Modeling and evaluation of deterioration of corroded RC columns

Abstract:

To understand the influence of non-uniform corrosion on the performance of RC frame columns, the corrosion crack propagation and the distribution of corrosion products were studied. The evaluation model of the corrosion rate of longitudinal reinforcement based on the corrosion crack width was established. By introducing the corrosion influence coefficient, an equivalent strength model of corroded longitudinal reinforcement was proposed, considering non-uniform corrosion. Based on the existing test results, the relation between the corrosion rates of longitudinal reinforcement and stirrup was analyzed, and the correlation model of the corrosion rates of stirrup and longitudinal reinforcement was constructed. A concrete model confined by corroded stirrups was proposed based on the Mander model. Calculation results show that the corrosion of steel bars significantly decreased the strength of the concrete and the steel bars, and the non-uniform corrosion of the steel bars affected the mechanical properties of the steel bars. On the basis of OPENSEES and the proposed material model, a numerical model of corroded RC frame columns was established. Given the previous test data, the models proposed in this study were verified. Results show that the models achieved high accuracy, the evaluation model of corrosion rate could reflect the influence of involving factors, and the research results can be used to evaluate the performance of existing concrete structures.