Reinforcement structure for existing concrete structures and reinforcement method for existing concrete structures

Abstract

To provide a reinforcing structure for an existing concrete structure capable of suppressing costs for construction and maintenance, and improving the shear strength of the existing concrete structure without damaging the appearance of the existing concrete structure.SOLUTION: Provided is a reinforcing structure 10A of an existing concrete structure 1. A first hole 25 is drilled from a lower surface 2a (first surface) of a beam 2 in a vertical direction (first direction) intersecting an axial direction of the beam 2, and a second hole 35 is drilled from a right side surface 2b (second surface) of the beam 2 in a horizontal direction (second direction) intersecting the axial direction and the vertical direction of the beam 2. A filler F is filled in the first hole 25 and the second hole 35, and a first reinforcing bar 21 and a second reinforcing bar 31 are respectively inserted.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a reinforcement structure and a reinforcement method for an existing concrete structure. [Background technology]

[0002] In existing concrete structures in which the slab and beams are integrated, one type of reinforcement structure that reinforces the shear strength of the beam through post-construction involves wrapping reinforcing members such as fiber ropes and fiber sheets around both sides and the underside of the beam (see, for example, Patent Documents 1 and 2). In such a reinforced structure, part of the shear force generated in the beam is borne by the reinforcing member, thereby improving the shear strength of the beam. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2021-088877 [Patent Document 2] Japanese Patent Application Laid-Open No. 2016-166460 Summary of the Invention [Problem to be solved by the invention]

[0004] In the conventional reinforcement structure described above, both ends of the reinforcement member must be fixed to both sides of the beam using anchor members, which increases the construction cost. Furthermore, in the conventional reinforcement structure described above, the reinforcing members are exposed on three sides of the beam, which significantly mars the appearance of the existing concrete structure and increases the frequency of maintenance of the reinforcing members. The present invention aims to solve the above-mentioned problems, reduce construction and maintenance costs, and provide a reinforcement structure and reinforcement method for existing concrete structures that can improve the shear strength of existing concrete structures without damaging the appearance of the existing concrete structures. [Means for solving the problem]

[0005] In order to solve the above problems, the first invention is a reinforcement structure for an existing concrete structure, The existing concrete structure is a structure in which a slab and a beam provided on the underside of the slab are integrated. The aforementioned beam of Bottom surface From the above beam crosses the axis of Vertical direction A first hole portion is drilled in the beam of side From the above beam axial direction and Vertical direction Intersects with horizontal direction The second hole is drilled One first hole portion and two upper and lower second hole portions are arranged at an interval in the axial direction of the beam. A filler is filled into each of the first hole portions and the second hole portions, and a reinforcing steel bar is inserted into each of the first hole portions and the second hole portions. While the inventors were thoroughly studying reinforcing structures for existing concrete structures, they discovered that, for example, placing reinforcing steel bars in a first direction in an existing concrete structure having beams and columns may cause cracks in the first direction in the existing concrete structure, and that if the cracks in the first direction cause the existing concrete structure to displace significantly in the second direction, there is a risk that the shear strength of the existing concrete structure may decrease. This discovery led to the invention of the present application. In the reinforced structure of the present invention, since the reinforcing steel bars are also arranged in the second direction that intersects the first direction, cracks in the first direction can be suppressed even in existing concrete structures whose width is small compared to their axial length. In this way, by suppressing displacement of the existing concrete structure in the second direction, the shear strength of the existing concrete structure can be improved. In addition, in the reinforced structure of the present invention, since the reinforcing steel bars are embedded in the existing concrete structure, the reinforcing steel bars can be easily fixed to the existing concrete structure, and the reinforcing steel bars can be easily fixed to the existing concrete structure. Therefore, the reinforced structure of the present invention reduces construction and maintenance costs and does not impair the appearance of the existing concrete structure.

[0006] In the reinforcing structure, beamWhen multiple reinforcing bars are provided in the axial direction, it is preferable to improve the shear strength of the entire existing concrete structure by alternating the reinforcing bars inserted into the first hole portion and the reinforcing bars inserted into the second hole portion.

[0007] In the above-mentioned reinforced structure, the end of the reinforcing steel bar is beam It is preferable to place the reinforcement bars in a manner that ensures a thickness of cover concrete equivalent to that of the main reinforcement bars to prevent corrosion of the reinforcement bars. In the reinforcing structure, Underside of beam The diameter of the end portion of the second hole portion is enlarged. Beam side It is preferable to enlarge the diameter of the end portion on the side. In this configuration, the filler filled in the enlarged diameter portion of the hole Existing This can improve the anchorage of the ends of the reinforcing steel bars to the concrete structure.

[0008] In the reinforcing structure, beam of One side and The one side placed on the opposite side of The other side It is preferable to place plate members on the first and second holes, respectively, and join both ends of the reinforcing steel bar inserted into the second hole portion to the plate members. In this configuration, the existing concrete structure is sandwiched between the two plate members from the second direction, thereby suppressing displacement of the existing concrete structure in the second direction, thereby improving the shear strength of the existing concrete structure. Furthermore, in the above-described configuration, the reinforcing steel bars and plate members are not exposed on the first surface of the existing concrete structure, so the appearance of the existing concrete structure is not significantly impaired.

[0009] In order to solve the above problem, a second invention is a method for reinforcing an existing concrete structure, The existing concrete structure is a structure in which a slab and a beam provided on the underside of the slab are integrated. First, the above beam of Bottom surface From the above beam crosses the axis of Vertical direction Towards OneA first hole is drilled. Then, a filler is filled into the first hole, and a first reinforcing steel bar is inserted into the first hole. beam At axially spaced positions of beam of side From the above beam axial direction and Vertical direction Intersects with horizontal direction Towards Two top and bottom A second hole is drilled, and then a filler is filled into the second hole, and a second reinforcing steel bar is inserted into the second hole. In the reinforcement method of the present invention, reinforcing bars are also arranged in a second direction that intersects with the first direction, so cracks occurring in the first direction in the existing concrete structure can be suppressed. In this way, displacement of the existing concrete structure in the second direction is suppressed, thereby improving the shear strength of the existing concrete structure. Furthermore, in the reinforcement method of the present invention, the reinforcing steel bars are embedded in the existing concrete structure, which makes it easy to fix the reinforcing steel bars to the existing concrete structure and prevents the reinforcing steel bars from being exposed to the outside. Therefore, the reinforcement method of the present invention reduces construction and maintenance costs and does not damage the appearance of the existing concrete structure. [Effects of the Invention]

[0010] In the reinforcement structure and reinforcement method for existing concrete structures of the present invention, by arranging reinforcing steel bars in two different directions, it is possible to reduce construction and maintenance costs and improve the shear strength of existing concrete structures without damaging the appearance of the existing concrete structure. [Brief explanation of the drawings]

[0011] [Figure 1] 1 is a side view showing a reinforcement structure according to a first embodiment of the present invention. [Figure 2] 2 is a cross-sectional view of the reinforcement structure according to the first embodiment of the present invention taken along line II-II in FIG. 1. [Figure 3]3 is a cross-sectional view of the reinforcement structure according to the first embodiment of the present invention taken along line III-III in FIG. 1. [Figure 4] FIG. 4 is a cross-sectional view showing a modified example of the reinforcement structure according to the first embodiment of the present invention. [Figure 5] FIG. 4 is a cross-sectional view showing a reinforcement structure according to a second embodiment of the present invention. [Figure 6] 10 is a graph showing the relationship between load and displacement in an existing concrete structure using a reinforcement structure according to a second embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0012] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail with reference to the accompanying drawings. In the description of each embodiment, the same components are denoted by the same reference numerals, and duplicated descriptions will be omitted. [First embodiment] Fig. 1 is a side view showing a reinforcement structure according to a first embodiment of the present invention, and Fig. 2 is a cross-sectional view taken along line II-II of Fig. 1 showing the reinforcement structure according to the first embodiment of the present invention. In the first embodiment, a reinforcement structure 10A and a reinforcement method for post-construction reinforcement of the shear strength of a beam 2 of an existing concrete structure 1 shown in FIG. 1 will be described. The existing concrete structure 1 of the first embodiment is a reinforced concrete structure in which a slab 3 and a beam 2 provided on the underside of the slab 3 are integrated together. As shown in Fig. 2, two main reinforcing bars 2d, 2d extending in the axial direction of the beam 2 (horizontal direction in the first embodiment) are arranged at a distance in the left-right direction at the bottom of the beam 2 (see Fig. 1). The beam 2 of the first embodiment has a rectangular cross section. a and , right side 2 b and , left side 2 c and Three sides of the building are exposed to the outside. The lower surface 2a of the beam 2 is an outer surface having a normal line in the vertical direction perpendicular to the axial direction of the beam 2. The right side surface 2b and the left side surface 2c are outer surfaces having a normal line in the horizontal direction perpendicular to the axial direction of the beam 2.

[0013] 1, the reinforcement structure 10A of the first embodiment includes a plurality of first reinforcing bars 21 and a plurality of second reinforcing bars 31 arranged inside a beam 2. Each of the first reinforcing bars 21 and each of the second reinforcing bars 31 are arranged at intervals in the axial direction of the beam 2. Furthermore, the first reinforcing bars 21 and the second reinforcing bars 31 are arranged alternately at intervals in the axial direction of the beam 2. The first reinforcing steel bar 21 is inserted into a first hole 25 formed in the beam 2 , and the second reinforcing steel bar 31 is inserted into a second hole 35 formed in the beam 2 .

[0014] As shown in FIG. 2, the first hole portion 25 is a hole portion with a circular cross section and a bottom that is drilled upward from the lower surface 2a of the beam 2. 5 is , a vertical direction perpendicular to the axial direction of the beam 2 Towards The first hole 25 is formed in the center of the beam 2 in the left-right direction. The first hole portion 25 has a bottom 28 formed at the end on the slab 3 side, and opens to the underside 2a of the beam 2. The inner diameter of the first hole portion 25 is formed slightly larger than the maximum outer diameter of the first reinforcing steel bar 21 (the outer diameter of the anchoring portion 22 in this embodiment), which will be described later.

[0015] The first holes 25 are filled with a filler F and have first reinforcing steel bars 21 inserted therein. The filler F in the first embodiment is mortar that has hardened in the first holes 25. The first reinforcing steel bar 21 is a linear member with a circular cross section, and has anchoring portions 22, 22 with enlarged diameters formed at both ends. In the first embodiment, the first hole 25 is filled with a filler F, and the first reinforcing steel bar 21 is inserted into the first hole 25 before the filler F hardens. In this way, the first reinforcing steel bar 21 is arranged inside the existing beam 2. The anchoring portion 22 at the upper end of the first reinforcing steel bar 21 is arranged in the bottom portion 28 of the first hole 25. Note that the filler F may be filled into the first hole 25 after the first reinforcing steel bar 21 is inserted into the first hole 25. Anchoring portions 22 at the lower ends of first reinforcing bars 21 are arranged in a state in which a thickness of concrete cover equivalent to that of main reinforcing bars 2d of beam 2 is ensured.

[0016] 1, in the reinforcement structure 10A of the first embodiment, a plurality of first holes 25 are formed at intervals in the axial direction of the beam 2. Furthermore, each of the first holes 25 is filled with a filler F and has a first reinforcing steel bar 21 inserted therein. As a result, inside the beam 2, a plurality of first reinforcing steel bars 21 are arranged at intervals in the axial direction of the beam 2.

[0017] FIG. 3 is a cross-sectional view taken along line III-III in FIG. 1, showing the reinforcement structure according to the first embodiment of the present invention. As shown in FIG. 3, the second hole 35 is a bottomed hole with a circular cross section that is drilled from the right side surface 2b of the beam 2 toward the left. The second hole 35 is oriented in a horizontal direction perpendicular to the axial direction and vertical direction of the beam 2. Towards It's extending. 1, the second hole portion 35 is disposed between the first hole portions 25, 25 adjacent to each other in the axial direction of the beam 2. In the first embodiment, the two second hole portions 35, 35 are disposed at the same position in the axial direction of the beam 2, spaced apart in the vertical direction. 3, the inner diameter of the second hole portion 35 is formed slightly larger than the maximum outer diameter of the second reinforcing steel bar 31 (the outer diameter of the anchoring portion 32 in this embodiment), which will be described later. The inner diameter of the second hole portion 35 opens to the right side surface 2b of the beam 2. A bottom 38 is formed at the end of the left side surface 2c of the second hole 35. The bottom 38 of the second hole 35 is positioned so as to ensure a cover concrete thickness equivalent to that of the main reinforcing bars 2d of the beam 2.

[0018] The second hole 35 is filled with a filler material F, and a second reinforcing steel bar 31 is inserted therein. The second reinforcing steel bar 31 is a steel bar similar to the first reinforcing steel bar 21, and has anchorage portions 32, 32 formed at both ends. The second reinforcing steel bar 31 is also placed inside the existing beam 2 by being inserted into the second hole 35 before the filler material F filled in the second hole 35 hardens. Note that the second hole 35 may be filled with the filler material F after the second reinforcing steel bar 31 is inserted therein. The anchoring portion 32 at the left end of the second reinforcing steel bar 31 is disposed within the bottom portion 38 of the second hole portion 35. The anchoring portions 32, 32 at the left and right ends of the second reinforcing steel bar 31 are disposed in a state in which a cover concrete thickness equivalent to that of the main reinforcing steel bar 2d of the beam 2 is secured.

[0019] 1, in the reinforcement structure 10A of the first embodiment, two upper and lower second hole portions 35, 35 are arranged at an interval in the axial direction of the beam 2. The first hole portions 25 and the second hole portions 35 are arranged alternately in the axial direction of the beam 2. Each second hole portion 35 is filled with a filler F, and a second reinforcing steel bar 31 is inserted therein. As a result, inside the beam 2, the first reinforcing bars 21 and the second reinforcing bars 31 are alternately arranged at intervals in the axial direction of the beam 2. In addition, as shown in FIG. 2, the first reinforcing bars 21 and the second reinforcing bars 31 are perpendicular to each other when viewed from the axial direction of the beam 2.

[0020] Next, a method for reinforcing an existing concrete structure using the reinforcing structure 10A of the first embodiment will be described. First, a hole is drilled upward from the lower surface 2a of the beam 2 shown in Fig. 2 to form a first hole 25 in the beam 2. Next, a filler F is filled into the first hole 25, and a first reinforcing steel bar 21 is inserted into the first hole 25 before the filler F hardens. Then, as shown in Figure 1, multiple first holes 25 are formed sequentially at intervals in the axial direction of the beam 2, and filler material F is filled into each first hole 25, and first reinforcing bars 21 are inserted.

[0021] Next, holes are drilled from the right side surface 2b of the beam 2 toward the left at positions between the first hole portions 25, 25 adjacent to each other in the axial direction of the beam 2 shown in Figure 3 to form two upper and lower second hole portions 35, 35 in the beam 2. Next, the second hole portions 35 are filled with a filler material F, and before the filler material F hardens, a second reinforcing steel bar 31 is inserted into the second hole portions 35. Then, as shown in Figure 1, multiple second holes 35 are formed sequentially at intervals in the axial direction of the beam 2, and filler material F is filled into each second hole 35, and second reinforcing bars 31 are inserted. As a result, a reinforcing structure 10A is formed in which first reinforcing bars 21 arranged in the vertical direction and second reinforcing bars 31 arranged in the horizontal direction are alternately arranged in the axial direction of the beam 2.

[0022] In the reinforcement structure 10A and reinforcement method of the first embodiment described above, as shown in Figure 2, first reinforcing steel bars 21 are arranged in the vertical direction (first direction), and second reinforcing steel bars 31 are also arranged in the horizontal direction (second direction) that intersects the vertical direction. Therefore, the reinforcement structure 10A and the reinforcement method of the first embodiment can suppress vertical cracking even in a beam 2 whose width is small compared to its axial length. In this way, by suppressing horizontal displacement of the beam 2, the shear strength of the existing concrete structure 1 can be improved. Furthermore, in the reinforcement structure 10A and reinforcement method of the first embodiment, as shown in Figure 1, the first reinforcing steel bars 21 and the second reinforcing steel bars 31 are arranged alternately throughout the entire axial direction of the beam 2, thereby improving the shear strength of the entire beam 2.

[0023] In addition, in the reinforcement structure 10A and reinforcement method of the first embodiment, as shown in Figures 2 and 3, the first reinforcing steel bar 21 and the second reinforcing steel bar 31 are embedded in the beam 2, making it easy to fix the first reinforcing steel bar 21 and the second reinforcing steel bar 31 to the beam 2, and the first reinforcing steel bar 21 and the second reinforcing steel bar 31 are not exposed to the outside. Therefore, the reinforcement structure 10A and the reinforcement method of the first embodiment reduce construction and maintenance costs, and do not impair the appearance of the existing concrete structure 1.

[0024] In addition, in the reinforcement structure 10A of the first embodiment, the ends of the first reinforcing steel bars 21 and the ends of the second reinforcing steel bars 31 have a cover concrete thickness equivalent to that of the main reinforcing steel bars 2d of the beam 2, thereby preventing corrosion of the first reinforcing steel bars 21 and the second reinforcing steel bars 31.

[0025] Although the first embodiment of the present invention has been described above, the present invention is not limited to the first embodiment and can be modified as appropriate within the scope of the invention. In the reinforcement structure 10A of the first embodiment, as shown in Figure 2, one first reinforcing steel bar 21 and two upper and lower second reinforcing steel bars 31, 31 are arranged alternately in the axial direction of the beam 2, but the number and arrangement of the first reinforcing steel bar 21 and the second reinforcing steel bars 31 are not limited. For example, the first reinforcing bars 21 and the second reinforcing bars 31 may be arranged alternately one by one. Alternatively, a plurality of first reinforcing bars 21 and a plurality of second reinforcing bars 31 may be arranged alternately. In addition, a group of a plurality of first reinforcing bars 21 arranged continuously in the axial direction of the beam 2 and a group of a plurality of second reinforcing bars 31 arranged continuously in the axial direction of the beam 2 may be arranged alternately. In addition, in the reinforcement structure 10A of the first embodiment, the first reinforcing steel bars 21 arranged in the vertical direction and the second reinforcing steel bars 31 arranged in the horizontal direction are perpendicular to each other, but the angle between the first reinforcing steel bars 21 and the second reinforcing steel bars 31 is not limited. Furthermore, the first reinforcing steel bars 21 and the second reinforcing steel bars 31 may intersect at an angle other than perpendicular.

[0026] In the reinforcing direction of the first embodiment, multiple first reinforcing bars 21 are placed in the beam 2, and then multiple second reinforcing bars 31 are placed in the beam 2, but the order in which the first reinforcing bars 21 and the second reinforcing bars 31 are placed is not limited. For example, after placing a plurality of second reinforcing bars 31 in the beam 2, a plurality of first reinforcing bars 21 may be placed in the beam 2.

[0027] FIG. 4 is a cross-sectional view showing a modified example of the reinforcement structure according to the first embodiment of the present invention. In a modified example of the reinforcing structure 1A shown in FIG. 4 , the anchoring portion 22 at the lower end of the first reinforcing bar 21 is formed in a rectangular plate shape that is larger than the anchoring portion 22 at the upper end, and an expanded diameter portion 27 is formed at the end of the first hole 25 on the lower surface 2a side, and the anchoring portion 22 at the lower end of the first reinforcing bar 21 is disposed within the expanded diameter portion 27. In addition, the anchoring portion 32 at the right end of the second reinforcing bar 31 is formed in a rectangular plate shape that is larger than the anchoring portion 32 at the left end, and an expanded diameter portion 37 is formed at the end of the second hole 35 on the right surface 2b side, and the anchoring portion 32 at the right end of the second reinforcing bar 31 is disposed within the expanded diameter portion 37. This configuration can improve the anchorage of the end of the first reinforcing bar 21 and the end of the second reinforcing bar 31 to the beam 2.

[0028] The reinforcement structure 10A and the reinforcement method of the first embodiment reinforce the beam 2 of the existing concrete structure 1 in which the slab 3 and the beam 2 are integrated. As a reference example, For example, it can be applied to various existing concrete structures such as walls and pillars that extend in one direction.

[0029] [Second embodiment] FIG. 5 is a cross-sectional view showing a reinforcement structure according to a second embodiment of the present invention. As shown in FIG. 5, the reinforcement structure 10B of the second embodiment has substantially the same configuration as the reinforcement structure 10A of the first embodiment (see FIG. 2), but differs in that it is provided with left and right plate members 40, 40. In a reinforcement structure 10B of the second embodiment, plate members 40, 40 are respectively superimposed on the right side surface 2b and the left side surface 2c of a beam 2. The plate member 40 of the second embodiment is a flat steel plate. Both ends of the second reinforcing steel bar 31 are joined to the plate members 40, 40 by joining means such as welding or bolt joints. The plate member 40 may be formed in a strip shape extending in the axial direction of the beam 2, and multiple second reinforcing bars 31 arranged in the axial direction of the beam 2 may be joined to one plate member 40. Alternatively, multiple plate members 40 may be arranged at intervals in the axial direction of the beam 2, and one second reinforcing bar 31 may be joined to one plate member 40. In the reinforcement structure 10B of the second embodiment, the beam 2 is sandwiched from the left and right by the left and right plate members 40, 40. As a result, the horizontal displacement of the beam 2 is suppressed by the both plate members 40, 40 together with the second reinforcing steel bar 31, and therefore the shear strength of the beam 2 can be improved. Furthermore, in the reinforcement structure 10B of the second embodiment, the first reinforcing steel bars 21, the second reinforcing steel bars 31 and the plate members 40 are not exposed on the underside 2a of the beam 2, so the appearance of the existing concrete structure 1 is not significantly impaired.

[0030] FIG. 6 is a graph showing the relationship between load and displacement in an existing concrete structure using a reinforcing structure according to the second embodiment of the present invention. When comparing the shear strength of a beam 2 using the reinforcement structure 10B of the second embodiment with the shear strength of a reinforced concrete beam using a conventional closed-type reinforcement structure, the beam 2 using the reinforcement structure 10B has a reduced decrease in shear strength, as shown in the graph in Figure 6. This shows that the shear strength of the beam 2 using the reinforcement structure and reinforcing method of the present invention is improved compared to the beam using the conventional closed-type reinforcement structure.

[0031] The second embodiment of the present invention has been described above, but the present invention is not limited to the second embodiment, and similar to the first embodiment, it can be modified as appropriate within the scope of the spirit thereof. [Explanation of symbols]

[0032] 1 Existing concrete structures 2 beams 2a Bottom side 2b Right side 2c Left side 2d Main Reinforcement 3. Slab 10A Reinforcement structure (first embodiment) 10B Reinforcement structure (second embodiment) 21 First reinforcing bar 22 Fixing section 25 First hole 27 Expanded diameter part 28 Bottom 31 Secondary reinforcing steel bar 32 Fixing section 35 Second hole 36 General section 37 Expanded diameter part 38 Bottom 40 Plate members F Filling material

Claims

1. A reinforcement structure for an existing concrete structure, The existing concrete structure is a structure in which a slab and a beam provided on the underside of the slab are integrated, A first hole portion is drilled from the lower surface of the beam in a vertical direction intersecting the axial direction of the beam, and A second hole portion is drilled from the side surface of the beam in a horizontal direction intersecting the axial direction and vertical direction of the beam, One of the first holes and two of the second holes, one above the other, are arranged at an interval in the axial direction of the beam, A reinforcement structure for an existing concrete structure, characterized in that a filler is filled into the first hole portion and the second hole portion, and a reinforcing steel bar is inserted into each of the first hole portion and the second hole portion.

2. A plurality of the reinforcing steel bars are provided in the axial direction of the beam, A reinforcement structure for an existing concrete structure as described in claim 1, characterized in that the reinforcing steel bars inserted into the first hole portion and the reinforcing steel bars inserted into the second hole portion are arranged alternately.

3. The reinforcement structure for an existing concrete structure as described in claim 1, characterized in that the ends of the reinforcing steel bars are arranged in a state ensuring a cover concrete thickness equivalent to that of the main reinforcing bars of the beam.

4. The first hole portion has an expanded diameter at an end portion on the lower surface side of the beam, 2. The reinforcement structure for an existing concrete structure according to claim 1, wherein the second hole portion has an enlarged diameter at an end portion on the side surface of the beam.

5. a plate member is superimposed on one side surface of the beam and on the other side surface disposed opposite to the one side surface; A reinforcing structure for an existing concrete structure as described in claim 1, characterized in that both ends of the reinforcing steel bar inserted into the second hole portion are respectively joined to both of the plate members.

6. A method for reinforcing an existing concrete structure, comprising: The existing concrete structure is a structure in which a slab and a beam provided on the underside of the slab are integrated, A step of drilling one first hole portion from the lower surface of the beam in a vertical direction intersecting the axial direction of the beam; Filling the first hole with a filler and inserting a first reinforcing steel bar into the first hole; A step of drilling two upper and lower second hole portions from a side surface of the beam in a horizontal direction intersecting the axial direction and vertical direction of the beam at a position spaced apart from the first hole portion in the axial direction of the beam; Filling the second hole with a filler and inserting a second reinforcing steel bar into the second hole; A method for reinforcing an existing concrete structure, comprising:

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