Study on the Robust Bridge Deck Pavement System Based on Horseshoe-Shaped Shear Keys

Traditional concrete bridge decks often incorporate steel mesh to ensure connection and prevent cracking. However, the cracking in the connecting layer, low bond strength, misalignment of steel mesh, and settling at the bottom often appear. In this study, fiber-reinforced concrete was used for the bridge deck overlay, and a horseshoe-shaped shear key was employed to connect it with the beam body, forming a robust composite bridge deck system. By optimizing the concrete composition and interface bonding methods within the system, a comprehensive investigation was conducted into the compressive and splitting tensile strengths of different composite systems. The findings showed that the horseshoe-shaped shear key enhances the splitting tensile strength of the composite structural system while maintaining its compressive strength, ensuring a certain level of structural integrity during failure. As the strength grade of the steel fiber-reinforced concrete in the deck overlay increases, the compressive and splitting tensile strengths of the composite system initially rise and then stabilize, with C40 being the optimal strength grade for the deck overlay concrete. Furthermore, the overall performance of the deck overlay concrete with steel fibers is superior to that with the POM and PP fibers. The application of the YJ-302 interface bonding agent at the connection between the deck overlay and the beam body concrete further enhances the mechanical properties of the composite system.