• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2003년도 가을 학술발표회 논문집
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• pp.156-159
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• 2003

Large amount of binders and high-range AE water-reducing (HRWR) agent are required for self-consolidating concrete in order to achieve flowability and segregation resistance. In this study, the initial permeability of SSC(self-consolidating concrete) until the age of 28 days is measured and compared with those of other SSCs, in which some parts of cement are substituted with fly ash or blast furnace slag. The strengths of SSC samples are also examined along with the permeability change.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2017년도 추계 학술논문 발표대회
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• pp.73-74
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• 2017

In this study, unlike high flowing concrete, using glass bubble to develop self-compacting concrete(hereinafter referred to as "SCC") with excellent filler performance by evaluating both flowability and yield stress, viscosity An experiment was conducted. Experimental results show that when 1 kg of glass bubbles are used, it is effective in stabilizing the physical properties of concrete, reducing the yield stress and viscosity.

• 콘크리트학회논문집
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• 제13권5호
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• pp.476-483
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• 2001

초유동콘크리트는 유동성 증진 및 충전성 향상을 위해 단위분체량을 크게하기 때문에 콘크리트의 고강도화와 수화발열량을 증가시키는 문제점을 가지고 있다. 이에 본 연구는 초유동콘크리트의 강도조절과 수화열 저감을 위해 쇄석분을 이용하여 초유동콘크리트의 강도, 유동성, 내구성능 및 건조수축 특성을 검토하였다. 실험결과 쇄석분은 치환율 10% 증가시마다 무치환시의 압축강도를 약 10~15%씩 감소시키며, 변형계수와 물구속비를 감소시켜 초유동콘크리트의 유동성 향상에 효과적이다. 또한 초유동콘크리트에서 쇄석분 10%치환시 마다 단위시멘트량 감소에 따른 최고 단열온도상승량을 약 4$^{\circ}C$씩 감소시켰다. 반면 건조수축량은 10%치환시 마다 약 5%증가시켰다. 한편 초유동콘크리트의 내구성능은 단위분체량과 유동성향상에 따른 조직의 치밀화로 쇄석분 치환에 관계없이 상대동탄성계수 90%이상으로 우수하게 나타났다. 이와 같이 분체로서 쇄석분 사용은 치환량에 따른 초유동콘크리트의 강도조절이 가능하며 수화발열량을 저감시킬 수 있다. ^ x Super flowing concrete causes high strength and the increase of heat of hydration because of the big unit powder content of concrete to increase flowability and to improve compact of concrete. Therefore, this study investigates the characteristic properties of strength, flowability, durability and drying shrinkage to control strength and to reduce heat of hydration of super flowing concrete using crushed stone fines. According to the experimental results, when crushed stone fines are increased every 10%, 10~15% of compressive strength is decreased and flowability of super flowing concrete is effectively improved due to the decrease of modulus of deformation and confined water ratio. When crushed stone fines are replaced every 10%, 4$^{\circ}C$ of the highest adiabatic temperature rise is decreased by reducing the unit cement. However, 5% of drying shrinkage is increased in the same condition. In the meantime, durability of super flowing concrete is excellent, having over 90 % of good relative dynamic modulus of elasticity due to fineness of formation caused by the increase of the unit powder content and the improvement of flowability, without regard to the replacement of crushed stone fines. Therefore, it can be said that the usage of crushed stone fines can control the strength of super flowing concrete by replacement and reduce heat of hydration.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1996년도 봄 학술발표회 논문집
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• pp.42-47
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• 1996

Due to high increase of labor charge and necessarity of better quality control on concrete, various studies have been carried out to improve a flowability of concrete without the use of mechanical vibrator. As a result of enthusiastic study, one can closely access to the development of high flowable concrete in a laboratorial view. Application to practical field, however, is still far as long as a regulation for construction is not properly specified. Based on the idea that lateral pressure measured from high flowable concrete will be larger than those from general typed concrete, we read a series of lateral pressure from mechanical pressure plate and compared those with the values calculated form specified formula.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2002년도 가을 학술발표회 논문집
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• pp.561-566
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• 2002

Recently, high quality exposed concrete is needed to achieve high quality surface for outer wall of the building. In this study, to solve above characteristic of the exposed concrete we selected self compacting concrete(SCC) and compared with normal concrete. So, we developed the SCC mix design and performed the semi mock-up test. Through this result, we performed the pilot test and mock-up test to check surface of outer wall and to measure formwork pressure As a result because SCC is better than normal concrete with respect to flowability and seggregation resistance SCC is suit to a exposed concrete needed high quality surface for outer wall of the building.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1994년도 가을 학술발표회 논문집
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• pp.65-70
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• 1994

The aim of this study is to develop the High Workable Concrete which has not so large slump loss with time using blast-furnace cement and High range water reducing agent. Normal portland cement and blast-furnce cement was used as binders and water-binder ratio were ranging from 34% to 50%. 5 kinds of Superplasticizer and High range water reducing agent were used. Test results show that the blast-furmace cement was much higher flowability than normal portland cement and domestic High rang water reducing and AE agent had very small slump loss than others. The compactability of High Workable Concrete was also confirmed using model wall-form.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2005년도 추계 학술발표회 제17권2호
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• pp.407-410
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• 2005

This research investigates experimentally an effect on the properties of the combined high flowing concrete by mix design factors. The purpose of this study is to determine the optimum mix proportion of the combined high flowing concrete having good flowability, viscosity, no-segregation and design strength(40.0MPa). For this purpose, trial mixings used belite cement+lime stone powder(LSP) are tested by mix design factors including water-cement ratio($47.9\~54.0\%$), fine aggregate volume ratio($41\~45\%$) and coarse aggregate volume ratio($41\~45\%$). As test results of this study, the optimum mix proportion for the combined high flowing concrete is as followings. Water-cement ratio $51.0\%$, fine aggregate volume ratio $43{\pm}1\%$ and coarse aggregate volume ratio $0.30{\pm}0.05m^3/m^3$ and replacement ratio of LSP $42.7\%$.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2010년도 춘계 학술대회 제22권1호
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• pp.185-186
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• 2010

본 연구에서는 해양환경하에서 Mega Foundation용 고내구성 콘크리트를 개발하고 개발된 콘크리트의 성능 평가를 위해 Mock Up Test를 수행하였다. Mock Up Test를 위해 국내외 최대규모인 $4m{\times}4m{\times}4m$의 Mock Up 구조물 2개를 제작하였으며, 각 구조물에 각기 다른 배합의 콘크리트 및 타설시간 등을 고려하여 다양한 인자의 영향성 분석을 수행하였다.

• 콘크리트학회지
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• 제10권6호
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• pp.281-289
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• 1998

본 연구는 해양 매스 콘크리트 구조물인 서해대교 사장교 주탑기초(L${\times}$D${\times}$H : 66${\times}$28${\times}$32~38.2)에 콘크리트 타설시 다짐작업을 생략할 수 있고, 수화열에 의한 온도균열 발생을 제어할 수 있는 콘크리트의 사용에 대하여 적극적으로 검토한 것으로서 혼합형 저발열 시멘트를 사용한 초유동 콘크리트와 현장에서 사용중인 5종 시멘트를 사용한 25-240-15 보통 콘크리트를 주탑 기초 일부분에 적용하여 유동성, 강도발현 성능, 재료분리 저항성, 수화열, 내해수성 등을 비교 평가한 것이다. 그 결과, 저발열시멘트를 사용한 초유동 콘크리트는 별도의 다짐 작업없이도 우수한 작업성과 자기 충전성, 재료분리 저항성을 나타냈으며, 5종시멘트를 사용한 25-240-15보통 콘크리트보다 단위시멘트량이 54kg/$m^2$ 정도 증가했음에도 불구하고 오히려 수화열은 $10^{\circ}C$이상 저감되어 온도균열 제어에 매우 효과적임을 확인할 수 잇었다. 또한 부재에서 채취한 코아의 압축강도는 5종시멘트를 사용한 25-240-15 보통 콘크리트와 동등한 강도 발현율을 나타내었다. 특히 해수중 염소이온의 침투에 대한 저항성을 평가하기 위해 실시한 촉진 염소이온침투 시험결과 통과전하량이 5종 보통 콘크리트보다 5배정도 낮게 나타났으며, 기타 화학물질에 대한 저항성은 비슷한 경향을 보였다. 따라서 저발열 시멘트를 사용한 초유동 콘크리트는 유동성개선에 의한 다짐 작업의 생략 효과와 더불어 수화열 저감 효과에 따른 온도균열제어 및 공기단축 등으로 주탑기초의 콘크리트에 매우 유리한 시멘트라고 판단되었다.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2000년도 봄 학술발표회 논문집
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• pp.237-242
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• 2000

Recently, the importation of overseas cement has been increasing and the spot materials of different quality from Japan have to be treated in overseas construction work for technical cooperation with neighboring countries. However, a study on the quality of those oversea materials has not yet been carried out systematically, especially cement among those materials. Accordingly, in this study the properties of high-strength concrete with oversea cement imported from four countries in East Asia and South-east Asia were investigated under normal and high temperature condition, including the carbonation of normal-strength concrete under normal temperature. As a result, it is found that the required of normal-strength concrete will be expected regardless of temperature condition when the flowability is ensured by selecting the appropriate superplaticizer and dosage of it, and the carbonation rate of normal-strength concrete with overseas cement is approximately the same as that with Japanese one under the condition of the same compressive strength.