ASSESSMENT OF STEEL REINFORCEMENT CORROSION DURABILITY OF REINFORCED CONCRETE BRIDGE STRUCTURES IN MARINE ENVIRONMENTS USING THE FICK CHLORIDE DIFFUSION MODEL

Abstract

Corrosion of reinforcing steel caused by chloride ingress is one of the main factors reducing the durability and service life of reinforced concrete bridges operating in marine environments. Among the governing parameters, the thickness of the concrete cover and the chloride diffusion properties of concrete play a decisive role in determining the time to corrosion initiation.
This paper presents an assessment of the corrosion initiation time of reinforcing steel in typical structural members of Van Thanh Bridge (Lam Dong Province) under coastal environmental conditions, based on the chloride diffusion model according to Fick’s law. Calculations were carried out for four different structural components with varying concrete cover thicknesses and concrete strength levels, using input parameters representative of the local marine environment. The results indicate that the time to corrosion initiation increases significantly with increasing concrete cover thickness, whereas the use of higher-strength concrete provides limited improvement when the cover thickness is small. The findings highlight the importance of appropriate design parameters in enhancing corrosion resistance and extending the service life of reinforced concrete bridges in aggressive environments.