State-of-the-art review on axial behavior of FRP-concrete-steel double-skin tubular columns

Abstract

Over the last twenty years, there has been considerable focus on the use of fibre-reinforced polymer (FRP) composites as confinement substances. The hybrid double-skin tubular column (DSTC) represents an innovative construction approach, comprising an external fibre-reinforced polymer (FRP) tube, an inner steel tube, and a concrete infill. These columns are primarily designed to offer corrosion and seismic resistance, DSTCs have gained popularity in bridges and offshore structures applications. This paper aims to provide an unbiased evaluation of the experimental research efficiency of hybrid FRPconcrete- steel double-skin tubular columns subjected to axial compression while exploring various critical parameters, as well as numerical and analytical studies. The examined parameters include the buckling behavior of the inner steel tube, the diameter of the inner steel tube, FRP tube thickness, the orientation of fibres, failure modes, axial load-strain behavior, FRP hoop rupture strain, concrete strength and concrete type, the interaction between steel and FRP tubes, filling the inner steel tube, stiffened DSTCs, and cross-sectional form. The review findings emphasize the importance of future research in areas such as non-circular column members, the use of natural fibres for the outer FRP tube, and numerical and analytical studies. These insights are valuable for researchers, practitioners, and decision-makers involved in designing, constructing, and retrofitting efficient and resilient structures as hybrid DSTCs