JPS62137364A - Apparatus for introducing prestress into concrete - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an apparatus for introducing prestress into concrete in a prestressed concrete construction method using a post-tensioning method.

(Prior art) Figures 5 and 6 show an example of a conventional prestressed concrete construction method using a post-tensioning method, in which a sheath (1) is installed in a formwork (not shown) at the same time as reinforcement work, Conc IJ-) +21 is cast in the formwork and after hardening, the PC steel material (3) is inserted into the sheath (1), and one end of the PC steel material (3) is secured with a nut (4) and a washer (
It is anchored to one end of the concrete (2) via the concrete (2), the other end is tensioned with the jack (6), and in this state the PC steel (
3) After tightening the other end to the other end of the concrete (2) with the nut (4) and washer (5), tighten the jack (6).
) is released and compressive stress is introduced into the concrete (2).

(Problems to be Solved by the Invention) The conventional prestressed concrete construction method using the post-tensioning method requires a large amount of labor and construction time because it is necessary to apply tension to the prestressing steel using a set of jacks on site. It requires.

There were also problems such as difficulty in controlling the tension of the PC#J4 material due to on-site construction.

(Means for Solving the Problems) The present invention has been proposed to solve these problems, and is a PC @ equipped with a pair of tightening jigs at both ends.
A rod, a steel pipe into which the PC steel rod is inserted, a pair of presser plates that are fitted onto the PC steel rod on the outside of both ends of the steel pipe and have a stopper on at least one side that protrudes outward, and the presser plate. It consists of a slide plate that is slidably fitted to the PC @ rod in a direction perpendicular to the axis of the PC steel rod on the outside of the plate, and has a through hole into which the stopper of the presser plate can be inserted and engaged. This invention relates to a concrete prestress introducing device characterized by the following.

(Function) Since the prestress introducing device according to the present invention is configured as described above, it is assembled in advance at a factory etc. in a state in which the retaining plate of the presser plate collides with the inner surface of the slide plate, and then tightened onto the PC steel bar. When the required tension is applied with a tool or other appropriate means and tightened with a tightening jig in this state, the tension of the PC steel bar is supported by the steel pipe via the slide plate, the stopper, and the holding plate.

The prestress introduction device set in this state is installed in a concrete formwork and concrete is poured,
After hardening, when the slide plate is slid against the PC steel rod in a direction perpendicular to its axis, the retaining plate of the holding plate is inserted into the through hole of the slide plate and engaged.

The tension of the PCf84 rod, which was previously supported by the steel pipe, is released and is supported by the concrete part via the holding plate, so that a compressive stress commensurate with the tension is introduced into the concrete part.

(Effect of the invention J$) In this way, the prestress introducing device according to the present invention is assembled in advance at a factory, etc., and set in a concrete formwork on site, and the slide plate is moved in the direction perpendicular to the PC steel bar. Prestress can be introduced into the concrete simply by sliding it, which greatly simplifies on-site work. Furthermore, the device of the present invention can be manufactured in a factory.

The tension can be easily managed, and the steel pipe after the tension has been released can be used as a substitute for reinforcing steel.

(Example) The present invention will be described below with reference to the illustrated embodiments.

(11) is a steel pipe, and a PC steel rod α4 with nuts α4 as a tightening jig screwed onto both ends of the steel pipe (11) and a pair of holding plates α2 arranged at both ends thereof. is penetrated.

A stopper (151) is provided protrudingly on the outside of at least one of the holding plates σ2, and a PC is mounted on the outside of the holding plate α2 facing
Example C Steel Bar A slide plate αe that is slidable in a direction perpendicular to the axis of the steel bar I is fitted. The slide plate αG is provided with a through hole (17) into which the stopper α9 is inserted and engaged.

As mentioned above, after assembling the prestress introduction device in advance at a factory, etc., apply a predetermined tension to the PCC steel bar using a tightening nut or other appropriate means, and fix it in this state with the tightening screw Q3. The tension force of the PC steel rod is supported by the steel pipe (111) via the slide plate (161, stopper Q5 that collides with the same plate αυ) and the holding plate α2.

The prestress introducing device set in this state is installed in a concrete formwork (not shown) on site and the concrete is ready! J-) (Place 1).

In this case, the concrete part sec is the holding plate α2 on the left end side.
As shown in FIG. 3, the right end side is driven to a position in contact with the presser plate α2 and the slide plate αe.

Thus, when the poured concrete (2) hardens.

Slide plate (le in the direction of the arrow in Fig. 3) - Hit with a hammer or the like to slide it in a direction perpendicular to the axis of the PC steel rod α4.

As shown in Fig. 4, when the stopper α group is inserted and engaged with the through hole αη of the slide plate αG, the tension of the PC steel IIa41, which had been supported by the steel pipe αυ, is released and the concrete (l& A compressive force commensurate with the tension force is introduced into the slide plate (concrete) 08 as prestress, which is transmitted through the slide plate (le).

As described above, according to the embodiment, the prestress introduction device is pre-assembled in a factory or the like.

Prestressing can be easily applied to concrete on site, greatly simplifying on-site work. In addition, since the prestress introduction device can be manufactured in a factory, it is possible to
Tensioning of the rod (1) is easily done, and the steel pipe αD after the tension is released can be used as a substitute for reinforcing bars.

Although the present invention has been described above with reference to embodiments, the present invention is, of course, not limited to such embodiments, and can be modified in various designs without departing from the spirit of the present invention. .

[Brief explanation of drawings]

FIG. 1 is a front view showing an embodiment of the concrete prestress introduction device according to the present invention, and FIG.
- Figures 3 and 4 are partial vertical cross-sectional views showing the prestress introduction process using the above-mentioned equipment, Figure 5 is a front view showing the implementation status of the conventional prestressed concrete method, and Figure 6 is Figure 5. This is a view from ■-■. CIf)...-Steel pipe, α2... Holding plate, (13...
Tightening nut, α button...PC steel bar, a9...-clasp, (
1θ...Slide plate, (171...Through hole. Sub-agent: Patent attorney Shige Okamoto, 2 other people)

Claims (1)

[Claims] A PC steel rod equipped with a pair of tightening jigs at both ends, a steel pipe into which the PC steel rod is inserted, and the PC steel rod is fitted to the outside of both ends of the steel pipe, and at least one side protrudes outward. a pair of presser plates provided with clasps, and slidably fitted to the PC steel rod in a direction perpendicular to the axis of the PC steel rod on the outside of the presser plates, and the clasp of the presser plates is inserted; A device for introducing prestress into concrete, comprising a slide plate having an engageable through hole.