ASPHALTopics | Fall 2015 | VOL 28 | NO 3

“One of the fastest ways to stimulate
the economy in a downturn is to
build roads.” –Dennis Hunt
Kings Highway 8 in Dundas, Ontario, 1964. (ORBA)
pavements signified a modern and progressive approach
to designing city streets and was embraced by urban
planners across Canada and the U.S.
The introduction of the Superpave Performance
Graded (PG) system in 1993 improved asphalt concrete
specifications, asphalt mixture design and analysis, and
asphalt pavement performance prediction. “The Marshall
Mix Design method didn’t take into account the different
characteristics of bitumen from Alberta, Saskatchewan
and California,” Hunt says. “With Superpave, it didn’t
matter where the asphalt came from; the binder
characteristics were the same. The
characteristics of aggregates were
also considered in the mix design.
The Superpave program proved that
pavements are highly engineered
systems that are tailored to perform
well under specific conditions.”
Checking the grade the old fashioned way (above). GPS
technology revolutionized road grading operations – here
receivers are mounted on a John Deere 872 grader. (ORBA)
In conjunction with more
sophisticated design mixes,
innovative processes have furthered
the industry’s goal of achieving
cost-effective, high performing
pavements. Warm mix asphalt
(WMA) pavements reduce energy
consumption by an average of
10 per cent; they extend the paving
season in northern climates and
WMA provides a longer window
for compacting pavements. The
modernization and automation
of equipment have also made a
tremendous impact on efficiency, ››
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