Description
In the course of this renovation project, memory^®-steel ribbed rebars were used as a strengthening system.

A concrete downstand beam was subsequently built on the underside of the ceiling as a bending reinforcement. For this installation, a clean substrate preparation is key. A few centimetres of the concrete were removed in layers by lateral point hammering. Subsequent sandblasting cleaned the substrate and removed loose aggregates. re-bar 16 were then installed, anchored, and prestressed before being fully embedded in the spray mortar. This increased the load-bearing capacity in flexure in this section of the ceiling and reduced future deflections.

Minor deficits in punching shear resistance were identified on the upper side of the ceiling. Slotted re-bars were used here in the grouting mortar. Further bending reinforcement was achieved with CFRP laminates.

Advantages:

• High ductility of the additional reinforcement
• Active tensile reinforcement (after activation at a similar stress level as existing reinforcement)
• Easy to apply reinforcement with prestressing without the need for complex tensioning equipment (presses) and anchor heads
• Fire and corrosion protection through concrete/mortar covering
• High situational adaptability of the reinforcement system

Products
memory^®-steel re-bar 10 & 16, Sika MonoTop^®-4012, SikaGrout^®-314 N, Sika CarboDur^® S