Steel-Concrete Composite Columns

1997 ◽  
Vol 1594 (1) ◽  
pp. 57-63
Author(s):  
Richard W. Furlong
Keyword(s):  
Structural Steel ◽  
Slenderness Ratio ◽  
Effective Interaction ◽  
Local Buckling ◽  
American Concrete Institute ◽  
Steel Tube ◽  
Concrete Core ◽  
Composite Columns ◽  
Steel Shape ◽  
Steel Shapes

Structural steel shapes and tubes can be used with concrete to produce structural components. The performance of such composite systems, is better than the sum of responses of the parts taken separately. In a concrete-filled steel tube caisson, for example, the steel casing resists flexural tension efficiently while confining the concrete core as the core resists axial compression, whereas it also stabilizes the steel casing. Concrete encasement of structural steel shapes can provide lateral stability to the steel shape, restraining local buckling as well as reducing the slenderness ratio below that of the steel shape alone. Concrete encasement serves as insulation for fire and shock loading. Characteristics of the structural behavior of composite columns are described as the basis for design recommendations. Strength design principles from Load and Resistance Factor Design of the American Institute of Steel and Construction and the American Concrete Institute are used in design. Shear transfer for the effective interaction of concrete and steel is considered, and requirements for transverse bar reinforcement of shear mechanisms are discussed. Design examples of strength estimates for two types of composite columns are included.

Experimental Investigation on Behavior of Slender Steel Reinforced Concrete Columns Subjected to Eccentric Load

2012 ◽  
Vol 256-259 ◽  
pp. 697-701
Author(s):  
Zhuo Han ◽  
Shao Fei Jiang ◽  
Zhi Ping Sun ◽  
Le Zhou
Keyword(s):  
Reinforced Concrete ◽  
Failure Modes ◽  
Slenderness Ratio ◽  
Concrete Strength ◽  
Axial Loading ◽  
Experimental Investigations ◽  
Eccentric Load ◽  
Composite Columns ◽  
Steel Reinforced Concrete ◽  
Steel Shape

The objectives of this research were to investigate the structural behavior of slender steel reinforced concrete (Referred to as SRC)composite columns subjected to eccentric axial loading. The test consisted of 10 slender columns, with rectangular section160×180mm, and steel shape I10 encased in concrete. The stirrup spacing was 150 mm; its diameter was 6 mm. The diameter of longitudinal reinforcing bars was 10 mm. Details of the experimental investigations including description of the test columns, failure modes and mechanisms, strain characteristics, and load-deformation responses are discussed. Effects of concrete strength, slenderness of columns, and eccentricity of axial loads on the load-carrying capacity of slender column are then presented. Based on these results, a range of slenderness ratio and eccentric ratio of slender SRC column is proposed.

Experimental Study on the Effect of Steel-Tube Replacement Ratio on the Eccentric Compression Bearing Capacity of Composite Column

2011 ◽  
Vol 415-417 ◽  
pp. 1421-1426
Author(s):  
Xu Hong Zhang ◽  
Quan Quan Guo
Keyword(s):  
Experimental Study ◽  
Bearing Capacity ◽  
Slenderness Ratio ◽  
Steel Tube ◽  
Ultimate Bearing Capacity ◽  
Test Results ◽  
Replacement Ratio ◽  
Composite Columns ◽  
Eccentric Compression ◽  
Improvement Effect

The improvement effect of the external concrete to stability of the core steel-tube was demonstrated by the steel-tube replacement ratio through experimental study. The test results show that, with the steel-tube replacement ratio increasing, the ultimate bearing capacity of composite columns increased correspondingly, and the ductility of composite columns was improved obviously also. Therefore, the steel-tube replacement ratio should be involved in the formula for calculating the ultimate bearing capacity of composite columns. By finite element method and regression analysis, the slenderness ratio is amended by the steel-tube replacement ratio and the calculation results of the eccentric compression bearing capacity agreed well with the test results．

scholarly journals Experimental Behaviour of Steel Tubular Columns for Varying in Filled Concrete

2017 ◽  
Vol 63 (4) ◽  
pp. 149-160 ◽  
Author(s):  
P. Sangeetha ◽  
R. Senthil
Keyword(s):  
Carrying Capacity ◽  
Slenderness Ratio ◽  
Steel Tube ◽  
Load Carrying Capacity ◽  
Concrete Core ◽  
Composite Action ◽  
Tubular Columns ◽  
Load Carrying ◽  
Cfst Columns ◽  
Quarry Dust

AbstractThis paper investigates the behaviour of axially-loaded tubular columns filled with M20 grade concrete and partially replaced concrete. The parameters varying in the study are slenderness ratio (13.27, 16.58 & 19.9), and normal M20 grade concrete, partially replaced quarry dust and concrete debris. The effects of the various concrete mixes and composite action between the steel tube and the concrete core are studied and a graph visualizing the differences between the load carrying capacity and the axial deflection is plotted. Some of the performance indices like the Ductility Index (DI), Concrete Contribution Ratio (CCR), Confinement Index (θ) and Strength Index (SI) are also evaluated and compared amongst the CFST columns. From the results it has been noted that an increase in the L/D ratio decrease the behaviour of the composite columns irrespective of the in filled materials. The composite action was achieved in the CFST columns filled with partially replaced quarry dust and concrete debris when compared with hollow steel columns. The load carrying capacity of the CFST column increases by 32 % compared with the hollow tubular columns.

Research on Machanical Behavior of T-Shaped Concrete-Filled Steel Tubular Stub Columns with Steel Bone

2013 ◽  
Vol 639-640 ◽  
pp. 1077-1082
Author(s):  
Kai Lin Ju ◽  
Qiu Sheng Li ◽  
Guo Feng Du ◽  
Yi Li
Keyword(s):  
Local Buckling ◽  
Steel Tube ◽  
Experimental Results ◽  
Concrete Core ◽  
Concrete Filled Steel Tube ◽  
Tubular Columns ◽  
Calculation Results ◽  
New Type ◽  
Stub Columns ◽  
Tube Structure

Concrete-filled steel tube structure is one of the important load-bearing systems of modern high-rise building.The research indicate that concrete-filled steel tube structure has a good static and seismic performance,and concrete-filled steel tubular component is always used as axial compression and compression-bending component.However,what about the mechanical behavior of this combinational structure (concrete-filled steel tubular columns with steel bone built-in)? So there is a new type of special-shaped cross-section of composite structure,that is the T-shaped concrete-filled steel tubular columns with steel bone.The research about this structure is less throughout domestic and foreign.So the axial compressive experiments of six T-shaped concrete-filled steel tubular stub columns, five with and one without steel bone, were carried out. The effects of tube confining factor, bone indicator on the axial compressive behavior of the columns are analyzed. Experimental results indicate that the ultimate strength of the T-shaped steel tubular stub columns with steel bone increases, can be increased by 71.7%.And that the setting of steel bone improves the confinement of the concrete core, delays or even avoids the local buckling of the steel tube before the stress attains the yield strength. The ductility of the columns is also greatly increased.And at last in this paper, use of static equilibrium conditions and limit yield conditions,and in reference to literature[1],the calculation equation of compression capacity of this combinational column is derived.Moreover,calculation results according to the formula in this paper are in good agreement with the experimental results. The conclusions might be used as reference to structural design and plan.

scholarly journals Bearing Capacity of Hollow GFRP Pipe-Concrete-High Strength Steel Tube Composite Long Columns Under Eccentrical Compression Load

2021 ◽  
Vol 8 ◽  
Author(s):  
Jing Ji ◽  
Wen Zeng ◽  
Ruili Wang ◽  
Hongguo Ren ◽  
Lei Zhang ◽  
...  
Keyword(s):  
Bearing Capacity ◽  
High Strength Steel ◽  
Slenderness Ratio ◽  
Constitutive Models ◽  
Ductile Failure ◽  
High Strength ◽  
Steel Tube ◽  
Statistical Regression ◽  
Compression Load ◽  
Composite Columns

To investigate the bearing capacity of the hollow Glass Fiber Reinforced Polymer (GFRP) pipe-concrete-steel tube composite long columns subjected to eccentrical compression load, 33 hollow GFRP pipe-concrete-steel tube composite long columns have been designed. The slenderness ratio (λ), compressive strength of concrete cube (fcu), eccentricity (e) and so on are the main parameters. Based on constitutive models for steel, GFRP and confined concrete, numerical simulation of the hollow GFRP pipe-concrete-high strength steel tube composite long columns has been carried out by using software ABAQUS. The rationality of the constitutive models and modeling method has been verified by comparing the experimental and simulated load-displacement curves. The influence of different parameters on the mechanical behavior of this kind of column has been investigated. Results show that with the increasing of t1, t2 and fcu, the ultimate eccentrical compression bearing capacity of the specimen increases. With the increasing of e, the ultimate displacement of the specimens increases, while the ultimate eccentrical compression bearing capacity decreases. The eccentricity has a significant influence on the ultimate eccentrical compression bearing capacity. With the increasing of λ, the ultimate eccentrical compression bearing capacity of the specimens gradually decreases. The specimens suffer from ductile failure. The formula of the ultimate eccentrical compression bearing capacity of the composite columns is obtained by statistical regression. The study can provide theoretical support for the application of the composite columns in practical engineering.

Experimental Investigation to Evaluate the Behavior of Concrete-Filled Steel Tubular Columns under the Effect of the Distribution of the ‎Total Steel Area between the Internal Concrete Core and the External Steel Tube

2021 ◽  
Vol 54 ◽  
pp. 86-99
Author(s):  
Yasser Riffat Tawfic ◽  
Ahmad Saudi A. Sayed ◽  
Mohamed A. Eid ◽  
L.M. Abd El-Hafaz
Keyword(s):  
High Efficiency ◽  
Load Capacity ◽  
Steel Tube ◽  
Cross Sectional Area ◽  
Experimental Program ◽  
Sectional Area ◽  
Concrete Core ◽  
Cross Sectional ◽  
Composite Columns ◽  
Shear Connectors

Composite columns are generally installed in high-rise buildings and bridges. As well as being smaller and lighter than conventional reinforced concrete columns, composite columns offer high efficiency and ductility. In this research, experimental and analytical studies were carried out to investigate the optimal distribution of the ‎total steel area of the Concrete-Filled Hollow Steel Tube (CFHST) columns; the experimental program included 20 CFHST columns. ‎The main variables of the experimental study were the distribution of the total steel cross-sectional area over the internal concrete core (steel reinforcement) and the external steel tube, the cross-sectional shape, the width-to-breadth ratio t/b, and the presence or absence of shear connectors. In addition, using equations of different codes, comparison was conducted between the experimental and analytical results. For a constant steel cross-sectional area, the use of internal steel bars and external steel tubes, together with the use of shear connectors, was found to exhibit a better ultimate load capacity, stiffness, and ductility for the CFHST columns.

Axial Load Behavior of Rectangular CFT Stub Columns with Binding Bars

2007 ◽  
Vol 10 (5) ◽  
pp. 551-565 ◽  
Author(s):  
Jian Cai ◽  
Yue-Ling Long
Keyword(s):  
Ultimate Strength ◽  
Axial Load ◽  
Local Buckling ◽  
Concrete Core ◽  
Cross Sectional ◽  
Composite Columns ◽  
Proposed Model ◽  
Load Behavior ◽  
Stub Columns ◽  
Strength And Ductility

This paper presents an experimental study on the axial load behaviour of rectangular concrete-filled steel tubular (R-CFT) stub columns with binding bars. Eight specimens were concentrically loaded in compression to failure in order to investigate the effects of the binding bars, depth-to-wall thickness ratio and cross-sectional aspect ratio on the ultimate strength and ductility of the composite columns. Experimental results indicate that the binding bars increase the confinement of the concrete core and delay local buckling of the tube. The results also show that R-CFT columns with binding bars have better ductility than those without binding bars. A model is proposed to predict the ultimate strength of the specimens. A comparison of the ultimate strengths between tests and design codes shows that the proposed model gives reasonable predictions of the ultimate strength of rectangular CFT stub columns with binding bars while the codes EC4 (1996), AIJ (1997) and GJB (2001) conservatively estimate the ultimate strength by 17.6%, 22.9% and 9.7% respectively.

scholarly journals Performance of Special-Shaped Concrete-Filled Square Steel Tube Column under Axial Compression

2020 ◽  
Vol 2020 ◽  
pp. 1-16 ◽  
Author(s):  
Zhen Wang ◽  
Xuejun Zhou ◽  
Fangshuai Wei ◽  
Mingyang Li
Keyword(s):  
Yield Strength ◽  
Failure Modes ◽  
Slenderness Ratio ◽  
Concrete Strength ◽  
Local Buckling ◽  
Steel Tube ◽  
Element Analysis ◽  
Fea Model ◽  
Compressive Performance ◽  
Square Steel Tube

The axial compressive performance of novel L-shaped and T-shaped concrete-filled square steel tube (L/T-CFSST) column was assessed in this study. Ten L/T-CFSST columns were tested to failure under axial load. The experimental data were used to determine various failure modes, bearing capacities, and load-displacement curves. The test parameters included the section form, steel tube thickness, steel yield strength, and slenderness ratio. The axial compressive performance of the L/T-CFSST column proved favorable, and each square steel tube showed strong cooperative performance. The failure mode of the stub column specimen (H/D ≤ 3) was strength failure caused by local buckling of the steel tube and that of the medium-long column member (H/D > 3) was instability failure caused by overall bending of the specimen. A finite element analysis (FEA) model was established and successfully validated by comparison against the test results. Based on the FEA model, parametric analyses were conducted to investigate the effects of steel tube thickness, concrete strength, steel yield strength, and slenderness ratio. The ultimate loads obtained from the experiments and FEA were compared to the results calculated by the available design codes. A formula was established to calculate the axial compressive strength and stability bearing capacity of the L/T-CFSST column accordingly. The calculation results are in close agreement with the FEA and experimental results, and the proposed formula may provide a workable reference for practicing engineers.

Local buckling of structural steel shapes

2010 ◽  
Vol 66 (10) ◽  
pp. 1232-1247 ◽  
Author(s):  
Mina Seif ◽  
Benjamin W. Schafer
Keyword(s):  
Structural Steel ◽  
Local Buckling ◽  
Steel Shapes
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