How does aggregate type influence the required properties of tack coat bitumen emulsion during application?

Aggregate mineralogy directly affects breaking behavior and adhesion. Siliceous aggregates typically require cationic emulsions with higher surface activity, while calcareous aggregates may tolerate a broader range. Dusty or moist aggregates delay breaking and require emulsions with faster setting characteristics. Aggregate temperature and absorption also matter. Proper emulsion selection ensures rapid break, uniform film formation, and strong bond between asphalt layers.