• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2008년도 춘계 학술발표회 제20권1호
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• pp.1109-1112
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• 2008

콘크리트 구조물은 성형성 및 경제성이 뛰어나며 우수한 강도발현으로 인해 보편적인 구조재료로 인정받고 있다. 그러나, 최근 3D 기피현상으로 인하여 건설 작업자의 고령화 및 숙련공 부족현상이 국내건설 산업의 중요문제로 부각되고 있으며, 또한 콘크리트 구조물이 점차 고층화, 대형화 및 특수화 됨에 따라 부재의 형상이 다양하고 복잡해지고 있어 신기술 신공법에 의한 건설공사의 합리화가 요구되고 있다. 이러한 건설환경의 전반적인 여건에 따라 높은 시공의 효율성 및 품질 향상을 위한 고유동 콘크리트에 대한 연구 및 개발이 필요한 시점이다. 따라서 본 연구에서는 고유동 콘크리트의 연구개발 동향 및 개발 현황에 대하여 조사하였으며, 고유동 콘크리트의 성능평가에 사용되는 실험방법 및 국내 외 성능규준에 대하여 정리하였다.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2019년도 춘계 학술논문 발표대회
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• pp.101-102
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• 2019

The use of high fluidity concrete has been added in recent construction work. In this study, we analyzed segregation resistance due to admixture substitution of the system high fluidity concrete that was hardened. The research results show that the resistance to segregation at the time of admixture replacement is improved. The best results were shown with a ternary system mixed like FA and BS.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2015년도 춘계 학술논문 발표대회
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• pp.42-43
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• 2015

This study has analyze the suitable area of slump and slump flow among the fluidity evaluation of concrete by measuring slum and slump flow variation according to unit quantity and fine aggregate percentage in a low W/C mix. The fluidity of concrete can be expressed well with the slump value when sump value is 122mm or less. On the other hand, the fluidity of concrete can be expressed more accurately with slump flow value when slump is 122mm or greater.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1998년도 가을 학술발표논문집(II)
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• pp.301-306
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• 1998

Aggregate as the component of High Flowing Concrete has much influence on the properties of High Flowing Concrete according to the quality and condition because the aggregate occupy a lot of concrete volume. The shape and size of aggregate affect a lot spatial passibility and fillingability. The segregation is easy to occur when the rate of Fine aggregate is high so that Fluidity is much affected by aggregate factor. In this study, therefore, we try to understand the various fluidity according to the fine aggregate of standard grade rang, the size of Coarse aggregate and the rate of fine aggregate to confirm the manufacturing possibility of High Flowing Concrete by examination on the influence of fresh state of high flowing concrete such as flowability, reinforcement passibility, fillingability, segregation resistance.

• International Journal of Concrete Structures and Materials
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• 제6권4호
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• pp.231-237
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• 2012

Recently, it has been difficult to get natural sand for concrete due to an insufficient supply in Korea. Crushed sand was thought as a substitute and previous research has been focused on low fluidity and normal compressive strength (24-30 MPa). Study on high performance concrete using crushed sand is hardly found in Korea. In this study it was investigated that the effect of the crushed sand on fluidity and compressive strength properties of high performance concrete. Blending crushed sand (FM: 3.98) produced in Namyangju, Kyunggido and sea sand (FM: 2.80) produced in Asan bay in Chungnam. The final FMs of fine aggregate were 3.50, 3.23, and 3.08. W/B was set as 0.25 to get high performance. With the test results an analysis of relationship was performed using a statistical program. It was shown that strength property of concrete using crushed aggregate at the very early age or after specific time was mainly affected by strength development properties of binders instead of the crushed sand.

• Computers and Concrete
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• 제11권6호
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• pp.531-539
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• 2013

An experimental investigation of mechanical properties of jute fiber-reinforced concrete (JFRC) has been reported for making a suitable construction material in terms of fiber reinforcement. Two jute fiber reinforced concretes, called jute fiber reinforced normal strength concrete (JFRNSC) and jute fiber-reinforced high-fluidity concrete (JFRHFC), were tested in compression, flexure and splitting tension. Compressive, flexural and splitting tensile strengths of specimens were investigated to four levels of jute fiber contents by volume fraction. From the test results, Jute fiber can be successfully used for normal strength concrete (NSC) and high-fluidity concrete (HFC). Particularly, HFC with jute fibers shows relatively higher improvement of strength property than that of normal strength concrete.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2022년도 봄 학술논문 발표대회
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• pp.55-56
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• 2022

Recently, water leak is increasing due to poor compaction or segregation of concrete on external wall. In addition, the flatness quality of the slab is lowered due to the deterioration of the workability of concrete. In this study, the performance of high fluidity concrete of 21MPa using a polycarboxylate-based superplasticizer was evaluated to improve the compaction and quality of the concrete wall.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1990년도 봄 학술발표회 논문집
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• pp.16-19
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• 1990

The effect of superplasticizers on the fluidity performance in fresh concrete and physical properties in hardened concrete have been analyzed and investigated under mix proportions of water cement ratio of 0.4, 0.6, crushed stone aggregates, and addition rates of superplasticizers of 0.0, 0.5, 1.0 and 1.5 in the practical range. It is the aim of this study to provide the fundamental data on the workability improvement and engineering properties of crushed stone concrete using superplasticizers comparing with conventional concrete for the practical use and research data accumulation of superplastized concrete.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2000년도 가을 학술발표회논문집(I)
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• pp.661-664
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• 2000

It is known that high flowing concrete performs much higher fluidity, segregation resistibility and better placeability than normal concrete. However, it is hard to apply high fluidity concrete in field because of high manufacturing cost. Therefore, we intend to investigate the validity of segregation reducing type superplasticizer which is made by combining 0.61 of viscosity agent and 0.022 of AE agent for 1 of superplasticizer. Test are conducted on high flowing concrete using fly ash by applying segregation reducing type superplasticizer. According to experimental results, As contents of fly ash increase, fluidity, segregation resistibility and placeability shows favorable results. And also compressive strength at early age shows to be retarded, while it gains high strength at later age.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2007년도 추계 학술논문 발표대회
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• pp.75-78
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• 2007

The steel slag, a by-product which is produced by refining pig iron during the manufacture of steel, is mainly used as road materials after aging. It is necessary to age steel slag for long time in air because the reaction with water and free-CaO in steel slag could make the expansion of volume. This problem prevents steel slag from being used as aggregate for concrete. However, steel slag used in this study was controled by a air-jet method which rapidly cools substance melted at a high temperature. The rapidly-chilled method would prevent from generation of free-CaO in steel slag. Also, Molten steel slag rapidly-chilled by air in high speed becomes a fine aggregate of nearly spherical shape. This study dealt with the influence of the using rate of rapidly-chilled steel slag and polymer resin on fluidity of polymer concrete, as a results Since RCSS has spherical shape and high density, up to replacement ratio of 100%, increases concrete fluidity under same polymer content and decrease polymer content in order to secure the same fluidity