• 제목/요약/키워드: prestressed beam

검색결과 278건 처리시간 0.019초

Experiment research on seismic performance of prestressed steel reinforced high performance concrete beams

  • Xue, Weichen;Yang, Feng;Li, Liang
    • Steel and Composite Structures
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    • 제9권2호
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    • pp.159-172
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    • 2009
  • Two prestressed steel reinforced high performance concrete (SRC) beams, a nonprestressed SRC beam and a counterpart prestressed concrete beam were tested under low reversed cyclic loading to evaluate seismic performance of prestressed SRC beams. The failure modes, deformation restoring capacity, ductility and energy dissipation capacity of the prestressed SRC beams were discussed. Results showed that due to the effect of plastic deformations of steel beams encased in concrete, the three SRC beams exhibited residual deformation ratios ranging between 0.64 and 0.79, which were apparently higher than that of the prestressed concrete beam (0.33). The ductility coefficients of the prestressed SRC beams and the prestressed concrete beam ranged between 4.65 and 4.87, obviously lower than that of nonprestressed SRC beam (9.09), which indicated the steel beams influenced the ductility little while prestressing resulted in an apparent reduction in ductility. The amount of energy dissipated by the prestressed SRC beams was less than that dissipated by the nonprestressed SRC beam but much more than that dissipated by the prestressed concrete beam.

연속 프리스트레스트 콘크리트 빔교의 내하력 평가 기법에 관한 연구 (A Study on the Load Carrying Capacity Assessment Method of the Prestressed Concrete Beam Bridges)

  • 채원규
    • 한국안전학회지
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    • 제13권3호
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    • pp.126-134
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    • 1998
  • In this paper, the field test by truck load and the structural analysis were performed on a prestressed concrete beam bridge to investigate the load carrying capacity of the prestressed concrete beam bridges. From the results of the field test and the structural analysis, CAF (composite action factor), TIF(transformed impact factor), and $P_n$(load carrying capacity) of the prestressed concrete beam bridges were studied, and the load carrying capacity assessment of the prestressed concrete beam bridges were carried out using these factors.

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고성능 강섬유보강 콘크리트가 적용된 반복하중을 받는 이중 프리스트레스 콘크리트 보의 휨 거동 (Flexural Behavior of Dual Prestress Concrete Beams Using High Performance Steel Fiber Reinforced Concrete Subjected to Cyclic Loading)

  • 박대효;윤성환
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 2004년도 추계 학술발표회 제16권2호
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    • pp.61-64
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    • 2004
  • This study presents results from an experimental work for two normal prestressed concrete beams and three dual prestressed concrete beams. The dual prestressed concrete beams made with normal concrete in compression zone and high performance steel fiber reinforced concrete in partial depth of tension zone. Through cyclic loading test under low frequency, structural behavior and resistance to dynamic loading for dual prestressed concrete beams are investigated. Considerable increase of crack and yield load capacity of Dual prestressed concrete beam is shown compared with normal prestressed concrete beam. In addition, re-loading and un-loading rigidity of dual prestressed concrete beam under cyclic loading are increased comparing with normal prestressed concrete beam.

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스트럿-타이 모델을 이용한 프리스트레스트 더블 T형 보의 정착부 거동 연구 (A Study on Behavior for Anchorage Zone in Prestressed Double T Beam Using Strut-Tie Model)

  • 김종욱;이두성;민창식
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 2002년도 봄 학술발표회 논문집
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    • pp.425-430
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    • 2002
  • This thesis is a study on behavior for anchorage zone in prestressed double T beam using strut-tie model. Stress conditions of Anchorage zone in prestressed double T beam are very disturbed because large concentrated forces act on relatively small areas. Hence, anchorage zone must be considered in Design of prestressed double T beam. If irrational design or irrational construction be conducted, that may lose stability in capacity as structure. In current design practice, certain parts of structure are designed with extreme accuracy, while anchorage zone in prestressed double T beam is designed using common sense, and experience. Therefore, it is generally very conservative. For that reason, logical, reasonable concept and accuracies are desired at design of anchorage zone in prestressed double T beam. Strut-tie method satisfies those desires. In this thesis, anchorage zone in prestressed double T beam is analyzed by considering prestressing forces. Strut-tie model is constructed based on principle stress trajectory obtained from 3D-finite element analysis in anchorage zone, and amounts of reinforcement be obtained. Results of analysis are compared with the way used in current design practice, and this thesis presents that strut-tie model can be an economical design than current design methods without losing the degree of safety.

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Experimental study of moment redistribution and load carrying capacity of externally prestressed continuous composite beams

  • Chen, Shiming;Jia, Yuanlin;Wang, Xindi
    • Structural Engineering and Mechanics
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    • 제31권5호
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    • pp.605-619
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    • 2009
  • A comparative experimental study of prestressed continuous steel-concrete composite beams was carried out. Two continuous composite beams were tested, one of which was plain continuous steel-concrete composite beam, while the other was a composite beam prestressed with external tendons. Cracking behavior and the load carrying capacity of the beams were investigated experimentally. Full plasticity was developed in the mid-span section each beam, the maximum moments attained at the internal support sections however were governed by local buckling which was related to the slenderness of composite section. It was found that in hogging moment regions, the ultimate resistance of an externally prestressed composite beam would be governed by either distortional lateral buckling or local buckling, or interactive mode of these two buckling patterns. The results show that exerting prestressing on a continuous composite beam with external tendons will increase the extent of internal force and moment redistribution in the beam. The influences of local and distortional buckling on the behaviors of the composite continuous beams are discussed. The Moment redistribution and the load carrying capacity of the prestressed continuous composite beams are evaluated, and it is found that at the ultimate state, the moment redistribution in the prestrssed continuous composite beams is greater than that in non-prestressed composite beams.

철골보에 연결된 프리스트레스 할로우 코아 슬래브 전단강도 (The Shear Strength of Prestressed Hollow-Core Slab on flexible steel beams)

  • 홍성걸;박경언;조봉호
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 2004년도 추계 학술발표회 제16권2호
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    • pp.397-400
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    • 2004
  • This research aims to estimate the shear strength of the composition of prestressed hollow-core slab and steel beam. The shear strength of prestressed hollow-core slab combined with the steel beam decreases, as the beam deflection increases to a considerable extent. Existing studies on the shear strength of prestressed hollow-core slab are mostly limited to 265mrn- and larger thickness slab on concrete beam. This study investigates the slab of 100mm-thickness combined with steel beam instead of concrete beam. Five shear connector methods are proposed and the shear strength is estimated with or without the beam deflection for each composition method, respectively. Finally the reduction coefficient $(\beta)$ for the transverse shear stress$(\tau_{zx})$, which is critical for the failure of prestressed hollow-core slab, is proposed.

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연속 프리스트레스트 콘크리트 빔교의 안전성 평가에 관한 연구 (A Study on the Safety Assessment of the Continuous Prestressed Concrete Beam Bridge)

  • 채원규
    • 한국산업안전학회:학술대회논문집
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    • 한국안전학회 1997년도 춘계 학술논문발표회
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    • pp.31-36
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    • 1997
  • In this thesis, the safety assessment method of the continuous prestressed beam bridge using the service load were studied. From the field test results of the continuous prestressed beam bridge, CAE(composite action factor) and $P_{n}$(capacity load of bridge) were assessed, and these factors were applied to safety assessment of the continuous prestressed beam bridge.

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Design curves for prestressed concrete rectangular beam sections based on BS 8110

  • Subramaniam, Kolluru V.L.;Sinha, S.N.
    • Structural Engineering and Mechanics
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    • 제3권6호
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    • pp.555-567
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    • 1995
  • Design curves have been prepared for prestressed rectangular beam section based on BS 8110, for determining area of steel for any given cross section, for stresses in concrete and steel and for the design moment. The design moment and the area of steel have been expressed in dimensionless form in terms of cross sectional dimensions and the characteristic strength of concrete. The choice and combination of design parameters result in considerably less number of curves as aid for design of rectangular prestressed beam sections, than those reported in CP 110 (Part 3).

Experimental investigation and design method of the general anchorage zone in the ring beam of prestressed concrete containment vessels

  • Chang Wu;Tao Chen;Yanli Su;Tianyun Lan;Shaoping Meng
    • Nuclear Engineering and Technology
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    • 제56권2호
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    • pp.485-497
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    • 2024
  • Ring beam is the main anchorage zone of the tendons in the nuclear power prestressed concrete containment vessel (PCCV). Its safety is crucial and has a great influence on the overall performance of PCCV. In this paper, two half-scale ring beams were tested to investigate the mechanical performance of the anchorage zone in the PCCV under multidirectional pressure. The effect of working condition with different tension sequences was investigated. Additionally, a half axisymmetric plane model of the containment was established by the finite element simulation to further predict the experimental responses and propose the local reinforcement design in the anchorage zone of the ring beam. The results showed that the ultimate load of the specimens under both working conditions was greater than the nominal ultimate tensile force. The original reinforcement design could meet the bearing capacity requirements, but there was still room for optimization. The ring beam was generally under pressure in the anchorage area, while the splitting force appeared in the under-anchor area, and the spalling force appeared in the corner area of the tooth block, which could be targeted for local strengthening design.

대공간 교육시설 축조를 위한 프리스트레스트 보에 사용되는 접합 강재의 성능평가에 대한 연구 (A Study for Structural Capacity Evaluation of Embedded Steel Plate Connected with Prestressed Concrete Beam to Build Large Space Educational Facilities)

  • 이경훈
    • 교육녹색환경연구
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    • 제10권2호
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    • pp.1-7
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    • 2011
  • An experimental study to evaluate structural capacity of an embedded plate connected with prestressed concrete beam was performed. Embedded steel plates and prestressed concrete beam were connected with stud-bolts at the ends of concrete beam specimens. About 1,000 kN concentrated load was applied at 450mm away from the end of beam specimen. A 3,000 kN capacity static Oil-jack was used to direct concentrated load. The maximum strain of stud-bolt recorded $90{\times}10^{-6}$(mm/mm) and wide width cracks were not founded. Any falling failures of concrete and large deformations were not founded either between steel plate and prestressed concrete specimen. As a result, construction performance can be improved using this embedded steel plate connection system apply to large space educational facilities.