JPH08333715A - Reinforcing method of concrete structure base - Google Patents

Abstract

PURPOSE: To bring a reinforced effect through a fiber reinforced sheet into full play by preventing any possible separation of this sheet impregnated with matrix resin executed on the surface of a concrete structure base with an angular part where both horizontal and vertical parts are crossed with each other. CONSTITUTION: In an angular part 13 of a concrete structure base 10, a groove 14 is installed in the cross direction of a vertical part 12 to a horizontal part 11, and a fiber reinforced sheet 1 is set up along a surface of the vertical part 12. The lower end is inserted into the groove 14, and the fiber reinforced sheet 1 is stuck to the surface of the vertical part 12 by means of matrix resin inpregnated in a reinforced fiber of the fiber reinforced sheet. In addition, resign is poured into the groove 14, and execution of this sheet 1 to the vertical part 12 is completed. In succession, the inpregnated resin and another resin poured into the groove 14 both are hardened. With this constitution, since a lower end of the fiber reinforced sheet 1 secured by resign in the groove 14 becomes an anchor, anchoring strength of the fiber reinforced sheet 1 is sharply heightened, any possible separation of the sheet 1 from the surface of the vertical part 14 due to each action of axial force and bending moment is thus preventable.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a base of a concrete structure by attaching a reinforcing fiber sheet having reinforcing fibers to the surface of the base of a concrete structure, impregnating the reinforcing fiber with a matrix resin and curing the resin. On how to reinforce.

[0002]

2. Description of the Related Art Recently, for example, bridge piers of concrete structures such as bridges and elevated roads have been reinforced with fiber reinforced plastics or repaired. The applicant of the present invention has filed Japanese Patent Application Laid-Open Nos. 3-222734 and 3-2.
As described in Japanese Patent No. 4901, a reinforced fiber sheet for reinforcement that can be reinforced at a reinforcement site with good workability and has a high strength improvement by reinforcement has been proposed. Figure 6
The outline of this reinforcing fiber sheet is shown in FIG.

The reinforcing fiber sheet 1 has reinforcing fibers 4 arranged in one direction on a support 2 with an adhesive layer 3 interposed therebetween. In the reinforcing fiber sheet 1, the reinforcing fiber 4 is impregnated with the matrix resin at a reinforcing site such as a bridge or an elevated road, and is applied to the surface to be reinforced, and then the resin is cured.

The reinforcing fiber sheet 1 is constructed by impregnating the reinforcing fibers 4 with a matrix resin and then pasting the reinforcing fiber sheet 1 on the reinforcing surface, or by applying the matrix resin on the reinforcing surface. Is adhered and pressed from above to impregnate the reinforcing resin with the matrix resin. Further, in order to improve the impregnation property of the matrix resin into the reinforcing fiber, the support 2 of the reinforcing fiber sheet 1 is made of glass fiber cloth or the like.
Alternatively, the matrix resin may be applied from the side of the support 2 and the reinforcing resin may be impregnated with the matrix resin after being attached to the reinforcing surface.

[0005]

When reinforcing the base portion of a concrete structure such as a chimney, as shown in FIG. 7, it is necessary to have a corner portion 13 where a horizontal portion 11 and a vertical portion 12 intersect each other. In the base 10, the reinforcing fiber sheet 1
Was bent at the corner portion 13, and was attached along the lateral direction portion 11 and the longitudinal direction portion 12 and applied to cure the matrix resin impregnated in the reinforcing fiber.

However, in such a construction method, the base 10
The fixing strength of the reinforcing fiber sheet 1 on the surface is low, and the reinforcing fiber sheet 1 is easily peeled off from the surface of the lateral direction portion 11 due to the axial force P and the moment M acting on the longitudinal direction portion 12 and impregnated with the matrix resin. However, there is a problem that the reinforcing and strengthening by the reinforcing fiber sheet 1 cannot be sufficiently exerted.

An object of the present invention is to prevent peeling of a reinforcing fiber sheet impregnated with a matrix resin, which is applied to the surface of the base of a concrete structure, so that the reinforcing effect of the reinforcing fiber sheet can be sufficiently exhibited. It is to provide a method of reinforcing a concrete structure base.

[0008]

The above object can be achieved by the reinforcing method according to the present invention. In summary, the present invention attaches a reinforcing fiber sheet having reinforcing fibers to the surface of a concrete structure base having corners where longitudinal parts intersect with transverse parts and cures the matrix resin impregnated with the reinforcing fibers. In the method of reinforcing the base by doing,
A groove is formed in the lateral direction at the corner of the base, and the lower end of the reinforcing fiber sheet arranged along the surface of the longitudinal direction is inserted into the groove, and the groove is filled with resin to cure. It is a method of reinforcing a concrete structure base, which is characterized by:

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is an explanatory view showing the reinforcing method of the present invention. As shown in FIG. 1, in the corner portion 13 of the concrete structure base portion 10, a groove 14 is formed in the width direction of the vertical portion 12 with respect to the horizontal portion 11. The reinforcing fiber sheet 1 is arranged along the surface of the longitudinal portion 12, and the lower end portion thereof is provided with the groove 14
Insert inside. As shown in FIG. 6, the reinforcing fiber sheet 1 has reinforcing fibers 4 arranged in one direction on a support 2 with an adhesive layer 3 interposed therebetween. The reinforcing fiber sheet 1 has the longitudinal direction of the reinforcing fibers arranged in the longitudinal direction 12.

If the reinforcing fibers have been already impregnated with resin before the reinforcing fiber sheet 1 is placed along the reinforcing fiber sheet 1, the reinforcing fiber sheet 1 is directly attached to the surface of the longitudinal portion 12 and is not impregnated with the matrix resin. Resin-impregnated reinforcing fiber 1
Paste. Further, resin is poured into the groove 14. In this way, when the reinforcing fiber sheet 1 is applied to the surface of the longitudinal portion 12 of the base 10, the matrix resin impregnated with the reinforcing fibers and the resin poured into the groove 14 are cured.

According to this construction method, since the lower end of the reinforcing fiber sheet 1 inserted into the groove 14 and fixed with the resin serves as an anchor, the reinforcing fiber sheet 1 is fixed on the surface of the longitudinal portion 12 of the sheet. Strength can be significantly increased, and even if axial force and bending moment act on the longitudinal portion 12, the reinforcing fiber sheet 1
It is possible to prevent peeling from the surface of the vertical direction portion 12 and sufficiently exert the reinforcing and curing by the reinforcing fiber sheet 1.

In order to exert the anchor effect on the lower end of the reinforcing fiber sheet 1 inserted in the groove 14, the insertion length a of the lower end into the groove 14 must be at least 5 mm.
The insertion length a is as the reinforcing fiber sheet 1 becomes longer,
It can be up to 1000 mm. The depth c of the groove 14 is set to an insertion length a of 5 to 1000 mm or a margin thereof, for example, 1 to 50 mm. The width d of the groove 14 can be set in the range of 10 to 500 mm in the normal work of constructing the reinforcing fiber sheet 1 with five or less sheets from the viewpoint of workability in constructing the reinforcing fiber sheet 1. In consideration of workability of construction of the reinforcing fiber sheet 1, the length e of the groove 12 is at least 2 in the width b of the reinforcing fiber sheet 1.
The amount added about 0 mm is preferable, and the maximum width is b + 1000.
It is possible up to mm.

As the reinforcing fiber of the reinforcing fiber sheet 1, various kinds such as carbon fiber, graphite fiber, glass fiber, boron fiber, steel fiber, aramid fiber, polyester fiber and polyethylene fiber can be used.

As the matrix resin with which the reinforcing fibers are impregnated, various room temperature curable resins such as epoxy resin, unsaturated polyester resin and polyurethane resin can be used. As the resin with which the groove 14 is filled, the same resin as the matrix resin or another type of room temperature curable resin can be used.

The following experiments were conducted to confirm the effects of the present invention.

As shown in FIG. 3, usually, Portland cement (Fc = 230 kgf / cm ² ) is used and the reinforcing bar 1
A concrete block 16 having an inverted T-shape in section containing 5 was prepared, and grooves 17 were provided in the widthwise direction of the vertical direction portion with respect to the lateral direction portions of the corners on both sides thereof. The thickness of the block 16 is 60 m
m, the width of the lateral portion is 120 mm, the height is 70 mm, and the longitudinal portion containing the reinforcing bar 15 is 40 mm in width and 8 in length.
It is 0 mm. The groove 17 has a depth of 50 mm and a width of 20 mm.
And

On the surfaces of the longitudinal portions on both sides of the block 16,
1 carbon fiber sheet 18 with a width of 60 mm and a length of 120 mm
Layers were applied and used as test pieces. As the carbon fiber sheet 18, FTS-C1-20 manufactured by Tonen K.K. was used. The matrix resin impregnated in the carbon fiber and the resin put in the groove 17 were epoxy resins, and FR-E3P manufactured by Tonen K.K. was used.
The length of insertion of the carbon fiber sheet into the groove 17 was 40 mm.

For comparison, as shown in FIG. 4, a carbon fiber sheet 18 having a width of 60 mm and a length of 100 mm or 120 mm is provided on both sides of the concrete block 16 having the same size as described above from the longitudinal direction to the lateral direction. One layer was constructed using the same matrix resin. In the construction, the surface of the block 16 is sanded in advance,
Tonen's primer FP / NS was applied. The length (fixing length) of the carbon fiber sheet 18 in the lateral direction of the block 16 was 20 mm when the length of the carbon fiber sheet 18 was 100 mm and 40 mm when it was 120 mm.

As shown in FIG. 5, the test pieces of the present invention and the comparative example prepared as described above were fixed with bolts 19 between the upper and lower jigs 20, 20 of the Instron tester,
A tensile test was performed at a crosshead speed of 1 mm / sec to determine the maximum strength of the concrete block 16 at that time. Table 1 shows the results.

[0020]

[Table 1]

As shown in Table 1, according to the method of the present invention, it was confirmed that the carbon fiber sheet was prevented from peeling and the reinforcing effect by the carbon fiber sheet impregnated with the matrix resin was sufficiently exerted. Was done.

[0022]

As described above, according to the method of the present invention, the reinforcement is formed by forming the groove in the lateral direction at the corner of the concrete structure base and arranging it along the surface of the longitudinal direction of the base. By inserting the lower end of the fiber sheet into the groove and filling the groove with resin so as to cure, it is possible to construct a reinforcing fiber sheet with high fixing strength on the surface of the longitudinal portion of the base,
Therefore, peeling of the reinforcing fiber sheet impregnated with the matrix resin can be prevented, and the reinforcing effect of the reinforcing fiber sheet can be sufficiently exerted.

[Brief description of drawings]

FIG. 1 is a perspective view illustrating the construction of a reinforcing fiber sheet on a concrete structure base portion according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view showing construction of a reinforcing fiber sheet.

FIG. 3 is a view showing a test piece used in an effect confirmation experiment conducted in the present invention.

FIG. 4 is a view showing a test piece used as a comparative example.

FIG. 5 is a diagram illustrating a tensile test method performed in an effect confirmation experiment.

FIG. 6 is a cross-sectional view showing a reinforcing fiber sheet.

FIG. 7 is a cross-sectional view illustrating the construction of a reinforcing fiber sheet on the base of a concrete structure according to a conventional method.

[Explanation of symbols]

 1, 18 Reinforcing fiber sheet 10 Concrete structure base 11 Horizontal part 12 Longitudinal part 13 Corner part 14, 17 Groove 15 Reinforcing bar 16 Concrete block

Claims (1)

[Claims] 1. A reinforcing fiber sheet having reinforcing fibers is attached to the surface of a concrete structure base having corners where longitudinal parts intersect with transverse parts and the matrix resin impregnated in the reinforcing fibers is cured. In the method of reinforcing the base portion, a groove is formed in a lateral direction portion at a corner portion of the base portion, and a lower end portion of the reinforcing fiber sheet arranged along the surface of the longitudinal portion is inserted into the groove, A method for reinforcing a base of a concrete structure, which comprises filling a resin with a resin and curing the resin.