• Proceedings of the Korean Institute of Building Construction Conference
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• 2018.05a
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• pp.140-141
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• 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.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2018.11a
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• pp.157-158
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• 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.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2019.05a
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• pp.139-140
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• 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.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2019.05a
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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.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2020.06a
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• pp.56-57
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• 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.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2021.05a
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• pp.142-143
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• 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.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2014.11a
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• pp.38-39
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• 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.

• Journal of the Korean Ceramic Society
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• v.31 no.9
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• pp.941-948
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• 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.

• Journal of the Korea Institute of Building Construction
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• v.4 no.2
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• pp.129-136
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• 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.

• Journal of the Korea Concrete Institute
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• v.14 no.3
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• pp.275-282
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• 2002

High fluidity concrete needs high dosage of superplasticizer to acquire sufficient fluidity and high contents of fine powder and viscosity agents to prevent segregation. But it requires high manufacturing cost and has difficult in quality control. Therefore, in this paper, determination of optimal mixture proportion of segregation type superplasticizer for high fluidity concrete and manufacturing high fluidity concrete by applying developed segregation reducing type superplasticizer are discussed using flowing concrete method. According to test results, as dosage of superplasticizer increases, it shows that fluidity and bleeding increase, while air contents and ratio of segregation resistance decrease. It also shows that adding viscosity agent into it reduce bleeding and improve segregation resistance. Dosage of AE agent into it 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.