• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1998년도 봄 학술발표회논문집(II)
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• pp.613-617
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• 1998

This study deals with the effect on adhesive strength properties of fiber sheet layer and maintenance position of coccrete structure reinforced using epoxy resin carbon and aramit fiber sheet. Properties of epoxy resin adhesive strength of the concrete bridge slab, tunnel and wall etc. reinforced using fiber sheet under many different environment change according to condition of concrete substrate, temperature, moisture, curing, cleaning, and chemical effects and so on. The purpose of this study is that it makes the estimation value of adhesive strength of concrete substrate and fiber sheet reinforcing layer penetrated epoxy resin under high temperature(9$0^{\circ}C$), chemical attack and condition of curing.

• 한국구조물진단유지관리공학회 논문집
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• 제1권1호
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• pp.65-73
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• 1997

In this paper, It is the effect of using fiber sheet (Carbon Fiber Sheet & Aramid Fiber Sheet) and Steel Plate for reinforced concrete beam. 25 specimens are tested, 16 specimens are for bending capacity and the other are for shear capacity. In the case of bending testing, the kind and quantity of the reinforcement materials, the bondage and the existence of crack were selected as experimental variables. In the case of shear testing, It is testified the effect of reinforcement with the variables of the method of reinforcement (side type and U type). As a result, Using the reinforcing materials can increase the capacity of bending and shear stress.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2005년도 추계 학술발표회 제17권2호
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• pp.259-262
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• 2005

This paper deals with the shear strengthening effect of RC beams strengthened with carbon fiber sheets. Fifteen strengthened RC beams(including control beam) were experimentally evaluated to determine improvements in shear strength. The major parmeters of experiment variables are fiber sheet strengthening ratios and strengthening methods of fiber sheet(I-S, I-W, U-S, U-W type). Reinforced concrete beams strengthened with carbon fiber sheets were tested under the combined control of load. Considering strengthening ratios and strengthening methods of fiber sheet, shear capacity and failure mode of test specimens were evaluated. The results show that shear capacity of beams strengthened with fiber sheet is about $28.82\%$ in IS type, $20.49\%$ in IW type, $26.04\%$ in US type, $28.70\%$ in UW type higher than the strength of control beam.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2018년도 춘계 학술논문 발표대회
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• pp.107-108
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• 2018

In this study, we applied the fiber sheet made by the stitch bonding method, which is a structure in which transverse yarns and double yarns are crossed by applying the principle of sewing knitting without the use of adhesive, The tensile strength of the reinforced concrete structure was investigated. As a result of the tensile strength test of each specimen, the specimen to which the fiber sheet produced by the stitch bonding method was applied exhibited the highest tensile strength among the three types of specimens, and the fiber sheet produced by the needle punching method exhibited the lowest strength. In addition, the stitch - bonded fiber sheet showed a difference of strength of 0.1N / mm for both length and double - sided strength difference.

• 펄프종이기술
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• 제38권4호
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• pp.68-75
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• 2006

Electromagnetic shielding sheet using the carbon and wood fiber mixture was manufactured in an effort to develop an electromagnetic shielding packaging material. Carbon fibers were cut into 5, 10, and 15 mm using the automatic cutting device and blown and dispersed using compression air passed through the fine nozzle. Then carbon fibers were slurried with water (0.1% consistency), and softwood kraft pulp along with cone starch were added. The wet mats were manufactured by dewatering in modified hand-sheet machine. The wet mats were pressed upto $4kgf/cm^2$ in the carbon and wood fiber mixture mat press. The wet mats were dried in the automatic controlled plate dryer. Investigation on the formation and surface structure of the newly developed carbon and wood fiber mixture electromagnetic shielding sheet were carried out using the scanning electron microscopy and the image analyzer. Finally electromagnetic shielding characteristics of the newly developed carbon and wood mixture sheet were measured using net-work analyser. The result was promising in the light of the fact that this method could open a new way to substitute the expensive imported electromagnetic shielding sheet.

• Composites Research
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• 제23권5호
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• pp.30-38
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• 2010

성형조건에 따른 GMT-Sheet를 관찰하여, 성형품 표면의 불량원인을 조사했다. 현미경 관찰 결과, GMT-Sheet 성형품의 표면에서 구정, 섬유돌출, 크랙, 섬유노출, 마이크로 웰드라인, 핀홀, 여파굴곡곡선 등의 결함을 발견했다. 이 결함들은 요철의 발생원인이고, 표면 광택에 영향을 주는 현상이다. 그리고 표면거칠기에 영향을 주는 요철의 가장 주요한 발생원인은 보압 냉각 과정에서 발생하는 모재의 수축이었다. 성형 시의 보압하중이 높을수록 GMT-Sheet 성형품 표면은 좋아졌다. 또한 서냉실험에서는 탈형온도가 낮을수록 성형품의 표면이 좋아졌다.

• 대한기계학회논문집
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• 제14권2호
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• pp.393-398
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• 1990

A method is proposed which can be used to obtain the fibesr content distribution of compression molded long fiber-reinforced thermoplastic sheet for nonisothermal state. The fiber is modelled to be a sphere. Once the one-dimensional unsteady state heat conduction equation in solved, the mean temperature in defined across the thickness direction. The viscosity of matrix is determined with the mean temperature. Using the obtained viscosity, two-dimensional sheet0like part compression molding is simulated with the finite element method. Comparison with experiments shows that the method accurately predicts the distribution.

• Composites Research
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• 제24권6호
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• pp.31-36
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• 2011

성형조건에 따른 GMT-Sheet를 관찰하여, 성형품 표면의 섬유돌출을 조사했다. 섬유돌출은 모재의 수축에 의해서 성형품 표면에 생성되는 불량현상의 하나이다. 즉, 섬유돌출은 성형온도에서 상온까지 성형품이 냉각될 때 모재와 유리섬유의 수축차에 의해 발생하는 표면불량 현상이다. 성형품 표면의 섬유돌출 높이는 보압 냉각과정에서 성형압력이 클수록 작게 나타남을 알 수 있다. 성형품 표면의 섬유돌출 높이는 성형압력의 영향이 지배적임을 알 수 있다. 성형압력을 고려하여, 성형품의 표면요철 생성과정과 섬유돌출 높이 변화를 규명했다. 그리고 피복층은 표면불량 현상을 억제하는 효과가 있고, 표면으로부터 섬유돌출이나 크랙이 보이지 않았다. 피복층은 표면거칠기를 단일재료인 폴리프로필렌 정도까지 개선하였다.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1999년도 학회창립 10주년 기념 1999년도 가을 학술발표회 논문집
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• pp.705-708
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• 1999

Advanced composite materials such as carbon fiber, aramid, and glass fiber sheet, are widely used recently to strengthening existing reinforced concrete structures. The purpose of this paper was to investigate the mechanical characteristics of concrete compressive members confined with carbon fiber sheet and evaluate the efficiency of the strengthening under load actions. Uniaxal compression tests of concrete compressive members confined with carbon fiber sheet were experimentally used to develop a relationship between the axial stresses and the lateral stresses. The resulting axial and lateral strains were used to determine the confinement effect of concrete compressive members.

• 한국염색가공학회지
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• 제34권3호
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• pp.185-196
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• 2022

In this study, carbon fiber and coated glass fiber are applied to warp and weft fiber in order to reduce the amount of carbon fiber used in carbon fiber fabrics, which are often used for reinforcement of building structures. A low-cost thermoplastic resin was coated on glass fibers to prepare a shape-stabilizing glass fiber. A unidirectional carbon fiber sheet was manufactured using the prepared coated glass fiber and carbon fiber. In order to identify whether it can be used for reinforcing architectural and civil structures, it was attached to a concrete specimen and its mechanical properties were analyzed. The optimum manufacturing conditions for the coated glass fiber were 0.3 mm in diameter of the coating nozzle, the coating temperature was 190 ℃, and the coating speed was 0.3 m/s. 14 mm was optimal for the weft spacing of the coated glass fiber. The flexural strength of the concrete reinforced with the manufactured unidirectional carbon fiber sheet was slightly lower than that of the concrete reinforced with carbon fiber fabric, but it was confirmed that the reinforcement effect was better when the amount of carbon fiber was considered.