A lumped plasticity model for corrosion-damaged reinforced concrete columns

Chloride-induced corrosion is one of the most important causes of the strength degradation of reinforced concrete (RC) bridges. As the piers of RC bridges are important elements for sustaining lateral loads, corrosion of pier columns may lead to significant degradation of the structure. It is thus necessary to have an appropriate evaluation technique to assess the effect of corrosion on the behaviour of RC columns. Numerical modelling approaches based on a concentrated plastic hinge can predict structural behaviour rapidly and with acceptable accuracy, and are highly regarded by engineers. In this study, a numerical approach was conducted to develop an empirical lumped plasticity model (LPM) for corroded RC column elements. In this study, 13 440 RC column specimens, including corroded and uncorroded columns of both rectangular and circular cross-section, were analysed under monotonic and cyclic loading. The LPM was extracted based on regression of the results of cyclic and monotonic analyses. The calibrated model, valid for corroded and uncorroded columns, was assessed using experimental results and numerical models with data out of the range of those used in the parametric study and was found to have high accuracy. The newly developed plastic hinge model can be used to model and analyse corroded bridge columns rapidly. The results are appropriate for use in further assessments such as fragility or rehabilitation analyses.