Environmental Engineering Reference
In-Depth Information
- During imbibition, air can be trapped inside the porous structure.
- Drainage of a given pore requires that a continuous path exists between this
pore and the outer surface, etc.
Of course, under real conditions with varying external stresses due to the local
climate, water transfers inside stone can shift between imbibition and drainage
and/or between sorption and desorption; and the corresponding (
h
, θ) points can be
situated anywhere between the two limit retention curves.
10
5
10
4
1000
Rouffach
Rorschach
100
10
0
0.2
0.4
0.6
0.8
1
Water saturation rate S
Figure 9.4.
Example of retention curves obtained by drainage
in a pressure chamber. Rouffach and Rorschach sandstones [LAU 93]
10
Tuf1 adsorption
Tuf1 desorption
Tuf2 adsorption
Tuf2 desorption
GAB model - adsorption
GAB model - desorption
8
6
4
2
0
0
20
40
60
80
100
Air relative humidity (%)
Figure 9.5.
Sorption isotherm example obtained on saline solutions.
“Tuffeau” samples [CHE 99]
