• 한국공간구조학회:학술대회논문집
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• 한국공간구조학회 2005년도 춘계학술발표회 및 정기총회 2권1호(통권2호)
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• pp.175-182
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• 2005

The purpose of this study is to investigate experimentally the shear resisting behavior of the reinforced concrete beams strengthened with reinforcement materials(CFRP). Ten specimens were manufactured and tested under static monotonic loading. The main variables in the test were a space of steel reinforcement and direction of CFRP reinforcement. The test result Indicated that the method of CFRP increase significantly the shear strength of a reinforced concrete beam

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2015년도 춘계 학술논문 발표대회
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• pp.9-10
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• 2015

Generally significant reinforcement is used in nuclear power plant structures and may cause potential problems when concrete is poured. In particular pouring concrete into structural member joint area is more difficult than other areas since the joint area is very congested due to the crossed bars and the embedded plates, The purpose of this study is to solve these problems by applying Gr.80(550MPa) shear bars to containment structures of nuclear power plant. In order to apply them to containment structures, it is necessary to change ASME-CC code (ASME Sec.III Div.2). The structural performance tests of wall & beam have been done to compare Gr.80(550Mpa) with Gr.60(420MPa) shear bars. The test results and code change proposal were presented to ASME-CC Committee last year and the discussion for code change will be expected to proceed in the near future.

• 한국건설순환자원학회논문집
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• 제1권2호
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• pp.128-135
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• 2013

본 연구에서는 비정질 강섬유보강 콘크리트 슬래브의 전단성능을 분석하기 위하여 일면 전단 실험을 수행하였다. 주요 변수는 전단보강방법과 전단보강비이며, 1종류의 무전단보강실험체와 3종류의 전단보강실험체(전단철근, 0.25%, 0.5% 비정질 강섬유보강 실험체)의 일방향 슬래브 실험체를 제작하여 실험하였다. 실험결과, 0.25% 비정질 강섬유보강실험체는 전단 성능이 향상되었지만 0.5% 실험체는 0.25% 보강실험체에 비해 전단성능이 향상되지 않았다. 섬유 보강비에 따른 전단보강 효과를 파악하기 위한 추가적인 연구가 필요하다.

• 콘크리트학회논문집
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• 제26권4호
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• pp.533-543
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• 2014

최근 들어, 지하주차장과 같은 모듈화 건물에 프리캐스트 콘크리트와 현장타설 콘크리트가 함께 사용되는 복합공법의 사용이 증가하고 있다. 일반적으로 프리캐스트 콘크리트는 공장에서 선 제작되기 때문에 재료의 효율성을 극대화하기 위해 프리텐션을 도입하여 사용한다. 현행 구조기준이 긴장력이 가해진 단일 단면의 전단 강도식은 제시하지만 긴장력이 가해진 프리캐스트와 현장타설 콘크리트 합성단면의 전단강도식은 제시하지 못하고 있는 실정이다. 따라서 긴장력이 가해진 합성 부재의 전단강도 실험을 통해 긴장력이 전단강도에 미치는 영향과 합성부재의 전단강도 산정시 고려해야할 사항에 대해 알아보았다. 변수로는 콘크리트의 면적비, 긴장재의 긴장력, 전단 경간비, 그리고 전단철근비를 고려하였다. 실험 결과를 분석해보면, 전단강도는 긴장력 크기와 긴장력이 가해진 단면의 면적비가 커질수록 증가하였고 전단경간비가 증가할수록 감소하였다.

• Steel and Composite Structures
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• 제10권5호
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• pp.457-473
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• 2010

In this study, specimens were made with profile thicknesses and shear reinforcement as parameters. The bending and shear behavior were checked, and comparative analysis was conducted of the results and the theoretical values in order to see the applicability of T-section Modular Composite Profiled Beams (TMPB). In TMPB, the profiles of formwork functions play a structural role resisting the load. Also, the module concept, which is introduced into TMPB, has advantages: it can be mass-produced in a factory, it is lighter than an existing H-beam, it can be fabricated on the spot, and its section size is freely adjustable. The T1 specimens exhibited ductile behavior, where the whole section displayed strain corresponding to yielding strain at least without separation between modules. They also exhibited maximum strength similar to the theoretical values even if shear reinforcement was not applied, due to the marginal difference between shear strength and maximum bending monment of the concrete section. A slip between modules was incurred by shear failure of the bolts in all specimens, excluding the T1 specimen, and therefore bending moment could not be fully displayed.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2005년도 추계 학술발표회 제17권2호
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• pp.263-266
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• 2005

Recently, many researches for high-strength and high-durability concrete structure have remarkably been studied by adopting new construction material, fiber reinforced polymer (FRP). In connection with these research trend, the shearing capacity of concrete beams reinforced by GFRP stirrup which is developed in this study was evaluated. Experimental variables are span to depth ratio and spacing of shear reinforcement for test. In the result of test, the crack pattern, failure mode and shear load between shear steel reinforcement specimen and GFRP stirrup reinforcement specimen showed similar structural tendency. Therefore, it was investigated that the adaptability of shear-reinforced concrete structure with GFRP stirrup will be improved with further researches of shear design variables.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2008년도 추계 학술발표회 제20권2호
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• pp.185-188
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• 2008

플랫 플레이트 시스템은 펀칭전단과 같은 구조적 취약점이 있다. 펀칭전단의 저항력은 기둥단면의 증가, 슬래브 유효춤의 증가, 콘크리트 강도의 증가, 휨철근의 증가로 증가시킬 수 있다. 그러나 전단보강체를 설치하는 방법이 경제적, 시공적, 안정적으로 가장 좋은 방법이다. 하지만 슬래브 두께가 250mm보다 작은 슬래브에서는 전단보강체의 충분한 정착길이를 확보할수 없기 때문에 충분한 정착효과를 발휘하기 힘들다. 이전 연구에서 제안된 전단보강체의 경우 상부철근과 하부철근의 사이에 설치되었기 때문에 전단철근의 항복강도에 도달하기 전에 미끄러짐 파괴가 발생하였다. 정착강도의 영향을 주는 요인으로는 유효정착길이, 콘크리트강도, 전단철근의 직경, 정착상세이다. 본 연구에서는 슬래브 두께와 콘크리트 강도를 고려하여 제안된 보강체의 강도산정시 K factor를 제안하였다. 정착길이와 콘크리트강도를 고려함으로써 두께가 얇은 플랫플레이트 슬래브내에서 전단철근에 의한 전단강도를 정확히 산정할수 있을 것으포 판단된다..

• 콘크리트학회논문집
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• 제24권1호
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• pp.71-78
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• 2012

이 논문에서는 기존 PHC말뚝의 전단성능을 향상시키기 위하여 전단철근과 내부충전 콘크리트로 보강한 ICP 말뚝을 제안하였다. 허용응력 설계법을 바탕으로 전단철근 및 내부충전 콘크리트를 설계하였으며, 이를 바탕으로 2종류의 시험체를 제작하여 KS규격에 따라 전단시험을 수행하였다. 전단시험 결과, KS규격에 의거한 시험방법으로는 전단파괴를 얻을 수 없었으나, 제안된 방법에 의한 전단보강효과는 충분히 검증할 수 있었다. ICP말뚝 시험체의 전단 저항력은 기존 PHC말뚝에 비하여 평균 2배 이상으로 증진되는 것으로 나타났다. 또한 축방향 철근을 추가 보강한 ICP말뚝 시험체의 전단 저항력은 기존 PHC말뚝에 비하여 평균 2.5배 이상 증진되었다. 한편 허용응력설계법에 따라 결정된 ICP 말뚝의 허용 전단력에 비하여 시험으로 측정된 전단강도는 약 2.9 이상의 안전율을 갖는 것으로 나타났다.

• Structural Engineering and Mechanics
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• 제27권6호
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• pp.741-771
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• 2007

Tests were conducted on two partially pre-stressed concrete solid beams subjected to combined loading of bending, shear and torsion. The beams were designed using the Direct Design Method which is based on the Lower Bound Theorem of the Theory of Plasticity. Both beams were of $300{\times}300mm$ cross-section and 3.8 m length. The two main variables studied were the ratio of the maximum shear stress due to the twisting moment, to the shear stress arising from the shear force, which was varied between 0.69 and 3.04, and the ratio of the maximum twisting moment to the maximum bending moment which was varied between 0.26 and 1.19. The required reinforcement from the Direct Design Method was compared with requirements from the ACI and the BSI codes. It was found that, in the case of bending dominance, the required longitudinal reinforcements from all methods were close to each other while the BSI required much larger transverse reinforcement. In the case of torsion dominance, the BSI method required much larger longitudinal and transverse reinforcement than the both the ACI and the DDM methods. The difference in the transverse reinforcement is more pronounce. Experimental investigation showed good agreement between design and experimental failure loads of the beams designed using the Direct Design Method. Both beams failed within an acceptable range of the design loads and underwent ductile behaviour up to failure. The results indicate that the Direct Design Method can be successfully used to design partially prestressed concrete solid beams which cater for the combined effect of bending, shear and torsion loads.

• 대한조선학회지
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• 제20권4호
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• pp.9-16
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• 1983

When the perforated panels are under in-plane shear loads, shear buckling analysis is also necessary because of the presence of stress concentration around holes. To constrain it, we need some reinforcement. The methods of reinforcement are attaching doubler around hole and stiffeners in the arbitary directions. In this paper, two kinds of methods mentioned above are investigated, it is also clarified that which of the two is the more effective reinforcement. For the sake of convenience those arbitary directions were selected parallel ($90^{\circ}$) and oblique ($135^{\circ}$) to the edge. From the results of the above investigation, following conclusion was obtained. In case of parallel stiffeners, doubler reinforcement gives higher buckling strength than stiffener, however, in case of oblique stiffeners, doubler reinforcement gives higher buckling strength than doubler when the external load direction is known.