EP2241699A2 - Anchor casing for anchoring pre-tensioned reinforcement elements - Google Patents

Abstract

The anchor sleeve (1) comprises a tensioning device, which prestresses the braid (9) or the reinforcement element opposite to the anchor sleeve and a cast anchor sleeve, in which the tensioning device is arranged. A cast concrete body is provided, which absorbs the force introduced by the braids or the reinforcement element on the cast anchor sleeve, where a helical reinforcement ties the concrete cylinder.

Description

The invention relates to an anchor sleeve for the anchoring of prestressed reinforcing elements according to the preamble of claim 1.

In the context of the present invention, the term "prestressed reinforcing elements" is understood to mean, in particular, rope strands. Such rope strands can be designed either as a mono-strand or as a multiple strand.

Likewise, the term "prestressed reinforcing element" is also understood to mean a smooth steel cable or a steel rod which has a smooth or corrugated surface.

In the reinforcement of thin-walled, wide-tensioned components, it is important to work as space-saving as possible. So far, one has used for reinforcement of concrete, wide-tensioned components so-called anchor plates, which were each frontally arranged on the component to be reinforced and between them a reinforcing element, for. B. wore a multiple steel strand.

Disadvantage of this arrangement is that the anchor plates are relatively bulky, need to be specially mounted and can be difficult to integrate in the composite of exciting component.

The bias of a thin plate with z. B. a thickness of 8 cm can not be accomplished with the known anchor plates.

For thin-walled, wide-tensioned components, a preload is often required. In precast plants, this can usually be implemented with a pre-stress with a composite (prestressed bed prestressing). However, this requires a tension track. A web production makes a flexible production impossible, because the elements lined up nearly all are made the same have to. A flexible production in the precast plants is nowadays carried out with circulation systems on individual switch tables on which individual elements can be produced. Switching up to 16.0 m in length and a width of up to 4.50 m also make it possible to produce large-format elements. Especially for such dimensions is a bias useful and logical. A fitted bed for circulating pallets is very expensive and, moreover, difficult to realize due to geometrical boundary conditions:

The invention is therefore based on the object with thin-walled wide-spanned components to create a very small-sized anchoring element for the prestressing of reinforcing elements.

To solve the problem, the invention is characterized by the technical teaching of claim 1.

An essential feature of the invention is that an anchor sleeve is proposed, which consists essentially of three parts, namely a clamping device which is able to bias the strand against the anchor sleeve, also a Gussankerhülse in which the clamping device is arranged and further from a Vergussbetonkörper which receives the introduced from the tensioning wire on the tensioning device on the Gussankerhülse force and forwards in the axial direction and radial direction of the Vergussbetonkörper at least partially surrounding Umhüllungskörper.

An anchor sleeve thus created from the parts clamping device, cast anchor sleeve and Vergussbetonkörper and wrapping body is now ideally created to initiate very high reinforcement forces on the surrounding concrete, in which the novel anchor sleeve is embedded.

The field of application of the novel anchoring is thus the fixation of monostrand tendons.

Adapted to components with slim dimensions, the compact anchoring element allows use in thin panels, parapet supports or ribbed panels.

The novel anchoring sleeve is based on the anchoring of conventional tensioning strands in the tensioning bed. The tension in the strand is transmitted to the concrete element via the bonding behavior between the surface of the strand and the surrounding concrete. The novel designed anchor sleeve absorbs the clamping force of the strand in the smallest space within the cylinder cross-section and gives the absorbed force on the lateral surface of the surrounding concrete on. The anchor sleeve is thus characterized by the two functions to absorb the tension, to distribute along the length of the sleeve and pass over the surface of the sleeve via composite behavior to the environment of the component to be biased. The dimension of the anchor sleeve in cross section is designed to be as slim as possible in order to take into account the small space conditions in the components to be prestressed. The absolute length of the sleeve makes it possible to influence the bonding behavior.

Components of anchor sleeve:

The anchor sleeve consists of several components. A casting with the coordinated dimensions for the central implementation of the strand cross-section and for the wedge to be used forms the beginning of the anchor sleeve. This is followed by a cylinder of high-quality concrete. This concrete cylinder encloses the cast sleeve and forms the extension following the cast body. The resulting cylinder is enclosed by a helical reinforcement. The helical reinforcement absorbs the transverse forces in the cast body and surrounds the concrete cylinder so that it is able to absorb very high concrete compressive stresses.

The introduced in the cast body force is delivered to the part via the side ribs to the coil, and the rest is added to the head side of the adjoining concrete cylinder. The spiral reinforcement increases the Recordable pressure capacity of the concrete significantly at the same time ductile deformation behavior. These experiences could be gained from the tests with the load registration on a helically reinforced concrete dowelling of steel sheets with steel, prestressed concrete components.

The concentrated load transfer from the head of the casting sleeve to the concrete cylinder is taken up by the spiral-reinforced concrete cylinder and then released via the surface of the cylinder to the environment. The helical reinforcement is used to lashing the concrete cylinder but also as a "toothed" surface for the targeted transfer of force from the anchor sleeve to the surrounding concrete of conventional grade.

• Gusskörper mit Innengeometrie für die Aufnahme der Keilverankerung
• Gusskörper mit anschließendem und umschließendem Betonzylinder
• Wendelbewehrung für den Betonzylinder

Specifically, the attached pictures show the components of the anchor sleeve:

• Cast body with internal geometry for receiving the wedge anchorage
• Cast body with adjoining and enclosing concrete cylinder
• Spiral reinforcement for the concrete cylinder

Cast body and concrete cylinder centered a central opening for the implementation of the strand, which is anchored via a wedge anchorage in the cast body.

In an overview drawing, the entire anchor body is shown with the associated strand.

applications:

As mentioned above, the slender anchor sleeve serves to be used in thin-walled components. These include thin wide-stretched prefabricated panel elements. But also plates with rising ribs, which are used with an upper shell as a sandwich cover. When arranging a plurality of anchor sleeves within a scheme, it is advisable to use a sheet as Abschalung, are provided in the holes for the anchor sleeves. Such a variety of anchor sleeves in be arranged according to a distance to a bundle. Two drawings with the applications described above illustrate the scope.

The invention uses several embodiments as a cladding body for the encapsulation of the Vergussbetonkörpers. In a first embodiment it is provided that a helix is used as the sheathing body, which preferably consists of a round steel.

In other embodiments, it is provided that the round steel of the helix is replaced by other profile shapes, such. B. a spherical shape, an oval shape or a wedge shape.

Important in the case of the wrapping body according to the invention is that the forces introduced by the cast anchor sleeve onto the casting concrete body do not lead to the destruction of the casting concrete body because, according to the invention, it is enveloped by a wrapping body arranged on the circumference.

Instead of the choice of a helix as the sheathing body, it is also possible to use a tube provided with a plurality of slots, which is preferably materially connected in one piece to a multiplicity of discs which attach to the tube sheath and which are directed radially outward.

• Durchmesser der Umschnürung d_c
• Durchmesser der Wendelbewehrung ∅_w
• Ganghöhe der Wendelbewehrung S_w
• Fließspannung der Wendelbewehrung fy

The influence of a looping with a helical reinforcement on the compressive strength and the extensibility can be computationally detected and is shown in FIG. The following influencing parameters determine the increase in strength and associated elongation:

• Diameter of the strap d _c
• Diameter of spiral reinforcement ∅ _w
• Pitch of helix reinforcement S _w
• Yield stress of helical reinforcement fy

The following influence is noticeable. As the yield stress of the helical reinforcement increases, the increase in strength and elongation for the concrete increases. The smaller the dimensions of the strapped area, the more prominent the increase in material properties. With decreasing pitch increases the compressive strength and associated elasticity. With the diameter of the helical reinforcement also increase the material properties.

• Betondruckfestigkeit Ausgangsbeton fc = 30.0 N/mm2
• Dehnung bei Erreichen dieser Druckfestigkeit eo = 2.0 0/00
• Stahlfestigkeit fy = 500 N/mm2
• Durchmesser des umschnürten Bereichs 0 = 60 mm

The following input values were processed in the diagram of FIG.

• Concrete compressive strength starting concrete fc = 30.0 N / mm2
• Elongation on reaching this compressive strength eo = 2.0 0/00
• Steel strength fy = 500 N / mm2
• Diameter of the strapped area 0 = 60 mm

The results are shown in the increase of concrete compressive strength for different helix diameters ∅w = 0, 2, 4, 6 mm (o - as reference without helix). The pitch was varied at intervals of 25 mm, starting at 25, 50, 75, 100 mm. It can be seen that the concrete compressive strength ranged from an initial value of f _co = 30 N / mm 2 at a helix diameter of ∅w = 6 mm and a pitch of sw = 25 mm to the value of f _c1 = 105 N / mm 2 (factor 3.5). can be increased. The values for helix diameter and helical pitch can be implemented in the practical version.

Furthermore, the shows Figure B the expansion increase of the constricted concrete, if according to the invention a coil 12 between teeth 9, 10 is installed.

The associated strains in the constricted concrete are also massively increased, but to a degree which is even greater than the strength. For the aforementioned parameters, in the diagram below in Figure B given the respective elongation the associated elongation.

Analogous to the increase in concrete compressive strength, for a helix diameter of ∅w = 6 mm and an associated pitch of 25 mm, an increase in the expansion of 2.0 o / oo for the starting concrete to 27.0 o / oo (factor 13.5) is to be expected.

This increase helps, in particular with the high concrete strength, also to ensure a similar elongation and thus to enable a ductile behavior. Thus, this technique differs from the use of high strength concrete in conjunction with concrete dowels with the use of helical reinforcement.

Based on the previous determination of the concrete compressive strengths, the resistance of the concrete can now be predicted when using concrete anchors. The results of the tests also show that a further increase in concrete resistance through the use of S500 steel coils and a helix diameter of 6 mm is still possible compared to the present results. This will probably be the steel of the failure mechanism in the future.

The possible large strains in the case of reinforced concrete can also be found in the experiments, as documented by the permanent large deformations from the steel teeth.

The subject of the present invention results not only from the subject matter of the individual claims, but also from the combination of the individual claims with each other.

All information and features disclosed in the documents, including the abstract, in particular the spatial design shown in the drawings, are claimed to be essential to the invention insofar as they are novel individually or in combination with respect to the prior art.

In the following, the invention will be explained in more detail with reference to drawings illustrating several execution paths. Here are from the drawings and their description further features essential to the invention and advantages of the invention.

Figur 1:

perspektivische Ansicht auf eine vorgespannte Betonplatte mit erfindungsgemäßen Ankerhülsen

Figur 2:

eine gegenüber Figur 1 abgewandelte Ausführungsform mit vorgespannten Plattenbalken

Figur 3:

die Seitenansicht der Ankerhülse

Figur 4:

Schnitt gemäß der Linie A-A in Figur 3

Figur 5:

Schnitt gemäß der Linie V-V in Figur 4

Figur 6:

eine gegenüber Figur 5 abgewandelte Ausführungsform

Figur 7:

die Ankerhülse in perspektivischer Darstellung

Figur 8:

ein abgewandeltes Ausführungsbeispiel eines Umhüllungskörpers als Ersatz für die Wendel

Figur 9:

die perspektivische Darstellung des Vergussbetonkörpers mit Gussankerhülse und Wendel

Figuren 10 und 11:

perspektivische Ansicht der Gussankerhülse

Figur 12:

perspektivische Ansicht des Vergussbetonkörpers bei eingesetzter Gussankerhülse

Figur 13:

der Vergussbetonkörper in Seitenansicht

Figur 14:

eine erste Ausführungsform eines Wendeldrahtes

Figur 15:

eine zweite Ausführungsform eines Wendeldrahtes

Figur 16:

eine dritte Ausführungsform eines Wendeldrahtes

Show it:

FIG. 1:

Perspective view of a prestressed concrete slab with anchor sleeves according to the invention

FIG. 2:

one opposite FIG. 1 modified embodiment with prestressed plate beams

FIG. 3:

the side view of the anchor sleeve

FIG. 4:

Section along the line AA in FIG. 3

FIG. 5:

Section according to the line VV in FIG. 4

FIG. 6:

one opposite FIG. 5 modified embodiment

FIG. 7:

the anchor sleeve in perspective view

FIG. 8:

a modified embodiment of a wrapping body as a replacement for the helix

FIG. 9:

the perspective view of Vergussbetonkörpers with cast anchor sleeve and coil

FIGS. 10 and 11:

perspective view of the cast anchor sleeve

FIG. 12:

Perspective view of Vergussbetonkörpers with inserted Gussankerhülse

FIG. 13:

the Vergussbetonkörper in side view

FIG. 14:

a first embodiment of a helical wire

FIG. 15:

a second embodiment of a helical wire

FIG. 16:

a third embodiment of a helical wire

In FIG. 1 a plurality of anchoring sleeves 1 according to the invention is shown in its embedding state in a prestressed concrete 11, which is part of a concrete slab 2.

The concrete slab 2 is preferably formed as a precast slab and may have a width of 3 to 4 m and a length of up to 16 m. It is important that they can have a minimum thickness thanks to the small-sized anchor sleeves 1, z. B. a thickness of 8 cm.

It can be seen that at the front of the concrete slab 2, the end face 3 of the Gussankerhülse 4 looks out, and in the interior of the Gussankerhülse a triple-segmented clamping wedge 6 is installed, which accomplishes the clamping device 35 for applying the bias on the strand 9.

Furthermore, it can be seen that on the outer circumference of the anchor sleeve 1, a helix 7 is provided as a wrapping body 26.

The FIG. 2 shows as a modified embodiment, the bias of tiled beams, which are formed as ribs 18, wherein these ribs 18 are in turn biased by a plurality of mutually parallel spaced armature sleeves 1.

Such ribs 18 can also be applied to a concrete slab 2 to be pretensioned.

The FIGS. 3 and 4 show the more detailed construction of a preferred embodiment of the anchor sleeve. 1

On the left side, a cast anchor sleeve 4 is arranged as a tensioning device 35, the exact structure of which can be taken from the drawing figures 10 and 11.

In the interior of the Gussankerhülse a clamping device 35 is arranged, which consists of a triple-segmented clamping wedge 6, so that these three clamping wedges in their Mittenausnehmung record the exciting strand 9.

Thus, the clamping forces of the force introduction surface 33 (lower end face of the Gussankerhülse 4) in the direction of arrow 15 in a form-fitting to the Gussankerhülse 4 subsequent Vergussbetonkörper 5 are introduced.

This Vergussbetonkörper 5 is poured into the interior of a wrapping body 26 and thus partially surrounds the Gussankerhülse 4 and also laid in the interior strand 9th

After curing of Vergussbetonkörpers 5 thus the clamping forces of the Gussankerhülse 4 are introduced in the direction of arrow 15 in the axial direction in the Vergussbetonkörper 5 and partially deflected radially upward, z. B. in the direction of arrow 32 in the direction of the lateral surface of the potting.

It has now been found according to the invention that the strength of a Vergussbetonkörpers 5 can be significantly increased if it is wrapped on its outer periphery with a wrapping body 26.

In the illustrated embodiment, this wrapping body 26 is formed as a helix 7, which forms a plurality of spiral turns, which are embedded in semi-open helical grooves 13 on the periphery of Vergussbetonkörpers 5.

To produce such an arrangement, it is provided that the helix is first surrounded by a shell-shaped formwork, in which also the cast anchor sleeve 4 is included.

From the rear end side of the thus prepared formwork is then filled with Vergussbetonkörper 5 so that it fills the entire interior of the coil 7 and also partially surrounds the Gussankerhülse 4.

The helix 7 then protrudes with its helical surface 14 away from the surface of the grouting concrete body 5 and is therefore higher than the outer circumference of the grouting concrete body.

Thus, the Vergussbetonkörper 5 has undergone a reinforcement by the wrapping body 26, which has a grooved surface thanks to the surface side arranged helix 7.

The introduced into it forces in the direction of arrow 15, 32 are thus low in the direction of arrow 17 to the outside in the surrounding surrounding the helix 7 vorzuspannenden concrete 11.

Part of the introduction takes place over the surface of Vergussbetonkörpers 5, which sees through between the spiral bonds and on the other hand directly over the helical surfaces 14 itself.

Incidentally, a cladding tube 8 is cast into the rear end face of the grouting concrete body 5 and held in the material of the grouting concrete body 5, in the interior of which the stranded wire 9 is passed.

This shows the FIG. 5 , where it can be seen that in the interior of the cladding tube 8, a grease layer 10 is arranged, which surrounds the strand 9 at the periphery. The grease layer 10 is a corrosion protection for the strand 9 in this area and allows the strand in the clamping direction (axial direction) can be drawn into the clamping device 35.

It goes without saying that the clamping device 35 shown here can not only consist of the cast anchor sleeve 4 with segmented clamping wedges 6. In another embodiment, it is provided that instead a spindle clamping device or an eccentric clamping device is provided. It is only important that with respect to the cast anchor sleeve 4 a sufficient tensile stress is applied in order to be able to initiate this tensile stress in a particularly favorable manner in the Vergussbetonkörper 5.

The same arrangement can also according to the plate beams 12 FIG. 2 be used.

Overall, results from the reinforcement on the outer circumference of the Vergussbetonkörpers 5 a very rough surface 16 thanks to the wrapping body 26, which may preferably be formed as a round or square profiled helix 7.

The FIG. 6 shows a modified embodiment of the formation of the cladding. 8

It is shown a larger cladding tube 8a, in whose interior a cement injection 19 is attached, so that the aforementioned fat layer is eliminated. Thus, the cladding tube 8a is filled directly with a hardenable concrete as cement injection 19.

The FIG. 7 shows the perspective view of the anchor sleeve 1 according to the invention, where it can be seen that in the interior of the Gussankerhülse 4, the three-segmented clamping wedges 6 are arranged to apply a corresponding clamping force on the strand 9. It is also shown that the outer circumference of the Vergussbetonkörpers is surrounded over at least the substantial part of its length by the wrapping body 26, which is formed as a helix 7. The composite length 20 is about 25 to 35 cm.

In FIG. 8 a modified embodiment of a wrapping body 27 is shown, which replaces the coil 7.

Instead of a helix can according to a provided with slot openings 30 tube 28 are used, on the outer circumference of a plurality of discs 29 are arranged parallel and spaced from each other. Again, the advantage of the invention is achieved, namely on the one hand, the sheath of Vergussbetonkörpers 5 with an elastically expandable sheath body 26, 27 and at the same time a favorable anchoring of this sheathing body on the one hand in Vergussbetonkörper 5 and on the other hand in the surrounding, vorzuspannenden concrete 11th

The FIG. 9 shows the cast body 5 in its representation, as it is surrounded with the coil 7 as a wrapping body 26, wherein the cast anchor sleeve 4 is inserted in the front.

In the FIGS. 10 and 11 the cast anchor sleeve 4 is shown in more detail. It preferably consists of a Gussankerteil, z. B. of a material GGG40 with an upper and a lower peripheral flange, wherein the lower circumferential flange is formed as a collar 24, the bottom side of the force introduction surface 33 forms in the Vergussbetonkörper 5.

There is a conical jacket 21 is present, which defines an inside conical passage opening 25, in the interior of which also conical clamping wedges 6 are used.

On the outer circumference of the cone shell 21, a plurality of evenly distributed around the circumference arranged ribs 22 are arranged, which carry spiral grooves 23 for anchoring the coil 7.

Thus, it is made clear that both the helical groove 13 on the Vergussbetonkörper 5 and the helical groove 23 continue on the ribs 22, so that the coil 7 is also at least partially applied to the outer periphery of the Gussankerhülse 4 and there is anchored positively over the helical grooves 23 ,

Thus, the helix 7 also serves as a wrapping body 26 for enclosing the outer circumference of the cast anchor sleeve 4, in order also to impart improved strength of this cast anchor sleeve 4.

Thus, the two Gussumhüllungskörper 26, 27 described herein are elastically radially expandable.

In FIG. 12 the Vergussbetonkörper 5 is shown, and it can be seen that semi-open helical grooves 13 are present, in which the helical wire 31, 31 a, 31 b, 31 c of the helix 7 engages positively.

The same Vergussbetonkörper, but without showing the Gussankerhülse 4, is in FIG. 13 shown.

The FIGS. 14 to 16 show different profile shapes of a helical wire. The FIG. 14 shows here a round profiled helical wire 31 a, while the FIG. 15 a rectangular profiled helical wire 31 b and the FIG. 16 a ball-shaped helical wire 31 c shows.

drawing Legend

1

anchor sleeve

2

concrete slab

3

Front side (cast anchor 4)

4

Cast anchor sleeve

5

Vergussbetonkörper

6

Clamp wedge (3-fold)

7

spiral

8th

Cladding tube 8a cladding tube

9

braid

10

Grease layer (or 2K resin)

11

pretensioned concrete

12

T-beams

13

helical

14

helix surface

15

arrow

16

rough surface

17

arrow

18

rib

19

cement injection

20

composite length

21

conical surface

22

rib

23

helical

24

Federation

25

Passage opening (conical)

26

covering body

27

covering body

28

pipe

29

disc

30

slot opening

31

Coiled wire 31 a, 31 b, 31 c

32

arrow

33

Force introduction surface

34

35

tensioning device

Claims (14)

Anchor sleeve for the anchoring of prestressed reinforcement elements, in particular thin-walled, wide-tensioned components with prestressed steel strands or the like reinforcing elements, characterized in that the anchor sleeve (1) consists of a tensioning device (35), which the strand (9) or the reinforcing element against the Anchor sleeve (1) biases, a Gussankerhülse (4), in which the clamping device (35) is arranged and from a Vergussbetonkörper (5), which of the strand (9) or the reinforcing element on the clamping device (35) on the Gussankerhülse ( 4) absorbs introduced force and in the axial and radial direction of the Vergussbetonkörper at least partially enclosing wrapping body (7, 14, 29) passes on. Anchoring sleeve according to claim 1, characterized in that at the beginning of the anchor sleeve (1), the casting for the central implementation of Litzenquerschnitts is arranged and the receptacle for the inserted clamping wedge (6) that adjoins a cylinder of high-quality concrete, which adjoins the Gusshülse surrounds and forms the extension following the cast body and that the thus formed cylinder is enclosed by a helical reinforcement. Anchoring sleeve according to claim 1 or 2, characterized in that the helical reinforcement (7, 14, 29) absorbs the transverse forces in the cast body and surrounds the concrete cylinder. Anchoring sleeve according to at least one of the preceding claims, characterized in that the force introduced in the cast body force are delivered to the part via the lateral ribs (18) to the coil and the rest is registered on the head side of the adjoining concrete cylinder. Anchoring sleeve according to at least one of the preceding claims, characterized in that the concentrated load introduction is taken from the head of the casting sleeve on the concrete cylinder of the helical concrete cylinder and then release over the surface of the cylinder to the environment. An anchor sleeve according to at least one of the preceding claims, characterized in that instead of a helix as a wrapping body, a tube (28) provided with a plurality of slots (30) is used, which is integral with a plurality of discs (29) connected to the tube jacket attach and which are directed radially outward. Anchoring sleeve according to at least one of the preceding claims, characterized in that on the front side of the concrete slab (2) the end face (3) of the cast anchor sleeve (4) protrudes. Anchoring sleeve according to at least one of the preceding claims, characterized in that in the interior of the anchor sleeve, a triple-segmented clamping wedge (6) is arranged, which forms the clamping device (35) for applying the bias to the stranded wire (9). Anchoring sleeve according to at least one of the preceding claims, characterized in that on the outer circumference of the anchor sleeve (1) a helix (7) is arranged as a wrapping body (26). Anchoring sleeve according to at least one of the preceding claims, characterized in that the Vergussbetonkörper (5) in the interior of the wrapping body (26) is cast and thus partially surrounds the Gussankerhülse (4) and also laid in the interior strand (9). Anchoring sleeve according to at least one of the preceding claims, characterized in that the wrapping body (26) is formed as a helix (7) forming a plurality of helical turns, which in semi-open helical grooves (13) on the circumference of Vergussbetonkörpers (5) are embedded. Anchoring sleeve according to at least one of the preceding claims, characterized in that in the rear end side of Vergussbetonkörpers (5) a cladding tube (8, 8a) is poured, which is held in the material of the Vergussbetonkörpers (5), in the interior of the strand (9 ) is passed. Anchoring sleeve according to at least one of the preceding claims, characterized in that in the interior of the cladding tube (8) a fat layer (10) is arranged, which surrounds the stranded wire (9) on the circumference. Anchoring sleeve according to at least one of the preceding claims, characterized in that in the interior of the cladding tube (8a) a curable cement injection 19 is attached.

Images