• Journal of Ocean Engineering and Technology
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• v.13 no.3B
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• pp.56-64
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• 1999

An experimental study was carried out to examine the structural behavior of reinforced concrete deep beams strengthened with aramid fiber sheets, carbon fiber sheets and plates, and to propose the reasonable strengthening method for the deteriorated R.C. deep beams. Results show that the most significant differences in behavior of reinforced concrete deep beams strengthened with fiber sheet and plate were mainly due to various fiber orientations and anchorage. Deep beams diagonally strengthened with carbon fibers show better performance compared with those of vertically, horizontally strengthened specimens and produce the increase in the shear resistance through the redistribution of internal forces after the initial cracks occur. However, strengthened deep beams without anchorages might show unreasonable, brittle peeling-off failure of fiber reinforcements.

• Carbon letters
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• v.19
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• pp.47-56
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• 2016

In this study, the fracture behavior of a thermoplastic-modified epoxy resin reinforced with continuous carbon fibers for two levels of fiber-matrix adhesion was performed. A carbon fiber with commercial sizing was used and also treated with a known silane, (3-glycidoxy propyl trimethoxysilane) coupling agent. Toughness was determined using the double cantilever test, together with surface analysis after failure using scanning electron microscope. The presence of polysulfone particles improved the fracture behavior of the composite, but fiber-matrix adhesion seemed to play a very important role in the performance of the composite material. There appeared to be a synergy between the matrix modifier and the fiber-matrix adhesion coupling agent.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2003.10a
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• pp.242-245
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• 2003

The purpose of this study is to investigate the shear modulus, the shear strength at failure and the failure process of QLS(quadruple-lap shear) Test specimen were made of two different fiber contents CFRR and HTPB based polyurethane matrix. The CFRR specimen were prepared with 6.16% chopped carbon fiber and 11.6% chopped carbon fiber. We carried out the shear tests for three types of specimen. The shear modulus and strength of the CFRR was inspected with the increasing contents of chopped carbon fiber. In the other hand the shear strain of the CFRR was inspected with the decreasing contents of chopped carbon fiber.

• KCI Concrete Journal
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• v.14 no.4
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• pp.161-169
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• 2002

The mechanical properties of fiber reinforced porous concrete for use as a planting material were investigated in this study. Changes in physical and mechanical properties, subsequent to the addition of carbon fiber and silica fume, were studied. The effects of recycled aggregate were also evaluated. The applicability as planting work concrete material was also assessed. The results showed that there were no remarkable changes in the void and strength characteristics following the increase in proportion of recycled aggregate. Also, the mixture with 10% silica fume was found to be the most effective for strength enforcement. The highest flexural strength was obtained when the carbon fiber was added with $3\%$. It was also noticed that PAN-derived carbon fiber was superior to Pitch-derived ones in view of strength. The evaluation of its usage for vegetation showed that the growth of plants was directly affected by the existence of covering soil, in case of having the similar size of aggregate and void.

• 한국신재생에너지학회:학술대회논문집
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• 2011.05a
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• pp.92.1-92.1
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• 2011

고분자 전해질 연료전지 (PEMFC)의 핵심 부품 중의 하나인 Bipolar Plate (분리판)을 제조하기 위해서 고분자/그라파이트 복합재료를 사용하였다. 고분자 매트릭스로는 경화시 뛰어난 화학적, 기계적 특성을 갖는 에폭시를 채택하였고, 전기 전도성을 부여하기 위해 그라파이트를 도입하였으며, 에폭시 수지의 내충격성을 향상시키기 위해서 Carbon Fiber를 채택하였다. 에폭시 분말과 그라파이트 분말, 그리고 1cm 정도의 길이를 갖는 Carbon Fiber을 믹서에 넣고 균일하게 혼합하였다. 이 혼합물을 이형제 처리된 몰드에 주입하고, Hot Press를 사용하여 가열, 가압 ($150^{\circ}C$, 4 ton/$cm^2$, 2시간)하면서 경화시켰다. 일정 비율로 고정된 에폭시/그라파이트 계에 Carbon Filber의 혼합 비율을 변화시키면서 전기적, 물리적 성질의 변화를 연구하였다.

• Proceedings of the Korean Society For Composite Materials Conference
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• 2002.10a
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• pp.131-134
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• 2002

Braided carbon fiber reinforced Al matrix composites were developed and characterized. Braided carbon fiber preforms with braiding angles of $30^{\circ}$, $45^{\circ}$ and $60^{\circ}$ were manufactured by using a braiding machine. The manufactured braided carbon fibers were used as reinforcement to fabricate Al matrix composites by employing a pressure infiltration casting method. In the processing of pressure infiltration casting, important processing parameters such as melting temperature, preheating temperature of preform and applied pressure were optimized. Prediction of elastic constants on composites was performed by using the volume averaging method, which utilizes the coordinate transformation and the averaging of stiffeness and compliance constants based upon the volume of each reinforcement and matrix material. The elastic moduli of composites were evaluated by using Resonant Ultrasound Spectroscopy(RUS) method and compared with the elastic moduli obtained from static tensile test method.

• Proceedings of the Korea Concrete Institute Conference
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• 1996.04a
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• pp.418-421
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• 1996

Carbon Fiber Sheet is very attractive for the upgrading damaged reinforced concrete due to its good tensile strength, handabilbity and resistance to corrosion. This paper discusses the applicability of continous carbon fiber sheet for a reinforcement of existeing reinforced concrete structure located in Pusan. Examples of site data and actual concrete rehabilitation project at slab structure related to construction method used carbon fiber sheet will be given.

• Proceedings of the Korea Concrete Institute Conference
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• 1991.10a
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• pp.99-106
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• 1991

Result of an experimental study on the manufacture, the mechanical properties and waterightness of pitch-based carbon fiber reinforced fly ash.cement composites are presented in this paper. The carbon fiber reinforced fly ash.cement composites using early strength cement, silica powder and a small amount of stylene butadiene rubber latex are prepared with carbon fiber, foaming agents and mixing conditions. As a result, the mechanical and plysical properties such as compresive, tensile and flectural strengths, watertightness and cement composites are improved by using a small amount of stylene butadiene rubber latex.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.27 no.4
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• pp.178-185
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• 2017

Carbon fiber frames are actively developed for developing carbon fiber frames as the material of the next generation of bicycle frames, and are currently being developed with carbon fiber frames, hardness, shock absorption, light intensity, and strength. The carbon fiber bike models require a premium, differentiated design concept, which is essential to the development of a conceptual and differentiated design, requiring the development of essential structural structures, safety and refinement, and more of their own identity. In this study, a personal and unified image was derived from the research of the needs of consumers and image analysis process and then in the practical design work, the road bike bicycle frame design was proposed targeting the frame on the basis of carbon fiber materials.

• Resources Recycling
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• v.26 no.6
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• pp.20-28
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• 2017

The direct tensile strength of the mortar specimen containing pitch-based carbon fiber was ranged between 1/27~1/22 as compared to the average compressive strength of mortar. It was found that the direct tensile strength of the mortar containing the same amount of PAN-based carbon fiber was around 1/15. While the case of the control specimen without the carbon fiber was around 1/29. One the other hands, the flexural tensile strength of the mortar containing pitch-based carbon fibers was about 1/12 as compared to the average compressive strength. In case of the mortar specimen with PAN-based carbon fiber and control mortar were 1/10 and 1/13.5, respectively. The tensile performance of the mortar with pitch-based carbon fiber was found to be intermediate between control mortar and the reinforced mortar incorporated with the PAN-based carbon fiber.