Published Paper Details:

Concrete has a large load bearing capacity for compression load, but the material is weak in tension. That is why steel reinforcement bars are embedded in the material to be able to build structures. The steel bars take over the load when the concrete cracks in tension. That Cracks in concrete leads to the seepage of salts and water causing damage to the structure. So there is a need to use microbial material which self heals the cracks present in the concrete. In the present study, hay bacillus was used as a microbial material for the preparation of bacterial concrete. Normal concrete was prepared for comparison with bacterial concrete. Rice husk ash (RHA) and Quarry dust (QD) are used as a partial replacement of cement and fine aggregate in both normal concrete and bacterial concrete. Cement was partially replaced with 5%, 10%, 15% RHA and fine aggregate was replaced with 45% QD. Hay bacillus was added in the amount of 105cells/ml during the mixing of bacterial concrete. Hay bacillus releases calcium precipitate which combines with carbonates present in the concrete and forms calcium carbonate which fills up the internal voids present in the concrete. Tests were performed to determine the compressive strength, split tensile strength and flexural strength for 3, 7 and 28 days. It is observed that bacterial concrete shows higher strength compared to normal concrete due to internal filling of voids by calcium carbonate. Concrete with RHA and QD shows little less strength than the normal concrete due to its less workability.