Surface Mix Experience and Performance City of Edmonton

1. Surface Mix Experience and PerformanceCity of Edmonton Hugh Donovan, P.Eng. Construction Services Engineer Transportation Department City of Edmonton 2006 CUPGA Meeting Charlottown, P.E.I.

2. CITY OF EDMONTON ROADWAY 2007-2011 CONSTRUCTION BUDGET

3. Estimated Aggregate Reserves: • 1978 aggregate reserves 6,980 Million tonnes; • 2,235 Million tonnes of Gravel • 4,745 Million tonnes of Sand • Gravel Sized Materials; • 1,036 Million tonnes of Concrete Aggregate • 1,199 Million tonnes of Asphalt Aggregate • Sand Sized Materials; • 2,241 Million tonnes of Dune Sand • 200 Million tonnes potential Street Sand • 2,304 Million tonnes Other sand materials

4. 1978 • Only 95 Million tonnes of Aggregate both Sand and Gravel had actually been confirmed in 1978 2006 • By the end of the 2006 construction season it has been estimated that we will have used an additional 432 Million tonnes of sand and gravel in the Edmonton region; • By 2026 given current growth we estimate that we will have used an additional 500 to 650 Million tonnes of sand and gravel in the Edmonton region

5. Aggregate Supply Issues: • Current Aggregate Sources: • Are of poorer quality; • Have smaller rock fraction maximum size; • More costly to process; • Secondary processing to remove deleterious materials; • Further aggregate haul distances

6. Aggregate Supply Issues: • Pit Logistics: • In 1978 aggregate materials came from pits located along the North Saskatchewan River in close proximity of the City (<10km); • In 2006 aggregate materials are coming from pits located well outside the City such as Wabamum, Villenuve, Onoway, Camrose, Smoky Lake and Ponoka. These pit can be as far away as 60-135km; • In 2005 and 2006 our premium aggregates is coming from as far away as Whitcourt, Nordeg and Rocky Mountain House some 220 to 270 km from Edmonton

7. Other Issues • In 2005 we had a cement shortage, resulting delays in project completions; • Also in 2005 the Independent truckers went on strike – Net result was an increase in trucking costs, increase in project costs and delays in project completion; • In 2006 we had an Asphalt Cement shortage, resulting in project delays; • Manpower issues, with the hot construction market in Alberta it is becoming much more difficult to attract workers;

8. GENERAL ROAD STRUCTURES IN EDMONTON Granular/ Soil Cement (63% of Network) Deep Strength Asphalt or Oil Mix ( 10% of Network) Composite Pavement ( 27% of Network) 50 - 250mm Hot Mix Asphalt 100-150 mm Hot Mix Asphalt 200-300mm Hot Mix Asphalt or Oil Mix 150 - 300mm Granular Base or Soil Cement Base 150-200mm Portland Cement Concrete

9. Historical Overview of Asphalt Mixes

10. Specialty Mix Initiatives: Since the mid 1970’s, the City of Edmonton has been involved with trials utilizing a variety of Hot Mix Asphalt specialty mixes: • Asphadur (1980 & 1981); • Sulphur-Modified Asphalt (1981); • Polymer Modified Binders (1986 – Present); • Stone Mastic Asphalt [SMA] (2000-Present); • Asphalt Rubber (1976, 2002-Present); • Superpave (1999, 2001-2002);

11. Polymer Modified Binder Usage

12. SMA, Stone Mastic Asphalt • SMA 16mm, 50 Blow Marshall Surface Mix (Overlay and Surface Mix on Higher Traffic Volume Roadways)

13. Advantages/Disadvantages • Advantages of SMA: • SMA provides durable, and rut resistant wearing course; • Mix surface texture characteristics are such that noise generated by traffic is lower than dense graded mixes (measured at 4 decibels quieter); • Can be placed and compacted with conventional paving and rolling equipment; • May provide reduced reflective cracking from underlying cracked pavements due to the flexible mastic. • Disadvantages of SMA: • Aggregate costs, bringing in high quality aggregate from Whitecourt, Nordeg and Rocky Mountain House; • Higher Binder costs with the use of the polymer modified binders;

14. Yellowhead Trail East of 50 Street (2006)

15. 66 Street & Yellowhead Trail (2004)

17. Rutting Performance

18. Asphalt Rubber Asphalt rubber mix is a gap graded 12.5mm, 75 blow Marshall surface asphalt mix containing 18% crumb rubber particles and 82% AC 80-100

19. Advantages/Disadvantages • Advantages of Asphalt Rubber: • Asphalt Rubber provides a textured and rut resistant wearing course; • Surface texture characteristics are such that noise generated by traffic is lower than dense graded mixes 4-8 decibel reduction depending on the roadway; • Can be placed and compacted with conventional paving and rolling equipment; • Disadvantages of Asphalt Rubber: • Aggregate costs, aggregate processing is similar to an SMA mix resulting in additional processing; • Higher Binder costs due to the increase quantity of binder required in the mix and blending equipment; • Cost of Crumb rubber component; • Surface of mix requires a solution of lime water to be applied prior to trafficking

20. Stony Plain Road (2003)

21. 50 Street South of 13 Avenue (2003)

22. 153 Avenue East of 66 Street (2006)

23. Superpave Our Superpave mix is a 12.5mm Superpave Course surface asphalt mix with a PG 58-34 binder with a design traffic loading of <3X106 ESAL's.

24. Advantages/Disadvantages • Advantages of Superpave: • Mix is designed for anticipated traffic loadings; • Longer pavement life, with less fatigue and thermal cracking, • Can be placed and compacted with conventional paving and rolling equipment; • Disadvantages of Superpave: • Aggregate costs, additional aggregate processing results in additional costs; • Additional mix costs due to PG testing of Binder; • Some difficulty in placement of mix due to mix tenderness

25. Winterburn Interchange on Yellowhead Trail (2002)

26. Other Initiatives • Full Depth Reclamation using Foamed Asphalt • Infrared Thermography Studies • Use of Ground Penetrating Radar for structural evaluation of roadway structures

27. Full Depth Reclamation Utilizing Foamed Asphalt

28. Advantages of Full Depth Reclamation with Foamed Asphalt • Reuse of the material in the existing pavement generally better quality materials than are currently available. • Derive maximum benefit of existing pavement structure as a stabilized base course material • Simultaneous addition of “make-up (granular)” material and/or stabilizing agent(s) • Speed of construction - one or two pass operation vs. a multi-pass operation • Accommodation of traffic - roadway is never closed to traffic • Economics ($) 30 to 50% saving

29. 150 Avenue East of 94 Street (2001) 12/10/2006 12/10/2006

30. Ellerslie Road ~ 50 Street (2003) 12/10/2006

31. 150 Avenue Deflection Performance 150 Avenue, 87 Street to 94 Street 3.5 3.3 3.0 2.8 2.5 2.3 2.0 1.8 Deflection (mils) 1.5 1.3 1.0 0.8 0.5 0.3 0.0 0+000 0+040 0+090 0+140 0+190 0+240 0+290 0+340 0+390 0+440 0+490 0+540 0+590 0+640 0+690 0+740 0+790 0+840 Station May-06 Pre - 2001 Post - 2001 Aug -02 May-05

32. Infrared Thermography • cold spots = thermal segregation results in poor performance

33. Ground Penetrating Radar Asphalt on Soil Cement Base Asphalt on Concrete on Granular Base Asphalt on Soil Cement Base

34. Where Do We Go From Here? • Trial project utilizing warm asphalt technology; • Cold-in-Place Recycling of existing road structures; • Study on our current Hot-Mix Asphalt mixes with respect to the incorporation of RAP