Bidirectional GFRP-Composite Connections between Precast Concrete Wall Panels under Simulated Seismic Load

Glass fiber-reinforced polymer (GFRP) composites offer several advantages over loose-plate steel connections when used in vertical joints between concrete wall panels as a connector. Advantages include resistance to corrosion, higher tensile strength, and the ability to conform to uneven surfaces. The performance of continuous and intermittent GFRP composite connections between precast concrete wall panels under simulated seismic loads is investigated using six specimens. Each specimen was comprised of two precast concrete wall panels connected with a GFRP composite system. The laminate in the system consisted of bidirectional GFRP sheets applied in a wet layup configuration over a layer of epoxy–putty adhesive. The connection was applied on one side of the wall panels to meet architectural and construction demands. Cyclic shear was introduced to the GFRP composite connection through in-plane horizontal quasi-static cyclic loads, while horizontal and vertical constraints at the bottom and top corners of each specimen were engaged. The variables in the research are the presence of epoxy–putty adhesive in the seam between the wall panels, the percent of seam height covered with bidirectional GFRP composite, and the use of GFRP spike anchors. The presence of epoxy–putty adhesive in the seam significantly increased the horizontal load capacity of the GFRP composite connection. The use of GFRP spike anchors increased the horizontal load, horizontal displacement, shear transfer, and energy dissipation capacity of the GFRP composite connection. The GFRP composite connections performed very well and could be used in the seismic retrofit of existing connections between precast concrete wall panels.