EXPERIMENTAL STUDY OF AXIAL COMPRESSION PROPERTIES OF CONCRETE-FILLED STEEL TUBES WRAPPED WITH BFRP

Wrapping BFRP sheets on the steel tube can effectively increase the axial capacity and improve the ductility and durability of concrete-filled steel tubes ( CFST) ． This paper presented an experimental study on the axial compressive capacity of the CFST wrapped with BFRP sheets． Four CFST specimens wrapped with BFRP sheet and 3 plain CFST specimens were tested under axial loading，which were analysed by the load - displacement curves and load -strain curves． The experimental results show that 4 strengthened specimens were failed by BFRP rupturing after steel tube buckling． The axial capacity of the CFST was improved by 17. 3% through wrapping BFRP and the ductility of the CFST was improved as well． The good agreement between the experimental axial capacity and the analytical results confirms the validity of the theoretical analysis．