Prefabricated slab for constructing a cantilevered structural element and prefabricated structure

Abstract

A prefabricated slab (1) for forming a cantilevered structural element in a prefabricated structure (9) comprises a slab body (10) made in a single prefabricated piece. The slab body (10) extends between a connection end (11) and a free end (12) in a cantilevered direction (Z). The slab body (10) comprises: an internal structural portion (101) made of reinforced concrete proximal to the connection end (11), an external structural portion (102) made of reinforced concrete proximal to the free end (12), and an interposed insulating portion (103). The insulating portion (103) extends predominantly on a thermal break plane (T) orthogonal to the cantilevered direction (Z) and is made of an insulating material having structural mechanical properties such as to contribute to the strength of the prefabricated slab (1). A prefabricated structure (9) comprises the prefabricated slab (1).

Description

Field of application

[0001] The present invention relates to a prefabricated slab and a prefabricated structure comprising the prefabricated slab.

[0002] More in general, the present invention belongs to the field of prefabricated constructions.

[0003] The installation of cantilevered structures, e.g, such as balconies, hanging terraces, roofs and canopies, eaves, parapets or brise-soleil, suspended walkways, or carports, is often required in constructions.

[0004] These cantilevered structures may have structural, aesthetic, or practical functions, and are constructed from materials such as concrete, steel, wood, or composite materials, depending on the design requirements.

[0005] These cantilevered structures are generally poured on-site, i.e. directly at the construction site, by means of formwork and in-situ pours of reinforced concrete. In this manner, the reinforcement of the cantilever is positioned and fastened on site, and the concrete is poured in-situ.

[0006] This solution is particularly used for customized projects and when ensuring a high integration with the load-bearing structure of the building is desired.

[0007] Disadvantageously, this solution requires long construction times; the construction process includes assembling the formwork, pouring the concrete, curing the concrete, and stripping, making the method long and costly, because it requires intensive use of skilled labor, temporary materials, such as formwork, and equipment for temporary support, which determine an increase in overall costs.

[0008] Furthermore, in-situ construction requires detailed planning of high logistical and implementation complexity and the use of specific formwork to ensure precision and structural quality.

[0009] According to a further disadvantage, the main structure of the building is often configured to receive cantilevers only on two opposite sides of the structure and does not allow the free design of cantilevers along the entire perimeter of the building, to the detriment of design freedom.

[0010] According to a further disadvantage, in-situ operations may be subject to significant delays due to adverse weather conditions, such as rain or extreme temperatures, which affect the placement and curing of concrete.

[0011] A yet further disadvantage is represented by the difficulty of quality control: constructing complex elements in-situ may lead to irregularities or imperfections which are difficult to correct at a later time, affecting the appearance and the structural performance of the building.

[0012] Furthermore, disadvantageously, this solution has a substantial logistical impact; the need to store materials and equipment at the construction site may increase the footprint and reduce the general efficiency of the construction site.

[0013] These disadvantages make prefabricated solutions more advantageous in many contexts, especially when seeking to reduce times and costs while maintaining optimal quality control.

[0014] During the last decade, cantilevered elements manufactured in a plant as prefabricated elements made of reinforced or prestressed concrete have been developed. These elements are then transported to the construction site and fastened to the main structure by means of mechanical connections. Generally, these elements are fastened to the beams of the main structure.

[0015] Therefore, disadvantageously, in these cases the positioning of the cantilevered elements is constrained by the position of the beams themselves, i.e. the design freedom is limited by the presence of the beams.

[0016] This construction constraint also affects the quality and appearance of low-end buildings for affordable housing, which are often constructed without balconies or canopies for cost containment requirements.

[0017] Furthermore, particular attention must be paid to proper insulation to avoid thermal bridges at the connection points between the cantilever and the load-bearing structure.Summary of the invention

[0018] Therefore, the need is strongly felt to provide a prefabricated slab and a prefabricated structure capable of overcoming the typical drawbacks of the prior art.

[0019] In particular, it is the object of the present invention to provide a solution which makes it possible to construct cantilevered elements on all sides of the prefabricated structure and with great design flexibility.

[0020] It is a further object of the present invention to provide a solution which eliminates thermal bridges in the structure and which integrates the insulation into the structure itself without requiring further insulating systems.

[0021] This need is satisfied by a prefabricated slab and a prefabricated structure according to the independent claims. The dependent claims describe preferred or advantageous embodiments of the invention implying further advantageous aspects.Description of the drawings

[0022] Further features and advantages of the prefabricated slab according to the invention will become apparent from the following description of some preferred exemplary embodiments, given by way of non-limiting indication, with reference to the accompanying drawings, in which: figure 1 shows a perspective view of a prefabricated slab according to an embodiment of the present invention; figure 2 shows a perspective view of a prefabricated slab according to an embodiment of the present invention; figure 3 is a diagrammatic cross-section view of a prefabricated slab in an embodiment of the present invention, with the lateral cavities left empty; figure 4 shows a perspective view of a prefabricated slab according to an embodiment of the present invention; figure 5a shows a perspective view of a prefabricated slab according to an embodiment of the present invention; figure 5b shows a perspective view of an insulating portion extracted from the remaining slab body of the prefabricated slab in figure 5a; figure 6a shows a perspective view of a prefabricated slab according to an embodiment of the present invention, in a difference perspective from that of figure 5a; figure 6b shows a perspective view of an insulating portion extracted from the remaining slab body of the prefabricated slab in figure 6a; figure 7 is a perspective view which shows the connection between a prefabricated slab and a prefabricated wall according to an embodiment of the present invention; figure 8a is a detailed longitudinal section view, with a plane taken along the central rib of the prefabricated slab, of the resting between the prefabricated slab according to the present invention and a prefabricated wall in an embodiment of the invention; figure 8b is a longitudinal section view, with a plane taken along the wings of the prefabricated slab, of the resting between a prefabricated slab according to the present invention and a prefabricated wall in an embodiment of the invention; figure 9 is a perspective view which shows the connection between a prefabricated slab, an internal slab placed orthogonally, and a prefabricated wall according to an embodiment of the present invention; figure 10 is a detailed longitudinal section view, with a plane taken along the central rib of the prefabricated slab, of the resting between the prefabricated slab according to the present invention, an internal slab placed orthogonally, and a prefabricated wall in an embodiment of the invention; figure 11 is a perspective view which shows the connection between a prefabricated slab and an internal slab placed orthogonally, isolated from a prefabricated structure, in an embodiment of the present invention; figure 12 is a perspective detail view of a connection end of a prefabricated slab in an embodiment of the present invention; figure 13 is a perspective view of a prefabricated slab according to an embodiment of the present invention; figure 14a is a detailed perspective view of a prefabricated slab in an embodiment of the present invention, in which the connection with a group of systems originating from a prefabricated module is shown; figure 14b is a side view of the detail of figure 14a; figure 15 is a perspective view which shows the resting of two adjacent prefabricated slabs on successive prefabricated walls, in an embodiment of the present invention; figure 16 is a perspective view showing a prefabricated structure according to an embodiment of the present invention; figure 17 is a perspective view of a formwork in an embodiment of the present invention. Detailed description

[0023] With reference to the aforesaid figures, reference numeral 1, as a whole, indicates a prefabricated slab for the construction of a cantilevered structural element in a prefabricated structure 9, e.g., a balcony or a canopy.

[0024] The prefabricated slab 1 comprises a slab body 10 made of a single prefabricated piece, which extends between a connection end 11 and a free end 12 in a cantilevered direction Z.

[0025] In the present disclosure, the expression "single prefabricated piece" means that the parts, described below, are not mechanically connected in a dry manner, but that the slab body 10 is formed directly in one single piece in which the parts are directly integrated in the step of pouring. Preferably the only mechanical connection between the parts is provided by prestressing strands and possibly by further ordinary reinforcement systems, e.g., meshes, in any case all integrated during the step of pouring of the slab body itself.

[0026] The slab body 10 comprises an internal structural portion 101, an external structural portion 102 and an intermediate insulating portion 103.

[0027] The internal structural portion 101 is made of reinforced concrete and is proximal to the connection end 11. The internal structural portion 101 is adapted to lie inside the prefabricated structure 9.

[0028] The external structural portion 102 is made of reinforced concrete and is proximal to the connection end 12. The external structural portion 102 is adapted to protrude externally from a prefabricated wall 90 of the prefabricated structure 9;

[0029] The insulating portion 103 is interposed between the internal structural portion 101 and the external structural portion 102.

[0030] In other words, in the cantilevered direction Z, from the connection end 11 to the free end 12, there are, in order, the internal structural portion 101, the insulating portion 103 and the external structural portion 102.

[0031] The insulating portion 103 extends mainly in a thermal break plane T orthogonal to the cantilevered direction Z and is made of an insulating material having structural mechanical properties such as to contribute to the strength of the slab 1.

[0032] The expression "structural mechanical properties" means that the insulating material does not exclusively perform a thermo-acoustic insulation function, but is configured to act as a collaborating element of the slab.

[0033] For example, preferably, the material has values of compressive strength and rigidity such as to distribute the vertical loads and / or to contribute to the flexural stability of the entire section of the slab, reducing the deformations under static and dynamic load.

[0034] Preferably, the aforesaid insulating material has a modulus of elasticity E and a compressive strength which may cooperate with those of the adjacent load-bearing materials, allowing an effective transfer of shear stresses at the interface. This prevents the material from undergoing localized yielding or crushing phenomena that would compromise the structural integrity of the slab 1 over time.

[0035] More specifically, the structural properties of the insulating material permit the formation of a composite section, in which the insulating material acts in synergy with the other components (e.g., concrete or steel elements). The synergy is guaranteed by an intrinsic strength of the material which prevents the relative sliding between the layers, thus actively participating in the overall moment of inertia of the structure.

[0036] In a preferred embodiment, the insulating material is a material having of low thermal transmittance and high structural mechanical properties.

[0037] Preferably, the insulating portion 103 is made of a wood-based structural material.

[0038] In an advantageous embodiment, the insulating portion 103 is made of veneered plywood for technical construction applications, for example laminated veneer lumber (technically known as LVL - Laminated Veneer Lumber), for example the material known by the trade name Kerto ®< , or of glued laminated timber.

[0039] Preferably, the insulating material is characterized by an elastic modulus E greater than or equal to 10 kN / mm2.

[0040] According to an embodiment, the insulating portion 103 is made of a material characterized by a bending strength equal to 70 MPa calculated according to EN 408 standard.

[0041] According to an embodiment, the insulating portion 103 is made of a laminated material characterized by a modulus of elasticity E90, mean perpendicular to the grain of the veneers equal to 470 MPa, calculated according to standard EN 14374.

[0042] In an embodiment, the insulating portion 103 is made of a material characterized by compressive strength perpendicular to the grain of the veneers between 8 MPa and 11 MPa, preferably equal to 8.5 MPa or to 10.2 MPa, calculated according to standards EN 384 and EAD 130010-0304.

[0043] In an embodiment, the insulating portion 103 is made of a material characterized by a shear strength value equal to about 4.0 MPa, calculated according to standard EN 408.

[0044] Preferably, the insulating portion 103 is resistant to a shear load in the vertical direction, i.e., in the transverse direction Y orthogonal to the cantilevered direction Z, greater than 4,000 kg per linear meter in the longitudinal direction X, even more preferably greater than 5,000 kg per linear meter in the longitudinal direction X.

[0045] Preferably, the insulating portion 103 is resistant to a bending moment greater than 7,000 kgm per linear meter in the longitudinal direction X.

[0046] In an embodiment, the insulating portion 103 has the same cross-section, parallel to the thermal break plane T, as the external structural portion 102.

[0047] In an advantageous embodiment, the insulating portion 103 is a plate-like element extending mainly in the thermal break plane T, embedded in the slab body 10 in the step of pouring of the internal 101 and external 102 structural portions, so that the slab body 10 is a single prefabricated piece.

[0048] In an advantageous embodiment, the insulating portion 103 extends mainly in a longitudinal direction X and in a transverse direction Y, which identify the thermal break plane T, and has a reduced thickness in the cantilevered direction Z.

[0049] In an advantageous embodiment, the insulating portion 103 extends in the cantilevered direction with a thickness K equal to 16 cm, independently of the dimensions of the internal structural portion 101 and / or of the external structural portion 102.

[0050] In an advantageous embodiment, the slab body 10 extends in a transverse direction Y orthogonal to the cantilevered direction Z between a first upper wing 24 and a second lower wing 26 and has a longitudinal rib 2, or web, which connects said first wing 24 and said second wing 26, mainly extending along the cantilevered direction Z between the connection end 11 and the free end 12, so that two lateral cavities 41, 42 are formed between the first wing 24 and the second wing 26, i.e., the slab body 10 has a sideways H-shaped cross-section, parallel to the thermal break plane T.

[0051] In other words, having defined the transverse direction Y orthogonal to the cantilevered direction Z and the longitudinal direction X orthogonal to the cantilevered direction Z and to the transverse direction Y, this embodiment the slab body 10 is in the shape of a girder with a height in the transverse direction Y much smaller than the extension of the wings 24, 26 in the longitudinal direction X and in the cantilevered direction Z.

[0052] The sideways H-shaped cross-section configuration is not only a good solution to the weight reduction requirements, but is instrumental to the optimization of the internal lever arm in the stress diagram of the slab. The wings maximize the moment of inertia of the section with the minimum use of material, while the central rib guarantees shear strength and torsional stability during the steps of handling and assembly.

[0053] In the technical jargon of the sector, the wing is also known as flange and the central rib is also known as web.

[0054] Preferably the central rib 2 extends along the entire length of the slab body 10 in the cantilevered direction Z.

[0055] The lateral cavities 41, 42 are thus delimited on one side by the central rib and, superiorly and inferiorly, by said first and second wing 24, 26. These cavities are instead open and accessible in the cantilevered direction Z and at least in one sense in the longitudinal direction X.

[0056] In other words, the first wing 24, when the prefabricated slab is in use, is adapted to construct a walkable surface, e.g., in a prefabricated slab, and the second wing 26, when the prefabricated slab is in use, is adapted to face toward a ceiling surface of an underlying environment, e.g., of an underlying prefabricated module, or to directly construct the ceiling of the environment, preferably of a prefabricated module.

[0057] In a preferred embodiment, the first wing 24 has a variable thickness in the transverse direction Y.

[0058] In particular, the first wing 24 is symmetrical with respect to the central rib 2 and extends between a distal end with respect to the central rib 2, with a first thickness S1, and a portion proximal to the central rib 2, with a second thickness S2, with a constant slope, inclined toward the first lateral cavity 41.

[0059] Preferably, the first thickness S1 is between 5 and 9 cm, preferably equal to 7 cm, and the second thickness S2 is between 7 and 10 cm, preferably equal to 9 cm.

[0060] In an embodiment, the second wing 26 has a constant third thickness S3 for a first length L1. Preferably said third thickness is comprised between 4 and 7 cm, more preferably equal to 5 cm.

[0061] Preferably the length L1 is comprised between 40 and 70 cm, more preferably equal to 60 cm.

[0062] In an embodiment, the fourth thickness S4 of the second wing 26 close to the central rib 2 is comprised between 5 and 9 cm, more preferably equal to 7 cm.

[0063] In an embodiment, at the distal end from the central rib 2, the second wing 26 has a third thickness S3 comprised between 4 and 7 cm, more preferably equal to 5 cm.

[0064] In other words, the lateral cavities 41, 42 are at least partially characterized by a certain taper towards the central rib, adapted to facilitate the operations of extracting the manufactured item from the formwork and to reinforce the central load-bearing portion of the slab.

[0065] In an embodiment, the central rib 2 extends in the longitudinal direction X for a second length L2 comprised between 40 and 70 cm, more preferably equal to 50 cm or 60 cm.

[0066] Advantageously, in these embodiments, the operation of extracting the prefabricated slab from a formwork for its construction is facilitated.

[0067] Advantageously, providing a central rib 2 of significant size, e.g, in variants in which it extends for a second length L2 between 40 and 70 cm and, in an optimal manner, when the length L2 is equal to 50 cm or 60 cm in the longitudinal direction, makes it possible to manufacture a prefabricated slab 1 extending in the longitudinal direction X up to 3 m, without requiring additional ribs between the first wing 24 and the second wing 25.

[0068] This is particularly advantageous because the prefabricated slab 1 is thereby adapted to be used as a base of a prefabricated module.

[0069] In an embodiment, the slab body 10 extends in the longitudinal direction X for a length L between 1.80 m and 3 m.

[0070] Consequently the prefabricated slab allows efficient assembly and industrialization, especially in the form in which it integrates a prefabricated module.

[0071] In an advantageous embodiment, the longitudinal rib 2 is free of lightening voids, i.e. it is solid reinforced concrete.

[0072] Advantageously, such an embodiment gives a high strength also to torsional loads to the prefabricated slab.

[0073] In an embodiment, the prefabricated slab 1 comprises prestressing strands 900 extending in the cantilevered direction Z and passing through the insulating portion 103.

[0074] Preferably, said prestressing strands 900 are at least partially sheathed.

[0075] Advantageously, the passage of the prestressing strands through the insulating portion serves the dual function of absorbing the tensile stresses resulting from the bending moment of the cantilever and of maintaining the insulating portion in a state of permanent compression between the internal portion and the external portion.

[0076] In a particularly advantageous embodiment, the insulating portion 103 has a first indentation 240 at the first wing 24, on the side of the external portion 102, and a second indentation 260 at the second wing 26, on the side of the internal portion 101.

[0077] Furthermore, according to this embodiment, the external portion 102 comprises a first protrusion 124 in the cantilever direction Z facing the insulating portion 103 and engaging said first indentation 240 and the internal portion 101 comprises a second protrusion 126 in the cantilever direction Z facing the insulating portion 103 and engaging said second indentation 260, so as to transfer the shear stresses resulting from the loads resting on said external portion 102 to the internal portion 101.

[0078] In this embodiment, advantageously, the structural performance of the slab is further improved, so that any loads acting on the cantilevered portion are transferred to the portion resting on a support structure, e.g., such as a prefabricated beam or a prefabricated wall like the one that will be defined in the remainder of the discussion.

[0079] It is apparent that the engagement between the protrusions 124, 126 and the respective indentations 240, 260 is not a mechanical engagement, but also such engagement is made in the step of pouring, i.e., the concrete in the step of pouring also occupies said indentations.

[0080] Advantageously, these indentations 240, 260 and protrusions 124, 126 serve as true and proper mechanical shear keys. They constrain the flow of stresses to follow a path which engages the insulating material not only by surface adhesion, but by direct compression of the edges of concrete against the insulating material itself, drastically increasing the ultimate load capacity of the connection system.

[0081] In an embodiment, the prefabricated slab 1 further comprises a connection element 3 which protrudes from the connection end 11 of the slab body 10 in the cantilevered direction Z, suitable for generating the structural connection with an internal slab 1' in the prefabricated structure 9, placed orthogonally with respect to said prefabricated slab 1.

[0082] In an embodiment, the connection element 3 is a metal element and comprises one or more metal girders 30 mechanically connected to the longitudinal rib 2 at the connection end 11.

[0083] In an alternative embodiment, the connection element 3 is a protruding extension 300 of the central rib 2 in the cantilevered direction Z, integral with the internal structural portion 101. Preferably, the protruding extension 300 is tapered at the free end to facilitate the connection in the lateral cavities 41, 42 of the internal slab 1' placed perpendicularly with respect to the prefabricated slab 1.

[0084] In an embodiment, the prefabricated slab 1 comprises an auxiliary insulating element 105, 106 which fills the lateral cavities 41, 42 in the insulating portion 103 of the slab body 10.

[0085] In an advantageous embodiment, the auxiliary insulating element 105, 106 is of the same material as the insulating portion 103.

[0086] In an alternative embodiment, the auxiliary insulating element 105, 106 is of a different material having insulating and optionally also structural properties.

[0087] In a further embodiment the prefabricated slab 1 further comprises insulating elements 107 added to the auxiliary insulating element 105, 106 to further fill said cavities in the insulating portion.

[0088] Preferably the auxiliary insulating element 105, 106 and optionally the further insulating elements 107 are inserted into the cavities 41, 42 at a later time with respect to the pour and are fastened, e.g., by adhesive means.

[0089] It is clear that such auxiliary insulating elements and insulation elements preferably leave the cavities 41, 42 free at the internal structural portion 101 and external structural portion 102.

[0090] It is a further object of the present invention a prefabricated structure 9 comprising a prefabricated slab 1 in an embodiment of the present invention.

[0091] In an embodiment, the prefabricated structure 9 comprises a prefabricated wall 90 which extends mainly in a longitudinal direction X and in a transverse direction Y which identify a plane orthogonal to the cantilevered direction Z and which comprises a structural body 6 and an insulating panel 7 which covers an external wall of said structural body 6 identifying an insulating wall plane P.

[0092] In this embodiment, the prefabricated slab 1 is resting on the prefabricated wall 90 so that the insulating portion 103 is at least partially in continuity with the insulating panel 7 in the transverse direction Y, i.e., preferably, that the thermal break plane T is coincident with the wall insulating plane P, and that the external structural portion 102 protrudes in cantilever with respect to the prefabricated wall 90.

[0093] In other words, in the structural connection between the prefabricated slab 1 and the wall, the insulating portion 103 is at least partially coplanar with the insulating panel 7 of the wall of the structure.

[0094] In an advantageous embodiment, the structural body 6 of the prefabricated wall 90 is made in a single pour of reinforced concrete, comprising an upper beam 62 and a non-load-bearing lower wall element 64. The beam 62 entirely supports the vertical loads acting on the prefabricated wall 90 and is of greater thickness in the cantilevered direction Z with respect to the lower wall element 64.

[0095] In an embodiment, the prefabricated structure 9 also comprises columns along the transverse direction Y and optionally beams along the longitudinal direction X and / or along the cantilevered direction Z.

[0096] It is a further object of the present invention, in itself, a prefabricated wall 90 which extends mainly in a longitudinal direction X and in a transverse direction Y, defining a wall plane P. The prefabricated wall comprises a structural body 6 made from a single reinforced concrete pour comprising an upper beam 62 and a lower, non-load-bearing wall element 64, wherein the beam 62 is suitable for entirely supporting the vertical loads bearing on the prefabricated wall 90 and is thicker than the lower wall element 64 in a direction orthogonal to the wall plane P.

[0097] In an embodiment, the upper beam 62 has a beam thickness in the cantilevered direction Z between 25 and 30 cm, and the lower wall 64 has a wall thickness in the cantilevered direction Z between 8 and 10 cm.

[0098] Thus, the lower wall 64 substantially has an infill function, and it is possible to form openings substantially over its entire extension without affecting the load-bearing feature of the system.

[0099] In an embodiment, the upper beam 62 is more reinforced with respect to the lower wall element 64.

[0100] Preferably, the upper beam 62 is of reinforced concrete with 150 kg / m3 of steel, and the lower wall element 64 is of reinforced concrete with 20 kg / m3 of steel.

[0101] In an embodiment, the reinforcement of the upper beam 62 is a steel girder embedded in the concrete, extending in the longitudinal direction X.

[0102] In an embodiment, the prefabricated slab 1 rests on the prefabricated wall 90 by bearing of the second wing 26 on the upper beam 62.

[0103] In an embodiment, the first wing 24 protrudes in the cantilevered direction Z with respect to the second wing 26, i.e. extends with a greater length in said cantilevered direction Z, and the prefabricated slab 1 rests on the prefabricated wall 90 by bearing of the first wing 24 on the upper beam 62.

[0104] In an embodiment, the prefabricated structure 9 comprises an internal floor slab 1' having the same shape as the prefabricated slab 1 and being arranged perpendicular to the prefabricated slab 1. In other words, the internal slab 1' is also sideways H-shaped.

[0105] I.e., the internal slab 1' comprises a first wing 24' and a second wing 26' and a longitudinal rib 2' which extends mainly along a longitudinal direction X orthogonal to the cantilevered direction Z and which connects said first wing 24' and said second wing 26', so that between the first wing 24' and the second wing 26' two lateral cavities 41', 42' are formed.

[0106] In an embodiment, the internal slab 1' lies entirely within the prefabricated structure 9 and is free from an insulating portion. In other words, the internal slab 1' is entirely an internal structural portion 101.

[0107] In an embodiment, the connection element 3 protruding from the slab body 10 at the connection end 11 is inserted into one of said lateral cavities 41', 42' of the internal slab 1' to structurally constrain said prefabricated slab to said internal slab 1'.

[0108] In an embodiment, further fastening means, such as bolts or flanged connections, are provided between the connection element 3 and the internal slab 1'.

[0109] Preferably, the internal slab 1' rests on a beam or on a prefabricated wall 90 like the one described.

[0110] In an embodiment, the prefabricated structure 9 comprises a prefabricated module delimited superiorly by a ceiling wall 80, arranged parallel in a lowered position with respect to the second wing 26 of the prefabricated slab 1. A gap 600 is formed between the ceiling wall 80 of the prefabricated module and said second wing 26.

[0111] The prefabricated structure 9 comprises systems 8 or piping for the supply of said prefabricated module, housed in said gap 600. The second wing 26 is perforated and allows the passage of pipes 800 or cables originating from said systems 8, and to facilitate their outlet towards the outside through the lateral cavities 41, 42.

[0112] In an embodiment, the second wing 26 comprises a plurality of holes 85.

[0113] In an embodiment, the central rib 2 also has a plurality of passage holes 87. Preferably, the passage holes 87 are made so as to generate a lip 870 on the first wing 24, facing toward the lateral cavities 41, 42.

[0114] It is also the object of the present invention a formwork 5 for the construction of a prefabricated slab 1.

[0115] In an embodiment, the formwork 5 comprises a formwork base 50 which extends in a horizontal plane and is adapted to receive a concrete pour.

[0116] In an embodiment, the formwork 5 further comprises pair of infill elements 51, 52 adapted to be positioned with respect to the formwork base 50 to occupy the space intended for making the lateral cavities 41, 42.

[0117] In an advantageous embodiment, the formwork 5 comprises an insulating panel placed transversely to the formwork base 50 and adapted to be embedded in the concrete casting to make a prefabricated slab 1 comprising an insulating portion 103.

[0118] Preferably, further prestressing systems are provided in the formwork 5, such as ordinary strands or reinforcements, adapted to reinforce the concrete.

[0119] It is a further object of the present invention a production method of a prefabricated slab 1 according to the present invention, which comprises the following steps: a) providing a formwork 5 according to the present invention; b) pouring concrete to form the precast slab 1.

[0120] In a preferred embodiment, step a) further comprises a sub-step a2) of preparing an insulating panel transversely to the formwork base 50 intended to form the insulating portion 103 and step b) provides pouring concrete to form the internal structural portion 101 and the external structural portion 102, embedding said insulating panel forming a single prefabricated piece in the pouring.

[0121] Innovatively, the present invention solves the drawbacks of the prefabricated structures typical of the prior art.

[0122] Advantageously, the prefabricated slab according to the invention allows a freer and more flexible design of the prefabricated structure.

[0123] According to a further advantage, the prefabricated slab makes it possible to achieve structural cantilevered elements, while maintaining a continuous insulation of the wall of the building.

[0124] According to a further advantage, the prefabricated slab allows cantilevered elements to be applied along the entire perimeter of a prefabricated structure, and therefore ensures excellent design freedom.

[0125] According to a still further advantage, the prefabricated slab is of simple installation and connection with prefabricated slabs placed orthogonally respect thereto, by virtue of the innovative sideways H shape.

[0126] According to a yet further advantage, the sideways H shape allows further application and production freedoms, e.g. arranging piping for systems originating from adjacent prefabricated modules.

[0127] Furthermore, the shape with lateral cavities makes it possible to prepare holes close to such cavities intended to receive plant pots or rainwater containers, optimizing the use of the space inside the slab.

[0128] According to a further advantage, the cantilever is simple to manufacture and to apply to the prefabricated structure.

[0129] It is apparent that, with respect to the embodiments of the aforesaid prefabricated slab, prefabricated wall and prefabricated structure, a person skilled in the art, so as to satisfy specific requirements, could make modifications or substitutions of elements with other functionally equivalent ones.

[0130] Such variants are also contained in the scope of protection as defined by the following claims. Furthermore, each variant described as belonging to a possible embodiment may be implemented independently from the other described variants.

Claims

1. A prefabricated slab (1) for constructing a cantilevered structural element in a prefabricated structure (9), for example a balcony or a canopy, comprising a slab body (10) extending between a connection end (11) and a free end (12) in a cantilevered direction (Z); wherein said slab body (10) comprises: - an internal structural portion (101) made of reinforced concrete proximal to the connection end (11), suitable for lying inside the prefabricated structure (9); - an external structural portion (102) made of reinforced concrete proximal to the free end (12), suitable for protruding outward from a prefabricated wall (90) of the prefabricated structure (9); - an insulating portion (103) interposed between the internal structural portion (101) and the external structural portion (102), wherein said insulating portion (103) predominantly extends in a thermal break plane (T) orthogonal to the cantilevered direction (Z) and is made of an insulating material having structural mechanical properties such to contribute to the strength of the prefabricated slab (1), and wherein said insulating portion (103) is embedded in the slab body (10) when pouring the internal (101) and external (102) structural portions, so that the slab body (10) is a single prefabricated piece.

2. Prefabricated slab (1) according to claim 1, wherein the insulating portion (103) has the same cross-section, parallel to the thermal break plane (T), as the external structural portion (102).

3. Prefabricated slab (1) according to any one of the preceding claims, wherein the insulating portion (103) is a plate-like element predominantly extending in the thermal break plane (T), and is made of a wood-based structural material, preferably glued laminated lumber or laminated veneer lumber, having elastic modulus E greater than or equal to 10 kN / mm2 and / or a compressive strength perpendicular to the grain comprised between 8 MPa and 11 MPa, calculated according to standards EN 384 and EAD 130010-0304.

4. Prefabricated slab (1) according to any one of the preceding claims, wherein the slab body (10) extends in a transverse direction (Y) orthogonal to the cantilevered direction (Z) between a first upper wing (24) and a second lower wing (26) and has a longitudinal rib (2) which connects said first wing (24) and said second wing (26), predominantly extending along the cantilevered direction (Z) between the connection end (11) and the free end (12), so that two lateral cavities (41, 42) are formed between the first wing (24) and the second wing (26), i.e., the slab body (10) has a sideways H-shaped cross-section, parallel to the thermal break plane (T).

5. Prefabricated slab (1) according to claim 4, wherein the insulating portion (103) has a first indentation (240) at the first wing (24), on the side of the external portion (102), and a second indentation (260) at the second wing (26), on the side of the internal portion (101), and wherein the external portion (102) comprises a first protrusion (124) in the cantilevered direction (Z) facing the insulating portion (103) and engaging said first indentation (240), and the internal portion (101) comprises a second protrusion (126) in the cantilevered direction (Z) facing the insulating portion (103) and engaging said second indentation (260), so as to transfer the shear stresses resulting from the loads resting on said external portion (102) to the internal portion (101).

6. Prefabricated slab (1) according to any one of the preceding claims, comprising a connection element (3) protruding from the connection end (11) of the slab body (10) in the cantilevered direction (Z), suitable for generating the structural connection with an internal slab (1') in the prefabricated structure (9), placed orthogonally with respect to said prefabricated slab (1).

7. Prefabricated slab (1) according to claim 5, comprising an auxiliary insulation (105, 106) which fills the lateral cavities (41, 42) in the insulating portion (103).

8. A prefabricated structure (9) comprising a prefabricated slab (1) according to any one of the preceding claims.

9. Prefabricated structure (9) according to claim 8, comprising: - a prefabricated wall (90) predominantly extending in a longitudinal direction (X) and in a transverse direction (Y) which identify a plane orthogonal to the cantilevered direction (Z) and comprising a structural body (6) and an insulating panel (7) which covers an outer wall of said structural body (6) identifying an insulating wall plane (P); wherein the prefabricated slab (1) rests on the prefabricated wall (90) so that the insulating portion (103) is at least partially continuous with the insulating panel (7) in the transverse direction (Y), and that the external structural portion (102) protrudes in a cantilever manner with respect to the prefabricated wall (90) in the cantilevered direction (Z).

10. Prefabricated structure (9), according to claim 9, the structural body (6) of the prefabricated wall (90) is made from a single reinforced concrete pour, comprising an upper beam (62) and a lower, non-load-bearing wall element (64), wherein the beam (62) is suitable for entirely supporting the vertical loads bearing on the prefabricated wall (90) and is thicker in the cantilevered direction (Z) than the lower wall element (64).

11. Prefabricated structure (9) according to claim 10, wherein the upper beam (62) is more reinforced than the lower wall element (64), preferably the upper beam (62) is made of reinforced concrete with 150 kg / m3 of steel and the lower wall element (64) is made of reinforced concrete with 20 kg / m3 of steel.

12. Prefabricated structure (9) according to any one of claims 9 to 11, wherein the slab body (10) extends in the transverse direction (Y) between a first upper wing (24) and a second lower wing (26) and has a longitudinal rib (2) predominantly extending along the cantilevered direction (Z) between the connection end (11) and the free end (12) and connecting said first wing (24) and said second wing (26), so that two lateral cavities (41, 42) are formed between the first wing (24) and the second wing (26), i.e., the slab body (10) has a sideways H-shaped cross-section, parallel to the thermal break plane (T), and wherein the prefabricated slab (1) rests on the prefabricated wall (90) with the second wing (26) resting on the upper beam (62).

13. Prefabricated structure (9) according to any one of claims 9 to 11, wherein the slab body (10) extends in the transverse direction (Y) between a first upper wing (24) and a second lower wing (26) and has a longitudinal rib (2) predominantly extending along the cantilevered direction (Z) between the connection end (11) and the free end (12) and connecting said first wing (24) and said second wing (26), so that two lateral cavities (41, 42) are formed between the first wing (24) and the second wing (26), i.e., the slab body (10) has a sideways H-shaped cross-section, parallel to the thermal break plane (T), wherein the first wing (24) protrudes in the cantilevered direction (Z) with respect to the second wing (26), i.e., it extends with a greater length in said cantilevered direction (Z), and wherein the prefabricated slab (1) rests on the prefabricated wall (90) with the first wing (24) resting on the upper beam (62).

14. Prefabricated structure (9) according to any one of claims 8 to 11, wherein the slab body (10) extends in the transverse direction (Y) between a first upper wing (24) and a second lower wing (26) and has a longitudinal rib (2) predominantly extending along the cantilevered direction (Z) between the connection end (11) and the free end (12) and connecting said first wing (24) and said second wing (26), so that two lateral cavities (41, 42) are formed between the first wing (24) and the second wing (26), i.e., the slab body (10) has a sideways H-shaped cross-section, parallel to the thermal break plane (T), and wherein the prefabricated slab (1) comprises a connection element (3) which protrudes from the connection end (11) of the slab body (10) in the cantilevered direction (Z), said prefabricated structure (9) comprising an internal slab (1') having the same shape as the prefabricated slab (1) and being arranged perpendicularly with respect to the prefabricated slab (1), i.e. comprising a first wing (24') and a second wing (26') and a longitudinal rib (2') predominantly extending along a longitudinal direction (X) orthogonal to the cantilevered direction (Z) and connecting said first wing (24') and said second wing (26'), so that two lateral cavities (41', 42') are formed between the first wing (24') and the second wing (26'), and wherein the connection element (3) is inserted into one of said lateral cavities (41', 42') to constrain said prefabricated slab (1) structurally to said internal slab (1').

15. Prefabricated structure (9) according to any one of claims 8 to 14, wherein the slab body (10) extends in the transverse direction (Y) between a first upper wing (24) and a second lower wing (26) and has a longitudinal rib (2) predominantly extending along the cantilevered direction (Z) between the connection end (11) and the free end (12) and connecting said first wing (24) and said second wing (26), so that two lateral cavities (41, 42) are formed between the first wing (24) and the second wing (26), and wherein the prefabricated structure (9) comprises a ceiling wall (80) of a prefabricated module, arranged parallel in a lowered position with respect to the second wing (26) of the prefabricated slab (1), wherein a gap (600) is formed between said ceiling wall (80) of the prefabricated module and said second wing (26), and wherein the prefabricated structure (9) comprises systems (8) or pipes housed in said gap (600) for feeding said prefabricated module, and wherein said second wing (26) is perforated to allow the passage of pipes (800) or cables originating from said systems (8) and to facilitate the outlet thereof towards the outside through the lateral cavities (41, 42).

16. A formwork (5) for constructing a prefabricated slab (1) according to any one of claims 1 to 7, comprising: - a formwork base (50) extending in a horizontal plane and suitable for receiving a concrete pour to form the internal (101) and external (102) structural portions; - an insulating panel placed transversely to the formwork base (50) and suitable for being embedded in the concrete pour to obtain the insulating portion (103) embedded in said internal (101) and external (102) structural portions.

17. A method of manufacturing a prefabricated slab (1) according to any one of claims 1 to 7, comprising the following steps: a) providing a formwork (5) according to claim 16; b) pouring concrete to form the internal structural portion (101) and the external structural portion (102) embedding said insulating panel in the pour to obtain the insulating portion (103), forming a slab (1) in a single prefabricated piece.

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