Soutenance de thèse – Yuliang ZOU “Modelling of the dynamic effects in capillary pressure in coupling with deformation on the desiccation of porous materials”

Yuliang ZOU soutiendra sa thèse le 10 décembre 2020 à 9h30 sur le sujet suivant :

“Modelling of the dynamic effects in capillary pressure in coupling with deformation on the desiccation of porous materials”

Résumé :

The durability of infrastructure made of porous materials such as soil, sand and cement-based materials is closely related to the environmental conditions. Most of the mechanisms of deterioration are governed by moisture state in porous materials. Indeed, the moisture state determines the distribution of capillary pressure which is an important driving force for solid deformation and could increase cracking risk. However, most of fluid-solid interaction models used to predict moisture transport and solid deformation have ignored the existing physical phenomenon dynamic effects on capillary pressure. This thesis aims to refine the fluid-solid interaction model with the consideration of this dynamic capillarity effect. Three dynamic models corresponding to various types of porous materials have been developed. The first model is available for porous materials with relative high permeability such as sand and soil. The second model is used for mature cement-based materials with low permeability. The third model is developed for hardening cement-based materials exposed to extremely low relative humidity condition. Each dynamic model and corresponding non-dynamic model have been implemented to simulate documented drying (drainage) experiments for sand, mature cement paste and hardening concrete, respectively. Compared with experimental data, the numerical simulations show that modeling with dynamic effects gives better results than non-dynamic modeling. All comparisons and investigations enhanced the necessity of considering dynamic capillarity effect to predict the moisture transport and solid deformation for fast drying (drainage) of porous materials.

Composition du jury

Rapporteurs :

Didier LASSEUX, Directeur de Recherche, CNRS, Université Bordeaux
Christelle MIQUEU, Maître de Conférences, Université de Pau et des Pays de L’Adour

Examinateurs :

Matthieu VANDAMME, Maître de Conférences, École des Ponts ParisTech
Gawtum NAMAH, Professeur, Université de Franche-Comté

Directeur et co-directeur de thèse :

Frédéric GRONDIN, Professeur, École Centrale de Nantes
Mazen SAAD, Professeur, École Centrale de Nantes