Abstract：In order to investigate the seismic performances of composite columns with steel
reinforced concrete(SRC) square section and reinforced concrete(RC) circular section in
traditional style buildings, two specimens of composite columns with variable section in full
scale were tested under low-cyclic reversed loading. The failure modes, hysteretic performance,
degradations of rigidity and strength, ductility and dissipation capacity of the specimens were
obtained. It is shown that the failure of composite columns with SRC square section and RC
circular section is mainly caused by yielding of steel and reinforcement and concrete spalling
of upper column at the variable section. The hysteretic loops of the columns are in plump-
shape. As the columns failed, the ductility factor of the story drift is between 3.18 and 3.76,
and the equivalent viscous damping coefficient is about 0.289 to 0.338, showing excellent
capacities of deformation and energy dissipation. Based on the experimental research, the
finite element program ABAQUS was used to establish 3D model. The concrete strength, axial
compression ratio, yield strength of steel and stiffness ratio of upper to lower column were
considered as analysis parameters. The experiment and numerical simulation results show that
the horizontal bearing capacity increases with the increment of concrete strength and yield
strength of steel, but the ductility of the columns decreases. The horizontal bearing capacity
and ductility of the columns decrease as axial compression ratio increases. However, the
horizontal bearing capacity and ductility of the columns may be improved with the increment of
stiffness ratio of upper to lower column.
