The electric power company Vattenfall had constructed a coal-burning power plant in Moorburg, a district of Hamburg. Three new ash filter tanks were built as part of the power plant.
The first tank has a height of 55 m and a circumference of 70 m. The tank is post-tensioned with eight strand tendons consisting of 15 strands each and 100 horizontal strand tendons consisting of nine strands. On the whole, 45 t of strand tendons were produced, supplied and installed for the 55 m high tank.
580 t of post-tensioning steel were installed in two tanks
The other two silos have a height of 70 m and a circumference of 100 m each. 282 strand tendons consisting of 12 strands each, 128 strand tendons consisting of nine strands and 24 strand tendons consisting of five Ø 150mm² strands with a total post-tensioning steel weight of 580 t were installed in these tanks. The tendons are anchored at the exterior walls of the tanks on four buttresses, with two tendons forming a full circle and the next post-tensioning group being aligned at a displacement of 90°.
Assembly carried out on two suspended platforms
The main challenge was that the individual tendons had to be subsequently installed, post-tensioned and grouted at a height of up to 70 m. Assembly was carried out on two suspended platforms, with the jacks being mounted on separate lifts. Two jacks at two opposite buttresses were used to tension full circles. The grouting of the tendons was also carried out on the suspended platforms.
Despite the fact that construction work was often obstructed by storms, the installation, post-tensioning and grouting work at the two large tanks was carried out within a very short time-span. The power plant was inaugurated officially on 18 November 2015.