Which of the following components is included in the mix for S 12.5C?

The inclusion of PG 70-22 asphalt binder in the mix for S 12.5C is essential because this specific grade of binder is designed to perform optimally in a variety of temperature conditions. PG (performance grade) asphalt binders are categorized based on their performance capabilities at different temperatures and conditions, and the 70-22 grade indicates it's suitable for high-temperature performance as well as for resistance to low-temperature cracking.

Using PG 70-22 in the mix contributes to the overall durability and longevity of the pavement. It ensures that the roadway can withstand the stresses and strains it experiences from traffic load, temperature fluctuations, and environmental conditions, which is vital for maintaining the structural integrity of the roadway over time.

In contrast, other components listed such as concrete aggregates, steel fibers, and glass beads serve different purposes, typically relating to materials for different types of constructions, like concrete pavement or surface treatments, rather than asphalt pavement mixes specified under S 12.5C. Thus, they would not be appropriate components for the asphalt mix in question.