Experimental investigation on stabilization of subgrade soil using bio-enzymatic additive for pavement construction

Regions with soil having poor bearing capacity suffer from increased construction cost and waste generation due to the replacement of soil. Bio-enzymes help stabilizes the soil by acting as a catalyst in strengthening such soils. Effects of these enzymes vary based on soil properties and application rates. Thus application rates need to be determined for a soil type exclusively. In this study, clayey soil with intermediate plasticity was treated with different dosages of Terrazyme in order to determine the optimum dosage of the enzyme. Results show that the strength gain is a function of curing time. Unconfined compressive strength (UCS) and California bearing ratio (CBR) values of treated soil increased with an increase in the curing period. Permeability test of Terrazyme treated surface confirmed that it also acts as a waterproofing agent and can be used for dust control on unpaved surfaces with low traffic. The findings substantiate the suitability of bio-enzymatic additives for stabilization of subgrade soil making them apt for use in pavement construction.