Tack Coat

Definition

A tack coat is an application of a material made from asphalt applied to an existing surface to ensure its bond to new construction layers.

Purpose

The tack coat is used to create a strong adhesive bond between an old asphalt surface and a new asphalt layer. This process is crucial in road construction and maintenance to prevent slippage and ensure the structural integrity of the pavement.

Examples of Use

1. Road Resurfacing: Tack coats are applied before laying new asphalt over existing roads to create a durable bond between the layers.
2. Paving Projects: In large parking lots and driveways, a tack coat ensures that the new asphalt adheres properly to the old surface, preventing premature cracking and wear.

Related Terms

• Prime Coat: An asphalt coating applied to a prepared base before the main paving layer, improving adhesion and waterproofing.
• Overlay: A new layer of asphalt applied over an existing pavement surface to restore its smoothness and extend its lifespan.
• Seal Coat: A protective coating applied to asphalt pavements to extend their life and improve appearance.

Notes

• Application Method: The tack coat should be applied uniformly and allowed to become tacky before the new asphalt layer is laid.
• Material Choices: Different types of asphalt emulsions can be used for tack coats, each suited for specific conditions and requirements.