Which type of material is generally used to prime coat the base for surfacing?

The correct type of material used to prime coat the base for surfacing is asphalt emulsion. Asphalt emulsion serves as an effective bonding agent that penetrates the base material, ensuring that the surface is adequately prepared for additional layers of asphalt. It helps to seal the base, reducing the likelihood of moisture infiltration and the potential for damage due to freeze-thaw cycles.

Typically, the key qualities of asphalt emulsion that make it suitable for priming include its ability to create a strong adhesive bond, its compatibility with a range of base materials, and its effectiveness at enhancing the longevity and performance of the completed surface. It provides a solid foundation that improves the overall structure and durability of the asphalt layers applied on top of it.

While other materials like MC-70, water-based sealers, and polymer modifiers have their own applications in paving and surfacing, they are not primarily used as a primer for base coats in typical surfacing practices. MC-70, for instance, is a type of cutback asphalt, primarily used for seal coating and not as a base primer. Water-based sealers are generally used for surface protection rather than priming a base, and polymer modifiers enhance asphalt's performance but do not serve the specific role of priming.