Together with the S&P engineering consultant, the project engineer developed a reinforcement solution that included the use of CFRP laminates for flexural resistance. The S&P C-Anchor in combination with S&P C-Sheets was chosen to counteract the shear forces. In this case, this solution with anchors and carbon fibre fabrics was ideal in several respects:

• The system is corrosion-free and therefore ideally suited to the structure on and above the lake
• The entire works were carried out underneath the slab meaning it was not necessary to cut out any concrete sections to access above the slab

Individual training in advance

The contract to carry out the structural reinforcement works was awarded to Baugeschäft Hüppin AG. Although the building protection specialists already had experience in the application of FRP materials and composites, the S&P C-Anchor and shear reinforcement in this form was also new to them. For this reason, the applicators received individual training at the S&P headquarters in Seewen, Switzerland, a few weeks before the start of the work. This gave them time to learn the tricks of the trade and gain initial experience of working with the system.

Workplace above the water

The workshop created the ideal conditions for the start of the project and an efficient and high-quality application. This was all the more important because scaffolding had to be erected over the lake for the work and the climatic conditions were not ideal: Due to the use of the boat shelter, repairs were only possible during the winter months. Accordingly, the shelter had to be covered and heated so that the temperature and humidity were within the requirements for installation of the materials.

As is typical for S&P, application experts were also on site again at the start of the work to provide support and answer any questions directly on the construction site.

Efficiency with wet-on-wet application

In addition to the usual grinding of the concrete beams and rounding of the edges, the experts drilled a total of 160 holes in the slab at a predefined angle and distance for the S&P C-Anchor. Firstly, they then glued the S&P C-Laminates to the underside of the beams. This was followed by the shear reinforcement, in which first an S&P C-Sheet was installed, then the S&P C-Anchor and finally another S&P C-Sheet on top using the wet-on-wet method.

Finally, the experts applied a bonding bridge made of quartz sand to enable any coatings or paints to be applied later. This procedure is very efficient, but requires good preparation, precise organisation and a well-coordinated team.

Thanks to the professional cooperation of all those involved, the boat shelter was sustainably repaired and adapted to the new structural requirements. It will therefore fulfil its purpose for the boats for many years to come and at the same time fits seamlessly into the new concept for the waterside area in Richterswil.