Study on effect of Microbial Induced Calcite Precipitates on strength of fine grained soils

This study intents to experimentally analyse the effectiveness of use of an unorthodox liquid soil stabilizer, Microbial Induced Calcite Precipitates (MICP) for improving the shear strength parameters of two different types of fine grained soils. For this process, a species of Bacillus group, B. pastuerii was used to activate and catalyse the calcite precipitation caused by reaction between urea and calcium chloride. Two types of soils, i.e. intermediate compressible clay and highly compressible clay were used for the study. Parameters included concentration of B. pasteurii, concentration of the cementation reagent and duration of treatment. These parameters were applied on both the soils in a specified range in order to optimise their usage. The results proved that with the use of MICP, there was an noticeable improvement (1.5-2.9 times) in the unconfined compressive strength of both type of soils. It was also found that the strength increased with an increase in duration of treatment. Based on this study, optimum quantity and concentration of liquid additive to be added for different soil types for better strength increments were established.

Source: Perspectives in Science - April 23, 2016 Category: Science Source Type: research