Repair of concrete existing micro-cracks by use of microbially induced carbonate precipitation

Micro-crack is the start of concrete deterioration and failure, though it does not decrease bearing capacity in beginning. In order to prolong service life existing structures, important repair micro-cracks before they develop into large cracks, which are much more harmful. Bio-genic CaCO 3 from microbially induced carbonate precipitation (MICP) process proved be a promising crack material due its environmental friendliness super compatibility with cementitious matrix. this study, MICP based technology was applied micro-cracks. The influence environment technique on bio-CaCO investigated. Results shown that moderate alkali pH had limited effect properties . Bacteria could still induce if saturated Ca 2+ containing deposition medium. Crack width 0.5mm can fully sealed within days by use controlled injection technique.