EP2053182A2

EP2053182A2 - Reusable modular formwork for making ribbed reinforced concrete floors

Info

Publication number: EP2053182A2
Application number: EP08166885A
Authority: EP
Inventors: Mirco Pegoraro; Massimo Pegoraro
Original assignee: Geoplast SpA
Current assignee: Geoplast SpA
Priority date: 2007-10-22
Filing date: 2008-10-17
Publication date: 2009-04-29
Also published as: EP2053181A3; ITPD20070347A1; EP2053182A3; EP2053181B1; EP2053181A2

Abstract

Reusable modular formwork for making floors, comprising one or more modular and monolithic portal-shaped elements, each comprising a horizontal upper base in contact with the concrete casting and at least two opposing lateral walls in contact with the concrete casting, with lower parts or edges suited to rest on at least one prop or beam or linear temporary bearing element suited to removably support, directly or indirectly, said formwork and the relative concrete casting.

Description

The present invention concerns the equipment for making reinforced concrete floors and in particular it concerns a new type of reusable modular formwork for making ribbed reinforced concrete floors.
Various types of formworks are known, which can be disposable or reusable and are employed for making floors or coverings in general made of cast concrete.
Reusable formworks are known, for example, which are constituted by prefabricated plane panels or elements, in wood, metal or plastic, properly supported by means of temporary bearing structures suited to maintain the formworks in such a position as to form a substantially flat and continuous surface making up the bottom of the formwork, on which concrete is cast.
Said panels and said temporary bearing structure can be removed only after the complete curing of the floor.
Reusable plane formworks are known which are made of a plastic material and comprise a monolithic body with at least one smooth plane surface at the bottom of the formwork, suitable for casting concrete thereon.
Said known reusable formworks are substantially rectangular in plan view, with modular width and length, in the order of 60-100 cm and comprise perimetral ribs at right angles with said plane surface and shaped so as to be suitable for coupling with the adjacent formworks, to which they are integrally constrained by means of suitable fixing devices, like for example bolts, tie rods or other devices.
Said fixing devices are such as to successively allow the formworks to be rapidly dismantled.
Said reusable plastic formworks are particularly appreciated thanks to the fact that they are lighter and easier to handle than wooden panels, compared to which they therefore also require less labour.
Another advantage offered by reusable plastic formworks lies in that they are simple and quick to use and to clean, and also in that they last longer.
A further advantage is represented by the fact that, once said reusable plastic formworks have been removed, the lower surface of the floor is smooth and well finished, differently from what happens when wooden panels or disposable foam formworks are used.
The main problem posed by the known reinforcing systems lies in that the formworks used must remain in place until the curing of the floor is complete and therefore cannot be reused during the long time interval between the concrete casting and the completion of the curing process.
For this reason, for the construction of a building, for example a multistorey building, it is thus necessary to use a high number of said formworks, which must remain in place for periods that may even reach 28 days, that is, until the concrete curing process has been completed.
The need is also known to produce ribbed concrete floors, with a flat, approx. 5 cm thick slab and reinforced beams arranged at a distance of approx. 50-60 cm.
For this purpose, disposable panels or formworks are known, consisting of a block of foamed plastic material, typically polystyrene, having an elongated rectangular shape in plan view and a generically parallelepiped cross section with central or lateral seats to provide the housing where the reinforcing bars are placed before concrete is cast in order to obtain the reinforced ribs of the floor.
The subject of the present invention is a new type of reusable modular formwork for making ribbed reinforced concrete floors.
The main object of the present invention is to ensure the rapid laying of reusable modular elements of the portal-shaped type for making ribbed reinforced concrete floors, wherein said portal-shaped elements rest and are maintained in place on a temporary bearing structure.
Another important object of the present invention is to allow the rapid removal of said portal-shaped elements, dismantling said temporary bearing structure.
A further important object of the present invention is to make ribbed floors comprising beams with enlarged heads, using modular head elements of the portal type shaped in a particular way, with no need to use any further specific equipment.
A further important object of the present invention is to make ribbed floors with partitions, using modular partition elements of the portal type shaped in a particular way.
Another object of the present invention is to allow said portal-shaped elements to be dismantled and then reused just a few days after the concrete has been cast, in any case keeping the floor propped until the concrete curing process has been completed.
An important advantage offered by the present invention lies in that it requires fewer portal-shaped elements in the whole, since it is possible to reuse the same portal-shaped elements almost immediately, thanks to the fact that it is not necessary to leave them in place until the concrete curing process has been completed.
These and other direct and complementary objects are achieved by the new type of reusable modular formwork for making ribbed reinforced concrete floors, comprising a plurality of modular portal elements, shaped in a particular way, each one comprising in turn a horizontal upper base in contact with the concrete casting and at least two opposing lateral walls in contact with the concrete casting, with lower edges suited to rest on a temporary bearing structure.
Said portal-shaped elements also comprise head edges especially shaped with ribs and/or seats suited to be coupled and precisely aligned with adjacent modular elements.
According to the invention, said formwork may also comprise one or more modular portal-shaped elements comprising, in addition to said horizontal upper base and said two opposing lateral walls with said lower edges, also one or more head walls in contact with the concrete casting, with lower edges or lower plane parts in contact with the concrete casting, for making floors with ribbing in two orthogonal directions.
The characteristics of the invention will be highlighted in greater detail in the following description, with reference to the drawings attached as nonlimiting examples.

Figure 1 shows a three-dimensional view only of the modular portal-shaped element (Sn) open at the ends (S41, S42), with smooth lateral walls (S21, S22), while Figure 1a shows only the portal-shaped element (Sn) with ribbed (S8) lateral walls (S21', S22').
Figure 1b shows in detail part of the U-shaped male edge (S411) of the open male end (S41).
Figure 2 shows a three-dimensional view of a head portal-shaped element (St), aligned with a portal-shaped element (Sn) open at the ends (S41, S42).
Figures 3 and 4 respectively show a three-dimensional schematic view of the portal-shaped partition elements (Sp1, Sp2), with upper base (S1) comprising at least one partially lowered (S131) or completely lowered (S 132) intermediate part for carrying out partitions in the floor.
Figure 5 shows only the portal-shaped element (Sc1) with closed ends (S51, S52), rectangular in plan view, with lateral walls (S21', S22') and ribbed (S8) head walls (S71', S72').
Figure 6 shows only the portal-shaped element (Sc2) with closed ends (S51, S52), square in plan view, with upper base (S1), lateral walls (S21, S22) and non ribbed head walls (S71, S72).
Figure 7 shows only the portal-shaped head or connection element (Sb) with lateral walls (S21', S22'), upper base (S1') and ribbed (S8) head walls (S71', S72').
Figure 8 schematically shows how to use the modular head and connection element (Sb) suited to be inserted in a portal-shaped element (Sn), for example with open ends (S41, S42), in order to close one of the open ends (S41) of the element itself or to serve as connection element with a further modular element (Sn) aligned therewith, as schematically shown in Figure 8a.
Figure 9 shows, in a cross section in relation to the portal-shaped elements (Sn), the obtained formwork, resting on a temporary bearing structure, and also the concrete casting of the ribbed floor (L), comprising a series of beams (L1) with overlying flat slab (L2).

In detail, each one of said portal-shaped modular elements comprises a monolithic element, rectangular in plan view, with modular lenght, for example 60-100 cm, and overall modular width comparable to the distance between the beams (L1) of the ribbed floor, for example 60 cm, excluding the lateral supporting and overlapping parts.
The portal-shaped modular element (Sn) has in its whole a generically parallelepiped or trapezoidal shape, preferably with portal-shaped cross section, that is, with at least two preferably plane opposing lateral walls (S21, S22), for example slightly inclined, and with preferably plane horizontal upper base (S1).
Each one of said lateral walls (S21, S22) comprises a lower edge (S31, S32) suited to rest on the temporary bearing structure, wherein said lateral wall (S21)/(S22) and said lower edge (S31)/(S32) of each portal-shaped element (Sn) is suited to form, if necessary in combination with the upper surface of the elements of the bearing structure and/or with a further portal-shaped element (Sn) arranged symmetrically in relation to said element of the structure, a rib suited to house the reinforcing bars and the concrete casting of the beam (L1) of the ribbed floor.
The edges (S411, S421) of said upper base (S1) and/or of said lateral walls (S21, S22) forming the opposing open ends (S41, S42) of each portal-shaped element (Sn) are completely or partially shaped with projections and/or seats suited to be aligned and precisely coupled with other modular elements.
In greater detail, in the preferred embodiment illustrated in Figure 1b, according to the invention said edges (S411, S421) of one or both the open ends (S41, S42) are folded, completely or partially, for example in the shape of a U facing upwards, wherein the U-shaped male edge (S411) of one end, or male end (S41), has shape and size suitable for insertion in the U-shaped female edge (S421) of the opposite end, or female end (S42), of the portal-shaped modular element (Sn) aligned therewith.
In order to guide the operator so that he/she can correctly align and match the elements, according to the invention said U-shaped male edges (S5411) comprise one or more ribs (S412) on the concave part of the edge itself (Figure 1b), in such a way as to prevent the U-shaped female (S421) and male (S411) edges from overlapping and being coupled incorrectly.
As already explained, positioning side by side two of said new portal-shaped elements (Sn) means that the opposing lateral walls (S21, S22) and the lower edges (S31, S32) of the two adjacent portal-shaped elements (Sn) will define, in combination with one or more elements of the temporary bearing structure, a seat whose width and depth are such as to house the reinforcement for making the ribs or beams (L1) of the ribbed reinforced concrete floor.
Therefore, by placing side by side a plurality of rows of portal-shaped elements (Sn) it is possible to obtain a formwork for casting ribbed reinforced concrete floors, as schemtically shown in Figure 9.
The invention also provides for the use of portal-shaped elments, hereinafter called head elements (St) (Figure 2), particularly suited to form the enlarged heads of the beams of the ribbed floor, that is, heads whose width exceeds the width of the beam body, suited to ensure greater shearing strength of the beam or rib at the level of the bearing point.
Said modular head element (St) is a monolithic body substantially rectangular in plan view, whose size, in plan view, is preferably comparable to the size of said normal portal-shaped elements (Sn), that is, having modular length, for example 60-100 cm, and width comparable to the distance between the beams of the ribbed floor, for example 60 cm, excluding the supporting and overlapping parts.
Said portal-shaped head elements (St) also comprise a horizontal plane upper base (S1), at least two opposing lateral walls (S21, S22), for example slightly inclined, and at least one closed end (S51), that is, at least one head wall (S511) in contact with the concrete casting, with horizontal plane lower part or edge (S61) in contact with the concrete casting, in order to increase the thickness of the beam, and wherein said lateral walls (S21, S22) converge to form, with said plane upper base (S1), a projection that is substantially triangular, trapezoidal or generically arched in plan view, with longitudinal axis of symmetry in relation to the portal-shaped element (St) itself.
In plan view, the base of said projection coincides with one of the coupling ends, male (S41) or female (S42), while said head wall (S511) connecting said lateral walls (S21, S22) is directed towards the front edge (S611) of said lower plane part (S61) and is preferably positioned backward in relation to it.
Also said portal-shaped head element (St) has the edge (S421) of the open end (S42) folded in the shape of a U in order to be aligned with and removably fixed to a portal-shaped element (Sn) aligned behind it, as shown in Figure 2.
Positioning side by side two of said portal-shaped head elements (St), symmetrically in relation to a prop or other element of the bearing structure, means creating between them a seat that is defined at the bottom by part of said lower plane parts (S61) and by said edges (S31, S32) of the two portal-shaped head elements (St) positioned side by side, and at the sides by said opposing walls (S21, S22) that are diverging, so that the head of the beam of the ribbed floor, obtained by laying the reinforcing bars and casting the concrete in said seats, is larger than the rest of the body, which instead has width and depth corresponding to the size of the seat defined between two normal portal-shaped elements positioned side by side.
Furthermore, according to the invention, one or more portal-shaped element/s is/are used, hereinafter called partition element/s (Sp1, Sp2) (Figures 3 and 4), with upper base (S1) at least partially lowered, that is, comprising at least one partially or completely lowered intermediate part (S131, S132), interposed between two opposing end sections (S11, S12) raised substantially at the same height, that is at the height of said plane upper base (S1) in contact with the concrete casting of the adjacent portal-shaped elements (Sn, Sp1, Sp2, St).
Said portal-shaped partition elements (Sp1, Sp2) comprise, analogously to said portal-shaped elements (Sn), lateral lower edges (S31, S32) suited to rest on said temporary bearing structure and open ends (S41, S42) with edges (S411, S412) provided with seats and/or projections suited to be aligned with and removably fixed to the other portal-shaped elements.
Said portal-shaped partition elements (Sp1, Sp2), properly alternated with said portal-shaped elements (Sn), create the seats for casting the partitions of the floor, that is, of cross ribs of the slab, in order to distribute the load among the beams or ribs of the floor.
According to the invention, furthermore, one or more further portal-shaped modular elements are used, hereinafter called portal-shaped elements with closed ends (Sc1, Sc2) (Figure 5 and 6), comprising an upper base in contact with the concrete casting (S1), at least two opposing lateral walls (S21, S22) in contact with the concrete casting, and at least two head walls (S71, S72), each one provided with a lower edge or plane head part (S61, S62) in contact with the concrete casting.
Positioning said portal-shaped elements (Sc1, Sc2) beside other portal-shaped elements arranged symmetrically in relation to the elements of the temporary bearing structure means obtaining seats that are defined at the bottom by said lateral lower edges (S31, S32) and at the sides by said lateral walls (S21, S22), wherein the width and depth of said seats are such as to house the reinforcement for making the ribs of the reinforced concrete floor.
Said head walls (S71, S72), instead, substantially serve as covering or formwork bottom surfaces and, if aligned with other modular elements (Sc1,
Sc2) positioned side by side, create cross-seats defined at the bottom by said lower plane parts (S61, S62) of the two modular elements positioned side by side and at the sides by said opposing head walls (S71, S72).
In this way also the seats for casting cross-beams or partitions are obtained, thus creating a warping of ribs in two orthogonal directions.
For this purpose, the width of said lower head parts (S61, S62) exceeds the width of said lateral lower edges (S31, S32).
As shown in Figure 5, according to the invention said portal-shaped element (Sc1) with closed ends may be rectangular in plan view, with ribbed (S8) lateral walls (S21', S22') and head walls (S71', S72').
As shown in Figure 6, according to the invention said portal-shaped element with closed ends (Sc2) may be square in plan view, with non ribbed upper base (S1), lateral walls (S21, S22) and head walls (S71, S72).
According to the invention said portal-shaped element with closed ends (Sc2), rectangular or square in plan view, can have ribbed lateral walls (S21', S22') and/or head walls (S71', S72').
According to the invention, furthermore, additional modular elements, hereinafter called head and connection elements (Sb) (Figure 7), are used, which comprise an upper base (S1), at least two opposing lateral walls (S21', S22') and one or two closed head walls (S71', S72'), wherein said head and connection element (Sb) has shape and size suited to allow it to be inserted, at least partially, in longitudinal direction, in at least one of said portal-shaped elements, which can be a normal (Sn) and/or head (St) and/or partition (Sp1, Sp2) element.
Said head and connection element (Sb) may also comprise one or more lower feet (S9) suited to rest on the quick-dismantling elements that make up the temporary bearing structure.
In greater detail, said head and connection element (Sb) can be used as a closing element of an open end (S41 and/or S42) of a modular element (Sn, St, Sp1, Sp2).
For this purpose, as shown in Figure 8, said head and connection element (Sb) is at least partially inserted, longitudinally, in at least one portal-shaped element (Sn), so that the relative upper bases (S1, S1') and lateral walls (S21', S22') are correspondingly coupled. One of the head walls (S71') of the head and connection element (Sb), which is positioned on the outside, thus serves as a cover (Figure 8).
Said head and connection element (Sb) can be inserted in the portal-shaped element (Sn) to different degrees, in such a way as to increase/reduce the overall length of the formwork, according to the actual size of the ribbing to be obtained.
Said head and connection element (Sb) can thus be effectively used to connect or join two aligned portal-shaped modular elements (Sn, St, Sp1, Sp2) (Figure 8a).
In this case, said head and connection element (Sb) is partially inserted in both the aligned modular elements (Sn, St, Sp1, Sp2), so that only an intermediate portion of its upper base (S1') and of its lateral walls (S21', S22') is external.
Furthermore, it is also possible to join two aligned portal-shaped elements (Sn) with opposing edges that are both male edges (S411) or both female edges (S421), which otherwise could not be correctly coupled.
In order to guide the operator in the operations required to lay said elements (Sn, St, Sp1, Sp2, Sc1, Sc2, Sb) and in order to further stiffen the elements themselves as well as the final product, according to the invention each portal-shaped element comprises, distributed on the outer and/or inner surface of the upper base (S1') and/or of the lateral walls (S21', S22') and/or of the head walls (S71', S72'), a succession of ribs (S8), preferably transversal to the longitudinal direction of the elements themselves.
In particular, according to the invention said head and connection element (Sb) can be provided with a plurality of regularly spaced ribs (S8), which define an alternating succession of recesses (S81), wherein said recesses (S81) have shape and size suitable for the insertion of said U-shaped edges (S411, S421) of the portal-shaped elements (Sn, St, Sp1, Sp2).
In greater detail, according to the invention some of said recesses (S81) have shape and size suitable for the alternate insertion of the U-shaped male (S411) or female (S421) edge.
Therefore, said portal-shaped elements must be positioned on said temporary bearing structure in such a way as to create a plurality of continuous parallel seats, each one defined laterally between said lateral walls (S21, S22) of said portal-shaped elements and at the bottom by said edges (S31, S32) and/or plane base parts (S61, S62).
Said seats alternate with plane surfaces, in turn defined by said upper bases (S1), on which the concrete casting of the floor slab (L2) will be carried out.
After laying the reinforcing bars in said seats and casting the concrete, it is sufficient to allow the concrete to be partially cured, and in particular already after just a few days it is possible to remove said portal-shaped elements (Sn, St, Sc, Sp1, Sp2, Sb, Sc1, Sc2), leaving only the props in place, so that they support the cast ribbed floor until the curing process has been completed, for example up to 28 days.
Therefore, in the meantime, it is possible to reuse said portal-shaped elements immediately to make other floors, while in the known systems without the new elements carried out as claimed below this is not possible, since it is necessary to leave the formwork in place until the curing process has been completed.
A further important advantage offered by the present invention lies in that, after the formwork has been dismantled, the floor carried out in this way has a perfectly smooth lower surface, while this does not happen with disposable formworks which remain exposed and are subjected to weather agents that damage them and cause them to crumble, thus negatively affecting the appearance of the finished product.
According to the invention said portal-shaped elements (Sn, St, Sp1, Sp2, Sc1, Sc2, Sb) preferably have bevelled and/or rounded corners.
Therefore, with reference to the above description and the attached drawings, the following claims are expressed.

Claims

Reusable modular formwork for making floors (L), characterized in that it comprises one or more modular and monolithic portal-shaped elements (Sn, St, Sp1, Sp2, Sc1, Sc2, Sb), each comprising a horizontal upper base (S1) in contact with the concrete casting and at least two opposing lateral walls (S21, S22) in contact with the concrete casting, with lower parts or edges (S31, S32) suited to rest on at least one prop or beam or linear temporary bearing element and suited to removably support, directly or indirectly, said formwork and the relative concrete casting (L1).
Formwork according to claim 1, characterized in that the edges (S411, S421) of the open end/ends (S41, S42) of said portal-shaped element (Sn, St, Sp1, Sp2) comprise one or more ribs and/or seats suited to be coupled with aligned adjacent modular elements (Sn, St, Sp1, Sp2, Sb).
Formwork according to claims 1, 2, characterized in that said edges (S411, S421) of the opposing open ends (S41, S42) of said portal-shaped element (Sn, Sp1, Sp2) are completely or partially folded in the shape of a U (S411, S421), and wherein the edges of one of the open ends (S41), or male edges (S411), are suited to be inserted in said U-shaped edges of the opposite open end (S42), or female edges (S421) of a further aligned element (Sn, Sp1, Sp2, Sb).
Formwork according to claims 1, 2, 3, characterized in that on said U-shaped male edge (S411) there are one or more ribs (S412) in the concave part of the edge (S411) itself.
Formwork according to claims 1, 2, 3, 4, characterized in that said upper base (S1) of said portal-shaped modular element (Sp1, Sp2) comprises at least one partially (S131) or completely (S132) lowered intermediate part, interposed between two opposite end sections (S11, S12) raised substantially at the same height.
Formwork according to claims 1, 2, 3, 4, characterized in that said portal-shaped element (St), or portal-shaped head element, also comprises, in addition to said horizontal upper base (S1) in contact with the concrete casting and to said opposing lateral walls (S21, S22) in contact with the concrete casting, with lateral lower edges (S31, S32), at least one head wall (S511) connecting said lateral walls (S21, S22) and with an advanced edge or plane lower head part (S61) in contact with the concrete casting.
Formwork according to claim 6, characterized in that said lateral walls (S21, S22) of said portal-shaped head element (St) converge towards said head wall (S511) to form, together with said plane upper base (S1), a projection, substantially triangular or trapezoidal or generically arched in plan view, with longitudinal symmetry, and wherein said head wall (S511) is positioned backward with respect to the edge (S611) of said lower plane head part (S61).
Reusable modular formwork according to claim 1, characterized in that it comprises one or more modular or monolithic portal-shaped elements (Sn, St, Sp1, Sp2, Sc1, Sc2, Sb), each comprising a horizontal upper base (S1) in contact with the concrete casting and at least two opposing lateral walls (S21, S22) in contact with the concrete casting, with lower lateral edges (S31, S32) suited to rest on at least one prop or temporary bearing element, and two head walls (S71, S72) in contact with the concrete casting, with lower edge or plane head part (S61, S62).
Formwork according to claim 8, characterized in that said lower edge or plane head part (S61, S62) is wider than said lateral lower edges (S31,S32).
Formwork according to claim 8, 9, characterized in that said portal-shaped element (Sc1) is rectangular or square in plan view.
Formwork according to the preceding claims, characterized in that said upper base (S1') and/or said lateral walls (S21', S22') and/or said head walls (S71', S72') are ribbed.
Formwork according to claim 11, characterized in that the ribs (S8) of said lateral walls (S1', S22') and/or of said upper base (S1') and/or of said head walls (S71', S72') are transversal in relation to the longitudinal direction of the portal-shaped element (Sn, St, Sp1, Sp2, Sc1, Sc2).
Formwork according to claim 1, characterized in that it comprises one or more head and connection portal-shaped elements (Sb), each one comprising at least one upper base (S1'), at least two opposing lateral walls (S21', S22') and one or two head walls (S71', S72'), and having such shape and size that it can be longitudinally inserted at least partially in at least one portal-shaped element (Sn, Sp1, Sp2, St), by correspondingly coupling, at least partially, the relative upper bases (S1, S1') and lateral walls (S21', S22').
Formwork according to claims 11, 12, 13, characterized in that said head and connection portal-shaped element (Sb) comprises a plurality of regularly spaced ribs (S8), which define an alternating succession of recesses (S81) and projections, wherein said recesses (S81) have shape and size suitable for the alternate insertion of said U-shaped edge (S411) or of said U-shaped female edge (S421) of the portal-shaped elements (Sn, St, Sp1, Sp2).
Formwork according to claim 15, characterized in that said head and connection portal-shaped element (Sb) comprises one or more feet (S9) suited to rest on at least one prop (P) or supporting element (C, G).