The effective elastic properties and thermal conductivity of porous fired clay bricks

Abstract

Due to the environmental protection requirement, fired clay bricks are not only satisfied with mechanical strength but also rising energy utilisation. Based on the analysis of microstructure, it can be found that fired clay bricks are porous composite materials. The research objective of this article is to study the effect of micropores in order to provide a reference to achieve a compromise between mechanical and thermal properties. Firstly, a simplified representative volume element containing solid matrix and pores is presented at a microscale. Next, the homogenisation technology is introduced to build a micro–macro relationship. In this paper, Ponte Castañeda–Willis scheme considering the spatial distribution of micropores is used to predict the effective elastic properties and effective thermal conductivity of fired clay bricks. The results are compared with those by Mori–Tanaka scheme. Walpole’s notation is introduced to describe the transversely isotropic elastic tensors. Then, parameter calibration and experimental validation are implemented. Lastly, several conclusions and perspectives are given. Based on our results, porosity, the aspect ratio and the spatial distribution of micropores can affect the elastic and thermal properties, so we can control the macroscopic properties by changing the three factors.

Keywords:

• Elastic properties
• fired clay bricks
• homogenisation
• porosity
• thermal conductivity
• transverse isotropy

Acknowledgements

The author Zeye TIAN thanks China Scholarship Council for supporting this research.

Disclosure statement

No potential conflict of interest was reported by the authors.