Repair method and residual bearing strength evaluation of a locally corroded plate girder at support

There is growing interest in the maintenance and repair of bridges according to the increase in their service time. Many corrosion problems have especially been reported in plate girder bridges in support regions because of their high moisture level due to the bad air circulation, sediments, deposition, rain water, and antifreeze penetration in the drainage-type expansion joint. In this study, CFRP repair of a plate girder with localized corrosion at its support was proposed, and this method was used to repair the locally corroded plate girder around its support to examine the applicability and effectiveness of the corrosion repair method using CFRP. FE analysis of the corroded plate girder model was carried out to clarify the residual bearing strength and failure mode due to the localized plate girder corrosion in the web and stiffener at the support region. The application of the CFRP repair method to the plate girder bridge with local corrosion at its support showed that such method can be useful for corroded bridges due to its rapid and simple application and the stress level improvement on the repaired corroded surface on account of the sectional reinforcement effect of the CFRP repair and the prevention of the corrosion progress in the plate girder. The evaluation of the residual bearing strength of the plate girder with local corrosion at its support showed that such strength was affected more by the corrosion related to the stiffener than by the local web corrosion at the support. Therefore, to prevent local corrosion of a plate girder at its support, the corrosion ratio of the stiffener must be considered more than that of the web, and a corroded stiffener must be repaired or reinforced ahead of a corroded web.