Ultra-high Strength Concrete on Eccentrically Loaded Slender Circular Concrete-filled Dual Steel Columns

Abstract

This paper presents an experimental study which was undertaken to investigate the effect of ultra-high strength concrete (UHSC) on the mechanical response of concrete-filled dual steel tubular columns (CFDST) subjected to eccentric loads. This campaign is a continuation of a previous program on axially loaded members and consists in testing 12 CFDST specimens and two concrete-filled tubular (CFST) columns which serve as references. The location of the dual-grade concretes (outer ring and inner core) and the steel thicknesses configuration were the parameters analysed. Therefore, in this program, two series can be distinguished: 6 columns with normal strength concrete in their outer rings and, conversely, 6 with ultra-high strength concrete. In addition, two different steel tube thicknesses configurations were considered: columns with thin outer steel tube and thick steel tube (thin-thick); and the opposite pattern (thick-thin). Moreover, the experiments on the CFST columns of reference served to investigate the effect of the extra inner steel tube and its filling in CFDST columns. Since the number of campaigns on eccentrically loaded slender CFDST columns is scarce, the results presented in this work become particularly relevant.The analysis of the results revealed that, for both series, the response of the specimens showed similar trend but the effect of UHSC differed from that observed for axially loaded Ibañez C, Romero ML, Espinos A, Portolés JM, Albero V. Ultra-high strength concrete on eccentrically loaded slender circular concrete-filled dual steel columns. 2017. Structures; 12: 64-74. doi: 10.1016/j.istruc.2017 2 columns. Finally, the experimental data were contrasted to the predictions given by Eurocode 4 for the design of composite columns resulting, in general, in slightly unsafe predictions.

Experimental and numerical studies of square concrete-filled double steel tubular short columns under eccentric loading

“…Little research has been reported on the structural behavior of thin-walled CFDST square columns that are subjected to eccentric loads. This paper Most of the investigations on CFDST columns reported previously has focused on circular cross-section [1][2][3][4][5][6][7][8][9][10][11][12] and tests on short square CFDST columns consisting of an inner circular steel tube have been very limited [13][14][15][16]. Pei [13] performed tests to determine the structural performance of stub CFDST square columns under axial and eccentric loads.…”

Numerical analysis of axially loaded circular high strength concrete-filled double steel tubular short columns

“…In comparisons with experimental studies on CFST columns, only limited experimental investigations on CFDST columns with circular sections were performed by researchers, such as Xiong et al [6], Peng et al [8], Liew and Xiong [9], Romero et al [10], Wan and Zha [11], Ekmekyapar and Al-Eliwi [12]and Ibañez et al [13]. Peng et al [8] Experimental observations indicated that the column ultimate strengths were reduced by increasing the / o o D t ratios of the outer tube.…”

Numerical simulation of high strength circular double-skin concrete-filled steel tubular slender columns

“…However, only very limited experiments on circular DCFST slender columns have been conducted, such as those by Tao et al [1], Essopjee and Dundu [2] and Ibañez et al [3], and no numerical studies on high-strength DCFST slender columns made of carbon steel tubes have been undertaken. Moreover, there is a lack of understanding of the load distributions and concrete confinement characteristics in circular DCFST slender columns.…”

“…Limited experiments on circular DCFST slender columns subjected to eccentric loading or axial compression were performed in the past [1][2][3]. Tao Computational models that calculated the nonlinear responses of CFST circular columns were developed by Hajjar et al [16], Susantha et al [17], Shanmugam et al 18], Hu et al [19],…”