Which method is typically used to measure the density of asphalt concrete in the field?

The method typically used to measure the density of asphalt concrete in the field is the nuclear density gauge. This device employs radioactive isotopes to provide instantaneous density measurements of the asphalt pavement. It is highly effective because it allows for real-time quality assurance of the asphalt paving process, enabling quick assessments of whether the material meets the necessary specifications.

The nuclear density gauge works by emitting gamma radiation and measuring the amount of radiation that returns after passing through the asphalt. The density readings obtained provide crucial information about the asphalt's compaction level and overall quality.

Core sampling, while often used to validate the results obtained from a nuclear density gauge, is a more time-consuming method that requires extracting samples of the pavement for testing in a laboratory setting. Weight measurement can provide a measure of density but is not practical for field use on large asphalt surfaces. Laser scanning, while useful for surface evaluation, does not directly measure density and is not a standard method for assessing the compaction of asphalt concrete.