KR20240016761A - Reinforcement structure of section vulnerable to shear load of slab of piloti building and building equipped with it - Google Patents

Abstract

One embodiment of the present invention provides a reinforcement structure for a section vulnerable to slab shear load of a piloti building and a building equipped with the same. The reinforcing structure of the slab shear load vulnerable section of a piloti building according to an embodiment of the present invention includes a slab connected to an upper wall and a lower wall that are spaced apart from each other and arranged vertically in a staggered manner; Horizontal main bars are arranged to cross the upper and lower walls of the slab, and are respectively provided at the upper and lower parts of the slab; Vertical main bars arranged to cross the horizontal main bars at the top and bottom of the slab; Reinforcing bars arranged on the horizontal main bars in the slab between the upper body and the lower wall and arranged in parallel with the vertical main bars; and shear reinforcing bars coupled to reinforcing bars in the slab and disposed vertically on the slab, wherein the shear reinforcing bars include a connecting ring portion connected to the reinforcing bars; Vertical reinforcing bars connected to the connecting link portion; And it includes horizontal reinforcing bars connected to the vertical reinforcing bars and arranged adjacent to the horizontal main bars along the direction of the horizontal main bars at the lower part of the slab.

Description

Reinforcement structure of section vulnerable to shear load of slab of piloti building and building equipped with it}

The present invention relates to a reinforcing structure in the slab shear load vulnerable section of a piloti building, and more specifically, to a reinforcing structure in the slab shear load vulnerable section of a piloti building and a building equipped therewith.

Domestic low-rise multi-family housing and neighborhood living facilities use a framing system consisting of beams and columns to secure insufficient parking space on the lower floors, and most of the upper floors are piloti-type structures made of wall structures to secure a large amount of residential space. there is.

In these piloti-type structures, shear force is concentrated on the pillars of the piloti layer due to the insufficient wall volume of the piloti layer core, and they are especially vulnerable to earthquake resistance when they are eccentric core structures. In addition, discontinuous stud-transition beams occur due to vertical discontinuities in the shear walls other than the core wall. This is because the in-place offset distance between the upper and lower walls (upper and lower walls are offset from each other in the thickness direction) is relatively short and the transition beam with the discontinuous stud walls is relatively short. Because the difference in stiffness of the beam is large, direct shear force is concentrated during the collapse mechanism, raising the risk of early shear failure. In addition, for multi-family housing on each floor, the plane changes frequently, causing out-of-plane offset between the upper and lower walls (the upper and lower walls are offset from each other in the plane direction), so shear force and bending moment are concentrated on the slab, which increases the operating load. There is concern about damage such as cracks caused by .

Meanwhile, as a lot of damage occurred to these piloti-type buildings due to the recent Pohang earthquake in 2017, it was revealed that their earthquake-resistant performance was weak. Accordingly, many studies have been conducted on the response and behavior of existing piloti-type buildings, and in particular, seismic performance evaluation and seismic reinforcement methods have been mainly focused on low-rise structures (beams and columns on the first floor) that are soft or weak floors as a vertically irregular system. has been studied.

However, in addition to damage concentration due to lack of strength and rigidity of low-rise columns, as previously presented, seismic performance evaluation of slab cracks and damage due to slab stress concentration phenomenon due to early shear failure due to discontinuous stud-transition beam and out-of-plane offset between upper and lower walls. and development of reinforcement methods are needed.

There are several problems that need to be improved in the existing slab shear reinforcing bar development technology. Since most developed shear reinforcing bars can only be applied to slabs with a thickness of 250 mm or more, it is difficult to apply them to thin slabs with a thickness of 250 mm or less, which are commonly used in medium-low-storage piloti structures.

In addition, most developed shear reinforcement bars are of a type that restrains the upper and lower bending bars, similar to the stirrup details used in beams and columns. This has the problem of deteriorating constructability because it is difficult to restrain the upper and lower bending reinforcing bars due to the complicated reinforcement details of the slab. In order to meet the required shear strength, section steel is used or secondary processing such as welding and cutting of existing reinforcing bars is performed. Since this happens, there is a limit in that it leads to an increase in construction time and reduces economic feasibility.

KR 10-2007-0066867: Curved rebar assembled shear reinforcement (2007.07.04.) KR 10-2014-0131768: Shear reinforcement member for PC (Precast concrete) composite slab (2014.09.30.) KR 10-2020-0010168: Reinforcement system for reinforced concrete structures (2020.01.29.) KR 10-2014-0048496: Shear reinforcement structure of column-slab joint of building (2014.04.23.)

The purpose of the present invention to solve the above problems is to provide unit-type shear reinforcing bars that can be easily installed only on the upper bending bars, so that slab stress concentration phenomenon occurs due to out-of-plane offset between the upper and lower walls in mid- to low-rise piloti buildings. Accordingly, the aim is to provide a reinforcement structure for the slab shear load vulnerable section of a piloti building that prevents cracks and damage to the thin slab, and a building equipped with the same.

The technical problem to be achieved by the present invention is not limited to the technical problem mentioned above, and other technical problems not mentioned can be clearly understood by those skilled in the art from the description below. There will be.

The configuration of the present invention for achieving the above object is arranged on a slab connected to the upper and lower walls that are spaced apart from each other in a building and arranged vertically, and is arranged to intersect the upper wall and the lower wall in the slab. Doedoe, horizontal main bars provided at the upper and lower parts of the slab, respectively; Vertical main bars arranged to intersect with the horizontal main bars at the upper and lower parts of the slab; Reinforcing bars arranged on the horizontal main bars in the slab between the upper body and the lower wall and arranged in parallel with the vertical main bars; And a shear reinforcing bar coupled to the reinforcing bar in the slab and disposed vertically on the slab, wherein the shear reinforcing bar includes a connecting ring portion connected to the reinforcing bar; Vertical reinforcing bars connected to the connecting link portion; and a horizontal reinforcing bar connected to the vertical reinforcing bar and disposed adjacent to the horizontal main bar along the direction of the horizontal main bar at the bottom of the slab. It provides a reinforcing structure for the slab shear load vulnerable section of the piloti building.

In one embodiment of the present invention, the connecting ring portion includes a ring reinforcing bar that surrounds the reinforcing bar and is inclined to a plane perpendicular to the center line of the reinforcing bar; And it may include a locking reinforcing bar that is bent from the ring reinforcing bar and supported in contact with the bottom surface of the reinforcing bar.

In one embodiment of the present invention, the vertical reinforcing bars and horizontal reinforcing bars may be provided in a “┻” shape.

In one embodiment of the present invention, the vertical reinforcing bars and the horizontal reinforcing bars are provided in a “┛” shape, and other vertical reinforcements are connected to the horizontal reinforcing bars and form a “┗┛” shape together with the vertical reinforcing bars. rebar; And it may further include a ring-shaped crossing reinforcing bar that secures the other vertical reinforcing bars to the vertical main bars.

Another configuration of the present invention is to be placed on a slab connected to an upper wall and a lower wall that are spaced apart from each other and arranged vertically in a building, and is arranged to intersect the upper wall and the lower wall in the slab, and the upper and lower parts of the slab are horizontal main bars arranged at the lower part; Vertical main bars arranged to intersect with the horizontal main bars at the upper and lower parts of the slab; and shear reinforcing bars arranged to cross the horizontal main bars in the slab between the upper body and the lower wall, and arranged from the top to the bottom of the slab, wherein the shear reinforcing bars extend from the top to the bottom of the slab. A plurality of oblique muscles arranged obliquely; A plurality of horizontal reinforcing bars connected to the inclined bars at the lower part of the slab and disposed adjacent to the horizontal main bars; And it provides a reinforcing structure for the slab shear load vulnerable section of a piloti building, including connecting reinforcing bars that interconnect the plurality of inclined bars and the plurality of horizontal reinforcing bars.

In another embodiment of the present invention, the connecting reinforcing bar is a “┗┛” shaped slope that connects the plurality of oblique bars to each other and forms a ring shape at the upper end of the plurality of oblique bars to span the vertical main bar. connecting rebar; And it includes horizontal connecting reinforcing bars of a “┏┓” shape, which interconnect the plurality of horizontal reinforcing bars, and the inclined connecting reinforcing bars and the horizontal connecting reinforcing bars may be arranged at vertical intervals.

In another embodiment of the present invention, a vertical reinforcement groove may be provided between the horizontal reinforcing bar and the inclined connecting reinforcing bar to allow the vertical main bar to pass through.

In another embodiment of the present invention, the connecting reinforcing bars connect the plurality of inclined bars and the plurality of horizontal reinforcing bars to correspond to each other, and the plurality of inclined bars are located on the lower side adjacent to the upper end of any one of the plurality of inclined bars. An inclined reinforcing bar connecting any one of the horizontal reinforcing bars; and a bent ring reinforcing bar connecting the inclined bar and the inclined reinforcing bar, wherein the bent ring reinforcing bar is disposed on a central portion of the horizontal reinforcing bar, and the inclined bar, the horizontal reinforcing bar, and the inclined reinforcing bar are at the front. It may be provided in a shape that is projected onto the image as an isosceles triangle.

In another embodiment of the present invention, the inclined reinforcing bar and the inclined bar may be provided in a shape projected into a right triangle shape on the side surface.

Another configuration of the present invention can provide a building including a reinforcing structure in a section vulnerable to slab shear load of the piloti building.

The effect of the present invention according to the above configuration is to provide a unit-type shear reinforcing bar that can be easily installed only on the upper bending reinforcing bar, and as the slab stress concentration phenomenon occurs due to the out-of-plane offset between the upper and lower walls in mid- to low-rise piloti buildings, the thin It can provide the advantage of preventing cracks and damage to the slab.

The effects of the present invention are not limited to the effects described above, and should be understood to include all effects that can be inferred from the configuration of the invention described in the detailed description or claims of the present invention.

Figure 1 is a conceptual diagram of a reinforcement structure in a section vulnerable to slab shear load of a piloti building according to an embodiment of the present invention.
Figure 2 is a conceptual diagram of installing the shear reinforcing bar of Figure 1 on the reinforcing bar and the vertical main bar.
Figure 3 is a detailed view of the shear reinforcing bars and reinforcing bars of Figure 2.
Figure 4 is a conceptual diagram of installing shear reinforcing bars to reinforcing bars according to another embodiment of the present invention.
Figure 5 is a detailed view of the shear reinforcing bars and reinforcing bars of Figure 4.
Figure 6 is a conceptual diagram of shear reinforcing bars installed in reinforcing bars according to another embodiment of the present invention.
Figure 7 is a detailed view of the shear reinforcing bar of Figure 6.
Figure 8 is a state diagram of installing the shear reinforcing bar of Figure 6 in the vertical main bar.
Figure 9 is a conceptual diagram of installing shear reinforcing bars to reinforcing bars according to another embodiment of the present invention.
Figure 10 is a detailed view of the shear reinforcing bar of Figure 9.
Figure 11 shows the shear reinforcement strain of each T-shape, U-shape, and Z-shape.
Figure 12 is a conceptual diagram of a specimen plan for a structural performance test to verify the shear reinforcement effect of embodiments of the present invention.

Hereinafter, the present invention will be described with reference to the attached drawings. However, the present invention may be implemented in various different forms and, therefore, is not limited to the embodiments described herein. In order to clearly explain the present invention in the drawings, parts that are not related to the description are omitted, and similar parts are given similar reference numerals throughout the specification.

Throughout the specification, when a part is said to be "connected (connected, contacted, combined)" with another part, this means not only "directly connected" but also "indirectly connected" with another member in between. "Includes cases where it is. Additionally, when a part is said to “include” a certain component, this does not mean that other components are excluded, but that other components can be added, unless specifically stated to the contrary.

The terms used in this specification are merely used to describe specific embodiments and are not intended to limit the present invention. Singular expressions include plural expressions unless the context clearly dictates otherwise. In this specification, terms such as “comprise” or “have” are intended to indicate the presence of features, numbers, steps, operations, components, parts, or combinations thereof described in the specification, but are not intended to indicate the presence of one or more other features. It should be understood that this does not exclude in advance the possibility of the existence or addition of elements, numbers, steps, operations, components, parts, or combinations thereof.

Hereinafter, the present invention will be described in detail with reference to the attached drawings.

Figure 1 is a conceptual diagram of the reinforcement structure of the slab shear load vulnerable section of a piloti building according to an embodiment of the present invention, Figure 2 is a conceptual diagram of installing the shear reinforcing bars of Figure 1 on the reinforcing bars and vertical main bars, and Figure 3 is a diagram showing 2 is a detailed view of the shear reinforcing bars and reinforcing bars.

Referring to Figures 1 to 3, the reinforcement structure of the slab shear load vulnerable section of a piloti building according to an embodiment of the present invention includes an upper wall 10 and a lower wall 20 spaced apart from each other in the building and arranged vertically and staggered. ) includes horizontal main bars 40, vertical main bars 50, reinforcing bars 60, and shear reinforcing bars 100 arranged in the slab 30 connected to ).

The horizontal main bars 40 are arranged in several rows across the upper wall 10 and the lower wall 20, and are reinforced respectively at the upper and lower parts of the slab 30, and are the main bars in the horizontal direction of the slab 30. Used as bending rebar. These horizontal main bars 40 are coupled to reinforcing bars arranged in the vertical direction of the upper wall 10 and the lower wall 20 and are fixed in position.

The vertical main bars 50 are reinforcing bars arranged in multiple rows to cross the horizontal main bars 40 at the upper and lower parts of the slab 30, and are used as the main bending reinforcement bars in the longitudinal direction of the slab 30. These vertical main bars 50 are coupled to the horizontal main bars 40 and are fixed in position.

The horizontal main bars 40 and vertical main bars 50 as described above form the horizontal framework of the slab 30, which forms the internal floor of the building, by pouring concrete while installed inside the formwork, thereby forming the upper wall 10 and the lower part. It supports the wall 20 and strengthens the bending and shear stresses of the slab 30.

Some slab sections of the upper wall 10 and the lower wall 20 of the slab 30 are like a discontinuous side wall structure in which the load is not directly transferred from the upper wall 10 to the lower wall 20, but is arranged in a staggered manner, This section is vulnerable to shear load.

In some vulnerable sections of the slab 30, reinforcing bars 60 and shear reinforcing bars 100 are installed to sufficiently strengthen the shear stress.

The reinforcing bars 60 are arranged on the horizontal main bars 40 in the slab 30 between the upper wall 10 and the lower wall 20 and are arranged in parallel with the vertical main bars 50. The shear reinforcing bar 100 is coupled to the reinforcing bar 60 in the slab 30, and is completely fixed and coupled by pouring concrete while spanning the vertical main bar 50 to form a structure arranged vertically and horizontally in the slab 30. .

In this way, the shear reinforcing bar 100 is coupled to the reinforcing bar 60 and spans the vertical main bar 50, and then provides a horizontal structure adjacent to the horizontal main bar 40 at the lower part of the vertical main bar 50.

The shear reinforcing bar 100 is connected to the connecting ring part 110 connected to the reinforcing bar 60, the vertical reinforcing bar 120 connected to the connecting ring part 110, and the vertical reinforcing bar 120 to form a slab ( It includes horizontal reinforcing bars 130 disposed adjacent to the horizontal main bars 40 along the direction of the horizontal main bars 40 at the lower part of 30).

The connection ring portion 110 is a ring reinforcing bar 111 disposed inclined on a plane perpendicular to the center line of the reinforcing bar 60 while surrounding the reinforcing bar 60, and is bent from the ring reinforcing bar 111 to form a reinforcing bar 60. It may include a locking bar 112 that is supported in contact with the bottom of the.

The connecting link portion 110 serves to couple the shear reinforcing bar 100 to the reinforcing bar 60, and the vertical reinforcing bar 120 connects the connecting ring portion 110 and the horizontal reinforcing bar 130, providing horizontal reinforcement. The reinforcing bar 130 mainly serves to strengthen shear stress.

The ring reinforcing bar 111 is disposed at an angle to the reinforcing bar 60 and is supported by the engaging reinforcing bar 112 to prevent separation, so that the ring reinforcing bar 111 can be sufficiently fixed to the reinforcing bar 60.

These vertical reinforcing bars (120) and horizontal reinforcing bars (130) are provided in a “┛” shape, and other vertical reinforcing bars (121) are further connected to the horizontal reinforcing bars (130), thereby forming the existing vertical reinforcing bars (120). It can form a U type with a “┗┛” shape. At this time, the other vertical reinforcing bar 121 is provided with a ring-shaped crossing bar 140 that is fixed to the vertical main bar 50. These shear reinforcing bars (100) can be designated as U type.

In the following, redundant description will be omitted for elements with the same reference numerals as the already described reinforcing structures, and only different structures will be described.

Figure 4 is a conceptual diagram of installing shear reinforcing bars to reinforcing bars according to another embodiment of the present invention, and Figure 5 is a detailed view of the shear reinforcing bars and reinforcing bars of Figure 4.

Referring to FIGS. 4 and 5, the vertical reinforcing bar 122 and the horizontal reinforcing bar 131 of the shear reinforcing bar 101 may be provided in a “┻” shape. These shear reinforcing bars (101) can be designated as T type.

At this time, the vertical reinforcing bar 122 is coupled to the reinforcing bar 60 by the connecting ring portion 110, and the horizontal reinforcing bar 131 is placed in the lower part of the slab 30. The horizontal reinforcing bars 131 are disposed adjacent to the horizontal main bars 40 between the vertical main bars 50 to strengthen the shear stress.

Figure 6 is a conceptual diagram of shear reinforcing bars installed on reinforcing bars according to another embodiment of the present invention, Figure 7 is a detailed view of the shear reinforcing bars of Figure 6, and Figure 8 shows the shear reinforcing bars of Figure 6 being installed on the vertical main bars. This is also the state of installation.

Referring to Figures 6 to 8, the reinforcement structure of the slab shear load vulnerable section of the piloti building according to another embodiment of the present invention is intersected from the slab 30 to the upper wall 10 and the lower wall 20. The horizontal main bars 40 are disposed and respectively arranged in the upper and lower parts of the slab 30, the vertical main bars 50 are arranged to intersect the horizontal main bars 40 in the upper and lower parts of the slab 30, and the upper body and lower part. It is arranged to cross the horizontal main bars 40 in the slab 30 between the walls 20 and includes shear reinforcing bars 200 arranged from the top to the bottom of the slab 30.

The shear reinforcing bar 200 is a plurality of inclined bars 220 arranged obliquely from the upper part of the slab 30 to the lower part, and is connected to the inclined bar 220 at the lower part of the slab 30 and adjacent to the horizontal main bar 40. It includes a plurality of horizontal reinforcing bars 230 arranged, and a connecting reinforcing bar 240 that connects the plurality of inclined bars 220 and the plurality of horizontal reinforcing bars 230 to each other. These shear reinforcing bars 200 can be designated as E type.

This shear reinforcing bar 200 is a structure in which the inclined bar 220 and the horizontal reinforcing bar 230 form part of a triangular shape and are connected by connecting reinforcing bars 240: 241, 242 with height differences between the upper and lower sides, and are formed vertically. To enable placement on the main bar 50, a gap is provided in the structure of the connection reinforcement bar 240 into which the vertical main bar 50 can fit.

Accordingly, the shear reinforcing bar 200 is inserted into the vertical main bar 50, and the round apex 221 forming the upper end of the inclined bar 220 can be placed on the vertical main bar 50.

The connection reinforcement bar 240 is an inclined connection of a “┗┛” shape that connects the plurality of oblique bars 220 to each other and forms a ring shape for spanning the vertical main bar 50 at the upper end of the plurality of oblique bars 220. It includes a reinforcing bar (241) and a horizontal connecting reinforcing bar (242) that connects a plurality of horizontal reinforcing bars (230) to each other to form a “┏┓” shape. At this time, the inclined connecting reinforcing bar 241 and the horizontal connecting reinforcing bar 242 are arranged in a triangular shape where the left inclined side and the bottom side are separated at upper and lower intervals, and can form a gap into which the vertical main bar 50 is inserted.

The inclined connecting reinforcing bar (241) creates a structure that connects the existing inclined bar (220) by providing an inclined bar (222) on the other side by a “┗┛” shape that is connected to the existing inclined bar (220) in an inclined structure. The horizontal connecting reinforcing bar 230 connected to the lower end of the inclined bar 220 is connected to create a stable support structure and also serves to strengthen the shear stress.

In the above, a vertical reinforcement groove 245 may be provided between the horizontal reinforcing bar 230 and the inclined connecting reinforcing bar 241 to allow the vertical main bar 50 to pass through. These vertical reinforcement grooves 245 are used as passages, or gaps, for arranging the vertical main bars 50.

In these shear reinforcing bars (200), the vertical reinforcement grooves (245) are horizontally arranged to correspond to the vertical reinforcement grooves (50), the vertical reinforcement grooves (50) are inserted into the vertical reinforcement grooves (245), and the vertical reinforcement grooves (50) are rotated 90 degrees to form the inclined reinforcement. The horizontal reinforcing bar 230 can be placed adjacent to the horizontal main bar 40 by placing the vertical main bar 50 on the side of the round apex 221 at the top of the fields 220 and 222.

Figure 9 is a conceptual diagram of installing a shear reinforcing bar to a reinforcing bar according to another embodiment of the present invention, and Figure 10 is a detailed view of the shear reinforcing bar of Figure 9.

Referring to Figures 9 and 10, the connecting reinforcing bar 250 connects a plurality of inclined bars 220 and a plurality of horizontal reinforcing bars 230 in correspondence with each other, and is located at the upper end of any one of the plurality of inclined bars 220. An inclined reinforcing bar 260 connecting one of the plurality of horizontal reinforcing bars 230 on the neighboring lower side, and a bent ring reinforcing bar 265 connecting the inclined bar 220 and the inclined reinforcing bar 260. Includes.

This shear reinforcing bar 201 is a structure in which the inclined bar 220 and the horizontal reinforcing bar 230 are repeatedly connected by the inclined reinforcing bar 260, which is inclined in the front and rear diagonal directions, and isosceles triangles without one side are formed back and forth. It forms a connected structure. At this time, the shear reinforcing bar 201 can be determined as Z type.

The bent ring reinforcing bar 265 is disposed on the central portion of the horizontal reinforcing bar 230. At this time, the inclined bars 220, horizontal reinforcing bars 230, and inclined reinforcing bars 260 may be arranged in a shape projected as an isosceles triangle on the front. In this way, the shear reinforcing bar 201 is a structure projected as an isosceles triangle with a round apex 223 on the front side.

On the other hand, the inclined reinforcing bar 260 and the inclined bar 220 may be provided in a shape projected as a right triangle shape on the side surface. That is, the inclined reinforcing bar 260 has a structure connected to the inclined bar 220 that is arranged upright when viewed from the side at an acute angle.

In this way, the shear reinforcing bar 201 provides a structure that can be installed across the horizontal main bar 40 by interconnecting the inclined bar 220 and the horizontal reinforcing bar 230 by the inclined reinforcing bar 260, and provides horizontal reinforcement. The reinforcing bar 230 and the inclined reinforcing bar 260 strengthen the shear stress.

Meanwhile, according to the above-described embodiments of the present invention, it is possible to provide a building including a reinforcing structure in a section vulnerable to slab shear load of a piloti building.

Below, the reinforcement structure of the slab shear load vulnerable section of the piloti building according to embodiments of the present invention will be described.

When examining the detailed structures of conventionally used or developed shear reinforcing bars, there is a structure that surrounds both the upper and lower flexural reinforcing bars of the slab (main reinforcing bars interfere) and a structure that anchors only the upper slab flexural reinforcing bars (main reinforcing bars do not interfere). .

The structure that surrounds both the conventional upper and lower slab bending reinforcing bars is designed to surround the bending reinforcing bars so that the slab bending reinforcing bars can exert a restraining force, similar to the shear reinforcing bars (stirrup) used for shear reinforcement of beams and columns, and only applies to the upper bending reinforcing bars. In the case of an anchoring structure, shear reinforcing bars are anchored vertically to the upper bending reinforcing bars.

Comparing the present invention with this conventional shear reinforcing bar structure for slabs, the differences of the shear reinforcing bar structure installed in the shear vulnerable section of the slab according to the present invention are as follows.

1) Since the shear reinforcement proposed in the present invention can additionally reinforce the proposed unit-type shear reinforcement structure regardless of the existing slab reinforcement, it does not significantly affect the main reinforcement schedule and time of the slab. Therefore, considering that construction is difficult due to interference with complex slab reinforcement when applying the prior art, the detailed structure of the proposed shear reinforcement is the upper flexural reinforcement, that is, the horizontal reinforcement placed at the top, without interference from the already placed slab reinforcement. Alternatively, it has excellent constructability because it is anchored only to the vertical main roots.

In this way, even after the construction of the internal reinforcement of the pre-reinforced slab is completed (after the upper and lower reinforcements are placed), additional reinforcement can be placed by simply settling vertically on the upper bending reinforcement, which is advantageous in the working environment. In addition, the technology proposed in the present invention can be manufactured in a factory in the form of a unit, making it easy to transport from the factory to the site, and using D10 deformed reinforcing bars is light in weight and improves constructability.

2) In addition, the shear reinforcing bar proposed in the present invention is anchored only to the upper bending reinforcing bar, and unlike the prior art structure in which the shape of the reinforcing bar and the number of effective shear reinforcing bars are fixed, the shear reinforcing bar is placed within the flexural reinforcing bar with a diameter of D10. The number and spacing of unit reinforcing bars can be freely adjusted according to the required strength and slab reinforcement span (U type, T type), which is advantageous in terms of practicality and applicability.

In other words, in the case of a piloti structure, as various wall lines are designed in the upper part to secure a large amount of residential space, the shear risk span of the slab also appears in various ways. Because of this, shear reinforcement must be manufactured or processed at the construction site to satisfy the shear design strength for each shear risk span. The proposed shear reinforcing bar has excellent field applicability and practicality in that it can be freely reinforced in the critical shear spans of various slabs by being structured to adjust the number and spacing of shear reinforcing bar units.

3) In addition, the shear reinforcing bar proposed in the present invention was developed by bending the reinforcing bar using D10 deformed reinforcing bars commonly used in construction sites, and this can be welded without using relatively expensive materials such as section steel. It is advantageous from an economic perspective because it does not require secondary processing such as cutting (U type, E type, Z type).

In other words, unlike existing structures such as using section steel or welding reinforcing bars for shear reinforcement, the development technology proposed by the present invention is a method of manufacturing by bending D10 reinforcing bars commonly used in construction sites. This is advantageous for economic efficiency in that the price of the materials used is cheaper than that of section steel, and since welding and cutting operations are not required, manufacturing costs are reduced and manufacturing time is shortened.

4) In addition, the shear reinforcing bar proposed in the present invention has a unit shape compared to most conventional shear reinforcing bars developed to prevent punching failure of the joint between the slab and the column in the slab-column flat plate structure. Because it is simple and relatively easy to adjust the size of the unit manufactured according to the slab thickness, it can be applied not only to mass plate structures but also to thin slabs commonly used in small apartment houses and piloti structures. This can further highlight the advantages of being usable under various slab cross-section size conditions.

In other words, the shear reinforcement structure of the present invention has a simple unit shape, so it is relatively easy to adjust the size of the unit manufactured according to the slab thickness, so it can be applied not only to the mass plate structure but also to thin slabs commonly used in small-scale apartment buildings and piloti structures. do. Since this can be used under various slab cross-section size conditions, its advantages can be further highlighted. As such, the present invention has excellent constructability and economic efficiency, can be applied to thin slabs of 250 mm or less, including general slabs, and has the effect of being highly practical in various slab environments that require shear reinforcement.

In addition, unlike the commonly used shear reinforcing bars (stirrups) that surround the main reinforcing bars, the shear reinforcing bars proposed in the present invention are vertically anchored only to the upper bending reinforcing bars, are not affected by the slab thickness, and do not surround the main reinforcing bars. As a structure, it is advantageous for use in thin slabs, including general slabs, in that it can reduce the slab covering thickness.

Hereinafter, the results of structural performance tests in which shear reinforcing bars were installed on reinforcing bars according to embodiments of the present invention can be referred to from the respective tables in which the values corresponding to the specimens are described.

The structural performance test results according to the examples below are the results of structural performance tests performed by developing various shear reinforcement details and applying them to the slab. The performance was verified through comparison with a standard stirrup reinforced specimen, and the shear dominance of the specimen was verified. For the sake of shape, (1) the shear span ratio (a/d) was shortened to 1.5, and (2) the reinforcement ratio of the bending reinforcement was increased to produce the results.

In order to verify the performance of the shear reinforcement developed in the present invention, all test specimens were designed to cause shear failure, and the predicted bending strength and shear strength of the specimens were calculated according to concrete structural design standards. To reach the bending performance (Mn) of the specimen, the ratio (Vd/Vn) of the required bending shear force (Vd) and shear performance (Vn) was designed to be greater than 1.0 so that shear failure occurred before bending yielding.

In this experiment, when the development details were reinforced, higher strength was developed than the standard stirrup reinforced specimen, and the flexural and shear bars showed a high strain rate as they were almost on the verge of yielding. For the specimen with a span ratio of 1.5, the strength contribution rate is about 30.8% for stirrup reinforcement, 50.5% for T-shape, 50.6% for U-shape, and 48.5% for Z-shape. The T-shape (n=3) had the best strength development ratio compared to the number of effective shear surfaces.

In order to induce shear failure of the specimen, flexural reinforcement was placed with more reinforcement than the balanced reinforcement ratio, and as a result, the strain rate of the concrete reached the ultimate strain before the reinforcement yielded. Therefore, when calculating the compression zone depth (cu), the reinforcing bar strain rate at the time of compression failure of the concrete was applied considering that the flexural reinforcing bar had not yielded. As a result of the experiment, it was confirmed that the ratio (Vd/Vu) between the required bending shear force (Vd) and the shear strength (Vu) of the specimen was 1.0 or more, indicating that shear failure occurred in all specimens.

To calculate the strength of the shear reinforcement developed in the present invention, the following two theoretical equations were used, and through comparative analysis, a theoretical equation suitable for the development technology proposed in the present invention was presented.

ACI 318-14

Choi et al.

),

The ACI evaluation equation showed low accuracy in estimating shear strength, and it was difficult to explain the failure mode. On the other hand, the Choi evaluation equation was relatively accurate in calculating the maximum shear strength.

Figure 11 shows the shear reinforcement strain of each T-shape, U-shape, and Z-shape.

The description of the present invention described above is for illustrative purposes, and those skilled in the art will understand that the present invention can be easily modified into other specific forms without changing the technical idea or essential features of the present invention. will be. Therefore, the embodiments described above should be understood in all respects as illustrative and not restrictive. For example, each component described as unitary may be implemented in a distributed manner, and similarly, components described as distributed may also be implemented in a combined form.

The scope of the present invention is indicated by the patent claims described below, and all changes or modified forms derived from the meaning and scope of the claims and their equivalent concepts should be construed as being included in the scope of the present invention.

10: upper wall 20: lower wall
30: Slab 40: Horizontal main bar
50: Vertical main bar 60: Reinforcement bar
100, 101, 200, 201: Shear reinforcement bars
110: connection link part 111: link rebar
112: Hanging rebar 120, 121, 122: Vertical reinforcing bar
130, 131: Horizontal reinforcing bar 140: Crossing reinforcing bar
220, 222: oblique muscle 221: round apex
230: Horizontal reinforcing bar
240, 250: connection rebar 241: inclined connection rebar
242: Horizontal connecting rebar 245: Vertical reinforcement groove
260: Inclined reinforcing bar 265: Bending ring rebar

Claims (10)

It is placed on the slab connected to the upper and lower walls, which are spaced apart from each other in the building and arranged vertically,
Horizontal main bars arranged to intersect the upper and lower walls of the slab, respectively, are provided at the upper and lower parts of the slab;
Vertical main bars arranged to intersect with the horizontal main bars at the upper and lower parts of the slab;
Reinforcing bars arranged on the horizontal main bars in the slab between the upper body and the lower wall and arranged in parallel with the vertical main bars; and
It includes shear reinforcing bars coupled to the reinforcing bars in the slab and arranged vertically on the slab,
The shear reinforcing bar,
A connecting ring portion connected to the reinforcing bar;
Vertical reinforcing bars connected to the connecting link portion; and
A reinforcing structure of a slab shear load vulnerable section of a piloti building, characterized in that it includes horizontal reinforcing bars connected to the vertical reinforcing bars and disposed adjacent to the horizontal main bars along the direction of the horizontal main bars at the lower part of the slab. In claim 1,
The connecting link part,
Ring reinforcing bars surrounding the reinforcing bars and arranged at an angle on a plane perpendicular to the center line of the reinforcing bars; and
A reinforcing structure in the slab shear load vulnerable section of a piloti building, characterized in that it includes a hanging reinforcing bar that is bent from the ring reinforcing bar and supported in contact with the bottom surface of the reinforcing bar. In claim 2,
A reinforcing structure for the slab shear load vulnerable section of a piloti building, characterized in that the vertical reinforcing bars and horizontal reinforcing bars are provided in a “┻” shape. In claim 2,
The vertical reinforcing bars and horizontal reinforcing bars are provided in a “┛” shape,
Other vertical reinforcing bars connected to the horizontal reinforcing bars and forming a “┗┛” shape together with the vertical reinforcing bars; and
A reinforcing structure in the slab shear load vulnerable section of a piloti building, characterized in that it further comprises a ring-shaped crossing reinforcing bar that secures the other vertical reinforcing bars to the vertical main bars. It is placed on the slab connected to the upper and lower walls, which are spaced apart from each other in the building and arranged vertically,
Horizontal main bars arranged to intersect the upper and lower walls of the slab, respectively, are provided at the upper and lower parts of the slab;
Vertical main bars arranged to intersect with the horizontal main bars at the upper and lower parts of the slab; and
It is arranged to cross the horizontal main bars in the slab between the upper body and the lower wall, and includes shear reinforcing bars reinforced from the top to the bottom of the slab,
The shear reinforcing bar,
a plurality of inclined bars arranged inclinedly from the top to the bottom of the slab;
A plurality of horizontal reinforcing bars connected to the inclined bars at the lower part of the slab and disposed adjacent to the horizontal main bars; and
A reinforcing structure in the slab shear load vulnerable section of a piloti building, comprising a connecting reinforcing bar that interconnects the plurality of inclined bars and a plurality of horizontal reinforcing bars. In claim 5,
The connection reinforcement is,
A “┗┛” shaped inclined connecting reinforcing bar that connects the plurality of inclined bars to each other and forms a ring shape at the upper end of the plurality of inclined bars to span the vertical main bar; and
It includes horizontal connecting reinforcing bars of a “┏┓” shape that interconnect the plurality of horizontal reinforcing bars,
A reinforcing structure for the slab shear load vulnerable section of a piloti building, characterized in that the inclined connecting reinforcing bars and horizontal connecting reinforcing bars are arranged at vertical intervals. In claim 6,
A reinforcing structure for the slab shear load vulnerable section of a piloti building, characterized in that a vertical reinforcement groove is provided between the horizontal reinforcing bars and the inclined connecting reinforcing bars to allow the vertical main bars to pass through. In claim 6,
The connection reinforcement is,
An inclined reinforcing bar connecting the plurality of inclined bars and a plurality of horizontal reinforcing bars to correspond to each other, and connecting one of the plurality of horizontal reinforcing bars located at a lower side of an upper end of one of the plurality of inclined bars; and
It includes a bent ring reinforcing bar connecting the inclined bar and the inclined reinforcing bar,
The bent ring rebar is disposed on the central part of the horizontal reinforcing bar,
A reinforcing structure for the slab shear load vulnerable section of a piloti building, characterized in that the inclined bars, horizontal reinforcing bars, and inclined reinforcing bars are provided in a shape projected into an isosceles triangle on the front. In claim 8,
A reinforcing structure for the slab shear load vulnerable section of a piloti building, characterized in that the inclined reinforcing bars and the inclined bars are provided in a shape projected into a right triangle shape on the side. A building characterized by a reinforcement structure for the section vulnerable to slab shear load of a piloti building according to claim 1 or claim 5.