Dyckerhoff (Buzzi SpA) has supplied more than 71,000m3 of concrete for the construction of the new section of the U81 light rail line, which from 2025 will connect Düsseldorf Airport to the Freiligrathplatz metro stop.
The existing U81 line stop at Freiligrathplatz has been expanded, and a high-performance concrete based on Portland PZ Dreifach [CEM I 52.5 R] cement was chosen to ensure continuous operation. The tunnel ramp structure and the new airport subway station will be constructed in the open air, over a total length of about 600m. To protect the excavation from landslides and groundwater infiltrations, diaphragm walls and trench walls were built, using about 20,000m3 of C25/30 strength class concrete.
The tunnel floor was made of C25/30 underwater concrete using the tramie method, with the deployment of frogmen and shaft pumps from Dyckerhoff, with flow rate of 46-52m, in three pourings of 800m3 each. Dyckerhoff says this results in a compact and load-bearing structural element even without vibration, this concrete must be fluid and resistant to segregation.
The U81 project, which is fundamental to the development of local public transportation, will involve the implementation of three additional construction phases, which will enable the light rail line to be extended to other major areas and neighbouring municipalities. This project represents the most important infrastructure project in the city.
