• Title/Summary/Keyword: high flowing

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Prediction of the Compressive Strength of High Flowing Concrete by Maturity (적산온도에 의한 고유동콘크리트의 압축강도 예측)

  • 길배수;한장현;김규용;권영진;남재현;김무한
    • Proceedings of the Korea Concrete Institute Conference
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    • 1998.10a
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    • pp.281-286
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    • 1998
  • The aim of this study is to compare the development of compressive strength of high-Flowing concrete with maturity and to investigate the applicability of strength prediction models of concrete. An experiment was attempted on the high-flowing concrete mixes using Ordinary portland cement, High belite cement, Blast furance slage cement and replaced Fly-ash of 30% by weight of Ordinary portland cement, the water-binder ratios of mixes being 0.35 and the curing temperatures being 30, 20, 10, 5$^{\circ}C$. Test results of mixes are statistically analyzed to infer the correlation coefficient between the maturity and the compressive strength of high-flowing concrete.

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Hydration Heat Properties of High Flowing Self-Compacting Concrete with Normal Strength (보통강도 고유동 자기충전 콘크리트의 수화발열 특성)

  • Choi, Yun-Wang;Kim, Byoung-Kwon;Lee, Jae-Nam;Ryu, Deug-Hyun;Song, Yong-Kyu;Jung, Woo-Yong
    • Proceedings of the Korea Concrete Institute Conference
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    • 2008.11a
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    • pp.497-500
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    • 2008
  • This research carries out experiments for hydration exothermic rate and adiabatic temperature rise of concrete to examine the characteristics of the hydration heat of high flowing self-compacting concrete with a normal strength. As a result of the hydration exothermic rate experiment, the high flowing self-compacting concrete that used Lime stone powder and fly ash as polymers shows that its hydration heat amount reduces due to the reduction of unit cement. The result measured the adiabatic temperature rise of concrete presents that high flowing self-compacting concrete having lots of binder contents has a good performance in temperature reduction due to the effect of polymer and that triple adding high flowing self-compacting concrete has a similar temperature rise speed with conventional concrete. As a result of the research, high flowing self-compacting concrete shows a better temperature reduction performance for the binder content per unit than conventional concrete. In addition, it is judged that triple adding high flowing self-compacting concrete with a specified concrete strength 30 MPa is more beneficial in temperature reduction and early hydration heat than double adding high flowing self-compacting concrete.

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An Experimental Study on the Fludity of High Flowing Concrete according to the Fineness Modulus of Fine Aggregate (세골재의 조립율에 따른 고유동콘크리트의 유동특성에 관한 실험적 연구)

  • 박유신;강석표;조성현;최세진;김규용;김무한
    • Proceedings of the Korea Concrete Institute Conference
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    • 1997.10a
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    • pp.385-390
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    • 1997
  • In the mixing proportion of high flowing concrete we have to use quantity of power such as cement and superplasticizer, and increase the proportion of fine aggregate more than that of plain concrete to increase flowability and segregation resistance. Therefore, the fresh state of high flowing concrete is largely affected by superplasticizer and change of grade the percentage of surface water. This study aims at development of self-filling up high flowing concrete without compaction, in case of using the fine aggregate of standard grade range, by examination on the influence of fresh state of high flowing concrete, and by understanding influence on various fluidity such as flowability, reinforcement passibility, fillingability, segregation resistance.

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A Study on the Drying Shrinkage and Carbonation High Flowing Concrete using Viscosity Agent (증점제를 사용한 고유동콘크리트의 건조수축 및 중성화에 관한 연구)

  • Kwon, Young-Jin
    • Journal of the Korea Institute of Building Construction
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    • v.3 no.3
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    • pp.121-126
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    • 2003
  • This study investigated about several mix factors came up to drying shrinkage and carbonation of high flowing concrete using viscosity. The results are as follows; Drying shrinkage ratio of high flowing concrete using viscosity showed higher for early age, but lower than normal concrete as long age. Also, drying shrinkage ratio and reduction ratio of mass showed higher and relative dynamic modulus of elasticty showed lower as W/C was higher generally. And in case of high flowing concrete using viscosity, carbonation wasn't confirmed without the kinds of cement and viscosity except 50C.

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

  • 조일호;한정호;정재동
    • Proceedings of the Korea Concrete Institute Conference
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    • 1993.10a
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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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Setting and Compressive Strength Development of Hihg Flowing Concrete (고유동 콘크리트의 응결특성과 압축강도 발현)

  • 권영진;김무한
    • Proceedings of the Korea Concrete Institute Conference
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    • 1995.10a
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    • pp.8-13
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    • 1995
  • High flowing concrete has been made using a combination of different cementitious material. The use of supplementary cementitious material like ground granulated slag is not only interesting from an economical point of view but also from a mechanical and rheological point of view. In the case of high strength concrete, relation between the maturity and compressive strength development of high strength concrete is aproximated by appling gompertz curve and suggested new estimating method. It is the aim of this study to analysis the effect of different types of mineral fine power on the setting and compressive strength development of high flowing concrete.

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A Study on the factors of Quality variation for High Flowing Concrete in Site (고유동 콘크리트의 품질변동 요인에 관한 연구)

  • Kwon Yeong-Ho;Lee Hyun-Ho;Lee Hwa-Jin;Ha Jae-Dam
    • Proceedings of the Korea Concrete Institute Conference
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    • 2004.11a
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    • pp.743-746
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    • 2004
  • This research investigates experimentally an effect on the properties of the high flowing concrete according to variations of concrete materials and site conditions. Variations of sensitivity test are selected items as followings; (1)Concrete temperature, (2)Unit water(Surface moisture of fine aggregate), (3)Fineness modulus of fine aggregate, (4)Addition ratio of high-range water reducing agent. And fresh conditions of the high flowing concrete should be satisfied with required range including slump flow$(65{\pm}5cm)$, 50cm reaching time of slump flow$(4\~10sec)$, V-box flowing time$(10\~20sec)$, U-box height(min.300mm) and air content$(4{\pm}1\%)$. As results of sensitivity test, material variations and site conditions should be satisfied with the range as followings; (1)Concrete temperature is $10\~20^{\circ}C$ (below $30^{\circ}C$), (2)Surface moisture of fine aggregate is within ${\pm}0.6\%$, (3)Fineness modulus of fine aggregate is $2.6{\pm}0.2$ and (4)addition ratio of high range water reducing agent is within $1\%$ considered flow-ability, self-compaction and segregation resistance of the high flowing concrete.

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시공성 향상을 위한 고유동 콘크리트 배합모델 개발에 관한 실험적 연구

  • 손유신;윤영수;송영철;우상균
    • Proceedings of the Korea Concrete Institute Conference
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    • 2000.04a
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    • pp.66-71
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    • 2000
  • Recently, great efforts and investment have been made in order to achieve economical production by applying new methods like minimization of man-power into construction field. Therefore in this study, we have been focused on the development and practical using of high of high flowing concrete with fly ash, superplasticizer and viscocity agent, also we find out the optimum mix proportions to accomplish good wuality high flowing concrete. The results of this study show that high flowing concrete with the ratio of fly ash replacement of 20%, viscosity agent of 300g/㎥ and superplsticizer 2.0%(C$\times$%) in W/B of 35, 45% has better performance than the high flowing concrete without fly ash replacement

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A Study on the High-Flowing Concrete with Low Unit Weight of Cement

  • Si Woo Lee;Hong Shik Choi;Sang Chel Kim;Gweon Heo
    • The Korean Journal of Ceramics
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    • v.6 no.3
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    • pp.318-321
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    • 2000
  • Most compressive strengths commonly used in the construction field are in a range of 240 to 300 kgf/$\textrm{cm}^2$ at 28 days. To get this rage of strengths, however, high-flowing concrete requires cementitious binders more than 400 to 450 kg/$\textrm{cm}^2$ for preventing segregation and sedimentation of aggregates. This amount of cementitious binder generates a large emission of excessive hydration heat, which may consequently induce harmful cracks in concrete structure. In order to reduce excessive hydration heat, thus, this paper aims at fabricating a high-flowing concrete under the condition that cement content is kept as low as 350kg/$\textrm{cm}^3$ by using viscose agents. In a parametric study, effects of cement types such as a ternary blended cement and Type V on he physical characteristics of high-flowing concrete were evaluated. In addition, the influence of viscosity was also investigated by applying two different viscose agents, one in a range of 6,000 to 10,000 cps and the others of 10,000 to 14,000 cps. In terms of chemical admixtures used in concrete mixture, the superplasticizer was Sulfonated Melamine-Formaldehyde Condensate with about 30,000 of molecular weight, and main component of viscose agent was HPMC (Hydroxy Propyl Methyl Cellulose). Slump flow was fixed at 50cm with different dosages of superplasticizer in weight.

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The Experience Study on the Floating Properties of High Flow Concrete on volum of Coarse Aggregate used Admixture (굵은골재 체적에 따른 고유동콘크리트의 유동특성에 관한 실험적 연구)

  • Choi, Sung-Woo;Kim, Ho-So;Baek, Chul-Woo;Ban, Seong-Soo;Ryu, Deuk-Hyun
    • Proceedings of the Korea Concrete Institute Conference
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    • 2004.11a
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    • pp.751-754
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    • 2004
  • There are many factors that affect on the flowing properties of high flowing concrete(HFC), which are fluidity, compactibility, non-segregation ability and fillingability. And because the aggregate which is one of the factors occupies high volume in concrete, it has a much effect on the properties of high flowing concrete according to its size, quality and quantity etc. This is an experimental study to analyze the effect of admixture and volume of coarse aggregate in concrete on the flowing properties of high flowing concrete. For this purpose, the kinds of admixture are fly-ash and blast furnace slag. Also volume of coarse aggregate in concrete are 280, 290, 300, 310, 320 $(\ell/m^3)$. The test of flowablity properties is slump-flow, Air content, V-lot, L-Flow. According to test results, it was found that the compactibility of HFC is more superior to use blast furnace slag than other, and according .to kind of admixture, most compatible volume of coarse are different. Also when used blast furnace slag, the volume of coarse are increased than used fly-ash.

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