Prime Coat of road
A bituminous prime coat is the first application of a low viscosity liquid bituminous material over an existing porous or absorbent pavement surface like the WBM base course. The main object of priming is to plug in the porous surface's capillary voids and bond the loose mineral particles on the exiting surface, using a binder of low viscosity that can penetrate into the voids. Usually, MC or SC cutbacks of suitable grade are chosen depending on the porosity of the surface to be treated. The bituminous primer is sprayed uniformly using a mechanical sprayer at a rate of 7.3 to 14.6 kg per 10 m2 area. The primed surface is allowed to cure for at least 24 hours, during which period no traffic is allowed.
The objective of priming the granular surface is to:
1) Penetrate deep into the surface and plug or seal the voids on the surface.
2) Coat and bond the loose particles on the surface.
3) Render the surface of the base course water-resistant and
4) Permit the tack coat to be applied over the primed surface to provide proper adhesion between the base and the bituminous pavement layer constructed above the treated granular base.
Objective:
The objective of priming the granular surface is to:
1) Penetrate deep into the surface and plug or seal the voids on the surface.
2) Coat and bond the loose particles on the surface.
3) Render the surface of the base course water-resistant and
4) Permit the tack coat to be applied over the primed surface to provide proper adhesion between the base and the bituminous pavement layer constructed above the treated granular base.
No comments
Thank You For Your Comment.