EP1486628B1 - Truss - Google Patents

Abstract

During the off-site fabrication of building components, concrete panels are cast in a mold with a steel wire reinforcement frame. The frame consists of two parallel base wires (11) separated by a distance, and two top parallel wires (22) separated by a lesser distance. The top and bottom wires (11, 22) are linked by a zigzag wire (32) that is sandwiched and spot-welded at the top, and spot welded to alternating sides at the bottom. The zigzag is at a pitch interval d and angle alpha.

Description

The present invention relates to a lattice girder, and more particularly to a girder for use in prefabricated walls and ceilings.

Lattice girders have long been known as reinforcing elements in reinforced concrete construction. By way of example, reference is made to the lattice girder KT 600 of Kaiser-Omnia Bausysteme GmbH & Co., Frankfurt and DE 81 15 872 U1 of the same company.

Examples of the use of such lattice girders are described in Betonwerk + Fertigteil-Technik (BFT), Issue 12/99, Bauverlag GmbH, Am Klingenweg 4a, 65396 Walluf.

From FR 1 374 389 A a lattice girder is known which consists of three lower chords, a single upper chord, a strut snake, and cross struts. The three lower chords are arranged parallel to one another at intervals from one another in a plane and welded to the transverse struts which are perpendicular to the lower chords. The upper flange is arranged parallel to the lower chords and with respect to the plane defined by the lower chords plane perpendicular to the middle lower chord at a distance from this. The strut snake connects the straps in the order of upper strap, middle strap, left strap, middle strap, upper strap, middle strap, right strap, middle strap, upper strap and then again in that order, with the connection of the upper strap to the middle strap substantially perpendicular to the plane defined by the lower chords, and the connection from the lower chord to the lateral chords is substantially parallel to the plane defined by the lower chords.

In DE 28 40 532 A a lattice girder with a so-called T-shape is described as the prior art, which consists of two lower chords, a single upper chord, and a strut snake, the connection of the upper chord with lower chords in the order upper chord, first lower chord, Upper girth, second lower girth, upper girth and in this order further. The course of the strut snake is initially substantially perpendicular to the plane defined by the lower chord from the upper flange to the lower chord, and then substantially parallel to the plane defined by the lower chord.

DE 40 36 293 A discloses a lattice girder with two lower chords, a top chord and a strut snake.

The object of the invention is to provide a lattice girder offering advantages in use in prefabricated walls and ceilings, for example with regard to the spacing between insulating elements, and uses thereof.

This object is achieved by a lattice girder according to claim 1 or 2 or a use according to claim 9 or 10.

Further developments of the invention are specified in the subclaims.

Fig. 1

eine erste Ausführungsform des Gitterträgers;

Fig. 2

eine zweite Ausfühnmgsform des Gitterträgers;

Fig. 3

eine dritte Ausfühnmgsform des Gitterträgers;

Fig. 4

eine vierte Ausführungsform des Gitterträgers;

Fig. 5

eine fiinfte Ausführungsform des Gitterträgers

Fig. 6

eine sechste Ausführungsform des Gitterträgers;

Fig. 7

eine siebte Ausfiihrungsfonn des Gitterträgers;

Fig. 8

eine achte Ausführungsform des Gitterträgers;

Fig. 9

eine neunte Ausführungsform des Gitterträgers; und

Fig. 10

eine zehnte Ausführungsform des Gitterträgers;

wobei in jeder der Figuren die Ansicht a) eine Seitenansicht, die Ansicht b) eine Draufsicht, und die Ansicht c) eine perspektivische Ansicht des jeweiligen Gitterträgers zeigt, und in den Fig. 1, 4, 7 und 10 die Ansicht d) jeweils einen Querschnitt senkrecht zur Längsrichtung der Gurte zeigt, wobei der Querschnitt aus der Fig. 1d) auch den Querschnitt der zweiten und dritten Ausftihrungsforin zeigt, der Querschnitt aus Fig. 4d auch den Querschnitt der fünften und sechsten Ausführungsform zeigt, und der Querschnitt aus der Fig. 7d) auch den Querschnitt der achten und neunten Ausführungsform zeigt.Other features and advantages of the invention will become apparent from the description of embodiments with reference to FIGS. From the figures show:

Fig. 1

a first embodiment of the lattice girder;

Fig. 2

a second Ausfühnmgsform the lattice girder;

Fig. 3

a third Ausfühnmgsform the lattice girder;

Fig. 4

a fourth embodiment of the lattice girder;

Fig. 5

A fifth embodiment of the lattice girder

Fig. 6

a sixth embodiment of the lattice girder;

Fig. 7

a seventh embodiment of the lattice girder;

Fig. 8

an eighth embodiment of the lattice girder;

Fig. 9

a ninth embodiment of the lattice girder; and

Fig. 10

a tenth embodiment of the lattice girder;

wherein in each of the figures the view a) a side view, the view b) a plan view, and the view c) shows a perspective view of the respective lattice girder, and in Figs. 1, 4, 7 and 10, the view d) one each Cross section perpendicular to the longitudinal direction of the straps, wherein the cross section of Fig. 1d) also shows the cross section of the second and third Ausftihrungsforin, the cross section of Fig. 4d also shows the cross section of the fifth and sixth embodiment, and the cross section of FIG. 7d) also shows the cross section of the eighth and ninth embodiments.

A first preferred embodiment of the invention will be described with reference to FIG. As can be clearly seen in Fig. 1c), the lattice girder 1 has a first lower chord 11 and a second lower chord 12, a first upper chord 21 and a second upper chord 22, and a strut coil 30 connecting the lower chords and the upper chords. The lower and upper straps 11, 12, 21, 22 are in the same longitudinal direction straight extending metal rods. In the embodiment shown in Fig. 1, the metal rods have a round cross-section with the diameter x (see Fig. 1d)). The strut coil is also a bar iron having a diameter y (typically 5 mm ≤ x, y ≤ 10 mm).

The arrangement of the lower chords and the upper chords and the strut snake in the cross section of the lattice girder is shown in Fig. 1d). Such an arrangement is similar to the arrangement of a so-called Einhüftträgers.

As shown in Fig. 1d), the first lower chord 11 and the second lower chord 12, which extend in parallel, lie in a first plane. The first and the second Untergurt lie at a first distance (c - 2x) from each other, where obviously (c - 2x) >> y, for example, (c - 2x) = ay with 3≤ a≤ 30. The first upper flange 21 and the second upper flange 22 extend parallel to each other in a second plane and at a second distance corresponding to the diameter y of the strut coil 30. The second level is parallel to and at a third distance (b - x) from the first level.

The strut coil 30 has four types of sections connected to each other in a particular sequence to the continuous strut coil 30. The first section 31 is parallel to the first plane and contacts the first lower chord 11. The second section 32 is perpendicular to the first plane in the third plane. The third portion 33 lies in the third plane and contacts the first and the second top chords 21, 22. The fourth portion 34, like the first portion 31, is parallel to the first plane and contacts the second bottom chord 12. In the first embodiment the first portions 31 are each connected at at least one point to the first lower chord 11 by welding. The third sections 33 are each connected at at least one point to the first and / or second upper belt 21, 22 by welding. The fourth sections 34 are each connected at at least one point to the second lower flange 12 by welding.

In the first embodiment, the portions in the sequence are the first portion, the second portion, the third portion, the second portion, the fourth portion, the second portion, the third portion, the second portion, the first portion, the second portion, etc. (ie, 1,2,3, 2,4,2,3,2,1,2,3,2,4,2,3,2,1 ...) connected to a continuous strut coil 30.

In the first embodiment, as clearly seen in Fig. 1d), the first and second lower chords 11, 12 and the first and fourth portions 31, 34 are not only parallel to each other but in the same plane (the first plane).

Of course, it is obvious to the person skilled in the art from the consideration of FIG. 1 that the sections of the strut serpentine, which run at right angles to each other, do not have a right-angled transition but a transition section with a radius of curvature. The radius of curvature is, depending on the diameter y of the strut coil 30 and the machine used for the production to choose.

The strut coil sections 32 are substantially straight in the third plane, and in the first embodiment, the second sections 32 are perpendicular to the third plane at an angle ± α relative to the first plane.

The second preferred embodiment of the lattice girder will now be described with reference to FIG. The same reference numerals as in Fig. 1 denote corresponding parts or portions. The difference between the first and second embodiments is that the third portions 33 extend over a certain length (about e - 2 times the inner radius of curvature of the transition to the second portions 32) parallel to the upper chords 21, 22.

In the second embodiment, the second portions 32 of the strut coil also extend in a perpendicular projection to the third plane at an angle of ± α relative to the first plane. Depending on the size of the predetermined length e, which is also substantially present in the first sections 31, the second sections 32 could also be at right angles to the first plane, as is the case in the third embodiment, which is described below ,

In Fig. 3 showing the third preferred embodiment, the same reference numerals designate corresponding parts or portions as in the first and second embodiments. The third embodiment differs from the first and second embodiments in that the first, third and fourth portions 31, 33, 34 of the strut serpentine each extend over a predetermined length parallel to the top straps or bottom straps contacting them.

In the third embodiment shown in Fig. 3, the second portions 32 of the strut coil extend in a perpendicular projection on the third plane perpendicular to the first plane. However, it is also possible in a modification that the second sections 32 extend at an angle relative to the first plane, as in the first and second embodiments.

The first to third embodiments have in common that the lower chords lie in the same plane as the first and fourth sections of the strut coil. As a result, the height of the parts of the lattice girder extending parallel to the first plane is equal to the larger of the two diameters x and y of the lower chords and the strut snake.

The first to third embodiments further have in common that the second portions 32 of the strut coil are all in the third plane, which is perpendicular to the first plane. As a result, if, for example, insulating parts (such as insulation material blocks) are placed between the lattice girders, a minimal distance between the insulating parts is made possible.

The first to third embodiments further have in common that two upper straps are provided, which are mounted in the height direction of the lattice girder laterally on the strut coil. As a result, compared to attaching a top chord at the top inflection points in conjunction with the reinforcing ply to be attached to the top chords, a lower overall height, with the same static load capacity, is made possible.

The fourth, fifth and sixth embodiments will now be described with reference to Figs. In the figures, the same reference numerals as in Figs. 1 to 3 denote corresponding parts and portions of the lattice girders. The fourth, fifth and sixth embodiments differ from the first, second and third embodiments only in that the first and second lower chords 11, 12 are not disposed in the same plane as the first and fourth portions 31, 34 of the strut coil 30. In the fourth, fifth and sixth embodiments, as best seen in Fig. 4d), the first portions 31 contact the first lower chord 11 respectively at its lower side and the fourth portions 34 also contact the second lower chord 12 at the lower side thereof. It remains (c - 2x) >> y as in Fig. 1d). As also clearly seen, the first and fourth portions 31, 34 extend parallel to the first plane, respectively, by approximately one-half of the first distance (i.e., the distance of the two bottom chords).

The other features of the fourth embodiment are the same as those of the first embodiment, the remaining features of the fifth embodiment are the same as those of the second embodiment, and the remaining features of the sixth embodiment are the same as those of the third embodiment. Therefore, the further description of the fourth to sixth embodiments will be omitted.

The seventh, eighth and ninth embodiments will now be described with reference to Figs. In Figs. 7 to 9, the same reference numerals as in Figs. 1 to 6 denote corresponding parts and portions. Only the second sections are designated by different reference numerals 32a and 32b.

The difference of the seventh to ninth Ausfühningsform of the fourth to sixth embodiments, as best seen in the comparison of Fig. 4d) with the Fig. 7d), only in that the second portions 32a of the strut coil 30, the first Portions 31 connect to the third portions 33, and the second portions 32b connecting the fourth portions 34 to the third portions 33 are not exactly in the third plane, but in a perpendicular projection on a plane perpendicular to the third plane is an angle β to each other. The angle β is greater than 0 ° and less than 15 °, preferably less than 10 °. In the embodiment shown in Fig. 7, the angle is about 7 °.

Incidentally, the seventh embodiment of the fourth embodiment, the eighth embodiment of the fifth embodiment, and the ninth embodiment of the sixth embodiment.

Of course, the seventh through ninth embodiments may be modified so that the two bottom straps 11, 12 are not located under the first and fourth portions of the strut coil 30, respectively, but in the same plane as the first and fourth portions 31, 34 of the strut coil (as in FIG the first to third embodiments).

The tenth embodiment will now be described with reference to FIG. In Fig. 10, the same reference numerals as in Figs. 1 to 9 denote corresponding parts and portions.

The difference of the tenth embodiment from the first embodiment, as best seen from a comparison of Figs. 1a), d) and 10a), d), is evident in the "loops" extending from the third portions 33 of the strut coil 30 above the second level are formed in the third level. More precisely, the highest point of the third section lies 33 at a distance u (height of the loop) from the second level on the side of the second level facing away from the first level. The distance u is preferably in the range 2y ≦ u ≦ f / 3, and more preferably in the range 2y ≦ u ≦ 5y.

This feature of the loop formation, that is, the distance u of the highest point of the section 33 from the second plane, can be provided as a modification in all embodiments.

In all embodiments, the bottom straps and / or the top straps and / or the strut coil may be formed of steel or stainless steel or galvanized or otherwise coated (also with plastic).

The formation of the lattice girder as a kind Einhüftträger who stands, in addition to the advantages mentioned of the small distance of adjacent parts such as insulating parts or insulation parts also has the advantage that the corresponding parts are easy to transport.

Particularly advantageous is the use of lattice girders for ribbed ceilings or beam ceilings. Lattice girders can also be used advantageously for punching reinforcements. When using the lattice girders in prefabricated concrete parts for wall parts, preferably with two prefabricated, spaced concrete parts, or for roofs and ceilings, preferably with a prefabricated concrete part, the lattice girders for the reasons mentioned are particularly advantageous.

It is a new lattice girder in the manner of a Einhüftträgers indicated in which two upper and lower chords (11, 12, 21, 22) are provided, and the portions of the strut coil (30) that not parallel to the plane defined by the two lower chords plane run, essentially perpendicular, ie perpendicular or nearly vertical, relative to this plane.

The values and ranges of values given above in the individual embodiments apply to all embodiments.

Claims (10)

1. Truss consisting of
   a first lower chord (11) and a second lower chord (12),
   a first upper chord (21) and a second upper chord (22), and
   a strut serpentine (30),
   which are arranged in such a way that
   the first and second lower chords (11, 12) lie parallel to one another in a first plane and at a first spacing from one another,
   the first and second upper chords (21, 22) lie parallel to one another in a second plane and at a second spacing from one another, which corresponds to the diameter of the strut serpentine and is smaller than the first spacing,
   the first and second planes lie parallel to one another and at a third spacing from one another,
   a third plane, which is perpendicular to the first plane, intersects the first plane centrally between the first and second lower chords (11, 12) and intersects the second plane centrally between the first and second upper chords (21, 22),
   the strut serpentine (30) consists continuously of portions which are selected from four types of portion, namely a first portion (31), which is parallel to the first plane and is in contact with the first lower chord (11), a second portion (32), which is perpendicular to the first plane and lies in the third plane, a third portion (33), which lies in the third plane and is in contact with the upper chords, and a fourth portion (34), which is parallel to the first plane and is in contact with the second lower chord (12), and
   a first or fourth portion (31, 34) is in each case followed by a second, a third and a second portion (32, 33, 32) in this order and then again by a first or fourth portion (31, 34).
2. Truss consisting of
   a first lower chord (11) and a second lower chord (12),
   a first upper chord (21) and a second upper chord (22), and
   a strut serpentine (30),
   which are arranged in such a way that
   the first and second lower chords (11, 12) lie parallel to one another in a first plane and at a first spacing from one another,
   the first and second upper chords (21, 22) lie parallel to one another in a second plane and at a second spacing from one another, which corresponds to the diameter of the strut serpentine,
   the first and second planes lie parallel to one another and at a third spacing from one another,
   a third plane, which is perpendicular to the first plane, intersects the first plane centrally between the first and second lower chords (11, 12) and intersects the second plane centrally between the first and second upper chords (21, 22),
   the strut serpentine (30) consists continuously of portions which are selected from four types of portion, namely a first portion (31), which is parallel to the first plane and is in contact with the first lower chord (11), a second portion (32a, 32b), which, in a projection onto a plane which is at right angles to the first and third planes, runs at an angle of 90° - β/2 relative to the first plane and at an angle of β/2 relative to the third plane, both angles being different from 0°, a third portion (33), which lies in the third plane and is in contact with the upper chords, and a fourth portion (34), which is parallel to the first plane and is in contact with the second lower chord (12), and
   a first or fourth portion is in each case followed by a second, a third and a second portion in this order and then again by a first or fourth portion, in each case the two second portions (32a or 32b) which enclose a third portion (33) between them running in an inclined fashion, not in the same direction, relative to the third plane.
3. Truss according to Claim 1 or 2, in which the first and fourth portions (31, 34) of the strut serpentine (30) are in each case present alternately.
4. Truss according to one of Claims 1 to 3, in which the first and fourth portions (31, 34) of the strut serpentine and the first and second lower chords (11, 12) lie in the first plane.
5. Truss according to one of Claims 1 to 4, characterized in that the first and fourth portions (31, 34) of the strut serpentine and/or the third portions (33) of the strut serpentine in each case extend over a predetermined length parallel to the lower chords (11, 12) and upper chords (21, 22) with which they are in contact.
6. Truss according to one of Claims 1 to 5, characterized in that the second portions (32, 32a, 32b) of the strut serpentine run perpendicularly to the first plane in a projection onto the third plane.
7. Truss according to one of Claims 1 to 5, characterized in that the second portions (32, 32a, 32b) of the strut serpentine run at an angle of ± α relative to the first plane in a projection onto the third plane.
8. Truss according to one of Claims 1 to 7, characterized in that the lower chords and/or the upper chords and/or the strut serpentine is/are formed from stainless steel and/or coated.
9. Use of a truss according to one of Claims 1 to 8 in a prefabricated concrete building component, in which the lower chords and the first and fourth portions of the strut serpentine and if appropriate a part adjoining these portions of the second portions of the strut serpentine are cast into a prefabricated concrete component.
10. Use of a truss according to one of Claims 1 to 8 in a prefabricated concrete building component, in which the lower chords and the first and fourth portions of the strut serpentine and if appropriate a part adjoining these portions of the second portions of the strut serpentine are cast into a first prefabricated concrete component, and
    in which the upper chords, the third portions of the strut serpentine and if appropriate a part adjoining these portions of the second portions are cast into a second prefabricated concrete building component, and in which the first and second prefabricated concrete building components are essentially plate-shaped, lie parallel to one another and have a fourth spacing.

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