Construction in Existing Buildings

Project Background

The renovation of underground car parks is becoming increasingly important: Ageing processes in the concrete, moisture and chloride attacks caused by road salt severely affect the structures. Sustainable repairs not only extend the service life of buildings, but also make an important contribution to the conservation of resources. In many cases, preservation is the more economical and environmentally friendly alternative to a new construction.

The challenge

One example is the underground car park under the retirement home in Lossburg in the northern Black Forest, with an area of 450 m². There, the structure was first examined for chloride and corrosion damage. The results showed that the reinforcement in the columns was already heavily affected by advanced corrosion. At the same time, the chloride values in the concrete were well above the permissible limits. The decision was therefore made to comprehensively renovate the underground car park columns.

The solution

TITAN aluminium heavy-duty props were used to safely carry the building load during the work. According to the structural engineer’s specifications, loads of up to 1,000 kN per column had to be supported, depending on the position. Firstly, the damaged concrete was removed using ultra-high-pressure water jets. This was followed by encasing and reconstructing the columns by pouring new concrete and finally applying a protective coating. The adjustable pre-tensioning of the TITAN aluminium heavy-duty props was a decisive advantage during the renovation. This could be precisely controlled via a pressure gauge on the hydraulic spindle jack. This meant that the props, each of which can bear loads of up to 250 kN, could be precisely adapted to the respective columns.

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