33
november 2013
international
construction
ROAD BUILDING
Technological advantages
>
and leaving it to dry out, before making
another pass with the CS74B. This time
the screen turned green.
Failing to locate the problem and take
action would have been costly. The section
might have failed testing and required
time-consuming re-work. It also could
have gone unnoticed and led to premature
failure.
A second benefit was the dramatic
productivity improvement. Traditional
method specifications would have
required eight passes on this scheme. McAninch crews – with the
help of MDP – were able to verify that only two or three passes
were enough to reach the target.
Transylvanian motorway
The construction of the 588 km A3 – the Transylvanian motorway
– was given the go-ahead in 2004. Once completed in 2017 it will
link the Romanian capital Bucharest with the Hungarian and the
M4 motorway.
One of the consortiums winning work on the 62km section
from Bucharest to was Spedition UMB /Pa&Co International /
Euroconstruct’98/Com-Axa. Spedition UMB opted for Wirtgen
Group equipment and solutions for all construction phases, from
the foundation and soil stabilisation,
paving and compaction of asphalt, to
construction of the adjoining concrete
gutters and curbs.
Six 20 tonne Hamm 3520 vibratory
rollers compacted the soil in two groups
of three machines operating in echelon.
They were equipped with HCQ meters
to check the degree of compaction in real
time and indicate any corrections that
may be necessary.
They were also equipped with the
Hammtronic microprocessor control
system to optimise machine functions,
ensuring economical use of consumables,
optimum compaction results and
maximum safety.
Soil stabilisation was carried out in-
situ by a machine set comprising an
SW 16 TA binding agent spreader,
Wirtgen WR 2500 S recycler and Hamm
3518 compactor with an operating weight
of 18 tonnes.
the original site plan that TACC adapted for use with the
Topcon GPS machine control systems by creating its own 3D
digital model.
TACC Construction faced three production deadlines with this
project. “We beat each deadline by two to three days, which is
pretty impressive considering how tight they were,” Mr Saracino
said. “This was our first project where we were totally integrated
with technology on our earthmoving and road construction. The
technology provided seamless transition from task to task.”
Ramp challenges
Meanwhile in Iowa, US earlier this year
an unseasonably wet spring presented
big challenges for the construction of
a highway ramp on the I-80 highway.
However, contractor McAninch was able
to tackle the project with the help of
Caterpillar’s Machine Drive Power (MDP)
compaction measurement technology.
The system evaluates rolling resistance
to provide an indication of soil stiffness
and load-bearing strength. On this job
it McAninch said it improved productivity by enabling crews
to make fewer passes and it helped them avoid quality control
problems that could have resulted in re-work and lost time.
The operator viewed real-time results on the Cat CS74B soil
compactor’s in-cab monitor. This was fitted with Cat Compaction
Control, a compaction measurement tool that includes MDP.
The monitor was configured to display green when the area
had been covered and compaction targets met, and red for
problem areas.
For example, a problemwas flagged when the display was still red
after two passes over a particular area. Given the site conditions,
this indicated lots of heavy clay and probably too much moisture.
This was tackled by turning the soil with a disker (harrow)
Clark Construction used a fleet
of Roadtec equipment, including
an SP-200 paver to 24 km of
U.S. Highway 281 in Texas, US.
Contractor Heim rented a fleet of Ammann compactors fitted
with the ACE Navigator system to help resurface a section of
the A7 in Germany. ACE Navigator amplitude and frequency of
the roller vibrations according to the asphalt temperature.
Spedition UMB
opted for a fleet
of Wirtgen Group
equipment for
every phase of
its work on the
A3 highway in
Romania.
