It is the first application of low viscosity liquid bituminous material over an existing porous surface like WBM base course. The main object of priming is to plug in the capillary voids of the porous surface using a low viscosity binding material. Mainly SC or MC cutbacks are the suitable grades chosen on the porosity of surface.
The application of bituminous material over an existing impervious pavement surface which has already been treated by a prime coat. Tack coat is generally of higher viscosity at the rate of kg/10m2 depends on type of surface.
Seal coat is mainly applied on impervious surface of bituminous pavements as a top coat. A pre mixed sand bitumen (hot mix) seal coat is commonly used over the premixed carpet. The main function of seal coat is to seal against the ingress of water and to develop skid resistance texture.