[Document Name]Description
[Title of the invention]To provide a reinforcing metal fitting in the through hole of
the beam made of reinforced concrete.
[Claim(s)]
[Claim 1]In the reinforcing metal fitting of the through hole of reinforced concrete
or steel framed reinforced concrete construction, the reinforcing metal fitting has 2
corner parts which are square and directed toward the direction of the main
reinforcement, and both ends are parallel to the direction of the main reinforcement.
This reinforcing metal fitting for the through hole is constituted of a round bar
bent in parallel to 2 remaining corners of an iron plate in its central part, and a
round bar, and the iron plate and the round bar are arranged on the peripheral edge
of both end parts of the through hole so as to surround the part parallel to the
outer periphery of the iron plate.
[Detailed description of the invention]
[0001]
[Industrial Application]To provide a reinforcing metal fitting for a through hole of
a beam of reinforced concrete or steel reinforced concrete.
[0002]
[Prior art]In addition, the construction is performed by appropriately installing a
plurality of reinforcing bars on site. In the case where a through hole is formed in
a beam in order to insert an electric wiring, an air conditioning duct, or the like,
it is necessary to specially reinforce this portion because the beam strength locally
decreases in the vicinity of the through hole and a crack occurs across the through
hole when a large shearing force is applied. In such a case, conventionally, the
density of the reinforcement bars around the through-hole is increased by the amount
corresponding to the decrease in the beam strength accompanying the production of the
through-hole, and specifically, the beam through-hole is reinforced by arranging a
plurality of diagonal reinforcing bars or a plurality of horizontal reinforcing bars
in the beam main reinforcement, the rib and the like around the through-hole in an
oblique grid pattern or a vertical grid pattern. This is because it is not known
which direction is generated in any direction, so that the workability is very poor
for inserting the reinforcing bar in various directions, and there is a drawback that
the installation state is large and the sufficient strength of the peripheral
portion of the opening cannot be obtained, resulting in an increase in cost. Thus, in
the conventional reinforcing method, the cross-sectional area of the reinforcing bar
is changed or the number of reinforcing bars is increased. In addition, annular
reinforcing fittings have been devised to facilitate installation, I. e., concentric
or spiral or circular reinforcing fittings.
[0003]
[Problem to be solved by the invention]Although there are a spiral muscle based on a
circular muscle, a coil steel rod, a concentric steel rod, etc. in what divided
largely and arranged the straight-line steel rod to length, width, and an oblique

 direction at two kinds, i.e., the 1st, respectively, and the 2nd in the conventional
method mentioned above, In the 1 method, although it is excellent in terms of
strength, it is difficult to install, there is many variations in the installation
state, it is not possible to obtain sufficient strength, it is easy to install it in
the 2 method, but it has a problem in the direction of 45 degrees with respect to the
strength, in particular, the horizontal direction, and it has been found that the
crack of concrete around the periphery of the through-hole is enlarged. Accordingly,
it is an object of the present invention to provide a method of recovering a concrete
portion which has been lost by a through-hole in a through-hole, which recovers the
strength of a beam reduced by the hole to a level equal to or higher than that of a
non-porous portion.
[0004]
[Means for solving the problem]In the reinforcing metal fitting according to the
first aspect of the present invention, I. e., the reinforcing metal fittings of the
reinforced concrete or steel framed reinforced concrete, the reinforcing metal
fitting has 2 corners bent in the direction of the main reinforcement, and both ends
are parallel to the direction of the main reinforcement. This reinforcing metal
fitting for the through hole is constituted of a round bar bent in parallel to the
remaining 2 corner parts of an iron plate in its central part, and a pair of round
bars, and the iron plate and the round bar are arranged in pairs on the peripheral
edge of both end parts of the through hole so as to surround the outer periphery of
the iron plate.
[0005]
[Examples]FIG. 1 is a front view showing a reinforcing metal fitting of a through
hole of a beam according to an embodiment of the present invention, in which a
through hole 1 is provided with a sleeve 2 inserted into the through hole 2, and an
iron plate is disposed at the periphery of the through hole, and a square shape is
formed at the periphery of the through hole. A pair of round bars 4 supported by
upper and lower parts of an iron plate 3 are arranged so that both ends of a pair of
round bars are parallel to the direction of the main reinforcement, and the remaining
2 corner parts of the iron plate are bent in parallel to each other at the central
part, and the iron plate and the round bar are arranged so as to overlap a part
parallel to the direction of the main reinforcement and surround the outer periphery
of the iron plate. In addition, a main reinforcement 5 and a rib 6 are provided on
the outer side of the main reinforcement 4 so as to support the beam. FIG. 2 is a
sectional view taken along the line A-A in FIG. 1, and it can clearly be seen that an
overlapped portion of the round bars is wrapped with an iron plate. This is arranged
by two both ends of a through-hole, several main reinforcements 5 are horizontally
spread around the upper and lower sides, and it turns out that the stirrup 6 is
arranged perpendicularly. FIG. 3 is an enlarged view of a reinforcing metal fitting
of a through hole of a beam of the present invention, and FIG. 4 is an enlarged view
of a cross section taken along line B-B in FIG. 3. When actually used, this completed
reinforcing metal fitting is transported to the site, and it is only necessary to
install this set in situ.
[0006]Generally, shear forces applied to the beam will cause cracks at an angle of 45
degrees relative to the direction of the beam and will further elongate and lead to
fracture. According to a conventional spiral or circular reinforcing metal fitting,
I. e., the 2 method described above, this angle results in a collapsed shape between
the beams. In the method of the reinforcing metal fitting using an iron plate

 according to the present invention, particularly, the shearing end stress in the
direction of 45 ° is increased. Further, since the steel plate is bent, a sufficient
adhesion of the iron plate 3 to the concrete can be secured against a shearing force
in a direction of 45 °, and a round bar 4 of the present invention surrounding the
steel plate has a sufficient fixing length, so that the adhesion effect is large in
the round bar. *. In addition, since it is possible to pack 5 sets of the same into a
carton box, it is easy to transport to a construction site and to carry it to a
mounting position at a construction site.
[0007]
[Effect of the invention]According to the present invention, it is possible to insert
reinforcing hardware around the through hole, and to reduce the reduction in the
strength of the concrete portion lost by the through hole, and to recover the
strength of the beam reduced by the hole to be equal to or higher than that of the
non-hole. Further, according to the present invention, it is possible to easily carry
out transportation at a construction site and to facilitate transportation to each
attachment site at a construction site.
[Brief description of the drawings]
FIG. 1 is a view showing a front view of a reinforcing metal fitting of a through
hole of a beam made of reinforced concrete according to the present invention ;.
FIG. 2 is a view showing a cross section taken along the line A-A of FIG. 4 when a
reinforcing metal fitting for a through hole of a beam made of reinforced concrete
according to the present invention is provided ;.
FIG. 3 is a front enlarged view of a reinforcing metal fitting of a through hole of a
beam made of reinforced concrete according to the present invention ;.
FIG. 4 is an enlarged view of a B-B cross section of a reinforcing metal fitting of a
through-hole of a reinforced concrete made beam according to the present invention
;.
[Explanation of letters or numerals]
1. Through-hole
2 Sleeve
3. Griddle
4 Round Bar
5. Main Reinforcement
6 Stirrup