Assessing the effect of partial replacement of cement with fly ash on the strength of concrete in Uganda

Abstract

This report presents the research on the partial replacement of cement with fly ash on the compressive strength of concrete. The aim was to investigate how partial replacement of cement with fly ash affects the compressive strength and workability of the concrete. The British DOE mix design method was utilized in the mix design to select suitable constituent materials and determine proportions of the materials to meet specifications for the concrete required and the concrete produced was subjected to tests that included; Slump and compressive strength. To study the compressive strength, cubes of 150×150×150mm were used. The samples were cured for 7 and 28 days. After curing they were tested on the Universal Compressive Testing Machine. The results showed a satisfying difference in compressive strength since they were some were slightly below of the target strength after the 7 days of curing and on the 28th day of curing. This report recommends the use of fly ash as a substitute of cement in its absence or unsuitability.