Studies on the Development of Eco-Friendly Self-Healing Concrete - a Green Building Concept

Cracks are the main cause for structural failure. One way to circumvent costly manual maintenance and repair is to incorporate an autonomous self-healing mechanism in concrete. This study exploited the potential to apply calcite-precipitating bacteria as a crack-healing agent in concrete. These bacteria were prepared in different cell concentrations and incorporated in the concrete mix. Compressive strength tests were performed at the stage of 28^th day of curing. The effects of different cell concentrations of Bacillus sphaericus on concrete, reducing the crack, were studied. We used mortar cubes with 30mL of bacteria/mortar cube and sequentially increased up to 50mL (10, 20, 30, 40 and 50mL) in the ratio of mortar cubes in 1:6. The concrete grade used for the study was M25. At last, we had made concrete blocks of size 150×150×150 mm with concrete of grade M25. For those blocks, the compressive strength and non-destructive tests such as, rebound hammer and ultrasonic pulse velocity tests were performed. The results obtained in the work are that the compressive strength of blocks of size 150×150×150 mm is good when compared to control concrete. When load is applied to control concrete, the crack gets developed earlier and when bacterial concrete is used, the crack does not develop at an early stage.