27
november 2014
international
construction
ROADBUILDING
Project pressures
R
oad repair and rehabilitation is a major activity all over
the world, and great strides have been taken in recent
years increase the amount of oldmaterial being recycled
and re-used when highways are restored to their former glory.
A particularly interesting area is in-situ recycling, where a train
of equipment can be used to re-lay the oldmaterial in a single
process, which speeds up repairs andminimises disruption.
For example, when Dunn Company won the contract to
rehabilitate two stretches of country roads CH 11 and CH 20
inChampaignCounty, Illinois,US it chose aWirtgen3800CR
cold recycling machine, working a Vision 5200-2 paver from
sister company Vögele and an HD+ 140 VV and HD+ 110
VV roller from the Wirtgen Group’s compaction equipment
specialist,Hamm.
The technique used was the down-cut
process, where the drum rotates in the
directionof travel, with the picks coming
down onto the surface being cut. This
offersmore control over particle size than
‘up cutting’, especiallywhenmilling thin
surfaces.Oncemilled, the asphaltwas fed
directly to the Vögele paver for relaying,
before final compaction by the Hamm
rollers.
CH 20 was relatively straightforward,
with the recycling process starting
straight away. However, onCH 11, a 40
mm surface course had to be removed
Cold in-situ recycling techniques are proving their worth
around theworld in the rehabilitation of asphalt roads,
andmachine control andmonitoring technologies are
delivering greater efficiency in the concrete and asphalt
sectors alike.
Chris Sleight
reports.
>
Route to success
Brazilian contractor Brown Brown used specially adapted
cold recycling techniques to rehabilitate a section of
BR-381 between Sao Paulo to Belo Horizonte.
Dunn Company used aWirtgen
3800 CR, Vögele Vision 5200-2
paver and HammHD+ 140 VV
and HD+ 110 VV rollers for the
in-situ recycling of two county
roads in Illinois, US.
