Investigation on Seismic Behavior of Prestressed Steel Strand Composite Reinforced High-Strength Concrete Column

To study the seismic performance of high-strength concrete columns reinforced with prestressed steel strands, five column specimens were designed and tested with varying parameters, such as axial compression ratio (0.2, 0.35, 0.5) and diameter of steel strands (9.5 mm, 11.1 mm, 12.7 mm), under low-cyclic reversed loading. The failure modes, hysteretic curves, stiffness degradation, ductility, and energy dissipation capacity of the prestressed steel strand-reinforced concrete columns were observed and recorded. The test results show that the failure mode of the prestressed steel strand-reinforced concrete columns is obvious bending failure. Within a certain range of axial compression ratio, the initial stiffness and load-bearing capacity of the specimens increase with the increase in axial compression ratio, but the plastic deformation capacity decreases. Within a certain range of steel strand diameter, the initial stiffness and load-bearing capacity of the specimens also increase with the increase in steel strand diameter, but the ductility coefficient first increases and then decreases. In addition, the seismic performance of prestressed steel strand-reinforced concrete columns was analyzed by the finite element method using DIANA software, and the results were compared with the test results. It was found that the hysteretic curve and stiffness degradation curve obtained from the finite element model are in good agreement with the test results, and the finite element model can accurately study the seismic performance of this type of column. Finally, based on the finite element model, the influence of different parameters on the mechanical properties of the column was discussed.