EP3892789B1 - Formwork system - Google Patents

Description

technical field

The present invention relates to a formwork system for concrete construction.

State of the art

Concrete structures such as floor/ceiling slabs are often concreted in several sections. Reasons for this are, for example, the amount of concrete required or a break in work between the pouring of the individual sections. The formwork elements used for this are usually made of steel and have larger dimensions, which leads to a high weight and corresponding difficulties when used on the construction site.

From the EP 507 054 A1 a formwork element is known in which the bars of the latticework forming the formwork girder are arranged on both surfaces of an intermediate metal panel and are welded thereto. The formwork element results in improved anchoring and reinforcement in the concrete and is particularly suitable for shuttering connecting surfaces to which another concrete section is to be connected later.

In the case of large-volume concrete structures and a correspondingly increased concrete pressure, one of the EP 1 132 545 A2 known formwork material can be used. This formwork material consists of a sheet of expanded metal and transverse and longitudinal stiffening elements on both sides of the sheet. The stiffeners are welded together at the crossing points through the panel. It is also possible that from the EP 507 054 A1 to provide known formwork element with additional stiffening elements.

It goes without saying that the formwork elements described must be securely fixed to the reinforcement of the respective concrete structure before the concreting process, since the concrete pressure, which is constantly increasing during the concreting process, must not lead to the formwork element shifting or even falling over. Usually, this fixation happens through a so-called suspension, which consists of an Reinforcement and formwork element consists of welded metal rods. Overall, the erection and fixing of large-format formwork elements is very labor-intensive and therefore cost-intensive.

An approach to solving this problem is offered by DE 20 2008 015 883 U1 , which describes a formwork with back-anchoring device. The back-anchoring device has a tension strut connected both to the formwork wall and to the base. The tension strut is connected to the base and/or to the formwork wall via a hook connection containing a flexible loop element. A disadvantage of this system is the time-consuming attachment of the tension strut, particularly to the lower reinforcement layer. The looping of the rebars with the flexible loop element proves to be quite complex and difficult to carry out in practice.

Another variant of a formwork system with formwork element and suspension is from EP 2 378 030 A2 out. In this case, the tension strut has, at its end adjacent to the reinforcement layer, a loop-hook element with a loop turning area at the end. The loop-hook element is hooked around a reinforcement bar of the reinforcement layer and fixed with a safety bolt inserted between the reinforcement bar and the loop reversal area. However, particularly in the case of cramped spatial conditions with multi-layer lower reinforcement, the attachment of the loop-hook element poses a problem, which sometimes leads to time-consuming assembly work.

There is therefore a continuing need for formwork which can be easily erected and fixed in place and therefore prove to be relatively inexpensive in use.

Presentation of the invention

The object of the invention, as characterized in the claims, is to provide a formwork that can be connected easily and quickly to the reinforcement of the concrete structure and is nevertheless securely fixed to the reinforcement.

According to the invention, this object is achieved by the formwork system according to claim 1 . Further advantageous details, aspects and configurations of the present invention result from the dependent claims, the description, the examples and the drawings.

The formwork system according to the invention for concrete construction comprises a formwork element and at least one back-anchoring system, the formwork element comprising a flat formwork part which, when installed, is oriented essentially perpendicularly to a reinforcement layer. The tie-back system includes a tie-back loop and either a first and second securing pin or a first securing pin and a fixation hook. When installed, the rear anchoring bracket encompasses a reinforcement bar of the reinforcement layer. The back-anchoring bracket has at least: a first reversal area, with the first reversal area being arranged in the vertical direction above the reinforcing bar of the reinforcing layer in the installed state; a second and a sixth reversal area, with the second and the sixth reversal area being arranged in the vertical direction below the reinforcing bar of the reinforcing layer in the installed state. Either the second and the sixth reversal area are in contact with the second safety bolt, with the second safety bolt being inserted in the installed state between the second and sixth reversal area of the back-anchoring bracket and the reinforcement bar of the reinforcement layer and thus securing the back-anchoring bracket in its position, or the second or the sixth reversal area is in contact with the fixing hook, with the fixing hook embracing a reinforcement bar of the reinforcement layer and thus securing the back-anchoring bracket in its position.

The back-anchoring bracket also has at least: a third and a fifth reversal area, with at least a part of the third and a part of the fifth reversal area being arranged in the vertical direction below the rebar of the reinforcement layer in the installed state, and the third and the fifth reversal area being arranged with the first safety bolt are in contact, the first safety bolt being inserted in the installed state between the third and the fifth reversal area of the back-anchoring bracket and the rebar of the reinforcement layer; and a fourth inversion area, wherein in the installed state the fourth inversion area is arranged in the vertical direction above the reinforcing bar of the reinforcing layer and the fourth inversion area is in contact with the reinforcing bar of the reinforcing layer. The formwork element has at least one recess and when installed, the rear anchoring bracket engages at least with its first reversal area in the recess of the formwork element, wherein the rear anchoring bracket comes into operative connection with the formwork element in such a way that the formwork element is securely fixed in its position.

In the context of the present text, the term "encompass" is understood to mean a partial enclosing. For example, if the present text mentions that the rear anchoring bracket encloses a reinforcement bar of the reinforcement layer when installed, then this does not mean that the rear anchoring bracket completely encloses the reinforcement bar like a ring. Rather, the back-anchoring bracket is placed with one of its reversal areas on the reinforcing bar and thus only partially encompasses it.

A “reversal area” is understood to mean a section in which the rear anchor bracket is bent, that is to say changes direction over its course.

For example, the tie-back stirrup of the present invention can be easily manufactured from a steel bar such as black steel bar or rebar. To do this, the steel rod is first bent into a circular ring and the ends are welded together. By squeezing the ring in the plane of the ring, the ring is given an oval shape, as a result of which the first 8.1 and the fourth 8.4 reversal area are formed. This oval ring is bent a second time in a direction perpendicular to the plane of the ring, forming the second 8.2 and sixth 8.6 turnaround area. A third bending process, again perpendicular to the plane of the ring but spaced apart from the plane of the second bending, forms the third 8.3 and the fifth 8.5 reversal area and the back anchor bracket receives its in the figure 2 shown shape.

As will be described in more detail below, both the first and the second safety bolt can be equipped with an eyelet and can be inseparably connected to the rear anchor bracket with the aid of this eyelet. The production of such a rear anchoring bracket with safety bolts attached to it can basically be done in two ways. First, as described above, a rear anchoring bracket can be formed and then the eyelet of the safety bolt or bolts can be formed by welding with the rear anchoring bracket passed through the eyelet. It is also possible to first attach an eyelet to each of the safety bolts and then to form the back-anchoring bracket as described above, with the steel rod used to produce the back-anchoring bracket being guided through the eyelets of the safety bolts. In terms of manufacturing technology, the production of the back-anchoring bracket in a first step and the subsequent welding of the eyelet to the safety bolt with the back-anchoring bracket guided in it is less problematic.

The formwork system according to the invention does not require any suspension, but nevertheless provides a formwork which is extremely securely and permanently secured in its position. The entire structure is very easy to accomplish and requires a significantly reduced amount of work, especially compared to the usual welding processes for fastening a suspension. Attaching the back anchor bracket to the reinforcement layer requires significantly less work and time than welding the suspension to the reinforcement and the formwork element.

In particular, no welding process is required when installing the formwork system according to the invention. In the case of construction sites where all welding is prohibited, the formwork system according to the invention therefore provides a formwork that is easy to handle and inexpensive. In addition, the back-anchoring bracket is a somewhat bulky, easy-to-handle part that can simply be placed on a rebar of the lower reinforcement layer, even when space is limited. Overall, the formwork system can be set up and fixed with comparatively little effort and is therefore relatively inexpensive to use.

At this point it should be mentioned that it is clear to the person skilled in the art that the curvatures of the reversal areas of the back-anchoring bracket are adapted to the dimensioning of the reinforcement. Thus, the larger the diameter of the reinforcing bar on which the rear anchoring bracket is placed, the larger the radius of curvature of the first and fourth reversal areas. The third and the fifth reversal area advantageously have a similar or identical radius of curvature because this makes it easier to insert the safety bolt. There are also advantages if the third and the fifth reversal area are spaced essentially the same distance from the rebar after the fourth reversal area has been placed on the reinforcing bar. This is the case when the rear anchor bracket has a plane of symmetry which intersects the first and fourth reversal area and maps the third and fifth reversal area to one another, as well as the second and sixth reversal area. In this case, too, the safety bolt can be inserted particularly easily between the reinforcing bar and the third and fifth reversal area.

As described in more detail below, the stirrup is attached under tension to the reinforcement in the area of the second and sixth inversion areas. There are two alternatives for this. Either a second safety bolt is used or a fixing hook is provided. When installed, either the second and the sixth reversal area are then in contact with the second safety bolt, the second safety bolt being inserted between the second and sixth reversal area of the back-anchoring bracket and the rebar of the reinforcement layer and thus the Secures back anchor bracket in position. Alternatively, either the second or the sixth reversal area is in contact with the fixing hook, with the fixing hook encompassing a reinforcement bar of the reinforcement layer and thus securing the back-anchoring bracket in its position.

When assembling the formwork system according to the invention, the first step is to place the rear anchor bracket on a rebar of the lower reinforcement layer in such a way that the fourth reversal area rests on the rebar and the third and fifth reversal areas are arranged vertically below the rebar. Then, the first safety bolt is inserted through the gap formed by the reinforcing bar on which the back anchorage bar is laid and the third and fifth inverted portions of the back anchorage bar located below the reinforcing bar in the vertical direction.

Now, in the area of the first reversal area of the rear anchoring bracket, a pressure oriented in the direction of the lower, horizontally arranged reinforcement layer is exerted on the rear anchoring bracket. This pressure is applied with such force until the second and the sixth reversal area are arranged in the vertical direction below the rebar of the reinforcement layer, on which the tie-back stirrup was placed with its fourth reversal area. In this state, the rear anchoring stirrup is fixed under tension to the lower reinforcement layer. As already described, this is done either using a second safety bolt or using a fixing hook. In the case of a second safety bolt, this is inserted between the second and the sixth reversal area of the back anchor bracket and the rebar of the reinforcement layer. Because the tieback bar is under tension, it tries to move up against the previously applied pressure, but this is prevented by the safety pin. Due to this restoring force, the rear anchoring bar exerts an upwardly oriented compressive force on the safety bolt in the area of its second and sixth reversal area, which in turn transfers this compressive force to the reinforcing bar on which the rear anchoring bar was placed. In this case, when installed, the second and the sixth reversal area are in contact with the second safety bolt and the rear anchor bracket is secured in its position.

Alternatively, a fixing hook is hooked into a rebar of the lower reinforcement layer, this rebar being located in the vertical direction below the rebar on which the rear anchoring bracket was placed with its fourth reversal area. Since the back anchor bracket is also under tension in this case, it tries to move upwards against the pressure previously exerted to move, but this is prevented by the fixing hook. Due to this restoring force, the rear anchor bracket exerts an upwardly oriented tensile force on the fixing hook. The fixation hook is located in the area of the second or the sixth reversal area of the back-anchoring bracket, which is why the force is transmitted from the back-anchoring bracket to the fixing hook in this area. The fixing hook, in turn, transfers the tensile force to the rebar into which it is hooked. In this case, when installed, the second or the sixth reversal area is in contact with the fixing hook and the rear anchor bracket is secured in its position.

In this state, the rear anchoring bracket is securely fixed to the reinforcement. In its section lying between the second and the sixth reversal area, the rear anchoring bracket protrudes in the vertical direction upwards beyond the reinforcement layer. This section protruding from the lower reinforcement layer comprises the first reversal area of the rear anchor bracket and is preferably oriented essentially perpendicularly to the reinforcement layer. Other orientations are also conceivable, in which case the recess of the formwork element, which is described in more detail below, is preferably designed such that after the section of the rear anchorage bracket that encompasses the first reversal area of the rear anchorage bracket has been pushed into the recess, the formwork element is aligned essentially perpendicularly to the reinforcement layer . In principle, orientations of the formwork element to the reinforcement layer that deviate from the vertical are also conceivable, but this is known to occur much less frequently in practice.

According to the invention, the formwork element has at least one recess into which the back-anchoring bracket engages at least with its first reversal area when installed. In this case, the back-anchoring bracket comes into operative connection with the formwork element in such a way that the formwork element is securely fixed in its position. The recess provided on the formwork element can, in principle, be configured in any way whatsoever. It only has to fulfill the condition that the rear anchoring bracket can be pushed or plugged into the recess with its section encompassing the first reversal area and thus enters into an operative connection with it, by which the formwork element is securely fixed in its position.

This completes the installation of the formwork system according to the invention. The entire structure does not require any welding. The back anchor bracket can be attached to the lower reinforcement layer in just a few simple steps. Finally, the formwork element needs only from above on the to be clipped onto the stop provided on the back anchor bracket and is immediately securely, firmly and permanently fixed in position.

The back-anchoring bracket is preferably a closed steel wire loop. Steel wire is an inexpensive raw product that is always readily available, which also enables the above-described uncomplicated production of the back-anchoring bracket in its desired shape.

The first and/or the second safety bolt are preferably formed by a reinforcing steel bar. In this case, too, advantages result from the fact that steel wire is an inexpensive raw product that is always readily available and can be processed in a simple manner to produce a suitable safety bolt.

The first and/or the second safety bolt particularly preferably has an eyelet, with the back-anchoring bracket being guided through the eyelet or through the eyelets. In this case, the safety bolt is inseparably connected to the back anchor bracket. After placing the back-anchoring bracket on the rebar, the safety bolt is immediately at hand and can be inserted between the rebar and the third and fifth reversal areas of the back-anchoring bracket located vertically below the rebar. The same applies to the above-described fixation of the back-anchoring bracket under tension by inserting the second safety bolt between the reinforcing bar and the second and sixth reversal areas of the back-anchoring bracket located vertically below the reinforcing bar.

According to a further preferred embodiment, the first and/or the second safety bolt is/are designed as a terminal section of a bracket element. A substantially U-shaped bracket element with a shorter leg forming the safety bolt and a longer leg serving as a handle for the user allows each of the two safety bolts to be placed between the reinforcing bar and those located vertically below the reinforcing bar in a particularly simple manner Reversal areas of the back anchor bracket are inserted.

The fixing hook particularly preferably has an eyelet, with the back-anchoring bracket being guided through the eyelet. In this case, the fixing hook is inseparably connected to the back anchor bracket. When fixing the back anchor bracket under tension, the fixing hook is immediately at hand and can be hooked into a reinforcement bar of the lower reinforcement layer as described.

At this point it should be mentioned that although the formwork system according to the invention is described below in connection with the erection of a floor/ceiling slab, the formwork system can also be used in connection with wall-floor/ceiling joints and wall-wall joints.

According to a preferred embodiment, the flat formwork part has openings. The openings in the flat formwork part are advantageously chosen large enough on the one hand to ensure a durable and permanent connection of the concrete of the two adjacent concreting sections, but on the other hand are not so large that the concrete of the first concreting section can flow through the openings.

Particularly preferably, the flat formwork part consists of a metal grid made up of transverse and longitudinal bars and a sheet of expanded metal connected to the bars of the metal grid, the sheet of expanded metal being arranged between the transverse and longitudinal bars of the metal grid. The transverse bars of the metal grid are preferably welded to the longitudinal bars of the metal grid at their crossing points. Depending on the type of use of the formwork element, the thickness of the transverse and longitudinal bars of the metal grid and the distance between the transverse and longitudinal bars can be optimized. The higher the concrete pressure to be expected on the formwork element, the thicker the individual bars must be dimensioned or the smaller the distance between the transverse and longitudinal bars of the metal grid must be used. The ones from the EP 507 054 A1 known formwork elements combine various favorable properties in this context.

The formwork element preferably comprises at least two longitudinal rods as additional stiffening elements on the rear side of the flat formwork part. The stability and rigidity of the formwork element is increased by the longitudinal rods. As an alternative or in addition to the longitudinal bars, the formwork element preferably comprises a lattice girder fastened to the back of the flat formwork part as a further stiffening element. A lattice girder further increases the stability and rigidity of the formwork element. Such formwork parts and methods for their production are from EP 507 054 A1 known.

According to a particularly preferred embodiment of the present invention, the formwork element has at least two recesses, namely a first one Recess and a second recess, wherein the two recesses are arranged in alignment one above the other in the vertical direction. In the installed state, the back-anchoring bracket engages at least with its first reversal area in the two recesses of the formwork element and is operatively connected to the formwork element in such a way that the formwork element is securely fixed in its position. The stability of the fixing of the formwork element is significantly improved by the insertion of the rear anchoring bracket into two recesses of the formwork element arranged one above the other. The forces acting on the formwork element during the concreting process can be better transferred to the rear anchorage bracket and from there to the reinforcement layer via the enlarged contact surface between the formwork element and rear anchorage bracket.

As already mentioned, the recess provided on the formwork element or the recesses provided on the formwork element can, in principle, have any desired configuration. Only the condition must be met that the rear anchoring bracket can be pushed or plugged into the recess(es) with its section encompassing the first reversal area and thus enters into an operative connection through which the formwork element is securely fixed in its position. A first curved rod, which is fastened to a first transverse rod of the formwork element and runs essentially parallel to the first transverse rod, is preferably provided, with the first recess being formed between the first transverse rod and the first curved rod. Particularly preferably, a second curved rod, which is fastened to a second transverse rod of the formwork element and runs essentially parallel to the second transverse rod, is provided, with the second recess being formed between the second transverse rod and the second curved rod. In the practical implementation, slightly curved reinforcement rods, so-called hat brackets, are welded to the transverse rods of the formwork element in order to realize these embodiments. The section of the back-anchoring bracket encompassing the first reversal area is pushed into the resulting narrow slit between the formwork element and the top-hat bracket, and the formwork element as a whole is pushed onto the back-anchoring bracket.

As already mentioned, several recesses arranged one above the other lead to improved stability of the formwork element. Of course, depending on the dimensions of the concrete structure to be erected and the concrete pressure to be expected, recesses arranged next to one another in the horizontal direction can also be provided on the formwork element. In this case, a corresponding number of back-anchoring stirrups are fixed next to each other on different reinforcement bars of the lower reinforcement layer. With a correspondingly suitable spacing of recesses and back-anchoring brackets, the formwork element can now open several rear anchoring brackets can be attached. The horizontal spacing of the recesses is flexible and decreases as the concrete pressure increases. If necessary, the recesses are formed over the entire length of the formwork element in order to be able to freely position the position of the back anchoring system and to be able to comply with on-site constraint points. This ensures a further improved secure fixing of the formwork element.

If only one recess is provided on the formwork element in the vertical direction, the recess is particularly preferably arranged in the region of the lower edge of the formwork element, ie adjacent to the lower reinforcement layer. In this way, a particularly secure fixing of the formwork element is achieved.

In the case of recesses arranged one above the other in the vertical direction, the second recess is particularly preferably located at a maximum vertical distance of 150 mm from the first recess. In this case, the section of the rear-anchoring bracket, which includes the first reversal area, is pushed into both recesses and thus enters into an operative connection with the formwork element, as a result of which the formwork element is securely fixed in its position.

According to a further, particularly preferred embodiment of the present invention, the rear-anchoring bracket has a seventh and an eighth reversal area. The seventh reversal area is arranged between the second reversal area and the third reversal area, and the eighth reversal area is arranged between the fifth reversal area and the sixth reversal area. When installed, the seventh and eighth reversal area is arranged in the vertical direction above the rebar of the reinforcement layer. Due to these two additional reversal areas, the back-anchoring bracket has a further bend, which means that the back-anchoring bracket can also be installed securely and firmly when the top layer of rebars of the lower reinforcement layer is oriented parallel to the formwork element. In this case, the tie-back stirrup must be fastened in the second layer, seen from above, to rebars running perpendicular to the formwork element.

As explained in more detail below in connection with the figures, the flat formwork part, which is aligned essentially perpendicularly to the reinforcement layer in the installed state, separates a first concrete section from a second concrete section. Particular advantages result if the at least one recess or the at least two recesses of the formwork element are arranged in the second concreting section. The rear-anchoring bracket pushed into the recess(es) with its section encompassing the first reversal area in this case encompasses the formwork part and supports it on its rear side facing away from the first concreting section. The formwork part can thus withstand the pressure exerted by the concrete of the first concreting section even better.

Brief description of the drawings

Fig. 1

einen vertikalen Schnitt durch eine Bodenplatte mit dem erfindungsgemäßen Schalungssystem;

Fig. 2

einen Rückverankerungsbügel mit Sicherungsbolzen und Fixierungshaken;

Fig. 3

eine vergrößerte Darstellung des Bereichs der Befestigung des Rückverankerungsbügels an der Bewehrung;

Fig. 4A

schematisch einen Ausschnitt der unteren Bewehrungslage beim Anbringen des Rückverankerungsbügels unter Spannung durch Ausübung einer Druckkraft auf den Rückverankerungsbügel;

Fig. 4B

eine vergrößerte Darstellung des Bereichs der Befestigung des Fixierungshakens an der Bewehrung;

Fig. 5

einen an der Bewehrung befestigten Rückverankerungsbügel mit einem ersten Sicherungsbolzen und einen in Form eines Bügelelements ausgebildeten zweiten Sicherungsbolzen;

Fig. 6A

eine vergrößerte Darstellung des Bereichs der ersten und der zweiten Ausnehmung des Schalungselements;

Fig. 6B

eine vergrößerte Darstellung des an der Bewehrung befestigten Rückverankerungsbügels mit daran befestigtem Schalungselement bei horizontal orientierter Blickrichtung auf das Schalungselement;

Fig. 7

eine vergrößerte Darstellung des Rückverankerungsbügels mit daran befestigtem Schalungselement bei seitlicher Blickrichtung auf das Schalungselement;

Fig. 8

schematisch eine weitere Ausführungsform eines Rückverankerungsbügels;

Fig. 9

einen vertikalen Schnitt durch eine Bodenplatte mit einer weiteren Ausführungsform des erfindungsgemäßen Schalungssystem.

The invention will be explained in more detail below using exemplary embodiments in connection with the drawings. However, it is expressly pointed out that the invention should not be restricted to the examples given. Show it

1

a vertical section through a base plate with the formwork system according to the invention;

2

a tie-back bracket with safety bolts and fixation hooks;

3

an enlarged view of the area of attachment of the back anchor bracket to the reinforcement;

Figure 4A

schematically shows a section of the lower reinforcement layer when attaching the rear anchor bracket under tension by exerting a compressive force on the rear anchor bracket;

Figure 4B

an enlarged view of the area of attachment of the fixing hook to the reinforcement;

figure 5

a stirrup attached to the reinforcement having a first securing bolt and a second securing bolt in the form of a stirrup member;

Figure 6A

an enlarged view of the area of the first and the second recess of the formwork element;

Figure 6B

an enlarged view of the rear anchor bracket attached to the reinforcement with the formwork element attached to it, with a horizontally oriented viewing direction of the formwork element;

7

an enlarged view of the back-anchoring bracket with the formwork element attached thereto, looking at the formwork element from the side;

8

schematically another embodiment of a back anchor bracket;

9

a vertical section through a base plate with a further embodiment of the formwork system according to the invention.

Ways to carry out the invention

the figure 1 shows a vertical section through a floor slab. Shown are the lower reinforcement layer 6, the upper reinforcement layer 16, a formwork element 1 and a rear anchoring bracket 8. The formwork element 1 comprises a flat formwork part 3 with a front side facing the first concrete section BA1 and a rear side facing the second concrete section BA2. The flat formwork part 3 consists of a metal grid made up of transverse 14 and longitudinal bars 15 and a panel 17 made of expanded metal connected to the bars of the metal grid (see Fig Figure 6B ). For example, structural steel rods can be used as transverse and longitudinal rods, such as are also used for reinforcement mats or the like. The sheet 17 of expanded metal is placed between the transverse 14 and longitudinal 15 bars of the metal mesh. A lattice girder 19 is attached to the back of the flat formwork part 3 as an additional stiffening element.

In the schematic representation of figure 1 the rear anchoring bracket 8 is also shown, which is fastened to the lower reinforcement layer 6 with the aid of a first 5.1 and a second 5.2 safety bolt. Also visible is the section of the rear anchoring bracket 8 running in the vertical direction parallel to the flat formwork part 3, which is inserted into the at least one recess arranged on the rear side of the formwork element 1 facing the second concreting section BA2. The recess of the formwork element 1 is in the figure 1 not shown, but will be explained in more detail below.

the figure 2 shows a back anchoring system 2 comprising a back anchoring bracket 8, a first safety bolt 5.1 and a fixing hook 4. The back anchoring bracket 8, designed in the form of a closed steel wire loop, comprises a first reversal area 8.1, a second reversal area 8.2, a third reversal area 8.3, a fourth reversal area 8.4, a fifth reversal area 8.5 and a sixth reversal area 8.6. The curvatures of the reversal areas 8.1, 8.4 of the rear anchorage bracket are adapted to the dimensioning of the reinforcement such that the distance between the second reversal area 8.2 and the sixth reversal area 8.6 and the distance between the third reversal area 8.3 and the fifth reversal area 8.5 corresponds approximately to the diameter of the reinforcing bar on which , as will be explained in more detail below, the rear anchor bracket 8 is placed. The second 8.2 and the sixth 8.6 reversal area and the third 8.3 and the fifth 8.5 reversal area have identical radii of curvature, which is why the rear anchorage bracket 8 has a plane of symmetry which intersects the first 8.1 and fourth 8.4 reversal area and the second 8.2 and sixth 8.6 reversal area and the third 8.3 and fifth 8.5 reversal area respectively mapped to each other.

The first securing bolt 5.1, formed from a reinforcing steel bar, is equipped with an eyelet 12 (see also figure 3 ), through which the rear anchor bracket 8 is guided. First safety bolt 5.1 and rear anchor bracket 8 are inextricably linked.

The fixing hook 4 is also formed from a reinforcing steel bar and is equipped with an eyelet 13 through which the back-anchoring bracket 8 is guided. Fixation hook 4 and rear anchor bracket 8 are inextricably linked.

In the figure 3 the area of attachment of the rear anchor bracket 8 to the lower reinforcement layer 6 is shown enlarged. The lower layer of reinforcement 6 is shown in the form of four layers of rebars, the individual layers of rebars each consisting of rebars running substantially parallel to one another, but the rebars of successive layers being substantially perpendicular to the rebars of the layer below or above rebars are oriented. The entire reinforcement layer can also be made up of reinforcement mats in the usual way.

The rear anchoring bracket 8 is first placed on the rebar 22 of the lower reinforcement layer 6 in such a way that the fourth 8.4 reversal area rests on the rebar 22 and the third 8.3 and fifth 8.5 reversal area are arranged vertically below the reinforcing bar 22.

The curvature of the fourth reversal area 8.4 of the rear anchor bracket 8 is adapted to the dimensioning of the reinforcement. After placing the rear anchor bracket 8 on the rebar 22, the first safety bolt is 5.1 through the gap between the rebar 22, on which the Back anchor bracket 8 is placed, and the third 8.3 and fifth 8.5 reversal area of the back anchor bracket 8, which are located in the vertical direction below the reinforcing bar 22, form plugged. The situation with the first safety bolt 5.1 inserted is in the Figure 4A shown.

the Figure 4A shows the installation step in which, in the area of the first reversal area 8.1 of the rear anchoring bracket 8, a pressure D oriented in the direction of the lower, horizontally arranged reinforcement layer 6 is exerted on the rear anchoring bracket 8. This pressure D is exerted and with such a force until the second 8.2 and the sixth 8.6 reversal area are arranged in the vertical direction below the reinforcement bar 22 of the reinforcement layer 6 . The rear anchoring bracket 8 was placed on the reinforcing bar 22 with its fourth reversal area 8.4. In this state, the rear anchor bracket 8 is fixed to the lower reinforcement layer 6 under tension.

This is done as in Figure 4B shown, with the help of the fixing hook 4. This fixing hook 4 is hooked into the rebar 24 of the lower reinforcement layer 6, with the rebar 24 being located in the vertical direction below the rebar 22 on which the rear anchoring bracket 8 was placed with its fourth reversal area 8.4. Since the rear anchor bracket 8 is under tension, it tries to move upwards against the pressure previously exerted, but this is prevented by the fixing hook 4 . Due to this restoring force, the rear anchor bracket 8 exerts an upwardly oriented tensile force on the fixing hook 4 . The fixing hook 4 is located in the area of the sixth reversal area 8.6 of the rear anchoring bracket 8, which is why the force is transmitted from the rear anchoring bracket 8 to the fixing hook 4 in this area. The fixing hook 4 in turn transfers the tensile force to the reinforcing bar 24, in which it is hooked. The sixth reversal area 8.6 is thus in contact with the fixing hook 4 and the rear anchor bracket 8 is secured in its position.

figure 5 shows an installation situation analogous to Figure 4B . The rear anchor bracket 8 is fixed to the lower reinforcement layer 6 under tension. The rear anchoring bracket 8 was placed on the reinforcing bar 22 with its fourth reversal area 8.4. The first safety bolt 5.1 was then inserted through the space formed by the reinforcing bar 22 and the third 8.3 and fifth 8.5 reversal area of the rear anchor bracket 8. As already described, in the area of the first reversal area 8.1 of the rear anchoring bracket 8, a pressure oriented in the direction of the lower, horizontally arranged reinforcement layer 6 was exerted on the rear anchoring bracket 8. To secure the back anchor bracket 8 under In this case, a second safety bolt 5.2 is used to tension the lower reinforcement layer 6. The firm, safe and permanent anchoring of the rear anchor bracket 8 to the lower reinforcement layer 6 can be seen immediately.

The second securing bolt 5.2 is designed as the terminal section of a bracket element 18. The essentially U-shaped bracket element 18 has a shorter leg forming the second safety bolt 5.2 and a longer leg serving as a handle for the user. The user can grip the longer leg of the stirrup element 18 and insert the shorter leg between the reinforcing bar 22, on which the rear anchoring stirrup 8 is placed, and the second 8.2 and sixth 8.6 reversal area of the rear anchoring stirrup 8 located vertically below the reinforcing bar 22. The shorter leg now forms the second safety bolt 5.2 and assumes its function.

the Figure 6A shows an enlarged representation of the formwork element 1. The formwork element 1 has a flat formwork part 3, which consists of a metal grid made up of transverse 14 and longitudinal bars 15 and a panel 17 made of expanded metal connected to the bars of the metal grid (see Figure 6B ). The sheet 17 of expanded metal is placed between the transverse 14 and longitudinal 15 bars of the metal mesh.

In the Figure 6A a first curved rod 23.1, which is fastened to a first transverse rod 14.1 of the formwork element 1 and runs essentially parallel to the first transverse rod 14.1, can be seen. The first recess 20 is formed between the first transverse bar 14.1 and the first curved bar 23.1. The bar 23.1 is a reinforcing bar in the form of a hat bracket, which was welded to the crossbar 14.1 of the formwork element 1. In the vertical direction above the first curved rod 23.1, there is a second curved rod 23.2, which is fastened to the second transverse rod 14.2 of the formwork element 1 and runs essentially parallel to the second transverse rod 14.2. The second recess 21 is formed between the second transverse bar 14.2 and the second curved bar 23.2. The second bar 23.2 is also a reinforcing bar in the form of a hat bracket, which was welded to the transverse bar 14.2 of the formwork element 1.

Figure 6B shows an enlarged view of the rear anchor bracket 8 fastened to the reinforcement layer 6 with the formwork element 1 fastened to it. Clearly recognizable is the rear anchor bracket 8, its fourth reversal area 8.4 resting on the reinforcing bar 22, and the first safety bolt 5.1. In the area of the flat formwork part 3 is the first reversal area 8.1, in the vertical direction recognizable section of the rear anchor bracket 8 protruding upwards over the reinforcement layer 6 . This section of the rear anchor bracket 8, which protrudes upwards beyond the reinforcement layer 6, is pushed into the two narrow slots between the first transverse bar 14.1 and the first curved bar 23.1 or between the second transverse bar 14.2 and the second curved bar 23.2. The entire formwork element 1 is thus placed on the rear anchor bracket 8 and is immediately fixed securely, firmly and permanently in its position.

the figure 7 also shows an enlarged representation of the back-anchoring bracket 8 with the formwork element 1 fastened to it. The viewing direction is oriented laterally in the direction of the rear side of the formwork element 1 facing the second concreting section BA2. In the area of the flat formwork part 3, the section of the rear anchor bracket 8, which encompasses the first reversal area 8.1 and protrudes in the vertical direction upwards over the reinforcement layer 6, can be seen. This section of the rear anchor bracket 8, which protrudes upwards beyond the reinforcement layer 6, is pushed into the two narrow slots between the first transverse bar 14.1 and the first curved bar 23.1 or between the second transverse bar 14.2 and the second curved bar 23.2. The back-anchoring bracket 8 inserted with its section encompassing the first reversal area 8.1 into the recesses 20, 21 encompasses the formwork part 3 and supports it on its rear side facing away from the first concreting section BA1. The entire formwork element 1 is thus placed on the rear anchoring bracket 8 and is immediately securely, firmly and permanently fixed in its position, with the formwork element 1 due to the recesses 20, 21 arranged in the second concreting section BA2 and the rear anchoring bracket 8 inserted therein can withstand the pressure exerted during the first concreting section BA1 even better.

Finally shows the figure 8 another embodiment of a back-anchoring bracket 8, which is designed in the form of a closed steel wire loop and a first reversal area 8.1, a second reversal area 8.2, a third reversal area 8.3, a fourth reversal area 8.4, a fifth reversal area 8.5, a sixth reversal area 8.6, a seventh reversal area 8.7 and an eighth reversal area 8.8. In contrast to the related to the Figures 1 to 7 In addition to the rear anchoring bracket discussed, the rear anchoring bracket shown here also has a seventh 8.7 and an eighth 8.8 reversal area. The seventh reversal area 8.7 is arranged between the second reversal area 8.2 and the third reversal area 8.3 and the eighth reversal area 8.8 is arranged between the fifth reversal area 8.5 and the sixth reversal area 8.6.

In the exemplary embodiment shown here, too, the curvatures of the reversal areas 8.1, 8.4 of the rear anchoring bracket 8 are adapted to the dimensioning of the reinforcement such that the distance between the second reversal area 8.2 and the sixth reversal area 8.6 and the distance between the third reversal area 8.3 and the fifth reversal area 8.5 and also the The distance between the seventh 8.7 and eighth 8.8 reversal area corresponds approximately to the diameter of the reinforcing bar 22 on which the rear anchoring bracket 8 is placed. The second 8.2 and the sixth 8.6 reversal area as well as the third 8.3 and the fifth 8.5 reversal area and also the seventh 8.7 and the eighth 8.8 reversal area have identical radii of curvature, which is why the rear anchor bracket 8 has a plane of symmetry which intersects the first 8.1 and fourth 8.4 reversal area and the second 8.2 and sixth 8.6 reversal area as well as the third 8.3 and fifth 8.5 reversal area and also the seventh 8.7 and eighth 8.8 reversal area each on one another.

Based on figure 9 it becomes clear that the two additional reversal areas 8.7, 8.8, due to which the rear anchoring bracket 8 has a further bend, mean that the rear anchoring bracket 8 can also be installed securely and firmly when the top layer 6.1 of rebars of the lower reinforcement layer 6 is parallel to the Formwork element 1 is oriented. In this case, the back-anchoring bracket 8 must be fastened in the second layer 6.2, seen from above, to reinforcing rods which run perpendicularly to the formwork element 1. It can also be clearly seen that when installed, the seventh 8.7 and the eighth 8.8 reversal area are in the vertical direction above the reinforcing bar 22 of the reinforcement layer.

Reference List

BA 1

first concreting section

BA 2

second concreting section

1

formwork element

2

back anchor system

3

formwork part

4

fixing hook

5.1

first safety bolt

5.2

second safety bolt

6

lower reinforcement layer

6.1

top layer of rebars of the lower reinforcement layer 6

6.2

Seen from above, second layer of rebars of the lower reinforcement layer 6

8th

rear anchor bracket

8.1

first reversal area of the back anchor bar

8.2

second inversion area of the rear anchor bracket

8.3

third inversion area of the back anchor bracket

8.4

fourth inversion area of the back anchor bracket

8.5

fifth inversion area of the back anchor bar

8.6

sixth inversion area of the back anchor bracket

8.7

seventh inversion area of the rear anchor bracket

8.8

eighth inversion area of the rear anchor bracket

12

eyelet of the safety bolt

13

Eyelet of the fixing hook

14

crossbar

14.1

first crossbar

14.2

second crossbar

15

longitudinal bar

16

upper reinforcement layer

17

expanded metal panel

18

bracket element

19

lattice girder

20

first recess

21

second recess

22

rebar

23.1

first curved rod

23.2

second curved rod

24

rebar

D

Print

Claims (12)

1. A formwork system for concrete construction, comprising

   - a formwork element (1), wherein the formwork element (1) comprises a flat formwork part (3) which is oriented substantially perpendicular to a reinforcement layer (6) when in the installed state, and

   - at least one bracing system (2), wherein the bracing system (2) comprises

   - a bracing bracket (8) and

   - a first securing bolt (5.1) and a second securing bolt (5.2), or a first securing bolt (5.1) and a fixing hook (4),

   wherein the bracing bracket (8) encompasses a reinforcement rod (22) of the reinforcement layer (6) when in the installed state,

   wherein the bracing bracket (8) at least comprises

   - a first return region (8.1), wherein the first return region (8.1) is situated above the reinforcement rod (22) of the reinforcement layer (6) in the vertical direction when in the installed state,

   - a second return region (8.2) and a sixth return region (8.6), wherein the second return region (8.2) and the sixth return region (8.6) are situated below the reinforcement rod (22) of the reinforcement layer (6) in the vertical direction when in the installed state, and

   - the second return region (8.2) and the sixth return region (8.6) are in contact with the second securing bolt (5.2), wherein the second securing bolt (5.2) is present inserted between the second return region (8.2) and the sixth return region (8.6) of the bracing bracket (8) and the reinforcement rod (22) of the reinforcement layer (6) when in the installed state and thus secures the bracing bracket (8) in its position,
   or

   - the second return region (8.2) or the sixth return region (8.6) is in contact with the fixing hook (4), wherein the fixing hook (4) encompasses a reinforcement rod (24) of the reinforcement layer (6) and thus secures the bracing bracket (8) in its position,

   - a third return region (8.3) and a fifth return region (8.5), wherein at least a part of the third return region (8.3) and a part of the fifth return region (8.5) are situated below the reinforcement rod (22) of the reinforcement layer (6) in the vertical direction when in the installed state, and the third return region (8.3) and the fifth return region (8.5) are in contact with the first securing bolt (5.1), wherein the first securing bolt (5.1) is present inserted between the third return region (8.3) and the fifth return region (8.5) of the bracing bracket (8) and the reinforcement rod (22) of the reinforcement layer (6) when in the installed state,

   - a fourth return region (8.4), wherein the fourth return region (8.4) is situated above the reinforcement rod (22) of the reinforcement layer (6) in the vertical direction when in the installed state, and the fourth return region (8.4) is in contact with the reinforcement rod (22) of the reinforcement layer (6),

   wherein the formwork element (1) comprises at least one recess (20), and the bracing bracket (8) engages in the recess (20) in the formwork element (1) at least with its first return region (8.1) when in the installed state, and the bracing bracket (8) comes into operative connection with the formwork element (1) such that the formwork element (1) is fixed securely in its position.
2. Formwork system according to claim 1, characterised in that the bracing bracket (8) is a closed steel wire loop.
3. Formwork system according to either of claims 1 or 2, characterised in that the first securing bolt (5.1) and/or the second securing bolt (5.2) comprises an eyelet (12), wherein the bracing bracket (8) is present guided through the eyelet (12).
4. Formwork system according to either of claims 1 or 2, characterised in that the first securing bolt (5.1) and/or the second securing bolt (5.2) is designed as an end section of a bracket element (18).
5. Formwork system according to any one of the preceding claims, characterised in that the fixing hook (4) comprises an eyelet (13), wherein the bracing bracket (8) is present guided through the eyelet (13).
6. Formwork system according to any one of the preceding claims, characterised in that the flat formwork part (3) consists of a metal grating constructed from transverse rods (14) and longitudinal rods (15) and a panel (17) of expanded metal connected to the rods of the metal grating, wherein the panel (17) of expanded metal is situated between the transverse rods (14) and the longitudinal rods (15) of the metal grating.
7. Formwork system according to any one of the preceding claims, characterised in that the formwork element (1) comprises longitudinal rods fastened to the rear of the flat formwork part (3) and/or a grating support (19) fastened to the rear of the flat formwork part (3) as an additional stiffening element.
8. Formwork system according to any one of the preceding claims, characterised in that the formwork element (1) comprises at least two recesses (20, 21), namely a first recess (20) and a second recess (21), wherein the two recesses (20, 21) are situated aligned one above the other in the vertical direction, and the bracing bracket (8) engages in the two recesses (20, 21) in the formwork element (1) at least with its first return region (8.1) when in the installed state, and the bracing bracket (8) comes into operative connection with the formwork element (1) such that the formwork element (1) is fixed securely in its position.
9. Formwork system according to any one of claims 6 to 8, characterised in that a first curved rod (23.1) is provided, which is fastened to a first transverse rod (14.1) and runs substantially parallel to the first transverse rod (14.1), wherein the first recess (20) is formed between the first transverse rod (14.1) and the first curved rod (23.1).
10. Formwork system according to claim 9, characterised in that a second curved rod (23.2) is provided, which is fastened to a second transverse rod (14.2) and runs substantially parallel to the second transverse rod (14.2), wherein the second recess (21) is formed between the second transverse rod (14.2) and the second curved rod (23.2).
11. Formwork system according to any one of the preceding claims, characterised in that the bracing bracket (8) comprises a seventh return region (8.7) and an eighth return region (8.8), wherein the seventh return region (8.7) is situated between the second return region (8.2) and the third return region (8.3), wherein the eighth return region (8.8) is situated between the fifth return region (8.5) and the sixth return region (8.6), wherein the seventh return region (8.7) and the eighth return region (8.8) are situated above the reinforcement rod (22) of the reinforcement layer (6) in the vertical direction when in the installed state.
12. Formwork system according to any one of the preceding claims, characterised in that the flat formwork part (3), which is oriented substantially perpendicular to the reinforcement layer (6) when in the installed state, separates a first concreting section (BA1) from a second concreting section (BA2), wherein the at least one recess (20) or the at least two recesses (20, 21) in the formwork element (1) are situated in the second concreting section (BA2).

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