Empirical assessment and refinement of corrosion distribution models in the perimeter of corroded steel rebar subjected to chloride ions attack

Predicting the volume of corrosion products (CP) and their distribution in the steel rebar periphery will play an essential role in estimating the expansion stresses and, consequently, the behaviour of concrete in extreme environmental circumstances. In this respect, using the outcomes of performed laboratory studies, an attempt has been made to evaluate and compare the accuracy of the existing models for forecasting the thickness of CP. To this end, by applying the statistical analysis to predicted values, the error margin of the intended models in comparison to empirical observation has been computed. In addition, given that the studied models are mainly focused on estimating the corrosion product distribution (CPD) on the concrete cover, a research effort has been made to upgrade the models to estimate the corrosion distribution in the concrete core side. Based on the results obtained, it can be concluded that the modified Zhao model is the best-fitted model among the reviewed models, and performed refinement on this model could estimate the results more accurately. Furthermore, an empirical relationship for estimating the coefficient of CP expansion was introduced. •The accuracy of nonuniform based corrosion distribution models was empirically assessed.•The Zhao model provides the best results for prediction of corrosion product distribution.•A novel empirical relation for calculating corrosion products' expansion coefficient is submitted.•The proposed modification could predict the CP distribution in the concrete core side.