Probabilistic Calculation of the Corrosion Initiation of steel reinforcement Using Reliability Methods

Reinforcement corrosion due to chloride ingress into the reinforced concrete (RC) structures adjacent to the sea and bridge in the snow-prone areas caused compromising the operation of these RC structures over time. Thereby in some of these structures, corrosion initiation is used for operational limit-state. There are so many methods for calculation of corrosion initiation time. There are many uncertainties in these models and because of that some errors made in calculated corrosion initiation time. In this paper using structural safety calculations and Monte Carlo sampling method (MC), the probability of corrosion initiation is calculated. As a new approach, corrosion initiation time is calculated based on the level of structural performances with the probability of 25,50 and 75 percent for the occurrence of corrosion initiation. Concrete quality, as well as the severity of environmental factors, were used as other basic parameters in this study. The uncertainty in the calculated time to corrosion initiation is also evaluated based on the statistical properties of the effective parameters in the model. Based on the results obtained, increasing the quality of concrete by reducing permeability has a greater effect on increasing the time for the first inspection of concrete structures.