JP6849540B2 - Concrete surface protection / peeling prevention method and concrete surface protection / peeling prevention structure - Google Patents

Description

The present invention relates to a concrete surface protection / peeling prevention method for protecting the concrete surface with a sheet member and a concrete surface protection / peeling prevention structure.

When a polyester resin sheet (impermeable sheet) is applied to the surface of a concrete structure using a modified silicone-epoxy adhesive, and the temperature of the concrete structure rises due to the effects of sunlight, etc., concrete Moisture contained in the structure volatilizes and becomes water vapor, which may affect the construction part (sheet pasting part).

At this time, the pressure (back pressure) of the generated water vapor is applied to the back surface of the sheet (uncured adhesive portion), so that the sheet may peel off from the surface of the concrete and so-called floating may occur. The occurrence of such sheet floating depends on the pressure of water vapor released from concrete, which fluctuates due to the passage of time, temperature rise due to solar radiation, and the like.

For example, Patent Documents 1 and 2 disclose a method of preventing the sheet from floating by forming a sheet-shaped reinforcing body using a water-permeable material and releasing water vapor generated from concrete to the atmosphere.

Further, for example, Patent Document 3 discloses a method in which a groove communicating with the atmosphere is provided in the adhesive layer of the sheet, and a method of preventing the sheet from floating by releasing water vapor generated from concrete to the atmosphere is provided. There is.

Further, for example, Patent Document 4 discloses a method of preventing floating of a sheet by laminating a breathable sheet between a sheet and an object to be attached and releasing water vapor generated from concrete to the atmosphere. Has been done.

Further, for example, Patent Document 5 discloses a method of preventing the coating from floating by densifying the surface of concrete to make it non-permeable and moisture-permeable and then applying coating.

Japanese Unexamined Patent Publication No. 2011-32694 Japanese Unexamined Patent Publication No. 10-196115 Japanese Unexamined Patent Publication No. 2000-186254 Japanese Unexamined Patent Publication No. 10-306553 Japanese Unexamined Patent Publication No. 2009-68277

However, the above-mentioned conventional method has the following problems.
That is, in the method disclosed in Patent Documents 1 and 2, in the adhesive of the mesh sheet (moisture permeable), the water vapor in the concrete passes through the adhesive and the sheet and is released to the atmosphere due to the moisture permeability of the adhesive. Will be done. However, since the polyester-based resin sheet is a moisture-impermeable sheet, water vapor does not permeate it, and it may stay inside the sheet and cause the sheet to float.

Further, in the method disclosed in Patent Document 3, since the adhesive layer is provided with a groove communicating with the atmosphere, the contact area between the concrete and the adhesive may be reduced, and the adhesive strength may be lowered.

Further, in the method disclosed in Patent Document 4, since the breathable sheet is laminated between the sheet and the object to be attached, the structure of the sheet is increased by one element. Therefore, if the number of construction steps is increased by one, there is a problem of deterioration of workability and workability.

Further, in the method disclosed in Patent Document 5, the densification of the surface of concrete depends on the properties of the concrete to be constructed, and the effect changes depending on the properties of the concrete. Therefore, the quality of concrete is extremely low, and the effect may not be sufficient for concrete having porous properties.

The subject of the present invention is a concrete surface protection / peeling prevention method and a concrete surface protection / peeling prevention structure capable of effectively preventing the occurrence of floating of a sheet while ensuring adhesive strength and workability. To provide.

The concrete surface protection / peeling prevention method according to the first invention is a concrete surface protection / peeling prevention method for protecting the surface of a concrete structure by attaching a protective sheet to the surface of the protective sheet or the concrete structure. It is provided with a step of applying an adhesive to the concrete structure and a step of attaching a protective sheet to the surface of the concrete structure via the adhesive. The parameter α obtained by dividing the flexural rigidity of the protective sheet by the viscosity of the adhesive satisfies the following relational expression (1).

2.8 ≤ α ≤ 17.0 (1)
Here, in the concrete surface protection / peeling prevention method for protecting the surface of a concrete structure by attaching a protective sheet, the flexural rigidity of the protective sheet attached to the concrete structure is divided by the viscosity of the adhesive. Set the parameter α so that it falls within a predetermined range.

As the protective sheet attached with an adhesive for protecting the surface of the concrete structure and preventing peeling, for example, a polyester resin sheet or the like can be used. Further, as the adhesive, for example, a modified silicone-epoxy adhesive or the like can be used.

Here, when the flexural rigidity (sheet elastic modulus × sheet thickness) of the protective sheet is increased, the deformation of the sheet does not follow according to the water vapor locally generated due to the moisture contained in the concrete. Therefore, the effect of suppressing the occurrence of floating of the protective sheet can be expected. However, when the flexural rigidity of the protective sheet is high, the flexibility is impaired, so that the adhesive may resist the viscosity of the adhesive, and the springback may cause floating or peeling.

On the other hand, in order to suppress the floating and peeling of the protective sheet due to springback, it is necessary to increase the viscosity of the adhesive, but the adhesive with high viscosity has a problem that workability is lowered in the process of applying it to concrete. is there. On the contrary, if the viscosity of the adhesive is lowered, the workability of the coating process is improved, but only the protective sheet having low bending rigidity can be attached. In this case, the water vapor generated from the concrete deforms the adhesive and pushes up the protective sheet, which may cause the protective sheet to float.

For example, when an impermeable sheet such as a polyester resin sheet is attached to a concrete wall surface as a protective sheet, in order to suppress the occurrence of floating of the protective sheet, the bending rigidity of the protective sheet and the viscosity of the adhesive are determined. The balance needs to be optimized.

Therefore, in the present invention, the value (α value) obtained by dividing the flexural rigidity of the protective sheet by the viscosity of the adhesive is set in the above range.

As a result, by optimizing the value of the above parameter α, the balance between the flexural rigidity of the protective sheet and the viscosity of the adhesive is taken into consideration, and the adhesive strength and workability are ensured while the protective sheet is lifted. It can be effectively prevented.

The concrete surface protection / peeling prevention method according to the second invention is the concrete surface protection / peeling prevention method according to the first invention, and the viscosity of the adhesive is 250,000 to 1.25 million (mPa · s). Is.

Here, the viscosity of the adhesive used to attach the protective sheet to the surface of the concrete structure is defined within a predetermined range.

As a result, even when the surface of the concrete structure is covered with a protective sheet having a relatively high bending rigidity, it is possible to effectively prevent the protective sheet from floating while ensuring the adhesiveness of the protective sheet.

The concrete surface protection / peeling prevention method according to the third invention is the concrete surface protection / peeling prevention method according to the second invention, and the viscosity of the adhesive is 300,000 to 800,000 (mPa · s). Is.

Here, a more preferable range is defined as the viscosity of the adhesive used for attaching the protective sheet to the surface of the concrete structure.

As a result, even when the surface of the concrete structure is covered with a protective sheet having a relatively high bending rigidity, it is possible to more effectively prevent the protective sheet from floating while ensuring the adhesiveness of the protective sheet. ..

The concrete surface protection / peeling prevention method according to the fourth invention is the concrete surface protection / peeling prevention method according to any one of the first to third inventions, and the bending rigidity of the protective sheet is 352. It is ~ 884 (GPa · μm).

Here, the flexural rigidity of the protective sheet attached to the surface of the concrete structure is defined within a predetermined range.

As a result, even when the surface of the concrete structure is covered with a protective sheet having a relatively high flexural rigidity, the protective sheet is protected while ensuring the adhesiveness by using an adhesive having a relatively high viscosity. It is possible to effectively prevent the occurrence of floating of the sheet.

The concrete surface protection / peeling prevention method according to the fifth invention is the concrete surface protection / peeling prevention method according to the fourth invention, and the thickness of the protective sheet is 75 to 188 (μm).

Here, the thickness of the protective sheet to be attached to the surface of the concrete structure is defined within a predetermined range.

As a result, even when the surface of the concrete structure is covered with a protective sheet that is thick and has a relatively high flexural rigidity, the adhesiveness of the protective sheet can be increased by using an adhesive having a relatively high viscosity. It is possible to more effectively prevent the occurrence of floating of the protective sheet while ensuring the above.

The concrete surface protection / peeling prevention method according to the sixth invention is the concrete surface protection / peeling prevention method according to any one of the first to fifth inventions, and the protective sheet is a non-breathable sheet. Is.

Here, a non-permeable sheet is used as an example of a protective sheet attached to the surface of a concrete structure.

Here, as the non-moisture permeable sheet, for example, a polyester-based resin sheet or the like can be used.

This protects the water vapor generated by the moisture contained in the concrete structure by optimizing the balance between the flexural rigidity of the protective sheet and the viscosity of the adhesive even when it is covered with a non-moisture permeable sheet. It is possible to prevent the occurrence of floating while ensuring the adhesiveness of the sheet.

The concrete surface protection / peeling prevention method according to the seventh invention is the concrete surface protection / peeling prevention method according to any one of the first to sixth inventions, and the adhesive is a modified silicone-epoxy. It is a based resin.

Here, a modified silicone-epoxy resin is used as an example of an adhesive used for attaching a protective sheet to the surface of a concrete structure.

As a result, even when the water vapor generated by the moisture contained in the concrete structure locally pushes up the protective sheet, the viscosity of the modified silicone-epoxy resin is adjusted to adjust the bending rigidity of the protective sheet and the viscosity of the adhesive. By optimizing the balance with, it is possible to prevent the occurrence of floating while ensuring the adhesiveness of the protective sheet.

The concrete surface protection / peeling prevention structure according to the eighth invention is a concrete surface protection / peeling prevention structure that is protected by attaching a protective sheet to the surface of the concrete structure. It includes an adhesive that adheres the concrete structure and the protective sheet, and a protective sheet that is attached to the surface of the concrete structure via the adhesive. The parameter α obtained by dividing the flexural rigidity of the protective sheet by the viscosity of the adhesive satisfies the following relational expression (1).

2.8 ≤ α ≤ 17.0 (1)
Here, in the concrete surface protection / peeling prevention structure that protects the surface of the concrete structure by attaching a protective sheet, the flexural rigidity of the protective sheet attached to the concrete structure is divided by the viscosity of the adhesive to obtain the value. The parameter α to be obtained is set so as to be within a predetermined range.

As the protective sheet attached with an adhesive for protecting the surface of the concrete structure and preventing peeling, for example, a polyester resin sheet or the like can be used. Further, as the adhesive, for example, a modified silicone-epoxy adhesive or the like can be used.

Here, when the flexural rigidity (sheet elastic modulus × sheet thickness) of the protective sheet is increased, the deformation of the sheet does not follow according to the water vapor locally generated due to the moisture contained in the concrete. Therefore, the effect of suppressing the occurrence of floating of the protective sheet can be expected. However, when the flexural rigidity of the protective sheet is high, the flexibility is impaired, so that the adhesive may resist the viscosity of the adhesive, and the springback may cause floating or peeling.

On the other hand, in order to prevent the protective sheet from floating or peeling due to springback, it is necessary to increase the viscosity of the adhesive, but the adhesive with high viscosity has a problem that workability is reduced in the process of applying it to concrete. is there. On the contrary, if the viscosity of the adhesive is lowered, the workability of the coating process is improved, but only the protective sheet having low bending rigidity can be attached. In this case, the water vapor generated from the concrete deforms the adhesive and pushes up the protective sheet, which may cause the protective sheet to float.

For example, when an impermeable sheet such as a polyester resin sheet is attached to a concrete wall surface as a protective sheet, in order to suppress the occurrence of floating of the protective sheet, the bending rigidity of the protective sheet and the viscosity of the adhesive are determined. The balance needs to be optimized.

Therefore, in the present invention, the value (α value) obtained by dividing the flexural rigidity of the protective sheet by the viscosity of the adhesive is set in the above range.

As a result, by optimizing the value of the above parameter α, the balance between the flexural rigidity of the protective sheet and the viscosity of the adhesive is taken into consideration, and the adhesive strength and workability are ensured while the protective sheet is lifted. It can be effectively prevented.

The concrete surface protection / peeling prevention structure according to the ninth invention is the concrete surface protection / peeling prevention structure according to the eighth invention, and the viscosity of the adhesive is 250,000 to 1.25 million (mPa. s).

Here, the viscosity of the adhesive used to attach the protective sheet to the surface of the concrete structure is defined within a predetermined range.

As a result, even when the surface of the concrete structure is covered with a protective sheet having a relatively high bending rigidity, it is possible to effectively prevent the protective sheet from floating while ensuring the adhesiveness of the protective sheet.

The concrete surface protection / peeling prevention structure according to the tenth invention is the concrete surface protection / peeling prevention structure according to the ninth invention, and the viscosity of the adhesive is 300,000 to 800,000 (mPa. s).

A more preferable range is defined as the viscosity of the adhesive used for attaching the protective sheet to the surface of the concrete structure.

As a result, even when the surface of the concrete structure is covered with a protective sheet having a relatively high bending rigidity, it is possible to more effectively prevent the protective sheet from floating while ensuring the adhesiveness of the protective sheet. ..

The concrete surface protection / peeling prevention structure according to the eleventh invention is the concrete surface protection / peeling prevention structure according to any one of the eighth to tenth inventions, and the bending rigidity of the protective sheet is high. , 352-884 (GPa · μm).

Here, the flexural rigidity of the protective sheet attached to the surface of the concrete structure is defined within a predetermined range.

As a result, even when the surface of the concrete structure is covered with a protective sheet having a relatively high flexural rigidity, the protective sheet is protected while ensuring the adhesiveness by using an adhesive having a relatively high viscosity. It is possible to effectively prevent the occurrence of floating of the sheet.

The concrete surface protection / peeling prevention structure according to the twelfth invention is the concrete surface protection / peeling prevention structure according to the eleventh invention, and the thickness of the protective sheet is 75 to 188 (μm). ..

Here, the thickness of the protective sheet to be attached to the surface of the concrete structure is defined within a predetermined range.

As a result, even when the surface of the concrete structure is covered with a protective sheet that is thick and has a relatively high flexural rigidity, the adhesiveness of the protective sheet can be increased by using an adhesive having a relatively high viscosity. It is possible to more effectively prevent the occurrence of floating of the protective sheet while ensuring the above.

The concrete surface protection / peeling prevention structure according to the thirteenth invention is the concrete surface protection / peeling prevention structure according to any one of the eighth to twelfth inventions, and the protective sheet is non-transparent. It is a wet sheet.

Here, a non-transparent sheet is used as an example of a protective sheet attached to the surface of a concrete structure.

Here, as the non-moisture permeable sheet, for example, a polyester-based resin sheet or the like can be used.

This protects the water vapor generated by the moisture contained in the concrete structure by optimizing the balance between the flexural rigidity of the protective sheet and the viscosity of the adhesive even when it is covered with a non-moisture permeable sheet. It is possible to prevent the occurrence of floating while ensuring the adhesiveness of the sheet.

The concrete surface protection / peeling prevention structure according to the fourteenth invention is a concrete surface protection / peeling prevention structure according to any one of the eighth to thirteenth inventions, and the adhesive is a modified silicone. -Epoxy resin.

Here, a modified silicone-epoxy resin is used as an example of an adhesive used for attaching a protective sheet to the surface of a concrete structure.

As a result, even when the water vapor generated by the moisture contained in the concrete structure pushes up the protective sheet locally, the viscosity of the modified silicone-epoxy resin is adjusted to adjust the bending rigidity of the protective sheet and the viscosity of the adhesive. By optimizing the balance with, it is possible to prevent the occurrence of floating while ensuring the adhesiveness of the protective sheet.

According to the concrete surface protection / peeling prevention method according to the present invention, it is possible to effectively prevent the occurrence of floating of the sheet while ensuring the adhesive strength and workability.

The cross-sectional view which shows the structure of the surface protection / peeling prevention structure manufactured by the concrete surface protection / peeling prevention method which concerns on one Embodiment of this invention. The flowchart which shows the process flow of the concrete surface protection / peeling prevention construction method which concerns on one Embodiment of this invention. In Example 1 of the present invention, when the thickness of the protective sheet shown in FIG. 1 is 188 μm, the flexural rigidity of the sheet, the viscosity of the adhesive, the presence or absence of floating when the α value is changed, and the experimental results of workability. The figure which shows. In Example 2 of the present invention, when the thickness of the protective sheet shown in FIG. 1 is 125 μm, the flexural rigidity of the sheet, the viscosity of the adhesive, the presence or absence of floating when the α value is changed, and the experimental results of workability. The figure which shows. In Example 3 of the present invention, when the thickness of the protective sheet shown in FIG. 1 is 100 μm, the flexural rigidity of the sheet, the viscosity of the adhesive, the presence or absence of floating when the α value is changed, and the experimental results of workability. The figure which shows. In Example 4 of the present invention, the experimental results of the flexural rigidity of the protective sheet shown in FIG. 1 when the thickness of the protective sheet is 75 μm, the viscosity of the adhesive, the presence or absence of floating when the α value is changed, and the workability are shown. The figure which shows.

The concrete surface protection / peeling prevention method and the concrete surface protection / peeling prevention structure (surface protection / peeling prevention structure 10) according to the embodiment of the present invention will be described below with reference to FIGS. 1 and 2. It's a street.

<Structure of concrete surface protection / peeling prevention structure 10>
As shown in FIG. 1, the surface protection / peeling prevention structure (concrete surface protection / peeling prevention structure) 10 manufactured by the concrete surface protection / peeling prevention method according to the present embodiment is the concrete structure 11 and the concrete structure 11. A protective sheet 12 and an adhesive 13 are provided.

The concrete structure 11 is a structure made of concrete whose surface is protected by a non-breathable protective sheet 12. Then, in the concrete structure 11, as shown in FIG. 1, water vapor W1 generated due to the moisture contained therein is generated.

Therefore, in the surface protection / peeling prevention structure 10 of the present embodiment, the occurrence of so-called floating, in which the protective sheet 12 is lifted by the water vapor W1 generated between the surface 11a of the concrete structure 11 and the protective sheet 12, is suppressed. ..

The protective sheet 12 is, for example, a polyester-based non-breathable resin sheet, and is arranged so as to cover the surface 11a of the concrete structure 11 as shown in FIG. Then, the protective sheet 12 is attached to the surface 11a of the concrete structure 11 via the adhesive 13.

As the protective sheet 12, a resin sheet having a DLC (Diamond-Like Carbon) film formed on the surface of a PET (Polyethylene terephthalate) sheet may be used. As a result, the concrete structure can be protected by attaching a resin sheet having excellent weather resistance to the surface.

Further, in the present embodiment, it is preferable to use a sheet having a bending rigidity in the range of 352 to 884 (GPa · μm) as the protective sheet 12. Further, as the protective sheet 12, it is preferable to use a sheet having a thickness in the range of 75 to 188 μm according to the range of the flexural rigidity.

The adhesive 13 is, for example, a modified silicone-epoxy adhesive, and is arranged between the surface 11a of the concrete structure 11 and the protective sheet 12 as shown in FIG. Then, the adhesive 13 attaches the protective sheet 12 to the surface 11a of the concrete structure 11.

Here, in the present embodiment, it is preferable to use the adhesive 13 having a relatively high viscosity in the range of 250,000 to 1.25 million (mPa · s). Further, it is more preferable to use the adhesive 13 having a viscosity in the range of 300,000 to 800,000 (mPa · s).

Further, in the surface protection / peeling prevention structure 10 of the present embodiment, the value of the parameter α calculated by dividing the bending elasticity of the protective sheet 12 described above by the viscosity of the adhesive 13 is the following relational expression (1). ) Is set to be satisfied.

2.8 ≤ α ≤ 17.0 ... (1)
The value of α can be obtained by the following relational expression (2).

α = Viscosity of adhesive 13 (mPa · s) / Flexural rigidity of protective sheet 12 (GPa · μm) ・ ・ ・ ・ (2)
As a result, by optimizing the value of the parameter α, the balance between the flexural rigidity of the protective sheet 12 and the viscosity of the adhesive 13 is taken into consideration, and the adhesive strength and workability are ensured while the protective sheet 12 floats. Can be effectively prevented.

<Flow of concrete surface protection / peeling prevention method>
The concrete surface protection / peeling prevention method of the present invention will be described below using the flowchart of FIG.

That is, as shown in FIG. 2, in step S11, a protective sheet 12 for covering and protecting the surface 11a of the concrete structure 11 is prepared (preparation step).

Next, in step S12, the adhesive 13 is applied to the surface 11a of the concrete structure 11, or the adhesive 13 is applied to the back surface side of the protective sheet 12 (the side facing the surface 11a of the concrete structure 11) (the side facing the surface 11a of the concrete structure 11). Adhesive application process).

Next, in step S13, the protective sheet 12 coated with the adhesive 13 on the back surface side is put on the surface 11a of the concrete structure 11 and attached (sheet pasting step).

Next, in step S14, the adhesive 13 is cured for a predetermined time until it is cured (adhesive curing step).

As described above, the concrete surface protection / peeling prevention method of the present embodiment is a method of attaching the protective sheet 12 to the surface 11a of the concrete structure 11 to protect the concrete structure 11 or the concrete structure 11. A step S12 for applying the adhesive 13 to the surface 11a and a step S13 for attaching the protective sheet 12 to the surface 11a of the concrete structure 11 via the adhesive 13 are provided. Then, the parameter α obtained by dividing the flexural rigidity of the protective sheet 12 by the viscosity of the adhesive 13 satisfies the following relational expression (1).

2.8 ≤ α ≤ 17.0 (1)
As a result, by optimizing the value of the parameter α, the balance between the flexural rigidity of the protective sheet 12 and the viscosity of the adhesive 13 is taken into consideration, and the adhesive strength and workability are ensured while the protective sheet 12 floats. Can be effectively prevented.

<Example>
In the following, the presence or absence of floating of the protective sheet 12 and the presence or absence of deterioration of the workability of applying the adhesive 13 when the surface protection / peeling prevention structure 10 is manufactured by the method described in the above embodiment will be described. In the following Examples 1 to 4 (Each Example 1 to Example 8), the results of verification from the viewpoint of the viscosity of the adhesive 13 and the flexural rigidity of the protective sheet 12 are shown.

Specifically, in Examples 1 to 4, the thickness of the protective sheet 12, the viscosity of the adhesive 13, the flexural rigidity of the protective sheet 12 / the viscosity of the adhesive 13 (α value), the presence or absence of floating, and the workability evaluation result. Is shown.

The elastic modulus (GPa) of the following protective sheet 12 conforms to the ASTM D882 standard. The viscosity of the adhesive 13 is measured in accordance with JIS Z 8803 (method for measuring viscosity of liquid) standard, and is measured using a B-type viscometer No. 7 rotor.

In this embodiment, as shown in FIG. 3, when the protective sheet 12 has a thickness of 188 μm and a flexural rigidity of 883.6 (GPa · μm), the value of the parameter α, the presence / absence of floating, and the presence / absence of deterioration in workability. The result of verifying the relationship with is shown.

That is, in this embodiment, when the thickness (α value) of the adhesive 13 is changed in 8 steps when the thickness of the protective sheet 12 is 188 μm, that is, the bending rigidity is constant at 883.6 (GPa · μm). We are verifying the presence or absence of floating and the presence or absence of deterioration in workability.

Specifically, in Examples 1 to 8 was changed in eight steps viscosity of the adhesive ^{13 20,35,50,65,80,95,110,125 (× 10 4 mPa ·} s).

Along with this, the α value changed to 44.18, 25.25, 17.67, 13.59, 11.05, 9.30, 8.03, 7.07 in Examples 1 to 8. ..

As a result, in the case of Example 1 (α value = 44.18), the protective sheet 12 did not float. On the other hand, regarding the workability when applying the adhesive 13, the workability was deteriorated because the bending rigidity of the protective sheet 12 was too large (the α value was too large).

Further, in the case of Example 2 (α value = 25.25), the protective sheet 12 did not float. On the other hand, regarding the workability when applying the adhesive 13, the workability was deteriorated because the bending rigidity of the protective sheet 12 was too large (the α value was too large).

Further, in the case of Example 3 (α value = 17.67), the protective sheet 12 did not float. On the other hand, regarding the workability when applying the adhesive 13, the workability was deteriorated because the bending rigidity of the protective sheet 12 was too large (the α value was too large).

Further, in the case of Example 4 (α value = 13.59), the protective sheet 12 did not float, and the workability when applying the adhesive 13 was not deteriorated.

Further, in the case of Example 5 (α value = 11.05), the protective sheet 12 did not float, and the workability when applying the adhesive 13 was not deteriorated.

Further, in the case of Example 6 (α value = 9.30), the protective sheet 12 did not float, and the workability when applying the adhesive 13 was not deteriorated.

Further, in the case of Example 7 (α value = 8.03), the protective sheet 12 did not float, and the workability when applying the adhesive 13 was not deteriorated.

Further, in the case of Example 8 (α value = 7.07), the protective sheet 12 did not float, and the workability when applying the adhesive 13 was not deteriorated.

As described above, as a result of Examples 1 to 8 included in Example 1, if the range is within the range of 7.07 ≤ α ≤ 13.59, the protective sheet 12 does not float and the adhesive 13 is applied. It was found that there was no decrease in workability when doing this.

In this embodiment, as shown in FIG. 4, when the protective sheet 12 has a thickness of 125 μm and a flexural rigidity of 587.5 (GPa · μm), the value of the parameter α, the presence / absence of floating, and the presence / absence of deterioration in workability. The result of verifying the relationship with is shown.

That is, in this embodiment, when the thickness (α value) of the adhesive 13 is changed in 8 steps when the thickness of the protective sheet 12 is 125 μm, that is, the bending rigidity is constant at 587.5 (GPa · μm). We are verifying the presence or absence of floating and the presence or absence of deterioration in workability.

Specifically, in Examples 1 to 8, in the same manner as in Example 1, the viscosity of the adhesive 13 20,35,50,65,80,95,110,125 and ^{(× 10 4 mPa · s)} 8 It was changed in stages.

Along with this, the α value changed to 29.38, 16.79, 11.75, 9.04, 7.34, 6.18, 5.34, 4.70 in Examples 1 to 8. ..

As a result, in the case of Example 1 (α value = 29.38), the viscosity of the adhesive is too small (the α value is too large) with respect to the flexural rigidity of the protective sheet 12, so that the protective sheet 12 floats. Occurred. On the other hand, regarding the workability when applying the adhesive 13, no decrease in workability was observed.

Further, in the case of Example 2 (α value = 16.79), the protective sheet 12 did not float, and the workability when applying the adhesive 13 was not deteriorated.

Further, in the case of Example 3 (α value = 11.75), the protective sheet 12 did not float, and the workability when applying the adhesive 13 was not deteriorated.

Further, in the case of Example 4 (α value = 9.04), the protective sheet 12 did not float, and the workability when applying the adhesive 13 was not deteriorated.

Further, in the case of Example 5 (α value = 7.34), the protective sheet 12 did not float, and the workability when applying the adhesive 13 was not deteriorated.

Further, in the case of Example 6 (α value = 6.18), the protective sheet 12 did not float, and the workability when applying the adhesive 13 was not deteriorated.

Further, in the case of Example 7 (α value = 5.34), the protective sheet 12 did not float, and the workability when applying the adhesive 13 was not deteriorated.

Further, in the case of Example 8 (α value = 4.70), the protective sheet 12 did not float, and the workability when applying the adhesive 13 was not deteriorated.

As described above, as a result of Examples 1 to 8 included in Example 2, if the range is 4.70 ≦ α ≦ 16.79, the protective sheet 12 does not float and the adhesive 13 is applied. It was found that there was no decrease in workability when doing this.

In this embodiment, as shown in FIG. 5, the value of the parameter α when the thickness of the protective sheet 12 is 100 μm and the flexural rigidity is 470 (GPa · μm), the presence / absence of floating, and the presence / absence of deterioration in workability. The result of verifying the relationship is shown.

That is, in this embodiment, when the thickness of the protective sheet 12 is 100 μm, that is, the bending rigidity is constant at 470 (GPa · μm), the adhesive 13 floats when the viscosity (α value) is changed in eight steps. We are verifying whether or not it has occurred and whether or not workability has deteriorated.

Specifically, in Examples 1 to 8, in the same manner as in Example 1, the viscosity of the adhesive 13 20,35,50,65,80,95,110,125 and ^{(× 10 4 mPa · s)} 8 It was changed in stages.

Along with this, the α value changed to 23.5, 13.43, 9.40, 7.23, 5.88, 4.95, 4.27, 3.76 in Examples 1 to 8. ..

As a result, in the case of Example 1 (α value = 23.5), the viscosity of the adhesive is too small (the α value is too large) with respect to the flexural rigidity of the protective sheet 12, so that the protective sheet 12 floats. Occurred. On the other hand, regarding the workability when applying the adhesive 13, no decrease in workability was observed.

Further, in the case of Example 2 (α value = 13.43), the protective sheet 12 did not float, and the workability when applying the adhesive 13 was not deteriorated.

Further, in the case of Example 3 (α value = 9.40), the protective sheet 12 did not float, and the workability when applying the adhesive 13 was not deteriorated.

Further, in the case of Example 4 (α value = 7.23), the protective sheet 12 did not float, and the workability when applying the adhesive 13 was not deteriorated.

Further, in the case of Example 5 (α value = 5.88), the protective sheet 12 did not float, and the workability when applying the adhesive 13 was not deteriorated.

Further, in the case of Example 6 (α value = 4.95), the protective sheet 12 did not float, and the workability when applying the adhesive 13 was not deteriorated.

Further, in the case of Example 7 (α value = 4.27), the protective sheet 12 did not float, and the workability when applying the adhesive 13 was not deteriorated.

Further, in the case of Example 8 (α value = 3.76), the protective sheet 12 did not float, and the workability when applying the adhesive 13 was not deteriorated.

As described above, as a result of Examples 1 to 8 included in Example 3, if the range is 3.76 ≤ α ≤ 13.43, the protective sheet 12 does not float and the adhesive 13 is applied. It was found that there was no decrease in workability when doing this.

In this embodiment, as shown in FIG. 6, when the protective sheet 12 has a thickness of 75 μm and a flexural rigidity of 352.5 (GPa · μm), the value of the parameter α, the presence / absence of floating, and the presence / absence of deterioration in workability. The result of verifying the relationship with is shown.

That is, in this embodiment, when the thickness (α value) of the adhesive 13 is changed in 8 steps when the thickness of the protective sheet 12 is 75 μm, that is, the bending rigidity is constant at 352.5 (GPa · μm). We are verifying the presence or absence of floating and the presence or absence of deterioration in workability.

Specifically, in Examples 1 to 8, in the same manner as in Example 1, the viscosity of the adhesive 13 20,35,50,65,80,95,110,125 and ^{(× 10 4 mPa · s)} 8 It was changed in stages.

Along with this, the α value changed to 17.63, 10.07, 7.05, 5.42, 4.41, 3.71, 3.20, 2.82 in Examples 1 to 8. ..

As a result, in the case of Example 1 (α value = 17.63), the viscosity of the adhesive is too small (the α value is too large) with respect to the flexural rigidity of the protective sheet 12, so that the protective sheet 12 floats. There was a problem that it occurred. On the other hand, regarding the workability when applying the adhesive 13, no decrease in workability was observed.

Further, in the case of Example 2 (α value = 10.07), the protective sheet 12 did not float, and the workability when applying the adhesive 13 was not deteriorated.

Further, in the case of Example 3 (α value = 7.05), the protective sheet 12 did not float, and the workability when applying the adhesive 13 was not deteriorated.

Further, in the case of Example 4 (α value = 5.42), the protective sheet 12 did not float, and the workability when applying the adhesive 13 was not deteriorated.

Further, in the case of Example 5 (α value = 4.41), the protective sheet 12 did not float, and the workability when applying the adhesive 13 was not deteriorated.

Further, in the case of Example 6 (α value = 3.71), the protective sheet 12 did not float, and the workability when applying the adhesive 13 was not deteriorated.

Further, in the case of Example 7 (α value = 3.20), the protective sheet 12 did not float, and the workability when applying the adhesive 13 was not deteriorated.

Further, in the case of Example 8 (α value = 2.82), the protective sheet 12 did not float. On the other hand, regarding the workability when applying the adhesive 13, the workability was deteriorated because the viscosity of the adhesive 13 was too high (the α value was too small).

As described above, as a result of Examples 1 to 8 included in Example 4, if the range is 3.20 ≦ α ≦ 10.07, the protective sheet 12 does not float and the adhesive 13 is applied. It was found that there was no decrease in workability when doing this.

<Summary of Examples>
As a result of the above verifications in Examples 1 to 4, it was found that the workability of the adhesive 13 deteriorates in the low viscosity region due to the deterioration of the springback, stringiness and sharpness of the protective sheet.

On the other hand, in the high viscosity region of the adhesive 13, defoaming of air entering between the protective sheet 12 and the adhesive 13 becomes difficult due to the relationship with the flexural rigidity of the protective sheet 12, and the adhesive 13 has difficulty in defoaming. There was a problem that the workability of the coating work was lowered.

The value of the parameter α indicating the relationship between the rigidity of the protective sheet 12 and the viscosity of the adhesive 13 enables defoaming work to remove the air trapped between the protective sheet 12 and the concrete structure 11, and also It was found that it is preferable to set the protective sheet 12 in the range of 2.8 to 17.0 where the floating does not occur.

Then, it was found that the range of the value of the parameter α in which the protective sheet 12 does not float is 3.7 to 13.5 while ensuring better adhesiveness and workability.

Further, the range of viscosity of the adhesive 13 capable of suppressing the occurrence of floating of the protective sheet 12 and ensuring adhesiveness and workability depends on the bending rigidity (thickness) of the protective sheet 12, but is 25 to 125 (× 10). It was in the range of ^{4 mPa · s).}

Then, in order to obtain better operability have been found preferable to use an adhesive 13 which has a viscosity in the range of ^{30~80 (× 10 4 mPa · s} ).

Further, regarding the flexural rigidity of the protective sheet 12, if the balance with the viscosity of the adhesive 13 is adjusted, good adhesiveness and work can be achieved for all the flexural rigidity 352 to 884 (GPa · μm) verified in the above examples. In addition to being able to obtain the property, the effect of suppressing the floating of the protective sheet 12 was obtained.

Further, with respect to the thickness of the protective sheet 12, if the balance with the viscosity of the adhesive 13 is adjusted, good adhesiveness and workability can be obtained for all the thicknesses of 75 to 188 (μm) verified in the above examples. At the same time, the effect of suppressing the floating of the protective sheet 12 was obtained.

[Other Embodiments]
Although one embodiment of the present invention has been described above, the present invention is not limited to the above embodiment, and various modifications can be made without departing from the gist of the invention.

(A)
In the above embodiment, an example has been described in which the adhesive 13 is applied to the back surface side of the protective sheet 12 in the step of applying the adhesive 13 and is attached to the surface 11a of the concrete structure 11 in the attaching step. However, the present invention is not limited to this.
For example, in the adhesive application step, the adhesive may be applied to the surface side of the concrete structure.
Even in this case, the same effect as that described in the above embodiment can be obtained.

(B)
In the above embodiment, an example in which a non-breathable sheet is used as the protective sheet 12 to be attached to the surface 11a of the concrete structure 11 has been described. However, the present invention is not limited to this.
For example, the non-moisture permeable 6 sheet that does not completely allow moisture to pass through is not limited, and a sheet that does not allow moisture to pass through may be used.

(C)
In the above embodiment, an example in which a polyester resin sheet such as PET is used as the protective sheet 12 to be attached to the surface 11a of the concrete structure 11 has been described. However, the present invention is not limited to this.
Further, as the protective sheet, a sheet having a multi-layer structure in which one layer or a plurality of thin films are formed on the surface may be used.

(D)
In the above embodiment, an example in which a modified silicone-epoxy adhesive is used as the adhesive 13 used for attaching the protective sheet 12 to the surface 11a of the concrete structure 11 has been described. However, the present invention is not limited to this.
The adhesive used may be a one-component resin composition or a two-component mixture of a two-component mixed resin composition.

Since the concrete surface protection / peeling prevention method of the present invention has the effect of effectively preventing the occurrence of floating of the sheet while ensuring the adhesive strength and workability, the concrete is a sheet-like member. It is widely applicable to the method of pasting.

10 Surface protection / peeling prevention structure (concrete surface protection / peeling prevention structure)
11 Concrete structure 11a Surface 12 Protective sheet 13 Adhesive W1 Water vapor

Claims (14)

It is a concrete surface protection / peeling prevention method that protects the surface of a concrete structure by attaching a protective sheet.
The step of applying an adhesive to the surface of the protective sheet or the concrete structure, and
The step of attaching the protective sheet to the surface of the concrete structure via the adhesive, and
With
The parameters that are the flexural rigidity of the protective sheet obtained by dividing the viscosity of the adhesive α is, to satisfy the following relation (1), the bending rigidity of the protective sheet, the protective sheet conforming to ASTM D882 Standard Is the product of the elastic modulus (GPa) of the above and the thickness (μm) of the protective sheet .
Concrete surface protection / peeling prevention method.
2.8 ≤ α ≤ 17.0 (1) The viscosity of the adhesive is 250,000 to 1.25 million (mPa · s).
The concrete surface protection / peeling prevention method according to claim 1. The viscosity of the adhesive is 300,000 to 800,000 (mPa · s).
The concrete surface protection / peeling prevention method according to claim 2. The flexural rigidity of the protective sheet is 352 to 884 (GPa · μm).
The concrete surface protection / peeling prevention method according to any one of claims 1 to 3. The thickness of the protective sheet is 75 to 188 (μm).
The concrete surface protection / peeling prevention method according to claim 4. The protective sheet is a non-breathable sheet.
The concrete surface protection / peeling prevention method according to any one of claims 1 to 5. The adhesive is a modified silicone-epoxy resin.
The concrete surface protection / peeling prevention method according to any one of claims 1 to 6. A concrete surface protection / peeling prevention structure that is protected by attaching a protective sheet to the surface of the concrete structure.
Concrete structure and
An adhesive that adheres the concrete structure and the protective sheet,
A protective sheet attached to the surface of the concrete structure via the adhesive, and
With
The parameters that are the flexural rigidity of the protective sheet obtained by dividing the viscosity of the adhesive α is, to satisfy the following relation (1), the bending rigidity of the protective sheet, the protective sheet conforming to ASTM D882 Standard Is the product of the elastic modulus (GPa) of the above and the thickness (μm) of the protective sheet .
Concrete surface protection / peeling prevention structure.
2.8 ≤ α ≤ 17.0 (1) The viscosity of the adhesive is 250,000 to 1.25 million (mPa · s).
The concrete surface protection / peeling prevention structure according to claim 8. The viscosity of the adhesive is 300,000 to 800,000 (mPa · s).
The concrete surface protection / peeling prevention structure according to claim 9. The flexural rigidity of the protective sheet is 352 to 884 (GPa · μm).
The concrete surface protection / peeling prevention structure according to any one of claims 8 to 10. The thickness of the protective sheet is 75 to 188 (μm).
The concrete surface protection / peeling prevention structure according to claim 11. The protective sheet is a non-breathable sheet.
The concrete surface protection / peeling prevention structure according to any one of claims 8 to 12. The adhesive is a modified silicone-epoxy resin.
The concrete surface protection / peeling prevention structure according to any one of claims 8 to 13.

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