JPH11324223A - Reinforcing/repairing fiber sheet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To surely execute anchoring of ends of a fiber sheet for reinforcing and repairing a construction building. SOLUTION: A reinforcing/repairing fiber sheet is constituted of a belt fiber sheet section 1 formed by arranging high strength fibers in the longitudinal direction in resin, a transition section 3 extending while converging the high strength fibers in the sheet 1 by specific length from at least one end of the fiber sheet 1 and a rod section 2 processed in the required number of rods by binding the high strength fibers by the specific length from the end section of the transition section 3.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement in a fiber sheet used for reinforcing and repairing various structures.

[0002]

2. Description of the Related Art A fiber sheet or fiber tape obtained by molding a high-strength fiber into a belt-like sheet or film with a resin, or a fiber cable obtained by processing a high-strength fiber into a linear shape is used as a material for reinforcing and repairing various structures. Have been. For example, strips made of high-strength fibers, such as carbon fibers and aramid fibers, arranged in one or two directions in epoxy resin have attracted attention as reinforcing materials for bridge piers and bridge girders.
The fiber processed into a cable or formed into a line in a resin is used as a PC tendon, an anchor, a concrete reinforcing material, or the like.

[0003] Such fiber reinforced plastics (FR)
P) has begun to be used in the construction field, but in actual use, it must be devised so that each feature contributes most to improving the strength of the structure.

For example, in the case of applying the above-mentioned fiber sheet or fiber tape (hereinafter simply referred to as fiber sheet) to reinforcement of a pier base, a method of winding a fiber sheet in a circumferential direction of a pier, There is a method in which fiber sheets are arranged in parallel in the axial direction (longitudinal direction) of the pier and attached. In the former, shear reinforcement of the pier is provided, and in the latter, toughness reinforcement. In either case, the concrete surface is treated with or without a foundation treatment (shaping or sanding), and is usually subbed with a resin impregnated with a fiber sheet, for example, the same resin as epoxy resin. This is done by applying a fiber sheet and then overcoating with the same resin. When this is done, a protective mortar finish is usually performed on it.

[0005] In the former case of shear reinforcement, the required area can be covered by spirally winding and winding (or unwinding) a continuous-length fiber sheet. That is, since the fibrous sheet is continuous, no special measures are required for its locking at the beginning and end. However, in the latter case of toughening, the fiber sheets cut to a certain length are attached side by side in the vertical direction (in the case of girders) in the case of a bridge pier to cover the required area. The end of each fiber sheet is a free end. If this free end remains, the degree of contribution to toughness reinforcement at that portion will be low, so a special device is required to lock this end.

When a pier stands on a foundation having a horizontal surface and the fiber sheet of a fixed length is vertically stuck to the pier surface in a vertical direction, for example, the lower end is locked as follows. Four methods have been proposed.

(1) Iron plate bonding method: The lower end of the fiber sheet is adhered with the lower end of the fiber sheet aligned slightly above the base surface, and the lower end of the fiber sheet is pressed down with an iron plate having an L portion or a flange below, and placed on the base surface. An anchor bolt is driven into the foundation vertically to the L portion or the flange portion to fix the iron plate. As a result, shear reinforcement and toughness reinforcement between the foundation and the pier are provided.

(2) Iron plate bonding and anchor bolt fixing method: The iron plate bonding method described in (1) above is performed, and the anchor bolts are horizontally inserted into the piers with respect to the iron plate at the lower end of the fiber sheet. Type in. By increasing the number of anchor bolts to be driven into the pier, the bonding between the fiber sheet and the iron plate is strengthened, so that the shear reinforcement and toughness reinforcement between the foundation and the pier are further improved.

(3) Iron plate / anchor bolt fixing method: The lower end of the fiber sheet is protruded from the lowermost end of the pier, and the protruding portion is attached to the foundation surface by changing the direction by 90 °.
An iron plate is placed on the end of the fiber sheet attached to the surface of the foundation, and an anchor bolt is driven into the foundation from above the iron plate. In this case, in order to prevent the fiber sheet from changing its direction from the pier to the foundation surface to form a radius, and to prevent a cavity from being formed behind the radius, a mortar should be applied to the pier rooting portion in advance by mortar. Keep going. This is the same as filling the mortar in the cavity on the back side of the radius portion. The advantage of this method is that it can be connected with a continuous fiber sheet between the foundation and the pier.

(4) Anchoring method for iron plate and anchor bolt in root-wound concrete: Align the lower end of the fiber sheet with the lowest part of the pier, wrap the iron plate over it, and drive the anchor bolt on the iron plate into the pier. Press the lower end of the fiber sheet with an iron plate. Then, formwork is built on the foundation so as to surround the pier, and concrete is cast to form a rooted concrete. As a result, the lower end of the fiber sheet is fixed by the iron plate and the anchor bolts in the wrapped concrete, and the wrapped concrete also contributes to the strength reinforcement.

On the other hand, when a fiber sheet is stuck on the back side of the bridge girder in the axial direction to reinforce the toughness of the bridge girder, a large number of fiber sheets cut to a predetermined length are aligned in parallel at respective ends. Attachment is performed. In this case, where it is difficult to lock the end of each fiber sheet, the fiber sheet is left attached or another fiber sheet is covered so as to cover the end. Are crossed in a direction orthogonal to each other, and a method of overlapping and pasting is adopted. In any case, in this case, the adhesive strength between the fiber sheet and the concrete surface must be sufficient.

[0012]

As described above, when a fibrous sheet is adhered in the axial direction of a structure to reinforce the toughness of the structure, both ends of the fibrous sheet become free ends interrupted there. However, no reinforcement is made at the discontinuous portion of the fiber sheet, and there is a risk that stress concentration may occur at the free end portion. For this reason, the above (1) to (4)
Although such fixing methods have been devised, both use an iron plate and anchor bolts, and therefore, there is a problem that the operation becomes complicated and the characteristics of the fiber sheet cannot be fully utilized. An object of the present invention is to solve such a problem.

[0013]

According to the present invention, as a fiber sheet material which solves the above-mentioned problems, according to the present invention, a high-strength fiber is longitudinally oriented in a resin at an end of a strip-shaped fiber sheet. Reinforcement by providing a plurality of rods formed by bundling the high-strength fibers in the longitudinal direction extending from the end of the sheet
A repair fiber sheet is provided.

Further, according to the present invention, a strip-shaped fiber sheet portion in which high-strength fibers are oriented in a resin in a longitudinal direction, and a predetermined length from at least one end of the fiber sheet in the sheet. And a rod portion formed by bundling the high-strength fibers by a predetermined length from the end of the transition portion and processing the rod into a required number of rods. A repair fiber sheet is provided.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The fiber sheet of the present invention has a rod end, and is characterized in that both the sheet part and the rod part are connected by continuous high-strength fibers. This makes it possible to fix the end of the fiber sheet to the structure in the same manner as in a normal cable end fixing method.

FIG. 1 shows a typical embodiment of the fiber sheet of the present invention. As shown in FIG. 1, this fiber sheet is composed of a rod-shaped part 2 in which fibers extending from the sheet 1 are bundled at the end of a strip-shaped fiber sheet 1 in which high-strength fibers are oriented in a longitudinal direction in a resin. Are formed in a plurality.

The fiber sheet 1 is made of high-strength fibers such as aramid fibers (fibers made of poly-P-phenylene terephthalamide), carbon fibers, glass fibers, etc., in the longitudinal direction, similar to the conventional ones. It is made of a resin such as an epoxy resin or a vinyl ester resin. A bidirectional fiber sheet having similar high-strength fibers in a direction orthogonal to the longitudinal direction may be used. The thickness and width of the fiber sheet 1 can be various as in the case of the conventional product, and an appropriate size and shape may be selected according to the location to be reinforced and repaired. For convenience, a fiber sheet using aramid fiber as the high-strength fiber and an epoxy resin as the binder resin will be described below as an example, but the types of the high-strength fiber and the binder resin are not limited thereto.

Each aramid fiber oriented in the longitudinal direction in the fiber sheet 1 is extended from the epoxy resin in the sheet at the end of the sheet, and in the example of FIG. It is. Each rod 2 is hardened with the same epoxy resin as the sheet. More specifically, the aramid fibers divided into three groups are further divided into necessary bundles, and each bundle is formed into a strand (strand) and fixed with epoxy resin to form one rod portion 2. Have been.

There is an intermediate between the fiber sheet 1 and the rod portion 2 where the fiber bundle converges from the sheet end toward the rod portion 2. It will be named transition part.
The transition portion 3 is also hardened with an epoxy resin, but in some cases, the aramid fiber may be left exposed, and this portion may be a soft band. In any case, when a tensile stress is applied to the rod portion 2 in the axial direction, there is no sharp gradient change at the boundary between the transition portion 3 and the rod portion 2 so that the aramid fiber does not disperse at the boundary. At the same time, it is preferable that the rod portion 2 is made of a strand or a braid and solidified with resin. If necessary, a buckle may be fitted to the boundary.

As described above, the fiber sheet of the present invention comprises a band-shaped fiber sheet portion 1 in which high-strength fibers are oriented in a resin in a longitudinal direction, and a predetermined length from at least one end of the fiber sheet 1. A transition section 3 from which the high-strength fibers in the sheet converge and extend, and a rod formed by bundling the high-strength fibers by a predetermined length from the end of the transition section 3 and processing the required number of rods. Part 2.

This fiber sheet is used for repair / reinforcement of the structure by attaching the fiber sheet portion 1 to the structure using a bonding resin, for example, an epoxy resin, similarly to the conventional fiber sheet. Since it has a rod part 2 at the end,
In particular, end fixing in the case where toughening is performed by sticking in the axial direction of the structure can be easily and reliably performed. For example, the fixing of the lower end when the fiber sheets of the present invention are stuck on the surface of the pier in the vertical direction can be performed as shown in FIG.

FIG. 2 (a) shows a schematic cross section of a pier half when the pier 4 stands on the foundation 5, and FIG. 2 (b) shows a schematic side view of the pier. The fiber sheet portions 1 of the fiber sheet of the invention are stuck in a vertical direction, the rod portions 2 at each lower end are buried in a foundation 5, and another fiber sheet 6 is placed on the transition portion 3 in a horizontal direction. It is wrapped around.

That is, as in the prior art, the same impregnating resin as the fiber sheet, for example, the same kind of resin as the epoxy resin, is used for undercoating.
The fiber sheet part 1 is stuck on it without any gap in the vertical direction. The rod part 2 is inserted into a bolt hole previously drilled in the foundation 5, and a fixing agent (usually cement paste) is inserted in the same manner as in the rock bolt method. Or mortar) is fixed in the bolt hole. Then, a fiber sheet (or tape) 6 is wound around the transition portion 3 between the fiber sheet portion 1 and the rod portion 2 in the circumferential direction of the pier. Then, if necessary, the same epoxy resin is overcoated on the entire surface of the fiber sheet, and the mortar finish is applied to complete the construction.

At the upper end of each fiber sheet, the rod sections 2 are not provided, and the end faces of the sheets are aligned at the uppermost end of the pier as in the prior art. However, in some cases, the same method as the above-described method of fixing to the foundation can be applied to the upper structure by providing the rod portion 2. In addition, a fixing device (for example, an iron plate wound in the circumferential direction of the pier) for fixing each rod portion 2 is supported from the upper structure, and the end portion of the rod portion 2 is connected to a known cable end. It is also possible to adopt a method of joining using the same fixing device as the above.

FIG. 3 shows an example in which the fiber sheet of the present invention is stuck on the back surface of the bridge girder 7 in the axial direction of the girder to reinforce the toughness of the bridge girder.
The rod portions 2 are inserted into bolt holes previously drilled in the girder support structure 8 (pier), and fixed in the bolt holes using a fixing agent. Then, another fiber sheet 9 (or tape) is attached to the transition portion 3 in a direction orthogonal to the fiber sheet. Although not visible in FIG. 3, the other end of the fiber sheet portion 1 is also fixed with the rod portion 2 to the other girder support structure in the same manner as shown, and the other fiber sheet portion is similarly fixed to the transition portion 3. Or attach the tape in a direction perpendicular to it. Then, if necessary, the same epoxy resin is overcoated on the entire surface of the fiber sheet, and the mortar finish is applied to complete the construction.

The columns and beams of general buildings are not limited to the above examples.
The fiber sheet of the present invention can fix the rod portion 2 to the structure also for slabs, walls, and the like.

[0027]

As described above, since the end of the fiber sheet of the present invention can be fixed to the structure by the rod portion, the fiber sheet of the present invention is not affected by the tensile stress or bending stress in the axial direction even at the end of the sheet. This has an excellent effect that the reinforcement is sufficiently performed. In addition, the anchoring at the rod end is as easy as the anchoring at the cable end, so the workability is good, and the fiber sheet for reinforcing and repairing various structures has a practical effect not found in the past. Play.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an example of an end structure of a fiber sheet of the present invention.

FIG. 2 is a diagram showing a state of a lower part of a pier showing an example of toughening a pier using a fiber sheet according to the present invention, and FIG. 2 (a) is a schematic sectional view of the pier half body, FIG. Is a side view of the pier half body.

FIG. 3 is a partial cross-sectional view showing an example of toughening a bridge girder using a fiber sheet according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Fiber sheet part 2 Rod part 3 Transition part 4 Bridge pier 5 Foundation 6 Other fiber sheet stuck on transition part 7 Bridge girder 8 Bridge girder support structure 9 Other fiber sheet stuck on transition part

Claims (5)

[Claims] 1. A plurality of long-strength fibers formed by bundling the longitudinal high-strength fibers protruding from the end of the sheet at the end of a strip-shaped fiber sheet in which high-strength fibers are oriented in a longitudinal direction in a resin. A fiber sheet for reinforcement and repair with a rod. 2. A band-like fiber sheet portion in which high-strength fibers are oriented in a resin in a longitudinal direction, and the high-strength fibers in the sheet converge by a predetermined length from at least one end of the fiber sheet. A reinforcing and repairing fiber sheet comprising: a transition portion extending and extending; and a rod portion formed by bundling the high-strength fibers by a predetermined length from an end portion of the transition portion and processing into a required number of rods. 3. The reinforcing / repairing fiber sheet having a rod portion according to claim 1, wherein the high-strength fiber is an aramid fiber, a carbon fiber, or a glass fiber. 4. The reinforcing / repairing fiber sheet according to claim 1, wherein the sheet contains, in addition to the high-strength fiber oriented in the longitudinal direction, high-strength fiber oriented in a direction perpendicular to the longitudinal direction. . 5. The rod portion is formed by forming a bundle of high-strength fibers into a more linear or braided shape and fixing the bundle with a resin.
5. The fiber sheet for reinforcement and repair according to 2, 3, or 4.