How is the stability of an asphalt mixture typically evaluated?

The stability of an asphalt mixture is typically evaluated through the Marshall Stability Test. This test assesses the mechanical properties of asphalt mixtures, specifically their ability to resist deformation under load. During the Marshall Stability Test, a sample of the asphalt mixture is compacted and then subjected to an increasing load until failure occurs. The peak load sustained by the sample before failure provides a measure of the mixture's stability.

Stability is crucial for ensuring that the asphalt pavement can withstand the traffic loads and environmental conditions over its service life. The test also provides information about the flow, which helps in determining the workability of the asphalt mix. This method has been a long-standing procedure in the asphalt industry, making it a trusted means of evaluating stability.

In contrast, the other options involve different aspects or tests. The Moisture Sensitivity Test evaluates how well a mixture performs in the presence of moisture but does not specifically assess stability under load. The Superpave Gyratory Compactor is used for designing asphalt mixtures and evaluating their density and air voids but does not directly measure stability either. Visual inspection can give qualitative insights but lacks the quantitative assessment required for evaluating the mixture's stability effectively. Thus, the Marshall Stability Test remains the primary method for this evaluation.