KR102117753B1 - Shear Reinforcement Assemblies for Punching Shear Reinforcement of Slab and Column Joints and for Maintaining Concrete Coating Wall Thickness and Its Fabrication Method - Google Patents

Abstract

The technology disclosed in the present invention comprises a punching shear reinforcement made of a pre-assembled body to improve punching (perforation) shearing and constructability for concrete coating of the slab, as well as punching the slab and column joints with increased resistance to punching shear failure. Provides a shear reinforcement and a method for manufacturing the shear reinforcement and a concrete coating thickness maintenance.

Description

Shear Reinforcement Assemblies for Punching Shear Reinforcement of Slab and Column Joints and for Maintaining Concrete Coating Wall Thickness and Its Fabrication Method}

The present invention relates to a shear reinforcement for the reinforcement of the punching shear of the slab and the pillar joint and to maintain the concrete coating thickness and a method of manufacturing the same.

In particular, by making a punching shear reinforcement in advance and providing it to the site, it is possible to secure an economical construction capable of shortening the punching (piercing) shearing reinforcement construction time, and also integrally provided with the punching shear reinforcement. The present invention relates to a shear reinforcement and a method of manufacturing the same, which enables a precise construction to maintain a constant thickness of the concrete coating thickness of the slab with a gap maintenance angle.

In the case of a reinforced concrete structure, which is generally built in high-rise, it consists of a slab that provides a certain area while forming the floor of each floor, and a pillar that supports the slab and transmits the weight of the building and the load generated in each floor to the foundation. It is the usual form.

In such a reinforced concrete structure, in the case of a pillar, which is a joint where a slab and a pillar member meet, shear force is always applied between the slab along the periphery of the pillar. If the strength to this region is not sufficient, the risk of shear failure There is this.

In particular, the slab and column joints in a slab-free structure in which the slab is directly supported by the columns without installing girders or beams, unlike the beam and column joints, excessive stress concentration occurs around the columns, which causes the slab to be shown in FIG. 6. As shown, the punching shear fracture that forms the inverted trapezoidal shape at the junction of the pillar 10 and the slab 20 is caused. This punching shear failure is very brittle, unlike other failure modes, and is very fatal to the safety of the slab and column joints.

Therefore, in designing the building structure, special attention should be paid to this part to prevent shear failure, and as a method to increase the shear strength by reinforcing the joint between the pillar and the slab in the weightless plate structure as shown in FIG. The method of installing a drop panel and a capital around a pillar is commonly used.

However, it is possible to reduce the shear stress (shear stress) through the enlargement of the cross-section by installing the fingerboard or head as described above, but it is not only cumbersome to manufacture the formwork for the formation of the fingerboard or head, but also effective in terms of reinforcement performance. There was an unsuccessful problem.

Therefore, as a method for reinforcing the shear performance of the joint between the pillar and the slab, a method of increasing the shear strength by installing a reinforcement means such as a separate shear reinforcement at the joint has been developed and used. The following patent documents are examples of them.

While Patent Document 1 (Patent Publication No. 10-2004-0076644) aims to provide a reinforced concrete reinforcement that can replace shear reinforcement used in the construction of reinforced concrete structures, formwork space for concrete pouring A strip-shaped rail extending in one direction within; It consists of a rod-shaped body portion, a coupling portion provided at one end of the body portion and fixedly coupled to the rail, and a head portion provided at the other end of the body portion and having a larger cross-sectional area than the body portion, and extending the rail It is disclosed that it is characterized by having a plurality of studs projecting in one direction perpendicular to the direction and spaced apart from each other along the rail.

Patent Document 2 (Patent Registration No. 10-0676627) uses a plurality of shear reinforcements made in the form of a flat truss to ensure the constructability and economy while effectively increasing the strength and ductility of the slab-column joint. Said to be related to the shear reinforcement structure of the joint, a plurality of joints are installed in the joint where the slab and the pillar of the reinforced concrete structure are joined, and the shear reinforcement body reinforces the shear strength. A lower chord of one piece arranged in parallel at a predetermined interval below the upper chord; And, it is bent to have a continuous waveform, the pair is composed of a web material that is vertically bonded to both the upper and lower chords at the same time, the shear reinforcement of the slab-column joint having a flat truss shape as a whole. It is disclosed that it is provided as a characteristic configuration,

Patent document 3 (published patent No. 10-2009-0006512) provides a shear reinforcement for a slab and a pillar joint to be installed in a region where a slab and a pillar of a reinforced concrete structure are joined to increase the resistance to shear fracture. That is, the shear reinforcement includes a support, an upper bar and a lower bar. At this time, the support is formed to have a hollow parallel to the direction of the column, upper and lower through-holes perpendicular to the column are formed on the upper and lower sides, and a plurality of consecutively installed to be positioned parallel to the column in the slab. And, the upper bar is installed to be perpendicular to the column in the slab by being coupled through the upper through-hole of the support which is installed in series. And it is disclosed that the lower bar is installed to be perpendicular to the column in the slab by being coupled through the lower through hole of the support which is installed in series.

However, the shear reinforcement of the prior art as described above has a problem that the workability is deteriorated due to an increase in the number of work processes due to the problem that the work in which the workers must fix each stiffener is essential. The fixed part has a problem that the structural relationship in which rigidity is relatively weakened cannot be avoided.

In addition, in the case of the prior art, the shear reinforcement located in the slab maintains a prescribed covering thickness of the slab by placing the spacer from the bottom of the slab through the spacer, thereby maintaining the prescribed covering thickness of the slab. Maintaining the distance of the sieve has a problem that it is difficult to apply to a thin slab, and further, installation of a number of spacers has been pointed out as a problem that the workability is relatively deteriorated due to the increased number of processes at the work site.

In addition, since the spacer (thickness stone) is located between the shear reinforcement and the formwork and forms a state in which only the shear reinforcement is supported, the strong pour pressure generated during the concrete pouring operation becomes a factor that causes the spacers to escape from the shear reinforcement. By doing so, it is difficult to maintain the thickness of the reinforced concrete coating of the slab by letting the shear reinforcement body sit down on the floor. The defects in the thickness of the reinforcing bar concrete can cause rapid reinforcing of the reinforcing bar, which is a factor in shortening the life of the building.

Accordingly, there is an urgent need for the development of a punching shear reinforcement capable of solving the shortcomings of the above-mentioned prior arts and at the same time economical construction and precision construction to keep the concrete coating thickness constant at all times.

KR Patent Publication No. 10-2004-0076644 KR Patent Registration No. 10-0676627 KR Patent Publication No. 10-2009-0006512

The present invention was developed to supplement the problems of the prior art and to provide various additional advantages, and a punching shear reinforcement construction for a slab and a pillar joint is provided by constructing a punching shear reinforcement as a line assembly and providing it to a construction site. In addition to the economical construction that can facilitate the construction, it is possible to exert excellent resistance to punching shear, and also to maintain the thickness of the concrete coating thickness of the slab by maintaining the gap maintaining angle extending from the bottom side of the closed stirrup of the punching shear reinforcement. It is an object of the present invention to provide a shear reinforcement for the reinforcement of the punching shear and the concrete coating thickness of the slab and column joints, which are supported to maintain the precision, and to enable precision construction.

The above object is achieved by a punching shear reinforcement for a slab and a pillar joint provided according to the present invention and a shear reinforcement for maintaining a concrete coating thickness and a method for manufacturing the same.

Punching shear reinforcement for slab and column joints provided in accordance with one aspect of the present invention and shear reinforcement for maintaining the concrete coating thickness, spacing and number of a plurality of iron wires having a diameter of 3 to 8 mm smaller than the diameter of the closed stirrup A line assembly for shear reinforcement which is pre-assembled with the closed-type stirrups welded to the iron wires in a vertical position to be positioned at a joint portion of a column and a slab; Spacing from the bottom side of the closed-type stirrup to maintain the spacer apart from the bottom of the slab by extending the shear-assembled line assembly so that the closed-type stirrup always maintains a constant thickness of the concrete covering (脚) ), and the gap maintaining angle is installed in all of the closed stirrups or only some of the closed stirrups.

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A method of manufacturing a shear reinforcement for reinforcing punching shear and maintaining a concrete coating thickness of a slab and a pillar joint provided according to an aspect of the present invention includes: cutting and bending a rebar to form a closed stirrup; Cutting and bending the reinforcing bar to form a closed stirrup having an interval maintenance angle to maintain the concrete covering thickness of the slab at a constant thickness at all times; A plurality of 3-8mm iron wires are welded to the closed stirrup at intervals and numbers to produce a wire assembly for shear reinforcement, but the wire assembly for shear reinforcement can be positioned to be spaced a predetermined height from the bottom of the slab. Including the step of welding the closed stirrup having the gap maintaining angle to a predetermined position of the iron wire like the closed stirrup; including, at the lower end of the gap maintaining angle to prevent corrosion by oxidation of the support angle It is characterized by combining a corrosion-resistant rubber cap.

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According to the present invention, by making the punching shear reinforcement in advance and quickly providing it to the site, even an inexperienced person can easily and conveniently perform the punching (piercing) shear reinforcement construction to shorten the construction time. It gives an effect.

In addition, the gap maintenance angle integrally provided in the punching shear reinforcement supports the shear reinforcement to maintain a certain distance from the floor, thereby providing a precise construction effect to maintain the concrete coating thickness of the construction slab at all times.

1 is a perspective view showing the appearance of a shear reinforcement for reinforcing the punching shear and maintaining the concrete coating thickness of the slab and pillar joint according to the present invention,
2 is a left side view of FIG. 1,
3 is a view schematically showing a process of pre-assembling the shear reinforcement of FIG. 1,
Figure 4 is a view showing the shear reinforcement according to the present invention viewed from either side to explain the state installed on the joint of the pillar and the slab,
FIG. 5 is a view of FIG. 3 viewed from above,
6 is a schematic view for explaining a punching shear fracture mode of a pillar and a slab joint.

Advantages and features of the present invention, and methods for achieving them will be clarified with reference to embodiments described below in detail together with the accompanying drawings.

However, the present invention is not limited to the embodiments disclosed below, but will be implemented in various different forms, and only the embodiments allow the disclosure of the present invention to be complete, and the ordinary knowledge in the technical field to which the present invention pertains. It is provided to fully inform the holder of the scope of the invention, and the invention is only defined by the scope of the claims.

In addition, the terminology used in the specification of the present invention is for describing the embodiments and is not intended to limit the present invention, and the singular form includes the plural form unless specifically stated in the phrase. As used herein, "comprises" and/or "comprising" does not exclude the presence or addition of one or more other components other than the components mentioned, and unless otherwise defined, the specification of the present invention All terms used in the present invention may be used in a sense that can be commonly understood by those of ordinary skill in the art. In addition, terms defined in the commonly used dictionary are not ideally or excessively interpreted unless specifically defined.

Hereinafter, with reference to the accompanying drawings will be described in detail a more preferred embodiment of the manufacturing method and the shear reinforcement for the reinforcement of the punching shear and concrete cover thickness of the slab and pillar joint according to the present invention.

1 is a perspective view showing the appearance of a shear reinforcement for reinforcing punching shear and maintaining a concrete coating thickness of a slab and column joint according to the present invention, and FIG. 2 is a left side view of FIG. 1.

As shown in the drawing, the shear reinforcement 100 for reinforcing the punching shear of the slab and the pillar joint according to the present invention and maintaining the concrete coating thickness, the supporting iron wire 112a having a plurality of predetermined lengths having a diameter of 3 to 8 mm , 112b) and the plurality of supporting iron wires 112a and 112b, with the spacing and the number and verticality aligned, and closing gaps and stirrups 114 previously welded to the supporting iron wires 112a and 112b. (I) Closed-type stirrups 116 having 116-1 are mixedly installed to provide a wire assembly 110 for shear reinforcement.

When the spacing maintaining angle (脚) 116-1 formed in the closed stirrup 116 is installed on the slab for the shear reinforcement line assembly 110, the shear reinforcement line assembly 110 is installed on the slab bottom. Stable support so that it is located in a spaced state from the. For this reason, when the wire assembly 110 for shear reinforcement is assembled, the closed stirrup 116 having the gap retention angle 116-1 can be welded to the supporting iron wires 112a and 112b. However, the gap maintenance angle 116-1 is only necessary to maintain the predetermined distance from the slab bottom portion of the line assembly 110 for shear reinforcement, so the gap maintenance angle 116-1 is a material saving dimension. It is preferable to install the plurality of the left and right sides of the wire assembly 110 for shear reinforcement.

From the above embodiment, the longer the length of the wire assembly 110 for shear reinforcement, the more the number of closed stirrups 116 having the gap holding angle 116-1 can be installed for stable support. You will be able to understand enough.

In order to prevent corrosion such as rusting of the reinforcing wire assembly 110 for the shear reinforcement due to corrosion by contact with air, by being exposed to the concrete cover of the slab at each bottom of the gap maintaining angle 116-1. The anti-corrosion cap 120 made of rubber or resin is detachably opened so that there is no separation. Since the anti-corrosion cap 120 only needs to be prevented from oxidation, it is preferable to make it thin to save material.

The number of the closed-type stirrups 114 and 116 constituting the shear reinforcement line assembly 110 can be modified to any number depending on the length of the supporting iron wires 112a and 112b, and the closed type in the embodiment. The stirrups 114 and 116 are bending processes of the reinforcing bars prepared in one of a circular closed type or a polygonal closed type, and in this embodiment, a rectangular closed type among the multiple closed types is shown as an example.

It will be fully understood from the above-described embodiment that the size such as height and width of the closed stirrup 114 can be arbitrarily modified according to the size of the construction column.

FIG. 3 is a view schematically showing a process of pre-assembling the shear reinforcement of FIG. 1, and the line assembling process of the line assembly 110 for shear reinforcement configured as described above will be described with reference to the drawings.

As shown in the drawing, the reason for manufacturing the wire assembly 110 for shear reinforcement of the shear reinforcing body 100 is to minimize the reinforcement work of a difficult and difficult stirrup rebar in the field or at the workplace (see patent documents). This is to achieve economical construction by reducing construction time.

In the case of the wire assembly 110 for shear reinforcement according to the present invention, the rebar is cut to a predetermined length in advance to produce a closed stirrup 114, 116 having a rectangular shape as shown in FIGS. At this time, if the gap is maintained from the bottom of the slab from the bottom one side of the closed-type stirrup 116, the gap-holding angle 116-1 of a predetermined length to stably support it can be extended. The size of the closed stirrups 114 and 116 can be arbitrarily deformed according to the size of the reinforced concrete column being constructed.

When the closed stirrup 114 and the closed stirrup 116 having a gap retention angle 116-1 are completed, 3 automatically supplied by the conventional line assembly welding machine 30 schematically shown in FIG. A closed stirrup 114 having a closed spacing stirrup 114 and a spacing retention angle 116-1 by matching a predetermined distance and number with a plurality of supporting iron wires 112a and 112b having a diameter of ˜8 mm By being integrally welded to the supporting iron wires 112a and 112b, it is possible to pre-assemble the wire assembly 110 for shear reinforcement of the present invention to be installed on the joint of the reinforced concrete pillar and the slab as shown in FIG.

The space retention angle 116-1 provided by the closed stirrup 116 of the shear reinforcement line assembly 110 is spaced from a separate slab bottom when a conventional shear reinforcement is installed at the joint of the pillar and the slab. For maintenance, it provides excellent workability and workability to omit the high-precision work process of high-impede stones such as spacers.

The wire assembly welding machine 30 used in the manufacture of the wire assembly 110 for shear reinforcement is provided with a welding portion 32 that enables welding while continuously supplying a plurality of iron wires 112a and 112b continuously. , Supported wire (112a, 112b) to be continuously supplied by holding the pre-made closed type stirrup (114) or the closed type stirrup (116-1) having a gap maintaining angle (116-1) one by one holding iron wire for supporting (112a) , 112b), so that the welding portion 32 is welded after being supported vertically in a state in contact with the closed stirrups 114 and 116 and the supporting iron wires 112a and 112b are welded integrally with each other.

The welding operation of the closed-type stirrups 114 and 116 allows the worker to perform the closed-type stirrup 114 while the supporting wires 112a and 112b are progressed with a predetermined time difference in the direction of the arrow a as shown in FIG. 3. The closed type stirrups 116 are held one by one and are welded by touching the iron wires 112a and 112b, so the closed type stirrups 114 and 116 are supported by the distance between the supporting iron wires 112a and 112b with a time difference. By welding the steel wires 112a and 112b with a gap therebetween, the wire assembly 110 for shear reinforcement as shown in FIG. 1 can be completed. The length of the wire assembly 110 for shear reinforcement may be arbitrarily deformed according to the size of the reinforced concrete column to be constructed.

Since the line assembly welding machine 30 used to manufacture the stirrup line assembly 100 for shear reinforcement of the present invention is a general machine, only a part is shown as an example in this embodiment, and detailed description of other detailed configurations is omitted Did.

In the above, the thickness of the supporting iron wires 112a and 112b used in the fabrication of the shear reinforcement wire assembly 110 of the present invention, that is, a diameter of 3 to 8 mm smaller than the diameter of the closed stirrups 114 and 116 is used. do. The reason is that the supporting wires 112a and 112b need only play a role of maintaining the verticality of each stirrup and maintaining a gap to fix them integrally, so that deformation does not occur in the construction process, and thus within the scope of such a role. This is because it is advantageous to reduce production costs by using a fine iron wire.

Figure 4 is a view showing the shear reinforcement according to the present invention viewed from either side in order to explain the state installed on the joint of the pillar and the slab, Figure 5 is a view showing the view of Figure 3 from above.

As shown in the drawings, the shear reinforcement line assembly 110 constituting the shear reinforcement 100 of the present invention is quickly provided to a construction site of a reinforced concrete structure or structure to be joined to a joint between the pillar 10 and the slab 20. Reinforcement work can be easily completed only by a work process that makes the closed stirrups 114 and 116 support the upper reinforcing bar 22 and the lower reinforcing bar 24, which are reinforced to the slab 60, without additional difficult assembly work.

Such construction minimizes the stirrup work that requires the most time and labor input in the conventional shear fracture reinforcement work, while securing economical constructability to shorten the construction time, while joining the pillar 10 and the slab 20 Also acts to increase the resistance to punching shear fracture as shown in FIG. 6 acting on top.

Particularly, in the wire assembly 110 for shear reinforcement according to the present invention, the gap maintaining angle 116 extended to protrude downward from the closed stirrup 116 is stable to the formwork bottom portion 26 of the slab 20 Maintaining the distance (d) to be firmly supported, the lower portion of the closed-type stirrup (114, 116) acts to maintain the prescribed distance (d) at all times from the bottom 26 of the slab.

The stable fixing action of the gap maintaining angle 116-1 allows the lower portion of the closed stirrups 114 and 116 to maintain a constant concrete coating thickness at all times without being exposed to the outside of the slab 20.

In the case of the conventional (refer to the patent document), to maintain the concrete coating thickness of the slab, it is necessary to maintain a gap by using a high-precision stone such as a separate spacer between the shear reinforcements (or stirrups) disposed in the slab and the bottom of the slab. Had difficulty and hassle in working.

Despite this difficult task, the strong concrete pouring pressure generated when pouring concrete into the interior of the slab acts to release the spacer supporting the shear reinforcement from the bottom of the slab, and as a result, the shear reinforcement descends to the bottom of the slab. It was difficult to maintain the concrete cover thickness of the slab as prescribed. These difficulties have become worse as the slab thickness is reduced, but the present invention has an advantage in that all of these conventional problems are solved.

The space retention angle 116-1 for maintaining the distance from the slab bottom 26 of the wire assembly 110 for shear reinforcement of the present invention is provided with a corrosion protection cap 120 at the bottom, so that the housekeeping corrosion protection cap 120 ) Even when exposed to the outside of the slab bottom portion 26, the corrosion prevention cap 120 blocks air contact with the reinforcing bar to prevent corrosion.

The present invention provides the benefit of enabling reinforcement of the slab and pillar joints, and economical construction and precision construction of the slab to maintain concrete coating.

10: pillar
20: slab
100: shear reinforcement
110: Shear assembly for shear reinforcement
112a, 112b: Supporting iron wire
114: closed stirrup
116: closed-type stirrup with gap maintenance angle
116-1: Spacing angle (脚)
120: anti-corrosion cap

Claims (5)

The plurality of iron wires having a diameter of 3 to 8 mm smaller than the diameter of the closed-type stirrup are pre-assembled with the closed-type stirrups welded to the iron wires by aligning the spacing, number, and verticality, and positioned at the joint of the pillar and the slab. Wire assembly for shear reinforcement; And
Spacing from the bottom side of the closed stirrup extends to maintain the spacer assembly for the shear reinforcement from the bottom of the slab by keeping the closed stirrup at all times to maintain a constant thickness of concrete covering the space maintenance angle (脚);
The spacing holding angle is a reinforcement of the punching shear and the reinforcement of the concrete and the thickness of the slab and pillar joints, characterized in that it is installed only on some of the closed stirrups or on the closed stirrups. delete delete Cutting and bending the reinforcing bar to form a closed stirrup;
Cutting and bending the reinforcing bar to form a closed stirrup having an interval maintenance angle to maintain the concrete covering thickness of the slab at a constant thickness at all times; And
A plurality of 3-8mm iron wires are welded to the closed stirrup at intervals and numbers to produce a wire assembly for shear reinforcement, but the wire assembly for shear reinforcement can be positioned to be spaced a predetermined height from the bottom of the slab. Including the step of welding the closed stirrup having the gap maintaining angle to a predetermined position of the iron wire like the closed stirrup; and, at the bottom of the gap maintaining angle to prevent corrosion by oxidation of the gap holding angle A method of manufacturing a shear reinforcement to reinforce the punching shear and to maintain the concrete coating thickness, characterized by combining a corrosion-resistant rubber cap. delete

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