PORR Bau choose Liebherr concrete plants
Two Betomix 3.0 mixing plants delivering precise formulations for Brenner Base Tunnel project
TWO Liebherr Betomix 3.0 mixing plants are currently producing concrete for the Brenner Base Tunnel project – one of the most important infrastructure projects for Austria and the European Union.
Construction work on the Brenner Base Tunnel, which will allow for a rail link between Austria and Italy, has been under way since 2008. At 64km, it will be the longest underground rail link in the world. Construction is due to be completed by the end of 2027.
One of the largest construction phases on the Austrian side is lot H51 ‘Pfons-Brenner’, where work began in late autumn 2018. This contract was awarded to a consortium led by PORR Bau GmbH.
The excavated tunnel tubes are being secured with plastic and steel fibre reinforced shotcrete, with the precise concrete mix being adapted to suit the condition of the rock in the tunnel, which varies over its entire length.
As such, concrete supply has to be well organized: large quantities must be delivered reliably in the ideal formulations with the fibres mixed in. The long transport route also has to be taken into consideration.
When planning the mixing plant, large aggregate storage volumes, reliable concrete output, fibre addition and dosing arrangements, limited space for positioning and assembly of the plants, and 24-hour operation, even in winter, had to be taken into account.
Another important criterion was logistics. For this purpose, special railway tracks were laid for delivery of the raw materials and the finished concrete.
PORR chose two Liebherr-Betomix 3.0 plants for the mixing facility. Together, these two 3 cubic metre twin-shaft mixers offer a maximum output of around 240 cubic metres of compacted fresh concrete per hour.
Thanks to the modular design of the Betomix plant concept, the plants could be optimally adapted to suite the local conditions.
The storage of large volumes of aggregates within a small footprint was achieved through the use of two new Liebherr high silos. Each of the silos can store 600 cubic metres of sand and gravel in seven chambers.
Twelve binder silos, each with a capacity of 100 tonnes, supply the two plants with the required cement types. The fibre-dosing system, which forms part of the mixing plant, allows the plastic and steel fibres to be dosed separately.
In choosing the plant, PORR Bau say the decisive factors were the quality, modular design and short delivery time for Liebherr mixing plants.