Advances in Self-Healing Concrete: Flexural Strength Recovery in Bridge Applications

Bridges are a critical component of modern infrastructure, yet conventional concrete is highly susceptible to cracking, alkali–aggregate reactions, and environmental stressors that accelerate deterioration, reduce flexural strength, and increase maintenance demands. This paper reviews recent advances in self-healing concrete (SHC) technologies and synthesizes reported findings on their potential to enhance bridge durability and sustainability. Particular attention is given to microbial calcium carbonate precipitation, encapsulated polymer systems, and mineral admixtures as autonomous crack-healing mechanisms. In microbial-based systems, dormant bacterial spores embedded within the concrete matrix are activated by moisture ingress, leading to calcium carbonate precipitation that seals microcracks and contributes to strength recovery. Reported outcomes indicate partial to substantial recovery of flexural strength, with performance influenced by crack width, healing duration, and material composition. Additional approaches, such as bacterial immobilization within recycled aggregates, show promise for improving healing efficiency while supporting environmental sustainability. Although challenges remain regarding large-scale implementation and long-term field performance, current research suggests that self-healing concrete represents a promising strategy for extending bridge service life and reducing lifecycle maintenance costs.