JP3109409B2 - Reinforcing fiber sheet for concrete structures - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a concrete structure.
The present invention relates to a reinforcing fiber sheet for a concrete structure used for repair and reinforcement .

[0002]

2. Description of the Related Art Concrete structures such as bridges, tunnels, chimneys and buildings deteriorate due to neutralization of kuncrete and rust due to long-term use, increase in load due to reduction in the weight of passing vehicles, and damage due to earthquakes. Repairs and reinforcements have become necessary due to the revision of seismic standards for large earthquakes. Grasping the deteriorated state of the concrete structure, human surface condition of the concrete, and in particular the crack progress state, being carried out by observing the size. Its observation, since it is not widespread Niwa or human being, depending on the time, a inaccurate or miss cracking, also required a great effort.

[0003] Repairing such concrete structures
As a typical method of reinforcement, a steel plate reinforcement method of bonding a steel plate to concrete is known, but the steel plate is heavy,
Difficult to handle. For this reason, a method of reinforcing or repairing with a so-called fiber-reinforced plastic in which a resin is impregnated with a reinforcing fiber such as carbon fiber, which is superior in characteristics to iron, has been attracting attention. However, even if a concrete structure is reinforced or reinforced, deterioration due to neutralization of the concrete or generation of rust proceeds. This concrete structure is covered with fiber reinforced plastic so that the concrete surface is not visible. Therefore, the degradation state of this concrete structure must be grasped by human observation, but it is necessary to observe the degradation state of the Kunkrete surface at places not covered with fiber-reinforced plastic, Obviously, it is necessary to observe the change in the state of the plastic, which is not only inaccurate, but also causes a delay in finding an abnormality in the concrete structure.

[0004] A method of detecting distortion of a concrete structure due to a load applied for some reason by a change in electric resistance of FRP made of carbon fiber and glass fiber embedded in concrete is described in "Reinforced Plastics."'' Vol.
41, No. 4, pages 16 to 18 (1995). This is to try to use the principle that the cutting of the carbon fiber progresses stepwise when the tensile strain increases and the electrical resistance increases, but depending on the type of resin, the cutting of the carbon fiber does not progress stepwise, There were problems in reproducibility and reliability, such as cutting at a stretch, and different levels of electrical resistance depending on the ratio of resin to fiber.

[0005]

SUMMARY OF THE INVENTION The present invention focuses on such a current situation and provides a simple and reliable concrete structure.
Reinforcement fiber sheet for concrete structures that can be repaired and reinforced and the deterioration state of concrete can be detected.
To provide them .

[0006]

The present invention solves such a problem.
In order to solve the problem, the following means should be adopted.
You. That is, the reinforcing fiber for a concrete structure of the present invention
The sheet is made up of a number of reinforcing fiber yarns woven by auxiliary yarns.
Forming tissue or contacting the support with an adhesive
The fiber weight is 200 to 700
g / m ² , wherein the reinforcing fibers
The yarn is sparse, and the conductive yarn with a smaller breaking elongation is sparse
Characterized by being arranged and included in
Things.

[0007]

DETAILED DESCRIPTION OF THE INVENTION The present invention has been made to solve the above problem, that is
In and reliably child the repair and reinforcement of concrete structures
In addition to being able to detect the deterioration state of concrete
Serious inspection of reinforcing fiber sheet for concrete structures
The specific reinforcing fiber line consisting of a number of reinforcing fiber yarns
I tried to solve these issues all at once
It is something that has been determined.

According to the present invention, a reinforcing fiber sheet as a fibrous material for reinforcing and repairing a concrete structure capable of easily detecting deterioration and abnormal conditions of the concrete structure, a reinforced plastic plate comprising the sheet fiber, and A concrete structure reinforced and repaired with the reinforcing fiber sheet or the reinforced plastic plate is provided.

A specific embodiment of the reinforcing fiber sheet according to the present invention will be described with reference to the drawings. FIG. 1 shows a reinforcing fiber sheet according to an embodiment of the present invention. In FIG. 1, reference numeral 1 denotes a reinforcing fiber yarn, in which a large number of reinforcing fiber yarns are arranged in parallel, and a conductive yarn 2 is formed in parallel. The reinforcing fiber yarns 1 and the conductive yarns 2 are alternately interspersed with one thin auxiliary yarn 3 alternately at regular intervals between the reinforcing fiber yarns arranged to form a weave structure . configured to form a reinforcing fiber sheet.

The reinforcing fibers used in the present invention are high-strength, high-modulus fibers such as multifilament carbon fibers, glass fibers and polyaramid fibers. Among them, carbon fibers have excellent chemical resistance and have been used for many years. However, it is not violated by the strong alkali of concrete. In addition, since carbon fiber has a low fiber density, uncured resin-impregnated fiber sheets do not fall when repairing and reinforcing the lower surface of concrete structures such as floor slabs and floors by hand lay-up molding. It is preferably used.

The conductive yarn used in the present invention is a reinforcing fiber yarn.
It is important that the articles are sparsely arranged and included.
You. Such a conductive yarn may be a multi-filament or a mono-filament such as a metal or carbon fiber having a reinforcing fiber sheet conductive property, but concrete structures in the civil engineering and construction fields have been used in a severe environment for 60 years. 10
Since durability of 0 years is required, metal fibers and carbon fibers made of platinum, titanium, stainless steel, and alloys thereof, which hardly generate rust, are preferable. In addition, when the conductive yarn is a carbon fiber, it is preferably used because it can play the role of the reinforcing function as well as the reinforcing fiber yarn as well as the electric conductivity function.

Since the conductive yarn used in the present invention does not essentially contribute to the reinforcement of concrete, it is sparse.
It is not necessary to use many of them, and the weight ratio to the reinforcing fiber yarn is 0.01 to 50.
% Is preferable, and more preferably 0.01 to 10%.

The spacing of the conductive yarns sparsely arranged may be at least one in the reinforcing fiber sheet. When a large number of conductive yarns are inserted, the spacing is 5 to 50 cm. It can be used and need not necessarily be equally spaced.

[0014] fiber weight of the reinforcing fiber sheet, for the reason that to increase the number of stacked upon small and molding, large and resin impregnation becomes incomplete, 200 per square meter
It is important that it is ７００700 g. Further, if the width of the reinforcing fiber sheet is small, the number of moldings increases, and if the width is large, handling becomes difficult. If the sheet is molded outdoors, problems such as difficulty in determining the lamination position due to the wind occur.
It is preferably about 00 cm.

In the present invention, the deterioration or abnormal state of the concrete structure can be detected by the change in the electrical conductivity or the electrical resistance of the conductive yarn. That is, when a conductive yarn that breaks at a predetermined tensile strain is used, when a strain equal to or greater than the breaking strain of the conductive yarn is applied to the concrete surface, the conductive yarn breaks and loses electrical conductivity, or Even if the conductive thread that has been cut once is re-adhered, the electrical resistance value is greatly increased, so that the strain history of the concrete surface can be accurately grasped.

Therefore, in the present invention, it is important that the elongation at break of the conductive yarn is smaller than the reinforcing fiber yarn.
You . When at least two kinds of conductive fibers having different elongation at break are used, the strain history of the concrete surface can be grasped more accurately.

That is, a reinforcing fiber using carbon fibers having a breaking elongation of 2.0% as the reinforcing fiber yarn and carbon fibers having a breaking elongation of 0.5% and 1.0% as the conductive yarn. Investigate concrete structures reinforced with sheets, 0.5%
If the conductive yarn is broken and 1.0% of the conductive yarn is normal, the structure has undergone a strain history of at least 1.0%. It is possible to read that it has not been applied and that it can still withstand use .

Difference in elongation at break between the reinforcing fiber and the conductive yarn,
It is preferable that the difference between the breaking elongations of two or more conductive yarns having different breaking elongations is at least 0.2%, since the presence or absence of electrical conductivity can be clearly detected.

[0019] Incidentally, since the carbon fibers are conductive, if the reinforcing fibers are carbon fibers, even if disconnection conductor resistance yarns, is impaired conductivity of the conductive yarns when in contact with the carbon fibers because it may not, on both sides of the conductive yarns, or when the reinforcing fiber sheet of electrically insulating yarns are arranged in parallel. Glass fiber as the fiber used as the electrically insulating yarn,
Polyaramid fiber, vinylon fiber, polyester fiber,
There are polyamide fiber, polyethyl fiber, polypropylene fiber and the like. Among them, glass fiber and polyaramid fiber are high strength and high elastic modulus fibers, and are preferable because they have a reinforcing effect as well as an electrical insulating property.

Further, reinforcing the reinforcing fiber sheet by multilayer lamination, to repair, if the reinforcing fibers are carbon fibers, the conductivity of the conductive yarns be the same conductive yarns and disconnection impaired Therefore, the reinforcing fiber sheet and the electrically insulating sheet may be alternately laminated , and the electric insulating sheet may be interposed between the reinforcing fiber sheets.

As the electrically insulating sheet, glass fiber,
Polyaramid fiber, vinylon fiber, polyester fiber,
Fabrics and mats made of electrically insulating fibers such as polyamide fibers, polyethyl fibers, and polypropylene fibers.
Sheets having resin impregnation are preferred.

The form of the reinforcing fiber sheet is a number of reinforcing fibers.
Whether the weft forms a woven structure with the auxiliary yarn, or
Or bonded to the support with an adhesive and integrated
Things are used. In other words, the former weave structure
The reinforcing fiber yarn and the conductive yarn are arranged in the warp direction,
A one-way woven fabric in which the weft yarn forms a woven structure with a thin auxiliary yarn or a two-way woven fabric in which reinforcing fiber yarns and conductive yarns are arranged in the warp direction and the weft direction are used . In the case of a two-way woven fabric, it is better to arrange the reinforcing fiber yarns only in one direction in the warp direction and the weft direction, and to arrange the conductive yarns only in one direction in the warp direction or the weft direction. It is preferable because it can be performed. Also supported by the latter adhesive
The one-piece material that is bonded and integrated with the body is one-way material in which the reinforcing fiber yarns are supported by a mesh-like support material arranged in parallel in one direction, or the fabric and the one-way material are impregnated with resin in advance. Use a sheet such as a prepreg integrated
Can be

As the resin serving as the matrix of the prepreg, a thermosetting resin such as an epoxy resin, a vinyl ester resin, an unsaturated polyester resin, or a phenol resin is used. Among them, the epoxy resin has a large adhesive force and a high alkali resistance. It is preferable because it is excellent. The matrix resin is not limited to a thermosetting resin, and may be a thermoplastic resin such as a nylon resin, an ABS resin, a polypropylene, a polyethylene resin, a vinyl chloride resin, and a polyurethane resin.

Such a reinforcing fiber sheet may be formed in advance into a fiber reinforced plastic plate and bonded to concrete with an adhesive, or a room temperature curing resin may be applied to a concrete structure to be repaired or reinforced. After application, a reinforcing fiber sheet is placed thereon, and a room-temperature-curable resin is further applied thereon, then the impregnating roller is applied to impregnate the reinforcing fiber sheet with the resin, and an electric insulating sheet is laminated thereon,
It may be an on-site construction in which an impregnating roller is brushed, this is repeated as necessary, and the resin is cured at room temperature.

When a conductive paste is applied to both ends of the conductive thread of the reinforcing fiber sheet of the fiber reinforced plastic plate adhered to the concrete structure, if necessary, terminals are attached thereto. By examining the electrical continuity and the electrical resistance between the terminals of the sex yarn with a tester, the deterioration state of the concrete structure can be easily diagnosed.

[0026] Figures 2-6 are views for explaining an actual <br/>施例the concrete structure reinforcement fiber sheet of the present invention is used in concrete structures, 2 piers 4, 3 girders 5,
Fig. 4 shows the concrete of the floor slab 6, and Fig. 5 shows the concrete of the chimney 7.
Fig. 6 shows concrete on the concrete outer surface of the structure .
The reinforcing fiber sheet for a concrete structure of the present invention is applied to the outer surface of the concrete inside the tunnel 8 as a structure.
This shows a state in which the fiber reinforced plastic 9 is adhered. In these embodiments, the reinforcing fiber sheet 10 of the one-way woven fabric is laminated and formed so that the fiber axis direction of the one-way woven fabric is one layer at a time in the length direction and the width direction of the concrete structure. It can be determined as needed.

[0027]

The reinforcing fiber sheet for a concrete structure according to the present invention contains a conductive thread. Therefore, if the reinforcing fiber sheet is used as a fiber material of a fiber reinforced plastic for repairing and reinforcing a concrete structure, the reinforcing fiber sheet can be reinforced. Since the conductive yarn breaks in a region of lower strain than the fiber yarn and loses electrical conductivity or changes greatly in electric resistance, abnormality of the concrete structure can be detected at an early stage.

[0028] in concrete structures, concrete of the present invention
When using over preparative structure reinforcing fiber sheet, preferably
Or the use of fiber reinforced plastic, the state of deterioration of the reinforced and repaired concrete can be detected by the electrical conductivity and electrical resistance of the conductive yarn,
The can Ru can be further discovered cracks occurring in concrete covered with a fiber reinforced plastic
Thus, the deterioration state of the concrete structure can be accurately inspected. In addition, abnormalities in the concrete structure can be found at an early stage.

[Brief description of the drawings]

FIG. 1 shows a concrete structure according to an embodiment of the present invention.
FIG. 2 is a perspective view of a reinforcing fiber sheet for use .

FIG. 2 is a reinforcing fiber sheet for a concrete structure of the present invention.
Which is a schematic diagram illustrating a specific embodiment using a concrete structure.

FIG. 3 is a reinforcing fiber sheet for a concrete structure of the present invention.
Which is a block diagram for explaining another specific example of using a concrete structure.

FIG. 4 is a reinforcing fiber sheet for a concrete structure of the present invention.
Which is a block diagram for explaining another specific example of using a concrete structure.

FIG. 5 is a reinforcing fiber sheet for a concrete structure of the present invention.
Which is a block diagram for explaining another specific example of using a concrete structure.

FIG. 6 is a reinforcing fiber sheet for a concrete structure of the present invention.
Which is a block diagram for explaining another specific example of using a concrete structure.

[Explanation of symbols]

 1: Reinforcing fiber yarn 2: Conductive yarn 3: Auxiliary yarn 4: Bridge pier 5: Bridge 6: Floor slab 7: Chimney 8: Tunnel 9: Fiber reinforced plastic 10: Unidirectional woven fiber sheet

──────────────────────────────────────────────────続 き Continued on the front page (58) Fields surveyed (Int. Cl. ⁷ , DB name) E04C 5/00-5/20 E04B 1/16 E01D 1/00-23/00 E04G 23/00-23 / 08 D03D 1/00-27/18

Claims (12)

(57) [Claims] 1. A large number of reinforcing fiber yarns are supported by auxiliary yarns.
Form a woven tissue or
Adhesive and integrated , fiber weight 200-70
A seat is in the range of 0 g / m ^2, the reinforcing fiber yarns, characterized in that the small conductive yarn it from breaking elongation are those included are sparsely arranged Reinforcing fiber sheet for concrete structures . 2. The reinforcing fiber sheet for a concrete structure according to claim 1, wherein the reinforcing fibers are carbon fibers. 3. The reinforcing fiber sheet for a concrete structure according to claim 1, wherein the reinforcing fibers are glass fibers. 4. The reinforcing fiber sheet for a concrete structure according to claim 1, wherein the reinforcing fiber is a polyaramid fiber. 5. The reinforcing fiber sheet for a concrete structure according to claim 2, wherein an electrically insulating yarn is arranged next to the conductive yarn. 6. The yarn according to claim 5, wherein the conductive yarn is a carbon fiber yarn.
The reinforcing fiber sheet for a concrete structure according to item 1 . 7. The method of claim weight fraction of conductive yarns for the reinforcing fiber yarns in the range of 0.01 to 50% 2-6
The reinforcing fiber sheet for a concrete structure according to any one of the above. 8. The difference of elongation at break of the reinforcing fibers and conductive, concrete structures reinforcement fiber sheet according to any one of claims 1 to 7, at least 0.2%. 9. At least two co according to any one of claims 1 to 8 made of different conductive fibers fracture elongation
Reinforcing fiber sheet for concrete structures . 10. The concrete structure according to claim 9, wherein the difference in the elongation at break between the conductive fibers is at least 0.2% .
For reinforcing fiber sheet. 11. Many present concrete structures reinforcement fiber sheet according to any one of claims 1 to 10, the conductive yarns in the reinforcing fiber yarns, which are arranged at equal intervals of. 12. The reinforcing fiber sheet for a concrete structure according to claim 5, wherein the electrically insulating yarn is a yarn made of glass fiber.