Controlled burning of rice husks at<700°C produced rice husk ash (RHA) which is predominantly amorphous silica (SiO2). RHA was used as a substitute for laterite and cement in proportions of 5%, 10%, 15%, 20%, 25% and 30% of concrete. The concrete was cured for 7 days, 14 days, 21 days, and 28 days respectively. It was observed that 20% of RHA provides the optimum strength. The effects of different particle sizes of 75, 150, 212, 300, 425 and 600 microns (µm) were tested using a compression test machine. A graph of average strength against particle size indicates 2.9 Nm-2 as the optimum strength at 75 µm and 1.2 Nm-2 as the minimum at 150 µm. From the ash size distribution, the presence of grains of several different sizes was observed. The grains were weighed using a weighing machine and a graph of particle size against percentage plotted to determine the particle size distribution. This showed that rice husk ash (RHA) is coarse grain material.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.