Time-variation full process mode of steel bar corrosion in concrete

This paper discusses the corrosion rate variation of reinforcing steels in concrete in constant climate environment. The corrosion current density of steel bar in concrete under a constant climate environmental condition and chloride attack. The results indicate that the corrosion rate (corrosion current density) of the steel bars is time-dependent during a corrosion process, and the time-dependent process can be divided into six phases in the full lifetime. The results also show that the effects of the concrete strength and the electrical resistivity of the concrete on the variation of the corrosion rate. This study conducts the mechanism analyses about the test results based on the microstructure of the interfacial transition zone (ITZ) between the steel bars and the concrete at different corrosion levels. The growth of the corrosion layer and the corrosion cracking are the main factors influencing the corrosion process. The time-variation mode of the corrosion rate of steel bars in full process is developed.