"Microstructure (physique)" . "Text" . "La composition d\u2019un mat\u00E9riau cimentaire influe sur la formation de sa microstructure et par cons\u00E9quent sur ses propri\u00E9t\u00E9s de transfert d\u00E9terminant sa durabilit\u00E9. Celle-ci peut \u00EAtre caract\u00E9ris\u00E9e \u00E0 l\u2019aide d\u2019indicateurs de durabilit\u00E9. Dans la litt\u00E9rature, il existe tr\u00E8s peu de mod\u00E8les permettant l\u2019estimation de ces indicateurs \u00E0 partir de la composition d\u2019un mat\u00E9riau cimentaire. Dans ce travail de th\u00E8se, nous nous int\u00E9ressons \u00E0 un indicateur de durabilit\u00E9 particulier : la perm\u00E9abilit\u00E9 au gaz. Notre objectif consiste \u00E0 \u00E9tudier le lien entre la composition d\u2019un mat\u00E9riau cimentaire et sa perm\u00E9abilit\u00E9. Dans un premier temps, cette relation est \u00E9tudi\u00E9e et analys\u00E9e \u00E0 travers une \u00E9tude exp\u00E9rimentale sur des p\u00E2tes de ciment, mortiers et b\u00E9tons. Le but est de d\u00E9terminer l\u2019influence des param\u00E8tres de formulation sur la microstructure et sur la perm\u00E9abilit\u00E9 d\u2019un mat\u00E9riau cimentaire. Ensuite, une \u00E9tude de mod\u00E8les donnant la perm\u00E9abilit\u00E9 d\u2019un mat\u00E9riau cimentaire \u00E0 partir des caract\u00E9ristiques de sa microstructure est faite. Pour finir, un mod\u00E8le permettant de pr\u00E9dire la perm\u00E9abilit\u00E9 d\u2019une p\u00E2te de ciment \u00E0 partir de ses param\u00E8tres de formulation (E/C, surface sp\u00E9cifique Blaine et densit\u00E9 du ciment) est propos\u00E9 et compar\u00E9 aux mod\u00E8les pr\u00E9c\u00E9dents et aux perm\u00E9abilit\u00E9s exp\u00E9rimentales." . "Th\u00E8ses et \u00E9crits acad\u00E9miques" . "Vers une pr\u00E9diction de la perm\u00E9abilit\u00E9 au gaz \u00E0 partir de la composition des mat\u00E9riaux cimentaires" . . . . "Vers une pr\u00E9diction de la perm\u00E9abilit\u00E9 au gaz \u00E0 partir de la composition des mat\u00E9riaux cimentaires" . "Mat\u00E9riaux -- D\u00E9t\u00E9rioration" . . . . "Towards a prediction of gas permeability form cement-based materials composition" . . "Mod\u00E8les math\u00E9matiques" . . . . . . . . "2009" . "Ciment -- Composition chimique -- Perm\u00E9abilit\u00E9" . "Cement-based materials composition affects its microstructure and consequently its transfer properties governing its durability. This later may be characterized using durability indicators. The literature gives practically no models which link these indicators to the composition of a cement-based material. In this work, we focussed on the gas permeability as a durability indicator. Our objective is the study of the relationship between the permeability of a cement-based material and its composition. Firstly, this relationship is studied and analysed by means of an experimental study on different kinds of cementitious materials: cement pastes, mortars and concrete. The aim is to characterize the influence of the composition parameters on the microstructure and on the gas permeability. Then, models giving cement-based materials permeability from their microstructural characteristics were studied. Finally, a model allowing the prediction of the permeability of a cement paste from its composition parameters (W/C, cement Blaine specific surface and cement density) was proposed and compared to the previous models and to the experimental permeability." . .