Grouting

To prevent potential problems with regard to the tightness between the HD-PE-fleece and the old sewer, especially in the invert region, the procedure during the grouting is determined as follows:

• partial grouting of the external annular space (invert region),
• after a waiting period of two hours: residual grouting of the external annular space and subsequently
• grouting of the internal annular space.

This way the risk that the Trolining^® injector …

The liner is connected to the wall of the target manhole to establish a manhole connection and at the old sewer in the range of the existing starting excavation as a sewer connection. As the sewer has a huge nominal size and the connection to the old sewer is done in the direction of the water flow, no additional measures like e.g. smoothing the transition in the invert region are carried out. This means that the working steps are analogous for both …

Because of the size of the sewer, the reconnection of the laterals is carried out from the inside using the trenchless construction method.

The positions of laterals were measured in the preliminary work, so that the positions in the renovated sewer can be drawn by a marker. A hole is made in the liner at the marked position with a hammer and pointed chisel in order to check whether the lateral is indeed at the indicated position. The approximate …

After re-connecting the laterals, a leaktightness test is carried out according to DIN EN 1610.

As a final step, the finishing works like the reconstruction of the old sewer, the removal of the starting excavation and the replacement of the road surface are carried out.