ABSTRACT
Abstract A coaxial cylinder viscometer was used to evaluate the dispersing effect of several admixtures in cement pastes with low w/c ratio (0.3). The results indicated that naph thalene based plasticizers had a different dispersing effect depending on their origin, melamine admixtures were not suitable under these special conditions and specially re fined lignosulphates could be added to naphthalene based admixtures on a substitute basis and an additional plasticizing effect obtained. Keywords: admixtures, cement paste, plasticizers, rheology, viscosity, yield stress.
