Comparative Numerical Simulation of Damage Propagation Caused by Chloride and Oxygen Diffusion in Reinforced Concrete Slabs

One of the major factors contributing to the degradation of reinforced concrete slabs, especially in bridges and roads, is corrosion due to the diffusion of corrosive ions. All such infrastructure would experience different types of loading, from the moving live load caused by the vehicles to the thermal cycles and ion exposure. These ions can be internally produced due to chemical reactions or introduced to the medium of the structure from outside by spraying the brine and rock salt in the winter. In recent years, different aspects of chloride and oxygen-induced corrosion have been studied through analytical/numerical modeling or accelerated experiments. The problem with this subject is its sensitivity and dependence on many factors. In this paper, numerical simulations have been implemented to display the relative patterns and comparative rate of cracking due to the diffusion of oxygen (in a wet medium) and chloride ions (after brine spraying). This comparative approach can offer a better visual perception to the engineers about the corrosion process in field projects. Based on the results, the aggression of chloride ions in corroding the reinforcement and cracking the concrete medium is much higher than oxygen ions. Thus, the rate at which the corresponding section reaches the critical state is much faster under the attack of chloride ions, leading to a dramatic decline in the service life of infrastructure.