JP2013108339A - Method for constructing concrete floor structure, and concrete floor structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for constructing a concrete floor structure suitable for constructing drainage slope through the use of self-levelling material having excellent balance among flowability, fast curing, and quick drying; and a floor structure produced by the method.SOLUTION: A method for constructing a self-levelling material slurry includes a step of placing a self-levelling material slurry prepared by kneading a self-levelling material and water on the top face of a building floor so as to form a cured slurry layer. The self-levelling material includes a hydraulic setting component formed of 20 to 80 mass% of alumina cement, 5 to 70 mass% of Portland cement, and 5 to 45 mass% of gypsum, a fluidizing agent, and a thickener. The thickener contains a cellulose thickener and bentonite having an average particle diameter of 30 μm or less. The contents of the cellulose thickener and the bentonite relative to 100 mass parts of the hydraulic setting component satisfy a specific relation.

Description

  The present invention relates to a concrete floor structure construction method and a concrete floor structure obtained by the method.

  In buildings such as machine factories, food factories, warehouses, distribution centers, department stores and hospitals, various resin-based coating materials and various polymer cement-based coating materials are often used as finishing materials for new and improved concrete floor surfaces. . When these coating floor materials are used for finishing the concrete floor surface, the effect of improving the wear resistance, chemical resistance, corrosion resistance and antistatic property of the floor surface can be obtained.

  As a construction method of the concrete floor surface in the case of using a coating floor material as a finishing material, there are a concrete direct pressing method, a joint construction method in which a slurry of mortars and a self-leveling material is applied on the concrete floor surface, and the like.

  When the finish of the new concrete floor surface is poor, for example, unevenness of the floor surface due to rain before the concrete floor hardens (rain hitting surface) or poor horizontality due to insufficient finish of the concrete floor surface (non-land surface) In the case of the surface of the modified concrete floor, the surface of the floor with the coated flooring is improved after applying a slurry of mortars or self-leveling material on the concrete floor surface using the joint method to improve the floor surface finish. Finishing and forming a concrete floor structure. In addition, the base material for the flooring material used in the joining method must have good surface horizontality, sufficient surface hardness, strength, dimensional stability, and good adhesion to the flooring material. .

  As the mortar, a resin mortar is often used, and an epoxy resin, a urethane resin, or the like is used as the resin, but it is as expensive as a coating floor material. In addition, there are some which have high viscosity and poor workability for finishing the surface. General repair cement mortar is inexpensive but has low adhesion and strength properties to the flooring material, and it is difficult to ensure horizontality by dredging.

  Self-leveling materials can be broadly classified into gypsum and cement. The former is highly likely to expand due to moisture such as moisture from the base while the surface is sealed with a coated flooring material, and the latter has low dimensional stability (changes in shrinkage and expansion) when only Portland cement is used. ), And there is a high possibility that adhesion to the flooring material will decrease. When alumina cement is included in the cement system, it is possible to finish a surface with good levelness by lightly leveling the surface with a ridge or a dragonfly in a slurry state, and it has excellent dimensional stability after curing and moisture such as moisture. In addition, it is cheaper than resin mortar.

  Patent Document 1 discloses a construction method of a concrete floor structure including a step of using a slurry of a self-leveling material containing alumina cement and resin powder for a building, and providing a hardened layer of the self-leveling material slurry on the upper surface of the concrete floor. It is disclosed.

  In Patent Document 2, a leveling material including a hydraulic component made of alumina cement, Portland cement, and gypsum and acrylic copolymer re-emulsified resin powder is used, and slurry is placed on the upper surface of an outdoor cocrete floor. A method for constructing a concrete floor structure having a curing step is disclosed.

JP 2009-257062 A JP 2008-248558 A

  However, a conventional construction method using a self-leveling material is not sufficiently suitable for water gradient construction because the balance between the fluidity of the self-leveling material and the fast curing and quick drying properties is not sufficient.

  The present invention provides a concrete floor structure construction method suitable for water gradient construction, and a concrete floor structure obtained by the method, using a self-leveling material having an excellent balance between fluidity, quick hardening and quick drying. For the purpose.

  As a result of detailed studies to solve the above problems, the present inventors have found that the above problems can be solved by using a slurry of a specific self-leveling material, and have completed the present invention.

That is, the present invention is a method for constructing a concrete floor structure having a step of placing a self-leveling material slurry prepared by kneading a self-leveling material and water on a floor surface of a building to form a slurry hardened body layer. The self-leveling material includes 20 to 80% by mass of alumina cement, 5 to 70% by mass of Portland cement and 5 to 45% by mass of gypsum, a fluidizing agent, and a thickening agent. The thickener contains a cellulose-based thickener and bentonite having an average particle size of 30 μm or less, and the content of the cellulose-based thickener and the content of bentonite with respect to 100 parts by mass of the hydraulic component is represented by the following formula (1). A construction method that satisfies the relationship expressed by
Y = -21.2X + t (1)
[Wherein, X represents the content (parts by mass) of the cellulosic thickener, 0.06 <X <0.14, Y represents the content (parts by mass) of bentonite, and t represents the coefficient. It is 2.81 ≦ t ≦ 3.86. ]

  The construction method of the present invention is a water gradient construction method because a self-leveling material containing a hydraulic component having a predetermined composition, a fluidizing agent and the above-mentioned specific thickening agent is excellent in balance between fluidity, fast curing and quick drying. It becomes suitable for. The present inventors presume that this factor is due to the balance between the plastic viscosity and the yield value in the viscosity characteristics of the self-leveling material.

  In the construction method of the present invention, the self-leveling material further contains a re-emulsified resin powder, thereby preventing generation of surface cracks and dry-out due to surface drying during curing of the slurry layer, and generation of breathing water due to material separation. In addition, the finish of the surface of the slurry cured body layer can be improved. Moreover, the elasticity of the slurry cured body layer can be increased and the occurrence of cracks can be prevented.

  In the construction method of the present invention, the re-emulsified resin powder preferably contains a vinyl acetate-veova-acrylic copolymer and / or an acrylic-methacrylic copolymer. By using the copolymer as a re-emulsifying resin powder, a more uniform cured surface can be obtained when the self-leveling material slurry is cured.

  In the construction method of the present invention, it is preferable that the self-leveling material further includes at least one component selected from inorganic powder, fine aggregate, a setting modifier and an antifoaming agent. By further containing at least one of the above components, the workability of the self-leveling material slurry can be further improved, and a cured slurry layer having excellent strength characteristics can be formed.

  Moreover, in the construction method of this invention, before forming a slurry hardening body layer, it may further have the process of apply | coating the primer for self-leveling materials on the floor upper surface of a building, and forming a 1st primer film layer. it can. By forming the first primer film layer between the floor surface of the building and the hardened slurry layer, the floor surface of the building and the hardened slurry layer can be more firmly bonded.

  Furthermore, in the construction method of the present invention, a step of applying a primer for a coating floor material on the upper surface of the slurry cured body layer to form a second primer coating layer, and a coating on the upper surface of the second primer coating layer A step of applying a floor base coat and forming a coated floor base coat layer. By forming the second primer film layer, it is possible to obtain effects such as improvement in adhesion to the base of the flooring material, prevention of suction into the base, and prevention of pinholes in the flooring material. Moreover, the main functions such as durability, mechanical strength, and elasticity of the coating floor material can be improved by forming the coating floor material base coat layer.

  The present invention also provides a concrete floor structure obtained by the above construction method. By the construction method using the above-mentioned self-leveling material which is excellent in the balance between fluidity, fast curing and quick drying, a concrete floor structure having a suitable gradient is obtained.

  ADVANTAGE OF THE INVENTION According to this invention, the construction method of a concrete floor structure suitable for water gradient construction can be provided using the self-leveling material excellent in the balance of fluidity | liquidity, quick-hardness, and quick-drying. And the concrete floor structure in which the suitable gradient was formed can be provided by using the construction method of this invention.

It is sectional drawing which shows typically the construction procedure in the construction method of the concrete floor structure which concerns on this embodiment. It is a perspective view of SL measuring device used for self-leveling property evaluation. (A) It is sectional drawing which shows the state with which the SL measuring device was filled with the slurry, and (b) the state which pulled up the weir board and the slurry flowed. It is a figure which shows the particle size distribution of bentonite. It is a figure which shows the relationship between content of a cellulose thickener, and content of bentonite. It is sectional drawing which shows typically the gradient of a concrete floor and a slurry hardening body layer in the construction test in an external environment.

<Concrete floor structure construction method>
The concrete floor structure construction method of the present invention includes a step of placing a self-leveling material slurry prepared by kneading a self-leveling material and water on the floor of a building to form a hardened slurry layer.

  The construction method includes a step of applying a primer for a self-leveling material on a concrete floor upper surface to provide a first primer film layer, and kneading a self-leveling material and water on the upper surface of the first primer film layer. A step of placing the prepared slurry to provide a slurry cured body layer; a step of applying a primer for a coating floor material on the upper surface of the slurry cured body layer to provide a second primer coating layer; It is preferable to provide a step of applying a coating floor base coat on the upper surface of the primer coating layer to provide a cured body layer (coating floor base coat layer) of the coating floor base coat.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings as appropriate.

  FIG. 1 is a cross-sectional view schematically showing a construction procedure in a construction method for a concrete floor structure according to the present embodiment.

  As shown to Fig.1 (a), the floor upper surface 2 of the concrete floor 1 inclines gently, and is provided with the uneven part. The composition, thickness, installation location (indoor or outdoor) and the like of the concrete floor 1 are not particularly limited, and may be a concrete floor of a new building or a concrete floor of an existing building.

  For concrete floors in new buildings, for example, after placing and compacting ready-mixed concrete to give a certain level of flatness, the surface of the concrete surface is smoothed using a plasterer or the like when water is drawn on the concrete surface. It is obtained by leveling rough irregularities and curing and hardening the concrete. For this reason, the surface of the entire hardened concrete floor tends to be in a state of being complicated with various small irregularities and subtle inclinations.

  For example, when renovating the concrete floor of an existing building, remove the painted flooring material and pasted flooring material that were originally constructed, and then grind the concrete floor surface to smooth out rough irregularities. However, also in this case, the surface of the entire concrete floor tends to be in a state of being complicated with various small irregularities and subtle inclinations.

  In the construction method of the present embodiment, first, as shown in FIG. 1 (b), it is preferable to include a step of forming a first primer film layer 3 by applying a primer for a self-leveling material to the floor surface 2. . By providing the first primer film layer 3 on the floor upper surface 2, it becomes possible to more firmly bond the floor upper surface 2 and the self-leveling material slurry layer 4a (cured slurry layer 4b). Further, when the self-leveling material slurry is placed, it becomes easy to prevent moisture in the slurry from penetrating into the concrete floor 1.

  As a primer for a self-leveling material, a commercially available primer mainly composed of an acrylic-styrene copolymer resin or an ethylene vinyl acetate copolymer can be used, and in particular, a primer mainly composed of an acrylic-styrene copolymer resin is preferably used. can do.

The primer for the self-leveling material can be applied by appropriately selecting, for example, a trowel, a roller or a brush. The primer may be applied by a single treatment or may be applied multiple times (for example, about 2 to 3 times). The primer coating amount is preferably 30 to 120 g / m ^2, and preferably 45 to 90 g / m ² in order to stably obtain good adhesive strength as the resin solid content contained in the primer. Is more preferable.

  The thickness of the first primer film layer 3 is preferably 5 to 200 μm, more preferably 10 to 100 μm, from the viewpoint of firmly bonding the floor upper surface 2 and the self-leveling material slurry layer 4a (self-leveling material slurry cured body layer 4b). It is preferably 15 to 75 μm, more preferably 20 to 50 μm.

  The drying time after the primer application can be appropriately determined according to temperature conditions and ventilation conditions, and is preferably 3 to 8 hours in summer and 5 to 12 hours in winter.

  Next, as shown in FIG. 1 (c), a slurry 4 a prepared by kneading a self-leveling material and water, which will be described later, is placed on the upper surface of the first primer coating layer 3.

  The slurry 4a can be placed on a floor surface having a horizontal surface or a floor surface having a gradient of more than 0/1000 and not more than 50/1000.

  Next, as shown in FIG. 1 (d), the placed slurry 4 a is homogenized using a ridge 5. Thereby, it can construct so that the surface of the self-leveling material slurry layer 4a may have a fixed gradient.

  Although the self-leveling material slurry layer 4a depends on the temperature and humidity conditions at the construction site, curing begins for 40 minutes to 3 hours after the construction is completed, and the surface hardness increases as the curing progresses. As shown to 1 (e), it becomes the slurry hardening body layer 4b. The water content on the surface of the cured slurry layer 4b tends to decrease.

  The self-leveling material slurry layer 4a is preferably cured for 1.75 to 12 hours, more preferably 1.8 to 11 hours, still more preferably 1.85 to 10 hours, and particularly preferably 1.9 to 6 hours. It is preferable to make it. Before 1.75 hours, the surface hardness of the slurry cured body layer sufficient to perform the operation for constructing the coating floor material may not be expressed. In addition, after the self-leveling material slurry has been placed and applied, if within 12 hours, moisture detachment from the surface of the slurry cured body layer has not progressed, so that the inside of the slurry cured body layer is sufficiently hydrated. Moisture required for the water is sufficiently secured, and high strength characteristics can be imparted.

  The Shore hardness of the surface of the slurry cured body layer after 2 hours formed by casting the slurry and finishing the surface of the slurry is preferably 40 or more, more preferably 42 or more, and still more preferably 44 or more. And particularly preferably 46 or more. Further, the Shore hardness of the surface of the cured slurry layer after 24 hours is preferably 64 or more, more preferably 66 or more, still more preferably 68 or more, and particularly preferably 70 or more. The upper limit of the Shore hardness is not particularly limited, but is about 100 which is the measurement limit value of the Shore hardness meter. If the shore hardness of the surface of the slurry hardened body layer is in the above range, after the slurry construction (placement and finishing) is completed, the hardened structure proceeds quickly to form a floor structure with a gradient in a short time. It becomes easy.

  The surface of the slurry cured body layer preferably has a gradient of more than 0/1000 and not more than 50/1000, more preferably more than 0/1000 and not more than 45/1000, more than 0/1000. More preferably, it has a gradient of 40/1000 or less. Thereby, favorable drainage property can be provided to the formed slurry cured body layer. In this embodiment, for example, having a gradient of 50/1000 means that the height of the start point (one side) is 0 mm and the height of the end point (opposite side) is 50 mm in a horizontal line of 1000 mm. It means having

  As shown in FIG. 1 (e), a primer for a coating floor material is applied to the upper surface of the slurry cured body layer 4 b, a second primer coating layer 6 is provided, and a coating floor is applied to the upper surface of the second primer coating layer 6. After the step of applying the base coat for the material and providing the base coat layer 7, the top coat for the flooring material can be applied to the upper surface of the base coat layer 7 to provide the top coat layer 8.

  The coating floor material is preferably composed of a primer layer, a base coat layer, and a top coat layer, but may be composed of a primer layer and a base coat layer depending on the purpose and application. Further, after providing the primer layer, a plurality of base coat layers and top coat layers can be provided.

  As a kind of coating floor material, it can select from an organic type coating floor material or an inorganic type coating floor material suitably according to the characteristic requested | required, and can be used.

  The second primer film layer 6 is preferably provided from the viewpoints of improving adhesion to the base of the flooring material, preventing suction into the base, and preventing pinholes in the flooring material.

  Primers for organic coating floor materials include solvent-based epoxy resin-based, solvent-free epoxy resin-based, water-based epoxy resin-based, water-based epoxy resin-based and cement mixture, solvent-based urethane resin-based, solvent-based urethane resin-based And cement mixing, solvent-free urethane resin, moisture-curing urethane resin, moisture-curing urethane resin and cement, methacrylic resin, solvent-based acrylic resin, water-based acrylic resin, etc. it can. Moreover, the primer for coating floor materials containing fillers, such as an organic pigment, an inorganic pigment, or a talc, a calcium carbonate, powdery silica, can be used depending on a use.

  Moreover, as a primer for inorganic coating floor materials, a water-type ethylene vinyl acetate resin system, a water-type acrylic resin system, a solvent-type epoxy resin system, a solvent-type acrylic resin system, etc. can be used. The primer for the coating floor material can be used by appropriately selecting a brush or a roller in accordance with the installation manual of each coating floor material manufacturer.

  The coating floor base coat layer 7 is preferably provided from the viewpoint of imparting main functions such as durability, mechanical strength, and elasticity of the coating floor.

  Base coats for organic coating floor materials include solvent-based epoxy resin-based, solvent-free epoxy resin-based, water-based epoxy resin-based, solvent-based urethane resin-based, solvent-based urethane resin-based, moisture-curing urethane resin-based, methacrylic resin System, solvent-type acrylic resin system, water-based acrylic resin system, polyester resin system, vinyl ester resin system and the like can be used. Depending on the use, one or more base coats selected from organic pigments, inorganic pigments or fillers such as talc, calcium carbonate, and powdered silica, and organic base coats containing fine aggregates may be used. It selects suitably, and can construct and use 1 layer or 2 layers or more.

  As base coats for inorganic coating floor materials, Portland cement, white Portland cement, super-hard cement, special fast-curing cement and cementitious combination of two or more of cement, alumina vinyl acetate, styrene butadiene A base coat for a coating floor material composed of one or a combination of two or more synthetic resin emulsions such as rubber, chloroprene rubber, acrylic and epoxy can be used. In addition, one or two or more base coats selected from base coats for inorganic coating floor materials containing fillers such as organic pigments, inorganic pigments, or talc, calcium carbonate, powdered silica, etc., are selected as appropriate, One layer or two or more layers can be applied and used. The construction of the base coat for the coating floor material can be performed by appropriately selecting a trowel, a roller or a brush according to the construction manual of each coating floor material manufacturer.

  The coating floor material top coat layer 8 is preferably provided from the viewpoint of protecting the base coat layer 7 such as weather resistance, stain resistance, anti-slip property, or matte finish and imparting various functions. Top coats for organic or inorganic coating floor materials include solvent-based epoxy resins, solvent-free epoxy resins, water-based epoxy resins, solvent-type urethane resins, solvent-type urethane resins, and moisture-curing urethanes One or two or more layers of a top coat selected from resin, methacrylic resin, solvent-based acrylic resin, water-based acrylic resin, polyester resin, vinyl ester resin, etc. are selected as appropriate. It can be used after construction. The construction of the top coat for the coating floor material can be used by appropriately selecting a trowel, a roller, a brush or the like in accordance with the construction manual of each coating floor material manufacturer.

  Concrete comprising the floor 1, the first primer coating layer 3, the slurry cured body layer 4b, the second primer coating layer 6, the coated floor base coat layer 7 and the painted floor top coat layer 8 by the construction method of the present embodiment. The floor structure 9 can be obtained. The concrete floor structure 9 is a floor structure in which a gradient is suitably formed because the self-leveling material has an excellent balance between fluidity, fast curing, and quick drying.

<Self-leveling material>
The self-leveling material according to the present embodiment includes a hydraulic component composed of alumina cement 20 to 80% by mass, Portland cement 5 to 70% by mass and gypsum 5 to 45% by mass, a fluidizing agent, and a thickener. The thickener contains a cellulosic thickener and bentonite having an average particle size of 30 μm or less, and the content of the cellulose thickener and the content of bentonite with respect to 100 parts by mass of the hydraulic component satisfy a specific relationship. It is characterized by that.

  As alumina cements used for hydraulic components, several types having different mineral compositions are known and commercially available, but the main component is monocalcium aluminate (CA). Can be used.

  As the Portland cement used for the hydraulic component, it can be selected from ordinary Portland cement, early-strength Portland cement, ultra-early-strength Portland cement, moderately hot Portland cement, low heat Portland cement and sulfate resistant Portland cement. Moreover, mixed cements such as blast furnace cement, fly ash cement, silica cement and the like can be used as an alternative. From the viewpoint of quick setting, it is preferable to use ordinary Portland cement, early-strength Portland cement, or ultra-early-strength Portland cement.

  Examples of the gypsum used for the hydraulic component include dihydrate gypsum, hemihydrate gypsum, and anhydrous gypsum. Gypsum by-produced in flue gas desulfurization and hydrofluoric acid manufacturing processes, or gypsum produced in nature Either can be used. From the viewpoint of workability (high fluidity, long pot life), it is preferable to use anhydrous gypsum.

  The hydraulic component needs to contain alumina cement, Portland cement, and gypsum in the above range when the mass is 100% by mass. This makes it easy to obtain a slurry cured body layer that is low in material cost, has self-fluidity and rapid curing, and has a small volume change during curing.

  The blending ratio of the hydraulic component is preferably 25 to 75% by mass of alumina cement, 10 to 65% by mass of Portland cement and 10 to 40% by mass of gypsum, more preferably 30 to 70% by mass of alumina cement, 15 to 15% of Portland cement. 60% by mass and 15 to 35% by mass of gypsum, particularly preferably 35 to 65% by mass of alumina cement, 20 to 55% by mass of Portland cement and 20 to 30% by mass of gypsum.

  As the fluidizing agent, commercially available fluidizing agents such as formaldehyde condensate of melamine sulfonic acid, casein, casein calcium, polycarboxylic acid, polyether and polyether polycarboxylic acid, which have a water reducing effect, are included. It can be used regardless of the type, and it is particularly preferable to use a commercially available fluidizing agent such as polyether-based and polyether polycarboxylic acid.

  The fluidizing agent can be appropriately added in a range that does not impair the characteristics, depending on the hydraulic component used, and is preferably 0.01 to 2.0 parts by mass, more preferably 100 parts by mass with respect to the hydraulic component. 0.05 to 1.0 part by mass, more preferably 0.07 to 0.7 part by mass, and particularly preferably 0.1 to 0.5 part by mass. When the addition amount of the fluidizing agent is less than 0.01 parts by mass, excellent fluidity as a slurry and high strength as a slurry cured body layer tend not to be expressed. Moreover, even if the addition amount is more than 2.0 parts by mass, it tends to be difficult to obtain an effect commensurate with the addition amount, which is not only uneconomical, but also increases the viscosity in some cases, which is necessary. In some cases, the amount of water for kneading to obtain the fluidity increases and the strength properties deteriorate.

  As a thickener, a cellulosic thickener and bentonite are included. The cellulose-based thickener can be used regardless of its type, but it is particularly preferable to use hydroxyethyl methylcellulose. The viscosity of the cellulosic thickener is preferably 20000 to 40000 mPa · s, more preferably 22,500 to 37500 mPa · s, further preferably 25000 to 35000 mPa · s, and 27500 to 32500 mPa · s. It is particularly preferred. The viscosity of the cellulose-based thickener can be obtained by measuring an aqueous solution (20 ° C.) containing 2% by mass of the thickener using a B-type viscometer. When the viscosity of the cellulosic thickener is within the above range, the slurry hardened material layer has a favorable effect for suppressing the separation of hydraulic components and fine aggregates, suppressing the generation of bubbles, and improving the surface of the slurry hardened material layer. It is possible to improve the characteristics. Further, as a thickener other than the cellulose-based thickener, a thickener selected from a protein-based starch, a starch-based processed starch, a latex, a water-soluble polymer, and the like can be used in combination.

  Bentonite used as a thickener is mainly composed of montmorillonite, a clay mineral, silicate minerals such as quartz, α-cristobalite and opal as minor components, silicate minerals such as feldspar, mica and zeolite, It is a weak alkaline claystone containing carbonate minerals and sulfate minerals such as sites, dolomite and dipsum, and sulfide minerals such as pyrite. The bentonite according to the present embodiment has an average particle size of 30 μm or less, preferably 28 μm or less, more preferably 26 μm or less, and particularly preferably 25 μm or less. When bentonite has an average particle size of 30 μm or less, the yield value in the viscosity characteristics of the slurry is improved, and a gradient can be suitably formed. The lower limit of the average particle size of bentonite is not particularly limited, but is preferably 10 μm or more, and more preferably 15 μm or more.

In the self-leveling material according to the present embodiment, the content X (mass part) of the cellulose-based thickener with respect to 100 parts by mass of the hydraulic component and the content of bentonite having an average particle diameter of 30 μm or less with respect to 100 parts by mass of the hydraulic component. Y (part by mass) satisfies the relationship represented by the following formula (1). Here, X is more than 0.06 parts by mass and less than 0.14 parts by mass, t is a coefficient, and 2.81 ≦ t ≦ 3.86.
Y = -21.2X + t (1)

Satisfying the relationship of the above formula (1) means that the above X and Y are surrounded by straight lines represented by the following formulas (2) to (5) (however, on the formula (4) and the formula (5)) Is inside).
Y = -21.2X + 2.81 (2)
Y = -21.2X + 3.86 (3)
X = 0.06 (4)
X = 0.14 (5)

  If the content of the cellulosic thickener and the content of bentonite having an average particle size of 30 μm or less are within the above range, the balance between the plastic viscosity and the yield value will be compatible, and the fluidity, fast curing, and quick drying will be achieved. Self-leveling material with excellent balance. Such a self-leveling material is suitably used in the present construction method.

In the above formula (1), X is preferably more than 0.07 and less than 0.13. That is, the above-mentioned X and Y are the ranges surrounded by the straight lines represented by the above formulas (2) and (3) and the following formulas (6) and (7) (however, above and in the formula (6) (7) Except for the above), it becomes an excellent self-leveling material due to the balance of fluidity, fast curing and quick drying. Such a self-leveling material can be suitably used by this construction method.
X = 0.07 (6)
X = 0.13 (7)

  The self-leveling material in the construction method of the present embodiment can further contain re-emulsifying resin powder. By including the re-emulsified resin powder, it prevents the generation of surface cracks and dryout due to drying of the surface of the cured slurry layer when applying a slurry of the leveling material, or the generation of breathing water due to material separation. It becomes easy to improve the finish of the surface of the cured body layer. Moreover, it becomes easy to raise the elasticity of a slurry hardening body layer and to prevent generation | occurrence | production of a crack.

  The self-leveling material can be used as a premix powder, but by including a re-emulsified resin powder, it becomes easy to strictly control the blending ratio of the components, and the components are premixed. Easier to supply to the site.

  The type of the re-emulsified resin powder is not particularly limited, and those produced by a known production method can be used, and those obtained by attaching an anti-blocking agent mainly to the surface of the re-emulsified resin powder. Can be used. It is also preferable to use a re-emulsified resin powder obtained by removing the solvent from the aqueous polymer dispersion by a method such as spraying or freeze drying.

  The re-emulsifying resin powder is preferably a re-emulsifying resin powder containing a vinyl acetate-veova-acrylic copolymer and / or a re-emulsifying resin powder containing an acrylic-methacrylic copolymer. Thereby, a more uniform cured surface can be obtained when the slurry is cured.

  The content of the re-emulsified resin powder is preferably 1 to 25 parts by mass, more preferably 2 to 20 parts by mass, and 3 to 15 parts by mass with respect to 100 parts by mass of the hydraulic component. It is still more preferable and it is especially preferable that it is 4-10 mass parts.

  If the content ratio of the re-emulsified resin powder is less than 1 part by mass, it tends to be difficult to prevent the occurrence of surface cracks and dryout due to the drying of the surface of the cured slurry layer described above, and more than 25 parts by mass. In this case, the viscosity of the slurry obtained by adding water is increased, the workability is lowered, and the compressive strength of the slurry cured body layer tends to be lowered.

  The self-leveling material in the construction method of the present embodiment can further contain at least one component selected from inorganic powder, fine aggregate, a setting modifier and an antifoaming agent.

  As the inorganic powder, blast furnace slag fine powder specified by JIS A 6206 “Blast furnace slag fine powder for concrete”, siliceous mixed material specified by JIS R 5212 “silica cement”, JIS A 6207 “silica fume for concrete” Silica fume specified in JIS A 6201 “Fly ash for concrete”, fine limestone powder, and the like can be used. Here, the limestone fine powder can be suitably used by pulverizing limestone, but if it is an inorganic powdery substance mainly composed of calcium carbonate, it is obtained by pulverizing waste concrete or the like and chemically purified. Calcium carbonate or the like can be substituted. Among these, strength development and dimensional stability can be improved by using blast furnace slag fine powder and / or limestone fine powder as the inorganic powder.

Further, these inorganic powders is preferably Blaine specific surface area measured in accordance with JIS R 5201 "Physical testing methods for cement" is 3000 cm ² / g or more, more preferably 3000~8000cm ² / g More preferably, it is 3200-5200 cm < ² > / g.

  Fine aggregates include silica sand, river sand, land sand, sea sand, crushed sand, slag fine aggregate, recycled fine aggregate, waste FCC catalyst, quartz powder, alumina clinker, urethane crushed, EVA foam, It can be appropriately selected from resin pulverized products such as foaming resin. In particular, as the fine aggregate, those selected from sands such as quartz sand, river sand, land sand, sea sand, crushed sand, waste FCC catalyst, quartz powder and alumina clinker can be suitably used.

  The fine aggregate preferably contains less than 10% by mass of coarse particles having a particle diameter of 600 μm or more in 100% by mass of the fine aggregate. The coarse particle content in the fine aggregate is preferably more than 0 to 5% by mass, more preferably more than 0 to 1% by mass, still more preferably more than 0 to 0.5% by mass, and particularly preferably 0. 0.01 to 0.3% by mass. The particle diameter of the fine aggregate can be measured by using several sieves having different nominal dimensions as defined in JIS Z 8801: 2006. In addition, “coarse fraction having a particle diameter of 600 μm or more” refers to the mass ratio of particles on the sieve residue when a sieve having a sieve size of 600 μm is used.

  The self-leveling material in the construction method of the present embodiment preferably contains 30 to 100 parts by mass of inorganic powder and 50 to 200 parts by mass of fine aggregate with respect to 100 parts by mass of the hydraulic component. Thereby, workability | operativity (handling property as a slurry) and hardening characteristic can be improved more.

  The content ratio of the inorganic powder is more preferably 40 to 90 parts by mass, further preferably 45 to 80 parts by mass, and 50 to 70 parts by mass with respect to 100 parts by mass of the hydraulic component. Particularly preferred. The content ratio of the fine aggregate is more preferably 60 to 175 parts by mass with respect to 100 parts by mass of the hydraulic component, still more preferably 70 to 150 parts by mass, and 80 to 125 parts by mass. Particularly preferred.

  As the setting modifier, there are a setting accelerator and a setting retarder, and it is preferable to appropriately select these components and addition amount according to the blending of the hydraulic component to be used. By including a setting regulator, it becomes easy to adjust the pot life (fluid retention) and fast curing of the self-leveling material.

  A well-known thing can be used as a setting retarder. For example, organic acids such as oxycarboxylic acids, sugars such as glucose, maltose, dextrin, sodium bicarbonate, sodium phosphate, etc. may be used alone or in combination of two or more components. it can.

  Oxycarboxylic acids include oxycarboxylic acids and their salts. Examples of oxycarboxylic acid include citric acid, gluconic acid, tartaric acid, glycolic acid, lactic acid, hydroacrylic acid, α-oxybutyric acid, glyceric acid, tartronic acid, malic acid and other aliphatic oxyacids, salicylic acid, m-oxy Mention may be made of aromatic oxyacids such as benzoic acid, p-oxybenzoic acid, gallic acid, mandelic acid and tropic acid.

  Examples of the salt of oxycarboxylic acid include alkali metal salts (specifically sodium salt and potassium salt) and alkaline earth metal salts (specifically calcium salt, barium salt and magnesium salt). Sodium salts are more preferred. In particular, sodium tartrate is preferred from the standpoint of setting delay effect, availability, and price, and more preferably used in combination with sodium bicarbonate.

  The setting retarder is preferably 0.3 to 3.0 parts by mass, more preferably 0.4 to 2.5 parts by mass, and still more preferably 0.5 to 2 parts per 100 parts by mass of the hydraulic component. By using in the range of 0.0 part by mass, particularly preferably in the range of 0.6 to 1.5 parts by mass, it becomes easy to ensure the pot life (handling time) at which suitable fluidity is obtained. Furthermore, by adjusting the addition amount of the setting retarder to the above preferable range, the self-leveling property is improved, and it becomes easy to obtain a slurry having suitable fluidity and sufficient pot life (handling time).

  As a setting accelerator contained in the self-leveling material, a known component for promoting setting can be used. For example, lithium salt, aluminum sulfate, and calcium chloride having a setting acceleration effect can be preferably used, and several 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 acid organics such as lithium oxalate, lithium acetate, lithium tartrate, lithium malate and lithium citrate. A lithium salt can be mentioned. In particular, lithium carbonate is preferable from the viewpoint of the setting acceleration effect, availability, and cost.

  As the setting accelerator, those having a particle size that does not interfere with the properties of the self-leveling material are preferably used, and the particle size is preferably 50 μm or less. Particularly when a lithium salt is used, the particle diameter 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. When the particle diameter of the lithium salt is larger than the above range, the solubility of the lithium salt becomes small, which is not preferable. In particular, in the pigment addition system, it is noticeable as a large number of fine spots, and the appearance may be impaired.

  The setting accelerator is preferably 0.01 to 1.0 part by weight, more preferably 0.02 to 0.5 part by weight, and still more preferably 0.04 to 0 part per 100 parts by weight of the hydraulic component. .25 parts by mass, particularly preferably in the range of 0.05 to 0.15 parts by mass, is preferable because suitable fast-curing properties can be easily obtained while ensuring the pot life of the self-leveling material.

  As the antifoaming agent, known materials such as synthetic materials such as silicon-based, alcohol-based and / or polyether-based materials and / or natural materials derived from plants can be used.

  The antifoaming agent is preferably 0.5 to 5.0 parts by mass, more preferably 0.75 to 4.0 parts by mass, and still more preferably 1.0 to 3.0 parts with respect to 100 parts by mass of the hydraulic component. It is preferable to include 1.25 to 2.0 parts by mass, particularly preferably 1.25 to 2.0 parts by mass. By including an antifoamer within the above range, it becomes easy to obtain an antifoaming effect.

  As described above, the self-leveling material according to the present embodiment is excellent in the balance between fluidity, fast curing, and quick drying, and thus water gradient construction can be suitably performed.

<Self-leveling material slurry>
Next, the self-leveling material slurry according to the present embodiment will be described. The self-leveling material slurry can be prepared by kneading the self-leveling material and water. Also, self-leveling materials (hydraulic components, thickeners, fluidizing agents, re-emulsifying resin powders, inorganic powders, fine aggregates, antifoaming agents, and setting modifiers) are applied in the form of bags. Prepare slurry by bringing it into the site, making it into a premix powder using a mixer such as an on-site mixing / kneading device or hand mixer near the construction site, and mixing it with a predetermined amount of water. You can also. Further, by adjusting the amount of water added, the fluidity of the slurry, the pot life and material separation, the strength of the slurry cured body layer, and the like can be adjusted.

Furthermore, in a large-scale site where the construction area exceeds 200 m ² , use a lorry vehicle that can continuously prepare a self-leveling material slurry by mixing a predetermined amount of water and a self-leveling material continuously. Can do.

  The construction thickness of the self-leveling material slurry varies depending on the unevenness state or the inclined state of the concrete floor surface or the first primer film layer, and the thickness can be appropriately set for each construction site. For example, on the basis of the uppermost surface of the most convex part, the construction thickness is preferably in the range of 2 to 70 mm, more preferably in the range of construction thickness of 2.5 to 50 mm, more preferably in the range of construction thickness of 3 to 40 mm, particularly preferably. Is preferably cast in a thickness range of 3.5 to 30 mm.

  The slurry has a mass ratio (W / S) of water (W) and self-leveling material (S) of preferably 0.18 to 0.26, more preferably 0.19 to 0.25, and even more preferably 0. .20 to 0.24, and particularly preferably 0.21 to 0.23.

  From the viewpoint of the fluidity and fluidity of the slurry, the flow value of the slurry is 190 mm or more, preferably 190 mm or more and less than 230 mm, more preferably 190 to 225 mm, still more preferably 190 to 220 mm. When the flow value is in the above range, it is suitable for water gradient construction, and the slurry hardened body layer surface having high smoothness tends to be easily obtained.

  The self-leveling property of the slurry can be evaluated using a self-leveling (SL) measuring device shown in FIG.

  FIG. 2 is a perspective view schematically showing an SL measuring instrument used for evaluating the self-leveling property of the slurry. The SL measuring instrument 50 is made of a synthetic resin and has an inner dimension of 30 mm width × 30 mm height × length 750 mm. It is bowl-shaped, and only one end is an open end. The SL measuring device 50 includes a filling portion 51 for filling the slurry 10 on the closed end side, and a dam plate made of synthetic resin for damming the filled slurry 10 adjacent to the filling portion 51. 52, and the filling part 51 has a capacity of 30 mm in width, 30 mm in height, and 150 mm in length.

  FIG. 3 is a cross-sectional view schematically showing a method for evaluating the self-leveling property of a slurry using such an SL measuring device. The self-leveling property is evaluated in an environment of a temperature of 30 ° C. and a humidity of 65%. First, as shown in FIG. 3A, the slurry 10 immediately after kneading is poured so as to fill the filling portion 51. Next, when the weir plate 52 is pulled up, the poured slurry 10 flows toward the opening end side of the SL measuring device 50 as shown in FIG.

  The time required for the slurry 10 that has flowed out to flow a distance of 200 mm from the mark 53 is the SL flow time (seconds), and the distance from the mark 53 to the end point 54 where the flow of the slurry 10 stops is the SL value (mm). And The self-leveling property of the slurry can be evaluated by changing the holding time of the slurry 10 in the filling unit 51 and measuring the SL flow time and the SL value.

  Immediately after the slurry 10 is poured into the filling part 51 (holding time 0 minutes, hereinafter referred to as “L0”), the flow time (L0) in which the slurry plate 52 is pulled up and the slurry 10 flows through a distance of 200 mm is preferably 8 -25 seconds, more preferably 9-24 seconds, still more preferably 10-23 seconds.

  The SL value (L0) of the slurry 10 is preferably 260 to 430 mm, more preferably 265 to 425 mm, and still more preferably 270 to 420 mm.

  Also, after pouring the slurry 10 into the filling section 51 and holding it for 20 minutes (hereinafter referred to as “L20”), the weir plate 52 is pulled up, and after the flow of the slurry 10 stops, from the gauge point 53 to the end point 54 of the slurry 10 The SL value (L20), which is the distance, is 100 mm or more, preferably 105 mm or more, more preferably 110 mm or more, still more preferably 115 mm or more, and particularly preferably 120 mm or more. When the value of L20 is in the above range, the slurry tends to be excellent in fluidity.

  Further, the pot life (handling time) of the slurry is preferably 60 minutes, more preferably 50 minutes, still more preferably 40 minutes, and particularly preferably 30 minutes. By providing the pot life, good workability can be ensured.

  As mentioned above, according to the construction method of this embodiment, the construction method of a concrete floor structure suitable for water gradient construction and the method by using a self-leveling material excellent in the balance between fluidity, fast curing and quick drying. The concrete floor structure obtained by can be provided.

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

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

(1) Hydraulic component Alumina cement [AC] (Fonju, Kerneos, Blaine specific surface area 3100 cm ² / g)
Portland cement [PC] (early strength Portland cement, manufactured by Ube Mitsubishi Cement Co., Ltd., Blaine specific surface area 4500 cm ² / g)
Gypsum [GG] (Natural anhydrous gypsum, Blaine specific surface area 4500 cm ² / g)

  The said material was mix | blended in the ratio shown in Table 1, and the hydraulic component was prepared.

(2) Inorganic powder Blast furnace slag fine powder [BFS] (Reverment, manufactured by Chiba Riverment Co., Ltd., Blaine specific surface area 4400 cm ² / g)
(3) Fine aggregate Silica sand [S] (coarse fraction having a particle diameter of 600 μm or more = 0.1 mass%, water absorption = 1.25%, coarse grain ratio 1.15, unit volume mass = 1.53 kg / L, actual rate = 57.5%)
(4) Fluidizing agent Polycarboxylic acid based fluidizing agent (Kao Corporation)
(5) Setting retarder Na tartrate (manufactured by Fuso Chemical Industries)
(6) Setting accelerator Lithium carbonate (Honjo Chemical Co., Ltd.)
(7) Antifoaming agent Polyether-based antifoaming agent (manufactured by San Nopco)
(8) Re-emulsifying resin powder Vinyl acetate-veova-acrylic copolymer re-emulsifying resin powder (Nichigomo Vinyl)
(9) Cellulose-based thickener Hydroxyethyl methylcellulose-based thickener (Matsumoto Yushi Co., Ltd., viscosity = 28800 mPa · s)
The viscosity of the hydroxyethyl methylcellulose-based thickener was measured with respect to an aqueous solution (20 ° C.) containing 2% by mass of the thickener using a B-type viscometer (Toki Sangyo Digital Viscometer, DVL-B type). In this measurement, the rotational speed was 12 rpm, and the rotor No. 4 was used.

(10) Bentonite Bentonite 1 (manufactured by BASF Pozzolith, average particle diameter 24.9 μm)
Bentonite 2 (manufactured by Rockwood ADDITIVES, average particle size 70.8 μm)

  The average particle size of bentonite is determined from the particle size distribution of bentonite (see FIG. 4) measured using a laser diffraction / scattering particle size distribution measuring device (trade name “Laser Micron Sizer LMS-30” manufactured by Seishin Enterprise Co., Ltd.). A diameter-cumulative sieve mass% curve was prepared, and the particle diameter at which the cumulative mass% in the particle diameter-integrated sieve mass% curve was 50% was defined as “average particle diameter”. The sample dispersion solvent was ethanol, the sample dispersion time by ultrasonic before measurement was 60 seconds, the dispersion time by pump circulation was 60 seconds, and the number of data acquisition was 300 times. The laser diffraction method used both Fraunhofer diffraction and Mie scattering. The light source was a semiconductor laser with a wavelength of 670 nm, an output of 2 mW, and a relative refractive index (particle refractive index / solvent refractive index) of 1.330.

[Preparation of self-leveling material]
The said material was mixed by the mixture ratio (mass part) shown in Table 2 or Table 3, and the self-leveling material of an Example and a comparative example was prepared.

FIG. 5 is a diagram showing the relationship between the content of the cellulose-based thickener and the content of bentonite 1 with respect to 100 parts by mass of the hydraulic component in the self-leveling materials of Examples 1 to 13 and Comparative Examples 1 to 7. As shown in FIG. 5, the content (X) of the cellulose-based thickener and the content (Y) of bentonite 1 in Examples 1 to 13 are straight lines represented by the following formulas (2) to (5). It was located inside the enclosed range (except on the formula (4) and the formula (5)). On the other hand, in Comparative Examples 1-7, it was outside the above range.
Y = -21.2X + 2.81 (2)
Y = -21.2X + 3.86 (3)
X = 0.06 (4)
X = 0.14 (5)

[Preparation of slurry]
The self-leveling material (1.5 kg) was kneaded with a Hobart mixer to obtain a premix powder. 330 g of water was added to the obtained premix powder and kneaded for 3 minutes to obtain a slurry. The slurry was prepared in a constant temperature room at a temperature of 20 ° C.

[Flow value]
The flow value was measured according to JASS 15M-103 “The Architectural Institute of Japan: Quality standards for self-leveling materials”. The measurement was performed in a constant temperature room at a temperature of 20 ° C. The measurement results are shown in Tables 4 and 5.

[Self-leveling (SL) value]
In the SL measuring device 50 shown in FIG. 2, the slurry immediately after the kneading is poured into the filling portion 51, and the weir plate 52 is pulled up immediately after pouring (holding time 0 minutes), and the height flowing out from the filling portion 51 as shown in FIG. After the flow of the fluidized mortar slurry stopped, the distance from the reference point (weir plate installation part) 53 to the end point 54 where the flow of the highly fluidized mortar slurry 10 stopped was measured as the SL value (L0). The SL flow time (L0) required for the high-fluid mortar slurry to flow a distance of 200 mm from the mark 53 was measured. Similarly, the weir plate 52 was pulled up 20 minutes after the slurry 10 was filled, and after the flow of the slurry 10 was stopped, the distance from the gauge point 53 to the end point 54 of the slurry 10 was measured as the SL value (L20). The measurement results are shown in Tables 4 and 5.

[Elevation difference (gradient)]
After pouring the slurry up to a height of 8 mm into a synthetic resin container having an inner dimension of width 130 × length 190 × height 17 mm, using a trowel toward the opposite end from the end in the length direction, The slurry surface was smoothed to provide a 7/100 gradient. After the slurry was cured, the height of the end portion in the length direction and the height of the opposite end portion were measured, and the difference was defined as the height difference (gradient). The measurement results are shown in Tables 4 and 5.

[Watering time]
After pouring the prepared slurry into a synthetic resin container having an inner dimension of width 130 × length 190 × height 17 mm so as to have a thickness of 15 mm, the surface water of the cured body disappears as the condensation starts (light light The time when the reflection was lost and clouded was measured as the watering time. The measurement results are shown in Tables 4 and 5.

[surface hardness]
After a predetermined elapsed time since the slurry was cast, the hardness of the hardened surface (Shore hardness) was determined by using a spring type hardness tester type D type (manufactured by Ueshima Seisakusho Co., Ltd.) and the surface hardness at any four locations. The average value of the readings of the spring type hardness tester type D gauge was taken as the surface hardness at that time. In this example and comparative example, the Shore hardness after 2 hours and 24 hours was measured. The measurement results are shown in Tables 4 and 5.

[Surface flatness]
The surface flatness is evaluated by pouring the obtained slurry into a synthetic resin container having an internal dimension of width 130 × length 190 × height 17 mm so as to have a thickness of 15 mm. did. When the presence of surface irregularities was not recognized even when touched with a finger, it was judged as “good”. When the presence of whitening (powdering) or surface irregularities was obvious by visual observation or the like, it was judged as “bad”. The measurement was performed in an environment of a temperature of 30 ° C. and a humidity of 65%. The evaluation results are shown in Tables 4 and 5.

  As shown in Table 4, in Examples 1 to 13, the flow value, the SL value (L0, L20), the flow time (L0), and the height difference (gradient) all show suitable values. It was confirmed that it became a slurry of a self-leveling material excellent in balance between hardness and quick-drying and suitable for water gradient construction. On the other hand, as shown in Table 5, in Comparative Examples 1 to 10, at least one of the above indicators did not show a suitable value, and the balance between fluidity, fast curing and quick drying was not sufficient.

[Construction test in external environment]
The materials were mixed at the blending ratio (parts by mass) of Example 5 to obtain 25 kg of a premix powder of a self-leveling material. 5.5 kg of water was added to the obtained premix powder (water powder ratio: 22%) and kneaded for 3 minutes with a hand mixer to obtain slurries of Examples 14 to 16. Here, each slurry was prepared in an external environment at a temperature of 28.5 ° C.

  As shown in FIG. 6, the slurries of Examples 14 to 16 were applied on the concrete floor of the apartment veranda. Specifically, as shown in FIG. 6 (1), on the concrete floor 1 having a gradient degree of 0/1000, a1 is 3 mm, a2 is 13 mm, and the length a3 is 2000 mm. The slurry was applied. The gradient degree of the formed slurry cured body layer 4b was 5/1000.

Further, as shown in FIG. 6 (2), b4 is 20 mm, on a concrete floor 1 gradient degree 10/1000, as b1 there is 12 mm, b2 is 10 mm, length _{b 3} becomes 2000 mm, The slurry of Example 15 was applied. The gradient degree of the formed slurry cured body layer 4b was 9/1000.

  Furthermore, as shown in FIG. 6 (3), on a concrete floor 1 having c4 of 40 mm and a gradient of 20/1000, the c1 is 5 mm, the c2 is 5 mm, and the length c3 is 2000 mm. The slurry of Example 16 was applied. The gradient degree of the formed slurry cured body layer 4b was 20/1000.

  About the slurry hardened body layers 4b of Examples 14 to 16 constructed in the external environment as described above, when evaluated by visual observation or touching with a finger, the presence of unevenness on the surface was not confirmed, and the flatness of the surface was Both were good.

[Adhesion strength]
First, in a thermostatic chamber at a temperature of 20 ° C., 70 g / m ^{2 of a} primer for a self-leveling material mainly composed of a commercially available acrylic-styrene copolymer resin is applied onto a concrete pavement board of 300 mm × 300 mm × 60 mm and dried. Thus, a first primer film layer was formed.

  Next, the materials were mixed at the blending ratio (parts by mass) of Example 5 to obtain 25 kg of a premix powder of a self-leveling material. 5.5 kg of water was added to the obtained premix powder (water powder ratio: 22%), and the mixture was kneaded for 3 minutes with a hand mixer to obtain a slurry of Example 17. The slurry of Example 17 was placed on the first primer film layer so as to have a thickness of 10 mm, and was cured for 14 days to obtain a cured slurry layer.

  Next, as a primer for a coating floor material, 50 parts by mass of a curing agent and 75 parts by mass of an inorganic filler with respect to 100 parts by mass of a base for a commercially available primer for a coating floor material (epoxy two-component mixed type) They were blended at a ratio and kneaded for 3 minutes using a chemistor with a rotation speed of 650 rpm. The above preparation was carried out in an environment at room temperature of 20 ° C. and a relative humidity of 65% to obtain a primer for a coating floor material.

On the said slurry hardened | cured material layer, it applied using the roller brush so that it might become 150 g / m < ² > of the prepared primer for coating floor materials, it was made to harden | cure, and the 2nd primer membrane | film | coat layer was formed.

  Next, as a base coat for a coating floor material, a curing agent is blended at a ratio of 20 parts by mass with respect to 100 parts by mass of a base of a base coating for a coating floor material (epoxy two-component mixed type), and the number of rotations The mixture was kneaded for 3 minutes using a 650 rpm chemistor. The above preparation was performed in an environment at room temperature of 20 ° C. and a relative humidity of 65% to obtain a base coat for a coating floor material.

On the second primer film layer, the prepared base coat for a coating floor material was applied using a scissors so as to be 300 g / m ² and cured to form a first base coat layer. Further, a similar base coat for a flooring material was applied on the first base coat layer using a scissors so as to be 800 g / m ² and cured to form a second base coat layer. This test body was aged for 7 days, and the concrete floor structure of Example 17 was produced.

With respect to the concrete floor structure of Example 17, the adhesion strength was measured according to NNK-005: 2006 “Japan Coated Floor Industry Association: Adhesion Strength Test Method for Coated Floor Materials” and found to be 4.5 N / mm ^2. Met. This greatly exceeds 1.5 N / mm ² , which is the reference value of the adhesion strength of the coating floor material in the Japan Paint Floor Industry Association, and the concrete floor structure of Example 17 has excellent adhesion strength. It was confirmed.

  DESCRIPTION OF SYMBOLS 1 ... Concrete floor, 2 ... Floor upper surface, 3 ... 1st primer film layer, 4a ... Self-leveling material slurry layer, 4b ... Slurry hardening body layer, 5 ... Soot, 6 ... 2nd primer film layer, 7 ... Basecoat Layer, 8 ... topcoat layer, 9 ... concrete floor structure, 10 ... slurry, 50 ... SL measuring device, 51 ... filling section, 52 ... weir plate, 53 ... gage, 54 ... end point.

Claims (7)

A method for constructing a concrete floor structure having a step of placing a self-leveling material slurry prepared by kneading a self-leveling material and water on a floor surface of a building and forming a slurry hardened body layer,
The self-leveling material includes 20 to 80% by mass of alumina cement, 5 to 70% by mass of Portland cement and 5 to 45% by mass of gypsum, a fluidizing agent, and a thickener.
The thickener contains a cellulosic thickener and bentonite having an average particle size of 30 μm or less, and the content of the cellulosic thickener and the content of the bentonite with respect to 100 parts by mass of the hydraulic component. A construction method that satisfies the relationship represented by the following formula (1).
Y = -21.2X + t (1)
[Wherein, X represents the content (parts by mass) of the cellulose-based thickener, 0.06 <X <0.14, Y represents the content (parts by mass) of the bentonite, and t represents A coefficient is shown, and 2.81 ≦ t ≦ 3.86. ]   The construction method according to claim 1, wherein the self-leveling material further includes a re-emulsifying resin powder.   The construction method according to claim 2, wherein the re-emulsified resin powder contains a vinyl acetate-veova-acrylic copolymer and / or an acrylic-methacrylic copolymer.   The construction method according to any one of claims 1 to 3, wherein the self-leveling material further includes at least one component selected from an inorganic powder, a fine aggregate, a setting regulator, and an antifoaming agent.   Before forming the said slurry hardened | cured material layer, it has further the process of apply | coating the primer for self-leveling materials to the floor upper surface of the said building, and forming the 1st primer membrane | film | coat layer. The construction method described in the item. Applying a primer for a coating floor material on the upper surface of the slurry cured body layer to form a second primer film layer;
Applying a coating floor base coat on the upper surface of the second primer coating layer to form a coating floor base coat layer;
The construction method according to any one of claims 1 to 5, further comprising: The concrete floor structure obtained by the construction method of any one of Claims 1-6.