Study the hydration and the microstructure of cement blended with rice husk ash in comparison with silica fume

Abstract

Rice husk ask (RHA) is not a ultra-fine material as silica fume (SF), but possesses a very high specific surface area because of its porous structure. With the similar chemical composition of RHA and SF, the activity of RHA, therefore, is different from that of SF. The objective of this work is to study the hydration and the microstructure of Portland cement blended with RHA in comparison with SF. The test results show that SF refined the pore structure of cement paste better than RHA. However, the effect of RHA on cement hydration is more pronounced than that of SF for the mixture with low water to binder ratio.