무기질계 혼화재의 혼입률 변화에 따른 시멘트 모르터의 수밀 특성 분석에 관한 연구

柳顯紀,梁富弘 충주대학교 산업대학원 1999 大學院論文輯 Vol.1 No.-

This study is intended to devolop the self waterproof agents for high performance concrete by analyzing the properties of fresh and hardened mortar with various addition rations of the inorganic admixture and zinc stearate. As the results of the test,the flow and air content increase with the addition of expansive. When the replacement rate of silica fume increases, the flow decreases for the increased wiscidity. And the flow and air content decrease with the addition of zinc stearate. At hardened state,the compressive strength, tensile strength and flexual strength decrease with the addition of expansive additives and zinc stearate. With the increase of silica fume's replacement, they show a little decrease at early age and then increase gradually. Also, absorption and permeability show a steep decrease when zinc stearate is added, and a slack decrease with the replacement of silica fume.

폐도자기 분말도 변화에 따른 순환골재 사용 콘크리트의 물리적 특성에 관한 연구

류현기,박정민,정재호,김의창,윤승조,Ryu, Hyun-Gi,Park, Jeong-Min,Joung, Jae-Ho,Kim, Eui-Chang,Yoon, Seung-Joe 한국건설순환자원학회 2011 한국건설순환자원학회지 Vol.6 No.2

본 연구의 목적은 폐도자기 분말도 변화에 따른 순환골재 강도 증진에 관한 연구로 유동성은 폐도자기 분말 치환율이 증가할수록 유동성이 감소하는 경향으로 나타났으며, 공기량은 KS 한도범위를 만족하는 것으로 나타났다. 압축강도는 순환골재 및 폐도자기 분말 치환율이 증가할수록 증가경향이고, 내구성으로 건조수축에 의한 길이변화는 폐도자기 미분말이 커질수록 다소 완만한 건조수축율을 나타내었고, 또한 단열온도상승은 순환골재 대체율 및 폐도자기 미분말이 증가할수록 최고온도에서 약 $6{\sim}10^{\circ}C$정도 낮게 나타내어 수화열에 의한 균열저감 효과를 발휘하였다. 순환골재 사용량을 30%정도 권장 하고 있지만 점토인 폐도자기의 분말도를 조절하여 사용할 경우 순환골재의 다량 사용시에는 콘크리트의 제반성상에 문제가 없을 것으로 판단되었다.

팽창재 치환율 변화에 따른 콘크리트의 팽창 특성에 관한 연구

柳顯記 충주대 산업과학기술연구소 2000 産業科學論文集 Vol.8 No.-

Recently, the expansive additives are used in construction fields in order to reduce the shrinkage cracking occured in concrete structure. Hower, the expansive additives sometimes may be over added due to insufficiency of congnition of constructor, which results the decrease of strength and over expansion. So in this study, the experments are perfomed to present the properties of concrete by varying the unit additions of expansive additives. As the results. The concrete shows a decrease of strength and a increase of cracking with the increase of unit addition of expansive additives which causes the self destrution of concrete specimens.

부순모래 置換率 變化에 따른 콘크리트의 力學的 特性分析

柳顯紀 忠州大學校 1998 한국교통대학교 논문집 Vol.33 No.2

This study aims to present the reference data in efficiency mixing design of concrete using the mixed fine aggregate of the river and crushed sand, through trial mixing. It also aims to analyse the mechanical properties and shrinkage in hardened state. By the test results, the formula of the unite water content is as follows. 1) Substitute Ratio of Crushed Sand 0% : w/c = 0.0909·F + 81.0242 2) Substitute Ratio of Crushed Sand 20% : w/c = -0.1104·F + 86.2807 3) Substitute Ratio of Crushed Sand 40% : w/c = -0.1170·F + 86.5635 And, in mechanical properties of concrete, the compressive strength of the concrete containing crushed sand compared with river sand is lower, tensile strength is higher, and bending strength is the same. Drying shrinkage is increased while the replacement ratio of crushed sand is increaded.

잔골재율 변화에 따른 콘크리트의 특성분석

柳顯紀 충주대 2004 産業科學論文集 Vol.12 No.-

The volume of aggregate in a concrete mixture occupies approximately 70~80 percent of a total volume. Especially, Fine aggregate is important to mix design because it has a lot of effects on a concrete quality. Accordingly, this research that consults list of references mix and sets a standard looking for a proper S/a made a study of a concrete dynamical quality change according to the fluctuation of S/a.

대나무 섬유소를 이용한 섬유보강 콘크리트의 역학적 특성

류현기,권용주,신상용 忠州大學校 2009 한국교통대학교 논문집 Vol.44 No.-

This study is a experiment on the mechanical properties of concrete according to the fiber additional quantity of bamboo. The experiment and analysis results are as the following. The slump as a quality of the concrete not to harden showed to decrease more remarkably for a slump value than the plain according to the increment of cellulose additional rate. Air quantity showed to increase only in 0.2% fiber additional rate and to get out of KS allowable error of bad air content in 0.4% and 0.6%, and capacity mass by unit showed a reverse tendency against air quantity according to the change of cellulose additional quantity. Compression intensity as a quality of hardening concrete showed collectively a tendency to decrease in the remnant past days except only 0.6% at the standard past day 愀8 and the initial 3 days. Pulling intensity showed to increase more than the plain in all past days according to the change of fiber additional quantity of bamboo, and bending intensity also showed to be higher revelation intensity than the plain in the measurement result at the standard past day 28. In the result of length change rate, we can find the bigger the cellulose additional rate as a special quality increased, the more it decreased according to the pass of the past day.

석회석의 분말도 변화에 따른 콘크리트의 특성분석

류현기 충주대학교 2006 한국교통대학교 논문집 Vol.41 No.-

Way that development result resources exhaustion of sudden industry and problem of environmental pollution use industrial wastes that is development and Industrial By-products of new Mineral Admixtures being risen development and examine. Because limestone powder chief ingredients is no damage to cement hydroxides as calcium carbonate and because Powder is very minuteness, viscosity is increase segregation of raw materials and capillary pore pouring effect, effect of watertightness is expected. Also, if limestone powder speech uses cement raplacing materials used of cement because is judged that is going to effect effect economical side and side of environmental pollution as curtailment limestone powder speech grasp concrete special quality to cement replacing materials principal parts data and it is purpose of this research that wish to foretell availability of use possibility.

유해물질의 흡착 및 방향성콘크리트의 활용 가능성 분석

류현기,김홍래 忠州大學校 2010 한국교통대학교 논문집 Vol.45 No.-

Along with the ongoing developments of skyscrapers and large-scale facilities such as administrative and business complexes, there has been growing demand for use of eco-friendly construction materials. One emerging issue is the indiscriminate use of synthetic materials that are almost indistinguishable from their organic counterparts and the harmful gases released from concrete such as formaldehyde, CO2, CO, ammonia, radon gas, hexagon chrome, dust, etc, causing indoor air pollution. The purpose of this study is to develop materials to be used in concrete solution that will effectively reduce the pollutants and change them into fragrances and thus, calculate the possibility of “environment-friendly concrete”. This is done through two types of activated carbon (from coconut and lignum), diffused as chemical substitutions (10% replacement ratio) along with the addition of air freshener (0.02%) of lavender flavor such as coffee, lemon, pine, etc. The test results showed some loss of liquidity in non-solidified concrete due to the strong absorptive characteristics of activated carbon. However, the air content, bleeding level, penetration-resistance and coagulation time were at optimal level, especially more so with the coconut-based active carbon rather than the ligneous. In the case of solid concrete, when active carbon with numerous particle gaps were used as substitute aggregate, it proved to be weaker than the plain concrete. But the good dry shrinkage rate, absorption of the pollutants (formaldehyde, CO2, CO), plus the pleasant fragrances, mean great potential. With further studies and experiments such as lowering W/B and proper use of another admixture to improve the strength, the possibility of industry-grade, eco-friendly concrete is just around the corner.

하수슬러지 소각재를 이용한 시멘트 모르타르의 특성분석

류현기,박정민,Ryu, Heon-Ki,Park, Jeong-Min 한국건설순환자원학회 2010 한국건설순환자원학회지 Vol.5 No.3

This is an experimental research in order to judge the applicability of sewage sludge incineration ash having applied the mixing proportion needed to manufacture bricks and to do plaster work with addition of hwangtoh and slaked lime as a part of the methods for utilizing the wastes produced from sewage sludge incineration ash. Based on the results from experiment and analysis, it is judged that, in case of mixing proportion of 1:2 for the purpose of plastering and masonry work, the cement mortar produced by using a 10% addition ratio of sewage sludge incineration ash with mixture of hwangtoh covering all range of addition ratio, and also the cement mortar produced by using a 20% of sewage sludge incineration ash together with 0% and 10% addition ratio of hwangtoh, was possible to be applied to the practical use. In case of mixing proportion of 1:7 for manufacture of bricks and blocks, if such brick and block products are produced with 10% and 20% addition ratio of sewage sludge incineration ash having added aggregate fines or stone dust that has been actually used in brick and block manufacturing, it is judged that these bricks and blocks could be practically used in the job sites, although strength development is a little bit lower.

태양광 채광시스템의 실태 및 필요성

류현기 한국조명·전기설비학회 2007 조명.전기설비 Vol.21 No.3