FR3039183A1 - PREFABRICATED FORMWORK ELEMENT, FORMWORK OBTAINED AND METHOD OF MANUFACTURING A SLAB OF A CONSTRUCTION COMPRISING A THROUGH-BYPASS RESERVATION DELIVERED BY SAID FORMWORK - Google Patents

Abstract

The invention relates to a prefabricated formwork element (1) arranged to produce a formwork (C) intended to provide in a slab (40) of a construction a traversing reservation (T) for the passage of a staircase, a elevator or the like. It comprises a profile provided with a vertical panel (11) comprising fixing means (14, 15) for collective protection equipment (G, F) against falls. It allows the safety of the formwork (C) at the beginning of the worksite by laying a fall arrest net (F) and a guardrail (G).

Description

PREFABRICATED FORMING ELEMENT. FORMWORK OBTAINED AND METHOD OF MANUFACTURING A SLAB OF A CONSTRUCTION COMPRISING A THROUGH-BYPASS RESERVATION DELIVERED BY SAID FORMWORK

Technical area :

The present invention relates to a prefabricated formwork element arranged to produce a formwork intended to provide, in a slab of a construction, a through-room for the passage of a staircase, an elevator or the like. The invention also relates to a formwork obtained from at least one shuttering element, as well as to a method of manufacturing a slab of a construction comprising a through-hole for the passage of a stairway, an elevator or similar.

Prior art:

In architecture, a traversing reservation made in a slab of a construction allowing the passage of a staircase, an elevator, a chimney, etc. is commonly called a hopper. The realization of this through-reservation requires the installation of a formwork usually made from a wooden frame or the like delimiting an open space in the slab.

Before the manufacture of the staircase, the elevator or the like, it is necessary to secure the gap opening defined by the formwork to prevent falls of person and equipment. To do this, it is known to set up, before the concrete pouring of the floor slab, a wooden decking that closes the opening defined by the formwork. After pouring concrete from the floor slab, it is also known to have peripheral railings supported by amounts fixed in the floor. However, the wooden decking has the disadvantage of being easily removable, which creates a potential risk of falling for the staff working on the site. In addition, the decking can be likened to a storage area and can cause accidents due to the low strength of the decking. On the other hand, the railings do not allow to secure the through-hole before pouring the concrete, since they are integrated once the floor is made.

Consequently, the solutions of the prior art do not make it possible to guarantee a protection and a security of the traversing reservation defined by the formwork which are optimal against the risks of falls and this throughout the duration of the work.

Presentation of the invention

The present invention aims to overcome these disadvantages by proposing a formwork solution for securing a traversing reservation in a slab of a construction in a simple, fast and reliable manner during all phases of the worksite, safely from the lower floor, and this since the installation of the formwork, this formwork solution being versatile to be able to adapt to any form of traversing reservation and floor.

For this purpose, the invention relates to a formwork element of the kind indicated in the preamble, characterized in that it comprises a profile, provided with at least one vertical panel arranged to delimit at least a rectilinear portion of the bank of said reservation through, said vertical panel comprises fastening means for collective protection equipment against falls.

Said section may be rectilinear and include connecting means arranged to be coupled to at least one beam of said slab.

Said section may also be rectilinear and have a shape of L, and have a horizontal panel forming a support plate of said vertical panel, said horizontal panel comprising receiving means for members carrying said shuttering element.

The fixing means are advantageously arranged to allow the attachment of a railing for protecting access to said formwork. These fastening means of said railing may comprise at least one vertical tubular housing, accessible from above said vertical panel, and arranged to receive by interlocking a vertical amount of said railing.

The fixing means may also be arranged to allow the attachment of a fall arrester to protect the opening defined by said formwork. These attachment means of said fall arrest net may comprise at least one vertical attachment rod, accessible on the opposite side to said horizontal panel and forming with said vertical panel a space for receiving a portion of the perimeter of said fall arrest net around said fastening rod.

The receiving means may comprise at least two flat bottom reservations distributed on the underside of said horizontal panel and arranged to receive the planar ends of said carrier members.

In a preferred embodiment, said formwork element comprises stiffening means integrated in said vertical panel and / or in said horizontal panel.

Preferably, it comprises assembly means disposed at opposite ends of the vertical panel and arranged to allow the assembly of adjacent formwork elements aligned or at right angles to form a formwork. These assembly means may comprise at one end a male end and at the other end a female endpiece of complementary shape to said male end, said end pieces extending vertically and delimiting an interlocking abutment so that the formwork elements adjacent are assembled by a vertical nesting and that their horizontal panels are at the same level.

For this purpose also, the invention relates to a formwork of the kind indicated in the preamble, characterized in that it comprises at least one shuttering element, as defined above, forming a polygonal closed frame.

The formwork may also include a plurality of formwork elements assembled together by said connecting means provided at opposite ends of each formwork element to form a closed polygonal frame.

The formwork may also consist of a single piece.

The horizontal panels of said assembled formwork elements are preferably oriented outside said polygonal closed frame delimited by said formwork. Π may also comprise at least two straight cover elements each disposed between two aligned and remote formwork elements to form a closed polygonal frame whose at least two opposite sides are not multiples of a formwork element. Π may also comprise at least one angled cover element disposed between two parallel and remote formwork elements to form a closed polygonal frame at least one side has a recess. The invention finally relates to a manufacturing method of the type indicated in the preamble, characterized in that: - at least one formwork element such as defined above to form a formwork as defined above, - is set up, in the fastening means of said formwork elements, collective protection equipment against falls to secure said traversing reservation defined by said formwork before pouring the slab.

Preferably, at least one fall arrester is secured to the corresponding fastening means of said at least one formwork element accessible from the inside of the formwork to close said traversing reservation.

Preferably, at least one railing is mounted in the fastening means of said at least one formwork element accessible from above the formwork to prevent access to the through-hole.

Preferably, a plurality of adjacent formwork elements are assembled by their assembly means.

In this case, during the assembly of said formwork elements the horizontal panels of the shuttering elements are oriented outside said formwork and the vertical panels delimit the banks of said traversing reservation.

When laying said shuttering elements, the corresponding ends of the support members are positioned in the receiving means of said shuttering element.

During the assembly of said formwork elements, it is also possible to add at least two right covering elements each disposed between two aligned and distant formwork elements to form a formwork of which at least two opposite sides are not multiples of a formwork element.

During the assembly of said formwork elements, it is also possible to add at least one corner covering element arranged between two parallel and distant formwork elements to form a formwork of which at least one side comprises a recess.

Brief description of the drawings:

The present invention and its advantages will become more apparent in the following description of an embodiment given by way of non-limiting example, with reference to the appended drawings, in which: FIGS. 1A, 1B, 1C are several perspective views of FIG. a formwork element according to the invention, respectively seen from the top, seen from the rear and bottom view, Figure 2 is a top view in perspective of a formwork obtained by the assembly of several formwork elements of the figures IA, IB, IC, FIG. 3 is a fragmentary, exploded perspective view of a covering element used in the formwork of FIG. 2, FIG. 4 is a partial perspective view of the interior of the formwork of FIG. FIG. 2 showing the fixing of a fall arrest net, and FIGS. 5A, 5B, 5C and 5D are perspective views of a slab during manufacture respectively showing the implementation of a formwork according to the invention. on load-bearing members, the installation of a fall arrest net to secure the opening defined by the formwork and the laying of the beams, the installation of interjoists and reinforcement, and the slab cast around said secured formwork, then the laying of a railing to secure access to the formwork.

Illustrations of the invention and best way to achieve it:

With reference to the figures, the invention relates to a formwork element 1 used to form a formwork C. The formwork C can be obtained by assembling several formwork elements 1 between them. According to a preferred application of the invention, the shuttering element 1 is used to produce the formwork C of a through-hole T, commonly called a hopper, in a slab of a construction, making it possible to reserve a passage for the subsequent manufacture. a staircase, an elevator or similar. The formwork element 1 that will be described has the advantage of enabling the security of the traversing reservation T during the various phases of manufacture of the slab by the installation of collective protection equipment, such as a guard of body G and / or a fall arrester F, and this from the beginning of the site, without these collective protection equipment G, F does not hinder the work of the workers during the various stages of the site. In general, slab means any slab that requires the casting of a concrete in whole or complementary to a prefabricated element, such as a cast-in-place slab, a floor slabs, a hollow slab, a floor with girders.

Referring more particularly to Figures IA to IC, the formwork element 1 is in the form of an L-shaped rectilinear profile having a vertical panel 11 and a horizontal panel 12. In the example shown, the vertical panel 11 has an outer wall 111, disposed on the side of the horizontal panel 12, arranged to define a straight portion of the bank of the through-hole T, and an inner wall 112 opposite the outer wall 111, arranged to be arranged inside. of formwork C. As explained below, these walls 111, 112 are structured and not smooth. The notions of inner and outer walls are defined with respect to the inside and outside of the formwork C. In addition, the horizontal panel 12 forms a support plate of the vertical panel 11 and has an upper face 121, preferably flat and smooth arranged to delimit a portion of the underside of the slab bordering the traversing reservation T, and a lower face 122 opposite the upper wall 121 structured as explained below. The shuttering element 1 is preferably made of a single piece, obtained by molding, injection or the like. Of course, the formwork element 1 can be manufactured in two separate pieces then assembled, without this variant modifying the extent of the protection. For the manufacture of the formwork element 1, a synthetic material is preferred, such as plastic, for example polypropylene, or the like, or a composite material. Of course, these examples are not limiting. Preferably, this formwork element 1 includes stiffening means, explained below, making it possible to give it the desired mechanical strength so that it can fulfill its various functions, namely shuttering functions for a slab cast in a material. hydraulic, but also functions of maintenance and support for existing collective protection equipment protecting the workers against the falls of person and object. In a variant of the invention not shown, the shuttering element is rectilinear and comprises only a vertical panel. In addition, it comprises connecting means arranged to be attached to the beams forming the slab. More particularly, these connecting means may consist of two bars arranged in parallel in the lower part of the vertical panel and spaced from each other by a specific space, and hooks projecting transversely to the vertical panel. The bars allow to receive the protruding part of the sole of the beam and the hooks to hang the main portion of the beam. In another variant not shown, the shuttering element may have the shape of a polygonal frame whose shape corresponds to the through-hole. In this case, the formwork element and the formwork merge and form a single piece.

The vertical panel 11 comprises fastening means 14, 15 which make it possible to fix collective protection equipment, such as a guard rail G and a fall arrest net F. The illustrated example has both fastening means 14 and a guardrail G and means for fixing a fall arrest net F. However, it is possible to provide only one or other of these fastening means 14, 15, or to use on the construction site. that one or the other of collective protection equipment G, F.

In the example illustrated, the fastening means 14 of a railing G comprise two vertical tubular housings 141, aligned, spaced from one another and integrated between the outer 111 and inner 112 walls of said vertical panel 11. They extend substantially over the entire height of the vertical panel 11 and are open at the top to be accessible from above the formwork C and closed at the bottom to form a stopper. They furthermore have a section complementary to that of the uprights M of a railing G to receive them by simple mechanical male / female fitting requiring no additional fastening means, as shown in FIG. 4. The height of the tubular housings 141 is sufficient to ensure effective maintenance of the railing G without the amounts M can out of said housing accidentally. The height of the tubular housing corresponds to the standards in force. In the example shown, this section is circular. But this example is not limiting and extends to any other known section for uprights of a guardrail or other equivalent collective protection equipment. Similarly, the design of these fastening means 14 may differ from the illustrated example, the main point being that the uprights M of a railing G can be nested vertically by the top of the formwork C quickly and simply, without tools to prevent access to the interior of the formwork C. On the other hand, the present invention is not limited to two tubular housing 141 per formwork element 1. Indeed, this number may be equal to one or more in two, depending on the length of the formwork element 1 and the type of guard rail G used.

Additionally, the fastening means 14 comprise vertical grooves 142 which are arranged on the inner wall 112 of the vertical panel 11. The grooves 142 extend over the entire height of the vertical panel 11 and are aligned with the tubular housings 141. These grooves 142 may receive transverse reinforcing planks P as shown in Figure 5C. These boards are usually used to reinforce the formwork by providing additional rigidity in order to be able to implement bodyguard tubes from the provisional phase.

In the example illustrated, the fastening means 15 for a fall arrest net F comprise three vertical hanging rods 151, aligned, spaced from each other and integrated between the outer 111 and inner 112 walls of said vertical panel 11. They are of preferably arranged alternately with the tubular housings 141 described above, for the purpose of balancing the forces supported by the shuttering element 1. The hooking rods 151 extend over the entire height of the vertical panel 11, are accessible from the side of the inner wall 112 of the vertical panel 11 which is open to the right of the rods, and are spaced from the outer wall 111 of a space 152. The combination of the attachment rod 151 and the space 152 defines a C-shaped attachment zone which allows the fixing of a fall arrest net F. Indeed, as shown in FIG. 4, the fall arrest net F is surrounded by a rope R which is threaded over each attachment rod 151 and is housed in the space 152 between the outer wall 111 and the attachment rod 151. The height of the attachment rods 151 is defined to prevent accidental removal of the fall arrest net F. Of course, the present invention is not limited to three attachment rods 151 per formwork element 1, this number may be at least one. Similarly, the design of these fastening means 15 may differ from the illustrated example, the essential is to be able to fix quickly, simply and without tools, a fall arrester or any equivalent collective protection equipment to close the through reservation bounded by formwork C.

In the example illustrated in FIG. 1C, the horizontal panel 12 of the shuttering element 1 comprises receiving means 16 for support members E arranged to support the shuttering C in the vacuum at a height corresponding to that of the slab to manufacture in construction. These receiving means 16 comprise five reservations 161 flat bottom, distributed on the lower face 122 of the horizontal panel 12. They are arranged to receive the support plates provided at the ends of the struts E, as shown in Figure 5A. Of course, any other carrier member other than struts may be suitable. In this case, the shape and dimensions of the bookings 161 are adapted. Similarly, the number of reservations per formwork element 1 is not limited and can be less than or greater than five depending on the length of the formwork section 1 and the type of carrier member E. The formwork element 1 further comprises assembly means 18 provided at its two opposite ends 110, and more particularly at the two opposite ends of the vertical panel 11, to be able to join together adjacent formwork elements 1, as shown in FIG. assembly means 18 preferably have complementary shapes between the two ends 110 of the same shuttering element 1, in order to be able to manufacture a single type of shuttering elements 1. More particularly, one of the ends 110 comprises a spigot end 181 at the bottom and the opposite end 110 has a female end 182 at the top, each end extending vertically about half the height of the vertical panel 11 and forming for the other end a nesting abutment. The male end-piece 181 comprises a stud surmounted by a stud 181a, while the female end-piece 182 comprises a stud provided with an orifice 182a for receiving the stud 181a by vertical fitting of a shuttering element 1 with respect to a other. Such assembly means 18 allow to assemble quickly and simply, without additional tools, several formwork elements 1 side by side aligned or at right angles to form a closed polygonal frame depending on the formwork C to achieve. The horizontal face of the studs of the male end pieces 181 and female 182 in correspondence between two consecutive formwork elements 1 limits the interlocking depth and ensures the leveling of the formwork elements 1 and in particular that of their horizontal panels 12.

According to the illustrated example, the formwork element 1 comprises stiffening means 17. More particularly, the vertical panel 11 is structured and comprises in its thickness between its outer 111 and inner walls 112 ribs 171 and vertical grooves 172 , some of which are dovetail shaped. Thus, these walls 111, 112 are not full or smooth. The various shapes that comprise the vertical panel 11, namely the tubular housings 141, the attachment rods 151, the ribs 171 and the grooves 172, are advantageously alternated and distributed over its entire length in order to balance the efforts that the formwork element 1 must support. Other embodiments are possible, however, without the illustrated example being restrictive.

Similarly, the horizontal panel 12 has in its thickness between its upper faces 121 and lower 122 indentations 173, visible on the lower face 122. These indentations 173 are preferably perpendicular to the longitudinal axis of the formwork element 1 and spaced at a constant pace.

Of course, the invention is not limited to these examples of stiffening means 17 but extends to any other embodiment compatible preferably to a manufacturing method by molding or injection of a synthetic material. In addition, these stiffening means 17 can reduce the amount of raw material required for the manufacture of formwork elements 1, without impairing their mechanical strength in terms of flexion, compression and traction. The shuttering element 1 as described allows the manufacture of a formwork C as illustrated by way of example in Figure 2 by assembling several formwork elements 1 to form a closed polygonal frame. Of course, as described above, in an alternative embodiment not illustrated, the formwork C can also be monoblock and in this case no assembly is necessary. In the example shown, the formwork C has a rectangular shape, without this form being limiting. Indeed, it may have a square shape, or an L shape as explained below. Π is designed from six identical formwork elements 1, of which two formwork elements 1 form the two short sides and four formwork elements 1 form the two long sides. These two long sides not being multiples of a shuttering element 1, two covering elements 20 have been added, one on each side between two formwork elements 1 aligned. The formwork elements 1 which are adjacent form the angles of the formwork C and are assembled together at right angles by their assembly means 18, positioning their horizontal panels 12 outside the formwork C. The element overlap 20 is illustrated in more detail in FIG. 3 and comprises an L-shaped section of predefined length, provided with a vertical wall 21 arranged to be superimposed on the outer wall 111 of a vertical panel 11, and of a horizontal wall 22 arranged to be superimposed on the upper face 121 of a horizontal panel 12, without creating troublesome extra thickness for the realization of the slab. Thus, when positioned between two formwork elements 1 aligned but not adjacent, it ensures the continuity of the formwork C, delimiting the bank of the traversing reservation T and the slab bordering this reservation. To be assembled easily and without tools to the formwork elements 1, it has at one end of its vertical wall 21 a vertical rib 23 shaped dovetail, which extends over the height of the vertical wall 21 and which is arranged to fit vertically into one of the grooves 172 of complementary shape of the vertical panel 11 of one of the shuttering elements 1 which it covers in part. The other end of the covering element 20 is fixed to the other shuttering element 1 which it partially covers, by a separate assembly part 30. This assembly part 30 comprises a tube forming a rib 31 in the form of a dovetail arranged to fit vertically in one of the grooves 172 of complementary shape provided in the vertical panel 11 of the corresponding formwork element 1. It comprises in the upper part and in the lower part two assembly tabs 32, 33, arranged to fit respectively on the top edge 24 and in a groove 25 formed in the lower part of the vertical wall 21 of the covering element 20 Of course, any other means of assembling the covering element 20 to the shuttering elements 1 may be suitable. This covering element 20 may also have a right-angle shape, making it possible to create a formwork C whose at least one side has an L-shaped recess. Thus, the formwork element 1, associated or not with one or more elements of cover 20 right and / or angle, allows for all forms of formwork C polygonal. The cover element 20 and the assembly part 30 may, like the shuttering element 1, be made by molding, injection or the like in a synthetic or composite material, identical or not to the material of the shuttering element 1. The height of these elements 1, 20, 30 is determined according to the height of the slab to be built. This height can vary depending on the slab to build.

Possibilities of industrial application:

As seen above, the shuttering element 1 is advantageously designed as a specific part for a given slab height, considerably simplifying its manufacture and management while reducing the corresponding production costs. In addition, the formwork element 1 is a lightweight, non-fragile, easy to handle and transport by workers working on a construction site, without risk of injury. The same applies to the covering element 20 and to the assembly part 30. The covering element 20 having no proper mechanical function, its walls 21 and 22 can be relatively thin and smooth, without any means. stiffener.

The method of manufacturing a slab 40 in a construction having at least one traversing reservation T for the passage of a staircase, an elevator or the like is now described with reference to Figures 5A to 5D. In the example shown, the slab 40 is made from prestressed beams 42 and prefabricated interjoists 43 to produce the supporting structure of the slab 40. The slab can also be obtained from reinforced concrete beams. This construction example is not limiting and the invention extends to any other equivalent form of construction.

FIG. 5A shows a load-bearing wall 41, on the right of which is positioned a formwork C delimiting a through-hole T. This formwork C is carried by bearing members E which consist of struts, it being specified that any other bearing member that may be suitable. The formwork C is made simply and quickly. The worker places the formwork elements 1 one after the other, each on at least one or two struts E and assembles progressively the formwork element 1 according to the previous formwork element 1. The support members E are positioned at the right of the reservations 161 provided under each formwork element 1, in the lower face 161 of the horizontal panel 12. The formwork C obtained in the example shown is the result of the assembly of six elements of identical formwork, forming a closed rectangular frame.

Figure 5B shows the C formwork secured by the installation of a fall arrester F set up from below or from above the formwork C. To do this, the R rope R provided around the fall arrester F was hung around each attachment rod 151 accessible from the inside of the formwork C, as illustrated in FIG. 4. This FIG. 5B shows that the formwork C is secured from the beginning of the worksite, even before the prestressed beams 42 are laid down, and that the fall arrest net F does not hinder the work of the workers. This figure also shows the installation of the prestressed beams 42 near the formwork C. The prestressed beams 42 positioned in the extension of the formwork C rest by their corresponding ends on the horizontal panels 12 of the formwork elements 1 parallel to the bearing wall 41. The beams prestressing 42 bordering the sides of the formwork C which are perpendicular to the carrier wall 41 are doubled and rest at their ends on the carrier wall 41. They also rest on part of their length on the horizontal panel 12 of the corresponding formwork elements 1.

Figure 5C shows the C formwork secured by the installation of a guard rail G on all three accessible sides. Each vertical upright M of the railing G has been placed in one of the tubular housings 141 accessible from above the formwork C.

Then horizontal rails L of the railing G have been positioned in the receiving notches provided for this purpose on the uprights M. Thus, this railing G is quickly put in place, without tools, and does not hinder the work Workers. This FIG. 5C also shows the installation of the interjoists 43 in the spans delimited between the prestressed beams 42 and the reinforcement 44.

FIG. 5D shows the slab 40 completed after pouring the concrete or any other suitable hydraulic material, and the formwork C still safe thanks to the presence of the fall arrester F and the railing G. The upper stage of the construction can be continue with the creation of a new slab in which a new formwork C can be put in place as in Figure 5A. During the manufacture of a staircase, an elevator, or the like, the collective protection equipment F and G associated with each formwork C can be dismantled. It is clear from this description that the invention achieves the goals set, namely a formwork performing in terms of implementation and protection of people. The present invention is not limited to the embodiment described but extends to any modification and variation obvious to a person skilled in the art.

Claims (25)

claims 1. prefabricated formwork element (1) arranged to produce a formwork intended to form in a slab (40) of a construction a traversing reservation (T) for the passage of a staircase, an elevator or the like, characterized in it comprises a profile, provided with at least one vertical panel (11) arranged to delimit at least a rectilinear part of the bank of said traversing reservation (T), in that said vertical panel (11) comprises means fixing device (14, 15) for collective protection equipment (G, F) against falls. 2. shuttering element according to claim 1, characterized in that said profile is rectilinear and comprises connecting means arranged to be coupled to at least one beam of said slab. 3. Formwork element according to claim 1, characterized in that said section is rectilinear and has an L shape, and comprises a horizontal panel (12) forming a support sole of said vertical panel (11), and in that said horizontal panel (12) comprises receiving means (16) for supporting members (E) of said shuttering element (1). 4. shuttering element according to claims 1 to 3, characterized in that said fixing means (14) are arranged to allow the attachment of a railing (G) for protecting access to said formwork (C). 5. shuttering element according to claims 4, characterized in that the fastening means (14) of said railing (G) comprise at least one tubular housing (141) vertical, accessible from above said vertical panel (11), and arranged to receive by interlocking a vertical amount (M) of said railing (G). 6. shuttering element according to claims 1 to 3, characterized in that said fixing means (15) are further arranged to allow the attachment of a fall arrester (F) for protecting the opening defined by said formwork ( VS). 7. shuttering element according to claim 6, characterized in that the fastening means (15) of said fall arrester (F) comprise at least one fastening rod (151) vertical, accessible on the opposite side to said horizontal panel (12). and forming with said vertical panel (11) a space (152) for receiving a portion of the perimeter of said fall arrest net (F) about said attachment rod (151). 8. shuttering element according to claim 3, characterized in that said receiving means (16) comprise at least two reservations (161) flat bottom distributed on the lower face (120) of said horizontal panel (12) and arranged to receive the planar ends of said carrier members (E). 9. shuttering element according to claims 1 to 3, characterized in that it comprises stiffening means (17) integrated in said vertical panel (11) and / or in said horizontal panel (12). 10. shuttering element according to any one of the preceding claims, characterized in that it comprises connecting means (18) disposed at opposite ends (110) of the vertical panel (11) and arranged to allow the assembly of adjacent formwork members (1) aligned or at right angles to form a formwork (C). 11. shuttering element according to claim 10, characterized in that said connecting means (18) comprise at one end (110) a male end (181) and at the other end (110) a female end (182). of complementary shape to said male end, said end pieces (181, 182) extending vertically and delimiting an interlocking abutment so that the adjacent formwork elements (1) are assembled by a vertical interlocking and their horizontal panels (12) ) are at the same level. 12. Formwork (C) arranged to fit in a slab (40) of a construction a traversing reservation (T) for the passage of a staircase, an elevator or the like, characterized in that it comprises at least one shuttering element (1), according to any one of the preceding claims, forming a polygonal closed frame. 13. Formwork according to claims 12 and 10, characterized in that said formwork (C) comprises a plurality of shuttering elements (1) assembled together by said connecting means (18) provided at the opposite ends of each element of shuttering (1) to form a closed polygonal frame. 14. Formwork according to claim 12, characterized in that it consists of a single piece. 15. Formwork according to claim 13, characterized in that the horizontal panels (12) of said formwork elements (1) assembled are oriented outside said polygonal closed frame defined by said formwork (C). 16. Formwork according to claim 13, characterized in that it further comprises at least two covering elements (20) right each disposed between two shuttering elements (1) aligned and distant to form a closed polygonal frame of which at least two opposite sides are not multiples of a formwork element (1). 17. Formwork according to claim 13, characterized in that it further comprises at least one cover member (20) at an angle disposed between two shuttering elements (1) parallel and remote to form a closed polygonal frame at least one side has a recess. 18. A method of manufacturing a slab (40) of a construction comprising at least one traversing reservation (T) for the passage of a staircase, an elevator or the like, characterized in that: - it has at a predetermined location in said slab (40) on bearing members (E) or beams (42) of said slab (40) at least one shuttering element (1), according to any one of claims 1 to 11 to form a formwork (C) according to any one of claims 12 to 17, - is placed in the fastening means (14, 15) of said formwork elements (1), collective protection equipment ( G, F) against falls to secure said traversing reservation (T) delimited by said formwork (C) before pouring the slab. 19. Manufacturing process according to claim 18, characterized in that at least one fall arrest net (F) is fastened to the corresponding fixing means (15) of said at least one shuttering element (1) accessible from the inside. formwork (C) for closing said traversing reservation (T). 20. Manufacturing process according to claim 18, characterized in that at least one guardrail (G) is mounted in the fastening means (14) of said at least one formwork element (1) accessible from above. formwork (C) to prohibit access to the through-hole (T). 21. Manufacturing process according to claims 18 and 10, characterized in that a plurality of adjacent formwork elements (1) are assembled by their assembly means (18). 22. Manufacturing process according to claim 21, characterized in that during the assembly of said shuttering elements (1) the horizontal panels (12) of the shuttering elements (1) are oriented outside said shuttering (C) and the vertical panels (11) delimit the banks of said traversing reservation (T). 23. Manufacturing method according to claims 22 and 3, characterized in that, during the laying of said formwork elements (1), the corresponding ends of the carrier members (E) are positioned in the receiving means (16). said shuttering element (1). 24. Manufacturing process according to claim 21, characterized in that, during the assembly of said shuttering elements (1), at least two straight covering elements (20) are each arranged between two shuttering elements ( 1) aligned and spaced to form a formwork (C) of which at least two opposite sides are not multiples of a formwork element (1). 25. Manufacturing process according to claim 21, characterized in that, during the assembly of said shuttering elements (1), at least one cover element (20) is added at an angle disposed between two shuttering elements ( 1) parallel and spaced to form a formwork (C) of which at least one side has a recess.