An experimental investigation on self-healing concrete using “Bacillus subtilis”

Abstract

The current study attempts to measure the performance of concrete utilizing microbiologically generated bacteria growth. This idea led to the creation of a highly unique concrete that employs bacteria to mend defects in concrete. When cracks develop in concrete, they allow the ingress of water and various chemicals, thereby reducing its strength and durability and causing corrosion of the reinforcement. To solve this issue, bacterial concrete is developed which has an independent self-healing mechanism that assists in fracture repair by producing calcium carbonate crystals that fill micro-fissures and pores. In the present investigation, the bacterium “Bacillus subtilis” was employed based on the literature study. This bacterium was cultured and utilized as it can withstand harsh environmental conditions. The Bacterium “Bacillus subtilis” was added in volume of 10 ml, 20 ml, 30 ml, 40 ml and 50 ml in M25 concrete. The compressive strength of concrete was monitored at 7 days, 14 days and 28 days. It was observed that 30 cc of “Bacillus Subtilis” when cultures and added to the concrete gives optimum compressive strength for a M25 grade concrete. Also, the inclusion of microorganisms improved compressive strength of concrete significantly. This bacterium introduced to the concrete has successfully self-healed the cracks thereby improving its durability.