The project aims at attaining high durability of concrete and gaining high strength of cement. We plan to make use of bacterial species which can hydrolyze the enzyme Urease efficiently to produce microbial concrete. Such bacterial are known to produce calcium which is useful in giving strength to cement.
We are working in 2 stages.
Stage 1: Here we check the effect of bacterial solution on cement mortar and along with that we check the effectiveness of the bacterial solution to fill the cracks in concrete by precipitation of calcium in the cracks. Stage 2: To prepare concrete using the cement and solution (bacterial) in optimum ratio and checking its effectiveness from strength and durability perspective.
Till now Stage 1 is partially over: We have made use of this bacterial solution(Emulsion: Bacillus culture+ nutrient broth+ sucrose+ urea+ calcium chloride+ antifungal agent(griseofulvin)to heal the existing cracks in the concrete walls. For achieving high 7 days we have made use of bacterial solution in some fixed proportion with water. The 7 days test was performed on 7/12/11 with 5%, 10%, and 15% of the bacterial solution with respective percentage of water. We have gained a significant percentage increase in the strength of the cubes made with bacterial solution with water versus those made with only water
Bacteria at work
Microbially induced calcite precipitation (MICP)
Microbially induced calcite precipitation (MICP) is known to be a natural phenomenon associated with a wide range of bacterial species such as Bacillus spp. provided the right conditions, namely, an alkaline environment rich in Ca2+ ions. Bacterially induced mineralization has recently emerged as a method for protecting and consolidating decayed construct materials. Calcite (CaCO3) is one of the most common and widespread minerals on the earth, constituting 4% by weight of the earth’s crust. Calcite precipitation is a common phenomenon which forms natural...
References: * Microbial activity on the microstructure of bacteria modified mortar by S.Ghosh, M.Biswas, B.D. Chattopadhyay, S.Mandal.
* Effect of calcifying bacteria on permeation properties of concrete structures by Dr. Varenyam Achal.
* Work on BacillaFilla by New Castle University.
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