Behavior of FRP-HSC-steel tubular columns under axial compression: A comparative study

Abstract

In this study, the compressive behavior of FRP-concrete-steel double-skin tubular columns (DSTCs) and double-tube concrete columns (DTCCs) with HSC and NSC, as well as the concrete-filled steel tubular (CFST) columns and concrete-filled FRP tubular (CFFT) columns with HSC and NSC, were comprehensively studied and compared, with the CFST columns and CFFT columns working as the reference specimens to better investigate the failure mechanism of DSTCs and DTCCs. The failure mode, load-deformation characteristics, dilation behavior, strain distribution in GFRP and steel tube were presented and analyzed. In addition, the failure mechanisms, axial stiffness and ductility, composite effect (in terms of load-carrying capacity) have been compared and discussed in depth in this paper, based on which a design approach of the DSTCs and DTCCs using HSC can be developed in the future. It was found that the composite effect may be found in DTCC columns but not in the DSTCs due to the effect of local buckling of steel tube in the latter.