Investigating Corrosive Environmental Factors and Corrosion Rate to Assess Vulnerable Corrosive Areas of Offshore Bridges

Abstract

In this study, to analyze the corrosive vulnerable members of an offshore bridge, the corrosive environments and corrosion rate were evaluated according to the installation location. The steel box deck bridge was selected as the target bridge for analyzing corrosive vulnerable members, and the corrosive environment and corrosion rate of the stiffened sections were compared. Based on the assessment results of the corrosive environment, varying corrosion rates were observed depending on the installation location of the sections, with the sections located at the bottom of the pylon showing a faster corrosion rate. Furthermore, it was established that structural members with accumulated surface chloride of 50 mg/m2 or more could experience accelerated corrosion, as evidenced by the correlation between the corrosive environment and corrosion rate. The side parts of the sections positioned at the bottom of the pylon received a C4 rating, signifying a higher susceptibility to corrosion than the bottom parts. From these monitoring results, it was confirmed that the relative difference in the corrosion rate of stiffened members, and considering the relative corrosive environments. Considering these differences in the corrosive environments, it is necessary to the maintenance for steel members in offshore bridges.