Axial compressive behavior of circular concrete-filled double steel tubular short columns

Abstract

This article investigates the axial compressive performance of concrete-filled double steel tubular (CFDST) short columns composed of circular section loaded concentrically. An experimental program comprised of compression tests on short columns is carried out to examine their structural performance. Axial compression tests on conventional concrete-filled steel tubular (CFST) columns and double-skin concrete-filled steel tubular (DCFST) columns are also performed for comparison purposes. The test parameters include the diameter-to-thickness of the outer and inner steel tubes, concrete strength, and diameter ratio. The test results exhibit that CFDST short columns composed of the circular section have improved structural performance compared to its CFST and DCFST counterparts. A theoretical model is also presented to simulate the test ultimate strengths and load-axial strain relationships of CFDST columns. The existing design models proposed including the codified design specifications are evaluated against the collected test data for predicting the axial compressive strengths of circular CFDST columns. It is seen that the existing codified design models cannot yield their ultimate axial compressive strengths accurately. A practical artificial neural network (ANN) model is proposed to estimate the ultimate load of such columns loaded concentrically.

Axial behavior of precast segmental hollow bridge columns confined by grouted steel tubes

“…For the TPSBC under the loading form B, its axial compressive behavior is similar to that of the concrete-filled steel tubular columns (Ci et al, 2022;Han et al, 2008Han et al, , 2014Li et al, 2017;Zhao et al, 2019). Three types of confined concrete are considered due to the different strengths of the segment concrete and sandwich concrete, and different lateral confinements, as shown in Figure 12.…”

Behavior and design of axially loaded square concrete-filled double steel tubular slender columns

“…The steel tube confines the infilled concrete effectively and acts as formwork during the construction. The CFST columns offer better mechanical performance in terms of strength, ductility, seismic and fire performance compared to the traditional reinforced concrete columns (Ahmed and Liang, 2021; Ahmed et al, 2022; Ci et al, 2021a; Ci et al, 2021b). Existing studies showed that confinement was more uniform for the circular cross-section than the square or rectangular cross-sections of CFST columns; therefore, the strength and ductility of square or rectangular CFST columns are lower than their circular counterparts (Sakino et al, 2004).…”

Behavior and Design of Circular Concrete-Filled Double Steel Tubular Slender Columns under Axial Loading

“…1, where D0 and Di are the diameter of the outer and inner tube, respectively and t0 and ti are the thickness of the outer and inner steel tube, respectively. The inner tube provides additional confinement to the core concrete, thus the strength and ductility of a circular CFDST column are higher than those of a conventional circular CFST column [5][6][7]. Moreover, in a CFDST column, the sandwiched concrete between two tubes and the core concrete within the inner tube can be designed to have different strengths to maintain a good ductility.…”

“…Experiments on circular CFDST columns have been primarily focused on investigating the performance of short columns, where the length-to-diameter ratio (L/D0) was limited to 4 to prevent the global buckling from occurring [5,6,8,9]. A circular CFDST slender column with an L/D0 ratio greater than 4 may fail due to global buckling, which reduces the ultimate strength of the column significantly.…”