Diapositive 1

1
Practical experiences with SMA Québecs
experience Michel Paradis, P. Eng.,
M.Sc. Transports Québec Laboratoire des
chaussées Canada User Producer Group for
Asphalt CUPGA November 18, 2007 Niagara Falls
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Overview

• Introduction
• Québecs new strategy for choosing interventions
• SMA properties
• Types of SMA in Québec and their uses
• - SMA-10 (with asbestos fibre and shingles)
• - EGM-10
• - EG-10
• SMA granular classes
• Conclusions

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The MTQ road network
2004 data
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Intervention strategy
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SMA - Properties
The high content of crushed coarse aggregates (gt
5 mm) maximizes contact between aggregates.

• Excellent aggregate skeleton

• Optimal distribution of applied loads

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SMA - Properties

• High resistance to rutting
• Good surface texture
• Flexible at low temperatures
• Suitable for thin layers
• Less noise
• No segregation
• Longer service life.

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Granulometric characteristics
SMA
Maximum density line
Densely-graded asphalt mix
Passing
Coarsely-graded asphalt mix
Restricted zone
Control points
Sieve (µm)0.45
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SMA costs

• 20 to 30 more expensive to produce than
  conventional mix
• High asphalt content
• Asbestos fibres
• Production of 0-2.5 mm granular class.

• But.
• Lower thickness of the course
• Longer service life

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Aggregate grading concept

• The LC method of mix design is a combination of
  the SUPERPAVE and LCPC methods.

The MTQ has kept the aggregate grading concept
from the LCPC method.
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Why use the aggregate grading concept?

• The use of aggregate grades facilitates HMA
  design by setting the asphalt content at a high
  level, which ensures long-term performance of the
  mix.
• Standardized designation of a given gradation,
  regardless of the aggregate contractor
• Contractors have standardized and optimized their
  productions.

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Specifications ranges for granular classes
Contractors can produce all MTQ mixes using these
5 granular classes.
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SMA in Québec

• Médiflex
• The first SMA in Québec was used in 1990 on
  Autoroute 20 (approximately 30,000 tons).

Now more than 150,000 tons
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Stone Matrix Asphalt (SMA-10)

• Must be designed using 5-10 mm and 0-2.5 mm
  classes.
• 1.0 asbestos fibre or equivalent.
• Can be used at a thickness of 25 mm, but a prior
  field test is recommended.

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SMA with asbestos
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Autoroute 10 - Sherbrooke
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Route 108 - Estrie
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SMA with shingles
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MTQ standards for using shingles
() The bitumen additive content can be reduced
by 0.08 for every 1 of shingles added to the
mix. This translates to a 40 shingle bitumen
mobilization for a shingle bitumen content of 20.
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10-mm thin coarsely-graded mix (EGM-10)

• Easier to design with 5-10 mm and 0-2.5 mm
  classes, with a small amount of sand (2-8)
  added depending on the granulate used.
• Can be used at a thickness of 30 mm, but a prior
  field test is recommended.

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Route 283 South shore

• EGM-10
• 30-mm thick
• Low asphalt content
• Strong texture
• Resistant to rutting

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10-mm coarsely-graded mix (EG-10)

• SMA derivative.
• Anti-noise coating.

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Conclusions

• 3 types of SMA SMA-10 (for highways and roads
  with high or heavy traffic, preventive
  interventions) EGM-10 (palliative
  interventions) and EG-10 (for highways, casual
  interventions, noise reduction).
• Difficult to convince MTQ territorial branches
  and contractors to use SMA 0-2.5 mm granular
  class is more expensive to produce and uses
  asbestos fibre.

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Conclusions

• Precision placement rapid compacting behind the
  paver, which should not have to stop minimum
  manual labour avoid cold joints.
• Use of the shuttle buggy is recommended.
• Replacement fibre for asbestos.

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Questions?