Multiphysics Modeling of Chloride-Induced Corrosion Damage in Concrete Structures

Abstract

This paper presents a computational scheme describing the formation and evolution of cracks in concrete structures due to chloride-induced corrosion in reinforcing or prestressing steel. The scheme accounts for coupled heat, moisture and chloride transport, while phenomenologically describing the kinetics of the electrochemical corrosion reaction in steel, formation of expansive corrosion products, and subsequent formation of stresses and cracks in concrete. Advective and diffusive chloride transport mechanisms are considered. The increase in concrete permeability against moisture and chloride transport due to cracking is considered in the constitutive laws. Novel equations are proposed to accurately describe the expansion of corrosion products. The scheme is calibrated using data from small-scale tests in the literature. Subsequently, it is applied to the simulation of real-life prestressed concrete bridge beams that exhibited corrosion-induced cracking after decades of service. The boundary conditions represent the ambient climate data, obtained from weather stations near the bridges. The analyses reproduce the observed cracking damage and enable the investigation of the validity of modeling assumptions commonly adopted in analytical studies for concrete infrastructure durability. The results also emphasize the significance of cracking on the evolution and spatial distribution of chloride content and on the extent of corrosion.