Dispersion forces in cement suspensions

Dispersion forces, often also referred to as van der Waals forces, are the main cause for agglomeration of cement particles in concrete and of the poor resulting flow properties. To counter these forces and improve flow, dispersants are added. The balance of attractive and repulsive forces between cement particles has a profound impact on the flow of concrete. This paper only addresses the attractive force which requires an evaluation of the Hamaker constant of cement phases. It presents an approximation that allows to estimate the magnitude of this force despite the lacking experimental data on the dielectric properties of cement phases. (C) 2004 Elsevier Ltd. All rights reserved.