Field Studies on Expansive Soil Stabilization with Nanomaterials and Lime for Flexible Pavement

The long-term performance of pavement is greatly influenced by the subgrade soil-bearing capacity. The areas with lower bearing capability experience higher construction costs due to soil replacement. Soil stabilization is one of the engineering measures that may be used to improve soil properties. The improvement in the soil properties varies depending on the soil type and type and dosage of the stabilizer. The primary objective of this study is to determine the impact of the different types of stabilizers on different types of black cotton soil. In the present study, black cotton soil was treated with Terrasil (0.5, 0.75, and 1 kg/m3), Zycobond (0.5, 0.75, and 1 kg/m3), and lime (0, 2, and 3%). The influence of varying dosages of Terrasil, Zycobond, and lime showed a significant improvement in the FSI, CBR, and UCS. In this study, attempts were made to investigate the field performance of chemically treated black cotton soil. A 100 m trail section with chemical- and lime-treated subgrade was constructed and analyzed using the dynamic cone penetration test. Finally, the mechanical design indicated that the chemical stabilization layer could be helpful to reduce asphalt layer thickness by 30 mm and cost. It is anticipated that this study will be useful to perceive, visualize, and understand the advantages of chemically treated black cotton soil. Overall, it is a step toward sustainable construction, which will reduce the demand for natural materials by optimizing pavement design and the use of existing unsuitable materials (black cotton soil) in flexible pavement construction.