Abstract: Concrete structures are subject to corrosion under the marine environment, which reduces their service life. In this paper, the authors study on the rules of chloride iron ingression in concrete at different positions and within different durations under the marine environment, by testing on the chloride iron content in the samples that are exposed to corrosion at different positions and within different durations. Conclusions drawn are as follows: 1) Within the same corrosion duration, the chloride iron contents in the concrete decrease in the order from the concrete underwater, to the concrete in the tidal zone and finally to the concrete in the air zone, and the appearance defect of the concrete in the tidal zone is more serious than that underwater; 2) At the same corrosion position, the chloride iron content in the concrete increases with the corrosion duration, decreases with the depth and stabilizes finally; 3) Within the same corrosion duration and at the same corrosion position, the chloride iron corrosion resistance capability of concrete decreases with the increasing of the water/cement ratio of the concrete.

Key words: marine environment, concrete, chloride iron, corrosion