What does the term 'asphalt emulsion' refer to?

The term 'asphalt emulsion' specifically refers to a mixture of asphalt, water, and emulsifying agents. This formulation is primarily used for surface treatments, where the emulsifying agents help stabilize the mixture and keep the asphalt suspended in water. Asphalt emulsions are advantageous in many applications, such as paving and chip seals, as they can be applied in a liquid state and provide a bond between layers of aggregate and asphalt.

This composition allows for easier application and often results in less environmental impact compared to traditional hot-mix asphalt. The water content allows for safer handling and can help avoid issues that arise from fumes associated with hot asphalt.

The other options touch on different aspects of asphalt and road construction but do not accurately describe asphalt emulsion. For instance, a complete asphalt mixture used for subbase layers does not involve the water component critical to emulsions. Similarly, while adhesives for road marking lines may play a role in road construction, they are not categorized as asphalt emulsions. Lastly, a recycled product used in asphalt production relates to recycled materials but does not define what asphalt emulsion entails.