Reinforcement method, installation member, and reinforcing member

Abstract

A reinforcement method, structure, installation member, and reinforcement member are provided that can easily reinforce a member that has an axial length and is subjected to at least one of an axial load and a bending load. [Solution] The reinforcement method is a method for reinforcing a member that has an axial length and is subjected to at least one of an axial load and a bending load, in which an FRP restraining tube is attached so as to cover part or all of the outer periphery of the member in the axial direction, and a filler material is filled inside the restraining tube.

Description

[Technical Field]

[0001] The present invention relates to a reinforcement method, a structure, an installation member, and a reinforcement member. [Background technology]

[0002] Patent Document 1 discloses a buckling-restrained brace consisting of a brace core, a buckling restraint material for the core, and an outer cylinder that holds the buckling restraint material. In the buckling-restrained brace of Patent Document 1, polyurethane foam as the buckling restraint material is injected into the outer cylinder. The outer cylinder has a tubular structure made of steel. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2005-220637 Summary of the Invention [Problem to be solved by the invention]

[0004] In the buckling-restrained brace of Patent Document 1, the outer cylinder is made of steel, which makes the outer cylinder heavy and large in size. For this reason, it is difficult to reinforce an existing brace by installing an outer cylinder and buckling restraint material. Therefore, in the past, prefabricated braces reinforced in advance with an outer cylinder and buckling restraint material in a factory or the like were transported to the construction site and installed on the structure.

[0005] The brace is an example of a member that has a length in the axial direction and receives at least one of an axial load and a bending load.

[0006] An object of the present invention is to provide a reinforcement method, structure, installation member, and reinforcement member that can easily reinforce a member that has an axial length and is subjected to at least one of an axial load and a bending load. [Means for solving the problem]

[0007] The first embodiment of the reinforcement method is a method for reinforcing a member that has an axial length and is subjected to at least one of an axial load and a bending load, in which an FRP restraining tube is attached so as to cover part or all of the outer periphery of the member in the axial direction, and a filler material is filled inside the restraining tube.

[0008] In the reinforcing method of the first aspect, the restraining pipe attached to the outer periphery of the component is made of FRP, which makes it lighter in weight and easier to handle than a steel restraining pipe, allowing the component to be reinforced easily.

[0009] In the reinforcing method of the second aspect, in the first aspect, the restraining pipe is attached to the member in a state where both axial end portions of the member are attached to a structure.

[0010] In the reinforcing method of the second aspect, there is no need to remove the member from the structure, so the member can be reinforced easily.

[0011] In the reinforcing method of the third aspect, in the first or second aspect, the restraint pipe is made up of a plurality of separated portions that form part of the circumferential direction of the restraint pipe.

[0012] Therefore, the restraint pipe can be attached to the member with both axial ends of the member attached to the structure, and the member can be reinforced easily.

[0013] In the reinforcement method of the fourth aspect, in any one of the first to third aspects, the restraint pipe is made of FRP having reinforcing fibers made of at least one of carbon fibers, glass fibers, and aramid fibers, and resin.

[0014] In this way, the restraining pipe may be made of FRP containing reinforcing fibers made of at least one of carbon fibers, glass fibers, and aramid fibers, and resin.

[0015] In a fifth aspect of the reinforcing method, in any one of the first to fourth aspects, the filler is a foam material.

[0016] In this way, a foam material can be used as the filler.

[0017] A sixth aspect of the reinforcing method is any one of the first to fifth aspects, wherein the restraint pipe is formed in a cylindrical shape.

[0018] In this way, a cylindrically shaped restraint tube can be used.

[0019] A seventh aspect of the reinforcing method is the method of any one of the first to sixth aspects, in which a fiber sheet is wrapped around an outer periphery of the restraining pipe at least in the circumferential direction.

[0020] Therefore, the reinforcing effect of reinforcing the member can be improved.

[0021] An eighth aspect of the reinforcing method is the seventh aspect, wherein the restraint pipe has its fibers oriented in its axial direction, and the fiber sheet has its fibers oriented in the circumferential direction of the restraint pipe.

[0022] Therefore, the fiber direction of the restraint pipe and the fiber direction of the fiber sheet intersect, further enhancing the reinforcing effect.

[0023] In the structure of the ninth aspect, the member is reinforced by the reinforcing method of any one of the first to eighth aspects.

[0024] In the structure of the ninth aspect, the restraining pipes attached to the outer periphery of the member are made of FRP, and therefore are lighter in weight and easier to handle than if the restraining pipes were made of steel. This makes it possible to reinforce the member simply and easily.

[0025] The installation member of the tenth aspect comprises a member having an axial length and adapted to receive at least one of an axial load and a bending load in a structure, an FRP restraining tube attached so as to cover part or all of the outer periphery of the member in the axial direction, and a filler material filled inside the restraining tube.

[0026] In the installation member of the tenth aspect, the restraining pipe attached to the outer periphery of the member is made of FRP, and therefore is lighter in weight and easier to handle than when the restraining pipe is made of steel. This makes it possible to reinforce the member easily.

[0027] The reinforcing member of the eleventh aspect is a reinforcing member that is provided to a structure, has an axial length, and reinforces a member that receives at least one of an axial load and a bending load, and includes an FRP restraining tube that is attached so as to cover part or all of the outer periphery of the member in the axial direction, and a filler that is filled inside the restraining tube.

[0028] In the reinforcing member of the eleventh aspect, the restraining pipe attached to the outer periphery of the member is made of FRP, and therefore is lighter in weight and easier to handle than when the restraining pipe is made of steel. This makes it possible to reinforce the member simply and easily. [Effects of the Invention]

[0029] According to the present invention, a member that has a length in the axial direction and that is subjected to at least one of an axial load and a bending load can be easily reinforced. [Brief explanation of the drawings]

[0030] [Figure 1] 1 is a schematic diagram showing an example of a member to be reinforced by a reinforcing method according to an embodiment of the present invention. FIG. [Figure 2] 1 is a cross-sectional view showing an example of a member reinforced by the reinforcing method according to the present embodiment. [Figure 3] FIG. 10 is a perspective view showing a state in which a member is covered with a restraint tube in the reinforcing method according to the present embodiment. [Figure 4] FIG. 2 is a cross-sectional view showing an example of a restraint pipe according to the present embodiment. [Figure 5] FIG. 10 is a cross-sectional view showing an example of a restraint pipe according to a modified example. [Figure 6] 1 is a perspective view illustrating an example of a fiber sheet according to an embodiment of the present invention. [Figure 7] 10A and 10B are diagrams illustrating an example of a cap according to the present embodiment. [Figure 8] 5 is a schematic diagram showing an example of a placement step of placing an interposition member on a member in the reinforcing method according to the embodiment. FIG. [Figure 9] 5 is a schematic diagram showing an example of an attachment step of attaching a restraint pipe to a member in the reinforcing method according to the present embodiment. FIG. [Figure 10] 5A to 5C are schematic views showing an example of a mounting step of mounting a cap on a member in the reinforcing method according to the embodiment. [Figure 11] 5 is a schematic diagram showing an example of a winding step of winding a fiber sheet around the outer periphery of a restraining pipe in the reinforcing method according to the present embodiment. FIG. [Figure 12] 10 is a schematic view showing an example of a circumferential winding step for removing a cap from a member in the reinforcing method according to the embodiment. FIG. [Figure 13] 1 is a photograph showing specimens of a comparative example (unreinforced) and an example (reinforced) after a static compression test. [Figure 14] 1 is a table (Table 1) showing test results of a static compression test of a comparative example (unreinforced) and an example (reinforced). [Figure 15] 1 shows load-displacement curves in an alternating positive and negative load test for a comparative example (unreinforced) and an example (reinforced). [Figure 16] 1 is a table (Table 2) showing the calculation results of cumulative absorbed energy calculated from the results of alternating positive and negative load tests of a comparative example (unreinforced) and an example (reinforced body). DETAILED DESCRIPTION OF THE INVENTION

[0031] An example of an embodiment of the present invention will be described below with reference to the drawings.

[0032] <Reinforcement method> 2, the reinforcing method according to this embodiment is a method for reinforcing a member 12 (see FIG. 1) that is the target of reinforcement, using a restraining tube 20, a fiber sheet 40, a filler 30, an interposing member 60, and a cap 50 (see FIG. 7). The restraining tube 20, the fiber sheet 40, the filler 30, the interposing member 60, and the cap 50 are examples of reinforcing members for reinforcing the member 12.

[0033] Below, we will explain the components 12, the restraining pipe 20, the fiber sheet 40, the filler 30, the interposed member 60, and the cap 50 that are to be reinforced. After that, we will explain the procedure of the reinforcement method, the effects of this embodiment, evaluation tests, and modified examples.

[0034] <Component 12> 1, the member 12 to be reinforced has a length in the axial direction (the direction of the arrow X) and is subjected to at least one of an axial load and a bending load. For example, one end and the other end of the member 12 in the axial direction are attached to the structure 11.

[0035] In this embodiment, for example, a brace provided in a building as the structure 11 is used as the member 12. The brace member 12 is made of, for example, steel. As shown in FIG. 1 , the member 12 has a main body 14 and a pair of connecting portions 16.

[0036] The main body 14 has a length in the axial direction (the direction of the arrow X). Specifically, as shown in Fig. 2, the main body 14 is configured by a pair of angle members 14A having an L-shaped cross section. The main body 14 is formed by the pair of angle members 14A into a substantially T-shaped cross section.

[0037] The pair of connecting portions 16 are components that connect the main body 14 and the structure 11. The connecting portions 16 are made of gusset plates. Each of the pair of connecting portions 16 is fastened to one end and the other end of the main body 14 in the axial direction (longitudinal direction, arrow X direction) by fastening members 18 such as bolts.

[0038] Furthermore, each of the pair of connecting portions 16 is joined to a structure 11 (building) having, for example, a beam 11A and a column 11B. Specifically, each of the pair of connecting portions 16 is joined to the beam 11A and the column 11B at each side 16Y of the corner 16X, for example, at a joint 11C between the beam 11A and the column 11B. In this manner, both ends of the member 12 in the axial direction are attached to the structure 11. One method for joining the connecting portions 16 to the structure 11 is welding. The member 12, which is a brace, is a member that receives both an axial load and a bending load.

[0039] In this embodiment, the member 12 has a substantially T-shaped cross section, but is not limited to this. The shape of the member of the present disclosure may be H-shaped, groove-shaped, circular, rectangular, flat, etc. Furthermore, various shapes, such as those tapered in the longitudinal direction, can be reinforced.

[0040] In this embodiment, a brace is used as an example of the member 12, but the members of the present disclosure are not limited to braces. The members of the present disclosure may be, for example, columns, beams, truss diagonal members, etc. Any member that has a length in the axial direction and receives at least one of an axial load and a bending load can be a target for reinforcement.

[0041] The material of the members of the present disclosure is not limited to steel, but may be concrete, wood, fiber-reinforced plastic, etc., and the material of the members of the present disclosure is not limited to a specific one.

[0042] The structure of the present disclosure is not limited to a building, but may be any structure that includes the components of the present disclosure. The structure of the present disclosure may be constructed solely from the components of the present disclosure.

[0043] <Restricted tube 20> Restraint pipe 20 is made of an FRP pipe made of reinforcing fiber and resin. As shown in Figures 2 and 3, restraint pipe 20 is formed in a cylindrical shape with an inner diameter that can accommodate member 12 therein with a gap between it and member 12 (a non-contact state).

[0044] 2 and 3, the main body portion 14 and the restraint pipe 20 are shown in a simplified manner, and portions of the member 12 other than the main body portion 14 are not shown.

[0045] Examples of reinforcing fibers that can be used include organic fibers such as aramid, PBO (polyparaphenylene benzbisoxazole), polyamide, polyarylate, and polyester, and metal fibers such as basalt fiber, fly ash fiber, carbon fiber, glass fiber, and steel fiber, either singly or in combination. However, examples of reinforcing fibers are not limited to these.

[0046] As the resin, thermosetting resins such as room temperature curing or thermosetting epoxy resin, vinyl ester resin, acrylic resin, unsaturated polyester resin, and phenol resin, and thermoplastic resins such as in situ polymerization type phenoxy resin, nylon, and vinylon can be used, and preferably, for example, epoxy resin, which is a thermosetting resin, is used.

[0047] In the restraint pipe 20, the fiber directions of the reinforcing fibers are oriented in the axial direction (arrow X direction, 0°) and circumferential direction (arrow Y direction, 90°) of the member 12. In this embodiment, for example, the amount of fibers oriented in the axial direction of the member 12 is greater than the amount of fibers oriented in the circumferential direction (arrow Y direction). However, the fiber direction of the reinforcing fibers is not particularly limited, and any fiber direction can be used. Specifically, if the fiber direction is one-way, it can be only the axial direction of the member 12, if the fiber direction is two-way, it can be two directions at angles within ±45° from the axial direction, or if the fiber direction is three-way, it can be a combination of fiber directions such as an angle within ±45° from the axial direction and the circumferential direction, but it is preferable that the fiber direction be two or more directions.

[0048] Restraint pipe 20 is manufactured using a pultrusion method, a sheet winding method, or a filament winding method, and is divided into two in the axial direction using a tip saw or the like, so that, as shown in FIG. 4 , it is configured with a plurality of separated constituent parts 22 (an example of a part) that form part of the circumferential direction of restraint pipe 20. In this embodiment, constituent parts 22 are formed in a semicircular shape. That is, in this embodiment, restraint pipe 20 is configured with a pair of constituent parts 22 that are formed by splitting a cylinder in half. Constituent parts 22 are joined in a direction perpendicular to the axial direction of member 12 (direction of arrow Z), thereby configuring a pipe that covers the outer periphery of member 12.

[0049] In the present embodiment, restraint pipe 20 is configured with a pair of semicircular constituent portions 22, but is not limited to this. The restraint pipe of the present disclosure may be formed in a cylindrical shape having a slit 25 along the axial direction, for example, as shown in Fig. 5. In the example shown in Fig. 5, a portion of the circumferential direction of restraint pipe 20 serves as hinge portion 23, and slit 25 is formed at a position opposing hinge portion 23.

[0050] Furthermore, in this embodiment, the restraint pipe 20 is formed in a cylindrical shape (i.e., a circular cross section), but the restraint pipe of the present disclosure is not limited to this. While a cylindrical shape is most preferable for the restraint pipe of the present disclosure, it may be, for example, a rectangular cylindrical shape (i.e., a square cross section) or a polygonal cylindrical shape (i.e., a polygonal cross section), as long as it is cylindrical. Note that when the restraint pipe 20 is a rectangular cylindrical or polygonal cylindrical shape, it is desirable that the corners are rounded to make it easier to attach the fiber sheet 40.

[0051] Furthermore, the restraint tube of the present disclosure only needs to have a cylindrical (tubular) final shape after covering the member, and may have, for example, a strip or sheet shape before covering the member.

[0052] <Fiber sheet 40> The fiber sheet 40 is a sheet material that includes reinforcing fibers and reinforces the member 12. The fiber sheet 40 is wrapped around the outer periphery of the restraint pipe 20 in at least the circumferential direction of the restraint pipe 20. In this embodiment, the fiber sheet 40 is adhered to the outer periphery of the restraint pipe 20 with an adhesive.

[0053] For example, a room temperature curing epoxy resin is used as the adhesive used to bond the fiber sheet 40. However, the adhesive is not limited to a room temperature curing epoxy resin, and various resins can be used, such as an epoxy acrylate resin, an acrylic resin, an MMA resin, a vinyl ester resin, an unsaturated polyester resin, or a photocurable resin.

[0054] The reinforcing fibers used in the fiber sheet 40 are, for example, carbon fibers. That is, in this embodiment, a carbon fiber sheet is used as the fiber sheet 40. The reinforcing fibers are not limited to carbon fibers, and various fibers can be used, such as organic fibers such as aramid, PBO (polyparaphenylene benzbisoxazole), polyamide, polyarylate, and polyester, and metal fibers such as basalt fiber, glass fiber, and steel fiber. Furthermore, the reinforcing fibers are not limited to one type, and multiple types can be selected and used.

[0055] Specifically, as shown in FIG. 6, the fiber sheet 40 includes a fiber layer 44 in which reinforcing fibers 42 (continuous fibers) are arranged in one direction (the direction of arrow A in FIG. 6), and a support layer 46 that supports the fiber layer 44. The support layer 46 is disposed on one side of the fiber layer 44 and is configured as a mesh-like support sheet that supports the fiber layer 44. This support layer 46 prevents the reinforcing fibers 42 of the fiber layer 44 from becoming loose. Thus, in the fiber sheet 40, the direction of arrow A is the fiber direction. Note that the support layer 46 may be disposed on both sides of the fiber layer 44, and a configuration without the support layer 46 is also possible as long as the loosening of the reinforcing fibers 42 is prevented in some way.

[0056] In this embodiment, the fiber sheet 40 is wound around and adhered to the outer periphery of the restraint pipe 20 in the circumferential direction so that the fiber direction of the fiber sheet 40 is aligned with the circumferential direction of the restraint pipe 20 .

[0057] Note that an example of the fiber sheet is not limited to fiber sheet 40 shown in Fig. 6, and may be any fiber sheet containing fiber. Examples of the fiber sheet include, for example, a woven fabric in which reinforced fibers are plain woven or satin woven, a prepreg sheet in which a unidirectional reinforced fiber substrate is pre-impregnated with an adhesive used to bond fiber sheet 40, and a sheet made of flexible fiber-reinforced thermoplastic plastic; the former is wrapped around restraint pipe 40 as is and bonded and cured, and the latter is softened by applying heat and then wrapped and bonded, or wrapped and bonded using a separate adhesive.

[0058] Furthermore, a plurality of fiber sheets according to the present disclosure may be stacked and wound around the outer periphery of the restraint tube according to the present disclosure. In this case, the fiber sheets can be wound so that the fiber directions of the fiber sheets intersect with each other.

[0059] <Filling material 30> Filler 30 is a filler material that is filled inside restraint pipe 20. A foam material is used as filler 30. Specifically, a foam-in-place material such as polyurethane foam is used as the foam material. Polyurethane foam is obtained, for example, by mixing polyisocyanate, polyol, and additives (catalyst, blowing agent, foam stabilizer, etc.) at the construction site and causing a foaming reaction and a resinification reaction.

[0060] Filler 30 is filled into restraint tube 20 from, for example, one axial end of restraint tube 20 attached to member 12. In this embodiment, polyurethane foam is used as filler 30, but this is not limited to this. Filler materials of the present disclosure may be, for example, resin-based foams such as resol-type phenolic, melamine-based, epoxy-based, and silicone-based, as well as inorganic foams such as lightweight foamed mortar.

[0061] <Cap 50> The cap 50 is a member used in the process of carrying out the reinforcement method. The cap 50 has a positioning function for positioning the restraint tube 20 relative to the member 12, and an outflow restriction function for restricting the outflow of the filler material 30 when the filler material 30 is being filled.

[0062] In this embodiment, as shown in FIG. 9, the caps 50 are configured as a pair, each attached to one end and the other end of the member 12 in the axial direction.

[0063] Each of the pair of caps 50 is formed into a disk shape using a 3D printer or injection molding method using a resin material such as nylon, polyolefin, or polyester, and has a hole 53 formed therein for passing the member 12 therethrough, as shown in Fig. 7. Furthermore, the cap 50 is formed from a pair of components 52 formed by splitting the disk in half. The components 52 are attached to the member 12 by being joined in a direction perpendicular to the axial direction of the member 12 (the direction of the arrow Z).

[0064] Furthermore, of the pair of caps 50 , the cap 50 attached to the side where the filler 30 is filled has an opening 54 formed therein that allows the filler 30 to flow into the inside of the restraint pipe 20 .

[0065] By temporarily fixing the restraint pipe 20 to the member 12 via the cap 50, the restraint pipe 20 is positioned relative to the member 12. The cap 50 is eventually removed from the member 12.

[0066] <Interposition member 60> The interposing member 60 (see FIGS. 2 and 8) is a member that is disposed between the member 12 and the filler 30. The interposing member 60 is formed, for example, from a cushion tape. In this embodiment, instead of providing a gap between the member 12 and the filler 30, the interposing member 60, which has low rigidity, is disposed between the member 12 and the filler 30. This prevents the member 12 and the filler 30 from contacting each other, making it difficult for a load to be transmitted directly from the member 12 to the filler 30. Furthermore, it becomes possible to provide a deformation allowance for the member 12.

[0067] <Reinforcement method procedure> The steps of the method for reinforcing the component 12 according to this embodiment are shown below, but various modifications, changes, and additional steps are possible. As an example, the reinforcing method includes a preparation step, an arrangement step, an attachment step, a mounting step, a winding step, a filling step, and a circumferential winding step.

[0068] <Preparation process> In the preparation step, reinforcing members such as the restraint tube 20, the fiber sheet 40, the filler 30, the interposing member 60, and the cap 50 are prepared. The reinforcing members include reinforcing materials and reinforcing tools used to reinforce the member 12.

[0069] The restraining tube 20, the fiber sheet 40, the filler 30, and the interposed member 60 are reinforcing materials. These members exert a reinforcing effect when attached to the member 12.

[0070] The cap 50 is a reinforcing tool, and as described above, will eventually be removed from the member 12. Therefore, the structure 11 after being reinforced by the reinforcing method will not have the cap 50.

[0071] <Placement process> The arranging step is a step of arranging the intervening member 60 on the member 12. In this embodiment, as shown in Fig. 8 and Fig. 2, cushion tapes serving as the intervening members 60 are attached to each surface of the main body 14 of the member 12. Note that the arranging step only needs to be performed at least before the filling step.

[0072] <Installation process> The attachment process is a process of attaching restraint pipe 20 to member 12. In the attachment process, as shown in Figures 9, 5, and 2, component 22 is joined in the orthogonal direction (arrow Z direction) to member 12, thereby attaching restraint pipe 20 to member 12 so as to cover the outer periphery of member 12.

[0073] <Installation process> The mounting step is a step of mounting the caps 50 to the member 12. In the mounting step, as shown in Fig. 10 , after the restraint tube 20 is placed over the member 12, each of the pair of caps 50 is mounted to one end and the other end of the member 12 in the axial direction and temporarily fixed. In this embodiment, each of the pair of caps 50 is mounted to the member 12 by joining the constituent parts 52 of the caps 50 in the orthogonal direction (the direction of the arrow Z) (see Fig. 7 ).

[0074] At this time, the pair of caps 50 are attached so as to cover the outer periphery of each of one end and the other end in the axial direction of the restraint pipe 20. Then, each of the pair of caps 50 is attached to each of the one end and the other end in the axial direction of the restraint pipe 20 by adhesive, mounting tape, or the like.

[0075] By temporarily fixing restraint pipe 20 to member 12 via cap 50, restraint pipe 20 is positioned relative to member 12 with a gap (non-contact state) between the inner circumferential surface of restraint pipe 20 and main body portion 14. Furthermore, restraint pipe 20 is positioned relative to member 12 with a gap (non-contact state) between the axial end of restraint pipe 20 and connection portion 16.

[0076] <Wrapping process> The winding process is a process of winding the fiber sheet 40 around the outer periphery of the restraint tube 20. In the winding process, as shown in Fig. 11 and Fig. 2, the fiber sheet 40 is adhered to the outer periphery of the restraint tube 20 with an adhesive while being wound around the outer periphery of the restraint tube 20 in the circumferential direction of the restraint tube 20.

[0077] <Filling process> The filling step is a step of filling the inside of the restraint pipe 20 with the filler 30. In the filling step, the filler 30 is filled into the inside of the restraint pipe 20 from one axial end of the restraint pipe 20 through the opening 54 of the cap 50 (see FIG. 2). The filling of the filler 30 can be carried out using, for example, a filling machine that uses a compressor.

[0078] <Circumference winding process> The winding step is a step of removing the caps 50 from the restraining tube 20 and the member 12. In the winding step, after the filler 30 has hardened, each of the pair of caps 50 is removed from one end and the other end of the member 12 in the axial direction, as shown in Figures 11 and 12. It is desirable to wind the fiber sheet 40 around the end of the restraining tube 20 that was not wrapped with the cap 50 after removing the cap 50.

[0079] The above-described reinforcement method results in a structure 11 with reinforced member 12. This reinforcement method uses reinforcing members such as FRP restraint pipe 20, fiber sheet 40, and filler material 30, and makes it possible to reinforce member 12 without using heavy machinery or fire.

[0080] In the above-described reinforcement method, the cap 50 is attached to the member 12 after the restraint pipe 20 is attached to the member 12, but this is not limited to this. The cap 50 may be attached to the member 12, and then the restraint pipe 20 may be attached to the member 12. In this case, the restraint pipe 20 may be attached so as to cover the outer periphery of the cap 50.

[0081] Furthermore, the end of the restraining pipe 20 from which the cap 50 has been removed may be separately sealed with a resin material to prevent the intrusion of rainwater or moisture, or the cap 50 may be left in place with only the injection port sealed.

[0082] <Effects of this embodiment> The effects of this embodiment will be described.

[0083] In the reinforcing method according to this embodiment, the restraining pipe 20 attached to the outer periphery of the member 12 is made of FRP, and therefore is lighter in weight and easier to handle than when the restraining pipe 20 is made of steel.

[0084] Therefore, with both axial ends of the existing component 12 attached to the restraint pipes 20, the restraint pipes 20 can be attached to the component at the installation site of the component 12. This makes it possible to reinforce the component 12 without replacing the existing component 12 and without requiring heavy machinery. Therefore, according to the reinforcement method according to this embodiment, the component 12 can be reinforced easily.

[0085] In addition, by using carbon fiber, which is lighter and stronger than steel, it is possible to reduce the size of the restraint pipe 20 while maintaining earthquake resistance, and reinforcement can be easily carried out even in narrow construction locations.

[0086] Furthermore, in this embodiment, the fiber sheet 40 is wrapped around the outer periphery of the restraint pipe 20 at least in the circumferential direction. This provides a high reinforcing effect for reinforcing the member 12. Furthermore, wrapping the fiber sheet 40 around the outer periphery of the restraint pipe 20 also has the effect of integrating the constituent parts 22.

[0087] Furthermore, in this embodiment, the fiber direction of the restraint pipe 20 is oriented in the axial direction, and the fiber direction of the fiber sheet 40 is oriented in the circumferential direction of the restraint pipe 20. Therefore, the fiber direction of the restraint pipe 20 and the fiber direction of the fiber sheet 40 intersect, further enhancing the reinforcing effect.

[0088] <Evaluation test> In this test, the reinforcing effect of the reinforcing method according to the present embodiment was evaluated. Specifically, in this test, the examples and comparative examples were evaluated as follows.

[0089] <Materials used> Braces Two steel angle members (2L-90mm x 90mm x 6mm, made of SS400) were joined with bolts to form an approximately T-shaped cross section. ·CFRP pipe PAN-based carbon fiber (TR50-12L manufactured by Mitsubishi Chemical Corporation) and pitch-based carbon fiber (XN80-A2S manufactured by Nippon Graphite Fiber Co., Ltd.) were used as reinforcing fibers, and epoxy resin was used as the matrix resin to create a CFRP pipe (length: 3400 mm, inner diameter: 200 mm, wall thickness: 6.2 mm) using the filament winding method. Circumferential sheet: Tow sheet (Nippon Steel Chemical & Material Co., Ltd., product number: FTS-C1-30) Foaming agent: 6x foamed urethane (Asahi Organic Materials urethane-based cavity filler ASGR-FIA6 / AGSR-FIB)

[0090] <Specimen> Two semicircular members, made by dividing a CFRP pipe axially with a chip saw into equal pieces, were placed on the brace, which was fitted with a resin end cap, so that the joint between the gusset and the steel angle member of the brace was perpendicular to the joint of the semicircular members. In addition, cushion tape was attached to the part where the end caps were attached to fill the gap with the caps. Next, the brace was oriented so that its cross section formed a T shape, and the brace with the attached CFRP tube was then fixed at a 45° angle. Foam material was then filled in through the opening at the top using a compressor, up to the top edge. Thereafter, the foam material was cured until it hardened, and then the end caps were removed and a circumferential sheet was wound around the material to reinforce the periphery, thereby forming a reinforced body.

[0091] <Compression test> Gussets that had been treated for rusting were attached to both ends of the specimen using high-strength bolts, and a compression test was then carried out using a uniaxial compression test with both ends fixed. A similar test was also carried out on an unreinforced brace, and a photograph of the specimen after the test is shown in Figure 13, and the test results are shown in Table 1 in Figure 14.

[0092] <Alternating positive and negative load test> After joining the gusset to the specimen in the same manner as in the compression test, alternating positive and negative loading was carried out using a uniaxial compression test with both ends fixed. Based on the results of the compression test on the unreinforced specimen, the yield displacement was set to 1δy, with steps of 0.25δy, 0.5δy, δy, 2δy, 3δy, 4δy, 5δy, and 6δy. Tests were conducted on both the reinforced and unreinforced braces, and the energy absorption rate was determined by calculating the area of ​​the envelope from the load-displacement curve at each cycle. Figure 15 shows the load-displacement curve, and Table 2 in Figure 16 shows the calculated cumulative absorbed energy.

[0093] As shown in Table 1 in Figure 15, the maximum load in the static compression test was 1.5 times higher for the reinforced member than for the unreinforced member, and although fracture was observed in the gusset connections of the reinforced member after evaluation, no brace buckling was observed, as was the case with the unreinforced member.In addition, the cumulative absorbed energy of the unreinforced and reinforced members calculated from the results of the alternating positive and negative load tests shown in Table 2 in Figure 16 was similar up to 2δy, regardless of whether or not they were reinforced, but it was confirmed that the cumulative absorbed energy of the reinforced member became greater from 3δy onwards. Furthermore, the ratio (Et' / Ea) of the cumulative absorbed energy Et' at the maximum displacement (6δy) to the cumulative absorbed energy Ea up to the damage limit (δy) was also found to be approximately 1.6 times larger for the reinforced specimen (38.22) than for the unreinforced specimen (23.95).

[0094] The above results confirm that the brace reinforced using the method of the present invention has improved compressive strength and energy absorption capabilities due to the reinforcement, and therefore has sufficient performance as an earthquake-resistant reinforcement member.

[0095] <Modification> In this embodiment, reinforcement is performed on the existing member 12, but this is not limited to this. A configuration in which reinforcement is performed on the member 12 in a state in which it is not attached to the structure 11 is also possible. In this case, by reinforcing the member 12, an installation member including the restraint pipe 20, the fiber sheet 40, the filler 30, and the interposed member 60 is configured.

[0096] Then, this installation member is installed on the structure 11 in place of the member 12 that has not yet been reinforced, thereby reinforcing the structure 11.

[0097] The present invention is not limited to the above-described embodiment, and various modifications, changes, and improvements are possible without departing from the spirit and scope of the present invention. [Explanation of symbols]

[0098] 11 Structures 12 Components 20 Restraint tube 30 Filling material 40 Fiber Sheet 50 caps 60 Intervening member

Claims

1. A member that has an axial length and is subjected to at least one of an axial load and a bending load. A reinforcing method for reinforcing a A restraining pipe made of FRP is attached so as to cover a part or the whole of the outer periphery of the member in the axial direction, and a filler is filled inside the restraining pipe. Reinforcement method.

2. The restraint pipe is attached to the member with both axial ends of the member attached to a structure. The reinforcing method according to claim 1.

3. The restraint pipe is It is composed of a plurality of separated sections that form part of the circumferential direction of the restraint pipe. The reinforcing method according to claim 1.

4. The restraint pipe is It is made of FRP containing reinforcing fibers made of at least one of carbon fiber, glass fiber, and aramid fiber, and resin. The reinforcing method according to claim 1.

5. The filler is a foam material. The reinforcing method according to claim 1.

6. The restraint pipe is formed in a cylindrical shape having a circular cross section, a square cross section, or a polygonal cross section. The reinforcing method according to claim 1.

7. A fiber sheet is wound around the outer periphery of the restraint pipe at least in the circumferential direction. The reinforcing method according to claim 1.

8. The restraint tube has a fiber direction oriented in its axial direction, The fiber direction of the fiber sheet is oriented in the circumferential direction of the restraint pipe. The reinforcing method according to claim 7.

9. A structure in which the member is reinforced by the reinforcing method according to any one of claims 1 to 8.

10. a member having an axial length and adapted to bear at least one of an axial load and a bending load in a structure; a restraint pipe made of FRP attached so as to cover a part or the whole of the outer periphery of the member in the axial direction; a filler filled inside the restraint tube; An installation member comprising:

11. A member that has an axial length and is subjected to at least one of an axial load and a bending load. A reinforcing member for reinforcing the a restraining tube made of FRP attached so as to cover a part or the whole of the outer periphery of the member in the axial direction; a filler material filled inside the restraint tube; A reinforcing member comprising:

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