(561c) Wax Precipication Phase Behavior in Model Asphalt Systems

Precipitation of waxes in asphalt binder are related to many issues in asphalt pavements such as thermal cracking and rutting. Predicting the conditions for precipitation onset of waxes can help when comparing asphalt binders of different chemistries. To study this phenomenon, precipitation of wax in model asphalts was investigated. The chemical potentials of squalane as a model of pure wax and of squalane in multicomponent model asphalt systems have been compared over a range of temperature for different compositions. Whenever the chemical potential of pure wax goes below its chemical potential in the multicomponent system, the solid will precipitate.  The precipitation onsets of different composition were different which confirms that the chemistry of asphalt can determine its performance in real world applications.