JP6778027B2 - Concrete floor structure and its construction method - Google Patents

Description

The present invention relates to a concrete floor structure obtained by applying a mortar obtained by kneading a hydraulic composition and water as a finishing material on the floor upper surface of the structure and hardening the mortar, and a method thereof.

Outdoor mortar ・ In a concrete floor structure obtained by constructing mortar on the upper surface of a concrete floor, it is necessary to have excellent smoothness, excellent quick-hardening and quick-drying properties, and durability and weather resistance in an outdoor environment. It is believed that there is.

Patent Document 1 discloses a self-fluid hydraulic composition composed of a hydraulic component composed of alumina cement, gypsum, and blast furnace slag, a polymer emulsion, a water reducing agent, and a coagulation adjuster, which can also be used as a floor finishing material. Has been done.

Patent Document 2 describes a hydraulic composition containing a hydraulic component and a resin powder, wherein the resin powder is a vinyl chloride / ethylene / vinyl laurate copolymer, and the hydraulic components include alumina cement and Portland cement. A hydraulic composition containing gypsum and a concrete structure containing the same are disclosed.

Japanese Patent Application Laid-Open No. 10-231165 JP-A-2010-235362

However, while having excellent smoothness and quick-hardening and quick-drying properties, the cured product has excellent surface strength and wear resistance, and also has excellent durability and weather resistance when used in an outdoor environment. Needed to have and needed further improvement.

Therefore, according to the present invention, it is possible to obtain a mortar having excellent fluidity, and to form a cured product having excellent smoothness, quick-hardening and quick-drying properties, and excellent surface strength and abrasion resistance. Furthermore, it is an object of the present invention to provide a concrete floor structure having a hardened surface having good durability and weather resistance in an outdoor environment and a construction method thereof.

As a result of diligent studies to achieve the above object, the present inventors have made hydraulic components consisting of alumina cement, Portland cement and gypsum, blast furnace slag fine powder, fine aggregate, fluidizer, thickener and re-emulsification. By using a hydraulic composition containing cement powder, a mortar having excellent fluidity, a cured product having excellent smoothness and quick-hardening quick-drying property, and excellent surface strength and abrasion resistance, and even better. We have found that a concrete floor structure having a hardened surface having excellent durability and weather resistance can be obtained, and have completed the present invention.

That is, the present invention is a concrete floor structure in which a concrete floor layer, a primer layer and a hardened mortar layer are laminated in this order, and the hardened mortar layer is water-hardened composed of three components of alumina cement, Portland cement and gypsum. A hardened mortar containing components, blast furnace slag fine powder, fine aggregate, fluidizing agent, thickener, re-emulsified resin powder and water, and the proportion of the three components in 100% by mass of the water-hardening component is , Alumina cement 15-80% by mass, Portland cement 5-70% by mass and gypsum 5-45% by mass. The re-emulsified resin powder contains vinyl acetate / acrylic copolymer resin as a main component and is a re-emulsified resin powder. The glass transition temperature Tg is 0 to 20 ° C., the minimum film formation temperature MFT of the re-emulsified resin powder is −5 to 5 ° C., and the blending amount of the re-emulsified resin powder is 100 mass of water-hardening component. The part is 1 to 10 parts by mass, the primer layer is mainly composed of acrylic resin or styrene / acrylic copolymer resin, and the concrete floor structure provides a concrete floor structure to be used outdoors. ..

According to the concrete floor structure of the present invention, a hardened surface having excellent surface strength and wear resistance can be obtained, and a concrete floor having a hardened surface having excellent durability and weather resistance when used in an outdoor environment. The structure can be obtained.

Preferred embodiments [(1) to (5)] of the concrete floor structure of the present invention are shown below. In the present invention, it is more preferable to appropriately combine these aspects.

(1) The hydraulic composition in the concrete floor structure of the present invention preferably further contains one or more selected from the group consisting of a curing accelerator, a setting retarder and an antifoaming agent. As a result, a more excellent quick-hardening and quick-drying property can be obtained, and a cured product having more excellent smoothness can be obtained.

(2) It is preferable that the wear loss thickness of the surface of the hardened body in the concrete floor structure of the present invention at 7 days and 28 days is 0.15 mm or less. As a result, excellent durability that can be used as a finishing material (base finish) can be obtained.

(3) In the concrete floor structure of the present invention, the degree of surface deterioration of the cured product at 7 days of age is preferably 1.2 or less. As a result, it is possible to obtain a mortar cured product having excellent durability as a finishing material (base material finish) even in an outdoor environment.

(4) It is preferable that the base adhesive strength of the cured product in the concrete floor structure of the present invention at 7 days of age is 2 N / mm ² or more. As a result, it is possible to obtain a concrete floor structure that is firmly integrated and has more durability.

(5) The flow value of the mortar in the concrete floor structure of the present invention is preferably 220 to 250 mm. As a result, it is possible to secure excellent workability and obtain a cured mortar having excellent smoothness.

Further, in the present invention, in the above-mentioned construction method of the concrete floor structure, a primer construction step of applying a primer on the upper surface of the concrete floor layer and a primer layer in which the primer is dried and formed into a film to form a primer layer. A forming step, a mortar construction step of constructing a mortar obtained by kneading a water-hard composition and water on the upper surface of a primer layer, and a mortar cured body layer forming step of curing the mortar to form a mortar cured body layer. Provide a construction method having and. The method for constructing a concrete structure of the present invention can obtain a concrete structure having the above characteristics by having a specific step.

According to the present invention, it is possible to form a cured surface having excellent smoothness and quick-hardening and quick-drying property, having excellent surface strength and wear resistance, and having good durability even in an outdoor environment. It is possible to provide a concrete floor structure having a hardened surface having weather resistance and a method for constructing the same.

It is a schematic diagram which shows the concrete structure. It is a schematic diagram which shows the SL measuring instrument. It is a schematic diagram which shows the measuring method of SL value.

An embodiment of the present invention will be described with reference to the drawings, but the following embodiments are examples for explaining the present invention, and the present invention is not intended to be limited to the following contents. In the description, the same reference numerals are used for the same elements or elements having the same function, and duplicate description is omitted.

<Concrete floor structure>
A preferred embodiment of the concrete floor structure of the present invention will be described below. As shown in FIG. 1, the concrete floor structure of the present embodiment is formed by laminating the concrete floor layer 4, the primer layer 3, and the mortar hardened body layer 2 in this order, and is used outdoors.

The hardened body in the concrete floor structure of the present embodiment preferably has a base adhesive strength of 2 N / mm ² or more at a material age of 7 days. It is more preferably ^2.5 N / mm ² or more, further preferably 3.0 N / mm ² or more, and particularly preferably 3.0 N / mm ² or more. As a result, it can be firmly integrated as a concrete floor structure and have excellent durability. The base adhesive strength is measured according to JASS15M-103.

The concrete floor layer 4 in the concrete floor structure of the present embodiment forms the floor of a general concrete structure (building), and the concrete is directly leveled to form the concrete floor layer. In some cases, the upper surface of concrete is leveled with a mortar close to the properties of the concrete to form a concrete floor layer. The concrete floor layer in the present invention refers to these. The compressive strength (nominal strength) of the concrete floor layer is preferably 20 N / mm ² or more, more preferably 30 N / mm ² or more, further preferably 35 N / mm ² or more, and particularly preferably 40 N / mm. ² or more.

The primer layer 3 in the concrete floor structure of the present embodiment is formed by forming a film of a resin emulsion containing an acrylic resin or a styrene / acrylic copolymer resin as a main component. Of these, those containing a styrene / acrylic copolymer resin as a main component are more preferable. Here, the film formation means that the water content in the resin emulsion evaporates and dries to form a resin film. It is preferable that the minimum film-forming temperature MFT of the resin emulsion is 0 ° C. or higher and the glass transition temperature Tg is 0 ° C. or lower.

The resin emulsion used for the primer layer is stored in a state of being dispersed in water, and the solid content concentration thereof is preferably 30 to 70% by mass, more preferably 40 to 60% by mass. If the solid content is too small with respect to water, the cost of transportation and storage will be high, and if the solid content is too large, it will be difficult to disperse uniformly in water, and aggregation and precipitation will easily occur.

The thickness of the primer layer is preferably 5 to 200 μm, more preferably 10 to 150 μm, further preferably 15 to 100 μm, and particularly preferably 20 to 75 μm from the viewpoint of firmly adhering the concrete floor layer 4 and the hardened mortar layer 2. ..

The mortar hardened layer 2 in the concrete floor structure of the present embodiment is a hydraulic component composed of three components of alumina cement, Portland cement and gypsum, blast furnace slag fine powder, fine aggregate, fluidizer, thickener and re-thinker. A hydraulic composition containing emulsified resin powder and mortar containing water are cured to form a layer. More specifically, a cured product obtained by curing the composition and a mortar containing water is formed as a layer. The description of the hydraulic composition, the mortar and the cured product, and the construction method will be described later.

The thickness of the cured mortar layer is preferably 3 to 50 mm, more preferably 5 to 40 mm, further preferably 7 to 30 mm, and particularly preferably 10 to 20 mm from the viewpoint of the finished condition after construction. As a result, the casting work becomes easier, and a hardened surface with high smoothness can be obtained.

<Hydraulic composition>
The hydraulic composition in the concrete floor structure of the present embodiment has excellent fluidity and quick-hardening and quick-drying property, and 100% by mass of the hydraulic component is obtained in order to obtain a cured product having little volume change in the hardening process of mortar. Alumina cement is 15 to 80% by mass, Portland cement is 5 to 70% by mass, and gypsum is 5 to 45% by mass.

The mixing ratio of the water-hard component is preferably 20 to 70% by mass of alumina cement, 10 to 65% by mass of Portland cement and 10 to 40% by mass of gypsum, and more preferably 25 to 60% by mass of alumina cement and 20 by mass of Portland cement. -60% and gypsum 15-35% by mass, more preferably 30-55% by mass of alumina cement, 23-55% of Portland cement and 15-33% by mass of gypsum, particularly preferably 35-50% by mass of alumina cement. , Portland cement 25-55% and gypsum 20-30% by mass.

When the blending ratio of the hydraulic component is in the above preferable range, it is more certain that the material cost is low, the cured product has better fluidity and quick hardness, and the volume change is smaller in the curing process. Become.

As the Portland cement, ordinary Portland cement, early-strength Portland cement, ultra-early-strength Portland cement, moderate heat Portland cement, low heat Portland cement and sulfate-resistant Portland cement can be selected and used. Further, mixed cement such as blast furnace cement, fly ash cement and silica cement can be used as an alternative. From the viewpoint of quick-hardening, it is preferable to use ordinary Portland cement, early-strength Portland cement or ultra-early-strength Portland cement.

The specific surface area of the brain of Portland cement is preferably 3000 to 6000 cm ² / g, more preferably 4000 to 5000 cm ² / g, and further preferably 4200 to 4800 cm ² / g. The brain specific surface area of Portland cement is determined according to JIS R 5201. When the specific surface area of Portland cement is in the above-mentioned preferable range, the balance of strength development and setting time when three components are used is excellent.

Several types of alumina cements having different mineral compositions are known and commercially available, but the main component thereof is monocalcium aluminate (CA), and commercially available products can be used regardless of the type. Of these, it is preferable to use alumina cement having a brain specific surface area of 2000 to 6000 cm ² / g. The brain specific surface area of alumina cement is determined according to JIS R 2521.

Examples of gypsum include dihydrate gypsum, semi-hydrated gypsum, and anhydrous gypsum, and either gypsum produced by-product in flue gas desulfurization, hydrofluoric acid production process, or the like, or naturally produced gypsum can be used. it can. From the viewpoint of fluidity and strength development, it is preferable to use anhydrous gypsum.

The brain specific surface area of gypsum is preferably 2000 to 7000 cm ² / g. When the specific surface area of gypsum is within the above range, it is easy to handle and has high versatility, so that it can be obtained at a low cost. The brain specific surface area of gypsum is determined according to JIS R 5201.

The specific surface area of gypsum is more preferably 2500 to 6000 cm ² / g, further preferably 2750 to 5500 cm ² / g, and particularly preferably 3000 to 5000 cm ² / g. When the specific surface area of gypsum is in the above-mentioned preferable range, it becomes easier to handle and it is highly versatile, so that it can be obtained at a lower cost.

Since the hydraulic component is composed of three components of Portland cement, alumina cement and gypsum, it is possible to obtain a cured product having excellent fluidity and quick-hardening and quick-drying property, and having little volume change in the curing process.

The blast furnace slag fine powder is preferably the blast furnace slag fine powder specified in JIS A 6206 “Blast furnace slag fine powder for concrete”. Also, the Blaine specific surface area of the ground granulated blast furnace slag is preferably 3000 cm ² / g or more, more preferably 3000~8000cm ² / g, more preferably from 3500~6000cm ² / g, particularly preferably 4000 ~ 5000 cm ² / g. The specific surface area of the brain of the blast furnace slag fine powder is determined according to JIS R 5201.

When the brain specific surface area of the blast furnace slag fine powder is in the above preferable range, excellent fluidity, dimensional stability and strength development can be obtained.

The content of the blast furnace slag fine powder is preferably 70 to 140 parts by mass, more preferably 75 to 135 parts by mass, and further preferably 80 to 133 parts by mass with respect to 100 parts by mass of the hydraulic component. It is particularly preferably 85 to 130 parts by mass, and most preferably 90 to 125 parts by mass. When the content of the blast furnace slag fine powder is in the above range, excellent fluidity, dimensional stability and strength development can be obtained.

The fine aggregate preferably does not contain particles having a particle diameter of more than 0.85 mm. As such fine aggregate, sands such as silica sand, river sand, land sand, sea sand, and crushed sand, slag fine aggregate, recycled fine aggregate, and alumina cement clinker can be appropriately selected and used. In particular, as the fine aggregate, sands such as silica sand, river sand, land sand, sea sand and crushed sand, and those selected from alumina cement clinker can be preferably used.

When particles having a particle diameter of more than 0.6 mm are contained in the fine aggregate in a mass fraction of 5% or more, the fluidity of the hydraulic composition tends to decrease. The lower limit of the mass fraction is not particularly limited and may be 0%. In order to obtain excellent fluidity, the mass fraction of particles having a particle size of more than 0.6 mm in the fine aggregate is preferably less than 0 to 5%, more preferably 0 to 3%, and even more preferably. It is 0 to 0.5%, particularly preferably 0.01 to 0.2%.

The particle size of the fine aggregate can be determined according to the JIS A 1102 aggregate sieving test method using several sieves having different nominal dimensions specified in JIS Z 8801-1. Further, in the present specification, the "mass fraction of particles having a particle diameter of more than 0.6 mm" is the mass fraction (%) of particles that remain in the sieve when a sieve having a sieve mesh size of 0.6 mm is used. To say.

Further, the mass fraction (%) remaining in each sieve of the fine aggregate is preferably 0.01 to 5.0% at a sieve mesh opening of 0.425 mm and 30.0 to 90 at a sieve mesh opening of 0.212 mm. 0%, sieving opening 0.15 mm is 60.0-99.0%, more preferably sieving opening 0.425 mm is 0.02-4.0%, sieving opening 0.212 mm is 35. 0 to 85.0%, sieving opening 0.15 mm is 65.0 to 98.0%, more preferably sieving opening 0.425 mm is 0.04 to 3.0%, sieving opening 0. It is 35.0 to 87.5% at 212 mm, 65.0 to 97.0% at a sieve opening of 0.15 mm, and particularly preferably 0.1 to 1.5% at a sieve opening of 0.425 mm. A mesh opening of 0.212 mm is 40.0 to 85.0%, and a sieve mesh of 0.15 mm is 70.0 to 95.0%.

When the mass fraction of the fine aggregate remaining in each sieve is within the above range, better fluidity and better quick-hardening and quick-drying can be obtained.

The coarse grain ratio of the fine aggregate is preferably 0.60 to 1.40, more preferably 0.68 to 1.35, still more preferably 0.72 to 1.28, and particularly preferably. It is 0.74 to 1.25. The water absorption rate of the fine bone agent is preferably 3.00% or less, more preferably 2.95% or less, further preferably 2.90% or less, and particularly preferably 2.80% or less. .. Thereby, better fluidity can be obtained.

In addition, in this specification, "coarse grain ratio" means the coarse grain ratio of the aggregate defined in JIS A 1102. Further, the "water absorption rate" means a value measured according to the measurement method of the water absorption rate (unit:%) of the aggregate specified in JIS A 1109.

The content of the fine aggregate is preferably 160 to 260 parts by mass, more preferably 170 to 250 parts by mass, still more preferably 180 to 240 parts by mass, and particularly, with respect to 100 parts by mass of the hydraulic component. It is preferably 185 to 235 parts by mass, and most preferably 190 to 230 parts by mass. When the content of the fine aggregate is in the above range, excellent fluidity and excellent quick-hardening and quick-drying can be obtained.

The hydraulic composition in the concrete floor structure of the present embodiment has excellent surface strength, abrasion resistance, adhesion to the concrete floor layer, and a cured product having durability and weather resistance in an outdoor environment. A re-emulsified resin powder is contained to obtain a floor structure.

The re-emulsified resin powder contains a vinyl acetate / acrylic copolymer resin as a main component. As a result, the wear resistance is improved, and the resistance to deterioration of the structure due to long-term ultraviolet irradiation is also improved, so that the concrete floor structure can have excellent durability and weather resistance.

The glass transition temperature Tg of the re-emulsified resin powder is 0 to 20 ° C, preferably 5 to 15 ° C, and particularly preferably 8 to 12 ° C. As a result, excellent cured physical properties can be obtained by adding the re-emulsified resin powder such as high bending strength even at room temperature.

The minimum film-forming temperature MFT of the re-emulsified resin powder is −5 to 5 ° C., preferably −2 to 4 ° C., and particularly preferably −1 to 3 ° C. As a result, excellent cured physical properties can be obtained by adding the re-emulsified resin powder such as high bending strength even at room temperature.

The hydraulic composition in the concrete floor structure of the present embodiment is used with a small amount of kneaded water in order to suppress material separation and obtain a high-strength cured product. Therefore, in order to secure high fluidity even if the water / hydraulic component ratio is small, a fluidizing agent having a water reducing effect is contained.

Examples of the fluidizing agent include commercially available fluidizing agents such as formaldehyde condensate of melamine sulfonic acid, casein, casein calcium, polycarboxylic acid type, polyether type and polyether polycarboxylic acid type, which also have a water reducing effect. Can be used regardless of type.

The content of the fluidizing agent can be appropriately contained within a range that does not impair the characteristics, depending on the binder component used, and is preferably 0.005 to 1.0 mass by mass with respect to 100 parts by mass of the water-hard component. Parts, more preferably 0.01 to 0.5 parts by mass, still more preferably 0.025 to 0.4 parts by mass, and particularly preferably 0.1 to 0.3 parts by mass.

If the content of the fluidizing agent is too small, it becomes difficult to obtain a suitable effect (excellent fluidity or good compression strength), and if the content is too large, it becomes difficult to obtain an effect commensurate with the amount added. Not only is it uneconomical, but in some cases the viscosity may increase and the amount of kneading water to obtain the required fluidity may increase.

The hydraulic composition in the concrete floor structure of the present embodiment contains a thickener in order to suppress material separation and obtain good surface texture. As the thickener, a methylcellulose-based thickener is preferable. The methylcellulose-based thickener can be used regardless of the type, but it is particularly preferable to use a hydroxyethyl methylcellulose-based thickener or a hydroxypropylmethylcellulose-based thickener. When the thickener is a methylcellulose-based thickener, it gives a favorable effect on suppressing the separation of hydraulic components and fine aggregates, suppressing the generation of air bubbles, and improving the surface texture of the cured product, and is a hydraulic composition. It is preferable to improve the characteristics of the cured product.

The viscosity of the thickener is preferably 400 to 100,000 mPa · s, more preferably 1000 to 80,000 mPa · s, still more preferably 2000 to 50000 mPa · s, and particularly preferably 3000 to 40,000 mPa · s.

In the present specification, the “viscosity” refers to the viscosity obtained by measuring a 2% by mass aqueous solution of a thickener at 20 ° C. using a B-type viscometer. For the type of rotor and the rotation speed when measuring the viscosity, the combination determined by the viscometer to be used is appropriately selected.

The content of the thickener is preferably 0.02 to 0.80 parts by mass, more preferably 0.04 to 0.70 parts by mass, and further preferably 0.04 to 0.70 parts by mass with respect to 100 parts by mass of the water-hardening component. It is 0.06 to 0.60 parts by mass, and particularly preferably 0.10 to 0.40 parts by mass. When the content of the thickener is in the above range, a better balance with material separation resistance and fluidity can be obtained, and a better surface texture can be obtained.

The hydraulic composition in the concrete floor structure of the present invention preferably further contains one or more selected from the group consisting of a curing accelerator, a setting retarder and an antifoaming agent. As a result, a more excellent quick-hardening and quick-drying property can be obtained, and a cured product having more excellent smoothness can be obtained.

As an example of the setting retarder, organic acids such as oxycarboxylic acids, sugars such as glucose, maltose and dextrin, sodium bicarbonate and sodium phosphate and the like can be used alone or in combination of two or more.

Oxycarboxylic acids include oxycarboxylic acids and salts thereof. Examples of oxycarboxylic acids include aliphatic oxy acids such as citric acid, gluconic acid, tartrate acid, glycolic acid, lactic acid, hydroacrylic acid, α-oxybutyric acid, glyceric acid, tartronic acid and malic acid, salicylic acid and m-oxy. Aromatic oxy acids such as benzoic acid, p-oxybenzoic acid, gallic acid, mandelic acid and tropic acid can be mentioned.

Examples of the salt of oxycarboxylic acid include alkali metal salts (specifically, sodium salt and potassium salt, etc.) and alkaline earth metal salts (specifically, calcium salt, barium salt, magnesium salt, etc.). Yes, sodium salts are more preferred. In particular, sodium tartrate is preferable from the viewpoint of setting delay effect, availability, and price, and it is more preferable to use it in combination with sodium bicarbonate.

The content of the setting retarder is preferably 0.10 to 2.0 parts by mass, more preferably 0.20 to 1.8 parts by mass, still more preferably, with respect to 100 parts by mass of the water-hardening component. It is 0.30 to 1.5 parts by mass, and particularly preferably 0.40 to 1.2 parts by mass. When the content of the setting retarder is in the above-mentioned preferable range, it has more excellent fluidity and a suitable fluidity retention time can be obtained.

As the curing accelerator, a known component that promotes coagulation can be used. For example, a lithium salt, aluminum sulfate, and calcium chloride having a setting promoting effect can be preferably used, and several kinds of these can be used in combination.

Examples of lithium salts include inorganic lithium salts such as lithium carbonate, lithium chloride, lithium sulfate, lithium nitrate and lithium hydroxide, and organic acids such as lithium oxalate, lithium acetate, lithium tartrate, lithium malate and lithium citrate. Lithium salts can be mentioned. In particular, lithium carbonate is preferable from the viewpoints of setting promoting effect, availability and price.

As the curing accelerator, it is preferable to use one having a particle size (average particle size) that does not interfere with the characteristics of the hydraulic composition, and the particle size is preferably 50 μm or less. In particular, when a lithium salt is used, the particle size of the lithium salt is preferably 50 μm or less, more preferably 30 μm or less, still more preferably 20 μm or less, and particularly preferably 10 μm or less. If the particle size of the lithium salt is larger than the above range, the solubility of the lithium salt becomes small, which is not preferable. Especially in the pigment addition system, a large number of fine spots are conspicuous, which may spoil the aesthetic appearance.

The content of the curing accelerator is preferably 0.01 to 2.5 parts by mass, more preferably 0.02 to 1.5 parts by mass, and further preferably 0.02 to 1.5 parts by mass with respect to 100 parts by mass of the water-hardening component. It is 0.05 to 1.0 parts by mass, and particularly preferably 0.1 to 0.5 parts by mass. When the content of the curing accelerator is in the above-mentioned preferable range, it has excellent fluidity, secures a good fluidity retention time, and then can exhibit suitable quick-hardening and quick-drying property.

Examples of the defoaming agent include known ones such as synthetic substances such as silicone-based, alcohol-based and / or polyether-based and / or natural substances derived from plants. Among them, the polyether defoaming agent is preferable from the viewpoint of price and availability. By using a defoaming agent, it can be expected that the defoaming effect of the hydraulic composition will be improved.

The content of the defoaming agent is preferably 0.5 to 5.0 parts by mass, more preferably 0.75 to 4.0 parts by mass, and further preferably 1.0 to 1.0 parts by mass with respect to 100 parts by mass of the water-hardening component. It is preferably contained in an amount of 3.0 parts by mass, particularly preferably 1.25 to 2.0 parts by mass. When the defoaming agent is contained within the above range, the defoaming effect can be easily obtained.

<Mortar>
The mortar in the concrete floor structure of the present embodiment can be prepared (manufactured) by mixing and stirring the above-mentioned hydraulic composition with a predetermined amount of water. Since it has excellent fluidity, it is possible to easily form a horizontal and flat floor surface by applying it to the floor surface of a structure. When preparing the mortar, the fluidity of the mortar can be adjusted by adjusting the blending amount of water.

The mass ratio (W / S) of water (W) to the hydraulic composition (S) of the mortar is preferably 0.18 to 0.28, more preferably 0.19 to 0.26, and even more preferably 0.19 to 0.26. It can be blended and kneaded so as to be in the range of 0.20 to 0.24, particularly preferably 0.21 to 0.23.

There is a flow value (mm) as an index of mortar fluidity. The flow value is a value (unit: mm) measured in accordance with the Architectural Institute of Japan JASS 15M-103 "Quality Standards for Self-Leveling Materials".

The flow value of the mortar obtained by kneading the hydraulic composition and a predetermined amount of water is preferably 220 to 250 mm, more preferably 225 to 245 mm, still more preferably 225 to 240 mm, and particularly preferably. Is 230 to 240 mm. When the flow value is in the above range, it has better fluidity.

There is an SL value (mm) as an index of the flow retention of the mortar. The SL value can be measured using the SL measuring device shown in FIG.

The SL measuring instrument 10 has a gutter shape with internal dimensions of width 30 mm × height 30 mm × length 750 mm, and only one end is an open end. The SL measuring instrument 10 is provided with a filling portion 11 for filling the mortar on the closed end side, and a weir plate 12 adjacent to the filling portion 11 for blocking the filled mortar. The filling portion 11 has a capacity of 30 mm in width × 30 mm in height × 150 mm in length.

FIG. 3 is a cross-sectional view schematically showing a method of measuring the SL value of mortar using the above-mentioned SL measuring device. First, as shown in FIG. 3A, the mortar immediately after kneading is poured so as to fill the filling portion 11. Then, by pulling up the weir 12 for a predetermined time (for example, immediately after pouring (L0), after pouring and standing for 20 minutes (L20), and after pouring and standing for 30 minutes (L30)), (1) of FIG. As shown in b), the poured mortar flows out toward the open end side of the SL measuring instrument 10.

The distance from the reference point 13 to the end point 14 where the mortar flow has stopped is defined as the SL value (mm) of the mortar that has flowed out. The flow retention of the mortar can be evaluated by measuring the SL values (L0, L20, and L30) at this predetermined time.

The SL value (L0) of the mortar is preferably 400 to 600 mm, more preferably 425 to 600 mm, further preferably 450 to 595 mm, and particularly preferably 475 to 590 mm. The SL value (L20) of the mortar is preferably 300 to 595 mm, more preferably 325 to 580 mm, further preferably 350 to 550 mm, and particularly preferably 375 to 530 mm. The SL value (L30) of the mortar is preferably 200 to 575 mm, more preferably 250 to 550 mm, further preferably 300 to 525 mm, and particularly preferably 325 to 500 mm. When the SL value is in the above range, it has excellent fluidity and fluidity retention capable of obtaining an appropriate working time.

<Hardened body>
The hardened body in the concrete floor structure of the present embodiment can be obtained by hardening the above-mentioned mortar. Since the cured product has excellent quick-hardening and quick-drying properties, it is excellent in shortening the construction period and can be suitably used as an outdoor finishing material. The index of quick-hardness can be expressed by the watering time, and the watering time is the time (minutes) required from the preparation (manufacturing) of the mortar to the disappearance of water on the surface of the mortar. The index of quick hardness can also be expressed by the shore hardness, which is the time when 2 hours have passed after the mortar preparation (manufacturing) (material age 2 hours) and the time when 24 hours have passed (material age 24 hours). It is a value measured by a shore hardness meter on the surface of the cured product.

The drainage time of the surface of the mortar prepared using the hydraulic composition is preferably 30 to 120 minutes, more preferably 40 to 110 minutes, still more preferably 45 to 100 minutes, and particularly preferably 50 to 50 to. 90 minutes. When the drainage time is in the above-mentioned preferable range, the cured product has excellent quick-hardening property.

The shore hardness of the mortar surface prepared using the hydraulic composition at a material age of 2 hours is preferably 10 or more, more preferably 20 or more, still more preferably 30 or more, and particularly preferably 40 or more. Is. When the shore hardness is in the above-mentioned preferable range, the cured product has excellent quick-hardness.

The shore hardness of the mortar surface prepared using the hydraulic composition at the age of 24 hours is preferably 70 or more, more preferably 75 or more, still more preferably 78 or more, and particularly preferably 80 or more. Is. When the shore hardness is in the above-mentioned preferable range, the cured product has a strong cured surface.

In addition, the cured product has an excellent surface finish and can be used as a finishing material. There is a cured surface condition as an index of the surface buried surface finish. The cured surface state is the degree of whitening, unevenness, and bubble traces on the surface of the cured product after 24 hours of age, and is determined visually and by touch. If there is no whitening, unevenness, or bubble marks and the surface condition is good, the surface condition is “◯”, and if whitening, unevenness, or bubble marks are generated, the surface is “x”.

The cured surface condition of the cured product is preferably a good surface condition without whitening, unevenness, or bubble marks.

Abrasion loss thickness is an index of wear resistance of the surface of the cured product (the surface of the cured mortar layer). The wear loss thickness (mm) is measured using a Daver type wear tester in accordance with JIS K 7204 "Plastic wear test method using wear wheels", and the wear wheels are GC-150H, load 250 g, 2000 rpm. The wear loss thickness (mm) is obtained by measuring the depth of wear loss with a micron gauge.

The surface wear loss thickness of the cured product at 7 days and 28 days of age is preferably 0.15 mm or less, more preferably 0.12 mm or less, still more preferably 0.11 mm or less, and particularly. It is preferably 0.10 mm or less. By the above-mentioned preferable range, the surface of the finished floor has excellent durability.

As an index of the weather resistance of the cured product, the abrasion loss on the surface of the cured product after irradiating the cured product with a material age of 7 days with ultraviolet rays (illuminance 0.53 kW / m ² ) for 1000 hours (wear on the surface after irradiation with ultraviolet rays). There is a loss). The wear loss thickness after irradiation with ultraviolet rays is preferably 0.18 mm or less, more preferably 0.15 mm or less, still more preferably 0.12 mm or less, and particularly preferably 0.10 mm or less. By the above-mentioned preferable range, the surface of the finished floor has excellent durability and weather resistance.

Further, the ratio of the wear loss thickness of the surface of the cured product at 7 days of age (the degree of deterioration of the surface of the cured product) to the wear loss thickness of the surface after irradiation with ultraviolet rays is preferably 1.2 or less, more preferably. It is 1.15 or less, more preferably 1.10 or less, and particularly preferably 1.05 or less. By the above-mentioned preferable range, it has excellent weather resistance as a cured surface of the finished floor.

Bending strength and compressive strength are indicators of the strength of the cured product. The bending strength and the compressive strength are the strengths obtained in accordance with JASS 15M-103 at the age of 28 days, and should be high values in order to secure the durability as a floor structure.

The compressive strength at the age of 28 days is preferably 40 N / mm ² or more. The bending strength at the age of 28 days is preferably 7 N / mm ² or more. When the strength is in a preferable range, the cured product has excellent durability as a floor on which a heavy object is used.

Base adhesive strength definitive be ages 7 days obtained in compliance with JASS 15M-103 of the cured product is preferably not 1.5 N / mm ² or more, more preferably 2.0 N / mm ² or more, more preferably Is ^2.5 N / mm ² or more, and particularly preferably 3 N / mm ² or more. As a result, a mortar hardened body layer integrated with the concrete floor layer can be formed.

<Construction method>
The construction method of the present invention is the construction method of the concrete floor structure of the present embodiment, in which a primer construction step of applying a primer on the upper surface of the concrete floor layer and a primer layer are formed by drying and forming a film of the primer. A mortar construction step of forming a primer layer to be carried out, a mortar construction step of constructing a mortar obtained by kneading a water-hard composition and water on the upper surface of the primer layer, and a mortar cured product for forming a mortar cured product layer by curing the mortar. It has a layer forming step. A preferred embodiment of the construction method of the present invention will be described below.

The primer construction step is a step of applying (coating) the above-mentioned primer (acrylic resin emulsion or styrene / acrylic copolymer resin emulsion) on the upper surface of the concrete floor layer. The primer can be applied, for example, by appropriately selecting and using a trowel, a roller or a brush. The primer application work may be performed in one treatment, or may be applied in a plurality of times (for example, about 2 to 3 times). The coating amount of the primer, in order to stably obtain a good adhesion strength, the resin solid content contained in the primer, it is preferable to apply the 30 to 120 g / ^{m 2,} coating the 45~90g / ^{m 2} Is more preferable.

The primer layer forming step is a step of drying and forming a film of the applied primer. The drying time after applying the primer can be appropriately set according to the temperature conditions and ventilation conditions, and it is usually preferable to dry for 3 to 8 hours in summer and 5 to 12 hours in winter.

The mortar construction step is a step of constructing (pouring) the above-mentioned mortar obtained by kneading the above-mentioned hydraulic composition and water on the upper surface of the primer layer. The mortar can be cast on a floor surface having a horizontal plane or a floor surface having a gradient of more than 0/1000 and 50/1000 or less. The surface of the cast mortar is made uniform by using a trowel or a dragonfly.

The mortar cured product layer forming step is a step of curing the above-mentioned mortar to form a mortar cured product layer. Since the mortar surface is cured while being homogenized, a mortar cured product layer having more excellent smoothness can be produced.

Although it depends on the temperature and humidity conditions of the construction site, the mortar starts to cure within 40 minutes to 2 hours after the completion of construction (pouring), and the surface hardness increases as the curing progresses, as shown in Fig. 1. As shown, it becomes a mortar hardened body layer.

Although the preferred embodiment of the present invention has been described above, the present invention is not limited to the above embodiment.

Hereinafter, the contents of the present invention will be specifically described with reference to examples. The present invention is not limited to these examples.

[Material used]
The materials used in Examples and Comparative Examples are described below.

<Hydraulic composition>
(1) Hydraulic component, Portland cement [PC] (Early strength Portland cement, manufactured by Ube-Mitsubishi Cement Co., Ltd., brain specific surface area 4480 cm ² / g)
-Alumina cement [AC] (main component: monocalcium aluminate, manufactured by Kerneos, brain specific surface area 3080 cm ² / g)
-Gypsum [GG] (natural anhydrous gypsum, brain specific surface area 4740 cm ² / g)

Table 1 shows the blending ratio of the hydraulic component.

(2) Blast furnace slag fine powder (brain specific surface area 4300 cm ² / g)
(3) Fine aggregate: silica sand (water absorption rate = 2.61%)

Table 2 shows the particle size composition of the fine aggregate (mass fraction staying between each continuous sieve, mass fraction staying in each sieve) and coarse grain ratio.

(4) Re-emulsified resin powder A: Vinyl acetate / Versatic acid vinyl ester / Acrylic acid ester copolymer (MFT = 0 ° C., Tg = 9 ° C.)
B: Acrylic acid ester / methacrylic acid ester copolymer, (MFT = 0 ° C., Tg = 8 ° C.)
C: Styrene / acrylic copolymer (MFT = 0 ° C, Tg = 0 ° C)
D: Vinyl acetate / acrylic copolymer (MFT = 0 ° C., Tg = 10 ° C.)
(5) Fluidizer Polycarboxylic acid-based fluidizer (6) Thickener Hydroxyethyl methyl cellulose-based thickener (viscosity of 2% by mass aqueous solution at 20 ° C.: 28,000 mPa · s, measurement conditions: B-type viscometer, rotation Speed 12 rpm, rotor No. 4)
(7) Defoaming agent Polyether-based defoaming agent (8) Coagulation regulator Coagulation delaying agent: Mixture of sodium tartrate and sodium bicarbonate Curing accelerator: Lithium carbonate (average particle size 3.5 μm)

<Primer>
Resin emulsion (main component: styrene / acrylic copolymer resin, solid content concentration 46% by mass)

<Underground concrete>
As the base plate used for the adhesion strength test, a mortar plate conforming to JIS A 6916 was used.

[Preparation (manufacturing) of hydraulic composition]
The hydraulic composition was prepared in a thermostatic chamber at a temperature of 20 ° C., and the above materials (total amount: 15 kg) were mixed at the blending ratios shown in Table 3. The mixing method is to put the fine aggregate, hydraulic component and blast furnace slag fine powder in this order into the container of the Erich mixer, and then mix the re-emulsified resin powder, fluidizing agent, thickener, defoaming agent and The coagulation adjuster was added and mixed for 4 minutes. The contents of the blast furnace slag fine powder, fine aggregate, re-emulsified resin powder, fluidizing agent, thickener, defoaming agent and coagulation adjuster are parts by mass when the hydraulic component is 100 parts by mass. Represent.

[Preparation of mortar (manufacturing)]
Under the conditions of room temperature of 20 ° C. and humidity of 65%, 330 g of water was added to 1.5 kg of the hydraulic composition shown in Table 3 and kneaded with a stirrer for 3 minutes to obtain a mortar.

The flow value, SL value, drainage time, and shore hardness of each of the obtained mortars were obtained by the methods shown below.

[Flow value]
The flow value was measured in a thermostatic chamber at a temperature of 20 ° C. in accordance with JASS 15M-103 "Architectural Institute of Japan: Quality Standards for Self-Leveling Materials". The flow values of mortar are shown in Table 4.

[SL value]
The SL value of the mortar was measured in a thermostatic chamber at a temperature of 20 ° C. using the SL measuring device shown in FIG. Measurements were carried out immediately after mortar preparation, 20 minutes after standing and 30 minutes after standing (marked as L0, L20, and L30, respectively). The SL values are shown in Table 4.

[Mizuhiki time]
Immediately after the mortar was prepared, the water was poured into a synthetic resin container with internal dimensions of width 130 x length 190 x height 17 mm so that the thickness was 15 mm, and then the surface water on the surface of the mortar was discharged as the condensation started. The time until disappearance (a state in which light reflection was lost and became cloudy) was measured. Table 4 shows the drainage time of the mortar surface.

[Shore hardness]
The shore hardness can be set to any 4 by using a spring type hardness tester type D type (manufactured by Ueshima Seisakusho Co., Ltd.) to measure the hardness of the hardened surface (shore hardness) after 2 hours have passed from the test piece for measuring the drainage time. The surface hardness at each location was measured, and the average value of the readings of the spring type hardness tester type D gauge was used. Table 4 shows the shore hardness of the cured product after 2 hours of age.

[Hardened surface condition]
After 24 hours had passed in a thermostatic chamber at a temperature of 20 ° C., the surface properties (surface whitening, surface unevenness and bubble traces) of the cured product were evaluated visually and by palpation. The evaluation judgment is as follows, and the evaluation results are shown in Table 4.
○… Good, ×… There is a problem

As shown in Table 4, the flow value of Example 1 was 235 mm, which was a particularly preferable range, and the SL value (L30) was 415 mm, which was a particularly preferable range. As a result, it is excellent in fluidity and fluidity retention. The shore hardness was 35 or more in 2 hours (2h) and 80 or more in 24 hours (24h). This makes it excellent in quick hardening. In addition, there was no whitening, unevenness, or bubble marks on the cured surface. As a result, the cured surface condition is also excellent.

The following methods show the wear loss thickness of the cured product obtained by curing each of the obtained mortars and cured at a predetermined age, the wear loss thickness after ultraviolet irradiation, the degree of deterioration, the bending strength, the compressive strength, and the base adhesive strength. Measured in.

[Wear loss thickness]
The wear loss thickness on the surface of the cured product was measured using a Daver type wear tester in accordance with JIS K 7204 "Method for testing plastic wear using a wear wheel". The wear ring was defined as the wear loss thickness (mm) obtained by measuring the depth of wear loss on the surface of the cured product at GC-150H, a load of 250 g, and 2000 rotations with a micron gauge. The test body had a length and width of 110 × 110 mm and a thickness of 10 mm. The test piece was cured in the air in a thermostatic chamber at a temperature of 20 ° C. and an RH of 65%, and the ages of the measurement materials were 7 days and 28 days. The results are shown in Table 5.

[Abrasion loss after UV irradiation]
Using a metering weather meter (manufactured by Gas Testing Machine Co., Ltd., model MV3000), the abrasion loss on the surface of the cured product irradiated with ultraviolet rays at an illuminance of 0.53 kW / m ² for 1000 hours (ultraviolet irradiation) was made in the same manner as above. And measured. Using the test piece cured for 7 days by the same method as the above-mentioned abrasion loss thickness measurement, ultraviolet irradiation was started, and after the irradiation was completed, the abrasion loss was cured for 1 day in a thermostatic chamber at a temperature of 20 ° C. and RH 65%. The thickness was measured under the same conditions as above. The results are shown in Table 5.

[Deterioration]
The ratio of the wear loss thickness of the surface of the cured product of 7 days to the wear loss thickness after UV irradiation (the wear loss thickness of the surface after UV irradiation / the wear loss thickness of the surface of the cured product of 7 days of age) is calculated as the cured product. The degree of deterioration of the surface of. The results are shown in Table 5.

[Bending strength, compression strength]
Bending strength (N / mm ² ) and compressive strength (N / mm ² ) were measured in accordance with JASS 15M-103 "Architectural Institute of Japan: Quality Standards for Self-Leveling Materials". Curing and measurement were carried out in a constant temperature room at a temperature of 20 ° C., and the ages were 7 days and 28 days. The results are shown in Table 6.

[Base adhesive strength]
The primer adhesive strength conforms to JASS 15M-103 "Quality Standards for Self-Leveling Material", and is a styrene / acrylic copolymer resin diluted 3-fold on a mortar substrate with a thickness of 20 mm (mortar plate specified in JIS A 6916). The emulsion was applied in a solid content of 45 g / m ² (the thickness of the primer layer was about 40 μm) and dried for 1 day to form a primer layer, and then each of the above mortars was poured to a thickness of 10 mm. The test piece was cured by curing for 7 days (7 days of age) and cured. Curing and measurement were performed in a homeothermic room at a temperature of 20 ° C. The results are shown in Table 6. The 3-fold diluted solution is diluted by adding 2 water to 1 styrene / acrylic copolymer resin emulsion by mass ratio.

As shown in Table 5, in Example 1, the wear loss thickness at 7 days and 28 days was 0.10 mm or less. As a result, it has excellent durability as the surface of the floor finishing material. Further, the wear loss thickness after irradiation with ultraviolet rays was 0.10 mm or less, and the degree of deterioration of the surface of the cured product was as small as 1.05 or less, showing excellent weather resistance. On the other hand, in Comparative Examples 1 to 3, although the wear loss thickness on the 7th and 28th days of the material was 0.10 mm or less, the wear loss thickness after irradiation with ultraviolet rays increased, the degree of deterioration increased, and the weather resistance was poor. It was enough.

As shown in Table 6, the bending strength at 28 days of age was 7 N / mm ² or more, and the compressive strength was 40 N / mm ² or more. As a result, it has excellent bending and compressive strength as a cured product. Further, in Example 1, the base adhesive strength at the age of 7 days was 2 N / mm ² or more. As a result, it is possible to form a concrete floor structure that is firmly integrated and has more durability.

According to the present invention, it is possible to form a cured surface having excellent smoothness and quick-hardening and quick-drying property, having excellent surface strength and wear resistance, and having good durability even in an outdoor environment. It is possible to provide a concrete floor structure having a hardened surface having weather resistance and a method for constructing the same.

1 ... Concrete floor structure, 2 ... Mortar hardened layer, 3 ... Primer layer, 4 ... Concrete floor layer, 10 ... SL measuring instrument, 11 ... Filling part, 12 ... Weir plate, 13 ... Mark point, 14 ... End point.

Claims (7)

A concrete floor structure in which a concrete floor layer, a primer layer, and a hardened mortar layer are laminated in this order.
The mortar hardened layer contains a hydraulic component composed of three components of alumina cement, Portland cement and gypsum, blast furnace slag fine powder, fine aggregate, fluidizing agent, thickener and re-emulsified resin powder. A hardened mortar containing the composition and water,
The blending ratio of the three components to 100% by mass of the hydraulic component is 15 to 80% by mass of alumina cement, 5 to 70% by mass of Portland cement, and 5 to 45% by mass of gypsum.
The re-emulsified resin powder contains vinyl acetate / acrylic copolymer resin as a main component.
The glass transition temperature Tg of the re-emulsified resin powder is 0 to 20 ° C.
The minimum film-forming temperature MFT of the re-emulsified resin powder is −5 to 5 ° C.
The content of the re-emulsified resin powder is 1 to 10 parts by mass with respect to 100 parts by mass of the hydraulic component.
The primer layer is mainly composed of an acrylic resin or a styrene / acrylic copolymer resin.
The concrete floor structure is used outdoors.
Concrete floor structure. The hydraulic composition further comprises one or more selected from the group consisting of a curing accelerator, a setting retarder and an antifoaming agent.
The concrete floor structure according to claim 1. The surface wear loss thickness of the cured product at 7 days and 28 days of age is 0.15 mm or less.
The concrete floor structure according to claim 1 or 2. The degree of surface deterioration of the cured product at 7 days of age is 1.2 or less.
The concrete floor structure according to any one of claims 1 to 3. The base adhesive strength of the cured product at 7 days of age is 2 N / mm ² or more.
The concrete floor structure according to any one of claims 1 to 4. The flow value of the mortar is 220 to 250 mm.
The concrete floor structure according to any one of claims 1 to 5. The method for constructing a concrete floor structure according to any one of claims 1 to 6.
A primer construction step of applying a primer on the upper surface of a concrete floor layer, a primer layer forming step of drying and forming a primer to form a primer layer, and a kneading of a water-hard composition and water on the upper surface of the primer layer. It has a mortar construction step of constructing the obtained mortar and a mortar cured body layer forming step of curing the mortar to form a mortar cured body layer.
Construction method.