WO2002022983A1

WO2002022983A1 - Shell structure and method for manufacturing said shell structure

Info

Publication number: WO2002022983A1
Application number: PCT/SE2001/001905
Authority: WO
Inventors: Tommy Andersson; Stefan Larsson
Original assignee: Nordmarkens Betongprodukter Aktiebolag
Priority date: 2000-09-13
Filing date: 2001-09-07
Publication date: 2002-03-21
Also published as: SE0003278D0; AU2001282839A1; SE0003278L; SE517246C2

Abstract

The invention relates to a method for manufacturing a prefabricated shell structure (1) for installation in a building construction, which prefabricated shell structure comprises at least two shells (2, 3, 3' etc.), which shells are arranged at a distance fromone another by means of load-bearing distance pieces (4, 4' etc.) separating the shells, the distance pieces being mounted against an essentially horizontally arranged form (12) in a number and type necessary for transprot, handling and installation of the finished shell structure, and the first shell being cast against said form either before or after them mounting of the distance pieces. According to the invention, a sealing layer (20) which forms a new casting base is arranged on and between the distance pieces and the edge enclosures (19) of the form and at a distance from the previously cast shell, after which a new shell is cast on top of this sealing layer. The invention also relates to a prefabricated shell strucutre comprising at least two shells, which shells are arranged at a distance form one another by means of distance pieces. According to the invention, the shells consist of shells cast previously, subsequently and in this conneciton one above another, and the shell structure also comprises at least one sealing layer, which layer or layers is or are arranged on and between the distance pieces and the edges (8, 9, 10, 11) of the shell structure, at a distance from a previously cast shell, and which sealing layer constituted a new casting base during casting of a shell cast subsequently in relation to the previously cast shell and on top of this sealing layer.

Description

SHELL STRUCTURE AND METHOD FOR MANUFACTURING SAID SHELL STRUCTURE

TECHNICAL FIELD The present invention relates to a method for manufacturing a prefabricated shell structure for installation in a building construction, which prefabricated shell structure comprises at least two shells, which shells are arranged at a distance from one another by means of load-bearing distance pieces separating the shells, the distance pieces being mounted against an essentially horizontally arranged form in a number and type necessary for transport, handling and installation of the finished shell structure, and the first shell being cast against said form preferably by means of concrete either before or after the mounting of the distance pieces.

The invention also relates to a prefabricated shell structure manufactured according to said method, comprising at least two shells, which shells are arranged at a distance from one another by means of distance pieces.

PROBLEM PRESENTATION AND BACKGROUND OF THE INVENTION

Here, the designation "prefabricated shell structure" used above means especially raw materials which are manufactured in a factory or in another place specially set up for manufacturing such raw materials, which raw materials are transported to and installed in a building construction and which raw materials are, if appropriate, completed to form finished structural elements in conjunction with installation or somewhat later, for example by virtue of the prefabricated shell structure being used, after installation, as a permanent form into which concrete is introduced for casting together with an already existing element or structural part, for example a floor, and/or with an element or structural part which is cast simultaneously, for example a roof slab or intermediate floor, which is then cast together with, for example, a wall element.

However, the known examples of prefabricated shell structures indicated above and other comparable examples for installation in a building construction and known methods for manufacturing such shell structures have a number of considerable disadvantages which the present invention aims to solve.

For example, in the conventional manufacture of, for example, shell wall formwork intended for permanent casting, the shells making up the shell structure must be cast separately, whereupon the shells are, after the necessary setting has taken place for the separate shells, turned to face one another and assembled by means of, for example, welding to form the shell structure described comprising at least two shells arranged at a distance from one another, or a first shell is cast initially, which, after the necessary setting, has to be applied to a green and as yet unset shell in order to produce said shell structure.

The reinforcement between the shells which is used in conventional shell structures, for example in the form of reinforcing cages, reinforcing stays and/or individual reinforcing irons, constitutes an impediment to the subsequent installation of pipe runs, ventilation ducts, insulation etc. because normally this reinforcement is either spread over the entire area or over a large part of the area of the shell structure or is in the form of longitudinal, transverse and/or intersecting reinforcement fields, for example in the form of said stays and cages, dividing an area between the shells into zones, which in said manner constitute an impediment. The shells are interconnected via the reinforcement so that the shell structure can take up loads during transport, handling and installation, for example by welding and/or binding the reinforcements of the shells concerned to one another, which is complicated and time-consuming.

The laying-out of all the dimensions of the shell structure concerned and the positions of component features comprising, for example, openings and recesses for doors, windows, voids, telecommunications, electricity, water, drainage etc., has to be carried out once for each shell included in the shell structure. This is both time-consuming and labour- intensive and, if errors arise in the laying-out, this will seriously complicate or render entirely irnpossible the joining together of the individual shells, because the shells will then not fit one another. It is also clear that the handling of the individual shells, for example a wall shell, during said joining together to form a shell wall is both complicated and full of risks as the shell breaks easily on account of its own weight, incomplete setting and/or its inadequate strength when the shell is not handled in the state of being joined together with other shells.

Owing to the complicated reinforcement between the shells, the mounting of extra reinforcement usually takes place before casting of the prefabricated shell structure. Moreover, any insulation frequently has to be mounted on the outer sides of the shells for the same reason. It is therefore desirable for it to be possible for the installation of this extra reinforcement, any insulation and other components, in the form of, for example, ventilation, pipes and cabling, to be carried out in a simple manner when in situ casting takes place after installation to form the building construction concerned. THE OBJECT AND FEATURES OF THE INVENTION

One object of the present invention is to provide a method for manufacturing a prefabricated shell structure for installation in a building construction and a prefabricated shell structure manufactured according to said method, which method and shell structure considerably reduce or completely eliminate the abovementioned problems, and in which connection the favourable effects of the shell structure for construction work can be made use of in a better manner than previously.

The method according to the invention is characterized in that a sealing layer which forms a new casting base is arranged on and between the distance pieces and the edge enclosures of the form and at a distance from the previously cast shell, after which a new shell preferably consisting of concrete is cast on top of this sealing layer.

The shell structure according to the invention is characterized in that the shells consist of shells cast previously and subsequently in relation to one another and in this connection one above another, in that the shell structure also comprises at least one sealing layer, which sealing layer or layers is or are arranged on and between the distance pieces and the edges of the shell structure and at a distance from a previously cast shell, and which sealing layer constituted a new casting base during casting of a shell cast subsequently in relation to the previously cast shell and on top of this sealing layer.

According to further aspects of a method according to the invention:

a supporting layer is arranged on the edge enclosures of the form and/or the distance pieces and over the area enclosed by said edge enclosures, and said sealing layer is held away and at a distance defined by the supporting layer from the shell cast first;

additional sealing layers are arranged on and between the distance pieces and the edge enclosures of the form, above and at a distance from previous sealing layers and from a cast shell located under each sealing layer, and a new shell is cast preferably from concrete on top of each additional sealing layer between each new arrangement and the next of an additional sealing layer;

additional supporting layers are arranged on the edge enclosures of the form and/or the distance pieces and over the area enclosed by said edge enclosures, and a sealing layer is held away and at a distance defined by the supporting layer concerned from the shell cast first; a number of distance pieces are arranged from each future intermediate shell before an additional new supporting layer and/or sealing layer is arranged on these additional distance pieces and the edge enclosures of the form before the casting of an additional shell on top of said additional sealing layer;

at least one, some of or all the shells are reinforced before casting and/or fibrous concrete is used for casting;

the shells are manufactured with at least one side domed or curved and/or with integrated stiffening means in the form of, for example, beams or columns;

the shell structure is completed to form a finished structural element by being used, after installation, as a permanent form into which concrete or fibrous concrete is introduced for casting together with an already existing element or structural part and/or with an element or structural part which is cast simultaneously;

the distance pieces are manufactured from mesh material.

According to further aspects of a shell structure according to the invention:

the shell structure is manufactured according to any one of the method claims.

ADVANTAGES OF THE INVENTION

A factory for manufacturing conventional shell structures according to previous methods is very expensive to build. A corresponding factory for manufacture according to the new manufacturing method is considerably less expensive, and the cost is estimated at only roughly 20% of the previous building cost.

Moreover, the new method described in greater detail below is much quicker and cheaper than previous methods. This is possible because, for example, no welding together is required between the separate shells of the shell structure. The laying-out, installation and arrangement of openings, enclosures, distance reinforcements etc. for a shell structure comprising, for example, two separate shells is virtually halved, as these measures have to be taken for essentially only the shell cast first. The risk of the openings etc., which were previously arranged for each shell separately, not fitting together on joining together is therefore completely eliminated. Furthermore, additional installation of pipes and cabling, ventilation etc. can be carried out easily on the building site in conjunction with the installation of the shell structure to form the building construction concerned between the zones of distance reinforcements which were arranged during manufacture of the prefabricated shell structure.

LIST OF FIGURES

The invention will be described in greater detail below with reference to the accompanying figures, in which:

Fig. 1 is a diagrammatic side view of parts of a shell structure according to the present invention for installation and subsequent completion to form a finished structural element in a building construction, which shell structure comprises two shells which are arranged at a distance from one another by means of a number of distance pieces indicated by dashed lines in the figure. Fig. 2 is a diagrammatic longitudinal section, seen from above, through the shell structure according to Figure 1, in which shell structure a form with an edge enclosure is indicated by dashed lines. An additional shell, with sealing layer, supporting layer and distance pieces, is also shown diagrammatically by means of dashed lines. Fig. 3 shows from the side and on larger scale a first embodiment of the distance pieces shown in Figure 1 by dashed lines, a further embodiment with a number of rows of meshes being shown by dashed lines. Fig. 4 is a diagrammatic side view of the distance piece according to Figure 3.

DETAILED DESCRIPTION OF EMBODIMENT

With reference to Fig. 1 and Fig. 2, parts of a prefabricated shell structure 1 for installation in a building construction according to the present invention are shown diagrammatically in side view and in longitudinal section. The prefabricated shell structure 1 comprises at least two shells 2, 3 which are arranged at a distance from one another by means of load-bearing distance pieces 4 which separate the shells 2, 3 and form an interspace 5 between the shells 2, 3. Certain components below, which can occur in additional sets, have been marked by dashed lines in the figures and are indicated below in some places by means of marking with a ', for example 3' for an additional shell in addition to the first two shells 2, 3. It is clear therefore that the number of the various components which can occur in additional sets is not limited by the number of the figures indicated. The distance pieces 4 are arranged in the minimum number and type necessary for transport, handling and installation of the finished shell structure 1 and in such a manner that subsequent introduction of any insulation, supplementary reinforcement, items for embedment etc. is facilitated (not shown). This means, for example, that the distance pieces 4 are arranged within certain limited longitudinal and transverse zones 6, 7 distributed over the surfaces of the shells 2, 3, which zones 6, 7 suitably extend between opposite edges 8, 9, 10, 11 of the shell structure 1 with a preferably straight extent. The number of distance pieces 4 necessary for the shell structure 1, their type and distribution may, however, also be defined by any further preparation of the shell structure 1 after installation in the building construction (see below).

The embodiment shown in the figures consists of just such a shell structure 1 which is preferably intended to be completed, for example by casting-in of the interspace 5 between the shells 2, 3, to form a finished structural element after its installation in said building construction, and in which finishing the shell structure 1 is used as a form 12 which is left behind as part of the finished structural element, that is to say that the shell structure 1 constitutes what is known as permanent formwork. However, it is also possible in certain installations for the shell structure 1, with regard to its intended primary function, to be delivered essentially complete, that is to say that, for example, casting-in of the interspace 5 is not necessary.

Here, the shell structure 1 consists in particular of a shell wall/shell wall form comprising two plane and preferably rectangular shells 2, 3, an inner shell and an outer shell, which are arranged at a distance from one another by means of a number of distance pieces 4 (indicated in dashed lines in Figure 1) for forming an interspace 5. The interspace 5 consists essentially of an empty space, apart from the distance pieces 4 bridging the interspace 5, which interspace 5 is normally open outwards along all the edges 8, 9, 10, 11 of the shell structure 1. The shell structure 1 can also be closed along parts of or along all said edges 8, 9, 10, 11, for example in the particular case in which the shell structure 1 is intended to be delivered as an essentially finished structural element.

Any insulation, supplementary reinforcement, items for embedment, enclosures, cables, pipes, ventilation ducts and other installations which it is desirable to premount before final installation of the shell structure 1 in the building construction concerned can be arranged in the abovementioned interspace 5 (not shown). The insulation in the interspace 5, which can also, or preferably instead, consist of an inner and/or outer insulation (not shown) arranged on the outer sides 13, 14 of the shell structure 1, preferably consists of relatively rigid insulating panels of the cellular plastic type or of relatively hard mineral wool panels, but more flexible insulation such as fibre- glass insulation from a roll can of course also be used.

The distance pieces 4 are suitably manufactured from mesh material 16 (see Figure 3), such as preferably reinforcing mesh or other netting of the wire netting, expanded metal etc. type, in the form of narrow bands 15, which comprise only one row of meshes, that is to say netting openings 17, or of broader strips 15' which comprise a number of parallel rows of netting openings 17 (dashed in Figure 3). The mesh material 16 is shaped, for example bent, to form a distance piece 4 with a closed (see Figure 4) or open cross-sectional profile 18. The distance pieces 4 provide, in interaction with other edge enclosures 19 mounted in the form and any openings etc., the necessary bearing capacity during casting of the additional shell(s) 3 on top of the first shell 2. Moreover, the distance pieces 4 afford the necessary strength for storage, transport and handling of the shell structure 1 on the way to the site for and during installation to form a building construction and for completing the shell structure 1 to form a finished structural element, for example by filling said interspace 5 between the shells 2, 3 with additional concrete. In the embodiment shown, the distance pieces 4 comprise, in relation to a plane horizontal form base 12, 20, a number of essentially vertical first bars or wires 21 and, connected to these at a given angle to the first bars or wires 21, essentially horizontal second bars or wires 22, 22' for forming a network 16 with a number of openings 17 which afford an opportunity for the concrete to flow out and also for running any installations through the distance pieces 4.

The shells 2, 3 making up the shell structure 1 normally comprise reinforcement (not shown) in the form of mainly reinforcing mesh, but each shell 2, 3 can of course comprise additional locally mounted individual reinforcement or strengthening zones of additional supplementary reinforcement, for example at openings or the like (not shown).

Before the casting of the second shell half 3, no fixing of the distance pieces 4 is required as the upper form half 3 lies firmly anyway on account of the geometrical shape of the distance pieces 4 with an extent which is greater than the height of the distance piece 4, that is to say, in the case of rings made of reinforcing mesh strips 15', the width of the cut reinforcing mesh strips 15'. Extra plates, binding to the reinforcing mesh of the shells 2, 3 etc. for bracing the distance pieces 4 so that they do not fall over during casting of the first shell 2 are normally no longer required as the distance pieces 4 are inherently stable.

The great loading to which shell structures 1, for example permanent shell wall forms, are subjected during completion to form a finished wall element by in situ casting, that is to say when the interspace 5 of the shell structure 1 between the shells 2, 3 is filled with concrete, leads to the reinforcement in and, if appropriate, between the shells 2, 3 having to comprise special strengthening means for preventing separation of the shells 2, 3 in the direction away from one another. In the embodiment shown in Figure 3, the distance pieces 4 therefore comprise end hooks 23 which are suitably bent towards the centre of the distance piece 4. In other embodiments (not shown), use is instead made of plates, or the distance pieces 4 are attached to the reinforcement forming part of the second shell 3 before the latter is cast.

The shell structure 1 also comprises a sealing layer 20, 20' for each shell 3, 3' in addition to the first cast 2 for use as a casting base during casting of said additional shells 3. The sealing layer 20 can suitably be penetrated, for example by the free ends 23 of the distance pieces 4, without tears occurring in the sealing layer 20 on account of this. In the embodiment shown in Figure 2, the sealing layer 20 is flexible and therefore arranged on top of a supporting layer 24 of mesh reinforcement which in turn is arranged on each of the distance pieces 4. In other embodiments (not shown), the sealing layer has sufficient rigidity so as itself to support a shell 3 together with the distance pieces 4. The sealing layer 20 preferably consists of a nonwoven fabric of the geotextile fabric type, but essentially any layer which has the necessary tightness to retain green concrete can be used, for example insulating panels, plastic, waxed paper such as cardboard for liquids, rubber cloth, metal foil, sheet metal etc. or combinations thereof.

Lastly, the shell structures 1 can comprise items for embedment such as cables, pipes, ventilation ducts etc. and large enclosures 19 or small recesses for openings running through the entire shell structure 1, such as doors, windows, and other openings for telecommunications, electricity, water, drainage, ventilation, or fewer than all the shells, that is to say through only the inner shell 2 or the outer shell 3, 3' and, if appropriate, through one or more of any intermediate shells 3 a present. DESCRIPTION OF FUNCTIONING

With reference to Fig. 1 and Fig. 2, the method according to the invention for manufacturing a prefabricated shell structure 1 for installation in a building construction is described in outline below.

In the implementation method shown in particular in the figures, the manufacture of a shell structure 1 is shown, which structure comprises two plane, rectangular shells 2, 3. It is also possible, however, to manufacture a shell structure 1 with additional shells 3' (see dashed line indication in Figure 2), in which case at least one shell constitutes an intermediate shell 3a. The shells 2, 3, 3' can also be manufactured with a different appearance by arranging distance pieces 4 of different length in a form 12 with a shape which is different from the rectangular, plane shape shown. The shells 2, 3, 3' manufactured can therefore be manufactured with at least one side domed or curved and/or with integrated stiffening means in the form of, for example, beams or columns.

Manufacture is started by laying-out taking place of those features of the shell structure 1 extending through a number of shells 2, 3, and the individual components in the first shell 2, for example its reinforcement, on top of a form 12 arranged essentially horizontally and displaceably in a manufacturing line, after which form edges 8, 9, 10, 11 and other enclosures and openings 19 are installed according to said laying-out in the same work station or after transfer of the form 12 to the next work station along the manufacturing line. Any reinforcement (not shown) in the first shell 2, comprising mesh reinforcement and supplementary reinforcement, is mounted using conventional distance pieces in order to obtain the necessary covering layer. Any items for embedment are also installed in conjunction with this. Said transfer between individual work stations takes place between each manufacturing stage and the next or when deemed suitable with regard to the number of fitters and the nature of the manufacturing installation.

The laying-out and installation of features arranged through a number of shells 2, 3, for example enclosures and hollows 19 for through-openings, for example doors, windows etc., is performed directly before casting of the first shell 2 on top of the form surface 12 and therefore does not also have to be done for all the subsequent shells 3. This is in contrast to previous conventional manufacture of shell structures where the various shells are manufactured separately and are assembled only after the necessary setting with the associated time loss as described above. However, laying-out for the components arranged separately in subsequent shells 3 still takes place later. The distance pieces 4, which are suitably prefabricated and stored at a suitable location along the manufacturing line, are preferably mounted within defined reinforcement zones 6, 7 for subsequently facilitating installation of any additional supplementary reinforcement and other components which it may be desired to integrate in the interspace(s) 5 formed between the shells 2, 3 after or in conjunction with the installation to form the building construction concerned. The first shell 2 is then cast, preferably using conventional concrete or fibrous concrete. Alternatively, the distance pieces 4 can be placed in their predetermined positions after casting as they are easily pressed down into the green cast mass.

During the manufacture of the distance pieces 4, these are manufactured in desired geometrical shapes preferably from pieces of reinforcing mesh, wire netting, expanded metal etc. 16 as above, which are suitably cut into elongate bands 15 or strips 15' and are then shaped, for example cut, bent, sheared and/or welded etc., into different con- figurations, preferably by the ends of said bands 15 or strips 15 ' being joined together end to end so that closed geometrical shapes are obtained.

After casting of the first shell 2 has been completed and any vibration of the form 12, a sealing layer 20 is arranged above and at a distance from the shell 2 cast first, which sealing layer 20 serves as a casting base for the next shell 3, on and between the load- bearing distance pieces 4, which separate the shells 2, 3, and the edge enclosures 19 of the form 12, after which a new, second shell 3 is cast on top of said sealing layer/casting base 20. The second and all additional shells 3, 3' are therefore cast above the first shell 2, which casting can take place at a much earlier point in time in the manufacturing process of the shell structure 1 compared with conventional manufacture, as the preceding shells 2 do not have to set or be lifted before the next shell 3 is cast.

In the embodiment shown in Figure 2, an essentially horizontal, plane supporting layer 24 is mounted on the edge enclosures 8, 9, 10, 11 of the form 12 and/or the distance pieces 4 and thus over the area enclosed by said edge enclosures 8, 9, 10, 11 before the arrangement of the sealing layer 20. The sealing layer 20 is then held away and at a distance defined by the supporting layer 24 and the distance pieces 4 from the shell 2 cast first. In the same way as previously for the form 12, the sealing layer 20 and the supporting layer 24 can be shaped so that a casting base 20 is produced with a slightly different appearance from the embodiment shown in Figure 2 by arranging distance pieces 4 of different length on a supporting layer 24 or sealing layer 20 with a shape which is different from the rectangular, plane shape shown. The shells 3, 3' which are manufactured in addition to the shell 2 manufactured first can therefore also be manufactured with at least one side domed or curved and with integrated stiffening means in the form of, for example, beams or columns (not shown).

After the necessary setting of the shell structure 1, the shell structure 1 is stored or transported to the building construction concerned, where the shell structure 1 is installed, if appropriate after being completed with additional components, and is finished to form the intended structural element, preferably by casting-in the interspaces 5 between the shells 2, 3.

In this in situ casting to form a finished structural element, a floor form, for example, is connected to a shell wall form, after which casting is carried out in both the interspace of the shell wall and the floor simultaneously.

ALTERNATIVE EMBODIMENTS

The invention is not limited to the embodiment shown but can be varied in various ways within the scope of the patent claims.

The shells 2, 3 which make up the shell structure 1 according to the invention, that is to say the inner shell 2 and the outer shell 3, but also any intermediate shells 3 a, preferably consist of plane concrete slabs which are thin in relation to their area and to the thickness of the shell structure 1 as a whole, but curved or domed shells, or shells with a profiled cross section and/or longitudinal section over all or parts of the area of the shell, also fall within the inventive idea. The shells 2, 3 etc. are preferably manufactured from conven- tional concrete with conventional concrete qualities for shell structures 1, but can also be manufactured from what is known as fibrous concrete. Fibrous concrete contains a great many small lengths of fibre, made of, for example, metal, plastic or glass etc. The intention is to increase the strength in the wall, for example its impact strength, and also to afford an opportunity for designing and manufacturing a thinner shell structure 1 than previously.

A positive environmental effect is also obtained as a number of shell structures 1 can be transported, calculated per square metre, on each truck. Extra advantages can also be obtained if states with high impact strength are used in manufacture in the factory. For in situ casting, self-compacting concrete can be used, as a result of which no vibration is necessary. The manufacture as described above preferably takes place to a great extent along a manufacturing line, prefabricated shell walls intended for wall casting with permanent formwork preferably being manufactured. However, this does not exclude any other shell structures 1 which can be manufactured according to the present invention method, such as various forms of floor, support constructions for taking up, for example, earth or water pressure, for installations in the form of quays, bridges etc. Nor is the application of the invention limited only to constructions which, in someway apart from said installation, essentially have to be finished before their intended primary function is achieved, for example constituting a bearing and/or separating wall element. Here, "essentially finished" does not therefore mean painting, papering or similar measures not essential for the bearing and/or separating function.

The thickness of the finished shell structure 1 normally plays a minor role as the shells 2, 3 etc. have essentially the same thickness irrespective of said thickness. For thicker shell structures 1, the length of the distance reinforcement 4 instead is changed so that the interspace 5 is enlarged. The invention is therefore in no way limited to the embodiment shown in particular, but any other configuration as above falls within the inventive idea.

It is clear that the number, size, material and form of the elements and components form- ing part of the shell structure 1, for example the distance pieces 4, is adapted according to the requirements existing at the time. Said geometrically shaped distance pieces 4 can of course consist of, for example, distance pieces 4 with a cross section of open shape, for example with the shape of an S, U etc., of distance pieces with a closed shape, for example circular, oval, rectangular, triangular, star-shaped etc., or of combinations of both closed and open cross sections, for example Φ, φ etc. The important aspect is that, on account of their geometrical shape, the distance pieces 4 can easily take up shear forces in all directions in the plane of the shell structure, but also pressure and tensile stresses in the axial direction of the distance piece 4. The distance pieces 4 can also be positioned in a number of sets 4, 4' one above another if the shell structure 1 comprises more than two shells 2, 3, 3 ' etc.

Claims

PATENT CLAIMS 1. Method for manufacturing a prefabricated shell structure (1) for installation in a building construction, which prefabricated shell structure (1) comprises at least two shells (2, 3), which shells (2, 3) are arranged at a distance from one another by means of load-bearing distance pieces (4) separating the shells, the distance pieces

(4) being mounted against an essentially horizontally arranged form (12) in a number and type necessary for transport, handling and installation of the finished shell structure (1), and the first shell (2) being cast against said form (12) preferably by means of concrete either before or after the mounting of the distance pieces (4), characterized in that a sealing layer (20) which forms a new casting base is arranged on and between the distance pieces (4) and the edge enclosures (19) of the form (12) and at a distance from the previously cast shell (2), after which a new shell (3) preferably consisting of concrete is cast on top of this sealing layer (20).

2. Method for manufacturing a shell structure (1) according to Claim 1, character i z e d in that a supporting layer (24) is arranged on the edge enclosures (19) of the form (12) and/or the distance pieces (4) and over the area enclosed by said edge enclosures (19), and in that said sealing layer (20) is held away and at a distance defined by the supporting layer (24) from the shell (2) cast first.

3. Method for manufacturing a shell structure (1) according to Claim 1 or 2, characterized in that additional sealing layers (20' etc.) are arranged on and between the distance pieces (4) and the edge enclosures (19) of the form (12), above and at a distance from previous sealing layers (20, 20' etc.) and from a cast shell (2, 3) located under each sealing layer (20, 20' etc.), and in that a new shell (3,3') is cast preferably from concrete on top of each additional sealing layer (20') between each new arrangement and the next of an additional sealing layer (20').

4. Method for manufacturing a shell structure (1) according to either of Claims 2 or 3, characterized in that additional supporting layers (24' etc.) are arranged on the edge enclosures (19) of the form (12) and/or the distance pieces (4) and over the area enclosed by said edge enclosures (19), and in that a sealing layer (20, 20') is held away and at a distance defined by the supporting layer (24, 24') concerned from the shell (2) cast first.

Method for manufacturing a shell structure (1) according to any one of Claims 2, 3 or 4, characterized in that a number of distance pieces (4') are arranged from each future intermediate shell (3 a) before an additional new supporting layer (24') and/or sealing layer (20') is arranged on these additional distance pieces (4') and the edge enclosures (19) of the form (12) before the casting of an additional shell (3') on top of said additional sealing layer (20').

6. Method for manufacturing a shell structure (1) according to any one of the preceding claims, characterized in that at least one, some of or all the shells (2, 3, 3') are reinforced before casting and/or in that fibrous concrete is used for casting.

7. Method for manufacturing a shell structure (1) according to any one of the preceding claims, characterized in that the shells (2, 3, 3') are manufactured with at least one side domed or curved and/or with integrated stiffening means in the form of, for example, beams or columns.

8. Method for manufacturing a shell structure (1) according to any one of the preceding claims, characterized in that the shell structure (1) is completed to form a finished structural element by being used, after installation, as a permanent form into which concrete or fibrous concrete is introduced for casting together with an already existing element or structural part and/or with an element or structural part which is cast simultaneously.

9. Method for manufacturing a shell structure (1) according to any one of the preceding claims, characterized in that the distance pieces (4) are manufactured from mesh material (16).

10. Prefabricated shell structure (1) comprising at least two shells (2, 3, 3' etc.), which shells (2, 3, 3' etc.) are arranged at a distance from one another by means of distance pieces (4, 4' etc.), characterized in that the shells (2, 3, 3') consist of shells (2, 3, 3 ') cast previously and subsequently in relation to one another and in this connection one above another, in that the shell structure (1) also comprises at least one sealing layer (20, 20'), which sealing layer or layers (20, 20') is or are aπanged on and between the distance pieces (4, 4') and the edges (8, 9, 10, 11) of the shell structure (1) and at a distance from a previously cast shell (2), and which sealing layer (20, 20') constituted a new casting base during casting of a shell (3, 3,

3') cast subsequently in relation to the previously cast shell (2) and on top of this sealing layer (20, 20').

1. Prefabricated shell structure (1) comprising at least two shells (2, 3, 3' etc.), which shells (2, 3, 3' etc.) are aπanged at a distance from one another by means of distance pieces (4, 4' etc.), characterized in that the shell structure (1) is manufactured according to any one of the method claims 1-9.