<![CDATA[Expansive soil from Pulorejo Village, Purwodadi District, Grobogan Regency, Central Java, exhibits high plasticity and relatively low bearing capacity, requiring stabilization before use as pavement subgrade. This study evaluated the effects of lime, rice husk ash, and their combination at 2.5%, 5%, 7.5%, and 10% on soil plasticity, compaction, and California Bearing Ratio (CBR). Laboratory testing included Atterberg limits, Modified Proctor, and CBR tests. The natural soil had a Liquid Limit of 74.02%, Plastic Limit of 32.22%, Plasticity Index of 41.80%, and CBR of 5.8%. Stabilization reduced plasticity and modified compaction characteristics. Lime increased the maximum CBR to 17.2% at 10%, while rice husk ash increased it to 15.8% at 10%. The combined lime–rice husk ash treatment produced the highest CBR of 18.5% at the 10% variation. These results indicate that the combined stabilizer provided the most effective improvement in bearing performance and offers a technically promising approach for improving expansive subgrade soil while utilizing agricultural waste as a supplementary stabilization material. The findings support sustainable soil improvement strategies for road construction in areas characterized by highly plastic expansive soils.]]>
Copyrights © 2026
