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CONSTRUCTION WORLD
JANUARY
2017
storage tank of an asphalt plant, which
can obstruct binder supply to the
measuring tank.
• Asphalt mixtures may vary in
performance.
• Hauling the blended product almost
400 km from Bituguard to Much Asphalt’s
plant was a logistical challenge.
All of these potential issues were
successfully overcome and Bituguard’s
good track record on storage stable product
and was proven again during this project.
SBS modified bitumen
SBS is a co-polymer of styrene and
butadiene. “When added to asphalt,
SBS polymers significantly enhance the
performance and longevity of the asphalt,”
says explains Bituguard Southern Africa
plant manager Caroline Marais.
“The strong, three-dimensional network
of polymers is impervious to natural
extremes of heat and cold. SBS also has
excellent aging characteristics. It is not
brittle in cold weather and maintains its
integrity in hot weather.”
The race circuit was completed without
any failures and Weideman believes the
consistency in all raw materials made it
possible to produce an asphalt mix that
conformed to all international standards.
Hercu du Preez, pavement engineer at
WSP Parsons Brinckerhoff, adds that a
shuttle buggy was used for all asphalt when
paving the track to maintain the integrity
of the asphalt mix and achieve the highest
possible level of riding quality.
A longitudinal indirect joint heater was
also used to improve the longitudinal joints.
The mix for all non-raceway areas
was produced using a 50/70 binder in a
Colto Medium design using the specified
percentage RA from the milled asphalt on
site with great success. Sapref was the
bitumen supplier.
Surfacing of parking areas.