Effect of Lakhra Fly Ash as Partial Replacement of Cement in Traditional Concrete

Abstract

This study was aimed to determine the effect of LFA (Lakhra Fly Ash) as partial replacement of cement in concrete. To conduct this study, a total of 72 standard concrete cylinders were cast with 1:2:4 proportions at 0.5 water-binder ratios. Cement was partially replaced by weight with LFA and the percentage replacements of FA (Fly Ash) were kept as 0, 5, 15, 25, 40 and 50%. In addition to that, workability of each mix was determined by Slump Cone test and Compaction Factor test. Out of 72 cylinders, 36 cylinders were tested to determine the compressive strength while the remaining 36 cylinders were tested to determine the tensile strength of concrete, at 7 days curing period, by using UTM (Universal Testing Machine). The results revealed that 25% replacement of binder with LFA, determined an increase in compressive strength of concrete up to 15% as compared to normal cement concrete. Moreover, the tensile strength of concrete also increased up to 16% for the same percentage replacement. Furthermore, it also increased the workability, cohesiveness and surface finishes of concrete. This finding can help to reduce the admixture dosage or the water content of the mix. On the contrary, the compressive strength as well as the tensile strength of concrete decreased in case of 40 and 50% replacements of the cement with FA.