JP3700980B1 - Shear force reinforcement method, shear force reinforcement structure, and shear reinforcement member - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a shear force reinforcing method, a shear force reinforcing structure and a shear reinforcing member of an existing RC structure capable of ensuring predetermined pulling rigidity easily and reliably.
A method for reinforcing a shear force of an intermediate wall W of an existing RC structure on which a shear force acts, characterized in that it includes the following steps.
(1) A step of drilling a reinforcing member insertion hole 10 for installing the shear reinforcing member 20 penetrating the intermediate wall W of the existing RC structure.
(2) A step of filling the reinforcing member insertion hole 10 with the filler 30.
(3) The shear reinforcing bar 21 and the base plate head 23 provided at the base end thereof are inserted into the reinforcing member insertion hole 10, and the tip plate head 22 is fixed to the tip of the shear reinforcing bar 21. And the process of arrange | positioning the shear reinforcement member 20 inside the intermediate wall W. FIG.
[Selection] Figure 2

Description

  The present invention relates to a shear force reinforcing method, a shear force reinforcing structure, and a shear reinforcing member for an existing reinforced concrete structure (hereinafter, reinforced concrete may be referred to as “RC”) on which a shear force acts.

  In various facilities such as subways and water and sewage purification facilities designed and constructed before the Great Hanshin Earthquake, RC box culverts and intermediate walls and underground slabs of RC underground structures that make up the structural frame, Many bridge piers (hereinafter sometimes referred to as “RC structures”) are often not equipped with shear reinforcement, and there is a lack of shear strength against Level 2 seismic motion. From this result, it is clarified that the need for immediate seismic reinforcement is pointed out.

  Conventionally, as a reinforcing method of these RC structures, a thickening method in which main reinforcing bars and distribution reinforcing bars are arranged along the surface of the RC structure and concrete is placed, or a steel plate is provided around the RC structure. A steel plate winding method or the like in which a gap between the RC structure and the steel plate is filled with a filler such as mortar or resin has been adopted.

  However, these methods cause various inconveniences such as an increase in the thickness of the face material and the plate material after reinforcement and a decrease in the internal cross section of the frame (for example, in the case of a water and sewage purification facility). In some cases, water storage capacity and processing capacity decrease, and in the case of a subway, the construction limit will not be satisfied, and it may become unusable. Furthermore, the thickening method increases the main reinforcement, so that the shear strength is improved, while the bending strength is also increased, so that the ratio between the shear strength and the bending strength is changed to 2 to 4 after reinforcement. It was difficult to realize.

  In addition, large-scale lifting machines are required to carry in and assemble reinforcing members such as reinforcing steel bars and steel plates, and in the limited space such as underground structures and bridges, there are restrictions on these lifting machines. It was sometimes difficult. In addition, in the case of shear reinforcement of intermediate walls in road tunnels and railway tunnels in service, due to the traffic volume and restrictions on train operation, the above-mentioned conventional construction is required to meet the demand for rapid construction within a limited time zone at night. In some reinforcement methods, construction could not be performed.

Therefore, in order to solve the above problems, as a method for reinforcing the shear force of the box culvert, slits are formed in the vertical direction at predetermined intervals from the inside of the outer wall of the box culvert, and a predetermined steel plate is inserted into the slit. Later, a method has been proposed in which a grout material is filled in the slit to integrate the steel plate and the outer wall. (For example, Patent Document 1)
Japanese Patent Laying-Open No. 2003-3556 (page 2 to page 4, FIG. 2)

  However, in the above reinforcing method, since a predetermined steel plate is simply inserted into the slit, when a pulling force is generated in the steel plate, sufficient rigidity (the magnitude of the pulling resistance with respect to 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 reinforcing structure and a shear reinforcing member.

In order to solve the above-mentioned problem, the invention described in claim 1 is a method for reinforcing a shear force of an existing reinforced concrete structure in which a shear force acts, and includes the following steps.
(1) A step of drilling a reinforcing member insertion hole for installing a shear reinforcing member that penetrates the reinforced concrete structure.
(2) A step of filling the reinforcing member insertion hole with a filler.
(3) Insert a wire and a proximal-side fixing member having a larger cross-sectional shape than the wire provided at the proximal end of the wire from one side of the reinforced concrete structure into the reinforcing member insertion hole, The tip part of the wire is fixed to the front-side fixing member having a larger cross-sectional shape than the wire inserted from the other surface side of the reinforced concrete structure, and a shear reinforcement member is installed in the reinforced concrete structure to provide the existing reinforced concrete structure. The process of arranging the concrete with the same thickness as the main reinforcing bar of the object .

The invention described in claim 2 is a method for reinforcing a shearing force of an existing reinforced concrete structure in which a shearing force acts, and includes the following steps.
(1) A step of drilling a reinforcing member insertion hole for installing a shear reinforcing member that penetrates the reinforced concrete structure.
(2) A step of inserting a wire and a proximal-side fixing member having a larger cross-sectional shape than the wire provided in the proximal end portion of the wire into the reinforcing member insertion hole from one surface side of the reinforced concrete structure .
(3) from said other side of the reinforced concrete structures, by inserting the cross-sectional shape is larger tip side fixing member from said wire, the wire tip in the reinforced concrete structure is fixed to section, the shear reinforcement member the existing The process of arranging in the state which secured the covering concrete thickness equivalent to the main reinforcement of the reinforced concrete structure .
(4) A step of filling the reinforcing member insertion hole with a filler.

The invention described in claim 3 is a method for reinforcing a shearing force of an existing reinforced concrete structure in which a shearing force acts, and includes the following steps.
(1) A step of drilling a reinforcing member insertion hole for installing a shear reinforcing member that penetrates the reinforced concrete structure.
(2) A step of inserting a wire and a proximal-side fixing member having a larger cross-sectional shape than the wire provided in the proximal end portion of the wire into the reinforcing member insertion hole from one surface side of the reinforced concrete structure .
(3) A step of filling the reinforcing member insertion hole with a filler.
(4) from said other side of the reinforced concrete structures, by inserting the cross-sectional shape is larger tip side fixing member from said wire, the wire tip in the reinforced concrete structure is fixed to section, the shear reinforcement member the existing The process of arranging in the state which secured the covering concrete thickness equivalent to the main reinforcement of the reinforced concrete structure .

  The invention according to claim 4 is the shear force reinforcing method according to any one of claims 1 to 3, wherein the step of drilling the reinforcing member insertion hole is based on the diameter of the wire. A step of drilling a general portion having an inner diameter smaller than the width dimension of the proximal-side fixing member and the distal-end-side fixing member, and a base end portion of the reinforcing member insertion hole. A step of perforating a widened portion having an inner diameter larger than the width dimension of the end-side fixing member; and a perforation of a widened portion having an inner diameter larger than the width dimension of the front-end-side fixing member formed at the distal end portion of the reinforcing member insertion hole. And a step of performing.

Further, the invention according to claim 5 is an existing reinforced concrete structure, a shear reinforcement member disposed inside a reinforcement member insertion hole formed so as to penetrate the reinforced concrete structure, and the reinforcement member insertion. A shear force reinforcing structure comprising a filler filled in a hole, wherein the shear reinforcing member is a wire, and a proximal fixing member and a distal fixing member each fixed to a proximal end and a distal end of the wire And both ends of the shear reinforcement member are arranged in a state in which a covering concrete thickness equivalent to the main reinforcement of the existing reinforced concrete structure is ensured, and the reinforcement member insertion hole has a diameter of the wire rod. Larger than the width dimension of the proximal fixing member and formed at the base end portion of the reinforcing member insertion hole and larger than the width dimension of the proximal fixing member. It is characterized in that it is composed of a widened portion of the diameter.

  The invention according to claim 6 is the shear force reinforcing structure according to claim 5, wherein the distal end portion of the reinforcing member insertion hole has an inner diameter larger than the general portion of the reinforcing member insertion hole. A widened portion is formed.

According to the seventh aspect of the present invention, both ends of a reinforcing member insertion hole formed so as to penetrate an existing reinforced concrete structure have a covering concrete thickness equivalent to the main reinforcing bar of the existing reinforced concrete structure. A shear reinforcement member disposed in a state where the wire has a length shorter than the extension of the reinforcement member insertion hole, a width dimension larger than the diameter of the wire, and a proximal end portion of the wire, A proximal-side fixing member and a distal-side fixing member fixed to the distal end, respectively, and an air vent hole is formed in the proximal-side fixing member, and an injection hole is formed in the distal-side fixing member. It is a feature.

  The invention according to claim 8 is the shear reinforcement member according to claim 7, wherein a male screw member is integrally formed at the tip of the wire, and the tip-side fixing member is The steel plate has a circular or polygonal shape with a thickness dimension of 80% to 120% of the diameter of the wire and a width dimension of 200% to 300% of the diameter of the wire, A female screw is formed, and the male screw member of the wire rod is screwed into the female screw to be fixed to the tip end portion of the wire rod.

  The invention according to claim 9 is the shear reinforcing member according to claim 7, wherein the wire has a male screw processed at a tip thereof, and the tip-side fixing member has a thickness of The steel plate has a circular or polygonal shape with a dimension of 80% to 120% of the diameter of the wire and a width of 200% to 300% of the diameter of the wire. And is fixed to the tip of the wire by screwing the male screw of the wire into the female screw.

  The invention according to claim 10 is the shear reinforcing member according to claim 7, wherein the wire is made of screw reinforcing bars, and the distal end side fixing member has a thickness dimension of the wire. It consists of a steel plate having a circular or polygonal shape with a diameter of 80% to 120% and a width of 200% to 300% of the diameter of the wire, and a female screw is formed on the steel plate. The wire rod is screwed into the female screw and fixed to the tip of the wire rod.

  The invention according to claim 11 is the shear reinforcing member according to any one of claims 7 to 10, wherein the proximal-side fixing member has a thickness dimension of the diameter of the wire. A steel plate having a circular or polygonal shape having a width of 30% to 120% and a width of 200% to 300% of the diameter of the wire is fixed to the base end of the wire.

  Here, the member to be reinforced by the present invention is a member that requires shear reinforcement, and is a face material (an intermediate wall or a wall surface of a wall-type pier) of an existing reinforced concrete structure or a plate material (an intermediate slab, etc.) ) (Hereinafter referred to as “RC surface plate material”), and the type of on-site casting, precast concrete product, etc. is not limited regarding the construction object.

  Further, the shear reinforcement member needs to be arranged so as to secure a predetermined covering concrete thickness from the outer surface in the thickness direction of the RC surface plate material, and to avoid the main reinforcing bars and the distributed reinforcing bars that have been pre-arranged. is there.

  Furthermore, the filler is used 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 being filled 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, the proximal end portion and the distal end portion of the shear reinforcement reinforcing bar, which is a wire, are respectively provided on the proximal end fixing member and the distal end fixing member (hereinafter referred to as “proximal end side”) having a cross-sectional shape larger than that of the shear reinforcement reinforcement When there is no need to distinguish between the “fixing member” and the “tip-side fixing member”, it may be simply referred to as “fixing member”), so that the fixing effect of the shear reinforcement member can be enhanced and shear reinforcement Due to the tensile resistance of the reinforcing bars and the compressive stress generated in the concrete inside the fixing member, the shear strength and the toughness can be improved more effectively.
Here, the wire rod is not limited to a deformed bar or a round steel rod, and any wire rod such as a carbon wire, a steel rod, a PC steel strand, etc. can be applied. Further, in this specification, the “width dimension” of the fixing member is unified as a diagonal length when the shape of the fixing member is rectangular or polygonal, a diameter when it is circular, and a long side length when it is elliptical. To do.

  According to the shearing force reinforcing method, the shearing force reinforcing structure, and the shearing reinforcing member 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, a description will be given of a case where the intermediate wall of a box culvert that is an existing reinforced concrete structure embedded in the ground is subjected to shear reinforcement. In the following description, the same reference numerals are used for the same elements, and duplicate descriptions are omitted.

  Here, FIG. 1 is a figure which shows the reinforcement member insertion hole drilling process of the shear force reinforcement method which concerns on 1st Embodiment-3rd Embodiment, (a) is a sectional side view, (b) ) Is a front sectional view. Moreover, FIG. 2 is a front sectional view showing each step of the shear force reinforcing method according to the first embodiment, (a) is a filling material filling step, (b) is a reinforcing bar insertion step, (c). And (d) has shown the shear reinforcement member arrangement | positioning process. FIG. 3A is an exploded perspective view of the shear reinforcement member according to the first embodiment, and FIGS. 3B and 3C are exploded perspective views showing modifications of the shear reinforcement member. is there. FIG. 4 is a front sectional view showing a stress state when a shearing force is applied to the wall to which the reinforcing method according to the first embodiment is applied, and FIGS. 5A and 5B are both shown. It is a graph which shows the result of the drawing-out experiment of the shear reinforcement bar which has a plate head, and the shear reinforcement bar which formed the semicircle-shaped hook in the end. Moreover, FIG. 6 is a front sectional view showing each step of the shear force reinforcing method according to the second embodiment, wherein (a) is a reinforcing bar insertion step, (b) is a shear reinforcing member arranging step, (c) ) And (d) show the filler filling step. Furthermore, FIG. 7 is a front sectional view showing each step of the shear force reinforcing method according to the third embodiment, (a) is a reinforcing bar insertion step, (b) is a reinforcing bar insertion step, and (c). Indicates a filler filling step, and (d) indicates a shear reinforcing member arranging step. In the description, “left” and “right” are unified in the direction shown in FIG.

  A shear force reinforcing structure 1 according to the present invention is disposed inside an existing reinforced concrete intermediate wall W and a reinforcing member insertion hole 10 penetrating the intermediate wall W in a direction crossing the main reinforcing bar of the intermediate wall W. And a filler 30 filled in the reinforcing member insertion hole 10 (see FIGS. 2 (d), 6 (d) and 7 (d)).

The shear reinforcement member 20 includes a shear reinforcement bar 21 that is a wire, and a proximal plate head (proximal fixing member) 23 and a distal plate head (distal fixing member) 22 fixed to the proximal end portion and the distal end portion, respectively. It is configured.
Further, the reinforcing member insertion hole 10 is formed in the general portion 12 having an inner diameter larger than the reinforcing bar diameter of the shear reinforcing bar 21 and smaller than the width dimension of the proximal plate head 23 and the proximal end portion of the reinforcing member insertion hole 10. The widened portion 11 having an inner diameter larger than the width dimension of the proximal plate head 23 and the widened section 11 having an inner diameter larger than the width dimension of the distal plate head 22 formed at the distal end portion of the reinforcing member insertion hole 10. It is composed of

  Hereinafter, a construction method and a detailed configuration of the shear force reinforcing structure according to the present invention will be described.

<First Embodiment>
The reinforcing method according to the first embodiment (hereinafter sometimes simply referred to as “first embodiment”) includes (1) a reinforcing member insertion hole drilling step, (2) a filler filling step, and (3). Each step of the reinforcing reinforcing bar insertion step and (4) the shear reinforcement member arranging step is configured as a main part.

(1) Drilling step of reinforcing member insertion hole This step is a step of drilling a reinforcing member insertion hole for installing a shear reinforcing member that penetrates the intermediate 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 penetrates in a direction substantially perpendicular to the side surface of the intermediate wall W, such as an impact drill, a leg drill, a rotary hammer drill, and a core drill. Drilling is performed using a punching means. The hole diameter of the reinforcing member insertion hole 10 is a value that allows for a slight margin in the reinforcing bar diameter of the shear reinforcing bar 21 shown in FIG.

Thereafter, a proximal plate head (base-side fixing member) 23 attached to the proximal end portion (terminal portion) of the shear reinforcement member 20 and a distal plate head (tip-side fixing member) 22 attached to the distal end portion. Widening of the drilling diameter of the reinforcing member insertion hole 10 using the punching means (hereinafter, the portion where the drilling diameter has been widened is referred to as “the peripheral part is hooked in the hole” (see FIG. 2C). Widening portion 11 "). The drilling depth of the widened portion 11 needs to be a value obtained by adding the covering concrete thickness to the thicknesses of the distal end plate head 22 and the proximal end plate head 23, respectively. The diameter of the widened portion 11 is a value that allows for a slight allowance for the widths of the distal plate head 22 and the proximal plate head 23 (diameter in the case of a circle). Hereinafter, a portion of the reinforcing member insertion hole 10 where the diameter of the drilling hole is not widened is referred to as a general portion 12.
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) Filler Filling Step In this step, as shown in FIG. 2A, the filler 30 is filled with the press-fitting machine M into the general portion 12 of the reinforcing member insertion hole 10 drilled in the reinforcing member insertion hole drilling step. It is a process to do.

As shown in FIG. 2A, after the perforation of the reinforcing member insertion hole 10 is completed, the general part 12 is filled with a filler 30 made of a plastic cement mortar by the press-fitting machine M. Here, a plug 30a made of wood or plastic is installed at the right end portion of the general portion 12 of the reinforcing member insertion hole 10 to prevent the filler 30 from flowing out.
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. Since it is the material 30, it is possible to fill without being limited to the direction of the reinforcing member insertion hole. The material of the filler 30 is not limited to this as long as it has similar characteristics. Further, the filling of the filler 30 into the reinforcing member insertion hole 10 is not limited to the filling by the press-fitting machine M, but may be filled by a known method.

(3) Shear Reinforcement Reinforcing Bar Insertion Step As shown in FIG. 2 (b), this step includes a shear reinforcement reinforcing bar 21 in the reinforcing member insertion hole 10 in which the general portion 12 is filled with the filler 30 in the filler filling step, and This is a step of inserting a base plate head 23 having a larger cross-sectional shape than the shear reinforcing bar 21 provided at the base end of the shear reinforcing bar 21.

  The shear reinforcement bar 21 is inserted into the reinforcement member insertion hole 10 by shear reinforcement in which the proximal plate head 23 is fixed to the proximal end portion from the left opening portion where the plug 30a of the reinforcement member insertion hole 10 is not installed. The rebar 21 is inserted by inserting it until its tip abuts against the plug 30a. At this time, since the reinforcing member insertion hole 10 is formed with allowance for the reinforcing bar diameter of the shear reinforcing reinforcing bar 21, even if the filler 30 is filled in the general portion 12 of the reinforcing member inserting hole 10, shear reinforcement is performed. The rebar 21 can be inserted. In addition, when inserting the shear reinforcement bar 21 into the reinforcing member insertion hole 10, the insertion resistance of the filler is reduced by attaching a bullet rubber or plastic cap to the tip of the shear reinforcement bar 21. It is good also as a structure.

  Here, the shear reinforcing bar 21 according to the first embodiment is formed of a deformed bar as shown in FIG. 3A, and has a base plate at its base end (left end in FIG. 3A). The head 23 is fixed by friction welding A. Further, a male screw member 21a for joining a tip plate head 22 to be described later is fixed to the tip end portion (the right end portion in FIG. 3A) of the shear reinforcing bar 21 by friction welding A. Here, the deformed reinforcing bars are used as the shear reinforcing reinforcing bars (wires) 21. However, the wires 21 are not limited to the deformed reinforcing bars, and may be any one that exhibits a function as a linear reinforcing material. For example, a screw rebar, a steel bar, a PC steel strand, a carbon wire, etc. may be used.

  Further, as shown in FIG. 3A, the base plate head 23 has a thickness dimension of 30% to 120% of the reinforcing bar diameter of the shear reinforcing bar 21 and a width dimension of 200% of the reinforcing bar diameter of the shear reinforcing bar 21. It is configured by joining a steel plate having a square shape of ˜300% to the proximal end portion of the shear reinforcing bar 21.

In addition, the joining method of the proximal end plate head 23 to the shear reinforcement bar 21 is a steel plate that rotates by pressing the rotated steel plate against the fixed shear reinforcement bar 21 using a friction welding machine (not shown). Friction heat is generated at a predetermined pressure, and the steel plate is welded to the shear reinforcing bar 21 (friction welding A).
Here, the joining method of the base end plate head 23 and the shear reinforcing steel bar 21 is not limited to the friction welding A, and it is only necessary to be able to integrate such as gas pressure welding or arc welding welding. Further, the shape of the proximal plate head 23 is not limited to a quadrangle, and may be other polygons, circles, or ellipses.

(4) Shear reinforcement member placement step In this step, as shown in FIGS. 2 (c) and 2 (d), the tip plate head 22 having a larger cross-sectional shape than the shear reinforcement bar 21 is inserted from the right side of the reinforcement member insertion hole 10. Then, after fixing to the distal end portion of the shear reinforcing bar 21 inserted in the reinforcing member insertion hole 10 in the shear reinforcing bar insertion step, the space 11a in the widened portion 11 is filled with the filler 30 so that the intermediate wall W It is the process of arrange | positioning the shear reinforcement member 20 inside.

  The tip plate head 22 removes the plug 30a installed at the right end portion of the general portion 12 of the reinforcing member insertion hole 10, and the end plate head 22 has a postscript on the end surface of the general portion 12 (the bottom surface of the widened portion 11). It inserts from the right side of the reinforcing member insertion hole 10 so that the female screw 22a to be arranged is arranged. Then, the shear reinforcing bar 21 and the tip plate head 22 are fixed by screwing the tip of the shear reinforcing bar 21 into the female screw 22 a, and the shear reinforcing member 20 is formed inside the intermediate wall W.

  Then, the filler 11 made of cement-based mortar is rubbed into the space 11a formed in the widened portion 11 on the right side of the distal plate head 22 and the space 11a formed in the widened portion 11 on the left side of the proximal plate head 23 with a trowel. Fill. When the filling is completed, the mold frame 26 is installed on the surface of the intermediate wall W so as to close the widened portion 11 so that the filler 30 is not deformed due to its fluidity. The mold 26 is removed after the filler 30 is cured. In this case, when the reinforcing member insertion hole 10 is in the horizontal direction as in the first embodiment, there is a case where it is not necessary to install the mold 26 because the filler 30 is not deformed. Further, when the reinforcing member insertion hole 10 is vertically oriented or inclined, the formwork 26 may be installed only in the widened portion 11 on the lower side. 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. Since the inside of the reinforcing member insertion hole 10 is filled with the filler 30 in advance, the shear reinforcing member 20 is inserted into the reinforcing member insertion hole 10 without a gap by inserting the shear reinforcing member 20 and curing the filler. To be integrated with the intermediate wall W.

  Here, as shown in FIG. 3A, the tip plate head 22 according to the first embodiment has a thickness of 80% to 120% of the reinforcing bar diameter of the shear reinforcing bar 21 and a width dimension of the shear reinforcing bar 21. A female screw 22a is formed in the center of a square steel plate having a diameter of 200% to 300% of the diameter of the reinforcing bar, and the male screw member 21a of the shear reinforcing reinforcing bar 21 can be screwed into the female screw 22a. Yes. The shape of the tip plate head 22 is not limited to a quadrangle, and may be other polygonal shape, circular shape, or elliptical shape (including an oval shape or a shape obtained by cutting off a side portion of a circle). Further, the shape of the joint portion of the tip plate head 22 with the shear reinforcing bar 21 is not limited, and the tip of the shear reinforcing bar 21 is formed on the inner surface of the tip plate head 22 ′ shown in FIG. A configuration may be used in which a cylindrical member 22a ′ in which a female screw is formed in accordance with the shape is fixed. In this case, a nut can be used as the cylindrical member 22a '.

  Moreover, although the thing which joined the male screw member 21a to the front-end | tip of a deformed reinforcing bar by the friction welding A as the shear reinforcement reinforcing bar 21 was used, it is not limited to this, For example, it shows in FIG.3 (b) As shown in FIG. 3 (c), the shear reinforcing reinforcing bar 21 ′ may be formed by processing the male thread 21a ′ at the tip of the deformed reinforcing bar. Screw rebars may be used.

  Further, in the filling material filling step, instead of the plug 30a, the tip plate head 22 is disposed at the right end of the general portion 12 and a sealant is interposed around the tip plate head 22, so that the general portion 12 is provided. It is good also as a structure filled with the filler 30 after shielding the right end of these. Thus, in the shear reinforcing bar insertion step, the shear reinforcing member 21 is disposed inside the intermediate wall W by inserting the shear reinforcing bar 21 into the reinforcing bar insertion hole 10 and fixing the tip thereof to the tip plate head 22. It becomes possible to do.

  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 shearing force S acts on the intermediate wall W, an oblique crack c tends to occur. However, since a tensile force acts on the shear reinforcement member 20, the distal end plate head 22 and the proximal end plate head 23 at both ends. A pulling force ft acts on the. For this reason, the concrete (hereinafter referred to as “inner concrete”) inside the distal end plate head 22 and the proximal end plate head 23 is subjected to a supporting pressure on the inner concrete as a reaction force, and the field of the compressive stress fc is generated. It 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 intermediate wall W, and a compressive stress fc is generated in the internal concrete (the compressive stress field is increased). The toughness performance is increased by being formed).

  Further, when the reinforcement according to the present embodiment is performed, the fixing plate portion is increased because the distal end plate head 22 and the proximal end plate head 23 exist. In order to investigate this fixing effect, a result of conducting an experiment of pulling out a shear reinforcing bar 21 having a base plate head 23 and a shear reinforcing bar (hereinafter referred to as “comparative example”) in which a semicircular hook is formed at the end. An example is shown in FIGS. 5 (a) and 5 (b).

FIG. 5 (a) shows a reinforcing member insertion hole having a diameter of 25 mm in an RC member using a deformed reinforcing bar (D16), and a circular base end plate having a thickness of 9 mm and a diameter of 35 mm in the reinforcing member insertion hole. The relationship between the tensile stress and the displacement of each shear reinforcement member when the shear reinforcement member having the head and the 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 of each shear reinforcement member and the displacement of displacement is obtained by inserting a shear reinforcement member having a proximal plate head and a comparative example.

  According to this result, it is proved that the shear reinforcing steel bar having the proximal plate head according to the present invention has a smaller displacement (higher extraction rigidity) and a superior fixing effect as compared with the comparative example. is what happened.

<Second Embodiment>
The reinforcing method according to the second embodiment (hereinafter may be simply referred to as “second embodiment”) includes (1) a reinforcing member insertion hole drilling step, (2) a reinforcing reinforcing bar insertion step, and (3). Each step includes a shear reinforcement member arranging step and (4) a filler filling step.

(1) Reinforcing member insertion hole drilling step This step is the same as the reinforcing member insertion hole drilling step described in the first embodiment, and a detailed description thereof will be omitted.

(2) Shear Reinforcement Reinforcing Bar Insertion Step In this step, as shown in FIG. 6A, the reinforcing member insertion hole 10 penetrated through the intermediate wall W in the reinforcing member insertion hole perforating step is sheared reinforcing reinforcement 21 and shear reinforcement. This is a step of inserting a proximal end plate head 23 having a larger cross-sectional shape than the shear reinforcing reinforcing bar 21 provided at the proximal end portion of the reinforcing bar 21.

  The shear reinforcing bar 21 is inserted into the reinforcing member insertion hole 10 from the opening on the left side of the reinforcing member insertion hole 10 by inserting the shear reinforcing bar 21 having the base plate head 23 fixed to the base end thereof to the base plate. The insertion is performed until the head 23 comes into contact with the tip of the left widened portion 11.

  Here, the base plate head 23 is previously formed with an air vent hole 23a at the time of filling a filler 30 to be described later. In addition, since the other structure of the shear reinforcement bar 21 and the base end plate head 23 which concerns on 2nd Embodiment is the same as that of the structure shown in 1st Embodiment, detailed description is abbreviate | omitted.

(3) Shear Reinforcement Member Arrangement Step In this step, as shown in FIG. 6 (b), from the right side of the reinforcement member insertion hole 10, the tip plate head 22 having a larger cross-sectional shape than the shear reinforcement bar 21 is inserted, and shear reinforcement is performed. In this step, the shear reinforcement member 20 is disposed inside the intermediate wall W by being fixed to the tip of the shear reinforcement bar 21 inserted into the reinforcement member insertion hole 10 in the reinforcement insertion step.

  The tip plate head 22 is inserted from the right side of the reinforcing member insertion hole 10 so that the female screw 22a of the tip plate head 22 is disposed at the right end portion (bottom surface of the widened portion) of the general portion 12 of the reinforcing member insertion hole 10. . Then, the shear reinforcing bar 21 and the tip plate head 22 are fixed by screwing the tip of the shear reinforcing bar 21 into the female screw 22 a, and the shear reinforcing member 20 is formed inside the intermediate wall W. In addition, a sealing material 24 is interposed around the distal plate head 22 and the proximal plate head 23 to prevent the filler 30 from leaking when the filler 30 is injected in the filler filling step described later. .

  Here, in the tip plate head 22 according to the second embodiment, an injection hole 22b at the time of filling with a filler 30 to be described later is formed in advance. Further, since the other configuration of the tip plate head 22 is the same as the configuration shown in the first embodiment, detailed description thereof is omitted.

(4) Filler Filling Step This step is a step of filling the filler 30 into the reinforcing member insertion hole 10 in which the shear reinforcing member 20 is installed, as shown in FIGS. 6 (c) and 6 (d).

First, as shown in FIG. 6C, the injection tube 31 made of a vinyl tube or the like is inserted into the injection hole 22 b of the tip plate head 22 and penetrates to the general portion 12 of the reinforcing member insertion hole 10. Further, an air vent tube 32 made of a vinyl tube or the like penetrates through the air vent hole 23 a of the base plate head 23 to the general portion 12 of the reinforcing member insertion hole 10.
Then, the filler 30 is injected (filled) into the general portion 12 from the injection tube 31 using a known injection device. The filling material 30 is injected until the filling material 30 is discharged from the air vent pipe 32, and the gap between the general portion 12 and the shear reinforcing bar 21 is completely filled. Moreover, since the periphery of the general part 12 is shielded by the distal plate head 22 and the proximal plate head 23 interposed by the sealing material 24, the filler 30 does not leak.

  When the filling of the filling material 30 into the general portion 12 is completed, the space 11a formed in the widened portion 11 on the right side of the distal plate head 22 and the space 11a formed in the widened portion 11 on the left side of the proximal plate head 23 are cemented. The filler 30 made of mortar is filled by rubbing with a trowel. In addition, since the filling method of the filler 30 to the space 11a is the same as the method shown in 1st Embodiment, detailed description is abbreviate | omitted.

As a result, the filler 30 is cured, so that the shear reinforcement member 20 is fixed in the reinforcement member insertion hole 10 without a gap, and integration with the intermediate wall W becomes possible.
The shear reinforcement mechanism and the fixing effect according to the second embodiment are the same as the contents described in the first embodiment, and thus detailed description thereof is omitted.

<Third Embodiment>
The reinforcing method according to the third embodiment (hereinafter sometimes simply referred to as “third embodiment”) includes (1) a reinforcing member insertion hole drilling step, (2) a reinforcing reinforcing bar insertion step, and (3). Each step of the filler filling step and (4) the shear reinforcement member arranging step is configured as a main part.

(1) Reinforcing member insertion hole drilling step This step is the same as the reinforcing member insertion hole drilling step described in the first embodiment, and a detailed description thereof will be omitted.

(2) Shear Reinforcing Bar Insertion Step In this step, as shown in FIG. 7A, the reinforcing member insertion hole 10 penetrated through the intermediate wall W in the reinforcing member insertion hole drilling step and the shear reinforcing reinforcing bar 21 and the shear reinforcement. This is a step of inserting a base plate head 23 having a cross-sectional shape larger than that of the shear reinforcing bar 21 provided at the base end of the bar 21.

  The shear reinforcing bar 21 is inserted into the reinforcing member insertion hole 10 from the opening on the left side of the reinforcing member insertion hole 10 by inserting the shear reinforcing bar 21 having the base plate head 23 fixed to the base end thereof to the base plate. The insertion is performed until the head 23 comes into contact with the bottom surface of the left widened portion 11 (the left end portion of the general portion). A sealing material 24 is interposed around the base plate head 23 to prevent the filler 30 from leaking when the filler 30 is injected in a filler filling step described later.

  Here, the other configurations of the shear reinforcing bar 21 and the proximal plate head 23 according to the third embodiment are the same as the configurations shown in the first embodiment, and thus detailed description thereof is omitted.

(3) Filler Filling Step This step is a step of filling the filler 30 into the general portion 12 of the reinforcing member insertion hole 10 in which the shear reinforcing bar 21 is installed, as shown in FIG.

  First, as shown in FIG. 7B, the injection tube 31 made of a vinyl tube or the like is inserted from the right side opening of the general part 12 so that the tip thereof is disposed in the vicinity of the left base plate head 23. And the filler 30 is inject | poured from the general part 12 left side using a well-known injection | pouring apparatus from the injection tube 31. FIG. Here, the filling tube 31 is gradually pulled out to the right side as the filling material 30 is filled, while the tip of the filling tube 31 is always placed inside the filled material 30 until the filling of the general portion 12 is completed. Note that the left end of the general portion 12 is shielded by the base end plate head 23 interposed by the sealing material 24 so that the filler 30 does not leak.

(4) Shear reinforcement member placement step In this step, as shown in FIGS. 7C and 7D, the tip plate head 22 having a larger cross-sectional shape than the shear reinforcement bar 21 is inserted from the right side of the reinforcement member insertion hole 10. Then, after fixing to the distal end portion of the shear reinforcing bar 21 inserted into the reinforcing member insertion hole 10 in the shear reinforcing bar insertion step, the space 11a in the widened portion 11 is filled with the filler 30 so that the intermediate wall W It is the process of arrange | positioning the shear reinforcement member 20 inside.

In addition, since this process is the same as the shear reinforcement member arrangement | positioning process in 1st Embodiment, detailed description is abbreviate | omitted.
Further, the configuration of the tip plate head 22 according to the third embodiment is the same as the configuration shown in the first embodiment, and a detailed description thereof will be omitted.

As a result, the filler 30 is cured, so that the shear reinforcement member 20 is fixed in the reinforcement member insertion hole 10 without a gap, and integration with the intermediate wall W becomes possible.
The shear reinforcement mechanism and fixing effect according to the third embodiment are the same as the contents described in the first embodiment, and thus detailed description thereof is omitted.

  As described above, according to the shear force reinforcement method of the present invention, the RC surface plate material is subjected to the out-of-plane shear reinforcement, and the plate heads provided directly at both ends of the shear reinforcement bar and the shear reinforcement bar are RC. By forming inside the surface plate material, an increase in shear strength and toughness performance can be realized efficiently.

  In addition, since the shear force reinforcing method of the present invention is limited to the inside of the RC surface plate material, reduction of the building limit and reduction of the storage capacity capacity, etc., which are caused by the thickening method and the steel sheet winding method which are conventional methods, etc. It can be avoided.

  Moreover, since it is a reinforcement method corresponding to only shear reinforcement, only the out-of-plane shear strength is improved without improving the bending strength. For this reason, an RC structure having the possibility of a bending / shear predestructive type can be transferred to the bending predestructive type, which is also preferable from the viewpoint of seismic reinforcement.

In addition, according to the shear force reinforcing method according to each of the above embodiments, the drilling diameter of the general portion of the reinforcing member insertion hole 10 may be about 120% to 130% of the reinforcing bar diameter of the shear reinforcing reinforcing bars 21 and 21 ′, and the working efficiency is improved. Well, it is excellent in workability.
Moreover, the tip plate head fixed to the tip of the shear reinforcing bar can be easily attached, but the fixing degree is high and the effect of fixing the shear reinforcing bar can be sufficiently exhibited.
Further, 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, the proximal plate head 23 provided at the proximal end of the shear reinforcing bar 21 and the distal plate head 22 provided at the distal end can obtain a sufficient fixing effect and generate an out-of-plane shear force. Since a tensile force acts on the shear reinforcing reinforcing bar 21, a supporting pressure acts on the tip plate 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.

  Further, in the shear force reinforcing method according to the first embodiment, after filling the plastic cement-based mortar, the shear reinforcing member is arranged to fill the space outside each plate head fixed to both ends of the shear reinforcing member. Since the construction is completed simply by rubbing the material with a trowel, the construction period can be shortened compared to the conventional thickening method and steel sheet winding method, which is economically superior.

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 that is the object of the reinforcing method of the present invention is not limited to the above-described embodiment, and may be a wall-type abutment of a bridge.

In addition, 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, and the part to be reinforced is not limited. The present invention can also be applied.
Further, 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.

Moreover, in each said embodiment, although it was set as the structure which inserts a shear reinforcement bar from the left side of an intermediate wall, it cannot be overemphasized that the insertion direction is not limited.
In addition, the base plate head of each of the above embodiments has a configuration in which a rectangular steel plate is fixed to the shear reinforcement bar by friction welding, but is not limited thereto, for example, the base plate head By configuring the female thread, the base end of the shear reinforcing bar is processed with a male screw in the same way as the tip, and the shear reinforcing bar is screwed into the base plate head. The reinforcing bar may be screwed into the proximal plate head.

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 sectional side view, (b) is a front sectional view. It is front sectional drawing which shows each process of the shear force reinforcement method which concerns on 1st Embodiment, (a) is a filler filling process, (b) is a reinforcement reinforcement insertion process, (c) and (d) are shearing. The reinforcement member arrangement | positioning process is shown. (A) is a disassembled perspective view of the shear reinforcement member which concerns on 1st Embodiment, (b) And (c) is an exploded perspective view which shows the modification of a shear reinforcement member. It is a front sectional view showing a stress state when a shearing force is applied to a wall to which the reinforcing method according to the first embodiment is applied. (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. It is a front sectional view showing each process of the shear force reinforcement method concerning a 2nd embodiment, (a) is a reinforcement reinforcing bar insertion process, (b) is a shear reinforcement member arrangement process, (c) and (d) are The filling material filling process is shown. It is a front sectional view showing each process of the shear force reinforcement method concerning a 3rd embodiment, (a) is a reinforcement reinforcing bar insertion process, (b) is a reinforcement reinforcing bar insertion process, (c) is a filler filling process, (D) has shown the shear reinforcement member arrangement | positioning process.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Shear force reinforcement structure 10 Reinforcement member insertion hole 11 Widening part 20,20 ', 20 "Shear reinforcement member 21,21', 21" Shear reinforcement reinforcement (wire)
22 Lead plate head (tip fixing member)
23 Base plate head (base side fixing member)
30 Filler c Diagonal crack fc Compressive stress ft Pull-out force G Ground R1 Main rebar R2 Power distribution rebar S Shear force W Middle wall (reinforced concrete structure)

Claims (11)

A method for reinforcing an existing reinforced concrete structure on which a shearing force acts, comprising the following steps.
(1) A step of drilling a reinforcing member insertion hole for installing a shear reinforcing member that penetrates the reinforced concrete structure.
(2) A step of filling the reinforcing member insertion hole with a filler.
(3) Insert a wire and a proximal-side fixing member having a larger cross-sectional shape than the wire provided at the proximal end of the wire from one side of the reinforced concrete structure into the reinforcing member insertion hole, The tip part of the wire is fixed to the front-side fixing member having a larger cross-sectional shape than the wire inserted from the other surface side of the reinforced concrete structure, and a shear reinforcement member is installed in the reinforced concrete structure to provide the existing reinforced concrete structure. The process of arranging the concrete with the same thickness as the main reinforcing bar of the object . A method for reinforcing an existing reinforced concrete structure on which a shearing force acts, comprising the following steps.
(1) A step of drilling a reinforcing member insertion hole for installing a shear reinforcing member that penetrates the reinforced concrete structure.
(2) A step of inserting a wire and a proximal-side fixing member having a larger cross-sectional shape than the wire provided in the proximal end portion of the wire into the reinforcing member insertion hole from one surface side of the reinforced concrete structure .
(3) from said other side of the reinforced concrete structures, by inserting the cross-sectional shape is larger tip side fixing member from said wire, the wire tip in the reinforced concrete structure is fixed to section, the shear reinforcement member the existing The process of arranging in the state which secured the covering concrete thickness equivalent to the main reinforcement of the reinforced concrete structure .
(4) A step of filling the reinforcing member insertion hole with a filler. A method for reinforcing an existing reinforced concrete structure on which a shearing force acts, comprising the following steps.
(1) A step of drilling a reinforcing member insertion hole for installing a shear reinforcing member that penetrates the reinforced concrete structure.
(2) A step of inserting a wire and a proximal-side fixing member having a larger cross-sectional shape than the wire provided in the proximal end portion of the wire into the reinforcing member insertion hole from one surface side of the reinforced concrete structure .
(3) A step of filling the reinforcing member insertion hole with a filler.
(4) from said other side of the reinforced concrete structures, by inserting the cross-sectional shape is larger tip side fixing member from said wire, the wire tip in the reinforced concrete structure is fixed to section, the shear reinforcement member the existing The process of arranging in the state which secured the covering concrete thickness equivalent to the main reinforcement of the reinforced concrete structure . The step of drilling the reinforcing member insertion hole is a step of drilling a general portion having an inner diameter that is larger than the diameter of the wire and smaller than the width dimension of the proximal-side fixing member and the width dimension of the distal-end fixing member;
Forming a widened portion having an inner diameter larger than a width dimension of the proximal-side fixing member formed at a proximal end portion of the reinforcing member insertion hole;
4. The method according to claim 1, further comprising a step of perforating a widened portion formed at a distal end portion of the reinforcing member insertion hole and having an inner diameter larger than a width dimension of the distal end side fixing member. The shearing force reinforcement method according to any one of the above items. An existing reinforced concrete structure, a shear reinforcement member disposed inside a reinforcement member insertion hole formed so as to penetrate the reinforced concrete structure, and a filler filled in the reinforcement member insertion hole A shear force reinforcement structure,
The shear reinforcing member includes a wire, a proximal fixing member fixed to the proximal end and the distal end of the wire, and a distal fixing member , and both ends of the shear reinforcing member are the existing reinforced concrete structure. It is arranged in a state where the covering concrete thickness equivalent to the main reinforcing bar of the object is secured ,
The reinforcing member insertion hole is formed in a general portion having an inner diameter that is larger than a diameter of the wire and smaller than a width dimension of the proximal fixing member, and a proximal end portion of the reinforcing member insertion hole. A shear force reinforcing structure comprising a widened portion having an inner diameter larger than the width dimension of the fixing member.   6. The shear force reinforcing structure according to claim 5, wherein a widened portion having an inner diameter larger than the general portion of the reinforcing member insertion hole is formed at a distal end portion of the reinforcing member insertion hole. It is a shear reinforcement member that is disposed in a reinforcing member insertion hole formed so as to penetrate an existing reinforced concrete structure, with both ends secured with a covering concrete thickness equivalent to the main reinforcement of the existing reinforced concrete structure. There,
A proximal end fixing member and a distal end having a wire length shorter than the extension of the reinforcing member insertion hole, and a width dimension larger than the diameter of the wire, and fixed to the proximal end portion and the distal end portion of the wire rod, respectively. Side fixing member ,
An air vent hole is formed in the base end side fixing member, and an injection hole is formed in the front end side fixing member, respectively . In the wire, a male screw member is integrally formed at the tip thereof,
The front-end fixing member is a steel plate having a circular or polygonal shape with a thickness dimension of 80% to 120% of the diameter of the wire, and a width dimension of 200% to 300% of the diameter of the wire. The steel plate is formed with a female screw, and is fixed to the tip of the wire by screwing a male screw member of the wire into the female screw. Shear force reinforcement member. The wire is processed with a male screw at its tip,
The front-end fixing member is a steel plate having a circular or polygonal shape with a thickness dimension of 80% to 120% of the diameter of the wire, and a width dimension of 200% to 300% of the diameter of the wire. The female plate is formed with a female screw, and the male screw of the wire rod is screwed into the female screw to be fixed to the tip end portion of the wire rod. Shear force reinforcement member. The wire is composed of screw rebar,
The front-end fixing member is a steel plate having a circular or polygonal shape with a thickness dimension of 80% to 120% of the diameter of the wire, and a width dimension of 200% to 300% of the diameter of the wire. The steel plate is formed with a female screw, and is fixed to the tip of the wire by screwing the wire into the female screw. Element.   The base-side fixing member is a steel plate having a circular or polygonal shape with a thickness dimension of 30% to 120% of the diameter of the wire and a width dimension of 200% to 300% of the diameter of the wire. The shear force reinforcing member according to any one of claims 7 to 10, wherein the shear force reinforcing member is fixed to a base end portion of the wire.

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