FR2467271A1 - PROCESS FOR MAKING AN ANCHOR FOR CONNECTING TWO REINFORCED CONCRETE ELEMENTS - Google Patents

Abstract

The reinforcing steel bars (5) bent at right angles are laid, by means of their parts which are to be bent out, on a magnetic plate which is supplied with current. A thermally deformable plastic film (3) is applied over the parts which are fastened in this manner and are to be bent out. The plastic film is subjected to heat treatment by specifically directed hot-air jets. As a result of the heat treatment, the film (3) becomes soft and applies itself to those parts of the reinforcing steel bars (5) which are to be bent out. The parts which are to be bent out are encased by the film (3) in a partially tilting manner. Finally, the film (3) is subjected to a shock-type cooling by cooling air. The costs of the anchoring produced in such process steps are low in comparison with the known production processes. After the completed concreting of the anchoring and the removal of the film (3), those parts of the reinforcing steel bars (5) which are to be bent out can be bent out simply and without any time loss.

Description

 The invention relates to a method for producing an anchorage consisting of several reinforcing bars, for connecting reinforced concrete elements in which each reinforcing bar is first folded substantially with straight anal to define a part to to coat in the concrete of a main wall and a part to be unfolded after setting of the concrete, the parts to be unfolded reinforcing bars being arranged tight against each other and the parts of the reinforcements embedded in the concrete being disposed at a distance determined from each other.

To rationally execute the connection to a main concrete wall of intermediate walls, stair treads or intermediate concrete floors, it is known from Swiss Patent 562,376 to have the frames folded at right angles, one part of which, on one side of the right angle, forms a stirrup to be embedded in the main wall and the other part of which forms two free arms to be unfolded after concreting, so as to place the free arms in a formwork form a gutter and fill it with polyurethane foam. The hardened foam then forms a mass retaining the arms of the frames.

To be able to extend the arms out of this mass after setting the concrete retaining the stirrups, this mass must be removed by scraping, which is straightforward and painful.

In addition, the manufacturing costs are quite worn out.

 The subject of the present invention is a method of making an anchor serving for connection to concrete elements, the anchor consisting of several reinforcing bars, in which the parts to unfold reinforcements, after the concrete has completely set coating the other parts back frames can be unfolded without loss of time. Thus, the manufacturing costs of a tl ancraae are reduced compared to other known production methods.

In accordance with the present invention, this result is obtained by the fact that the reinforcing bars folded at right angles are held in a bundle, and that on the parties to deny reinforcing bars maintained in a seal, there is arranged a sheet of plastic material def heat- able on the side opposite the parts to be concreted, until it is applied tightly on the parts to be unfolded and that it partially wraps them like a clip , after which the sheet is subjected to sudden cooling.

 An anchor prepared in this way is easily transportable.

 Advantageously, the heat treatment of the plastic sheet is obtained by blowing hot air directed or channeled over the section of the sheet covering the parts to be unfolded reinforcement bars.

 The description which follows, with reference to the appended drawing, given by way of nonlimiting example, will make it clear how the invention can be implemented.

Figure 1 is a sectional view of a bundle of reinforcing bars placed against a magnetic plate with a sheet placed on it,
FIG. 2 is a top plan view of the assembly shown in FIG. 1, and
Figure 3 is a sectional view of the parts to be folded rebars, which are welded together by points.

The anchorage serving as a connection of reinforced concrete elements is made up of several reinforcing bars 5 which are folded back substantially to 900 to form a part to be embedded in the concrete of a main partition and a part to be unfolded after setting the concrete of the anchor. Advantageously, each frame is folded up in the shape of a stirrup, the two arms 5h of the stirrup being folded substantially 900 from the spacer 5a. But it is also possible that each reinforcing iron 5 is simply folded to the right anal without forming a stirrup; in this case two series of reinforcing bars 5 are used.

 The frames 5 are assembled in a bundle, the parts to be unfolded being arranged tight against one another and the parts to be embedded in the concrete being arranged at a certain distance from each other. To rigidly maintain the bundle formed by the reinforcing bars, the parts to be folded out of the frames 5 are placed on a magnetic plate 1, which has slots 6, into which the parts to be coated are introduced. The parts to be unfolded are thus arranged in series against each other. The magnetic plate 1 is tensioned to rigidly hold the plates against each other.

 Instead of using a magnetic plate to maintain the beam formed by the reinforcements, one can use a welding, the parties to be folded arranged one against the other being welded together by points to keep them in contact. On the parts to be folded armatures 5 held in bundles in this way, is then brought on the side opposite to the parts to be concreted a plastic sheet 3 thermally deformable. The plastic sheet can advantageously be a PVC sheet which has a maximum thickness of 2mm. It can be placed at a certain distance from the surface of the folded parts or be placed directly on them. The plastic sheet 3 is reheated until it tightly presses against the parts to be folded and partially envelops them. It must result from the partial wrapping by the sheet 3 of the parts to be folded up a clip effect, so that , during transport, the sheet remains unmovable on the frames. Consequently the sheet 3 is exposed to sudden cooling.

The heat treatment of the sheet 3 can be carried out in different ways. Advantageously, it is obtained by blowing hot air directed precisely on the section of the sheet 3 covering the frame parts to be folded.

However, the application of the sheet 3 on the reinforcements 5 can also be obtained by thermal radiation, for example by elements with heating resistance. The treatment can also be obtained by infrared radiation. During the heat treatment, the sheet 3 can also be applied by a pressure plate 8.

 We will now explain in more detail the different successive operations shown diagrammatically in FIG. The plastic foil 3 is placed by its edges on a fixed base 2 and on a stationary base 2a and is held by means of a blank holder 4. Depending on the width required for the sheet 3, the mobile base 2a can be moved laterally in the direction of arrow A. The current of hot air concentrated on the sheet 3 causes it to be applied to the parts to be folded over of the reinforcements 5. Depending on the distance separating the sheet 3 from the surface of the reinforcements, at at the start of the heat treatment, edges of various heights can form (see the solid line representing the stretched sheet) which, during concreting, come to apply against a formwork which is not shown, so that between the formwork and anchoring there remains an empty volume. When the difference between the two series of irons to be folded is too large, an additional base 7 can be provided between the two series, so that the sheet 3 comes to apply there during the heat treatment and forms a support at this point. the height of the edges.

Then the sheet thus deformed is suddenly cooled by cold air so as to stiffen in this shape. It is quite possible to make the vacuum act on the other side of the sheet 3, from the magnetic plate 1.

 Perforations can be provided on both sides of the section of the sheet to be applied to the parts to be folded out of the frames 5. Instead of perforations, tear-off wires can be provided at these locations.

The sheet 3 which, after the setting of the concrete of the reinforcing parts 5 to be coated, is torn from the parts to be folded, can be removed from the parts to be folded, better and faster by the perforations or by the use of tearing threads.

The manufacturing costs of the anchor produced according to the method described above are much lower than in the production of known anchorages of this type. The bundle consisting of reinforcing bars with the plastic sheet applied on it can be transported without problem.

After the concrete has completely set the sheet can be torn from the concrete beam by a single tear over its entire length and separated from the reinforcing parts to be folded.

 It goes without saying that the embodiment described is only an example and that it would be possible to modify it in particular by substitution of technical equivalents, without departing from the scope of the invention.

 The invention having now been exposed and its interest justified by a detailed example, the applicant reserves exclusivity for the entire duration of the patent, without limitation other than that of the terms of the claims below.

Claims (7)

 1) Method for producing an anchor consisting of several reinforcing bars for connecting reinforced concrete elements, in which each reinforcing iron is first folded substantially at right angles to determine a part to be coated in the concrete d '' a main wall and a part to be unfolded after setting of the concrete, in which the reinforcing parts to be unfolded are arranged tight against one another and the reinforcing parts to be embedded in the concrete are arranged at a distance from each other others, characterized in that the reinforcements are held in a bundle and that there is a sheet of plastic material deformable by heat on the reinforcing portions held in bundle, on the side of the bundle opposite the portions to be coated in the concrete, and this sheet is heated until it is tightly applied to the reinforcing parts to be folded and partially wraps them like a clip, after which the sheet is subjected to sudden cooling. eu.  2) Method according to claim 1, characterized in that the armature parts to be unfolded arranged closely against each other are placed on a magnetic plate, which is supplied with electric current to maintain against each other the parts of frame to unfold. 3) Method according to claim 1, characterized in that the frame parts to be unfolded clamped against each other are spot welded to hold them together.  4) Method according to claim 1, characterized in that the thermal treatment of the sheet is carried out by blowing hot air directed on the section of the sheet covering the parts to be unfolded. 5) Method according to claim 1, characterized in that the treatment of the sheet is carried out by thermal radiation. 6) Method according to claim 5, characterized in that the heat treatment of the sheet is obtained by infrared radiation. 7) Method according to claim 1, characterized in that during the heating and cooling treatment, the sheet is fixedly held by its edges above the surface of the frame parts to be unfolded.