Changes in weight and dimensions in the drying and carbonation of Portland cement mortars

Small specimens of mortar and paste were cured for 28 days and then subjected to various conditions of drying and carbonation. In general the extent of carbonation, for a given CO[2] concentration, depends upon permeability, moisture content and time, but the extent of carbonation shrinkage and ultimate volume stability depend on the compressibility of the aggregate, the water/cement ratio, the maturity of the paste, the drying environment and rate, and on the sequence of drying and carbonation. Some of the practical implications of these results are noted.De petits sp\ue9cimens de mortier et de p\ue2te (trait\ue9s durant 28 jours) de perm\ue9abilit\ue9 et de compressibilit\ue9 vari\ue9es ont \ue9t\ue9 s\ue9ch\ue9s avec carbonatation subs\ue9quente ou simultan\ue9e, \ue0 diff\ue9 rents degr\ue9s d'humidit\ue9 relative allant de 100 \ue0 0%. En g\ue9n\ue9 ral, les r\ue9sultats de la carbonatation, pour une concentration donn\ue9e de CO[2], d\ue9pendent de la perm\ue9abilit\ue9, de la teneur en humidit\ue9 et du temps, mais l'importance du retrait d\ufb \ue0 la carbonatation et la constance finale du volume d\ue9pendent de la compressibilit\ue9 des agr\ue9gats, du rapport eau-ciment, de la maturit\ue9 de la p\ue2te, du milieu ambiant et de la vitesse du s\ue9chage, et des s\ue9quences de s\ue9 chage et de carbonatation. L'auteur note quelques implications pratiques de ces r\ue9sultats.Peer reviewed: NoNRC publication: Ye