EP1532331B1 - Method for applying tension members to supporting structures, and device for carrying out said method - Google Patents

Abstract

Process for mounting a pre-stressed band-like tension element (1) on a supporting framework (3), especially a concrete supporting framework, comprises pre-stressing the tension element at at least one end using a tensioning device via a temporary clamping anchor (4) fixed on the tension element, and anchoring the tension element on the supporting framework using a permanent anchoring device. The tension element is pre-stressed via the temporary anchor at a distance from the surface (2) of the supporting framework. The tension element is pressed onto the surface by at least one permanent anchor clamp (6). An Independent claim is also included for a device used for carrying out the above process. Preferred Features: The temporary clamping anchor is removed after the tension element is pressed onto the surface.

Description

The invention relates to a method for attaching tensioned band-shaped tension members to supporting structures (3), in particular concrete structures, wherein the tension member is tensioned at least one end by means of a tensioning device via a temporary tension anchor attached to the tension member and then attached to the structure.

To increase the sustainability (upgrading) or restore the original capacity (rehabilitation) of structures, especially concrete structures made of reinforced concrete or prestressed concrete, it is known to subsequently attach to the surface of the structure band-shaped tension members, preferably lamellar tension members made of plastic with fibers embedded for reinforcement , especially carbon fibers. If these tension members anchored in the prestressed state, the load capacity and serviceability are also significantly improved. For this it is known ( DE 198 49 605 A1 ), the flush-mounted band-shaped tension members to anchor on steel base plates, which are embedded in the concrete surface.

Similarly, structures made of steel or wood components can be rehabilitated or upgraded.

The production of the necessary recess in the concrete surface in the area of anchoring devices is expensive and can cause damage to the concrete embedded reinforcement. To make matters worse, that this necessary recess depends on the tension-side end of the tension member not only on the size of the base plate provided for permanent anchoring, but also on the tensioning of the tensioning device arranged there. These recesses are therefore relatively large for long tension members that require a larger tension travel. The remaining in the concrete structure base plate increases the cost of anchoring the tension members.

In a known method of the type mentioned ( PATENT ABSTRACTS OF JAPAN vol. 1999, no. 12 (1999-10-29 ) JP 11 182061 A (1999-07-06 )) is glued by means of a separate tensioning device tension member in the prestressed state on the structural surface. The ends of the tension member are held by Endbefestigungsblechen to prevent peeling. The power transmission between the tension member and the structure is done exclusively by gluing.

The object of the invention is to provide a method of the type mentioned in such a way that the anchoring surface-flush tension members is substantially simplified.

This object is achieved by the method claimed in claim 1.

Since the tension member is at a distance to the surface of the structure during the tensioning process, the ends of the tension member can be secured to the temporary tension anchor on a lying under the tension member clamping plate of the temporary tension anchor by clamping, without that for this clamping plate a recess in the surface of the structure would have to be made. By the subsequent pressing of the tension member to the surface by means of a permanent anchor bracket, the non-positive connection between the tension member and the supporting structure is produced, wherein the band-shaped tension member is now arranged flush with the surface. The introduction of the clamping force takes place by utilizing the pressing force of the anchor bracket, so that the arranged between the anchor bracket and the end of the tension member temporary tension anchor can be removed.

This eliminates the need to provide a base plate remaining on the structure and to produce a recess for countersinking this base plate. Thus, the method also new applications are developed in which from the outset recesses for the base plate and the clamping path are not possible, so that even a transfer of the method to steel structures or wooden structures is possible.

Another particular advantage of the method according to the invention is that it can also be used in coveted structures, in particular concrete structures, for example, roadway plates in bridge construction, wherein the tension of the tension members can be initiated directly at the edge of the Voutung. This is not possible in the conventional manner for attaching tensioned band-shaped tension members to concrete structures. At least on the tension armature side, the tensioning force can not be introduced directly to the haunch because the clearance required for the tensioner would extend too far into the haunch area and possibly pierce the haunch reinforcement.

In development of the invention it is provided that the tension member between two fixed at both ends of the tension member temporary tension anchors is stretched at a distance from the surface of the structure and that the tension member is then pressed close to its two ends by means of a respective permanent anchor bracket on the surface.

The invention also relates to a device for carrying out the method. Starting from a known device ( DE 198 49 605 A1 ) with a band-shaped tension member which is connected at at least one end with a temporary tension anchor, with a tensioning device acting on the temporary tensioning anchor during the tensioning operation and with a permanent anchoring device, the device according to the invention is characterized by the features of claim 4.

Compared to the known device, the device according to the invention is much cheaper, because no permanent clamping plates remain on the structure and because this no recesses must be provided in the surface.

The band-shaped tension member can be pressed directly onto the surface. In an embodiment of According to the invention it is also possible to arrange an adhesive layer between the tension member and the surface of the structure and / or the anchor bracket, which cures after pressing the tension member to the surface.

The adhesive layer increases the force-transmitting connection between the tension member and the surface or the anchor bracket.

It is also possible to glue a friction-increasing and / or load-distributing intermediate layer in the region of the anchor bracket.

Further advantageous embodiments of the inventive concept are the subject of further subclaims.

• Fig. 1 in vereinfachter Darstellungsweise ein Betontragwerk mit einem im Abstand zur Betonoberfläche angeordneten vorgespannten Zugglied,
• Fig. 2 einen Schnitt entsprechend der Fig. 1, nachdem das Zugglied mittels Ankerklammern gegen die Betonoberfläche gedrückt wurde,
• Fig. 3 in einem Schnitt entsprechend den Fig. 1 und 2 die Anordnung des bandförmigen Zugglieds an der Betonoberfläche nach dem Entfernen der temporären Spannanker,
• Fig. 4-6 in Darstellungen entsprechend den Fig. 1-3 die Verfahrensschritte bei Anwendung bei einem gevouteten Betontragwerk,
• Fig. 7 einen vergrößerten Schnitt längs der Linie VII-VII in Fig. 2,
• Fig. 8 in einem Schnitt entsprechend der Fig. 3 eine Ausführung mit einer zwischen dem Zugglied und der Betonoberfläche angeordneten Kleberschicht,
• Fig. 9 einen vergrößerten Schnitt längs der Linie IX-IX in Fig. 8 und
• Fig. 10-12 abgewandelte Ausführungsformen in Schnitten entsprechend der Fig. 9.

The invention will be explained in more detail by exemplary embodiments, which are illustrated in the drawing.
Show it:

• Fig. 1 in a simplified representation a concrete structure with a spaced apart from the concrete surface prestressed tension member,
• Fig. 2 a cut according to the Fig. 1 after the tension member has been pressed against the concrete surface by anchor brackets,
• Fig. 3 in a cut according to the Fig. 1 and 2 the arrangement of the band-shaped tension member on the Concrete surface after removal of the temporary tension anchors,
• Fig. 4-6 in representations according to the Fig. 1-3 the process steps when applied to a haunched concrete structure,
• Fig. 7 an enlarged section along the line VII-VII in Fig. 2 .
• Fig. 8 in a section corresponding to the Fig. 3 an embodiment with an adhesive layer arranged between the tension member and the concrete surface,
• Fig. 9 an enlarged section along the line IX-IX in Fig. 8 and
• Fig. 10-12 modified embodiments in sections corresponding to Fig. 9 ,

A band-shaped tension member 1 ( Fig. 1 ) is provided for attachment to a concrete surface 2 of a concrete structure 3 to increase the current carrying capacity. For this purpose, the first arranged at a distance a to the concrete surface 2 of the concrete structure 3 tension member 1 is attached at its two ends to a temporary tension anchor 4, wherein a lower clamping plate 5 of the temporary tension anchor whose thickness is equal to the distance a, between the bottom the tension member 1 and the concrete surface 2 comes to rest.

Then, by mutual tensioning of the temporary tensioning anchor 4, the required biasing force is applied to the tension member 1. Preferably, in this case one of the two temporary tensioning anchors 4 is fixed to the concrete structure 3, while the other temporary tensioning anchor 4 by means of a tensioning device (not shown), as for example from the DE 198 49 605 A1 is known to be biased to the extent necessary.

Then, in each case an anchor bracket 6 is attached at a short distance in front of each of the two temporary clamping anchor 4, which - because it later remains on the concrete structure 3 - is referred to in this context as a permanent anchor bracket 6. The permanent anchor bracket 6 ( Fig. 7 ) is pressed by means of both sides of the tension member 1 embedded in the concrete structure 3 bolts 7 and 8 clamping nuts so on the tension member 1 that this tension member 1 is pressed against the concrete surface 2. The applied pressure force causes a frictional connection between the prestressed, flush-mounted tension member 1 and the concrete surface. 2

Then the two temporary clamping anchors are removed after pressing the tension member 1 on the concrete surface 2 ( Fig. 3 ).

In the Fig. 4-6 that the Fig. 1-3 , it is shown that the described method steps for attaching the tension member 1 to a concrete structure 3 can also be performed when the concrete surface 2 'at the two ends of the concrete structure 3 each one Voutung 2'a has, ie a relative to the flat central region of the concrete surface 2 'increasing region. The two temporary tensioning anchors 4 are located in the area of the haunch 2'a, without any need for a recess in the surface area of the concrete structure 3.

In the manner already described above, the tension member 1 is pressed by the permanent anchor brackets 6 to the concrete surface 2 '( Fig. 5 ). Then the temporary tension anchors 4 are removed ( Fig. 6 ).

In both described embodiments, when removing the temporary tensioning anchors 4, the deflecting force which is produced when the anchor clamps 6 are pressed against the anchoring of the anchor clamp 6 on the one hand and on the clamping plate 5 of the temporary tension anchor 4 on the other hand, is brought into contact pressure between the anchor clamp 6 and the concrete structure 3 redistributed. As a result, the tension member 1 between the concrete surface 2 and 2 'and the anchor bracket 6 is clamped.

As in the 8 and 9 is shown, an adhesive layer 9 can be arranged between the tension member 1 and the concrete surface 2, which cures after pressing the tension member 1 on the concrete surface 2.

In Fig. 10 It is shown that in addition between the tension member 1 and the anchor bracket 6, an adhesive layer 10 may be arranged, which cures after pressing the tension member 1 on the concrete surface 2.

According to the embodiment Fig. 11 is in the region of the anchor bracket 7 on the tension member 1 by means of the adhesive layer 10, a friction-increasing and / or load-distributing intermediate layer 11 bonded, for example made of steel.

Fig. 12 shows a further embodiment in which the anchor bracket 6 has on its upper side a stiffening rib 12 which serves to produce a uniform clamping pressure. Instead or in addition, a spring-like load distribution plate may be arranged on the anchor bracket 6.

Claims (9)

1. Method for applying tensioned strip-like tension members (1) to surfaces of supporting structures (3), in particular concrete supporting structures, wherein the tension member (1) is tensioned at at least one end by means of a tensioning device via a temporary tensioning anchor (4) fastened to the tension member (1), and is then fastened to the supporting structure (3), characterized in that the tension member (1) is tensioned at a distance (a) from the surface (2) of the supporting structure (3) via a tensioning plate (5) of the temporary tensioning anchor (4) that is arranged between the tension member (1) and the surface of the supporting structure, and in that the tension member (1) is then pressed onto the surface (2) and connected in a force-locking manner thereto by means of at least one permanent anchor clamp (6) which engages over the tension member (1) close to the temporary tensioning anchor (4).
2. Method according to Claim 1, characterized in that the tension member (1) is tensioned at a distance (a) from the surface (2) between two temporary tensioning anchors (4) fastened to both ends of the tension member (1), and in that the tension member (1) is then pressed close to its two ends onto the surface (2) by means of a respective permanent anchor clamp (6).
3. Method according to Claim 1 or 2, characterized in that the temporary tensioning anchor (4) or the two temporary tensioning anchors (4) is or are removed after the tension member (1) has been pressed onto the surface (2).
4. Apparatus for carrying out the method according to one of Claims 1-3, with a supporting structure (3) and a strip-like tension member (1) which is to be applied thereto and which is connected at at least one end to a temporary tensioning anchor (4), with a tensioning device acting on the temporary tensioning anchor (4) during the tensioning operation, and with a permanent anchoring device, wherein the tensioning plate (5) of the temporary tensioning anchor (4) is arranged between the tension member (1) and the surface (2) of the supporting structure, and wherein the apparatus comprises at least one anchor clamp (6) which engages over the tension member (1) close to the temporary tensioning anchor (4) and can be pressed against the surface (2) to obtain the force-locking connection.
5. Apparatus according to Claim 4, characterized in that an adhesive layer (9) which hardens after the tension member (1) is pressed onto the surface (2) is arranged between the tension member (1) and the surface (2).
6. Apparatus according to Claim 4 or 5, characterized in that an adhesive layer (10) which hardens after the tension member (1) is pressed onto the surface (2) is arranged between the tension member (1) and the anchor clamp (6).
7. Apparatus according to Claim 4, characterized in that a friction-increasing and/or load-distributing intermediate layer (11) is adhesively bonded to the tension member (1) in the region of the anchor clamp (6).
8. Apparatus according to Claim 4, characterized in that the anchor clamp (6) is provided on its upper side with at least one reinforcing rib (12).
9. Apparatus according to Claim 4, characterized in that spring-like load distribution plates are arranged on the anchor clamp (6).

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