Cemex is supplying a mobile ready-mix concrete plant as well as concrete for concreting the floor, walls and cover of the Bremerhaven Port Tunnel.
Bremerhaven, Germany, is one of the most important seaports in Europe. The Bremerhaven Port Tunnel is due to open late 2018.
Lutz Petersen, manager of Transportbeton Bremerhaven-Osnabrück, said: “We have contractually guaranteed a maximum hourly output of 80m³ for the tunnel. To fulfill our commitment, we have expanded our capacity through the addition of a mobile production facility. We are, therefore, well positioned to supply the construction site with structural and diaphragm wall concrete, as well as to deliver to our other customers as usual.”
Approximately 30,000m³ of fire-resistant concretes; 80,000m³ of construction concretes, and 90,000m³ of diaphragm wall concretes will be supplied.
The tunnel will be built as a cut-and-cover with water pressure resistant diaphragm walls of up to 32m. The 9m long wall panels are filled with concrete from the bottom to the top using the tremie method, where the end of the pump hose remains permanently immersed below the surface of the concrete.
Cemex developed a special admixture for the diaphragm wall concrete, resulting in stable consistency with limited water content. In addition to the structural concrete used to produce the tunnel floor, the project requires a fire-resistant concrete for the tunnel walls. Polypropylene fibres are added to the fresh admixture via a special system, and in the case of a fire, the fibres would melt, creating open spaces for water vapor to penetrate.
To ensure sufficient capacity during delivery of concrete for the tunnel walls and additional diaphragm walls, an additional mobile ready-mix concrete plant will be erected for the duration of the project, bringing the number of plants supplying this project to three.
“The stationary high silo plant has a capacity of 80m³/hour, the new mobile row of concrete dosing units achieves an output of 60m³, and added to this is the ready-mix concrete plant of our supply partner,” says Lutz Petersen.
“This enables us to ensure continuous supply of all parallel construction stages.”