JP2001073559A - Reinforcing joint for concrete structure and reinforcing structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a reinforcing joint for a concrete structure and reinforcing structure capable of effectively reinforcing the concrete structure in which a wall section is connected continuously to a load supporting section composed of a column or a beam. SOLUTION: In the reinforcing structure of the concrete structure C in which wall sections W are connected continuously to the load supporting section S of a column or a beam, an annular hoop 11 is formed at the end section of a fiber sheet 1 in which reinforcing fibers are oriented in at least the longitudinal direction, the reinforcing joint in which anchor members 2 are engaged with the hoop 11 is used, and the anchor members 2 are anchored to the wall sections W on both left-right sides adjacent to the load supporting section S while the fiber sheet 1 is cured with an impregnated adhesive resin so as to be continuously connected between a pair of left-right anchor members 2, 2 along the load supporting section S.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a reinforcing joint and a reinforcing structure for reinforcing an existing concrete structure, and more particularly, to a concrete structure in which a wall is connected to a load supporting portion comprising a column or a beam. TECHNICAL FIELD The present invention relates to a reinforcing joint and a reinforcing structure for a concrete structure in which an object is reinforced more effectively than a conventional method.

[0002]

2. Description of the Related Art As a method of reinforcing an existing concrete structure, a construction in which a fiber sheet made of carbon fiber or aramid fiber is applied as a fiber reinforced resin (FRP) to the concrete surface to increase the strength and toughness of the structure is carried out in Hyogo. It has been spreading rapidly after the earthquake caused by the prefecture southern earthquake. This reinforcing method can maximize the properties of FRP with excellent specific strength and specific stiffness for independent columns that can be rolled up with FRP around, and obtain the desired reinforcing effect. In a concrete structure where the walls are connected, the FRP cannot be rolled up in a self-closing manner around the entire circumference of the columns and beams, so that the FRP does not sufficiently exert the strength of the fiber when an external force is applied. Peeled off, and a sufficient reinforcing effect was not obtained.

[0003] Such a non-self-closing FR
In order to prevent the peeling of P, there is a method of holding the end of the FRP with an iron plate or an angle material, and fixing the iron plate or the angle material to concrete with an anchor member bolt. However, although this method seems to be strong, it may cause a large number of scratches on the concrete to be covered, so that the strength may be reduced as compared with the case of only bonding.

Therefore, it has been proposed to use carbon fibers bundled in a broom shape as a method of reinforcing a concrete structure in which a wall is connected to a column or a beam. In this method, a shaft portion of a broom-like carbon fiber is penetrated through a sleeve wall, and broom portions at both ends of the shaft portion are opened in a fan shape, and this is attached to an end portion of the sleeve wall.
Glued to the ends, providing self-contained concrete restraint around the entire circumference of columns and beams. Further, even when self-closing type concrete restraint is impossible, the shaft portion of the broom-like carbon fiber is deeply embedded and fixed in the sleeve wall concrete, thereby obtaining a reinforcing effect corresponding to the shaft portion.

However, when a force test is performed on the reinforcing structure using the broom-like carbon fiber described above, it is found that the broom portion of the broom-like carbon fiber peels off from the FRP, and the shaft portion forms the sharp corner of the coarse aggregate in the concrete. And breaks,
The desired reinforcing effect was not always obtained. This may be due to the poor work of attaching broom-shaped fibers at an angle that intersects the fiber direction of the underlying FRP, or the number of layers of PRF
It is understood that the adhesive strength is not enough to support the strength of the BRP with the broom-like carbon fiber and that the FRP bundled in a rod shape is brittle. Therefore, the broom-shaped carbon fiber cannot sufficiently reinforce a concrete structure in which the wall is connected to the pillar or the beam.

[0006]

SUMMARY OF THE INVENTION An object of the present invention is to reinforce a concrete structure capable of effectively reinforcing a concrete structure in which a wall is connected to a load supporting portion formed of a column or a beam. It is to provide a joint and a reinforcing structure.

[0007]

According to the present invention, there is provided a reinforcing joint for a concrete structure, wherein at least one longitudinal end of a fiber sheet in which reinforcing fibers are oriented in a longitudinal direction has an annular hoop; An anchor member is engaged with the hoop.

Since the annular hoop is formed at the end of the fiber sheet and the anchor member is engaged with the hoop, a strong connection to concrete is formed by the anchor member while the hoop is connected to the anchor member by the hoop. It is possible to form a strong bond with the fiber sheet. Therefore, by fixing the anchor member in the concrete and winding up the fiber sheet along the columns or beams, it is possible to effectively reinforce a concrete structure in which the walls are connected to the columns or beams.

In the above-mentioned reinforcing joint, it is preferable that a displacement joint is provided on the anchor member so that the tension can be deflected. The fiber sheet is preferably made of at least one reinforcing fiber selected from glass fiber, carbon fiber, and aramid fiber. The anchor member is preferably made of a metal material. Furthermore, if the tensile strength based on the anchor member and the fiber sheet is set so as to correspond to the tensile strength of the rebar specified in the JIS standard, it is easy for architects who have no knowledge of fiber reinforcement technology to easily perform reinforcement design. It is possible to do.

On the other hand, in order to achieve the above object, a reinforcing structure for a concrete structure according to the present invention is a reinforcing structure for a concrete structure in which a wall is connected to a load supporting portion comprising a column or a beam. An annular hoop is formed at least at the end of the fiber sheet oriented in the longitudinal direction, and a reinforcing joint in which an anchor member is engaged with the hoop is used. The anchor member is fixed, and the fiber sheet is cured with an impregnated adhesive resin so as to be continuous between the pair of left and right anchor members along the load supporting portion.

As described above, since the annular joint hoop is formed at the end of the fiber sheet and the reinforcing member in which the anchor member is engaged with the hoop is used, the wall portion is connected to the load supporting portion formed of the column or the beam. Such a concrete structure can be effectively reinforced.

In the above reinforcing structure, the anchor members are respectively penetrated through the left and right walls adjacent to the load supporting portion, and the fiber sheet is continuously formed between the pair of left and right anchor members along the exposed surfaces on both the front and back surfaces of the load supporting portion. It is preferable to cure with an impregnated adhesive resin so that a self-closing type restraining band is formed by the anchor member and the fiber sheet.

[0013] Anchor members are respectively penetrated through the left and right side walls adjacent to the load support portion, and the fiber sheet is impregnated so as to be continuous between the pair of left and right anchor members along the exposed surface on the front side of the load support portion. While curing with an adhesive resin, the back ends of the pair of left and right anchor members are connected to each other via a metal member, and a self-closing restraint band is formed by these anchor members, the fiber sheet, and the metal member. good.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The configuration of the present invention will be described below in detail with reference to the accompanying drawings.

FIG. 1 shows an example of a reinforcing structure for a concrete structure according to the present invention. In the embodiment of FIG. 1, an end portion of a fiber sheet 1 in which reinforcing fibers are oriented at least in a longitudinal direction in a reinforcing structure of a concrete structure C in which a wall portion W is connected to a load supporting portion S formed of a column or a beam. An annular hoop 11 is formed on the hoop 11, and the anchor member 2 is engaged with the hoop 11 using the reinforcing joint. 1 is hardened with an impregnated adhesive resin so as to be continuous between a pair of right and left anchor members 2 along the exposed surfaces on both sides of the load supporting portion S, and self-closing type restraint is performed by these anchor members 2 and the fiber sheet 1. Forming a band.

In the reinforcing structure as described above, the fiber sheet 1
An annular hoop 11 is formed at the end of the fiber sheet 1, and the fiber sheet 1 is rolled up using a reinforcing joint in which the anchor member 2 is engaged with the hoop 11, thereby forming a strong joint structure.
Moreover, the anchor member 2 penetrating the wall W with respect to the concrete structure C in which the wall W is connected to the load supporting portion S
And the fiber sheet 1 are connected in a ring to form a self-closing restraint band, so that the concrete structure C can be reinforced more effectively than before.

FIG. 2 shows a modification of the reinforcing structure for a concrete structure according to the present invention. In the embodiment of FIG.
An annular hoop 11 is formed at an end portion of a fiber sheet 1 in which reinforcing fibers are oriented at least in a longitudinal direction in a reinforcing structure of a concrete structure C in which a wall portion W is connected to a load supporting portion S formed of a column or a beam. Then, the anchor member 2 is penetrated through each of the left and right wall portions W adjacent to the load support portion S by using a reinforcing joint in which the anchor member 2 is engaged with the hoop 11, and the fiber sheet 1 is attached to the load support portion S. While being cured with the impregnating adhesive resin so as to be continuous between the pair of left and right anchor members 2 and 2 along the exposed surface on the front side, the back ends of the pair of left and right anchor members 2 and 2 are connected to the backup material 3 (metal Members), and these anchor members 2
, The fiber sheet 1 and the backup material 3 form a self-closing restraint band.

In the reinforcing structure as described above, the fiber sheet 1
An annular hoop 11 is formed at the end of the fiber sheet 1, and the fiber sheet 1 is rolled up using a reinforcing joint in which the anchor member 2 is engaged with the hoop 11, thereby forming a strong joint structure.
Moreover, the anchor member 2 penetrating the wall W with respect to the concrete structure C in which the wall W is connected to the load supporting portion S
The self-closing type restraining band is formed by annularly connecting the fiber sheet 1 and the backup material 3 to each other, so that the concrete structure C can be reinforced more effectively than before. The backup material 3 is particularly effective when the load supporting portion S is flush with the wall W at the exposed surface on the back side.

The backup material 3 does not necessarily need to straddle the pair of right and left anchor members 2. When the backup material 3 is discontinuous between the pair of left and right anchor members 2, 2, the self-closing type restraining band is not formed, but with the help of the restraining action of the wall portion W, a pseudo self-closing type restraining band is formed. A restraining action is obtained.

The reinforcing structure according to each of the above embodiments is
The present invention can be applied to both reinforcement against bending deformation of columns and reinforcement against shear deformation of beams. For these reinforcements, it is necessary to arrange a plurality of reinforcing joints at intervals in the length direction of the load supporting portion S. For example, in the case of shear reinforcement of a beam, it is often necessary to reinforce a specific location (for example, a section about 1 m close to a column) due to a design change of a load to be loaded. In such a case, the intended purpose can be achieved by arranging several self-closing or pseudo-self-closing type restraining bands including a reinforcing joint in parallel between the shear reinforcing bars in the stirrup direction.

In each of the above embodiments, since the anchor member 2 receives tension from both sides of the wall portion W, the anchor member 2 is in a fixed state while being not fixed to the wall portion W. More preferably, resin or mortar is injected into the gap between the anchor member 2 and the hole formed in the wall W to fix the anchor member 2 to the wall W. Note that the anchor member 2 does not necessarily have to penetrate the wall W,
The fixing may be performed in a state of being embedded in the wall portion W.

The winding structure of the fiber sheet 1 with respect to the load supporting portion S is not particularly limited, and can be variously changed. That is, as shown in FIGS. 3A and 3B, it is possible to continuously use the fiber sheet 1 provided with the hoop 11 for the winding portion, but as shown in FIGS. 3C and 3D. The fiber sheets 1a and 1b for winding may be overlapped and connected to the fiber sheet 1 provided with the hoop 11. Such a lap joint has been well studied by a winding method, and a sufficient tensile strength can be secured by selecting the type of sheet and the lapping margin so as to satisfy the standards specified by the method.

FIGS. 4 and 5 show an example of a reinforcing joint for a concrete structure according to the present invention.

The fiber sheet 1 includes at least a large number of reinforcing fibers oriented in the longitudinal direction, and an annular hoop 11 is formed by folding back its longitudinal end. The end of the fiber sheet 1 on the side opposite to the hoop 11 constitutes a winding portion for restraining a pillar or a beam, or is connected to another fiber sheet for winding. The fiber sheet 1 needs to have the tensile direction as the main direction of the reinforcing fiber in order to oppose the tensile load. However, in order to reduce the uneven distribution of the load in the hoop width direction and maintain the hoop shape, a tensile load is applied. Fibers crossing in the direction of the fiber carrying (usually crossing at 90 °)
If necessary, fiber reinforcement in other than the main direction, such as inserting a hoop and sewing the hoop and the sheet body together so that the hoop does not open and separate, can be performed. Further, a hoop may be formed by stacking several sheets.

As the reinforcing fibers of the fiber sheet 1, glass fibers, carbon fibers, aramid fibers, and the like having high tensile strength and tensile modulus can be used, and especially, aramid fibers having excellent impact resistance are preferable. is there. In the case of using carbon fiber, it is necessary to electrically insulate the contact with the metal or to use a metal anchor member 2 which is hardly rusted such as stainless steel in order to prevent corrosion of the metal due to local battery generation. is there.

The width of the fiber sheet 1 is preferably about 10 cm in a building for easy handling, but it may be further increased in a civil engineering structure or the like, and may be arbitrarily set in the range of 10 to 100 cm. The allowable load per 10 cm width of the fiber sheet 1 is preferably set in the range of 4 to 12 tons. Such a fiber sheet 1 can be narrowed in width from the winding portion to the hoop 11 to be equal to (1 time) to １ ／ times the width of the winding portion.

The fiber sheet 1 is cured with the impregnated adhesive resin in the construction state. Before the construction, the fiber sheet 1 needs at least the required length (10 to 2) at the end opposite to the hoop 11.
0 cm) must be left unimpregnated with the resin. The other parts may be impregnated with resin prior to construction or may be impregnated at construction. As the impregnated adhesive resin, a moisture-curable one-component epoxy resin, a room-temperature-curable two-component epoxy resin, a heat-curable epoxy resin, or a radical polymerization resin can be used.

A core metal 12 is inserted inside the hoop 11. Since a load of several centimeters is applied to the core metal 12 in the order of several centimeters in the event of an earthquake, it is not only possible to reduce the deformation of itself but also to cut the fiber by contacting the fiber sheet 1 at an acute angle. You have to avoid it. Therefore, the portion of the core metal 12 that comes into contact with the fibers should have a smooth curve, and if the rigidity is insufficient, measures such as using hardened steel are taken. The cross-sectional shape of the metal core 12 may be circular or elliptical.

A filler 13 is inserted into the hoop 11. The hoop 11 has a structure in which the wall thickness is gradually reduced in a spindle shape from the cored bar 12 toward the winding portion, and smoothes the load transmission to the fiber sheet 1 while securing the strength and rigidity of the cored bar 12 to the fiber. Of the joints, thereby increasing the reliability and durability of the reinforced joints. As the filler 13, the above-described impregnated adhesive resin for curing may be used, but a different material may be used. As the filler 13, the most reasonable one may be selected in combination of the shape, capacity and material of the reinforcing joint.

The hoop 11 configured as described above is required to have higher strength than the rolled portion of the fiber sheet 1, not to break when a predetermined tensile load is applied, and to have an elongation within a predetermined value. You.

The anchor member 2 is configured to support both ends of a rod-shaped load receiving member 21 that engages with the hoop 11 with arm portions 22 having a forked structure. The anchor member 2 receives the tensile load by the load receiving member 21 intersecting the longitudinal direction of the fiber sheet 1 and supports it at the center position of the load receiving member 21 through the arm portion 22 having a forked structure. ing.

An anchor member 2 including the load receiving member 21
As a constituent material, a metal material, particularly an iron-based material, is preferable because it is inexpensive but excellent in strength and toughness.
In the conventional method of penetrating the rod-shaped FRP by bundling the reinforcing fibers into concrete, there is a concern that the proof stress is reduced in a composite stress field in which the rod is twisted, bent, or pushed up by the aggregate. There is. On the other hand, in the case of materials such as rebar, elongation is guaranteed without decreasing the yield strength even after the material yields, and therefore, it is extremely suitable for this use. On the other hand, it is necessary to design the size and shape of the load receiving member 21 to be engaged with the hoop 11 so as to realize mechanical characteristics capable of maintaining sufficient strength and rigidity against a maximum load.

The hole to be drilled in the wall portion S at the time of reinforcement work is ideally perpendicular to the wall and is linear, but when reinforcing an existing concrete structure, it may be slightly bent or drilled from both sides. It may cause misalignment. Therefore, since it is required that the anchor member 2 can be inserted into the above-described non-linear hole, it is important that the anchor member 2 can be bent on site like a reinforcing bar.

As means for improving the ability to follow the hole of the wall S, a displaceable coupling joint that enables rotational displacement and swing displacement may be provided on the anchor member 2. Such a coupling allows deflection of tension while following a non-linear hole. The configuration of the coupling joint is not particularly limited as long as there is a guarantee that the strength and rigidity fall within predetermined ranges, and a hook-shaped or screw-type one can be appropriately selected. For example, in the case of a large-capacity reinforcing joint used in civil engineering, the anchor member 2 becomes thick and may not be easily bent. In addition, even when hardened steel or the like is used for the anchor member 2, bending is difficult. Therefore, in these situations, it is preferable to provide the anchor member 2 with a displaceable coupling joint.

FIG. 6 illustrates a reinforcing joint suitable for the reinforcing structure of FIG. As shown in FIG. 6, the reinforcing joint is configured such that a pair of left and right anchor members 2, 2 with which the fiber sheet 1 is engaged can be connected to each other via hook-shaped connecting joints 23, 23. For this reinforced joint,
While making the through hole formed in the wall portion S smaller, the anchor members 2 may be inserted from both sides of the through hole, and the connecting joints 23 may be connected inside the through hole.

FIG. 7 illustrates a reinforcing joint suitable for the reinforcing structure of FIG. As shown in FIG. 7, this reinforcing joint comprises an anchor member 2 engaged with a fiber sheet 1 and an anchor member 2a in which a nut 25 can be screwed into a bolt portion 24 engraved at the distal end thereof in a hook shape. Connecting joints 23, 23
Are configured so as to be freely connected to each other. In the case of this reinforcing joint, after anchoring the anchor member 2a to the above-mentioned backup material 3 by tightening the nut 25, the anchor member 2 is inserted from the front side of the through hole, and the connection joints 23, 23 are inserted inside the through hole. Just connect them.

In the present invention, it is preferable that the tensile strength of the reinforcing joint based on the anchor member 2 and the fiber sheet 1 is set so as to correspond to the tensile strength of the rebar specified by the JIS standard. That is, the reinforcing bars belonging to the JIS-standard reinforcing bar group have a predetermined tensile strength based on their nominal size and material, but the tensile strength of the reinforcing joint of the present invention is made to correspond to the tensile strength of various reinforcing bars.

As described above, by making the tensile strength of the reinforcing joint correspond to the reinforcing steel strength of the JIS standard, it is possible to easily perform the reinforcing design even for the first and second grade architects who do not have the knowledge about the fiber reinforcing technology. Will be possible. However, the correspondence does not necessarily have to exactly match, and may include an allowable tolerance in design.

[0039]

As described above, according to the reinforcing joint for a concrete structure of the present invention, an annular hoop is formed at an end of a fiber sheet in which reinforcing fibers are oriented at least in the longitudinal direction, and an anchor is attached to the hoop. Since the members are engaged, it is possible to simply and effectively reinforce a concrete structure in which a wall is connected to a column or a beam.

Further, according to the reinforcing structure for a concrete structure of the present invention, when a concrete structure having a wall connected to a load supporting portion composed of a column or a beam is reinforced by a rolling method, An annular hoop was formed at the end of the fiber sheet in which the fibers were oriented at least in the longitudinal direction, and a reinforcing joint in which an anchor member was engaged with the hoop was used, so that the wall portion was connected to the column or beam. Concrete structures can be reinforced simply and effectively.

Further, if an anchor member, a fiber sheet, or a metal member forms a self-closing restraint band around the load supporting portion, the reinforcing effect can be further improved.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an example of a reinforcing structure for a concrete structure according to the present invention.

FIG. 2 is a sectional view showing a modified example of the reinforcing structure of the concrete structure according to the present invention.

FIGS. 3A to 3D are cross-sectional views illustrating a winding structure according to the present invention.

FIG. 4 is a plan view showing an example of a reinforcing joint for a concrete structure according to the present invention.

FIG. 5 is a sectional view taken along the line XX of FIG. 4;

FIG. 6 is a plan view illustrating a reinforcing joint suitable for the reinforcing structure of FIG. 1;

FIG. 7 is a plan view illustrating a reinforcing joint suitable for the reinforcing structure of FIG. 2;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Fiber sheet 2 Anchor member 3 Backup material (metal member) 11 Hoop 12 Core 13 Filler 21 Load receiving material 22 Arm part 23 Connection joint C Concrete structure S Load support part W Wall part

Claims (8)

[Claims] 1. A reinforcing joint for a concrete structure in which an annular hoop is formed at an end of a fiber sheet in which reinforcing fibers are oriented at least in a longitudinal direction, and an anchor member is engaged with the hoop. 2. The reinforcing joint for a concrete structure according to claim 1, wherein a displacement joint is provided on the anchor member. 3. The reinforcing joint for a concrete structure according to claim 1, wherein said fiber sheet is made of at least one kind of reinforcing fiber selected from glass fiber, carbon fiber, and aramid fiber. 4. The reinforcing joint for a concrete structure according to claim 1, wherein the anchor member is made of a metal material. 5. The concrete structure according to claim 1, wherein a tensile strength based on the anchor member and the fiber sheet is made to correspond to a tensile strength of a reinforcing bar specified in JIS standards. Reinforced joint. 6. A reinforcing structure for a concrete structure in which a wall portion is connected to a load supporting portion formed of a column or a beam, and an annular hoop is formed at an end portion of a fiber sheet in which reinforcing fibers are oriented at least in a longitudinal direction. Then, using a reinforcing joint in which an anchor member is engaged with the hoop, the anchor members are respectively fixed to the left and right side walls adjacent to the load supporting portion, and the fiber sheet is moved along the load supporting portion. Reinforcing structure of concrete structure cured with impregnated adhesive resin so as to be continuous between a pair of left and right anchor members. 7. An anchor member penetrates each of left and right wall portions adjacent to the load support portion, and the fiber sheet is placed between a pair of left and right anchor members along exposed surfaces on both front and back surfaces of the load support portion. The reinforcing structure for a concrete structure according to claim 6, wherein the anchor member and the fiber sheet form a self-closing type restraining band by being cured with an impregnated adhesive resin so as to be continuous. 8. The anchor member is pierced through both left and right wall portions adjacent to the load supporting portion, and the fiber sheet is continuously provided between the pair of left and right anchor members along the exposed surface on the front side of the load supporting portion. While being cured with the impregnated adhesive resin, the back ends of the pair of left and right anchor members are connected to each other via a metal member, and a self-closing type restraint band is formed by these anchor members, the fiber sheet, and the metal member. The reinforcing structure for a concrete structure according to claim 6, which is formed.