Seismic behavior of prefabricated high-strength concrete columns confined by overlapping stirrups

Abstract

Six specimens of prefabricated high-strength concrete columns with confining overlapping stirrups were tested under cyclic lateral loads, and a finite element analysis was performed using ABAQUS to investigate the seismic behavior of the columns. The influences of the axial compression ratio, stirrup diameter and stirrup spacing were considered. Comparative analyses indicate that the numerical simulation outcomes agree well with the experimental results, including the hysteretic curves, peak loads and failure modes. With an increase in the axial compression ratio, the ultimate load bearing capacity of the specimen increases, ductility worsens, strength descending part of the shear-displacement skeleton curves steepens, and energy dissipation capacity increases slightly. When the stirrup spacing decreases or the stirrup diameter increases, the ultimate load bearing capacity, ductility and energy dissipation capacity of the specimens increase. The effect of the axial compression ratio on the shear capacity of the test specimens is much more pronounced than that of the stirrup ratio. With an increase in the stirrup diameter, the initial stiffness of the specimen decreases, and stiffness deterioration during the late stages of loading cycles slows down. However, changing the spacing of the stirrups has little effect on the stiffness of the specimens.