Journal of the Korea Institute of Building Construction (한국건축시공학회지)

The Korean Institute of Building Construction (한국건축시공학회)
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A Study on the Spalling Properties of Polymer Modified Cement Mortar Using Polypropylene Fiber

폴리프로필렌 섬유를 혼입한 폴리머 시멘트 모르타르의 폭렬특성에 관한 연구

  • Kim, Min-Sung (Department of Architectural Engineering, Daejin University) ;
  • Sim, Sang-Rak (Department of Architectural Engineering, Daejin University) ;
  • Ryu, Dong-Woo (Department of Architectural Engineering, Daejin University)
  • Received : 2020.07.03
  • Accepted : 2020.08.04
  • Published : 2020.08.20
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Abstract

Polymer modified cement mortar (PCM) can improve the performance of adhesion strength, flexural strength, chemical resistance, etc., compared with cement mortar, and is widely used when repairing RC structures. However, PCM causes a burst in an environment with high temperature and fire rate, which causes problems in the stability of the structure. In this study, for the purpose of developing explosive reduction PCM, the polymer mixing ratio is 2%, 4%, 6%, the fiber length is 6mm, 12mm, 6+12mm, and the PP fiber mixing rate is 0.05 Vol% and 0.1 Vol%. Furnace heating experiment (600℃, 800℃) was carried out. As a result of comparative analysis of the explosive properties, it was confirmed that the explosive reduction effect due to the fiber incorporation was insufficient when the polymer mixing amount was 6% or more.

기존 폴리머 시멘트 모르타르(PCM)는 일반적인 시멘트 모르타르에 비해 부착강도, 휨강도, 내약품성 등의 성능을 향상시킬 수 있어 철근콘크리트(RC)구조물의 보수·보강 시 폭넓게 사용하고 있다. 하지만 PCM은 화재와 같은 고온 환경에서 폭렬발생 가능성이 높아 구조안전성에 문제를 발생시킨다. 본 연구에서는 폭렬저감 PCM 개발을 목적으로 폴리머 혼입률(2%, 4%, 6%), PP 섬유길이(6mm, 12mm, 6+12mm), PP 섬유혼입률(0.05 Vol%, 0.1 Vol%)을 실험인자로 선정하여 전기로 가열실험(600℃, 800℃)을 진행하였다. 폭렬특성을 비교분석한 결과 폴리머 혼입률이 6% 이상인 경우에는 섬유혼입에 따른 폭렬저감 효과를 기대할 수 없었다.

Keywords

References

  1. Kim HJ, Park JY, Suh HW, Cho BY, Park WJ, Bae SC. Mechanical degradation and thermal decomposition of Ethylene-Vinyl Acetate(EVA) Polymer-modified Cement Mortar(PCM) exposed to high-temperature. Sustainability. 2019 Jan;11(2):1-18. https://doi.org/10.3390/su11020500
  2. Jang KY, Ryu DW. Residual bond strength of polymer-modified mortars using re-dispersible polymer powder at elevated temperature. Journal of the Korea Concrete Institute. 2019 Apr;31(4):339-46. http://doi.org/10.4334/JKCI.2019.31.4.339
  3. Yoshida M, Ikeda K, Kuroiwa S, Sakaguchi A. Outline of recommendations of diagnosis and repair methods of fire-damaged buildings. Architectural Institute of Japan. 2010. p. 1-217.
  4. Maluk C, Bisby L, Terrasi GP. Effects of polypropylene fibre type and dose on the propensity for heat-induced concrete spalling. Engineering Structures. 2017 Jun;141:584-95. https://doi.org/10.1016/j.engstruct.2017.03.058
  5. Won JP, Kang HB, Lee SJ, Lee SW, Kang JW. Thermal characteristics of high-strength polymer-cement composites with lightweight aggregates and polypropylene fiber. Construction and Building Materials. 2011 Oct;25(10):3810-9. https://doi.org/10.1016/j.conbuildmat.2011.03.023
  6. Chang CI, Yoo DR, Yum HS. An experimental study on properties of polymer cement concrete with a kind of admixtures. Journal of the Korea Institute for Structural Maintenance Inspection. 2004 Apr;8(1):121-8.
  7. Bae SC, Hyung WG. Properties of polymer modified mortars using re-dispersible polymer powders. Journal of the Korea Institute of Building Construction. 2013;13(3):235-41. http://dx.doi.org/10.5345/JKIBC.2013.13.3.235
  8. Yang KH. Slump and mechanical properties of hybrid steel-pva fiber reinforced concrete. Journal of the Korea Concrete Institute. 2010 Oct;22(5):651-8. https://doi.org/10.4334/JKCI.2010.22.5.651
  9. Karimipour A, Ghalehnovi M, Brito JD, Attari M. The effect of polypropylene fibres on the compressive strength, impact and heat resistance of self-compacting concrete. Structures. 2020 Jun;20:72-87. https://doi.org/10.1016/j.istruc.2020.02.022
  10. Kim DJ, Han BC, Lee JY, Harada K, Kwon YJ. The influence of compressive strength and moisture contents on explosive spalling of concrete. Fire Science and Engineering. 2011 Feb;25(1):42-9.
  11. Kim DJ, Lee JY, Harade K, Kwon YJ. Relation between explosive spalling and pore structure of high-strength concrete. Proceedings of the Korea Institute of Fire Science and Engineerig Conference. 2011 Apr;2011(Spring):89-93.
  12. Hertz KD. Limits of spalling of fire-exposed concrete. Fire Safety Journal. 2003 Mar;38(2):103-16. https://doi.org/10.1016/S0379-7112(02)00051-6