Experimental study on the behavior of CFRP-high strength concrete-steel double skin tubular columns subjected to axial compression

Abstract

This paper discusses the findings of an experimental investigation into the axial compressive behavior of fiber-reinforced polymer (FRP)-concrete-steel double-skin tubular columns (DSTCs) made using high-strength concrete. DSTCs are composite columns that consist of an inner steel tube, an outer FRP tube, and concrete in between. The diameter and wall thickness of the inner steel tube in DSTCs served as the test parameters for this investigation. 21 cylindrical specimens with a diameter of 152 mm and a height of 305 mm were fabricated from high-strength concrete with a compressive strength of 55.9 MPa and subjected to monotonic axial compression. The findings from this experimental investigation demonstrate that as the diameter of the inner steel tube grows the load capacity of the DSTCs decreases, with this impact being dependent on the thickness of the outer FRP tube. In addition, the load capacity of the DSTCs increases as the thickness of the inner steel tube increase, independent of the thickness of the outer FRP tube.