EP0464008B1 - Foamed plastic modular element faced with a mortar layer connectable to adjacent units, process for forming and method of erection - Google Patents

Abstract

A composite modular element for constructions generally comprising a body made from a foamed synthetic material is provided with preformed covering panels (9, 10) on the two opposite external faces of the modular element. The covering panels may be formed on site by pouring and levelling a cement mortar preferably reinforced with the aid of fibres onto a "shuttering" composed of a peripheral edge (6) formed on the face of the foamed-resin body and on which there is also a peripheral groove on the inside of this edge and a series of transverse grooves in order to give rise to a like number of ribs (11) of the formed cement-mortar panel, which assumes intrinsic load- bearing properties. The modular elements may be laid without clamping yokes, by virtue of their weight and their load-bearing capacity, and the panels of a facade are joined together permanently by "consuming" with the aid of a heat torch the foamed resin of the edges along the junction lines between the laid elements, and by filling in with mortar the breaks thus created in the mortar and levelling the surface of the external facade. <IMAGE>

Description

The present invention relates to techniques for constructing perimeter walls and partitions of buildings using modular elements of expanded synthetic material predisposed to receiving an external coating layer. This invention relates in particular to a modular element of expanded synthetic material having a cement mortar coating preformed on the two external faces, the method for forming this coating and the method of erecting a wall using these panels.

The use of modular elements in expanded synthetic material, in particular in expanded polystyrene, for the production of perimeter walls and internal partitions, crossed or not by reinforced concrete pillars thrown into cavities present for this purpose in the body expanded polystyrene, as well as floors, blankets, etc .; has long since become widespread practice in the building sector by virtue of the many advantages that these construction techniques offer compared to more traditional techniques under many conditions of use in the building sector, both civil and industrial.

There are two categories of problems related to the use of these panels or elements in expanded resin to build walls or internal decking: a first problem relates to the erection procedures and in particular to the need to adequately support the structure laid to be able to proceed with the reinforcement and the pouring of the internal concrete pillars without risk of displacement of the laid panels which may be subject to high stresses or shocks. Another problem relates to the predisposition of the two external faces of the panels to receive a suitable coating layer which generally consists of a layer of plaster or mortar.

A common solution to the first problem was that of providing stirrups or external reinforcements of the wall or walls of panels placed in a position to give the assembly sufficient stability against stresses, which are removed after the casting and the solidification of the load-bearing and connecting elements (pillars often cast at the same time as the beams and cords of the floor located above).

With regard to the second problem, that of the external coating of expanded resin panels, several techniques have been developed, all widely documented in the specific literature and well known to technicians in the sector. According to one of these techniques, the expanded polystyrene panels are provided with metal grids or expanded sheets on the two external faces, linked together by metal tie rods which pass through the thickness of the panel. The metal grid applied to the external face of the panels provides a surface perfectly suitable for the application of a layer of mortar or plaster, according to traditional techniques. Moreover, the presence of the metal tie rods for supporting and supporting the grids creates numerous thermal bridges between the opposite faces of the structure which partially cancel out the presence of the expanded polystyrene body with high thermal insulation. In order to avoid the need to extend the covering layer on the structure already laid, according to traditional techniques, panels were produced provided, on the opposite external faces, with a precoating obtained by production techniques in "sandwich" which consists in gluing preformed external covering plates on the faces of the central body of expanded polystyrene using glues or adhesives. According to another known technique, it is possible to produce panels on the external surfaces of which bricks are incorporated directly during the molding phase of the central body made of expanded polystyrene by exploiting hollows in the internal surface of the bricks to ensure the connection between the three elements of the sandwich structure. The latter solution however required the execution of a finishing layer of the structure assembled according to traditional techniques. The manufacture of these sandwich products necessarily requires the production of relatively complex and costly production lines for which it is necessary to carry out complicated assembly operations.

Document US-A-4 614 071, described a composite building block in which two preformed concrete plates, provided with ribs and coordinated assembly grooves, are mechanically connected together and the separation space is blocked with a expanded resin to form a single easily stackable parallelepiped block. The composite block is produced in a mold, by placing the preformed plates in the mold, introducing into the mold a load of expandable resin and giving rise to the expansion of the resin between the two plates, provided with anchoring recesses for expanded resin.

• autoportance et stabilité des panneaux posés de façon à ne pas devoir recourir à des échaffaudages et à des étriers avant que les piliers et les autres éléments de liaison de la structure ne soient formés;
• pré-revêtement des faces externes des panneaux de façon à ce qu'il ne soit pas nécessaire d'étendre une couche de revêtement sur les façades de la structure montée selon les techniques communes;
• possibilité de réaliser le revêtement préformé sur les faces externes du produit sans devoir faire recours à des techniques de fabrication en "sandwich" et sans qu'il soit nécessaire d'utiliser des colles ou adhésifs structuraux.

A common aspect of all these known type composite panels is the inability to have three basic characteristics at the same time:

• self-supporting and stable panels installed so that scaffolding and stirrups are not required before the pillars and other structural connecting elements are formed;
• pre-coating of the external faces of the panels so that it is not necessary to extend a coating layer on the facades of the structure assembled using common techniques;
• possibility of carrying out the preformed coating on the external faces of the product without having to resort to "sandwich" manufacturing techniques and without the need to use glues or structural adhesives.

On the contrary, these objectives are all fully obtained by the present invention as defined in the appended claims.

Basically, according to a first embodiment, the modular element of the invention comprises a self-supporting substantially parallelepiped body, of a length, height and width correctly standardized, of expanded synthetic material which is provided with a cement mortar coating. preferably reinforced by the addition of glass fibers and / or other mineral fibers or natural fibers or synthetic fibers or artificial fibers able to give the aggregate a higher mechanical resistance, obtained by sinking and shaving the pasty mixture in a "formwork" constituted by a continuous frame edge made of polystyrene capacity formed over the entire perimeter of each of the two external faces of the body of expanded synthetic material. The mortar to form the covering panel can be poured, leveled and allowed to solidify first on one side and then repeat the operation on the other side of the element. The perimeter bead whose width can be between 5 and 20 millimeters in practice constitutes a formwork in which it is easy to pour and shave the soft paste of the cement mortar loaded with fibers, by simply placing the elements in a horizontal position. The coating layer thus formed will have a thickness equal to the elevation height of the edge perimeter with respect to the lowered level of the face of the polystyrene body, which is preformed in special molds, according to the usual techniques for molding this material.

Cavities are predisposed on the face to be coated with the polystyrene body, inside the perimeter edge. It is in these cavities that the filling mortar is poured, giving rise to appendages or ribs of the mortar coating panel which have the double function of mechanically reinforcing the structure and of achieving a permanent connection between the mortar coating panel and the body of expanded resin, even by making cavities with a certain undercut functionally oriented for this purpose. A first appendage or rib of the mortar layer thus preformed on the face of an element develops over the entire perimeter of the coating layer without a solution of continuity, extending over a certain depth inside the resin body. expanded.

The two longitudinal sides of this first appendage or perimeter rib are connected by a series of pairs of parallel ribs, located at a distance from one another equal to twice the thickness of the perimeter edge containing expanded resin and oriented perpendicular to the length of the work and uniformly distributed along the length of the work, at intervals having a length equal to a fraction of the length, preferably equal to the standardized height and thickness of the work and equal to each other. In this way, it is possible to cut the work along a section plane between one of these pairs of parallel ribs to achieve any embedding between laid panels orthogonally to each other at the edges of the structure being assembled.

Normally, the thickness of the mortar covering panel formed on the opposite external faces of the body of expanded resin can be between 5 and 50 millimeters and it is this same thickness that the anchoring appendages have on average. extend inside the body of expanded resin to a depth which can vary from one to three times the average thickness of these appendages. If they are adequately sized, these covering structures thus preformed on the two external faces of each element are able to give the work an intrinsic mechanical robustness and a "specific weight" capable of imparting to a wall or to a wall constructed with these elements of bearing capacities which can be compared to that of structures made of bricks according to traditional techniques, even without the formation of internal pillars. This is obtained by "uniting" between them the various failure of the preformed coating during the finishing phase of the wall laid, according to the method of the invention.

The method of the invention consists in approaching and laying in an adjacent position the modular elements which, by their characteristics of robustness and weight conferred by the two opposite panels of coating mortar, do not require the use of temporary support structures and stabilization and, after completing the erection by consuming the expanded resin of the frame edges along all the lines of separation between the adjacent mortar cladding panels using a torch or the like localized application of heat over a sufficient depth. These cavities (leaks) thus formed on the facade are then filled with cement mortar, to which we will preferably have added reinforcing fibers, glass or another suitable material, of the same type as that which was used to form the structures or cladding panels of the external surface of the modular elements so that all the preformed cladding panels are securely joined together, forming a continuous facade which assumes intrinsic bearing characteristics due to the nature of the mortar used, to the thickness of the preformed covering layer and the presence of the anchoring ribs in the central body of expanded resin which are functionally oriented in order to provide a particularly developed bearing section, and to the continuity acquired by this external covering structure when filling and shaving specially formed "leaks" between the covering panels preformed on the face of the modular elements.

• la Fig. 1 est une vue schématique en perspective d'un élément modulaire en résine expansée prédisposé pour recevoir une couche de mortier de ciment de revêtement externe;
• la Fig. 2 est une vue en coupe de l'élément de la Fig. 1 après la formation des couches de revêtement externe sur les deux faces;
• la Fig. 3 est une vue en coupe orthogonale par rapport à la vue de la Fig. 2 du même élément;
• la Fig. 4 est un détail agrandi de la structure de revêtement préformée;
• la Fig. 5 est une vue en coupe transversale en élévation d'un élément modulaire selon une forme alternative de réalisation de l'invention dans lequel ont été incorporés des éléments métalliques de liaison mécanique entre les deux structures de revêtement préformées opposées;
• la Fig. 6 est une vue latérale de l'élément montré à la Fig. 5;
• la Fig. 7 est une vue en perspective d'un mur réalisé avec les éléments assemblables de l'invention;

   la série des Fig. 8-10 montre de façon séquentielle les opérations du procédé de l'invention pour unir structurellement entre elles de façon permanente les structures de revêtement préformées sur les faces de chaque élément.The various aspects and advantages of the invention will be more evident in the description in detail below of some preferred embodiments and with reference to the appended drawings among which:

• Fig. 1 is a schematic perspective view of a modular element in expanded resin predisposed to receive a layer of cement mortar for external coating;
• Fig. 2 is a sectional view of the element of FIG. 1 after the formation of the outer coating layers on both sides;
• Fig. 3 is a view in section orthogonal to the view in FIG. 2 of the same element;
• Fig. 4 is an enlarged detail of the structure preformed coating;
• Fig. 5 is a cross-sectional elevation view of a modular element according to an alternative embodiment of the invention in which metal elements of mechanical connection have been incorporated between the two opposite preformed coating structures;
• Fig. 6 is a side view of the element shown in FIG. 5;
• Fig. 7 is a perspective view of a wall produced with the assemblable elements of the invention;

the series of Figs. 8-10 shows sequentially the operations of the process of the invention for structurally uniting the coating structures preformed on the faces of each element permanently.

For convenience of reading, in all the figures, the same parts which are substantially similar to each other bear the same number when it is not necessary to identify them in another way.

Fig. 1 schematically shows a preformed central body 1 of expanded resin of a modular element of the invention. This body 1 of expanded resin can be produced by applying any technique for forming these products. The material preferably used is expanded polystyrene and a particularly suitable production technique is the profiling of a mold of the module obtained by filling the internal volume of the mold using small balls of pre-expanded polystyrene having a density between 15 and 60 kg / m³ and by introducing steam into the mold to completely expand the resin which fills all the interstices of the mold. After cooling, a vacuum can be created to stabilize the work which is finally extracted from the mold. The module thus formed in standard length has a height and a thickness normally equal to each other and is provided with a series of holes 2 and 3 which cross the body in the direction of the height of the latter at regular intervals along the length of the module so that they are modularly superimposable on each other during the erection of a wall so that they can be used to make the reinforcement, the internal pillars and the vertical pipes. As can be seen in the cross section in elevation of FIG. 3, the opposite upper and lower faces of the expanded resin module are respectively provided with raised parts 4 and depressions 5, at least around the perimeter of the holes, to make the labyrinths during the laying of a module on the other necessary for the capacity of the castings and for constituting embedding elements which ensure self-centering and the connection of the modules to each other during installation.

According to the present invention, at least one, but preferably the two outer faces of each preformed expanded resin module 1 are provided with a continuous frame edge 6 over the entire perimeter of the face. This frame edge has a certain height which is normally between 5 and 50 millimeters but which can also be greater and starts from the lowered level of the face of the preformed body of expanded resin 1. The thickness of this perimeter edge 6 is preferably between 5 and 20 millimeters. At the base of the internal side of this perimeter edge 6 is also a continuous cavity having a width substantially identical to the height of the edge 6 and a depth which can be equal to two or more times the width. This perimeter cavity is also devoid of discontinuity over the entire perimeter of the lowered face delimited by the edge 6. At modular regular intervals between them along the length of the body 1 are also pairs of furrows 8. parallel to each other which converge at their end in the perimeter cavity or furrow 7. The grooves 8 of these pairs also have a width and a depth equal to the width and the depth of the groove or perimeter cavity 7. The same configuration of edge, perimeter cavity and pairs of grooves 8 is exactly repeated on the opposite external face of the module 1 (which in the perspective view of FIG. 1 represents the bearing face of the part).

As we can easily observe, the frame edge 6 constitutes a real "formwork" which makes it possible to pour on the lowered face and provided with grooves of the preformed body of expanded resin 1 a soft paste of cement mortar formed by sand, cement, plasticizing additives and preferably containing a certain quantity of reinforcing fibers of glass wool or other inert fibrous material. The dough also fills the cavities 7 and 8 and can easily be shaved so as to give a perfectly flat and leveled surface, being at the same level as the upper edge of the frame edge 6 of expanded resin.

After solidification of the cast material, this same process can be repeated on the opposite face of the expanded resin body 1 so as to place cement mortar on the two external faces of the preformed coating module. Alternatively, if special equipment is available, it is not necessary to wait for the solidification of the material cast on one side before applying the coating on the opposite side. One can for example use a counter-mold to cover the casting carried out on a first side so that the element can be turned over and then pour the mortar on the opposite side. In both cases, the shaping of cladding panels on the faces of the modular elements is an operation which can advantageously also take place at the building construction site. In this way, the transport costs can be significantly reduced compared to the case of transporting elements already pre-coated.

The two faces of the composite modular element which are obtained are shown in sectional views, orthogonal to one another, in FIGS. 2 and 3. The central body of expanded resin 1 is associated with two structures or external covering panels preformed on the two opposite faces of the modular element and respectively indicated by n. 9 and 10. These external coating structures are contained inside the frame edge 6 of expanded resin which served as formwork for casting and for shaving the coating material. Being perfectly possible to form preformed coating structures on the external faces of modular elements even of considerable thickness and using mortar formulations having very good mechanical strength characteristics, the manufacturing process being free from limitations and difficulties specific to the sandwich work, the preformed structures of external coating can themselves be load-bearing elements. To this bearing capacity of the covering element essentially contribute the vertical ribs 11 represented by the mortar appendages which form inside the grooves 8 and the perimeter groove 7 of the face of the expanded resin body 1. These same appendices 11 which extend to the interior of the expanded resin body 1 ensures the creation of an adequate retaining junction between the expanded resin body 1 and the respective body of coating cement mortar 9 and 10. This coupling between the parts that make up the element modular composite of the invention can be strongly guaranteed by forming the cavities which will give rise to the mortar ribs with light recesses functionally oriented so as to increase the mutual retention between the two parts. This is exaggeratedly demonstrated in the partial sectional view of FIG. 4. This enlarged partial view also illustrates by means of lines and lines the way in which a modular modular element of the invention can be cut to adapt it to the laying requirements, while maintaining the configuration of the element itself functionally intact. cutting level. The cut is made by milling using an abrasive disc the portion F of the cement mortar coating 9 (or 10) over a length of about 20 millimeters along the midline between the two parallel ribs 11 which generally have a gap of 30 to 50 millimeters, then repeating the same operation on the opposite face of the modular element and cutting with a hot wire instrument the expanded polystyrene body along the plane of the line indicated by the lines T. As it is easy to observe, the two cutting faces retain a configuration similar to one of the two ends of the element. In this way, it is possible to shorten a modular element, at least for whole multiples of a certain modular dimension which, as described before, is normally equal to the height and width of the element, to satisfy the major part of necessities during installation.

The invention can also be implemented in alternative forms to that described above, according to specific requirements for use. This is the case, for example, of conditions of use for which it is necessary to make a jetty of a continuous wall of concrete in order to meet special standards. Figs. 5 and 6 illustrate a specific alternative embodiment of the invention adapted to the latter case, in which the modular element is provided with metal tie rods connecting two preformed covering panels on the opposite faces of the element. As can be seen in the sectional view of FIG. 5 and in the side view of FIG. 6, the modular element is composed of two separate bodies or plates 1 and 1 'of expanded resin on the respective external faces which make up the perimeter edge 6, 6', the perimeter cavity 7, 7 ', and the pairs of transverse grooves 8 (visible in the side view of Fig. 6), as described above. On the external faces of the two sheets of expanded resin 1 this 1 ′, niches 13 are also formed during the phase of molding the sheets. The bottom of these niches is provided with a small loop 14 which passes through the thickness of the plate. Through these loops pass the ends of rings of galvanized steel wire 12 so that the diametrically opposite sides or ends of the rings of steel wire emerge from the bottom of the cavities 13 distributed on the face of each of the plates expanded resin preforms 1 and 1 '. The two sheets of expanded resin 1 and 1 ′ are suitably supported one parallel to the other so as to ensure a certain separation distance between the faces respective internal during the phases of formation of the covering panels according to the invention, and the cement mortar is then poured and shaved as already described above, to produce the two preformed covering panels on the opposite faces of the composite modular element. As partially shown in Fig. 5, the cement mortar panel thus formed encompasses the ends of the metal rings 12 which emerge through the loops 14 from the bottom of the niches 13 of the external plane of each expanded resin plate so that the assembly is connected by means of the set of metal rings 12 which connect the two opposite panels of mortar covering formed on the external face of the two sheets of expanded resin. The composite elements thus produced can be installed without the need for recourse to support brackets, in a manner completely analogous to the modular elements already described above. To complete the structure, filling concrete can be poured into the continuous chamber delimited by the opposite internal faces of the expanded resin plates 1 and 1 ′ by producing the continuous concrete structure. In this case also, the cladding panels preformed on both sides of the modular elements can be united according to the method of the invention to form continuous facades ready to receive the possible finishing treatment.

Fig. 7 schematically illustrates a wall produced by fitting modular elements of the invention as described above, by cutting the custom elements where necessary to form the edges of the structure under construction. The intrinsic robustness of the modular elements and their "weight" allow build a wall without using temporary stability brackets, which saves a lot of labor.

The series of Figs. 8, 9 and 10 'schematically illustrates the method of the invention for permanently connecting the structures together or the preformed cladding panels of the various modular elements which make up a wall or a partition. These figures are partial sections which represent any joint between two adjacent modular elements placed. As can be seen in FIG. 8, along a junction line between two adjacent elements, the two frame edges 6 of the respective elements are on the face. Until this time of installation, they separate between them the various cement mortar panels 9 of preformed coating on the faces of the modular elements. Using a torch or similar localized heat distribution device, the fitter "consumes" the expanded resin from the edges 6 until the front of the resin stops for a certain distance along the sides thus uncovered perimeter ribs 11 of the adjacent coverings. In this cavity 15 thus produced which exposes the opposite surfaces of the perimeter appendages 11 of two adjacent coatings of cement mortar 9 preformed on the faces of the modular elements, is applied using an appropriate heat distribution apparatus of the mortar. plastic cement in sufficient quantity to completely fill the cavity. The filling of the "leaks" thus produced between the adjacent coating elements is naturally accompanied by a shaving operation. With the solidification of the mortar, the whole "facade" acquires continuity perfect structural which makes it fully capable of supporting loads commensurate with the dimensioning of preformed mortar panels. In addition, it results perfectly finished and suitable for receiving any finishing treatment or coating.

The descriptions and illustrations of the figures show that, unlike the prior art, the present invention provides an effective and original answer to the problems indicated at the beginning of the description.

Naturally, for particular applications, it will be possible to preform the panels of cement mortar coating with high mechanical strength on only one of the opposite faces of the modular elements while it is possible to preform on the other side another coating panel having characteristics different from the first and suitable, such as for example a plasterboard. In this case, the mechanical robustness must be guaranteed by the dimensions and characteristics of the external panels while the various preformed panels with internal coating will provide an easy-to-finish surface, according to the method described above.

Claims (10)

1. A composite modular element comprising at least a substantially parallelepiped body (1) of a standardized lenght of an expanded synthetic material for erecting walls, the element having an external panel (9, 10) of mortar of cement preformed on at least one of the opposite external faces of the composite modular element, characterized by the fact that
      said external panel of mortar of cement (9, 10) is contained within a continuous framing ridge (6) of said expanded synthetic material formed along the entire perimeter of said external face;
      said external panel (9, 10) of mortar of cement has a plurality of protrursions (11) for anchoring itself to said body of expanded synthetic material, uniformly distributed along said standardized lenght of the element at intervals corresponding to a given fraction of said standardized lenght;
      the expanded synthetic material of said framing ridge (6) of the external faces of the modular element being consumable by localized application of heat for a depth sufficient to create a cavity (15) along a junction line between any two modular elements, which cavity (15) may be filled with a mortar of cement and trowelled to join permanently said preformed exterior panels (9, 10) to each other to constitute a continuous facing of mortar of cement.
2. A composite modular element according to claim 1, wherein said anchoring protrusions (11) comprise a continuous perimetral rib of said mortar of cement, cast in a perimetral groove (7), which substantially extends perpendicularly for a certain depth within said body of expanded synthetic material and a plurality of double ribs (11) of mortar of cement, parallel to each other and extending along a direction perpendicular to the lenght of the element, cast into a pair of parallel grooves (8), distributed at uniform intervals of lenght corresponding to said fraction of said standardized lenght, which double ribs (11) extend for said depth within the body of expanded synthetic material.
3. A composite modular element according to claim 1, wherein said body (1) of expanded synthetic material is provided with openings (2, 3) through the height of the element, capable of receiving a reinforcing lattice and a subsequent concrete pouring for realizing pillars within the wall.
4. A modular element according to claim 1, wherein said expanded synthetic material that is consumable by the application of heat is polystyrene.
5. A composite modular element according to claim 1, wherein said external panels (9) of mortar of cement are precast on both opposite external faces of the composite element and are mechanically connected to each other by a plurality of metal rings (12), two diametrically opposite sides or arcs of circumference of which are buried in the mortar of cement of the respective panels (9) formed over the two opposite external faces of the composite modular element.
6. A composite modular element according to claim 1, wherein said facing panel (9) of mortar of cement precast on at least an external face of the element has a cross section of a size sufficient to ensure a load bearing capacity of said wall that comprises said continuous facing of mortar of cement constituted by said preformed external panels joined together with trowelled mortar of cement along junction lines.
7. A composite modular element according to claim 1, wherein said mortar of cement is strenghtened by addition to a castable mortar mixture of reinforcing fibers belonging to the group composed of glass fibers, mineral fibers, natural fibers, artificial and synthetic fibers.
8. A modular element according to claim 1, wherein a first external face of the element is provided with a precast facing panel (9) of mortar of cement and the other face of the modular element is provided with a precast facing panel (10) of a gypsum mortar.
9. A process for erecting a wall having continuous facings of a certain type of mortar capable of receiving a coating or finishing treatment, by employing modular elements (1) of an expanded synthetic material that can be laid one next to the other to form said wall, characterized by comprising
      setting said modular elements (1) of expanded synthetic material, each element having a panel (9) of said mortar, precast over opposite faces of the element and contained within a continuous framing ridge (6) of said expanded synthetic material (1), present along the entire perimeter of each of said opposite external faces;
      locally heating along a junction line between adjacent sides of said modular elements set one next to the other to consume the expanded synthetic material of said continuous framing ridges for a depth sufficient to create a cavity (15) along said junction line between adjacent modular elements;
      filling said cavity (15) with a mortar similar in composition to the mortar used for casting said panels and trowelling the mortar for permanently joining to each other said precast panels (9) thus forming said continuous mortar facings.
10. The process according to claim 7, wherein said expanded synthetic material consumable by locally applying heat is polystyrene.

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