Experimental and Numerical Evaluation of the Sandwich Panel Repair Method for Corrosion-Damaged Bridge Girders

Steel girder ends in bridges can be susceptible to corrosion damage from deicing salts, water, and other contaminants that leak from failed deck expansion joints. When corrosion becomes significant, it can decrease the sectional properties of steel girder ends and eventually reduce structural resistance against bearing and shear. Conventional methods that are typically used to repair corrosion-damaged girders require a substantial amount of time and resources to complete and often cause public inconvenience due to traffic lane closures. Thus, there is a critical need for practical, rapid, and cost-efficient repair solutions suitable for implementation by local DOT maintenance teams. The main concept of the proposed Sandwich Panel repair method is to encase the corroded region in a filler material, such as cementitious grout or an alternative, and reinforce it with threaded rods. To expedite installation and eliminate the need for formwork removal, two bent thin steel plates installed on both girder sides serve as stay-in-place formwork. Therefore, this repair method eliminates the labor-intensive steps of jacking, welding, and formwork disassembly, making it more cost-effective and less time-consuming. The structural performance of the Sandwich Panel repair method was validated through five large-scale experimental tests, considering parameters such as (1) threaded rod layout, (2) filler material, and (3) support conditions. This study primarily focused on the repair of steel girders without full-depth stiffeners, whose bearing strength is more sensitive to web deterioration. The repair successfully restored, and even exceeded, the design web crippling capacity of the W24 × 68 steel girder, calculated in accordance with AASHTO LRFD methodology. A complementary parametric study was conducted using finite-element models that were benchmarked against experimental results and validated the efficacy of the repair.