Axial compression performance of concrete filled double skin (SHS outer and SHS inner) steel tubular columns confined by CFRP

Abstract

This paper focuses on the axial compression performance of 15 concrete filled double skin tubes CFDST columns by the different CFRP reinforcement schemes. The design of this test used an outer square steel tube with a square steel tube inside and concrete poured at the sandwich and the inner steel tube kept in hollow. Firstly, the damage mechanisms of the specimens were observed and analysed. Secondly, the mechanical properties of the specimens were further analysed from the data of load displacement, peak load and ultimate displacement. The data analysis was mainly used to compare the different axial compressive properties of CFDST columns wrapped with CFRP sheet and those without CFRP sheet. Finally, by referring to the previous model on CFRP-CFST, a modification was made and a computational model of a CFRP-confined CFDST column was developed, which was found to be in good agreement with the experimental results by comparison.