Compressive behavior of concrete-filled GFRP tubular stub columns after being subjected to freeze-thaw cycles

Abstract

This paper aims to investigate the mechanical properties of concrete-filled glass fiber reinforced plastic (GFRP) tubular stub columns after being subjected to freeze-thaw cycles (FTCs). A total of 72 concrete-filled GFRP tubular (CFGT) stub columns treated with different FTCs were tested under axial load. The ultimate capacity, initial stiffness, load-displacement curves, load-strain curves, and failure modes were obtained and analyzed. Test results indicated that the failure phenomena of the specimens under axial compression were similar, mainly including the fracturing of GFRP tube and crushing of core concrete. The FTCs, concrete strength and column height all had a significant influence on the failure modes of the specimens. The ultimate capacity and initial stiffness decreased evidently with the increase of the number of FTCs. By increasing the height of the column, the ultimate capacity and deformation capacity of square column after FTCs could be effectively improved. The change of ultimate capacity of the CFGT column after FTCs was the result of the combined effect of FTCs, concrete compressive strength and column height. Finally, the simplified formulas for calculating the ultimate capacity of CFGT stub columns after FTCs were proposed.