<p><p><strong>References:<br></strong><em>Schaefer et al. (2016)<br>Stark et al. (2004b)</em></p><p><strong>Method Summary</strong></p><p>Schaefer et al. (2016) and Stark et al. (2004b) provide recommendations for material testing of the various lightweight fill materials. Testing may involve verification of gradation, strength, particle physical compliance, and/or density, depending on the type of material.</p><p>For geofoam, EPS blocks are typically tested upon delivery to verify manufacturer specified properties. In the literature, this testing is covered under Manufacturing Quality Assurance (MQA). Upon delivery, all EPS blocks should be visually inspected for damage and at least one block of each grade EPS per delivery truck should be checked to verify compliance with minimum dry unit weight and dimensional tolerance. For the first delivery of EPS blocks, at least one block of each grade EPS shall be selected for sampling and testing. Sampling locations are specified in Chapter 9 of NCHRP 24-11 (Stark et al. 2004b). Dry density, compressive strength, flexural strength, elastic limit stress, Young's modulus, and dimensional tolerances should all be tested to verify compliance with minimum values as specified in NCHRP 24-11 (Stark et al. 2004b). Additional EPS blocks should be selected for sampling and testing at a rate of approximately one block per 500 cubic yards of EPS delivered.</p><p>For cellular concrete, density and strength of the concrete as well as density of the foam added to the concrete mixture should be verified. Material standards and minimums should be based upon the initial submittals of accepted cellular concrete samples before beginning construction. To assure that minimum and maximum concrete density requirements are satisfied, the density should be checked and adjusted during initial placement. Subsequently, concrete density should be verified hourly and adjustments made as needed. Concrete cylinder samples should be taken to verify concrete strength at 2, 7, 14, and 28-day intervals. A minimum of two sets of four cylinders should be taken each day during fill placement with a set of four cylinders taken for each 70 cubic yards of cellular concrete. Foam that is added to concrete during mixing should be checked twice per day per mixer to verify density for compliance with the submitted mix design.</p><p>Granular lightweight fills should be examined to assure they meet requirements for gradation, maximum particle dimension, density, and other requirements appropriate for the material. Sampling and testing rates are dependent on specific project and state DOT. A summary of typical requirements for each type of granular lightweight fill material is provided below.</p><p><strong>Expanded Shale, Clay &amp; Slate (ESCS)</strong></p><p><ul> <li>Gradation</li> <li>Particle shape (e.g., angular vs. rounded)</li> <li>Density</li></ul>The Caltrans example specification recommends a maximum density of 673 kg/m³ and a minimum density of 609 kg/m³, as determined in accordance with ASTM C 29.</p><p><strong>Slag</strong></p><p><ul> <li>Gradation</li> <li>Leachate determination</li> <li>Resistance to degradation (AASHTO T 96)</li></ul><strong>Fly Ash</strong></p><p><ul> <li>Gradation</li> <li>Maximum particle dimension</li> <li>Type (typically Class F)</li> <li>Leachate determination based on the EPA Extraction Procedure Toxicity Test</li></ul><strong>Wood Fiber</strong></p><p><ul> <li>Maximum particle dimension</li> <li>Source, wood type, freshness</li></ul>Composition wood products are often forbidden as a wood fiber source, and there are sometimes additional restrictions on the wood variety (e.g., cedar sawdust may be restricted). Only fresh wood fiber should be used as fill in order to promote long life of the project. Washington State Department of Transportation has a visual classification system that can be used to identify degrees of decomposition of wood fibers. This classification system could be used to verify that only fresh wood fibers are used on projects.</p><p><strong>Shredded Tires</strong></p><p><ul> <li>Gradation</li> <li>Maximum particle dimension</li> <li>Contaminant free</li></ul>In addition, it is typically required that at least one sidewall be severed from the tread of each tire, and there are encapsulation requirements for the steel wire contained in the tire’s frame.</p><p><strong>Accuracy and Precision</strong></p><p>In many cases, testing methods are well established and understood, with precisely defined test procedures. However, accurate testing of the more unusual materials may be difficult. For example, gradation analyses of some of the granular fills may be difficult (e.g., tire shreds) due to unusual particle shapes.</p><p><strong> </strong><strong>Adequacy of Coverage</strong></p><p>Only a small percentage of the total volume of material can be tested.</p><p><strong> </strong><strong>Implementation Requirements </strong></p><p>Testing can generally be conducted using standard field or laboratory test equipment.</p><p><strong> </strong><strong>General Comments</strong></p><p>Verification of material properties is important for all applications to assure that assumptions used during design are correct.</p><p>For some lightweight fill materials, there is a need to develop additional guidance for required standards, sampling rates, and test procedures.</p></p>