EP2206847A1 - Formworking panel with secured setting - Google Patents

Abstract

The panel (1) has a cleat (6) comprising an end attached to a rib (4). A portion of the cleat adjacent to the end has a width smaller than that of another part that is adjacent to a free end of the cleat. Contours of the parts form a projection at a junction between the parts and at a predetermined distance from one of the ends of the cleat. The projection forms a stop block (7) to prevent passage of the cleat outside an orifice (5) of a stiffener (3) under an effect of pressure force exerted on a slatted metal sheet (2). The sheet is set at an intersection between the stiffener and the rib. Independent claims are also included for the following: (1) a formwork comprising two panels connected by connection elements (2) a slab comprising reinforcement frameworks and a concrete layer arranged on a face of a panel (3) a tooling for setting a set of stiffeners at a slatted sheet.

Description

Field of the invention

The present invention relates to the field of formwork for the construction of a wall or slab of concrete or similar material. More specifically, it refers to the formwork walls or shuttering panels that constitute the formwork itself. A panel comprises a screen sheet extending over vertical bars called stiffeners spaced at predefined intervals attached to the screen sheet.

In the case of a wall or a wall, the formwork is formed by panels arranged vertically and parallel to each other opposite. They can be connected by a connecting device creating a space to be filled with a material such as concrete.

Such a formwork system is generally used as a formwork lost or integrated that is to say that it remains as an integral part of the wall after pouring the concrete in the space between the two panels.

Technical background

The document WO2005042864 describes a high-strength formwork for a concrete wall comprising two parallel formwork walls placed facing each other and provided with profiled bars forming vertical stiffeners. The walls are connected by an articulated connection device for maintaining the formwork walls at a spacing defining a space for receiving a filling material such as concrete. The articulation of the connecting device makes it possible to fold the formwork for storage and transport. The connecting device comprises a pair of horizontal straight bars parallel to the formwork walls. The bars placed one opposite the other through the stiffeners of the respective walls. The connecting device also comprises a plurality of connecting bars perpendicularly connecting the two horizontal bars around which they articulate.

The formwork with its two formwork walls equipped with stiffeners and assembled with the connecting devices are prefabricated at the factory. It is transported to the construction site in folded form thanks to the joints of the elements of links on the stiffeners. The advantage of such a formwork is its maneuverability and speed of assembly on site with a minimum of tools and manpower. In order to minimize the overall construction costs and to ensure a high quality of the erected walls, each step of the formwork manufacture must be optimized both in speed of execution and reliability of the components or the finished product. An important component here is the formwork wall or the formwork panel designed to withstand the deformations due to the pressure and weight of concrete poured into the formwork formed by these panels.

The document FR2712016 discloses a method of manufacturing formwork walls comprising an expanded metal plate provided with V-shaped parallel ribs. This mesh plate is attached to a plurality of stiffeners spaced at regular intervals and arranged perpendicularly to the ribs of the plate. The method comprises a stapling operation of the stiffeners on the plate, a first step consists in punching off tabs on one of the faces of the stiffeners. In a second step, these tabs are folded over the ribs of the plate after passing through the mesh on each side of the ribs.

The document FR2497857 discloses a prefabricated panel comprising a frame formed of profiled stiffeners covered by a perforated metal sheet and at least one layer of coating material such as concrete. The stiffeners comprise tabs, issuing from one of the faces of the profile, passing through the perforated sheet to be folded on the outer face thereof so as to hook said sheet to the stiffeners.

The document W02007 / 079989 discloses a panel for formwork of concrete walls or slabs comprising a mesh metal sheet reinforced on the one hand by a plurality of stiffeners formed of rigid profiled metal bars integral with one side of said sheet arranged parallel to each other and spaced apart at predefined intervals, and secondly by ribs integrated in the mesh of the sheet. These ribs are spaced at predefined intervals and crossing the stiffeners preferably at right angles. The mesh sheet is attached to the stiffeners by crimping at at least one intersection between the ribs and the stiffeners. The crimping is performed so that at least one tongue coming from the metal of the rib maintains the stiffener through a corresponding orifice of said stiffener. The tongue is folded against the inner face of the stiffener around the edge of the orifice so as to press the mesh sheet against the stiffener.

According to a practical embodiment, the orifice is stamped in the form of a rectangle so as to create tabs both in the metal of the rib and in that of the stiffener attached to the two small opposite sides of the rectangle. The tabs directed towards the inner face of the stiffener profile are then folded against this face in an area adjacent to the short sides of the rectangle.

Tests with formwork made of panels with grid crimped according to the above method have shown that under a high pressure exerted by poured concrete between the two panels, the folded tabs of the ribs can straighten and pass through the stiffener orifice. This loosening of the crimping results in a local detachment of the mesh sheet from the stiffener and causes undesirable bulges of the outer surface of the formwork filled with concrete. The detachment of the mesh sheet can even be generalized to the entire formwork wall if it is not detected in time during the pouring of the concrete. This phenomenon is further accentuated when the quality, the thickness and the hardness of the steel used. for the manufacture of the mesh are insufficient.

When the tongues are folded on the outer face of the walls as in the stapling of the stiffeners to the mesh described in the document FR2712016 , the pressure of the concrete can also cause a recovery of the tongues. The latter, by disengaging mesh of the mesh, cause the stall of the formwork wall and deformations on the surface of the realized wall. The attachment of the formwork wall to the stiffeners as presented in the document FR2497857 Moreover, there is a similar disadvantage of straightening the hook under the pressure of the concrete.

Fastening with screws or other fastening means adds additional parts to the panel, which is undesirable when the manufacturing has to be streamlined and automated to the maximum especially for large series.

• le sertissage peut se réaliser avec un outillage automatisé, indépendamment des conditions extérieures et sans altération du traitement de surface de l'acier qui est en général galvanisé.
• les défauts éventuels de fixation par sertissage sont visibles immédiatement et peuvent être corrigés avant la sortie du coffrage de l'usine.
• le sertissage ne dégrade pas le traitement de surface de l'acier comme le ferait la soudure par oxydation des points de fixation de la feuille grillagée nuisant à la durée de vie du mur construit avec le coffrage intégré.
• le sertissage ne nécessite pas un environnement particulièrement propre et exempt de poussières impliquant des conditions de fabrication onéreuses à mettre en place et à respecter.

Compared to spot welding, the crimping of the mesh to the stiffeners has significant advantages, namely:

• crimping can be achieved with automated tooling, regardless of external conditions and without altering the surface treatment of steel which is usually galvanized.
• any crimping fixing defects are visible immediately and can be corrected before the factory shuttering is removed.
• crimping does not degrade the surface treatment of the steel as would the oxidation welding of the attachment points of the mesh sheet adversely affecting the life of the wall built with the integrated formwork.
• crimping does not require a particularly clean and dust-free environment involving expensive manufacturing conditions to implement and respect.

Brief description of the invention

The object of the present invention is to significantly improve the strength of the crimping of the prior art while retaining the advantages of crimping with respect to the fixing of the mesh by welding and other fastening means. In addition, crimping reduces production costs and streamlines the mass production of factory formwork panels while ensuring maximum strength for walls built with this type of formwork.

This object is achieved by a panel for formwork of walls or concrete slabs comprising a mesh metal sheet reinforced on the one hand by a plurality of stiffeners formed of profiled rigid metal bars arranged parallel to each other and spaced at predetermined intervals and on the other hand ribs integrated in the mesh of the sheet spaced at predetermined intervals and crossing the stiffeners, the mesh sheet being fixed on the stiffeners by means of a crimping performed at at least one intersection between a rib and a stiffener so that at least one metal portion of the rib, forming a tongue having one end attached to the rib and a free end, holds the stiffener through an orifice of said stiffener, the orifice having a shape corresponding to the shape of the tongue, said panel is characterized in that the tongue comprises, at sinage of the end attached to the rib, a first portion of width less than the width of a second portion in the vicinity of the free end, the contour of the two parts forming at their junction at least one recess at a predetermined distance from one end of the tongue, said recess forming a stop preventing the release of the tongue out of the corresponding hole under the effect of pressure forces exerted on the wire mesh sheet.

In practice, during the construction of a wall, the formwork is placed on a substantially horizontal surface (floor or floor slab) so that the stiffeners of the panels are arranged in the vertical direction. The ribs of the grid sheet perpendicularly cross the stiffeners and are therefore arranged horizontally and preferably at regular intervals over the entire height of the panel. The notions of vertical and horizontal are relative because the entire formwork can be rotated at an angle of 90 °. Thus the vertical elements at the beginning become horizontal and vice versa.

A panel can be used as a single wall and placed either vertically against a wall to form a simple formwork, or horizontally for the realization of slabs.

In the case of a wall or wall, the form is formed by two panels arranged vertically and parallel to each other. They can be connected by a connecting device creating a space to be filled with a material such as concrete. A panel can be arranged vertically against a wall to form a simple formwork. It can also be used as a basis for the construction of various civil engineering works such as a slab of floor or roof, poles, beams, pillars etc.

A panel can be arranged vertically against a wall to form a simple formwork. It can also be used as a base for the construction of a slab or roof, poles, beams, pillars and various civil engineering works can be built using the panel

The ribs are profiled V-shaped or U-shaped solid metal parts integrated into the mesh of the sheet for stiffening stiffening manner.

The grid sheet is preferably attached at each intersection of a rib with a stiffener to minimize deformations caused by the weight of concrete poured into the formwork using these panels. This fixing is performed by crimping in which at least one tongue of the metal of the rib is cut by stamping and bent in a corresponding hole of the stiffener.

At the point where the width of the tongue changes, the recess forms a stop which prevents the exit of the tongue out of the orifice under the effect of pressure forces exerted by the concrete on the mesh. This stop bears against the stiffener on one side of the narrow part of the corresponding orifice.

A preferred form of the tongue comprises two recesses forming two symmetrical abutments facing one another. These abutments bear against the stiffener on each side of the narrow portion of the orifice under the effect of pressure forces on the grid sheet.

Brief description of the figures

• la figure 1 représente un sertissage selon l'invention à une intersection entre un raidisseur et une nervure de la feuille grillagée.
• la figure 2a montre une vue schématique des languettes du sertissage redressées de chaque côté de l'orifice.
• la figure 2b montre les languettes de la figure 2a rabattues de chaque côté de l'orifice.
• la figure 2c illustre la position des languettes et l'effet des butées lorsqu'une pression est exercée sur la feuille grillagée.
• la figure 2d illustre un exemple de languettes opposées rabattues comportant chacune un décrochement disposé en quinconce l'un par rapport à l'autre.
• la figure 3a représente une vue frontale de l'extrémité d'une étampe servant à découper les languettes et former l'orifice que les languettes traversent pour réaliser le sertissage.
• la figure 3b montre une vue de dessus de l'extrémité de l'étampe de la figure 3a
• la figure 3c montre un orifice tel qu'il serait usiné dans un support fixe avec un contour correspondant à celui d'une section de l'étampe.
• la figure 4 illustre schématiquement sur une vue en coupe d'un raidisseur l'étape de rabattement des languettes étampées contre la face interne d'un raidisseur.
• la figure 5 illustre schématiquement le résultat obtenu après rabattement des languettes contre la face interne du raidisseur.
• la figure 6 illustre schématiquement une variante du sertissage dans laquelle l'orifice comporte des languettes sur un seul côté. Elles sont retenues alternativement sur chaque côté des orifices étampés le long d'une nervure.

The invention will be better understood from the detailed description which follows and which refers to the appended drawings which are given as non-limiting examples, namely:

• the figure 1 represents a crimp according to the invention at an intersection between a stiffener and a rib of the grid sheet.
• the figure 2a shows a schematic view of the tongues crimping rectified on each side of the orifice.
• the figure 2b shows the tabs of the figure 2a folded on each side of the hole.
• the Figure 2c illustrates the position of the tongues and the effect of the stops when pressure is exerted on the grid sheet.
• the figure 2d illustrates an example of opposite tabs folded each having a recess arranged staggered with respect to each other.
• the figure 3a is a front view of the end of a stamp for cutting the tabs and form the hole that the tabs through to achieve the crimping.
• the figure 3b shows a top view of the end of the stamp of the figure 3a
• the figure 3c shows an orifice as it would be machined in a fixed support with a contour corresponding to that of a section of the stamp.
• the figure 4 illustrates schematically in a sectional view of a stiffener the step of folding the tabs stamped against the inner face of a stiffener.
• the figure 5 schematically illustrates the result obtained after folding of the tabs against the inner face of the stiffener.
• the figure 6 schematically illustrates a variant of crimping in which the orifice has tabs on one side. They are held alternately on each side of the orifices stamped along a rib.

detailed description

A formwork panel (1) comprises a mesh metal sheet (2) extending over a plurality of stiffeners (3) arranged parallel to one another at regular intervals preferably. The grid sheet (2) has a plurality of parallel ribs (4) crossing the stiffeners (3), perpendicular preferably, and also arranged at regular intervals on the surface of the sheet (2). The grid sheet (2) is preferably crimped at each intersection between the ribs (4) and the stiffeners (3) in order to minimize the deformations due to the pressure of the concrete and ensure optimum fixation.

The stiffeners (3) consist of profiled steel bars generally U-shaped as shown in sectional views of figure 4 and 5 . The mesh sheet (2) is applied against the lower sides of the U-shaped sections and held by the ribs (4) at each crossing with these profiles. According to a preferred embodiment, the ribs (4) are also U-shaped with the flat bottom portion placed on the stiffeners (3).

The screen (2) is made by a known method, by stretching or deployment of a punched steel sheet with a plurality of blades. The ribs (4) are formed by stamping at predefined intervals of the sheet prior to deployment. They thus constitute integral parts of the screen sheet (2) without being reported on the screen as additional parts. In a practical embodiment the width of the U ribs (4) is 1.5 to 2.5 cm with a width of U stiffeners (3) of about 5 cm.

The profile of the ribs (4) may have a different shape without a flat portion applied against the stiffener such as V-shaped where the edge is placed on the stiffener (3). In this case, the crimping operation locally deforms the rib (4) so as to flatten it in the vicinity of the tongues (6). This deformation is considered acceptable both in terms of the strength of the crimping and the surface of the panel where the concrete coating compensates for irregularities.

The figure 1 shows an enlarged view of a preferred example of crimping according to the invention at the intersection of a rib (4) and a stiffener (3) seen from its inner face to the bottom of the U-shaped section. The perpendicularly crossing rib the stiffener is supported on the outer face of the U-shaped section. The stiffener (3) and the rib (4) comprise an orifice (5) traversed by tabs (6, 6 ') resulting from stamping performed at once. in the rib (4) and the stiffener. The tabs (6, 6 ') are bent, for example, on two opposite edges of the orifice (8) towards the inside of the U-shaped section as shown in FIG. figure 2a , the tabs (6) issuing from the rib (4) passing through the orifice (5). They each comprise a part of a given width (5.6 mm in one embodiment) whose end is attached to the rib (4), respectively to the stiffener (3) and a wider part (8 mm for example) having one end free.

The contour of the junction of the narrow part and the wider part of a tongue (6, 6 ') forms two stops (7, 7') symmetrical preferably placed one facing the other. These stops (7, 7 ') have a contour preferably forming a right angle and are located at a predetermined distance from one end of the tongue (6, 6'), for example about 5 mm from the end free of the tongue (6, 6 '). Each abutment (7, 7 ') of width 1.2 mm in the example plays a role of locking the tongue (6) issuing from the rib (4) once bent over the edge (8) of the orifice (5). Indeed, the width of the orifice (5) in the vicinity of the attached end of the tongue (6) is less than the width of said orifice (5) near its center. This difference in width constituting the abutments (7) makes it possible to prevent the tabs (6) issuing from the rib (4) from leaving the orifice (5) from being pressed against the mesh sheet (2).

It should be noted that other forms of orifice and corresponding tabs whose contour comprises one or more recesses forming one or more abutments arranged symmetrically or not are also possible provided that their role of locking is maintained.

The figure 2a shows a first crimping option in which the respective tabs (6, 6 ') issuing from the stiffener (3) and the rib (4) are bent substantially at right angles to the plane of the orifice (5). A crimp of this type has a clearance equivalent to the distance separating the attached end of the tongue (6) and the stops (7) (about 5 mm according to the example). Internal pressure P due to the filling concrete on the grid sheet (2) will advance the grid sheet (2) relative to the stiffeners (3) leaving a space equivalent to the clearance between the stiffeners (3) and the ribs (4) . This movement remains limited to the game thanks to the stops (7) of the tongues (6) which prevent the release of these out of their orifices (5) corresponding. When the distance between the attached end of the tongue and the stops corresponds to the thickness of the metal of the stiffener, play is reduced to a minimum.

According to a second option, the tongues (6, 6 ') are folded against the internal face of the stiffener (3) at the bottom of the U-section using a suitable tool. The figure 2b shows a crimping in which the two tabs (6, 6 ') of the stiffener (3) and the rib (4) are folded symmetrically along their ends attached to the edge (8) of the orifice (5) so as to apply against the face of the stiffener (3) on two opposite sides of the orifice (5) (arrows R). This type of crimping provides better resistance of the mesh (2) on the stiffeners (3) leaving no clearance between the ribs (4) and the stiffeners (3) as presented in the first option.

The Figure 2c shows the behavior of a crimped tab (6, 6 ') folded as shown in FIG. figure 2b when pressure forces P are exerted on the grid sheet (2). The pressure P causes the tongues (6) coming from the rib (4) to be straightened so as to form an angle close to 90 degrees with the plane of the orifice (5) or that of the internal face of the stiffener profile (3). ), the tabs (6 ') from the stiffener (3) remaining folded. The abutments (7) rest on the inner face of the stiffener (3) at the edge (8) of the narrow portion of the orifice (5) preventing the exit of the tongue (6). As in the option of figure 2a , the mesh sheet (2) or more precisely the rib (4) away from the stiffener (3) at a distance corresponding to the maximum length of the narrow portion of the tongue (6). The stall removal problem (2) proper crimping tabs of constant width over their entire length as described in document W02007 / 079989 is thus solved by stops (7) acting as locking.

The example of figure 2d shows tabs each having a recess acting as a stop. The staggered arrangement of the recesses avoids a torsion effect of the rib at the crimping under the effect of pressure forces. The asymmetrical shape of the orifice (5) corresponds to the shape of each of the tongues. The preferred configuration of the crimping corresponds to that comprising symmetrical tongues with two recesses forming two abutments one facing each other as represented by the figures 1 , 2a, 2b and 2c .

The advantage of the crimping is that it can be done quickly with a suitable machine tool allowing at first time to stamp the rib (4) and the stiffener (3) and in a second time fold respectively the tabs (6) of the rib (4) and the tongues (6 ') of the stiffener (3) in the orifice (5) of the stiffener (3). In order to maintain a precise alignment of the tongues (6) with the corresponding holes (5), stamping and bending operations of the tongues (6, 6 ') are performed simultaneously when the ribs (4) and the stiffeners (3) are kept in their final position on the machine.

According to one variant, the orifices (5) of the stiffeners (3) can be stamped during a preliminary stage. In this case, only the tabs (6) from the ribs are folded towards the inner face of the profile of the stiffener (3) during crimping. This variant requires a prior positioning of the stiffeners (3) and an alignment of the orifices (5) accurate with respect to the ribs (4) of the mesh (2) so as to stamp and fold the tongues (6) under optimal conditions.

The invention also relates to a crimping tool of a plurality of stiffeners (3) to a grid sheet (2) having a plurality of ribs (4) forming a panel (1) formwork comprising a stamp (9) and a support (14) capable of forming an orifice (5) and two tabs (6) at an intersection between a rib (4) and a stiffener (3) having a first portion with an end attached to the rib (4) and a free end characterized in that the end of the die (9) forms a symmetrical tip with a central edge (12) and two pairs of lateral edges (13) inclined perpendicular to the central edge (12) and in that the section comprises a central portion of greater width than the width of the parts located on either side of the central part, said stamp (9) and said support (14) being able to create two opposite symmetrical tongues (6) having in the vicinity the end attached to the rib (4), a first portion of width less than the width of a second portion in the vicinity of the free end, the contour of the two parts forming at their junction two abutments (7) located one opposite the other at a predetermined distance from one end of the tongue (6).

The stamping of tabs (6, 6 ') and the orifice (5) as illustrated by the Figures 2a to 2c is performed with tools comprising a stamp (9) and a support (14) as represented by the Figures 3a to 3c . The section of the stamp (9) has a shape corresponding to that of the orifice (5) with a part near the center wider than the parts located on either side of said center. The end forms a tip with a central sharp edge (12) for creating the free ends of each tongue (6, 6 '). The cutting of the rest of the contour of the tongues (6) with the stops (7) is performed by two pairs of sharp edges (13) sideways inclined perpendicularly to each side of the central edge (12).

The figure 3b shows a top view of the tip of the stamp (9) with the central ridge (12) passing through the wide part of the section. During the crimping operation, the stamp (9) first passes through the metal of the rib (4) then that of the stiffener (3) while cutting in a single operation the tongues (6, 6 ') and the orifice (5) both in the rib (4) and in the stiffener (3).

The support (14) illustrated by the figure 3c having a window (15) similar to the orifice (5) created by the stamp (9) is placed against the inner face of the stiffener (3) facing the stamp (9) so as to slide it after having formed the tabs (6, 6 ') in the metal of the rib (4) and the stiffener (4). In addition, the window (15) of the support (14) has a depth dimensioned so as to position the tabs (6, 6 ') perpendicular to the plane of the window (15). In order to obtain a tighter crimp, the tabs (6, 6 ') are then folded against the inner face of the stiffener profile (3) with a suitable tool after removal of the stamp (9) and the support (14). .

The figure 4 shows a schematic form of a stamping tool (9) for making an orifice (5) both through the rib (4) and the stiffener (3) while forming tabs opposite to one another with respect to the other with each end attached to the edge (8) of the two opposite sides of the orifice (5) and a free end.

In a second optional step, the tongues (6, 6 ') directed towards the inner face of the stiffener profile (3) are folded against this face by means of a crimping tool (16) from the underside of the panel (1). A support portion of the not shown die acting after removal of the stamp presses the rib (4) on an area adjacent the orifice (5) to maintain the rib assembly (4) stiffener (3) when the folding tool (16) folds the tabs (6, 6 '). This tool (16) has a shaped end dimensioned and adapted to bend the tabs (6, 6 ') against the inner face of the stiffener (3) as illustrated by the figure 5 .

According to a variant, the end of this tool (16) of folding can deviate as it advances to completely flatten the tabs (6, 6 ') against the stiffener (3).

It should be noted that crimping according to the invention can be performed with a single tongue (6, 6 ') when for example the width of the U of the stiffener is insufficient to contain two tabs (6, 6') symmetrical opposite and folded down share and other of the orifice (5). In this case, the outline of the orifice (5) corresponds to the contour of a tongue (6) with two parts of different width as represented by the figures 1 , 2a, 2b and 2c considering only half left or right of the axis of symmetry A. The stamp (9) also adapted to form a tongue, has an asymmetrical tip whose shape corresponds to the left half or the half right with respect to the axis of symmetry A of the point represented by the Figures 3a and 3b . The window (15) of the support (14) naturally has a shape corresponding to one of the halves with respect to the axis A of the form illustrated by the figure 3c .

The figure 6 illustrates an example of crimping with a single tongue (6, 6 ') per orifice (5). In order to prevent the mesh sheet (2) from stalling by a shifting movement of the stiffeners (3), the stamping of the tongues (6, 6 ') is carried out so that they are retained alternately on the straight sides and left ports (5) aligned along the same rib (4). In addition, the tongues (6, 6 ') can also be alternately attached to the right and left sides of each orifice (5) along each stiffener (3). They thus have a staggered configuration on all the intersections between the ribs (4) and the stiffeners (3) of the panel (1)

The manufacture of a panel (1) is performed by a machine on which the grid sheet (2) is held temporarily flat on stiffeners (3) by means of clamping devices.

The stamping and folding steps of the tongues (6, 6 ') are generally performed simultaneously on a plurality of intersections between at least one rib (4) and stiffeners (3) by a plurality of stamping tools. (9) and drawdown (16). These tools, aligned on at least one support parallel to the ribs (4) and arranged opposite said intersections advance along the interval between the ribs (4) in order to crimp the mesh sheet (2) at each crossing of the ribs (4) with the stiffeners (3).

The present invention also relates to a formwork comprising two panels (1), as described above, placed facing each other and connected by connecting elements articulated to the panels by means of the stiffeners (3). .

These connecting elements to maintain the panels (1), either at a gap defining a gap for receiving concrete or similar material, or folded for storage and transport.

The wall erected with integrated formwork as described above is also an object of the present invention. The gap between the two panels (1) is filled with concrete or similar material.

A concrete slab made with a panel (1) described above is also an object of the present invention. The slab is made by placing the panel (1) generally horizontally with the face having the stiffeners (3) directed upwards. Reinforcing reinforcements are generally placed on the stiffeners before pouring a layer of concrete preferably uniform on this face. The quantity of reinforcement and the thickness of the concrete layer are determined according to the slab range, the loads, the concrete quality, etc.

Claims (15)

Panel (1) for formwork of concrete walls or slabs comprising a mesh metal sheet (2) reinforced on the one hand by a plurality of stiffeners (3) formed of profiled rigid metal bars arranged parallel to one another and spaced apart at predefined intervals, and secondly by ribs (4) integrated in the mesh of the sheet (2) spaced at predetermined intervals and crossing the stiffeners (3), the mesh sheet (2) being fixed on the stiffeners (3) by crimping at at least one intersection between a rib (4) and a stiffener (3) so that at least one metal portion of the rib (4) forming a tongue (6) having one end attached to the rib and a free end, holds the stiffener (3) through an orifice (5) of said stiffener (3), the orifice having a shape corresponding to the shape of the tongue, said panel ( 1) is characterized in that the tongue (6) has, in the vicinity of the end attached to the rib (4), a first part of width less than the width of a second part in the vicinity of the free end, the outline of the two parts forming at their junction at least one recess at a predetermined distance from one end of the tongue, said recess forming a stop (7) preventing the release of the tongue (6) out of the corresponding orifice (5) under the effect of pressure forces exerted on the wire mesh sheet (2). Panel according to claim 1, characterized in that the stiffeners (3) consist of U-shaped profiled bars whose lower sides are applied against one side of the grid sheet (2), said stiffeners (3) being arranged at intervals on the grid sheet (2) and perpendicular to the ribs (4) of said sheet. Panel according to claims 1 or 2, characterized in that the profile of the ribs (4) comprises a flat portion applied against the stiffeners (3). Panel according to claim 3, characterized in that at at least one intersection with a stiffener (3) the ribs (4) are crimped so that a tongue (6), issuing from said rib (4), passes through the corresponding orifice (5) of the stiffener (4) and is folded against the inner face of the U-shaped section of the stiffener (3) at edge (8) of said orifice (5) so as to bear against the internal face of the stiffener (3). Panel according to claim 4, characterized in that the tongues (6) are alternately attached to the right and left sides of the orifices (5) aligned along the same rib (4). Panel according to claim 5, characterized in that the tabs (6) are alternately attached to the right and left sides of each opening (5) along each stiffener (3). Panel according to claims 1 to 6, characterized in that the crimping of a rib (4) to a stiffener (3) comprises two tabs (6) opposite one another, the recess of a tongue being arranged in staggered relation to the recess of the other tongue. Panel according to claims 1 to 6, characterized in that the crimping of a rib (4) to a stiffener (3) comprises two tabs (6) opposite symmetrical with respect to each other, the contour of each tab having two recesses located one next to the other. Panel according to claims 1 to 8, characterized in that the crimping of a rib (4) to a stiffener (3) has two tabs (6, 6 ') opposite to each other at the same time the stiffener (3) and the rib (4), the tongues (6) issuing from the rib passing through the corresponding orifice (5) and the tongues (6 ') issuing from the stiffener (3) are substantially perpendicular to the plane of the orifice, the stops (7) of the tongues (6) of the rib (4) preventing their release from the orifice. Panel according to claims 1 to 8, characterized in that the crimping of a rib (4) to a stiffener (3) comprises two symmetrical tabs (6, 6 ') opposite to one another at the two times the stiffener (3) and the rib (4), the tabs (6) from the rib through the corresponding orifice (5) and the tongues (6 ') from the stiffener (3) are each folded against the face internal of the stiffener (3) at the edge (8) of opposite sides of the orifice (5) so as to bear against the internal face of the stiffener (3) Formwork characterized in that it comprises two panels (1), according to any one of claims 1 to 10, placed facing each other and connected by articulated connecting members audits panels (1) by the intermediate stiffeners (3), these connecting elements to maintain the panels (1), either at a gap defining a gap for receiving concrete or similar material, or folded for storage and transport. Wall characterized in that it comprises an integrated formwork according to claim 11, the gap separating the two panels (1) being filled with concrete or similar material. Slab characterized in that it comprises an integrated panel (1) according to any one of claims 1 to 10, placed generally horizontally with the face comprising the upwardly facing stiffeners (3), reinforcing reinforcements and a layer concrete or similar material are deposited on said face. Tooling for crimping a plurality of stiffeners (3) to a grid sheet (2) having a plurality of ribs (4) forming a shuttering panel (1) comprising a stamp (9) and a support (14) adapted to form an orifice (5) and two tongues (6, 6 ') at an intersection between a rib (4) and a stiffener (3) having a first portion with an end attached to the rib (4) and a free end characterized in that that the end of the die (9) forms a symmetrical tip with a central edge (12) and two pairs of lateral edges (13) inclined perpendicular to the central edge (12) and in that the section comprises a central portion of greater width than the width of the parts located on either side of the central part, said stamp (9) and said support (14) being able to create two opposite symmetrical tongues (6, 6 ') comprising in the vicinity of the end attached to the rib, a first part of the less than the width of a second portion in the vicinity of the free end, the contour of the two parts forming at their junction two recesses forming two abutments (7) located one opposite the other at a predetermined distance from one end of the tongue (6, 6 '). Tooling according to claim 14, characterized in that the support (14) has a window (15) having a contour corresponding to the contour of the section of the stamp (9) and a depth adapted to position the tongues (6, 6 ') stamped perpendicularly to the plane of the window (15).

Images