JP5467950B2 - Structural reinforcement method - Google Patents

Description

  The present invention relates to a structure reinforcing method in which a band-shaped aramid fiber sheet is wound around a structure to reinforce the structure.

  Conventionally, a structure (for example, concrete columnar body) is reinforced by winding an aramid fiber sheet, and various reinforcing methods have been proposed (for example, refer to Patent Document 1).

  FIG. 7 is a schematic diagram showing an example of a conventional technique for reinforcing a structure. An operator wrapped an aramid fiber sheet 25 around the structure 10 using an adhesive resin (not shown).

JP 2008-214993 A

  By the way, in the case of a thin concrete column like a power pole, it can be reinforced relatively easily by the method shown in FIG. 7, but in the case of a large concrete structure such as a railway or a road pier, the winding work is not easy. It took a long time, and there was a possibility that the winding position of the aramid fiber sheet was shifted during the operation.

  The object of the present invention is to provide a method for reinforcing a structure, which can eliminate or reduce the above-mentioned problems.

The invention according to claim 1 is illustrated in FIGS. 1 (a) to (c), and a belt-like aramid fiber sheet (5) is wound around the structure (1) to reinforce the structure (1). In the structure reinforcement method,
A resin layer forming step (see FIG. 1 (a)) in which an adhesive resin is applied to the surface (1a) of the structure (1) to form an adhesive resin layer (2);
The mold member (3) is pressed against the surface (2a) of the adhesive resin layer (2) until the adhesive resin layer (2) is cured, and extends in the first direction (X) which is one direction. A groove forming step for forming the groove (4) (see FIG. 1 (b)),
While the adhesive resin layer (2) is cured, the aramid fiber sheet is bonded while at least a part of the longitudinal direction (XL) of the aramid fiber sheet (5) is fitted in the groove (4). A sheet winding step of winding (5) around the structure (1) (see FIG. 1 (c)).

In the invention according to claim 2, in the invention according to claim 1, when the direction (Y) orthogonal to the first direction (X) is defined as "second direction",
The adhesive resin has a viscosity that can maintain the shape of the groove (4) and can hold the aramid fiber sheet (5) so that the aramid fiber sheet (5) does not shift in the second direction (Y). It is characterized by being.

The invention according to claim 3 is the invention according to claim 1 or 2, wherein the bottom surface of the groove (4) (FIG. 2 (a)
Is a substantially smooth surface along the surface (1a) of the structure (1),
Width of the groove (4) (reference numeral W ₁ in FIG. 1 (c)) is characterized by substantially equal to the width (W ₂₎ of the aramid fiber sheet (5).

  The invention according to claim 4 is the invention according to claim 2 or 3, characterized in that the adhesive resin is an underwater curable adhesive resin.

The invention according to claim 5 is the invention according to any one of claims 1 to 4, wherein in the groove portion forming step, the second portion (Y) that is perpendicular to the first direction is separated. Forming a plurality of grooves (4) in the state
In the sheet winding step, a plurality of aramid fiber sheets (see 5A, 5B, 5C, and 5D in FIG. 5) are fitted into the plurality of groove portions (4), respectively, and separated in the second direction (Y). A strip of aramid fiber sheets (5A, 5B, 5C, 5D) is wound around the structure (1).

  Note that the numbers in parentheses are for the sake of convenience indicating the corresponding elements in the drawings, and therefore the present description is not limited to the descriptions on the drawings.

  According to the invention which concerns on Claim 1 and 2, since the aramid fiber sheet is hold | maintained in the state engage | inserted in the said groove part, the situation where the position of an aramid fiber sheet shifts can be reduced or avoided. Further, the burden of holding the sheet while the worker is winding the aramid fiber sheet can be reduced, and workability can be improved accordingly. Furthermore, according to the present invention, since the adhesive resin having a high viscosity is used, even if it is applied to the pier portion submerged in water, it is difficult to flow down, and the pier portion can be reinforced.

  According to the invention of claim 3, even if the aramid fiber sheet is strongly pressed locally, the aramid fiber sheet is prevented from being restored, and a local gap between the aramid fiber sheet and the adhesive resin layer is generated. Can be prevented to prevent a decrease in adhesive strength.

  According to the invention which concerns on Claim 4, the part which is the bridge pier standing in the river etc. and is submerged can be reinforced.

  According to the invention which concerns on Claim 5, a structure can be reinforced more strongly by the number which wound the aramid fiber sheet.

FIG. 1 is a perspective view schematically showing each step of a method for reinforcing a structure according to the present invention. FIG. 2 is a cross-sectional view showing the shape and the like of the groove. FIG. 3 is a cross-sectional view showing an example of a conventional bonding state of an aramid fiber sheet. FIG. 4 is a perspective view showing another example of the configuration of the aramid fiber sheet. FIG. 5 is a perspective view showing an example of a wound state of an aramid fiber sheet. FIG. 6 is a cross-sectional view showing a state in which a plurality of aramid fiber sheets are wound. FIG. 7 is a schematic diagram showing an example of a conventional technique for a structure reinforcement method.

  Hereinafter, embodiments of the present invention will be described with reference to FIGS. 1 to 6.

  The structure reinforcing method according to the present invention is a method of reinforcing a structure by winding a band-shaped aramid fiber sheet around the structure. Examples of structures reinforced by this method include concrete structures such as bridge piers.

The method of reinforcing a structure according to the present invention is as follows.
A resin layer forming step of forming an adhesive resin layer 2 by applying an adhesive resin (for bonding the aramid fiber sheet 5 to the surface 1a of the structure 1) on the surface 1a of the structure 1 (FIG. 1 (a)) See)
-The mold member 3 is pressed against the surface 2a of the adhesive resin layer 2 until the adhesive resin layer 2 is cured, and the first direction X (hereinafter referred to as "first direction X") A groove portion forming step (see FIG. 5B) for forming a groove portion 4 extending in a direction perpendicular to X as a “second direction Y”;
-While the adhesive resin layer 2 is cured, the aramid fiber sheet 5 is wound around the structure 1 while adhering at least a part of the longitudinal direction XL of the aramid fiber sheet 5 in the groove 4. Sheet winding process;
It has. The extending direction of the groove 4 in FIG. 1B (that is, the first direction X) is a horizontal direction, but of course not limited to this, it may be a vertical direction. The direction may be Further, the above-mentioned adhesive resin can maintain the shape of the groove 4 and holds the aramid fiber sheet 5 so that the position of the aramid fiber sheet 5 does not shift in the second direction Y (or the opposite direction). It must have a viscosity as high as possible. Furthermore, as the adhesive resin, it is preferable to use a material that does not cure until a series of steps is completed. For example, an underwater curable adhesive resin (for example, trade name grip bond manufactured by Sumitomo Rubber Industries, Ltd.) may be used. In the case of using an underwater curing type adhesive resin, it is possible to reinforce a submerged portion of a bridge pier standing in a river or the like.

  According to the present invention, since the aramid fiber sheet 5 is held in a state of being fitted into the groove portion 4, a situation in which the position of the aramid fiber sheet 5 is shifted can be reduced or avoided. In addition, the burden of holding the sheet 5 while the worker is winding the aramid fiber sheet 5 can be reduced, and workability can be improved correspondingly. Furthermore, according to the present invention, since the adhesive resin having a high viscosity is used, even if it is applied to the pier portion submerged in water, it is difficult to flow down, and the pier portion can be reinforced.

In this case, the bottom surface of the groove 4 (the surface indicated by reference numeral 4b in FIG. 2 (a)) is a substantially smooth surface along the surface 1a of the structure 1, and the width of the groove 4 (reference numeral in FIG. 1 (c)). W ₁ ) is preferably set to be substantially equal to the width W ₂ of the aramid fiber sheet 5. FIG. 3 (a) shows an adhesive resin layer without forming such a groove portion 4.
When the aramid fiber sheet 5 is pressed locally and strongly as shown by the reference numeral F1 in FIG. 11A when it is formed smoothly as shown by the reference numeral 12 in (b), the aramid fiber sheet 5 itself has. The same figure (b) by the restoring force (the stiffness of the aramid fiber sheet 5)
As shown by reference numeral F2, the aramid fiber sheet 5 tries to return to an appropriate state, and a gap is locally generated between the aramid fiber sheet 5 and the adhesive resin layer 12, and the adhesive strength is reduced accordingly. There is a fear. In contrast, in the present invention, FIG.
As shown in FIG. 3, the three surfaces of the aramid fiber sheet 5 (that is, the three surfaces indicated by reference numerals 5a, 5b, and 5c) are the three surfaces of the groove portion 4 (that is, the three surfaces indicated by reference numerals 4a, 4b, and 4c) Since it is bonded and held, the same figure (b)
Even if the aramid fiber sheet 5 is strongly pressed locally as indicated by reference numeral F1, the restoration of the aramid fiber sheet 5 is prevented, and the local gap between the aramid fiber sheet 5 and the adhesive resin layer 2 is prevented. Generation | occurrence | production of this can be blocked | prevented and the fall of adhesive strength can be prevented.

In addition, it is preferable to press the aramid fiber sheet 5 so that a gap does not occur between the bottom surface 4b of the groove portion 4, and for that purpose, the width W2 of the sheet 5 is preferably about ₁₀ to 50 mm. According to the present inventors, if the width W2 of the sheet 5 is about ₁₀ to 50 mm, even if the adhesive resin layer 2 has a high viscosity (for example, a product name grip manufactured by Sumitomo Rubber Industries, Ltd.). It was found that the aramid fiber sheet 5 can be sufficiently pressed against the bottom surface 4b by the operator's force (even when reinforcing the submerged pier portion using a bond).

  By the way, in order to increase the adhesive strength of the aramid fiber sheet 5, the adhesive resin layer 2 and the groove 4 are formed over the entire periphery of the structure 1, and the aramid fiber sheet 5 is bonded over the entire periphery of the structure 1. However, it is not excluded from the scope of the present invention that the adhesive resin layer 2 and the groove 4 are partially formed instead of the entire circumference of the structure 1.

Further, also good as aramid fiber sheet 5 is one of the above, as illustrated in FIG. 4, a short aramid fiber sheet piece 5A _1, 5A 2, 5A _3, so that wound _... the structure 1 by connecting a It is good to make it. In that case,
Adhesion of the aramid fiber sheet piece 5A 1 to the structure ₁ Adhesion of the aramid fiber sheet piece 5A ₂ to the structure 1 Adhesion of the aramid fiber sheet piece 5A ₃ to the structure 1 may be sequentially performed.

Further, a plate material or the like can be used as the mold member 3 described above, but the aramid fiber sheet 5 may be impregnated with a resin to form a plate-like fiber reinforced plastic (FRP), which may also be used as a mold member. . In that case, the fiber reinforced plastic is embedded in the adhesive resin layer 2 in a state where the groove 4 is not formed,
-Formation of the groove part 4 (groove part forming step);
-Winding of fiber reinforced plastic 5 (sheet winding process);
Will be performed simultaneously.

Furthermore, in the groove forming step, a plurality of grooves 4 are formed in a state of being separated in the second direction Y, and in the sheet winding step, aramid fiber sheets (FIG. 5 ( a) of 5a, 5B, 5C, 5D), and a plurality of aramid fiber sheets separated in the second direction Y may be wound around the structure. In such a case, the structure 1 can be reinforced more strongly by the number of wound aramid fiber sheets. In the case of winding a plurality of aramid fiber sheets around the structure in such a manner, the same figure (b)
As shown in FIG. 4, it is preferable to connect the plurality of aramid fiber sheets in advance with warp yarns 6 so as to form a sled.

When a plurality of aramid fiber sheets are wound as shown by reference numerals 5A, 5B, 5C, 5D in FIG. 5 (a), the gaps between the aramid fiber sheets 5A, 5B, 5C, 5D (reference numeral d in FIG. 6). It is preferable that the dimension of the portion indicated by (3) be 3 mm or more. In such a case, when each aramid fiber sheet 5A, 5B, 5C, 5D is pressed against the adhesive resin layer 2, it is between the aramid fiber sheets 5A, 5B, 5C, 5D and the groove bottom surface 4b. Air and water can escape from the gap d. That is, each aramid fiber sheets 5A, 5B, 5C, 5D and areas to bond the (portion indicated by reference numeral _{W 1)} by providing alternating with gaps (indicated by reference numeral d), each aramid fiber sheets 5A, 5B, It is preferable to improve the adhesive strength by allowing air and water between 5C and 5D and the groove bottom surface 4b to escape easily.

DESCRIPTION OF SYMBOLS 1 Structure 1a Surface of structure 2 Adhesive resin layer 2a Surface of adhesive resin layer 3 Mold member 4 Groove part 5 Aramid fiber sheet X 1st direction XL Longitudinal direction of XL aramid fiber sheet Y 2nd direction

Claims (5)

In a reinforcing method for a structure, a belt-shaped aramid fiber sheet is wound around the structure to reinforce the structure,
A resin layer forming step of forming an adhesive resin layer by applying an adhesive resin to the surface of the structure;
A groove forming step of pressing a mold member against the surface of the adhesive resin layer until the adhesive resin layer is cured to form a groove extending in a first direction which is one direction;
Until the adhesive resin layer is cured, a sheet winding step of winding the aramid fiber sheet around the structure while adhering at least a part of the longitudinal direction of the aramid fiber sheet fitted in the groove,
A structure reinforcing method characterized by comprising: When the direction perpendicular to the first direction is the “second direction”,
The adhesive resin has a viscosity that can maintain the shape of the groove and can hold the aramid fiber sheet so that the aramid fiber sheet does not shift in the second direction.
The method for reinforcing a structure according to claim 1, wherein: The bottom surface of the groove is a substantially smooth surface along the surface of the structure,
The width of the groove is substantially equal to the width of the aramid fiber sheet,
The structure reinforcing method according to claim 1 or 2, wherein the structure is reinforced. The adhesive resin is an underwater curable adhesive resin.
The method for reinforcing a structure according to claim 2 or 3, wherein the structure is reinforced. In the groove forming step, forming a plurality of grooves in a state of being separated in a second direction which is a direction orthogonal to the first direction,
In the sheet winding step, an aramid fiber sheet is fitted into each of the plurality of groove portions, and the plurality of aramid fiber sheets in a state separated in the second direction are wound around the structure.
The structure reinforcing method according to any one of claims 1 to 4, wherein the structure is reinforced.

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