A mathematical model relating the flow curve of a cement paste to its water/cement ratio

Abstract

Synopsis This paper describes an experimental and empirical study of the rheological properties of cement pastes under the action of a steady shear. Experimental results were obtained by using a Weissenberg rheogoniometer for a range of water/cement ratios of ‘fresh’ pastes. Particular reference is made to a mixing method which produces reversible flow curves. Various models are considered as empirical relationships between shear stress and shear rate. It is shown that the Robertson Stiff model provides a very accurate description of the rheology of the cement paste for a range of concentrations. An indication is given of the possibility of predicting flow curves by the use of a proposed empirical equation. Qualitative agreement is obtained between theory and experiment.