Strategy for enhancing the durability of marine concrete structures in northeast China

This study investigates the durability and service life of marine concrete structures in Northeast China’s aggressive coastal environments by integrating reliability theory with a modified chloride diffusion model. A synergistic durability enhancement strategy is proposed, combining surface protection, critical chloride concentration optimization, and corrosion-resistant reinforcement. Key findings reveal significant variations in corrosion initiation times across exposure zones: under 5 % and 10 % corrosion probabilities, steel reinforcements in atmospheric, splash, tidal, and submerged zones exhibit service lives of 19.6–22.0, 11.9–13.4, 10.7–12.0, and 26.2–29.3 years, respectively, with submerged zones demonstrating the highest safety and tidal zones the greatest vulnerability. While single protective measures (e.g., silane coatings or corrosion inhibitors) extend corrosion initiation times, they fail to achieve a 100-year service life in marine environments. Corrosion-resistant steel alone achieves > 120 years in submerged zones but remains insufficient elsewhere. Composite strategies prove critical: silane-inhibitor combinations extend submerged zone service life beyond 120 years but still fall short in splash/tidal zones. In contrast, the integration of silane coatings and corrosion-resistant steel ensures corrosion initiation times exceed 120 years across all zones under 5 % and 10 % failure probabilities. This work demonstrates that a hybrid approach addressing both surface and material durability is essential to meet the 100-year design life requirement for marine structures in highly corrosive environments, offering practical insights for engineering applications in similar climatic regions.