JP2010077753A - Construction method of concrete-floor structure - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a construction method of a concrete-floor structure with a smooth slope excellent in durability for the construction in the outdoor environment, whose drainage slope is easily formed and which is excellent in workability, high in execution efficiency and good in surface finish while the surface can be repaired by trowel-pressing in a semi-hardened state. <P>SOLUTION: The construction method for the concrete-floor structure includes: a step for casting mortar 14, which is prepared with a levelling material containing re-emulsion resin power of acrylic copolymer, into a top surface 12 of the concrete floor to 0.5-30 mm thick; a step for levelling the casted mortar surface with a trowel; and a step for smoothly finishing the surface of the mortar-hardened body by pressing the surface of the mortar-hardened body in the semi-hardened state with the trowel. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

The present invention relates to a method for constructing a concrete floor structure that can be applied to various buildings and is obtained by using a hydraulic composition that is excellent in workability, quick curing, and dimensional stability.
Furthermore, the present invention uses a hydraulic composition that can be applied to a concrete floor of various buildings having a gradient, is excellent in workability, quick-hardness, and dimensional stability, and can be applied to correct a delicate level difference. It is related with the construction method of the concrete floor structure which has the gradient obtained by this.

The balconies and shared corridors attached to the building are exposed to the wind and rain because they are located outdoors, and in order to prevent rainwater from accumulating on the concrete floor, In particular, a gradual water gradient is formed on the concrete floor surface by constructing mortar using plasterers.

Regarding a cement-based coating agent excellent in durability such as water permeability, freeze-thaw resistance and chemical resistance, and adhesion to a base material, Patent Document 1 uses cement, fine particle inorganic powder, dispersant and emulsion polymer. Also disclosed is a hydraulic cementitious coating composition, optionally comprising fine aggregate and water.

Further, as an elastic surface material that forms a flat surface layer by flowing on a floor surface of a building, a roof surface, and a floor surface of an athletic field such as a tennis court or a volleyball court, Patent Document 2 discloses a cement-based self-leveling property. An elastic surface finishing material obtained by adding a cationic synthetic resin emulsion to a floor mortar finishing material is disclosed.

JP-A-5-65427 JP-A-62-187187

The floors of apartments, such as the common corridors and balconies, cannot be obtained with a concrete presser, so the required accuracy of the water gradient cannot be obtained. In addition, finishing with long sheets such as vinyl chloride is increasing.
In this case, the floor repair requires skill to finely adjust the slope, but due to the aging of the plasterer and the decrease in the number of workers, mass construction in a short period of time has become difficult.
In addition, since corridors and balconies are used as work passages, it is desirable to shorten the period of prohibition of traffic, but due to delays in curing of plastering repair materials at low temperatures, entry of other contractors before curing, construction, and weathering during curing Combined with re-repair, the construction period is often long.
Against this background, in recent years, high fluidity type mortars have become widespread for the purpose of labor saving, but the current situation is that the curing speed is slow and the construction period has not been shortened.
In addition, since the construction is performed in a place exposed to sunlight or wind, there are problems such as wrinkles and traces of bubbles due to drying of the mortar surface, and cracks in the cured body.

In the construction in the outdoor environment, the present invention is easy to form a water gradient, excellent workability, high construction efficiency, good surface finish, and can be reworked with a tack during semi-curing, An object of the present invention is to provide a method for constructing a concrete floor structure having excellent durability and a smooth slope surface.

As a result of diligent research and development on the above problems, the present inventors use a leveling material that includes a hydraulic component that is excellent in fast curing and quick drying properties and a specific acrylic copolymer re-emulsified resin powder. Therefore, it has excellent flowability and excellent casting workability, and also has excellent lacquering workability, long handling properties (pot life), and quick curing after a predetermined pot life has elapsed. The construction method of the concrete floor structure using the hydraulic composition which progressed and the early stage strength expression was favorable and can form the floor surface which has a gradient was discovered. In addition, by maintaining the semi-cured state of the cast mortar for a long time, we found a hydraulic composition that can easily form a smooth finished surface by correcting the surface rework caused by pressing and correcting subtle steps on the construction surface. Completed the invention.

That is, the first of the present invention is a step of pouring a mortar prepared using a leveling material containing an acrylic copolymer-based re-emulsifying resin powder to a concrete floor upper surface to a thickness of 0.5 to 30 mm; A concrete floor structure comprising a step of leveling a poured mortar surface with a trowel, and a step of smoothing the surface of the mortar cured body by pressing a trowel on the surface of the semi-cured mortar cured body. This is the construction method.
The second aspect of the present invention is a concrete floor structure in which the upper surface of the concrete floor structure obtained by the construction method of the present invention has a gradient of more than 0/1000 and not more than 50/1000.

A preferable aspect of the construction method of the concrete floor structure having excellent surface smoothness according to the present invention will be described below. A plurality of these can be combined.
1) The mortar cured body surface in a semi-cured state has a Shore hardness of 1-20.
2) The leveling material should contain hydraulic components consisting of alumina cement, Portland cement and gypsum.
3) The leveling material includes a hydraulic component and an acrylic copolymer-based re-emulsified resin powder, and is further selected from inorganic powder, fine aggregate, setting agent, fluidizing agent, thickener and antifoaming agent. Containing at least one component.
4) The acrylic copolymer re-emulsified resin powder is an acrylic ester / methacrylic ester copolymer re-emulsified resin powder.
5) The acrylic copolymer-based re-emulsified resin powder is blended at a ratio of 1 to 50 parts by mass with respect to 100 parts by mass of the hydraulic component.
6) The shore hardness of the surface of the mortar cured body using the leveling material should be 1 or more 4 hours after pouring and applying the mortar.
The concrete floor top surface has a slope of more than 0/1000 and not more than 50/1000.

The concrete floor structure construction method of the present invention selects and uses a leveling material containing a hydraulic component excellent in quick hardening and quick drying and a specific resin powder. The mortar prepared using the leveling material has suitable flowability and excellent pouring workability, and also has excellent glazing workability, long handling properties (pot life), and predetermined pot life After the elapse of time, curing proceeds promptly and provides good early strength development. Furthermore, by using a leveling material, the smearing operation can be easily performed and a smooth surface can be formed.
In addition, the present invention is a method of reworking the surface of the mortar with a thin construction thickness, a mating part, a joining part, etc. Smoothness can be improved, and the entire surface of a concrete floor structure having a gradient can be finished to a smooth finished surface.

An example of an embodiment of a concrete floor structure using the leveling material of the present invention and a concrete floor structure obtained by the construction method will be described with reference to the drawings shown in FIGS.

FIG. 1 a is a partial cross-sectional view showing a concrete floor structure 11 having a gradient.
In the present invention, as shown in FIG. 1b, a leveling material primer 14 is first applied to the surface of a non-smoothed portion 13 such as a concave portion or a missing portion of a concrete floor structure 11 having a gradient.
After the leveling material primer 14 is dried and formed into a film, the leveling mortar 15 is poured onto the upper surface thereof, and the leveling material mortar 15 is applied to the non-smooth portion 13 of the concrete floor structure 11 using a plasterer, a dragonfly, a spike roller, or the like. Spread the surface and smooth the surface with a plasterer along the floor slope.

The preparation and construction of leveling mortar is carried in the form of a bag with the leveling material in the form of a bag, using a mixer such as a field-installed mixing / kneading device or hand mixer near the construction site. The leveling material mortar can be prepared by mixing and kneading the water and the leveling material.

Next, when the leveling material mortar 15 supplied and placed on the concrete floor starts to harden and reaches a semi-hardened state 16 with a shore hardness of 1 to 20 as shown in FIG. 1c, as shown in FIG. 1d. Then, the surface of the semi-cured leveling material 16 is pressed and leveled using a plasterer, and the surface of the semi-cured leveling material 16 is smoothed to obtain a smooth surface of the concrete floor as shown in FIG. 1e. The concrete floor structure 11 which has the gradient excellent in the property and finish can be obtained. Therefore, the concrete floor structure 11 having a gradient in which the leveling material mortar 15 is applied has a smooth entire surface and excellent finish.

On the other hand, since a high level level property can be obtained, the self-leveling material (self-flowing composition) has excellent performance as a floor base material.
However, as shown in FIG. 2, when a self-leveling material (self-flowing composition) is used for repairing a concave portion or a deficient portion on the floor surface having a gradient, the self-leveling material 19 is poured and the mortar surface portion is plastered. Immediately after leveling, etc., a smooth surface can be formed with respect to the gradient surface, but the self-leveling material (self-flowing composition) causes self-flow due to its excellent fluidity, A horizontal level is formed, and it is difficult to form a smooth gradient surface on a floor surface having a gradient.

In particular, when a self-leveling material (self-fluid composition) with excellent fast-curing properties is used, construction work time can be shortened due to its excellent fast-curing properties, while construction efficiency can be increased, but rapidly after the start of curing. Hardening has progressed and there is almost no time in a semi-cured state that can be repaired using a plastering trowel etc. It is difficult to rework the stepped portion 21 of the cured body.

  Next, a primer for leveling material, a leveling material, and a flooring finishing material used in the present invention will be described.

The primer for the leveling material used in the present invention is an action for firmly adhering the concrete floor and the cured leveling material mortar, and when water in the mortar penetrates into the concrete floor when the leveling material mortar is placed. Used to prevent.
As a primer for leveling material, a commercially available primer mainly composed of an acrylic-styrene copolymer resin or an ethylene vinyl acetate copolymer can be used, and a primer mainly composed of an acrylic-styrene copolymer resin is preferably used. it can.
The coating amount of the primer preferably 80~240g / ^{m 2,} more preferably 90~225g / ^{m 2,} more preferably 100 to 200 g / ^{m 2,} particularly preferably good applying 120~180g / ^{m 2} It is preferable for obtaining a stable adhesive strength.
The drying time after application of the primer can be appropriately determined according to 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 leveling material used in the method for constructing a concrete floor structure of the present invention includes a hydraulic component made of alumina cement, Portland cement and gypsum.

  Several types of alumina cement having different mineral compositions are known and commercially available, but the main component is monocalcium aluminate (CA), and commercially available products can be used regardless of the type.

  Portland cement includes ordinary Portland cement, early-strength Portland cement, super-early-strength Portland cement, medium heat Portland cement, low-heat Portland cement, Portland cement such as white Portland cement, mixed cement such as blast furnace cement, fly ash cement, silica cement, etc. Can be used.

As for gypsum, each gypsum such as anhydrous gypsum, hemihydrate gypsum, and dihydrate gypsum can be used as one type or a mixture of two or more types regardless of the type.
Gypsum functions as a component that retains dimensional stability after the mortar obtained by kneading the self-flowing hydraulic composition and water is cured.

The leveling material used in the present invention uses a hydraulic component made of alumina cement, Portland cement and gypsum as the hydraulic component.
The hydraulic component is preferably composed of 20 to 80 parts by mass of alumina cement, 5 to 70 parts by mass of Portland cement, and 5 to 45 parts by mass of gypsum (a total of alumina cement, Portland cement and gypsum is 100 parts by mass). A composition, more preferably 25-70 parts by mass of alumina cement, 10-60 parts by mass of Portland cement and 10-40 parts by mass of gypsum (the total of alumina cement, Portland cement and gypsum is 100 parts by mass), More preferably, the alumina cement is 30 to 60 parts by mass, the Portland cement is 20 to 50 parts by mass, and the gypsum is 15 to 35 parts by mass (the total of the alumina cement, Portland cement and gypsum is 100 parts by mass), particularly preferably the alumina cement. 40-50 parts by weight, Portland Semé 30 to 40 parts by mass and gypsum 20 to 30 parts by mass (the total of alumina cement, Portland cement and gypsum is 100 parts by mass). It is preferable because it is easy to obtain a cured product that is shrinkable or low-expandable, has little volume change during curing, and suppresses the generation of cracks.

In the leveling material used in the present invention, it is preferable to premix and supply the constituent components since the mixing ratio of the constituent components can be strictly controlled. For this reason, a powdered re-emulsified resin powder is used for the resin powder.
The leveling material used in the present invention prevents generation of wrinkles and bubble marks due to drying of the surface of the cured body when the mortar of the leveling material is applied outdoors, or generation of breathing water due to material separation. The re-emulsified resin powder is used to provide the effect of significantly improving the finish and the effect of increasing the elasticity of the cured body and preventing the occurrence of cracks.

In addition, the re-emulsified resin powder has a role of keeping the semi-cured state of the hydraulic composition having fast curing for a long time, and by improving its water retention, the surface of the cured body is reworked by pressing the sheet in a semi-cured state. Can be made possible.

The type and process of the re-emulsifying resin powder is not particularly limited, and those manufactured by a known manufacturing method can be used. As the re-emulsifying resin powder, an anti-blocking agent is mainly used. What has adhered to the surface of the resin powder can be used.
As the re-emulsified resin powder, a water-based polymer dispersion obtained by removing the solvent by a method such as spraying or freeze drying can be suitably used.

In the present invention, an acrylic copolymer-based re-emulsified resin powder produced from a protective colloid acrylic emulsion can be preferably used as the re-emulsified resin powder. A re-emulsified resin powder of a methacrylic acid ester copolymer can be suitably used.

The average particle size of the primary particles (emulsion particles) of the acrylic copolymer re-emulsified resin powder is preferably in the range of 0.2 to 0.8 μm, more preferably 0.25 to 0.75 μm. Range, more preferably in the range of 0.3 to 0.7 μm, particularly preferably in the range of 0.35 to 0.65 μm by selecting and using good workability and dense polymer It is preferable because excellent adhesion, durability, and weather resistance obtained by forming the film can be obtained together.
In a leveling material mortar using an acrylic copolymer-based re-emulsifying resin powder having an average primary particle size in the above-mentioned range, the surface of the mortar is finished with a proper gradient using a plasterer or the like. In the process of carrying out the dredging work, it is possible to obtain good dredging ability and loosening performance.
When the average particle diameter of the primary particles of the re-emulsified resin powder is larger than the above range, the workability during mortar construction is good, but the adhesiveness and durability / weather resistance of the mortar cured body are not preferable, When the average particle size of the primary particles of the re-emulsified resin powder is smaller than the above range, the adhesiveness, durability and weather resistance of the mortar hardened body are good, but the wrinkle feedability and glaring property during mortar construction are good. It is not preferable because the workability is deteriorated due to the decrease.

In the leveling material used in the present invention, the particle size of the primary particles of the re-emulsified resin powder in the acrylic copolymer-based re-emulsified resin powder is preferably 97% by mass, preferably 0.1 to 1 μm. More preferably 95% by mass or more of 0.15-0.9 μm particles, more preferably 90% by mass or more of 0.2-0.8 μm particles, particularly preferably 0.3-0. By selecting and using particles containing 75% by mass or more of .7 μm, it is possible to obtain both excellent workability and excellent adhesion, durability and weather resistance obtained by forming a dense polymer film. This is preferable.
When the primary particles having a particle size in the above range are included in the above range, in the leveling material mortar using the acrylic copolymer re-emulsified resin powder, the mortar surface should be provided with an appropriate gradient using a plastering machine. In the course of carrying out the dredging work to finish the surface smoothly, it is possible to obtain good wrinkle feedability and fraying performance.
When the average particle diameter of the primary particles of the re-emulsified resin powder is larger than the above range, the workability during mortar construction is good, but the adhesiveness and durability / weather resistance of the mortar cured body are not preferable, When the average particle size of the primary particles of the re-emulsified resin powder is smaller than the above range, the adhesiveness, durability and weather resistance of the mortar hardened body are good, but the wrinkle feedability and glaring property during mortar construction are good. It is not preferable because the workability is deteriorated due to the decrease.

The acrylic copolymer-based re-emulsified resin powder used in the present invention preferably has a primary particle coated with a water-soluble protective colloid of polyvinyl alcohol.
The surface of the primary particles of the re-emulsified resin powder is coated with a water-soluble protective colloid of polyvinyl alcohol, so that the state of the emulsion quickly and uniformly in the process of re-emulsification (state before resin powdering) ), That is, a state in which primary particles are uniformly dispersed in the leveling material mortar can be realized.

  In the present invention, an acrylic copolymer-based re-emulsified resin powder containing the primary particle diameter in the above range in the above range and the surface of the primary particle coated with a water-soluble protective colloid of polyvinyl alcohol is selected. By using the mortar, excellent workability at the time of mortar construction can be obtained, and in the cured mortar, properties excellent in adhesion, weather resistance, water resistance and alkali resistance can be obtained.

The acrylic copolymer-based re-emulsified resin powder used in the present invention is used in the form of secondary particles in which primary particles are aggregated through a process such as spray drying.
The particle diameter of the secondary particles of the acrylic copolymer-based re-emulsifying resin powder used in the present invention is preferably in the range of 20 to 100 μm, more preferably in the range of 30 to 90 μm, more preferably 45 to 85 μm. In the process of kneading the leveling material containing the re-emulsified resin powder and water and kneading it into mortar, the secondary particles of the re-emulsified resin powder are particularly preferably in the range of 50 to 80 μm. A re-emulsified resin powder having a secondary particle diameter in the above range is obtained because it is easily pulverized and finely dispersed by the fine aggregate contained in the leveling material, and the primary particles tend to be uniformly dispersed. It is preferable to use it.
If the secondary particle size of the re-emulsified resin powder is larger than the above range, it is difficult to re-disperse during the mortarization process, and the primary particles are not easily dispersed uniformly. When it is smaller than the above range, when pre-mixing at the factory to produce a leveling material, the re-emulsification type resin powder is scattered and handling properties such as a worse working environment are deteriorated.

In the leveling material used in the present invention, the re-emulsifying resin powder is preferably 1 to 20 parts by mass, more preferably 2 to 18 parts by mass, and further preferably 3 to 16 parts by mass with respect to 100 parts by mass of the hydraulic component. By blending in an amount of 4 parts by mass, particularly preferably in the range of 4 to 15 parts by mass, good workability and highly durable cured product characteristics can be obtained together.
When the blending ratio of the re-emulsified resin powder is larger than the above range, the viscosity of the mortar obtained by adding water to the leveling material is increased, the workability and dredging workability are reduced, and wrinkles and bubbles due to drying of the surface layer While it becomes easy to generate | occur | produce a trace, there exists a tendency for the compressive strength of a hardening body to fall. Further, if the blending ratio is smaller than the above range, the thixotropic property of the mortar tends to be lowered and it becomes difficult to stably form a gently inclined surface, and cracks due to improved elasticity of the mortar hardened body. This is not preferable because the suppression effect tends to be small and the surface finish of the mortar cured body tends to be poor.

The leveling material used when constructing a concrete floor structure with a gradient outdoors includes a hydraulic component made of alumina cement, Portland cement and gypsum, and an acrylic copolymer re-emulsified resin powder. It is preferable to include an aggregate, a setting regulator, a fluidizing agent, a thickener, and an antifoaming agent.

The leveling material used in the present invention preferably contains at least one inorganic component selected from blast furnace slag fine powder, fly ash, silica fume, calcium carbonate fine powder and dolomite fine powder, and particularly contains blast furnace slag fine powder. As a result, the crack resistance of the cured product due to drying shrinkage can be increased, and the long-term strength can be increased at low cost.
In the leveling material, the added amount of the inorganic component is preferably 10 to 200 parts by mass, more preferably 20 to 180 parts by mass, still more preferably 30 to 150 parts by mass, and particularly preferably 40 parts per 100 parts by mass of the hydraulic component. It is preferable to set it as -120 mass parts.

In the leveling material, the addition amount of the blast furnace slag fine powder is preferably 10 to 200 parts by weight, more preferably 20 to 180 parts by weight, still more preferably 30 to 150 parts by weight, particularly preferably 100 parts by weight of the hydraulic component. Is preferably 40 to 120 parts by mass. If the amount of blast furnace slag fine powder added is too small, drying shrinkage of the cured product may be increased, and sufficient long-term strength may not be obtained, and if too much, initial strength may be reduced.
As the blast furnace slag fine powder, those having a brain specific surface area of 3000 cm ² / g or more as defined in JIS A 6206 can be used.

The leveling material can further include fine aggregate as required.
The fine aggregate is preferably 30 to 500 parts by mass, more preferably 50 to 400 parts by mass, still more preferably 100 to 300 parts by mass, and particularly preferably 150 to 250 parts by mass with respect to 100 parts by mass of the hydraulic component. Is preferred.
As the fine aggregate, an aggregate having a particle size of 2 mm or less, preferably an aggregate having a particle size of 0.075 to 1.5 mm, more preferably an aggregate having a particle size of 0.1 to 1 mm, particularly preferably 0.15 to 0.15. It is preferable that the main component is an aggregate of 0.6 mm.
Fine aggregates include silica sand, river sand, sea sand, mountain sand, crushed sand, etc., alumina clinker, silica powder, clay mineral, waste FCC catalyst, inorganic materials such as limestone, crushed urethane, EVA foam, foaming resin A resin pulverized product such as can be used.
In particular, as fine aggregates, sand such as quartz sand, river sand, sea sand, mountain sand, crushed sand, waste FCC catalyst, quartz powder, alumina clinker and the like can be preferably used.
The particle size of the fine aggregate is measured using several sieves having different nominal dimensions as defined in JIS Z 8801.

As the leveling material, a fluidizing agent (water reducing agent such as a high performance water reducing agent) that secures suitable fluidity while suppressing material separation is used.
Since the expression strength of alumina cement, which is a hydraulic component, is greatly affected by the water / cement ratio, it is particularly preferable to reduce the water / hydraulic component ratio by using a fluidizing agent having a water reducing effect.
As the fluidizing agent, commercially available fluidizing agents such as formaldehyde condensate of melamine sulfonic acid, casein, calcium caseinate, polycarboxylic acid, polyether, etc., which have a water reducing effect, such as polyether polycarboxylic acid, It can be used regardless of the type, and a commercially available fluidizing agent such as polyether-based polycarboxylic acid such as polyether-based is particularly preferable.
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 of the hydraulic component. Can be blended in an amount of 0.02 to 1.0 parts by mass, particularly preferably 0.05 to 0.5 parts by mass. If the amount added is too small, no suitable effects (excellent fluidity and high cured product strength) will be exhibited, and if the amount added is too large, an effect commensurate with the amount added cannot be expected and it is merely uneconomical. However, it may be difficult to form a gradient surface due to a decrease in thixotropic properties.

  The setting modifier can be added as appropriate within the range that does not impair the properties, depending on the hydraulic component used and the component of the leveling material, and the components, addition amount and mixing ratio of the setting retarder and setting accelerator are appropriately set. It is preferable that the leveling material can be selected and the pot life and quick hardening / drying property can be adjusted, and the use as the leveling material becomes very easy.

As the setting retarder, a known setting retarder can be used. Examples of setting retarders include oxycarboxylic acids such as sodium tartrate (monosodium tartrate, disodium tartrate), sodium malate, sodium citrate, and sodium gluconate, and inorganic sodium salts such as sodium sulfate and sodium bicarbonate. Each component can be used alone or in combination of two or more components.

Oxycarboxylic acids include oxycarboxylic acids and their salts.
Examples of the oxycarboxylic acid include aliphatic oxyacids such as citric acid, gluconic acid, tartaric acid, glycolic acid, lactic acid, hydroacrylic acid, α-oxybutyric acid, glyceric acid, tartronic acid, malic acid, salicylic acid, and m-oxybenzoic acid. Examples thereof include aromatic oxyacids such as acid, p-oxybenzoic acid, gallic acid, mandelic acid and tropic acid.
Examples of oxycarboxylic acid salts include alkali metal salts of oxycarboxylic acids (specifically, sodium salts, potassium salts, etc.), alkaline earth metal salts (specifically, calcium salts, barium salts, magnesium salts, etc.), etc. Can be mentioned.
In particular, sodium bicarbonate and disodium L-tartrate are preferred from the standpoints of setting delay effect, availability, and cost.

When one or more kinds of setting retarders are used, the amount of each setting retarder added is preferably 0.01 to 1.5 parts by mass, more preferably 100 parts by mass with respect to the hydraulic component. 0.1 to 1.2 parts by mass, more preferably 0.2 to 1.0 parts by mass, and particularly preferably 0.25 to 0.8 parts by mass. It is preferable because the working time can be secured.

As the setting accelerator, a known component that promotes setting can be used. For example, it is preferable to use a lithium salt having a setting acceleration effect.
Examples of lithium salts include inorganic lithium salts such as lithium carbonate, lithium chloride, lithium sulfate, lithium nitrate, and lithium hydroxide, and organic acid organic lithium salts such as lithium acetate, lithium tartrate, lithium malate, and lithium citrate. Lithium salts can be used. In particular, lithium carbonate is preferable from the viewpoints of the setting acceleration effect, availability, and cost.
In addition, it is particularly preferable to use a coagulation promoting component such as aluminum sulfate, potassium sulfate, sodium aluminate or the like in combination with the above lithium salt because a further promoting effect is exhibited.

As the setting accelerator, it is preferable to use a particle size that does not interfere with the properties, 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 not more than 50 μm, more preferably not more than 30 μm, particularly preferably not more than 10 μm. Then, it may be conspicuous as a large number of fine spots, and the appearance may be impaired.

  The setting accelerator is preferably 0.01 to 2 parts by mass, more preferably 0.01 to 1 part by mass, and further preferably 0.02 to 0.5 parts by mass with respect to 100 parts by mass of the hydraulic component. In particular, it is preferable to use it in the range of 0.02 to 0.3 parts by mass, since suitable quick hardening and quick drying properties can be obtained after securing the pot life of the leveling material.

Thickener contains hydroxyethyl methylcellulose, and uses other thickeners other than hydroxyethylmethylcellulose, processed starch such as starch ether, protein, latex, and water-soluble polymer. be able to.
The addition amount of the thickener can be added within a range not impairing the characteristics of the present invention, and is preferably 0.001 to 2 parts by mass, more preferably 0.005 to 100 parts by mass of the hydraulic component. It is preferable to include 1.5 parts by mass, more preferably 0.01 to 1 part by mass, particularly 0.05 to 0.8 parts by mass. When the addition amount of the thickener is increased, the mortar viscosity is increased and the fluidity may be lowered. Therefore, it is preferably used in the above preferred range.

  Using a thickener and an antifoaming agent together has a favorable effect on suppressing separation of aggregates such as hydraulic components and fine aggregates, suppressing generation of bubbles, and improving the surface of the cured body, and hardening the leveling material. It is preferable for improving the properties of the product.

As the antifoaming agent, known materials such as synthetic materials such as silicon-based, alcohol-based and polyether-based materials, mineral oil-based materials, and plant-derived natural materials can be used alone or in combination of two or more.
The addition amount of the antifoaming agent can be added within a range that does not impair the characteristics of the present invention. When one type of antifoaming agent is used, preferably 0.001 to 3 parts relative to 100 parts by mass of the hydraulic component. 0.0 part by mass, more preferably 0.005 to 2.5 parts by mass, more preferably 0.01 to 2.0 parts by mass, and particularly preferably 0.05 to 1.5 parts by mass. The addition amount of the antifoaming agent is preferably within the above range because a suitable antifoaming effect is recognized.
In addition, when two or more kinds of antifoaming agents are used in combination, the addition amount of the antifoaming agent is preferably 0.001 to 2 parts by mass with respect to 100 parts by mass of the hydraulic component. More preferably, it is 0.005 to 1.5 parts by mass, more preferably 0.01 to 1.3 parts by mass, and particularly preferably 0.02 to 1.0 parts by mass. The addition amount of the antifoaming agent is preferably within the above range because a suitable antifoaming effect is recognized.

In the case of constituting the leveling material used in the present invention, particularly suitable component constitutions are fine components such as hydraulic components made of alumina cement, Portland cement and gypsum, acrylic copolymer-based re-emulsified resin powder, inorganic components, silica sand and the like. It contains aggregates, fluidizing agents, thickeners, antifoaming agents and setting modifiers.

In the present invention, a hydraulic component and an acrylic copolymer-based re-emulsified resin powder, an inorganic component, a fine aggregate, a fluidizing agent, a thickening agent, an antifoaming agent, a setting modifier, and the like are mixed in a mixer and leveled. A premix powder of the material can be obtained.

The premix powder of the leveling material can be mixed and stirred with a predetermined amount of water to produce a mortar having leveling properties, and the cured mortar can be obtained by curing the mortar.
In the present invention, the mortar having leveling property means a mortar having good fluidity that does not have self-leveling property (self-fluidity) and can be easily spread using a construction tool. To do.

The leveling material can be mixed and stirred with water to produce mortar. By adjusting the amount of water added, the mortar fluidity, pot life, material separation, and strength of the mortar hardened body are adjusted. can do.
The leveling material mortar used in the present invention has a mass ratio (W / S) of the leveling material (S) and water (W) of preferably 0.14 to 0.34, more preferably 0.16 to 0. .32, more preferably 0.18 to 0.30, and particularly preferably 0.20 to 0.28.

  In the leveling material used in the present invention, the flow value of the mortar having leveling properties prepared by mixing with water is preferably adjusted to 140 to 209 mm, more preferably 160 to 208 mm, and particularly preferably 180 to 207 mm. It is preferable for the reason that the leveling material mortar does not self-flow, and that it is easy to obtain a hardened product surface with high smoothness while forming an appropriate gradient.

The construction thickness of the leveling material mortar varies depending on the unevenness of the concrete floor surface and the gradient state of the concrete floor surface, and can be set appropriately for each construction site. As a standard, the construction thickness is preferably in the range of 0.5 mm to 30 mm, more preferably in the range of construction thickness of 1 mm to 20 mm, more preferably in the range of construction thickness of 1.5 mm to 15 mm, and particularly preferably construction thickness of 2 mm. It is preferable to perform the pouring work in the range of -10 mm.
When thinning the leveling material mortar to a height of 0.5 mm to 10 mm with reference to the top surface of the most convex part of the concrete floor, the mortar is poured using a spike roller, a dragonfly, a trowel, etc. while pouring the mortar. A concrete floor having a smooth sloped surface by performing an operation of spreading evenly, forming the mortar layer into a thin layer on the concrete floor, and pressing the plaster board when the leveling material mortar is semi-hardened. It is preferable to finish the surface.

The leveling material mortar used in the present invention has sufficient pot life (handling time) to ensure good workability.
The pot life of the leveling material mortar is preferably 60 minutes from the preparation of the mortar, more preferably 40 minutes, and particularly preferably 30 minutes.

Although the leveling material mortar depends on the temperature and humidity conditions of the construction site, it begins to cure within 1 to 4 hours after the completion of construction, and the Shore hardness of the cured body surface increases with the progress of curing. After passing through a semi-cured state having a shore hardness of 1 to 20, the shore hardness of the cured body surface and the cured body strength increase, and the moisture content of the cured body surface decreases.
The shore hardness of the surface of the leveling material mortar cured body is preferably 1 or more after 4 hours, 10 or more after 5 hours, more preferably 1 or more after 3 hours, and 10 or more after 4 hours from the placement (construction) of the mortar, More preferably, it is 1 or more after 2 hours, 10 or more after 3 hours, particularly preferably 1 or more after 1 hour, and 10 or more after 2 hours.
Since the leveling material mortar has such an appropriate fast curing property, after the mortar construction (placement / surface finishing) is finished, the curing proceeds promptly to a semi-cured state with a shore hardness of 1 to 20, and the leveling material When the mortar is in a semi-cured state, the leveling material mortar is completed by finishing the surface smoothly by pressing the surface.

The leveling material used in the present invention has characteristics excellent in quick curing and quick drying, and has a semi-cured state with a shore hardness of 1 to 20 that is suitable for wrinkle-holding treatment for a predetermined time, and thereafter excellent. By exhibiting fast curing properties, a good cured state and a surface-dried state can be obtained, and the transition to the next step of laying a sheet finishing material or a pasting floor material becomes possible after the next day to the third day.

The cured body surface of the leveling material mortar used in the present invention 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 40/1000. Particularly preferably, by having a gradient of more than 0/1000 and not more than -30/1000, it can be used for floor preparation with a gradient.

The expansion of the length change rate of the leveling material mortar cured body is preferably in the range of 0 to 0.08%, more preferably 0 to 0.06%, particularly preferably 0 to 0.05%. Leveling having a rate of shrinkage of preferably 0.08 to 0%, more preferably -0.06 to 0%, particularly preferably -0.05 to 0%, and having the aforementioned expansion or contraction characteristics The material is preferable because it can prevent generation of cracks in the cured body itself and can maintain a high adhesive force with the underlying concrete floor. Also, if the length change rate is out of the above range, cracks may occur due to the curing shrinkage of the cured body of leveling mortar, and the moisture separated from the underlying concrete floor may diffuse through the cracks. In the case where a sheet finishing material layer or the like is laid on the upper surface of the cured body of the leveling mortar, it is not preferable because swelling may occur.

On the upper surface of the mortar cured body of the leveling material used in the present invention, finishing layers such as various resin tiles and sheet finishing materials can be appropriately selected and used.

Hereinafter, the present invention will be described in detail based on examples. However, the present invention is not limited by the following examples.

(Characteristic evaluation method)
(1) Flowability evaluation of leveling material mortar:
・ Measurement method of flow value:
Measured according to JASS 15M-103. A plastic pipe (internal volume: 100 ml) having an inner diameter of 50 mm and a height of 51 mm is placed on a 5 mm thick sheet glass and filled with a kneaded leveling material mortar up to the upper end of the resin pipe. Pull up. After the spread of the mortar stopped, the diameters in two directions at right angles were measured, and the average value was taken as the flow value to evaluate the fluidity of the mortar.
-SL value measurement method:
The SL value is measured using the SL measuring instrument shown in FIG. 3, a rail having a width of 30 mm, a height of 30 mm and a length of 750 mm is provided with a weir plate at a length of 150 mm from the tip, and a predetermined amount of mortar immediately after kneading is satisfied And molded. Immediately after molding, the weir plate is pulled up, and after the mortar flow is stopped, the distance from the gauge point (weir plate installation part) to the shortest part of the mortar flow is measured, and the value (SL value) is set to L0. Further, the time for 200 mm flow was measured, and the measurement time was defined as the SL flow rate (L0) (second / 200 mm).

(2) Workability evaluation of leveling material mortar:
-Ironing workability when pouring mortar:
Under outdoor conditions, a 3 × solution of a primer for leveling material (300 g / m ² of water was added to a stock solution of 150 g / m ² ) was applied to the hardened concrete base in a 1 m × 0.5 m section and allowed to dry naturally. After the primer is formed, the leveling material mortar is poured so that the average construction thickness is 1 to 6 mm, and then the surface of the mortar is molded using a plasterer so that the gradient is 10/1000 (at 1000 mm span, The construction thickness was 1 mm and the maximum construction thickness was 11 mm), and the iron workability was evaluated.
As for the dredging workability, the looseness and cutability were evaluated, and the evaluation was made in four stages of excellent>good>good> impossible in the order of high evaluation.
・ Gradient formation:
After the mortar was cured, the gradient of the surface of the mortar cured body was measured to evaluate whether the gradient (10/1000) formed using the plasterer was maintained. The evaluation index is good when the gradient X is (9.5 ≦ X ≦ 10) / 1000, acceptable when the gradient X is (9 ≦ X <9.5) / 1000, and the gradient X is (X <9). / 1000 was not allowed.

(3) Evaluation of surface characteristics of leveling material mortar cured body:
・ Shore hardness measurement method:
After pouring and applying leveling material mortar, the hardened surface is pressed perpendicularly to any 6 locations using a spring type hardness tester type D type (manufactured by Ueshima Seisakusho) for a predetermined elapsed time. The average value of D-type gauge readings was taken as the Shore hardness at that time, and the surface hardness was evaluated.
・ Hair presser evaluation:
After pouring the leveling material mortar, the mortar surface finish is not leveled by the plasterer, it is cured to the semi-cured state as it is, and the surface finish is performed with the shore hardness of 1 to 20 in the semi-cured state. The condition was evaluated.
Evaluation of the surface finish by pressing with a heel presser evaluates the smoothness of the surface of the cured body at the age of 24 hours after further curing by visual and tactile sensation. The above four grades were evaluated, and a pass was determined to be acceptable.
-Hardened surface properties:
The properties of the surface of the cured mortar were evaluated by visually observing the presence or absence of wrinkles and bubbles after 24 hours at the age of the material after curing (when the Shore hardness can be measured). The crack was evaluated on the age of 28 days. The evaluation criteria are as follows.
○: None, ×: Present

(Materials used): The following materials were used.
1) Primer for leveling material: U primer G manufactured by Ube Industries, Ltd.
2) Leveling material: A leveling material in which the following raw materials were mixed at a blending ratio shown in Table 1 was used.
Alumina cement: Fondge, manufactured by Kerneos, Blaine specific surface area of 3100 cm ² / g.
Portland cement: Hayashi Cement, Ube Mitsubishi Cement Co., Blaine specific surface area 4500 cm ² / g.
Gypsum: Type ^II anhydrous gypsum, manufactured by Central Glass Co., Ltd., Blaine specific surface area of 3460 cm ² / g.
-Fine aggregate: Silica sand: No. 6 silica sand.
-Inorganic component: Blast furnace slag fine powder, rebirth, manufactured by Chiba Rebirth, Blaine specific surface area 4400 cm ² / g.
Resin A: Acrylic ester / methacrylic ester copolymer, a re-emulsified resin powder in which primary particles are coated with a water-soluble protective colloid of polyvinyl alcohol, manufactured by Nichigo Movinyl Co., Ltd., DM7000P.
Resin B: ethylene / vinyl acetate copolymer, re-emulsified resin powder, manufactured by Asahi Kasei Chemicals Corporation, RE5044N.
Resin C: Styrene / acrylic acid ester / methacrylic acid copolymer emulsion, U primer G manufactured by Ube Industries, Ltd.
-Setting retarder a: sodium bicarbonate, manufactured by Tosoh Corporation.
-Setting retarder b: L-sodium tartrate, manufactured by Fuso Chemical Industries.
-Setting accelerator a: Lithium carbonate, manufactured by Honjo Chemical Co., Ltd.
-Setting accelerator b: Aluminum sulfate, manufactured by Daimei Chemical Co., Ltd.
-Setting accelerator c: Sodium aluminate, manufactured by Hokuriku Kasei Co., Ltd.
-Fluidizer: Polycarboxylic acid fluidizer, manufactured by Kao Corporation.
-Thickener: Hydroxyethyl methylcellulose-based thickener, Marporose MX-30000, manufactured by Matsumoto Yushi Co., Ltd.
-Antifoaming agent: A polyether type antifoaming agent, manufactured by San Nopco.

(Preparation of mortar for leveling material)
The leveling material prepared in the conditions and the mixing ratio shown in Table 1 and water are mixed at a ratio of 25 parts by weight of water to 100 parts by weight of the leveling material, and kneaded for 3 minutes using a hand mixer with a rotation speed of 1100 rpm. Thus, a leveling material mortar was prepared.

[Example 1, Comparative Examples 1 to 4]
A leveling material mortar was prepared using a leveling material containing the components shown in Table 1. Table 2 shows the measurement results of mortar fluidity (flow value, SL value, mortar movement speed).

Table 2 shows the results of evaluating the trowel workability, gradient forming ability, shore hardness and cured body surface condition of the mortar.

(1) In the case of the leveling material of Comparative Example 1 in which no resin component was blended, good gradient forming property was not obtained, the surface finish state by the heel press was poor, and cracks occurred on the surface of the cured body.
(2) In the case of Example 1 using a re-emulsified resin powder of an acrylic ester / methacrylic ester copolymer as the resin component, the gradient forming property and the workability of the iron are good, and the surface finish by the wrinkle presser The state and the surface state of the cured body were also good.
In addition, as shown in Example 2 and Example 3, when the temperature is 21 ° C., good workability, gradient forming property, good surface finish state by wrinkle pressing, and excellent cured body even at 5 ° C. The surface condition could be obtained.
(3) In the case of Comparative Example 2 using a re-emulsified resin powder of ethylene / vinyl acetate copolymer as the resin component, although the iron workability is excellent, the formability of the gradient and the finish by the iron presser were implemented. Compared to Example 1, it was inferior. Further, wrinkles were generated on the surface of the cured body, and a smooth and good finished surface could not be obtained.
(4) In the case of Comparative Example 3 using a styrene / acrylic acid ester / methacrylic acid copolymer emulsion instead of a re-emulsifying resin powder as the resin component, the same characteristics as in Example 1 were obtained for workability. However, bubbles were observed on the surface of the cured body, and a smooth and good finished surface was not obtained.

The construction method of a concrete floor structure having a gradient according to the present invention includes a hydraulic component excellent in quick hardening and quick drying, and an acrylic ester / methacrylic ester in which primary particles are coated with a water-soluble protective colloid of polyvinyl alcohol. By using a leveling material containing a copolymer re-emulsified resin powder, it is possible to form a smooth floor surface having an appropriate mortar viscosity and thixotropic properties and having a gradient. It is possible to form a smooth and sloped floor by retouching with a heel presser in a semi-cured state, and it has excellent fast-curing and quick-drying properties, as well as low shrinkage and crack resistance. A concrete floor structure having a good surface finish and a gradient excellent in weather resistance can be obtained even if it is applied in (1).
In addition, the method for constructing a concrete floor structure having a gradient according to the present invention has an excellent effect as a method for repairing a concrete floor structure having a gradient, which smoothly repairs a defect portion or the like of the concrete floor structure having a gradient. It is to provide.

It is a schematic diagram which shows the outline | summary of a construction procedure about the construction method of the concrete floor structure which has the gradient of this invention. It is a schematic diagram at the time of forming the concrete floor structure which has a gradient using a self-leveling material. It is a schematic diagram which shows the outline which evaluates the leveling property of hydraulic mortar using SL measuring device.

Explanation of symbols

11: Concrete floor structure such as a balcony 12: Concrete floor surface 13: Non-smooth part such as a recess or a defect 14: Primer layer 15: Leveling material mortar (uncured state)
16: Semi-cured body of leveling material mortar 17: Cured body of leveling material mortar 18: Plasterer 19: Leveling material mortar (uncured state)
20: Hardened body of leveling material mortar 21: Non-flat portion generated by self-flow of self-leveling material slurry

Claims (9)

On the concrete floor top surface, a step of pouring a mortar prepared using a leveling material containing an acrylic copolymer-based re-emulsifying resin powder into a thickness of 0.5 to 30 mm, and the surface of the poured mortar using a trowel A method for constructing a concrete floor structure, comprising a step of leveling and a step of smoothing the surface of the mortar cured body by pressing the surface of the mortar cured body in a semi-cured state. The method for constructing a concrete floor structure according to claim 1, wherein the surface of the mortar cured body in a semi-cured state has a Shore hardness of 1 to 20. 3. The method for constructing a concrete floor structure according to claim 1, wherein the leveling material includes a hydraulic component made of alumina cement, Portland cement, and gypsum. The leveling material includes a hydraulic component and an acrylic copolymer-based re-emulsified resin powder, and further includes a component selected from an inorganic powder, a fine aggregate, a setting modifier, a fluidizing agent, a thickener, and an antifoaming agent. The construction method for a concrete floor structure according to any one of claims 1 to 3, comprising at least one or more kinds. The concrete according to any one of claims 1 to 4, wherein the acrylic copolymer re-emulsified resin powder is an acrylic ester / methacrylic ester copolymer re-emulsified resin powder. Construction method for floor structures. The acrylic copolymer-based re-emulsified resin powder is blended at a ratio of 1 to 50 parts by mass with respect to 100 parts by mass of the hydraulic component. Construction method for concrete floor structures. The shore hardness of the mortar hardened body surface using the leveling material is 1 or more after 4 hours after pouring and applying the mortar, The concrete floor structure according to any one of claims 1 to 6, Construction method. The concrete floor construction method according to any one of claims 1 to 7, wherein the concrete floor upper surface has a gradient of more than 0/1000 and not more than 50/1000. A concrete floor structure obtained by the method for constructing a concrete floor structure according to any one of claims 1 to 8, wherein an upper surface of the concrete floor structure has a gradient of more than 0/1000 and not more than 50/1000. .

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