Professional concrete protection

All advantages at a glance:

  • Tunnel lining for supply and disposal tunnels in a single step

  • Concrete segment with integrated protective plastic inliner and sealing profile

  • Comprehensive corrosion protection

  • Precisely manufactured with proven materials

  • Suitable for internal diameters from 2,000 mm upwards

  • Lower wall thickness and simplified work processes reduce project times and costs

Further information


Application of Combisegments®  

The concept of Combisegments® has been specifically developed for lining tunnels with segments with a minimum inner diameter of 2 meters. The flexible moulding technology means segments can be manufactured to customer specifications, no matter how diverse they are. With Combisegments® the lining of water, sewage or cable tunnels is realized in a single pass. The protective lining made of plastic (inliner) and an integrated sealing frame provide excellent corrosion protection, for example, against aggressive wastewater. In comparison to the double-shell lining, the single-shell lining of Combisegments® reduce the excavation diameter. A second lining step is not necessary, since the inliner is already anchored in the mould with the concrete segment during segment production. This innovative material combination of reinforced concrete and inliner with an integrated sealing profile offers great potential for saving time and money in supply and disposal tunnels, especially in the sewage sector.

Single-shell lining, reduced costs

Using Combisegments® not only reduces construction times, but also the tunnel wall thickness. The plastic inliner is cast into the mould using a special adhesive technology. The conventional additionally necessary protection layer is not needed. This means that the wall diameter of the lining ring and thus also the excavation diameter can be reduced. The Combisegments® method therefore greatly influences the construction costs. A smaller external tunnel diameter means less concrete for the segments, less excavated material and lower transportation costs.

Compared to conventional segment production, Combisegments® differ only in that they use an inliner with an integrated sealing profile, which is inserted into the mould at the beginning. This operation takes only seconds. After fixing the reinforcement cage, the grouting vent and the connecting dowels, the segment can be cast as usual.

Always perfectly sealed

Tailored to the customer and the project, the Combisegments® protective lining is designed and developed in tandem with the associated mould technology. In series production, proven and corrosion-resistant materials are used and benchmarks are set in quality control.  Without any intermediate steps, the supplied concrete protection lining is placed in the respective segment mould. Subsequent gasket assembly is not required.

Tunnelling with Combisegments® completely eliminates the need for time-consuming welding and inspection work. To ensure a durable concrete bond, on the back and in the area of the sealing level the concrete protection lining is provided with an anchor structure. Required erector dowels and additionally needed segment inserts are integrated into the Combisegments® protective lining by Herrenknecht Formwork during production. Combisegments® are thus transported and installed like conventional segments. At the same time, the inserts allow the attachment of supply lines during the construction phase. After tunnel completion, openings can be sealed watertight with appropriate sealing caps.

In addition to the convincing quality features, the economic benefits are remarkable. With each step saved, the project costs are further reduced.

To the Formwork-Website

Still got questions?

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Steffen Dubé President and General Manager Herrenknecht Tunnelling Systems USA Inc.
Gerhard Goisser Commercial Manager Herrenknecht Tunnelling Systems USA, Inc.

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Steffen Dubé President and General Manager Herrenknecht Tunnelling Systems USA Inc.
Gerhard Goisser Commercial Manager Herrenknecht Tunnelling Systems USA, Inc.