US20040056172A1

US20040056172A1 - Modular elements for formworks

Info

Publication number: US20040056172A1
Application number: US10/450,604
Authority: US
Inventors: Ezio Sedran
Original assignee: Individual
Current assignee: Individual
Priority date: 2000-12-12
Filing date: 2001-12-05
Publication date: 2004-03-25
Also published as: WO2002048479A2; IT1315769B1; CA2431356A1; AU2002217434A1; ITPD20000278A1; EP1341978A2; WO2002048479A3

Abstract

The invention is a new system of formworks for concrete casting, comprising various elements connected to one another for the construction of any building structure in concrete, such as foundations, plinths, reversed beams, straight and curved walls, pillars, floors, beams having the same thickness as the floor, short beams and cantilevers. These elements comprise a single-piece panel made of a plastic material (thermoformed polymers), practically smooth on one side and provided with edge ribs along the four sides on the other side, said ribs being provided with holes and/or slots for the connection with adjacent modular elements, said single-piece panel being also provided with ribs for connecting said edge ribs, as well as pins and centering cones, connection wedges, angle sections, load distribution crosses, trapezium-shaped supports, flat bars with plane connection elements, locking blocks, cross support, extractor.

Description

RELATED U.S. APPLICATIONS

Not applicable.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

Not applicable.

REFERENCE TO MICROFICHE APPENDIX

Not applicable.

FIELD OF THE INVENTION

The present invention concerns building equipment and in particular it concerns a new set of modular elements that, when assembled by means of the appropriate accessories, make up formworks suitable for the construction of concrete structural elements.

BACKGROUND OF THE INVENTION

At present modular formworks are available, which comprise a metal structure (steel or aluminum) that serves to counteract the thrust exerted by concrete; a plane panel, in most cases made of plywood and having the function to contain and give shape to concrete is fixed to this metal structure by means of screws and/or rivets.

The metal structure is constituted by section bars with constant section welded to one another, the shape and thickness of which are selected according to the maximum stress (thrust exerted by concrete) to which the modular element comprising the formwork is subjected. Therefore, in all the points in which the force exerted is lower, the quantity of material present in the section bars used is excessive, with the negative consequence that the total weight of the modular element is too high, as well as its cost. It is just the excessive weight that makes it impossible to use this type of formworks for the construction of horizontal structures, and furthermore due to their high cost small companies cannot even afford to buy them. Finally, it is important to take in consideration also the accessories required for the assembly and use of this type of formworks, in fact most of them are made of steel and/or cast iron and this further increases either the weight and the cost of the elements used.

The plane panel is mainly constituted by several layers of wood glued to one another, whose terminal surfaces are covered with phenolic resins, in order to protect them from the action of water. Nevertheless, water corrodes them until they rot, either because the panel edges are not protected and because their use in building sites causes abrasions in the phenolic resins, through which plenty of water can easily penetrate.

It is to eliminate the drawbacks mentioned above that a new set of modular elements has been designed and implemented for the construction of formworks in thermoformed materials (thermoplastic polymers) with the thermoinjection technique, that is, through the injection of molten thermoformed polymers into a metal mould.

These innovative formworks differ from those used at present mainly for the following characteristics:

universality, that is, the possibility of constructing any type of vertical and/or horizontal structure, like foundations, plinths, reversed beams, rectilinear and/or curved walls, floors, short beams, beams having the same thickness as the floor, cantilevers and pillars;

lightness, since the materials used, which at present are not utilized for the construction of formworks, are characterized by low specific weight and the production technique, that is, the injection of thermoformed polymers (polyamides, etc.) into a steel mould makes it possible to use the quantity of material that is sufficient and necessary to counteract the forces to which the formworks are subjected, forces that vary considerably in the different points of the formworks and depending on their different applications; furthermore, the low weight of the element with the largest size (less than 33 kg) allows the formwork to be manually used by one person only, in full compliance with the latest standards, and also allows it to be used for floors and other horizontal building structures, while for its construction the modular elements must be manually lifted to the height of the structure to be built, before and after its construction;

low cost, since the material used and the production technique make it possible to considerably reduce production costs and, consequently, selling prices, with the positive result that these formworks can be purchased even by small companies that today cannot afford to buy this equipment since its high cost and limited use do not permit depreciation;

easy disposal thanks to the fact that the material is recyclable, in fact thermoformed polymers can be recycled easily and at low cost through trituration and/or thermal recovery technique;

long life, since the material used is not affected by the corroding action of water and cannot be chemically attacked by concrete.

The object of the invention is the implementation of an optimal formwork system, provided with stiffening and coupling elements obtained in a single unit with the plane structure itself. Practically, the invention concerns single-piece elements obtained by means of plastic moulding, whose accessories (pins, wedges, coupling and fastening elements, etc.) are preferably produced with the same techniques and the same material, if necessary reinforced with fibers, with the consequence that the advantages described above are extended to the entire system.

Another aim of the invention is the implementation of elements that can be easily recycled and disposed of through trituration or thermal recovery.

A further goal is the construction of lighter elements compared to those presently used for formworks, with maximum weights considerably lower than 33 kg, which therefore can be easily handled even by one person only.

Another goal is the construction of elements having the same weight but larger size compared to those presently available on the market, with evident savings in laying times.

Another aim is the implementation of elements to which, if necessary, it is possible to fix wooden elements by means of rivets.

A further aim of the invention is the implementation of a versatile system that can be used in all building applications: plinths, foundations, walls, pillars, circular walls, floors, beams having the same thickness as the floor and/or short beams, etc. The single-piece element is preferably made of a single material, or if necessary of two different materials, for example nylon (polyamide) for the ribbing and the structure and polyethylene for the plane part, still remaining a single piece, which is due to the application of the thermoforming technique.

BRIEF SUMMARY OF THE INVENTION

The new modular elements for formworks for concrete casting mainly comprise a panel in thermoformed plastic material, preferably polypropylene, with ribbing either along the four edges and across the panel width. In particular, the ribs along the edges are provided with holes for the connection with the adjacent modular elements and slots and/or depressions that make it possible to use a lever to detach the formworks from concrete, which otherwise would be difficult due to the suction effect resulting from the process.

It is possible to lighten and stiffen the modular element through the insertion of metal and/or fibre cores, through the production of cavities with the injection of gas, through the creation of cavities filled with foamed polymers and finally through the incorporation, obtained with appropriate couplings, of one or more removable metal structures, so that the singlepiece modular element may always be easily recycled and disposed of.

The new set of modular elements makes it possible to quickly construct formworks, even with irregular shape (connection angles different from 900), and can be easily and quickly assembled and disassembled.

Said single-piece elements and the relevant accessories can be even made in different colors or partly different, even fluorescent colors.

The difference in color, which today cannot be achieved with any other system, except for very expensive systems with limited duration, offers great advantages for the identification of the element class.

In fact, in common applications for the construction of formworks these elements can be subjected to different loads depending on their position, the intended use and the formwork filling speed (hydrostatic force). For this purpose the different colors can be used to identify the class to which the element belongs (capacity 40-60-80 KN/sqm). Furthermore, the capacity and other applicative technical data, such as the concrete filling time/fluidity diagram, are impressed on the element due to the shape of the mould itself.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

The following is the description of one among many possible applications of the new system for the construction of formworks and its main elements, illustrated in the enclosed drawings, wherein: [0027]
FIG. 1[0028] a is an upper perspective view for a back side of a modular panel of the present invention.
FIG. 1[0029] b is another upper perspective view from a front side of the panel.
FIG. 2[0030] a is a perspective view of a panel made of two materials.
FIG. 2[0031] b is a side elevational view of the panel of FIG. 2a.
FIG. 2[0032] c is a top plan view of the panel of FIG. 2a.
FIG. 2[0033] d is a cross-sectional view across line A-A in FIG. 2b.
FIG. 3[0034] a is a perspective view of a panel with metal cores and fiber cores.
FIG. 3[0035] b is a side elevational view of the panel of FIG. 3a.
FIG. 3[0036] c is a top plan view of the panel of FIG. 3a.
FIG. 3[0037] d is a cross-sectional view across line A-A in FIG. 3b.
FIG. 4[0038] a is a perspective view of a panel with cavities to lighten and stiffen.
FIG. 4[0039] b is a side elevational view of the panel of FIG. 4a.
FIG. 4[0040] c is a top plan view of the panel of FIG. 4a.
FIG. 4[0041] d is a cross-sectional view across line A-A in FIG. 4b.
FIG. 5[0042] a is a perspective view of a panel with cavities of foamed polymers.
FIG. 5[0043] b is a side elevational view of the panel of FIG. 5a.
FIG. 5[0044] c is a top plan view of the panel of FIG. 5a.
FIG. 5[0045] d is a cross-sectional view across line A-A in FIG. 5b.
FIG. 6[0046] a is a perspective view of a panel with metal structures and removable couplings.
FIG. 6[0047] b is a side elevational view of the panel of FIG. 6a.
FIG. 6[0048] c is a top plan view of the panel of FIG. 6a.
FIG. 6[0049] d is a cross-sectional view across line A-A in FIG. 6b.
FIG. 7[0050] a is a perspective view of a wedge to align panels of the present invention.
FIG. 7[0051] b is a perspective view of a centering cone of the present invention.
FIG. 7[0052] c is a perspective view of a pin of the present invention.
FIG. 7[0053] d is a perspective view of another pin of the present invention.
FIG. 8[0054] a is a perspective view of an angle section of the present invention.
FIG. 8[0055] b is a perspective view of a hinged section of the present invention.
FIGS. [0056] 9(a-f) are cross-sectional, bottom plan, another cross-sectional, an upper perspective, another upper perspective and a side elevational view of a load distribution cross of the present invention.
FIGS. [0057] 9(g-h) are perspective views of alternative embodiments of the load distribution cross.
FIGS. [0058] 10(a-b) are perspective views of an assembly of panels of the present invention and an alternative embodiment with load distribution crosses.
FIG. 10[0059] c is a detailed perspective view showing a wedge, cones and pins.
FIG. 11[0060] a is a top plan view of a flat bar of the present invention.
FIG. 11[0061] b is a side elevational view of a triple purpose block of the present invention.
FIG. 11[0062] c is an upper perspective view of the triple purpose block.
FIG. 11[0063] d is an upper perspective view of another pin of the present invention.
FIG. 11[0064] e is a perspective view of a sliding block.
FIGS. [0065] 12(a-b) are perspective and exploded perspective views of panels connected to linear elements.
FIGS. [0066] 12(c-e) are detailed sectional, exploded top plan and top plan views of a pin in the panel connected to the linear elements.
FIG. 12[0067] f is a side elevational view of the linear element and cross-sectional view of the linear element.
FIG. 13[0068] a is a perspective view of a plan connection element of the present invention.
FIG. 13[0069] b is a perspective view of a cross support of the present invention.
FIG. 14 is a perspective view of an assembly of panels, blocks, bars and pins. [0070]
FIGS. [0071] 15(a-b) and FIGS. 16(a-c) are perspective views of a panel with ribs in multiple alternative embodiments.
FIGS. [0072] 17(a-b) are perspective and exploded perspective views of a right-angled positioning bracket and pin.
FIGS. [0073] 18(a-b) are perspective views of the extractor of the present invention and the extractor at work.
FIG. 19 is a perspective view of panels processed to reproduce grain of wood. [0074]
FIG. 20[0075] a is a detailed view of a folded edge of a panel.
FIG. 20[0076] b is a perspective view of a support block of the present invention.
FIG. 20[0077] c is a perspective view of an assembly of panels with folded edges and support blocks.
FIG. 21 is a perspective view of panels in a pillar formation and a detailed view of the cone, pin and wedge in the pillar. [0078]
FIG. 22 is a perspective view of panels in a floor or beam formation and a detailed view of the cross support. [0079]
FIG. 23 is a perspective view of an assembly for foundation plinths. [0080]
FIG. 24 is a perspective view of an assembly in a restricted space. [0081]
FIGS. [0082] 25(a-b) are side elevational views from opposite sides of a walls with angles.
FIG. 25[0083] c is a top plan view of the walls of FIGS. 25(a-b).
FIGS. [0084] 26(a-c) are side elevational views of panels with ribs in a crossing arrangement, curved ribs and diagonal ribs.
FIGS. [0085] 27(a-b) are perspective views of panels with coffers and an assemble of panels with coffers of the present invention

DETAILED DESCRIPTION OF THE INVENTION

FIGS. [0086] 1 (a-d) show a rectangular modular panel (P) having smooth surface (Pl) on one side and ribs (Pnb, Pnl) on the other side, either along the four edges (Pnb) and across the panel (Pnl), wherein said ribs may have any suitable direction with respect to the edges themselves.
In particular, the ribs (Pnb) along the edges are provided with holes (Pf) for the connection with the adjacent modular elements. In particular, said panel is also provided with several slots (Pfb) positioned near the edge and with four depressions (Pfc) on the comers, within which a lever of the type commonly used in building sites can be easily inserted to facilitate the extraction of the panel from concrete, thus overcoming the suction effect. [0087]
The plane surface (Pl) is provided with holes (Pff) that serve to house a threaded bar for the purpose of counteracting the concrete thrust produced when the latter is cast into the formwork. [0088]
FIGS. [0089] 2 (a-d) show a rectangular modular panel where the ribs (Pnb, Pnl) are made with one type of material, for example nylon (polyamide), while the plane surface (Pl) is made with another type of material, for example polypropylene.
FIGS. [0090] 3(a-d) show a rectangular modular panel—presented as one among many possible applications—provided with one or more metal cores (Am) inserted in the ribs (Pnb, Pnl) and one or more fiber cores (Af) inserted in the plane side (Pl).\
FIGS. [0091] 4(a-d) show a rectangular modular panel—presented as one among many possible applications—provided with some cavities (Ca) designed to serve as structural lightening or stiffening elements and obtained through the injection of gas in the connection points between the ribs (Pnb, Pnl) and the plane side (Pl).
FIGS. [0092] 5(a-d) show a rectangular modular panel where, by way of example, the ribs (Pnb, Pnl) are lightened and stiffened by cavities (Cs) filled with foamed polymers.
FIGS. [0093] 6(a-d) show a rectangular modular panel where, by way of example, the ribs (Pnl) are stiffened and strengthened by a metal structure (Sm) that is incorporated and held by means of easily removable couplings (Pag), so that it can be easily removed and the panel maintains the features that make it easy to recycle and/or dispose of.
The example illustrated in the figure does not exclude the possibility of extending this technique also to the perimetric ribs (Pnb). [0094]
FIGS. [0095] 7(a-d) show a centering cone (C), two pins (U) and one wedge (I) to be used to join and align several modular panels M, preferably made with the same materials and construction techniques.
The pins (U) are elements having cylindrical body (Uc), large and flat head (Ut) and a tapered part (Uv) between head (Ut) and body (Yc). The cylindrical body (Uc) of said pins (U) is provided with longitudinal rectangular slots (Uf). [0096]
The pins (U) constituted as described above are suitable for being introduced in the holes (Pf) of the adjacent edge ribs (Pnb) of contiguous panels (P). [0097]
The inner diameter and the taper of the centering cones (C) are such as to permit their insertion in the pins (U) applied between two modular panels (P) from the side opposite their head (Ut) and to allow the tapered part to rest against the hole (Pf) of the edge rib (Pnb) of the panel (P). [0098]
The wedge (I) is a generically flat, trapezium-shaped element, suitable for being inserted in the slots (Uf) of the pins (U), so that they do not come off the centering cones (C) and the edge ribs (Pnb) of the panels (P). [0099]
FIG. 8 shows an angle section (A) for right-angled connections and a hinged angle section (V) for non-right-angled connections, preferably made with the same materials and construction techniques. [0100]
The angle section (A) that joins and connects various modular panels (P) at right angles comprises a square section, solid and/or hollow standard (Am), provided on two contiguous sides with pins (Ap) arranged orthogonally with respect to the side of the standard (Am). Said pins (Ap) of the standards (Am) have the same features, except for the head, as the above mentioned pins (U). Said angle section (A) can be used to make either internal angles and external angles, according to the direction in which the panels (P) are fixed. A further, essentially parallelepiped-shaped element (Au) is also provided, which is suitable for being inserted in the hollow head of said angle section (A), in such a way that it acts as connection element between two superimposed angle sections (A). [0101]
The angle section (V) that joins and connects various modular panels (P) comprises two strips (Vb) hinged to each other on their longer sides. Each one of the two strips (Vb) is provided with pins (Vp) that are arranged orthogonally with respect to the strips (Vb) and have the same features as the above mentioned pins (U), except for the head. [0102]
FIGS. [0103] 9(a-h) shows a load distribution cross (Y), comprising a crossshaped body (Yc), ribs (Yn, Yp), a hole (Yf), a depression (Yr) and a housing (Ys).
FIGS. [0104] 10(a-c) show an example of assembly of some of the above mentioned modular elements to be used in a formwork for the construction of a concrete wall. In this example the following components are used: panels (P) with varying dimensions, 90° angle sections (Ai, Ae), pins (U), centering cones (C), fastening wedges (I) and other known elements. It can be clearly observed that the angle sections (A) may be used indifferently for internal (Ai) and external angles (Ae).
The same table shows the load distribution cross (Y) positioned at the joint of the panels (P), so that its hole (Yf) coincides with the hole (Pff) present in the panel. A threaded metal bar (commonly used in the formworks presently available on the market) is inserted in these holes, in order to counteract the thrusting force of the concrete cast in the formwork. The load distribution cross (Y) serves to align adjacent panels (P), to maintain the linearity of the ribs (Pnb, Pnl) subjected to the thrusting force exerted by the cast concrete and to distribute the compression force resulting for said thrust. [0105]
FIGS. [0106] 11(a-e) show a triple-purpose block (ZT), a sliding block (ZS), a flat bar with holes (B) and a pin (H), preferably made with the same materials and construction techniques.
The triple-purpose block (ZT) comprises a parallelepiped-shaped element provided with a hook projection (ZTg) on one side, with a hole (Zte) and with through slots (ZTf) on the various sides. The hook projection (ZTg) is suitable for joining the block (ZT) with the ribs (Pnb) present on the panels (P), while the hole (Zte) houses the pin (H) and the through slots (ZTf) house the bars with holes (B). [0107]
The sliding block (ZS) comprises a parallelepiped-shaped element provided with a hook projection (ZSg) on one side, with a hole (Zse) and a slot (ZSf) orthogonal with respect to one another. The hook projection (ZSg) is suitable for joining the block (ZS) with the ribs (Pnb) present on the panels (P), while the hole (ZSe) houses the pin (H) and the through slot (ZSf) houses the bar with holes (B). [0108]
FIGS. [0109] 12(a-f) show said panels (P) with two linear elements (T) with trapezium-shaped sections, said linear elements being interposed and positioned so that they are adjacent to each other along the inclined side. These elements (T) are provided with through holes (Tf) coinciding with the holes (Tf) of the opposed element (T), wherein a locking pin (Pp) is inserted in said holes (Tf). Said linear elements (T) with trapezium-shaped section are particularly useful in the form stripping phase, when they are released from each other by extracting the through pin (Pp). In any case, these elements ensure comfortable form stripping operations even in difficult situations, for example in the restricted space of a lift well.
The detail, illustrated in the same figure, shows that the space left free by the linear elements (T) after their extraction is sufficient to allow the panel (P) to be detached from the angle section (A) through the rotation of the panel (P) itself. [0110]
FIGS. [0111] 13(a-b) show a cross support (X) for the construction of floors, beams having the same thickness as the floor, short beams, shelves, etc., preferably made with the same materials and the same construction techniques, comprising a parallelepiped-shaped element (Xc) provided with two cuts (XI) orthogonal to each other and suitable for housing the ribs (Pnb, Pnl) of one, two, three or four modular panels (P). The lower surface is provided with a cylindrical pin (Xb) and with holes (Xa) that permit the coupling with the upper plate of the traditional metal props commonly used in building sites. In particular, the pin (Xb) fits into the hole at the center of the prop plate, while the holes (Xa) allow the support (X) to be fastened to the prop plate by means of a self-threading screw.
The figure shows also a plane connection element (M) for bars with holes (B), comprising two plane parts (Mp)joined by a transversal part (Mt), with dimensions and distances suitable for housing the ends of two bars with holes (B) that are anchored to the plane connection element (M) by inserting the pin (H) in the corresponding holes. The plane connection element (M) serves to extend the length of the bars with holes (B). [0112]
FIG. 14 illustrates an example of use of panels (P), blocks (ZT), bars (B) and pins (H), where it is possible to observe that the blocks (ZT) and the bars (B) can be easily adapted to specific types of assembly and different combinations. [0113]
FIGS. [0114] 15(a-b) and 16(a-c) show five construction examples of modular panels (P) having different ribbing (Pnb, Pnl), either along their four edges (Pnb) and on the panel (Pnl). These figures point out one of the characteristics distinguishing these modular elements from those used at present, that is, the opportunity to construct modular elements distributing the material in the points subjected to most stress, instead of welding metal bars with constant section.
FIGS. [0115] 17(a-b) show a right-angled positioning bracket (S), preferably made with the same materials and construction techniques, provided with a through hole (Sf) and suitable for being applied to the modular panels (P) by means of the pin (Sp), in order to keep them perfectly orthogonal to each other and to counteract the thrusting force of concrete, for example when making the perimeters of floors and/or beam and slab rafts. Furthermore, the lateral edges are provided with several holes (Sb) that allow the positioning bracket (S) to be fixed to the support surface through riveting.
An example of application of the positioning bracket (S) is provided in the same figure. [0116]
FIG. 18 shows an extractor (E) for the wedges (I), preferably made with the same materials and construction techniques, comprising a rod (Ea) at whose ends there are a flat head (Et) and a C-section head (Ec) suitable for coupling with the flat head of the wedges (I). Around the rod (Ea) of the extractor there is a sliding cylindrical element (Em) with appropriate weight, even made of metal. [0117]
The same figure shows the use of the extractor (E), whose C-shaped head (Ec) is coupled to the head of the wedge (I) to be extracted, while successively the sliding element (Em) slides on the rod (Ea) of the extractor (E) thanks to the repeated percussion of the flat head (Et) of the extractor (E) itself. [0118]
FIG. 19 shows some examples of modular panels (P) whose surface (PI) opposite the ribs (Pnb, Pnl) is processed in such a way as to reproduce, for example, the grain of wood. [0119]
FIGS. [0120] 20(a-b) illustrate the concrete reinforcement of foundations, short beams, shelves, etc., comprising spaced panels (P) that may be even positioned at non-modular distance, and wherein the difference is compensated for by an appropriate plane element, preferably made with the same materials and construction techniques, with folded edge (L). In this example the thrusting force exerted by concrete is counteracted, at the base, by blocks (K) fixed to the support surface with rivets passing through the holes (Kf), said blocks holding the support edge of the panel (P) through the head (Kt), while at the top the thrusting force is counteracted by the bars with holes (B) fixed to the sliding blocks (Zs) with the pin (H). The coupling of the sliding blocks (Zs) with the panel (P) takes place through the hook projection (ZSg) of the sliding blocks (ZS), which fits into the ribs (Pnb) of the panel (P) and holds them. The lower part of the base block (K) is provided with some depressed sections (Kr) into which a lever is inserted to detach the block from the surface to which it was fixed.
FIG. 21 shows an example of pillar reinforcement, carried out using the same angle sections (A) used for the construction of formworks for masonry applications, said angle-sections being coupled to panels (P) fixed to one another by means of pins (U), centering cones (C) and wedges (I). [0121]
FIG. 22 shows another example of formwork for the construction of floors, short beams, beams having the same thickness as the floor, etc., in particular it shows how the cross support (X) is fixed to the plate (Qt) of the props (Q) commonly used in building sites, that is, by fitting screws into the holes (Xa) of the cross support (X); the figure also shows how the cylindrical pin (Xb) fits into the hole (Qb) of the plate of the metal props (Q) commonly used in building sites. [0122]
FIG. 23 shows an example of application for the concrete reinforcement of foundation plinths, In particular, it shows how the bars with holes (B) can be lengthened as desired by using plane connection elements (M) and pins (H). [0123]
FIG. 24 shows an example of formwork carried out in a restricted space, where it is possible to observe the linear, trapezium section elements (T) sliding on inclined planes, which ensure comfortable form stripping operations even in difficult conditions. [0124]
FIGS. [0125] 25(a-c) show an example of concrete reinforcement of walls with angles different from 90° or circular walls, with hinged angle sections (V) coupled to the panels (P).
FIG. 26 shows a panel (Pi) provided with connection ribs arranged diagonally, a panel (Pii) provided with connection ribs arranged along curved and/or rectilinear lines of force and a panel (Piii) provided with ribs arranged in such a way as to form a square and with central holes for the connection to the opposite panel arranged in such a way as to form a cross. [0126]
FIGS. [0127] 27(a-b) show the panels (P) provided with coffers (Css) sustained by the cross support (X) positioned on the prop (Q) commonly used in building sites.

Claims

I claim:

1. Concrete formwork comprising modular elements consisting of panels (P) of plastic material, having a smooth concrete-facing surface (Pl) and an opposite surface provided with edge ribs (Pnb, Pnl), running along the four edges and having holes (Pf), and with intermediate transverse and/or longitudinal stiffening ribs (Pnl), further comprising connector elements for coupling said panels (P) to each other and/or to other elements, characterized in that said panels (P) are single-piece, thermoformed elements of a single material, e.g. polymer, or of two different materials, e,g, polyamide and polyethylene, and that also the connector elements are made of plastic material.

2. Concrete formwork according to claim 1, characterized in that the panels (P) are thermoformed in a single operation through injection into a mould of two or more types of polymers and/or thermoformable synthetic materials.

3. Concrete formwork according to claims 1 or 2, wherein the edge ribs (Pnl) are provided with slots (Pfb) and/or depressions (Pfc) for the insertion of a form stripping lever.

4. Concrete formwork according to any of the preceding claims, wherein the ribs (Pnb, Pnl), on their whole length, have differentiated height and/or thickness.

5. Concrete formwork according to any of the preceding claims, wherein the transverse stiffening ribs (Pnl) are not positioned orthogonally with respect to the edge ribs (Pnb).

6. Concrete formwork according to any of the preceding claims, wherein the transverse stiffening ribs (Pnl) are arranged on curved and/or straight isostatic lines of force.

7. Concrete formwork according to any of the preceding claims, wherein the smooth concrete-facing surface (Pl) is processed in such a way as to produce grain of wood.

8. Concrete formwork according to any of the preceding claims, characterized in that they panels comprise one or more wide protrusions, commonly referred to as “coffers”, to construct ribbed coffered ceilings.

9. Concrete formwork according to any of the preceding claims, wherein the panels (P) are provided with internal cavities (Ca) obtained through gas injection.

10. Concrete formwork according to claim 8, wherein the cavities (Ca) are filled with foamed polymers.

11. Concrete formwork according to any of the preceding claims, wherein the panels (P) are provided with metal and/or fiber reinforcement cored (Am; Af).

12. Concrete formwork according to any of the preceding claims, wherein said connector elements are plane elements having a folded edge (L) to fit between two near but not adjacent panels (P).

13. Concrete formwork according to any of the preceding claims, wherein said connector elements are pins (U), centering cones (C), and wedges (1) for joining and aligning several panels (P), and wherein each pin (U) has a cylindrical body with rectangular slots (Uf), a wide and flat head (Ut) and a tapered part (Uv) between head and body, and wherein the inner diameter and external taper of the centering cones (C) are such as to permit their insertion into the pins (U) applied between two panels (P) and to allow the tapered part (Uv) to rest against the hole of an edge rib (Pnb, Pnl), and wherein the wedge (1) is a generically plane element in the shape of a trapezium, suitable for being inserted into said slots (Uf).

14. Concrete formwork according to any of the preceding claims, wherein said connector elements are angle sections (A) for the right-angled connection of panels (P), comprising a square section, preferably hollow standard (Arn), provided on two contiguous sides with pins (Ap) which are arranged orthogonally with respect to the standard side and which have a cylindrical body with rectangular slots and a tapered part between head and body.

15. Concrete formwork according to claim 14, wherein the side of said standard (Am) is equal to the thickness of the panels (P),

16. Concrete formwork according to claims 14 or 15, wherein two superimposed standards (Am) are joined by means of a connector (Au) the section of which corresponds to the cavity of the hollow standard (Arn).

17. Concrete formwork according to any of claims 1 to 13, wherein said connector elements are angle sections (V) for joining panels (P), comprising two strips (Vb) hinged to each other on their longer sides, each strip (Vb) being provided with pins (Vp) which are arranged orthogonally to the strip (Vb) and which have a cylindrical body with rectangular slots and a tapered part between head and body.

18. Concrete formwork according to any of the preceding claims, wherein said connector elements comprise a load distribution cross (Y) constituted by a cross-shaped body (Yc), ribs (Yn, Yp), a hole (Yf), a depression (Yr) and a housing (Ys).

19. Concrete formwork according to any of the preceding claims, wherein said connector elements comprise a linear element (T) with section in the shape of a trapezium or right-angled triangle, provided with holes (Tf) perpendicular to the length of the linear element M which is suitable for being coupled to an Identical corresponding element (T), so that both linear elements can be positioned between the panels (P) of one of the formwork sides.

20. Concrete formwork according to any of the preceding claims, wherein said connector elements are flat bars (B) having holes at regular intervals,

21. Concrete formwork according to claim 20, wherein said connector elements further comprise a plane connection element (M) for said flat bars (B) with holes, said plane connection element (M) being constituted by two flat parts (Mp) connected by a transversal part (Mt), with dimensions and distances that allow the ends of two flat bars (13) with holes to be housed therein and fixed by means of pins.

22. Concrete formwork according to claim 21, wherein said pins are constituted by a cylindrical body (H) with a rounded end and the other end provided with a flat head and a ring just below said flat head.

23. Concrete formwork according to any of the preceding claims, wherein said connector elements comprise a triple-purpose block (ZT) constituted by a parallelepiped-shaped element provided with a hook projection (ZTg) on one side and with through slots and/or holes (ZTf, ZTe) on the various sides, and wherein the hook projection (ZTg) is suitable for joining the triple-purpose block (ZT) with the ribs (Pnb) of the panels (P), and wherein the through slots and/or holes (ZTf, ZTe) present on the various sides are suitable for the insertion of bars (B) with holes and of pins (H) according to claims 17 to 19.

24. Concrete formwork according to any of claims 1 to 22, wherein said connector elements comprise a sliding block (Zs) constituted by a parallelepiped-shaped element provided with a hook projection (ZSg) on one side and with through slots and/or holes (ZSf, ZSe) on the various sides, and wherein the hook projection (ZSg) is suitable for joining the sliding block (Zs) with the ribs (Pnb) of the panels (P), and wherein the through slots and/or holes (Zsf, Zse) present on the various sides are suitable for the insertion of bars (B) with holes and of pins (H) according to claims 18 to 20.

25. Concrete formwork according to any of the preceding claims, wherein said connector elements comprise a cross support (X) for floors, shelves, etc., suitable for being applied to the top of a metal prop and comprising a parallelepiped-shaped element (Xc) provided with two cuts (X) orthogonal to each other and suitable for housing the ribs (Pnl, Pnb) of one, two, three or four panels (P), with a cylindrical pin (Xb) in the lower surface and with holes (Xa) that permit the fastening to the plate of said prop by means of self-threading screws.

26. Concrete formworks according to any of the preceding claims, wherein said connector elements comprise a right-angled positioning bracket (S) provided with a through hole (Sf) and suitable for being applied to said panels (P) by means of a pin (Sp) reaching beyond the holes present in the panel (P), in order to keep them perfectly orthogonal to each other and to counteract the thrusting force of concrete, as well as with holes (Sb) on the lateral edges which allow the positioning bracket (S) to be fixed to a support plane with rivets.

27. Concrete formwork according to any of the preceding claims, wherein said connector elements comprise a base block (K) constituted by a parallelepiped-shaped element provided with a hook-shaped front head (Kt), through holes (Kf) for the fastening to a support surface by means of rivets and with depressions (Kr) in the lower part to facilitate the unriveting by means of levers.