• Journal of Conservation Science
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• v.30 no.4
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• pp.329-334
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• 2014

A scientific analysis of ancient textiles provides significant data to understand weaving techniques and culture of textiles in each region and charateristics of materials used at that time. In addition, species identification of waterlogged wooden objects is a scientific analysis method that allow us to verify information of relation of foreign species trade and exchange, of preferable species through kinds of wooden products, and of forest environment as well as method setting of conservation. As a result of a species analysis about historical textiles and a wooden comb in a bronze bowl that were excavated from Hapgang-ri, Dong-Myun, Yungi-gun, Chungcheongnam-do, Textile1 and Textile3 are identified as Urticacese Boehmeri nivea ; ramie, Textie2 is identified as Malvaceae Gossypium herbaceum, and a wooden comb is identified as Betulaceae Betula spp. It is expected that this result will help to make further comparative studies, identifying species of textiles and trees of ancient times.

• Proceedings of the Korean Geotechical Society Conference
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• 1999.11c
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• pp.169-178
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• 1999

본 논문에서는 실내에서 실시한 Filtration실험을 통하여 지하수 흐름하에서 이탈한 풍화 잔류토의 세립자가 흙-토목섬유 복합체를 통과하면서 발생하는 이동 (Transportation), 퇴적 (Deposition), 그리고 폐색 (Clogging)되는 과정을 분석하였다. 본 연구에서는 한국의 풍화 잔류토에 적합한 토목섬유 배수재의 새로운 설계기준을 제시함으로써 풍화 잔류토상에 축조되는 터널 구조물 시공시 광범위하게 사용되고 있는 토목섬유재인 부직포의 투수 및 배수특성과 세립토사에 의한 폐색 (Clogging)영향을 분석할 수 있게 되었다.

• Journal of Sericultural and Entomological Science
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• v.30 no.2
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• pp.105-111
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• 1988

견 피브로인과 그 응용에 관한 기초적인 자료를 얻기 위하여, 본 연구에서는, 견섬유와 피브로인막의 구조에 대해서 IR, DSC, X-ray diffraction, SEM, 아미노산분석 등의 조사를 통하여 구조변화를 비교하였다. IR과 DSC를 통하여 얻은 결과, 피브로인 막의 구조는 대부분 random coil과 Silk I type으로 구성되어 있지만, Silk II type의 존재도 인정되었다. 피브로인 막을 전자현미경으로 관찰한 결과, 표면은 구상체로 치밀하게 형성되어 있었고, 단면구조는 거의 대칭적인 것임을 알았다. 견섬유와 피브로인 막의 아미노산 분석결과, 전체에 대한 염기성 아미노산의 함량은 피브로인 막보다 견섬유가 더 많은 것을 알 수 있다.

• Proceedings of the Korean Fiber Society Conference
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• 2001.10a
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• pp.119-122
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• 2001

컴퓨터의 발달에 따라 다른 공업 분야와 마찬가지로 섬유 공업의 많은 부분에서 자동화가 이루어지고 있고, 이에 관련된 여러 연구도 진행되고 있는 가운데 직물의 분해 설계 분야에 있어서는 아직 대부분 수작업이 이루어지고 있다. 이러한 수작업은 많은 시간이 걸리고 측정 방법이나 측정자의 숙련도에 따라 결과가 차이나는 단점이 있다. 현재까지 직물의 화상분석에 대한 연구는 많이 이루어졌고, 실제값과 5％내외의 오차를 보이는 단계까지 이르렀다. (중략)

• Composites Research
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• v.27 no.2
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• pp.52-58
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• 2014

Short fiber reinforced composites manufactured by injection molding have diverse fiber orientations variable with measuring positions even in the same specimen, which is caused by the flow induced fiber orientation. Fiber orientations considerably affect the mechanical and thermal properties of final composite products. In this study, fiber orientation of injection molded carbon fiber reinforced PA6/PPO composite was measured at several points of the specimen by optical microscopy analysis and the corresponding izod impact strength, coefficients of thermal expansion (CTE) were also measured to investigate the influence of local fiber orientation on the mechanical and thermal properties. Izod impact strength where fiber was perpendicular to the direction of crack propagation was higher than where fiber was parallel to the direction, which could be explained be the impact resistance reinforcing mechanism by fiber orientation. CTE was also lower where fiber was parallel to the measurement direction of CTE than where fiber was perpendicular to the direction, which could be also explained by the dimensional stability mechanism by fiber orientation.

• Journal of the Korea Concrete Institute
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• v.27 no.6
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• pp.603-613
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• 2015

In current design codes, minimum shear reinforcement is required for reinforced concrete flexural members, and the use of steel fiber reinforced concrete is permitted to replace the minimum shear reinforcements. In the present study, to estimate the effects of shear reinforcements and fibers on shear strength, simply supported beams were tested under transverse loading. The test results showed that the shear strength was significantly increased by the use of fibers. Particularly, the effect of fiber reinforced concrete was pronounced when high-strength concrete was used. The performance of fiber reinforced concrete for minimum shear reinforcement was evaluated using results of the present study and existing tests.

• Proceedings of the Korea Institute of Fire Science and Engineering Conference
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• 2011.04a
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• pp.170-175
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• 2011

최근 고강도 콘크리트의 내화성능이 사회적 이슈로 부각되고 국토해양부에서 고강도 콘크리트의 내화성능 관리기준(안)이 고시되면서 국내에서도 고강도 콘크리트의 내화성능을 향상시키기 위한 연구가 활발히 진행되고 있다. 본 연구에서는 유기질 섬유인 폴리프로필렌섬유(PP섬유)와 강섬유를 하이브리드한 Fiber Cocktail를 혼입한 고강도 내화콘크리트 개발을 위한 연구를 수행하였다. PP섬유는 $160^{\circ}C$의 온도에서 용융되어 콘크리트 내부에 미세한 통로를 형성하여 고강도 콘크리트 부재 내의 수증기압 및 공극압을 효과적으로 배출하여 고강도 콘크리트의 폭렬발생을 억제시키는 데 효과적이며, 강섬유는 PP섬유가 용융된 후의 고강도 콘크리트 부재의 균열 발생을 억제하며 외부로부터 침투하는 열기를 차단할 수 있다. 100MPa 고강도 콘크리트의 내화실험을 실시하여 최적단면 조건을 도출하기 위해 철근온도를 분석한 결과, 단면이 커질수록 철근온도는 점차 낮아지는 경향이 나타났으며 $600{\times}600mm$, $800{\times}800mm$ 단면에서 내화성능을 확보할 수 있는 것으로 나타났으며, 이중 경제성을 고려할 경우 $600{\times}600mm$ 단면이 최적단면으로 도출되었다. 또한 도출된 $600{\times}600mm$ 단면에 대해서 철근의 온도를 분석한 결과 PP섬유 $1.5kg/m^3$와 강섬유 $40kg/m^3$를 배합한 Fiber Cocktail이 최적배합비로 나타났다.

• Journal of the Korea institute for structural maintenance and inspection
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• v.18 no.1
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• pp.75-83
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• 2014

In order to prevent brittle failure of concrete, steel fiber reinforcement is effective composite material. However ductility of steel fiber reinforced concrete may be limited due to shrinkage caused by large content of cement binder. Chemical prestressing for steel fiber reinforcement in cement matrix can be induced through expansive admixture and this can increase reinforcing effect of steel fiber. In this study, mechanical performances in concrete with CSA (Calcium sulfoaluminate) expansive admixture and steel fiber reinforcement are evaluated. For this work, steel fiber reinforcement of 1 and 2% of volume ratio and CSA expansive admixture of 10% weight ratio of cement are added in concrete. Mechanical and fracture properties are evaluated in concrete with steel fiber reinforcement and CSA expansive admixture. CSA concrete with steel fiber reinforcement shows increase in tensile strength, initial cracking load, and ductility performance like enlarged fracture energy after cracking. With appropriate using expansive admixture and optimum ratio of steel fiber reinforcement, their interactive action can effectively improve brittle behavior in concrete.

• Journal of the Korea Concrete Institute
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• v.23 no.4
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• pp.461-469
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• 2011

In this study, the effect of polyvinyl alcohol (PVA) fiber volume fraction on the pullout behavior of structural synthetic fiber in hybrid structural synthetic fiber and PVA fiber cement composites are presented. Pullout behavior of the hybrid fiber cement composites and structural synthetic fiber were determined by dog-bone bond tests. Test results found that the addition of PVA fiber can effectively enhance the structural synthetic fiber cement based composites pullout behavior, especially in fiber interface toughness. Pullout test results of the structural synthetic fiber showed the interface toughness between structural synthetic fiber and PVA fiber reinforced cement composites increases with the volume fraction of PVA fiber. The microstructural observation confirms the incorporation of PVA fiber can effectively enhance the interface toughness mechanism of structural synthetic fiber and PVA fiber reinforced cement composites.

• Proceedings of the Korean Fiber Society Conference
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• 1999.04a
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• pp.53-56
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• 1999