Flexural performance of composite prefabricated concrete sandwich panels with pultruded square GFRP tubular shear connectors

Abstract

The flexural performance of composite prefabricated concrete sandwich panels (PCSP) with pultruded square glass fibre-reinforced polymer (GFRP) tubular shear connectors was examined in this study. Five PCSPs were tested under a static four-point bending load to reveal the influence of the direction and spacing of shear connectors, and thickness of the insulation layer on their flexural performance. All the tested panels exhibited flexural failure mode caused by vertical cracks on the bottom and top concrete wythes along the length of the panels. In addition to flexural failure, panels with combined tension-compression connectors showed punching failure of the compression connectors through the bottom concrete wythe. A panel with tension connectors showed 43 % and 26 % higher peak load-bearing capacity than the panel with straight and combined tension-compression connectors, respectively. The reduction in the spacing of shear connectors had a negligible influence on the strength of the panel. The cracking and ultimate strengths of the tested panels were theoretically estimated, showing a reasonable match with the experimental results. Moreover, the evaluation of the degree of composite action (DCA) in the panels revealed that the panel with tension connectors can achieve almost full composite action in yield and peak loading stages.