Clayshale stabilization using active natural lime to increase the shear strength of soil

Clayshale not used in construction because it is easily weathered when exposed to air and water to reduce the soil shear strength. As a result, this decline can cause geotechnical engineering problems, and clayshale needs stabilization. This study aims to determine the shear strength of clayshale by adding variations of 5%, 8%, and 11% lime. Tests carried out to obtain soil parameters include soil index and engineering properties. Based on laboratory tests, the original clayshale soil has a 33.2% liquid limit, a 6,1% plasticity limit, and a 27,1% plasticity index. Hence, clayshale soils belong to the CL(clay-low plasticity) category based on the USCS. Adding lime variations can increase the specific gravity and the optimum moisture content of the clayshale soils. Still, it can reduce the dry unit weight and the plasticity index value on clayshale soils. The triaxial test on the original clayshale soil sample obtained a cohesion(c) value of 0.20kg/cm 2 and friction angle(f) of 6.38°. In contrast, the values of c and f occurred the highest increase from the original clayshale soil with the addition of 8% lime, so lime can be used as an alternative in soil stabilization because it can increase the shear strength of the soil.