Self-Healing Concrete

Crack formation is very common phenomenon in concrete structure which allows the water and different type of chemical into the concrete through the cracks and decreases their durability, strength and which also affect the reinforcement when it comes in contact with water, CO2 and other chemicals. Cracks in concrete structures can significantly decrease their lifespan by exposing reinforcement to outside environment, leading to concrete degradation. To address this issue, self-healing techniques have been developed, including Biomineralization-based-self healing, where bacteria are employed to initiate Microbially Induced Calcium Precipitate (MICP), promoting the healing of cracks. Moreover, there exists a direct correlation between bacterial cell concentration and alterations in the mechanical properties of concrete. The incorporation of bacteria in concrete leads to increment in strength properties, with strength enhancement of up to 42.8 %. The selection of the bacteria was according to their survival in the alkaline environment such as Bacillus subtilis and B. lichenformis which are mainly used for the experiments by different researchers for their study. Cement and concrete matrices reinforced with randomly oriented short fibers are finding increasing applications in both precast and in situ concrete construction. In this process, fibers are incorporated to regulate crack width, ensuring an optimal environment for bacterial activity. By limiting crack expansion, the effectiveness of bacteria in the self-healing mechanism is enhanced, leading to improved durability and performance of the material.