• Title/Summary/Keyword: lapped splice

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A Study on Benefit/Cost Analysis of Re-Bar Connection Methods for Hyper Strength(SD500) Reinforcement (SD500철근 커플러 이음의 편익/비용분석에 관한 연구)

  • Kim, Jae-Yeob;Kwon, Yeo-Wool;Kim, Jun-Young
    • Journal of the Korea Institute of Building Construction
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    • v.8 no.2
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    • pp.81-87
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    • 2008
  • High-rise building is taking a place as one of building types from apartment housings to commercial buildings. With taking in account of stability and durability, strength of used materials is increasing gradually in these high-rise buildings. According to this, frequency in use of SD500 re-bar is increasing gradually in high-rise buildings. However the study of SD500 re-bar is insufficient because SD500 re-bar started to be used for domestic buildings lately. Specially because there is no guide or study to refer to, people get into difficulties when to decide the method of re-bar connection in construction using SD500 re-bar. Accordingly in this study, it suggests the method of estimating the economical efficiency on SD500 re-bar connection, and conducts benefit/ cost analysis on lapped splice and coupler splice by applying AHP theory, and then presents its result. After to analyze re-bar diameter of D25, 29, and 32, finally we attained the result that the coupler splice is advantageous in all parts of benefit/ cost more than the lapped splice.

An evaluation of compressive lap splice of the D22 rebar by concrete strengths (콘크리트 강도변화에 따른 D22mm 철근의 압축이음 성능 평가)

  • Lee, Sung-Ho;Chun, Sung-Chul;Oh, Bo-Hwan
    • Proceedings of the Korea Concrete Institute Conference
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    • 2008.04a
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    • pp.1081-1084
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    • 2008
  • Column specimens were constructed with main parameters significantly affecting the strength of the compression lap splice, such as lap length, spacing of lapped bars, amount and location of transverse reinforcements, and concrete strength. An experimental study has been conducted with column specimens in concrete strength of 40 to 60 MPa. Diameters of lapped reinforcing bars are 22 mm. An axial load was monotonically applied to the column specimens. All specimens failed in a brittle sudden manner and cover concrete was blasted out at maximum load. Compression lap splice strengths of specimens were evaluated from strains measured at the beginning of the lap length. Effects of the main parameters on the strengths of compression lap splice are assessed. Similarly to strengths of tension lap slice, the compression splice strength is found to be affected by lap length, spacing of lapped bars, transverse reinforcements.

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Analytical Study on Splice Performances with the Vertical Noncontact Lapped of Reinforcing Bars (수직으로 비접촉 겹침이음된 철근의 이음성능에 관한 해석적 연구)

  • Lee Ho-Jin;Kim Seung-Hun;Ha Sang-Su;Moon Jeong-Ho;Lee Li-Hyung;Lee Yong-Taeg
    • Proceedings of the Korea Concrete Institute Conference
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    • 2005.05a
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    • pp.171-174
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    • 2005
  • In this study, new moment-resisting precast concrete beam-column joint is proposed for moderate seismic regions. It has the connection reinforcing bars, penetrated the joint and lap-spliced with the bottom bars of precast U-beam. To evaluate the performance for noncontact lapped splice, analytical works were conducted. Major variables for FEM analysis are the length of lap, the diameter of connection reinforcing bars, and the distance between lapped bars. The results of this study show thar the these variables has much influence on strength and deformation of lapped joint.

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Effect of Flexural Performance on U-Shaped Precast Concrete Beams with Noncontact Lapped Splice (비접촉 겹침 이음된 프리캐스트 U형 보의 휨성능에 미치는 효과)

  • Ha, Sang-Su;Kim, Seung-Hun
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.12 no.6
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    • pp.119-128
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    • 2008
  • In this study, new moment-resisting precast concrete beam-column joint is proposed for moderate seismic regions. It has the connection reinforcing bars, penetrated the joint and lap-spliced with the bottom bars of precast U-shaped PC beam. To evaluate the performance for noncontact lapped splice, experimental and analytical works were conducted. Major variables for tests are the length of lap, the diameter of connection reinforcing bars, and the distance between lapped bars. Analytic research was performed nonlinear finite element method. Analytic research focused on crack pattern, load-deflection curve, comparison of internal force, evaluation of ductility strains of reinforcement bar. Results of experimental and analytical works show that the these variables has much influence on flexural strength and ductility, and joint behavior.

Bond & Lapped Splices in High-Strength Concrete Structures (고강도 콘크리트 구조물의 철근 부착 및 이음에 대한 연구)

  • 김준성
    • Magazine of the Korean Society of Agricultural Engineers
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    • v.39 no.6
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    • pp.122-130
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    • 1997
  • An experimental study was conducted to evaluate the bond performance of reinforcing bars embedded in high-strength concrete. Four bond specimens and ten beam splice specimens using concrete with compressive strength of 246kgf/$cm^2$ and 64lkgf/$cm^2$ were tested. The effect of several variables on basic development length and compressive strength of concrete is discussed in splice specimens. The test results showed that the current trend in concrete specification of making the splice length longer to compensate for having smaller cover and spacing may not be an effective approach.

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An Experimental Study on Effects Transverse Reinforcement in Lap-Spliced Tension Reinforcing Bars (인장철근의 겹침이음에서 횡보강근의 효과에 관한 실험적 연구)

  • 이호준;최선아;연규원;박찬수
    • Proceedings of the Korea Concrete Institute Conference
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    • 2000.10b
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    • pp.879-884
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    • 2000
  • In this study, an experimental work is conducted to evaluate the bond performance between reinforcing bars and surrounding concrete in a lapped splice. The major variable of this test is a transverse reinforcement in lap-spliced tension reinforcing bars. The test results indicate that the bond strength per unit splice length increases with an increase in the transverse reinforcement factor $K_{\alpha}$. The specimens taken less than (c+$K_{tr}$)/$d_b$=3.0 tend to be very brittle at failure. But the specimens taken longer than (c+$K_{tr}$)/$d_b$=3.0 tend to be somewhat ductile at failure.

An Experimental Study on the Effect of Tie-wire on R/C Beam Behaviors (결속선이 R/C보의 거동에 미치는 영향에 대한 실험적 연구)

  • 변항룡;공귀옥;김준성;이수곤
    • Proceedings of the Korea Concrete Institute Conference
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    • 1997.10a
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    • pp.737-742
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    • 1997
  • In this paper the effect of tie wire in lap spliced bars is investigated by experiment. The variables considered in the beam behaviors are beam dimension, lapped splice length and numbers of tie wire. 3 test pieces having the same variables consist one series and a total of 6 series ar tested. The test results show the beam behavior is not affected by numbers of tie wire but by the manner of tie. It was revealed hat the load bearing capacity of the beam is increased when the tie wire is extended to top bar.

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Lapped Splices in High-Strength Concrete Flexural Members (고강도 콘크리트 휨 부재의 철근 겹이음에 대한 연구)

  • Kim, Woo;Kim, Jun-Seong;Kim, Dae-Joong;Son, Young-Hyun
    • Proceedings of the Korea Concrete Institute Conference
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    • 1996.10a
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    • pp.447-452
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    • 1996
  • An experimental study was conducted to evaluate the bond performance of reinforcing bars embedded in high-strength concrete. Ten beam spice Specimens using concrete with compressive strength of 240kg/$\textrm{cm}^2$ and 640kg/$\textrm{cm}^2$ were tested. The effect of several variables on basic development length is discussed. The test results showed that the current trend in concrete specification of making the splice length longer to compensate for having smaller cover and spacing may not be an effective approach.

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A Study on the Mechanical Properties of Gas Pressure Welded Splices of Deformed Reinforcing Bar (가스압접 이형철근의 기계적 강도 특성 연구)

  • Jeon, Juntai
    • Journal of the Society of Disaster Information
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    • v.11 no.4
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    • pp.520-526
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    • 2015
  • Reinforcing bar splices are inevitable in reinforced concrete structure. In these days, there are three main types of splices used in reinforced concrete construction site - lapped splice, mechanical splice and welded splice. Low cost, practicality in construction site, less time consuming and high performance make gas pressure welding become a favorable splice method. However, reinforcing bar splice experiences thermal loading history during the welding procedure. This may lead to the presence of residual stress in the vicinity of the splice which affects the fatigue life of the reinforcing bar. Therefore, residual stress analysis and tensile test of the gas pressure welded splice are carried out in order to verify the load bearing capacity of the gas pressure welded splice. The reinforcing bar used in this work is SD400, which is manufactured in accordance with KS D 3504. The results show that the residual stresses in welded splice is relatively small, thus not affecting the performance of the reinforcing bar. Moreover, the strength of the gas pressure welded splice is high enough for the development of yielding in the bar. As such, the reinforcing bar with gas pressure welded splice has enough capacity to behave as continuous bar.

Study for the Structural walls with Interlocking Spirals on the boundary (단부에 Interlocking Spiral을 가진 전단벽의 거동에 관한 연구)

  • 홍성걸;김록배;정하선;구광현
    • Proceedings of the Korea Concrete Institute Conference
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    • 2001.05a
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    • pp.865-870
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    • 2001
  • This paper propose a new seismic detail for ductility enhancement by interlocking spiral reinforcement in the potential yield regions of a wall. Through the theoretical consideration and experiment program, confinement with interlocking spirals lead the structural walls to ductile behavior. All specimens show stable hysteretic behavior and good energy dissipation capacity. Also the increase of shear strength mainly induces a flexural failure mode. As interlocking spiral are used in lapped splice region, they increase the bond strength and prevent a early tensile failure caused by the loss of bond stresses. Consequently, the confinement with interlocking spirals may result in a lower value of force reductions factor, newly proposed detail will be provide more economical design.

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