EP2661527B1 - Protective system for walls of buildings or containers - Google Patents

Description

The invention relates to a protection system against impact or impact loads for building or container walls, which is preferably also suitable for subsequent attachment to existing building or container walls.

In principle, in addition to the dead loads and the intended payloads, the anticipated temporarily occurring additional loads, such as snow loads, ice loads, wind loads as well as impact or impact loads, are taken into account in the planning of the building or in the container construction. In some cases, for example, due to changes in regulations or standards, beyond a subsequent revision of the building or the container. In these cases, it is ensured, for example, by attachments or conversions, that the structure or container can handle additional loads beyond the originally planned load limit.

In this context, the terms impact and impact loads all events are summarized in which an accelerated mass collides with a building or a container. In civil buildings or containers used these impact or impact loads are mainly caused by wind-accelerated items and improperly guided vehicles. On the other hand, if the building or the container is viewed by potential aggressors as a military target object, then impact or impact loads, which are caused, for example, by projectiles or guided missiles, are to be expected.

To protect buildings or containers from high-energy impact loads, mainly simple and massive steel plates or reinforced concrete slabs are currently used. The disadvantage here are the high weight and the large dimensions of the plates.

Furthermore, it is off WO 2009/048676 A1 a protection system for protecting a building or container wall against impact loads having the features of the preamble of claim 1. WO 2010/082970 A2 teaches, in a similar context, the use of so-called syntactic foams as filler material. According to expert understanding, these are composite materials in which microspheres made of glass or ceramic are embedded in a matrix of synthetic resin.

Proceeding from this, the present invention seeks to develop a weight and / or dimensionally reduced system or construct, can be protected with the buildings and transport containers in particular against high-energy impact or impact loads.

This object is achieved by the feature combination of claim 1 in an inventive manner. The subclaims contain in part expedient and in part self-inventive developments of this invention.

A protective system according to the teachings of this invention acts to protect a single building wall, a complete building, a single container wall or a complete container against impact or impact loads. For this purpose, it is provided to arrange a buffer layer on the impact or impact side of the area to be protected, which absorbs the kinetic energy caused by impact or impact predominantly by plastic deformation. The skeleton or skeleton of this buffer layer form similar, composed of lattice struts unit cells, which are arranged substantially regularly and thus completely cover the area to be protected as deformation lattice. Thus, the skeleton of the buffer layer, which is formed from at least one layer of these unit cells, has a crystal-like basic structure. The shape of a single unit cell is pyramidal, with the grid struts forming the edges of the pyramidal shape. The basic framework is supplemented by a deformable deformation mass, which fills the gaps in the deformation grid and thereby completes the buffer layer.

Preference is given to an embodiment in which the lattice struts of a unit cell form a regular pyramid, since both a favorable deformability is achieved by this design of the skeleton and a simple technical feasibility is ensured. In this context, it is also useful if the base of the pyramidal shape is quadrangular and in particular square.

Furthermore, it is considered advantageous if the deformation grid has at least two, but preferably four to eight, grid layers of unit cells, since with increasing number of grid layers, the maximum absorbable impact or impact energy increases. On the other hand, of course, the thickness and the weight of the protection system increase with increasing number of layers. With eight grid layers, simulation calculations show that even large and heavy projectiles with high airspeeds are safely stopped within the buffer layer and do not penetrate to the underlying building or container wall.

If a plurality of grid layers are provided, it is also advantageous if in each case two grid layers lying directly one above the other are arranged laterally offset from one another by half the length of the diagonal of an elementary cell base surface in the direction of the diagonal. In short, therefore, the grid layers lying directly above one another are displaced diagonally by half an elementary cell. This results in an alternating stacking sequence ABAB, in which the tips of the pyramid forming the lower grid position lie against the corners of the base areas of the pyramids forming the overlying grid layer. As a result formed X-shaped struts serve as additional stiffening elements in the deformation grid.

The material used for the lattice struts is preferably high-ductility steel. This is available in a wide variety of specifications, so that a good variability is given by which an adaptation of the properties of a buffer layer according to the invention to different specifications or standards is made possible.

In principle, it is conceivable to connect the lattice struts to one another only with the aid of the deformation mass and to hold them in their relative positions with respect to one another. Prefers However, an embodiment in which the lattice struts of a unit cell and the unit cells and grid layers are each firmly connected to each other, so for example screwed, glued or welded, so that the skeleton itself already represents a construction that up or Can absorb impact energy through plastic deformation.

If, for example, the buffer layer also acts as a protection against impacting missiles, then it is expedient for a unit cell to have a lateral extent of approximately 0.5 m to 4.0 m and thus not necessarily identical height extent of 0.5 m to 4 m, 0 m provide. For the lattice struts appropriately cut square or round steel with an edge length or a diameter of about 10 mm to 50 mm is used in this case.

According to the invention, so-called foam concrete or porous lightweight concrete (PLB) is used as the damping mass. Foamed concrete is a concrete with a planned increase in the air pore content of generally> 30% by volume, which is usually produced by adding a foaming agent or by mixing in a prefabricated foam. On the one hand, this material can absorb large pressure forces and on the other hand it is comparatively light (low density) and readily flowable. He also has good thermal insulation properties. According to the invention, the foam concrete used in addition fibers, for example of steel or plastic, admixed to increase its ductility and thus, with respect to the buffer layer, its effectiveness. Details about this type of material can be found in the literature under the heading "UHPC" (Ultra High Performance Concrete).

Moreover, it is advantageous if the buffer layer terminates on the impact or impact side with a cover layer, for example made of steel or a composite material, in particular a fiber composite material. This is used in particular in the case of a sharp or sharp-edged impact or impact body for better distribution of selective pressure surges on a larger area of the deformation grid and thus to increase the effective attack surface. During the construction of the protection system The cover layer can also serve as a shuttering when casting the damping mass.

In this context, an attachment of the cover layer to the buffer layer by means of anchor elements is considered to be very useful, as this can be done, for example, a simple exchange. Alternatively, it is also conceivable to bond the cover layer with the buffer layer over a large area.

An inventive protection system is designed primarily as a protection for flat surfaces. Accordingly, it is advantageous to choose an arrangement of the unit cells in which the bases of the unit cells of each grating layer lie in a common plane and in which these planes are aligned parallel to the surface of the building or container wall to be protected. Nevertheless, an adaptation of the buffer layer to curved surfaces (such as domes, domes, cylinders and the like) can also be done. For this purpose, either the deformation lattice is distorted according to the curvature or a modified deformation lattice with a modified lattice structure is used.

The advantages achieved by the invention are in particular that by a "composite" structure of a three-dimensional, lightweight, highly deformable (ductile) and preferably multi-layered space frame structure and a cast damping mass a particularly good conversion of the kinetic energy of impact loads (z Aircraft, turbulence-induced projectiles, pressure waves) takes place in plastic deformations of the structure, wherein the damping mass acts as a stabilization matrix with a very high degree of damping. Due to the non-linear deformation and crushing of the fiber-reinforced foam concrete (fiber foam concrete) produced damping mass is additionally absorbed impact energy. In contrast to conventional solutions in which impact protection is achieved by increased rigidity (greater wall thickness) and increased reinforcement content (eg shear reinforcement, rebar connections) of the affected reinforced concrete components, in the impact protection system according to the invention, the formation and propagation of vibrations, vibrations and elastic waves significantly suppressed or damped and kept away from the object or structure to be protected.

This ensures additional protection against seismic loads. Seismic stimuli or shocks are also effectively damped.

The protection system according to the invention can be easily and quickly erected, in particular when using preassembled units of the deformation grid, which are installed in layers on the object to be protected and subsequently cast with the damping compound. A retrofitting of existing wall structures is possible.

Particularly advantageous is the use of the protection system according to the invention in buildings of nuclear facilities, especially nuclear power plants, but also in conventional power plants and chemical plants, as well as transport containers for nuclear or chemical materials and waste.

Fig. 1

in einer perspektivischen Ansicht eine Elementarzelle einer erfindungsgemäßen Pufferschicht,

Fig. 2

in einer perspektivischen Ansicht eine Gitterlage eines Deformationsgitters einer erfindungsgemäßen Pufferschicht,

Fig. 3

in einer perspektivischen, zum Teil geschnittenen Ansicht eine erfindungsgemäße Pufferschicht auf einem ausschnittsweise dargestellten Gebäudedach, oder

Fig. 4

einen Profilausschnitt eines Deformationsgitters.

Reference to an embodiment of the invention will be further described. It shows in a simplified and schematic representation:

Fig. 1

in a perspective view of an elementary cell of a buffer layer according to the invention,

Fig. 2

in a perspective view, a grid position of a deformation grid of a buffer layer according to the invention,

Fig. 3

in a perspective, partially sectioned view of a buffer layer according to the invention on a partial roof of the building, or

Fig. 4

a profile section of a deformation grid.

Corresponding parts are provided in all figures with the same reference numerals.

In the exemplary embodiment, a partial section of a building roof 1 is considered by way of example (see Fig. 3 ). The flat outer surface 2 of this section is to be protected by a subsequent cultivation against impact or impact loads. For this purpose, a buffer layer 3 is positioned on the surface 2. The fixation of the buffer layer 3 on the surface 2 takes place with the aid of a material connection not shown in detail or in any other way.

As a basis for the buffer layer 3 is a construction of welded together lattice struts 4. It should be noted again at this point that the nature of the permanent connection between the lattice struts 4 is not limited to those selected here. As also expedient alternatives connections are considered by screwing, riveting, jamming or gluing. Eight of these lattice struts 4 made of cut round steel form a Fig. 1 represented unit cell 5. According to their spatial arrangement form the lattice struts 4 of an elementary cell 5, the edges of a straight pyramid square base. The ratio between the edge length of the square base and the height of the pyramid is about 1.7 in this case.

By a regular arrangement of unit cells 5 and the non-detachable connection of these unit cells 5 with each other, a crystal-like deformation grid is formed. This is, as it were, constructed from a multiplicity of grid layers 6, which are stacked one above the other in the stacking direction 7. The arrangement of the unit cells 5 within each grid layer 6 is designed such that the square base surfaces of the unit cells 5, as in a chessboard, each other without gaps, whereby the bottom in the stacking direction 7 grid layer 6 completely covers the protected surface 2 to be protected. A schematic representation of the arrangement of a grid layer 6 is shown in FIG Fig. 2 to see.

Two directly superimposed grid layers 6 are arranged laterally offset from one another by half the length of the diagonal of an elementary cell base surface in the direction of the diagonal. Because of this alternating stacking sequence ABAB, the tips of the pyramids forming the lower grid layer 6 and the corners of the base areas of the pyramids forming the overlying grid layer 6 touch each other.

Exactly at these points of contact, the individual grid layers 6 are permanently connected to each other, so welded. At the same time additional X-shaped braces 8 are realized in this way. They serve, as with a crane boom or a steel bridge construction, as additional stiffening elements in the deformation grid. Visible are the X-shaped struts 8 when looking at the deformation grating in the profile. A corresponding section shows Fig. 4 ,

The deformation grid acts in a buffer layer 3 according to the invention in the manner of a skeleton or skeleton. This framework is surrounded by a damping mass 9 made of fiber-reinforced foam concrete. That foam concrete complements the deformation grid to a cuboid buffer layer 3 and fills in the gaps in the deformation grid.

Both components, the damping mass 9 and the deformation grid, can in themselves absorb impact or impact energy. While in the deformation lattice this is done mainly by plastic deformation, the energy absorption in the damping mass 9 is effected primarily by a compression. By combining both components into a buffer layer 3, however, the absorption capacity, as well as the damping capacity with respect to pressure waves or vibrations, of the individual components is exceeded.

LIST OF REFERENCE NUMBERS

1

building roof

2

Outer surface

3

buffer layer

4

lattice strut

5

unit cell

6

grid Location

7

stacking direction

8th

brace

9

damping mass

Claims (13)

1. A protective system for protecting a wall of a building or container from impact loads, having a buffer layer (3) which is arranged on the impact side of the wall of the building or container and absorbs the impact energy of the impact load predominantly by plastic deformation, wherein the buffer layer (3) comprises a deformation lattice which is formed by a substantially regular arrangement of unit cells (5) and has a number of lattice layers (6) whose intermediate spaces are filled with a deformable damping mass (9), and wherein each unit cell (5) is composed of a plurality of lattice struts (4) which form the edges of a pyramid,
   characterized in that fiber-reinforced porous concrete is used as a damping mass (9).
2. The protective system of claim 1, wherein the pyramid formed of the lattice struts (4) of a unit cell (5) is a regular pyramid.
3. The protective system of claim 2, wherein the pyramid formed of the lattice struts (4) of a unit cell (5) has a tetragonal, in particular square, base.
4. The protective system of any of claims 1 to 3, wherein at least two, preferably four to eight, lattice layers (6) are provided for the deformation lattice.
5. The protective system of any of claims 1 to 4, wherein each two lattice layers (6) lying immediately on top of each other are arranged with a lateral offset of half the length of the diagonal of the base of a unit cell (5), in the direction of the diagonal.
6. The protective system of any of claims 1 to 5, wherein the lattice struts (4) are made of steel.
7. The protective system of any of claims 1 to 6, wherein the lattice struts (4) are firmly connected with each other, in particular welded, in their contact points.
8. The protective system of any of claims 1 to 7, wherein a unit cell (5) has a lateral extension of approx. 0.5 m to 4.0 m and a height of approx. 0.5 m to 4.0 m.
9. The protective system of any of claims 1 to 8, wherein the buffer layer (3) is provided with a covering layer on the impact side.
10. The protective system of claim 9, wherein the covering layer is made of steel or a composite material.
11. The protective system of claim 9 or 10, wherein the covering layer is fastened to the buffer layer (3) by means of anchoring elements.
12. The protective system of any of claims 1 to 10, wherein the bases of the unit cells (5) of each lattice layer (6) lie in a common plane and wherein this plane is arranged in parallel to the surface of the building or container wall.
13. A building, container or industrial plant having a wall which is provided, at least in certain regions in an expected impact region, with a protective system of any of claims 1 to 12.

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