EP3483339B1 - Method for easier renovation of expansion joint for concrete slabs shuttering system - Google Patents

Description

TECHNICAL AREA

The present invention relates to the technical field of concrete slab formwork systems providing an expansion joint between two adjacent slabs. The present invention relates more particularly to an improved expansion joint, particularly in terms of ease of renovation.

PRIOR ART

In the field of construction, and in particular that relating to the covering of the ground by concrete slabs, it is well known to use a formwork system including expansion joints between the slabs. Indeed, it is customary to divide the concrete slab into several parts, depending on its surface area and its thickness, to create an air space necessary for absorbing the variations in volume of a slab, for example under the action of withdrawal.

A known formwork system generally comprises an expansion joint comprising first and second longitudinal elements, arranged side by side on the same horizontal plane, and each intended to form an integral part with an upper and horizontal edge of a concrete slab. The first longitudinal element is secured to a vertical separation plate intended to form the vertical border between the two adjacent concrete slabs. After a horizontal force of retraction of at least one concrete slab, the first and second longitudinal elements are separated from each other, each remaining integral with the concrete slab with which it forms an integral part.

The document DE 20 2005 008762 U1 discloses such a formwork system.

At the end of their life, or when these formwork systems and expansion joints are incorrectly installed, the opening of the expansion joint after retraction of the concrete slabs can cause shocks or jolts leading to deterioration of the concrete and the longitudinal elements. of said expansion joint.

Thus, only one fairly restrictive solution for renovating the joint consists of sawing or breaking the concrete with a pneumatic drill to be able to permanently remove the longitudinal elements of the expansion joint, and pouring a filling material such as resin or concrete in the recess generated by the removal of joints and broken concrete.

DISCLOSURE OF THE INVENTION

One of the aims of the invention is therefore to remedy these drawbacks by proposing a simplified renovation process for an expansion joint for a formwork system for concrete slabs when damage to the longitudinal elements of the joint or of the concrete in contact with these elements have intervened.

To this end, and to solve the aforementioned problems, a method according to claim 1 has been developed.

The invention makes it possible, when the longitudinal elements of the expansion joint have a vertical offset, resulting in shocks and jolts during the passage of vehicles, to be able to sand said longitudinal elements to achieve optimum planimetry. The renovation is very quick and simply consists of a sanding step.

Of course, the sandable nature of the longitudinal elements is independent of the removable nature so that it could be envisaged to develop an expansion joint remarkable in that it comprises first and second longitudinal elements made of a polymer material, or in a composite material made from a polymer material, without these having a removable nature.

BRIEF DESCRIPTION OF FIGURES

• la figure 1 est une vue en perspective illustrant une forme de réalisation du joint de dilatation selon l'invention, avant rétractation des dalles de béton ;
• la figure 2 est une vue en perspective similaire à celle de la figure 1, après rétractation des dalles de béton ;
• la figure 3 est une représentation en coupe transversale de la forme de réalisation du joint de dilatation illustrée à la figure 1, avant rétractation des dalles de béton ;
• la figure 4 est une représentation en coupe transversale de la forme de réalisation du joint de dilatation illustrée à la figure 2, après rétractation des dalles de béton.

Other advantages and characteristics will emerge better from the following description of several variant embodiments, given by way of non-limiting examples, of the expansion joint according to the invention, with reference to the appended drawings in which:

• there figure 1 is a perspective view illustrating an embodiment of the expansion joint according to the invention, before shrinkage of the concrete slabs;
• there picture 2 is a perspective view similar to that of the figure 1 , after shrinkage of the concrete slabs;
• there picture 3 is a cross-sectional representation of the expansion joint embodiment shown in figure 1 , before shrinkage of the concrete slabs;
• there figure 4 is a cross-sectional representation of the expansion joint embodiment shown in picture 2 , after shrinkage of the concrete slabs.

DETAILED DESCRIPTION OF THE INVENTION

The invention relates to a method for renovating an expansion joint (1) for a formwork system for concrete slabs which implements at least one vertical separation plate of two adjacent concrete slabs, and which is used when it is necessary, for the pouring of the concrete, to divide the concrete slab into several parts, according to its surface and its thickness, to create an air space necessary for the absorption of the variations of volumes of a slab, for example under the action of withdrawal.

With reference to figures 1 to 4 , the expansion joint (1) comprises first and second longitudinal elements (2, 3), arranged side by side on the same horizontal plane, and each intended to form an integral part with an upper and horizontal edge of a concrete slab .

The first longitudinal element (2) is integral with a vertical separation plate (4) of the two adjacent slabs.

The first and second longitudinal elements (2, 3) can be made of metal, or else of a material suitable for being sanded, such as a polymer or a composite material made from a polymer, for example plastic or resin.

Thus, when the expansion joint is damaged or incorrectly installed, and the longitudinal elements (2, 3), which form the upper edges of the slabs, are offset vertically, shocks and jolts occur when vehicles pass by. wheels, causing damage to the concrete and accelerated deterioration of the concrete and the expansion joint (1).

The sanding nature of the longitudinal elements (2, 3) makes it possible to relevel said longitudinal elements (2, 3) by a sanding operation and to obtain an optimal planimetry of the expansion joint (1) and of the concrete slabs. Thus, the renovation of the expansion joint (1) is facilitated.

The invention also makes it possible to remedy this problem by the following characteristics, taken in combination with the sandable nature of the longitudinal elements (2, 3), according to which the said longitudinal elements (2, 3) comprise fittings, emerging at the level of the walls horizontal upper parts of said first and second longitudinal elements (2, 3), and allowing at least a part (2a, 3a) of each of the first and second longitudinal elements (2, 3) to be removed for their replacement.

According to a preferred embodiment, the first longitudinal element (2) comprises a stack of three layers of material, including an upper layer (2a), an intermediate layer (2b), and a lower layer (2c). The intermediate layer (2b) comprises a smaller width than that of the upper (2a) and lower (2c) layers so that the first longitudinal element (2) has a U-shaped cross section.

Similarly, the second longitudinal element (3) comprises a stack of three layers of complementary material, including an upper layer (3a), an intermediate layer (3b), and a lower layer (3c) whose width is greater. than that of the upper (3a) and lower (3c) layers so as to form a transverse projection capable of fitting into the hollow of the U-shape of the first longitudinal element (2) and allowing the transfer of vertical loads.

The first and second longitudinal elements (2, 3) comprise orifices (5) arranged in their thickness so as to pass vertically through all of the three layers (2a, 2b, 2c, 3a, 3b, 3c). These orifices (5) are suitable for receiving rods (6) fixed at their lower ends to fixed parts of the expansion joint (1) by insertion. For example, the lower ends of the rods (6) are welded to the lower layers (2c, 3c) of the first and second longitudinal elements (2, 3). The lower ends of the rods (6) can also be fixed to fixed parts of the formwork system on which the expansion joint is mounted without departing from the scope of the invention. The upper ends of the rods (6) do not protrude from the first layers (2a, 3a) of the first and second longitudinal elements (2, 3), and are, for example, threaded to cooperate with clamping members (7) for locking in position at least the upper layers (2a, 3a) of the first and second longitudinal elements (2, 3). Conversely, when these clamping members (7) are unscrewed, the upper layers (2a, 3a) of said first and second longitudinal elements (2, 3) can be removed and replaced, in particular when they are damaged or when t a vertical shift generating shocks and jolts is felt when a vehicle passes.

The width of the upper layer (2a) of the first longitudinal element (2) is greater than the width of the upper layer (3a) of the second longitudinal element (3), and the lower layer (2c) of the first longitudinal element (2 ) is secured to the vertical separation plate (4), for example by welding, such that the vertical plane defined by the separation plate (4) is offset horizontally with respect to the vertical plane (P) defined between the first and second longitudinal elements (2, 3). Thus, with reference to figure 2 And 4 , when the concrete slabs retract, the longitudinal elements (2, 3) move away from each other but still rest on one of the concrete slabs. The stability of the joint is optimal and the appearance of disorders, such as cracks or breaks, is reduced.

The expansion joint (1) described comprises first and second longitudinal elements (2, 3) each having removable parts, constituted in particular by the upper layers (2a, 3a).

Other embodiments can be imagined without departing from the scope of the invention. For example, the intermediate (2b, 3b) and lower (2c, 3c) layers of the first and second longitudinal elements (2, 3) can form a one-piece assembly, or else the first longitudinal element (2) can be produced in a single part fixed directly in a removable manner, by the same means as mentioned above, on the vertical separation plate (4) provided for example with an upper flange at right angle.

In order to ensure continuity at the level of the separation between the two concrete slabs, the removable parts of the first and second longitudinal elements (2, 3), in particular the upper layers (2a, 3a), have facing faces comprising complementary sinusoidal profiles. Thus, during the passage of a vehicle, the wheels always remain supported by the surface of one of the adjacent slabs. This characteristic makes it possible to limit the shocks and the wear of the concrete slabs near the expansion joints.

Claims (1)

1. - Method for renovating an expansion joint (1) for a concrete slab formwork system, of the type comprising first and second longitudinal elements (2, 3), arranged side by side on the same horizontal plane, and each intended to form an integral part with an upper and horizontal edge of a concrete slab, the first longitudinal element (2) being integral with a vertical separation plate (4), the first and second longitudinal elements (2, 3) being capable of being vertically offset from each other, and being made of a resin or of a composite material made from a polymeric material, characterized in that the first and second longitudinal elements (2, 3) are sanded when they have a vertical offset, so as to level said longitudinal elements (2, 3).

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