JP3851643B2 - Shear force reinforcement method - Google Patents

Description

  The present invention relates to a method for reinforcing a shearing force of a face material or a plate material of an existing reinforced concrete structure (hereinafter, reinforced concrete may be referred to as “RC”) on which a shearing force acts.

In various facilities such as subways and water and sewage purification facilities designed and constructed prior to the Great Hanshin Earthquake, RC box culverts and the side walls and bottom slabs of RC buried underground structures that make up the structural frame It is clear from the results of various seismic diagnosis that the “RC structure” is sometimes lacking in shear strength against Level 2 seismic motion, and the need for quick seismic reinforcement was pointed out. ing.
These RC structures are mostly embedded in the ground due to functional characteristics, and when reinforcing after construction, the side walls and bottom slab of the structural frame cannot be reinforced from the outside. It must be reinforced only from the inside.

  Conventionally, as a method for reinforcing an RC structure, a thickening method in which main reinforcing bars and distribution reinforcing bars are arranged at predetermined positions inside the RC structure and concrete is placed has been employed. However, in this construction method, after reinforcement, the thickness of the side wall, bottom slab, etc. is increased, and the internal cross section of the frame is reduced, so that various inconveniences occur (for example, water and sewage) In the case of a purification facility, the water storage capacity and the processing capacity decrease, and in the case of a subway, the construction limit may not be satisfied, and the use may be disabled. Furthermore, in the conventional method, although the shear strength is improved, the bending strength is also increased by increasing the main reinforcing bars. Therefore, the ratio between the shear strength and the bending strength is to be shifted to 2 to 4 after reinforcement. But this was difficult to do.

Therefore, in order to solve the above problems, as a method of reinforcing the culvert, a slit is formed in a vertical direction at a predetermined interval from the inside of the outer wall of the culvert, and after inserting a predetermined steel plate into the slit, A method has been proposed in which a grout material is filled in a slit to integrate the steel plate and the outer wall. (For example, Patent Document 1)
Japanese Unexamined Patent Publication No. 2003-3556 (2nd page to 4th page, FIG. 2)

  However, in the reinforcing method, a predetermined steel plate is simply inserted into the slit, so that when the pulling force is generated in the steel plate, sufficient rigidity (the magnitude of the pulling resistance against the pulling force, hereinafter referred to as “pulling rigidity”). ") Could not be obtained.

  The present invention has been made to solve the above-described problems, and it is possible to ensure a predetermined pulling rigidity easily and reliably, and a method for reinforcing the shear force of an existing RC structure (hereinafter simply referred to as “removing method”). It is an object to provide a “shear force reinforcement method”.

In order to solve the above-mentioned problems, the invention of claim 1 is a method for reinforcing a shearing force of an existing RC face material or plate material in which a shearing force acts, and includes the following steps.
(1) A bottomed reinforcing member insertion hole for forming a reinforcing member insertion hole for installing a shear reinforcing member is drilled from one surface side to the other surface side of the existing RC face plate or plate material. Process.
(2) A shear reinforcing member comprising: a shear reinforcing bar; and each fixing member having a cross-sectional shape larger than that of the shear reinforcing bar provided at a distal end portion and a base end portion of the shear reinforcing bar. A step of inserting a shear reinforcement member into the insertion hole and injecting a filler into the reinforcement member insertion hole to embed the shear reinforcement member in the existing reinforced concrete face material or plate .
The installation of the shear reinforcement member is not particularly distinguished, such as installation by loose fitting of the shear reinforcement member or installation by fixing, and the installation method is not limited.

  Further, the invention of claim 2 is the shear force reinforcement method according to claim 1, wherein the fixing member at the tip of the shear reinforcement member has a thickness of 15% to 40% of the diameter of the shear reinforcement reinforcing bar, and is long. A hollow portion of a metal annular tubular member formed so that a length dimension is 100% to 250% of the diameter of the shear reinforcing reinforcing bar is inserted into a distal end portion of the shear reinforcing reinforcing bar, and a pressing force is applied to the annular tubular member. It is characterized by being joined to the shear reinforcing bar by applying plastic deformation and plastic deformation.

  Further, the invention of claim 3 is the shear force reinforcement method according to claim 1, wherein the fixing member at the tip of the shear reinforcement member has a width dimension of 150% to 250% of the diameter of the shear reinforcement bar, and a length. The nut member formed so that the size is 100% to 250% of the diameter of the shear reinforcing reinforcing bar is joined by being inserted into the tip of the shear reinforcing reinforcing bar with the filler interposed therebetween. It is characterized by.

  According to a fourth aspect of the present invention, in the shear force reinforcing method according to the first aspect, the fixing member at the tip of the shear reinforcing member has a thickness of 40% to 80% of the diameter of the shear reinforcing bar, and a width. A steel plate material having a size of 150% to 250% of the diameter of the shear reinforcing bar is joined by friction welding to the tip of the shear reinforcing bar.

  According to a fifth aspect of the present invention, there is provided the shear force reinforcing method according to any one of the first to fourth aspects, wherein the fixing member at the base end portion of the shear reinforcing member has a thickness dimension of the shear reinforcement. By friction welding the steel plate material formed so that the reinforcing bar diameter is 40% to 80% and the width dimension is 150% to 300% of the shear reinforcing reinforcing bar diameter to the base end portion of the shear reinforcing reinforcing bar. It is characterized by being joined.

  Furthermore, the invention of claim 6 is the shear force reinforcement method according to any one of claims 1 to 5, wherein the surface of the existing concrete structure or the plate is directed from one side to the other side. In forming the reinforcing member insertion hole for installing the shear reinforcing member, the hole diameter near the tip of the shear reinforcing member is about 120% to 200% of the hole diameter of the portion where the shear reinforcing bar is inserted. An enlarged hole portion is provided.

  Here, the member to be reinforced by the present invention is a member that requires shear reinforcement, and various existing RC face materials (walls, etc.) or plate materials (bottom plate, top plate, etc.) (hereinafter “RC”). It can be applied to a surface-forming plate material), and the type of on-site casting, precast concrete product, etc. is not limited regarding the construction object.

In addition, the shear reinforcement member is arranged so as to secure a predetermined covering concrete thickness from the inner end surface and the outer end surface in the thickness direction of the RC surface plate material, and to avoid pre-arranged main reinforcing bars and distributed reinforcing bars. Need to be done.
Further, the filler is injected in order to firmly integrate the shear reinforcing member and the concrete of the RC surface plate material, and it is preferable to use epoxy resin, cement-based milk, cement-based mortar, or the like. .

  As a blend of cement-based milk or cement-based mortar, after the material of these fillers is hardened, a minute gap is generated between the reinforcing member insertion hole and these filler materials due to drying shrinkage or self-shrinkage. Since it is considered that they are not integrated with the body, an inflating agent is mixed into these filling materials, and after the filling materials are cured, the RC structure and the shear reinforcement member are integrated as non-shrinkable materials. Is preferred. It is also preferable to use a plastic material for the filler so that the filler during injection does not flow out depending on the direction of the reinforcing member insertion hole.

  According to the present invention, since the shear reinforcement member and the RC surface plate material concrete are integrated via the filler, this occurs when an out-of-plane shear force is generated in the RC surface plate material. The shear reinforcing member and the RC surface plate material integrally resist the oblique tensile stress. Accordingly, it is possible to improve the shear strength of the existing RC surface plate material and shift the fracture mode due to an earthquake or the like from brittle fracture to tough fracture.

  In addition, according to the present invention, an increase in shear strength and toughness performance can be efficiently realized by directly embedding a shear reinforcement member in the wall without increasing the concrete thickness of the RC surface plate material. Since it can do, it can prevent that the inconvenience that the internal cross section of a housing reduces after reinforcement | strengthening arises. In addition, since there is no increase in main reinforcing bars, the out-of-plane shear strength can be improved without increasing the bending strength. An RC structure can be transferred to a bending predestructive type.

  Further, in the shear reinforcement member, since the fixing member having a larger cross-sectional shape than the shear reinforcement bar is provided at the base end portion and the distal end portion of the shear reinforcement bar, the fixing effect of the shear reinforcement member can be enhanced. At the same time, the shear resistance and the toughness can be improved more effectively by the tensile resistance of the shear reinforcing bar and the compressive stress generated in the concrete inside the fixing member.

  According to the shear force reinforcing method of the present invention, a predetermined pulling rigidity can be ensured easily and reliably.

  A preferred embodiment of the reinforcing method of the present invention will be described in detail with reference to the drawings. In the following, the case where the side walls of the existing RC structure embedded in the underground ground G are subjected to shear reinforcement will be described. In the following description, the same reference numerals are used for the same elements, and duplicate descriptions are omitted.

<First embodiment>
The reinforcing method according to the first embodiment is mainly configured by (1) a step of drilling a reinforcing member insertion hole and (2) a step of inserting a shear reinforcing member.

(1) Reinforcing member insertion hole drilling step This step is a step of performing a work of forming a reinforcing member insertion hole for installing a shear reinforcing member from the inside to the outside of the side wall of the existing RC structure.

  As shown in FIG. 1 (a), the reinforcing member insertion hole 10 is connected to the main reinforcing bar R1 and the reinforcing reinforcing bar R2 at the time of drilling based on the arrangement of the existing RC structure and the information of the nondestructive test. In order to prevent damage, the horizontal interval is arranged at the center of both the reinforcing bars R1 and the vertical interval is the same as that of the distribution reinforcing bar R2. As shown in FIG. 1 (b), the reinforcing member insertion hole 10 is perforated from the inner side (one side) of the side wall W to the outer side (the other side) in contact with the ground G and substantially perpendicular to the side wall W surface. In various directions, drilling means such as impact drills, rotary hammer drills, and core drills are used. The reinforcing member insertion hole 10 is provided with a slightly downward slope and a length dimension obtained by subtracting a predetermined thickness of covering concrete thickness on the other surface side, and the hole diameter is a shear reinforcing member 20 shown in FIG. The diameter of the ring head 22 (fixing member) attached to the tip of the head is assumed to have a slight allowance.

  The reason why the reinforcing member insertion hole 10 is formed with a slightly downward slope is to facilitate the discharge of the internal air when the filler is injected in the shear reinforcing member insertion step described later. As a result, the filler can be more completely filled.

Thereafter, the drilling diameter on the inner side of the side wall W using the punching means so that the peripheral edge of the plate head 23 (fixing member) attached to the base end (terminal) of the shear reinforcement member 20 is hooked. To widen. Note that the drilling depth of the widened portion 11 needs to be a value obtained by adding the covering concrete thickness to the thickness of the plate head 23.
Then, when the perforation of the widened portion 11 of the reinforcing member insertion hole 10 is completed, the concrete powder generated for the perforation in the hole is removed.

(2) Shear Reinforcement Member Insertion Step In this step, the shear reinforcement member 20 is inserted into the reinforcement member insertion hole 10 shown in FIGS. 2 (a) to 2 (d), and the filler 30 is inserted into the reinforcement member insertion hole 10. Is a process of injecting and integrating.

  The shear reinforcing member 20 includes a shear reinforcing bar 21, and a ring head 22 and a plate head 23 that are provided at the distal end and the base end of the shear reinforcing bar 21 and have a larger cross-sectional shape than the shear reinforcing bar 21. It is configured.

  For example, the ring head 22 is made of a metal material that is relatively easy to process, such as mild steel or an aluminum alloy. A cylindrical body having a shape of 100% to 250% is prepared. Cover this with the tip of the shear reinforcing bar 21 and crush it from the surroundings using a gripper that combines two half rings, or narrow down the cylindrical body used for the squeeze joint of the bar. In this manner, the cylindrical body can be plastically deformed and integrated with the shear reinforcing bar 21 so as to be easily manufactured. Alternatively, a threaded reinforcing bar is used as the shear reinforcing bar 21 and a lock nut is screwed into the tip, and a double nut is used to remove rattling between the shear reinforcing bar 21 and the lock nut, or an epoxy is formed in the gap inside the nut. The ring head 22 has a thickness of 150% to 250% of the diameter of the shear reinforcing reinforcing bar and a length of 100% to 250% of the diameter of the shear reinforcing reinforcing bar by any of the methods of injecting a filler such as resin. It can also be manufactured. Alternatively, a steel plate having a thickness of 40% to 80% of the diameter of the shear reinforcing bar 21 and a width of 150% to 250% of the diameter of the shear reinforcing bar 21 by a method similar to the fixing method of the plate head 23 described later. You may manufacture by the method of welding to the front-end | tip part of the shear reinforcement steel bar 21. FIG.

  Further, the plate head 23 generates frictional heat at a predetermined pressure on the rotating steel plate by pressing the rotated steel plate against the fixed shear reinforcing bar 21 using a friction welding machine, and It can manufacture simply by welding a plate made to the shear reinforcement bar 21. The plate head 23 is formed with a filler injection hole 24 in principle.

  Here, the combination of the ring head 22 and the plate head 23 at both ends can be freely selected in accordance with factors such as the reinforcing state of the side wall W to be reinforced, concrete strength, wall thickness, and the like.

  Next, an operation process in which the shear reinforcement member 20 is installed in the reinforcement member insertion hole 10 and integrated with the side wall W will be described. First, a shear reinforcement bar 21 having a ring head 22 at the distal end and a plate head 23 at the proximal end is inserted into the reinforcing member insertion hole 10 so that the ring head 22 is positioned on the ground G side (FIG. 2). (See (a) and FIG. 2 (b)). Since there is a gap between the inner surface of the shear reinforcing bar 21 and the surrounding reinforcing member insertion hole 10, a filler 30 made of epoxy resin, cement-based milk, cement-based mortar, or the like is pressed into the gap and the shear reinforcing member 20. The side wall W is integrated. As shown in FIG. 2 (c), the method prepares a cap 31 made of a cement-based material, and pushes the cap 31 into the hole opening of the widened portion 11 to seal the reinforcing member insertion hole 10. An injection tube 32 such as a vinyl tube is provided at the lower end of the cap 31 so as to penetrate the injection hole 24 of the plate head 23, and the injection tube 32 is inserted to the vicinity of the ring head 22. The upper end is provided with a discharge pipe 33 for venting air. Further, a sealing material is interposed around the cap 31 to prevent leakage when the filler 30 is press-fitted. Here, the number of unfilled portions of the injection tube 32 is reduced when the tip portion thereof is brought closer to the ring head 22 at the tip portion of the shear reinforcement member 20. By the above method, the injected filler 30 is hardened inside the reinforcing member insertion hole 10, and the shear reinforcing member 20 and the side wall W are integrated to complete reinforcement.

The RC structure reinforced by the reinforcing method of the present invention is directly reinforced by the shear reinforcement member 20 against the oblique crack c generated when the out-of-plane shearing force S acts as shown in FIG. It improves the shear strength.
That is, when an out-of-plane shear force S acts on the side wall W, an oblique crack c tends to occur. However, since a tensile force acts on the shear reinforcement member 20, the pull-out force ft on the ring head 22 and the plate head 23 at both ends. Works. For this reason, in the concrete inside the ring head 22 and the plate head 23 (hereinafter referred to as “internal concrete”), a supporting pressure acts on the internal concrete as a reaction force, and a field of compressive stress fc is formed. . That is, the inner concrete is subjected to lateral restraint, resulting in an increase in resistance to oblique tension. For this reason, the shear reinforcement member 20 having the ring head 22 and the plate head 23 at the ends increases the out-of-plane shear strength of the side wall W, and a compressive stress fc is generated in the internal concrete (a compressive stress field is formed). The toughness performance is also increased.

  In the present embodiment, the enlarged hole portion 12 may be provided around the ring head 22, and in that case, as shown in FIG. 4, the fixing effect and toughness performance of the ring head 22 are increased. That is, when a pulling force ft is applied to the ring head 22, it is possible to prevent the occurrence of adhesion slip between the inner wall of the hole and the filler 30, and the pulling rigidity can be increased. Further, the bearing force reaction force acting on the ring head 22 effectively acts on the inner concrete, and a field of a large compressive stress fc is formed, so that the restraining effect of the inner concrete is further increased and the toughness performance is increased.

Further, when the reinforcement according to the present embodiment is performed, since the ring head 22 and the plate head 23 exist, the fixing portion increases. In order to investigate this fixing effect, an example of a result of an experiment of pulling out a shear reinforcing bar 21 having a plate head 23 and a shear reinforcing bar (hereinafter referred to as “comparative example”) in which a semicircular hook is formed at an end portion. Is shown in FIGS. 5 (a) and 5 (b). FIG. 5A shows a plate head having a circular shape having a thickness of 9 mm and a diameter of 35 mm, in which a reinforcing member insertion hole having a diameter of 25 mm is drilled in the RC member using a deformed reinforcing bar (D16). The relationship between the tensile stress and the displacement of each shear reinforcement member when the shear reinforcement member having the above and a comparative example are inserted and filled with a filler and cured is obtained.
In FIG. 5B, similarly, a deformed reinforcing bar (D22) is used, and a reinforcing member insertion hole with a diameter of 32 mm is drilled in the RC member, and the reinforcing member insertion hole has a circular shape with a thickness of 16 mm and a diameter of 45 mm. The relationship between the tensile stress and the displacement of each shear reinforcement member was determined by inserting a shear reinforcement member having a plate head and a comparative example.

  According to this result, it is proved that the shear reinforcing bar having the plate head according to the present invention has a smaller displacement (higher extraction rigidity) than the comparative example, and has an excellent fixing effect. became.

<Second Embodiment>
The reinforcing method according to the second embodiment includes (1) a step of drilling a reinforcing member insertion hole, (2) a step of press-fitting a filler, and (3) a step of inserting a shear reinforcing member. It is configured as the main part.

(1) Reinforcing member insertion hole drilling step This step is the same as the reinforcing member insertion hole 10 drilling step described in the first embodiment, and a detailed description thereof will be omitted. Note that the hole diameter of the reinforcing member insertion hole 10 according to the present embodiment is a value that allows for a slight margin in the reinforcing bar diameter of the shear reinforcing bar 21 ′.

(2) Filler press-fitting step This step is a step of performing the work of press-fitting the filler 30 into the reinforcing member insertion hole 10 with the press-fitting machine M shown in FIG.

  As shown in FIG. 6A, after the perforation of the reinforcing member insertion hole 10 is completed, the filler 30 made of a cement cement mortar is press-fitted by the press-fitting machine M. Here, plastic cement-based mortar is a material composed of cement, a pozzolanic substance such as silica fume and quartz powder, a thickener and water, and has the property of not flowing down even if it is filled upward. Therefore, the filling material 30 can be filled without being limited to the direction of the reinforcing member insertion hole 10. The material of the filler 30 is not limited to this as long as it has similar characteristics.

(3) Shear reinforcement member insertion step This step includes inserting the shear reinforcement member 20 'into the reinforcement member insertion hole 10 filled with the filler 30 as shown in FIGS. 11 is a step of applying a trowel of the filler 30 to 11 and performing an operation of integrating the shear reinforcing member 20 ′ and the side wall W.

As shown in FIG. 7, the shear reinforcing member 20 ′ according to the present embodiment has a shear reinforcing bar 21 ′ having a sharpened portion 25 at its tip, and a friction welding A to the base end of the shear reinforcing bar 21 ′. It is comprised from the plate head 23 with which cross-sectional shape is larger than the said shear reinforcement bar 21 'provided. In addition, since the fixing method by the friction welding A of the base end part of shear reinforcement bar 21 'and the plate head 23 is the same as the method demonstrated in 1st embodiment, detailed description is abbreviate | omitted.
Here, the processing method of the sharpened portion 25 of the shear reinforcing member 20 ′ is not limited, for example, the tip portion of the shear reinforcing reinforcing bar 21 ′ is cut off at an acute angle or deformed by heating. By providing the sharpened portion 25 at the tip of the shear reinforcing bar 21 ′, it is possible to prevent air from being caught when the shear reinforcing member 20 ′ is inserted into the filler 30.

  Next, an operation process in which the shear reinforcement member 20 ′ is installed in the reinforcement member insertion hole 10 and integrated with the side wall W will be described. First, as shown in FIG. 6B, the sharpened portion 25 is located at the distal end, the shear reinforcing bar 21 ′ having the plate head 23 at the proximal end, and the sharpened portion 25 is located on the ground G side. The reinforcing member insertion hole 10 filled with the filler 30 is inserted. Then, as shown in FIG. 6C, the space 11a formed in the widened portion 11 outside the plate head 23 is filled by rubbing a filler 30 made of cement-based mortar with a trowel. When the filling is completed, the mold 26 is installed on the inner surface of the side wall W so as to close the widened portion 11 so that the filler 30 is not deformed due to its fluidity. In this case, when the reinforcing member insertion hole 10 faces downward, the filler material 30 is not deformed, so there is no need to install the mold 26. The material, shape, and installation method of the mold 26 are not limited as long as the filler 30 can be prevented from flowing out of the widened portion 11.

Next, the mechanism of shear reinforcement according to the present embodiment will be described with reference to FIG.
When an out-of-plane shear force acts on the side wall W, an oblique crack c tends to occur. Force ft acts. For this reason, the supporting pressure from the plate head 23 acts on the concrete inside the plate head 23, and the compressive stress fc acts on the concrete inside the side wall W. That is, the concrete inside the plate head 23 is subjected to lateral restraint, resulting in an increase in resistance to oblique tension. For this reason, reinforcement of the reinforcing bar with the plate head 23 at the end increases the out-of-plane shear strength of the side wall W, and also increases the toughness performance by forming the compressive stress fc in the internal concrete.
Even in the case where the reinforcement according to the present embodiment is performed, the extraction experiment performed in the first embodiment was performed in order to investigate the fixing effect, and the same results as in FIGS. 5A and 5B were obtained. Results were obtained.

  As described above, according to the reinforcing method of the present invention, the shear reinforcement member 20 is directly embedded in the RC surface plate material without increasing the concrete thickness of the existing RC surface plate material. Since the increase in shear strength and toughness performance can be realized efficiently, it is possible to prevent the occurrence of inconveniences such as the decrease in the internal cross section after reinforcement as in the conventional reinforced concrete thickening method. In addition, since the main reinforcing bars are not increased, the out-of-plane shear strength can be improved without increasing the bending strength. It is possible to move to the predestructive type.

  Further, the increase in the drilling hole diameter by the ring head 22 provided at the distal end portion of the shear reinforcing bar 21 in the shear reinforcing member 20 according to the first embodiment is 30% to that of the reinforcing bar diameter of the shear reinforcing bar 21. Since it is only about 50%, the construction of the reinforcing member insertion hole 10 is easy, and the reinforcement can be executed economically. In addition, it is possible to efficiently perform the construction of the reinforcing member insertion hole 10 and the processing of the fixing material while ensuring a predetermined pulling rigidity.

Further, the plate head 23 provided at the proximal end portion of the shear reinforcing bar 21 and the ring head 22 provided at the front end portion can obtain a sufficient fixing effect, and when an out-of-plane shear force is generated, the shear reinforcing bar is provided. Since a tensile force acts on the plate 21, a support pressure acts on the plate head 23 or the ring head 22 and the plate head 23, and a compressive stress field is formed in the internal concrete. The force is increased to provide effective shear reinforcement.
Furthermore, since the reinforcing member insertion hole 10 is blocked from the outside by the filler 30, it can be expected to suppress deterioration from the viewpoint of durability after reinforcement.

  In addition, according to the shearing force reinforcing method according to the second embodiment, the drilling diameter of the reinforcing member insertion hole 10 may be about 120% to 130% of the reinforcing bar diameter of the shear reinforcing bar 21 ′, and the working efficiency is good. The integration with the side wall W is completed simply by inserting the shear reinforcement member 20 ′ into the reinforcement member insertion hole 10 filled with the filler 30 and filling the space outside the plate head 23 with the filler 30. Compared with the method of injecting the filler 30 after inserting the shear reinforcement member 20, the workability is excellent.

The preferred embodiments of the present invention have been described above. However, the present invention is not limited to the above-described embodiments, and it goes without saying that the above-described constituent elements can be appropriately changed in design without departing from the spirit of the present invention.
In particular, the RC structure as a target of the reinforcing method of the present invention is not limited to the above-described embodiment, and may be a structure using culverts or the like.
In particular, the existing RC structure to be reinforced may be an RC structure, and there is no limitation on the type such as a cast-in-place reinforced concrete structure or a precast concrete structure. It is also applicable to.
In particular, the insertion interval and the number of insertions of the shear reinforcement member are not limited to the above embodiment, and can be determined as appropriate.

It is a figure which shows the reinforcement member insertion hole drilling process of the reinforcement method which concerns on 1st embodiment and 2nd embodiment, (a) is a front sectional view, (b) is a sectional side view. (A)-(d) is a sectional side view which shows the shear reinforcement bar insertion process of the reinforcement method which concerns on 1st embodiment. It is a sectional side view which shows the stress state at the time of a shear force acting on the wall to which the reinforcement method which concerns on 1st embodiment is applied. It is a sectional side view which shows the stress state at the time of a shear force acting on the wall to which the case where the enlarged hole part is provided in the circumference | surroundings of a ring head is applied in the reinforcement method which concerns on 1st embodiment. (A), (b) is a graph which shows the result of the drawing experiment of the shear reinforcement bar which has a plate head, and the shear reinforcement bar which formed the semicircle hook at the end. (A)-(c) is a side view which shows the shear reinforcement reinforcing bar insertion process of the reinforcement method which concerns on 2nd embodiment. It is a whole perspective view of the shear reinforcement member which concerns on 2nd embodiment. It is a sectional side view which shows the stress state at the time of a shear force acting on the wall to which the reinforcement method which concerns on 2nd embodiment is applied.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Reinforcing member insertion hole 11 Widened portion 12 Widened portion 20, 20 ′ Shear reinforcing member 21, 21 ′ Shear reinforcing bar 22 Ring head 23 Plate head 25 Sharp portion 30 Filler 31 Cap 32 Injection tube 33 Discharge tube c Diagonal crack fc Compressive stress ft Pull-out force G Ground R1 Main rebar R2 Power distribution rebar S Shear force W Side wall

Claims (6)

A method for reinforcing an existing reinforced concrete face material or plate material on which a shearing force acts, comprising the following steps.
(1) Drilling a reinforcing member insertion hole for forming a bottomed reinforcing member insertion hole for installing a shear reinforcing member from one side of the existing reinforced concrete face plate or plate to the other side Process.
(2) A shear reinforcing member comprising: a shear reinforcing bar; and each fixing member having a cross-sectional shape larger than that of the shear reinforcing bar provided at a distal end portion and a base end portion of the shear reinforcing bar. Insert it into the insertion hole,
A step of inserting a shear reinforcement member, injecting a filler into the reinforcement member insertion hole and embedding the shear reinforcement member in the existing reinforced concrete face material or plate . The fixing member at the tip of the shear reinforcing member is
A hollow portion of a metal annular tube formed so that a thickness dimension is 15% to 40% of the shear reinforcing bar diameter and a length dimension is 100% to 250% of the shear reinforcing bar diameter, Insert it through the tip of the shear reinforcing bar,
The shear force reinforcing method according to claim 1, wherein the annular cylindrical member is joined to the shear reinforcing bar by applying a pressing force to plastic deformation. The fixing member at the tip of the shear reinforcing member is
A nut member formed so that a width dimension is 150% to 250% of the diameter of the shear reinforcing bar and a length dimension is 100% to 250% of the diameter of the shear reinforcing bar;
The shear force reinforcing method according to claim 1, wherein the joining is performed by inserting the tip of the shear reinforcing steel bar with the filler interposed. The fixing member at the tip of the shear reinforcing member is
A steel plate material having a thickness dimension of 40% to 80% of the shear reinforcing bar diameter and a width dimension of 150% to 250% of the shear reinforcing bar diameter,
The shearing force reinforcing method according to claim 1, wherein the shearing reinforcing bar is joined by friction welding to a front end portion of the shear reinforcing bar. The fixing member at the base end of the shear reinforcement member is
A steel plate material having a thickness dimension of 40% to 80% of the shear reinforcing bar diameter and a width dimension of 150% to 300% of the shear reinforcing bar diameter,
The shear force reinforcing method according to any one of claims 1 to 4, wherein the shear strength reinforcing bar is joined to the base end portion of the shear reinforcing steel bar by friction welding.   In forming the reinforcing member insertion hole for installing the shear reinforcing member from one side of the existing concrete face plate or plate to the other side, the hole diameter near the tip of the shear reinforcing member 6. A method for reinforcing a shear force according to claim 1, further comprising providing a hole expanding portion having a diameter of about 120% to 200% of a hole diameter of a portion into which the shear reinforcing bar is inserted. .

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