HUE030735T2 - Wall element for building in prefabricated construction - Google Patents

Description

Description

Tile invention relates to a wall ©iámén! designed as a prefabricated concrete component for ©reeling a structure, it relates further to a structure produced using auch wall elements, in particular an operational or plant building of a nuclear power plant.

Safety-related buildings of nuclear plants, for ©Kample the buildings that house the emergency power units, have hitherto been designed almost exclusively as in situ concrete structures. Prefabricated construction, which has bean tried and tested In conventional residential building construction, has hitherto scarcely been used In the nuclear sector owing to the very high load level.

In the nuclear sector, the buiiding/sfructyre must withstand all loads and load combinations from the following events of groups EVI -- internal events ~ and EVA - external events;

Normal operation; - constant loads " variable loads including loads caused by transport and installation - combined loads influences due to external events affecting personnel: - explosion - aircraft crashes - fire in the outdoor area

Influences due to unforeseen internal events; - fire within the plant - collapse of the Internal design ~ falling loads - internal flooding - internal explosion - earthquake - extreme winds - extreme snow and ice - tor nado loads, influence of tornado projectiles ~ extreme external temperatures - external flooding - extreme precipitation - physical protection ~ explosive pressure wave - explosive gas doud

The use of prefabricated components ~ aiibough regarded as wholly desirable because of the associated standardisation and optimisation of the entire planning, building and construction sequences ·» has hitherto encountered considerable difficulties In this context and has therefore not happened, This Is due in particular to the connection techniques hitherto conventional in prefabricated construction, which either do not meet the requirements made in the nuclear sector in terms of load bearing or are not capable of observing the permissible component tolerances which are to be met in said sector and at the same time permitting flexible joints at the construction site end overcoming alignment inaccuracies during assembly,

The fact that, for every nuclear power plant, substantially the same buildings having the same functionality are newly planned leads to the consideration of bow planning and execution costs can be reduced, Ä reduction is possible by means of systems which allow the desired spaces and their layout to be planned flexibly using prefabricated modules. The underlying consideration hare is that the introduction of prefabricated construction hitherto encountered difficulties above all In relation to the diction a! connection between the individual; structurai elements and in terms of overcoming the associated tolerances and dimensional inaccuracies as well as alignment Inaccuracies during assembly. A prior application Of AREVA NR GmbH having publication number WO 2012/123067 At disclosed a wall element of the type mentioned at the beginning which can be put together and joined in a simple manner with further such wall elements to form a structure, especially a building or building complex, which is not only designed for conventional operating loads but additionally also withstands improbable extreme loads ~ individually or even in combination - for instance flooding, earthquakes, incessant rain, ice toads, wind loads, whirlwinds, extrema ambient temperatures, projectile impact, aircraft crashes, etc.

According to that application there is provided a wall element - referred to therein as a wall module * Which. ι$· m the form of a prefabricated concrete component for erecting a structure having a wail body, which well element has a plurality of reinforcing rods which, as a whole, form a regular reinforcement grid, preferably extend in each case parallel to the edges of the wfa!l body and are sealed Into the wall foody, at least some of the reinforcing rods passing through the wall foody substantially from edge to edge in each case and being provided at their ends with connecting elements which are designed to produce a connection with complementary connecting elements of an immediately adjacent wall element. The respective connecting element ~ in any case in the detached state net connected to a complementary connecting element ~ is connected to the associated reinforcing rod with clearance or in a movable manner such that it is displaceable In & plane which is at right angles to the longitudinal direction of the reinforcing rod on ail sides by at least 2 millimetre® in relation to an intended central position.

There has further been described as a preferred embodiment a wali element in which the wall body has an outer shell, ah inner shell and a core filling therebetween, in the manner of a sandwich structure, the cuter shall and the inner shell being connected together in a shear-resistant and high-tensile manner by reinforcing elements. However, this basic concept of the sandwich structure has not been specified further therein as regards possible embodiments.

This is the starting point of the present invention, the object of which is to develop further the wall elements described in the mentioned prior application. There is to be formád a solid reinforced concrete structure, prefabricated in a modular manner, of reinforced concrete slabs and joint connecting elements which, after connection of the Individual elements, as a monolithic unit, bears the high load level under the various load cases mentioned at the beginning. There is to be created in particular a reinforcement structure for the reinforced concrete slabs and for the joint connections which can be constructed with an acceptable outlay and is designed for the mentioned requirements, in addition, the joints which are present when the wall elements are pieced together and which ere to foe cast with in situ concrete or another filling material — for example mortar -* are to have as small a volume as possible so that only a small amount of in situ concrete and formwork material is required at the construction site.

According to the invention, the object is achieved foy the features of claim 1.

Advantageous further developments and concrétisations of the basic principle will become apparent from the dependent claims and also from the following detailed description of an embodiment In the figures, in each case in a: simplified and schematic representation:

Fig. 1 is a perspective view of a wail element manufactured in a sandwich structure, having an inner shell, an outer shell and a core filling,

Fig. 2 Is a perspective view of the structure of the reinforcement of the inner shell of the wall element In an intermediate stage during manufacture,

Fig. 3 is a longitudinal section through the well element.

Fig, 4 is a defali of Fig, 3,

Fig. 6 Is a perspective view of the structure of the reinforcement of the inner shell of the wall element before casting of the concrete mass surrounding the reinforcement,

Fig, 6 is a perspective view of the inner shell of the well element after casting of the concrete mass,

Fig, 7 is a perspective view of the connection between the inner shell and the outer shell of the wail element,

Fig. 8 is a perspective view of the connection between the inner shell and the outer shell of the wail element, the concrete mass of the outer shell having been graphically faded out (or made transparent),

Fs§. 9 is a pian view from above of the connection between the inner sheii and the outer shel! of the wait element

Fig. 10 shows, from top to bottom, in each case in a perspective view, two different intermediate stages in the connection of two waif elements placed side by side,

Fig, 11 shows a further intermediate stage in the connection of two wall elements placed side by side, specifically during casting of the vertical butt joint between the two wait elements.

Fig, 12 is a plan view from the side of a detail of the reinforcement shown in Fig. 2,

Fig. 13 is a perspective view of a detail of the joint reinforcement in the vertical butt joint of two wall elements placed side by side,

Fig. 14 is a cross section through the connection region of two wail elements placed one on fop of the other, and

Fig. IS is a longitudinal section through the connection region of two wall elements placed one on top of the other. in the following, ail positional and direotlonaf information, such as lop", '‘bottom", "vertical”, ’‘horizontal", relate to the usual Installed position of the wali elements shown in the figures.

Fig. 1 shows, ín. a perspective view, a rectangular wall element 2 manufactured in a sandwich structure, for example for use in a nuclear power plant building. The wall element 2, which is provided for arrangement in a side wall of a building and generally terms a complete height between floors, has an inner shell 4 constructed as a reinforced concrete structure, a corresponding outer sheii 6 and a core filling 3. for example of heavyweight concrete, situated therebetween. The Inner shell 4 and the outer shell 8 are almost mirror images of one another and are otherwise of identical construction, es will be further described in; greater detail below. At the top edge, there project from the cuter shall 4 and from the inner shell if a plurality of connection elements 10 for forming screw connections with tne wall element situated fhereabove (net visible here). In a corresponding manner. connection elements that are functionally complementary thereto are arranged on the bottom (hidden here) of the well element 2. in addition, access openings 14 for achieving the screw connections during assembly of the wail element system are present at the bottom in the mgion of the front face 12 of the inner shell 4 and of the outer shell 0. The access openings 14 each extend through the cross section of the inner shell 4 or of the outer shell B In the manner of a channel. At the two lateral edges, reinforcement loops/U-shaped bolts, U-bolte id for short, project with their bent end out of the inner shell 4 and the outer shell 6 of the wall element 2, which loops are provided to form the connections to adjacent wall elements (not visible here). F>g. 2 illustrates the structure of the inner shell 4 of the wall element 2, os it were in a first phase during construction of the Inner reinforcement cage, before the concrete is cast, The wall element shown in the finished state on the right thereof and -also the partially cast joint are to he disregarded for the time being (they are present for reasons of image generation with the aid of a CAD program, individual layers having been selectively faded out of the complete structure). As already mentioned, the outer shell 0 is designed analogously to the inner shell 4.

The mam reinforcement 18, which is also referred to as a bending reinforcement and is designed to absorb and transmit tensile forces in the combination of the wail elements 2, comprises a rectangular grid, which lies in the plane of extension of the wall alement 2, of horizontal reinforcing rods 28 (only the bottom two are shown in Fig, 2) and vertical reinforcing rods 22 which are in contact it the points of intersection, where they are braided with wire, for example, and thus fixed relative to one another. The reinforcing rods 20 oriented horizontally and thus parallel to the top and bottom edges of the wail element 2 are arranged equidistantiy from one another, as are the reinforcing rods 22 oriented vertically and thus parallel to the side edges of the wall element 2, In both cases - horizontally and vertically ~ the rod diameter is preferably about 30 to 35 mm. The distance between the longitudinal axes of the reinforcing reds 2.0, 22 is in both cases preferably about 200 mm (square grid).

Two vertical reinforcing rods 22 which follow one another in the horizontal direction and are each provided with a screw thread at their top end are each screwed into, or alternatively welded in, associated receivers of a connecting piece 24. A connector pin 28 which protrudes upwards from the grid combination and is likewise provided with an external thread 1$ screwed Intő an intermediate eentralrecelver of the connecting piece 24. A holding plate 28 provided with a central opening can be pushed onto the vertically oriented connector pin 28 from above, and a nut 3G can be screwed on above the holding plate, At the bottom endőfíhe-röd pair thus connected together there Is a steel box 32 of rectangular cross section which is composed of four steel plates welded together or alternatively Is cast in one piece, which box is arranged with an accurate tit between the two vertical reinforcing rods 22 and is welded or alternatively screwed thereto on the outside. The arrangement of the connecting pieces 24 and the boxes 32 is chosen such that, when the concrete mass is subsequently oast, they finish flush with the top or bottom edge of the inner shelf 4, sc that only the top portion of the connecter pin 26 protrudes upwards. Furthermore, the boxes 32 are embedded in the concrete such that the box-shaped interior of each box 32 and a substantially box-shaped mounting space immediately above it are left free. The continuous cavity thus formed is accessible both from beneath via the bottom bex opening, which Is left free, and from the front side 12 via the access opening 14. which is likewise left free (see also Fig. 1),

There Is thus formed overall a system of connecting elements 18 by means of which wall elements 2 situated one above the other can be screwed together during subsequent assembly of the structure. To that end, the top wail element 2 is placed on the wail element 2 situated thereheneath such that the top ends of the connector pins 26 of the bottom wall element 2 each pees through the associated boxes 32 of the counterpart element. Then, firough the access openings 14 in the front side 14 of the Inner shell 4 (and analogously in the case of the outer shell 8), the holding plates 28, which laterally overlap the boxes 32 at the top edges thereof, are pushed onto the ends of the connector pins 26 and are secyred/clamped by screwing on and tightening the nuts 30, The holding plates 28 thereby aot, m it were, as washers. The cross section of the boxes 32 Is chosen such that the respective connector pin 28 has a few millimetres of play therein in all directions during assembly, in order thus to compensate for any dimensional Inaccuracies during subsequent assembly at the construction site. This corresponds to the design philosophy already described in International öffm^gungsschrift WO 2012/123887 A1 of AREVA HP GmbH, It should also be noted that, although the holding plates 2$ and the nuts 30, for the sake of clarity, are shown in their final assembled position on the connector pins 2$ in Fig. 1 and Hg. 2, they are in reality only fitted there and tightened cnee the walls have been erected and the respective elements that are to be connected have been joined together,

Back Io the structure of the Inner shell 4 according to Fig, 2, In addition to the main reinforcement 18 there is also provided a surface reinforcement 34 which is likewise in the form of intersecting reinforcing rods 36, 38 having a diameter of about 100 mm which are arranged in the manner of a grid and having the same mesh size as in the case of the main grid (square gnd with a rod spacing of about 206 mm). The grid of the surface reinforcement 34 formed of the horizontal reinforcing rods 38 and the vertical reinforcing rode 38 Is arranged parallel to the grid cf the main reinforcement 18, specifically at a distance therefrom in the direction towards the front side 14 (which is here on the rear side) of the inner shell 4. in the lateral direction, the points of intersection of the two reinforcing grids are preferably offset relative to one another py half a mesh length- The points of intersection of the surface reinforcement 34 thus lie In the centre of the meshes of the main reinforcement 18 and vice versa (see also Fig. 12).

Furthermore, as already mentfonedi outwardly protruding ü-ooífs 18 or (reinforcing) loops of steel are attached to the side edges of the inner shell 4 for the subséquent formation and fixing of the lateral wail element joints. The individual U-bolls 16 hâve two iegs 40 which extend horizontally and parallel to the direction of longitudinal extension of the iafer wail element 2 and which are situated in the gap between the main reinforcement 18 and the surface reinforcement 34 and are preferably in contact with the vertical reinforcing rods 22 of the main reinforcement 18 (at which contact points are together braided with wire), specifically on the side on which the horizontal reinforcing rods 20 ar® also arranged. One seg 40 of the Unbolt 18 iies above the associated horizontal reinforcing rod 20 of the main reinforcement 18, and the other leg lies belőve In other words, each of the horizontal reinforcing rods 20 of the main reinforcement 18 lies in the middle between the two legs 40 of a U-bolt 16 oriented in a coplanar manner (see also Fig. 12). The portions of the lags 40 that ar® situated inside the Inner shell: 4 are kept comparatively long and in the example shown here extend over more than four grid meshes of the main reinforcement is, that is to say over more than 800 to 1000 mm When seen in the horizontal direction, the outwardly projecting portions, including the terminai bend 42, each have a length of preferably about 460 mm. Later assembly and connection In the region of the vertically extending butt joint between two Wall elements 2 will be described in greater detail below.

Finaily, the reinforcement of the inner shell 4 has U-bolls 44 or loops of steel which are bent in a right angle (for example Pent or cast in that foroi), the straight end; 46 of each of which lies in the gap between the main reinforcement 18 and the surface reinforcement 34. The comparatively short leg portions of the straight end 46, which extend over lees than or not more than one grid mesh, lie parallel to the horizontal reinforcing rods 20 of the main reinforcement 18, The bent end 48 of the U-bolts 44 protrudes perpendicularly from the rear side SO opposite the front side 14 and projects into the later core fiiiing 8 by at least 200 mm. The U-boit 44 thereby encompasses/engages behind one of the vertical reinforcing rods 22 of the main reinforcement 18 at the curved or bent point 52, where it is in contact therewith. This can clearly be seen in Fig, 3 and Fig, 4, which show a corresponding longitudinal section through the later wail element 2. In this manner, such a U-boit 44 is associated with at least some meshes, preferably with most meshes, especially with each mesh of the main reinforcement 18. This can be seen In Fig, .§, which shows the complété structure of the reinforcement combination of the Inner sheii 4 shortly before the concrete is poured. Fig, 6 shows the situation after the concrete has been poured.

After the inner shell 4 according to Fig. 6 and an outer shell 6 of corresponding construction have been produced, they are connected together to form a wall element 2 by means of the tbboits 44 projecting into the later core fling 8. To that end, the two shells 4, 8 are brought into the deemed relative position with respect to one another, so that the bent end 48 of a U-OOtt 44 of the inner shell 4 and of a U-boli 44 of the outer shell 8 are situated immediately next to one another and the straight teg portions overlap and touch one another. The bends of the two U~bo)ts 44 thereby encompass a substantially O-shaped opening 54, This can clearly be seen in Fig, ? or Fig, 8, in Fig. 8 the concrete filling of the outer sheii 8 having been graphically faded ouf in order to give a better view. It will also be seen that the U-holts 44 ere arranged 1rs rows, the O-shaped openings 54 or loops of a row being in alignment with one another when seen in the horizontal direction. When seen in the vertical direction, a plurality of those rows lying one above the other are arranged so as to foe distributed uniformly over the full height of the wall element 2 (for the sake of simplicity, only two rows are shown hem). Two reinforcing rods 55 are pushed into each of the rom, which remfoicing rods extend over the full width of the wall element 2 and are oriented hoheontaity accordmg to the bolt arrangement. One reinforcing rod §0- is oriented towards the inner shell 4 in accordance with the free space provided by the O-shaped openings 54 of the bolt arrangement, and the other reinforcing rod is oriented towards the outer shell 6 The reinforcing rods 58 are thereby In contact with the corresponding bends of the U-bolts 44 on the inside at the apexes thereof.

After a If the reinforcing rods 58 have bean introduced info the gap between the inner shell 4 and the outer sheii 8. the core filling 8 is cast. The core filling 8 can be made of heavyweight concrete, it being necessary to take account of any requirements specified in terms of the shielding effect with respect to radioactive radiation. The heavyweight concrete ling is also used for load bearing of the loads (specifically of pressure loads in the element combination). In order to produce a high-quality combination, the concrete surfaces which are connected by the casting are to have a surface that has been freed of grain structures. Concrete is a minerai construction matériái and can he regarded as artificial rook. It consists of a mixture of cement, aggregate and water. Sand, gravel and crushed stone are mainly used as aggregate. It is only added shortly before introduction into the shaping formwork. As aggregate materials for normal concrete there are used predominantly natural materials auch as gravel from deposits or crushed rock (broken rock, oruslmt stone). The aggregate substantially determines the processability and strength of the concrete. By means of a suitable graduation of different aggregate grain sizes, it Is aimed to achieve as dense a packing of the grains as possible with few cavities in which me cement pasta is located. Dense packing permits load bearing m the concrete by means of the grain structure.

After the cere filling 8 has hardened, the combination of the outer shell 8, the core fling 8 and the inner shell 4 shewn in Fig, 1 acts like a monoiiihic object The Inner shells 4 and the outer shells 8 have a wail thickness 8 of in each case preferably at least 240 mm. The thickness T of the core filling is variable. It can vary, for example, between 200 and about 5SÖ mm. Accordingly, the wail element 2 overall has a thickness Ü in the range of from about 700 mm up to 1000 mm or slightly more. See in this connection also the view of the wall element 2 according to Pig. 9. in which the core filling 8 Is net yet present.

Fig. 1Ö shows, from top to bottom, the various steps Involved in joining and connecting two wall elements 2 situated side by side at the construction site. The two wail elements 2 are first brought info the desired position relative to one another, in which the tbbofts 18 at the edges of the inner sheii 4 on the one hand and of the outer shell 8 on the other hand overlap and ere in contact with one another in pairs, The bend of the respective bolt 18 is thereby in contact with the shell edge of the adjacent wall element 2, in other words, the bolt portions projecting from the concrete mass pass through the full width of the vertically extending butt joint 58 between the two wall elements 2. fîlosabia brackets 60 or rails of steel ara than pushed over the paired U-boits 18, In the final assembled state, the brackets 80 each form a closed rectangular frame, the longitudinal members 84 cf which are oriented horizontally and perpendicularly to the grid plane of the main reinforcement 18 (and thus also perpendicularly to the U-boits 18} and the transverse members 68 of which are oriented vertically. The rectangular frame ancioses/ehcornpasses the two associated bolt pairs, situated at the same height, of the inner shells 4 and of the outer shells 6 of two wall elements 2 arranged side by side and is in contact therewith on the outside. There are thereby associated with each boit pair a plurality of brackets 68, here four brackets, which ere situated preferably side by side at the same distance from one another and are oriented parallel to one another (see also Fig. 13}.

In the plan view Of the vertical butt joint 88, it is divided by the Unbolts 18 and the brackets 80 into smaller' rectangular compartments which are In alignment with one another in the direction of vertical extension of the wali element There are thus formed, as it were, vertical part-channels within the joint reinforcement which are delimited with respect to one another and Into which there are Inserted in a further step vertically oriented reinforcing rods 82, in this case three such rods.

Finally, the verticai butt joint 58 thus reinforced, which advanisgeeusiy is not substantially more than 400 mm wide, is cast with concrete, preferably with fine-grained concrete of comparable quality to the concrete cf the Inner shells 4 end outer shells 6 of the wall elements 2 (concrete grade C 50/88 or better), An intermediate stage during the casting operation is shown schematically in Fig, 11. 1 he transmission of tensile forces in the horizontal joint between two wall elements 2 arranged one on top of the other takes piacé as already described by screw connection of the vertical main reinforcement 18.

The horizontal joint 68 (bed joint) between two wail elements 2 which - spaced spart from one another by flat spacers 70 - are placed one on fop of the other Is about 80 mm high and is cast with a high-quality casting mortar after the walls have been erected. The openings for screwing of the connection elements TO are likewise cast for the final state AH the wall elements 2 are immovably connected together in the described manner and as a whole form a shear-resistant structure which has the advantageous properties of a monolithic plate-disc element. Force transmission between the individual components is ensured by specifically designed connections arid joints (high-iensiie and shear-resistant connections}, it goes without saying that numerous variations of the wail elements are possible in order to permit, for example, ceiling joints, T-joints between external and Internal walte, corner connections, etc.

As well as the use of the described wall elements and connection techniques in nuclear power plant building construction, their use in other buildings with similarly high requirements (for example military buildings, industrial plant buildings, etc,') Is of course also possible.

List of reference numerals 2 Wall element 4 Inner shell 8 Outer shell 8 Core filling 10 Connection element 12 Front side (of the respective shell) 14 Access opening 16 Reinforcing ioop/U-boli (lateral joint) 18 Main reinforcement 28 Horizontal reinforcing rod (main reinforcement) 22 Vertical reinforcing rod (main reinforcement) 24 Connecting piece 28 Connection pin 28 Molding plate 30 Nut 32 Box 34 Surface reinforcement 36 Horizontal reinforcing rod (surface reinforcement) 38 Vertical reinforcing rod (surface reinforcement) 40 Leg 42 Bend 44 U-boli (for connecting the shells) 48 Straight end 48 Bent end 50 Rear side 52 Angled portion/curved point 54 O-sh aped opening 58 Horizontal reinforcing rod (core reinforcement} 58 Vertical butt joint 80 Bracket 82 Vertical reinforcing rod (joint reinforcement) 84 Longitudinal member 86 Transverse member 68 Horizontal joint (bed joint) 70 spacer

Claims (10)

LALELEM H HANDICRAFTS FOR BUILDING BUILDING-BASED BUILDING BUILDINGS; L is a prefabricated concrete element (3) for structural construction, comprising a body with a substantially rectangular base area and four edges having an inner shell (4), an outer shell (s), and a core spaced between them according to the construction method. who is charging (8) where. * the inner shell (4) is manufactured in reinforced concrete construction and has a tine reinforcement (IS), which is generally mounted on the test rods (20) parallel to the edges, parallel to the edges, and a vertical reinforcing rod (22) which the shells of the inner shell (4) extend substantially from edge to edge, «the vertical reinforcement bars (22) at their ends are provided with coupling elements (10) to form a screw connection or a tension band with the complementary connecting elements (10) of the above or below element (2) characterized in that: * there is a greater slope in the wall element, respectively a junction (44) having a curved and stem end (46) and an arched end (48) which are molded into the inner shell by its stem end (46). (4), which, when inspired, encircles the respective beam (44) in the area of curvature (52) at the right angle; a vertical reinforcement bar (22) and an arcuate end (48) extending into the protrusion (8), and * the outer shell (6) is constructed in an analogous manner to the inner shell (4), The wall element according to claim 1, wherein the undercut (18) is attached to each of the wrenches (U) (44) extending into the core filling (8). The wall element (2) according to claim L or 2, wherein the inner members (44) of the inner shell (4) and the outer hinge (δ) are L; (44) at their curved ends (481 interleaving each other in pairs, and respectively an O-shaped opening (54), through which at least one horizontal ironing rail (56) is passed through as the component of the molding. 4. Referring to 1-3. of claim 1 (2). having a surface ironing (34) parallel to the ironing (18). A pad (2) according to claim 4, wherein the stem ends {46} of the brackets {44} are positioned between the ironing <18} and the surface reinforcement <RTIgt; ll34 </RTI>. 6. A member (2) according to any one of claims 1 to 3, wherein the lateral adjacent members (2) are connected to the inner shell (4) and the outer shell (6) to form a seam (s) (11) shaped to the side of the bow. 7> Several adjacent villages 12; connecting the wall elements according to claim 6, wherein the reinforcing arms of the adjacent sides (2) of each other (2) overlap each other in a vertical joint (58), and where the inner shell (4) of a multiplier (M) is one a pair of hnrok is joined by a loop pair of external hej (6) The single switch according to claim 7, wherein the at least one vertical reinforcement is provided in the joint (58). (62) 9. Jointing of the wooden elements (2), which are respectively wall elements k> One of the claims is formed by a set of stacked wall elements (2) screwed together or tensioned with each other through the connecting elements (10). A wall element (2) coupled according to claim 9, wherein the horizontal engagement pins (68) between the foil elements (2) and the vertical fitting pendants (58) are cast with concrete and / or mortar.