Enhancement of Engineering Properties of Black Cotton Soil Using rice husk and sawdust ash

The weak engineering properties of black cotton soil can cause instability and failure of structures built upon it. Thus, the improvement of its properties is of utmost importance. The present research is to investigate the effect of integrating sawdust ash and rice husk ash on the engineering features of black cotton soil. The soil samples were collected from Guntur KL University, Andhra Pradesh, at a depth of 1-2 meters. Rice husk ash was added to the soil in varied percentages of 0, 3, 6, 9, 12, and 15% by weight of black cotton soil, whereas sawdust ash was added to all mixed samples at 6% by weight of soil. To analyze the engineering properties of the soil and its mixtures, laboratory tests such as Atterberg’s Limits, Specific Gravity, Particle Size Distribution, Standard Proctor test, Unconfined Compressive Strength (UCS), and California Bearing Ratio (CBR) were performed. Results showed that adding a combination of 9% Rice husk and 6% sawdust ash to the weight of black cotton soil notably improves its engineering properties. Therefore, sawdust and rice husk ash have the potential as soil stabilizing agents, making black cotton soil a more suitable foundation material for construction