Analisis Substitusi Abu Ampas Tebu dan Garam terhadap Karakteristik Mekanis pada Stabilitas Tanah Laterit

Abstract

Soil stabilization is a technique commonly applied in construction projects to improve soil strength so that it can adequately support structural loads. In this study, lateritic soil was stabilized using additives in the form of sugarcane bagasse ash (SBA) and coarse salt. A quantitative research approach was employed through a series of laboratory tests. The mixture composition consisted of 3% SBA, while the coarse salt content was varied at 4%, 8%, 12%, 16%, and 20%. The California Bearing Ratio (CBR) test results for the natural soil showed values of 15.00% at 2.5 mm penetration and 19.11% at 5.0 mm penetration with 56 blows. After the addition of SBA and salt, the CBR values exhibited fluctuations. The highest CBR values were obtained from the mixture containing 3% SBA and 8% coarse salt with 56 blows, reaching 26.00% at 2.5 mm penetration and 30.22% at 5.0 mm penetration, indicating a significant improvement in soil bearing capacity. In contrast, the lowest CBR values were observed in the mixture of 3% SBA and 12% coarse salt with 25 blows, yielding only 2.40% at 2.5 mm penetration and 2.78% at 5.0 mm penetration, which indicates a substantial reduction in soil strength. The unconfined compressive strength (UCS) test results showed that the natural soil possessed the highest strength, with a maximum value of 5.88 kg/cm². After stabilization, the UCS values generally decreased, although the mixture with 8% salt still produced values close to those of the natural soil. However, increasing the salt content beyond 12% resulted in a significant decline in soil strength.