US3701554A - Reinforcing and prestressing cable - Google Patents

Reinforcing and prestressing cable Download PDF

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Publication number
US3701554A
US3701554A US878856A US3701554DA US3701554A US 3701554 A US3701554 A US 3701554A US 878856 A US878856 A US 878856A US 3701554D A US3701554D A US 3701554DA US 3701554 A US3701554 A US 3701554A
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United States
Prior art keywords
strips
cable
extremities
interleaved
cable portion
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Legal status (The legal status 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 status listed.)
Expired - Lifetime
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US878856A
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English (en)
Inventor
Andre Puyo
Pierre Andre Habib
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Tractebel Engineering SA
Original Assignee
Coyne et Bellier Bureau dIngenieurs Conseils SA
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Expired - Lifetime legal-status Critical Current

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    • 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
    • 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
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T403/00—Joints and connections
    • Y10T403/70—Interfitted members
    • Y10T403/7062—Clamped members

Definitions

  • ABSIMCT A tension cable essentially composed of a multiplicity of thin strips is clamped at one or more locations with [30] Fm'gn Appliumon Pnomy Data freedom of slight relative slippage of the strips to Nov. 26, 1968 France ..68175335 equalize their stresses. At each clamping point the strips may be separated by interposed foils which may 1.8. CI.
  • a related object is to provide simple means for anchoring such a cable to a structure.
  • a more particular object is to provide a novel cable construction, essentially composed of a multiplicity of coextensive elements of low individual tensile strength, wherein means are provided for effectively distributing the loading stresses so as to avoid any local overstressing.
  • a tension cable consists essentially of a multiplicity of juxtaposed parallel strips or ribbons of flexible character, e.g. metallic or resinous, which are of substantially the same length and preferably but not necessarily the same width, these strips being clamped together at one or more locations so as to be longitudinally shiftable only to the extent permitted by their elastic deformability.
  • These strips each of which may have a thickness of as little as 0.1 mm, thus form a stack which in most instances will be of square or rectangular profile and which therefore can be easily guided in a similarly profiled channel of an associated structure.
  • the cable surface and/or the channel walls may be coated or lined with a low-friction material such as polytetrafluoroethylene (Teflon).
  • portions of the cable near a clamped extremity thereof may also be passed around curved high-friction guide surfaces having a secondary restraining effect.
  • guide surfaces may be formed, for example, by a cylindrically curved anchor block embraced by the cable; alternatively, they can be constituted by the walls of an undulating or meandering channel.
  • the strips are separated at the clamping point or points by interposed foils or leaves of like or different material preferably having the same order of thickness; these interposed foils may be the strips of a similar cable spliced to or intersecting the first cable, or the opposite above.
  • FIG. 1 is a cross-sectional view of a cable according to the invention, taken on the line I I of FIG. 2 and showing a clamping stage;
  • FIG. 2 is a cross-sectional view taken on the line II II of FIG. 1;
  • FIG. 3 is a perspective view of an assembly similar to that shown in FIGS. 1 and 2;
  • FIGS. 4 and 5 are graphs illustrating the longitudinal stress distribution in a cable according to the invention.
  • FIG. 6 is a cross-sectional view of a multiple clamp for a cable according to the invention, taken on the line VI VI of FIG. 7;
  • FIG. 7 is a cross-sectional view taken on the line VII VII of FIG. 6;
  • FIG. 8 is a perspective view of an assembly similar to that shown in FIGS. 6 and 7;
  • FIG. 9 is an elevational view of a cable terminal according to our invention.
  • FIG. 10 is a cross-sectional view taken on the line X X of FIG. 9;
  • FIG. 1 l is a view similar to FIG. 9, illustrating a modification
  • FIG. 12 is another view similar to FIG. 9, illustrating a further cable terminal embodying the invention.
  • FIG. 13 is a cross-sectional view taken on the line XIII XIII of FIG. 12;
  • FIG. 14 is a cross-sectional view of a modified cable which are shown to be of the same order of thickness as the strips, may consist of similar or dissimilar material and, in particular, could be the ends of like strips forming part of a substantially identical cable.
  • the strips 1 and the foils 2 are joined together under transverse pressure in a clamping device comprising a rectangular frame 3, a pair of plates 4 slidably held in the frame to serve as clamp jaws and several pairs of complementary wedges 5, 6 inserted between the plates 4 and the frame 3.
  • the wedges 5, 6 have the profile of right triangles slidably contacting each other along their hypotenuse, the angle of inclination of their contact surfaces being, of course, less than their angle of friction.
  • Foils 2 could also be blade-like projections of a common terminal member, not further illustrated, to be secured to the cable by the clamp 3 6.
  • FIG. 3 I have shown the strips 1 separated by foils 7 extending transversely to the strips and projecting laterally therefrom.
  • the projecting foil portions are interleaved with coextensive spacers or pads 8 which may or may not be of the same material and which have substantially the same thickness as the strips coplanar therewith.
  • the rectangular stack formed by the elements 7, 8 andby the interleaved portions of strips 1 is received in a four-sided box 9 having a bottom 10 with a rectangular cutout; after the box has been slid upwardly (arrow A) to receive the stack, pressure is exerted on the outermost strips la in the direction of arrow Band C by clamping means which may, take the form of distributing platesand wedge pieces similar to the elements 4 6 of FIGS.
  • the wedges 5, 6 may be separated from the stack 1, 7, 8 by a pair of distributing plates 11, similar to plates 4 in FIGS. 1 and 2, as well as a pair of elastic inserts 12 juxtaposed therewith.
  • the inserts 12 may be, for example, undulating steel plates with vertical crests and troughs as viewed in FIG. 7; they could also be constituted by pads of rubber or other elastomeric material.
  • the tensile stress T required to cause slippage of the strip is equal to 2fN where f is the coefficient of friction.
  • the strip does experience a certain elongation between its clamp jaws whereby the tension applied to it on one side of the clamping point generates a progressively decreasing stress over the length of the clamped strip portion.
  • tension T has been plotted against length L.
  • the stress rises substantially linearly from 0 to a maximum T which corresponds to the applied tension.
  • the rising stress over the length L is proportional to'the slip between any elemental area of the strip and the stationary clamping surfaces.
  • the tensile stress T first rises from 0 to a relatively low value T, over a length L, clamped at a location remote from the origin of tension; the stress then remains constant up to the second clamping area of length L where it rises to another intermediate value T At a third clamping station of effective length L the tensile stress reaches its final magnitude T It will be noted that the slopes of the graph of FIG. 5 are considerably lower than those of the graph of FIG. 4.
  • FIG. 6 illustrates a relatively compact assembly for stressing a cable according to the invention in the aforedescribed manner by four clamping stages. These stages are constituted by four boxes 13a, 13b, 13c, 13d each forming part of a clamping assembly of the type described above with reference to FIG. 7.
  • the frame portions 9 of the several boxes abut one another while their bottoms 10 are freely penetrated by the cable, the passages through these bottoms constituting the regions of constant stress shown in FIG. 5. If the cable formed by the strips 1 is to be tensioned from the left as indicated by the arrow T in FIG. 6, it will be convenient to clamp first the box 13a in position thereon, followed by the boxes 13b, 13c and 13d.
  • the box 13d may be placed indirect contact with such structure to anchor the cable to it and to hold the clamping assembly in position-The number of boxes may, of course, be increased or reduced at will.
  • F IG. 8 we have shown another assembly which can be substituted, with similar effect, for the set of juxtaposed boxes shown in FIG. 6.
  • the clamping device of- FIG. 8 comprises a casing 15 with two sidewalls 15' formed along their confronting surfaces with transverse ribs 16. The recesses between these ribs accommodate the ends of foils 7, similar to those shown in FIGS. 3 and 7, together with the spacers 8 (not seen in FIG. 8) interleaved therewith.
  • the sidewalls 15' may be interconnected at the bottom of the casing, although the latter could also be open at both ends; the longitudinal edges of these sidewalls are formed with threaded bores 17 designed to receive bolts 19 which pass through corresponding holes in a series of alternately wider and narrower brackets 18, 20.
  • the bolts 19 passing through brackets 18 are engaged by nuts 19' holding these brackets under pressure against the stack of elements 1, 7, 8 within the casing; this pressure may be initially generated by the nuts themselves or may have been applied by a jack or the like, subsequently removed, with the nuts serving only as retaining elements.
  • the brackets 18, 20 are U-shaped and embrace the housing walls 15' by their arms 18a, 20a.
  • brackets 16 serve only to form a rigid connection between the wall members .
  • the housing wall 15" opposite brackets 18, may be rigid with sidewalls 15' or may be secured thereto by screws similar to bolts 19 and nuts 19; in either case, this wall 15" constitutes a second clamp jaw cooperating with the jaws 18 of the several juxtaposed clamping assemblies.
  • this wall could also be subdivided into individual brackets 18, 20 to help select the optimum clamping pressure for each stage.
  • resilient means may again be provided for elastically applying the clamp jaws against the cable strips.
  • compression springs such as Belleville washers 19" between the nuts 19 and the brackets 18 so that, with the bolts 19 effectively connected to the remote jaw 15'', the two jaws are elastically biases toward each other.
  • FIGS. 9 and 10 illustrate the distribution of the stresses of several clamping stages over a curved surface whose frictional engagement with the cable affords a still more gradual transition between points of maximum and minimum stress.
  • a terminal member or head 22 has a generally cylindrically convex peripheral surface embraced from one side by one set of strips 1A and from the other side by another set of strips 18 whose ends are interleaved with those of strips lA over a substantial part of that curved surface.
  • the several clamping stages are constituted by pairs of flat bars 24 that are pivoted to head 22 by pins 23 and carry bolts 25 traversing pressure plates 26 which are held in position by nuts 27. Elastic pads 26a are shown interposed between the plates 26 and the stack of strips 1A, 13.
  • radius of curvature of head 22 progressively increases from an apex, enveloped by both groups of strips 1A, 18, to the transverse bottom edge of the head where its periphery flattens out.
  • the two sets of strips 1A, 18 could be part of a single cable bent back upon itself.
  • the two sets of strips 1A, 1B may be combined in a channel 29 of an extension 28 of a modified head 22a, this channel being flared so as to converge in a direction away from head 220.
  • the head 22a is curved over an arc substantially greater than 180 and is studded over substantially its entire periphery by clamping stages 23 27 as described above.
  • Member 28 may be a block integral with or otherwise secured to head 22a.
  • the strips 1 of a cable according to our invention may be split into two groups hugging opposite walls of an undulating channel 32 formed in a block 30. These walls are of sinusoidal shape and form constrictions 36, 37, 38 separated by wider passages accommodating cylindrical inserts 33, between the two cable halves.
  • Block 30 may consist of several laminations or sections held together by transverse bolts 31.
  • a pair of clamp jaws co-operate with an interposed wedge 39 to engage the free ends of the two cable halves; jaws 40 may be cemented or otherwise secured to the block and are shown externally reinforced by a fiat coil 41 of metal or the like encased in a ellipsoidal shell 42.
  • the insert 35 proximal to the clamp 39, 40 is fixedly mounted between the lateral walls 34 of channel 32 whereas the more remote insert 33 is freely movable between these walls, thereby allowing greater freedom of slippage to the cable portions engaged by it.
  • the two strip assemblies alternatively curve about the bends of the channel walls and the in-' serts, contacting them along arcs a, B, I", y, and 8.
  • the total surface frictionally engaged by the cable strips equals the sum of the arcs (oz-+- +1 +'y+8)
  • the terminal members shown in FIGS. 9 12 may again be placed directly in contact with a structure against which the cable is to be stressed.
  • the width of the strips may be staggered to conform to its outline. This has been shown in FIG. 14
  • the cable constituted by the foils 101 is of generally cylindrical configuration so as to be easily guided in a round bore of corresponding diameter.
  • the profile of the cable be round or polygonal, its cross-sectional area can always be substantially fully occupied by tensionable elements for maximum tensile strength.
  • a cable junction comprising:
  • first cable portion and a second cable portion each composed essentially of a multiplicity of flat, superposed and substantially longitudinally coextensive strips, the strips of said first cable portion having extremities interleaved with extremities of the strips of said second cable portion in direct broadsurface contact throughout a predetermined zone of overlap;
  • a cable junction comprising:
  • first cable portion and a second cable portion each composed essentially of a multiplicity of flat, superposed and substantially longitudinally coextensive strips, the strips of said first cable portion having extremities interleaved with extremities of the strips of said second cable portion in direct broadsurface contact throughout a predetermined zone of overlap;
  • clamping means comprising a pair of jaws and at least one elastic insert between said jaws and said strips.
  • a cable junction comprising:
  • a cable junction comprising:
  • first cable portion and a second cable portion each composed essentially of a multiplicity of flat, su-
  • clamping means bearing upon said interleaved extremities under transverse pressure over part of said zone, said strips being engaged by said clamping means with freedom of slight relative slippage, said clamping means comprising a plurality of clamps engaging said strips at longitudinally spaced locations and a body with a curved guide surface in frictional engagement with an outermost one of said strips at a plurality of locations over a length of cable hugging said surface.

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  • Engineering & Computer Science (AREA)
  • Architecture (AREA)
  • Civil Engineering (AREA)
  • Structural Engineering (AREA)
  • Ropes Or Cables (AREA)
  • Laying Of Electric Cables Or Lines Outside (AREA)
US878856A 1968-11-26 1969-11-21 Reinforcing and prestressing cable Expired - Lifetime US3701554A (en)

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FR175335 1968-11-26

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DE (1) DE1958882A1 (pm)
FR (1) FR1593397A (pm)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2001020097A1 (de) * 1999-09-15 2001-03-22 Eidgenössische Materialprüfungs- und Forschungsanstalt Empa Verankerungssystem zur aufnahme der zugkräfte von kohlefaserverstärkten zugbändern (cfk-bändern)
DE10060459A1 (de) * 2000-09-21 2002-04-11 Gert Koenig Spannverankerung und Koppelung für Stahl- und Faserlamellen
ITRM20100410A1 (it) * 2010-07-23 2012-01-24 Fabio Brancaleoni Funi con struttura costituita da affiancamento e/o composizione di nastri.
US20130160394A1 (en) * 2010-08-18 2013-06-27 Sika Technology Ag Device for introducing a force into tension members made of fiber-reinforced plastic flat strip lamellas

Families Citing this family (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE2250924C3 (de) * 1972-10-18 1975-08-14 Schiess Ag Kletterhubwerk zum Anheben oder Absenken großer Lasten
DE2512114A1 (de) * 1975-03-19 1976-09-30 Intercontinentale Technik Gmbh Endverankerung fuer spannelemente
DE2547005C3 (de) * 1975-10-21 1978-08-03 Robert Bosch Gmbh, 7000 Stuttgart Mengenmesser
DE2932809C2 (de) * 1979-08-13 1995-11-23 Rehm Gallus Vorrichtung zur Endverankerung mindestens eines Spannbeton-Spannstabes aus Faserverbundwerkstoff
EP0025856B1 (de) * 1979-08-13 1984-07-25 RESTRA-Patentverwertung GmbH Vorrichtung zur Endverankerung mindestens eines als Spannglied im Spannbetonbau eingesetzten Stabes aus Faser-Verbundstoff
ATE47612T1 (de) 1980-08-13 1989-11-15 Restra Patentverwertung Gmbh Vorrichtung zur endverankerung mindestens eines als spannglied im spannbetonbau eingesetzten stabes aus faser-verbundwerkstoff.
FR2590608B1 (fr) * 1985-11-26 1989-05-05 Freyssinet Int Stup Perfectionnements aux dispositifs de precontrainte ou analogues comportant des tirants.

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2737802A (en) * 1949-10-25 1956-03-13 Bakker Johannes Composite prestressing reinforcement
US2941394A (en) * 1955-04-22 1960-06-21 Fred H Brandt Reinforcing and tensioning members for concrete structures
US3099109A (en) * 1958-03-01 1963-07-30 Zueblin Ag Device for anchoring tensioning elements
US3249374A (en) * 1959-06-18 1966-05-03 Holzmann Philipp Ag Apparatus for coupling together two bundles of stressing wires for stressing concrete
US3379463A (en) * 1965-10-22 1968-04-23 Clifton W. Marshall Bearing mechanism for load supporting multiple ply cables

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2737802A (en) * 1949-10-25 1956-03-13 Bakker Johannes Composite prestressing reinforcement
US2941394A (en) * 1955-04-22 1960-06-21 Fred H Brandt Reinforcing and tensioning members for concrete structures
US3099109A (en) * 1958-03-01 1963-07-30 Zueblin Ag Device for anchoring tensioning elements
US3249374A (en) * 1959-06-18 1966-05-03 Holzmann Philipp Ag Apparatus for coupling together two bundles of stressing wires for stressing concrete
US3379463A (en) * 1965-10-22 1968-04-23 Clifton W. Marshall Bearing mechanism for load supporting multiple ply cables

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2001020097A1 (de) * 1999-09-15 2001-03-22 Eidgenössische Materialprüfungs- und Forschungsanstalt Empa Verankerungssystem zur aufnahme der zugkräfte von kohlefaserverstärkten zugbändern (cfk-bändern)
DE10060459A1 (de) * 2000-09-21 2002-04-11 Gert Koenig Spannverankerung und Koppelung für Stahl- und Faserlamellen
ITRM20100410A1 (it) * 2010-07-23 2012-01-24 Fabio Brancaleoni Funi con struttura costituita da affiancamento e/o composizione di nastri.
WO2012011143A1 (en) * 2010-07-23 2012-01-26 Fabio Brancaleoni Ropes having a structure constitued by placing side-by-side and/or by composing a plurality of bands
US20130160394A1 (en) * 2010-08-18 2013-06-27 Sika Technology Ag Device for introducing a force into tension members made of fiber-reinforced plastic flat strip lamellas
US9663963B2 (en) * 2010-08-18 2017-05-30 Sika Technology Ag Device for introducing a force into tension members made of fiber-reinforced plastic flat strip lamellas

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Publication number Publication date
FR1593397A (pm) 1970-05-25
DE1958882A1 (de) 1970-06-18

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