An Experimental study on Performance of Bacterial Concrete

Abstract

Concrete is a major aspect on which strength, durability of structure and economy depends. Development of cracks is common and frequent phenomon because of freeze-thaw reaction, shrinkage,

 mechanical compression and tensile force. For sustainable concrete it is necessary to increase strength and durability of concrete. Maintenance and repairing of cracks tends to have deliberate working process, uneconomical and critical solutions. Cracking of the concrete surface may enhance the deterioration of embedded steel bars as ingression rate of corrosive chemicals such as water and chloride ions into the concrete structure increased due to exposure. 

This paper presents the experimental investigation for bacterial concrete using Bacillus Subtilis. Bacterial concrete is a concept in which bacteria is induced in concrete or mortar while mixing and these bacteria assist concrete to heal cracks by segregating lime. The experiments were carried out on M25 grade of concrete to evaluate the effect of Bacillus Subtilis on the compressive strength, Flexural strength test 7, 28 and 84 days. The Plate count test was conducted to determine the presence of viable cells in a bacterial culture by plate count method. The analysis shows that there is presence of self healing compound in cracked concrete. The comparative study of normal concrete, concrete with direct insertion of bacteria and indirect insertion of bacteria has been done. The experimental results show that by insertion of bacteria it not only heals cracks but also increases compressive strength of concrete. Bacterial concrete is more preferable for underwater construction activities, as it heals the cracks by microbial activity.