Improvement of Expansive Soils Stabilized with Rice Husk Ash (RHA)

This study aims to stabilize expansive soil with RHA by 0%, 3%, 6% and 9%. The index properties test with existing soil included lean clay (CL). The existing soil was repaired by adding stabilizing material in the form of RHA as an added material. Based on the specific gravity test, it can be concluded that the addition of RHA reduced the value of specific gravity, made the plastic limit (PL), liquid limit (LL) and plasticity index (IP) decrease, which means that it could improve the properties of the existing physical soil. Standard Proctor Compaction Test (SPCT) with unsoaked method was conducted by giving 3 different number of blows, i.e. 10, 25, and 56 blows in 3 layers. The results show that the optimum moisture content (OMC) was almost constant, while the maximum dry density (MDD) slightly increased and most were added to an additional 6% of RHA. CBR test results show that the existing soil was 0.053 and after adding RHA, increased to 130% in the addition of 6% of RHA.