Effect of the Setting Agent (Lime) on the Physico-Chemical Properties of Slag Cement and Mechanical Behavior of Mortar

The increase of the pozzolanic admixture (slag) added as a replacement for cement causes a disadvantage of a longer initial setting time and a slower strength development in cold time. The aim of the present experimental work is to evaluate the influence of mineral activator (hydrated lime) of slag cement (latent hydraulicity) on the physico-chemical properties of slag cement (C.E.M II) and the mechanical behavior (Flexural and compressive strengths) for the mortar. The activation method by hydrated lime of slag cement activates the hydration process, influenced the size of particles and leads to the formation of ettringite and CSH (tobermorite) at the early ages of hydration. In this experimental study, the setting agent Ca(OH)2 used for activation slag cement is used in the proportions of 0%, 2%, 4%, 6%, 8% and 10% by various methods (substitution and addition by mass of slag cement). The physical properties of cements (C.E.M II) activated by the calcium hydroxide at anhydrous state and the state hydrated (specific weight, fineness, consistency of the cement pastes and setting times) thus the characteristics of the mortars made at their bases, such as, the mechanical behavior (Flexural and compressive strengths for the mortar) after 7, 28 and 90 days were studied.