What is the main purpose of applying tack in asphalt paving?

The main purpose of applying tack in asphalt paving is to bind the asphalt layers together. Tack coat is a thin layer of asphalt emulsion that is applied to provide adhesion between the existing pavement surface and the new asphalt layer being placed on top. This bonding is crucial for ensuring that the layers act as a single, cohesive unit once the paving process is completed. A strong bond minimizes the potential for delamination and improves the overall durability and longevity of the pavement structure.

Other choices may involve aspects related to asphalt paving but do not represent the primary purpose of tack. While increasing friction might have some relevance in specific contexts, it is not the primary goal of a tack coat. Reducing dust and debris can be a byproduct of proper tack coat application, but it is not its main function. Likewise, improving aesthetic appeal is not a primary concern of tack; rather, it focuses on structural integrity and performance.