• 한국건축시공학회:학술대회논문집
• /
• 한국건축시공학회 2018년도 춘계 학술논문 발표대회
• /
• pp.140-141
• /
• 2018

There are three types of high fluidity concrete: powder based, VMA based, and combined. In the case of the powder based high fluidity concrete mixture, according to the textbook, increased viscosity due to the replaced fly ash can prevent segregation of coarse aggregate. On the other hand, decreased density of the powder due to the fly ash replacement can causes segregation but there is no report on this issue. Therefore, in this research, the segregation resistance and segregation evaluation method for powder based high fluid concrete mixture are evaluated. As a result, with increased replacing ration of supplementary materials, EIS value was decreased and apparently segregation resistance was increased. However, from the compressive strength evaluation depending on height of the cylindrical specimen, it was confirmed that the different of strength difference between top and bottom part of the specimen. Thus, following research regarding vertical segregation should be studied.

• 한국건축시공학회:학술대회논문집
• /
• 한국건축시공학회 2018년도 추계 학술논문 발표대회
• /
• pp.157-158
• /
• 2018

In this study, the current tendency to replace a large amount of material admixture, which is fly ash (FA) and blast furnace slag (BS), into concrete is that high-grade cheese high admixture of high fluidity concrete In consideration of the substitution rate, we considered J-Ring to investigate the influence on the segregation resistance and the method of evaluating the classical segregation. In addition to the admixture replacement rate in the study results, the EIS using J-Ring became lower and the percentage of vehicles with segregation increased. Such a tendency is considered to be positive when J-Ring is used when segregation is judged if segregation degree is similar to EIS using J-Ring.

• 한국건축시공학회:학술대회논문집
• /
• 한국건축시공학회 2019년도 춘계 학술논문 발표대회
• /
• pp.139-140
• /
• 2019

In this study, we considered the influence on segregation resistance at the time of substitution of FA and BS, which are substance admixtures of high fluidity concrete. According to the research results, EIS, which is an index of segregation in high fluidity concrete replacement, showed a low value, and the composition also showed a higher value than OPC. Therefore, it is confirmed that the resistance to segregation at the time of admixture replacement of high fluidity concrete is improved.

• 한국건축시공학회:학술대회논문집
• /
• 한국건축시공학회 2019년도 춘계 학술논문 발표대회
• /
• pp.101-102
• /
• 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
• /
• 한국건축시공학회 2020년도 봄 학술논문 발표대회
• /
• pp.56-57
• /
• 2020

The purpose of this study is to achieve a sufficient fluidity without segregation for normal compressive strength grade concrete mixture. The major obstacle of achieving fluidity of normal compressive strength grade concrete mixture is segregation. Hence, in this research, VMA was used to prevent segregation.

• 한국건축시공학회:학술대회논문집
• /
• 한국건축시공학회 2021년도 봄 학술논문 발표대회
• /
• pp.142-143
• /
• 2021

The purpose of this study is to analyze the extent of the rheology parameters at the segregation boundary of mid-range workability concrete. In addition, it was intended to present the extent of the rheology parameters of the normal strength concrete with segregation resistance using the determination of segregation occurrence of concrete and the use of the rheology parameters. However, it was confirmed that segregation occurs even if the measured rheology parameters is in the range of the suggested rheology parameters. Therefore, it is determined that the conditions under which segregation occurs will provide fundamental data that can be rheological defined. Additional studies are also needed on the relationship between rheological parameters and segregation.

• 한국건축시공학회:학술대회논문집
• /
• 한국건축시공학회 2014년도 추계 학술논문 발표대회
• /
• pp.38-39
• /
• 2014

In this research, the evaluation method of segregation resistance is suggested using the ratio of maximum and minimum values of concrete slump flow. As a result, in the case of normal concrete range from 80 to 210 mm of slump, it is considered that managing the EIS-N value to less than 1.10 is the most favorable for segregation determination.

• 한국세라믹학회지
• /
• 제31권9호
• /
• pp.941-948
• /
• 1994

An underwater grout on material resistance against segregation in water were studied by water soluble polymer (methyl cellulose and acrylic acid ester and styrene). The mechanical properties of the grout agents were investigated through the observation of the microstructure and application of fracture mechanic. When the soluble polymer MC+AAES added with 0.6 wt% to the underwater grout agents the compressive strength, flexural strength and Young's modulus were about 58 MPa, 10 MPa and 3.2 GPa respectively, and critical stress intensity was about 0.8 MNm-1.5. It can be considered that the strength improvement and fracture toughness increase may be due to the pore decrease and bonding force by material resistance against segregation in water.

• 한국건축시공학회지
• /
• 제4권2호
• /
• pp.129-136
• /
• 2004

High fluidity concrete(HFC) requires high dosage of superplasticizer to acquire sufficient fluidity, and high contents of fine powder and viscosity enhancing admixtures to resist segregation. The use of high amount of admixtures to make HFC at batcher plant in ready mixed concrete company is one of the reasons to raise the manufacturing cost of HFC. For this reason, new type of manufacturing method of HFC are described using both flowing concrete method and segregation reducing superplasticizer(SRS) in order to gain economical profit and offer the convenience for quality control.. As dosage of melamine based superplasticizer increases, it shows that fluidity and bleeding increase, while air contents and ratio of segregation resistance decrease. It also shows that addition of viscosity agent into superplasticizer reduce bleeding and improve segregation resistance of concrete. Dosage of AE agent into superplasticizer containing viscosity agent recovers loss of air contents during flowing procedure. Combination of proper contents of superplasticizer, viscosity agent and AE agent make possible to develope segregation reducing type superplasticizer. Compressive strength of high fluidity concrete applying flowing method with it is higher than that of base concrete. No differences of compressive strength between compacting methods are found. For the estimation of construction cost of high fluidity concreting using segregation reducing type superplasicizer, under same strength levels, although material cost of high fluidity concrete is somewhat higher than that of plain concrete due to segregation reducing type superplasticizer cost, labor cost and equipment cost of high fluidity concrete is cheaper than that of plain concrete. However, based on the strength differences, high fluidity concrete shows lower material cost, labor cost and equipment cost than that of plain concrete due to decreasing in size of member and re-bar caused by high strength development of concrete.

• 콘크리트학회논문집
• /
• 제14권3호
• /
• pp.275-282
• /
• 2002

고유동 콘크리트를 제조할 경우는 유동성 향상을 위한 다량의 고성능 감수제와 재료분리를 방지하기 위한 다량의 분체 혹은 증점제로 말미암아 제조비용이 고가이고, 또한 품질관리에도 많은 어려움이 있다. 그러므로, 본 연구에서는 유동성 및 재료분리 저항성이 우수한 고유동 콘크리트를 경제적으로 제조하기 위하여 분리저감형 유동화제의 최적배합비를 결정한 다음, 유동화 공법으로 접근하는 것을 검토하였다. 실험결과로 유동화제 첨가량이 증가할수록 유동성 및 블리딩량은 증가하였고, 공기량 및 재료분리저항성은 저하하는 것으로 나타났다. 따라서, 여기에 증점제를 첨가함에 따라 양호한 유동성에서 블리딩량이 저하하였고, 재료분리저항성도 증대되었는데, 마지막으로 AE제량 증가에 따라 저하된 공기량이 회복되므로써 양질의 분리저감형 유동화제로 최적배합비를 결정할 수 있었다. 경화 콘크리트 특성으로 유동화 공법으로 제조된 고유동 콘크리트의 압축강도는 베이스 콘크리트보다 증가하는 것으로 나타났고, 무다짐 공시체의 압축강도는 표준다짐 공시체의 압축강도와 유사한 것으로 나타나 다짐 방법간의 차이는 없는 것으로 나타났다.