Bacterial concrete has recently come into use as a repair method for fractures in several types of constructions, including bridges, reinforced cement concrete buildings, reinforced cement concrete pipes, canal linings, pavement, etc. In concrete structures, crack development is a very frequent occurrence that allows water and various types of chemicals to enter the concrete through the cracks and diminishes their strength. This also has an impact on the reinforcement when it reacts with water, carbon dioxide, and other chemicals. Henk Jonkers thus developed bacterial concrete to fix the fractures that emerged in the concrete constructions in order to address this issue. Using bacillus subtilis bacteria and calcium lactate, experimental studies have been conducted in this work to stop concrete fractures. The ability of bacteria to survive in an alkaline environment influences their selection. For M20 and M40 grade concrete with river sand mixes and crushed stone sand mixes as replacements of fine aggregate, Bacillus subtilis bacteria with calcite lactate is utilized in varying percentages, such as 5%, 10%, and 15% of cement weight. The impact of bacteria on the compressive strength, split tensile strength, and flexural strength of concrete was investigated experimentally. A scanning electron microscope was used to check for calcite precipitates in the form of calcium carbonate in bacterial concrete specimens. Energy Dispersive X-ray Analysis and X-ray Diffraction were used to confirm the presence of the calcite precipitates.

Bacterial Concrete Bacillus subtilis, Calcium lactate, Crushed stone sand, Scanning Electron Microscope, Energy Dispersive X-ray Analysis, Ultrasonic pulse velocity.