FR2650614A1 - REINFORCEMENT ASSEMBLY FOR REINFORCED CONCRETE PRODUCTS, METHOD AND INSTALLATION FOR THE PRODUCTION THEREOF - Google Patents

Abstract

The invention relates to an assembly of reinforcing elements for reinforced concrete products, this assembly comprising a plurality of spaced-apart rigid transverse reinforcing elements (12) and at least two longitudinal flexible elements (14) joined to the transverse reinforcing elements in order to keep them spaced apart at chosen intervals. An assembly is thus obtained which may be easily packaged. The invention also relates to a method and a device for manufacturing this assembly of reinforcing elements.

Description

Set of reinforcements for reinforced concrete products, process and installation

  The invention relates to a set of reinforcements for reinforced concrete products, as well as a method and an installation for

its manufacture.

  To reinforce the concrete plates, it is known to use a "welded mesh" consisting of two layers of steel reinforcement, these two layers being superimposed in two perpendicular directions and being assembled together

by solder points.

  Reinforcements of this type are well suited for concrete products in which the mechanical forces to be taken up are made in two perpendicular directions, which means

which are bidirectional.

  On the other hand, reinforcements of this type have the drawback of being ill-suited to concrete products in which the mechanical forces to be taken up are made in one direction (unidirectional forces) or else in which the forces are already taken up in one direction by other frames. This is particularly the case for prestressed concrete products, which include reinforcements or steels of

  prestressing already taking up efforts in one direction.

  In these particular cases, it appears that one of the two nap-

  pes of reinforcement of the welded lattice has the sole function - that of maintaining the other ply at a given distance. he

  - as a result, one of the two layers of reinforcements is oversubscribed -

  dante from the point of view of the mechanical resistance of the product

in reinforced concrete.

  Another disadvantage of conventional welded mesh is that they are very bulky during transport, 2-

  handling and storage. This drawback is re-

  also found in the case where the welded mesh is pre-

  feels in the form of panels. that in the case where the trellis-

  Welded lily is in the form of rolls. In the latter case, the rigidity and the thickness of the reinforcements placed along the length of the roller does not make it possible to optimize or

the volume, nor the placement.

  In addition, conventional welded mesh is generally-

  prefabricated in the factory, by means of special installations

  particularly heavy, and generally according to dimensions

  predetermined, which does not allow the user to opti-

  bet the quantities of steel, also requires cuts

  during the er. place and requires moreover

  heavy handling, several panels are generally

  necessary for the same application.

  This results in loss of material and of labor time.

  Finally, conventional welded mesh has the other disadvantage

  often presents flatness defects and it is then necessary, taking into account the rigidity of the steels connecting the reinforcements, to make close fastenings during

  the installation of the reinforcement ply.

  The object of the invention is in particular to provide a set of fittings suitable for overcoming the drawbacks mentioned above.

  It is also an object of the invention to provide a set of

  reinforcement wheat intended especially for products

  in reinforced concrete in which the mechanical forces to be resumed

  dre are done in one direction or in which the mechanical forces are already taken in one direction

by other frames.

  It is, in particular, an object of the invention to provide such a set of reinforcements intended especially for prestressed concrete products. The invention also aims to provide such an assembly

  of armature which is not bulky in transport, in the manu-

  storage and, which can be easily cut during installation and which does not present any defect

flatness.

  The set of reinforcements for reinforced concrete products according to

  the invention comprises a multiplicity of transverse reinforcements

  dirty rigid spaced from each other and at least two

  longitudinal flexible elements linked to transverse reinforcement

  dirty to keep them spaced at selected intervals. In a preferred embodiment of the invention, the

  transverse reinforcements are general steel bars-

  rectilinear held parallel to each other by

flexible elements.

  This assembly is then presented, once spread out, in the form of a sheet formed by said steel bars and said

  flexible connecting elements, linked to the bars at each

  section. The width of the ply is then defined by the cutting length of the steel bars while its length can be adapted to its use, since it suffices to

  cut the flexible elements to the desired length. Space-

  ment or interval -between bars can be constant 'or

  variable, depending on the mechanical forces to be taken up.

  The set of reinforcements of the invention thus offers various significant advantages compared to conventional welded mesh. In the particular case where the transverse reinforcements are steel bars, the assembly can be packaged under

  shape of a roll. This roller facilitates transport,

  that, for the same quantity of useful reinforcements, it occupies less volume than a welded mesh. Indeed, flexible elements occupy less volume than steel elements

  they replace and are of a lower weight -to these last-

  deny. They also allow the web to be wound on a small diameter drum. Such packaging consequently facilitates storage and handling at the place of use. In addition, the installation of the set of reinforcements

  is simplified since it suffices to unroll the arma-

  tures, the flexible elements exerting no resistance to unwinding. After the reinforcement assembly has been unrolled, the flexibility of the connecting elements allows the reinforcements to be deposited by gravity in a plane, which limits or

removes fixings.

  This results in significant labor gains.

  Furthermore, the geometry of the sheet (length, width, pitch between transverse reinforcements) can be perfectly

  adjusted to a place of use and mechanical resistance

  what you want. This optimizes the amount of steel

  used and decrease losses.

  Another advantage of the invention results in the fact that the longitudinal flexible elements are of lower cost

to the steels they replace.

  Finally, the reinforcement assembly of the invention can be made

  bricked with simpler equipment than necessary

  the manufacture of a conventional welded mesh.

  The set of reinforcements of the invention can be produced

  also with non-rectilinear elements, in which case- the set-

  ble, unrolled, is no longer in the form of a sheet. In this case, the assembly can be packaged, not in the form of a roll, but in the form of a

  accordion structure, in which the longitu-

  dinales are close to each other.

  The flexible elements used in the manufacture of the set of reinforcements according to the invention can be formed from wire, twine, adhesive tapes, strips in

  metal or plastic, and the like.

  In a preferred embodiment of the invention, each

  that flexible element is formed from at least one sheet

  bacon made of plastic, especially polypropylene. Avan-

  tagging, each flexible element includes two superimposed strips welded to each other punctually

  and other of each frame. For example, one of the sheets-

  bacon is shooting, while the other is shooting or punctual.

  In another aspect, the invention relates to a method of manufacturing the above-mentioned assembly of armatures, this method comprising the operations consisting in:

  - unwind equal lengths of flexible elements from

  firing from a feed to bring them parallel between

them at a liaison post, -

  bring the reinforcements one by one transversely to the flexible elements at the level of the connection station, - link a reinforcement to the flexible elements at the level of the connection station, - advance the flexible elements which take with them the previously linked reinforcement , and

  - repeat the above operations for the other arma-

  tures. The bonding process obviously depends on the nature of the flexible elements used and can call in particular

  knotting, gluing, ultrasonic welding or heated blade

  age, stapling, etc. In the preferred embodiment of the invention, where each flexible element is formed from at least one plastic strip, the bonding process can

  use ultrasonic welding or heating blade.

  In the particular case o each flexible element is formed from two plastic straps, namely a lower strap fed from an unwinder

  and an upper strap fed from another

  roller, we weld the two strips to each other

  on each side of the reinforcement to be fixed.

  This welding is preferably carried out by means

  ultrasound provided at the link station.

  After connection of a reinforcement, for example by welding, it suffices to advance the reinforcement ply by one step by unwinding the flexible elements, the value of this step being able to be adjustable. Then, the sheet formed can be simply

wound on a drum.

  The invention relates, in another aspect, to an installation

  for the manufacture of the aforementioned set of reinforcements.

  This installation essentially comprises: -5 - a liaison station,

  - supply means to supply equal lengths

  the flexible elements and bring them parallel to each other at the connection station, - a distributor of reinforcements suitable for bringing the reinforcements one by one transversely to the flexible elements at the connection station, and

  - means of advance to advance the pupils one step

  flexible elements which take the reinforcement with them beforehand

linked to the connecting elements.

  According to another characteristic of the invention, the connection station is provided with a connection head in correspondence

  of each flexible element to be linked to the reinforcements.

  In the case where each flexible element is formed from at least one strip of plastic, in particular polypropylene, each connecting head is then provided

  welding means, for example ultrasonic.

  -In the preferred embodiment of the invention, in.

  which each flexible element is formed from two plastic strips, * the supply means comprise, for each flexible element, two unwinders suitable for receiving respectively a lower strip roll and an upper strip roll. this allows

  to superimpose them. two strips before welding, around

  each time the reinforcement to be linked. Welding is then carried out on either side of this reinforcement on

a limited length.

  According to another characteristic of the installation of the

  vention, this includes, associated with each unwinder, a brake controlled by a pivoting lever provided with a return pulley around which the strap is wound, so that the brake is released when a traction is exerted by the strap, while the brake is blocked

when this traction ceases.

  Advantageously, the installation includes four pairs of unwinders, which allows. to fix four flexible elements,

  each formed by the superposition of two strips.

  The means to advance the installation of the invention.com-

  advantageously take horizontal translation pliers

  each suitable for gripping a flexible element downstream

  of the link station to advance the whole step.

  Advantageously, the installation comprises a fixed stop and an adjustable stop associated with each clamp to adjust

  at will the step between two successive transverse reinforcements

sives.

  In the case where the installation is used for manufacturing -

  tion of a set of frames formed from rectilinear transverse frames, it further comprises a receiving drum on which is wound the sheet thus formed.

  In the description which. follows, given only as

  example, reference is made to the accompanying drawings, in which

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  - Figure.1 is a top view of a set of armatu-

res according to the invention;

  - Figure 2 is a schematic side view of an installation

  lation according to the invention; - Figure 3 is a partial schematic sectional view showing the connection of a transverse frame by means of a flexible element consisting of two superimposed plastic strips;

  - Figure 4 is a partial side view of the installation

tion of Figure 2;

  - Figures 5A to 5D show different successive phases

  operating ves of the installation of Figure 4;

  - Figure 6 shows a strip dispenser forming part-

  tie of the installation of figure 2;

  - Figure 7 shows a detail of the installation of the fig-

re 2;

  - Figure 8 shows schematically a set of arma-

  tures according to the invention in which the frames are non-rectilinear; and

  - Figure 9 schematically shows another set of ar-

  according to the invention in which the reinforcements trans-

  versales are non-rectilinear and have a closed contour.

  We first refer to FIG. 1 which shows a set of

  ble of reinforcements according to the invention, generally designated by the reference 10. This assembly comprises a multiplicity of rigid transverse reinforcements 12 spaced from one another which, in the example shown, are bars in

  steel of the same length arranged parallel to each other.

  The assembly 10 further comprises flexible elements

  14 which are four in number in the example shown. Each frame 12 is thus linked to the four

  flexible elements 14 by four nodes 16.

  By way of example, each of the frames 12 is a steel bar with a diameter of four or five millimeters and a length of 2.40 meters. The interval i (or not) between two consecutive reinforcements 12 can be adjustable from 50 to 50 millimeters in a range comprised, for example,

between 100 and 450 millimeters.

  In the example, the flexible elements 14 extend parallel-

  between them, the distance d separating two elements 14

  consecutive being equal to 60 centimeters.

  In the example shown, each flexible element is formed by two strips of plastic material with a width of

  millimeters, these two strips being spot welded-

  between them, as we will see later.

  We now refer to Figure 2 which shows schematically

  only the installation for manufacturing a set of reinforcements according to the invention. This installation comprises a connection station 18 comprising a fixed frame 20 forming a horizontal table 22 with which cooperate four connection heads 24 intended to ensure the connection of each frame 12 with the flexible elements 14. In the example, each flexible element 14 (only one of which is visible in FIG. 2) is formed by the assembly of two strips,

  namely a top strip 14A and a bottom strip

  laughing 14B, these two strips coming respectively

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  of one. upper roller 26A and a lower roller 26B carried respectively by an upper unwinder 28A and a lower unwinder 28B. The installation thus comprises four upper unwinders 28A and four lower unwinders 28B.

  The installation further comprises a distributor 30 comprising

  both a movable frame 32 provided with wheels 34 and having a table. inclined 36 forming a store and intended to present the transverse bars 12. The latter are then brought one by one into the limited space between the four pairs of strips 14A, 14B immediately upstream of the connection heads 24, relative to the direction of movement

straps (arrow F).

  In the example, the strips 14A and 14B are made of plastic, in particular polypropylene; and the four heads 24 are welding heads intended to ensure the mutual welding of the four pairs of strips on either side

  a transverse reinforcement, as shown below in reference

Refer to Figure 3.

  However, the general principle of installing the fig-

  re 2 could be used for other types of flexible elements, the connection heads 14 not necessarily being

welding heads.

  The four pairs of strips 14A and 14B are moved step by step in the direction of arrow F, while a transverse reinforcement 12 is brought to the table 22 and below the welding heads 24 by means which will be described later. These heads 24 are then moved vertically downward to ensure the connection of the four pairs of strips which keep the corresponding frame 12 trapped. This gives a sheet which can be

  wound on a receiving drum 36 (Figure 2).

  As shown in Figure 3, the upper strip 14A comes

  wrap around the frame 12 and is spot welded-

  ment to the lower strip 14B by two welding zones

  38 and 40 arranged on either side of the frame 12.

  For example, these two zones 38 and 40 can each

  extend over a length 1 of the order of 10 millimeters.

  Thus, for strips of 10 millimeters in width, two welding zones are obtained, each corresponding to

  a 10-millimeter square.

  We now refer to FIG. 4. The table 36 defines an inclined plane of curved shape extending from an upstream end 42 to a downstream end 44, the end

  downstream 44 located at a level lower than that of the extreme

  mite upstream 42. Above table 36 is placed a guide

  46 provided with a lower surface 48 of curved shape available

  sée opposite a part of the table 36. The table 36 -and the guide 46 thus define a magazine suitable for receiving a plurality of transverse bars 12 placed one next to the other. A horizontal bar 50 is placed upstream of the guide 46 to prevent the passage of two crossed frames 12. The table 36 and the guide 46 thus form a store in which the frames 12 are stored

  side by side and parallel to each other and horizontally.

  This store is practically tangent to the vertical in its lower part which is adjacent to the end 44. Under the store thus formed are provided four extractor drawers 52 animated by a translational movement

  horizontal, the drawers being moved synchronously.

  The drawers 52 are provided with respective notches 54 -which, when the drawers are in the rear position (FIG. 4), receive a frame 12. The drawers 52 are movable in synchronism and suitable for bringing a frame 12 into the horizontal space 56 limited between an upper plate 58 and a lower plate 60, this space 56

  leading to an eclipsable stop 62.

  The operation of the part of the installation shown in Figure 4 will now be explained with reference to Figures 5A to 5D. During their advance movement, as represented by the arrow in FIG. 5A, the drawers 52 drive an armature 12 and close the outlet of the magazine formed by the table 36 and the guide 46. During this movement,

  the frame 12 is guided between the plates 58 and 60.

  The frame 12 is then brought to the eclipsable stop 62 (FIG. 5B) and is then blocked between this stop 62 and each drawer 52 in the position of connection to the strips 14A, 14B. The welding heads 24 are then moved in synchronism vertically downwards (FIG. B) to make the connection of the four pairs of strips

(14A, 14B) around the frame 12.

  When this operation is finished, the welding heads 24 are moved vertically upwards and the drawers

  moved horizontally backward (Figure 5C) to.

  return to their initial position (Figure 5D) where they can

  wind welcome a new frame 12 in order to start again

the same cycle as before.

  We now refer to Figure 6. Each of the. un-

  their, for example the unwinder 28A for receiving the roller 26A, is formed of two flanges secured to a cylindrical core 64 coaxial with the axis 66 of the unwinder. Each unwinder, for example 26A, is associated with a brake 68 constituted by a lever 70, one end of which 72 is

  pivotally mounted around an axis 74 and the other of which.

  end 76 carries free rotation a deflection pulley 78 on which the strip 14A is wound, the latter then passing around a deflection pulley 80 rotatably mounted around a fixed axis 82. The lever 70 has an intermediate part curved 84 capable of rubbing against the core 64 to slow down the rotation of the unwinder. When the pulley 78 and the lever 70 are in the low position shown in FIG. 6, the curved part 84 of the lever, which forms a brake, is supported on the core 64 and

  the strip roll is braked in rotation.

  When traction is exerted on the strip 14A, the latter raises the pulley 78 and the lever 70, which unlocks

  the brake and releases the strip roll.

  When the desired length of strip has been pulled, the pulley 78 and the lever 70 descend and the strip roll is again braked, the tension of the strip being substantially the same after each unwinding operation. In the example shown, the installation comprises four

  unwinders 28A and four unwinders 28B. The four leaves

  lower strips 14B arrive at the welding station passing under the table 36 (FIG. 2) and therefore under the frame to be fixed, while the four upper strips 14A arrive above the frame 12 to be fixed. The straps are

  guided and positioned using eight 80 pulleys.

  As shown in Figure 7, the frame 12 and the four strips 14A and the four strips 14B are positioned at the connecting station. The four welding heads 24 are then moved in synchronism vertically towards

  the bottom to weld the four pairs of sheets

  bacon. For this, the lower part of each welding head is provided with an imprint 86 having the same shape as the armature, so that each welding head can span the armature and weld the two strips together.

  and other of it, as shown previously in the fig-

re 3.

  Advantageously, the welding heads are of the ultra-

  sound to cause the localized fusion of the material

  tutive of the straps - at their interface. This fusion, which is followed by a holding time of the welding head after the vibration stops, ensures the welding

of the four pairs of straps.

  As shown in FIG. 7, the installation also comprises step-by-step advance means comprising four clamps 88 with horizontal translation. Each clamp is formed by a

  upper jaw 88A and a lower jaw 88B and are pro-

  pres to each grasp a strip 14 downstream of the fixing station to advance the whole of a step in the direction of the arrow F. The respective jaws of the clamps are brought together to poz come. each time grip a strip and the clamps are then moved in synchronism horizontally and 'to the left of the

  Figure 7 along a length corresponding to the desired pitch.

  The movement of movement of the clamps 88 is limited by a fixed stop 90 close to the welding heads and by an adjustable stop 92 on the other side. This adjustable stop

  allows to adjust the pitch between two successive reinforcements.

  From the start of the welding operation, the pliers. 88 come

  must be placed near the welding heads and their jaws remain

  Pectives are activated to pinch the strips and keep them firmly in position once the operation of

welding completed.

  When the operation of. welding is complete, the welding heads are raised, the stop 62 (figure 4) is eclipsed and the clamps 88 advance to the left of figure 7 by driving the sheet of reinforcement formed and unwinding

  the strips of the value of one step.

* From the start of the next welding operation, the clamps 88 open and are positioned next to the heads

welding.

  On leaving the installation, the sheet thus formed first passes around a deflection roller 94, then around another deflection roller 96 to wind around the

  drum 36, the latter being suitable for being rotated

  tion via a transmission 98 and a motor 100. The roller -96 is guided in vertical translation, two sensors (not shown) detecting the high and low positions of this roller. When the roller 96 is in the low position, the motor 100 for driving the drum 36 starts, which causes the winding of the

  tablecloth until the roller 96 is in the high position.

  During the winding of the sheet around the drum 36,

  the latter is animated by an alternative movement of transla-

  tion on its axis in order to avoid overlapping the sheets

  bacon. Reference is now made to FIG. 8 which shows a set of reinforcements according to the invention, comprising rigid transverse reinforcements 112 which are not rectilinear connected together by three flexible strands 14. This set can be

  packaged in the folded state in the form of an accordion.

  We now refer to Figure 9 which shows another

  set of reinforcements according to the invention, this set includes

  from non-rectilinear transverse reinforcement 212. In

  example, these frames are folded to form a con

  tower. closed generally rectangular, these. reinforcements being connected by three flexible elements 14. As in the case

  of figure 8, this set of reinforcements can be condi-

  tione, in the folded state, in the form of an accordion structure.

  The set of frames according to the invention finds an applica-

  particular in the case of precast concrete products

  traint, especially in the case of precast concrete slabs

  traint which include prestressing steels arranged parallel to each other. It then suffices to unroll a sheet of reinforcements according to the invention so that the rigid transverse reinforcements are perpendicular

  to the direction of prestressing steels.

  The invention is susceptible of numerous variants. For example, the bars forming the transverse reinforcement, instead of being precut to the desired length, could be erected and cut by the installation from

steel coils.

Claims (19)

Claims.   1. Set of reinforcements for reinforced concrete products, charac-   terized in that it comprises a multiplicity of rigid transverse reinforcements (12, 112, 212) spaced from each other and at least two longitudinal flexible elements (14) linked to the transverse reinforcements to keep them spaced at selected intervals.   2. Set of armatures according to claim 1, charac-   in that the transverse reinforcements (12) are bars-   generally rectilinear steel res kept parallel-   between them by the flexible elements (14), which   puts to condition the whole in the form of a roll.   3. A set of frames according to claim 1, character-   in that the transverse reinforcements (112, 212) are non-rectilinear elements, which makes it possible to condition   the whole in the form of an accordion structure.   4. Set of frames according to one of claims 1   to 3, characterized in that the flexible elements (14) are formed from wire, twine, adhesive tapes,   metal or plastic straps, and the like.   5. Set of frames according to one of claims 1   4, characterized in that each flexible element (14) is formed from at least one strip (14A, 14B) of material   plastic, especially polypropylene.   6. A set of frames according to claim 5, character-   se in that each flexible element (14) comprises two bacon strips (14A, 14B) welded punctually to each other and the other of each frame (12).   7. A set of frames according to claim 6, character-   dried in that one of the strips (14B) is continuous, while   that the other strip (14A) is continuous or punctual.   8. Method of manufacturing a set of reinforcements according to   one of claims 1 to 7, characterized in that it   includes the operations consisting in: - unwinding equal lengths of the flexible elements (14) i0 from a supply to bring them parallel to each other at a connection station (18), - bringing the reinforcements (12) one by one transversely with flexible elements. (14) at the connection station (18),   - link a frame (12) to the flexible elements (14),   - Advance the flexible elements (14) one step   take with them the frame (i2) previously linked, and -   - repeat the above operations for the other arma-   tures. 9. Method according to claim 8, characterized in that each flexible element (14) is formed from two   plastic straps, namely a top strip   laughing machine (14A) supplied from an unwinder (28A) and a lower strip (14B) supplied from a lower unwinder (28B), and in that the two strips are welded together other punctually (38, 40) on both sides of the frame (12) to be linked.   10. Method according to claim 9, characterized in that the two strips are welded (14A, 14B) by welding ultrasonic.   11. Installation for the manufacture of a set of armatu-   res according to one of claims 1 to 7, characterized in   what it includes: - a connection station (18), - supply means (28A, 28B) for supplying   equal lengths of flexible elements (14) and bring them together   parallel to each other at the liaison station (18),   - a distributor (30) of armatures suitable for bringing the armatures   tures (12) one by one transversely to the flexible elements (14) at the connection station (18), and - advancing means (88) for advancing the flexible elements (14) by one step, which lead with them the frame. (12)   previously linked to the connecting elements.   12. Installation according to claim 11, characterized in that the connection station (18) is provided with a connection head (24) corresponding to each flexible element (14) to link to the reinforcements (12).   13. Installation according to claim 12, characterized in that each flexible element (12) is formed from at least one strip (14A, 14B) made of plastic, in particular polypropylene, and in that each connecting head ( 24) is provided with welding means., For example ultrasonic. -   14. Installation according to claim 13, characterized in that each flexible element (14) is formed from two strips (14A, 14B) of plastic material and "in that the supply means comprise, for each   flexible element, two unwinders (28A, 28B) suitable for receiving   see respectively two strip rolls (26A, 26B).   15. Installation according to claim 14, characterized in that it comprises, associated with each unwinder (28A,   28B), a brake 68 comprising a lever (70) provided with a   return link (78) around which the strip is wound (14A) so that the brake is released when a traction   is exerted on the strip and is blocked when the trac- tion ceases.   16. Installation according to claim 15, characterized in that it comprises four pairs of unwinders (28A, 28B), which allows to link four flexible elements (14) each formed by the superposition of two strips (14A, 14B).   17. Installation according to one of claims 11 to 16,   characterized in that the advance means comprise   pliers (88) with horizontal translation suitable for gripping each   cune a flexible element (14) downstream of the connection station   (18) to advance the whole step.   18. Installation according to claim 17, characterized in that it comprises a fixed stop (90) and an adjustable stop (92) associated with each clamp to adjust at will.   the step between two successive frames (12).   19. Installation according to one of claims 11 to 18,   in which the transverse reinforcements are generally rectilinear, characterized in that it comprises a drum   receiving (36) driven by an electric motor (100).