On the significance of electroosmosis in hardened cement paste

The observation of an electrochemical effect of hardened cement paste has recently been described in the literature. Further experiments underline the fact that electroosmosis is the origin of this effect. Water movement under the action of an electric field causes partial swelling and shrinkage. A bending moment is created in a similar way as in a bimetal strip. The electromechanical effect has been studied as a function of water/cement ratio, of age of specimen and of moisture content. Results are discussed on the basis of a tentative and simplified explanation.