Numerical simulation of axially loaded square high-strength concrete short columns with steel equal-angles as longitudinal reinforcement

Steel Equal-Angle (SEA) can be used to replace the longitudinal reinforcement in concrete columns to improve their strength and ductility. However, as a novel concept of applying SEA as longitudinal reinforcement in concrete columns, experimental and numerical studies are very limited on the behavior of SEA Reinforced Concrete (SEARC) columns constructed with high-strength concrete. This paper presents a numerical simulation model based on the fiber-element method for computing the axial performance of square SEARC short columns loaded axially. The model accounts for the inelastic buckling of SEA sections and confinement effects provided by SEA to the confined concrete. Available test data is used to examine the accuracy of the numerical model. It is shown that there is a good agreement between numerical simulation and experimental data. The numerical model is employed to investigate the influences of important parameters on the responses of short SEARC col-umns subjected to axial compression. It is demonstrated that the strength and ductility of SEARC columns are significantly affected by the width of SEA sections, compressive strength of concrete, and the spacing of the lateral ties. Finally, the applicability of the design codes, including Eurocode 2, ACI 318-19, and AS 3600 for conventional reinforced concrete columns, to the design of SEARC columns is examined. The results show that the design formulae specified by AS 3600 can be used to calculate the ultimate strength of SEARC columns with reasonable accuracy.