Thermal and mechanical properties of a foamed glass-ceramic material produced from silicate wastes

Lightweight glass-ceramic foams produced from silicate wastes have been characterised with regards to their thermal and mechanical properties. The level of porosity of the fabricated foams was controlled by varying the heat treatment temperature and the amount of foaming agent. Lee's Disc was used to measure the thermal conductivity of each type of foam in order to assess its potential as a thermal insulator. The most porous material, with a porosity of 90%, achieved a thermal conductivity of about 0.2 Wm^-1 K ^-1. Good agreement was obtained between experimental conductivity data and simulated values obtained by a finite element analysis, which employed structural information obtained from x-ray microtomography. Mechanical properties, such as Young's modulus, flexural and crushing strength of foams of various densities, were also determined in this study. Correlations against well known models indicated the waste derived foams behaved in a manner typical of brittle foams. The study provides an understanding of the thermal and mechanical behaviour of glass-ceramic foams; these waste derived materials show potential for thermal insulation applications.