EP0061100B1

EP0061100B1 - Prefabricated structures, method for their manufacture and their use in the building industry

Info

Publication number: EP0061100B1
Application number: EP82102021A
Authority: EP
Inventors: Silvano Casalatina; Mario Rosotto
Original assignee: Sismo International PVBA
Current assignee: Sismo International PVBA
Priority date: 1981-03-18
Filing date: 1982-03-12
Publication date: 1986-11-26
Also published as: DE3274476D1; IT1191160B; IT8167366A0; EP0061100A2; ATE23894T1; EP0061100A3

Abstract

The prefabricated structure 9a, 9b comprises a three-dimensional metallic framework 9 of welded steel wires and one or more panels 15 of insulating material. The structures with a single panel are used as partitions or floors, and those with two panels are used as forms for casting concrete 18 which fills the void between the two panels and permits this structure to be used as a supporting element in a building. The individual prefabricated structure can be combined with each other by means of a small number of linking components which allow the simple construction of external and internal walls and other constituent parts of the building under construction.

Description

This invention relates to a prefabricated structure, particularly for use in the building industry, comprising a framework of welded steel wires, supporting a panel in lightweight material.
A prefabricated structure is known from the French patent 1 374 926 which comprises a panel of lightweight material and two trellises perpendicular to the larger surfaces of the panel, wherein each trellis includes a reference longitudinal wire parallel to said larger surfaces, separating wires welded to the reference longitudinal wire and first arrest elements for engaging the panel.
The panel is disposed in front of a second panel to define a void used as form for a concrete casting. The two panels have large dimensions and are held at their given positions by two trellises located at two terminal edges of the panels. Each trellis is connected only with the two panels and is provided with a projection to be engaged with the void of an overposed structure of the same type.
The assembly of this prefabricated structures of the prior art for the construction of a building results complicated and costly. In fact a reliable alignment of each trellis with respect to the panels may be obtained only in the erecting yard of the building to be constructed. Moreover, the overposition of more panels with their trellises creates problems of alignment also for walls of . limited height. Finally, the sole terminal trellises give a limited strengthening and a series of additional transversal hooks should be engaged in the central portions of the panels.
A further disadvantage of the known structure is given by the fact that the panels do not enable a sufficient adhesion to the setting of plaster on the external surfaces of the prefabricated structure.
The technical problem of the present invention is to provide a prefabricated structure of supported or supporting type which can be implemented and put in operation easily and reliably, using unskilled personnel in the erecting yard, and which enables an easy setting of plaster in the structure.
This problem is solved by the prefabricated structure of the invention which is characterized by other trellises interposed between the said two trellises and by a plurality of transversal wires parallel to said larger surfaces and welded to the said trellises for holding the trellises at given mutual distances therebetween, wherein each trellis comprises various orders of separating wires and a first and a second external longitudinal wire welded to the various orders of separating wires to the external of the space included between the arrest elements and the reference longitudinal wires, wherein the transversal wires cause the separating wires of a same order of the various trellises to be coplanar and wherein the said panel is formed by a group of adjacent elongated sections wherein each section is inserted in the spaces defined by the first arrest elements, the reference longitudinal wires and two adjacent separating wires of said trellises.
These, and other features of the invention will be apparent from the following description, which is given by way of non-limiting example, with reference to the accompanying drawings in which:

Fig. 1 represents a schematic perspective view of the structure of the invention.
Fig. 2 is a schematic, vertical section of the structure of Fig. 1 and variants on it.
Fig. 3 is a schematic vertical section of another version of the structure in accordance with the invention.
Fig. 4 is a frontal view of a combination of two prefabricated structures in accordance with the invention, joined to each other and to parts of the building.
Fig. 5 is a view of a component linking the prefabricated structure with parts of the building.
Fig. 6 is a view of other components linking the structure with parts of the building.
Fig. 7 is a vertical section of the structure of Fig. 3 anchored to the foundation of the building.
Fig. 8 is a vertical section of a structure of Fig. 1 used in a floor of the building.
Fig. 9 is a vertical section of two prefabricated structures as in Figs. 2 and 3, used as supporting horizontal and vertical components of the building.
Fig. 10 is a perspective view of two structures as in Fig. 3, joined together and used as vertical supporting components of the building.
Fig. 11 is a horizontal section of another variant of the invented structure.
Fig. 12 is a horizontal section of a further variant of the structure of the invention.

The prefabricated structure, generically denoted by 9a, 9b (Figs. 1 and 10), comprises a three-dimensional framework 9 made of metallic welded wires, and at least one panel 15, in lightweight heat-insulating material, placed parallel to the largest surfaces 6 of the structure 9a, 9b.
The framework 9 comprises a series of trellises 8, identical to each other, essentially flat and in the form of a greatly elongated rectangle. The trellises 8 are placed one in front of the other, perpendicular to the two surfaces 6, and are kept firmly in their respective positions by means of a double series of transverse wires 7. When the structure 9a, 9b is in use, the trellises 8 will be vertical, while the transverse wires 7 are horizontal and adjacent to the largest surfaces 6 of the structure 9a, 9b. Two layers of plaster 16 cover the wires 7, forming the two largest surfaces 6 of the structure 9a, 9b.
The prefabricated structure with a single panel 15, denoted by 9a is used to form partition and floors and the prefabricated structure with two insulating panels 15, denoted by 9b (Figs. 3, and 10), is used to form supporting walls of the building under construction.
Each trellis 8 is obtained by welding together a pair of longitudinal and parallel wires 1 (vertical when the structure is in use) with separating wires 5 in such a way as to form a small staircase with steps of a constant width and pitch. Between the longitudinal wires 1 and a short way away from them, equal to the thickness of the plaster, the trellises 8 include other longitudinal wires 3 parallel to the wires 1 and also welded to the separating wires 5. The welding is carried out electrically at certain points, resting the trellises 8 on a magnetized plate provided with gauges. The length of the wires 1, 5 and 7 is equal respectively to the height, the thickness and the width of the prefabricated structure 9a, 9b. The transverse wires 7 are welded to the longitudinal wires and produce a lightweight, stable framework in which the separating wires of a similar sequence of step prove to be in the same plane as, and perpendicular to, the planes of the wires 1 and 3.
Satisfactory structures have been built in which the diameter of the wires is 2,2 mm. In a typical case, the height of the structure lies within the range 2,60-3,50 mm and its width is 1,20 m; the thickness is approximately 0,10 m for structures 9a, 9b and approximately 0,15-0,30 m for structures 9b; the trellis 8 have an interval of approximately 0,10 m and the pitch of the transverse wires 7 is approximately 0,07 m; the pitch of the separating wires 5 is approximately 0,15 m and the distance between the wires 1 and the wires 3 is approximately 0,04 m. It is obvious that these values are purely illustrative and may vary according to the particular requirements of the construction.
The panels 15 can be made of various cellular material such as polyurethane foam, polystyrene and PVC of medium density, or of fibrous materials such as fiberglass; or of lamellate materials,or of a mixture of materials. In short, in specific case the material may even be non- insulating or non-metallic.
The panels 15 are subdivided into parallelepiped lumps 2 of a definite thickness and height, respectively 0,04 and 0,15 m in the given example.
In structures 9a for partitions, the parallelepiped space in rectangular section defined by the two pairs of wires 5 and 3 of each sequence of trellises 8 is occupied by corresponding lumps of lightweight material 2 and its section is essentially equal to the available space, and its length equal to the width of the structure 9a. After the forming of the framework 9, the individual parallelepipeds 2 are inserted in the corresponding spaces between the wires 3 and 5. This is made possible by the compliance of the parallelepipeds 2 and of the wires 3 and 5. The structure is ready to put into operation, lacking only the plaster for re-covering the space between the wires 1 and 3. Wires 3 hold the lumps 2 in place between the surfaces 16 of the structure and correctly aligned with each other.
In the structure 9b (Figs. 3 and 10), the trellises 8 comprise, besides wires 1 and 3, two further longitudinal wires 4, welded to the separating wires 5 and placed between wires 3 parallel with these same wires 1 and 3, which provide stops for the two panels 15. When the framework 9 is completely assembled, the separating wires 5 of an identical sequence of steps to trellises 8, together with the two pairs of wires 3 and 4, define two parallelepiped spaces in rectangular section for the whole width of the framework itself. These spaces are occupied by lumps 2 inserted as in the framework of structure 9a. When all the spaces have been filled with the lumps 2, the structure 9b proves to be composed of a three-dimensional metallic framework with two panels in lightweight material separated by a void 17. This void may ve filled directly by a casting of concrete 18 whose form is determined by the panels 15 implemented with the lumps 2 (Fig. 9).
The concrete 18 makes it possible to use the structure 9a as a supporting structure for other parts of the building and renders simple the integration with other horizontal or vertical structures in the building. Moreover the resistance of structure 9b to the various stresses can be improved by inserting in the void 17 a framework of vertical 19 or horizontal 23 bars. The resistant concrete sections 18 and therefore the distance between the panels 15, the number and the section of the bars 19 and 23 are determined by the designer of the building with the usual rules for reinforced concrete and, as a precaution, the contribution of the framework 9 of the structure 9b is not taken into account.
The prefabricated structures 9a, 9b may be modified in the builder's yard using saw and shears to adapt it to particular requirements of the building. For example, one of the two panels 15 in structure 9b may be interrupted to allow space for a concrete pillar 32 (Fig. 11), which will be of a piece with the concrete 18 which fills the void 17.
Other structures may be altered from production on. A structure 9c (Fig. 2) consists simply of a framework of longitudinal wires 40, of short spacing wires 41 and of transverse wires 42. This structure is particularly adapted to strengthening work and as support for plaster during restoration work.
The structures with a single panel 15 may have a simplified form 9d with only three longitudinal wires for each trellis, when the plastering of one of the sides of the structure itself is of no importance. I.e., one of the two wires 3 is eliminated. The structures with a single panel may also take the form denoted by 9e, in which the lightweight material consists of large parallelepipeds 43 which give the structure an increased thickness indispensable for its use as a floor.
As another example, some 9b structures (Fig. 12) have one side modified to form the walls of a corner. In particular, a terminal trellis 44 has a single series of rectangular sections, the panels 15 have their edges bent at an angle of 45° and the edge of one panel juts beyond the other by an amount equal to the thickness of the panel 15. This variant permits the simple formation of a supporting corner wall, using two of these structures reversed. Two series of small steel rods 39 sunk in the block of concrete 18 ensure the necessary resistance at the corner structure, together with other linking components 45 of the adjoining wires 1. Some linking components of a particulartype permit an outstanding utilisation of structures 9a and 9b, both in mutual links and in links with other structures in the building.
The horizontal junction between two structures 9a and 9b is achieved with steel straps 12 inserted between the wires 1 and 3 on both sides of the structure (Fig. 4 and 10) and their extremities engage with the parts ofthetwo wires 5 which protrude from the panels 15. The straps are then covered with plaster 16. Moreover, to improve the adhesion of the plaster, the straps 12 are corrugated and have sawn edges. These straps, placed at various heights, ensure a secure linking and reduce the possibility of error in the joining together of the two structures.
The joining of the structures 9a, 9b and 9c and the horizontal structures of the building is reinforced by means of simple short shaft 46 of improved adhesion, of steel rods 28 (Fig. 6) in a U-shape, of angle iron, and of reinforcing components 30 made of welded wires (Fig. 5), these too being angled. The components 30 comprise three steel rods 21, 20 and 22 parallel to each other and placed in correspondence with the vertex and the extremities of the arms of the L-shaped section via the wires 25 bent into an L or via a pair of wires in a sinuous pattern welded respectively between the end rod 20 and the vertex rod 21, and between the rod 21 and the other rod 22.
To put the supporting walls into operation, a foundation 48 (Fig. 7) of reinforced concrete is used and care must be taken to insert the short shafts 46 in the areas where the panels 9b will be inserted and allowing the shafts 46 to protrude from the surface of the foundation. The structure 9b are then rested on the foundation in such a way that the void runs across the shafts 46 and that the sides of the various structures match. The structures are joined together with the rods 12 and reinforcing components 30 are placed on top of them, if necessary inserted between the lump 2 and the wire 1 (Fig. 9). Finally, the concrete casting is used in the void 17.
To construct a supporting floor, structures 9e are used, of half the normal width (0,60 m in the preceding example), and they are reinforced at the edges by means of an angle-iron 47 (Fig. 8), used in pairs, to form an inverted T-shaped beam which meets the adjoining edges ofthetwo structures 9e. At the edges of the structures 9e the wire 5 which protrudes below the last parallelepiped 43 is cut and the lowest edge of the same parallelepiped 43 is bevelled. Finally, one side- of the angle-iron is inserted between the parallelepiped 43 and the wire 1. More components of the same kind are rested on the supporting structures of the building and converge to form the floor of the desired width. The whole may be inserted in the concrete 18 which is retained by the two wings of the inverted T in the areas of the links between the two half-structures 9e.
To join the walls of the various levels to each other and to the horizontal floors, the procedure is as denoted by Fig. 9, inserting the rods 28 which are U-shaped across the transverse wires 5 and uniting the whole by means of a casting of concrete. Where necessary, rods 19 and 23 and the reinforcing component 30 were inserted and horizontal beams were implemented, using a lump 2 of specific thickness instead of a parallelepiped for the bearing part of the floor. The hollow part was used as a form for the beam of reinforced concrete 49 with the rods 23.
Once the structure is in use, the installation of plumbing and electrical wiring 50 (Fig. 4) is facilitated by the "holds" represented by the wires 1, and 7. The subsequent covering of the plaster 16, both for the walls and for the inner surface of the floors can be carried out by hand or with a plastering machine without the need for comparisons. The wires 1 and 7 are in fact almost in the same plane and the plaster will be perfectly flat when it barely covers the wires 7.
From this description it is clear that with a few simple components the prefabricated structure of the invention makes possible the implementation of buildings in a simple and inexpensive manner, using generic workers. The individual structures will prove light and easily transportable. In use, by contrast, the structure will prove very strong and will have excellent heat-insulation characteristics. It is also suitable for use in seismic zones.

Claims

1. A prefabricated structure (9a, -9b, 9e), in particular for building purposes, comprising a panel (15) of lightweight material and two trellises (8) perpendicular to the larger surfaces of the panel, wherein each trellis includes a reference longitudinal wire (3 right) parallel to said larger surfaces, separating wires (5) welded to the reference longitudinal wire and first arrest elements (3 left) for engaging the panel, characterized by other trellises (8) interposed between the said two trellises and by a plurality of transversal wires (7) parallel to said larger surfaces and welded. to the said trellises for holding the trellises at given mutual distances therebetween, wherein each trellis comprises various order of separating wires (5) and a first and a second external longitudinal wire (1 left and 1 right) welded to the various orders of separating wires (7) to the external of the space included between the arrest elements (3 left) and the reference longitudinal wires (3 right), wherein the transversal wires (7) cause the separating wires (5) of a same order of the various trellises to be coplanar and wherein the said panel (15) is formed by a group of adjacent elongated sections (2) wherein each section is inserted in the spaces defined by the first arrest elements (3 left), the reference longitudinal wires (3 right) and two adjacent separating wires (5) of said trellises.

2. Prefabricated structure according to claim 1, wherein each trellis (8) comprises another reference longitudinal wire (4 left) welded to the separating wires and second arrest elements (4 right) engaging a second panel (15 right) to define a form for a concrete casting (18), characterized in that the first and the second external longitudinal wires (1) are adjacent to the first and the second panel, respectively, and the second panel (15 right) is formed by a second group of elongated sections (2) inserted in the space defined by the other reference longitudinal wire (4 left), the second arrest elements (4 right) and two adjacent separating wires (5).

3. Prefabricated structure according to claim 1 or 2, characterized in that the said first arrest elements or the first and second arrest elements comprise a first arrest longitudinal wire (3 left), or a first and a second arrest longitudinal wire (3 left and 4 right), respectively, parallel to said first and second external longitudinal wire (1) and welded to said separating wires (5).

4. Prefabricated structure according to any one of the preceding claims, characterized in that said trellises (8) are substantially identical to each other, the separating wires (5) of a same order lie on planes perpendicular to the longitudinal wires (1, 3), the wires of said plurality of transversal wires are regularly spaced therebetween and are parallel to the planes of said separating wires, and said elongated sections have a parallelepipedal shape to occupy the associated spaces of the said trellises.

5. Prefabricated structure in accordance with any one of the preceding claims, characterized in that a first group of said transversal wires (7 left) is welded to the first external longitudinal wires (1 left) lying at a side of the panel or panels and a second group of said transversal wires (7 right) is welded to the second longitudinal wires (1 right) lying at another side of the panel or panels and wherein the external longitudinal wires (1) define, together with the transversal wires, two planes parallel to a larger surface (6) of the said structure.

6. Prefabricated structure according to claims 4 and 5, characterized in that a portion of said separating wires (5) projects from two adjacent elongated sections (2), and wherein the first external longitudinal wires (1 left), the transversal wires (7 left) at a side of the panel or panels and the second external longitudinal wires (1 right), the transversal wires (7 right) of the other side of the panel or panels and the portions of separating wires projecting from the two adjacent elongated sections are enabled to define a support structure for a plaster (16) covering the larger surfaces of the panel or panels.

7. Prefabricated structure in accordance with any one of the preceding claims, characterized by a strengthening component (30) including a framework with an L-shaped section formed of at least three wires (20, 21, 22) welded to distantial wires (25) and in which one side is made to form a pair with one edge of the prefabricated structure in such a way that the distantial wires may be included in the concrete casting (18) and in which the other side of the framework is made to form a pair with the larger surface of the said structure.

8. Prefabricated structure in accordance with any one of the preceding claims, characterized in that at least the elongated sections of one panel includes heat insulating material.

9. Prefabricated structure according to any one of the preceding claims, characterized in that said elongated sections (2) are inserted between said trellises after the welding of the transversal wires (7) to the said trellises (8).

10. Prefabricated structure in accordance with any one of the preceding claims, characterized by a linking component (12) including a thin plate whose extremities are bent for linking together parts of the separating wires (5) of two adjacent prefabricated structures and included between the external longitudinal wires (1) and the larger surfaces of said structure.

11. Prefabricated structure in accordance with any one of the preceding claims, characterized in that one prefabricated structure (9e) may form a floor in conjunction with another prefabricated structure (9b) using a pair of strengthening frameworks (47) with an L-section angle iron, joined in such a way that an inverted-T structure is produced and in which said strengthening frameworks support the adjoining edges of the said one and other prefabricated structures (9e and 9b) and in which a casting of concrete (18) includes said prefabricated structures and said strengthening frameworks (47).

12. Prefabricated structure in accordance with any one of the preceding claims, characterized in that the spaces for said sections as defined by two adjacent separating wires in each trellis (8) have a constant pitch for accommodating elongated sec. tions (2) of identical dimensions and wherein the pitch of the transversal wires (7) is the half of the pitch of said spaces.

13. Method for the construction of supporting structures of buildings, characterized by the following steps:

implementing prefabricated structures (9b) including a metallic framework (9) and two panels (15 left and 15 right) held by the trellises (8) and defining a form between the two panels, according to claim 2;

laying a foundation of reinforced concrete (48) letting rods of steel (46) project from the foundation;

resting a number of the said prefabricated structures (9b) on the foundations in such a way that said form (17) passes across the steel rods;

joining the structural elements together by means of metallic components (12) matched to the trellises of two adjacent structures; and

inserting a concrete casting (18) in the form between the panels of said prefabricated structures to join the supporting structure to the foundation.

14. Method for obtaining a prefabricated structure according to claim 3, characterized by the following steps:

welding together a number of metallic wires including external longitudinal wires (1 left and 1 right), reference longitudinal wires (3 right or 3 right and 4 left), arrest longitudinal wires (3 left or 3 left and 4 right), with various separating wires (5) in such a way as to form a substantially planar trellis (8) having various orders of rectangular sections of appropriate dimensions defined by said separating wires and by the reference longitudinal wires and the arrest longitudinal wires;

joining together said trellises (8) at predetermined distance therebetween welding to them a number of transversal wires (7) substantially perpendicular to said trellises for aligning the wires of each order of said sections along corresponding planes; and

inserting, into the said group of rectangular sections a corresponding group of elongated sections of insulating material (2) parallel to said transversal wires (7) in such a way as to provide one or two panels (15) forming a single or double barrier against the passage of heat.

15. Method for the construction of floors of buildings characterized by the following steps:

implementing at least two prefabricated structures (9e) according to claim 1;

implementing a strengthening framework (47) in the form of an inverted T;

resting two edges of the two structures on the wings of the strengthening framework;

resting more strengthening framework and prefabricated structures (9e) on the supporting structures of the building until the desired floor has been constructed;

inserting the floor in a concrete (18) which includes the T-shaped framework (47) and the edges of the prefabricated structures; and

deposing plaster (16) on the interior surface of the floor until the space between the external longitudinal wires (1) and the elongated sections (12) is completely covered.