<p><p><strong>Reference(s):</strong></p><p><em>Austroads (1998)<br>Little (1995)<br>Qubain et al. (2006)<br>PCA (1980)<br>TRB (1987)<br>White et al. (2005)</em></p><p><strong>Method Summary</strong></p><p>The nuclear gauge method is commonly used to determine compacted field density and moisture content of stabilized soil (ASTM D2922, D3017, and D6938; AASHTO T238 and T239). This is a non-destructive test and can be performed in a matter of a few minutes.</p><p><strong>Accuracy and Precision </strong></p><p>Based on repeatability measurements from a single operator, ASTM D6938 reports a standard deviation for wet density measurements as 0.3 to 1.2 lb/ft³ and for moisture content as 0.3 to 0.5%, depending on the soil type and test method used (direct transmission or back scatter).</p><p><strong>Adequacy of Coverage</strong></p><p>Nuclear moisture/density tests are commonly taken at several locations at intervals of 150 meters (500 feet) in the field.</p><p><strong>Implementation Requirements </strong></p><p>Proper operation, calibration, and maintenance of the equipment are essential. Operator teaching and license is required.</p><p><strong>General Comments </strong></p><p>The nuclear gauge method can be used to determine moisture content of materials at the time construction starts and during processing. Density of field material is checked regularly as well. This method cannot measure density of soil at depths greater than 250 mm to 300 mm (10 inches to 12 inches) below the surface. Comparing laboratory compaction test results with the field moisture-density can provide an indicator to ensure sufficient compaction.</p></p>