ABSTRACT

Controlled burning of rice husks at 6000C gives rice husk ash (RHA) which is properly produced to Pozzolan that is amorphous silica (SiO2) which can be added to cement for building applications. Cement was mixed with laterite in proportion of 10%, 20%, 30%, 40% and 50%. The concrete was cured for 7 to 28 days and also heat resistance was conducted. It was observed that 50% of cement provides the optimum strength with heat resistance of 10000C and above. Pozzolan was mixed with laterite in proportion of 10%, 20%, 30%, 40% and 50%. The concrete was cured for 7 to 28 days and also heat resistance was conducted, and it was observed that 50% of Pozzolan provides the optimum strength with heat resistance of 10000C and above. Pozzolan was also added to cement with laterite in proportion of 10%, 20%, 30%, 40% and 50%. The concrete was cured for 7 to 28 days and also heat resistance was conducted, and it was observed that 20% of Pozzolan added to cement provides the optimum strength with heat resistance of 10000C and above. The effects of different particle sizes of 75, 150, 212, 300, 425 and 600 Microns were tested using a compression test machine, it was indicated that 75 micron provides the optimum strength. Also a graph of average strength against particle size indicated 3.4 Nm-2 as the optimum strength at 75µm and 1.3 Nm-2 as the minimum at 150µm, which underlines the significance of the contribution of particle size to the desired strength. 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. X – ray fluorescence (XRF) analysis was performed to determine the content of various chemical oxides in RHA, which indicated Si, Mn, K, Mg, P, Ca, Ru, Fe, Zn, Mg, Cr, Ti, Ni, Cu, Rb, Sr, Y, Zr, Eu and Ba. X – ray diffraction (XRD) analysis indicated the presence of SiO2 in the sample, which is amorphous silica. The results from this work show that adding Pozzolan to cement improves the strength, quality and quantity of concrete, which can be use for building applications.