摘要：Cracks are the main cause for structural failure. One way to circumvent costly manual maintenanceand repair is to incorporate an autonomous self-healing mechanism in concrete. This study exploitedthe potential to apply calcite-precipitating bacteria as a crack-healing agent in concrete. These bacteriawere prepared in different cell concentrations and incorporated in the concrete mix. Compressivestrength tests were performed at the stage of 28th day of curing. The effects of different cellconcentrations of Bacillus sphaericus on concrete, reducing the crack, were studied. We usedmortar cubes with 30mL of bacteria/mortar cube and sequentially increased up to 50mL (10, 20, 30, 40and 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 pulsevelocity tests were performed. The results obtained in the work are that the compressive strength ofblocks of size 150×150×150 mm is good when compared to control concrete. When load is applied tocontrol concrete, the crack gets developed earlier and when bacterial concrete is used, the crackdoes not develop at an early stage.
