• 제목/요약/키워드: fresh콘크리트

검색결과 502건 처리시간 0.029초

점소성 유동 입자법에 의한 굳지 않은 콘크리트의 유동해석 모델 (Model for Flow Analysis of Fresh Concrete Using Particle Method with Visco-Plastic Flow Formulation)

  • 조창근;김화중;최열
    • 콘크리트학회논문집
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    • 제20권3호
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    • pp.317-323
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    • 2008
  • 본 연구에서는 굳지 않은 콘크리트 및 유동 콘크리트의 흐름 거동에 관한 해석 시뮬레이션 모델의 개발에 관한 것으로, 입자법의 일종인 MPS법 (moving particle semi-implicit method)을 적용하였다. 콘크리트의 유동 현상을 점소성의 흐름 문제로 고려하였으며, 콘크리트 입자의 운동에 관한 지배방정식은 라그랑지 정식화의 Navier-Stokes 방정식과 질량보존의 법칙에 기초하도록 하였다. 굳지 않은 콘크리트의 점소성 흐름 구성관계의 정식화를 위하여 콘크리트는 부동 상태인 경우 고점성체의 유체로, 유동상태인 경우 항복응력 이후 점소성체의 유체로 모델링하였다. 개발된 모델을 이용하여 L-형 박스의 콘크리트 유동 시험에 대해 시뮬레이션 하였으며, 그 결과 예측된 흐름량은 실험의 흐름량과 잘 일치하는 것으로 나타났다. 개발된 입자법의 해석 모델은 점소성 유체의 운동현상에 기초하여 정식화 되어 콘크리트 입자의 유동 및 운동 현상을 잘 묘사해 주는 것으로 평가된다.

굳지않은 모르타르의 레올로지 성질에 미치는 간극수압의 영향 (Influence of Pore Wter Pessure on Rheological Properties of Fresh Mortar)

  • 이건철;이세현;한천구
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 2006년도 추계 학술발표회 논문집
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    • pp.793-796
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    • 2006
  • In this study, the rheological properties of fresh concrete of fresh mortar and concrete were investigated experimentally by shear box test. The pore water pressure in fresh mortar was measured as an influence factor of shear deformation of fresh mortar. As the result, it was clarified that the rheological properties is affected by the pore water pressure in fresh mortar and, the correcting method of shear stress in case of shear box test was obtained.

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굳지않은 포러스콘크리트의 품질관리를 위한 실험적 연구 (An Experimental Study on the Quality Control of Fresh Porous Concrete)

  • 이성일;장종호;김재환;강석표;백용관;김무한
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 2002년도 봄 학술발표회 논문집
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    • pp.705-710
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    • 2002
  • Recently, there has been for a number of reasons growing interest in the use of porous concrete, and it is used as an ecological material. But, because the valuation methods of the quality on the fresh porous concrete aren't established up till now, it is difficult that the harden porous concrete is made sure of its required quality. This study is to present the measurement method of the void ratio on the fresh porous concrete and to analyze the influence of water-cement ratio and vibrating time on the binder content covered a coarse aggregate. Results of this study were shown as follows; The measurement methods of the void ratio and aggregate-binder weight ratio on the fresh porous concrete can be useful as data for the quality control of fresh porous concrete.

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Fresh 콘크리트의 초기 강도 증가를 고려한 진동규준치 제안 (Suggestion of Vibration Criteria for Fresh Concrete Considering Early Strength Increase)

  • 박선준;박연수;강성후;김홍기;김응록
    • 한국소음진동공학회논문집
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    • 제12권6호
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    • pp.453-460
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    • 2002
  • In this paper, vibration criteria for fresh concrete are suggested considering relationship of strength and ages of concrete. Vibration criteria of fresh concrete subjected to construction vibration are not to be certain in abroad countries without question within a country. Before 12 hours cured, vibration criterion is suggested 0.25 cm/s. Used 4.0 cm/s by vibration criterion after 28 days. And the interval extent used relation with strength and ages of concrete. Vibration criteria proposed in this paper are thought may satisfy properties of fresh concrete as well as generally used those in domestic. Also, the actual ground vibrations due to pile driving have been measured, and data are analyze using the nitration equation applying to reliability index.

초유동 콘크리트의 개발에 관한 기초적 연구 -제 2보 : Fresh 콘크리트의 성능평가 - (A Fundamental Study on development of Ultra-Flow Concrete - part2.The Preformance estimation of Fresh Concrete -)

  • 김화중;김재훈;박정민;최신호;이승조;김태곤
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 1995년도 봄 학술발표회 논문집
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    • pp.48-53
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    • 1995
  • Recently, work of construction industry is not enough to do in tamping because of a lack of expert, advanced-age of worker, increase of structure of high-dengity arrangment and machanization of concrete pumping method Accordingly it is required for high-qualuily concrete with excellent flowability, Self-placeability and regregation registance. In this point of view, this study is investigated for requiremend properties of ultar-flow concrete using dimestic material as for development of Ultra-Flow concrete in the side of material

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콘크리트의 유동성에 미치는 타설진동의 영향 (Effects of Internal Vibration on Flowability of Fresh Concrete)

  • 최수경
    • 콘크리트학회논문집
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    • 제12권3호
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    • pp.77-85
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    • 2000
  • Various concretes are used for construction works depending on the types of structure, building element and method of construction. An internal vibration work is one of the important processes for adequately pouring various concrete into a certain form. This study was undertaken to find out the effects of internal vibration on flowability of fresh concrete by concrete flow test under eight conditions of vibration. Presumable equation models also were created to show all vibration effects without regard to kinds of concrete. As the results of this study, the degree of vibration effects were varied according to the properties of concrete. Acceleration amplitude of vibration that applied to fresh concrete was effective value of the properties of vibration in a viewpoint of flowability. Moreover, This research presents the presumed equation models including variables created by acceleration amplitude and measuring value of vibrated concrete flow test. These models are presumable methods of vibration effects regardless of kinds of concrete.