Removal of the sloping sides from fifty settling basins (6 m x 4 m 7 m), in a sewage treatment plant. The sloping sides had been cast to improve drainage efficiency, but failed to function as designed. For this reason, the sloping sections had to be removed.
The original flat bottom floor of the basins had to remain without damage. The 7 meter high walls and the sloping floors of the basins, severely restricted working conditions.
A crane was used to lower a mini excavator with hydraulic breaker into a basin, a costly and elaborate operation. The excavator had little room to work and limited movement. later, it turned out that the hydraulic breaker was not suitable for this demolition task.
Darda With two Darda C 11 SN splitting cylinders and a D 2 diesel power unit, concrete sections measuring 1.2 m x 1.2 m x 1 m could be split out in a controlled way without causing any vibrations. Only the splitting cylinders themselves were lowered into the basin. Long hydraulic hoses were used to connect the splitting cylinders to the power unit, which remained above the basin wall. With this arrangement, the demolition tools required little space and the concrete sections could be craned out without any problems. One person was able to complete a basin in only 1.5 working days.