Concrete repair work in Olten

Shotcrete is being applied

The work on the pedestrian gallery, directly on Aarburgerstrasse, was straightforward but also very varied. Various structural defects had weakened the structure, as there were localised defects caused by rusty steel or spalling concrete. The concrete on the columns was removed using high-pressure water jets at 2,500 bar and exposed for recasting. Scaffolding supported temporary shoring to allow treated areas to be refilled with sprayed mortar. The steel was first sandblasted and then coated with a corrosion inhibitor – rust protection – before being sprayed with new mortar using a mortar pump. The columns were subsequently formworked and filled with cast mortar.

What would a construction site be without a challenge?

Right at the start of the project, it became clear that the struts intended to support the weak spots could not simply be placed on the surface due to the heavy load. Consequently, the load had to be distributed across temporary foundations. As work was carried out using a high-pressure water jet, protective measures had to be put in place on site. This took the form of scaffolding tarpaulins to ensure that no damage could be caused by flying stones or other debris. The location of the site also presented its own challenges. The adjacent main road is very busy. Fortunately, one traffic lane is reserved for buses, and this could be cordoned off for the construction site. In general, heavily used roads or bridges are complex to renovate. The work often disrupts traffic and generates emissions, such as flying debris or dust. The surrounding area must always be protected from this. Thanks to their experience and expertise, the professionals at ERNE mastered these challenges with flying colours.