COMPARISON OF ELECTROCHEMICAL ACCELERATED CORROSION AND CORROSION IN NATURAL ENVIRONMENT

Different corrosion products are formed on the steel bars when RC structures are subjected to different environmental conditions, and different kinds of rust products have different volume expansion. The bigger the expansion coefficient, the smaller the quantity of corrosion-products to crack the concrete cover. Therefore, the quantities of corrosion products to crack the concrete covers subjected to various environments are different. Although the impressed current technique to accelerate corrosion is used by many researchers in laboratories, the results are not accurate because the corrosion products formed during the accelerated test are different from the ones formed in natural environments. In this paper, the suitability of the impressed current technique of accelerating the corrosion crack to simulate corrosion in the natural environments is discussed, and a new method to correct the cover cracking results of acceleration test is proposed according to the volume expansion cofficients of corrosion products. The impressed current technique is confirmed to be an effective and quick method of accelerating corrosion, and can simulate corrosion crack under different environment conditions with correction proposed in this study.