<p><p><h2>Preferred QC/QA Procedures</h2>Currently, there is no preferred FHWA document that addresses QC/QA procedures or provides guidelines for high energy Impact Roller (IR) technology.</p><p>Construction quality is achieved by meeting established requirements, as detailed in project plans and specifications, including applicable codes and standards. QC and QA are terms applied to the procedures, measurements, and observations used to ensure that construction satisfies the requirements in the project plans and specifications. QC and QA are often misunderstood and used interchangeably. Herein, QC refers to procedures, measurements, and observations used by the contractor to monitor and control the construction quality such that all applicable requirements are satisfied. QA refers to measurements and observations by the owner or the owner's engineer to provide assurance to the owner that the facility has been constructed in accordance with the plans and specifications.</p><p>The typical components of QC/QA monitoring programs for high energy impact roller technology are listed in Tables 1, 2, and 3.<br><h3>TABLE 1. TYPICAL EXISTING QC/QA PROCEDURES AND MEASUREMENT ITEMS</h3><table class='tablepress' id='tablepress-1986'><thead><th><center>QC or QA</th><th><center>Material or Process</th><th><center>Items</th></thead><tbody><tr><td ><center>QC</td><td ><center>Material Related</td><td >• Moisture/density tests, Index properties, elevation monitoring, vibration monitoring</td></tr><tr><td ><center>QC</td><td ><center>Process Control</td><td >• Speed, weight, number of passes, rolling pattern</td></tr><tr><td ><center>QA</td><td ><center>Material Related</td><td >• Penetration tests, static plate load tests, moisture/density tests, index properties, permeability tests, elevation monitoring
</td></tr><tr><td ><center>QA</td><td ><center>Process Control</td><td >• Visual observation, elevation monitoring, number of passes</td></tr></tbody></table><br><h3>TABLE 2. PERFORMANCE CRITERIA USE IN QC/QA MONITORING PROGRAMS</h3><table class='tablepress' id='tablepress-1987'><thead><th><center>Topics</th><th><center>Items</th></thead><tbody><tr><td ><center>Material Parameters</td><td >• Bearing capacity/shear strength, stiffness/modulus</td></tr><tr><td ><center>System Behavior</td><td >• Elevation monitoring, uniformity
</td></tr></tbody></table><br><h3>TABLE 3. EMERGING QC/QA PROCEDURES AND MEASUREMENT ITEMS</h3><table class='tablepress' id='tablepress-1988'><thead><th><center>Topics</th><th><center>Items</th></thead><tbody><tr><td ><center>Material Related</td><td >• Continuous impact response monitoring, intelligent compaction, dynamic plate load tests, geophysical/seismic testing</td></tr><tr><td ><center>Process Control</td><td >• Global positioning system (GPS) or laser based elevation monitoring systems
</td></tr></tbody></table></p></p>
<p><p><h2>QC/QA Guidelines</h2>Different types of in-situ spot testing methods have been used or potentially can be used for QC/QA for this technology. These methods can be broadly categorized into the following:<br><ul> <li>Penetration tests.</li> <li>Static plate load tests.</li> <li>Dynamic plate load tests.</li> <li>Moisture/density tests.</li> <li>Geophysical/seismic methods.</li> <li>Continuous impact response (CIR) mapping.</li> <li>Permeability/infiltration rate testing.</li> <li>Visual observation.</li> <li>Elevation monitoring.</li> <li>Vibration monitoring.</li></ul>With the exception of CIR mapping and some geophysical test methods (e.g., ground-penetrating radar (GPR)), all other in-situ test methods described above are point measurements. Many test measurements are required to adequately capture the variability associated with soil properties, which leads to more time and construction costs. Different test measurements provide an assessment of different soil properties and are selected based on experience and relevance to the project. Some test methods have limited applications. For example, penetration tests are not viable when large rocks are present, and plate load tests may not be viable on loose sands where the surface is disturbed under impulse loading from the roller. Although test standards or some level of guidelines are available for most of these QC/QA test methods, standardized specifications and guidelines to implement these technologies along with IR technology are not available at this time. Application of CIR with IR technology is not well documented and warrants additional research.</p><p>Inspections, construction observations, daily logs, and record keeping are essential QC/QA activities for all technologies. These activities help to ensure and/or verify that:<br><ul> <li>Good construction practices and the project specifications are followed.</li> <li>Problems can be anticipated before they occur, in some cases.</li> <li>Problems that do arise are caught early, and their cause can oftentimes be identified.</li> <li>All parties are in good communication.</li> <li>The project stays on schedule.</li></ul></p></p>
<p><p><h2>References</h2>Avalle, D.L. (2004a). “Use of the impact roller to reduce agricultural water loss.”<em> Proc. 9th ANZ Conf. on Geomechanics</em>, 8-11 February 8-11, Auckland, Australia.</p><p>Avalle D.L. (2004b). “Ground improvement using the “square” impact roller – case studies.” <em>5th Intl. Conf. on Ground Improvement Techniques</em>, March, Kuala Lumpur, Malaysia.</p><p>Avalle, D.L. (2004c). “Impact rolling in the spectrum of compaction techniques and equipment.” <em>Earthworks Seminar</em>, Australian Geomechanics Society, August, Adelaide, Australia.</p><p>Avalle, D.L. (2007b). “Ground vibrations during impact rolling.” <em>Common Ground 07, Proc., 10<sup>th</sup> Australia New Zealand Conference on Geomechanics</em>, Brisbane, Australia.</p><p>Auzins, N. and Southcott, P.H. (1999). “Minimizing water losses in agriculture through the application of impact rollers,” <em>Proc., 8<sup>th</sup> Intl. Australia-New Zealand Conf. on Geomech., </em>Hobart, Australia.</p><p>Avalle, D.L. and Carter, J.P. (2005). “Evaluating the improvement from impact rolling on sand." <em>Presented at the 6th Intl. Conf. on Ground Improvement Techniques</em>, 18-19 July, Coimbra, Portugal.</p><p>Avalle D.L. and Grounds, R. (2004). “Improving pavement subgrade with the “square” impact roller.” <em>Proc. 23rd Southern African Transport Conference (SATC2004)</em>, 12-15 July, Pretoria, South Africa.</p><p>Avsar, S., Bakker, M., Bartholomeeusen, G., and Vanmechelen, J. (2006). “Six sigma quality improvement of compaction at the new Doha international airport project.” <em>Terra et Aqua</em>, No. 103, June, 14-22.</p><p>Bouazza, A. and Avalle, D.L. (2006a). “Effectiveness of rolling dynamic compaction on an old waste tip.” <em> ISSMGE 5th Intl. Congress on Environmental Geotechnics</em>, 26-30 June, Cardiff, Wales, United Kingdom.</p><p>Bouazza, A. and Avalle, D.L. 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(1999). “Innovative developments in compaction technology using high energy impact compactors.” <em>Proc. 8th ANZ Conf. on Geomechanics</em>, Hobart, Australia. pp. 2-775 to 2-781.</p><p>Pinrad, M.I. (2001). “Development in compaction technology”, <em>Geotechnics for Roads, Rail Tracks, and Earth Structures, </em>Edited by Correia, A.G., and Brandl H., A.A. Balkema Publishers, The Netherlands.</p><p>Scott, B. and Suto, K. (2007). “Case study of ground improvement at an industrial estate containing uncontrolled fill.” <em>Common Ground 07, Proc., 10<sup>th</sup> Australia New Zealand Conference on Geomechanics</em>, Brisbane, Australia.</p><p>Vennapusa, P. and White, D.J. (2009). “Comparison of light weight deflectometer measurements for pavement foundation materials,” <em>Geotechnical Testing Journal, </em>32(3), Paper ID GTJ101704, ASTM.</p><p>White, D.J., Thompson, M., and Vennapusa, P. (2007a). <em>Field validation of intelligent compaction monitori9ng technology for unbound materials, </em>Final Report MN/RC-2007-10, Minnesota Dept. of Transportation, St. Paul, MN, March.</p><p>White, D.J., Vennapusa, P. Suleiman, M.T., and Jahren, C.T. (2007b). “An In-situ Device for Rapid Determination of Permeability for Granular Bases.” <em>Geotechnical Testing Journal</em>, Vol. 30, No. 4, pp. 282–291.</p><p>White, D.J., Vennapusa, P., Gieselman, H., Johanson, L., and Siekmeier, J. (2009). “Alternatives to heavy test rolling for cohesive subgrade assessment.” <em>Proc., 8<sup>th</sup> Intl. Conf. of Bearing Capacity of Roads, Railways, and Airfields (BCR2A’09), </em>June 29-July 2, 2009, Edited By Tutumluer and Al-Qadi, CRC Press, New York.</p></p>