Application of carbonate-mineralization bacterium in surface protection of cement based materials

Bacterially induced calcium carbonate precipitation was used as a novel and environmentally friendly approach to produce a protective layer on the surface of cement-based materials in the study. The physical and chemical properties of the obtained layers were examined. The composition of the deposited layers was characterized by X-ray diffraction analysis and the morphology of the particles was displayed by scanning electron microscopy. The results show that bacterial activity has a profound effect on the properties of the calcium carbonate layers. A capillary water absorption test was carried out to evaluate the ability of the protective layers. Experimental results indicate that the calcium carbonate layer, obtained under the conditions of a high bacterial activity and an appropriate concentration of Ca²⁺ can greatly improve the water penetration resistance of the specimen surfaces. This type of treatment has the potential to conserve and consolidate cement-based materials.