Axial Compression Test and Numerical Study of Duplex Stainless Steel Reinforced Concrete Short Columns

In order to explore the mechanical properties of duplex stainless steel reinforced concrete columns, five duplex stainless steel reinforced concrete columns were designed for axial compression testing. The failure phenomenon, concrete strength and longitudinal reinforcement ratio were analyzed. The ABAQUS finite element model considering material nonlinearity was established, and the parametric expansion analysis was carried out. The results show that when the strength grade of C30 concrete increases to C80, the bearing capacity of the test column increased by 46%, but the growth rate of its peak bearing capacity decreased to 6.9%. The peak bearing capacity and peak displacement of the test column increase with the longitudinal reinforcement ratio. When the reinforcement ratio is between 0.5% and 6%, the peak bearing capacity growth rate is between 8.9% and 36.9%, and the peak displacement growth rate is between 6.2% and 28.9%. Considering comprehensively, it is recommended that the longitudinal reinforcement ratio of the duplex stainless steel reinforced concrete column should be between 1% and 4%. Based on the experimental and simulation results, a formula for calculating the axial compression bearing capacity of duplex stainless steel reinforced concrete columns is proposed. The recommended value of longitudinal reinforcement ratio and the calculation formula of axial compression bearing capacity are obtained, which can provide reference for the design and bearing capacity prediction of duplex stainless steel reinforced concrete short columns under axial compression.