44
CONSTRUCTION WORLD
OCTOBER
2014
ROADS AND BRIDGES
“Virtually all of the many potholes
in our roads are on asphalt pave-
ments, essentially due to lack
of maintenance. Concrete roads
do not form as many potholes or ruts, and
require significantly less maintenance than
asphalt roads. Concrete can also be used for
the rehabilitation of asphalt roads, either by
overlaying or inlaying,” Perrie states.
“Research has shown that when
comparing equivalent designs, concrete is
about 10 to 15% more expensive on initial
costs. But concrete lasts much longer than
asphalt with, as mentioned, significantly
reduced maintenance costs, so when a
full life-cycle cost assessment is carried
out concrete roads have a similar or lower
whole-life cost. This means less disruption
to traffic as less maintenance is required,”
he adds.
Perrie says new developments in the
form of Ultra Thin Reinforced Concrete
Pavements (UTRCP) for low volume appli-
cations, and Ultra Thin Continuously Rein-
forced Concrete Pavements (UTCRCP) have
made concrete roads easier and quicker to
construct. “The construction of most of the
concrete inlays on national routes utilising
CRCP has been done with labour-intensive
methods. Concrete lends itself to such job
creation methods, especially for low volume
municipal projects with extensive saving in
maintenance costs.”
The Concrete Institute believes there
is room for the appropriate use of both
concrete and asphalt which can be used
separately, or as composite pavements.
Expertise for world-class
CONCRETE ROADS
South Africa has the
expertise and technology
to design, construct and
maintain concrete roads on
a par with the best in the
world, says Bryan Perrie,
managing director of The
Concrete Institute.
“Most of the many
potholes in our roads are
on asphalt pavements,
essentially due to lack of
maintenance,” says The
Concrete Institute.
Composite roads can be built with concrete
on top of asphalt (as in sections on the N3),
concrete underneath asphalt (some GFIP
projects) or with concrete in heavily traf-
ficked lanes alongside asphalt in the lighter
trafficked lanes (sections on the N3 Town
Hill). The construction equipment for both
materials is available in South Africa.
“As all the materials used in concrete are
sourced locally, concrete road construction
is not dependent on importation constraints
such as recently caused by shortages of
bitumen. Concrete roads, with their long
life and reduced requirement for mainte-
nance, can play a large role in increasing the
sustainability of our roads.”
The Concrete Institute offers training
in the design and construction of concrete
roads and its comprehensive Information
Centre in Midrand, which can be visited in
person or on the web free of charge, houses
a vast amount of literature on the subject.
Concrete roads, with long life and low maintenance, can increase the sustainability of South African roads, says The Concrete Institute.
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