Everything flows smoothly when fastening

Hydropower Plant Renovation in Biessenhofen with fischer Injection Mortar System FIS EM

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Everything flows smoothly when fastening
References
The renovation progressed quickly – until frequent flooding damaged the temporary dam in the Wertach River, which had been built up with gravel. This dam had been constructed in coordination with the responsible nature conservation authorities. All attempts to keep the water away from the weir system using "Big Bags" – one cubic meter large plastic bags filled with gravel – failed. Further flooding caused the water level to rise so much that the sluices were opened and the water retention system was damaged multiple times. As a result, further work in the area of the weir system on the side facing Bärensee had to be paused initially. In the direction of Bachtelsee, pillars and walls around the turbine inlet still needed to be renovated. VWEW-energie, as the operator and client, overcame the challenges posed by flooding, following the proposal of the engineering office Dr. Ing. Koch Bauplanung GmbH and with the involvement of the contracted diving company Kerlen Taucher GmbH, by having a new reinforced concrete wall constructed. This was then placed adjacent to the existing dam wall and measures approximately 2 m thick and 9 m long. After being "raised," the reinforced concrete wall, in conjunction with a needle gate, will separate the Wertach River from the work areas.

Project profile

Client:
VWEW energy
Construction Planning:
Engineering Offices Dr. Ing. Koch Construction Planning GmbH
Project scope:
Hydropower Renovation
Diving company
Diving Master Company Kerlen Taucher GmbH
Suitable for the application, our fischer injection mortar FIS EM has an approval for water-filled drill holes according to anchor theory
Bernd Wetzel (fischer Application Mechanic)
The specialists constructed the wall by fastening B 500B reinforcing steel with fischer injection mortar FIS EM 1500 S in combination with couplers with a diameter of 20 mm to an existing base slab. The installed material, which complies with ISO and Swiss SIA standards, has the property of being highly ductile, meaning it can plastically deform under load before failing.
This allowed the drill holes with a diameter of 25 cm to be successfully filled with the injection mortar and the concrete to be secured with the system. “Additional advantages are that the solution, alongside other system components, is specifically suitable for reinforcement connections from 8 to 40 mm diameter in concrete and offers high load values,” adds the certified construction technician. “The system temperature up to 5° also makes it suitable for underwater installation.”
The construction substrate was not normal concrete. In advance, Bernd Wetzel, together with employees of the executing construction company Xaver Lutzenberger GmbH & Co. KG, conducted extensive tests. Through pull-out tests, the experts checked the load-bearing capacity of the installed system consisting of injection mortar FIS EM, reinforcing bar, and concrete using a rock anchor testing device at 200 kN tensile force, which was determined in coordination with the engineering office Konstruktionsgruppe Bauen AG. For this purpose, the employees of Lutzenberger GmbH travelled by boat over the fastening points where anchoring was done. Using a reinforcement coupler as a connection, they extended the bars and attached a steel pipe to it. The testing device was placed on this and pulled accordingly.
We generally use only fischer products for underwater installation
Karl Kerlen (from Kerlen Taucher GmbH)

To avoid the risk of the FIS EM cooling down and becoming viscous due to the low water temperature, it was warmed before installation. Subsequently, the commissioned commercial divers from Kerlen Taucher GmbH, who had previously created the drill holes, informed Bernd Wetzel via radio when they needed more mortar. The fischer specialist then injected this on demand through a hose, and the divers filled the drill holes with it. In this way, the weir system was successfully drained and reinforced. “When using the fischer injection mortar system to reinforce the reinforced concrete wall in the Wertach, for example, we can be absolutely sure that it withstands the extreme conditions,” emphasizes Karl Kerlen from Kerlen GmbH.
As a result, a stable reinforced concrete wall was created, enabling the repair and functional preservation of the 1960s facility – and ultimately the ecological generation of electricity from water – to be maintained.

The fischer products used

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