CK Abbruch & Erdbuch opt for Kemroc attachment
Demolition specialist reaping the rewards of DMW 220 100 cutter wheel excavator attachment
DEMOLITION firm CK Abbruch & Erdbau GmbH have successfully demolished an old hospital building in the city of Konstanz, on the shores of Lake Constance, in southern Germany.
However, owing to the specific requirements of the project, the work was far from straightforward for CK Abbruch & Erdbau, as the company faced some unexpected challenges along the way.
Whilst the first phase of the scheme was clear and uncomplicated, and saw the specialist contractor demolish around 40,000 cubic metres of the old Vincentius Hospital building, it was soon discovered that the structure was built on a 2,000 sq metre concrete foundation slab up to 1.1m in thickness.
After weighing up all options and calculating expected costs, Markus Christadler, managing director of CK Abbruch & Erdbau, chose to use a Kemroc cutter wheel mounted on a 40-tonne excavator. ‘It would have been quicker with a larger excavator and hydraulic breaker, but under these conditions, it was not possible,’ he commented.
The demolition firm hired a Kemroc DMW 220 1000 cutter wheel with a 1m cutting depth for a trial and, after testing the attachment on an excavator, purchased an identical model to complete the first phase works.
According to Mr Christadler, the Kemrock cutter attachment proved to be the most economical solution by far, and the most environmentally friendly for the company.
‘We achieved average rates of 10–15m cutting length per hour, which gave us a production rate equivalent to using drill and blast but at a much lower cost,’ he said.
‘The noise monitors didn’t record any high values. Drilling 800 to 1,000 bore holes would have been much noisier and uncomfortable for the people living nearby. In addition, at surface levels, the cutter wheel was working under a small depth of water so there was very little dust generated.’
An independent report had ruled out the use of an excavator with a hydraulic breaker due to high noise and vibration levels. It was also discovered that vibrations from a breaker could have damaged a neighbouring listed building, which had to be preserved.
CK Abbruch & Erdbau clearly reaped the benefits of using the Kemrock DMW 220 1000 cutter wheel, thanks to the enhanced sustainability credentials of the project by diverting building waste from landfill.
As a result of the takedown of the hospital, the demolished large concrete blocks were further broken down using a shear before being processed in an on-site mobile crusher or transported away to a recycling facility.
Mr Christadler concluded: ‘The cutter wheel attachment is well suited for the demolition of concrete in urban environments where there are major constraints on pollution.’