EP2940227B1 - Planar component, shearing force reinforcement element and reinforced concrete/prestressed concrete component with a shearing force reinforcement made of such shearing force reinforcement elements - Google Patents

Description

The invention relates to the field of reinforced concrete and prestressed concrete construction, in particular the transverse force reinforcement of reinforced concrete / prestressed concrete components.

State of the art

In the case of reinforced concrete / prestressed concrete components, reliable transverse force reinforcement is necessary in the area of support points, in particular in the area of column connections, in order to absorb the transverse forces occurring there as a result of the column forces.

The WO2004 / 081313A1 describes a reinforcement element, designed as a flat body with holding means for at least partially gripping a reinforcing bar of a lower and upper reinforcement layer of a steel or prestressed concrete part. The reinforcement element connects the lower and upper reinforcement layers with one another in a non-positive manner and significantly increases the shear load capacity of the steel or prestressed concrete part.

The DE102009056826A1 describes a reinforced concrete / prestressed concrete component with at least one upper and at least one lower longitudinal reinforcement layer and a transverse force reinforcement that can absorb large shear forces and transverse forces and can be manufactured inexpensively as an in-situ concrete part and also as a semi-finished part. These advantageous properties are achieved in that the transverse force reinforcement is formed from at least 20 L-shaped sheet metal parts 20 made of structural steel, each with one or two brackets 30, which are fastened with their bracket arches 34 in a straight longitudinal recess 22 of the associated sheet metal part 30 designed as a horizontal elongated hole and its dimensions are guided over the uppermost longitudinal reinforcement layer Boo and the lowermost longitudinal reinforcement layer Buu. The horizontal longitudinal recess 22 has a feed area Z with an opening 28 suitable for introducing a bow 34 on a side edge of the L-shaped sheet metal part 20. Furthermore, the straight longitudinal recess 22 has a fastening region BF in which the bow arches 34 are fixed by one or two brackets 30. Both the feed area Z and the fastening area BF run horizontally and flow smoothly into one another.

Fig. 1 (State of the art) shows a schematic representation of such a known transverse force reinforcement element Q, consisting of an L-shaped sheet metal part 20 and a bracket 30. The transverse force reinforcement element Q is shown in the installed state, in which it is with the lower and the upper longitudinal reinforcement of a reinforced concrete / Prestressed concrete component is connected. The L-shaped sheet metal part 20 is connected to the lower longitudinal reinforcement, consisting of the longitudinal reinforcement layers Bu, Buu, while the bracket 30 installed in the horizontal longitudinal recess 22 establishes the connection with the upper longitudinal reinforcement, consisting of the longitudinal reinforcement layers Bo, Boo. For this purpose, it rests with its stirrup shoulders 32, which protrude to the front or rear from the plane of the drawing, on two bars of the uppermost longitudinal reinforcement layer Boo, while the stirrup arch 34 is positioned in the fastening area BF of the horizontal longitudinal recess 22. The positioning of the bow 34 is only possible in that it is inserted through the opening 28 into the feed area Z and, following its horizontal course, is guided into the fastening area BF. The bow 34 can only be moved horizontally. To secure the position of the bracket 30 in the fastening area BF of the horizontal longitudinal recess 22, a metal clip part 24 is provided which, after the bracket 30 has been installed, is pushed in the direction of the arrow onto a locking lug 27 formed by two rectangular recesses 25, 26 and engaged.

The connection of the L-shaped sheet metal part 20 to the lower longitudinal reinforcement is achieved by equipping the L-shaped sheet metal part 20 with a bevel 40 protruding from the plane of the drawing (forming the L-shape), which surrounds the lowermost longitudinal reinforcement layer Buu. In addition, two circular recesses 50 are arranged directly above the fold 40, through which two bars of the lowermost reinforcement layer Buu are passed. These two measures ensure a secure bond between the L-shaped sheet metal part 20 and the lowermost longitudinal reinforcement layer Buu.

The bracket 30, which rests with its shoulders on two bars of the uppermost longitudinal reinforcement layer Boo, assumes an angle of inclination α with respect to the vertical which can be up to 45 °. The bracket length H _{B is} given by H _B = h _B / cosα, where h _{B is} the minimum bracket length that a vertically aligned, with its stirrup shoulders 32 would have stirrups 30 resting on the bars of the uppermost longitudinal reinforcement layer Boo.

Disadvantages of the prior art

• Es ist erforderlich, lange Bügel 30 zu verwenden, deren Bügellänge H_B um einen Faktor, der bis zu √2 betragen kann, größer ist als die minimale Bügellänge h_B. Der Materialverbrauch für solche Bügel ist unnötig hoch.
• Die Bügel liegen im eingebauten Zustand sehr schräg, unter einem Neigungswinkel α gegenüber der Vertikalen, der bis zu 45° beträgt. Der Bügel kann also um bis zu 90° verschwenkt eingebaut werden. Dabei besteht die Gefahr, den Bügel 30 in eine Endlage zu bringen, in welcher er aus seiner optimalen Lage, in der er im fertigen Stahlbeton-/Spannbetonelement Zugspannungen aufnimmt, stark ausgelenkt ist (d. h. unter Druckspannung gesetzt und somit funktionslos ist).
• Die von einem Operator beim manuellen Einziehen der Bügel 30 aufzubringende Kraft ist hoch.
• Bei ungünstigen geometrischen Randbedingungen, insbesondere bei einer Kollision mit einem (oder mehreren) Stäben der oberen Längsbewehrungslage Bo, ist das Einziehen eines Bügels 30 nur möglich, wenn durch temporäres Entfernen dieses Stabes/dieser Stäbe der oberen Längsbewehrungslage Bo ein für das Einziehen des Bügels ausreichend großer Freiraum R hergestellt wird. Es ist somit nicht möglich, die obere Längsbewehrung Bo, Boo in Form von Bewehrungsmatten auszuführen.

Practical tests have shown that the positioning of one or two brackets 30 in the straight longitudinal recess 22 of an L-shaped sheet metal part 20 according to the prior art is only possible by manually pulling the bracket 30 into the straight longitudinal recess 22 designed as a horizontal slot. The following disadvantages associated with this pull-in have been identified:

• It is necessary to use long stirrups 30, the stirrup length H _{B of} which is greater than the minimum stirrup length h _B by a factor which can be up to √2. The material consumption for such hangers is unnecessarily high.
• When installed, the brackets are very inclined at an angle of inclination α to the vertical which is up to 45 °. The bracket can therefore be installed pivoted by up to 90 °. There is the risk of moving the bracket 30 into an end position in which it is strongly deflected from its optimal position, in which it absorbs tensile stresses in the finished reinforced concrete / prestressed concrete element (ie it is placed under compressive stress and thus has no function).
• The force to be applied by an operator when manually pulling in the bracket 30 is high.
• In the case of unfavorable geometric boundary conditions, in particular in the event of a collision with one (or more) bars of the upper longitudinal reinforcement layer Bo, the pulling in of a bracket 30 is only possible if, by temporarily removing this bar (s) from the upper longitudinal reinforcement layer Bo, one is sufficient for pulling in the bracket large free space R is established. It is therefore not possible to implement the upper longitudinal reinforcement Bo, Boo in the form of reinforcement meshes.

Reinforcement meshes are prefabricated components in which the bars of the two longitudinal reinforcement layers Boo and Bo are welded to form a grid, i.e. are already fixed. Compared to single reinforcing bars, they can be laid much faster and more precisely. Their use is an essential prerequisite for the efficient production of reinforced concrete / prestressed concrete construction elements.

The problems occurring when pulling in the bracket 30 according to the prior art are worked out in detail below and with the aid of Fig. 1 illustrated.

To do this, in Fig. 1 In addition to the end position of the bracket 30, four other positions, labeled 1 to 4, are shown in dashed lines, which the bracket 30 assumes in chronological order during the retraction before it is finally brought into the end position 5 (with an angle of inclination α relative to the vertical) . In addition, the direction of movement of the bracket 30 is marked by a dashed arrow. The positioning of a bracket 30 in its end position 5 in the straight longitudinal recess 22 of an L-shaped sheet metal part 20 proceeds as follows:
First, the bow 34 of the bow 30 is lowered by the upper longitudinal reinforcement Boo, Bo, guided directly in front of the opening of the straight longitudinal recess 22 (position 1) and then subjected to a tensile force F _{Z , which is a tangential component F II} pointing in the longitudinal direction of the straight longitudinal recess 22 owns. So that such a tangential component arises, the bracket 30, starting from the vertical, must be inclined by an angle β in the direction of the straight longitudinal recess 22 (positions 2, 3). The tangential _{component F II} = F _Z · sinβ of the tensile force F _Z pulls the bow 34 into the straight longitudinal recess 22 (movement from position 3 to position 4), the normal _component F ⊥ = F _Z · cosβ of the tensile force F _Z during the drawing in leads to undesired friction of the bow 34 on the upper side of the straight longitudinal recess 22. At small angles β, the desired tangential _{component F II is} small, while the undesired normal component F ⊥ is large, so that the operator has to _{apply a large tensile force F Z} , which leads to his rapid fatigue. The formulas F _II = F _Z · sin β and F _⊥ = F _Z · cos β show that it is possible to increase _{F II and to decrease F ⊥} by increasing the angle of inclination β of the bracket 30 when it is drawn in. This is achieved by long brackets 30, which can be drawn at an angle of inclination β≈25 ° ... 40 ° and in the end position assume an angle of inclination α = 30 ° ... 45 ° relative to the vertical. The maximum permissible bracket length H _B for such brackets is H _B = h _B √2 (for an angle of inclination a = 45 °), i.e. it is more than 40% longer than the minimum bracket length h _B , combined with the corresponding additional consumption of material .

When the bow 34 has reached its target position in the fastening area BF, the bow shoulders are placed on two bars of the uppermost longitudinal reinforcement layer Boo. The bracket 30 thereby reaches its end position (position 5), in which it assumes the angle of inclination α with respect to the vertical.

(The relationship between F _Z , F _II , F _⊥ and β is in Fig. 1 shown schematically at position 3. At position 5, the angle of inclination α of the bracket is shown in the end position.)

Fig. 1 illustrates yet another disadvantage of drawing in, which in practice has turned out to be the most serious:
The stirrup legs of the stirrup 30 (these are the two stirrup sections that connect the two stirrup shoulders 32 to the stirrup arch 34) must be movable parallel to the bars of the uppermost reinforcement layer Boo over a very long horizontal free space R during the pulling in. Fig. 1 shows that this free space R must correspond to at least twice the width of the L-shaped sheet metal part 20 in order to ensure convenient and quick pulling in and thus a rational and economical workflow on the construction site.

In order to ensure this horizontal free space R, no bars of the upper longitudinal reinforcement layer Bo running at right angles to the uppermost longitudinal reinforcement layer Boo may be located in its area. In Fig. 1 three bars of the upper longitudinal reinforcement layer Bo are shown, the middle bar, shown with a dashed border, being in a position within the free space R which makes it impossible for the bracket 30 to be drawn in. This rod must be temporarily removed in order to be able to pull in the bracket 30. Such a temporary removal of reinforcing bars is completely uneconomical and normally not possible at all, since reinforcement mats are usually used in which the bars of the two longitudinal reinforcement layers Boo and Bo are welded to a grid, i.e. are already fixed.

It is extremely time-consuming and impossible due to the time and cost pressure on the construction site to position the L-shaped sheet metal parts 20 in such a way that above each L-shaped sheet metal part 20 the in Fig. 1 shown, very long horizontal free space R for drawing in the bracket 30 is reserved. In addition, certain distances between the individual shear force reinforcement elements Q must be observed so that the positions the L-shaped sheet metal parts 20 in in-situ concrete parts may not be changed arbitrarily for the purpose of adapting to the upper longitudinal reinforcement. In the case of semi-finished parts, this is impossible anyway, since the lower section of the L-shaped sheet metal parts 20 has already been cast with concrete.

Thus, the L-shaped sheet metal parts 20 with attached brackets 30 cannot be used in connection with an upper longitudinal reinforcement Boo, Bo implemented by reinforcement mats, which excludes their rational and economical use as transverse force reinforcement elements.

In their end position in the installed state, the brackets 30 should be directed in the direction of the tensile stresses occurring in the reinforced concrete / prestressed concrete component in order to absorb them. These tensile stresses are inclined relative to the vertical, their angle of inclination, which differs for the individual transverse force reinforcement elements Q, is usually not exactly known. In practice, therefore, as a good compromise, perpendicular or almost perpendicular brackets are used. Since these stirrups establish the connection between the L-shaped sheet metal parts 20 and the upper longitudinal reinforcement Bo, Boo on the (almost) shortest path, their stirrup length H _B may only slightly exceed the minimum stirrup length h _B , preferably by no more than 6% . The installation of the bracket 30 by means of pulling in, however, excludes short brackets 30 that assume a vertical (a = 0) or at least almost vertical (α <20 °) end position in the finished reinforced concrete / prestressed concrete component. Therefore, the desired embodiment of a transverse force reinforcement, consisting of L-shaped sheet metal parts 20 with (almost) vertical brackets 30, is not even approximately feasible.

Thus, in the prior art, there is a tension between the use of long stirrups, which reduce the effort required by an operator when pulling in, and the use of short stirrups, which are absolutely preferable for the production of effective transverse force reinforcement.

Object of the invention

The object of the present invention is to eliminate the described disadvantages of the prior art and to provide a transverse force reinforcement element comprising short stirrups secured in position.

Solution of the task

This object is achieved according to the invention by a flat component 21 according to claim 1, which has a feed area designed as a recess A, by a transverse force reinforcement element Q according to claim 10, by a reinforced concrete / prestressed concrete component according to claim 13 and its use according to claim 15 and by the Advantageous embodiments formulated in subclaims. The flat, preferably rectangular, component 21 forms the transverse force reinforcement element Q with at least one bracket 30 that can be connected to the flat component 21. The terms used below with regard to the orientation of the flat component 21 (e.g. lower section) relate to its Alignment after installation in a reinforced concrete / prestressed concrete component. The flat component 21 is equipped in its lower section with at least one holding means for fastening to the lower longitudinal reinforcement of this reinforced concrete / prestressed concrete component. These holding means include sufficiently large recesses 50 for fastening the flat component 21 on bars of the lowest longitudinal reinforcement layer Buu as well as an optional fold 40 directly below the recess (s) 50. The optional fold 40 is designed at a right angle and is used for additional stabilization of the flat Component 21 in that it rests directly on the undersides of bars of the lowermost reinforcement layer Buu positioned in the recesses 50. Because of this additional stabilizing function, the execution of the flat component 21 with a bevel 40 is absolutely to be preferred.

The flat components 21 have a fastening area BF designed as a recess, which is located in the vicinity of the center line M of the flat component 21 and is suitable for positioning the bow arches 34 of one or two brackets 30. According to the invention, the flat components also have a feed area designed as a recess A and connected to the fastening area BF, which allows a bow 34 to be fed to the fastening area BF in a large angular range, the feed angle ζ, measured starting from the horizontal, between at least 10 ° and 120 ° can be varied, making it easier to feed the bracket. The recess A can be narrowed so that it is the feed of a bow 34 allowed in a preferred angular range or at a preferred feed angle ζ.

The reinforced concrete / prestressed concrete component has an upper and a lower longitudinal reinforcement, wherein the upper longitudinal reinforcement can be implemented both in the form of individual reinforcement bars and, in an advantageous embodiment, in the form of reinforcement mats, and is provided with a transverse force reinforcement, consisting of a suitable number of the inventive Shear force reinforcement elements Q made of flat components 21 are equipped with stirrups 30 attached to them, the dimensions of which are guided over the uppermost longitudinal reinforcement layer Boo and the lowermost longitudinal reinforcement layer Buu. Practical tests and simulations have shown that such a transverse force reinforcement made up of preferably at least 20 transverse force reinforcement elements Q ensures the required load-bearing capacity of the reinforced concrete / prestressed concrete component.

Furthermore, the object of the invention is achieved by specifying a method in which a bracket 30 is installed in a flat component 21 by pressing it in. In their end position, the brackets 30 assume a small angle of inclination α, which is in the range α <20 °, preferably α <10 °. In the ideal case, the brackets 30 are aligned vertically in the end position (α = 0). The small angle of inclination α is ensured by using short brackets 30, the bracket length H _{B of} which exceeds the minimum bracket length h _B by an amount 6%. Such brackets 30 assume an angle of inclination α <20 ° in the end position. The temple lengths H _B = 1.02 · h _B and H _B = h _B are particularly preferred.

Detailed representation of the solution according to the invention Part 1 of the solution: Flat component 21 according to the invention, shear force reinforcement element Q and reinforced concrete / prestressed concrete component equipped with it

A large number of tests with flat components that had different shapes of longitudinal recesses showed that the object of the invention is optimally achieved by a flat, preferably rectangular, component 21 and at least one bracket 30 that can be connected to the flat component 21. The flat component 21 is in its lower section with at least one holding means equipped for fastening to the lower longitudinal reinforcement of a reinforced concrete / prestressed concrete component. These holding means include sufficiently large recesses 50 for fastening the flat component 21 on bars of the lowest longitudinal reinforcement layer Buu and an optional fold 40 directly below the recess (s) 50. The recesses 50 can lie completely inside the flat component 21, so that one per bar the lowermost reinforcement layer Buu can be passed through the recesses 50. In order to prevent the flat component 21 from being able to rotate about such a rod, the flat component 21 advantageously has two recesses 50 for positioning such rods which securely fix the flat component 21. Instead of being completely inside the flat component 21, the recesses 50 can also be designed to be open or semi-open to the side edges of the flat component 21. In this case, a bar of the lowermost reinforcement layer Buu can be inserted from the sides into a recess 50 of the flat component 21. The optional fold 40 is designed at a right angle and offers the possibility of additional stabilization of the flat component 21 in that it rests directly on the undersides of bars of the lowest reinforcement layer Buu positioned in the recesses 50. The fold 40 is advantageously provided with additional recesses (can be seen in Figure 2c below), which allow the passage of fastening wires with which the fold 40 is drawn to the bars of the lowest reinforcement layer Buu, so that the flat component 21 is fixed in a tilt-proof and immovable manner (so-called tying). Because of this additional stabilizing function, the execution of the flat component 21 with a bevel 40 is absolutely to be preferred.

The flat component 21 has a fastening area BF designed as a recess, which is located in the vicinity of the center line M of the flat component 21 and is suitable for positioning the bow arches 34 of one or two brackets 30. The fastening area BF is designed in such a way that after the flat component 21 has been installed in a reinforced concrete / prestressed concrete component it has a defined distance from the upper longitudinal reinforcement. The fastening area BF is therefore preferably designed as a horizontal elongated hole. In order to enable the bracket 30 to be fixed in a more stable manner, it can also be inclined slightly be designed or have an additional recess on its upper side (in the direction of the upper edge of the flat component 21) to accommodate the bow arches 34.

According to the invention, the planar component 21 also has a feed area designed as a recess A and connected to the fastening area BF, which allows a bow 34 to be fed to the fastening area BF in a large angular range, the feed angle ζ, measured starting from the horizontal, between at least 10 ° and 120 ° can be varied. A recess A, which allows this large angular range, extends over an area delimited by the upper section of a side edge and part of the upper edge of the flat component 21, in FIG Fig. 2a area marked by a dashed line. Fig. 2a shows that the feeding of a bow 34 can be extremely variable, e.g. B. at angles of 10 °, 30 °, 45 °, 60 °, 90 ° and 120 °, which is illustrated by the arrows labeled a to f in this order.

According to the invention, the recess A is narrowed in such a way that it allows a bow 34 to be fed in only at a selected feed angle, which is likewise to be selected from the range 10 ° ζ ζ 120 °. Preferred feed angles are ζ = 30 °, ζ = 45 °, ζ = 60 °, a particularly preferred angle is ζ = 45 °. In these cases, the feed area formed by the recess A narrows to a feed channel S in the form of an obliquely upwardly directed elongated hole with an opening 29 to the outside, which is suitable for feeding a bow 34. Such a feed channel S forms an angled longitudinal recess 23 with the fastening area BF.

Due to the inclined course of the feed channel S (after the flat component 21 has been installed in a reinforced concrete / prestressed concrete component), the distance between the opening 29 and the upper longitudinal reinforcement is less than the distance between the fastening area BF and the upper longitudinal reinforcement. This feature is a decisive prerequisite for the use of short stirrups 30. The feed channel S is preferably designed in a straight line, but it can also be designed in an arc shape, the arc radius should correspond to the distance between the fastening area BF and the upper longitudinal reinforcement.

The vertical positioning of the fastening area BF and the height of the flat component 21 result from the following considerations: The distance between the fastening area BF and the lower, preferably beveled, side of the flat component 21 must be so large that the fastening area BF remains freely accessible, when the flat component 21 is built into a reinforced concrete / prestressed concrete component designed as a semi-finished part, the lower part of which has already been cast with concrete. Since the grouting height in practice extends 4 cm to 6 cm above the lower longitudinal reinforcement, the fastening area BF should be at least 7 cm from the lower side of the flat component 21. In order to ensure that the flat component 21 also has the necessary stability in the area of the angled longitudinal recess, at least one third of its area should be above the fastening area BF. On the other hand, the flat component 21, installed in a reinforced concrete / prestressed concrete component, must have a sufficient distance from its upper longitudinal reinforcement, even with reinforced concrete / prestressed concrete components of small thickness (close to or equal to a minimum thickness of 18 cm). A flat component 21 with a height between 11 cm and 12 cm and a fastening area BF which is 7 cm to 8 cm away from the lower side of the flat component 21 achieves the object according to the invention.

The flat component 21 and the bracket 30 must consist of a material with high tensile strength. Suitable materials that combine high tensile strength with easy machinability are structural steel and reinforcing steel, with structural steel being preferred for the flat components 21, while reinforcing steel is preferred for the stirrups 30. The flat component 21 should have a thickness of at least 1 mm when manufactured from structural steel, preferred thicknesses are 3 mm and 5 mm. Ribbed reinforcing steel with a nominal diameter of 6 mm is preferably used for the bracket 30. Other materials with high tensile strength can also be used, with the dimensions possibly having to be adapted by a person skilled in the art. Figure 2b shows the schematic representation of an advantageous embodiment of a flat component 21 according to the invention, which is equipped with an angled longitudinal recess 23. Since it is preferably made of structural steel and has an optional, but absolutely recommended, bevel 40 which gives it an L-shaped cross section, it is referred to below and in all exemplary embodiments as an L-shaped sheet metal part 21. One or two brackets 30 (in Figure 2b not shown) installable.

On the lower edge of the feed channel S of the angled longitudinal recess 23 and on the side edge of the L-shaped sheet metal part 21 there are two recesses 25a and 26a, which form a locking lug 27a, on which a clip sheet metal part 24a for fixing and securing the position of the bracket 30 can be locked by it towards the in Figure 2b shown arrow is pushed. In order to ensure that the metal clip part 24a latches securely, the recess 25a is preferably rectangular. The shape of the recess 26a is largely freely selectable. It is preferably designed as a triangle that is just large enough that the clip plate part 24a can be installed. Thus, the load-bearing capacity of the L-shaped sheet metal part 21 is not impaired by the recess 26a. The feed angle ζ at which a bow 34 can be fed is determined in this embodiment by the angle of inclination γ of the feed channel S with respect to the fastening area BF (ζ = γ). The angle of inclination γ can be selected from the same range as ζ. The range 30 ° γ 60 ° is preferred, in which short brackets 30 can also be safely fed, the angles γ = 30 °, γ = 45 ° and y = 60 °, ie the angles also preferred for ζ, are particularly preferred. The lengths L _{S of} the feed channel S and L _{BF of} the fastening area BF can be varied relative to one another, the equation L _S · cos γ + L _BF = T applies. T is the depth of the longitudinal recess 23 (starting from the side edge of the L-shaped sheet metal part). The depth T of the angled longitudinal recess 23 preferably extends by one bracket diameter beyond the center line M of the L-shaped sheet metal part 21, so that the fastening area BF lies exactly in the area of the center line M and the L-shaped sheet metal part 21 is thus evenly loaded. In order to increase the load-bearing capacity of the L-shaped sheet metal part 21, however, as in FIG Figure 2b shown, a smaller depth T can be selected. The length L _{BF of} the fastening area BF is selected and the positions of the recesses 25a, 26a for fastening the clip plate parts 24a are arranged in such a way that one or two bracket arches 34 can be inserted into the fastening area BF and secured in position by snapping in a clip plate part 24a.

An essential prerequisite for the installation of the bracket 30 is that the opening 29 of the angled longitudinal recess 23 is higher than the fastening area BF, which is ensured by the supply channel S running obliquely upwards from the fastening area BF to the opening 29. The difference in height HD between the opening 29 and the fastening area BF is given here by the projection L _S sin γ of the feed channel S onto the side edge of the L-shaped sheet metal part 21. A difference in height HD of 1 cm to 2 cm is sufficient for short Safe to install bracket.

In order to ensure a free mobility of a bow 30 in the longitudinal recess 23, the height of the longitudinal recess 23 must be slightly larger than the nominal diameter of the bracket 30, ie the nominal diameter of the bar material used to manufacture the bracket 30 (preferably reinforcing steel). The bracket surface is preferably ribbed, which means that the outer diameter of the bracket 30 is greater than its nominal diameter. The free mobility of the bow 30 in the longitudinal recess 23 is guaranteed in any case if the height of the longitudinal recess 23 is one third greater than the nominal diameter of the bracket 30. The ribbed bracket surface is a stable connection with the surrounding area in the finished reinforced concrete / prestressed concrete element Concrete and thus increases the load-bearing capacity of the reinforced concrete / prestressed concrete component. The angled longitudinal recess 23 can be modified in various ways: The feed channel S can also be designed to be curved. It is important that the height difference HD specified above is guaranteed even with an arcuate design of the feed channel. The fastening area BF can be inclined slightly upwards in the direction of the center line M in order to support the fixing of the bracket 30. A horizontal fastening area is preferred, since this has a defined distance from its upper longitudinal reinforcement after the L-shaped sheet metal part 21 has been installed in a reinforced concrete / prestressed concrete component. It is possible to provide the upper side of the fastening area BF with a recess which supports the fixing of the bow arches 34. The recess should have a small height of the order of 1 mm so that the distance to the upper longitudinal reinforcement is only slightly increased. If a slightly inclined fastening area BF is selected, it should likewise only increase along its length by a small amount, on the order of 1 mm, in the direction of the center line M.

In order to achieve the object of the invention to achieve a small angle of inclination α of the bracket 30 in the end position (α <20 °, preferably α <10 °, ideally a = 0), the following considerations for choosing the bracket length H _{B are} helpful:
The minimum temple length h _B is how Fig. 3 shows, given by the distance from the upper edge of the fastening area BF of the angled longitudinal recess 23 to the upper edge of the uppermost longitudinal reinforcement layer Boo plus twice the nominal diameter of the bracket 30. The angle of inclination α of the bracket in the end position is due to cosa = h _B / H _B by the ratio the bracket length H _B to the minimum bracket length h _{B is} determined. In the case of an inclined bracket, the bracket shoulders have a lateral offset V with respect to the bracket arch (see Fig. 3 ) on.

Exemplary quantitative information can be found in the following table: H _B cos α α V (at h _B = 12 cm) V (at h _B = 30 cm) 1.41 · h _B 0.71 45 ° 12 cm 30 cm 1.15 · h _B 0.87 30 ° 6.9 cm 17.3 cm 1.07 · h _B 0.93 20.8 ° 4.6 cm 11.4 cm 1.06 · h _B 0.94 19.4 ° 4.2 cm 10.6 cm 1.05 · h _B 0.95 17.8 ° 3.9 cm 9.6 cm 1.04 · h _B 0.96 15.9 ° 3.4 cm 8.6 cm 1.03 · h _B 0.97 13.9 ° 3.0 cm 7.4 cm 1.02 · h _B 0.98 11.4 ° 2.4 cm 6.0 cm 1.01 · h _B 0.99 8.1 ° 1.7 cm 4.3 cm 1.00 · h _B 1 0 ° 0 cm 0 cm

According to the above definition of characterizing the bracket 30 with an angle of inclination in the end position a <20 ° as a short bracket, the bracket 30 with bracket lengths 1.00 · h _B ≤ H _B ≤ 1.06 · h _B in the above table are short Stirrups, the stirrups with stirrup lengths H _B = 1.07 · h _W , 1.15 · h _W , 1.41 · h _{B are to} be classified as long stirrups.

In order to be able to safely install the stirrups 30 even when using reinforcement mats as the upper longitudinal reinforcement of a reinforced concrete / prestressed concrete component, the lateral offset V must be less than half the bar spacing in the reinforcement mat. A common rod spacing is 15 cm. The table shows that in the case of a minimum bracket length h _B = 12 cm (suitable for an approximately 24 cm thick reinforced concrete / prestressed concrete _{component) brackets of length H B} = 1.06 · h _B can be safely installed. In the case of a minimum bracket length h _B = 30 cm (suitable for an approximately 42 cm thick reinforced / prestressed concrete component), the lateral offset V for brackets of bracket length H _B = 1.06 · h _{B would} already be too large. Brackets of the bracket length (H _B ≤1.03 · h _B ) are required. Theoretically, it is possible to select stirrups 30 with the minimum stirrup length h _B , which are vertical in the end position (a = 0). In practice, however, manufacturing tolerances must always be taken into account, which can lead to deviations in the length of the temple. It is therefore not sensible to use bracket 30 with the minimum bracket length h _B , since some of these brackets could prove to be too short and therefore not fit for installation. Brackets 30 of bracket length H _B = 1.02 · h _B represent a suitable compromise. They have a small angle of inclination in the end position (α = 11.4 ° if the bracket length is strictly adhered to) and do not run the risk of not being able to be installed due to manufacturing tolerances be. In the context of this invention, however, brackets 30 with a shorter bracket length (1.01 · h _B ) including the minimum bracket length h _{B are also} claimed, since such brackets will become practical in the future due to decreasing manufacturing tolerances. The saving of rod material should be mentioned as an advantageous side effect of using short brackets 30.

One advantage of the transverse force reinforcement element Q is that it can be adapted to reinforced concrete / prestressed concrete components of different thicknesses by varying the stirrup length H _B. Identical L-shaped sheet metal parts 21 can thus be used for reinforced concrete / prestressed concrete components of different thicknesses.

Embodiment 1 (regarding the L-shaped sheet metal part 21)

Figure 2c shows in front view (top left), side view (top right) and plan view (bottom) a specific embodiment of the L-shaped sheet metal part 21 according to the invention, as it is intended for practical use. The reference numbers that consist of Figure 2b are directly transferable, have been omitted in order to be able to clearly show all dimensions and tolerances (always in millimeters). Only a latched metal clip part 24a is shown with reference numerals in order to clarify its function as a position securing device.

The L-shaped sheet metal part 21 consists of structural steel with a thickness of 3 mm or 5 mm and is manufactured inexpensively as a free-falling stamped part. It has a height of 116 mm or 118 mm (resulting from the different thicknesses) and a width of 69 mm. The selected width results from the conditions of use of the L-shaped sheet metal parts in practice: Several L-shaped sheet metal parts are threaded onto bars of the lowest reinforcement layer Buu (by passing the bars through the recesses 50), so that a line element is created that acts as additional reinforcement between the Bars of an already existing lowest longitudinal reinforcement layer Buu is inserted into the base body (reinforcement arrangement before pouring with concrete) of a reinforced concrete / prestressed concrete component. The bars of the existing longitudinal reinforcement layer Buu usually have a gap of 10 cm or 15 cm. A line element with L-shaped sheet metal parts 21 of the selected width of 69 mm can be conveniently placed in this gap in both cases, with the resulting overall arrangement of the bars of the lowest longitudinal reinforcement layer Buu having approximately equidistant bar gaps. Of course, the width of the L-shaped sheet metal parts 21 can be optimized taking into account the specific conditions of use. The angled longitudinal recess 23 has a depth T = (30 ± 1) mm. The feed channel S of the angled longitudinal recess 23 is inclined by γ = 45 ° with respect to the horizontally extending fastening area BF, which has a length of (16 ± 1) mm, so that the feed angle is ζ = 45 °. A height difference HD between the opening 29 and the fastening area BF of the angled longitudinal recess 23 of the L-shaped component 21 of 14 mm is realized. Via the feed channel S, the bow arches 34 (not shown) of one or two brackets are 30 can be pressed into the fastening area BF. The angled longitudinal recess 23 has a height of 8 mm, so that the bracket 30, consisting of reinforcing steel with a nominal diameter of 6 mm, can move freely in the angled longitudinal recess 23.

Part 2 of the solution: According to the invention, pressing the bracket 30 into the angled longitudinal recesses 23 of the L-shaped sheet metal parts 21 Initial situation before the impression:

A base body for a reinforced concrete / prestressed concrete component is provided which is equipped with the required number of L-shaped sheet metal parts 21 according to the invention with angled longitudinal recess 23. The L-shaped sheet metal parts 21 are connected to the lower longitudinal reinforcement Buu, Bu in the manner described above. The reinforced concrete / prestressed concrete component can be implemented as a semi-finished part or as an in-situ concrete part. In the execution as a semi-finished part, the lower part of the base body is already cast with concrete at the factory, the casting height being selected so that the angled longitudinal recesses 23 for installing the bracket 30 and the recesses 25a, 26a for installing the clip plate parts 24a remain free. This is guaranteed in any case by a grouting height of 4 cm to 6 cm. In the case of the in-situ concrete part, the concrete is poured completely on the construction site. The upper longitudinal reinforcement, consisting of the longitudinal reinforcement layers Boo and Bo, is already in place in both embodiments. Due to the equipment with the L-plates 21 according to the invention with angled longitudinal recesses 23, the upper longitudinal reinforcement can be designed as a reinforcement mat, in which the two longitudinal reinforcement layers Bo and Boo are welded together and thus the horizontal free space R available for installing the bracket 30 can no longer be changed. This design of the upper reinforcement as a reinforcement mat is absolutely to be preferred, as it can be laid much faster, more precisely and more cost-effectively compared to individual reinforcing bars.

Procedure of the pressing process:

To push in, the bracket legs of a prefabricated bracket 30 of length H _B , which is selected as described above, are lowered through the upper reinforcement by an operator so that the bracket arch 34 connecting the two bracket legs is positioned directly in front of the opening 29 of the angled longitudinal recess 23. The bracket 30 is preferably held at a small angle of inclination β with respect to the vertical (β <10 °) or even vertically during the lowering process. However, as will be explained in more detail in exemplary embodiment 3, it is possible, if necessary, to incline the bracket 30 to a significantly greater extent, in particular to avoid a collision with a bar of the upper longitudinal reinforcement layer Bo. Due to the obliquely upwardly directed feed channel S of the angled longitudinal recess 23, its opening 29 is offset upwards, so that the bow 34 of a more inclined bow 30 can be positioned in front of the opening 29. The angle of inclination β of the bracket 30 during the pressing-in can thus be greater than the angle of inclination α that the bracket 30 assumes in the end position.

As soon as the bow 34 is positioned immediately in front of the opening of the angled longitudinal recess 23, a compressive force F _{D is} exerted on the bow 30 by the operator, which moves the bow 34 through the opening 29 of the angled longitudinal recess 23 in its feed channel S and further through the Feed channel S leads into the fastening area BF of the angled longitudinal recess 23. Surprisingly, it was found that a low compression force F _D is sufficient for this, which is very much smaller than the tensile force F _Z required when drawing in according to the prior art. As the cause of this advantageous effect, it has been found that there is no obstructive friction of the bow 34 on the upper edge of the longitudinal recess 23 when it is pressed in. The bow 34 slides almost frictionlessly into the fastening area BF. The bracket shoulders 32 of the bracket 30 are then placed on two bars of the uppermost longitudinal reinforcement layer Boo, the bracket 30 in this end position assuming an angle of inclination α caused _{by the bracket length H B.}

During the entire pressing-in process, the upper part of the bracket 30 formed by the bracket shoulders 32 only needs to be in a very short horizontal free space R can be moved. A free space R which corresponds to the depth T of the angled longitudinal recess 23 is always sufficient for comfortable work. Also an even smaller free space R with a length that is only a few millimeters larger than the outer diameter of the bracket 30 and thus just allows the bracket 30 to be passed between two very close rods of the upper longitudinal reinforcement layer Bo and it at an angle β tilting, which should be up to 45 °, is already sufficient for the indentation. For example, if the outside diameter of the bracket is 8 mm (a value that is common in practice), a free space R of length 8 mm · √2≈12 mm is sufficient to pass the bracket 30 inclined by 45 ° through the upper longitudinal reinforcement. In practice, however, the available free space R is always significantly greater, since the distance between two reinforcing bars in commercially available reinforcement meshes is 10 cm or 15 cm as standard. It is thus always possible without any problems to press the bow arches 34 into the angled longitudinal recesses 23 of the L-shaped sheet metal parts 21. Choosing a short bracket length H _B ensures that the bracket 30 assumes a small angle of inclination α after its shoulders have been placed on two bars of the uppermost longitudinal reinforcement layer Boo, so that the bracket shoulders 32 have a slight lateral offset V, preferably V <5 cm . A free space of R≤5 cm is thus sufficient to bring the bracket 30 into its end position. This free space R is always given, starting from the vertical, in at least one of the two possible directions for laying down the bow shoulders 32.

When the installation of the brackets 30 has been completed for all L-shaped sheet metal parts 21, the reinforced concrete / prestressed concrete component is completed by pouring it with concrete.

For the individual L-shaped sheet metal parts 21, when the stirrups 30 are pressed in, depending on the respective position of the bars of the upper longitudinal reinforcement layer Bo, several significantly different situations are possible, which are described in the following exemplary embodiments.

Embodiment 2: Above the angled longitudinal recess 23 of the L-shaped sheet metal part 21 there is no rod of the upper reinforcement layer Bo

In this in Fig. 3 illustrated situation, the required horizontal free space R is optimally positioned, so immediately available. A simple statistical estimate shows that this advantageous situation is present in more than 70% of the L-shaped sheet metal parts 21. This in Fig. 3 L-shaped sheet metal part 21 shown has the in Figure 2c specified dimensions. A bracket 30 with bracket length H _B = 1.03 · h _{B is} used, which is therefore 3% greater than the minimum bracket length h _B , which is 16 cm here. Thus, the temple length H _B is 16.5 cm. When pressed in, the bow 34 is guided by the compressive force F _D acting on the bow 30 via positions 1 and 2 into the fastening area BF of the angled longitudinal recess 23. The bracket is then inclined to the left into its end position 3, whereby it assumes an angle of inclination α≈14 °. It can be seen that a free space R of approximately 3 cm is sufficient to press in the stirrup 30 and place it with its stirrup shoulders 32 on two bars of the uppermost longitudinal reinforcement layer Boo. When arranged in Fig. 3 it is also possible to put the bracket 30 to the right, because the necessary free space is also available. Likewise, two brackets 30 can be pressed in, one being deposited to the right and the other to the left.

Embodiment 3: Above the angled longitudinal recess 23 of the L-shaped sheet metal part 21 there is a rod of the upper reinforcement layer Bo

A bar of the upper reinforcement layer Bo located above the angled longitudinal recess 23 of the L-shaped sheet metal part 21 hinders the movement of the stirrup legs 32 parallel to the bars of the uppermost reinforcement layer Boo. Three corresponding situations (I, II, III) are in Fig. 4 shown. In total, they are present in less than 30% of the L-shaped sheet metal parts 21. Here there is no optimally positioned horizontal free space of length T above the angled longitudinal recess 23 of the L-shaped sheet metal part 21, but there are horizontal free spaces on both sides of the bar of the upper reinforcement layer Bo, which acts as an obstacle with a length significantly greater than T, which are suitable in the same way as an optionally positioned horizontal free space for pressing in the bracket 30.

Brackets 30 of the minimum bracket length h _B are used, which are perpendicular or almost perpendicular in the end position. The bracket 30 is pressed in as in FIG Fig. 4 illustrated. It is shown how to proceed with three different positions of the bar acting as an obstacle in the upper reinforcement layer Bo.

In situation I, a bar of the upper reinforcement layer Bo is located vertically above the opening 29 of the angled longitudinal recess 23. Fig. 4 shows that the bracket 30 of minimum bracket length h _B , by being slightly inclined, can easily be moved past the obstructing rod (bracket position 1), its bracket bow 34 is pressed into the opening 29 of the angled longitudinal recess 23 and passed through the feed channel S (bracket position 2) and the bracket 30 can be brought into a vertical end position (bracket position 3). In this end position, the bow 34 is located in the fastening area BF of the angled longitudinal recess 23, while the bow shoulders 32 of the bracket 30 rest on two bars of the uppermost longitudinal reinforcement layer Boo. In this example, the bracket 30 has an angle of inclination α = 0 ° in the end position, while it had an angle of inclination β = 5 ° at the beginning of the pressing-in process (bracket position 1). In situation II, a bar of the upper reinforcement layer Bo is located vertically above the transition from the feed channel S to the fastening area BF of the angled longitudinal recess 23. Fig. 4 shows that a bracket 30 of minimum bracket length h _{B can} also be moved past the obstructing rod without any problems in this situation (bracket position 1). To do this (compared to situation 1) it only has to be brought into a slightly larger angle of inclination β (here β = 17 °). Its bow 34 is then pressed into the opening of the angled longitudinal recess 23 and guided through the feed channel S (bow position 2) into the fastening area BF of the angled longitudinal recess. Because of the bar of the upper reinforcement layer Bo positioned above the transition from the feed channel S to the fastening area BF, the bracket 30 cannot be brought into an exactly vertical end position here. However, it is possible to turn it into an almost bring vertical end position. Fig. 4 shows that in this example an angle of inclination α = 1 ° is already sufficient to guide the bracket 30 past the obstructing bar of the upper reinforcement layer Bo. In order to bring the bracket 30 into this end position, the operator only needs to slightly tighten the bracket shoulders 32.

In situation II, the clear advantages of the inventive L-shaped sheet metal part 21 with an angled longitudinal recess 23 over the prior art become apparent. For clarification, in Fig. 4 the same situation is shown for an L-shaped sheet metal part 20 according to the prior art.

In situation II, a bracket 30 of minimal bracket length h _B can be installed in an L-plate 21 according to the invention without any problems, since the opening 29 of the angled longitudinal recess 23 is also reached by the bracket bow 34 due to the upwardly inclined feed channel S from the bracket arch 34 when the bracket 30 minimum bracket length h _{B is brought} into a large angle of inclination (here β = 17 °). However, is how Fig. 4 shows that the installation of a bracket 30 of minimum bracket length h _B in an L-shaped sheet metal part 20 according to the prior art is not possible, since such a bracket 30 (typical nominal diameter 6 mm) with its bow 34 on the side edge of the L-shaped sheet metal part 20 and thus the opening 28 of the horizontally extending longitudinal recess 22 cannot be reached and cannot be introduced into it. It is imperative to use a longer bracket 30, which in its end position then has an undesirable, significantly greater inclination and cannot be installed when the upper longitudinal reinforcement Bo, Boo is implemented with reinforcement mats.

In situation III, a bar of the upper reinforcement layer Bo is located exactly vertically above the fastening area BF of the angled longitudinal recess 23. Fig. 4 shows that it is also possible here to press the bow 34 of a bow 30 of minimal bow length h _B into the opening 29 of the angled longitudinal recess 23 by inclining it even more than in situation II (here β = 19 ° in bow position 1), and then to bring the bracket 30 into its end position (bracket position 2). Because of the obstructive rod of the upper reinforcement layer Bo, the bracket 30 cannot be brought into an exactly vertical end position, but instead assumes an angle of inclination a = 2.5 ° in the end position. Because of 1 / cos2.5 ° ≈1.001 Such a bracket 30 would have to have a bracket length that is 0.1% greater _{than the minimum bracket length h B.} As in situation II, however, a bracket 30 of minimal bracket length h _{B can also} be used here, since the slightly larger bracket length can be achieved by the operator putting the shoulders of bracket 30 under tension. In situation III, it is also possible to install a second bracket 30 of minimum bracket length h _B , which, starting from bracket position 1 ', is brought into its end position 2', in which it also assumes an angle of inclination of a = 2.5 ° (but inclined in the opposite direction). In this example, the two brackets 30 in their end positions 2 and 2 'form an opening angle 2α = 5 °.

The objects of the invention are thus achieved in full:
A transverse force reinforcement made of L-shaped sheet metal parts 21 with vertical or almost vertical stirrups 30 of minimum stirrup length h _{B is provided} for a reinforced concrete / prestressed concrete component. The L-shaped sheet metal parts 21 according to the invention with angled longitudinal recess 23 ensure a quick and energy-saving installation of the bracket 30 by pressing the bracket arches 34 into the angled longitudinal recess 23, whereby, due to the small free space R required for pressing in, a manual displacement of reinforcing bars is not is required. This means that the upper longitudinal reinforcement can be implemented using reinforcement mats, which, compared to individual reinforcement bars, can be laid quickly and inexpensively.

The reinforced concrete / prestressed concrete component according to the invention with the transverse force reinforcement according to the invention made of L-shaped sheet metal parts 21 with vertical or almost vertical brackets 30 is particularly intended for use in the area of ceiling supports of flat ceilings. It increases the punching shear strength in the area of such slab props.

The quantitative information in this patent application, in particular regarding the dimensions of the L-shaped sheet metal part 21, is to be regarded as exemplary and not restrictive. The quantitative adaptation to L-shaped sheet metal parts with changed dimensions is easily possible for the specialist. Such adaptations also fall within the scope of the invention as claimed.

Figure legends

Fig. 1 -

Schematic representation of an L-shaped sheet metal part 20 according to the prior art in the installed state and the drawing in of a bracket 30 into the straight longitudinal recess 22 of an L-shaped sheet metal part 20

Fig. 2a -

Schematic representation of a flat component 21 with a recess A.

Fig. 2b -

Schematic representation of an advantageous embodiment of a flat component 21, designed as an L-shaped sheet metal part with angled longitudinal recess 23, in a front view

Fig. 2c -

Specific embodiment of an L-shaped sheet metal part 21 in front, side and plan view

Fig. 3 -

Schematic representation of the pressing of a bracket 30 into an angled longitudinal recess 23 of an L-shaped sheet metal part 21 when there is no obstruction by a bar of the upper reinforcement layer Bo

Fig. 4 -

Schematic representation of the pressing of a bracket 30 into an angled longitudinal recess 23 of an L-shaped sheet metal part 21 when there is an obstruction by a bar of the upper reinforcement layer Bo (for three different positions I, II, III of this bar, for position II comparison with that State of the art)

Note: The curves of the arches 34 are in Fig. 4 not shown due to a simplification of the drawing. The recess 25a is in the Figs. 2b - 4 shown inappropriately wide. It is expediently reduced to approximately half the width by shifting its edge adjacent to the side edge of the flat component 21 into the interior of the flat component 21.

List of reference symbols

1-5 -

Successive positions of a bracket when pulling in or pushing in

20 -

L-shaped sheet metal part according to the prior art

21 -

Flat component with angled longitudinal recess according to the invention, preferably designed as an L-shaped sheet metal part

22 -

straight longitudinal recess, designed as a horizontal slot

23 -

angled longitudinal recess, with fastening area BF and feed channel S.

BF -

Attachment area

Z -

Feed area of a straight longitudinal recess 22

A -

Feed area designed as a recess

S -

Feed channel

24 -

Clip sheet part for locking lug 27

24a -

Clip sheet metal part for locking lug 27a

25, 26 -

Recesses for engaging a clip plate part (with an L-plate according to the state of the art)

25a, 26a-

Recesses for engaging a clip sheet metal part (with an L-shaped sheet metal part according to the invention)

27 -

Latching lug of an L-shaped sheet metal part 20 according to the prior art

27a -

Latching lug of an L-shaped sheet metal part 21 according to the invention

28 -

Opening of the straight longitudinal recess 22 of an L-shaped sheet metal part 20

29 -

Opening of the angled longitudinal recess 23

30 -

hanger

32 -

Temple shoulder

34 -

Bow bow

40 -

Chamfer

50 -

Recesses immediately above the fold 40

Boo -

top layer of reinforcement

Bo -

upper reinforcement layer (immediately below Boo)

Buu

- lowest reinforcement layer

Bu

- lower reinforcement layer (immediately above Buu)

M.

- Center line of the flat component 21

Q

- Shear force reinforcement element, consisting of an L-shaped sheet metal part 20 or 21 and a bracket (or two brackets) 30

R.

- Required free space for pulling in or pressing a bracket into a longitudinal recess 22 or 23

a-f

- Feeding a stirrup sheet 34 at selected feed angles

Formula symbol

HB

- temple length

hB

- minimal temple length

HD

- Difference in height between the opening 29 of the feed channel S and the fastening area BF

LBF

- Length of the fastening area BF of the longitudinal recess 23

LS

- Length of the feed channel S of the longitudinal recess 23

T

- Depth of the longitudinal recess 22 or 23

α

- Angle of inclination of a bracket 30 against the vertical axis (bracket in end position)

β

- Angle of inclination of a bracket30 against the vertical axis (during retraction or depression)

γ

- Angle of inclination of the feed channel S with respect to the fastening area BF

ζ

- Feed angle under which a recess A allows a bow 34 to be fed to the fastening area BF

FZ

- Tensile force when pulling in the bracket 30

FII

- Tangential component of the tensile force F _Z

F⊥

- Normal component of the tensile force F _Z

FD

- Pressure force when pushing in the bracket 30

V.

- Lateral offset between bracket shoulder 32 and bracket bow 34

Claims (13)

1. Flat component (21) for a transverse force reinforcement element (Q), suitable for receiving a stirrup (30), having a lower portion suitable for connection to the lower longitudinal reinforcement of a reinforced/prestressed concrete component, having an upper portion which comprises a fastening region (BF) and a feed region connected thereto, wherein the feed region is in the form of a recess (A) which has a feed angle ζ, measured from a horizontal, of at least 10° to 120°, wherein the recess (A) has a connection to a side edge and/or the upper edge of the flat component (21), wherein the recess (A) is narrowed to form a feed channel (S) in the form of an obliquely upwardly directed longitudinal recess with an opening (29) suitable for feeding a stirrup sheet (34), characterised in that the feed channel (S) has a latching nose (27a) formed by two recesses (25a) and (26a) suitable for receiving a clip sheet member (24a).
2. Flat component (21) according to claim 1, characterised in that the feed angle ζ comprises a range of 10° to 110°, preferably 10° to 80° and 80° to 110°, particularly preferably 40° to 50°.
3. Flat component (21) according to one of claims 1 or 2, characterized in that the feed channel (S) forms an angled longitudinal recess (23) of the flat component (21) by the connection with the fastening region (BF), wherein the feed channel (S) is formed straight or bent.
4. Flat component (21) according to any one of claims 1 to 3, characterized in that the fastening region (BF) has a recess in the direction of the upper edge of the flat component (21).
5. Flat component (21) according to any one of claims 1 to 4, characterised in that its lower portion has a right-angled bend (40).
6. Flat component (21) according to any one of claims 1 to 5, characterized in that the feed channel (S) has an angle of inclination γ selected from the range of at least 10° to 120°.
7. Composant plat (21) selon l'une quelconque des revendications 1 à 6, caractérisé en ce que le canal d'alimentation (S) présente un angle d'inclinaison γ choisi dans la plage de 30° à 60°.
8. Transverse force reinforcement element (Q) for a reinforced/prestressed concrete structural member, comprising a flat structural member (21) according to any one of claims 1 to 7 and at least one stirrup (30) fastened to the flat structural member (21).
9. Transverse force reinforcement element (Q) according to claim 8, characterized in that stirrups (30) are used whose stirrup length H_B, with respect to the minimum stirrup length hB, satisfies the condition h_B<H_B≤1.06·hB, the stirrup lengths H_B=1.06·h_B, H_B=1.05·h_B, H_B=1.04·h_B, H_B=1.03·h_B, H_B=1.02·h_B and H_B=1.01·h_B being preferred.
10. Transverse force reinforcement element (Q) according to claim 8, characterised in that stirrups (30) are used whose stirrup length HB is equal to the minimum stirrup length hB.
11. Reinforced/prestressed concrete structural member with an upper and a lower longitudinal reinforcement, comprising at least one shear force reinforcement element (Q) according to one of the claims 8 to 10 with a flat structural member (21) according to one of the claims 1 to 7 and at least one stirrup (30) connected to the flat structural member (21), wherein the at least one stirrup (30) of the transverse force reinforcement element (Q) has a connection to the upper longitudinal reinforcement of the reinforced/prestressed concrete component and the flat component (21) has a connection to the lower longitudinal reinforcement of the reinforced/prestressed concrete component.
12. Reinforced/prestressed concrete component according to claim 11, characterised in that the upper longitudinal reinforcement is designed as a reinforcement mat.
13. Use of the reinforced/prestressed concrete component according to one of claims 11 or 12 in the area of ceiling supports of flat ceilings.

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