02 John Berti CUPGA Western Canada Presentation

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02 John Berti CUPGA Western Canada Presentation Powered By Docstoc
					                CUPGA 2008
                      Western Canada
                       Perspective on
           State – of - the Canadian Technology
                 Challenges and Solutions



John Berti, P. Eng.
bertij@huskyenergy.com
       Western Canada (WCAN)
   Conservative approach to the adoption of the
    Superpave system wrt to asphalt binder
    specifications and mixture design and analysis
    system
    – Marshall method is still the preferred system of choice
      including traditional pen/viscosity graded binders
   Dense fine graded mixtures are most widely
    specified
    – Minimal percentages of RAP are allowed in most mixes
   Very little use of SMA’s for high performance
    pavements
    Superpave Performance Grade
              Binders

   “Straight run” asphalts

    – WCAN Continues to Use Penetration grades
        (based   on CGSB Pen-Viscosity system)


    – PG grades are never or rarely specified
        Small   amounts of PG58-31
    Superpave Performance Grade
              Binders
   Modified Asphalts – (PG = modified)
    – Almost all modified demand uses PG specs
    – Approx. 7 different grades (from PG76-28 to
      PG58-37)
    – more commonly used in high service
      applications (traffic intersections and slow /
      high truck volume applications, new
      construction)
    – Alberta biggest user, Sask/Man lowest
    – No “PG plus” specs but AASHTO M320 Table 2
      is occasionally specified
    – Alternative bids with life cycle cost adjusts
      sometimes used (ie 150/200A or PG 58-34)
  Superpave Performance Grade
            Binders

 Usage of PG grades has been
 increasing slightly
  – Approx 6% of paving asphalts in
    Western Canada are specified using PG
    specifications
  – P3’s are a big factor – contractors
    making the decision
  Superpave Performance Grade
            Binders
 Issues   & Challenges
  – Concerns about allowing lower
    performing grades
  – Concerns about available grade
    selection

 Future   changes
  – No switching to PG for straight runs in
    near term
  – BC – increased use of PG 70-22
         Superpave Mixes
 Used occasionally in BC (Vancouver area)
  (improved rut resistance) but minimal
  usage in other WCAN provinces
 In the past many Alberta highway projects
  used Superpave mix specifications but
  usage today has dropped
 Overall estimate less than 10% of Western
  Canada mixes are using Superpave mix
  specifications.
           Superpave Mixes
 Issues   & Challenges
  – High aggregate costs and greater pit
    depletion
  – AB - Concerns about poorer
    performance especially with coarser
    mixes


 Nobig changes expected in the near
 term
         Stone Mastic Asphalts
 City of Edmonton has had extensive
  experience and use as a regular part
  of their program. Usage is expected
  to increase slightly.
 Other jurisdictions (Alberta and BC)
  have done some SMA trials or
  projects and others (Sask/Man.)
  have not.
         Stone Mastic Asphalts
   Issues & Challenges
    – Edm - Availability of zero grind (mineral filler)
    – High Quality aggregates expensive to import,
      mix design, AC drain down, getting good lay
      down


   Future changes
    – Other than Edm. usage of SMA is expected to
      stay about the same
    – Edm. using cement to replace zero grind
    – Edm. looking at smaller max. size aggregate
                 Other Activities
   Warm mix
    – Many jurisdictions are doing warm mix trials and a
      number of different technologies have been used

   Rubber Crumb
    – Used extensively throughout Alberta over last 5 years
      but a number of agency’s have expressed performance
      concerns
    – Usage in Alberta in future is questionable
    – Trials have been done in BC and Sask as well.

   Other emerging technologies over the last 5
    years include:
    – Ultra thin lift overlays, foamed asphalt stabilized base
      course, recycled asphalt shingles
Thank You !

				
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posted:9/14/2012
language:English
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