From Realtà Mapei International n° 81 - 8/14/2020

The Semmering Base Tunnel in Austria

A groundbreaking project is on track with gigantic amounts of concrete prepared with Mapei admixtures.

Location icon Gloggnitz nach Mürzzuschlag

The new Semmering Base Tunnel, apart of the "Baltic-Adriatic axis" transportation corridor, is one of the most important infrastructure projects at the heart of Europe.It is also one of the most complex European tunnel constructions.
Implenia & Swietelsky Tunnelbau GmbH was awarded the contract for the mega construction, which poses many challenges, not least due to the geological conditions.

A full 14 years are planned for the construction of the entire 27 km length.
The 13 km section at Fröschnitzgraben alone is scheduled to take about 13 years to be completed.

Before tunnelling work at Fröschnitzgraben could even begin, two 400 m deep shafts of around 10 m diameter had to be excavated. At their base, an enormous cavern was formed: a gigantic underground building site. This was the starting point for the excavation of the tunnel tubes.
The 4 km section towards Mürzzuschlag is currently being dugout using excavators and blasting.
The 9 km section towards Gloggnitzis being excavated out by two tunnel boring machines.


There is a long tradition in Austria that every tunnel construction receives a patron. It goes back to the legend of Saint Barbara, who once had to flee from her tyrannical father. God opened up a crevice in the rock face so that she could hide in it. Since then, she has been the patron saint of miners. According to the custom, a tunnel patron is the earthly representative of Saint Barbara. She is meant to bring good luck to the project and the workers during the construction phase.

At the Fröschnitzgraben, this honour was awarded to Andrea Kapoun, Marketing Manager at Mapei GmbH (Austria). A bit of luck is always handy. Above all, however, skill and the perfect interaction of all participating companies are required.

This is why Mapei admixtures for concrete and the Mapei mobile laboratory are both present on site to ensure the proper concrete mix is achieved.
An incredible 850,000 m3 of concrete is required for the works in Fröschnitzgraben – all of it processed by Mobil Baustoffe GmbH, a worldwide leading specialist in large construction projects and a Mapei partner.
Among the chosen admixtures one finds: DYNAMON RC520* and DYNAMON LZ SP W20*, two polycarboxylate-ether-based superplasticizers, DYNAMON LZ553*, a plasticizer used to extend the workability of concrete, MAPEAIR LP 100*, an air entraining agent for freeze-resistant concrete, and the retarding agent MAPETARD VZM*. All these products are distributed on the Austrian market by Mapei GmbH (Austria).

Project data sheet

Yard Tunnelbau
Location Gloggnitz nach Mürzzuschlag, Austria
Subcategory TUNNEL
Application Tunnelbau + Laborleistungen
Application Type Underground constructions, Supplying of admixtures
Client ÖBB Infrastruktur AG
Contractor company Mobilbaustoffe
Designers (for works) Planungsgemeinschaft Semmering- Basistunnel neu
MAPEI Coordination Kaufmann Herbert
Realtà Mapei Tags: #mixdesign #Admixtures for concrete

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