International Scientific Journal

Thermal Science - Online First

online first only

Model for the analysis of thermal conductivity of composite material of natural origin

Thermal properties of the wall structure elements made from gel and straw ("Ethno-eco-passive houses") have been investigated. The gel was made from a mixture of clay, lime and water. A one dimensional (1D) mathematical model based on the continuum mechanics, for predicting the thermal conductivity, is proposed. The results obtained by applying the proposed mathematical model were compared with the measurement data of experimental tests, using the Isomet 2114 instrument. The program envisages the measurement of thermal conductivity of three specimens, 5 year old, comprising three series within 365 days. In the theoretical analysis, the same parameters of thermal stability were treated as in the experiment. The average value of the material thermal conductivity is 0.0990 W/mK, so it can be concluded that, the composite material intended for the envelope of the proposed constructive system "Ethno-eco-passive house" is verified as thermally suitable.
PAPER REVISED: 2019-05-02
PAPER ACCEPTED: 2019-05-20
  1. Miličić, I.M.: Conceptual design "Ethno-eko-passive house" with plate elements made form composite natural material, Faculty of Civil Engineering, Subotica, Serbia, 2010
  2. Milanović, R.A, Folić-Kurtović, N., Folić, R.: Earth-Sheltered House: A Case Study of Dobraca Village House near Kragujevac, Serbia, Sustainability 2018, 10, 3629; doi:10.3390/su10103629
  3. Ferreira, M.G.P.R.: Experimental study of the Thermal Behavior on Green Façades, Extended Abstract, Instituto Superior Técnico, Lisboa, 2015
  4. Ilinčić, N., Miličić, I.: Primena savremenih tehnologija građenja u Subotici i uzroci neuspeha, Proceedings, Tehnologija građenja -građevinski menadžment '97, Subotica, 1997, pp. 19-28 (in Serbian)
  5. Jarić, J.: Mehanika kontinuuma, Građevinska knjiga, Beograd, 1988 (in Serbian)
  6. Lienhard, IV H.J., Lienhard, V H.J.: A Heat Transfer Textbook. Phlogiston Press Cambridge, Massachusetts, 2003
  7. Bowles, D.E., Tompkins, S.S.: Prediction of Coefficients of Thermal Expansion for Unidirectional Composites, Journal of Composite Materials, Vol 23 (1998), Issue 4, pp. 370-388,
  8. Bažant, Z. P., Kaplan, M. F.: Concrete at High Temperatures: Material Properties and Mathematical Models, Concrete design and construction series. Longman Group Limited, Harlow, 1996, pp. 412
  9. Beneš, M., Štefan, R., Zeman, J.: Analysis of coupled transport phenomena in concrete at elevated temperatures. In Applied Mathematics and Computation, 219(2013), 13, pp. 7262-7274
  10. Oka, S.N.: National energy efficiency program: Foundation, strategy, priorities formulation, and implementation activities. Termotehnika, 28 (2002), 1-4, str. 13-23
  11. Balocco, C.: A simple model to study a ventilated facade energy performance, Energy and Buildings, 34 (2002), pp. 469-475
  12. Blomberg, T.: Computer programs for transient and steady-state heat conduction in three dimensions HEAT3. Sweden: Department of building physics, Lund University, www.
  13. Pietrak, K., Wisniewak, T.S.: A review of models for effective thermal conductivity of composite materials, Journal of Power Technologies,95(2015), 1, pp. 14-24
  14. Mityushev, V.V., Pesetskaya, E., Rogosin, S. V.: Analytical Methods for Heat Conduction in Composites and Porous Media, Cellular and Porous Materials: Thermal Properties Simulation and Prediction. Edited by Andreas Ochsner, Graeme E. Murch, and Marcelo, J.S. de Lemos, Copyright WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim, 2008
  15. Ran, Z., Yan, Y., Li, J., Qi, Z., Yang, L.: Determination of thermal expansion coefficients for unidirectional fiber-reinforced composites, Chinese Journal of Aeronautics, Vol.27 (2014), Issue 5, pp 1180-1187,
  16. Tang, K.T.: Mathematical Methods for Engineers and Scientists 3, Springer Berlin Heidelberg New York, 2007
  17. CEN European Committee for Standardization (1996) Building components and building elements-thermal resistance and thermal transmittance: Calculation method. Brussels, Ref. br. EN ISO 6946:1996
  18. PTC, MathCAD 14.0, User's Guide, February 2007.
  19. Isomet 2114, Portable system for measurement of heat transfer properties of materials, Applied Precision Ltd. Stavitelska 1, 83104 Bratislava, Slovakia, (2015, September)