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

摘要

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.