Abstract: Based on the electrochemical theory, numerical models are developed to reveal the effect of crack width on the corrosion rate of carbon steel and stainless steel reinforcements in concrete, considering the effect of cracks on chloride ion and oxygen transportation in concrete and the effect of oxygen on steel corrosion process. Experimental tests are conducted to verify the accuracy of numerical simulations, and the parameter sensitivity of the simulations is examined. The results show the anodic polarization process and oxygen supply are two dominating factors of the steel corrosion rate. The occurrence of cracks moves up the critical time for steel bars to transform from passive to corrosive, and also affects the corrosion rate of carbon steel in the stable corrosion stage. Reducing the crack width and chloride diffusion coefficient can significantly limit the steel corrosion rate. Compared with carbon steel, stainless steel shows higher corrosion resistance in harsh erosive environments.

Key words: crack width of concrete, steel corrosion, corrosion rate, stainless steel reinforcement, numerical simulation