A STUDY ON EFFECT OF BACTERIA ON CEMENT COMPOSITES

Vijeth N Kashyap, Radhakrishna

Abstract: Crack is commonly observed failure in the case of concrete. Crack may develop due to addition of excess of water to during mixing of concrete, or may be due to shrinkage and creep. In the present study, crack healing and improvement of physical properties of cement paste, mortar and concrete are studied. It is done by the addition of bacterial strains namely Bacillus Sphaericus and Sporosarcina Pastuerii. It is found that these bacteria when added at 106 concentration of cells/ml of water to cement composites increased by about 39.8% and 33.07% in paste. There is an increment of 50% and 28.2% in mortar for two bacterial strains. The strength increment is found to be 18.3% and 12.2% for Bacillus Sphaericus and Sporosarcina Pastuerii respectively for concrete. Ultrasonic pulse velocity of the bacterial concrete was in line with conventional concrete. SEM and XRD images revealed presence of CaCO3 produced microbially. There is overall improvement in the bacterial composites compared to conventional composites

Keywords: Bacillus Sphaericus, Sporosarcina Pastuerii Bacteria, Crack, Concentration, and Calcite

DOI: https://doi.org/10.15623/ijret.2013.0213067