Corrosion-induced cracking: experimental data and predictive models

The present study describes an accelerated corrosion testing program comprising eight reinforced concrete (RC) specimens to simulate reinforcement corrosion of a section of a typical RC bridge deck. A constant corrosion rate of approximately 100 mA/cm2 was applied to accelerate the corrosion process in chloride contaminated concrete. Experimental results are compared with existing crack initiation and propagation models. A new empirical model to predict the time to excessive cracking for RC structures subjected to corrosion is proposed for cracks up to 1 mm in width by considering concrete quality and cover as influencing variables. The model is also able to account for time-variant corrosion rates and the effect of a high rate of loading often associated with extrapolating accelerated corrosion test results to real RC structures. It was observed that the accuracy of the predictive model for crack initiation will not significantly influence the time to excessive cracking. The time to excessive cracking is most influenced by the correction factor for rate of loading