Production of high strength concrete incorporating an agricultural waste - rice husk ash

Rice husk which is an agricultural waste, constitutes about one-fifth of the 500 million tonnes of rice produced annually worldwide. Normally, the residue is disposed off by burning at the mill sites and the resultant rice husk ash (RHA) is dumped on a waste land. This generates environmental, pollution and land dereliction problems. Under controlled burning and if sufficiently ground, the highly reactive ash that is produced can be used as a supplementary cementing material or in the production of high strength concrete (HSC). This paper shows that it is relatively easy to produce high strength Grade 80 concrete incorporating RHA. Data on the strength property and durability showed that RHA concrete is just as good as that of silica fume. The potential of RHA as an alternative material to produce cheaper HSC is highlighted in this paper and should be exploited by the rice and construction industries.