A rail tunnel through the mountains of Austria

3 August 2013

In 2022, people living in southern Austria will be able to travel between the region’s two largest cities of Graz and Klagenfurt three times faster than today thanks to a rail tunnel running 33 kilometers beneath a mountain. To deliver this exceptional project, we have created a special cement whose specification is tailored to the local geology.


Only 150 kilometers separate Klagenfurt, capital of the federal state of Carinthia, from Graz, its counterpart in Styria, and the second largest city in Austria. But the train ride currently takes three hours, because the line has to skirt the Koralpe mountain range (highest point 2,140 meters). It’s a real inconvenience, not only for passengers, but also for freight, most of which travels by road with all the associated pollution and risks.

The solution? To go under the mountain, of course! As the centerpiece of the new high-speed rail link between Graz and Klagenfurt, the Koralm tunnel will be one of the longest in Europe. Work began on the project in 2008, and its twin 9-meter tubes will run through the solid rock of the mountain range over a distance of 32.9 kilometers.
When the new line opens in 2022, it will take no more than an hour to make the journey from Klagenfurt to Graz, improving passenger and freight services, as well as boosting the local economy.

Our special cement goes underground!

1.2 million cubic meters of concrete will be needed to build the prefabricated elements of the first two sections and exploration galleries. We have supplied Austria’s largest civil engineering contractor Strabag with the 82,000 metric tons of additives and 350,000 metric tons of cement required. But this is no ordinary cement: we have developed a product whose chemical composition is specifically tailored to the geology of this exceptional project!

LafargeHolcim has also been contracted for its logistical expertise, which has enabled the daily production of 180 prefabricated elements essential for tunneling progress (30 meters per day for both tubes).