• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2000년도 봄 학술발표회 논문집
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• pp.269-274
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• 2000

As a result of the reduction of natural aggregate, most of developed country have been studied the utilization of Blast-furnace Slag(BFS) as aggregate of concrete. bur, in korea there are only basic study about these even though other country are using Blast-furnace Slag production of Ready Mixed Concrete. According, in this study, we carried out fundamental experiments in order to know the material properties of BFS and possibilities of the BFS as fine aggregate of concrete. It is included that analysis concerning material properties of BFS as like specific gravity, absorption. unit weigth, grading including investigation of the surface shape by SEM, also, analysis concerning properties of concrete with BFS as like air-content surface slump. compressive strength .etc.

• 콘크리트학회논문집
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• 제12권5호
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• pp.59-68
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• 2000

A series of experiments were performed to investigate the strength characteristics of concrete which contain air cooled blast-furnace slag as coarse aggregate. The slag is a by product of GISC. The experimental conditions are varied with three different W/C(45%, 50%, 55%) and the weight of water and S/a are constant. The strength properties of the concrete at 7days, 28days, 90days are examined. Also the same strength properties are examined for the normal concrete which contain river gravel and crushed stone respectively as coarse aggregate. As the comparison results of the strength properties, it was found that the compressive strength development of concrete containing blast-furnace slag is better than that of concrete using river gravel at early age, however this is adversely at long-term age, and the tensile and flexural strength of the concrete were not nearly affected by water-cement ratio.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2018년도 춘계 학술논문 발표대회
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• pp.218-219
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• 2018

This study analyzed the unit weight and compressive strength properties of lightweight concrete using high volume blast furnace slag powder by the mixing ratio of lightweight coarse aggregate to investigate the properties of lightweight concrete using domestic artificial lightweight aggregate.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2005년도 봄학술 발표회 논문집(II)
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• pp.513-516
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• 2005

Previous study on recycled aggregate(RA) has largely been limited to the manufacture of nonstructural-grade concrete due to undesirable physical properties of them such as, high water absorption leading to high water demand of concrete. The restriction seriously limits its market and consequently diminishes the use of RA as a construction material. This paper presents the mechanical properties of recycled concrete substituted by both waste foundry sand(WFS) and recycled coarse aggregate replaced with fine and coarse aggregate concurrently. The result shows that the compressive and tensile strength decrease with the increment of substitution ratio of RA and WFS while bending strength of RA concrete increase.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2002년도 봄 학술발표회 논문집
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• pp.643-648
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• 2002

A research for recycling the demolished-concrete as concrete aggregate has been concerned in all over the world. There, however, are some problems that qualities of recycled aggregates are not only largely different, but also mechanical properties of recycled aggregate concrete decrease a little in comparison with that of natural aggregate concrete. In this study, the resistance of freezing and thawing of concrete using source-concrete recycled aggregate(SRN) and demolished-concrete recycled aggregate(DRA) was investigated. Futhermore a research for improvement of freeze and thaw durability of recycled aggregate concrete was performed. Relative dynamic modulus of elasticity of SRN and DRA recycled aggregate concrete was dropped 60% before 150 of freezing and thawing cycle, and was much lower than that of control concrete. Relative dynamic modulus of elasticity of recycled aggregate concrete was increased to decrease water-cement ratio, but the freeze and thaw durability of recycled aggregate concrete was not enough improved. Futhermore, when metakaolin and silica fume were repalced, the freeze and thaw durability of recycled aggregate concrete containg metakaolin was more improved than that of silica fume.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2004년도 춘계 학술발표회 제16권1호
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• pp.384-387
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• 2004

Though recycled aggregate is useful resources for concrete, its application to structural frame is not frequent, because of low quality of recycled aggregate. Owing to the development of manufacturing technology to recycled aggregate, it is possible to produce high quality recycled aggregate. The purpose of this study is to confirm the applicability of the high quality recycled aggregate, instead of the natural aggregate, to normal concrete. Main factors of this study are substitute proportion of recycled aggregate, types of recycled aggregate, targeting compressive strength of recycled concrete. From the results of the study, we concluded that it is possible to use high quality recycled aggregate, to get the same strength as concrete using normal aggregate.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1996년도 봄 학술발표회 논문집
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• pp.12-17
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• 1996

It is true that aggregate strength is usually not a factor in normal concrete strength because, the aggregate particle is several times stronger than the matrix and the transition zone in concrete. In other words, with most natural aggregates the strength of the aggregate is hardly utilized because the failure is determined by the other two phases. But aggregate characteristics that are significant to concrete technology include porosity, grading or size distribution, moisture absorption, shape and surface texture, crushing strength, elastic modulus, and the type of deleterious substances present. Therefore, in the area of high strength concrete, concrete is much more influenced by properties of aggregate. This experiment is performed to investigate how kinds of aggregare influence on the workability of high strength concrete. In this experiment, four types of aggregate is used, that is crushed river aggregate, crushed stone, recycled aggregate of low strength and recycled aggregate of high strength. In this study, we scrutinize a fundmental study on the workability of high strength concrete according to kinds of aggregate.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2004년도 학술대회지
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• pp.15-19
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• 2004

The production of waste concrete is increased continuously by urban renewal, reconstruction, remodeling, and so on. So the positive use of recycled aggregate concrete is needed. Research for recycled aggregate concrete that use recycled aggregate from the mid-80s to solve environmental problem of aggregate insufficiency and waste concrete is consisting vigorously. However, specifications and mix design about waste concrete's use are evading use of recycled aggregate concrete yet in spot being not taken a triangular position. Therefore. it analyze existing research data for recycled aggregate concrete collection to develop strength estimate program in this research. Recycled aggregate concrete's strength estimate program if specifications and mix design about recycled aggregate concrete are taken a triangular position to foundation recycled aggregate concrete's practical use to increase judge.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2008년도 춘계 학술발표회 제20권1호
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• pp.465-468
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• 2008

본 연구는 영, 호남 지역의 레미콘 공장에서 현재 사용하고 있는 잔골재의 특성을 분석하고, 혼합사용 시 잔골재율 조정에 따른 콘크리트의 특성실험을 통하여 혼합사용 시 최적조건을 분석한 것으로 그 결과를 요약하면 다음과 같다. 영, 호남에서 사용하는 골재 종류별 물성은 조립률 및 0.08mm체 통과량을 제외하고 모두 KS F 2526 및 KS F 2527의 규정에 적합한 것으로 나타났는데, 각 공장에서는 단독사용이 부적합한 골재를 2종 이상 적절한 비율로 혼합사용하고, KS규정에 적합하게 품질을 관리하고 있었다. 영, 호남 각 공장에서 단위용적질량법에 의해 산출한 잔골재율로 조정한 콘크리트의 배합은 기존의 출하배합보다 높은 유동성을 보이는 것으로 나타났는데, 이는 잔골재율 약 2% 저감에 따라 잔골재의 표면적 감소 및 공극감소에 따른 시멘트 페이스트의 유동성에 미치는 잉여수량의 상대적 증가에 기인한 것으로 분석된다. 따라서 최적 잔골재율을 적용함으로써 단위수량 감소로 인한 경제적인 콘크리트 배합과 콘크리트의 내구성을 증진시키는 효과가 있을 것이라 사료된다.

• 한국건설순환자원학회논문집
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• 제8권4호
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• pp.537-544
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• 2020

Interfacial transition zone (ITZ)은 골재-시멘트 복합체 사이의 영역으로써, 콘크리트에서 가장 취약한 영역으로 알려져 있으며, 이는 점진적으로 변화하는 불균질한 상으로 이루어져 있다. 경량 고강도 콘크리트 개발을 위해 물-바인더 비가 낮은 고강도 시멘트 복합체와 경량골재 사이의 Interfacial transition zone (ITZ)의 역학적 특성 평가는 필수적이다. 하지만 ITZ는 복잡하고 다공성 구조를 가지고 있기 때문에, 이의 역학적 특성은 아직 명확하지 않다. 또한, 경량골재 ITZ는 일반골재보다 다양한 변수 (물-바인더 비, 골재의 흡수율, 양생조건 등)에 의해 변화한다. 따라서 본 연구에서 골재의 종류 및 크기에 따른 ITZ의 역학적 특성을 분석하고자 한다. 이를 위해 나노 인덴테이션 기법을 이용하여 물-바인더 비가 0.2인 고강도 시멘트 복합체와 표준사 및 최대치수가 각각 2mm, 5mm인 경량골재 ITZ의 탄성계수를 측정하였다.