JP2007332667A - Method of reinforcing toughness of reinforced concrete columnar structure using carbon fibers - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of reinforcing toughness that satisfies new earthquake resistance standards, wherein the method is implemented by reducing the usage of reinforcing fibers compared with a conventional method and curtailing costs by virtue of optimized winding intervals of a reinforcing member, and facilitates checking of introduction of cracking etc. into concrete even if a moderate-sized earthquake or the like occurs after implementation of the method. <P>SOLUTION: According to the method of reinforcing the toughness of a reinforced concrete columnar structure, the carbon fiber-containing reinforcing members 2 are wound on a toughness reinforcing zone of the reinforced concrete columnar structure 1, extending from each of upper and lower edges of the structure over a length 2D (D is representative of a columnar cross sectional height), at the predetermined winding intervals such that each winding interval (P) is equal to or larger than 5 cm and that a value P/D is set to 1/3 or less. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a reinforcing method using carbon fibers of a concrete column or a concrete columnar structure such as a bridge pier and a chimney, and more particularly to a reinforcing method for improving dust performance.

  Concrete pillars, or existing concrete structures such as bridge piers and chimneys, differ in strength depending on design standards at the time of construction, as well as decrease in proof stress due to deterioration over time. In the previous Great Hanshin-Awaji Earthquake, the new earthquake resistance standards were reviewed based on the experience that damage to buildings that met the standards of the new earthquake resistance design law enforced in 1981 was minor. Is also required to comply with the new seismic standards.

  In the case of an existing structure, if it is demolished and newly constructed, a structure satisfying the new earthquake resistance standard can be obtained, but it takes a long time to construct and the cost is great. Therefore, normally, seismic reinforcement work is carried out unless it has deteriorated significantly.

  As such seismic reinforcement work, a steel plate bonding method (reinforcing method in which a steel plate is wound around a column) is known. However, since the steel sheet has a large weight, the workability is inferior, and there is a problem in long-term durability such as generation of rust.

  On the other hand, from the viewpoint of light weight and long-term durability, a reinforcing method using a reinforcing material using reinforcing fibers is known. In reinforcement work using reinforcing fibers, first, after correcting the unevenness of the parts to be reinforced, a primer layer is formed if necessary, a reinforcing fiber sheet is attached, and a room temperature curable resin is impregnated and cured. Thus, it is converted into a fiber reinforced resin (FRP) plate on the repair / reinforcement surface and fixed to the surface. In addition, a method of attaching a pre-cured FRP plate is also known.

  Non-Patent Document 1 discloses the construction method and construction guidelines for the purpose of expanding and applying the seismic reinforcement method using carbon fiber sheets to railway elevated columns. There are three types of reinforcement methods: shear reinforcement for the purpose of improving the shear strength of the member, toughness reinforcement for the purpose of improving the toughness of the member, and bending reinforcement for the purpose of improving the bending strength of the member. It is divided.

  When performing seismic reinforcement with a carbon fiber sheet, it is common to combine shear reinforcement at the center of the column and toughness reinforcement at the upper and lower ends of the column (see FIG. 12). The reinforcing section of the shear reinforcement extends over the entire section of the column height L, while the toughening is performed in a section twice (2D) the column width D (column cross-section height) at the upper and lower ends of the column.

  FIG. 13 shows a state in which the concrete in the reinforced concrete column is agglomerated in the plastic hinge region. In a conventional reinforcing method in toughness reinforcement, reinforcement is generally performed so as to constrain and prevent the agglomerated concrete from escaping outside in the plastic hinge region. Therefore, even in the toughness reinforcement by winding the carbon fiber sheet, the reinforcing material is covered and reinforced with no gap.

  In addition, when a predetermined amount of FRP is pasted on the entire surface, in the past experimental example, the reinforcing fiber breaks due to the protrusion of the base reinforcing bar that becomes the plastic hinge region at the end, and the concrete structure may break brittlely. Are known. In particular, when the amount of reinforcement of FRP is small, breakage of the reinforcing fiber occurs remarkably.

  As described above, in order to achieve the dust performance satisfying the new earthquake resistance standard, it is necessary to stack an extremely large number of FRPs, which is not practical in terms of cost and has few examples of adoption.

  In addition, when constructed in this way, the concrete surface will be covered with a reinforcing fiberboard after construction. For example, if a medium-scale earthquake occurs, whether or not the concrete is cracked. Diagnosis is very difficult.

  In addition, when winding the entire surface with a carbon fiber sheet, adjustment processing for steps, protrusions, unevenness, etc. is indispensable for obtaining sufficient adhesion, making the process complicated, increasing costs, extending the construction period, etc. It is also the cause of.

  For example, FIG. 14 shows the ground processing when there is a large level difference, and it is necessary to repair the upper part of the level difference by cutting it off and filling the lower side with a mortar or the like so as to be continuous with the scraped surface. In addition, even for small steps due to differences in formwork, etc., after the scraping treatment, the carbon fiber sheet is arranged so that it adheres to the column surface by smoothing treatment using an epoxy-based putty etc. after the primer coating surface is cured by touch. It is said that it must be.

  In Patent Document 1 (Japanese Patent Laid-Open No. Sho 62-244777) and Patent Document 2 (Japanese Patent Laid-Open No. Sho 62-242558), as an earthquake-proof reinforcement method for existing concrete columns, high-strength long fiber strands are spirally wound. In addition, Patent Document 3 (Japanese Patent Laid-Open No. 2000-73586) discloses a sleeve wall of a portion where an FRP reinforcing tape is used to roll around the reinforcing tape even if there is an obstacle such as a sleeve wall. In addition, Patent Document 4 (Japanese Patent Application Laid-Open No. 2002-115403) similarly discloses a method in which a walled concrete column is reinforced in the longitudinal direction of the column. It has been proposed to form a plurality of through-holes and wind a bundle of reinforcing fiber strands around the outer periphery of the pillar through each through-hole. Confirmation of after construction if Re is also possible.

These construction methods described in Patent Documents 1 to 4 all examine the shear reinforcement of concrete structures, and do not mention any dust performance that satisfies the new earthquake resistance standards.
"Guidelines for Design and Construction of Seismic Reinforcement Methods for Railway Viaduct Columns Using Carbon Fiber Sheets" Third Edition, Railway Technical Research Institute, issued July 4, 2003 JP-A-62-244977 JP-A-62-242058 JP 2000-73586 A JP 2002-115403 A

  The object of the present invention is to achieve the dust performance satisfying the new earthquake resistance standard by optimizing the winding interval of the reinforcing material, with the same or less carbon fiber amount as the conventional sheet pasting method, and the cost of the ground treatment Another object of the present invention is to provide a toughness reinforcing method that reduces the period and facilitates confirmation of the introduction of cracks or the like into concrete even when a medium-scale earthquake or the like occurs after construction. Further, the present invention provides a reinforcing method for preventing brittle fracture of a concrete structure without breaking the reinforcing fiber even when it reaches the end.

  As a result of intensive studies to solve the above-mentioned problems, the present inventors used a carbon fiber that is excellent in environmental resistance as a reinforcing fiber and is stable over a long period of time. The present inventors have found that a reinforcing method can be provided that reduces the amount, prevents the end of the reinforcing bars from seeing in the entire section reinforcement by the conventional carbon fiber sheet, and facilitates confirmation of the introduction of cracks and the like.

  That is, according to the present invention, the carbon fiber-containing reinforcing material is wound from the end of the columnar structure to the toughness reinforcing section 2D (D indicates the height of the column cross section) or less from the upper and lower ends of the reinforced concrete columnar structure. The present invention relates to a method for reinforcing the toughness of a reinforced concrete columnar structure, characterized in that P is 5 cm or more, and is wound and reinforced with a predetermined interval so that P / D is 1/3 or less.

  According to the present invention, the reinforcing member can withstand a predetermined deformation performance with a small amount of reinforcing fibers by winding the carbon fibers at predetermined intervals and dispersing the stress applied to the concrete structure throughout the structure. In addition, it does not occur at the end of reinforcing bars seen in all-zone reinforcement with conventional carbon fiber sheets, and breakage of reinforcing fibers when the amount of reinforcement is small, greatly improving the dust performance of concrete structures be able to.

  In addition, by winding at a predetermined interval, even if there is a step or the like, a large amount of ground processing is not necessary, and cost can be reduced and construction period can be shortened.

In this invention, the term used regarding toughness reinforcement is based on the description of nonpatent literature 1. The shear margin is a ratio of the shear strength to the bending strength, and is represented by (V _u · a / M _u ). Here, V _u is the design reinforcement shear strength of the column member, a is the shear span, and M _u is the design reinforcement bending strength of the column member. The toughness factor μ is the critical displacement δ _limit that can hold the yield strength P _y (horizontal load when the specimen's axial tensile reinforcement yields), and the yield point displacement δ _y (the specimen's axial tensile reinforcement is This is the value divided by the horizontal displacement when yielding. Non-Patent Document 1 shows a design reinforcement toughness ratio μ of toughness reinforcement by a carbon fiber sheet, and an evaluation formula related to the shear margin.

The design shear strength V _u of the column member is the sum of the share V _{cd of the} concrete, the share V _sd of the shear reinforcement, and the share V _CFd of the carbon fiber sheet. If the reinforced concrete columns to be reinforced are the same, The design shear strength V _u increases or decreases depending on the share V _CFd of the carbon fiber sheet. Since the contribution to the bending strength of the carbon fiber sheet in the toughness reinforcement is smaller than the contribution to the shear strength, the shear margin changes depending on the amount of reinforcement of the carbon fiber sheet. Therefore, if the same carbon fiber sheet is used, the amount of carbon fiber used decreases as the shear margin decreases.

  In the toughness reinforcement method of winding the present invention with a gap, high toughness performance can be obtained with a small shear margin. Therefore, sufficient toughness reinforcement is possible even when designing with a low shear margin beforehand. It becomes. That is, the amount of carbon fiber used can be reduced. In particular, in the present invention, a reduction in the amount of carbon fiber can be expected when the design toughness rate is low.

  In the present invention, the carbon fiber-containing reinforcing material is wound around the toughness reinforcing section with a predetermined interval and is reinforced. That is, the reinforcing material is not wound around the entire toughness reinforcing section, but the portion where the reinforcing material is wound and the portion where the reinforcing material is not wound are alternated. As a result, the force applied to the member is moderately dispersed, and it is possible to prevent the reinforcing bars from protruding at the end. The conventional method for reinforcing all sections by winding a carbon fiber sheet was thought to have little effect on suppressing the start of buckling of the main reinforcing bars (for example, "Study on deformation performance of paper-reinforced carbon fiber reinforced piers" The concrete engineering annual papers, Vol.22, No.3,2000, p235-240), the effect of suppressing the protrusion (buckling) of the main rebar by the method of the present invention cannot be predicted at all. It is an effect. In the all-zone reinforcement by the conventional winding of the carbon fiber sheet, especially when the force is applied to the plastic hinge region of 1.5D or less from the base and the force is applied and the reinforcing bar protrudes, and there are few reinforcing members The protruding member cuts the reinforcing member, resulting in brittle fracture of the member. For this reason, even when the design toughness rate is low, a large amount of carbon fiber is necessary in consideration of safety.In the present invention, high toughness performance can be obtained with a small amount of reinforcement, and the reinforcing bars protrude from the end. As a result, it has an excellent effect of preventing brittle fracture.

  As a method of winding at a predetermined interval, as shown in FIG. 1, a method of winding in stripes in a direction perpendicular to the material axis direction of the RC pillar (hoop winding) (FIG. 1A), the material axis of the column There is a method of winding obliquely in the direction, and in the case of winding obliquely, a long reinforcing material can be used to wind spirally (spiral winding) ((b) in the figure). Even in the case of winding spirally at an angle, it is desirable that the start portion and the end portion are wound in a direction perpendicular to the material axis direction in order to facilitate fixing, as shown in FIG.

  In a reinforced concrete column, main bars arranged in the direction of the material axis and band bars arranged at predetermined intervals so as to surround the main bars are arranged. In the old building standards, it was stipulated that the streaks be arranged at a pitch of D / 2 or less. In the present invention, it is necessary to reinforce with a carbon fiber-containing reinforcing material in a band shape at a pitch narrower than that of the band. In the present invention, the reinforcing material is wound so that P / D is 1/3 or less. On the other hand, if the pitch P is too narrow, there is no difference from full-scale reinforcement, and the effect of the present invention cannot be obtained. Therefore, reinforcement is performed at a pitch of 5 cm or more.

  The relationship between the winding width W of the reinforcing member and the reinforcing pitch P is shown in FIG. The figure (a) shows the case where the width | variety of a reinforcement member corresponds with the winding width W, and has shown the example of the carbon fiber sheet | seat band here. FIG. 5B shows a case where the reinforcing member is reinforced with a reinforcing member having a narrower width than the winding width W of the reinforcing member, and here, a case where the reinforcing member is reinforced with a string-like member is shown. The winding width W of the carbon fiber-containing reinforcing material may be a width in which a gap is formed between the reinforcing members at the pitch P. For example, when the minimum pitch is 5 cm, the width may be narrower than that, for example, 3 cm. Here, in order to obtain a predetermined amount of reinforcement, it is necessary to increase the cross section of each stripe when the pitch is wide. For this reason, it is necessary to increase the winding width W or increase the cross-sectional height H (increase the number of layers). The width W and the height H may be determined so that the aspect ratio represented by W / H is 1 or more, preferably 1.5 or more when the cross-sectional height H is the winding width W. When a carbon fiber sheet band is used, it is desirable to use a band having a width of 1 cm to 10 cm and having a W / P of 1/2 or less depending on the width of the member. The winding width W is preferably in the range of 1 to 10 cm, and it is desirable to wind a predetermined number of turns so that W / P is ½ or less. Furthermore, it is more preferable to set the width W to 2 to 5 cm and a narrower pitch within the specified range of the present invention.

<Reinforcing material>
The carbon fiber-containing reinforcing material used in the present invention includes a carbon fiber sheet band oriented in one direction, strands in which carbon fiber filaments are converged, ropes and strings in which strands are twisted, and carbon fiber filaments. You can use braided braids.

  Braids used in the present invention (also called “strings”) are machine manufactured, and can be broadly divided into 8 strokes (Yatsuuchi), 16 strokes (Dukurokuuchi), hammering (Kongouuchi), and many others. being classified. Also, there are flat punching assembled into a flat shape and round punching assembled into a round shape. FIG. 3 shows a schematic view of the side surface of a braided braid. In particular, when braid is used, a very high toughness rate can be achieved with a small shear margin as shown in the examples described later.

Carbon fibers are used as the reinforcing fibers to be used, and glass fibers, aramid fibers, other organic fibers, and the like can be mixed and used within a range that does not cause any problem, and can be appropriately selected according to the application. As the carbon fiber to be used, for example, in the tensile test method of carbon fiber reinforced plastic according to JIS K7073, the high strength type is 2.45 × 10 ⁵ N / mm ² , and the middle elastic type is 4.40 × 10. ⁵ N / mm ^2, the high modulus type using a material having a tensile modulus of ^{6.40 × 10 5 N / mm 2} .

  Furthermore, in the present invention, a reinforcing material such as carbon fiber is impregnated with a thermosetting resin to obtain a reinforcing material. As the resin to be impregnated, a room temperature curable epoxy resin, a thermosetting epoxy resin, a thermosetting resin such as a polyester resin, a radical reaction resin such as methyl methacrylate, or the like can be used. In particular, it is preferable to use a room temperature curing type epoxy resin. For example, trade names “Bond E2500” series and “Bond E206” series manufactured by Konishi Corporation can be used.

<Reinforcing method>
In the present invention, the carbon fiber-containing reinforcing material is reinforced by winding it around a concrete structure such as a pillar at a predetermined interval. As shown in the toughness reinforcement design of Non-Patent Document 1, the amount of reinforcement is calculated from the yield seismic intensity of the structure and the equivalent natural period, and the design plastic ratio (design toughness ratio) is obtained. Designed on the safe side according to the toughness rate evaluation formula. In the conventional all-section reinforcement, even if the design toughness ratio may be relatively low, taking into account the breakage of the reinforcing fibers due to the protrusion of the reinforcing bars at the end, reinforcement is greater than the amount of reinforcement calculated from the evaluation formula However, in the present invention, the reinforcement amount calculated from the evaluation formula has an effect that is more than sufficient, and even a reinforcement amount smaller than the reinforcement amount calculated from the evaluation formula shows a high toughness reinforcement effect. As shown in the examples described later, in the present invention, a toughness ratio of 7 can be achieved with a shear margin of 2.2. Therefore, the amount of reinforcement can be reduced using this as a guide.

  In order to reinforce the column made of reinforced concrete, as described in Non-Patent Document 1, construction is performed from the upper and lower ends of the column to the 2D toughness reinforcing section. There is no problem even if it extends beyond the 2D toughness reinforcement section to reach the shear reinforcement section, but in order to perform shear reinforcement, the amount of toughening reinforcement is over-specification, which is useless. For example, when a carbon fiber sheet having a width of 3 cm is used and the width of the member is set as a winding width W and reinforced at a pitch of 10 cm, it is necessary to wind about 5 layers to achieve a toughness ratio of 10, but this is necessary. In order to achieve the shearing performance, when plating is performed at the same pitch, about 0.2 layers are obtained. That is, the amount of reinforcement is different by 25 times. However, also in the present invention, it is preferable to perform toughness reinforcement and shear reinforcement together, as in the past. The reinforcement method of the shear reinforcement section excluding the toughness reinforcement section is not particularly limited, and a conventional method can be applied. In particular, in order to disperse the stress throughout the column, it is preferable to apply a method of reinforcing the shear reinforcement portion with a space. For example, as shown in FIG. 4, toughness reinforcement sections are subjected to toughness reinforcement according to the method of the present invention, and in the shear reinforcement sections excluding the toughness reinforcement sections, the pitch is increased or the number of laminations is reduced. Thus, the amount of reinforcement can be reduced and shear reinforcement can be performed.

  Moreover, when the cross section of a pillar etc. is a rectangle, it is preferable to chamfer a corner | angular part and to form R shape. Furthermore, in order to maintain the aesthetics of the surface or to further improve the durability of the reinforcing member, finishing can be performed by applying a finishing mortar or spraying paint on the surface around which the reinforcing member is wound. Further, it is possible to reinforce the column while maintaining the external shape of the column by forming a shallow groove in the column of the winding portion, winding the groove so as to embed the reinforcing member, and embedding with a mortar or the like. In the present invention, since large-scale base processing such as step processing performed in the conventional sheet pasting method is not necessary, for a structure having such a step, the construction period and cost are increased accordingly. Can be reduced.

  In order to improve the adhesion between the reinforcing member and the concrete, it is preferable to apply a primer treatment to the reinforcing portion. As the primer, a thermosetting adhesive such as a room temperature curing type or a thermosetting type epoxy resin, a polyester resin, or the like can be preferably used as in the case of the resin impregnated into the reinforcing member. For example, primers such as “Bond E800” series manufactured by Konishi Co., Ltd. are preferable.

  EXAMPLES Hereinafter, although an Example is given and this invention is demonstrated concretely, this invention is not limited to these Examples. In the following examples, evaluation was performed by the following test methods in order to confirm the reinforcing effect.

<Test body>
As shown in FIG. 5, the test specimen is an RC pillar 11 having a stub portion 1200 mm × 1200 mm × 500 mm indicated by reference numeral 12 and a column portion 300 mm × 300 mm × 1000 mm (main bar 13: 12-D19, belt bar 14: 6φ @ 200). It was used. For the preparation of the test body, a steel formwork was used. After demolding in 7 days after placing the concrete, curing was performed indoors. The corner portion of this test body was chamfered with R = 20 mm and then reinforced with carbon fiber.

<Reinforcing member>
The carbon fiber used is Toray-made "Treka T700S-12K" (Tensile strength = 4900MPa, Tensile modulus = 230GPa, TEX = 800g / km). The thickness was 15 mm and the weight was 30 g / m. Also, the same carbon fiber was used for the band, and a linear band having a width of 30 mm and a weight of 30 g / m was produced.

  The braid and band thus produced were impregnated with an epoxy resin (trade name “Bond E2500” manufactured by Konishi Co., Ltd.) to produce a reinforcing member. The physical properties of each produced reinforcing member are shown in Table 1 below.

<Load test>
A primer (trade name “Bond E810L” manufactured by Konishi Co., Ltd.) was applied to the entire reinforcing section of the test body, and the reinforcing member was wound around the stripe (hoop winding). The winding amount of the reinforcing member conforms to the Railway Technical Research Institute “Design and Construction Guidelines for Seismic Reinforcement of Railway Viaduct Columns Using Carbon Fiber Sheets” (design formula is μ = 2.8 + 1.15 × (Vu · a / Mu )) And decided. The loading test was conducted after the CF braid and the CF belt were applied and after curing for 7 days at room temperature. It shows in Table 2 about each combination.

The stub part is fixed to the reaction bed with a PC steel bar, and a vertical load with a constant axial force corresponding to a compressive stress of 1 N / mm ² is applied to the top of the test body. Repeatedly in the horizontal direction at a column height of 800 mm. Loaded.

  For the measurement, the load was measured with a load cell, and the displacement of each specimen was measured with a displacement meter. The measurement was carried out by applying a load until the specimen was broken or until the limit of deformation performance of the testing machine (15δ). Table 3 shows the behavior at the end of the test. Moreover, the load-displacement curve which shows the relationship between a displacement and a load is shown in FIGS.

  FIG. 11 shows the relationship between the shear margin and the maximum dust performance experimental value. In FIG. 11, the evaluation formula of the design reinforcement toughness rate of Non-Patent Document 1 is also shown. As is clear from FIG. 11, in the specimens (Nos. 2 to 4) using the CF band, a result almost equal to the maximum dust performance designed with the carbon fiber sheet was obtained. In the test body (No. 5) using braided CF, the result was much better than the maximum dust performance designed with the carbon fiber sheet. Further, in the test specimens (Nos. 2 to 5) to which the present invention was applied, no protrusion of the main reinforcing bar was observed at the end, and neither the CF reinforcing material nor the brittle fracture occurred. In any case, confirmation of the surface condition after the test was easy.

  The amount of carbon fiber required to satisfy the toughness rate of the experimental value is calculated from the specification evaluation formula as shown in the table below. From the result of No.4, when the maximum dust performance may be low, the effect of reducing the carbon fiber amount was confirmed. In the actual construction of the full-scale reinforcement by the carbon fiber sheet, in consideration of the sheet breakage due to the protruding of the reinforcing bar at the end, considering that more carbon fiber is used, in the method of the present invention Therefore, a reduction effect higher than this value can be expected. In addition, No. using braided CF. 5 also confirmed the effect of reducing the carbon fiber content.

It is a figure explaining the winding method of a reinforcement member, (a) shows a striped state, (b) shows the state wound spirally. It is a figure explaining the relationship between the winding width W of a reinforcement member, and the winding space | interval P, (a) shows the case where a strip | belt-shaped reinforcement member is used, (b) shows the case where a string-like reinforcement member is used. The schematic side view of a braided carbon fiber reinforcing member is shown. It is a figure which shows the reinforcement method which combined the toughness reinforcement method and shear reinforcement method by this invention. It is a figure explaining the test body (concrete column) used in the Example. Specimen No. It is a graph which shows the load-displacement curve of 1 (at the time of unreinforced). Specimen No. 2 is a graph showing a load-displacement curve of 2 (band, 5 cm pitch). Specimen No. 3 is a graph showing a load-displacement curve of 3 (band, 10 cm pitch). Specimen No. 4 is a graph showing a load-displacement curve of 4 (band, 10 cm pitch). Specimen No. 5 is a graph showing a load-displacement curve of 5 (braid, 10 cm pitch). It is a graph which shows the relationship between a shear margin and a toughness rate. It is a figure explaining the toughness reinforcement area and the shear reinforcement area of a column member. It is a figure explaining the destruction situation at the time of the end of RC pillar. It is a figure explaining the ground treatment (step difference process) in a conventional construction method (sheet construction method).

Explanation of symbols

DESCRIPTION OF SYMBOLS 1, 11 Reinforced concrete (RC) pillar 2 Reinforcement member 12 Stub 13 Main reinforcement 14 Band reinforcement P Pitch W Winding width H Winding height

Claims (3)

  The carbon fiber-containing reinforcing material is wound from the end of the columnar structure to the toughness reinforcing section below 2D (D indicates the height of the column cross section) from the upper and lower ends of the reinforced concrete columnar structure. A method for reinforcing the toughness of a reinforced concrete columnar structure, wherein the reinforcement is wound and reinforced with a predetermined interval so that P / D is 1/3 or less.   As the carbon fiber-containing reinforcing material, a carbon fiber sheet band in which carbon fibers having a width (W) in the range of 1 cm to 10 cm and W / P of 1/2 or less are oriented in one direction is used. The method for reinforcing toughness of a reinforced concrete columnar structure according to claim 1, wherein a desired number is wound by a width.   As the carbon fiber-containing reinforcing material, a braided carbon fiber-containing reinforcing material is used, and a predetermined number of turns are wound so that the width (W) is within a range of 1 cm to 10 cm, and W / P is ½ or less. The method for reinforcing toughness of a reinforced concrete columnar structure according to claim 1, wherein the toughness is wound.

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