Abstract
Bacillus flexus MK-FYT-3 and Bacillus haynesii MK-NW-9 were isolated, identified and used to construct a bacterial consortium that was able to heal small cracks of concrete and improve its properties. The results showed that the compressive and tensile strengths of bio-concrete significantly increased by (31.29, 36.3) (29, 39) % and less permeability with 21.1%, 23.1% after 7, 28 days respectively. Ultrasonic pulse velocity test was performed, and the bio-concrete gave higher values than control by 26% and 20% after 7, 28 days. In addition, surface healing of bio-concrete showed white precipitates around and inside the cracks after 7 days, which led to almost complete sealing of concrete after 28 days. The micro-analysis of bio-concrete using SEM and XRD showed crystalline precipitate with different shapes under SEM. We concluded that a bacterial consortium was able to repair and prevent the concrete cracks from spreading in addition to improving properties of concrete and that lead to increasing its life and sustainability.
Disclosure statement
No potential conflict of interest was reported by the authors.