CZ243298A3 - Truss for reinforcing concrete slab - Google Patents

Abstract

Braced girder for reinforcing a concrete panel, with a u-shaped lower and upper chords (3, 4) and girder rods (5) soldered laterally on the lower and upper chords (3, 4) and connecting the latter, wherein a shuttering panel (2) can be fixed parallel to the lower and upper chords (3, 4) on both sides of the braced girder and the girder rods (5) exhibit protuberant segments on top of the upper or lower chords (3, 4), which separates the shuttering panel (2) from the upper or lower chords (3, 4) at a distance allowing the concrete to surround the upper and lower chords (3, 4). The girder rods (6) are embodied as c-shaped stirrups with ends (6) bent outwardly 90 DEG , wherein the protuberant segments on top of the upper or lower chords (3, 4) of the c-shaped stirrup have been treated preferably with an anticorrosive coating.

Description

BACKGROUND OF THE INVENTION The present invention relates to a truss for reinforcing a concrete slab, with upper and lower bands of the U-profile and the lattice bars welded to the trusses on both sides of the upper and lower bands. truss rods have sections overlapping the upper or lower sections. a lower belt for keeping the sheeting at a distance, allowing the upper and lower belts to be concreted,

BACKGROUND OF THE INVENTION

A truss of this kind is known from Fig. 13 of WO 93/15287. The illustrated truss consists of two upper and lower trusses, respectively. a lower strip of forming, flat webs in the form of sheet metal strips which are arranged parallel to each other, the two flat webs being connected by welded arc snakes.

The arc snakes overlap the flat webs on both sides, so that the adjacent sheeting plates are thus far apart from the flat webs, so that the concrete is filled, preferably 15 to 50 mm. By fully embedding the flat webs into the concrete, corrosion is effectively prevented.

The lattice girder of the prior art can be produced only by expensive special machines due to its shaping, which is disadvantageous in the production costs.

It is therefore an object of the present invention to simplify the known truss, while retaining all the features of stability and functionality, to enable simpler, less automated manufacturing processes. This requirement stems in particular from the fact that concrete slabs, reinforced with trusses, are often produced and used to build prefabricated houses in third world countries.

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SUMMARY OF THE INVENTION

The stated goal is achieved by a truss for reinforcing the concrete slab, with upper and lower belts of the U-profile and connected with them, welded lattice bars welded on the sides of the upper and lower belts, while the trusses are fastened on both sides parallel to the upper and lower belts. and truss rods have sections overlapping the upper and lower sections, respectively. a lower strip for keeping the shoring plate at a distance allowing the upper and lower strips to be concreted according to the invention, characterized in that the trusses are designed as C-shaped yokes with ends bent 90 ° outwards.

By creating trusses connecting the upper and lower strips in the form of individual yokes displaceable in different ways, the production of trusses can be substantially simplified and the expensive production lines can be dispensed with. The C-shaped yokes are made by hand or by simple bending machines, with only the two ends bending 90 ^° outwards, and then welded in different formations to the upper and lower belts. The ends will usually be straight, but they can also be curved.

In addition, by providing trusses according to the invention, corrosion of the truss regions adjacent to the shoring plates can be prevented in a simple manner. To this end, it is advantageous to provide sections of truss rods in the shape of C, which in the welded state protrude the upper and / or lower sections. lower belt, anticorrosive protection. The endangered truss rod regions can be either galvanized or plastic-coated. Corrosion protection according to the prior art is not possible for the complex shaping of arc snakes welded on the sides to the upper and lower belts.

Depending on the static stress, it is further provided that the trusses are aligned at right angles to the upper and lower belts in the form of a serpentine line. In a further variant, it is remembered that they are adjacent to each other.

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9 Two lattice bars with the same arrangement are spaced at a small distance from each other.

According to a preferred embodiment, the shoring plates can be firmly screwed by 90 ° washers to the bent ends of two adjacent C-shaped lattice bars. This offers the advantage that at least one shoring plate can be connected from the inside to the trusses so that the outer surface remains intact and followed by no additional machining, increasing costs.

In order to achieve a greater support surface for the sheeting plates, it is suitable that the C-shaped lattice rods project outwardly at an angle of about 45 ° with respect to the plane passing through the upper and lower belts with their outwardly bent bars.

BRIEF DESCRIPTION OF THE DRAWINGS

Further features and details of the invention will be apparent from the following description with reference to the drawings, in which the individual figures show:

FIG. 1 is an oblique view of a wall lining element provided with lattice girders according to the invention; FIG. 2 a lattice girder with serpentine line arrangement; FIG. 3 a lattice girder with simple lattice bars running at right angles to the upper and lower waist;

FIG. 4 shows a truss in which the trusses are arranged in pairs, also welded at right angles to the upper and lower strips; FIG. 5 shows a detail of the fastening of the shoring plates on the truss, FIGS. 6 and 7 Fig. 8 a special shape of C-shaped trusses with cranks and Fig. 10 a plan view of a truss with offset offset trusses with cranks for seating additional transverse members

DETAILED DESCRIPTION OF THE INVENTION

The truss according to the invention, as shown, for example, in FIG. 2, consists essentially of an upper strip 3, a U-profile, a lower strip 4, a U-profile, and side welded trusses connecting the upper and lower strips in the form of a C-shaped truss. with the ends 6 bent 90 ° outwards. The trusses 5, to whose outwardly bent ends 6 the lining plates 2 adjoin, protrude on both sides of the upper strip 3 or 3, respectively. the lower belt 4 so that the sheeting plates 2 remain spaced from the belts. The resulting complete concreting of the upper strip 3 and the lower strip 4 provides permanent corrosion protection. Moreover, since the upper and lower strips, in particular those regions of the trusses 5, which overlap the upper and lower strips, respectively. the lower strip and partially adhere to the shoring plates 2, are endangered by corrosion, it is advisable to galvanize or coat these areas before welding.

The different arrangement of the trusses 5 shown in the figures depends on the type of stresses of the concrete slab to be produced, to which it is subjected in use. If the lattice girder, adjacent to one another at a small distance, has the outwardly bent ends 6 of the lattice members 5, as is the case shown in FIGS. screw from the inside. In detail, this type of fastening is recognizable from FIG. 5. The two mutually adjacent ends 6 of the two trusses 5 are covered with a washer 8 and the bolt 7 extending between the two ends 6 is connected to the adjacent lining plate 2. Thereby, at least one lining plate 2 of one wall sheeting element remains intact on its outer side.

Giant. 6 shows how, in a manner known per se, two lining plates 2 can be fastened to the upper belt 3. Externally screwed screws 9 penetrating the lining plate 2 and the upper belt 3 interconnect the lining plate 2 with the upper belt 3. This second fastening variant is advantageous if the shoring plates 2 do not remain on the finished concrete slab, but are removed after the wall element has been cast.

Giant. 7 shows a further embodiment in which the upper belt 3 and the lower belt 4 are formed as a one-piece element. With this embodiment, the manufacturing process is further simplified since the upper and lower strips are correctly aligned with each other prior to welding of the first trusses.

In the truss shown in FIG. 8, the C-shaped trusses 5 are inclined laterally by about 45 [deg.] Compared to FIG. As a result, a greater bearing surface is achieved for the sheeting panels 2 adjacent to the ends 6 of the trusses 5.

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Finally, a special variant of the C-shaped lattice structure can be seen from FIGS. 9 and 10. The lattice rods 5 have, in sections overlapping the upper strip 3, respectively. bottom web 4 formed by folds H If two trusses 5 formed in this manner are diagonally offset relative to one another, as shown in FIG. 10, an additional transverse rod 12 can be arranged and fastened in the region between the two folds 11. Of course, it is also possible to count two transverse rods extending in parallel, one being arranged above the upper strip 3 and the other below the lower strip 4. By this measure, the strength of the resulting concrete slab is further increased.

Claims (11)

1. A truss for reinforcing a concrete slab, with upper and lower U-profile strips and connected to them, welded trusses on the sides of the upper and lower strips, the trusses and lattice plates fixed on both sides parallel to the upper and lower strips. the rods have sections overlapping the upper or lower rods. a lower strip for keeping the lining plate apart, allowing the upper and lower belts to be concreted, characterized in that the trusses (5) are formed as C-shaped yokes with the ends (6) bent 90 ° outwards. A truss according to claim 1, characterized in that the sections of the C-shaped trusses (5) overlap the upper and lower sections respectively. the lower belts (3, 4) are provided with corrosion protection. A truss according to claim 2, characterized in that the sections of the C-shaped trusses (5) overlap the upper and lower sections respectively. the lower strips (3, 4) are galvanized. A truss according to claim 2, characterized in that the sections of the C-shaped trusses (5) overlap the upper and lower sections respectively. the lower strips (3, 4) are coated with plastic. A truss according to claim 1, characterized in that the trusses (5) extend at right angles to the upper and lower belts (3, 4). A truss according to claim 1, characterized in that the trusses (5) are aligned with one another in the form of a serpentine line. 9 ··· A truss according to claim 1, characterized in that two trusses (5) with the same orientation are arranged side by side at a small distance. A truss according to claim 1, characterized in that the lining plates (2) are rigidly connected by means of shims (8) to the 90 ° outwardly bent ends (6) of two adjacent C-shaped trusses (5). A truss according to claim 1, characterized in that the C-shaped trusses (5) with their outwardly bent ends (6) project outwards at an angle of about 45 ° relative to the plane of the upper and lower belts (3, 4). ). A truss according to claim 1, characterized in that the C-shaped trusses have overlapping upper and lower sections, respectively. the lower belt (3, 4) of the kink (11). A concrete slab consisting of lining plates (2) spaced by a truss according to claim 1, characterized in that the space between the lining plates (2) is filled with concrete.