EP2096220B1 - Prestressed hollow board element - Google Patents

Abstract

The method involves arranging parallel web plates (3) with reciprocal gaps in the cavity between upper and lower plates (11,12) of the hollow plate element, where a cavity is lined with concrete column strips. The strips are formed with multiple wave-type bracing cables (2) over the longitudinal axis of the column strips. The bracing cables are installed parallel to the longitudinal direction of the web plates. An independent claim is included for a hollow slab element.

Description

The invention relates to a method for producing a hollow plate element with a large span and low height and a hollow plate element produced by the method.

An initially mentioned hollow plate member is connected to the subject of DE 103 50 082 A1 known. In the embodiment shown there is a prestressed flat ceiling with hollow ceiling panels. In the space between a relatively thin upper and lower plate in this case belt strips were poured concrete, in the inner area of a number of tensioning cables were laid. The tension cables were waved over the longitudinal axis of the belt strips and thus incorporated into the concrete of the belt strips.

By applying a bias to the respective end faces of these tension cables, the effect has been to deflect the tension forces acting on the tension cables longitudinally to bias the bottom plate toward the top plate. This resulted in the advantage that a high load-bearing capacity could be achieved with a relatively thin and slender construction of such hollow ceiling slabs.

Disadvantage of said arrangement, however, was that the pouring of belt strips with concrete caused a relatively high cost. Another disadvantage was that the laid in concrete tensioning cables were difficult to install, because appropriate tension cable holder were required and their installation state could not be checked later. It could be achieved with this construction - because of the weight of the belt strips - no high spans. So it was not possible to achieve spans over 10 m, because the forces in the belt strip then exceeded the permissible level.

The method was in the known document DE 103 50 082 A1 the disadvantage that the belt strip with the inserted there and wavy out Clamping cables had to be made at the site of the site, which was associated with a high production cost at the site.

The EP 1350898 A1 discloses a method for producing a hollow panel element with all the features of the preamble of method claim 1.

The EP 1790789 A1 discloses a method for producing a hollow plate element, wherein at first a connecting of the web construction with a first plate and then connecting the upper and the lower plate takes place.

The invention is therefore based on the object, a hollow plate element according to the subject matter of the prior art so that with improved processability, a larger span at the same or even lower basis weight can be achieved with high load capacity. Another object is to achieve an improvement in the distance between the upper and lower concrete slab, as well as a bias in the web construction of the hollow plate element.

To achieve the object, the invention is characterized by a method according to the subject of claim 1.

An essential feature of the invention is that a hollow plate element according to the invention is characterized in that a plurality of mutually spaced and mutually parallel web plates are arranged in the space between an upper and a lower plate, parallel to the longitudinal direction of the tension cables are laid, wherein each tensioning cable is connected at one end via an anchor body with the respective web plate, while the opposite end of the tensioning cable is connected via another anchor body with the end of the web plate lying there.

With the given technical teaching, there is the significant advantage that now the belt strips made of concrete to be prepared beforehand at the site of the construction site can be completely eliminated and instead already produced in the precast concrete factory Web plates are poured into the space between the upper and lower plate and that parallel to these web plates now clamping cables according to the invention are stretched.

This results in the advantage that a much lower basis weight is achieved because the relatively heavy belt strips of concrete account for and are replaced by lightweight webs.

The invention is not dependent on the web plates extending over the entire length of the hollow plate elements. Although this is a preferred embodiment of the invention. In another embodiment of the invention However, it is provided that the web plates are only partially available and in particular only at the respective end faces of the hollow plate elements are arranged and then only only a maximum of twice in the region of the deflection, where the clamping force of the respective tensioning cable is introduced into the cross section of the lower plate.

The arranged in the central region web plates then serve as Umlenksattel for the introduction of the laid in the bow or belly tensioning cable in the cross section of the lower plate.

With the measures according to the invention a substantially improved hollow plate element is achieved for the first time, because with such a lightweight construction, it is now possible to achieve spans of over 16 m, with a hollow plate element has a length of 16 m and a width of 3.50 m.

Each plate of this sandwich construction (upper and lower plate) in this case has a preferred thickness of z. B. 10 cm.

The gap is then in this embodiment about 20 cm.

Such spans of hollow elements have hitherto not been produced manufacturing technology. It is now possible for the first time to produce these hollow plate elements in the precast concrete factory.

The sandwich panels, consisting of two parallel thin concrete slabs and their selective connection via steel elements (web plates) are manufactured industrially. First, a plate is produced together with the steel elements. In this case, the tensioning cable is already fixed along the web plate and fastened with the anchor bodies on the anchor plate. After the first plate has already hardened, it is immersed in the concrete of the second plate. After hardening of this shell, the sandwich cross-section is completely made. Now, the clamping force can be applied to the respective clamping cable and anchored at the end of the component.

The structure of the hollow plate element according to the invention is as follows:

Single web plates connect the top and bottom panels of the sandwich construction to transfer the thrust. Along the web plates a bias is arranged without composite (with monostrand tendons). The web plates provide the ideal conditions for the attachment of possible deflection saddles and for the anchoring elements.

On the anchoring plates of the anchor body is placed for the bias. The Monolitzenspanglieder are guided parallel along the concrete bridge. The bias occurs after the two plates are bonded together and cured.

About the anchoring plates as head elements on the web plates, the clamping force is introduced into the concrete web and then on the web plates in the concrete slabs.

With the object of the invention there is the advantage that now the tensioning cables no longer have to be laid wave-shaped in a belt strip made of concrete, but they are designed as a simple monolayer cable and go with their bulbous deflection in the cross section of the lower plate and are there anchored.

In order to achieve a defined transfer of the clamping forces on the lower plate, it is provided that at the entry points of the tensioning cable in the cross section of the lower plate so-called Umlenksattel are present to initiate the clamping forces of the cable in the cross section of the lower plate.

Thus, a sagging belly of the tensioning cable is no longer generated in the side view of the tensioning cable, but a trapezoidal guidance of the tensioning cable between the opposing anchorage bodies.

This saves considerable weight, because in the simplest case, only web plates corresponding to the deflecting saddles have to be provided, which provide a connection to the upper plate.

Such web plates do not necessarily consist of a metal element. They can also be made as a concrete element or as a plastic element or fiberglass concrete. Likewise, any composite body made of concrete and metal can be used.

When only piecewise use of web plates, the further advantage is achieved that the space between the sandwich panels is completely kept free of internals and the space for the installation of heating pipes, installation pipes and other elements is available.

If, on the other hand, a web plate extending over the entire length of the hollow panel element is used, it expediently has perforations and recesses at specific locations in order to allow passage of installation tubes and cables therethrough.

With the specified measures, it is now possible in a simple manner to control the deflection of the entire plate, because in a preferred embodiment, the voltage on the tensioning cables is adjusted so that the deflection of the tensioning cable corresponds to the total weight of the entire hollow plate element. Thus, this hollow plate element is statically defined at rest and has no deflection and then only has to absorb the resulting traffic load deflection. For this purpose, the web elements according to the invention are then provided.

It is essential here that a zero deflection of the hollow plate element is adjusted due to the applied voltage of the tensioning cable and thereby creep of the concrete after curing is avoided when pressure is applied to the concrete.

By using the web plates according to the invention, the force is transmitted from the upper plate to the lower and both are thus evenly loaded and protected by the bias of the tensioning cable against deflection. In the following, the invention will be explained in more detail with reference to drawings showing only one embodiment,

Figur 1:

Draufsicht auf ein Hohlplattenelement nach der Erfindung

Figur 2:

Schnitt gemäß der Linie 1-1 in Figur 2

Figur 3:

Schnitt gemäß der Linie 2-2 in Figur 1

Figur 4:

eine vergrößerte Seitenansicht aus dem Schnitt nach Figur 3

Figur 5:

Schnitt gemäß der Linie 1-1 in Figur 4

Figur 6:

ein gleicher Schnitt in Richtung 1-1 bei einem in Plattenmitte angeordneten Stegblech

Figur 7:

eine vergrößerte Darstellung eines in Plattenmitte verlegten Stegbleches gemäß Figur 2

Show it:

FIG. 1:

Top view of a hollow plate element according to the invention

FIG. 2:

Section according to the line 1-1 in FIG. 2

FIG. 3:

Section according to the line 2-2 in FIG. 1

FIG. 4:

an enlarged side view from the section to FIG. 3

FIG. 5:

Section according to the line 1-1 in FIG. 4

FIG. 6:

a same section in the direction 1-1 at a arranged in the middle of the plate web plate

FIG. 7:

an enlarged view of a laid in the middle of the plate web plate according to FIG. 2

In FIG. 1 consists of the hollow plate element 1 of two spaced apart and mutually parallel plates 11, 12, wherein in FIG. 1 the top view on the upper plate 11 is shown. It can be seen that in the central region of the hollow plate element 1, two mutually parallel and mutually spaced clamping cables 2 are guided, in the central region of a likewise parallel guided web plate 3 is guided.

At the outer end faces of the hollow plate element 1 only single clamping cable 2 are guided only, wherein the FIG. 2 shows that with the help of a filling body 4, the connection to the adjacent hollow plate element 1 is achieved.

The hollow plate member 1 has in the space between the upper and lower plates 11, 12 cavities 5, in which, for example, an insulation 8 is laid. In this cavity 5 and common installation cables, heating and cooling pipes and the like are laid. Likewise, it is provided to lay in the cross section of the lower plate 12 and heating or cooling lines.

It is important that in the connection area, i. H. in the area of concrete webs 7 of the hollow plate member 1, a web plate 3 is laid, which consists essentially of a double-T cross-section. This web plate 3 has a vertical leg 34, which extends over a first preferred embodiment over the entire length of the hollow plate element 1.

In another embodiment, this web plate 3 is only partially available.

On the vertical legs 34 of the web plate 3 seen at a mutual distance in the longitudinal direction of the hollow plate member 1, a number of head bolts 6 are fixed, each having a head 29 of enlarged cross-section at their outer free ends.

The head bolts 6 are preferably made of a metal material, as well as the vertical leg 34 of the web plate. 3

The head bolts 6 are then in this case preferably secured with a weld on the vertical leg 34 of the web plate 3.

Purpose of this head bolt 6 is to provide a positive connection between the upper plate 11 and the lower plate 12 via the vertical leg 34 of the web plate 3, which is laid in the illustrated embodiment in the region of a concrete web 7.

Between the abutting hollow plate elements 1 results according to FIG. 2 below the filling body 4, a gap 9, which represents the parting line between the hollow plate elements 1.

How out FIG. 1 can be seen, the tensioning cable 2 are each received at the ends of the hollow plate elements 1 in anchor bodies 10.

According to FIG. 4 Each anchor body 10 consists of the anchor plate 19, through which the cable outline 21, consisting of individual strands 25 is passed. These strands 25 are guided beyond the anchor plate 19 by an anchor bushing 16, deflected there in an arc and engage through a fixing plate 17 and are anchored in a cone receptacle 18. In this way, there is an immovable fixing of the strands 25 of the tensioning cable 2 in the anchor bushing sixteenth

The adjustment of the bias voltage to the tensioning cable 2 takes place when the two plates are connected and cured according to the specified method. It is then handled with a corresponding pulling tool on the backward strands 25 and the strands are high Tensile force stretched along its longitudinal direction, then turned over and anchored in the cone seat 18 of the anchor plate 16.

The Figures 3 and 4 show that the hollow plate member 1 rests at its ends in each case by a construction designed as a double support 13 construction.

If an over the entire length extending web plate 3 is used, it is according to FIG. 4 provided that there openings 14, 15 are provided to pass through corresponding insulation cable and cables.

If, according to one embodiment, the concrete web 7 is attached in order to enclose the web plate 3 with the anchor bodies 10 arranged thereon on the front, the cable outline 21 of the anchor body 10 is still surrounded by a helical reinforcement 20 in order to absorb splitting tensile forces.

In FIG. 4 Incidentally, it can be seen that the upper edge 23 of the web plate 3 does not extend to the outer edge of the upper plate 11, and also the lower edge 22 of the web plate does not extend to the bottom of the lower plate 12. This space is covered with concrete and in the area of the upper and lower plates are according to FIG. 7 Longitudinal and transverse reinforcements 26, 27 arranged.

The FIG. 7 also shows that in the lower plate heating cables 28 are arranged, which can be traversed by a heating or a cooling medium.

The FIG. 3 shows the basic principle of the invention, from which it can be deduced that essentially the tensioning cable assumes a trapezoidal shape 33 when it is introduced into the lower plate, wherein deflecting saddles 32 are preferably provided at the deflection points 31 in the region of the lower plate, which guides the cable guide of the tensioning cable 2 take there and thus provide the desired trapezoidal shape 33.

Upon application of a clamping force on the tensioning cable 2 after FIG. 3 Thus, the entire hollow plate member 1 is raised and biased in the direction of arrow 30.

The bias voltage is - as stated in the general description part - adjusted so that there is a zero deflection of the unloaded hollow plate elements 1. The arranged in the space between the upper and lower plate web plates 3 then need only record the traffic-related load and deflection of the hollow plate elements 1.

drawing Legend

1

Hollow panel member

2

span cable

3

web plate

4

Verfüllkörper

5

cavity

6

studs

7

concrete bridges

8th

isolation

9

Gap

10

anchor body

11

Upper plate

12

Lower plate

13

support

14

Opening (web plate 3)

15

Opening (web plate 3)

16

anchor bush

17

fixing

18

cone holder

19

anchor plate

20

Wendel reinforcement

21

cable outline

22

Bottom edge of web plate

23

Top edge web plate

24

gap

25

braid

26

transverse reinforcement

27

longitudinal reinforcement

28

heating

29

Head (head bolt 6)

30

arrow

31

turning point

32

deviator

33

trapezoidal shape

34

vertical thigh

Claims (7)

1. Method for producing a hollow slab member (1) which forms a hollow space (5) between upper and lower arranged concrete slabs (11, 12), which are formed in the inner region thereof with a number of bracing cables (2) laid over the longitudinal axis of concrete webs (7), a plurality of members (3), which assume a mutual spacing and are formed mutually parallel, and parallel to the longitudinal direction of which the bracing cables (2) are laid, being arranged in the hollow space (5) between the upper and lower concrete slabs (11, 12) of the hollow slab member (1), characterised in that the members (3) are web plates (3), one end of each bracing cable (2) being connected via an anchoring body (10) to the respective web plate (3) whilst the opposite end of the bracing cable (2) is connected via a further anchoring body (10) to the end of the web plate (3) positioned there, the production of a hollow slab member (1) comprising the following steps:

   - attaching anchoring members (6, 16-20) and deflection saddles (32) to the web plate (3);

   - connecting the web plates (3) to the upper or lower concrete slab (11, 12);

   - introducing bracing cables (2) parallel to the web plate (3);

   - connecting the upper concrete slab (11) to the lower concrete slab (12);

   - biasing the bracing cable (2) after connecting and hardening the two concrete slabs (11, 12) by introducing a tension into the concrete web (7), via the web plates (3) into the concrete slabs (11, 12).
2. Method for producing a hollow slab member (1) according to claim 1, characterised in that the bracing cable (2) is anchored to a convex deformation in the lower concrete slab (12) via the deflection saddles (32) and forms a trapezium-shaped guide for the bracing cable (2).
3. Hollow slab member (1) produced by the method according to either of the preceding claims 1 or 2, characterised in that only individual bracing cables (2) are guided on the outer end faces of the hollow slab member (1) and the hollow slab member (1) is attached to an adjacent hollow slab member (1) via a backfill body (4), a joint (9) being formed below the backfill body (4) as a parting line between the adjacent hollow slab members (1).
4. Hollow slab member (1) according to claim 3, characterised in that the web plate (3) has a double-T cross-section having a vertical leg (34), the web plate (3) extending over the entire length of the hollow slab member (1).
5. Hollow slab member (1) according to claim 4, characterised in that the vertical leg (34) of the web plate (3) has head bolts (6) which are spaced apart in the longitudinal direction, each have a head (29) of enlarged cross-section at the free ends thereof, and are formed of a metal material, the head bolts (6) being fastened to the vertical leg (34) by a welded joint.
6. Hollow slab member (1) according to claim 5, characterised in that the head bolts (6) form a positive connection between the upper concrete slab (11) and the lower concrete slab (12) of the hollow slab member (1) via the vertical leg (34), arranged in the region of the concrete web (7), of the web plate (3).
7. Hollow slab member (1) according to any one of the preceding claims 1 to 6, characterised in that the anchoring body (10) comprises an anchoring plate (19) through which the cable outline (21) comprising the individual cords (25) is guided, the cords (25) on the far side of the anchoring plate (19) being guided by an anchoring socket (16), being deflected in an arc, passing through a fixing plate (17) and being anchored in a conical recess (18) and thus forming a permanent fastening of the bracing cables (2) in the anchoring socket (16).

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