What is the primary purpose of core sampling in asphalt paving?

The primary purpose of core sampling in asphalt paving is to test density and permeability. Core sampling involves extracting a cylindrical section of the asphalt material from the pavement. This allows for a direct measurement of the material's density, which is crucial for ensuring that the asphalt has been compacted properly. Proper compaction affects the durability, strength, and lifespan of the pavement.

In addition to density, core samples are useful for assessing permeability, which refers to how easily water can seep through the asphalt. High permeability can lead to water infiltration, which may cause damage to the underlying layers and result in premature failure of the pavement. By analyzing these factors through core sampling, engineers can make informed decisions regarding the quality of the asphalt and whether adjustments are necessary for future paving projects.

The other options do not align with the primary objectives of core sampling. While color variation can be noted visually, it is not a critical factor assessed through core sampling. Evaluating aesthetic quality is not a typical focus for core samples, as the aim is to ensure structural integrity and performance rather than appearance. Similarly, detecting air bubbles in the mix is also not a primary purpose; instead, core sampling targets the compactness and overall physical properties of the asphalt.