EP3456902A1 - Lost formwork for concrete constructions - Google Patents

Abstract

The invention relates to a permanent formwork for concrete construction, which has a formwork panel and a rod-shaped anchoring means for this. According to one aspect of the invention, the rear anchoring device comprises two tension rods which overlap in the space of the first concreting section and which are held together there by means of an eccentric turnbuckle. Further aspects of the invention relate to a claw for suspending the anchoring device in the static reinforcement and a securing element against spreading of a hook-shaped drawbar end.

Description

A permanent formwork, in particular a joint formwork, for concrete construction has a substantially concrete-impermeable shuttering wall which is erected on a base, usually a static reinforcement layer consisting of longitudinal and transverse bars. The formwork panel then forms the boundary between a concrete section BA1 to be cast first and a second concrete section BA2 to be cast temporally thereafter. The hydrostatic pressure building up in the BA1 during pouring through the flowable concrete produces a considerable force which the formwork panel tries to displace or tilt away from the BA1 in the direction of the BA2. To stabilize the formwork panel against the hydrostatic pressure, back anchoring devices are used which clamp the formwork panel against the base.

From the EP 2 157 260 A1 Such a back anchoring device is known. It has a pull rod, which is hung at one end with a hook-shaped end in the static reinforcement and pushed with the other end through the formwork panel. At the end of the pull rod protruding there is a thread on which a lock nut is screwed, with which the pull rod is secured against being pulled out of the formwork panel and the return anchoring device is tensioned. This known Rückverankerungseinrichtung works well, but requires the formation of a thread on the tie rod and the screwing a lock nut, which is not always easy in rough construction.

Another Rückverankerungseinrichtung, also for a working joint formwork, is from the DE 20 2009 004 804 U1 known. There, a pull rod or a strong pull wire is hung with one end via a shackle in the static reinforcement and inserted through the formwork panel with the other end. This other end is then bent so that it protrudes substantially perpendicularly from the formwork panel towards the BA2. On this projecting end a so-called eccentric turnbuckle, also called cock frog, pushed until it rests against a stiffening part of the formwork panel and then clamped. As a result, the pull rod is secured against retraction. However, a tensioning or a length adjustment of the tension rod is hardly possible here, since the tension rod is bent in the formwork panel and the break point is difficult to be pulled over the bending edge on the formwork panel.

From the EP 2 157 260 B1 Finally, a back anchoring device is known in which a pull rod is suspended by using a wavy curved from a bar bracket in the static reinforcement. The bracket is designed so that the tensile force occurring during concreting in the tie rod is converted by the bracket into a clamping force that compresses crossing longitudinal and transverse bars of the static reinforcement in the hooking area of the bracket.

The invention has for its object to provide a permanent formwork for concrete construction, which is functionally improved over the prior art described above.

In a first aspect of the invention, this is based on a formwork according to DE 20 2009 004 804 U1 consisting of a formwork wall and a rod-shaped anchoring means which can be coupled with a first end to the static reinforcement or a ground anchor and with a second end to the formwork wall and fixed by means of an eccentric turnbuckle. This formwork is improved by the characterizing features of claim 1. The two tension rods are easily accessible in the overlap area and can easily be adjusted to the correct length and tensioned with the turnbuckle loosened, without the need for bending rods. This simplifies and improves the handling of the anchoring device in the construction.

Preferably, the formwork according to claim 2 is formed. The fact that the eccentric turnbuckle in the installed state points downwards, ensures that the operating lever of the turnbuckle is not accidentally brought into the release position when shaking the concrete in the BA1 section.

A second aspect of the invention is based on a formwork according to EP 2 157 260 B1 in which the rear anchoring device has an intermediate member, by means of which it can be suspended with the first end in the static reinforcement such that the tensile force acting on the intermediate member Rückverankerungskraft partially in a transverse and longitudinal bars of the static reinforcement in a crossing region of the rods compressive clamping force is implemented. The intermediate link here is a multi-curved bracket, which is cumbersome to manufacture and handle.

According to the second aspect of the invention it is provided that the formwork according to the characterizing part of claim 3 is formed. In place of the multiply bent stirrup according to EP 2 157 260 B1 occurs according to the invention a simple to manufacture and easily hooked into the static reinforcement claw which not only allows a simple and quick hooking the Rückverankerungseinrichtung in the static reinforcement, but also effectively each presses a single longitudinal and a single cross bar in the Einhängebereich so tightly that even with high re-anchoring forces displacement-free coupling between back anchoring device and static reinforcement is ensured.

Advantageous developments of the invention according to its second aspect are given in the claims 4 to 15.

A third aspect of the invention aims at improving the hooking of a hook-shaped tie rod end of the rear anchorage device of a formwork into the formwork board or the static reinforcement. In known formwork, for example in those after EP 2 157 260 A1 , one end of the tie rod of the anchoring device is bent back hook-shaped and can be hung with this end either on a stiffening part of the formwork panel or on the static reinforcement. Formworks are also known in which the tension rods of the rear anchoring device are bent back in a hook-shaped manner at both ends.

If very high re-anchoring forces occur, it is possible that the hook-shaped end of the tension rod is spread open and it comes loose from the formwork panel or the reinforcement. The expandability of the hook on the tension rod therefore limits the back anchoring force that can be applied in the back anchoring device.

According to the third aspect of the invention, this problem is reduced or at least reduced by the fact that the anchoring device according to claim 16 is formed. By a simple securing the hook end against spreading can be transferred with otherwise the same dimensions and materials of the anchoring device significantly higher Rückverankerungskräfte.

A structurally particularly simple embodiment of the securing element can be found in the patent claim 17. It is designed here as a sheet-metal part with a pair of openings, in which on the one hand the tension rod and on the other hand its bent-over end are inserted.

An even greater protection against spreading can be achieved by the feature of claim 18.

The handling is further simplified if according to claim 19, the securing element is firmly connected to the formwork wall.

A particularly high security force can be achieved with the feature according to claim 20, because there the securing forces are applied by a stable U-profile.

The above-described three aspects of the invention, when used together, result in an optimum result for a formwork anchoring means. But also a joint application of only two of the aspects or a single aspect leads to a significant improvement of the anchoring device over the prior art, so that protection is claimed individually for any combination of the described aspects of the invention and for each aspect.

Figur 1

eine schematische Seitenansicht einer erfindungsgemäßen Schalung für eine Arbeitsfuge;

Figur 2

eine der Figur 1 entsprechende Seitenansicht einer erfindungsgemäßen Schalung für eine Dehnungsfuge;

Figur 2a

ein Detail zu Figur 2,

Figur 3

Varianten der Verbindung der Rückverankerungseinrichtung mit der Schalungswand in Seitenansicht;

Figur 3a

eine perspektivische und

Figur 3b

eine Draufsicht auf die Varianten nach Figur 3;

Figur 4

eine perspektivische Ansicht einer in der Rückverankerungseinrichtung der erfindungsgemäßen Schalung einzusetzenden Klaue;

Figur 4a

eine Draufsicht auf einen Blechzuschnitt, aus dem die Klaue nach Figur 4 biegbar ist;

Figur 5

eine perspektivische Ansicht der Einsatzstelle der Klaue nach Figur 4; und

Figur 6

eine Variante der Klaue nach Figur 5.

The invention will be explained with reference to embodiments in conjunction with the drawings. Show it:

FIG. 1

a schematic side view of a formwork according to the invention for a working joint;

FIG. 2

one of the FIG. 1 corresponding side view of a formwork according to the invention for an expansion joint;

FIG. 2a

a detail too FIG. 2 .

FIG. 3

Variants of the connection of the anchoring device with the formwork wall in side view;

FIG. 3a

a perspective and

FIG. 3b

a plan view of the variants after FIG. 3 ;

FIG. 4

a perspective view of a claw to be used in the Rückverankerungseinrichtung the formwork according to the invention;

FIG. 4a

a plan view of a sheet metal blank from which the claw to FIG. 4 is bendable;

FIG. 5

a perspective view of the point of use of the claw after FIG. 4 ; and

FIG. 6

a variant of the claw after FIG. 5 ,

This in FIG. 1 illustrated embodiment of a formwork according to the invention for concrete construction has a shuttering wall 1, with a construction gap between a first to be concreted construction section BA1 and then to be concreted concrete section BA2. The formwork wall 1 contains a formwork panel 2, which consists of a partially permeable, but the concrete in the BA1 restrained material, in particular an expanded metal. The formwork panel 2 is stiffened in a known manner on the side facing the BA1 with lattice girders 3 and a connecting rod 4 connecting them and welded to their upper girths. The formwork wall is upright on the static reinforcement 5 of the concrete component to be produced, for example, a foundation plate, set up, which consists of longitudinal bars 6 and transverse bars 7 and is supported on a cleanliness layer 8 by means of spacers 9 in a conventional manner. The static reinforcement 5 could also consist of several layers of longitudinal and transverse bars, but only one layer is shown.

A generally designated 10 Rückverankerungseinrichtung secures the formwork wall 1 against displacement or tilting under the build-up in BA1 concrete pressure. The Rückverankerungseinrichtung is coupled in a manner to be described with a, in the drawing, the left end with the static reinforcement 5 and the other, in the drawing right end to the formwork wall 1 in a manner also to be described.

The anchoring device 10 has tie rods 11 and 12, which consist of structural steel and, for example, have a diameter of 10 mm. The otherwise straight tension rods 11, 12 each have one end hook-shaped bent back ends 11a, 12a with straight end portions 11b, 12b. The other end portions of the tie rods 11, 12 overlap in the space of the BA1 in an overlap region 13. With a pull rod 11 is in the overlap region 13, a commercial eccentric turnbuckle 14, in practice also called "cock frog" so firmly connected that it points in the drawn operating position down. Such a commercially available turnbuckle has a dash-dotted line passage 15 at 15, through which the straight end of the pull rod 12 in the overlapping region 13 is hindurchschiebbar. In the passage 15 a not shown in the drawing, usually toothed eccentric protrudes under the pressure of a spring, which can be swung out of the passage 15 by means of an operating lever 16.

By correspondingly deep insertion of the straight end of the tension rod 12 in the passage 15, the length of the anchoring device 10 can be adjusted to the desired level and the Rückverankerungseinrichtung be biased. This position can then be fixed by releasing the spring-loaded eccentric by means of the operating lever 16.

The length adjustment of the rear anchoring device 10 and its bias can thus be accomplished in an easily accessible place and without bending the tension rods. A release of the fixation when shaking the concrete in concreting BA1 is not to be feared, since the eccentric turnbuckle 14 is protected below the tie rods 11, 12.

The rear anchoring device 10 is hooked by means of the hook-shaped bent-back end 12a of the tension rod 12 in the stiffening structure 3, 4 of the formwork wall 1, in the illustrated embodiment so that the hook-shaped end 12a comprises the upper flange of one of the stiffening lattice girder 3.

The coupling of the anchoring device 10 with the static reinforcement 5 via an intermediate member 17 which is configured such that the transferred by the rods 11, 12 Rückverankerungskraft R partially in a longitudinal bar 6 and a transverse bar 7 in the crossing region compressive clamping force K, K. is implemented. Details of this construction will be discussed below with reference to FIGS Figure 4-6 explained.

FIG. 2 shows the Rückverankerungseinrichtung 10 in conjunction with a shuttering wall 1 'for producing an expansion joint. Here, the formwork wall 1 'contains a formwork panel 2', which contains a parting line insert 18. The rear anchoring device 10 is hooked into the in this case BA2-side stiffening structure 3 ', 4' by means of a formwork panel 2 'passing through the cable loop 19.

An inventive feature of the FIG. 2 illustrated embodiment is that the hook-shaped bent-back end 12a of the pull rod 12 is provided with a securing element 20 which prevents spreading of the hook-shaped end 12a under the back anchoring force R. This securing element 20 is in FIG. 2a shown in perspective and consists of a sheet metal part 21, which could be formed as a simple plate, in the preferred embodiment, however, in the FIG. 2a evidently folded like a roof. In the roof legs 21a, 21b it contains spaced apart, with respect to the legs aligned openings 22, 23. The pull rod 12 is inserted after hanging in the cable loop 19 with its straight end through the openings 22 and with its end portion 12b through the openings 23, before the straight end of the pull rod 12 in the eccentric Turnbuckle 14 is introduced. As a result, the hook-shaped end 12a can not spread under the effect of the tensile force R, which significantly increases the transmittable return tension force R.

The Figures 3, 3a and 3b show variants of the fuse element. In the upper part of Figure 3 it consists of a U-profile 24, in the back part 24a, the openings 22, 23 are incorporated. This U-profile 24 is welded to the stiffening structure 3 of an in turn made of expanded metal formwork panel 2 a Arbeitsfugenschalung. The insertion of the bent-back end 12a of the tension rod 12 takes place in a manner analogous to that in FIG Figure 2, 2a ,

In the lower part of FIG. 3 the securing element is designed as a simple sheet metal plate 25 which is welded onto parallel stiffening rods 26 of the stiffening structure 3.

The embodiments according to FIGS. 3, 3a, 3b have the advantage that the security elements are permanently connected to the formwork. The training as a U-profile 24 has the advantage of particularly high strength and thus a further increase in the transferable Rückverankerungskraft.

As from the slightly enlarged, perspective view of the intermediate member 17 in FIG. 4 it can be seen, this invention consists of a claw 27, which has a J- or L-shaped in side view (see also FIGS. 1 and 2 ). The claw 27 has a substantially rectilinear back portion 28 corresponding to the vertical J or L leg and a leg portion 29 laterally projecting from the lower end of the back portion 28, corresponding to the J-arc or short L-leg. The claw 27 is off a solid, for example, 4 mm thick sheet steel sheet bent, the blank in FIG. 4a is shown.

The back part 28 has at its lower end a rounded support surface 30. The opposite, upper end of the back portion 28 is provided with a rounded notch 31. The fillet at 30 corresponds to the diameter of a longitudinal bar 6 of the static reinforcement and the fillet at 31 is adapted to the diameter of the pull bar 11. Between the support surface 30 and the notch 31 is the back part 28th provided with an opening 32 whose diameter is slightly larger than the diameter of the tension rod 11.

Due to the production of the claw 27 by bending a flat material, the back part 28 has a U-shaped cross-section with U-legs 33 and a U-web 34. In the latter, the support surface 30, the notch 31 and the opening 32 are formed. The U-legs 33 continue down in laterally projecting from the back part 28 hook parts 35, which form spaced flanks 29 a of the leg portion 29. The hook portions 35 enclose therebetween a distance a, so that in the leg portion 29, a gap 36 is formed, the distance a corresponding width must be at least as large as the diameter of the longitudinal bar. 6

In the hook parts 35 cutouts 37 are incorporated, which are open to the top and are adapted in their contour to the circumference of a cross bar 7 of the static reinforcement 5. This results in the leg portion 29 a rounded receptacle 38 for a transverse bar 7, the side a distance b (see. FIG. 4a ) from the support surface 30 has.

The hook parts 35 form on their upper sides securing lugs 39, with which they overlap the cutouts 37 partially so that although a cross bar 7 can be inserted into the receptacle 38, but this is prevented from sliding out of the receptacle upwards.

In the cut to FIG. 4a are appropriate dimensions entered for the claw. Deviations from these dimensions by about 30% upwards and about 10% downwards are conceivable, depending on the field of use of the claw. The blank is bent around the bending lines B, whereby the claw after FIG. 4 arises.

The practical use of the claw 27 is in FIG. 5 shown. The tension rod 11 of the anchoring device is inserted with its bent-back tension rod part 11b into the opening 32 and rests in the recess 30 in such a way that it and thus the back anchoring force R transmitted by it form an angle α (cf. FIG. 2 ) forms with the longitudinal axis of the back portion 28.

With the support surface 30, the claw 27 rests on the longitudinal bar 6, which in turn crosses the transverse bar 7, which is supported in the receptacle 38. The at the angle α at the back portion 28 of the claw 27 at a distance above the support surface 30 attacking back anchoring force tries the claw 27 in FIG. 5 to pivot the support surface 30 as a pivot point to the rear, into the image surface inside. This will get the Hook parts 35 tend to rotate upward, but this is prevented by the abutment of the receptacle 38 on the underside of the transverse bar 7 crossing the longitudinal bar 6. From the re-anchoring force R is thus derived from a first force acting on the supporting surface 30 from above on the longitudinal bar 6, and a second force which presses on the receptacle 38 from below against the transverse bar 7. These two forces together give the clamping force K, which press the longitudinal bar 6 and the cross bar 7 at its intersection so tightly that a mutual displacement of the bars is excluded. The gripping force becomes larger the larger the back anchoring force is.

Out FIG. 6 It can be seen that the hook parts 35 of the claw 27 need not necessarily be approximately parallel to each other. Rather, the blank can after FIG. 4a around the bending line B also by less than 90 °, for example by 60 °, are bent, whereby the claw 27 then the FIG. 6 apparent form receives in which the hook portions 35 between them an angle β of approximately 60 °. The variant after FIG. 6 is easier to hook into the static reinforcement. Another advantage of this variant is that even with oblique train of the anchoring device on the jaw on this a high, the intersecting reinforcing bars compressive tipping moment arises. Furthermore, this shape of the claw when pouring the concrete better filled with fresh concrete, as it can flow more easily into the larger space between the splayed hook parts.

The invention is not limited to the illustrated embodiments. In particular, the claw 27 need not be bent from a steel sheet. It could also be milled and drilled from scratch, but this would cause significantly higher production costs. The claw could also be welded together from several parts or produced as a casting. Further, in the formwork instead of a permeable formwork panel and a full-surface panel, such as a closed sheet metal could be used.

Claims (19)

Permanent formwork for concrete construction, comprising a formwork wall (1) and a rod-shaped anchoring device (10) which can be coupled to the static reinforcement (5) or a ground anchor with a first end and to the formwork wall (1) by means of a second end Eccentric turnbuckle (14) can be fixed,
characterized,
in that the rear anchoring device (10) has two tension rods (11, 12) overlapping between the two ends (11a, 12a), the first (11) of which forms the first end (11a) and the second (12) of which forms the second end (12a) and in that the eccentric turnbuckle (14) in the overlapping area (13) of the tension rods (11, 12) is fastened to one (11) of the tension rods and receives the other tension rod (12) displaceably and lockably by the eccentric. Formwork according to claim 1,
characterized,
in that the eccentric turnbuckle (14) is fastened to the associated pull rod (11) in such a way that it points downwards from the pull rod (11) when the formwork is installed. Shuttering, in particular according to Claim 1, in which the anchoring device (10) has an intermediate element (17) by means of which it can be suspended with the first end into the static reinforcement (5) such that the rear anchoring force acting as a tensile force on the intermediate element (17) (R) is partially in a transverse and longitudinal bars (6, 7) of the static reinforcement (5) in a crossing region of the bars compressive clamping force (K, K) is converted,
characterized,
in that the intermediate element (17) has a J-shaped or L-shaped claw (27) in side view with a back part (28) corresponding to the vertical J or L leg and a J-bend or the short L-leg, from the lower end of the back portion (28) laterally projecting leg portion (29), wherein at a distance from the lower end of the back portion (28) on this means for introducing the Rückverankerungskraft (R) at an angle (α) to the longitudinal axis of the back part (28) and in the region of the lower end of the back part (28) a support surface (30) for placing on a longitudinal bar (6) of the static reinforcement (5) on the leg part (29) are formed, and wherein at the lateral distance (b) from the support surface (30) an upwardly open receptacle (38) for the longitudinal bar (6) crossing transverse bar (7) of the static reinforcement (5) is formed. Formwork according to claim 3,
characterized,
in that the leg part (29) has two flanks (29a), in the tops of which the receptacle (38) for the transverse bar (7) is worked in and between them a space open at the bottom and upwards a gap (30) reaching at least to the supporting surface (30). 36) whose width is at least as large as the diameter of the longitudinal bar (6). Formwork according to one of claims 4 and 5,
characterized,
in that the claw (27) is integrally bent from a flat material, such that the back part (28) acquires a substantially U-shaped cross section, and the flanks (29a) of the leg part (29) extend through from the U-limbs (33) , hook portions (35) spaced from each other are formed. Formwork according to claim 5,
characterized,
that the flat material is sheet steel. Formwork according to claim 6,
characterized,
that the steel sheet is about 3 - 6 mm, preferably 4 mm thick. Formwork according to at least one of claims 3 to 7,
characterized,
is that the support surface (30) on the lower end side of the U-legs (33) of the back part connecting (28) U-web (34) and is preferably rounded. Formwork according to at least one of claims 3 to 8,
characterized,
that the receptacle (38) as approximately aligned, rounded cutouts (37) in the hook parts (35). Formwork at least according to claim 9,
characterized,
in that the cutouts (37) in the area of the free ends of the hook parts (35) are delimited by securing lugs (39) which, with the claw (27) inserted into the static reinforcement (5), move the transverse bar (7) in the direction of the supporting surface (30 ) partially overlap. Formwork according to at least one of claims 3 to 10,
characterized,
in that the hook parts (35) extend essentially parallel to one another at a distance (a) of approximately 20-30 mm, preferably 25 mm, or enclose an angle (β) of up to approximately 60 °. Formwork according to at least one of claims 1 to 11,
marked by
a claw (27) as shown in Figure 4. Formwork according to at least one of claims 3 to 12,
characterized,
in that the means for introducing the back anchoring force (R) have an opening (32) of the back part (28) into which a tension rod part (11b) can be suspended. Formwork according to at least claim 13,
characterized,
that the opposite of the support surface (30) end of the back part (28) has a conveniently rounded indentation (31) for engaging the pull rod (11). Formwork, in particular according to at least one of claims 1 to 14,
characterized,
in that a hook-shaped bent-back end (12a) of a pull rod (12) of the rear anchoring device (10) is provided with a securing element (20) preventing the hook-shaped end (12a) from spreading open. Formwork, at least according to claim 15,
characterized,
in that the securing element (20) consists of a sheet-metal part (21) having two openings (22, 23) spaced apart from one another, wherein the tension rod (12) can be guided through one opening (22) and its bent-back end section (12b) into the other opening (12). 23) can be inserted. Formwork, at least according to claim 16,
characterized,
that the sheet metal part (21) a roof-like folded, and openings (22, 23) in pairs and in alignment in two roof legs (21a, 21b) are arranged. Formwork, at least according to claim 16,
characterized,
that the sheet metal part (24, 25) is firmly connected to the formwork wall. Formwork, at least according to claim 18,
characterized,
that the sheet metal part forming the back (24a) of a welded to the shuttering wall U-profile (24).

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