City: Padua (PD)
Type of work: restoration of steel floor for commercial use building
In undertaking the restoration of an important commercial building in Piazzetta Cappellato Pedrocchi in Padua (in front of the iconic Caffé Pedrocchi), the reinforcement of the steel floors became necessary in order to increase the load bearing capacity requirements resulting from the change of use.
Many floors of the building had been built using steel profiles spanned with hollow brick infill, a technique that was very popular during the twenties. Reinforcement of the existing floor was deemed necessary for both the ground and the first level floor due to the increased loads expected with the new commercial activity and the larger customer flow. The least invasive and most effective solution devised was a reinforcement using a connected concrete slab. The upper surface of the IPN type beams was exposed by the removal of the existing floor finish and the screed After ascertaining that the condition of the beams was satisfactory, it was possible to fix the Tecnaria CTF connectors using nailing guns even on the encrusted and partly rusty beams. This is certainly an advantageous factor of a dry connector fixing system: the welding of steel sections would have require a very time-consuming cleaning of the flanges using a grinder. It must also be considered that, quite often, steel produced in the last century often cannot be welded, due to the various heat treatments and high carbon content.
A nylon sheeting was first of all laid on the first floor before casting the slab to prevent percolation of the resulting liquid to the basement floor. This was followed by the installation of an electrowelded mesh.
At first floor level, due to the hardness of the existing screed, the works management were forced into the decision to only make a groove above the beams, rather than expose the upper surface of the joists, on which longer Tecnaria connectors were then installed.