How does emulsion chemistry influence the suitability of bitumen emulsions for different uses?

Emulsion chemistry controls droplet charge, breaking mechanism, and interaction with aggregate and substrate. Cationic emulsions bond well to acidic siliceous aggregates and typically break faster, making them common for tack coats and surface dressing. Anionic emulsions can suit basic limestone aggregates and some coating systems where slower breaking is acceptable. Surfactant type, pH, electrolyte level, and stabilizers determine storage stability and sensitivity to contamination. Polymer or latex modification improves cohesion, elasticity, and stripping resistance, which is valuable for high stress surfacing, waterproofing, and crack bridging systems.