DefinePK

Abstract

This research study aimed at finding the percentage utilization of fly ash and marble dust by replacing cement and sand respectively, in concrete so that significant results for strength and durability may be achieved. Therefore, fly ash and marble dust were incorporated in cement mortars in different proportions to determine the best performance sample based on the compressive strength tests. As a result, the replaced sample with 30% fly ash and 25% marble dust resulted in the highest compressive strength values. This combination was then selected for preparing concrete samples and thereafter conducting various laboratory tests such as compressive strength, split-tensile strength, and sorption test up to the 90th day. The results showed that the replaced sample gave lower strength results up to the 28th day as compared to the control group. However, an increase in strength values was observed on the 56th and 90th days. This is because after substantial hydration of cement, fly ash starts reactions with calcium hydroxide which is obtained as a byproduct of hydration reaction. The fly ash reactivity with calcium hydroxide gives CSH and CAH gel which results in a dense and strong structure. Moreover, the finer marble dust particles also contribute towards dense particle packing. In addition, the density and compressive strength relationship shows better agreement with the R2 value of 0.966.