• 제목/요약/키워드: Concrete Pumping

검색결과 74건 처리시간 0.023초

Physical Properties of 50MPa and 80MPa Ternary High Strength Concretes before and after Concrete Pumping

  • Lee, Bum-Sik;Kim, Seong-Deok;Jun, Myoung-Hoon;Park, Sung-Sik;Park, Su-Hee;Jung, Sang-Jin
    • 한국건축시공학회지
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    • 제12권4호
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    • pp.451-459
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    • 2012
  • At the Korea Land and Housing Corporation(LH), concretes with high design strength of 50 MPa and 80 MPa that are composed only of ordinary Portland cement, blast furnace slag, and fly ash are developed. To determine whether the developed high strength concretes have the same properties when they are produced in batch plant(B/P) condition in the ready mixed concrete plant, and as existing high strength concretes, field tests are performed and material properties are evaluated. To investigate the material properties of the high strength concretes before and after pumping, compressive strength, flowability, air content, hydration temperature, pumping and compactability are evaluated. In field tests, before and after pumping, flowability satisfied the relevant criteria. In terms of air content, while it was slightly decreased after pumping, it satisfied the requirements. Hydration temperature criteria were satisfied, and compactability was excellent as well. The study found that the developed ternary high strength concretes have the same properties as existing high strength concretes. They can also be useful for the construction of high-rise buildings, as they are economical.

콘크리트 규격 및 압송압에 따른 마찰계수 변화경향에 대한 실험적 연구 (The Experimental Study on the Coefficient of Friction Change Tendency which It Follows in Kinds of Concrete Strength and Pumping Pressure Grade)

  • 권해원;배연기;이재삼;김석일;김현섭;이종서
    • 한국건축시공학회:학술대회논문집
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    • 한국건축시공학회 2009년도 춘계 학술논문 발표대회 산업계
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    • pp.69-73
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    • 2009
  • Plan of concrete pumpability test or the theoretical character knowledge in the mechanic is become accomplished with character. But the character knowledge of the concrete is not considered appropriately, The theoretical background and assumed fact is a little different representative characteristic of the concrete. Concrete pumping experiment result it leads consequently and is produced the coefficient of friction which in concrete type and sending in more pressure it follows changes must grasp the tendency which. But until currently the majority experiment and research did not pass by this process. Grasps the coefficient of friction change tendency which it follows in concrete type and when pumping concrete more pressure data fundamentally from the experimental research which it sees consequently under providing the man with underdeveloped genital organ.

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콘크리트 충전 강관 기둥의 시공에 관한 연구 (Mock-up Tests of Concrete Filled Steel Tubular Columns)

  • 이덕찬;최진만;이도헌;김훈;김진철;박연동
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 1996년도 봄 학술발표회 논문집
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    • pp.382-387
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    • 1996
  • Three concrete filled steel tubular columns with six inner diaphrams are constructed and tested under field conditions. The size and shape of three columns are exactly same. The cross section is $40\times40cm$, and the height is 9m. Each column is constructed with normal concrete, CFST concrete, and high flowing concrete, respectively. Concrete is pumped into bottom parts of steel tubular columns from a concrete pump on the ground. Test data indicate that the slump flow of the concrete place in the top of the column is lower than that of the concrete before pumping by about 10~20cm. Slump flow loss of high flowing concrete caused by pumping is high compared to the other concretes. Concrete pump pressure of high flowing concrete is somewhat higher than that of CFST concrete.

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콘크리트펌프 유압실린더의 충진율 모델 제안 (Suggestion of a Model for Filling Coefficient of Hydraulic Cylinder in Concrete Pump)

  • 박찬규;장경필;정재홍;권승희
    • 한국건설순환자원학회논문집
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    • 제4권2호
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    • pp.195-202
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    • 2016
  • 콘크리트의 펌핑에는 일반적으로 피스톤 펌프를 많이 사용한다. 충진율은 피스톤 펌프의 실린더 부피와 실린더 내에 채워지는 콘크리트의 부피비를 의미한다. 따라서 콘크리트 펌핑에서 토출량과 펌핑 효율에 직접적으로 영향을 미치는 인자라고 할 수 있다. 하지만 아직까지 이에 대한 정확한 분석은 이루어지지 않고 있다. 이 연구에서는 기존에 수행된 350m와 548m 수평배관 펌핑 실험 데이터를 바탕으로 콘크리트의 유동특성, 토출량, 그리고 스트로크 시간과 콘크리트펌프 충진율과의 관계를 파악하였다. 또한 콘크리트의 유동특성과 스트로크 시간으로부터 충진율을 계산할 수 있는 모델을 제안하였다.

Evaluation criteria for filling performance of high-flowing concrete using steel-concrete panel

  • Dong Kyu Lee;Jae Seon Kim;Myoung Sung Choi
    • Advances in concrete construction
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    • 제16권5호
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    • pp.231-241
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    • 2023
  • The purpose of this study was to evaluate the practical application of high-flowing concrete for a steel-concrete panel (SCP) module for a liquefied natural gas (LNG) storage tank. We evaluated the physical properties and filling performance of the developed concrete for the SCP module. First, slump tests were performed to evaluate the performance of the proposed standards for the filling tests. All the concrete mixes showed satisfactory performance. Based on the results of the previous study, the reliability of the required time measured using the T500 test and the rheometer results measured before and after pumping was 0.94, indicating that segregation and blocking should not occur. L-box and U-box tests were conducted before and after pumping. All the recommended standards showed satisfactory performance. The SCP structural module for LNG storage tanks was fabricated to a full scale to evaluate its practical application at the final site. Satisfactory filling performance was confirmed for all the specimens.

A Study on the Optimum Mix Proportion of the Mass Concrete Designed as Massive and Deep Structure

  • Kwon Yeong-Ho;Lee Hwa-Jin
    • 콘크리트학회논문집
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    • 제17권2호
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    • pp.293-302
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    • 2005
  • This study describes data from determination of the optimum mix proportion and site application of the mass concrete placed in bottom slab and side wall having a large depth and section as main structures of LNG in-ground tank. This concrete requires low heat hydration, excellent balance between workability and consistency because concreting work of LNG in-ground tank is usually classified by under-pumping, adaptation of longer vertical and horizontal pumping line than ordinary pumping condition. For this purpose, low heat Portland cement and lime stone powder as cementitious materials are selected and design factors including unit cement and water content, water-binder ratio, fine aggregate ratio and adiabatic temperature rising are tested in the laboratory and batch plant. As experimental results, the optimum unit cement and water content are selected under $270kg/m^3$ and $l55{\~}l60 kg/m^3$ separately to control adiabatic temperature rising below $30^{\circ}C$ and to improve properties of the fresh and hardened concrete. Also, considering test results of the confined water ratio($\beta$p) and deformable coefficient(Ep), $30\%$ of lime stone powder by cement weight is selected as the optimum replacement ratio. After mix proportions of 5cases are tested and compared the adiabatic temperature rising($Q^{\infty}$, r), tensile and compressive strength, modulus of elasticity, teases satisfied with the required performances are chosen as the optimum mix design proportions of the side wall and bottom slab concrete. $Q^{\infty}$ and r are proved smaller than those of another project. Before application in the site, properties of the fresh concrete and actual mixing time by its ampere load are checked in the batch plant. Based on the results of this study, the optimum mix proportions of the massive concrete are applied successfully to the bottom slab and side wall in LNG in-ground tank.

펌프압송 시 압력변화에 따른 콘크리트 물성변화 규명을 위한 실험적 연구 (An experimental study on the quality variation of concrete caused by high pressure in pumping.)

  • 전성식;김상헌;지석원;서치호;김욱종;이도범
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 2006년도 춘계 학술발표회 논문집(II)
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    • pp.613-616
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    • 2006
  • Development of construction technology and various condition is realized by high-rise buildings and so concrete placing by pressure pump has been developed in with the trend of large-size and high-rise building. So, it is judged that reservation of the basic data for standard of quality control standard Code by the prediction and this to a quality change exact here is urgent. In this study it is going to carry out experimental research for a physical-properties change searching examination of the concrete by the after pressure change factor which does not become hard by the pumping method of construction.

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고압송용 고유동콘크리트 개발을 위한 가압에 따른 굵은골재의 흡수 특성 (Absorption Properties of Coarse Aggregate according to Pressurization for Development of High Fluidity Concrete under High Pressure Pumping)

  • 최연왕;최병걸;오성록
    • 한국구조물진단유지관리공학회 논문집
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    • 제20권3호
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    • pp.122-129
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    • 2016
  • 본 연구에서는 고압송용 고유동콘크리트 개발을 위한 기초적인 연구의 일환으로 펌프압송시 압송관내 콘크리트가 받는 압력을 재현할 수 있는 가압장치를 개발하였다. 이를 통하여 펌프압송할 경우 발생되는 품질변화의 원인 중 압력에 의한 단위수량 감소에 중점을 두어 가압에 따른 콘크리트용 굵은골재의 흡수 특성 및 고유동콘크리트 내부 굵은골재의 흡수 특성을 평가하였으며, 고유동콘크리트의 가압 전 후 압축강도를 평가하였다. 실험결과, 250 bar의 높은 압력이 작용할 경우 부순굵은골재 및 강자갈의 흡수율은 표건 흡수율 이상으로 증가되지 않는 것으로 나타났으며, 경량굵은골재의 흡수율은 표건 흡수율 이상으로 증가되는 것으로 나타났다.

유동화 콘크리트의 현장적용과 품질관리 시스템 구축 (Application and System Establishment on Quality Control of Flowing Concrete)

  • 김규용;길배수;한장현;주지현;박선규;한승구;조성기;김무한
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 1999년도 학회창립 10주년 기념 1999년도 가을 학술발표회 논문집
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    • pp.801-804
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    • 1999
  • The interest in workability and quality control of concrete is increasing as to improve quality of concrete structure according to industrialization. Therefore, it is the aim of this study to evaluate the quality of flowing concrete and systematize quality control by analyzing the data of the quality control of concrete through a basic quality control system for improvement of the concrete in pumping flowing concrete for construction industy.

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