JPH09242342A - Repair method of structure by carbon-fiber reinforced plastic sheet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a sufficient repair effect by coating the surface of a concrete structure with high-early-strength cement mortar, sticking a carbon-fiber reinforced plastic sheet and applying high-early-strength cement mortar. SOLUTION: The surface of a roughened concrete structure 1 is coated with high-early-strength cement mortar to flatten the surface, and a carbon fiber sheet 3 is abutted and stuck before cement mortar 2 is solidified from the upper section of the surface. The carbon fiber sheet 3 is impregnated with an epoxy resin 4. The surface of the carbon fiber sheet 3 is further coated with high-early- strength cement mortar 2 before the epoxy resin 4 is solidified, and high-early- strength cement mortar 2 and a carbon-fiber reinforced plastic sheet 5 are composted and unified. Accordingly, the receiving force of the structure is transmitted directly to carbon fibers, and the surface of a composite material is coated with cement mortar, and the composite material has excellent fire resistance.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to aging of existing structures such as bridge piers and buildings with concrete, and to a reinforcing method accompanying revision of the Building Standards Law and earthquake resistance standards, and in particular, carbon fiber reinforced plastic sheet. Related to the method of repairing structures.

[0002]

2. Description of the Related Art In recent years, carbon fiber, which has been developed as a high-strength material, is lightweight and chemically stable despite its Young's modulus and the like being 10 times stronger than that of rebar.
Since the diameter of the book is a thin fiber of 7 μm, it is used as a carbon fiber reinforced plastic, which is formed by arranging multiple fibers side by side and hardening them with a plastic such as epoxy resin to form a plain weave, for sports equipment, aircraft wings, etc. is the current situation.

Since carbon fibers have such excellent properties, as a method of utilizing the excellent properties of carbon fibers in reinforcing structures such as reinforced concrete, resin has been applied to structures aged after many years of use. Carbon fiber is applied to the structure to extend the service life of the structure.

As a concrete method of the reinforcement, as shown in FIG. 4, the surface of the structure a, which has been roughened by the use for many years, is first flattened by the uneven adjustment putty b, and then the epoxy resin is applied to the surface. The carbon fiber d, which is wrapped and solidified by c (as shown in the upper and lower parts in FIG. 4), is attached, and therefore the resin c is provided between the structure a and the carbon fiber d.
It has a structure that intervenes.

[0005]

The conventional method of directly applying the epoxy resin to the structure and attaching the carbon fiber to the structure as described above has various drawbacks as described below.

1) When the structure is made of cement concrete, the modulus of elasticity of the cement concrete is far from the modulus of elasticity of the carbon fiber, and the force received by the structure is difficult to be transmitted to the carbon fiber.

2) Generally used epoxy resins (hereinafter simply referred to as resins) have no fire resistance and are useless in the event of a fire.

3) The surface of the structure has become rough after many years of use, and it is necessary to carry out a surface smoothing treatment before applying the resin.

4) It is difficult to obtain the initial strength due to the curing characteristics and workability of the resin, and it is unsuitable for the reinforcement of a structure which is constantly subjected to an external force such as vibration.

5) Due to the curing characteristics of the resin, it is difficult to carry out at low temperature.

6) From the strength characteristics of the resin, in order to achieve the design strength, the average temperature is 10 ° C. for 2 weeks, the average temperature is 20 ° C.
It takes about 1 week for curing, and this period is too long.

7) Since the color of the resin is black or gray, the resin cannot be balanced with the structure, which is aesthetically unfavorable.

8) Although it depends on the type of resin, when the construction surface is exposed to direct sunlight, there is a high possibility that weather resistance will be a problem.

[0014]

DISCLOSURE OF THE INVENTION The present invention provides a method of repairing a structure, in which various drawbacks that occur when an epoxy resin is applied to a structure and carbon fibers are stuck thereto as described above are improved. As a means for solving the problem, a carbon fiber sheet is compositely integrated with a structure so as to utilize the adhesive force generated by a curing reaction of cement mortar and an epoxy resin.

That is, specifically, in the invention described in claim 1, the high-strength cement mortar is applied to the surface of the concrete structure to be repaired, and the carbon fiber reinforced plastic sheet is pasted thereon, The surface of a concrete structure to be repaired according to claim 2, wherein the early-hardening cement mortar and the carbon fiber reinforced plastic sheet are combined and repaired by applying the strong cement mortar. In, fixing the composite plate by integrating the early-strength cement mortar and the carbon fiber reinforced plastic sheet, and injecting grout cement mortar into the gap between the surface of the concrete structure for repairing, In the invention described in 3, the surface of the concrete structure to be repaired is coated with epoxy resin, and the carbon fiber reinforced Paste the stick sheet, characterized by repaired the early strength cement mortar and the epoxy resin and carbon fiber reinforced plastic sheet is a composite integrated by applying an early strength cement mortar thereon.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of a repairing method according to the present invention will be described with reference to the drawings shown below. FIG. 1 is an explanatory view with a cross section showing a first embodiment of a method of repairing a structure using a carbon fiber reinforced plastic sheet according to claim 1, and the procedure of the repair method will be described below in the order of numbers.

1) A high-strength cement mortar 2 is applied to the surface of the roughened concrete structure 1 to flatten the surface, and then the carbon fiber sheet 3 is applied to the cement mortar 2 before the cement mortar 2 hardens. Make contact and paste.

2) Next, the carbon fiber sheet 3 is impregnated with the epoxy resin 4 and the resin 4 is solidified to obtain the carbon fiber reinforced plastic sheet 5.

3) Before the epoxy resin 4 is solidified, the early-strength cement mortar 2 is further applied to the surface of the carbon fiber sheet 3 to finish the repair.

As a result, the early-strength cement mortar 2 and the carbon fiber reinforced plastic sheet 5 are compositely integrated.

FIG. 2 is a cross-sectional explanatory view showing an embodiment of a method for repairing a structure according to claim 2, and like the embodiment of FIG. 1, the procedure of the repair method will be described below in the order of numbers.

1) The early-strength cement mortar 2 is evenly flowed on a plate (not shown) which has been subjected to a mold release treatment, and the carbon fiber sheet 3 is abutted and attached before the early-strength cement mortar 2 solidifies.

2) Carbon fiber sheet 3 and epoxy resin 4
The composite plate 6 is formed by integrating the carbon fiber reinforced plastic sheet 5 obtained by impregnating the above with the early-strength cement mortar 2.

3) The composite plate 6 is fixed to the surface of the roughened concrete structure 1, and the grout cement mortar injection material 7 is injected between the surface of the concrete structure 1 and the composite plate 6 to remove the surface. Repairing is completed by finishing.

FIG. 3 is an explanatory sectional view showing an embodiment of a method for repairing a structure according to claim 3, and like the embodiment of FIGS. 1 and 2, the procedure of the correction method will be described below in the order of numbers.

1) The epoxy resin 8 is applied to the surface of the concrete structure 1, and the carbon fiber sheet 3 is brought into contact with and adhered to the epoxy resin 8 before the epoxy resin 8 is solidified.

2) Carbon fiber sheet 3 and epoxy resin 4
The carbon fiber reinforced plastic sheet 5 (first layer) is obtained by impregnating with.

3) By repeating the same operations as the above 1) and 2), the second layer of carbon fiber reinforced through the epoxy resin 8'applied on the first layer of carbon fiber reinforced plastic sheet 5 The plastic sheet 5'is obtained by overlapping.

4) Before the epoxy resin 4 of the second layer carbon fiber sheet 3 hardens, the surface of the fast-setting cement mortar 2
Repair is completed by applying and finishing the surface.

In this case, it is assumed that the rough surface of the concrete structure 1 is previously coated with the unevenness adjusting putty 9 and laid flat. Further, although the embodiment shown in FIG. 3 describes the case where the carbon fiber reinforced plastic sheet has two layers, the present invention is not limited to two layers.
It is also possible to repair one layer or more or more layers if necessary.

[0031]

According to the repair method described above, the present invention provides
Although the structure can obtain a sufficient repair effect, it has various effects listed below.

1) Cement mortar has a modulus of elasticity which is the same as or very close to that of a concrete structure, so that the force received by the structure is directly transmitted to the carbon fiber.

2) The composite materials shown in the respective embodiments are excellent in fire resistance because their surfaces are covered with cement mortar.

3) The use of cement mortar eliminates the need for ground preparation.

4) The setting time and strength development of cement mortar can be adjusted according to the operating conditions, and it is also suitable for reinforcement of a structure which is constantly subjected to external force such as vibration.

5) Cement mortar has a hardening property that allows it to be used even at low temperatures.

6) The color of the cement mortar is almost the same as the color of the conventional concrete surface, so that it does not spoil the appearance.

7) Since the surface is covered with cement mortar during repair, weather resistance is excellent.

[Brief description of drawings]

FIG. 1 is a cross-sectional explanatory view showing an embodiment of a repair method according to claim 1 of the present invention.

FIG. 2 is an explanatory sectional view showing an embodiment of a repairing method according to claim 2 of the present invention.

FIG. 3 is an explanatory sectional view showing an embodiment of a repair method according to claim 3 of the present invention.

FIG. 4 is an explanatory view with a cross section showing a conventional repair method.

[Explanation of symbols]

 1 Concrete structure 2 Early-strength cement mortar 3 Carbon fiber sheet 4 Epoxy resin 5,5 'Carbon fiber reinforced plastic sheet 6 Composite board 7 Grout cement mortar injection material 8,8' Epoxy resin 9 Unstable adjustment putty

Claims (3)

[Claims] 1. A high-strength cement mortar is applied to the surface of a concrete structure to be repaired, a carbon fiber reinforced plastic sheet is pasted onto the surface, and then a high-strength cement mortar is applied to the surface. A method for repairing a structure using a carbon fiber reinforced plastic sheet, which comprises repairing a composite cement mortar and a carbon fiber reinforced plastic sheet by combining them together. 2. A surface of a concrete structure to be repaired,
A carbon fiber reinforced plastic characterized by fixing a composite plate by integrating an early-strength cement mortar and a carbon fiber reinforced plastic sheet, and injecting grout cement mortar into a gap with the surface of the concrete structure for repair. How to repair a structure with a sheet. 3. An epoxy resin is applied to the surface of a concrete structure to be repaired, a carbon fiber reinforced plastic sheet is pasted on the epoxy resin, and an early-strength cement mortar is applied onto the epoxy resin to apply an early-strength cement. A method of repairing a structure using a carbon fiber reinforced plastic sheet, which comprises repairing a mortar, an epoxy resin, and a carbon fiber reinforced plastic sheet in a composite and integrated manner.