Effect of Addition of Red Brick Powder and Salt on CBR Value in Clay Soil Stability

Soil acts as the main support in building construction, including foundations. The type of clay soil that has high cohesion and plasticity properties often causes damage to building structures. This happened to the tourism development in Sampih Village, which experienced cracks in the walls and foundations due to the clay subgrade. This research aims to improve the quality of the soil with a stabilization method using a mixture of red brick powder and salt, which was tested using the California Bearing Ratio (CBR) method. Tests were conducted in the laboratory with a variety of mixtures: 10% salt; 10% red brick powder (SBM); 5% salt + 10% SBM; 10% salt + 5% SBM; 5% salt + 5% SBM; and 10% salt + 10% SBM. The test results show that the CBR value of the original soil is about 9.4% (CBR without soaking), which belongs to the low bearing capacity category. After stabilization, the 5% salt + 10% red brick powder mixture variation gave an increase in CBR value up to 24.10%, higher than the other variations. The study implies that the combination of salt and red brick powder can significantly increase the bearing capacity of the soil, which has implications for improving foundation stability for construction in areas with clay soils.