Flexural behavior of concrete-filled double skin steel tubes with a joint

In the present study, concrete-filled double skin steel tubes (CFDSTs) with a joint, which are lighter and more economical than concrete-filled steel tubes (CFSTs), were developed. The CFDSTs are made of two steel tubes of different diameters with concrete filling the space between them. The length, the outer and inner diameters of a CFDST are 10 m, 914.4 mm, and 514.4 mm, respectively. Two types of shear connectors consisting of M16 and steel plate studs were used. A new type of connection in CFDSTs was developed to transfer the imposed load effectively. Four different specimens were made to test all possible combinations of the two different shear connectors (M16 studs, steel plate studs) and joints. The bending performance of the CFDSTs was investigated through 4-point loading experiments and finite element analysis (FEA). Finally, a comparison of design predictions and experiment results was made for these tubes. (C) 2018 Elsevier Ltd. All rights reserved.