Name a common method to test soil density on site.

Nuclear density testing is commonly used on construction sites to measure soil density because it provides quick and accurate results for both moisture content and density. This method involves using radioactive isotopes to emit gamma radiation, which penetrates the soil. The amount of radiation that is reflected back to the device helps determine the density of the soil. Operators can obtain immediate readings, making this method efficient for real-time assessments and for ensuring that soil compaction meets project specifications.

In contrast to the other methods, nuclear density testing is specifically designed for in-situ measurements, allowing inspectors to assess conditions without needing to excavate samples. Water displacement testing, while valuable in some geological studies, is less common in highway construction settings for soil density assessments. Gravimetric testing can also be used but generally requires soil samples to be taken back to a lab for analysis, which is less efficient than on-site testing. Vibrational testing is primarily used for assessing the response of structures or materials to vibrational forces rather than measuring soil density directly.