Experimental evaluation of precast concrete sandwich wall panels with steel–glass fiber–reinforced polymer shear connectors

Abstract

A new shear connector is proposed in this article. The shear connector is made of steel–glass fiber–reinforced polymer material. Twelve full-scale precast insulated concrete sandwich panels were tested under flexure to analyze their flexural behavior subjected to pressure. The test program was composed of eight sandwich panels with steel–glass fiber–reinforced polymer connectors and four panels for comparison that were panels using stainless steel truss connectors, pure glass fiber–reinforced polymer pin connectors, and no connectors, respectively. Their load–deflection relationships, load–slip relationships, concrete strain profiles along the wythes cross section, as well as the strains in the steel–glass fiber–reinforced polymer W-shaped connectors were investigated in this article. The panels exhibited a composite action in terms of strength exceeding 85% with steel–glass fiber–reinforced polymer connectors and 40 mm insulation thickness. In addition, the other panels with more than 40 mm insulation layer and different diameter connectors only exhibited 26%–62% composite action. When evaluating the degree of the composite action in terms of stiffness, all sandwich panel values ranged from 6% to 26%. But the compared specimens with pure glass fiber–reinforced polymer connector and smaller diameter steel truss connector had lower level composite action less than 10%. Reasonable design of steel–glass fiber–reinforced polymer W-shaped connectors may provide high composite action for panels and prevent the strength from dropping rapidly due to the steel inner core in the connectors.