Physical Model–Based Failure Prediction of Concrete Stormwater Pipes Subjected to Rebar Corrosion

This paper proposes a physical model–based approach for predicting failures of concrete stormwater pipelines considering corrosion of reinforcing steel bars. Three failure modes, namely flexure failure, shear failure, and cracking failure, were examined over the service life of stormwater pipes based on a widely accepted corrosion model for rebars in concrete. Random stochastic processes were utilized to approximate the load effects in the three failure modes, and the first passage probability theory with the exponential autocorrelation function was employed to conduct the probabilistic analysis over the lifetime of the stormwater pipes. A worked example was presented to demonstrate the application of the proposed approach and evaluate the effect of rebar corrosion on the failure probability of a stormwater pipe. It was found that the correlation lengths of the stochastic processes play a considerable role in the failure probabilities of each failure mode and the system. It was also found that the probability of system failure reduces with an increase in concrete cover thickness and a decrease in water-cement ratio of the concrete.