JP2013113036A - Multiple anticorrosion cable and ground anchor tendon using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To increase the reliability of the cutoff of a cable to be used for the reinforcement application of a concrete structure, and to prevent the intrusion of a corrosion factor to the inside by performing highly reliable cutoff even when a longitudinal anchor tendon is constituted.SOLUTION: A plurality of tendons 2 each of which has been anticorrosion proofed are twisted and bundled into one, and a shaping material 3 for averaging the outer diameters of a cable is arranged across the full length of the cable between the adjacent tendons 2 in the outermost periphery, and a cutoff 4 filling a gap between the tendons and the surrounding gap of the shaping material 3 is arranged across a length range which is 300 mm or more in at least one end of the cable, and a sheath 6 made of synthetic resin, lubricant 7, and a second sheath 8 are arranged in the outer periphery of the flux of the tendons. The gap between the tendons and the surrounding gap of the shaping material may be packed with a packing material 5 across the full length of the cable instead of the cutoff 4.

Description

  The present invention relates to a multiple anticorrosion cable used to reinforce a concrete structure such as a ground or a bridge, and a ground uncurtain dong that uses the same to improve durability and downsize.

  The first ground uncurtain dong (hereinafter simply referred to as tendon) is used to reinforce and raise dams, breakwaters, and seawalls. This tendon is configured by bundling a plurality of tendons. A composite material cable that can be used as a tendon or a bridge PC tension member is disclosed in, for example, Patent Document 1 below.

  In the composite material cable disclosed in Patent Document 1, a plurality of tendons are bundled and covered with a synthetic resin sheath (sleeve), and a water stop is attached to both ends of the sheath to fill the entire sheath. Injecting. As the filler, an expandable material such as expandable cement is used, and the cable is fixed by friction caused by the expansion pressure of the filler.

Japanese Patent No. 4288122

  The composite material cable disclosed in the above-mentioned Patent Document 1 is a specification in which a multi-cable bundle of tendon materials is inserted into a sheath, and after filling the tendon material, the filler is injected into the sheath. Since there is a gap between the sheath and the tendon in the sheath, there is no particular problem when applied to a tendon with a total length of several tens of meters (about 30 m) in use as a ground anchor. In the case of a tendon that is long and is arranged vertically for the purpose of reinforcing a dam, the following problems arise.

  That is, the tendon having a total length exceeding 30 m increases the pressure of the grout injected after insertion of the water in the drilled hole or the tendon for forming the anchor body (for example, the pressure of the grout at the total length of 100 m is 2 MPa. Therefore, anxiety remains about water-stopping. In the unlikely event that the water stoppage is not maintained, if the grout flows into the sheath, tension cannot be obtained. Despite that concern, grout injection is risky because visual confirmation is not possible. There is also a concern that the sheath is deformed by the grout pressure.

  When the reliability of water stoppage is low, the corrosion factor (mainly water) penetrates into the inside through the gap between the tension members from the end of the cable, and the durability of the tension cable and the tendon using the same decreases. Further, when the sheath is deformed, the sheath is broken or the cable tension is disturbed.

  Accordingly, the present invention increases the reliability of water stoppage for cables used for reinforcement of concrete structures and the like, and in particular, highly reliable water stoppage is performed even when long uncurtain dongs are configured. Therefore, it is an object to prevent the intrusion of corrosion factors into the interior.

  In order to solve the above problems, in the present invention, the cable for reinforcing a concrete structure is configured as a multiple anticorrosion cable as follows. That is, a plurality of tension members each anticorrosion-processed are twisted and bundled together, and a shaping material that equalizes the outer diameter of the cable is disposed over the entire length of the cable between adjacent tension members on the outermost periphery. Further, at least one end of the cable, a water stop material that fills the gap between the tension members and the gap around the shaping material is arranged over a length range of 300 mm or more, and the synthetic resin is placed on the outer periphery of the bundle of the tension materials. A first sheath was provided.

  In addition, as the shaping material, a strip material such as PP (polypropylene) is suitable, and a material such as urethane foam or clay can be used for shaping. The water-stopping material is preferably a water-expandable resin such as a urethane resin, and a silicone resin or the like can also be used.

  This multi-corrosion-proof cable is additionally provided with a filler such as grease or wax that fills the gaps between the tension members and the gap around the shaping material, and the filler is used as an area for installing the water-expandable waterproofing material. You may arrange | position in the area | region except.

  In addition, in the case of using the filler, the filler is disposed over the entire length of the cable instead of disposing the water-expandable water stop material at least at one end of the cable, You may make it the structure which fills the clearance gap around a shaping material only with a filler.

  In the case of a long cable, the method of press-fitting a filler into the inside of the sheath after construction of the sheath cannot enclose a filler such as grease or wax in a length range that can sufficiently ensure the reliability of water stoppage. Therefore, in the present invention, the tension material previously applied with the filler is twisted, and the shaping material previously applied with the filler is disposed, and then the sheath is applied. As a result, the filler can be filled in a length region that cannot be sealed by press fitting.

  In this multi-corrosion-proof cable, it is preferable that the sheath is brought into contact with the outermost peripheral tension member in the tension member bundle to be integrated with the tension member bundle. According to this structure, the bundle of the tension material and the sheath behave together when tensioned, and the internal water-stopping material and filler are stably held, and the water-stopping material and filler prevent the invasion of corrosion factors. Is unlikely to occur.

  When the sheath used in the multiplex cable is a first sheath, a lubricant is applied to the outer periphery of the first sheath, and a second sheath of synthetic resin surrounding the entire outer periphery including the lubricant is provided on the outermost periphery. Is also preferable. This is because even if the second sheath is constrained by the solidified grout, the first sheath is not fixed. Therefore, the tension material is not obstructed from being stretched, and the concrete structure to be reinforced is stably compressed. Can be added.

  This invention has an anchor body length part integrally fixed to the bottom side region of the anchor installation hole, and a free length part in which the ground surface side is fixed to the anchor part of the anchor head continuously to the anchor body length part, The anchor body length part and the free length part consisted of a series of tendon materials bundled with multiple tendon materials, and a protective body covering the outer periphery of tendon was installed at the boundary between the anchor body length part and the free length part A ground uncurtain dong is also provided.

  The tendon has the structure of the multi-corrosion-proof cable of the present invention in a region (required portion) excluding the portion fixed to the anchoring portion of the anchor head of the free length portion, and the one having a water-expandable water stop material. The water-swellable water-stopping material is applied so as to be placed under the free length portion, and has a characteristic.

  In addition, the tendon that consists of a plurality of cables that are bundled with a plurality of tendons and sheathed on the outer periphery, the loss of the placement of the tendons in the circumscribed circle increases the tendon outer diameter. In addition, friction is generated between the cables, and uniform tensioning of all the cables constituting the tendon becomes difficult.

  On the other hand, the tendon of the present invention has a structure in which a plurality of tendons are twisted together and bundled together and the outer periphery thereof is covered with a sheath, so that the arrangement efficiency of the tendons within the circumscribed circle is increased and the tendon outer diameter is increased. Can be reduced. In addition, since the bundled tension members behave integrally, the tension force of each tension material can be made uniform.

  The multiple anticorrosion cable of the present invention combines a plurality of tendon materials each of which is anticorrosive processed. In addition, a shaping material that equalizes the outer diameter of the cable between adjacent tension members on the outermost circumference is arranged over the entire length of the cable, and a gap between the tension materials and a gap around the shaping material are at least at one end of the cable. It is filled with a water-stopping material to be provided or a filler provided over the entire length of the cable, so that stable water-stopping is achieved even in applications where the pressure applied to the inside of the cable is high.

  When the gap inside the cable end is filled with a water-expandable water-stopping material, the water-stopping material absorbs moisture that is about to enter the cable and expands, thereby enhancing the sealing performance of the gap. In addition, the one that fills the gap with only the filler is filled with a filler in a length (for example, 30 m or more) that is impossible with the method of press-fitting after the sheath construction. The tendon of the present invention adopting the cable structure for the free length portion prevents the corrosion factor from entering the inside of the cable and increases the reliability of corrosion prevention.

  Moreover, since the shaping material which functions as a spacer is arrange | positioned in the clearance gap between the adjacent tension materials of outermost periphery, the deformation | transformation of the sheath by a grout pressure etc. is suppressed and the malfunction accompanying a sheath deformation | transformation is avoided.

Sectional drawing which shows the basic form of the multiplex anticorrosion cable of this invention Cross section of multiple anticorrosion cable with double sheath on outer periphery Cross section of anticorrosive tension material Sectional drawing which shows an example of the ground uncurtain don of this invention

  Hereinafter, based on FIGS. 1 to 4 of the accompanying drawings, embodiments of the multiple anticorrosion cable and the ground uncurtain don of the present invention will be described.

  An example of the multiple anticorrosion cable of the present invention is shown in FIGS. The multiple anticorrosion cable 1 in FIG. 1 is formed by twisting and bundling a plurality of tension members 2 each of which is anticorrosion processed. Moreover, the shaping material 3 which equalizes the outer diameter of a cable is arrange | positioned over the full length of a cable in the recessed part of the outer periphery of a tension material bundle.

  Further, a waterproofing material 4 that fills the gap between the tension members 2 and 2 and the gap around the shaping material 3 at least at one end of the cable is arranged over a length range of 300 mm or more, and the shaping material 3 and the outer periphery The entire outer periphery including the water blocking material 4 is covered with a synthetic resin sheath 6 to complete a multiple anticorrosion cable.

  As shown in FIG. 3, the tension material 2 is made of a PC steel wire 2a covered with a synthetic resin 2b such as epoxy resin or polyethylene to prevent rusting. This anticorrosive tension material 2 is twisted so as to have a cross section approximated to a perfect circle as much as possible, and bundled together, and the outer diameter of the cable (bundled tension material) between adjacent tension materials 2 and 2 on the outermost periphery. A shaping material 3 that equalizes the outer diameter of the tension material 2 is vertically provided, and the depression between the tension materials 2 and 2 is filled with the shaping material 3. Note that the PC steel stranded wire 2a is not limited to the one coated with a synthetic resin, and a galvanized one and one having no anticorrosion processing are applicable.

  As the shaping material 3, a PP rope is used here, but a strip material such as a fiber rope formed of a resin other than PP or a natural fiber, or a foamed resin such as urethane foam may be used.

  The water-stopping material 4 uses a water-expandable urethane-based resin, which is ideally the entire length, but considering the economic efficiency, it is in a length range of 300 mm to 1000 mm at least at one end of the cable. It is provided in the extended area.

  The water stop material 4 is disposed in the gap between the tension members 2 when twisting the tension members 2, and further disposed around the shaping material when the shaping material is disposed, and then the sheath 6 is extruded. Covered by molding.

  A gap between the tension members and a gap around the shaping material 3 in a region other than the region where the water stop material 4 is installed can also be filled with the filler 5 by additionally installing the filler 5. This structure is effective when higher water stoppage reliability is required.

  The filler 5 may be grease or wax having moderate viscosity. Since the installation range of this filler is limited in press-fitting after sheath construction, the tension material previously coated with the filler is twisted, and the filler 5 is preliminarily placed on the outer periphery of the twisted tension material 2 bundle. The applied shaping material 3 is arranged, and then the first sheath 6 is applied.

  In the cable in which the filler 5 is provided by this method, the filler 5 is arranged over the entire length of the cable, and the gap between the tension members and the gap around the shaping material 3 are formed only by the filler 5 without using the water stop material. The structure may be filled with.

  In the multiple anticorrosion cable 1 of FIG. 2, the sheath 6 of the multiple anticorrosion cable 1 of FIG. 1 is considered as a first sheath, and a lubricant 7 such as grease is applied to the outer periphery of the first sheath, and the lubricant 7 is included. A synthetic resin second sheath 8 is further provided on the entire outermost periphery.

  When using a multiple anticorrosion cable as an uncurtain dong or the like, the outermost sheath is restrained by a hardened grout. If the sheath is applied twice, even if the second sheath 8 is restrained, the first sheath 6 can slide relative to the second sheath, so that stable tension is ensured and the tension material is re-tensioned. Can be done without any problem.

  Although the 2nd sheath 8 is useful also to make the 1st sheath 6 hard to tear, it may be unnecessary depending on the use of a multiple anticorrosion cable.

  The multiple anticorrosion cable 1 in FIG. 1 and FIG. 2 is made by twisting together a plurality of anticorrosive tension materials so as to have a cross section approximate to a perfect circle by including a shaping material, The outer diameter can be kept small.

  FIG. 4 is a specific example of a ground uncurtain dong constructed by partially applying the structure of the multiple anticorrosion cable of FIG. This ground uncurtain dong 10 has an anchor body length portion 11 that is integrally fixed to the bottom side region of the anchor installation hole 20, and a free length in which the ground surface side is continuously fixed to the anchor portion fixing portion 13 of the anchor body length portion. Part 12.

  The anchor body length part 11 and the free length part 12 are a series of tensions in which a plurality of tension members 2 each of which is anticorrosion-processed are twisted and bundled together at necessary places (excluding the ground surface side of the free length part 12). It consists of materials.

The anchor body length portion 11 covers a bundle of tendons with a corrugated sheath 11a, and a centering member 11b that holds the anchor body length portion 11 at the center of the anchor installation hole 20 is installed in the middle of the outer periphery of the corrugated sheath 11a. The spacers 11c are arranged at appropriate intervals between the bundle of the tension material and the corrugated sheath 11a, and a filler such as cement grout is injected into the space secured by the spacer 11c, thereby integrating the tension material and the corrugated sheath 11a. .
As a method of injecting cement grout into the corrugated sheath 11a, there are a method of injecting the ground uncurtain dong into the anchor installation hole 20, and a method of injecting the ground uncurtain dong into the anchor installation hole 20 after the insertion. In the case of inserting the ground uncurtain dong, a method of injecting directly into the corrugated sheath 11a with a grout hose and a method of injecting the grout 15 into the anchor installation hole 20 with the lower end of the corrugated sheath 11a as an opening. There is also.

  In addition, the free length portion 12 has the structure of the multiple anticorrosion cable of FIG. 2 installed in the region other than the ground surface side (region where the tension material is bundled) fixed to the fixing portion 13 and the water-expandable water stop material 4 is installed. This is applied in such a state that the portion is disposed below the free length portion 12, and a lubricant encapsulating O-ring 12a for closing the mouth of the second sheath 8 is mounted on the outer periphery of the upper end and the lower end of the multiple anticorrosion cable. .

  Further, a centering member 12b is installed on the outer periphery in the middle of the length of the cable, and on the ground surface side of the free length portion 12, a water-stop O-ring 12c for watertight sealing, a trumpet sheath 12d, and a heat shrinkable tube 12e is provided.

  Further, the heterogeneous connecting pipe that connects the corrugated sheath 11a and the second sheath 8 of the free length portion to the boundary between the end of the anchor body length portion 11 on the ground surface side and the bottom end portion of the anchor installation hole of the free length portion 12 The protector 14 which combined 14a and the heat contraction tube 14b is provided.

  In addition, the fixing unit 13 arranges the anchor disk 13c on the anchor plate 13a via the water stop plate 13b, and fixes each tension material to the anchor disk 13c using the wedge 13d. Is covered with a cap 13e.

  The tendon constructed as described above is placed in the anchor installation hole 20, and a leak-proof plate (not shown) and a construction base (also not shown) are installed at the entrance of the anchor installation hole 20, The anchor disk 13c is temporarily held at a position that does not interfere with the grout injection, and the grout 15 is injected into the anchor installation hole 20. After that, an anchor plate 13a, a water stop plate 13b, and an anchor disk 13c are arranged. After the grout 15 is solidified, the tension members 2 are tensioned and fixed at the fixing portion 13, and the fixing portion is covered with a cap 13e for reinforcement. Configure the anchor.

  The lower end side of the free length portion 12 has a closed mouth. However, in applications where the grout pressure is increased, it is required to further improve the reliability with respect to prevention of corrosion factor intrusion. In the tendon of the present invention, the gap in the cable on the lower end side of the free length portion is sealed by the water blocking material 4, or the entire area excluding the ground surface side fixed to the anchor head of the free length portion 12 (conventional anticorrosion) Since a length range that is impossible with a cable) is sealed with a filler, stable water stoppage is achieved even when the applied pressure is increased, thereby increasing the reliability of corrosion prevention.

  In addition, since tendon is made up of a single cable, there is no friction between the tendon and the cable, which is a problem with tendons that are made up of a plurality of tendons that are individually sheathed. Uniform tension of each tendon is also possible.

  Furthermore, suppose now that the epoxy strand 19S15.2 (a strand having an outer diameter of 15.2 mm obtained by S twisting 19 strands) is adopted, the outer diameter of the sheath 6 is φ95 mm, and the outer diameter of the second sheath 8 is The diameter is φ105 mm, and the diameter of the anchor installation hole for storing it is small. For example, the outer diameter of the anchor installation hole 20 in this case may be φ225 mm, and the drilling cost of the anchor installation hole can be reduced.

  In addition, although the multi-corrosion-proof cable of this invention can be utilized suitably for the ground uncurtain dong used for reinforcement and raising of a dam anchor or a seawall, a use is not limited to it. It can also be used as a general tension material for ground anchors, a reinforcing material for concrete structures, and a suspension material for bridge girders.

DESCRIPTION OF SYMBOLS 1 Multi-corrosion-proof cable 2 Tension | tensile_strength material 2a PC steel strand 2b Synthetic resin 3 Shaping material 4 Water-expandable waterproofing material 5 Filler 6 Sheath 7 Lubricant 8 Second sheath 10 Ground uncurtain don 11 Anchor body length part 11a Corrugated sheath 11b Centering Member 11c Spacer 12 Free length portion 12a Lubricant-sealed O-ring 12b Centering member 12c Water-stopping O-ring 12d Trumpet sheath 12e Heat shrinkable tube 13 Fixing portion 13a Anchor plate 13b Water-stop plate 13c Anchor disk 13d Wedge 13e Cap 14 Protective body 14a Heterogeneous connecting pipe 14b Heat shrinkable tube 15 Grout 20 Anchor installation hole

Claims (7)

  A plurality of tension members (2) each coated with anticorrosion are twisted and bundled together, and a shaping material (3) that equalizes the outer diameter of the cable between adjacent tension members (2, 2) on the outermost periphery is cabled Further, the water stop material (4) that fills the gap between the tension members (2) and the gap around the shaping material (3) at least at one end of the cable has a length range of 300 mm or more. A multi-corrosion-proof cable for reinforcing concrete structures in which a sheath (6) of synthetic resin is provided on the outer periphery of the bundle of tendons.   The multiple anticorrosion cable for reinforcing a concrete structure according to claim 1, wherein a water-expandable resin is used as the water blocking material (4).   A filler (5) that fills the gaps between the tension members (2) and the gap around the shaping material (3) is additionally provided, and the filler (5) is provided as an installation area for the waterstop material (4). The multiple anticorrosion cable for reinforcing a concrete structure according to claim 1 or 2, which is disposed in an excluded region.   A plurality of tension members (2) each coated with anticorrosion are twisted and bundled together, and a shaping material (3) that equalizes the outer diameter of the cable between the outermost tension members (2) is stretched over the entire length of the cable. Furthermore, a filler (5) that fills the gaps between the tension members (2) and the gaps around the shaping material (3) is arranged over the entire length of the cable, and the outer circumference of the bundle of tension members A multi-corrosion-proof cable for reinforcing concrete structures with a synthetic resin sheath (6).   The multiple anticorrosion cable for reinforcing concrete structures according to any one of claims 1 to 4, wherein the sheath (6) is integrated with the bundle of the tendon (2).   The lubricant (7) is applied to the outer periphery of the sheath (6), and a synthetic resin second sheath (8) surrounding the entire outer periphery including the lubricant is provided on the outermost periphery. A multiple anticorrosion cable for reinforcing a concrete structure according to any one of the above. An anchor body length part (11) integrally fixed to the bottom side region of the anchor installation hole (20), and a free length part that is continuous to the anchor body length part and whose ground surface side is fixed to the anchoring part (13) of the anchor head (12), and the anchor body length part (11) and the free length part (12) are constituted by a series of tension members each of which is bundled with a plurality of tension members (2) each subjected to anticorrosion processing, A ground uncurtain dong in which a protective body (14) covering the outer periphery of tendon is installed at the boundary between the anchor body length part (11) and the free length part (12),
The structure of the multiple anticorrosion cable (1) according to any one of claims 1 to 6, in a region excluding a portion fixed to the anchor portion (13) of the anchor head of the free length portion (12), About the thing which has a water stop material (4), the said ground water stop material (4) is the ground uncurtain don applied by the arrangement | positioning placed under a free length part (12).

Images