2. Experimental
2.1. Materials
The investigation was performed with an industrial spray-dried
powder normally used for the production of porcelain stoneware
tiles.
The sawdust was supplied by a Portuguese sawmill company
“Campos & Filhos S.A.”, in Paredes (Portugal) and comes from
wastes of wood from Fagus sylvatica and Quercus faginea.
2.2. Sample preparation
Bi-layered ceramic discs, with 25 mm diameter and 8 mm
thickness, were produced by following a procedure described