Chloride Transport Modeling in Concrete Subjected to Tidal Condition: Effect of Water to Cement Ratio on Maximum Chloride Concentration

Chloride penetration into concrete and consequently corrosion of reinforcing steel is one of the main causes of concrete deterioration in Persian Gulf and Sea of Oman. Concrete deterioration exposed to tidal condition is very severe when compared to the atmospheric exposure condition. Therefore, it is necessary to accurately model the simultaneous moisture and chloride ingress into concrete for durability-based design of reinforced concrete structures. In this study, a finite element model was developed to numerically solve the governing differential equations of moisture and chloride transfer. Comparison of the model output with the ones obtained from experimental works in Bandar Abbas and Qeshm research sites showed that the proposed model can predict the chloride profile with good accuracy. By using the test results, the model output showed that the maximum chloride concentration decreased with increasing in water to cement ratio (w/c) from 0.40 to 0.45 and then slowly increased with increasing in w/c up to 0.55. Although, the total chloride concentration, which ingress into concrete, increased up to 50 %.