Tack Coats are used as which application?

• A. Surface treatment
• B. Prime coat, dust control
• C. Paving asphalt
• D. Dust control only

Answer: (B)

Tack coats provide a thin bonding layer between pavement lifts to promote adhesion and also help control surface dust. The tack coat is an emulsion that’s sprayed lightly so it stays tacky, allowing the new asphalt layer placed on top to bond effectively with the existing surface. This bonding is crucial to prevent slippage and debonding at joints as traffic loads and temperature change. At the same time, the tack coat helps seal the surface and reduce dust and fines loss before the next lift is applied. It isn’t simply a surface treatment or the paving asphalt itself, and it isn’t limited to dust control only, which is why it’s described as a prime coat, dust control.