• Title/Summary/Keyword: High fluidity concrete

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The Execution and Estimation of Construction Cost of High Fluidity Concrete Applying Flowing Concrete Method (유동화공법에 의해 제조한 고유동 콘크리트의 시공 및 원가분석)

  • Han, Min-Cheol
    • 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.

A Fundamental Study on the Estimation of Construction Cost of High Fluidity Concrete Applying Flowing Concrete Method (유동화공법에 의해 제조한 고유동 콘크리트의 원가분석에 관한 기초적 연구)

  • 한민철;손성운;오선교;김성수;한천구
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2002.11a
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    • pp.99-102
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    • 2002
  • This paper discusses the estimation of construction cost of high fluidity concrete using segregation reducing type superplasicizer with 350kgf/cm2 of design strength and 60$\pm$5cm of slump flow in order to verify the cost down effect of high fluidity concrete compared with that of plain concrete with 350kgf/cm2 of design strength and 18cm of slump and with 210kgf/cm2 of design strength and 15cm of slump. According to research, 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, 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.

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Evaluation of the Flowability of the Heavyweight Concrete using Magnetite Powder and Copper Slag as Fine Aggregate (자철석 분말 및 동슬래그를 잔골재로 활용한 중량 콘크리트의 유동성 평가)

  • Moon, Hoon;Kim, Ji-Hyun;Chung, Chul-Woo;Lee, Jae-Yong
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2018.05a
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    • pp.195-196
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    • 2018
  • The Research is underway to utilize heavyweight concrete for various applications. One of them is to use heavy concrete as a marine concrete such as a breakwater to resist wave. Marine concrete is often complex in shape and requires high fluidity. When the heavyweight concrete is high fluidity, there is a high risk of segregation due to the high density of the coarse aggregate. Therefore, we evaluate the fluidity of heavyweight concrete using heavy fine aggregate. As a result of the fluidity evaluation of the heavyweight concrete, the fluidity of the heavy fine aggregate was similar to that of ordinary concrete. Therefore, it is considered that the use of heavy fine aggregate in the development of high fluidity heavyweight concrete will be one of the methods.

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A Study on the Quality Properties of Exposed High Fluidity Concrete using Fly Ash and Limestone Powder (플라이애시 및 석회석 미분말을 사용한 고유동 노출 콘크리트의 품질특성에 관한 연구)

  • Choi, Yun-Wang;Oh, Sung-Rok;Kim, Ji-Hoon;Kim, Kyung-Hwan
    • Journal of the Korean Recycled Construction Resources Institute
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    • v.1 no.1
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    • pp.67-75
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    • 2013
  • Recently, the interest is increasing about the exposed concrete, accordingly, exposed concrete is expanding the use. However, concrete structures is difficult to apply the general concrete for exposed concrete, due to complex section and compact reinforcement, increasingly. Therefore, in this paper, for application of high fluidity concrete as exposed concrete, exposed high fluidity concrete using fly ash and lime stone powder was manufactured and observed quality property(fluidity properties, mechanical properties and Surface Properties) of exposed high fluidity concrete. The experiments are based on the OPC and LSP10, was evaluated Impact on the quality of concrete according to mixing ratio of FA(0, 10, 15 and 20). As a result, fluidity properties, mechanical properties and Surface Properties of exposed high fluidity concrete were satisfied to requirement conditions, fluidity and surface finishability was improved depending on mix of fly ash and limestone powder. Through this, we utilize of basic research data for development of high fluidity concrete for exposed concrete.

A Fundamental Study on the Properties of High-Fluidity Concrete Using Viscosity Agent - Properties of Hardened Concrete - (증점제를 이용한 고유동콘크리트의 특성에 관한 기초적 연구 -경화상태의 특성-)

  • 김기철;박상준;조병영;윤기원;최응규;한천구
    • Proceedings of the Korea Concrete Institute Conference
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    • 1996.04a
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    • pp.198-201
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    • 1996
  • The purpose of this study is to analyze the properties of high fluidity concrete using the viscosity agent of a cellulose system with W/C of 35~50% in hardened state. It is proven that properties of high fluidity concrete in hardened state is nearly the same with normal concrete in the same W/C and no strength difference by tamping method do not appeared. Therefore, no tamping method is thought to be reguired in high fluidity concrete.

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Evaluation of Filling Performance of Steel Concrete Panel (SCP) Mock-up Member with Low-binder based High-fluidity Concrete (저분체 기반 고유동 콘크리트의 Steel Concrete Panel Mock-up 부재 충전 성능 평가)

  • Park, Gi Joon;Park, Jung Jun;Kim, Sung Wook
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.39 no.4
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    • pp.477-483
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    • 2019
  • Recently, precast type SCP modules are being used instead of PSC structures in order to reduce the construction period and costs of special structures such as nuclear power plants and LNG storage tanks. The inside of the SCP module is connected with a stud for the integral behavior of the steel and concrete, and the use of high fluidity concrete is required. High fluidity concrete generally has a high content of binder, which leads to an increase in hydration heat and shrinkage, and a problem of non-uniform strength development. Therefore, in this study, fluidity and passing performance of high fluidity concrete according to material properties are investigated to select optimum mix design of low binder based high fluidity concrete. Mechanical properties of high fluidity concrete before and after pumping are examined using pump car. The filling performance of SCP mock-up members was evaluated by using high fluidity concrete finally.

A Study on Fluidity ability, Filling ability Properties of High Fluidity Concrete with Illite Powder (일라이트 미분말을 혼입한 고유동 콘크리트의 유동성 및 충전성에 관한 연구)

  • Lee, Dong-Un;Lee, Maeng-Gyo;Park, Hyun-Jung
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.16 no.12
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    • pp.8363-8369
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    • 2015
  • This study is to be investigate properties of workability, compacting and compressive strength replaced by the illite powder in high fluidity concrete. For this purpose, illite powder has replaced the binder of high fluidity concrete of 5%, 10%, 15%, 20%. After concrete mixing, slump flow test, reach time slump flow 500mm, O-lot test were conducted on fresh high fluidity concrete. And compressive strength was determined 28 days for the hardened high fluidity concrete specimens. According to the test results, the workability, filling height of high fluidity concrete were increased in 10% replacement of illite powder. Furthermore, the compressive strength of high fluidity concrete was increased in 10% replacement of illite powder.. It was possible to confirm that optimal mixture ratio of illite powder seems to exist, and it is shown to be 10% according to our experimental results.

Determination of Optimal Mixture Proportion of Segregation Reducing Type Superplasticizer for High Fluidity Concrete (고유동 콘크리트용 분리저감형 유동화제의 최적배합비 결정)

  • 한천구;김성수;손성운
    • 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.

Analysis of Possibility of Reduction of Formwork Leakage of High Fluidity Mortar by Inject Accelerator (급결제의 인젝터 주입이 고유동 모르타르의 거푸집 누출량 저감 가능성 분석)

  • Lim, Gun-Su;Han, Jun-Hui;Hyun, Seung-Yong;Kim, Jong;Han, Min-Cheol;Han, Cheon-Goo
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2022.11a
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    • pp.21-22
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    • 2022
  • High fluidity concrete has excellent workability, and if the cross-section of the building is complicated, it is possible to place good quality concrete and increase the construction speed, so its utility value is very high. However, it is premised on the accuracy of concrete formwork assembly. Concrete leakage through formwork gaps is an important consideration when applying high flow concrete. In order to quickly solve the leak of high fluidity concrete caused by formwork gap occurring at the site by accelerator injection, we proceeded with research to confirm the possibility of reducing the amount of formwork leakage of high fluidity mortar. It was confirmed that the injection of the accelerator could reduce the amount of mortar leakage.

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The Properties of Semi-High-Fluidity Concrete with the Variation of Replacement Ratio of Fly-Ash (플라이애쉬 치환율 변화에 따른 준고유동 콘크리트의 특성)

  • 유호범;김기철;윤기원;이정희;한천구
    • Proceedings of the Korea Concrete Institute Conference
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    • 1998.10a
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    • pp.287-290
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    • 1998
  • Recently great efforts and investment have been made in order to achieve economical production by applying new methods like minimization of man-power into construction field. Therefore in this study, we have been focused on the development and practical using of semi-high-fluidity concrete with viscosity agent and fly-ash, also we find out the optimum mix proportions to accomplish good quality semi-high-fluidity concrete. The results of this study show that semi-high-fluidity concrete with viscosity agent of 0.03~0.1%(W$\times$%) and the ratio of fly-ash replacement of 10~20% in W/B of 35~45% has better performance than the high-fluidity-concrete.

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