CBE Group, France

CBE Group is a French industrial midcap company, specialized in the engineering, production and installation of steel moulds, equipment and tailor-made automated plants used for the production of every type of concrete pieces. Its field of application usually covers subways, roads, railways, water conveyance tunnels, ports, airports or cable tunnels, on which CBE Group intervenes as a subcontractor for large construction companies or joint-ventures

Segment Moulds

The segment geometry and materials are defined according to the tunnel geometry layout. As each tunnel is unique, so are its segment and mould. The mould being entirely dependent on the segment geometry, its engineering can only be made according to the segment concrete design. Therefore, the concrete design supplied by the engineering department is a crucial step within the mould development process. The overall success of a project lies within the TBM efficiency and the quality of the moulds. The better the mould quality, the more segments are produced and the faster the TBM is supplied, all meaning that the client gets optimum profitability for his project.

Segment Precast Plants

The installation of segments (point) while the TBM progresses, requires a constant supply of segments Any stopping of the TBM due to lack of segments or poor segment quality would be disastrous and very expensive. On the other hand, time is a key factor for concrete maturity. Even with the curing room methods required due to time limit reasons, the segments need to be stored for nearly a month before they can be used for the tunnel, and this in order to ensure the concrete maturity that will allow its mechanical resistance. Segment engineering is a process that represents an important part of the tunnel project, it requires the setting up of a precast plant, either a stationary or a carrousel-automated one. The choice between those two techniques is often cost or time driven.

Carousel Precast Plants

With this option, moulds are automatically conveyed towards the designated workstation:

To be then transported to the curing room where they remain for approximately 6 hours, depending on the concrete attributes and the segments size (thickness), before returning to the production line where the segment will be removed from the mould on the designated workstation.

This system enables a 30 to 40% increase in productivity.