• Proceedings of the Korea Concrete Institute Conference
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• 1998.10b
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• pp.916-921
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• 1998

This study describes the result for the placement of the super flowing concrete(SFC) in under-pinning-top-slab which is located Inchon subway section 1-10 where, due to heavy reinforcements and limited working space, it was difficult to place concrete. After placing 600㎥, smooth construction and quality control were possible due to the good flow-ability, self-fillingability, and the resistance of segregation of the SFC itself. Furthermore, economical efficiency was obtained through not only the reduction of the works, labors, and site noise but also the efficient construction control. Because of the crack prevention, high strength, and a fine concrete surface, this study could be considered as a momentum to be adopted generally for applying the proposed method to the difficult subway construction area in the near future.

• Proceedings of the Korea Concrete Institute Conference
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• 1996.10a
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• pp.276-282
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• 1996

This study dealt with the properties for fly ash of combined heat power plant and application for concrete industry. For this purpose, fly ash of ulsan combined heat power plant was analyzed for physical and chemical properties and tested the properties of the super flowing concrete. As results of fly ash, contents of SiO2 and Al2O3 in the fly ash of Ulsan were less than those of thermal power plant(Boryung), but contents of CaO were ten times as much as those of Boryung. In order to satisfy the properties of the Super Flowing Concrete using class C fly ash, mixing conditions were determined the optimum water-binder(w/b), volume ratio of fine aggregates(Sr) and coarse aggregates(Gv).

• Proceedings of the Korea Concrete Institute Conference
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• 1997.04a
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• pp.278-284
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• 1997

This study dealt with the flowing properties of the super flowing concrete for class F fly ash producted thermal power plant and the application for concrete industry. For this purpose, fly ash is analyzed for confined water ratio($\beta_p$)and the super flowing concrete is tested the flowing properties including flowing velocity, funneling time, height difference of box test and compressive strength. As the result, in order to satisfy the flowing properties of the super flowing concrete using class F fly ash, the optimum mixing conditions are determined water-bindrer ratio 37$\pm$2%, volume ratio of fine aggregates(Sr) 47$\pm$2% and coarse aggregates(Gv) 51$\pm$1%.

• Proceedings of the Korea Concrete Institute Conference
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• 1997.04a
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• pp.285-291
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• 1997

This study is the experimental results on the applicability of the super flowing concrete, which is the pre-cast concrete, to various cases. The primary purpose of this study is to verify the demolding strength, the handling strength of the super flowing concrete at various curing conditions, and the site quality control of the DWS (Daewoo Multi-Room Modular Construction System). From the experimental works, required strength and curing cycles are satisfied. Furthermore site quality control details and quality of the pre-cast concrete using the super flowing concrete are obtained. From now on, this study may suggest how to apply the super flowing concrete for common circumstance.

• Proceedings of the Korea Concrete Institute Conference
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• 1997.04a
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• pp.210-219
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• 1997

This research which lays emphasis on ready mixed concrete standard 25-210~240kgf/$\textrm{cm}^2$ shows the influence caused by the ratio of ingredients of superplasticized concrete, and the flowing and strength development of mortar and concrete according to the ratio of ingredients. This research shows that flowability, compactability, and segregation resistivity are the best condition under the following ratio of ingredients: fly ash 30%, unit binders 490~510kg/$\textrm{m}^3$, unit weight of water 184~194kg/$\textrm{m}^3$, fine aggregate ratio 49~51%, and superplasticizer 1.1~1.5%. Following this ratio of ingredients, the reinforced concrete structures to need design strength 25-210~240kgf/$\textrm{cm}^2$ can apply to complicated constructions.

• Proceedings of the Korea Concrete Institute Conference
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• 1996.10a
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• pp.283-289
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• 1996

In this paper, the mix design of the super flowing concrete is described with respcet to basic concept, confined water ratio($\beta_p$), volume ratio of water-binder(w/b), volume ratio of fine aggregates($S_r$) and coarse aggregates($G_v$). The primary purposes of this study are to evaluate the effects of cementitious materials(fly ash, slag cement, portland cement), mixing factors ($\beta_p$, w/b, $S_r$, $G_v$)., and to propose the mix design method of the super flowing concrete. As results of this study, confined water ratio($\beta_p$) of cementitious materials is very high (0.99~1.1), and then the ranges of the optimum mixing factors to be satisfied with the super flowing concrete are $S_r$ 47$\ell$ 2%, $G_v$ 52$\ell$ 1%.

• Proceedings of the Korea Concrete Institute Conference
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• 2006.11a
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• pp.489-492
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• 2006

Needs for the new technologies and cutting-edge Ultra Flowing Self-Compacting Concrete are emerging as the concrete structures are becoming bigger and more specialized recently. In North America and Europe, SCC, which has high resistance against flow ability and segregation, is being used as concrete material in applications such as precast and prestressed bridges, where reinforcing bars are overcrowdedly placed. In Korea, SCC has been utilized limitedly in building structures but its utilization should be expanded to engineering structures such as bridges. In this study, for the application in precast and prestressed bridges with overlycrowded reinforcing bars, USCC was mixed with admixtures to give a binary system and a ternary system according to the 1st grade rules by JSCE (Japan Society of Civil Engineers). Compressive strength and splitting tensile strength of the resulting USCCs were tested. Elastic modulus were compared with the values suggested in CEB-FIP code and ACI 318-05.

• Proceedings of the Korea Concrete Institute Conference
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• 2006.11a
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• pp.401-404
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• 2006

This study is the part of the investigation of the state of the art in ultra high flowing concrete (UHFC), applied in practical field construction, in order to develop the technology for improving workability. This paper includes a brief introduction of water content variance properties in UHFC before and after the pumping operation. Test showed that water content in all parameters decreased after the pumping. This is due to the increase of an absorption ratio of coarse aggregate by the pressure of the pumping operation. thus decreasing the water content. Therefore it should be considered to find out the possibility, which can improve the workability, suffering from over viscosity by the lower water content, in field construction.

• Journal of The Korean Society of Agricultural Engineers
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• v.47 no.1
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• pp.25-32
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• 2005

This study was performed to evaluate strengths and non-destruction properties of super flow concrete using recycled coarse aggregate. At the curing age of 28 days, the compressive strength was 22.7-37.5 MPa, the splitting tensile strength was $2.65\~3.73$ MPa, the flexural strength was $5.78\~6.86$ MPa, the ultrasonic pulse velocity was $3,103\~3,480$ mis, the dynamic modulus of elasticity was $3.401{\times}104\~4.521{\times}104$MPa, respectively. The strengths, ultrasonic pulse velocity and dynamic modulus of elasticity of super flow concrete were decreased with increasing the content of recycled coarse aggregate. The super flow concretes using recycled coarse aggregate were improved by substitution in the range of less than the fly ash content 30010 and recycled coarse aggregate content $75\%$.

• Bulletin of the Korean Space Science Society
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• 2003.10a
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• pp.67-67
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• 2003

적외선 고감도천문관측 등 우주탑재체에서의 천문관측에서는 망원경 또는 관측용 센서를 4K 또는 그 이하로 냉각하여 고감도 관측을 하고 있다. 이와 관련하여 액체헬륨-4, 초유동헬륨, 액체헬륨-3, magnetic cooling 또는 dilution refrigeration 등의 방법으로 4K∼0.05K 영역까지의 극저온을 얻을 수 있다 우주탑재체에서의 극저온을 발생하는 방법과 본 연구실에서 개발 중인 ∼1K 까지의 극저온 발생장치의 설계 등에 관하여 논의한다.