WO2001020097A1 - Systeme d'ancrage recevant les forces de traction de tirants renforces de fibres de carbone - Google Patents

Systeme d'ancrage recevant les forces de traction de tirants renforces de fibres de carbone Download PDF

Info

Publication number
WO2001020097A1
WO2001020097A1 PCT/CH2000/000498 CH0000498W WO0120097A1 WO 2001020097 A1 WO2001020097 A1 WO 2001020097A1 CH 0000498 W CH0000498 W CH 0000498W WO 0120097 A1 WO0120097 A1 WO 0120097A1
Authority
WO
WIPO (PCT)
Prior art keywords
anchoring
cfrp
band
clamping
anchoring system
Prior art date
Application number
PCT/CH2000/000498
Other languages
German (de)
English (en)
Inventor
Mehdi Farshad
Original Assignee
Eidgenössische Materialprüfungs- und Forschungsanstalt Empa
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Eidgenössische Materialprüfungs- und Forschungsanstalt Empa filed Critical Eidgenössische Materialprüfungs- und Forschungsanstalt Empa
Publication of WO2001020097A1 publication Critical patent/WO2001020097A1/fr

Links

Classifications

    • E—FIXED CONSTRUCTIONS
    • E04—BUILDING
    • E04C—STRUCTURAL ELEMENTS; BUILDING MATERIALS
    • E04C5/00—Reinforcing elements, e.g. for concrete; Auxiliary elements therefor
    • E04C5/08—Members specially adapted to be used in prestressed constructions
    • E04C5/12—Anchoring devices
    • E04C5/127—The tensile members being made of fiber reinforced plastics
    • E—FIXED CONSTRUCTIONS
    • E01—CONSTRUCTION OF ROADS, RAILWAYS, OR BRIDGES
    • E01D—CONSTRUCTION OF BRIDGES, ELEVATED ROADWAYS OR VIADUCTS; ASSEMBLY OF BRIDGES
    • E01D19/00—Structural or constructional details of bridges
    • E01D19/14—Towers; Anchors ; Connection of cables to bridge parts; Saddle supports
    • E—FIXED CONSTRUCTIONS
    • E04—BUILDING
    • E04C—STRUCTURAL ELEMENTS; BUILDING MATERIALS
    • E04C5/00—Reinforcing elements, e.g. for concrete; Auxiliary elements therefor
    • E04C5/07—Reinforcing elements of material other than metal, e.g. of glass, of plastics, or not exclusively made of metal
    • E—FIXED CONSTRUCTIONS
    • E04—BUILDING
    • E04G—SCAFFOLDING; FORMS; SHUTTERING; BUILDING IMPLEMENTS OR AIDS, OR THEIR USE; HANDLING BUILDING MATERIALS ON THE SITE; REPAIRING, BREAKING-UP OR OTHER WORK ON EXISTING BUILDINGS
    • E04G23/00—Working measures on existing buildings
    • E04G23/02—Repairing, e.g. filling cracks; Restoring; Altering; Enlarging
    • E04G23/0218—Increasing or restoring the load-bearing capacity of building construction elements
    • E04G2023/0251—Increasing or restoring the load-bearing capacity of building construction elements by using fiber reinforced plastic elements
    • E04G2023/0255—Increasing or restoring the load-bearing capacity of building construction elements by using fiber reinforced plastic elements whereby the fiber reinforced plastic elements are stressed
    • E—FIXED CONSTRUCTIONS
    • E04—BUILDING
    • E04G—SCAFFOLDING; FORMS; SHUTTERING; BUILDING IMPLEMENTS OR AIDS, OR THEIR USE; HANDLING BUILDING MATERIALS ON THE SITE; REPAIRING, BREAKING-UP OR OTHER WORK ON EXISTING BUILDINGS
    • E04G23/00—Working measures on existing buildings
    • E04G23/02—Repairing, e.g. filling cracks; Restoring; Altering; Enlarging
    • E04G23/0218—Increasing or restoring the load-bearing capacity of building construction elements
    • E04G2023/0251—Increasing or restoring the load-bearing capacity of building construction elements by using fiber reinforced plastic elements
    • E04G2023/0262—Devices specifically adapted for anchoring the fiber reinforced plastic elements, e.g. to avoid peeling off

Definitions

  • the present invention relates to an anchoring system to absorb the tensile forces of carbon fiber-reinforced tensile tapes, so-called CFRP tapes, be it to test their tensile strength behavior in the laboratory and to determine the breaking loads, or to absorb their tensile forces in the context of practical applications, that means to securely anchor the CFRP tapes.
  • CFRP tapes are unidirectionally reinforced with carbon fiber, which are manufactured as carbon fiber reinforced polymers. These tapes are tested in the laboratory area in widths of approximately 20mm, and based on the examination of their breaking loads, the dimensions for practical applications are then concluded.
  • CKF belts are characterized by the fact that they can withstand extremely high tensile forces and are therefore suitable for a large number of applications when such tensile forces occur and must be kept permanently and safely between two elements.
  • the tapes are initially pre-tensioned, after which they are absolutely tensile over a wide range of tensile forces and are attached to structures, for example as reinforcement tapes by means of an adhesive. The tapes are thus glued to structures in a pre-tensioned manner.
  • the weak points of the use of such a CFRP tape for absorbing tensile forces are always the ends with which they are anchored to the elements to be held together.
  • Rigid elements made of metal or a composite material are used as anchoring elements, with which the strips are then either glued or screwed.
  • the tensile strength behavior of various CFRP belts is meticulously examined in many laboratories worldwide in order to gain progress in the construction, material composition, dimensioning and design of such belts for practical applications. It is striking that in the case of breaking load examinations of such tapes, the weakest point is consistently in the anchoring elements, in that the tapes tear there from the edge area. When the tapes are glued to structures, the corners of the tape ends notoriously prove to be weak points, as the adhesive bond often breaks there.
  • the object of the present invention is therefore to provide an anchoring system for absorbing the tensile forces of carbon fiber reinforced tension bands (CFRP Tapes), which prevents the CFRP tape edges from tearing at the edges at the anchoring point or the loosening of the bonds at the corners of the CFRP tapes.
  • CFRP Tapes carbon fiber reinforced tension bands
  • an anchoring system for absorbing the tensile forces of carbon fiber-reinforced tension bands which is characterized in that the front or rear or both boundary lines of the anchoring surface at the CFRP band end describe a curved line, such that that the effective length of the anchoring increases over the bandwidth from the tape edges and has a maximum in the area of the tape center.
  • CFRP bands carbon fiber-reinforced tension bands
  • anchoring which is carried out by means of clamping pieces, that is, by clamping the CFRP band end areas together under mechanical pressure in order to absorb the tensile forces
  • anchoring which is due solely to the band end areas being bonded to the strain on the train Element.
  • Figure 1 The clamping pieces of an anchoring element shown in a perspective view, with the end of a CFRP tape to be anchored;
  • Figure 2 An anchoring element with the two clamping pieces seen from the side shown in an elevation, with the CFRP tape held by him;
  • Figure 3 An anchoring element shown in plan from above, with a first variant for the geometric shape of the clamping tongue;
  • Figure 4 An anchoring element shown from above in the floor plan, with a second variant for the geometric shape of the clamping tongue;
  • Figure 5 An anchoring element shown in plan from above, with a third variant for the geometric shape of the clamping tongue.
  • FIG. 6 a tensile force diagram of a tension band anchored in a conventional manner
  • FIG. 7 A tensile force diagram of a tension band anchored in anchoring elements as shown in FIG. 5;
  • Figure 8 Different shape of the adhesive areas of a CFRP tape end.
  • Figure 1 first shows the two clamping pieces 1, 2 of an anchoring system acting by mechanical clamping.
  • the CFRP tape 3 to be anchored is indicated in front of the clamping piece 1.
  • the entire anchoring system preferably consists of two such identical clamping pieces 1, 2. These clamping pieces 1, 2 are made of stainless steel and mechanically finely machined in order to maintain an exact geometric shape.
  • the second clamping piece 2, which is to be placed here on the clamping piece 1, is placed on the clamping piece 1 in an inverted position and screwed to it, for which purpose the bores 4 are used.
  • the most important feature of these clamping pieces 1, 2 is the tongue 5 which extends forward in the pulling direction and which leads to a channeling of the pulling forces, so that the greatest pulling force in the middle of the belt is produced, while due to the geometry of this tongue 5, the tensile forces in the edge areas of the CFRP belt are reduced.
  • this tongue 5 has a smooth edge curve 6. Laboratory tests have shown that the use of such an anchoring system avoids tearing at the edges of the belt and, as a result, considerably greater tensile forces can be absorbed, the breaking point no longer having to lie with the clamping pieces 1, 2, but somewhere in the CFRP belt can lie. It proves to be particularly advantageous if the actual clamping surfaces 7, 8 run very slightly obliquely on the clamping pieces 1, 2.
  • Figure 2 shows the clamping pieces of the anchoring system seen from the side with the lower 1 and the upper clamping piece 2. You can see on the left the tongue 5 reaching out on both clamping pieces 1, 2nd The edges of the clamping surfaces 7, 8 of the two clamping pieces 1, 2 can only be seen on the tongues 5, and their course through the clamping pieces 1, 2 itself is shown in broken lines. However, the inclination or inclination of these clamping surfaces 7, 8 towards the clamping pieces 1, 2 is only a few parts per thousand, for example 10 parts per thousand. In combination with the geometric shape of the tongues 5, it is achieved that the tensile forces acting in the CKF band increase progressively towards the center of the band and reach their maximum in the band center.
  • the tensile force maxima of the CKF belts are thus much better utilized with this anchoring system than with previous anchors.
  • the belts can therefore be dimensioned smaller for the absorption of a certain required tensile force, or a certain band dimension can be used for greater tensile force requirements.
  • the screws 10 are also shown in FIG the clamping pieces 1,2 of the anchoring system are guided and tightened with lock nuts 11. So that fatigue of the clamping tongues 5 is prevented, they can be clamped together by means of separate clamping bridges 12, 13, which protrude beyond the tongues 5 on both sides, in that these bridges 12, 13 are clamped together in the same way with screws 14.
  • Figure 3 shows an anchoring system seen from above, that is shown in the floor plan to represent a special shape of the tongue edge 6.
  • the tongue 5 tapers relatively sharply here, but its tip 14 is quite rounded, so that the edge 6 of the tongue 5 forms a smooth curve everywhere. This avoids points of discontinuity and the tractive force curve in the clamped CFRP band is continuous everywhere.
  • an inclined arrangement of the clamping surfaces 7, 8 can at best be dispensed with, because the clamping force increases linearly due to the geometric shape of the tongue 5 towards the middle of the band and in the area of the tip thereof by a relatively sharp maximum leads.
  • Figure 4 shows a different geometric shape of the tongue 5 or the tongue edge 6.
  • the tongue edge 6 here forms a parabola. It causes a progressive increase in the tensile force acting towards the center of the clamped band. The force reaches a flattened maximum in the middle of the band. The progression of the tractive force progression over the bandwidth can be further increased by the clamping surfaces being at an oblique angle to one another, or by choosing a more pointed shape of the parabola.
  • Figure 5 shows a third variant for the shape of the tongue edge 6, which describes a semicircle here.
  • the tensile force acting in the clamped CFRP band increases continuously from the two minimas on the band edge towards the center of the band in order to achieve a maximum in the region of the band center.
  • the geometric shapes of the tongues and also with the slope of the clamping surfaces there are two possible variations for influencing the pulling force. Course across the bandwidth.
  • an optimized geometric shape can be selected.
  • FIG. 8 shows different shapes of the adhesive areas of a CFRP tape end.
  • Figure 8a) shows the conventional gluing over a rectangular area. Here the corners at the right end of the tape will peel off over time, after which the bond will gradually weaken starting from these corner areas.
  • Figure 8b) shows a first variant according to the new anchoring system.
  • FIG. 6 above first shows a traction force diagram at the clamping edge, as was determined in a CFRP tension band that was anchored in a conventional manner , namely between two rectangular clamping surfaces, which had a straight front edge running across the drawstring.
  • a clamping force diagram which shows the acting clamping forces in the free end area of the anchored CFRP tape clarify the entire end area of the anchored CFRP tape. Only at a certain distance from the clamping edge of the anchoring element, which extends along the upper edge of the diagram, do the acting clamping forces move over the entire range in approximately the same order of magnitude and are therefore evenly distributed.
  • Figure 7 shows a clamping force diagram, which illustrate the acting clamping forces in the free end area of a CFRP tape, which was anchored with the new anchoring system, which had an approximately semicircular clamping tongue. You can clearly see that the tension distribution is much more balanced and that a wide maximum is achieved in the area of the belt center.

Landscapes

  • Engineering & Computer Science (AREA)
  • Architecture (AREA)
  • Civil Engineering (AREA)
  • Structural Engineering (AREA)
  • Clamps And Clips (AREA)

Abstract

L'invention concerne un système d'ancrage caractérisé en ce que les extrémités de tirants renforcés de fibres de carbone ne sont pas coincées ou collées sur une zone rectangulaire mais en ce que les lignes de délimitation avant, arrière ou les deux de la surface d'ancrage décrivent une courbe, de sorte que la longueur efficace de l'ancrage augmente sur toute la largeur du tirant en partant des bords du tirant et présente un maximum dans la zone du milieu du tirant. Selon un mode de réalisation de l'invention, le système d'ancrage est constitué de deux éléments de serrage associés (1, 2) qui présentent des surfaces de serrage (7, 8) s'étendant sur toute la largeur du tirant renforcé de fibres de carbone à ancrer (3) et formant chacune une languette (5), orientée dans le sens de traction et dont le bord (6) décrit une courbe lisse. Les surfaces de serrage planes (7, 8) des deux éléments de serrage (1, 2) peuvent également être inclinées l'une par rapport à l'autre en direction du tirant renforcé de fibres de carbone à serrer (3). Grâce à l'élément d'ancrage, la courbe de force de serrage est uniforme sur la largeur du tirant enserré, empêchant ainsi une déchirure du tirant au niveau du bord.
PCT/CH2000/000498 1999-09-15 2000-09-15 Systeme d'ancrage recevant les forces de traction de tirants renforces de fibres de carbone WO2001020097A1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
CH01692/99A CH693616A5 (de) 1999-09-15 1999-09-15 Verankerungssystem zur Aufnahme der Zugkräfte von kohlefaserverstärkten Zugbändern (CFK-Bändern).
CH1692/99 1999-09-15

Publications (1)

Publication Number Publication Date
WO2001020097A1 true WO2001020097A1 (fr) 2001-03-22

Family

ID=4216385

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/CH2000/000498 WO2001020097A1 (fr) 1999-09-15 2000-09-15 Systeme d'ancrage recevant les forces de traction de tirants renforces de fibres de carbone

Country Status (2)

Country Link
CH (1) CH693616A5 (fr)
WO (1) WO2001020097A1 (fr)

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP1507051A1 (fr) * 2003-08-13 2005-02-16 Sika Technology AG Elément de transfert de force
EP1507050A1 (fr) * 2003-08-13 2005-02-16 Sika Technology AG Elément de transfert de force
CN105756288A (zh) * 2016-03-21 2016-07-13 宁波大学 一种碳纤维板锚具
CZ308302B6 (cs) * 2018-10-10 2020-04-29 ÄŚeskĂ© vysokĂ© uÄŤenĂ­ technickĂ© v Praze Přípravek pro předepnutí a kotvení kompozitních pásů a/nebo lamel ve zdivu
CZ308304B6 (cs) * 2018-11-02 2020-04-29 ÄŚeskĂ© vysokĂ© uÄŤenĂ­ technickĂ© v Praze Přípravek pro spřažení základových konstrukcí staveb

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB1208456A (en) * 1967-10-05 1970-10-14 Holzmann Philipp Ag Improvements in or relating to the anchoring of bracing wires
US3701554A (en) * 1968-11-26 1972-10-31 Coyne & Bellier Reinforcing and prestressing cable
DE29815064U1 (de) * 1998-08-24 1999-02-25 Betschart, Anton-Peter, Dr.-Ing. Architekt, 73087 Bad Boll Laschenkantenausbildung bei Stabankern zum Schutz von Beschichtungen
WO1999010613A1 (fr) * 1997-08-26 1999-03-04 Stresshead Ag Dispositif de renfort pour structures porteuses
DE19753318A1 (de) * 1997-12-02 1999-06-10 Sika Ag Verstärkungselement für lastaufnehmende oder lastübertragende Bauteile sowie Verfahren zu dessen Befestigung an einer Bauteiloberfläche
DE19828835C1 (de) * 1998-06-27 1999-07-29 Dornier Gmbh Zugstab zur Verwendung als Gurt für Brücken

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB1208456A (en) * 1967-10-05 1970-10-14 Holzmann Philipp Ag Improvements in or relating to the anchoring of bracing wires
US3701554A (en) * 1968-11-26 1972-10-31 Coyne & Bellier Reinforcing and prestressing cable
WO1999010613A1 (fr) * 1997-08-26 1999-03-04 Stresshead Ag Dispositif de renfort pour structures porteuses
DE19753318A1 (de) * 1997-12-02 1999-06-10 Sika Ag Verstärkungselement für lastaufnehmende oder lastübertragende Bauteile sowie Verfahren zu dessen Befestigung an einer Bauteiloberfläche
DE19828835C1 (de) * 1998-06-27 1999-07-29 Dornier Gmbh Zugstab zur Verwendung als Gurt für Brücken
DE29815064U1 (de) * 1998-08-24 1999-02-25 Betschart, Anton-Peter, Dr.-Ing. Architekt, 73087 Bad Boll Laschenkantenausbildung bei Stabankern zum Schutz von Beschichtungen

Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP1507051A1 (fr) * 2003-08-13 2005-02-16 Sika Technology AG Elément de transfert de force
EP1507050A1 (fr) * 2003-08-13 2005-02-16 Sika Technology AG Elément de transfert de force
WO2005021894A1 (fr) * 2003-08-13 2005-03-10 Sika Technology Ag Element inducteur de force, element de prolongation et procede d'augmentation de la charge de traction d'un matiere en forme de bande
US8881493B2 (en) 2003-08-13 2014-11-11 Sika Technology Ag Force application element, extension element, and a method for increasing the tensile load of a strip-shaped material
CN105756288A (zh) * 2016-03-21 2016-07-13 宁波大学 一种碳纤维板锚具
CN105756288B (zh) * 2016-03-21 2018-10-26 宁波大学 一种碳纤维板锚具
CZ308302B6 (cs) * 2018-10-10 2020-04-29 ÄŚeskĂ© vysokĂ© uÄŤenĂ­ technickĂ© v Praze Přípravek pro předepnutí a kotvení kompozitních pásů a/nebo lamel ve zdivu
CZ308304B6 (cs) * 2018-11-02 2020-04-29 ÄŚeskĂ© vysokĂ© uÄŤenĂ­ technickĂ© v Praze Přípravek pro spřažení základových konstrukcí staveb

Also Published As

Publication number Publication date
CH693616A5 (de) 2003-11-14

Similar Documents

Publication Publication Date Title
WO1993020296A1 (fr) Procede et dispositif de renforcement de la resistance au cisaillement d'une partie d'un ouvrage
CH706630B1 (de) Verfahren zum Vorspannen eines Stahlbauwerkes sowie damit vorgespanntes Stahlbauwerk.
EP2817465B1 (fr) Dispositif d'introduction de force dans des éléments de traction à partir de lamelles de bandes plates en matière synthétique renforcées en fibres
EP0435820A1 (fr) Procédé pour le renforcement d'éléments de construction
WO2012022783A1 (fr) Dispositif d'induction de force dans des éléments de traction constitués de lamelles plates en matière plastique renforcée par des fibres
EP0596219B1 (fr) Procédé de jonction d'éxtremités de convoies transporteurs et élément de jonction correspondant
WO2001020097A1 (fr) Systeme d'ancrage recevant les forces de traction de tirants renforces de fibres de carbone
EP2489808A1 (fr) Elément d'armature pour la réception de forces dans des éléments en béton, soutenus par des éléments d'appui
EP1380705B1 (fr) Utilisation d'un dispositif d'ancrage pour tirants
DE102015008226A1 (de) Stahlbetonbauelement mit netzförmigem Armierungselement
DE19828835C1 (de) Zugstab zur Verwendung als Gurt für Brücken
EP1656485B1 (fr) Elément de transfert de force
AT334046B (de) Zusammenrollbares tragelement
DE2820185C3 (de) Siebforderband
DE355057C (de) Nietloses Gitterwerk
DE3737758A1 (de) Vorrichtung zur verankerung von kunststoffspanngliedern in beton
DE4425310A1 (de) Schwingungsarmer Verbundträger
DE1509023C (de) Fachwerkträger mit hölzernen Gurten
DE479118C (de) Befestigungsmittel fuer Gummigewebescheiben von elastischen Wellenkupplungen
WO2009015823A1 (fr) Dispositif de presse
DE1409137C (de) Spannghedstoß fur lagenweise zwischen Klemmpiatten gehaltene Spanndrahte
DE102021103589A1 (de) Betonbewehrungselement
DE3712514C1 (en) Device for anchoring plastic stressing members in concrete
EP1280968A1 (fr) Elements de construction stabilises par precontrainte
DE29615019U1 (de) Vorrichtung zur konzentrierten Krafteinleitung in Beton

Legal Events

Date Code Title Description
AK Designated states

Kind code of ref document: A1

Designated state(s): US

AL Designated countries for regional patents

Kind code of ref document: A1

Designated state(s): AT BE CH CY DE DK ES FI FR GB GR IE IT LU MC NL PT SE

121 Ep: the epo has been informed by wipo that ep was designated in this application
DFPE Request for preliminary examination filed prior to expiration of 19th month from priority date (pct application filed before 20040101)
122 Ep: pct application non-entry in european phase