Cross-Reference to Related Applications
Technical Field/Field of the Disclosure
[0002] The present disclosure relates generally to post-tensioned, pre-stressed concrete
construction. The present disclosure relates specifically to anchors for use therein.
Background of the Disclosure
[0003] Many structures are built using concrete, including, for instance, buildings, parking
structures, apartments, condominiums, hotels, mixed-use structures, casinos, hospitals,
medical buildings, government buildings, research/academic institutions, industrial
buildings, malls, roads, bridges, pavement, tanks, reservoirs, silos, sports courts,
and other structures.
[0004] Prestressed concrete is structural concrete in which internal stresses are introduced
to reduce potential tensile stresses in the concrete resulting from applied loads;
prestressing may be accomplished by post-tensioned prestressing or pre-tensioned prestressing.
In post-tensioned prestressing, a tension member is tensioned after the concrete has
attained a desired strength by use of a post-tensioning tendon. The post-tensioning
tendon may include for example and without limitation, anchor assemblies, the tension
member, and sheathes. Traditionally, a tension member is constructed of a material
that can be elongated and may be a single or a multi-strand cable. Typically, the
tension member may be formed from a metal or composite material, such as reinforced
steel. The post-tensioning tendon conventionally includes an anchor assembly at each
end. The post-tensioning tendon is fixedly coupled to a fixed anchor assembly positioned
at one end of the post-tensioning tendon, the "fixed-end", and stressed at the stressed
anchor assembly positioned at the opposite end of the post-tensioning tendon, the
"stressing-end" of the post-tensioning tendon.
[0005] Post-tension members are conventionally formed from a strand and a sheath. The strand
is conventionally formed as a single or multi-strand metal cable. The strand is conventionally
encapsulated within a polymeric sheath extruded thereabout to, for example, prevent
or retard corrosion of the metal strand by protecting the metal strand from exposure
to corrosive or reactive fluids. Likewise, the sheath may prevent or retard concrete
from bonding to the strand and preventing or restricting movement of the sheath during
post-tensioning. The sheath may be filled with grease to further limit the exposure
of the metal strand and allow for increased mobility. Because the metal strand and
the polymeric sheath are formed from different materials, the thermal expansion and
contraction rates of the metal strand and polymeric sheath may differ. During conventional
manufacturing, the sheaths are formed by hot extrusion over the metal strand. When
the tension members are coiled for transport and storage, uneven thermal contraction
may occur as the tendon cools. When installed as a post-tensioning tendon in a pre-stressed
concrete member, cooling of the sheath may cause separation of the sheath from an
anchorage, potentially exposing the metal strand to corrosive or reactive fluids.
Summary
[0006] The present disclosure also provides for a post-tensioning tendon. The post-tensioning
tendon includes a tension member including a strand and sheath, the sheath having
an outer surface. The post-tensioning tendon also includes an anchor coupled to an
end of the tension member, the anchor including a tubular extension through which
the tension member is passed. The tubular extension has an engaging surface. The post-tensioning
tendon additionally includes a sheathing retention assembly. The sheathing retention
assembly includes an outer cap, the outer cap having a forcing surface. The outer
cap is coupled to the tubular extension. The sheathing retention assembly also includes
one or more holding elements positioned at least partially within the outer cap. The
one or more holding elements each have a tapered outer surface abutting the forcing
surface. The one or more holding elements each includes an inner surface that engages
the outer surface of the sheath.
[0007] The present disclosure also provides for a method of coupling a tension member to
an anchor for forming a post-tensioning tendon. The method includes providing the
tension member, the tension member including a strand and a sheath. The sheath has
an outer surface. The method also includes providing the anchor, the anchor including
a tubular extension and positioning a sheathing retention assembly about an end of
the tension member. The sheathing retention assembly includes an outer cap, the outer
cap having a forcing surface and one or more holding elements positioned at least
partially within the outer cap. The one or more holding elements each have a tapered
outer surface abutting the forcing surface. The one or more holding elements each
include an inner surface that engages the outer surface of the sheath. The method
also includes passing the end of the tension member through the tubular extension
of the anchor and coupling the outer cap to the tubular extension.
[0008] The present disclosure additionally provides for a method of coupling a tension member
to an anchor for forming a post-tensioning tendon. The method includes providing the
tension member, the tension member including a strand and a sheath, and providing
the anchor. The method also includes positioning an outer cap about a tubular extension
in a non-actuated position, the outer cap having a forcing surface. Further, the method
includes coupling the outer cap to the tubular extension, thereby moving the outer
cap to an actuated position and positioning one or more holding elements at least
partially within the outer cap. The one or more holding elements each have a tapered
outer surface abutting the forcing surface. The one or more holding elements each
include an inner surface that engages the outer surface of the sheath. The method
also includes passing the end of the tension member through the tubular extension
of the anchor and coupling the outer cap to the tubular extension.
[0009] The present disclosure provides for a post-tensioning tendon. The post-tensioning
tendon includes a tension member including a strand and sheath, the sheath having
an outer surface. The tension member also includes an anchor coupled to an end of
the tension member. The anchor includes a tubular extension through which the tension
member is passed. The tubular extension has an engaging surface. The post-tensioning
tendon also includes a sheathing retention assembly. The sheathing retention assembly
includes an outer cap, the outer cap having a forcing surface. The outer cap is coupled
to the tubular extension. The sheathing retention assembly also includes one or more
holding elements positioned at least partially within the outer cap, the one or more
holding elements each having an outer surface abutting the forcing surface. The outer
surface of the one or more holding elements is not tapered. The one or more holding
elements each includes an inner surface that engages the outer surface of the sheath.
Brief Description of the Drawings
[0010] The present disclosure is best understood from the following detailed description
when read with the accompanying figures. It is emphasized that, in accordance with
the standard practice in the industry, various features are not drawn to scale. In
fact, the dimensions of the various features may be arbitrarily increased or reduced
for clarity of discussion.
FIGS. 1A, 1B depict a partial cross section of a post-tensioning tendon within a concrete
form during stages of a concrete pouring procedure consistent with embodiments of
the present disclosure.
FIG. 2A depicts a cross section view of a stressing end anchor for a post tensioned
concrete member including a sheathing retention assembly consistent with at least
one embodiment of the present disclosure.
FIG. 2B depicts a cross section view of a fixed end anchor for a post tensioned concrete
member including a sheathing retention assembly consistent with at least one embodiment
of the present disclosure.
FIG. 3 depicts a cross section of a sheathing retention assembly consistent with at
least one embodiment of the present disclosure.
FIGS. 4A, 4B depict a wedge for use in a sheathing retention assembly consistent with
at least one embodiment of the present disclosure.
FIG. 5A depicts a partial cross section of an anchor for a post tensioned concrete
member including a sheathing retention assembly consistent with at least one embodiment
of the present disclosure.
FIG. 5B is a partial transparent view of the anchor of FIG. 5A.
FIG. 6 depicts a wedge for use in a sheathing retention assembly consistent with at
least one embodiment of the present disclosure.
Detailed Description
[0011] It is to be understood that the following disclosure provides many different embodiments,
or examples, for implementing different features of various embodiments. Specific
examples of components and arrangements are described below to simplify the present
disclosure. These are, of course, merely examples and are not intended to be limiting.
In addition, the present disclosure may repeat reference numerals and/or letters in
the various examples. This repetition is for the purpose of simplicity and clarity
and does not in itself dictate a relationship between the various embodiments and/or
configurations discussed.
[0012] When stressing concrete member 40, anchoring systems may be provided to hold the
tension member before and after stressing. In some embodiments, as depicted in FIGS.
1A, 1B, post-tensioning tendon 11 may be positioned within concrete form 21. Concrete
form 21 is a form into which concrete may be poured to form concrete member 40. Post-tensioning
tendon 11 may include for example and without limitation fixed end anchor 13, tension
member 15, and stressing end anchor 17. As depicted in FIG. 1A, in some embodiments,
fixed end anchor 13 may include fixed end anchor body 14. Fixed-end anchor body 14
may be positioned within concrete form 21 such that fixed-end anchor body 14 will
be encased in concrete 23 after concrete is poured into concrete form 21. In some
embodiments, fixed end cap 19 may be positioned at distal end 41 of fixed end anchor
body 14. Fixed end cap 19 may, in certain embodiments, protect tension member 15 from
corrosion after concrete 23 is poured by preventing or retarding corrosive or reactive
fluids or concrete from contacting tension member 15.
[0013] Stressing end anchor 17 may be positioned within concrete form 21 such that it is
substantially surrounded by concrete 23. Pocket former 25 may be positioned between
stressing end anchor body 18 and end wall 22 of concrete form 21. Pocket former 25
may be adapted to, for example and without limitation, prevent or restrict concrete
23 from filling the space between stressing end anchor body 18 and end wall 22, thus
forming a cavity or pocket in edge 42 of concrete member 40 formed by concrete 23
within concrete form 21. Pocket former 25 may thus allow access to tension member
15 from outside concrete member 40 once concrete member 40 is sufficiently hardened
and end wall 22 is removed.
[0014] In some embodiments, tension member 15 may include strand 27 and sheath 29. Strand
27 may be a single or multi-strand metal cable. Sheath 29 may be tubular or generally
tubular and may be positioned about strand 27. In some embodiments, space between
strand 27 and sheath 29 may be filled or partially filled with a filler such as grease.
When installing tension member 15, in some embodiments, a length of sheath 29 may
be removed from first end 43 of tension member 15, exposing strand 27. Strand 27 may
be inserted through fixed end anchor 13 until sheath 29 engages with sheathing retention
capsule 100. Strand 27 may then be coupled to fixed end anchor 13 such as by the use
of wedges. Tension member 15 may be positioned within concrete form 21 and tension
member 15 may be cut to correspond with the length of concrete form 21. In some embodiments,
a length of sheath 29 may be removed from second end 44 of tension member 15, exposing
strand 27. Strand 27 may be inserted through stressing end anchor 17 until sheath
29 engages with sheathing retention capsule 100 within stressing end anchor 17.
[0015] In some embodiments, such as depicted in FIG. 2A, sheathing retention assembly 100
may include outer cap 101, one or more holding elements 103, and seal 119. Outer cap
101 may be tubular or generally tubular. Outer cap 101 may include a coupler for connecting
to tubular extension 14 of stressing end anchor 17 through which tension member 15
may pass. Although described with respect to stressing end anchor 17, sheathing assembly
100 may be used in conjunction with fixed end anchor 13, as shown in FIG. 2B. In some
embodiments, tubular extension 14 may be formed integrally with stressing end anchor
17. In some embodiments, tubular extension 14 may be formed separately from stressing
end anchor 17 and may be coupled thereto by, for example and without limitation, a
press fit, chemical or mechanical welding, a thread, detent, press lock, bayonet,
or tab-and-slot connection. In some embodiments, tubular extension 14 may be coupled
to outer cap 101 before tubular extension 14 is installed to stressing end anchor
17. In such an embodiment, outer cap 101 may be coupled in a non-actuated position
when tubular extension 14 is coupled to outer cap 101. In the non-actuated position,
holding elements are positioned within outer cap 101 and the wedges may slide along
sheath 29. FIG. 5 A depicts outer cap 101 in non-actuated position. Outer cap 101
may be moved into the actuated position by coupling to tubular extension 14 by a coupler,
including for example and without limitation a thread, detent, press lock, bayonet,
or tab-and-slot connection. In the actuated position, holding elements 103 may grip
sheath 29, as described herein below. FIGs. 2A, 2B depict outer cap 101 in an actuated
position. As depicted in FIG. 2A, 2B, the coupler is a tab-and-slot connection where
outer cap 101 may include one or more slots 102 that may receive one or more corresponding
tabs 104 formed on engaging surface 135 of tubular extension 14. In some embodiments,
tabs 102 may be wedge-shaped to allow installation of outer cap 101 about tubular
extension 14 while inhibiting removal of extension 14 therefrom.
[0016] In another embodiment, as shown in FIG. 5B, outer cap 301 may include outer cap bayonet
ramps 302. Outer cap bayonet ramps 302 may interconnect with corresponding tubular
extension bayonet ramps 304 formed on tubular extension 14. Outer cap 101 may couple
to tubular extension 14 through one or more intermediate components without deviating
from the scope of this disclosure. In some embodiments, as depicted in FIG. 2, outer
cap 101 may include a tapered inner surface defined herein as forcing surface 115.
[0017] One or more holding elements 103 may be positioned at least partially within outer
cap 101. Holding elements 103 may be wedge shaped. In some embodiments, holding elements
103 may include tapered surfaces that collectively form tapered outer surface 117.
Tapered outer surface 117 may abut and correspond with forcing surface 115. In other
embodiments, holding elements 103 are not tapered,
i.e., holding elements 103 have no tapered outer surface 117. Holding elements 103 may
be spaced apart within sheathing retention assembly 100 or may be placed in abutment.
Holding elements 103 may be positioned within sheathing retention assembly 100 such
that tapered outer surface 117 abuts forcing surface 115. Forcing surface 115 and
outer surface 117 of holding elements 103 may be positioned such that as outer cap
101 is installed in the actuated position onto tubular extension 14, the taper of
forcing surface 115 and the taper of the outer surface 117 of holding elements 103
may serve to bias or push holding elements 103 inward into contact with sheath 29,
thus, in some embodiments, increasing normal force between holding elements 103 and
sheath 29.
[0018] Inner surfaces 120 of holding elements 103 may collectively form inner face 109.
Inner face 109 may be continuous or discontinuous depending on the specific arrangement
of holding elements 103. Inner face 109 may have inner face diameter 122 generally
corresponding with,
i.e., approximately equal to, outer diameter 124 of sheath 29. In some embodiments, holding
elements 103 may include one or more surface features on inner face 109 that may increase
the static friction between the outer surface 126 of sheath 29 and holding elements
103. In some embodiments, the surface features may include, for example and without
limitation, teeth 111. Teeth 111 may be one or more grooves, protrusions, or ridges
that contact outer surface 126 of sheath 29 and, in some embodiments, press into outer
surface 126 of sheath 29, thus increasing the retention force between holding elements
103 and sheath 29.
[0019] In some embodiments, sheathing retention assembly 100 may also include seal 119.
Seal 119 may be positioned to seal between sheath 29 and tubular extension 14 and
may further be positioned between outer cap 101 and holding elements 103. Seal 119
may be annular or generally annular and fit into recess 128 formed between outer cap
101, tubular extension 14, and sheath 29. In some embodiments, seal 119 may be positioned
such that as outer cap 101 is installed into the actuated position onto tubular extension
14, seal 119 is compressed between tubular extension 14, sheath 29, and outer cap
101. Seal 119 may protect tension member 15 from corrosion after concrete 23 (shown
in FIG. 1B) is poured, such as by inhibiting fluid ingress into the interior of sheath
29. Additionally, seal 119 may inhibit concrete 23 from entering tension member 15.
In some embodiments, seal 119 may form a press fit with outer cap 101. In some such
embodiments, seal 119 may retain holding elements 103 within outer cap 101 prior to
installation thereof.
[0020] In some embodiments, as depicted in FIG. 3, holding element 203 of sheathing retention
assembly 200 may be positioned about only a portion of sheath 29. In some such embodiments,
holding element 203 may be a single wedge 206. Wedge 206 may press against sheath
29 when compressed. In some embodiments, outer body 201 may include holding surface
202 positioned in opposition to wedge 206 to provide an opposing force on sheath 29
as wedge 206 engages sheath 29.
[0021] In some embodiments, one or more holding elements 103 may be formed as one or more
wedges 106 as depicted in FIG. 4A. At least one wedge 106 may be arcuate. In some
embodiments, wedges 106 may include partial split 108 to allow wedge 106 to flex as
depicted in FIG. 4B when compressed. Partial split 108 may extend from first end 140
of wedge 106 but not to second end 142 of wedge 106. This flexure may allow for deformation
of wedge 106, and increased contact of wedge 106 with sheath 29. In some embodiments,
the inner diameter of wedge 106 may be less than outer diameter 124 of sheath 29 to
allow for a friction fit or press fit. The inner diameter of wedge 106 is the inner
diameter of wedge 106 were it to extend circumferentially. Split 108 may allow deformation
of wedge 106 to allow the inner diameter of wedge 106 thereof to more closely match
outer diameter 124 of sheath 29.
[0022] In some embodiments, as depicted in FIGS. 5A, 5B, sheathing retention assembly 300
may further include spacing collet 321. Spacing collet 321 may be positioned at least
partially within outer cap 301. Spacing collet 321 may be tubular or generally tubular
and may form a friction fit with the outer surface 126 of sheath 29. Spacing collet
321 may be positioned to fit within flanges 323 formed on holding elements 303. Spacing
collet 321 may thus retain holding elements 303 in an open position while sheath 29
is installed into sheathing retention assembly 300, allowing sheath 29 to more easily
move through holding elements 303 until outer cap 301 is installed to tubular extension
14. When outer cap 301 is installed to tubular extension 14, the movement of outer
cap 301 may cause holding elements 303 to move such that front flanges 323 move past
spacing collet 321, allowing holding elements 303 to extend inward and grip sheath
29. Additionally, the movement of holding elements 303 may compress seal 319 against
tubular extension 14. In some embodiments, seal 319 may include spacing flange 325
adapted to fit into end flanges 327 formed on holding elements 303. Seal 319 may thus
retain holding elements 303 in an open position until outer cap 301 is installed to
tubular extension 14. Furthermore, inward movement of holding elements 303 may cause
spacing flange 325 to contact outer surface 126 of sheath 29.
[0023] In some embodiments, as depicted in FIG. 6, holding element 303 may be formed from
a plurality of pieces. In some embodiments, holding element 303 may include wedged
piece 306 and die face piece 308. Wedged piece 306 may have tapered outer surface
310 and flat inner surface 312, where outer surface 314 of die face piece 308 may
be flat. In some embodiments, wedged piece 306 may be bonded to die face 308.
[0024] In operation, sheath retention assembly 100 may be coupled to fixed end anchor 13
before fixed end anchor 13 is positioned within concrete form 21 as depicted in FIG.
1A when tension member 15 is preinstalled into fixed end anchor 13. A second sheath
retention assembly 100 may be positioned about tension member 15 before tension member
15 is passed through stressing end anchor 17. Tension member 15 may be passed through
stressing end anchor 17. Outer cap 101 may be coupled to tubular extension 14 of stressing
end anchor 17, causing holding elements 103 to engage outer surface 126 of sheath
29, retaining sheath 29 to stressing end anchor 17. In some embodiments, if included,
seal 119 may also seal between at least outer surface 126 of sheath 29 and tubular
extension 14. Contraction of sheath 29 may allow holding elements 103 to engage forcing
surface 115, increasing the normal force between holding elements 103 and sheath 29,
thus increasing the friction therebetween.
[0025] One having ordinary skill in the art with the benefit of this disclosure will understand
that although described specifically with respect to fixed end anchor 13 and stressing
end anchor 17, sheathing retention assembly 100 may be utilized with any anchor for
a post-tensioned concrete member including a fixed end anchor or stressing end anchor.
Furthermore, sheathing retention assembly 100 may be used with an intermediate anchor
as understood in the art.
[0026] The foregoing outlines features of several embodiments so that a person of ordinary
skill in the art may better understand the aspects of the present disclosure. Such
features may be replaced by any one of numerous equivalent alternatives, only some
of which are disclosed herein. One of ordinary skill in the art should appreciate
that they may readily use the present disclosure as a basis for designing or modifying
other processes and structures for carrying out the same purposes and/or achieving
the same advantages of the embodiments introduced herein. One of ordinary skill in
the art should also realize that such equivalent constructions do not depart from
the spirit and scope of the present disclosure and that they may make various changes,
substitutions, and alterations herein without departing from the spirit and scope
of the present disclosure. Unless explicitly stated otherwise, nothing herein is intended
to be a definition of any word or term as generally used by a person of ordinary skill
in the art, and nothing herein is a disavowal of any scope of any word or term as
generally used by a person of ordinary skill in the art.
[0027] The present invention will now be described with reference to the following clauses:
- 1. A post-tensioning tendon comprising:
a tension member including a strand and a sheath, the sheath having an outer surface;
an anchor coupled to an end of the tension member, the anchor including a tubular
extension through which the tension member is passed; and
a sheathing retention assembly including:
an outer cap, the outer cap having a forcing surface, the outer cap coupled to the
tubular extension; and
one or more holding elements positioned at least partially within the outer cap, the
one or more holding elements each having a tapered outer surface abutting the forcing
surface, the one or more holding elements each including an inner surface that engages
the outer surface of the sheath.
- 2. The sheathing retention assembly of clause 1 having a plurality of holding elements,
wherein the inner surfaces of the plurality of holding elements forms an inner face.
- 3. The sheathing retention assembly of clause 2, wherein the inner face has teeth,
wherein the teeth of the inner face contact the outer surface of the sheath.
- 4. The sheathing retention assembly of any one of clauses 1 to 3, wherein the outer
cap couples to the tubular extension by a coupler selected from the group consisting
of a threaded, detent, press lock, bayonet, or tab-and-slot coupler.
- 5. The sheathing retention assembly of clause 4, wherein the tubular extension has
an engaging surface, and wherein the coupler is a tab-and-slot coupler, wherein the
tab-and-slot coupler comprises:
one or more slots formed in the outer cap; and
one or more tabs formed on an engaging surface of the tubular extension, wherein the
one or more slots receive the one or more tabs.
- 6. The sheathing retention assembly of clause 4, wherein the coupler is a bayonet
coupler, wherein the bayonet coupler comprises:
one or more outer cap bayonet ramps positioned on the outer cap; and
one or more tubular extension ramps positioned on the tubular extension, wherein the
outer cap bayonet ramps interconnect with the one or more tubular extension bayonet
ramps.
- 7. The sheathing retention assembly of any one of clauses 1 to 6, further comprising
a seal, the seal positioned within the outer cap, the seal further positioned between
the outer surface of the sheath and the tubular extension.
- 8. The sheathing retention assembly of any one of clauses 1 to 7, wherein the one
or more holding elements are arcuate wedges.
- 9. The sheathing retention assembly of any one of clauses 1 to 8, wherein the arcuate
wedges include a partial split.
- 10. The sheathing retention assembly of any one of clauses 1 to 9, wherein each of
the one or more holding elements further comprises a flange, wherein the sheathing
retention assembly further comprises a spacing collet, the spacing collet positioned
within the outer cap and positioned to fit within the flanges of the one or more holding
elements.
- 11. The sheathing retention assembly of any one of clauses 1 to 10, where at least
one of the one or more holding members is a wedge, the at least one holding member
including a wedged piece and a die face piece, the wedged piece having a tapered outer
surface and a flat inner surface, the die face piece having a flat outer portion,
the wedged piece and the die piece bonded.
- 12. A method of coupling a tension member to an anchor for forming a post-tensioning
tendon comprising:
providing the tension member, the tension member including a strand and a sheath,
the sheath having an outer surface;
providing the anchor, the anchor including a tubular extension;
positioning a sheathing retention assembly about an end of the tension member, the
sheathing retention assembly including:
an outer cap, the outer cap having a forcing surface; and
one or more holding elements positioned at least partially within the outer cap, the
one or more holding elements each having a tapered outer surface abutting the forcing
surface, the one or more holding elements each including an inner surface that engages
the outer surface of the sheath;
passing the end of the tension member through the tubular extension of the anchor;
and
coupling the outer cap to the tubular extension.
- 13. The method of clause 12, further comprising:
applying a tensile force to the sheath, thereby engaging the one or more holding element
with the forcing surface.
- 14. The method of clause 12 or clause 13, further comprising positioning a seal within
the outer cap and further positioning the seal between the outer surface of the sheath
and the tubular extension.
- 15. The method of any one of clauses 12 to 14, wherein the sheathing retention assembly
comprises a single holding element and wherein the single holding element is a single
wedge, the method further comprising:
positioning the one wedge about only a portion of the sheath;
positioning a holding surface in opposition to the one wedge; and
compressing the wedge against the sheath.
- 16. The method of any one of clauses 12 to 15, wherein each of the one or more holding
members is a wedge, and wherein each wedge comprises a partial split, the method further
comprising:
compressing the one or more wedges to flex the one or more wedges, thereby increasing
contact between the wedge and the sheath.
- 17. The method of any one of clauses 12 to 16 further comprising:
positioning a spacing collet at least partially within the outer cap; and
forming a friction fit between the spacing collet and the outer surface of the sheath.
- 18. A method of coupling a tension member to an anchor for forming a post-tensioning
tendon comprising:
providing the tension member, the tension member including a strand and a sheath,
the sheath having an outer surface;
providing the anchor;
positioning an outer cap about a tubular extension in a non-actuated position, the
outer cap having a forcing surface;
coupling the outer cap to the tubular extension, thereby moving the outer cap to an
actuated position;
positioning one or more holding elements at least partially within the outer cap,
the one or more holding elements each having a tapered outer surface abutting the
forcing surface, the one or more holding elements each including an inner surface
that engages the outer surface of the sheath;
passing the end of the tension member through the tubular extension; and
coupling the outer cap to the tubular extension.
- 19. A post-tensioning tendon comprising:
a tension member including a strand and sheath, the sheath having an outer surface;
an anchor coupled to an end of the tension member, the anchor including a tubular
extension through which the tension member is passed, the tubular extension having
an engaging surface; and
a sheathing retention assembly including:
an outer cap, the outer cap having a forcing surface, the outer cap coupled to the
tubular extension; and
one or more holding elements positioned at least partially within the outer cap, the
one or more holding elements each having an outer surface abutting the forcing surface
wherein the outer surface of the one or more holding elements is not tapered, the
one or more holding elements each including an inner surface that engages the outer
surface of the sheath.
- 20. The sheathing retention assembly of clause 19 having a plurality of holding elements,
wherein the inner surfaces of the plurality of holding elements forms an inner face.
- 21. The sheathing retention assembly of clause 20, wherein the inner face has teeth,
wherein the teeth of the inner face contact the outer surface of the sheath.
1. A post-tensioning tendon comprising:
a tension member including a strand and a sheath, the sheath having an outer surface;
an anchor coupled to an end of the tension member, the anchor including a tubular
extension through which the tension member is passed; and
a sheathing retention assembly including:
an outer cap, the outer cap having a forcing surface, the outer cap coupled to the
tubular extension; and
one or more holding elements positioned at least partially within the outer cap, the
one or more holding elements each having a tapered outer surface abutting the forcing
surface, the one or more holding elements each including an inner surface that engages
the outer surface of the sheath.
2. The sheathing retention assembly of claim 1 having a plurality of holding elements,
wherein the inner surfaces of the plurality of holding elements forms an inner face;
optionally, wherein the inner face has teeth, wherein the teeth of the inner face
contact the outer surface of the sheath.
3. The sheathing retention assembly of any one of claims 1 or 2, wherein the outer cap
couples to the tubular extension by a coupler selected from the group consisting of
a threaded, detent, press lock, bayonet, or tab-and-slot coupler.
4. The sheathing retention assembly of claim 3, wherein:
the tubular extension has an engaging surface, and wherein the coupler is a tab-and-slot
coupler, wherein the tab-and-slot coupler comprises:
one or more slots formed in the outer cap; and
one or more tabs formed on an engaging surface of the tubular extension, wherein the
one or more slots receive the one or more tabs; and/or,
the coupler is a bayonet coupler, wherein the bayonet coupler comprises:
one or more outer cap bayonet ramps positioned on the outer cap; and
one or more tubular extension ramps positioned on the tubular extension, wherein the
outer cap bayonet ramps interconnect with the one or more tubular extension bayonet
ramps.
5. The sheathing retention assembly of any one of claims 1 to 4, further comprising a
seal, the seal positioned within the outer cap, the seal further positioned between
the outer surface of the sheath and the tubular extension.
6. The sheathing retention assembly of any one of claims 1 to 5, wherein the one or more
holding elements are arcuate wedges.
7. The sheathing retention assembly of any one of claims 1 to 6, wherein the arcuate
wedges include a partial split.
8. The sheathing retention assembly of any one of claims 1 to 7, wherein each of the
one or more holding elements further comprises a flange, wherein the sheathing retention
assembly further comprises a spacing collet, the spacing collet positioned within
the outer cap and positioned to fit within the flanges of the one or more holding
elements.
9. The sheathing retention assembly of any one of claims 1 to 8, where at least one of
the one or more holding members is a wedge, the at least one holding member including
a wedged piece and a die face piece, the wedged piece having a tapered outer surface
and a flat inner surface, the die face piece having a flat outer portion, the wedged
piece and the die piece bonded.
10. A method of coupling a tension member to an anchor for forming a post-tensioning tendon
comprising:
providing the tension member, the tension member including a strand and a sheath,
the sheath having an outer surface;
providing the anchor, the anchor including a tubular extension;
positioning a sheathing retention assembly about an end of the tension member, the
sheathing retention assembly including:
an outer cap, the outer cap having a forcing surface; and
one or more holding elements positioned at least partially within the outer cap, the
one or more holding elements each having a tapered outer surface abutting the forcing
surface, the one or more holding elements each including an inner surface that engages
the outer surface of the sheath;
passing the end of the tension member through the tubular extension of the anchor;
and
coupling the outer cap to the tubular extension.
11. The method of claim 10 further comprising:
applying a tensile force to the sheath, thereby engaging the one or more holding element
with the forcing surface; and/or
positioning a seal within the outer cap and further positioning the seal between the
outer surface of the sheath and the tubular extension.
12. The method of claim 10 or claim 11, wherein:
the sheathing retention assembly comprises a single holding element and wherein the
single holding element is a single wedge, the method further comprising:
positioning the one wedge about only a portion of the sheath;
positioning a holding surface in opposition to the one wedge; and
compressing the wedge against the sheath; and/or,
each of the one or more holding members is a wedge, and wherein each wedge comprises
a partial split, the method further comprising:
compressing the one or more wedges to flex the one or more wedges, thereby increasing
contact between the wedge and the sheath.
13. The method of any one of claims 10 to 12 further comprising:
positioning a spacing collet at least partially within the outer cap; and
forming a friction fit between the spacing collet and the outer surface of the sheath.
14. A method of coupling a tension member to an anchor for forming a post-tensioning tendon
comprising:
providing the tension member, the tension member including a strand and a sheath,
the sheath having an outer surface;
providing the anchor;
positioning an outer cap about a tubular extension in a non-actuated position, the
outer cap having a forcing surface;
coupling the outer cap to the tubular extension, thereby moving the outer cap to an
actuated position;
positioning one or more holding elements at least partially within the outer cap,
the one or more holding elements each having a tapered outer surface abutting the
forcing surface, the one or more holding elements each including an inner surface
that engages the outer surface of the sheath;
passing the end of the tension member through the tubular extension; and
coupling the outer cap to the tubular extension.
15. A post-tensioning tendon comprising:
a tension member including a strand and sheath, the sheath having an outer surface;
an anchor coupled to an end of the tension member, the anchor including a tubular
extension through which the tension member is passed, the tubular extension having
an engaging surface; and
a sheathing retention assembly including:
an outer cap, the outer cap having a forcing surface, the outer cap coupled to the
tubular extension; and
one or more holding elements positioned at least partially within the outer cap, the
one or more holding elements each having an outer surface abutting the forcing surface
wherein the outer surface of the one or more holding elements is not tapered, the
one or more holding elements each including an inner surface that engages the outer
surface of the sheath; optionally,
having a plurality of holding elements, wherein the inner surfaces of the plurality
of holding elements forms an inner face; optionally,
wherein the inner face has teeth, wherein the teeth of the inner face contact the
outer surface of the sheath.