Mortar Crack Repair Based on Staphylococcus epidermidis –Induced Carbonate Precipitation

As an emerging concrete durability enhancement technology, microbial-induced carbonate precipitation has been of great significance for low-carbon development. In this investigation, Staphylococcus epidermidis (S. epidermidis) was selected as a microbial remediation agent. The medium was improved by using metal-cation doping to reveal the effects of ion type and concentration on the growth activity of S. epidermidis. The repair effect of S. epidermidis on mortar with different crack widths was verified through macroscopic and microscopic experiments, and the biotechnology potential of S. epidermidis in mortar crack repair was expounded. The results demonstrated that nickel ions could enhance the growth of S. epidermidis, with 10 μmol/L nickel ions having the most pronounced effect. Cracks in the range of 0.2–0.6 mm could achieve a repair rate exceeding 89% after repair, and the impermeability and compressive strength of specimens were enhanced. The repair products consisted primarily of spherical calcite calcium carbonate particles. This investigation provides a practical basis for the application of S. epidermidis in mortar crack repair, which is expected to contribute to the extension of the service life of concrete structures and promote the sustainable development of the construction industry in an environmentally friendly and low-carbon way.