JP2013234531A - Anchorage structure for outer cable - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an anchorage structure for an outer cable capable of being re-tensioned.SOLUTION: An anchorage structure α for an outer cable imparts a tensioning force of each prestressing steel wire 1 to a concrete structure 100 via an outer cable anchorage part 101 to reinforce the concrete structure 100. The outer cable anchorage part 101 is a concrete member to which the prestressing steel wire 1 is to be anchored by an anchorage device 2. The anchorage structure α for the outer cable also includes an anchor disc 4, and a rust-proof body 9 which covers an end of the prestressing steel wire 1 and a wedge 3 exposed from the anchor disc 4 and which is interposed between the outer cable anchorage part 101 and the prestressing steel wire 1. The rust-proof body contains a post-curable brittle resin.

Description

  The present invention relates to a fixing structure for an outer cable that reinforces a concrete structure by applying tension forces of a plurality of strained PC steel wires to the concrete structure. In particular, the present invention relates to an outer cable fixing structure capable of re-tensioning a PC steel wire once fixed.

  As a concrete structure, a PC structure in which compressive force is introduced in advance using an internal cable (eg, PC steel wire) that is a tension material and a fixing tool, an RC or SC, an SRC structure in which reinforcing bars or steel frames are arranged, etc. There is. Conventionally, such concrete structures are used for roads, railway bridges, buildings, and the like.

  In Japan, the above-mentioned concrete structures have been built in large quantities from the postwar period to the period of high economic growth (especially from the mid 1950s to the early 70s). As a result, in the 2000s, many concrete structures had their useful lives. I'm going to greet you. As a countermeasure against such an existing structure that has passed for a long time since construction, it is desired to repair and reinforce the existing structure. This is because it is not easy to rebuild traffic infrastructure such as roads and bridges.

  In recent years, therefore, it has been proposed to use an external cable construction method in which an external cable (eg, a PC steel wire) is disposed outside the existing structure as a repair / reinforcement measure for the existing structure (especially a PC structure). Yes. For example, Patent Document 1 discloses a technique for prestressing a bridge by fixing an external cable to an external cable fixing portion provided in a bridge girder of a bridge and applying tension of the external cable to the bridge girder. ing. Japanese Patent Application Laid-Open No. H10-228667 discloses a technique for providing an external cable with a system for monitoring a decrease in the strength of a bridge so as to grasp the necessity of repair / reinforcement of the bridge.

JP 2011-122905 A

  However, even if it is possible to determine whether or not the concrete structure needs to be repaired or reinforced by the technique of Patent Document 1, there is a problem that the actual repair / reinforcing work is complicated.

  In the conventional outer cable method, the outer cable is fixed to the outer cable fixing portion with cement grout or the like. In other words, once an external cable has been installed, it cannot be re-tensioned. Therefore, if it is determined that the existing structure needs repair or reinforcement, it is necessary to take measures such as adding a new external cable. There is.

  The present invention has been made in view of the above circumstances, and one of its purposes is to provide an outer cable fixing structure capable of re-tensioning a PC steel wire as required.

  The fixing structure of the external cable according to the present invention includes a plurality of PC steel wires, a fixing tool, and an external cable fixing portion, and applies tension force of each PC steel wire to the concrete structure via the external cable fixing portion. By doing so, it is a fixing structure of the outer cable that reinforces the concrete structure. The fixing device includes an anchor disk having a plurality of wedges that individually hold the tensioned PC steel wire and a plurality of wedge holes into which the wedges are fitted. The outer cable fixing portion is a concrete member to which the PC steel wire is fixed by a fixing tool. The fixing structure of the outer cable of the present invention having this configuration further covers the anchor disk, the wedge exposed from the anchor disk, and the end of the PC steel wire, and is interposed between the outer cable fixing portion and the PC steel wire. The rust preventive body includes a post-curing brittle resin.

  The post-curing brittle resin in the fixing structure of the external cable of the present invention is a resin that becomes a low-viscosity liquid before curing and becomes a jelly-like solid after curing. This brittle resin has such a strength that it can stand on its own and does not naturally collapse, but has such a strength that it can be broken into pieces by human power. When the brittleness of the brittle resin is expressed by a physical quantity, for example, tensile strength can be given. For example, the tensile strength of the brittle resin is 70 to 200 kPa.

  If it is the fixing structure body of an external cable provided with the said structure, a PC steel wire can be re-tensioned. This is because the rust preventive body responsible for rust is made of a brittle resin, so that the rust preventive body easily collapses during the re-tensioning of the PC steel wire and does not hinder the re-tension of the PC steel wire. Here, although the rust preventive body collapsed by the re-tensioning of the PC steel wire becomes fragments of various sizes, these fragments do not hinder the re-fixation of the PC steel wire. This is because even if the fragments enter between member gaps such as between the wedges or between the wedge and the anchor disk, the fragments made of the brittle resin are compressed between the members and further finely disintegrated to be expelled from the member gap.

  Moreover, the brittle resin rust preventive body exhibits a rust preventive effect over a long period of time in the outer cable fixing structure. This is because the brittle resin is solid even if it is brittle, and therefore it remains semipermanently in the portion to be rust-prevented. On the other hand, when the formation part of the rust preventive body in the present invention is replaced with rust preventive oil or grease, it is difficult to maintain the rust preventive effect for a long time. This is because not only low-viscosity rust preventive oils but also greases of slightly higher viscosity than these may be leaked from the fixing structure because they are fluids.

  Furthermore, by using a rust preventive body made of a brittle resin, it is possible to facilitate re-tensioning of the PC steel wire. The brittle resin does not have the problem of dripping liquid such as rust preventive oil or grease when the PC steel wire is re-tensioned, and there is no problem that the surface of the re-tensioned PC steel wire becomes sticky and difficult to handle. It is.

  As one form of the fixing structure of the outer cable of the present invention, the outer cable fixing portion can be a form retrofitted to the side surface of the concrete structure.

  According to the said structure, the existing concrete structure can be reinforced and repaired. The outer cable fixing portion in the fixing structure of the outer cable of the present invention may be a portion that originally protrudes to the side of the concrete structure. That is, this is a configuration in which the fixing structure of the external cable of the present invention is applied to the external cable that reinforces the newly-installed concrete structure.

  As one form of the fixing structure of the outer cable of the present invention, there may be mentioned a form provided with a disk receiver that is embedded in the outer cable fixing section and disperses the pressure of the anchor disk and transmits it to the outer cable fixing section. This disk receiver is provided through the outer cable fixing part, and a cylindrical part through which the PC steel wire is inserted, and an anchor plate part that is provided on one end side of the cylindrical part and is in contact with the anchor disk And a water stop part provided on the other end side of the cylindrical part and partitioning the internal space of the cylindrical part from the external space. In this case, the rust preventive body covers the outer periphery of the PC steel wire inside the cylindrical portion.

  According to the configuration including the disk receiver, it is possible to prevent damage to the outer cable fixing unit by dispersing the pressure of the anchor disk and transmitting it to the outer cable fixing unit. In order to disperse the pressure, the area of the pressing surface of the anchor plate portion may be made larger than the pressing surface of the anchor disk. Further, according to the disk receiver, the PC steel wire in the outer cable fixing portion can be re-tensioned, and the PC steel wire can be partitioned from the external environment inside the cylindrical portion. The wire is hard to rust.

  As one form of the fixing structure of the external cable of the present invention, the anchor cable and the rust prevention cap that covers the PC steel wire protruding from the anchor disk from the outer peripheral side are provided on the side where the anchor disk is arranged in the external cable fixing part. The form can be mentioned. In this case, the rust preventive cap is filled with the rust preventive body.

  Rust prevention of each member can be made more reliable by covering from the anchor disk to the tip of the PC steel wire with a rust prevention cap filled with a rust prevention body.

  As one form of the fixing structure of the external cable of the present invention provided with a rust prevention cap, a form including a first inlet of a brittle resin at a position exposed from the external cable fixing part in the water stopping part of the disk receiver is given. Can do.

  According to the said structure, the brittle resin inject | poured from the 1st injection hole can be finally discharged in a rust prevention cap through the cylindrical part of a disk receptacle. Therefore, it is possible to easily form a rust preventive body that bears rust prevention on the wedge and the portion gripped by the wedge of the PC steel wire. Of course, the first inlet can also be used to refill the brittle resin into the gaps of the rust preventive body that collapsed when the PC steel wire is re-tensioned.

  As one form of the fixing structure of the outside cable of the present invention provided with a rust prevention cap, a form provided with a second injection port of a brittle resin at a position near the anchor disk in the rust prevention cap can be mentioned.

  According to the above configuration, the brittle resin injected from the second injection port can be filled in the rust prevention cap and also discharged to the cylindrical portion of the disk receiver. Therefore, the rust preventive body in the present invention can be easily formed. Of course, the second inlet can also be used for refilling the brittle resin.

  Here, both the second inlet and the above-described first inlet may be provided, or only one of them may be provided. Further, the brittle resin discharge port is preferably provided in the rust prevention cap regardless of which injection port is used (including the case where both are provided).

  As one form of the fixing structure of the cable outside the present invention provided with a rust prevention cap, a tubular body is provided with a tubular body that individually accommodates each PC steel wire, and the internal space of the tubular body is connected to the outer peripheral surface of the tubular body. The form divided from the space between the inner peripheral surfaces of a cylindrical part can be mentioned. In this case, the inner space of the tubular body is filled with a rust preventive body.

  By providing the tubular body, the PC steel wire can be protected by the double barrier of the tubular body and the cylindrical portion, and the PC steel wire can be hardly rusted. Further, in the configuration in which the brittle resin before curing is filled from the inlet, the filling amount of the brittle resin can be saved. This is because when the brittle resin is filled from the injection port, the brittle resin flows not into the entire inside of the cylindrical portion but into the tube disposed inside the cylindrical portion.

  According to the fixing structure of the external cable of the present invention, the PC steel wire can be re-tensioned as necessary.

It is a schematic diagram which shows the installation state of the fixing structure of the bridge which is a reinforcement object described in embodiment, and the cable outside this invention with respect to the bridge. It is a schematic longitudinal cross-sectional view of the fixing structure of the outer cable which concerns on embodiment. (A) is a front view of a disk receiver, (B) is a BB sectional view of (A). (A) is a front view of an anchor disk, (B) is a BB sectional view of (A). (A) is a front view of a rust prevention cap, (B) is BB sectional drawing of (A). (A) is a front view of a spacer, (B) is BB sectional drawing of (A). (A) is a front view of a pressing member, (B) is a BB sectional view of (A).

  Embodiments of the present invention will be described with reference to the drawings. In the drawings, the same members are denoted by the same reference numerals.

<Concrete structure>
In this embodiment, an example in which a fixing structure for a cable outside the present invention is applied to a railway bridge that is a concrete structure will be described. The bridge (concrete structure) 100 of the present embodiment shown in FIG. 1 is an existing one and has been repaired later by the outer cable 1. The fixing structure α of the outer cable of the present invention is applied to fixing the outer cable 1. In addition, in FIG. 1, although the external cable 1 is shown by the single number, actually there exist multiple.

  The outer cable 1 is arranged so as to be suspended over the outer cable fixing portion 101 protruding from the side surface of the bridge 100. Both the outer cable fixing portions 101 and 101 are attached to the side surface of the bridge 100 later, and the outer cable 1 is exposed to the side of the bridge 100 between the outer cable fixing portions 101 and 101. Further, both end portions of the outer cable 1 are fixed by fixing tools 2 and 2 in the outer cable fixing portions 101 and 101, respectively, and intermediate portions of the outer cable 1 are deviators 110 and 110 provided below the bridge 100. , 110 are inserted and held. The deviator 110 deflects the outer cable 1. By using the deviator 110, it is possible to apply a bending force (a force to bend the intermediate portion so as to be convex upward) to the bridge 100 and improve the bending strength of the bridge 100.

<Fixing structure for external cable>
Next, a fixing structure α of the outer cable formed by fixing the PC steel wire 1 (outer cable) with the fixing tool 2 will be described with reference to FIG. 2, the fixing structure α on the left side of FIG. 1 will be described. The fixing structure α on the right side of FIG. 1 has a line-symmetric structure with the fixing structure α on the left side of the paper, and thus the description thereof is omitted.

  The fixing structure α of the outer cable includes a plurality of strained PC steel wires 1 and a fixing tool 2 that fixes the PC steel wires 1 in a tensioned state. The fixing tool 2 includes a wedge 3 for individually holding each PC steel wire 1 and an anchor disk 4 having a wedge hole 40H into which the wedge 3 in a state of holding the PC steel wire 1 is fitted. By fixing each PC steel wire 1 in a tensioned state to the outer cable fixing portion 101 by the fixing tool 2, the tension force of each PC steel wire 1 is transferred to the outer cable fixing portion 101 (that is, the outer cable fixing portion 101) via the anchor disk 4. It can be applied to the bridge 100) to which the cable fixing unit 101 is attached.

  The most characteristic feature of the fixing structure α of the outer cable in the present embodiment is the periphery of the anchor disk 4, in particular, the anchor disk 4, the wedge 3 exposed from the anchor disk 4, and the end of the PC steel wire 1. Is provided with a rust prevention body 9 interposed between the outer cable fixing portion 101 and the PC steel wire 1, and the rust prevention body 9 is made of a post-curing brittle resin. The rust preventive body 9 around the anchor disk 4 is surely provided on the front surface side (the exposed end surface side of the wedge 3 on the left side in FIG. 2) and the back surface side (between the anchor plate portion 50 on the right side in FIG. 2). It is preferable to cover with. In addition, the rust prevention body 9 in this embodiment is also formed in places other than the part mentioned above. A specific location where the rust preventive body 9 is formed and a configuration other than the fixing tool 2 provided in the fixing structure α will be described when the formation procedure of the fixing structure α is described.

The post-curing brittle resin constituting the rust preventive body 9 is a resin that is in a low-viscosity liquid before curing and becomes a jelly-like solid after curing. More specifically, the definition of the brittle resin is a resin that has a strength that can stand by itself and does not spontaneously collapse, but has a strength that can be broken into pieces by human power. For example, a tensile strength of 70 to It is a resin of about 200 kPa. Specific examples of the brittle resin include “Removable Resin 4441J” manufactured by Sumitomo 3M Limited. This “decomposable resin” is obtained by mixing the following solution A and solution B, and curing the mixture over time. The “decomposable type resin” (mixed liquid) before curing is a liquid having a viscosity of about 600 to 700 kPa / s (25 ° C.), and the “decomposable type resin” after curing has a tensile strength of about 75 kPa. It is a brittle resin.
Solution A: vegetable oil, polybutadiene polymer, epoxidized fatty acid glyceroid Solution B: mineral oil, polybutadiene, N, N, N-tri-alkylamine

<Effect of fixing structure of outer cable>
According to the fixing structure α of the outer cable having the above configuration, a plurality of PC steel wires 1 that have been fixed once can be re-tensioned. Since the rust preventive body 9 responsible for rust prevention of the wedge 3 and the PC steel wire 1 is made of a brittle resin, the rust preventive body 9 easily collapses when the PC steel wire 1 is re-tensioned, and the PC steel wire 1 is re-tensed. It is because it does not inhibit.

  Further, by performing rust prevention treatment using a brittle resin that is brittle but solid, the problem of liquid leakage such as rust prevention treatment using a fluid such as rust prevention oil or grease can be eliminated. In addition, in the rust prevention treatment using a brittle resin, it is easy to handle the PC steel wire 1 when the PC steel wire 1 is re-tensioned and re-fixed. This is because there is no problem that the surface of the PC steel wire 1 becomes sticky like rust preventive oil or grease.

  Further, in the fixing structure α of the outer cable having the above-described configuration, each PC steel wire 1 is individually gripped by the wedge 3, so that each PC steel wire 1 can be individually re-tensioned. Therefore, fine adjustment of the tension applied to the outer cable fixing unit 101 can be easily performed, and damage to the outer cable fixing unit 101 due to excessive tension acting on the outer cable fixing unit 101 can be avoided. Furthermore, since each PC steel wire 1 can be individually tensioned, a small jack can be used when the PC steel wire 1 is tensioned and re-tensioned. In particular, when the fixing structure α is added to the existing bridge 100 later, a large work space cannot be secured in many cases. Therefore, the use of a small jack is a great merit in terms of work.

<Procedure of fixing structure of outer cable>
The procedure for producing the fixing structure α shown in FIG. 2 is as follows.
[1] The outer cable fixing portion 101 in which the disk receiver 5 is embedded is attached to the side surface of the bridge 100 as the outer cable fixing portion 101 of the bridge 100 in FIG.
[2] A plurality of PC steel wires 1 are inserted into the disk receiver 5.
[3] Tension each PC steel wire 1 and fix it.
[4] A rust prevention cap 6 is attached to the tip of the PC steel wire 1.
[5] A post-curing brittle resin is filled in the fixing device 2 to cure the brittle resin.

[1] Arrangement of Outer Cable Fixing Unit The outer cable fixing unit 101 in which the disk receiver 5 is embedded is manufactured by, for example, disposing the disk receiver 5 in a mold, pouring concrete into the mold, and hardening it. Can do. The outer cable fixing unit 101 is attached to the side surface of the bridge 100 with a bolt (not shown).

  The disk receiver 5 embedded in the outer cable fixing unit 101 is a member that disperses the pressure of the anchor disk 4 and transmits it to the outer cable fixing unit 101, and prevents damage to the outer cable fixing unit 101 due to the pressure. It is. Further, the outer cable fixing portion 101 and the PC steel wire 1 are fixed to each other so that the PC steel wire 1 can be re-tensioned in a space for preventing the PC steel wire 1 inside the outer cable fixing portion 101 from being rusted. It is also a member that forms a space for this purpose. The disk receiver 5 can be formed of, for example, SS400 or the like, and the entire surface thereof is rust-proofed by hot dip galvanization.

  The disc receiver 5 is formed on a cylindrical portion 51 into which the PC steel wire 1 is inserted, an anchor plate portion 50 formed on one end side of the cylindrical portion 51, and the other end side of the cylindrical portion 51. A water stop portion 53 (see also FIG. 3).

  The anchor plate portion 50 includes a recess 50C (see FIG. 3) for fitting the anchor disk 4 on one surface side thereof, and receives the pressure of the anchor disk 4. The other surface side of the anchor plate portion 50 is provided in contact with the outer cable fixing portion 101. That is, the anchor plate unit 50 distributes the pressure of the anchor disk 4 and transmits the pressure to the outer cable fixing unit 101, thereby suppressing the damage to the outer cable fixing unit 101 and appropriately applying the pressure to the outer cable fixing unit 101. It has a role to convey to. In order to disperse the pressure of the anchor disk 4, as shown in FIG. 3A, the area when the anchor plate portion 50 is viewed in plan is approximately equal to the area when the anchor disk is viewed in plan (the area of the recess 50C). Greater than).

  As shown in FIG. 3 (A), jack mounting holes JH for tensioning the PC steel wire are formed at the four corners of the anchor plate portion 50. In addition, a plurality of screw holes 50H arranged concentrically are formed on the inner peripheral side of the mounting holes JH. The screwing holes 50H are for fixing a rust prevention cap 6 described later.

  The cylindrical part 51 is a part embedded in the outer cable fixing part 101, and is a large-diameter cylindrical body into which the PC steel wire 1 can be inserted. In the present embodiment, a tubular body 54 through which the PC steel wire 1 is individually inserted is provided inside the cylindrical portion 51. The inner diameter of the tube body 54 is about 3 mm to 4 mm larger than the outer diameter of the PC steel wire 1, and when the PC steel wire 1 is inserted through the tube body 54, a gap is formed between them.

  One end side of the tube body 54 opens to the recess 50 </ b> C of the anchor plate portion 50, and the other end side of the tube body 54 opens to a partition portion 51 </ b> S provided on the other end side of the tubular portion 51. With such a configuration, the internal space of the cylindrical portion 51 surrounded by the inner peripheral surface of the cylindrical portion 51, the inner side surface of the anchor plate portion 50, and the inner side surface of the partition portion 51S is isolated from the outside. The Further, the internal space and the internal space of the tube body 54 are also isolated.

  The water stop portion 53 is a portion on the other end side (right side on the paper surface) of the disc receiver 5 with respect to the partition portion 51S. A partition portion 53S is provided on the other end side further than the partition portion 51S. The partition portion 53S includes an insertion hole 53SH at a position corresponding to the tubular body 54 of the partition portion 51S. The inner diameter of the insertion hole 53SH is larger than the inner diameter of the tube body 54 (about 8 mm to 10 mm larger than the outer diameter of the PC steel wire 1).

Between the partition portion 51S and the partition portion 53S of the water stopper 53, the first inlet 5 _IN for injecting brittle resin is opened. Further, a flange portion 53F is provided at the end of the partition portion 53, and a plurality of screw holes 53FH arranged at equal intervals are provided in the flange portion 53F.

[2] Arrangement of PC Steel Wire The PC steel wire 1 used in this embodiment includes a stranded wire 10 obtained by twisting a plurality of strands, and a coating 11 made of a resin such as epoxy formed on the outer periphery thereof. It is a coated PC steel wire provided. Of course, the PC steel wire 1 may be one in which a coating 11 is formed on the outer periphery of a single wire. In addition, the coating 11 of the PC steel wire 1 is not necessarily formed, if necessary.

  The PC steel wire 1 is inserted through the through hole 53SH of the partition portion 53S of the disc receiver 5 into the tube body 54 opened to the partition portion 51S, and pulled out from the anchor plate portion 50 of the disc receiver 5. As shown in FIG. 2, packing 71, spacer 72, leak-proof plate 73, pressing member packing 74, spacer 72, and so on are arranged in advance from the anchor disk 4 side on the outer periphery of the PC steel wire 1 in advance. The packing 71 and the pressing member 75 are fitted (the fitting order of the leakage prevention plate 73 and the pressing member packing 74 may be reversed). Here, the coating 11 at the end of the PC steel wire 1 to be disposed is stripped off. The stripping position of the covering 11 is on the outer cable fixing unit 101 side (right side on the paper surface) with respect to the anchor plate unit 50 and on the outer cable fixing unit 101 side (left side on the paper surface) with respect to the partition portion 51S of the disk receiver 5. For example, the covering 11 may be peeled off so that the peeled end of the covering 11 is disposed at a substantially middle position of the outer cable fixing unit 101.

[3] Tension and Fixation of PC Steel Wire For fixing the PC steel wire 1, a fixing tool 2 including a plurality of wedges 3 and anchor disks 4 is prepared. The wedge 3 is a member that becomes a wedge shape by combining a plurality of divided pieces (three in this example) formed of a high-rigidity material such as SCM415H, and the stranded wire 10 of the PC steel wire 1 is connected from the outer peripheral side. A member to be gripped. The wedge 3 is fitted into a wedge hole 40H of the anchor disk 4 described below.

  The anchor disk 4 is a substantially cylindrical member, and is made of a highly rigid material such as S45C so that the tension of the PC steel wire 1 can be transmitted to the outer cable fixing unit 101 (see also FIG. 4). ). The anchor disk 4 is provided with a plurality of wedge holes 40H, through holes 45H, and screwing holes 49H penetrating in the thickness direction. The wedge hole 40H includes a tapered portion into which the wedge 3 is fitted, and a straight hole portion having a uniform inner diameter continuous with the tapered portion. The entire surface of the anchor disk 4 excluding the tapered portion is rust-proofed by epoxy coating or the like.

  In order to fix the PC steel wire 1 using these fixing tools 2, first, the anchor disk 4 is attached to the PC steel wire 1 protruding from the anchor plate portion 50. At the time of the attachment, the PC steel wire 1 is inserted into the wedge hole 40H of the anchor disk 4.

  Next, the jack is attached to the jack attachment hole JH of the anchor plate portion 50, and the PC steel wires 1 are tensioned one by one. The wedge 3 is attached to the outer periphery of the PC steel wire 1 after the tension, and it is driven into the wedge hole 40H to fix the PC steel wire 1. This operation is performed on all the PC steel wires 1, and the jack is removed.

[4] Attaching the rust prevention cap The rust prevention cap 6 includes a cylindrical small-diameter portion 60 sealed at one end, a large-diameter portion 61 formed continuously from the small-diameter portion 60, and a large-diameter portion 61. And a flange portion 6F formed at the opening end of the (see also FIG. 5). The small-diameter portion 60 is a portion that covers the stranded wire 10 of the PC steel wire 1 protruding from the anchor disk 4 from the outer peripheral side. The large diameter portion 61 is a portion that covers the outer periphery of the anchor disk 4 attached to the anchor plate portion 50 and the stranded wire 10 protruding from the anchor disk 4. The flange portion 6 </ b> F is a portion that functions as an attachment portion for attaching the rust prevention cap 6 to the anchor plate portion 50. The flange portion 6F is provided with a plurality of screw holes 6FH arranged at intervals in the circumferential direction. The position of the screwing hole 6FH corresponds to the position of the screwing hole 50H of the anchor plate portion 50.

A brittle resin discharge port 6 _OUT is provided in the vicinity of the closed end of the small diameter portion 60 of the rust prevention cap 6, and a brittle resin second injection port 6 _IN is provided in the large diameter portion 61. The rust preventive cap 6 is attached to the anchor plate portion 50 of the disk receiver 5 so that the discharge port 6 _OUT faces upward (preferably vertically upward) (necessarily, the second injection port 6 _IN is horizontal). Also face down). When the rust prevention cap 6 is attached, a ring-shaped rubber packing 6P (FIG. 2) is sandwiched between the rust prevention cap 6 and the anchor plate portion 50 to improve the water-stopping property of the part.

[5] Filling / curing of brittle resin The members 71, 72, 73, 74, 72, 71 (the arrangement of the symbols is the fitting order) previously fitted to the right side of the water stop 53 are assembled to the water stop 53. Thus, a water stop structure for sealing the water stop portion 53 is completed. Specifically, the water stop structure in the present embodiment is the entire portion on the right side of the drawing surface from the partition portion 51S. In the following description, reference is basically made to FIG. 2, and other drawings are referred to if necessary.

  The packing 71 is a disk-shaped member made of an elastic material such as rubber, and has insertion holes for PC steel wires 1 corresponding to the number of PC steel wires 1. The packing 71 is provided in a pair with a pair of spacers 72 and 72 described below interposed therebetween. The outer diameter of the packing 71 is smaller than the inner diameter of the end portion of the water stop portion 53, and therefore the packing 71 disposed on the disk receiver 5 side is fitted into the end portion of the water stop portion 53.

  As shown in FIG. 6, the spacer 72 is a disk-shaped member made of a rigid material such as high-density polyethylene having a recess 72 </ b> C, and the PC steel wire 1 corresponding to the number of PC steel wires 1 is inserted into the recess 72 </ b> C. A hole 72CH is formed. In the present embodiment, a pair of spacers 72 are provided, and the recesses 72C of the spacers 72 and 72 are arranged to face each other. The outer diameter of the spacer 72 is smaller than the inner diameter of the end portion of the water stop portion 53, and therefore, the spacer 72 disposed on the disk receiver 5 side is fitted into the end portion of the water stop portion 53.

  The leakage prevention plate 73 is a disk-shaped member made of an elastic material such as special synthetic rubber, and has insertion holes for PC steel wires 1 corresponding to the number of PC steel wires 1. The outer diameter of the leak-proof plate 73 is slightly smaller than the inner diameter of the concave portion 72C of the spacer 72 shown in FIG. 6, and the leak-proof plate 73 fits between the concave portions 72C of the pair of spacers 72 arranged in opposition. Include.

  The pressing member packing 74 is a ring-shaped member made of an elastic material such as special synthetic rubber, and the inner diameter thereof is larger than the outer diameter of the leakage prevention plate 73. Therefore, the pressing member packing 74 is disposed on the outer peripheral side of the leakage prevention plate 73 at the same position as the leakage prevention plate 73 in the longitudinal direction of the PC steel wire 1.

The pressing member 75 is a member having substantially the same shape as a portion from the partition portion 53 </ b> S to the end portion of the water stop portion 53 of the disk receiver 5. Specifically, as shown in FIG. 7, it is a disk-shaped member made of a highly rigid material such as stainless steel, and includes a concave portion 75C and a flange portion 75F formed at the opening side end of the concave portion 75C. In the recess 75 </ b> C, insertion holes 75 </ b> CH for PC steel wires 1 corresponding to the number of PC steel wires 1 are formed. On the other hand, the flange portion 75F total of 12 screw hole 75FH ₁ are formed to be arranged at substantially equal intervals in the circumferential direction. This screwing hole 75FH ₁ corresponds to the screwing hole 53FH of the flange part 53F of the water stop part 53 shown in FIG. 3, and is used when the pressing member 75 is attached to the water stop part 53 of the disk receiver 5. Further, the four positions of the upper and lower left and right flange portions 75F, disassembling screw hole 75FH ₂ to be used when dismantling water cutoff structure is formed. There is no screw hole corresponding to the disassembly screw hole 75FH ₂ in the water stop portion 53 of the disk receiver 5, so if a bolt is screwed into the disassembly screw hole 75FH ₂ , the tip of the bolt is stopped against the water stop portion 53. Is done. Since the inner circumferential surface of the dismantling screw hole 75FH ₂ are cut screw groove, as if we are screwed bolts, the pressing member 75 is fed in a direction away from the 5 receiving the disk.

  In order to assemble the members 71, 72, 73, 74, 72, 71 described above, the pressing member 75 is screwed to the flange portion 53 F (see FIG. 3) of the water stopping portion 53, and the pressing member 75 and the water stopping portion 53 are fixed. The leakage preventing plate 73 is compressed between the partition portion 53S. The compressed leak-proof plate 73 expands radially outward and inward of the insertion hole of the leak-proof plate 73, and the inner peripheral surface of the insertion hole of the leak-proof plate 73 is in close contact with the outer peripheral surface of the PC steel wire 1. . As a result, the inside of the disk receiver 5 is sealed with the leakage prevention plate 73 as a boundary. Note that, when the leakage preventing plate 73 is compressed, the pressing member packing 74 on the outer periphery thereof is also compressed between the flange portion of the water stopping portion 53 and the flange portion of the pressing member 75. The holding member packing 74 plays a role of improving water-stopping of the water-stopping structure by carrying out water-stopping on the outer peripheral side of the leakage-preventing plate 73 and suppressing the leakage-preventing plate 73 from spreading outward in the radial direction. Have.

Once members 71, 72 and 73, 74, 72 and 71 assembly is completed, and injecting the brittle resin from the first inlet _{5 IN} (kept closed and the second inlet _{6 IN,} outlet _{6 OUT} is left open ). Brittle resin injected from the first inlet 5 _IN enters the space between the partition portion 53S and the partition portion 51S, from entering the gap between the PC steel wire 1 from which the tube 54. Further, the gap enters between the gap between the anchor disk 4 and the anchor plate portion 50 and the split piece of the wedge 3 from the gap, and is discharged into the rust prevention cap 6 through the through hole 45H of the anchor disk 4. When the rust prevention cap 6 is filled with the brittle resin and the brittle resin overflows from the outlet 6 _OUT , the injection of the brittle resin from the first inlet 5 _IN is terminated. Thereafter, when the brittle resin is cured, the fixing structure α of the outside cable of the present invention in which the rust preventive body 9 is formed on the entire movement path of the brittle resin is completed.

Note that when injecting a brittle resin, kept closed the first inlet 5 _IN, may be injected brittle resin from the second inlet 6 _IN. In that case, brittle resin injected from the second inlet 6 _IN, as well is filled into rust cap 6, the partition plate follows the reverse route and when injected brittle resin from the first inlet 5 _IN It flows between 51S and 53S. Of course, it is also possible to inject a brittle resin from both the first inlet 5 _IN and the second inlet 6 _IN.

<Refilling brittle resin>
Since the PC steel wire 1 provided in the fixing structure α of the outer cable completed through the steps described above can be disassembled as described above, the rust preventive body 9 responsible for the rust prevention of the PC steel wire 1 can be disassembled. I can be nervous again. However, if the PC steel wire 1 is re-tensioned, the rust preventive body 9 collapses into a plurality of pieces, and various large and small gaps are formed between the pieces. Therefore, after fixing the re-tensioned PC steel wire 1, the brittle resin is refilled and the gaps between the pieces are filled with the brittle resin to rebuild the rust preventive body 9.

  Here, a piece of the rust preventive body 9 generated by re-tensioning of the PC steel wire 1 may enter a member gap such as a gap between the wedge 3 and the PC steel wire 1 when the PC steel wire 1 is re-fixed. However, even if the fragments enter the gap between the members, the fragments are compressed between the wedges 3 and between the wedges 3 and the anchor disks 4 when the wedges 3 holding the PC steel wire 1 are fitted into the wedge holes 40H. Collapse. Since the broken brittle resin is expelled from the gap between the members, fixing of the PC steel wire 1 is not hindered. If a resin having a higher tensile strength than the brittle resin constituting the rust preventive body 9 is sandwiched between the member gaps, there is a possibility that fixing of the PC steel wire 1 may be hindered.

When the refill brittle resin, may be filled with a brittle resin from both the first inlet 5 _IN and the second inlet 6 _IN. This is because the brittle resin can be filled into the gaps between the pieces efficiently and reliably. Here, since the brittle resin before curing is a low-viscosity liquid, the brittle resin is completely filled in the gaps between the pieces.

  Note that the present invention is not limited to the above-described embodiment, and can be modified as appropriate without departing from the gist of the present invention. For example, in the above-described embodiment, the fixing structure for an external cable of the present invention is applied to fixing an external cable for reinforcing and repairing an existing concrete structure later, but the concrete structure is reinforced when the concrete structure is constructed. The fixing structure of the outer cable of the present invention may be applied to fixing the outer cable.

  The fixing structure of the external cable of the present invention can be suitably used for reinforcing a concrete structure.

100 Bridge (concrete structure)
101 Outer cable fixing section 110 Deviator α Outer cable fixing structure 1 PC steel wire (outer cable)
10 Stranded wire 11 Coating 2 Fixing tool 3 Wedge 4 Anchor disk 40H Wedge hole 45H Through hole 49H Screw hole 5 Disk holder 50 Anchor plate part 50C Recess 50H Screw hole JH Jack attachment hole 51 Cylindrical part 53 Water stop part 51S , 53S Partition part 53SH Insertion hole 53F Flange part 53FH Screw hole 54 Tube 5 _IN 1st inlet 6 Rust prevention cap 6P Packing 6 _IN 2nd inlet 6 _OUT outlet 60 Small diameter part 61 Large diameter part 6F Flange part 6FH Screw fixing hole 71 Packing 72 Spacer
72C Concave part 72CH Insertion hole 73 Leakage prevention plate 74 Packing for pressing member 75 Holding member 75C Concave part 75CH Insertion hole 75F Flange part 75FH ₁ Screw fixing hole 75FH ₂ Screw hole for disassembly 9 Rust prevention body

Claims (8)

A plurality of strained PC steel wires;
A fixing tool including a plurality of wedges for individually holding the PC steel wires, and an anchor disk having a plurality of wedge holes into which the wedges are fitted;
A concrete outer cable fixing portion to which the PC steel wire is fixed by the fixing tool;
With
A fixing structure for an outer cable that reinforces the concrete structure by applying tension to each PC steel wire to the concrete structure via the outer cable fixing portion,
Covering the end of the anchor disk, the wedge exposed from the anchor disk and the PC steel wire, and comprising a rust preventive body interposed between the outer cable fixing portion and the PC steel wire,
The fixing structure for an outer cable, wherein the rust preventive body includes a post-curing brittle resin.   2. The fixing structure for an outer cable according to claim 1, wherein the brittle resin has a tensile strength of 70 to 200 kPa.   The outer cable fixing structure according to claim 1, wherein the outer cable fixing portion is retrofitted to a side surface of the concrete structure. A disk receiver embedded in the outer cable fixing section, and distributing the pressure of the anchor disk to the outer cable fixing section;
The disc receiver is
A cylindrical portion provided through the outer cable fixing portion, and through which the PC steel wire is inserted;
An anchor plate portion provided on one end side of the cylindrical portion, with which the anchor disk is brought into contact;
A water stop portion provided on the other end side of the cylindrical portion, and partitioning an internal space of the cylindrical portion from an external space;
With
The outer cable fixing structure according to any one of claims 1 to 3, wherein the rust preventive body covers an outer periphery of the PC steel wire inside the cylindrical portion. On the side where the anchor disk is arranged in the outer cable fixing portion, the anchor disk, and a rust prevention cap that covers the PC steel wire protruding from the anchor disk from the outer peripheral side,
The fixing structure for an outer cable according to any one of claims 1 to 4, wherein the rust prevention body is filled in the rust prevention cap.   The outer cable fixing structure according to claim 5, further comprising a first inlet for the brittle resin at a position exposed from the outer cable fixing portion in the water stop portion.   The outer cable fixing structure according to claim 5, wherein a second injection port for the brittle resin is provided at a position near the anchor disk in the rust prevention cap. In the tubular part, comprising a tubular body for individually storing each PC steel wire,
The internal space of the tubular body is partitioned from the space between the outer peripheral surface of the tubular body and the inner peripheral surface of the cylindrical portion,
The fixing structure for an outer cable according to any one of claims 5 to 7, wherein an inner space of the tube body is filled with the rust preventive body.

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