Influence de l'Argile Bentonite sur le temps de prise et le retrait de la pâte cimentaire modifiée avec un adjuvant superplastifiant.

Abstract

Mineral additions are increasingly used by concrete and mortar producers. Their consideration in the formulation of cementitious materials for compliance with the minimum cement dosage (substitution of a quantity of cement by mineral addition) is of particular interest on the economic (reduction in the cost of raw materials) and ecological (reduction CO2 emissions and consumption of non-renewable resources). This study aims to valorize a Bentonite clay from the Maghnia region in the form of calcined powder (heat treated) in a mortar in the fresh and hardened state, where the major interest of which is given to the mechanical and physical properties of the material. So, the influence of different Bentonite dosages (5, 10, 15 and 20%) was studied experimentally in an adjuvanted mortar with a E/L ratio equal to 0.28. The main objectives of this work are to study the influence of Bentonite on the evolution of capillary absorption and occluded air, as well as on the evolution of the setting time and the shrinkage of the material in its hardened state. In this study, mathematical relationships are developed between certain physical and mechanical properties determined in the fresh and hardened states.