ISSN 2319-5347, ISI Impact Factor: 0.763

VOLUME 04 NO. 03 JULY 2015:

Title:         Effect of bacteria on strength of concrete
Authors: Ravindranatha, Likhit M. L., Udayashankar H. N., Suhas S. Vokunnaya
Abstract:  The infrastructure is a very basic need of any industry. The necessity for such infrastructure is high level of service and performance, high durability and minimum negative ecological impact. In all concrete structures, crack is one of the main concern .Cracks form an open pathway to the reinforcement and can lead to durability problems like corrosion of the steel bars. These cracks should be repaired because they can reduce the service life of the structure. Here an Overview is given of new developments obtained in research on self healing of cracks in cement based materials .Bacterial concrete, as the name indicates is an improvisation provided to cement using living microbes which are capable of doing so. Using microbes such as Bacillus pasteurii, which has properties of bio calcification, can secrete calcium carbonate as an extra cellular product thus filling the pores and the cracks internally making the structure more compact and resistance to seepages. As the texture becomes more compact the compressive strength, flexural strength &split tensile strength is considerably increased. The process can reduce the seepage.The laboratory tests are conducted on 43 grade ordinary Portland cement (OPC).the physical tests of ingredient materials are conducted according to IS specifications .For laboratory tests M25 concrete is adopted. On hardened concrete the strength related test such as Compression, Split tensile and flexural tests on cubes,cylinder and beams are conducted as per IS specifications. It is found out that increase in compressive strength is as much as 30% for all cubes after 3, 7, 14, 28 days of curing .The increase in split tensile is found out to be more than 35%.The increase in flexural strength is found out to be more than 11%.
Keywords: Bacillus pasteurii, compressive strength, flexural strength, and Bio-calcification

pages                177-180

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