Concrete is the most commonly used building material, the cracks in concrete create problem. Cracks in concrete occur due to various mechanisms such as - shrinkage, freeze-thaw reactions and mechanical compressive and tensile forces. Cracking of the concrete surface may enhance the deterioration of embedded steel bars as ingression rate of corrosive chemicals such as water and chloride ions in to the concrete structure increased. Therefore a novel technique has been developed by using a selective microbial plugging process. One such thought has lead to the development of a very special concrete known as Bacterial Concrete where bacteria is induced in the mortars and concrete to heal up the faults. In this study, Bacillus Sphaericus bacteria of concentration 1x106 cells/ml are used. The properties of control concrete and bacterial concrete are studied by conducting various tests such as compressive strength, split tensile strength, flexural test with varying grades of concrete M20, M25, M30. This study showed a significant increase in the strength was observed due to the addition of bacteria for a cell concentration of 106 cells per ml of mixing water and therefore calcium carbonate precipitation deposited in micro cracks.
