JP2016069812A - Concrete structure reinforcement method and continuous fiber sheet-containing sticking/adhesion gel sheet used in the method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for reinforcing a concrete structure with good workability.SOLUTION: A concrete structure reinforcement method is characterized by sticking a sticking/adhesion gel sheet comprising a continuous fiber sheet and an organo gel to a concrete structure for fixing the sticking/adhesion gel sheet to the concrete structure, and then curing the sticking/adhesion gel sheet for adhesion.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a method for reinforcing a concrete structure and a continuous fiber sheet-containing adhesive gel sheet used in the method. More specifically, the present invention relates to a concrete structure by firmly bonding a continuous fiber sheet-containing adhesive gel sheet to a concrete structure by adhesion, and then firmly bonding the continuous fiber sheet-containing adhesive gel sheet by curing. And a continuous fiber sheet-containing adhesive gel sheet used in this method.

In recent years, aging of concrete structures has become a social problem. Examples of the cause of aging deterioration include cold joint formation, neutralization, alkali-aggregate reaction, frost damage, salt damage, and the like of concrete, as well as poor construction.
It is necessary to reinforce concrete structures that have deteriorated over time. Examples of the reinforcing method include the method described in JP-A-10-298930 (Patent Document 1), and specifically, the reinforcing is performed according to the following procedure.

  That is, after the surface of the concrete structure is cleaned, a treatment with an impregnation material, a reinforcing steel rust preventive material, a cross-section repair material, a crack injection agent, or the like is performed depending on the degree of deterioration of the concrete structure. Next, after smoothing the surface, an adhesive is applied to the smooth surface, and a reinforcing material such as a woven fabric or a knitted fabric is stuck thereon. After pasting, the concrete structure is reinforced by drying and solidifying. Such a reinforcing method is also called a hand lay-up method.

Japanese Patent Laid-Open No. 10-298930

  Concrete structures have various shapes and sizes. Therefore, if there is a place where reinforcement is required at a high place, there is a risk in the work, and the work load becomes high if it is in a wide range. In addition, the adhesive requires curing (maintaining a state for a certain period of time) for curing, and the reinforcement work becomes long, so the construction cost increases. Furthermore, depending on the environment of the reinforcement site, quality control of the reinforcement may be difficult, and excessive reinforcement is performed in order to ensure reinforcement with a predetermined quality. In addition, since the reinforcing material adheres to the site requiring reinforcement at the site, wrinkles and air may enter depending on the skill of the operator. Therefore, reinforcement may be insufficient.

The inventors of the present invention have found that the above-mentioned problems can be solved by using an adhesive gel sheet containing a continuous fiber sheet and an organogel for reinforcing a concrete structure, and have reached the present invention.
Thus, according to the present invention, the adhesive gel sheet including the continuous fiber sheet and the organogel is adhered to the concrete structure to fix the adhesive gel sheet to the concrete structure, and then the adhesive gel sheet is A method for reinforcing a concrete structure, characterized by curing and bonding, is provided.
Further, according to the present invention, there is provided a continuous fiber sheet-containing adhesive gel sheet for reinforcing a concrete structure, which is used in the above-described method for reinforcing a concrete structure and is composed of a continuous fiber sheet and an organogel. The

  According to the method for reinforcing a concrete structure and the reinforcing adhesive gel sheet of the present invention, it is possible to reinforce the concrete structure while reducing the risk of the work, the work load, and the construction cost without depending on the skill of the operator.

Moreover, when it is based on any one or the combination below, a concrete structure can be reinforced more simply.
(1) The organogel is (1) a storage elastic modulus of 1.0 × 10 ^{3 to} 5.0 × 10 ⁴ Pa and a loss coefficient of 0.01 to 2 (at a frequency of 0.01 Hz) at 23 ° C. It has a storage modulus of 0 × 10 ^{4 to} 1.0 × 10 ⁷ Pa and a loss factor of 0.01 to 2 (at a frequency of 100 Hz), and (2) 0.01 to 0.15 N / before curing. adhesion of mm ^2, after curing, has a 3N / mm ² or more adhesion (2) continuous fiber sheets, one or two elements selected from the group consisting of woven fabric, knitted fabric, nonwoven and laminated fabrics When the sheet is composed of the above fiber base material (3) The fiber base material is selected from the group consisting of natural fiber, polyester fiber, polyamide fiber, aramid fiber, vinylon fiber, carbon fiber, glass fiber, and polyolefin fiber. When it consists of one or more fibers (4 Continuous fiber sheet, the basis weight of 10 to 1000 g / m ^2, if (5) organogel having a tensile strength of 1～7GPa, (meth) a polymeric matrix comprising an acrylate resin, a liquid curable epoxy resin And a curing agent

It is the schematic of the reinforcement form of a concrete structure.

Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings.
FIG. 1 shows an embodiment in which a continuous fiber sheet-containing adhesive gel sheet (also simply referred to as a gel sheet) for reinforcing a concrete structure is applied to the surface of the concrete structure. This reinforcement can be performed by the following procedure, for example.
First, the reinforcement required part of the concrete structure 1 is cleaned. At the time of cleaning, depending on the degree of deterioration of the concrete structure 1, a treatment with an impregnating material, a reinforcing steel rust preventive material, a cross-sectional repair material, a crack injection agent or the like may be performed. Next, after smoothing the surface as necessary, the reinforcing continuous fiber sheet-containing pressure-sensitive adhesive gel sheet 2 is fixed by adhering it to the site requiring reinforcement. Since the gel sheet 2 is fixed by adhesion, it can be easily reapplied even when it is necessary to reapply due to air entrainment, generation of wrinkles, or the like. Next, the concrete structure 1 can be reinforced by curing the gel sheet 2 and bonding it to the concrete structure 1. In FIG. 1, 3 means a continuous fiber sheet.

The gel sheet is not particularly limited as long as it has a gel-like form, predetermined adhesive strength and adhesive strength.
The thickness of a gel sheet will not be specifically limited if it is the thickness which can maintain the shape of a sheet | seat at the time of reinforcement work. For example, it is 0.5-5 mm.

In the present specification, the gel-like form means that the storage elastic modulus at a frequency of 0.01 Hz is 1.0 × 10 ^{3 to} 5.0 × 10 5 in the value of the storage elastic modulus and loss coefficient measured at 23 ° C., for example. ⁴ Pa, loss factor is 0.01 to 2, storage modulus at a frequency of 100 Hz is 1.0 × 10 ^{4 to} 1.0 × 10 ⁷ Pa, loss factor is represented by physical properties of 0.01 to 2 A form is mentioned. The storage elastic modulus and loss factor are collectively referred to as viscoelastic properties.
The viscoelastic property is an evaluation of adhesiveness in which the gel sheet enters and adheres to the irregularities on the surface of the concrete structure (adhered body), and indicates the contact area of the gel sheet to the adherend and the deformability of the gel sheet itself. The viscoelastic property is also an evaluation value of the cohesive force of the gel sheet, that is, the fracture strength.

The viscoelastic property at 0.01 Hz (low frequency range) is an index such as the wet adhesive force of the gel sheet and the creep behavior (plastic deformation) in a minute deformation process at a low speed. For example, when pasted on an adherend, if the storage elastic modulus at 0.01 Hz is too high or the loss factor is too low, the gel sheet cannot be satisfactorily deformed and adhesion may be lowered. Conversely, if the storage elastic modulus is too low or the loss factor is too high, the cohesiveness of the gel sheet may be reduced, and the shape retention may be reduced.
The viscoelastic property at 1000 Hz (high frequency range) is an indicator of the followability of the gel sheet to the adherend and the peeling behavior in a high-speed deformation process. For example, when pasted on an adherend, if the storage elastic modulus at 100 Hz is too high or the loss coefficient is too low, the gel sheet cannot follow vibrations caused by passing through a vehicle or the like, and peeling easily occurs. Conversely, if the storage elastic modulus is too low or the loss coefficient is too high, it may be difficult to reattach the adherend.

The storage elastic modulus at a frequency of 0.01 Hz is 1.0 × 10 ^{3 to} 5.0 × 10 ⁴ Pa, the loss coefficient is 0.01 to 2, and the storage elastic modulus at a frequency of 100 Hz is 1.0 × 10 ^4. It is more preferable that it is -1.0 * 10 < ⁷ > Pa and a loss coefficient is 0.01-2.
The predetermined adhesive force is a force capable of maintaining the adhesive state of the gel sheet to the concrete structure. The adhesive strength is preferably 0.01 to 0.15 N / mm ² . If it is less than 0.01 N / mm ^{2, the} adhesive strength to the adherend may not be sufficient. When it is higher than 0.15 N / mm ² , the adhesiveness is too strong and workability may be lowered. A more preferable adhesive force is 0.05 to 0.15 N / mm ² .

The predetermined adhesive force is a force capable of maintaining the adhesive state of the gel sheet to the concrete structure after the gel sheet is cured. The adhesive force is preferably 3 N / mm ² or more in terms of tensile shear adhesive strength. If it is less than 3 N / mm ² , the adhesion to the concrete structure may be lowered, and the load bearing capacity may be insufficient. A more preferable adhesive force is 5 to 20 N / mm ² .
The organogel preferably includes a polymer matrix, a liquid curable epoxy resin, and a curing agent. The polymer matrix may be composed of (meth) acrylate resin, urethane resin, acrylic silicone resin, silicone resin, or the like.

The polymer matrix can be obtained, for example, by copolymerizing a (meth) acrylate monofunctional monomer and a polyfunctional monomer. It is preferable that the monomer contains an epoxy group.
The liquid curable epoxy resin is a resin that is liquid at room temperature (about 23 ° C. ± 2 ° C.). For example, epoxy resins such as bisphenol A type, bisphenol F type, and novolak resin type can be used.

The curing agent is not particularly limited, and a heat or light curing agent can be used. When a thermosetting agent is used, the gel sheet is cured by heating, and when a photocuring agent is used, the gel sheet is cured by light irradiation. Application of heat or light to the gel sheet may be performed after the gel sheet is adhered to the concrete structure, or may be performed before the adhesion.
The gel sheet is provided with a continuous fiber sheet. By providing the continuous fiber sheet, the physical strength of the gel sheet can be increased.

  A continuous fiber sheet can be made into the sheet | seat which consists of 1 type, or 2 or more types of fiber base materials chosen from the group which consists of a woven fabric, a knitted fabric, a nonwoven fabric, and a laminated fabric, for example. The fiber base material is composed of one or more fibers selected from the group consisting of natural fibers, polyester fibers, polyamide fibers, aramid fibers, vinylon fibers, carbon fibers, glass fibers, and polyolefin fibers. Also good. Among these, polyester fiber, polyamide fiber, aramid fiber, vinylon fiber, and polyolefin fiber are preferable because they are light and excellent in strength.

The fibers may be blended, used for warp or weft, or laminated in multiple layers.
As the fiber bundle, one having a basis weight of 10 to 1000 g / m ² is usually preferable. As for the tensile strength of the said fiber, 1 GPa or more is mentioned, 2.5 GPa or more is preferable. The upper limit is not particularly limited, but is usually 7 GPa or less, preferably 6 GPa or less. Moreover, 100 GPa or more is mentioned as the tensile elasticity modulus of the said fiber, 200 GPa or more is preferable. The upper limit is not particularly limited, but is usually 1000 GPa or less, preferably 500 GPa or less.

Further, it is preferable that 0.0001 to 0.1% by mass of the silane coupling agent adhere to the fiber surface because it improves the impregnation property of the resin and improves the strength of the product. For example, an epoxy silane coupling agent, an amino silane coupling agent, a ureido silane coupling agent, a methacryl silane coupling agent, a vinyl silane coupling agent, and a styryl silane coupling agent are suitable.
The continuous fiber sheet may be located in any part of the gel sheet. For example, it may be located on the surface of the gel sheet on the side of the concrete structure, the opposite surface, or may be located inside the gel sheet. Among these, it is preferable to be located inside the gel sheet because the integrity of the gel sheet and the continuous fiber sheet can be further improved.

  The surface of the gel sheet may be protected with a pair of release films until use. Moreover, the base material (for example, synthetic resin film) may be provided on one side of the gel sheet, and the release film may be provided on the other side. Furthermore, the continuous fiber sheet may be bonded to the base material.

A production example of the gel sheet will be described below.
First, the following components are stirred and mixed until uniform to obtain an adhesive composition.

Acrylate monomer (P2H-A, manufactured by Kyoeisha Chemical) 4.5 parts by mass Epoxy acrylate oligomer (SP1509, manufactured by Showa Denko) 10.5 parts by mass Photopolymerization initiator (Irgacure 1173, manufactured by BASF) 0.3 parts by mass Liquid bisphenol A type epoxy resin (jER828, manufactured by Mitsubishi Chemical Corp.) 100 parts by mass Latent type curing agent (Fujicure 7001, manufactured by T & K TOKA) 10 parts by mass PET film coated with silicone with the resulting adhesive composition ( An aramid fiber mesh (manufactured by Fivex) AKM-10 / 10 basis weight 180 g / m ² ) is placed on the release film as a core material (continuous fiber sheet), and poured from above. Thereafter, the same silicone-coated PET film is covered from above, and the adhesive composition is evenly spread so that the thickness of the adhesive composition between the pair of films becomes 2.0 mm. Subsequently, a gel sheet having a thickness of 2.0 mm can be obtained by irradiating ultraviolet rays having an energy amount of 7500 mJ from a metal halide lamp.
This gel sheet has an adhesive strength of 0.125 N / mm ² , a storage elastic modulus of 7620 Pa and a loss factor of 0.36 at a frequency of 0.01 Hz, a storage elastic modulus of 927700 Pa and a loss factor of 0.45 at a frequency of 100 Hz. Further, after curing, the tensile shear bond strength is 8.28 N / mm ² . In addition, the measuring method of these physical properties is described below.

(Adhesion measurement: probe tack test)
The gel sheet is cut into 3 × 3 cm and attached to a SUS plate fixed with a double-sided tape (Sliontec No. 5486) with one side of the gel sheet to be measured facing up, and the other side is used to attach the gel sheet. The probe tack test is measured using a texture analyzer TX-AT (manufactured by Eihiro Seiki Co., Ltd.). A SUS probe having a diameter of 10 mm is used as the probe. After applying the load to the adhesive surface of the probe for 10 seconds with a load of 1000 g, the maximum load (N) when the probe is peeled off at a speed of 10 mm / sec is measured. The adhesive force is a value (N / mm ² ) obtained by dividing the maximum load (N) by the area of the adhesive surface.

[Measuring method of dynamic viscoelasticity (storage modulus G ′ and loss coefficient tan δ)]
The dynamic viscoelasticity measurement is performed using a viscoelasticity measuring apparatus PHYSICA MCR301 (manufactured by Anton Paar), a temperature control system CTD450, analysis software Rheoplus, and a geometry processing parallel plate of φ8 mm for the geometry.
A disc-shaped gel sheet test piece having a diameter of 10 mm and a thickness of 2 mm is sandwiched between plates of a viscoelasticity measuring apparatus having a measurement temperature, and the distance between the plates is adjusted so that a normal force is 0.05N.
Further, after maintaining the measurement temperature ± 1 ° C. for 2 minutes, the strain is set to 1%, the frequency is 0.1 to 100 Hz, the temperature condition is 23 ° C., the nitrogen atmosphere, and the normal force is 1N.
Next, measurement is performed from the high frequency (100 Hz) side in the frequency range of 0.1 Hz to 100 Hz. The storage elastic modulus G ′ and the loss coefficient tan δ are measured by performing dynamic viscoelasticity measurement under the condition of logarithmic elevation and the number of measurement points of 5 points / digit.

(Adhesive strength measurement)
The gel sheet is cut into a size of 25 mm × 12.5 mm, and one of the two release films of the gel sheet is peeled off. After the alcohol cleaning, the gel sheet exposed to the SPCC steel plate polished with No. 240 polishing paper described in JIS R 6252: 2006 is pressure-bonded. The other release film is then peeled off and the exposed gel sheet is crimped to another similarly pretreated SPCC steel plate. A test piece for measuring the tensile shear bond strength is obtained by heating and curing at 120 ° C. for 2 hours in a blown oven, and then allowing to cool at room temperature.

Next, using the tensile tester Tensilon universal testing machine UCT-10T (manufactured by Orientec Co., Ltd.) and universal testing machine data processing software UTPS-458X (manufactured by Softbrain Corporation), the test piece is in accordance with the procedure of JIS K6850: 1999, JIS K 7100: 1999 symbol “23/50” (temperature: 23 ° C., relative humidity: 50%), after conditioning for over 16 hours under a second grade standard atmosphere, and tensile shear bond strength under the same standard atmosphere (N / mm ² ) is measured. However, the tensile speed is 1.0 ± 0.2 (mm / min) in accordance with Japan Adhesive Industry Association Standard JAI-15: 2011.
The tensile shear bond strength (N / mm ² ) is calculated by the following formula.

S = P / A
S: Tensile shear bond strength (N / mm ² )
P: Breaking force (N)
A: Shear area (mm ² )

1: Concrete structure 2: Reinforced continuous fiber sheet-containing adhesive gel sheet 3: Continuous fiber sheet

Claims (7)

Fixing the adhesive gel sheet to the concrete structure by adhering the adhesive gel sheet containing the continuous fiber sheet and the organogel to the concrete structure, and then curing the adhesive gel sheet to adhere A method for reinforcing concrete structures. The organogel has (1) a storage elastic modulus of 1.0 × 10 ^{3 to} 5.0 × 10 ⁴ Pa and a loss coefficient of 0.01 to 2 (at a frequency of 0.01 Hz) at 23 ° C., 1.0 × It has a storage modulus of 10 ^{4 to} 1.0 × 10 ⁷ Pa and a loss factor of 0.01 to 2 (at a frequency of 100 Hz), and (2) 0.01 to 0.15 N / mm ² before curing. The method for reinforcing a concrete structure according to claim 1, which has an adhesive strength of 3 N / mm ² or more after curing. The concrete structure according to claim 1 or 2, wherein the continuous fiber sheet is a sheet composed of one or more fiber base materials selected from the group consisting of woven fabric, knitted fabric, non-woven fabric, and laminated fabric. Reinforcement method. The said fiber base material consists of 1 type, or 2 or more types of fibers chosen from the group which consists of natural fiber, polyester fiber, polyamide fiber, aramid fiber, vinylon fiber, carbon fiber, glass fiber, and polyolefin fiber. A method for reinforcing a concrete structure as described in 1. The method for reinforcing a concrete structure according to any one of claims 1 to 4, wherein the continuous fiber sheet has a basis weight of 10 to 1000 g / m ² and a tensile strength of 1 to 7 GPa. The method for reinforcing a concrete structure according to any one of claims 1 to 5, wherein the organogel includes a polymer matrix made of a (meth) acrylate resin, a liquid curable epoxy resin, and a curing agent. It is used for the reinforcement method of the concrete structure as described in any one of Claims 1-6, and is comprised from the continuous fiber sheet and organogel, The continuous fiber sheet containing adhesive for reinforcement of the concrete structure characterized by the above-mentioned Gel sheet.

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