JP2568694Y2 - 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 a PC steel used for a concrete structure.

[0002]

2. Description of the Related Art Conventional PC steel materials are roughly classified into three types: PC steel rods, PC steel wires, and PC steel stranded wires. Of these, when several PC steel wires or PC steel stranded wires are used collectively as tendons, a phenomenon called wire boring may occur. This is because the conventionally used PC steel wires or twisted PC steel wires all had a circular cross-sectional shape, and when a plurality of these PC steel materials were sequentially inserted into the duct, the PC steel material inserted later was not used. This is a phenomenon in which PC steel materials already provided are entrapped. FIG. 3 shows an arrangement state of the PC steel material in the duct 22, and each numeral indicates an insertion order.
As shown in FIG. 5A, the layers are stacked from the bottom in the order of insertion near the insertion port of the duct, but at locations away from the insertion port, as shown in FIG. However, there is a case where the later wire is entrapped between the existing wires, and the earlier wire is positioned at the top. When such wire boring occurs, there is a problem that a load of a predetermined value or more may be applied to the wire.

Further, when a PC steel stranded wire is applied to a structure having a thin section of a member, so-called rise and eccentricity cannot be sufficiently increased due to the thickness of the cover concrete, and the thickness of the PC steel stranded wire itself is applied. It is a factor that restricts the target.
Furthermore, in order to twist the wire rod, the twisted PC steel wire
There is also a problem that the elastic modulus is lower than that of PC steel wire.

The present invention has been made to solve the above-mentioned problem, and an object of the present invention is to provide a PC steel material which does not cause wire boring during construction and has few restrictions on applicable structures. is there.

[0005]

In order to solve the above-mentioned problems, the PC steel of the present invention has an outer dimension of 1.0 mm to 10.0 mm.
A plurality of steel wires having a tensile strength of 160 kg / mm ² or more in mm are arranged in parallel and integrated.

The steel wire used here may have a circular cross section or a non-circular cross section. When the cross-sectional shape is circular, the outer dimension indicates the diameter, and when the cross-sectional shape is non-circular, the outer dimension refers to the maximum dimension of the wire rod cross section. The reason why the outer dimensions of the steel wire are limited as described above is that if the diameter is less than 1.0 mm, the strength is not sufficient, and if the diameter is more than 10.0 mm, it is inappropriate for use in a structure having a thin cross section. The reason why the tensile strength is set to 160 kg / mm ² or more is that if it is less than that, a sufficient PC steel material cannot be obtained in terms of strength.

Means for integrating steel wires in a parallel state is as follows:
For example, it is performed by fixing an adjacent wire rod with an adhesive or by crimping using a metal sleeve over the end or the entire length of the steel wire. Here, the number of parallel lines is generally 3 to 19 lines.

[0008]

As described above, by integrating a plurality of steel wires in parallel, a wide flat cable as a PC steel material is obtained.
When installing this in a duct, the PC inserted afterwards
Since the steel material is placed in order on the existing PC steel material, so-called wire boring does not occur. Further, since the wire has a flat shape, the wire can be applied to a thin structure, and the thickness itself of the wire does not limit the application target as in the case of a conventional stranded PC steel wire. In particular, if the duct is a flat one, it is possible to more effectively prevent the wire from being dug and apply it to a thin structure.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. FIG. 1A is a perspective view of an embodiment of the present invention. As shown, seven steel wires 1 each having a diameter of 4 mm are arranged in parallel, and the space between the steel wires 1 is shown in FIG. As described above, they were fixed by the adhesive 2 and integrated. A case where such a PC steel material is disposed in a slab will be described. As shown in FIG. 2A, a duct 12 is embedded in the slab.
The PC steel material 10 is inserted from one end. This duct 12
As shown in FIG. 2B, the cross section is flat, and when a plurality of PC steel materials 10 are sequentially inserted, the PC steel material 10 inserted later is the PC steel material already provided. Are arranged one after the other while sliding on the top. For this reason,
Since so-called wire boring does not occur and the thickness is smaller than that of a conventional twisted PC steel wire or the like, it can be easily applied to thin structures.

[0010]

As described above, the PC steel of the present invention has the following effects. Since a plurality of wires are integrated in parallel, the wires are so wide that so-called wire boring does not occur when the wires are arranged in a duct. Thus, it is possible to prevent a load equal to or more than a predetermined value from being applied to the PC steel material. Since it has a flat cross section, it can be applied to a wide range of structures. In particular, it can be easily applied to thin structures and the like. The configuration of the PC steel material (external dimensions of the steel wire and the number of parallel wires) can be selected relatively freely without particularly large changes to the production equipment, so that the steel material suitable for the structure can be obtained and the prestressing force can be easily controlled. . By arranging a plurality of steel wires in parallel, for example, P using seven or nineteen wire rods
Compared with the stranded C steel wire, the area of attachment to the external concrete is large, and it effectively acts on the load applied to the structure. Since the cross section is flat, it can be wound with a small bending radius when stored and transported after being wound within the elastic range, and the overall shape can be reduced.

[Brief description of the drawings]

1A is a cross-sectional view of a PC steel material of the present invention, and FIG. 1B is a cross-sectional view showing each wire bonding portion of the steel material.

FIG. 2 (A) is an explanatory view showing the arrangement of the PC steel material of the present invention in the duct, and FIG. 2 (B) is a cross-sectional view showing the arrangement state of the PC steel material in the duct.

3A and 3B are explanatory diagrams of wire boring when a conventional twisted PC steel wire is provided in a duct. FIG. 3A shows a case where wires are provided in order, and FIG. 3B shows a wire boring. Show the case.

[Explanation of symbols]

 1, 11 steel wire 2 adhesive 10 PC steel 12, 22 duct 20 PC steel wire or PC steel stranded wire

Claims (1)

(57) [Scope of request for utility model registration] 1. The outer dimensions are from 1.0 mm to 10.0 mm,
A PC steel material comprising a plurality of steel wires having a tensile strength of 160 kg / mm ² or more arranged in parallel and integrated.