Effect of Bacterial Calcite Precipitation on Compressive Strength of Mortar Cubes

In this paper results are presented on an experimental investigation carried out on mortar cubes which were subjected to bacterial precipitation by different bacterial strains and influence of bacterial calcite precipitation on the compressive strength of mortar cube on 7, 14 and 28 days of bacterial treatment. Three bacterial strains Bacillus Flexus, isolated from concrete environment, Bacillus pasturii and Bacillus sphaericus were used. The cubes were immersed in bacterial and culture medium for above mentioned days with control cubes immersed in water and was tested for compressive strength. The result indicates that there was improvement in the compressive strength in the early strength of cubes which were reduced with time. Among the three strains of bacteria, Cubes treated with Bacillus flexus which is not reported as bacteria for calcite precipitation has shown maximum compressive strength than the other two bacterial strains and control cubes. Bacillus flexus which is capable of surviving at high pH, precipitate high calcite, and has less generation time can be used for bacterial calcite precipitation as concrete crack remediation and improvement of compressive strength of both mortar and concrete