Compressive strength enhancement of concrete using fly ash as a partial replacement of fine aggregate and model development

The aim of the study is to observe the strength increment of concrete by using fly ash as a partial replacement of fine aggregate. For that, three mix ratios – 1:1.25:2.5, 1:1.5:3 and 1:2:3 (weight-based) have been considered. For each ratio, fly ash was used as 0%, 10%, 20% and 30% of the fine aggregate. The curing period and the water-cement ratio (W/C) were 28 days and 0.5, respectively. It was revealed that the compressive strength of the concrete was increased with the addition of fly ash. And it was the maximum at 10% of fly ash content. A nonlinear relationship has been proposed where compressive strength has been used as the function of the weight of cement, fine aggregate, coarse aggregate and fly ash.