DE29808491U1 - Reinforcement element for shear reinforcement - Google Patents

Description

Registration for use

Reinforcement element for shear reinforcement

DAUSEND, Hans-Werner
Heinrich-Janssen-Strasse 24 D-42289 Wuppertal (DE)

826 VGN: 258024 Mu./Pa./G May 5, 1998

Reinforcing element for shear reinforcement

The invention relates to a reinforcement element for shear reinforcement in beams and slabs made of reinforced concrete with an upper and a lower horizontal section and a vertical section connecting the horizontal sections.

In order to fully exploit the bending load-bearing capacity of a reinforced concrete slab supported at points, taking into account the risk of punching shear, various solutions in the form of additional reinforcement elements are known. Reinforcement elements for shear reinforcement in the form of dowel strips are known, which are arranged radially around the respective support. Such dowel strips connect the lower reinforcement layer of the slab with the upper one to transfer the shear forces. Reinforcement elements for shear reinforcement are also known, which consist of an upper and a lower horizontal section and a vertical section connecting the horizontal sections, whereby the connecting section is usually designed as an inclined bar. Such reinforcement elements are connected with their lower horizontal section to the lower reinforcement layer of the slab. The same happens with the upper horizontal section and the upper reinforcement layer of the slab.

In view of the state of the art described above, a technical problem of the invention is seen in the design of a reinforcement element for shear reinforcements of the type in question that is easier to handle, in particular with regard to handling on site.

22 826 VGN: 258024 Mü./Pa./G 05.05.1998

This problem is initially and essentially solved by the subject matter of claim 1. For example, the free-standing design of the reinforcement element due to cross-connected, adjacent upper and lower, as well as vertical sections of two individual elements, makes handling on site considerably easier. The reinforcement element according to the invention does not have to be laboriously aligned, particularly in the vertical direction. The reinforcement element is very simply put down and simply positioned in its horizontal alignment to the support. The reinforcement elements according to the invention can then be attached to the lower reinforcement layer of the slab, for example using wire loops or the like. In addition, the distance between the two reinforcement layers of the beam or slab is predetermined by the free-standing reinforcement elements, whereby the upper horizontal sections of the individual elements can also serve as support elements for this upper reinforcement layer. In addition, the design of the reinforcement elements according to the invention means that several - for example, three - reinforcement layers can be used to increase the shear resistance. Two reinforcement elements assembled in this way can be placed together, which at least doubles the relevant reinforcement cross-section. It is also intended that the vertical section is designed to run diagonally. It is preferred that the vertical section runs at 45° to the horizontal. For manufacturing reasons, however, the vertical section can also run at an angle of more or less than 45°, for example in a range between 30 and 60°. In order to achieve good force transmission, it is intended that the horizontal sections have cantilevered insertion sections. By means of these sections, the

22 826 VGN: 258024 Mü./Pa./G 05.05.1998

Horizontal sections of the individual elements of the reinforcement element are inserted into the lower or upper reinforcement layer or positioned within the reinforcement layer of the lower reinforcement, whereby this plug connection can also be additionally fixed by wire loops or the like. It is also provided that an insertion section has at least a length corresponding to the distance between the lower and upper horizontal sections. In an advantageous development of the subject matter of the invention, it is provided that two vertical sections are provided on an individual element, both of which connect to the opposite ends of the upper horizontal section. For this purpose, it is further proposed that two lower horizontal sections are formed on an individual element, each of which connects to a vertical section. The two lower horizontal sections can also be omitted for assembly reasons and instead the vertical bar can be extended downwards by approx. 3 cm. It is also possible for the length of a vertical section to exceed the distance between the lower and upper horizontal sections. The section of the vertical section that extends downwards over the first lower horizontal section is pushed through the lower reinforcement layer during assembly and rests, for example, on the already concreted top of the column. The inventive design of a reinforcement element made up of two individual elements running next to each other, which have the vertical and horizontal sections described above, results in a box-like element that can be positioned on site in a very simple manner. In one embodiment of the subject matter of the invention, the two separate lower horizontal sections of an individual

22 826 VGN: 258024 Mü./Pa./G 05.05. 1998

element in the same direction. This results in an approximate eyelet shape, with the eyelet section being formed by the two vertical sections, the upper horizontal section and the second lower horizontal section. In an alternative embodiment, it can be provided that the two separate lower horizontal sections run in opposite directions. This essentially results in a stirrup shape of the reinforcement element. In a further embodiment, it is provided that both vertical sections run at an angle. It is preferred that both vertical sections run at 45°, although here too, deviations due to manufacturing are possible, so that angles of 30 to 60° are established. It is also preferred that an individual element consists of a bendable ribbed structural steel. This is a common material for reinforcing concrete parts. In order to create an inherently stable, cage-like reinforcement element, it is also provided that the cross connection is formed by welded rods running perpendicular to the individual elements, with ribbed structural steel being used preferably here too.

The invention also relates to a ceiling supported by a free-standing column, the ceiling having two vertically spaced reinforcement mats and a punching shear reinforcement being formed in the overlap to the column. In order to fully exploit the bending load-bearing capacity of a point-supported reinforced concrete slab, taking into account the risk of punching shear, it is proposed that the punching shear reinforcement consists of a reinforcement element according to one or more of claims 1 to 12.

22 826 VQST: 258024 Mü./Pa./G 05.05.1998

The invention is explained in more detail below with reference to the accompanying drawing, which merely shows several embodiments. It shows:

Fig. 1 is a schematic sectional view of a reinforced concrete slab resting on a support at points with reinforcement elements according to the invention for the shear reinforcement in a first embodiment;

Fig. 2 the shear reinforcement element of the first embodiment in a side view;

Fig. 3 shows the reinforcement element of the first embodiment consisting of two individual elements running next to each other in a perspective view;

Fig. 4 shows the reinforcement element according to Fig. 3 in a perspective view, but with three individual elements arranged side by side;

Fig. 5 is a schematic sectional view corresponding to Fig. 1 with a reinforcement element in a third embodiment;

Fig. 6 is a perspective view of the reinforcement element from Fig. 5;

Fig. 7 is a perspective view of another alternative embodiment of the reinforcement element;

826 VGN: 258024 Mu./Pa./G May 5, 1998

Fig. 8 is a further perspective view of a reinforcement element in a fifth embodiment;

Fig. 9 shows a sixth embodiment of the reinforcement element, also in perspective view;

Fig. 10 is a schematic sectional view corresponding to Fig. 1 with a reinforcement element in a seventh embodiment;

Fig. 11 the reinforcement element from Fig. 10 in a side view;

Fig. 12 is a further sectional view corresponding to Fig. 1, concerning an alternative arrangement of the reinforcement elements according to Fig. 11.

Shown and described with reference to Fig. 1 is a slab 2 made of reinforced concrete which forms a ceiling 1 and is supported at points by a free-standing column 3. This ceiling 1 has two reinforcement mats 4, 5 which are spaced vertically from one another.

In order to fully exploit the bending load-bearing capacity of such a point-supported reinforced concrete slab, taking into account the risk of punching shear, shear reinforcement elements 7 are provided in the support area 6 of the slab 2, which are laid out with the reinforcement mats 4 and 5 during the slab formwork.

The drawings show various embodiments of shear reinforcement elements 7. What is uniform in these is that each reinforcement element 7

22 826 VGN: 258024 Mü./Pa./G 05.05. 1998

is composed of at least two individual elements 8 running next to one another, which individual elements are cross-connected by welded rods 9 running perpendicular to them. The individual elements 8 are formed from a bendable ribbed structural steel.

This design according to the invention means that each reinforcement element 7 is designed to be self-supporting, which offers advantages in particular for the concrete worker on site. He only needs to insert the reinforcement elements 7 into the lower reinforcement mat 4 supported by spacers 10 or to position them on this reinforcement mat, after which the reinforcement element 7 remains self-supporting in the desired position. It is only necessary to correctly align the reinforcement element 7 with the support area 6.

In Fig. 1 to 3, a first embodiment of a reinforcement element 7 is shown, which is composed of two adjacent, cross-connected individual elements 8. Each individual element 8 has an upper horizontal section 11 and a lower horizontal section 12, whereby these horizontal sections 11 and 12 are connected to one another by a vertical section 13 running at an angle of approximately 45°. The length of the lower horizontal section 12 in the embodiment shown is approximately 60% of the total length of the reinforcement element 7.

The distance between the two horizontal elements 11 and 12 is adapted to the distance between the reinforcement mats 4 and 5, so that the upper horizontal section 11 simultaneously forms a support for the upper reinforcement mat 5.

22 826 VGN: 258024 Wed./Pa./G 05.05.1998

The lower horizontal section 12 forms a cantilevered insertion section 14 with which each individual element 8 of the reinforcement element 7 is inserted into the lower reinforcement mat 4, wherein this insertion section 14 has at least a length corresponding to the distance a between the lower and upper horizontal sections 11, 12.

The reinforcement element of the first embodiment shown in Figures 1 to 3 further has a second vertical section 15, which adjoins the end of the upper horizontal section 11 facing away from the first vertical section 13. This vertical section 15 extends downwards at a right angle to the upper horizontal section 11 with a length which corresponds to the distance between the upper and lower horizontal sections 11, 12 (distance a).

The free end of this second vertical section 15 is followed by a second lower horizontal section 16 which extends perpendicular to the vertical section 15, parallel to the upper horizontal section 11 in the direction of the first lower horizontal section 12. The length of this second lower horizontal section 16 corresponds approximately to half the length of the upper horizontal section 11.

The connection of the two identically designed individual elements 8 is made by welded connections via crossbars 9, which run perpendicular to the individual elements 8. In the first embodiment shown, two of the bars 9 are provided, each assigned to the transition areas between the first, obliquely running vertical section 13 and the adjoining horizontal sections 11 and 12.

22 826 VGN: 258024 Mü./Pa./G 05.05.1998

As can be seen from Fig. 1, the reinforcement elements 7 according to the invention of the first embodiment are positioned with their second vertical sections 15 facing the vertical axis x of the column 3.

In a further embodiment, not shown, the upper horizontal section 11 can be so short in length that the second vertical section 15 adjoins almost directly to the first, obliquely running vertical section 13.

Fig. 4 shows an alternative design to the first embodiment. Here, three individual elements 8 arranged next to one another are provided to form a free-standing reinforcement element 7. The crossbars 9 connecting the three individual elements 8 are extended accordingly.

The distance between the individual elements 8 is - as in the first embodiment - approximately the height distance a between the upper and lower horizontal sections 11, 12.

The design according to the invention provides a reinforcement element 7 which extends in a self-supporting manner up to the upper reinforcement layer 5. The irons (vertical sections 13) which change from the lower to the upper reinforcement layer simultaneously absorb the shear forces. As spacing elements, these also specify the distance between the two reinforcement mats 4 and 5.

In order to be able to absorb larger shear forces, it is also conceivable to place two or more reinforcement elements 7 into one another, for example by combining a two-

22,826 VGN; 258024 MÜ./Pa./G 05.05. 1998

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element according to Fig. 3 with a three-element according to Fig. 4.

Fig. 5 shows a schematic sectional view according to Fig. 1, with a reinforcement element 7 in a third embodiment. This element is shown in Fig. 6 in a perspective individual view.

This is also a reinforcement element 7 consisting of two individual elements 8 running next to each other and connected by crossbars 9. Here, however, the upper horizontal section 11 is elongated - approximately twice the length of the lower horizontal section 12.

Here too, the lower horizontal section 12 merges into an obliquely running vertical section 13, to which the upper horizontal section 11 is connected at the end. This in turn merges into a second vertical section 18, which also runs obliquely at an angle of approximately 45° to the vertical. The orientation of this vertical section

18 is opposite to that of the first vertical section 13. At the lower free end of this oblique second vertical section 18 there is a second lower horizontal section which is aligned opposite to the first lower horizontal section 12.

19 on.

Also in this embodiment, the crossbars 9 are positioned in the area of the transitions from the vertical sections to the horizontal sections.

22 826 VC3J: 258024 Mü./Pa./G 05.05.1998

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As can be seen from the sectional view in Fig. 5, the reinforcement element 7 thus formed extends over the entire support area 6 and beyond, whereby here too - as in the previously described embodiments - the obliquely running vertical sections are arranged outside the projection area of the column 3.

In Fig. 7, a reinforcement element 7 is shown in a fourth embodiment, which corresponds to a halved element according to the embodiment in Fig. 6. This forms insertion sections 14 in both the upper horizontal section 11 and the lower horizontal section 12 for insertion into the respective reinforcement mat 4 or 5.

Two further embodiments of the reinforcement element 7 are shown in Fig. 8 and 9. Each individual element 8 of these reinforcement elements 7 is made up of an elongated lower horizontal section 12 which, when installed, extends over the support area 6 on both sides, with vertical sections 20, 21 adjoining on both sides and pointing upwards perpendicular to this. The length of these vertical sections 20, 21 corresponds approximately to the distance between the reinforcement mats 4 and 5. The upper ends of the vertical sections 21 are followed by upper horizontal sections 22, 23 which extend backwards from the vertical sections 20, 21. The length of these horizontal sections 22, 23 corresponds approximately to half the length of the vertical sections 22, 21. The end regions of the reinforcement element 7 thus formed are accordingly bent approximately in a U-shape.

22 826 VGM: 258024 Mü./Pa./G 05.05.1998

In Fig. 8, two individual elements 8 are combined to form a reinforcement element 7 by means of cross bars 9.

Fig. 9 shows two alternative reinforcement elements 7, each of which is composed of three individual elements 8, which are designed as described above, but here a length to height ratio of approximately 3:1 is selected compared to a similar ratio in the embodiment shown in Fig. 8 with two individual elements 8 of 4:1.

The alternative reinforcement element 7 shown in Figs. 10 and 11 corresponds essentially to the embodiment shown in Figs. 1 to 3. However, here the second lower horizontal section is omitted, for example for assembly reasons. The vertical section 15 running perpendicular to the first lower horizontal section 12 has a length 1 which exceeds the distance a between the lower and upper horizontal sections. In the embodiment shown, the end section of the vertical section projects downwards by approx. 3 cm over the horizontal section 12. The vertical insertion section 25 thus formed is inserted through the lower reinforcement mat 4 during assembly and rests on the ceiling formwork, for example.

In addition, it is also possible - as shown in Fig. 12 - to position the reinforcement elements 7 with their end areas facing the vertical axis x of the column 3 so as to overlap one another. In the embodiment shown, the vertical sections 15 - in relation to the respectively assigned horizontal section 12 - run beyond the vertical

22 826 VOST: 258024 Mü./Pa./G 05.05.1998

kalachse &khgr;. This creates a connection of reinforcement elements 7 in the support area 6.

All disclosed features are essential to the invention. The disclosure content of the associated/attached priority documents (copy of the prior application) is hereby fully included in the disclosure of the application, also for the purpose of incorporating features of these documents into the claims of the present application.

22 826 VG3ST: 258024 MÜ./Pa./G 05.05.1998

Claims (15)

1. Reinforcement element ( 7 ) for shear reinforcement in beams and slabs ( 2 ) made of reinforced concrete with an upper ( 11 ) and a lower horizontal section ( 12 ) and a vertical section ( 13 ) connecting the horizontal sections ( 11 , 12 ), characterized by a self-standing design of the reinforcement element ( 7 ) due to transversely connected, adjacent upper ( 11 ) and lower ( 12 ) as well as vertical sections ( 13 ) of two individual elements ( 8 ). 2. Reinforcing element according to claim 1 or in particular according thereto, characterized in that the vertical section ( 13 ) is designed to run obliquely. 3. Reinforcement element according to one or more of the preceding claims or in particular according thereto, characterized in that the vertical section ( 13 ) extends at 45° to the horizontal. 4. Reinforcement element according to one or more of the preceding claims or in particular according thereto, characterized in that the horizontal sections ( 11 , 12 ) have freely projecting insertion sections ( 14 ). 5. Reinforcement element according to one or more of the preceding claims or in particular according thereto, characterized in that an insertion section ( 14 ) has at least a length corresponding to the distance (a) between the lower ( 11 ) and upper horizontal sections ( 12 ). 6. Reinforcing element according to one or more of the preceding claims or in particular according thereto, characterized in that two vertical sections ( 13 , 15 ) are provided on an individual element ( 8 ), both of which adjoin the opposite ends of the upper horizontal section ( 11 ). 7. Reinforcing element according to one or more of the preceding claims or in particular according thereto, characterized in that the length ( 1 ) of a vertical section ( 15 ) exceeds the dimension of the distance (a) between the lower ( 11 ) and upper horizontal sections ( 12 ). 8. Reinforcement element according to one or more of the preceding claims or in particular according thereto, characterized in that two lower horizontal sections ( 11 , 16 ) are formed on an individual element ( 8 ), each of which adjoins a vertical section ( 13 , 15 ). 9. Reinforcing element according to one or more of the preceding claims or in particular according thereto, characterized in that the two separate lower horizontal sections ( 11 , 16 ) run in the same direction. 10. Reinforcing element according to one or more of the preceding claims or in particular according thereto, characterized in that the two separate lower horizontal sections ( 11 , 19 ) run in opposite directions. 11. Reinforcement element according to one or more of the preceding claims or in particular according thereto, characterized in that both vertical sections ( 13 , 18 ) run obliquely. 12. Reinforcement element according to one or more of the preceding claims or in particular according thereto, characterized in that both vertical sections ( 13 , 18 ) extend at 45°. 13. Reinforcing element according to one or more of the preceding claims or in particular according thereto, characterized in that an individual element ( 8 ) consists of a bendable ribbed structural steel. 14. Reinforcing element according to one or more of the preceding claims or in particular according thereto, characterized in that the transverse connection is formed by welded rods ( 9 ) running perpendicular to the individual elements ( 8 ). 15. Ceiling ( 1 ) supported by a free-standing column ( 3 ), the ceiling ( 1 ) having two vertically spaced reinforcement mats ( 4 , 5 ) and a punching shear reinforcement being formed in the overlap to the column ( 3 ), characterized in that the punching shear reinforcement consists of a reinforcement element ( 7 ) according to one or more of claims 1 to 12.