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Experimental and theoretical approach to determination of heat evolution in electrically conductive aluminosilicates

ABSTRACT
Design of progressive building materials with increased utility value is the key issue for the development of reliable modern building structures. Compared to the conventional materials, progressive building materials are supposed to exhibit not just adequate mechanical, and thermal properties, but they are also supposed to be applicable in sophisticated solutions, such as in self-sensing, self-heating or magnetic-shielding systems. In terms of electric properties, the most of building materials are electric insulators which is the main limiting factor for their applicability in such sophisticated solutions. However, this deficiency can be solved by the addition of a proper amount of electrically conductive admixtures. Within the paper, electrically conductive alkali-activated aluminosilicate with 8.89 mass% of carbon black admixture was designed and its materials properties necessary for calculations of heat evolution by the action of an electric source were experimentally determined. The electrical conductivity of such material equal to 5.57×10-2 S m-1 was sufficiently high to ensure self-heating ability. It was observed good agreement of experimentally determined data with those modeled by means of heat equation on sample with dimensions 40 × 40 × 10 mm. Finally, one- and two-layered large-scaled heating elements based on materials with experimentally determined properties were designed and calculations were conducted to determine the voltage level necessary for one-hour heating from 268.15 K and 273.15 K to 278.15 K in the middle-top point of the construction.
KEYWORDS
PAPER SUBMITTED: 2018-03-27
PAPER REVISED: 2018-11-02
PAPER ACCEPTED: 2018-11-09
PUBLISHED ONLINE: 2018-12-16
DOI REFERENCE: https://doi.org/10.2298/TSCI180327313F
REFERENCES
  1. Mineral Commodity Summaries 2017, minerals.usgs.gov/minerals/pubs/commodity/cement/mcs-2017-cemen.pdf.
  2. Ali, M. B. et al., A review on emission analysis in cement industries, Renewable and Sustainable Energy Reviews, 15 (2011), 5, pp. 2252-2261
  3. Deventer, J. S. J. et al., Chemical Research and Climate Change as Drivers in the Commercial Adoption of Alkali Activated Materials, Waste and Biomass Valorization, 1 (2010), 1, pp. 145-155
  4. Jerman, M. and Černý, R., Hydration heat of alkali activated fine-grained ceramic, AIP Conference Proceedings (Simos, T., Tsitouras, C.), International Conference on Numerical Analysis and Applied Mathematics (ICNAAM), Rhodes, Greece, 2017, Vol. 1863, UNSP 290006-1
  5. Duxson, P. et al., Geopolymer technology: the current state of the art, Journal of Materials Science, 42 (2007), 9, pp. 2917 -2933
  6. Fernández-Jiménez, A. et al., Durability of Alkali-Activated Fly Ash Cementitious Materials, Journal of Materials Science, 42 (2007), 9, pp. 3055-3065
  7. Fernández-Jiménez, A. et al., Steel passive state stability in activated fly ash mortars, Materiales de Construcción, 60 (2010), 300, pp. 51-65
  8. Torres-Carrasco, M.. et al., Durability of alkali-activated slag concretes prepared using waste glass as alternative activator, ACI Materials Journal, 112 (2015), 6, pp. 791-800
  9. Zuda, L. and Černý, R., Measurement of linear thermal expansion coefficient of alkali-activated aluminosilicate composites up to 1000 °C, Cement & Concrete Composites, 31 (2009), pp. 263-267
  10. Zuda, L. et al., Thermal properties of alkali-activated aluminosilicate composite with lightweight aggregates at elevated temperatures, Fire and Materials, 35 (2011), 4, pp. 231-244
  11. Sihai, W. and Chung, D. D. L., Electrical-resistance-based damage self-sensing in carbon fiber reinforced cement, Carbon, 45 (2007), 4, pp. 710-716
  12. Han, B. et al., A self-sensing carbon nanotube/cement composite for traffic monitoring, Nanotechnology, 20 (2009), 44, 445501
  13. Minging, S. et al., Experimental studies on the indoor electrical floor heating system with carbon black mortar slabs, Energy and Buildings, 40 (2008),6, pp. 1094-1100
  14. Won, J. et al., Thermal characteristics of a conductive cement-based composite for a snow-melting heated pavement system, Composite Structures, 118 (2014), pp. 106-111
  15. Xie, N. et al., Percolation backbone structure analysis in electrically conductive carbon fiber reinforced cement composites, Composites: Part B, 43 (2012), pp. 3270-3275
  16. Han, B. et al., Intrinsic self-sensing concrete and structures: A review, Measurement, 59 (2015), pp. 110-128
  17. EN 197-1: Cement. Composition, specifications and conformity criteria for common cements, 2000
  18. Applied Precision, Isomet 2104 - Portable heat transfer analyzer (Applied Precision Ltd., 2011), www.appliedp.com/en/isomet.htm. Accessed 10 October 2017
  19. Fiala, L. et al., Modeling of heat evolution in silicate building materials with electrically conductive admixtures, AIP Conference Proceedings (Simos, T. E., Kalogiratou, Z., Monovasilis, T.), International Conference of Computational Methods in Sciences and Engineering (ICCMSE), 2016, Athens, Greece, Vol. 1790, UNSP 150012
  20. ČSN EN 73 0540-3: Thermal protection of buildings - Part 3: Design value quantities, 2005