• Title/Summary/Keyword: 고유동콘크리트

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Possibility Analysis on Reducing Formwork Leakage of High-fluidity Mortar by Using PVA and Borax (PVA 및 붕사를 사용한 고유동 모르타르의 거푸집 누출량 저감 가능성 분석)

  • Kim, Young-Ki;Lee, Yu-Jeong;Heo, Jun-Ho;Han, Dongyeop
    • Journal of the Korea Institute of Building Construction
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    • v.22 no.2
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    • pp.125-136
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    • 2022
  • This research is to reduce the formwork leakage of high-fluidity concrete caused by insufficient accuracy of formwork fabrication widely used for high-fluidity concrete to general strength concrete. However, in the actual construction site, because of the insufficient accuracy of formwork fabrication may cause leaking concrete of mortar through a gab of the formwork. Therefore, in this research, which builds on previous research into providing thixotropy with PVA and Borax, the use of thixotropy to reduce high-fluidity mortar leakage was evaluated. The results of the experiment proved that the use of thixotropy with PVA and Borax can contribute to reduction of the formwork leakage of high-fluidity mortar. This finding is expected to lead to further research on reducing leakage of high-fluidity concrete.

A Study on Fluidity ability, Filling ability Properties of High Fluidity Concrete with Illite Powder (일라이트 미분말을 혼입한 고유동 콘크리트의 유동성 및 충전성에 관한 연구)

  • Lee, Dong-Un;Lee, Maeng-Gyo;Park, Hyun-Jung
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.16 no.12
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    • pp.8363-8369
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    • 2015
  • This study is to be investigate properties of workability, compacting and compressive strength replaced by the illite powder in high fluidity concrete. For this purpose, illite powder has replaced the binder of high fluidity concrete of 5%, 10%, 15%, 20%. After concrete mixing, slump flow test, reach time slump flow 500mm, O-lot test were conducted on fresh high fluidity concrete. And compressive strength was determined 28 days for the hardened high fluidity concrete specimens. According to the test results, the workability, filling height of high fluidity concrete were increased in 10% replacement of illite powder. Furthermore, the compressive strength of high fluidity concrete was increased in 10% replacement of illite powder.. It was possible to confirm that optimal mixture ratio of illite powder seems to exist, and it is shown to be 10% according to our experimental results.

Flowing Characteristic of High Flowing Self-Compacting Concrete with mixing Steel Fiber (강섬유 혼입에 따른 고유동 자기충전 콘크리트의 유동특성)

  • Choi, Yun-Wang;Choi, Wook;Kim, Gi-Beom;Jeong, Jae-Gwon;Ahn, Tae-Ho;Eom, Joo-Han
    • Proceedings of the Korea Concrete Institute Conference
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    • 2008.04a
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    • pp.461-464
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    • 2008
  • This study is compactability and Passing ability to get to know the flowing characteristic of high flowing self-compacting concrete with mixing steel fiber of various size and diameter. After flowing test, size and diameter are getting longer, flowing performance is getting lower. It meets the standard of combined high flowing self-compacting concrete of JSCE 2 grade and passing performance from ASTM C 1621. Through this study, it can be possible to be applied in site of HSCC with mixing steel fiber.

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

  • Choi, Yun-Wang;Choi, Byung-Keol;Oh, Sung-Rok
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.20 no.3
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    • pp.122-129
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    • 2016
  • In this study, we developed a pressing device which can reproduce the pressure of concrete inside the conveying pipe as a part of the basic study to development of high fluidity concrete under high pressure pumping. Using this pressing device, we evaluated a absorption properties of aggregate that are crushed coarse aggregate, river gravel and lightweight coarse aggregate according to pressure of coarse aggregate and aggregate inside a high fluidity concrete, focused on the reduction of unit water quantity by pressure. In addition, it was evaluated the compressive strength of high fluidity concrete about before and after of pressive. Test a result, case of condition under the high pressure of 250 bar, absorption ratio of crushed coarse aggregate and river gravel were not increased above the surface absorption, absorption ratio of lightweight coarse aggregate was increased than the surface absorption.

Effect of Waste Marble Powder on the Fundamental Properties of High Fluidity Concrete (폐 대리석 분말을 혼입한 고유동 콘크리트의 기초적 특성에 대한 실험적 연구)

  • Lee, Yong-Moo;Shin, Sang-Yeop;Kim, Young-Su
    • Journal of the Korea Institute of Building Construction
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    • v.15 no.2
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    • pp.153-160
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    • 2015
  • The marble powder is a by-product that can be freely collected during the manufacturing process of marble, such as sawing, shaping, and polishing. Disposal of this waste powder is one of the environmental problems worldwide today. Therefore, this study investigated to solve this problem by consuming the waste marble powder in high fluidity concrete, as a pore filler. For this purpose, the waste marble powder was used as a binder replacing 5%, 10%, 15%, and 20% of cement in high fluidity concrete. After mixing, slump flow test, time-to-reach the slump flow of 500mm test, O-lot test and U-box test were conducted with fresh concrete. For the hardened concrete, compressive strength was determined at the age of 28 days. According to the test results, the workability of high fluidity concrete increased with the powder of 15% replacement, and the compressive strength of high fluidity concrete also increased with the same amount of powder.

The Comparative Experimental Study of short and long-term Behavior of the Blended High-Fluidity Cement Concrete and Existing Nuclear Power Plant Structural Concrete (기존 원전용 콘크리트와 다성분계 고유동 콘크리트의 장·단기거동 비교 실험 연구)

  • Lee, Pyung-Suk;Kwon, Ki-Joo;Kim, Su-Man
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.8 no.4
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    • pp.195-202
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    • 2004
  • In this study, it was founded to make the optimal mixture for producing concrete which is self-compacting, yet, and generates low heat of hydration by using flyash, blast furnace slags and limestone powders as binders in addition to cement while using super-plasticizers and viscosity agents as admixture agents. The structural behaviors of the concrete produced with the selected mixture were compared with those of the concrete currently using for construction of nuclear power plants. The study shows that the blended high fluidity concrete including limestone is better in workability and durability than the concrete currently in use for nuclear power plants.