DE102013208694A1 - Prestressed concrete element comprising a reinforcement with integrated equipotential bonding - Google Patents

Abstract

The subject of the invention is a prestressed concrete element (SE) with integrated equipotential bonding having a reinforcement (S) which is surrounded with concrete, the prestressed concrete element (SE) essentially having a panel-like configuration, the panel-like configuration having two side surfaces that are essentially parallel to one another (F1, F2, F3, F4), the reinforcement (S) having one or more electrically conductive tensioning elements in the longitudinal direction of the prestressed concrete element (SE), and the prestressed concrete element (SE) furthermore at least one electrical connection (A) to an electrically conductive one Tensioning element of the reinforcement (S) which can be contacted on at least one of the side surfaces (F1, F2, F3, F4) of the prestressed concrete element (SE) and its manufacturing method.

Description

The invention relates to prestressed concrete elements having a reinforcement with integrated equipotential bonding.

Prestressed concrete elements have been used in the manufacture of ceilings in buildings since the 1930s. A significant advantage of tensioned concrete elements is the high load-bearing capacity and economical material consumption. Another advantage is the low weight.

Nowadays, some currently valid constraints in standards, such as the DIN 1045-1: 2001-07 or the DIN 1053-1: 1996-11 described.

Prestressed concrete ceilings or ceilings made of prestressed concrete elements require no supporting installation aids, such as mounting columns or yokes, during installation - in contrast to so-called in-situ concrete ceilings. Also in the further progress of the course of construction - in contrast to so-called in-situ concrete ceilings - no elaborate reinforcement and concreting work. Only the joints between individual prestressed concrete elements are usually reinforced and filled with concrete. Therefore, the installation is quick and inexpensive to implement.

When setting up, it may be necessary to insert ring beams or ring anchors, stirrups and joint reinforcements according to static calculations.

Demands on equipotential bonding systems or on shielding systems against electro-magnetic radiation are increasingly being placed both in private house construction and in industrial construction.

In order to meet these requirements reasonably, it was only possible with known prestressed concrete elements due to inadequate contacting possibilities of individual prestressed concrete elements to use the reinforcement of the ring beams or ring anchors and to connect them, for example, with an additionally introduced potential equalization ring conductor on site to achieve one of the above effects.

However, if higher demands are placed on the quality of a potential equalization system, this has been possible with existing ceilings only by deviating to other ceiling structures, e.g. a filigree ceiling or in-situ concrete ceiling. In the case of these ceiling superstructures, a mesh-type reinforcement created by the customer can be integrated into the equipotential bonding system in a suitable form.

Since such a mesh-like reinforcement is not present in prestressed concrete elements, there remains only the possibility to introduce in the joints between the prestressed concrete elements in addition to the required static reinforcement and additional equipotential bonding.

However, this solution proves to be relatively expensive. Also, overall, as a rule, a higher cost of materials can be expected. In addition, the introduction is time-consuming and thus leads to increased costs.

The invention is based on the object to provide prestressed concrete elements that avoid one or more disadvantages of the prior art.

The object is achieved by the features of the independent claims. Advantageous embodiments of the invention are specified in the subclaims.

The invention will be explained in more detail with reference to the accompanying drawings with reference to preferred embodiments.

Show it

1 a prestressed concrete element according to preferred embodiments of the invention in a perspective view,

2 1 is a schematic view of a concrete strand with prestressed concrete elements according to preferred embodiments of the invention in relation to one aspect;

3 a schematic view of a concrete strand with prestressed concrete elements according to preferred embodiments of the invention in relation to another aspect,

4 a schematic view of a concrete strand with prestressed concrete elements according to preferred embodiments of the invention in relation to yet another aspect,

5 1 is a schematic view of a concrete strand with prestressed concrete elements according to preferred embodiments of the invention in relation to a further aspect;

6 a schematic view of a prestressed concrete element according to preferred Embodiments of the invention in a view of one of the side surfaces,

7 a schematic view of a prestressed concrete element according to preferred embodiments of the invention in a view of another of the side surfaces, and

8th a schematic view of prestressed concrete elements according to preferred embodiments of the invention in a plan to explain the equipotential bonding.

The 1 to 7 show one or more prestressed concrete elements SE. These have an integrated equipotential bonding according to the invention.

The provision of equipotential bonding will be explained below.

First, the prestressed concrete element SE has a reinforcement S. This reinforcement S may be formed in a conventional manner by electrically conductive tensioning elements, e.g. by steel wires or steel strands or other suitable metallic alloys.

In the finished prestressed concrete element SE, the reinforcement S is surrounded by concrete.

The prestressed concrete element SE, as in 1 has substantially a panel-like configuration, wherein the panel-like configuration each has two substantially parallel to each other aligned side surfaces F ₁ , F ₂ , F ₃ , F ₄ . In 1 only the side surfaces F ₁ , F ₂ can be seen. The side surfaces F ₃ , F ₄ are designed generally similar.

The reinforcement S points - as in the 1 to 5 better seen - one or more electrically conductive clamping elements S, eg steel cables or steel strands, in the longitudinal direction of the prestressed concrete element SE. In 1 These electrically conductive clamping elements are shown as a dashed line, while in the 2 to 5 the electrically conductive clamping elements S are shown as a solid line.

An example of electrically conductive clamping elements S are steel cables or steel strands. For the prestressed concrete element in general, only the provision of strength is essential here, while the aspect of the electrical conductivity of the reinforcement S is more important for the invention. That Without limiting the generality, any other material or combination of materials is alternatively usable, which provide a prestressed concrete element SE similar mechanical properties and a corresponding electrical conductivity.

The prestressed concrete element SE now also has at least one electrical connection A to an electrically conductive clamping element of the reinforcement S, as in 4 and 5 exemplified. The electrical connection A may for example be made of a stainless steel, at least of stainless steel. The length of such a lead-out connecting element A may vary depending on the embodiment and requirement and may also be half a meter, so that a mechanic sufficient movement space remains. These connection elements A can preferably be designed as a round conductor with a diameter of 10 mm.

This electrical connection A can be contacted on at least one of the side surfaces F ₁ , F ₂ , F ₃ , F _{4 of} the prestressed concrete element SE. This is exemplified in 4 and 5 shown where the electrical connection A is guided laterally from the prestressed concrete element SE. In 1 this is shown in perspective on the side surface F _{2 by way of} example.

That is, the electrically conductive clamping elements present in the prestressed concrete elements SE, e.g. Steel strands or wires are now at least partially exploited for potential equalization purposes.

As in the 2 and 3 In addition, if the reinforcement S has a large number of electrically conductive clamping elements, then at least two of the electrically conductive clamping elements can optionally be in electrical connection Q with one another. It is in the 2 and 3 an exemplary concrete strand BS shown, from which the individual prestressed concrete elements SE are worked out in the manufacturing process. It is in the 2 and 3 it is assumed that the exemplary prestressed concrete elements SE can have different lengths L ₁ , L ₂ , L ₃ . In each of the prestressed concrete elements, as a further aspect of the invention, there is at least one electrical connection Q, which contacts a plurality of the electrically conductive clamping elements of the reinforcement S in the transverse direction. As a result, an improved meshing and thus an improved shielding or an improved potential equalization can be provided.

In addition, it can be provided that a plurality of such electrical cross-connection elements Q per prestressed concrete element SE is provided. This is easily possible, as long as the distance d _q between two adjacent electrical cross-connecting elements Q is smaller than the length L of the relevant prestressed concrete element SE, as shown for example in the prestressed concrete element in the middle with the length L ₂ .

It can - as in the 2 and 3 shown - be provided that the electrically conductive clamping elements either as in 2 shown all are connected with each other transversely, or that as in 3 shown, different electrically conductive clamping elements of the reinforcement S are interconnected. Without further ado, as in 3 indicated, the type of electrical cross-connection elements for each prestressed concrete element SE also be designed individually, so that the respective requirements for the prestressed concrete element SE is done. In this case, for example, a parameter that influences the selection and number of electrical cross-connection elements Q, the length L of the prestressed concrete element SE be.

In particular, if the reinforcement S has a multiplicity of electrically conductive clamping elements, then at least two of the electrically conductive clamping elements can be in electrical connection with one another at at least two different locations Q within the prestressed concrete element SE.

As in 4 - in contrast to 5 - Shown, the electrical connection A to an electrically conductive clamping element of the reinforcement S at the same time bring at least two of the electrically conductive clamping elements with each other in electrical connection Q. That is, the electrical cross-connection element Q and the connection element A can be introduced as a unitary component, whereby the material and time required decreases.

Alternatively, however, can also - as in 5 shown on the right side - the connection element A can also be designed as a separate element, for example, to achieve a placement at a certain point of the prestressed concrete element, for example, so that the connection element A in about the same distance to the front side disposed side surface F ₁ , F _3rd having. As a result, standardized connecting elements for the connection of the electrical connection elements A can be used. Consequently, mixed forms can also be provided so that, for example, a combined electrical connection and cross-connection element A, Q is used on one side of a prestressed concrete element SE, while a separate connection element A is used on another side.

As in 7 shown in view of the side surface F ₂ and F ₄ , the electrical connection A can be arranged to an electrically conductive clamping element of the reinforcement S in a recess AN in the side surface F ₂ , F ₄ . This is also in perspective 1 shown. The recess AN makes it possible, for example, to protect the connection element A protected for the transport of a prestressed concrete element SE. In 6 For example, the connection element A on the right side already out of the recess out, for example, folded, while on the left side, the connection element A is still stored in the recess AN.

The electrically conductive connection of the prestressed electrically conductive clamping elements, e.g. Steel strands or wires, with the connections A and possibly existing electrical cross-connections Q may i.a. not welded for static reasons. Therefore, non-thermally effective bonding methods are preferably used.

It is particularly simple e.g. a clamping connection produced, since this does not violate the structure of the strands and cables and their static properties are not deteriorated.

Exemplary clamp connections which can be used for the invention are based on screw connectors or press connectors, whereby no high demands are placed on them.

Thus, e.g. high demands are placed on the corrosion resistance of such connectors, so that inexpensive materials can be used. Among other things, this is due to the circumstance that, when installed as intended, the all-round covering with concrete provides sufficient permanent corrosion protection.

In the following, a possible manufacturing method of such prestressed concrete elements SE with integrated equipotential bonding will now be described.

The invention is equally suitable for production by means of so-called concrete extrusion process or by means of so-called slip pavers.

In a first step, a reinforcement S is introduced, wherein the reinforcement S has one or more electrically conductive clamping elements in the longitudinal direction of the prestressed concrete element SE.

The introduced electrically conductive clamping elements S, e.g. Steel strands or wires are pretensioned with a tensioning device between the beginning and end of a concrete band or concrete strand BS or the static requirements, this step possibly taking place after introduction of connection elements A and / or possible electrical cross connections Q. can.

In a further step, at least one electrical connection to an electrically conductive clamping element of the reinforcement S is produced at at least one point with a laterally branching connection element A, wherein the electrical connection to at least one of the side surfaces F ₁ , F ₂ , F ₃ , F _{4 of} the prestressed concrete element SE is contactable. An electrical connection may be made by suitable bonding techniques as discussed above.

In a further step, a concrete raw material for enclosing the reinforcement S and the electrical connection A is introduced in the tensioned state of the introduced electrically conductive clamping elements.

Optionally, the inventive method further comprises the step of sawing the prestressed concrete element SE in the transverse direction to the reinforcement S. In the 2 to 5 this is indicated, for example, by the dashed lines, which indicate individual prestressed concrete elements SE in a concrete strand BS. At these points, for example, after reaching the early strength of the concrete strand BS this can be cut, for example, with diamond saws to the required lengths L ₁ , L ₂ , L ₃ .

In this method, there is thus no possibility in the longitudinal direction of any connection elements A for equipotential bonding conductors to emerge from the elements, since they would also be cut off during cutting to the required length L ₁ , L ₂ , L ₃ .

Nevertheless, remain for this purpose, the two longitudinal sides F ₂ , F ₄ , which later form the joint edges FU and also form the space for the on-site reinforcement to be introduced BB, see 6 ,

Preferably, the connecting elements A are introduced prior to the introduction of the concrete in a pocket-like recess AN, which lies within the part of a line production traveled by the machine path. As a result, the manufacturing process of the entire concrete strand BS can be done without being affected by protruding connection elements A.

The connection elements A and the recesses AN provided for this purpose are to be introduced from the planned sawing cross sections in the direction of the finished element.

Such recesses may preferably be introduced in statically neutral areas, in which no or only small static forces are absorbed. In this way, the lead-out of the connection elements A requires no recalculation of the ceiling slab statics.

The low mass fraction of the introduced transverse connector Q and the respective electrical connections and the (two-sided) connection elements A is insignificant compared to the mass of the introduced concrete and causes no significant influence on the previous statics.

Preferably, the connection elements A remain during storage in the manufacturing operation and during transport to the construction site in the recesses AN.

At the place of use, the connection elements A can be retrieved from the recesses AN and bent over in the direction of any existing ring beam or ring anchor. This can be done by hand or by means of suitable tools and can be done directly on the ceiling to be built.

After all prestressed concrete elements SE have been designed, the connection elements A can be connected to the equipotential bonding system in the ring beam or ring anchor.

As a result, a close-meshed equipotential bonding system can be produced.

By incorporating the impedances of the prestressed wires, which are connected in segments by electrical cross-connections, the impedance between the ceiling elements combined by the equipotential bonding conductor PA is considerably reduced. This is exemplary in 8th shown.

These prestressed concrete elements SE can also be designed for prestressed concrete ceilings as an insulated ceiling with integrated thermal insulation, as a climate ceiling with integrated piping systems for transporting heating or cooling energy or as a ventilation ceiling with special design of individual hollow chambers designed.

Unless otherwise indicated, the term electrical connection includes an electrically conductive connection.

Furthermore, the side surfaces illustrated in the aforementioned embodiments are only exemplary, so that, for example, the arrangement of the connection elements A on each of the sides F ₁ and / or F ₂ and / or F ₃ and / or F _{4 is} readily possible.

The invention fulfills the requirements for a future-proof low-impedance and current-carrying equipotential bonding system.

The invention allows the effort for material, working hours and planning issues drastically reduced.

LIST OF REFERENCE NUMBERS

• BS

  concrete strand

  SE

  prestressed concrete element

  S

  Reinforcement, electrically conductive clamping elements

  Q

  Cross connection element

  A

  Electrical connection, connection element

  d _Q

  Distance from cross connection elements

  L ₁ , L ₂ , L ₃

  Length of a prestressed concrete element

  BB

  On-site reinforcement

  MR

  cavity

  AT

  recess

  F ₁ , F ₂ , F ₃ , F ₄

  faces

  FU

  Gap

  PA

  Bonding conductors

  Z

  part impedance

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited non-patent literature

• DIN 1045-1: 2001-07 [0003]
• DIN 1053-1: 1996-11 [0003]

Claims (7)

Prestressed concrete element (SE) with integrated equipotential bonding comprising a reinforcement (S), which is surrounded by concrete, wherein the prestressed concrete element (SE) essentially has a panel-like configuration, wherein the panel-like configuration in each case two substantially parallel aligned side surfaces (F ₁ , F ₂ , F ₃ , F ₄ ), wherein the reinforcement (S) has one or more electrically conductive clamping elements in the longitudinal direction of the prestressed concrete element (SE), and the prestressed concrete element (SE) further comprises at least one electrical connection (A) to an electrically conductive clamping element the reinforcement (S) which can be contacted on at least one of the side surfaces (F ₁ , F ₂ , F ₃ , F ₄ ) of the prestressed concrete element (SE).  Prestressed concrete element (SE) according to claim 1, wherein the reinforcement (S) comprises a plurality of electrically conductive clamping elements, and wherein at least two of the electrically conductive clamping elements with each other in electrical connection (Q).  Prestressed concrete element (SE) according to claim 1 or 2, wherein the reinforcement (S) has a plurality of electrically conductive clamping elements, and wherein at least two of the electrically conductive clamping elements with each other at at least two different locations (Q) within the prestressed concrete element (SE) in electrical connection stand.  Prestressed concrete element (SE) according to claim 2 or 3, wherein the electrical connection (A) to an electrically conductive clamping element of the reinforcement (S) simultaneously brings at least two of the electrically conductive clamping elements in electrical connection (Q). Prestressed concrete element (SE) according to one of the preceding claims, wherein the electrical connection (A) to an electrically conductive clamping element of the reinforcement (S) in a recess (AN) in the side surface (F ₁ , F ₂ , F ₃ , F ₄ ) is. Method for producing a prestressed concrete element (SE) with integrated equipotential bonding comprising a reinforcement (S) which is surrounded by concrete, wherein the prestressed concrete element (SE) essentially has a panel-like configuration, wherein the panel-like configuration in each case has two substantially parallel aligned side surfaces (FIG. F ₁ , F ₂ , F ₃ , F ₄ ), comprising the steps of: • introducing a reinforcement (S), wherein the reinforcement (S) has one or more electrically conductive clamping elements in the longitudinal direction of the prestressed concrete element (SE), • producing at least an electrical connection to an electrically conductive clamping element of the reinforcement (S) at at least one point with a laterally branching connection element (A), wherein the electrical connection to at least one of the side surfaces (F ₁ , F ₂ , F ₃ , F ₄ ) of the prestressed concrete element (SE) is contactable, • introducing a concrete raw mass for enclosing the reinforcement (S) and the electrical connection (A).  The method of claim 6, further comprising the step of sawing the prestressed concrete element (SE) transversely of the reinforcement (S).

Images