Micro-induced Calcite Precipitation: Crack Sealing Application

This paper investigates the sealing and healing properties of micro-induced calcite precipitation with regard to surface finish and sealing cracks in cementitious materials. Sporosarcina pasteurii has been used to effectively precipitate calcium carbonate in order to seal porous media. The bacteria are fed a nutrient broth mix to create conditions where microbiologically induced calcite precipitation (MICP) can be effectively used. The tests carried out, assessed the effect of MICP on a sample of twenty-four concrete cubes and to what extent the surface has been consolidated. Weight gain was measured and a Mohs hardness test was used to evaluate the surface condition of the treated surface. In addition, three fibre reinforced concrete beams were micro-cracked to evaluate Sporosarcina pasteurii’s ability to seal cracks that are common in concrete structures globally. Calcite deposits were observed to be effective at sealing cracks and consolidating the surface finish of the concrete. The treatment is an organic remedial method that has industrial applications.