Numerical and Experimental Analysis of the Impact of Cracking and Chloride Concentrations on Corrosion in Steel-Reinforced Concrete

This study investigated the effects of cracking and varying levels of chloride exposure concentrations on the chloride penetration and corrosion performance of reinforced concrete beams subjected to mechanical loading conditions and wet and dry cycles through a time-dependent multiphysics simulation framework. Three-dimensional finite-element models were simulated considering load-induced cracking. In the models, chloride exposure concentrations were considered, and three crack widths were simulated for each chloride concentration. Material transport properties such as chloride and oxygen diffusion parameters as well as concrete resistivity were updated at each time step based on wet and dry conditions and damage development. The computational framework was used to understand experimental behavior of cracked beams subjected to varying chloride concentrations. The simulation results show that chloride concentration in the concrete at the same distance to the exposure surface increased as crack widths increased, matching experimental trends. Numerical results followed experimental behavior where corrosion propagation was faster at higher chloride ponding concentrations. The simulation results also indicated that surface chloride concentrations and crack widths above certain thresholds have limited influence on corrosion propagation. The effects of wet and dry cycles on the corrosion performance were also explored. The numerical framework discussed provides a robust method to analyze deterioration processes of reinforced concrete infrastructure subject to various loading and exposure conditions in a time-efficient manner. Such a framework can be used to understand chloride-induced corrosion behavior in reinforced concrete structures and be applied for service life assessment of a reinforced concrete system.