EP0119940B1 - Metallic reinforcing system to join two concrete building parts - Google Patents

Abstract

1. A metallic framework system to bind together two pieces of structural concrete, of the type comprising a bed (3) of friable material which, intended to be placed in the shuttering of the first structural piece, serves to accommodate those portions (6) of the framework (4) that are to be included in the second structural piece and from which project portions (5) of the framework (4) that are to be included in the first structural piece, characterised in that the inner surface of the bed of friable material (3) in contact with the concrete of the first structural piece is covered by at least one band (7) or the like extending beyond the bed of friable material in such a way as to remain accessible at the level of the visible face of the latter after removal of the shuttering of the first structural piece.

Description

The subject of the present invention is a system of metallic reinforcement connecting between two parts of concrete work, according to the preamble of claim 1.

The size and shape of reinforced concrete structures generally require their realization in several parts which are formwork successively.

To ensure the continuity of the reinforcement, it is necessary that parts of it be embedded in both parts of the work successively concreted.

A first solution consists in piercing the formwork and passing it through the connecting reinforcement. This solution has the disadvantage of degrading the formwork and making formwork long and difficult.

Another solution consists in folding up reinforcing pieces along the formwork, during the first concreting phase, then after formwork removal, broaching the concrete, in order to release and straighten them. This work is long and presents many uncertainties as to the quality of the result obtained.

Another possibility is to include part of the reinforcing pieces in bodies of rigid but brittle material, such as foam of synthetic material or a chipboard of sawdust.

In the embodiment described in French patent 2,261,817, the reinforcing pieces are bent so as to have an L-shaped profile. One of the branches of the L is embedded in a layer of synthetic material in the state liquid, which, upon drying, hardens while remaining brittle, ensuring excellent relative strength of the various component parts of the frame. This piece of synthetic material is then positioned inside the formwork of the first part of the work in the connection zone between the two parts of the work, so that the branches protruding from the piece of synthetic material protrude at inside the first formwork and are trapped in the first part of the structure after pouring the concrete.

After stripping, the synthetic material is broken and scraped so as to free the branches from the reinforcing parts it contained.

These branches are then unfolded so as to be brought in the extension of the branches embedded in the concrete of the first part of the structure. Formwork and reinforcement are then carried out on the second part of the structure which, after pouring the concrete, is firmly connected to the first part of the structure by the metal reinforcement pieces and by its inclusion inside the first part of the work at the level of the volume initially occupied by the synthetic material.

This second solution is much simpler to implement on site than the ancestral techniques, but of course requires removing the foam, this operation being carried out using common tools, such as trowel, nail puller, pick, hammer, etc.

It is the same when the reinforcing pieces are positioned in the friable element not before the casting thereof. but by introduction into holes and imprints which it presents in the rigid state.

The present invention aims to make this operation easier and faster.

To this end, in the system which it concerns, the wall of the layer of friable material in contact with the concrete of the first part of the work, is covered with at least one strip or the like projecting from the layer of friable material. so as to remain accessible at the visible face thereof after formwork removal from the first part of the structure.

This arrangement allows, by a traction exerted on an accessible end of the strip, to tear the friable material and to initiate its detachment from the concrete, which provides an appreciable time saving for the release of the reinforcing parts.

The strips are of width adapted to the panel and the reinforcements used, and can be solid, perforated, in the form of a ribbon, mesh, net, cord. They can be made of different materials, such as natural or synthetic textile, synthetic material, metal, etc.

Depending on the dimensions and the shape of each connecting element, it is possible to provide a single central strip, or several strips arranged on either side of the reinforcing pieces and between them.

According to one embodiment, the strips arranged on either side of the reinforcing pieces are formed by L or U profiles, one wing of which covers part of the large face of the layer of friable material, one of which is a wing. covers a small side face of this layer and the last wing of which in the case of a U-shaped section covers part of the other large side face.

This arrangement has the advantage of making it possible to tear off suddenly on the lateral parts of friable material. When these parts have been torn off the central area is easy to remove, since it has little adhesion to the concrete.

The strips or profiles can have a specific color facilitating the identification of the various reinforcement models used on the same work.

It has also been observed that the concrete area of the first part of the structure, in contact with the friable material, is relatively smooth, which must be avoided in certain applications.

Also, in accordance with another characteristic of the invention, each strip covering all or part of the wall of friable material in contact with the concrete of the first part of the work is impregnated with a setting retardant adjuvant.

Therefore, after formwork removal of the first part of the structure and removal of the synthetic material ensuring the strength of the connecting reinforcement pieces, the concrete surface is washed in the connection area between the two parts. of work, leaving it with a rough appearance.

• Figure 1 est une vue en perspective d'un premier élément de liaison entre deux parties d'ouvrage ;
• Figure 2 est une vue de cet élément après décoffrage de la première partie d'ouvrage;
• Figure 3 en est une vue en perspective au cours de la mise en position définitive des pièces d'armature ;
• Figure 4 est une vue en coupe transversale de l'élément de figure 3 ;
• Figures 5 et 6 sont deux vues en perspective de deux autres éléments de liaison ;
• Figures 7 à 10 sont des vues à échelle agrandie de quatre tronçons de bandes pouvant être utilisés dans les éléments de liaison schématisés précédemment ;
• Figures 11 à 14 sont des vues partielles, en coupe transversale , de quatre éléments équipés de quatre types de bandes latérales en forme de profilés ;
• Figure 15 est une vue en perspective d'une extrémité d'un élément équipé de profilés conformément aux formes d'exécution des figures 11 à 14.

In any case, the invention will be clearly understood with the aid of the description which follows with reference to the appended schematic drawing, representing by way of nonlimiting examples, several embodiments of this system:

• Figure 1 is a perspective view of a first connecting element between two parts of the work;
• Figure 2 is a view of this element after formwork removal of the first part of the structure;
• Figure 3 is a perspective view during the final positioning of the reinforcing pieces;
• Figure 4 is a cross-sectional view of the element of Figure 3;
• Figures 5 and 6 are two perspective views of two other connecting elements;
• Figures 7 to 10 are views on an enlarged scale of four sections of strips that can be used in the connecting elements shown previously;
• Figures 11 to 14 are partial views, in cross section, of four elements fitted with four types of lateral strips in the form of profiles;
• Figure 15 is a perspective view of one end of an element fitted with profiles in accordance with the embodiments of Figures 11 to 14.

Figure 1 shows a connecting element (2). This element comprises a layer (3) of rigid but brittle synthetic foam, of trapezoidal section.

The reinforcing elements (4) are held in the material layer (3). To this end, each frame part (4) comprises a central part (5) in a U extended by two branches (6) bent at 90 °. The two branches (6) are embedded in the layer of friable material (3) and the central U-shaped part (5) of each piece of reinforcement projects from the large face of the layer of friable material (3).

This layer of friable material (3) is covered on its large face, from which the parts (5) of the reinforcing pieces project, by a strip (7) extending over its entire length and projecting from at least one of its ends.

The connecting element (2) is positioned in a known manner inside the formwork of the first wall, the main thing being that one end (8) of the strip (7) is accessible after formwork removal.

Figure 2 shows a wall (9) constituting the first part of the work after formwork. by traction exerted on the strip (7) from its end (8), the friable material (3) is removed which releases the branches (6) from the reinforcing pieces (4). As shown in Figures 3 and 4, these branches (6) are unfolded for positioning within the formwork of a second perpendicular wall.

In the embodiment shown in Figures 1 to 4, the connecting element (2) is only equipped with a central strip (7).

In the embodiment shown in Figure 5 corresponding to a member (10) of greater width, in which are included reinforcing elements (4) of the same shape as before, there are provided three tear strips the friable material (3), namely a central strip (7) and two side strips (12).

In the embodiment shown in FIG. 6, the element (13) comprises a layer of friable material (3), from which protrude pieces of reinforcement constituted by pins (14) in the form of C.

In this case, two tear strips (15) and (16) are provided, located on either side of the pins (14).

Figures 7 to 10 show four embodiments of bands that can be used. These bands are constituted respectively by an openwork ribbon (17) shown in Figure 7, a mesh (18) shown in Figure 8, a net (19) shown in Figure 9 and a cord (20) shown in Figure 10 .

In the embodiment shown in FIG. 11, each lateral part of the layer of friable material (3) is equipped with an L-shaped profile (22), the wing (23) of which covers the large face thereof. facing the first part of the structure and the wing (24) of which covers a small lateral face thereof.

In the embodiment shown in FIG. 12, each lateral part of the layer of friable material (3) is equipped with a U-shaped profile (25), the core (26) of which covers a small lateral face of it. ci and the two wings (27) and (28) of which cover part of the large faces thereof facing respectively towards the first part of the structure and on the opposite side.

Figures 13 and 14 show arrangements corresponding respectively to those of Figures 11 and 12, but in which the profiles (22) and (25) have small returns (29) facing inwardly of the layer of friable material. These returns produce a local weakening of the friable material section, making it easier to tear off the latter.

FIG. 15 shows in perspective an embodiment of an element comprising lateral profiles (22, 25) and end profiles (30).

These bands in the form of ribbons or profiles can be made of different materials such as synthetic material, metal, natural or artificial textile, etc. As long as the material used is sufficiently porous, and if this is of interest in 'envisaged application, it can be soaked with an adjuvant forming retarder allowing, after washing the concrete, obtaining a rough surface.

As is apparent from the above, the invention brings a great improvement to the existing technique by providing a connection system between two parts of the concrete structure, the implementation of which on site is simple and rapid.

It goes without saying that the invention is not limited to the sole embodiments of this system described above by way of examples; on the contrary, it embraces all of the variant embodiments thereof, within the framework of the claims.

Claims (8)

1. A metallic framework system to bind together two pieces of structural concrete, of the type comprising a bed (3) of friable material which, intended to be placed in the shuttering of the first structural piece, serves to accommodate those portions (6) of the framework (4) that are to be included in the second structural piece and from which project portions (5) of the framework (4) that are to be included in the first structural piece, characterised in that the inner surface of the bed of friable material (3) in contact with the concrete of the first structural piece is covered by at least one band (7) or the like extending beyond the bed of friable material in such a way as to remain accessible at the level of the visible face of the latter after removal of the shuttering of the first structural piece.

2. A framework system according to Claim 1, characterised in that it comprises a band which, covering the inner surface of the bed of friable material in contact with the concrete of the first structural piece, is located in the central portion of the bed of friable material.

3: A framework system according to Claim 1, characterised in that it comprises two bands which, covering the inner surface of the bed of friable material in contact with the concrete of the first structural piece, are located at the laterial portions of the bed of friable material.

4. A framework system according to either of Claims 2 and 3, characterised in that each band covering the inner surface of the bed of friable material in contact with the concrete of the first structural piece is flat and is produced from a flexible material.

5. A framework system according to Claim 3, characterised in that each band laterally covering the bed of friable material is formed as a profile of "L"-shaped section, one wing of which covers a part of the main face of the bed of friable material that is turned towards the first structural piece, and the other wing of which covers one lateral face of the bed of friable material.

6. A framework system according to Claim 3, characterised in that each band laterally covering the bed of friable material is formed as a profile of "U"-shaped section, the crown of which covers one lateral face of the bed of friable material and the two wings of which cover parts of the main faces of the bed of friable material that are turned towards and away from the first structural piece respectively.

7. A framework system according to either of Claims 5 and 6, characterised in that at least one of the extremities of the laterally-disposed profiles comprises a return edge, directed towards the interior of the bed of friable material.

8. A framework system according to any of Claims 1 to 7, characterised in that each band (7, 12, 15, 16) that covers all or part of the inner surface of friable material (3) that is in contact with the concrete of the first structural piece is impregnated with an additive that delays the setting.

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