Fatigue performance of composite-steel injected connectors at room and elevated temperatures

The integration of Glass Fibre-Polymer composite (a.k.a. GFRP) deck panels in bridge infrastructure is hindered by lacking a robust connection technology. A promising bolted connection, utilising injected steel reinforced resin (iSRR) material, has demonstrated lower creep deformation and sustained significantly more shear load cycles than conventional bolts. Nonetheless, the production and testing conditions in all prior experimental campaigns followed idealized lab set-ups. This study bridges the gap between laboratory conditions and the challenges arising during connector's fabrication under representative conditions, coupled with cyclic load testing at room and elevated temperatures. The iSRR connectors design is modified and tested in actual composite sandwich web core panels, revealing excellent fatigue performance. The statistical analysis yielded F-N curves for shear performance of the connectors that can be used in the design. The slopes of the F-N curves of − 6.6 and − 5.8 were found at room and elevated temperatures, respectively. Finally, with post-cyclic static tests displaying significant connectors’ residual stiffness, resistance, and ductility, the research provides a step forward in enabling the integration of glass fibre composite deck in infrastructure.