Effect of bacteria on strength and porosity of M-sand based pumpable concrete
P. Murthi, K. Poongodi, I. Rajasri Reddy
Abstract
Abstract This paper presents the results of experimental investigation which was carried out to evaluate the effect of bacteria on the compressive strength, porosity of M-sand concrete. The river sand was replaced by M-sand and M20 and M30grade pumpable concreteswere designed for investigation purpose. The w/c ratio of the concrete was selected as 0.45 and 0.4 respectively. Bacillus subtilis bacteria was included at a concentration of 30x10 5 cells/mL of water. The compressive strength, water absorption and porosity of concrete were determined after the curing periodof 3, 7, 28 and 90 days. Results were indicated that the substitution of M-sand instead of river sand was reduced the compressive strength up to 20% when compared with river sand based control concrete. The porosity and water absorptionbehaviour of M-sand concrete were observed in higher order than that of control concrete. On the addition of bacteria, 37%-45% reduction in water absorption and porosity level of bacterial M-sand concrete was achieveddue to the self-healing of micro crack in the concrete.