Bridge demolition success for Kemroc
Max Wild GmbH dismantle motorway bridge in southern Germany using DMW 220 cutter wheel attachment
BASED in Berkheim, south of Bavaria, demolition contractors Max Wild have successfully completed the dismantlement of the old Saar Bridge at the Saarlouis autobahn junction in southern Germany.
To make way for a newer, modern bridge with a higher capacity, the plan for demolishing the older bridge involved breaking down the concrete structure into separate sections that could be placed on pontoons and floated to a crushing facility on the riverbank.
In order to remove the lateral cantilever arms and the concrete slab between the two hollow boxes, the civil engineering team at Max Wild decided to use a Kemroc DMW 220 cutter wheel attachment mounted on a 40-ton excavator for the sensitive and challenging demolition work passing over river Saar.
The DMW 220/1000/130 cutter wheel excavator attachments are renowned for their superior cutting force, increased productivity and ability to perform in tough applications. Equipped with two lateral hydraulic motors, the Kemroc attachments have been designed to provide high cutting forces, including breaking down heavily reinforced concrete and rocks with a uniaxial compressive strength of 120 MPa.
Demolition of the old bridge started following the completion of four lanes of the new bridge in November 2020. One of the main challenges encountered on the project was the heavy resistance across the bridge panel spanning the Saar river.
Before cutting and removal, two pontoons with a special framework were strategically placed under the bridge panel to support two hollow box sections, which would later be transported. The procedure involved cutting out the reinforced concrete into segments (weighing from six to 10 tons) longitudinally along the bridge axis with a concrete saw and Kemroc DMW 220 cutter wheel.
According to Kemroc, the ability of the DMW excavator attachment to cut down to 65cm depths made the task at hand much easier than would have been possible with conventional cutting and sawing techniques and equipment.
Max Fus, site manager for Max Wild, commented: ‘The bridge was tensioned in a transverse direction and it was therefore structurally difficult to cut through. Nevertheless, I was surprised that the cutter wheel did not appear to perform differently when it was cutting through prestressed or non-stressed concrete.
‘Working with a combination of diamond saw technology and the cutter wheel, we made relatively quick progress and achieved cutting speeds of around ten linear meters per hour.’