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Article analysis:

The article titled “Non-uniform rust expansion for chloride-induced pitting corrosion in RC structures” provides a detailed overview of the electrochemical processes involved in chloride-induced corrosion of reinforced concrete structures. The authors employ numerical simulations to analyze the localized corrosion rust accumulation process, and their results show that macrocell corrosion rate may decrease drastically while microcell corrosion rate may not change so much during the gradual initiation process of corrosion around reinforcing steel. The non-uniform rust distribution around steel–concrete interface is found to be mainly caused by macrocell corrosion circulating between upper active and lower passive rebar surface.

The article appears to be well researched and reliable, as it draws on a variety of sources such as laboratory experiments, field experiments, empirical models, analytical simulations, and numerical modeling techniques. Furthermore, the authors provide detailed explanations for each step of their analysis, which makes it easier for readers to understand their findings.

However, there are some potential biases in the article that should be noted. For example, the authors assume that chloride diffusivity DCl (m2/s) is constant throughout the whole corrosion initiation process without considering its dependence on several factors such as relative humidity, type of binder, etc., which could lead to inaccurate predictions of chloride concentration at reinforcement surface. Additionally, they assume a linear distribution of oxygen concentration through concrete cover without taking into account other factors such as temperature or humidity that could affect oxygen diffusion rate. Finally, they do not consider the gradual transition from passive state to active state of reinforcing steel when calculating critical chloride content for reinforcement depassivation.

In conclusion, this article provides an informative overview of chloride-induced pitting corrosion in RC structures and offers useful insights into how non-uniform rust expansion can be simulated numerically. However, there are some potential biases that should be taken into consideration when interpreting its findings.