Use of natural pozzolanic material as partial replacement Ordinary Portland Cement (OPC) in concrete

Fly ash is a powder material of burned coal from thermal power stations which produces cementitious and pozzolanic material. Commonly use of fly ash in concrete for building construction contributes conducive environmental and also reduces the effect of pollutant in site project. Therefore, this study was conducted to investigate the use of fly ash as partial replacement of cement in concrete as a mean of producing more environmental friendly concrete. The content of fly ash as partial replacement of ordinary portland cement(OPC) is investigated by weight accordingly in range 0%(without fly ash), 10%, 20% and 30% for grade 25. The chemical composition of fly ash was determine using X-ray Fluorescence (XRF). The scanning electron microscope (SEM) was used to determine particle size, shape and texture of fly ash. The mix proportion of concrete was determine using mix design method according to British Standard. The workability of the fresh concrete mixture was evaluated using slump test while compressive strength of cubes concrete was evaluated at 7, 14, 28 and 56 days. A total of 48 cubes concrete with size 100mmx100mmx100mm were made. The optimum compressive strength at all ages of testing was obtained at 10% replacement. Workability decreased with an increased in replacement percentage of fly ash. The results therefore show that fly ash as pozzolanic materials can be used to partially replace ordinary portland cement in production of concrete