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Linhai Han - One of the best experts on this subject based on the ideXlab platform.

  • behaviour of concrete encased cfst Columns under combined compression and bending
    Journal of Constructional Steel Research, 2014
    Co-Authors: Linhai Han
    Abstract:

    Abstract The performance of concrete-encased CFST Column under combined compression and bending is studied in this paper. A finite element analysis (FEA) model is developed to analyse the behaviour of the Composite Column, and generally good agreement is achieved between the measured and predicted results in terms of the failure mode, the load-deformation relation and the ultimate load. Typical failure modes, full-range response of load-lateral deflection relation, loading distributions of the inner CFST and the outer RC components, the contact stress between the steel tube and the concrete of the Composite Columns are analysed. The influence of slenderness ratio and loading paths on the Composite Columns are also investigated. Influence of parameters, such as the strength of concrete and steel, steel ratio of CFST, longitudinal bar ratio and diameter of CFST on the sectional capacity of the concrete-encased CSFT Columns is analysed based on the FEA model. A simplified model is proposed to calculate the sectional capacity of concrete-encased CFST Columns under combined compression and bending.

  • tests on cyclic behavior of concrete filled hollow structural steel Columns after exposure to the iso 834 standard fire
    Journal of Structural Engineering-asce, 2004
    Co-Authors: Linhai Han, Xiaokang Lin
    Abstract:

    The strength and seismic behavior of a Composite Column may be used to assess the potential damage caused by fire and help to establish an approach to calculate the structural fire protection for minimum postfire repair. This paper provides new test data pertaining to the seismic behavior of concrete-filled hollow structural steel (HSS) Columns after exposure to fire. The test parameters included the sectional types, the fire duration time and the axial load level (\In\N). Thirteen concrete-filled HSS Column specimens, including seven specimens with circular sections and six specimens with square sections were tested under constant axial load and cyclically increasing flexural loading. Comparisons are made with predicted Column strengths and flexural stiffness using the existing codes. It was found that concrete-filled HSS Columns after exposure to fire exhibit very high levels of energy dissipation and ductility. Generally, the energy dissipation ability of the Columns with circular sections was much higher than those of the specimens with square sections. The work in this paper provides a basis for further theoretical study on the seismic behavior of concrete-filled HSS Columns after exposure to fire.

  • concrete filled hollow structural steel Columns after exposure to iso 834 fire standard
    Journal of Structural Engineering-asce, 2003
    Co-Authors: Linhai Han, Jingsi Huo
    Abstract:

    The use of hollow structural steel (HSS) Columns filled with concrete has become widespread in the past few decades. The residual strength of a Composite Column may be used to assess the potential damage caused by fire and help to establish an approach to calculate the structural fire protection for minimum postfire repair. The behavior of 12 concrete-filled HSS Columns with or without fire protection after exposure to the ISO-834 fire standard subjected to axial or eccentric loads has been experimentally investigated and the results presented in this paper. Comparisons are made with predicted Column strengths using the existing codes such as LRFD-AISC-1994, AIJ-1997, EC4-1996, DL5085/T-1999, and GJB4142-2000. A mechanics model is developed in this paper for concrete-filled HSS Columns after exposure to the ISO-834 fire standard, and is a development of the analysis used for ambient condition. The predicted load versus mid-span deflection relationship for the Composite Columns is in good agreement with test results. Based on the theoretical model, influence of the changing strength of the materials, fire duration time, sectional dimensions, steel ratio, load eccentricity ratio and slenderness ratio on the residual strength index (RSI) is discussed. It was found that, in general, the slenderness ratio, sectional dimensions and the fire duration time have a significant influence on the RSI. However, the steel ratio, the load eccentricity ratio and the strength of the materials have a moderate influence on RSI. Finally, formulas suitable for incorporation into building code, for the calculation of the residual strength of the concrete-filled HSS Columns after exposure to ISO-834 fire standard are developed based on the parametric analysis results.

Fubo Cao - One of the best experts on this subject based on the ideXlab platform.

  • Strength of slender steel reinforced concrete Composite Columns
    Fourth International Conference on Advances in Steel Structures, 2005
    Co-Authors: Gen-tian Zhao, Gang Xue, Zhuo Han, Fubo Cao
    Abstract:

    Publisher Summary The chapter presents the experimental study and results of a nonlinear numerical analysis on the behavior of slender steel reinforced high-strength concrete Composite Columns. Eight full-scale slender Columns with rectangular section are tested under axial and eccentric loading conditions. Effects of various geometric and material parameters, such as concrete strength, slenderness of Columns, and eccentricity of the applied axial load are studied in the chapter. Significant gains in load capacity are obtained with increased concrete strength for the Column subjected to axial load, but the capacity is not strongly influenced by the strength of concrete for the Column subjected to eccentric load. The capacity is reduced with increased slenderness ratio and eccentricity. The chapter presents a numerical method for the analysis of pin-ended slender Columns. This method, considering material and geometric nonlinearities, is applicable for determining the material failure load or the buckling failure load of a slender steel reinforced concrete Composite Column. The predicted failure loads are closer to the experimental values.

Gen-tian Zhao - One of the best experts on this subject based on the ideXlab platform.

  • Strength and Behaviour of Slender Steel Reinforced Concrete Composite Columns
    Advances in Structural Engineering, 2010
    Co-Authors: Gen-tian Zhao, Meng-xi Zhang
    Abstract:

    An experimental study of the behaviour of steel reinforced concrete (SRC) Composite Columns and the results of a nonlinear numerical analysis are presented. Ten slender SRC Composite Columns were tested under axial and eccentric loading conditions. The effects of concrete strength, slenderness of Columns and eccentricity of the axial load were studied. The load-carrying capacity is reduced with increased slenderness ratio and eccentricity. Concrete strength has a significant effect on the load-carrying capacity of axially loaded Columns but has no obvious influence in the case of eccentrically loaded Columns. This paper also presents a nonlinear numerical study of pin-ended slender Columns. The method is suitable for determining the material failure load or buckling failure load of a slender steel reinforced concrete Composite Column. In the method both material and geometric nonlinearities are taken into account. The numerical analysis results correlate well with the test results. The test results are al...

  • Strength of slender steel reinforced concrete Composite Columns
    Fourth International Conference on Advances in Steel Structures, 2005
    Co-Authors: Gen-tian Zhao, Gang Xue, Zhuo Han, Fubo Cao
    Abstract:

    Publisher Summary The chapter presents the experimental study and results of a nonlinear numerical analysis on the behavior of slender steel reinforced high-strength concrete Composite Columns. Eight full-scale slender Columns with rectangular section are tested under axial and eccentric loading conditions. Effects of various geometric and material parameters, such as concrete strength, slenderness of Columns, and eccentricity of the applied axial load are studied in the chapter. Significant gains in load capacity are obtained with increased concrete strength for the Column subjected to axial load, but the capacity is not strongly influenced by the strength of concrete for the Column subjected to eccentric load. The capacity is reduced with increased slenderness ratio and eccentricity. The chapter presents a numerical method for the analysis of pin-ended slender Columns. This method, considering material and geometric nonlinearities, is applicable for determining the material failure load or the buckling failure load of a slender steel reinforced concrete Composite Column. The predicted failure loads are closer to the experimental values.

Xiaokang Lin - One of the best experts on this subject based on the ideXlab platform.

  • tests on cyclic behavior of concrete filled hollow structural steel Columns after exposure to the iso 834 standard fire
    Journal of Structural Engineering-asce, 2004
    Co-Authors: Linhai Han, Xiaokang Lin
    Abstract:

    The strength and seismic behavior of a Composite Column may be used to assess the potential damage caused by fire and help to establish an approach to calculate the structural fire protection for minimum postfire repair. This paper provides new test data pertaining to the seismic behavior of concrete-filled hollow structural steel (HSS) Columns after exposure to fire. The test parameters included the sectional types, the fire duration time and the axial load level (\In\N). Thirteen concrete-filled HSS Column specimens, including seven specimens with circular sections and six specimens with square sections were tested under constant axial load and cyclically increasing flexural loading. Comparisons are made with predicted Column strengths and flexural stiffness using the existing codes. It was found that concrete-filled HSS Columns after exposure to fire exhibit very high levels of energy dissipation and ductility. Generally, the energy dissipation ability of the Columns with circular sections was much higher than those of the specimens with square sections. The work in this paper provides a basis for further theoretical study on the seismic behavior of concrete-filled HSS Columns after exposure to fire.

Kian Karimi - One of the best experts on this subject based on the ideXlab platform.

  • analytical modeling and axial load design of a novel frp encased steel concrete Composite Column for various slenderness ratios
    Engineering Structures, 2013
    Co-Authors: Kian Karimi, Michael Tait, Wael W Eldakhakhni
    Abstract:

    Abstract A novel Composite Column composed of steel, concrete and a fiber reinforced polymer (FRP) tube is presented in this paper. The confinement and Composite action between the constituent materials result in enhanced compressive strength, ductility and energy dissipation capacity of the proposed Composite Column compared to a traditional reinforced concrete (RC) Column. Due to the presence of the FRP tube, current design methods for concrete-filled steel tubes (CFSTs) or concrete-encased steel (CES) Columns are not directly applicable. An analytical model was developed to predict the behavior of the Composite Column for various slenderness ratio values. Predicted values are found to be in good agreement with the experimental results from tests of six Columns ranging from 500 mm to 3000 mm in height. A parametric study is conducted to investigate the influence of Column diameter, FRP tube thickness, axial compressive modulus of the FRP tube and steel-to-concrete area ratio on the capacity relationships and slenderness limits. Finally, a simplified design equation is proposed to predict the compressive load capacity of this type of Composite Column.

  • Influence of Slenderness on the Behavior of a FRP-Encased Steel-Concrete Composite Column
    Journal of Composites for Construction, 2012
    Co-Authors: Kian Karimi, Michael Tait, Wael W. El-dakhakhni
    Abstract:

    AbstractThe compressive behavior of a steel-concrete Composite Column encased in a fiber reinforced polymer (FRP) tube is evaluated experimentally for Columns with various slenderness ratios. The Composite Column consists of a FRP tube surrounding a steel I-section that is subsequently filled with concrete. A total of nine Column specimens were tested ranging between 500 and 3,000 mm in height. Confinement and Composite action resulted in enhanced compressive behavior of the Composite Columns. Maximum confinement occurred in the short Column (slenderness ratio less than 0.2). Confinement action reduced with increased height of the Column specimens. The Column load- carrying capacity, ultimate axial strain, and compressive strength of the confined concrete core in the longest specimen (slenderness ratio of 0.9) were reduced to approximately 59, 14, and 51% of the short Column values, respectively. A buckling strength curve of the Composite Columns was developed on the basis of the experimental results.

  • testing and modeling of a novel frp encased steel concrete Composite Column
    Composite Structures, 2011
    Co-Authors: Kian Karimi, Michael Tait, Wael W Eldakhakhni
    Abstract:

    Abstract A Composite Column consisting of steel, concrete and fiber reinforced polymer (FRP) is presented and assessed through experimental testing and analytical modeling. The Composite Column utilizes a glass FRP (GFRP) Composite tube that surrounds a steel I-section, which is subsequently filled with concrete. The GFRP tube acts as a stay-in-place form in addition to providing confinement to the concrete. This study investigates the behavior of the proposed Composite Columns under axial loading. A total of seven specimens were tested. The influence of concrete shrinkage on the compressive behavior of the Composite Columns was also investigated. Significant confinement and Composite action resulted in enhanced compressive behavior. The addition of a shrinkage reducing agent was found to further improve the compressive behavior of the Composite Columns. An analytical model was developed to predict the behavior of the Composite Columns under axial loading.

  • Testing and modeling of a novel FRP-encased steel–concrete Composite Column
    Composite Structures, 2011
    Co-Authors: Kian Karimi, Michael Tait, Wael W. El-dakhakhni
    Abstract:

    Abstract A Composite Column consisting of steel, concrete and fiber reinforced polymer (FRP) is presented and assessed through experimental testing and analytical modeling. The Composite Column utilizes a glass FRP (GFRP) Composite tube that surrounds a steel I-section, which is subsequently filled with concrete. The GFRP tube acts as a stay-in-place form in addition to providing confinement to the concrete. This study investigates the behavior of the proposed Composite Columns under axial loading. A total of seven specimens were tested. The influence of concrete shrinkage on the compressive behavior of the Composite Columns was also investigated. Significant confinement and Composite action resulted in enhanced compressive behavior. The addition of a shrinkage reducing agent was found to further improve the compressive behavior of the Composite Columns. An analytical model was developed to predict the behavior of the Composite Columns under axial loading.