams and cylinders specimens for 7 and 28 days respectively. The optimal proportion shows maximum strength at 15 % IFA and 7.5 % PG respectively. Further increase in percentage, strength of concrete decline marginally. 10 % substitution of cement with IFA + PG (combined 50 % each) used shows the optimal proportion to achieve maximum strength, and further increase in IFA and PG causes a decrease in strength. The addition of IFA and PG increases the amount of water required due to increase in fine particles or a bigger surface area. When compared to the control mix, the workability of concrete with IFA and PG reduces slump value by up to 15 %.44Corresponding Author: E-mail address: sandeepsatheresearch@gmail.com (Sandeep Sathe)