Probability of Failure of Corroding Reinforced Concrete Columns under Eccentric Loading

The load-carrying capacity of an eccentrically loaded reinforced concrete column affected by corrosion of reinforcement will progressively decrease with time due to the buildup of corrosion-induced damage in the form of loss of reinforcement area, cracking and spalling of concrete cover. Due to the complexity of corrosion problems, a probability-based assessment of failure, instead of a deterministic approach to ascertain safety, is prudently more appealing. An attempt has been made to propose a method for computing probability of failure of corroded eccentrically loaded columns using Monte Carlo simulation (MCS) of a proposed limit state safety function based on a time-dependent strength prediction model for the residual strength. The MCS covers a large number of possible combinations of all governing parameters related to strength within their prescribed distributional characteristics. The results show that MCS can be used to estimate probabilities of failure, and that the corrosion current density and the ratio of eccentricity of the applied axial load to the depth of the section, e/h, are the two significant factors that affect the probability of failure at a prescribed corrosion period the most.