Glass Fiber Reinforced Polymer Composite Connection Between Concrete Wall Panels Under Cyclic Shear

Abstract

Glass fiber reinforced polymer (GFRP) composites offer several advantages over welded steel plate connections when used in the connection of vertical joints between concrete wall panels. These advantages include resistance to corrosion, higher tensile strength, and ability to conform to uneven surfaces. In the present research, push-off tests and wall tests were carried out to understand the behavior of GFRP composite connections between concrete elements. Push-off tests were performed to understand direct shear transfer capability when using different concrete surface preparation methods. Wall tests were performed to understand the behavior of different GFRP composite connections under simulated seismic loads, or cyclic shear. Ultimately, the GFRP composite connections displayed little ductility, but demonstrated outstanding displacement and load capacity. Push-off tests were performed for a GFRP composite connection between two L-shaped concrete elements. Each of the six groups of surface preparation included three specimens each, resulting in eighteen push-off specimens. A compressive load at the top and bottom of the specimen introduced direct shear in the GFRP composite connections. Specimens with concrete surface preparation using only a high-pressure wash demonstrated superior load and displacement capacities. Wall tests were performed for GFRP composite connections between two concrete panels, with the connection only applied on one side of the joint. A lateral load was applied at the top of the wall pair, while restraining the horizontal movement at the base and the vertical movement of each panel, inducing shear in the connection. Tests from group one (using unidirectional lamina) included eight specimens and concluded that the use of application pressure and CFRP anchors significantly increased load, displacement, and shear capacity of the GFRP composite connection. Also, fewer layers and CFRP anchor use increased the amount of energy dissipated during simulated seismic loads. Tests from group two (using bidirectional lamina) included six specimens and concluded that the use of GFRP anchors significantly increased load, displacement, and shear capacity of the GFRP composite connection. Also, the use of epoxy-putty adhesive had a significant effect on the load capacity; and full seam coverage and GFRP anchor use increased the amount of energy dissipated during simulated seismic loads.