Polyamide-66/Glass fiber 블렌드 조성물의 물리적 특성및 안경테 소재로써의 적용성에 관한 연구

손진영,이지은,최경만,배유환,김기홍 한국안광학회 2013 한국안광학회지 Vol.18 No.4

Purpose: In this study, we evaluated the physical and thermal properties of the compositions made by blending glass fiber (GF) of different contents into glass fiber polyamide-66, and investigated if the compositions applying to the glasses frame to replace the TR-90, which is polyamide-12 resin used as an injection-type spectacle frame material. Methods: To investigate the characteristics change of polyamide-66 (PA-66) compositions with the change of the content of glass fibers, we produced a composition of the content by using a twin-screw extruder. The mechanical strength of the composition production was measured and coating properties as well as cutting processability were evaluated. We evaluated the applicability of the glasses frame by comparison the results of new compositions with characterizations of traditional TR. Results: For the results of the characterization of Polyamide-66/GF composition, we found that the higher increase of content of the glass fiber, the less mold shrinkage rate, and the mechanical strength was increased. Tensile strength increased from 498 kg/cm2 for 0 wt%of the content of the glass fibers to 849 kg/cm2 for 30 wt% of the content of the glass fibers. As a result of a coating evaluation, the strength of coating was 4B in the GF 5wt% and 5B, which was extremely good coating characteristics, in the over than GF 5 wt%. Conclusions: In case that 30 wt% of the glass fiber was blended, the mechanical strength was greatly improved, the hardness was increased, injection temperature increased due to increase of the viscosity, and the flow mark of the product may occur. The paint coating of PA-66 blended with glass fiber was all excellent. With general evaluating physical properties and workability properties it was determined that around 10 wt% of the content of the glass fibers was possible to apply a spectacle frame. 목적: 본 연구에서는 사출형 안경테 소재로 사용되고 있는 폴리아미드-12 수지인 TR-90을 대체하기 위하여폴리아미드-66에 유리섬유(glass fiber)를 함량별로 블렌드하여 각 조성물의 물리적, 열적 특성을 평가하여안경테로써의 적용 가능성을 검토하였다. 방법: 유리섬유의 함량 변화에 따른 폴리아미드-66 조성물의 특성변화를 고찰하기 위해 이축압출기를 이용하여 함량별 조성물을 제조하였다. 제조된 조성물의 기계적강도,열적 특성, 코팅성 및 절삭가공성을 평가하였다. 이를 통하여 기존 TR 안경테 제품과의 성능 비교 및 안경테로써 적용 가능성을 평가하였다. 결과: 폴리아미드-66/유리섬유 조성물의 특성 평가 결과, 유리섬유의 함량이 증가할수록 성형수축율이 감소하며, 기계적 강도가 증가하는 것으로 나타났다. 유리섬유의 함량이0 wt%인 경우 인장강도는 498 kg/cm2에서 30 wt%가 함유된 경우 849 kg/cm2 까지 증가하였다. 코팅성 평가결과 유리섬유 5 wt%에서는 코팅강도가 4 B였고, 그 이상에서는 5 B로 매우 우수한 코팅 특성을 나타내었다. 결론: 30 wt%의 유리섬유가 블렌드된 경우 기계적 강도가 크게 향상되나 이와 더불어 경도가 상승되며, 점도가 증가하여 사출온도가 높아지며, 제품에 플로우 마크가 생기는 것으로 나타났다. 유리섬유가 블렌드된폴리아미드-66의 도료 코팅성은 모두 우수하였다. 전반적으로 물성 및 가공성 등을 평가해볼 때, 유리섬유의 함량이 약 10 wt% 내외의 경우 안경테로써의 적용이 가능하다고 판단된다.

EVALUATION OF SEISMIC SHEAR CAPACITY OF PRESTRESSED CONCRETE CONTAINMENT VESSELS WITH FIBER REINFORCEMENT

전영선 한국원자력학회 2015 Nuclear Engineering and Technology Vol.47 No.6

Background: Fibers have been used in cement mixture to improve its toughness, ductility,and tensile strength, and to enhance the cracking and deformation characteristics ofconcrete structural members. The addition of fibers into conventional reinforced concretecan enhance the structural and functional performances of safety-related concrete structuresin nuclear power plants. Methods: The effects of steel and polyamide fibers on the shear resisting capacity of aprestressed concrete containment vessel (PCCV) were investigated in this study. For acomparative evaluation between the shear performances of structural walls constructedwith conventional concrete, steel fiber reinforced concrete, and polyamide fiber reinforcedconcrete, cyclic tests for wall specimens were conducted and hysteretic models werederived. Results: The shear resisting capacity of a PCCV constructed with fiber reinforced concretecan be improved considerably. When steel fiber reinforced concrete contains hooked steelfibers in a volume fraction of 1.0%, the maximum lateral displacement of a PCCV can beimproved by > 50%, in comparison with that of a conventional PCCV. When polyamide fiberreinforced concrete contains polyamide fibers in a volume fraction of 1.5%, the maximumlateral displacement of a PCCV can be enhanced by ~40%. In particular, the energy dissipationcapacity in a fiber reinforced PCCV can be enhanced by > 200%. Conclusion: The addition of fibers into conventional concrete increases the ductility andenergy dissipation of wall structures significantly. Fibers can be effectively used to improvethe structural performance of a PCCV subjected to strong ground motions. Steel fibers aremore effective in enhancing the shear performance of a PCCV than polyamide fibers.

Workability and Mechanical Properties of Hybrid Fiber Reinforced Concrete Using Amorphous Steel Fiber and Polyamide Fiber

Soon-Oh Kwon,Su-Ho Bae,Hyun-Jin Lee,Yo-Seb Kim,Jin Jun,Wha-Jung Kim 한국건설순환자원학회 2016 한국건설순환자원학회 논문집 Vol.4 No.4

Many studies have been performed on hybrid fiber reinforced concrete for years, which is to improve some of the weak material properties of concrete. Studies on characteristics of hybrid fiber reinforced concrete using amorphous steel fiber and polyamide fiber, however, yet remain to be done. The purpose of this experimental research is to evaluate the workability and mechanical properties of hybrid fiber reinforced concrete using amorphous steel fiber and polyamide fiber. For this purpose, the hybrid fiber reinforced concrete containing amorphous steel fiber(ASF) and polyamide fiber(PAF) were made according to their total volume fraction of 0.5 % for water-binder ratio of 33 %, and then the mechanical properties such as the compressive strength, direct tensile strength, flexural strength, and flexural toughness of those were estimated. It was observed from the test results that the compressive strength was slightly decreased with increasing ASF and decreasing PAF and the effect of fiber combination on the flexural strength was not much but the flexural toughness was relatively largely increased with decreasing ASF and increasing PAF.

보강섬유의 형상과 물성에 따른 인발특성이 콘크리트의 휨거동에 미치는 영향

김홍섭,남정수,김정현,한상휴,김규용 한국구조물진단유지관리공학회 2014 한국구조물진단유지관리공학회 논문집 Vol.18 No.5

본 연구에서는 섬유종류에 따른 인발특성과 섬유보강 콘크리트의 휨특성에 대하여 평가하기 위하여, 섬유의 재질 및 형상 다른 후크형강섬유, 비정질 강섬유 및 폴리아미드 섬유에 대하여 인발시험과 섬유보강 콘크리트 시험체를 제작하여 휨특성을 평가하였다. 그 결과, 후크형 강섬유의 경우 최대인발하중에서 섬유가 매트릭스로부터 인발되었지만, 비정질 강섬유는 섬유와 매트릭스의 부착강도가 섬유자체의인장강도보다 높아 섬유가 매트릭스로부터 인발되지 않고 파괴되는 현상을 나타내었다, 한편, 폴리아미드 섬유는 연신율에 의해 최대인발하중까지 변위가 크게 발생하였으며, 최대하중이후에 섬유가 끊어지는 파괴특성을 나타내었다. 섬유보강 콘크리트의 휨특성에 있어서 비정질 강섬유는 매트릭스와의 부착강도가 높고, 섬유의 혼입개체수가 많아 콘크리트의 최대휨강도는 높았지만, 균열발생 이후 섬유가 매트릭스로부터 인발되지 않고 섬유가 파괴되는 것에 의해 응력의 저하가 급격하게 발생하지만, 후크형 강섬유보강 콘크리트는 균열발생 이후 섬유가 인발되면서 응력의 저하가 완만하게 발생하였다. 폴리아미드 섬유보강 콘크리트는 균열발생이후 섬유의 연신률에 의해 응력이 급격하게 저하하는 구간이 발생하였으며, 섬유와 매트릭스의 부착에 의해 재상승하였다가 섬유가 끊어지면서 파괴되었다. 섬유와 매트릭스의 인발특성은 섬유보강 콘크리트의 휨강도 및 변형 능력에 큰 영향을 미치는 것으로 판단된다. This study evaluated the bonding property of fiber and flexural behavior of fiber reinforced concrete. Amorphous steel fiber, hooked steel fiber and polyamide fiber was used for evaluation of bonding property and flexural behavior. As a result, the hookedsteel fiber was pulled out from matrix when peak stress. However amorphous steel fiber occurred shear failure because bondingstrength between fiber and matrix was higher than tensile strength of fiber. Polyamide fibers occurred significantly displacement to peak stress because of elongation of fiber. After that peak stress, fiber was cut off. Amorphous steel fiber reinforced concrete had a greater maximum flexural load compared with hooked steel fiber reinforced concrete because bonding performance between fiber and matrix was high and mixed population of fiber was many. However flexural stress was rapidly reduced in load-deflection curve because of shear failure of fiber. Flexural stress of hooked steel fiber reinforced concrete was slowly reduced because fiber was pulled out from the matrix. In the case of polyamide fiber reinforced concrete, flexural stress was rapidly lowered because of elongation of fiber. However flexural stress was increased again because of bonding property between polyamide fiber and matrix.The pull-out properties of the fiber and matrix has effect on the deformation capacity and flexural strength of fiber reinforced concrete.

보강섬유의 형상과 물성에 따른 인발특성이 콘크리트의 휨거동에 미치는 영향

김홍섭,남정수,김정현,한상휴,김규용 한국구조물진단유지관리공학회 2014 한국구조물진단유지관리공학회 논문집 Vol.18 No.5

This study evaluated the bonding property of fiber and flexural behavior of fiber reinforced concrete. Amorphous steel fiber,hooked steel fiber and polyamide fiber was used for evaluation of bonding property and flexural behavior. As a result, the hookedsteel fiber was pulled out from matrix when peak stress. However amorphous steel fiber occurred shear failure because bondingstrength between fiber and matrix was higher than tensile strength of fiber. Polyamide fibers occurred significantly displacement topeak stress because of elongation of fiber. After that peak stress, fiber was cut off. Amorphous steel fiber reinforced concrete hada greater maximum flexural load compared with hooked steel fiber reinforced concrete because bonding performance between fiberand matrix was high and mixed population of fiber was many. However flexural stress was rapidly reduced in load-deflection curvebecause of shear failure of fiber. Flexural stress of hooked steel fiber reinforced concrete was slowly reduced because fiber waspulled out from the matrix. In the case of polyamide fiber reinforced concrete, flexural stress was rapidly lowered because ofelongation of fiber. However flexural stress was increased again because of bonding property between polyamide fiber and matrix. The pull-out properties of the fiber and matrix has effect on the deformation capacity and flexural strength of fiber reinforcedconcrete. 본 연구에서는 섬유종류에 따른 인발특성과 섬유보강 콘크리트의 휨특성에 대하여 평가하기 위하여, 섬유의 재질 및 형상 다른 후크형강섬유, 비정질 강섬유 및 폴리아미드 섬유에 대하여 인발시험과 섬유보강 콘크리트 시험체를 제작하여 휨특성을 평가하였다. 그 결과, 후크형 강섬유의 경우 최대인발하중에서 섬유가 매트릭스로부터 인발되었지만, 비정질 강섬유는 섬유와 매트릭스의 부착강도가 섬유자체의인장강도보다 높아 섬유가 매트릭스로부터 인발되지 않고 파괴되는 현상을 나타내었다, 한편, 폴리아미드 섬유는 연신율에 의해 최대인발하중까지 변위가 크게 발생하였으며, 최대하중이후에 섬유가 끊어지는 파괴특성을 나타내었다. 섬유보강 콘크리트의 휨특성에 있어서 비정질 강섬유는 매트릭스와의 부착강도가 높고, 섬유의 혼입개체수가 많아 콘크리트의 최대휨강도는 높았지만, 균열발생 이후 섬유가 매트릭스로부터 인발되지 않고 섬유가 파괴되는 것에 의해 응력의 저하가 급격하게 발생하지만, 후크형 강섬유보강 콘크리트는 균열발생 이후 섬유가 인발되면서 응력의 저하가 완만하게 발생하였다. 폴리아미드 섬유보강 콘크리트는 균열발생이후 섬유의 연신률에 의해 응력이 급격하게 저하하는 구간이 발생하였으며, 섬유와 매트릭스의 부착에 의해 재상승하였다가 섬유가 끊어지면서 파괴되었다. 섬유와 매트릭스의 인발특성은 섬유보강 콘크리트의 휨강도 및 변형 능력에 큰 영향을 미치는 것으로 판단된다.

변형 속도에 따른 후크형 강섬유 및 폴리아미드섬유보강 시멘트 복합체의 압축 및 인장강도 특성

김홍섭,김규용,이상규,손민재,남정수 한국구조물진단유지관리공학회 2017 한국구조물진단유지관리공학회 논문집 Vol.21 No.3

본 연구에서는 유압식 급속재하 시험 장치를 제작하여 변형 속도에 따른 후크형 강섬유 및 폴리아미드 섬유보강 시멘트 복합체의 압축강도 및 인장강도 특성을 평가하였다. 그 결과, 변형 속도가 증가함에 따라 압축강도, 최대 응력 점에서의 변형 및 탄성계수는 증가하였으 며, 섬유 종류 및 혼입률은 변형 속도에 의한 압축강도의 영향은 크지 않았다. 본 연구에서 평가된 압축강도의 DIF는 CEB-FIP model code 2010 에 비해 상회하였으며, ACI-349의 예측값과 유사한 경향이 나타났다. 인장특성의 경우에도 변형 속도가 증가함에 따라 인장강도와 변형능력 이 크게 향상되었다. 후크형 강섬유보강 시멘트 복합체는 변형 속도가 증가함에 따라 섬유와 매트릭스의 부착력이 증가하는 것에 의해 인장강 도와 변형능력이 크게 향상되었으며, 섬유가 매트릭스로부터 인발되는 파괴 특성이 나타났다. 한편, 폴리아미드 섬유보강 시멘트 복합체의 경 우 섬유와 매트릭스의 부착력이 크기 때문에 섬유가 매트릭스로부터 인발되지 않고 끊어지는 파괴 특성이 나타났으며, 폴리아미드 섬유보강 시멘트 복합체의 인장특성에 대한 변형 속도 효과는 섬유의 인장강도에 큰 영향을 받는 것으로 판단되었다. 이러한 결과로부터 폴리아미드 섬 유보강 시멘트 복합체의 인장강도에 대한 변형 속도의 효과는 후크형 강섬유의 부착력에 대한 민감도 보다 큰 것으로 사료된다. In this study, to evaluate the mechanical properties of fiber-reinforced cement composites by strain rate, hydraulic rapid loading test system was developed. And compressive and tensile strength of the hooked steel fiber and polyamide fiber reinforced cement composite were evaluated. As a result, the compressive strength, strain capacity and elastic modulus were increased with increasing strain rate. The effect of compressive strength by type and volume fraction of fibers was not significant. The dynamic increase factor(DIF) of the compressive strength was higher than that of the CEB-FIP model code 2010 and showed a trend similar to that of ACI-349. The tensile strength and strain capacity were increased with increasing strain rate. The hooked steel fibers were drawn from the matrix. The tensile strength and strain capacity of hooked steel fiber reinforced cement composites were increased as the strain rate increased. The tensile strength and deformation capacity of the fiber reinforced cement composites were increased. And, hooked steel fibers were drawn from the matrix. On the other hand, because the bonding properties of polyamide fiber and matrix is large, polyamide fiber was cut-off with out pullout from matrix. The strain rate effect on the tensile properties of polyamide fiber reinforced cement composites was found to be strongly affected by the tensile strength of the fibers.

CONTAINMENT PERFORMANCE EVALUATION OF PRESTRESSED CONCRETE CONTAINMENT VESSELS WITH FIBER REINFORCEMENT

전영선,박형규 한국원자력학회 2015 Nuclear Engineering and Technology Vol.47 No.7

Background: Fibers in concrete resist the growth of cracks and enhance the postcrackingbehavior of structures. The addition of fibers into a conventional reinforced concrete canimprove the structural and functional performance of safety-related concrete structures innuclear power plants. Methods: The influence of fibers on the ultimate internal pressure capacity of a prestressedconcrete containment vessel (PCCV) was investigated through a comparison of the ultimatepressure capacities between conventional and fiber-reinforced PCCVs. Steel andpolyamide fibers were used. The tension behaviors of conventional concrete and fiberreinforcedconcrete specimens were investigated through uniaxial tension tests andtheir tension-stiffening models were obtained. Results: For a PCCV reinforced with 1% volume hooked-end steel fiber, the ultimate pressurecapacity increased by approximately 12% in comparison with that for a conventionalPCCV. For a PCCV reinforced with 1.5% volume polyamide fiber, an increase of approximately3% was estimated for the ultimate pressure capacity. Conclusion: The ultimate pressure capacity can be greatly improved by introducing steel andpolyamide fibers in a conventional reinforced concrete. Steel fibers are more effective atenhancing the containment performance of a PCCV than polyamide fibers. The fiber reinforcementwasshown to bemore effective at a high pressure loading and a lowprestress level.

보강섬유의 종류에 따른 섬유보강 콘크리트의 휨특성

강영태 ( Kang Young-tai ),김규용 ( Kim Gyu-yong ),이보경 ( Lee Bo-kyeong ),이상규 ( Lee Sang-kyu ),김경태 ( Kim Gyeong-tae ),남정수 ( Nam Jeong-soo ) 한국건축시공학회 2017 한국건축시공학회 학술발표대회 논문집 Vol.17 No.2

In this study, the flexural behavior of fiber-reinforced concrete by fiber type were evaluated. As a result, the flexural strength of the hooked steel fiber-reinforced concrete(HSFRC) was lower than that of the amorphous metallic fiber reinforced concrete(AFRC), however it was shown strain-softening behavior by the pull-out of fiber. The flexural strength and the equivalent flexural strength of polyamide fiber-reinforced concrete(PAFRC) were lower than other specimens, but the equivalent flexural strength ratio was similar to that of AFRC. The flexural behavior of the fiber-reinforced concrete was associated with the bonding and pull-out properties of the fiber and matrix depending on the fiber type.

비정질 강섬유와 유기섬유를 이용한 하이브리드 섬유보강 콘크리트의 작업성 및 강도 특성

권순오 ( Soon Oh Kwon ),배수호 ( Su Ho Bae ),이현진 ( Hyun Jin Lee ),김진우 ( Jin Oo Kim ),이준철 ( Jun Cheol Lee ) 한국복합신소재구조학회 2015 복합신소재구조학회논문집 Vol.6 No.4

The purpose of this experimental research is to evaluate the workability and strength properties of hybrid fiber reinforced concrete containing amorphous steel fiber and organic fiber. For this purpose, the hybrid fiber reinforced concrete containing amorphous steel fiber(ASF) with polyamide(PA) and polyvinyl alcohol(PVA) fiber, respectively were made according to their total volume fraction of 0.5% for water-binder ratio of 33%, and then the characteristics such as the workability, compressive strength, and flexural strength of those were investigated. It was observed from the test results that the workability and compressive strength at 7 and 28 days were decreased and the flexural strength at 7 and 28 days was increased with increasing ASF and decreasing organic fiber.

하이브리드 섬유보강 콘크리트의 장기 건조수축 및 내동해성 평가

김요셉,배수호,이현진 한국구조물진단유지관리공학회 2019 한국구조물진단유지관리공학회 논문집 Vol.23 No.2

Many researches have been performed on hybrid fiber reinforced concrete for years, which is to improve some of the weak material properties of concrete. Researches on characteristics of hybrid fiber reinforced concrete using amorphous steel fiber and organic fiber, however, yet remain to be done. Therefore, the purpose of this research is to estimate the compressive strength, long term drying shrinkage, and resistance to freezing and thawing of hybrid fiber reinforced concrete(HFRC) using amorphous steel fiber and polyamide fiber as one of organic fibers. For this purpose, HFRCs containing amorphous steel fiber and polyamide fiber were made according to their total volume fraction of 1.0% for target compressive strength of 40 and 60 MPa, respectively, and then the compressive strength, length change, and resistance to freezing and thawing of these were evaluated. As a result, the long term length change ratio of HFRC used in this study decreased by more than 30%, 25% than plain concrete at 365 and 730 days, respectively, and the durability factor of HFRC was very excellent as more than 90%. 콘크리트의 낮은 인장강도 및 균열제어 능력 등의 약한 재료성질을 개선하기 위하여 수년간 하이브리드 섬유보강 콘크리트에 관한 많은 연구가 진행되어 왔다. 그러나 비정질 강섬유와 유기섬유를 이용한 하이브리드 섬유보강 콘크리트에 관한 연구는 이루어지지 않은 실정이다. 따라서, 본 연구의 목적은 비정질 강섬유와 유기섬유로서 폴리아미드 섬유를 이용한 하이브리드 섬유보강 콘크리트의 압축강도, 장기 건조수축 및 내동해성을 평가하는 것이다. 이를 위하여 목표 압축강도 40 및 60 MPa 각각에 대해서 하이브리드 섬유 혼입률을 전체 체적비로 1.0%로 설정하여 비정질 강섬유와 폴리아미드 섬유를 이용한 하이브리드 섬유보강 콘크리트를 제작하였다. 제작된 하이브리드 섬유보강 콘크리트의 장기 건조수축 및 내동해성을 평가한 결과, 재령 365일 및 730일에서의 장기 길이변화율은 플레인 콘크리트보다 각각 30%, 25% 이상 감소된 것으로 나타났으며, 동결융해 300 사이클 후의 내구성 지수는 90% 이상으로, 내동해성이 있는 것으로 나타났다.