JP5217538B2 - Hydraulic composition and concrete floor structure using the same - Google Patents

Description

  The present invention relates to a hydraulic composition having self-fluidity and a concrete floor structure using the same, which can be used mainly for floor foundation adjustment of general buildings.

  When constructing a concrete structure using a hydraulic composition composed of various cements, the construction temperature, which is one of the construction conditions, is a characteristic of mortar and slurry (hydraulic slurry) using the hydraulic composition. Therefore, various studies have been conducted to reduce the impact. The characteristics of the mortar and slurry using the hydraulic composition may be affected by the content ratio of the trace components of the constituent material and the content ratio of the constituent components.

  As a method for producing a self-fluid hydraulic composition in which the fluidity of the slurry does not vary between production lots of hydraulic components, the fluidity is stable, and the product yield during production is improved, Patent Document 1 describes: Self-fluidity prepared by measuring the amount of free calcium oxide contained in Portland cement and mixing a hydraulic component containing Portland cement with a free calcium oxide amount of 1% by mass or less and a water reducing agent and / or thickener. A method for producing a hydraulic composition is disclosed.

  Further, Patent Document 2 includes a hydraulic component containing alumina cement and Portland cement, and a self-flowing hydraulic composition characterized by containing a water reducing agent and / or a thickening agent. A self-flowing hydraulic composition using alumina cement in which the amount of aluminum oxide (X) and the amount of calcium oxide (Y) satisfy (X / Y) ≧ 1.05 is disclosed.

JP 2006-168999 A JP 2006-240899 A

  The present invention can stably maintain a high fluidity for a long time even when the temperature condition during construction changes, and can stably obtain a cured body having excellent fast-curing property and horizontal level property and having a good finished surface. An object of the present invention is to provide a hydraulic composition for obtaining a hydraulic slurry.

  The present inventors have intensively studied the influence of temperature conditions, which is one of the construction conditions, on the properties of mortar and slurry using a hydraulic composition, and particularly included in the hydraulic component which is the main component. The present invention was completed by clarifying the influence of the content of trace components.

  That is, the first of the present invention is a hydraulic composition containing a hydraulic component containing a cement component and gypsum and a fine aggregate, wherein the gypsum uses calcium carbonate as a desulfurization neutralizer. Is a hydraulic composition that is a by-product of gypsum and does not contain calcium hydroxide.

The preferable aspect of the hydraulic composition of this invention is shown below. In the present invention, these embodiments can be appropriately combined.
(1) The hydraulic composition further includes a fluidizing agent.
(2) The gypsum has a pH of 5.5 to 7.5.
(3) The cement component is made of alumina cement and / or Portland cement.
(4) The hydraulic component is composed of 20 to 80% by mass of alumina cement, 5 to 70% by mass of Portland cement, and 5 to 45% by mass of gypsum, where the total of the hydraulic components is 100% by mass.
(5) The hydraulic composition includes a hydraulic component made of alumina cement, Portland cement, and gypsum, a fine aggregate, and a fluidizing agent. The hydraulic composition includes an inorganic component, a setting retarder, and a setting accelerator. A hydraulic slurry further comprising at least one component selected from an agent, a thickener and an antifoaming agent and prepared by kneading the hydraulic composition and water has self-fluidity.
(6) The shore hardness of the surface of the cured body of the hydraulic slurry prepared by kneading the hydraulic composition and water is 30 or more after 3 hours from the construction of the hydraulic slurry.

  Moreover, the 2nd of this invention is a concrete floor structure which has the hardening body layer of the hydraulic slurry using said hydraulic composition in a surface layer.

  The hydraulic slurry using the hydraulic composition of the present invention can stably maintain high fluidity for a long time even when the temperature condition during construction changes, and therefore, good handling properties can be obtained. It is excellent in hardness and horizontal level property, and a cured product having a good finished surface can be obtained stably.

  The present invention is a hydraulic composition containing a hydraulic component including a cement component and gypsum and a fine aggregate. The hydraulic composition of the present invention is a gypsum produced as a by-product in the hydrofluoric acid production process in which gypsum, which is an essential component, uses calcium carbonate as a desulfurization neutralizer. Therefore, the gypsum used for the hydraulic composition of the present invention does not contain calcium hydroxide.

  In general, in the process of producing hydrofluoric acid, gypsum may be produced as a by-product using slaked lime (calcium hydroxide) or quick lime (calcium oxide) as a desulfurization neutralizing material. When slaked lime or quick lime is used as a desulfurization neutralizing material, it is necessary to sufficiently advance the desulfurization reaction, so it is necessary to add excessive slaked lime or quick lime. May contain calcium oxide. If the calcium hydroxide content contained in gypsum fluctuates, the pH of the gypsum fluctuates, so the fluidity of a hydraulic composition prepared using gypsum containing calcium hydroxide is not stable and is not preferred.

  On the other hand, the gypsum used in the present invention is gypsum produced as a by-product using calcium carbonate as a desulfurization neutralizing material in the hydrofluoric acid production process. Even when calcium carbonate is used as a desulfurization neutralizer, it is necessary to add calcium carbonate excessively in order to sufficiently advance the desulfurization reaction. However, since calcium carbonate does not affect the pH of gypsum, even if the unreacted calcium carbonate content contained in gypsum fluctuates, it does not affect the pH of gypsum. Therefore, the hydraulic slurry made from the hydraulic composition prepared by using gypsum not containing calcium hydroxide, which is by-produced in the hydrofluoric acid production process using calcium carbonate as a desulfurization neutralizer, is very stable. A fluid property can be obtained.

In the present specification, the “desulfurization neutralizing material” means that hydrofluoric acid (CaF ₂ ) and sulfuric acid (H ₂ SO ₄ ) are reacted in the hydrofluoric acid production process to produce hydrofluoric acid (HF) and gypsum ( This refers to a “neutralizing material” added to neutralize the excessively added sulfuric acid residue after the formation of CaSO ₄ ). The present invention will be described in detail below.

<Hydraulic component>
The hydraulic component contained in the hydraulic composition of the present invention includes a cement component and gypsum. As the cement component, alumina cement and / or Portland cement can be used. In the hydraulic composition of the present invention, by using these components, it is possible to obtain a hydraulic composition having excellent self-fluidity, having an appropriate pot life and excellent quick hardening. preferable.

  The composition of the hydraulic component is preferably 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 when the total mass of alumina cement, Portland cement and gypsum is 100 parts by mass. It is. Moreover, the composition of a hydraulic component makes a total mass into 100 mass parts, More preferably, they are 30-70 mass parts of alumina cement, 15-60 mass parts of Portland cement, and 10-40 mass parts of gypsum. In addition, the composition of the hydraulic component is a composition comprising a total mass of 100 parts by mass, more preferably 35 to 60 parts by mass of alumina cement, 20 to 50 parts by mass of Portland cement, and 15 to 35 parts by mass of gypsum. Further, the composition of the hydraulic component is particularly preferably 40 to 50 parts by mass of alumina cement, 25 to 40 parts by mass of Portland cement and 17 to 27 parts by mass of gypsum with a total mass of 100 parts by mass. By using a hydraulic composition having such a composition, a hydraulic slurry having excellent self-fluidity can be obtained, and further, it has fast curing, low shrinkage or low expansion, and little volume change during curing. It is preferable because a cured product can be easily obtained.

<Cement component>
When the hydraulic composition of the present invention includes Portland cement as a cement component, the Portland cement is, for example, ordinary Portland cement, early-strength Portland cement, ultra-high-strength Portland cement, moderately hot Portland cement, low heat Portland cement, and white Portland cement. Portland cement can be used. Further, as the cement component of the hydraulic composition of the present invention, a mixed cement obtained by mixing Portland cement and other components, for example, a mixed cement such as blast furnace cement, fly ash cement, silica cement, and silica fume cement is used. it can.

  When the hydraulic composition of the present invention contains alumina cement as a cement component, the alumina cement can be used regardless of the type. Several types of alumina cements with 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. .

<Gypsum>
In the present invention, gypsum is used as one of the hydraulic components. Gypsum functions as a component that retains dimensional stability after the hydraulic slurry obtained by kneading the hydraulic composition and water is cured.

  In the hydraulic composition of the present invention, gypsum produced as a by-product in the hydrofluoric acid production process can be used, and gypsum produced as a by-product in the hydrofluoric acid production process using calcium carbonate as a desulfurization neutralizer. Anhydrous gypsum produced as a by-product using calcium carbonate as a desulfurization neutralizing agent in the hydrofluoric acid production process can be particularly preferably used. The hydraulic composition of the present invention does not use gypsum produced using slaked lime (calcium hydroxide) or quick lime (calcium oxide) as a desulfurization neutralizing material. Therefore, in the hydraulic composition of the present invention, the calcium hydroxide content in gypsum can be made substantially zero by using only gypsum produced using calcium carbonate as a desulfurization neutralizing material. That is, since the gypsum used for the hydraulic composition of the present invention does not contain calcium hydroxide, the pH of the gypsum is stable. Therefore, the hydraulic slurry using the hydraulic composition of the present invention prepared using such gypsum can stably maintain high fluidity for a long time even when the temperature condition during construction changes.

  The pH of gypsum produced using calcium carbonate as a desulfurization neutralizing material used in the hydraulic composition of the present invention is preferably in the range of pH 5.5 to pH 7.5, more preferably in the range of pH 6 to pH 7, particularly preferably. Can be preferably used in the range of pH 6.2 to pH 6.8. When the pH of gypsum produced using calcium carbonate as the desulfurization neutralizer exceeds the above range, the fluidity retention time of the hydraulic slurry using the hydraulic composition is 25 ° C. or higher, particularly 30. Since the fluidity retention time is shortened and the pot life is shortened under a temperature condition of ℃ or higher, the workability at the time of construction may be reduced. In the present specification, the “pH” of gypsum indicates a pH value obtained by measuring the pH of a slurry in which 10 g of gypsum is dispersed in 1 liter of pure water.

<Fine aggregate>
The hydraulic composition of the present invention includes fine aggregate in addition to the hydraulic component. The amount of fine aggregate contained in the hydraulic composition of the present invention is preferably 30 to 500 parts by mass, more preferably 50 to 400 parts by mass, and still more preferably 100 to 300 parts per 100 parts by mass of the hydraulic component. Part by mass, particularly preferably in the range of 150 to 250 parts by mass 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 to use an aggregate of 0.6 mm as a main component. The particle size of the fine aggregate can be measured by a method using several sieves with different nominal dimensions as defined in JIS Z-8801.

  Fine aggregates include silica sand, river sand, sea sand, mountain sand and crushed sand, alumina cement clinker, silica powder, clay minerals, waste FCC catalyst and inorganic materials such as limestone, urethane crushed, EVA foam and firing A resin pulverized product such as a resin can be used. In particular, as fine aggregates, sands such as quartz sand, river sand, sea sand, mountain sand and crushed sand, waste FCC catalyst, quartz powder, limestone sand and alumina cement clinker can be preferably used.

<Fluidizer>
The hydraulic composition of the present invention preferably contains a fluidizing agent (a water reducing agent such as a high performance water reducing agent) in order to ensure suitable fluidity while suppressing material separation. The expression strength of the alumina cement, which is a hydraulic component, is greatly affected by the water / hydraulic component ratio. Therefore, when alumina cement is included as the hydraulic component of the hydraulic composition of the present invention, it has a water reducing effect. It is particularly preferred to use a fluidizing agent to reduce the water / hydraulic component ratio.

  As a fluidizing agent, a fluidizing agent such as a polyether polycarboxylic acid, such as a formaldehyde condensate of melamine sulfonic acid, casein, casein calcium, and polyether, which has a water reducing effect, can be used regardless of the type. These commercially available products can be used. Particularly preferred are fluidizing agents such as polyether-based and polyether polycarboxylic acid, and these commercially available products can be used.

  The fluidizing agent can be appropriately added within a range that does not impair the characteristics, depending on the hydraulic component used in the hydraulic composition of the present invention. Specifically, the hydraulic composition of the present invention is preferably 0.01 to 2.0 parts by weight, more preferably 0.05 to 1.0 parts by weight, with respect to 100 parts by weight of the hydraulic component. Particularly preferably, 0.1 to 0.5 parts by mass of a fluidizing agent can be blended. If the addition amount is too small, a suitable effect (excellent fluidity and high cured body strength) will not be exhibited. Therefore, it is preferable that the addition amount is not less than the lower limit of these ranges. These effects are not only uneconomical and are not uneconomical, but in some cases, the viscosity may increase and the amount of kneading water to obtain the required fluidity may increase, resulting in deterioration of strength properties. It is preferable that it is below the upper limit of the range.

<Optional components such as inorganic components>
The hydraulic composition of the present invention preferably further contains one or more components selected from inorganic components, setting retarders, setting accelerators, thickeners and antifoaming agents. Moreover, it is preferable that the hydraulic slurry prepared by kneading the hydraulic composition of the present invention and water has self-fluidity. In the present specification, the hydraulic slurry having “self-fluidity” refers to a hydraulic slurry having a flow value described later of 190 mm or more.

<Inorganic component>
The hydraulic composition of the present invention contains at least one inorganic component selected from blast furnace slag fine powder, fly ash and silica fume, and preferably contains blast furnace slag fine powder. By including these inorganic components, the crack resistance of the cured product due to drying shrinkage can be enhanced.

  In the hydraulic composition, when the inorganic component is blast furnace slag fine powder, the addition amount of the blast furnace slag fine powder is preferably 10 to 350 parts by mass, more preferably 30 to 30 parts by mass with respect to 100 parts by mass of the hydraulic component. 200 parts by mass, more preferably 50 to 150 parts by mass, particularly preferably 70 to 130 parts by mass. If the addition amount of the blast furnace slag fine powder is too small, the drying shrinkage of the cured body increases, and therefore, it is preferably at least the lower limit of these ranges. Moreover, since there may be a fall of initial intensity | strength when there is too much addition amount of blast furnace slag fine powder, it is preferable that it is below the upper limit of these ranges.

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.

<Setting agent>
The setting modifier added to the hydraulic composition of the present invention can be appropriately added within a range that does not impair the characteristics, depending on the hydraulic component and components other than the hydraulic component used in the hydraulic composition. Moreover, the pot life and quick-hardness of a hydraulic composition can be adjusted by selecting suitably the component, addition amount, and mixing ratio of a setting retarder and a setting accelerator.

<Set retarder>
As the setting retarder, a known setting retarder can be used. Examples of setting retarders include organic acids such as sodium tartrate (monosodium tartrate, disodium tartrate), sodium malate, sodium citrate, and sodium gluconate, and their sodium salts and sodium sulfate. And inorganic sodium salts such as sodium bicarbonate, sodium phosphate, sodium polyphosphate and sodium tripolyphosphate. The setting retarder can be used alone or in combination of two or more of these components.

  Oxycarboxylic acids that are a kind of setting retarder include oxycarboxylic acids and salts thereof. 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 (specifically, sodium salts, potassium salts, etc.) and alkaline earth metal salts (specifically, calcium salts, barium salts, magnesium salts, etc.) of oxycarboxylic acids. Can be mentioned.

  In particular, it is preferable to use sodium bicarbonate and / or disodium tartrate as a setting retarder to be added to the hydraulic composition of the present invention from the viewpoints of setting retarding effect, availability, and cost.

  The setting retarder to be added to the hydraulic composition of the present invention is preferably 0.01 to 2.0 parts by mass, and more preferably 0.8 to 100 parts by mass of the hydraulic component in the hydraulic composition. It can be used in the range of 1 to 1.5 parts by mass, more preferably 0.2 to 1.2 parts by mass, and particularly preferably 0.4 to 1 part by mass. It is preferable that the addition of the setting retarder is within these ranges because the pot life (handling time) at which suitable fluidity can be obtained can be secured in the hydraulic slurry using the hydraulic composition of the present invention.

<Setting accelerator>
As the setting accelerator to be added to the hydraulic composition of the present invention, a known component for promoting setting can be used, and for example, a lithium salt having a setting promoting effect can be preferably used.

  Examples of the lithium salt that is a setting accelerator added to the hydraulic composition of the present invention include inorganic lithium salts such as lithium carbonate, lithium chloride, lithium sulfate, lithium nitrate and lithium hydroxide, and lithium acetate, lithium oxalate, and tartaric acid. Organic acid lithium salts such as lithium, lithium malate and lithium citrate can be mentioned, and these lithium salts can be used as a setting accelerator. In particular, lithium carbonate is preferable from the viewpoints of the setting acceleration effect, availability, and cost.

  As the particle size of the setting accelerator, it is preferable to use a particle size in a range that does not interfere with the characteristics of the hydraulic composition of the present invention, and it is preferable to use a particle size of 50 μm or less. In particular, when lithium salt is used as a setting accelerator, the particle diameter of the lithium salt is preferably 50 μm or less, more preferably 30 μm or less, and particularly preferably 10 μm or less. In particular, the pigment addition system is conspicuous as a large number of fine spots, which may impair the aesthetic appearance. Therefore, the particle size of the lithium salt is preferably not more than the upper limit of the above range.

  The setting accelerator added to the hydraulic composition of the present invention is preferably 0.01 to 1 part by mass, more preferably 0.001 parts by mass with respect to 100 parts by mass of the hydraulic component of the hydraulic composition of the present invention. It is used in the range of 01 to 0.5 parts by mass, more preferably 0.02 to 0.3 parts by mass, particularly preferably 0.04 to 0.2 parts by mass. When the addition amount of the setting accelerator is within this range, it is preferable in the hydraulic slurry using the hydraulic composition of the present invention that suitable fast curing is obtained after securing the pot life.

<Thickener>
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 to the hydraulic composition of the present invention can be added within a range not impairing the characteristics of the present invention, and preferably 0.001 to 2 parts by mass with respect to 100 parts by mass of the hydraulic component. More preferably, it is 0.01 to 1.5 parts by mass, more preferably 0.05 to 1 part by mass, and particularly preferably 0.1 to 0.8 parts by mass. When the amount of the thickener added to the hydraulic composition is increased, the viscosity of the hydraulic slurry may increase and the fluidity may be lowered.

  In the hydraulic composition of the present invention, the combined use of a thickener and an antifoaming agent is for suppressing the separation of aggregates such as hydraulic components and fine aggregates, suppressing the generation of bubbles, and improving the surface of the cured body. It is preferable for giving a preferable effect and improving the properties of the cured product of the hydraulic composition.

<Antifoaming agent>
As the antifoaming agent added to the hydraulic composition of the present invention, known materials such as synthetic materials such as silicon-based, alcohol-based and polyether-based materials, mineral oil-based materials, or plant-derived natural materials can be used.

  The amount of the antifoaming agent added to the hydraulic composition of the present invention can be added within a range that does not impair the characteristics of the present invention, and preferably 0.001 to 2 parts by mass with respect to 100 parts by mass of the hydraulic component. More preferably, it is 0.01 to 1.5 parts by mass, more preferably 0.05 to 1 part by mass, and particularly preferably 0.1 to 0.5 parts by mass. It is preferable that the addition amount of the antifoaming agent is within the above range since a suitable antifoaming effect is observed.

<Other optional components>
In the hydraulic composition of the present invention, a shrinkage reducing agent, a resin powder, or the like can be appropriately selected and used when the effect of preventing and suppressing dry cracks is further increased.

<Preferred component composition>
In the case of constituting the hydraulic composition of the present invention, particularly suitable component constitution is a hydraulic component comprising alumina cement, Portland cement and predetermined gypsum, fine aggregate such as dredged sand, fluidizing agent, inorganic component, setting It contains a regulator, a thickener and an antifoaming agent.

  In addition, even when the temperature conditions during construction change, it is possible to maintain a stable and high fluidity for a long period of time, excellent in fast curing and horizontal level properties, and to stably obtain a cured body having a good finished surface. Therefore, the concrete floor structure preferably has a hardened layer of a hydraulic slurry using the hydraulic composition of the present invention as a surface layer.

<Manufacturing method>
The hydraulic composition of the present invention is prepared by mixing a predetermined amount of hydraulic component and fine aggregate, and if necessary, a fluidizing agent, an inorganic component, a setting modifier, a thickener, an antifoaming agent, and the like with a mixer. Can be obtained.

  The premix powder of the hydraulic composition can be produced by mixing and stirring with a predetermined amount of water to produce slurry-like hydraulic slurry having self-fluidity, and applying and curing the hydraulic slurry. Thus, a cured product of the hydraulic composition can be obtained. In particular, a concrete floor structure excellent in horizontal level having a hardened layer of a hydraulic slurry using the hydraulic composition of the present invention on the surface layer by applying and curing the hydraulic slurry on concrete. Can be obtained.

  The hydraulic composition of the present invention can be mixed and stirred with water to produce a hydraulic slurry. By adjusting the amount of water added, the fluidity of the hydraulic slurry, pot life, material separability The strength of the cured product can be adjusted. The amount of water added to the hydraulic composition of the present invention is preferably 10 to 40 parts by mass, more preferably 14 to 34 parts by mass, and more preferably 18 to 30 parts by mass with respect to 100 parts by mass of the hydraulic composition. It is particularly preferable to add and use in the range of 22 to 28 parts by mass.

  The flow value of the self-fluidic hydraulic slurry prepared by mixing the hydraulic composition of the present invention with water is preferably adjusted to 190 to 270 mm, more preferably 200 to 260 mm, and particularly preferably 210 to 250 mm. It is preferable for the reason that it is easy to obtain a hardened body surface with high ease of construction and high smoothness.

  The hydraulic slurry using the hydraulic composition of the present invention starts curing within 0.5 hours to 3 hours after the completion of construction, and the surface hardness of the cured body increases with the progress of curing. The water content on the surface is reduced. The shore hardness of the surface of the cured body of the hydraulic slurry is preferably 30 or more after 3 hours, more preferably 35 or more after 3 hours, more preferably 40 or more after 3 hours, particularly preferably from the placement (construction) of the hydraulic slurry. Can be 45 or more after 3 hours. Therefore, after the slurry construction is completed, the construction of the hydraulic slurry can be completed by the rapid progress of curing.

<Application>
When the hydraulic composition of the present invention is used as a self-leveling material taking advantage of excellent self-fluidity, it is used in schools, condominiums, convenience stores, hospitals, verandas, factories, warehouses, parking lots, gas stations, kitchens, rooftops, etc. It can be used for flooring and floor finishing materials.

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

(1) Evaluation of hydraulic slurry:
For the evaluation, a hydraulic slurry immediately after kneading prepared by kneading the hydraulic composition and water was used.
-Self-leveling property (self-fluidity): flow value and SL value The flow value was measured according to JASS 15M-103. That is, a pipe made of vinyl chloride (internal volume: 100 ml) having an inner diameter of 50 mm and a height of 51 mm was placed on a 5 mm thick sheet glass, filled with kneaded hydraulic slurry, and then pulled up. After the spread stopped, the diameters in two directions at right angles were measured, and the average value was taken as the flow value.

  The SL value shown in FIG. 1 was used for the SL value. The SL measuring instrument has a structure in which a rail having a width of 30 mm, a height of 30 mm, and a length of 750 mm and a barrier plate is provided at a length of 150 mm from the end of the rail. A hydraulic slurry was formed by filling a predetermined amount of the slurry immediately after kneading between the rail tip and the weir plate. Pull up the weir plate immediately after forming the hydraulic slurry, and after stopping the flow of the hydraulic slurry, from the gauge point (the place where the dam plate is installed) to the part closest to the gauge point (the shortest part) at the tip of the hydraulic slurry flow The distance (SL value) was measured as L0. Similarly, after 10 minutes, 20 minutes or 30 minutes after molding, the weir plate is pulled up, and after stopping the flow of hydraulic slurry, the distance from the gauge point (the installation portion of the weir plate) to the shortest portion of the flow of hydraulic slurry The value (SL value) was measured as L10, L20, or L30. The evaluation was performed under temperature and humidity conditions of temperatures of 20 ° C., 25 ° C. and 35 ° C. and a humidity of 65%.

(2) Hardened body surface state:
The cured slurry surface of the hydraulic slurry is prepared by pouring the prepared hydraulic slurry into a 13 cm × 19 cm resin mold at a thickness of 10 mm, and visually observing the surface finish after 24 hours of curing. It was evaluated with. Evaluation was as follows. The evaluation conditions were as follows: temperature 20 ° C., 25 ° C. and 35 ° C. and humidity 65%.
○: Excellent surface finish (no bubbles, no powdering)
X: poor surface finish (bubbles and / or powdered)

(3) Shore hardness of the cured body surface:
Measure the hardness of the hardened surface at any 3 to 5 locations using a spring-type hardness tester type D (manufactured by Ueshima Seisakusho Co., Ltd.) at a predetermined elapsed time after placing the hydraulic slurry. The average value of the readings of the spring type hardness tester type D gauge was defined as the surface hardness at that time.

The following materials were used.
1) Hydraulic component-Alumina cement (Fonju, Kerneos, Blaine specific surface area 3100 cm ² / g).
Portland cement (early strong cement, manufactured by Ube Mitsubishi Cement Co., Ltd., Blaine specific surface area 4500 cm ² / g).
Gypsum a: Hydrous acid byproduct anhydrous gypsum using calcium carbonate as a desulfurization neutralizer (Central Glass Co., Ltd., Ca (OH) ₂ content = 0.00%, pH = 6.5).
Gypsum b: Anhydrous gypsum byproduct of hydrofluoric acid using calcium hydroxide as a desulfurization neutralizer (Asahi Glass Co., Ltd., Ca (OH) ₂ content = 0.00%, pH = 8.4).
Gypsum c: Anhydrous gypsum by-product of hydrofluoric acid using calcium hydroxide as a desulfurization neutralizer (Asahi Glass Co., Ltd., Ca (OH) ₂ content = 0.30%, pH = 11.3).
Gypsum d: Anhydrous gypsum byproduct of hydrofluoric acid using calcium hydroxide as a desulfurization neutralizer (Asahi Glass Co., Ltd., Ca (OH) ₂ content = 0.63%, pH = 11.7).
2) Fine aggregate ・ Silica sand: No. 6 silica sand.
3) Fluidizer: Polycarboxylic acid fluidizer (manufactured by Kao Corporation).
4) Inorganic component-Blast furnace slag fine powder (Reverment, manufactured by Chiba Rebirth, Blaine specific surface area 4400 cm ² / g).
5) Setting agent:
-Bicarbonate Na: Sodium bicarbonate (made by Tosoh Corporation).
-Sodium tartrate: L-sodium tartrate (manufactured by Fuso Chemical Industries).
-Carbonic acid Li: Lithium carbonate (made by Honjo Chemical Co., Ltd.).
6) Thickener: Hydroxyethylmethylcellulose thickener (Marporose MX-30000, manufactured by Matsumoto Yushi Co., Ltd.).
7) Antifoaming agent: Polyether type antifoaming agent (manufactured by San Nopco).

<Examples 1-3, Reference Examples 1-9>
Hydraulic composition obtained by kneading the hydraulic component, fine aggregate, fluidizing agent, inorganic component, setting modifier, thickener and antifoaming agent (total amount: 1.5 kg) shown in Table 1 using a chemistor. And 390 g of water was further added and kneaded for 3 minutes to obtain a hydraulic slurry. The hydraulic composition and the hydraulic slurry were prepared under the temperature and humidity conditions of temperatures of 20 ° C., 25 ° C. and 35 ° C. and a humidity of 65%.

  Using the obtained hydraulic slurry, SL (self-leveling) characteristics, Shore hardness development, and the surface finish of the cured body were evaluated. The results are shown in Table 2.

  As shown in Reference Examples 1 to 9, when gypsum b, c, and d using calcium hydroxide as a desulfurization neutralizer is used, the fluidity retention time of the hydraulic slurry is increased when the construction temperature of the hydraulic slurry is increased. Shortened. On the other hand, as shown in Examples 1 to 3, when using gypsum a using calcium carbonate as a desulfurization neutralizer, the construction temperature of the hydraulic slurry is in a wide temperature range of 20 ° C to 35 ° C. The fluidity was maintained for a long time, and the temperature dependence of the flow characteristics of the hydraulic slurry was greatly reduced.

  The hydraulic slurry using the hydraulic composition of the present invention can stably maintain high fluidity for a long time even when the temperature condition during construction changes, and therefore, good handling properties can be obtained. It is excellent in hardness and horizontal level property, and a cured product having a good finished surface can be obtained stably.

It is a schematic diagram which shows the outline of the self-leveling property evaluation of a hydraulic slurry using SL measuring device.

Claims (6)

A hydraulic composition including a hydraulic component including a cement component and gypsum, fine aggregate, and blast furnace slag fine powder ,
Gypsum is gypsum by-produced in the hydrofluoric acid production process using calcium carbonate as a desulfurization neutralizer and does not contain calcium hydroxide ;
The hydraulic component consists of 20 to 80% by mass of alumina cement, 5 to 70% by mass of Portland cement, and 5 to 45% by mass of gypsum, where the total of hydraulic components is 100% by mass.
A hydraulic composition containing 10 to 350 parts by mass of blast furnace slag fine powder with respect to 100 parts by mass of a hydraulic component .   The hydraulic composition according to claim 1, wherein the hydraulic composition further comprises a fluidizing agent.   The hydraulic composition according to claim 1 or 2, wherein the gypsum has a pH of 5.5 to 7.5. The hydraulic composition includes a hydraulic component made of alumina cement, Portland cement and gypsum, fine aggregate, and a fluidizing agent,
Hydraulic composition further comprises condensation to retarders, setting accelerators, at least one or more components selected from thickening agents and defoaming agents,
The hydraulic composition according to any one of claims 1 to 3 , wherein the hydraulic slurry prepared by kneading the hydraulic composition and water has self-fluidity. A hydraulic composition, a Shore hardness of the cured surface of the water and the hydraulic slurry prepared by kneading a is, by applying a hydraulic slurry is 30 or more after 3 hours, claim 1-4 1 The hydraulic composition according to Item. The concrete floor structure which has the hardening body layer of the hydraulic slurry using the hydraulic composition of any one of Claims 1-5 in a surface layer.

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