• Proceedings of the Korea Concrete Institute Conference
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• 1999.04a
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• pp.481-486
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• 1999

According to results of this research Fly-ash Cement permanent-form production was found to be possible by fly-ash mortal. The compress strength 350kg/$\textrm{cm}^2$, banding strength 120kg/$\textrm{cm}^2$ were possible material separting and bleeding by excessive W/C rate was decreased permanent-form made by polymer solved high price of polymer by fly-ash. Model material was made by result of first research. There were no minute-crack on beam form and out surface of form was very smooth, So filling degree seemed desirable length of form after steaming curing was maintained as expected. with these results production of form seemed possible. In the banding load test, fly-ash showed increase of maxim load 12% than RC. in the case of minute-crack, comparing with RC, fly-ash showed no crack at connect. at the first stage under continuing loading size of crack increased. These phenomena seemed to be based on contribution of stress of inner bars in permanent-form. in the test of defection, fly-ash shower about 10% beam load increase than RC. in the case of beam defection, RC showed sudden decrease of tolerance at maxim load and total breaking, but permanent-form showed breaking of bending maintaining defection with contribution of steel stress ($\Phi$6 wire-mash). There phenomenic seemed to be attributed to increase of surface and steel tolerance of form. According to construction explacemaion, it was guessed that each panel was constructed by conner-steels in form edge. so cohesiveness was small. on these bases. keeping width of horizontal band 30cm, form-panel of 20mm width was found to be of use. Permanent-form was found to be efficient in compressibleness, defection, safety and use of Fly-ash mortal.

• Proceedings of the Korea Concrete Institute Conference
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• 2000.04a
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• pp.47-52
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• 2000

Recently, it is very necessary the development of the manufacturing techniques for high strength concrete(HSC) for the large-scale size and good quality of civil structure. But, the manufacture and quality control of HSC of which shrinkage, heat of hydration and workability at construction filed are considered, is very difficult due to its low water-cement ratio and high quantity of unit cement content. In the present study, we tried to know and assess the influences of chemical and physical properties of cement on the material properties of HSC. We analyzed basic properties of 4 kinds of cement whose chemical and physical properties are different each other through various tests such as chemical analysis and mortal test. Also, we performed the assessment of the material properties of HSC for each dement by the test for the conditions of same mix design and similar compressive strength. From the results in the study, the assessment of the important quality factors of cement influencing the properties of HSC may be utilized to quality control of applied cement to manufacture the HSC of high quality.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2011.05a
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• pp.31-32
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• 2011

The purpose of this study is to investigate the amount of chloride penetration into concrete finishing materials. Chloride ion migration test was used rapid infiltration method proposed by 'NT-Build 492'. The kind of coated finishing material is 'None-finished(N)', 'Cement Mortal(M)', 'Water based paint(P)', 'Bone-Tile(B)', 'Repair Mortal(R1)' in this paper.

• Proceedings of the Korea Concrete Institute Conference
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• 2000.04a
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• pp.173-176
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• 2000

The objective of this paper is to investigate the properties of strength and thermal conductivity of floor cement mortal using copper fiber. Compressive strength thermal conductivity and length change are tested. According to the experimental results, compressive strength, thermal strength and thermal conductivity of mortar using copper finer are shown to be increased with increase of the contents of copper fiber and the aspect ratio. In case of length change of cement mortar using copper fiber also shows deline tendency compared with that of plain mortar.

• Journal of the Korean Recycled Construction Resources Institute
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• v.9 no.1
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• pp.92-99
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• 2021

CaO-based by-products composed of CaO, SO3, Al2O3, etc. are generally used as raw materials for CaO compounds. When applied to the recovered water of ready-mixed concrete, the hydration reaction of the powder material is accelerated and concrete performance can be improved. In this study, activated sludge was prepared to apply to the recovered water of ready-mixed concrete by mixing CaO-based hot-rolled slag(C12A7) in the recycling water of ready-m ixed concrete. Cem ent paste setting time and mortar compressive strength performance tests confirmed the effect on the hydration reaction. Therefore, the possibility of concrete application using activated sludge was confirmed.

• Journal of the Korean Recycled Construction Resources Institute
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• v.7 no.4
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• pp.413-422
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• 2019

A ferrosilicon (FS) by-product was applied into a cementitious binder in concrete substituting the ordinary Portland cement (OPC). The original material characteristic of FS is very identical to silica fume (SF) regarding chemical composition and physical properties such as specific surface area and specific gravity. Therefore, the FS and SF concrete or mortal of which 10% of the material was replaced to total binder weight were fabricated to evaluate the feasibility of using F S as a binder, and the comparative information of OPC, FS and SF concrete was given. The hydration characteristic of FS concrete was analyzed using X-ray diffraction analysis. The FS concrete was beneficial in compressive strength, resistivity against chloride ingress and reducing porosity considering performance of OPC concrete but the advantage was less than using SF. A possibility of alkali-silica expansion was found out from the FS concrete due to the agglomerated size of the silica particles.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.13 no.12
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• pp.2641-2646
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• 2009

The more growing on home automation system at automatic control, the more efficiency required for energy consumption and for recycling energy in near future. Heating is essential in general apartment. Heating method is two types in apartment. One uses electricity, and other one uses warm water. If use electricity, is not efficient by rise of electric charges. But, It can reduce much in expense aspect, if use warm water. When use warm water, temperature of warm water is not equal from all pipe parts. Therefore, indoor tempera can be unequal with set point. Solution of these problems is as following. Temperature sensor in warm water attach pipe. The measured temperature transmits by real time. Temperature of warm water controls in receiver side. In this paper, we propose an automatic temperature transmission system for the heating pipe at home, that is a low-power based, and supply the energy source from a small AC motor resided in bottom cement mortal. The proposed system is used in power mechanism from a collision process of water-jet using propeller water-difference and also designed a CPU module by Atmega8 at ATMEL co., Inc. and a communication module by CC1020 at Chipcon co., Inc.