• Title/Summary/Keyword: 중공율

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Evaluation of Serviceability and Flexural Performance for RC Hollow Slab by Hollow Ratio and Damping Ratio (중공율과 감쇠율을 이용한 RC 중공 슬래브의 사용성 및 휨성능 평가)

  • Jong Hoon Kim;Dong Baek Kim;Yong Gon Kim;Jae Won Lee;Jeong Ho Choi
    • Journal of the Society of Disaster Information
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    • v.18 no.4
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    • pp.930-935
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    • 2022
  • Purpose: The purpose of this study is to evaluate the stiffness reduction and damping ratio of reinforced concrete hollow slabs and to analyze their performance, and to study the effect of the damping effect of hollow bodies and the stiffness reduction on the serviceability of slabs. Method: Test specimen was made in a size of 0.6m*0.21m*3.6m to evaluate the vibration effect of the slab, and the hollow ratio was set in six steps from 0.0% to 30% to measure the change in rigidity and damping according to the change in the hollow ratio. Result: As the hollow ratio increases, rigidity decreases and the natural frequency decreases, but as the mass decreases, the natural frequency increases gradually. Since energy is hardly dissipated up to the hollow ratio of 20%, the hollow ratio should be reduced by 30%. Conclusion: It was found that the bending strength degradation of the slab with a hollow ratio of about 30% is minimized, but an appropriate natural frequency can be maintained, and a certain damping effect can be obtained.

A Study on the Noise and Vibration Damping Performance of RC Hollow Core Slab (중공형 RC 슬래브의 소음 및 진동 감쇠성능에 대한 연구)

  • Kim, Dong Baek;Kim, In Bae;Kim, Jong Hoon;Lee, Jae Won
    • Journal of the Society of Disaster Information
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    • v.15 no.2
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    • pp.292-300
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    • 2019
  • Purpose: To reduce the noise and vibration of reinforced concrete slab structures, the damping performance is to be performed experimentally after installing hollow core or filling it with liquid. Method: Using the hollow rate as an experimental variable, the damping ratio and stiffness of each test specimen at impact load are obtained to determine the difference between the damping ratio and stiffness of the numerical analysis. In addition, the damping effects are reviewed by comparing the difference in the damping ratio and stiffness of a test specimen filled with liquid 50% of the study. Results: Since the difference in resistance between a specimen with or without hollow core is 5%, it is judged that there is no structural problem, and the injection of liquid into the hollow core can increase the damping ratio, which can reduce noise or vibration. Conclusion: At less than 20% of hollow rate, there was little damping effect, and at 30%, damping effect was found. However, if liquid is injected into the hollow core of the specimen, damping rate is shown to increase, and the injection of liquid into the hollow part is believed to reduce noise or vibration.

Effects of Eluting Temperature and Time on Hollow Rate of Nylon High Hollow (용출온도와 시간이 Nylon 중공사의 중공율에 미치는 영향)

  • Kim, Sang-Ryong;Kim, Seung-Jin;Jo, Jin-Hwang;Lee, Jong-U;Jo, Dae-Hyeon
    • Proceedings of the Korean Society of Dyers and Finishers Conference
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    • 2008.10a
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    • pp.55-56
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    • 2008
  • 본 연구에서는 국내 기업에서 개발된 Nyoln P 입자첨가 마스터배치를 이용하여 방사공정에서의 방사온도와 Nylon sheath와 PET core 비율을 변화시켜 용출형 Nylon 중공사를 방사하여 용출온도, 용출시간 등 용출조건의 변화에 따라 Nylon 중공사의 중공율에 미치는 영향에 대해 분석하였고, 또한 용출된 상태를 보기 위해 용출형 나일론 중공사의 SEM 사진을 측정하였다. 이러한 결과를 토대로 개발된 나일론 용출형 중공사를 이용하여 고부가가치의 나일론 용출형 중공사 제품의 상품화 기술을 개발하는데 도움을 주는데 본 연구의 목적이 있다.

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An experimental Study on the Structural Performance Evaluation of One-way Hollow Core Slab (일방향 중공 슬래브의 구조성능 평가에 대한 실험적 연구)

  • Kim, Dong Baek;Song, Dae Gyeom;Choi, Jung Ho;Cho, Hyun Sang
    • Journal of the Society of Disaster Information
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    • v.14 no.3
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    • pp.343-351
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    • 2018
  • Purpose: Recently, As the size of the structure increased, the necessity of reducing its weight was raised. To reduce weight In concrete structures, a hollow slab is proposed as an alternative for weight reduction effect. Method: It is difficult to construct the hollow body due to buoyancy, and the shear performance is insufficient due to the decreased cross section. Slabs were fabricated using unidirectional hollow bodies such as PVC pipes, and experiments were conducted about construction performance and structural performance. Results: The buoyancy preventive device has been improved the construction performance by preventing floating hollow body, it has been confirmed that it has adequate performance to be used as a hollow slab system because it has enough expected shear performance. Coclusion: Hollow ratio has a little connection with bending performance, but after the yielding load, it is necessary to consider the secondary stiffness of structure, and is is supposed that the decrease of shear performance with the increase of hollow core ratio can be complemented with shear reinforcement.

Dynamic Characteristic of Post-tensioned Void Slab (포스트텐션 중공슬래브의 동적 특성)

  • Yoon, Sung-Won
    • Journal of Korean Association for Spatial Structures
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    • v.12 no.3
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    • pp.89-95
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    • 2012
  • Post-tensioned void slab is frequently used for improving the deflection and sound proofing. Two one story 8m spanned structures were built. One structure applied post-tensioned solid slab, but the other did post-tensioned void slab. Dynamic characteristics, which is natural frequency and damping ratio, was compared between that of solid slab and void slab before and after post tension. The natural frequency of void slab was greater than that of solid slab before and after post tension. It was shown that damping ratio of solid slab and void slab was almost same at two stages.

Polyethersulfone을 이용한 중공사막 제조시 내부응고제의 영향에 관한 고찰

  • 민병렬;조한욱;김상도
    • Proceedings of the Membrane Society of Korea Conference
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    • 1995.04a
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    • pp.22-23
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    • 1995
  • 한외여과막이 순수제조, 고분자물질의 분리, 폐수처리 등에 쓰이기 시작되면서, 높은 투과율, 내화학성, 충전밀도를 갖는 모듈이 요구되었다. 따라서 polysulfone(이하 PSf)을 막의 재질로 사용한 중공사형모듈이 주로 개발되었다. 그러나 본 연구에서는 PSf보다 투과율, 기계적 강도, 열적강도 및 화학적 성질 면에서 뛰어난 polythersulfone(이하 PES)을 막의 재질로 선택하였다. 또한, 지금까지는 수백 ${\AA}$에서 1mm정도의 외경(O.D.)을 갖는 중공사막이 개발되었다. 따라서 상당히 높은 충전밀도를 갖는 모듈은 개발되었으나, 점성이 높은 feed를 처리할 때, fouling이 큰 문제로 대두되었으며, 중공사막보다 외경이 큰 관형 막은 fouling에는 비교적 강하나, 충전밀도가 낮아서 단위부피당 flux가 낮은 단점을 갖고 있다. 따라서, 중공사막과 관형 막의 중간형태인 외경 2mm이상의 capillary membrane은 강한 fouling 저항과 비교적 높은 단위 부피당 투과율을 갖는다.

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Behaviors of Hollow R.C Columns with Internal Steel Tube by Hollow Ratio (강관으로 보강된 중공 R.C 기둥의 중공비에 따른 거동)

  • Choi, Jun-Ho;Yoon, Ki-Yong
    • Proceedings of the KAIS Fall Conference
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    • 2006.11a
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    • pp.106-110
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    • 2006
  • 중공 R.C 기둥은 중실 R.C 기둥에 비해 자중의 감소나 재료의 절감의 장점을 가지고 있다. 하지만 중공 R.C 기둥은 안쪽면의 취성파괴로 인하여 낮은 연성 거동을 할 가능성이 있다. 이러한 문제점을 해결하기 위해 중공 부재 내의 콘크리트 3축 구속 상태로 존재하게 하는 강관으로 보강된 중공 R.C 기둥이 강영종, 한택희 (2005) 등에 의해 개발되었다. 본 연구는 강관으로 보강된 중공 R.C 기둥에 대하여 중공비를 0.5~0.85까지 변화 시켜 중공비에 따른 작용하중에 대한 안전율, 연성도, 재료비에 대한 거동 특성을 파악하였다.

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Behaviors of Hollow RC Columns with Internal Steel Tube by Hollow Ratio (강관으로 보강된 중공 RC 기둥의 중공비에 따른 거동)

  • Choi, Jun-Ho;Yoon, Ki-Yong;Han, Taek-Hee;Kang, Young-Jong
    • Journal of the Korean Society of Hazard Mitigation
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    • v.7 no.3
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    • pp.1-7
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    • 2007
  • The hollow RC(Reinforced concrete) column has the effect of reducing weight and materials compared to solid RC column. However, the hollow RC column shows a low ductile behavior due to brittle failure of inside concrete. To overcome this problem, the internally confined hollow reinforced concrete column has been developed. In this study, the behavior of internally confined hollow RC columns were evaluated with safety ratio, ductility, total material cost, the total weight of the pier, etc. The hollow ratio is varied from 0.50 to 0.85.

Structural Performance Evaluation of Hollow Reinforced Concrete Half Slabs (철근콘크리트 중공 하프슬래브의 구조성능평가)

  • Hwang, Hyun-Bok;Kim, Sang-Woo;Hwang, Hyun-Sik;Lee, Ki-Jang;Lee, Jung-Yoon
    • Proceedings of the Korea Concrete Institute Conference
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    • 2008.04a
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    • pp.45-48
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    • 2008
  • This study is for proposing the shape of hollow and evaluating the structural performance of hollow reinforced concrete (RC) half slabs. The two-phase experimental works were carried out, and styrofoam was used for reduction of dead load and vibration. From the Phase I test result, the shape and spacing of the hollow were determined to obtain the high deduction ratio of the concrete and the desirable failure mode of the hollow RC half slabs. In the Phase II test, two slab specimens were tested in flexure to evaluate the flexural capacity of the hollow RC half slabs with the proposed hollow shape. In the result of the test, all the specimens having the proposed hollow shape showed sufficient flexural capacity.

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Study on the Vibration Characteristics of Light-Weight Void Composite Floor using GFRP (GFRP를 이용한 경량중공 합성 바닥의 진동 특성에 관한 연구)

  • Ryu, Jae-Ho;Park, Se-Ho;Ju, Young-Kyu;Kim, Sang-Dae
    • 한국방재학회:학술대회논문집
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    • 2010.02a
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    • pp.35.1-35.1
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    • 2010
  • 최근 고층형 주거 시설이 많이 보편화됨에 따라 층고절감과 시공의 효율성 제고 등에 대한 요구가 크게 증가하고 있다. 이에 층고를 절감하면서 동시에 장스팬을 구현할 수 있는 GFRP를 이용한 경량 중공 합성 바닥을 개발하였다. 이 바닥 시스템은 웨브에 개구부를 가지는 비대칭 철골보와 중공 경량체, 콘크리트 그리고 내력 보강 및 내화 성능 증진을 위해 비대칭 철골보 하부에 부착한 GFRP(Glass Fiber Reinforced Plastics)로 구성된다. 본 연구에서는 이 GFRP를 이용한 경량중공 합성 바닥의 진동 특성을 부재 단위 실험체를 제작하여 실험적으로 검토하였으며, 이를 통해 본 개발 합성 바닥의 고유 진동수 및 감쇠율을 측정하였다, 그 결과 기존의 이론에 근접한 진동 특성을 나타내었다.

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