Performance of Self-Healing Concrete in Coastal Infrastructure Applications

Abstract

Coastal infrastructure is continuously exposed to aggressive environmental conditions such as chloride ingress, tidal action, high humidity, and cyclic wet–dry loading, which accelerate deterioration of conventional concrete structures. Self-healing concrete has emerged as an innovative material solution aimed at enhancing durability and reducing long-term maintenance requirements in such environments. This study investigates the performance of self-healing concrete for coastal infrastructure applications by evaluating its mechanical strength recovery, crack closure efficiency, and resistance to chloride penetration. The methodology involves the preparation of concrete specimens incorporating self-healing agents such as microencapsulated healing agents, bacteria-based systems, or crystalline admixtures. Controlled microcracks are induced in the specimens through mechanical loading, followed by exposure to simulated coastal environmental conditions. Healing performance is assessed using ultrasonic pulse velocity, water permeability tests, scanning electron microscopy, and compressive strength recovery measurements over a defined curing period. The results indicate that self-healing concrete exhibits significant crack closure capability, with improved microstructural densification over time. A notable reduction in water absorption and chloride ion penetration is observed compared to conventional concrete, indicating enhanced durability. Strength recovery of damaged specimens demonstrates the effectiveness of healing mechanisms, particularly under prolonged exposure to moisture-rich conditions typical of coastal zones. The study also highlights that bacterial-based self-healing systems provide superior long-term performance due to continuous precipitation of calcium carbonate within cracks. It is concluded that self-healing concrete significantly improves service life, reduces maintenance frequency, and enhances structural resilience in coastal infrastructure.