Strength Aspects of Fly Ash in Cement Mortar

Abstract

The aim of the investigation was to evaluate the feasibility of mixing fly ash in cement to make mortar specimens for getting an agreeable compressive Strength of the mortar. Different proportions of cement and fly ash were tried at laboratory-scale, utilizing dry fly ash at 15%, 20%, 25%, 30%, 35%, 40%, 45% and 50% of cement-weight. The reference mortar was prepared with 100% of Ordinary Portland Cement (OPC). The blended mortar was utilized to make standard cubes of uniform size, namely, 70.6mm (L), 70.6 mm (W) and 70.6 mm (H). After curing at standard temperature and humidity, being soaked in potable water, tests were carried out, for evaluating the compressive strengths attained by the cube specimens, at the curing ages of 3, 7, 14, 21 and 28 days. The 28th day’s compressive strength of the cement-fly-ash-mortar containing 70% cement and 30 % fly ash was 37.53N/sq.mm, which corresponded to 93.7% of the Compressive strength(40.06N/sq.mm) attained by the reference mortar which contained 100.0 % of cement. and zero percent It was inferred that fly ash can be added at 30% weight of cement in the mortar, on dry weight basis.

Keywords: Cement, Mortar, Fly Ash, Test on Compressive Strength, Optimum Ratio