Academic literature on the topic 'Concrete-filled steel tubular (CFST) columns'
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Journal articles on the topic "Concrete-filled steel tubular (CFST) columns"
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Cui, Ying, Meimei Song, Zhan Qu, Shanshan Sun, and Junhai Zhao. "Research on Damage Assessment of Concrete-Filled Steel Tubular Column Subjected to Near-Field Blast Loading." Shock and Vibration 2020 (November 23, 2020): 1–19. http://dx.doi.org/10.1155/2020/8883711.
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Concrete-filled steel tubular (CFST) columns are widely used in engineering structures, and they have many different cross section types. Among these, normal solid sections and concrete-filled double-skin steel tubular sections are often used. Although many studies have been conducted on CFST columns with these two section types, no studies have been conducted on their damage assessment under blast loading. In this study, experimental analysis and a numerical simulation method were integrated to evaluate the responses and assess the damage of two concrete-filled steel tubular (CFST) columns with different cross sections subjected to near-field blast loading. The results showed that for a scaled distance of 0.14 m/kg1/3, plastic bending deformation occurred on the surfaces of the two CFST columns facing the explosive. The antiexplosion performance of the normal solid-section (NSS) CFST column was better than that of the concrete-filled double-skin steel tubular (CFDST) column. The explosion centre was set at the same height as the middle of column, and the distributions of the peak pressure values of the two columns were similar: the peak pressures at the middle points of the columns were the greatest, and the peak pressures at the bottom were higher than those at the top. With the analysis of the duration of the positive pressure, the damage at the middle was the most severe when subjected to blast loading. Using pressure-impulse damage theory and the validated numerical simulations, two pressure-impulse damage evaluation curves for NSS and CFDST columns were established separately by analysing the experimental and simulation data. Finally, based on the two pressure-impulse damage evaluation curves, the two pressure-impulse damage criteria for these two different fixed-end CFST columns were defined based on the deflection of the surfaces facing the explosives. Furthermore, the mathematical formulae for the two different column types were established to generate pressure-impulse diagrams. With the established formulae, the damage of the CFST columns with these two cross section types can be evaluated. Damage to other similar CFST columns with different cross section types due to near-field blast loading can also be evaluated by this method.
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Ci, Junchang, Mizan Ahmed, Viet-Linh Tran, Hong Jia, and Shicai Chen. "Axial compressive behavior of circular concrete-filled double steel tubular short columns." Advances in Structural Engineering 25, no. 2 (October 19, 2021): 259–76. http://dx.doi.org/10.1177/13694332211046345.
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This article investigates the axial compressive performance of concrete-filled double steel tubular (CFDST) short columns composed of circular section loaded concentrically. An experimental program comprised of compression tests on short columns is carried out to examine their structural performance. Axial compression tests on conventional concrete-filled steel tubular (CFST) columns and double-skin concrete-filled steel tubular (DCFST) columns are also performed for comparison purposes. The test parameters include the diameter-to-thickness of the outer and inner steel tubes, concrete strength, and diameter ratio. The test results exhibit that CFDST short columns composed of the circular section have improved structural performance compared to its CFST and DCFST counterparts. A theoretical model is also presented to simulate the test ultimate strengths and load-axial strain relationships of CFDST columns. The existing design models proposed including the codified design specifications are evaluated against the collected test data for predicting the axial compressive strengths of circular CFDST columns. It is seen that the existing codified design models cannot yield their ultimate axial compressive strengths accurately. A practical artificial neural network (ANN) model is proposed to estimate the ultimate load of such columns loaded concentrically.
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Boukhalkhal, Said Hicham, Abd Nacer Touati Ihaddoudène, Luis Filipe Da Costa Neves, and Wafa Madi. "Dynamic behavior of concrete filled steel tubular columns." International Journal of Structural Integrity 10, no. 2 (April 8, 2019): 244–64. http://dx.doi.org/10.1108/ijsi-07-2018-0040.
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Purpose The purpose of this paper is to investigate the static and dynamic inelastic response of rigid and semi-rigid connections of steel structures with concrete-filled steel tube (CFST) columns built in high seismic areas, and to compare it with those with open section columns. Design/methodology/approach CFST columns are frequently used in moment resistant steel frames located in seismic areas due to their inherent advantages, including their ductility, energy absorption capacity as well as their high bearing capacity. The smart combination of steel and concrete makes it possible to benefit from the advantages of both components to the maximum. This research work presents the nonlinear dynamic response of moment resistant steel frames with CFST columns, with rigid or semi-rigid connections, built in high seismic areas, according to the Algerian seismic code RPA 99/2003, European EC8 and American FEMA 356 to show the nonlinear characteristics of this type of structures, and their advantages over steel frames with open section columns. Findings The paper presents the advantages of using CFST columns with rigid and semi-rigid connections on the seismic response of portal steel frames. A high performance level in terms of ductility, plastic hinges distribution and their order of appearance has been obtained. It also shows the low effect of seismic loading on the structural elements with CFST columns compared to structures with open section columns. Originality/value The investigation of the numerical results has shown the possibility of their use in the seismic areas for their adequate performance, and also with respect to the design limits specified in the seismic guidelines. In addition, this study represents a first step to develop seismic performance factors for steel structures with CFST columns in Algeria, where the Algerian code do not include a comprehensive specification for the composite steel structures.
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Bhatia, Sakshi, and Aditya Kumar Tiwary. "Concrete Filled Double Skinned Tubular Columns Subjected to Different Loading Conditions." IOP Conference Series: Earth and Environmental Science 889, no. 1 (November 1, 2021): 012050. http://dx.doi.org/10.1088/1755-1315/889/1/012050.
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Abstract The meteoric growth in light weight structures have opened on doors to many revolutionary concepts and innovations. Studies have manifested that the lowered weight of the structures somehow help to fight the material cost with a better seismic performance. The hollow core structures aimed reducing the structural weight with an improved structural performance as well. The Concrete filled double steel tubes (CFDST) can be taken as amalgamation of Hollow core columns and CFST i.e. single skinned columns. The co-relation of CFST and Hollow core columns gave birth to Concrete filled double skinned tubular columns (CFDST) which can possess the advantages of both the concepts. A sedulous review of concrete filled double skinned columns is being conveyed through this article. The behavior of confined concrete as well as the confining inner and outer steel in the CFDST model and its overall structural behavior is being succinctly reviewed in this article and a simultaneous comparison of CFDST columns to solid concrete/conventional columns is also being carried out where required.
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Yin, Fu Xin, Ji Tao Zhang, and Ping Bo Xu. "Summary of Research on Concrete Filled Steel Tubular (CFST) Columns." Advanced Materials Research 594-597 (November 2012): 891–95. http://dx.doi.org/10.4028/www.scientific.net/amr.594-597.891.
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Base on the achievement and research on the concrete filled steel tube (CFST), with 4 aspects: research on fundamental structural behavior, dynamic property, bonding theory of interface and research on the concrete filled square steel tube, summarize the findings about CFST and introduce the 4 stages of development of study of CFST. Point out that the research on the bond theory of interface between steel tube and core concrete and the concrete filled square steel tube are needed the further study and research.
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Sangeetha, P., and R. Senthil. "Experimental Behaviour of Steel Tubular Columns for Varying in Filled Concrete." Archives of Civil Engineering 63, no. 4 (December 1, 2017): 149–60. http://dx.doi.org/10.1515/ace-2017-0046.
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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.
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Liao, Fei Yu, and Yong Jin Li. "Experimental Behaviour of Concrete Filled Steel Tubes (CFST) with Initial Concrete Imperfection Subjected to Eccentric Compression." Applied Mechanics and Materials 174-177 (May 2012): 35–38. http://dx.doi.org/10.4028/www.scientific.net/amm.174-177.35.
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Gap between steel tube and concrete core could be recognized as a type of initial concrete imperfection in concrete-filled steel tubular (CFST) members. This paper is an attempt to study the effect of gap on the behaviour of concrete-filled steel tubular (CFST) columns subjected to eccentric compression. A total 14 specimens were tested and the main parameters were the gap type (circumferential gap and spherical-cap) and gap ratio. The influence of gap on the failure mode and ultimate strength of CFST columns were experimentally examined.
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Simon, Ms Sandra Mariam, and Ms Anju Thulasi. "Non Linear Analysis on CFDST columns with and without GFRP Wrapping." International Journal for Research in Applied Science and Engineering Technology 10, no. 7 (July 31, 2022): 612–16. http://dx.doi.org/10.22214/ijraset.2022.45379.
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Abstract: Concrete Filled Double Skin Steel Tube (CFDST) columns are modified form of Concrete Filled Steel Tubular (CFST) columns, developed by several researchers. CFDST column composed of two concentric steel tubes in which concrete is packed in between them. It is available in various geometrical shapes. CFDST have many advantages such as high strength, high bending stiffness, good seismic and fire performance. But it is found that CFDST columns have some disadvantages including ageing of structures, corrosion of steel tubes etc. which reduces the strength of the column. So, to prevent these drawbacks and to strengthen the structure, Glass Fiber Reinforced Polymer (GFRP) can be used as an external cover. The present study aims to do nonlinear static analysis of CFDST columns having different hollow ratio wrapped with and without GFRP under axial compression using ANSYS finite element analysis software.
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Anupama, P. N., Mathew Anu, and Kavya K. Kumar. "Numerical Analysis of Through-Beam Connection between CFST Column and RC Beam." Applied Mechanics and Materials 857 (November 2016): 159–64. http://dx.doi.org/10.4028/www.scientific.net/amm.857.159.
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The concrete filled steel tubular (CFST) columns consist of steel tube in-filled with concrete. The connections are the most important components of a CFST column and reinforced concrete beam structural system, since it combines the beams and the columns. In this paper, a through-beam ring connection for strengthening the joint between CFST column and RC beam is modeled using the finite element software package ANSYS and analysed the axial compressive behavior of the connection system. The numerical model is validated with the results available in the literature to confirm the structural efficiency of the ring beam connection system.
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A, Arunraj, Ashwin Kumar J, and Ajith J. "Behaviour of Basalt Fiber Reinforced Concrete Filled Mild Steel Tube." International Journal of Engineering & Technology 7, no. 4.2 (September 22, 2018): 15. http://dx.doi.org/10.14419/ijet.v7i4.2.19994.
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The present study is an attempt to understand the behavior of concrete filled steel tubular column under uniaxial load. A concrete-filled steel tubular (CFST) column is formed by filling a steel tube with concrete. It is well known that concrete- filled steel tubular (CFST) columns are currently being used in the construction of buildings, due to their excellent static and earthquake-resistant properties, such as high strength, high ductility, large energy absorption capacity, bending stiffness etc. The external strengthening of using basalt fiber reinforced concrete material is emerging as a new trend in enhancing the structural performance concrete filled steel tubular members to counteract the drawbacks of the past rehabilitation work. In this project we are going to study about strength of the steel and concrete by doing compression strength, flexural strength, push out and uniaxial compression test. The tests are carried out with the help of universal testing machine. The readings are recorded and graphs are plotted.
Dissertations / Theses on the topic "Concrete-filled steel tubular (CFST) columns"
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Zhao, H., R. Wang, Dennis Lam, C.-C. Hou, and R. Zhang. "Behaviours of circular CFDST with stainless steel external tube: Slender columns and beams." Elsevier, 2020. http://hdl.handle.net/10454/18141.
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NoIn this work, experimental and numerical investigations were performed on the behaviours of circular concrete filled double steel tubular (CFDST) slender columns and beams, in which the external tube employed stainless steel tube. Eighteen specimens, 12 slender columns and 6 beams, were tested to obtain the failure patterns, load versus deflection relationships and strain developments of stainless steel tube. A finite element (FE) model was developed and verified by experimental results. The validated FE model was then employed to investigate the effects of key parameters, including hollow ratio, eccentric ratio and material strength, on the load-carrying capacity. The load distribution among the components and contact stress between steel tube and sandwiched concrete were also analyzed. Finally, the design methods for CFDST, hollow CFST and solid CFST members with carbon steel external tube respectively suggested by Han et al. (2018), Chinese GB 50936-2014 (2014) and AISC 360-16 (2016) were employed to evaluate their applicability for the circular CFDST slender columns and beams with stainless steel outer tube.
The authors gratefully acknowledge the Shanxi Province Outstanding Youth Fund (No. 201701D211006) and the National Natural Science Foundation (No. 51838008).
The full-text of this article will be released for public view at the end of the publisher embargo on 9th Nov 2021.
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Alam, Md Iftekharul. "Behaviour of FRP strengthened steel tubular members subjected to transverse impact loading." Thesis, Queensland University of Technology, 2017. https://eprints.qut.edu.au/105782/1/Md%20Iftekharul_Alam_Thesis.pdf.
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This PhD thesis is devoted to contributing to the existing knowledge of FRP (Fibre Reinforced Polymer) strengthened metallic structural members subjected to dynamic impacts. The outcome of this research will be beneficial to design structures for mitigating damage and failure due to lateral impact forces from transportation accidents, explosive attacks or from flying debris. A new series of laboratory tests results along with computer based structural analyses are presented to understand the effectiveness of FRP strengthening of tubular structural members. FRP strengthening found to be a promising sustainable option for minimising structural damage and human casualty due to impact loads.
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Mollazadeh, Mohammad Hassan. "Load introduction into concrete-filled steel tubular columns." Thesis, University of Manchester, 2015. https://www.research.manchester.ac.uk/portal/en/theses/load-introduction-into-concretefilled-steel-tubular-columns(6750e9ae-b2c4-46d4-858f-c4a3f238439c).html.
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Concrete-Filled Steel Tubular (CFST) columns are increasingly being used because of their many advantages, including high strength, high ductility, and higher fire resistance than conventional steel or concrete columns of the same size. In order to maximise the advantages of CFST column, composite action of the column should be ensured. In realistic structures, the load is not directly applied to the entire CFST column section and is introduced from the beam-column connection. Simple shear connections, which are usually preferred in constructions, are only connected to the external face of the steel tube and there is an issue about how this load is introduced to the concrete core, through the bond at the steel/concrete interface. There are fundamental errors in the load introduction mechanism assumed in various current design methods. Furthermore, based on this erroneous load introduction mechanism, construction methods, such as placing shear connectors inside the steel tube or using through-column plates, are recommended to ensure complete load introduction. However, these methods are either impractical or uneconomical. The aim of this project, therefore, is to develop a thorough understanding of the load introduction mechanism and to use the new insights to assess design implications, for both ambient temperature and fire safety design. The research has been conducted through physical testing, extensive numerical modelling and detailed analytical derivations. A series of new load introduction tests, in which square CFST columns are loaded through simple fin plate connections, are carried out. These tests are designed to investigate the effects of changing column lengths below and above the connection, the effectiveness of using shear connectors inside the steel tube below the connection (according to Eurocode 4) and using a cap plate on the column top for load introduction into the concrete core. The test results indicate that the connection load is introduced to the concrete core through the column length above and within the connection or the cap plate on top of the column. This is different from the currently assumed mechanism of load introduction which assumes that load introduction occurs from underneath the connection. Below the connection, there is transfer of forces from the steel tube to the concrete core, but the total force in the column remains unchanged. Consequently, using shear connectors below the connection is ineffective in increasing CFST column strength, as has been demonstrated by the tests. The physical tests are supplemented by an extensive numerical parametric study to check whether the conclusions are applicable to different design conditions and to provide data for development of a new design method. The parameters include: section geometry (square, circular, and rectangular), position of load application to CFST column, dimensions of the square column cross-section, steel tube thickness, connection length, column length above the connection, column length below the connection, and maximum bond stress at the steel-concrete interface. The numerical simulation results confirm the experimental observations. Furthermore, the numerical simulation results indicate that the entire column length and the entire perimeter of the steel-concrete interface above and within the connection are engaged in load introduction. Based on the experimental and numerical simulation results, a simple calculation method has been proposed to calculate the column cross-section resistance under compression. According to this equation, the concrete compression resistance to the composite column is the minimum of the plastic resistance or the bond strength within and above the connection. This gives rise to a “concrete strength reduction factor” to account for incomplete load introduction, being the ratio of the load introduced to the concrete core through the interface bond to the concrete plastic resistance. Based on the new load introduction calculation method and using representative values of column dimensions and concrete cylinder strength, it has been demonstrated that complete load introduction can be achieved in almost all practical arrangements of concrete-filled tubular construction. For slender CFST column design, this concrete strength reduction factor should also be used to calculate the CFST column cross-section flexural stiffness. For a CFST column under combined axial compression and bending, the concrete strength reduction factor should be used when calculating the compression force, but should be ignored when calculating the bending resistance because composite action is not necessary for bending of the CFST column. The new load introduction mechanism induces additional compression in the concrete core and possible tension in the steel tube above the connection. Therefore, the concrete core of the column above the connection in multi-storey construction should be designed to resist the additional compression force. For the steel tube, in ambient temperature design, the steel contribution ratio (steel section resistance/plastic resistance of composite cross-section) of the top floor column should be at least 0.25. For fire resistance design, the steel contribution ratio of the top floor columns, those on the floor below the top floor, and those two floors below the top floor, should not be less than 0.5, 0.33, and 0.25 respectively.
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Dong, Chunxiao, and 董春宵. "Uni-axial behaviour of concrete-filled-steel-tubular columns with external confinement." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2013. http://hdl.handle.net/10722/195975.
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This thesis studies the uni-axial behaviour of circular double-skinned concrete-filled-steel-tubular (CFST) columns with external confinement in form of external steel rings. Particular attention is paid to the experimental behaviour of double-skinned CFST columns and theoretical model for evaluating the loadcarrying capacity of un- and ring-confined double-skinned CFST columns.
Experimental studies on circular double-skinned CFST columns with various spacing of confinement, concrete strength and hollow ratio were conducted and discussed comprehensively. The mechanical properties of double-skinned CFST columns such as elastic stiffness, elastic strength, load-carrying capacity and ductility are presented. From the result, it is found that the elastic stiffness, elastic strength, load-carrying capacity and ductility are enhanced by installing the external steel rings to the outer tube as external confinement. To verify the effectiveness of external steel rings, the Poisson’s ratios of the double-skinned CFST columns are listed and found to be similar to that of concrete so that a perfect bonding is maintained. To emphasis the excellent performance of double-skinned CFST columns with external rings under uni-axial compression, the load-carrying capacity, elastic strength and elastic stiffness are compared to those of single-skinned CFST columns and reinforced concrete columns.
To fill up the gap that no design model is provided in Eurocode 4 (EC4) for confined double-skinned CFST columns, a theoretical model based on the force equilibrium condition is proposed for evaluating the load-carrying capacity of both un- and ring-confined double-skinned CFST columns. The model takes into account the composite action between the steel tubes and core concrete. To verify the proposed model, numerous test results obtained by the author and other researchers are used for comparing the theoretical results.
According to the above theoretical model above, a parametric study is carried out to investigate the effect of various geometry and material properties on the load-carrying capacity of double-skinned CFST columns. The confining pressure is expressed in terms of geometry and material factors. A simplified design formula is proposed to facilitate the preliminary design of double-skinned CFST columns with and without external confinement.published_or_final_version
Civil Engineering
Master
Master of Philosophy
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Chao, Min, of Western Sydney Hawkesbury University, Faculty of Science and Technology, and School of Construction and Building Sciences. "The design and behaviour of concrete filled steel tubular beam-columns." THESIS_FST_CBS_Chao_M.xml, 2000. http://handle.uws.edu.au:8081/1959.7/92.
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Concrete filled steel tubular (CFST) columns are widely used in building and infrastructure projects throughout the world.Compared with other form of construction CFST columns offer superior structural performance and speed and ease of construction.Design procedures and recommendations provided in most of the design codes are often tedious and complex. There have been attempts to simplify the design procedure by providing a simplified expression to predict the capacity of a CFST under a general loading condition.In this thesis a rigorous analysis procedure was presented for the analysis of CFST beam-columns under general loading conditions.All the analytical results were verified by comparisons with the available test results and current ACI, AISC AND Eurocode 4 design codes. The comparisons demonstrated that the proposed numerical equations are accurate, and slightly conservative. Based on the numerical analysis, a simple and easy to follow calculation procedure was proposed for design of CFST columns under either uniaxial or biaxial bending moment and axial load.Doctor of Philosophy (PhD)
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Chao, Min. "The design and behaviour of concrete filled steel tubular beam-columns /." View thesis View thesis, 2000. http://library.uws.edu.au/adt-NUWS/public/adt-NUWS20030429.154344/index.html.
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Luo, Lie, and 罗冽. "Uni-axial behavior of normal-strength concrete filled steel tubular columns with external confinement." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2012. http://hub.hku.hk/bib/B49618210.
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This thesis proposes two forms of external confinement for concrete filled steel tubular (CFST) columns. The confinement efficiency is studied by examining the axial strength enhancement and ductility improvement of the CFST columns with external confinement.
Due to the heavy demand of confining steel to restore the column ductility in seismic regions, it is more efficient to confine these columns by hollow steel tube to form CFST column. Compared with transverse reinforcing steel, steel tube provides a stronger and more uniform confining pressure to the concrete core, and reduces the steel congestion problem for better concrete placing quality. The CFST columns are therefore characterised by higher strength, ductility and large energy absorption before failure.
However, a major shortcoming of CFST columns is the imperfect steelconcrete interface bonding occurred at the elastic stage as steel dilates more than concrete in compression. This adversely affects the confining effect and decreases the elastic modulus. To resolve the problem, it is proposed in this thesis to use external steel confinement in the forms of rings and ties to restrict the dilation of steel tube. For verification, a series of uni-axial compression test was performed on some CFST columns with external steel rings and ties. From the results, it was found that the external steel rings could improve both the axial strength and stiffness of the CFST columns significantly. However, the steel ties could not improve either the axial strength or elastic stiffness significantly. The confining efficiency was then investigated by comparing the strength of these confined-CFST columns with the reinforced concrete (RC) columns counterparts with the same concrete and steel volume. It is evident that the axial strength of CFST columns is much higher than the RC columns, which suggests that the application of CFST columns can utilise less construction materials and reduce the demolition waste.
A theoretical model is also proposed for predicting the axial strength of ring-confined CFST columns. Comparison between the predicted results and the test results obtained by the author and other researchers shows that the proposed model gives good estimation for both unconfined and confined CFST columns.published_or_final_version
Civil Engineering
Master
Master of Philosophy
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Elsawaf, Sherif Ahmed Elkarim Ibrahim Soliman. "Robustness of connections to concrete-filled steel tubular columns under fire during heating and cooling." Thesis, University of Manchester, 2012. https://www.research.manchester.ac.uk/portal/en/theses/robustness-of-connections-to-concretefilled-steel-tubular-columns-under-fire-during-heating-and-cooling(b1ef6849-2d59-4e73-b0c9-c57d0293ec51).html.
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Joint behaviour in fire is currently one of the most important topics of research in structural fire resistance. The collapse of World Trade Center buildings and the results of the Cardington full-scale eight storey steel framed building fire tests in the UK have demonstrated that steel joints are particularly vulnerable during the heating and cooling phases of fire. The main purpose of this research is to develop robust joints to CFT columns that are capable of providing very high rotational and tying resistances to make it possible for the connected beam to fully develop catenary action during the heating phase of fire attack and to retain integrity during the cooling phase of fire attack. This research employed the general finite element software ABAQUS to numerically model the behaviour of restrained structural subassemblies of steel beam to concrete filled tubular (CFT) columns and their joints in fire. For validation, this research compared the simulation and test results for 10 fire tests previously conducted at the University of Manchester. It was envisaged that catenary action in the connected beams at very large deflections would play an important role in ensuring robustness of steel framed structures in fire. Therefore, it was vital that the numerical simulations could accurately predict the structural behaviour at very large deflections. In particular, the transitional behaviour of the beam from compression to catenary action presented tremendous difficulties in numerical simulations due to the extremely high rate of deflection increase. This thesis will explain the methodology of a suitable simulation method, by introducing a pseudo damping factor. The comparison between the FE and the experimental results demonstrates that the 3-D finite element model is able to successfully simulate the fire tests. The validated ABAQUS model was then applied to conduct a thorough set of numerical studies to investigate methods of improving the survival temperatures under heating in fire of steel beams to concrete filled tubular (CFT) columns using reverse channel connection. This study investigated five different joint types of reverse channel connection: extended endplate, flush endplate, flexible endplate, hybrid flush/flexible endplate and hybrid extended/flexible endplate. The connection details investigated include reverse channel web thickness, bolt diameter and grade, using fire-resistant (FR) steel for different joint components (reverse channel, end plate and bolts) and joint temperature control. The effects of changing the applied beam and column loads were also considered. It is concluded that by adopting some of the joint details to improve the joint tensile strength and deformation capacity, it is possible for the beams to develop substantial catenary action to survive very high temperatures. This thesis also explains the implications on fire resistant design of the connected columns in order to resist the additional catenary force in the beam. The validated numerical model was also used to perform extensive parametric studies on steel framed structures using concrete filled tubular (CFT) columns with flexible reverse channel connection and fin plate connection to find means of reducing the risk of structural failure during cooling. The results lead to the suggestion that in order to avoid connection fracture during cooling, the most effective and simplest method would be to reduce the limiting temperature of the connected beam by less than 50°C from the limiting temperature calculated without considering any axial force in the beam.
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Pascual, Pastor Ana María. "Fire behaviour of blind-bolted connections to concrete filled tubular columns under tension." Doctoral thesis, Universitat Politècnica de València, 2015. http://hdl.handle.net/10251/53240.
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[EN] Concrete filled steel tubular columns have many advantages in terms of bearing capacity, aesthetics, execution and fire resistance, thanks to the collaborative work of both materials steel and concrete. The effort made in the last decades to rise a high understanding of their behaviour subjected to different loads and assuming multiple variations has resulted in the wide spread of its use between the designers. Nonetheless, how to solve the connection with I-beams is still a handicap and requires a specific study.
One of the most common and popular solution to connect open section steel beams (I-beams) to open section steel columns are endplate connections. In the cases of columns with hollow section, special fastenings are needed, which are able to be tightened from one external side and are denominated blind-bolts. Nowadays, there are several fastener systems that allow these types of connections. The characterization of their response and their capacity to support different loads is the objective of several investigations, where the geometrical definition and the material properties are crucial parameters.
Despite the promising results of these connections at room temperature regarding their capability to resist bending moments, their performance is un-known at high temperatures. Therefore, the aim of this thesis is the study of the tensile behaviour of blind-bolts in endplate connections to concrete filled tubular columns at elevated temperatures and subjected to bending moment.
Primarily, the research comprises the understanding of the pure thermal transfer problem. The temperature distribution through the connection section is obtained experimental and numerically. The thermal parameters that characterize the connections response are determined through the calibration of the numerical models with the experiments. Secondly, the blind-bolt capacity under pull out and at high temperatures is under analysis. During the fire the temperature increases while connection transmits loads from the beam to the column, the objective of this dissertation is to know how the mechanical response of the pulled blind-bolts changes under these conditions. Thus, the study of the material properties dependent on the temperature and their effect on the connection response is covered by the investigation. Furthermore, the influence of the concrete and the type of fastener is a highlighted aspect through the thermal and the fire analysis.
Finally, the reliability of these connections to comply with requirements of 30 minutes fire exposure before the collapse is evaluated.
As a result, valuable Finite Element models able to simulate the thermal and thermo-mechanical behaviour of the connection are developed, providing useful behavioural patterns of the blind-bolts. Among the main conclusions, it is noted the temperature reduction due to concrete core in concrete filled columns compared to hollow sections, in the exposed bolt surface means 100ºC less. Conversely, a longer bolt shank of the fastener system embedded in concrete has a negligible effect on the temperature of the resistant part of the bolt. Regarding the fire capacity, the concrete core in the steel tube columns presents significant benefits in terms of fire resistance time and connection stiffness. Besides, the bolt anchorage enhances the stiffness at elevated temperatures, however, the failure of the shank next to the bolt head causes that the anchorage does not mean an improvement on the fire time resistance.[ES] Las columnas tubulares de acero rellenas de hormigón presentan múltiples ventajas en términos de capacidad de carga, estética, ejecución y resistencia al fuego, gracias a la acción combinada de acero y hormigón. El esfuerzo realizado en las últimas décadas por conocer su comportamiento frente a diferentes cargas y bajo distintos parámetros ha dado lugar a una amplia difusión de su uso entre los diseñadores. No obstante, la forma de resolver la conexión con vigas de sección en I sigue siendo un hándicap y requiere un estudio específico. Una de las soluciones más comunes y populares para conectar las vigas de acero de sección abierta (vigas I) a columnas de acero de sección abierta es la conexión con chapa de testa, que en el caso de sección hueca requiere de tornillos especiales denominados tornillos ciegos, puesto que reciben el par de apriete desde una cara de la sección. En la actualidad existen diversos sistemas de fijación que permiten este tipo de conexiones y cuya respuesta y caracterización es objeto de numerosas investigaciones. En este sentido, la definición geométrica de la unión y las propiedades de los materiales son parámetros cruciales en el rendimiento de la conexión. La presente tesis analiza el comportamiento de los tornillos ciegos en el área traccionada de conexiones de placa de testa a columnas tubulares de acero rellenas de hormigón sometidas a momentos de flexión y a elevadas temperaturas. Las prestaciones de esta solución constructiva para la unión viga-columna tubular, junto con la ausencia de datos relacionados con su comportamiento en situación de incendio la convirtió en el objetivo del trabajo. En primer lugar, la investigación aborda el problema de transferencia de calor, analizando experimental y numéricamente la distribución de temperaturas en la sección de la conexión. En esta parte del estudio se obtienen los parámetros térmicos que caracterizan la respuesta térmica de la conexión a través de la calibración de los modelos numéricos con los datos experimentales. En segundo lugar, se realiza el estudio de la capacidad de los tornillos ciegos para soportar cargas de tracción en situación de incendio, es decir, se analiza cómo cambia el comportamiento de la conexión con sus características alteradas debido a las altas temperaturas. El estudio de las propiedades del material en función de la temperatura y su efecto sobre la respuesta de la conexión constituyen una parte importante de la investigación. Además, se evalúa la influencia del hormigón y el tipo de elemento de sujeción tanto en el comportamiento mecánico como termo-mecánico de la conexión. Por último, se estudia la capacidad de las uniones para cumplir con requerimientos de exposición al fuego de 30 minutos previamente al colapso. Como resultado de este trabajo se obtuvieron modelos de elementos finitos capaces de simular la conexión térmica y termo-mecánicamente, proporcionando patrones de comportamiento de gran utilidad en el diseño de las mismas. Entre las principales conclusiones, se observó la reducción de la temperatura en los tornillos gracias al núcleo de hormigón en columnas de hormigón lleno en comparación con secciones huecas, que ya en la superficie expuesta del tornillo se cuantificaba en 100ºC menos. Por el contrario, los elementos de fijación que presentaban mayor longitud de vástago de tornillo embebida en el hormigón, no generaban un efecto significativo sobre la temperatura de la parte resistente del perno. En cuanto a la capacidad resistente frente a fuego, el núcleo de hormigón supuso una mejora en términos de rigidez y de tiempo de resistencia al fuego. Sin embargo, el fallo de los pernos en una sección próxima a la superficie expuesta redujo el efecto esperado del anclaje del tornillo, que si bien implicaba una mayor rigidez de la conexión, no parecía mejorar el tiempo de resistencia a fuego. Finalmente se planteó la necesidad de
[CAT] Els pilars tubulars d'acer omplerts de formigó (CFT) presenten molts avantatges en termes de capacitat de carrega, estètica, execució i resistència al foc, gràcies a l'acció combinada de l'acer i el formigó. L'esforç realitzat en les darreres dècades per conèixer el seu comportament enfront a diferents càrregues i sota distints paràmetres ha donat lloc a una amplia difusió del seu ús entre el dissenyadors. No obstant això, la manera de resoldre la connexió amb bigues de secció en I, continua sent un handicap i requereix d'un estudi específic. Una de les solucions més comuns i populars per a connectar les bigues d'acer de secció oberta (bigues I) a columnes d'acer de secció oberta és la connexió amb 'chapa de testa', que en el cas de la secció buida requereix de perns especials denominats perns cecs perquè es rosquen des d'una cara de la secció. En l'actualitat existeixen diversos sistemes de fixació que permeten aquest tipus de connexions, la resposta i caracterització dels quals es l'objectiu de nombroses recerques. En aquest sentit, la definició geomètrica de la unió i les propietats dels materials son paràmetres crucials en el rendiment de la connexió. Aquesta tesi analitza el comportament dels perns cecs en l'àrea traccionada de connexions de 'chapa de testa', a pilars tubulars d'acer omplerts de formigó, sotmeses a moments de flexió i a elevades temperatures. Les prestacions d'aquesta solució constructiva per a la unió biga-pilar tubular junt amb l'absència de dades relacionades amb el comportament en situació d'incendi, la van convertir en l'objectiu d'aquest treball. En primer lloc, la recerca aborda el problema de transferència de calor, analitzant tant experimental com numèricament la distribució de temperatures en la secció de la connexió. En aquesta part de l'estudi, s'obtenen el paràmetres tèrmics que caracteritzen la resposta tèrmica de la connexió mitjançant el calibratge del models numèrics amb les dades experimentals. En segon lloc, es realitza l'estudi de la capacitat dels perns cecs per a suportar càrregues de tracció en situació d'incendi, es a dir, s'analitza com canvia el comportament de la connexió amb les seues característiques alterades degut a les altes temperatures. L'estudi de les propietats del material en funció de la temperatura i el seu efecte en la resposta de la connexió formen també part de la recerca. Un contingut important d'aquest treball consisteix en determinar l'influencia del formigó i el tipus d'element de fixació tant en el comportament mecànic com termo-mecànic de la connexió. Per últim, s'estudia la capacitat de les unions per a complir amb els requeriments d'exposició al foc de 30 minuts prèviament al col·lapse. Com a resultat d'aquest treball s'obtingueren models d'elements finits amb capacitat per a simular el comportament tèrmic i termo-mecànic de la connexió, proporcionant patrons de comportament de gran utilitat en el disseny. Entre les principals conclusions, es va observar la reducció de la temperatura en els perns gràcies al nucli de formigó en pilars omplerts de formigó en comparació amb el pilars buits, on ja en la superfície esposada del cargol es quantificava en 100 ºC menys. Pel contrari, els elements de fixació que presentaven major longitud de embeguda en el formigó, no generaven un efecte significatiu en la temperatura de la part resistent del pern. En quant a la capacitat resistent davant del foc, el nucli de formigó va suposar una millora en termes de rigidesa i de temps de resistència al foc. Tanmateix, la fallada dels perns en una secció pròxima a la superfície esposada va reduir l'efecte esperat de la fixació del pern, que si be implicava una major rigidesa de la connexió, no semblava millorar el temps de resistència al foc. Finalment, es va plantejar la necessitat de aprofundir en l'anàlisi incorporant un major rang de paràmetres.
Pascual Pastor, AM. (2015). Fire behaviour of blind-bolted connections to concrete filled tubular columns under tension [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/53240
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Jones, Mark Hadyn. "Tensile and shear behaviour of fin-plate connections to hollow and concrete-filled steel tubular columns at ambient and elevated temperatures." Thesis, University of Manchester, 2008. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.504745.
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Following recent events such as the World Trade Center building collapse and the Cardington large scale structural fire research program, the fire behavior of connections has now become an important research subject. This thesis presents the results of experimental, numerical and theoretical studies into the behavior of simple welded fin-plate to concretefilled tubular (CFT) columns loaded by tensile or shear force. Such connections represent a simple single-sided joint solution to steel CFTs which are considered an attractive and robust structural element. Experiments have been performed at both ambient and elevated temperatures against the results of which numerical finite element models have been validated. The ranges of parameters encompassed by the tests include column cross-section shape; column and finplate thickness; concrete in-fill; elevated temperatures and connection lever arm. The observed failure modes include fracture of the fin-plate and tearing out of the tube around the welds. By considering the results of previously published research, the current design method for similar connections under purely tensile load, in CIDECT Guide 9, based on a deformation limit of 3% of the tube width is shown to be inadequate when evaluating the ultimate strength of such connections. By comparing the results from the current test program which failed in the fin-plate with Eurocode guidance for failure of a fin-plate alone under shear and bending load it is shown that the column face influences the overall connection strength regardless of failure mode. Concrete in-fill is observed to significantly increase the strength of connections over empty specimens, and circular column specimens were observed to exhibit greater strength than similarly proportioned square columns. When validating the numerical model against elevated temperature tests it was found that the strength reduction factors suggested by Eurocode for steel at elevated temperature are appropriate. The numerical models developed have been used to perform extensive parametric studies from which simple hand calculation methods have been developed for evaluating the strength of the column component of square CFTs under either tensile or shear load imparted through a fin-plate connection. The simple hand calculation procedures are based upon defining a rigid plate deformation pattern for the connection and then applying the internal work principle. For connections under shear load a method is presented for combining the column failure load with the fin-plate failure derived from existing Eurocode guidance. Both simple hand calculation methods are compared favorably with available test results. A limited number of tests and numerical validation have also been performed for reverse channel to CFT connections loaded in shear at both ambient and elevated temperatures.
Books on the topic "Concrete-filled steel tubular (CFST) columns"
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Al-Rawdan, Abdel-Kareem. Steel beam connections to concrete-filled tubular columns. Manchester: University of Manchester, 1996.
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Lu, Yue Qing. The flexural behaviour of concrete-filled hollow structural sections. Edmonton, Alta., Canada: Dept. of Civil Engineering, University of Alberta, 1992.
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Patel, Vipulkumar, Qing Quan Liang, and Muhammad N. S. Hadi. Concrete-Filled Stainless Steel Tubular Columns. Taylor & Francis Group, 2020.
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Patel, Vipulkumar, Qing Quan Liang, and Muhammad Hadi. Concrete-Filled Stainless Steel Tubular Columns. Taylor & Francis Group, 2018.
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Patel, Vipulkumar, Qing Quan Liang, and Muhammad Hadi. Concrete-Filled Stainless Steel Tubular Columns. Taylor & Francis Group, 2018.
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Patel, Vipulkumar, Qing Quan Liang, and Muhammad Hadi. Concrete-Filled Stainless Steel Tubular Columns. Taylor & Francis Group, 2018.
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Patel, Vipulkumar, Qing Quan Liang, and Muhammad Hadi. Concrete-Filled Stainless Steel Tubular Columns. Taylor & Francis Group, 2018.
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R, Bergmann, and Comité international pour l'étude et le développement de la construction tubulaire, eds. Design guide for concrete filled hollow section columns under static and seismic loading. Köln: TÜV Rheinland, 1995.
Find full textBook chapters on the topic "Concrete-filled steel tubular (CFST) columns"
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Patel, Vipulkumar Ishvarbhai, Qing Quan Liang, and Muhammad N. S. Hadi. "Nonlinear analysis of CFSST short columns." In Concrete-Filled Stainless Steel Tubular Columns, 13–59. Boca Raton: Taylor & Francis, CRC Press, [2019]: CRC Press, 2018. http://dx.doi.org/10.1201/9781351005708-2.
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Patel, Vipulkumar Ishvarbhai, Qing Quan Liang, and Muhammad N. S. Hadi. "Nonlinear analysis of circular CFSST slender columns." In Concrete-Filled Stainless Steel Tubular Columns, 61–93. Boca Raton: Taylor & Francis, CRC Press, [2019]: CRC Press, 2018. http://dx.doi.org/10.1201/9781351005708-3.
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Patel, Vipulkumar Ishvarbhai, Qing Quan Liang, and Muhammad N. S. Hadi. "Nonlinear analysis of rectangular CFSST slender columns." In Concrete-Filled Stainless Steel Tubular Columns, 95–124. Boca Raton: Taylor & Francis, CRC Press, [2019]: CRC Press, 2018. http://dx.doi.org/10.1201/9781351005708-4.
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Han, Lin-Hai, Dennis Lam, and David A. Nethercot. "Design of CFDST Columns." In Design Guide for Concrete-Filled Double Skin Steel Tubular Structures, 21–48. First edition. | Boca Raton, FL : CRC Press/Taylor & Francis Group, [2019]: CRC Press, 2018. http://dx.doi.org/10.1201/9780429440410-3.
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Phan, Hao D., and Ker-Chun Lin. "Seismic Performance of Concrete Filled Steel Tubular (CFST) Columns with Variously Axial Compressive Loads." In Lecture Notes in Mechanical Engineering, 915–25. Singapore: Springer Singapore, 2021. http://dx.doi.org/10.1007/978-981-16-3239-6_71.
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Phan, Hao D., Ker-Chun Lin, and Hieu T. Phan. "Numerical Simulation of Full-Scale Square Concrete Filled Steel Tubular (CFST) Columns Under Seismic Loading." In Lecture Notes in Mechanical Engineering, 875–89. Singapore: Springer Singapore, 2021. http://dx.doi.org/10.1007/978-981-16-3239-6_68.
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Patel, Vipulkumar Ishvarbhai, Qing Quan Liang, and Muhammad N. S. Hadi. "Introduction." In Concrete-Filled Stainless Steel Tubular Columns, 1–12. Boca Raton: Taylor & Francis, CRC Press, [2019]: CRC Press, 2018. http://dx.doi.org/10.1201/9781351005708-1.
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Han, Lin-Hai, and Wei Li. "Seismic Performance of Concrete-Filled Steel Tubular (CFST) Structures." In Seismic Design of Industrial Facilities, 361–68. Wiesbaden: Springer Fachmedien Wiesbaden, 2013. http://dx.doi.org/10.1007/978-3-658-02810-7_30.
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Geng, Yue, Gianluca Ranzi, Yu-yin Wang, Raymond Ian Gilbert, and Sumei Zhang. "State-of-the-art review on the time-dependent behaviour of composite steel-concrete columns." In Time-dependent behaviour and design of composite steel-concrete structures, 83–109. Zurich, Switzerland: International Association for Bridge and Structural Engineering (IABSE), 2021. http://dx.doi.org/10.2749/sed018.ch5.
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<p>This chapter presents a state-of-the-art review of the time-dependent behaviour of composite columns. The first part of the chapter outlines the available typologies and advantages of composite columns. This is followed by an overview of the time-dependent response of concrete (specific to composite columns) and an introduction to concrete confinement. The main part of the chapter is devoted to the state-of-the-art review on how concrete time effects influence the long-term and ultimate behaviour of concrete-filled steel tube (CFST) columns, and on the combined effects produced by sustained loading and chloride corrosion on CFST columns. The review then deals with the long-term behaviour of concrete-filled double skin tube (CFDST) and encased composite columns. The final parts of the chapter provide a review of the time-dependent differential axial shortening (DAS) in vertical components of multi-storey buildings and on the long-term response of arch bridges.</p>
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Thai, Huu-Tai, and Son Thai. "Reliability Evaluation of Eurocode 4 for Concrete-Filled Steel Tubular Columns." In Lecture Notes in Civil Engineering, 323–28. Singapore: Springer Singapore, 2019. http://dx.doi.org/10.1007/978-981-15-0802-8_49.
Full textConference papers on the topic "Concrete-filled steel tubular (CFST) columns"
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Sulthana, U. Mashudha, and S. Arul Jayachandran. "Investigations on global buckling behaviour of concrete-filled double-skinned steel tubular columns." In 12th international conference on ‘Advances in Steel-Concrete Composite Structures’ - ASCCS 2018. Valencia: Universitat Politècnica València, 2018. http://dx.doi.org/10.4995/asccs2018.2018.7144.
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Concrete-Filled Double-skinned Steel Tubular columns (CFDST) are proved to possess exceptional structural resistance in case of fire and multi-hazard situations. This superior quality of CFDST makes it preferable in long column applications. However, studies on the long column behaviour of CFDST is very few, and their results are not in line with the behaviour of CFST long columns. Whereas, several researches on stub column CFDST shows that, the axial compression behaviour of CFDST is similar to CFST. In this paper, selected results (4 numbers of circular CFDST specimens) from a large test data is presented. Axial compression behaviour of long column CFDST specimens is studied, with non-dimensional slenderness λ around 1.0, and hollowness ratio as the governing parameter for study. Test results namely, axial load carrying capacity, axial deformation and lateral deflection are presented in this paper. Numerical models are also developed and validated with the experimental results, to carry out more parametric studies. Further, the experimental axial capacity values are compared with modified capacity equations from EC4 and AISC. Results show that extended EC4 and AISC equations gives conservative predictions for CFDST column even in the long column range. Moreover, the initial imperfections in the specimen and their corresponding boundary conditions for load application, are found to be governing parameters in long column buckling study.
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Ibáñez, Carmen, Luke Bisby, David Rush, Manuel L. Romero, and Antonio Hospitaler. "Analysis of concrete-filled steel tubular columns after fire exposure." In 12th international conference on ‘Advances in Steel-Concrete Composite Structures’ - ASCCS 2018. Valencia: Universitat Politècnica València, 2018. http://dx.doi.org/10.4995/asccs2018.2018.7193.
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Concrete filled steel tubular (CFST) columns have a high probability to resist high temperatures compared to steel structures, whose evaluation after a fire is limited by the resulting deformation. A better understanding of the behaviour of CFST columns after a fire, affected by the maximum temperature achieved by the concrete infill, is required to properly estimate their residual strength and stiffness in order to adopt a reasonable strategy with minimum post-fire repair. In this paper, a fiber beam model for the simulation of the post-fire response of slender concrete-filled steel tubular (CFST) columns is presented. First, the model is validated against experimental results and subsequently it is employed to analyse the post-fire response of circular CFST columns. The variation of the residual strength with the load level for realistic fire resistance times is numerically studied. Actually, in a building, the columns support load even while a fire is being extinguished, so it is important to take into account this loading condition when predicting the post-fire behaviour. Therefore, in this research, the complete analysis comprises three stages: heating, cooling and post-fire under sustained load conditions. The model considers realistic features typical from the fire response of CFST columns, such as the existence of a gap conductance at the steel-concrete interface or the sliding and separation between the steel tube and the concrete.
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Güler, Soner, Fuat Korkut, Namik Yaltay, and Demet Yavuz. "Axial behaviour of concrete filled steel tube stub columns: a review." In 12th international conference on ‘Advances in Steel-Concrete Composite Structures’ - ASCCS 2018. Valencia: Universitat Politècnica València, 2018. http://dx.doi.org/10.4995/asccs2018.2018.7602.
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Concrete-filled steel tubular (CFST) columns are widely used in construction of high-rise buildings and peers of bridges to increase the lateral stiffness of the buildings, the axial load capacity, ductility, toughness, and resistance of corrosion of the columns. The CFST columns have much superior characteristics compared with traditionally reinforced concrete columns. The position of the concrete and steel tube in the cross-section of the CFST column is the most appropriate solution in terms of the strength and ductility. The steel tube, which is placed outside of the cross-section of the column, withstand the bending moment effectively. The concrete that is placed into the steel tube delay the local buckling of the steel tube and increase the axial load capacity of the column due to continually lateral confining. This paper presents a review on experimental results of the axial behavior of CFST columns performed by various researchers.
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Tao, Zhong, Utsab Katwal, Kamrul Hassan, and Wen-Da Wang. "Simplified numerical modelling of rectangular concrete-filled steel columns, beams and beam-columns." In 12th international conference on ‘Advances in Steel-Concrete Composite Structures’ - ASCCS 2018. Valencia: Universitat Politècnica València, 2018. http://dx.doi.org/10.4995/asccs2018.2018.6949.
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Because of its computational efficiency, simplified numerical modelling is the preferred method to simulate structural frames for routine design. As for concrete-filled steel tubular (CFST) columns, fibre beam element (FBE) modelling is often used in the simplified simulation. However, the accuracy of FBE modelling is greatly affected by the accuracy of the input material models, which should directly account for the interaction between the steel tube and core concrete. In this paper, simple yet accurate material models of steel and concrete are proposed for rectangular CFST columns by utilising a large amount of numerical data generated from detailed three-dimensional finite element modelling of stub columns. The material models are then incorporated into the simplified FBE simulation of rectangular CFST columns, beams and beam-columns. The accuracy of the simplified FBE simulation is verified by a wide range of experimental results on rectangular CFST stub columns, slender columns, beams and beam-columns.
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"An Experimental Investigation on Concrete Filled Steel Tube Columns Under Axial Compression." In Recent Advancements in Geotechnical Engineering. Materials Research Forum LLC, 2021. http://dx.doi.org/10.21741/9781644901618-9.
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Abstract. This paper presents an experimental investigation on the behaviour of concrete filled steel tube columns under axial compression. The steel columns were filled with self-compacting and self-curing concrete instead of normal conventional concrete. A test program consisting of square column, circular column and rectangular column was firstly conducted. The behaviour of three concrete filled steel tubular sections (CFSTs) under axial load is presented. The effect of steel tube dimensions, shapes and confinement of concrete are also examined. Measured column strengths are compared with the values predicted by Euro code 4 and American codes. Euro code 4, gives good estimation of self-compaction concrete. However, lower values as measured during the experiments were predicted by the American Concrete Institute (ACI) equation. Also, the effect of thickness of steel tubes, concrete cube strength and steel percentage is also studied. In addition to CFST column the steel tube also acts as confinement for concrete.
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Piquer Vicent, Ana, David Hernández-Figueirido, and Carmen Ibáñez Usach. "Concrete-filled round-ended steel tubular stub columns under concentric and eccentric loads." In 12th international conference on ‘Advances in Steel-Concrete Composite Structures’ - ASCCS 2018. Valencia: Universitat Politècnica València, 2018. http://dx.doi.org/10.4995/asccs2018.2018.7197.
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In the past, many works to study the mechanical behaviour of concrete filled steel tubular (CFST) stub columns have been conducted. Some of the applications of these composite columns oblige to meet higher requirements of ductility and load-bearing capacity. Traditionally, circular and rectangular tubes have been employed but recently new cross-sectional shapes of these composite columns are being designed and investigated with the aim of optimizing their mechanical behaviour. In this line, concrete-filled round-ended steel tubular columns (CFRT) have appeared as an alternative. However, the number of experimental programs to characterize their mechanical response is still scarce. In order to contribute to the test results database, in this paper an experimental study of 9 concrete-filled round-ended steel tubular stub columns is presented. All the specimens were designed with the same cross-sectional round-ended shape and have the same dimensions. In this program, both normal and high-strength concrete were employed as infill. During the tests, the columns were subjected to axial compression loads but under different eccentricities. The influence of eccentricity and concrete strength on the ultimate load bearing capacity of the concrete-filled round-ended steel tubular are discussed. Besides, the combined action of both components in this type of concrete-filled tubes as well as the effect of the concrete infill are studied.
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Lapuebla-Ferri, Andrés, Cesar Lacuesta, Manuel L. Romero, and José M. Adam. "A numerical model with varying passive confinement for circular and elliptical concrete-filled steel tubular columns." In 12th international conference on ‘Advances in Steel-Concrete Composite Structures’ - ASCCS 2018. Valencia: Universitat Politècnica València, 2018. http://dx.doi.org/10.4995/asccs2018.2018.7246.
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In this work, a non-linear 3D numerical model to study concrete-filled tubular (CFST) columns is presented. The numerical model is capable to consider the passive confinement that occurs in the concrete core of CFST columns, under which an increase in the strength and ductility of the element is expected. Passive confinement is governed by the volumetric deformation of the concrete core and by the increment of concrete strength, so it was necessary to define both aspects in the constitutive model. In the volumetric deformation, the elastic and plastic components were included, the latter by using the Drucker-Prager model. Different values for the angle of dilatancy were defined for normal and high strength concrete. The model was validated by using experimental tests performed on stub columns and eccentrically loaded columns. In addition, different section geometries were tested. According to the results, the model was able to describe the non-uniform confinement that appears in the concrete core of CFST columns.
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Wang, Fa-Cheng, Hua-Yang Zhao, and Lin-Hai Han. "Analytical behavior of concrete-filled aluminum tubular stub columns under axial compression." In 12th international conference on ‘Advances in Steel-Concrete Composite Structures’ - ASCCS 2018. Valencia: Universitat Politècnica València, 2018. http://dx.doi.org/10.4995/asccs2018.2018.7135.
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This paper presents numerical investigation of circular concrete-filled aluminum tubular (CFAT) stub columns under axial compression. The numerical models were developed using the finite element (FE) package ABAQUS. The parameters commonly employed in conventional CFST FE modeling have been discussed in this study. The nonlinearities of concrete and aluminum materials and the interaction between concrete and aluminum tube were considered. Numerical models were validated against collected experimental data. The ultimate loads, load-axial strain relationship and failure modes from numerical simulations were compared with those from experiments. The verified FE model was used to analyze structural behavior of full histories of the corresponding load-deformation N-ε response. Load-deformation N-ε curves for both concrete and aluminum tube were also presented. Upon on validation of the FE models, additional structural performance data over a wide range of diameter-to-thickness ratios, aluminum grades and concrete strengths were generated for parametric studies. The influences of diameter-to-thickness ratios, aluminum grades and concrete strengths on the ultimate strength were presented in this paper.
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Wencong, Li. "Axial Compression Behaviour of Concrete-Filled Double-Layer Steel Tubular Column." In IABSE Congress, Christchurch 2021: Resilient technologies for sustainable infrastructure. Zurich, Switzerland: International Association for Bridge and Structural Engineering (IABSE), 2021. http://dx.doi.org/10.2749/christchurch.2021.1214.
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<p>Nowadays, height of supertall buildings with height over 300 meters have been successively renewed in the world. To improve the global stability of the supertall building, mega-columns with excellent seismic, wind-resistance and axial compressive performance are recommended to be set in its perimeter. Concrete-filled double-layer steel tubular column (CFDLT column) transforming from the concrete-filled double-skin steel tubular column (CFDST column) by filling the hollow part of cross-section with concrete was proposed by the author. In this study, axial compression tests of CFDLT column, CFDST column and conventional concrete-filled steel tubular column (CFT column) specimens were carried out to investigate the axial compression behaviour of them. The experimental results showed that the CFDLT column specimen exhibits higher axial compressive strength and larger energy dissipation capacity than the CFDST column and the conventional CFT column specimens. It was found that the axial stiffness of CFDLT column degrades slower than that of the conventional CFT column right after the peak load. And, it is expected that the CFDLT column can be used as a mega-column in the tomorrow’s supertall buildings.</p>
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Tan, Qinghua, Leroy Gardner, Linhai Han, and Dianyi Song. "Analysis of concrete-filled stainless steel tubular columns under combined fire and loading." In 12th international conference on ‘Advances in Steel-Concrete Composite Structures’ - ASCCS 2018. Valencia: Universitat Politècnica València, 2018. http://dx.doi.org/10.4995/asccs2018.2018.7206.
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In fire scenarios, concrete-filled stainless steel tubular (CFSST) columns undergo initial loading at ambient temperature, loading during the heating phase as the fire develops, loading during the cooling phase as the fire dies out and continual loading after the fire. CFSST columns may fail some points during this process under combined fire and loading. In this paper, the failure modes and corresponding working mechanism of CFSST columns subjected to an entire loading and fire history are investigated. Sequentially coupled thermal-stress analyses in ABAQUS are employed to establish the temperature field and structural response of the CFSST column. To improve the precision of the finite element (FE) model, the influence of moisture on the thermal conductivity and specific heat of concrete during both the heating and cooling phases is considered using subroutines. Existing fire and post-fire test data of CFSST columns are used to validate the FE models. Comparisons between predicted and test results confirm that the accuracy of the FE models is acceptable; the FE models are then extended to simulate a typical CFSST column subjected to the entire loading and fire history. The behaviour of the CFSST column is explained by analysis of the temperature distribution, load versus axial deformation curves and failure response.
Reports on the topic "Concrete-filled steel tubular (CFST) columns"
1
WANG, Liping, Xing-Xing CAO, Fa-Xing DING, and Yi SUN. COMPRESSION TESTS OF CONCRETE-FILLED DOUBLE CIRCULAR STEEL TUBULAR STUB COLUMNS. The Hong Kong Institute of Steel Construction, December 2018. http://dx.doi.org/10.18057/icass2018.p.083.
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Pedro F., Rodrigues, Vellasco Pedro C. G. da S., Lima Luciano R. O. de, Silva André T. da, Rodrigues Monique C., and Sarmanho Arlene M. C. EXPERIMENTAL EVALUATION OF COMPOSITE TUBULAR COLUMNS CFDST (STAINLESS STEEL–CONCRETE–CARBON STEEL). The Hong Kong Institute of Steel Construction, December 2019. http://dx.doi.org/10.18057/icass2018.p.025.
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Li, Wei, and Bing Chen. PUSH-OUT TESTS ON CIRCULAR CONCRETE-FILLED DOUBLE-SKIN STEEL TUBULAR COLUMNS. The Hong Kong Institute of Steel Construction, December 2018. http://dx.doi.org/10.18057/icass2018.p.172.
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QI, H., Y. DU, B. WANG, and R. Liew. STUDY ON TEMPERATURE DISTRIBUTION OF HIGH STRENGTH CONCRETE FILLED STEEL TUBULAR COLUMNS DUE TO FIRE. The Hong Kong Institute of Steel Construction, December 2018. http://dx.doi.org/10.18057/icass2018.p.165.
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Yiran, Wu, Meng Lingye, and Shi Yongjiu. INVESTIGATIONS OF JOINTS STRENGTH PERFORMANCE WITH T-SECTION CONCRETE FILLED STEEL TUBULAR COLUMNS AND I-SECTION STEEL BEAMS. The Hong Kong Institute of Steel Construction, December 2018. http://dx.doi.org/10.18057/icass2018.p.027.
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CALCULATION METHOD OF ULTIMATE LOAD BEARING CAPACITY OF CONCRETE FILLED STEEL TUBULAR LATTICE COLUMNS. The Hong Kong Institute of Steel Construction, August 2022. http://dx.doi.org/10.18057/icass2020.p.095.
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To investigate the influence of eccentricity ratio and slenderness ratio on the mechanical properties of eccentric compressed concrete filled steel tubular (CFST) lattice column, the ultimate bearing capacity tests of 20 K shape arrangement lacing strip of four-tube CFST columns were conducted. Based on the stress-strain relationship of CFST and the influence of shear deformation, the equilibrium equation of the mid-section is established and a numerical method for the ultimate bearing capacity of CFST lattice column is proposed. The slenderness reduction coefficient calculation model and equivalent slenderness ratio formula of CFST lattice column are established. Combined with the numerical results and the slenderness ratio reduction coefficient calculation model, the formula of slenderness ratio reduction coefficient is put forward. The comparison between theoretical analysis and experimental results shows that the calculation method of elastic-plastic ultimate bearing capacity of CFST lattice column proposed in this paper is quite accurate. The research outcomes can provide a reference for the application of CFST lattice column and revision of current specifications.
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AXIAL COMPRESSION BEHAVIOR OF SQUARE THIN-WALLED CFST COLUMN TO RC BEAM JOINTS. The Hong Kong Institute of Steel Construction, August 2022. http://dx.doi.org/10.18057/icass2020.p.288.
Full textAbstract:
To investigate the influence of eccentricity ratio and slenderness ratio on the mechanical properties of eccentric compressed concrete filled steel tubular (CFST) lattice column, the ultimate bearing capacity tests of 20 K shape arrangement lacing strip of four-tube CFST columns were conducted. Based on the stress-strain relationship of CFST and the influence of shear deformation, the equilibrium equation of the mid-section is established and a numerical method for the ultimate bearing capacity of CFST lattice column is proposed. The slenderness reduction coefficient calculation model and equivalent slenderness ratio formula of CFST lattice column are established. Combined with the numerical results and the slenderness ratio reduction coefficient calculation model, the formula of slenderness ratio reduction coefficient is put forward. The comparison between theoretical analysis and experimental results shows that the calculation method of elastic-plastic ultimate bearing capacity of CFST lattice column proposed in this paper is quite accurate. The research outcomes can provide a reference for the application of CFST lattice column and revision of current specifications.
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PARAMETRIC STUDIES ON THE MOMENT RESISTANT BEAMCOLUMN CONNECTION BEHAVIOR OF CONCRETE FILLED DOUBLE STEEL TUBULAR COLUMNS AND I STEEL BEAMS. The Hong Kong Institute of Steel Construction, August 2022. http://dx.doi.org/10.18057/icass2020.p.284.
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The configuration of Concrete filled double steel tubular cross-section (CFDST) has the potential to overcome the beam-column connection difficulties found in steel tubular cross-sections. Since experimental parametric studies are expensive, numerical methods are adopted in this study to understand the behavior of beam-CFDST column connection under monotonic and cyclic loading conditions. The connection type is observed to be as semi-rigid as per EN1993-1-8. Parametric study includes design parameters like, concrete infill strength, yield strength of inner steel tube and outer steel tube, hollowness ratio, width to thickness ratio of inner steel tube and outer steel tube, end plate thickness and provision of stiffeners for end plate. Thickening the inner steel tube locally at the bolt location and providing stiffener plate or bracket at the compression zone of the extended end plate improves the rotational capacity of the connection as high as 0.06 rad for full plastic moment capacity of the beam. Recommendations are given for proportioning the connection components like end plates, bolts, inner steel tube and stiffeners for an optimal semi-rigid connection design.
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AXIAL COMPRESSIVE BEHAVIOR OF SELF-STRESSING STEEL SLAG AGGREGATE CONCRETE FILLED STEEL TUBULAR COLUMNS WITH BOND-SLIP DAMAGE. The Hong Kong Institute of Steel Construction, March 2020. http://dx.doi.org/10.18057/ijasc.2020.16.1.2.
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NUMERICAL INVESTIGATION ON CYCLIC BEHAVIOR OF RING-BEAM CONNECTION TO GANGUE CONCRETE FILLED STEEL TUBULAR COLUMNS. The Hong Kong Institute of Steel Construction, December 2021. http://dx.doi.org/10.18057/ijasc.2021.17.4.7.
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As a promising composite structure, gangue concrete filled steel tubular (GCFST) column exhibites favarable characteristics including high strength and economic efficiency. This paper conducted numerical investiagations on structural behavior of a ring-beam connection to GCFST column with concrete beam under cyclic loading. Furthermore, finite element models of column-beam connections were developed using ABAQUS and validated against full-scale experimental tests to identify accuracy of selected modeling approaches. Using these validated models, stress distribution of each component was examined to study the force-transferring mechanism among the components and failure modes of the ring-beam connection. Research study indicated that the ring-beam connection showed a reasonable force-transferring mechanism under cyclic loading and the remarkable earthquake-resistant performance with high capacity and acceptable ductility. Finally, parametric studies were performed to assess the influences of beam-to-column stiffness ratio,steel ratio, axial load level, and concrete compressive strength on connection cyclic behaviors. Parametric studies provided some suggestions and references for the application of the ring-beam connection in various engineering projects.