• 제목/요약/키워드: 저열 포틀랜드 시멘트

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벨라이트계 혼합 결합재의 수화열 특성에 관한 연구 (Study on Hydration Heat of Blended Belite Binder)

  • 이근주;조재우;정상화;김장호
    • 콘크리트학회논문집
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    • 제23권2호
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    • pp.145-150
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    • 2011
  • 전국적으로 토목 및 건축 구조물의 대단위 공사 및 정비 사업이 발족 및 추진되어 부재 크기가 큰 매스 콘크리트 구조물이 많이 건설되고 있다. 대규모 콘크리트 구조물의 콘크리트 매트릭스 내 높은 수화열 발생은 콘크리트의 품질 및 시공 기간을 좌우하는 가장 중요한 요인이 되고 있다. 이로 인해 발생되는 내부 균열이 콘크리트의 내구성, 수밀성 및 강도를 저하 시키게 된다. 벨라이트계 저열 포틀랜드 시멘트와 산업부산물을 이용한 수화열을 저감시키는 방법으로 이 연구에서는 고로 슬래그 또는 플라이애쉬를 7단계로 치환한 2성 분계 결합재와 4단계로 치환한 3성 분계 결합재를 사용하였고, 혼화재의 치환율 변화가 재령에 따른 수화 발열량, 강도 및 SEM, XRD 등의 기초 물성에 미치는 영향을 비교 분석하였다. 플라이애쉬가 치환된 2성 분계 결합재의 28일 누적 수화열은 플라이애쉬 함유량의 증가함에 따른 높은 수화열 저감 효과를 보여주며, 고로 슬래그가 치환된 2성 분계 결합재의 28일 누적 수화열은 고로 슬래그 치환율이 증가함에 따라 감소하지만 수화열 감소 효과는 높은 치환율 대비 낮은 결과를 나타내었다. 3성 분계 결합재의 28일 누적 수화열의 경우 플라이애쉬 치환율이 높아짐에 따라 낮은 수화열 결과를 보여주며 특히 40% 플라이애쉬 및 30% 고로 슬래그 결합재는 벨라이트계 저열 포틀랜드 시멘트 대비 50%의 저열 효과를 보여주었다. 연구 결과를 통해 수화열 발생이 낮고 시공 가능한 압축강도를 가진 벨라이트계 혼합 결합재를 사용하여 콘크리트 내 온도 상승이 감소된 것을 보여주었다.

저열 포틀랜드(4종)시멘트를 사용한 고유동, 고강도콘크리트에 관한 연구 (A Study on the Properties of High Performance Concrete Using Low Heat Portland(Type IV) Cement)

  • 최광일;김기수;하재담;김동석;이순기;이동윤
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 1997년도 가을 학술발표회 논문집
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    • pp.422-429
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    • 1997
  • In recent years, concrete construction have become larger and higher and are demanding high performance concrete with lower heat to prevent thermal cracking, far greater workability, high strength and durability. Application of low heat portland(Type IV) cement for the high performance concrete is the best solution to satisfied those requirements. Here are explained the basic properties of fresh concrete as well as hardened concrete of high performance concrete using low that portland cement.

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저열 포틀랜드 시멘트 콘크리트의 고강도 영역에서의 강도발현 특성 (Strength Development of Low Heat Portland Cement Concrete in High Strength Range)

  • 하재담;엄태선;이종열;권영호
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 2005년도 봄학술 발표회 논문집(II)
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    • pp.353-356
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    • 2005
  • Strength development of low heat portland cement(Type IV) concrete in high strength range is tested. In this study strength development according to water-binder ratio, strength development according to age, effect of fly ash and super plasticizer are tested. This study tests effect of low heat portland cement in high strength range concrete and provide guide line concrete mix design for later study and/or construction.

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마이크로파를 이용한 저열 포틀랜드(4종)시멘트 모르터의 조기강도 추정에 관한 실험적 연구 (An Experimental Study on the Strength Estimation of Belite Cement Mortar by Microwave Heating)

  • 김민석;정근호;이영도;정재영;정상진
    • 한국건축시공학회지
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    • 제1권2호
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    • pp.179-184
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    • 2001
  • The most recent building trend is going large, high rise, high strength as overlarge project is developing in domestic construction business. Belite cement has properties like low heat, excellent long term strength, and durability without admixture(fly ash, silica fume). so, Beilte cement is suitable for mass structure which is needed high strength, high fluidity and low heat property. This study is to examine the possibility if site adoption microwave-use early strength estimation method. Based on the existed study related the portland cement, the interrelation between Belite cement and microwave-use early strength estimation method is required. In this study, interrelation between mortar and Evaluating strength estimation method is investigated before the concrete experiment.

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저열 포틀랜드(벨라이트)시멘트 콘크리트의 특성 (Properties of Low Heat Portland(Belite Rich) Cement Concrete)

  • 하재담;김기수;김동석;구본창;조계홍;이동윤
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 1998년도 가을 학술발표회 논문집(I)
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    • pp.66-71
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    • 1998
  • Recently, it has been increased to construct massive concrete structures, like under-ground structure, offshore structure etc., ie. concrete construction have become larger and higher and are demanding lower heat concrete to prevent thermal cracking. It has been progressed to replace cements with fly-ash and slag to lower heat of hydration, but it is hard to control quality of the mineral admixtures in stage of adjusting of real construction. Application of low heat portland(Belite Rich) cement for the mass concrete is the best solution to satisfied those requirements. Here are explained the basic properties of fresh concrete as well as hardened concrete of using low heat portland cement(LHPC). Also, we compare the results of adiabatic temperature rise test using LHPC and OPC.

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저열 포틀랜드(4종)시멘트 모르터의 마이크로파를 이용한 조기강도 추정에 관한 실험적 연구 (Experimental Estimation of the Early Strength of Belite Cement Mortar Using Microwave)

  • 김민석;박재한;정근호;이종균;이영도;정상진
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 2001년도 가을 학술발표회 논문집
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    • pp.1077-1082
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    • 2001
  • The most recent building trend is going large, high rise, high strength as overlarge project is developing in domestic construction business. Belite cement has properties like low heat, excellent long term strength, and durability without admixture(fly ash, silica fume). so, Belite cement is suitable for mass structure which is needed high strength, high fluidity and low heat property. This study is to examine the possibility of site adoption microwave-use early strength estimation method. Based on the existed study related the portland cement, the interrelation between Belite cement and microwave-use early strength estimation method is required. In this study, interrelation between mortar and Evaluating strength estimation method is investigated before the concrete experiment.

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저열 포틀랜드 시멘트 적용을 통한 SRC 교각 온도균열 제어 (Thermal Crack Control of SRC Pier Using Low-Heat Portland Cement)

  • 김태홍;하재담;유재상;이종열
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 2001년도 가을 학술발표회 논문집
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    • pp.297-302
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    • 2001
  • SRC pier at KTE 6-1 construction area is a very important structure. Precise control of quality is needed. This pier has 3.50m$\times$3.73m section and 38.20m length. So this structure must be treated as mass concrete and thermal crack caused by hydration heat should be controled. In this project belite cement concrete is used to control the thermal crack. As a result of adapting belite cement concrete perfect control is achieved. Finally, hydration heat FEM analysis of horizontal element is executed for Ordinary Portland Cement concrete and belite cement concrete. In comparison of two results, it is confirmed that using low heat portland cement concrete is necessary.

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저열 포틀랜드 시멘트를 사용한 고유동콘크리트의 사용재료 및 배합 변동에 따른 특성 평가 (The Effect on the Properties of High Flowing Concrete Using Low Heat Portland Cement by Material and Mixing Variations)

  • 하재담;김태홍;유재상;이종열;권영호
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 2001년도 가을 학술발표회 논문집
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    • pp.303-308
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    • 2001
  • Recently, concrete structures have become larger and higher and are demanding high performance concrete with lower heat to prevent thermal cracking, far greater workability, high strength and durability, Application of low heat portland(Type IV) cement for the high performance concrete is the best solution to satisfied those requirements. Here are explained the effect on the properties of high flowing concrete using low heat portland cement by material and mixing variations. Variables for sensitivity test were selected items like finess modulus of aggregates, particle size of limestone powder, unit water, superplasticizer, viscosity agent and concrete temperature. The results of this study were be applied to slurry wall of #215 and #216 of underground LNG tank in Inchon.

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플라이 애쉬 치환율에 따른 저열 포틀랜드 시멘트 콘크리트의 고강도 영역에서의 강도발현 특성 (Strength Development of Low Heat Portland Cement Concrete according of Substitution of Fly-ash in High Strength Range)

  • 김태홍;하재담;엄태선;이종열;권영호
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 2005년도 추계 학술발표회 제17권2호
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    • pp.603-606
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    • 2005
  • Strength development of low heat portland cement(Type IV) concrete according of addition of fly-ash in high strength range is tested. In this study strength development according to water-binder ratio, strength development according to age, effect of fly ash are tested. This study tests effect of low heat portland cement in high strength range concrete and provide guide line concrete mix design for later study and construction.

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저열 포틀랜드 시멘트를 사용한 댐 콘크리트의 특성에 관한 연구 (Study on the Properties of Dam Concrete Using Low Heat Portland Cement)

  • 손영준;하재담;엄태선;이종열;김태홍
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 2006년도 춘계 학술발표회 논문집(II)
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    • pp.445-448
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    • 2006
  • In order to control the temperature crack of massive dam concrete, the selection of appropriate materials like binder, aggregates etc., is essential. To select the optimal mix proportion, ordinary portland cement(Type I) plus 25% of fly ash and low heat portland cement(Type IV) are used as binder, and 80mm of coarse aggregates are used to reduce the amount of binder and compare the compressive strength, hydration temperature and crack index. The results of this study are as following. 1. The strength of Type IV cement is advantageous on the long-term age. 2. According to the temperature measured on mock-up$(1.5m{\times}1.5m{\times}1.5m)$, and realized the thermal analysis, the Type IV cement carried out advantageous to control the thermal crack.

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