Influence of calcium carbonate on the durability of mortar exposed to sea water solution

Normal Portland cement mortar discs containing precipitated or ground limestone at dosages of 0, 2.5, 5 and 15% were made at water/cement ratios of 0.42 or 0.6. They were hydrated in lime water or sea water solution for periods up to 1 year. The length and modulus of elasticity changes were monitored periodically. Mortars containing CaC03 (both coarse and fine) exhibited more than 3 times the expansion of the reference in sea water. The expansions were greater in samples containing fine CaC03. The modulus of elasticity was low especially in samples containing precipitated CaC03 and exposed to sea water.Des disques de mortier de ciment portland ordinaire contenant de la pierre \ue0 chaux moulue ou pr\ue9cipit\ue9e \ue0 dosages de 0, de 2,5, de 5 et de 15 % ont \ue9t\ue9 fabriqu\ue9s \ue0 des rapports eau de g\ue2chage/ciment de 0,42 ou de 0,6. Ils ont \ue9t\ue9 hydrat\ue9s dans une solution d?eau de chaux ou d?eau de mer pendant des p\ue9riodes allant jusqu?\ue0 1 an. Les changements de longueur et de module d?\ue9lasticit\ue9 ont fait l?objet d?une surveillance p\ue9riodique. Les mortiers contenant du CaC03 (tant grossier que fin) ont pr\ue9sent\ue9 plus de trois (3) fois la valeur de dilatation de l?\ue9chantillon-t\ue9moin dans l?eau de mer. Les valeurs de dilatation \ue9taient plus \ue9lev\ue9es dans les \ue9prouvettes contenant le CaC03 fin. Le module d?\ue9lasticit\ue9 \ue9tait particuli\ue8rement faible dans les \ue9prouvettes contenant le CaC03 pr\ue9cipit\ue9 et expos\ue9es \ue0 l?eau de mer.Peer reviewed: NoNRC publication: Ye