Construction World October 2016

38 / 56

36
ROADS AND BRIDGES
placement of the UTFC. Ongoing commu-
nication enabled the companies to bolster
their teams to ensure that the construction
programme remained on track.
These mitigating efforts were definitely
worth it, considering that, by mid-July, the
company had already completed 81% of its
component of the project, and had not yet
recorded one asphalt failure.
“The project relies heavily on achieving
a repetitive rate on the construction
site. Because it is a large contract, small
problems, such as those encountered at
the asphalt plant, can become very large
challenges,” says Koch.
High rideability specification
The high rideability specification requires
careful application of the BTB and UTFC.
Two 60 mm layers of BTB are placed sepa-
rately and individually inspected to ensure the
final layer meets the tight 10,5 International
LEFT: Roadmac Surfacing is ahead of schedule and the project will be completed before deadline.
RIGHT: Roadmac Surfacing’s component of the project focuses on the surfacing aspects of the project.
Roughness Index (IRI) requirements.
Uneven sections are milled out using a
planer. Koch says the machine is equipped
with eight sensors to accurately detect
uneven surfaces. These sensors also help
guide the machine in removing on average
0,6 mm of BTB with its drum that is equipped
with 750 teeth.
“The accuracy of the final layer of the
BTB is critical, as it will influence the layer
of UTFC that is placed on top of it, and if not
100% could compromise the high rideability
specification demanded by SANRAL,” he says.
A very high specification UTFC is being
used on this project. It is a proprietary
product of National Asphalt that carries
a three year warranty, and is known for
reducing rutting, minimising spray in
rainy seasons and providing a very high
skid resistance.
Roadmac Surfacing and Raubex are
working hard to ensure that their road
projects point to the quality that is associ-
ated with the skills deployed from Kenneth
Kaunda Road Extension, Cleveley, and is
adopted throughout the country and across
its borders. This project is no exception and
is certainly on its way to becoming a flagship
project in the group’s impressive portfolio.