• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2003년도 가을 학술발표회 논문집
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• pp.44-47
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• 2003

High flowing concrete has not spread whole in the normal concrete structure, because it requires special quality control technique. Recently owing to the lack of natural resources and reinforcement of environmental standard, the construction cost of cement is rapidly increased. Also ready mixed concrete industry has gone through various economical difficulty as the manufacture cost of concrete is increased. So, the purpose of this study is to evaluate the qualities of middle fluidity concrete using the fly-ash and portland blast-furnace slag cement in order to decrease the amount of cement and resolve the problem of the quality control of high flowing concrete and the manufacture cost. The results of this study show that it reduces the amount of addition of superplasticizer and develope properties of concrete to the use the fly-ash and portland blast-furnace slag cement.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1998년도 봄 학술발표회 논문집(I)
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• pp.45-50
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• 1998

This study is aimed for investigating the rheology property and fluidity of superplasticizer which is necessary using for high flowing concrete fluidity establishment. Therefore, this study is analysis the rheology property and fluidity by different according temperature and elapsed time. From the results, the fluidity and rheology value were different according temperature. Over 2$0^{\circ}C$, the flow value of A, B, C, D, E type is increased, according as the increase of temperature, but the flow value of F type is decreased.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2008년도 춘계 학술논문 발표대회
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• pp.87-91
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• 2008

The study examined fire resistance of concrete followed by change of mixed rate in PP and NY composite fiber and the results were as follows. In the event of fluidity in concrete not set, plane satisfied 600±100, its target slump flow, and fluidity was reduced as organic fiber's mixed rate was increased. Air amount satisfied 3.0±1.0, its target air amount, and didn't have distinct differences in reduction and increase according to organic fiber's kind and change of its mixed rate. However, it had a tendency that fluidity was reduced as the mixed rate was increased. In characteristics of hardening concrete, the 28th day compressive strength followed by organic fiber's kind and change of its mixed rate didn't have a lot of differences and satisfied high strength scope as about 70MPa. In spalling characteristics after fire resistance test, spalling was happened in non-mixture, plane combination, and P1N0. In other combinations, spalling resistance was happened. The relic compressive strength rate was 56%, the best condition, in P3N1(PP0.03%, NY0.01% compositeness) mixing PP fiber with NY fiber at once.

• 한국구조물진단유지관리공학회 논문집
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• 제14권4호
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• pp.160-168
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• 2010

최근 고유동 콘크리트(High Fluidity Concrete 이하 HFC)에 대한 연구는 많은 시공사례와 함께 진행되고 있지만, 콘크리트의 내구성능을 평가하는 항목 중 하나인 염소이온 침투에 대한 연구는 미비하며, 기존의 내구성관련 연구는 고강도 이상(40MPa)연구됨에 따라 보통강도 고유동 콘크리트의 염소이온 침투에 관한 연구는 찾아보기 어려운 실정이다. 따라서 본 연구에서는 석회석 미분말을 혼합한 보통강도 HFC를 제조하여 콘크리트의 공극구조 및 염소이온 침투특성을 분석 고찰하였다. 실험결과 석회석 미분말을 혼합한 2성분계 및 3성분계 고유동 콘크리트의 경우 콘크리트의 공극 크기는 0.005~0.05 ${\mu}m$ 사이에서 가장 많이 분포하고 있으며, 석회석 미분말의 혼합률이 증가할수록 평균 공극 직경은 커지는 것으로 나타났다. 또한 석회석 미분말의 혼합률이 증가할수록 염소이온 침투깊이 및 확산계수는 증가하는 경향이 나타나며, 확산계수는 압축강도 및 평균공극직경 사이의 상관관계에서 결정계수 0.90 이상의 양호한 상관성이 있었다.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1997년도 봄 학술발표회 논문집
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• pp.136-145
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• 1997

The purpose of this study is to develope of alternative adimixture for manufacture of PHC pile(compressive strength above 800kg/$\textrm{cm}^2$). For the investigation, properties of alternative admixture admixed with II-anhydrite and pozollanic fine powders(e.q., Fly-ash, Silica-Fume), the fluidity and viscosity in the cement pastes, the fluidity and compressive strength in mortars at steam curing condition, were respectively examined. Also, properties of compressive strength of concretes with exiting admixture(specimen name SM) and alterantive admixture(specimen name AP) for PHC pile, at steam and standard curing condition, were compared each other. As a result of this experimental study, it was found that specimens admixed with II-anhydrite and pozollanic fine powders had an increase on the fluidity of cement paste and mortar, and compressive strength of mortar and concrete was as good as concrete with SM.

• 한국건축시공학회지
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• 제7권1호
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• pp.57-62
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• 2007

Generally, the strength of concrete depends on factors of materials, mix proportions, compaction, manufacturing methods and curing and so on. And recently, it has increased the using of crushed sand for concrete due to the exhaustion of good natural aggregate. In case of Korea, in 2004, the using ratio of crushed sand occupies about 28% of whole fine aggregate. This is an experimental study to compare and analyze the influence of W/B ratio and replacement ratio of crushed sand on the fluidity and compressive strength of high strength concrete. For this purpose, the mix proportions of concrete according to the W/B (31.5, 27.5, 23.5%) and replacement ratio of crushed sand (0, 20, 40%) was selected. And then air content, slump-flow, a-lot, compressive strength test were performed.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2003년도 가을 학술발표회 논문집
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• pp.473-476
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• 2003

This study discusses the use of anti-shrinkage agent as the method to reduce autogenous and drying shrinkage. According to results, as for the fundamental properties of high performance concrete, fluidity and strength decrease with an increase of the adding ratio of anti-shrinkage agent, but air content increases. Compared with plain concrete, autogenous and drying shrinkage are reduced by 12~52% and 4~22% respectively upto the adding rario of anti-shrinkage agent of 2.0%. When expansive additive is added by 5.0%, they are also reduced by 38~95% and 15~50% respectively. Therefore, as expansive additive of 5.0% and anti-shrinkage agent of 1.0% are added to high performance concrete of around W/B 30%, it is considered that fluidity and strength are hardly influenced, and in addition, crack by shrinkage can be prevented effectively.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2002년도 봄 학술발표회 논문집
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• pp.539-544
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• 2002

The properties of mortar and concrete including metakaolin as a partial cement replacement were investigated in terms of fluidity and compressive strength. The results show that mortar and concrete in which 10 % of cement is replaced with metakaolin exhibit much higher compressive strength after 3 days of hydration than ordinary Portland cement, indicating that metakaolin can be used in the production of high strength concrete replacing silica fume. The type of superplasticizer largely affected on the fluidity and compressive strength of mortar and concrete including metakaolin. It was concluded that when metakaolin is used for the purpose of manufacturing high strength concrete, it is desirable to use PNS based blends rather than PNS, PMS and polycarboxylate based superplasticizer.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2009년도 춘계 학술대회 제21권1호
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• pp.543-544
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• 2009

고강도콘크리트의 내화성능 증진에 효과적인 것으로 알려진 섬유(NY, PP)는 섬유의 길이조합과 혼입율에 따라 유동성에 차이가 있다. 본 논문에서는 섬유의 길이조합과 혼입율이 고강도콘크리트의 유동성과 레올로지 특성에 미치는 영향을 분석하기 위하여 몰탈시험체를 대상으로 미니 슬럼프 플로우(Mini slump-flow), 간이 V-lot 및 회전점도계에 의한 점도측정을 수행하였다. 실험결과, 섬유의 길이 조합에 따른 유동특성은 큰 차이가 없으나 섬유혼입률이 증가할수록 점도는 큰 것으로 나타났다.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2010년도 춘계 학술대회 제22권1호
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• pp.393-394
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• 2010

본 논문은 고압송용 저점도 고유동 콘크리트를 개발하기 위한 연구의 일환으로 페이스트 및 모르타르의 소성점도 및 항복응력을 검토하였다. 이 연구를 통하여 고압송용 저점도 고유동 콘크리트에 페이스트 및 모르타르의 적절한 재료특성을 검토하고자 한다.