TACK COAT AND PRIME COAT AS PER SAUDI ARAMCO STANDARD SAES Q - 006 & AASHTO

What is the Prime Coat and where is it applied ?

Ans. - Prime coat is the asphalt bituminous material that is placed on the substrate prior to placement of the first asphalt mixture (the binder course). It must be allowed to cure and to soak into the capping laying (usually select fill)

What is its curing requirement for the Prime Coat?

Ans. 24 hours. A good indication that the material is cured is when the color tunes to pitch-black.

What is Tack Coat?

Ans. It is the asphalt bituminous material that is applied on existing concrete or asphalt surfaces to bond the new subsequent pavement to them, Tack coat is not necessary to place on new asphalt before placing the next layer of asphalt unless it is soiled (dirty).