JPH09296615A - Repairing and reinforcing method for structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To restrain smell of resin after completion of resin coating work and to shorten the term of works by a method wherein repairing and reinforcing works for a structure are executed with the surface of a reinforcing fiber sheet impregnated with thermosetting resin covered at a specified percentage. SOLUTION: A reinforcing fiber sheet 3-1 is stuck all over the surface 2 of a structure, for which primary processing is applied, so that the axial direction of the fiber is aligned with the longitudinal direction of a concrete structure 1. Resin that becomes a matrix is applied to the surface of the reinforcing fiber sheet 3-1, and impregnation of resin and defoaming are executed with a defoaming roller applied. A reinforcing fiber sheet 3-2 is stuck likewise and furthermore, a reinforcing fiber sheet 3-3 is stuck with the axial direction of the fiber being aligned with the circumferential direction. The reinforcing fiber sheet 3-3 impregnated with resin at the outermost layer is covered with an airtight sheet 4. With covering by the airtight sheet 4 executed before starting of gelatination of resin after sticking, the airtight sheet 4 can be stuck fast to the unhardened resin, making work easy. The percentage of coverage by the airtight sheet 4 shall be 85-100%, and thereby bad smell can be prevented while the term of works being shortened.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for repairing / reinforcing a structure using fiber reinforced plastic.

[0002]

2. Description of the Related Art Even if structures such as buildings, ships, bridges, tunnels, dams, and chimneys made of materials such as concrete, iron, FRP and wood are deteriorated due to long-term use, they are repaired or reinforced. Life extension, that is, remodeling is performed. In particular, concrete structures such as bridges, tunnels, chimneys and buildings have deteriorated due to the neutralization of concrete and the generation of rust due to long-term use, the increase in load due to the reduction of the weight of passing vehicles, damage due to earthquakes and larger earthquakes. It has become necessary to repair and reinforce such as by reviewing the earthquake resistance standards assuming the above.

[0003] As a typical method of repairing and reinforcing concrete structures, a steel plate reinforcing method of bonding a steel plate to concrete is known, but the steel plate is heavy and is difficult to handle. For this reason, recently, reinforcing fibers such as carbon fibers, which have better characteristics than iron, have been impregnated with resin.
A method of reinforcing or repairing with a so-called fiber reinforced plastic is drawing attention.

This method of repairing / reinforcing a concrete structure using fiber reinforced plastic is, for example, to apply a room temperature curing type resin to the concrete surface to be repaired or reinforced, place a reinforcing fiber sheet on it, and then place it at room temperature. After applying a curable resin, the impregnating roller is brushed to impregnate the reinforcing fiber sheet with the resin, and if necessary, this is repeated and the resin is cured at room temperature. However, the room temperature curable resin is composed of a main agent and a curing agent, but during the resin coating operation and during the room temperature curing of the resin, the volatile components constituting the main agent and the curing agent evaporate,
It gives off a bad odor such as ammonia, amine, formalin, styrene and phenol, and causes a lot of discomfort. For the resin application work, it is possible to take measures against it by, for example, wearing a deodorant mask and performing sufficient ventilation. However, the curing speed of the room temperature curable resin is slow, and it usually takes about one week at room temperature to complete the curing reaction. Although the odor decreases as the curing progresses, it emits an odor during the curing period, so the problem is that the resident will not be able to return forever and the construction period will be long, especially when repairing or reinforcing the building. There is. On the other hand, if the occupant moves in before the curing of the resin is not sufficiently completed, the occupant's discomfort increases. Similarly, repairs in the tunnel,
In the case of reinforcement work, a foul odor will be kept in the tunnel forever, and discomfort will increase when passing through the tunnel.

On the other hand, immediately after the resin coating work is completed, fireproof coating with mortar or the like can suppress the generation of odor, but the moisture in the mortar hinders the reaction of the curing agent, and the resin does not harden forever, resulting in a sufficient reinforcing effect. There is a problem that can not be obtained.

[0006] In addition, since the room temperature curing type resin used in the field construction prevents resin from dripping, the reinforcing fiber sheet is poorly impregnated with the resin, and after the resin application work is completed, the reinforcing fiber causes a springback phenomenon. There was a problem that the surface of the fiber reinforced plastic after swelling and curing was uneven, and the appearance was impaired.

[0007]

SUMMARY OF THE INVENTION The present invention pays attention to such a situation, and can easily suppress the odor of the resin after completion of the resin application work, shorten the construction period, and reduce the surface of the fiber reinforced plastic. It is an object of the present invention to provide a method for repairing / reinforcing a structure having a smooth surface.

[0008]

In order to achieve the above object, in the present invention, a reinforcing fiber sheet impregnated with a thermosetting resin is attached to the surface of a structure, and the thermosetting resin is cured. In repairing / reinforcing a structure, there is provided a method for repairing / reinforcing a structure, which comprises covering the outer surface of the reinforcing fiber sheet with an airtight sheet.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in detail below.

The present invention will be described based on the embodiment shown in FIG. 1. In the method of repairing and reinforcing a structure 1 made of concrete with fiber reinforced plastic, first, if necessary, repairing and reinforcing is performed. Impurities such as oil adhering to the structure surface 2 are removed with an organic solvent such as acetone or soapy water, and mortar or resin is filled in the cracked portion of the concrete surface or the chipped portion of the concrete. Depending on the condition, the convex portion of the concrete is ground to smooth the adhesive surface, or the concrete surface is treated with a sander. Then, in order to improve the adhesiveness between the concrete surface and the fiber-reinforced plastic plate after curing, an epoxy resin-based primer having a low viscosity is applied, if necessary, and 1
Leave for about 2 days until the primer resin is cured.
Next, apply the resin that becomes the matrix of fiber reinforced plastic to the concrete structure surface with an application roller etc.,
Using a unidirectional reinforcing fiber sheet in which reinforcing fibers are arranged in the length direction of the sheet, a reinforcing fiber sheet impregnated with resin impregnation is prepared and attached on site. Specifically, first, the reinforcing fiber sheet 3-1 is attached to the entire surface of the structure so that the axial direction of the reinforcing fiber is the length direction of the concrete column, and the resin serving as a matrix is applied onto the reinforcing fiber sheet 3-1. Then, a defoaming roller is placed on the reinforcing fiber sheet 3-1 to impregnate the reinforcing fiber sheet 3-1 with the resin, and defoaming is performed at the same time. Paste,
The resin is applied and the defoaming roller is applied, then the unidirectional reinforcing fiber sheet 3-3 is attached so that the fiber axis direction is the circumferential direction of the concrete column, and the resin is applied and the defoaming roller is applied to the structure surface. Paste on.

These laminating operations are repeated depending on the degree of repair and reinforcement to determine the number of laminated layers, that is, the amount of reinforcing fibers.
The above is a conventional method of reinforcing a concrete structure with fiber reinforced plastic, and does not change at all in the present invention. In the present invention, after the reinforcing fiber sheet impregnated with the thermosetting resin is attached to the structure surface, the reinforcing fiber sheet impregnated with the resin is further covered with the airtight sheet 4, and the uncured or in the middle of curing. It is intended to prevent the resin in (1) from contacting with air and to suppress the evaporation of volatile components such as ammonia, amine, formalin, styrene and phenol, which constitute the main agent and the curing agent.

If the resin-impregnated reinforcing fiber sheet is covered with the airtight sheet after the resin-impregnated reinforcing fiber sheet of the outermost layer is attached and before the gelation of the resin begins, the airtight sheet and the uncured resin adhere to each other. This is preferable because the work of attaching the airtight sheet becomes easy and the odor is completely contained.

The area ratio of covering the resin-impregnated reinforcing fiber sheet with the airtight sheet is preferably 100%, that is, it is sufficient if it can be completely covered, but if it can cover at least 85% or more, a considerable person feels discomfort. Disappear.

The airtight sheet used in the present invention means polyester, polyamide, polyvinyl chloride, ethylene polyterephthalate, polyvinyldene chloride, polyvinyl fluoride,
Examples thereof include resin films such as polypropylene, polyethylene and polystyrene, cellophane, woven fabrics, coated cloth obtained by applying resin coating treatment to unwoven cloth and paper, and silicone paper in which paper is impregnated and coated with a silicone release agent. Above all, it is difficult for gas to permeate,
That is, a film having high gas barrier properties such as polyester, polyamide, polyvinyl chloride, ethylene polyterephthalate, polyvinyldene chloride and polyvinyl fluoride, cellophane and silicone paper are preferable.

The airtight sheet preferably has excellent flexibility so as to cover the entire surface of a column or beam having a circular or rectangular cross section and to improve the adhesion to the resin which is uncured or is in the process of curing. The sheet thickness is usually 30-200 microns. If it is less than 30 μm, wrinkles are liable to be formed in the sheet and the handleability is poor. Further, since the sheet is thin, odor tends to pass through the sheet and it is difficult to block the odor. On the other hand, when the thickness of the sheet exceeds 200 microns, wrinkles are less likely to enter and handling is excellent, but the rigidity is high. Therefore, if the sheet is arranged along a cylinder or a square pole, the uncured thermosetting resin and the sheet are separated. Since the adhesive strength of is small, the sheet floats up from the resin-impregnated reinforcing fiber sheet,
Smells tend to escape from the gap and weaken the blocking effect. The method of coating the resin-impregnated reinforcing fiber sheet with the airtight sheet is, for example, in the case of pillar construction, winding a first airtight sheet having a width of 100 cm around the entire circumference of the pillar, and circumferentially extending the end portion of the first airtight sheet in the circumferential direction. Then, the airtight sheet at the cut portion and the airtight sheet wound around the column are bonded with an adhesive tape in the longitudinal direction of the column. Next, a new second airtight sheet is wound around the already wound first airtight sheet so as to slightly overlap the first airtight sheet in the longitudinal direction, and the first airtight sheet and the second airtight sheet are wound together. The end portion of the airtight sheet of No. 2 is adhered to the circumferential direction of the column with an adhesive tape, and at the same time, the end portion of the second airtight sheet is cut so that the end portion thereof slightly overlaps in the circumferential direction. The second airtight sheet wound around the pillar is bonded to the pillar in the length direction of the pillar with an adhesive tape. When the length of the column is long, by repeating this, it is possible to perform coating with excellent airtightness.

In the repairing / reinforcing method of the present invention, since the airtight sheet covers the resin-impregnated reinforcing fiber sheet, the airtight sheet suppresses the swelling of the reinforcing fiber due to the springback phenomenon after the resin application work is completed. Therefore, the surface of the fiber reinforced plastic after curing will not be uneven,
It also has the effect of becoming smooth.

In the present invention, normally, after the thermosetting resin is cured, the airtight sheet is peeled off and the subsequent work is carried out. However, before the thermosetting resin is sufficiently cured, the airtight sheet is heated. It is also possible to further provide a mortar layer on the curable resin in a state of being attached thereto. Curing of thermosetting resin is inhibited in the presence of water,
In the present invention, the contact between the water of the mortar and the thermosetting resin is blocked by the presence of the airtight sheet, so that the mortar can be applied before the resin is sufficiently cured. Since you can immediately apply mortar coating for the next fireproof coating until the resin cures, you do not have to interrupt the construction until the resin cures, you can shorten the construction period,
It is efficient. In this case, repair the airtight sheet.
Since it will be a part of the structure after reinforcement, an airtight sheet made of polyamide, which has good adhesiveness to the thermosetting resin and excellent alkali resistance, is preferable.

In the present invention, after the thermosetting resin is cured, the airtight sheet may be peeled off and a mortar layer may be provided.

The mortar used in the present invention may be a normal mortar in which cement is used as a binder to bond sand as an aggregate, but in order to enhance the adhesiveness between the mortar and the airtight sheet or fiber reinforced plastic. As the binder, cement and a polymer such as styrene butadiene, latex, ethylene vinyl acetate or polyacrylic acid ester may be used, and a sand-bonded polymer cement mortar may be used.

In the present invention, the matrix resin applied to the sheet-like reinforcing fiber material is preferably a room temperature curable thermosetting resin. As the thermosetting resin, epoxy resin,
Specific examples include funol resins, vinyl ester resins, melamine resins, silicon resins and unsaturated polyester resins. Among them, since epoxy resin has excellent alkali resistance, even if the structure is made of concrete, it will not be deteriorated due to secular change due to being invaded by alkaline concrete. Well, the reinforcing effect of the structure by the reinforcing fiber is great. Also, if the matrix resin cures at room temperature, leave it after the resin impregnation work,
The hardening progresses and it adheres well to concrete and reinforcing fibers, making repair and reinforcement work easier. In particular, in the case of repairing / reinforcing the inside of a building or the inside of a tunnel, a non-flammable material is required for the material used, and thus a room temperature curable phenol resin is preferably used. Here, the room temperature-curable thermosetting resin generally means that the temperature of the use atmosphere is 20 ° C.
At that time, it means a thermosetting resin in which gelation starts about 30 minutes to 5 hours after mixing the main agent and the curing agent.

The progress of curing in the thermosetting resin is governed by the kind and amount of the curing agent used, but in the case of the room temperature curing type thermosetting resin, the main component and the curing agent are mixed and Polymerization proceeds considerably for about 2 days (48 hours) at room temperature after resin impregnation, and volatile components such as ammonia, amine, formalin, styrene and phenol react and are trapped in fiber reinforced plastic, so it is airtight. Even if the sheet is removed, the foul odor is alleviated, and it does not cause human discomfort.

The reinforcing fiber used in the present invention is a multifilament yarn in which a large number of filaments are bundled, and is a high-strength / high-modulus fiber such as carbon fiber, polyaramid fiber or glass fiber. Among them, carbon fiber is not corroded by alkali and is preferable as a reinforcing fiber used in the present invention.

The form of the reinforcing fiber sheet is such that the reinforcing fiber yarns are arranged in the warp direction and the weft yarns are woven with fine auxiliary yarns, or the reinforcing fiber yarns are arranged in the warp direction and the weft direction. It may be a bidirectional woven fabric.

In another form of the reinforcing fiber sheet, reinforcing fiber yarns are arranged in parallel in one direction, and a supporting material such as mesh or paper is used to carry the reinforcing fiber sheet, and the supporting material is made of 3 to 10% by weight of resin. It may be a bonded unidirectional material. Further, it may be a sheet-shaped fiber material such as a prepreg or a woven material or a unidirectional material impregnated with a resin in advance. As the resin serving as the matrix of the prepreg, the above-mentioned thermosetting resins such as epoxy resin, vinyl ester resin, unsaturated polyester resin and phenol resin are used.

The repairing / reinforcing method of the present invention can be applied to structures installed outdoors such as bridge piers, floor slabs and girders, but especially in columns, walls and beams inside buildings, and inside tunnels. When applied to repair / reinforce areas with poor air circulation, bad odors can be prevented, so it is possible to enter or pass through without waiting for the resin to harden, which can shorten the construction period and make people who enter or pass through discomfort. Is preferable because it does not give

In the above embodiment, the case where the material constituting the structure is concrete is described.
Even for structures made of materials such as iron, FRP and wood, the same repair and reinforcement methods can be used to prevent the bad odor of the thermosetting resin until it hardens, and the plastic surface The same effects as those of the above-described embodiment can be obtained such as smoothing.

[0027]

【Example】

(Example 1) A room having a volume of 900 m ³ has a square cross section with a size of 30 cm × 30 cm, and a corner portion has a radius R of 6 m.
m, 3 m long concrete column with epoxy resin-based primer evenly applied on the concrete surface and left for one day and night. When the primer became semi-cured, room temperature curing type epoxy resin was applied at 300 g / It was evenly applied to the entire surface so as to be m ² . Unidirectional carbon fiber woven fabric A in which carbon fibers are arranged in the lengthwise direction and thin glass fibers are used in the transverse direction and the basis weight of the carbon fibers is 300 g / m ^2.
Is placed so that the arrangement direction of the carbon fibers is the length direction of the pillar so as to cover the entire surface of the pillar, and the resin is evenly applied on the entire surface so that the amount of resin applied is 500 g / m ^2. The fabric was impregnated with the impregnating roller. Further, a unidirectional carbon fiber woven fabric A was placed thereon, 500 g / m ² of resin was applied and impregnated into the woven fabric, and this was repeated, and four total carbon fiber woven fabrics A were laminated and impregnated with resin. Immediately after the resin impregnation work, the resin-impregnated carbon fiber woven fabric was covered with a 100-micron-thick airtight polyester film, and the seams of the films overlap the film and the film by about 5 cm, and the joining portion is bonded with an adhesive tape. Glued The coverage of the resin-impregnated reinforcing fiber sheet with the airtight sheet is 90.
%Met. After that, thoroughly ventilate the room, let out the odor during the resin application work, shut off the window, let 10 people enter the room, and performed an odor test.
Nine had no odor.

(Comparative Example 1) The resin-impregnated carbon fiber woven fabric was not covered with an airtight film, and the other conditions were exactly the same as those of the examples, and the room was sufficiently ventilated to apply the resin. Odor was released, the windows were closed, and 10 people entered the room and tested for odor.
Both people felt a bad odor, seven felt unwell and two complained of headaches.

[0029]

According to the present invention, when repairing / reinforcing a structure with a fiber reinforced plastic having a thermosetting resin as a matrix, it is possible to easily suppress the odor of the resin after the resin application work is completed, and the construction period can be reduced. Not only can the length be shortened, but the surface of the fiber reinforced plastic can be made smooth.

[Brief description of drawings]

FIG. 1 shows an FRP for explaining an embodiment of the present invention.
It is a partially broken perspective view of a reinforcement structure.

[Explanation of symbols]

 1 Concrete Structure 2 Concrete Structure Surface 3-1 Unidirectional Reinforcing Fiber Sheet 3-2 Unidirectional Reinforcing Fiber Sheet 3-3 Unidirectional Reinforcing Fiber Sheet 4 Airtight Sheet

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code Agency reference number FI Technical display location B29K 105: 08

Claims (11)

[Claims] 1. A reinforcing fiber sheet impregnated with a thermosetting resin is attached to a structure surface, and when the thermosetting resin is cured to repair or reinforce the structure, the outer surface of the reinforcing fiber sheet. A method for repairing / reinforcing a structure, characterized in that the sheet is covered with an airtight sheet. 2. The method for repairing / reinforcing a structure according to claim 1, wherein a covering ratio of the reinforcing fiber sheet with the airtight sheet is 85 to 100%. 3. The method for repairing / reinforcing a structure according to claim 1, wherein the airtight sheet is an airtight sheet having a high gas barrier property. 4. The method for repairing / reinforcing a structure according to claim 1, wherein the airtight sheet is peeled off after the thermosetting resin is cured. 5. The method according to claim 1, wherein after the thermosetting resin is cured, the airtight sheet is peeled off, and then a mortar layer is provided on the outer surface of the reinforcing fiber sheet. How to repair / reinforce the described structure. 6. The thermosetting resin is a room temperature curable epoxy resin, and the period from the impregnation of the resin to the peeling of the airtight sheet is at least 48 hours or more. Alternatively, the method for repairing / reinforcing a structure according to claim 5. 7. The method for repairing / reinforcing a structure according to claim 1, wherein a mortar layer is provided further outside the airtight sheet. 8. The method for repairing / reinforcing a structure according to claim 5, wherein the mortar is a polymer cement mortar. 9. The method for repairing / reinforcing a structure according to claim 1, wherein the structure is made of concrete. 10. The method for repairing / reinforcing a structure according to claim 1, wherein the structure surface is an inner surface of a building. 11. The method for repairing / reinforcing a structure according to claim 1, wherein the structure surface is an inner surface of a tunnel.