Time-Dependent Reliability Assessment of Corrosion Affected Reinforced Concrete Structures

Corrosion of reinforcement is the most widespread and predominant cause of deterioration of reinforced concrete structures exposed to an aggressive environment. It is responsible for the loss of strength and serviceability of these structures by creating cracking in the concrete cover and reducing bond strength and hence the performance of the structure over time. A failure in the structure is considered to occur when the resistance of the structure drops below its acceptable limit. Deterioration arising from reinforcement corrosion is generally uncertain and non-decreasing therefore a stochastic process such as the gamma process could be useful to evaluate the structural reliability. This paper presents a stochastic gamma process model to evaluate the probability of failure in serviceability and in ultimate load capacity associated with the corrosion process in reinforced concrete structures. The deterioration and resistance of the structure are assumed to be a stochastic process, and the structure is considered to have failed when its resistance reaches its allowable limit. The results from the illustrative example show that the proposed approach can effectively predict the deterioration and survival capacity of corrosion damaged reinforced concrete structures.