Enrichment of compressive strength in microbial cement mortar

Abstract

The method of microbial mineral plugging in porous media is common in nature. Physical and biochemical properties of calcium carbonate (CaCO3) precipitation induced by Enterobacter and Serratia microorganisms into cement mortar specimens are studied and analysed. X-ray diffraction is used to identify the calcium carbonate crystal as calcite, vaterite, aragonite. Scanning electron microscopy (SEM) is used to verify the formations of white precipitation (calcium carbonate) in the microbial cement mortars. The improvement of strength in the concrete/cement mortar base is attributable to the formation of calcium carbonate, which fills the pores between the cement sand matrices. In the present study a noteworthy enhancement of compressive strength of 44% is observed in the biocuring Enterobacter-treated specimen relative to control. This method of implanting semi-solid mixtures onto the surface of the cement paste specimens shows significant effects such as decrease of permeability and capillary water penetration.