Research on Mechanical Properties of Circular Tubed Steel-Reinforced Concrete Stub Columns with High-Strength Steel Under Axial Compression

Incorporating high-strength steel in circular tubed steel-reinforced concrete (STRC) stub columns offers several advantages, including avoiding local buckling in thin-walled steel and enhancing the mechanical properties of the columns. This paper employed the ABAQUS software to develop a finite element analysis model for circular steel tube-reinforced concrete stub columns under axial compression. Systematic parameter analysis was conducted to examine the effects of factors such as the shape and strength of the steel section, the strength of the steel tube and concrete, and the steel ratio. The load contribution values and section stresses of each component in the STRC columns were analyzed to further reveal the mechanism of the columns under axial compression. The results revealed that the bearing capacity of STRC columns under axial compression increased with the strength of the steel tube, steel profile, and concrete. The steel tube provided axial-bearing capacity through friction with the concrete, although this capacity was independent of the strength of the steel tube or the concrete. Additionally, the axial bearing capacity was affected by the steel tube indirectly through the confining effect on the concrete. The shape change of the steel profile would alter the confining area of the concrete, which in turn influenced the mechanical properties of the component under axial compression.Enhancing the strength of the steel profile would improve its load contribution, thereby affecting the bearing capacity of the component. With the same steel content, an increase in the strength of the steel tube had a greater effect on augmenting the axial bearing capacity than the same increase in the strength of the steel profile.