Study on the prompting effect of basalt fibers on the change from two-dimensional to three-dimensional deposition of CaCO3 to improve the healing properties of microbial mortars

Microbial-induced calcium carbonate precipitation (MICP) is utilized to effectively seal microcracks in concrete. In this study, coconut shell charcoal was used as a carrier for adsorbed bacteria to act as a biomass self-healing agent, and the healing effect of microbial mortar was enhanced by the addition of basalt fibers. The effect of the combined action of biomass self-healing agents and fibers on the mechanical properties and healing ability of mortars has been investigated. The complete process of microbial metabolism in the cement matrix was firstly revealed by microscopic experiments. Optical microscopy was used observed the deposition paths of the fillers under multifiber conditions at different depths. The results showed that a large number of fibers changed the healing products that transformed from two-dimensional to three-dimensional due to the bridging effect between the calcium carbonate grown on the neighboring fibers, which enhanced the healing ability of the cracks.