What is a common method for sampling asphalt?

A core sample taken from the roadway is a standard method for sampling asphalt that provides a physical representation of the asphalt layer's quality and composition. This method involves extracting a cylindrical section of the pavement surface, which allows for an accurate analysis of several important factors, such as the thickness of the asphalt layer, air voids, compacted density, and the overall quality of the asphalt mix. Core samples can also be tested in the laboratory to determine properties such as the Marshall stability, flow, and other performance characteristics, making it a vital practice for quality control and assurance in asphalt paving.

In contrast, visual inspection of the surface layer does not provide quantitative data on the material properties. Weight measurement of loose aggregates focuses on the components that make up the asphalt mixture and does not reflect the actual in-place conditions of the pavement. In-place density measurement, while important for assessing compaction quality, does not give a comprehensive analysis of the asphalt mix's properties like core sampling does. Therefore, taking core samples is essential for assessing the quality and integrity of the asphalt pavement.