Crushing concrete

The task

Demolishing concrete structures.

The problem

As part of the refurbishment of a hospital maternity block, it was necessary to demolish a 15 m long section of concrete wall. This could have been done with small pneumatic breakers which might have caused typical worker vibration exposures of 7 m/s² A(8) and created intrusive levels of noise.

The solution

The wall was cut away from the building pillars by drilling lines of overlapping holes (stitch drilling) using a diamond drill. The diamond drilling machine was held in a clamp and so the operators were not exposed to vibration. Each section was then broken up by 'biting' off pieces with a hydraulic concrete crusher. The jaws of this device close slowly, allowing the operators to loosen their grip before crushing takes place.

Concrete crusher demolishing a wall

Using a concrete crusher to crush a wall

The cost

About 50% more than the cost of using pneumatic breakers on the same job.

The result

• The operator's exposure to vibration is negligible.
• Very low vibration is passed into the structure which helps to reduce damage and structure-borne noise.
• This method is less messy than using breakers as the debris is in larger pieces and less dust is produced.
• Noise levels are very low, both for the operators and the environment.

Case courtesy of Specialist Services (Cutting and Drilling) Ltd