<p><p><h2>Preferred QC/QA Procedures</h2>The Federal Highway Administration (FHWA) provides QC/QA guidance for this technology. The document <em>Geotechnical Aspects of Pavements</em> emphasizes adequate drainage as one of the important factors for good performance of pavements and has a thorough discussion on QC/QA procedures for pavement systems. The document <em>Geosynthetic Design and Construction Guidelines</em> discusses Manufacturing Quality Control (MQC) and Manufacturing Quality Assurance (MQA) for geosynthetics used in pavement systems.</p><p>QC/QA procedures are also included in the AASHTO (2006) <em>Standard Specifications for Geotextiles - M288</em>.</p><p><table class='tablepress' id='tablepress-1973'><thead><th><center>Publication Title</th><th><center>Publication
Year
</th><th><center>Publication Number</th><th><center>Available for Download</th></thead><tbody><tr><td ><center>Geotechnical Aspects of Pavements</td><td ><center>2010</td><td ><center>FHWA NHI-10-092</td><td ><center>Yes<sup>1</td></tr><tr><td ><center>Geosynthetic Design & Construction Guidelines – Reference Manual</td><td > <center>2008</td><td > <center>FHWA NHI-07-092</td><td > <center>No<sup>2</td></tr></tbody></table><br><p class="disclaimer"><sup>1</sup><a href="https://www.nhi.fhwa.dot.gov/training/nhistoresearchresults.aspx?get=&a… class="disclaimer"><sup>2</sup> <a href="http://www.nhi.fhwa.dot.gov/training/nhistore.aspx">http://www.nhi.fhwa… are QC/QA methods necessary to ensure proper construction and installation of geocomposite pavement edge drain systems and geocomposite prefabricated vertical drains in the pavement system. The proper methods are dependent on the design methods, existing conditions, and desired performance. Important QC/QA procedures include ASTM, AASHTO, and non-proprietary test methods.</p><p>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>The components of QC/QA monitoring programs for Geosynthetics in Pavement Drainage are listed in Tables 1, 2, and 3. 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-1980'><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 >•Surface course, Base course, and Subgrade: CBR, permeability, moisture content, swell and shrink potential, soil classification, grain size distribution, compaction, shear strength, internal friction angle, cohesion, stiffness, ductility, drainage coefficient of pavement layers, and infiltration coefficient of pavement.
•Geosynthetic Properties: tensile strength and elongation, tear strength, puncture strength, permittivity, UV radiation stability, transmissivity, compressive strength, compressive creep, bond strength, sewn seam strength, apparent opening size, percent open area, porosity, thickness, density, mass per unit area.
</td></tr><tr><td ><center>QC</td><td ><center>Process Control</td><td >•Number of lifts, passes and rolling pattern for compaction, width of geosynthetic overlap and seam, longitudinal and lateral slope of pavement, verticality and proper positioning of the drain panel within the trench, backfilling with open graded aggregate, timely installation of outlet fittings and pipes with adequate stiffness
</td></tr><tr><td ><center>QA</td><td ><center>Material Related</td><td >•Nuclear gauge and sand cone density test
</td></tr><tr><td ><center>QA</td><td ><center>Process Control</td><td >•GPR, FWD, field observations, pipe line cameras to inspect edge drains after installation; a pipe box test to evaluate the performance of toe drains.
</td></tr></tbody></table><br><h3>TABLE 2. PERFORMANCE CRITERIA USE IN QC/QA MONITORING PROGRAMS</h3><table class='tablepress' id='tablepress-1981'><thead><th><center>Topics</th><th><center>Items</th></thead><tbody><tr><td ><center>Material Parameters</td><td >•CBR, resilient modulus, relative compaction, rate of outflow</td></tr><tr><td ><center>System Behavior</td><td >•Roughness, International Roughness Index, present serviceability index, rut depth, fatigue cracking.</td></tr></tbody></table><br><h3>TABLE 3. EMERGING QC/QA PROCEDURES AND MEASUREMENT ITEMS</h3><table class='tablepress' id='tablepress-1982'><thead><th><center>Topics</th><th><center>Items</th></thead><tbody><tr><td ><center>Material Related</td><td >•None noted</td></tr><tr><td ><center>Process Control</td><td >•None noted</td></tr></tbody></table></p></p>
<p><p><h2>QC/QA Guidelines</h2>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><strong> </strong>Material property verification and tests are used for both quality control and quality assurance of geosynthetics in pavement drainage. Field control and tests for drainage performance and GPR and FWD tests of pavement structures are used for quality assurance. AASHTO (2006) provides a standard specification for materials used in pavement drainage applications which can be used for the QA/QC purpose. The QC/QA procedure for geosynthetics includes testing for the geosynthetic properties and monitoring of installation of the geosynthetic in the project. The commonly tested geosynthetic properties for this technology are permeability, transmissivity, tensile strength, seam strength, bursting resistance, puncture resistance, tear resistance etc. The use of pipeline cameras to inspect edge drains has provided vital information on the construction, performance, and design of these systems. GPR and FWD tests can determine pavement layer thickness, moisture distribution, resilient modulus, which can be used to estimate the remaining service life of pavements and provide guidance to select the appropriate maintenance and rehabilitation activities.</p><p>Currently, the QA/QC procedure for Geosynthetics in Pavement Drainage could be more comprehensive with regards to performance monitoring. Combining the three QC/QA approaches discussed later in this document is advised in order to allow for a better evaluation of this technology.</p></p>
<p><p><h2>References</h2>Al-Qadi, I.L., Lahouar, S., Loulizi, A., Elseifi, M.A., and Wilkes, J.A. (2004). “Effective approach to improve pavement drainage layers.”<em>Journal of Transportation Engineering</em>, Vol. 130, No. 5, 658-664.</p><p>AASHTO (2006). “<em>Standard Specifications for Geotextiles - M 288</em>.” Standard Specifications for Transportation Materials and Methods of Sampling and Testing, 26<sup>th</sup> Edition, American Association of State Transportation and Highway Officials, Washington, D.C.</p><p>ASTM D6707 (2006). “ Standard specification for circular-knit geotextile for use in subsurface drainage applications.”</p><p>Chew, S.-H., Wong, S.-F., Teoh, T.-L., Karunaratne, G.P., and Tan S.-A. (2000), “Influence of test apparatus on the measurement of transmissivity of geosynthetic drains.” <em>Testing and Performance of Geosynthetics in Subsurface Drainage</em>, ASTM STP 1390, L.D. Suits, J.B. Goddard, and J.S. Baldwin (eds.), American Society for Testing and Materials, Wet Conshohocken, PA.</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…, M.K., Riley, D.G., and Bass T.R. (2000). “Key installation issues impacting the performance of geocomposite pavement edge drain systems.” <em>Testing and Performance of Geosynthetics in Subsurface Drainage</em>, ASTM STP 1390, L.D. Suits, J.B. Goddard, and J.S. Baldwin, Eds., American Society for Testing and Materials, Wet Conshohocken, PA.</p><p>Elseifi, M.A., Al-Qadi, I.L., Loulizi, A., and Wilkes, J. (2001). “Performance of geocomposite membrane as pavement moisture barrier.” <em>Transportation Research Record 1772,</em> TRB, 168-173.</p><p>Holtz, R.D., Christopher, B.R., and Berg, R.R. (2008). “Geosynthetic design and construction guidelines.” <em>Report No. FHWA-NHI-07-092, U.S. Department of Transportation,</em> National Highway Institute, Federal Highway Administration, Washington.</p><p>Koerner, G.R., Koerner, R.M., and Wilson-Fahmy, R.F. (1996). “Field performance of geosynthetic highway drainage systems.” <em>ASTM Special Technical Publication,</em> 165-181.</p><p>Swihart, J.J. (2000). “Full-scale laboratory testing of a toe drain with a geotextile sock.” <em>Testing and Performance of Geosynthetics in Subsurface Drainage</em>, ASTM STP 1390, L.D. Suits, J.B. Goddard, and J.S. Baldwin (eds.), American Society for Testing and Materials, West Conshohocken, PA.</p></p>