• 한국건설순환자원학회논문집
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• 제7권4호
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• pp.128-135
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• 2012

ALC는 경량이며 단열 및 차열 등의 성능이 우수한 반면 낮은 강도로 인한 모서리부의 취성파괴가 발생하기 쉬우므로 운반 및 취급 시 상당한 주의를 요구한다. 본 연구에서는 ALC의 물리적 성능개선을 위해 메타카올린 및 실리카퓸 등의 혼화재나 규석 분말 및 석고의 혼입율을 조절하여 제조한 ALC의 성능을 평가하였다. 연구결과 메타카올린이나 규석 분말의 혼입율이 18%인 경우 강도의 개선이 현저하였다. 이와 같은 결과는 공극의 충전효과에 의한 것으로 강도는 개선되나 밀도가 증가하므로 밀도를 낮추면서 강도를 개선할 수 있는 배합이나 제조법에 대한 연구가 필요하다.

• 한국소음진동공학회논문집
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• 제20권7호
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• pp.651-657
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• 2010

Previous experimental results performed by many researchers for a couple of decades in South Korea have shown that an absorbing sheet inserted in a conventional floating slab system for thermal insulation or vibration absorption may amplify the vibration of the slab system at specific frequency ranges depending on the material properties of the sheet. The amplified vibration, consequently, results in the heavy weight floor impact noise exceeding the sound level limit for an apartment house, 50 dB. In this study, the amplification mechanism is examined through numerical analysis and a new slab system is proposed to reduce the amplification and control the noise. The new slab system consists of studs connecting the base slab and upper concrete finishing yielding the dramatically increased stiffness of the slab. The numerical simulation is performed to investigate the effect of the slab system with studs on the vibration and noise control. The results show that the performance of the slab is sensitive to the number and location of studs, and the heavy weight floor impact noise can be reduced up to 6~7 dB compared to the conventional slab system at the optimal stud location.

• 한국산학기술학회논문지
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• 제19권1호
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• pp.666-671
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• 2018

허니콤 판재(honeycomb panel)는 벌집 모양의 코어(core) 양쪽면에 표면판재를 부착시켜 만든 판재이다. 허니콤 판재는 비강도가 뛰어나며, 재료에 압축하중이 가해졌을 때 재료가 수차례의 좌굴을 반복하기 때문에 에너지 흡수성이 우수하여 내충격성이 요구되는 부위에 사용하기에 적합하다. 특히 최근에는 수송기기의 경량화에 대한 요구가 증가함에 따라 알루미늄 허니콤 판재를 자동차 및 고속전철 등의 차체 재료로 이용하려는 연구가 진행되고 있다. 이 밖에도 허니콤 판재는 흡음성과 평활성이 우수하며, 단열성과 내피로성도 우수하다. 연료 경제성을 증가시키기 위하여 알루미늄 합금 소재와 같은 경량 소재를 허니콤 판재 주 재료로 사용하여 무게를 감량시키는 것에 관한 연구를 진행 하였다.본 연구에서는 허니콤 판재의 설계기술, 알루미늄 허니콤 코어 및 허니콤 판재 제조 기술에 대한 연구를 수행하였으며, 또한 제조된 허니콤 판재의 각종 기계적 특성평가를 행하여 그 결과를 바탕으로 알루미늄 허니콤 판재의 제조 공정 설계, 판재 제작 및 특성 평가방안을 마련하였다. 연구결과 허니콤 판재의 우수한 에너지 흡수성은 코어 버클링의 반복에 기인하며 압축강도가 높을수록 접합면적당 강도 또한 높은 값을 나타내었다.

• 한국산업보건학회지
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• 제24권2호
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• pp.122-129
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• 2014

Objectives: Because of its properties such as resistance to heat, chemicals and corrosion; tensile strength; sound absorption; and affordable price, asbestos has been widely used as a building material, fire resistant and retardant, thermal and heat insulator, soundproofing material, and electrical insulation. Since the prolonged inhalation of asbestos can cause serious illnesses such as lung cancer, mesothelioma, and asbestosis after an incubation period of 20 to 40 years, the mineral was classified as a Group 1 carcinogen by the International Agency for Research on Cancer, an intergovernmental agency forming part of the World Health Organization. Children and infants are more at risk than are adults if they are exposed to carcinogens, due to aweaker immunity that has not yet been fully developed. Most childcare centers are operated all day and children tend to spend a great amount of time in the centers. This is why it is important for them to be systematically isolated from environments that may expose them to asbestos. Materials: In order to understand both indoor and outdoor hazards to which children may have been exposed, the study focused on actual surveys of asbestos used in childcare centers, paying special attention to slate-roofed buildings in the vicinity of the centers. Results: A survey of a total of 211 childcare centers showed that the buildings of 18.1% of the centers contained asbestos, with 60.53% of the material being found in classroom ceilings. "Tex" was the most used material for ceilings, making up 89.47% of all ceilings. An outdoor survey showed that childcare centers in Daegu Metropolitan City had an average of 143 slate-roof buildings within a distance of 1km. Conclusions: Buildings housing mainly toddlers, children, teenagers and others more vulnerable to the toxicity of asbestos are not subject to asbestos investigation by law. A legal and practical basis for asbestos control is required for such buildings. In particular, housing materials which contain asbestos in day care centers require asbestos control. GIS should be used to identify the location of buildings with slate roofing materials in the vicinity of daycare centers in order to gauge toxicity of exposure to asbestos caused by potential asbestos friability possibility in outdoor conditions.