Renovation of the Gottfried Böhm parking garage

The construction consists mainly of prefabricated steel and prestressed concrete elements, the roof structure is made of steel. Due to damage caused by chloride ingress and defective grouting joints, the renovation of the parking garage was initiated in 2021. The plan was to almost completely renovate the lowest parking level, install precast prestressed concrete beams and apply a high-strength surface protection. Due to the high architectural and urban significance of the multi-storey parking lot, it was placed under a preservation order during the planning phase of the refurbishment.

Building in partnership with TEAMCONCEPT®

In view of the complexity of the repair measures, the Verheyen office, the client and ZÜBLIN Structural Maintenance joined forces as part of ZÜBLIN's ^{TEAMCONCEPT®} partnership model in order to develop a technologically and economically optimal solution for the project.

To begin with, a comprehensive damage mapping of the entire parking garage was necessary. Due to major concrete spalling and traces of rust on the prestressed concrete beams on the lowest parking level, this level had to be closed. Steel supports had to be installed as a safety measure. The main damage to the parking garage resulted from massive chloride ingress due to a lack of surface protection and the now damaged grouting joints of the prestressed precast girders.

Restoration under monument protection

The ceiling of the lowest parking level had to be almost completely dismantled and replaced. On the other parking levels, only a few ceiling panels had to be replaced. Due to monument protection regulations, the damaged prestressed concrete beams had to be replaced with concrete rather than steel components as planned. As it was not structurally possible to lift an entire prestressed concrete trough slab weighing 18 tons, the decision was made to use a two-part solution: in-situ concrete slab sections produced on site were assembled and installed together with the prefabricated prestressed concrete beams.

In addition, all inward-facing consoles of the parking lot were supported by steel supports and damaged connecting slab elements between the parking lot and the striking elevator tower as well as the parapet elements in the passageway to the elevator were replaced. The elevator tower itself was also completely glazed.