international
construction
november 2013
ROAD BUILDING
34
Technological advantages
UMB Spedition used two Vögele pavers for the asphalt paving
work, a Vögele Super 1900-2 with AB 600-2 TV screed with a
pave width of 7.5 m, and a Vögele Super 2100-2 equipped with
the same screed, but extended to a maximum pave width of 9 m.
The first asphalt layer was levelled with the aid of Vögele
Niveltronic Plus. This automatic grade and slope control system
allows the grade to be controlled across the entire section by
tracking a specific reference.
A Big-MultiPlex Ski was also used for the additional layers, and
virtual scanning with three ultrasonic sensors meant that it was
not necessary to set up stringlines. This eliminated both the need
to constantly reposition stringlines and problems resulting from
incorrect positioning choices.
Several Hamm GRW 15 pneumatic tyred rollers and
DV 90 VV tandem oscillation rollers were employed for the final
compaction stage.
A key feature of the DV 90 VV rollers and Hammtronic
management system is the way they continually adjust speed and
oscillation frequency to the surface being compacted.
Finally, adjoining concrete elements – gutters and curbs etc.
– were cast with a Wirtgen SP 250 slipform paver. For this
application, UMB Spedition adjusted the configuration so that
the SP 250 could lay down both the sand base course and the
concrete in the specified profile. This resulted in a substantial
increase in productivity and a high-quality profile.
Compaction strategy
With a similar use of technology, German contractor Heim KG
resurfaced the blacktop on a 3.5 km long, 15 m wide northbound
section of the A7 near Altenstadt, Germany in just twelve weeks,
despite difficult weather conditions.
Heim used two Ammann pneumatic tyred rollers and five
tandem rollers to compact the base layer and binder course and
a further seven Ammann tandem vibration machines for top
layer. Equipment rental company Nagel Mietservice and the
Ammann’s own Hire Pool service provided the machines on a
short-term basis.
Dietmar Nille, Heim’s senior construction manager at the A7
construction site said, “The greatest challenge facing the A7
project was the tight schedule. We had to develop this elaborate
machine strategy to ensure adherence to the schedule. That is why
I got our long-standing partners, Ammann and Nagel, on board
during the bidding phase. Our compaction strategy gave us not
only the advantage of entering the bidding phase with a very good
price-performance ratio, but it also gave us a time buffer.”
As a result, the base layer, binder course
and topping were installed and compacted
over the entire length of the construction
site in just twelve working days. A key
aid to the fast progress was the Ammann
ACE Navigator system fitted to the rollers,
which measures the temperature of the
asphalt as the roller crosses and shows
the number of passes in each lane. The
system regulates amplitude and frequency
continuously and steplessly based on the
asphalt temperature.
In a different type of asphalt project,
Peab Asfalt has used a 9.4 tonne Dynapac
CC334HF split drum roller with equipped
with the compaction control system and
Dynapac’s Compaction Analyzer Asphalt
(DCA- A) to lay 25,000 m
2
of material at
a port project in Karlshamn, Sweden.
>
Drilling innovation
Remote control improves safety and efficiency
M
innich Manufacturing is gaining ground with its wireless remote control technology
for concrete dowel-pin drilling applications. The patent-pending system improves
conditions by allowing the operator to have a better vantage point. By removing
the operator from the drilling unit, the wireless remote control allows workers to avoid dust
and debris as well as seeing the broader view for avoiding obstacles, equipment, and other
workers.
“Minnich’s self-propelled wireless units were simply designed with efficiency and safety
in mind,” explained Todd Jurjevic, sales and marketing director for Minnich Manufacturing.
“We have completely eliminated some serious job site hazards by incorporating this feature
into our self-propelled drills. Crews are working more efficiently, drilling more accurate
holes thanks to the improved vantage point, and the wireless remote control keeps crews
safer by removing them from the action.”
The units carry through other features from Minnich’s range, such as the ability to drill
both horizontally and vertically, adjustable drill height, depth, and centres for accurate
drilling, and the power to tow a portable air compressor. The crab-steering function
meanwhile allows an operator to drive the drill down the slab to the next set of holes
without raising the bed, keeping the unit flush to the slab throughout the drilling process.
Clearspan says its investment in a new G&Z S850 paver has
given it a competitive advantage in Qatar because of the
speed at which it can work and the quality it can deliver.
