Page 27 - Reinforced concrete voided slabs subjected to gravity and seismic actions

The U-Boot Beton® hollow fillers allow the construction of voided reinforced concrete floors cast in situ, consisting of a grid of mutually orthogonal ribs closed above and be- low by a continuous slab. The double slab ensures collaboration between the orthogonal ribs and provides adequate torsional stiffness to the sections of the floor, thus obtaining a bi-directional transfer mechanism of the transverse loads. Connections with vertical resistant elements of the structure (columns, shear walls) are achieved through solid cast areas of variable amplitude depending on the extent of the stresses expected.The individual filers have a pyramid trunk shape, a square base of side equal to 52 cm and heights ranging between 10 and 28 cm. If necessary, the individual modules may be assembled in such a way as to obtain voids of an overall greater height (figure 1.15). The legs, of standard variable height between 5 and 10 cm (up to 20 cm on request), determine the thickness of the bottom slab and ensure that the lightenings can be placed directly on a standard formwork. The ribs have variable widths, typically between 10 and 30 cm, resulting in rib spacing between 62 and 82 cm.The different stages of creation of a floor are schematically represented in the figures below. After having created a standard formwork on the entire surface of the structure, the lower reinforcement bars and the bent bars or connecting hooks are installed. Then the fillers are positioned on the plane of the formwork together with the upper rein- forcement bars. Correct positioning in the plan is ensured by means of suitable spacer couplings.The concrete casting is performed in two phases in order to prevent flotation of the lightenings. First a height equal to that of the leg or above this by a few centimetres is filled (constitution of the lower slab). As soon as the concrete “begins to set” completion of the casting can be undertaken.27 Structural typology description§cap 11.3. Description of the constructive systemFiFgiugruere1.1.61.6L.aPyoinsgaocafsfosremrawtuorakup © Dalifoform Group © Daliform Grouup © Daliform Group © Daliform Group © Dalifoform Group © Daliform Group © Daliform Group © Daliform Grouup © Daliform Group © Daliform Group © Daliform Group © Daliform Group © Dalifoform Group © Daliform Group © Daliform Group © Daliform Group © Daliform Group © Daliform Grouup © Daliform Group © Daliform Group © Daliform Group © Daliform Group © Daliform Group © Daliform Group © Dalifoform Group © Daliform Group © Daliform Group © Daliform Group © Daliform Group © Daliform Group © Daliform Group © Daliform Grouup © Daliform Group © Daliform Group © Daliform Group © Daliform Group © Daliform Group © Daliform Group © Daliform Group © Dalifo form Group © Daliform Group © Daliform Group © Daliform Group © Daliform Group © Daliform Group © Daliform Group © Daliform Grou© Daliform Group © Daliform Group © Daliform Group © Daliform Group © Daliform Group © Daliform Group © Daliform Group © Dalifo iform Group © Daliform Group © Daliform Group © Daliform Group © Daliform Group © Daliform Group © Daliform Grouup © Daliform Group © Daliform Group © Daliform Group © Daliform Group © Daliform Group © Dalifo form Group © Daliform Group © Daliform Group © Daliform Group © Daliform Grouup © Daliform Group © Daliform Group © Daliform Group © Dalifoform Group © Daliform Group © Daliform Grouup © Daliform Group © Dalif form Grou