Dynamic pressurization method for measuring permeability and modulus: I. Theory

The permeability of a saturated porous body can be determined from the kinetics of dilatation resulting from a change in pressure in the surrounding bath. This method was previously applied to aerogels [Gross J, Scherer GW (2003) J Non-Cryst Solids 325, 34-47]. The theory is here extended to allow for the compressibility of the solid phase, so that the method can be applied to more rigid materials, such as concrete. A viscoelastic analysis indicates that creep of the sample will have a small effect on the measured permeability for cementitious materials, in most cases, However, the effect of entrapped air in the pore liquid is shown to have a drastic effect on the relaxation behavior, so it is essential to reduce the air content below ∼0.1 volume %. For samples without entrapped air, a simple result is obtained that is tested in a companion paper.