Chloride diffusion analysis of concrete structures considering effects of reinforcements

The reinforced concrete structures exposed to sea environments suffer from corrosion of steel bars due to chloride ingress. The chloride penetration into concrete is influenced by many parameters such as type of cement, mixture proportions, and existence of reinforcing bars. The conventional diffusion analyses have neglected the existence of steel bars in concrete. The purpose of the present study is, therefore, to study the effects of reinforcement on the chloride diffusion in concrete structures by incorporating realistic diffusion models. To this end, the nonlinear binding isotherm that includes the effects of cement types and mixture proportion has been introduced in the chloride diffusion analysis. The effects of reinforcements on the chloride penetration have been analyzed through finite element analysis. The present study indicates that the chlorides are accumulated in front of a reinforcing bar and the accumulation of chlorides is much more pronounced for the case of larger-size bars. The higher accumulation of chlorides at bar location causes faster corrosion of reinforcing bars. The corrosion initiation time reduces by about 30 to 40% when the existence of reinforcing bars is considered in the chloride diffusion analysis. Therefore, the effects of reinforcements must be properly considered in the chloride diffusion analysis to obtain more accurate and realistic estimation for the service life of concrete structures.