DE8634914U1 - Locking block for shear force transmission in prefabricated structures - Google Patents

Description

Patent Attorneys Tergau & Pohl, Nuremberg Page 1

Description

6 Locking block for shear force transmission

7 in prefabricated buildings

a The invention relates to a locking block for shear force transmission between

io see two adjacent prefabricated parts of prefabricated buildings.

12 A butt joint related to the type of the subject matter of the invention

13 of two prefabricated concrete components is described in DE-PS 32 08 350. Accordingly

µm, two precast concrete components form a grouting or assembly groove at their joint,

is recessed from above and arranged in the clamping devices

ie are. The casting or assembly groove has, in addition to the clamping devices

&igr;? receiving areas has a cross-section that narrows towards the top.

ie In these cavity-like parts under the constrictions, adjusting bodies are in

ie the cross-section of the assembly groove. This means that both finished components

20 are locked together after they have been braced. It takes place at a right

21 deflection of one prefabricated component at an angle to the joint sides

22 by means of the adjusting body a transmission of the associated shear force

23 onto the adjacent prefabricated component. This measure ensures

24 joint protection during and after the construction period, the joint damage, such as

25 cracks, dislocations, etc. are prevented. The gaps formed by filling the casting groove

26 The joint is the most important connection between two prefabricated components,

27 such as ceiling panels. It must be able to withstand the shear stress

28 effect to transfer loads from one slab to the other. In addition, 2&bgr; it should be able to use the adhesive strength of the cast concrete to the precast

30 partial edges and its tensile strength also allows tensile forces between the plates

31. Both functions require undisturbed curing of the joint

32 betons in the groove ahead. This requires a rest period of days, during

33 the joints must be protected from all harmful influences. How

34 The importance of joint protection is illustrated by the following numerical example:

35. Even walking on a ceiling slab can cause this bending vibration

36 generate shocks of more than 5 mm amplitude, which may cause destruction of the

37 Concrete structure of the not yet hardened grouting joint.

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June 6, 1991

Patent Attorneys Tergau & Pohl, Nuremberg Page 2

r Disadvantageous for the locking block acting as a joint lock according to

2 The state of the art is the fact that it already consists of

3 placing the two prefabricated components in the upwardly narrowed casting groove

4. The adjusting body could be inserted from the side via the recess

5 ments for the clamping devices can be inserted subsequently, however

6 difficulties arise here, since for a perfect power transmission

7 and joint protection of the adjusting body must have only a very small, ideally &bgr; no play with the side edges of the casting groove.

9 given tolerances, subsequent insertion from the side is then

10 is often no longer possible or only possible with greatly increased effort.

12 The invention is based on the object of providing a locking block of the

13 type mentioned above, which is structurally simple, even after the

14 laying of precast concrete elements and improved properties

15 visible joint protection and shear force transfer between the two

16 ton prefabricated parts.

ie This task is carried out in accordance with the characterising features of the claim

19 ches 1. Accordingly, the locking block consists of three in assembly

20 End position with alternating wedge direction on facing

21 wedge surfaces of adjacent wedges each with essentially right-angled

22 Ng to the shear force direction arranged wedge plane. The two

23 outer wedges with their opposite outer wedge surfaces against each other

24 facing surfaces of the finished parts by means of the

25 inner wedge under press fit. The contact wedge surfaces for mutual contact

26 of outer wedges and inner wedge are provided with an interlocking, in

27 provided with corrugations running in the direction of the wedge angle.

29 For the locking block, a groove narrowed towards the top is no longer necessary.

30 manoeuvrable, through which power transmission via a form-locking connection

si would take place. In contrast, flat, facing surfaces

32 of the finished parts are used, which are spaced so that the locking

33 block can be inserted from above at any time. Since the friction coefficient of Be-

34 clay surfaces is very high, sufficient for a safe shear force transmission of the

35 friction-related press fit of the two outer wedges on these surfaces. This shear force transfer between the two outer wedges takes place through the inner

37 nenkeil, whereby the corrugation running in the wedge angle direction creates a

38 Positive connection between the three wedges is provided. As corrugation

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Patent Attorneys Tergau & Pohl, Nuremberg Page 3

&igr; any surface structuring can be considered in which form-fitting

2 the two adjacent wedge surfaces engage in the direction of shear force.

3 are fixed in position against each other. This ensures reliable power transmission in

4 within the multi-part locking block.

6 Another advantage is the fact that the locking between the two

7 finished parts no longer depends on a tolerance-sensitive form-fitting connection &bgr; between the finished parts and a one-piece locking block, &bgr; but solely on driving the inner wedge between the two outer wedges.

10 If the two facing surfaces of the finished parts are slightly

11 too far apart, the inner wedge is simply placed a little further between the

12 both external wedges are driven in. If several of the locking blocks

13 distributed between the two adjacent prefabricated parts, in contrast to the state-of-the-art design, a reliable shear force transmission is ensured at each of the assembly points, since the locking blocks 16 can independently compensate for different distances between the two facing surfaces of the prefabricated parts.

ie The characterizing part of claim 2 specifically describes the arrangement of the inventive

20 locking block for ceiling panels of prefabricated ceilings.

21. This joint protection measure makes it possible to create a finished

22 partial ceiling, to be fitted with the locking blocks, in horizontal

23 valley direction by means of clamping devices, the casting groove with

24 to fill the joint concrete and immediately start the construction of the building.

25 ginnen.

26

27 The locking blocks, in conjunction with the clamping units,

28 directions, an immediate tensile and shear-resistant plate connection is created, 28 which means that no harmful influences can be exerted on the hardening casting joint. 28 After the joint casting has hardened, the locking

31 support blocks and the horizontal bracing provide an additional, statically

32 visible joint reinforcement.

33

34 If the two outer wedges are arranged with a longitudinal offset to each other,

35 On the other hand, for a given joint width, the distance between the two adjacent

36 facing wedge surfaces of the outer wedges are larger (claim 3). This allows the

37 The inner wedge has an increased material thickness, which makes it more stable and improves the force transmission within the locking block.

June 6, 1991

634 914..

Patent Attorneys Tergau & Pohl, Nuremberg Page 4

2 The characterizing features of claims 4 and 5 define the force

3 The seal between the respective prefabricated parts and the outer wedges has been improved.

4 In addition to the press fit between these components, the engagement of the

5 projections of the outer wedges in recesses in the facing surfaces of the finished parts, a positive connection is achieved. In addition, this enables the outer wedges to be held automatically on the finished parts. These can even be installed in the factory during the manufacture of the individual finished parts.

9 can already be fixed using the recesses. This reduces the

10 Time required for final assembly on site, for example of a prefabricated part—

11 ceiling considerably.

13 Claims 6 and 7 give favourable wedge angle ratios and sizes for

η the outer and inner wedges. Due to the relatively small size of the wedge angles

According to claim 7, a particularly high frictional connection between the wedges

ie of the locking block. In addition, with very acute wedge angles

&igr;? a better fixation of the inner wedge between the two outer wedges

is given to the casting of the groove.

20 A low-toughness, stable and highly elastic material has proven to be an advantageous material for the wedges.

21 solid plastic material, such as polystyrene. The

22 Material adapts particularly well to unevenness in the concrete surfaces,

23 nestles into it and thus increases the press fit between

24 the locking block and the precast concrete elements. A friction coefficient

25 ficient so high that the inner wedge after being driven in between the two

26 external wedges are independently and permanently fixed.

28 The invention is described in an embodiment with reference to the accompanying figures.

29 guren explained in more detail. They show:

31 Fig. 1 a plan view of the locking block in final assembly position in

32 a casting groove,

33 Fig. 2 a view of the locking block from the direction of arrow II according to

34 Fig. 1 before inserting the inner wedge,

35 Fig. 3 the top view of a complete tension and shear resistant bracing between two ceiling panels of a precast ceiling.

June 6, 1991

634 914..

b si Patent Attorneys Tergau & Pohl, Nuremberg Page 5

&igr; The locking block (1) according to the invention serves to transmit shear forces

ζ between two adjacent ceiling panels (2,2') of a prefabricated ceiling. The

3 ceiling panels (2,2') form a ceiling panel accessible from above at their vertical edges (3).

4 lye casting groove (4), the groove base of which is formed by the two projections (5,5')

5 of the lower plate level of the two ceiling plates (2,2'). In &bgr; their central area with respect to the height direction, the vertical edges

7 of the (3,3') indentations (6) to reinforce the casting groove (4).

o The area of the two parallel sections above the

10 vertical edges (3,3') arranged locking block (1) consists of three in

11 Final assembly position with consecutively alternating wedge angle direction

12 (7) on each of the wedge surfaces (8) facing each other

13 wedges (9,10,11) with essentially perpendicular to the shear force direction (12)

14 arranged

Wedge plane. Wedge plane is the main plane spanned by the respective wedge angle.

The two outer wedges (9,11) rest with their opposite outer wedge surfaces (13) against the facing vertical edges (3,3') of the ceiling panels (2,2') with a press fit. The press fit is achieved by driving the inner wedge (10) between the two outer wedges (9,11).

The wedge surfaces (8) for the mutual contact of the outer wedges (9,11) and the inner wedge (10) are each provided with an interlocking groove (14) running in the wedge angle direction (7).

According to Fig. 2, the corrugations (14) are formed by elevations (15) which are triangular in cross-section and equidistant from one another and run in the wedge angle direction (7) on the wedge surfaces (8).

As shown in Fig. 1, the two outer wedges (9, 11) are arranged offset from one another in the wedge direction (7). The length offset corresponds to approximately one third of the total length of a wedge (9, 11). This maintains a sufficiently large contact area between the wedges (9, 10, 11), while at the same time the inner wedge (10) essentially acts in its central region, which already has a considerable material thickness.

To improve the force flow between the outer wedge surfaces (13) of the wedges (9,11) and the ceiling panels (2,2'), the outer wedge surfaces (13) each have hemispherical projections (16) which are inserted into recesses (17) in the mutually facing vertical

edges (3,3') of the ceiling panels (2,2'). Due to the intimate connection of these two components, an adhesion between the outer wedges (9,11) and the ceiling panels (2,2') is already achieved before the inner wedge (10) is driven in. This means that when assembling the locking block (1), the two outer wedges (9,11) do not necessarily have to be held by hand before the inner wedge (10) is driven in.

Due to the geometric conditions, the wedge angles of the outer wedges (9,11) and the inner wedge (10) are 1:2. Specifically, the wedge angle of the outer wedges (9,11) is about 5°, that of the inner wedge (10) is about 10°.

The wedges (9,10,11) are made of a low-elastic, stable plastic material - for example polystyrene.

The method for the tensile and shear-resistant connection of two ceiling panels (2,2') of prefabricated ceilings, which form a casting groove (4) with their vertical edges (3,3*) facing each other, can be explained with reference to Fig. 3.

In opposite recesses (18) on the vertical edges (3,3') of the ceiling panels (2,2') tensioning loops (19) are arranged in flush relation, which are formed by the bent ends of reinforcing steel. A turnbuckle (20) is placed between these tensioning loops (19), which engages with its two connecting links (21) in each of the tensioning loops (19). Both connecting links (21) can be pushed towards each other by two tensioning screws (22), whereby the two tensioning loops (19) and thus the ceiling panels (2,2')

against each other by tightening the clamping screws (22).

After tightening the possibly several turnbuckles (20), the outer wedges (9,11) are each inserted into the laterally offset recesses (17) in the vertical edges (3,3') of the ceiling panels (2,2"). The inner wedge (10) is then driven in between the two facing wedge surfaces (8) until the guide wedges (9,11) are fixed with a press fit in relation to the ceiling panels (2,2") and the inner wedge (10). During the driving in, a force is simultaneously exerted on the turnbuckle (20) in the opposite direction to the clamping direction (23).

By re-tightening the clamping screws (22), this can be compensated and a particularly tensile and shear-resistant connection between the two ceiling panels (2,2') can be achieved. This is particularly the case when, as shown in Fig. 3, two locking blocks (1) are used on either side of the turnbuckle (20). The assembly work is particularly simple if the driving direction (24) of the two inner wedges (10) is directed towards each other.

After the described tensioning and locking process, the casting groove (4) is cast with concrete and a casting joint is created for further shear and tensile connection. In particular, this protection against tensile and shear forces allows the casting concrete to harden without harmful influences from footstep vibrations and load deflections. It thus creates an inherently stable, solid joint.

634 914..

Reference symbols

1 locking block 2.2' ceiling panel 3.3' vertical edge

4 Groove
5.5' impact projection

6 Indentation

7 Wedge angle direction

8 No Lf Lache

9 KeiL

10 Kei L

11 KeiL

12 Direction of force

13 External wedge surface

14 Riffelung

15 Survey

16 Lead

17 Recess

18 Recess

19 tensioning loops

20 Spannsch Loss

21 Connecting link

22 clamping screw

23 Tension direction

24 Driving direction"

Claims (1)

Patent attorneys Tergau & Pohl, Nuremberg Page ■ , 86827-2/13 6 G 86 34 914.7 - Veit Dennert KG 8 6 June 1991 11 Claims u 1. Locking block for shear force transmission between two adjacent is prefabrication of prefabricated buildings, It is characterized by the following features: 17 The locking block (1) consists of three in the final assembly position with 18 successively alternating wedge angle direction (7) on each other the facing wedge surfaces (8) of adjacent wedges (9,10,11) with 20 wedge arranged essentially at right angles to the direction of shear force (12)— 21 level, where 22 - the two outer wedges (9,11) with their opposite outer wedge surfaces 23 surfaces (13) on mutually facing surfaces of the finished parts by means of the 24 between them driveable inner wedge (10) under press fit and 25 - the wedge surfaces (8) for the mutual contact of external wedges (9,11) and 26 Inner wedge (10) with an interlocking, in the wedge angle direction 27 groove (7) extending along the longitudinal axis (12). 29 2. Locking block according to claim 1 for use in casting grooves (4) of Prefabricated ceilings for shear force transmission between two butt-jointed 31 arranged ceiling panels (2.2'), 32 characterized by 33 that the wedges (9,10,11) are arranged with a horizontal wedge plane, whereby the 34 two outer wedges (9,11) with their opposite outer wedge surfaces 35 chen (13) rest on the mutually facing vertical edges (3,3') of the ceiling panels (2,2') forming the casting groove (4). 634 en.. 6 June 1991 (U:\AN\86827B.TXT) Patent Attorneys Tergau & Pohl, Nuremberg Page Ii &igr; 3. Locking block according to claim 1 or 2, 2 characterized by 3 that the two outer wedges (9,11) are aligned in the wedge angle direction (7) 4 sets are arranged. 6 4. Locking block according to one of the preceding claims, 7 characterized by β that the outer wedge surfaces (13) of the outer wedges (9,11) are each provided with 9 jumps (16) are formed, which in recesses (17) in the mutually 10 facing surfaces of the finished parts. 12 5. Locking block according to claim 4, 13 characterized by &eegr; that the projections (16) and recesses (17) are hemispherical with approximately the same radius. 17 6. Locking block according to one of the preceding claims, 18 characterized by 19 that the wedge angles of the outer wedges (9,11) and the inner wedge (10) are 1:2 20 behavior. 22 7. Locking block according to claim 6, 23 characterized by 24 that the wedge angle of the outer wedges (9,11) is about 5°, that of the inner wedge (10) 25 is about 10°. 27 8. Locking block according to one of the preceding claims, 28 characterized by 29 that the wedges (9,10,11) consist of a slightly tough-elastic, stable solid plastic material, preferably polystyrene. 34 914.