When reinforced concrete (RC) flat plate systems are used as gravity force resisting systems in regions of high seismic activity, they are required to accommodate the seismically induced drifts without jeopardizing their gravity load capacity. The elastic nature of fibre-reinforced polymer (FRP) reinforcement raises concerns about the seismic response of FRP-RC flat plate systems. The present study provides the first attempt to tackle this area.

A pioneer research program was conducted to investigate the feasibility of using FRP reinforcement in slab-column edge connections subjected to simulated seismic loads. The program consisted of three phases: experimental, analytical, and numerical. The experimental phase involved the construction and testing of seven full-scale glass FRP (GFRP)-RC edge connections under simultaneous gravity and reversed-cyclic lateral loads. The test parameters were the flexural reinforcement type (steel and GFRP) and ratio (0.7 and 1.4%), the gravity shear ratio (0.4, 0.5, and 0.6), and the GFRP shear reinforcement type (shear studs and corrugated bars).

In the analytical phase, models predicting the punching capacity of FRP-RC connections from literature were reviewed. Besides the connections tested in the experimental phase, a database comprising 68 interior and 19 edge specimens subjected to gravity loads was compiled and used to assess the models. A universal model capable of predicting the capacity of interior and edge connections subjected to gravity or cyclic loads was proposed.

The numerical phase incorporated the construction and validation of a finite element model (FEM) simulating the seismic behaviour of FRP-RC edge connections. This FEM was used to conduct a parametric study investigating the influence of gravity shear ratio, column size, slab thickness, and flexural reinforcement type and ratio on the seismic response of edge connections.

The results showed that GFRP reinforcement can be used in edge connections subjected to simulated seismic loads. The large elastic deformations of GFRP bars compensated for the absence of yielding. Furthermore, GFRP-RC edge connections without shear reinforcement were able to undergo 1.50% drift ratio if the gravity shear ratio does not exceed 0.5. Moreover, the use of well-anchored GFRP shear reinforcement resulted in a substantial increase in the drift capacity of the connections.