Influence of Terrazyme on Moderately Expansive Black Cotton Soil

Black cotton soil has always posed serious problem to the infrastructures because of its swelling and shrinkage characteristics in the presence and absence of water. Light structures in rural areas of tropical India, especially in the states of Maharashtra, Karnataka, and Andhra Pradesh, suffer considerable swell–shrink characteristics. It is always challenging for engineers to build structures that can resist the problems created by black cotton soil and to make the structures functionally stable and durable. In this paper, an attempt is made to establish that Terrazyme treated black cotton soil performs better than untreated soil. For this purpose, locally available moderately expansive black cotton soil obtained from within the city of Mysore was studied for its performance with and without the inclusion of Terrazyme. The soil was tested for its index properties, compaction characteristics, unconfined confined compression strength, and permeability characteristics. Terrazyme, a non-toxic, non-corrosive, non-flammable, brown colored liquid made from fermentation of plants and extracts of vegetables and fruits was used with different dosages of 3 m3 per 200 ml, 2 m3 per 200 ml, and 1 m3 per 200 ml. The properties of soil were established at different ages of 0th, 7th, 14th, and 21st days. It has been observed that the addition of Terrazyme improved the shear strength and compaction characteristics and increased in the permeability of soil. The dosage of Terrazyme and the age of Terrazyme treated soil had considerable influence on properties of black cotton soil. The test results are represented in the form of tables and graphs.