ES2930055T3 - Weight reduction element for the construction industry - Google Patents

Abstract

A weight reduction element (1) for the construction industry, made up of at least one disposable formwork (2), substantially in the shape of a truncated pyramid, which is hollow and has a closed upper surface (4) and an opening bottom (6a). Said element has, at least near the corners (7) that are adjacent to the lower opening (6a) or near the corners (107) of the upper surface (4), hooking means (10, 110) for temporarily stable , and substantially rotatable, for interconnection with gripping means (11) associated with the free upper end (12) of a foot (8), of a chosen height. The weight reduction element (1) comprises the foot (8) having a lower end (23) that is offset with respect to the gripping means (11) and the temporary hooking means (10, 110). (Automatic translation with Google Translate, without legal value)

Description

DESCRIPTION

Weight reduction element for the construction industry

The present application refers to a weight reduction element for the construction industry, such as a disposable formwork, made of plastic material, optionally recycled, particularly adapted for its use in the creation of low weight roofs or for concrete beds. low weight foundation.

Currently, it is known to use disposable formwork made from plastic material to create low-weight roof slabs and reinforced concrete beds, the purpose of which is to provide a low-weight roof or high-thickness foundation beds with considerable savings. of concrete or provide long-span and/or far-reaching roof slabs.

For example, a product marketed under the registered trademark U-BOOT is known, which has been the subject of the filing of Italian patent no. 2005 and which has the title "disposable formwork for the construction of roof slabs, for use in the construction industry".

The aim of this prior art is a disposable formwork, preferably made of recycled plastic material, for the in- situ manufacture of roof slabs, for use in building construction, consisting of reinforced concrete plates, simple or reinforcing bars, and which constitutes the support structure of various construction elements such as roofs, bridges, foundations and the like.

Said known technique claims a disposable formwork made of plastic material for the in situ manufacture of ceiling slabs for use in building construction, which is constituted by a single hollow body in which the cavity is open downwards and which is provided with feet on its lower edge, the hollow body being shaped like a truncated pyramid with the vertex pointing upwards, and in which the lateral surfaces present emptied pilasters and the upper surface is divided into contoured sectors with a plurality of raised parts.

Said solution presents fixed feet of predetermined height.

The product sold by the company Ferracin S.r.l. with the registered trademark “GIU'H” or “TOTI” which is constituted by a disposable formwork, open in one region downwards, made of polypropylene and used as a modular element to make foundation beds and one-way or two-way reinforced concrete roofs.

In such a product, at the corners adjacent to the lower opening and disposed outside the inclined side walls thereof, ordinary through holes are provided into which conical hollow feet with a circular base are forcefully inserted. The feet have, at their circular end, longitudinal deformable seats for the forced coincidence of the foot in the holes.

Again, in this case, the feet have a predetermined height, and the formworks are shipped with the feet set in the factory, and in situ they adopt a single fixed position.

In both indicated known solutions, there is a problem to achieve the desired weight reduction: in fact, the height of the weight reduction element and the height of the foot determine a combination of two variables which, during production, results in a high number of hours worked, thus increasing the total cost of the invention.

Another drawback is that, when a formwork is made, unforeseen circumstances may arise on the site that require the formwork to be replaced, necessitating the use of higher or lower feet, with the consequent need to remove the already produced formwork and replace it quickly. , and this drawback is exacerbated if the project is in a foreign country with possible expensive local shutdowns.

Another drawback, and definitely the most serious of all, consists in the fact that, in the erection of the works described above, there may be points of interference between the feet and the reinforcing frames arranged below the weight reduction element, that is, arranged on the provisional slab roof made up of wooden planks or metal panels, even when they are slightly spaced from it by means of the interposition of separators.

It should be noted that the concrete has to completely envelop/embed/cover the reinforcing bars for structural reasons, for preservation reasons (exposed or poorly coated iron will rust, causing swells that cause chipboard parts to separate), and for the Fire resistance.

The "minimum cover" is an ever-present aspect, and is strictly controlled by all technical regulations on construction projects.

“Exposed” (ie visible) iron frames that are not sufficiently “embedded” and therefore protected by the concrete will compromise the performance of the structure.

This applicant has filed the Italian application TV2012A0000095 that claims a weight reduction element for the construction industry that is constituted by a first disposable formwork, substantially shaped as a truncated pyramid that presents in a region that curves inward with respect to the corners of the smaller surface, feet, fixed and projecting, which are provided with one or more first holes or openings and/or, in said smaller surface, one or more second holes or openings and/or, in at least one of the lateral surfaces adjacent to said smaller surface, of one or more third holes, said feet of said first disposable formwork and said smaller surface being fully or partially embedded during the provision of a precast roofing slab.

Such a solution is predominantly used in the on- site provision of lightweight bi-directional plate slab roofs (also known as hollow body or hollow cell plate roofs or by other names) or lightweight foundation beds.

This solution also presents the drawbacks previously described: the height of the weight reduction element and the height of the foot determine a combination of two variables that, during production, results in a high number of hours worked, thus increasing the total cost of production. the invention.

There is still the inconvenience due to possible unforeseen circumstances that arise in the work that require the formwork to be replaced, necessitating the use of higher or lower feet, with the consequent need to eliminate the already produced formwork and replace it quickly, and this inconvenience is exacerbated if the project is in a foreign country, with possible expensive local shutdowns.

It has also been found that there may be points of interference between the free ends of the feet or the lower part thereof and the reinforcing frames arranged below the weight reduction element, that is, arranged on the provisional slab cover made up of wooden planks or metal panels.

Frequently, the need to use different feet arises from the difficult or incorrect evaluation of the loads (or thicknesses) that are created by virtue of the overlapping parts of the "reinforcing meshes".

This occurs partly because the contracting company frequently makes changes or substitutions to the specified bar types at the design stage, which leads to possible problems in observing the “minimum bar cover thickness”.

In fact, the lower reinforcement frames, which are present in massive form, are usually constituted by electro-welded mesh with square bars (or, rarely, by loose bars or even by a combination of loose bars and rods); The presence of said electro-welded mesh frequently leads to "interference" between the feet of the weight reduction element and the iron bars of the reinforcing mesh.

It should be noted that the weight reduction element must maintain a pre-established position according to the design specifications, and the presence of the reinforcing mesh.

As a consequence of this, the formwork ends up supporting itself unevenly (it rises with respect to the intended rest surface) or moves laterally, thus losing the correct “design” position and, therefore, altering (with an increase or a reduction) the thickness of the beam (rib) that is created between one element of weight reduction and the next.

In other cases, the foot may press down on the mesh, risking the specified minimum bar cover not being met, or may even create a point of contact with the reinforcing mesh, thus preventing full “embedding” and suitable for the same in the concrete.

European patent EP2530220A1 is also known, which discloses a formwork 1 substantially shaped like a truncated pyramid, provided with legs 4, on its lower surface, which are adapted to be coupled to the formwork 1 by means of a spacer system 18 that entails that the ends The free legs 42 of the legs 4, which have a tubular-shaped structure, are pressed into respective uprights 21 that protrude outward from the bottom 3 of the formwork 1 and which also have a tubular-shaped structure with a slightly smaller diameter than the of the free end 42 of the feet 8 in order to allow the coupling thereof.

In order to achieve the coupling between the leg 4 and the formwork 1, each free end 42 of the leg 4 is thus forced by interference fit into the respective upright 21 in the bottom 3 of the formwork 1; once the leg 4 is connected to the upright 21, the orientation of the leg 4 which can be engaged only once cannot thus be changed and/or deviated.

Therefore, it has been found in this case also that during the use of the formwork 1 in the production of roofing, interference points can be created between the feet 4 and the reinforcing frames arranged below the weight reduction element, in the roof of provisional slab, leading to the many and varied drawbacks explained above.

Also known is the Italian application PN99U000040 entitled "improved formwork for the construction of floors, roofs and the like" which was extended as European patent application EP1092816A2.

Said document refers to a formwork 10 defined by a dome 11 from which four legs 12 extend laterally and downwards; at the lower end of each leg 12, there is a fixed fork 16, which protrudes and is open downwards, which follows the profile of the leg 12 and fits into the upper rim of a tubular element 17 (or foot), which is arranged vertical position.

Therefore, the recessed connection of the fork 16 of the formwork 10 with the tubular elements 17 also does not allow the unique orientation of the tubular elements 17 to be changed and/or deviated.

In this case also, during the use of the formwork 10, interference points can thus be created between the tubular elements 17 and the reinforcing frames arranged below the weight reduction element, which leads to the many and varied drawbacks explained above.

Therefore, the main purpose of the present invention is to solve the aforementioned technical problems, eliminating the drawbacks in the cited known art and thus providing an invention that makes it possible to obtain, using disposable formwork made of plastic material, a low-weight roof or beds. low-weight, high-thickness foundation with considerable savings in concrete, at the same time being able to use said formwork quickly and at low cost based on an intentional and contingent height of the feet, even when this is different from the height of the design.

Within the above purpose, another important object of the invention is to provide an invention that can be used while avoiding interference points between the free ends of the feet or parts of the feet and the reinforcing frames arranged below the weight reduction element. .

Another objective is to obtain a formwork that always rests optimally with respect to the intended rest surface and observing the exact location of the design thereof.

Another object is to provide an invention that is structurally simple and convenient to use and that can be provided with the usual conventional systems.

This purpose and these and other objectives that will be more clearly revealed in this report below are achieved by a weight reduction element 1 for the construction industry, which presents the characteristics of claim 1.

Other features and advantages of the invention will become clearer from the detailed description of a particular but non-exclusive embodiment of the invention that is illustrated by way of non-limiting example in the attached drawings, in which:

Figure 1 is a perspective view from above of the weight reduction element disposed on top of a weight reduction reinforcing mesh;

Figure 2 is a perspective view from below of the weight reduction element;

Figure 3 is a side view of the weight reduction element;

figure 4 is a detail of a corner of the weight reduction element and a foot;

figure 5 is a side view of the weight reduction element, in the region of the foot;

Figure 6 is a cross-sectional view taken along the line VI-VI in Figure 5;

Figures 7 and 8 are two side perspective views of a single

Figure 9 is a top view of a foot;

Figures 10 and 11 are two side views of a single

Figure 12 is a top view of a foot attached to a corner of the weight reduction element; figure 13 shows figure 1 in perspective view from below.

In the embodiments illustrated below, individual features shown in connection with specific examples may be interchanged with other different features existing in other embodiments.

With reference to the figures, the reference number 1 generally designates a weight reduction element for the construction industry, constituted by a disposable formwork 2, substantially shaped like a truncated pyramid, made from plastic material, particularly adapted for use in the provision of reduced-weight bi-directional plate-slab roofs (also known as hollow-body or hollow-cell plate-slab roofs or by other names) or reduced-weight foundation beds through the addition of framing booster 3.

The disposable formwork 2 is internally hollow and is provided with a substantially flat upper surface 4, from which side surfaces 5 of different shapes extend and are joined at the tip by a first perimetric ridge 6 defining a lower opening 6a.

It should be noted that the weight reduction element can also be composed of a "closed casing", that is, a casing made up of two half-shells (which can be of different heights), such as, for example, contained in patent no. ° 1412724 filed in the name of this applicant.

The perimetric ridge 6 is such that it allows the coupling of the two half-shells, mentioned above, so as to obtain a weight reduction element, internally hollow, but in the form of a "closed shell". The feet, in this case, no longer extend in one position along the perimetric ridge 6 but are associated close to the corners 107 of the upper surface 4 (for example, of the lower half-shell constituting the formwork 1). .

Said lateral surfaces 5 have a structure of chosen shape and, in any case, have a chosen inclination, all in order to make it possible to stack them with other similar formworks.

The expendable form 2 is internally hollow and open downwards, due to the fact that it lacks a surface connecting the perimetric ridge 6.

The disposable formwork 2, at the corners 7 and internally with respect to the first perimeter ridge 6, can be detachably associated with feet 8 of a chosen height which, once associated with the disposable formwork 2, protrude on the opposite side to the of the upper surface 4.

The feet 8 determine the formation according to a determined thickness of the lower slab (intrados slab) by virtue of the flow of concrete under the weight reduction element.

The feet 8 have a parallelepiped shape, preferably conical with a circular base, and are preferably hollow inside.

Therefore, in the corners 7 of the disposable formwork 2, first preferably circular holes 9 are provided, close to which there are coupling means 10 for temporarily stable interconnection with gripping means 11 associated with the free upper end 12 of each foot 8.

For a "closed shell" form, close to the corners 107 of the top surface 4, a coupling means 110 (stylized in Figure 1) which is similar, in form and function, is associated with the coupling means 10.

The coupling means 10 allow a connection that is stable with the disposable formwork 2 and, at the same time, removable for an optional stable repositioning of the foot 8 in another angular position.

At the free upper end 12, there is a flat disk 13 with a flat circular shape that is arranged, once the foot 8 is engaged with the disposable form 2, against a complementary shaped bottom 14 surrounding each first hole 9.

The temporary coupling means 10 are constituted by a second annular ridge 15, which surrounds the hole 9 and protrudes upwards with respect to it, is of a chosen height and is arranged concentrically and internally to a cylindrical tongue 16 which is provided on each corner 7 close to the first perimeter ridge 6.

The gripping means 11 are associated with a third annular ridge 17 that protrudes axially both with respect to the first hole 9 and with respect to the flat disc 13; said third annular ridge 17 presents a outer diameter which is smaller than the inner diameter of the second annular ridge 15 and a height slightly greater than the latter, so that the tip 18 of the third annular ridge 17 protrudes beyond the corresponding tip of the second annular ridge 15.

The third annular ridge 17 advantageously has an angular extension of approximately 270°.

The gripping means 11 are associated with the tip 18 and are constituted by one or more teeth 19 which protrude radially and externally with respect to the third annular ridge 17 and interact abutment with the underlying second annular ridge 15.

Advantageously, the teeth 19 are three in number and are spaced angularly apart from one another by approximately 120°. Alternatively, it is possible to provide a single tooth running through 270° of the third annular ridge 17.

Each foot 8 has a conical body 20 that protrudes below and eccentrically with respect to the flat disk 13. The central axis 21 of the flat disk 13, which coincides with the axis of the first hole 9, is therefore quite different from the central axis 22 of the body 20; It follows from this that the lower end 23 of the body 20 is axially displaced with respect to the gripping means 10.

The body 20 can have the structure of the desired shape; for example, it can be composed of two or more elements with two or more independent lower ends 23, for example, so as to define a "spider-legged" type of the shaped structure.

This means that, once the third annular ridge 17 of each foot 8 is inserted into the first hole 9, the foot 8 can be rotated until the lower end 22 of the body 20 is positioned at the desired point, so that it does not interfere with the reinforcement frames arranged below the weight reduction element.

The connection between each foot 8 and the disposable formwork 2 is obtained by making one or more of the teeth 19 interact with the second annular ridge 15.

Advantageously, material gaps 24 are provided in the flat disc 13 in each overlapping tooth 19 in order to facilitate the connection between the components.

Advantageously, the third annular ridge 17 has a partial cover 25 in which adapted through-seats 26 are provided perimetrically and are provided in the teeth 19.

In addition, the possibility, not according to the claimed invention, of using a single foot 8 arranged on the upper surface 4, preferably in a central region thereof, should be noted; In this case too, a first adapted circular hole 9 will be obtained, next to which there will be temporary coupling means 10 for rotating interconnection with gripping means 11 associated with the free upper end 12 of the foot 8 that will have a chosen height and they can conveniently be displaced axially from the lower end 23. In practice, it has been found that the invention has fully achieved the intended purpose and objectives, having obtained an invention that makes it possible to obtain, using disposable formworks 2 of plastic material, a weight-reduced roof or high-thickness, weight-reduced foundation beds with considerable savings in concrete based on an intentional and contingent footing height, even when this is different from the design height.

The quick and easy interchangeability of the 8 feet makes it possible to limit the number of versions that are provided and to contain the production and management costs of the formwork, since it is possible to provide a 2 formwork of chosen height and 8 feet of different heights to match with formwork 2 depending on the chosen thickness of the intrados slab.

It is also possible to remedy possible unforeseen and frequent circumstances that arise on site or design errors at the last minute, simply replacing only the feet of a chosen height, without necessarily having to replace the entire weight reduction element.

Furthermore, the invention can be used while avoiding points of interference between the free lower ends 23 of the feet 8 or the surfaces 20 of the feet 8 and the reinforcing frames 3 arranged below the weight reduction element, while the formwork 2 is it always rests optimally with respect to the intended rest surface on the slab roof and exactly in the location specified in the project.

The displacement of the lower end 23 of the foot 8 with respect to the gripping means 11 of the foot and the temporary coupling means 10, 110 of the formwork 2 allows, by way of a small rotation imparted to the foot 8 in its grip seat 11, a slight displacement of its lower end 23: in this way, the formwork 2 makes it possible to avoid any points of interference between the free lower ends 23 of the feet 8, or the surfaces 20 of the feet 8, and the reinforcing frames 3 arranged below the weight reduction element 1, thus always being possible to rest the formwork 2 optimally with respect to the intended resting surface on the slab deck and exactly in the location specified in the project.

Naturally, the materials used, as well as the dimensions of the individual components of the invention may be more relevant depending on the specific requirements.

The various means of achieving certain different functions definitely need not co-exist only in the shown embodiment, but may be present in many embodiments, even if they are not shown.

Therefore, for example, the stable repositioning of the foot 8 in another different position with respect to an initial angular position with respect to the disposable formwork 2 can be obtained by providing the coupling means 10 or the foot 8 with removable diaphragms that can be respectively associated with the gripping means 11 or with the coupling means 10.

This could allow for at least a single repositioning of the foot.

Features indicated above as advantageous, expedient or the like can also be omitted or replaced by equivalent features.

The disclosures of Italian patent application no. 102016000083287 (UA2016A005981) are those for which this application claims priority.

When the technical characteristics mentioned in any claim are followed by reference symbols, those reference symbols have been included for the sole purpose of increasing the intelligibility of the claims and, consequently, said reference symbols do not have any limiting effect on the interpretation. of each element identified by way of example by said reference symbols.

Claims (10)

1. Weight reduction element (1) for the construction industry, made up of at least one disposable formwork (2), substantially shaped like a truncated pyramid, which is hollow and has a closed upper surface (4) and a lower opening (6a), said weight reduction element comprising feet (8) of a chosen height, each foot (8) presenting a lower end (23), opposite a free upper end (12), characterized in that - at least close to some corners (7) of the formwork that are adjacent to said lower opening (6a), or - close to corners (107) of the formwork (2) of said upper surface (4) and associated with said formwork, coupling means (10, 110) are provided, such that said coupling means (10, 110) are stable and are substantially rotatably interconnected, temporarily, with gripping means (11) associated with the free upper end (12) of said feet (8), and the lower end (23) of each foot (8) being axially displaced with respect to the gripping means (11) and said temporary coupling means (10, 110), respectively. Element according to claim 1, wherein said expendable formwork (2), proximate to said corners (107) of said top surface (4), is detachably associated with said coupling means (110) for temporary interconnection stable with said gripping means (11). Element according to claim 1, comprising the internally hollow disposable formwork (2) provided with said upper surface (4), substantially flat, from which side surfaces (5) of different shapes extend and are joined at the tip by a first perimetric ridge (6), which defines said lower opening (6a), so that said disposable formwork (2), at the corners (7) of the formwork that are adjacent to said lower opening and internally with respect to said first perimetric ridge (6), is detachably associated with said feet (8), of a selected height, which protrude on the opposite side with respect to said upper surface (4). Element according to claim 1 or 2, wherein in said corners (7, 107) of the formwork (2) which are adjacent to said lower opening (6a) or said formwork corners of said upper surface (4), are First holes (9) are provided, which have a regular or irregular polygonal flat shape or are circular, close to which are said coupling means (10, 110), a flat disk (12) being provided at each free upper end ( 13) with a flat circular shape, which abuts against a complementary shaped bottom (14) surrounding each of said first holes (9). Element according to claim 4, in which said coupling means (10, 110) are constituted by a second annular ridge (15), which surrounds said hole (9) and protrudes upwards with respect to it, is of a chosen height, and is arranged concentrically and internally to a cylindrical tongue (16), which is provided on each of said corners (7, 107) close to said first perimetric ridge (6). Element according to claim 5, in which said gripping means (11) are associated with a third annular ridge (17), which protrudes axially both with respect to said first hole (9) and with respect to said flat disk ( 13), said third annular ridge (17) presenting an outer diameter that is less than the inner diameter of said second annular ridge (15) and a height slightly greater than the latter, so that a tip (18) of said third ridge ring (17) protrudes beyond the corresponding tip of said second ring ridge (15). Element according to claim 6, in which said gripping means (11) are associated with said tip (18) and are constituted by one or several teeth (19) that protrude radially and externally from said third annular ridge (17). and abuttingly interact with said underlying second annular ridge (15). Element according to claim 4, in which each of said feet (8) has a substantially conical body (20) that protrudes below and eccentrically with respect to said flat disk (13), the central axis (21) being of said flat disk (13), which coincides with the axis of said first hole (9), different with respect to the central axis (22) of said body (20), so that said lower end (23) of said body ( 20) is axially displaced with respect to said gripping means (11) and said coupling means (10, 110). Element according to claim 6, wherein once said third annular ridge (17) of each of said feet (8) is inserted into said first hole (9), rotation can be imparted to said foot (8) until said lower end (23) of said body (20) is arranged at the selected point so as not to interfere with the reinforcing frames (3) arranged below said weight reduction element (1). Element according to claim 7, in which hollows (24) of material are provided in said flat disk (13) in each of said overlapping teeth (19), said third annular ridge (17) presenting an angular extension of approximately 270° and said teeth (19) being three and being angularly spaced from one another by substantially 120°.