Behaviour and design of concrete-filled mild-steel spiral welded tube short columns under eccentric axial compression loading

Effects of SWS Strength and Concrete Air Void Composite Defects on Performance of CFST Arch Bridge Rib

“…Figure 18 compares the N−ε curves of the CFST rib with different air void rates (α � 10%, 20%, and 30%) or without. It can be observed from Figure 18 that the CFST exhibited typical strain-softening characteristics when there were air voids or not, which is consistent with the results in Gunawardena and Aslani [2] and Gunawardena et al [3].…”

“…erefore, it can be concluded that the strength reduction of the SWS single defect had almost no effect on the CFST bearing capacity when the internal concrete had no defects. is is certificated by the observations of previous experiences in Gunawardena and Aslani [2] and Gunawardena et al [3].…”

“…For a CFST rib with air void defect, it appears that the air void rate is a decisive factor affecting the rib bearing capacity. ere has been no SWS-S defect research thus far, and the SWSs studied by Gunawardena and Aslani [2] and Gunawardena et al [3] were standard welds that met the design requirements and had no defects. However, the arch rib element SWSs of this bridge is defective.…”

“…For quantitative evaluation of the influence of the SWS-S and air void composite defects on the CFST bearing capacity, a strength index SI is defined by equation (2). e SI values are nearly equal to 1, when single defect of SWS-S decreased from 80% to 50%.…”

“…Meanwhile, owing to the limitations of technical levels over 20 years ago, the spiral-welded seam (SWS) only penetrated 70%. Many tests have been conducted on concrete-filled SWT columns, considering short and long column behavior, to estimate the applicability of existing guidelines for evaluating their strength and failure types [2,3]. erefore, for the accurate evaluation of the bearing capacity of the Chang-Qing Hun River Bridge, the impact of SWS should be studied in depth.…”