Study of the Scatter Between Gas and Liquid Permeability of a Mortar

In this study we present the results of numerous tests carried out on several samples cored from the same mortar. Permeability is measured on a sample, dried prior to the test, by injecting flow. Two gas and liquid permeability cells, using special devices for measuring the injected flow under steady conditions, were designed and presented in this paper as well as the technique of interpretation. In this work, we chose respectively argon (a neutral gas), ethanol and water to investigate gas and liquid permeability. Preliminary tests showed that the water permeability was systematically lower (in an order of magnitude from 1 to 2) than gas permeability whereas ethanol permeability was intermediate between these two values. Nevertheless ethanol and gas permeabilities were found of the same order. Further tests were then carried out and gas permeability was corrected from the Klinkenberg (or slippage) effect. In this case, permeability results obtained with argon and ethanol were identical and can be considered to be the intrinsic permeability value. Thus, the differences observed between water and gas permeability values have to be explained by other phenomena such as re-hydration and dissolution.