<p><p><strong>Reference(s):</strong></p><p><em>AASHTO (M288-06)<br>AASHTO (2001)<br>Al-Qadi et al. (1996, 2006)<br>Anderson et al. (1989)<br>Berg et al. (2000)<br>Brown et al. (1982)<br>Collin et al. (1996)<br>Collins et al. (2005)<br>Christopher et al. (2001, 2010)<br>Cuelo et al. (2005)<br>Holtz et al. (2008)<br>Montanelli et al. (1997)<br>Perkins (1999, 2002, 2009)<br>Webster (1992)</em></p><p><strong>Method Summary</strong></p><p>The construction material (asphalt layer, base course, subgrade, and geosynthetic) properties are measured with laboratory testing. The following references have a comprehensive list of laboratory tests that ensure quality control for the subgrade, base course, and geosynthetics used in base course reinforcement: AASHTO (2001), Berg et al (2001), and Holtz et al. (2008), and Christopher et al. (2010). AASHTO (M288-06) is a material specification for geosynthetics used in road construction.</p><p>Laboratory tests include:<br><ul> <li>Geosynthetic Properties:<br><ul> <li>Mass per unit area (ASTM D3776)</li> <li>Geogrid Aperture Size</li> <li>Geogrid Open Area (COE)</li> <li>Geogrid Junction Strength (ASTM 638)</li> <li>Geogrid Flexural Rigidity (ASTM D1388)</li> <li>Geogrid Thickness (ASTM D1777)</li> <li>Geogrid Tensile Test (ASTM D4595)</li> <li>Geotextile Tensile and Elongation Test (ASTM D4632)</li> <li>Geotextile Mullen Burst (ASTM D4632)</li> <li>Geotextile Puncture Test (ASTM D4833)</li> <li>Trapezoidal Tear Test (ASTM D4533)</li> <li>UV Resistance (ASTM D4355)</li> <li>Geotextile Apparent Opening Size (ASTM D4751)</li> <li>Geotextile Permittivity (ASTM D4491)</li> <li>Wide Width Tensile Strength (ASTM D6637)</li> <li>Geosynthetic-Soil Resilient Interface Shear Stiffness (ASTM D7499)</li></ul></li> <li>Subgrade and Base Course Properties:<br><ul> <li>CBR Test (ASTMD1833)</li> <li>Modified Proctor Test (ASTM D1557)</li> <li>Standard Proctor tests (AASHTO T99 and T180)</li> <li>Standard Method of Test for Determining Resilient Modulus of Soils and Aggregate Materials (AASHTO T 307)</li></ul></li> <li>Other lab tests include the following:<br><ul> <li>Soil classification (ASTM D2487-11)</li> <li>Atterberg limits (ASTM D4318-10)</li> <li>Abrasion (ASTM C535-09, ASTM C131-06)</li> <li>Soundness (ASTM C 88)</li></ul></li></ul><strong>Accuracy and Precision</strong></p><p>Laboratory tests on geosynthetics, in-situ soil, borrowed soil, base course material, and asphalt are considered accurate and are standardized by ASTM, AASHTO, and state authorities. The geosynthetic properties, like most manufactured materials, will take fewer tests to maintain accuracy and precision, while tests on in-situ and borrowed soil will take more tests to maintain accuracy and precision.</p><p><strong>Adequacy of Coverage</strong></p><p>Properties for the entire geosynthetic can be confirmed. Coverage will be proportional to the frequency of tests for in-situ and borrow soil properties.</p><p><strong>Implementation Requirements </strong></p><p>Implementation is standardized for the Empirical Design Method. Because of the transition from the Empirical Design Method to the Mechanistic-Empirical Design Method it has become necessary to develop new QC/QA procedures that associate with properties critical to the Mechanistic-Empirical Design Method. Some of these tests include the new tests for resilient modulus, geosynthetic-soil resilient interface shear strength, and dynamic Poison’s ratio for geosynthetics. Generally the geosynthetic manufacturer is required to provide the QC/QA measures for the geosynthetic and provide the documentation to that effect. The responsibility for the QC/QA procedures for the in-situ and borrow materials will vary depending on the specification.</p><p><strong>General Comments</strong></p><p>Laboratory tests are the most common and accurate way to maintain quality control and quality assurance of pavement materials. This method is also well adapted to performing quality control and quality assurance checks on geosynthetics used for reinforcement. As the transition is made from the Empirical Design Method to the Mechanistic-Empirical Design Method, the QC/QA for both method approach and performance approach specifications will need to be expanded to accommodate the increased input and output parameters. For the Mechanistic-Empirical Design Method new laboratory tests include geosynthetic-aggregate interface tests and modified wide-width tensile tests.</p></p>