• Title, Summary, Keyword: concrete filled tubular column

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Tests on fiber reinforced concrete filled steel tubular columns

  • Gopal, S. Ramana;Devadas Manoharan, P.
    • Steel and Composite Structures
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    • v.4 no.1
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    • pp.37-48
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    • 2004
  • This paper deals with the strength and deformation of both short and slender concrete filled steel tubular columns under the combined actions of axial compression and bending moment. Sixteen specimens were tested to investigate the effect of fiber reinforced concrete on the ultimate strength and behavior of the composite column. The primary test parameters were load eccentricity and column slenderness. Companion tests were also undertaken on eight numbers of similar empty steel tubes to highlight the synergistic effects of composite column. The test results demonstrate the influence of fiber reinforced concrete on the strength and behavior of concrete filled steel tubular columns.

An experimental study on th reinforced concrete filled tubular column to steel H-beam connections with outer diaphram by simplified connection type (철근콘크리트충전 강관기둥과 외부다이아프램을 보강한 H형강 보 접합부의 단순모형에 의한 실험연구)

  • 김인덕;최병극;박성무
    • Proceedings of the Korea Concrete Institute Conference
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    • pp.587-596
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    • 1997
  • This study is concerning the structural behavior of reinforced concrete filled tubular column to steel H-beam connections with outer diaphram by simplified connection type. The important parameters of this study are the cross-section shape of tubular column and the spacing of hoop (60mm, 30mm, 20mm) and the concrete filled or not. The experimental results are summarized for the strength and displacement of each specimen.

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Axial compression performance of basalt-fiber-reinforced recycled-concrete-filled square steel tubular stub column

  • Zhang, Xianggang;Gao, Xiang;Wang, Xingguo;Meng, Ercong;Wang, Fang
    • Advances in concrete construction
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    • v.10 no.6
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    • pp.559-571
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    • 2020
  • This study aimed to inspect the axial compression mechanical performance of basalt-fiber-reinforced recycled - concrete (BFRRC)-filled square steel tubular stub column. The replacement ratio of recycled coarse aggregate (RCA) and the basalt fiber (BF) dosage were used as variation parameters, and the axial compression performance tests of 15 BFRRC-filled square steel tubular stub column specimens were conducted. The failure mode and the load-displacement/strain curve of the specimen were measured. The working process of the BFRRC-filled square steel tubular stub column was divided into three stages, namely, elastic-elastoplasticity, sudden drawdown, and plasticity. The influence of the design parameters on the peak bearing capacity, energy dissipation performance, and other axial compression performance indexes was discussed. A mathematical model of segmental stiffness degradation was proposed on the basis of the degradation law of combined secant-stiffness under axial compression. The full-process curve equation of axial compressive stress-strain was proposed by introducing the influencing factors, including the RCA replacement ratio and the BF dosage, and the calculated curve agreed well with the test-measured curve.

Strength of Concrete-Filled Rectangular Steel Tubular Columns (콘크리트 충전 각형강관 기둥의 내력 평가)

  • Yoo, Yeong Chan;Moon, Tae Sup
    • Journal of Korean Society of Steel Construction
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    • v.11 no.1
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    • pp.89-98
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    • 1999
  • The objective of this paper is to investigate the structural behavior of concrete filled steel tubular columns subjected to eccentric load. With experiment and analytical study, the buckling behavior of columns is investigated and compared with each other to the view of main parameters. Appling foreign standards in the experimental results, we suggested new strength formula of concrete-filled steel tubular columns. The parameters are slenderness, eccentric ratio, and concrete filled or not. The experiment are carried out by simple loading.

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Study on strength of reinforced concrete filled circular steel tubular columns

  • Hua, Wei;Wang, Hai-Jun;Hasegawa, Akira;Shioi, Yukitake;Iwasaki, Shoji;Miyamoto, Yutaka
    • Structural Engineering and Mechanics
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    • v.19 no.6
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    • pp.653-677
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    • 2005
  • Concrete filled steel tubular columns (CFT) are widely used in civil engineering works, especially in large scale of works because of high strength, deformation, toughness and so on. On the other hand, as a kind of strengthening measure for seriously damaged reinforced concrete piers of viaduct in Hansin-Awaji earthquake of Japan in 1995, reinforced concrete piers were wrapped with steel plate. Then, a new kind of structure appeared, that is, reinforced concrete filled steel tubular column (RCFT). In this paper, compression test and bending-shearing test on RCFT are carried out. The main parameters of experiments are (1) strength of concrete, (2) steel tube with or without rib, (3) width-thickness ratio and (4) arrangement of reinforcing bars. According to the experimental results, the effect of parameters on mechanical characteristics of RCFT is analyzed clearly. At the same time, strength evaluation formula for RCFT column is proposed and tested by experimental results and existed recommendations (AIJ 1997). The strength calculated by the proposal formula is in good agreement with test result. As a result, the proposed evaluation formula can evaluate the strength of RCFT column properly.

Experimental Study on Compressive Strength of Centrally Loaded Concrete Filled Square Tubular Steel Columns (중심축압(中心軸壓)을 받는 콘크리트충전(充塡) 각형강관(角形鋼管)기둥의 내력(耐力)에 관한 실험적(實驗的) 연구(硏究))

  • Kim, Jong Sung;Oh, Yun Tae;Kwon, Young Hwan
    • Journal of Korean Society of Steel Construction
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    • v.8 no.4
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    • pp.59-76
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    • 1996
  • Concrete filled steel tube column has a large load carrying capacity through its steel and concrete interaction which makes it useful in construction. However, it has not been used often in a practical construction field. This is partly due to the non-destructive inspection method for concrete filling which has yet to be established. Furthermore, there are the lack of test data and a practical method in evaluating the ultimate load carrying capacity of concrete filled steel tube column. This paper will attempt to predict the ultimate strength of short concrete filled square tubular steel columns through conducting several tests. To accumulate the new test data on concrete filled steel tube columns, a total of 42 specimens of steel tubular columns were monotonically tested under concentric axial force, having the slenderness ratio(${\lambda}=10,\;15,\;20$), width-thickness ratio(d/t=25.0, 33.3) and concrete strengths($F_{c}=210,\;240,\;270kg/cm^{2}$). The hollow sections and concrete filled steel columns were compared to check the lateral confinded effects by steel tube. Through these test results, we propose a coefficient k=3.64 for the strength evaluation formula(10) of concrte filled tubular steel short columns.

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Fire resistance of high strength concrete filled steel tubular columns under combined temperature and loading

  • Tang, Chao-Wei
    • Steel and Composite Structures
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    • v.27 no.2
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    • pp.243-253
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    • 2018
  • In recent years, concrete-filled box or tubular columns have been commonly used in high-rise buildings. However, a number of fire test results show that there are significant differences between high strength concrete (HSC) and normal strength concrete (NSC) after being subjected to high temperatures. Therefore, this paper presents an investigation on the fire resistance of HSC filled steel tubular columns (CFTCs) under combined temperature and loading. Two groups of full-size specimens were fabricated to consider the effect of type of concrete infilling (plain and reinforced) and the load level on the fire resistance of CFTCs. Prior to fire test, a constant compressive load (i.e., load level for fire design) was applied to the column specimens. Thermal load was then applied on the column specimens in form of ISO 834 standard fire curve in a large-scale laboratory furnace until the set experiment termination condition was reached. The results demonstrate that the higher the axial load level, the worse the fire resistance. Moreover, in the bar-reinforced concrete-filled steel tubular columns, the presence of rebars not only decreased the spread of cracks and the sudden loss of strength, but also contributed to the load-carrying capacity of the concrete core.

A Experimental study about an effect of shear-connector at a bond stress in concrete filled rectangular tubular column (콘크리트 충전 각형 강관기둥의 부착응력에 있어 shear-connector의 영향에 관한 실험적 연구)

  • 박성무;김성수;김원호;이형석;이경섭;송준근
    • Proceedings of the Korea Concrete Institute Conference
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    • pp.561-566
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    • 2001
  • Load at steel beam column joints transfered by beam depend on bond strength between concrete and steel tube. But it is different to transmit a load efficiently in the established concrete filled steel tubular column. Therefore, shear-connector is demanded for transfering loads efficiently. An ascent of bond stress and a transmission of load after debonding are expected by a reinforcement of shear-connector

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An Experimental Study on a Bond Stress in Concrete Filled Circular Steel Tubular Column Strengthened by the Stiffener (스티프너로 보강한 콘크리트 충전 원형 강관기둥의 부착응력에 관한 실험적 연구)

  • Park, Sung-Moo;Kim, Sung-Su;Kim, Won-Ho;Lee, Hyung-Seok
    • Journal of Korean Association for Spatial Structures
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    • v.2 no.2
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    • pp.51-58
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    • 2002
  • This paper is presented an experimental studies on bond stress between steel and concrete in concrete filled steel tubes. In the actual building frames, vertical dead and live loads on beams are usually transferred to columns by beam-to-column connections. In case when concrete filled steel tubes are used as columns of an actual building frame which has a simple connection, shear forces in the beam ends are not directly transferred to the concrete core but directly to the steel tube. Provided that the bond effect between steel tube and concrete core should not be expected, none of the end shear in the beams would be transferred to the concrete core but only to the steel tube. Therefore, it is important to investigate the bond strength between steel tube and concrete core in the absence of shear connectors.

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An Experimental Study on the Compression Behavior of the Circular and Square Tubular Steel Pipe filled with Concrete (콘크리트 충전 원형 및 각형 합성 강관 기둥의 압축 거동에 관한 실험적 연구)

  • Park, Kang-Geun
    • Journal of Korean Association for Spatial Structures
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    • v.6 no.1
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    • pp.55-63
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    • 2006
  • Concrete-filled steel columns consist of circular, square or rectangular hollow sections filled concrete. Much research has studied for the behavior of concrete-filled steel structures. The advantages from structural point of view are the triaxial confinement of the concrete within the section, and the fire resistance of the column which largely depends on the residual capacity of the concrete core. The axial capacity of a concrete-filled rectangular or circular section is enhanced by the confining effect of the steel section on the concrete which depends in the magnitude on the shape of the section and the length of the column. Buckling tends to reduce the benefit of confinement on the squash load as the column slenderness increases. In circular sections it is possible to develop the cylinder strength of the concrete. When compare with reinforced concrete columns, the concrete-filled composite column possesses much better strength and ductility in shear and generally in flexure also. Many researches are being conducted about concrete filled steel column to get these advantages in building design. In this paper it is provided to the basic experimental study of compression behavior of the circular and rectangular tubular steel pipe filled with concrete.

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