Corrosion induced failure mode in reinforced concrete beams based on experiments and finite element predictions

Abstract

Abstract

Reinforcement corrosion is a primary cause of durability loss and structural degradation in reinforced concrete (RC) structures. This study experimentally investigated how uniform and non‑uniform reinforcement corrosion affect the flexural capacity, stiffness, and ductility of RC beams with concrete strengths between 25 and 35 MPa, under two levels of accelerated corrosion current density. A series of beams were subjected to accelerated corrosion and subsequently tested under four‑point bending. Results reveal that high‑rate corrosion produces brittle bond splitting failure with about 60% capacity loss at a corrosion degree of 0.15 (15% mass loss) while the midspan deflection at peak load decreased from 4.97 mm to 2.24 mm. lower corrosion current leads to progressive bond deterioration with only about 15% capacity loss but deflection increases exceeding 130% in 15% mass loss. Non‑uniform corrosion location effects are comparable in importance to corrosion severity: midspan damage reduces capacity but enhances ductility, while support‑region damage triggers a brittle shear‑dominated response. Three‑dimensional finite element models in Abaqus, incorporating cohesive interface elements and corrosion expansion via calibrated radial pressures (4-7 MPa), reproduce experimental load-deflection curves within about 5% error in peak load and 10% in deflection. Comparative analyses indicate that direct radial‑pressure modeling outperforms the thermal‑analogy method for representing corrosion‑induced expansion. These findings suggest a validated framework for assessing residual flexural capacity and stiffness of corroded RC beams and for supporting prioritization of retrofitting interventions.