JPH0542169Y2 - - Google Patents

Description

[Detailed description of the invention] [Industrial application field] This invention relates to an anchorage structure in which tension members made of fiber-reinforced synthetic resin (FRP) are anchored in ground anchors, prestressed structures, etc.

[Problem that the invention attempts to solve]

FRP rods reinforced with fibers such as carbon fibers, aromatic polyamide fibers, and glass fibers have high tensile strength, corrosion resistance, light weight, and electrical insulation properties (excluding carbon fibers), making them suitable for use in the ground as an alternative to steel materials. The use of anchors or tension members in prestressed concrete structures is attracting attention.

However, these FRP rods cannot be attached to a fixing structure like conventional steel tendons, such as a structure in which a screw is cut into the rod and a fixing plate or the like is screwed into the rod. There is also a proposal to insert the end into the mantle tube of the fixing device, fill it with adhesive and fix it to the mantle tube, but organic adhesive and
Synthetic resins, which are the base material of FRP rods, are easily destroyed by shearing forces, and it is difficult to achieve high adhesion strength against pulling out.

This idea was made in view of the above circumstances. The purpose is to propose an anchorage structure for FRP tendons that has high adhesion strength between the FRP tendons and the anchor tube, and that can be buried in ground anchors or prestressed concrete structures to exhibit high anchorage strength. It's about doing.

[Means for solving problems]

The embodiments shown in FIGS. 1 and 2 will be explained below. The structure of the anchoring part of this tendon is to use aromatic polyamide long fiber bundles as reinforcing fibers, and the ends of the tendon, which is 8 mm in diameter and consists of RFP rods 1 whose base material is epoxy resin, have an outer diameter of 30 mm and a circular cross section. It is inserted into a dovetail-shaped hole 3 with a circular cross section, which is bored in the outer tube 2 of the tube. A split 4 is cut into the end of the rod 1 along the longitudinal direction from the end to divide the cross section into eight equal parts in the radial direction, and a cannonball-shaped hell wedge 5 is inserted in the center of the split 4 to divide the tip of the rod 1 into 8 parts. It is split open into a shape approximately equal to the dovetail shape of the hole 3 and inserted along the inner surface of the hole 3. Then, an adhesive resin 6 made of epoxy resin is filled and hardened between the cracks 4, 4, the interface with the hole 3, and the interface with the hell wedge 5, and
An edge cutting film 7 is inserted inside.

To assemble this anchor structure, the hole 3 of the outer tube 2 must be
After laying the edge-cutting film 7 on the bottom of the film, placing the Jigoku Wedge 5 upright in the center thereof, and injecting a predetermined amount of the final cured epoxy resin composition to fill the gap,
Insert the rod 1 with a notch in the tip into the center of the hole 3. The tip of the rod 1 is split open in a dovetail shape by a hell wedge 5, and the gap is filled with a flowing and cured resin composition, and the assembly is completed when the composition is cured. During this assembly, if the hell wedge 5 is adhesively fixed to the edge-cutting film 7 in advance and placed at the same time as the film 7 is laid, it can be easily and stably erected, and the workability of the assembly can be improved. In addition to the assembly example of the structure described above, for example, the outer tube 2 is provided with a small through hole for resin injection that communicates with the hole 3, and after being cut open in the shape of a rod dovetail and inserted, the resin is injected through the small through hole. Various methods can be used, such as injecting the composition and curing it.

[Effects of action and design]

The structure of the anchoring part of this tendon consists of the above-mentioned structure, and the end of the FRP tendon is split open in a dovetail shape.
Since the rod is inserted into a dovetail-shaped outer tube hole, the pulling force acting on the rod can be dispersed and supported on the dovetail-shaped open surface, and compared to cases where stress is concentrated, it is less likely to destroy the base material resin or reinforcing fibers. breakage is unlikely to occur. The rod end is inserted in a dovetail shape that is approximately the same shape as the hole, and the interface gap with the hole can be made extremely narrow, preventing damage due to shearing of the adhesive resin and increasing the adhesion strength between the rod and the outer tube. can be increased. In addition, an edge-cutting film is inserted at the bottom of the hole, and the edges of the hell wedge and rod tip are cut off from the bottom of the hole, so the rod and hell wedge behave as one with respect to the hole.
It can resist withdrawal from the hole.

The anchorage structure of this tension member is as described above, so it is anchored by being buried in the grout of the anchor body or in a prestressed concrete structure, etc.
It is capable of supporting high tension forces introduced into the tendons.

Note that the outer tube of this fixing part structure can also be screwed together and fixed by cutting a thread on the outer surface. Furthermore, since FRP rods are used, there is an advantage that anti-corrosion treatment is not required compared to when using PC steel wires, etc.

[Brief explanation of the drawing]

1 and 2 are a longitudinal cross-sectional view and an A-A cross-sectional view of the fixing part structure of the FRP tendon according to the example. 1...FRP rod, 2...outer tube, 3...〓
Hole, 4...Crack, 5...Hell wedge, 6...Adhesive resin, 7...Edge cutting film.

Claims (1)

[Scope of utility model registration request] The end of the fiber-reinforced synthetic resin tendon, which has been split into a dovetail shape by inserting a hell wedge into the dovetail-shaped hole provided in the outer tube of the fixing device, is inserted into the center of the tension material. A fiber-reinforced fiber reinforced material characterized by having a hardened adhesive resin filled between the cracks, at the interface with the hole, and at the interface with the Hell Wedge, and an edge-cutting film provided at the bottom of the hole. Anchor structure made of synthetic resin tension material.