EP0807728A2 - Formwork for making concrete columns - Google Patents

Abstract

The invention is directed to formwork for the production of round concrete columns. This consists of one or more formwork units (1), which are pressed together to form a dimensionally stable hollow body and sealed. The essential components are the wedges (7) of the formwork units (1), which are firmly connected to the joints (7) of the formwork units (3) and which are alternately offset in the longitudinal direction of the formwork, and a wedge-shaped clamp (2) which can be displaced in the longitudinal direction of the formwork the lugs (3) is guided, and presses both parts together, while the two lugs (3) are pressed against the inner surfaces (4) of the bracket (2) and thus assume a tangential position dependent on the diameter of the formwork and at the same time assume a firmly connected position Form a unit, the joint (7) of the formwork units (1) being covered by the shoulders (3) so that there is no direct connection from the inside to the outside.

Description

The invention relates to a formwork for the production of round concrete columns, wherein one or more formwork units are pressed together to form a rigid hollow body and sealed.

In the past, the production of round concrete columns was mostly carried out using wooden formwork consisting of individual slats, which were attached to wreaths and assembled in a complex process and secured against the high pressures. Another common process using round formwork parts made of sheet steel elements is for small quantities or uneconomical for special connecting structures. The use of one-way formwork for round concrete columns is particularly widespread, for example a sheet metal tube which is folded together from a spirally wound sheet metal strip. After removing the metal strip, an impression remains in the concrete, which can only be removed in a post-treatment by plastering or filling. Another common method is the so-called cardboard formwork, the use of which for large quantities is uneconomical and is therefore not responsible, especially from an ecological point of view.

According to the patent specification: AT 393 704 B Republic of Austria, a connection arrangement is described, two adjacent formwork elements, in particular a circular formwork, being connected to one another in such a way that both parts are butted against one another without overlap and without folds, and are held together by the connection elements will. With the large pressure development that occurs at the joints of the formwork during concreting, the formwork elements are deformed between the connecting elements, so that joints are created through which the concrete can escape. In addition, the two formwork elements are not continuously secured against displacement due to the lack of toothing, so that they behave unstably, with the result that the two formwork elements yield in an uneven manner. Another disadvantage is. that the connection arrangement can be moved continuously like a hinge to one side and is therefore unstable. As a result, in addition to the joints already mentioned, bumps on the joint also occur.

task

The formwork according to the invention has the task of eliminating the aforementioned deficiencies, the formwork units (1) being connected and sealed to one another in a simple manner to form a dimensionally stable hollow body. This object is achieved by the features listed in patent claims 1 and 2.

The essential components are several wedge-shaped lugs (3) that belong together in pairs and are firmly connected to the abutting formwork units (1), which are mirror-symmetrically shaped and complement each other complementary to one another, but to the adjacent lugs (3) that belong together above and below. are horizontally offset. This results in a continuous toothing (15) in the longitudinal direction of the formwork, both formwork parts being anchored in a zipper-like manner and, after the two abutting edges have been pressed together, displacement, twisting, kinking or tearing of the anchoring is not possible. In special cases, however, this horizontal displacement of the lugs (3) can be dispensed with.

After the paired lugs (3) are pressed against the inside (4) of the cranked bracket (2), they are in a position without tension so that together with the subsequent formwork elements (1) they form an exact circular line (5) in cross section, so run tangential. The dimensioning of the offset (10) of the clamp (2) is dependent on the diameter of the formwork, the offset (10) of the clamp (2) becoming flatter as the diameter of the formwork increases. According to the invention, the two sides therefore connect to form a firmly connected unit with a predetermined shape based on the formwork diameter. The three mutually separate joints (7), consisting of the inner joint (7) of the formwork units (1), the circular surface (6) offset by 90 ° and the outer joint (7), in turn offset by 90 °, between the two approaches ( 3) result in a high degree of tightness in addition to the anchoring, since the connection from the inside to the outside is prevented by changing the direction three times. This is one of the most important criteria of the formwork according to the invention.

The two wedge-shaped lugs (3) belonging together and arranged in pairs serve as guides (8) for the clamp (2) and are held together by them in pairs. In order to ensure that the bracket (2), which can be moved in the longitudinal direction of the column, has a firm hold on the two lugs (3), it is necessary that the two legs (13) of the bracket (2) and the two lugs (3) which are tapered at an acute angle (11). The central offset (10) of the clip (2) is of crucial importance. This must be dimensioned and shaped so that the two inner surfaces (4) of the bracket (2) are tangential to the circular line (5) of the formwork unit (1).

After the paired lugs (3) on the inner surfaces (4) of the bracket (2) are pressed tangentially, it is ensured that the two subsequent formwork units (1) also connect tangentially and stress-free to both lugs (3) and an exact circular line ( 5) form. The two pairs of approaches (3) are not only pressed together by the clip (2), but at the same time they are pressed onto the inner surfaces (4) of the cranked clip (2) and brought into the position assigned to the respective formwork diameter. A rod (9) welded onto the crank (10) is used for assembly in order to be able to strike the clamp (2) downwards or upwards. The angle (11) of the wedge-shaped bracket (2) is identical to the angle (11) of the wedge-shaped lugs (3), so that when the bracket (2) is moved longitudinally, the entire length of the two legs (13) always lies. The angle (11) of the two opposite lugs (3) is dimensioned such that the clamp (2) can be placed or removed in the de-energized state, but receives the guide (8) in the event of longitudinal displacement and is under tension. Since the vertical toothing (15) makes it impossible to move to either side, the paired approaches (3) are always exactly in position as a mirror image of one another. It is thus ensured that the joint (7) of the formwork units (1) is alternately but continuously covered over the entire height of the formwork by the shoulders (3), which causes the formwork to be watertight.

Fig.1

zeigt eine Ansicht mit aufgeschobenen Klammern (2).

Fig.2

zeigt eine Ansicht der Schalung im losen Zustand ohne Klammern (2).

Fig.3

zeigt einen Querschnitt der Schalung im Bereich der Ansätze (3) mit aufgeschobener Klammer (2).

Fig.4

zeigt den Querschnitt der Schalung im Bereich der Ansätze (3) mit aufgeschobener Klammer (2), wobei die Schalungseinheiten (1) mit einer U-Schiene (14) eingefaßt sind.

Fig.5

zeigt eine Ansicht des in Fig.4 dargestellten Querschnitts der U-Schienen (14) und Ansätze (3) mit aufgeschobener Klammer (2).

Fig.6

zeigt eine Klammer im Querschnitt.

Fig.7

zeigt eine perspektivische Darstellung der Klammer (2).

Fig.8

zeigt eine perspektivische Darstellung einer Manschette (18) im geöffneten Zustand.

The formwork according to the invention is shown in the drawings and described in more detail below.

Fig. 1

shows a view with brackets pushed on (2).

Fig. 2

shows a view of the formwork in the loose state without brackets (2).

Fig. 3

shows a cross section of the formwork in the area of the approaches (3) with the clamp (2) pushed on.

Fig. 4

shows the cross-section of the formwork in the area of the approaches (3) with the clamp (2) pushed on, the formwork units (1) being edged with a U-rail (14).

Fig. 5

shows a view of the cross section shown in Figure 4 of the U-rails (14) and lugs (3) with the clamp (2) pushed on.

Fig. 6

shows a bracket in cross section.

Fig. 7

shows a perspective view of the clip (2).

Fig. 8

shows a perspective view of a cuff (18) in the open state.

The formwork according to the invention is assembled in such a way that when the formwork units (1) are joined together, the lugs (3) are necessarily in the correct position, the clamps (2) can be pushed onto the lugs (3), and by longitudinal displacement downwards Tension. When loosening the formwork, the clamps (2) are pushed back upwards and removed so that the formwork can be disassembled without tension.

In the case of a formwork extension, the pipe ends or formwork parts to be connected are covered with a sleeve (18) which is secured against vertical displacement by bases (19), these parts with lugs (3) and brackets (2) or with screws or with another Jig are held together, and can be equipped with tabs for fastening the formwork support. In order to optimize the stability, a sleeve (18) can be attached at any point on the formwork.

Instead of sheet steel, another material, for example fiberglass, wood fiber cardboard, etc., can be used for the formwork units (1). Sheet steel can be riveted and glued or welded, whereas if another material is used for the formwork units (1), it is necessary for them to be edged and glued to the joints (7). For this purpose, U-rails are provided, on the legs of which the lugs (3) are welded. The formwork units (1) are pressed into the U-profile using adhesive. It is advisable to cover the inside of the formwork units (1), since on the one hand the material thickness of the U-rails (14) is compensated for, and on the other hand the concrete does not come into contact with the formwork units (1), especially if it does is an absorbent or rough material such as wood fiber cardboard.

In addition to the production of cylindrical columns, the formwork can also be used in the same way for the production of conical round columns, conical column bases or conical column heads (coves). Any other use as a silo, round container, round duct or sheet metal cladding is also possible.

Claims (9)

Formwork for the production of round concrete columns, consisting of a round column formwork composed of one or more parts from formwork units (1), wedge-shaped approaches (3) arranged in pairs in mirror-image fashion on the joints (7) of the formwork units (1) running in the longitudinal direction of the formwork. are fastened, the continuous (7) joint of the formwork units (1) extending in the longitudinal direction of the formwork being covered by the shoulders (3), the circular surface (6) offset by 90 ° with respect to the joint surface (7) and the outer joint ( 7) of the two lugs (3) abut each other and the two lugs (3) arranged in pairs taper and undercut on the outside at an acute angle (11) and are identical in shape to the inside of the two legs (13) of the clamp (2) and serve as a guide (8) for a cranked bracket (2), which the pairwise Ans when moving in the longitudinal direction of the formwork tze (3) presses and at the same time presses against the inner surfaces (4) of the clamp (2), so that the two lugs (3) are necessarily in a tangential position to the circular line (5) of the formwork surface due to the offset (10) of the clamp (2) take in. Formwork according to claim 1, characterized in that the lugs (3) arranged in pairs are offset alternately horizontally and thus form a continuous toothing (15) in the longitudinal direction of the formwork. Formwork according to claim 1, characterized in that the lugs (3) arranged in pairs are only partially or in any number horizontally offset or that the lugs (3) arranged in pairs are not horizontally offset. Formwork according to one of claims 1 to 3, characterized in that, in the case of a formwork extension, the pipe ends or formwork parts to be connected are covered with a sleeve (18) which is secured by bases (19) against displacements in the longitudinal direction of the formwork, these parts with Lugs (3) and brackets (2) or with screws or with another clamping device can be held together and can also be used for fastening the formwork struts. Formwork according to one of Claims 1 to 4, characterized in that, in addition to round formwork units (1), those with a flat surface are also connected, the clamp (2) receiving no offset (10). Formwork according to one of claims 1 to 4, characterized in that it can be used for conical round columns, conical round column feet and conical round column heads (coves) in addition to cylindrical columns. Formwork according to one of claims 1 to 4, characterized in that it is used instead of as concrete formwork for another purpose, for example as a silo or round container of various kinds or for air shafts and round sheet metal cladding. Formwork according to one of claims 1 to 7, characterized in that the formwork units (1), the lugs (3) and the brackets (2) are made of steel, stainless steel or of another material with or without a coating. Formwork according to one of claims 1 to 8, characterized in that the joints (7) of the formwork units (1) are framed with U-rails or with another profile and the lugs (3) are fastened thereon.

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