• Journal of Industrial Technology
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• 제31권A호
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• pp.53-57
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• 2011

Recently due to dramatically increasing demand of liquid crystal display (LCD) panel in IT industry, the used LCD panel glass has been wasted from electronic items, and also panel glass of poor quality during manufacturing process. The wasted LCD panel glass was crushed in the range of 0.42 to 2mm and evaluated for its usefulness as a aggregate in production of cement concrete brick. Cement concrete specimens with various mixing ratios of weathered granite soil, LCD panel glass and cement were cured in wetness for 7 days at $40^{\circ}C$ and then tested for uniaxial comprehensive strength (UCS)(KS F 4004 method). Specimen with a mixing ratio, 1:6:3, of weathered granite, LCD panel glass and cement, respectively, showed the highest average in the UCS test($26.51N/mm^2$). It is much higher than that of commercial brick without glass($17.00N/mm^2$). Conclusively waste LCD panel glass can be reutilized economically as a raw building material of good quality.

• Proceedings of the Korean Institute of Building Construction Conference
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• 한국건축시공학회 2013년도 추계 학술논문 발표대회
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• pp.194-195
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• 2013

Recently, it is the tendency that the CO₂ gas generated in the manufacturing process is increased every year in case of the portland cement used in the most of constructions and civil engineering field. The method that uses the mineral admixtures as the cement substitute material in order to be more serious and as much as it occupies 7% of the global CO₂ gas outlet amount such as 1 ton produces the cement and it ejects the CO₂ gas of 0.4~1.0 ton, etc conclude this problem is examined. Therefore, PVA fiber was mixed into the inorganic binder recycling the blast furnace slag, which is the industrial byproduct with the purpose studying the Geo polymer which doesn't use the cement at all silica fume, red mud, and etc. In addition, the water curing temperature was differentiated and the strength characteristic of the curing body tried to be examined.

• Journal of Korean Foot and Ankle Society
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• 제22권1호
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• pp.38-43
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• 2018

Purpose: Treatment of diabetic foot infection due to methicillin-resistant Staphylococcus aureus (MRSA) remains challenging. Applying vancomycin-impregnated cement is one of the best methods of treatment. Vancomycin-impregnated cement has been used worldwide; however, to date, there is a limited number of studies regarding its use. We evaluated the duration of antimicrobial activity of vancomycin-impregnated cement stored at room temperature after manufacturing. Materials and Methods: The vancomycin-impregnated cement was manufactured by mixing 1 g of vancomycin with 40 g of polymer and adding 17.90 g of liquid monomer. The cement dough was shaped into flat cylinders with diameter and height of 6 mm and 2 mm, respectively. Another cement of the same shape without mixing vancomycin was prepared as the negative control. All manufactured cements were sterilized with ethylene oxide gas and stored at room temperature. Each cement was placed on Mueller Hinton agar plate lawned with standard MRSA strain. Standard vancomycin disk and gentamicin disk were placed together. After 24 hours, the diameter of inhibition zone was measured, and if the diameter was less than 15 mm, vancomycin-impregnated cement was regarded as a loss of antimicrobial activity. The study was repeated every 2 weeks until vancomycin-impregnated cements lost their antimicrobial activity. Results: Vancomycin-impregnated cement stored for a duration of 16 weeks created a 14 mm inhibition zone, while vancomycin disk created a 15 mm inhibition zone. Vancomycin-impregnated cement stored for a duration of 17 weeks created 7 mm and 9 mm inhibition zones, while vancomycin disk created 16 mm and 15 mm inhibition zones, respectively. Conclusion: We found a decrease of antimicrobial activity in vancomycin-impregnated cements after 16 weeks. After 17 weeks, they showed definite loss of antimicrobial activity. Therefore, we recommend not using vancomycin-impregnated cement spacers that has been stored for more than 16 weeks at room temperature.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2007년도 춘계학술대회
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• pp.709-712
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• 2007

폐차잔재를 시멘트제조공정의 열원으로 활용하기 위해서는 연료로 사용하기 위한 경제성과 더불어 시멘트제조공정 및 품질 그리고 환경기준을 만족해야 한다. 따라서 폐차잔재의 최적투입방법과 폐차잔재의 연소시 염소물질의 거동특성에 대한 연구가 선행되어야만 한다. 본 연구에서는 이러한 폐차잔재의 시멘트 킬른 현장적용에 따른 위험요소와 시행착오를 최소화하기 위하여 최적 연료화 조건에 대한 전산모사 연구를 하였으며 전산모사의 대상공정으로는 폐차잔재가 투입될 Precalciner와 염소제어를 위하여 Bypass unit가 설치될 Precalciner의 하단부 그리고 Cyclone을 선정하여 입자 및 가스상의 거동 특성을 고찰하였다. 본 연구로부터 폐차잔재의 투입위치로는 현재의 석탄 투입위치를 활용하는 것이 효과적일 것으로 판단되었으며 Precalciner의 하단부에 대한 가스상 및 입자상의 거동특성을 활용하여 Bypass unit를 설치할 최적의 위치를 선정할 수 있었다. 또한 Cyclone의 입자 거동특성 결과로부터 염소 제어를 위한 각 Cyclone의 입자회수율에 대한 정보 및 공정의 개선 가능성을 확인할 수 있었다.

• Journal of the Korean Recycled Construction Resources Institute
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• 제7권1호
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• pp.22-28
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• 2019

Cement is a basic material for the construction industry and it requires high temperature sintering when manufacturing cement. $CO_2$ emissions from raw materials and fuels are recognized as new environmental problems and efforts are underway to reduce them. Techniques for reducing $CO_2$ in concrete are also recommended to use blended cement such as blast furnace slag or fly ash. In addition, the construction waste generated in the dismantling of concrete structures is recognized as another environmental problem. Thus, various methods are being implemented to increase the recycling rate. The purpose of this study is to utilize the inorganic raw materials generated during the dismantling of the structure as a raw material for the low carbon type cement binder. Such as, waste concrete powder, waste cement block, waste clay brick and waste textile as raw materials for low carbon type cement binder. From the research results, low carbon type cement binder was manufactured from the raw material composition of waste concrete powder, waste cement block, waste clay brick and waste textile.

• Journal of the Korea institute for structural maintenance and inspection
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• 제17권3호
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• pp.108-117
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• 2013

Among the byproducts from thermal power plant using coal combustion, fly ash as mineral admixture is widely utilized in concrete manufacturing for its engineering merits. However residuals including bottom ash are usually reclaimed. This study presents an evaluation of engineering properties in cement mortar with pond ash (PA). For this work, two types of pond ash (anthracite and bituminous coal) are selected from two reclamation sites. Cement mortar specimens considering two w/c (0.385 and 0.485) ratios and three replacement ratio of sand (0%, 30%, and 60%) are prepared and their workability, mechanical, and durability performance are evaluated. Anthracite pond ash has high absorption and smooth surface so that it shows reasonable workability, strength development, and durability performance since it has dense pore structure due to smooth surface and sufficient mixing water inside. Reuse of PA is expected to be feasible since PA cement mortar has reasonable engineering performance compared with normal cement mortar.

• Journal of the Korean Ceramic Society
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• 제35권4호
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• pp.371-377
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• 1998

The effect of epoxy resin on the water stability of HAC/PVA based MDF cement composite were stu-died through the three different forming methods calendering extruding and warm pressing. In prexing step the epoxy resin was added in 5-15wt% of cement weight. The 3-point flexural strength of each dry and wet specimen which were immersed in water during 3. 7, 14 days was estmated and the mi-crostructural change of epoxy resin-added MDF cement composite due to water immersion was charac-terized by scanning electron microscopy. As the addition amount of epoxy resin the im-provement of water stability of MDF cement composite was achieved in most case. Especially through the warm press forming method the effectiveness of epoxy resin addition to the water stability was enhanced. When the epoxy resin was added by 5wt% to 7wt% the optimum flexural strength and water stability

• Proceedings of the Korea Concrete Institute Conference
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• 한국콘크리트학회 2008년도 추계 학술발표회 제20권2호
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• pp.521-524
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• 2008

The purpose of this study is to identify the character and condition of Cr in the clinker and thereby contribute to the research for reduction in utilizing Cr in the cement manufacturing process. The concentration of chromium by cement particle size and the distribution of chromium by clinker mineral were measured. Next, correlation was considered between chromium and the soluble components in cement. As a result, in the range that cement particles were 20${\mu}$m or less, highest soluble hexavalent chromium was found. When the concentration of chromium was measured through mineral separation, belite and the interstitial phase were higher in chromium than in alite. soluble hexavalent chromium was contained in domestic cement less than 20ppm, and its conversion ratio was somewhat high as 10 to 40% or so.

• Journal of the Korea Concrete Institute
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• 제17권6호
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• pp.879-884
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• 2005

The setting time is a very important factor affecting the quality of tunnel lining and reinforcement of inclined slope etc. Currently, however, the quality criteria of accelerating admixture to improve it is not established well. In this study, evaluation on setting time measuring methods of cement mixed a accelerating admixture (AA) was performed using Gillmore and Vicat needle test methods. For both test methods, the setting time for addition at a time was better than post addition regardless of initial setting and final setting. For Gillmore needle test method, two types of measuring methods were selected and it is noted that setting time with cement type under the same accelerating admixture can be different. Accordingly, manufacturing company shall develop a less sensitive accelerating admixture to cement type. For Vicat needle test method, six types of measuring methods were used and a proper measuring method of the admixture were proposed as follows: (1) the temperature of materials used shall be controlled exactly and (2) to evaluate its properties, an admixture usage of $5\%$ (ratio of cement weight) is recommended.

• The Journal of the Korea Contents Association
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• 제13권9호
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• pp.392-399
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• 2013

The purpose of this study is to identify the manufacturing possibility of non-cement mortar using blast furnace slag and alkali accelerator. In this experimental study, the blast furnace slag which is the by-product of the steel industry substitute for cement, and the potassium hydroxide(KOH), calcium hydroxide ($Ca(OH)_2$) and sodium hydroxide(NaOH) as stimulus were added to each specimen. And the analysis on reaction property of non-cement mortar was conducted by measurement such as flexural and compressive strength, XRD, EDS and SEM. From the test results, it can be founded that $SiO_2$ and CaO included in the blast furnace slag are released and make the calcium silicate hydrate like the hydration reaction of the cement. Also, the continued study is need to reduce emission of $CO_2$ because of major content in filed of the building construction.