Flexural Behavior of Pultruded Hybrid Fiber-Reinforced Polymer I-Beams with Bonded-and-Bolted Splice Joints

This paper presents experimental results of double-lap joints of fiber reinforced polymer (FRP) or steel splice plates bonded and bolted to flanges and web of pultruded hybrid I-beams with carbon FRP and glass FRP. Eight large-scale specimens with bonded-and-bolted splice joints and two control beams were tested under four-point static flexural loading. The test results indicated that the double-lap splice joints, which incorporated high corrosion-resistant steel bolts, epoxy adhesive, and FRP splice plates with a grit-blasted surface finish provided an effective solution for joining the hybrid FRP I-beams. The grit-blasted surface finish of the FRP splice plates and the epoxy adhesive contributed to improving the joint stiffness and strength. Before debonding occurred, the stiffness of the bonded-and-bolted splice joints was dependent mainly upon the strength of the epoxy adhesive and the bonding surface of the splice plates, while the ultimate load and failure mode of the joints was governed by the number and strength of bolts. The specimens with failures in the splice connections showed more ductile behavior than specimens with failures beyond the connections. This difference is attributed to the slippage of the splice connections.