INFLUENCE OF TEMPERATURE, CEMENT AND PLASTICIZER TYPE ON THE RHEOLOGY OF PASTE

The effects of temperature on the rheological behaviour of cement pastes with three different types of plasticizers namely lignosulphonate, naphthalene sulphonate formaldehyde condensate and polyacrylate have been investigated. One type of cement was used in order to study the influence of hydration, while limestone was used as a non-reactive model system. The adsorbed amounts of plasticizers were measured for pastes of cement and limestone within a temperature range of 11 to 40 degrees C. The type of plasticizer was found to determine its affinity towards the limestone or cement surface at a given temperature. The plasticizer absorption seemed, moreover, to be governed by both kinetic energies and entropic effects of the organic molecules.