JPH01195025A - Method of reinforcing structures using carbon fiber reinforced plastic plates - Google Patents

Abstract

PURPOSE:To flatly bond a carbon fiber reinforced plastic plate to the surface to be reinforced of a construction, by bonding the carbon fiber reinforced plastic plate to the surface to be reinforced of the construction through an adhesive and subsequently pressing the plastic plate to the surface to be reinforced by a press means equipped with an air bag to fix the same to the surface to be reinforced of the construction. CONSTITUTION:If necessary, cleaning is simply performed and an adhesive 3 is applied to the surface to be reinforced of a concrete slab 1 in a predetermined thickness directly or after a primer is applied. Next, a carbon fiber reinforced plastic plate 2 is pressed to the slab 1 on one end side thereof and subsequently pressed to the surface 1a to be reinforced of the slab 1 toward the other end thereof in succession so that no air is interposed between the surface 1a of the slab 1 and the surface of the plastic plate 2 to be bonded thereto. Subsequently, the plastic plate 2 boded to the surface 1a of the slab is pressed by a press means 10 equipped with an air bag 11.

Description

[Detailed Description of the Invention] 1. The present invention includes reinforcement of beams of concrete structures, floor slabs, and various other structures, as well as repair of structures such as waterproofing of structures and prevention of air leaks. The present invention relates to a method for reinforcing a structure, and particularly to a method for reinforcing a structure in which such reinforcement is performed using a carbon fiber reinforced plastic plate.

[The beams, floor slabs, and other structures of Suetoyo Kagekari concrete structures deteriorate over many years of use, and their strength decreases due to bending stress and other effects, resulting in the need for reinforcement, and in some cases, waterproofing,
It will be necessary to carry out various repairs and reinforcements such as preventing air leaks.

Conventionally, to strengthen such structures, for example, steel plates are used as reinforcing materials to recover the strength loss due to deterioration of the concrete slab of a concrete structure, and the steel plates are used to strengthen the reinforcement points using anchor bolts, etc. A method of fixing it was used. This method of reinforcing requires iron plates as the reinforcing material, which increases the weight, making it difficult to handle the reinforcing material when reinforcing large areas, and depending on the reinforcement location, it may be impossible to install the steel plates. , which was often extremely difficult and resulted in problems with poor work efficiency.

In order to solve this problem, we developed a product that is extremely light in weight.
Carbon fiber reinforced plastic plates are used as the reinforcing material because they are easy to attach to the reinforced surface, have high tensile strength and elastic modulus, and have excellent weather resistance, water resistance, heat resistance, etc. A reinforcement method has been proposed.

- The reinforcement method of using such carbon fiber reinforced plastic plates as reinforcement material or repair material for other purposes is very suitable for reinforcement, waterproofing, air leakage of concrete slabs, and even various structures. It has various advantages such as prevention, repair, and reinforcement, and since the material used is extremely lightweight, it is easy to handle and improves work efficiency.

According to the conventionally proposed reinforcement method using carbon fiber reinforced plastic plates, as shown in FIG. Apply adhesive 3 or primer and adhesive to the slab surface,
After that, attach the carbon fiber reinforced plastic plate 2.
is required. At this time, the surface of the concrete slab is generally less flat and uneven. Therefore, if the adhesive 3 is applied to the surface of a concrete slab with a uniform thickness and a carbon fiber reinforced plastic board is attached to this surface, especially when the surface 1a to be reinforced covers a wide area, it is difficult for workers to It is extremely difficult to attach the fiber-reinforced plastic plate 2 to the reinforced surface 1a with such a pressing force, and as shown in the figure, the carbon fiber-reinforced plastic plate 2 is inclined with respect to the reinforced surface 1a of the structure. In some cases, a gap 4 where no adhesive is present may be created between the carbon fiber reinforced plastic plate 2 and the surface to be reinforced 1a.

According to such a reinforcing method, not only is it aesthetically undesirable, but the presence of the voids 4 causes a reduction in the repair and reinforcing effect of the carbon fiber reinforced plastic board 2. Similar problems also occurred when other repairs such as waterproofing and air leakage were performed other than reinforcement.

In order to eliminate the existence of such voids, the thickness of the adhesive must be increased, and the adhesive must be applied very carefully by a worker. As a result of research and experiments conducted by the present inventors, it has been found that not only does this reduce the working ratio, but also that when the thickness of the adhesive layer is made thicker than necessary, the strength in particular decreases.

Alternatively, it is possible to use a sander to polish the surface of the concrete slab to which the carbon fiber reinforced plastic plate is to be attached so that it is evenly flat, and then apply a thin layer of adhesive on top of it. Such surface treatment of concrete slabs requires a great deal of time and effort, and depending on the reinforcement location, such surface treatment may be impossible or extremely difficult, making it impractical.

Therefore, an object of the present invention is to have extremely good workability, to be able to flatly attach a carbon fiber reinforced plastic plate to the surface to be reinforced of a structure, and to have a structure in which there is no gap between the carbon fiber reinforced plastic plate and the surface to be reinforced. Reinforcement of beams, floor slabs, and other various structures of concrete structures, as well as waterproofing and air leakage of structures, which can prevent the formation of concrete structures and achieve sufficient reinforcement, repair, and various other strengthening effects. It is an object of the present invention to provide a method for strengthening a structure to suitably strengthen the structure such as prevention.

The above objectives are achieved by the method of strengthening a construct according to the present invention. In summary, the present invention involves attaching a carbon fiber-reinforced plastic plate to the surface to be reinforced of a structure via an adhesive, and then pressing the carbon fiber-reinforced plastic plate toward the surface to be reinforced by a suppressing means equipped with an air bag. The present invention is a method for reinforcing a structure, characterized in that the carbon fiber reinforced plastic plate is fixed to a surface of the structure to be reinforced. Preferably, the carbon fiber-reinforced plastic plate is installed with the distance from the surface to be reinforced of the structure adjusted to a predetermined value using a spacer, and furthermore, the air bag may have a built-in heating means,
The suppression means may include an air supply means for supplying air to the airbag, and a support member for pressing the airbag toward the carbon and fiber reinforced plastic plate.

Next, the method for reinforcing a structure according to the present invention will be explained in more detail with reference to the drawings.

First, the carbon la# reinforced plastic plate used in the present invention will be explained.

The carbon fiber reinforced plastic plate can have any structure, but for example, carbon fiber can be used as the reinforcing fiber! I (herein “
The term "carbon fiber" is used to include graphite [i]. ), a thermosetting or thermoplastic matrix resin composition is used to produce a carbon fiber reinforced prepreg in a conventional manner, cut to a predetermined size, and cured to produce a repair board.

To explain further, as the carbon fiber, pitch-based carbon Wa
Any commercially available carbon fibers such as fibers, PAN-based carbon fibers, etc. can be used, but carbon fibers with high strength and high elastic modulus, which have a tensile strength of 2.0 GPa or more and an elastic modulus of 200 GPa or more, are preferably used. Ru. Generally, diameter 7-127zm
Carbon fibers formed by bundling 3,000 to 24,000 filaments are used.

Thermosetting matrix resins constituting the matrix resin composition include epoxy resins, unsaturated polyester resins,
Polyurethane resin, diallyl phthalate resin, phenol resin, etc. can be used, and the curing temperature is 50 to 15%.
A curing agent and other imparting agents, such as a flexibility imparting agent, are appropriately selected so that the temperature is 0°C. Therefore, to give a preferable example, epoxy resin is preferable as the thermosetting resin, and usable epoxy resins include, for example, (1)
Glycidyl ether epoxy resin (bisphenol A
, F-based epoxy resin, novolac-based epoxy resin, brominated bisphenol A-based epoxy resin); (2) cycloaliphatic epoxy resin; (3) glycidyl ester-based epoxy resin; (4) glycidylamine-based epoxy resin;
(5) Heterocyclic epoxy resin; one or more selected from various other epoxy resins are used, especially:
Bisphenol A and F and glycidylamine-based epoxy resins are preferably used. Further, as the curing agent, diaminodiphenylsulfone (DDS), diaminodiphenylmethane (DDM), etc. are preferably used. Further, as the thermoplastic matrix resin, polyacetal resin, saturated polyester resin, polyamide resin, polystyrene resin, polycarbonate resin, vinyl chloride resin, polyethylene resin, polypropylene resin, acrylic resin, etc. are suitable.

Carbon fiber-reinforced plastic plates can be manufactured in a conventional manner, but briefly, long carbon fibers are continuously fed to a lower film having a predetermined width and continuously fed. For example, a thermosetting matrix resin composition having a viscosity of 100,000 to 500,000 poise is supplied to carbon fibers, and the carbon fibers are impregnated with pressure and heat using a roll or the like to a predetermined thickness, usually 0.05 to 500,000 poise. It is produced by pre-curing the film to a thickness of 0.3 mm, sandwiching it between upper cover films in a semi-cured state, and winding it up on a take-up roll. By changing the physical properties, amount and arrangement of the carbon fibers used, as well as the impregnation rate with respect to the matrix resin composition, the blending ratio of the thermosetting matrix composition to be used,
In other words, by changing the properties variously, various tensile strengths,
A carbon fiber reinforced prepreg is created that provides tensile modulus as well as toughness. Next, depending on the strength and other properties required for the repaired area, a plurality of sheets of carbon fiber reinforced prepreg having the same characteristics or a plurality of sheets of carbon fiber reinforced prepreg having different characteristics are laminated to form a 150 to 200
C. to produce a carbon fiber reinforced plastic plate with predetermined dimensions.

Next, a reinforcing method using the carbon fiber reinforced plastic plate according to the present invention will be explained.

Referring to FIG. 1, the lower surface 1a of the concrete slab 1
A method of reinforcing a concrete slab whose strength has decreased due to deterioration by attaching a carbon fiber-reinforced plastic plate 2 to the concrete slab through an adhesive 3 or through a primer (not shown) and an adhesive 3 is shown.

According to the present invention, the adhesive 3 is applied to the reinforced surface 1a of the concrete slab 1 to a predetermined thickness, either directly or after applying a primer, by performing simple cleaning if necessary. Usually, the adhesive used is a matrix resin of a carbon fiber reinforced plastic plate and an adhesive that easily stains. For example, when an epoxy resin is used as the matrix resin, an epoxy adhesive or the like is suitable as the adhesive, and an epoxy primer or the like can be used as the primer. The thickness of the adhesive 3 is usually 2 to 5 m.
It is assumed that m.

Next, after pressing one end of the carbon fiber reinforced plastic plate 2 against the concrete slab 1, the carbon fiber reinforced plastic plate 2 is then sequentially moved to the other end between the surface 1a of the concrete slab 1 and the surface of the carbon fiber reinforced plastic plate 2. The carbon fiber-reinforced plastic plate 2 is attached to the reinforced surface 1a of the concrete slab 1 while being pressed so that air is not trapped.

Next, the carbon fiber reinforced plastic plate 2 attached to the concrete slab surface 1a is pressed by the pressing means 10.

According to the present invention, the pressing means 10 includes an air bag 11, an air supply means (not shown) that supplies air to the air bag 11, and a support member that presses the air bag 11 toward the prepreg. 12. The support member 12 is preferably composed of a rigid flat plate 12a such as a carbon fiber reinforced plastic plate, and a normal sabot 12b that supports the flat plate under a predetermined pressure and is adjustable in the length direction. be. Airbags are usually 0.02~0
．． The air pressure is set to 1 kg/cm'' and is controlled by a pressure regulator 13.

Further, if necessary, heating means 15 such as a flexible planar electric heater may be provided in the airbag 11 to accelerate the curing of the adhesive 3. In this case, as shown in the figure, the airbag 11 and the flat plate 12
It is preferable to interpose a heat insulating material 16 such as an asbestos sheet between the material and the material a.

According to the present invention, in order to use the suppression means io equipped with such an airbag ll, the carbon fiber reinforced plastic plate 2 is evenly pressed against the reinforced surface 1a with a predetermined pressing force, and the Even if a small amount of air remains between the reinforcing surface and the prepreg, this air is effectively discharged by the pressing means 10.

Moreover, according to another aspect of the present invention, the concrete slab 1
In order to reliably join the carbon fiber reinforced plastic plate 2 to the reinforced surface 1a at a predetermined distance, a spacer is installed between the reinforced surface 1a and the carbon fiber reinforced plastic plate 2 as shown in FIG. 30 can be installed. Although the spacer 30 can have any structure, in this embodiment, dry bits 31 are driven into the concrete slab surface 1a at appropriate intervals, for example, at intervals of 500 mm, and spacer screws 32 are screwed into the dry bits. . The height of each spacer screw 32 is adjusted with respect to the dry bit 31 so that the end surfaces thereof are located approximately in the same plane. Next, the adhesive 3 is applied so as to be slightly thicker than the height of the spacer screw 32, and then the carbon fiber reinforced plastic plate 2 is moved toward the reinforced surface 1a by the pressing means 10 and stopped at the spacer screw 32. This state is maintained until the adhesive 3 hardens.

As mentioned above, the spacer 30 is not limited to the above configuration, but can be a cylindrical shape with a diameter of about 2 to 3 cm prepared in various heights, for example, in the range of 0.5 to 1 cm, It is also possible to form a structure in which a plurality of spacers 30 are bonded to the reinforced surface 1a to be reinforced in advance using an adhesive or the like so as to form approximately the same plane.

Further, in the above embodiment, the carbon fiber reinforced plastic plate 2 is attached to the reinforced surface on the lower surface of the structure, but the same applies when the reinforced surface is on the upper surface of the structure. It can be strengthened by the following method.

As explained above, the method for reinforcing a structure according to the present invention can press the carbon fiber-reinforced plastic plate against the surface to be reinforced with uniform pressure using an air bag, so it is extremely easy to work with. The carbon fiber reinforced plastic plate can be attached flatly to the reinforced surface of the structure, and the formation of gaps between the carbon fiber reinforced plastic plate and the reinforced surface can be prevented, allowing for sufficient repair and reinforcement. It is possible to achieve reinforcement effects such as, reinforcement of concrete structure beams, floor slabs, and various other structures, and it is also possible to suitably strengthen structures such as waterproofing structures and preventing air leaks. It has the following characteristics.

[Brief explanation of the drawing]

FIG. 1 is a process explanatory diagram illustrating a method for strengthening a construct according to the present invention. FIG. 2 is an explanatory diagram illustrating another embodiment of the method for strengthening a structure according to the present invention. FIG. 3 is an explanatory diagram illustrating a conventional method for strengthening a structure. 1: Concrete slab 2: Carbon fiber reinforced plastic plate 3: Adhesive lO: Suppression means 11: Air bag 12: Support member 30: Spacer

Claims (1)

[Claims] 1) A carbon fiber-reinforced plastic plate is attached to the surface to be reinforced of the structure via an adhesive, and then the carbon fiber-reinforced plastic plate is pushed toward the surface to be reinforced by a pressing means equipped with an air bag. A method for reinforcing a structure, which comprises pressing and fixing the carbon fiber reinforced plastic plate to a surface of the structure to be reinforced. 2) The method according to claim 1, wherein the carbon fiber reinforced plastic plate is installed with its distance from the surface to be reinforced of the structure adjusted by a spacer. 3) The air bag has a built-in heating means, and the pressing means includes an air supply means for supplying air to the air bag, and a support member for pressing the air bag toward the carbon fiber reinforced plastic plate. A method according to claim 1 or 2, comprising: