Surface consolidation of natural stone materials using microbial induced calcite precipitation

Natural stone tends to have high porosity and is easily eroded by environmental weathering. In recent years, industrialisation has caused an acceleration of stone decay due to the toxic by-products of industry breaking down the stones’ constituents. This paper investigates the effect of microbial induced calcite precipitation as a natural treatment for the surface preservation and restoration of historic buildings. Sporosarcina pasteurii has been proven as a bacterium that can perform microbial induced calcite precipitation (MICP) effectively in extreme conditions making it the preferred bacterium for the MICP process within this study. The surface treatment experiment was analysed by measuring the mass increase and surface changes using scanning electron microscopy. The surface treatments showed a noticeable mass increase and observable deposition when viewed using a SEM microscope. Bio cementation of loose sand particles was observed and the degree of cementation was determined using a Mohs hardness test.