Experimental Analysis of Bacterial Concrete

Concrete is the predominate material used in the structural engineering stream. Concrete is widely adopted in huge structures (commonly used in buildings).It is known for its durability, ductility and resistance towards the external loads. If water droplets enter into the concrete structure due to lack of permeability then it can damage the steel reinforcement present in the concrete member .when this phenomenon occurs, the strength of the concrete decreases and which results in the decay of structure. To prevent these phenomenon bacteria was introduce in concrete. Now a day’s calcium lactate powder has been used along with bacteria in concrete which results in the formations of calcium carbonate crystals. These crystals look like precipitate chain which locks the minute cracks and also the pores in the concrete. Cracks are the major reason for the reduction of strength and permeability in the concrete. Therefore a novel technique has been developed by using a selective microbial plugging process, in which microbial metabolic activities promote calcium carbonate (cacite) precipitation, this technique is referred as microbiologically enhanced crack remediation . In this technique bacillus subtil us bacteria are used hence the concrete is called bacterial concrete. The percentages of bacteria selected for the study are 3.5% and 5% by weight of cement in addition , calcium lactate was used at 5% and 10% replacement of cement by weigh .test conducted as compresive strength. The following conclusions are reported from the experimental work carried out and from the results obtained from compressive strength and self healing capacities of casted specimens. The optimum compressive strength of bacterial concrete is obtained at 15gm of bacteria and 5% of calcium lactate. It is observed that the compressive strength of bacterial concrete is more than that of the conventional concrete. By using the bacteria we can decreases the maintenance cost of construction and helps in self healing. The total cost of the project is increased at the stage of construction and after that there is a decrease in the maintenance cost.