EP0055666A1 - Panel for the connection of reinforcing rods in concrete - Google Patents

Abstract

1. A link rod panel for reinforced concrete, the panel being made by moulding a synthetic foam and being capable of being fixed by one of its faces against the inside face of shuttering, characterized in that it presents a set of regularly spaced transverse orifices (2) opening out in grooves (16, 20) in the face (18) intended to be applied against the shuttering, which grooves are at least as deep as the diameter of a link bar (13, 14, 15), thereby enabling folded link bars to be inserted inside the panel immediately prior to the panel being fixed to the shuttering.

Description

The subject of the present invention is a reinforcing link panel intended in particular, but not exclusively, to allow the connection between the reinforcements of a first part of the structure obtained by a first concrete pour and the reinforcements of a second part of the work which can be obtained by a second pouring of concrete or by assembling various materials such as bricks, for example, said second part having to be integral with the first.

Insofar as the reinforcements of the first phase concrete must be joined to those of the second phase to ensure a good connection between the two phases, it is necessary to provide means which must be an integral part of the two components of the structure. These means can consist either of a set of connecting reinforcements taking up the efforts of the reinforcements included in the two parts of the structure, or of connection sleeves, crimped and / or tapped for example.

The problem which arises is twofold: the connection must be effective, that is to say ensure a good transmission of the forces between the two parts of the structure; the positioning of the connecting elements and their maintenance in good position, in particular during the pouring of the first phase concrete, must be ensured. It is known that the pouring of the first phase concrete is usually carried out in a formwork which reproduces in hollow the external contour of the first part of the structure. In the case where connection reinforcements are used, a first end of these is connected, for example by overlapping with the reinforcements of the first phase concrete. The second end of said connecting frames can then either pass through holes drilled in the formwork and thus be in the standby position for pouring the second phase, or be folded back inside the formwork, this second solution, more economical being the most commonly used. After removal of the formwork, usually made of wood, the second ends are unfolded so that they are in an adequate position to fulfill their role of transmitting forces to second phase reinforcements, by covering or by any other means.

In the case where use of the connecting sleeves, the first phase of reinforcing bars are provided, for example by crimping, end cap engaging the cof- _f rabies concrete first phase; these end caps or sleeves are protected during casting by sealing plugs, for example made of plastic, and appear, after formwork removal, in the wall of the poured concrete, provided that they have remained well positioned during casting and hardening of the first phase concrete. The plastic shutters, by leveling the wall favor the location.

While these processes do not present notable problems in theory, the same does not apply in practice. In the case of connecting reinforcements, the folded ends are covered with concrete and it is necessary on the one hand to locate them, which is not always obvious, then to release them. With a jackhammer with all the risks of steel injury that this implies. The same difficulty of research and release can exist with the sleeves whose external surface can be covered with laitance of concrete. This difficulty is increased when the pouring wall is not planar, in particular in the case of walls molded into the ground. On the other hand, even when the connecting reinforcements or the sleeves have been properly positioned before pouring, there is always a risk of displacement during the various treatments that the concrete is made to undergo, such as vibration for example.

Furthermore, it is known to make reserves inside a formwork by fixing on the walls of the latter elements formerly constituted by planks of wood but which are increasingly replaced by panels of synthetic foam. such as polystyrene or polyurethane foam. Said panels are then removed or destroyed in order to allow contact with the best possible attachment between the first phase concrete and the second phase concrete.

The present invention is based on the idea that it is possible to use such panels to simplify, improve and properly control the installation of sleeves or connecting frames.

According to the present invention, the connecting panel, molded from synthetic foam, which can be fixed inside. of a formwork, is characterized in that it has a set of regularly distributed orifices.

In the case of sleeves crimped at the end of bars, the diameter of the circular orifices is substantially equal to the external diameter of the sleeves whose ends can thus be trapped during casting which prevents any risk of displacement. After formwork stripping, the foam panel appears distinctly and the sleeves can be easily located and rid of the plastic foam that surrounds them, for the connection of second phase reinforcements. Possibly., Said orifices can be blind so as to protect the interior of the sleeve during the pouring of the first phase concrete.

In the case where connection reinforcements are used, the orifices are approximately the same diameter as the connection reinforcements, their spacings being in accordance with that which is defined by the calculations. In this case and according to one of the characteristics of the invention, the panel has on one of its faces (that which is intended to be pressed against the formwork) substantially longitudinal grooves each of which corresponds with one or more orifices. Indeed, to obtain good adhesion of the panel to the formwork, it is desirable that the panel has a bearing face of shape corresponding to that of the formwork against which it is applied. The purpose of these grooves is to allow their insertion into the panel, after they have been folded, on the formwork side. The grooves have a depth of the order of diameter or several times the diameter of a connecting reinforcement. In order to avoid the superimposition of these, the grooves can be inclined relative to the longitudinal direction of the panel. The folded ends of the reinforcements are inserted into the grooves before fixing the panel to the formwork, the opposite ends projecting perpendicularly to the panel, after passing through it.

When it is desired that the connection reinforcements form loops, it is possible, as known in the art, to fold said connection reinforcements in a "U" shape. In this case, it is the unclosed loop formed by the core or transverse branch of the "U" as well as by a part of the wings which is folded a second time. perpendicular to the branches of the "U" and after this second folding inserted into one of the faces of the panel. In this case, the grooves take the form of an unclosed quadrilateral, two opposite sides of which open into two orifices in the panel. Before fixing the panel to the formwork, the reinforcements are slid into said panel so that the "U" comes to fit into the corresponding groove. The "U" is thus wrapped over most of its periphery by plastic foam which tends to close on the steel, therefore to coat it well, thereby protecting it from contact with concrete. This coating is increased by the pressure exerted on the face of the panel; when fixing it on the formwork. After formwork stripping, the _"U " is unfolded and forms a loop inside which the second phase concrete sets. The panel can be delivered with mounted link plates and these plates can also be molded with the panel, the loops being arranged in the vicinity of one of the walls of the mold.

• - La Fig.l, un panneau selon l'invention;
• - La Fig.₂ et la Fig.3 un exemple d'utilisation d'un panneau avec des manchons;
• - La Fig.4 une armature de liaison pliée en "U"
• - La _Fig.5, un panneau après coulée du béton de première phase;
• - La Fig.6, une coupe selon la ligne VI-VI de la Fig.5 après dépliage des armatures et coulée du béton de seconde phase.

Other characteristics and advantages of the invention will appear during the description which follows of particular embodiments, given only by way of nonlimiting examples, with reference to the figures which represent:

• - Fig.l, a panel according to the invention;
• - Fig. ₂ and Fig.3 an example of using a panel with sleeves;
• - Fig.4 a connecting frame folded in "U"
• - The _F IG.5, a panel after casting of the concrete first phase;
• - Fig.6, a section along line VI-VI of Fig.5 after unfolding the reinforcements and pouring the second phase concrete.

In Fig.l, the panel 1, intended for holding sleeves has a set of aligned holes 2, regularly spaced, the distance between the outermost holes and the side edges of the panel is preferably equal to half a step , so as to allow an assembly of panels by juxtaposition while preserving the regularity of distribution of the reinforcements. Of course, the panels 1 can be assembled vertically or horizontally.

As shown in Fig. ₂ which is a section through a vertical plane of a concrete structure after pouring of the first phase concrete 9, the panel 1 is fixed to the formwork 3 by means of points, for example, and the end of the sleeve 4 is inserted into one of the orifices 2 of the panel 1 which, in the example shown, is arranged horizontally. The sleeve 4 has been previously crimped onto the end of a frame 5 which it is proposed to connect to the frame 6 of the second phase concrete. To this end, a sleeve 7 is also crimped at the end of the frame 6, the two sleeves 4 and 6 being themselves mechanically connected by a connector 8 with double reverse thread. In Fig.2, only the sleeve 4 is held in an orifice 2 of the panel 1. During the pouring, the concrete 9 comes to surround the bar _' s, the sleeve 4 and the panel 1 without being able to penetrate inside the muff. Of course, a set of bars 5 extend parallel to the bar 5 shown. The concrete then takes the conformation which results from the form of the formwork. After formwork stripping, a more or less smooth surface 10 appears on which non-concreted zones are formed, formed by one of the faces of the panels 1. Clearance of the ends of the sleeves, immediately identified, is very easily obtained by destroying or removing the panel 1. It is moreover possible, in order to increase the bonding of the second phase concrete on the first phase concrete, to provide on the face of the panel 1 opposite the formwork a surface relief, for example by means of 'a fence. The frame 6 is then connected to the frame 5 as described above and the pouring of the second phase concrete can occur, the hollow released by the destruction of the panel being filled with the concrete 11 of the second phase. Fig.3, shows in section through a vertical plane, the assembly performed. It will be noted that the panels according to the invention play the role of templates which makes it possible to obtain an extremely precise positioning of the reinforcements.

Panels of the same structure can be used for positioning connecting reinforcements. In this case, however, on the one hand the diameter of the orifices is smaller than previously and grooves must be provided on the face applied against the formwork. Indeed, in order to avoid the penetration of concrete between the formwork and the panel, it is desirable that one of the faces of the latter have the same shape as that of the wall against which it is applied. It is moreover possibly possible to interpose between the panel proper and the inner face of the formwork, receiving the panel, a kind of cap or cover which ensures good contact between the panel and the formwork. In practice, the shape of the internal wall of the formwork is not always flat and the invention can of course be applied to the case where this wall has the shape of a cylindrical sector.

If the frames are simply folded once at 90 °, the grooves may consist of simple substantially longitudinal grooves, into which the abovementioned orifices open, said grooves being inclined relative to each other to avoid overlapping.

It is also known to use as connecting reinforcements bars folded in "U", such as that which is shown in Fig.4. After a first folding, the bar 12 has two parallel strands 13 and 14 joined by a loop 15. A second folding brings the loop 15 in a vertical position or more exactly in a plane perpendicular to the plane of the strands 13 and 14. Of course, all these folds are carried out with radii of curvature in accordance with the regulations in force in the field. In parallel, an arc-shaped groove 16 is formed during the molding of the panel, so that the loop 15 can be completely inserted into the panel. All the loops 15 are thus integrated into the panel and the contact between the face 18 thereof and the formwork is excellent.

The orifices 2 and the grooves 16 can be obtained directly by overmolding the frames. These are arranged in the mold, the folded loops being against the bottom of the mold so as to be easily identifiable and unfoldable after stripping. Figs. 5 and 6 represent a mode of use of connection reinforcements, molded into a panel or introduced into it after molding. The process of implementing such a panel is substantially identical to the previous one. The connecting reinforcements 12 folded twice so as to form a loop 15 perpendicular to the strands 13 and 14 are slid into the panel 1 if they have not been molded therewith. The panel 1 is then fixed in an appropriate position on the formwork 3 so that the strands 13 and 14 overlap with the reinforcements of the first phase concrete (not shown in FIGS. 5 and 6). The face 19 of the panel 1, may have surface reliefs to improve the attachment of the second phase concrete 11 to the concrete 9, in the cavity left free after disappearance of the panel.

Fig.5 shows in vertical section the arrangement of the connecting reinforcements after pouring the concrete 9. Once the formwork 3 removed, the loops 15 are unfolded, the panel ₁ then being destroyed which is not a problem given its friability . After unfolding, the loops 15 occupy the position shown in Fig.6, which is a section through a horizontal plane along the line VI-VI of Fig.5. The loops anchored in the concrete 9 by their strands 13 and 14 can constitute the reinforcements of the second part of the structure if the latter is of relatively small dimension or can be connected by any suitable means such as covering, for example, to a second set of reinforcements integrated into the second part of the structure produced by pouring concrete 11 from the second phase.

It goes without saying that modifications can be introduced, in particular by substitution of equivalent technical means, without departing from the scope of the present invention.

Claims (8)

1 ° Reinforcement connection panel for reinforced concrete, made by molding synthetic foam and can be fixed inside a formwork, characterized in that it has a set of orifices regularly distributed for the introduction on at least part of its thickness of reinforcement ends. ₂ ° Panel according to claim 1, characterized in that the frames being provided with substantially cylindrical sleeves, the aforesaid orifices are blind holes. 3 ° Panel according to claim 1, characterized in that the face intended to be applied against the formwork has grooves of depth at least equal to the diameter of one. connecting frame. 4 ° Panel according to one of claims 1 or 3, characterized in that connecting armatures are slid into the orifices and grooves, before fixing to the formwork. 5 ° Panel according to one of claims 1 or 3, characterized in that the reinforcements are introduced into the panel during molding thereof. 6. Panel according to any one of claims 1, 3, 4 or 5, characterized in that the connecting reinforcements being constituted by bars bent in a U, the lower part of the U then being folded perpendicular to the parallel strands, the orifices above are grouped in pairs, each pair being connected on one side by an arc-shaped groove inside which is housed the loop of the U. 7. Panel according to any one of the preceding claims, characterized in that the face opposite to the formwork has reliefs intended to improve the attachment of concrete in the reserve formed by the panel. 8 ° Reinforced concrete construction poured in at least two phases or using prefabricated elements in which at least one panel is used according to any one of the preceding claims.

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