Rice husk ash burnt in simple conditions for soil stabilization

Rice hush ash (RHA) is a pozzolanic material and can be used in the lime treatment for soil stabilization without strict requirements of burning conditions. In this study, 3 samples of RHA collected from burning rice husk and 1 sample from burning rice husk firewood were considered. Their reactivity was identified in experiments with saturated lime solution. The results showed that they are classified as none to variable pozzolanicity. To evaluate their effect on the lime treatment on clayed soil, two sets of experiments were performed. The first set used 3 samples including the one from rice husk firewood and mixed with lime in the ratio of 1:1. The second set used the other sample combined with coal slag and lime. The results show that replacing partly the lime by RHA can give the same or even higher shear strength than that of using only lime, despite the results of low activity. Therefore, using RHA from simple burning conditions for soil stabilization is an effective and economical option.