What is the primary purpose of a tack coat in asphalt paving?

The primary purpose of a tack coat in asphalt paving is to provide a bond between surface layers. A tack coat is a thin layer of asphalt emulsion applied between two layers of asphalt to ensure proper adhesion and bonding. This bond is critical for the structural integrity and longevity of the pavement, as it helps to transfer loads between the layers effectively. Without a proper tack coat, there is a risk of delamination or separation of the layers, which can lead to premature failure of the road surface.

While improving aesthetics, preventing water infiltration, and enhancing skid resistance are important aspects of asphalt paving and contribute to the overall performance and safety of the pavement, they are not the primary function of the tack coat. Its main role is indeed focused on ensuring a solid and durable connection between different asphalt layers.