(19)
(11)EP 3 221 530 B1

(12)EUROPEAN PATENT SPECIFICATION

(45)Mention of the grant of the patent:
27.02.2019 Bulletin 2019/09

(21)Application number: 15798032.7

(22)Date of filing:  19.11.2015
(51)Int. Cl.: 
E04C 5/12  (2006.01)
E04C 5/07  (2006.01)
(86)International application number:
PCT/EP2015/077040
(87)International publication number:
WO 2016/079214 (26.05.2016 Gazette  2016/21)

(54)

A REINFORCEMENT SYSTEM AND A METHOD OF REINFORCING A STRUCTURE WITH A TENDON

VERSTÄRKUNGSSYSTEM UND VERFAHREN ZUR VERSTÄRKUNG EINER STRUKTUR MIT EINEM SPANNGLIED

SYSTÈME DE RENFORT ET PROCÉDÉ DE RENFORCEMENT D'UNE STRUCTURE AVEC UN TENDON


(84)Designated Contracting States:
AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR

(30)Priority: 21.11.2014 EP 14194291

(43)Date of publication of application:
27.09.2017 Bulletin 2017/39

(73)Proprietor: Danmarks Tekniske Universitet
2800 Kgs. Lyngby (DK)

(72)Inventor:
  • SCHMIDT, Jacob Wittrup
    DK-2100 Copenhagen Ø (DK)

(74)Representative: Guardian IP Consulting I/S 
Diplomvej, Building 381
2800 Kgs. Lyngby
2800 Kgs. Lyngby (DK)


(56)References cited: : 
WO-A1-02/103137
KR-A- 20090 041 017
WO-A1-03/062551
  
      
    Note: Within nine months from the publication of the mention of the grant of the European patent, any person may give notice to the European Patent Office of opposition to the European patent granted. Notice of opposition shall be filed in a written reasoned statement. It shall not be deemed to have been filed until the opposition fee has been paid. (Art. 99(1) European Patent Convention).


    Description


    [0001] The present invention relates to a structure, such as concrete structure, with a reinforcement system for anchoring tendons for structural reinforcing the structure, said reinforcement system comprises at least one anchor and at least one tendon, said anchor is adapted to fix said tendon in and/or outside said structure.

    Background of the invention



    [0002] Ductility of structures is important to ensure large deformation and give sufficient warning while maintaining an adequate load capacity before structure failure. Concrete is a brittle material. Concrete structures rely largely on the deformation and yielding of the tensile reinforcement to satisfy the ductility demand.

    [0003] The application of high strength steel reinforcement in concrete structures has less ductility due to the lower degree of strain hardening and smaller elongation of the tensile reinforcement.

    [0004] The application of fiber reinforced polymer (FRP) reinforcement has a similar problem, as FRP have a low strain capacity and linear elastic stress-strain behavior up to rupture without yielding.

    [0005] Thus, the ductility of concrete members reinforced with non-ductile tendons, especially FRP reinforced concrete members, decreases due to the tensile reinforcement deforms less and hence a lower deformability and ductility is achieved.

    [0006] US2014/0123593 discloses a method of improving the ductility of a structural member, such as a reinforced concrete beam or column reinforced by tensile members made of high strength steel or FRP, by providing a region of increased compression yielding in the compression zone of a plastic hinge region or nearby. This can be achieved by forming a mechanism provided in the compression zone to provide the ductile compression zone.

    [0007] US6082063 discloses an anchorage for a tendon that includes a sleeve having a smooth tapered interior bore and a compressible wedge disposed in the sleeve. The compressible wedge has a smooth exterior tapered surface tapering from a wider end to a narrower end and one or more interior channels for receiving a tendon. The taper angle of the compressible wedge is greater than the taper angle of the bore. Thus, upon insertion of the compressible wedge into the sleeve, the wider end of the compressible wedge forms a wedge contact with the sleeve before the narrower end forms a wedge contact with the sleeve. Hereby is achieved an appropriate anchorage system for FRP tendons.

    [0008] WO 02/103137 A1 discloses a structure with a reinforcement system according to the preamble of claim In many cases, it is desirable to provide an improved structural ductility of high strength steel or FRP reinforced concrete members.

    Brief description of the invention



    [0009] It is an object of the present invention is to provide an improved ductility of reinforced structural members.

    [0010] This is achieved by a structure according to independent claim 1 with a reinforcement system comprising a ductility element, which is positioned in structural connection between said tendon and said anchor, said ductility element comprising weakened deformation zones, said weakened deformation zones are configured for increasing the ductility of said reinforcement system, said weakened deformation zones being deformable and thereby said weakened deformation zones are configured for allowing the length of deformation zones on the ductility element to increase or decrease in an axial direction along the length of said tendon, when the stress on the ductility element exceeds a certain level.

    [0011] This results in the ductility element by elongation or compression increases the ductility in the reinforcement system.

    [0012] In an embodiment, said ductility element comprises multiple deformable zone positioned subsequent in an axial direction along the length of said tendon, thus providing subsequent deformable zones, enabling a sequence of ductility.

    [0013] Hereby is achieved that each deformation zone, when it collapses, only gives rise to a limited length reduction of the complete ductility element, and thereby the ductility element can initially adapt to small variations in the mounting of the tendon and the anchor, and thereafter provide the required ductility due to the remaining undeformed deformation zones.

    [0014] The ductility element comprises a through going channel, said through going channel being disposed internally within the one or more deformable zones for receiving said tendon, the through going channel being disposed such that the tensile force on the tendon during use are oriented along the extension of the through going channel.

    [0015] Hereby is achieved that all the deformation zones are subjected to the same force applied by the stress in the tendon, and the weakest deformation zone will thereby collapse first.

    [0016] In an embodiment, the reinforcement system is configured such that the force required for deformation of the ductility element in axial load is less than the force required for deformation of the tendon.

    [0017] In an embodiment, the ductility element is configured such that the force required for deformation of the ductility element in axial load being about 30-95%, preferably 70-95 % of the force required for deformation of said tendon.

    [0018] In an embodiment, the ductility element is an integrated part of said anchor.

    [0019] In a further embodiment, said ductility element comprises a circular cross section and said anchor comprises a barrel having a smooth tapered interior bore and a compressible wedge adapted to be disposed in said barrel.

    [0020] In a further embodiment, said ductility element is positioned at one extremity of said anchor as an extension of the barrel.

    [0021] In another embodiment, said ductility element comprises a rectangular cross section and said internal channel comprises a rectangular cross section for the lead through of a tendon having a corresponding rectangular cross section.

    [0022] The present invention further relates to a method of reinforcing a structure according to independent claim 9 with a tendon, comprising fixing the tendon to the structure at different positions, and where the tendon is fixed to the structure by using ductility elements at each position, an where each ductility element is weakened at local deformation zones, and thereby deforms when the stress on the ductility element exceeds a certain level so that the length of the deformation zone on the ductility element is increased or decreased in an axial direction along the length of said tendons.

    [0023] The term tendon should be understood as any type of reinforcement element of steel or fibers, such as FRP cable or rods, e.g. carbon, aramid or glass fiber reinforced polymer, although other material also may be used.

    Brief description of the drawings



    [0024] Embodiments of the invention will be described in the following with reference to the drawings wherein

    Fig. 1 illustrates a ductility element in connection with a barrel and wedge anchor,

    Fig. 2 is a schematic view of a ductility element,

    Fig. 3 is a schematic view of a ductility element, a cross sectional view of the ductility element in a line indicated by B, and an end view of the ductility element,

    Fig. 4 is a perspective view of a T-shaped structure,

    Fig. 5 is a side view of the T-shaped structure shown in figure 4,

    Fig. 6 is a schematic side view of another embodiment of a ductility element,

    Fig. 7 is a side view and a top view of the ductility element illustrated in fig. 5,

    Fig. 8 is a perspective view of a T-shaped structure,

    Fig. 9 illustrates a bottom view of the T-shaped structure illustrated in fig. 7, and a cross sectional view of the T-shaped structure in the line indicated by H, the sub section of the T-structure indicated by J is illustrated in fig. 9 in an enlarged view,

    Fig. 10 is an enlarged side view of the sub section of the cross sectional view of the T-shaped structure which is shown in fig 8, in fig. 8 the sub section is indicated by J,

    Fig. 11 illustrates three embodiments of the ductility element.


    Detailed description of the invention with reference to the figures



    [0025] The present invention relates to a reinforcement system for anchoring tendons for structural reinforce a structure such as a concrete structure.

    [0026] Figure 1 illustrates a reinforcement system which comprises an anchor (50) adapted to fasten a tendon and a ductility element (10) within a structure.

    [0027] The anchor (50) is schematically illustrated as a known type of an anchor comprising a barrel (52) and wedge (51), wherein the barrel has a tapered interior bore and the compressible wedge being adapted to be coaxially disposed in the barrel. The tendon (40) extends through the center of the wedge, which is wedged coaxially inside the barrel for clamping the tendon (40), and thereby anchoring the tendon in a structure.

    [0028] Furthermore, the reinforcement system comprises a ductility element (10), which is positioned in structural connection between said tendon (40) and said anchor (50), said ductility element comprises weakened deformation zones being deformable in axial direction along the length of said tendons. The deformation zones are weakened in relation to the other part of the ductility element.

    [0029] The ductility element is configured such that the force required for deformation of the ductility element in axial load is less than the force required for deformation of the tendon. Thus, the ductility element (10) has a ductile phase in axial load less than the tensile strength of the tendons, thus making the ductility element the weakest link in the reinforcement system. The ductility element (10) will reach its strength before the other components of the reinforcement system. When the stress excides the threshold of the ductility of the ductility element, the ductility element will deform and it thus provide ductility to the reinforcement system.

    [0030] As concrete is a brittle material. Concrete structures rely on the deformation and yielding of the tensile reinforcement to satisfy the ductility demand.

    [0031] By employing a ductility element in combination with tendons made of high strength steel or fiber lacking of sufficient ductility by allowing the ductility element to deform and thus provide an increased ductility.

    [0032] Figure 2 illustrates a first embodiment of the ductility element (10).

    [0033] The ductility element comprises a first end (11), a second end (12), two deformable walls (14,16) and a through going channel (13) adapted for receiving a tendon, the through going channel extends centrally internal through said ductility element, from said first end (11) to the far side of the second end (12) thereby both deformable walls are subjected to the same force applied by the stress in the tendon, and the weakest one will thereby collapse first.

    [0034] The two deformable walls (14,16) are divided into sequential zones by a partition (15).

    [0035] As the two deformable walls (14,16) has varying thickness enables the ductility element to deform upon loads, and as illustrated in figure 2, the weakened deformable walls are able to deform in radial direction in respect of the centerline of the ductility element and the fluctuation of the deformable wall are illustrated by dotted lines (60,61) in the figure 2.

    [0036] The ductility element is prefabricated and may be cast directly into a structural member, such as a concrete structure, or applied to the structural member afterwards. Furthermore, the reinforcement system may be used inside a concrete structure as well as on the outside of the structure, and as the tendons and ductility element may be made of non-corrosive material, thus it is suitable for being used in more aggressive environments.

    [0037] Figure 3 is a schematic view of a ductility element as illustrated in figure 2. Figure 3 additionally illustrates a cross sectional view of the ductility element in a line indicated by B, and an end view showing the ductility element (10) having a circular cross section and a centrally circular through going channel (13), which extends coaxially within the ductility element.

    [0038] A T-shaped structure (30) illustrated in a perspective view is shown in figure 4, comprising visibly three reinforcement systems, two anchorage system internal positioned in the center of the T-shaped structure covered by caps (32) and one anchorage system mounted externally in a sup structure (31). The reinforcement system in the sub structure (31) extends from the sub structure and outside both structures (30,31).

    [0039] The same structure (30) is illustrated in figure 5 as a side view.

    [0040] Figure 5 illustrates the two reinforcement system comprising a ductility element (10) internal positioned at one extremity of the T-shaped structure. The additional structure (31) comprises a ductility element (10) coupled to the tendons inside the sub structure, and having the tendon extends through the sub structure and outside both structures. The three reinforcement systems are covered by a cap (32).

    [0041] Another embodiment of the ductility element (110) is illustrated in figure 6.

    [0042] The ductility element (110) comprises a first end (111), a second end (112), four deformable walls (114,116,118,120) and a through going channel (113) adapted for receiving a tendon, the through going channel extends centrally internal through the ductility element, from the first end (111) to the second end (112).

    [0043] The through going channel (113) is adapted for flat tendons having a rectangular cross section.

    [0044] The four deformable walls (114,116,118,120) are divided into sequential zones by the partitions (115,117,119), defining four compression zones.

    [0045] The lead through of a tendon in the thought going channel (113) disposed within the one or more deformable zone, the through channel being disposed such that the tensile force on the tendon during use are oriented along the through going channel (113) within the ductility element (110).

    [0046] The four deformable walls (114,116,118,120) by having varying thickness are weakened and therefore able to deform, when the ductility element being loaded.

    [0047] The weakened deformation zones are deformable so that the length of the ductility element is increased or decreased in an axial direction along the length of a tendon.

    [0048] In figure 6 the deformation of the weakened deformable walls are illustrated by dotted lines. During increasing pressure the ductility element will, when threshold for elastic deformation is reached, start to deform followed by a deformation resulting in a collapse.

    [0049] The ductility element (110) has a ductile phase in axial load less than the tensile strength of the tendons, thus making the ductility element the weakest link in the reinforcement system, and the ductility element (110) will reach its strength before the other components of the reinforcement system.

    [0050] The ductility element will deform when the stress excides the threshold of the ductility element, and it thus provides ductility to the reinforcement system. Thus ductility is achieved by applying a ductility element to the reinforcement system.

    [0051] The embodiment of the ductility element (110) shown in figure 6 is shown as a side view and a top view in figure 7.

    [0052] In figure 7 the ductility element (110) comprises a first end (111), a second end (112), four deformable walls (114,116,118,120) and a through going channel (113) adapted for receiving a tendon, the through going channel extends centrally internal through said ductility element, from said first end (111) to the second end (112). The four deformable walls (114,116,118,120) are divided into sequential zones by the partitions (115,117,119), defining four compression zones.

    [0053] The second end (112) cooperates with an anchor for fixing the tendon to provide a structural connection between the ductility element and the tendon.

    [0054] The above mentioned embodiment of the ductility element (110) is incorporated in a reinforcement system in a structure (130) having a T-shaped cross section illustrated in figure 8 and 9.

    [0055] The ductility element (110) is positioned inside the T-shaped structure (130) just below the surface of the structure and is secured by a cover part (132). A flat tendon (140) leads through the structure and extend beyond the extremity of the structure (130).

    [0056] Figure 9 illustrates a bottom view of the T-shaped structure, and a cross sectional view of the T-shaped structure in the line indicated by H, the sub section indicated by J is illustrated in figure 10 in an enlarged view.

    [0057] The enlarged side view of the reinforcement system, shown in figure 10, comprises a ductility element (110) and a tendon (140), which is fixed by an anchor (150) at one extremity of the ductility element (110).

    [0058] Figure 11 illustrates three embodiments of the weakened deformable zones of a ductility element (30).

    [0059] The weakened deformation zones may be provided by slits (14a), holes (14b), such as voids or bubbles, varying thickness of the deformable walls, and/or by use of a material providing a deformable zone. The deformation walls (14c) may be adapted to deform along the periphery of the ductility element in tangential direction.

    [0060] The weakened deformation zones are weakened in relation to the other parts of the ductility element. The weakened deformation zones may also be provided by suitable choice of material.

    [0061] The ductility element may be made of metal such as steel or aluminum, cementitious material, plastics, or elastic material such as rubber, composite material or combination thereof.


    Claims

    1. A structure (30, 31, 140), such as a concrete structure, with a reinforcement system for anchoring tendons (40, 140) for structural reinforcing the structure, said reinforcement system comprises at least one anchor (50, 150) and at least one tendon (40, 140), said anchor is adapted to fix said tendon in and/or outside said structure characterized in that said reinforcement system comprises a ductility element (10, 110), which is positioned in structural connection, between said tendon (40, 140) and said anchor (50, 150), said ductility element (10, 110) comprising weakened deformation zones, said weakened deformation zones are configured for increasing the ductility of said reinforcement system, said weakened deformation zones being deformable and thereby said weakened deformation zones are configured for allowing the length of deformation zones on the ductility element (10, 110) to increase or decrease in an axial direction along the length of said tendon (40, 140), when the stress on the ductility element (10, 110) exceeds a certain level, in that the ductility element (10, 110) comprises a first end (11, 111), a second end (12, 112) and a through going channel (13, 113), said through going channel being disposed internally within the one or more deformable zones and said tendon (40, 140) being received in said through going channel (13, 113), the through going channel being disposed such that the tensile force on the tendon (40, 140) during use are oriented along the extension of the through going channel (13, 113), so that all the deformation zones are subjected to the same force applied by the stress in the tendon (40, 140), and the weakest deformation zone will thereby collapse first, in that the first end (11, 111) of the ductility element (10, 110) cooperates with the structure (30, 31, 140) for transferring the load from said tendon (40, 140), and in that the second end (12, 112) of the ductility element (10, 110) cooperates with the anchor (50, 150) for fixing the tendon (40, 140), thereby providing a structural connection between the ductility element (10, 110) and the tendon (40, 140).
     
    2. A structure with a reinforcement system according to claim 1, wherein said ductility element (10, 110) comprises multiple deformable zones positioned subsequent in an axial direction along the length of said tendon (40, 140), thus providing subsequent deformable zones, enabling a sequence of ductility.
     
    3. A structure with a reinforcement system according to any one or more of the preceding claims, wherein the ductility element (10, 110) is configured such that the force required for deformation of the ductility element (10, 110) in axial load is less than the force required for deformation of the tendon (40, 140), and wherein the ductility element (10, 110) has a ductile phase in axial load less than the tensile strength of the tendons (40, 140).
     
    4. A structure with a reinforcement system according to any one or more of the preceding claims, wherein said ductility element (10, 110) is configured such that the force required for deformation of the ductility element (10, 110) in axial load being about 30-95 %, preferably 70-95 % of the force required for deformation of said tendon (40, 140).
     
    5. A structure with a reinforcement system according to any one or more of the preceding claims, wherein the ductility element (10, 110) is an integrated part of said anchor (50, 150).
     
    6. A structure with a reinforcement system according to any one or more of the preceding claims, wherein said ductility element (10) comprises a circular cross section and said anchor (50) comprises a barrel (52) having a tapered interior bore and a compressible wedge (51) adapted to be disposed in said barrel (52).
     
    7. A structure with a reinforcement system according to any claim 6, wherein said ductility element (10) is positioned at one extremity of said anchor (50) as an extension of the barrel (52).
     
    8. A structure with a reinforcement system according to any one or more of the claims 1-5, wherein said ductility element (110) comprises a rectangular cross section and said internal channel (113) comprises a rectangular cross section for the lead through of a tendon having a corresponding rectangular cross section.
     
    9. A method of reinforcing a structure with a reinforcement system according to any one of the preceding claims, comprising fixing the tendon (40, 140) to the structure at different positions, and where the tendon (40, 140) is fixed to the structure (30, 31, 140) by using ductility elements (10, 110) at each position, an where each ductility element (10, 110) is weakened at local deformation zones, and thereby deforms when the stress on the ductility element (10, 110) exceeds a certain level so that the length of the deformation zone on the ductility element (10, 110) is increased or decreased in an axial direction along the length of said tendons (40, 140).
     


    Ansprüche

    1. Struktur (30, 31, 140), wie beispielsweise eine Betonstruktur, mit einem Verstärkungssystem zum Verankern von Vorspanngliedern (40, 140) zum strukturellen Verstärken der Struktur, wobei das Verstärkungssystem mindestens einen Anker (50, 150) und mindestens ein Vorspannglied (40, 140) umfasst, wobei der Anker geeignet ist, das Vorspannglied innerhalb und/oder außerhalb der Struktur zu befestigen, dadurch gekennzeichnet, dass das Verstärkungssystem ein duktiles Element (10, 110) umfasst, welches in struktureller Verbindung zwischen dem Vorspannglied (40, 140) und dem Anker (50, 150) positioniert ist, wobei das duktile Element (10, 110) geschwächte Verformungszonen umfasst, wobei die geschwächten Verformungszonen konfiguriert sind, um die Duktilität des Verstärkungssystems zu erhöhen, wobei die geschwächten Verformungszonen verformbar sind und dadurch die geschwächten Verformungszonen konfiguriert sind, um zu ermöglichen, dass die Länge der Verformungszonen auf dem duktilen Element (10, 110) entlang der Länge des Vorspannglieds (40, 140) in axialer Richtung zunimmt oder abnimmt, wenn die Belastung des duktilen Elements (10, 110) ein bestimmtes Niveau überschreitet, dadurch dass das duktile Element (10, 110) ein erstes Ende (11, 111), ein zweites Ende (12, 112) und einen Durchgangskanal (13, 113) umfasst, wobei der Durchgangskanal intern innerhalb der einen oder mehreren verformbaren Zonen angeordnet ist und das Vorspannglied (40, 140) in dem Durchgangskanal (13, 113) aufgenommen wird, wobei der Durchgangskanal so angeordnet ist, dass die Zugkraft auf dem Vorspannglied (40, 140) während des Gebrauchs entlang der Verlängerung des Durchgangskanals (13, 113) ausgerichtet ist, so dass alle Verformungszonen der gleichen Kraft ausgesetzt sind, die durch die Spannung in dem Vorspannglied (40, 140) aufgebracht wird, und die schwächste Verformungszone dabei zuerst zusammenbricht, indem das erste Ende (11, 111) des duktilen Elements (10, 110) mit der Struktur (30, 31, 140) zusammenwirkt, um die Last vom Vorspannglied (40, 140) zu übertragen, und indem das zweite Ende (12, 112) des duktilen Elements (10, 110) mit dem Anker (50, 150) zusammenwirkt, um das Vorspannglied (40, 140) zu fixieren, wodurch eine strukturelle Verbindung zwischen dem duktilen Element (10, 110) und dem Vorspannglied (40, 140) bereitgestellt wird.
     
    2. Struktur mit einem Verstärkungssystem nach Anspruch 1, wobei das duktile Element (10, 110) mehrere verformbare Zonen umfasst, die nacheinander in axialer Richtung entlang der Länge des Vorspannglieds (40, 140) angeordnet sind, wodurch nachfolgende verformbare Zonen bereitgestellt werden, die eine Reihenfolge von Duktilität ermöglichen.
     
    3. Struktur mit einem Verstärkungssystem nach einem oder mehreren der vorstehenden Ansprüche, wobei das duktile Element (10, 110) so konfiguriert ist, dass die für die Verformung des duktilen Elements (10, 110) unter axialer Last erforderliche Kraft geringer ist als die für die Verformung des Vorspanngliedes (40, 140) erforderliche Kraft, und wobei das duktile Element (10, 110) eine duktile Phase unter axialer Last aufweist, die geringer ist als die Zugfestigkeit der Vorspannglieder (40, 140).
     
    4. Struktur mit einem Verstärkungssystem nach einem oder mehreren der vorstehenden Ansprüche, wobei das duktile Element (10, 110) so konfiguriert ist, dass die für die Verformung des duktilen Elements (10, 110) unter axialer Last erforderliche Kraft etwa 30-95 %, vorzugsweise 70-95 % der für die Verformung der des Vorspanngliedes (40, 140) erforderlichen Kraft beträgt.
     
    5. Struktur mit einem Verstärkungssystem nach einem oder mehreren der vorstehenden Ansprüche, wobei das duktile Element (10, 110) ein integrierter Bestandteil des Ankers (50, 150) ist.
     
    6. Struktur mit einem Verstärkungssystem nach einem oder mehreren der vorstehenden Ansprüche, wobei das duktile Element (10) einen kreisförmigen Querschnitt umfasst und der Anker (50) einen Zylinder (52) mit einer sich verjüngenden Innenbohrung und einen komprimierbaren Keil (51) umfasst, der zur Anordnung in dem Zylinder (52) geeignet ist.
     
    7. Struktur mit einem Verstärkungssystem nach einem beliebigen Anspruch 6, wobei das duktile Element (10) an einem Ende des Ankers (50) als Verlängerung des Zylinders (52) positioniert ist.
     
    8. Struktur mit einem Verstärkungssystem nach einem oder mehreren der Ansprüche 1-5, wobei das duktile Element (110) einen rechteckigen Querschnitt aufweist und der Innenkanal (113) einen rechteckigen Querschnitt für die Durchführung eines Vorspanngliedes mit einem entsprechenden rechteckigen Querschnitt aufweist.
     
    9. Verfahren zum Verstärken einer Struktur mit einem Verstärkungssystem nach einem der vorstehenden Ansprüche, umfassend das Fixieren des Vorspanngliedes (40, 140) an der Struktur an verschiedenen Positionen, und wobei die Sehne (40, 140) an der Struktur (30, 31, 140) unter Verwendung von duktilen Elementen (10, 110) an jeder Position fixiert wird, und wobei jedes duktile Element (10, 110) an lokalen Verformungszonen geschwächt ist und sich dadurch verformt, wenn die Belastung des duktilen Elements (10, 110) ein bestimmtes Niveau überschreitet, so dass die Länge der Verformungszone auf dem duktilen Element (10, 110) in axialer Richtung entlang der Länge der Vorspannglieder (40, 140) zunimmt oder abnimmt.
     


    Revendications

    1. Structure (30, 31, 140), telle qu'une structure de béton, avec un système de renfort pour ancrer des armures (40, 140) pour le renforcement structurel de la structure, ledit système de renfort comprenant au moins une ancre (50, 150) et au moins une armure (40, 140), ladite ancre étant à même de fixer ladite armure dans et/ou en dehors de ladite structure, caractérisée en ce que ledit système de renfort comprend un élément de ductilité (10, 110) qui est positionné en liaison structurelle entre ladite armure (40, 140) et ladite ancre (50, 150), ledit élément de ductilité (10, 110) comprenant des zones de déformation affaiblies, lesdites zones de déformation affaiblies sont configurées pour augmenter la ductilité dudit système de renfort, lesdites zones de déformation affaiblies étant déformables et, par suite, lesdites zones de déformation affaiblies sont configurées pour pouvoir augmenter ou diminuer la longueur des zones de déformation sur l'élément de ductilité (10, 110) dans une direction axiale sur la longueur de ladite armure (40, 140) lorsque l'effort sur l'élément de ductilité (10, 110) dépasse un certain niveau, l'élément de ductilité (10, 110) comprend une première extrémité (11, 111), une seconde extrémité (12, 112) et un canal traversant (13, 113), ledit canal traversant étant disposé intérieurement dans les une ou plusieurs zones déformables et ladite armure (40, 140) étant reçue dans ledit canal traversant (13, 113), le canal traversant étant disposé de sorte que la force de traction sur l'armure (40, 140) en cours d'utilisation soit orientée sur l'extension du canal traversant (13, 113) de sorte que toutes les zones de déformation soient soumises à la même force appliquée par l'effort dans l'armure (40, 140) et que la zone de déformation la plus faible s'affaisse ainsi en premier, la première extrémité (11, 111) de l'élément de ductilité (10, 110) coopère avec la structure (30, 31, 140) pour transférer la charge de ladite armure (40, 140) et la seconde extrémité (12, 112) de l'élément de ductilité (10, 110) coopère avec l'ancre (50, 150) pour fixer l'armure (40, 140), en sorte de fournir une liaison structurelle entre l'élément de ductilité (10, 110) et l'armure (40, 140).
     
    2. Structure avec un système de renfort selon la revendication 1, dans laquelle ledit élément de ductilité (10, 110) comprend de multiples zones déformables positionnées à la suite dans une direction axiale sur la longueur de ladite armure (40, 140), fournissant de la sorte des zones déformables ultérieures permettant une séquence de ductilité.
     
    3. Structure avec un système de renfort selon l'une quelconque ou plusieurs des revendications précédentes, dans laquelle l'élément de ductilité (10, 110) est configuré de sorte que la force requise pour la déformation de l'élément de ductilité (10, 110) en charge axiale soit inférieure à la force requise pour la déformation de l'armure (40, 140) et dans laquelle l'élément de ductilité (10, 110) a une phase ductile en charge axiale inférieure à la résistance à la traction des armures (40, 140).
     
    4. Structure avec un système de renfort selon l'une quelconque ou plusieurs des revendications précédentes, dans laquelle ledit élément de ductilité (10, 110) est configuré de sorte que la force requise pour la déformation de l'élément de ductilité (10, 110) en charge axiale se situe aux environs de 30 à 95 %, de préférence de 70 à 95 % de la force requise pour la déformation de ladite armure (40, 140).
     
    5. Structure avec un système de renfort selon l'une quelconque ou plusieurs des revendications précédentes, dans laquelle l'élément de ductilité (10, 110) est une partie intégrée de ladite ancre (50, 150).
     
    6. Structure avec un système de renfort selon l'une quelconque ou plusieurs des revendications précédentes, dans laquelle ledit élément de ductilité (10) comprend une section transversale circulaire et ladite ancre (50) comprend un cylindre (52) ayant une alésage intérieur conique et une clavette compressible (51) qui est à même d'être disposée dans ledit cylindre (52).
     
    7. Structure avec un système de renfort selon la revendication 6, dans laquelle ledit élément de ductilité (10) est positionné à une extrémité de ladite ancre (50) en tant qu'extension du cylindre (52).
     
    8. Structure avec un système de renfort selon l'une quelconque ou plusieurs des revendications 1 à 5, dans laquelle ledit élément de ductilité (110) comprend une section transversale rectangulaire et ledit canal interne (113) comprend une section transversale rectangulaire pour le conducteur à travers une armure ayant une section transversale rectangulaire correspondante.
     
    9. Procédé de renfort d'une structure avec un système de renfort selon l'une quelconque des revendications précédentes, comprenant la fixation de l'armure (40, 140) à la structure dans différentes positions et dans lequel l'armure (40, 140) est fixée à la structure (30, 31, 140) en utilisant des éléments de ductilité (10, 110) dans chaque position, et dans lequel chaque élément de ductilité (10, 110) est affaibli dans des zones de déformation locales et se déforme donc lorsque l'effort sur l'élément de ductilité (10, 110) dépasse un certain niveau de sorte que la longueur de la zone de déformation sur l'élément de ductilité (10, 110) soit augmentée ou réduite dans une direction axiale sur la longueur desdites armures (40, 140).
     




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    REFERENCES CITED IN THE DESCRIPTION



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    Patent documents cited in the description