JPH0540169Y2 - - Google Patents

Description

[Detailed description of the invention] [Industrial application field] The present invention is an end fixing device for tendons used in prestressed concrete, specifically, an end fixing device for tendons made of fiber reinforced resin used during prestressed concrete construction. This invention relates to a female cone-shaped tool made of fiber-reinforced resin used for

[Prior art]

Conventionally, steel wires with excellent tensile strength have been used as tendons for prestressed concrete, and this end fixture consists of a metal male cone 1 and a metal female cone 2, as shown in Figure 1. Press-fit wedges have been commonly used. The tension material 3 is introduced into the through hole 5 of the female cone 2 and the cavity 6 of the male cone 1 through the bearing plate 4, and is strongly gripped by the wedge action of the male cone 1 to prevent it from coming off.

[Problem that the invention attempts to solve]

Recently, problems have arisen in which steel wires, which have traditionally been used as tendons, are subject to alkaline corrosion due to the high alkalinity of concrete, causing them to expand, causing cracks in the concrete, or causing the steel wires to break. . In order to solve this problem, tendons made of fiber-reinforced resins have been developed that have tensile strength comparable to or higher than steel wire tendons, are lightweight, and have excellent corrosion resistance. In line with this, a fixture for fixing the ends of this tendon material has also been proposed (Utility Model No. 61-
No. 94111). However, the proposed fixing device has problems in terms of workability when used as an end fixing device that is directly embedded in concrete, a so-called det anchor.

When embedded in concrete,
The present invention provides a tendon end fixing device made of fiber-reinforced resin that can withstand the high alkalinity of concrete and does not lose strength.

[Means for solving problems] The present invention is as follows.

In an end fixture for a fiber-reinforced resin tendon for use in prestressed concrete, the end fixture is made of fiber-reinforced resin and has a female cone shape, and the fiber angle of the fiber-reinforced resin in the end fixture is 0° to 10° relative to the tendon.
An end fixing device characterized by being composed of an outer layer which is ±10° and an inner layer which is ±80° to 90°.

The present invention will be explained below with reference to the drawings.

FIG. 2 is a cross-sectional view of the tension member 3 fixed using the end fixing device 8 of the present invention.

After the tension material 3 is inserted into the cone-shaped fixture 8 of the present invention, a resin 9 having excellent alkali resistance is poured and cured to prevent it from coming off by adhesion.

FIG. 3 is a cross-sectional view of the end fixture of the present invention in use.

The female cone-shaped end fixture 8 is composed of an outer layer 10 in which the fiber angle of reinforcing fibers is 0° to ±10° with respect to the tendon, and an inner layer 11 in which the fiber angle is ±80° to 90°.

The outer layer 10 and the inner layer 11 may each be a multilayer laminate.

The outer layer 10 of 0° to ±10° receives the compressive force generated against the bearing plate by the tensile force of the tendon, and the outer layer 10 has a range of ±80° to
The 90° inner layer 11 receives tensile force due to the internal pressure transmitted through the resin layer 9.

Conventionally, fixing devices for prestressed concrete made of fiber-reinforced resin have been known (Japanese Unexamined Patent Application Publication No. 1983-1999).
63746). The anchor shown here uses both glass fiber and carbon fiber as reinforcing materials, and is reinforced using the filament winding method or woven fabric. , there is no proposal for arranging the reinforcement in a particular orientation.

The reinforcing fibers used in the end fixture of the present invention are carbon fibers, aramid fibers, etc., and these may be used alone or in combination.

The resins used include thermosetting resins (epoxy resins, phenolic resins, etc.), thermoplastic resins (polysulfone, polyethersulfone, polyetherketone, polyetheretherketone, aromatic polyamide, aromatic polyester, aromatic polycarbonate, polyetherimide, polyphenylene sulfide, etc.).

The fiber-reinforced resin constituting the tension material is also the same as described above, but the types of fibers and resins do not necessarily have to be the same.

[Effect of idea]

The fiber-reinforced resin end fixture of the present invention is used as an end fixture for fiber-reinforced resin tendons, and is not corroded by the high alkali of concrete, does not deteriorate in strength over time, and is By specifying the orientation configuration, the outer layer receives the compressive force generated against the bearing plate due to the tensile force of the tendon, and the inner layer receives the tensile force due to the internal pressure. As a result, the strength of the reinforcing fibers can be fully utilized, and it has high practical value as a fixture for tendons used in prestressed concrete.

[Brief explanation of the drawing]

Fig. 1 is a sectional view of a conventional end fixture in use, Fig. 2 is a sectional view of the end fixture of the present invention in use, and Fig. 3 is a sectional view of the end fixture of the present invention. FIG. In the figure, 1 is a metal male cone, 2 is a metal female cone, 3 is a tendon, 4 is a bearing plate, 5 is a through hole in the female cone, 6 is a gap in the male cone, 7 is a concrete wall, and 8 is a In the end fixing device of the present invention, 9 is a resin layer, 10 is an outer layer with a reinforcing fiber angle of 0° to ±10°,
Reference numeral 11 indicates an inner layer in which the reinforcing fiber angle is ±80° to 90°.

Claims (1)

[Scope of Claim for Utility Model Registration] 1. An end fixture for fiber reinforced resin tendons for prestressed concrete that is made of fiber reinforced resin and has a female cone shape, in which the fiber angle of the fiber reinforced resin in the end fixture is tensioned. An end fixture comprising an outer layer having an angle of 0° to ±10° to the material and an inner layer having an angle of ±80° to 90°. 2. The end fixture according to claim 1, wherein the fiber-reinforced resin in the end fixture is carbon fiber-reinforced resin.