Darda ROCK SPLITTERS

Application Report - Demolition of heavily reinforced concrete

Ceiling demolition - bunker demolished inside a building

The Job:
The remains of an air-raid shelter had to be
demolished in a historic-society protected house in
Elsenheim, France. The concrete ceiling was thicker
than the ceilings in the other rooms, which caused it
to project into the upper floor. The ceiling consisted
of three layers, of which the upper and lower were
very hard, and the middle soft and crumbly.

The requirements:
The walls, 1.3 m thick, were very heavily reinforced. As the bunker was inside a building the work had to
be accomplished without noise, pollution, excessive
dust or vibrations. A conventional hydraulic breaker
proved incapable of demolishing the ceiling because
the outer layers were too hard. It only produced
severe vibrations.

The solution:
The work was conducted from the floor above the
shelter. First, the requisite holes were drilled with a
DR 086 mini drill rig. This was mounted to a small
Brokk 150 demolition robot. Following this, a single
C 12 N splitting cylinder was used to demolish the
hard, uppermost layer of concrete (about 45 cm
thick). Powered by an electric EP-type hydraulic unit,
it produces the minimum of noise, dust and vibra-
tions. It proved possible to remove the next, softer
layer with a hydraulic breaker, also mounted to the
Brokk 150 robot.
The third, hard layer was demolished in turn with the
C 12 N splitting cylinder and EP power unit. Given the
specified conditions, it would not have been possible
to demolish the shelter ceiling without a hydraulic
rock and concrete splitter.