Published online by Cambridge University Press: 22 February 2011
While there is presently a great deal of interest in measurement of permeability, there are a wide variety of non-standard methods reported. The author's experience combined with a critical review of the literature is that:
(a) results vary with operating variables of each test,
(b) the coefficient of variation of results is large (typically 30 to 50%),
(c) most methods cannot provide quantitative results in the range of interest for high strength, concretes and those containing supplementary cementing materials (10−15 m/s or less),
(d) most methods do not represent the type of boundary conditions experienced by most critical concrete field conditions (i.e. fluid on one side and vapour on the other side),
(e) Indirect measures of permeability such as rates of absorption, or resistivity measurements are easier to perform and relate directly to permeability.
The activity of research in the area of permeability is similar to that described in the technical literature from the 1920's and 1930's. Much of that early work has abandoned for reason (c) above.
It is attempted to review some of the previous experience, describe the problems and make suggestions for improved measurement of permeability.