Cemex de CV : Connecting Ports

Bremerhaven is one of the most important seaports in Europe. It is currently the biggest automobile loading port in Europe, and expected to grow in the next few years. The transportation links must keep pace with the growing volume, and the tunnel is a key infrastructure project. The tunnel connects the city with its international port and associated industrial and commercial areas to the motorway. Also, providing relief for residents, traffic that is currently overground will be laid underground, leading to reduced noise and exhaust emissions, and public vehicles will be separated from private transport. The tunnel will be operated as a tube with bi-directional traffic, with its eastern section divided into two tubes with one-way traffic. The length including access ramps is 1,848 meters (6,063 feet) for the north tube, and 1,659 meters (5,443 feet) for the south tube.

Lutz Petersen, manager of Transportbeton Bremerhaven-Osnabrück GmbH & Co.KG reports: 'We have contractually guaranteed a maximum hourly output of 80 cubic meters 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.'

The near-surface two-lane tunnel will be built with the cut-and-cover construction method. The water pressure resistant diaphragm walls have a depth of up to 32 meters (105 feet). The nine meter (30 foot) long wall panels are filled with concrete from the bottom to the top by means of the tremie method, whereby 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, ensuring the required quality. In addition to the structural concrete used to produce the tunnel floor, the project requires a fire-resistant concrete for the tunnel walls. Polypropylene fibers are added to the fresh admixture via a special system, and in the case of a fire, the fibers 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 3.

'The stationary high silo plant has a capacity of 80 cubic meters per hour, the new mobile row of concrete dosing units achieves an output of 60 cubic meters; added to this is the ready-mix concrete plant of our supply partner', explains Lutz Petersen. 'This enables us to ensure continuous supply of all parallel construction stages.'

From providing several concretes to meet the challenges of tunnel construction to doing so in a reliable and timely manner, CEMEX in Germany has been helping to build a better future in Europe, solving customer needs for many decades.

CEMEX is a global building materials company that provides high quality products and reliable service to customers and communities in more than 50 countries. Founded in 1906, CEMEX has a rich history of improving the well-being of those it serves through innovative building solutions, efficiency advancements, and efforts to promote a sustainable future.