Sustainable road maintenance strategies

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Sustainable road maintenance strategies

  1. 1. Sustainable Road Maintenance Dragos Andrei, Ph.D., P.E., M.ASCE 45th Annual MSA Conference September 2013
  2. 2. About Dragos • Associate Professor, Civil Engineering, California State Polytechnic University • Previous experience with Fugro and MACTEC • P.E. California, Texas • Ph.D. Arizona State University, M.S. University of Maryland • Director, Pavement Recycling and Reclaiming Center at Cal Poly Pomona • Principal Engineer and Partner, West Coast Engineering Consultants
  3. 3. Outline • State of the Pavement • Sustainability and Sustainable Roads • “Green” Asphalt Maintenance/Rehabilitation Strategies • “Green” Strategies for Concrete and Other Pavements • Implementation of Sustainable Maintenance Strategies
  4. 4. Section 1 STATE OF THE PAVEMENT
  5. 5. Source: California Local Streets and Roads Needs Assessment, January 2013, http://www.savecaliforniastreets.org/
  6. 6. 2011: Source: Caltrans State of the Pavement 2011, http://www.dot.ca.gov/hq/ maint/Pavement/Pavement_Progr am/PDF/2011_SOP.pdf 2007:
  7. 7. Bottom Line • We inherited a vast road network: ~ 50,000 lane miles state roads ~ 200,000 lane miles local roads • More than 50% of these pavements are “at risk” • For local roads, the funding available for maintenance and rehabilitation is less than half the funding required to maintain the current condition. • Traffic (demand) will continue to increase • $$$ Needs will continue to increase
  8. 8. How Did We Get Here? • Build, build, build … but how about the future? – Don’t think about the future, enjoy the present … • Who will maintain these pavements? – Not my problem … I will be retired by then • Who will pay for this? – Don’t worry, THEY will find money, things will never change … • How are THEY going to rebuild these pavements? – Don’t worry, there’s plenty of oil, cement, aggregate …
  9. 9. Section 2 SUSTAINABILITY AND SUSTAINABLE ROADS
  10. 10. Sustainability Paradigm
  11. 11. Sustainable Roads: Key Features • • • • • • • • • Durability Low maintenance Low emissions/energy Recyclable Permeable Cool Smooth Quiet Complete, aesthetically pleasing.
  12. 12. Pavement Condition Index (PCI) VERY GOOD GOOD FAIR POOR M&R Immediate Effect Without M&R, Pavements Will Fail … Life Extension due to M&R Original Service Life VERY POOR M&R Effect Do Nothing Curve Time/Traffic
  13. 13. Long-Life, Low-Maintenance Roads
  14. 14. Low-Emissions/Energy Construction and Maintenance • Energy = fuel consumption = fossil fuels = emissions • Greenhouse Gases (GHG): water vapor, carbon dioxide, methane, nitrous oxide, ozone, CFC, other • Carbon Footprint: measure of carbon dioxide and methane emissions expressed in CO2e (carbon dioxide equivalent for 100 years global warming potential)
  15. 15. Source: The Environmental Road of the Future, Colas 2003
  16. 16. Carbon Footprint Categories: • “Cold” M&R strategies: emulsion-based seals, cold recycling, full-depth reclamation, soil stabilization, etc. • “Warm”: warm mix asphalt, maintenance treatments with warm mix additive, etc. • “Hot”: hot in-place recycling, hot mix asphalt, etc. • “Big Foot”: portland cement concrete (due to the manufacturing of cement and steel)
  17. 17. Road Recycling - Asphalt Store for later use in: Hot Mix Asphalt (HMA) Warm Mix Asphalt (WMA) Crushed Miscellaneous Base (CMB) Hot In-Place Recycling (HIR) Cold In-Place Recycling (CIR) Cold Central Plant Recycling (CCPR) Full Depth Reclamation (FDR)
  18. 18. Road Recycling – Portland Cement Concrete Store for later use in: Portland Cement Concrete (PCC) Hot Mix Asphalt (HMA) Crushed Miscellaneous Base (CMB) Rubblization: Break and Seat Crack and Seat
  19. 19. RAP, RCA Management • Both concrete and asphalt are 100% recyclable • Avoid contamination of RAP/RCA stockpiles by using good management practices: – Use single-source stockpiles – Separate stockpiles by size (fractionating) – Ensure drainage and cover stockpiles to prevent excessive moisture – Use low slope to prevent segregation • More information: http://www.morerap.us/ http://www.fhwa.dot.gov/pavement/recycling/rca.cfm
  20. 20. Recyclable Import • • • • • • RAS: Recycled Asphalt Shingles Crumb Rubber from Waste Tires Blast Furnace Slag Coal Ash Silica Fume Others
  21. 21. Permeable Pavements • Reduce stormwater runoff • Filter pollutants from water • Permeable pavements are also “cool” pavements when wet! • More information: – Pervious concrete: http://www.perviouspavement.org/ – Porous asphalt: http://www.asphaltpavement.org/index.php?option=com_content&view= article&id=359&Itemid=863 – Permeable pavers: http://www.icpi.org/permeable
  22. 22. Source: A permeable paver demonstration, Austin's Ferry, Tasmania, Australia, J.J. Harrison, 2011
  23. 23. Cool Pavements • Reduce the “heat island” effect by: – Shading – Increasing Solar Reflectance (Albedo) • Painting/Coating low albedo materials • Use high albedo materials • Apply thin maintenance treatments with high albedo materials: e.g. microsurfacing and whitetopping – Increasing Thermal Emittance • Use permeable pavements, water retentive pavements – More Info: http://www.epa.gov/heatisland/mitigation/pavements.htm
  24. 24. Quiet Pavements • Reduce the tire-pavement noise • Methods: – Open-graded friction course asphalt (+ rubber) – Diamond grinding concrete pavements – Noise barriers, sound walls – Lowered alignment • Challenges: – Texture wears off with time and needs maintenance/replacement
  25. 25. Source: Washington DOT Quieter Pavement Research, http://www.wsdot.wa.gov/Business/materialslab/quieterpavement
  26. 26. Complete Streets Source: Complete Streets, http://www.smartgrowthamerica.org/completestreets/complete-streets-fundamentals/complete-streets-faq
  27. 27. Section 3 ASPHALT RECYCLING IN-PLACE
  28. 28. In-Place Asphalt Recycling Techniques •Milling •Micro Milling •Surface Recycling (Resurfacing) •Remixing •Repaving •Cold In-Place Recycling (CIR) •Cold Central Plant Recycling (CCPR) •Pulverization •Mechanical Stabilization •Bituminous Stabilization •Chemical Stabilization
  29. 29. Cold Planing/Milling Process
  30. 30. Cold Planing Applications • Remove existing asphalt concrete surface before overlay or for cold recycling (in-place or central plant) • Correction of longitudinal profile and crossslopes • Restore pavement smoothness or help achieve better smoothness upon resurfacing • Restore surface friction (micro-milling)
  31. 31. CP Pattern Comparison • Tool spacing and pattern, drum speed and advance rate, will influence the final milled pattern: Source: Milling for Smoothness, Eric Baker, Roadtec 2013, http://www.arra.org/index.php?option=com_docman&task=doc_download&gid=510&Itemid=157
  32. 32. CP Equipment
  33. 33. CP Project Selection Pavement Condition Index (PCI) VERY GOOD FAIR Cold Planing POOR Hot In-Place Recycling GOOD Cold Recycling Full Depth Reclamation VERY POOR Time/Traffic
  34. 34. More CP Resources • Basic Asphalt Recycling Manual, ARRA and FHWA, Second Edition: expected January 2014 • Asphalt Recycling and Reclaiming Association, http://www.arra.org/presentatio ns/cold_planing.pdf
  35. 35. Hot In-Place Recycling (HIR): Remixing
  36. 36. Hot In-Place Recycling (HIR): Repaving
  37. 37. HIR Methods • Recycling: add rejuvenating agent, no additive • Remixing: add rejuvenating agent and additive: – Virgin aggregate – Asphalt cement – Plant mix HMA • Repaving: remixing + HMA overlay • Stages: – Single: up to 2 inch depth – Multiple: up to 3 inch depth
  38. 38. HIR Applications • Purpose: rejuvenate/renew/improve the asphalt concrete surface, up to 2-3 inches deep • Use to address raveling, weathering, bleeding, other types of distress confined to the pavement surface. • Will not mitigate structural problems • Can be covered with chip seal or other thin maintenance treatment
  39. 39. HIR Equipment • • • • Heating units Milling/Scarifying unit Drying/Mixing unit Paver • Rollers • Rejuvenating Agent • Admixture truck Source: Martec, http://martec.ca/2010/11/november-2010-ar2000-super-recycler-at-tradeshow/
  40. 40. HIR Train Source: Brian Hansen, Dustrol, Inc.
  41. 41. HIR Equipment
  42. 42. HIR Project Selection Pavement Condition Index (PCI) VERY GOOD FAIR Cold Planing POOR Hot In-Place Recycling GOOD Cold Recycling Full Depth Reclamation VERY POOR Time/Traffic
  43. 43. More HIR Resources • Basic Asphalt Recycling Manual, ARRA and FHWA, Second Edition: expected January 2014 • Construction Inspection Checklist #11 Hot In-Place Asphalt Recycling Application, FP2 and FHWA http://www.fhwa.dot.gov/pavement/preservation/ppcl00.cfm a second edition of this checklist is available in print and will soon be available online. • Caltrans Maintenance Technical Advisory Guide (MTAG) Volume I Flexible Pavement Preservation Second Edition, Chapter 13: InPlace Recycling, http://www.dot.ca.gov/hq/maint/MTA_GuideVolume1Fl exible.html • Hot In Place Asphalt Recycling, Brian Hansen, Dustrol, Inc., http://www.savemyroad.com/cir_hir/files/Ho t-In-Place-Asphalt-Recycling.pdf
  44. 44. HIR Construction Checklist Contents • • • • Document Review Project Review Materials Checks Preconstruction Meeting • Pavement Preparation • Equipment Inspections • • • • • • Weather Requirements Mix Design Traffic Control Project Inspection Opening to Traffic Common Problems and Solutions
  45. 45. Cold In-Place Recycling (CIR)
  46. 46. CIR Applications • Restore the structural integrity of the top 2-4 inches of the asphalt concrete • Cover with HMA overlay or thin maintenance treatment • Effective in treating distress confined to the pavement surface as well as thermal cracking. • CIR is generally softer than HMA and may delay reflective cracking.
  47. 47. CIR Equipment • • • • • • Tankers Milling machine(s) Crushing and screening units Mixer Paver Rollers
  48. 48. Cold Central Plant Recycling (CCPR)
  49. 49. CIR Project Selection Pavement Condition Index (PCI) VERY GOOD FAIR Cold Planing POOR Hot In-Place Recycling GOOD Cold Recycling Full Depth Reclamation VERY POOR Time/Traffic
  50. 50. More CIR Resources • Basic Asphalt Recycling Manual, ARRA and FHWA, Second Edition: expected January 2014 • Construction Inspection Checklist #12 Cold In-Place Asphalt Recycling Application, FP2 and FHWA http://www.fhwa.dot.gov/pavement/preservation/ppcl 00.cfm a second edition of this checklist is under final review by ARRA and FHWA. • Caltrans Maintenance Technical Advisory Guide (MTAG) Volume I - Flexible Pavement Preservation Second Edition, Chapter 13: In-Place Recycling, http://www.dot.ca.gov/hq/maint/MTA_Guid eVolume1Flexible.html
  51. 51. Full Depth Reclamation (FDR)
  52. 52. FDR Methods • Pulverization • Stabilization – Mechanical = with aggregate or RAP – Bituminous = with emulsified or foamed asphalt – Chemical = with cement or other pozzolanic materials • No. of Passes: – Single pass – Multiple pass
  53. 53. FDR Application • Restore the structural integrity of the pavement over the entire treated depth • Produce a uniform, stabilized, crack-free material by mixing asphalt concrete with underlying materials • Cover with thin maintenance treatment, asphalt concrete or other surfacing material.
  54. 54. FDR Equipment
  55. 55. FDR with Emulsified Asphalt
  56. 56. Grading and Compaction
  57. 57. FDR Project Selection Pavement Condition Index (PCI) VERY GOOD FAIR Cold Planing POOR Hot In-Place Recycling GOOD Cold Recycling Full Depth Reclamation VERY POOR Time/Traffic
  58. 58. More FDR Resources • Basic Asphalt Recycling Manual, ARRA and FHWA, Second Edition: expected January 2014 • FDR Construction Checklist, PRRC – FHWA ARRA available in print, it will be soon available online • Full Depth Reclamation, ARRA: http://www.arra.org/presentations/fulldepth_reclamation.pdf
  59. 59. Section 4 IMPLEMENTATION
  60. 60. Green Up! • Use a pavement management system – Include sustainable maintenance and rehabilitation strategies in the PMS (see article in August 2013 APWA Reporter) – Keep the PMS data up to date • Add or include a pavement preservation program – Define pavement preservation triggers/criteria – Establish default frequency for preservation treatments
  61. 61. Green Up! • Manage your resources better: – Even when damaged, pavements have value: aggregate, asphalt, cement, steel, etc. – Use RAP/RCA best management practices – Reuse materials as much as possible • Require minimum three design/rehabilitation alternatives for each project of which at least one should specifically address sustainability
  62. 62. Green Up! • Don’t forget the 4 R’s: Right treatment, Right pavement, Right time, Right contractor. • Learn more about sustainability and green rating systems for pavements: – LEED/Green Building Council – Greenroads – Invest – Green Up
  63. 63. “Green Up” • Software application to compare pavement rehabilitation alternatives in terms of sustainability; not a rating system; • Under development at Cal Poly Pomona; • Includes: – Materials – Technologies – Surface Properties – Life vs. Cost Analysis
  64. 64. Green Up: Materials
  65. 65. Green Up: Technologies
  66. 66. Green Up: Surface Properties and Life/Cost
  67. 67. Green Up: Alternative Comparison Mill and Fill Mill, CIR and Overlay
  68. 68. Thank you Dragos Andrei, Ph.D., P.E., M.ASCE Associate Professor, Civil Engineering Director, Pavement Recycling and Reclaiming Center CAL POLY POMONA dandrei@prrcenter.org www.PRRCenter.org

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