Modified confinement model for monotonic axial behavior of concrete-filled tubular columns

Concrete-filled tubular (CFT) columns exhibit higher axial resistance and better displacement ductility as compared to the conventional reinforced concrete members. The performance of CFT members may be influenced by many geometric material parameters. This study presents an experimental on twenty-two column specimens subjected monotonic compressive loading until their failure. main parameters varied in test were grade concrete, slenderness i.e., length-to-depth (L/D) ratios, tube compactness depth-to-thickness (D/t) ratios. L/D ratios range 3–10 for two different values D/t (i.e., 13 26). was evaluated terms peak strength, ductility, post-peak resistance. Test results showed that increased, improved. Further, increase resulted a steeper degradation stiffness columns. An analytical investigation also conducted predict strengths using available confinement models various design codes. 10–120, whereas ratio between 3 48 study. Based both investigations, modified model has been proposed strength well includes effects grades, ratio, ratio.