The bulk density (ρap), linear shrinkage and water absorption
(EN 14411)15 were determined using cylindrical test pieces,
6 mm thick and 40 mm in diameter. The total porosity (εT),
open porosity, and closed porosity were calculated from the bulk
density, true density (Quantachrome, Helium Pycnometer UPY-
10T), and water absorption data. Polished cross-sections of the
samples were observed by SEM (Philips, XL-30 CP).