3D Numerical Analysis of Corrosion Effects on the Steel-Concrete Interface

Reinforced concrete has established itself as the standard material in modern construction, deriving its performance from the synergy between concrete's compressive strength and steel's ability to resist tensile forces. However, this durability is challenged by the intrinsic porosity of concrete and the harshness of outdoor environments, which expose the reinforcing bars to the risk of corrosion. To mitigate this phenomenon, designers optimize cementitious mixtures and increase cover thicknesses. Yet, despite these physical barriers, the effectiveness of these protective measures is often compromised by natural hazards and the inevitable cracking of structures in service. Today, reinforcement corrosion has emerged as the major pathology in civil engineering, constituting the primary cause of premature deterioration and a significant challenge to infrastructure durability. Based on this observation, this research focuses on the impact of corrosion on the bond between reinforcing steel and concrete cover in reinforced concrete structures, a fundamental parameter for the integrity of these structures. In this thesis, a three-dimensional numerical model of a 300×100×100 cm³; reinforced concrete beam was developed in ABAQUS to simulate the effect of uniform corrosion by simulating 30 corrosion levels under the same pull-out force. The results highlight an overall reduction in bond strength as the degree of corrosion increases, while identifying specific thresholds where a slight increase in interfacial adhesion can temporarily enhance the bond between the two materials. In a second step, a numerical model of a reinforced concrete cube with different corrosion rates (between 0.25% and 3.5%) was developed, using different lengths of the portion embedded in the concrete (20 mm, 40 mm, 60 mm, and 80 mm), to determine its effect on the bond between the concrete and the steel. Third, a non-destructive evaluation methodology based on Lamb wave propagation was implemented via numerical analysis using ABAQUS software.