• Proceedings of the Korea Concrete Institute Conference
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• 2008.11a
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• pp.349-352
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• 2008

The research conducts a four-point loading test by making two reinforced concrete beams(HSCC test specimen and conventional concrete test specimen) in order to apply an HSCC with a normal strength(30MPa) to a structure. Also, it compares and analyzes the characteristics of the flexural behavior of HSCC and conventional concrete. The stiffness and ductility of the test specimens of HSCC and conventional concrete show similar behavior, but HSCC is more effective in crack control than conventional concrete. The result of the research demonstrates that HSCC can be applied in the construction site.

• Magazine of the Korea Concrete Institute
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• v.8 no.2
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• pp.109-117
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• 1996

Recently, High-Workable Concrete has been developed and began to be used to a great extent in foreign countries, but it is not familiar with and fully Introduced in Korea yet. Therefore the aim of this paper is to suggest a reference data. for the development of High-Workable Concrete according to the comparative analysis which were done on the effects of mix proportion(water-binder ratio, sand-aggregate ratio, unit water, a kind of superplasticizer) on the flowing characteristics. And also this paper aims to examine the compactability and segregation resistance of High-Workable Concrete in a mock-up test and in a field test. From the result, we concluded that it is possible to produce and to use the High-Workable Concrete at the construction site.

• Proceedings of the Korea Concrete Institute Conference
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• 2008.11a
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• pp.497-500
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• 2008

This research carries out experiments for hydration exothermic rate and adiabatic temperature rise of concrete to examine the characteristics of the hydration heat of high flowing self-compacting concrete with a normal strength. As a result of the hydration exothermic rate experiment, the high flowing self-compacting concrete that used Lime stone powder and fly ash as polymers shows that its hydration heat amount reduces due to the reduction of unit cement. The result measured the adiabatic temperature rise of concrete presents that high flowing self-compacting concrete having lots of binder contents has a good performance in temperature reduction due to the effect of polymer and that triple adding high flowing self-compacting concrete has a similar temperature rise speed with conventional concrete. As a result of the research, high flowing self-compacting concrete shows a better temperature reduction performance for the binder content per unit than conventional concrete. In addition, it is judged that triple adding high flowing self-compacting concrete with a specified concrete strength 30 MPa is more beneficial in temperature reduction and early hydration heat than double adding high flowing self-compacting concrete.

• Magazine of the Korea Concrete Institute
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• v.10 no.2
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• pp.147-154
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• 1998

고유동 콘크리트의 특성을 판정하기 위한 방법으로서 기존에 알려진 재료분리 판정 방법은 매우 복잡하고 번거로운 실험방법으로 실무 적용에 많은 어려움이 있다. 그런데, 고유동 콘크리트의 유동성 측정 방법에는 슬럼프 플로우를 주로 측정하고, 슬럼프는 변화가 작아서 배제되고 있는 실정이나, 재료분리된 양상을 살펴보면 슬럼프 플로우는 큰 반면, 슬럼프는 작은 양상을 보이고 있다. 따라서 본 연구에서는 고유동 콘크리트의 재료분리 저항성을 슬럼프와 슬럼프 플로우의 조합으로 간단히 평가할 수 있는지 그 가능여부를 검토하고자 하였다. 연구 결과 슬럼프 플로우에 대한 슬럼프의 비는 양호한 재료분리의 평가지표로 이용할 수 있는데, 이 값을 2.5 이하로 유지하면 실무에서의 고유동 콘크리트는 양호한 재료분리 저항성을 관리할 수 있을 것으로 사료된다.

• 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.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.10
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• pp.271-279
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• 2016

This study examines the properties of high-fluidity concrete after adding copper slag as a mineral admixture. For this purpose, the replacement ratio of cement to copper slag was varied to 0, 10, 20, 30, 40, and 50%. A slump flow test, reach time slump flow of 500 mm, and a U-Box and O-lot test were conducted on the fresh concrete. The compressive strength of the hardened concrete was determined at 3, 7, 14 and 28 days. According to the test results, the workability, compaction, and compressive strength of the high-fluidity concrete increased when replacing 30% of the cement with copper slag. These parameters decreased for all material ages with more than 30% copper slag, which was the optimal mixture ratio.

• 레미콘
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• no.9 s.9
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• pp.6-13
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• 1986

본고는 9월 6일 당협회 부산 ㆍ경남지부가 주최한 기술세미나에서 주제 발표한 「시멘트의 수화와 콘크리트의 제성질 」을 발표자인 부산대 오기동 교수가 「콘크리트의 미구조와 강도」로 개제하여 정리한 것이다.

• 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.

• 레미콘
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• no.4 s.87
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• pp.14-21
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• 2006

• Magazine of the Korea Concrete Institute
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• v.8 no.3
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• pp.135-146
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• 1996

In this study, the properties of super flowing concrete containing fly ash were experimentally investigated and compared with those of ordinary concrete. Tests were carried out on five types of super flowing concrete mixes containing fly ash and three types of ordinary concrete mixes without fly ash. Flow test, 0-funnel test, box test, L type test and slump test were carried out to obtain the properties for flowability and workability of fresh concrete. The mechanical properties of hardened concrete were also investigated in terms of compressive strength, splitting tensile strength, modulus of elasticity, creep and drying shrinkage. In fresh concrete, it was found that super flowing concrete had excellent workability and flowability compared with ordinary concrete, and had self-compactable performance. Super flowing concrete *also had good mechanical properties at both early and late ages with compressive strength reaching as high as 40 MPa at 28 days. The creep deformation of super flowing concrete investigated was relatively lower than that of ordinary concrete, but drying shrinkage was much higher.