Abstract: Compared with the roads and reinforced concrete bridges inland, roads and bridges in coastal region is easier to be destroyed which makes its durability lower because of chloride ion erosion. Steel structures in coastal roads and bridges have been corroding by chloride ion for a long time which caused fast collapse after rotten and aged steel appeared. For coastal region, therefore, every year, a large amount of money is used to reinforce and maintain the roads and bridges, which brings serious economic losses and in a way affects the social environment in coastal region.

Keywords: Coastal Region; Concrete; Steel; Remaining Service Life.