CFRP bars and CFRP-reinforced concrete structures

Abstract

To provide a CFRP reinforcement which is more excellent in constructibility than before, and a reinforced concrete structure which is constructed using the CFRP reinforcement.SOLUTION: There is provided a CFRP reinforcement formed by CFRP. The CFRP reinforcement includes a mating groove portion capable of mating and connecting with a CFRP reinforcement provided adjacent to the CFRP reinforcement, and the mating groove portion is formed on at least one end face among end faces parallel to a connecting direction of the CFRP reinforcement.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to CFRP (carbon fiber reinforced plastic) bars and reinforced concrete structures constructed using CFRP bars. [Background technology]

[0002] In the past, in the reinforcement of civil engineering structures, in order to prevent column buckling and provide shear reinforcement, circular ties were used to surround part of the main reinforcement bars, and multiple circular ties were placed so that the projected cross sections of the circular ties overlapped. This type of reinforcement is called "interlocking reinforcement," and as can be seen from the dashed line in Figure 12, it was time-consuming and had the problem of low work efficiency.

[0003] To solve the above problems, Patent Document 1 proposes a structure in which a group of circular ties is arranged with another group of circular ties so that their cross sections do not overlap, and "link reinforcement" is installed to connect these groups of circular ties (see the center part of Figure 12). This reduces the construction work without compromising the shear strength of the structure. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2004-316180 Summary of the Invention [Problem to be solved by the invention]

[0005] However, in the above-mentioned conventional technology, when looking at individual circular ties, the circular ties are not physically connected to each other, so it is necessary to place multiple main bars where the projected cross sections of each circular tie overlap, and to transfer the load borne by one circular tie to another circular tie. As a result, it is necessary to install more main bars than are structurally required from the perspective of bending strength, which still requires a lot of construction work.

[0006] In view of the above-mentioned problems, the present invention aims to provide CFRP reinforcement and a reinforced concrete structure constructed using CFRP reinforcement that are easier to work than conventional reinforcement structures. [Means for solving the problem]

[0007] (1) A CFRP reinforcement formed from CFRP, characterized in that the CFRP reinforcement has a fitting groove portion that can fit into and connect with a CFRP reinforcement arranged adjacent to the CFRP reinforcement, and the fitting groove portion is formed on at least one of the end faces parallel to the connection direction of the CFRP reinforcement.

[0008] According to the invention related to (1) above, CFRP reinforcing bars made of CFRP can be easily connected via the fitting groove. This type of connection makes it possible to impart high strength to the entire CFRP reinforcing bar as a whole, and furthermore, it makes it possible to arrange reinforcing bars without much effort in structures with various cross-sectional sizes. Furthermore, the high strength characteristics of CFRP reinforcing bars make it possible to reduce the amount of reinforcing bars used in conventional shear reinforcement and lateral restraint reinforcing bars, thereby improving workability.

[0009] (2) The CFRP reinforcement is a CFRP reinforcement according to (1) above, having any one of the following shapes: circular, arc-shaped, rectangular, polygonal, and V-shaped.

[0010] According to the invention related to (2) above, it is possible to omit the main reinforcement that was conventionally placed in the overlapping portions of the circular ties of the "interlocking reinforcement" as shown in Fig. 12, for example, as shown in Fig. 7. That is, even if the reinforcing bars that were conventionally placed for reinforcement are omitted, it is possible to obtain high strength characteristics and improve workability. Furthermore, since it is possible to connect any number of CFRP reinforcements of the present invention in a series, which have various shapes, it is possible to use the CFRP reinforcements of the present invention in accordance with the cross sections of various structures, thereby improving workability.

[0011] (3) The CFRP reinforcement is a CFRP reinforcement according to (1) or (2) above, in which a plurality of the fitting grooves are formed and at least one fitting groove is open in the opposite direction to the other fitting grooves.

[0012] According to the invention related to (3) above, by forming at least one fitting groove portion so that it opens in the opposite direction to the other fitting groove portions, the connected multiple CFRP bars are less likely to come off and can be made more integrated.

[0013] (4) The CFRP reinforcement is a CFRP reinforcement according to any one of (1) to (3) above, which is provided with dowel holes passing through the CFRP reinforcement.

[0014] According to the invention related to (4) above, concrete dowels are formed by dowel holes that penetrate from the outer peripheral surface to the inner peripheral surface of the CFRP reinforcement, making it possible to ensure extremely high bond strength with concrete.

[0015] (5) The CFRP reinforcement is a CFRP reinforcement according to any one of (1) to (4) above, which is obtained by cutting a CFRP product having a hollow cross section.

[0016] According to the invention related to (5) above, it is possible to manufacture CFRP reinforcement by cutting CFRP products with hollow cross sections, such as CFRP high-pressure gas tanks scheduled for disposal, which allows for the procurement of materials at low cost and leads to the effective use of resources.

[0017] (6) A CFRP reinforced concrete structure comprising: a main reinforcement, a plurality of CFRP reinforcement bars formed by CFRP, and concrete covering the main reinforcement and the CFRP reinforcement bars, wherein the plurality of CFRP reinforcement bars are continuously connected via mating grooves formed in the CFRP reinforcement bars and are arranged in the axial direction of the main reinforcement bars.

[0018] According to the invention related to (6) above, it is possible to easily connect multiple CFRP reinforcing bars formed from CFRP via mating grooves. This type of connection makes it possible to impart high strength to the entire CFRP reinforcing bar. Furthermore, it becomes possible to arrange reinforcing bars easily in structures with various cross-sectional sizes. Furthermore, the high strength characteristics of CFRP reinforcing bars make it possible to reduce the amount of reinforcing bars used in conventional shear reinforcement and lateral restraint reinforcing bars, thereby improving workability.

[0019] (7) A CFRP reinforced concrete structure according to (6) above, in which the plurality of CFRP reinforcements are continuously connected in a ring shape and arranged in the axial direction of the main reinforcement.

[0020] According to the invention related to (7) above, it is possible to use multiple CFRP reinforcements as tie reinforcements by connecting them continuously in a ring shape and arranging them in the axial direction of the main reinforcements.

[0021] (8) A concrete structure reinforced with CFRP bars as described in (7) above, in which a restraining member capable of preventing the CFRP bars connected continuously in a ring shape from spreading outward is provided across the connection part of the CFRP bars and the connection part of the CFRP bars located opposite to the connection part.

[0022] According to the invention related to (8) above, by providing a restraining member at the connection part of the CFRP reinforcement, it becomes possible to prevent the arc-shaped CFRP reinforcement from spreading outward, and this effect can be obtained by providing it in places where toughness is particularly required. [Brief explanation of the drawings]

[0023] [Figure 1] FIG. 1 is a perspective view showing a connection mode of a CFRP bar in one embodiment of the present invention. [Figure 2] FIG. 1 is a perspective view showing a connection mode of arc-shaped CFRP bars and a connection mode of circular CFRP bars in one embodiment of the present invention. [Figure 3]In one embodiment of the present invention, (a) is a diagram illustrating the cross-sectional configuration of a CFRP bar, and (b) is a diagram illustrating an example of a method for manufacturing a CFRP bar. [Figure 4] FIG. 1 is a diagram illustrating a method for cutting out a CFRP bar, as an example of a method for manufacturing a CFRP bar. [Figure 5] 1A and 1B are diagrams illustrating an example of a manufacturing method for CFRP bars, in which (a) shows the position where a fitting groove is formed in an arc-shaped CFRP bar, and (b) shows the position where a fitting groove is formed in a circular CFRP bar. [Figure 6] FIG. 1 is a diagram illustrating an example of the effect of the CFRP reinforcement of the present invention. [Figure 7] 1(a) to 1(c) are plan views showing arrangements of the CFRP reinforcement of the present invention when it is used as a hoop reinforcement. [Figure 8] 1(a) and 1(b) are plan views showing the arrangement of the CFRP reinforcement of the present invention as a hoop reinforcement. [Figure 9] 1(a) and 1(b) are plan views showing the arrangement of restraining members when the CFRP reinforcement of the present invention is used as a hoop reinforcement. [Figure 10] FIG. 2(a) is a perspective view showing a connection mode of CFRP bars in another embodiment of the present invention, and FIG. 2(b) is a perspective view showing a shape of CFRP bars in another embodiment of the present invention. [Figure 11] 10A to 10C are diagrams illustrating a method for manufacturing a CFRP bar according to another embodiment of the present invention. [Figure 12] FIG. 1 is a diagram illustrating a conventional technique. DETAILED DESCRIPTION OF THE INVENTION

[0024] Hereinafter, one embodiment of the CFRP reinforcement and a reinforced concrete structure constructed using the CFRP reinforcement of the present invention will be described with reference to the drawings. The CFRP reinforcement of this embodiment is mainly made of carbon fiber reinforced plastic (hereinafter referred to as "CFRP").

[0025] FIG. 1 shows a connection mode of CFRP bars 1 in an embodiment of the present invention, and is a perspective view showing a circular CFRP bar 1a and multiple arc-shaped CFRP bars 1b connected in series.

[0026] 2(a) shows the structure and connection method of an arc-shaped CFRP hoop 1b, and FIG. 2(b) shows the structure and connection method of an annular CFRP hoop 1a. As shown in FIG. 2(a), the arc-shaped CFRP hoop 1b of this embodiment has a fitting groove 11 formed therein that can fit into and connect with an arc-shaped CFRP hoop 1b or an annular CFRP hoop 1a that is provided adjacent to the arc-shaped CFRP hoop 1b, and the fitting groove 11 is formed on the end face of the arc-shaped CFRP hoop 1b that is parallel to the connection direction.

[0027] In this embodiment, the fitting grooves 11 formed in the arc-shaped CFRP bars 1b are formed on both end faces parallel to the connecting direction of the arc-shaped CFRP bars 1b, one fitting groove 11 formed on each end face, and are formed so that they open in opposite directions. Note that two fitting grooves 11 may be formed on one end face, and the fitting grooves 11 may be formed so that the opening directions of the fitting grooves 11 are the same. However, opening in opposite directions makes it difficult for other arc-shaped CFRP bars 1b or annular CFRP bars 1a to be fitted into the fitting grooves 11 to come off, thereby achieving a more integrated structure. Furthermore, applying a known adhesive to the fitting grooves 11 allows the arc-shaped CFRP bars 1a to be firmly connected.

[0028] 2(b), the annular CFRP bar 1a of this embodiment has four fitting grooves 11. That is, the fitting grooves 11 are formed so that they can fit into and connect with the arc-shaped CFRP bar 1b and the annular CFRP bar 1a that are provided adjacent to the annular CFRP bar 1a, and the fitting grooves 11 are formed on the end faces of the annular CFRP bar 1a that are parallel to the connection direction.

[0029] The fitting grooves 11 formed in the annular CFRP reinforcement 1a of this embodiment are formed at opposing positions on the center line of the annular CFRP reinforcement 1a and on a center line perpendicular to the center line. Furthermore, each fitting groove 11 is formed so as to open in opposite directions on one end face and the other end face on each center line.

[0030] Although four fitting grooves 11 may be formed on one end face and all opening in the same direction, by making the opening direction of at least one fitting groove 11 open in the opposite direction to the other fitting grooves 11, other arc-shaped CFRP reinforcement 1b and annular CFRP reinforcement 1a fitted into the fitting groove 11 become less likely to come off, and they can be more integrated. In addition, by applying a known adhesive to the fitting groove 11, the annular CFRP reinforcement 1a can be firmly connected.

[0031] Furthermore, when connecting annular CFRP bars 1a by fitting them together, at least the opening directions of the fitting grooves 11 at the connecting portions must be in the same direction.

[0032] Figure 3(a) shows the cross-sectional structure of a CFRP bar 1 (including 1a, 1b, and 1b') of this embodiment. That is, a resin liner 15 of a predetermined thickness is formed on the inner peripheral surface 13 of the CFRP bar 1, and a layer of CFRP 16 is formed on the outer periphery of that. Furthermore, a layer of glass fiber reinforced plastic (hereinafter referred to as "GFRP") 17 is formed on the outer periphery of that.

[0033] The material strength of CFRP is generally 6 to 10 times that of deformed steel bar SD345, so by using the CFRP bar 1 of this embodiment, it is possible to reduce the amount of reinforcement required, such as conventional shear reinforcement bars and lateral restraint bars, thereby improving workability.

[0034] Next, Fig. 3(b) shows an example of a manufacturing method for the CFRP bar 1 of this embodiment. Explaining in more detail, first, resin or the like is poured into a mold to form a cylindrical liner 15 with a predetermined inner diameter and a predetermined length. Then, CFRP 16 impregnated with epoxy resin is helically wound around the outer surface of the liner.

[0035] Furthermore, GFRP17 carbon fiber bundles impregnated with epoxy resin are wound around the outer surface of the CFRP16, and hot air is applied to harden the CFRP16 and GFRP17. With this structure, the CFRP16 exhibits extremely high strength, and the GFRP17 on its outer periphery provides strong protection for the CFRP16.

[0036] In this way, a three-layered cylindrical body 20 is formed as shown in Figure 3(b). The hardened cylindrical body 20 is then cut into rings at predetermined intervals (see the dashed-dotted cutting lines in the figure) according to the width dimensions of the required CFRP reinforcements 1, 1a. In this way, multiple CFRP reinforcements 1 can be produced from a single cylindrical body 20.

[0037] Figure 4 shows a perspective view of a CFRP bar 1 cut out to a width (D) of 50 mm, a thickness (t) of 25 mm, and a diameter (W) of 300 mm. The circular CFRP bar 1a of this embodiment can be obtained by forming a fitting groove 11 in the CFRP bar 1 shown in the figure. The CFRP bar 1 can also be cut at a position 120° from the center (shown by the dashed lines in the figure), divided into three equal parts, and the fitting grooves 11 formed therein to obtain the arc-shaped CFRP bar 1b of this embodiment.

[0038] The arc-shaped CFRP reinforcement 1b of this embodiment is not necessarily limited to cutting a circular CFRP reinforcement into three equal parts, but may be cut at any position. For example, a C-shaped CFRP reinforcement 1b' shown in Figure 8(a) is also included in the arc-shaped CFRP reinforcement 1b of the present invention.

[0039] Next, Figure 5(a) shows the positional relationship of the fitting grooves 11 formed in the arc-shaped CFRP reinforcement 1b. The fitting grooves 11 are formed by cutting the CFRP reinforcement 1 before or after dividing it into thirds. In this embodiment, the fitting grooves 11 are 25 mm in both width and depth. As mentioned above, the opening directions of the two fitting grooves 11 formed in each arc-shaped CFRP reinforcement 1b are opposite to each other.

[0040] As shown in the figure, the two fitting grooves 11 formed in each arc-shaped CFRP bar 1b are positioned at a 90° angle from the center of the circular CFRP bar 1, so that when multiple arc-shaped CFRP bars 1b are connected, the two arc-shaped CFRP bars 1b always intersect at right angles, allowing for greater anchorage. In the arc-shaped CFRP bars 1b of this embodiment formed as described above, only the cut portions of the fitting grooves 11 are discarded, making it possible to reduce material loss and economically manufacture the arc-shaped CFRP bars 1b.

[0041] 5(b) shows the positional relationship of the fitting grooves 11 formed in the annular CFRP reinforcement 1a. The fitting grooves 11 are formed by cutting and have a width and depth of 25 mm. As described above, the fitting grooves 11 formed in the annular CFRP reinforcement 1a are formed at opposing positions on the center line (dashed line in the figure) of the annular CFRP reinforcement 1a and on a center line (dashed line in the figure) perpendicular to the center line. Furthermore, each fitting groove 11 is formed so that it opens in opposite directions on one end face (solid line in the figure) and the other end face (dashed line in the figure) on each center line.

[0042] As shown in Figure 6, the arc-shaped CFRP bars 1b connected continuously via the fitting grooves 11 each have an arc shape, which allows them to efficiently restrain the concrete of the structure 50. In addition, an anchoring part 14 is formed from the fitting grooves 11, which form the connection part, to the side end of the arc-shaped CFRP bars 1b when connected, as shown in the figure, which allows for sufficient adhesion to the concrete.

[0043] Next, an embodiment of a reinforced concrete structure constructed using the above-mentioned CFRP reinforcement 1 (including 1a, 1b, and 1b') will be described.

[0044] 7(a) to 7(c) are cross-sectional views showing an example of the arrangement of CFRP reinforcements 1 in a structure 50. As shown in Fig. 7(a) and (b), a circular CFRP reinforcement 1a and multiple arc-shaped CFRP reinforcements 1b can be continuously connected in a circular shape via fitting grooves 11 and arranged at predetermined intervals as ties in the axial direction of the main reinforcement 2.

[0045] 7(c), it is also possible to connect annular CFRP reinforcements 1a continuously via mating grooves 11 and place them at predetermined intervals as ties in the axial direction of the main reinforcement 2. In this way, a reinforced concrete structure constructed using the CFRP reinforcement 1 of the present invention does not require the installation of "interlocking reinforcement" or "link reinforcement" as in the conventional technology of FIG. 12, making it possible to significantly reduce the amount of reinforcement and improve workability.

[0046] 8(a) shows a cross-sectional view of an example of the arrangement of CFRP bars 1 in a structure 50 with an even larger cross section. As shown in the dashed line in FIG. 8(a), it is also possible to use a C-shaped arc-shaped CFRP bar 1b', and this configuration makes it possible to improve the unity and strength of the multiple connected CFRP bars 1.

[0047] Figure 8(b) shows a cross-sectional view of an example of the arrangement of CFRP reinforcing bars 1 in a structure 50 with an even larger cross-section (approximately 2 m × 1.2 m) than that shown in Figure 8(a). As shown in the figure, by arranging CFRP reinforcing bars 1 in the middle part of the cross-section, it is possible to accommodate a structure 50 with a large cross-section. As shown by the dashed line, arc-shaped CFRP reinforcing bars 1b may be arranged on both sides or only on one side. In this way, it is possible to connect circular CFRP reinforcing bars 1a or multiple arc-shaped CFRP reinforcing bars 1b continuously in a circular shape and arrange them at predetermined intervals as ties in the axial direction of the main reinforcing bars (not shown).

[0048] As described above, in the reinforced concrete structure with CFRP bars of the present invention, the annular CFRP bars 1a shown in Figures 7 and 8 are physically connected to each other so as to interlock with each other via the fitting grooves 11, so that the load borne by one annular CFRP bar 1a can be transmitted to other annular CFRP bars 1a via the arc-shaped CFRP bars 1b. Therefore, there is no longer any need to install main bars, which were previously required for load transmission as shown in Figure 12, and it is possible to significantly reduce the amount of work required for reinforcement arrangement.

[0049] In addition, the CFRP bars of the present invention are made from carbon fiber reinforced plastic, which is stronger than steel, so the amount of carbon fiber reinforced plastic used can be reduced, which in turn makes it possible to significantly reduce material costs and construction labor.

[0050] (Another embodiment) The CFRP reinforcement bars and reinforced concrete structures constructed using the CFRP reinforcement bars of the present invention have been described above, but the present invention is not necessarily limited to the above-described embodiments, and the following modifications are possible.

[0051] 9(a) and 9(b), it is possible to provide a restraining member 30 that can prevent the arc-shaped CFRP bars 1b from spreading outward, spanning from the connection part of the arc-shaped CFRP bars 1b to the connection part of the opposite arc-shaped CFRP bars 1b. Of course, when annular CFRP bars 1a are connected in series, it is also possible to provide the restraining member 30 across the connection part.

[0052] As the restraint member 30, in addition to reinforcing bars and PC steel bars, rod-shaped CFRP bars can be used. Furthermore, it is preferable that the ends of the restraint member 30 be mechanically fixed, but hooks are also possible. The restraint member 30 can be more effective when installed in places where high toughness is particularly required.

[0053] As shown in Figure 10(a), it is also possible to provide a reinforcing sheet 19 at the connection of the arc-shaped CFRP bars 1b. For example, the connection can be reinforced by placing a CFRP sheet and impregnating and curing it with epoxy resin. Of course, it is also possible to reinforce the connection of the ring-shaped CFRP bars 1a with the reinforcing sheet 19.

[0054] In addition, as shown in Fig. 10(a), dowel holes 18 may be formed in the CFRP bars 1 (including 1a, 1b, and 1b') that penetrate from the outer peripheral surface 12 to the inner peripheral surface 13 of the CFRP bars 1. In this way, after the concrete for the structural body is poured, the dowel holes 18 form concrete dowels.

[0055] More specifically, the CFRP bar 1 of this embodiment obtained by the above-mentioned manufacturing method has smooth cut surfaces, outer peripheral surface 12, and inner peripheral surface 13. Therefore, by drilling dowel holes 18 in the CFRP bar 1, it is possible to improve the bond strength with concrete.

[0056] As mentioned above, the CFRP reinforcement 1 of this embodiment is cut out from a cylinder 20 in which CFRP 16 is wound helically. Therefore, even if dowel holes 18 are drilled, the fibers inserted freely in all directions allow the reinforcement to firmly maintain its shape.

[0057] In the above-described embodiment, the method of manufacturing the CFRP bar 1 and applying it to a concrete structure has been described. However, it is not necessarily limited to CFRP, and for example, the main constituent material can be high-strength glass fiber or aramid fiber, and the same manufacturing method and application to a concrete structure as the above-described CFRP bar 1 can be realized.

[0058] Furthermore, while the CFRP reinforcement 1 described above has a three-layer structure consisting of a liner 15, CFRP 16, and GFRP 17, it is not necessarily limited to this cross-sectional structure, and the effects of the present invention can be achieved with any structure that is primarily composed of at least CFRP 16. Similarly, it goes without saying that the CFRP reinforcement 1 of the present invention does not necessarily have to be wound helically to obtain the CFRP reinforcement 1 of the present invention.

[0059] Furthermore, the liner 15 is not necessarily limited to being made of resin, but can also be made of materials other than resin, such as metal. In addition, the liner 15 is not necessarily limited to being made using a mold, but can also be made by extrusion molding. Note that the liner 15 is not essential for the CFRP reinforcement of the present invention, and it can be removed for use, or it can be used as a CFRP reinforcement even if it is molded without the liner 15.

[0060] In addition, in order to improve the bond strength between the CFRP bar 1 and concrete, the outer peripheral surface 12, inner peripheral surface 13, and end faces (cross-sections) parallel to the connection direction of the CFRP bar 1 may be roughened or provided with irregularities. Note that since the fiber direction is circumferential, it is easier to roughen or provide irregularities on the end faces (cross-sections) parallel to the connection direction of the CFRP bar 1, and this also ensures adhesion performance, so processing the end faces (cross-sections) parallel to the connection direction of the CFRP bar 1 is more preferable.

[0061] In addition, in the embodiments shown in Figures 7 and 8, multiple arc-shaped CFRP reinforcements 1b are connected in a ring shape and used as hoop reinforcement, but this is not necessarily the only possible arrangement. For example, multiple arc-shaped CFRP reinforcements 1b can be connected in a straight line and used as an alternative to steel bars.

[0062] In the above-described embodiment shown in Figures 1 and 2, two fitting grooves 11 are formed in the arc-shaped CFRP bar 1b, and four fitting grooves 11 are formed in the annular CFRP bar 1a, but this is not necessarily limited to this form, and the formation positions and number of the fitting grooves 11 can be changed as appropriate.

[0063] The CFRP reinforcement 1 (including 1a, 1b, and 1b') of the present invention can be applied to various structures such as columns and walls having cross sections as shown in Figures 7 and 8, as well as beams and slabs, making it possible to reduce the amount of reinforcement as mentioned above and improve workability.

[0064] In the above-described embodiment, the CFRP reinforcement 1 is manufactured by molding a hardened cylindrical body 20 and then cutting it, but this is not necessarily limited to this embodiment, and the CFRP reinforcement 1 may be molded into a desired shape from the beginning. Of course, the cross section of the cylindrical body 20 is not limited to a circular cross section, and the CFRP reinforcement 1 may be manufactured by molding a hollow body with a rectangular or polygonal cross section and then cutting it.

[0065] Furthermore, in the above-described embodiment, circular and arc-shaped CFRP reinforcements 1 (1a, 1b, 1b') are exemplified, but the shape is not necessarily limited to these. It is also possible to use a L-shaped CFRP reinforcement 1c as shown in Figure 10(b), and it is also possible to use a CFRP reinforcement 1 (not shown) that is not limited to a circular shape but is rectangular or polygonal.

[0066] (Reusing CFRP high-pressure gas tanks) In the above-described embodiment, a form of newly manufacturing CFRP reinforcement 1 has been described, but the CFRP reinforcement of the present invention can also be manufactured by reusing CFRP high-pressure gas tanks (waste high-pressure tanks) that are scheduled to be discarded and can be filled with hydrogen or the like.

[0067] Fig. 11 shows a schematic cross-sectional view of a CFRP high-pressure gas tank 100. As with the above-described embodiment, the CFRP high-pressure gas tank 100 has a cross-sectional configuration as shown in Fig. 3(a). Therefore, according to the required width dimension of the CFRP reinforcement 1, it is possible to cut the tank along the dashed dotted line shown in the figure, cut out multiple CFRP reinforcement 1, and then further cut and process it to produce an arc-shaped CFRP reinforcement 1b.

[0068] According to the Basic Act on High Pressure Gas, CFRP high-pressure gas tanks 100 must be disposed of after 15 years even if there is no deterioration. Therefore, by manufacturing CFRP reinforcement 1 from CFRP high-pressure gas tanks 100 scheduled for disposal as described above, it is possible to procure materials at low cost and to make effective use of resources.

[0069] On the other hand, CFRP high-pressure gas tanks 100 with various sizes (diameters) are not available, and since the manufacturing method involves slicing a CFRP high-pressure gas tank 100 to be discarded into rings to cut out annular CFRP reinforcement 1, it is only possible to cut out annular CFRP reinforcement 1 with a certain size (diameter). However, as mentioned above, by cutting annular CFRP reinforcement 1a to cut out arc-shaped CFRP reinforcement 1b and connecting multiple of these, it becomes possible to apply the method to a structure 50 with a cross section of any size.

[0070] The above embodiment describes one mode of reusing a CFRP high-pressure gas tank (abandoned high-pressure tank). However, the CFRP reinforcement 1 is not necessarily limited to CFRP high-pressure gas tanks (abandoned high-pressure tanks). In other words, not only tank products that store high-pressure gas, but also tank products that store low-pressure gas or liquid, and even products that have a hollow cylindrical shape and whose main constituent material is CFRP, can be manufactured into CFRP reinforcement 1 using the same recycling method as the CFRP high-pressure gas tank (abandoned high-pressure tank) described above. Furthermore, the cross-sectional shape is not limited to cylindrical. As long as the product has a hollow cross section, it can also be cut into an elliptical, rectangular, polygonal, oval, or other shape, and the CFRP reinforcement of the present invention can be manufactured by cutting. Furthermore, it is naturally possible to manufacture the CFRP reinforcement of the present invention by cutting CFRP products of various shapes, such as domes and plates, not just those with hollow cross sections.

[0071] The scope of the present invention is defined by the claims rather than the description of the above embodiments, and includes all modifications within the meaning and scope of the claims. Furthermore, the specific materials, dimensions, shapes, etc. described in the above embodiments can be modified within the scope of solving the problems of the present invention. [Explanation of symbols]

[0072] 1 CFRP muscle 2 Main reinforcement 1a Circular CFRP bar 1b Arc-shaped CFRP reinforcement 1b' C-shaped arc-shaped CFRP reinforcement 1c L-shaped CFRP bar 11 Fitting groove 12 Outer surface 13 Inner surface 14 Fixing section 15 Liner 16 CFRP 17 GFRP 18 Dowel hole 19 Reinforcement sheet 20 Cylinder 30 Restraining member 50 structure 100 CFRP high-pressure gas tank (abandoned high-pressure tank)

Claims

1. A CFRP muscle formed by CFRP, The CFRP reinforcement has a fitting groove that can be fitted with and connected to a CFRP reinforcement provided adjacent to the CFRP reinforcement, The fitting groove is formed on at least one end face of the end faces parallel to the connection direction of the CFRP reinforcement, The CFRP reinforcement has any one of a circular, arc-shaped, rectangular, polygonal, and dogleg-shaped shape. CFRP muscle characterized by:

2. A CFRP muscle formed by CFRP, The CFRP reinforcement has a fitting groove that can be fitted with and connected to a CFRP reinforcement provided adjacent to the CFRP reinforcement, The fitting groove is formed on at least one end face of the end faces parallel to the connection direction of the CFRP reinforcement, The CFRP reinforcement has a plurality of fitting grooves formed therein, and at least one fitting groove is open in the opposite direction to the other fitting grooves. CFRP muscle characterized by:

3. A CFRP muscle formed by CFRP, The CFRP reinforcement has a fitting groove that can be fitted with and connected to a CFRP reinforcement provided adjacent to the CFRP reinforcement, The fitting groove is formed on at least one end face of the end faces parallel to the connection direction of the CFRP reinforcement, The CFRP reinforcement has dowel holes that penetrate the CFRP reinforcement. CFRP muscle characterized by:

4. A CFRP muscle formed by CFRP, The CFRP reinforcement has a fitting groove that can be fitted with and connected to a CFRP reinforcement provided adjacent to the CFRP reinforcement, The fitting groove is formed on at least one end face of the end faces parallel to the connection direction of the CFRP reinforcement, The CFRP reinforcement is a product made of CFRP with a hollow cross section, which is cut and processed. CFRP muscle characterized by:

5. The concrete structure includes a main reinforcement, a plurality of CFRP reinforcement bars formed by CFRP, and concrete covering the main reinforcement and the CFRP reinforcement bars, The plurality of CFRP reinforcements are continuously connected via fitting grooves formed in the CFRP reinforcements and are arranged in the axial direction of the main reinforcements. A reinforced concrete structure using CFRP bars.

6. The plurality of CFRP reinforcements are connected continuously in a ring shape and arranged in the axial direction of the main reinforcement. A concrete structure reinforced with CFRP bars according to claim 5.

7. A restraining member is provided across the connection portion of the CFRP reinforcement and the connection portion of the CFRP reinforcement opposite to the connection portion, which can prevent the circularly connected CFRP reinforcement from spreading outward. A concrete structure reinforced with CFRP bars according to claim 6.

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