Experimental Study on Flexural Behaviour of Self Healing Concrete using Bacillus Substilis Bacteria

Abstract

This investigation experimentally deals with the crack healing ability of bacteria, like a small cut in our body can be healed by a simple treatment. The cracks in the concrete is the major problem in construction industry. The repair of cracks is usually carried out by means of some kind of human intervention. As regular and manual maintenance of cracks repair in construction industry is costly and in some cases not at all possible. To solve this problem, insertion of bacteria can be highly favorable as it could both reduce maintenance and increase the durability of concrete. In this study a specific group of alkali resistant spore farming bacteria Bacillus Substilis were selected and added in different proportions with silica gel and calcium carbonate in a glass tube and is kept in the concrete during casting. The M20 grade concrete was used. The cube and cylinder specimens were tested for compressive and split tensile strength test up to the initial cracks at the age of 7, 14 and 28 days. The optimum quantity of bacteria was found from the test results. Beam specimens were casted for the optimum mix and tested for flexural behavior. The Load carrying capacity, Energy absorption capacity, Stiffness and Ductility characteristics of Self-Healing Concrete beam were found and compared with the conventional concrete beam. The test results shows Self-Healing Concrete beam attained higher load carrying capacity, energy absorption capacity and deflection and lesser stiffness and ductility when compared to the conventional concrete beam.