What percentage of asphalt is made up of binders?

The correct choice indicates that approximately 5% of asphalt is composed of binders. Binders, primarily asphalt cement, play a crucial role in the composition of asphalt because they are the binding agents that hold the aggregate together, providing the necessary cohesion and structural integrity. This binder not only contributes to the flexibility and durability of the asphalt but also protects the aggregate from environmental factors.

In typical asphalt mixes, the binder content is optimized to ensure the mixture achieves the desired performance characteristics while being cost-effective. While the exact percentage can vary based on the intended use of the asphalt and specific formulations, stating 5% offers a general understanding of the proportion of binders in common asphalt mixtures. This knowledge is essential for public works managers in planning and executing road construction and maintenance projects effectively.