• Title/Summary/Keyword: abrasion resistance

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Mechanical Properties of Porous Concrete For Pavement Using Recycled Aggregate and Polymer (재생골재와 폴리머를 이용한 포장용 포러스 콘크리트의 역학적 특성)

  • Park Seung-Bum;Yoon Eui-Sik;Seo Dae-Seuk;Lee Jun
    • Journal of the Korea Concrete Institute
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    • v.17 no.4 s.88
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    • pp.595-602
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    • 2005
  • The purpose of this study is to utilize recycled concrete aggregates as permeable pavement materials. This study evaluates mechanical properties and durability of porous concrete depending on mixing rates of recycled aggregates and polyme. As a result, void ratio and permeability coefficient of porous concrete for pavement increased a little as mixing rate of recycled aggregates increased. Void ratio and permeability coefficient increased a lot as mixing rate of polymer increased. As polymer was mixed $20\%$, national regulation of permeable concrete for pavement($8\%$ and 0.01cm/sec) was met. Compressive strength and flexural strength decreased as mixing rate of recycled aggregates increased but they increased a lot as mixing rate of polymer increased. Even when recycled aggregates were mixed $75\%\;with\;10\%$ polymer mixed, national regulation of pavement concrete(18MPa and 4.5MPa) was met. In addition, regarding sliding resistance, BPN increased as mixing rate of recycled aggregates increased. But BPN decreased as polymer was mixed. Compared to crushed stone aggregates, abrasion resistance and freeze-thaw resistance decreased as mixing rate of recycled aggregates Increased. When polymer was mixed, abrasion resistance and freeze-thaw resistance improved remarkably. Compared to non-mixture, $10\%$ mixture of polymer improved abrasion resistance and freeze-thaw resistance about $8.6\%$ and 3.8times respectively.

A Study on the Mechanical Properties of Steel Fiber Reinforced Porous Concrete for Pavement Using Slag Aggregate and Fly Ash (슬래그골재와 플라이애시를 이용한 강섬유 보강 포장용 투수콘크리트의 역학적 특성에 관한 실험적 연구)

  • Park, Seung-Bum;Lee, Jun;Jang, Young-Il;Lee, Byung-Jae
    • International Journal of Highway Engineering
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    • v.9 no.4
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    • pp.93-104
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    • 2007
  • This study evaluates the mechanical properties of steel fiber reinforced porous concrete for pavement according to content of slag aggregate and fly ash to elicit the presentation of data and the way to enhance its function for the practical field application of porous concrete as a material of pavement. As a result, void ratio and permeability coefficient of porous concrete for pavement increased a little as mixing rate of slag aggregates increased. Void ratio and permeability coefficient increased a lot as mixing rate of fly ash decreased. As fly ash was mixed, national regulation of permeable concrete for pavement(8% and 0.1 cm/sec) was met. Compressive strength and flexural strength decreased as mixing rate of slag aggregates increased, but they increased a lot as mixing rate of fly ash increased. Even when slag aggregates were mixed 50% with 5% fly ash mixed, national regulation of pavement concrete(18MPa and 4.5MPa) was met. In addition, compared to non-mixture, flexural strength increased about 22.8% when 0.75vol.% of steel fiber was added. Regarding sliding resistance, BPN increased as mixing rate of slag aggregates increased. But BPN decreased as fly ash was mixed. Compared to crushed stone aggregates, abrasion resistance and fleers-thaw resistance decreased as mixing rate of slag aggregates increased. When fly ash was mixed, abrasion resistance and freeze-thaw resistance improved remarkably. Compared to non-mixture, 10% mixture of fly ash improved abrasion resistance and freeze-thaw resistance about 5.6% and 14.3 respectively.

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A Study on the Fashion Accessary Product Development by Use of Korean Traditional Hanji (Part I) -Physical Properties of the Korean Traditional Paper(Hanji) Treated with Silcone resin- (전통한지를 활용한 패션 악세서리 상품개발 (제1보) -실리콘 수지로 처리된 한지의 물성변화-)

  • Kim Eun-Ah;Ryu Hyo-Seon;Kim Yong-Sook
    • Journal of the Korean Society of Clothing and Textiles
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    • v.30 no.3 s.151
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    • pp.481-486
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    • 2006
  • There are attempts to utilize Hanji for apparel material, but, the reason that the strength and durability of Hanji decrease to a great extent in the wet condition, restricts the usability of Hanji. In order to improve the resistance against water, Hanji was treated with silicone type water repellent agents. The treatment was carried out by conventional pad-dry-cure method. The optimum treatment condition was obtained by varying the concentration of repellent agent, curing temperature and time. Water repellency was tested by spray rating method. Wet and dry tensile strength, tearing resistance and abrasion resistance were examined after the treatment. Flexural stiffness and wrinkle recovery angles of hanji were also measured. In result, the optimum condition of treatment was at resin concentration of 40g/l, catalyst concentration of 20g/l(half of resin concentration), curing temperature of 160$^{circ}C$, curing time of 120 sec. Flexural stiffness of Hanji was hardly increased and wrinkle recovery angle of Hanji was improved a little by resin treatment. After the treatment, in dry condition, tensile strength and tearing resistance were little changed but abrasion resistance was improved. In wet condition, tensile strength, tearing strength and abrasion resistance were improved.

Preparation of Conductive Coating Solutions by Blending Waterborne Acrylic Polyurethane Dispersion with Carbon Nanotube (수분산 아크릴 폴리우레탄과 탄소나노튜브의 혼합에 의한 전도성 코팅용액 제조)

  • Huh, Woo Young;Yun, Dong Gu;Song, Ki Chang
    • Korean Chemical Engineering Research
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    • v.51 no.1
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    • pp.73-79
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    • 2013
  • Waterborne polyurethane dispersion (WPUD) was synthesized from polycarbonate diol (PCD), isophorone diisocyanate (IPDI) and dimethylol propionic acid (DMPA) as starting materials. Then, waterborne acrylic polyurethane dispersion (AUD) was synthesized by reacting the WPUD with an acrylate monomer, methyl methacrylate (MMA). Subsequently, the AUD was mixed with multi-walled carbon nanotube (MWCNT) to yield a conductive coating solution, and the mixture was coated on the polycarbonate substrate. With increasing the amount of MMA in the AUD, the pencil hardness, abrasion resistance and chemical resistance of the coating films were improved, but the electrical conductivity of the coating films was decreased. On the other hand, the pencil hardness, abrasion resistance and chemical resistance of coating films were decreased, but the electrical conductivity was enhanced with increasing the amount of MWCNT in the conductive coating solutions.

Assesment of Renewable Energy (신재생 에너지 고찰)

  • Lee, Sang-Heon;Koo, Kyoung-Whan
    • Proceedings of the KIEE Conference
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    • 2011.07a
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    • pp.2071-2072
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    • 2011
  • Withstand voltage characteristics of the nanocomposites, as a material with excellent abrasion resistance and water resistance, low shrinkage upon curing with moisture even in very good adhesion, workability is not lost. In this study, the fusion of nanoparticles and the high functionality epoxy nano-composite material produces the electricity. Degeneration of the unit based on this power structure and breakdown characteristics, efficiency and cross-measurement system as closely related organisms that can be applied to the power plant electrical efficiency of the nano-composite material is designed to develop skills.

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Soil Resistant and Blood Repellent Finishes of Nonwoven Fabrics Using Foam (거품을 이용한 부직포의 방오방혈가공)

  • 이정민;배기서;노덕길;전병열
    • Textile Coloration and Finishing
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    • v.4 no.3
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    • pp.74-81
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    • 1992
  • Chemical bonded nonwoven fabric for apparel use and spunlaced nonwoven fabric for medical use were finished for soil resistance and blood replellency with fluorochemicals utilizing foam finishing technology (FFT) and conventional padding application techniques. The FFT process improved soil and abrasion resistance properties of nonwoven fabrics compared with the conventional padding process. Excellent water-oil-saline-alcohol repellency values and water impact penetration values were obtained in the spunlaced nonwoven fabrics with both techniques.

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Study on the Development of SiC-containing Technical Porecelain Body (SiC 질 공업용 도자기 개발에 관한 연구)

  • 박정현;배원태;권오훈
    • Journal of the Korean Ceramic Society
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    • v.19 no.1
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    • pp.5-12
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    • 1982
  • SiC-containing by-product from the surface abrasion process of porcelain cores is used as a starting material to develop the SiC-containing technical porcelain bodies. To prevent the bloating phenomenon of by-product specimen at firing temperature, it is acid treated. In order to enhance the workability and to lower the firing temperature of bodies, clay is added. Body containing 25% clay and 75% by-product fired at 135$0^{\circ}C$ showes extremely high thermal shock resistance and acid resistance.

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A Study on Property Change with Mixing Ratio in NBR/PVC Composites

  • Li, Xiang Xu;Jeong, Hyung Seok;Cho, Ur Ryong
    • Elastomers and Composites
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    • v.53 no.2
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    • pp.48-51
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    • 2018
  • 10, 20, 30, and 40% of polyvinyl chloride (PVC) were added to nitrile butadiene rubber (NBR) to modify the latter. The NBR/PVC composites containing pure NBR were synthesized to investigate properties, such as crosslinking density, hardness, tensile strength, abrasion resistance, heat resistance, solvent resistance, and filler dispersion. The experimental result revealed a decrease in crosslinking density and heat resistance with increase in the PVC content. In contrast, addition of PVC to NBR resulted in enhancement of hardness, tensile strength, solvent resistance, and filler dispersion.

Effects of Alloying Elements and Heat-Treatments on Abrasion Wear Behavior of High Alloyed White Cast Iron

  • Yu, Sung-Kon
    • Journal of Korea Foundry Society
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    • v.20 no.2
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    • pp.104-109
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    • 2000
  • Three different white cast irons alloyed with Cr, V, Mo and W were prepared in order to study their abrasion wear behavior in as-cast and heat-treated conditions. The specimens were produced using a 15㎏-capacity high frequency induction furnace. Melts were super-heated to $1600^{\circ}C$, and poured at $1550^{\circ}C$ into Y-block pepset molds. Three combinations of the alloying elements were selected so as to obtain the different types of carbides : 3%C-10%Cr-5%Mo-5%W(alloy No. 1: $M_7C_3$ and $M_6C$), 3%C -10%V-5%Mo-5%W(alloy No. 2: MC and $M_2C$) and 3%C-17%Cr-3%V(alloy No. 3: $M_7C_3$ only). A scratching type abrasion test was carried out in the states of as-cast(AS), homogenizing(AH), air-hardening(AHF) and tempering(AHFT). First of all, the as-cast specimens were homogenized at $950^{\circ}C$ for 5h under the vacuum atmosphere. Then, they were austenitized at $1050^{\circ}C$ for 2h and followed by air-hardening in air. The air-hardened specimens were tempered at $300^{\circ}C$ for 3h. 1 ㎏ load was applied in order to contact the specimen with abrading wheel which was wound by 120 mesh SiC paper. The wear loss of the test piece(dimension: $50{\times}50{\times}5$ mm) was measured after one cycle of wear test and this procedure was repeated up to 8 cycles. In all the specimens, the abrasion wear loss was found to decrease in the order of AH, AS, AHFT and AHF states. Abrasion wear loss was lowest in the alloy No.2 and highest in the alloy No.1 except for the as-cast and homogenized condition in which the alloy No.3 showed the highest abrasion wear loss. The lowest abrasion wear loss of the alloy No.2 could be attributed to the fact that it contained primary and eutectic MC carbides, and eutectic $M_2C$ carbide with extremely high hardness. The matrix of each specimen was fully pearlitic in the as-cast state but it was transformed to martensite, tempered martensite and austenite depending upon the type of heat-treatment. From these results, it becomes clear that MC carbide is a significant phase to improve the abrasion wear resistance.

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