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Suggested Citation:"References ." National Academies of Sciences, Engineering, and Medicine. 2015. Methods and Practices on Reduction and Elimination of Asphalt Mix Segregation. Washington, DC: The National Academies Press. doi: 10.17226/22131.
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Suggested Citation:"References ." National Academies of Sciences, Engineering, and Medicine. 2015. Methods and Practices on Reduction and Elimination of Asphalt Mix Segregation. Washington, DC: The National Academies Press. doi: 10.17226/22131.
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Page 76
Suggested Citation:"References ." National Academies of Sciences, Engineering, and Medicine. 2015. Methods and Practices on Reduction and Elimination of Asphalt Mix Segregation. Washington, DC: The National Academies Press. doi: 10.17226/22131.
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Suggested Citation:"References ." National Academies of Sciences, Engineering, and Medicine. 2015. Methods and Practices on Reduction and Elimination of Asphalt Mix Segregation. Washington, DC: The National Academies Press. doi: 10.17226/22131.
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75 REFERENCES Abu-Hassan, M., Sampling Location Impact on Measuring Asphalt Content of Hot Mix Asphalt, Report No. CDOT- DTD-R-2002-12, Colorado Department of Transporta- tion, Denver, 2002 [Online]. Available: http://www. coloradodot.info/programs/research/pdfs/2002/asphalt sampling.pdf [accessed July 17, 2013]. Adams, J., R. Mulvaney, B. Reprovich, and B. Worel, “Inves- tigation of Construction-Related Asphalt Concrete Pave- ment Temperature Differentials,” Office of Materials and Road Research, Minnesota Department of Transportation, Maplewood, Oct. 2001 [Online]. Available: http://www. mrr.dot.state.mn.us/research/pdf/2001mrrdoc005.pdf [accessed July 5, 2013]. Advanced Asphalt Technologies, LLC, NCHRP Report 673: A Manual for Design of Hot-Mix Asphalt with Commen- tary, Transportation Research Board of the National Acad- emies, Washington, D.C., 2011 [Online]. Available: http:// www.nap.edu/openbook.php?record_id=14524 [accessed June 7, 2013]. Al-Qadi, I.L. and S. Lahouar, “Use of GPR for Thickness Measurement and Quality Control of Flexible Pavements,” Association of Asphalt Paving Technologists, Vol. 73, Mar. 2004, pp. 501–528. American Association of State Highway and Transportation Officials (AASHTO), “Segregation: Causes and Cures for Hot Mix Asphalt,” Publication by the Joint Task Force on Segregation of AASHTO Subcommittee on Construc- tion; AASHTO Subcommittee on Materials; and National Asphalt Pavement Association, AASHTO, Washington, D.C., 1997 [Online]. Available: http://www.in.gov/indot/ files/segregationAsphalt.pdf [accessed Aug. 15, 2013]. Applied Pavement Technology (APT), “Circular Texture Meter Overview,” APT, Urbana, Ill., 2008 [Online]. Avail- able: http://www.appliedpavement.com/techResources_ equipLoanProg_ctmeter.html [accessed Mar. 20, 2014]. Astec, Inc., “Storage Bin Segregation, Chattanooga, Tenn., 2010 [Online]. Available: http://tecspot.astecinc.com/ category/products/storage-bins/ [accessed Jan. 20, 2014] and http://tecspot.astecinc.com/2010/11/storage-bin- segregation/ [accessed June 2013]. Bateman, A., “Tracked MTV Targets Multiple Application,” Rock to Road, Oct.–Nov. 2009 [Online]. Available: http:// www.rocktoroad.com/index.php?option=com_content& task=view&id=993&Itemid=134 [accessed May 15, 2014]. Bode, T.A., An Analysis of the Impacts of Temperature Seg- regation on Hot Mix Asphalt, Dissertation, Construction Systems Department, University of Nebraska–Lincoln, Sept. 1, 2012 [Online]. Available: http://commons@unl. edu/constructiondiss [accessed June 27, 2013]. Brock, D. and H. Jakob, “Temperature Segregation- Temperature Differential Damage,” Technical Paper T-134, Astec Industries, Inc., Urbana, Ill., 1999 [Online]. Available: http://www.roadtec.com/images/uploads/productdocs/ t134_techpaper_temperaturesegregation.pdf [accessed Jan. 15, 2014]. Brock, J.D., J.G. May, and G. Renegar, “Hot Mix Asphalt Segregation: Causes and Cures,” Quality Improvement Series 110/86, National Asphalt Pavement Association, Riverdale, Md., 1998 [Online]. Available: http://inti.gob.ar/ cirsoc/pdf/tecnologia_hormigon/T-117_Segregation_ Causes_Cures.pdf [accessed Aug. 15, 2013]. BS EN 12697-15:2003 Bituminous mixtures—Test methods for hot mix asphalt. Part 15: Determination of the segrega- tion sensitivity. Buncher, M.S. and C. Rosenberg, “Best Practices for Con- struction and Specifying HMA Longitudinal Joints,” Asphalt Institute and Federal Highway Administration draft final report, May 2012 [Online]. Available: http:// www.asphaltinstitute.org/dotAsset/69e25ae4-a615- 4e51-89d4-84e6bbed31ac.pdf [accessed June 27, 2013]. Cerdas, S.F., Thermal Segregation: Causes and Effects on In-Place Density and Fatigue Performance of Asphalt Mixtures, Master’s Thesis, Auburn University, May 2012 [Online]. Available: http://etd.auburn.edu/etd/handle/ 10415/3028 [accessed Oct. 2, 2012]. Cho, Y.K., Y.R. Kim, and T. Bode, Infrared Thermography- Driven Flaw Detection and Evaluation of Hot Mix Asphalt Pavements, Nebraska Transportation Center, Lincoln, Report No. SPR-PI (08) P309, Jan. 2010 [Online]. Avail- able: http://nlcs1.nlc.state.ne.us/epubs/R6000/B016.0145- 2010.pdf [accessed Sept. 20, 2013]. Cleaver, L., “Longer Life for Your Mat,” ForConstructionPros. com™, Mar. 20, 2012 [Online]. Available: http://www. forconstructionpros.com/article/10658939/longer-life-for- your-mat [accessed June 28, 2013]. De Freitas, E.F., P. Pereira, L. Picado-Santos, and A.T. Papagiannakis, “Effect of Construction Quality, Temper- ature, and Rutting on Initiation of Top-Down Cracking,” Transportation Research Record: Journal of the Transpor- tation Research Board, No. 1929, Transportation Research Board of the National Academies, Washington, D.C., 2005, pp. 174 –182. de Leon Izzepi, E.D., G.W. Flintsch, and A.L. Abbott, Mea- suring the Uniformity of Hot Mix Asphalt Pavements with Digital Image Technology, Dissertation, Civil and Environmental Engineering, Virginia Polytechnic Insti- tute and State University, Blacksburg, Sept. 21, 2006 [Online]. Available: http://scholar.lib.vt.edu/theses/avail able/etd-10062006-011435/unrestricted/Diss_EDL.pdf [accessed July 7, 2013]. de Leon Izzepi, E.D. and G.W. Flintsch, Application of Digital Image Technology to Measure Hot Mix Asphalt Homoge- neity, Dissertation, Civil and Environmental Engineer- ing, Virginia Polytechnic Institute and State University, Blacksburg, Sept. 21, 2006a [Online]. Available: http:// scholar.lib.vt.edu/theses/available/etd-10062006-011435/ unrestricted/Diss_EDL.pdf [accessed July 7, 2013].

76 de Leon Izzepi, E.D. and G.W. Flintsch, High-Speed, Non-Contact Imaging System for Inspection of Hot-Mix Asphalt Pavement, Dissertation, Civil and Environmen- tal Engineering, Virginia Polytechnic Institute and State University, Blacksburg, Sept. 21, 2006b [Online]. http:// scholar.lib.vt.edu/theses/available/etd-10062006-011435/ unrestricted/Diss_EDL.pdf [accessed July 7, 2013]. Dixon, M., “Non-Destructive Density Gauge Use on Asphalt Pavement,” Troxler Electronic Laboratories, n.d. [Online]. Available: http://www.apao.org/documents/NuclearGauge UseonAsphaltPavement_Dixon.pdf [accessed June 30, 2014]. Federal Highway Administration (FHWA), “Pavement Preser- vation Checklist Series 3: Thin Hot-Mix Asphalt Overlay,” FP2, FHWA, Washington, D.C., Sept. 2002 [Online]. Avail- able: http://www.wsdot.wa.gov/NR/rdonlyres/7F43DCD4- 0136-4842-AC82-B0C897BB3038/0/ppcl03.pdf [accessed June 28, 2013]. Feng, X., S. Ye, and P. Hao, “A New Laboratory Method to Characterize Gradation and Segregation of Asphalt Mixes,” Construction and Building Materials, Vol. 38, 2013, pp. 1199–1203. Flintsch, G.W., K.K. McGhee, and E. de Leon Izzepi, “Field Validation of Macrotexture-Based Hot Mix Asphalt Seg- regation Detection Methods,” Journal of Association of Asphalt Paving Technologists, Vol. 74, 2005 [Online]. Available: http://scholar.lib.vt.edu/theses/available/etd- 10062006-011435/unrestricted/Diss_EDL.pdf [accessed Oct. 11, 2013]. ForConstructionPros.com, “Smooth, Consistent and Continuous,” 2012 [Online]. Available: http://www. forconstructionpros.com/article/10837622/smooth- consistent-and-continuous [accessed Oct. 11, 2013]. Gavin, J. and D. Heath, Paving Guidelines and Segregation Rating Manual, Technical Standards Branch, Highway Engi- neering Section, Alberta Ministry of Transportation, 2002 [Online]. Available: http://www.transportation.alberta.ca/ Content/docType233/Production/pavsegman.pdf [accessed July 7, 2013]. Gilbert, K., Thermal Segregation, Report No. CDOT-DTD- R-2005-16, Colorado Department of Transportation, Denver, Nov. 2005 [Online]. Available: http://www. coloradodot.info/programs/research/pdfs/2005/thermal segregation.pdf [accessed Sept. 1, 2013]. Gunter, C.B., Field Evaluation of Temperature Differential in HMA Mixtures, Report No. FHWA-SC-12-02, South Carolina Department of Transportation, Columbia, May 2012 [Online]. Available: http://www.clemson.edu/t3s/ scdot/pdf/projects/SPR%20673%20Thermal%20 Segg%20Final%20Report.pdf [accessed June 27, 2013]. Hanson, D. and B. Prowell, “Evaluation of Circular Texture Meter for Measuring Surface Texture of Pavements,” 2004 [Online]. Available: http://www.pavetrack.com/documents/ NCAT%20Reports/04-05%20Evaluation%20of% 20Circular%20Texture%20Meter%20for%20Measuring %20Surface%20Texture%20of%20Pavements.pdf [accessed June 30, 2014]. Harmelink, D., S. Shuler, and T. Ascenbrener, “Top-Down Cracking in Asphalt Pavements: Causes, Effects, and Cures,” Journal of Transportation Engineering, Vol. 134, 2008, pp. 1–6. Harris, J.K., The Effect of Material Transfer Device on Pavement Smoothness, Master’s thesis, Civil Engineering Department, Auburn University, Auburn, Ala., Dec. 2002. Haskell, B., “Intelligent Asphalt Compaction Analyzer,” Highways for LIFE Technology Partnerships Program Progress Report, Haskell Lemon Construction Company, Norman, Okla., 2007 [Online]. Available: http://www.fhwa. dot.gov/hfl/partnerships/haskell/phase1/index.cfm [accessed July 28, 2014]. Henault, J.W., K.R. Lane, and J.M. Sime, Development of Guidelines for Reduction of Temperature Differential Damage (TTD) for Hot Mix Asphalt Pavement Projects in Connecticut—Construction Report, Research Report No. 2222-1-99-5, Division of Research, Bureau of Engi- neering and Highway Operations, Connecticut Department of Transportation, Hartford, Nov. 1999 [Online]. http:// www.ct.gov/dot/LIB/dot/documents/dresearch/CT- 2222-F-04-9.pdf [accessed June 27, 2013]. Henault, J., D.A. Larsen, and J.J. Scully, Development of Guidelines for Reduction of Temperature Differential Damage (TDD) for Hot Mix Asphalt Pavement Projects in Connecticut, Construction Report No. 2222-F-04-9, Connecticut Department of Transportation, Hartford, Dec. 2005 [Online]. Available: http://www.ct.gov/dot/ LIB/dot/documents/dresearch/CT-2222-F-04-9.pdf [accessed Sept. 2, 2013]. Mahoney, J., S.A. Zinke, J.E. Stephens, L.A. Myers, and A.J. DaDalt, Application of Infrared Thermographic Imaging to Bituminous Concrete Pavements—Final Report, Report No. 2229-F-03-7, Connecticut Advanced Pavement Labo- ratory, Connecticut Transportation Institute, School of Engineering, University of Connecticut, Storrs, Nov. 2003 [Online]. Available: http://www.caplab.uconn.edu/pdfs/ thermal_imaging_final-rpt.pdf [accessed July 20, 2013]. Marais, H. and D. Pretorius, “Innovative Design Methods for HMA in Gauteng,” SABITA Digest, Southern African Bitumen Association (Publisher), Pinelands 7505, South Africa, Mar. 2007 [Online]. Available: www.sabita.co.za/ documents/DIGEST-06.pdf [accessed Nov. 2013]. McGhee, K., “Application of High Speed Texture Measure- ment to Traditional Hot Mix Asphalt Acceptance Test- ing,” Materials Evaluation, Vol. 62, No. 7, July 2004, pp. 784–789. McGhee, K.K., G.W. Flintsch, and E. de León, Using High- Speed Texture Measurement to Improve the Uniformity of Hot-Mix Asphalt, Technical Report VTRC 03-R12, Virginia Transportation Research Council and Federal Highway Administration, Charlottesville, May 2003, p. 23 [Online]. Available: http://www.virginiadot.org/vtrc/main/online_ reports/pdf/03-r12.pdf [accessed Oct. 30, 2013]. Meegoda, J.N., G.M. Rowe, A. Jumikis, C.H. Hettiarachchi, N. Bandara, and N. Gephart, “Detection of Surface Segre-

77 gation Using LASER,” CD-ROM, 82nd Annual Meeting of the Transportation Research Board, Washington D.C., Jan. 12–16, 2003 [Online]. Available: www.ltrc.lsu.edu/ TRB_82/TRB2003-001764.pd [accessed Sept. 20, 2013]. Meegoda, J.N., G.M. Rowe, C.H. Hettiarachchi, N. Bandara, and M.J. Sharrock, Correlation of Surface Texture, Seg- regation and Measurement of Air Voids, Report FHWA- NJ-2002-026, New Jersey Department of Transportation and Abatech, Trenton, 2002 [Online]. Available: http:// transportation.njit.edu/nctip/final_report/Correlation OfSurfaceTextureSegregation.pdf [accessed June 27, 2013]. Murphy, T., Segregation of Hot Mix Asphalt: Observations, Evaluations, and Recommendations, Murphy Pavement Technology, Inc., Chicago, Ill., 2012a [Online]. Available: www.murphypavetech.com [accessed Nov. 15, 2013]. Murphy, T., Segregation: The Cardiac Arrest of Hot Mix Asphalt Pavements, Murphy Pavement Technology, Inc., Chicago, Ill., 2012b [Online]. Available: www.murphy pavetech.com [accessed Nov. 15, 2013]. Nener-Plante, D.J. and A. Zofka, “Long-Term Study on Asphalt Mixture Segregation in Connecticut: Prelimi- nary Results on the Use of MTV,” Proceedings of the 8th International Conference on the Bearing Capacity of Roads, Railways, and Airfields, Champaign, Ill., June 29– July 2, 2009. Quality in California, “Stockpile Segregation,” May 24, 2011 [Online]. Available: http://www.qualityincalifornia. com/2011/stock-pile-segregation.html [accessed Sept. 20, 2013]. Rand, D.A., “Thermal Segregation,” Southeastern User Pro- ducer Group Conference, Oklahoma City, Dec. 8, 2010 [Online]. Available: http://www.seaupg.org/PDF/2010/ Wednesday/5%20Thermal%20Segregation_DRand_ TxDOT.pdf [accessed June 27, 2013]. Rand, D.A., “Measuring Pavement Segregation,” TxDOT Construction Division presentation, Austin, 2012 [Online]. Available: http://www.flexiblepavements.org/sites/www. flexiblepavements.org/files/events/conferences/ Measuring%20Pavement%20Segregation.pdf [accessed June 27, 2013]. Rowe, G.M., J.N. Meegoda, A. Jumikis, and M.J. Sharrock, “NJTxtr—A Computer Program Based on LASER to Monitor Asphalt Segregation,” Journal of Construction Engineering and Management, Vol. 130, Nov./Dec. 2004, pp. 924–934. Scherocman, J.A., Segregation: Causes and Cures, J. Scherocman, Consulting Engineer, Cincinnati, Ohio, Oct. 2011 [Online] Available: http://www.oregon.gov/ ODOT/HWY/CONSTRUCTION/manuals/hmac_ inspector_training/14_hmac.pdf [accessed July 9, 2013]. Sebesta, S. and T. Scullion, Infrared Imaging and Ground Penetrating Radar to Detect Segregation in Hot Mix Over- lays, Texas Transportation Institute, Texas A&M, College Station, 2002 [Online]. Available: http://d2dtl5nnlpfr0r. cloudfront.net/tti.tamu.edu/documents/4126-1.pdf [accessed Nov. 26, 2013]. Sebesta, S. and T. Scullion, Performance Monitoring Pave- ments with Thermal Segregation in Texas, Report FHWA/ TX-12/0-6080-1, Texas Transportation Institute, Texas A&M University, College Station, April 2012 [Online]. Available: http://onlinepubs.trb.org/onlinepubs/shrp2/ SHRP2prepubR06C.pdf [accessed Aug. 3, 2013]. Sebesta, S., F. Wang, T. Scullion, and W. Liu, New Infrared and Radar Systems for Detecting Segregation in Hot-Mix Asphalt Construction, Texas Transportation Institute, Texas A&M University, College Station, April 2006 [Online]. Available: http://d2dtl5nnlpfr0r.cloudfront.net/tti.tamu.edu/ documents/0-4577-2.pdf [accessed Oct. 14, 2013]. Sebesta, S., T. Scullion, and T. Saarenketo, Using Infrared and High-Speed Ground-Penetrating Radar for Unifor- mity Measurements of New HMA Layers, SHRP2 Report S2-R06C-RR-1, Transportation Research Board of the National Academies, Washington, D.C., 2013 [Online]. Available: http://onlinepubs.trb.org/onlinepubs/shrp2/SHRP2 prepubR06C.pdf [accessed July 1, 2013]. Song, J., M. Abdelrahman, and E. Asa, Use of a Thermal Camera During Asphalt Pavement Construction, North Dakota State University Department of Civil Engineering Final Report to North Dakota Department of Transporta- tion, Bismarck, Sept. 2009 [Online]. Available: http:// www.dot.nd.gov/divisions/materials/research_project/ ndsu0801final.pdf [accessed July 7, 2013]. Stroup-Gardiner, M. and E.R. Brown, NCHRP Report 441: Segregation in Hot Mix Asphalt Pavements, Transporta- tion Research Board, National Research Council, Wash- ington, D.C., 2000 [Online]. Available: http://onlinepubs. trb.org/onlinepubs/nchrp/nchrp_rpt_441.pdf [accessed Oct. 15, 2013]. Tahmoressi, M., D. Head, T. Saenz, and S. Rebala, Material Transfer Device Showcase in El Paso, Texas, DHT-47, Departmental Research, Texas Department of Transpor- tation, Austin, 1999. Texas Department of Transportation (TxDOT), Test Procedure for Thermal Profile of Hot Mix Asphalt, TxDOT Designa- tion: Tex-244-F, TxDOT, Austin, 2011 [Online]. Available: ftp://ftp.dot.state.tx.us/pub/txdot-info/cst/TMS/200-F_ series/pdfs/bit244.pdf [accessed Jan. 15, 2014]. U.S. Army Corps of Engineers (USCOE), Hot-Mix Asphalt Laydown and Compaction Part III, Report AC150/5370- 14A, Appendix 1, 2001 [Online]. Available: http://www.faa. gov/documentlibrary/media/advisory_circular/150-5370- 14a/150_5370_14a_app1_part_i.pdf [accessed June 27, 2013]. Valdes, G., F. Perez-Jimenez, R. Miro, A. Martinez, and R. Botella, “Experimental Study of Recycled Asphalt Mixtures with High Percentages of Reclaimed Asphalt Pavement (RAP),” Construction and Building Materials, 2011, Vol. 25, pp. 1289–1297. Virginia Department of Transportation (VDOT), Asphalt Field Certification Study Guide, MCS: Asphalt Field

78 Certification School, VDOT and Platinum Performance Partners, LLC, Charlottesville, 2012 [Online] Avail- able: http://www.virginiadot.org/business/matschools. asp [accessed June 28, 2013]. Warren, J., “End of Load Segregation: Identification, Causes, and Cures,” Asphalt Contractors Association of Florida, Tallahassee, 2013 [Online]. Available: http://www.acaf.org/. Williams, M.B., The Effect of Material Transfer Devices on the Texture and Temperature Differentials of Hot Mix Asphalt Concrete, Master thesis, Civil Engineering Department, Auburn University, Auburn, Ala., May 2003. Williams, R.C., G.R. Duncan, and T.D. White, Sources, Measurements, and Effects of Segregation Hot Mix Asphalt Pavement, FHWA/IN/JHRP-96/16, Joint High- way Research Project, Purdue University, West Lafayette, Ind., Dec. 1996 [Online]. Available: http://docs.lib.purdue. edu/cgi/viewcontent.cgi?article=1664&context=jtrp [accessed July 2, 2013]. Willoughby, K.A., et al., Construction-Related Asphalt Con- crete Pavement Temperature Differentials and the Corre- sponding Density Differentials, Report Number WA-RD 476.1, Washington State Transportation Center, University of Washington, Seattle, June 2001 [Online]. Available: http://www.wsdot.wa.gov/research/reports/fullreports/ 476.1.pdfhttp://www.wsdot.wa.gov/research/reports/ fullreports/476.1.pdf [accessed Aug. 19, 2013]. Willoughby, K.A., J.A. Mahoney, L.M. Pierce, J.S. Uhlmeyer, and K.W. Anderson, “Construction-Related Variability in Mat Density Due to Temperature Differentials,” 82nd Annual Meeting of the Transportation Research Board, Washington, D.C., Jan. 12–16, 2003 [Online]. Available: http://www.ltrc.lsu.edu/TRB_82/TRB2003-001535.pdf. Wise, J., “Old Habits Die Hard—Especially in Cape Town,” SABITA Digest, CAPSA 2006 Paper Summary, Sept. 2007 [Online]. Available: www.sabita.co.za/documents/ DIGEST-06.pdf [accessed Nov. 2013]. Wolff, T.F., G.Y. Baladi, and C. Chang, Detecting and Quan- tifying Segregation in Bituminous Pavements and Relating Its Effect to Condition, Pavement Research Center of Excel- lence, Michigan State University, Lansing, 2000 [Online]. Available: http://202.154.59.182/ejournal/files/Application %20of%20digital%20image%20processing%20tech niques%20for%20asphalt%20concrete%20mixture%20 images.pdf [accessed Nov. 12, 2013]. Zelelew, H.M. and A.T. Papagiannakis, “Wavelet-Based Char- acterization of Aggregate Segregation in Asphalt Concrete X-Ray Computed Tomography Images,” International Jour- nal of Pavement Engineering, Vol. 12, No. 6, Dec. 2011, pp. 553–559. Zettler, R., “Longer Life for Your Mat,” Site-K Construc- tion Zone, 2012 [Online]. Available: http://www.site- kconstructionzone.com/?p=8072 [accessed June 27, 2013].

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TRB's National Cooperative Highway Research Program Synthesis 477: Methods and Practices on Reduction and Elimination of Asphalt Mix Segregation provides guidance on how to reduce or eliminate segregation during aggregate production, mix design, asphalt mix production, mix transport and transfer, and placement. The report also explores options for reducing or eliminating segregate, as well as caveats for what not to do are included.

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