Performance of Special‐Shaped Concrete‐Filled Square Steel Tube Column under Axial Compression

Abstract

The axial compressive performance of novel L-shaped and T-shaped concrete-filled square steel tube (L/T-CFSST) column was assessed in this study. Ten L/T-CFSST columns were tested to failure under axial load. The experimental data were used to determine various failure modes, bearing capacities, and load-displacement curves. The test parameters included the section form, steel tube thickness, steel yield strength, and slenderness ratio. The axial compressive performance of the L/T-CFSST column proved favorable, and each square steel tube showed strong cooperative performance. The failure mode of the stub column specimen (H/D ≤ 3) was strength failure caused by local buckling of the steel tube and that of the medium-long column member (H/D > 3) was instability failure caused by overall bending of the specimen. A finite element analysis (FEA) model was established and successfully validated by comparison against the test results. Based on the FEA model, parametric analyses were conducted to investigate the effects of steel tube thickness, concrete strength, steel yield strength, and slenderness ratio. The ultimate loads obtained from the experiments and FEA were compared to the results calculated by the available design codes. A formula was established to calculate the axial compressive strength and stability bearing capacity of the L/T-CFSST column accordingly. The calculation results are in close agreement with the FEA and experimental results, and the proposed formula may provide a workable reference for practicing engineers.

Study on Axial Compression Behavior of Cross-Shaped and L-Shaped Multi-cavity Concrete-Filled Steel Tube Special Shaped Column

“…On the other hand, the hoop coefficient, ξ, of the specimen decreases with the increase of the strength of concrete, which leads to the decrease of the restraint effect of multi-cavity steel tube on concrete. This further accelerates the decline rate of bearing capacity and reduces the ductility of the specimen (Wang, Zhou, et al, 2020).…”

Experimental Study of H‐Shaped Honeycombed Stub Columns with Rectangular Concrete‐Filled Steel Tube Flanges Subjected to Axial Load

“…Yang et al [28] researched the seismic behavior of four-legged square CFST latticed members under lateral cyclic loading and revealed that the fourlegged square CFST latticed specimens outperformed hollow steel ones in terms of hysteretic behavior. Wang et al [29] experimentally investigated the axial compressive performance of novel L-shaped and T-shaped concretefilled square steel tube (L/T-CFSST) columns and established formulae to calculate the axial compressive strength and stability bearing capacity of the L/T-CFSST columns accordingly. Shariati et al [30] presented a numerical investigation into the behavior of built-up concrete-filled steel tube columns under axial compression and indicated that the raise of concrete strength with greater cross section led to a higher load bearing capacity compared to the steel tube thickness increment.…”

A Study on Axial Compression Performance of Large Diameter‐Thickness Ratio Concrete‐Filled Gas Drainage Steel Pipe

“…e confinement effect of external steel pipe changes the concrete from two-way stress state to three-way stress state, which can improve the compressive properties of concrete. e internal concrete can improve the buckling of steel pipe and ensure the full play of material properties [9][10][11].…”

“…Concrete-filled steel pipe has been widely used in ground buildings due to its high strength and good ductility [9,[11][12][13][14][15][16]. In recent years, some scholars have begun to propose the introduction of concrete-filled steel pipe into coal mine roadway support.…”