• Journal of Korean Society of Steel Construction
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• v.17 no.4 s.77
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• pp.431-438
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• 2005

A steel-concrete composite column is a recently developed composite system in which the two opposite flanges of the H-shape section are connected by welded links, and the vacant space enclosed by the flanges, web, and links is filled with concrete. Previous experiments on the SC composite column were performed to evaluate its compression and bending and shear strengths, respectively, and they showed fairly good results. In addition to thesestudies, it may be necessary to evaluate the flexural-axial capacity of an SC composite column, because itscolumn members are generally subjected to axial force and bending moment at the same time. In this study, the bending strength of an SC composite column subjected to axial compression force was investigated experimentally. The results of the study showed that the AISC-LRFD provisions representedexcessively low values compared with those of the ACI, Eurocode-4, and Japan Code provisions. The Eurocode-4 provisions represented reasonable evaluations of the strength of the SC composite column composed of a non-compact section.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2016.10a
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• pp.71-72
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• 2016

Most of studies on PC method aim at the structural analysis and development of PC members, and studies on the construction management aspect are insufficient. Therefore, this study tries to investigate 'hallow PC column composite method(HPC composite method)' from the viewpoint of construction management and analyze the construction cost of the composite method. On the assumption that each comparative method was applied to the zone, the difference in construction cost between the two methods was analyzed. As a result, HPC composite method increased the initial investment cost because of its factor technology, but reduced transport cost, lifting cost, and installation cost through lightweight columns. This study analyzed only the difference in construction cost of HPC composite method so that it has the limitation in evaluating its economy. Therefore, to evaluate the economy of HPC composite method, it is considered to research more the construction cost of HPC composite method.

• Steel and Composite Structures
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• v.8 no.5
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• pp.423-438
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• 2008

This paper reports an experimental investigation of the behaviour of concrete-encased composite columns subjected to short-term axial load and biaxial bending. In the study, six square and four L-shaped cross section of both short and slender composite column specimens were constructed and tested to examine the load-deflection behaviour and to obtain load carrying capacities. The main variables in the tests were considered as eccentricity of applied axial load, concrete compressive strength, cross section, and slenderness effect. A theoretical procedure considering the nonlinear behaviour of the materials is proposed for determination of the behaviour of eccentrically loaded short and slender composite columns. Two approaches are taken into account to describe the flexural rigidity (EI) used in the analysis of slender composite columns. Observed failure mode and experimental and theoretical load-deflection behaviour of the specimens are presented in the paper. The composite column specimens and also some composite columns available in the literature have been analysed and found to be in good agreement with the test results.

• Steel and Composite Structures
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• v.20 no.6
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• pp.1259-1274
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• 2016

A precast composite column system has been developed in this study by utilizing multi interlocking spiral steel into a centrifugally-formed hollow-core precast (CHPC) column. The proposed hybrid column system can have enhanced performances in the composite interaction behavior between the hollowed precast column and cast-in-place (CIP) core-filled concrete, the lap splice performance of bundled bars, and the confining effect of concrete. In the experimental program, reversed cyclic loading tests were conducted on a conventional reinforced concrete (RC) column fabricated monolithically, two CHPC columns filled with CIP concrete, and two steel-reinforced concrete (SRC) columns. It was confirmed that the interlocking spirals was very effective to enhance the structural performance of the CHPC column, and all the hollow-core precast column specimens tested in this study showed good seismic performances comparable to the monolithic control specimen.

• Structural Engineering and Mechanics
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• v.24 no.3
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• pp.291-306
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• 2006

In order to improve the constructability and meanwhile ensure excellent seismic behavior, several innovative composite connection details were conceived and studied by the authors. This paper reports experimental results and observations on seismic behavior of steel beam bolted to reinforced concrete column connections (bolted RCS or BRCS). The proposed composite connection details involve post tensioning the end plates of the steel beams to the reinforced concrete or precast concrete columns using high-strength steel rods. A rational design procedure was proposed to assure a ductile behavior of the composite structure. Strut-and-tie model analysis indicates that a bolted composite connection has a favorable stress transfer mechanism. The excellent capacity and behavior were then validated through five full-scale beam to column connection model tests.

• Steel and Composite Structures
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• v.20 no.3
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• pp.599-621
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• 2016

In order to study the working mechanism of rectangular steel-concrete composite columns subjected to compression-bending load and further determine the seismic performance index, a bottom strengthened rectangular steel reinforced concrete (SRC) column with concealed steel plates and a bottom strengthened rectangular concrete filled steel tube (CFST) columns were proposed. Six column models with different configurations were tested under horizontal low cyclic loading. Based on the experiments, the load-bearing capacity, stiffness and degradation process, ductility, hysteretic energy dissipation capacity, and failure characteristics of the models were analyzed. The load-bearing capacity calculation formulas for a normal section and an oblique section of bottom strengthened rectangular steel-concrete composite columns were pesented and a finite element (FE) numerical simulation of the classical specimens was performed. The study shows that the load-bearing capacity, ductility, and seismic energy dissipation capacity of the bottom strengthened rectangular steel-concrete composite columns are significantly improved compared to the conventional rectangular steel-concrete composite columns and the results obtained from the calculation and the FE numerical simulation are in good agreement with those from the experiments. The rectangular steel-concrete composite column with bottom strengthened shows better seismic behavior and higher energy dissipation capacity under suitable constructional requirements and it can be applied to the structure design of high-rise buildings.

• Steel and Composite Structures
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• v.33 no.1
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• pp.143-162
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• 2019

A number of desirable characteristics concerning excellent durability, aesthetics, recyclability, high ductility and fire resistance have made stainless steel a preferred option in engineering practice. However, the relatively high initial cost has greatly restricted the application of stainless steel as a major structural material in general construction. This drawback can be partially overcome by introducing composite stainless steel-concrete structures, which provides a cost-efficient and sustainable solution for future stainless steel construction. This paper presents a preliminary numerical study on stainless steel-concrete composite beam-to-column joints with bolted flush endplates. In order to ensure a consistent corrosion resistance within the whole structural system, all structural steel components were designed with austenitic stainless steel, including beams, columns, endplates, bolts, reinforcing bars and shear connectors. A finite element model was developed using ABAQUS software for composite beam-to-column joints under monotonic and symmetric hogging moments, while validation was performed based on independent test results. A parametric study was subsequently conducted to investigate the effects of several critical factors on the behaviour of composite stainless steel joints. Finally, comparisons were made between the numerical results and the predictions by current design codes regarding the plastic moment capacity and the rotational stiffness of the joints. It was concluded that the present codes of practice generally overestimate the rotational stiffness and underestimate the plastic moment resistance of stainless steel-concrete composite joints.

• Journal of Korean Society of Steel Construction
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• v.26 no.5
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• pp.473-483
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• 2014

According to the Korean Building Code (KBC), the validity of the application of 800MPa grade steel(HSA800) to composite column should be verified by experimental or analytical method. Thus, stub column tests for encased and filled composite members with HSA800 steel were conducted, and axial strength and the validity of design compressive strength equations in KBC were evaluated. The test results show that the equation of the compressive strength of encased composite column member in KBC should be modified in order to use HSA800 steel without any reduction of specified minimum yield strength. For this purpose, it is suggested that the interval of hoop should be narrowed and the effective concrete area should be used. The equation of the compressive strength of filled composite column member in KBC is applicable to filled composite column with HSA800 steel without any modification.

• Journal of Korean Society of Steel Construction
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• v.19 no.4
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• pp.425-434
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• 2007

The SC (steel-concrete) composite column was developed to take advantage of the relative economy of using concrete as opposed to steel in carrying large compressive forces. As the SC composite column is pre-fabricated, its use can minimize laborand can speed up the erection of a steel building. In this study, an experiment was conducted to analyze the influence of several parameters, such as the load ratio, the concrete ratio of an area, and its performance with or without fire protection, on the performance of the SC composite column. This paper proposes that the calculation of the strength reduction ratios of columns be done by increasing the temperature. Theoretical equations were used to evaluate the effectiveness of the fire resistance of the SC composite column, and the results of the test and analysis were compared. The fire resistance of the SC composite column was increased by decreasing its load ratio, but the concrete ratio of an area has minimal influence on the fire resistance of the SC composite column.

• Steel and Composite Structures
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• v.28 no.4
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• pp.471-482
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• 2018

The composite reinforced concrete and steel (RCS) structural systems have larger structural lateral stiffness, higher inherent structural damping, and faster construction speed than either traditional reinforcement concrete or steel structures. In this paper, four RCS subassemblies with or without the RC slab designed following a strong column-weak beam philosophy were constructed and tested under reversed-cyclic loading. Parameters including the width of slab and composite effect of the RC slab and beam were explored. The test results showed that all specimens performed in a ductile manner with plastic hinges formed in the beam ends near the column faces. The seismic responses of composite connections are influenced significantly by different width of slabs. Compared with that of the steel beam without the RC slab, it was found that the load carrying capacity of composite connections with the RC slab increased by 30% on average, and strength degradation, energy dissipation also had better performance, while the ductility of that were almost the same. Furthermore, the contribution of connection deformation to the overall specimen displacement was analyzed and compared. It decreased approximately 10% due to the coupling effect in the columns and beams with the RC slab. Based on the test result, some suggestions are presented for the design of composite RCS joints.