Road Pavement Forum May 2006

1
Road Pavement ForumMay 2006

• Technical Guideline The use of Modified
  Bituminous Binders in Road Construction (TG 1
  2001)

2
Revision Process

• Identify issues w.r.t current specifications
• Review international specification
• Identify other needs w.r.t guidelines

3
TG 1 Modified Binders
Issues identified w.r.t current specification

• Base bitumen must be SANS 307?
• Ductility _at_ 15o C not necessary?
• Upper limits for Softening Point should be
  specified?
• Change after RTFOT should be and not value?
• Status of Report Only criteria?
• Values for Force Ductility DSR should be
  specified?
• Identify and implement appropriate test to
  measure adhesion?
• Compression Recovery _at_ 4 days relevant?

4
TG1 Modified Binders
Other needs identified w.r.t Guideline

• A selection guideline should be developed?
• A protocol for introducing new types of binders?
• Specifications form part of SANS?
• Asphalt mix design protocols w.r.t modified
  binders?

5
TG1 Modified Binders

• International Review

6
Modified Binders Committee

• Current specifications Europe
• Kobus Louw

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Technical CommitteeCEN/TC 336 Bituminous Binders
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prEN 140232004 (contd)

• The framework covers the following
  characteristics
• Consistency at intermediate service temperature
• Consistency at elevated service temperature
• Cohesion
• Durability of consistency

The cohesion property has been included as a
means of discriminating between PMBs and other
bituminous binders
9
Nomenclature of PMBs
The nomenclature of PMBs comprises the
penetration range and the minimum softening point
and could be declared as follows
PMB 45/80-60
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Framework specifications for essential
requirements and classes of PMBsTable 1
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Framework specifications for technical
requirements and classes of PMBs Table 2
12
Other properties
On a voluntary basis some countries are
evaluating new test methods to gain experience
for further developments. The following methods
are under evaluation

• Bending Beam Rheometer

• Dynamic Shear Rheometer

Deformation Energy by Force Ductility under
different test conditions
The test condition should be selected according
to traffic and climatic conditions or in relation
to the grades used.
13
Australian Specifications for PMBs

• November 2005
• Austroads Project TT1133

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Background

• Revision of May 1997 specifications for PMBs
• Softening point Torsional recovery used as
  quality indicators
• Specification limits based on manufacturing,
  testing and application experienced gained over
  last few years
• Modified emulsions crack sealants not covered
• Publication of Guide to the selection and use of
  PMBs multigrade bitumens

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PMB classification framework

• Binder classes based on application
• S for sealing
• A for asphalt
• followed by 2 digits and predominant polymer
• E for elastomer
• P for plastomer
• R for crumb rubber
• Eg A35P or S10E

16
PMB grades

• Seals
• S10E (48)
• S20E (65)
• S25E (80)
• S35E (48)
• S45R (55)
• S55R (62)
• S15RF (55)
• S18RF (62)

• Asphalt
• A25E (52)
• A35P (60)
• A20E (65)
• A15E (82)
• A10E (88)
• A27RF

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Carl Monismith
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TG1 Conclusions

• Critical assessment of the current guideline
  indicates some amendments/additions may be
  appropriate
• Development of specifications for modified
  binders internationally is a very dynamic process
• Task team committed to produce revised TG1
  document by May 2007!!