Durability assessment of a tunnel structure with two‐sided chloride ingress—A case study located in a tropical environment

Reinforced concrete structures are the backbone of the transportation infrastructure. Their structural safety and functional performance are critical to sustaining a globalized economy. Corrosion of steel reinforcement is typically triggered by chloride contamination and carbonation, becoming a primary factor in reinforced concrete deterioration. This paper presents a durability assessment of a tunnel structure located in a tropical marine environment. The condition assessment included visual examination, crack survey, cover depth measurements, half‐cell potential mapping, and concrete coring. The chloride profiles showed that the tunnel walls are subjected to chloride attack from both surfaces, an unusual finding in the literature. A stochastic approach is implemented to estimate the probability of corrosion initiation for chlorides and carbonation, including an innovative model for two‐sided chloride diffusion. The results indicate that two‐sided chloride exposure significantly reduces the corrosion initiation time.