WO2008025894A2

WO2008025894A2 - Cellular slab comprising at least one lifting ring

Info

Publication number: WO2008025894A2
Application number: PCT/FR2007/001393
Authority: WO
Inventors: Francis Goudou
Original assignee: Kp1
Priority date: 2006-08-30
Filing date: 2007-08-23
Publication date: 2008-03-06
Also published as: EP2057329A2; PL2057329T3; EP2057329B1; FR2905397A1; WO2008025894A3; FR2905397B1; ES2568041T3

Abstract

A cellular slab comprising an upper plate (2), a lower plate (3) and intermediate partitions (4) between both plates defining between them parallel and longitudinal cells (5), characterised in that it comprises at least one lifting ring (9) made of a metallic wire in the shape of a staple protruding from a concrete block (10) provided under an opening (7) formed in the lower plate (2) vertical to an intermediate partition (4), the branches of the staple (9) being folded so that their free ends (16, 17) extend under a reinforcement wire (6) of the plate provided in the base (4a) of said intermediate partition.

Description

Capped slab provided with at least one lifting ring.

The present invention relates to a hollow slab pre equipped with a means to facilitate its handling.

BACKGROUND OF THE INVENTION

A dimpled slab comprises an upper plate, a lower plate, and intermediate partitions between the two, defining between them longitudinal cells. These slabs are intended to be juxtaposed and jointed to form floors. At their longitudinal ends, a prestressing framework opens to ensure their connection with the walls of a building.

One of the problems encountered when using hollow core slabs lies in their handling difficulty.

One of the methods used to move such slabs is to use self-erecting clamps taking position in the reliefs of the longitudinal edges of the slabs which constitute, once set up, the connecting keys of juxtaposed slabs. However, there have been numerous accidents caused by the misuse of these clamps or the breaking of compressed concrete in their jaws. A safety chain must double these clamps to retain the slab in case of failure. This one is unfortunately not often put in place.

Another method of handling is to pass a strap under the slab at each of its ends. This method, more secure than the previous one, is only really effective if there is an anti-slip system between the slab and each of the straps so as to prevent the slab from escaping from its support. One of the major disadvantages of this method lies in the fact that it is not possible to juxtapose two slabs edge to edge, given the presence of the straps that are interposed between the slabs. A remedy for this defect has been proposed by making notches on the edges of the slabs 5 intended to receive the straps so as to extract them once the slabs placed edge to edge. It is however necessary on the site, proceed to the filling of these notches.

Another method of handling these slabs is to make holes in the slab at the factory and to place a sling in these holes so that the eye of the latter protrudes under the slab and is blocked by a bar. or a disc. This process is long and tedious, so expensive. He asks like the previous one, to re-fill the holes on site, which is a delicate operation and which harms the esthetics of the realized floor.

Finally, document FR 2 822 868 proposes incorporating at the time of manufacture of the slab a transverse cable under the prestressing reinforcement, at least at each of its ends, this cable extending laterally from the slab. The outer end of these cables is provided with an eyelet which is the gripping means of the slab and when placed on site by juxtaposition, the outer portion of the cables and the eyelet can be folded to the inside in the space that forms the connecting joint of two adjacent slabs. The main disadvantage of this arrangement lies in the difficulty of integrating during the manufacture of a slab this transverse element. Indeed, a hollow slab is manufactured by an extrusion process so with a preferred direction and any element constituting this slab in another direction generates a manufacturing complication. Furthermore, the need to precisely accommodate the ends of the support cable in the inter-slab joints requires site operators to act with precision and especially not to forget this operation. However, we know that the conditions of work on site are not conducive to precise and delicate tasks. OBJECT OF THE INVENTION By the present invention, it is intended to provide a more satisfactory solution than that known for the handling of hollow core slabs which does not require any particular operation to be performed on site and which does not lead to significant complications at the time of manufacture of the slab.

SUMMARY OF THE INVENTION

For this purpose, therefore, the invention has for first object a cellular slab comprising an upper plate, a lower plate and intermediate partitions between the two plates defining between them parallel and longitudinal cells remarkable in that it is provided with less a lifting ring, constituted by a wire shaped as a jumper emerging from a concrete block located under an opening in the upper plate, directly above an intermediate partition, the branches of the rider being they themselves folded so that their free end extends under a reinforcing wire of the plate disposed in the foot of said intermediate partition. The lifting ring thus formed acts on the reinforcement of the slab and not on the concrete, which is a guarantee of safety of its anchoring.

The concrete block in which the ends of the rider's limbs are drowned is produced by the top plate collapsing at the location of the opening and a part of the partition located at its right angle. The anchoring of the lifting ring is then achieved without adding new concrete, which simplifies the operation.

The hoisting ring jumper can take many forms in that the end of its branches can be slid under a reinforcing wire of the slab. In one embodiment, the rider has a vertex from which the two branches depart whose free ends are coplanar in an arc and symmetrical to each other with respect to a center which is the projection of the vertex on their plane. The total height of the rider will be such that its top will be located under the upper surface of the slab when the branch ends will be slid under the longitudinal frame wire of the slab. The second object of the invention is the method of producing the above-mentioned slab which consists, once the slab from its manufacturing machine, to proceed with the arrangement of an orifice in the upper plate, straddling an intermediate partition. by collapsing the still fresh concrete of this plate and leveling the top of the partition, introducing the rider astride the concrete block resulting from the making of the orifice so that the free coplanar ends of its branches are located at a level lower than that of the above-mentioned wire, turning the jumper about a quarter of a turn to slide said free ends under the reinforcing wire and vibrating the concrete block drowning the ends of the branches of the rider.

The implementation of this method is simple since apart from the rider, no additional material is required to proceed with the sealing of this rider in the slab. There is therefore a great homogeneity in the material of the slab, even at the level of the lifting ring.

Finally, the invention finally has a tool for implementing the aforesaid method, which comprises a wire cutting tool having a closed contour identical to the contour of the housing to be made, a handling handle of the rider capable of maneuvering from from the top of the latter, and a roller compactor. These tools will be put in place at the end of a vibrating head (hand-held needle in the case of a manual tool or robotic machine trolley with programmed control in the industrial production phase) in an interchangeable way to carry out the process of manufacture above. Other features and advantages of the inven ^¬ apparent from the description given below of some examples of its realization.

BRIEF DESCRIPTION OF THE DRAWINGS

Reference will be made to the appended drawings in which: FIG. 1 is a partial cross-sectional view of a cellular slab,

FIG. 2 illustrates this same cellular slab provided with a hole for accommodating a lifting ring,

FIG. 3 illustrates the above-mentioned hollow slab equipped with the lifting ring according to the invention;

FIG. 4 illustrates a device for protecting the lifting ring,

FIG. 5 is a perspective view of a first embodiment of the hoisting ring according to the invention;

FIGS. 6A, 6B and 6C are respectively front, side and top views of a second embodiment of this hoisting ring,

- Figure 7 illustrates a first tool for preparing the slab for the establishment of the lifting ring,

FIGS. 8A and 8B are two orthogonal views of a second tool for setting up this ring,

- Figure 9 finally illustrates a tool for compacting the sealing area of the lifting ring.

DETAILED DESCRIPTION OF THE INVENTION In the figures, a hollow core slab 1 is shown as having an upper plate 2, a lower plate 3 higher, longitudinal partitions 4 extending between these two plates to define therebetween the cells lon ^¬ gitudinaux 5 . This slab comprises a pre ^¬ constraint frame whose longitudinal son 6 is shown in a root portion 4a of each partition 4. in Figure 2, the panel shown in section pre ^¬ feel an orifice 7 which was created by smashing of the upper plate 2, the broken concrete constituting a scouring 8 around the root portion 4a of the partition 4 at the base of which the orifice has been formed.

FIG. 3 illustrates the disposition of a lifting ring 9 whose open geometry illustrated below allows ends of this ring to be slid under a prestressing reinforcing wire 6 and whose lower part of the branches is embedded. in a solid mass 10 of concrete which is made by compacting the landslide 8. The top S of the lifting ring 9 is at a level which is (Jm / more flush with that of the upper surface of the slab. FIG. 4 shows a plastic reinforcement 11 which has elastic tabs 11a capable of engaging under the edges of the orifice 7 and a bottom 11b traversed by the vertex S of the ring 9, this reinforcement 11 having a cover 12 folds and enclic- table on itself when it is put in place in the orifice 7.

In Figure 5, the lifting ring is shown alone. It can be seen that it has the shape of a jumper 13 having a vertex S and two branches coming from this vertex 14 and 15, here diverging, each of the branches being terminated by a circular end 16, 17, these ends being coplanar, therefore belonging to the same plane P. The center of the radius of curvature of each of these ends 16, 17 is a point C of the plane P which is the projection of the summit S of the rider. A dashed prestressing wire 6 is shown in phantom to illustrate the position in space of this rider 13 when it constitutes the hoisting ring of a hollow slab. It can be seen that this reinforcement 6 is situated above the coplanar ends 16 and 17 and crosses them substantially in their middle.

In FIGS. 6A, 6B and 6C there is shown an alternative embodiment of the jumper of FIG. 5. In this variant, the branches 14 and 15 are each divided into three parts, a first part 14a, 15a which forms with the top S of the jumper a U, a second part 14b, 15b which extends the first part of each branch diverging from the plane containing them, a third lower part 14c, 15c each parallel to the plane containing the first parts 14a, 15a, the free ends 16, 17 being formed in an arc at the end of the portions 14c and 15c. These ends 16 and 17 pass through the plane containing the first portions 14a and 15a of the arms 14 and 15 of the rider. FIGS. 6A and 6B show that, when projected in a plane passing through the middle of the ends 16 and 17 and the top of the rider, the latter affects the shape of a closed loop (FIG. 6B) whereas, when projected in a plane perpendicular to that of FIG. 6B, the jumper has the shape of an open U (FIG. 6A).

The tool shown in FIG. 7 is a manual tool used to make the orifice 7. It comprises a vibrating needle 20 known in itself and a wire 22 defining a closed contour identical to the contour of the orifice 7, located in a plane perpendicular to the axis of the vibrating needle 20 and coupled thereto by flanges 21.

The operator, at the outlet of the extrusion machine of the cellular slab, applies on the plate 2 the tool of FIG. 7, the vibrations of which allow cutting of the orifice 7. The concrete located inside the slab closed wire 22 sinks on each side of the root 4a of the partition 4 whose top is also leveled. The result is shown in Figure 2.

The operator equips the vibrating needle 20 with a second tool shown in FIGS. 8A and 8B which consists of a gripper 23 equipped with a handle 24 which makes it possible to take charge of the upper part 14a, 13a of the jumper shown in FIGS. Figures 6A, 6B and 6C. This jumper is introduced vertically inside the orifice 7, and while the vibrating needle is in use, is pressed into the landslide 8 to a level slightly below this. he level of the prestressing wires 6. The depression of the jumper 13 is oriented, that is to say that it is made in the position thereof shown in Figure 8B, so that in the end of this depression, the pre-stressing wire 6 is located between the arms 14 and 15 of the rider.

Having reached this level, the operator rotates about one-quarter turn of the jumper, so that the ends 16 and 17 of the latter come to slip under the reinforcing wire 6 and cross it.

Finally, by means of a last tool 25 coupled to the vibrating needle 20, the compacting 8 is carried out in which the lower part of the rider 9 is embedded, compacting which leads to a homogeneous concrete mass 10 and consistent with the rest of the concrete slab, ensuring the strength and safety of the anchor of the rider in the thickness of the slab.

All these operations were carried out while the concrete was still fresh at the exit of the slab extruder type machine on the tensioned tendons. We finish its preparation by placing the shutter formed by the armature 11 equipped inside the pin 7 and the cover 12 which is articulated and which is snapped on this frame. The means of handling waiting on the slab have been set up without having overly complicated the conventional method of manufacture of this slab and they will not oppose any of the operations of setting up on site some slabs next to others. Note that the manufacture of a cellular slab according to the invention in an industrialized process, will use a robotic machine comprising a vibrating head to which the aforesaid equipment (cutting wire, hook grip grip and compactor) can be hitched interchangeably or comprising several heads mounted in a carousel on a movable carriage programmed on a gantry spanning the slab at the exit of the extruder manufacturing.

Claims

1. Cellular slab comprising an upper plate (2), a lower plate (3) and intermediate partitions (4) between the two plates, defining between them parallel and longitudinal cells (5), comprising at least one ring ( 9), constituted by a wire configured as a jumper, the legs of the jumper (9) being folded so that their free end (16, 17) extends under a wire (6) of plate reinforcement disposed in the foot (4a) of said intermediate partition, characterized in that the rider emerges from a concrete block (10) located under an opening (7) in the upper plate (2), to the plumb with a partition (4) intermediate and in that the solid mass (10) of concrete is made by collapse or collapse of the upper plate at the location of the opening (7) and a part of the partition (4) located at its right.

2. Slab according to claim 1, characterized in that the rider has an apex S from which the two legs (14, 15) on the free ends (16, 17) are coplanar in a circular arc, symmetrical one of the other in relation to a center (C) which is the projection of the vertex (S) on their plane (P).

3. Slab according to claim 2, characterized in that, in projection, in a vertical plane passing through the top and the middle of the two branch ends, the rider affects the shape of a U, while in projection in a vertical plane perpendicular to the first, the cavalier has the form of a closed loop.

4. Slab according to one of the preceding claims, characterized in that the top (S) of the rider is located under the upper surface of the plate (2) of the slab and is covered with a protective device (11, 12 ).

5. A method of producing the slab according to one of claims 2 to 4, characterized in that it consists, once the slab from its manufacturing machine, to proceed to the development of an orifice (7). ) in the upper plate (2), straddling an intermediate partition (4) by collapse of the still fresh concrete of this plate (2) and leveling the top of the partition (4), to introduce the rider (9) on horseback on the concrete scree resulting from the making of the orifice (7) so that the free coplanar ends (16, 17) of its branches (13, 14) are located at a level lower than that of the wire (6) of aforesaid reinforcement, rotating about a quarter of a turn the rider (9) to slide said free ends (16, 17) under the reinforcing wire and to vibrate the scree (8) of concrete to make a solid (10) drowning the ends of the rider's limbs.

6. Tooling for implementing the method according to claim 5, characterized in that it comprises a cutting wire (22) closed, a handle (24) for maneuvering the cavalier and a compactor (25) with pads ( 26), the wire, the handle and the compactor being interchangeably attachable to the vibrating head (20) of a robotic machine.