Condensation and isothermal water transfer in cement mortar: Part II - transient condensation of water vapor

✍ Scribed by Jean-François Daian

• Book ID: 104635620
• Publisher: Springer Netherlands
• Year: 1989
• Tongue: English
• Weight: 778 KB
• Volume: 4
• Category: Article
• ISSN: 0169-3913
• DOI: 10.1007/bf00134739

✦ Synopsis

The transient wetting of a mortar sample swept by a flow of humid air is experimentally studied at temperatures of 30 and 55~ The water content profile shape and evolution are found to be very different from those which were observed during imbibition. The boundary condition on the exposed wall of the sample is examined. A convenient evolution of the coefficient of diffusion with water content is explored. This coefficient is interpreted in terms of pure vapor diffusion, even at relatively high water contents. But its values at low water content and its temperature dependence are inconsistent. Additional explanations are then considered with the assumption that the vapor condensation in the medium is not an equilibrium process between vapor and liquid phases. The physical origin of such a nonequilibrium process is discussed. A tentative set of transfer and phase change coefficients is proposed in order to describe the experimental data by means of numerical simulation. Then, some aspects of the imbibition processes are re-examined, taking into account the consequences of a nonequilibrium condensation.