<p><p><strong>Reference(s):</strong></p><p><em>Han et al. (2011)<br>Thakur (2011)<br>Pokharel (2010)</em></p><p><strong>Method Summary</strong></p><p>Pokharel (2010) and Thakur (2011) checked the required subgrade strength by conducting vane shear tests just after preparing the subgrade and four DCP tests were conducted one day after the preparation of a base course at four different locations within the test box to verify the CBR values of the subgrade and base course. After each cyclic plate load test, two sand cone tests in accordance with ASTM D15556-07 were conducted to evaluate the density of the compacted infill material.</p><p>Han et al. (2011) conducted the vane shear test using the hand-operated vane shear device and following the ASTM D2573-08 standard to ensure the uniformity of the subgrade during preparation. Sand cone tests were performed following the ASTM D1556–07 standard to measure the density of the compacted base course during the forensic investigation. A nuclear gauge was used to monitor the level of compaction and density measurement during the compaction. DCP tests were carried out to estimate the CBR values of the test-ready sections in lab and moving wheel test sections.</p><p><strong>Accuracy and Precision</strong></p><p>The method has been successfully used to verify the CBR and density of subgrade and base courses of unpaved roads. The accuracy and precision of the method have been confirmed and vary from medium to high according to the specific test procedure (e.g., nuclear density versus sand cone and DCP versus CBR).</p><p><strong>Adequacy of Coverage</strong></p><p>Vane shear, DCP, and nuclear gauge tests can be performed in a short time. They can be used to evaluate subgrade and base density and strength in a large area; however, these are point tests and often lead to variable results over the area evaluated.</p><p><strong>Implementation Requirements </strong></p><p>Implementation requirements for these tests (except sand cone tests) are not excessive.</p><p><strong>General Comments</strong></p><p>This method is not applicable to a method approach specification, and highly applicable to performance-based specifications. The method can be used for several applications, such as pavement foundation stabilization, construction working platforms, and compaction.</p></p>