ABSTRACT
Abstract The sifting o f a concrete gives some indications about the cement paste bonding with aggregates. Results o f this sifting test lead to the formulation of a method to carry out concrete composition. The use o f a plastometer test accompanied with a suitable data processing method gives a global identification of the rheological behaviours o f fresh mixes. According to the beginning of this study, some specific mortars with or without additives are tested with a plastometer. These tests show the apparition o f a cement paste migration through a coated aggregates matrix. The proposed method o f formu lation gives mortars presenting essentially a plastic behaviour with a Coulomb’s crite rion. More supple mortars present a viscoplastic behaviour. But evolution of the plastic yield is subordinated to the possible consolidation of the material. Keywords: behaviours o f fresh mortars and concretes, composition method, additives, plastometer, plasticity, consolidation.
