What does the bulk specific gravity of a compacted specimen include?

The correct choice accurately reflects that the bulk specific gravity of a compacted asphalt specimen incorporates the volume of voids between binder-coated aggregates. This concept is essential in the evaluation of the compacted HMA's performance.

Bulk specific gravity is an important parameter in asphalt pavement design and analysis because it relates the mass of the compacted material to its volume, taking into account all the existing voids within the asphalt matrix. These voids are spaces not occupied by the aggregate or the asphalt binder itself, but are a crucial factor in determining how well the mix will perform under load and environmental conditions.

Understanding this relationship allows inspectors and engineers to assess factors like density, porosity, and the overall quality of the asphalt mix. It directly influences the mechanical properties of the pavement, including its durability, stability, and resistance to distresses such as rutting and cracking.