Experimental and numerical study on behavior of channel-shaped GFRP perforated rib shear connectors

Abstract

Effective shear connections at the interface of Pultruded Fiber Reinforced Polymer (FRP) - concrete hybrid system play a pivotal role in maintaining the structural integrity of composite structures. In this vein, this study presents a comprehensive investigation-encompassing experimental, analytical, and numerical approaches-into the shear behavior of a novel, channel-shaped Glass Fiber Reinforced Polymer (GFRP) perforated rib shear connector (GPRSC), designed for hybrid GFRP-concrete systems. Ten full-scale push-out specimens were tested to investigate the effect of the inclusion and diameter of the perforating rebar, the diameter and the spacing of the perforated hole, and concrete strength on the shear behavior of the channel-shaped GPRSC. The push-out tests highlighted two distinct failure modes: (i) shear failure of concrete dowel, and (ii) debonding failure of interface. To supplement these findings, numerical models were established that incorporate 2D Hashin's theory to account for laminate damage of GFRP. This allowed for an in-depth examination of the load transfer and failure mechanisms of the channel-shaped GPRSC. Finally, calculation formulae for shear resistance and load-slip relationship were proposed. A comparative evaluation between experimental results and values predicted by these formulae yielded a reasonably strong correlation. This research constitutes a significant advancement in the field of hybrid GFRP-concrete systems.