BOND/TACK COATS AND PRIMERS
A bond coat is very inexpensive insurance to ensure structural integrity between asphalt layers.
In order to improve the bond between layers of pavement a bond coat should be applied. A bond coat is very inexpensive insurance to make sure there is structural integrity between the pavement layers. There are many different types of emulsions used in bond coating.
Features and Benefits
- Prevents de-bonding of the HMA layers
- Prevents mat slippage and reduces top-down cracking
- Enables superimposed lifts to act as a monolithic layer, thus increasing the overall structural capacity of the roadway
- Increased pavement life and decreased life cycle cost
- Small cost versus the benefit
A bond coat is a spray application of asphalt emulsion, applied to an existing asphalt or portland cement concrete surface prior to a new asphalt overlay or patching to eliminate slippage planes and provide a better bond between new and existing pavement layers.
Primers penetrate quickly into the granular surface and bind the material together, to partially waterproof the granular surface to prevent water erosion, to provide a temporary riding surface prior to overlay or seal coating and to provide a bond between the existing surface and the new wearing surface.