Stabilization of Black Cotton Soil Using Red Mud, Phosphogypsum and Lime

Nowadays, the availability of good land for construction has been reduced drastically due to increase in population. Previous soil scientists took extensive efforts to find out appropriate waste material which might be utilized for stabilizing the problematic soil like expansive black cotton soil (BCS) to make it suitable for construction. Expansive soil shows unusual volume change and undesirable engineering behavior when it comes in contact with water. Hence, constructing a pavement over such soil is very vulnerable to damage, requiring high maintenance cost for its repair. In this present study, an attempt has been taken for utilizing the various combinations of phosphogypsum (PG), red mud and lime with black cotton soil to access and improve their geotechnical behavior. The effects of phosphogypsum (PG), lime and red mud treatment on BCS have been investigated in the laboratory by conducting various tests such as California bearing ratio (CBR) test, standard proctor test (SPT) and unconfined compression stress (UCS) test. Considerable improvement has been noticed in the value of UCS and maximum dry density (MDD) when 2% of PG was added to mix of BCS and red mud in the ration of 3:2, whereas the CBR value was found to be maximum when 5% of lime was added to the mix.