Greening the Blacktop

1. Going Green with Sustainable Asphalt RAP, Recycling, Energy and the Carbon Footprint Greening the Blacktop

2. Overview • Why Asphalt is sustainable • Perpetual Pavements • Carbon Footprint • RAP & Recycling • Warm Mix Asphalt • Porous Asphalt • Energy & Emission Reductions

3. Why Asphalt is Sustainable

4. Sustainable Pavements

5. Sustainable Pavement • Durability… • Asphalt is the Perpetual Pavement • Road itself doesn’t wear out • Simple, fast maintenance • Reclaimed…is then reused • Total removal/reconstruction not needed

6. Sustainable Pavement • Requires less energy to construct an asphalt pavement • Per ASCE…20% less • Less energy consumed by public • Less maintenance keeps traffic moving

7. Perpetual Pavements } 40-75 mm STONE MATRIX ASPHALT, OGFC or Superpave 100 mm to 150 mm Zone Of High Compression High Modulus Rut Resistant Material (Varies As Needed) Flexible Fatigue Resistant Material 75 - 100 mm Max Tensile Strain Pavement Foundation

8. Rehabilitation • Possible Distresses • Top-Down Fatigue • Thermal Cracking • Raveling • Solutions • Mill & Fill • Thin Overlay Mill Surface – Use for RAP { High Quality Stone Matrix, OGFC or Superpave 50 - 100 mm 20+ Years Later Structure Remains Intact

9. Carbon Footprint

10. What the heck is a Carbon Footprint?

11. A carbon footprintis defined as: The total amount of greenhouse gases produced to directly and indirectly support human activities, usually expressed in equivalent tons of (CO2) Doesn’t segregate GHGs Environmental Sustainability

12. Climate Registries • Organizations that collect and compile emissions data generally voluntary (CA, NE US) • Encourages voluntary early actions to increase energy efficiency and decrease GHG emissions

13. What is a Greenhouse Gas? • Gases that trap heat in the atmosphere – Allows us to live here • Some occur from nature, others from anthropogenic activities

14. What is a Greenhouse Gas? • Principal greenhouse gases entering the atmosphere from human activities are: • Carbon dioxide (CO2) • Methane (CH4) • Nitrous Oxides (N2O) • Fluorinated gases (HFCs & PFCs)

15. Regulatory Concerns • Efforts to make you report emissions • Benefits of being ahead of the wave • Demonstrates concern for the public and the environment

16. Opportunities to Reduce Emissions • Sustainable Pavements • Warm Mix • RAP • Plant O & M • Truck and other equipment maintenance

17. RAP & Recycling

18. Recyclability • Asphalt is the No. 1 recycled material • Biggest Re-user • 1995 FHWA Report to congress • 90 Million tons reclaimed • 80% recycled • 2006 Contractor Survey • ~69% reused in HMA • ~27% other recycling • <3% discarded

19. Why Recycle RAP into HMA? • Best and Highest use • Reduces demand for new materials • Reduces carbon footprint • Contains valuable materials • Aggregate ~95% >$10/ton • Asphalt ~5% > $400/ton • Value >$29.50/ton (minus processing)

20. Shingles • Shingles • Materials used in HMA • >20% asphalt binder • Fibers • Sand • Usually 5% of mix • Saves 1% binder > $6.00/ ton of HMA/WMA • Tear-offs

21. Over the past two years, MoDOT has allowed contractors to put used shingles that have been removed from rooftops into their asphalt mix. The result is a very durable, more-rut resistant asphalt at a much lower price. The use of recycled shingles saves $3 to $5 per ton of asphalt. That may not sound like much at first, but consider this: a typical resurfacing project would use about 30,000 tons of asphalt, for a savings of $90,000 to $150,000.

22. Other Recycled Materials Crumb rubber (from tires) Steel slag Glass

23. Warm Mix Classifications

24. Lower Temperature Advantages • Lower energy consumption (≈30%) • Lower plant wear • Decreased binder aging • Early site opening – Return to user • Cool weather paving • Compaction aid for stiff mixes • Cooler working conditions

25. Porous Asphalt

26. What are Porous Pavements? Open-Graded HMA/WMA ~ 2 ½” ½” Agg. (#57) ~ 1” – 2” Thick Clean Uniformly Graded 2”-3” Crushed Agg. (#2) – 40% Voids Non-Woven Geotextile Uncompacted Subgrade

27. Porous Pavement • Stormwater quality improved with: • Porous pavement, and • Open Grade Friction Course • Can eliminate the need for stormwater structures

28. Water Quality

29. Walden Pond 1977 1997 Report: “Twenty years later, a long time for one paving job on that busy parking lot, it still looks good and works well.” 2008

30. Energy & Emission Reductions

31. Warm Mix • Will dominate the market in < 5 years • Reduced energy consumption • Reduced emissions • No hazardous fumes/worker exposure • Plants compatible in congested areas • No odors The sooner the better!

32. Remedial Efforts • Use the components of the carbon footprint to identify problem areas • Take action and make adjustments to reduce emissions • Switch to Warm Mix sooner • Conduct energy audits • Take action to reduce energy

33. Energy Use by Road Material Type Colas Group Data

34. Reduced Energy Consumption • Energy Audits • DOE Software • Use RAP • Warm Mix Can Reduce Energy by Cover the Aggregate ⅓

35. Why is Asphalt Sustainable • 100% Recyclable • Can use other recycled materials • Low carbon footprint pavement • Long life & fast resurfacing • Warm-Mix Asphalt • Porous pavement for stormwater

36. NAPA Theme RAP + Porous+ Warm Mix + Perpetual Pavements = Sustainability

37. Summary & Review • Why Asphalt is sustainable • Perpetual Pavements • Carbon Footprint • RAP & Recycling • Warm Mix Asphalt • Porous Asphalt • Energy & Emission Reductions

38. Questions?