<p><p><h2>Commentary</h2>Waste materials are typically incorporated into a highway reconstruction project in one of the following ways:<br><ul> <li>Modification of unstable soils</li> <li>Embankment materials</li> <li>Slope stabilization</li> <li>Supplementary cementitious materials for Portland cement concrete mixtures</li> <li>Slag aggregates used in subbases</li> <li>Slag aggregates used in portland cement concrete mixtures</li> <li>Bottom ash used as embankment materi

<p><p><figure id='attachment_2529' style='max-width:600px' class='caption aligncenter'><img class="wp-image-2529" style=“border: 1px solid black;" src="https://www.geoinstitute.org/sites/default/files/geotech-tools-uploads/…; alt="Photograph of a RMI Resonant Breaker used to break up concrete pavements." width="600" height="363" /><figcaption class='caption-text'> Rubbliz

<p><p><figure id='attachment_3335' style='max-width:430px' class='caption aligncenter'><img class="wp-image-3335 size-full" src="https://www.geoinstitute.org/sites/default/files/geotech-tools-uploads/…; alt="Photograph of bridge, the Storrow Drive Connector, part of the Boston Central Artery Project." width="430" height="266" /><figcaption class='caption-text'> Storrow Drive Co

<p><p><strong>Reference(s):</strong></p><p><em>Aiban (2006)<br>Benson and Khire (1994)<br>Cieselski and Collins (1993)<br>FHWA (1998)<br>FIRST (2004)<br>Griffiths &amp; Krstulovich (2002)<br>IEC (2008)<br>IMTIAZ (1991)</em></p><p><strong>Method Summary</strong></p><p>California Bearing Ratio (CBR) is used to evaluate the potential strength of subgrade, subbase, and base course material, including recycled materials for use in road and airfield pavements.

<p><p><strong>Reference(s):</strong></p><p><em>FHWA (1998)<br>FIRST (2004)<br>Griffiths &amp; Krstulovich (2002)<br>IEC (2008)<br>IMTIAZ (1991)</em></p><p><strong>Method Summary</strong></p><p>Standard testing methods that are commonly used to evaluate the properties of the recycled materials as they pertain to the designated application were employed.</p><p><strong>Compressive Strength (ASTM C39)</strong></p><p>This test method is used to deter

<p><p><strong>Reference(s):</strong></p><p><em>Benson and Khire (1994)<br>Cieselski and Collins (1993)<br>Hicks et al. (1995)</em></p><p><strong>Method Summary</strong></p><p>Direct shear tests are performed in accordance with ASTM D3080. To reduce the effects of boundary conditions, a large-scale direct shear device was constructed. Two steel rings were used to construct a shear box 28 cm in diameter and 25 cm deep. Shear and normal stresses are applied with pneumatic and hydraulic actuators.

<p><p><strong>Reference(s):</strong></p><p><em>Zhang and Tao (2006)</em></p><p><strong>Method Summary</strong></p><p>The Dynamic Cone Penetrometer (DCP) is a simple and effective tool for evaluating in-situ strength of pavement layers and subgrade. The device consists of an upper fixed 22.7-inch (575 mm) travel rod with a 17.6-pound (8 kg) falling weight hammer, a lower rod containing an anvil, and a replaceable 60° cone of ¾-inch (20 mm) diameter.

<p><p><strong>Reference(s):</strong></p><p><em>NAIK (2004)<br>Reindl (2003)<br>RMT NCASI (2003)<br>Schimmoller et l. (2000)<br>Solanski (2007)</em></p><p><strong>Method Summary</strong></p><p>Testing the flexural strength of concrete (ASTM C78) requires the use of a simple beam with third-point loading. The results of this test method may be used to determine compliance with specifications or as a basis for proportioning, mixing and placement operations.

Current FHWA Reference(s):
FHWA-RD-97-148 (Chesner, et al. 1998)
FHWA-SA-95-060 (Sullivan 1996)

<p><p><strong>Reference(s):</strong></p><p><em>Hicks et al. (1995)</em></p><p><strong>Method Summary</strong></p><p>The Marshall Stability Test (ASTM D1559), developed by the Corps of Engineers, is used to measure the strength of an asphalt mixture sample previously compacted to a standard laboratory compactive effort.

<p><p><strong>Reference(s):</strong></p><p><em>Sullivan (1996)<br>Swearingen et al. (1992)<br>Warren (2007)<br>Wiles and Shepherd (1999)</em></p><p><strong>Method Summary</strong></p><p>The indirect tensile test procedure is provided by AASHTO T322. The IDT measures the creep compliance and strength of asphalt mixtures using indirect tensile loading techniques at intermediate to low temperatures (&lt;20° C). It analyzes mixtures for low temperature cracking.

<p><p><strong>Reference(s):</strong></p><p><em>Melton and Gardner (2006)</em></p><p><strong>Method Summary</strong></p><p>While a great deal is already known about groundwater contamination, minimal research has been conducted concerning modeling of impacts from recycled material use in a highway environment.

<p><p><strong>Reference(s):</strong></p><p><em>Aiban (2006)<br>Melton and Gardner (2006)</em></p><p><strong>Method Summary</strong></p><p>The United States Environmental Protection Agency (USEPA) land disposal restrictions, otherwise known as the land bans, have introduced toxicity characteristic regulatory levels. These regulatory levels define the cutoff levels for a waste.

<p><p><div><h2>Project Summary/Scope:</h2>The project involved incorporating shredded tires in highway embankments. Locally available Waste Tire (WT) chips and soils were used in different combinations in the test embankment. Embankment material varied from pure WT chips, chips mixed with soil, and WT chips layered with soils.

<p><p><strong>Reference(s):</strong></p><p><em>RMT NCASI (2003)<br>Schimmoller et l. (2000)<br>Solanski (2007)</em></p><p><strong>Method Summary</strong></p><p>AASHTO T283 is a test method that can be used to determine if the materials may be subject to stripping and also to measure the effectiveness of additives. To help prevent stripping, additives such as hydrated lime or liquid anti-stripping chemicals may be required.

<p><p><strong>Reference(s):</strong></p><p><em>Aiban (2006)<br>Hicks et al. (1995)<br>NAIK (2004)<br>Reindl (2003)<br>RMT NCASI (2003)<br>Schimmoller et l. (2000)<br>Solanski (2007)</em></p><p><strong>Method Summary</strong></p><p>Soils consist of particles with various shapes and sizes. This test method (ASTM D6913) is used to separate particles into size ranges and to determine quantitatively the mass of particles in each range.

<p><p><strong>Reference(s):</strong></p><p><em>Benson and Khire (1994)<br>Cieselski and Collins (1993)<br>Hicks et al. (1995)<br>Sullivan (1996)<br>Swearingen et al. (1992)<br>Zhang and Tao (2006)</em></p><p><strong>Method Summary</strong></p><p>Strips of High Density Polyethylene (HDPE) are mixed with portage sand and tested to determine the secant modulus, resilient modulus, and shear strength.

<p><p><strong>Reference(s):</strong></p><p><em>AMEC (2006)<br>Warren (2007)<br>Wiles and Shepherd (1999)<br>Zhang and Tao (2006)</em></p><p><strong>Method Summary</strong></p><p>The test for unconfined compressive strength is covered by ASTM D1633. This standard describes two test methods. Method A makes use of the same compaction equipment and molds used for other soil-cement tests commonly available in geotechnical laboratories.