• Title/Summary/Keyword: 전단 거동

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Shear Behavior of R.C. Beams according to Increase of Concrete Compressive Strength (철근콘크리트 보의 고강도화에 따른 전단거동에 관한 연구)

  • 윤영수
    • Magazine of the Korea Concrete Institute
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    • v.6 no.6
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    • pp.190-198
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    • 1994
  • Th~s paper presents the shear behavior in reinforced normal, medium and high strength con crete beams due to the Increase of concrete compressive strength. Twelve shear tests were con ducted on full scale beam speclrnerls havmg concrete compressive stlengths of 360, 670 and 873kg/$cm^2$. Different amounts of shear reinforcement as a variable were investigated according to ACI 318 89. The shear responses are discussed in terms of the shear capacity. the ductility and the reserved strength. The prediction and comparison with the test results are also presented.

Shear Strength Model for HPFRCC Beams with Main Longitudinal Tensile Reinforcements (주인장 철근을 가진 HPFRCC 보 부재 전단 강도 예측 모델)

  • Lee, Seong-Cheol;Shin, Kyung-Joon
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.24 no.2
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    • pp.60-67
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    • 2020
  • Recently, many studies have been conducted on the structural behavior of HPFRCC, but most of the studies focused on the flexural behavior while studies on the shear behavior are limited. In this study, a model has been developed to reasonably predict the shear strength of a HPFRCC beam without stirrups. To develop the model, a HPFRCC beam was simply idealized with upper & lower chords resisting bending moment and a web shear element resisting shear forces. Then, taking into the account of the tensile behavior of HPFRCC, the main diagonal compressive strut angle and shear stress of the web shear element were evaluated on shear failure. Then, the shear strength of the HPFRCC beam could be evaluated. For the verification of the proposed model, the predictions by the proposed model were compared with the test results of 48 HPFRCC beams exhibiting shear failure. The results showed that the proposed model reasonably predicted the actual shear strength with an average of 1.045 and CoV of 0.125. This study are expected to be useful for related researches and design of members or structures to which HPFRCC is applied.

Analytical Study for Design of Shape and Arrangement Spacing of Studs in Steel Plate Concrete(SC) Wall subjected to Shear and Axial Forces (전단력과 축하중을 받는 강판 콘크리트(SC) 벽체에서 스터드의 형상과 배치간격의 설계를 위한 해석적 연구)

  • Cho, Sung-Gook;Lim, Jin-Sun;Jeong, Young-Do;Yi, Seong-Tae
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.18 no.4
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    • pp.67-76
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    • 2014
  • In this study, the behavior of Steel Plate Concrete (SC) walls subjected to shear and axial forces to investigate the effects of shape and arrangement spacing of studs on the design of SC walls was analytically reviewed. For this purpose, 9 cases of finite element analyses considering the different shape and spacing of studs in SC wall were performed. The results showed that the steel plate was yielded at the lower load than the second yielding shear force of the design skeleton curve when the spacing of stud is excessively far from each other. It is also found that the shape of the stud did not affect the shear behavior of SC wall but, the spacing influenced to its composite action. In this study, it was also proven that the inclined shaped stud resists more effectively to the bucking load than the general shaped stud in SC wall.

Shear Strength and Failure Mode of Architectural Masonry Walls (내진보강된 치장조적벽의 파괴특성과 전단강도)

  • Jin, Hee-Yong;Han, Sang-Whan;Park, Young-Mi
    • Proceedings of the Korea Concrete Institute Conference
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    • 2008.04a
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    • pp.89-92
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    • 2008
  • This study investigates the shear behavior of architectural masonry veneer wall reinforced with specific reinforcement details proposed by this study. For this purpose, experimental tests were conducted using one un-reinforced masonry(URM) wall specimen and three reinforced masonry(RM) wall specimens under quasi static cyclic loads. Un-reinforced(plain) masonry wall is expressed that behavior and failure mode are different for aspect ratio(L/H) and axial compressive force. The test variables are wall aspect ratio and presence of reinforcement. These specimens are masonry structure for architectural clading that is not to exist the axial compressive force. thus the axial compressive force is excepted from test variable. Test result, Behavior of specimens are dominated over rocking mode, but final failure modes are combined with different behaviors. And FEMA273 has proposed the equation of shear strength of masonry pier subjected to in-plane loading. Shear strength equations are classified four types of failure mode that is Rocking, and Toe-Crushing, Bed-Joint-Sliding and Diagonal-Tension. FEMA273 equations predict the behavior modes well, but shear strength is shown in different result.

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Nonlinear Shear Model of Fiber-Reinforced Cementitious Composite Panels (고인성 시멘트 복합체 패널의 비선형 전단모델)

  • Cho, Chang-Geun;Kim, Yun-Yong;Kim, Jeong-Sup
    • Proceedings of the Korea Concrete Institute Conference
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    • 2010.05a
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    • pp.155-156
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    • 2010
  • In current study, a nonlinear model for the shear behavior of Fiber-Reinforced Cementitious Composite (FRCC) panels has been introduced. The model is dealing with the multiple micro-cracking mechanism of FRCC materials which induce the high-ductile tensile characteristic, the compressive strain-softening, and the shear transfer mechanism in the cracked FRCC.

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Strength of Joint in Floating Structures Constructed with Precast Concrete Modules (프리캐스트 콘크리트 부유식 구조물의 모듈 접합부 강도)

  • Yang, In-Hwan;Kim, Kyung-Cheol
    • Journal of Navigation and Port Research
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    • v.36 no.3
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    • pp.197-204
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    • 2012
  • The behavior of floating structures constructed with precast concrete modules is dependent of the behavior of joints between the concrete modules. To accurately predict the floating structure response under the ultimate loading, knowledge of joint behavior is essential. This study aims to investigate the structural behavior of concrete module joints under various configuration of joint and confining stress levels. The shear behavior, shear capacity and crack patterns of shear keys in concrete module have been studied. Test results indicated that the shear capacity of joints increased as shear key inclination increased. In addition, shear capacity of concrete module joint increased with the increase of confining stress levels. The test results were compared with the AASHTO design recommendations. The AASHTO design recommendations underestimated the shear strength of test specimens.

Characteristics of velocity-dependent shear behavior of saw-cut rock joints at different shear velocities (편평한 암석절리면의 속도 의존적 전단거동 특성)

  • Park, Byung-Ki;Lee, Chang-Soo;Jeon, Seok-Won
    • Journal of Korean Tunnelling and Underground Space Association
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    • v.9 no.2
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    • pp.121-131
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    • 2007
  • Recently, the probability of rock joints being exposed to free faces is getting higher for the scale of rock mass structures gets larger. Also, the frequency of occurring dynamic events such as earthquakes and blasting has been increasing. Thus, the shear behavior of rock joints under different conditions needs to be investigated. In this study, a series of direct shear tests were carried out under various conditions to examine the velocity-dependent shear behavior of saw-cut rock joints. Two types of direct shear test were carried out. The first was to examine the velocity-dependent shear behavior of saw-cut rock joints at seven different shear velocities, each with three different normal stresses. The second was to examine the shear behavior of saw-cut rock joints when three different instantaneous shear velocities changed. As a result, the coefficient of friction was affected by normal stress. The breakpoint velocity, the point when the change of shear velocity starts to affect the frictional behavior, became lower as normal stress increased. Also, as the shear velocity became lower, the degree of stress-drop on stick-slip behavior became larger. As a result of examining the changes of friction coefficient, velocity weakening (decrease of friction coefficient) was observed. The decrement of friction coefficient due to the changes of shear velocity under slow shear velocity was larger than that under fast shear velocity.

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Analysis of Shear Behavior of Shear Key for Concrete Track on Railway Bridge Considering Construction Joint (타설 경계면을 고려한 철도교 콘크리트궤도 전단키의 전단 거동 해석)

  • Lee, Seong-Cheol;Kang, Yun-Suk;Jang, Seung Yup
    • Journal of the Korean Society for Railway
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    • v.19 no.3
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    • pp.341-350
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    • 2016
  • Concrete track on railway bridges should be designed to effectively respond to the movement of the superstructure of the bridge. In the design procedure, shear keys are generally placed on the protection concrete layer (PCL) before casting the concrete track so the shear force due to slip between the concrete track and the bridge super-structure can be transferred. In this paper, a nonlinear structural analysis procedure that considers the construction joint has been developed to predict the shear behavior of a shear key. With the developed analysis procedure, it was possible to predict the shear force-shear slip response at the construction joint in a shear key by considering the friction of concrete surface and the dowel action of the rebars. The analysis results showed good agreement with the test results for 4 specimens.

Experimental Study on the Shear Behavior of Reinforced Hooked-Steel-Fiver Concrete Beams (훅트강섬유보강 철근콘크리트보의 전단거동에 대한 실험적 연구)

  • 심종성;이차돈;김규선;오홍섭
    • Magazine of the Korea Concrete Institute
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    • v.7 no.5
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    • pp.179-188
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    • 1995
  • SFRC overcomes brittleness of concrete and has increases strength due to the action of confmement, crack arrestmg mechan~sm and pull out resistances of steel f~bers ~ n s ~ d e the concrete. These lead also to the increased strength and ductility under the shear stress. It has been reported that the secondary remforcement effect of steel fibers IS more pronounced In shear than flexure. Addition of hooked stee!, fibers into the cementitious materials enhanced shear resistance and consequently improves structural behavior and shear strength of Reinforced Hooked-Steel-Fiber Concrete Ream(RHSFCI3) under the shear forces. Experimental observations were made on the main parameters effecting structural behavior of RHSFCB in this study. The volume fractions of fibers, shear span to depth ratios, and spaclngs of stlrrups were taken into account as the mam parameters. Some eyuatlons reported in the literatures, regardmg the predict~ons of the shear strength of RHSFCB have been evaluated stdtlst~cdlly based on the tot a1 number of 95 test results on RHSFCB faded In shear on shear flexu~al mode.

A Study on the Effect of Normal Stress on the Joint Shear Behavior (절리면 전단거동에서의 법선응력 영향 고찰)

  • Cho, Taechin;Suk, Jaewook
    • Tunnel and Underground Space
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    • v.23 no.3
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    • pp.203-211
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    • 2013
  • Shear behavior of joint plane has been investigated considering the magnitude of normal stresses and initial surface roughness. Shear strength of joint plane has been measured by performing the multi-stage shear test in which applied normal stress level has been increased stepwise. Multi-stage shear test within the specified normal stress range has been repeated and two types of strength parameter variation have been observed: type 1 - both cohesion and friction angle decrease, type 2 - cohesion decrease and friction angle increase. Trends of strength parameter variation for the three rock types, gneiss, granite and shale, have been investigated and the influence of initial roughness of joint plane on the sequential shear strength change for the repeated multi-stage shear tests also has been analyzed.