• 제목/요약/키워드: SUPER Concrete

검색결과 291건 처리시간 0.021초

다짐이 필요없는 콘크리트의 역학적 특성에 관한 실험적 연구 (An Experimental Study on the Mechanical Properties of Super- Workable Concrete)

  • 이준구;윤상대;박광수;이성행;배수호
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 1997년도 봄 학술발표회 논문집
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    • pp.177-185
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    • 1997
  • The purpose of this study is to investigate the mechanical properties of super-workable concrete using O.P.C., blast-furnace slag, and fly ash respectively. For this purpose, after determining the optimum mix proportion of super-workable concrete according to unit weight of binder and percentage of fine aggregate respectively, mechanical properties of super-workable concrete such as compressive, tensile and flexural strength as well as elastic modules were tested and analyzed. Also, the mechanical performances of super-workable concrete were compared with those of high-strength concrete with equal mix proportion of concrete. As a result, super-workable concrete have an excellent mobility, placeability, and segregation-resistance, but the strength of super-workable concrete was shown to be somewhat lower than that of high-strength concrete with equal mix proportion of concrete.

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저발연 시멘트를 사용한 초유동 콘크리트의 물성 (The Application of Super-flowing Concrete Using Low Heat Cement)

  • 노재호;한정호;송용순;최이현;천재원
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 1997년도 봄 학술발표회 논문집
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    • pp.649-656
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    • 1997
  • The properties of super-flowing concrete with low heat cement were experimentally investigated and compared with ordinary 25-240-15 concrete with type Vcement. The cement content of super-flowing concrete with the low heat cement was 400 kg/$\textrm{m}^3$. However the hydration heat of super-flowing concrete is relatively lower than that ordinary concrete with type V cement. Also the ability to resist chloride ion penetration of super-flowing concrete with low heat cement is 5 times better than that of the ordinary concrete.

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초유동 콘크리트의 재료특성에 관한 실험적 연구 (An Experimental Research on the Material Properties of Super Flowing Concrete)

  • 김진근;한상훈;박연동;노재호
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 1995년도 가을 학술발표회 논문집
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    • pp.56-62
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    • 1995
  • In this study, the properties of super flowing cocrete containing gly ash were experimentally investigated and compared with those of ordinary concrete. Tests were carried out on five types of super flowing concrete mixes containing fly ash and three types of ordinary concrete mixes without fly ash. Flow test, O-funnel test, box test, Ltype thest and slump test were carried out to obtain the properties for the workability of fresh concrete. Compressime strength, splitting tensile strength, modulus of elasticity. creep and shrinkage test were also obtained as the mechanical properties of hardened concrete. In fresh concrete, it was found that super flowing concrete had excellent workability and flowability compared with ordinary concrete, and the volume ratio of coarse aggregate to concrete volume greatly influenced flowability. Super flowing concrete also had good mechanical properties at both early and late ages with compressive strengths reaching as high as 40 MPa at 28 days. The creep deformation of super flowing concrete investigated were relatively lower than that of ordinary concrete.

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초유동 콘크리트의 제조 및 역학적 특성에 관한 실험적 연구 (An Experimental Study on the Production and Mechanical Properties of Super-Workable Concrete)

  • 배수호;윤상대;이대형
    • 한국농공학회지
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    • 제40권6호
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    • pp.104-113
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    • 1998
  • The purpose of this experimental research is to produce the super-workable concrete using ordinary portland cement, blast-furnace slag lowder, and fly ash respectively, and investigate mechanical properties of super-workable concrete. For this purpose, after production of super-workable concrete for different unit weights of binder and percentages of fine aggregate, optimum mixing proportion of them was determined, and then mechanical properties of super-workable concrete such as static modulud of elasticity as well as compressive, tensile and flexural strength were tested and analyzed. Also, the mechanical performances of super-workable concrete were compared with those of high-strength concrete has an excellent mobility, compactability and segregation-resistance, but the strength of super-workable concrete is somewhat lower than that of high-strength concrete with equal mixing proportions of concrete.

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응결시간차를 활용한 매스콘크리트의 수화열 조정공법 (A Method on the Control of Hydration Heat of Mass Concrete Considering the Difference of Setting Time)

  • 심보길;윤치환;한민철;김기철;오선교;한천구
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 2001년도 가을 학술발표회 논문집
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    • pp.379-384
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    • 2001
  • This Paper Presents field application test results of mass concrete using super retarding agent. The field test was carried out at mat foundation(thickness 1m) of newly constructed information center of Chongju university. Placing lift composed of 2 layers, and each layer is 50cm. Fly ash and flowing method is also applied. Difference of setting time of concrete between with super retarding agent and without super retarding agent is considered. Concrete without super retarding agent is placed at upper layer and with super retarding agent at lower layer According to test results, the reducing method of hydration heat considering difference of setting time with super retarding agent can reduce the highest temperature about 3~4$^{\circ}C$, and delay the peak time about 3~4days. Compressive strength using super retarding agent is somewhat higher than that of normal concrete. Accordingly, super retarding agent does not affect the strength development.

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고성능 콘크리트 개발에 관한 실험적 연구(제2보, 초유동 콘크리트의 기초물성) (Experimental Study on the Development of High-Performance Concrete (Properties of Super-flowing Concrete))

  • 조일호;한정호;정재동
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 1993년도 가을 학술발표회 논문집
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    • pp.51-56
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    • 1993
  • This is a part a study on the development of High-Performance Concrete ; about experimental results from several test methods to estimate workability in fresh concrete and influences of concrete mix design that affects properties of super-flowing concrete. Super-flowing concrete can be filled in a formwork without any vibration because of its excellent workability of passing narrow space and filling complicated shaped mold, new test methods should be used to estimate the workability and rhelogy in super-flowing concrete instead of slump test method in conventional concrete.

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120, 180 MPa 강섬유 보강 초고성능 콘크리트에 정착된 확대머리철근의 정착강도 (Anchorage Strength of Headed Bars in Steel Fiber-Reinforced UHPC of 120 and 180 MPa)

  • 심혜정;천성철;최석환
    • 콘크리트학회논문집
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    • 제28권3호
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    • pp.365-373
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    • 2016
  • 강섬유 보강 초고성능콘크리트(SUPER Concrete)는 일반 콘크리트에 비해 높은 압축강도와 인장강도를 지닌다. 이러한 특성으로 SUPER Concrete로 제작된 부재는 단면을 크게 줄일 수 있고, 확대머리철근의 정착강도가 향상될 것으로 기대된다. 이 연구에서는 120 MPa, 180 MPa SUPER Concrete로 제작된 외부 보-기둥 접합부에 $4d_b$, $6d_b$의 정착길이를 갖는 확대머리철근의 정착 성능을 평가하였다. 모든 실험체에서 600 MPa 이상의 실제 항복강도가 발현된 후 일부 실험체에서 측면파열파괴가 발생되었다. 확대머리철근의 정착강도가 매우 높아 철근이 파단되는 경우도 있었다. 설계기준강도 120 MPa 이상 SUPER Concrete에 정착된 확대머리철근은 $4d_b$의 짧은 정착길이로 콘크리트구조기준에서 허용하는 철근의 최대 설계기준강도 600 MPa를 발현할 수 있는 것으로 평가되었다. 기존에 개발된 일반 콘크리트에 정착된 확대머리철근의 측면파열파괴강도 평가식과 현행 콘크리트구조 기준의 확대머리철근 정착길이 설계식은 실험값을 과소평가하였다. 일반콘크리트에서 개발된 평가식은 SUPER Concrete의 높은 인장강도 특성을 반영하지 못하기 때문으로 분석된다. 확대머리철근 정착강도를 $(f_{ck})^{\alpha}$에 비례한다고 가정하고 실험결과를 회귀분석하여, SUPER Concrete 압축강도의 0.14승에 비례하는 정착강도 평가식이 개발되었다. 40개 실험 자료에 대한 [실험값]/[예측 값]의 평균은 1.01, 변동계수는 5%였다.

초유동 콘크리트의 유동 성능에 미치는 배합요인의 영향 (Effect of Mix Proportion on the Flowing Characteristics of Super-flowing Concrete)

  • 노재호;한정호;백명종;이보근;박기청
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 1994년도 가을 학술발표회 논문집
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    • pp.115-120
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    • 1994
  • Recently super-flowing concrete has been developed and used in many construction sites in Japan. It is believed that super-flowing concrete will change the construction method and contribute to the durability of concrete structures. In this study the effect of mix proportion on the flowing characteristics of super-flowing concrete was investigated to establish the mix design method. From the result we have found that self-compactability of super-flowing concrete was greatly affected by the unit gravel volume and paste/gravel volume ratio. Therefore the two parameters can be used in mix design of super flowing concrete.

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초유동콘크리트의 유동특성에 관한 실험적 연구 (An Experimental Study on the Flowability of Super Flowing Concrete)

  • 권영호;이상수;박연동;김진근;박칠림
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 1995년도 가을 학술발표회 논문집
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    • pp.1-7
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    • 1995
  • In this paper, we decribed the basic elements required for the practical usage of super flowing concrete. The flowability and filingability of fresh concrete was measured by using six different testing methods. Also, two actual size members were used for investigating characteristics of the hardened concrete through variious experiments. As the result of the experimentation, the developed super flowing concrete shown high flowability and fillingability good enough for the requirement. Furthermore, inner uniformity of the no-vibrated concrete was verified by testing distribution of aggregates and core cylinders. Therefore, quality control and workability of concrete can be secured by using the super flowing concrete even without vibrating However, it ha been felt that development of easy evaluation methods for the super flowing concrete is in need.

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초유동 콘크리트의 2차제품 적용에 관한 연구 (Application of the Pre-cast Concrete of the Super Flowing Concrete)

  • 권영호;이상수;원철;박칠림
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 1997년도 봄 학술발표회 논문집
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    • pp.285-291
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    • 1997
  • This study is the experimental results on the applicability of the super flowing concrete, which is the pre-cast concrete, to various cases. The primary purpose of this study is to verify the demolding strength, the handling strength of the super flowing concrete at various curing conditions, and the site quality control of the DWS (Daewoo Multi-Room Modular Construction System). From the experimental works, required strength and curing cycles are satisfied. Furthermore site quality control details and quality of the pre-cast concrete using the super flowing concrete are obtained. From now on, this study may suggest how to apply the super flowing concrete for common circumstance.

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