ES2634710T3 - Formwork system comprising an improved expansion joint - Google Patents

Abstract

Formwork system (D) of concrete slabs comprising, at least a first and a second horizontal support base (1, 2) profiled and arranged presenting a plurality of protruding shapes (1a, 2a) and cutouts (1b, 2b) capable of interlocking by embedding, rods (3) received on the horizontal support bases that constitute means of setting the concrete, an expansion joint, a vertical separation element (5) of expansion joint, first pairs of squares (4a , 4b) solidary of the first support base (1) and having a vertical branch that allows the height-adjustable fixation of the vertical separation element (5), a vertical counter plate (9) in a fixed position, second pairs of brackets ( 8a, 8b) solidary of the second support base (2), arranged in opposition to said first pairs of squares (4a, 4b) and allowing the fixing of the vertical counter plate (9), and a mocking joint (6) , the separation element v ertical (5) of the expansion joint comprising vertical oblong lights (5a) that extend over a part of its height and the counter plate (9) and the first and second pairs of squares (4a, 4b) (8a, 8b ) comprising holes (9a) (4c) (8c) that allow the integration of the mocking joint (6) for the regulation and fixing of the separation element (5) in relation to the counter plate (9) characterized in that said Expansion joint is presented in the form of a first longitudinal element (10a) and a second longitudinal element (10b) having identical sinusoidal profiles, interwoven with one another so that the crests of the first longitudinal element (10a) are coupled with the gaps of the second longitudinal element (10b), each longitudinal element (10a, 10b) being intended to form an integral part with an upper and horizontal edge of a concrete slab, the longitudinal elements (10a, 10b) comprising widths determines given so that they define external sinusoidal profiles each destined to come into contact with a concrete slab and internal sinusoidal profiles in contact with each other, the longitudinal elements (10a, 10b) comprising rods (11) forming protrusion of one face lower and oriented in the opposite direction towards the outside to constitute means for setting the concrete, the lower face of the first longitudinal element (10a) being welded directly on the separation element (5) arranged on its length extending orthogonally to said lower face and intended to perform a vertical separation between two adjacent concrete slabs, the second longitudinal element (10b) being attached to the separation element (5) or the first longitudinal element (10a) by fixing means (12) capable of breaking under a horizontal stress of retraction of at least one concrete slab, so that the two longitudinal elements (10a, 1 0b) move away from each other with the first longitudinal element (10a) remaining integral with the separation element (5), the amplitudes and widths of the longitudinal elements (10a, 10b) being such that the external sinusoidal profiles of the longitudinal elements (10a, 10b) do not cross a longitudinal plane defined by the separation element (5).

Description

5

10

fifteen

twenty

25

30

35

40

Four. Five

fifty

55

60

65

DESCRIPTION

Formwork system comprising an improved expansion joint Ambito TECNICO

The present invention concerns the technical field of concrete slab formwork systems that facilitate an expansion joint between two adjacent slabs. The present invention relates more particularly to a formwork system comprising an improved expansion joint.

PREVIOUS TECHNIQUE

In the field of construction, and in particular that related to the coverage of the ground by concrete slabs, it is well known to use a formwork system that includes expansion joints between the slabs. In fact, it is usual to divide the concrete slab into several parts, depending on its surface and its thickness, to create a necessary air space for the absorption of the variations of the volumes of a slab, for example under the effect of the retraction.

These formwork systems are generally installed with "L" profiled plates arranged in opposition, their wings being next to each other and being joined with the aid of specific link means. These plates have on their base, and alternatively, horizontal cut-out and protruding shapes in a complementary configuration to fit and allow the insertion of identical shapes arranged on each of the flat parts of the aforementioned plates. In a known manner, these plates are also installed with rods arranged from the horizontal bases of the plates and from their vertical walls constituting means for setting the concrete.

These plates are linked to each other by means of teasing and can be separated horizontally from each other to take into account the retraction of the concrete in the solidification phase and the variations in the external temperature. The space between the plates allows the placement of expansion joints.

Such a formwork system is especially described in European patent application EP 1 391 556.

This document describes a device intended to establish a connection between two adjacent concrete slabs by equipping the expansion joint between said slabs. The device is constituted by a set of two modules taken from sheets, each of the modules comprising a first series of flat elements, which form projections, a second series of square-shaped elements, integral with said projections. The square-shaped elements comprise a first flat part that is in the same plane as said projections and a second raised flat part that forms a square with said first part and flat elements that are in the same plane as said raised parts and which form connections in the form of first stringers between said raised parts.

The assembly is made by mounting two modules, so that the raised parts of the elements of the second series and the elements that form the stringers are face to face, being on both sides of a medium plane and so that the projections of each module extend on one side and on the other of said middle plane.

Also known is EP 1 389 648 which describes an apparatus for forming the edge of a concrete slab. Said apparatus comprises a separator plate formed with several openings, pins intended to penetrate inside the openings, bushings intended to be applied on the pins and an adjustment device, during use, of the height of the apparatus above the ground. The separating plate comprises at its upper end, a first linear rail integral with said separating plate, and a second linear rail integral with the first rail by plastic screws and nuts. Each lane comprises anchoring devices intended to be incorporated inside the concrete. Thus, at the time of the concrete retraction, on the one hand and on the other of the rails, the plastic screws are broken and the rails are separated relative to each other.

These devices allow the realization of perfectly horizontally leveled concrete slabs. Such devices allow horizontal movement between two adjacent slabs to compensate for the shrinkage of the concrete at the time of drying. However, it has been found that the separation between the two adjacent slabs is constituted by a groove between two metal joints so that in case of use of forklift trucks or other similar means of transport, disorders such as cracks or degradations appear in the vicinity of said metal seals due to wheel collisions on the metal seals. These disorders can deteriorate the concrete slab until the appearance of holes.

In order to remedy this problem, a concrete slab formwork device has already been imagined in which the joint is not linear in order to limit shocks at the time of the passage of wheels on the metal joints.

5

10

fifteen

twenty

25

30

35

40

Four. Five

fifty

55

60

65

This is the case, for example, of the international patent application WO 2007/144008. This patent application describes a joint capable of being coupled with concrete slabs and comprising at least two profiled elements. Each profiled element is designed to be in one piece with one of the edges of two adjacent plates and comprises a substantially vertical rod capable of extending at least partially along the edges to a living edge of an upper surface of the plate . The upper edge of each vertical rod of the profiled elements of two adjacent plates, as seen along the line between the two adjacent plates, is composed of non-linear elements, especially sinusoidal elements.

Thus, taking into account the fact that the slot-like separation between two adjacent slabs is not linear but sinusoidal, the wheel of a forklift carriage or other means of transport that have wheels will not tend to fall between the two adjacent boards of the board. Said wheel will stop hitting said plates at the moment of passing over the joint, but will always be supported by the surface of one of the adjacent slabs. This feature allows to limit shocks and, finally, the wear of concrete slabs in the vicinity of expansion joints.

However, this type of joint has the disadvantage that it does not facilitate a distribution of the stresses, especially the thickness of the tile. In fact, the non-linear plates, especially sinusoidal ones, that form the joints are respectively supportive of a support plate that has a superior U-shaped profile. Each sinusoidal plate is integral with the upper branch of the U and the two plates U-shaped are embedded inside each other. Thus, at the time of pouring concrete on one side of the joint, the concrete of a first slab of concrete extends above the second slab of adjacent concrete and the concrete of the second slab of concrete extends above the first concrete slab so that the stresses, in the vicinity of the joint, are not uniform, causing disorders in the concrete to appear in the vicinity of the expansion joint over time. In other terms, the concrete does not work at its full height to recover the efforts that are applied to it.

EXHIBITION OF THE INVENTION

One of the objects of the invention is therefore to remedy these inconveniences by proposing a concrete slab formwork system comprising a perfected expansion joint, simple and little expensive concession, which allows to avoid the appearance of disorders in the tiling in the proximity of the joints at the time of repeated steps on said joint, ensuring a uniform distribution of the stresses in the concrete, on the one hand on the other of the expansion joint.

For this purpose and according to the invention, a concrete slab formwork system according to claim 1 is proposed.

In this way, the sinusoidal profile of the expansion joint makes it possible to ensure continuity at the level of the separation between two concrete slabs and this over its entire height. The wheel of a vehicle always remains supported by the surface of one of the adjacent slabs. This feature allows to limit shocks and, finally, the wear of concrete slabs in the vicinity of expansion joints.

In addition, the characteristic according to which the external sinusoidal profiles of each sinusoidal element do not cross the longitudinal plane defined by the separation element allows to avoid the disorders in the concrete at the level of the expansion joint. Indeed, at the time of pouring the concrete with one part and on the other side of the joint, the concrete of the first slab remains on one side of the plane defined by the vertical separation element and does not extend above the second adjacent concrete slab. This is the same for the second concrete slab. Thus, the stresses in the concrete in the vicinity of the joint are distributed evenly over the entire thickness of the tile, which very clearly reduces the appearance of disorders, such as cracks or breaks.

According to a particular embodiment of the expansion joint according to the invention, the width of each sinusoidal element is greater than or equal, and preferably equal to twice the amplitude of its sinusoidal profile.

Several solutions are possible to make the first sinusoidal element integral to the vertical separation element. For example, said first sinusoidal element is welded directly on the separation element, or it is welded on a first intermediate piece itself welded on the separation element. The intermediate piece is presented, for example, in the form of a square, or in the form of a parallelepipedic piece, welded, on the one hand, to the first sinusoidal element and, on the other hand, to the separation element.

These solutions allow to obtain a expansion joint of simple and little onerous conception.

According to a particular embodiment, the fixing means are presented in the form of two hollow cylinders, coaxially installed in relation to each other, and held against each other by a plastic screw that pass through the two cylinders and one against nut. The two cylinders are each made integral with a sinusoidal element, the two being positioned perpendicularly to said sinusoidal elements and coupled through an opening arranged in the separation element.

5

10

fifteen

twenty

25

30

35

40

Four. Five

fifty

55

60

65

According to another particular embodiment, the fixing means comprise intermediate parts that are made integral with the second sinusoidal element and fixed to the separation element by means of plastic screws and nuts, the screws being destined to break under the retraction effort of At least one concrete slab.

According to different embodiments, the pieces that are in solidarity with the second sinusoidal element can be presented in the form of squares, or with parallelepipedic pieces, on the one hand welded to the second sinusoidal element and, on the other hand fixed to the separation element by means of plastic screws and nuts.

Advantageously, the expansion joint has a support free surface of a lifting means at the level of the lower face of the first sinusoidal element. This feature makes it possible to raise or lower said expansion joint through a lifting means to ensure the adaptability of said formwork system to the thicknesses of the concrete slabs to be formed.

SUMMARY DESCRIPTION OF THE FIGURES

Other advantages and features will become better apparent from the following description of various variants of execution, provided by way of non-limiting examples, of the concrete slab formwork system according to the invention, with reference to the attached drawings in which:

- Figure 1 is a perspective view illustrating the support bases of the concrete slab formwork system and the anchoring of said concrete slabs;

- Figure 2 is a perspective view of the formwork system according to the invention equipped with an expansion joint perfected according to the invention;

- Figure 3 is a top view of the formwork system of Figure 2;

- Figure 4 is a front view of the formwork system of Figure 2;

- Figure 5 is a view from behind of the formwork system of Figure 2;

- Figure 6 is a side view from above to illustrate the plane defined by the vertical plate;

- Figure 7 is a side view of the formwork system in the lowered position;

- Figure 8 is a side view of the system in an elevated position.

DETAILED DESCRIPTION OF THE INVENTION

The invention concerns a formwork system (D) of concrete slabs used when it is necessary, for concrete casting, the division of the concrete slab into several parts, depending on their surfaces and thickness, to create a air space necessary for the absorption of variations in the volumes of a slab, for example under the action of retraction.

The formwork system (D) implements at least one vertical separation element (5) of two adjacent concrete slabs, in the form of a metal plate (5).

Thus, with reference to figures 1 to 6, the concrete slab formwork system with expansion joints is referenced by (D). It comprises over a large length two horizontal support bases (1, 2) profiled and installed each with a plurality of protruding shapes (1a, 2a) and cutouts (1b, 2b) capable of interlaced interleaving. These support bases are especially illustrated in Figure 1. They receive in a known manner rods (3) arranged obliquely and which constitute means for setting the concrete.

With reference to Figures 2 and 4, the first horizontal support base (1) receives on its apparent face a plurality of first pairs of squares (4a, 4b) separated according to the length of the support base (1). The squares (4a, 4b) of the same pair are substantially separated from each other. The number of pairs of squares (4a, 4b) depends on the length of the formwork. In order to simplify the figures, only a part of the formwork system (D) comprising a pair of squares (4a, 4b) has been represented in the figures. Its fixation to the support base (1) is carried out by any appropriate technique, preferably by welding. The pairs of squares (4a, 4b) are connected by the free end of their vertical branches by means of a link arm (4d). From said link arm (4d), said pairs of squares (4a, 4b) allow the fixing of the metal vertical plate (5), preferably made of thin sheet, for example 2 mm thick. This vertical plate (5) is intended to perform a vertical separation between two adjacent concrete slabs at the time of the formwork.

5

10

fifteen

twenty

25

30

35

40

Four. Five

fifty

55

60

65

The link arm (4d) that connects each pair of brackets (4a, 4b) has an opening (4c) for the insertion of mocking joints (6), as well as is specified in the following. The vertical plate (5) is thus arranged with a plurality of oblong lights (5a), vertical, in number corresponding to the number of pairs of squares (4a, 4b) mentioned above. The upper part of the plate (5) is made integral with a first longitudinal sinusoidal element (10a) and a second longitudinal sinusoidal element (10b), later referred to as "sinusoidal elements" to constitute a expansion joint as will be required more later in this description.

The second support base (2) is also arranged for the reception of second pairs of squares (8a) (8b) whose free ends of their vertical branches are also connected by means of a link arm (8d). The second pairs of squares (8a) (8b) are intended to be in opposition to said first pairs of squares (4a, 4b). Its fixation to the second support base (2) is carried out by any appropriate technique, preferably by welding. Due to their vertical branches, the second pairs of squares (8a, 8b) allow the fixing of a vertical, metal, sheet metal counter (9), for example, of a thickness substantially similar to that of the vertical plate (5). The second pairs of squares (8a) (8b), and more particularly the link arm (8d), and the counter plate (9) are also arranged with circular openings (8c) (9a) for the passage and introduction of the means of mocking joints (6) and blocking mentioned above.

Thus, the plate (5) can be adjusted in vertical position in height in relation to the counter plate (9) to which it is fixed. The height adjustment according to the needs is carried out by the deviation of the different oblong lights (5a) that allow the junctions to pass through mocking (6). The length of the oblong lights therefore defines the possible adjustment height between the plate (5) and the counter plate (9). The size of the plate (5) is therefore set in relation to the height of the counter plate (9). Thus, depending on the needs, the plate (5) can be placed at a constant horizontal height in relation to the counter plate (9), or at an inclination according to a slight angle that is allowed precisely by said lights (5a) .

According to the invention, in its upper part, this plate (5) has a horizontal support plane (5b) on which it is fixedly connected, by any appropriate means, and preferably by welding, the first sinusoidal element (10a) . In other terms, the first sinusoidal element (10a) is arranged over the entire length of the plate (5) so that it forms a horizontal support plane and is coupled with the second identical sinusoidal element (10b). More precisely, the sinusoidal elements (10a, 10b), with the vertical plate (5) form the expansion joint as such. The vertical plate (5) extends orthogonally from the lower face of the first sinusoidal element (10a).

The two sinusoidal elements (10a, 10b) are interwoven with each other so that the crests of the first sinusoidal element (10a) are coupled with the gaps of the second sinusoidal element (10b). Each sinusoidal element (10a, 10b) is intended to be an integral part with an upper and horizontal edge of a concrete slab. The sinusoidal elements (10a, 10b) comprise widths determined so as to define external sinusoidal profiles each intended to be in contact with a concrete slab and internal sinusoidal profiles in contact with each other. Each sinusoidal element (10a, 10b) comprises rods (11) that form projections of a lower side, obliquely, and in the opposite direction facing outward to constitute concrete setting means, arranged thus to ensure a balanced.

According to the invention, the second sinusoidal element (10b) comprises fixing means (12) to said vertical plate (5). More precisely, these fixing means (12) comprise square pieces (12a), on the one hand welded to said second sinusoidal element (10b) and on the other part fixed on the vertical plate (5) by means of plastic screws ( 12b) and nuts (12c). The plastic screws (12b) are intended to break under the retraction effort of at least one concrete slab.

According to the invention and with reference to Figures 6 to 8, the sinusoidal elements (10a, 10b) are designed so that their amplitudes and widths allow the vertical plate (5) to be attached to the first sinusoidal element (10a) so that the external sinusoidal profiles of the sinusoidal elements (10a, 10b) do not cross the longitudinal plane defined by the vertical separation plate (5).

According to a particular embodiment of the formwork system according to the invention, the width of each sinusoidal element (10a, 10b) is greater than or equal, and preferably equal to twice the amplitude of its sinusoidal profile.

A person skilled in the art will, of course, adapt the amplitude accordingly based on the expected retraction between the concrete slabs. As a general rule, an amplitude equal to 1 cm is sufficient.

The mocking joints (6) put into practice, as well as the screws (12a) are made of nylon or plastic material so that when the concrete retracts horizontally, said screws (12a) break and the two sinusoidal elements, as well as the plate (5) and the counter plate (9) move away from each other. The first sinusoidal element (10a) remains on the plate (5) and coupled with the horizontal upper edge of the concrete slab and the second sinusoidal element (10b) remains coupled with the horizontal upper edge of the other adjacent concrete slab.

5

10

fifteen

twenty

25

30

35

In this way, the sinusoidal profile of the expansion joint makes it possible to ensure continuity at the level of the separation between the two concrete slabs. Thus, a wheel of a vehicle that circulates on the tile and that passes from one slab to the other will always remain supported by the surface of one of the adjacent slabs. This feature allows to limit shocks and, finally, the wear of concrete slabs in the vicinity of expansion joints.

In addition, the characteristic according to which the external sinusoidal profiles of each sinusoidal element (10a, 10b) do not cross the longitudinal plane defined by the vertical separation plate (5) allows to avoid the disorders in the concrete at the level of the expansion joint. In fact, at the time of pouring of the concrete on the one hand on the other side of the joint, the concrete of the first slab remains on one side of the plane defined by the vertical plate (5) and does not extend above the second adjacent concrete slab. This is the same for the second concrete slab. Thus, the stresses in the concrete in the vicinity of the joint are distributed evenly over the entire thickness of the slab, which very clearly reduces the appearance of disorders, such as cracks or breaks.

Other fixing techniques are possible between the sinusoidal elements (10a, 10b) and the vertical plate (5), the essential thing lies in the fact that in case of concrete retraction, the fixing elements (12) are broken and the two sinusoidal elements (10a, 10b), as well as the plate (5) and the counter plate (9) move away from each other, with the first sinusoidal element (10a) remaining on the plate (5) and coupled with the edge horizontal top of the concrete slab and the second sinusoidal element (10b) that remains coupled with the upper horizontal edge of the other adjacent concrete slab.

For example, it could be contemplated to obtain the same effect that the fixing elements (12) are presented in the form of two hollow cylinders, coaxially installed relative to each other and held against each other by a plastic screw that they cross the two cylinders and one against nut. The two cylinders are each made integral with a sinusoidal element (10a, 10b), the two being placed perpendicularly to said sinusoidal elements (10a, 10b) and coupled through an opening arranged in the separation element (5).

Advantageously, the support plane (5b) of the vertical plate (5) is established on a part only of the width of the sinusoidal element (10a) leaving free a support area of a lifting means known in the state of the technique and especially disclosed in the international patent application WO 2013/072619.

The lifting means comprises means capable of coming into lower contact with the base of the first sinusoidal element (10a) of the expansion joint. After loosening the mocking means (6), it is thus possible for the operator to cause the vertical plate to rise or fall (5) in relation to the counter plate (9), which increases the height of the system formwork (D) asf constituted.

Finally, it is very evident in the examples that have just been provided, they are no more than particular illustrations in any case limiting the scope of the invention.

Claims (7)

5 10 fifteen twenty 25 30 35 40 Four. Five fifty 55 1. Formwork system (D) of concrete slabs comprising, at least a first and a second horizontal support base (1, 2) profiled and arranged presenting a plurality of protruding shapes (1st, 2nd) and cutouts ( 1b, 2b) capable of interlocking by embedding, rods (3) received on the horizontal support bases that constitute means of setting the concrete, a expansion joint, a vertical separation element (5) of expansion joint, first pairs of squares (4a, 4b) integral with the first support base (1) and having a vertical branch that allows the height-adjustable fixation of the vertical separation element (5), a vertical counter plate (9) in a fixed position, second pairs of brackets (8a, 8b) in solidarity with the second support base (2), arranged in opposition to said first pairs of brackets (4a, 4b) and which allow the fixing of the vertical counter plate (9), and a mocking joint ( 6), the vertical separation element ( 5) of the expansion joint comprising vertical oblong lights (5a) that extend over a part of its height and the counter plate (9) and the first and second pairs of squares (4a, 4b) (8a, 8b) comprising holes (9a) (4c) (8c) that allow the integration of the joint by mocking (6) for the regulation and fixing of the separation element (5) in relation to the counter plate (9) characterized in that said gasket of dilatation is presented in the form of a first longitudinal element (10a) and a second longitudinal element (10b) having identical sinusoidal profiles, interwoven with one another so that the crests of the first longitudinal element (10a) are coupled with the gaps of the second longitudinal element (10b), each longitudinal element (10a, 10b) being intended to form an integral part with an upper and horizontal edge of a concrete slab, the longitudinal elements (10a, 10b) comprising widths determined so that d They define external sinusoidal profiles each destined to come into contact with a concrete slab and internal sinusoidal profiles in contact with each other, the longitudinal elements (10a, 10b) comprising rods (11) forming protrusion of a lower face and oriented in opposite direction towards the outside to constitute setting means of the concrete, the lower face of the first longitudinal element (10a) being welded directly on the separation element (5) arranged on its length extending orthogonally to said lower face and intended to make a separation vertical between two adjacent concrete slabs, the second longitudinal element (10b) being attached to the separation element (5) or the first longitudinal element (10a) by fixing means (12) capable of breaking under a horizontal retraction effort of at least one concrete slab, so that the two longitudinal elements (10a, 10b) move away from each other with the first longitudinal element (10a) remaining integral with the separation element (5), the amplitudes and widths of the longitudinal elements (10a, 10b) being such that the external sinusoidal profiles of the longitudinal elements (10a, 10b) do not cross a longitudinal plane defined by the separation element (5). 2. Formwork system (D) according to claim 1 characterized in that the width of each longitudinal element (10a, 10b) is greater than or equal to the amplitude of its sinusoidal profile. 3. Formwork system (D) according to claim 2 characterized in that the width of each longitudinal element (10a, 10b) is equal to twice the amplitude of its sinusoidal profile. 4. Formwork system (D) according to any of the preceding claims characterized in that the fixing means (12) are presented in the form of two hollow cylinders, arranged coaxially with respect to each other and held against each other by a plastic screw that crosses the two cylinders and one against the nut, the two cylinders being integral with each of a longitudinal element (10a, 10b), the two being placed perpendicularly to said longitudinal elements (10a, 10b) and coupled through a opening arranged in the separation element (5). 5. Formwork system (D) according to any one of claims 1 to 3 characterized in that the fixing means (12) comprise intermediate parts (12a) which are made integral with the second longitudinal element (10b) and fixed to the separation element ( 5) by means of plastic screws (12b) and nuts (12c). 6. Formwork system (D) according to claim 5 characterized in that the intermediate pieces that are made integral with the second longitudinal element (10b) are presented in the form of squares (12a) or parallelepipedic pieces, on the one hand welded to the second longitudinal element (10b) and, on the other hand, fixed in the separation element (5) by means of plastic screws (12b) and nuts (12c). 7. Formwork system (D) according to any of the preceding claims, characterized in that it has a support free surface of a lifting means at the level of the lower face of the first longitudinal element (10a).