Deterioration of static mechanical properties of RC beams due to bond damage induced by electrochemical rehabilitation

•Deterioration of static mechanical properties of RC beam after ER is investigated.•A flexural stiffness model for RC beam after ECE and BIEM is established.•The quantity range of electric charge when implementing ER is proposed. Electrochemical rehabilitation (ER) techniques are very efficient and non-destructive methods to improve the durability of existing concrete structures. However, the induced bond damage between steel bar and concrete will affect the mechanical properties. In order to investigate the effect of ER on the static mechanical properties of concrete structures, three types of tests after electrochemical chloride extraction and bidirectional electromigration were carried out in this study. Based on the desired constitutive models, finite element analysis was then used to verify the effect of bond damage on the static mechanical properties of RC beams. Results showed that the spacing and width of cracks both increased with increasing current density and duration. The yield bearing capacity of beams decreased by 20% when the electrical parameters were 3 A/m2 for 4 weeks and 5 A/m2 for 2 weeks. Careful investigation with experiments, finite element simulations, and theoretical explanation demonstrated that bond damage was the main reason. As a result, a modified flexural stiffness model of concrete beams considering the electrification parameters was established. Combined with data from the relevant literature, the optimal quantity of electric charge for ER balancing chlorine removal efficiency and flexural stiffness was finally determined as 500–1400 Ah/m2.