This paper presents a contribution to the modeling of the chemical shrinkage of the slag-blended cement paste (binder) at early age. Assuming that the chemical shrinkage is a direct result of hydration, the hydration modeling of slag-blended cement was studied by considering the interaction between the hydrations of blast furnace slag (BFS) and ordinary Portland cement. The reaction of BFS in the presence of calcium hydroxide CH (Portlandite) produced from the hydration of the cement was investigated. The kinetic hydration of cement was developed, and the volume phases in the cementitious material during the hydration process were calculated. The chemical shrinkage, which is the negative volume balance between the reactants and the products formed, is then calculated. In parallel with this numerical modeling, an experimental study was conducted to investigate the effect of slag's addition (0%, 30%, 50% and 80%) on the heat of hydration and chemical shrinkage at early age (maturation up to 7 days). The proposed hydration model incorporates the effect of following variables; the chemical composition of the binder, the fineness, the water to binder ratio (w/b), the curing time and the temperature.

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Abstract. The main objective of this study is to detect the influence of the addition of limestone fillers in moderate percentages (0%, 10% and 20%) on the performance of binder formulations containing different dosages of blast furnace slag (ranging from 20% to 80%). The analysis parameters are mercury intrusion porosity and mechanical properties. The tests were performed on 12 blended pastes made with a water/cement ratio equal to 0.32. The mechanical properties of different pastes were investigated at several curing time (1 day, 7 days, 28 days and 90 days). The obtained results allowed estimating the possibility to benefit from the complementarity and synergy of the three components considered in the mechanical performance (compressive strength and dynamic Young's modulus) of ternary binders studied at both early age and mature age.Résumé. Le principal objectif de cette étude est de déceler l'influence de l'addition de fillers calcaires en pourcentages modérés (0%, 10% et 20%) sur les performances de formulations de liants contenant différents dosages en laitier de haut fourneau (variant de 20% à 80%), en considérant, comme paramètres d'analyse, la porosité accessible au mercure et les propriétés mécaniques. Les essais ont été réalisés sur 12 pâtes de liants composées avec un rapport Eau/Liant égal à 0,32. Les propriétés mécaniques des différentes pâtes ont été étudiées à plusieurs échéances (1 jour, 7 jours, 28 jours et 90 jours). Les résultats obtenus nous ont permis d'estimer la possibilité de bénéficier de la complémentarité et de la synergie des trois composants considérés sur les performances mécaniques (résistance à la compression et module d'Young dynamique) des liants ternaires étudiés au jeune âge et à âge mature.