Which test determines the compactness of asphalt samples?

The Marshall stability test is specifically designed to assess the compactness and strength of asphalt samples. In this test, asphalt mixture samples are compacted and then subjected to a load until failure occurs. The maximum load that the sample can withstand, along with the flow value (which indicates deformation), reflects the structural integrity and compactness of the asphalt.

By determining the stability and flow values, engineers can derive important insights about the performance of asphalt under traffic loads, which is critical for pavement design and ensuring longevity. The method is widely accepted in evaluating the quality and compactness of asphalt mixes, making it essential for materials engineers involved in road construction and rehabilitation projects.

The other tests, while useful for various aspects of asphalt performance, do not directly measure compactness in the same manner as the Marshall stability test. For instance, the specific gravity test evaluates the density of materials rather than compactness, while the indirect tensile strength test focuses on the tensile strength rather than compactness. The dynamic modulus test examines the stiffness of the asphalt pavement response to loading conditions rather than its compactness directly. Therefore, the Marshall stability test is the most appropriate choice for determining the compactness of asphalt samples.