• 제목/요약/키워드: lightweight

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구조용 경량골재 콘크리트의 폭렬특성 (Explosive Spalling of Structural Lightweight Aggregate Concrete)

  • 송훈;이종찬;이세현;김우재
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 2006년도 춘계 학술발표회 논문집(II)
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    • pp.477-480
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    • 2006
  • Normally, with all ensuring the fire resistance structure as a method of setting the required cover thickness to fire, the RC is significantly affected from the standpoint of its structural stability that the compressive strength and elastic modulus is reduced by fire. Especially, high strength concrete and lightweight aggregate concrete is occurred serious fire performance deterioration by explosive spalling. Thus, this study is concerned with explosive spalling of lightweight concrete using structural lightweight aggregate. From the experimental test result, lightweight aggregate concrete is happened explosive spalling. The decrease of cross section caused by explosive spalling made sharp increasing gradient of inner temperature.

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경량골재를 사용한 자기충전 콘크리트의 탄산화 (The carbonation of self-consolidating concrete using lightweight aggregate)

  • 김용직;김영진;최연왕
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 2009년도 춘계 학술대회 제21권1호
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    • pp.245-246
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    • 2009
  • 일반적으로 경량콘크리트는 구조물의 자중을 줄일 수 있는 장점 때문에 부재단변의 축소 및 시공 의 간편화를 이룰 수 있어 장경간 교량 및 초고층 건물 등에 적용하여 시공비용을 절감함 수 있는 효과가 있다. 그러나 경량골재는 골재자체의 특성상 콘크리트 제조시 굳지 않은 상태에서 재료분리를 일으킬 수 있다. 따라서, 본 연구에서는 경량골재를 자기충전콘크리트 배합설계에 적용하였으며, 역학적 특성과 탄산화에 대하여 검토하였다.

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벽체용 경량 콘크리트의 제조 및 흡차음 특성에 관한 연구 (A Study on the Sound Characteristic of Insulation and Manufacturing of Lightweight Concrete for Wall System)

  • 김홍룡;김순호
    • KIEAE Journal
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    • 제6권1호
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    • pp.11-16
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    • 2006
  • This paper deals with the experimental for manufacturing the lightweight buildng materials with portland cement, fly ash, slag, lime, gypsum, and aluminum powder system. Aluminum powder was added an aerating agent. Specific gravity range of lightweight concrete specimens were 0.6~0.9g/cm3. These specimens properties studied by means of specific gravity, compressive strength, absorption coefficient, transmission loss and scanning electron microscopy. Cellular concrete with maximum compressive strength was 41kgf/cm2 by obtained Al=0.05wt.%. Moreover, the aeration lightweight concrete showed excellent sound absorption properties.

완충재 동탄성계수와 경량바닥충격음 저감량의 상관성 (Correlation Between Dynamic Stiffness of Resilient Materials and Lightweight Floor Impact Sound Reduction Level)

  • 김경우;정갑철;손장열
    • 한국소음진동공학회논문집
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    • 제18권8호
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    • pp.886-895
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    • 2008
  • Resilient materials are generally used for the floating floors to reduce the floor impact sound. Dynamic stiffness of resilient material have a close relation with the floor impact sound reduction. In this study, to examine the relationship between dynamic stiffness and lightweight impact sound level, the dynamic stiffness and floor impact sound level of 51 resilient materials were measured. The impact sound level of each of these resilient materials, whose dynamic stiffness was measured, was measured before and after installation, and the level difference (${\Delta}L$) was analyzed. The result of test showed that the dynamic stiffness of resilient materials decreased, the lightweight impact sound level also decreased, and there was a correlation between the dynamic stiffness and the lightweight impact sound, especially in the low frequency domain.

경량콘크리트 제조를 위한 경량골재 사전흡수수 품질관리방안 (A Study on The Quality Control of Pre-absorbed Water Light-weight Aggregate Concrete)

  • 임상준;이한우;이병수
    • 한국건축시공학회:학술대회논문집
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    • 한국건축시공학회 2011년도 추계 학술논문 발표대회
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    • pp.199-200
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    • 2011
  • Absorption of lightweight aggregate affects the properties of fresh and hardened concrete, so care must be taken. In this study, according to KS F 2533 absorption is measured to aggregate size, submerged time, holding time and practically ways to maintain a constant absorption was to seek. The findings for quality control of the lightweight aggregate concrete mixture is saturation of the surface-dry aggregate humidity 100% after 24 hours immersion in the environment has been stored for more than two days to absorb the state was able to define. Dry density at the surface of the lightweight aggregate and lightweight concrete mix design and placement is possible for it to apply.

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인공경량콘크리트의 마모저항성에 관한 연구 (Research on Abrasion Resistance of Artificial Lightweight Concrete)

  • 이창수;유보선;남창식
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 2010년도 춘계 학술대회 제22권1호
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    • pp.205-206
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    • 2010
  • 본 연구는 인공경량콘크리트와 보통콘크리트의 마모저항성에 대한 실험이다. 동일조건에서는 인공경량콘크리트의 마모손실률이 물-결합재비가 커짐에 따라 더욱 증가하지만 플라이애쉬를 혼입한 경우 마모손실률의 차이는 감소하며 물-결합재 30%와 플라이애쉬 15%인 경우 인공경량콘크리트와 보통콘크리트의 마모손실률의 차이는 약 3%정도로 거의 발생하지 않았다.

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고강도-경량콘크리트의 실용화를 위한 기초적 실험 연구 (Fundamental Tests of High Strength Lightweight Concrete for Application)

  • 이재삼;김정식;강훈;최명신;안종문;신성우
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 1997년도 가을 학술발표회 논문집
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    • pp.393-400
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    • 1997
  • It is possible to reduce dead load and cross section of structural members by use of lightweight concrete, and also reduce the cost of construction. The mechanical properties of lightweight concrete are lower than that of normal weight concrete having the same compressive strength, then it is necessary to make higher strength of lightweight concrete for structural use, and the objective of this paper is to development and application the highstrength lightweight concrete with lower than 2.0t/$\textrm{m}^3$ of unit weight and over than 350kg/$\textrm{cm}^2$ of compressive strength.

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경량 모델의 삼각 요소망으로부터 경계 곡선 추출 방법 (A Boundary Curve Extraction Method using Triangular Elements of a Lightweight Model)

  • 권기연
    • 한국CDE학회논문집
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    • 제22권1호
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    • pp.28-36
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    • 2017
  • Sharing of CAD data plays a key role in the PLM and a lightweight model is widely used for visualizing and sharing a large data. The lightweight model is mainly composed of triangular elements to minimize file size. There is no problem at all to visually confirm the shape based on these triangular elements but there is a limit to numerically calculate the exact position on the curve or surface. In this paper, a boundary curve generation method using triangular elements is proposed to increase the utilization of lightweight models. After matching connectivity of triangular elements, boundary element edges are extracted. Boundary curves are generated by connecting of these boundary element edges. This proposed method has been tested on several models to demonstrate the feasibility.

고강도 경량 자기충전콘크리트의 건조수축 및 중성화 특성 (Drying Shrinkage and Carbonation of High Strength Lightweight Self-Compacting Concrete)

  • 최욱;최연왕;김용직;강현진;조선규
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 2005년도 봄학술 발표회 논문집(II)
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    • pp.77-80
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    • 2005
  • Lightweight concrete is known for its advantage of reducing the self-weight of the structures, reducing the areas of sectional members as well as making the construction convenient. Thus the construction cost can be saved when applied to structures such as long-span bridge and high rise buildings. However, the lightweight concrete requires specific mix design method that is quite different from the typical concrete, since using the typical mix method would give rise the material segregation as well as lower the strength by the reduced weight of the aggregate. In order to avoid such problems, it is recommended to apply the mix design method of self-compacting concrete for the lightweight concrete. Experimental tests were performed as such compressive strength, dry shrinkage and carbonation of high strength lightweight self-compacting concrete.

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Local bond stress-slip behavior of reinforcing bars embedded in lightweight aggregate concrete

  • Tang, Chao-Wei
    • Computers and Concrete
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    • 제16권3호
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    • pp.449-466
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    • 2015
  • This paper aims to study the local bond stress-slip behavior of reinforcing bars embedded in lightweight aggregate concrete (LWAC). The experimental variables of the local bond stress-slip tests include concrete strength (20, 40 and 60 MPa), deformed steel bar size (#4, #6 and #8) and coarse aggregate (normal weight aggregate, reservoir sludge lightweight aggregate and waterworks sludge lightweight aggregate). The test results show that the ultimate bond strength increased with the increase of concrete compressive strength. Moreover, the larger the rib height to the diameter ratio ($h/d_b$) of the deformed steel bars is, the greater the ultimate bond stress is. In addition, the suggestion value of the CEB-FIP Model Code to the LWAC specimen's ultimate bond stress is more conservative than that of the normal weight concrete.