EP1447496B1

EP1447496B1 - Reusable modular formwork for making columns

Info

Publication number: EP1447496B1
Application number: EP04002408.5A
Authority: EP
Inventors: Loris Pegoraro; Mirko Pegoraro
Original assignee: Geoplast SpA
Current assignee: Geoplast SpA
Priority date: 2003-02-13
Filing date: 2004-02-04
Publication date: 2017-04-26
Anticipated expiration: 2024-02-04
Also published as: EP1447496A2; EP1447496A3; SI1447496T1; ES2627554T3

Description

The present invention concerns a reusable modular formwork according to the preamble of claim 1. Pre-shaped circular formworks in cement/concrete or in cardboard are currently used for making columns with a circular section.
Circular cement/concrete formworks are generally made of a cement or concrete tube with a suitable diameter, installed vertically, into which the reinforcement is inserted and the concrete is cast. The cement or concrete tube thus forms the outermost part of the finished column.
These circular concrete formworks present some drawbacks.
Only some diameters of concrete tube are available on the market, and so one is forced to make columns only with those diameters.
Concrete tubes are very heavy and thick, and their installation requires the use of cranes or of lifting machines.
Concrete tubes may crack or even break, both in transport and during installation.
Concrete tubes are very thick and this limits the positioning of the column reinforcement and forces users to make columns with a diameter larger than necessary.
Since the concrete tube forms the outermost part of the column, it requires subsequent surface finishing.
Cardboard circular formworks are composed of a cardboard tube with limited thickness, treated internally with detaching substances or varnishes, so as to prevent the concrete from sticking to the tube itself.
The cardboard tube is installed vertically, then the column reinforcement is positioned inside it and the concrete is cast.
These circular cardboard formworks present some drawbacks.
The cardboard tube has low structural rigidity, as a result the formwork made of cardboard tube must be stabilised with an external structure.
To remove the cardboard formwork, it is necessary to break it, with consequent waste of time.
At present, to make columns with square or rectangular section pre-shaped formworks in plate or wood are used.
These plate formworks are very heavy and thick and their installation requires the use of cranes or lifting machines or several workers.
Periodic maintenance against rust is required and, because of their weight, they are a constant risk for workers. They may also deteriorate, with risk of injury, aggravated by the presence of rust.
On account of their weight, moreover, they cannot have very large dimensions and their usable surface is therefore limited.
Reusable modular formworks are known, made of plastic material, for making concrete or reinforced concrete structures.
These elements are composed of flat walls, with various dimensions, which can be fitted together at right angles and are suitable mainly for making concrete structures with flat surfaces.
To make a square or rectangular column, at least four elements must be positioned and joined together, at right angles, with problems of alignment and perpendicularity.
US5255888A discloses the preamble of claim 1. To overcome the above inconvenient aspects, a new reusable modular plastic formwork has been designed and implemented according to claim 1. The aim of the new reusable modular formwork is to carry out formworks with a circular section which may be easily assembled and dismantled to adapt them to the various static and dimensional requirements. Another aim of the new reusable modular formwork is to be light and stable, that is, with no need of further external support structures.
Another aspect of the new reusable modular formwork that is not covered by the present invention is to be able to be used for various sizes of pillars with circular, elliptical, square or rectangular section, with simple applications of reduction inserts.
Another aim of the new reusable modular formwork is to allow rapid dismantling and storage of the modular formwork. These and other direct and complementary aims are achieved through the implementation of the new reusable modular formwork for making columns with the respective closing key, comprising modular panels and one or more closing keys.
Said panel is semicircular and it is made of plastic, it has a smooth concave internal side and presents on the convex external side various stiffening ribs, both along its perimeter and equidistantly spaced on its wall.
On the perimeter ribbing there are holes for inserting and tightening the closing keys and possible seats, for example hollows, slots or holes, for passing straps. Two or more modular elements are coupled to form a circular portion of formwork and they are fastened together by means of the closing keys inserted and turned in the aligned holes of said two coupled modular elements. Several portions of modular elements are stacked to obtain the modular formwork of the necessary height and fastened together by means of said closing keys. Preferably, suitable inclined surfaces present on the ribbing of the modular elements, in correspondence with the holes and/or on the radial ridges of the closing keys, prevent the involuntary rotation of the closing keys and the separation of the various modular elements, allowing the elements to be fixed together.
In the case of square columns, that is not covered by the present invention, said L- or U-shaped panel or modular element, made of plastic, has the internal sides made of smooth walls as the bottom of the formwork and, on the external side, it presents various stiffening ribs, preferably equidistant, both along its perimeter and on the wall. On the perimeter ribbing there are holes for inserting and tightening the closing keys and/or possible seats, for example hollows, slots or holes, for passing closing straps.
The closing keys are composed of a cylindrical body having at one end a handgrip, preferably at a right angle to said body, and at the opposite end two or more radial ridges, and they are preferably placed at regular intervals.
Two modular elements, according to an aspect not covered by the present invention, are coupled in opposite positions to form a square or rectangular portion of formwork and they are fastened together by means of strapping, or preferably with the closing keys, inserted and turned in the aligned holes of said coupled modular elements. Several portions of modular elements are stacked to obtain the formwork of the necessary height and fastened together by means of said closing keys. Alternatively, two full-height composite half shells are tightened together, after being coupled around the reinforcing rods of the pillar.
Suitable inclined surfaces present on the ribbing of the modular elements, in correspondence with the holes and/or on the radial ridges of the closing keys, prevent the involuntary rotation of the closing keys and the separation of the various modular formworks, allowing the formworks to be fixed together.
There may also be flat or arched, or L- or U-shaped inserts, according to an aspect not covered by the present invention, to be introduced in the formwork to make square or rectangular pillars, with smaller dimensions, or circular pillars.
The characteristics of the new reusable modular formwork will be better explained by the following description with reference to the drawings, enclosed purely as an example without limitation.
Figures 1, 2, 3 illustrate respectively two orthogonal views and an axonometric view of a modular element (M) for making circular columns. The modular element (M) comprises a semicircular panel, made of plastic material, equipped on the convex external side (M2) with various stiffening ribs (Mn, Mo).
Said ribs (Mn, Mo) are evenly distributed all over the surface of the convex side (M2) of the modular element (M). Some ribs (Mo), later called edge ribs (Mo), are placed along the perimeter of the panel of the modular element (M) and have greater thickness and height than the intermediate ribs (Mn).
These edge ribs (Mo) constitute a coupling surface with further modular elements (M) coupled to make the circular shape, and others coupled in alignment and continuation.
On said edge ribs (Mo) there are two series of four holes (Mf), preferably having a circular shape with two or more grooves (Mf1) in diametrically opposite positions.
These holes (Mf) are set along the edge ribs (Mo) in such a way that, when the various modular elements (M) are coupled or aligned, said holes (Mf) are perfectly aligned and regularly spaced.
The surface of the concave internal side (M1) of the new modular element is smooth and is preferably treated in such a way as to prevent the adhesion of concrete.
When two modular elements (M) are coupled together, a length of tube and formwork is made, having the internal diameter equal to the bending diameter of the surface of the concave side (M1) of each modular element and having length equal to the height of each modular element (M).
Coupling together in sequence various modular elements (M), coupled as a tube, a complete formwork is obtained with the desired internal diameter and with a height that is the multiple of the height of each individual modular element (M).
The various modular elements (M) are joined with closing keys (C) as can be seen in figure 4 or according to an aspect not covered by the present invetion with cones, pins, wedges, pegs, straps. The closing key (C) according to an aspect not covered by the present invention is composed of a cylindrical body (C1) with, at one end, a handgrip (C2) and at the opposite end two or more radial ridges (C3).
The body (C1) of the closing key (C) has a generically cylindrical shape, with diameter equal to the diameter of the holes (Mf) in the edge ribs (Mo) of the modular element (M) and length greater than the thickness of two edge ribs (Mo). In particular said body (C1) has an end portion (C11), close to the handgrip (C2), with diameter greater than the rest of the body (C1).
At one end of the body (C1) is the handgrip (C2), that is, a portion at a right angle to the body (C1) which may also have ridges (C21) to ensure a good grip.
At the opposite end of the body (C1) there are two or more radial ridges (C3), diametrically opposite and preferably having the form of a ring-shaped segment. These radial ridges (C3) have length and width such as to pass through the grooves (Mf1) of the holes (Mf) in the edge ribs (Mo) of the modular element (M) when the closing key (C) is inserted in said holes (Mf).
The stable union of the various coupled modular elements (M) is accomplished by inserting said closing key (C) in the holes (Mf) in the coupled edge ribs (Mo) of the modular elements (M), so that according to an aspect not covered by the present invention the radial ridges (C3) of said closing keys (C) pass through both the holes (Mf), and turning said closing keys (C) so that said radial ridges (C3) are not aligned with the grooves (Mf1) of said holes (Mf). It is possible to arrange that said radial ridges (C3) and/or the surface of the edge ribs (Mo) in correspondence with the holes (Mf) are inclined so as to generate compression between the edge ribs (Mo) of the coupled modular elements (M) when the closing key (C) is turned.
The closing keys (C) thus described allow either the union of two modular elements (M) coupled to constitute a tube or the union of modular elements (M) aligned to make the continuation or extension of each other simply by inserting each closing key (C) in the aligned holes (Mf) of the elements (M) placed next to each other and turning it.
Lastly according to an aspect not covered by the present invention there are slots or holes (Fr) located as close as possible to the curved surface or the seats (Sr) for passing or positioning the straps.
The distance between the keys is preferably modular, while the distance between the end keys and the edge is preferably equal to half the module.
The reusable modular element (M) and the respective closing key (C) constituted as described above make it possible to rapidly obtain formworks for circular columns and offer considerable advantages as regards stability, duration and safety.
Figure 4 shows four modular elements (M) according to the invention assembled together and tightened with the keys (C). A modular element (M) for making square or rectangular columns is not covered by the present invention. Such a modular formwork (M) comprises a panel, made of plastic material, having L-shaped section with coupling surfaces (Me) inclined at 45° with respect to the planes (M1), for coupling with an identical modular element (M). This modular element (M) has various stiffening ribs (Mn, Mo) on the external side (M2).
Said ribs (Mn, Mo) are distributed all over the surface of the external side (M2) of the modular element (M).
In particular some ribs (Mo), called edge ribs (Mo), are placed along the perimeter of the panel of the modular element (M) and are preferably thicker and with a bigger height than the intermediate ribs (Mn). These edge ribs (Mo) constitute a resting or coupling surface with further coupled or continuing modular elements (M).
On said edge ribs (Mo) there are holes (Mf), preferably having circular shape and provided with two or more grooves (Mf1) in diametrically opposite positions. These holes (Mf) are set along the edge ribs (Mo) at regular intervals and in such a way that, when the various modular elements (M) are coupled or aligned, the corresponding holes (Mf) of identical coupled elements (M) are perfectly aligned.
The distance between the last holes (Mf), along each edge rib (Mo), and the end of the rib (Mo) itself, is less, preferably half, than the distance between the other holes (Mf) along said rib (Mo) of the modular element (M).
Along the edge ribs (Mo) there may be seats, for example hollows, slots or holes (Rf), for passing closing straps, according to an aspect not covered by the present invention. The surface of the concave internal side (M1) of the new modular element (M) is smooth and is preferably treated in such a way as to prevent the adhesion of concrete.
It is possible according to an aspect not covered by the present invention to carry out modular elements (M) having different dimensions, so as to make it possible to obtain square columns, for example 30x30, or 35x35, or 40x40, etc., or rectangular columns, for example 30x35, 35x45, 30x40, etc.
It is also possible according to an aspect not covered by the present invention to carry out modular elements (M') having L-shaped section and the coupling surfaces (M'e) respectively one at a right angle to and one aligned with the corresponding side of the L-shaped section, or modular elements (M") having U-shaped section and the coupling surfaces (M"e) at right angles to the two ends of the U-shaped section. The modular element with orthogonal walls and L-shaped section may have both coupling surfaces (M'e) of each wall either at right angles or aligned with the corresponding wall of the L-shaped section for coupling with a respective modular element (M). The union between the various modular elements (M) may be accomplished with straps, according to an aspect not covered by the present invention, or according to the invention with the closing keys (C). According to an aspect not covered by the present invention, there may also be flat, L- or U-shaped inserts, or inserts of other shapes, to be inserted inside the element (M) to make pillars with smaller dimensions, or circular pillars. A cross section of an insert (X) with a generic U section according to an aspect not covered by the present invention can be applied to the internal surface (M1) of a modular element (M), so as to allow columns with smaller dimensions to be obtained.
Said insert (X) presents, on its shorter sides (Xm), ridges (Xr) and holes or concave seats (Xo) such as to join two opposing inserts (X). A cross section of an insert (Y) shaped like a panel, according to an aspect not covered by the present invention can be applied to the internal surface (M1) of a modular element (M), so as to allow rectangular columns to be obtained using elements (M) for square columns. In particular, for the application of said flat insert (Y) inside the modular element (M), spacers (D) may be used, suited to maintain said inserts (Y) correctly positioned in the internal concave surface (M1) of the modular elements (M). A cross section of an insert (Z) according to an aspect not covered by the present invention can have a L-shaped section.
Said insert (Z) presents, on its sides (Zm) and/or on the end of its sides (Zm), ridges (Zr) and holes or concave seats (Zo) such as to join exactly two opposing inserts (Z).
It is possible for said insert (Z) to have one side (Z1) of its L-shaped section with different thickness with respect to the other side (Z2). This L-shaped insert (Z), applied to the internal concave surface (M1) of the new modular element (M), makes it possible to obtain square columns with smaller dimensions or, if the insert has sides of different sizes, rectangular columns. A cross section of an insert (E), according to an aspect not covered by the present invention can be applied to the internal surface (M1) of a new modular element (M), suited to obtain columns with octagonal section. A cross section of an insert (F) according to an aspect not covered by the present invention can have an internal surface (F1) in the shape of an arc of a circle for making pillars with elliptical and circular section using the same square formwork (M).
Said insert (F) presents, at its ends, ridges (Fr) and holes or concave seats (Fo) such as to join exactly two opposing inserts (F).
It is possible for said insert (F) to have the internal surface (F1) with different section, for example elliptical, so as to be able to make elliptical columns. A cross section of an insert (R), according to an aspect not covered by the present invention can be applied to the internal surface (M1) of a new modular element (M), suited to allow columns having substantially rectangular or square section with rounded or bevelled corners to be carried out.
The reusable modular element (M) and the respective closing key (C) constituted as described above make it possible to carry out formworks for square, rectangular columns, or columns of any other shape that can be contained according to an aspect not covered by the present invention. The modular elements of the invention (M) are light, impact-resistant, easily transported and easily assembled by simply inserting and turning the closing keys (C) in the coupled edge ribs (Mo).
The modular elements (M) allow the rapid dismantling of the reinforcement, which can be carried out by simply turning and extracting the closing keys (C) that hold the modular elements (M) together. The formworks obtained with the modular elements (M) and the closing keys (C) described above do not need specific external structures to maintain the alignment of the entire formwork since, thanks to the keys, said elements are held together, obtaining a tubular structure that is very stable during casting.
The various inserts (I, X, Y, Z, F, R, E), that are not covered by the present invention and are applicable to the new modular elements also make it possible to obtain columns with different shapes and dimensions with respect to those of the element (M), for example rectangular, circular or elliptical with sharp, rounded or bevelled corners, or columns having the same shape, but smaller dimensions.
In this way, with just one set of elements (M) and some different internal inserts it is possible to make pillars with various shapes and dimensions, according to an aspect not covered by the present invention. A modular element (M) can contain according to an aspect not covered by the present invention 2 inserts (I) for making reinforced concrete pillars with smaller diameter. An insert (I) not covered by the present invention is constituted of two semicircular panels (P), each having an arched wall (Ia) with ribs (In) behind it. Indicated with (Is) and (Ir) are the seats and ridges for the reciprocal coupling of two panels (P) which make up the insert (I), contained and held in the elements (M).

Claims

Reusable modular formwork for making columns, comprising:
at least two modular elements, wherein each modular element (M) has linear development and it is made from plastic material, shaped as part of the perimeter of a column, said modular element with linear development (M) comprising at least one wall with a smooth internal side (M1) as bottom of the formwork and with a not flat outer side (M2), said not flat outer side (M2) further comprising edge ribs (Mo) and intermediate ribs (Mn), wherein the edge ribs (Mo) of the at least one wall present coupling surfaces (Me) for corresponding modular elements with linear development (M), so as to make up a section or closed portion of said reusable modular formwork and wherein said modular element with linear development (M) has holes (Mf) on the edge ribs (Mo), preferably circular in shape with two or more diametrically opposed grooves (Mf1), and wherein said holes (Mf) are located along the edge ribs (Mo) so that, when various modular elements with linear development (M) are coupled or aligned, said holes (Mf) in the various modular elements with linear development (M) are aligned along said coupling surfaces (Me);

at least two closing keys (C) inserted through said holes (Mf), for fastening said various modular elements with linear development (M); each of said modular elements (M) being composed of a semicircular plastic panel comprising on the convex not flat outer side (M2) said intermediate ribs (Mn) and said edge ribs (Mo), wherein the edge ribs (Mo) are placed along the perimeter of the panel of the modular element (M) and each of said edge ribs (Mo) having greater thickness (S1, S2) and height (H1, H2) than the intermediate ribs (Mn), and wherein vertical edge ribs (MoV) are disposed along the vertical edge of the panel and horizontal edge ribs (MoH) are disposed along the horizontal edge of the panel;
characterized in that the height (H1) of the vertical edge ribs (MoV) is greater than the height (H2) of the horizontal edge ribs (MoH).
Reusable modular formwork for making circular columns according to claim 1, characterised in that said edge ribs (Mo) located along the edge of the panel of the modular element (M) have thickness (S1, S2) and height (H1, H2) such as to adhere to the edge ribs (Mo) of an identical coupled or aligned modular element (M).
Reusable modular formwork according to all the previous claims, characterised in that the ribs (Mo, Mn) are directed orthogonally to the coupling surfaces (Me).