EP1236843A2

EP1236843A2 - System, method and modular forms for the production of floors

Info

Publication number: EP1236843A2
Application number: EP01129435A
Authority: EP
Inventors: Giorgio Cristalli
Original assignee: Studio Tecnico Ing Giorgio Cristalli
Current assignee: CRISTALLI, NICOLA
Priority date: 2000-12-13
Filing date: 2001-12-10
Publication date: 2002-09-04
Also published as: ITTO20001159A0; ITTO20001159A1; IT1320747B1; EP1236843A3

Abstract

This invention describes a system and a method for the production of floors, based on the use of modular forms (1, 2), in order to form a structure that can contain a concrete cast (5); on the resulting structure there are lightening cavities and seats (D) for suitable reinforcing elements (3), the above-cited seats forming load-bearing ribs or beams, after the positioning of the above-mentioned reinforcing elements (3), the casting of the concrete (5) and its subsequent consolidation.

The invention enables to produce floors in reinforced concrete, with parallel unidirectional load-bearing ribs or lacunar elements with load-bearing crossed ribs, suited to comply with the static requirements of all floors of both civil and industrial buildings, in brick or reinforced concrete, and in particular for anti-seismic buildings.

Description

This invention relates to a system, method and modular forms for the production of floors.
The term "floor" in building generally identifies a flat structural element that covers a space and an area, transmits the loads to the structures or vertical walls around the area, through shearing stresses and flexure moments, and acts as joint between said structures or vertical walls.
Floors are traditionally made of joists or rather by a structure constituted by several prefabricated small joists, in concrete with iron reinforcements, which support special bricks called "hollow tiles" or "large hollow tiles".
The above-mentioned reinforced joists are arranged in parallel and rested on beams integral with the two walls that face the area to cover. The hollow tiles are laid in sequence between each pair of parallel joists that support them. This configuration defines a plane, whose lower surface, that delimits the area from the top forming its ceiling, can be plastered or coated with a light masking (ceiling or false ceiling). The upper surface of this plane, that can also be previously protected with an electrowelded wire mesh, is instead covered with a concrete cast and finished through the application of a suitable covering superstructure (tiles, parquet, etc.) to form the floor, that is a substantially smooth and solid resting surface able to withstand the weight of objects and/or people.
Though consolidated and reliable, this procedure is characterised by several practical problems.
A first series of problems derives from the complex operations required to prepare the hollow flat layer, formed by joist and bricks, also due to the significant weight of these components.
Other practical problems derive from the risks originating from the potential breakage of the components employed (and more specifically of the bricks), which could occur during transportation, during the preparation of the hollow flat layer or directly during handling operations within the yard. Even supply and stocking operations could be problematic due to the large overall size of these components.
As the above-described procedure is also very expensive, it would be ideal to be able to reduce costs.
There are also modular structures that enable to produce floors with a lower cavity which is useful to insulate rooms from the humidity of the underlying ground or from the gases that may be released from it. This cavity can also be used for the laying of pipes and lines of technological systems or for heating purposes.
This kind of solutions is described, for example, in EP-A-0 803 618 and EP-A-0 969 157.
The above-described solutions are based on the use of modular formworks, in plastic material, which are joined in sequence and side by side in order to define a continuous structure on which concrete can be cast.
These modular forms are configured in the shape of a spherical dome with four supports, connected to one another by means of an equivalent number of arches. Each arch has side edges that are designed to allow them to be joined with the edges of the adjacent modular forms in order to form a continuous structure.
After the installation of an ordinary electrowelded wire mesh or iron rods on the extrados of the spherical crowns, the structure is covered with a concrete cast, which subsequently acquires the shape of a series of domes resting on parabolic arches and ending in correspondence of the contour on four pillars.
It is useful to notice that the loading bearing function of the above-described systems, that is the support of the floor on the underlying ground, is carried out by the above-described pillars formed by the concrete. The installation of a wire mesh or of a set of iron rods only aims at reinforcing the upper section of the concrete casting, which is the part that constitutes the actual floor.
Viewed from this point of view, the systems described above, which are specifically suited for floors resting on the underlying surface by means of pillars, are not suitable for joisted floors because of the fact that they require specific load-bearing reinforcements to transmit the load of the floor to the structures or vertical walls and meet static requirements.
In English, the term "floor" is indifferently used to designate both a surface to be supported by an underlying structure, that could also be the ground, and a structure able to cover a space supporting loads to be discharged to perimetric beams or walls. Hereinafter the term "floor" will be used only with the second meaning, unless differently specified.
The invention aims at solving the above described problems that occur when roofs constructed with hollow tiles and joists or similar techniques are adopted.
At a general level, the first scope of the invention is to describe a system, a method and modular forms suited to enable the preparation of ribbed floors in a simple, affordable, easy and quick manner.
The second scope of the invention is to describe a system, a method and modular forms for the definition of ribbed floors, that can effectively reduce the risk deriving from the breaking of components and facilitate their stocking.
The third scope of the invention is to define a system, a method and modular forms suited to produce lacunar ceilings in several aesthetic variants, also with crossed reinforcements.
The fourth scope of the invention is to define a system and a method for the preparation of ribbed floors based on reusable modular forms.
These scopes and those that will be described in the following sections will be attained, as indicated in this invention, using a system, a method and modular formworks for casting concrete for the construction of ribbed floors having the characteristics indicated in the enclosed claims that are integral part of this description. Said formworks according with the invention will be hereinafter simply called "forms" or "modular forms".
Other scopes, characteristics and advantages referred to in this invention will become apparent from the following detailed description considered in connection with the accompanying drawings, which are to be regarded as an illustration only and not as a definition of the limits of the invention; where:

Fig. 1 shows a plan and a side view of a modular form of a first kind, used to produce floors in accordance with the first suggested solution described in this invention;
Fig. 2 shows a plan and side view of a modular form of a second kind, used to produce floors in accordance with the first suggested solution described in this invention;
Fig. 3 shows a set of modular forms of the first kind, as per Fig. 1, and of the second kind, as per Fig. 2, assembled to one another;
Fig. 4 schematically shows an example of floor produced in accordance with the first suggested solution described in this invention;
Fig. 5 shows a plan and a side view of a modular form, used to produce floors in accordance with the second suggested solution described in this invention;
Fig. 6 shows a set of modular forms according to Fig. 5 and assembled to one another;
Fig. 7 schematically shows a type of floor produced in accordance with the second suggested solution described in this invention;
Fig. 8 shows a plan of a modular form used to produce floors in accordance to a third suggested solution described in this invention;
Fig. 9 shows, from different prospective views, a component that can be combined with the modular form shown in Fig. 8, for floors produced in accordance with the third suggested solution described in this invention;
Fig. 10 shows a plan of a modular form produced in accordance with the requirements described in Fig. 8 and equipped with four of the components illustrated in Fig. 9;
Fig. 11 shows a section of the modular form illustrated in Fig. 10, along axis A-A of this figure;
Fig. 12 shows a set of modular forms assembled to one another, in accordance with Fig. 10;
Fig. 13 schematically shows an example of floor produced in accordance with the third suggested solution described in this invention.
Fig. 14 shows a set of modular forms assembled to one another used to produce floors in accordance with a fourth suggested solution described in this invention.
Fig. 15 shows a front view partially sectioned of a modular form according to figure 14.
Fig. 16 shows the possible shape of a locking item used with whichever modular form according to the invention.

Part 1 of Fig. 1 generically represents a form of the first kind, produced in accordance with the requirements described in this invention. Form 1 can satisfactorily be produced in pure or recycled plastic.
Form 1 substantially represents a section in the shape of an inverted U, defined by a slightly convex upper wall 1A and by two side walls 1B that are slightly inclined outwards. The lower end of each of the side walls 1B forms a substantially flat edge 1D that is used for resting and connection purposes.
1E identifies an appendix that stretches continuously along one of the longitudinal edges of walls 1A and 1B of form 1.
It is evident that form 1 substantially has a quadrangular shape suitable for the definition of a central longitudinal cavity.
Fig. 2 shows a form of the second type described in the invention, generally referred to as 2 or form 2. As indicated in the definition above, this form is constituted by a slightly convex upper wall 2A, by two side walls 2B, slightly inclined outwards, and by a bottom wall 2C, again slightly inclined outwards. The lower end of each of the side walls 2B and 2C define edge 2D, used for resting and connection purposes, which is substantially flat and similar to edge 1D of Fig. 1.
Even in this case, form 2 substantially has a quadrangular base suitable for the definition of a central cavity which, unlike that of form 2, is not open on both sides but closed on one side by means of wall 2C.
Fig. 3 shows the principle used to assemble modular forms 1 and 2.
Forms are substantially assembled in sequence, in longitudinal direction through the insertion of the appendix 1E of form 1 into the central cavity of form 2. The assembly then implies inserting into the cavity of the above-mentioned form 1 the appendix 1E of the next form 1, and so on. The last form 1 of the series is then coupled to form 2, equipped with a suitable appendix, which is similar to appendix 1E and suited to be inserted in the central cavity of the last form 1 installed. It is evident that the sequential assembly of the central cavities of forms 1-2 enables to create a vault.
As apparent in Fig. 3, forms 1-2 are then assembled side by side so that edges 1D and 2D of forms 1 and 2 are coupled with the edges, shaped for this purpose, of the equivalent adjacent forms. For this purpose, the above-mentioned edges can be equipped with suitable reciprocal coupling devices of known design.
This procedure enables to define several parallel vaults, illustrated under letter C of Fig. 3, spaced by seats, illustrated under letter D, whose bases are formed by the coupled edges 1D and 2D of the adjacent forms 1 or 2.
Fig. 4 shows an example of floor based on the use of forms 1 and 2. To produce the floor described in the invention, it is first necessary to install a traditional scaffolding of wood or equivalent material to form the structure that will act as temporary resting surface for forms 1-2. This resting surface will be placed at the same height of the desired floor lower surface. Furthermore, the opposed walls of the space will be equipped, at the same height, with resting beams, which are not shown in the figure because they are of traditional design, whose function will be described in the paragraphs that follow.
After its installation, the resting surface will constitute the base for the forms assembled in accordance with the principle described in Fig. 3. The number of the assembled forms 1-2 should obviously be suitable to create a structure with a length and width equivalent to that of the floor to be produced.
The assembly of modular forms 1-2, in accordance with the layout illustrated in Fig. 3, and their specific geometry enable to create a structure that can contain the concrete casts designed to form the floor, which will also be equipped with parallel and unidirectional load-bearing ribs, formed by the concrete that fills seats D and covers the related reinforcing elements.
The interior of seats D is designed to hold the bars or iron rods described under number 3 of Fig. 4, which should be suitable to tolerate all the stresses indicated in project specifications. The ends of these bars 3 will rest on the load-bearing beams, previously placed on the opposed walls of the space where the floor has to be laid and connected to said load-bearing beams according with the current praxis and rules. It is useful to notice that in the configuration referred to in the invention, the bars 3 do not rest on the upper surfaces of the edges 1D and 2D, but are separated by means of shims of traditional design.
It is evident that the load-bearing ribs that will be formed by means of seats D have the same depth of the side walls 1B and 2B facing them. The reinforcing elements, constituted by bars or metal iron rods 3 are positioned in the lower section of this cavity according to usual praxis and rules.
A traditional electrowelded wire mesh, illustrated under number 4 of Fig. 4, and possible iron rods for the absorption of negative moments, will be placed on the extrados, above the assembled modular forms 1-2.
The resulting structure, with an appropriately delimited perimeter (constituted, for example by the same vertical walls of the area where the floor will be laid), is then used as a base for the concrete cast. The casting is carried out using high resistance concrete, dosed in accordance with project specifications as schematically indicated under number 5 of Fig. 4. The amount of concrete cast should be suitable to "cover" all the forms installed or rather to saturate all the seats D and to guarantee the presence of a specific amount of concrete even above the upper walls 1A and 10A of the forms and to also cover mesh 4.
After allowing the concrete 5 to appropriately cure and solidify, it is necessary to remove the lower supporting hardware or structure and recover the forms 1-2 so that they can be used to produce other floors.
In order to allow the formation of the type of floor described above, with unidirectional parallel load-bearing ribs, which involves filling seats D with the related reinforcing elements 3, forms 1-2 must have a quadrangular or preferably a square or rectangular basis, with dimensions varying according to static requirements. For example, the standard size of the forms described could be such to have a distance between the centres of the load-bearing ribs of 50 - 60 cm,, and heights of 20, 24, 28 or 30 cm. The length of each form can vary from a minimum size, that could be similar to the distance between said centres, to a maximum that may be limited only by the architectural requirements to be met during assembly.
As explained above, forms 1-2 are assembled in sequence on-site in order to create the lightening cavities of the floor in reinforced concrete, constituted by vaults C, and assembled side by side in order to form seats D. After they have been reinforced with the iron rods 3 and filled with concrete, the seats D become ribs or beams suited to support the floor with light reinforcement (not pre-stretched iron rods), so that a ribbed reinforced concrete floor is obtained.
As explained above, the configuration illustrated in Figures 1-4 also foresees a specific head form 2 that closes three sides of the lightening vaults C, which is used to close the concrete cast 5 next to the ends of the iron rods 3 of the above-described load-supporting beams.
Parameters for floors with parallel ribs based on the configuration of Figures 1-4, will be calculated using the traditional systems employed in construction theory and techniques. As the floor described in the invention is practically entirely constituted by reinforced concrete, all the surfaces of each section shall be regarded as completely reagent.
Fig. 5 shows a second typology of forms, in accordance with this invention, that enables to produce floors with crossed load-bearing lacunar ribs.
To produce this type of floors, it is not necessary to use two different types of forms as in the configuration shown in Figures 1-4, but a single form 10 that enables to achieve any kind of floor surface.
As the configuration in Fig. 5 shows, the geometry of form 10 resembles that of a spherical dome with a quadrangular or more specifically a square basis. It is useful to notice that, for special applications, the geometry could also resemble that of a cylindrical dome with rectangular basis.
Fig. 5 also shows that form 10 is constituted by a slightly convex upper wall 10A and by four side walls 10B that are slightly inclined outwards. The lower end of each of the side walls 10B defines a substantially flat resting and connection edge 10D. When coupled with the edges of the adjacent forms 10, the edges 10D constitute the area that forms the base for the ribs that support the floor.
The standard dimension of the forms 10, measured along the external perimeter, can be, for example, equivalent to 50 x 50 cm or to 60 x 60 cm. Standard heights can instead be equivalent to 20, 24, 28 or 30 cm. These heights will always be selected according to the laws in force, the span of the floors to be produced and obviously in function of possible special requirements. Basic and height dimensions may be freely selected by project engineers.
Fig. 6 shows the assembly principle for modular forms 10.
Even in this case, forms 10 are assembled in sequence and next to one another so that the edges 10D of a form can be coupled with the edges 10D of the adjacent forms, that are appropriately shaped according to known shapes.
Even in this case, there are several seats, illustrated under letter D in Fig. 6 that are crossed in two orthogonal directions as compared to the previous configuration.
Fig. 7 shows an example of a floor with forms 10, which is similar to the one described in Figures 1-4 above.
To produce a floor according with the invention requirements, it is necessary to set-up a scaffolding or structure suitable to hold the forms 10, which are then assembled in accordance with the principle described in Fig. 6. In this case, it will be necessary to previously prepare four resting beams running along the perimeter, not shown in the figure, at the height where the floor has to be laid.
Even the assembly of modular forms 10 in accordance with Fig. 6 and their specific geometry enables to create a structure suited to contain the concrete casts destined to form the floor, which will have a double set of crossed load-bearing ribs, running in two directions. These crossed load-bearing ribs will be formed by the concrete that fills seats D in which the related reinforcing elements have been laid.
To allow this operation to be performed, it is necessary to insert bars or iron rods 3, suited to tolerate project stresses, in the interior of seats D. The ends of these bars will rest on the above-described perimeter load-bearing beams, formed on the walls within which the floor must will be laid.
A traditional electrowelded wire mesh 4, and possible rods for the absorption of negative moments, will be placed on the extrados, above the assembled modular forms 10.
The resulting structure is then used as a base for an ordinary concrete cast. The casting is carried out using high resistance concrete, dosed in accordance with project specifications as schematically indicated under number 5 of Fig. 7. Even in this case, the amount of concrete cast should be suitable to saturate all the seats D and guarantee the presence of a specific amount of concrete even above the upper walls 1A and 10A of the forms and to submerge the mesh wires 4.
After allowing the concrete to appropriately cure and solidify, it is necessary to remove the lower supporting scaffolding or structure and recover the forms 10 so that they can be used to produce other floors.
Even in this case, forms 10 are assembled in sequence and side by side in order to create the lightening cavities of the floor (constituted by the cavity inside walls 10A-10B of forms 10) and to define the longitudinal load-bearing crossed ribs formed by the concrete that fills seats D and the related reinforcing elements.
This results in the alternation of the solid and hollow areas that define the crossed ribs, which are separated by the single lightening cavities of the base in reinforced concrete, constituted by the cavity inside form 10 that actually forms the lacunar elements.
Even in this case, after the reinforcement with iron rods 3 and the concrete filling, seats D form actual load-bearing ribs or beams with light reinforcement.
The description above clearly shows that each form 10 can be used to form a lacunar element. The installation of more lacunar elements or forms 10 enables to create a double set of load-bearing ribs in both directions.
It is useful to notice that the lacunar floor produced in accordance with this invention doesn't involve additional costs.
Lacunar floors, with double set of load-bearing ribs will be delimited, as explained above, on all four sides by beams or resting surfaces suitable to tolerate the loads that are characterised by a non linear trend and by a generally variable trend with triangular configuration. Considering that this kind of floor is not characterised by a preferential load-bearing direction and that it is almost entirely made of concrete, the theoretical hypothesis of infinitely rigid orientation formulated in anti-seismic calculations is much more real and alike to the actual status as compared to traditional techniques.
It is useful to notice that crossed ribs are particularly useful for anti-seismic structures, but complex to form with the traditional floor building components and techniques known so far. The invention demonstrates the opposite by showing that crossed ribs are easy to achieve with the forms and methods described in the invention.
The considerations given above clearly show that the use of the forms described in the invention enable to produce, in an innovative manner, floors in reinforced concrete, with parallel unidirectional load-bearing ribs (Figures 1-4) or lacunar elements with load-bearing ribs crossed in the two orthogonal directions (Figures 5-7), suited to comply with the static requirements of all floors to be produced on-site of both civil and industrial buildings, in brick or reinforced concrete, and in particular for anti-seismic buildings.
In practical terms, the techniques described in the invention enable to produce floors in concrete that can be lightened, shaped and equipped with load-bearing reinforced ribs, running along one or both directions of the plane through the use of the forms described.
After the removal of the reinforcement, the lower surface of this floor can be left open (in this case, special care should be adopted when preparing the concrete) or covered with all kinds of false ceilings.
The upper surface of the floor, formed by the layer of concrete that surmounts the extrados of the forms, can accommodate a screed with the minimum thickness (4 cm) required by laws and the desired coating.
As explained above, after appropriately selecting the forms more suitable to comply with project specifications, the only essential materials required to produce the floors described in the invention are the reinforced elements 3 situated inside the seats D, the electrowelded metal wires 4 situated on the extrados and the dosed concrete cast 5, with the resistance indicated in project specifications, required to "submerge" all the forms and the wire 4.
Regardless of the type of form, the plastic used and the selected form, each form will be unbreakable, stackable and suited to guarantee, at all times, the complete treadability during the assembly phase and the absolute resistance to concrete casts, including those characterised by a high fluidity. For this reason, edges 1D, 2D and 10D, described above, are preferably equipped with reciprocal coupling devices conceived according to whichever suitable already known design.
The forms described in the invention can be satisfactorily made of pure or recycled plastic. The preferred material is generally a polypropylene of a kind resistant to the impacts and the low temperatures that may occur within the building yard. The forms described in the invention can be satisfactory produced by thermal vacuum forming or injection moulding. The moulding draft angle of the item should allow a compact stacking to facilitate the storage of the forms and their removal from the concrete. Shapes, thickness and, if necessary, possible ribs should allow complete treadability.
It is useful to notice that the lightness of the forms described in this invention facilitates and accelerates on-site assembly. The stackability of the forms facilitates storage and transportation on the scaffolding.
The possibility of stocking of forms described in this invention enables technicians to start laying a floor at any time, without having to order the floor from third parties and waiting for the latter to prepare and deliver the required materials to the yard.
The essential characteristic of the invention lies also in the possibility of re-using the forms to produce several floors, which enables to significantly reduce costs as compared to traditional techniques.
The description given above clearly shows the characteristics of this invention, that are described in further detail in the enclosed claims. The description given above also shows that the method and modular forms can be used, by experts of the fields, in several variants without necessarily departing from the innovation of the invention. It is also clear that in practical terms the components and materials described above can be replaced by technically equivalent elements.
For example, the shape of forms 10 can differ from those described above to allow the management of a whole series of aesthetic variants and the production of vaults or lacunar elements with various characteristics and shapes of the upper and side walls 10A and 10B.
The specific architectural configuration of the two types of floors, respectively illustrated in Figures 1-4 and 5-7, enables these floors to be used in an open configuration, after the removal of the forms, or to be prepared for more complex technological applications. An example of advanced application is illustrated in Figures 8-13.
In particular, item number 20 of Fig. 8 shows a form that is very similar to that illustrated in Figures 5-7, and thence constituted by an upper wall 20A, by four side walls 20B and by adequate resting and coupling edges 20D.
In accordance with the illustrated variant, one or more side walls 20B may have an opening, indicated with number 20E, for the insertion of a special hollow tubular element. In the example illustrated of Fig. 9, this tubular element, referred to with number 30, substantially has a truncated conical shape. They also may be made using vacuum forming or injection moulding of plastic materials.
Figures 10 and 11 show that the tubular elements 30 are suited to be threaded through the openings 20E of the forms 20, in order to allow them to project from the forms themselves.
The assembly of forms 20 is substantially carried out with the same procedures described for Fig. 6. However, in this case, as shown in Fig. 12, the tubular elements 30 that project from the two walls facing the adjacent forms 20 will be reciprocally coupled. For this purpose, the external ends of elements 30 are equipped with special reciprocal coupling devices constituted, as shown in Fig. 9, by a series of alternated relieves 30A and seats 30B.
It is evident that to produce a floor with the forms 20, it is necessary to use a procedure similar to that described above with reference to Fig. 7.
Then on the scaffolding the forms 20 will rest, assembled in accordance with the principle described in Fig. 12, equipped with the related tubular elements 30 not yet coupled to one another.
This scaffolding should be configured in order to provide openings for the insertion from below of the tubular elements 30 into the central cavity of the forms 20 and consequently also into openings 20E. For example, to form these opening it is possible to use a structure constituted by non joined panels or by panels already equipped with openings, etc..
The interior of seats D is suited to allow the insertion of bars or iron rods 3, whose ends are rested as known on appropriate beams running along the perimeter.
At this point, the tubular elements 30 are coupled to one another and to the extrados, above the assembled modular forms 20, then the electrowelded wire mesh 4 and possible iron rods for the absorption of the moments negative stresses indicated in the project are placed.
The resulting structure is then covered by a high resistance concrete cast, dosed according to project requirements, as explained above and schematically illustrated under number 5 of Fig. 13.
After the concrete has been cured, it is necessary to remove the lower scaffolding or resting structure and recover the forms 20 and the tubular elements 30 so that they can be used to produce other floors.
It is evident that in the variant described, the forms 20 with special tubular elements 30, enable to define passages inside the load-bearing beams formed by the concrete that fills the seats D, to establish a direct communication with all the hollow volumes of the floor.
By doing so, it is possible to use the floor as equipped support in which channels, tubes, cables and several technological lines can be inserted. An ordinary false ceiling in plasterboard or in other more sophisticated materials may be used to hide the intrados of the floor together with all the systems it contains.
It is clear that the variant described in Figures 8-13 can be directly applied also to floors with parallel unidirectional load-bearing ribs of the type described in Figures 1-4. In this case, the openings for the insertion of the tubular elements 30 will be defined in the walls 1B of the forms and in the walls 2B and 2C of forms 2.
It is evident that the coupling devices used for the tubular elements 30 may differ from those shown in 30A and 30B. These temporary coupling devices will generally be suited to guarantee the linking between the elements 30 during the casting phase and the disconnection of these elements after the consolidation of the concrete.
Instead of using pairs of tubular elements 30, it is also possible to use disposable elements that can be easily broken. Such elements should preferably be in expanded polystyrene. These elements can inserted in sequence after the installation of the reinforcing iron rods, to form a bridge between each pair of openings 20E facing two adjacent forms 20, to prevent the cast concrete from leaking from the openings 20E. Despite the projection of the ends of these elements in the interior of the forms 20, these elements do not prevent extraction. Elements are flexible and can be hollow or easy to break in order to allow the subsequent insertion of pipes and other lines.
Figures 14 and 15 show a further variant of the invention to easily obtain passages between the cavity created by the forms. Four identical forms 21 are shown, having an upper wall 21A and four side walls each of which may consist in an upper portion 21B and a lower portion 21C; the lower portions 21C are slightly overhanging with regard to the upper portion 21B so that, substantially in the middle of the height and preferably in the middle of the width, each lower portion can have a seat 21E, open on top, whose back surface 21F is made up by the extension down of the upper portion 21B of the corresponding side wall and whose lateral surface 21G extends from the lower to the upper portions respectively 21C and 21B. Both the upper and lower portions 21B and 21C of said side walls, as the above described forms 1, 2, 10 and 20, have the draft inclination necessary to withdraw the forms 21 from the mould and the concrete and to stack them. In the seats 21E the extremities of tubular items 31 can be placed, pushing it down, so to form a bridge among the facing seats 21E of each two adjacent forms 21. The seats 21E are so shaped as to receive, with a slight interference, the extremities of the tubular items 31 that, then, remain locked in their position.
The tubular items 31 can be simply pieces of economic plastic tubes of the type used to drain rain water, since they are destined to be submersed and lost in the concrete; accordingly, in the figures 14 and 15, the seats 21E have been shown as having a "U" shape. Of course, in this case, the stacking of the forms 21 cannot be completely compact, due to the interference between the vertical sides 21G of the "U" shaped seats 21E of two contiguous superposed forms.
But there can be many other ways to quickly lock in their position the tubular items 31; a second one can be simply cutting them in a length that gives a slight interference between the their extremities and the inclined back surfaces 21F while a third one could simply be forcing a wedge of yielding material, such as expanded polystyrene o cardboard, within each back surfaces 21F and the corresponding tubular items 31 extremity. Of course, one or more of these possibilities could be used together.
In the described cases in which the locking of the tubular items 31 is obtained forcing them between the surfaces 21F, directly or by means of a yielding material, the seats 21E can have the shape of saddle without vertical sides 21G so allowing a compact stacking of the forms 21 as for the forms 1, 2, 10 and 20.
The form 21 is utilised substantially as described for the preceding forms; trials have shown that the concrete is not so fluid to flow within the cavities of the tubular items 31 that then, remain empty, safe possible crumbs at their extremities, neither said tubular items 31 are pushed away from their position by the fluid concrete pressure. At the end of the operation, after that the concrete has been cured and the forms 21 removed, the passages between adjacent cavities are obtained simply removing possible crumbs.
The advantage of forms as the 21 are many. A first one is the rapidity with which the tubular items 31 can be placed at the correct position. A second one is the rapidity with which the passages between the cavities are obtained since it is not necessary to remove tubular elements such as 30 or disposable expanded polystyrene elements. A third one is the possibility of utilising the same forms both for obtaining roofs with lacunar ceiling at the intrados, since said forms have no holes, and for roofs containing ducts and hidden at the intrados by false ceiling; in fact the lower portions 21C of the side walls and the corresponding seats 21E, although necessary for technical reasons, may be shaped so to have an aesthetic validity.
It is obvious that all the connection means and elements explained to obtain passages between adjacent cavities (i. e. the elements 20E and 30 or the disposable expanded polystyrene elements so as the elements 21E and 31), also if described with reference to the forms 20 and 21, can be used indifferently with the forms 1 and 2.
The upper wall 21A of the forms 21 show also that it could be provided with steps 21H and ribs 21I. While the steps 21H have essentially an aesthetic function, the ribs 21I have mostly a stiffening function, to improve the treadability; of course, both steps 21H and ribs 21I can be used with other forms according to the invention. As an example, a form made of polypropylene, 60 x 60 cm wide, 6 mm thick and having ribs 21I 15 mm height has proved to be enough treadable.
Figure 14 shows, finally, some locking items 40 placed at the junctions of four vertexes of four adjacent forms 21; not all the locking items 40 are shown in the figure neither it is necessary to place them at all the junctions. Said locking items 40, that can be used with whichever form according to the invention, can be pinned to the wooden bearing scaffolding by means of a nail and can be useful to maintain in their position said forms while pouring the concrete; the locking items 40 are later removed and recovered after having extracted the forms by the cured concrete. Since, in case of a lacunar or vault ceiling, the impression of the locking items 40 on the ceiling remain visible, it can be useful to shape them in a regular form, such as a flat disc, as shown in figure 14, or a rosette, as shown in figure 16.
Further variations of the invention are now listed.
In case it is preferred not to provide stiffening ribs 21I or proper thickness of the forms to assure their treadability, it is possible to simply place pieces of a tube of the proper eight between the scaffolding and the upper walls of the forms, in the guise of a strut that will be removed and recovered after having dismounted the scaffolding.
It can be noted that the perimeter of the forms according to the invention is not necessarily rectangular or square; for instant, the perimeter could be a regular quadrilateral with no rectangular corners or a triangle. In fact, the only condition to be assured, according to the invention, is that continuous and rectilinear seats D, destined to contain the reinforcing elements 3, must be created between almost two perimetral load-bearing beams while the side walls 1B, 2B, 10B, 20B, 21B and 21C may have whichever shape provided that they assure the technical requirements requested by the invention.
At last, avoiding to cast concrete on one or more of the upper walls 1A, 2A; 10A; 20A; 21A, all the forms according to the invention may be used to build up horizontal supporting structures consisting in a grid of crossed reinforced concrete ribs or beams with openings within the ribs to be left free or later covered with other materials so that, for instance, ceiling windows or lanterns can be obtained; according to this version, possible iron rods to absorb moments negative stresses will be positioned on the upper part of the seats D instead than over the upper walls 1A, 2A, 10A, 20A or 21A.
Of course whichever operation necessary to complete the reinforced concrete structures realised according to the present invention may proceed according to the traditional praxis.

Claims

Modular system for the construction of horizontal supporting structures comprising a grid of parallel or crossed reinforced concrete ribs or beams or for the construction of reinforced concrete ribbed floors, to be supported by resting beams, characterised in that it utilises modular concrete formworks or forms (1, 2; 10; 20; 21)
where said forms (1, 2; 10; 20; 21) have

an upper wall (1A, 2A; 10A; 20A; 21A),

at least two side walls (1B; 2B - 2C; 10B; 20B; 21B - 21C), defining an inner cavity (C) open at least downward

supporting elements or edges (1D; 2D; 10D; 20D; 21D) apt to lay on an underlying plane or scaffolding,

and an over-all shape apt to allow the extraction of said forms (1, 2; 10; 20; 21) from the reinforced concrete, once cured and solidified

and where said forms (1, 2; 10; 20; 21) are apt

to be arranged in sequence and side to side, in order to form a substantially continuous surface suitable to receive and contain a concrete cast (5)

and to define, between side walls (1B; 2B - 2C; 10B; 20B; 21B - 21C) and edges (1D; 2D; 10D; 20D; 21D) of adjacent forms (1, 2; 10; 20; 21), seats (D)

extending substantially rectilinear from one to another resting beam

and apt to almost receive

a reinforcing elements (3), in particular bars or iron rods, extending in length between at least two opposed walls of the area,

b possible iron rods for the absorption of negative moment

c and a concrete (5) casting

so that, once the concrete has cured and solidified and the scaffolding has been removed, a supporting structure consisting in reinforced concrete beams is obtained.
System, in accordance with claim 1, characterised in that said upper wall (1A, 2A; 10A; 20A; 21A) are apt to receive,

a traditional electrowelded wire mesh (4),

and a further concrete cast (5) so that, once the concrete has cured and solidified and the scaffolding has been removed, a supporting roof in reinforced concrete having a continuous upper surface and consisting in a ribbed structure where the ribs are separated by lightening cavities (C) opened downwards is obtained.
System, in accordance with claims 1 or 2, characterised in that said forms (1, 2; 10; 20; 21) can be removed without damages for their further use after the consolidation of the concrete (5) and the removal of the underlying scaffolding..
System, in accordance with at least one of the previous claims characterised in that each pair of edges (1D; 2D; 10D; 20D; 21D) of each two adjacent forms (1, 2; 10; 20; 21), co-operating each other in forming a concrete tight joint, are equipped with reciprocal coupling devices conceived according to whichever suitable already known design able to avoid concrete (5) pouring.
System, in accordance with at least one of the previous claims, characterised in that said above-described seats (D) are formed by said supporting elements or edges (1D; 2D; 10D; 20D; 21D) and the corresponding side walls (1B; 2B - 2C; 10B; 20B; 21B - 21C).
System, in accordance with at least one of the previous claims, characterised in that the depth of said seats (D) varies according to the height of the side walls (1B; 2B - 2C; 10B; 20B; 21B - 21C).
System, in accordance with at least one of the previous claims, characterised in that said reinforcing elements (3) are placed in the lower part of seats (D) according to known methods and rules.
System, in accordance with at least one of the previous claims characterised in that said modular forms (1, 2; 10; 20; 21) are configured to define, after their arrangement, seats (D) that can run parallel in a single direction or be crossed in two or more orthogonal directions.
System, in accordance with claim 8, characterised in that it employs modular forms of a first type (1), equipped with two opposed side walls only (1B).
System, in accordance with claim 9, characterised in that it further employs modular forms of a second type (2), which include an upper wall (2A), two opposed side walls (2B) and a bottom wall (2C) connecting the two side walls (2B) each other.
System, in accordance with claims 9 or 10, characterised in that almost said modular forms of the first type (1) include at least an appendix (1E) that extends, without interruptions, to one of the longitudinal edges respectively of the upper (1A) and side walls (1B), being said appendix (1E) designed to co-operate with another modular form (1) or (2).
System, in accordance with whichever claim from 9 to 11, characterised in that all said spaces or cavities of said modular forms of the first type (1), are assembled in sequence to define the continuous vault of the floor.
System, in accordance with claim 8, characterised in that it employs modular forms of a third type (10; 20, 21), which include an upper wall (10A; 20A; 21A) and four side walls (10B; 20B; 21B - 21C).
System, in accordance with the previous claim, characterised in that said spaces or cavities of said modular forms of the third type (10;20) form lacunar elements of the floor.
System, in accordance with at least one of the previous claims, characterised by the use of connection means and elements (20E, 30; 21E, 31) that enable to define, within the ribs or beams that support the floor, passages for a direct communication between the lightening cavities (C) of the floor, enabling said passages the insertion of raceways, pipes, cables, etc.
System, in accordance with claim 15, characterised in that said connection elements (20E, 30; 21E, 31) comprise

cavities (20E), each one situated on one or more side walls (1B; 2B - 2C; 10B; 20B),

and connection elements (30), with a truncated conical shape, suited to guarantee at least the partial exit from said cavities.
System, in accordance with the previous claim, characterised in that the external side of these connection elements (30) has reciprocal coupling elements (30A, 30B) that enable to temporarily join the connection elements (30) projecting from the two side walls (20B) facing the two adjacent modular forms (20) and then to remove and further use said connection elements (30) after the scaffolding removal.
System, in accordance with claim 15, characterised in that the above-described connection elements (20E, 30) comprise

cavities (20E), each one situated on one or more side walls (1B; 2B - 2C; 10B; 20B),

and disposable elements that can be easily broken, preferably constituted by polystyrene foam cylinders, hollow in particular.
System, in accordance with claim 15, characterised in that said connection elements (20E, 30; 21E, 31) comprise

seats (21E), open on top, each one situated in one or more side walls (21B - 21C) of a form (21) whose side walls consist in an upper portion (21B) and in a lower portion (21C), said lower portions (21C) being slightly overhanging with regard to said upper portion (21B)

said seats (21E) being placed substantially in the middle of the height and preferably in the middle of the width of said side walls (21B - 21C)

and being defined, said seats (21E), by a back surface (21F) made up by the extension down of the upper portions (21B) of the side walls (21B - 21C) and by a lateral surface (21G) extending from the lower to the upper portions (21C, 21B),

tubular items (31) apt, pushing them down onto said seats (21E), to form a bridge among the facing side walls (21B - 21C) of each two adjacent forms (21),

having, said tubular items (31), their extremities apt to be placed within said seats (21E) and a length apt to put the same extremities substantially in contact with the back surface (21F) of said facing seats (21E)
System, in accordance with the previous claim, characterised in that said tubular items (31) have such a length as to be locked, with a slight interference, between said back surfaces (21F) of two facing seats (21E).
System, in accordance with the previous claims 19 or 20, characterised in that a wedge of yielding material, such as expanded polystyrene o cardboard, can be forced within each back surfaces (21F) and the corresponding tubular items (31) extremity.
System, in accordance with whichever previous claim from 19 to 21, characterised in that said seats (21E) are so shaped as to lock, with a slight interference, the extremities of said tubular items (31).
System, in accordance with the previous claim, characterised in that said seats (21E) have the lateral surface (21G) "U" shaped while the tubular items (31) are pieces of a tube.
System, in accordance with whichever previous claim, characterised in that the forms (21) equipped with said seats (21E) are stackable for storage and/or transportation purposes.
System, in accordance with whichever previous claim from 1 to 21, characterised in that the forms (21) equipped with said seats (21E) are stackable in a compact stack for storage and/or transportation purposes.
System, in accordance with at least one of the previous claims, characterised in that said above-described modular forms (1, 2; 10; 20; 21) may have a triangular or a regular quadrilateral base and, more specifically, a rectangular or square base.
System, in accordance with at least one of the previous claims, characterised in that the above-described modular forms (1, 2; 10; 20; 21) are made in pure or recycled plastic like polypropylene, preferably resistant to shocks and low temperatures, produced in particular by means of vacuum forming or injection moulding.
System, in accordance with at least one of the previous claims, characterised in that the above-described modular forms (1, 2; 10; 20; 21) are treadable.
System, in accordance with at least one of the previous claims, characterised in that the treadability of the above-described modular forms (1, 2; 10; 20; 21) can be improved providing them with stiffening ribs (21I).
System, in accordance with at least one of the previous claims, characterised in that the treadability of the above-described modular forms (1, 2; 10; 20; 21) can be assured by struts apt to be inserted between the scaffolding and said forms (1, 2; 10; 20; 21) and to be removed and recovered after having dismounted said scaffolding.
System, in accordance with at least one of the previous claims, characterised in that the above-described modular forms (1, 2; 10; 20; 21) can be blocked in their position during the concrete pouring by means of locking items (40) fixed on the underlying scaffolding by means of a nail and then recovered after having dismounted said scaffolding.
System, in accordance with the previous claims, characterised in that the impression left on the cured concrete by said locking items (40) may be used with an aesthetic function utilising locking items (40) in form of discs or other shapes.
System, in accordance with at least one of the previous claims, characterised in that the technical means present in the above-described modular forms (1, 2; 10; 20; 21) can be drawn so to have also aesthetic functions.
Modular forms (1, 2; 10; 20; 21) for the formation of floors including

an upper wall (1A, 2A; 10A; 20A; 21A),

at least two side walls (1B; 2B - 2C; 10B; 20B; 21B - 21C), defining an inner cavity (C) open at least downward

supporting elements or edges (1D; 2D; 10D; 20D; 21D) apt to lay on an underlying plane or scaffolding,

being all said means (1A, 2A; 10A; 20A; 21A; 1B; 2B - 2C; 10B; 20B; 21B - 21C; 1D; 2D; 10D; 20D; 21D) shaped in whichever form able to allow the feasibility of the system in accordance with one or more of the previous claims.
Method for the production of reinforced concrete floors characterised by the following steps:

a positioning of the traditional formworks destined to form the resting beams that will support the floor,

b preparation of the supporting structure, or scaffolding, designed to allow the placement of the required modular forms (1, 2; 10; 20; 21),

c positioning of said modular forms (1, 2; 10; 20; 21) on said scaffolding, laying them on their edges (1D; 2D; 10D; 20D; 21D) so to create bottom cavities (C),

said modular forms (1, 2; 10; 20; 21)

being provided in an amount apt to form globally a formworks having length and width equivalent to that of the floor to be produced and able to receive and contain the concrete cast (5)

and being arranged side by side in rows,

while said rows, at their turn,

are arranged side by side in order to form substantially rectilinear seats (D) open in the upper section, closed in the lower section and defined by the facing side walls (1B; 2B - 2C; 10B; 20B; 21B - 21C) of each adjacent form (1, 2; 10; 20; 21)

and, if prepared with forms (2) having only two side walls (1B), start and end with two forms (2) having three side walls (2B - 2C).

d positioning of

the reinforcing elements (3) within the seats (D) in a position that allows their extremity to extend up to the resting beams to be formed, as per the current praxis and rules.

and, if necessary of possible iron rods for the absorption of the moments negative stresses.

e preparation of the resting beams that will support the floor positioning its reinforcing iron rods,

f casting of the concrete (5) on the above-described structure till filling only the seats (D), the concrete (5) being dosed in accordance with calculation requirements,

g removal of the scaffolding after an adequate curing or consolidation of the concrete (5),

so obtaining a horizontal supporting structure consisting of parallel or crossed reinforced concrete ribs or beams with openings within the ribs to be left free or later covered with other materials.
Method, in accordance with the previous claim, characterised in that

in the step (d), also a traditional electrowelded wire mesh (4) is positioned over the upper walls (1A, 2A; 10A; 20A; 21A) of the forms (1, 2; 10; 20; 21), extending it up to the resting beams to be formed while possible iron rods for the absorption of the moments negative stresses are indifferently positioned on the upper portion of the seats (D) or over said upper walls (1A, 2A; 10A; 20A; 21A),

in the step (f) the casting of the concrete (5) covers also said upper walls (1A, 2A; 10A; 20A; 21A) with the necessary thickness, so obtaining a supporting roof in reinforced concrete having a continuous upper surface and consisting in a ribbed structure where the ribs are separated by lightening cavities (C) opened downwards.
Method, in accordance with the claims 35 or 36, characterised in that, after step (g) the above-described modular forms (1, 2; 10; 20; 21) are recovered be re-used.
Method, in accordance with claims 36 or 37, characterised in that modular forms (1, 2) are used, specifically designed to form, after their arrangement, reinforced concrete roofs having parallel and unidirectional ribs and a ceiling with parallel vaults.
Method, in accordance with claims 36 or 37, characterised in that modular forms (10; 20, 21) are used, specifically designed to form, after their arrangement, reinforced concrete roofs having crossed ribs and a lacunar ceiling.
Method, in accordance with claim 38, characterised in that modular forms (10; 20, 21) are used, specifically designed to form, after their arrangement, reinforced concrete roofs having crossed orthogonal ribs and a rectangular or square lacunar ceiling.
Method, in accordance with whichever claim from 35 to 40 characterised in that almost some of the adjacent cavities (C) are connected with passages within the ribs.
Method, in accordance with claim 41 characterised in that

during the step (c), connecting elements (30) are inserted by the inside of forms (20) to their outside trough the related cavities (20E) operating through adequate openings in the supporting scaffolding

after step (d) each connecting element (30) is coupled to its related connecting element (30),

after step (g) said connecting element (30) are removed first of removing said forms (20),

being possible to perform these operation just in correspondence of the cavities (C) to be connected by passages.
Method, in accordance with claim 41 characterised in that

after the step (d), disposable connecting elements that can be easily broken, preferably constituted by polystyrene foam cylinders, hollow in particular, are inserted trough the couples of related cavities (20E) of the forms (20),

after step (g) said disposable connecting elements are broken first of removing said forms (20),

being possible perform these operation just in correspondence of the cavities (C) to be connected by passages.
Method, in accordance with claim 41 characterised in that

after the step (d), tubular items (31) are pushed on their seats (21E) eventually using wedges of yielding material,

after removing said forms (21) possible crumbs are removed from the inside of the tubular items (31)

being possible perform these operation just in correspondence of the cavities (C) to be connected by passages.
Method, in accordance with one or more of the previous claim from 35 to 44, characterised in that, before the step (d), locking items (40) are pinned to the wooden bearing scaffolding by means of a nail in correspondence of one or more junctions of four vertexes of four adjacent forms (1, 2; 10; 20; 21)
Method, in accordance with whichever previous claim, characterised in that the lower surface of the floor is left open.
Method, in accordance with one or more of the previous claims from 1 to 45, characterised in that the lower surface of the floor is finished for aesthetic purposes and more specifically covered with a false ceiling.
Method, in accordance with one or more of the previous claims, characterised in that whichever operation necessary to complete the reinforced concrete structures may proceed according to the traditional praxis.
Modular forms (1, 2; 10; 20; 21) for the construction of horizontal supporting structures comprising a grid of parallel or crossed reinforced concrete ribs or beams for the construction of reinforced concrete ribbed floors, to be supported by resting beams, characterised in that they comprise:

an upper wall (1A, 2A; 10A; 20A; 21A),

at least two side walls (1B; 2B - 2C; 10B; 20B; 21B - 21C), defining an inner cavity (C) open at least downward

supporting elements or edges (1D; 2D; 10D; 20D; 21D) apt to lay on an underlying plane or scaffolding,

and an over-all shape apt to allow the extraction of said forms (1, 2; 10; 20; 21) from the reinforced concrete, once cured and solidified

and they are suited to allow the implementation of the method in accordance with one or more claims from 35 to 49.
Forms (1, 2; 10; 20; 21) for the production of floors, said modular forms (1, 2; 10; 20; 21), being designed

to be arranged in sequence and side to side, in order to form a substantially continuous surface suitable to receive and contain a concrete cast (5)

and to define, between side walls (1B; 2B - 2C; 10B; 20B; 21B - 21C) and edges (1D; 2D; 10D; 20D; 21D) of adjacent forms (1, 2; 10; 20; 21), seats (D)

extending substantially rectilinear from one to another resting beam

and apt to receive

a reinforcing elements (3), in particular bars or iron rods, extending in length between at least two opposed walls of the area,

b possible iron rods for the absorption of negative moment

c and a concrete (5) casting

so that, once the concrete has cured and solidified and the scaffolding has been removed, a supporting structure consisting in reinforced concrete beams is obtained.
Forms (1, 2; 10; 20; 21), in accordance with the previous claim, characterised in that said upper wall (1A, 2A; 10A; 20A; 21A) are apt to receive,

a traditional electrowelded wire mesh (4),

and a further concrete cast (5)

so that, once the concrete has cured and solidified and the scaffolding has been removed, a supporting roof in reinforced concrete having a continuous upper surface and consisting in a ribbed structure where the ribs are separated by lightening cavities (C) opened downwards is obtained.
Modular system for the formation of floors, characterised by the use of modular forms (1, 2; 10; 20; 21) that can be arranged in sequence or side by side in order to form a substantially continuous structure designed to receive and contain a concrete cast (5) which, after the above-described arrangement between the side walls (1B; 2B - 2C; 10B; 20B; 21B - 21C), substantially arranged longitudinally with a first set of modular forms (1, 2; 10; 20; 21) and the side walls (1B; 2B - 2C; 10B; 20B; 21B - 21C), substantially arranged longitudinally with a second set of modular forms (1, 2; 10; 20; 21), forms the base for a seat (D), open on the upper side and suited to receive:

first reinforcing elements (3) and in particular the bars or iron rods, which extend in length between at least two opposed walls of the area,

the concrete (5),

and the seats (D) as described above,

being in fact designed to create, after the positioning of the above-mentioned reinforcing elements (3), the casting of the concrete (5) and its subsequent consolidation, ribs or beams supporting the floor while the spaces, and more specifically the cavities, defined between the aforementioned opposed side walls (1B; 2B - 2C; 10B; 20B; 21B - 21C), of the same form (1, 2; 10; 20; 21) being instead used to form the lightening cavities (C).
System and/or method and/or modular forms for the production of floors in accordance with the instructions set forth in this description and in the enclosed drawings.