PERFORMANCES OF THE MORTARS DIFFERENT CONTAINERS ADDITIONS

The cementing matrices made with a mineral addition were the subject of many studies. However no general rule was still released to quantify the effects of such additions, with respect to the performances of the mortars, because the mixture of various materials is not a simple operation, because of the incompatibilities which can exist between various components. In addition, the mixture of compatible materials always does not lead to the same results; interactions (or interactivities) possible can exist between the various types of materials. These interactions can appear by synergisms or antagonisms between the components, and are difficult to detect. Thus, few studies were carried out to highlight the possible interactions between the various components of the cementing mixtures. The researchers recognize the need for complex and powerful tools to undertake studies in this field. The purpose of this article is to study additions mineral, chemically inert or pozzolanic, on the performances in state fresh and hardened mortars. The parameters of the study are the nature and the content of the mineral addition. The rate of substitution of cement by the addition is 10 and 20% in mass. The influence of the nature and the quantity of addition is examined, by choosing additions whose smoothness is of the same order than cement. The experiments mainly on mortars made it possible to establish: The type of cement is a parameter of very first importance. It is not easy of given the characteristics of cement (smoothness, content of C3A. . .) who have an influence on the couple addition-superplastifiant. Superplastifiant entraine a strong increase in resistances in all term. Its effect is marked less for the mortars with fly-ashes. The choice is thus not only a one function of the nature of the addition but a characterization of association (cement-additions-superplastifiant). This study brings a lighting on the adequacy of the various components and should help in the long term, with the installation of rules of formulation of adjuvantés cementing materials.

Keywords:

Cementing matrices , Additions , Superplastifiant , Performances