This paper aims at investigating the general axial behavior of long circular concrete-filled,\nfiber-reinforced polymer (FRP) tube (CFFT) columns internally reinforced with different longitudinal\nrebars. A total of seven CFFT and three reinforced concrete (RC) columns served as control specimens\nfor comparisons and were constructed and tested under cyclic axial loading until failure. The test\nparameters were: (1) internal reinforcement type (steel, glass fiber-reinforced polymer (GFRP) or\ncarbon fiber-reinforced polymer (CFRP)) and amount; (2) GFRP tube thicknesses; and (3) nature of\nloading. All columns had 1900-mm in height and 213-mm in diameter. Examination of the test results\nhas led to a number of significant conclusions in regards to the trend and ultimate condition of the\naxial stress-strain behavior, mode of failure of tested CFFT columns, and plastic strains. As expected,\nan increase in the FRP tube thickness (or stiffness) resulted in an increase in the strength and strain\nenhancement ratios. The validity of the available design provisions for predicting the ultimate\nload-carrying capacity of tested columns is also highlighted.
Loading....