Drying induced moisture losses from mortar to the environment. part II: numerical implementation

This paper presents a novel methodology to appropriately account for boundary conditions in numerical analyses of moisture fields in cementitious materials. The proposed methodology consists of using experimentally obtained moisture emissivity coefficients together with the vapour pressure difference between the environment and the exposed surface (based on the average surface humidity content). The performance of such methodology (implemented on DuCOM, a computational code suitable for calculation of moisture/temperature fields in cementitious materials) is evaluated by comparing the numerical predictions with the experimental results presented in the Part I companion paper. Influences of the many environmental conditions reported in Part I are investigated for validation of the proposed numerical methodology: temperature, relative humidity, wind speed and age of exposure of specimens. Furthermore, an additional numerical formulation for inclusion of the effect of evaporative cooling, based on the computation of additional heat fluxes induced by evaporative moisture losses, is presented, together with a validation example. Finally, two numerical sensitivity analyses are put forward for clarification of the relative importance of the parameters involved in moisture loss from cementitious materials, as well as the relevance of the evaporative cooling.