TECHNICAL FIELD
[0001] The present invention relates to a reinforcing bar anchorage used in reinforced concrete
structures (RC structures) and steel-reinforced concrete structures (SRC structures).
BACKGROUND ART
[0002] In RC structures and SRC structures, adhesion between reinforcing bars and concrete
is ensured by embedding a predetermined length or more of the end portions of the
reinforcing bars in the concrete, and the adhesion force along that length prevents
the reinforcing bars from being pulled out of the concrete.
[0003] The embedment of end portions of reinforcing bars in concrete for preventing the
reinforcing bars from being pulled out is called anchoring. When RC structures and
SRC structures are designed and constructed, it is important to provide anchoring
appropriate to the parts of the structures.
[0004] The anchoring of the end portions of reinforcing bars is achieved by providing an
appropriate anchorage length. However, in areas such as beam-column joints, the end
portions of reinforcing bars intersect one another in a complex manner, and these
results in overcrowding of the reinforcing bars. Hence, the bar arrangement and concrete
casting operations may not be easy to perform. In particular, when the bending moment
required for a design is large, large-diameter reinforcing bars must be employed.
With any increase in the anchorage length, the above tendency to overcrowd becomes
apparent. In addition, since reinforcing bars having a large tensile strength need
to be employed, it is difficult to bend the reinforcing bars themselves.
[0005] Therefore, a technique has been widely used in which an anchoring member is attached
to the end portions of reinforcing bars in order to solve problems during bar arrangement
or concrete casting caused by congestion of the reinforcing bars. Specifically, the
problem of preventing the pulling out of the reinforcing bars is solved not by providing
an appropriate anchorage length, but by the resistance to pulling out provided by
the attached anchoring member.
[0006] As anchoring members to be used in the above technique, various structures and various
shapes are known. For example, disk-shaped anchoring members friction-pressure-welded
to reinforcing bars, anchoring members joined to reinforcing bars through a joint
member, disk-shaped anchoring members screwed to reinforcing bars, and the like are
known.
It is referred to
JP 2004-084204 A and
JP 3763877 B.
Furthermore, from
JP 57-029763 A a reinforcing bar anchorage according to the preamble of claim 1 can be taken.
PROBLEM TO BE SOLVED BY THE INVENTION
[0007] However, in conventional methods in which an anchoring member is screwed to a reinforcing
bar or is joined to a reinforcing bar through a joint member, a problem exists in
that the reinforcing bar must be threaded. In addition to this, a problem arises in
that, when anchoring members are rotated during attachment at a worksite, the attachment
operation may not be properly completed because the anchoring members interfere with
reinforcing bars therearound. Furthermore, even when the attachment operation can
be completed, another problem exists in that workability is poor. Moreover, another
problem arises in that attachable positions for anchoring members are limited since,
in the course of screwing them on, the anchoring members contact the end portions
of the reinforcing bars.
DISCLOSURE OF THE INVENTION
[0008] The present invention has been made in view of the above circumstances, and it is
an object of the invention to provide a reinforcing bar anchorage which provides excellent
workability at a worksite and is applicable to any reinforcing bar without threading.
[0009] It is another object of the invention to provide a reinforcing bar anchorage having
an anchoring member capable of being attached at any position on a reinforcing bar.
[0010] In order to achieve the above objects, an aspect of the present invention provides
a reinforcing bar anchorage as claimed in claim 1.
[0011] In the reinforcing bar anchorage according to the aspect of the invention, the anchoring
portion may be formed as a plate-like body, and a reinforcing bar insertion opening
for allowing the reinforcing bar to pass therethrough may be formed in the plate-like
body.
[0012] Moreover, in the reinforcing bar anchorage according to the aspect of the invention,
the anchoring portion may be formed also as an annular-shaped body, and the reinforcing
bar may be allowed to pass through a space surrounded by the annular-shaped body.
[0013] Furthermore, in the reinforcing bar anchorage according to the aspect of the invention,
the connection rod may include two connection rod bodies parallel to each other, and
the sleeve may be configured to allow the reinforcing bar and the two connection rod
bodies to be inserted thereinto with the reinforcing bar sandwiched between the two
connection rod bodies. In addition to this, two pairs of the wedge insertion holes
may be provided at respective positions each of which is located between the reinforcing
bar and one of the connection rod bodies and which are substantially symmetric with
respect to an axis of the reinforcing bar.
[0014] In the reinforcing bar anchorage according to the aspect of the invention, the reinforcing
bar is anchored in concrete by the anchoring member including the anchoring portion
and the connection rod extending from the anchoring portion. In order to attach the
anchoring member to the reinforcing bar, the connection rod of the anchoring member
and the reinforcing bar are first inserted into the sleeve so as to be arranged with
the connection rod and the reinforcing bar overlapping each other by a predetermined
length. Next, the wedge member is inserted into the wedge insertion holes for press-fitting.
[0015] In this manner, the reinforcing bar is not required to be threaded, and labor involved
in threading can be omitted.
[0016] Moreover, since the anchoring member need not be rotated when being attached to the
reinforcing bar, the anchoring member is prevented from interfering with other reinforcing
bars during the attachment operation. In addition to this, since the anchoring member
can be firmly secured to the reinforcing bar simply by press-fitting the wedge member,
the workability of the bar arrangement operation at a worksite is significantly improved.
[0017] The sleeve includes: a pair of semicylindrical wall portions which are arranged such
that the curved inner surfaces thereof are opposed to each other; and a pair of flat
wall portions each extending to the corresponding edges of the respective semicylindrical
wall portions. The inner space of the sleeve includes: a reinforcing bar insertion
space on the inner side of one of the semicylindrical wall portions; and a rod insertion
space on the inner side of the other semicylindrical wall portion. The reinforcing
bar is inserted into the reinforcing bar insertion space, and the connection rod is
inserted into the rod insertion space. When the reinforcing bar and the connection
rod are inserted into the sleeve, they are arranged in parallel to each other within
the sleeve.
[0018] The wedge insertion holes are formed in the respective flat wall portions so as to
be located between the reinforcing bar and the connection rod.
[0019] When the wedge member is driven into the space between the reinforcing bar and the
connection rod, it bites into and engages both the reinforcing bar and the connection
rod by taking the reaction force from the semicylindrical wall portions of the sleeve.
[0020] As described above, a tapered portion of the wedge member bites into both the reinforcing
bar and the connection rod. Which of the reinforcing bar and the connection rod is
bitten into to a larger degree depends mainly on the difference in hardness between
the two. If the tapered portion does not sufficiently bite into the reinforcing bar,
the engaging force between the reinforcing bar and the wedge member will be insufficient.
[0021] Therefore, it is desirable that the connection rod have a hardness that is equivalent
to or higher than that of the reinforcing bar so that the wedge member can bite into
the reinforcing bar to the extent permitted by the design.
[0022] The anchoring portion may have any structure and any shape, so long as it has a desired
anchorage strength. However, if the anchoring portion is formed as a plate-like body
with a reinforcing bar insertion opening formed in it for allowing the reinforcing
bar to pass therethrough, interference between the anchoring portion and the reinforcing
bar can be prevented by the reinforcing bar insertion opening. Hence, the anchoring
member can be attached at any position on the reinforcing bar.
[0023] Also in the configuration in which the anchoring portion is formed as an annular-shaped
body and the reinforcing bar is passed through a space surrounded by the annular-shaped
body, interference between the anchoring portion and the reinforcing bar can be prevented,
as in the above case. Hence, the anchoring member can be attached at any position
on the reinforcing bar.
[0024] The connection rod can be formed from, for example, a straight steel rod having a
circular cross-section. The connection rod is not limited to being formed of a single
body. For example, the connection rod may be formed of two connection rod bodies parallel
to each other. In this case, the sleeve is configured such that the reinforcing bar
and the two connection rod bodies can be inserted thereinto with the reinforcing bar
sandwiched between the two connection rod bodies. In addition to this, two pairs of
the wedge insertion holes are provided at respective positions each of which is located
between the reinforcing bar and one of the connection rod bodies and which are substantially
symmetric with respect to the axis of the reinforcing bar.
[0025] In this configuration, not only is the anchoring member more firmly secured to the
reinforcing bar, but also the tensile force from the reinforcing bar is transmitted
to the anchoring portion without being decentered since the securing structure of
the anchoring member is symmetric with respect to the axis of the reinforcing bar.
Hence, more stable anchoring is ensured.
BRIEF DESCRIPTION OF THE DRAWINGS
[0026]
Fig. 1 is a front view of a reinforcing bar anchorage according to a first embodiment.
Figs. 2(a) and 2(b) are sectional views of the reinforcing bar anchorage, Fig. 2(a)
being a sectional view taken along line A-A, Fig. 2(b) being a sectional view taken
along line B-B.
Fig. 3 is an exploded perspective view of the reinforcing bar anchorage.
Fig. 4 is a perspective view showing a state in which the assembly of the reinforcing
bar anchorage is completed.
Fig. 5 is a diagram showing a state where the reinforcing bar anchorages according
to the first embodiment are disposed in a staggered manner.
Fig. 6 is a diagram showing a state where the reinforcing bar anchorages according
to the first embodiment are attached to respective reinforcing bars with end portions
being irregularly positioned such that the anchoring portions of the reinforcing bar
anchorages are aligned at the same height.
Figs. 7(a) and 7(b) are front views showing an anchoring member of an example and
an anchorage using the same necessary for the understanding of the invention and not
forming part of the invention.
Figs. 8(a) and 8(b) are perspective views showing an anchoring member of another modification
and an anchorage using the same, respectively.
Fig. 9 is an exploded perspective view showing a
reinforcing bar anchorage of another example necessary for the understanding of the
invention and not forming part of the invention.
Figs. 10(a) and 10(b) are front views showing reinforcing bar anchorages of other
modifications, respectively.
Fig. 11 is a front view showing a reinforcing bar anchorage of another modification.
Figs. 12(a) and 12(b) are sectional views of the modification shown in Fig. 11, Fig.
12(a) being a sectional view taken along line C-C, Fig. 12(b) being a sectional view
taken along line D-D.
Figs. 13(a) and 13(b) are diagrams showing a reinforcing bar anchorage according to
a further example necessary for the understanding of the invention not forming part
of the invention. Fig. 13(a) being a front view, Fig. 13(b) being a sectional view
taken along line E-E.
Fig. 14 is a front view showing a reinforcing bar anchorage of an example necessary
for the understanding of the invention not forming part of the invention.
Figs. 15(a) and 15(b) are front views showing reinforcing bar anchorages of other
examples, respectively, necessary for the understanding of the invention not forming
part of the invention.
Fig. 16 is a front view showing a reinforcing bar anchorage of another example necessary
for the understanding of the the invention not forming part of the invention.
Fig. 17 is a front view showing a reinforcing bar anchorage according to a yet further
example necessary for the understanding of the invention not forming part of the invention.
Figs. 18(a) and 18(b) are diagrams showing the reinforcing bar anchorage according
to the yet further example not forming part of the invention. Fig. 18(a) being a sectional
view taken along line F-F, Fig. 18(b) being a sectional view taken along line G-G.
Fig. 19 is a front view showing a reinforcing bar anchorage of an example not forming
part of the invention.
Fig. 20 is a front view showing a reinforcing bar anchorage of another modification.
Figs. 21(a) and 21(b) are sectional views of the modification shown in Fig. 20, Fig.
21(a) being a sectional view taken along line H-H, Fig. 21(b) being a sectional view
taken along line I-I.
Fig. 22 is a front view showing a reinforcing bar anchorage of another modification.
Figs. 23(a) and 23(b) are sectional views of the modification shown in Fig. 22, Fig.
23(a) being a sectional view taken along line J-J, Fig. 23(b) being a sectional view
taken along line K-K.
Fig. 24 is a front view showing a reinforcing bar anchorage of another modification.
Fig. 25 is a front view showing a reinforcing bar anchorage of another modification.
DESCRIPTION OF REFERENCE NUMERALS
[0027]
- 1, 1a, 101, 121, 161
- reinforcing bar anchorage
- 2, 102
- sleeve
- 3, 3a, 73, 103
- anchoring member
- 4
- connection rod
- 5, 5a, 105
- steel plate (plate, anchoring portion)
- 6
- wedge member
- 9
- wedge insertion hole
- 11
- reinforcing bar
- 12, 112
- reinforcing bar insertion opening
- 71
- annular-shaped body (anchoring portion)
- 104
- connection rod body
- 122
- anchoring member
- 123, 162
- anchoring member-securing rod
- 131
- flange-like protrusion
- 133, 151
- anchoring member
- 163
- anchoring member
- 164
- series connection rod
- 165
- steel plate (plate, anchoring portion)
- 166
- sleeve
- 193, 213
- anchoring member
- 194, 214
- steel plate (plate, anchoring portion)
- 195, 234
- rod insertion opening
- 224, 234
- steel plate (plate, anchoring portion)
- 225, 235
- rod insertion opening
BEST MODE FOR CARRYING OUT THE INVENTION
[0028] Hereinafter, a reinforcing bar anchorage according to preferred embodiments of the
present invention will be described with reference to the accompanying drawings. It
should be noted that components and the like substantially identical to those of conventional
technology will be designated by the same reference numerals, and a description thereof
will be omitted.
(First Embodiment)
[0029] Fig. 1 is a front view showing a reinforcing bar anchorage according to a first embodiment.
Figs. 2(a) and '2(b) are sectional views of the reinforcing bar anchorage, and Fig.
3 is an exploded perspective view of the reinforcing bar anchorage. As can be seen
from these figures, the reinforcing bar anchorage 1 in accordance with the present
embodiment includes a sleeve 2 having an ellipsoidal cross-sectional shape, an anchoring
member 3, and a wedge member 6.
[0030] The anchoring member 3 includes a substantially circular steel plate 5 as a plate-like
body and a connection rod 4 provided upright on the steel plate 5. The connection
rod 4 is formed from a straight steel rod having a circular cross-section.
[0031] The sleeve 2 is configured such that the connection rod 4 and a reinforcing bar 11
can be inserted thereinto. Specifically, when inserted, the connection rod 4 and the
reinforcing bar 11 can be arranged parallel to each other so as to overlap each other
by a predetermined length. As can be clearly seen in Fig. 2(a), the sleeve 2 is composed
of a pair of semicylindrical wall portions 7, 7 which are arranged so that the curved
inner surfaces thereof are opposed to each other; and a pair of flat wall portions
8, 8 each extending to the corresponding edges of the respective semicylindrical wall
portions 7, 7. Wedge insertion holes 9, 9 are formed in the pair of flat wall portions
8, 8, respectively, so as to be opposed to each other. The wedge insertion holes 9,
9 are aligned such that the axis line thereof is located between the reinforcing bar
11 and the connection rod 4 when these are inserted into the sleeve 2.
[0032] The wedge member 6 is designed to be inserted into the wedge insertion holes 9, 9
for press-fitting. When the wedge member 6 is press-fitted between the reinforcing
bar 11 and the connection rod 4, it bites into and engages the reinforcing bar 11
and the connection rod 4 by taking the reaction force from the semicylindrical wall
portions 7, 7 of the sleeve 2.
[0033] As described above, a tapered portion of the wedge member 6 bites into both the reinforcing
bar 11 and the connection rod 4. Which of the reinforcing bar and the connection rod
is bitten into to a larger degree depends mainly on the difference in hardness between
the two. If the tapered portion does not sufficiently bite into the reinforcing bar
11, the engaging force between the reinforcing bar 11 and the wedge member 6 will
be insufficient.
[0034] Therefore, it is desirable that the connection rod 4 have a hardness equivalent to
or higher than that of the reinforcing bar 11, so that the wedge member 6 can bite
into the reinforcing bar 11 to the extent permitted by the design.
[0035] As described above, the steel plate 5 of the anchoring member 3 is a substantially
circular plate-like body. However, in the present embodiment, the steel plate 5 has
a notch-like reinforcing bar insertion opening 12 formed therein, and the reinforcing
bar 11 can be passed through the reinforcing bar insertion opening 12.
[0036] In order to attach the reinforcing bar anchorage 1 according to the present embodiment
to the reinforcing bar 11, an end portion of the reinforcing bar 11 is first inserted
into a first opening of the sleeve 2 and allowed to pass through the sleeve 2. Then,
the connection rod 4 of the anchoring member 3 is inserted through a second opening
of the sleeve 2 and allowed to pass through the sleeve 2.
[0037] Next, the anchoring member 3 and, if necessary, the sleeve 2 are slid relative to
the reinforcing bar 11 such that the anchoring member 3, particularly the steel plate
5 thereof, is located at a desired position. At this time, since the reinforcing bar
11 is allowed to freely pass frontward and backward through the reinforcing bar insertion
opening 12 of the steel plate 5, the anchoring member 3 can be displaced to any position
relative to the reinforcing bar 11.
[0038] After completion of alignment of the anchoring member 3 as described above, the wedge
member 6 is inserted into the wedge insertion holes 9, 9 for press-fitting. Any appropriate
known wedge driver may be selected and used for press-fitting.
[0039] Fig. 4 is a diagram showing a state in which the wedge driving operation is finished
and the attachment of the anchoring member 3 to the reinforcing bar 11 is completed.
[0040] As described above, with the reinforcing bar anchorage 1 according to the present
embodiment, when the anchoring member 3 is attached to the reinforcing bar 11, the
connection rod 4 of the anchoring member 3 and the reinforcing bar 11 are inserted
into the sleeve 2 and are arranged so as to overlap each other by a predetermined
length. In this state, the wedge member 6 is inserted into the wedge insertion holes
9, 9 for press-fitting. Hence, the anchoring member 3 can be firmly joined to the
reinforcing bar 11 without machining the reinforcing bar 11. Therefore, conventionally
required labor involved in threading the reinforcing bar can be omitted. In addition,
since the anchoring member 3 can be firmly secured to the reinforcing bar 11 simply
by press-fitting the wedge member 6, the operational advantage of significantly improving
the workability of the bar arrangement operation at a worksite can be obtained.
[0041] Moreover, in the reinforcing bar anchorage 1 according to the present embodiment,
since the anchoring member 3 need not be rotated when being attached to the reinforcing
bar 11, the anchoring member 3 is prevented from interfering with other reinforcing
bars during the attachment operation. This, along with simplification of the securing
operation described above, allows a further improvement in the efficiency of the bar
arrangement operation.
[0042] Furthermore, in the reinforcing bar anchorage 1 according to the present embodiment,
interference between the steel plate 5 and the reinforcing bar 11 can be prevented
by provision of the reinforcing bar insertion opening 12 formed in the steel plate
5 serving as an anchoring portion. Hence, the anchoring member 3 can be attached at
any position on the reinforcing bar 11.
[0043] Fig. 5 shows a configuration in which the anchoring members 3 are secured in a staggered
manner to a plurality of reinforcing bars 11, respectively, arranged at a predetermined
pitch. In this configuration, interference between the anchoring members 3 can be
prevented.
[0044] Fig. 6 shows a configuration used when the ends of a plurality of the reinforcing
bars 11 arranged at a predetermined pitch are at irregular positions, respectively.
In this case, the positions of the steel plates 5 serving as the anchoring portion
are aligned by changing the securing position of each anchoring member 3 secured by
the sleeve 2 and the wedge member 6 to the corresponding reinforcing bar 11. In this
configuration, even when the ends of the reinforcing bars are arranged irregularly
due to construction error during bar arrangement, the anchorage forces of the reinforcing
bars 11 can be adjusted to a constant level by adjusting the attachment positions
of the anchoring members 3.
[0045] In the present embodiment, the anchoring portion of the anchoring member is formed
as a circular plate-like body. However, a plate-like body having any shape may be
used, and the plate-like body can for example be formed as an ellipsoidal plate-like
body, a rectangular plate-like body, a substantially rectangular plate-like body formed
by chamfering or bending corners of a rectangular plate, or the like. In addition,
the reinforcing bar insertion opening may be formed not only into a notch shape but
also as a circular hole.
[0046] The anchoring portion is not limited to being formed as a plate-like body. The anchoring
portion may have any shape and any structure, so long as it acts as an anchor in concrete.
[0047] Fig. 7(a) is a front view showing a state where an anchoring member of an example,
which is not part of the invention, is attached to the reinforcing bar 11. An anchoring
member 61 shown in Fig. 7(a) includes an anchoring portion 62 bent into a semicircular
shape and the connection rod 4 extending from the end portion of the anchoring portion
62. For example, the anchoring member 61 may be formed by bending a straight steel
rod into a J-shape.
[0048] Also in this configuration, the anchoring member 61 can be attached at any position
on the reinforcing bar 11 using the sleeve 2 and the wedge member 6. Further, although
the attachment position is slightly limited in this case, the anchoring member 61
can be attached to the reinforcing bar 11 such that the anchoring portion 62 is positioned
on a line extending from the reinforcing bar 11, as shown in Fig. 7(b). Such an attachment
configuration enables more compact installation.
[0049] Fig. 8(a) shows an anchoring member of another modification, and Fig. 8(b) is a perspective
view showing a state where the anchoring member of this modification is attached to
the reinforcing bar 11. The anchoring member 73 shown in the figures includes: an
annular-shaped body 71 bent into a rectangular frame shape and serving as the anchoring
portion; and the connection rod 4 extending from the end portion of the annular body
71 in a direction perpendicular to a plane formed by the annular-shaped body 71. The
anchoring member 73 is configured such that the reinforcing bar 11 can be inserted
into a space 74 surrounded by the annular-shaped body 71.
[0050] For example, the anchoring member 73 can be formed by bending a straight steel rod
into a rectangular frame shape.
[0051] Also in this configuration, as in the embodiment described above, interference between
the annular-shaped body 71 serving as the anchoring portion and the reinforcing bar
11 can be prevented, and therefore the anchoring member 73 can be attached at any
position on the reinforcing bar 11.
[0052] In the embodiment shown in Figs. 1 to 6, the reinforcing bar insertion opening 12
for allowing the reinforcing bar to pass therethrough is provided in the plate 5.
However, the reinforcing bar insertion opening may not be provided.
[0053] Fig. 9 is an exploded perspective view illustrating an anchorage 1a including: an
anchoring member 3a in place of the anchoring member 3; the sleeve 2; and the wedge
member 6. The anchoring member 3a includes: a circular steel plate 5a serving as the
anchoring portion and not having the reinforcing bar insertion opening; and the connection
rod 4 provided upright on the steel plate 5a.
[0054] Also in this example, which is not part of the invention, as in the embodiment described
above, labor involved in threading the reinforcing bar is omitted, and the operational
advantage that the anchoring member 3a can be firmly joined to the reinforcing bar
11 can be obtained. Moreover, since the anchoring member 3a need not be rotated when
being attached to the reinforcing bar 11, the operational advantage of preventing
the anchoring member 3a from interfering with other reinforcing bars during attachment
operation can be obtained. In addition, since the anchoring member 3a can be firmly
secured to the reinforcing bar 11 simply by press-fitting the wedge member 6, the
operational advantage of significantly improving the workability of the bar arrangement
operation at a worksite can be obtained.
[0055] In the present embodiment, the reinforcing bar anchorage is composed of a single
sleeve 2. However, in place of this configuration, the reinforcing bar anchorage may
be composed of two sleeves 2, 2 arranged in series, the anchoring member 3, and the
wedge member 6, 6 as shown in Fig. 10(a).
[0056] In this modification, the reinforcing bar 11 and the connection rod 4 of the anchoring
member 3 are inserted into both the two sleeves 2, 2 arranged in series, and the wedge
members 6, 6 are inserted, for press-fitting, into the wedge insertion holes 9, 9
formed in each of the sleeves 2, 2.
[0057] Moreover, a sleeve 91 shown in Fig. 10(b) may be used in place of the sleeve 2. In
this case, two pairs of the wedge insertion holes 9, 9 are formed in the sleeve 91
so as to be parallel to the axis of the reinforcing bar 11. In this instance, two
wedge members 6, 6 are inserted, for press-fitting, into the respective pairs of the
wedge insertion holes 9, 9 formed in the sleeve 91.
[0058] In the present embodiment, the anchoring member 3 includes the substantially circular
steel plate 5 serving as a plate-like body and the connection rod 4 provided upright
on the steel plate 5. However, the connection rod is not necessarily composed of a
single body.
[0059] Figs. 11 and 12 show such a modification. An anchoring member 103 shown in the figures
includes: a connection rod including two connection rod bodies 104, 104 parallel to
each other; and an ellipsoidal steel plate 105 serving as a plate-like body on which
the connection rod bodies 104, 104 are provided upright.
[0060] A reinforcing bar anchorage 101 using the anchoring member 103 is provided with a
sleeve 102 which allows then reinforcing bar 11 and the two connection rod bodies
104, 104 to pass therethrough with the reinforcing bar 11 sandwiched between the two
connection rod bodies 104, 104. The sleeve 102 includes: a pair of semicylindrical
wall portions 7, 7 which are arranged such that the curved inner surfaces thereof
are opposed to each other; and a pair of flat wall portions 8a, 8a each extending
to the corresponding edges of the respective semicylindrical wall portions 7, 7. Two
pairs of wedge insertion holes 9, 9 are formed in the pair of flat wall portions 8a,
8a. Each pair of wedge insertion holes 9, 9 is formed at a position between the reinforcing
bar 11 and one of the two connection rod bodies 104, 104, and the two pairs of wedge
insertion holes 9, 9 are arranged substantially symmetrically with respect to the
axis of the reinforcing bar 11.
[0061] In addition, the reinforcing bar anchorage 101 is provided with two wedge members
6, 6 which are to be inserted into the respective pairs of wedge insertion holes 9,
9 for press-fitting. When the wedge members 6, 6 are press-fitted between the reinforcing
bar 11 and the respective connection rod bodies 104, 104, the wedge members 6, 6 bite
into and engage with the reinforcing bar 11 and the respective connection rod bodies
104, 104 by taking the reaction force from the respective semicylindrical wall portions
7, 7 of the sleeve 102.
[0062] A circular hole-shaped reinforcing bar insertion opening 112 is formed in the steel
plate 105 of the anchoring member 103, so that the reinforcing bar 11 can pass through
the reinforcing bar insertion opening 112.
[0063] With the above configuration, operational advantages similar to those in the embodiment
described above can also be obtained. In this configuration, the anchoring member
103 is more firmly secured to the reinforcing bar 11, and the tensile force from the
reinforcing bar 11 is transmitted to the steel plate 105 serving as the anchoring
portion without being decentered since the securing structure of the anchoring member
103 is symmetric with respect to the axis of the reinforcing bar 11. Hence, in addition
to the above operational advantages, another remarkable operational advantage is obtained,
i.e., more stable anchoring.
[0064] Next, a description will be given of a reinforcing bar anchorage according to a further
example, which is not part of the invention. It should be noted that components and
the like substantially identical to those of the first embodiment will be designated
by the same reference numerals, and a description thereof will be omitted.
[0065] Figs. 13(a) and 13(b) are a front view and a sectional view, respectively, showing
a reinforcing bar anchorage according to the present embodiment. As can be seen from
these figures, the reinforcing bar anchorage 121 according to the present embodiment
includes: an anchoring member 122 including a sleeve having an ellipsoidal cross-sectional
shape; an anchoring member-securing rod 123 having a circular cross-section and formed
from a straight steel rod; and a wedge member 6.
[0066] The anchoring member 122 is configured such that the anchoring member-securing rod
123 and the reinforcing bar 11 can be inserted thereinto so as to be parallel to each
other with the anchoring member-securing rod 123 and the reinforcing bar 11 overlapping
each other by a predetermined length. Similarly to the sleeve 2, the anchoring member
122 includes: a pair of semicylindrical wall portions 7, 7 which are arranged such
that the curved inner surfaces thereof are opposed to each other; and a pair of flat
wall portions 8, 8 each extending to the corresponding edges of the respective semicylindrical
wall portions 7, 7. Each of the wedge insertion holes 9, 9 is formed in one of the
pair of flat wall portions 8, 8. Specifically, the wedge insertion holes 9, 9 are
formed at respective positions between the reinforcing bar 11 and the anchoring member-securing
rod 123 so as to be opposed to each other.
[0067] The wedge member 6 is designed to be inserted into the wedge insertion holes 9, 9
for press-fitting. When the wedge member 6 is press-fitted between the reinforcing
bar 11 and the anchoring member-securing rod 123, it bites into and engages the reinforcing
bar 11 and the anchoring member-securing rod 123 by taking the reaction force from
the semicylindrical wall portions 7, 7 of the anchoring member 122.
[0068] As described above, a tapered portion of the wedge member 6 bites into both the reinforcing
bar 11 and the anchoring member-securing rod 123. Which of the reinforcing bar 11
and the anchoring member-securing rod 123 is bitten into to a larger degree depends
mainly on the difference in hardness between the two. If the tapered portion does
not sufficiently bite into the reinforcing bar 11, the engaging force between the
reinforcing bar 11 and the wedge member 6 will be insufficient.
[0069] Therefore, it is desirable that the anchoring member-securing rod 123 have a hardness
equivalent to or higher than that of the reinforcing bar 11, so that the wedge member
6 can bite into the reinforcing bar 11 sufficiently as much as allowable in design.
[0070] In contrast to the anchorage 1 of the first embodiment, in the reinforcing bar anchorage
121 according to the preset embodiment, the anchoring member-securing rod 123 and
the anchoring member 122 composed of a sleeve act as an anchor.
[0071] Therefore, the wall thickness of the anchoring member 122 is appropriately adjusted
according to a required anchorage force when the anchoring member 122 is manufactured.
Specifically, the greater the wall thickness, the larger the distance it will protrude
beyond the peripheral surface of the reinforcing bar 11 and, correspondingly, the
larger the anchorage force.
[0072] In order to attach the reinforcing bar anchorage 121 according to the present embodiment
to the reinforcing bar 11, an end portion of the reinforcing bar 11 is first inserted
through a first opening of the anchoring member 122 and allowed to pass through the
anchoring member 122. Then, the anchoring member-securing rod 123 is inserted through
the first opening or an opposite second opening of the anchoring member 122 and allowed
to pass through the anchoring member 122.
[0073] Next, the anchoring member 122 is slid relative to the reinforcing bar 11 so as to
be located at a desired position.
[0074] After completion of the alignment of the anchoring member 122, the wedge member 6
is inserted into the wedge insertion holes 9, 9 for press-fitting. An appropriate
known wedge driver may be selected and used for press-fitting.
[0075] As described above, in the reinforcing bar anchorage 121 according to the present
embodiment, the anchoring member 122 is attached to the reinforcing bar 11. In this
case, the anchoring member-securing rod 123 and the reinforcing bar 11 are inserted
into the anchoring member 122 so as to be arranged with the anchoring member-securing
rod 123 and the reinforcing bar 11 overlapping each other by a predetermined length.
In this state, the wedge member 6 is inserted into the wedge insertion holes 9, 9
for press-fitting. Hence, the anchoring member 122 can be firmly joined to the reinforcing
bar 11 without machining the reinforcing bar. Therefore, conventionally required labor
involved in threading the reinforcing bar can be omitted. In addition to this, since
the anchoring member 122 can be firmly secured to the reinforcing bar 11 simply by
press-fitting the wedge member 6, the operational advantage of significantly improving
the workability of the bar arrangement operation at a worksite can be obtained.
[0076] Moreover, with the reinforcing bar anchorage 121 according to the present embodiment,
since the anchoring member 122 need not be rotated when being attached to the reinforcing
bar 11, the anchoring member 122 is prevented from interfering with other reinforcing
bars during the attachment operation. This, along with simplification of the securing
operation described above, allows a further improvement in the efficiency of the bar
arrangement operation.
[0077] The present embodiment is configured such that a required anchorage force is provided
by adjusting the wall thickness of the anchoring member 122. However, an anchoring
member 133 shown in Fig. 14, which is not part of the invention may be used which
includes: a sleeve 132 having the same configuration as that of the anchoring member
122; and a flange-like protrusion 131 provided on the periphery of the sleeve 132.
[0078] In this configuration, a large anchorage force can be ensured by combined anchorage
from the sleeve 132 and from the flange-like protrusion 131. Moreover, a desired anchorage
force can be ensured by changing the shape and dimensions of the flange-like protrusion
131, particularly the height of the protrusion from the sleeve 132.
[0079] In the present embodiment, the reinforcing bar anchorage is composed of the single
anchoring member 122. However, in place of this configuration, which is not part of
the invention, two anchoring members 122, 122 arranged in series may be provided,
as shown in Fig. 15(a). In this case, the reinforcing bar anchorage can be composed
of the two anchoring members 122, 122, the anchoring member-securing rod 123, and
two wedge members 6, 6.
[0080] In this modification, the reinforcing bar 11 and the anchoring member-securing rod
123 are inserted into both the two anchoring members 122, 122. Each of the wedge members
6, 6 is inserted, for press-fitting, into a pair of the wedge insertion holes 9, 9
formed in a respective one of the anchoring members 122, 122.
[0081] Moreover, an anchoring member 141 shown in Fig. 15(b), which is not part of the invention
may be used in which two pairs of the wedge insertion holes 9, 9 are formed so as
to be parallel to the axis of the reinforcing bar 11. Two wedge members 6, 6 are inserted,
for press-fitting, into the respective pairs of the wedge insertion holes 9, 9 formed
in the anchoring member 141.
[0082] The reinforcing bar anchorage does not necessarily include a single anchoring member-securing
rod. As shown in Fig. 16, two anchoring member-securing rods 123, 123 may be provided.
In this case, the reinforcing bar anchorage can be composed of: the two anchoring
member-securing rods 123, 123; an anchoring member 151 which is configured so as to
allow the two anchoring member-securing rods 123, 123 and the reinforcing bar 11 to
pass therethrough with the reinforcing bar 11 sandwiched between the two anchoring
member-securing rods 123, 123; and the wedge members 6, 6. Two pairs of the wedge
insertion holes 9, 9 are formed in the anchoring member 151. Each pair of the wedge
insertion holes 9, 9 is formed at a position between the reinforcing bar 11 and one
of the anchoring member-securing rods 123, 123, and the two pairs of the wedge insertion
holes 9, 9 are arranged substantially symmetrically with respect to the axis of the
reinforcing bar 11.
[0083] In this modification, the reinforcing bar 11 and the anchoring member-securing rods
123, 123 are inserted into the anchoring member 151 such that the reinforcing bar
11 is sandwiched between the anchoring member-securing rods 123, 123. Then, the two
wedge members 6, 6 are inserted into the respective pairs of the wedge insertion holes
9, 9 for press-fitting.
[0084] In addition, a flange-like protrusion similar to that shown in Fig. 14 may be provided
on the periphery of the anchoring member 151.
[0085] Fig. 17 is a front view showing a reinforcing bar anchorage according to a yet further
example, which is not part of the invention, and Figs. 18(a) and 18(b) are sectional
views thereof. As can be seen from these figures, the reinforcing bar anchorage 161
includes a sleeve 166 having an ellipsoidal cross-sectional shape, an anchoring member
163, two anchoring member-securing rods 162, 162, and the wedge members 6.
[0086] The anchoring member 163 includes a circular steel plate 165 serving as an anchoring
portion and a series connection rod 164 provided upright on the steel plate 165. The
series connection rod 164 is formed from a straight steel rod having a circular cross-section.
[0087] The sleeve 166 is configured so as to allow the series connection rod 164, the reinforcing
bar 11, and the two anchoring member-securing rods 162, 162 to be inserted thereinto.
The series connection rod 164 and the reinforcing bar 11 are arranged such that the
axes thereof are aligned on the same straight line, and the two anchoring member-securing
rods 162, 162 are arranged so as to sandwich the series connection rod 164 and the
reinforcing bar 11 therebetween. As can be clearly seen in Fig. 18(a), the sleeve
166 includes: a pair of the semicylindrical wall portions 7, 7 which are arranged
such that the curved inner surfaces thereof are opposed to each other; and a pair
of the flat wall portions 8a, 8a each extending to the corresponding edges of the
respective semicylindrical wall portions 7, 7.
[0088] The wedge insertion holes 9, 9 are formed in the pair of flat wall portions 8a, 8a.
Specifically, the wedge insertion holes 9, 9 are formed at respective positions between
the reinforcing bar 11 and the respective anchoring member-securing rods 162, 162
so as to be opposed to each other. Similarly, the wedge insertion holes 9, '9 are
formed respective positions between the series connection rod 164 and the respective
anchoring member-securing rods 162, 162 so as to be opposed to each other. The wedge
insertion holes 9, 9 are formed on both sides of the axis of the reinforcing bar 11
so as to be symmetric with respect to that axis. Hence, four pairs of the wedge insertion
holes 9, 9 are formed in the flat wall portions 8a, 8a.
[0089] The wedge members 6 are designed so as to be inserted into the wedge insertion holes
9, 9 for press fitting. When the wedge members 6 are press-fitted between the reinforcing
bar 11 and the respective anchoring member-securing rods 162, 162, the wedge members
6 bite into and engage the reinforcing bar 11 and the respective anchoring member-securing
rods 162, 162 by taking the reaction force from the respective semicylindrical wall
portions 7, 7 of the sleeve 166.
[0090] Similarly, when the wedge members 6 are press-fitted between the series connection
rod 164 and the respective anchoring member-securing rods 162, 162, the wedge members
6 bite into and engage the series connection rod 164 and the respective anchoring
member-securing rods 162, 162.
[0091] As described above, tapered portions of the wedge members 6 bite into both the reinforcing
bar 11 and the respective anchoring member-securing rods 162, 162 or both the series
connection rod 164 and the respective anchoring member-securing rods 162, 162. Which
of the reinforcing bar 11 and the anchoring member-securing rod 162 or the series
connection rod 164 and the anchoring member-securing rod 162 is bitten into to a larger
degree depends mainly on the difference in hardness between the reinforcing bar 11
and the anchoring member-securing rod 162 or between the series connection rod 164
and the anchoring member-securing rod 162. If the tapered portions do not sufficiently
bite into the reinforcing bar 11 or the series connection rod 164, the engaging force
between the wedge member 6 and the reinforcing bar 11 or between the wedge member
6 and the series connection rod 164 will be insufficient.
[0092] Therefore, it is desirable that the anchoring member-securing rods 162 have a hardness
equivalent to or higher than that of the reinforcing bar 11 or the series connection
rod 164, so that the wedge member 6 can bite into the reinforcing bar 11 or the series
connection rod 164 to the extent permitted by the design.
[0093] In order to attach the reinforcing bar anchorage 161 according to the present embodiment
to the reinforcing bar 11, an end portion of the reinforcing bar 11 is first inserted
through a first opening of the sleeve 166. Then, the series connection rod 164 of
the anchoring member 163 is inserted through an opposite second opening of the sleeve
166.
[0094] Before or after the above insertion operation, the anchoring member-securing rods
162, 162 are inserted into the sleeve 166 so as to sandwich the reinforcing bar 11
and the series connection rod 164 therebetween.
[0095] Next, the wedge members 6 are inserted into the respective wedge insertion holes
9, 9 for press-fitting. An appropriate known wedge driver may be selected and used
for press-fitting.
[0096] As described above, in the reinforcing bar anchorage 161 according to the present
embodiment, when the anchoring member 163 is attached to the reinforcing bar 11, the
series connection rod 164 of the anchoring member 163 and the reinforcing bar 11 are
inserted into the sleeve 166 such that the axis of the series connection rod 164 is
aligned with the axis of the reinforcing bar 11. In addition to this, the anchoring
member-securing rods 162, 162 are inserted into the sleeve 166 so as to sandwich the
series connection rod 164 and the reinforcing bar 11 therebetween. In this state,
the wedge members 6 are inserted into the respective pairs of the wedge insertion
holes 9, 9 for press-fitting. Hence, the anchoring member 163 can be firmly joined
to the reinforcing bar 11 without machining the reinforcing bar 11. Therefore, conventionally
required labor involved in threading the reinforcing bar can be omitted. In addition
to this, since the anchoring member 163 can be firmly secured to the reinforcing bar
11 simply by press-fitting the wedge members 6, the operational advantage of significantly
improving the workability of the bar arrangement operation at a worksite can be obtained.
[0097] Moreover, in the reinforcing bar anchorage 161 according to the present embodiment,
since the anchoring member 163 need not be rotated when being attached to the reinforcing
bar 11, this can prevent the anchoring member 163 from interfering with other reinforcing
bars during the attachment operation. This, along with simplification of the securing
operation described above, allows a further improvement in the efficiency of the bar
arrangement operation.
[0098] Furthermore, in the reinforcing bar anchorage 161 according to the present embodiment,
the anchoring member-securing rods 162, 162 are configured so as to be capable of
sandwiching the series connection rod 164 and the reinforcing bar 11 therebetween.
Hence, the anchoring member 163 can be more firmly secured to the reinforcing bar
11, and the tensile force from the reinforcing bar 11 can be transmitted to the anchoring
member 163 without being decentered since the anchoring member 163 can be attached
symmetrically with respect to the axis of the reinforcing bar 11. Therefore, more
stable anchoring can be achieved.
[0099] In the present embodiment, two anchoring member-securing rods are used so as to be
capable of sandwiching the series connection rod 164 and the reinforcing bar 11 therebetween.
However, the two anchoring member-securing rods of the invention are not necessarily
provided. Only a single anchoring member-securing rod may be provided as shown in
Fig. 19.
[0100] Also in such a configuration, the following operational advantages can be obtained
as in the embodiments described above. For example, conventionally required labor
involved in threading the reinforcing bar is omitted. The workability of bar arrangement
operation at a workplace can be significantly improved. The bar arrangement operation
can be carried out more efficiently since the anchoring member is prevented from interfering
with other reinforcing bars during the attachment operation.
[0101] In the present embodiment, the circular steel plate 165 serves as the anchoring portion
of the anchoring member in accordance with the present invention. However, a substantially
circular steel plate 194 as shown in Figs. 20 and 21(b) may be used in place of the
circular steel plate 165. The steel plate 194 has notch-shaped rod insertion openings
195, 195 formed at respective positions opposed to each other.
[0102] The rod insertion openings 195, 195 are configured to allow the respective anchoring
member-securing rods 162, 162 to pass therethrough.
[0103] In this modification, an anchoring member 193 serving as the anchoring member in
accordance with the invention includes the substantially circular steel plate 194
serving as the anchoring portion and the series connection rod 164 provided upright
on the steel plate 194.
[0104] In this modification, interference between the steel plate 194 and each of the anchoring
member-securing rods 162, 162 can be prevented by the rod insertion openings 195,
195 formed in the steel plate 194 serving as the anchoring portion. Hence, the limitation
on the attachment positions of the anchoring member-securing rods 162, 162 is relaxed,
whereby the workability is improved.
[0105] Moreover, circular hole-shaped rod insertion openings shown in Figs. 22 and 23(b)
may be employed in place of the notch-shaped rod insertion openings 195, 195.
[0106] In the modification shown in these figures, an anchoring member 213 includes a substantially
circular steel plate 214 serving as the anchoring portion and the series connection
rod 164 provided upright on the steel plate 214. In this instance, circular hole-shaped
rod insertion openings 215, 215 are formed in the substantially circular steel plate
214 and are provided on both sides of the position on which the series connection
rod 164 is provided upright.
[0107] Each of the rod insertion openings 215, 215 is formed so as to allow a respective
one of the anchoring member-securing rods 162, 162 to pass therethrough.
[0108] In this modification, interference between the steel plate 214 and each of the anchoring
member-securing rods 162, 162 can be prevented by the rod insertion openings 215,
215 formed in the steel plate 214 serving as the anchoring portion. Hence, the limitation
on the attachment positions of the anchoring member-securing rods 162, 162 is relaxed,
whereby the workability is improved.
[0109] In the modification shown in Fig. 19 among the modifications described above, a substantially
circular steel plate 224 having a notch-shaped rod insertion opening 225 formed therein
may be employed in place of the circular steel plate 165, as shown in Fig. 24. Similarly,
as shown in Fig. 25, a substantially circular steel plate 234 may be employed which
has a circular hole-like rod insertion opening 235 formed therein.
[0110] In these modifications, interference between the steel plate 224 and the anchoring
member-securing rod 162 can be prevented by the rod insertion opening 225 formed in
the steel plate 224 serving as the anchoring portion. Hence, the anchoring member
223 can be attached at any position on the reinforcing bar 11. Similarly, interference
between the steel plate 234 and the anchoring member-securing rod 162 can be prevented
by the rod insertion opening 235 formed in the steel plate 234 serving as the anchoring
portion. Hence, the limitation on the attachment positions of the anchoring member-securing
rod 162 is relaxed, whereby the workability is improved.