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

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.28 no.3A
• /
• pp.383-390
• /
• 2008

A Precast Prefabricated Bridge Column using steel tube and prestressing bar was proposed for the application of precast method on substructure. A column specimen designed by the proposed bridge column system was made and performed a quasi-static test. The failure mode appeared to be a flexural failure and there is no damage on column segment connection. And it is good use of the self-centering ability by prestressing force. Test results showed that a column specimen satisfy the earthquake specification, and the structural stability was verified. Nonlinear finite element analysis was performed and compared with the test results. Force-displacement relation and location of crack from the analysis results were compared with the test results and it agreed well. The quantitative analysis was also performed by a parametric study using this modeling technique.

• Journal of Korean Society of Steel Construction
• /
• v.19 no.6
• /
• pp.655-661
• /
• 2007

A new steel connection method using wedges known as Self-Locking Connector has been developed. In this study, experimental investigation was conducted to verify the seismic performance of steel beam-to-column joints with Self-Locking Connectors. Cyclic-loading tests were performed on two beam-to-column joints with Self-Locking Connectors. The two beam-to-column joint specimens were of the cantilever-type and had the same details. Test results showed that beam-to-column joints with Self-Locking Connectors were able to developa total rotation capacity of 0.06 radian, which is greater than the 0.04 radian required for Special Moment Frames. Moreover, their energy absorption capacity was much greater than that of conventional joints.

• Journal of Korean Society of Steel Construction
• /
• v.9 no.2 s.31
• /
• pp.277-285
• /
• 1997

To investigate the shear strength and hysteretic behavior of SRC column to H steel beam joints, seven cruciform specimens were fabricated and tested. The test specimens showed stable hysteresis behavior with a little pinching. The strength decreased with increase in deflection after the speciemens reached at the maximum strength. The shear strength of panel zones increased with increased in the concrete amount of SRC column sections. The shear strength may conservatively be estimated by the sum of shear yielding strength of steel column web, plastic bending strength of steel column flange and ultimate shear strength of concrete in the panel zone.

• Journal of Korean Society of Steel Construction
• /
• v.22 no.2
• /
• pp.185-195
• /
• 2010

This paper presents the experiment results for a CFT column confined by carbon fiber sheets(CFSs) under an axial load. Nine specimens were constructed and axial compression tests were conducted. The main experiment parameters were diameter-thickness ratio(D/t), reinforcing CFSa, and the attachment of a cushion gap between surface of steel tube and CFSs. The load-displacement curves of the specimens were obtained from the compression tests. Finally, it was concluded that the CFT column with a gap had grater ductility capacity improvement that the CFT column confined by CFSs.

• Journal of the Korea Concrete Institute
• /
• v.24 no.3
• /
• pp.241-248
• /
• 2012

This paper presents a reinforced concrete composite column method in order to improve seismic performance of reinforced concrete column specimens by selectively applying steel fiber-reinforced mortars at the column plastic hinge region. In order to evaluate seismic improvement of the newly developed column method, a series of cyclic load test of column specimens under a constant axial load was investigated by manufacturing three specimens, two reinforced concrete composite columns by applying steel fiber-reinforced mortars at the column plastic hinge region and one conventional reinforced concrete column. Both concrete and steel fiber-reinforced mortar was cast-in placed type. From cyclic load test, it was found that the newly developed steel fiber-reinforced columns showed improved seismic performances than conventional reinforced concrete column in controlling bending and shear cracks as well as improving seismic lateral load-carrying capacities and lateral deformation capacities.

• Journal of the Korea Concrete Institute
• /
• v.26 no.4
• /
• pp.545-553
• /
• 2014

This study suggested an integrated classification method for generalized characteristics of PC beam-column connection according to connection details. Quantifying the failure mode of PC-beam column connection and characteristics of corresponding details, this study suggested to use deformation contribution of each element of beam-column assemblage. According to the expected failure mode of beam-column connection assemblage, PC beam-column connection can be classified into 'equivalent monolithic system' and 'jointed system'. In this study, four test specimens were tested for verification of detailed classification method of PC beam-column connections. Test was carried out with typical beam-column connection test method. Load was applied at the top of test specimen and end of beams were restrained by hinge. In order to verify the deformation contribution of each test specimen, 34-LVDTs were mounted on test specimen. According to test results, deformation contribution of each test specimen have different characteristics. Deformation characteristics of joint and other components which are quantified by test results, equivalent monolithic system can be classified into two categories. Strong connection have extremely small deformation contribution of joint and much larger deformation contribution was shown in flexural behavior of beam. The other type of beam-column connection is ductile connection which allows the larger deformation in joint area compared with strong connection.

• Journal of Korean Society of Steel Construction
• /
• v.17 no.4 s.77
• /
• pp.459-467
• /
• 2005

This study focuses on the development of a new method of H-shaped beam-to-square column connection with an outer diaphragm and a field welding. The specific type of beam-to-column connection with an external stiffener, using field welding, is proposed. The structural behavior of this connection was examined experimentally. Two loading type tests were conducted under the experimental parameters given as details. First described was the symmetrical loading test, which supported both ends or a beam simply and applied a load from the column to the pend (What does this mean?) to investigate a fundamental characteristic of this connection. Further described was the anti-symmetrical loading test, which carried out simple support of the column'stop end and the column base, and applied a load from both ends of a beam to investigate the structural performance of this connection. From the results, it is clear that the external- stiffener-type connection proposed in this paper is the reliable connection method.

• Proceedings of the Korean Institute Of Construction Engineering and Management
• /
• autumn
• /
• pp.222-227
• /
• 2001

Full scale construction tests of CFT(concrete filled steel tube) column to solve construction problem and to confirm quality were performed in apartment site. To improve construction efficiency, the tests has been accomplished two stages after the tests for material mixing design had been completed. In the first stage, the experimental variables were the placing methods, existence of guiding pipe, placing velocity and drop height and the height of specimen were $3.6{\cal}m$. In the second stage, Filling steel tube of 9.6m height with concrete was performed by two ways, that is, the pump-up method and the dropping method. The filled condition of the concrete and concrete strength distribution according to the column height were checked and the quality of the CFT column was confirmed.

• Journal of Korean Society of Steel Construction
• /
• v.21 no.5
• /
• pp.515-526
• /
• 2009

There are three main production processes in the manufacture of concrete-filled square steel columns. The first process is known as the 'box-type process' or 'four-seam method,' wherein four beams are welded together at the seams. The second is the 'cold-forming process' or 'two-seam method,' wherein the seams of two channel beams are welded together. The third is the 'pressing process' or 'one-seam method,' wherein a circular column is pressed until it becomes a square column. In calculating the production cost for the making of a steel tube, it is very important to consider the welding process to be used and the desiredthickness of the steel tube, such as a square column that was developed under a new method, formed through the four-seam flare welding method at the center of the steel column width, following the L-shape formation. Certain tests were suggested in this study to evaluate the welding amount of concrete-filled square steel columns. With the parameters of the production method of a square steel column, the thickness of the steel square columns, and the welding amount, six specimens were produced. A structural test and finite-element analysis were conducted to assess the behavior of the steel column according to the water pressure inside the steel columns.