JP2009084941A - Pc steel bar anchoring method in after-bond method, and device used for implementing the method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a PC steel bar anchoring method technique in an after-bond method which can be applied to a small scale building by realizing miniaturization of an anchoring device, reducing its weight and also reducing the concrete cut-out part for tensile anchoring of a PC steel bar, in the after-bond method for tensile anchoring of a prestressed concrete building with a single PC steel bar. <P>SOLUTION: An anchoring body 1, equipped with a cylindrical part 1T continued rearward from a vertically arranged bearing plate 1A and having a conically-shaped insertion hole H1, is integrated with concrete C0 by embedding the main part of the bearing plate 1A in the concrete C0. A tapered nut 2 with a screw hole H2 is inserted into the insertion hole H1 of the anchoring body 1, and a coupler 3 having the tip end of the PC steel bar 6 being screwed in/fixed to the latter half part of the coupler is screwed into the tapered nut. The joint bolt 16B in the tensioning device is screwed into the first half part of the coupler 3 to be tensioned, and the tapered unit 2 is fastened in the prescribed tensioning state of the PC steel bar 6, to be seated within the insertion hole H1 of the anchoring body 1. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a method for fixing a tension steel bar (PC steel bar) in an afterbonding method for a prestressed building, a fixing tool used for carrying out the method, and a pocket for forming a concrete notch for PC steel bar tension. It relates to the former and belongs to the technical field of architecture.

In recent years, the use of prestressed technology for concrete structures has become widespread, and various PC steel materials have been developed and implemented.
In addition, after-bonding the PC steel material into the concrete building, the after-bond method of filling the grout mortar around the PC steel material is also commonly used, and the method of adopting a single PC steel rod as the PC steel material is also commonly used. ing.
As a fixing method of the PC steel bar in the after bond method to which the present invention belongs, there is a conventional example shown in FIG.

FIG. 8 is shown in Patent Document 1, and as shown in FIG. 8 (A), a PC steel bar is tensioned and tightened with a nut through a washer against a flat plate-shaped bearing plate. It is.
Then, as shown in FIG. 8 (B), after the formation of the recessed hole in the concrete frame, the bearing plate is coated with resin mortar on the bottom of the recessed hole to adjust the unevenness of the seating surface, and the grout inlet Place the bearing plate equipped, tension the PC steel rod that penetrates the spiral sheath, and fasten the threaded surface of the PC steel rod that protrudes from the bearing plate with a nut through the washer, from the grout inlet of the bearing plate Grout mortar is injected into the spiral sheath, and the PC steel bar is after-bonded with mortar.
Japanese Patent Laid-Open No. 8-319721

  In the conventional steel bar fixing means in the conventional after-bonding method (FIG. 8), the concrete is cast in a form in which the front end of the spiral sheath is in contact with the concrete mold for forming the notched hole. The cast concrete may flow into the spiral sheath from the contact portion between the front end of the sheath and the formwork, and the work of preventing the inflow of concrete to the front end of the spiral sheath before placing the concrete is complicated.

  In addition, for example, when using a 26 mm diameter PC steel bar, the depth of the notch hole in the concrete frame is 5 mm thick, non-adjustable resin mortar thickness, 28 mm bearing plate, 4.5 mm washer, 40 mm nut height, from the nut. The required length of PC steel bar protruding forward, that is, steel bar diameter 26mm, concrete steel cover thickness of PC steel bar 30mm, is a large total of 133.5mm, and the vertical and horizontal dimensions of the bearing plate are 135mm. The defect becomes large, and the large notch hole is not preferable from the strength design surface and the repair repair original surface.

In addition, the tension of the PC steel rod is screwed tension of the tension rod, but if the screwing length of the tension rod is not 40.5mm or more, the thread of the PC steel rod may break, and the tensioned nut front The length of the PC steel bar protruding from the length is 26 mm + 40.5 mm + the amount of extension, and it is necessary to cut the protruding length from the nut of the PC steel bar to the required concrete cover thickness of 30 mm. The cutting operation is a complicated and troublesome operation.
The present invention solves or improves the problems of the conventional after-bonding PC steel bar fixing method at once, adopts a novel PC steel bar fixing tool, under a small concrete notch, and The present invention provides a technique that eliminates the need to cut a PC steel rod in a concrete cutout hole.

  In the present invention, for example, as shown in FIG. 1, a fixing body 1 including a bearing plate 1A having a vertical front end and a cylindrical portion 1T having a reduced diameter that continues horizontally from the bearing plate 1A to the rear is provided. The trumpet sheath 4 is fitted to the rear end of the cylindrical portion 1T, the thread surface S6 at the tip of the PC steel rod 6 penetrating the spiral sheath 5 and the trumpet sheath 4, and the inner periphery and outer periphery are thread surfaces. The coupler 3 is screwed and fixed to the latter half, and the coupler 3 is screwed onto the inner peripheral thread surface S2 of the taper nut 2 so that the taper nut 2 is fitted to the fixing body 1. The pocket former 14 is arranged, the concrete mold is set, the concrete formwork is disassembled after the concrete is hardened, and the screw bolt of the joint member of the tensioning device is formed through the concrete notch 11A formed on the front surface of the bearing plate 1A. 6B is screwed into the front half of the coupler 3, the PC steel rod 6 is pulled out together with the coupler 3 and the taper nut 2, and when the predetermined tension value is reached, the taper nut 2 is tightened into the insertion hole H1 of the fixing body 1. It is a PC steel bar fixing method in the after bond method to be seated.

  In this case, the other end of the PC steel bar 6 only needs to be firmly fixed and gripped. For example, as shown in FIG. 2A, the same fixing body 1, taper nut 2 and coupler 3 as the tension end side are employed. Then, the screw surface S6 of the fixed end of the PC steel rod 6 is screwed into the coupler 3, the coupler 3 is screwed into the taper nut 2, and the taper nut 2 is seated on the fixing body 1, and the fixing body 1 is concreted. The fixing member 1 may be integrated with the concrete frame C0 by being placed in the mold, and the other end side of the PC steel bar 6 may be gripped by the same means as the tensioned end if necessary. If both ends of the PC steel bar 6 are fixed as tension ends, the base end side of the PC steel bar 6 on the extension side can be screwed and fixed to the end of the existing coupler 3 when the precast concrete building is expanded. When both ends of PC steel bar 6 are treated as tension ends Is, with respect to the existing precast concrete building, it is possible to build-on both sides.

Further, the spiral sheath 5 and the trumpet sheath 4 covering the PC steel rod 6 may adopt conventional products, and the end of the trumpet sheath 4 is located after the cylindrical portion 1T of the fixing body 1 as shown in FIG. If the adhesive tape (vinyl tape) 12 is wound around the end of the fixing body cylindrical portion 1T and the trumpet sheath 4 by being fitted to the ends, the inflow of the cast concrete into the trumpet sheath 4 can be prevented.
Further, since the necessary tension amount can be determined in the design stage, the PC steel bar 6 is prepared in advance by taking the elongation amount into consideration, and the tip of the coupler 3 may be prevented from protruding from the front surface 1F of the fixing body in the tension fixing stage. .

Further, the taper nut 2 is in a state in which the coupler 3 in which the tip of the PC steel rod 6 is screwed and held is pulled out to the predetermined tension value of the PC steel rod 6 to the seating position of the insertion hole H1 of the fixing body 1, Since the outer peripheral thread surface S3 of the coupler 3 is tightened, the outer periphery of the front end of the taper nut 2 may be in the form of a nut that receives a rotating action by a conventional ratchet wrench (box wrench). A hexagonal nut 2C is attached to the tip of the nut 2.
Further, for example, as shown in FIG. 1, the pocket former may be configured such that a conical cylindrical sleeve pipe is detachably disposed on the outer surface of the insertion hole H1 on the front surface of the bearing plate 1A, and the outside of the pocket former 14 of the bearing plate 1A. Since the area becomes an embedded area in the concrete and increases the holding force of the bearing plate, the smaller the diameter of the pocket former 14 in contact with the bearing plate 1A, the better.

Therefore, according to the present invention, the fixing body 1 is the vertical bearing plate 1A and the cylindrical portion 1T extending backward, and one PC steel rod 6 is connected to the bearing plate 1A via the coupler 3 and the taper nut 2. Since the coupler 3 and the taper nut 2 can be fixed in a form that does not protrude from the front face 1F of the bearing plate 1A by being inserted into the insertion hole H1 at the center of the bearing section 1A, the front face 1F of the bearing plate 1A has a flat shape. The front concrete cover thickness Sx can be reduced.
Therefore, since the concrete notch formation method using the pocket former, which has been applied only by the unbond method, has been applied to the grout bond method (after bond method), the space-saving concrete notch 11A is fixed by the pocket former. It becomes possible.
The dimension between the bearing plate 1A and the floor slab surface Sf, that is, the covering thickness Sy of the floor slab concrete C0 can be reduced, and the covering thickness Sx of the concrete C0 on the front surface of the bearing plate 1A, that is, the depth Sx of the concrete notch 11A is also obtained. Can be small.

That is, according to the present invention, the fixing body 1 can be integrated into the concrete, and most of the outer periphery of the vertical bearing plate 1A is embedded in the cast concrete C0. Since the Zf and the rear concrete zone Zb are firmly held, the concrete covering thickness Sy on the upper part of the bearing plate 1A can be made thin, which is far more space-saving than the conventional concrete notch for holding the bearing plate (Fig. 8). Since the concrete notch 11A can be made smaller and the concrete notch 11A can be made smaller, it is possible to rationalize the repair and repair work of the concrete notch 11A after the PC steel bar is fixed, and even with a compact anchorage, sufficient concrete A holding force can be applied.
Therefore, the present invention can be applied to the horizontal part and the vertical part of the concrete outer wall, and can be applied between columns having a large amount of reinforcing bars with good workability.
Further, it is easy to prevent the pouring concrete from flowing into the trumpet sheath 4 because the adhesive tape 12 is simply wound.

Further, the tension work of the PC steel bar 6 is carried out by using a tension device (torque wrench) provided with a joint bolt 16B having the same diameter as the PC steel bar 6 and screwing the joint bolt 16B into the coupler 3. In the state where the PC steel rod 6 is fixed to the fixing body 1, the tip of the PC steel rod 6 is located in the rear half of the coupler 3, and unlike the conventional case, the tip of the PC steel rod 6 does not protrude from the bearing plate. In the fixing work of the PC steel bar 6, the extra difficult cutting work of the PC steel bar 6 becomes unnecessary.
Moreover, since the front half of the coupler 3 to which the joint bolt 16B of the tensioning device is screwed and locked can be used for fixing the base end of the PC steel bar on the new extension side when the concrete prestressed building is expanded, Extension construction is also possible.

Further, in the present invention, as shown in FIG. 1, the insertion hole H1 of the fixing body 1 has a small fitting hole H1 ′ whose diameter is expanded to the rear end via the enlarged diameter step portion 1G. It is preferable that the front end of the trumpet sheath 4 is inserted into the fitting hole H1 ′ up to the stepped portion 1G.
In this case, the stepped portion 1G has a stopper function at the tip of the trumpet sheath 4 and the small fitting hole H1 ′ is for guiding and inserting the trumpet sheath 4 into the fixing member cylindrical portion 1T.
Accordingly, the fixing body of the conventional trumpet sheath 4 is provided with a fitting hole H1 ′ at the rear end of the insertion hole H1 of the fixing body 1 via the step portion 1G, as shown in FIG. 1 can be smoothly inserted and inserted into the rear end, and the cast-in concrete inflow prevention structure at the joint portion between the cylindrical portion 1T of the fixing body 1 and the trumpet sheath 4 simply wraps the adhesive tape 12. Can be achieved simply.

Further, in the present invention, as shown in FIG. 1A, the coupler 3 has a bolt insertion hole H3 ′ at the center in the length direction, and a partition bolt 3B is screwed into the bolt insertion hole H3 ′. The tip position of the PC steel rod 6 is preferably defined by the bolt 3B.
The coupler 3 is screwed and fixed to the tip thread surface S6 of the PC steel rod 6 in the latter half, and is screwed and fixed to the bolt shaft 16B of the tensioning device in the front half, and is pulled by the tensioning device of the bolt shaft 16B by the tensioning device. Since the steel rod 6 is a member that pulls out together with the coupler 3, neither the screwing length of the PC steel rod 6 with the screw surface S6 nor the screwing length of the bolt shaft 16B breaks the twist. "is required.

Therefore, the bolt 3B acts as a stopper for the PC steel rod 6 during the screwing operation of the tip thread surface S6 of the PC steel rod 6 into the coupler 3, and the necessity for the latter half of the coupler 3 of the PC steel rod 6; In addition, in order to define a sufficient screwing amount and a necessary and sufficient screwing amount of the coupling bolt 16B to the first half of the coupler, the coupler 3 can be made to have a minimum length and the coupler 3 can be shortened.
Moreover, the coupler 3 after fixing the PC steel bar 6 can be used as a fixing part of the fixed end of the new PC steel bar 6 at the time of extension of the building, with the coupler 3 after the fixing of the PC steel bar 6 being removed by the bolt 3B. Enables rational construction of prestressed buildings.

Further, in the present invention, as shown in FIG. 1A, the pressure bearing plate 1A of the fixing body 1 has a rectangular plate shape and bends backward, and has a rib on the outer periphery in the middle in the longitudinal direction of the cylindrical portion 1T. It is preferable to provide the protrusion 1C.
In this case, the fixing body 1 transmits the tension stress of the PC steel bar 6 to the concrete frame without causing concrete shear failure, and the bearing plate 1A bears the stress uniformly on the effective surface. Therefore, for example, when adopting a 26 mm diameter for a PC steel rod, if it is a square, a support plate having a thickness of 28 mm and a side of 135 mm is required, but in the present invention, the standard of the support plate 1A is A curved form with a radius of curvature of 200 mm and a square plate with a side of 125 mm.

  Therefore, as shown in the operation explanatory view of FIG. 4B, the tensile stress F of the PC steel rod 6 with respect to the curved bearing plate 1A becomes an inclination stress F toward the fulcrum 200 mm behind the bearing plate, and against the bearing plate 1A. The fracture surface where the holding stress f2 and the tensile stress f1 of the concrete C0 act, that is, the inclined surface of 45 ° (135 ° from the reaction line on the opposite side) with respect to the tensile stress F, is located behind the tensile stress line F. Since it inclines backward with the convergence inclination, the distance to the floor slab surface of the fracture surface becomes longer, the holding stress on the bearing plate 1A of the cast concrete C0 increases, and the concrete covering thickness Sy on the upper portion of the bearing plate 1A is Can be small.

Accordingly, the bearing plate 1A bent rearward has a higher holding power of the concrete C0 than the conventional plate-shaped bearing plate, and the covering thickness Sy of the upper surface of the concrete C0 can be made smaller than that of the conventional bearing plate. Introduction of prestressed construction methods to concrete buildings can be streamlined.
Moreover, since the fixing body cylindrical portion 1T is provided with the rib-like protrusions 1C at the outer peripheral intermediate portion, the rib-like protrusions 1C increase not only the strength of the fixing body 1 but also the holding power of the concrete C0. Achieve miniaturization and increased holding power.

In the present invention, as shown in FIG. 4 (A), the taper nut 2 has the front end T2 installed inward from the front surface 1F of the fixing body, and the elongation amount of the PC steel rod 6 is calculated in advance. When the PC steel rod 6 is fixed, the front end T3 of the coupler 3 is preferably fixed inward from the front surface 1F of the fixing body.
The taper nut 2 has an outer peripheral conical surface seated in the insertion hole H1 of the fixing body 1, and the coupler 3 has a front and rear position in the taper nut 2 determined by the extension amount of the PC steel rod 6. .

  Therefore, since both the taper nut 2 and the coupler 3 can be designed so as not to protrude from the fixing body 1 at all times, the fixing body 1 can be arranged and designed only by the necessary concrete covering thickness Sx of the bearing plate 1A, and the conventional washer (FIG. 8). The concrete covering thickness for the steel bar and the protruding steel rod is no longer required, the size of the concrete notch 11A can be reduced, and the diameter, spacing, and length of the spiral bar 8 (FIG. 3) for preventing splitting of the anchoring portion can be reduced. In addition, the workability of the reinforcement of the spiral reinforcement 8 is improved, and it is also advantageous in terms of restoration and repair of the concrete section defect (concrete notch 11A), to a small-scale concrete prestressed building with PC steel bar fixing technology in the grout bond method Can be applied.

In the present invention, after fixing the PC steel rod 6, it is preferable to fill the concrete notch 11A with the non-shrink mortar 11B after protecting the inner circumferential thread surface S3 'of the coupler.
In this case, when the tension of the PC steel bar 6 is fixed, if the front end T3 of the coupler 3 is within the taper nut 2, as shown in FIG. 4A, the front end T2 of the taper nut 2 is adhesively closed with a sheet of cloth, tape or the like. In the case where the front end T3 of the coupler 3 protrudes from the front end T2 of the taper nut 2, the screw hole H3 of the protruding portion from the taper nut 2 of the coupler 3 may be adhesively closed with a cloth, tape, or the like.

  Therefore, when it is necessary to add to the constructed concrete prestressed building, the filling mortar of the concrete notch 11A is removed, and the protective material such as the cloth and adhesive tape on the front surface of the PC steel bar fixing part is peeled off. Since the inner peripheral thread surface S3 'can be used, the thread surface S6 at the base end of the new PC steel rod 6 for extension can be screwed and fixed to the front half of the coupler 3, so that the extension of the PC steel rod 6 can be performed. Placement becomes possible, and extension of prestressed building can be rationalized.

In the present invention, as shown in FIG. 1, a conical cylindrical sleeve pipe 14 having mounting pieces 14B at the front and rear ends is employed as a pocket former, and the mounting piece 14B at the front end is used as a baffle 13B. It is preferable to attach the mounting piece 14B at the rear end to the front surface of the bearing plate 1A on the circular plywood 13A temporarily fixed to the inner surface of the bearing plate.
In this case, as shown in FIG. 1B, the sleeve pipe 14 is provided with a conical cylinder 14A that expands in the forward direction, and a mounting piece 14B having a nail hole nh in the form of an angle is provided at a suitable position on the front end. A mounting piece 14B having a bolt hole bh in the form of an angle may be attached in a projecting form outward from 14A in a projecting form inward from the conical cylinder 14A.

  The front end mounting piece 14B of the sleeve pipe 14 is attached to a circular plywood 13A having a tapered surface t13 and a diameter (standard: 160 mm) larger than the front end diameter h14 (standard: 130 mm) of the conical cylinder 14A. The mounting piece 14B at the rear end is fastened with a bolt b13 to the bolt hole bh disposed on the front surface of the bearing plate 1A and the circular plywood 13A is attached to the board 13B side. It is only necessary to fasten with a nail n13.

Then, after the cast concrete is hardened, the plywood 13B is peeled off to remove the circular plywood 13A from the nail n13, the bolt b13 can be removed, and the sleeve pipe 14 can be easily removed because the diameter of the sleeve pipe 14 is increased forward. I can remove it.
Of course, if necessary, only the weir plate 13B and the circular plywood 13A may be removed, and the sleeve pipe 14 may not be removed.
Therefore, the concrete notch 11A on the front surface of the fixing body 1 can be easily formed under the concrete embedding form of the bearing plate 1A, and the concrete notch 11A having an expanding step that can be formed by the circular plywood 13A is restored and repaired. It is possible to finish the mortar filling smoothly and cleanly.

  Further, as shown in FIG. 2B, the fixing tool used for carrying out the method invention is a fixing tool D including a fixing body 1, a taper nut 2, and a coupler 3, and the fixing body 1 is shown in FIG. As shown in (D), the bearing plate 1A is gently bent backward in the vertical form of the front end, and the cylindrical portion 1T has a reduced diameter shape continuing from the bearing plate 1A to the rear, and the shrinkage is penetrated from the front end to the rear end. As shown in FIG. 6D, the taper nut 2 includes a screw hole H2 whose inner peripheral surface is a screw surface S2, and the outer peripheral surface is an insertion hole H1 for the fixing body 1. A conical cylinder 2T with a reduced diameter fitted to the front end of the conical cylinder 2T is provided with a square nut 2C at the front end, and the coupler 3 is screwed into the screw hole H2 of the taper nut 2 and screwed as shown in FIG. The screw hole S3 that is the screw surface S3 to be mated and whose inner periphery is screwed with the tip screw surface S6 of the PC steel rod 6 Etaneji is a pipe 3T.

In this case, the fixing body 1 is made of cast iron that satisfies the standard of JIS G5502 spheroidal lead cast iron. Typically, the bearing plate 1A is a square having a length of 125 mm on one side and is bent backward, A cylindrical portion 1T having a reduced diameter with a thickness T1 of 10 mm is provided with an insertion hole H1 for seating the taper nut 2.
The taper nut 2 is a cast steel product that satisfies the requirements of JIS G5111 structural high-tensile carbon steel and low alloy steel cast steel product, and the conical cylinder 2T is seated in the insertion hole H1 of the fixing body 1, The circumferential thread surface S2 is screwed with the coupler 3.
The coupler 3 is a carbon steel for machine structure of JISG4051. Typically, the coupler 3 is a thread surface S3 having a wall thickness t3 of 12.5 mm, an outer diameter d3 of 52 mm, and an inner diameter d3 ′ of 27 mm. It is a cylindrical body provided with '.

  Therefore, if the fixing tool of the present invention is employed, the fixing body 1 can be embedded in the concrete housing only by applying a pocket former to the front surface of the bearing plate 1A of the fixing body 1, and the bearing plate 1A that is gently bent backward is provided. As shown in FIG. 4B, the fracture surface is lengthened by the convergence of the tensile stress F to the rear, so that strong supporting force is exhibited, and most of the peripheral portion of the bearing plate 1A is held in the concrete C0. As a result, the holding force of the fixing body 1 in the concrete C0 increases, and the upper concrete covering thickness Sy can be reduced.

Further, since the fixing tool 1 can fix the PC steel rod 6 in a form in which neither the taper nut 2 nor the coupler 3 protrudes at the front portion of the bearing plate 1A, the concrete covering thickness Sx in front of the bearing plate 1A is determined by the bearing plate. The cover thickness is only 1A (specified thickness 30 mm + allowance thickness 10 mm), and the front concrete cover thickness Sx can be reduced.
Therefore, the PC steel rod 6 can be fixed by the fixing body 1 which is much smaller and lighter than the conventional concrete notch 11A, which is much smaller than the conventional concrete notch.
Therefore, the method invention of claim 1 of the present application can be suitably implemented.
In addition, the coupler 3 can fix the PC steel rod 6 by fixing the PC steel rod 6 by screwing and holding the PC steel rod 6 in the latter half and screwing the joint bolt 16B of the tensioning device in the front half. The first half of the later coupler 3 can be used to secure the screwing of the fixed end of the PC steel bar 6 again when the concrete prestressed building is renovated.

Further, in the invention of the fixing device, the fixing body 1 is such that the pressure bearing plate 1A is a square plate body, and is bent rearward with a radius of curvature of 200 to 250 mm, and the cylindrical portion 1T has an intermediate outer periphery in the longitudinal direction. It is preferable that the insertion hole H1 is communicated with a short fitting hole H1 ′ whose diameter expands to the rear end via the widened stepped portion 1G at the rear portion. .
In this case, if the radius of curvature of the bearing plate 1A is made too small, the stress fracture surface approaches horizontal and the degree of compressive stress increases, but the compression region becomes small and the compressive force of the surrounding concrete cannot be used.
Therefore, 200 to 250 mm is realistic, and typically 200 mm.
Further, since the protrusion 1C is intended to increase the strength of the fixing body cylindrical portion 1T and increase the adhesion of the concrete to the cylindrical portion 1T, it should be a semicircular protrusion having a height hc of about 10 mm (standard: 9 mm). It ’s fine.
The fitting hole H1 ′ is for inserting and fitting the tip of the trumpet sheath 4, and the step portion 1G is for providing a stopper function to the tip of the trumpet sheath 4. The fitting hole H1 ′ has a length L1 ′. Is 12 mm and the gradient height is 1.5 mm, and the stepped portion 1G may be cut and formed in a steeply inclined form.

Accordingly, in the fixing body 1, the support plate 1A has a radius of curvature of 200 to 250 mm and bends appropriately to the rear, so that the supporting force against the tension of the PC steel rod 6 increases and the protrusion 1C on the outer periphery of the cylindrical portion 1T. However, since the concrete adhesion strength is increased, the size can be reduced.
The cylindrical portion 1T is provided with a fitting hole H1 ′ having an enlarged diameter through the step portion 1G at the rear end, so that the front end of the trumpet sheath 4 can be smoothly inserted into the rear end of the cylindrical portion 1T. In order to prevent the pouring concrete from entering into the trumpet sheath 4, it is only necessary to wrap the adhesive tape 12 over the rear end of the cylindrical portion 1 </ b> T and the trumpet sheath 4. Work becomes easy.

  Further, in the invention of the fixing tool, the taper nut 2 is configured such that the rear surface B2 of the minimum outer diameter db of the conical cylinder 2T is the insertion hole H1 of the fixing body 1 when seated in the insertion hole H1 of the fixing body 1. The front surface T2 occupies a position inward of the front surface 1F of the bearing plate 1A, and the opposing corner angle dc of the square nut 2C is smaller than the maximum outer diameter dt of the front end of the conical cylinder 2T. Is preferred.

The taper nut 2 is seated in the insertion hole H1 of the fixing member 1 by screwing and holding the coupler 3 to which the PC steel rod 6 is screwed when the fixing member 1 is set. At the same time, it moves forward in the insertion hole H1 and again occupies the same seating position of the insertion hole H1 when the tension of the PC steel rod 6 is fixed, and moves back and forth in the insertion hole H1 of the fixing body 1 To do.
The trumpet sheath 4 is inserted and fitted into the fitting hole H1 ′ from the rear end of the fixing member cylindrical portion 1T when set in the concrete mold.

Accordingly, if the structure is such that the rear end of the minimum diameter of the taper nut 2 does not interfere with the stepped portion 1G of the fixing member inserting hole H1, that is, the front portion of the stepped portion 1G, the inside of the hole H1 for inserting the tapered nut 2 The movement at is not likely to interfere with the front end of the trumpet sheath 4 and can be seated smoothly at a predetermined position.
If the opposing corner diameter dc (standard: 67 mm) of the square nut 2C is smaller than the outer diameter dt (standard: 75.6 mm) of the front end of the conical cylinder 2T, the opposing side diameter Lc (standard) of the square nut 2C : 58 mm) provides a fixing space between the fixing member insertion hole H1 and a rotary fastener (typically a ratchet wrench) of the square nut 2C is provided on the front surface of the bearing plate 1A of the fixing member 1. The taper nut 2 can be tightened even at the position where it enters from 1F, and the fixing tool D becomes a set metal fitting at the position where the taper nut 2 enters from the front surface 1F of the fixing body 1, so that the fixing tool D can be shortened. The concrete covering thickness Sx on the front surface of the fixing body 1 can be shortened.

In the invention of the fixing tool, the length L3 of the coupler 3 is at least twice the limit fitting length of the PC steel rod 6, and the front surface T3 is fixed when the PC steel rod 6 is fixed. It preferably occupies an inward position from the front surface 1F of the fixing body 1 and is provided with a bolt insertion hole H3 ′ for screwing the bolt 3B at the center in the length direction.
Therefore, even if the coupler 3 is screwed into the screw hole H3 with the PC steel rod 6 from the rear and the joint bolt 16B of the tensioning device from the front and is pulled with the tensioning device, the thread surface breaks. Tension fixing can be performed without any problem, and the front end T3 of the coupler 3 can be fixed at an inner position from the front surface 1F of the fixing body.

In addition, since the screw hole H3 is provided at the center of the coupler 3, the position of the screwing tip of the PC steel rod 6 can be regulated by screwing the partition bolt 3B into the bolt insertion hole H3 ′. The hole H3 can secure a space of a required length forward from the bolt 3B, and guarantees the screwing of the joint bolt 16B of the tensioning device and the screwing and fixing of the new PC steel rod 6 at the time of building extension.
Since the front end T3 of the coupler occupies an inner position from the front surface 1F of the bearing plate when the PC steel bar 6 is fixed, the protection of the inner peripheral thread surface S3 'of the coupler 3 necessary for building extension from the filling mortar is also possible. It can be easily achieved with tape.

In addition, as shown in FIG. 1 (B), the pocket former used in the implementation of the method invention of the present application has a plurality of mounting pieces 14B for mounting on the shank 13B at the front end of the truncated cone body 14A at the rear end. The sleeve pipe 14 having a plurality of mounting pieces 14B for mounting on the pressure bearing plate 1A of the fixing body 1 is preferable.
In this case, the mounting piece at the front end protrudes outward in the form of an angle to form a nail hole nh, the mounting piece 14B at the rear end protrudes inward to form a bolt hole bh, and the corresponding position of the bearing plate 1A In addition, a bolt hole bh may be arranged.

Then, as shown in FIG. 1A, the sleeve pipe 14 has the front end mounting piece 14B attached to the circular plywood 13A with the nail n13, and the circular plywood 13A is fixed to the circular plywood 13B from the bail plate 13B side with the nail n13. The mounting piece 14B is attached to the bearing plate 1A with bolts b13, and after setting the cast concrete, the plywood 13B is peeled off to remove the circular plywood 13A. 14 can be removed.
Therefore, a desired concrete notch 11A can be formed by simple attachment and removal of the sleeve pipe 14, and the circular plywood 13A having a circumferential surface with a taper t13, and repair can be performed by using the circular plywood 13A. It is possible to form a concrete notch 11A that is finished with a beautiful restoration.

  According to the method invention of the present application, the fixing body 1 is a vertical bearing plate 1A and a cylindrical portion 1T extending rearward, and one PC steel rod 6 is connected to the bearing plate 1A via the coupler 3 and the taper nut 2. In order to fix by inserting into the insertion hole H1 in the center portion, the front face 1F of the bearing plate 1A has a flat shape, and a concrete notch formation method using a pocket former, which was conventionally applicable only by the unbond method, is a grout bond method ( It can also be applied to the after-bond method, and can be fixed in a space-saving concrete notch 11A by a pocket former.

  And since the bearing plate 1A is embedded in the concrete C0 together with the cylindrical portion 1T, the adhesion supporting force of the concrete C0 to the fixing body 1 is increased, and the dimension between the bearing plate 1A and the floor slab surface Sf, that is, the floor slab concrete. Since the cover thickness Sy of C0 can be reduced and the tension of the PC steel rod 6 can be fixed in a form that does not protrude from the front surface 1F of the bearing plate 1A, the covering thickness Sx of the concrete C0 on the front surface of the bearing plate 1A, that is, the concrete notch 11A The depth Sx can also be reduced, which is advantageous in terms of the design surface of the prestressed concrete building and the repairing original surface of the concrete notch 11A.

  That is, the fixing body 1 can be integrated into the concrete, and most of the outer periphery of the vertical bearing plate 1A is embedded in the cast concrete C0. Therefore, the bearing plate 1A has the concrete zone Zf on the front side and the rear side. Since the concrete notch 11A is far smaller than the conventional concrete notch for holding the bearing plate, the concrete notch 11A can be made smaller. The repair work of the concrete notch 11A after fixing the PC steel bar is also simplified.

Therefore, the present invention can be applied to the horizontal part and the vertical part of the concrete outer wall, and can be applied between columns having a large amount of reinforcing bars with good workability.
Further, the means for preventing the inflow of the cast concrete into the trumpet sheath 4 is also a simple and easy operation in which the adhesive tape 12 is simply wound around the rear end of the fixing member cylindrical portion 1T and the trumpet sheath. Become.

Further, the tension work of the PC steel bar 6 is carried out by using a tension device (torque wrench) provided with a joint bolt 16B having the same diameter as the PC steel bar 6 and screwing the joint bolt 16B into the coupler 3. This can be carried out without imposing a burden on the pressure bearing plate 1A of the fixing body, and in the fixing work of the PC steel bar 6, the extra length cutting work of the PC steel bar 6 becomes unnecessary.
In addition, the front half of the coupler 3 to which the joint bolt 16B of the tensioning device is screwed and locked can be used for fixing the base end of the PC steel bar 6 on the newly added side when the concrete prestressed building is expanded. Extension construction becomes possible.

In addition, the fixing device D used for carrying out the invention of claim 1 can be embedded in the concrete frame C0 by simply applying a pocket former to the front surface of the pressure-bearing plate 1A of the fixing unit 1, and can be embedded in the concrete frame C0. For the pressure plate 1A, the fracture surface is elongated due to the backward convergence of the tensile stress acting line F to cause the bearing plate 1A to exert a strong holding force, and most of the periphery of the bearing plate 1A is in the concrete C0. Because it is embedded, the upper concrete covering thickness Sy and the forward concrete covering thickness Sx of the fixing body can be reduced, and the PC steel rod 6 can be fixed by the fixing body 1 which is much smaller and lighter than before. It becomes.
Therefore, the method invention of claim 1 of the present application can be suitably implemented.

  In addition, since the coupler 3 can hold the PC steel rod 6 in the latter half and screw the joint bolt 16B of the tensioning device in the first half to fix the tension of the PC steel rod 6, the PC steel 6 In the first half of the coupler 3 after fixing, the screw hole H3 is in a hollow state, and when an extension request is generated during the durability of the concrete prestressed building, the grout mortar filled in the concrete notch 11A is removed, The extension work can be rationally carried out by screwing the fixed end of the PC steel rod 6 into the hollow state screw hole H3 of the first half of the coupler 3 again.

Further, if the first pocket former shown in FIG. 1B, that is, the sleeve pipe 14 is applied to the implementation of the method of the present invention, the mounting piece 14B at the tip is nailed to the dam 13B via the circular plywood 13A. Then, by attaching the mounting piece 14B at the rear end to the front surface of the pressure bearing plate 1A with the bolt b13, the pocket former can be easily arranged between the fixing body 1 and the dam plate (formwork) 13B. It is also easy to remove the sleeve pipe 14 when dismantling the formwork after the concrete is hardened.
Therefore, by simply attaching and removing the sleeve pipe 14 and using the circular plywood 13A, a concrete notch 11A having a desired size and a finished repair source by filling mortar can be formed, and the method invention of the present application can be formed. Can be suitably implemented.

Hereinafter, the present invention will be described based on an example in which a PC steel rod 6 having a diameter of 26 mm of JISG 3109 is inserted through a spiral sheath 5 and a trumpet sheath 4 having an outer diameter of 40 mm.
The PC steel bar 6 is provided with a threaded surface S6 at the fixed end and the tension end. The PC steel bar 6 is fixed at the fixed end side by the fixing tool D, and the tension end is fixed by tension within the fixing tool D. As shown in FIG. 2 (B), the fixing device D includes a fixing member 1, a taper nut 2 seated in the fixing member, and an end thread surface S6 of the PC steel rod 6, which are screwed and locked. The coupler 3 is coupled to the taper nut 2.

[Fixing body (Fig. 5)]
5A is an overall perspective view from the front of the fixing body 1, FIG. 5B is an overall side view of the fixing body 1, FIG. 5C is a front view of the fixing body 1, and FIG. FIG. 6D is a longitudinal sectional view of the fixing body 1 taken along the line D-D in FIG.
The fixing body 1 is composed of a vertical bearing plate 1A on the front surface and a cylindrical portion 1T having a reduced diameter extending rearward from the center portion of the bearing plate 1A. From the center portion of the bearing plate 1A, a cylindrical portion 1T is formed. A taper nut seating insertion hole H1 that penetrates to the rear part is provided, and a rear end of the insertion hole H1 is provided with a short fitting hole H1 ′ for fitting a trumpet sheath. ), The diameter of the fitting hole H1 ′ is gradually increased from the rear end of the insertion hole H1 through the rapidly expanding step portion 1G.

The fixing body 1 is made of cast iron that satisfies the standard of spherical leaded cast iron products of JISG5502. The bearing plate 1A has a thickness of 12 mm, and as shown in FIG. 5C, the length La of one side is 125 mm. As shown in FIG. 5 (A), this is a square plate that is provided with bolt holes bh for attaching a pocket former at the four corners and is bent backward with a radius of curvature of 200 mm.
As shown in FIG. 5D, the conical cylindrical portion 1T that continues in a reduced diameter form from the rear surface of the bearing plate 1A to the rear has a wall thickness t1 of 10 mm, and is arranged on the outer periphery of the central portion in the longitudinal direction of the cylindrical portion 1T. Is provided with an annular rib-shaped conical protrusion 1C having a height hc of 9 mm, and the entire length L1 of the fixing body 1 is 87.7 mm.

  Further, as shown in FIG. 5D, the fixing member 1 has an insertion hole H1 and a fitting hole H1 ′ from the center of the front end 1F of the bearing plate 1A to the center of the rear surface B1 of the cylindrical portion 1T. The insertion hole H1 for seating the taper nut has a length L2 from the front surface 1F of the bearing plate to the rear step portion 1G of 72.7 mm, and the rear end from the front end diameter (R1) 83 mm. The diameter (R2) of the step portion 1G is reduced to 58 mm, and at the rear end of the insertion hole H1, a distance L1 from the rear end of the step portion 1G having a length of 3 mm to the cylindrical portion 1T rear surface B1 is expanded. The fitting hole H1 ', in which the diameter of' is 12 mm, the starting end diameter R3 is 62 mm, and the rear end diameter R4 is 65 mm, is gradually expanded.

[Taper nut (Fig. 6)]
The taper nut 2 is a member that holds the coupler 3 in the central through screw hole H2 and is seated in the conical insertion hole H1 of the fixing body 1 on the outer peripheral surface of the conical cylinder 2T. ) Is an overall perspective view, FIG. 6B is a front view, FIG. 6C is a side view, and FIG. 6D is a longitudinal side view.
The taper nut 2 is a cast steel product that satisfies the structural high-strength carbon steel or low alloy steel cast steel product of JISG5111, and the overall shape of the taper nut is as shown in FIG. A conical cylinder 2T having a truncated cone shape whose diameter is reduced from the front surface 2F to the rear surface B2 is provided with a hexagonal nut 2C protruding forward from the front surface 2F, and penetrates the nut 2C and the conical cylinder 2T in the center. The screw hole H2 is provided.
The thickness Ln of the nut 2C is 10 mm, the length L2 ′ of the conical cylinder 2T is 51 mm, and the total length L2 of the tapered nut 2 is 61 mm.
Further, the hexagonal nut 2C has a diagonal corner distance dc of 67 mm and an opposed side diameter Lc of 58 mm. The conical cylinder 2T has a front surface 2F of a diameter dt of 75.6 mm and a rear surface B2 of a diameter db of 58 mm. A screw hole H2 having a diameter ds of 52 mm passes through the center of the taper nut 2.

[Coupler (Fig. 7)]
The coupler 3 is a member for screwing and housing the end portion of the PC steel rod 6 having the screw surface S6 into the screw hole H3 and screwing into the screw hole H2 of the taper nut 2 at the outer screw surface S3. 7A is an overall perspective view, FIG. 7B is a front view, FIG. 7C is a side view, and FIG. 7D is a longitudinal sectional view taken along line DD in FIG. 7A. .
As shown in FIG. 7A, the overall shape of the coupler 3 is a threaded pipe 3T having a threaded surface on both the outer peripheral surface and the inner peripheral surface, and is a threaded pipe made of carbon steel for machine structure of JISG4051. A screw hole H3 having a diameter of 85 mm, an outer diameter d3 of 52 mm, a wall thickness t3 of 12.5 mm, and an inner diameter (d3 ′) of 27 mm passes through the center.
Then, at the center in the length direction, as shown in FIG. 7B, a hole for inserting a partition bolt (partition hole) H3 ′ is drilled from the outer peripheral thread surface S3 into the screw hole H3.

[Sleeve pipe (Fig. 1 (B))]
The sleeve pipe 14 is a mold material that is placed on the front surface of the fixing body 1 when setting the concrete mold, and is a pocket former that forms a concrete notch 11A for tension fixing work of the PC steel rod 6 on the front surface of the fixing body 1. is there.
FIG. 1B is an exploded perspective view of the sleeve pipe 14 and a circular plywood attached to the front surface of the sleeve pipe 14.
The sleeve pipe 14 is a steel plate molded body having a general wall thickness of 2.3 mm. As shown in FIG. 1B, the conical cylinder 14A has a front end diameter h14 of 130 mm, a rear end diameter h14 ′ of 120 mm, and a length L14 of 28 mm. is there.

At the front end, four angle-shaped mounting pieces 14B are provided at equal intervals with a square shape with a side of 15 mm and a nail hole nh at the center, and the rear end is erected inward. Four angle-shaped mounting pieces 14B having bolt holes bh at the center are provided at equal intervals.
Further, the circular plywood 13A has a thickness of 12 mm, an outer surface diameter (d13) of 160 mm, and a peripheral side surface that is reduced in diameter by a taper t13 from the outer surface side to the inner surface side. It is something to fix.

[Construction (Fig. 1, Fig. 2)]
FIG. 1A is a mold setting state diagram on the tension end side of the PC steel rod, and FIG. 2A is a mold setting state diagram on the fixed end side of the PC steel rod.
As shown in FIG. 1 (A), the PC steel bar 6 is prepared by calculating the amount of elongation in advance, and the thread surface S6 at the tip of the coupler 3 is connected to the coupler 3 with the conventional spiral sheath 5 and trumpet sheath 4 penetrating. Screw in the second half.
In this case, the partition bolt 3B is screwed into the bolt insertion hole H3 ′ at the center in the longitudinal direction of the coupler 3 so as to protrude into the screw hole H3, and the screwing position of the PC steel rod 6 into the coupler 3 is set. Stipulate.

  Then, as shown in FIG. 1A, a taper nut 2 is screwed onto the outer peripheral thread surface S3 of the coupler 3, and the taper nut 2 is temporarily fixed via a reinforcing bar in a concrete mold. The mounting piece 14B is aligned with the bolt hole bh of the pressure bearing plate 1A on the front surface of the fixing body 1, and the sleeve pipe 14 is fixedly attached with the bolt b13. The nail n13 is driven through the circular plywood 13A from the nail hole nh of the piece 14B, and the circular plywood 13A is fastened by the nail n13 from the outside of the concrete piling plate 13B.

  Further, the tip of the conventional trumpet sheath 4 fitted to the tip of the conventional spiral sheath 5 is fitted into the fitting hole H1 ′ at the rear end of the cylindrical portion 1T of the fixing body 1 in a contact form with the stepped portion 1G. 1A, the adhesive tape 12 is wound around the tip of the trumpet sheath 4 and the rear end of the cylindrical portion 1T, and the adhesive tape 12 is also applied to the fitting portion between the trumpet sheath 4 and the spiral sheath 5. Wrap.

On the PC steel rod fixing side, as shown in FIG. 2 (A), the fixing body 1 is temporarily fixed to the reinforcing bars in the mold, and the conventional separators 17A, P-con 17C, and foam ties 17B are used as the tie. In the fixing body 1, the base end of the PC steel rod 6 is screwed and fixed into the coupler 3 with the threaded surface S 6 in the fixing body 1 in the same manner as the tension end side. The taper nut 2 is seated and held in the fixing body 1 by being screwed into the fixing body 1.
Further, the adhesive tape 12 is also wound around the fitting portion between the spiral sheath 5 and the trumpet sheath 4 and the fitting portion between the trumpet sheath 4 and the fixing member cylindrical portion 1T to prevent intrusion of the cast concrete.
Then, concrete is placed in the concrete formwork, and when the concrete is hardened, the formwork is disassembled.

FIG. 4A is an explanatory view of tension fixation of the PC steel bar 6.
That is, the joint bolt 16B is threaded and fastened through the ratchet wrench into the fastening screw hole H3 in the front half of the coupler 3, and the rotary output shaft 15 of the torque wrench is inserted into the joint tool square hole H16 to be rotated. For example, the coupler 3 and the PC steel bar 6 are pulled forward, the PC steel bar 6 is tensioned, and the predetermined tension value of the PC steel bar is confirmed by checking the elongation amount calculated in advance or the tension load of the torque wrench gauge. The operation of the wrench is stopped, the nut 2C of the taper nut 2 is rotated by the ratchet wrench, the taper nut 2 is tightened, and is seated in the insertion hole H1 of the fixing tool 1.
Next, the insertion hole H1 of the bearing plate 1A is closed with a waterproof sheet or tape, the concrete notch 11A on the front surface of the fixing body 1 is filled with the non-shrinking mortar 11B, and the grout inlet 4A is connected from the grout hose 4B. Then, the grout mortar 7 is filled in the gap between the spiral sheath 5 and the trumpet sheath 4 and the PC steel rod 6.

FIG. 3 is an explanatory view of the after-bond fixing state of the obtained PC steel bar 6.
As shown in FIG. 3, the fixing body 1 is reinforced and held by a conventional spiral muscle 8, the concrete notch 11 </ b> A is repaired by a non-shrink mortar 11 </ b> B, and the trumpet sheath 4 and the spiral sheath 5 are grouted. An afterbond PC steel rod fixing structure filled with mortar 7 was obtained.
Even if the PC steel bar 6 is on the tension end side P or the fixed end side L, there is no protrusion from the front surface 1F of the fixing body 1, so the concrete covering thickness Sx is 40 mm (design limit). Value 30 mm + margin 10 mm).

Further, since the outer peripheral portion of the fixing body support plate 1A on the tension end side P is embedded in the concrete C0, the holding force increases between the front concrete zone Zf and the rear concrete zone Zb of the support plate 1A. As shown in FIG. 4B, the concrete covering from the floor slab surface Sf on the upper surface of the fixing body 1 is increased by increasing the concrete holding force due to the rearward inclination of the fracture surface as shown in FIG. The thickness Sy was as small as 40 mm (design limit value 30 mm + margin 10 mm) together with the covering thickness Sy on the fixed end side L.
In addition, the restoration repair with the non-shrink mortar 11B with respect to the concrete notch 11A on the tension end side P is also finished cleanly with an increase in the fixing force due to the presence of the enlarged region Z13 due to the circular plywood 13A attached to the sleeve pipe 14. It was.

It is explanatory drawing of a type | mold set, Comprising: (A) is sectional drawing by the side of a tension | tensile_strength side, (B) is an exploded perspective view of a pocket former. It is explanatory drawing of a type | mold set, Comprising: (A) is sectional drawing by the side of a fixed end, (B) is a disassembled perspective view of a fixing tool. It is whole explanatory drawing of the state which carried out tension fixation construction of PC steel bar. It is explanatory drawing by the side of a tension | tensile_end, Comprising: (A) is sectional drawing of a tension construction state, (B) is stress action explanatory drawing of a PC steel bar. It is explanatory drawing of a fixing state, (A) is a whole perspective view, (B) is a side view, (C) is a front view, (D) is the DD sectional view taken on the line of (A). It is explanatory drawing of a taper nut, Comprising: (A) is a whole perspective view, (B) is a front view, (C) is a side view, (D) is the DD sectional view taken on the line of (A). It is explanatory drawing of a coupler, (A) is a whole perspective view, (B) is a front view, (C) is a side view, (D) is the DD sectional view taken on the line of (A). It is explanatory drawing of a prior art example, (A) is a perspective view of a fixing structure, (B) is sectional drawing of a construction state.

Explanation of symbols

1 Fixing body 1A Pressure bearing plate 1C Rib-shaped protrusion (protrusion)
1F, 2F Front 1G Stepped portion 1T Cylindrical portion 2 Taper nut 2C Nut (hexagon nut)
2T conical cylinder (cylindrical)
3 Coupler 3B bolt (partition bolt)
3T Threaded pipe 4 Trumpet sheath 4A Grout inlet 4B Grout hose 5 Spiral sheath 6 PC steel bar 7 Grout mortar 8 Spiral muscle 11A Concrete notch (notch)
11B Non-shrink mortar 12 Adhesive tape (vinyl tape)
13A Circular plywood 13B Shear board (template)
14 Sleeve pipe (Pocket former)
14A Conical cylinder 14B Mounting piece 15 Rotation output angular shaft 16 Joint member 16B Joint bolt (screw bolt, bolt shaft)
17A Separator 17B Foam tie 17C P-con B1, B2 Rear surface b13 Bolt bh Bolt hole C0 Concrete (cast concrete, concrete frame)
D Fixing tool H1 Insertion hole H1 'Fitting hole H2, H3 Screw hole H3' Bolt insertion hole n13 Nail nh Nail hole S2, S3, S3 ', S6 Thread surface Sf Floor slab surface T2, T3 Front end (front surface)
Z13 Expansion zone Zb Rear concrete zone Zf Front concrete zone

Claims (12)

  A fixing body (1) including a pressure bearing plate (1A) whose front end is vertical and a cylindrical portion (1T) having a reduced diameter that continues horizontally from the pressure bearing plate (1A) is disposed in a concrete formwork. The trumpet sheath (4) is fitted to the rear end of the cylindrical portion (1T), and the screw surface (S6) at the tip of the PC steel rod (6) passing through the spiral sheath (5) and the trumpet sheath (4) is provided. The inner periphery and the outer periphery of the coupler (3) are screwed and fixed to the rear half of the coupler (3), and the coupler (3) is screwed onto the inner peripheral thread surface (S2) of the taper nut (2). ) Is fixed to the fixing body (1), the pocket former (14) is arranged on the front surface of the pressure-bearing plate (1A) of the fixing body (1), the concrete mold is set, and the concrete mold is formed after the concrete is placed and hardened. The concrete which was dismantled and formed on the front of the bearing plate (1A) The screw bolt (16B) of the coupling member (16) of the tensioning device is screwed into the front half of the coupler (3) through the screw (11A), and the PC steel rod (6) is connected to the coupler (3) and the taper nut ( 2) A PC steel rod fixing method in the afterbonding method in which the taper nut (2) is tightened and seated in the insertion hole (H1) of the fixing body (1) when it is pulled out together with a predetermined tension value.   The insertion hole (H1) of the fixing body (1) is provided with a small fitting hole (H1 ') whose diameter is expanded to the rear end via the enlarged diameter step (1G), and the trumpet sheath (4) The PC steel rod fixing method according to claim 1, wherein the front end is inserted into the fitting hole (H1 ′) up to the step (1G).   The coupler (3) has a bolt insertion hole (H3 ′) in the center in the length direction, and a partition bolt (3B) is screwed into the bolt insertion hole (H3 ′) to position the tip of the PC steel rod (6). Is defined by a bolt (3B), the PC steel bar fixing method according to claim 1 or 2.   The pressure-bearing plate (1A) of the fixing body (1) is a rectangular plate shape, bends backward, and includes a rib-like protrusion (1C) on the outer periphery in the middle in the longitudinal direction of the cylindrical portion (1T). The PC steel bar fixing method according to any one of 1 to 3.   The taper nut (2) has the front end (T2) installed inward from the front surface (1F) of the fixing body, and the elongation amount of the PC steel rod (6) is calculated in advance. The PC steel rod fixing method according to any one of claims 1 to 4, wherein the front end (T3) of the coupler (3) is fixed inward from the front surface (1F) of the fixing body.   After fixing the PC steel rod (6), after protecting the inner circumferential thread surface (S3 ') of the coupler, the non-shrink mortar (11B) is filled into the concrete notch (11A). The fixing method of the PC steel bar according to the item.   As the pocket former, a conical cylinder sleeve pipe (14) having mounting pieces (14B) at the front and rear ends is adopted, and the front mounting piece (14B) is temporarily fixed to the inner surface of the dam plate (13B). The PC steel rod fixing method according to any one of claims 1 to 6, wherein a rear end mounting piece (14B) is mounted on the front surface of the bearing plate (1A) on the circular plywood (13A).   A fixing device (D) including a fixing body (1), a taper nut (2), and a coupler (3) for use in carrying out the invention of claim 1, wherein the fixing body (1) has a front end. The pressure-reducing plate (1A) gently bent rearward in the vertical configuration and the cylindrical portion (1T) of the reduced-diameter configuration continuing rearward from the pressure-bearing plate (1A), and a reduced-diameter configuration penetrating from the front end to the rear end The taper nut (2) has a screw hole (H2) whose inner peripheral surface is a screw surface (S2), and the outer peripheral surface is an insertion hole (H1) for the fixing body (1). ) Is a conical cylinder (2T) having a reduced diameter and is fitted with a square nut (2C) at the front end of the conical cylinder (2T). The coupler (3) has a screw hole (2) with a tapered nut (2) on the outer periphery. H2) is a screw surface (S3) that is screwed with the screw hole (H3) whose inner periphery is screwed with the tip screw surface (S6) of the PC steel rod (6). Fixing device is a screw pipe (3T) having a).   In the fixing body (1), the pressure bearing plate (1A) is a square plate body, and is bent backward with a radius of curvature of 200 to 250 mm, and rib-shaped protrusions ( 1C), and the insertion hole (H1) communicates with a short fitting hole (H1 ′) whose diameter expands to the rear end through an expanded stepped portion (1G) at the rear portion. The fixing tool according to claim 8.   In the taper nut (2), when the fixing body (1) is seated in the insertion hole (H1), the rear surface (B2) of the minimum outer diameter (db) of the conical cylinder (2T) is inserted into the fixing body (1). Occupying a position where it does not interfere with the step (1G) of the hole (H1), the front face (T2) occupies an inner position from the front face (1F) of the bearing plate (1A), and the opposite corner of the square nut (2C) The fixing device according to claim 8 or 9, wherein the diameter (dc) is smaller than the maximum outer diameter (dt) of the front end of the conical cylinder (2T).   The coupler (3) has a length (L3) which is at least twice the limit fitting length of the PC steel rod (6), and the front surface (T3) is the fixing body when the PC steel rod (6) is fixed. 9. It occupies an inward position from the front surface (1F) of (1), and has a bolt insertion hole (H3 ′) for screwing a bolt (3B) at the center in the length direction. Or 9 or 10 fixing device.   A pocket former used in the implementation of the invention of claim 1, wherein a plurality of mounting pieces (14 B) for mounting to a slat (13 B) are attached to the front end of the truncated cone body (14 A) at the rear end. Is a sleeve pipe (14) provided with a plurality of mounting pieces (14B) for mounting on the pressure bearing plate (1A) of the fixing body (1).

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