Why are cationic asphalt emulsions preferred for siliceous aggregates and damp surfaces?

Siliceous aggregates are often negatively charged and can be difficult to wet with anionic systems, especially when the surface is damp. Cationic emulsions carry a positive charge, improving electrostatic attraction and early adhesion to acidic, silica rich stone. They also tend to break more reliably in the presence of moisture, which helps in real jobsite conditions where perfect dryness is rare. The practical benefit is stronger initial bond and reduced risk of stripping or chip loss, provided application rate and break time are correctly matched.