Ultra-High Performance Concrete (UHPC) bridge decks have been extensively adopted in steel bridge engineering owing to their significant advantages, including light weight, high load-bearing capacity, wide applicability, and ease of construction. However, field investigations reveal that distress in composite deck systems often originates in the asphalt layer. This is mainly due to insufficient bonding between the UHPC and asphalt layers, which can result in asphalt overlay issues such as rutting, cracking, and interlayer slippage. In this study, the interfacial mechanical properties of four types of bonding layers in UHPC - asphalt composite structures were investigated through experimental tests and numerical simulations. Oblique shear, direct shear, and pull-off tests were systematically performed to evaluate bonding performance under both ambient (25 degrees C) and elevated (60 degrees C) temperature conditions. Based on the experimental outcomes, the epoxy resin and crushed stone bonding layers were selected for further numerical simulation analysis. The results indicate that the crushed stone bonding layer exhibits excellent shear strength (0.59 MPa at 25 degrees Cand 0.36 MPa at 60 degrees C), whereas the epoxy resin bonding layer (0.46 MPa at 25 degrees C and 0.30 MPa at 60 degrees C) demonstrates superior interfacial load-transfer capacity. The findings of this study offer theoretical support for the design and engineering application of UHPC- asphalt steel bridge deck pavements.
Adhesive bonding is widely used to assemble composite parts in modern manufacturing industries to reduce the drawbacks associated with mechanical fastening. The main aim of the current research is to improve the shear strength and fundamental natural frequency of co-cured GFRP composite joint by incorporating graphene nanoparticles (GNPs) into the adhesive. The UV/O-3 functionalization was carried out with GNPs to improve the interfacial bonding. The experimental results revealed that the incorporation of 0.5 wt.% TGNPs in epoxy adhesive enhance the tensile strength by 49% and shear strength by 47% compared to plain epoxy. Fractographic analysis confirms a transition from adhesive to cohesive-dominated failure, indicating enhanced interfacial bonding and crack resistance. Furthermore, vibration analysis demonstrates an increase in natural frequency due to improved interfacial stiffness and efficient stress transfer across the adhesive layer. Overall, UV/O-3 functionalization of GNPs enhanced the interfacial bonding behavior of the adhesive and joint performance. The present findings provide a viable pathway for advanced composite bonding applications that demand enhanced mechanical reliability. The infographic described that UV/O-3-functionalized graphene nanoparticles were incorporated into epoxy adhesive used in co-cured GFRP single-lap joints. Also, the Enhanced nanoparticle dispersion and interfacial bonding improved load transfer, promoted crack deflection and bridging mechanisms, and significantly increased the tensile, shear, and dynamic performance of the bonded composite joints. [GRAPHICS]
