ENHANCEMENT OF DURABILITY PROPERTIES OF BIOCONCRETE INCORPORATED WITH NANO SILICA

Bacterial concrete, the so called Smart bio material is an eco-friendly concrete in which selective cementation takes place by microbiologically induced CaCO3 .This method is introduced to remediate even micro cracks, voids and pores. Based on experimental investigation carried out the paper presents the results to enhance the mechanical and durability properties by means of introducing Enterobacter sp. in the concrete. The bacterium used in this study has the ability to precipitate calcite is the calcite precipitating bacteria which is readily mixed in the concrete. The precipitated calcite contains crystalline structure that has the ability to readily adhere to the concrete and completely arrests the rise of micro cracks and pores. In addition it has the ability to continuously grow upon itself when it comes in contact with any medium which is highly insoluble in water. The presence of nano-silica in the concrete enhances the C-S-H formation. The strength contribution in the specimen is due to the presence of organic substances. It is available as microbial biomass that is required for the biomineral precipitation. The Organic source adopted here is the yeast extract. A successful attempt has been made on the biomineralization process to enhance the compressive strength, split tensile strength and durability properties of concrete by using the Enterobacter sp. This biological treatment shows promising prospect in increasing strength aspects of the concrete.