JP3246015B2 - Fixing structure of PC steel - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an anchor for prestressed concrete (PC) steel.

[0002]

2. Description of the Related Art The structure of a conventional fixing device and a conventional joint will be described with reference to FIG. The one shown is a PC steel bar 1
The fixing tool is composed of a tapered nut 2 and an anchor croquette 3. The tapered nut 2 has a tapered seat surface 2a, which is screwed to the steel rod 1 to
At 2a, it comes into contact with the anchor croquette 3 and transmits the tension to its support plate 4. On the other hand, anchor croquet 3
An anchor ring 5 is joined to a support plate 4 having a through portion 8 of the steel bar 1 at the center, and the through portion 8 is formed with an inclination suitable for the tapered seat surface 2a. Then, the anchor ring 5 bears the splitting force acting on the concrete at the fixing portion due to the tension.

[0003] Here, the steel rod 1 is covered with a sheath 9 having a spiral concave portion 15 on the inner periphery in order to isolate it from concrete, and a Glocken joint 10 is used for joining the sheath 9 and the croquette 3. This is such that one end is screwed into the spiral recess 15 of the sheath, and the other end is an anchor croquette 3.
Is externally fitted to the through portion 8. Then, the threaded portion and the outer fitting portion are wound with an adhesive tape (not shown) to stop water. Reference numeral 21 denotes a montage top attached to the steel bar using the thin nut 20, which is used to easily form a concave portion for mounting a jack when being tensed. or,
Packing 23 between montage top 21 and support plate 4
Is inserted, and the taper nut 2 and the anchor croquette 3 are fixed with copper studs (not shown).

[0004]

As described above, in the anchoring portion using the croquette, since the anchoring ring bears the splitting force of the concrete, no special reinforcing bars or the like are required. The plate is a stamped product of a steel plate press and has a small opening area. For this reason, there is a problem that the concrete around the back surface of the support plate (the portion surrounded by the anchor ring, the support plate and the steel bar) is poor, air pockets are generated, and the entire fixing device sinks into the concrete at the time of tension and fixing.

[0005] In addition, since the glocken joint and the glocke are simply fitted and fixed with water with an adhesive tape, they may come off when a large external force is applied to the sheath before or during concrete placement. there were. In this case, since the concrete goes between the sheath and the steel bar, the necessary stress is not given to the concrete at the time of tension. Or, there was a problem that grout could not be injected and the steel rod corroded.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide a fixing structure which improves the concrete surrounding on the back surface of a support plate and ensures the joint between a croquette and a sheath. To provide.

In order to achieve the above object, the fixing structure of the present invention is characterized in that one end of a PC steel material is fixed by a nut fitted to a glocket and a PC steel material, and a sheath of the PC steel material and an anchor croquette are connected via a glocken joint. In the fixing structure, the croquette is formed by integrating a bearing plate having a penetrating portion into which a PC steel material is inserted and an anchor ring, and the bearing plate and the anchor ring are reinforced by ribs, and the bearing plate and the anchor ring And a gap of 25 mm or more, and one end of a Glocken joint is fitted into the penetrating portion of the Glocke, and is joined by engagement of a concave portion and a convex portion provided respectively. .

[0008]

An embodiment will be described below with reference to the drawings. FIG.
FIG. 2 is a schematic view showing the structure of the embodiment of the present invention on the tension side where a montage top 21 is attached using a thin nut 20.
In the figure, reference numeral 1 denotes a PC steel rod, which is fixed by using a taper nut 2 and an anchor croquette 3 attached to its end. The tapered nut 2 has a tapered seating surface 2a that can be screwed onto the PC steel rod 1, and the seating surface 2a abuts on a support plate 4 of a croquette described below to transmit tension.

The anchor croquette 3 is shown in FIGS.
As shown in the figure, the support plate 4 is made of cast iron integrated with the anchor ring 5 via three ribs 6 and has a through portion 8 into which the PC steel bar 1 is inserted at the center of the support plate 4. . Here, an opening 7 (2) is provided between the support plate 4 and the anchor ring 5.
5 × 120 mm × 3 places), and the concrete can be wrapped around the back surface of the support plate 4 from the opening 7. The gap L between the openings is preferably 25 mm or more in order to ensure the passage of the concrete aggregate.

On the other hand, the penetrating portion 8 is constituted by a mortar-shaped opening 8a that fits the seating surface 2a of the taper nut and a cylindrical portion 8b connected to the opening 8a. The rod sheath 9 is joined.

The glocken joint 10 is made of a thin steel plate or the like, and is often fitted to the cylindrical portion as shown in FIG. 1. However, the one used by inserting it into the cylindrical portion 8b of the glocke is shown in FIG. It will be described based on. FIG. 1A is a sectional view, and FIG.
Is a top view. As shown in the figure, the glocken joint is a tubular member having a connection portion 11 with a grout hose on a side portion, and has a role of a fastener so that it does not easily come off when inserted into the tubular portion 8b of the glocke at one end. A functioning convex part 12 is formed.

The projections 12 have a claw shape protruding in the joint radial direction, and two projections are provided in this embodiment. here,
(A) As shown in the figure, if it is tapered toward the joint opening, insertion into the tubular portion 8b can be facilitated. Furthermore, if notches 13 are formed on both sides of the protruding portion as shown in FIG. 6 (B), it can be slightly curved in the radial direction, and can be more easily inserted.

When the croquette 3 and the sheath 9 are joined using such a joint 10, as shown in FIG.
A croquette having an annular groove 14 with which the protrusion is engaged is formed on the inner peripheral surface of the cylindrical portion. Glocken joint on cylindrical part 8b
When 10 is inserted, the convex portion 12 is pressed by the inner surface of the cylindrical portion and bends toward the inside of the joint, and when it is inserted further deeply, the convex portion 12 reaches the groove 14 of the cylindrical portion 8b and returns elastically to the groove. Will engage. As a result, the protrusions 12 serve as resistance to the joint falling off, and reliable joining can be performed.

On the other hand, the other end of the glocken joint 10 and the sheath 9 are joined by screwing, as in the prior art.
That is, a spiral concave portion 15 is formed on the inner periphery of the sheath, and a spiral ridge 16 screwed with the spiral concave portion 15 is formed on the outer surface of the other end of the glocken joint.
Is formed, the ends of the sheath 9 can be joined by screwing the end of the sheath 9 into the glocken joint 10. Then, as shown in FIG. 1, if the adhesive tape 17 is wrapped around the joint between the glocken 3 and the glocken joint 10 and the joint between the glocken joint and the sheath, it is possible to ensure the water stoppage. In addition, as shown in FIG.
If an annular stopper 24 is provided below the 12 and an O-ring is interposed therebetween, the O-ring can be compressed and water-stopped between the opening edge of the anchor croquet tubular portion 8b and the stopper 24, and an adhesive tape Does not require water stoppage.

By the way, when grout is injected into the sheath 9, the grout rises from the side of the joint with the sheath 9 (the spiral ridge side) and reaches the side of the joint with the croquette 3 (the convex side). At this time, it is confirmed that the grout is filled in the sheath 9 by discharging the grout from the end of the grout hose through the connection portion. Therefore, in order to prevent the occurrence of air pockets, it is preferable to provide the connection portion 11 of the grout hose on the side of the joint with the croquette 3 (projection side) as shown in FIG. The reason why the angle is provided to the spiral mountain side is to avoid contact with the anchor ring of the croquette. further,
Forming the unevenness 25 at the tip of the connecting portion 11 is effective in preventing the grout hose from coming off. Here, it is preferable to provide a rib 26 (for example, a triangular plate) to prevent the connection portion 11 of the grout hose from being broken by an unexpected external force at the time of construction.

In the above description, the case where two convex portions are provided has been described as an example. However, by increasing the number of the convex portions to three or four, etc., stronger bonding can be performed. In FIG. 1, reference numeral 18 denotes a copper stud for fixing the taper nut and the anchor croquette, 19 denotes a grout hose, and 22 denotes a mold.

[0017]

As described above, according to the fixing structure of the present invention, concrete can be surely wrapped around the back surface of the support plate. Therefore, it is possible to prevent the occurrence of air pockets, and to prevent the entire croquette from sinking into the concrete or tilting. Further, since the connection between the glocken joint and the glocke is performed firmly, it is possible to avoid fatal problems with the PC structure such as insufficient tension caused by disengagement of the joint and inability to inject grout.

[Brief description of the drawings]

FIG. 1 is a schematic view showing a fixing structure of the present invention.

FIG. 2 is a sectional view of the croquette of the present invention.

FIG. 3 is a perspective view showing a state where the croquette of the present invention is attached to a PC steel material.

FIG. 4 shows a glocken joint of the present invention.
(A) is a sectional view, and (B) is a top view.

FIG. 5 is a schematic view showing a conventional fixing structure.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 PC steel rod 2 Taper nut 2a Bearing surface 3 Anchor croquette 4 Support plate 5 Anchor ring 6 Rib 7 Opening 8 Through part 8a Opening 8b Cylindrical part 9 Sheath 10 Glocken joint 11 Connection part 12 Convex part 13 Notch part 14 Groove 15 Spiral recess 16 Spiral ridge 17 Adhesive tape 18 Copper stud 19 Grout hose 20 Thin nut 21 Montage top 22 Formwork 23 Packing 24 Stopper 25 Roughness 26 Rib L Gap

Claims (4)

(57) [Claims] 1. A fixing structure in which one end of a PC steel material is fixed with a nut fitted to an anchor croquette and a PC steel material, and a sheath of the PC steel material and an anchor croquette are joined via a glocken joint, wherein the croquette is A support plate having a penetrating portion into which a PC steel material is inserted and an anchor ring are integrated. The support plate and the anchor ring are reinforced by ribs, and a gap between the support plate and the anchor ring is 25 mm.
As described above, one end of a glocken joint is fitted into the penetrating portion of the glocke, and is joined by engagement of a concave portion and a convex portion provided respectively.
Fixing structure of C steel. 2. An anchor croquet in which a support plate having a through portion into which a PC steel material is inserted and an anchor ring are integrated, a glocken joint engages with the through portion.
A concave portion or a convex portion is formed, and the support plate and the anchor ring are reinforced by a rib, and a gap between the support plate and the anchor ring is reduced by two.
An anchor croquet, characterized in that the length is 5 mm or more. 3. A glocken joint for joining an anchor croquette and a sheath made of PC steel, wherein one end is provided with a projection or a depression which engages with a recess or a projection formed in a penetrating portion of the anchor croquette. Glocken joint characterized by the following. 4. The glocken joint according to claim 3 , wherein notches are provided on both sides of the convex portion or the concave portion.