• Proceedings of the Korean Fiber Society Conference
• /
• 2001.10a
• /
• pp.440-443
• /
• 2001

Polymer/layered silicate nanocomposites have recently received considerable attention from both academia and industry as an effective way to overcome the shortcomings of conventional polymer. When the silicate layers are exfoliated and randomly distributed in polymer matrix, the nanocomposites exhibit improved mechanical, thermal and barrier properties. (omitted)

• Proceedings of the Korean Fiber Society Conference
• /
• 2001.10a
• /
• pp.29-32
• /
• 2001

Conductive polymers(CPs) are a relatively new class of organic materials displaying as their foremost property a high conductivity combined with very light weight, flexibility and reasonably facile processability[1]. Due to their high conductivity/weight ratio, they have recently evinced much interest in potential application as EMI shielding screens, coatings or jackets for flexible conductors, rechargeable batteries and as possible substitutes for metallic conductors or semiconductors in wide variety of electrical devices[2]. (omitted)

• Proceedings of the Korea Concrete Institute Conference
• /
• 1990.10a
• /
• pp.145-150
• /
• 1990

In order to discuss the freeze-thaw durability of FRC and mechanical properties by the fiber types of FRC, experimental studies of FRC were carried out. The kinds of fiber used which are in CFRC are PAN-based and Pitch-based carbon fiber and in GFRC are alkali-resistance glass fiber. To examine the effects of the kinds, types (continuous fiber and Tow, Belt, Cloth) and contents of fiber and matrices, the following three methods CFRC and GFRC, Air cured, Water cured and Autoclaved CFRC and GFRC were tested. According to the test results, the flexural, tensile strength and toughness of FRC were remarkably influenced by types of fiber and addition of condensed silica fume. Also, freeze-thaw resistance of FRC was considerably improved in comparision to conventional mortar.

• Proceedings of the Korean Institute of Surface Engineering Conference
• /
• 2009.10a
• /
• pp.181-181
• /
• 2009

탄소섬유의 우수한 기계적, 화학적, 전기적 특성을 이용한 산업전반에 대한 연구가 활발히 수행되어 지고 있다. 본 연구에서는 탄소섬유를 supercapacitor의 전극과 복합체에 활용하기 위해서 탄소섬유상에 탄소나노튜브를 증착시키는 실험을 수행하였다. 균일하고 높은 증착 밀도의 탄소나노튜브를 증착시키기 위해서 본 연구에서는 기존의 CF 표면처리 방법- anodizing, plasma treatment, heat treatment등과 달리 간단한 wet-process방법을 이용해 CF 표면처리 및 catalyst증착공정을 동시에 수행하여 고밀도의 CNT를 증착하였다.

• Proceedings of the Korean Institute of Building Construction Conference
• /
• 2020.11a
• /
• pp.79-80
• /
• 2020

This study compared and analyzed the flow and strength characteristics of cement paste according to the rate of mixing of amorphous metallic fiber as part of the research for the development of amorphous metallic fiber reinforced cement composite.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.34 no.2
• /
• pp.447-455
• /
• 2014

This study was intended to estimate the efficiency of inducing fiber arrangement in UHPCC (Ultra High Performance Cementitious Composites). For the purpose, UHPCC members produced by several different placing methods according to flow characteristics were prepared; flexural behaviors were compared and correlation between the flexural behavior and the characteristics of fiber arrangement was investigated. Test results showed that placing method for inducing specific fiber arrangement had a considerable influence on the flexural performance. The standard specimen in which fibers are induced to be directed parallel to the principle tensile direction presented higher flexural tensile strength but lower variation. Therefore it should be considered that the flexural tensile strength actually developed in UHPCC member may be highly different and in lager variation. The qualitative variation of fiber arrangement according to the flow of UHPCC was also predicted considering the flow pattern and the boundary effect; the prediction provided good explanation to the difference in the flexural behavior according to the induced flow.

• Journal of the Korea institute for structural maintenance and inspection
• /
• v.16 no.3
• /
• pp.117-127
• /
• 2012

As increasing number of large-size earthquake around Korean peninsula, many interests have been focused to the earthquake strengthening of existing structures. Fiber reinforced plastic composite material is one of strengthening material widely used to increase seismic performance of structures. It should have high stiffness as well as large ductility to provide best strengthening result. Thus selection of stiffener and fiber in composite is of important. In this study, the optimal combination of fiber and stiffener is selected with variety of tensile tests. In order to investigate performance of chosen composite material, several finite element analyses are performed with proposed FRP composite material for existing RC columns. It is discussed that the seismic performance of strengthened columns through the load-displacement relationship. It is shown that the proposed composite material can increase the strength as well as ductility of exiting RC columns.

• Journal of the Korea institute for structural maintenance and inspection
• /
• v.12 no.5
• /
• pp.81-90
• /
• 2008

This paper concerns the flexural capacity of reinforced concrete beams with ultra-high performance cementitious composites(UHPCC). It was investigated if the existing equations to estimate the flexural capacity of reinforced fiberous concrete beams are applicable with the experiments including lightly reinforced concrete beams. The reinforcing effect when the steel fiber reinforced concrete was used in beams was also estimated. The results showed that the equation to predict the flexural capacity of reinforced steel fiber concrete by ACI 544 committee didn't have a good agreement with the test results and underestimated the flexural capacity in especially lightly reinforced beams with under 1.5% reinforcement ratio. the enhancement of flexural capacity was quite considerable in lightly reinforced beams when the steel fiber reinforced concrete was used. A equation to predict the reinforcing effect of steel fiber in reinforced steel fiber beams was developed. the equation was proposed as a function of both the characteristics of steel fiber and reinforcement ratio.

• Journal of the Korea Institute of Building Construction
• /
• v.14 no.6
• /
• pp.639-645
• /
• 2014

For the construction materials, concrete, as the most widely used material, is focused on its improvement of performance. Although concrete has many advantages of easiness of handling, economical benefits, and high compressive strength, low tensile strength, brittleness and drying shrinkage are reported as the drawbacks of concrete. Hence, to solve these drawbacks of concrete, many research has conducted especially using fiber-reinforced concrete technology. Especially, HPFRCC which has high volume of fiber reinforcement was suggested as a solution of these drawbacks of normal concrete with increased ductility while it has the possibility of workability loss with fiber clumping which can cause low performance of concrete. Therefore, in this paper, optimized fiber combination with either or both metal and organic fibers is suggested to provide better performance of HPFRCC in tensile strength and ductility. As the results of experiment, better workability was achieved with 1 % of single fiber rather than multiple fibers combinations, espeically, short steel fiber showed the best workability result. Furthermore, in the case of organic fibers which showed higher air content than steel fibers, higher compressive strength was achieved while lower tensile and flexural strength were shown.

• Textile Coloration and Finishing
• /
• v.31 no.1
• /
• pp.42-47
• /
• 2019

In this study, the effects of surface treatment of bamboo fiber on the physical properties of polypropylene(PP)/glass fiber(GF)/Bamboo fiber(BF) composite for engine cover were investigated. PP, GF and BF were fixed at 40%, 40% and 20% and the surface of bamboo fibers were treated to 0.5, 1.0 and 2.0% as an acid and alkali solution. PP/GF/BR composites using surface treated bamboo fibers were prepared and their tensile strength, bursting strength and impact strength were measured by universal testing machine(UTM). The composites with alkali treated bamboo fiber showed better mechanical properties than the acid treated composites. It was checked that the optimum alkali content was at 1.0% from the results of mechanical properties. The effect of surface treatment on the mechanical properties was confirmed by SEM images of fractured surface.