• Tunnel and Underground Space
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• v.14 no.4
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• pp.241-247
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• 2004

In this study, new polypropylene fiber was developed for shotcrete and concrete reinforcement, by treating the surface of the polypropylene by maleic anhydride grafted polypropylene(mPP). Dispersiveness of the fiber was tested. Mechanical properties of fiber reinforced shotcrete was tested.

• Journal of the Korea institute for structural maintenance and inspection
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• v.15 no.4
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• pp.125-135
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• 2011

The bond properties between polypropylene fiber reinforced cement composites and structural synthetic fiber have been investigated. in this paper. Three levels of polypropylene fibers volume fraction were used, 0.10%, 0.15%, and 0.20% in a series of Dog-bone pull out tests. The bond strength between structural synthetic fiber and polypropylene fiber reinforced cement composites increases with the volume fraction of polypropylene fiber, but the bond strength decreases above the amount of 0.20% by volume of polypropylene fiber reinforced cement composites. Also, the addition of polypropylene fiber a significant improved the interface toughness and the frictional resistance, The microstructure of structural synthetic fiber surface was investigated after the pullout test. The scratched of structural synthetic fiber increased with the polypropylene fiber volume fraction.

• Proceedings of the Korea Concrete Institute Conference
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• 1995.04a
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• pp.305-310
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• 1995

토목 및 건축재료로서 폴리프로필렌 섬유 모르타르 및 콘크리트의 사용은 미국, 영 국 등지에서 개발되기 시작하여 많은 연구가 진행되어 왔는데, 가격이 저렴하고, 화학적인 안정성과 내구성이 우수하여 그 사용이 점차 증대되고 있는 실정이다. 이러한 폴리프로필렌 섬유의 사용은 모르타르 및 콘크리트가 건조나 냉각에 의해 수축될 때 구속에 의해 발생하 는 인장응력 및 균연을 제어하고, 인성의 증가와 충격, 마모, 피로에 대한 저항성, 내구성을 증대시키는 등의 장점을 가지는 것으로 보고되고 있다. 본 연구에서는 이러한 폴리프로필렌 섬유 모르타르 및 콘크리트의 역학적 거동특성인 압축강도, 인장강도, 인성, 유동성과 균열 특성을 실험적으로 규명하고자 하였다. 실험결과 폴리프로필렌의 혼입량이 증가할수록 압축 강도, 인장강도, 인성의 증가를 보였으나, 혼입향 0.2%를 초과할 경우 유동성, 강도 모두 감 소하는 것을 볼 수 있었다. 그리고 단섬유형 보다는 메쉬 형태의 폴리프로필렌 섬유가 역학 적 특성면에서 우수한 것으로 관찰되었으며, Kraai 방법에 의한 소성수축균열제어 특성 실 험에서 약 45% 이상으 균열감소 (0.1%혼입) 효과를 볼 수 있었다.

• Composites Research
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• v.19 no.3
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• pp.15-22
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• 2006

In this study, we prepared glass fiber reinforced polypropylene composites using Brabender twin-screw extruder. Compatibilizer, polypropylene-based maleic anhydride (PP-g-MAH), was used to increase the molecular interaction between polypropylene matrix and glass fiber and to enhance melt processability. We also measured the shear and uniaxial elongational behaviors of glass-fiber reinforced composites in the absence or presence of compatibilizer. The effects of compatibilizer and fiber loading on the viscoelastic behaviors were examined. It was fuund that the PP-g-MAH compatibilizer improved the fluidity and increased the molecular bonding of composite melts in shear flow. Transient elongational viscosity was increased with fiber loadings in uniaxial elongational flow However, it was decreased with increasing elongational rates because of microscale shear flow between fibers.

• Proceedings of the Korea Concrete Institute Conference
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• 2008.11a
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• pp.457-460
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• 2008

This study evaluated fire resistance performance for polypropylene/steel fiber reinforced high strength concrete column. Full-size columns were constructed and tested with or without fibers using ISO-834 fire curve. As the result of test, non-fiber high strength concrete column specimen occurred serious spalling and indicated rapidly internal temperature increase. Specimen with polypropylene fiber occurred not spalling. Specimen with hybrid fiber occurred not spalling as well as does not propagated temperature propagation. Therefore, hybrid fiber reinforced column specimen indicated a good fire resistance performance than other cases.

• Journal of the Korea Concrete Institute
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• v.20 no.6
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• pp.821-826
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• 2008

This study evaluated spalling and internal temperature distribution after elevated temperatures test for high strength concrete ($f_{ck}=60\;MPa$) column member with various polypropylene fiber volume fractions. The ISO-834 time-temperature curve was used for measurement of fire resistance properties. As the result of test, average internal temperature results indicated to low temperature in increased polypropylene fiber volume fraction. But, the highest internal temperature results show that does not difference in proportion of polypropylene fiber volume fractions.

• The Korean Journal of Rheology
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• v.1 no.1
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• pp.63-70
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• 1989

고밀도 폴리에틸렌과 폴리프로필렌을 용융혼합하여 블렌드를 만들었다. 압출물의 morphology 와 유변학적 성질을 측정하고 그 용융하고 섬유의 X-선 회절, 인장 성질, 복굴 절률등과 관련하여 고찰하였다. 파단면의 SEM 사진으로부터 폴리에티렌 성분비가 25%, 50% 에서는 폴리프로필렌이, 75%에서는 폴리에틸렌이 연속상을 이루며 분산상은 고르게 분포함을 알았다 점도와 용융탄성은 모두 폴리에틸렌이 폴리프로필렌보다 크며 블렌드에서 는 그중간에 위치 하였다. 폴리에틸렌의 함량의 증가에 따라 압풀물의 제 1법선 응력차는 증가하였고따라서 방사 섬유의 복굴절률도 증가하였으며 초기 탄성률도 증가하는 경향을 보 였으나 결정 배향도는 조성 의존성을 갖지 않는다. 두 고분자의 비상용성으로 인해 강도는 짓선성에서 벗어나는 거동을 나타내었다.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.34 no.6
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• pp.1677-1685
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• 2014

Short discrete fibers compounded with concrete can enhance the tensile resistance and ductility of concrete. Recently, the effectiveness of the reinforcement has increased according to the increasing length of steel fiber. However, the lengthening of steel fiber requires reducing the ratio of the fiber content to remain the workability and quality of concrete. Thus, the present study evaluated the flexural performance of fiber reinforced concrete with less than l.0% fiber volume ratios of steel fiber, 30mm and 60mm long, and polypropylene fiber, being evaluated as a good reinforcing material with chemical stability, long-term durability, and cost effectiveness. Concrete with more than 0.25% steel and 0.5% polypropylene fibers improved the brittle failure of concrete after reaching cracking strength. Concrete reinforced with polypropylene exhibited deflection-softening behavior, but that with more than 0.5% polypropylene delayed stress reduction and recovered flexural strength by 60 to 80% after cracking strength. In conclusion, concrete reinforced with more than 0.75% polypropylene could improve structural flexural performance. In particular, energy absorption capacity of reinforced concrete with 1.0% polypropylene fiber was similar to that with 0.5% and 0.7% steel fibers.

• Journal of the Korean Recycled Construction Resources Institute
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• v.7 no.4
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• pp.438-444
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• 2019

In this study, the effect of polypropylene fiber on the freeze-thaw damage of mortar was evaluated experimentally. The effects of the reinforcing of polypropylene fiber on the compressive and bending performance of mortar after 300 cycles of freeze-thaw test were evaluated by comparing the normal mortar and the mortar with polyvinyl alcohol fiber. In addition, the mass loss, relative dynamic elastic modulus, and cumulated pore volume of mortar were measured by each cycle of freeze-thaw test. As a result, it was confirmed that the fiber reinforced mortar, regardless of the fiber type, was effective not only in maintaining the performance of the compressive strength and the bending strength but also suppressing the mass loss after the freeze-thaw test of 300 cycles. Meanwhile, it was confirmed that not only polyvinyl alcohol fibers but also polypropylene fibers can effectively act to suppress the damage of the mortar by freeze-thaw. However, in order to improve the freeze-thaw resistance of mortar mixed with polypropylene fiber, it is necessary to increase the bonding performance with the cement matrix which can be expected from polyvinyl alcohol fiber.

• Proceedings of the Korean Fiber Society Conference
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• 2001.10a
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• pp.111-114
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• 2001

폴리프로필렌 섬유는 강도, 인성, 내마모성, 레질리언스 등의 물리적 성질이 우수하여 각종 산업용 소재로 폭 넓게 사용되고 있다[1]. 그러나 폴리프로필렌은 장점도 많지만 분자구조 특성으로 인하여 대전방지성, 소수성 등과 같은 표면특성들이 좋지 안은 단점도 있다[2,3]. 따라서 폴리프로필렌의 표면특성을 개질 하기 위하여 금속화합물, 고분자 첨가제를 혼합시키는 방법[4,5], 물리적ㆍ화학적으로 섬유를 처리하는 방법, 공중합과 벨렌드에 의한 방법 등이 사용되어 왔으며, 최근에는 유기물 고분자에 비하여 내열성, 내절연성, 그리고 표면특성이 우수한 실리콘을 공중합하여 변성수지를 개발하거나 블렌드하는 방법등이 이용되고 있다. (중략)