A Study On Strength Characters of Bacterial Concrete

Concrete is unique in all construction material because it is specificallydesigned for civil engineering purpose. It plays a critical role in the construction of the nation's infrastructure. The cracks in concrete whether major or minor are one of the weakness of concrete. These cracks will be developed over a period of time which adversely affect its strength and durability. Hence an attempt is made here using bacteria belongs to bacillus family used to heal minor cracks in concrete. These types of bacteria were introduced externallyto improve the process of Microbiologically Induced Calcite Precipitation (MICP) in concrete. It (MICP) is a technique that comes under thestudy of science called bio mineralization. Bacillus subtilis, one of the soil bacterium can induce the Precipitation of calcite. The present work is to study the potential application of bacterial species bacillus subtilis in healing the minor cracks there by improving the strength of cement concrete. Here M20 grade of concrete was used for the study. The concrete mix was prepared as per IS specifications. Testing on specimens for compression was carried out after 28 days of curing using both CTM and NDT equipment's and results are tabulated. Minor cracks less than one millimeter are induced artificially in concrete and the broth solution having bacterial culture in it are injected along the crack pattern. After healing, compressive strength was tested using NDT equipment and was found a marginal improvement in the strength criteria.