ANCHORING SYSTEM BETWEEN A CONCRETE COMPONENT AND A STEEL COMPONENT

Abstract

An anchoring system for forming a non-releasable connection between a concrete component, has a reinforcement containing at least one steel bar mesh, and a steel component. At least one anchoring element formed of an anchor strip is cast into the concrete component in such a way that at least one connecting surface projects at least partially from the concrete component. This improves the loadability of the anchoring. For this purpose, the anchor strip has a number of recesses which extend at least partially into the concrete component and which are each traversed by at least one steel bar of the steel bar mesh.

Description

BACKGROUND OF THE INVENTION

Field of the Invention

The invention relates to an anchoring system for forming a non releasable connection between a concrete component and a steel component. It also relates to a reinforced concrete-steel structure produced therewith.

The material concrete, and in particular the variant reinforced concrete, can be widely used as a building material. However, in many cases, the building material is not used exclusively, but in combination with other building materials. Here, it is usual for individual elements or entire assemblies to be produced from concrete or reinforced concrete and for supplementary elements or assemblies to be produced from another material, for instance steel. The individual elements or assemblies must be connected to one another during assembly. In this case, anchorages are frequently used.

The prior art discloses corresponding anchorages or anchoring systems in diverse variations. The configuration of such anchorages or anchoring systems substantially depends on which materials are to be combined with one another and to which loading an anchorage or an anchoring system will be exposed.

Austrian patent application AT 505 269 A1, corresponding to U.S. Pat. No. 7,617,990, discloses an anchoring system which has been configured especially for anchoring a concrete component on a steel support, that is to say a steel component. According to the application, a strip-shaped body made of steel serves as an anchoring element and has for that purpose at least one recess. The anchoring element projects with the recess into the concrete component, and it is welded to the steel support on that side of the anchoring element which is opposite the recess. However, the permissible maximum loading of such an anchorage is not sufficient for diverse applications.

SUMMARY OF THE INVENTION

The object on which the invention is based is therefore to develop an anchoring system which is further improved and moreover can be subjected to greater loading, in particular for connecting a concrete component to a steel component.

With the foregoing and other objects in view there is provided, in accordance with the invention a reinforced concrete-steel structure. The reinforced concrete-steel structure includes a concrete component, a reinforcement having at least one steel bar mesh with steel bars, a steel component connected non-releasable to the concrete component, and at least one anchor strip having a connecting surface for connecting to the steel component and defining a connection between the steel component and the concrete component. The anchor strip is cast into the concrete component such that the connecting surface of the anchor strip projects from the concrete component. The anchor strip has a number of recesses formed therein and extend at least partially into the concrete component and each is traversed by at least one of the steel bars of the steel bar mesh. Each of the recesses is an indentation open toward the steel component and separating the connecting surface of the anchor strip into subregions spatially separated from one another.

An anchoring system corresponding to the teaching of this invention serves for forming a nonreleasable connection between a concrete component and a steel component. For this purpose, at least one anchor element formed of an anchor strip is cast into the concrete component in such a way that it projects at least partially from the concrete component. The exposed segment acts as connecting surface to the steel component and is fixedly connected thereto. A number of recesses are provided on the anchor strip on the connecting surface side and extend into the concrete component. Incorporated into that concrete component is at least one steel bar mesh as a reinforcement, wherein each recess on the anchor strip is traversed by at least one steel bar of the mesh. In this way, forces which act on the steel component are transmitted via the anchor element to the reinforcement of the concrete component. The acting forces thus act less locally and can accordingly be better absorbed by the concrete component. Consequently, the anchoring capacity, in particular with respect to tensile loading, is significantly increased by comparison with other anchoring systems.

According to a preferred embodiment, each recess separates the connecting surface into at least two sub regions which are spatially separated from one another. Thus, during the manufacture of the anchor strip, each recess is incorporated into the anchor strip as a lateral indentation which is simple to produce. By connecting the anchor strip and the steel component within the scope of the production, each recess is then completed to form a type of eye through which at least one steel bar of the steel bar mesh engages. An eye thus formed acts, as it were, as favored linkage point or favored force transmission interface between the concrete component and the steel component.

In an expedient development, a plurality of regularly arranged recesses in the manner of a tooth row are provided. As a result, a very large number of favored linkage points and a uniform distribution thereof can be achieved. Forces acting on the steel component are then also transmitted in a correspondingly uniform manner to the reinforcement and thus to the concrete component.

Preference is further given to an embodiment of the anchor strips in which each recess has the contour of a quadrangle or of a symmetrical trapezium. These shapes promote, inter alia, a very simple and thus economically efficient production of the anchor strips.

Moreover, it is advantageous if the anchor strips used are profile strips having an L-shaped cross section, T-shaped cross section, or I-shaped cross section. On the one hand, such a cross section produces a barb-like effect, that is to say an improved retention of an anchor strip in the concrete, and, on the other hand, it is thus possible to have recourse to commercially available standard profile articles for the starting products for the production of the anchor strips. Moreover, I-profile strips, U-profile strips, double-T-profile strips and Z-profile strips as starting products are suitable for producing two anchor strips in one production process. By means of a cut, extending in the strip longitudinal direction, centrally through such a profile strip with a cut pattern corresponding to a tooth row with quadrangular or trapezoidal teeth, there will always result two identical anchor strips with mutually complementary cut patterns which are offset with respect to one another in the strip longitudinal direction.

Since an anchoring system according to the invention is configured above all for ensuring the highest possible loading limits, the anchor strips are preferably produced from steel, in particular from ferritic or austenitic steel. In this context, it is accordingly considered to be advantageous if each anchor strip is connected in an integrally bonded manner, in particular welded, to the corresponding steel component.

By virtue of its load ability, an anchoring system according to the invention is also suitable for the construction of a reactor safety container, a pressure container or a tank container. According to a typical manner of construction, these are constructed from reinforced and, if appropriate, prestressed concrete components which form the concrete shell. Provided on the inner side of the concrete shell is a steel shell, also referred to as a liner, consisting of a number of steel components, which steel shell ensures that the concrete shell is leak tight. Finally, the steel components are connected non-releasably to the concrete components with the aid of anchorages according to the invention.

Precisely for the safety requirements of a reactor safety container (containment), the design and the construction of the anchorage of the steel shell, also referred to as containment liner, of the reactor safety container is of major importance. With respect to the permissible stresses and rigidities, high requirements on the anchorage are defined in various standards and guidelines. The anchorage must withstand both the forces and loads occurring in normal operation and also in the event of a fault and at the same time prevent crack formation/crack propagation in the steel shell. As has now been recognized, these requirements can be met more efficiently if the steel shell, the anchorage and the reinforced concrete cooperate in the depth of the anchorage. In this regard, the anchoring system according to the invention offers a maximum degree of effectiveness.

In order to understand this more clearly, the hitherto customary anchoring systems will again be discussed briefly at this point:

The design and construction of previously used systems for anchoring the steel shell are generally based on the use of standard L-profiles, T-profiles or Z-profiles which are cast in unmodified form directly into the concrete and welded to the steel shell. These systems have the disadvantages now described.

The anchoring profiles are usually welded directly to the steel shell using continuous weld seams on both sides of the profile. Here, the welding usually takes place manually. Here, in the case of a reactor containment, the lengths of all the weld seams add up to several kilometers. Here, the manual welding work entails high costs.

The depth (profile height) of the anchoring profile is usually above 70 mm and thus above the minimum of the required thickness of the concrete covering (=30-40 mm). The reinforcing layer can be placed only behind (below) the anchoring profiles. As a result, the maximum bending capacity of the reinforced concrete cross section is reduced.

The continuous anchoring profiles represent a physical barrier for the flow of the concrete during the casting process between the individual profiles.

The anchoring profiles are embedded only in the applied layer of the concrete without an interface to the reinforcement. As a result, the loading capacity of the anchorage with respect to normal and transverse shear stress is reduced to that of the embedded concrete. Results from numerous tests show that a failure of the concrete occurs before the failure of the anchoring profiles.

The anchoring system proposed here, which can also be referred to as a “liner shaped anchorage system” provides a far better anchorage of the steel shell (liner) by the specially shaped anchoring profiles (anchor strips) which are provided with recesses for the reinforcement and which allow a cooperation between the anchoring profiles and the reinforced concrete in the manner of a true composite structure. It balances the anchoring system and increases the efficiency of the anchorage. It offers, in particular, the advantages that are now listed.

By using the anchoring system according to the invention it is possible to achieve a reduction of the required weld seam lengths by a factor of 3 or more as a result of the regularly interrupted and thus shortened connecting surfaces without relevant weakening of the anchor strip-liner connection. At the same time, a reduction in the previously required time for preassembling a prefabricated part of the steel shell and also a reduction in the costs for welding work are achieved. These savings considerably outweigh the outlay for cutting the starting profiles.

The anchoring system according to the invention allows parts of the reinforcement to be placed in the interspace between the continuous inner webs of the anchoring profiles and the steel shell connected thereto at the outer connecting surfaces while taking the minimum required concrete covering into consideration. Moreover, the system increases the bending strength of the concrete cross section.

The recesses in the correspondingly shaped anchoring profiles prevent the formation of a continuous physical barrier which impedes the flow of the concrete during the casting process.

The anchoring profiles used couple/integrate at least two layers of crossed reinforcement. This increases the anchoring capacity and makes it possible to achieve a balance between the capacity of the profiles and the reinforced concrete.

The integration of the anchoring profiles in conjunction with the reinforcement affords a higher stability of the steel shell while the concrete is being cast.

In summary, the anchoring system according to the invention with specially shaped anchoring profiles offers an efficient solution for embedding the profiles into the concrete together with an optimized interface to the reinforcement and with simultaneously a large savings potential with regard to the production costs and production times. Moreover, the use of this system increases the efficiency of the anchorage of the steel shell. It can be used both for reactor containers and other safety containers (containments) and gas and liquid containers and also for pressure containers.

The invention is described further by way of an exemplary embodiment.

Other features which are considered as characteristic for the invention are set forth in the appended claims.

Although the invention is illustrated and described herein as embodied in an anchoring system between a concrete component and a steel component, it is nevertheless not intended to be limited to the details shown, since various modifications and structural changes may be made therein without departing from the spirit of the invention and within the scope and range of equivalents of the claims.

The construction and method of operation of the invention, however, together with additional objects and advantages thereof will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING

FIG. 1 is a diagrammatic, longitudinal sectional view, represented as a detail, of a structure, namely of a reactor containment, having an anchoring system according to the invention;

FIG. 2 is a cross-sectional view of two commercially available profile strips; and

FIG. 3 is a side view of a U-profile strip with a cutting line indicated.

DETAILED DESCRIPTION OF THE INVENTION

Parts which correspond to one another are provided with the same reference signs in all of the figures.

Referring now to the figures of the drawing in detail and first, particularly, to FIG. 1 thereof, there is shown the functional principle of an anchoring system according to the invention. A longitudinal section, represented as a detail therein, shows a concrete component 1 which, with the aid of at least one anchor strip 2, is non-releasable connected to a steel component 3, also referred to as a liner plate, embodied in the manner of a flat steel plate. A plurality of anchor strips 2 of this type can be situated at a certain distance behind one another perpendicularly to the drawing plane, although this cannot be seen from the figure.

Provided as the anchor strip 2 in this exemplary embodiment is a half of a steel profile strip which can be produced by dividing into two a commercially available standard profile 4, 5 shown in FIG. 2 and FIG. 3. Here, the corresponding standard profile 4, 5 is severed along a cutting line 7 extending substantially in the strip longitudinal direction 6. The cutting line 7 is preferably selected such that, as a consequence, there is formed, along both halves, a type of tooth row having teeth separated from one another by recesses or interspaces. By way of example, the shape of a symmetrical trapezium was selected both for the teeth and for the teeth interspaces of the tooth row. As a result, it is possible to produce two usable anchor strips 2 with only one work step. Both anchor strips 2 can be considered as equivalent. They differ only through an offset of the tooth row in the strip longitudinal direction 6. To separate the standard profiles 4, 5, any suitable separating process can be used, such as, for example, cutting, shearing, punching and related processes such as, for instance, laser cutting.

Owing to the use of standard profiles 4, 5 in the production, each anchor strip 2 has a strip-like retaining foot 8 which is formed from the corresponding upper or lower flange of the standard profile and which preferably projects outwardly from the plane of the teeth and recesses, i.e. perpendicular to the drawing plane, which retaining foot, in the final mounting state of the anchoring system, also lies in the concrete component 1 and therefore acts, as it were, as a barb. To increase the stability and distortion rigidity of the anchor strip 2, the recesses in the transverse direction 11 are not led completely as far as the retaining foot 8, but there remains in each case a narrow web 13 connected to the retaining foot 8.

In addition to the retaining foot 8, most of the remaining anchor strip body in the final mounting state is also encapsulated by the concrete of the concrete component 1 by spraying or casting. Only the outer ends of the tooth row teeth, that is to say tooth prangs 9, project from the concrete component 1. In the anchoring system according to the invention, the exposed tooth prangs 9 serve as segments of a connecting surface. Within the scope of the production process, welding, soldering or adhesive bonding is used to form at the segments of the connecting surface in each case an integrally bonded connection between the anchor strip 2 and the steel component 3. For this purpose, weld seams are preferably applied on both sides, at the butting edges of the anchor strip 2 and the steel component 3. By virtue of the recesses between the teeth, the total length of the connecting surface 9 in the longitudinal direction 6 is only around ⅓ of the total length of the anchor strip 2.

A mesh consisting of steel bars 10 as a reinforcement is incorporated into the concrete component 1 of the exemplary embodiment. The mesh contains a plurality of layers which are stacked above one another in an alternating sequence ABAB in the transverse direction 11. In FIG. 1, exactly four layers are represented. A different, in particular larger, number of layers can likewise be advantageous, however. The steel bars 10 assigned to a layer A are arranged parallel to one another and parallel to the longitudinal direction 6 of the anchor strip 2 and perpendicular to the steel bars 10 of a layer B, which extend perpendicular to the drawing plane. As a result, the observer can see a checker board pattern in the transverse direction 11 when viewing the reinforcement from above, to the extent that this can be seen freely corresponding to an exploded view. The steel bars 10 are preferably connected to one another at the contact points of the steel bars 10 of two layers situated directly above one another. Here, the type of connection can vary depending on the application. Particularly expedient variants are adhesive bonding, welding or a wrapping with wire. The steel bars 10 of two layers AB situated directly above one another and, if appropriate, also further layers can also be interwoven in that, for example, the steel bars 10 extending perpendicular to the drawing plane are guided past, alternately above and below, the steel bars 10 directly adjacent to them and extending in the longitudinal direction 6.

Important to the anchoring system according to the invention is the incorporation of the anchoring element, in this case the anchor strip 2, into the steel bar mesh serving as reinforcement for the concrete component 1 in such a way that the action of forces on the steel component 3 is transmitted via the anchoring element to the reinforcement. Acting forces thus act less locally and can accordingly be better absorbed by the concrete component. By connecting the anchor strip 2 and the steel component 3 within the scope of the production, each tooth interspace of an anchor strip 2 is formed in the manner of an eye 12. In each case a steel bar 10 of the steel bar mesh traverses such an eye 12, with the result that transmission of force according to the objective is possible at this point. Preferably, the steel bars 10 traversing the tooth interspaces each bear against the inner web 13 of the anchor strip 2. Each tooth interspace can also be traversed by more than one steel bar 10, or as an exception, by none, if at least some interspaces of the anchor strip 2 are correspondingly traversed by the steel bars 10. If, for example, tensile forces in the transverse direction 11 act on the respective anchor strip 2, the latter is secured not only via its retaining foot 8 in the concrete but is additionally anchored by the upper two layers of the steel bar mesh.

In the exemplary embodiment according to FIG. 1, the steel bar mesh has four layers of crossed and, if appropriate, partially interwoven steel bars 10, wherein the steel bars 10 of the lowermost layer, as seen in the direction of insertion into the concrete component 1, are perpendicular to the drawing plane and are guided past below the retaining foot 8 of the anchor strip 2, parallel to the steel bars 10 traversing the tooth interspaces further above. Some of the steel bars 10 of the immediately higher layer which extend longitudinally with respect to the anchor strip 2 can in this case be arranged in such a way that they are supported from above on the retaining foot 8 and thus do not directly come into contact with the steel bars 10 of the lowermost layer which extend perpendicular thereto.

Claims

1. A reinforced concrete-steel structure, comprising: a concrete component;a reinforcement having at least one steel bar mesh with steel bars;a steel component connected non-releasable to said concrete component; andat least one anchor strip having a connecting surface for connecting to said steel component and defining a connection between said steel component and said concrete component, said anchor strip being cast into said concrete component such that said connecting surface of said anchor strip projecting from said concrete component, said anchor strip having a number of recesses formed therein and extending at least partially into said concrete component and each being traversed by at least one of said steel bars of said steel bar mesh, each of said recesses being an indentation open toward said steel component and separating said connecting surface of said anchor strip into subregions spatially separated from one another.

2. The reinforced concrete-steel structure according to claim 1, wherein a regular configuration of said recesses in a manner of a tooth row is provided in said anchor strip.

3. The reinforced concrete-steel structure according to claim 1, wherein said recesses each have a quadrangular contour.

4. The reinforced concrete-steel structure according to claim 1, wherein said recesses each have a contour of a symmetrical trapezium.

5. The reinforced concrete-steel structure according to claim 1, wherein said anchor strip is cut from a profile strip having an L-shaped cross section, a T-shaped cross section, a double-T-shaped cross section, an I-shaped cross section, a U-shaped cross section or a Z-shaped cross section.

6. The reinforced concrete-steel structure according to claim 1, wherein said anchor strip is formed from steel.

7. The reinforced concrete-steel structure according to claim 1, wherein said anchor strip is connected in an integrally bonded manner at said connecting surface to said steel component.

8. The reinforced concrete-steel structure according to claim 1, wherein said anchor strip is one of a plurality of anchor strips disposed next to one another.

9. The reinforced concrete-steel structure according to claim 1, wherein said steel component is a steel plate.

10. The reinforced concrete-steel structure according to claim 8, wherein said steel bar mesh has at least four layers of crossed said steel bars, wherein said steel bars of a lowermost layer of said steel bar mesh, as seen in a direction of insertion into said concrete component are guided past below said anchor strips.

11. The reinforced concrete-steel structure according to claim 1, wherein the reinforced concrete-steel structure is selected from the group consisting of a reactor safety container, a pressure container and a gas and liquid tank.

12. The reinforced concrete-steel structure according to claim 1, wherein said anchor strip is formed from ferritic steel or austenitic steel.

13. The reinforced concrete-steel structure according to claim 1, wherein said anchor strip is welded at said connecting surface to said steel component.

14. The reinforced concrete-steel structure according to claim 8, wherein said anchor strips are oriented parallel to one another.

15. The reinforced concrete-steel structure according to claim 8, wherein said steel bar mesh has at least four layers of crossed and partially interwoven said steel bars, wherein said steel bars of a lowermost layer of said steel bars, as seen in a direction of insertion into said concrete component are guided past below said anchor strips.