• Journal of the Korea Concrete Institute
• /
• v.23 no.4
• /
• pp.461-469
• /
• 2011

In this study, the effect of polyvinyl alcohol (PVA) fiber volume fraction on the pullout behavior of structural synthetic fiber in hybrid structural synthetic fiber and PVA fiber cement composites are presented. Pullout behavior of the hybrid fiber cement composites and structural synthetic fiber were determined by dog-bone bond tests. Test results found that the addition of PVA fiber can effectively enhance the structural synthetic fiber cement based composites pullout behavior, especially in fiber interface toughness. Pullout test results of the structural synthetic fiber showed the interface toughness between structural synthetic fiber and PVA fiber reinforced cement composites increases with the volume fraction of PVA fiber. The microstructural observation confirms the incorporation of PVA fiber can effectively enhance the interface toughness mechanism of structural synthetic fiber and PVA fiber reinforced cement composites.

• Journal of the Korea Concrete Institute
• /
• v.15 no.5
• /
• pp.643-649
• /
• 2003

The purpose of this study were evaluated to flexural and bond performance by sectional area and geometry change through bond and flexural test of a structural synthetic fiber. Six deformed structural synthetic fibers were investigated and pullout and flexural test was conducted. Included parameters is three different geometries of fiber and two of fiber sectional area. The test result shows that the cycles and amplitude of structural synthetic fiber increased, pullout load and pullout fracture energy decreased and flexural strength increased, if sectional area is same. The sectional area increased, pullout load and pullout fracture energy increased and flexural strength decreased, if cycles and amplitude of structural synthetic fiber is same. Based on test results, structural performance of the concrete could know that is influence by pullout performance of fiber as well as various factor (fiber number, material properties etc).

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

• Journal of Korean Tunnelling and Underground Space Association
• /
• v.24 no.4
• /
• pp.317-326
• /
• 2022

This research performed single fiber pull-out test to evaluate the effect between fineness modulus of cement composites and the fiber bond performance (bond strength and pull-out energy). A synthetic fiber (polypropylene) and a steel fiber (hooked ends type) were inserted in the middle of dog bone shape specimens which were designed with fine aggregates of F. M. 1.96, 2.69, 3.43. The experiment results showed bond strength and pullout energy of synthetic fiber are improved as fineness modulus of cement composites increases. It is considered that the frictional resistance between synthetic fiber and cement composite increases as fineness modulus of cement composite increases and consume more energy while pull out the fiber from cement composite. However bond performance of steel fiber which resist pull out by mechanical behavior is less effected on fineness modulus of cement composite. It is considered that the mechanical fixedness of hooked ends exerts a greater effect on the pullout resistance than the frictional resistance between the cement composite and the steel fiber so F. M. of fine aggregate has a relatively small effect on the pullout resistance with the steel fiber.

• Journal of Korean Tunnelling and Underground Space Association
• /
• v.21 no.3
• /
• pp.433-452
• /
• 2019

This study deals with shotcrete reinforcing performance according to the amount of synthetic fiber (PP fiber) and proper evaluation method. The shotcrete compressive strength, flexural strength and flexural toughness were tested by setting the mixing amounts of steel fiber ($37.0kg/m^3$) and synthetic fiber (PP fiber) as parameters ($5.0kg/m^3$, $7.0kg/m^3$ and $9.0kg/m^3$). Particularly, circular panel flexural toughness test (Road and Traffic Authority, RTA) was performed to evaluate the shotcrete energy absorption capacity. As a result, the compressive strength and the bending strength of the steel fiber reinforced shotcrete were large, but the flexural toughness of the synthetic fibe (PP fiber) reinforced shotcrete was large. Therefore, synthetic fiber (PP fiber) reinforced shotcrete is considered to have a reinforcing effect comparable to that of steel fiber reinforced shotcrete. Analysis of the relationship between the flexural toughness and the energy absorption capacity of synthetic fiber (PP fiber) reinforced shotcrete revealed that the energy absorbing ability is exhibited at a flexural toughness lower than the allowable standard (3.0 MPa). (Class A: 2.55 MPa = 202J, Class B: 2.72 MPa = 282J, Class C: 3.07 MPa = 403J). As a result of this study, it can be concluded that the actual shotcrete support performance can be evaluated by evaluating the support performance of the shotcrete measured at less than the allowable standard (3.0 MPa) at the actual tunnel site.

• Proceedings of the Korean Fiber Society Conference
• /
• 2001.10a
• /
• pp.123-126
• /
• 2001

실크는 우수한 광택, 촉감, 물성을 바탕으로 하여 인류에 있어 최고의 의류용 섬유로서 널리 이용되어 왔으며 최근에는 생체적합성 등을 활용한 의료용 및 생물공학용 소재로서 응용하고자 하는 연구가 활발히 진행 중에 있다[1-2]. 그러나 실크의 경우 누에로부터 얻어지는 천연섬유로서 합성섬유와는 달리 누에로부터 토사되면서 그 구조 및 형태가 결정되어 고정되는 단점을 안고 있어 의류용 및 산업용 분야로의 활용에 있어 한계가 있다. (중략)

• Journal of the Korea Concrete Institute
• /
• v.14 no.4
• /
• pp.474-482
• /
• 2002

The purpose of the study is to establish an optimum geometry and optimum geometry factor through bond test of a structural synthetic fiber, which fully utilizes matrix anchoring without fiber fracturing with the maximum pullout resistance. Seven deformed structural synthetic fibers with widely different geometries were investigated and pullout test was conducted. Included parameters are seven different types of fiber and two of mortar matrixes. The test result shows that the crimped type structural synthetic fiber is significant improvement in the interface toughness(pullout energy) and pullout load. The pullout test was performed with various size of crimped type structural synthetic fiber in order to invest optimum geometry factor, In the basis of the test results, optimum geometry factor is established such as D=b$^{{\alpha}0{\alpha}}$h$^{λ{\beta}}$.

• Proceedings of the Korean Fiber Society Conference
• /
• 2002.04a
• /
• pp.111-114
• /
• 2002

실크는 우수한 광택, 촉감, 물성을 바탕으로 하여 인류에 있어 최고의 의류용 섬유로서 널리 이용되어 왔으며 최근에는 생체적합성 등을 활용한 의료용 및 생물공학용 소재로서 응용하고자 하는 연구가 활발하게 진행중이다[1-2]. 그러나 실크는 합성섬유와는 달리 누에가 토사하는 그 순간에 그 구조 및 형태가 결정되어 고정되는 단점을 안고 있어 다양한 특성이 요구되는 의류용 및 산업용 분야로의 응용에 한계가 있다. (중략)

• Geotechnical Engineering
• /
• v.39 no.3
• /
• pp.69-74
• /
• 2023

• Proceedings of the Korean Fiber Society Conference
• /
• 1998.10a
• /
• pp.178-182
• /
• 1998

폴리에스터섬유는 표면구조가 치밀하며, 표면이 평활하면서 높은 굴절율을 갖고 있고, 분자흡광계수가 낮은 분산염료로 염색하기 때문에 섬유표면에서의 빛의 반사가 강하게 되어 짙은 검정색을 얻는데에는 문제점이 있는 것으로 알려져 있다. (중략)