• Title/Summary/Keyword: reinforced joints

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Development of Reinforced Concrete Column and Steel Beam Composite Joints (철근콘크리트 기둥과 철골 보 합성구조 접합부 시스템 개발)

  • 김도균;정하선;최완철
    • Proceedings of the Korea Concrete Institute Conference
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    • 2001.05a
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    • pp.691-698
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    • 2001
  • Recent trends in the construction of long span or tall building frames feature the increase use of composite members that steel and concrete is functioning together in what terms of mixed structural systems. One of such systems, RCS (reinforced concrete column and steel beam) system is introduced and closely examined focusing on bearing strength of the composite joint in this paper. The main objective of this study was to develope detail to increase bearing capacity while bearing failure is one of the two primary modes of failure in RCS system. The results show that specimens with the U-type bearing reinforcement detail developed in this study enhanced the bearing strength by 1.20-1.50. The U-type reinforcement is the effective details to increase joint bearing strength compared to others like vertical reinforcement welded to beam flanges.

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Reliability of column capacity design in shear

  • Thomos, George C.;Trezos, Constantin G.
    • Computers and Concrete
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    • v.10 no.5
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    • pp.507-521
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    • 2012
  • The capacity design of shear forces is one of the special demands of EC8 by which the ductile behavior of structures is implemented. The aim of capacity design is the formation of plastic hinges without shear failure of the elements. This is achieved by deriving the design shear forces from equilibrium conditions, assuming that plastic hinges, with their possible over-strengths, have been formed in the adjacent joints of the elements. In this equilibrium situation, the parameters (dimensions, material properties, axial forces etc) are random variables. Therefore, the capacity design of shear forces is associated with a probability of non-compliance (probability of failure). In the present study the probability of non-compliance of the shear capacity design in columns is calculated by assuming the basic variables as random variables. Parameters affecting this probability are examined and a modification of the capacity design is proposed, in order to achieve uniformity of the safety level.

Study on the Fatigue Behavior of a Joint between RC and SFRC Subjected to Shear (철도하중에 대한 철근 콘크리트와 강섬유 보강 철근 콘크리트 전단이음부의 피로거동에 관한 실험적 연구)

  • 강보순
    • Journal of the Korean Society for Railway
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    • v.3 no.4
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    • pp.194-202
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    • 2000
  • Fatigue behavior of shear joints between the combined reinforced concrete(RC) and the reinforced steel fiber concrete(SFRC) specimens has been experimentally investigated. Experimental parameters used are the amount of steel fiber and the type of shear joint. Six specimens have been tested under static load, and eight specimens have been subjected to the fatigue load in a range of 50 % and 5 % of the ultimate static load. The purpose of this research is to propose an empirical formula for fatigue shear behavior of the combined RC and SFRC structures on the basis of experimental result. It can be observed from experimental results that addition of steel fibers to concrete specimen increases the static ultimate load by approximately 25 %, enhances the fatigue behavior, and also reduces vertical and lateral displacements at the shear joint for a given load cycle after the occurrence of first crack.

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Analytical Study on Precast Segmental Prestressed Concrete Bridge Piers (조립식 프리스트레스트 콘크리트 교각에 관한 해석적 연구)

  • Kim, Tae-Hoon;Jin, Byeong-Moo;Kim, Young-Jin;Shin, Hyun-Mock
    • Proceedings of the Korea Concrete Institute Conference
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    • 2006.05a
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    • pp.178-181
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    • 2006
  • The purpose of this study is to investigate the inelastic behavior of precast segmental prestressed concrete bridge piers. A computer program, named RCAHEST (Reinforced Concrete Analysis in Higher Evaluation System Technology), for the analysis of reinforced concrete structures was used. Material nonlinearity is taken into account by comprising tensile, compressive and shear models of cracked concrete and a model of reinforcing steel. An unbonded tendon element based on the finite element method, that can represent the interaction between tendon and concrete of prestressed concrete member, is used. A joint element is newly developed to predict the inelastic behaviors of segmental joints. The proposed numerical method for the inelastic behavior of precast segmental prestressed concrete bridge piers is verified by comparison with reliable experimental results.

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A Study on the Shear Characteristic of├ Type Reinforced Concrete Joints under Cyclic Loading (반복하중을 받는 ├형 철근콘크리트 접합부의 전단특성에 관한 연구)

  • 이상호;이동화
    • Journal of the Earthquake Engineering Society of Korea
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    • v.5 no.2
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    • pp.73-82
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    • 2001
  • 본 연구는 실험적 방법과 해석적 방법을 통하여 반복하중을 받는 ├형 철근콘크리트 접합부의 전단특성을 파악함을 목적으로 한다. ├형 접합부는 고강도 재료의 사용으로 인한 체적의 감소 뿐만 아니라, 지진발생 시 반복하중의 작용으로 인한 변동축력 등으로 , 구조적으로 취약한 부분이 될 가능성이 있다. 따라서 본 연구에서는 ├형 접합부의 전단특성을 파악하기 위하여 기동축력, 콘크리트 압축강도, 접합부 전단보강근비를 변수로 한 12개의 실험체를 제작하여 가력실험을 수행하였다. 또한, 유한요소 해석을 수행하여 본 실험결과와의 비교 검토를 통하여 타당성을 검토한 후, 기둥축력과 콘크리트 압축강도의 변화에 대한 변수해석을 통하여 접합부의 전단강도에 미치는 변수는 영향을 파악하였으며, 실험에 의한 실험체의 전단내력을 기존에 제안된 AIJ, ACI 규준 등과 비교 검토하였다. 본 연구의 결로부터 기둥축력과 콘크리트 압축강도가 ├형 철근콘크리트 접합부의 전단강도에 미치는 영향을 확인하였다.

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Investigating loading rate and fibre densities influence on SRG - concrete bond behaviour

  • Jahangir, Hashem;Esfahani, Mohammad Reza
    • Steel and Composite Structures
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    • v.34 no.6
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    • pp.877-889
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    • 2020
  • This work features the outcomes of an empirical investigation into the characteristics of steel reinforced grout (SRG) composite - concrete interfaces. The parameters varied were loading rate, densities of steel fibres and types of load displacement responses or measurements (slip and machine grips). The following observations and results were derived from standard single-lap shear tests. Interfacial debonding of SRG - concrete joints is a function of both fracture of matrix along the bond interface and slippage of fibre. A change in the loading rate results in a variation in peak load (Pmax) and the correlative stress (σmax), slip and machine grips readings at measured peak load. Further analysis of load responses revealed that the behaviour of load responses is shaped by loading rate, fibre density as well as load response measurement variable. Notably, the out-of-plane displacement at peak load increased with increments in load rates and were independent of specimen fibre densities.

Investigation of semi-rigid bolted beam connections on prefabricated frame joints

  • Irtem, E.;Turker, K.
    • Structural Engineering and Mechanics
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    • v.12 no.4
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    • pp.397-408
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    • 2001
  • Bolted connections are used commonly in the precast reinforced concrete structures. In such structures, to perform structural analysis, behaviour of connections must be determined. In this study, elastic rotation stiffness of semi-rigid bolted beam connections, applied in industrial precast structures, are determined by finite element methods. The results obtained from numerical solutions are compared with an experimental study carried out for the same connections. Furthermore, stress distributions of the connection zone are determined and a reinforcement scheme is proposed. Thus, a more appropriate reinforcement arrangement for the connection zone is enabled. The connection joint of the prefabricated frame is described as rigid, hinged or elastic, and a static analysis of the frame system is performed for each case. Values of bending moments and displacements obtained from the three solutions are compared and the effects of elastic connection are discussed.

FRP or steel plate-to-concrete bonded joints: Effect of test methods on experimental bond strength

  • Chen, J.F.;Yang, Z.J.;Holt, G.D.
    • Steel and Composite Structures
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    • v.1 no.2
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    • pp.231-244
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    • 2001
  • The strengthening of reinforced concrete structures using externally bonded steel or advanced fibre reinforced plastic (FRP) composites is becoming increasingly common. A key factor affecting the behaviour and reliability of such strengthened structures is the bond strength between the steel or FRP plate and the concrete substrate. Several different experimental set-ups have previously been used to determine bond strength. This paper presents a careful finite element analysis of the stress distributions in these test set-ups. Results show that stress distributions can be significantly different for different set-ups, for similar materials and geometry.

Performance assessment of precast concrete pier cap system

  • Kim, T.H.;Kim, Y.J.;Shin, H.M.
    • Computers and Concrete
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    • v.13 no.4
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    • pp.501-516
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    • 2014
  • The purpose of this study was to investigate the performance of precast concrete pier cap system. The proposed precast pier cap provides an alternative to current cast-in-place systems, particularly for projects in which a reduced construction time is desired. Five large-scale pier cap specimens were constructed and tested under quasistatic monotonic loading. The computer program, RCAHEST (Reinforced Concrete Analysis in Higher Evaluation System Technology) was used for the analysis of reinforced concrete structures. A bonded tendon element is used based on the finite element method, and can represent the interaction between the tendon and concrete of a prestressed concrete member. A joint element is used in order to predict the inelastic behaviors of segmental joints with a shear key. This study documents the testing of the precast concrete pier cap system under monotonic loading and presents conclusions and design recommendations based on the experimental and analytical findings. Additional full-scale experimental research is needed to refine and confirm design details, especially for actual detailing employed in the field.

Nonlinear Finite Element Analysis of Precast Segmental Prestressed Concrete Bridge Columns (조립식 프리스트레스트 콘크리트 교각의 비선형 유한요소해석)

  • Kim, Tae-Hoon;Jin, Byeong-Moo;Kim, Young-Jin;Shin, Hyun-Mock
    • Proceedings of the Earthquake Engineering Society of Korea Conference
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    • 2006.03a
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    • pp.292-299
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    • 2006
  • The purpose of this study is to investigate the inelastic behavior of precast segmental prestressed concrete bridge columns. A computer program, named RCAHEST (Reinforced Concrete Analysis in Higher Evaluation System Technology), for the analysis of reinforced concrete structures was used. Material nonlinearity is taken into account by comprising tensile, compressive and shear models of cracked concrete and a model of reinforcing steel. An unbonded tendon element based on the finite element method, that can represent the interaction between tendon and concrete of prestressed concrete member, is used. A joint element is newly developed to predict the inelastic behaviors of segmental joints. The proposed numerical method for the inelastic behavior of precast segmental prestressed concrete bridge columns is verified by comparison with reliable experimental results.

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