Demulsification process of asphalt emulsion in fresh cement-asphalt emulsion paste

摘要

The demulsification process of asphalt emulsion in fresh cement asphalt emulsion (CA) paste was investigated by measuring the viscosity and the particle size distribution of CA paste. The morphology evolution of asphalt droplets was also observed by optical microscope. Superplasticizer was used to adjust different demulsifying speed of asphalt emulsion in CA paste. Results indicate that the viscosity development of CA paste can reflect the demulsification process of asphalt emulsion in CA paste. The demulsification process of asphalt emulsion in CA paste has two main stages under the continual induction effect of cement hydration. Asphalt droplets in CA paste are firstly coalesced to big droplets, and then recover their adhesive force. In the first stage, the viscosity of CA paste increases little with the changing particle size distribution. However, the viscosity of CA paste increases sharply in the second stage.