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Direct Tensile Properties of Fiber-Reinforced Cement Based Composites according to the Length and Volume Fraction of Amorphous Metallic Fiber

비정질 강섬유의 길이 및 혼입률에 따른 섬유보강 시멘트복합체의 직접인장특성

Kim, Hong-Seop;Kim, Gyu-Yong;Lee, Sang-Kyu;Choe, Gyeong-Cheol;Nam, Jeong-Soo
김홍섭;김규용;이상규;최경철;남정수

  • Received : 2019.02.12
  • Accepted : 2019.04.18
  • Published : 2019.06.20

Abstract

In this study, the direct tensile properties of amorphous metallic fiber-reinforced cement based composites according to the strain was evaluated. A thin plate-shape amorphous metallic fiber with 15mm and 30mm in length was used. And fiber-reinforced cement based composites were prepared with contents of 1.0, 1.5, 2.0%. The direct tensile test was conducted under the conditions of $10^{-6}/s(static)$ and $10^1/s(dynamic)$ strain rate. As a results, amorphous metallic fiber with a length of 15mm was observed in pull-out behavior from the cement matrix because of the short fiber length and large portion of mixed fiber. On the other hand, amorphous metallic fiber with a length of 30mm were not pulled out from matrix because the bonding force between the fiber and matrix was large due to rough surface and large specific surface area. However, fracture occurred because thin plate shape fibers were vulnerable to shear force. Tensile strength, strain capacity and toughness were improved due to the increase in the fiber length. The dynamic increase factor of L15 was larger that of L30 because the bonding performance of the fiber-matrix interface is significantly affected by the strain rate.

Keywords

amorphous metallic fiber;direct tensile properties;strain rate;dynamic increase factor

References

  1. Park KW, Lee JS, Kim W, Kim DJ, Lee GY. Cracking behavior of RC tension members reinforced with amorphous steel fibers. Journal of the Korea Concrete Institute. 2014 Aug;26 (4):475-82. https://doi.org/10.4334/JKCI.2014.26.4.475 https://doi.org/10.4334/JKCI.2014.26.4.475
  2. Ku DO, Kim SD, Kim HS, Choi KK. Flexural performance characteristics of amorphous steel fiber-reinforced concrete. Journal of the Korea Concrete Institute. 2014 Aug;26(4):483-9. https://doi.org/10.4334/JKCI.2014.26.4.483 https://doi.org/10.4334/JKCI.2014.26.4.483
  3. Yoo DY, Banthia N., Yang JM, Yoon YS. Size effect in normal-and high-strength amorphous metallic and steel fiber reinforced concrete beams. Construction and Building Materials. 2016 Sep;121:676-85. https://doi.org/10.1016/j.conbuildmat.2016.06.040 https://doi.org/10.1016/j.conbuildmat.2016.06.040
  4. Choi SJ, Hong BT, Lee SJ, Won JP. Shrinkage and corrosion resistance of amorphous metallic fiber-reinforced cement composites. Composite Structures. 2014 Jan;107:537-43. https://doi.org/10.1016/j.compstruct.2013.08.010 https://doi.org/10.1016/j.compstruct.2013.08.010
  5. Kim HS, Kim GY, Nam JS, Kim JH, Han SH, Lee GY. Static mechanical properties and impact resistance of amorphous metallic fiber-reinforced concrete. Composite Structures. 2015 Dec;134:831-44. https://doi.org/10.1016/j.compstruct.2015.08.128 https://doi.org/10.1016/j.compstruct.2015.08.128
  6. Naaman A, Shah S. Pull-out mechanism in steel fiber-reinforced concrete. Journal of the Structural Divsion. 1976;102(8):1537-48.
  7. Chan Y, Chu S. Effect of silica fume on steel fiber bond characteristics in reactive powder concrete. Cement Concrete Research. 2004;34(7):1167-72. https://doi.org/10.1016/j.cemconres.2003.12.023 https://doi.org/10.1016/j.cemconres.2003.12.023
  8. Li V, Wang Y, Backer S. Effect of inclining angle, bundling and surface treatment on synthetic fibre pull-out from a cement matrix. Composites. 1990;21(2):132-40.https://doi.org/10.1016/0010-4361(90)90005-H https://doi.org/10.1016/0010-4361(90)90005-H
  9. Kim HS, Kim GY, Lee SK, Son MJ, Choe GC, Nam JS. Strain rate effects on the compressive and tensile behavior of bundle-type polyamide fiber-reinforced cementitious composites. Composites Part B. 2019 mar;160:50-65. https://doi.org/10.1016/j.compositesb.2018.10.008 https://doi.org/10.1016/j.compositesb.2018.10.008
  10. Nam JS, Shinohara Y, Atou T, Kim HS, Kim GY. Comparative assessment of failure characteristics on fiber-reinforced cementitious composite panels under high-velocity impact. Composites Part B. 2016 Aug;99:84-97. https://doi.org/10.1016/j.compositesb.2016.06.008 https://doi.org/10.1016/j.compositesb.2016.06.008
  11. Won JP, Hong BT, Choi TJ, Lee SJ, Kang JW. Flexural behaviour of amorphous micro-steel fibre-reinforced cement composites. Composite Structures. 2012 Mar;94(4):1443-9. https://doi.org/10.1016/j.compstruct.2011.11.031 https://doi.org/10.1016/j.compstruct.2011.11.031

Acknowledgement

Supported by : National Research Foundation of Korea(NRF)