Hybrid FRP-concrete-steel tubular members

Hybrid fibre-reinforced polymer (FRP)-concrete-steel (FCS) tubular members are an emerging type of structural members. These hybrid members involve the use of an external FRP tube as a confining device and a corrosion-resistant skin, a concrete infill, and encased steel reinforcement of various forms (e.g. steel bars, a steel section, or a steel tube). In such members, the FRP tube is generally designed to possess only a small axial stiffness so that its confinement effectiveness on the concrete is not compromised by buckling due to substantial axial compressive stresses, while the potential buckling of steel reinforcement is well restrained by the confined concrete, leading to excellent structural performance. This paper offers an overview of existing research on hybrid FCS tubular members before providing a summary of several novel forms of such members recently developed at the University of Wollongong.