Beam for forming a horizontal formwork floor, associated formwork equipment and method

Abstract

A beam (2) for forming a horizontal formwork floor, the beam (2) comprising a lower flange (3), an upper flange (5) configured to support a formwork wall and a stiffening body (4) connecting the lower flange (3) to the upper flange (5), the stiffening body (4) comprising a main cylinder (40) defining, in cross section, a closed belt and at least one auxiliary cylinder (41a, 41b, 41c, 41d) of triangular section connecting the main cylinder (40) to the lower flange (3) or to the upper flange (5). Abstract figure: Figure 7

Description

Title of the invention: Beam for forming a horizontal formwork floor, associated formwork equipment and method Technical field

[0001] The present invention relates to the field of construction, in particular, formwork. The present invention relates more particularly to a beam intended to form a horizontal formwork floor.

[0002] To form a horizontal slab in a building, it is known to pour concrete onto a horizontal formwork floor. With reference to [Fig.l], there is shown by way of example a formwork equipment 110 comprising a horizontal formwork floor P supported by a vertical structure 107 comprising vertical props. The horizontal formwork floor P comprises in a known manner a plurality of beams 101, called "primary beams", which are mounted at the upper ends of the vertical props. The horizontal formwork floor P further comprises a plurality of beams 102, called "secondary beams", which rest on the beams 101. A formwork skin 106, also called "formwork skin", is fixed to the upper surface of the beams 102 so as to form a formwork surface.Typically, the formwork wall 106 is in the form of a wooden plywood sheet that is nailed into an upper surface of the joists 102.

[0003] A beam 102 is a major element of a horizontal formwork floor P. In order to avoid the operator falling through the network of beams 102 when fixing the formwork wall 106, it is preferable to have a large number of beams 102 with a reduced spacing between them (generally less than or equal to 13 cm). The disadvantage of a high number of beams 102 is that it significantly increases the number of times an operator handles beams 102 for the same formwork wall surface 106. To put a beam 102 in place, an operator positioned at the level of the support surface of the vertical props 107 must lift the beam 102 and position it on the beam 101. As a result, the mass of a beam 102 is an important criterion in order to reduce the strain on the operators.One solution to reduce the mass would be to reduce the thickness of the walls of the beam 102 which is generally made of wood or aluminum. Such a reduction in thickness has the disadvantage of affecting the mechanical resistance, in particular, to phenomena of buckling or warping of the slender (thin and elongated) walls of the beam 102.

[0004] It also follows that the number of beams to be installed is an important criterion in order to reduce the arduousness and maintain satisfactory productivity. A solution To reduce the number of beams for a given formwork area, it is best to increase their width. This also reduces the risk of tipping when the operator walks over them, by increasing the stability of the beam.

[0005] Referring to [Fig.2], a cross-sectional view of a first type of beam 102a according to the prior art is shown. The beam 102a comprises a lower flange 130 configured to bear on a beam. The lower flange 130 comprises projecting lateral ends forming connecting tabs 131 with the beam. The beam 102a comprises an upper flange 150 configured to bear on a formwork wall. In this example, the upper flange 150 comprises two separate parts forming between them an upper housing 160 in which a piece of wood 161 is mounted, for example, a cleat. Such a piece of wood 161 makes it possible to fix the formwork wall by nailing it into the piece of wood 161. The mechanical strength of the beam 102a is thus not impacted by the fixing of the formwork wall.The lower sole 130 is connected to the upper sole 150 by a stiffening body 140 defining a closed belt. In this example, the stiffening body 140 comprises a lower horizontal wall 141, formed by the lower sole 130, an upper horizontal wall 142, delimiting the upper housing 160, and two lateral vertical walls 143.

[0006] The vertical side walls 143 are high and must be thick in order to have high mechanical strength to resist buckling forces. Also, such a beam 102a has a high mass, which presents a disadvantage.

[0007] The lateral vertical walls 143 are widely spaced to increase the width of the beam 102a and limit the length of the free edges of the flanges 130, 150. The horizontal walls 141, 142 are thickened to ensure sufficient lateral support of the lateral vertical walls 143.

[0008] To eliminate these drawbacks, with reference to [Fig. 3], a cross-sectional view of a second type of beam 102b according to the prior art is shown. In a similar manner to previously, the beam 102b comprises a lower flange 130 configured to bear on a beam. The lower flange 130 comprises projecting lateral ends forming connection tabs 131 with the beam. In [Fig. 3], the beam 102b comprises a lower flange 130 in two parts. The beam 102b comprises an upper flange 150, similar to that of the first type of beam 102a, configured to bear on a formwork wall.

[0009] Still with reference to [Fig. 3], the lower flange 130 is connected to the upper flange 150 by a stiffening body 140 defining a closed belt. In this example, the stiffening body 140 has a width smaller than the width of the beam 102b so as to reduce its mass. The stiffening body 140 comprises: • a lower horizontal wall 141 spaced from the lower sole 130 by substantially vertical bridges 145, • an upper horizontal wall 142, delimiting the upper housing 160, • two curved side walls 143.

[0010] The curved shape makes it possible to obtain a beam 102b of significant width while limiting the length of the free edges of the soles 130, 150 and the length of the horizontal walls 141, 142, which makes it possible to limit their thickness.

[0011] Such a second type of beam 102b has the advantage of having walls having a smaller thickness than the first type of beam 102a, which reduces its mass. The curved side walls 143 negatively affect the mechanical resistance to buckling forces, in particular, due to their concavity. This disadvantage restricts the possibility of designing beams of great width for a given height and thickness. This would require increasing the concavity of the curved side walls 143, thus making the beam more sensitive to the buckling phenomenon.

[0012] The invention thus aims to eliminate at least some of these drawbacks. PRESENTATION OF THE INVENTION

[0013] The invention relates to a beam for forming a horizontal formwork floor, the beam extending longitudinally along a beam axis, the beam comprising a lower flange, an upper flange configured to support a formwork wall and a stiffening body connecting the lower flange to the upper flange, the stiffening body comprising: • a main cylinder defining, in cross-section, a closed belt and • At least one auxiliary cylinder of triangular section connecting the main cylinder to the lower sole or the upper sole.

[0014] The use of an auxiliary cylinder, that is to say a cylinder of triangular section, makes it possible to form a lattice which reinforces the main cylinder whose shape and section can be reduced to lighten the mass of the beam without affecting its mechanical resistance. The beam is thus simpler to handle for operators. In addition, this makes it possible to design wider and more stable beams without significantly increasing its mass. Safety is thus reinforced while containing the mass.

[0015] According to one aspect, the stiffening body comprises at least one lower auxiliary cylinder connecting the main cylinder to the lower flange and at least one upper auxiliary cylinder connecting the main cylinder to the upper flange. This makes it possible to distribute the reinforcement at each flange.

[0016] According to one aspect, the stiffening body comprises at least two lower auxiliary cylinders connecting the main cylinder to the lower flange. This is explained particularly advantageous when the lower sole has two side parts spaced apart from each other.

[0017] According to one aspect, the stiffening body comprises at least two upper auxiliary cylinders connecting the main cylinder to the upper flange. This is particularly advantageous when the upper flange has two side portions spaced apart from each other.

[0018] According to one aspect, the beam comprises an upper housing configured to receive a piece of wood in order to allow the fixing of the formwork wall to the beam, the upper housing opening onto the upper flange.

[0019] According to one aspect, the main cylinder comprises an upper wall delimiting the upper housing.

[0020] According to one aspect, the main cylinder comprises a lower wall delimiting the lower housing.

[0021] According to one aspect, the upper sole comprises two side portions spaced apart from each other.

[0022] According to one aspect, each side portion of the upper sole is connected to the main cylinder by an upper auxiliary cylinder.

[0023] According to one aspect, the beam comprises a lower housing, the lower housing opening onto the lower flange.

[0024] According to one aspect, the main cylinder comprising corners, at least one auxiliary cylinder is connected to the main cylinder by a corner. According to one aspect, each auxiliary cylinder is connected to the main cylinder by a corner. This results in a beam which is reinforced in a homogeneous manner.

[0025] According to one aspect, the lower sole comprises two lateral parts spaced apart from each other.

[0026] According to one aspect, each side portion of the lower sole is connected to the main cylinder by a lower auxiliary cylinder.

[0027] According to one aspect, the main cylinder comprises two vertical rectilinear side walls. The use of vertical rectilinear side walls makes it possible to increase the buckling resistance. The use of auxiliary cylinders makes it possible to reduce the thickness of the vertical rectilinear side walls.

[0028] In one aspect, each vertical rectilinear side wall having a wall height, the beam having a beam height, the ratio of the wall height to the beam height is between 0.2 and 0.8, preferably between 0.4 and 0.6. This improves buckling resistance while reducing the mass of the main cylinder.

[0029] According to one aspect, the beam has a beam width of between 50mm and 200mm, preferably between 65mm and 130mm.

[0030] In one aspect, the beam having a beam width, the main cylinder has a width smaller than the beam width.

[0031] Also disclosed is formwork equipment comprising a plurality of beams mounted on a vertical structure and a plurality of joists, as previously disclosed, positioned on the beams to form a horizontal formwork floor.

[0032] According to one aspect, the formwork equipment comprises at least one formwork wall fixed to the beams.

[0033] Also presented is a method of assembling formwork equipment as presented previously, the method comprising steps consisting of: • Mounting a plurality of beams on a vertical structure • Position a plurality of joists on the beams to form a horizontal formwork floor. PRESENTATION OF THE FIGURES

[0034] The invention will be better understood on reading the description which follows, given by way of example, and referring to the following figures, given by way of non-limiting examples, in which identical references are given to similar objects.

[0035] [Fig.l] is a schematic representation of formwork equipment according to the prior art.

[0036] [Fig.2] is a schematic representation of a first type of beam according to the prior art in a cross-sectional view.

[0037] [Fig. 3] is a schematic representation of a second type of beam according to the prior art in a cross-sectional view.

[0038] [Fig.4] is a schematic representation of formwork equipment according to one embodiment of the invention.

[0039] [Fig.5] is a schematic representation of a beam arrangement seen from above.

[0040] [Fig.6] is a schematic perspective representation of a beam according to one embodiment of the invention.

[0041] [Fig.7] is a representation of the beam of [Fig.6] in a cross-sectional view.

[0042] [Fig.8] is another representation of the beam of [Fig.6] in a cross-sectional view.

[0043] [Fig.9] is a second embodiment of a beam.

[0044] [Fig. 10] is a third embodiment of a beam.

[0045] It should be noted that the figures set out the invention in detail to illustrate implements the invention, said figures being able of course to serve to better define the invention where appropriate. DETAILED DESCRIPTION OF THE INVENTION

[0046] The invention will be presented for a beam for forming a horizontal formwork floor. With reference to [Fig.4], there is shown schematically a formwork equipment 10 comprising a plurality of beams 1 mounted on a vertical structure 7 and a plurality of beams 2 positioned on the beams 1 to form a horizontal formwork floor P.

[0047] Indeed, as presented previously, the horizontal formwork floor P comprises in a known manner a plurality of beams 1, called "primary beams", which are mounted at the upper ends of a vertical structure 7, for example, a plurality of vertical props. The horizontal formwork floor P further comprises a plurality of beams 2, called "secondary beams", which rest on the beams 1. A formwork wall 6, also called "formwork skin", is fixed to the upper surface of the beams 2 so as to form a formwork surface. As a general rule, the formwork wall 6 is in the form of a wooden plywood plate which is nailed into an upper surface of the beams 2.

[0048] It goes without saying that a beam 2 could be connected directly to a vertical structure 7, for example, to a fork of a prop.

[0049] With reference to [Fig.4], the beams 2 extend parallel to a longitudinal axis while the beams 1 extend parallel to a lateral axis. As illustrated in [Fig.5], the beams 2 are mounted juxtaposed and are mounted adjacent at their ends so as to guarantee an optimal spacing E which corresponds to the width of the beam 2 as will be presented later.

[0050] Beam 2

[0051] The structure of a beam 2 will now be presented with reference to Figures 6 to 8. As illustrated in [Fig.6], the beam 2 extends longitudinally along a beam axis X. Subsequently, the beam 2 will be presented in a reference frame (X, Y, Z) in which the X axis extends longitudinally, the Y axis extends laterally and the Z axis extends vertically. The beam 2 thus has a length L2 defined along the X axis, a width E2 defined along the Y axis and a height H2 defined along the Z axis.

[0052] Preferably, the beam 2 has a beam width E2 of between 50 mm and 200 mm, preferably between 65 mm and 130 mm. Preferably, the beam 2 has a beam length L2 of between 1 m and 6 m, preferably between 1.5 m and 4 m. Preferably, the beam 2 has a beam height H2 of between 50 mm and 300 mm, preferably between between 75mm and 200mm.

[0053] Preferably, the beam 2 is made of metal, in particular aluminum. It goes without saying that it could also be made of plastic. Preferably, the beam 2 has walls having a thickness of between 1.2 mm and 8 mm.

[0054] Still with reference to [Fig.6], the beam 2 comprises a lower flange 3, an upper flange 5 configured to support a formwork wall 6 and a stiffening body 4 connecting the lower flange 3 to the upper flange 5.

[0055] Lower sole 3

[0056] In this embodiment, with reference to [Fig.7], the lower flange 3 comprises two lateral parts 3a, 3b spaced apart from each other. In particular, the beam 2 comprises a lower housing 54 to allow in particular the installation of a clamping or suspension device. The lower housing 54 opens onto the lower flange 3, in particular, between the lateral parts 3a, 3b of the lower flange 3.

[0057] In this example, each lateral part 3a, 3b of the lower flange 3 comprises an external connecting tongue 31 which extends laterally and projects outwards. Such an external connecting tongue 31 makes it possible to ensure an optimal connection to a beam 1 by means of a clamping device. Preferably, the end of each external connecting tongue 31 is thickened so as to reinforce the external longitudinal edges of the beam 2. This makes it possible, on the one hand, to avoid any deformation in the event of the beam 2 falling and, on the other hand, to avoid an overlap of the beams 2 when they are positioned juxtaposed as illustrated in [Fig.5].

[0058] In this example, each lateral part 3a, 3b of the lower sole 3 comprises an internal connection tab 32 which extends laterally in an inward projection. Such an internal connection tab 32 makes it possible to ensure optimal connection of accessories in the lower housing 54.

[0059] It goes without saying that the lower sole 3 could be formed from a single part.

[0060] Upper sole 5

[0061] In this embodiment, with reference to [Fig.7], the upper flange 5 comprises two lateral parts 5c, 5d spaced apart from each other. In particular, the beam 2 comprises an upper housing 51 configured to receive a piece of wood 52 in order to allow the formwork wall 6 to be fixed to the beam 2. The upper housing 51 opens onto the upper flange 5, in particular, between the lateral parts 5c, 5d of the upper flange 5.

[0062] The upper housing 51 opens onto the upper sole 5 via a slot whose width E51 ([Fig.8]) is preferably at least 20 mm in order to allow a easy fixing of the formwork wall 6, in particular, by nailing. Preferably, the upper housing 51 is configured to receive a piece of wood 52 having a height greater than 15 mm.

[0063] In this example, each lateral portion 5c, 5d of the upper flange 5 comprises an external connecting tab 53 which extends laterally and projects outwards. The end of each external connecting tab 53 is thickened so as to reinforce the external longitudinal edges of the beam 2.

[0064] This allows, on the one hand, to avoid impacting its structural integrity in case the beam 2 falls and during lashing during truck transportation, and on the other hand, to avoid an overlap of the beams 2 when they are positioned juxtaposed. The beam 2 thus has a very robust structure.

[0065] It goes without saying that the upper sole 5 could be formed in one piece.

[0066] It goes without saying that a lower sole 3 and / or an upper sole 5 could be integrated directly into the main cylinder 4.

[0067] Rigidification body 4

[0068] According to the invention, with reference to [Fig.7], the stiffening body 4 comprises a main cylinder 40 defining, in cross section, a closed belt. Such a main cylinder 40 makes it possible to mechanically reinforce the beam 2. In this example, the main cylinder 40 has a square section in order to reduce the mass but it could be rectangular.

[0069] In this example, the main cylinder 40 comprises a lower horizontal wall 401, an upper horizontal wall 402 and two vertical rectilinear side walls 403. The use of vertical rectilinear side walls 403 makes it possible to offer better mechanical resistance to buckling forces than a curved wall. The main cylinder 40 comprises walls 401, 402, 403 having a thickness of between 1.2 mm and 8 mm.

[0070] With reference to [Fig.7], the main cylinder 40 comprises an upper wall 402 delimiting the upper housing 51. Similarly, the main cylinder 40 comprises a lower wall 401 delimiting the lower housing 54.

[0071] With reference to [Fig.8], each vertical rectilinear side wall 403 has a wall height H40. The horizontal walls 401, 402 each have a length which corresponds to the width E40 of the main cylinder 40.

[0072] Preferably, the ratio of the wall height H40 to the beam height H2 is between 0.2 and 0.8, preferably between 0.4 and 0.6. Thus, the wall height H40 is low compared to the beam height H2, which makes it possible to significantly reduce the mass while maintaining optimal mechanical strength due to the vertical rectilinear side walls 403. Preferably, the main cylinder 40 has a width E40 smaller than the width of beam E2.

[0073] According to the invention, with reference to [Fig.7], the stiffening body 4 comprises auxiliary cylinders 41a, 41b, 41c, 41d, having a triangular section, connecting the main cylinder 40 to the lower flange 3 and to the upper flange 5. An auxiliary cylinder 41a, 41b, 41c, 41d having a triangular section makes it possible to form a lattice which is optimal for absorbing mechanical forces. The auxiliary cylinders 41a, 41b, 41c, 41d make it possible to reduce the length of the tongues 31, 53 while forming a beam of significant width. By positioning an auxiliary cylinder at each end of the vertical rectilinear side walls 403, this makes it possible to reduce the height of the vertical rectilinear side walls 403 and therefore their sensitivity to buckling without increasing their thickness. As is known, buckling resistance is inversely proportional to the square of the buckling height.

[0074] Preferably, an auxiliary cylinder 41a, 41b, 41c, 41d comprises walls having a thickness of between 1.2 and 8 mm.

[0075] In detail, with reference to [Fig.7], each lateral part 3a, 3b of the lower sole 3 is connected to the main cylinder 40 by a lower auxiliary cylinder 41a, 41b. Similarly, each lateral part 5c, 5d of the upper sole 5 is connected to the main cylinder 40 by an upper auxiliary cylinder 41c, 41d.

[0076] Preferably, the main cylinder 40 comprises four corners and each auxiliary cylinder 41a, 41b, 41c, 41d is connected to the main cylinder 40 by a corner. Preferably, each auxiliary cylinder 41a, 41b, 41c, 41d comprises a wall extending in the extension of a vertical rectilinear side wall 403 so as to reinforce the mechanical structure.

[0077] Thanks to the invention, a beam 2 of reduced mass and improved mechanical resistance is advantageously obtained.

[0078] Referring to [Fig.9], a second embodiment of a beam 2 with different dimensions is shown. Furthermore, the beam 2 comprises stiffening elements along the length X, in particular, ribs 7. In this example, the ribs 7 are formed on the main cylinder 40, in particular, on the lower horizontal wall 401 and on the upper horizontal wall 402.

[0079] With reference to [Fig. 10], a third embodiment of a beam 2 with different dimensions is shown. In this third embodiment, the auxiliary cylinders 41a, 41b, 41c, 41d are connected to the main cylinder 40 indirectly by means of bridges 8.

[0080] Assembly method

[0081] With reference to [Fig.4], an example of implementation of a method for assembling formwork equipment 10 will be presented, the method comprising a step of mounting a plurality of beams 1 on the vertical structure 7. Preferably, the main structure 7 is equipped with forks to support the beams 1. The beams 1 are preferably spaced apart in parallel.

[0082] The method comprises a step of positioning a plurality of beams 2 on the beams 1 to form a horizontal formwork floor P. As illustrated in [Fig.5], the beams 2 are arranged so as to be spaced apart in parallel. In particular, two rows of beams 2 cooperate by their ends which are in contact, without risk of overlapping.

[0083] The method comprises a step consisting of fixing formwork walls 6 on the beams 2, in particular, by nailing.

[0084] Once the horizontal formwork floor P is installed, liquid or pasty concrete can be deposited on the formwork walls in order to form a concrete slab.

Claims

Claims

1. Beam (2) for forming a horizontal formwork floor (P), the beam (2) extending longitudinally along a beam axis (X), the beam (2) comprising a lower flange (3), an upper flange (5) configured to support a formwork wall (6) and a stiffening body (4) connecting the lower flange (3) to the upper flange (5), the stiffening body (4) comprising: • a main cylinder (40) defining, in cross section, a closed belt and • At least one auxiliary cylinder (41a, 41b, 41c, 41d) of triangular section connecting the main cylinder (40) to the lower flange (3) or to the upper flange (5).

2. Beam (2) according to claim 1 wherein the stiffening body (4) comprises at least one lower auxiliary cylinder (41a, 41b) connecting the main cylinder (40) to the lower flange (3) and at least one upper auxiliary cylinder (41c, 41d) connecting the main cylinder (40) to the upper flange (5).

3. Beam (2) according to one of claims 1 to 2 in which the stiffening body (4) comprises at least two lower auxiliary cylinders (41a, 41b) connecting the main cylinder (40) to the lower flange (3).

4. Beam (2) according to one of claims 1 to 3 in which the stiffening body (4) comprises at least two upper auxiliary cylinders (41c, 41d) connecting the main cylinder (40) to the upper flange (5).

5. Beam (2) according to one of claims 1 to 4 comprising an upper housing (51) configured to receive a piece of wood (52) in order to allow the fixing of the formwork wall (6) to the beam (2), the upper housing (51) opening onto the upper flange (5).

6. Beam (2) according to one of claims 1 to 5 in which the upper flange (5) comprises two lateral parts (5c, 5d) spaced apart from each other.

7. Beam (2) according to claim 6 in which each lateral part (5c, 5d) of the upper flange (5) is connected to the main cylinder (40) by an upper auxiliary cylinder (41c, 41d).

8. Beam (2) according to one of claims 1 to 7 wherein, the main cylinder (40) comprising corners, at least one auxiliary cylinder (41a, 41b, 41c, 41d) is connected to the main cylinder (40) by a corner, preferably, each auxiliary cylinder (41a, 41b, 41c, 41d) is connected to the main cylinder (40) by a corner.

9. Beam (2) according to one of claims 1 to 8 in which the main cylinder (40) comprises two vertical rectilinear side walls (403).

10. Beam (2) according to claim 9 in which each vertical rectilinear side wall (403) having a wall height (H40), the beam (2) having a beam height (H2), the ratio of the wall height (H40) to the beam height (H2) is between 0.2 and 0.8, preferably between 0.4 and 0.

6.

11. Formwork equipment (10) comprising a plurality of beams (1) mounted on a vertical structure (7) and a plurality of beams (2) according to one of claims 1 to 10 positioned on the beams (1) to form a horizontal formwork floor (P).

12. A method of assembling formwork equipment (10) according to claim 11, the method comprising steps of: • Mounting a plurality of beams (1) on a vertical structure (7) • Positioning a plurality of beams (2) on the beams (1) to form a horizontal formwork floor (P).

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