Self-Healing Concrete: Autonomous Crack Repair
Extending service life of structures
Concrete cracking is inevitable due to stress, temperature changes, and shrinkage, compromising durability and accelerating corrosion. Self-healing concrete offers an autonomous solution to seal cracks without external intervention, reducing maintenance costs and improving sustainability. This study explores four major strategies—crystalline admixtures, microbiological additives, microencapsulation, and natural materials—each with distinct mechanisms and benefits.
Mechanisms and material innovations
Crystalline admixtures react with free calcium ions to form pore-blocking crystals, while bacteria like Bacillus subtilis precipitate CaCO₃ through bio-mineralization. Microcapsules release sodium silicate under stress, forming C-S-H gel for crack sealing. Natural agents such as sodium alginate and eggshell powder provide eco-friendly healing, enhancing hydration and reducing permeability.
Toward resilient infrastructure
Self-healing concrete technologies promise longer service life, reduced repair costs, and improved sustainability. While no single method meets all requirements, combining crystalline, biological, and encapsulation techniques can create robust, low-maintenance structures. These advancements mark a shift toward smart materials that prevent large-scale failures and support sustainable engineering practices.