• Title/Summary/Keyword: Fiber mixing ratio

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A Stydy on Steel Wire Fiber Reinforced Refractory Castable (철근 캐스터블 내화물의 고온특성에 관한 연구)

  • 박금철;최영섭;한문희;장영재;박근원
    • Journal of the Korean Ceramic Society
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    • v.17 no.2
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    • pp.69-74
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    • 1980
  • This study deals with the wire content, wire diameter, aspect ratio , it's arrangement of steel, wire fiber and the sorts of castable which affected the character of steel wire fiber reinformced refractory castable. Two kinds of alumina based refractory castables, one is for 1650℃ and the other is for 1800℃, and stainless steel which is SUS 304 type 0.25, 0.34 , 0.37 and 0.50m/min diameter were used respectively. Aspect ratio was adjusted to 50, 75, 100 and steel fiber content was also adjusted to 1-4wt% each. The results of the experiment were as follows : 1. At firing temperature around 1,000℃, MOR is increased with increasing wire content and aspect ratio with decreasing firing temperature, which depends on the Romualdi's Fiber Spacing Theory. But for calculation of the fiber spacing, Swamy equation is more a aplicable to the extensive fiber mixing conditions. However, the condition differs from the above at firing temperature around 1,350℃ ,because of the degradation of wire and the progress of sintering of castable. 2. Linear change is getting larger corresponding to the increase of wire content, and the spaling resistivity is increasing corresponding to the increase of wire content and to aspect ratio, and with decreasing wire diameter. 3. Firing shrinkage under load is getting greater as higher wire content, and the shrinkage of the test pieces which fiber is vertically oriented is getting greater than the test pieces which fiber is randomly oriented.

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Strength Properties of Cement Composite according to the Mixing Ratio of Amorphous Metallic Fiber (비정질금속섬유 혼입율에 따른 시멘트 경화체의 강도 특성)

  • Kim, Ji-Hwan;Rho, Young-Hwan;Lee, Jae-In;Bae, Sung-Ho;Oh, Tae-Gue;Choi, Se-Jin
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2020.11a
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    • pp.79-80
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    • 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.

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Impact of Four Wave Mixing on Manchester Coded ASK Multichannel Optical Communication System (Manchester Coded ASK 다중채널 광통신 시스템의 Four Wave Mixing 에 대한 영향)

  • Lee, Ho-Joon;Leonid G. Kazovsky
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.18 no.11
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    • pp.1607-1617
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    • 1993
  • The performance of Manchester-coded ASK optical wavelength division multiplexing(WDM) systems is evaluated laking into account the shot noise and the four wave mixing(FWM) caused by fiber nonlinearities. The result is compared to conventional non-return-to-zero(NRZ) systems for ASK modulation formats. Further, the dynamic range, defined as the ratio of the maximum input power(limited by the FWM), to the minimum input power(limited by receiver sensitivity), is evaluated. For 1.55 rm 16 channel WDM systems, the dynamic range of ASK Manchester coded systems shows a 2.0 dB improvement with respect to the NRZ. This result holds true for both dispersion-shifted fiber and conventional fiber it has been obtained for 10 GHz channel spacing, 1 Gbps/channel bit rate.

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Properties of Advanced Synthetic Fiber Reinforced Concrete for Improvement of Tunnel Shotcrete Performance (터널 숏크리트 성능 향상을 위한 고기능성 합성섬유 보강 콘크리트의 물성 평가)

  • Jeon, Chanki;Jeon, Joongkyu
    • Journal of the Society of Disaster Information
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    • v.7 no.1
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    • pp.43-50
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    • 2011
  • The Application of Steel Fiber Shotcrete in tunneling construction has become part of tunneling practice at least since the 1970s because of its high bending and tensile properties. Over the past 3 decades, researcher from all over the world have been significantly developing the associated technologies for improved performance of SFRS. But still it has some major drawbacks in terms of durability, damage of pumping hose, wastage due to rebound concrete, corrosion and it costs high. To overcome this situation researcher has to look for some alternative material. Therefore, this part study deals with the three types of fiber in order to find good alternative for steel fiber. Polyamide and Polypropylene fiber were used in this study with 0.6, 0.5% mixing ratio. To evaluate its fresh and harden properties air content, slump, compressive, split tensile and bending strength were measured. After comparing the results of all three types of fiber reinforced concrete with its different mixing proportion this study propose that polyamide fiber with addition ratio of 0.6 % for field use.

Compressive Creep Properties of Reinforced Soil Mixture (보강혼합토의 압축 크리프 특성)

  • 이상호;차현주;김철영
    • Magazine of the Korean Society of Agricultural Engineers
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    • v.44 no.6
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    • pp.115-123
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    • 2002
  • This study was performed to provide basic data for development and construction of reinforced soil wall that mixed with reinforcements such as calcium carbonate, monofilament fiber. In order to determine proper moisture content and mixing ratio by weight of reinforcement, Poisson's ratio and compressive strength tests for sandy soil had been conducted. Model tests for long-term behavior of reinforced soil wall were carried out to investigate the effect of reinforcement during loads and under static loads. The results of creep and model tests for sandy soil compared with clayey soil. Reinforced sandy soil mixed with calcium carbonate and cement showed brittle rupture by shear but that of mixed with monofilament fiber showed ductile rupture due to the tension force of fiber. It was shown that when age increased, creep strain of reinforced soil under sustained load approached constant values.

Changes of Handsheet Fracture Toughness by Wood and Cotton Fibers Mixing (목재섬유와 면섬유의 혼합에 따른 수초지의 파괴인성 변화)

  • Kim, Jeong-Jung;Jang, Dong-Uk;Yoon, Sang-Gu;Shin, Hyeon-Sik;Park, Jong-Moon
    • Journal of Korea Technical Association of The Pulp and Paper Industry
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    • v.46 no.3
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    • pp.81-87
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    • 2014
  • Conditions of paper manufacturing process should be changed depending on the end use and paper properties. Most of the case, mixed pulps with long softwood fibers and short hardwood fibers are used to achieve proper qualities of product with reasonable production cost. For specialty paper manufacture the wood pulp and cotton linter pulp are usually mixed together. The objectives of this study is to analyze physical, mechanical and fracture mechanical properties of paper depending on SwBKP, HwBKP and cotton linter pulp(CLP) mixing. When the mixing ratio of SwBKP was increased, strength properties, such as tensile, tear, and folding endurance, were also increased. When the mixing ratio of SwBKP and HwBKP was increased, stress concentration index was decreased and fracture toughness was increased.

Evaluation on Water Vapor Pressure of Amorphous Steel Fiber reinforced High Strength Concrete (비정질 강섬유 혼입 고강도콘크리트의 수증기압력 평가)

  • Kim, Duck-Woo;Kim, Gyu-Yong;Hwang, Eui-Chul;Son, Min-Jae;Baek, Jae-Wook;Nam, Jeong-Soo
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2018.11a
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    • pp.44-45
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    • 2018
  • In this study, water vapor pressure of high strength concrete reinforced with amorphous steel fiber(AF) was evaluated. Experimental results show that spalling occurs when the incorporation rate of amorphous steel fiber is 0.5 vol.% or more. This is because the ratio of AF increased per unit area influenced the formation of the water vapor pressure discharge passage by the polypropylene fiber(PPF) melting. Therefore, it is necessary to find the proper mixing ratio of AF and PPF to prevent spalling.

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A Quality Comparison of Traditional Korean Papers: Mixtures of Bast-Fiber with Straw pulp(Rice straw paper) in Different Composition Ratio (고정(藁精) 혼합비율에 따른 한지의 물성 비교)

  • Jung, Sun-Young
    • Journal of Korea Technical Association of The Pulp and Paper Industry
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    • v.39 no.1 s.119
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    • pp.48-55
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    • 2007
  • The aim of this article is to review the general property of the famous traditional Korean paper, "rice straw paper"(Bast-Fiber mixed with straw pulp), and to compare the paper qualities varying with the composition ratio of straw pulp, in order to revive the traditional paper in modem Korea. The experiment was carried out by making first the two different mixture papers, i. e., one is the paper of 50% bast fiber mixed with 50% straw pulp, and the other is the paper of 75% bast fiber with 25% oats straw pulp, and finally the 100% bast fiber paper was made for the purpose of comparison. The qualitative properties of these three kinds of paper with the different mixing ratio of the straw pulp were evaluated, and the findings of the experiment can be summarized as follow: 1. As to the quality aspects of the paper strength like tensile strength, breaking length, elongation, and tear strength, the test proved the 100% bast fiber paper as best, and the 50% mixed paper as the next good one. 2. In aspect of the printing adaptability such as density, opacity, brightness, whiteness, lab colors, air permeability, and roughness, the 50% mixed paper proved to be the best, due to the short cells in the straw pulp. 3. As to the air permeability, the larger ratio of straw pulp was found to be the lesser, and 75% bast fiber with 25% straw pulp mixture paper and the 100% bast fiber one were found 1/5 degree efficient. 4. In terms of the water absorption degree, 100% bast fiber paper was the fastest, but in case of mixture paper, 50% mixed one was a little faster up to the point of 1cm, while the two kinds of mixed ones appear to be almost similar to each other beyond the point. 5. The straw pulp mixed paper, especially the 50% mixed one was evaluated as the highest by the calligraphers who had experienced using the papers in terms of movement and feeling of the caligraphy and painting. In addition, although the 25% mixed paper is judged to be good for book printing because of the strength, the 50% mixed paper can be thought to be more desirable for painting and calligraphy. In conclusion, we will be able to make the quality paper with durability, by mixing the straw pulp with the bast fiber in proper ratio, following the tradition of Korean paper making.

Preparation of High-Fiber Bread with Camellia (Camellia Japonica L.) Seed Flour (동백유박을 이용한 고식이섬유빵 제조)

  • 강성구;최옥자;김용두;이홍철;고무석
    • Korean Journal of Plant Resources
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    • v.11 no.3
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    • pp.358-362
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    • 1998
  • This study was carried out to examine the effect on the contents of dietary fiber, mechanical properties, and sensory quality of bread contained with 10% of high-fiber Camellia (Camellia japonica L.) seed flour. Bread added by dietary fiber was the contents of moisture, protein and ash higher than control bread, while the contents of lipid lower than that of control bread. The high-fiber with Camellia seed flour contained 8.6% soluble dietary fiber, 43.7% insoluble dietary fiber, and 52.3% total dietary fiber. The ratio of insoluble dietary fiber/soluble dietary fiber in the high-fiber with Camelia seed flour was 5 times. Bread with the addition of dietary fiber contained 6.9% total dietary fiber. With the addition of dietary fiber, water absorption , mixing time loaf weight, and hardness increased, but the loaf volume decreased . The sensory quality on bread added by dietary fiber was somewhat low in color, appearance, crumb texture, mouthfeel, flavor and overall preference was higher than that of control bread.

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Spalling Properties of 60, 80MPa High Strength Concrete with Fiber (복합섬유(PP, NY)를 혼입한 60, 80MPa 3성분계 고강도콘크리트의 내화특성)

  • Kim, Seong-Deok;Kim, Sang-Yun;Bae, Ki-Sun;Park, Su-Hee;Lee, Bum-Sik
    • Journal of the Korea Institute of Building Construction
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    • v.10 no.4
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    • pp.3-9
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    • 2010
  • Fire resistance and material properties of high-strength concrete (W/B 21.5%, 28.5%) with OPC, BS and FA were tested in this study. Main factors of the test consisted of fiber mixing ratio and W/B. Two types of fiber (NY, PP) mixed with the same weight were used for the test. The fiber mixing ratios were 0%, 0.05%, 0.1%, and 0.2% of the concrete weight. After performing the test, Under the W/B level of 21.5% and 28.5%, the spalling was effectively resisted by using the high strength concrete with fiber mixing ratios of 0.05%~0.1%. Compressive strength, flowability and air content are similar those of the fiberless high-strength concrete with the same W/B.