SE517246C2 - Shell construction and method for manufacturing said shell construction - Google Patents

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

25 30 35 ou ø u nu vn ~ unu en For example, in the traditional manufacture of, for example, shell wall molds intended for continuous molding, the shells included in the shell construction must be cast separately, whereupon the shells either, after a required hardening has taken place for the separate shells , facing each other and assembled by means of, for example, welding to the described shell construction comprising at least two shells arranged at a distance from each other or a first shell is first cast which after required curing must be applied to a freshly cast and not yet hardened shell to achieve said shell construction.

The reinforcement between the shells, which is used in traditional shell constructions, for example in the form of reinforcement baskets, reinforcement ladders and / or individual reinforcement irons, constitutes an obstacle to later installation of piping, ventilation drums, insulation, etc. as this reinforcement is normally either spread over or over a large part of the surface of the shell construction or in the form of a surface between the shells zoning longitudinal, transverse and / or intersecting reinforcement panels, for example in the form of said ladders and baskets, which in said way constitute obstacles. The shells are connected to each other via the reinforcement so that the shell construction can take up loads during transport, handling and assembly, for example by welding and / or nailing the relevant shells' reinforcements to each other, which is complicated and time consuming.

The exposure of all dimensions and positions of the shell in question to the details included, which details include, for example, recesses and recesses for doors, windows, cavities, telecommunications, electricity, water, drains, etc. must be carried out once for each shell included in the shell structure. This is both time and labor consuming and if errors occur in the release, this will seriously complicate or completely make it impossible to join the individual shells to each other, as the shells will then not fit together. It is also understood that the handling of the individual shells, for example a wall shell, at the described joining to a shell wall is both complicated and risky as the shell due to its own weight, incomplete hardening and / or its deficient strength when the shell is not handled in it with other shell joined state easily breaks.

Due to the complicated reinforcement between the shells, extra reinforcement is usually fitted before the prefabricated shell construction is cast. Any insulation must also be mounted on the outside of the shells for the same reason. It is thus a wish that this extra reinforcement, possible insulation and other details, for example in the form of ventilation, pipes and wiring, should be able to be carried out in a simple manner at the site opening after installation to the current building construction.

OBJECT OF THE INVENTION AND ITS FEATURES An object of the present invention is to provide a method for manufacturing a prefabricated shell structure or assembly in a building structure and a prefabricated shell structure made according to said method, which method and shell structure substantially reduces or completely reduces the Favorable effects for construction can be utilized in a better way than before. cast on top of this waterproofing layer.

The shell structure according to the invention is characterized in that the shells are comprised of, in relation to each other, earlier and later and thereby cast shells, that the shell structure further comprises at least one sealing layer, which sealing layer or layers are arranged at and between the distances and the shell structure edges and at a distance fi -on a previously cast shell and which sealing layer formed a new casting base during the casting of a later cast shell in relation to the previously cast shell on top of this sealing layer.

According to further aspects of a method according to the invention: That a carrier layer is arranged at the edge closures and / or the distances of the casting mold and over the surface enclosed by said edge closures and that said sealing layers are kept by and at a bearing-fixed distance from the first cast shell.

That additional sealing layers are arranged at and between the distances and the edge closures of the casting mold, above and at a distance from previous sealing layers and from a cast shell located below each sealing layer and that a new shell is cast of preferably concrete on top of each additional sealing layer between each new arrangement of an additional sealing layer. That additional support layers are arranged at the edge shut-off rings and / or the distances of the mold and over the surface enclosed by said edge shut-offs and that a sealing layer is kept by and at a distance determined by the current support layer from the first cast shell.

That distances are arranged from each future intermediate shell before an additional new support layer and / or are arranged at these additional distances and the edge closures of the casting mold before the casting of an additional shell on top of the said additional. used for casting.

That the shells are manufactured with at least one side arched or curved and / or with integrated stiffeners in the form of, for example, beams or pillars.

That the shell construction is completed into a finished building element by using it after assembly as a permanent casting form in which concrete or reinforced concrete is applied for joint casting with an already significant element or component and / or with an element or component that is cast simultaneously.

That the spacers are made of mesh material.

According to further aspects, a shell construction according to the invention applies: That the shell construction is manufactured according to one of the method requirements.

ADVANTAGES OF THE INVENTION: A factory for the manufacture of traditional shell structures according to previous methods is very expensive to build. A corresponding factory for production according to the new production method is significantly cheaper and the cost is estimated at only about 20 percent of the previous construction food. 10 15 20 25 30 35 517. 246 »- In addition, the new method described in more detail below is much faster and cheaper than previous methods. This is possible because, for example, no welding is needed between the different shells of the shell structure. The setting, mounting and arranging of recesses, shut-offs, spacer reinforcements, etc. for a shell construction comprising, for example, two separate shells is almost halved, as these measures only need to take place for substantially the first cast shell. The risk that the recesses, etc. previously arranged for each shell separately will not fit together at the joint joint is thus completely eliminated.

In addition, additional piping and cabling, ventilation, etc. can easily be done out on the construction site in connection with the assembly of the shell structure to the current building structure between the zones of spacer reinforcement which were arranged in the manufacture of the prefabricated shell structure.

LIST OF FIGURES The invention will be described in more detail below with reference to the accompanying figures therein: Fig. 1 is a schematic side view of parts of a shell structure according to the present invention for assembly and later completion to finished building element in a building structure, which shell structure comprises two shells are arranged at a distance from each other by means of a number and in the line L-marked distances.

Fig. 2 is a schematic longitudinal section seen from above through the shell construction according to Fig. 1 and in which shell construction a mold with edge closure is dashed. An additional shell with a sealing layer, carrier layer and spacers is also shown schematically by means of line marking.

Fig. 3 shows from the side and on a larger scale a first embodiment of the distances shown in Figure 1 with bar marking, a further embodiment with your rows of stitches being shown in line marking.

Fig. 4 is a schematic side view of the distance according to Figure 3. 10 15 20 25 30 35 .s1 1 see rz ~ 4 pcs. o. c u av s.

DETAILED DESCRIPTION OF EMBODIMENT Referring to Figs. 1 and Figs. 2 is shown schematically in side view and in longitudinal section parts of a prefabricated shell structure 1 for mounting in a building structure according to the present invention. The prefabricated shell structure 1 comprises at least two shells 2, 3, which shells 2, 3 are arranged at a distance from each other by means of load-bearing and the shells 2, 3 separating spacers 4 from the formation of a space 5 between the shells 2, 3. Some details below, which may occur in additional sets, have been marked with dashed lines in the fi gurema and are given below in some places by means of '- marking, for example 3' for an additional shell in addition to the first two shells 2, 3. It is thus understood that the number for the different details which may occur in additional sets not limited by the number of numbers entered.

The distances 4 are arranged in a minimum number and design of at least one transport, handling and assembly of the finished shell construction 1 and in such a way that later introduction of any insulation, supplementary reinforcement, castings etc. facilitated (not shown). This means, for example, that the distances 4 are arranged within certain limited longitudinal and transverse zones 6, 7 distributed over the surfaces of the shells 2, 3 and which zones 6, 7 suitably extend between the opposite edges 8, 9, 10, 11 of the shell construction 1 with a preferably straight stretch. However, the number of spacers 4 required for the shell structure 1, their appearance and distribution can also be determined by a possible and after installation in the building structure further preparation of the shell structure 1, see further below.

The embodiment shown in the figures consists of just such a shell construction 1 which is preferably intended to be completed, for example by casting in the space 5 between the shells 2, 3, to a finished building element after its mounting in said building construction and in which the finishing shell construction 1 is used as a mold 12 which is left as part of the completed building element, i.e. that the shell construction 1 constitutes a so-called lingering form. However, it is also conceivable that the shell construction 1 in certain installations, with regard to its intended main function, is delivered substantially complete, ie. that, for example, a casting of the gap 5 is not needed.

The shell construction 1 here in particular consists of a shell wall / shell wall shape, which comprises two flat and preferably rectangular shells 2, 3, an inner and an outer one, which are arranged at a distance from each other by means of a number of spacers 4 (dashed lines). in fi gur 1) to form a gap 5. The gap 5 consists essentially of a tower ruin, apart from the spacers 4 bridging the gap 5, which gap 5 is normally open outwards along all edges 8, 9, 10, 11 of the shell structure 1.

The shell structure 1 can also be closed along parts of or along all the mentioned edges 8, 9, 10, 11, for example in the special case where the shell structure 1 is intended to be delivered as a substantially finished building element.

In the above-mentioned spaces, any insulation, supplementary reinforcement, casting material, shut-offs, cables, pipes, ventilation ducts and other installations which are desirable to pre-assemble before the final assembly of the shell structure 1 in the current building structure can be arranged (not shown).

The insulation in the space 5, which can also, or preferably instead, be comprised of an inner and / or outer insulation (not shown) arranged on the outer surfaces 13, 14 of the shell structure 6, is preferably comprised of stiffer cellular plastic sheets or of harder mineral wool sheets, but also insulation such as glass fi insulation from roll can of course be used.

The spacers 4 are suitably made of meshed material 16, see Figure 3, such as preferably reinforcing mesh or other network of the type of fencing mesh, stretcher, etc., in the form of narrow bands 15, which comprise only a row of meshes, i.e. net openings 17, or of wider strips 15 'comprising fl your parallel rows of net openings 17 (dashed in fi gur 3). The netted material 16 is formed, for example bent, into a spacer 4 with closed, see 4 gur 4, or open cross-sectional profile 18. The spacers 4 in cooperation with the other edge closures 19 and any recesses etc. provided in the mold provide a required bearing capacity during the casting of the the additional shells 3 on top of the first shell 2. In addition, the spacers 4 provide the required strength for storage, transport and handling of the shell structure 1 to the site before and during the actual assembly to a building structure and for the completion of the shell structure 1 to a finished building element, e.g. to fill the said space 5 between the shells 2, 3 with additional concrete. The spacers 4 in the embodiment shown comprise, in relation to a planar horizontal mold bottom 12, 20, a number of substantially vertical first struts or wires 21 and with these, at a certain angle to the first struts or wires 21, connected, substantially horizontal second struts or wires 22, 22 'for forming a net 16 with a number of openings 17, which provide an opportunity for 10 15 20 25 30 35 onou n. ø n. o .o the concrete to surface and also for pulling any installations through the spacers 4.

The shells 2, 3 included in the shell construction 1 normally comprise reinforcement (not shown) in the form of mainly reinforcement mesh, but of course each shell 2, 3 may comprise additions of locally mounted single reinforcement or reinforcement zones of additional supplementary reinforcement, for example at recesses or the like (not shown). ).

Prior to the casting of the second shell half 3, there is no need to increase the distances 4 as the upper mold half 3 is still stable due to. the geometric shape of the spacers 4 with a spread which is greater than the height of the spacer 4, i.e. in the case of rings made of reinforcing mesh strips 15 ', the width of the cut reinforcing mesh strips 15 ,.

Extra washers, sewing in the shells 2, 3 reinforcement nets etc. for supporting the spacers 4 so that they do not tip over when casting the first shell 2 are normally no longer needed as the spacers 4 are stable in themselves.

The large load to which shell structures 1, for example remaining shell wall forms, are subjected during completion to a finished wall element by casting in place, ie. when the space 5 between the shells 5 between the shells 2, 3 is filled with concrete, leads to the reinforcement in and possibly between the shells 2, 3 should include special reinforcements to prevent separation of the shells 2, 3 in the direction from each other. In the embodiment shown in Figure 3, therefore, the spacers 4 comprise end hooks 23 which are suitably bent towards the center of the spacer 4. In other embodiments, not shown, washers are used instead or the spacers 4 are attached to the reinforcement included in the second shell 3 before this is cast.

Furthermore, the shell construction 1 also comprises a sealing layer 20, 20 'for each shell 3, 3' in addition to the first cast 2 for use as the casting base in the casting of said further shell 3. The sealing layer 20 is suitably penetrable, for example by the free ends 23 of the spacers 4, without that tears therefore occur in the sealing layer 20. In the embodiment shown in Figure 2, the sealing layer 20 is visible and therefore arranged on top of a supporting layer 24 of mesh reinforcement which in turn is arranged at each of the distances 4. In other embodiments not shown, the sealing layer has sufficient rigidity to support a shell 3 together with the spacers 4. The sealing layer 20 is preferably made of a uk bare cloth type geotextile cloth, but essentially any layer which has the required density to retain freshly poured concrete can be used. For example, insulation boards, plastic, waxed cardboard such as so-called liquid board, gurnmiduk, metal foil, sheet metal etc. or combinations thereof.

Finally, the shell structures 1 may comprise castings such as cables, pipes, ventilation ducts etc. and larger shut-offs 19 or smaller recesses for openings running through the entire shell structure 1 such as doors, windows and other openings for telecommunications, electricity, water, drains, ventilation or for less than all. the scale, i.e. through only through the inner 2 or the outer 3, 3 'shell and possibly through one or more of the existing intermediate shells 3a.

FUNCTIONAL DESCRIPTION With reference to Fig. 1 and Fig. 2, the method according to the invention for a manufacture of a prefabricated shell structure 1 for mounting in a building structure is schematically described below.

In the embodiment shown in particular in the fi gures, the manufacture of a shell structure 1 which comprises two flat and rectangular shells 2, 3 is shown. constitutes an intermediate shell 3a. The shells 2, 3, 3 'can also be manufactured with a slightly different appearance by arranging spacers 4 of different lengths in a mold 12 with a different shape than the rectangular, flat shape shown.

Thus, the manufactured shells 2, 3, 3 'can be manufactured with at least one side arched or curved and / or with integrated stiffeners in the form of, for example, beams or pillars.

Production begins with a release of the shell structure 1 through the shells 2, 3 passing the details and the individual details in the first shell 2, for example its reinforcement, on top of a substantially horizontal and in a production line displaceably arranged mold 12, each having mold edges 8, 9, 10, 11 and other shut-offs and recesses 19 are mounted according to said release at the seams or after transfer of the casting mold 12 to the next workstation along the production line.

Any reinforcement (not shown) in the first shell 2, including mesh reinforcement and supplementary reinforcement, is mounted with conventional spacers to obtain the required cover layer. Any cast-in goods are also installed in connection with this.

Said transfer between different workstations takes place between each manufacturing step.

The laying and mounting of details arranged through your shells 2, 3, for example shut-offs and recesses 19 for through-openings, for example doors, windows, etc., is done directly before the casting of the first shell 2 on top of the mold surface 12 and thus does not have to be done for all the subsequent shells 3. This is in contrast to previous conventional production of shell constructions where the different shells are manufactured separately and which are only assembled together after the required curing with a corresponding loss of time as described above. However, later release still takes place for the details arranged separately in the subsequent shells 3.

The spacers 4, which are suitably prefabricated and stored at a suitable place along the production line, are preferably mounted within certain reinforcement zones 6, 7 for later facilitation of any further supplementary reinforcement and other details which are desired to be integrated in the space formed between the shells 2, 3 or in connection with the assembly to the current building construction. The first shell 2 is then cast using preferably conventional concrete or reinforced concrete. Alternatively, the spacers 4 can be placed at their predetermined positions after casting as they are easily pressed into the newly cast casting mass.

In the manufacture of the spacers 4, these are manufactured in desired geometric shapes, preferably pieces of reinforcing mesh, fencing mesh, tension rods, etc. 16 as above, which are suitably cut into elongate strips 15 or grooves 15 'and then formed, for example cut, bent, cut and / or welded, etc., to different configurations, preferably by joining the ends of said strip 15 or strips 15 'together end to end so that closed geometric shapes are obtained.

After completion of casting of the first shell 2 and a possible vibration of the mold 12, a sealing layer 20 is arranged above and at a distance from the first cast shell 2, which sealing layer 20 serves as the casting bottom for the next shell 3, at and between the load receiving and the shells 2 , 3 separating the spacers 4 and the edge closures 19 of the mold 12, after which a new, second shell 3 is placed on top of the adjacent sealing wedge / casting bottom 20. The second, and also all further shells 3, 3 ', are thus cast above the first shell 2, which casting can take place at a much earlier time in the shell construction 1 10 15 20 25 30 35 11 .... .. manufacturing process than compared with conventional manufacturing, as the previous shells 2 do not need to be hardened or lyed before the next shell 3 is cast.

In the embodiment shown in Figure 2, a substantially horizontal, flat support layer 24 is mounted at the edge closures 8, 9, 10, 11 and / or the distances 4 of the mold 12 and thus over the surface enclosed by said edge closures 8, 9, 10, 11 before the arrangement of the sealing layer 20. The sealing layer 20 is thereby kept at and at a distance determined by the support layer 24 and the distances 4 from the first cast shell 2. In the same way as before for the molds 12, the sealing layer 20 and the support layer 24 can be formed so that a casting base 20 is made with a different appearance from the embodiment shown in Figure 2 by arranging spacers 4 of different lengths at a support layer 24 or sealing layer 20 with a shape other than the rectangular, planar shape shown. Thus, even the shells 3, 3 'which are manufactured in addition to the first manufactured shell 2, can be manufactured with at least one side arched or curved and with integrated stiffeners in the form of, for example, beams or pillars (not shown).

After the required hardening of the shell structure 1, the shell structure 1 is stored or transported to the current building structure where the shell structure 1 is mounted, possibly after completion with further details, and completed to the intended building element, preferably by spacing in the spaces 5 between the shells 2, 3.

In this in-situ casting to a finished building element, for example, a floor form is connected to a shell wall shape, after which the casting takes place in both the space of the shell wall and the floor at the same time.

ALTERNATIVE IVA EMBODIMENTS The invention is not limited to the embodiment shown, but it can be varied in various ways within the scope of the claims.

The shells 2, 3 which are included in the shell construction 1 according to the invention, i.e. inner 2 and outer 3 shells but also any intermediate shells 3a, are preferably comprised of flat and in relation to their surface and to the thickness of the entire shell construction 1 thin concrete slabs, but also curved or arched shells, or shells with profiled cross and / or longitudinal sections over all or part of the surface of the shell, falls within the heating tank. The shells 2, 10 15 20 25 30 35 3, etc. are preferably made of traditional concrete with concrete qualities for shell constructions 1, but can also be made of so-called fi reinforced concrete.

Fiber concrete contains a large amount of small fiber lengths, for example of metal, plastic or glass, etc. The intention is to increase the strength of the wall, for example its impact strength and to obtain an opportunity to design and manufacture a thinner shell construction 1 than before. A positive environmental impact is also obtained as sk your shell structures 1 can be transported calculated per square meter of surface area on each truck. Additional benefits can also be obtained if a permit with high impact strength is used in factory production. For self-compacting, concrete that is self-compacting can be used, so no vibration is needed.

Preferably, the manufacture according to the above takes place largely along a production line e, whereby preferably prefabricated shell walls intended for wall casting with remaining shapes are manufactured. However, this does not exclude other shell structures 1 that can be manufactured according to the existing construction method, such as various forms of flooring, support structures for absorbing, for example, soil or water pressure, for facilities in the form of quays, bridges, etc. which in a certain way, in addition to the approximate assembly, must essentially be completed before its intended and main function is achieved, for example constitute a supporting and / or separating wall element. "Substantially completed" thus does not mean painting, wallpapering and the like, not essential measures for the load-bearing and / or separating function.

The thickness of the finished shell structure 1 normally matters less as the shells 2, 3, etc., independently of this thickness, have substantially the same thickness. For thicker shell constructions 1, the length of the spacer reinforcement 4 is changed instead so that the gap 5 increases. The invention is thus in no way limited to the specially shown embodiment, but any other configuration as above falls within the invention concept.

It will be appreciated that the number, size, material and shape of the elements and details included in the shell structure 1, for example the distances 4, are adapted to the requirements which currently exist. Approximately geometrically shaped spacers 4 may of course be comprised of, for example, spacers 4 of cross section with an open shape, for example with the shape of an S, U, etc., of spacers of closed shape, for example circular, oval, 12146 _ 22 :; _ = 13 u '' - rectangular, triangular, stem-shaped, etc. or of combinations of both closed and open cross-sections, for example CD cp, etc. directions in the plane of the shell structure, but also pressure and tensile stresses in the axial direction of the spacer 4. The distances can also be placed in fl your sets 4, 4 ”above each other if the shell construction 1 comprises fl more than two shells 2, 3, 3”, etc.

Claims (1)

A method for manufacturing a prefabricated shell structure (1) for mounting in a building structure, which prefabricated shell structure (1) comprises at least two shells (2, 3), which shells (2, 3) are arranged spacers (4) spaced apart by load-bearing and shells, wherein spacers (4) are mounted against a substantially horizontally arranged mold (12) in a number and design required for transport, handling and mounting of the finished shell structure (1), and against which casting mold (12) the first shell (2) is cast by means of preferably concrete either before or after the mounting of the spacers (4), characterized in that a sealing layer (20) forming a new casting bottom is arranged at and between the spacers (4) and the edge closures (19) of the mold (12) and at a distance from the previously cast shell (2), after which a new shell (3) of preferably concrete is cast on top of this (20). Method for manufacturing a shell structure (1) according to claim 1, characterized in that a support layer (24) is arranged at the edge closures (19) and / or the distances (4) of the mold (12) and over the surface enclosed by said edge closures (19). and that said sealing layer (20) is kept by and at a distance determined by the support layer (24) from the first cast shell (2). Method for manufacturing a shell construction (1) according to claim 1 or 2, characterized in that additional sealing layers (20 ', etc.) are arranged at and between the distances (4) and the edge closures (19) of the mold (12), above and on distance from previous sealing layers (20, 20 ', etc.) and from a cast shell (2, 3') located below each sealing layer (20, 20 ', etc.) and that a new shell (3, 3') is cast by preferably concrete on top of each additional sealing layer (20 ') between each new arrangement of an additional sealing layer (20'). Method for manufacturing a shell construction (1) according to any one of claims 2 or 3, characterized in that additional support layers (24 ', etc.) are provided at the edge closures (19) and / or the distances (4) of the mold (12) and over the surface. which is enclosed by said edge closures (19) and that a sealing layer (20, 20 ') is kept by and at a distance determined by the current support layer (24, 24 °) from the first cast shell (2). Method for manufacturing a shell structure (1) according to any one of claims 2, 3 or 4, characterized in that spacers (4 ') are arranged from each future intermediate shell (3a). before a further new support layer (24 °) and / or sealing layer (20 ') is provided at these further distances (4') and the edge sealing rings (19) of the casting mold (12) before the casting of a further shell (3 ") on top of said further (20 ') ”). Method for manufacturing a shell structure (1) according to any one of the preceding claims, characterized in that at least one, fl era or all the shells (2, 3, 3 ') are reinforced before casting and / or that fi reinforced concrete is used for the casting. 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 arched or curved and / or with integrated stiffeners in the form of, for example, beams or pillars. Method for manufacturing a shell structure (1) according to any one of the preceding claims, characterized in that the shell structure (1) is completed into a finished building element by using it after assembly as a rigid mold in which concrete or concrete is applied for joint casting with an already existing element or built] and / or with an element or building part that is cast at the same time. Method for manufacturing a shell construction (1) according to any one of the preceding claims, characterized in that the spacers (4) are made of welded material (16). 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 each other by means of spacers (4, 4 ', etc. ), characterized in that the shells (2, 3, 3 ') are comprised of, in relation to each other, earlier and later and thereby shells (2, 3, 3') superimposed on each other, that the shell construction (1) further comprises at least one sealing layer (20, 20 '), which sealing layer (20, 20') is arranged at and between the distances (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 toe layer (20, 20 ') formed a new casting base under ll. a n n n o nu 16 u! ini 'i 2 the casting of a shell (3, 3, 3') on top of this sealing layer (20, 20 °) in relation to the previously cast shell (2). 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 each other by means of spacers (4, 4 ', etc. ), characterized in that the shell structure (1) is manufactured according to one of the method claims 1-9