Theoretical Model for Double-Skinned Concrete-Filledsteel-Tubular Columns With External Confinement

Abstract

Recent advances in the production of super-fine cement and filler technology has made the production of high-strength concrete (HSC) of 120 MPa practicable in the industry. Nonetheless, the application of such HSC in real construction is still limited. One of the reasons that inhibits the use of HSC is the brittleness, which causes HSC structures to fail explosively if the concrete confinement is not adequate. The traditional method of installing transverse steel as confinement is not feasible in HSC structures, as the steel will be too congested to ensure proper concrete placing. To overcome the problem, double-skinned high-strength concrete-filled-steel-tubular (HSCFST) columns has been advocated, which could provide large, continuous and uniform confinement to HSC. However, a major shortcoming of the double-skinned HSCFST columns is the imperfect interface bonding that occurs at the elastic stage that reduces the elastic strength and stiffness of columns. To improve the situation, the authors have verified previously that using external steel rings on the outer steel tube can successfully restrict the dilation of HSCFST columns and thus restore an intact interface bonding condition. As a continued study, the authors will in this paper develop a theoretical model for predicting the uni-axial load-carrying capacity of doubled-skinned HSCFST columns.

Axial compression behaviour of concrete filled double skin steel tube columns anchored with orbicular rings: Experimental and numerical approach

“…The empirical formulas to check the ultimate capacity were suggested. This suggested relation can predict the strength of CFDST and can be useful for structural designers (Dong and Ho, 2015;Ho and Dong, 2014). Further, various studies were conducted on stiffened CFDST columns' behavior under axial concentric and eccentric compressive forces.…”

Influence of anchored orbicular rings on the performance of sandwich concrete‐filled double‐skin steel tube columns

“…The proposed equation was, , to estimate the strength of CFDST column subjected to uniaxial loading and is useful for structural designers. Furthermore, Ding and Ho proposed another theoretical model for capacity of double‐skin specimen with external ring confinement as 27 For hollow ratio ranging from 0.56 to 0.72, suggested model accurately predicts the strength of ring confined double‐skinned specimen.…”

Experimental study and calculation of confinement relationships for prestressed steel tube-confined compressed concrete stub columns

“…Hence, the STCC columns provide greater strength and ductility as well as the lower chance of steel tube buckling compared to the CFST columns (Yu et al 2010). STCC columns were first investigated by Tomii et al (1985Tomii et al ( , 1987, and since then, several research results on the STCC columns have been reported by different researchers in the literature (Han et al 2005(Han et al , 2009Zhang et al 2013;Xiao 2005;Dong, Ho 2015;Lee et al 2014).…”