Anchorages and prestressed concrete

Abstract

[Problem] A wedge-type fixing implement according to the present invention has sufficient strength against diameter-expansion deformation in a barrel member resulting from a wedge action, without the barrel member causing any corrosion problems. [Solution] The present invention includes: a barrel member 12 that is constituted by resin or mortar and has tapered through-holes 14; a plurality of wedge members 20 that have tapered outer circumferential surfaces 20A which slide into inner circumferential surfaces 14A of the through-holes 14, and that work together to grip a wire 110; and fibers 16 that serve as reinforcing members extending in the circumferential direction of the barrel member in order to suppress radius-expansion deformation of the barrel member 12.

Description

[Technical Field]

[0001] The present invention relates to an anchor and prestressed concrete (PC), and more particularly to an anchor used for tensioning wires in prestressed concrete and prestressed concrete. [Background technology]

[0002] A known fastening device used to tension wires (cables, rods) in PC is a wedge-type fastening device that has a barrel member (sleeve member) with a tapered through hole fixed to the PC concrete block, and multiple wedge members that each have a tapered outer surface that slides against the inner surface of the through hole and work together to clamp the wire (for example, Patent Document 1).

[0003] In this wedge-type fastener, the barrel member is fixed to the concrete block, and the wedge members are pushed into the tapered side of the through-hole, causing a wedge action that clamps, or fixes, the end of the wire by the multiple wedge members. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 11-210163 Summary of the Invention [Problem to be solved by the invention]

[0005] Conventionally known common wedge-type fasteners include those with a steel barrel member and those with a resin barrel member. Those with a steel barrel member have sufficient strength to withstand the wedge action causing the barrel member to expand and deform, but may corrode (rust) depending on the environmental conditions. Those with a resin barrel member are not susceptible to corrosion, but are less likely to have sufficient strength to withstand the wedge action causing the barrel member to expand and deform.

[0006] The problem to be solved by the present invention is to provide a wedge-type fastener in which the barrel member is free from corrosion and has sufficient strength to resist deformation of the barrel member that is caused by the wedge action to expand in diameter. [Means for solving the problem]

[0007] A fixing device according to one embodiment of the present invention is a fixing device (10) for the end of a wire (110), and comprises a barrel member (12) made of resin or mortar and having a tapered through hole (14), a plurality of wedge members (20) each having a tapered outer peripheral surface (20A) that slides against the inner peripheral surface (14A) of the through hole and cooperates with each other to clamp the wire, and reinforcing members (16, 52, 60, 70) that include a portion extending circumferentially of the barrel member to suppress radial expansion and deformation of the barrel member.

[0008] According to this configuration, the barrel member does not corrode, and has sufficient strength to resist deformation of the barrel member that causes expansion of its diameter due to wedging action.

[0009] In the above-described fixing tool, each wedge member is preferably made of resin or fiber-reinforced resin.

[0010] With this configuration, the wedge member does not corrode.

[0011] In the above-mentioned fastener, the reinforcing member preferably includes fibers (16, 52) embedded in the barrel member.

[0012] According to this configuration, the barrel member and the reinforcing member can be integrally molded, and the productivity of the fixing tool is good.

[0013] In the above-described fixing device, preferably, the barrel member is made of prepreg (42, 44, 46, 48) wound cylindrically to have an outer peripheral surface (42A, 44A, 46A, 48A) that tapers stepwise in the same direction as the tapered shape of the through hole, the prepreg including a resin base material (50) and fibers (52) impregnated in the base material, and the reinforcing member is made of the fibers contained in the prepreg.

[0014] According to this configuration, the barrel member including the reinforcing member can be manufactured efficiently using prepregs, resulting in good productivity. In addition, the wall thickness of the barrel member can be made nearly uniform over the entire axial length, thereby enabling the barrel member to be made smaller and lighter.

[0015] In the above-described fixing tool, the prepreg is preferably made up of a plurality of strips arranged so as to overlap one another in the radial direction at a portion of the axial direction of the through hole.

[0016] According to this configuration, the barrel member can be reliably formed into the required shape using prepreg.

[0017] In the fixing device, the reinforcing member preferably includes an annular body (30) provided on the outer periphery of the barrel member so as to surround the barrel member.

[0018] According to this configuration, the annular body effectively suppresses the expansion of the diameter of the barrel member, and the barrel member is effectively suppressed from deforming due to the wedge action.

[0019] In the above-described fixing tool, the barrel member is preferably made of fiber reinforced resin, and the annular body is preferably made of fiber reinforced resin having a higher Young's modulus than the fiber reinforced resin that makes up the barrel member.

[0020] According to this configuration, the radial expansion deformation of the barrel member is reliably suppressed by the annular body, and material costs can be reduced compared to when the barrel member is made of a fiber-reinforced resin having a high Young's modulus.

[0021] In the fixing tool, the annular body is preferably provided partially in the axial direction of the through hole.

[0022] This configuration reduces material costs compared to when the annular body is provided over the entire axial length of the through hole.

[0023] In the fixing device, the annular body is preferably provided continuously over the entire axial direction of the through hole.

[0024] According to this configuration, the radial expansion deformation of the barrel member is reliably suppressed.

[0025] In the above-described fixing device, preferably, the barrel member has a cylindrical outer peripheral surface (12C), and the reinforcing member includes a spiral constraint (60) wound around the outer peripheral surface of the barrel member.

[0026] According to this configuration, the spiral restraining body effectively restrains the barrel member from expanding in diameter, and the barrel member is effectively restrained from deforming in diameter due to the wedge action.

[0027] In the above-described fixing tool, the barrel member is preferably made of fiber reinforced resin, and the spiral restraint body is preferably made of fiber reinforced resin having a higher Young's modulus than the fiber reinforced resin that makes up the barrel member.

[0028] According to this configuration, the expansion and deformation of the barrel member is reliably suppressed, and material costs can be reduced compared to when the barrel member is made of a fiber-reinforced resin having a high Young's modulus.

[0029] In the above fixing tool, preferably, the barrel member has a spiral groove (12D) on the outer circumferential surface, and the spiral restraint body is fitted into the spiral groove.

[0030] According to this configuration, the helical restraining body is prevented from moving in the axial direction relative to the barrel member, and the effect of the helical restraining body in preventing the radial expansion deformation of the barrel member is stabilized.

[0031] In the above-described fixing device, preferably, the barrel member has a conical outer peripheral surface (12E), and the reinforcing member includes an annular restraining body (70) fitted onto the outer peripheral surface of the barrel member.

[0032] According to this configuration, the annular restraining body acts on the barrel member to suppress radial expansion, and the barrel member is suppressed from deforming due to its wedge action.

[0033] In the above-described fixing tool, the barrel member is preferably made of fiber reinforced resin, and the annular restraining body is preferably made of fiber reinforced resin having a higher Young's modulus than the fiber reinforced resin that makes up the barrel member.

[0034] According to this configuration, the expansion and deformation of the barrel member is reliably suppressed, and material costs can be reduced compared to when the barrel member is made of a fiber-reinforced resin having a high Young's modulus.

[0035] In the above-described fixing tool, preferably, the annular restraining body includes a surface on the tapered end surface (70B) of the conical shape of the barrel member that is perpendicular to the axial direction of the barrel member.

[0036] With this configuration, when the barrel member is embedded in a concrete block of prestressed concrete, the barrel member is prevented from moving axially relative to the concrete block, stabilizing the action of the fixing device in the prestressed concrete.

[0037] Prestressed concrete according to one embodiment of the present invention comprises a rectangular parallelepiped concrete block, a wire passing through the concrete block in the longitudinal direction, and anchors according to the above-described embodiment provided at both longitudinal ends of the concrete block and engaging the ends of the wire.

[0038] This configuration allows a stable prestress state to be maintained for a long period of time, and provides excellent durability.

[0039] The prestressed concrete may be either one in which the fixing device is embedded in the concrete block, or one in which one end face (12B) of the barrel member abuts against the end face of the concrete block and the outer circumferential surface (12C, 12E) of the barrel member is attached to the concrete block so as to be exposed outward. [Effects of the Invention]

[0040] According to the fastener of the present invention, the barrel member is not corroded and has sufficient strength to resist deformation of the barrel member that causes expansion of its diameter due to wedging action. [Brief explanation of the drawings]

[0041] [Figure 1] 1 is a cross-sectional view showing a first embodiment of the prestressed concrete and anchor according to the present invention; [Figure 2] Cross-sectional view of a main part of prestressed concrete having an anchor according to embodiment 1 [Figure 3] Cross-sectional view of a main part of prestressed concrete having an anchor according to embodiment 2 [Figure 4] Cross-sectional view of a main part of prestressed concrete having an anchor according to embodiment 3 [Figure 5] Cross-sectional view of a main part of prestressed concrete having an anchor according to embodiment 4 [Figure 6] 10A and 10B are cross-sectional views showing a manufacturing process of the barrel member of the fixing tool according to the fourth embodiment. [Figure 7] Partial cross-sectional view of a main part of prestressed concrete having an anchor according to embodiment 5 [Figure 8] Cross-sectional view of a main part of prestressed concrete having an anchor according to embodiment 5 [Figure 9]Partial cross-sectional view of a main part of prestressed concrete having an anchor according to embodiment 6 [Figure 10] 7 is a cross-sectional view showing a seventh embodiment of the prestressed concrete and anchoring device according to the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0042] (Embodiment 1) 1, the prestressed concrete 100 comprises a rectangular parallelepiped concrete block 102, a cylindrical resin sheath 104 embedded in the concrete block 102 so as to extend in the longitudinal direction of the concrete block 102, and a cable (wire) 106 made of fiber-reinforced resin or metal disposed in the sheath 104 and passing through the concrete block 102 in the longitudinal direction. The space between the sheath 104 and the cable 106 is filled with grout 108 such as mortar cement.

[0043] The prestressed concrete 100 further has left and right anchors 10 that are provided at both longitudinal ends (left and right ends as viewed in FIG. 1 ) of the concrete block 102 and to which ends of the cable 106 are anchored. The left and right anchors 10 sandwich the concrete block 102 from both longitudinal sides, fixing (anchoring) the cable 106 to the concrete block 102 in a tensile state. This applies prestress to the concrete block 102.

[0044] The left and right fixing devices 10 are wedge-type devices, each having a cylindrical barrel member 12 and a pair of upper and lower wedge members 20 as seen in Figure 1. Since the left and right fixing devices 10 have the same structure, the fixing device 10 located on the left side will be described below as a representative.

[0045] As shown in Figure 2, the barrel member 12 has an outer end 12A exposed outward from the concrete block 102, an inner end 12B joined to the end face 110A of the fastener burying hole 110 in the concrete block 102, and an outer peripheral surface 12C joined to the inner peripheral surface 110B of the fastener burying hole 110, and is entirely embedded in the end of the concrete block 102.

[0046] As a result, the barrel member 12 is fixed to the concrete block 102 so that it cannot be displaced in the axial direction (left and right direction as viewed in FIG. 2 ), which is the direction in which prestress is applied to the concrete block 102, or in the radial direction. The barrel member 12 may be embedded in the concrete block 102 when the concrete block 102 is being molded. By molding the concrete block 102 using the fixing device 10 as an insert member, the fixing device embedding hole 110 is formed when the concrete block 102 is being molded.

[0047] The barrel member 12 has a through hole 14 that passes through the center in the axial direction. The through hole 14 is a hole that is open at both ends and has a tapered shape that extends from the outer end 12A to the inner end 12B of the barrel member 12. In other words, the through hole 14 is a tapered hole whose inner diameter gradually decreases from the outer end 12A to the inner end 12B of the barrel member 12.

[0048] The barrel member 12 is a molded product made of resin such as epoxy resin or polyester resin. As shown in Fig. 2(A), mesh- or sheet-like fibers 16 are embedded in the barrel member 12. The fibers 16 are glass fibers, carbon fibers, boron fibers, aramid fibers, basalt fibers, or the like, and are present in the barrel member 12 in a cylindrical, multi-layered form wound around the central axis of the through-hole 14. As a result, the fibers 16 form a reinforcing member that includes a portion that extends continuously in the circumferential direction of the barrel member 12.

[0049] 2(B), the fibers 16 may be formed by winding a bundle of fibers 16 in a spiral shape with varying diameters multiple times around the central axis of the through-hole 14. In this case as well, the fibers 16 form a reinforcing member that extends continuously in the circumferential direction of the barrel member 12.

[0050] In either case, the fibers 16 increase the apparent tensile strength and Young's modulus (modulus of longitudinal elasticity) of the barrel member 12 in the radial expansion direction, and suppress radial expansion deformation of the barrel member 12. In order to effectively suppress radial expansion deformation of the barrel member 12, the fibers 16 preferably include a portion that extends continuously around the central axis of the through hole 14, but may be discontinuous depending on the required radial tensile strength and Young's modulus of the barrel member 12.

[0051] Each wedge member 20 is a molded product made of resin or fiber-reinforced resin, and has the shape of a tapered shaft split in half, with a tapered outer surface 20A that slides against the inner surface 14A of the through hole 14, and a cable groove 20B with an approximately semicircular cross-sectional shape that opens toward the split surface 20C.

[0052] The pair of wedge members 20 cooperate to clamp the end of the cable 106, which is in a tensioned state and engaged in the cable groove 20B, and by being pressed against the tapered side of the through hole 14, i.e., by being driven into the tapered side of the through hole 14, the wedge action between them and the barrel member 12 increases the frictional resistance with the cable 106, and the end of the cable 106 is engaged (anchored) to the concrete block 102 via the barrel member 12.

[0053] Due to the above-mentioned wedge action, a load that causes radial expansion deformation of the barrel member 12 acts on the barrel member 12. Under this condition, the fibers 16 act as a reinforcing member to suppress radial expansion deformation of the barrel member 12.

[0054] As a result, even if the barrel member 12 is made of resin instead of steel for rust prevention, the barrel member 12 has sufficient strength to resist deformation due to enlargement of the diameter caused by the wedge action, and loosening of the wedge action is suppressed.

[0055] Thus, according to the fixing device 10 of the first embodiment, the barrel member 12 does not corrode even with long-term use, the barrel member 12 has sufficient strength to withstand radial expansion deformation due to the wedge action, and it is possible to prevent a decrease in the fixing strength of the cable 106 due to radial expansion deformation of the barrel member 12. The wedge member 20 is also a molded product made of resin or fiber-reinforced resin, and therefore does not corrode even with long-term use.

[0056] In the fixing device 10 of the first embodiment, the fibers 16 and the barrel member 12 (base material) are integrally formed by molding the barrel member 12 containing the fibers 16, and therefore the productivity of the fixing device 10 is good.

[0057] (Embodiment 2) The fixing tool 10 of the second embodiment will be described with reference to Fig. 3. In Fig. 3, parts corresponding to those in Fig. 2 are given the same reference numerals as those in Fig. 2, and descriptions thereof will be omitted.

[0058] In the second embodiment, a plurality of annular bodies 30 are provided at predetermined intervals on the outer periphery of the cylindrical barrel member 12 in the extension direction (axial direction) of the through hole 14. When viewed in the axial direction of the through hole 14, the plurality of annular bodies 30 are provided partially on the barrel member 12. Each annular body 30 is annular and continuously goes around the outer periphery of the barrel member 12, that is, it is provided so as to completely surround the outer periphery of the barrel member 12. Each annular body 30 is integrally molded with the barrel member 12 or fitted onto the barrel member 12 afterwards.

[0059] The annular body 30 is made of a fiber-reinforced resin. Examples of fibers (not shown) contained in the fiber-reinforced resin include glass fiber, carbon fiber, boron fiber, aramid fiber, and basalt fiber. The fibers may be in a mesh or sheet form and may be wound in multiple layers cylindrically around the central axis of the through-hole 14, including a portion that extends continuously in the circumferential direction of the barrel member 12.

[0060] The fibers (not shown) contained in each annular body 30 may be bundled and wound multiple times in a spiral shape with varying diameters around the central axis of the through-hole 14. In this case, the fibers contained in the annular body 30 also include a portion that extends continuously in the circumferential direction of the barrel member 12.

[0061] Each annular body 30 acts as a reinforcing member that suppresses radial expansion and deformation of the barrel member 12 in addition to the fibers 16 embedded in the barrel member 12, making the barrel member 12 even more resistant to radial expansion and deformation.

[0062] Each annular body 30 may be made of a fiber-reinforced resin, such as carbon fiber-reinforced resin, containing high-tensile fibers that have a higher Young's modulus and tensile strength than the fibers 16 embedded in the barrel member 12. In other words, each annular body 30 is made of a fiber-reinforced resin that has a higher Young's modulus than the fiber-reinforced resin that makes up the barrel member 12. Each annular body 30 performs a reinforcing function by suppressing radial expansion and deformation of the barrel member 12 due to the high-tensile fibers contained in the fiber-reinforced resin.

[0063] As a result, even if the fixing device 10 of embodiment 2 is used for a long period of time, the barrel member 12 will not corrode. Furthermore, since the barrel member 12 has sufficient strength to resist radial expansion deformation due to the wedging action, a decrease in the fixing strength of the cable 106 caused by radial expansion deformation of the barrel member 12 is suppressed.

[0064] Even if the fibers 16 embedded in the barrel member 12 and the fibers of the fiber-reinforced resin that make up the annular bodies 30 are made of different materials and the fibers 16 are made of glass fiber, which is cheaper than the carbon fiber, etc. contained in the annular bodies 30, the high reinforcing effect of each annular body 30 provides strength (strength that suppresses radial expansion deformation of the barrel member 12) similar to that of a barrel member 12 made of high-quality carbon fiber-reinforced resin, etc. This saves (reduces) the material cost of the barrel member 12 and effectively suppresses radial expansion deformation of the barrel member 12.

[0065] Furthermore, since each annular body 30 is provided partially in the axial direction of the barrel member 12, the material cost of the annular body 30 is reduced compared to when the annular body 30 is provided continuously over the entire length of the barrel member 12.

[0066] When each annular body 30 is embedded in the concrete block 102 together with the barrel member 12, the annular end surface 30A is in contact with the concrete block 102. This increases the adhesive strength between the barrel member 12 and the concrete block 102. In other words, the end surface 30A of each annular body 30 acts as a barrier surface that prevents the barrel member 12 from moving axially relative to the concrete block 102.

[0067] This action effectively prevents the barrel member 12 from moving in the axial direction relative to the concrete block 102. As a result, high-quality prestressed concrete 100 that has been given stable prestress over a long period of time can be produced with high productivity without requiring additional parts or processes.

[0068] (Embodiment 3) The fixing tool 10 of the third embodiment will be described with reference to Fig. 4. In Fig. 4, parts corresponding to those in Fig. 3 are given the same reference numerals as those in Fig. 3, and descriptions thereof will be omitted.

[0069] (Embodiment 3) In the third embodiment, the annular body 30 is formed on the outer periphery of the barrel member 12 as a cylindrical body having an axial length substantially the same as that of the barrel member 12 .

[0070] The fibers contained in the annular body 30 preferably include a portion that continuously extends around the central axis of the through-hole 14 in order to effectively suppress radial expansion and deformation of the barrel member 12. The fibers may be mesh-like or sheet-like fibers wound in the circumferential direction, fibers wound in two directions, the circumferential direction and the axial direction, fibers bonded together, fibers woven in two directions and wound, or the like.

[0071] In this embodiment, the annular body 30 may also be made of a fiber-reinforced resin, such as a carbon fiber-reinforced resin, that contains high-tensile fibers having a higher Young's modulus and tensile strength than the fibers 16 embedded in the barrel member 12. In other words, in this embodiment, the annular body 30 is also made of a fiber-reinforced resin that has a higher Young's modulus than the fiber-reinforced resin that makes up the barrel member 12.

[0072] In this embodiment, too, the fibers 16 embedded in the barrel member 12 and the fibers of the fiber-reinforced resin that make up the annular bodies 30 are made of different materials, and even if the fibers 16 are made of glass fiber, which is cheaper than the carbon fiber, etc. contained in the annular bodies 30, the high reinforcing effect of each annular body 30 provides strength (strength that suppresses radial expansion deformation of the barrel member 12) that is close to that of a barrel member 12 made of high-quality carbon fiber-reinforced resin, etc. This reduces the material cost of the barrel member 12 and effectively suppresses radial expansion deformation of the barrel member 12.

[0073] In the third embodiment, the effect of suppressing radial expansion deformation of the barrel member 12 by the annular body 30 is obtained substantially uniformly over the entire axial length of the barrel member 12.

[0074] As a result, the fixing device 10 of embodiment 3 does not corrode the barrel member 12 even when used over a long period of time, and has sufficient strength to withstand the tendency of the barrel member 12 to expand and deform due to wedging action, thereby preventing a decrease in the fixing strength of the cable 106 due to the expansion and deformation of the barrel member 12.

[0075] (Embodiment 4) The fixing device 10 of the fourth embodiment will be described with reference to Figures 5 and 6. In Figures 5 and 6, parts corresponding to those in Figure 2 are designated by the same reference numerals as those in Figure 2, and descriptions thereof will be omitted.

[0076] As shown in FIG. 5, the barrel member 12 is made of a plurality of strip-shaped prepregs 42, 44, 46, and 48 wound into a cylindrical shape, and has outer peripheral surfaces 42A, 44A, 46A, and 48A that taper stepwise in the same direction as the tapered shape of the through hole 14.

[0077] That is, the winding outer diameter of the prepregs 42, 44, 46, 48 decreases stepwise from the prepreg 48 located on the outer end 12A side of the barrel member 12 to the prepreg 42 located on the inner end 12B side.

[0078] 6, the barrel member 12 is made from an assembly 40 of prepregs 42, 44, 46, and 48 made of a plurality of strips that differ from one another in axial length, thickness, winding outer diameter, and winding inner diameter, in other words, a plurality of prepreg strips that are arranged so that adjacent strips overlap each other in the radial direction at a portion in the axial direction, as a raw material. In the barrel member 12, the prepregs 42, 44, 46, and 48 of the assembly 40 are cured, and then the through holes 14 are formed by cutting.

[0079] As shown in Fig. 5(A), the prepregs 42, 44, 46, and 48 are made by impregnating a matrix (base material) 50 such as epoxy resin with fibers 52. Examples of the fibers 52 include glass fibers, carbon fibers, boron fibers, aramid fibers, and basalt fibers.

[0080] The fibers 52 are in a mesh or sheet form and are present in the matrix 50 in a cylindrical form wound in multiple layers around the central axis of the through-hole 14. As a result, the fibers 52 form a reinforcing member that includes a portion that extends continuously in the circumferential direction of the barrel member 12 formed by the matrix 50.

[0081] 5(B), the fibers 52 may be formed by winding a bundle of fibers 52 in a spiral shape with varying diameters multiple times around the central axis of the through-hole 14. In this case as well, the fibers 52 form a reinforcing member that extends continuously in the circumferential direction of the barrel member 12.

[0082] In the fourth embodiment, as in the first embodiment, a load that causes radial expansion and deformation of the barrel member 12 acts on the barrel member 12 due to the wedge action caused by driving the wedge member 20. Under this condition, the fibers 52 act as a reinforcing member to suppress radial expansion and deformation of the barrel member 12.

[0083] As a result, even if the barrel member 12 is made of matrix resin instead of steel for rust prevention, the barrel member 12 has sufficient strength to resist deformation due to enlargement of the diameter caused by the wedge action, and loosening of the wedge action is suppressed.

[0084] Thus, according to the fixing device 10 of embodiment 4, even when used for a long period of time, the barrel member 12 does not corrode, and the barrel member 12 has sufficient strength to withstand the tendency for the barrel member 12 to expand and deform due to wedging action, thereby preventing a decrease in the fixing strength of the cable 106 due to the expansion and deformation of the barrel member 12.

[0085] In the fourth embodiment, the barrel member 12 including the reinforcing member is efficiently manufactured using prepregs 42, 44, 46, and 48, resulting in good productivity. The prepregs 42, 44, 46, and 48 are composed of a plurality of strips arranged so as to overlap one another in the radial direction in a portion of the axial direction of the through hole 14, so that the barrel member 12 having the predetermined shape can be reliably formed using the prepregs 42, 44, 46, and 48.

[0086] Furthermore, according to the fixing device 10 of embodiment 4, the barrel member 12 has a shape that tapers gradually in the same direction as the through hole 14 due to the outer surfaces 42A, 44A, 46A, and 48A of each prepreg 42, 44, 46, and 48, so that the change in thickness at each part of the barrel member 12 in the axial direction is smaller than that of embodiment 1.

[0087] This allows the barrel member 12 to be manufactured efficiently using the prepregs 42, 44, 46, and 48, improving productivity and making the wall thickness of the barrel member 12 more uniform over the entire axial length. Furthermore, the wall thickness of the barrel member 12 can be made closer to the minimum required thickness over the entire axial length, making the barrel member 12 more compact and lightweight.

[0088] Furthermore, after hardening, the end faces 42B, 44B, 46B, 48B on the inner end 12B side of the prepregs 42, 44, 46, 48 increase the adhesion strength between the barrel member 12 and the concrete block 102 when embedded in the concrete block 102, and act as barrier surfaces that prevent the barrel member 12 from moving axially (to the right) relative to the concrete block 102.

[0089] This effectively prevents the barrel member 12 from moving in the axial direction (to the right) relative to the concrete block 102. As a result, high-quality prestressed concrete 100 that has been given stable prestress over a long period of time can be produced with high productivity without requiring additional parts or processes. (Embodiment 5) The fixing device 10 of the fifth embodiment will be described with reference to Figures 7 and 8. In Figures 7 and 8, parts corresponding to those in Figure 2 are given the same reference numerals as those in Figure 2, and descriptions thereof will be omitted.

[0090] The barrel member 12 is a cylindrical molded product made of a fiber-reinforced resin containing a matrix resin such as an epoxy resin or a polyester resin and fibers such as glass fiber, carbon fiber, boron fiber, aramid fiber, or basalt fiber, and is molded into a cylindrical shape including a through hole 14. The barrel member 12 may be a product equivalent to the barrel member 12 of the first embodiment.

[0091] A spiral groove 12D with a semicircular cross section is formed at a predetermined pitch on the outer peripheral surface 12C of the barrel member 12 over substantially the entire length in the axial direction of the barrel member 12. A spiral restraint body 60 with a circular cross section is fitted into the spiral groove 12D. The spiral restraint body 60 is a molded product made of a fiber-reinforced resin that combines a matrix resin such as epoxy resin or polyester resin with fibers such as glass fiber, carbon fiber, boron fiber, aramid fiber, basalt fiber, or steel fiber.

[0092] As a result, the spiral restraint body 60 is wound around the outer peripheral surface 12C of the barrel member 12 and forms a reinforcing member that includes a portion extending in the circumferential direction of the barrel member 12. Because the spiral restraint body 60 is fitted into the spiral groove 12D, the spiral restraint body 60 does not shift relative to the barrel member 12 during, for example, the production of the concrete block 102, and the position of the spiral restraint body 60 relative to the barrel member 12 does not change. This stabilizes the effect of the spiral restraint body 60 in suppressing radial expansion and deformation of the barrel member 12.

[0093] The helical restraint body 60 can be fitted into the helical groove 12D by expanding the helical restraint body 60 so that its inner diameter becomes larger than the outer diameter of the barrel member 12, and then moving the helical restraint body 60 axially relative to the barrel member 12 from one end side of the barrel member 12, and releasing the expansion deformation at a position where the helical restraint body 60 is axially aligned with the helical groove 12D, or by rotating the helical restraint body 60 relative to the barrel member 12 and screwing it into the helical restraint body 60 from one end side of the barrel member 12.

[0094] In the fifth embodiment, as in the first embodiment, a load that causes radial expansion and deformation of the barrel member 12 is applied to the barrel member 12 due to the wedge action caused by the driving of the wedge member 20. Under this condition, the spiral constraint body 60 acts as a reinforcing member to suppress radial expansion and deformation of the barrel member 12. To ensure this effect, the spiral constraint body 60 is preferably fitted into the spiral groove 12D in a preloaded state.

[0095] As a result, even if the barrel member 12 is made of matrix resin instead of steel for rust prevention, the barrel member 12 has sufficient strength to resist deformation due to enlargement of the diameter caused by the wedge action, and loosening of the wedge action is suppressed.

[0096] Thus, according to the fixing device 10 of embodiment 5, the spiral restraint body 60 effectively suppresses radial expansion and deformation of the barrel member 12. As a result, even with long-term use, the barrel member 12 does not corrode, the barrel member 12 has sufficient strength to resist radial expansion and deformation due to wedging action, and a decrease in the fixing strength of the cable 106 caused by radial expansion and deformation of the barrel member 12 is effectively suppressed.

[0097] The spiral restraint body 60 may be made of a high-tensile fiber-reinforced resin having a higher Young's modulus and tensile strength than the barrel member 12. In other words, the spiral restraint body 60 is made of a fiber-reinforced resin having a higher Young's modulus than the fiber-reinforced resin that makes up the barrel member 12.

[0098] In this case, the barrel member 12 is made of a glass fiber reinforced resin, which is cheaper than carbon fiber, etc., and the reinforcing action of the spiral restraint body 60 provides strength (strength that suppresses radial expansion deformation of the barrel member 12) similar to that of a barrel member 12 made of a carbon fiber reinforced resin, etc. This effectively suppresses radial expansion deformation of the barrel member 12 and reduces the material cost of the barrel member 12.

[0099] (Embodiment 6) A fixing tool 10 of the sixth embodiment will be described with reference to Fig. 9. In Fig. 9, parts corresponding to those in Fig. 2 are given the same reference numerals as those in Fig. 2, and descriptions thereof will be omitted.

[0100] The barrel member 12 is a molded product made of a fiber-reinforced resin containing a matrix resin such as epoxy resin or polyester resin and fibers such as glass fiber, carbon fiber, boron fiber, aramid fiber, or basalt fiber, and is molded into a truncated cone shape including a through hole 14. The outer peripheral surface 12E of the barrel member 12 is a conical surface (tapered surface) whose outer diameter gradually decreases from the outer end 12A toward the inner end 12B. In other words, the barrel member 12 has a conical shape that tapers in the same direction as the through hole 14.

[0101] A plurality of annular restraint bodies 70 are attached at intervals in the axial direction to the outer peripheral surface 12E of the barrel member 12. Each annular restraint body 70 is a molded product made of a fiber-reinforced resin that combines a matrix resin such as epoxy resin or polyester resin with fibers such as glass fiber, carbon fiber, boron fiber, aramid fiber, basalt fiber, or steel fiber.

[0102] Each annular restraint 70 has a tapered inner peripheral surface 70A that matches the outer peripheral surface 12E of the barrel member 12, and the inner peripheral surface 70A is fitted to the outer peripheral surface 12E of the barrel member 12 so that it cannot be displaced in the axial direction of the barrel member 12.

[0103] Each annular restraining body 70 has an end surface 70B on the tapered side of the conical shape of the barrel member 12 (the right side in the drawing) that is perpendicular to the axial direction of the barrel member 12.

[0104] In the fifth embodiment, as in the first embodiment, a load that causes radial expansion and deformation of the barrel member 12 acts on the barrel member 12 due to the wedge action caused by driving the wedge members 20. Under this condition, each annular restraining body 70 acts as a reinforcing member to suppress the radial expansion and deformation of the barrel member 12.

[0105] As a result, even if the barrel member 12 is made of matrix resin instead of steel for rust prevention, the barrel member 12 has sufficient strength to resist deformation due to enlargement of the diameter caused by the wedge action, and loosening of the wedge action is suppressed.

[0106] Thus, according to the fixing device 10 of embodiment 5, the annular restraint 70 effectively suppresses radial expansion and deformation of the barrel member 12. As a result, the barrel member 12 does not corrode even after long-term use, the barrel member 12 has sufficient strength to resist radial expansion and deformation due to wedging action, and a decrease in the fixing strength of the cable 106 caused by radial expansion and deformation of the barrel member 12 is effectively suppressed.

[0107] Each annular restraint body 70 may be made of a high-tensile fiber-reinforced resin having a higher Young's modulus and tensile strength than the barrel member 12. In other words, each annular restraint body 70 is made of a fiber-reinforced resin having a higher Young's modulus than the fiber-reinforced resin that makes up the barrel member 12.

[0108] In this case, the barrel member 12 is made of a glass fiber reinforced resin, which is cheaper than carbon fiber, etc., and the reinforcing action of each annular restraining body 70 provides strength (strength that suppresses radial expansion deformation of the barrel member 12) similar to that of a barrel member 12 made of a carbon fiber reinforced resin, etc. This effectively suppresses radial expansion deformation of the barrel member 12 and reduces the material cost of the barrel member 12.

[0109] Because the barrel member 12 has a conical shape tapering in the same direction as the through hole 14, the barrel member 12 is prevented from moving axially (to the right) relative to the concrete block 102, resulting in a high-quality concrete block 102 that is stably prestressed over a long period of time.

[0110] In addition, when embedded in the concrete block 102, each annular restraint 70 increases the adhesion strength between the barrel member 12 and the concrete block 102, and the end surface 70B of each annular restraint 70 serves as a barrier surface that prevents the barrel member 12 from moving axially (to the right) relative to the concrete block 102.

[0111] This action effectively prevents the barrel member 12 from moving in the axial direction relative to the concrete block 102. As a result, high-quality prestressed concrete 100 that has been given stable prestress over a long period of time can be produced with high productivity without requiring additional parts or processes.

[0112] (Embodiment 7) A seventh embodiment of the prestressed concrete 100 will be described with reference to Fig. 10. In Fig. 10, parts corresponding to those in Fig. 2 are designated by the same reference numerals as those in Fig. 2, and description thereof will be omitted.

[0113] In this embodiment, the anchors 10 are attached to both ends of a concrete block 102 after it has been molded and hardened.

[0114] More specifically, outwardly opening truncated cone-shaped recesses 112 are formed in both longitudinal ends of the concrete block 102. Each recess 112 has an axial length greater than that of the fastener 10. A bottom surface 112A of each recess 112 forms a part of the substantial outer end surface of the concrete block 102.

[0115] The fixing device 10 is attached to the concrete block 102 so that the inner end 12B of the barrel member 12 abuts against the bottom surface 112A of the recess 112 via the backing plate 80, and the outer circumferential surface 12C of the barrel member 12 is exposed outward. In this embodiment, the entire barrel member 12 is disposed within the recess 112.

[0116] The fixing device 10 applies tension to the cable 106, and this tension presses the inner end 12B of the barrel member 12 against the backing plate 80, thereby fixing the fixing device 10 to the concrete block 102.

[0117] The prestressed concrete 100 of this embodiment is easy to maintain, such as by replacing the fasteners 10.

[0118] The recess 112 may be filled with mortar, asphalt, resin, or the like after the fixing tool 10 is placed.

[0119] The fixing device 10 applied to the other embodiment shown in FIG. 10 is not limited to the fixing device 10 of the first embodiment, but may be the fixing device 10 of the second to sixth embodiments.

[0120] The present invention has been described above in terms of its preferred embodiments, but as can be easily understood by those skilled in the art, the present invention is not limited to such embodiments and can be modified as appropriate within the scope of the invention.

[0121] For example, the barrel member 12 and the wedge member 20 may be made of a material that is resistant to oxidation and corrosion, such as mortar, in addition to resin. The barrel member 12 in embodiments 2, 3, 5, and 6 may be made of a resin that does not contain fibers. The wedge member 20, the spiral constraint body 60, and the annular constraint body 70 may be made of a material that is resistant to oxidation and corrosion, such as titanium, in addition to resin. The number of wedge members 20 is not limited to two and may be three or more. The wire material may be a flexible rod instead of the cable 106. The fixing device 10 is not limited to being entirely embedded in the concrete block 102; only the inner end 12B of the barrel member 12 may be embedded in the concrete block 102 over a predetermined axial length.

[0122] Furthermore, not all of the components shown in the above embodiments are necessarily essential, and they can be selected as appropriate without departing from the spirit of the present invention. [Explanation of symbols]

[0123] 10: Fixing device 12: Barrel member 12A: Outer end 12B: Inner end 12C: Outer surface 12D: Spiral groove 12E: Outer surface 14:Through hole 14A: Inner surface 16: Fiber 20: Wedge member 20A: Outer surface 20B: Cable groove 20C:Half-cut surface 30: cyclic body 30A: End face 40: Union 42: Prepreg 42A: Outer surface 42B: End face 44: Prepreg 44A: Outer surface 44B: End face 46: Prepreg 46A: Outer surface 46B: End face 48: Prepreg 48A: Outer surface 48B: End face 50: Matrix 52: Fiber 60: Spiral restraint body 70: Ring-shaped constraint 70A: Inner surface 70B: End face 80: Backing plate 100: Prestressed concrete 102: Concrete block 104: Sheath 106: Cable 108: Grout 110: Fixture burying hole 110A: End face 110B: Inner surface 112: Recess 112A: Bottom

Claims

1. A fixing device for an end of a wire, a barrel member made of resin or mortar and having a tapered through-hole; a plurality of wedge members each having a tapered outer peripheral surface that is in sliding contact with the inner peripheral surface of the through hole and that cooperate with each other to hold the wire; a reinforcing member including a portion extending in a circumferential direction of the barrel member; the barrel member is made of prepreg wound into a cylindrical shape so as to have an outer circumferential surface that tapers stepwise in the same direction as the tapered shape of the through hole, The prepreg includes a resin base material and fibers impregnated in the base material, The reinforcing member is a fixing tool made of the fibers contained in the prepreg.

2. The fixing device according to claim 1 , wherein the prepreg is formed of a plurality of strips arranged so as to overlap each other in the radial direction in a portion of the axial direction of the through hole.

3. A fixing device as described in claim 1 or 2, wherein the reinforcing member includes an annular body provided on the outer periphery of the barrel member to surround the barrel member.

4. A fixing device for an end of a wire, a barrel member made of resin or mortar and having a tapered through-hole; a plurality of wedge members each having a tapered outer peripheral surface that is in sliding contact with the inner peripheral surface of the through hole and that cooperate with each other to hold the wire; a reinforcing member including a portion extending in a circumferential direction of the barrel member; the reinforcing member includes an annular body provided on an outer periphery of the barrel member so as to surround the barrel member, The barrel member is made of fiber reinforced resin, The annular body is a fixing tool made of a fiber reinforced resin having a higher Young's modulus than the fiber reinforced resin that makes up the barrel member.

5. A fixing device for an end of a wire, a barrel member made of resin or mortar and having a tapered through-hole; a plurality of wedge members each having a tapered outer peripheral surface that is in sliding contact with the inner peripheral surface of the through hole and that cooperate with each other to hold the wire; a reinforcing member including a portion extending in a circumferential direction of the barrel member; the reinforcing member includes an annular body provided on an outer periphery of the barrel member so as to surround the barrel member, The annular body is a fixing tool that is partially provided in the axial direction of the through hole.

6. A fixing device for an end of a wire, a barrel member made of resin or mortar and having a tapered through-hole; a plurality of wedge members each having a tapered outer peripheral surface that is in sliding contact with the inner peripheral surface of the through hole and that cooperate with each other to hold the wire; a reinforcing member including a portion extending in a circumferential direction of the barrel member; The barrel member has a cylindrical outer circumferential surface, the reinforcing member includes a spiral constraint wound around the outer circumferential surface of the barrel member, The barrel member is made of fiber reinforced resin, The spiral constraint body is a fixing tool made of a fiber reinforced resin having a higher Young's modulus than the fiber reinforced resin that makes up the barrel member.

7. The barrel member has a spiral groove on its outer circumferential surface, 7. The fixture of claim 6, wherein the helical restraint is fitted into the helical groove.

8. A fixing device for an end of a wire, a barrel member made of resin or mortar and having a tapered through-hole; a plurality of wedge members each having a tapered outer peripheral surface that is in sliding contact with the inner peripheral surface of the through hole and that cooperate with each other to hold the wire; a reinforcing member including a portion extending in a circumferential direction of the barrel member; the barrel member has an outer circumferential surface of a conical shape tapered in the same direction as the through hole, The reinforcing member is a fixture including an annular restraining body fitted to the outer peripheral surface of the barrel member.

9. The fixing device according to claim 8 , wherein the annular restraining body includes a surface at the end surface on the tapered side of the conical shape of the barrel member that is perpendicular to the axial direction of the barrel member.

10. A fixing device as described in claim 8 or 9, wherein the annular restraint is partially provided in the axial direction of the barrel member.

11. The barrel member is made of fiber-reinforced resin, The fixing tool according to any one of claims 8 to 10, wherein the annular restraining body is made of a fiber reinforced resin having a higher Young's modulus than the fiber reinforced resin that constitutes the barrel member.

12. 12. The fixing device according to claim 1, wherein each wedge member is made of resin or fiber-reinforced resin.

13. A rectangular parallelepiped concrete block through which the wire passes in the longitudinal direction; 13. Prestressed concrete comprising: an anchoring device according to claim 1, which is provided at both longitudinal ends of the concrete block and anchors the ends of the wire rods.

14. 14. The prestressed concrete of claim 13, wherein the anchors are embedded in the concrete blocks.

15. 14. The prestressed concrete according to claim 13, wherein the fixing device is attached to the concrete block so that one end face of the barrel member abuts against the end face of the concrete block and the outer circumferential surface of the barrel member is exposed outward.

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