Influence of Bacteria on Durability of Concrete by Bacterial Mineral Precipitation

Most of the world population is getting urban centric and as a result the use of concrete is swiftly increasing worldwide, however is that its immense production exerts adverse impact on the environment. An innovative approach to reinstate or remediate such structures is bio mineralization of calcium lactate to calcium carbonate using microbes, such as Bacillus species (viable but dormant bacteria). The present study investigated the effects of Bacillus pasteurii on compressive strength, flexural strength, water permeability and rapid chloride penetration test on three samples having different proportions. The results indicated a maximum of 12.67% increase in initial compressive strength, 10.54% in final compressive strength and 18.67% increase in flexural strength of cement mortar cubes. Minimum depth of water penetration was found to be 20.43mm while the chloride penetration of concrete changed from “moderate� to “low� when compared with controlled cubes for M40 grade of concrete. The results clearly showed microbially induced calcium carbonate precipitation can be applied for several building materials for enrichment of durability.