Viscosity prediction of fresh cement asphalt emulsion pastes

Cement asphalt emulsion (CA) composite materials are becoming promising building materials in recent years. Assessing their rheological behavior is crucial for the success of a particular application. Fresh CA pastes with different asphalt emulsion to cement mass ratios (AE/C) have significantly different compositions, and design of their rheological properties is not an easy task. The minimum apparent viscosity of CA pastes with different AE/C is predicted by a viscosity prediction model. The model parameters include maximum particle packing density (ϕm) and an adjusting factor b. A predictive model of CA composite particles is proposed, in which the maximum particle packing density of CA pastes can be determined by the maximum particle packing density of cement paste, the maximum particle packing density of asphalt emulsion, and the volume fraction of asphalt in asphalt-cement system. The predictive model requires different adjusting factor b for CA pastes with anionic and cationic asphalt emulsion when the predicted ϕm is used for viscosity prediction. The proposed viscosity prediction equations do offer a simple and reliable method for the viscosity prediction of CA pastes with a wide AE/C range, and can be used to design the rheological properties of CA pastes.