Shear behavior of thin-walled concrete-filled steel tubular columns.

Shear failure is a brittle type of failures, which should be avoided in any structure as it could cause property loss and human casualties. The shear behavior of thin-walled concrete-filled steel tubular (CFST) columns was hence investigated in this study, involving the tests of 24 thin-walled CFST columns and considering the following parameters: shear span-to-depth ratios = 0.15, 0.3, 0.5, 1, 1.5, and 2; confinement factor = 0.63, 1.27, 1.44, and 1.70; and axial load ratios = 0, 0.2, 0.4, and 0.6. The test results revealed the insights of the initial shear stiffness, failure modes, ultimate bearing capacity, load-deflection curves, load-strain curves, and ductility of the specimens. Based on the failure modes, a method is proposed to evaluate the load resistance, and explain the relationship between the shear span-to-depth ratio and the peak bearing capacity. A compression strut mechanism considering the confinement provided by the steel tube flange is also proposed. The effect of axial load on the shear strength of the concrete core is negligible when the axial load ratio doesn't exceed 0.4. The predicted results from using the proposed simple model agree generally well with the experimental results. • Monotonic tests are conducted to obtain the shear behavior of the thin-walled CFST columns designed with major parameters. • Steel tubes and concrete's contributions to shear capacity are clarified by experimental and analytical results. • The exact effects of some parameters on failure modes and shear capacity are explained based on the experimental data. • The formulas on the shear capacity of the thin-walled CFST columns are proposed based on the compression strut mechanism. [ABSTRACT FROM AUTHOR]