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Compaction Testing

Compaction Testing, also known as Density Testing, is most commonly performed using the Sand Cone, or Nuclear (Nuke) Gauge Method. These methods are both quality control earthwork tests. In both cases, the technician performing the tests will begin by identifying a relatively flat area and cutting into the exposed soil surface.

For the sand cone test, the technician will hand excavate a shallow 4-inch diameter hole. The soil excavated from the hole is then carefully captured and weighted. The hole is then filled with sand of a known bulk unit weight – allowing the hole's volume to be calculated. The moisture content of the soil is measured in the lab and the soil density can be determined.

For the nuke gauge test, the technician will punch a 4 to 12-inch deep, 1-inch diameter hole into the soil using a large nail. Then, he/she will line up the nuke gauge on the flat area and lower the nuke pin containing a radiation source into the hole. The gauge will measure the amount of radiation received, and it will calculate the amount blocked from reaching its sensor by the underlying soil. The gauge can then determine the density of the soil.