Integrating sustained service loads into service-life prediction of corrosion-exposed reinforced concrete structures: Current status, challenges, and future perspectives

Corrosion of reinforcing steel is a key mechanism governing the long-term degradation of reinforced concrete (RC) structures, making reliable service life prediction essential for durability-based design. Existing codes and standards provide comprehensive guidelines based primarily on environmental exposure and material properties. However, the frequent occurrence of premature deterioration, often before the intended design life, raises concerns regarding the reliability and broader applicability of these approaches. A systematic evaluation of existing durability models reveals significant limitations arising from the simplified treatment or complete neglect of load-induced effects, leading to potential inaccuracies in service life prediction. Traditionally, structural design and durability assessment have been treated as independent domains, focusing separately on mechanical response and environmental degradation. This separation restricts the ability to capture the coupled mechanisms governing deterioration under realistic service conditions. To address this critical issue, This study presents a comprehensive review of methodologies used for service life assessment of RC structures in corrosive environments, with particular emphasis on the role of sustained service loads. The influence of loading on chloride transport, corrosion resistance of reinforcing steel, and cracking resistance of concrete cover is critically examined. The limitations of current models in accounting for these interactions are systematically analyzed. Based on these insights, a revised durability design perspective is proposed, wherein load- and stress-related effects are treated as integral components of prediction models. Incorporating service load effects within a performance-based framework can improve prediction accuracy and support the development of more durable and resilient infrastructure.