TC 116-PCD: Permeability of concrete as a criterion of its durability

In the experimental research project, standard test methods are developed for the measurement of transport coefficients of concrete for gases, water and chloride ions. Since the moisture concentration in concrete is a most important parameter in affecting the transport parameters, in the first work package of the project a preconditioning method was developed to install a controlled water content with a homogeneous distribution in the test specimens. The effectiveness of preconditioning was evaluated in an initial intercomparison testing. Subsequently, a selection of frequently used test methods for laboratory and on-site testing of the gas permeability, the absorption of water and the penetration of chloride ions were applied to a range of concrete grades. This enabled evaluating the suitability and range of applicability of the methods, proposing improvements and correlating the measured transport parameters with durability characteristics. The Cembureau set-up was then selected as a standard method for gas permeability measurements; for the capillary absorption of water, a modified ponding test was recommended. For the measurement of chloride ion ingress, a migration test and an immersion test were evaluated; these tests had been used in the past for pre-testing of concrete mixes and in production control during the erection of advanced structures. However, both methods have not yet been recommended as routine tests in quality control. In a final intercomparison testing, the selected methods showed good agreement among the participating laboratories. Test instructions, which may serve as drafts for European standards on test methods for concrete, are proposed for the preconditioning of test specimens, for the measurement of gas permeability and for the determination of the capillary absorption of water on separately cast companion specimens