South of Asse II, an abandoned salt mine now used for storing low- to medium-level nuclear waste in the district of Wolfenbüttel in the German state of Lower Saxony, a rainwater retention basin was constructed of rectangular concrete pipes supplied by Berding Beton GmbH. The rainwater is transported via the public sewer network. The construction of an upstream retention facility was necessary to prevent the sewer network from becoming overloaded in heavy rain events.
The client decided on a closed construction in the form of a sewer with storage capacity and overflow of precast concrete parts primarily based on the maintenance costs for the entire time of utilization and the existing spatial conditions.
27 rectangular pipes installed in two sections
The expected service life of the facility is at least 70 years, about double as long as that of a typical settling basin; maintenance work is not necessary. Only the filtered out sediments have to be disposed of at regular intervals. The rainwater retention basin consists of 27 rectangular concrete pipes of (L x W x H) 3 x 5 x 2 m each, divided up into two sections. The wall thickness is 250 mm, corresponding to an individual weight of 31 tons.
“Thanks to the close collaboration with Berding Beton GmbH, we were able to find the best solution for this construction project already well in advance,” praised Jürgen Manthey, site supervisor, the contractor Stratie GmbH. “In this way, the complete facility could be installed within just three days.”