Unidirectional GFRP composite connections between precast concrete wall panels under simulated seismic loads

A method of connecting precast concrete walls with Glass Fiber Reinforced Polymer (GFRP) composite sheets is investigated. The method can be used either as a seismic retrofit of existing welded steel plate connections or in new construction. The specimens consisted of two precast concrete wall panels connected with either two or four layers of unidirectional GFRP composite sheets. Eight specimens were subjected to quasi-static cyclic loads to explore the effect of the following variables on the connection capacity: concrete surface preparation; application of surface pressure to the GFRP laminate; number and orientation of GFRP composite layers; and use of carbon fiber reinforced polymer (CFRP) spike anchors. The performance of the composite connection was acceptable in terms of lateral load, lateral displacement, and shear transfer capacity. Application of surface pressure during curing of the GFRP laminate and the use of CFRP spike anchors improved the lateral load and displacement capacity of the composite connection significantly. An empirical expression is proposed to determine the capacity of the composite connection.