EP0632861B1 - Ceiling structure and process for producing it - Google Patents

Abstract

A ceiling structure with a reinforced cast concrete ceiling slab (1), a plurality of cast concrete stiffening ribs (2) reinforced by lattice beams (7) and filling components (3) fitted between the stiffening ribs, each of which has a self-supporting three-dimensional lattice body having an upper (13) and a lower lattice (14), web wires (19) binding the lattices (13, 14) together at predetermined intervals and a displacement body (20) irremovably secured by the web wires (19) between the lattices, in which the displacement body (20) of the filling component lies flush against a cast-on base strip (12) in a lattice beam (7) having such a strip or, in a lattice beam cast in situ, its underside lies flush against the side-members of a shuttering plate.

Description

The invention relates to a ceiling construction with a reinforced ceiling slab made of cast concrete, several reinforcing ribs made of cast concrete reinforced by lattice girders and filling elements arranged between the reinforcing ribs according to the preamble of claim 1.

A ceiling construction is known from AT-B-257 887. The stiffening ribs are each reinforced by a prefabricated girder, which consists of a lattice girder and a concrete base, which can be embedded in a brick shoe. Each filling element consists of a so-called cap stone and a view stone, both of which are suspended on the base of the precast element. The main disadvantage of this ceiling construction is that the lattice girders used to reinforce the stiffening ribs, which must be designed in accordance with the structural requirements of the ceiling construction, have to bear the weight of the filling elements when the ceiling is being constructed on site.

The object of the invention is to provide a ceiling structure which avoids this disadvantage and simplifies the design of the ceiling structure on the construction site. This is achieved according to the invention in a ceiling construction of the type specified in the introduction by the features of claim 1.

The side parts of the skirting board or the side parts of the formwork sheet preferably run outwards and inwards Slightly sloping at the top, the side parts of the formwork sheet having slots for the wires of the lower grid mat.

According to a further embodiment of the invention, the reinforcement of the ceiling slab is formed by the upper lattice mats of the filling elements and in the area of the stiffening ribs, butting reinforcements covering the lattice mats at their edges.

The ceiling construction according to the invention ensures that the filling elements as well as the lattice girders used to reinforce the stiffening ribs can be supported in such a way that the lattice girders themselves are not additionally loaded by the filling elements on the construction site.

It should be mentioned that EP-A-0 511 193 discloses a reinforcement body for a cast concrete ceiling slab provided with stiffening ribs. The reinforcement body has a basic reinforcement, a distributor reinforcement as well as web wires connecting the base and distributor reinforcement and immovably fixing one or more displacement bodies. The basic reinforcement, the distribution reinforcement and the displacement body (s) form a dimensionally stable unit. According to EP-A-0 511 193, either a plurality of rib cavities are formed in a one-piece displacement body to form the stiffening ribs, or a plurality of displacement bodies are arranged within the reinforcement body in such a way that a plurality of rib cavities are formed between the displacement bodies of the reinforcement body. A disadvantage of the known reinforcement body is that the basic and distribution reinforcement extends over the entire reinforcement body, that is also over the areas of the rib cavities. This makes production more difficult and consumes more material than would be necessary. The reinforcement body is accordingly also provided with a concrete element, which extends over the entire width of the reinforcement body and thus also extends over the rib cavities. According to EP-A-0 511 193, the ceiling plate formed with the reinforcement body has an upper and a lower element plate and a plurality of stiffening ribs connecting the two element plates. In contrast, with the aid of the reinforcement body according to the invention, a ceiling structure is formed which has only an upper element plate and stiffening ribs The reinforcement ribs widen slightly in the case of lattice girders cast in situ, ie lattice girders without a previously cast-on skirting board, due to the design and arrangement of the formwork sheets on the underside of the ceiling structure. The formwork sheet, which is intended to prevent the concrete from leaking when concreting the stiffening ribs, extends with a predetermined lateral overhang beneath adjacent filling elements. A lower element plate, which extends over the entire width of the ceiling, as in EP-A-0 511 193, is not provided according to the invention, but only a lower end of the stiffening ribs. The load-bearing capacity of the ceiling according to the invention is ensured solely by the upper element plate. In contrast to EP-A-0 511 193, the lower area of the filling elements remains free, which advantageously saves a considerable amount of concrete.

The invention also relates to a method for producing the described ceiling structure according to claims 1 to 3, which is characterized in that several supports are set up at predetermined intervals in accordance with the respective length and width of the filling elements, and mounting boards aligned with the stiffening ribs on the supports placed and arranged on the mounting boards at the edge of the stiffening ribs support boards for the filler elements, whereupon on the mounting boards either lattice girders provided with a concrete skirting board or formwork sheets for concreting the stiffening ribs are arranged in situ, the formwork sheets supporting the lattice girders and then on the supporting boards the filling elements are arranged, which are flush with the adjacent skirting boards, or the displacement body with its underside on the side overlapping the edges of the displacement body attack parts of the formwork sheets, and then pour the ceiling slab.

FR-A-896 890 relates to a structural element made of reinforced concrete for building a ceiling and a method for producing this ceiling. The construction element consists essentially of supporting elements, a lattice work, a network stretched over the lattice work and reinforcing bars for reinforcing the ceiling slab. The latticework consists of clamping elements and longitudinal reinforcement bars. To build the ceiling, the girders are placed on supports, then the latticework is applied, the net is stretched over the lattice, the reinforcing bars are attached to protrusions of the latticework and finally the in-situ concrete is poured. The underside of the lattice can be closed with a metallic lattice. However, the known method shows the following differences compared to the inventive method: no fillers made of insulating material are used; the reinforcement of the top slab is done by single bars and not by mesh panels; the girders are not reinforced by lattice girders, a concrete skirting board is also not used; the latticework is also part of the reinforcement of the stiffening ribs and is not completely separated from the stiffening ribs.

The advantage of the method according to the invention, which works with prefabricated, self-supporting filling elements and prepared lattice girders for reinforcing the stiffening ribs, is therefore not given in the known solution, because the individual elements are composed of several individual components which are only put together in time-consuming construction work on the construction site have to.

According to the invention, in the case of stiffening ribs cast in situ, the lattice girders are preferably supported on the formwork boards by means of spacers.

The invention is explained in more detail below using exemplary embodiments with reference to the drawings explained.

• Fig. 1 ein Ausführungsbeispiel einer Deckenkonstruktion gemäß der Erfindung im Querschnitt,
• Fig. 2 ein weiteres Ausführungsbeispiel einer erfindungsgemäßen Deckenkonstruktion,
• Fig. 3 ein Schalungsblech zum Betonieren der Aussteifungsrippen im Querscnnitt,
• Fig. 4 einen Detailausschnitt des Seitenteiles des Schalungsbleches nach Fig. 3,
• Fig. 5 eine Draufsicht eines Ausführungsbeispieles einer Deckenkonstruktion mit schematisch angedeuteten Montageunterstützungen, und
• Fig. 6 einen Längsschnitt durch die Deckenkonstruktion nach Fig. 5.

Show it:

• 1 shows an embodiment of a ceiling structure according to the invention in cross section,
• 2 shows another embodiment of a ceiling construction according to the invention,
• 3 is a formwork sheet for concreting the stiffening ribs in cross section,
• 4 shows a detail of the side part of the formwork sheet according to FIG. 3,
• Fig. 5 is a plan view of an embodiment of a ceiling structure with schematically indicated mounting supports, and
• 6 shows a longitudinal section through the ceiling construction according to FIG. 5.

The ceiling structure shown in Fig. 1 has a ceiling plate 1 made of cast concrete, a plurality of stiffening ribs 2, which are arranged at a selectable distance from one another in accordance with the structural requirements of the ceiling structure, and a plurality of filling elements 3, which extend between the stiffening ribs 2. A distributor reinforcement 4 is arranged in the ceiling slab 1, for example in the form of a grid mat, which consists of longitudinal wires 5 and transverse wires 6 which are arranged perpendicular to one another and welded to one another at the crossing points.

Each stiffening rib 2 is reinforced with a lattice girder 7. The lattice girder 7 consists of an upper chord 8 and two lower chords 9, which are non-positively connected to the upper chord 8 by a zigzag infill 10.

Depending on the structural requirements of the ceiling, the lattice girder 7 is reinforced by one or more additional reinforcements 11 in the area of the lower chords 9. The lower chords 9 and the allowances 11 of the lattice girder 7 are concreted in a baseboard 12. The reinforcement element of the stiffening ribs 2, consisting of the lattice girder 7, the allowances 11 and the concrete skirting 12, is already finished in the manufacturing plant and as complete unit delivered to the construction site.

The filling elements 3 have an upper lattice mat 13 and a lower lattice mat 14, which each consist of longitudinal wires 15 and 16 and transverse wires 17 and 18, which are arranged perpendicular to one another and welded to one another at the crossing points. The upper and the lower grid mat 13 and 14 of the filling element 3 are connected to one another by a plurality of inclined web wires 19.

Between the upper grid mat 13 and the lower grid mat 14, a displacement body 20 of a predetermined height is arranged in the middle, which expediently consists of foam, for example styrofoam. The web wires 19 penetrate the displacement body 20 and, as shown in FIG. 4, are arranged such that the displacement body 20 is immovably and fixedly fixed between the upper and lower grid mat 13 and 14, respectively. In the context of the invention, the web wires 19 can also run perpendicular to the upper and lower grid mat 13 or 14. In this case, it must be ensured by means of suitable fastening means that the displacement body 20 is also immovably and fixedly fixed between the upper and lower grid mat 13 and 14, respectively.

Since the filler element is constructed in the form of a three-dimensional, dimensionally stable lattice body, the filler element is self-supporting and is therefore able to bridge large spans without support during the construction of the ceiling structure at the construction site.

In the exemplary embodiment of the ceiling construction shown in FIG. 2, the reinforcement of the ceiling slab 1 is formed from the respective upper lattice mats 13 of the filler elements 3, wherein to cover the joints between the filler elements 3, an impact reinforcement 21 is placed overlapping on the upper lattice mats 13 of the filler elements 3 and connected to the wires of the grid mats, for example bridging. Within the scope of the invention, both mesh mats and individual reinforcing bars can be used as impact reinforcement. It is understood that in this embodiment, the upper grid mats 13th the filling elements 3 must be dimensioned and constructed so that they meet the static requirements of the ceiling slab to be produced.

The reinforcement of the stiffening ribs 2 is carried out by a lattice girder 7 ', which is constructed in accordance with the exemplary embodiment shown in FIG. 1 and is also provided with additional reinforcements 11 arranged in the region of the lower flange 9. Different variants are shown in FIG. 2 for determining the position of the lattice girders 7 ′ including supplements 11 in the stiffening ribs 2. According to one embodiment variant, the lattice girder 7 'together with allowances 11 is placed on a plurality of filling elements 3 common, lower lattice mat 14' bridging the gap in the area of the stiffening rib 2, and connected to it, for example bridged. The common lower grid mat 14 'consists of longitudinal wires 16' and transverse wires 18 'which are arranged perpendicular to one another and welded to one another at the crossing points.

Since the lattice girders 7 'in the exemplary embodiment according to FIG. 2 do not have a concrete skirting and therefore the concrete would flow out when concreting the ceiling slab 1 and the stiffening ribs 2, 2 temporary formwork sheets 22 are attached as the lower end of the stiffening ribs to be concreted. The slightly sloping side parts 23 of the formwork sheets 22 (FIG. 3) are provided with slots 24 (FIG. 4) in order to be able to push the formwork sheets 22 between the cross bars 18, 18 'of the lower lattice mats 14, 14' in such a way that the Completely close the side parts 23 with the underside of the displacement body 20 and thereby prevent the concrete from flowing out when the reinforcing ribs 2 are concreted on. According to a further embodiment variant shown in FIG. 2, the lattice girder 7 ′ including supplements 11 is arranged on a spacer 25, which in turn stands on the formwork sheet 22.

The construction of the ceiling structure at the construction site is carried out according to the schematic representation in FIGS. 5 and 6 in the following manner. On several supports 26, which in are arranged according to the length and width of the filling elements 3 selected spacing, mounting boards 27 are placed, which are aligned with the stiffening ribs 2 and parallel to them perpendicular to the longitudinal extension of the filling elements 3, which extend over the entire width of the ceiling structure to be produced. Since the self-supporting filler elements 3 can bridge much larger spans without additional supports than conventional filler elements, the spacing of the supports 26 in the longitudinal direction of the filler elements 3 can be chosen to be correspondingly larger than in previously known ceiling constructions. Depending on the embodiment of the reinforcement of the stiffening ribs 2, either the lattice girders 7 provided with a prefabricated baseboard 12 or the formwork sheets 22 are then placed on the mounting boards 27. When using lattice girders 7 'without a skirting board, the lattice girders 7' are placed in the formwork sheets 22 in the following work step. The distance between the lattice girders 7 'and the formwork sheet 22 is determined by the fact that either the lattice girders 7', optionally with the allowances 11, rest on the spacers 25 or on the lower, several filling elements 3 common lattice mat 14 '. On the mounting boards 27, support boards 28 are placed as close as possible to the formwork sheets 22 or the baseboards 12 of the lattice girders 7, which have the task of carrying the filler elements 3 during the formation and when concreting the ceiling structure. The displacers 20 of the filling elements 3 must be flush with the skirting boards 12 of the lattice girders 7 laterally to prevent the concrete from flowing out when the reinforcing ribs 2 are concreted.

Due to the construction of the assembly supports 26, 27, 28 described above, the lattice girder 7, 7 'is not burdened by the weight of the filling elements 3 when the ceiling structure is being constructed at the construction site, and can therefore be dimensioned correspondingly smaller.

To reinforce the ceiling slab 1 either in following work step, the distributor reinforcement 4 or the impact reinforcements 21 are placed on the upper mesh mats 13 of the filling elements 3 and connected, for example bridged, to the wires of the mesh mats. In the subsequent step, the stiffening ribs 2 are poured with concrete and the ceiling slab 1 is concreted. After the concrete has set, the formwork sheets 22 and the assembly supports 26, 27, 28 are removed and are available again for the formation of a further ceiling construction.

It is understood that the exemplary embodiments described can be modified in particular with regard to the type and design of the reinforcement elements for the ceiling slab and the stiffening ribs. Hiebei it is possible within the scope of the invention to equip a ceiling construction either with only one type of reinforcement elements or with different combinations of different types of reinforcement elements for the ceiling slab and the stiffening ribs. The underside of the ceiling can also be closed with a non-supporting end plate, not shown, which is attached to the wires of the lower grid mat of the filler elements and can be designed, for example, as a decorative plate.

Other assembly assumptions can also be used within the scope of the invention. In all cases, however, it must be ensured that the filler elements, like the lattice girders, are placed under the reinforcement of the stiffening ribs and that the lattice girders are not loaded by the filler elements when the ceiling structure is formed.

Claims (5)

1. A slab structure comprised of a reinforced poured concrete slab (1), a plurality of poured concrete stiffening ribs (2) reinforced by lattice girders (7, 7') and filling elements (3) disposed between the stiffening ribs, each filling element (3) having a self-supporting three-dimensional gridwork body comprised of an upper gridwork mat (13) and a lower gridwork mat (14; 14'), fixed connecting rods (19) connecting the gridwork mats (13; 14, 14') at a predetermined distance apart, and a one-piece separator body (20) securely fixed between the gridwork mats (13; 14, 14') by means of the connecting rods (19), characterized in that either in the case of a lattice girder (7) which is included in a concretized base beam (12), the separator body (20) of the filling element (3) is sealingly lodged against said base beam, or in the case of a lattice girder (7') which is concretized by pouring of concrete in situ, the lower side of said separator body (20) in the edge region is overlapped by a side portion of a base beam (12') which forms a bottom boundary of the stiffening rib (2) and is formed by means of a temporary form panel (22), and in that the lower side of the separator body (20) and the lower gridwork mat (14, 14') of the gridwork bodies remain between the adjacent sides of the base beams (12, 12') without concrete covering.
2. A slab structure according to claim 1, characterized in that the side portions of the base beam (12') or the side portions (23) of the form panel (22), respectively, extend slightly obliquely outwards and upwards, the side portions of the form panel comprising slots (24) for the wires of the lower gridwork mat (14, 14').
3. A slab structure according to claim 1 or 2, characterized in that the reinforcement of the slab (1) is formed by the upper gridwork mats (13) of the filling elements (3) and gap reinforcements (21) disposed in the regions of the stiffening ribs (2), which reinforcements (21) overlap the gridwork mats (13) at their edge regions.
4. A method of constructing a slab structure according to one of claims 1 to 3, characterized in that a plurality of pillars (26) are erected at predetermined distances apart, which distances correspond to the respective lengths and widths of the filling elements (3), a plurality of supporting boards (27) are placed on said pillars (26), which boards (27) extend flush with the stiffening ribs (2), and a plurality of prop boards (28) for the filling elements (3) are placed on said supporting boards (27) at positions disposed at edges of the stiffening ribs (2), whereupon either respective concretized base beams (12), each of which includes a lattice girder (7), are placed on the respective supporting boards (27), or respective concrete-form panels (22) for concretizing the stiffening ribs (2) in situ are placed on the respective supporting boards (27), the concrete-form panels (22) supporting the lattice girders (7') and forming a bottom boundary of the respective stiffening ribs (2), and in that thereafter either the filling elements (3) are disposed on the prop boards (28) and are sealingly lodged against the respective adjoining concretized base beams (12), or said separator bodies with their lower side are sealingly disposed against lateral parts (23) of the respective concrete-form panels (22), which lateral parts overlap the edges of the separator body sideways, following which the slab is concretized by pouring concrete.
5. A method according to claim 4, characterized in that, in the case of stiffening ribs (2) which are poured in situ, the lattice girders (7') are supported on the concrete-form panels (22) by means of spacers (25).

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