JPH0431939Y2 - - Google Patents

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a bearing plate support recessed metal fitting for unbonded PC steel bars, and more specifically, to post-tension precast concrete (hereinafter referred to as PC
It relates to a bearing plate support recessed metal fitting used for a member in which an unbonded PC steel rod and its bearing plate are temporarily installed in a formwork and concrete is poured.

[Conventional technology]

Conventionally, for concrete products using unbonded PC steel bars, a bearing plate is attached to the formwork before concrete placement, as shown in Figures 2 and 3. FIG. 2 shows a structure in which a magnet 3 is attached to a recessed metal fitting 2 attached to a formwork 1, and a bearing plate 4 is attracted to this magnet 3. The structure shown in FIG. 3 has a support plate 4 attached to a fixing spring 7 attached to a formwork 1.

[Problem that the invention attempts to solve]

In the conventional support structure of the bearing pressure plate 4 as described above,
When pouring concrete 10 after setting the unbonded PC steel bars 5 and PC steel bar mounting bolts 6, support may be affected by the pressure of the concrete at the time of concrete pouring, the vibrations during vibration compaction of concrete, etc. When the pressure plate moves and the concrete hardens, the perpendicularity between the PC steel bar 5 and the bearing plate 4 may be lost when stress is introduced by screwing a tension nut onto the unbonded PC steel bar, resulting in misalignment of stress introduction. There is.

The present invention aims to solve these conventional problems.

[Means for solving problems]

In order to achieve the above object, the present invention solves the problems through the following technical means.

Attach a flange that contacts the outside surface of the formwork to the large-diameter end of the recessed metal fitting that has a truncated conical outside diameter, and provide a seat on which the mounting bolt of the PC steel bar will sit.

Provide a screw at the small diameter end. This screw screws the bearing plate parallel to the seat.

[Effect]

With the above configuration, the recessed metal fitting supporting the bearing pressure plate of the present invention has the following functions.

(b) The perpendicularity of the PC steel rod and bearing plate is maintained, and the position of the bearing plate is not deformed by the pressure of poured concrete or vibrations during compaction.

(b) The bearing pressure plate and bearing plate support can be easily and stably fixed using screws. After the concrete has hardened, the screws can be easily removed and the recessed metal fittings can be easily removed.

〔Example〕

FIG. 1 shows an embodiment of the present invention.

The recessed metal fitting 2 of the present invention has a flange 2a at its large diameter end, is attached to the formwork 1 with this flange 2a in contact with the outer surface of the formwork 1, and is attached to the formwork 1 at its small diameter end, that is, at the inner tip of the formwork. has a screw 2b in the part,
The bearing pressure plate 4 is screwed onto this screw 2b.

On the other hand, the unbonded PC steel rod 5 is inserted through the center of the recessed metal fitting 2, and its both ends are fixed to the formwork 1 with PC steel rod attachment bolts 6. At this time, the head of the PC steel bar mounting bolt 6 is seated on the seat 2c at the large diameter end of the recessed metal fitting 2.

Since the recessed fittings 2 are formed so that the bearing plate 4 and the seat 2C of the PC steel bar mounting bolt are parallel to each other, the bearing surface 4a of the bearing plate 4 and the unbonded PC steel bar 5 are kept at right angles. There is. After pouring concrete, remove the PC steel bar attachment bolts 6, remove the recessed fittings 2 by twisting the flange 2a, and remove the formwork 1, and the unbonded PC steel rods 5 remain in the recess where the recessed fittings were removed. Since the bearing plate 4 is embedded in the concrete with the bearing surface 4a kept perpendicular to the PC steel rod 5, a tension nut for introducing stress is screwed into the unbonded PC steel rod 5, and this tension nut is tightened with an impact wrench. When the tension nut is tightened by means of a screw or the like and stress is introduced, the tension nut comes into close contact with the bearing pressure plate 4.

Therefore, the problem of the tension nut hitting the bearing pressure plate unevenly when stress is introduced as in the conventional case is eliminated, and a normal stress state can be maintained.

[Effect of idea]

a The perpendicularity of the PC steel rod and bearing plate can be maintained at all times, and it is not affected by the pressure during concrete pouring or the vibration during compaction.

b Stress introduction is performed correctly and accurately.

c It has a simple and inexpensive structure and can be used repeatedly.

[Brief explanation of drawings]

FIG. 1 is a vertical cross-sectional view of an embodiment of the present invention, FIG.
FIG. 3 is a sectional view showing a conventional structure. 1... Formwork, 2... Dent fittings (supporting tools), 3
...Magnet, 4...Bearing plate, 5...Unbonded PC steel bar, 6...PC steel bar mounting bolt, 7...Fixing spring, 10...Concrete.

Claims (1)

[Scope of utility model registration request] In the bearing plate mounting bracket for unbonded PC steel bars in post-tension prestressed concrete formwork, a flange that contacts the outside surface of the formwork is attached to the large-diameter end of the recessed metal fitting that has a truncated conical outer diameter, and the PC steel bar A bearing plate support for an unbonded PC steel bar, characterized in that a seat is provided on which a mounting bolt is seated, and a screw is provided at a small diameter end of the recessed metal fitting to threadably engage the bearing plate in parallel with the seat.