Total porosity was determined through the following steps: (1) determination of
the dry mass and saturated surface-dried mass of the specimen (weighed in water
and air); (2) calculation of density and apparent density from parameters from the
previous step; and (3) calculation of solid material volume with a basic formula
for density and isolated pore volume with a basic formula for apparent density, using
the assumption that the total volume of the specimen was a sum of solid material
volume, isolated pore volume, and connected pore volume. In addition to this calculation,
porosity was determined by Avizo Fire 3D image analysis software, which is
based on two-dimensional X-ray images (threshold segmentation method and characterization
of different pore spaces have been written about by Korat et al. [12] and
Henry et al.