Estimation of Corrosion Initiation Time in Reinforced Concrete Bridge Columns: How to Incorporate Spatial and Temporal Uncertainties

Deterioration of reinforced concrete structures has been a subject of interest for the researchers, practicing engineers, and decision makers who work on the reliability assessment and safety evaluation of civil infrastructure systems. Over the last two decades, several studies have approached this subject and developed numerical and experimental methods to quantify the extent of deterioration over time. The studies completed to date, however, lack the comprehensive probabilistic approach needed to consider the uncertainties involved in the deterioration of structural components during their service life. To address this issue, the current study develops a computational framework that examines the time-dependent effects of multiple environmental stressors on the integrity of structural components. This framework takes into account the mutual interactions of all exposure factors and provides a reliable estimate of the extent of penetration of deteriorating agents into concrete. Given the capabilities of this framework, the scope of this investigation is extended to incorporate various sources of uncertainty into the predictive models. For this purpose, the most influential parameters that represent material properties, geometric characteristics, exposure conditions, and limit state criteria are considered as random variables and their corresponding probability distributions are identified. Multidimensional Gaussian and non-Gaussian stochastic fields are generated to evaluate the spatial variation of each of these parameters. The generated fields are introduced to the computational framework and the probabilistic measures of the vulnerability of structural components to the attack of deteriorating agents are presented.