JP2019035234A - Surface protection construction method for cement hardened body structure and surface protection structure of cement hardened body structure - Google Patents

Abstract

To provide a surface protection construction method capable of favorably constructing a cement hardened body structure without causing float on a corner portion of the cement hardened body structure, and a surface protection structure in which the cement hardened body structure is favorably constructed without float on the corner portion of the cement hardened body structure.SOLUTION: The surface protection construction method for a cement hardened body structure includes a pre-coating process of pre-coating a filling resin composition 300' containing the modified silicone resin on a corner surface 251 of a cement hardened body structure 200, and an adhering process of adhering a protection sheet 300 to the pre-coated filling resin composition 300' and entire surface of the cement hardened body structure 200, and the protection sheet 300 includes a resin layer and a carbon film.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a surface protection method for a hardened cementitious structure and a surface protective structure for a hardened cementitious structure.

  Concrete is gradually neutralized by carbon dioxide in the air. When neutralization proceeds to the inside of the concrete, the reinforcing bars corrode and the strength of the concrete structure is greatly reduced. For this reason, Japanese Patent Application Laid-Open No. 2003-342084 (Patent Document 1) proposes a technique for preventing the neutralization of concrete by applying a coating material made of an epoxy resin composition or the like to the surface of a concrete structure. . As described above, in the method of applying the coating material to the surface of the concrete structure, it is necessary to sequentially form many layers such as primer, putty, undercoat, intermediate coat, top coat, etc. Become. As a means for solving this problem, Japanese Unexamined Patent Application Publication No. 2014-9508 (Patent Document 2) includes a concrete structure and a protective sheet that covers the surface of the concrete structure, and the protective sheet is made of a resin. And a protective structure for a concrete structure and a protective method for the concrete structure, including a carbon film, preferably a diamond-like carbon film.

JP 2003-342084 A JP 2014-9508 A

  The protective sheet having a carbon film has a problem of workability due to poor followability of the corners such as the corners of entry and exit of a concrete building due to the high rigidity and high elasticity of the carbon film. In addition, due to such poor followability to the corner surface, the protective sheet floats at the corner. For example, as shown in FIG. 5, the protection sheet 300 is lifted at the protruding corner of the concrete building 200, resulting in poor construction. As shown in FIG. 5, when the corner portion is a protruding corner, the protective sheet is lifted, resulting in poor appearance.

  Therefore, the object of the present invention is to provide a surface protection method that can be applied satisfactorily without causing floating at the corners of the hardened cement structure, and to be applied without any lift at the corners of the hardened cement structure. It is to provide a surface protection structure.

The present invention includes the following inventions.
(1)
The method for protecting the surface of a hardened cementitious structure of the present invention includes a preliminary application step and a pasting step. In the preliminary step, a filling resin composition containing a modified silicone resin is preliminarily applied to the corner surface of the hardened cementitious structure. In the attaching step, a protective sheet is attached to the entire surfaces of the pre-applied filling resin composition and the hardened cementitious structure. Furthermore, the protective sheet includes a resin layer and a carbon film.

  In this way, even if the protective sheet has a carbon film, it is filled with the adhesive resin composition in the part where the float has conventionally occurred by pre-applying to the corner surface of the hardened cementitious structure. Therefore, the followability of the protective sheet to the corners is improved through the pre-applied filling resin composition. For this reason, it becomes possible to make the protective sheet adhere well to the entire surface of the hardened cementitious structure including the corners.

(2)
In the method for protecting a surface of a cement cured body structure according to (1) above, the filling resin composition may have a viscosity of 150 Pa · s to 1000 Pa · s and a thixo index of 4.5 to 8.5. .

  Thus, workability | operativity becomes favorable by making a viscosity and a thixo index into a predetermined range.

(3)
In the method for protecting a surface of a cement cured body structure according to the above (1) or (2), the product of the elastic modulus (GPa) and the thickness (μm) of the protective sheet may be 200 or more and 900 or less.

  As described above, the present invention makes it possible to better fix the protective sheet to the entire surface of the hardened cementitious structure including the corners by setting the product of the elastic modulus and thickness of the protective sheet within a predetermined range. At the same time, surfaces other than the corners can be coated with good appearance and good workability.

(4)
The method for protecting a surface of a hardened cementitious structure according to any one of the above (1) to (3) may further include a chamfering step of chamfering a corner of the hardened cementitious structure before the preliminary application step.

  As a result, the surface to be preliminarily applied can be secured satisfactorily, and the protective sheet can be better fixed to the entire surface of the hardened cementitious structure including the corners.

(5)
Surface protection structure of hardened cementitious structure according to the present invention includes a hardened cementitious structure, a hardened product of a filling resin composition including a modified silicone resin provided on a corner surface of the hardened cementitious structure, and cement And a protective sheet provided on the entire surface of the cured body structure and the cement cured body structure. The protective sheet includes a resin layer and a carbon film.

  Thus, even if the protective sheet has a carbon film, the hardened material of the specific filling resin composition is provided on the corner surface of the cured cementitious structure, so that the conventional floating has occurred. Therefore, the followability of the protective sheet to the corners is improved through the cured product of the filling resin composition. For this reason, the protective sheet adheres well to the entire surface of the hardened cementitious structure including the corners.

(6)
In the surface protection structure of the cement cured body structure according to the above (5), the tensile strength of the cured product of the filling resin composition may be 0.7 N / mm ² or more.

  Thus, a hardened | cured material provided in the corner | angular part of a structure has predetermined | prescribed tensile strength, and a protective state is maintained favorable.

  According to the present invention, the surface protection method that can be applied satisfactorily without causing the corners of the hardened cementitious structure to float, and the corners of the hardened cementitious structure can be satisfactorily applied without lifting. A surface protection structure is provided.

It is typical sectional drawing explaining the surface protection construction method of the cement hardening body structure of 1st Embodiment. It is a continuation of FIG. It is typical sectional drawing explaining the surface protection construction method of the cement hardening body structure of 2nd Embodiment. It is a continuation of FIG. It is typical sectional drawing of the concrete building protection structure by the surface protection method of the conventional method.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following description, the same elements are denoted by the same reference numerals, and their names and functions are also the same. Therefore, detailed description thereof will not be repeated basically.

[1. First Embodiment]
FIG. 1 and FIG. 2 are schematic cross-sectional views illustrating a surface protection structure for a hardened cement structure according to the first embodiment and a method for protecting the surface of the hardened cement structure for obtaining the same. In the present embodiment, the surface of the concrete building 200 is protected by the protective sheet 300.

[1-1. Concrete structure (hardened cement structure)]
The concrete structure 200 includes concrete and a core material such as a reinforcing bar. Concrete is a mixture of cement, water, gravel, sand, etc., and hardened by the cement hydration reaction. The concrete structure 200 may be a newly established person or may be in service. Examples of the concrete structure 200 include concrete viaducts (beams, columns, etc.), concrete girder bridges, electrical poles, buildings, houses, and the like.

  In the present embodiment, the portion including the projecting corner 250 of the concrete structure 200 is protected. The protruding corner 250 has a chamfered surface 251. The width w of the chamfered surface 251 may be appropriately determined by a person skilled in the art according to the minimum bending radius of the protective sheet 300 so as not to be lifted in a pasting process described later, and may be, for example, 5 mm or more and 50 mm or less. Thereby, the followability of the protective sheet 300 to the protruding corner 250 becomes better.

  In the case where the projecting corner 250 of the concrete building 200 does not have the chamfered surface 251 as described above (in the present embodiment, the projecting corner 250 is a right angle), or because the chamfered surface 251 has a slight width, it will be described later. In the case where floating occurs in the pasting process, a chamfering process for chamfering the protruding corner 250 by, for example, C-surface machining can be performed.

  A base adjustment coating film may be provided in advance on the surface of the concrete building 200. Examples of the base adjustment coating include ethylene vinyl acetate resin, acrylic resin, and acrylic cation emulsion.

[1-2. Adhesive application process]
In the present embodiment, the adhesive resin composition 400 ′ is applied to the entire surface of the concrete building 200 to form an application layer of the adhesive resin composition 400 ′. The adhesive resin composition 400 ′ is not particularly limited and can be appropriately determined by those skilled in the art. For example, an epoxy adhesive, a urethane adhesive, a silicone adhesive, a rubber adhesive, and the like can be given. Among these, the elastic adhesive can be selected in that the difference between the linear expansion coefficient of the concrete building 200 to be protected and the linear expansion coefficient of the resin layer 310 of the protective sheet 300 is buffered.

  The adhesive resin composition 400 ′ may be a so-called one-component resin composition or a two-component mixture of a so-called two-component mixed resin composition. In the case of a one-component resin composition, the work is easy and the work efficiency is good, and further, the curing of the adhesive resin composition to be cured is difficult to cause poor curing, Therefore, good adhesiveness can be easily obtained. The two-component mixed resin composition is preferable in that the adhesiveness is good regardless of the degree of unevenness and / or cracking on the surface of the concrete structure 200, and the weather resistance is also good.

[1-3. Pre-application process]
In the preliminary application step, the filling resin composition 500 ′ is applied to the chamfered surface 251 of the protruding corner 250. In the illustrated embodiment, the filling resin composition 500 ′ is applied through the layer of the adhesive resin composition 400 ′, but the present invention is not limited to this embodiment. For example, the layer of the adhesive resin composition 400 ′ may be missing at the chamfered surface 251, and the filling resin composition 500 ′ may be directly applied to the chamfered surface 251.

[1-3-1. Composition of Resin Composition for Filling]
Filling resin composition 500 ′ is an adhesive resin composition containing a modified silicone resin. Specifically, the filling resin composition 500 ′ includes a modified silicone resin and a curing agent (specifically, a silanol condensation catalyst or the like), and may include other resins and curing agents thereof. As an example, a resin composition containing a modified silicone, an epoxy resin, and a curing agent thereof can be given.

  The filling resin composition 500 ′ may also be a so-called one-component resin composition or a two-component mixture of a so-called two-component mixed resin composition. In the case of a one-component resin composition, the work is easy and the work efficiency is good, and further, the curing resin is less likely to be hardened in terms of the uniformity of the filling resin composition to be cured. Therefore, good adhesiveness can be easily obtained. The two-component mixed resin composition is preferable in that it can be easily applied to a narrow surface such as a chamfered surface 251 and has good weather resistance.

  The modified silicone resin is not particularly limited, but is preferably a moisture-curing modified silicone resin that undergoes a condensation reaction with moisture in the air or moisture mixed in the resin composition in the presence of a curing catalyst. In this case, it has a hydrolyzable silicon group. The modified silicone resin having a hydrolyzable silicon group has a polymer selected from the group consisting of a polyether polymer, a polyolefin polymer and an acrylic polymer as a main chain (a portion excluding the hydrolyzable silicon group). Therefore, the main chain may be a polymer of a monomer selected from the group consisting of an alkylene oxide component, an olefin component, and an acrylic component, and this polymer may be a homopolymer or a copolymer. In the case of a copolymer, the copolymer component may be selected from the group consisting of an alkylene oxide component, an olefin component, an acrylic component, and other vinyl components.

Examples of the alkylene oxide component include ethylene oxide, propylene oxide, butylene oxide and the like. The main chain is preferably polypropylene oxide mainly composed of propylene oxide units from the viewpoints of elongation after curing and viscous handling.
An isobutylene is mentioned as an olefin component.

  Examples of the acrylic component include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, n-butyl (meth) acrylate, tert-butyl (meth) acrylate, cyclohexyl (meth) acrylate, 2-ethylhexyl (meth) ) Acrylate, n-octyl (meth) acrylate, isooctyl (meth) acrylate, isononyl (meth) acrylate, isomyristyl (meth) acrylate, stearyl (meth) acrylate, isobornyl (meth) acrylate, benzyl (meth) acrylate, 2- Butoxyethyl (meth) acrylate, 2-phenoxyethyl (meth) acrylate, glycidyl (meth) acrylate, tetrahydrofurfuryl (meth) acrylate, hexanediol di (meth) ) Acrylate, ethylene glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, propylene glycol di (meth) acrylate, polypropylene glycol di (meth) acrylate, neopentyl glycol di (meth) acrylate, trimethylolpropane tri (meth) ) Acrylate, pentaerythritol di (meth) acrylate, pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol hexa (meth) acrylate, epoxy acrylate, polyester acrylate, urethane acrylate, 2-hydroxyethyl ( (Meth) acrylate, 3-hydroxypropyl (meth) acrylate, 2-hydroxypropyl (meth) Acrylate, 4-hydroxybutyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, 5-hydroxypentyl (meth) acrylate, 6-hydroxyhexyl (meth) acrylate, 3-hydroxy-3-methylbutyl (meth) acrylate, 2-hydroxy-3-phenoxypropyl (meth) acrylate, pentaerythritol tri (meth) acrylate, 2-[(meth) acryloyloxy] ethyl 2-hydroxyethylphthalic acid, 2-[(meth) acryloyloxy] ethyl 2- And hydroxypropylphthalic acid. In the case where the acrylic polymer is a copolymer of other vinyl monomer components, hydrolyzable silicon groups can be introduced by copolymerizing vinyl monomer components having hydrolyzable silicon groups.

  It is preferable that the main chain contains an acrylic unit from the viewpoint of good weather resistance. Furthermore, from the viewpoint of weather resistance, the content of the acrylic unit in the main chain is preferably 5% by weight or more and 20% by weight or less.

The hydrolyzable silicon group is not particularly limited, and examples thereof include a halogenated silyl group, an alkenyloxysilyl group, an acyloxysilyl group, an aminosilyl group, an aminooxysilyl group, an oximesilyl group, an amidosilyl group, and an alkoxysilyl group. Here, the number of hydrolyzable groups bonded to silicon atoms in the hydrolyzable silicon group is preferably 1 or more and 3 or less. Further, the hydrolyzable group bonded to one silicon atom may be one kind or plural kinds. Furthermore, the hydrolyzable group and the non-hydrolyzable group may be bonded to one silicon atom. The hydrolyzable silicon group is preferably an alkoxysilyl group such as a monoalkoxysilyl group, a dialkoxysilyl group, or a trialkoxysilyl group in terms of excellent stability and easy handling.
The modified silicone resins may be used alone or in combination of two or more.

  The number average molecular weight of the modified silicone resin having a hydrolyzable silicon group is, for example, 1,000 or more and 500,000 or less, 1,000 or more and 100,000 or less, 10,000 or more and 30,000 or less, and 4,000 or more and 500. 4,000 or less, or 4,000 or more and 30,000 or less. It is preferable that it is more than the said lower limit from the point that the hardening time of the resin composition for filling is short, or the adhesive strength after hardening is favorable. It is preferable that the viscosity is not more than the upper limit because the viscosity of the filling resin composition is appropriate and the handleability is good.

  The silanol condensation catalyst is used for curing the modified silicone resin composition in a short time. Examples of the silanol condensation catalyst include poly (dialkylstannoxane) disilicate compounds, tin catalysts such as monoalkyl tin esters and dialkyl tin esters, and organic titanates.

Examples of the monoalkyltin ester include butyltin tris (2-ethylhexanoate). Examples of the dialkyltin ester include dibutyltin acetate, dibutyltin dilaurate, dibutyltin dioctoate, dibutyltin dioleate, and dibutyltin. Examples include dimethoxide, dibutyltin diphenoxide, dibutyltin diacetylacetonate, dibutyltin acetoacetate, and stannous octoate.
Examples of the organic titanates include titanium alkoxides such as tetrabutyl titanate, tetraisopropyl titanate, tetramethyl titanate, tetra (2-ethylhexyl titanate) triethanolamine titanate, titanium tetraacetylacetonate, titanium ethylacetoacetate, octyleneglycol. And titanium chelates such as rate.
A silanol condensation catalyst may be used independently and may be used together 2 or more types.

  The content of the silanol condensation catalyst in the adhesive resin composition is 0.1 to 10 parts by weight, preferably 1 to 5 parts by weight, with respect to 100 parts by weight of the modified silicone resin. It is preferable from the point of shortening of hardening time that it is more than the said lower limit. It is preferable that it is below the upper limit in terms of ensuring physical properties such as adhesive strength.

  When the filling resin composition 500 ′ includes an epoxy resin, the epoxy resin is not particularly limited as long as it is a resin having an epoxy group. Specific examples include those in which a glycidyl group is bonded to a compound selected from the group consisting of unsaturated aliphatic compounds, alicyclic compounds, aromatic compounds, and heterocyclic compounds. From the viewpoint of the neutralization suppressing effect, it is preferable to include an aromatic compound.

Examples of the epoxy resin include bisphenol type epoxy resins such as bisphenol A type, bisphenol F type, bisphenol S type and hydrogenated products thereof; glycidyl ether type epoxy resins such as polypropylene glycol diglycidyl ether type epoxy resins; Ester type epoxy resins such as glycidyl ester type epoxy resins; Novolak type epoxy resins such as phenol novolak type and cresol novolak type, bisphenol A novolak type epoxy resins and hydrogenated products thereof; Trisphenol type such as triphenolmethane type epoxy resin Multifunctional epoxy resin; triglycidyl isocyanurate type, tetraglycidyl diaminodiphenylmethane type, tetraglycidyl metaxylenediamine type, hydan Nitrogen-containing polyfunctional epoxy resins such as in-type; condensed ring-type epoxy resins such as naphthalene type; biphenyl-type epoxy resins; dicyclopentadiene-type epoxy resins; ether ester-type epoxy resins; 3,4-epoxycyclohexylmethyl-3 An epoxy resin having an alicyclic structure such as', 4'-epoxycyclohexanecarboxylate; a urethane type epoxy resin; a rubber-modified epoxy resin having a rubber skeleton such as polybutadiene and acrylonitrile butadiene rubber (NBR) can be used.
An epoxy resin may be used individually by 1 type, and may use 2 or more types together.

  The content of the epoxy resin in the adhesive resin composition is, for example, 1 part by weight or more and 100 parts by weight or less, preferably 2 parts by weight or more and 80 parts by weight or less with respect to 100 parts by weight of the modified silicone resin. By being more than the said lower limit, favorable toughness can be obtained in the adhesive layer 400 after hardening, and favorable elasticity can be obtained in the adhesive layer 400 after hardening by being below the said upper limit. Therefore, the crack of the carbon film 350 of the protective sheet 300 can be preferably suppressed.

Examples of the epoxy curing agent include amine compounds. Examples of amine compounds include aliphatic tertiary amines such as N, N-dimethylpropylamine, N, N, N ′, N′-tetramethylhexamethylenediamine, N-methylpiperidine, and N, N′-dimethylpiperazine. Alicyclic tertiary amines, benzyldimethylamine, dimethylaminomethylphenol, aromatic tertiary amines such as 2,4,6-tris (dimethylaminomethyl) phenol, ethylenediamine, diethylenetriamine, triethylenetetramine, pentaethylene Aliphatic diamines such as hexamine, trimethylene diamine, hexamethylene diamine, tetramethylene diamine, alicyclic diamines such as 1,3-bis (aminomethyl) cyclohexane, isophorone diamine, norboldene diamine, diaminodiphenylmethane, Metaphenylene Aromatic diamines such as diamines may be mentioned.
In addition to the above, examples of the epoxy curing agent include polyamide resins; imidazoles such as 2-ethyl-4-methylimidazole; and compounds such as carboxylic acid anhydrides such as phthalic anhydride.

Further, the epoxy curing agent may be a latent curing agent such as ketimine that is blocked with an active amine and activated under predetermined conditions such as moisture. For example, ketimine exists stably in the absence of moisture, but generally becomes a primary amine due to the presence of moisture and reacts with an epoxy resin. Specifically, 2,5,8-triaza-1,8-nonadiene, 2,10-dimethyl-3,6,9-triaza-2,9-undecadiene, 2,10-diphenyl-3,6,9 -Triaza-2,9-undecadiene, 3,11-dimethyl-4,7,10-triaza-3,10-tridecadiene, 3,11-diethyl-4,7,10-triaza-3,10-tridecadiene, 2 , 4,12,14-tetramethyl-5,8,11-triaza-4,11-pentadecadiene, 2,4,20,22-tetramethyl-5,12,19-triaza-4,19-tri Examples include eicosadiene and 2,4,15,17-tetramethyl-5,8,11,14-tetraaza-4,14-octadecadien.
Epoxy curing agents may be used alone or in combination of two or more.

  The content of the epoxy curing agent in the filling resin composition is, for example, 20 parts by weight or more and 60 parts by weight or less, and preferably 30 parts by weight or more and 50 parts by weight or less with respect to 100 parts by weight of the epoxy resin. Alternatively, when a latent curing agent is used as the epoxy curing agent, the total number of epoxy groups in the epoxy resin relative to the total number of active amino groups generated by activation (total number of moles of epoxy groups / total number of active amino groups). The number of moles) is, for example, 0.8 or more and 1.2 or less, preferably 0.9 or more and 1.1 or less. It is preferable from the viewpoint of the elastic modulus of the cured film that it is not less than the above lower limit value, and it is preferable from the viewpoint of storage stability that it is not more than the above upper limit value.

  The filling resin composition 500 ′ may further contain other additives as necessary. Examples of other additives include dehydrating agents, antioxidants, fillers, plasticizers, sagging inhibitors, ultraviolet absorbers, pigments, solvents, and fragrances.

  As the above-mentioned filling resin composition 500 ′, a non-heated or heated product to which water is further added may be used. When heated, the temperature can be, for example, 40 ° C. or more and 80 ° C. or less. It is preferable that it is more than the said lower limit from the point which acquires sufficient adhesive force in a short time. It is preferable that it is not more than the above upper limit value in order to prevent the protective sheet 300 from being damaged.

[1-3-2. Physical properties of resin composition for filling]
The viscosity of the filling resin composition 500 ′ may be, for example, 150 Pa · s or more and 1000 Pa · s or less, preferably 300 Pa · s or more and 700 Pa · s or less. It is preferable that the viscosity is equal to or higher than the lower limit value from the viewpoint of difficulty of dripping, and that the viscosity is equal to or lower than the upper limit value is preferable from the viewpoint of ease of application. Further, the viscosity being equal to or higher than the lower limit value can appropriately ensure the thickness of the coating film of the filling resin composition 500 ′, and being equal to or lower than the upper limit value is equivalent to the filling resin composition 500 ′. Is preferable in that the peeling of the protective sheet 300 can be more effectively suppressed. In this specification, the viscosity is determined according to JIS Z 8803 using a B-type viscometer as a single cylindrical viscometer. It is a value measured at 7 rotors and 23 ° C. By making the viscosity within the above range, workability is improved.

  Further, the thixo index (23 ° C.) of the filling resin composition 500 ′ may be 3.5 or more and 9.0 or less, preferably 4.5 or more and 8.0 or less. For the thixo index, a BS viscometer was used. The viscosity measured under the condition of 1 rpm of 7 rotors was measured using the BS viscometer. It is obtained as a value divided by the viscosity measured under the condition of 10 rpm of 7 rotors. By making the thixo index within the above range, workability is improved.

[1-4. Pasting process]
After providing the layer of the filling resin composition 500 ′, the protective sheet 300 is attached to the entire surface of the concrete building 200. At this time, the protective sheet 300 integrally covers the chamfered surface 251 of the protruding corner 250 and both surfaces thereof. At this time, the protective sheet 300 is pasted so that the bent surface is smooth. Since the layer of the filling resin composition 500 ′ is provided, the portion where the float has conventionally occurred is filled with the filling resin composition 500 ′ and the filling resin composition 500 ′ is filled with this step. The surface can be formed in a gentle and smooth shape, and therefore the followability to the protruding corner 250 of the protective sheet 300 is good.

[1-4-1. Protective sheet]
The protective sheet 300 includes a resin layer 310 and a carbon film 350. In this embodiment, although it affixes so that the resin layer 310 side of the protection sheet 300 may oppose the concrete building 200, it is not limited to this aspect. In the present invention, the protective film may be attached so that the carbon film 350 side of the protective sheet faces the concrete building 200.

  The product of the elastic modulus (GPa) and the thickness (μm) of the protective sheet 300 may be, for example, 200 or more and 900 or less, preferably 300 or more and 900 or less. It is preferable that the product is equal to or more than the lower limit in that wrinkles can be easily prevented from being formed on the covering portion of the surface of the concrete building 200 (particularly, the entire wide area other than the chamfered surface 251). It is preferable that the value is equal to or less than the value in that the floating of the protective sheet 300 can be easily prevented from occurring in the covering portion of the protruding corner 250.

  Specifically, the elastic modulus of the protective sheet 300 may be 0.7 GPa to 7 GPa, preferably 1 GPa to 7 GPa, more preferably 2 GPa to 6 GPa, as measured according to ASTM D882. It is preferable that the elastic modulus is equal to or higher than the lower limit value in terms of good stiffness of the protective sheet 300 and easy to suppress wrinkles, and being equal to or lower than the upper limit value is easy to suppress the occurrence of floating. preferable. Further, the thickness of the protective sheet 300 may be, for example, 50 μm or more and 500 μm or less, preferably 75 μm or more and 200 μm or less. That the thickness is equal to or greater than the lower limit is preferable in terms of good stiffness of the protective sheet 300 and easily suppresses the occurrence of wrinkles, and being equal to or less than the upper limit is less likely to suppress the occurrence of float. preferable.

  The protective sheet 300 may have an ultraviolet transmittance of, for example, 80% or less, preferably 70% or less, and more preferably 60% or less. The ultraviolet transmittance can be measured using a spectrophotometer (for example, UV-2600 manufactured by Shimadzu Corporation). When the protective sheet 300 has such an ultraviolet barrier property, the protective sheet 300 itself is deteriorated, the cured adhesive resin composition 400 ′ (adhesive layer 400), and the filling resin composition 500 ′ (adhesive layer 500). ) And / or deterioration of the concrete 210 can be preferably suppressed.

[1-4-2. Resin layer]
The resin layer 310 may be made of resin, such as polyester resin (polyethylene terephthalate, polyethylene naphthalate, etc.), fluororesin (tetrafluoroethylene / ethylene copolymer, etc.), polyamide resin (nylon, etc.), polycarbonate resin, acrylic resin, etc. Examples thereof include resins, phenol resins, melamine resins, epoxy resins, urea resins, vinyl chloride resins, polyolefin resins (polyethylene, polypropylene, etc.).
Among these, a polyester resin is preferable from the viewpoint of obtaining a preferable damage suppressing effect of the carbon film 350.

The linear expansion coefficient of the resin constituting the resin layer 310 in accordance with JIS K7197 is 10 × 10 ⁻⁵ / K or less, preferably 5 × 10 ⁻⁵ / K or less, more preferably 3 × 10 ⁻⁵ / K or less. More preferably, it may be 2 × 10 ⁻⁵ / K or less, and still more preferably 1.5 × 10 ⁻⁵ / K or less. It is preferable that the value is not more than the upper limit in terms of preventing the resin layer 310 itself from cracking and preventing the carbon film 350 from following the crack. Although the lower limit within the range of the linear expansion coefficient is not particularly limited, it is preferably 0 / K.

[1-4-3. Carbon film]
The protective layer of the protective sheet 300 is a carbon film 350 made of carbon. The carbon film 350 suppresses the neutralization of the concrete 210. Although various carbon films are applied as the carbon film 350, a diamond-like carbon (DLC) film is preferable from the viewpoint of neutralization suppression effect. Further, the DLC film can also suppress transmission of oxygen, water vapor, and ultraviolet rays. The DLC film is an amorphous film including both a diamond structure (sp3 bond) and a graphite structure (sp2 bond). The carbon film is allowed to contain hydrogen, oxygen, and nitrogen. The mixing ratio of the diamond structure and the graphite structure and the contents of hydrogen, oxygen, and nitrogen are not particularly limited. More specifically, ta-C (tetrahedral amorphous carbon), aC (amorphous carbon), ta-C: H (hydrogenated tetrahedral amorphous carbon), and aC: H (hydrogenated amorphous). Carbon).

  The thickness of the carbon film 350 may be, for example, 0.005% or more and 0.5% or less with respect to the thickness of the resin layer 310. Alternatively, it may be 10 nm to 1000 nm, preferably 10 nm to 500 nm, and more preferably 10 nm to 200 nm. It is preferable that the thickness of the carbon film 350 is equal to or greater than the above lower limit value because it is easy to obtain a neutralization suppressing effect, and that the thickness is equal to or less than the upper limit value is preferable because it is difficult to cause damage to the carbon film 350. .

  The protective sheet 300 can be manufactured by using the resin layer 310 as a base material and forming a carbon film by various vapor deposition methods. For example, specific examples of the vapor deposition method include a plasma CVD method and a sputtering method. Furthermore, examples of the plasma CVD method include an atmospheric pressure plasma CVD method and a plasma CVD method under high vacuum.

[1-5. Surface Protective Structure of Hardened Cement Structure] After the pasting step is completed, curing is performed to cure the coating layer of the adhesive resin composition 400 ′ and the layer of the filling resin composition 500 ′. As a result, the protective sheet 300 is made of the concrete structure 200 including the protruding corner 250 by the adhesive layer 400 (cured product of the adhesive resin composition 400 ′) and the adhesive layer 500 (cured product of the filling resin composition 500 ′). The surface protection structure 100 is configured by firmly bonding to the entire surface. In the protruding corner 250, the surface of the adhesive layer 500 is gently and smoothly formed, so that the protective sheet 300 is adhered with good followability, so that the appearance is improved.

  The protruding corner 250 of the surface protection structure 100 is easily subjected to an external physical load in an actual use environment. Since the adhesive layer 500 is a cured product of the filling resin composition 500 ′ containing a modified silicone resin, the load applied to the protruding corner 250 can be absorbed by its elasticity. Therefore, the surface protection structure 100 is well maintained in the actual use environment.

The tensile strength based on JIS K6251 of the cured resin composition 500 ′ constituting the adhesive layer 500 may be, for example, 1.0 N / mm ² or more, preferably 1.2 N / mm ² or more. Thereby, it is excellent in adhesive strength with the adjacent surface (the surface of the protective sheet 300, or the surface of the protective sheet 300 and the surface of the concrete building 200), and the protective state is maintained well. The tensile strength of the adhesive layer 500 may be, for example, 10 N / mm ² or less, preferably 5 N / mm ² or less. As a result, an appropriate rigidity is ensured, and the thickness of the adhesive layer 500 is preferably maintained, so that the protection state is well maintained.

  The tensile strength according to JIS K6251 of the cured resin composition 500 ′ constituting the adhesive layer 500 is, for example, 0.5 to 1 time, preferably 0. It may be 6 times or more and 0.8 times or less. It is preferable that the tensile strength of the adhesive layer 500 is equal to or higher than the above lower limit from the viewpoint that the follow-up to the adhesive layer 400 is good and the adhesive state with the adhesive layer 400 is maintained. It is preferable in that a sufficient rigidity is secured and the protection state is maintained well.

  The elongation percentage based on JIS K6251 of the cured resin composition 500 'constituting the adhesive layer 500 may be, for example, 10% or more, preferably 150% or more, more preferably 300% or more. Thereby, it is excellent in adhesive strength with the adjacent surface (the surface of the protective sheet 300, or the surface of the protective sheet 300 and the surface of the concrete building 200), and the protective state is maintained well. The upper limit of the elongation rate of the adhesive layer 500 is not particularly limited, and it is preferably as large as possible.

  The elongation percentage based on JIS K6251 of the cured resin composition 500 ′ constituting the adhesive layer 500 is, for example, 1.5 times to 4 times, preferably 1.6 times the elongation ratio of the adhesive layer 400. It may be 3.7 times or less. It is preferable that the elongation percentage of the adhesive layer 500 is equal to or higher than the above lower limit from the viewpoint that the follow-up to the adhesive layer 400 is good and the adhesion state with the adhesive layer 400 is maintained. Is ensured and the protection state is favorably maintained.

[2. Second Embodiment]
In the second embodiment below, differences from the first embodiment will be mainly described, and the description of the common points will be basically omitted.

FIG. 3 and FIG. 4 are schematic cross-sectional views for explaining the surface protection structure of the hardened cementitious structure according to the second embodiment and the method of protecting the surface of the hardened cementitious structure for obtaining the same.
In this embodiment, the part including the corners 250a of the concrete structure 200 is protected. In this embodiment, the entrance corner 250a has a chamfered surface 251a. As a result, the filling resin composition is applied to the entire entrance corner 250a.

  As shown in FIG. 3, a coating layer of the adhesive resin composition 400 ′ is formed by the adhesive coating step, and a coating layer of the filling resin composition 500 ′ is formed on the chamfered surface 251a of the entrance corner 250a by the preliminary coating step. To do. In the illustrated embodiment, the filling resin composition 500 ′ is applied through the layer of the adhesive resin composition 400 ′, but is not limited to this embodiment. For example, the layer of the adhesive resin composition 400 ′ may be missing at the chamfered surface 251 a, and the filling resin composition 500 ′ may be directly applied to the chamfered surface 251 a.

As shown in FIG. 4, the chamfered surface 251 a of the entrance corner 250 a and both surfaces thereof are integrally covered with the protective sheet 300 by the attaching process. At this time, the protective sheet 300 is pasted so that the bent surface is smooth. Thereafter, the coating layer of the adhesive resin composition 400 ′ and the layer of the filling resin composition 500 ′ are cured and the protective sheet 300 is bonded to the adhesive layer 400 (cured product of the adhesive resin composition 400 ′) and bonded. The surface protection structure 100a adhered by the layer 500 (cured product of the filling resin composition 500 ′) is formed. In the entrance corner 250a, the surface of the adhesive layer 500 is gently and smoothly formed, so that the protective sheet 300 is adhered with good followability. It is glued to.

  In the present embodiment, the aspect in which the entering corner 250a has the chamfered surface 251a is shown, but the present invention is not limited to this aspect. For example, when the entering corner 250a does not have the chamfered surface 251a (in this embodiment, when the entering corner 250a is a right angle), more filling resin composition 500 'may be used.

  EXAMPLES Hereinafter, although an Example is given and this invention is demonstrated, this invention is not limited to these Examples.

[Examples 1 to 8]
A box culvert having a width of about 30 mm on the C surface was prepared as a test body for the hardened cement structure.
As the filling resin composition, an adhesive resin composition containing modified silicone (manufactured by Sekisui Fuller, product number A-430C) was prepared. The viscosity (value measured at 23 ° C. of No. 7 rotor using a B-type viscometer as a single cylindrical viscometer in accordance with JIS Z 8803) of this filling resin composition is 500 Pa · s, Thixo Index (value obtained by dividing the viscosity measured under the condition of 1 rpm of the No. 7 rotor using the BS viscometer by the viscosity measured under the condition of 10 rpm of the No. 7 rotor using the BS viscometer) 7 and the tensile strength of the cured product according to JIS K6251 was 1.0 N / mm ² .
As a protective sheet, a laminated sheet in which a 40 nm DLC film was provided on a resin sheet having a predetermined thickness (see Table 1) was prepared. The elastic modulus according to ASTM D882 of this laminated sheet was 0.8 GPa, 4.7 GPa, or 6 GPa.

  An adhesive resin composition (manufactured by Sekisui Fuller, developed product number A-430T) was applied to the entire surface including the outer corner (outside corner) of the box culvert with a coating thickness of about 1.0 mm. Further, the filling resin composition was applied on the chamfered surface of the corner with a coating thickness of about 1.0 mm to 10 mm. After that, a protective sheet was pasted and cured to obtain a surface protective structure for the box culvert. Alternatively, the filling resin composition was applied with a coating thickness of about 1.0 mm to 10 mm on the chamfered surface of the outer corner of the box culvert. A protective sheet coated with an adhesive resin composition (manufactured by Sekisui Fuller Co., Ltd., developed product number A-430T) with a coating thickness of about 1.0 mm was applied and cured to obtain a surface protective structure of a box culvert.

  Table 1 summarizes the specific layer structure of the protective sheet, the thickness of each layer, the product of the elastic modulus (GPa) and the total thickness (μm), and the construction evaluation (whether or not the corners are lifted).

  As shown in Table 1, in all the examples, the corner portion did not float. Among Examples 1 to 7, in particular, Examples 1 to 5 not only do not cause the corners to float, but compared to Examples 6 to 8, there is no occurrence of wrinkles on the surfaces other than the corners, and the appearance is good. In addition, it was easier to handle the protective sheet and finish without causing wrinkles on the surfaces other than the corners. Furthermore, Examples 1, 2, 3 and 5 were particularly easy to handle compared to Example 4 and to finish without causing wrinkles on the surfaces other than the corners and handling of the protective sheet. It was.

[Comparative Examples 1 to 5]
A surface protective structure of box culvert was obtained in the same manner as in Examples 1 to 5 except that the filling resin composition was not used.
Table 2 summarizes the specific layer structure of the protective sheet, the thickness of each layer, the product of the elastic modulus (GPa) and the total thickness (μm), and the construction evaluation (presence or absence of lifting at the corners).

  As shown in Table 2, in all the comparative examples, the corners were lifted.

Preferred embodiments of the present invention are as described above, but the present invention is not limited to them, and various other embodiments are possible without departing from the spirit of the present invention.

[Correspondence Relationship Between Each Part of Embodiment and Each Component in Claim]
In the present specification, the surface protection structures 100 and 100a correspond to the “surface protection structure of the hardened cement structure” in the claims, the concrete structure 200 corresponds to the “hardened cement structure”, The corners 250a correspond to “corners”, the chamfered surfaces 251 and 251a correspond to “corner surfaces”, the protective sheet 300 corresponds to “protective sheets”, and the filling resin composition 500 ′ corresponds to “filling”. The adhesive layer 500 corresponds to “a cured product of the filling resin composition”.

100,100a Surface protective structure (surface protective structure of hardened cementitious structure)
200 Concrete building (hardened cement structure)
250 Out corner (corner)
250a Corner (corner)
251,251a Chamfered surface (corner surface)
300 Protective sheet 500 ′ Filling resin composition 500 Adhesive layer (cured product of filling resin composition)

Claims (6)

A pre-application step of pre-applying a filling resin composition containing a modified silicone resin on the corner surface of the hardened cementitious structure;
A pre-applied filling resin composition and an attaching step of attaching a protective sheet to the entire surface of the hardened cementitious structure, and
A method for protecting a surface of a cured cement structure, wherein the protective sheet includes a resin layer and a carbon film.   The method for protecting a surface of a hardened cementitious structure according to claim 1, wherein the filling resin composition has a viscosity of 150 Pa · s or more and 1000 Pa · s or less and a thixo index of 4.5 or more and 8.5 or less.   The method for protecting a surface of a hardened cementitious structure according to claim 1 or 2, wherein a product of an elastic modulus (GPa) and a thickness (µm) of the protective sheet is 200 or more and 900 or less.   The method for protecting a surface of a hardened cement structure according to any one of claims 1 to 3, further comprising a chamfering step of chamfering a corner portion of the hardened cementitious structure before the preliminary application step. Hardened cement structure,
A cured product of a filling resin composition containing a modified silicone resin provided on a corner surface of the cured cement structure,
A protective sheet provided on the entire surface of the cement hardened body structure and the cement hardened body structure,
The surface protection structure of a cement hardening body structure in which the said protection sheet contains a resin layer and a carbon film. The tensile strength of the cured product of the potting composition is 0.7 N / mm ^2, the surface protective structure of the hardened cement structure according to claim 5.