Self-Healing Concrete: Mechanisms, Microbial Approaches, and Applications for Sustainable Infrastructure

Abstract: Self-healing concrete (SHC) has emerged as a sustainable and innovative material. It aims to improve the durability and lifespan of reinforced concrete structures. Conventional concrete can develop microcracks, which allow harmful agents like chlorides, sulfates, and carbon dioxide to enter. This results in reinforcement corrosion and structural decay. These problems increase maintenance costs and shorten the life of concrete structures. Therefore, creating materials that can heal themselves is essential for sustainable infrastructure. Recent developments in SHC focus on adding self-repair mechanisms within the cement matrix. Bacteria-based methods use microbial activity to produce calcium carbonate. This effectively seals cracks and restores structural strength. Encapsulated chemical agents, which are found in microcapsules or networks, activate when cracks occur. These agents fill voids and restore mechanical continuity. Fiber reinforcement strategies help control crack growth and improve healing efficiency. Combining these methods helps SHC maintain its durability and mechanical performance while reducing maintenance needs. Experimental studies and field tests have shown SHC's effectiveness in various environments, including transportation infrastructure, marine structures, and high-performance buildings. Both lab tests and real-world applications indicate that SHC can significantly repair cracks under different conditions. This offers better structural resilience and extends service life. These studies also show that SHC can lower lifecycle costs, material use, and environmental impact.