DOI QR코드

DOI QR Code

MWCNT가 첨가된 시멘트복합체의 수화 및 전기저항 특성

Hydration and Electrical Resistance of Cement Composites Containing MWCNTs

  • Lee, Gun-Cheol (Department of Architectural Engineering, Korea National University of Tranportation) ;
  • Kim, Young-Min (Department of Architectural Engineering, Korea National University of Tranportation)
  • 투고 : 2019.11.25
  • 심사 : 2020.02.07
  • 발행 : 2020.02.20

초록

탄소나노튜브는 우수한 역학성, 전기전도성 등으로 다양한 산업에 이용되고 있다. 건설산업에서는 구조체에 자기센싱 기능을 부여하는 연구가 진행되고 있지만, 연구자들마다 실험결과가 상이하게 나타나고 이에 대한 분석은 미비한 실정이다. 따라서 본 연구에서는 MWCNT가 첨가된 시멘트페이스트의 수화열, 공극률, 리트벨트 정량분석법, 압축강도, 거리에 따른 전기저항값을 측정하여 수화와 강도특성 및 전기특성을 분석하였다. 실험결과 수화열은 MWCNT가 증가할수록 감소되는 것으로 나타났다. 또한 XRD 리트벨트 정량분석법 결과 MWCNT 첨가율 증가에 따른 수화생성물의 양은 큰 차이가 없는 것으로 나타났고, 압축강도 저하의 원은은 공극률 분석결과 MWCNT가 시멘트페이스트내에서 공극의 양을 증가시겼기 때문으로 판단되며 SEM분석결과 MWCNT가 반데르발스힘에 의해 뭉쳐져 있어서 이 부위가 공극 및 취약부로 발생것으로 판단된다. 전기저항값은 첨가율이 증가될수록 감소하여 추후 자기센싱에 대한 역할을 할 수 있을 것으로 판단된다.

Carbon nanotubes are used in various industries with their excellent mechanical properties and electrical conductivity. In the construction industry, research is being conducted to give self-sensing capabilities to structures, but the results of experiments vary among researchers, and the analysis is insufficient. Therefore, in this study, the hydration and electrical properties of MWCNT-added cement pastes were measured. The electrical resistance values of hydration heat, porosity, Rietveld quantitative analysis, compressive strength, and distance were measured.. The heat resistance, porosity, Rietvelt quantitative analysis, compressive strength and distance were measured according to electrical resistance. Experimental results showed that the heat of hydration decreased with increasing MWCNT. XRD Rietveld quantitative analysis showed that there was no significant difference in the amount of hydration products with increasing addition rate of MWCNT. As a result of SEM analysis, the MWCNT is agglomerated by van der Waals forces, and this area is considered to be caused by voids and weak areas. The electrical resistance value decreases as the addition rate is increased, and thus may play a role for magnetic sensing in the future.

키워드

참고문헌

  1. Oh SW, Oh KS, Jung SH, Chung WS. Effects of CNT additions on mechanical properties and microstructures of cement. Journal of the Korea Institute for Structural Maintenance and Inspection. 2017 Nov;21(6):162-8. http://doi.org/10.11112/jksmi.2017.21.6.162
  2. Ha SJ, Kang ST, Lee JH. Strength of CNT cement composites with different types of surfactants and doses. Journal of the Korea Institute for Structural Maintenance and Inspection. 2015 Mar;19(2):99-107. http://dx.doi.org/10.11112/jksmi.2015.19.2.099
  3. Wong, EW, Sheehan, PE, Lieber CM. Nanobeam mechanics: elasticity, strength, and toughness of nanorods and nanotubes. Science. 1997 Sep;277(5334):1971-5. http://doi.org/10.1126/science.277.5334.1971
  4. Li H, Xiao, Hui GX, Yuaon J, Ou J. Microstructure of cement mortar with nano-particles. Science Direct Composites Part B: Engineering. 2004 Mar;35(2):185-9. http://doi.org/10.1016/S1359-8368(03)00052-0
  5. Ha SJ, Kang ST, Lee JH. Strength of CNT cement composites with different types of surfactants and doses. Journal of Korea Institute for Structural Maintenance Inspection. 2015 Mar;19(2):99-107. http://doi.org/10.11112/jksmi.2015.19.2.099
  6. Lee GW, Joong TH. Dispersion of carbon nanotubes (CNTs) and CNT-based transparent conductive films. Korea Industrial Chemistry News. 2007 Aug;10(4):8-19.
  7. Colins F, John L, Duan WH. The influences of admixtures on the dispersion, workability, and strength of carbon nanotube-opc paste mixture. Cement & Concrete Composites, 2012 Feb;34(2):201-7. http://doi.org/10.1016/j.cemconcomp.2011.09.013
  8. Kang ST, Park SH. Experimental Study on Improving Compressive Strength of MWCNT Reinforced Cementitious Composites. Journal of the Korea Concrete Institute. 2014 Feb;26(1):63-70. http://dx.doi.org/10.4334/JKCI.2014.26.1.063
  9. Han CG, Han MC, Lee DG. Influence of over-added ae water reducing agent on physical properties of the concrete. Journal of the Korea Concrete Institute. 2008 Feb;27(8):91-6. http://dx.doi.org/10.5345/JKIC.2008.8.1.091
  10. Park SS, Han SP, Jeon YH, Kim JY, Kim NJ. A comparative study on the characteristics of nanofluids to the shape of graphene and carbon nanotube. Journal of the Korean Solar Energy Society. 2013 Jun;33(3):99-106. http://dx.doi.org/10.7836/kses.2013.33.3.099
  11. Lee HY, Kang DH, Song YM, Chung WS. Heating experiment of CNT cementitious composites with single-walled and multiwalled carbon nanotubes. Journal of Nanomaterials. 2017 May;2017 (Article ID 3691509):1-12. http://doi.org/10.1155/2017/3691509
  12. Li GY, Wang PM, Zhao X. Mechanical behavior and microstructure of cement composites incorporating surface-treated multi-walled carbon nanotubes. Carbon. 2005 May;43(6):1239-45. http://doi.org/10.1016/j.carbon.2004.12.017
  13. Yoon IS. Influence of micro-structural characteristics of concrete on electrical resistivity. Journal of the Korea Institute for Structural Maintenance and Inspection. 2013 Nov;17(6):122-9. http://dx.doi.org/10.11112/jksmi.2013.17.6.122