JP6947581B2 - Surface protection method for cement hardened structures and surface protection structure for cement hardened structures - Google Patents

Description

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

Concrete is gradually neutralized by carbon dioxide in the air. If the neutralization progresses to the inside of the concrete, the reinforcing bars will corrode and the strength of the concrete structure will be significantly reduced. Therefore, Japanese Patent Application Laid-Open No. 2003-342084 (Patent Document 1) and the like have proposed a technique of applying a coating material made of an epoxy resin composition or the like to the surface of a concrete structure to prevent the neutralization of concrete. ..

JP-A-2003-34284

In the construction method in which the coating material is applied to the surface of the concrete structure, it is necessary to sequentially form many layers such as primer, putty, undercoat, intermediate coat, and topcoat, and the time and labor required for the construction become a problem.

As a means for solving this problem, it is conceivable to manufacture a protective sheet in advance and attach the protective sheet to the surface of the concrete building. The protective sheet has certain elasticity and / or due to the need to ensure the protective ability that the protective sheet should exert, in order to easily cover the flat surface or curved surface that occupies most of the surface of the concrete structure without wrinkles. It usually has a thickness. However, such elasticity and thickness impair the ability to follow the surface of corners such as the inside and outside corners of concrete structures, thus causing workability problems. Further, due to the poor followability to the surface of the corner portion, the protective sheet floats at the corner portion. For example, as shown in FIG. 5, in the protruding corner 250 of the concrete building 200, the protective sheet 300 floats, resulting in poor construction. When the corners are protruding as shown in FIG. 5, the floating of the protective sheet also causes a poor appearance.

Therefore, an object of the present invention is a surface protection method that can be satisfactorily constructed without causing floating at the corners of the cement-hardened structure, and a surface protection method that can be satisfactorily constructed without floating at the corners of the cement-hardened structure. The purpose is to provide a surface protection structure.

The present invention includes the following inventions.
(1)
The surface protection method for a hardened cement structure of the present invention includes a pre-coating step and a pasting step. In the pre-coating step, a filling resin composition containing a modified silicone resin is pre-coated on the corner surface of the cement-cured structure. In the sticking step, the protective sheet is stuck on the entire surface of the pre-applied filling resin composition and the cement-cured structure. Further, the protective sheet is made of resin and the product of elastic modulus (GPa) and thickness (μm) is 200 or more and 900 or less.

As described above, even if the protective sheet conventionally has a predetermined combination of elastic modulus and thickness that causes poor followability to the corners and causes floating, the portion that has conventionally been floating is filled. Since it is filled with the resin composition for filling, the followability of the protective sheet to the corners is improved through the pre-applied filling resin composition. Therefore, the protective sheet can be satisfactorily fixed to the entire surface of the cement-cured structure including the corners. Further, by setting the product of the elastic modulus and the thickness of the protective sheet within a predetermined range, it is possible to cover the surfaces other than the corners with good appearance and good workability.

(2)
In the surface protection method for the hardened cement structure of (1) above, the filling resin composition may have 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. ..

By keeping the viscosity and the thixo index within a predetermined range in this way, workability is improved.

(3)
The surface protection method for the hardened cement structure according to (1) or (2) may further include a chamfering step for chamfering the corners of the hardened cement structure before the preliminary coating step.

As a result, the surface to be pre-applied can be well secured, and the protective sheet can be better fixed to the entire surface of the cement-cured structure including the corners.

(4)
The surface protection structure of the cement cured structure of the present invention includes a cement cured structure, a cured product of a filling resin composition containing a modified silicone resin provided on the corner surface of the cement cured structure, and cement. Includes a protective sheet provided over the entire surface of the hardened structure and the hardened cement structure. The protective sheet is made of resin and has a product of elastic modulus and thickness of 200 or more and 900 or less.

As described above, even if the protective sheet conventionally has a predetermined combination of elastic modulus and thickness that causes poor followability to the corners and causes floating, it is specified on the corner surface of the cement-hardened structure. By providing the cured product of the filling resin composition, the portion that has conventionally been floated is filled, so that the protective sheet can follow the corners through the cured product of the filling resin composition. Becomes good. Therefore, the protective sheet is well adhered to the entire surface of the cement-hardened structure including the corners. Further, by setting the product of the elastic modulus and the thickness of the protective sheet within a predetermined range, the appearance of the surface other than the corner portion is also good.

(5)
In the surface protection structure of the cement cured body structure of the above (4), the tensile strength of the cured product of the filling resin composition may be 0.7 N / mm ² or more.

When the cured product provided at the corner of the structure has a predetermined tensile strength in this way, a good protective state is maintained.

According to the present invention, a surface protection method that can be satisfactorily constructed without causing floating at the corners of the cement-hardened structure, and a surface protection method that can be satisfactorily constructed without floating at the corners of the cement-hardened structure. A surface protection structure is provided.

It is a schematic cross-sectional view explaining the surface protection construction method of the cement hardened body structure of 1st Embodiment. It is a continuation of FIG. It is a schematic cross-sectional view explaining the surface protection construction method of the cement hardened body structure of 2nd Embodiment. It is a continuation of FIG. It is a schematic cross-sectional view 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 designated by the same reference numerals, and their names and functions are also the same. Therefore, detailed explanations about them are basically not repeated.

[1. First Embodiment]
1 and 2 show a schematic cross-sectional view for explaining the surface protection structure of the cement hardened structure of the first embodiment and the surface protection method of the cement hardened structure for obtaining the surface protection structure. 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 is composed of concrete and a core material such as a reinforcing bar. Concrete is made by mixing water, gravel, sand, etc. with cement and hardening it by the hydration reaction of cement. The concrete structure 200 may be a new construction person or an in-service one. Examples of the concrete structure 200 include concrete viaducts (beams, columns, etc.), concrete girder bridges, electric columns, buildings, houses, and the like.

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

When the projected corner 250 of the concrete building 200 does not have the chamfered surface 251 as described above (when the projected corner 250 is a right angle in this embodiment), or because the chamfered surface 251 has only a small width, which will be described later. If floating occurs in the pasting step, a chamfering step of chamfering the protruding corner 250 by, for example, C-plane processing can be performed.

A base adjustment coating film may be provided in advance on the surface of the concrete structure 200. Examples of the base material adjusting paint include ethylene vinyl acetate resin-based, acrylic resin-based, and acrylic cation-based emulsions.

[1-2. Adhesive application process]
In the present embodiment, the adhesive resin composition 400'is applied to the entire surface of the concrete structure 200 to form a coating 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, epoxy adhesives, urethane adhesives, silicone adhesives, rubber adhesives and the like can be mentioned. Among these, the elastic adhesive can be selected in that it cushions the difference between the coefficient of linear expansion of the concrete structure 200 to be protected and the coefficient of linear expansion of the resin layer 310 of the protective sheet 300.

The adhesive resin composition 400'may be a so-called one-component resin composition or a two-component mixture of so-called two-component mixed resin compositions. In the case of a one-component resin composition, the work is easy and the work efficiency is good, and the uniformity of the adhesive resin composition to be cured is good, so that curing failure is unlikely to occur. Therefore, good adhesiveness can be easily obtained. The two-component mixed type 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-coating process]
In the pre-coating step, the filling resin composition 500'is applied to the chamfered surface 251 of the projected corner 250. In the illustrated embodiment, the filling resin composition 500'is applied via 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 on 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]
The filling resin composition 500'is an adhesive resin composition containing a modified silicone resin. Specifically, the filling resin composition 500'contains a modified silicone resin and a curing agent (specifically, a silanol condensation catalyst or the like), and may contain other resins and a curing agent thereof. One example is a resin composition containing a modified silicone, an epoxy resin, and a curing agent thereof.

The filling resin composition 500'may also be a so-called one-component resin composition or a two-component mixture of so-called two-component mixed resin compositions. In the case of a one-component resin composition, the work is easy and the work efficiency is good, and further, the uniformity of the filling resin composition to be cured is good, so that curing failure is unlikely to occur. Therefore, good adhesiveness can be easily obtained. The two-component mixed type 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-curable modified silicone resin that undergoes a condensation reaction due to 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 copolymerization component may be selected from the group consisting of an alkylene oxide component, an olefin component, an acrylic component, and another vinyl component.

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 viewpoint of elongation after curing and viscous ease of handling.
Examples of the olefin component include isobutylene.

Acrylate components include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, n-butyl (meth) acrylate, tert-butyl (meth) acrylate, cyclohexyl (meth) acrylate, and 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) Meta) acrylate, propylene glycol di (meth) acrylate, polypropylene glycol di (meth) acrylate, neopentyl glycol di (meth) acrylate, trimethylol propanetri (meth) acrylate, pentaerythritol di (meth) acrylate, pentaerythritol tri (meth) Meta) 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 (Meta) acrylate, 2-hydroxy-3-phenoxypropyl (meth) acrylate, pentaerythritol tri (meth) acrylate, 2-[(meth) acryloyloxy] ethyl 2-hydroxyethylphthalic acid, 2-[(meth) acryloyl Oxy] ethyl 2-hydroxypropylphthalic acid and the like can be mentioned. When the acrylic polymer is a copolymer of another vinyl monomer component, the hydrolyzable silicon group can be introduced by copolymerizing the vinyl monomer component having a hydrolyzable silicon group.

It is preferable that the main chain contains an acrylic unit in terms of good weather resistance. Further, 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 halide silyl group, an alkenyloxysilyl group, an asyloxysilyl group, an aminosilyl group, an aminooxysilyl group, an oximsilyl group, an amidesilyl group, and an alkoxysilyl group. Here, the number of hydrolyzable groups bonded to the silicon atom 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 a plurality of kinds. Further, a hydrolyzable group and a non-hydrolyzable group may be bonded to one silicon atom. As the hydrolyzable silicon group, an alkoxysilyl group such as a monoalkoxysilyl group, a dialkoxysilyl group, or a trialkoxysilyl group is preferable because it has excellent stability and is easy to handle.
The modified silicone resin 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. 3,000 or less, or 4,000 or more and 30,000 or less. It is preferable that it is at least the above lower limit value because the curing time of the filling resin composition is short or the adhesive strength after curing is good. It is preferable that it is not more than the above upper limit value because the viscosity of the filling resin composition is appropriate and the handleability is good.

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

Examples of the monoalkyl tin ester include butyl tin tris (2-ethylhexanoate), and examples of the dialkyl tin ester include dibutyl tin acetate, dibutyl tin dilaurate, dibutyl tin dioctate, dibutyl tin diolate, and dibutyl tin. Examples thereof include dimethoxydo, dibutyltin diphenoxide, dibutyltin diacetylacetonate, dibutyltin acetoacetate, and stannous octanoate.
Examples of the organic titanate include titanium alkoxides such as tetrabutyl titanate, tetraisopropyl titanate, tetramethyl titanate, tetra (2-ethylhexyl titanate) triethanolamine titanate, titanium tetraacetylacetonate, titanium ethylacetacetate, and octylene glycote. Examples include titanium chelates such as rate.
The silanol condensation catalyst may be used alone or in combination of two or more.

The content of the silanol condensation catalyst in the adhesive resin composition is 0.1 part by weight or more and 10 parts by weight or less, preferably 1 part by weight or more and 5 parts by weight or less with respect to 100 parts by weight of the modified silicone resin. It is preferable that it is at least the above lower limit value from the viewpoint of shortening the curing time. It is preferable that it is not more than the above upper limit value from the viewpoint of ensuring physical properties such as adhesive strength.

When the filling resin composition 500'contains an epoxy resin, the epoxy resin is not particularly limited as long as it is a resin having an epoxy group. Specific examples thereof include compounds 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 effect of suppressing neutralization, it is preferable that it contains an aromatic compound.

Examples of the epoxy resin include bisphenol A type, bisphenol F type, bisphenol S type and bisphenol type epoxy resins such as hydrogenated products thereof; glycidyl ether type epoxy resins such as polypropylene glycol diglycidyl ether type epoxy resin; Ester type epoxy resins such as glycidyl ester type epoxy resins; Novorak type epoxy resins such as phenol novolac type and cresol novolak type, bisphenol A novolak type epoxy resins and their hydrogenated products; Triphenol type such as triphenol methane type epoxy resins Polyfunctional epoxy resin of Epoxy resin; Dicyclopentadiene type epoxy resin; Ether ester type epoxy resin; Epoxy resin having an alicyclic structure such as 3,4-epoxycyclohexylmethyl-3', 4'-epoxycyclohexanecarboxylate; Urethane type epoxy resin; A rubber modified epoxy resin having a rubber skeleton such as polybutadiene and acrylonitrile butadiene rubber (NBR) can be used.
One type of epoxy resin may be used alone, or two or more types may be used in combination.

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, based on 100 parts by weight of the modified silicone resin. When it is at least the above lower limit value, good toughness can be obtained in the adhesive layer 400 after curing, and when it is at least the above upper limit value, good elasticity can be obtained in the adhesive layer 400 after curing. Therefore, cracks in the protective sheet 300 can be preferably suppressed.

Examples of the epoxy curing agent include amine compounds. Examples of the amine compound include aliphatic tertiary amines such as N, N-dimethylpropylamine, N, N, N', N'-tetramethylhexamethylenediamine, N-methylpiperidine, N, N'-dimethylpiperazine and the like. Arocyclic tertiary amines such as alicyclic tertiary amines, benzyldimethylamine, dimethylaminomethylphenol, 2,4,6-tris (dimethylaminomethyl) phenol, ethylenediamine, diethylenetriamine, triethylenetetramine, pentaethylene Aliper diamines such as hexamin, trimethylenediamine, hexamethylenediamine, tetramethylenediamine, alicyclic diamines such as 1,3-bis (aminomethyl) cyclohexane, isophoronediamine, norboldendiamine, diaminodiphenylmethane, Examples include aromatic diamines such as metaphenylenediamine.
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 in which the active amine is blocked and activated under a predetermined condition such as moisture. For example, ketimine is stable in the absence of water, but is generally a primary amine due to the presence of water and reacts with epoxy resins. Specifically, 2,5,8-triaza-1,8-nonadien, 2,10-dimethyl-3,6,9-triaza-2,9-undecadien, 2,10-diphenyl-3,6,9 --Triaza-2,9-Undecadien, 3,11-Diene-4,7,10-Triaza-3,10-Tridecadene, 3,11-Diethyl-4,7,10-Triaza-3,10-Tridecadien, 2 , 4,12,14-Tetramethyl-5,8,11-Triaza-4,11-Pentadecadiene, 2,4,20,22-Tetramethyl-5,12,19-Triaza-4,19-Tri Eikosaziene, 2,4,15,17-tetramethyl-5,8,11,14-tetraaza-4,14-octadecaziene and the like.
The epoxy curing agent 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, preferably 30 parts by weight or more and 50 parts by weight or less, based on 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 moles of epoxy groups in the epoxy resin (total number of moles of epoxy groups / total number of active amino groups) with respect to the total number of moles of active amino groups generated by activation. 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 that it is at least the above lower limit value from the viewpoint of elastic modulus of the cured film, and it is preferable that it is at least the above upper limit value from the viewpoint of storage stability.

The filling resin composition 500'may further contain other additives, if necessary. Other additives include dehydrating agents, antioxidants, fillers, plasticizers, sagging agents, UV absorbers, pigments, solvents, fragrances and the like.

As the above-mentioned filling resin composition 500', a non-heated or heated one to which water is further added may be used. When heated, the temperature can be, for example, 40 degrees or more and 80 degrees or less. It is preferable that it is at least the above lower limit value from the viewpoint of obtaining sufficient adhesive strength in a short time. It is preferable that it is not more than the above upper limit value from the viewpoint of preventing damage to the protective sheet 300.

[1-3-2. Physical characteristics 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 at least the above lower limit value in terms of resistance to dripping, and it is preferable that the viscosity is at least the above upper limit value in terms of ease of application. Further, when the viscosity is equal to or higher than the above lower limit value, the thickness of the coating film of the filling resin composition 500'can be appropriately secured, and when it is equal to or lower than the above upper limit value, the thickness of the coating film of the filling resin composition 500'can be appropriately secured. It is preferable in that the peeling of the protective sheet 300 can be suppressed more effectively because the adhesiveness of the protective sheet 300 is improved. In this specification, the viscosity is determined by using a B-type viscometer as a single cylindrical viscometer in accordance with JIS Z 8803. It is a value measured at 7 rotors and 23 ° C. By keeping the viscosity within the above range, workability is improved.

Further, the thixoindex (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 thixoindex, a BS viscometer was used, and No. The viscosity measured under the condition of 1 rpm of 7 rotors was measured using the BS viscometer to obtain the No. It is obtained as the value divided by the viscosity measured under the condition of 10 rpm of 7 rotors. By setting the chixo 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 structure 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 attached so that the bent surface becomes smooth. Since the layer of the filling resin composition 500'is provided, the portion that has conventionally been floated is filled with the filling resin composition 500'and that of the filling resin composition 500' is filled by this step. Since the surface can be formed into a gentle and smooth shape, the protective sheet 300 has good followability to the protruding corner 250.

[1-4-1. Protective sheet]
The protective sheet 300 includes a resin layer 310 and a functional layer 350. In the present embodiment, the resin layer 310 side of the protective sheet 300 is attached so as to face the concrete structure 200, but the present embodiment is not limited to this embodiment. In the present invention, the side of the functional layer 350 of the protective sheet may be attached so as to face the concrete structure 200.

The product of the elastic modulus (GPa) and the thickness (μm) of the protective sheet 300 is 200 or more and 900 or less, preferably 300 or more and 900 or less. When the product is at least the above lower limit value, wrinkles can be easily prevented from occurring in the covering portion of the surface of the concrete building 200 (particularly the entire wide area other than the chamfered surface 251), and below the above upper limit value. This makes it possible to easily prevent the protective sheet 300 from floating in the covered portion of the protruding corner 250.

Specifically, the elastic modulus of the protective sheet 300 may be 0.7 GPa or more and 7 GPa or less, preferably 1 GPa or more and 7 GPa or less, and more preferably 2 GPa or more and 6 GPa or less as measured according to ASTM D 882. It is preferable that the elastic modulus is at least the above lower limit value because the protective sheet 300 has good elasticity and it is easy to suppress the occurrence of wrinkles, and when it is at least the above upper limit value, it is easy to suppress the occurrence of floating. preferable. 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. It is preferable that the thickness is at least the above lower limit value because the protective sheet 300 has good elasticity and it is easy to suppress the occurrence of wrinkles, and when it is at least the above upper limit value, it is easy to suppress the occurrence of floating. 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, manufactured by Shimadzu Corporation, UV-2600). When the protective sheet 300 has such an ultraviolet barrier property, the protective sheet 300 itself deteriorates, the cured product (adhesive layer 400) of the adhesive resin composition 400'and the resin composition 500' for filling (adhesive layer 500'). ) And / or deterioration of the concrete 210 can be preferably suppressed.

[1-4-2. Resin layer]
The material of the resin layer 310 may be any resin, and polyester resin (polyethylene terephthalate, polyethylene naphthalate, etc.), polyamide resin (nylon, etc.), polycarbonate resin, acrylic resin, phenol resin, melamine resin, epoxy resin, urea resin, etc. Examples thereof include vinyl chloride resin and polyolefin resin (polyethylene, polypropylene, etc.).
Among these, the polyester resin is preferable because the elastic modulus and the thickness can be designed within the above-mentioned predetermined ranges and the individual values can be easily designed with good values.

The coefficient of linear expansion 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, and more preferably 3 × 10 ^-5 / K or less. , More preferably 2 × 10 ^-5 / K or less, and even more preferably 1.5 × 10 ^-5 / K or less. It is preferable that the value is not less than the above upper limit value from the viewpoint of preventing the resin layer 310 itself from cracking and preventing the functional layer 350 from cracking. The lower limit within the range of the coefficient of linear expansion is not particularly limited, but is preferably 0 / K.

[1-4-3. Functional layer]
The functional layer 350 is a layer different from the resin layer 310, or a surface-modified layer formed by modifying the surface of the resin layer 310.
The functional layer 350 is preferably a layer having a function of improving the performance of the protective structure, and examples of the function include weather resistance (ultraviolet ray blocking property) and gas barrier property. Specific examples of the functional layer 350 include a fluorine coating layer and an acrylic coating layer for imparting weather resistance, and a silica-based coating layer for imparting gas barrier properties.

[1-5. Surface Protective Structure of Cement Hardened Structure] After the pasting step is completed, it is cured 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 formed 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') of the concrete structure 200 including the protruding corner 250. It adheres firmly to the entire surface to form the surface protection structure 100. At 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 good.

The protruding corner 250 of the surface protection structure 100 is susceptible 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 the modified silicone resin, the load applied to the projected corner 250 can be absorbed by its elasticity. Therefore, the surface protection structure 100 is well maintained in a protected state in an actual use environment.

The tensile strength of the cured product of the filling resin composition 500'forming the adhesive layer 500 in accordance with JIS K6251 may be, for example, 0.7 N / mm ² or more, preferably 1.0 N / mm ² or more. As a result, the 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 structure 200) is excellent, 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 protected state is maintained in a good state.

The tensile strength of the cured product of the filling resin composition 500'forming the adhesive layer 500 in accordance with JIS K6251 is, for example, 0.5 times or more and 1 time or less, 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 at least the above lower limit in that it follows the adhesive layer 400 well and the state of adhesion with the adhesive layer 400 is maintained, and it is appropriate that it is at least the above upper limit. It is preferable in that the rigidity is ensured and the protected state is maintained well.

The elongation of the cured product of the filling resin composition 500'forming the adhesive layer 500 in accordance with JIS K6251 may be, for example, 10% or more, preferably 150% or more, and more preferably 300% or more. As a result, the 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 structure 200) is excellent, and the protective state is maintained well. The upper limit of the elongation rate of the adhesive layer 500 is not particularly limited, and a larger one is preferable.

The elongation rate of the cured product of the filling resin composition 500'constituting the adhesive layer 500 in accordance with JIS K6251 is, for example, 1.5 times or more and 4 times or less, preferably 1.6 times the elongation rate of the adhesive layer 400. It may be 3.7 times or more or less. It is preferable that the elongation rate of the adhesive layer 500 is at least the above lower limit in that it follows the adhesive layer 400 well and the state of adhesion with the adhesive layer 400 is maintained, and that it is at least the above upper limit is appropriate rigidity. It is preferable in that the protection state is maintained in a good state.

[1-6. Modification example]
A net-like sheet may be interposed between the concrete structure 200 and the protective sheet 300. The reticulated sheet may be embedded in the layer of the adhesive resin composition 400'or the layer of the adhesive resin composition 400'and the filling resin composition 500'. This further strengthens the protective structure 100.

The net-like sheet is not particularly limited as long as it is a sheet made of long fibers and having communication holes (that is, meshes) that communicate with each other in the thickness direction. When the adhesive resin composition 400'or the adhesive resin composition 400'and the filling resin composition 500' enter the mesh, the protective strengthening ability is enhanced.

The reticulated sheet may be composed of fibers such as vinylon fiber, polyester fiber, polypropylene fiber, polyethylene fiber, carbon fiber, aramid fiber, glass fiber and basalt fiber. In particular, polypropylene fibers and vinylon fibers are preferable, and vinylon fibers are more preferable, from the viewpoints of protective strengthening ability, flexibility, resin composition, adhesive layer 400, or adhesiveness and practicality with adhesive layers 400, 500. Further, glass fiber (glass cloth) is more preferable from the viewpoint of practicality and protective strengthening ability.

Specific embodiments of the net-like sheet include mesh, woven fabric, knitted fabric (net) and non-woven fabric, and one of these can be used alone or in combination of two or more. Among these, the mesh is preferable from the viewpoint of the ability to prevent peeling. In the present invention, the mesh refers to a base material having a structure in which a plurality of continuous fiber bundles are cross-laminated and the fiber bundles are preferably bonded to each other at the intersecting portions. Specific examples thereof include 2-axis mesh (lattice mesh), 3-axis mesh, 4-axis mesh, 5-axis mesh, and more multi-axis mesh (multidimensional mesh), from the viewpoint of more preferable peeling prevention ability. Therefore, it is preferable to use a multi-axis mesh having three or more axes. The triaxial mesh is preferably a multiaxial mesh laminated in three directions of the warp direction, the oblique direction, and the reverse oblique direction, specifically, so that the crossing angle of the fiber bundles is 60 degrees. More specifically, Kumifu (registered trademark) can be mentioned.

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

3 and 4 show a schematic cross-sectional view for explaining the surface protection structure of the cement hardened structure of the second embodiment and the surface protection method of the cement hardened structure for obtaining the surface protection structure.
In the present embodiment, the portion of the concrete structure 200 including the inside corner 250a is protected. In this embodiment, the inside corner 250a has a chamfered surface 251a. As a result, the filling resin composition is applied to the entire inside 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 inside corner 250a by the preliminary coating step. do. In the illustrated embodiment, the filling resin composition 500'is applied via 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 on the chamfered surface 251a, and the filling resin composition 500' may be directly applied to the chamfered surface 251a.

As shown in FIG. 4, the protective sheet 300 is integrally covered with the chamfered surface 251a of the inside corner 250a and both surfaces thereof by the attaching process. At this time, the protective sheet 300 is attached so that the bent surface becomes smooth. Then, it is cured to cure the coating layer of the adhesive resin composition 400'and the layer of the filling resin composition 500', and the protective sheet 300 adheres to the adhesive layer 400 (cured product of the adhesive resin composition 400'). The surface protection structure 100a adhered by the layer 500 (cured product of the filling resin composition 500') is formed. At the inside 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. Therefore, even at the inside corner 250a, the protective sheet 300 is strong without floating. It is glued to.

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

Hereinafter, the present invention will be described with reference to examples, but the present invention is not limited to these examples.

[Examples 1 to 5]
As a test piece of the cement-hardened structure, a box culvert having a width of 600 mm × 600 mm × 2000 mm and a width of about 30 mm on the C surface was prepared.
As a resin composition for filling, an adhesive resin composition containing modified silicone (manufactured by Sekisui Fuller Co., Ltd., developed product number A-430C) was prepared. The viscosity of this filling resin composition (value measured at No. 7 rotor, 23 ° C. using a B-type viscometer as a single cylindrical viscometer in accordance with JIS Z 8803) was 500 Pa · s. Chixo 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) The tensile strength of the cured product in accordance with 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 of this laminated sheet according to ASTM D 822 was 0.8 GPa, 4.7 GPa, or 6 GPa.

An adhesive resin composition (manufactured by Sekisui Fuller Co., Ltd., developed product number A-430T) was applied to the entire surface including the outer corner (outer corner side) 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 portion with a coating thickness of about 1.0 mm. Then, a protective sheet was attached and cured to obtain a surface protective structure of box culvert.

Table 1 summarizes the constituent resin of the protective sheet, the thickness, the product of the elastic modulus (GPa) and the thickness (μm), and the construction evaluation (presence or absence of floating in the corners, presence or absence of wrinkles in the parts other than the corners).

As shown in Table 1, no floating of the corners occurred in all the examples. Among Examples 1 to 5, in Examples 1, 2, 3 and 5, as compared with Example 4, the protective sheet is handled and the corners are not lifted and wrinkles are generated on the surface other than the corners. It was especially easy to finish without letting it go.

[Comparative Examples 1 to 8]
Comparative Examples 1 to 5 obtained box culvert surface protection structures in the same manner as in Examples 1 to 5, respectively, except that the filling resin composition was not used. In Comparative Examples 6 to 8, a box culvert surface protective structure was obtained in the same manner as in Examples 1 to 5, except that the resin and the protective sheet having the thickness shown in Table 2 were used, respectively. The elastic modulus of the protective sheet used in Comparative Example 8 was 0.8 GPa.
Table 2 summarizes the constituent resin of the protective sheet, the thickness, the product of the elastic modulus (GPa) and the thickness (μm), and the construction evaluation (presence or absence of floating at the corners, presence / absence of wrinkles at the portions other than the corners).

As shown in Table 2, in Comparative Examples 1 to 5, floating occurred at the corners. In Comparative Examples 6 to 8, wrinkles occurred.

Preferred embodiments of the present invention are as described above, but the present invention is not limited thereto, and various other embodiments that do not deviate from the gist of the present invention are made.

[Correspondence between each part of the embodiment and each component of the claim]
In the present specification, the surface protection structures 100 and 100a correspond to the "surface protection structure of the cement hardened structure" of the claim, the concrete structure 200 corresponds to the "cement hardened structure", and the outside corner 250 and The inside corner 250a corresponds to the "corner", the chamfered surfaces 251,251a correspond to the "corner surface", the protective sheet 300 corresponds to the "protective sheet", and the filling resin composition 500'corresponds to the "filling". The adhesive layer 500 corresponds to the "resin composition" and corresponds to the "cured product of the filling resin composition".

100,100a Surface protection structure (surface protection structure of cement hardened structure)
200 Concrete structure (hardened cement structure)
250 Outer corner (corner)
250a inside 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 (3)

A pre-coating step of pre-coating a filling resin composition containing a modified silicone resin and an epoxy resin on the corner surface of the cement-cured structure.
Includes a pre-applied filling resin composition and a sticking step of sticking a protective sheet over the entire surface of the cement-cured structure.
A surface protection method for a hardened cement structure, wherein the protective sheet is composed of a laminate containing a resin layer and a DLC film, and the product of elastic modulus (GPa) and thickness (μm) is 200 or more and 900 or less. The surface protection method for a hardened cement structure according to claim 1, further comprising a chamfering step for chamfering the corners of the hardened cement structure before the pre-coating step. Cement hardened structure and
A cured product of a filling resin composition containing a modified silicone resin and an epoxy resin provided on the corner surface of the cement cured body structure, and
Includes a protective sheet provided on the entire surface of the cured cement structure and the cured resin composition for filling.
A surface protective structure of a cement-cured structure in which the protective sheet is composed of a laminate containing a resin and a DLC film and the product of elastic modulus and thickness is 200 or more and 900 or less.

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