Sewage treatment plant expansion valued at about 40 million euros in Forchheim with the second largest final sedimentation tanks in Germany for 600,000 residents.Germany’s second largest final sedimentation tanks were created as part of the sewage treatment plant expansion project in Forchheim, serving as many as 600,000 inhabitants. In order to produce the reinforced concrete structures, Ed. Züblin AG relied on formwork systems from PASCHAL.
Formwork systems from PASCHAL shaped a wide range of concrete structures
Several systems from PASCHAL were used at the construction site for the various concrete structures – an impressive undertaking demonstrating that all formwork requirements can be addressed quickly and efficiently with formwork systems from PASCHAL.
Foundations and base plates were built with the Modular universal formwork and the walls were completed using the LOGO.3 system. The height extension brackets were used for certain sections of the walls to enable smaller height extensions to be constructed flexibly and without additional panel formwork. To make the reinforced concrete slabs, Züblin used Paschal Deck combined with mobile, crane-borne slab tables assembled out of the GASS shoring system. And for curved structures, the TTR trapezoidal girder formwork demonstrated its versatility for forming both the floor and slab plates and the circular tank walls, and delivered impressive results in terms of precisely definable curve radiuses.
The concrete haunch on the inside of the curved tank walls was produced up to full height in a single work cycle with system parts.
KBK climbing platforms accessible via safe stair towers were used for the elevated work sites.
Circles made easy with the TTR from PASCHAL.
In the bottom image area:
The curved wall structure for final sedimentation tank no. 5 is formed with the TTR trapezoidal girder formwork at a forming height of 5.25 m including the haunch formwork at the base with an inside diameter of 72 m and concreted in one height operation.
In the top image area:
The base plate edge formwork for final sedimentation tank no. 6 was formed with an outer diameter of 73 m and with a formwork height of 0.75 m using the Trapezoidal girder formwork. The circular centre structure is visible in the middle of the tank.
The sewage treatment plant expansion project valued at about 48 million euros includes an additional aeration tank occupying a construction area of 330 m x 150 m, two final sedimentation tanks with an external diameter of 73 m, for which parts of the footing base were about 8.00 m below ground level.
Some parts of the final sedimentation tank are below the groundwater level and were constructed using a special building process, which is why underwater concrete was used.
During the formwork planning stage, Züblin relied on the skills of the formwork experts at PASCHAL, who used the PASCHAL Plan-Pro software to plan the formwork.
Consequently, Züblin received comprehensive, detailed formwork plans which provided invaluable support for the entire building undertaking. "Despite the size of the project, the widely differing reinforced concrete structures and formwork, construction work went ahead quickly and smoothly," recounts Senior Engineer Ulrich Geitz.
The circular centre structure with an outer diameter of 10 m and with a formwork height of 5.25 m, with the TTR Trapezoidal girder formwork. The interior space was closed completely with Paschal Deck.
Demanding reinforced concrete structures completed exactly to size and on time.
After the reinforced concrete structures have been produced and accepted, the technical components have to be installed and mounted, so that the entire facility can be commissioned in 2019 according to plan.
"This is why it is very important for us that the base structures are completed on time and with the correct dimensions," says Günter Wazeck, foreman at the treatment plant site. "We like working with PASCHAL, we have always had very good experiences with the way they prepare the project, including formwork planning and with regard to the economical use of the formwork. The whole package gives us the certainty we need that we will be able to complete construction by the deadlines, and perhaps even before," adds Wazeck.
LOGO.3 wall formwork in the last wall section of the 84 m x 40 m aeration tank closed with a formwork height of 6.80 m.
Next phase already in view – completion by 2021.
Attention is already being turned to the next expansion of the sewage treatment plant, which is why one and a half hectares of woodland has been purchased from the community of Forchheim.
On this site, there are plans to build an operations building with offices for 70 employees and the necessary operating and warehouse areas. According to the master plan, the target commissioning date is in 2021.