EP0688613B1 - Reinforcement for supported concrete floor in the neighbourhood of the supports and method for making it - Google Patents

Abstract

The reinforcement for concrete ceilings in the regions of the supports consists of longitudinal and connector elements. It is characterised by the fact that the longitudinal elements (61) are bent into a shape corresponding to the curve of periodic and/or aperiodic modes of oscillation. Such a reinforcement is produced by bending a grid consisting of longitudinal and connector rods (61,62) about a bending axis oriented parallel to one of the connector rods (62). The bending machine incorporates at least three bending units which in a coordinated manner bend the grid into at least one wave. Pref. the longitudinal (61) and connector (62) elements respectively within their own arrays are oriented parallel to one another. The reinforcement shape approximates rectangular or arcuate waveforms (or their combinations) with constant amplitudes. The bending machine is provided with a unit for coordination of the motion of its bending units which are made up of bending bars and corresponding opposing elements. <IMAGE>

Description

The present invention relates to reinforcement for supported Concrete ceilings to absorb shear forces in the area of their supports, which reinforcement longitudinal and has connecting elements according to the preamble of claim 1, and a method for Manufacture of such reinforcement for concrete slabs, according to the generic term of claim 10.

When introducing loads from concrete slabs on their supports Large shear stresses arise in the concrete ceiling. This can cause the column to be punched through the concrete floor to lead.

To prevent this punching or to take up the A corresponding shear reinforcement must be inserted in shear forces become. The easiest way to do this is to insert vertical ones Bars run in the concrete ceiling, this vertical bars both above, in the concrete tensile zone, as well below, in the concrete pressure zone, be well anchored in the concrete have to.

The so-called crack dowel strips belong to the state of the art, the crack U strips and the crack stars, which in the Best in the professional world and through publications in magazines have become known. Another version is known under the name Anco-Tech. The also has a certain meaning Execution achieved after Aschwanden. This will be U-shaped Rods, the free ends of which are bent at the end in a hairpin shape are placed one after the other and next to each other in rows and with corresponding straight connecting rods connected.

With such reinforcements, in addition to the dimensioning vertical bars, the actual shear reinforcement, the safe Anchoring in the concrete pressure zone or in the concrete tensile zone of of greatest importance. This anchoring happens with the Crack dowel strips on one side by welding onto iron plates on the one hand and on the other hand by surfacing the Push bar. The anchorages of crack-U-as well are similar of Anco-Tech reinforcements.

The push rod is anchored when reinforcing ash walls below in itself, while the anchoring above by standards End hook is effected. This solution, although anchoring technology okay, is extremely expensive and by making the many individual brackets and assembling them extremely labor intensive.

The Rissstern may be sufficient for smaller thrust forces but especially unsatisfactory in terms of anchorage.

Neither an ordinary Mat bending machine still used a folding machine because at a normal distance between the shear reinforcement bars of approx. 10cm the already finished part subsequent bending processes for space reasons. Furthermore the parallel longitudinal bars must be bent very precisely, because otherwise the corresponding angular errors add up and the finished reinforcement could not stand "straight".

DE-A-2 205 852 describes a method for producing a Reinforcement for concrete ceilings, concrete walls and the like. the reinforcement is defined as a lattice girder and serves as Connection between a prefabricated concrete slab and a on-site concrete slab or Concrete walls. These elements cannot take over thrust.

The present invention has as its object such Manufacture reinforcement, both in terms of their Production as well as material compared to the state of the Technically cheaper, extremely practical anchorage technology prefabricated reinforcements for thrust bodies aimed for become.

The stated object is achieved by means of a reinforcement according to claim 1 or by means of a method according to claim 10.

Claim 11 relates to a supported concrete ceiling with a reinforcement according to the invention.

The invention is then based on, for example Drawing explained

Fig. 1

einen Längsschnitt durch eine Biegemaschine zum Herstellen von Durchstanzbewehrungen aus Netzen, mit eingelegtem Netz und angedeuteten, bereits gebogenen zwei Wellen, in Ausgangslage,

Fig. 2

einen Schnitt gemäss Schnittlinie II - II der Fig. 1,

Fig. 3

einen Schnitt gemäss Schnittlinie III - III der Fig. 1,

Fig. 4 bis 10

den Biegevorgang, dargestellt in einzelnen Teilvorgängen, in schematischer Darstellung,

Fig. 11

einen Längsschnitt durch eine weitere Ausführungsform einer Biegemaschine, analog Fig. 1,

Fig. 12

einen Schnitt gemäss Schnittlinie XII - XII der Fig. 11,

Fig. 13

ein aus Längs- und Verbindungsstäben bestehendes Spezialnetz, in zu einer Bewehrung gebogenem Zustand, in Aufsicht,

Fig. 14

die Bewehrung gemäss Fig. 13 in Vorderansicht,

Fig. 15

das gebogene Netz gemäss Fig. 14 in perspektivischer Darstellung, im Ausschnitt,

Fig. 16 bis 20

aus einem Spezialnetz durch Biegung hergestellte Bewehrungen in Vorderansicht mit unterschiedlichen Biegeformen und unterschiedlicher Lage der die gebogenen Längsstäbe verbindenden Quer- oder Verbindungsstäbe.

Show it:

Fig. 1

2 shows a longitudinal section through a bending machine for producing punching shear reinforcements from nets, with an inserted net and indicated, already bent two shafts, in the starting position,

Fig. 2

2 shows a section along section line II-II of FIG. 1,

Fig. 3

2 shows a section along section line III-III of FIG. 1,

4 to 10

the bending process, shown in individual sub-processes, in a schematic representation,

Fig. 11

2 shows a longitudinal section through a further embodiment of a bending machine, analogous to FIG. 1,

Fig. 12

7 shows a section along section line XII-XII of FIG. 11,

Fig. 13

a special net consisting of longitudinal and connecting rods, in a bent condition to form a reinforcement, under supervision,

Fig. 14

13 the reinforcement according to FIG. 13 in front view,

Fig. 15

14 in a perspective view, in the detail,

16 to 20

Reinforcements made from a special mesh by bending in front view with different bending shapes and different positions of the transverse or connecting rods connecting the bent longitudinal bars.

The bending machine 1 shown in Fig. 1 is located in the rest / starting position. A special net 2 is in the machine introduced, with two bending processes corresponding two waves 37 of the network 2, on the right in FIG. 1, are indicated.

The bending machine 1 has three bending units 3, 4 and 5. Each of these three units has a bending beam 7 or 8 and 9 and an associated counter-holder 11, 12, 13.

The working movement of the bending beams is shown in the Example using two piston presses 21 and 22 for the bending beam 8, through the piston presses 18 and 19 for the bending beam 9 and by the piston presses 15 and 16 for the counter holder 12th

All of these parts are arranged in a machine frame 24. Vertical guides 26 are also in this machine frame 24 arranged for guiding the bending beam 8 as well Horizontal guides 28 for guiding the counterhold 11 and 13, which each actuated by means of a piston press 30 or 31 become.

The curved parts of the special network 2 form, as in FIG. 1 indicated bending waves 37, their zenith with 33 and their nadir is designated 35. There are also connecting rods 34 indicated.

With larger machines, instead of the three shown Bending units whose five, seven or even more units are provided, all of which at least at the same time make three or five, seven, etc. bends simultaneously.

The bending beams 7, 8 and 9 must be in the arrangement shown be strong, i.e. have a large moment of resistance of their own. Because they must be the large ones that occur during the bending process Absorb forces without this relatively large span to bend itself noticeably.

The counterholders 11, 12 and 13 can be dimensioned somewhat lighter become. First, the counter-holder 12 is pressed using the piston press 15 and 16 pressed against the bending beam 8. Then the bending beam 8 by means of the piston presses 21 and 22 pressed upwards in the vertical guides 26, while maintaining the counter pressure.

1 schematically in FIG. 4 5 shows the position in which the bending units with their bending beams 7, 8 and 9 with clamping of the network 2 with the counterholders 11, 12 and 13 in the bending / starting position are. The bending beams 7 and 9 and the counter bracket 12 are by means of their piston presses in the 5, for example the bending beam 9 by means of the piston presses 18 and 19. So that is to be bent Special net 2 fixed during the bending process and therefore get an accurate bending shape.

After introducing the special network 2 and pressing the Counter brackets and bending beams are activated by synchronous actuation of the two piston presses 21 and 22 and while leaving the counterpressure of the piston presses 15 and 16 of the bending beams 8 guided in the vertical guides 26, with the associated one Counterholder 12 pushed up, while the two bending units 3 and 5 with their bending beams 7 and 9 and the associated counterholders 11 and 13 by means of Piston presses 30 and 31 in the horizontal guides 28 also be moved against each other. In this way, one Loop or flexible shaft 37 pressed. Advantage of this Solution is also that both the undeformed and that already deformed power supply always remain at the same height and thus the gradual forward movement of the network 2 is easy to do.

Instead of the piston presses shown, e.g. as a drive electronically controlled stepper motors can also be used. This is likely to replace presses 21, 22 and 30 and 31 can be advantageous because, depending on the height of the drawer, have to travel different ways to get from the location 5 in the position shown in FIG. 6. This Bending process (Fig. 4 to 6) will thus be as follows play:

The special network 2 is introduced according to FIG. 4. Then be 5 the counter-holder 12 and the bending beams 7 and 9 brought into their contact position. This will make the network 2 fixed.

In the sense of FIG. 6, the middle bending unit is then 8, 12 pressed up while holding the two outer bending units 7, 11 and 9, 13 against each other to be pressed towards the middle. Because of the springback of the curved Bars 32 are illustrated in FIG. 6, somewhat above to move the perpendicular towards each other, so that after loosening the aggregates the desired angles, usually 90 °, are strictly adhered to. It is possible that To measure bending angles electronically, and if necessary, by Correction in the sense of FIG. 6 to correct.

After completion of the bending process according to FIG. 6, according to Fig. 7, the bending units 7, 11 and 8, 12 released and in their Starting position reduced. The bending aggreat 9, 13 remains against it in its position analogous to FIG. 6.

With the help of this bending unit 9, 13, the network 2 for the next bending process brought into the position shown in Fig. 8 become.

In the next step, according to FIG. 9, the bending unit 3 clamped together again with bending beam 7 and counter-holder 11, to fix the net 2 while the bending unit 5 9, 13 is solved.

As the final act of an operation, the unit 5 in brought his starting position. Another bending process can accordingly, as shown in FIG. 4.

Instead of as shown in Fig. 8, the feed of the network 2 can be accomplished by its own feed device. In this case, after completing the bending process 6, all bending units released and directly in the starting position in the sense of FIG. 4, whereupon the Network 2 is advanced and another bend is made can.

Centering bolts can be attached to the bending beams or the counter supports (Not shown) are attached, which the network 2 with Position precisely using the cross bars or connecting bars 34. The bending beams are provided with standard-compliant bending radii, to protect the mesh from notching effects in the bending areas preserve.

As a variant to the two-part bending units, the Execution according to FIGS. 11 and 12 also simple bending beams 50, 51 and 52 can be used. These bending beams will be then provided with bending fingers 54. But that has to be the case Net 2 before each bending process with an additional device lowered and inserted laterally into the bending fingers 54 (arrow direction 56). After the bending process, this has to be done Correspondingly, net 2 again laterally from the bending fingers 54 pushed out and raised so that it can be advanced can, as indicated in FIGS. 11 and 12.

It is obvious that the bending beams and counter supports have shapes corresponding to the desired waveform have to.

13 shows the basic structure of a special network, which depending on the desired design, such as 14 to 20 show on an ordinary one Mesh welding machine can be manufactured. The network points Longitudinal or push rods 61, which in the present case are arranged parallel to each other while the transverse or Connecting rods 62 according to the desired shape the same or different distances from each other are. This net is used in a bent state to Shear forces in supported concrete ceilings in the area of the supports record what is due to the appropriate stability of the mat or the finished, so-called drawer is made possible.

The vertical ones are anchored in these forms Parts 63 of the push rods 61 both in the pressure zone and in the tensile zone of the concrete ceiling continuously in itself.

The advantages of this new embodiment according to the invention are briefly summarized below.

These reinforcements form a continuous secure anchor in itself.

The material savings are at least the same Known reinforcement quality approximately 10 to 20%. The production this reinforcement is simple and cheap.

As a general feature, it should be noted that the distance between the vertical parts 63, as can be seen in the figures, about 10 to 15 cm, while the height of approx. 15 depending on the ceiling thickness up to 50cm can vary in steps from 1 to 2cm. By appropriate Training of the explained bending machine can such reinforcements according to the invention are extremely safe and be produced economically. It is possible to do different Shapes as shown in Figs. 14 to 20 are to combine with each other what by making 13 as well as the corresponding parts the bending machine can be reached. If the curved Longitudinal bars 61 only on their horizontal parts or only on the lower horizontal parts have connecting rods 62, or if the arrangement is made so that every second vertical part 63 longitudinal rods 61 free of connecting rods 62 is a simple, inexpensive stacking of the finished Baskets may be possible. Unstacking is then caught individual baskets, as is the case with the state of the art Technology is possible not to fear. Of course the bends have standard radii. Usually the connecting rods 62 have a smaller diameter than that bending longitudinal bars 61.

Claims (11)

1. Reinforcement for absorbing thrust forces in supported concrete floors in the area above the supports, the said reinforcement having longitudinal and connecting elements, only longitudinal elements (61) being bent into periodic and/or aperiodic wave shapes, characterized in that each wave shape has at least one portion (63) which, between the base and the vertex, is vertical in relation to the plane of the reinforcement.
2. Reinforcement according to Claim 1, characterized in that the longitudinal elements (61) and/or the connecting elements (62) are arranged to be parallel to one another.
3. Reinforcement according to either of Claims 1 and 2, characterized in that the base and/or the vertex of the wave shape are designed to be at least approximately curved and/or rectilinear, in particular circular and/or rectangular.
4. Reinforcement according to one of Claims 1 to 3, characterized in that the amplitudes of the waves are equal.
5. Reinforcement according to one of Claims 1 to 4, characterized in that the amplitudes of the waves or their mutual spacings are unequal.
6. Use of a reinforcement according to one of Claims 1 to 5, characterized in that the wave shape is trapezoidal.
7. Reinforcement according one of Claims 1 to 6, characterized in that the longitudinal element is equlpped, over one wave, with at least one connecting element, in particular with up to four connecting elements.
8. Reinforcement according to one of Claims 1 to 7, characterized in that the connecting elements are arranged only in the area of the zenith and/or of the nadir.
9. Reinforcement according to one Claims 1 to 8, characterized in that, in the case of longitudinal elements (61), only each second vertical part (63) has no connecting element (62).
10. Process for producing a reinforcement according to one of Claims 1 to 9 for use in supported concrete floors in the area of their supports to absorb thrust forces, a network comprising longitudinal and connecting rods (61, 62) being bent about a bending axis parallel to one of the connecting rods (62) to form a structure in which the longitudinal rods (61) form periodic or aperiodic wave shapes, characterized in that, between the base and the vertex of each wave form, at least one vertical portion is bent up in relation to the plane of the reinforcement.
11. Supported concrete floor having reinforcement according to one of Claims 1 to 9 in the area above the supports.

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