Which of the following materials is NOT considered a tack coat material?

Tack coat materials are typically used as bonding agents between layers of asphalt or between asphalt and other materials to ensure good adhesion. Asphalt emulsion, such as grades RS-1H and others, are common tack coat materials because they are designed specifically to enhance the bond between surfaces.

Concrete binder, however, is not categorized as a tack coat material. Concrete binders are used in the context of concrete applications, serving a different purpose altogether in the pavement structure and maintenance. They do not function as a bonding agent between asphalt layers, which makes them unsuitable for use as a tack coat.

The other materials listed—Asphalt Emulsion and Grade RS-1H—are explicitly designed for use in tack coatings, contributing to the adhesion process essential in asphalt pavement construction and maintenance.