Improvement of Concrete Durability by Bacterial Carbonate Precipitation

As like humans having the ability to precipitate minerals in the form of bones and teeth continuously, even some bacteria like Bacillus pasteurii and Bacillus sphaericus can continuously precipitate calcite, called as microbiological induced calcite precipitation. The present investigation discusses on the effects of B. pasteurii and B. sphaericus on durability of concrete beams. The efficacy of the bio deposition treatment on concrete beams with bacteria, alkali, sulfate and freeze-thaw environments along with water absorption was studied. The presence of a layer of calcium carbonate and microbial biomass resulted in a decrease of permeation properties of cementation materials. This technique not only improved the concrete strength but also enhanced water impermeability through calcite precipitation, quantified by X-ray diffraction analysis. Hence this biological treatment is highly desirable and eco-friendly. The present work guarantees a biological metabolic outcome with improvement in concrete and building material technology.