THE DURABILITY OF LIME AND RICE HUSK ASH IMPROVED EXPANSIVE SOIL

Rice husk is as waste farm material in Indonesia used as fuel for making bricks and similar materials. Rice husk ash (RHA), a combustion product that wasted previously, currently being investigated for use as a mixture of cement or soil stabilization material. This study aims to investigate the mixture of lime and RHA as a stabilizing agent. Due to minor contains of calcium in RHA, its utilization for stabilization materials needs to be combined with lime that can increase the stability of expansive soils and shorten the curing time as well since it is needed for binding of molecules from soil minerals. By determining the optimum mixture of 4% lime and 6% RHA expressed as the ratio of the dry weight of the material, it was found that the CBR of stabilized soil is greater than that of natural soil, a mixture of expansive soil with lime and expansive soil with RHA itself. The dry wet cycle is assumed as a change that occurs in the environment due to the season. The amount of water absorption which is indicated by an increase in weight and volume of soil shows the durability of additive to environment changes and have an effect on strength and swell potential of expansive soils.