Kemroc attachments – a cut above the rest

Schnittger GmbH use Kemroc cutter wheel attachments to demolish aging rainwater basins 

TWO aging stormwater overflow basins in Kessel, in the German state of Hesse, are being replaced by larger basins at a sewage treatment plant. To demolish the massive, ring-shaped concrete rims of the basins, contractors Schnittger decided to use specialized cutting technology from Kemroc and, as a result, utilized a DMW 130 cutter wheel to dismantle the rim of the first basin. 

Recently, the company used a larger DMW 220 cutter wheel on the second unit to ensure completion of the demolition of the basins. With a pool height of 4m and an outer diameter of 46m, the concrete walls were up to 2.50m thick, which, according to Schnittger, made the demolition phase extremely challenging. 

The dismantlement process involved the following steps: the excavator drove over a heaped ramp into the basin; positioned itself in the centre; and made a series of cuts through the concrete rim at around 1m apart – first from above, and then from the sides to the ground, creating individual segments. 

Following these phases of works, a 40-tonne excavator broke the segments up using a shearer attachment. The demolished concrete is subsequently transported away for processing at a recycling plant.

The demolition work on the rim of the second basin took four weeks to complete during June/July. Both basins produced 2,000 cubic metres of broken concrete. For Schnittger, the cutter wheel attachments had played a key role in the demolition contract.

According to the terms of the contract specified by Kasselwasser, the municipal firm responsible for the sewage treatment plant, the work had to be carried out with minimal vibration using milling, sawing, cutting or shearing technology. 

Pre-cutting the concrete rims with the Kemroc cutter wheels into smaller, manageable segments turned out to be critical, as Dennis Schnittger, managing director of Schnittger, explained: ‘Cutting through the rim de-stressed the concrete making the subsequent work with the shearer attachments faster and more effective than would otherwise have been the case.

‘The smooth cutting action of the wheel also resulted in much less disturbing noise and annoying vibration for the excavator operator. From our point of view, we can see that these milling attachments will play an important role in demolition projects in the future.’