<p><p><h2>Preferred QC/QA Procedures</h2>The Federal Highway Administration (FHWA) provided QC/QA guidance for this technology. The documents are summarized below.</p><p><table class='tablepress' id='tablepress-1914'><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>User Guidelines for Waste and By-Product Materials in Pavement Construction</td><td > <center>1998</td><td > <center>Rep. No. FHWA-RD-97-148</td><td > <center>Yes<sup>1</td></tr></tbody></table><br><p class="disclaimer"><sup>1</sup> <a href="http://www.fhwa.dot.gov/pavement/pub_details.cfm?id=384">http://www.fhw… 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 beneficial reuse of waste materials are listed in Tables 1, 2, and 3. The entries in the tables 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.</p><p>QC/QA procedures are presented here for three common waste materials: coal bottom ash/boiler slag, reclaimed asphalt pavement (cold recycling), and reclaimed concrete material (RCM). The materials are the same as those covered in the design guidance documents.</p></p>
<p><p><h2>References</h2>Aiban, S.A. (2006). Utilization of Steel Slag Aggregate for Road Bases, J. of Testing and Evaluation, Vol. 34 (1).</p><p>AMEC (2006). The Beneficial Use of Waste, AMEC Earth & Environmental, Calgary, Alberta, Rep. No. CE03316.</p><p>Benson, C. and Khire, M. (1994), Reinforcing Sand with Strips of Reclaimed High Density Polyethylene, <em>J. of Geotech. Eng.,</em> ASCE, 120(5): 838-855.</p><p>EPA (2005). Using coal ash in highway construction: A guide to benefits and impacts, Rep. no. EPA-530-K-05-002.</p><p>FHWA (1993). A Study of the Use of Recycled Paving Material- Report to Congress. FHWA-RD-93-147, EPA/600/R-93/095.</p><p>FHWA (1998). User Guidelines for Waste and By-Product Materials in Pavement Construction, Rep. No. FHWA-RD-97-148.</p><p>FHWA (2003). Fly Ash Facts for Highway Engineers, American Coal Ash Association, Rep. no. FHWA-03-019.</p><p>FIRST (2004). Foundry Sand Facts for Civil Engineers, Foundry Industry Recycling Starts Today (FIRST), Rep. no. FHWA-IF-04-004.</p><p>Griffiths, C.T. and Krstulovich, J.M., Jr. (2002). Utilization of Recycled Materials in Illinois Highway Construction, Rep. No. IL-PRR-142.</p><p>Grosenheider, K., Bloom, P., Halbach, T., and Simcik, M. (2006). “Chemical inventory and database development for recycled material substitutes.” Minnesota Department of Transportation, MN/RC-2006-28.</p><p>Hicks, R.G., Lundy, J.R., Leahy, R.B., Hanson, D., and Epps, J. (1995). Crumb Rubber Modifiers (Crm) In Asphalt Pavements: Summary of Practices in Arizona, California, and Florida, Report No. FHWA-SA-95-056.</p><p>Industrial Economics, Incorporated (IEc) (2008). Beneficial Use of Secondary Materials - Coal Combustion Products, Waste and Materials-Flow Benchmark Sector Report, Economics, Methods, and Risk Analysis Division, Office of Solid Waste, U.S. Environmental Protection Agency Washington, DC.</p><p>Imtiaz, A. (1991). Use of Waste Materials in Highway Construction, Report No. FHWA/IN/JHRP-91/3.</p><p>Melton, J.S. and Gardner, K.H. (2006). Use of EPA’s Industrial Waste Management Evaluation Model (IWEM) to Support Benificial Use Determinations, Final Report, Recycled Materials Resource Center, Gregg Hall, University of New Hampshire, Durham, NH, 03824.</p><p>Naik, T.R. (2004). Recent advances in recycling clean coal ash, Center for By-Products Utilization, Rep. No. CBU-2004-09.</p><p>RMT, Inc. (2003). Beneficial Use of Industrial By-Products, Identification and Review of Material Specifications, Performance Standards, and Technical Guidance, Rep. prepared for NCASI.</p><p>Schimmoller, V.E., Holtz, K., Eighmy, T.T., Wiles, C., Smith, M., Malasheskie, G., Rohrbach, G.J., Schaftlein, S., Helms, G., Campbell, R.D., van Deusen, D.H., Ford, B., and Almborg, J.A. (2000). Recycled Materials in European Highway Environments: Uses, Technologies, and Policies, Rep. No. FHWA- PL-00-025.</p><p>Solanki, P., Khoury, N., and Zaman, M. (2007). “Engineering behavior and microstructure of soil stabilized with cement kiln dust.” GeoDenver 2007, GSP-172: Soil Improvement.</p><p>Sullivan, J. (1996). Pavement Recycling Executive Summary and Report. FHWA-SA-95-060.</p><p>Swearingen, D.L., Jackson, N.C., and Anderson, K.W. (1992). Use of recycled materials in highway construction, Rep. No. WA-RD 252.1.</p><p>Warren, J.D., Chong, W.K., and Kim, C. (2007). Recycling Construction and Demolition Waste for Construction in Kansas City metropolitan Area, Kansas and Missouri, TRB, No. 2011, Washington, DC, pp. 193-200.</p><p>Wiles, C. and Shepherd, P. (1999). Beneficial Use and Recycling of Municipal Waste Combustion Residues - A Comprehensive Resource Document, <em>National Renewable Energy Laboratory</em>, Rep. no. NREL/BK-570-25841.</p><p>Zhang, Z. and M. Tao (2006). Stability of Calcium Sulfate Base Course in a Wet Environment, LTRC Project No. 03-8GT, Louisiana Transportation Research Center.</p></p>
<div class='content-section' id='qc-qa-procedures-for-coal-bottom-ash-boiler-slag' title='QC/QA Procedures for Coal bottom Ash/Boiler Slag'><p><p><h2>QC/QA Procedures for Coal bottom Ash/Boiler Slag</h2>Stabilized base materials containing bottom ash and/or boiler slag subjected to freezing and thawing conditions must be able to develop a certain level of cementing action and in-place strength prior to the first freeze-thaw cycle in order to withstand the disruptive forces of such cycles. For northern states, many state transportation agencies have established construction cutoff dates for stabilized base materials. These cutoff dates ordinarily range from September 15 to October 15, depending on the state, or the location within a particular state, as well as the ability of the stabilized base mixture to develop a minimum desired compressive strength within a specified time period.</p><p>State transportation agencies have long considered the effects of shrinkage cracking associated with stabilized base mixtures, especially cement-stabilized mixtures. Since most bottom ash and/or boiler slag mixtures have been placed on secondary roads, haul roads, and parking lots, as opposed to higher-type highway facilities, the issue of crack control has not been as great a concern to the owners or administrators of these installations. However, additional mix designs with reduced potential for shrinkage cracking need to be developed, especially if these materials are someday to be used on higher-type facilities.</p><p> </p></p></div>
<div class='content-section' id='qc-qa-procedures-for-reclaimed-asphalt-pavement-cold-recycling-' title='QC/QA Procedures for Reclaimed Asphalt Pavement (Cold recycling)'><p><p><h2>QC/QA Procedures for Reclaimed Asphalt Pavement (Cold recycling)</h2>Quality control is necessary to ensure that the processed RAP will be suitable for the prospective application. To ensure the consistency and quality of a recycled cold plant mix, quality control of the RAP is essential. Random samples of the RAP or recycled material should be analyzed for aggregate gradation, asphalt cement content, and moisture content. The recycled material must be closely inspected to make sure that the RAP is consistent in size and appearance and that subgrade soil (or other possible contaminants) has not been included in the RAP. The amount of any additional aggregate being mixed with the RAP should also be monitored. Loose samples of the recycled mix should be obtained and extraction tests performed to monitor mix gradation, asphalt content, and moisture content. Mixes should be sampled in accordance with AASHTO T168. Achieving the proper compaction or densification of the paving material is essential to proper performance. A test strip should be used at the start of the project to establish a target density and number of roller passes needed to achieve that density. The in-place density of the cold mix paving material can then be monitored with a nuclear density gauge in accordance with ASTM D2950.</p></p></div>
<div class='content-section' id='qc-qa-procedures-for-reclaimed-concrete-material-rcm-' title='QC/QA Procedures for Reclaimed Concrete Material (RCM)'><p><p><h2>QC/QA Procedures for Reclaimed Concrete Material (RCM)</h2>Levels of impurities such as sulfate and chloride ions, alkali-reactive aggregate, and freeze-thaw susceptible aggregate (which can lead to D-cracking in concrete pavements) must be controlled to ensure that the finished concrete has consistent strength and durability. D-cracks are closely spaced cracks parallel to transverse and longitudinal joints that multiply outward to the center of the pavement panel. These cracks typically start in the saturated aggregate at the base of the pavement and progress upward. It has been recommended that the degree of contamination and potential reactivity of RCM aggregates should not exceed the limits permitted for virgin aggregate.</p><p>The same quality-control procedures for conventional Portland cement concrete pavement are required for Portland cement concrete incorporating RCM aggregates. The slump, air content, and temperature of the plastic concrete should be monitored at the time of placement. Compressive strength cylinders should be cast for compressive strength determinations in accordance with the ASTM C39 procedure. Flexural strength can be determined using flexural strength prisms (ASTM C78) or by splitting tensile tests (ASTM C496) on cylinders. Due to the sensitivity of concrete pavement performance and durability to water-cement ratio, and the potential variability in RCM gradation, specific gravity, and absorption, particular attention should be given to these aggregate properties when using RCM in concrete pavement mixtures. Appropriate adjustments to the quantity of mixing water should be made during concrete production.<br><h3>TABLE 1. TYPICAL EXISTING QC/QA PROCEDURES AND MEASUREMENT ITEMS</h3><table class='tablepress' id='tablepress-1915'><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 >•Marshall stability values, immersion-compression, moisture-density relationship, shear strength, durability, soundness, compaction</td></tr><tr><td ><center>QC</td><td > <center>Process Control</td><td >•Compressive strength and durability testing, mix design testing</td></tr><tr><td ><center>QA</td><td > <center>Material Related</td><td >•Mix design testing & field testing related to density, tensile strength and resilient modulus</td></tr><tr><td ><center>QA</td><td ><center>Process Control</td><td >•Stockpiles testing, moisture evaluation, gradation</td></tr></tbody></table><br><h3>TABLE 2. PERFORMANCE CRITERIA USE IN QC/QA MONITORING PROGRAMS</h3><table class='tablepress' id='tablepress-1916'><thead><th><center>Topics</th><th><center>Items</th></thead><tbody><tr><td ><center>Material Parameters</td><td >•Specific gravity, soundness, gradation, strength, workability</td></tr><tr><td ><center>System Behavior</td><td >•QC programs</td></tr></tbody></table><br><h3>TABLE 3. EMERGING QC/QA PROCEDURES AND MEASUREMENT ITEMS</h3><table class='tablepress' id='tablepress-1917'><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></div>