Investigation of Rice Husk Ash (RHA) as a Supplement in Cement for Building Applications

An investigation of Rice husk ash Pozzolan as a supplement in cement for building applications was carried out. A controlled burning of rice husk ash (RHA) at 5000C produced amorphous Silica (SiO2). The rice husk ash (RHA) was substituted for cement in proportions of 0%, 5%, 10%, 20% and 30% of concrete. The concrete was cured for 7 days, 14 days, 21 days and 28 days respectively. It was observed that 20% replacement of Rice husk ash (RHA) provides the optimum strength. Comparison of mixtures with particle sizes of 600 microns, 425 microns, 300 microns, 212 microns, 150 microns and 75 microns, showed that 75 microns provide the optimum strength. X-ray fluorescence (XRF) analysis was performed to determine the content of various chemical oxides in RHA, which indicated that Mg 0.9%, Si 81.8%, P 5.48%, K 3.19%, Ca 1.80%, Mn 0.417%, Fe 0.782%, Zn 0.140% and Ru 0.270%. X-ray diffraction (XRD) analysis to determine low crystallinity of the samples showed the peak value at 26.66 known to be the quartz primary.