What specifications must bitumen emulsion meet for compatibility with tarmac and asphalt layers?

Compatibility is defined by adhesion, breaking behavior, and residue performance at the interface. The emulsion should wet the existing asphalt, break within the desired time window for paving logistics, and leave a residue that bonds strongly without creating a slip plane. Key specs include viscosity for sprayability, binder content to achieve target application rate, sieve residue limits to prevent nozzle blockage, and residue properties such as penetration and softening point. Many projects also require bond strength tests or shear interface tests. Temperature, surface cleanliness, and moisture condition are as important as grade selection.