Column tests of dodecagonal section double skin concrete-filled steel tubes

• A series of column tests of dodecagonal section double skin concrete-filled steel tubes were presented in this study.
• The load–displacement curves, load–strain curves, failure modes and ultimate capacity of test specimens were obtained.
• The local buckling of dodecagonal section double skin concrete-filled steel tubes under axial compression was investigated.
• Comparison of behavior between dodecagonal section and circular section specimens were made.
• The suitability of current design methods were evaluated.

A series of tests on dodecagonal section double skin concrete-filled steel columns (DCS) were carried out in this study. Column specimens having different lengths ranged from 1000 mm to 3500 mm were tested. The behavior and strengths of dodecagonal section double skin concrete-filled steel columns were investigated. In addition, local bucking of inner and outer steel tubes were also investigated. Material properties of the concrete and steel used in the test specimens were measured. The test strengths are compared with the design strengths calculated using the proposed methods based on current AISC Specification and Eurocode for the design of composite structural members. The suitability of design method proposed by other researcher for circular section double skin concrete-filled steel columns for dodecagonal section specimens was also evaluated.