JP4357929B2 - Concrete floor structure and construction method thereof - Google Patents

Description

The present invention relates to a concrete floor structure for a building having excellent interlayer adhesion strength, particularly a public facility such as a hospital, a school, or a station, a precision instrument factory, a convenience store, a condominium, and the like, and a construction method thereof.

Conventionally, in the construction field, in order to obtain a floor surface without unevenness, after placing slab concrete, a poorly mixed mortar is poured onto it to form a foundation, and then a self-leveling material is spread on the foundation. The construction method is known. (Patent Document 1)
Further, after a concrete floor is placed, a primer treatment is performed thereon to use a self-leveling material, a drying inhibitor is applied thereon, and a floor finishing method using a finishing material is known. (Patent Document 2)
Japanese Examined Patent Publication No. 7-68757 JP 2003-213915 A

However, in the construction method disclosed in the above example, a problem of blistering due to peeling occurs due to insufficient adhesive strength between the concrete surface and the primer. As a result of this blistering, there is a problem that irregularities occur, a beautiful floor surface cannot be obtained, and the appearance of the floor surface is impaired. In order to solve the above-mentioned problems, the present invention is a concrete having excellent surface appearance and adhesive strength between the layers constituting the floor by providing a cured layer of a self-leveling material having excellent surface appearance and adhesion strength on the floor surface. An object of the present invention is to provide a concrete floor structure excellent in surface appearance and its construction method, without causing a problem of blistering due to peeling by obtaining a floor structure.

As a result of diligent research to achieve the above-mentioned problems, the present inventors are able to obtain a floor having excellent adhesive strength by adopting a concrete floor structure having a specific layer structure and a construction method for the structure. Thus, the inventors have found that the problem can be solved and have reached the present invention.

That is, the present invention includes at least (E) a cement concrete floor layer, (D) a cured product layer obtained by curing a mixture of cement concrete and an acrylic emulsion, and (C) curing of an acrylic primer for a self-leveling material. And (B) a hardened material layer of a cement-based self-leveling material, the (B) layer on the (C) layer, the (C) layer on the (D) layer, The (D) layer provides a concrete floor structure of a building which is sequentially laminated on the (E) layer. In many cases, the (A) surface layer is provided on the (B) layer.

Further, preferably, the building is a building such as a public facility such as a hospital, a school, a station, a precision instrument factory, a convenience store, an apartment, etc., preferably for the self-leveling material of the cured product layer (C). The primer is an acrylic emulsion, preferably the hardened material layer (D) is a hardened material obtained by mixing 1-10% by weight of an acrylic emulsion with cement concrete, and further cement concrete. Place on the floor, spray acrylic acrylic before curing, form a hardened layer of cement concrete and acrylic emulsion, and apply acrylic primer for self-leveling material on the polymer concrete layer. Concrete floor, which is constructed and then constructed with cement-based self-leveling material It is to provide a construction method. In addition, you may construct a surface layer further on the hardened | cured material layer of a cement type self-leveling material after constructing a cement type self-leveling material.

By adopting a specific structure, it has excellent adhesion strength between the concrete surface and the self-leveling material, so there is no problem of blistering due to peeling, and a beautiful floor with no irregularities on the floor surface. Since the surface can be formed, it is possible to construct a floor structure having an excellent floor surface appearance. The obtained floor structure is most suitable as a floor of a building such as a public facility such as a hospital, a school, or a station, a precision instrument factory, a convenience store, or an apartment.

The surface material of the (A) layer is a floor paint, a floor material sheet, a carpet, a flooring and the like. Floor material sheets, carpets, flooring, and the like are attached to the (B) layer with an adhesive. The floor coating is usually applied by applying directly on the layer (B).

The (B) layer refers to a cured product layer of a cement-based self-leveling material. The cement-based self-leveling material used to form the layer is basically composed of a hydraulic component, a setting modifier, a water reducing agent, And a composition comprising a thickener. Examples of the hydraulic component used in the cement-based self-leveling material include alumina cement, Portland cement, gypsum, blast furnace slag, and the like.

First, the hydraulic component will be described. Alumina cement is potentially hard. In addition, calcium sulfate aluminate hydrate is produced by the coexistence of sulfate such as gypsum, which not only accelerates initial curing and enables early opening, but also consumes a large amount of moisture in the cured body at an early stage. For this reason, the time required to shift to surface finishing material construction is shortened, and a cured body with less shrinkage is formed. Further, due to the presence of blast furnace slag having latent hydraulic properties, a decrease in strength of the cured body over time, which is a defect of alumina cement, is also suppressed. Several types of alumina cements having different mineral compositions are known and commercially available, but the main component is monocalcium aluminate, and any commercially available product can be used regardless of the type.

Portland cement is one of the important components in fast setting, and it promotes the formation of calcium sulfoaluminate hydrate together with alumina cement and gypsum, thereby extracting the potential fast setting of alumina cement. Portland cement includes ordinary Portland cement, early-strength Portland cement, ultra-early strong Portland cement, medium heat Portland cement, low heat Portland cement, sulfate-resistant Portland cement, white Portland cement, blast furnace cement, fly ash cement, silica cement, etc. These various mixed cements can be used alone or in combination of two or more.

Gypsum is a component necessary for maintaining fast curing, quick drying, and dimensional stability after curing. In addition, gypsum can be used as a mixture of two or more kinds of gypsum, such as anhydrous, two-water, and half-water, regardless of the type. Since the blast furnace slag has a small drying shrinkage, it not only enhances the crack resistance of the cured body, but also has an effect of improving the strength of the cured body due to its latent hydraulic properties. Moreover, it has the effect of suppressing the strength reduction resulting from the transition of the alumina cement hydrate.

As a setting speed adjusting agent, by adding a setting accelerator and a setting retarder in combination, for example, fluid retention that enables a working time of 30 minutes or more, and quick hardening thereafter, It is possible to ensure fast-hardening and quick-drying that enables walking and construction of finishing materials within 3 days, as well as surface powder caused by slurry movement and surface layer wrinkles, bubble voids, poor surface hardening at low temperatures, etc. , The risk of cracking during condensation at high temperatures is reduced, and a cured product having good surface properties can be obtained. Furthermore, it is possible to achieve both the above-mentioned super-fast hardness, fluidity retention and excellent cured product properties in a wide range from low temperature to high temperature.

Lithium salts that act as setting accelerators include inorganic acid salts such as lithium carbonate, lithium chloride, lithium sulfate, lithium hydroxide, lithium nitrate, and lithium oxalate, lithium acetate, lithium citrate, lithium tartrate, lithium malate, glycol Organic acid salts such as lithium acid can be mentioned.

As the setting accelerator, tartaric acid, citric acid, bicarbonate, malic acid, gluconic acid, malic acid and other oxycarboxylic acids, phosphoric acid, or alkali metal salts or alkaline earth salts thereof, or a predetermined amount It may be added. It should be noted that if the amount added is large, fluidity may be deteriorated, poor curing may occur, or surface defects may occur due to the generation of breathing water.

The most basic factor that a self-leveling material should have is high fluidity. It is necessary to lower the water / hydraulic component ratio in order to suppress material separation and obtain a high-strength cured body. However, in order to ensure high fluidity even if the water / hydraulic component ratio is lowered, water is reduced. Addition of the agent is essential. Commercially available products such as naphthalene-based, polycarboxylic acid-based, polyether-based, and melamine-based water reducing agents can be used regardless of their types.

In order to suppress material separation to a sufficient level while ensuring high fluidity, it is preferable to add a thickener. As the thickening agent, celluloses such as methylcellulose and carboxymethylcellulose, proteins such as gelatin and pectin, water-soluble polymers such as polyethylene glycol, polyethylene oxide, polyacrylamide, and polyvinyl alcohol can be used.

In the case of a cement-based self-leveling material prepared by blending the above hydraulic components, setting speed modifier, water reducing agent and thickener, it is excellent in fluidity, fast curing, and excellent curing characteristics. In this invention, it can use suitably. Moreover, what added an antifoamer, polymer emulsion, polymer resin powder, etc. can be used as needed. As the antifoaming agent, known substances such as silicon-based, alcohol-based, polyether-based synthetic substances, or plant-derived natural substances can be used.

The polymer emulsion can improve adhesion to the base concrete, crack resistance, and wear resistance of the cured body. Copolymers such as ethylene-vinyl acetate, styrene-butadiene, acrylonitrile-butadiene as polymer emulsions, or homopolymers such as polybutene, polyvinyl chloride, polyvinyl acetate, methyl (meth) acrylate, ethyl (meth) One or two or more kinds of (meth) acrylate compounds such as acrylate, butyl (meth) acrylate, alkyl (meth) acrylate such as 2-ethylhexyl (meth) acrylate, and styrene copolymerizable with these monomers Commercially available and synthetic products such as (meth) acrylate resins copolymerized with vinyl compounds such as vinyl acetate and vinylidene chloride can be used regardless of the type. Here, (meth) acrylate means acrylate and methacrylate.

For the cement-based self-leveling material, it is also possible to use a material to which fly ash, limestone powder, siliceous powder or the like is added as an extender. The effect of improving the fluidity can be obtained by adding the extender, but if the amount added is too large, the strength development will be reduced, so that sufficient attention should be paid to the amount added.

It is preferable to use a cement-based self-leveling material with the addition of fine aggregate / extension material because it can be used to take advantage of its properties. As fine aggregate, quartz sand, river sand, sea sand, lime and stone sand can be used. In addition, it shows in the following Table 1 about one compounding example of each component of the cement-type self-leveling material which can be used for this invention. The amount of each component may be selected in consideration of construction conditions and the like. Of course, a commercially available cement-based self-leveling material may be used. However, it is preferable to select and use a material having a preferable blending ratio of each component after testing in advance for compatibility with other layers.

(C) The acrylic primer for self-leveling material used for forming the layer is preferably an acrylic polymer having a glass transition temperature of −50 to −1 ° C., and 1 to 10% by weight of acrylic acid and / or methacrylic acid. contains. Other constituent components are acrylic acid ester and methacrylic acid ester, but it is preferable to copolymerize a compound having a plurality of functional groups in one molecule. Examples of the compound having a plurality of functional groups include trimethylolpropane trimethacrylate, glycidyl acrylate, glycidyl methacrylate, bisphenol A polyoxyethylene adduct diacrylate, bisphenol A polyoxyethylene adduct dimethacrylate, triallyl isocyanurate, N -Methylolacrylamide, N-methylolmethacrylamide, divinylbenzene and the like can be used, but N-methylolacrylamide, N-methylolmethacrylamide or trimethylolpropane trimethacrylate is preferred. These compounds are preferably used in the range of 0.1 to 5% by weight in the polymer.

Further, the polymer raw material is an amount of an unsaturated monomer other than the above, for example, styrenes such as styrene and α-methylstyrene, dienes such as butadiene and isoprene, vinyl acetate and propion in an amount within a range not impairing performance. Vinyl esters such as vinyl acid, and nitriles such as acrylonitrile and α-methylacrylonitrile may be used in combination. As the acrylic primer for the self-leveling material, commercially available products such as U primer Q manufactured by Ube Industries, Ltd. can be suitably used.

The layer (D) refers to a layer formed by curing a mixture of cement concrete and an acrylic emulsion. The formation of the layer is performed by applying a mixture of cement concrete and an acrylic emulsion on the existing concrete surface. Although application is possible, it is preferable to form a polymer cement concrete layer by spraying an acrylic emulsion on the surface immediately after placing concrete. As such an acrylic emulsion, for example, commercially available products such as FF-30 manufactured by Dainippon Ink & Chemicals, Inc. can be suitably used.

(D) The acrylic emulsion used for layer formation preferably has a glass transition temperature of 0 to 20 ° C., a solid content of 20 to 45% by weight, and is obtained by emulsion polymerization. The emulsion preferably contains 1 to 5% by weight of methacrylic acid, and is composed of acrylic acid ester and methacrylic acid ester as other components.

The acrylic acid ester and the methacrylic acid ester form a main part of the polymer skeleton in the polymer concrete, have good alkali resistance and weather resistance, and preferably have 1 to 12 carbon atoms. For example, methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, n-butyl acrylate, n-butyl methacrylate, iso-butyl acrylate, iso-butyl methacrylate, tert-butyl acrylate, methacrylic acid One or two or more of tert-butyl, 2-ethylhexyl acrylate, 2-ethylhexyl methacrylate, lauryl acrylate, and lauryl methacrylate can be mixed and used. If the alkyl carbon number of the acrylic ester and methacrylic ester exceeds 12, the viscosity of the emulsion polymer emulsion may increase and it may be difficult to spread the emulsion on the concrete surface.

The above methacrylic acid improves the affinity between cement concrete and emulsion polymer, improves the familiarity of acrylic ester and methacrylate emulsion polymer with concrete, and can mix cement concrete and emulsion uniformly. As a result, a dense layer of polymer cement concrete can be formed. The amount of methacrylic acid added to the raw material is preferably 1 to 5% by weight. If it is less than 1% by weight, the affinity between the concrete and the emulsion cannot be sufficiently improved. On the other hand, if it exceeds 5% by weight, curing of the concrete is delayed, which is not preferable.

In the monomer mixture, an aromatic α, β-monoethylenic monomer and an emulsion polymer obtained by copolymerizing a small amount of α, β-monoethylenic polar monomer other than methacrylic acid were added. It may be an emulsion.

The above-mentioned aromatic α, β-monoethylenic monomer is preferably added in an amount of 0 to 20% by weight to reduce the viscosity of the acrylic ester and methacrylic ester, and improve the surface finish of the concrete after spraying the emulsion. Workability is improved. Examples of the aromatic α, β-monoethylenic monomer include styrene and 1,2,1,3, or 1,4-vinyltoluene. It can be used in addition to the mixture.

An α, β-monoethylenic polar monomer other than methacrylic acid may be copolymerized. The action of methacrylic acid that enhances the affinity between the emulsion and the concrete can be strengthened.

Examples of the α, β-monoethylenic polar monomer include acrylonitrile, methacrylonitrile, vinylpyrimidine, vinylpyrrolidone, hydroxyalkyl arylate, acrylamide, methacrylamide, N-methylolacrylamide, N-methylolmethacrylamide or These derivatives are mentioned, and at least one of these can be added to the monomer mixture and copolymerized.

The addition amount of the α, β-monoethylenic polar monomer in the monomer mixture is 0 to 5% by weight. If added in excess of 5% by weight, the effect of improving the affinity with concrete is enhanced, but there are many cases where the curing of the concrete is significantly delayed, which is not preferable. In particular, the amount of the α, β-monoethylenic polar monomer added to the monomer mixture is preferably 0 to 2% by weight.

Examples of the protective colloid that stabilizes the micelles of the copolymer during emulsion polymerization of the monomer mixture of the constituent raw materials include polyvinyl alcohol, protein, and gelatin, and it is particularly desirable to use polyvinyl alcohol. One or more of these are used to emulsion polymerize the monomer mixture.

The amount of the protective colloid is preferably 1 to 20 parts by weight with respect to 100 parts by weight of the raw material monomer mixture. If the amount is less than 1 part by weight, the polymer concrete layer is insufficiently formed due to agglomeration due to electrolyte ions, resulting in insufficient water retention on the concrete surface, and the emulsion of the emulsion polymer becomes unstable during storage and agglomerates. There is a risk of doing. On the other hand, when the amount exceeds 20 parts by weight, the viscosity of the emulsion of the emulsion polymer increases, which hinders the mixing workability with the concrete after the emulsion is sprayed.

Examples of the polyvinyl alcohol include fully saponified polyvinyl alcohol, partially saponified polyvinyl vinyl alcohol, and anionized polyvinyl alcohol obtained by modifying a part of polyvinyl alcohol with a carboxyl group, a sulfonyl group, or the like. Either completely saponified or partially saponified polyvinyl alcohol can be used regardless of the type, but considering the emulsifying power during emulsion polymerization, those having a saponification rate of 70 to 100% and an average polymerization degree of 300 to 3000 are preferable. These 1 type or 2 or more types of mixtures are used in 1-20 weight part with respect to 100 weight part of raw material monomer mixtures.

The copolymer is obtained by ordinary emulsion polymerization. At this time, examples of the emulsifier used in combination with the protective colloid include an anionic emulsifier, a nonionic emulsifier, a cationic emulsifier, and other reactive emulsifiers. However, it is usually preferable to use an anionic emulsifier and a nonionic emulsifier in combination.

The amount of the emulsifier used is not particularly limited. However, in consideration of the amount of the copolymer to be obtained and the air entrainment amount, water retention, and workability of the concrete during construction, it is usually 0 with respect to the total amount of the monomer mixture. Used at about 1 to 8 parts by weight.

As the polymerization initiator, any catalyst can be used as long as it is a catalyst used in emulsion polymerization. Typical examples include water-soluble substances such as hydrogen peroxide, ammonium persulfate, potassium persulfate, and sodium persulfate. Inorganic peroxides, organic peroxides such as cumene persulfate hydroperoxide and benzoyl peroxide, azo compounds such as azobisisobutylnitrile, and the like are used as one kind or a mixture of two or more kinds. It is preferable that the usage-amount is 0.1-2 weight part with respect to 100 weight part of a raw material monomer mixture.

Of course, emulsion polymerization may be carried out by redox polymerization using the above initiator together with a metal ion and a reducing agent. The raw material monomer mixture can be added dropwise in a solvent to which the initiator, the emulsifier and the protective colloid are added, in a batch or divided or continuously, from 0 to 100 ° C., The emulsion polymerization is preferably performed at a temperature of 30 to 90 ° C.

The solvent is not particularly limited, but usually water is used. The viscosity of the emulsion obtained as a result of emulsion polymerization is preferably 300 cps or less, and particularly preferably 100 cps or less from the viewpoint of workability in mixing with cement concrete after spraying the emulsion. When the viscosity of the emulsion after emulsion polymerization is high, the viscosity can be adjusted by adding a solvent.

The glass transition temperature of the emulsion polymer is preferably in the range of 0 ° C to 20 ° C. If the glass transition temperature is less than 0 ° C., the plasticity of the emulsion polymer is good, but excessive tackiness occurs, workability in finishing the concrete surface is poor, and the appearance of the finished surface is also poor. On the other hand, it is known that when the glass transition temperature exceeds 20 ° C., the fusing property of the polymer is remarkably lowered. Even if the plasticizer is added to the monomer mixture, the film forming temperature of the emulsion polymer is increased. Even if it is lowered, the finished surface lacks flexibility, which is not preferable.

The solid content (emulsion polymer) content in the emulsion is preferably 20 to 45% by weight. If it is less than 20% by weight, the amount of polymer is relatively small, and it becomes difficult to form a sufficient polymer concrete layer on the concrete surface. On the other hand, if it exceeds 45% by weight, the viscosity becomes high, and the workability of mixing with cement concrete decreases with the iron after spraying the emulsion. For reference, an example of synthesizing an acrylic emulsion will be briefly described in the Examples section.

In order to form a hardened layer (D) of a mixture of cement concrete and acrylic emulsion, the cement concrete is cast, and immediately after the emulsion polymer emulsion is roughly spread on a flat surface with a trowel, rake, etc. It is better to spread while the concrete is semi-hardened. Moreover, there is no restriction | limiting in particular about the application | coating amount, However, From a viewpoint of economical efficiency and workability | operativity, the range of 20-200g in conversion of the solid component of emulsion per 1 m < ² > of construction planes is preferable. More preferably, 50 to 130 g / m ² is applied. The method for spraying the emulsion is not particularly limited, and can be performed using, for example, a sprinkler or a spray gun. In the emulsion, for example, a film-forming auxiliary, an antifoaming agent, an antiseptic, a thickening agent, a water reducing agent, a freezing stabilizer, a water retention agent such as methylcellulose, and the like may be added.

In the construction of the concrete floor according to the present invention, immediately after the cement concrete floor layer (E) is placed on the floor surface and spread roughly on a flat surface with a trowel, a rake, etc. At the time, the emulsion is sprayed, and the uncured cement concrete in the cement concrete layer and the emulsion are surface-finished by rake, iron, etc., so that the emulsion emulsion polymer and cement concrete are uniformly mixed to form polymer concrete. Layer (D) is formed. A predetermined period, for example, 1 to 3 days, or 1 month or more, and further 1 year or more, to apply an acrylic primer for self-leveling material on it, to form a cured layer (C) of the primer, Then, after 1 to 8 hours, a cement-based self-leveling material is applied thereon to form a hardened layer (B) of the cement-based leveling material, and a surface layer (A) is further formed thereon if desired. It is. The construction of the cement-based self-leveling material may be in accordance with a regular method, and is not limited to a specific method.

In addition, according to the construction method which concerns on this invention, after placing a cement concrete floor layer (E) on a floor surface, when forming the hardening layer which consists of a self-leveling material on a polymer concrete layer (D). As demonstrated in the examples described later, an excellent effect that construction is possible even after a considerable period of time, for example, 18 months later is exhibited. In that case, after forming the cured layer (C) layer made of an acrylic primer for a self-leveling material, curing may be performed for a desired period, and then the self-leveling material may be applied thereon. In some cases, the construction method according to the present invention is also used for repairing a concrete floor that is formed by a conventional construction method and has a problem of blistering due to peeling due to insufficient adhesion strength between the concrete surface and the primer. You can also. In that case, all the layers formed on the surface of the cement concrete floor layer (E) are removed, and the surface layer part of the exposed cement concrete floor layer (E) is roughened as necessary. The emulsion is emulsified by newly providing a thin layer of uncured cement concrete on the surface, then spraying the emulsion, and surface-treating the uncured cement concrete of the cement concrete layer and the emulsion with a rake, a trowel or the like. The polymer and cement concrete are uniformly mixed to form a polymer concrete layer (D). The subsequent process may follow the construction method according to the present invention.

According to the construction method of the present invention, it can be used for concrete floors for buildings such as hospitals, schools, station buildings, and other public buildings, convenience stores, condominiums, etc., and in particular, an emulsion having a good affinity with concrete is uniform. Since it is mixed into polymer cement concrete, it has excellent interlayer adhesion strength with the primer material, so that the finished appearance of the concrete surface is also good.

Hereinafter, the present invention will be specifically described with reference to synthesis examples and examples. However, the present invention is not limited to the following synthesis examples and examples.

First, a synthesis example of an acrylic emulsion used to form the (D) layer will be described.

Synthesis Example <(D) Synthesis of Acrylic Emulsion for Layer Formation>
In a stainless steel reaction vessel, 15.0 parts of deionized water, 1 part of sodium dodecylbenzenesulfonate, 1 part of polyoxyethylene nonylphenyl ether, 4.0 parts of Gohsenol GL-05 (polyvinyl alcohol, manufactured by Denki Kagaku Kogyo Co., Ltd.) 4.0 parts of Gohsenol AH-17 (polyvinyl alcohol, manufactured by the same company) were charged, and the contents were sufficiently dissolved while heating and stirring at 75-80 ° C. under a nitrogen stream. Next, 0.5 parts of potassium persulfate was charged, and a mixture of 50 parts of 2-ethylhexyl acrylate, 47 parts of methyl methacrylate and 3 parts of methacrylic acid was dropped and copolymerized over 180 minutes, and cumene was further added. 0.1 part of hydroperoxide was added and held at the same temperature for 60 minutes to complete the polymerization. Next, the mixture was cooled to 30 ° C., and the pH was adjusted to 8.0 using a 6% aqueous sodium hydroxide solution and 15.0 parts of ion exchange water. The obtained emulsion polymer had a non-volatile component of 40%, a viscosity of 1060 cps, and a polymer glass transition temperature of 10 ° C.

Next, examples will be described. First, materials used in the following examples are listed. As the alumina cement, a plain surface area of 3600 cm ² / g and a monocalcium aluminate content of 45% by mass, and as a Portland cement, an early-strength Portland cement with a plain surface area of 4500 cm ² / g, As the gypsum, type II anhydrous gypsum with a plain surface area of 3300 cm ² / g, as the blast furnace slag, with a plain surface area of 4400 cm ² / g, as the silica sand, No. 4 silica sand, which is a commercial product, Lithium carbonate, sodium bicarbonate, and sodium tartrate are commercially available products, the water reducing agent is a commercially available polycarboxylic acid-based water reducing agent, and the antifoaming agent is a commercially available polyether-based antifoaming agent. As an acrylic primer for self-leveling material, U primer Q manufactured by Ube Industries, Ltd. The acrylic-based emulsion, Dainippon Ink and Chemicals Co., Ltd. Co. FF-30, also, the curing material used in Comparative Example was used a master cure 106 commercial wax.

Next, a blending example of the self-leveling material used in the examples of the present invention will be described. Table 1 shows the composition of the self-leveling material used in the following examples.

Example 1 and Comparative Example 1
(1) Slurry preparation of self-leveling material Prepare hydraulic composition by kneading hydraulic components, fine aggregates, admixtures and setting modifiers (total amount 1.5 kg) shown in Table 1 using a chemistor. Further, a predetermined amount of water was added and kneaded for 3 minutes to obtain a slurry. The slurry was prepared under the conditions of a temperature of 20 ° C. and a humidity of 65%.

(2) Slurry physical property flow value of self-leveling material: Measured according to JASS 15M-103. A pipe made of vinyl chloride (internal volume 100 ml) having an inner diameter of 50 mm and a height of 51 mm is placed on a polished glass plate having a thickness of 5 mm, and the mixture is kneaded and then the pipe is pulled up. After the spread has stopped, the diameters in two perpendicular directions are measured, and the average value is taken as the flow value.

The self-leveling property was measured using an SL measuring device shown in FIG. First, as a device having the shape shown in FIG. 1A, a rail having a width (d ₁ ) 30 mm × a height (d ₂ ) 30 mm × a length (d ₃ ) 750 mm and a length 150 mm (d ₄ ) from the tip. ) Where a weir is provided by a weir plate 1 and a predetermined amount of slurry immediately after kneading is filled as shown in FIG. As shown in FIG. 1 (c), the weir plate is pulled up immediately after molding to allow the slurry to flow naturally. At the time when the flow of the slurry stops, the distance from the mark (the installation part of the weir plate) to the shortest part of the slurry flow is measured, and the value (SL value) is defined as L ₀ .

Similarly, as shown in FIG. 1 (d), the weir plate is pulled up 30 minutes after molding, and after the flow of the slurry is stopped, the distance from the gauge point (the installation portion of the weir plate) to the shortest portion of the slurry flow is measured. then, its value (SL value) and L _30. The flow value thus measured was 225 mm, L ₀ was 536 mm, and L ₃₀ was 551 mm.

(3) Adhesive strength with concrete substrate (cured for 1 month) (based on JASS 15M-103)
(I) Materials used: The following materials were used.
As the self-leveling material, one having the composition shown in Table 1 was used. U primer Q (manufactured by Ube Industries) was used as a primer. In Example 1, FF-30 (manufactured by Dainippon Ink & Chemicals, Inc.) was used as an acrylic emulsion (hereinafter sometimes referred to as a curing agent). In Comparative Example 1, Master Cure 106 (manufactured by NMB Co., Ltd.) commercially available as a wax-based curing agent was used in place of the curing agent consisting of an emulsion. The cement concrete floor was formed using ordinary cement consisting of a nominal strength of 21 N / mm ² , a slump of 18 cm, and a maximum aggregate diameter of 20 mm.

(Ii) Formation of cement concrete floor layer (E) and polymer concrete layer (D) First, the formation of cement concrete floor layer (E) and polymer concrete layer (D) will be described. Ready-mixed concrete was placed in a wooden frame having an inner diameter of 300 mm × 300 mm and a height of 200 mm. After placing the ready-mixed concrete, when the cement concrete floor is roughened, acrylic emulsion FF-30 is sprayed at a rate of 300 m1 / m ² , and then pressed with a gold trowel, at a temperature of 20 ° C. and a humidity of 65%. The polymer concrete layer (D) was formed on the cement concrete floor layer (E).

When master cure 106 is used as a curing agent, the master cure 106 is sprayed at a rate of 150 ml / m ² when the cement concrete floor layer (E) is roughened, and then at a rate of 100 m ¹ / m ² even when holding the gold trowel. The polymer concrete layer (D) was formed on the cement concrete floor layer (E) by curing for 1 month under the conditions of a temperature of 20 ° C. and a humidity of 65%.

(Iii) Formation of acrylic primer hardened layer (C) for self-leveling material and cement-based self-leveling material layer (B) Cement of Example 1 and Comparative Example 1 cured for one month after formation of polymer concrete layer (D) 6 times solution of U primer Q to concrete floor (water stock 90g / m ² 450g / m ² is added.) was applied. When the primer becomes transparent, in turn, it was applied 4 times solution (water stock 90g / m ² 270g / m ² is added.). After the primer film formation, the slurry of the self-leveling material was poured so that the thickness when dried was 10 mm. The cement concrete floor structure thus prepared was cured for 14 days under the conditions of a temperature of 20 ° C. and a humidity of 65%.

(Iv) Adhesive strength test As shown in FIG. 2, after making a cut 2 on the surface of the self-leveling material until it reaches the concrete base 7 in a size of 40 × 40 mm, an adhesive is applied to the surface of the self-leveling material layer. Then, the upper tension jig 3 is placed on this and bonded. After standing for 24 hours, the tensile strength at the time when the specimen was broken by applying tension in the vertical direction to the specimen surface was determined as the maximum tensile load T (N), and the bond strength σ was determined. The results of this adhesive strength test are shown in Table 2 below.

The bond strength σ (N / mm ² ) is calculated by the following formula.
σ = T / 1600
(Here, σ is the bond strength (N / mm ² ), and T is the maximum tensile load (N).)

Example 2 and Comparative Example 2
Instead of the cement concrete floor used in Example 1 and Comparative Example 1, a cement concrete floor layer (E) cured for 1 year and 6 months was used. The used cement concrete floor layer (E) is casted with ready-mixed concrete concrete layer (D), then sprayed with 300m1 / m ^{2 of} acrylic emulsion FF-30 at the time of roughening. And then cured under the conditions of a temperature of 20 ° C. and a humidity of 65% for 1 year and 6 months. In Example 2, U primer Q was applied on the polymer concrete layer (D), and in Comparative Example 2, U primer Q was not applied.

In Example 2, in order to confirm the difference depending on the application method of the U primer Q, a test section for one coating and two coatings was provided. In the case of applying twice, first, a 6-fold solution of U primer Q (450 g / m ² of water was added to the stock solution 90 g / m ² ) was applied. Next, when the primer became transparent, a 4-fold solution (270 g / m ² of water was added to the stock solution 90 g / m ² ) was applied. For a single coat was applied 3 times solution (water stock 90g / m ² 180g / m ² is added.). In Example 2, after forming the primer, a slurry of a self-leveling material was poured so as to have a thickness of 10 mm as in Example 1. In Comparative Example 2, the self-leveling material slurry was poured to a thickness of 10 mm in the same manner as in Example 1 with no primer film formed on the polymer concrete layer (D). Each cement concrete floor structure thus obtained was cured for 14 days under the conditions of a temperature of 20 ° C. and a humidity of 65%.

In the same manner as in Example 1 and Comparative Example 1, each sample was subjected to an adhesive strength test. The results are shown in Table 3 below.

In Table 3, the fracture surface in the adhesive strength test is indicated by the following symbols regardless of the examples and comparative examples. In the case of the comparative example, there are no layers corresponding to the D layer and the E layer.
A: Self-leveling material (hereinafter referred to as SL material) Destruction of surface layer B: Destruction of SL material layer C: Destruction of interface between SL material layer and primer layer D: Destruction between primer layers E: Underlayer and primer layer Interfacial fracture: Underlayer destruction

From the results shown in Tables 2 and 3, it is clear that the cement concrete floor structure according to the present invention exhibits excellent adhesive strength. Moreover, regarding the coating method, it was clear from the results shown in Table 3 that a sufficient adhesive strength can be obtained without increasing the number of coatings. Furthermore, it was revealed that sufficient adhesive strength can be obtained even in the cement concrete floor layer (E) cured for 1 year and 6 months.

The cement concrete floor structure according to the present invention has not only excellent adhesive strength itself, but also cement having excellent adhesive strength even if one that has passed 1 year and 6 months has passed since the placement of ready-mixed concrete. The construction method of the concrete floor structure which can construct a concrete floor structure will be provided. Therefore, since there is virtually no problem of blistering due to peeling between the layers constituting the concrete floor structure, a beautiful floor surface can be obtained without unevenness on the floor surface, and the floor surface appearance is excellent. It is possible to provide an optimal structure as a floor of a building such as a public facility such as a hospital, a school, a station, a precision instrument factory, a convenience store, or an apartment.

FIG. 1A to FIG. 1D are diagrams schematically illustrating a self-leveling test method. It is drawing explaining typically the test method of an adhesive strength test.

Explanation of symbols

1 ... sheathing board, 2 ... notch, 3 ... tensile jig, 4 ... self-leveling layer, 5 ... primer-cured layer, 6 ... polymer concrete layer, 7 ... foundation (concrete floor), d 1 _... width of the measurement device, d ₂ ... height of the measuring device, d ₃ ... length of the measuring device, d ₄ ... length of the slurry when a predetermined amount of slurry is filled.

Claims (7)

(E) at least (C) cement concrete floor layer, (D) a cured layer obtained by curing a mixture of uncured cement concrete and acrylic emulsion forming the cement concrete floor layer, (C) for self-leveling material It is comprised from the hardened | cured material layer of an acrylic primer, and the hardened | cured material layer of (B) cement type self-leveling material, The said (B) layer is on the said (C) layer, The said (C) layer is said (D) ) Layer, the (D) layer is a concrete floor structure of a building which is sequentially laminated on the (E) layer.   The concrete floor structure according to claim 1, wherein (A) a surface layer is provided on the (B) layer.   The concrete floor structure according to claim 1 or 2, wherein the building is a building such as a public facility such as a hospital, a school, a station, a precision instrument factory, a convenience store, or an apartment.   4. The concrete floor structure according to claim 1, wherein the acrylic primer for self-leveling material of the cured product layer (C) is an acrylic emulsion.   The said hardened | cured material layer (D) is a hardened | cured material obtained by mixing 1-10 weight% of acryl-type emulsion with cement concrete, The concrete of any one of Claims 1-4 characterized by the above-mentioned. Floor structure. Cement concrete is placed on the floor, and before curing, an acrylic emulsion is sprayed, and a mixture of cement concrete and acrylic emulsion is cured to form a cured product layer composed of the mixture . the polymer concrete layer formed on the layer, and applying a acrylic based primer for self-leveling material on the formed polymer concrete layer, then characterized by applying a cementitious self-leveling material, (E) cement Concrete floor layer, (D) Cured material layer obtained by curing a mixture of uncured cement concrete and acrylic emulsion to form cement concrete floor layer, (C) Curing of acrylic primer for self-leveling material Or (B) a hardened material layer of cement-based self-leveling material The (B) layer is stacked on the (C) layer, the (C) layer is stacked on the (D) layer, and the (D) layer is stacked on the (E) layer. construction method of the concrete floor of a building consisting of Te.   The method for constructing a concrete floor according to claim 6, wherein after the cement-based self-leveling material is applied, a surface layer is further applied on the hardened material layer of the cement-based self-leveling material.

Images