PRESS INFORMATION - Darda Gmbh

PRESS INFORMATION
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2011-05-19
Roofless Hospital
BROKK DEMOLITION ROBOT AND CC 420 OPERATE TOGETHER
Blumberg/Stuttgart.Can a carrier vehicle with a concrete crusher be so compact
and light and yet so extremely powerful that this tandem can „bite off“ the roof
of a busy hospital? Yes – a BROKK 180 demolition robot with a mounted DARDA
CC 420 Concrete Crusher is capable of doing so.
This was the scenario in the „Katharinenhospital“ in the centre of Stuttgart. The building
needed to be enlarged, so one storey had to be added. In order to accomplish this, the
roof was first removed. As there was “business as usual” in the sick-rooms one storey
below and there is a shopping street next to the hospital, damages to the building had to
be avoided and the demands on the partial demolition were high: Noise, vibrations, dust
and debris were as much as possible taboo. A demolition by means of diamond
technology had in principle been possible, but the collection of the cooling water and the
disposal of the sludge would have been difficult. Furthermore, this procedure proved to be
quite time-consuming and therefore more expensive.
Compact crushing force was needed
Due to the strong reinforcement a removal of the beams by hand was impossible. Chisels
would have been too loud and would have caused too strong vibrations. The only option
left was to try a concrete crusher at a carrier vehicle. But first there was a snag to this
technique as well: „conventional“ concrete crushers capable of biting reinforced concrete
with a thickness of 40 cm are so massive that they need carrier vehicles of higher weight
classes which are by far too heavy for the limited bearing capacity of the
Katharinenhospital. Not so the Concrete Crusher CC 420 of DARDA, the manufacturer of
demolition tools in Blumberg.
Compared to its size and weight and due to a special pressure transmission it achieves an
enormous breaking force of 374 kN (38 tons). Furthermore, it has an extraordinary
opening width of 420 mm and can therefore easily break concrete parts of a thickness up
to 40 cm. With a cutting force of up to 1,420 kN (126 tons) it even cuts reinforcements

PRESS INFORMATION
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with a diameter of up to 28 mm. Usually only crushers of higher weight classes achieve
such performance values. The CC 420 only weighs 240 kg and works independent of the
working pressure of the carrier vehicle. Therefore it can already be operated with mini-
excavators of the 2.5 – 4 tons class. In the case of the Katharinenhospital a BROKK 180
demolition robot was used. It is ideally suited for operating the CC 420 and with 1,900 kg
belongs to an even lower weight class. It cannot be compared to conventional mini-
excavators of similar classes because its electro-hydraulic drive makes it by far more
powerful.
Quick Results
After a scaffold with tin roof completely encased the Katharinenhospital the old roof cover
was removed by means of a crane. After that the crane lifted the demolition equipment to
the attic floor. Due to the low weight per unit area of the compact BROKK 180 the limited
bearing capacity in the Katharinenhospital posed no problem. Thus, the CC 420 could
crack the coatings at the corner points. With the three-part movable arm of the BROKK
180 it could easily reach any place. The operator stood at a safe distance as he could
comfortably operate the demolition robot by remote control. An ideal view of the
demolition site was also guaranteed because the operator could choose the best place
with his portable control console. Therefore, concrete parts which the crane lifted off the
roof could be broken out fairly silent and with no emission at all. A further advantage of
the DARDA–BROKK tool tandem: within one working week the whole attic had
disappeared. With diamond saws and drills the procedure would have lasted at least four
weeks.
Mr. Storz of the company Storz in Sindelfingen which performed the partial demolition
confirmed: the major assets of the DARDA demolition equipment were the low weight of
the demolition robot and the high performance of the concrete crusher. Otherwise the use
of this technique “above the roofs of Stuttgart” would not have been possible.

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Source: Darda GmbH, Blumberg
More information:
DARDA GmbH
Im Tal 1
D-78176 Blumberg
Germany
Fon + 49 (0)7702 – 43 91 0
Fax + 49 (0)7702 – 43 91 12
mailto: info@darda.de
url: http://www.darda.de
No problem with insufficient bearing capacity: the BROKK 180 has a low weight
per unit area.

PRESS INFORMATION
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The DARDA Concrete Crusher CC420 breaks concrete with a thickness of up to
40 cm and cuts steel reinforcements with a diameter of up to 28 mm.