Effect of accelerated time-dependent corrosion on reinforcement concrete and ultra- high performance concrete: Finite element method analysis

Abstract

In this study, finite element analysis using Ansys software was employed to evaluate the bond stress-slip behaviour of corroded steel bars in reinforced concrete structures. The corrosion specimen model was fabricated in accordance with the ACI 440.3R standard, comprising a 580 mm long steel bar with diameters of 12, 16, and 20 mm, positioned at the centre of a 200x200x200 mm concrete block with varying compressive strengths of B25, B35, and B45, respectively. Following fabrication, the specimen was immersed in a tank containing a 3.5% NaCl saltwater solution. Subsequently, the electrochemical corrosion process, based on Faraday's law, was applied to accelerate corrosion. The concrete and steel bar elements were modelled using SOLID65 and LINK180, respectively. The elasto-plastic behaviour for both concrete and steel bars, along with the cohesive zone model (CZM) for the interface bond between the bar, whether corroded or not, and the concrete, demonstrated good agreement with experimental results. The experimental model was precisely constructed using Ansys software. The results obtained from finite element analysis exhibited high accuracy compared to the experiment, with a maximum error of only 4.5%. The finite element method (FEM) can entirely replace the experiment in analysing the adhesion force between concrete and steel. The constitutive models of materials could be applied for parametric studies in future work.