Metal Profile Member To Be Used As A Formwork Assisting In The Construction of Metal/Concrete Flooring

Abstract

The invention relates to a formwork ribbed metal profile member assisting in the construction of metal/concrete flooring, including longitudinal edges (2, 3) defining upper (4) and lower (5) areas connected by webs (6) and comprising recessed deformations, characterized in that at least a portion of each web comprises a recessed deformation (60) defined by a continuous line which extends parallel to the longitudinal direction of the profile member, and the length of which is greater than that of said portion of the web in said longitudinal direction.

Description

The invention relates to a metal profile intended to be used as participating formwork for the construction of metal/concrete floors.

As is known, formwork that acts both as the formwork and as the reinforcement is known as participating formwork. When it is used to create a reinforced-concrete floor, this formwork is therefore left in situ as reinforcement and contributes to the in-service strength of the floor.

Numerous types of participating formwork are already known. These conventionally come in the form of a metal sheet that is bent so that it has a series of substantially parallel ribs that run longitudinally. Thus, in cross section, the sheet comprises undulations, generally of a trapezoidal appearance.

Such formwork is intended to be positioned between two supports, such as bearing walls, resting on them at its ends. Concrete is then poured onto the formwork in the direction of the ribs. After drying, a series of supporting girders is formed, these girders running longitudinally.

Throughout the description, the term concrete can be considered to cover any type of binder likely to be used in the construction of flooring.

When it is in service, the floor is subjected to forces which tend to cause relative slippage between the concrete and the formwork and therefore to cause them to separate.

The ribs of the formwork provide anchorage in the transverse direction.

To provide anchorage in the longitudinal direction, it is known practice to form embossed or pressed features on the ribs. These features constitute longitudinal points of anchorage between the formwork and the concrete and therefore limit their relative slippage. Specifically, when relative slippage occurs, these embossed features resist the slippage by deforming.

However, known formwork has its limits. Thus, the span of the floors is generally 4 meters and the maximum loading that the floor can bear is of the order of 250 kg/m².

These limits are nowadays insufficient.

It is therefore an object of the present invention to propose a metal profile of the participating formwork type that makes it possible to obtain floors that are stronger and can span a longer distance.

This profile can thus be used with a smaller amount of concrete than conventional floors, for the same strength.

It is another object of the invention to propose a metal profile to which clamps or braces can be attached for securing elements of the false ceiling.

The invention relates to a ribbed metal profile of the participating formwork type for constructing steel/concrete floors, comprising longitudinal corners delimiting upper and lower regions connected by webs and comprising reentrant deformations, characterized in that at least part of each web comprises a reentrant deformation delimited by a continuous line running parallel to the longitudinal direction of the profile and the length of which exceeds that of said part of the web in this longitudinal direction.

For preference, said deformation extends over the entire length of the web.

The profile may also further comprise at least one reentrant deformation in at least part of the upper and/or of the lower regions, which deformation is delimited by a continuous line the length of which is greater than said part of the upper and/or lower regions.

For preference, said deformation extends over the entire length of the upper and/or lower regions.

The continuous line may be broken, symmetric or otherwise, for example crenellation(s).

The continuous line may also adopt the form of a sinusoid.

In one embodiment of the profile, in the webs, the lower regions and/or the upper regions, the reentrant deformations are present in pairs and symmetrically.

The profile may comprise stiffeners in the webs and/or the upper regions.

The profile may also comprise bends in the lower regions.

Advantageously, the profile comprises, in its webs, a protruding bulge that runs longitudinally.

The invention also relates to a method for obtaining a metal profile according to the invention, comprising the following steps:

• (a) flattening a metal sheet of set thickness,
• (b) producing, in the longitudinal direction of the metal sheet, two reentrant deformations delimited by a line that is continuous and of which the projection in the plane of the metal sheet is in two dimensions, symmetrically with respect to a longitudinal central line of the metal sheet, and over at least part of the length of the sheet,
• (c) repeating step (b), the deformations being, each time step (b) is performed anew, further away from said central line than the previous time it was performed,
• (d) deforming the profile to obtain substantially parallel longitudinal ribs or half-ribs, in which at least said webs have said deformations.

The method may comprise an additional step in which grooves are produced between two implementations of step (b), these grooves, after step (d), constituting stiffeners.

The method may also comprise a step of forming longitudinal and protruding bulges which are produced after implementation of step (b), at the deformations intended to be present in the webs.

Step (c) may allow the production of reentrant deformations in said webs, on the upper regions and/or on the lower regions of said ribs.

The method may also comprise, after step (d), a step consisting in producing stiffeners on the upper and/or lower regions of the ribs.

The method may also consist in producing, before or after step (d), at least one bend on the lower regions of the profile.

The invention relates to a machine for manufacturing a profile according to the invention, this machine being equipped with at least one pair of rollers of the toothed wheel type, each tooth upsetting metal to form a reentrant deformation.

The invention also relates to the application of the profile according to the invention to the production of a participating-formwork floor.

The invention relates to a participating-formwork floor obtained with a profile according to the invention, in which at least one brace is arranged in a cavity of the profile, bearing against the protruding bulges.

The invention will be better understood and other objects, advantages and features thereof will become more clearly apparent from reading the following description which is given with reference to the attached drawings in which:

FIG. 1 is a perspective view of a portion of a metal profile according to the invention,

FIG. 2 is a view in section on II-II of FIG. 1,

FIG. 3 is a view in cross section of one example of a metal profile according to the invention comprising braces;

FIG. 4 illustrates a metal sheet on which the first steps of the method according to the invention have been performed;

FIG. 5 illustrates the metal profile of the invention, obtained from the sheet illustrated in FIG. 4, after the last step in the method according to the invention has been carried out;

FIG. 6 illustrates another example of a metal sheet on which the first steps of the method according to the invention have been performed;

FIG. 7 illustrates a profile according to the invention obtained from a sheet illustrated in FIG. 6, after the last step in the method according to the invention has been performed;

FIG. 8 illustrates an example of tooling used for implementing the method according to the invention; and

FIG. 9 is a perspective view illustrating one example of a brace.

The elements that are common to the various figures will be denoted by the same references.

FIGS. 1 and 2 illustrate the same portion of a profile according to the invention.

This metal profile is ribbed, which means that it has a series of substantially parallel ribs running longitudinally. FIGS. 1 and 2 illustrate one of these ribs 1.

When the profile is used to create a floor, concrete is poured between the ribs in such a way that the cavity 10 defined by the rib is free of concrete.

Thus, the profile comprises longitudinal corners, upper corners 2 and lower corners 3. These corners between them delimit zones known as regions, upper regions 4 and lower regions 5.

In practice, these regions will be parallel to the floor of which the metal profile will form the formwork.

These corners also delimit webs 6 which extend between the upper regions 4 and the lower regions 5.

In the example illustrated in FIGS. 1 and 2, these webs run obliquely, such that the transverse width of the cavity 10, at the lower regions 5 is greater than that of the upper region. This then is a profile called an “open” profile, which is stackable. The invention is not restricted to this embodiment and also covers profiles known as “closed” profiles, which are not stackable. The webs could also run perpendicularly between the upper and lower regions.

The profile according to the invention comprises, in each web 6, a reentrant deformation 60 which is produced substantially in the lower zone of the webs. Reentrant deformation is understood to mean a deformation which displaces the sheet metal of the profile toward the inside of the cavity 10. These deformations are delimited by a continuous line which, in the embodiment illustrated, runs in a middle zone of the web and which has a crenellated shape. The crenellation illustrated in FIG. 1 has an oblique shape, which means that the segments 62 connecting the segments 61 which run in the longitudinal direction are oblique and not perpendicular to these segments 61. Of course other shapes could be chosen for these reentrant deformations made in the webs 6 of the profile.

In general, it is appropriate for the line delimiting these deformations to have a continuous shape, for this to extend over at least part of the web and for this line, in the plane of the web, to be in two dimensions. That means that the reentrant deformation formed in a web cannot be a simple longitudinal line or a line perpendicular to this longitudinal line, for example connecting the upper and lower regions 4, 5.

In other words, the developed length of the line delimiting the deformation is greater than the part of the web on which the deformation is produced.

As illustrated for example in FIG. 1, the deformation 60 produced in the web 6 creates, on the inside of this web, two parts delimited by the crenellated shape and transversely separated from one another by the depth of the deformation produced.

In the figures, that part of the web that lies in the continuation of the upper region 4, known as the “upper part” is referenced 63, whereas that part of the web that is offset transversely toward the inside of the profile is referenced 64.

These two parts are substantially parallel and are joined together by a wall 65 which is substantially perpendicular to the parts 63 and 64. The depth of the deformation corresponds more or less to the height of this wall which has the form of a continuous three-dimensional crenellation.

FIGS. 1 and 2 shows that the upper part 63 of the web 6 has a bulge 66 which runs longitudinally above the segments 61 closest to the upper region 4 and which is continuous. This bulge constitutes a projecting or protruding deformation, which means a deformation which displaces the sheet metal of the profile toward the outside of the cavity 10. The benefit of this bulge will be described later on in the description. It can be omitted.

The line delimiting the deformation 60 may therefore be defined as the one that forms the intersection between the part 63 and the wall 65. It is therefore in two dimensions in the plane of the part 63, here referred to as the “plane of the web”.

This line can be located at any level along the web. However, for preference, it is not situated on the top corners 2. This is because any deformation of the profile at the top corners considerably reduces its strength and is to be avoided.

Moreover, FIGS. 1 and 2 show a profile comprising a single reentrant deformation in each web. Other profiles could have two, or even three reentrant deformations.

These reentrant deformations could alternately adopt the form of oblique asymmetric crenellations or of straight symmetric or asymmetric crenellations or even the shape of a sinusoid.

As will be explained in the description of the method according to the invention, this continuous two-dimensional line makes it possible, when the sheet metal is being deformed, for metal to be displaced across the width of the sheet. This displacement of the metal limits the thinning of the sheet at the point of deformation and therefore makes it possible to create deformations of a greater depth than can be achieved with known metal profiles.

In the example illustrated in FIGS. 1 and 2, the metal profile according to the invention comprises, in its lower 5 and upper 4 regions, deformations 50 or 50, and 40, 41. In this example, these reentrant deformations also have the shape of oblique crenellations, like the deformations 60 provided on the webs 6.

In the example illustrated in FIG. 1, the deformations 40 and 41 are symmetric about a longitudinal line 42 passing through the center of the upper region 4.

Likewise, when two deformations 50, 51 are made in a lower region, these are symmetric about a longitudinal line passing through the center of each lower region.

Asymmetric deformations could be provided.

The profile according to the invention could have just one deformation or could even have three deformations in the upper and lower regions.

The figures also show that grooves are made in the profile, both in the webs 6 and in the upper region 4, to produce stiffeners 67, 43, 44. These are reentrant deformations.

In the conventional way, the purpose of these stiffeners is to enhance the mechanical strength of the profile according to the invention.

Reference is now made to FIG. 3 which illustrates a profile according to the invention of the kind illustrated in FIGS. 1 and 2 and which comprises a central rib 30 flanked by two half-ribs 31 and 32. FIG. 3 shows that inside the cavity 38 defined by the rib 30 there may be a brace 33 which bears against the upper zone 650 of the walls 65 and on the bulges 66 which are of significant depth.

Likewise, a brace 37 is provided in the cavity 38 defined by the half-rib 32.

The upper zone 650 of the walls 65 is an oblique wall, facing toward the inside of the rib 30 with respect to the upper part 63 of the web 6, and they are therefore each able to accommodate the end of a brace 33, 37 in the form of an arched buttress.

The bulge 66 present between the upper part of the web and the upper zone 650 creates a space making it easier to fit a brace and increasing the brace bearing area.

In the conventional way, this brace can be used for attaching elements of the false ceiling, once the floor has been created using the profiles according to the invention as formwork. These elements may notably be pipes or cables.

That avoids the need to drill into the profile in order to attach the elements and therefore likewise avoids weakening the profile.

Furthermore, the weight of the suspended elements tends to pull the brace downward. The brace therefore exerts a lateral thrust toward the outside of the cavity, reinforcing the cohesion between the profile and the concrete poured into the profile.

The braces have screwthreads 330, 370 intended to accept screws for attaching these elements. These screwthreads protrude from the surface of the brace 33 and are within the thickness of the brace 37.

FIG. 9 illustrates one example of a brace 39, with screwthreads 390, which brace can be positioned in the cavity of a profile according to the invention.

Reference is now made to FIGS. 4 and 5 which illustrate steps in one example of how to implement the method according to the invention.

This method first of all consists in flattening a metal sheet of set thickness of between 0.6 and 2 mm.

The next step involves producing two reentrant deformations 60, one on each side of a longitudinal and central line 52 of the sheet. These deformations are similar to those illustrated in FIGS. 1 and 2.

In a second step, two deformations 40, 41 are then made, these deformations likewise being arranged symmetrically about the longitudinal line 52, but further away from this line than the deformations 60 produced in the first step. These deformations are similar to those illustrated in FIGS. 1 and 2.

The bulge 66 is then produced at each deformation 60. It is a projecting or protruding deformation so that it enlarges the cavity defined by each rib, in the finished profile.

In a later step, grooves 67 and 43, 44 are made in the sheet. In practice, these grooves will form the stiffeners illustrated in FIG. 2 in particular. They are reentrant like the deformations 60, 40 and 41.

Furthermore, the stiffeners 67 need to be produced while the metal sheet is still flat. However, the grooves 43, 44 could be produced after the profile has been bent into shape to obtain the ribs.

In the example illustrated in FIG. 4, between the two deformations 60 there are also made folds 53, in the opposite direction to the stiffeners. These are therefore projecting or protruding deformations, like the bulges 66.

The final step in the method is to deform the profile in order to obtain substantially parallel longitudinal ribs.

In the example illustrated in FIG. 5, the profile obtained comprises two half-ribs 31a and 32a the webs 6 of which have deformations 60.

Thus, the lower region 5 of the profile is centered on the central longitudinal line 52 of the sheet and the deformations 60 are situated in the webs 6 of the half-ribs 31a an 32a and the deformations 40, 41 are situated in the their upper region 4.

FIGS. 6 and 7 illustrate another example of how to carry out the method according to the invention.

Thus, starting out from a metal sheet of set thickness in the flat state, the method here consists in producing, symmetrically about a longitudinal central line 52 of the sheet, two reentrant deformations 50 and 51. After this first step, deformations 60 are produced in the sheet, symmetrically about the line 52, but separated from this line.

Once these deformations have been produced, the later step in the method consists in producing deformations 40, 41. These deformations are also symmetric about the central line 52 and are further away therefrom than are the deformations 60.

All the deformations 40, 41, 50, 51 and 60 are similar to those illustrated in FIGS. 1 and 2.

As described previously with reference to FIGS. 4 and 5, bulges 66 and grooves 67 and 43, 44 are also produced in the sheet.

The last step in the method is to deform the sheet in order to obtain the two half-ribs 31b and 32b.

As illustrated by FIG. 7, the deformations 50 and 51 are situated in the lower region 5 of the profile. Moreover, the deformations 60 are situated in the webs of the profile while the deformations 40, 41 are situated in the upper regions 4 of the profile.

The width of metal sheet used depends on the number of ribs and on the height of the profile that is to be obtained.

It has been observed that each reentrant deformation corresponds to a metal sheet width reduction of between around 1 and 1.5 mm. Thus, in the example illustrated in FIGS. 4 and 5, the profile produced from a metal sheet with a starting width of 400 mm, has a width of around 395 mm.

FIG. 8 illustrates tooling that can be used to obtain the crenellated deformations illustrated in the various figures.

This tooling is made up of two pairs of rollers 70, 71 and 72, 73 capable of rotating in opposite directions and between which the sheet that is to be deformed can be fed.

As FIG. 8 illustrates, within each pair, one roller 70, 72 has a profile 700, 720 which complements that 710, 730 borne by the roller 71, 73 of the other pair, these profiles intermeshing in order, in a metal sheet, to create two symmetric reentrant deformations like the deformations 50 and 51 of FIGS. 6 and 7.

In practice, while the method according to the invention is being implemented, the two pairs of rollers are separated from one another from a central position so as to produce the reentrant deformations, in pairs, and symmetrically about the center of the sheet.

Tests conducted showed that the method according to the invention makes it possible, for a given thickness of sheet metal, to produce deformations the depth of which is greater than the deformations exhibited by known metal profiles.

Thus, the reentrant deformations of a profile according to the invention have a depth greater than 3 mm and which can be as much as 5 mm for a metal sheet around 0.75 mm in thickness. By way of comparison, a conventional profile of the same thickness had deformations obtained by pressing and the depth of which is between around 2 mm and 2.5 mm.

Likewise, the depth of the deformations may be between 6 and 7 mm for a metal sheet 1.5 mm in thickness.

This is because these deformations cause less thinning of the metal, for a given depth. Thus, for similar thinning of the sheet, the deformation obtained using the method according to the invention has a greater depth.

One explanation postulated by the applicant is that in creating the deformations, in successive pairs, symmetrically about a longitudinal central line of the sheet, the metal is displaced in a transverse direction toward this longitudinal central line.

Moreover, the displacing of the metal toward this longitudinal central line is also a by-product of the shape chosen for the deformation. It will be recalled here that the deformation is delimited by a line running longitudinally and continuously and of which the projection in the plane of the sheet (or alternately of the web) is in two dimensions.

Various tests were carried out in order to illustrate this point.

These tests were run on four different metal profiles intended to be used in the construction of flooring.

The profiles considered had just a corrugation and were all filled with concrete, as is done conventionally for producing a steel/concrete floor, so as to obtain a beam.

The first profile (No. 1) is a conventional profile comprising, in its webs, pressed features in the form of oblique segments. Such a profile is notably manufactured by the Bacacier company under reference H60.

The second profile (No. 2) is a profile according to the invention which has reentrant deformations only in its webs (one deformation per web), these deformations being of the type illustrated in FIGS. 1 and 2.

The third profile (No. 3) is also a profile according to the invention, like the one illustrated in FIG. 5, i.e. comprising reentrant deformations both in its webs and in the upper region.

Profiles 1 to 3 also have three longitudinal bends along their lower regions, like those referenced 53 in FIGS. 4 and 5.

All these profiles are made of galvanized sheet steel of type E320, with the same thickness of 0.75 mm.

The tests involved positioning each beam obtained from the four profiles on a press.

This press is a hydraulic press of the Rassant type with a power of 30 metric tons, with a pneumatic ram 125 mm in diameter.

Each beam is positioned centrally in relation to the press ram and rests on each end on two metal blocks.

The press is fitted with a pneumatic pressure gauge marked from 0 to 12 bar, with a manual distributor.

With the pressure gauge reading 0, a comparator is positioned under the beam being tested, in a central position, with its needle pointing to 0.

The results obtained for each of the four beams are summarized in the table below:

	PRESSURE (bar)
BEAM	1	2	3	4	5	6
1	Deformation	0.10 mm	0.30 mm	1.20 mm	2.30 mm	3.60 mm	4.65 mm
							(rupture)
2	Deformation	0	0.25 mm	1.60 mm	3.10 mm	4.60 mm	6 mm
3	Deformation	0	0.20 mm	0.75 mm	1.80 mm	3.25 mm	3.35 mm

These tests first of all demonstrated that the beams obtained with profiles 2 and 3 according to the invention are able to withstand a pressure of 7 bar whereas beam No. 1 breaks at a pressure of 6 bar.

In general, these tests show that the bending and ultimate strength of the profiles according to the invention is greater than those of the conventional profiles.

This is achieved thanks to the depth of the deformations which allows better attachment of the concrete in the transverse direction of the profile.

The profiles according to the invention therefore make it possible to produce floors with a span of over 4 m and which may be as long as 6 m.

The reference signs featured in the claims are there solely to make the latter easier to understand and do not in any way restrict the scope.

Claims

1. A ribbed metal profile of the participating formwork type for constructing steel/concrete floors, comprising longitudinal corners delimiting upper and lower regions connected by webs and comprising reentrant deformations, characterized in that at least part of each web comprises a reentrant deformation delimited by a continuous line running parallel to the longitudinal direction of the profile and the length of which exceeds that of said part of the web in this longitudinal direction.

2. The profile as claimed in claim 1, characterized in that said deformation extends over the entire length of the web.

3. The profile as claimed in claim 1, characterized in that it further comprises at least one reentrant deformation in at least part of the upper and/or of the lower regions, which deformation is delimited by a continuous line the length of which is greater than said part of the upper and/or lower regions.

4. The profile as claimed in claim 3, characterized in that said deformation extends over the entire length of the upper and/or lower regions.

5. The profile as claimed in claim 1, characterized in that said line is broken, symmetric or otherwise, for example crenellation(s).

6. The profile as claimed in claim 1, characterized in that said line is a sinusoid.

7. The profile as claimed in claim 1, characterized in that, in the webs, the lower regions and/or the upper regions, the reentrant deformations are present in pairs and symmetrically.

8. The profile as claimed in claim 1, characterized in that it comprises stiffeners in the webs and/or the upper regions.

9. The profile as claimed in claim 1, characterized in that it comprises bends in the lower regions.

10. The profile as claimed in claim 1, characterized in that it comprises, in its webs, a protruding bulge that runs longitudinally.

11. A method for obtaining a metal profile as claimed in claim 1, comprising the following steps:

(a) flattening a metal sheet of set thickness,

(b) producing, in the longitudinal direction of the metal sheet, two reentrant deformations delimited by a line that is continuous and of which the projection in the plane of the metal sheet is in two dimensions, symmetrically with respect to a longitudinal central line of the metal sheet, and over at least part of the length of the sheet,

(c) repeating step (b), the deformations being, each time step (b) is performed anew, further away from said central line than the previous time it was performed,

(d) deforming the profile to obtain substantially parallel longitudinal ribs or half-ribs, in which at least said webs have said deformations.

12. The method as claimed in claim 11, in which grooves are produced between two implementations of step (b), these grooves, after step (d), constituting stiffeners.

13. The method as claimed in claim 11, characterized in that longitudinal and protruding bulges are produced after implementation of step (b), at the deformations intended to be present in the webs.

14. The method as claimed in claim 11, characterized in that, after step (d), the profile comprises reentrant deformations in its webs, on the upper regions and/or on the lower regions of said ribs.

15. The method as claimed in claim 11, comprising, after step (d), a step consisting in producing stiffeners on the upper and/or lower regions of the ribs.

16. The method as claimed in claim 11 consisting in producing, before or after step (d), at least one bend on the lower regions of the profile.

17. A machine for manufacturing a profile as claimed claim 1, this machine being equipped with at least one pair of rollers of the toothed wheel type, each tooth upsetting metal to form a reentrant deformation.

18. The application of the profile as claimed claim 1 to the production of a participating-formwork floor.

19. A participating-formwork floor obtained with a profile as claimed in claim 10, in which at least one brace is arranged in a cavity of the profile, bearing against the bulges.