ON THE USE OF A MIGRATION TECHNIQUE TO MEASURE THE DIFFUSION COEFFICIENT OF CEMENT-BASED MATERIALS

Author(s): Thomas Wattez, Anne Duhart-Barone and Sylvie Lorente
Paper category: Proceedings
Book title: Proceedings of CONSEC13 Seventh International Conference on Concrete under Severe Conditions - Environment and Loading Volume I
Editor(s): Z.J. Li, W. Sun, C.W. Miao, K.Sakai, O.E. Gjørv, N.Banthia
ISBN: 978-2-35158-124-7
e-ISBN: 978-2-35158-134-6
Publisher: RILEM Publications SARL
Publication year: 2013
Pages: 541-552
Total Pages: 961
Language : English

Abstract: This work focuses on the development of an alternative method to determine the effective diffusion coefficient of water through saturated cement-based materials. In comparison to the standardized method, based on natural diffusion of tritiated water, the electrokinetics technique developed here rests on the application of a constant voltage through the material, and the measurement of the resulting electrical current. The diffusion coefficient is calculated with the Nernst-Planck and the Nernst-Einstein equations. The main advantage of such a method is to reduce considerably the test duration, from years to days. Two kinds of materials are tested: one concrete based on Portland cement and one concrete based on blended cement. A comparison is performed with an electrochemical impedance spectroscopy method (EIS). The results indicate that the effective diffusion coefficient does not vary significantly neither with the technique used for its determination, nor with the ionic strength of the saturation solution, as expected when using a carefully controlled metrology.

Online publication : 2013
Publication type : full_text
Public price (Euros) : 0.00