Evaluation of thermodynamic properties of concrete substrates and cement slurries modified with admixtures

The study of the creation and the stability of the interface between concrete substrates and repair systems needs the knowledge of the thermodynamic properties of materials. The measurement of the surface free energies of liquids is realised by means of Wilhelmy plate method on reference liquid and repair products. In order to determine polar and dispersive components, it is necessary to measure the contact angle of these liquids and products on reference solid surfaces and on concrete, mortars and aggregates. Centrifuged solutions of repair product systems elements were prepared in order to measure surface free energies on pure liquids without solid particles in suspension. Evolution of properties versus time were also taken into account and analysed in comparison with well-known liquids and products.