ITPD20090304A1 - CASSERO A PERDERE FOR SOLAI WITH HIGH FIRE RESISTANCE - Google Patents

Description

TITLE

DISPOSABLE FORMWORK FOR HIGH RESISTANCE FLOORS

FIRE

DESCRIPTION

This patent relates to disposable formworks for building and in particular concerns a new type of disposable self-supporting formwork in expanded material and with a metal stiffening structure, to create floors and roofs in general in reinforced concrete.

Disposable formworks are known for making floors, as described in patent PD2007A14

Known disposable formworks are elements commonly made of expanded polystyrene, having a generically parallelepiped shape and on the lateral or upper surface of which longitudinal seats are made, suitable for receiving the reinforcement rods for making the reinforced concrete beams of the floor.

These disposable formworks are placed and laid directly on the curbs or on the architraves and must be supported by a temporary structure, in order to create, at the due height, a plane, above which the concrete casting will be carried out for the realization of the attic.

The major advantage resulting from the use of the known disposable formworks consists in the fact that the foam material used for the realization of said formworks, in addition to acting as a formwork during casting, also acts as a thermo-acoustic insulator thanks to the high thermal and acoustic insulation properties of polystyrene.

When using these disposable formworks, it is in any case necessary to place temporary intermediate support structures, commonly called section breakers, which must remain in place at least until the concrete is completely consolidated.

In order to increase their static capacity, the known self-supporting formworks also comprise one or more reinforcing rods or metal sheets, embedded and / or arranged longitudinally within the expanded polystyrene body. Said metal reinforcement has the function of supporting not only the weight of the formwork placed in place, but above all the weight of the reinforcement rods, of the cast concrete and of the workers for the construction of the ribbed floor.

The main task of the present invention is to provide a disposable formwork which, in addition to the functions described above, also solves the important problem of fire resistance, especially when used in buildings with a high potential for fire risk such as garages, warehouses, etc.

These and other direct and complementary purposes are achieved by the new disposable self-supporting formwork for floors and roofs comprising at least one body or element in molded or wire-shaped foam material, preferably polystyrene or polystyrene, with one or more layers of material underneath. with characteristics of good fire resistance, such as refractory concrete or mineral wool, in turn integral with at least one lower bent sheet, with the function of reinforcement and stiffening, finishing and support.

In particular, the new disposable formwork is made starting from a block of expanded polystyrene, from which a series of elements of a parallelepiped shape are obtained by cutting, having multiple widths of the slab module, for example 600 mm, and any modular length, for example 4000 mm.

The blocks in expanded material are shaped flush to make said elements with overlapping and hooking sections and the seats, or half seats, within which to subsequently position the reinforcing rods and cast the concrete for the construction of the floor beams.

An equivalent solution requires that the element in expanded material is obtained, in the optimal and preferred shape, by pre-formed expansion from the mold.

The metal reinforcement is not incorporated into the foam material but is applied by interlocking, after shaping, on the foam element, also incorporating the layer of high fire resistance material. Further advantage is represented by the fact that, since said sheet is applied below the insulating element and the expanded element, it is possible to apply directly any further covering or finishing element, such as plasterboard panels, wood, films, paints, etc., unlike the known disposable formworks , where, in order to apply said cladding elements, it is necessary to identify the appropriate metal plates or inserts incorporated internally in the expanded material body, not visible from the outside, to which the said cladding elements must be anchored with fixing means.

The product obtained is therefore a continuous self-supporting formwork comprising a ribbed and continuous lower sheet, obtained by cold bending or bending, on which the layers of high-quality material are glued consecutively and adjacent to each other. fire resistance to which the aligned foam elements are superimposed, particularly shaped in such a way as to contain in perfect adherence and give stability to the same as the solid polystyrene, of adequate density, prevents the sheet metal in operation from deforming by compression.

The characteristics of the new formwork will be better clarified by the following description with reference to the drawing tables, attached as a non-limiting example.

Figures 1, 2, 3, 4 show various cross sections in the various solutions.

In particular, figure 1 shows the self-supporting flat formwork with central rib (S), for casting the concrete with reinforcement (F), comprising an insulating element in polystyrene (C) a bottom plate (L) with ribs (L2) inserted into the notches present in the body (C) and the intermediate insulating layer (I) formed by a mineral wool mat. Also shown are the lateral joints or overlaps (C10, C11) for the lateral coupling of the formworks and the transverse bars (K).

Figure 2 shows a cross section of the new formwork in the solution with central rib (S) and intermediate insulating layer (I1) formed by a refractory concrete slab.

Figure 3 shows the self-supporting formwork with two half-seats (S1, S2) for the formation of a concrete rib obtained between two elements, comprising a lower sheet (L) with folding and (L2) an insulating element in polystyrene (C) with notches (C2) present in the body (C) and the intermediate insulating layer (I) formed by a mineral wool mat.

Figure 4 shows an element (C) equipped with notches (C2) for the insertion of the ribs (L2) of the lower bearing sheet (L), a transversal through iron (K) for the connection between said insulating element and said ribs of the folded sheet metal (L) and where below said insulating element (C) there is a refractory concrete slab (I1) designed to protect and act as a barrier in case of fire, where flames and heat can damage said lower plate (L). In this way the insulating layer (C) and the load-bearing concrete floor are protected from flames according to the times provided for by the regulations in force.

Figure 5 shows an exploded view of the new formwork comprising an intermediate insulating layer (I, Iâ € ™) placed between the lower bent sheet metal (L) and the upper element (C) in polystyrene.

The new disposable formwork therefore comprises at least one element (C), made of expanded material, generically parallelepiped in shape.

Said elements (C) are made of polystyrene or polystyrene, preferably with a density between 10 and 40 kg / m <3>.

The element (C) in expanded material is a substantially rectangular element with a modular length, for example 4000 mm, and a modular width, for example 600 mm, corresponding to the distance between the beams of the floor to be built.

The element (C) includes a lower surface (C1) for coupling with the layer of fireproof material and with the metal plate (L) of reinforcement and where on said lower surface (C1) seats or cuts are orthogonally obtained (C2 ) for the insertion of the ribs (L2) of at least one ribbed sheet (L), obtained by cold bending of a continuous sheet.

Similarly to the known disposable formworks, one or more seats (S) or half seats (S1, S2) are also obtained on said element (C) which will constitute the seats for the construction of the floor beams.

In particular, it is expected that the element (C) includes the two opposite edges of the protrusions (C4, C5) of such shape that, placing the two elements (C) side by side, said protrusions (C4, C5) are coupled identifying the seat (S) concave inside which the floor beam will be formed.

It can also be envisaged that on said upper surface of the insulating element (C) there are also seats and / or reliefs (C8) for the laying of electro-welded mesh. In particular, it can be foreseen that said upper surface is wavy.

A formwork is therefore obtained, comprising a series of said elements (C) applied consecutively and aligned on said ribbed sheet (L) with an insulating layer interposed, for example in rock wool or mineral wool or in refractory concrete capable of protecting the overlying polystyrene element making the new formwork able to resist fire according to current legislation

To further improve the fire resistance characteristics and prevent the detachment of the lower sheet in the event of a fire, the new disposable formwork is expected to include, inserted transversely through the element (C), a plurality of rods (K, J) in iron, placed at a variable modular distance according to the construction requirements.

Said rods (K) are inserted in the lower part of the element (C) itself so as to be also inserted, in a passing way, in the ribs (L2) of the sheet (L) and protruding, with both ends (K1), laterally by said element (C).

The protruding ends (K1) will then usefully act as a support for the reinforcing bars of the beam subsequently placed in the seat (S).

This expedient has multiple functions, including that of making the entire metal structure integral with all the related stable applications of the reinforced concrete structure subsequently created.

This device also has the function of favoring collaboration between the beams cast on site and of creating a reticular floor without thermal bridges. A further function of these rods (K) is to create a support for the metal reinforcement (F) of each joist, to allow the casting of a concrete cover of adequate thickness.

Not the least function of these rods (J) is to avoid the risk of collapse of the ceiling in case of fire, as they are anchored to the concrete joists. In fact, in the case of self-supporting formwork with a lower layer in refractory concrete, it is possible to provide a specific additional reinforcement (J) incorporated in said layer (Iâ € ™); said reinforcement (J) comprises a series of rods or rods passing through the folds (L2) and embedded in said layer (J) of concrete. In this way, in the event of detachment of the lower part of the sheet (L) subjected to heat, the concrete layer will remain integral with the insulating element (C) thanks to said auxiliary reinforcement (J).

It is also possible to provide that one or more cladding and finishing panels, such as plasterboard panels, wood, wood-type paper films, or other, are applied directly to said lower folded sheet (L).

It is also possible to provide that said sheet (L), preferably of the galvanized type, is for example painted and / or treated with fireproof material or other types of products.

The metal reinforcement of this type of self-supporting disposable formwork, formed by said ribbed sheet, also has the advantage of being able to support false ceilings, thermo-hydraulic and / or electrical systems, pipes of various kinds, and other small and medium-sized ones. loads, as it is bound, by means of said rods (K, J), to the reinforced floor above.

These are the schematic modalities sufficient for the skilled person to realize the invention, consequently, in concrete application there may be variations without prejudice to the substance of the innovative concept.

Therefore, with reference to the above description and the attached tables, the following claims are expressed.

Claims (1)

CLAIMS 1.Cases to lose for floors, comprising - at least one element in expanded material (C) with seats (S) and / or lateral semi-seats (S1, S2) within which to lay the reinforcement rods and cast the concrete of the reinforced beams of the floor, one or more elements (C), or part of elements (C), in shaped foam material, having a modular width and a substantially rectangular plan, and comprising, obtained on their lower coupling surface (C1), one or more seats or cuts (C2); - at least one continuous ribbed sheet (L) located below said element (C), comprising at least one flat surface (L1) for coupling with part or all of said lower surface (C1) of said element (C) and one or more ribs (L2) designed to be inserted into said seats or cuts (C2) of element (C) and to collaborate within the reach of the formwork itself; characterized in that it comprises at least one further insulating material layer capable of resisting fire interposed between said sheet and said expanded material and where said sheet (L) and / or said element (s) (C), coupled together in a way integral, they include correspondingly shaped side edges for the hermetic junction between side-by-side formworks. 2. Disposable casings, according to claims 1, characterized in that said layer of high fire resistance material comprises a mineral wool, glass wool mat. 3. Disposable casings, as per claims 1, 2 characterized in that said layer of high fire-resistant material comprises at least a layer of refractory concrete or concrete in general. 4.Case to lose, as per claims 1, 2, characterized in that they comprise one or more metal rods (K) inserted transversely into the lower part of said element (C) and, passing through, into said ribs (L2) of said sheet (L) and where each of said rods (K), protruding at least in part from said element (C), acts as a support for the main reinforcement rods (F) laid within said seats (S) or half seats (S1 , S2). 5. Disposable boxes, as per claims 1,2,3,4, characterized by the fact that they comprise one or more further metal rods (J) inserted in the fire protection layer (J) and, transversely and passing through, in said ribs (L2) of said sheet (L) 6. Disposable, as per the preceding claims, characterized in that they comprise one or more projections or seats (C10, C11) obtained laterally to said expanded element (C), in correspondence with said half seats (S1, S2). 7. Non-returnable, as per the previous claims, characterized in that it is obtained by coupling, by gluing, one or more of said elements (C), aligned and consecutive, with a further insulating layer (J) and at least a continuous ribbed sheet (L) and the subsequent cut, in the appropriate length, of the continuous formwork obtained. 8. Cassero to lose, as per the previous claims, characterized by the fact that said sheet (L) is treated with fireproof products, such as plasters, finishing mortars, fibrous conglomerates. 9. Disposable formwork, as per the preceding claims, characterized in that it comprises one or more layers of finishing coating applied underneath said folded sheet (L) coupled to said element (C).