• 제목/요약/키워드: Fiber-reinforced polymer

검색결과 944건 처리시간 0.033초

Axial impact behavior of confined concrete filled square steel tubes using fiber reinforced polymer

  • Zhang, Yitian;Shan, Bo;Kang, Thomas H.K.;Xiao, Yan
    • Steel and Composite Structures
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    • 제38권2호
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    • pp.165-176
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    • 2021
  • Existing research on confined concrete filled steel tubular (CCFT) columns has been mainly focused on static or cyclic loading. In this paper, square section CCFT and CFT columns were tested under both static and impact loading, using a 10,000 kN capacity compression test machine and a drop weight testing equipment. Research parameters included bonded and unbonded fiber reinforced polymer (FRP) wraps, with carbon, basalt and glass FRPs (or CFRP, BFRP, and GFRP), respectively. Time history curves for impact force and steel strain observed are discussed in detail. Experimental results show that the failure modes of specimens under impact testing were characterized by local buckling of the steel tube and cracking at the corners, for both CCFT and CFT columns, similar to those under static loading. For both static and impact loading, the FRP wraps could improve the behavior and increase the loading capacity. To analyze the dynamic behavior of the composite columns, a finite element, FE, model was established in LS-DYNA. A simplified method that is compared favorably with test results is also proposed to predict the impact load capacity of square CCFT columns.

천연섬유강화 폴리머 복합재료의 압축강도 특성 (Compressive Strength of Natural Fiber Reinforced Polymer Composites)

  • 송준희;문상돈;김유경;김홍건
    • 한국생산제조학회지
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    • 제19권1호
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    • pp.140-144
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    • 2010
  • In recent years there has been a growing interest for the use of natural fibers in composite applications due to their low cost, environmental friendliness, and good mechanical properties. The purpose of this study is to determine the characteristic of bending strength on bamboo fiber reinforced polymer composites. The parameters of RTM process depend on the weight ratio of bamboo fiber and resin, the number of bamboo ply and amount of hardening agent. Besides the existence of pore in composites according to vacuum time investigated a effect on mechanical properties of reinforced polymer composites. Test result shows that compressive strength was a maximum(approximately 1,840kgf/$cm^2$) value when weight ratio of resin was 12%.

A study on load-deflection behavior of two-span continuous concrete beams reinforced with GFRP and steel bars

  • Unsal, Ismail;Tokgoz, Serkan;Cagatay, Ismail H.;Dundar, Cengiz
    • Structural Engineering and Mechanics
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    • 제63권5호
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    • pp.629-637
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    • 2017
  • Continuous concrete beams are commonly used as structural members in the reinforced concrete constructions. The use of fiber reinforced polymer (FRP) bars provide attractive solutions for these structures particularly for gaining corrosion resistance. This paper presents experimental results of eight two-span continuous concrete beams; two of them reinforced with pure glass fiber reinforced polymer (GFRP) bars and six of them reinforced with combinations of GFRP and steel bars. The continuous beams were tested under monotonically applied loading condition. The experimental load-deflection behavior and failure mode of the continuous beams were examined. In addition, the continuous beams were analyzed with a numerical method to predict the load-deflection curves and to compare them with the experimental results. Results show that there is a good agreement between the experimental and the theoretical load-deflection curves of continuous beams reinforced with pure GFRP bars and combinations of GFRP and steel bars.

폴리머콘크리트 박스 거어더의 구조적 거동 (Structural Behavior of Polymer Concrete Bos Girders)

  • 연규석;김광우;이윤수;김성순
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 1993년도 가을 학술발표회 논문집
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    • pp.213-219
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    • 1993
  • The box girder was developed using polymer concrete, box girder were made for flexural behavior evaluation. The box girder was reinforced with reinforcing steel bars and fiber glass roving cloths. Failure loads were 13.5 tons and 16.6tons for steel reinforced girder and fiber glass reinforced girder, respectively. Especially for the fiber glass reinforced girder, the shape was not changed even after failure. It is expected that application of this idea will be useful for developing under ground box, girder, utility tunnel, small stream bridge box, etc.

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직조된 대나무 자연섬유 복합재료의 제조인자에 따른 굽힘강도 (Bending Strength of Natural Woven Bamboo Fiber-reinforced Polymer Composites with Manufacturing Factors)

  • 송준희;임재규
    • 대한기계학회논문집A
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    • 제30권8호
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    • pp.916-922
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    • 2006
  • In recent years there has been a growing interest for the use of natural fibers in composite applications due to their low cost, environmental friendliness, and good mechanical properties. The purpose of this study is to determine the characteristic of bending strength on bamboo fiber reinforced polymer composites. The parameters of RTM process depend on the weight ratio of bamboo fiber and resin, the number of bamboo ply and amount of hardening agent. Mechanical properties was investigated for each process factor of polymer composites. Test result shows that bending strength was a maximum(approximately 85MPa) value when composite thickness was 6mm and weight ratio of resin was 13%.

섬유보강 폴리머 콘크리트의 강도특성에 관한 기초적 실험적 연구 (An Fundamental Experimental Study on the Strength Characteristics of Fiber-Reinforced Polymer Concrete)

  • 오병환;김영선
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 1989년도 가을 학술발표회 논문집
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    • pp.5-8
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    • 1989
  • Considerable efforts are still being made in the every part of the world to develop new construction materials. The polymer concrete is one of those promising new construction materials. The strength characteristics of fiber-reinforced polymer methods and filler contents on the properties of polymer concrete were explored. The effects of fiber addition are also discussed.

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섬유보강 폴리머 포러스콘크리트의 특성에 관한 실험적 연구 (Studies on the Properties of Fiber Reinforced Porous Concrete Using Polymer)

  • 박승범;이병재;이준;손성우;조광연
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 2006년도 춘계 학술발표회 논문집(II)
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    • pp.581-584
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    • 2006
  • This study is analyzed mechanical properties and durability of permeability porous concrete to mix polymer and steel fiber for the enhance of performance and durability of porous concrete. It proves that void ratio and permeability are tallied with internal and external standard of paving porous concrete. A property of strength is increased according as the mixing rate of polymer and steel fiber increase, but it showed the tendency to be reduced on the contrary when mixed upwards of 20% of polymer mixing rate and 0.9vol.% of steel fiber mixing rate. As a result, it is possible to make an enhanced which increased 16% of compressive strength and 30% of flexural strength steel fiber reinforced polymer porous concrete at the mixing rate of 10vol.% of polymer and 0.6% of steel fiber.

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Computational optimized finite element modelling of mechanical interaction of concrete with fiber reinforced polymer

  • Arani, Khosro Shahpoori;Zandi, Yousef;Pham, Binh Thai;Mu'azu, M.A.;Katebi, Javad;Mohammadhassani, Mohammad;Khalafi, Seyedamirhesam;Mohamad, Edy Tonnizam;Wakil, Karzan;Khorami, Majid
    • Computers and Concrete
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    • 제23권1호
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    • pp.61-68
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    • 2019
  • This paper presents a computational rational model to predict the ultimate and optimized load capacity of reinforced concrete (RC) beams strengthened by a combination of longitudinal and transverse fiber reinforced polymer (FRP) composite plates/sheets (flexure and shear strengthening system). Several experimental and analytical studies on the confinement effect and failure mechanisms of fiber reinforced polymer (FRP) wrapped columns have been conducted over recent years. Although typical axial members are large-scale square/rectangular reinforced concrete (RC) columns in practice, the majority of such studies have concentrated on the behavior of small-scale circular concrete specimens. A high performance concrete, known as polymer concrete, made up of natural aggregates and an orthophthalic polyester binder, reinforced with non-metallic bars (glass reinforced polymer) has been studied. The material is described at micro and macro level, presenting the key physical and mechanical properties using different experimental techniques. Furthermore, a full description of non-metallic bars is presented to evaluate its structural expectancies, embedded in the polymer concrete matrix. In this paper, the mechanism of mechanical interaction of smooth and lugged FRP rods with concrete is presented. A general modeling and application of various elements are demonstrated. The contact parameters are defined and the procedures of calculation and evaluation of contact parameters are introduced. The method of calibration of the calculated parameters is presented. Finally, the numerical results are obtained for different bond parameters which show a good agreement with experimental results reported in literature.

Corrosion of rebar in carbon fiber reinforced polymer bonded reinforced concrete

  • Bahekar, Prasad V.;Gadve, Sangeeta S.
    • Advances in concrete construction
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    • 제8권4호
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    • pp.247-255
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    • 2019
  • Several reinforced concrete structures that get deteriorated by rebar corrosion are retrofitted using Carbon Fiber Reinforced Polymer (CFRP). When rebar comes in direct contact with CFRP, rebar may corrode, as iron is more active than carbon. Progression of corrosion of rebar in strengthened RC structures has been carried out when rebar comes in direct contact with CFRP. The experimentation is carried out in two phases. In phase I, corrosion of bare steel bar is monitored by making its contact with CFRP. In phase II, concrete specimens with surface bonded CFRP were casted and subjected to the realistic exposure conditions keeping direct contact between rebar and CFRP. Progression of corrosion has been monitored by various parameters: Half-cell potential, Tafel extrapolation and Linear Polarisation Resistance. On termination of exposure, to find residual bond stress between rebar and concrete, pull-out test was performed. Rebar in contact with CFRP has shown substantially higher corrosion. The level of corrosion will be more with more area of contact.

자연 섬유 복합재료의 국내외 기술 및 시장 현황 (Domestic/overseas Market and Technical Issues of Natural Fiber-reinforced Polymer Composites)

  • 이진우;이정훈;황병선;김병선
    • Composites Research
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    • 제20권2호
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    • pp.32-38
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    • 2007
  • Natural fibers can refer to all types of fibres only produced by nature. Their lengths vary from particles to long strands. Natural fibers are categorized roughly by six types, depending on the types of sources; base, leaf, seed, grasses, fruit and wood. Of these fibers, jute, flax, sisal and ramie are the most commonly used as reinforced materials in preparing polymer composites. In development and improvement of these composites, many studies have been implemented to overcome the drawbacks such as incompatibility, moisture problems and so on. The range of industry sectors of natural fiber-reinforced polymer composites becomes more extensive gradually and many of the companies all over the world are engaged in fabrications or applications. This paper mainly discussed the recent status of the domestic/overseas market and research issues of natural fiber-reinforced polymer composites. We made an exception of wood-polymer composites market which have played a great role because they had been often dealt with.