DIGEST 2006 - Sabita

Revision of Technical Guideline 1 (TG 1):
The use of modified binders in
road construction in SA
Dennis Rossmann
Materials and Pavement Engineer
SANRAL, Eastern Region
The publication in 2001 of
the Asphalt Academy’s
(AsAc) TG 1 – Technical
Guidelines: The use of
modified binders in road
construction, was a major step
forward in providing a single
generic industry guideline
covering the use of modified
binders in South Africa.
The introduction of generic binder
classes, which are “polymer blind”
but required to conform to end
product property limits appropriate
to the specific application, were
viewed by many practitioners at
the time as being fairly “radical”.
However, over time these generic
classes have steadily gained
acceptance to a point where
specifiers, producers and users
now generally feel entirely
comfortable with the system.
Review
Over and above normal good
practice of reviewing technical
guidelines approximately every
five years, the field of bitumen
modification is internationally a
very dynamic one. As a result, at
the November 2005 meeting of
the Road Pavements Forum a
resolution was passed to
reconvene the task group to
review the 2001 edition of TG 1.
This reconvened group consists of
many who where members of the
original task group, with
representation from road
authorities, researchers,
consulting engineers and
contractors, as well as both
primary and secondary binder
producers. AsAc is fulfilling the
role of secretariat.
The initial phase of the project
consisted of critically reviewing the
following issues:
• Applicability of current binder
classes;
• Guidelines with respect to
selection criteria;
• Appropriateness of current
test protocols;
• Appropriateness of current
test limits;
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