Experimental Study of Stabilization on Natural Soil Subgrade Using Rice Husk Ash

The objective of this work is to utilize the effectiveness of Rice Husk Ash (RHA) material to enhance the properties of natural soil used for subgrade material in pavement. The quality of a flexible pavement depends on the strength of its sub-grade soil. In view of the above the present investigation has been carried out with rice husk ash mixed individually and also in combination with locally available natural soil in different proportions stepped concentration of 5%, 10%, 15%, 20%, 25% and 30% by dry weight of the soil individually are used to stabilized of Natural Soil (CL) and to evaluate its properties like Grain Size Distribution, LL, PL, PI, OMC, MDD, CBR and Swelling Pressure. The test results indicate that the addition of RHA enhances the percentage of grain size distribution, but with addition of RHA till 10% the LL, PL, PI and swelling pressure decreases, while these parameters further increases in this limit beyond i.e. 10% to 30% of RHA while enhancement is observed above 20% to 30%, Specific Gravity and Maximum Dry Density (MDD) decrease with addition of RHA, for all percentage values, whereas OMC increases in each material. The CBR value increases with the addition of RHA till 10%, while it decreases beyond the limit 10% to 30% with addition of RHA.