JP2014015348A - Self-fluidity hydraulic composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a self-fluidity hydraulic composition having an excellent workability due to its high fluidity, a surface smoothness(flatness), a surface horizontality, a fast hardening property etc., in particular, having an excellent surface property that does not produce surface powdering or surface unevenness due to material separation or the water floating from the surface, while maintaining the high fluidity.SOLUTION: A self-fluidity hydraulic composition comprises: a hydraulic component; an inorganic powder; a fine aggregate; a fluidizer; a setting modifier; and a hydroxypropyl methylcellulose thickener. Here, the inorganic powder is one or more kinds selected from blast-furnace slag fine powder and limestone fine powder, and the hydroxypropyl methylcellulose thickener has a viscosity of at least 2,000 mPa s when measured as 2 mass% aqueous solution at 20°C and a viscosity measured as 1 mass% aqueous solution is at most 50,000 mPa s.

Description

  The present invention relates to a self-flowing hydraulic composition used for construction of a structure such as a concrete floor structure.

  A self-fluid slurry obtained by kneading a self-fluid hydraulic composition and water is required to have excellent workability due to high fluidity, surface smoothness (flatness), surface horizontality, and fast curing. The

  Self-flowing hydraulic compositions are roughly classified into a gypsum system and a cement system. As a cement composition that has rapid hardening, can be easily manufactured, and can be provided at low cost, Patent Document 1 contains a predetermined amount of fine slag powder, alumina cement, and anhydrous gypsum based on Portland cement, and further a setting controller. A fast-hardening cement composition to which a predetermined amount is added is disclosed.

  Further, as a self-leveling composition having excellent fluidity, Patent Document 2 includes a hydraulic component composed of alumina cement, Portland cement and gypsum, blast furnace slag, a water reducing agent and / or a thickening agent. A self-flowing hydraulic composition using a blast furnace slag having an average particle diameter within a predetermined range is disclosed.

Japanese Patent Publication No. 2-15507 JP 2008-30985 A

  However, if high fluidity is given to form a horizontal and smooth floor surface, surface pulverization (forms a thin powdery layer on the surface) or surface irregularities (fine surface on the surface) due to material separation or surface water floating. Unevenness may be formed).

  In the self-flowing hydraulic composition, the present invention has excellent workability due to high fluidity, surface smoothness (flatness), surface horizontality, fast-curing property, etc., and particularly high fluidity. An object of the present invention is to provide a self-flowing hydraulic composition having excellent surface characteristics that does not cause surface pulverization or surface unevenness due to material separation or surface water floating.

  In order to solve the above problems, the inventors have changed the hydraulic component and each raw material, and have studied in detail about the fluidity and the surface state. The present invention has been completed by finding that a water-soluble hydraulic composition can be obtained.

That is, the present invention is a self-flowing hydraulic composition comprising a hydraulic component, an inorganic powder, a fine aggregate, a fluidizing agent, a setting modifier, and a hydroxypropyl methylcellulose thickener,
The inorganic powder is at least one selected from blast furnace slag fine powder and limestone fine powder,
The hydroxypropyl methylcellulose thickener provides a self-flowing hydraulic composition in which the viscosity of a 2% by weight aqueous solution at 20 ° C. is 2000 mPa · s or more and the viscosity of a 1% by weight aqueous solution is 50000 mPa · s or less. To do.

  According to the self-flowing hydraulic composition of the present invention, it has excellent workability due to high fluidity, surface smoothness (flatness), surface horizontality, fast curing, etc., and particularly has high fluidity. On the other hand, it is possible to obtain excellent surface characteristics that do not cause surface pulverization or surface unevenness due to material separation or surface water floating.

  Preferred embodiments [(1) to (4)] of the self-flowing hydraulic composition of the present invention are shown below. In the present invention, it is preferable to appropriately combine these aspects.

  (1) In the self-flowing hydraulic composition of the present invention, the hydraulic component is preferably composed of 5-70% by mass of Portland cement, 20-80% by mass of alumina cement and 5-45% by mass of gypsum. Thereby, more excellent curing characteristics (fast curing, etc.) can be obtained.

  (2) In the self-flowing hydraulic composition of the present invention, the fine aggregate preferably has a coarse particle ratio of 0.60 to 1.40 and a water absorption of 1.6% or less. Thereby, the self-fluidity of the self-fluidic hydraulic composition can be further improved.

  (3) The self-fluid hydraulic composition of the present invention is 10 to 350 parts by mass of inorganic powder and preferably 85 to 325 parts by mass of fine aggregate with respect to 100 parts by mass of the hydraulic component. Thereby, more excellent fluidity and curing characteristics can be obtained.

  (4) The self-flowing hydraulic composition of the present invention is preferably 0.01 to 1.00 parts by mass of a hydroxypropyl methylcellulose thickener with respect to 100 parts by mass of the hydraulic component. Thereby, more excellent surface characteristics can be obtained.

  According to the present invention, it has excellent workability due to high fluidity, surface smoothness (flatness), surface horizontality, quick hardening, etc., and in particular, has high fluidity while separating materials and surface water. It is possible to provide a self-flowing hydraulic composition capable of obtaining excellent surface characteristics without causing surface powdering or surface unevenness due to floating.

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 graph which shows the relationship between SL flow time and SL value.

  A preferred embodiment of the self-flowing hydraulic composition of the present invention will be described below.

  The self-fluid hydraulic composition of this embodiment is a self-fluid hydraulic composition containing a hydraulic component, inorganic powder, fine aggregate, fluidizer, setting modifier, and hydroxypropyl methylcellulose thickener. .

  As the hydraulic component, it is preferable to use a hydraulic component made of Portland cement, alumina cement and gypsum. Thereby, the more excellent self-fluidity and the more excellent quick-hardness can be obtained.

  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.

Several types of alumina cement having different mineral compositions are known and commercially available, but their main component is monocalcium aluminate (CA), and commercially available products can be used regardless of the type. Especially, it is preferable to use the alumina cement which has a Blaine specific surface area of 4000-6000 cm < ² > / g. The brane specific surface area of the alumina cement is determined according to JIS R 2521: 1995.

  Examples of the gypsum include dihydrate gypsum, hemihydrate gypsum, and anhydrous gypsum, and any gypsum produced as a by-product in flue gas desulfurization or hydrofluoric acid production process or naturally produced gypsum can be used. it can. From the viewpoint of workability (high fluidity, long pot life), it is preferable to use anhydrous gypsum.

  In the present invention, as a hydraulic component, by using a hydraulic component consisting of Portland cement, alumina cement and gypsum, it has excellent self-fluidity, has an appropriate pot life, and excellent fast-curing property, A self-leveling material having a small volume change of the cured body can be obtained.

  The hydraulic component is preferably composed of 5-70% by weight of Portland cement, 20-80% by weight of alumina cement and 5-45% by weight of gypsum. Portland cement, alumina cement, and gypsum are within the above ranges, so that it is easy to obtain a cured product with low material cost, excellent self-fluidity, excellent rapid curing, and less volume change during curing. Become.

The blending ratio of the hydraulic component used in the self-flowing hydraulic composition of the present embodiment is as follows:
More preferably, Portland cement 5 to 70% by weight, alumina cement 20 to 80% by weight and gypsum 5 to 45% by weight,
More preferably, Portland cement 20 to 60% by mass, alumina cement 25 to 70% by mass and gypsum 10 to 40% by mass,
Particularly preferred are Portland cement 30 to 50% by mass, alumina cement 25 to 45% by mass and gypsum 20 to 30% by mass.

  The inorganic powder is preferably at least one selected from blast furnace slag fine powder and limestone fine powder defined in JIS A 6206 “Blast furnace slag fine powder for concrete”. 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. By using blast furnace slag fine powder and / or limestone fine powder as the inorganic powder, strength development and dimensional stability can be enhanced.

Further, these inorganic powders have a specific surface area of branes measured according to JIS R 5201 “Physical Test Method for Cement”.
Preferably it is 3000 cm ² / g or more,
More preferably, it is 3000-8000 cm < ² > / g,
More preferably, it is 3500-6000 cm ² / g,
Especially preferably, it is 4000-5000 cm < ² > / g.
When the brain specific surface area is in the above range, more excellent fluidity retention, strength development and dimensional stability can be obtained.

  As a hydroxypropyl methylcellulose thickener, the viscosity of a 2% by mass aqueous solution at 20 ° C. measured with a B-type viscometer is 2000 mPa · s or more, and the viscosity of a 1% by mass aqueous solution is 50000 mPa · s or less. Thereby, surface smoothness (flatness) and surface levelness can be obtained while having excellent workability due to high fluidity. In particular, excellent surface characteristics can be obtained that have high fluidity and do not cause surface powdering or surface irregularities due to material separation or surface water floating.

The viscosity at 20 ° C. of the hydroxypropyl methylcellulose thickener is
Preferably, it is 3000 mPa · s or more with a 2% aqueous solution and 30000 mPa · s or less with a 1% aqueous solution,
More preferably, it is 10000 mPa · s or more in a 2% aqueous solution and 25000 mPa · s or less in a 1% aqueous solution,
More preferably, it is 20000 mPa · s or more in a 2% aqueous solution and 22000 mPa · s or less in a 1% aqueous solution,
Particularly preferably, it is 16000 to 21000 mPa · s in a 1% aqueous solution.

  The viscosity of the hydroxypropylmethylcellulose thickener is obtained by measuring an aqueous solution (20 ° C.) containing 1% by mass of hydroxypropylmethylcellulose thickener or an aqueous solution (20 ° C.) containing 2% by mass using a B-type viscometer. be able to.

The hydroxypropyl methylcellulose thickener is obtained by substituting a part of three hydroxyl groups on 1,4-bonded D-glucopyranose with a methoxyl group and a hydroxypropoxyl group. The average number of hydroxyl groups substituted with methoxyl groups per D-glucopyranose unit is defined as the substitution degree DS of methoxyl groups, and the average added moles of substituted hydroxypropoxyl groups per D-glucopyranose unit. When the number is defined as the molar substitution degree MS of the hydroxypropoxyl group,
The substitution degree DS of the methoxyl group is preferably 1.0 or more and less than 1.6. Moreover, the molar substitution degree MS of the hydroxypropoxyl group is preferably 0.05 to 1.00. Thereby, surface smoothness (flatness) and surface levelness can be obtained while having excellent workability due to high fluidity. In particular, excellent surface characteristics can be obtained that have high fluidity and do not cause surface powdering or surface irregularities due to material separation or surface water floating.

As the substitution degree DS of the methoxyl group,
More preferably 1.10 to 1.59,
More preferably 1.30 to 1.57,
Particularly preferred is 1.48 to 1.54.
In addition, as the molar substitution degree MS of the hydroxypropoxyl group,
More preferably, it is 0.10 to 0.50,
More preferably, it is 0.13-0.30,
Especially preferably, it is 0.15-0.21.

  The degree of substitution DS and the degree of molar substitution MS are described in J. G. Gobler, E .; P. Samsel and G.M. H. It can be measured according to Zeisel-GC described in Beaver, Talanta, 9, 474 (1962).

  In the self-flowing composition of this embodiment, it is preferable that it is 0.01-1.00 mass part of hydroxypropyl methylcellulose thickeners with respect to 100 mass parts of hydraulic components. Thereby, surface smoothness (flatness) and surface levelness can be obtained while having excellent workability due to high fluidity. In particular, excellent surface characteristics can be obtained that have high fluidity and do not cause surface powdering or surface irregularities due to material separation or surface water floating.

The hydroxypropyl methylcellulose thickener used in the self-flowing hydraulic composition of the present embodiment is based on 100 parts by mass of the hydraulic component.
More preferably 0.05 to 0.75 parts by mass,
More preferably 0.09 to 0.50 parts by mass,
Particularly preferably, 0.12 to 0.30 parts by mass can be blended.

  The fine aggregate has a maximum particle size of 850 μm or less, and preferably contains less than 5 mass% of coarse particles having a particle diameter of more than 600 μm in 100 mass% of the fine aggregate. Such fine aggregates can be appropriately selected from sands such as quartz sand, river sand, land sand, sea sand, crushed sand, slag fine aggregate, regenerated fine aggregate, and alumina clinker. In particular, as the fine aggregate, those selected from sands such as quartz sand, river sand, land sand, sea sand and crushed sand, and alumina clinker can be suitably used.

  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 the present invention, the term “coarse fraction having a particle diameter of more than 600 μm” refers to the mass ratio of particles on the sieve residue when a 600 μm sieve is used.

If the fine aggregate contains 5% by mass or more of coarse particles having a particle diameter of more than 600 μm, the self-fluidity of the self-leveling material tends to be reduced. The lower limit of the coarse particles is not particularly limited, and may be 0% by mass. In order to obtain excellent self-fluidity, the coarse particles in the fine aggregate
More preferably, it is 0 to 3% by mass.
More preferably, it is 0-0.5 mass%,
Especially preferably, it is 0-0.15 mass%.

  In the self-flowing composition of the present embodiment, it is preferable that the coarse aggregate ratio of the fine aggregate is in the range of 0.60 to 1.40 and the water absorption is 1.6% or less. Thereby, more excellent self-fluidity can be obtained.

  Here, the “rough grain ratio” refers to the coarse grain ratio of the aggregate as defined in JIS A 1102: 2006. Further, the “water absorption rate” refers to a value measured according to the method for measuring the water absorption rate (unit:%) of an aggregate defined in JIS A 1109: 2006.

As the coarse particle ratio of fine aggregate,
More preferably, it is 0.68-1.35,
More preferably, it is 0.72-1.28,
Especially preferably, it is 0.74-1.25.
Further, the lower limit value of the water absorption rate is not particularly limited, and may be 0%. The water absorption rate of fine bone agent is
More preferably 1.40% or less,
More preferably, it is 1.20% or less,
Particularly preferably, it is 1.00% or less.

  In the self-flowing composition of the present embodiment, the inorganic powder is 10 to 350 parts by mass and the fine aggregate 85 to 325 parts by mass with respect to 100 parts by mass of the hydraulic component. Thereby, workability | operativity and hardening characteristics can be improved more.

The inorganic powder used in the self-flowing hydraulic composition of the present embodiment is based on 100 parts by mass of the hydraulic component.
More preferably 30 to 275 parts by mass,
More preferably, 50 to 200 parts by mass,
Particularly preferably, 80 to 120 parts by mass can be blended.

The fine aggregate used in the self-flowing hydraulic composition of the present embodiment is 100 parts by mass of the hydraulic component,
More preferably, 120 to 285 parts by mass,
More preferably, 155 to 245 parts by mass,
Particularly preferably, 180 to 220 parts by mass can be blended.

  The self-flowing hydraulic composition of the present embodiment is usually used with a small amount of mixing water in order to obtain a high-strength cured body while suppressing material separation. Accordingly, in the self-fluid hydraulic composition of the present invention, a fluidizing agent having a water reducing effect is an essential component in order to ensure high fluidity even if the water / hydraulic component ratio is small.

  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 used in the self-flowing hydraulic composition of the present embodiment can be appropriately added in a range that does not impair the characteristics, depending on the hydraulic component used, and is based on 100 parts by mass of the hydraulic component. ,
Preferably 0.01 to 2.0 parts by weight,
More preferably 0.02-1.0 parts by mass,
More preferably 0.05 to 0.50 parts by mass,
Particularly preferably, 0.08 to 0.30 parts by mass can be blended.
If the addition amount of the fluidizing agent is too small, a suitable effect (excellent fluidity and high cured body strength) will not be exhibited, and if the addition amount is too large, an effect commensurate with the addition amount cannot be expected, and it is simply ineffective. Not only is it economical, but in some cases the viscosity becomes large and the amount of kneading water for obtaining the required fluidity increases, which may deteriorate the strength properties.

  The self-flowing hydraulic composition of the present embodiment contains a setting regulator as an essential component in order to adjust the pot life (flow retention) and fast curing. The setting modifier includes a setting accelerator that accelerates the hydration reaction of the hydraulic component and a setting retarder that delays the hydration reaction of the hydraulic component. Depending on the combination of the hydraulic component used, The addition amount is appropriately selected.

  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 used in the self-flowing hydraulic composition of the present embodiment is based on 100 parts by mass of the hydraulic component.
Preferably 0.01 to 2.0 parts by weight,
More preferably 0.05 to 1.5 parts by mass,
More preferably 0.08-1.2 parts by mass,
The pot life (handling time) with which suitable fluidity | liquidity is acquired can be ensured by using especially preferably in the range of 0.10-1.0 mass part. Furthermore, by adjusting the addition amount of the setting retarder to the above-mentioned preferable range, it has self-fluidity (self-leveling property), and self-fluidity that has a pot life (handling time) that can obtain suitable fluidity. A hydraulic slurry can be obtained.

  As the setting accelerator, 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 characteristics of the self-flowing hydraulic composition 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 used in the self-flowing hydraulic composition of the present embodiment is based on 100 parts by mass of the hydraulic component.
Preferably 0.01 to 1.0 parts by weight,
More preferably, 0.01 to 0.5 parts by mass,
More preferably 0.02-0.2 parts by mass,
It is particularly preferable to use it in the range of 0.03 to 0.1 parts by mass, since suitable fast curing can be obtained after securing the pot life of the self-flowing hydraulic composition. Self-flowing water that has self-fluidity (self-leveling properties) by adjusting the addition amount of the setting accelerator within the above preferred range, and that exhibits good pot life, and then exhibits suitable quick hardening A hard slurry can be obtained.

  In addition to the above essential components, an antifoaming agent and the like can be appropriately added to the self-flowing hydraulic composition of the present invention as long as the characteristics of the present invention are not impaired.

  Examples of the antifoaming agent include known substances such as synthetic substances such as silicone-based, alcohol-based and / or polyether-based substances and / or plant-derived natural substances. Among these, polyether antifoaming agents are preferable from the viewpoints of price and availability. By using an antifoaming agent, it can be expected that the antifoaming effect of the self-flowing hydraulic composition is improved.

  The self-flowing hydraulic composition of the present invention has excellent workability due to high fluidity, surface smoothness (flatness), surface horizontality, fast-curing property, etc., in particular, while having high fluidity, Because it has excellent surface properties that do not cause surface pulverization or surface unevenness due to material separation or surface water floating, it has excellent surface properties, so it is a school, condominium, convenience store, hospital, veranda, factory, warehouse, indoor parking lot, gas station and kitchen It can be used for floor foundations and floor finishing materials.

  A self-flowing hydraulic slurry can be produced by mixing and stirring the self-flowing hydraulic composition of the present embodiment with a predetermined amount of water. By adjusting the amount of water added, the fluidity, material separability, and curing characteristics of the self-flowing hydraulic slurry can be adjusted.

The self-flowing hydraulic slurry has a mass ratio (W / S) between water (W) and the self-flowing hydraulic composition (S).
Preferably 0.22 to 0.30,
More preferably 0.23 to 0.29,
More preferably 0.24 to 0.28,
It can mix | blend and knead | mix so that it may become the range of 0.25-0.27 especially preferably.

From the viewpoint of the fluidity of the self-fluid hydraulic slurry, the flow value of the self-fluid hydraulic slurry is
Preferably it is 200 mm to 260 mm,
More preferably, it is 210 mm-255 mm,
More preferably, it is 220-250 mm,
Especially preferably, it is 230-245 mm.
When the flow value is in the above range, the fluidity is suitable, and the surface of the cured body having high smoothness and horizontality tends to be obtained.

  Moreover, the self-leveling property of the self-flowing hydraulic slurry can be evaluated using the SL measuring device shown in FIG.

  FIG. 1 is a perspective view schematically showing an SL measuring instrument used for self-flowing hydraulic slurry self-leveling evaluation. The SL measuring instrument 10 is made of synthetic resin and has an internal dimension of 30 mm width × 30 mm height. X It has a bowl shape with a length of 750 mm, and only one end is an open end. And the SL measuring device 10 dams the filling part 11 for filling the self-flowing hydraulic slurry on the closed end side, and the self-flowing hydraulic slurry to be filled adjacent to the filling part 11. The filling section 11 has a capacity of 30 mm width × 30 mm height × 150 mm length.

  FIG. 2 is a cross-sectional view schematically showing a method for evaluating the self-leveling property of a self-fluid hydraulic slurry using the above-described SL measuring device. First, as shown in FIG. 2A, the self-flowing hydraulic slurry immediately after kneading is poured so as to fill the filling portion 11. Next, by pulling up the weir plate 12, as shown in FIG. 2B, the poured self-fluid hydraulic slurry flows out toward the opening end side of the SL measuring device 10.

  The time required for the self-fluid hydraulic slurry that has flowed out to flow a distance of 200 mm from the mark 13 is the SL flow time (seconds), and from the mark 13 to the end point 14 where the flow of the self-fluid hydraulic slurry has stopped. Is the SL value (mm). By measuring the SL flow time and SL value, the self-leveling property of the self-flowing hydraulic slurry can be evaluated.

Immediately after the self-fluid hydraulic slurry is poured into the filling part 11, the weir plate 12 is pulled up, and the flow time during which the self-fluid hydraulic slurry flows through a distance of 200 mm is in an environment at a temperature of 20 ° C.
Preferably it is 3 to 35 seconds,
More preferably 5 to 25 seconds,
More preferably, it is 8-20 seconds,
Especially preferably, it is 10 to 15 seconds.

The SL value of the self-flowing hydraulic slurry is 20 ° C. in an environment,
Preferably it is 400-600mm,
More preferably, it is 450-580 mm,
More preferably, it is 480-560 mm,
Especially preferably, it is 500-550 mm.

  Self-fluid hydraulic slurry begins to harden between 50 minutes and 2 hours after pouring, depending on the temperature and humidity conditions at the construction site (water pulling: disappearance of surface water of self-fluid hydraulic slurry) ), The surface hardness of the self-fluid hydraulic slurry cured body increases with the progress of curing, and the moisture content on the surface of the cured body tends to decrease.

The shore hardness of the surface of the cured body after 2 hours formed by casting a self-fluid hydraulic slurry and finishing the surface of the self-fluid hydraulic slurry under an environment of a temperature of 20 ° C.
Preferably it is 1 or more,
More preferably 10 or more,
More preferably, it is 20 or more,
Especially preferably, it is 30 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 self-flowing hydraulic slurry is within the above range, the concrete floor structure is formed by the rapid hardening after the self-flowing hydraulic slurry construction (placement and finishing) is completed. It becomes easier to form the body in a short time.

  The surface on which the self-flowing hydraulic slurry is cured is required to have horizontality and smoothness (flatness). In particular, surface pulverization (a powdery thin layer is formed on the surface) and surface irregularities (fine irregularities on the surface) that cause a decrease in adhesiveness when constructing a stretch or painted floor on the cured body surface It is necessary that the It is preferable that the surface of the cured body is visually or touched with a finger so that the powder does not adhere to the finger or the finger does not feel unevenness.

  The contents of the present invention will be specifically described below 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 Portland cement [PC] (early strength Portland cement, manufactured by Ube Mitsubishi Cement Co., Ltd., Blaine specific surface area 4500 cm ² / g)
Alumina cement [AC] (Fonju, Kerneos, Blaine specific surface area 3100 cm ² / g)
Gypsum [GG] (Natural anhydrous gypsum, Blaine specific surface area 3880 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 (Reverment, manufactured by Chiba Riverment Co., Blaine specific surface area 4400 cm ² / g)
(3) Fine aggregate Silica sand (coarse fraction having a particle diameter of more than 600 μm = 0.12 mass%, coarse grain ratio = 1.20%, water absorption = 0.79%)
(4) Fluidizing agent Polycarboxylic acid based fluidizing agent (Kao Corporation)
(5) Setting adjuster Setting retarder A: Na tartrate (manufactured by Fuso Chemical Co., Ltd.)
Setting retarder B: Na bicarbonate (manufactured by Tosoh Corporation)
Setting accelerator: Lithium carbonate (particle size 3.5 μm, manufactured by Honjo Chemical Co., Ltd.)

(6) Thickener The thickener (made by Matsumoto Yushi Co., Ltd.) used in Table 2 is shown.

  The substitution degree DS and molar substitution degree MS of the thickener are described in J. Org. G. Gobler, E .; P. Samsel and G.M. H. The measurement was performed according to Zeisel-GC described in Beber, Talanta, 9, 474 (1962).

  The viscosity of the thickener was measured using a B-type viscometer (Digital Viscometer manufactured by Tokyo Keiki Co., Ltd .: DVL-B), and for each of the aqueous solutions (20 ° C.) containing 1% by mass and 2% by mass of the thickener, rotor No. 4. Measurement was performed under conditions (condition 1) at a rotor rotational speed of 12 rpm. About 2 mass% aqueous solution of the thickener A, since it exceeded the upper limit 50000 mPa * s, it was not measurable. Moreover, about the 1 mass% aqueous solution of the thickener C, and the thickener D, since it was not able to measure on the conditions 1, it measured on the measurement conditions of Table 2.

  The blending ratios of the above materials for obtaining a self-flowing hydraulic composition were as shown in Table 3.

[Preparation of self-fluid hydraulic slurry]
The above materials (total amount: 1.5 kg) were mixed at a blending ratio shown in Table 2 to prepare a self-flowing hydraulic composition. Next, 390 g of water was added to the obtained self-flowing hydraulic composition and kneaded for 3 minutes using a chemistor to obtain a self-flowing hydraulic slurry. The self-flowing hydraulic slurry was prepared in a thermostatic chamber 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. Table 4 shows the measurement results.

[Self-leveling (SL) value]
The self-flowing hydraulic slurry immediately after kneading into the filling part 11 of the SL measuring device 10 shown in FIG. 1 is pulled up immediately after pouring, and the self-flow flowing out from the filling part 11 as shown in FIG. After the flow of the water-based hydraulic slurry stopped, the distance from the reference point (dam plate installation portion) 13 to the end point 14 where the flow of the self-flowing hydraulic slurry stopped was measured as the SL value (mm). The SL flow time (second / 200 mm) required for the self-flowing hydraulic slurry to flow a distance of 200 mm from the mark 13 was measured. Table 4 shows the measurement results.

[Watering time]
The prepared self-flowing hydraulic slurry was poured 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 time when disappearance of light (the state where the reflection of light was lost and clouded) was measured as watering time. Table 4 shows the measurement results.

[surface hardness]
After a predetermined elapsed time from the placement of the self-flowing hydraulic slurry, the hardness of the hardened surface (Shore hardness) is changed to any 4 using a spring type hardness tester type D type (manufactured by Ueshima Seisakusho Co., Ltd.). The surface hardness of the place was measured, and the average value of the reading values of the spring type hardness tester type D gauge was defined as the surface hardness at that time. In the present examples and comparative examples, the Shore hardness after 1, 2 and 24 hours was measured. Table 4 shows the measurement results.

[Surface condition]
The surface state was determined by pouring the obtained self-flowing hydraulic slurry into a synthetic resin container having internal dimensions of width 130 × length 190 × height 17 mm to a thickness of 15 mm. Was touched to evaluate the pulverization and unevenness of the surface. Here, the “unevenness” is a bump that is present on the surface and has a width of several mm to several tens of mm and a thickness of several mm. “Powdering” is a state in which white powder is deposited on the surface, or a state in which the surface layer portion becomes powdery when lightly rubbed with a finger. Evaluation of pulverization is `` X '' when the precipitation of the powder is visually confirmed or when the surface becomes powdery when rubbed with a finger, `` ○ '' when the surface becomes powdery when rubbed strongly with a finger, A case where the surface did not become powdery even when rubbed strongly with a finger was indicated as “◎”. In the evaluation of unevenness, if the presence or absence of surface unevenness can be visually confirmed, or if it is not sufficiently visually confirmed by touching with a finger, it is indicated as `` X '', and if it is slightly visible by touching with a finger, it is indicated as `` ○ ''. The case where it was not understood even when touched with a finger was indicated as “「 ”. The measurement was performed in an environment with a temperature of 20 ° C. and a humidity of 65%. The evaluation results are shown in Table 4.

  As shown in Examples 1 to 3, the self-flowing hydraulic slurry prepared using the self-flowing hydraulic composition of the present invention exhibited excellent flow value and SL value (flowability). In particular, even when the SL value showed excellent fluidity of 595 mm, the surface state (powdering and unevenness) was good. Further, the watering time was about 1 hour, the Shore hardness was 30 or more in 2 hours, and excellent curing characteristics (fast curing) were obtained.

  On the other hand, as shown in FIG. 3 in which the relationship between the SL flow time and the SL value in Table 2 is represented by a graph, Comparative Example 1 and Comparative Example 2 have SL values in the same SL flow time compared to Examples 1-3. , Showed a tendency to lower. If the SL flow time is shortened in order to increase the SL value for the purpose of obtaining excellent fluidity, the surface condition may be poor due to material separation, or the thickness of the self-flowing hydraulic slurry during construction may be difficult to obtain. Therefore, if it is the same SL flow time, the Examples 1-3 with a high SL value have the outstanding fluidity | liquidity. Further, in Comparative Example 1, irregularities were generated on the surface of the cured body when the SL value was 595 mm, and in Comparative Example 2, pulverization occurred on the surface of the cured body when the SL value was 595 mm.

  From Examples 1 to 3 of the present invention, by including a hydraulic component, inorganic powder, fine aggregate, fluidizing agent, setting modifier, and hydroxypropyl methylcellulose thickener having a specific viscosity, due to high fluidity Has excellent workability, surface smoothness (flatness), surface horizontality, fast curing, etc. Especially, while having high fluidity, surface pulverization and surface irregularities occur due to material separation and surface water floating It was confirmed that a self-flowing hydraulic composition having excellent surface characteristics can be obtained.

  DESCRIPTION OF SYMBOLS 10 ... SL measuring device, 11 ... Filling part, 12 ... Barrage board, 13 ... Marking point, 14 ... End point.

Claims (5)

A self-flowing hydraulic composition comprising a hydraulic component, an inorganic powder, a fine aggregate, a fluidizing agent, a setting modifier, and a hydroxypropyl methylcellulose thickener,
The inorganic powder is at least one selected from blast furnace slag fine powder and limestone fine powder,
The hydroxypropyl methylcellulose thickener is a self-flowing hydraulic composition in which the viscosity of a 2% by mass aqueous solution at 20 ° C. is 2000 mPa · s or more and the viscosity of a 1% by mass aqueous solution is 50000 mPa · s or less.   The self-hydraulic hydraulic composition according to claim 1, wherein the hydraulic component comprises 5-70% by mass of Portland cement, 20-80% by mass of alumina cement, and 5-45% by mass of gypsum.   The self-flowing hydraulic composition according to claim 1 or 2, wherein the fine aggregate has a coarse particle ratio in the range of 0.60 to 1.40 and a water absorption of 1.6% or less. .   The self-flow according to any one of claims 1 to 3, wherein the inorganic powder is 10 to 350 parts by mass and the fine aggregate is 85 to 325 parts by mass with respect to 100 parts by mass of the hydraulic component. Hydraulic composition.   The self-flowing hydraulic composition according to any one of claims 1 to 4, wherein the hydroxypropyl methylcellulose thickener is 0.01 to 1.00 parts by mass with respect to 100 parts by mass of the hydraulic component. .

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