One of the largest phases of construction on the Brenner Base Tunnel, a railway link being constructed below the Alps between Austria and Italy, is underway.
The project, which has been under construction since 2008, is set to deliver the longest underground railway link in the world, at a length of 64km.
An important phase of construction on the Austrian side is construction lot H51 “Pfons-Brenner”. Construction work began there in late autumn 2018.
When complete this infrastructure project will provide a key trade link for Austria and the European Union. It was therefore important to use constant high-quality grade concrete in the construction of the tunnel.
The lead developer on the project, Austrian contractor Porr – also working on a major Polish rail contract, has enlisted two Liebherr Betomix 3.0 mixing plants produce concrete for this part of the project.
In the application process, the excavated tunnel tubes are secured with plastic and steel fibre reinforced shotcrete. The exact concrete mix is then adapted to the condition of the rock in the tunnel, which changes over its entire length.
Large quantities of concrete must be delivered in reliable formulations with mixed-in fibres into the pipes.
Another important aspect which needs to be considered is the logistics of moving the concrete. For this purpose, special railway tracks have been lain for the concrete collection and for the material delivery of rock. The cement is delivered by truck in silo trains.
The two Liebherr-Betomix 3.0 plants for concrete mixing come together with two 3m³ twin-shaft mixers which provide a maximum output of around 240m³ of compacted fresh concrete per hour.
The Betomix plants utilise a modular design plant concept, which can be optimally adapted to the local conditions.
Given the scale of the project, a good amount of storage for aggregate materials is also necessary. Liebherr also provided two of its new high silos – each capable of storing 600m³ of sand and gravel in seven chambers – and twelve binder silos, each with a capacity of 100 tonnes, supply the two plants with the required cement types.
The construction of the full tunnel is expected to be completed by the end of 2027.