Expansion joint formwork with clamping device

Abstract

The present invention relates to an expansion joint formwork for installation between a first section 1 to be concreted and a second section 2 to be concreted subsequently in concrete construction, for the purpose of forming an expansion joint between the sections 1 and 2, comprising a permanent formwork element 3 which has a formwork wall 4 containing a deformable expansion joint insert 5 between cover plates 6 on both sides. A first support structure 17 is attached to a side of the formwork wall 4 facing the first section, and a second support structure 18 with abutments 19 is attached to a side of the formwork wall 4 facing the second section. A tieback device 10 against the concrete pressure in the first section 1 has an end means 11 for anchoring to static reinforcement 9 or to the ground in the first section 1 and extends at the other end through the formwork wall 4 with a flexible tension element 12, which is longitudinally movable and supported on the side facing the second section.A clamping device 14, operable in the second section 2, is arranged between the abutment 19 and an end region 29 of the flexible tension element 12, by means of which the distance 100 between the abutment 19 and the end region 29 can be increased by spreading. The present invention further relates to a method for anchoring a formwork wall 4 and the use of an expanding clamping device 14.

Description

[0001] The invention relates to an expansion joint formwork for concrete construction according to the preamble of patent claim 1.

[0002] Concrete structures are typically constructed in sections, with joints forming between the successively cast sections. These are either construction joints, where the cast sections directly abut one another, possibly with the interposition of permanent formwork, or expansion joints, where a gap remains between adjacent cast sections that is filled with a deformable joint insert. Expansion joints are provided so that the cured cast sections can expand under the influence of heat or move relative to each other when forces are applied to the structure without causing damage to the concrete.

[0003] At the edge of a concreting section, a formwork with a formwork panel is arranged, which prevents the concrete from flowing out of the concreting section at the front. The still-flowing concrete exerts considerable hydrostatic pressure on the formwork panel. To prevent the formwork panel from being displaced during the pouring of the first concreting section, it is known to provide a tie-back device. This has at least one tension member, one end of which is connected to the formwork wall and the other end to the static reinforcement or a ground anchor on the side of the formwork wall facing the first concreting section. This creates a bracing of the formwork panel against the concrete pressure.

[0004] For permanent formwork for construction joints, it is known, for example, from EP 2 157 260 A1 or EP 2 192 237 A2, to use a rod-shaped tension strut as a tie-back tension member. One end of the rod-shaped tension strut penetrates the formwork panel and is secured there with a screw connection, while the other end is connected to the static reinforcement directly or via a suspension bracket or loop. Such tie-back devices are ideal for permanent stop-end formwork for construction joints. However, they are not suitable for creating expansion joints because an expansion joint must not be traversed by a rigid component to avoid impeding the mobility of the concrete sections in the joint.

[0005] The criterion that an expansion joint may not be traversed by a rigid component is ensured in the expansion joint formwork according to the generic DE 10 2016 217 430 A1 by the fact that the tie-back device crosses the formwork wall using a flexible tension element that does not significantly impede mobility in the expansion joint. This tension element, designed in particular as a cable loop, is suspended in the expansion joint formwork according to DE 10 2016 217 340 A1 on the side of the second section directly from the supporting structure there, which thereby forms the abutment for the tensile forces occurring in the tie-back device. To tension the tie-back device, the known expansion joint formwork features a tension rod integrated into the tie-back device, which can be adjusted longitudinally by means of a screw connection. This tension rod is located in the first section.The screw connection is difficult to access there, especially if several layers of static reinforcement are installed there.

[0006] The invention is based on the object of simplifying the handling of the expansion joint formwork.

[0007] This object is achieved by an expansion joint formwork for installation between a first section to be concreted first and a second section to be concreted afterwards in concrete construction for the purpose of forming an expansion joint between the sections, with a permanent formwork element which has a formwork wall containing a deformable separating joint insert between cover plates on both sides, wherein a first supporting structure is attached to the first section side of the formwork wall and a second supporting structure is attached to the second section side of the formwork wall, and with a back anchoring device against the concrete pressure in the first section,which has at one end means for anchoring to the static reinforcement or to the ground in the first section and at the other end passes through the formwork wall with a flexible tension element that can be moved longitudinally and is supported on the second section side on an abutment of the second supporting structure with its end region there in the direction from the second section to the formwork wall, characterized in that between the abutment and the end region a tensioning device that can be actuated in the second section is arranged, by means of which the distance between the abutment and the end region can be increased by spreading the flexible tension element,

[0008] In the expansion joint formwork according to the invention, the tensioning device for the tie-back anchoring device is located in the second section. There, it is easily accessible and simple to operate. This simplifies and accelerates the installation of the formwork.

[0009] Advantageously, the tensioning device comprises a set screw with a threaded shaft and screw head, which is rotatably supported on the abutment by the free end of the threaded shaft. A pull block is screwed to the threaded shaft, which can be coupled to the second-section end of the tension element in such a way that the end section is pulled into the second section by turning the set screw in the direction away from the formwork wall. This makes the set screw easily accessible in the second section and can be quickly and mechanically tightened, particularly with a cordless screwdriver.

[0010] The abutment can be an integral part of the second supporting structure, whereby the tensioning device is supported directly on the second supporting structure.

[0011] In particular, the abutment comprises a base plate attached to or supported by the second support structure and a sleeve projecting from the base plate in the direction of the second section, in which the free end of the threaded shaft can be rotatably received. This provides an easy-to-manufacture, reliable design for supporting the clamping device.

[0012] In particular, the drawing block comprises a perforated plate and a nut attached to it coaxially to the hole, which is screwed onto the threaded shaft. This allows for advantageous mounting of the flexible tension element on the perforated plate. Furthermore, the flat design saves space. The perforated plate extends, in particular, orthogonally to the threaded shaft.

[0013] In particular, the flexible tension element is a cable that wraps around the draw block with its second-section end section. Advantageously, the flexible tension element is a steel cable.

[0014] In particular, the perforated plate has slots open on the sides, into which the cable pull is accommodated. This allows the cable pull to be easily and securely connected to the tensioning device after passing through the formwork wall, namely by inserting it into the slots.

[0015] In particular, the cable pull forms a closed loop, the end of which, on the first section side, can be hooked into the end of a tension rod of the rear anchoring device opposite the anchoring means. This enables easy connection of the cable pull in the first section.

[0016] In particular, the length of the tension rod is variable. This allows the cable to be easily connected to the tension rod while tensioning it, and thus remains securely connected to the tension rod and the tensioning device, even before the tensioning device is tightened.

[0017] In particular, the cable pull consists of a double strand. This allows for a flexible cable pull that can still withstand high tensile forces.

[0018] Advantageously, each strand of the double strand has a diameter of 3 to 5 mm, preferably 4 mm. These are particularly advantageous dimensions for a steel cable with sufficient tensile strength.

[0019] In particular, the cable pull penetrates the formwork wall through holes whose diameter is larger than the cable pull diameter or the double strand diameter of the cable pull. Advantageously, the holes are at most twice the size of the cable pull diameter or the double strand diameter. This allows the cable pull to be easily guided through the holes, while also allowing the position of the cable pull to be well-defined even before tensioning. Furthermore, the penetration of concrete can be prevented.

[0020] In particular, the second supporting structure comprises a double stirrup whose stirrups are connected by the base plate of the abutment. Thus, the base plate also serves synergistically with the structure of the second supporting structure. In particular, the second supporting structure is designed so that static reinforcement of the second section can be attached to it.

[0021] Furthermore, a method for anchoring a formwork wall is described, in which a anchoring device is attached to a static reinforcement or to the ground in a first section. Before, simultaneously, or after this, a flexible tension element of the anchoring device is passed through a formwork wall that separates the first section from a second section. The flexible tension element is then tensioned in the second section. In particular, a tensioning device arranged in the second section is used for tensioning. The method can be carried out in particular on an expansion joint formwork as defined above.

[0022] Furthermore, a use of an expanding or spreading tensioning device for tensioning a back anchoring device for a formwork wall in concrete construction is described.

[0023] In the state of the art, however, anchorage devices are tensioned by contracting tensioning devices.

[0024] The invention is explained below using an exemplary embodiment. Figure 1 shows an embodiment of an expansion joint formwork according to the invention in plan view. Figure 2 shows an enlarged view of the clamping device. Figure 2a shows a detail from Figure 2 . Figure 3 shows the cut, AA from Figure 2 . Figure 4 shows the cut BB from Figure 2 . Figure 5 shows a side section view according to CC from Figure 1 . Figure 6 shows a side view according to DD from Figure 1 .

[0025] In Figure 1This shows a top view of an expansion joint formwork between a first section 1 (BA1) and a second section 2 (BA2). The first section 1 and the second section 2 are filled with concrete one after the other. The first section 1 and the second section 2 are separated from each other by a permanent formwork element 3, which has a formwork wall 4. The formwork wall 4 has a deformable separating joint insert 5 and cover plates 6 on both sides. This formwork wall 4 thus forms an expansion joint that can compensate for expansion and relative movements of the concrete parts.

[0026] The formwork element 3 is supported by a spacer 7 on a reusable formwork 8, which defines one or more concreting sections. The formwork 8 can, in particular, be a wooden formwork. In the concreting sections BA1, BA2, as shown in Figure 1For the first section 1, a static reinforcement 9 is provided. The static reinforcement 9 comprises, in particular, a grid of metal bars.

[0027] Furthermore, a tie-back device 10 is provided, which is suspended from the static reinforcement 9 via means 11 in the form of a cable loop. At the opposite end, the tie-back device 10 has a flexible tension element 12, which is guided through holes 13 in the formwork wall 4. In the illustrated embodiment, the flexible tension element 12 consists of a pair of cable strands that form a closed loop or double loop. The flexible tension element 12 extends to a tensioning device 14 arranged in the second section 2. In particular, the flexible tension element 12 is suspended in the tensioning device 14.

[0028] The anchoring device 7 has a two-part tension rod 15 arranged in the first section 1. The length of the tension rod 15 can be adjusted via a clamping mechanism 16. After the flexible tension element 12 has been secured in the tensioning device 14, a prestress can be applied to the flexible tension element 12 by shortening the tension rod 15. The tensioning device 14 is then expanded, i.e., the length of the tensioning device is increased, so that the flexible tension element 12 is pulled further into the second section 2. Thus, the formwork wall 4 is prestressed in the direction of the first section 1 and thus anchored against the concrete pressure during the subsequent filling of the first section 1 with concrete.

[0029] The formwork element 3 further comprises a first support structure 17 on the first section side, which is attached to the first section-side cover plate 6 via webs 30 and on which the static reinforcement 9 is supported. Furthermore, the formwork element 3 comprises a second support structure 18 on the second section side, which is attached to the second section-side cover plate 6 via webs 31.

[0030] The formwork wall 4 contains a joint tape 33 which is arranged in a cage 34 formed by the supporting structures 17, 18.

[0031] As described in more detail in Figure 2As shown, an abutment 19 is attached to the second support structure 18, which abutment has a base plate 20 and a sleeve 21 projecting from the base plate 20 in the direction of the second section 2. The clamping device 14 comprises an adjusting screw 22, which has a threaded shaft 23 and a screw head 24. An M16-200 screw is particularly suitable. As shown in the enlarged sectional view through the abutment 19 in Fig. 2a As shown, the end of the threaded shaft 23 facing the first section 1 is received in the sleeve 21 and can rotate freely therein. The free end of the threaded shaft 23 is supported in the sleeve 21 on the base plate 20 and there transfers the reaction force to the clamping force to the supporting structure 18 and thus to the formwork wall 4. The screw head 24 is arranged at the opposite end of the threaded shaft 23.

[0032] A pull block 25 is screwed onto the threaded shaft 23. The pull block 25 comprises a perforated plate 26 and a nut 27 attached thereto, through which the threaded shaft 23 extends. The flexible tension element 12 is suspended in the tension rod 15 in the first section 1. In the second section 2, an end region 29 of the flexible tension element 12 is suspended in the pull block 25 of the tensioning device 14. In particular, the flexible tension element 12 forms a closed loop that can be delivered already passed through the formwork wall 4.

[0033] After prestressing has been applied by shortening the tension rod 15 with the clamping mechanism 16, the screw head 24 is rotated using a screwing machine, thus moving the tension block 25 away from the first section 1, so that the distance 100 between the abutment 19 and the end region 29 of the flexible tension element 12 is increased. This fully tensions the anchoring device 10. The tension block 25 is initially secured manually against rotation. Alternatively, a mechanical anti-twist device can be provided for the tension block 25, for example, by a guide for the tension block attached to the second support structure 18. However, this is not necessary, since after prestressing has been applied, the anti-twist device is ensured by the flexible tension element 12.

[0034] In Figure 3It shows how the base plate 20 of the abutment 19 is attached to the second support structure 18. The support structure 18 here consists of a double bracket with intermediate spacing. The base plate 20 is welded to the struts of the second support structure 18 in a bridge-like manner. Furthermore, the arrangement of the threaded shaft 23 in the sleeve 21 is shown, as well as the eccentric guidance of the flexible tension element 12.

[0035] This eccentric leadership is particularly due to the Figure 4 shown perforated plate 26 of the drawing block 25. The flexible pulling element 12 is guided through slots 28 in the perforated plate 26, which enable eccentric mounting of the flexible pulling element 12 with respect to the threaded shaft 23.

[0036] In Figure 5The arrangement of two of the tensioning devices is shown one below the other on the formwork wall 4 in a side sectional view. The double cable strand of the flexible tension element 12 passes through the holes 13 in the formwork wall 4.

[0037] In Figure 6 The arrangement of the drawing block 25 of each of the clamping devices is shown, and how the flexible tension element 12 is accommodated in the slots 28 of the perforated plate 26. The end portion 29 of the flexible tension element 12 is guided around the threaded shaft 23, as also in Fig. 2 The strands of the double strand of the flexible tension element 12 are each guided past the threaded shaft 23 on opposite sides. The double strand is thus spread apart by the threaded shaft 23.

[0038] In one embodiment of the method according to the invention, in the device described above, the flexible tension element 12 is suspended in the tension rod 15, and then the adjusting screw 22 is rotated until the flexible tension element 12 is sufficiently tensioned to anchor the formwork wall 4 with respect to the first section 1. For this purpose, an expanding tensioning device 14 is used as shown.

[0039] The rough tension adjustment can be made on the variable-length tension rod 15 before its assembly. The final tension is applied by the tensioning device 14 according to the invention.

[0040] The invention is not limited to the embodiment described above.

[0041] The tension rod forming part of the tie-back device is known from DE 10 2017 216 383 A1. However, the tie-back device can be designed differently on the side of the first section, in particular as in the exemplary embodiments of DE 10 2016 217 430 A1. Instead of a double strand, a single strand can also be used for the flexible tension element 12, as long as its diameter, in order to ensure sufficient strength, does not have to be so large that it impairs mobility in the expansion joint. At very high stresses, more than two strands of approximately 4 mm diameter may be required. The base plate 20 of the abutment 19 does not have to be welded to the second supporting structure. It can also be folded and pushed onto the stirrup(s) of the second supporting structure 18 and pressed into place by the tension force.Instead of a welded nut 27, the pull block 25 itself can also be provided with a thread in its through hole. The cable pull of the flexible pull element 12 does not have to be loop-shaped. It can also be attached to the pull block 25 with one or more free ends, for example, by clamping screws, a clamping plate, or welding.

Claims

1. An expansion joint formwork for placing between a primary section (1) to be first concreted and a secondary section (2) to be concreted thereafter in concrete construction for forming an expansion joint between the sections (1, 2) comprising a permanent formwork element (3) having a formwork wall (4) including a deformable expansion joint (5) inserted between cover plates (6) on both sides, wherein on a primary section side of the formwork wall (4) a first support structure (17) and on a secondary section side of the formwork wall (4) a second support structure (18) having an abutment (19) are attached, respectively, and a bracing device (10) against the pressure of concrete in the primary section (1), wherein the bracing device (10) at one end includes means (11) for anchoring a static reinforcement (9) or at the bottom in the primary section (1) and at the other end of the formwork wall (4) is penetrated by a flexible tension member (12) so as to be longitudinally movable and is supported at the secondary section, characterized in that between the abutment (19) and an end portion (29) of the flexible tension member (12) a clamping device (14) operable in the secondary section (2) is interposed by means of which the distance (100) between the abutment (19) and the end portion (29) can be enlarged by spreading the flexible tension member.

2. The expansion joint formwork according to claim 1, characterized in that the clamping device (14) includes a setting screw (22) having a threaded shank (23) and a screw head (24) rotatably supported against the abutment (19) with the free end of the threaded shank (23), wherein the threaded shank thereof is screwed into a tensioning block (25) which can be coupled to the end portion (29) of the tension member (12) at the secondary section so that the end portion (29) is drawn away from the formwork wall (4) into the secondary section (2) by turning the setting screw (22).

3. The expansion joint formwork according to claims 1 and 2, characterized in that the abutment (19) includes a base plate (20) attached to the second support structure (18) or supported thereby and a sleeve (21) projecting therefrom towards the secondary section (2) into which the free end of the threaded shank (23) can be rotatably inserted.

4. The expansion joint formwork according at least to claim 2, characterized in that the tensioning block (25) comprises an apertured plate (26) and a nut (27) attached thereto coaxially to the aperture thereof and screwed onto the threaded shank (23).

5. The expansion joint formwork according at least to claim 2, characterized in that the flexible tension member (12) is a tensioning cable wrapped around the tensioning block (25) by its end portion (29) at the secondary section.

6. The expansion joint formwork according to claim 5, characterized in that the apertured plate (26) includes slots (28) opening sidewards into which the tensioning cable is inserted.

7. The expansion joint formwork according to claims 5 or 6, characterized in that the tensioning cable forms a closed loop, wherein the end portion thereof at the primary section can be hooked into the end of the tension rod (15) of the bracing device (10) opposite to the anchoring means (11).

8. The expansion joint formwork according to claim 7, characterized in that the length of the tension rod (15) is variable.

9. The expansion joint formwork according at least to claim 5, characterized in that the tensioning cable is made of a double-stranded cable.

10. The expansion joint formwork according to claim 9, characterized in that each strand of the double-stranded cable has a diameter of 3 to 5 mm, preferably 4 mm.

11. The expansion joint formwork according at least to any one of claims 5 to 10, characterized in that the tensioning cable penetrates the formwork wall (4) in holes (13) the diameter of which is larger than the diameter of the tensioning cable or the diameter of the double strands of the tensioning cable.

12. The expansion joint formwork according to any one of claims 1 to 11, characterized in that the second support structure (18) includes a double yoke, wherein the individual yokes thereof are connected to each other by the base plate (20) of the abutment (19).

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