Behavior and strength of tubed RC stub columns under axial compression

2015

Thin-Walled Structures

Abstract:The post-fire behaviour of slender reinforced concrete columns confined by circular steel tubes is investigated experimentally and numerically in this paper. Experiments were performed firstly to explore the fundamental behaviour of steel tube confined reinforced concrete (STCRC) slender columns after exposure to the ISO-834 standard fire, including the cooling phase. Temperature distributions, load versus lateral displacement curves, strains in the steel tube and failure modes were obtained and discussed. Next, a 3D finite element model was developed with the program ABAQUS using a sequentially coupled thermal-stress analysis. After validation of the FE model, parametric studies were carried out to identify the influence of key parameters on the load-bearing capacity and buckling reduction factor of slender STCRC columns. The considered parameters were the heating time, cross-sectional dimension, slenderness ratio, material strength, steel tube to concrete area ratio and reinforcement ratio. Finally, a simplified design method was proposed for predicting load-bearing capacity of STCRC slender columns after exposure to standard fires. Yang, H., Liu, F., and Gardner, L. (2015). Post-fire behaviour of slender reinforced concrete columns confined by circular steel tubes.

“…Zhou [11]. The results of the parametric study, showing the influences of the key variables on the buckling reduction factor, are presented in Fig.16.…”

Section: Design Methodsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Post-fire behaviour of slender reinforced concrete columns confined by circular steel tubes

2015

Thin-Walled Structures

“…Liu and Zhou [9] proposed a method for predicting the load bearing capacity of CSTCRC columns that have not been exposed to fire, given as follows:…”

Section: Parametric Studies and Design Methodsmentioning

confidence: 99%

“…Experimental studies were conducted to investigate the axial compressive performance [8] and seismic performance [6,7] of this kind of member, yielding very promising results. Liu and Zhou [9,10] conducted experiments on the axial compressive behaviour and seismic behaviour of circular and square shaped STCRC columns and proposed design methods for predicting the axial load bearing capacity and shear capacity of these columns. Han et al [11] conducted experiments on the seismic performance of reinforced concrete beam to STCRC column connections, confirming their good seismic performance and applicability in practical building structures.…”

Section: Introductionmentioning

confidence: 99%

Post-fire behaviour of reinforced concrete stub columns confined by circular steel tubes

Journal of Constructional Steel Research

2014

Abstract:Experimental and numerical studies into the structural behaviour of reinforced concrete columns confined by circular steel tubes after exposure to standard fire conditions are presented. These elements differ from conventional concrete-filled steel tubular (CFST) columns in that breaks in continuity are present at the member ends, which limit the longitudinal stresses in the steel and maximise the level of confinement afforded to the concrete through the generation of hoop stresses in the tube. The temperature distributions in the specimens were measured during the heating and cooling phases, while the load-displacement relationships and longitudinal and transverse strains in the steel tube were recorded during the subsequent compressive tests. 3D finite element (FE) models were also developed using the program ABAQUS to investigate the post-fire performance of circular steel tube confined reinforced concrete (CSTCRC) columns, including both heat transfer and stress analyses. The FE models were used to identify the influences of key parameters on the residual capacity of CSTCRC columns, following exposure to the ISO-834 standard fire. The considered parameters included heating time, cross-sectional dimensions, strength of the materials, steel tube to concrete area ratio and ratio of reinforcement. Finally, a design method was proposed for predicting the residual load bearing capacity and compressive stiffness of CSTCRC columns after standard fire exposure.

“…Previous studies, conducted by Tommi et al [3][4][5], Sun et al [6], Aboutaha et al [7,8], Han et al [9,10], Liu et al [11][12][13] and Yu et al [14], have all focused on the compression behaviour or seismic performance of steel tube confined reinforced (or plain) concrete columns at ambient temperature.…”

mentioning

confidence: 99%

Post-fire behaviour of eccentrically loaded reinforced concrete columns confined by circular steel tubes

Journal of Constructional Steel Research

2016

Abstract:The post-fire behaviour of eccentrically loaded reinforced concrete columns confined by circular steel tubes, also known as circular steel tube confined reinforced concrete (STCRC) columns, is investigated in this paper. A total of 12 experiments were conducted on eccentrically loaded circular STCRC stub columns after exposure to the ISO 834 standard fire, including both the heating and cooling phases. The temperatures across the tested sections, the axial load versus lateral displacement responses and the strains in the steel tubes were all measured and discussed. A finite element (FE) model was developed using the program ABAQUS, and validated against the test results from the present study, as well as related studies. Parametric studies were then performed to identify the influences of key parameters on the residual capacity of the eccentrically loaded STCRC columns, including eccentricity ratio, heating time, cross-sectional diameter, slenderness ratio, material strengths, steel tube to concrete area ratio and reinforcement ratio. Finally, a simplified method was proposed for predicting the residual load-bearing capacity of the eccentrically loaded STCRC columns after fire exposure.