Axial Compression Performance of L-Shaped Partially Encased Steel–Concrete Composite Stub Columns

Abstract

The L-shaped partially encased steel–concrete composite (PEC) stub column, composed of profile steel, concrete, and transverse links, tends to occupy less space than the rectangle-shaped PEC column when used as side or corner columns. In this study, an axial compression test involving three L-shaped PEC stub columns was conducted to investigate the influence of critical factors on axial compression performance. The test results indicated that the axial compression capacity can be effectively enhanced with an increase in material strength. Furthermore, finite element (FE) analysis was carried out with parameters such as material strength, steel thickness, transverse link spacing, transverse link diameter, transverse link distribution, and longitudinal rebar diameter. The results revealed that the primary failure modes of L-shaped PEC columns were concrete spalling and local buckling of the flange. Additionally, it was found that the increase in steel strength, steel thickness, and transverse link diameter, as well as the decrease in transverse link spacing, significantly improved the axial compression capacity and concrete confinement effect. However, an increase in concrete strength diminished the concrete confinement effect. Additionally, the accuracy of the axial compression capacity calculation methods in the Eurocode 4 and T/CECS719-2010 specifications for L-shaped PEC stub columns was verified. Finally, a calculation method based on the superposition principle incorporating the concrete confinement effect was proposed, and validated by comparing with experimental and FE results. Overall, this study could provide a theoretical basis for the engineering application of L-shaped PEC columns.

Keywords

• L-shaped
• partially encased steel–concrete composite stub column
• axial compression capacity
• concrete confinement effect