Implementation of a layer of Bitumen Emulsion on the base. It prepares the base for performing another asphalt layer on it. Cationic Slow Set (CSS) or Rapid Set (CRS) type of Bitumen Emulsion is used for this kind of application.
1- It penetrates to the base layer and coats materials and aggregates on the base. It acts like a glue between the materials of the base and binds them to each other.
2- It makes the base layer hard and tough. Only 1 to 1.2 kg of Bitumen Emulsion is enough to be applied per each square meter whereas Cutbacks must be paved 1.2 to 1.8 kg per square meter.
3- It also makes the base layer water proof and acts as a sealant by filling the voids and cavities.
4- It sticks base layer to asphalt layer implemented on it.
5- If the road has water holes or the surface is water saturated, prime coat must not be applied until water is removed.
6- It is highly suggested to pave a water layer on the base surface for better penetration of prime coat esp. when the surface is dusty (The case often neglected by the contractors).
7- If the base density is more than 96%, it is highly recommended to remove the dust off the base and spray water onto the surface, before prime coat.
8- After 4 to 15 hours, the first asphalt layer can be applied which is a short time compared to Cutbacks.
9- It is worth saying the application has low cost.