Repair Method and Finite Element Analysis for Corroded Gusset Plate Connections Bonded to CFRP Sheets

AbstractIn steel truss bridges, severe damage due to corrosion at gusset plate connections has been widely reported. This study investigated the effectiveness of a repair method using carbon-fiber-reinforced plastic (CFRP) sheets for corroded gusset plate connections. Loading tests were conducted with a model approximately 50% of the size of actual gusset plate connections and a corrosion level of approximately 50% of the gusset plate thickness. Further, loading tests were carried out by varying the area, direction, and location of the bonded CFRP sheets. Results showed that the proposed repair method recovered the load-carrying capacity and improved the deformation performance of the corroded gusset plate connections. Three-dimensional finite element (FE) analyses, which considered the nonlinear properties of materials, anisotropic performance of CFRP sheets, and bond-slip model of the polyurea putty layer inserted between the corroded gusset plate and CFRP sheets, were implemented to validate the experimental results. By varying the bond-slip properties of the polyurea putty layer within the fluctuation range of measured data, this study accurately reproduced the experimental results and clarified the polyurea putty layer’s influence on the load-carrying capacity, deformation performance, and failure behavior of the corroded gusset plate connections bonded to CFRP sheets.