Equivalent elastic modulus of reinforcement to consider bond-slip effects of coastal bridge piers with non-uniform corrosion

Abstract Coastal bridge piers in marine environments are vulnerable to non-uniform corrosion due to wetting-drying cycles and high chloride concentration of seawater. This paper presents a methodology to analyze the seismic performance of coastal bridges by modifying the elastic modulus of reinforcement, while considering the effects of bond-slip and non-uniform corrosion. Tensile stress-slip relationships of reinforcement with uniform and non-uniform corrosion are first derived. Then, a method to determine the equivalent elastic modulus of reinforcement with non-uniform corrosion is introduced. The proposed methodology is validated based on cyclic test results of bridge pier specimens under uniaxial and biaxial loading actions. Through further numerical simulation, the effects of mass loss ratio and corrosion zone height on seismic performance of coastal bridge piers are examined. Compared to the method of using an interface element, the proposed method of using equivalent elastic modulus of reinforcement is simpler for the numerical simulation of bond-slip for coastal bridge piers. Results showed that the steel-to-concrete interfacial bond behavior slightly influences the peak strength of coastal bridge piers. However, it can significantly reduce the energy dissipation capacity and residual displacement of structural components.