EXPERIMENTAL STUDY ON BACTERIAL CONCRETE WITH PARTIAL REPLACEMENT OF CEMENT BY FLY ASH

One of the most common problems developed in concrete is about cracks. Cracks are unavoidable in concrete and make the concrete elements weak. Cracks allow water and other salts to seep through them and make the concrete weak and reduce the life of concrete. Corrosion of steel due to salts weakens the reinforced concrete in tension as well. So there is need to develop the methods for curing the cracks and regaining the strength of concrete structures. Currently synthetic polymers can be used to repair the cracks which are harmful to environment which lead to develop biological treatment techniques. In this study, a biological repair technique was used in which bacteria of 105 cells/ml were mixed with concrete to heal the cracks. The experiments were carried out to evaluate the effect of Bacillus subtilis on the compressive strength, Tensile strength and Flexural test for 3, 7 and28 days. In addition to above technique fly ash was partially added in the place of cement. The fly ash (0, 10 and 30 %) was added by weight of cement in concrete mix and experiments were carried out. The experimental results show that 10 % fly ash replaced concrete with and without bacteria has more strength when compared to the conventional concrete