Crack-healing ability of concrete enhanced by aerobic-anaerobic bacteria and fibers

In this study, the self-healing of cracks in four repair systems mixed by aerobic-anaerobic bacteria and fiber is studied. The results showed that specimens S-1, S-3, and S-4 demonstrate remarkable efficacy in achieving complete repair for the majority of cracks with widths of 0.6 mm or less within a healing period of 28 d. Conversely, cracks exceeding 0.45 mm in width in specimen S-2 present challenges in achieving complete restoration. The Water permeability experiments showed that the crack repair effect of the four groups of specimens was in the following order: S-4 > S-3 > S-1 > S-2. Notably, cracks with initial widths <0.4 mm exhibit a commendable secondary repair rate of approximately 90 %. Further analysis underscores the fiber-reinforced binary microbial mineralization repair system (S-4) as yielding optimal repair outcomes, significantly enhancing water seepage resistance post-repair. This comprehensive investigation underscores the potential of our proposed repair systems to effectively crack-healing.