JP2002339279A - Tensile cable for building and engineering work - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an inexpensive tensile cable for building and engineering work enabling ready construction. SOLUTION: This tensile cable 10 for building and engineering work is obtained by bringing many steel wire into contact with each other directly or through coat of extremely thin synthetic resin material, twisting many steel wires together, packing a synthetic resin material 15 into spaces among steel wires and bundling rustproof strands 11 whose outer periphery is coated with the synthetic resin material to use the bundle as one cable 10. In the tensile cable 10, the rustproof strand 11 formed by twisting side wires 13 and 14 composed of PC steel wire in multilayered state together around a core wire 12 composed of PC steel wire is used to increase allowable load of the rustproof strand 11.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a diagonal member for a cable-stayed bridge and a tension cable for construction civil engineering used as a cable outside a PC.

[0002]

2. Description of the Related Art Conventionally, a diagonal member for supporting a bridge girder of a cable-stayed bridge,
A pulling cable 1 is used as an external cable for reinforcing a structure.
As shown in the figure, a large number of anti-rust strands
The book has a cable. Generally, anti-rust strand 2
As shown in FIG. 5, a seven-strand anticorrosive strand is used, and side wires 4, 4... Made of PC steel wire are twisted around the outer periphery of a core wire 3 made of PC steel wire. The space between them is filled with a synthetic resin material 5, and the outer periphery of the rust preventive strand 2 is similarly coated with the synthetic resin material 5 for rust prevention.

[0003]

However, in the prior art as described above, for example, when used as an external cable, it is necessary to bundle a considerable number of cables in order to satisfy the standard as a diagonal material. There is a problem that the construction cost increases and the construction period is prolonged.

Further, since a large number of rust-preventive strands are used in a bundle, there are many places where the rust-preventive strands come into contact with each other.
There is also a problem that the rust-preventive strand is worn at the contact point and the rust-preventive coating on the surface of the rust-preventive strand is crushed.

Further, in the conventional rust-preventive strand, when the outer diameter becomes 21.8 mm or more (for example, 28.6 mm), the core wire of the rust-preventive strand is loosened when the tension cable is pulled, and is used. Had a problem.

The present invention has been made in view of the circumstances of the related art, and has as its object to provide an inexpensive and efficient construction tensile cable for civil engineering.

[0007]

SUMMARY OF THE INVENTION The features of the present invention for solving the conventional problems as described above and achieving the intended purpose are as follows.
A large number of steel wires are contacted with each other directly or through a very thin synthetic resin material coating and twisted, and a synthetic resin material is filled between the steel wires, and a large number of protective wires whose outer periphery is coated with the synthetic resin material are twisted. In a tensile cable for construction and civil engineering using rusted strands bundled together and used as a single cable, multi-layer rust prevention formed by twisting the side wire made of PC steel wire around the core wire made of PC steel wire in multiple layers. That is, the allowable tensile load of the rust preventive strand is increased by using the strand.

It is preferred that the rust-preventing strands be twisted in 19 strands, and that a strong adhesion promoter be added to the synthetic resin material filled between the PC steel wires.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, an embodiment of a tension cable for building civil engineering according to the present invention will be described with reference to FIGS.

In the drawing, reference numeral 10 denotes a tension cable used for a diagonal member of a cable-stayed bridge or a cable outside a PC. This tension cable 10 has a large number of rust-preventive strands 11, 11,.
Are bundled into one.

As shown in FIG. 2, the rust-preventive strand 11 includes a core wire 12 made of a PC steel wire, and middle-layer side wires 13, 13... Which are twisted around the outer periphery of the core wire 12 to form an inner layer.
A number of outer layer survey lines 14 twisted around the inner layer
14 ... are formed in a multilayer shape.

The inner space of the rust-preventive strand, that is, the space formed between the middle layer side lines 13, 13 and the outer layer side lines 14, 14, ... is made of a synthetic resin material 1 containing a strong adhesion promoter.
5, the core wire 12 and the side wire are fixed to each other so that the core wire 12 does not slip easily even when an external force is applied to the cable.

The outer peripheral surface of the anti-rust strand 11 is coated with a synthetic resin material 15 for anti-rust.

The rust-preventive strand has an outer diameter of 28.6 m.
m.

With such a configuration, the allowable load per rust-preventive strand increases, and when forming a tension cable for building civil engineering, a smaller number of rust-preventive strands can satisfy the standard value. As a result, the number of pieces can be reduced, so that material costs can be reduced and the construction period can be shortened, and costs can be reduced.

In addition, since the number of the rust-preventive strands is small, the number of places where the rust-preventive strands come into contact with each other can be reduced, and the crushing or peeling of the synthetic resin material due to friction can be minimized.

In the above-described embodiment, an example was described in which the rust-preventing strands were twisted to 19 strands. However, the rust-preventing strands may be twisted to 15 strands, and the outer diameter of the rust-preventing strands was set to 21.8 mm. Is also good.

Further, in the above-described embodiment, an example in which the synthetic resin material 15 is coated along the shape of the rust-preventive strand has been described. However, as shown in FIG. 3, the cross-sectional shape of the rust-preventive strand 11 is circular. As described above, the outer periphery of the rust-preventive strand 11 may be covered with the synthetic resin material 15.

[0019]

As described above, in the tensile cable for civil engineering construction according to the present invention, a large number of steel wires are twisted by abutting each other directly or via a coating of an ultra-thin synthetic resin material. A tension cable for construction and civil engineering that is used as a single cable by bundling a number of rust-preventive strands that are filled with a synthetic resin material and whose outer periphery is covered with a synthetic resin material.
By increasing the allowable tensile load of the rust-preventive strand by using a multi-layer rust-preventive strand formed by twisting a side wire composed of a PC steel wire into a multi-layer around the outer periphery of a core wire composed of a steel wire. In addition, the number of rust-preventing strands constituting the pulling cable can be reduced, and the number of rust-preventing strands can be reduced, so that the material cost can be reduced and the construction period can be shortened, and the cost can be reduced.

Further, by allowing the 19 anticorrosive strands to be twisted, the allowable load of the anticorrosive strand can be suitably increased.

Further, a strong adhesion promoter is added to the synthetic resin material filled between the PC steel wires, so that the outside diameter is 21.8 mm or more, for example, 28.6 mm outside diameter.
The core wire does not loosen when the tension wire is tensioned even with the PC strand.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a tension cable for building civil engineering according to the present invention.

FIG. 2 is a sectional view showing the rust-preventive strand according to the first embodiment.

FIG. 3 is a cross-sectional view showing an example of another rust preventive strand of the above.

FIG. 4 is a sectional view showing a conventional tension cable.

FIG. 5 is a sectional view showing the rust-preventive strand according to the first embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Tensile cable 11 Rust prevention strand 12 Core wire 13 Middle side wire 14 Outer side wire 15 Synthetic resin material

Continued on the front page F term (reference) 2D059 AA42 BB08 GG02 2E164 AA02 AA31 DA03 3B153 AA14 AA15 AA34 AA45 AA47 BB15 CC52 CC80 FF03 GG01 GG07

Claims (3)

[Claims] 1. A number of steel wires are abutted with each other directly or through a coating of an extremely thin synthetic resin material and twisted together, a synthetic resin material is filled between the steel wires, and the outer periphery is covered with the synthetic resin material. In a tensile cable for construction and civil engineering, which is used as a single cable by bundling a large number of rust-preventive strands, a multi-layered cable formed by twisting a side wire made of a PC steel wire around a core wire made of a PC steel wire in a multilayered manner. A tensile cable for construction and civil engineering, characterized by using a layered twisted rust-preventive strand to increase the allowable tensile load of said rust-preventive strand. 2. The tensile cable for building civil engineering according to claim 1, wherein the rust-preventive strand is made of 19 strands. 3. The tensile cable for building civil engineering according to claim 1, wherein a strong adhesion promoter is added to the synthetic resin material filled between the PC steel wires.