<p><p><h2>Preferred QC/QA Procedures</h2>There are no FHWA guidance QC/QA procedures of this technology. QC/QA methods vary depending on the application of the technology and the stage of construction. The various methods are listed below.<br><ul> <li>Static and dynamic plate load tests</li> <li>Ground movement</li> <li>Dynamic core penetration testing</li> <li>Pavement profile</li> <li>Coring</li></ul>Construction quality is achieved by meeting established requirements, as detailed in project plans and specifications, including applicable codes and standards. Quality Control (QC) and Quality Assurance (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, Quality Control refers to procedures, measurements, and observations used by the contractor to monitor and control the construction quality such that all applicable requirements are satisfied. Quality Assurance 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>Table 1 shows the components of QC/QA monitoring programs for lightweight injected foam fill. The entries in the table are a list of typical items, not a list of all methods that could be used for QC/QA. Some QC procedures and measurement items may also serve as QA procedures and measurement items.<br><h3>TABLE 1. TYPICAL EXISTING QC/QA PROCEDURES AND MEASUREMENT ITEMS</h3><table class='tablepress' id='tablepress-1994'><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 >• Monitoring polyurethane strength with time</td></tr><tr><td ><center>QC</td><td ><center>Process Control</td><td >• Construction time and monitoring of ground heave with wire line and laser level</td></tr><tr><td ><center>QA</td><td ><center>Material Related</td><td >• CPT
• Soil Samples
• Confirmation of polyurethane strength
</td></tr><tr><td ><center>QA</td><td ><center>Process Control</td><td >• Monitoring of ground heave with wire line and laser level
</td></tr></tbody></table><br><h3>TABLE 2. PERFORMANCE CRITERIA USE IN QC/QA MONITORING PROGRAMS</h3><table class='tablepress' id='tablepress-1995'><thead><th><center>Topics</th><th><center>Items</th></thead><tbody><tr><td ><center>Material Parameters</td><td >• CPT and soil Samples</td></tr><tr><td ><center>System Behavior</td><td > • Monitoring of ground heave with wire line and laser level</td></tr></tbody></table><br><h3>TABLE 3. EMERGING QC/QA PROCEDURES AND MEASUREMENT ITEMS</h3><table class='tablepress' id='tablepress-1996'><thead><th><center>Topics</th><th><center>Items</th></thead><tbody><tr><td ><center>Material Related</td><td >• Geophysical monitoring techniques for evaluating special variability and pressure meter tests
• Visual CPT
• Pressure meter
• 3-D laser scanning
</td></tr><tr><td ><center>Process Control</td><td >• Pore pressure response in ground stress meter (e.g., dilatometer)</td></tr></tbody></table></p></p>
<p><p><h2>QC/QA Guidelines</h2>Various methods exist for QC/QA programs including static and dynamic plate load tests, ground movement, dynamic core penetration testing, pavement profile, and coring. Dynamic cone penetrometer testing is used to locate the soft spots beneath pavements before injection of material. During the lift process, laser level or string lines can be used to monitor the surface elevation. Cores are taken after construction to check if the polyurethane material has successfully penetrated through pavements. Pavement profile and roughness can be recorded using a walking profiler or high-speed profile before and after injection. Static and dynamic plate load tests are conducted to verify the soil improvement.</p><p>The QC/QA methods are presented in the following sections. However, detailed, site-specific guidelines should be developed for these QC/QA programs to help contractors and field engineers. The polyurethane supplier and contractor will be responsible for material quality. An experienced contractor should select the appropriate methods for QC/QA.</p><p>Ground movement and soil strength are two important factors assessed in QC/QA methods for deep injection projects. Geophysical testing should be developed for QA programs to precisely verify that polyurethane has adequately filled voids.</p></p>
<p><p><h2>References</h2>Abu Al-eis, K. and LaBarca, I.K. (2007). <em>Evaluation of the Uretek Method of Pavement Lifting.</em> WI-02-07, Wisconsin Department of Transportation.</p><p>Christopher, B.R., Schwartz, C. and Boudreau, R. (2010). “Geotechnical Aspects of Pavements,” FHWA-NHI-10-092, Federal Highway Administration, Washington, DC, 568p.</p><p><a href="https://www.nhi.fhwa.dot.gov/training/nhistoresearchresults.aspx?get=&a…, A.B., Albritton, G.G., and Gatlin, G.R. (1996). <em>Evaluation of the Uretek Method Pavement Undersealing and Faulting Correction.</em> Interim Report, FHWA/MA-DOT-RD-96-113, Mississippi Department of Transportation Research Division.</p><p>Gaspard, K. and Morvant, M. (2004). <em>Assessment of the Uretek Process on Continuously Reinforced Concrete Pavement, Jointed Concrete Pavement, and Bridge Approach Slabs.</em> LTRC Project No. 05-1 TA, Louisiana Department of Transportation and Development, Louisiana Transportation Research Center.</p><p>URETEK (2004). <em>The Uretek Deep Injection Process (UDI) for Roadways and Building Structures.</em> URETEK USA, Tomball, TX.</p><p>URETEK (2005). <em>The Uretek Method for Roadways and Transportation Assets.</em> URETEK USA, Tomball, TX.</p><p>Vennapusa, P.K., and White, D.J., (2009). “Comparison of Light Weight Deflectometer</p><p>Measurements for Pavement Foundation Materials.” <em>Geotechnical Testing Journal</em>, Vol. 32, No.3, West Conshohocken, PA, p. 239-251.</p><p> </p></p>