EP2711484A2 - Component with a flat reinforcing element - Google Patents

Abstract

The component has a base body (1) and a reinforcement element (2) i.e. prefabricated component, which is partially formed in a slot (3) in a surface (4) of the base body. The base body is partially connected with the reinforcement element using a fixing agent (5). The reinforcement element is divided into two end elements (6, 7) and a wedge shaped spacer (8) arranged between the end elements, where the spacer is made of metal or plastic material. The reinforcement element comprises unidirectional split up carbon fiber slat or carbon fiber reinforced plastic material. The fixing agent is selected from a group consisting of epoxy resin, epoxy resin sticking mortar, and cement base adhesive such as cement-bonded fine mortar.

Description

The invention relates to a component, in particular concrete component, with a base body and at least one at least partially planar reinforcing element, wherein the reinforcing element is at least partially disposed in a slot in a surface of the base body and there at least partially connected using a fixing means to the base body.

A component of the type mentioned is from the EP 0 996 797 B1 known. In the known component, a planar reinforcement element is introduced into a slot in a surface of a main body of the component. For fixing the reinforcing element in the slot, the reinforcing element is glued with an epoxy resin adhesive in the slot. Here, the adhesive is first introduced into the slot and then pressed the reinforcing element in the slot or in the epoxy resin.

This can be a gain of example. Concrete, reinforced concrete and prestressed concrete components. For bonding, epoxy resin-bonded adhesives are used for this purpose. This construction method is subject to approval in Germany. The power transmission from the component in the reinforcing elements is usually via a continuous bond between the reinforcing element and component by an epoxy resin adhesive.

From the EP 1 153 180 B1 It is known to strengthen a reinforced concrete beam by gluing with end elements and inserting a lamella in slots introduced into the end elements. In each case, three retaining slots are formed in the end elements, which receive a split in three end elements of the end of the reinforcing element. In other words, an end element of the lamella is arranged in each retaining slot.

Component reinforcements by bonding, for example, reinforcing elements formed as carbon fiber lamellae in slots of the components are usually carried out with epoxy resins or epoxy resin adhesive mortars, which are referred to as epoxy resin adhesive for short.

Epoxy resin adhesives are characterized in that they are very temperature sensitive in use. For this reason, the use of epoxy adhesives only approved up to an application temperature of 40 ° C to 45 ° C. With increasing temperatures, there is a reduction in the absorbable tensile forces of the epoxy resin adhesive, so that the carrying capacity of the thus reinforced component is limited.

Furthermore, exceeding the permissible application temperatures leads to increased creep deformation of the epoxy resin adhesive, so that power transmission into the carbon fiber fins used as reinforcing elements is not possible or only possible in a reduced manner.

The epoxy resin adhesives are also characterized in that they are sensitive to moisture and can therefore only be used on dry substrates. Usually, an underground moisture of less than or equal to 4% by mass is required.

Component reinforcements with carbon fiber fins bonded in slots are characterized in that they must not be exposed to water stress in the glued state, since the epoxy resin adhesives can react moisture-sensitive.

Commercially available epoxy resin adhesives approved for bonded component reinforcements are characterized by having a low modulus of elasticity of less than 10,000 N / mm ² . This results in bending stressed slim components to significant deflections, even if a higher component load is possible.

In the known reinforced components is therefore problematic that the transferability of tensile forces depending on the ambient conditions in terms of temperature and humidity is often insufficient. Nowadays desired amplification powers can often not be achieved with conventional amplification techniques.

The present invention is therefore based on the object, such a design and further develop a component of the type mentioned that a secure Reinforcement of components is made possible even at high temperatures and in a humid environment in a simple manner.

The above object is achieved by a component having the features of claim 1. Thereafter, the component is configured and further developed in such a way that the reinforcing element is split at least at one end into at least two end elements and a spacer is arranged between at least two end elements.

In accordance with the invention it has been recognized that the above object is achieved in a surprisingly simple manner by a slight modification of a conventional planar reinforcement element. For this purpose, the reinforcing element is in concrete on at least one end split into at least two end elements. As a result of this splitting of the reinforcement element, a surface which is larger in relation to the un-split reinforcing element is provided for interaction with the fixing means. Thus, the split state of the reinforcing element is retained securely, without the splitting is canceled due to a possibly existing elasticity of the reinforcing element, a spacer is arranged in a further inventive manner between at least two end elements. The arrangement of the spacer between the end elements of the split and spread state of the reinforcing element is securely maintained, so that a safe and easy installation and secure positioning can be achieved in the slot. As a result, a significant improvement in the transferability of tensile forces is achieved in comparison with conventional reinforcing elements. As a result, negative influences due to excessively high temperature or too high humidity can often be compensated or at least reduced, so that an extended field of application with regard to given environmental conditions is achieved with the component according to the invention.

Consequently, with the component according to the invention a component is specified with which a secure reinforcement of components is made possible even at high temperatures and in a humid environment in a simple manner.

With regard to a particularly secure reinforcement, the reinforcing element could be strip-shaped, preferably in the form of a lamella, with a longitudinally split end. With regard to the splitting, it is desirable that the largest possible increase in the surface area of the reinforcement element is achieved. For example. For example, a reinforcing element with a substantially rectangular cross-section could be split in such a way that two end elements are created which have the same width as the unresolved reinforcing element and approximately half the thickness. In that regard, the end elements would also have a substantially rectangular cross section and would be only thinner than the unaufgespaltene reinforcement element.

In practice, it has been found that, in particular, carbon fiber fins are particularly suitable as a reinforcing element, which are preferably designed unidirectionally with respect to their fiber direction. Consequently, a unidirectional split carbon fiber blade could be realized. In principle, reinforcing elements have proven to be very suitable, having the carbon fiber reinforced plastic.

In a structurally particularly simple manner, the spacer could have metal or plastic. Depending on the application, the spacer could be made entirely of metal or plastic.

With regard to a particularly safe and positionally stable arrangement of the spacer between the end elements, the spacer could be formed substantially wedge-shaped. Here, the wedge angle could be adapted to the angle at which the end elements are split. In this way, a particularly secure fit of the spacer between the end elements could be achieved.

The splitting of the reinforcing element according to the invention shows its effectiveness independently of the choice of fixing agent. For example, an epoxy resin, an epoxy adhesive mortar or a cement-based adhesive, preferably a cement-bonded fine mortar, could be used as the fixing agent. A secure end anchorage is achievable with conventional epoxy adhesives, and particularly with cementitious adhesives that exhibit somewhat less adhesive force.

Advantageously, the end elements could be spread at an angle of about 5 ° to about 60 ° to each other. When choosing this angle, it is necessary to focus on the respective application.

The end elements could be in a further advantageous manner each about 30mm to 1500mm long. In other words, the length of the spread could be between about 30mm and about 1500mm, depending on which forces need to be transmitted. The higher the forces to be transmitted, the longer the spread should be.

With regard to a particularly secure end anchoring, the split end could preferably be arranged completely in the slot. Due to the complete arrangement in the slot, the outer appearance of the component remains without an possibly projecting from the component end of the reinforcing element - almost unchanged as in an unreinforced state.

With regard to a particularly simple application of the reinforcing element in the working practice, the reinforcing element could be a prefabricated component. In concrete terms, a prefabricated carbon fiber lamella could be realized. As a result, the step of splitting a reinforcing element can be saved when used on a construction site.

With the component according to the invention, a significant improvement in the transferability of tensile forces is made possible. A special end anchoring of factory prefabricated carbon fiber blades is made possible with the invention.

A tensile force is introduced into the reinforcement element by force transmission via the fixing agent, which may be a conventional adhesive of epoxy resin or a cement-based adhesive.

In the case of the end anchoring of a reinforcing element according to the invention, for example a carbon fiber lamella, a high pressure force is transmitted to the adhesive between the spread or in the area between the end elements. For this reason, a compressive strength of the adhesive of at least 30 N / mm ^{2 is} useful. In the same way, a modulus of elasticity of at least 5,000 N / mm ^{2 is} favorable in order to prevent creep deformations by pulling out the reinforcing element ends.

With the component according to the invention and the thereby achievable type of Endverankerung a force transmission in adhesives, such as, for example, a cement-based adhesive not as high adhesive strength as, for example. Epoxy resin adhesive, possible because the reinforcing elements mechanically anchored on their end elements in the end become. This mechanical end anchoring can be produced very inexpensively.

Nowadays usual anchoring lengths in, for example, bonded reinforcing elements such as, for example, carbon fiber lamellae can be significantly reduced with the anchorage according to the invention. Furthermore, it is also possible to anchor thicker reinforcing elements or lamellas than the previously approved maximum 3mm thick reinforcing elements or carbon fiber lamellae in components.

Fig. 1

in einer Draufsicht, schematisch, ein Ausführungsbeispiel eines erfindungsgemäßen Bauteils und

Fig. 2

in einer perspektivischen Darstellung, schematisch, ein herkömmliches Bauteil.

There are now various possibilities for designing and developing the teaching of the present invention in an advantageous manner. For this purpose, on the one hand to the subordinate claims, on the other hand, to refer to the following explanation of an embodiment of the teaching of the invention with reference to the drawings. In connection with the explanation of the preferred embodiment of the teaching according to the invention with reference to the drawing, generally preferred embodiments and developments of the teaching are explained. In the drawing show

Fig. 1

in a plan view, schematically, an embodiment of a component according to the invention and

Fig. 2

in a perspective view, schematically, a conventional component.

Fig. 1 shows a schematic plan view of a component in the form of a concrete component with a base body 1 and with a sheet-like reinforcing element 2, wherein the reinforcing element 2 is arranged in a slot 3 in a surface 4 of the base body 1 and is connected there to the base body 1 using a fixing means 5. It shows Fig. 1 for clarity, not the entire component, but only a part of it.

In view of a secure reinforcement of the component even at high temperatures and in a humid environment, the reinforcing element 2 is split at one end into two end elements 6 and 7. It could also be a split into more than two end elements 6 and 7 are provided. Between the two end members 6 and 7, a spacer 8 is arranged to maintain the spread position of the end members 6 and 7 safe. The reinforcing element 2 shown here is formed by a carbon fiber blade.

The spacer 8 is formed substantially wedge-shaped in order to ensure a secure fit between the split end elements 6 and 7. Furthermore, the spacer 8 extends along the entire width of the reinforcement element 2 or the end elements 6 and 7.

The fixing agent 5 is formed by a high-strength to ultrahigh-strength adhesive. Between the spreading of the end elements 6 and 7 there is a high pressure force transmission to this adhesive.

Depending on the spread angle between the end elements 6 and 7, an end portion 9 of the slot 3 is widened in a corresponding manner. The slot 3 is thus wider in this end region 9 than in the remaining region of the slot 3, where the reinforcing element 2 is not yet split.

To produce the split reinforcement element 2, for example, a commercial carbon fiber blade can be split at the end in the longitudinal direction with a sharp knife or chisel. Subsequently, the spacer 8 is inserted for fixing the length and the angle of the spreading between the end elements 6 and 7.

The reinforcing element 2 can be dimensioned such that it is completely received or arranged in the slot 3 and does not protrude out of the slot 3.

Fig. 2 shows a perspective and schematic representation of a conventional component in which the reinforcing element 2 is also arranged in a formed in a surface 4 of a base 1 slot 3. The reinforcing element 2 is likewise fastened in the slot by means of a fixing means 5. However, the conventional reinforcing element 2 has no split end elements.

As with the in Fig. 1 embodiment shown is also in the in Fig. 2 shown conventional component, the reinforcing element 2 is formed flat in the form of a lamella and arranged in the slot 3, that the narrow side of the substantially rectangular cross section of the reinforcing element 2 extends parallel to the surface 4 of the base body 1.

With regard to further advantageous embodiments of the teaching of the invention reference is made to avoid repetition to the general part of the specification and to the appended claims.

Finally, it should be expressly understood that the embodiment described above is only for the purpose of discussion of the claimed teaching, but this does not limit this embodiment.

LIST OF REFERENCE NUMBERS

1

body

2

reinforcing element

3

slot

4

surface

5

fixer

6

end element

7

end element

8th

spacer

9

end

Claims (10)

Component, in particular concrete component, with a base body (1) and at least one at least partially planar reinforcing element (2), wherein the reinforcing element (2) at least partially in a slot (3) in a surface (4) of the base body (1) and arranged there at least in sections, using a fixing means (5) is connected to the base body (1),
characterized in that the reinforcing element (2) is split at least at one end into at least two end elements (6, 7) and a spacer (8) is arranged between at least two end elements (6, 7). Component according to claim 1, characterized in that the reinforcing element (2) is strip-shaped, preferably in the form of a lamella, with a longitudinally split-open end. Component according to claim 1 or 2, characterized in that the reinforcing element (2) is a preferably unidirectional split carbon fiber blade or carbon fiber reinforced plastic. Component according to one of claims 1 to 3, characterized in that the spacer (8) comprises metal or plastic Component according to one of claims 1 to 4, characterized in that the spacer (8) is substantially wedge-shaped. Component according to one of claims 1 to 5, characterized in that the fixing means (5) is an epoxy resin, a Epoxidharzklebört or a cement-based adhesive, preferably a cement-bonded fine mortar. Component according to one of claims 1 to 6, characterized in that the end elements (6, 7) are spread apart at an angle of about 5 ° to about 60 ° to each other. Component according to one of claims 1 to 7, characterized in that the end elements (6, 7) are each about 30mm to 1500mm long. Component according to one of claims 1 to 8, characterized in that the split end is arranged completely in the slot (3). Component according to one of claims 1 to 9, characterized in that the reinforcing element (2) is a prefabricated component.

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