The corrosion of steel reinforcement due to chloride ions is one of the main causes of deterioration in reinforced concrete structures, particularly in the marine environment. Concrete structures that are seriously damaged by steel corrosion may entail high retrofitting and maintenance costs. Port and harbor structures such as wharves and piers that are put out of service because of corrosion of reinforcement may affect the activities in the port. A method to predict long-term chloride concentration profiles in 100% ordinary portland cement paste, mortar, and concrete with water-cement ratios in the range of 0.4 to 0.6 is presented. This approach of using the semi-empirical models enables an engineer who performs core sampling to predict the future chloride concentration profile of concrete structures in the submerged zone so that the service life of the structures can be forecast and remedial measures can be taken on time. The variation in chloride binding, with respect to the amount of cement hydrates available as a function of time and with respect to the amount of free chloride ions present as a function of distance from the surface, is also incorporated in the modeling so that the mechanisms of chloride ingress are better represented. Good correlation is observed between analytical results obtained based on the proposed method and experimental data reported in the literature. This confirms the applicability and reliability of the proposed prediction method.