Shotcrete-Technology ´06

Wet-mix sprayed concrete, a bonus scheme used at the Heidkopftunnel

Dipl.-Ing. Helmut Göhringer, Beton- und Monierbau Ges.m.b.H, Innsbruck
Dipl.-Ing. Dr. mont. Wolfgang Aldrian, Degussa Admixtures Deutschland GmbH

The „Heidkopftunnel - Tunnel der Deutschen Einheit" is a road tunnel linking Lower Saxony and Thuringia. The excavation was done using the drill and blast technique. Wet-mix sprayed concrete, supplied from a batching plant located at site, was used as the means of providing ground support. At the beginning of the wet-mix sprayed concrete application the setup was as known from other sites, a difficult contractual situation with different priorities for each party involved. The site concept was to streamline the priorities in order to achieve their technical and commercial goals. For that reason a contract was signed with the sprayed concrete set accelerator supplier, where the accelerator dosage was linked to a bonus scheme. It turned out, that a technician especially employed for checking the wet-mix sprayed concrete proved vital for the commercial and technical success of the bonus scheme.