Hard skin, thin core.

Utility tunnels, such as sewer tunnels, are subjected to heavy attack by corrosive chemicals. After lining a tunnel bore with segments, a further procedure is therefore necessary to provide an additional protective layer inside the tunnel. This additional work step leads to thicker tunnel walls – so that the outside diameter needs to be correspondingly greater. The solution is a system with a hard utility coating and a thin wall thickness.

A step into the future.

With its concept of Combisegments®, Herrenknecht AG has developed an innovative solution for sewer tunnels. The combined segment brings together tunnelling and final tunnel lining into a single procedure. Using special technology, the inliner (plastic) is cast into the mould with the concrete during segment production. In this way, it is possible to dispense with double-shell lining with an additional sealing level. It is consequently possible to reduce the bore cross-section and therefore also save time and cost.

Combisegments® provide the following advantages:

• Tunnelling and final lining, e.g. with GRP inliners (2-4 m diameter ) in a single procedure.

• Can be used for an extremely diverse range of tunnel types (sewerage, water, electricity).

• Reduced wall thicknesses for considerably lower tunnel outside diameters:

          - less concrete for the segments
          - less spoil
          - lower transport costs
          - faster project implementation

• Reusable shuttering enables use as Combisegments® or standard shutters.

For more information on our Combisegments®, please also read our News of May 2011.

Any questions? Please e-mail us at info(at)herrenknecht-formwork.de, or call us on +49 7824 302 2822.