KR20090009350A - Shear reinforcement assembly for a slab-column connection and shear reinforcement structure using the same - Google Patents

Abstract

A shear reinforcement for a slab-column joint and a shear reinforcement structure using the same are provided to manufacture easily by the simplification of a structural design, and to restrain the location change of a shear reinforcement against an upper reinforcing bar inserted through a channel of a shear reinforcement core member when placing concrete. A shear reinforcement for a slab-column joint comprises a shear reinforcement core member(2) composed of upper anchorages(2a) having a channel for an appropriate upper reinforcing bar of a slab, lower anchorages(2b) arranged to cross each other on the right and left parts of each lower part at regular intervals in the longitudinal direction and having a bend(2bb), and an intermediate shear portion(2c) connecting each corresponding part of the upper anchorage and the lower anchorage in a single body, and auxiliary reinforcing bars(3) arranged and fixed on two lower anchorages of the shear reinforcement core member in the longitudinal direction.

Description

SHEAR REINFORCEMENT ASSEMBLY FOR A SLAB-COLUMN CONNECTION AND SHEAR REINFORCEMENT STRUCTURE USING THE SAME}

1 is a schematic plan view and a side cross-sectional view showing examples of shear reinforcing structures conventionally applied.

Figure 2 is a schematic perspective view showing a shear stiffener for the slab-column junction according to the present invention.

Figure 3 is a schematic plan view showing a shear stiffener for the slab-column junction according to the present invention.

Figure 4 is a schematic side view showing a shear stiffener for the slab-column junction according to the present invention.

Figure 5 is a schematic perspective view showing a state where the upper reinforcement is inserted into the upper portion of the shear reinforcement for the slab-column junction according to the present invention.

Figure 6 is a schematic perspective view showing a state in which the spacer is arranged in the lower portion of the shear reinforcement for slab-column junction according to the present invention.

7 is a schematic perspective view showing a state in which a shear reinforcement body according to the present invention is disposed around a slab-column junction on a slab formwork in which a plurality of lower rebars are arranged in a lattice form about a column;

FIG. 8 is a schematic perspective view illustrating a state in which a plurality of upper rebars are disposed in a lattice form on the remaining shear reinforcement on the slab formwork of FIG. 7 and the remaining corresponding portions of the slab formwork. FIG.

Figure 9 is a schematic partial enlarged view showing the periphery of the slab-column joint on the formwork for the slab to which the shear reinforcement body according to the present invention is applied.

<Description of the symbols for the main parts of the drawings>

1: shear reinforcing body 2: shear reinforcing core member

2a: upper fixing part 2aa: channel

2b: lower fixing part 2bb: bend

2c: middle shear 3: auxiliary rebar

4: form 5: lower rebar

6: upper rebar 7: third spacer

7a: support portion 7b: metal rod

8: pillar 9: pillar stub

The present invention relates to a shear reinforcement for a slab-column joint and a shear reinforcement structure using the same, in particular a slab applied to a flat plate structure that does not apply girders or beams, such as flat slabs or flat plates. The present invention relates to a shear reinforcing body for a column joint and a shear reinforcing structure using the same.

In general, in the flat plate structure, unlike the beam-column joint, the slab-column joint generates excessive stress concentration around the column. As a result, cracks are likely to occur in the slab around the column, and in the worst case, there is a high possibility of lead to punching shear failure. Thus, the flat plate structure must be designed to be sufficiently resistant to such punching shear failure.

Therefore, in order to increase the shear strength of the slab-column joint in a flat plate structure, a stirrup method, a shear head installation method, a shear stud installation method, and the like have been widely used.

The use of the stub is widely applied as shown in Figure 1 (a), to increase the shear strength by winding the stirrup (stiff bar) on the upper and lower reinforcing bars disposed across the slab-column joint. However, this method of using the stub is economical because it is used to bend the conventional rebar, but it is very difficult to maintain a uniform coating thickness of the slab because it must surround the upper and lower reinforcement of the slab, and also the upper and lower parts of the slab. Due to the need to bind a plurality of stirrups to the reinforcing bars one by one, there was a problem that the workability of the site is reduced, the constructionability.

The shear head mounting method is to install a shear head reinforcement composed of structural steel, such as H-shaped steel or I-shaped steel as shown in Figure 1 (b) to share the shear strength by the slab-column joint. However, such a shear head installation method is not only costly due to the use of the shaped steel material, but also has a large weight, which is inconvenient to handle, and there is a high possibility of disconnection between the slab and the column reinforcement by the installed shear head reinforcement.

The shear stud installation method, as shown in Figure 1 (c), by welding a plurality of studs (stud) on the top of the flat iron plate processed in the form of a strip (strip) to form a shear reinforcement and slab-column junction It is installed in the reinforcement of shear strength. However, this shear stud installation method is easy to install but very cumbersome for welding.

Accordingly, the present invention has been made to solve the problems described above, the object is to increase the resistance to punching shear failure that can occur in the slab-column junction due to excessive or repeated external force in the flat plate structure It is to provide a shear reinforcement for the slab-column joint and a shear reinforcing structure using the same.

Another object of the present invention is to provide a shear reinforcement for a slab-column joint and a shear reinforcing structure using the same to simplify the structure and to facilitate the manufacture and to facilitate the installation.

Still another object of the present invention is to provide a slab-column joint shear reinforcement for suppressing the positional change of the shear reinforcement with respect to the upper reinforcing bar fitted to the upper part of the shear reinforcement during the concrete pouring work for the slab and the use of the same. It is to provide a shear reinforcement structure.

In order to achieve the above object, the present invention is arranged in each upper portion at regular intervals along the length and the upper fixing portion having a channel for the corresponding upper reinforcement of the slab, and the left and right of each lower portion at regular intervals along the length It is arranged in a mutually staggered form and consists of a lower fixing portion having a bent portion, and an intermediate shear portion connecting the respective corresponding portions of the upper fixing portion and the lower fixing portion, the upper fixing portion, the lower fixing portion and the front shear portion consisting of the intermediate shear portion as a single body A reinforcing core member; Provided is a shear reinforcement for a slab-column joint, characterized in that the secondary reinforcing bar is arranged on each side of the lower fixing portion of the shear reinforcing core member is made of a fixed secondary reinforcement.

In addition, the present invention is applied to a flat plate structure, a plurality of lower reinforcement and upper reinforcement is arranged on the formwork with respect to the pillar centered around each other and the upper and lower reinforcement is integrated with each other by the concrete pouring As a structure, an upper fixing part disposed at each upper part at regular intervals along its length and having a channel for a corresponding upper reinforcing bar of the slab, and arranged in a mutually staggered form on the left and right sides of each lower part at regular intervals along its length, A shear reinforcing core member composed of a lower fixing portion having an intermediate shear portion connecting the corresponding portions of the upper fixing portion and the lower fixing portion, wherein the upper fixing portion, the lower fixing portion, and the intermediate shear portion are formed of a single body; Auxiliary reinforcing bars which are disposed and fixed along lengths on both lower lower fixing parts of the shear reinforcing core member; It provides a shear reinforcing structure comprising an upper reinforcement fitted along the channel of each upper fixing portion of the shear reinforcing core member.

In addition, the present invention further provides the following specific embodiments with respect to the embodiment of the shear reinforcing structure using the shear reinforcement above.

According to an embodiment of the present invention, the lower rebar is disposed on the formwork through the first spacer, the upper reinforcement is maintained at a predetermined height relative to the lower reinforcement via the second spacer, the shear reinforcing core member The lower fixing part of the first spacer is characterized in that fixed to the formwork via a medium.

According to an embodiment of the present invention, the third spacer is composed of a support and a metal rod with a portion accommodated therein and the other portion exposed to the outside in two parts, and between the two metal rods, the lower portion of the shear reinforcing core member. It is characterized in that the bent portion of the fixing unit is fitted.

Hereinafter, each embodiment of the shear reinforcement for the slab-column joint according to the present invention and the shear reinforcing structure using the same will be described with reference to FIGS.

FIG. 2 is a schematic perspective view showing a shear reinforcement for a slab-column joint according to the present invention, and FIG. 7 is a slab-column joint around a slab formwork for a slab in which a plurality of lower rebars are arranged in a lattice form around a column. 8 is a schematic perspective view illustrating a state in which a shear reinforcement body is disposed, and FIG. 8 is a state in which a plurality of upper reinforcing bars are disposed in a lattice form on the remaining shear reinforcement body and the remaining corresponding portions of the slab formwork on the slab formwork of FIG. 7. Is a schematic perspective view showing the.

The shear reinforcement body 1 for the slab-column joint according to the present invention has a shear reinforcing core member 2 and an auxiliary reinforcing bar 3 fixed to the shear reinforcing core member as shown in FIGS. Is done.

Here, the shear reinforcing core member (2) is disposed in each upper portion at regular intervals along the length and the upper fixing portion (2a) having a channel (2aa) for the corresponding upper reinforcing bar (not shown) of the slab, Corresponding to each of the lower fixing part 2b and the upper fixing part 2a and the lower fixing part 2b, which are arranged in the form of mutually staggered to the left and right of each lower part along a length and have a bent part 2bb. It consists of the intermediate shear part 2c which connects a part. At this time, the upper fixing part (2a), lower fixing part (2b) and the middle shear portion (2c) consists of a single body. In addition, the auxiliary reinforcing bar (3) is disposed along the length on each side of the lower fixing portion (2b) of the shear reinforcing core member (2) and welded or fixed via a fastener. The channels 2aa of each of the upper fixing portions 2a are bent roundly to accommodate the corresponding upper reinforcing bars (not shown) of the slab.

Meanwhile, the shear reinforcing structure according to the present invention is applied to a flat plate structure, as shown in FIGS. 5 and 7 to 9, and a plurality of lower reinforcing bars at regular intervals on the formwork 4 with respect to the pillar. (5) and the upper reinforcement (6) is arranged, the upper and lower reinforcement is a shear reinforcement structure is integrated with each other by the concrete pour, the shear reinforcement (1) as described above, and a part of the shear reinforcement It consists of an upper reinforcement (6) fitted along the channel (2aa) of each upper fixing portion (2a) of the shear reinforcing core member (2) constituting.

Here, the lower reinforcing bar 5 is disposed on the formwork 4 via the first spacer (not shown) and the upper reinforcing bar 6 is the lower rebar through the second spacer (not shown) It is maintained at a constant height for (5). In addition, the lower fixing portion 2b of the shear reinforcing core member 2 is fixed on the die 4 via the third spacer 7 as shown in FIG. 6.

The first spacer (not shown) has a recess for receiving a portion of the lower reinforcing bar 5. The first spacer may be provided for each lower reinforcing bar 5 or may be formed to receive a plurality of lower reinforcing bars 5 in a unit form. The second spacers (not shown) are formed with recesses at both ends thereof, and each recess makes it possible to maintain a constant height between the upper bar 6 and the lower bar 5.

The third spacer 7 preferably comprises a support portion 7a made of concrete or resin and a metal rod 7b in which a portion is accommodated and the other portion is bilaterally exposed to the outside. In this case, the bent portion 2bb of the lower fixing portion 2b of the shear reinforcing core member 2 is fitted between the two metal rods 7b so that the shear reinforcing core member 2 is upper part. The positional change does not occur with respect to the reinforcing bar 6. In addition, the front ends of the two metal rods 7b are preferably bent to the outside, which makes it easy to fit the bent portion 2bb of the lower fixing portion 2b during the slab installation operation.

Next will be described with reference to Figures 5 to 9 a preferred installation process for configuring the shear reinforcement structure for the slab on the formwork around the column using the shear reinforcement for the slab-column junction of the present invention configured as described above As follows.

First, after the formwork 4 is installed around the pillar 8, a plurality of lower reinforcing bars 5 are formed on the formwork 4 around the pillar 8 via the respective first spacers (not shown). Are arranged in a lattice form (see FIG. 7).

Then, in a state where the shear reinforcement body 1 and the upper reinforcing bar 6 are prepared, the channel 2aa of the upper fixing part 2a of the shear reinforcing core member 2 constituting a part of the shear reinforcing body 1. The upper reinforcement 6 is inserted in the longitudinal direction along the crossbar, and then the shear reinforcement-upper reinforcement assembly is placed on the formwork 4 around the pillar 8 respectively (see FIG. 7). At this time, both ends of the upper reinforcement (6) for supporting each of the shear reinforcement (1) is fixed to the corresponding lower reinforcement (5) via a second spacer (not shown), respectively.

On the other hand, the lower fixing portion (2b) of each of the shear reinforcement (1) can be additionally fixed to each corresponding portion of the formwork (4) via a third spacer (not shown), which is concrete for the slab It is possible to completely suppress the positional change of each shear reinforcement (1) relative to the upper bar (6) during the pouring operation (see Figs. 6 and 7).

Then, as shown in FIG. 8, a plurality of upper reinforcing bars 6 in the form of a lattice in the remaining portion on the formwork 4 around the pillar 8 via each second spacer (not shown). To place.

Then, the column stub 9 (or column strip) is wound around the top of the column 8 at regular intervals (or before the construction of the shear reinforcement structure, the column around the top of the column 8 in advance). In a state where the stub is wound), a slab may be formed by putting a certain amount of concrete pouring on the shear reinforcing structure (see FIGS. 8 and 9).

The present invention described above is not limited to the above-described embodiments and the accompanying drawings, and simple substitutions, modifications, and changes within the technical idea of the present invention will be apparent to those skilled in the art.

As described above, the present invention enables to increase the resistance to punching shear failure that can occur in the slab-column joint due to excessive or repeated external force in the flat plate structure, as well as by simplifying the structural design To facilitate.

In addition, the present invention makes it possible to conveniently install the shear reinforcement through the upper reinforcement of the slab, or the upper reinforcing bar and the third spacer in the flat plate structure.

Furthermore, the present invention makes it possible to suppress the positional change of the shear reinforcement with respect to the upper reinforcement fitted through the channel of the shear reinforcing core member during the concrete placing work for the slab.

Claims (4)

An upper fixing part disposed at each upper part at a predetermined interval along the length and having a channel for the corresponding upper reinforcing bar of the slab, and a lower fixing part arranged at a predetermined interval along the length and intersecting to the left and right of each lower part at an interval. A shear reinforcing core member comprising an intermediate shear portion connecting the corresponding portions of the upper fixing portion and the lower fixing portion, wherein the upper fixing portion, the lower fixing portion, and the intermediate shear portion are formed of a single body; Auxiliary rebars arranged and fixed along the length on both lower fixing portions of the shear reinforcing core member Shear reinforcement for slab-column joints. It is applied to flat plate structure, and it is a shear reinforcement structure in which a plurality of lower reinforcing bars and upper reinforcing bars are arranged at regular intervals on the formwork around the column, and the upper and lower reinforcing bars are integrated with each other by concrete pouring. An upper fixing part disposed at each upper part at a predetermined interval along the length and having a channel for the corresponding upper reinforcing bar of the slab, and a lower fixing part arranged at a predetermined interval along the length and intersecting to the left and right of each lower part at an interval. A shear reinforcing core member comprising an intermediate shear portion connecting the corresponding portions of the upper fixing portion and the lower fixing portion, wherein the upper fixing portion, the lower fixing portion, and the intermediate shear portion are formed of a single body; Auxiliary reinforcing bars disposed and fixed along lengths on both lower lower fixing portions of the shear reinforcing core member; Upper reinforcing bars fitted along the channels of the upper fixing portions of the shear reinforcing core members Shear reinforcement structure comprising a. 3. The method of claim 2, wherein the lower reinforcing bar is disposed on the formwork via the first spacer, the upper reinforcing bar is maintained at a constant height relative to the lower reinforcing bar through the second spacer, the corresponding of the shear reinforcing core member The bottom fixing part is a shear reinforcement structure that is fixed on the formwork through the third spacer. 4. The third spacer of claim 3, wherein the third spacer comprises a support and a metal rod with a portion accommodated therein and the other portion exposed to the outside in two parts, and between the two metal rods, a corresponding lower fixing portion of the shear reinforcing core member. Shear reinforcement structure in which the bent portion is fitted.

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