EP1272718B9 - Round formwork module - Google Patents

Abstract

A round formwork module comprising a flexible skin having a front side which, when used, constitutes the forming surface for a concrete structure which is to be cast, and also provided with a rear side and a supporting structure which is arranged on the rear side of the skin and which can be displaced in order to enable the skin to be bent along a direction in which it extends. The invention is characterized in that the supporting structure has a base structure and two side elements which are arranged laterally, close to the base structure. The side elements are respectively secured to a lateral edge area of the skin and protrude therefrom close to the base structure. An adjustment device for adjusting the curvature is provided in between the base structure and the side elements.

Description

The present invention relates to a circular formwork module comprising a flexible formwork skin with a front side, which in use forms the shaping surface for the concrete structure to be cast, and with a rear side, and a support structure, which is arranged on the rear side of the formwork skin and is adjustable to curl allow the formwork along a direction of extension of the formwork skin.

Such circular formworks are known from various Schalungsanbietem and, for example, in DE 89 08 345 U1 and DE 41 16 439 C1 described. With them, for example, circular but also other curved structures can be cast from concrete. A typical example are round walls around spiral staircases or circular clarifiers. A circular formwork for such walls typically has an inner formwork and an outer formwork. Both are made up of several individual circular formwork modules. Known circular formwork systems have the disadvantage that they are formed from many different components that must be assembled at the construction site complicated. This requires extensive storage and has a complex construction on the site result. Another disadvantage is that the curvature of individual circular formwork modules is sometimes difficult to adjust before assembly In particular, often the two lateral edge portions of a circular formwork module in the direction of curvature, with which a circular formwork module connects to the next round formwork module, not aligned correctly, which in addition to the assembly the construction site difficult. The reason for this lies in the static indeterminacy of all these constructions. Thus, the Veriagerungsschranken for the lateral edge regions at its two end portions are hingedly connected to the support structure or the formwork skin, additionally difficult to assemble on the construction site. The reason for this lies in the static indeterminacy of all these constructions. Thus, the displacement screws for the lateral edge regions are connected at their two end regions in an articulated manner to the support structure or the formlining, which makes a defined positioning of these edge regions more difficult by means of these displacement barriers. Simply fixing two adjacent circular formwork modules together will not solve this problem. To solve this problem, a further displacement screw is provided between two adjoining circular formwork modules, by means of which the fine positioning takes place. Accordingly, in some systems, it is only possible to correctly set the curvature of the lateral edge regions when the circular formwork module is connected to the circumferentially closest circular formwork module. In this case, the merging edge areas of two round formwork modules must be adjusted correctly in their curvature, and it is obvious that this makes construction particularly difficult. In addition, at least in a part of these systems, this edge region is statically indefinite according to the known criteria for trusses, so that the curvature in this area can not be adjusted together at least before the assembly of several round formwork modules. In this case, the joint between two circular formwork modules, ie the area where two circular formwork modules abut one another, is of particularly great importance for a good quality of the formwork and according to the wall cast with this formwork. Optimally, the abutting surfaces are exactly radial, ie perpendicular to the tangent to the concrete wall to be cast in the region of the joint. Only this allows a correct connection of two round formwork modules. If this requirement is not met, then either between the two circular formwork modules on a gap in which concrete can flow during casting, or the formwork skins of the two circular formwork modules do not close smoothly to each other, ie it forms in the finished structure made of concrete a kink at this point.

From the DE 38 41 579 A1 is a formwork for large-format curved prefabricated reinforced concrete known. The formwork illustrated in the exemplary embodiment of FIG. 8 comprises a basic framework, torsionally rigid support beams connected rigidly to the formwork skin and, in turn, rigidly connected lever arms. There are adjusting provided, which are hingedly connected to the skeleton and articulated on the lever arm.

Object of the present invention is to provide a circular formwork module or a circular formwork, in which the abutment surfaces in the curved state are always correctly directed radially to the center of the circle whose radius is set in the circular formwork module, with little effort on the site to a Round formwork can be assembled from several circular formwork modules, and that is well stackable.

According to the invention, this object is achieved by a circular formwork module according to claim 1.

Thus, the invention differs from DE 8908345 U1 and DE 4116439 C1 on the one hand by the fact that a stable base structure is present. In contrast, shows DE 4116439 C1 a support structure with a plurality of joints and a plurality of displacement screws. Similar shows DE 8908345 U1 , Furthermore, according to the invention side elements are present, which are each attached to the lateral edge region of the formwork skin and protrude from there into the vicinity of the base structure. This "console" shifts the fulcrum of the displacement segment away from the lateral edge region to the base structure. It also makes it possible, in the vicinity of the base structure, to provide only a fulcrum on the displacement element about which the side elements with the formwork skin are displaced.

After this solution according to the invention, the flexible formwork skin is attached to the two lateral edge regions on the support structure and can move substantially freely therebetween. The two side elements can be moved like a wing relative to the base structure. The formliner assumes a state in between, in which the tensions in it are distributed as evenly as possible, which corresponds to a fairly good approximation of the circular shape. An appropriate choice of geometries ensures that the lateral abutment surfaces of the circular formwork module, i. H. the surfaces on which abuts a round formwork module to the circumferentially adjacent circular formwork module, in this construction always extend radially to the corresponding circle center. This allows a simple construction of a corresponding circular formwork. The circular formwork modules are set to the correct radius before assembly, whereby the correct course of the abutment surface inevitably results radially to the center of the circle. The preset circular form modules are then joined together at their abutment surfaces without the need for further correction of the radius of curvature

As with the prior art circular formwork systems, there are different circular formwork modules for the inside of a bend and for the outside of a bend. The outer-side circular formwork modules are generally only curved concavely, while the inner side Rundschalungsmodule generally only convex curved. In order to keep the distance between the round formwork modules of the inside and the outside constant, conventional clamping elements for interconnecting the inner formwork and outer formwork circular formwork modules are provided. Conveniently, these clamping elements engage the base structure of the support structure.

The direction of curvature, ie the direction of extension of the formwork along which the formwork curve curves, corresponds to the circumferential direction of the circle in the case of a plurality of circular formwork modules which are combined to form a circle. Conveniently, the formwork is attached to the base structure, for example, to ensure that in outer formwork circular formwork modules, the formwork always concave curves. The attachment of the formwork skin is advantageously carried out substantially on a line which is transverse to the direction of curvature. It is particularly favorable, the attachment of the formwork to the base structure in such a way that a certain mobility of the formwork skin is relative to the base structure in the direction of curvature. This is particularly advantageous if an attachment of the formwork to the base structure is provided along more than one line provided at right angles to the direction of curvature.

Due to the design of the circular formwork module with the special support structure which is firmly connected to the formwork, a relatively flat structure of the circular formwork module can be realized, so that in the radial direction a round formwork module has a thickness of about 12 cm compared with about 40 cm in the prior art , The favorable effect of this flat construction on the stackability (small space requirement) of the circular formwork modules is obvious. Another advantage is that the support structure can be relatively easily designed so that the back, d. H. the forming surface of the formwork facing opposite side of the circular formwork module, extending substantially in one plane, whereby the stackability is further improved.

The support structure can also be constructed very stable. This can be additional Verstärkungsklammem, which are additionally applied in the prior art from the outside as another support layer, bypass. The associated lower number of required components has a positive impact on the overall cost of the system.

The adjusting device is an adjusting screw. Such adjusting screws can be relatively easily adjusted with a simple tool on the construction site, they are easy to handle and reliably prevent unintentional adjustment.

The adjusting screw is rigidly connected to the base member and hinged to the side member or vice versa. The one-sided rigid attachment has the advantage of a simple and inexpensive production. In addition, a lateral buckling of the otherwise "soft" with the formwork attached to the base structure side member is reliably prevented by this statically determined structure.

Preferably, the base structure has at least two carriers which extend transversely to the direction of curvature and to which the formwork skin is attached. As already described, a fastening, for example with screws, which are displaceable in extending in the direction of curvature elongated holes provided. This enables a secure tension compensation via the formwork of a circular formwork module when bending. It is also possible to provide only one central support. It can also be provided more than two carriers. Then it is favorable if at least a part of these carriers is movable relative to another part of these carriers.

Preferably, the base structure has two carriers transversely to the direction of curvature, which are connected to at least two sub-carriers to form a framework. This construction is very stable, which allows a flat design of the circular formwork modules. In addition, this framework can be stiffened by a diagonal.

Preferably, the base structure has a plurality of frameworks with two interconnected supports, which are interconnected via an intermediate element. In this way, significantly longer frame formwork modules can be realized in the direction of curvature, which is particularly favorable for large round formworks.

Vorzugswseise, the intermediate member has an elongated central support which is mounted centrally between the frame structures and transverse to the direction of curvature on the formwork and projecting from the lateral arms in the vicinity of the framework, wherein between the arms of the intermediate member and the frame Vestellvorrichtungen for adjusting the curvature are provided. This construction allows a relative pivoting of the two frameworks against each other to realize over this entire long circular formwork module a uniform curvature of the flexible formwork skin. The formwork skin is again preferably fastened to the elongated central support. With the laterally projecting arms away from the central support, this intermediate element is substantially constructed as if two side elements of a circular form module were connected together along the abutment surface.

Preferably, the circular formwork module is designed in the manner of a frame formwork. Frame formwork is often used in the usual flat formwork used to form flat concrete surfaces. Such frame formwork have a frame as a scaffold. The formwork is attached to this frame. Two adjacent frame formwork elements are commonly connected with brackets, called frame locks. These frame locks clamp the two adjoining each other on their abutting surface frame together, they align each other so that the two Schalhäute are on the forming side of the formwork in substantially the same plane, and clamp the formwork modules together. An alternative to the frame formwork are the so-called carrier formwork, in which the formwork is attached to the secondary beams. The secondary beams are connected to main beams and supported by these. For circular formwork, only carrier formwork has hitherto been used. The experts have assumed that the principle of frame formwork for circular formworks is not applicable. Therefore, the feature that the circular formwork module is a formwork module based on the principle of frame formwork is considered to be inventive in its own right, ie independently of whether it is provided in conjunction with one or more other features of the circular formwork modules described herein; In particular, the simultaneous realization of the features of claim 1 is not necessary.

Preferably, the circular formwork module is formed with an interrupted frame, wherein the side elements form first frame parts for connection to laterally adjacent in the use round formwork modules and second frame parts are provided for connection to vertically adjacent in the insert formwork modules. The connection laterally and vertically above or below Rundschalungsmodule can then be made in accordance with as in panel formwork for flat concrete surfaces.

Preferably, the frame parts are folded sheet metal shaped parts. These are particularly easy to manufacture, inexpensive in price, stable and lightweight.

Preferably, the frame parts have in cross-section to the frame inside out open longitudinally extending recess into which the frame locks can intervene in the use of each other for connecting two round formwork modules.

Preferably, the formwork skin is reinforced between the base structure and the side elements.

This reinforcement is preferably made with a steel band. The steel strip is attached substantially to the side member and the side member of the support structure. It is also possible to attach the steel strip to the formwork directly. Then it is cheap, the steel strip over the entire length of the circular formwork module in the direction of curvature provided consistently.

The invention further relates to a frame formwork which has at least one round formwork module designed as a frame formwork module according to one of claims 1 to 12.

Fig. 1

ein inneres und ein äußeres Rundschalungsmodul im gekrümmten Zustand;

Fig. 2

ein Abschnitt einer Rundschalung mit erfindungsgemäßen Rundschalungsmodulen;

Fig. 3

eine rückseitige Ansicht eines erfindungsgemäßen Rundschalungsmoduls;

Fig. 4

ein erfindungsgemäßes Rundschalungsmodul im ungekrümmten Zustand; und

Fig. 5

eine andere Ausführungsform eines erfindungsgemäßen Rundschalungsmoduls.

The invention will be explained in more detail with reference to a drawing illustrated embodiment. Show it:

Fig. 1

an inner and an outer circular form module in the curved state;

Fig. 2

a section of a circular formwork with round formwork modules according to the invention;

Fig. 3

a rear view of a circular formwork module according to the invention;

Fig. 4

an inventive circular formwork module in the non-curved state; and

Fig. 5

another embodiment of a circular formwork module according to the invention.

In Fig. 1 an inner formwork and an outer formwork circular formwork module 2 are shown, which are both constructed substantially the same. The following description will refer essentially to the outer formwork circular formwork module 2. There one recognizes a flexible formwork skin 4, which has a front side 6, which forms the shaping surface for the concrete structure to be cast. It also recognizes a back 8 of the formwork 4, which is opposite to the front 6. The circular formwork module 2 also has a support structure 10, which is arranged on the rear side 8 of the formwork skin 4. The support structure 10 is adjustable by means of two adjusting devices 12 to the curvature of Formwork skin 4 along a direction of extension of the formwork 4 to allow.

It can be seen that the support structure 10 has a base structure 14 and two side elements 16, which are arranged laterally next to the base structure 14 in the direction of curvature. The side members 16 are each attached to a lateral edge region 18 of the formwork skin 4 and have arms 20 which project into the vicinity of the base structure 14. Between the base structure 14 and each of the arms 20 of the side members 16 is provided an adjusting device 12 for adjusting the curvature.

It can be seen that the adjusting device 12 is essentially made up of three parts: a threaded projection 22 which is fixed, i. without hinge, is secured to the base structure 14, a threaded lug 24 hinged to the arm 20 of the side member 16, and a nut 26 cooperating with the two threaded ends of the threaded lugs 22 and 24. The threads of the threaded lugs 22 and 24 are opposite to each other, i. Left-hand thread and right-hand thread such that rotation of the nut 26 in one direction forces the arm 20 of the side member 16 away from the base structure 14, and turning in the other direction draws the arm 20 of the side member 16 toward the base structure 14. It can also be seen that the two circular formwork modules with a clamping anchor 28 and corresponding anchor plates 30 are clamped together. Tensioning anchor 28 and anchor plates 30 preferably each have threads with which they cooperate. This ensures the distance between the two circular formwork modules to each other.

It can also be seen that the base structure 14 has two supports 32 transversely to the direction of curvature, to which the formwork skin 4 is attached. The Base structure 14 additionally has two secondary supports 34, which connect the two supports 32 to one another and support one another. The two carriers 32 form with the two sub-carriers 34 a frame scaffold 38. In the Fig. 1 can also be seen a steel strip 40, with which the side member 16 is connected to the base structure 14.

The formlining 4 is, for example, multi-layered wood panels glued together. Such material provides sufficient strength required for the intended application. In addition, it has sufficient flexibility to allow the panels to curve to the desired radius, for example, up to a radius of 8 meters, 4 meters or even smaller. Other materials such as plastic materials are also conceivable.

Fig. 2 shows a part of a circular formwork consisting of two outer formwork circular formwork modules 2 and two inner formwork circular formwork modules 2, which are connected to each other at the connection region with different frame locks 42. It can be seen that the circular formwork modules are constructed on the principle of the frame formwork, in which a plurality of frame formwork elements are connected to each other at the corresponding frame members with frame locks 42. It can be seen in the figure how the gripping elements 44 of the frame locks engage in recesses 48 of the frame parts which are open toward the frame inside and thus clamp circumferentially adjacent round formwork modules 2 against each other. By a suitable choice of the shape of the gripping elements 44 and the recess 48, the circular formwork modules 2 are aligned in this way to each other correctly. In similar Way, the connection of vertically superimposed circular formwork modules 2 works together. At the point where the two inner formwork circular formwork modules 2 are connected to each other, one recognizes a spacer 50 which is set with substantially parallel surfaces between the abutting surfaces of the two circular formwork modules. Since the circular formwork modules have a predetermined length in the direction of curvature, the spacers 50 are required to construct circular formations with radii leading to circumferential lengths which are not integer multiples of a length of a circular form module 2. Spacers 50 can be used both in internal formwork circular formwork and in external formwork circular formwork. In general, spacers of the same thickness are used at each connection point between circular formwork modules 2 of a circular formwork.

Fig. 3 shows a rear view of a circular formwork module 2, in which one can recognize the structure of the support structure 10 particularly well. Thus, one recognizes again the base structure 14 and the two side elements 16, which are arranged laterally next to the base structure 14 in the direction of curvature. It can be seen two carriers 32 of the base structure 14, which extend transversely to the direction of curvature, and two secondary beams 34, with which the two carriers 32 are connected to a frame structure 38. Furthermore, two second frame parts 36 can be seen at the upper or lower connection point to vertically above or below further circular formwork modules 2. First frame parts 46 are fixedly connected to the edge region 18 of the formwork skin 4 and are part of the side elements 16 the arms 20 of the side members 16 projecting towards the base part 14 are connected.

Thus, the first frame parts 46 and the second frame parts 36 form a frame for the circular formwork module 2, which substantially corresponds to the frame of flat, flat formwork modules. In order to ensure the curvature capability of the circular formwork modules 2, only the first frame parts 46 are not attached to the second frame parts 36.

It should be noted that the secondary beams 34 and the second frame members 36 are desirably mounted so as not to substantially collide with the formwork skin 4 during curving of the frame formwork modules 2. So one recognizes in the Fig. 1 in that the secondary supports 34 are set back from the formwork skin 4 with respect to the support 32 in order to ensure this mobility.

In the Fig. 3 can be seen in the sub-carriers 34 has an opening 52 through which the clamping anchor 28 can be performed. It can also be seen in plan view under the arms 20 of the side members 16, the steel strip 40th

In the Fig. 4 is a circular formwork module 2 shown in the unbent state. It can be seen that the adjusting screw 12 is arranged substantially parallel to the formwork skin 4. Turning the nut 26 of the adjusting screw 12, a force is applied to the pivot point 54. Because of the distance of the pivot point 54 to the flexible formwork skin 4, or the steel strip 40, this force generates a moment on the formwork 4, which is applied over the edge region 18 of the formwork 4 on the formwork 4 and this depending on the direction of the force either in a convex or a concave direction moves. When moving in the convex direction, ie use of the circular formwork module as inner formwork circular formwork module, the formwork skin 4 must the support 32 not be attached. It is sufficient if the carriers 32 form abutments for the formwork skin 4.

The length ratio abutting surface of one side element 16 to first pivot point 54 / first pivot point 54 to second pivot point 54 / second pivot point 54 to abutment surface of the other side member 16 is substantially a / 2a / a. More specifically, the length of the first pivot 54 to the second pivot 54 is slightly greater than 2a. To determine the position of the fulcrum geometric considerations must be made. In this case, the circle segment, which is formed by the formwork skin 4, approximated by a polygon, which consists of three straight lines whose lengths are in relation to each other in the ratio a / 2a / a. The geometric positions of the attachment points of the formwork 4 to the supports 32 and the position of the pivot point 54 are then chosen so that these lengths a / 2a / a are obtained.

About the formwork is a substantially uniform stress distribution, which means that it assumes the shape of a circle segment substantially. Since the force engagement is performed on the formwork 4 over the edge regions 18 of the formwork 4, this circular segment shape over the entire length of the formwork 4 a. Thus, automatically the lateral abutment surface of the side member 16 and the first frame part 46 is basically substantially radially to the center of curvature.

To ensure that at a curvature in the concave direction, the formwork 4 remains in contact with the carrier 32, it is necessary to set the formwork skin 4 on the supports 32. It is convenient to make this determination so that a mobility in the direction of curvature preserved. For example, screws which are screwed into the formwork skin 4 or other fastening elements which are displaceable in longitudinal direction in the direction of curvature on the supports 32 can be imagined.

Fig. 5 shows an alternative embodiment of a circular formwork module 2, in which two frame scaffoldings 38 are interconnected via an intermediate element 56. Laterally outside this combination of the two frame structures 38 and the intermediate element 56 is again a respective side member 16 for connection to adjacent circular formwork modules. 2

The intermediate element 56 has an elongated central support 58, which is connected to the formwork skin 4. The central support 58 is located approximately midway between the frame structures 38 and extends in the same direction as the supports 32 of the frameworks 38. Lateral arms 60 are attached to the central support 58 and project into the vicinity of the frameworks 38. Adjusting devices 12 for adjusting the curvature are provided between the arms 60 of the intermediate element 56 and the frame frameworks 38.

More than with the "short" circular formwork modules 2 of the Fig. 1 to 4 it comes with the "long" round formwork module 2 of Fig. 5 to adjust all adjustment 12 correctly to get the right radius. On the one hand, a correct setting can be achieved by placing the individual circular formwork modules 2 on a template having the required radius and adjusting on this template until the formwork skin 4 agrees well with the shape of the template. Alternatively, you can imagine the angular positions between the side members 16 and the base structure 14 and between the side members 16 and the frame structures 38 and between the frame structures 38 and the arms of the intermediate member 56 as a measure of the correct adjustment of the radius. Once these angles have been determined, the desired radius can be set reproducibly in this way. It can be imagined, for example, at the ends of the arms 20, or 60 in the adjustment of a scale 62 (s. Fig. 1 ) with which the correct angle setting and thus the correct radius can be selected.

In the embodiment shown, the essential parts of the support structure sheet metal parts, for example made of sheet steel, which are favorably treated with corrosion protection. However, those skilled in the art will recognize that other materials, such as extruded aluminum, may be used.

Claims (12)

1. A round formwork module (2) having a flexible skin (4) with a front (6) forming in use the shaping surface for the concrete structure to be cast, and a back (8), and a support structure (10) that is disposed on the back (8) of the skin (4) and adjustable to permit curvature of the skin (4) along a direction of extension of the skin (4), the support structure (10) having a base structure (14) and two side elements (16) disposed laterally beside the base structure (14) in the direction of curvature, the side elements (16) each being fastened to a lateral edge area (18) of the skin (4), and an adjusting apparatus (12) being provided between the base structure (14) and each of the side elements (16) for adjusting the curvature, and the side elements (16) extending away from the lateral edge area (18) into the proximity of the base structure (14),
   characterized in that the adjusting apparatus (12) is an adjusting screw (12), with the adjusting screw (22) being connected rigidly to the base structure (14) and connected flexibly to the side element (16) or vice versa.
2. A round formwork module (2) according to claim 1,
   characterized in that the adjusting screw (12) is connected rigidly to the base element (14).
3. A round formwork module (2) according to claim 1 or 2,
   characterized in that the base structure (14) has at least two beams (32) at right angles to the direction of curvature to which the skin (4) is fastened.
4. A round formwork module (2) according to any of claims 1 to 3,
   characterized in that the base structure (14) has two beams (32) at right angles to the direction of curvature that are connected with at least two secondary beams (34; 36) to form a frame scaffold (38).
5. A round formwork module (2) according to claim 4,
   characterized in that the base structure (14) has a plurality of frame scaffolds (38) with two interconnected beams (32) that are interconnected via an intermediate element (56).
6. A round formwork module (2) according to claim 5,
   characterized in that the intermediate element (56) has an elongate central beam (58) fastened to the skin (4) in the middle between the frame scaffolds (38) and at right angles to the direction of curvature and from which lateral arms (60) protrude into the proximity of the frame scaffolds (38), with adjusting apparatuses (12) being provided between the arms (60) of the intermediate element (56) and the frame scaffolds (38) for adjusting the curvature.
7. A round formwork module (2) according to any of claims 1 to 6,
   characterized in that it is designed as a frame formwork module, the side elements (18) forming first frame parts (46) for connection with round formwork modules (2) laterally adjacent in use, and second frame parts (36) are provided for connection with round formwork modules (2) vertically adjacent in use.
8. A round formwork module (2) according to claim 7,
   characterized in that the frame parts (36, 46) are folded sheet-metal shaped parts.
9. A round formwork module (2) according to claim 7 or 8,
   characterized in that the frame parts (36) have in cross section a depression (48) open toward the inside of the frame for the frame couplers (42) to engage in use for interconnecting two round formwork modules (2) each.
10. A round formwork module (2) according to any of claims 1 to 9,
    characterized in that the skin (4) is reinforced between the base structure (14) and the side elements (16).
11. A round formwork module (2) according to claim 10 that is in the form of a frame formwork module,
    characterized in that the skin (4) is reinforced with a steel band (40).
12. A frame formwork comprising at least one round formwork module (2) according to any of claims 1 to 11 in the form of a frame formwork module.

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