JPS6230884B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method and apparatus for forming a space for embedding a terminal fitting of prestressing steel material in concrete.

Conventionally, as a method of forming a space for burying a terminal fitting of PC steel material in concorite,
It is done to enclose the end of the prestressed steel material with a formwork or use special equipment.
In the former case, the space must be enlarged to a certain extent, making the work of filling the space with mortar expensive, and in the latter case, the equipment is complicated and expensive.

The present invention has been made to solve these conventional drawbacks, and provides a method and device that can minimize the space to be formed and that also has a simple device and is easy to work with. It is.

The present invention will be explained below with reference to drawings of embodiments. In Fig. 1, 1 is a bearing plate, 3 is a metal pipe,
4 is a cylindrical body, and 6 is a spacer. A screw hole 11 is formed in the center of the bearing pressure plate 1, and the screw hole 11 is screwed into a threaded portion 31 formed on the outer periphery of one end of the metal tube 3.
A nut 5 is screwed onto the threaded portion 32 at the other end of the metal tube 3. Further, the metal tube 3 is inserted into the center hole 60 of the spacer 6, and the cylindrical body 4 is fitted onto the spacer 6 so that the cylindrical body is arranged concentrically with the metal tube 3.

A method for forming a space at the end of a PC steel material using this device will be explained. As shown in FIG. 2, a bearing plate 1 is arranged inside a formwork 2 with a cylindrical body 4 interposed therebetween, one end of the metal tube 3 is screwed into the screw hole 11 of the bearing plate 1, and the other end is screwed into the screw hole 11 of the bearing plate 1. The metal tube 3 is made to protrude from the hole 20 of the formwork 2 to the outside, and a spacer 6 is fitted onto the metal tube 3 so that the metal tube 3 is arranged concentrically with the cylindrical body 4. By screwing a nut 5 onto the protruding end of the metal tube 3, the bearing plate 1 is drawn and fixed to the formwork 2 through the metal tube 3. Further, the metal tube case 7 is inserted into the screw hole 11 of the bearing pressure plate 1 from the opposite side.

In this state, concrete 15 is poured, and after the concrete hardens, nuts 5, formwork 2, spacers 6,
Remove the metal tube 3 and cylindrical body 4. As a result, a space 80 is formed as shown in FIG. PC
Insert the steel material 9, place the terminal fitting 8 at a predetermined position, apply tightening tension to the PC steel material 9 using jacks (not shown), press-fit the wedge 81, and press the terminal fitting 8.
is fixed to the PC steel material 9. Next, grout is injected into the sheath from the grout injection pipe 70, and the PC steel material 9 on the terminal side from the terminal fitting 8 is cut to fill the space 8.
Fill the inside with mortar. Note that the prestressing steel material may be inserted into the sheath before concrete placement.

FIG. 4 shows an example in which the present invention is applied to the unbonded construction method, in which the sheathed PC steel material 11 is penetrated through the bearing plate 1 and the metal pipe 10 before concrete placement. After concrete hardens, remove nuts 5, etc.
The sheath 12 is cut at the surface of the bearing plate. Then, a terminal tool (not shown) is installed in the space 80, and tension is applied to the PC steel material 10 by a jack (not shown).
The terminal fitting is fixed to the PC steel material 10 within the space 80. The terminal tool is usually a grip in the case of PC steel stranded wire, or a nut by forming a thread on the surface of the PC steel material.

As described above, according to the present invention, by using a simple device, a predetermined space can be formed by simply forming a metal pipe through hole in the formwork, and this space can be kept to the minimum necessary. Since it can be set to 1, filling the mortar is easy. Furthermore, since the metal tube, spacer, and nut of this device can be used repeatedly, the cost of the device is very low.

[Brief explanation of the drawing]

Fig. 1 is an exploded perspective view of the device of the present invention, Fig. 2 is a sectional view of its implementation state, Fig. 3 is a sectional view showing the situation after prestress is introduced, and Fig. 4 is a sectional view showing another embodiment. It is. 1... Bearing plate, 2... Formwork, 3... Metal tube, 4
... Cylindrical body, 5 ... Nut, 6 ... Spacer,
9,10...PC steel material.

Claims (1)

[Scope of Claims] 1. A bearing plate having a threaded hole in the center is arranged in a concrete formwork with a cylindrical body interposed between it and the formwork, and one end of a metal pipe having threads on the outer peripheral surface of both ends. One end is screwed into the screw hole of the bearing pressure plate, and the other end is passed through the cylindrical body and protrudes outside through the hole in the formwork, and a spacer is provided between the metal tube and the cylindrical body to keep them concentric. The bearing plate and cylindrical body are fixed to the formwork by intervening and nuts attached to the protruding part of the metal pipe, and the sheath or sheathed PC steel material is inserted into the center hole of the bearing plate, and then concrete is poured. , concrete formwork after hardening, metal pipes,
A method for forming a tension space in a prestressed steel material, which includes removing a cylindrical body and a spacer, applying tightening tension to the prestressed steel material, and attaching a terminal tool to the prestressed steel material. 2. A metal tube that has threaded parts on the outer peripheral surface of both ends and into which the prestressing steel material is inserted, a bearing plate that has a threaded hole in the center that is screwed into this threaded part, and A cylindrical body arranged concentrically with the metal tube to form a constant interval, a spacer interposed between the metal tube and the cylindrical body to maintain a constant distance between them, and a spacer screwed onto the other end of the metal tube. A space forming device for tensioning a PC steel material, characterized in that it has a nut.