JP2008162836A - Self fluidity hydraulic composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a hydraulic composition having high fluidity, rapidly advancing the hardening after the finish of construction work while keeping usable life sufficient to easily carry out the construction work and obtaining excellent leveling property and surface finishing property and particularly having self leveling property by which the remarkable surface finishing property is attained even in construction under a high temperature environment. <P>SOLUTION: The hydraulic composition having self fluidity contains a hydraulic component comprising alumina cement, portland cement and gypsum, a setting accelerator and fine aggregate. The setting accelerator contains potassium sulfate and a lithium salt. The fine aggregate contains 3-20 mass% fine particles of 30-150 μm and 97-80 mass% particle of 150-850 μm, based on 100 mass% fine aggregate. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

The present invention is a self-leveling material mainly used for floor foundation adjustment of general buildings, and has sufficient pot life in on-site construction, and is capable of obtaining an excellent finished surface of the cured body. The present invention relates to a fluid hydraulic composition.

The hydraulic composition used as a self-leveling material has high fluidity to ensure self-smoothness, sufficient fastness to enable early opening, and moderate use in terms of facilitating construction work. It is required that time is taken.
Decrease in fluidity over time, good workability, low shrinkage to reduce shrinkage due to drying, fast hardening in a short time, strength development that can express strength early, Regarding super-fast-hardening cement composition with excellent adhesion strength and long-term stability, Patent Document 1 discloses a mixture of calcium fluoroaluminate clinker and Portland cement and alumina cement as quick-hardening material, anhydrous gypsum, slaked lime, setting modifier, potassium sulfate. And a super hard cement composition comprising lithium carbonate is disclosed.
Patent Document 2 discloses a hydraulic component composed of Portland cement, a CaO—Al ₂ O ₃ -based compound and anhydrous gypsum as a hydraulic cement composition exhibiting good strength expression even at a low temperature of 0 ° C. or lower, A low temperature setting cement composition containing one or more inorganic salts selected from the group consisting of alkali metal carbonates, sulfates, aluminates and chlorides is disclosed.
For the purpose of improving the short-term strength development without reducing the long-term strength of the low heat cement cured body, Patent Document 3 discloses that 1.0 g / 100 g or more with respect to water at 25 ° C. with respect to high belite cement. Low heat cement containing a hardening accelerator composed of one or more sulfates having a solubility of (for example, potassium sulfate, magnesium sulfate, etc.) in an addition amount of 0.3 to 4.0% of the weight of high belite cement. A composition is disclosed.

JP 2005-324982 A JP 62-288150 A JP-A-11-157906

  The present invention has high fluidity and maintains sufficient pot life to facilitate construction work, while curing progresses rapidly after the construction work is finished, excellent horizontal level and extremely good surface An object of the present invention is to provide a self-leveling hydraulic composition capable of obtaining finish and obtaining excellent surface finish even in the construction under a high temperature environment.

  The first of the present invention is a hydraulic composition comprising a hydraulic component comprising alumina cement, Portland cement and gypsum, a setting accelerator, and a fine aggregate. The setting accelerator includes potassium sulfate and a lithium salt. The fine aggregate contains 3 to 20% by mass of fine particles of 30 μm to less than 150 μm in 100% by mass of fine aggregate, and contains 97 to 80% by mass of particles of 150 μm to less than 850 μm. It is a fluid hydraulic composition.

The second of the present invention is a mortar obtained by kneading the self-flowing hydraulic composition of the present invention and water.
The third aspect of the present invention is a cured product obtained by curing a mortar obtained by kneading the self-flowing hydraulic composition of the present invention and water.

Preferred embodiments of the self-flowing hydraulic composition of the present invention are shown below. A plurality of preferred embodiments can be combined.
1) The hydraulic component is a hydraulic component composed of 20-80% by mass of alumina cement, 10-55% by mass of Portland cement, and 5-50% by mass of gypsum.
2) The potassium sulfate is 0.02 to 1.0 part by mass with respect to 100 parts by mass of the hydraulic component.
3) The hydraulic composition contains a setting retarder, and further contains at least one component selected from a fluidizing agent, a thickener, and an antifoaming agent.
4) The hydraulic composition contains at least one inorganic component selected from fine blast furnace slag powder, fly ash and silica fume.

  The self-flowing hydraulic composition of the present invention has potassium sulfate as a setting accelerator, while ensuring excellent fluidity and sufficient pot life to facilitate construction work due to the effect of adding a setting retarder. In combination with lithium salt, hardening can proceed rapidly after the construction work is completed, and by using an appropriate amount of fine aggregate, by suppressing and eliminating material separation in the mortar surface layer Excellent horizontal level and excellent surface finish. The drying phenomenon on the surface of the cured body is particularly severe, and excellent surface finish can be obtained even in the construction in a high temperature environment that is extremely severe for finishing the surface of the cured body.

The present invention is a hydraulic composition comprising a hydraulic component composed of alumina cement, Portland cement and gypsum, a setting accelerator, and a fine aggregate.
The present invention relates to a self-flowing hydraulic composition characterized in that the setting accelerator includes potassium sulfate and a lithium salt, and the fine aggregate includes fine aggregate.

In the present invention, a hydraulic component made of alumina cement, Portland cement and gypsum is used as the hydraulic component.
The hydraulic component is
Preferably,
A composition comprising 20 to 80 parts by mass of alumina cement, 10 to 55 parts by mass of Portland cement and 5 to 50 parts by mass of gypsum (the total of alumina cement, Portland cement and gypsum is 100 parts by mass),
More preferably,
A composition comprising 26 to 70 parts by mass of alumina cement, 15 to 50 parts by mass of Portland cement, and 8 to 40 parts by mass of gypsum (the total of alumina cement, Portland cement and gypsum is 100 parts by mass),
More preferably,
A composition comprising 33-60 parts by mass of alumina cement, 22-45 parts by mass of Portland cement and 10-35 parts by mass of gypsum (the total of alumina cement, Portland cement and gypsum is 100 parts by mass),
Particularly preferably,
A composition comprising 40-50 parts by mass of alumina cement, 29-40 parts by mass of Portland cement and 15-30 parts by mass of gypsum (the total of alumina cement, Portland cement and gypsum is 100 parts by mass),
Is preferred because it is easy to obtain a cured product having rapid hardening, low shrinkage or low expansion and little volume change during curing.

  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.

  For Portland cement, normal Portland cement, early-strength Portland cement, super early-strength Portland cement, moderately hot Portland cement, white Portland cement and other Portland cement, blast furnace cement, fly ash cement, silica cement and other mixed cement 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 self-flowing 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 in particular, a cured product due to drying shrinkage by containing the blast furnace slag fine powder. The crack resistance can be improved.
In the self-flowing hydraulic composition, the amount of the inorganic component added is preferably 10 to 350 parts by mass, more preferably 30 to 200 parts by mass, and still more preferably 50 to 150 parts by mass with respect to 100 parts by mass of the hydraulic component. Especially preferably, it is preferable to set it as 70-130 mass parts.

In the self-flowing hydraulic composition, the addition amount of the blast furnace slag fine powder is preferably 10 to 350 parts by mass, more preferably 30 to 200 parts by mass, and still more preferably 50 to 150 parts per 100 parts by mass of the hydraulic component. It is preferable to set it as a mass part, Especially preferably, it is 70-130 mass parts. If the addition amount of the blast furnace slag fine powder is too small, the drying shrinkage of the cured body increases, and if it is too large, the initial strength may be lowered.
As the blast furnace slag fine powder, a brane specific surface area of 3000 cm ² / g or more as defined in JIS A 6206 can be suitably used.

In the self-flowing hydraulic composition of the present invention, the mortar obtained by kneading the self-flowing hydraulic composition and water has a rapid water-drawing property while ensuring good flowability and sufficient pot life. In order to obtain excellent surface finish, a specific setting accelerator and fine aggregate are used in combination.

The setting accelerator accelerates the setting after construction to speed up the watering of the mortar surface, and further accelerates the hardening of the mortar, so that the mortar surface generated in the time until the uncured mortar starts hardening This has the effect of suppressing and eliminating material separation.
In the present invention, by using potassium sulfate and a lithium salt in combination as a setting accelerator, the hardening of the mortar is accelerated rapidly, and the mortar structure is removed before the slight material separation that affects the surface properties proceeds. Further, this effect can be combined with the material separation resistance of the uncured mortar itself, which is enhanced by using fine aggregates, to obtain an excellent cured body surface finish.

In the present invention, potassium sulfate is used, and preferably 0.02 to 1.0 parts by mass, more preferably 0.05 to 0.9 parts by mass, and more preferably 0.08 to 100 parts by mass of the hydraulic component. It is preferable to use in the range of ˜0.8 parts by mass, particularly preferably in the range of 0.1 to 0.7 parts by mass, because a good curing acceleration effect can be obtained without greatly impairing the flow characteristics of the mortar.
If the amount of potassium sulfate used is less than 0.1 parts by mass, the effect of promoting the curing is insufficient, so it takes time for watering the surface of the mortar to be applied, and the surface hardness of the mortar hardened body is also high early. It is not preferable because it is difficult. Moreover, when it adds exceeding 1.0 mass part excessively, since a favorable hardened | cured body surface may not be obtained, it is unpreferable.

In the present invention, potassium sulfate and a lithium salt are used together as a setting accelerator.
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.

The lithium salt is based on 100 parts by mass of the hydraulic component.
Preferably it is 0.01-1 mass part, More preferably, it is 0.01-0.5 mass part, More preferably, it is 0.02-0.3 mass part, Most preferably, it is 0.04-0.2 mass part. By using in this range, after securing the pot life of a hydraulic composition, it is preferable from suitable quick-hardening being obtained.

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 50 μm or less, more preferably 30 μm or less, and particularly preferably 10 μm or less. If the particle diameter is larger than the above range, the solubility of the lithium salt decreases, which is not preferable. Then, it may be conspicuous as a large number of fine spots, and the appearance may be impaired.

Fine aggregate used in the self-flowing hydraulic composition of the present invention,
In addition to improving mortar fluidity, water retention inside the mortar is improved to improve material separation resistance, and fine aggregate containing an appropriate amount of fine aggregate is used to suppress water floating (breathing) on the mortar surface. It is preferable to do.

The fine aggregate preferably contains 3 to 20% by mass of fine particles of 30 μm or more to less than 150 μm in 100% by mass of fine aggregate, and more preferably 97 to 80% by mass of particles of 150 μm or more to less than 850 μm. Contains 4 to 20% by mass of fine particles of 30 μm or more to less than 150 μm in 100% by mass of fine aggregate, and 96 to 80% by mass of particles of 150 μm or more to less than 850 μm, particularly preferably fine aggregate 100 A material containing 4.5 to 20% by mass of fine particles of 30 μm or more and less than 150 μm and 95.5 to 80% by mass of particles of 150 μm or more and less than 850 μm in the mass% is a mortar fluidity and material separation resistance. It can be preferably used from the viewpoint of suppression of water floating.
When the fine aggregate contains particles of 150 μm or more and less than 850 μm in an amount of less than 80% by mass, the amount of water necessary for obtaining particularly suitable fluidity or the addition amount of a fluidizing agent is preferably increased. In the case where particles of 30 μm or more to less than 150 μm are contained in an amount of less than 3% by mass, sufficient water retention of the mortar cannot be obtained, and it becomes difficult to impart sufficient material separation resistance, and until the mortar is cured. This is not preferable because the effect of suppressing water floating is reduced, and the finished state of the surface of the cured body may be poor.

The fine aggregate that can be suitably used in the present invention is not particularly limited in its preparation method as long as it satisfies the above-mentioned particle size constitution. For example, silica sand (No. 6 silica sand as shown in Table 4) is used. ) And fine silica sand are appropriately mixed to prepare and use a mixed sand satisfying a preferable particle size constitution containing an appropriate amount of fine particles of less than 150 μm. Fine aggregate having a fine particle size constitution (fine aggregate) It is particularly preferable in obtaining.
The fine aggregate used in the present invention preferably does not contain particles having a particle size of 1180 μm or more, more preferably does not contain particles of 850 μm or more, and particularly preferably does not contain particles of 600 μm or more. Since the flow characteristics and material separation characteristics of the mortar can be obtained, smooth and excellent surface finish can be obtained stably.

  The amount of fine aggregate added 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. It is preferable to use within the range of parts.

Fine aggregates include silica sand, river sand, sea sand, mountain sand, crushed sand, etc., alumina cement clinker, silica powder, clay mineral, waste FCC catalyst, inorganic materials such as limestone, urethane crushed, EVA foam, foam A resin pulverized product such as a resin 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.

The self-flowing hydraulic composition uses a fluidizing agent (water reducing agent such as a high-performance water reducing agent) that ensures suitable fluidity while suppressing material separation.
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.
Commercially available fluidizing agents such as formaldehyde condensates of melamine sulfonic acid, casein, calcium caseinate, polyethers, polyether polycarboxylic acids, etc., which have a water-reducing effect, are used regardless of the type of fluidizing agent. In particular, commercially available fluidizing agents such as polyether-based polycarboxylic acids such as polyether-based are 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 0.3 parts by mass. If the addition amount is too small, no suitable effect (excellent fluidity and high cured body strength) will be exhibited, and if the addition amount is too large, an effect commensurate with the addition amount cannot be expected and it is merely uneconomical. In some cases, the viscosity is increased, and the amount of kneading water for obtaining the required fluidity increases to deteriorate the strength properties.

As the thickener, a thickener containing hydroxyethylmethylcellulose can be suitably used, and hydroxyethylmethylcellulose is used in combination with other cellulose-based, protein-based, latex-based, and water-soluble polymer-based thickeners. Can be used.
The addition amount of the thickener can be added within a range that does not impair the characteristics of the present invention, and is preferably 0.001 to 2 parts by mass, more preferably 100 parts by mass with respect to 100 parts by mass of the self-flowing hydraulic composition. 0.01 to 1 part by mass, more preferably 0.05 to 0.7 part by mass, particularly preferably 0.1 to 0.5 part 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.
The combined use of a thickener and an antifoaming agent has a favorable effect on suppression of separation of aggregates such as hydraulic components and fine aggregates, suppression of bubble generation, and improvement of the surface of the cured body. It is preferable for improving the properties of the cured product.

  The setting retarder can be added as appropriate within the range that does not impair the properties, depending on the hydraulic component and hydraulic composition to be used, and the use amount of the hydraulic composition can be selected by appropriately selecting the addition amount and the mixing ratio. Used to adjust time and fast setting.

  As the setting retarder, a known setting retarder can be used. As an example of a setting retarder, an organic acid such as oxycarboxylic acid or a salt thereof, an inorganic salt such as sodium bicarbonate or sodium phosphate, and the like, each component being used alone or in combination of two or more components. I can do it.

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 monosodium tartrate are preferable from the standpoints of setting delay effect, availability, and cost.

The setting retarder is based on 100 parts by mass of the hydraulic component.
Preferably it is 0.01-2 mass parts, More preferably, it is 0.1-1.6 mass parts, More preferably, it is 0.2-1.4 mass parts, Most preferably, it is 0.4-1.2 mass parts. It is preferable because the pot life (handling time) for obtaining suitable fluidity can be ensured.

As the antifoaming agent, known materials such as synthetic materials such as silicon-based, alcohol-based and polyether-based materials or plant-derived natural materials can be used.
The addition amount of the antifoaming agent can be added within a range that does not impair the characteristics of the present invention, and with respect to 100 parts by mass of the hydraulic component,
Preferably it is 0.001-2 mass part, More preferably, it is 0.005-1.5 mass part, More preferably, it is 0.01-1 mass part, It is preferable to contain 0.05-0.5 mass part especially. 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 self-flowing hydraulic composition of the present invention, particularly suitable component constitutions are hydraulic components composed of alumina cement, Portland cement and gypsum, setting accelerators, setting retarders, fine aggregates, silica sand, etc. Inorganic components such as fine aggregate, blast furnace slag fine powder, fluidizing agent, thickener and antifoaming agent.

  In the present invention, when constituting a self-flowing hydraulic composition, a hydraulic component composed of alumina cement, Portland cement and gypsum, a setting accelerator, a setting retarder, a fine aggregate such as fine sand, cinnabar, a blast furnace An inorganic component such as slag fine powder, a fluidizing agent, a thickening agent, an antifoaming agent, and the like can be mixed in a mixer to obtain a premix powder of a self-fluid hydraulic composition.

  The premix powder of the self-flowing hydraulic composition can be mixed and stirred with a predetermined amount of water to produce a slurry-like self-leveling property (self-flowing) mortar. Thus, a cured product of the self-flowing hydraulic composition can be obtained.

Self-fluid hydraulic composition can be mixed and stirred with water to produce mortar. By adjusting the amount of water added, mortar fluidity, pot life, material separation resistance, mortar hardening The strength of the body can be adjusted.
The amount of water added is preferably 10 to 40 parts by mass, more preferably 14 to 34 parts by mass, more preferably 18 to 30 parts by mass, particularly preferably 22 to 100 parts by mass with respect to 100 parts by mass of the self-flowing hydraulic composition. It is preferable to add and use in the range of 28 parts by mass.

  The self-flowing hydraulic composition of the present invention has a flow value of a mortar having self-leveling property (self-flowing property) prepared by mixing with water, preferably 190 to 270 mm, more preferably 200 to 260 mm, particularly preferably. Is preferably adjusted to 210 to 250 mm for the reason that it is easy to obtain a hardened product surface with high ease of construction and high smoothness.

  The SL value L0 is preferably 350 mm or more, more preferably 400 mm or more, more preferably 440 mm or more, and particularly preferably 450 mm or more, so that it is easy to obtain a cured body surface that is easy to construct and highly smooth. Preferred for reasons.

  The self-flowing hydraulic composition of the present invention has a slurry drainage (surface moisture drying time) of a slurry produced by mixing with water, preferably 30 to 120 minutes, more preferably 30 to 100 minutes, particularly preferably. It is preferable to adjust in the range of 30 to 90 minutes.

  In the self-flowing hydraulic composition of the present invention, the surface hardness of the cured product obtained by curing the slurry produced by mixing with water is preferably 20 or more after 2 hours from the slurry preparation, more preferably 1 hour from the slurry preparation. In order to ensure quick workability, it is preferable that the surface hardness of the cured body after that is 20 or more, particularly preferably, the surface hardness of the cured body after 1 hour from the slurry preparation is 50 or more.

The self-flowing hydraulic composition of the present invention can be used as a self-leveling material such as a floor foundation adjustment having fluidity and fluidity retention by adding water within a range that does not impair the characteristics, and is 5 to 40 ° C. Within the temperature range, it can be used as a floor base preparation or floor finishing material with excellent self-leveling and excellent surface finish at construction sites such as factories, warehouses, parking lots, gas stations, kitchens, and condominiums. it can.

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

(1) Mortar evaluation:
As the mortar used for evaluation, a mortar immediately after kneading prepared by kneading a self-flowing hydraulic composition and water is used.
・ Flow value:
Measured according to the method described in JASS 15M-103.
・ Self leveling:
Using the SL measuring device shown in FIG. 1, a barrier plate is provided on a rail having a width of 30 mm × a height of 30 mm × a length of 750 mm and a length of 150 mm from the tip, and a predetermined amount of slurry immediately after kneading is filled and molded. Immediately after the molding, the weir plate is pulled up, and after the slurry flow is stopped, the distance from the gauge point (the installation portion of the weir plate) to the shortest portion of the slurry flow is measured, and the value (SL value) is set to L0. The time for 200 mm is measured, and the measurement time is defined as SL flow velocity (L0) (second / 200 mm).
Evaluation conditions are performed in an environment of a temperature of 30 ° C. and a humidity of 65%.
Water draining: The prepared slurry is poured into a 13 cm × 19 cm resin mold with a thickness of 10 mm, and then the time until the slurry does not adhere even if the curing progresses and the surface is lightly touched.

(2) Evaluation of cured body:
·surface hardness:
At a predetermined elapsed time after the slurry is cast, the hardness of the hardened surface is measured by using a spring type hardness tester type D (manufactured by Ueshima Seisakusho Co., Ltd.), and the surface hardness is measured at arbitrary 3 to 5 locations. The average value of the reading values of the spring type hardness tester type D gauge is defined as the surface hardness at that time.
-Mortar surface state The finished state of the mortar hardened body surface was evaluated by pouring the prepared slurry into a 13 cm x 19 cm resin mold at a thickness of 10 mm and after 24 hours. Surface powdering was evaluated by visual observation. None The skin was in a state where fine irregularities were generated on the surface of the cured body, and was evaluated by touching with a hand. Yuzu skin was in a state where small protrusions having a width of 1 to 2 mm were generated and evaluated by visual observation. The evaluation criteria for the surface finish were as follows, assuming the time of construction.
5: Excellent, 4: Good, 3: No problem, 2: Somewhat bad, 1: Bad.

The following materials were used.
1) Hydraulic component / alumina cement (Fonju, manufactured by Lafarge Aluminate, 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: Type ^II anhydrous gypsum (manufactured by Central Glass, Blaine specific surface area 3460 cm ² / g).
2) Inorganic component / blast furnace slag fine powder (Reverment, manufactured by Chiba Riverment Co., Ltd., Blaine specific surface area 4400 cm ² / g).
3) Fine aggregate and silica sand: No. 6 silica sand (manufactured by Tokai Sand Co., Ltd.). Table 3 and Table 4 show the particle size composition of No. 6 silica sand.
-Fine silica sand: N70 (manufactured by Ashiya). Table 4 shows the particle size composition of the fine aggregate.
4) Mixed sand ac
-Silica sand shown in Table 4 and fine silica sand were mixed to prepare mixed sand ac. Table 3 shows the particle size composition of the mixed sands a to c.
5) Setting retarder:
-Bicarbonate Na: Sodium bicarbonate (made by Tosoh Corporation).
-Sodium tartrate: L-disodium tartrate (manufactured by Fuso Chemical Industries).
6) Setting accelerator:
・ Sulfate K: Potassium sulfate (manufactured by Ueno Pharmaceutical Co., Ltd.)
-Carbonic acid Li: Lithium carbonate (made by Honjo Chemical Co., Ltd.).
7) Admixture / fluidizing agent: polycarboxylic acid-based fluidizing agent (manufactured by Kao Corporation).
-Thickener: Hydroxyethylmethylcellulose thickener (Marporose MX-30000, manufactured by Matsumoto Yushi Co., Ltd.).
-Antifoaming agent: A polyether type antifoaming agent (manufactured by San Nopco).

(Examples 1 to 3, Comparative Examples 1 and 2)
The hydraulic component, inorganic component, fine aggregate, setting accelerator, fluidizing agent, thickener, antifoaming agent and setting retarder (total amount: 1.5 kg) shown in Table 1 are kneaded using a chemistor. The hydraulic composition was adjusted, and 390 g of water was further added and kneaded for 3 minutes to obtain a mortar. The hydraulic composition and the slurry were adjusted in an atmosphere having a temperature of 30 ° C. and a humidity of 65%.

  Table 2 shows the results of evaluation of SL characteristics, watering time, mortar cured body surface hardness and surface finish using the obtained mortar.

1) In the case of Comparative Example 1 in which only lithium carbonate is used as a setting accelerator and no fine aggregate is blended, the finished surface of the cured body is not finished, and the surface is powdered.
2) In the case of Comparative Example 2 in which lithium carbonate and potassium sulfate are used in combination as a setting accelerator, and fine aggregate not containing fine aggregate is used, the surface of the cured body is pulverized compared to Comparative Example 1. Although improved, it is not possible to suppress the occurrence of none skin.
3) In Comparative Example 3 in which the mixed sand b in which a predetermined amount of fine aggregate was mixed with quartz sand was used as the fine aggregate and only lithium carbonate was used as the setting accelerator, the time to watering was slightly shortened. As for the surface state of the cured body, sufficient improvement is not seen with a finish similar to that of Comparative Example 1.
Further, in the case of Comparative Example 4 in which the mixed sand c is used as the fine aggregate and only potassium sulfate is used as the setting accelerator, the time until watering is greatly shortened, but the hardened body surface hardness is 2 hours later. The surface hardness was completely insufficient (surface hardness after 2 hours = 9). Furthermore, the finished state of the cured body surface could not suppress the occurrence of none skin.
4) As shown in Examples 1 to 4, when fine aggregate is used, mixed sand in which fine aggregate is mixed with silica sand, and when lithium carbonate and potassium sulfate are used together as a setting accelerator, The time until is 30 minutes to 40 minutes, and the hardness of the cured body surface is 20 or more after 1 hour. Further, the surface state of the cured body does not cause surface pulverization, and there is no skin. It was greatly improved. In particular, in Examples 3 and 4, the cured body surface hardness after 1 hour from the slurry preparation is as high as 50 or more, and shows preferable properties for ensuring quick workability. In Example 3, the cured body surface state There was almost no skin phenomenon.

  The self-flowing hydraulic composition of the present invention ensures excellent fluidity and pot life sufficient to facilitate construction work by the effect of addition of a setting retarder, and a particle size in which fine aggregates are blended. By using the fine aggregate having the configuration, slight material separation of the mortar surface layer portion can be further suppressed and eliminated. Furthermore, by using potassium sulfate and lithium salt together as a setting accelerator, the hydration reaction of the hydraulic component proceeds rapidly after the pot life has elapsed, and before subtle material separation of the slurry surface layer becomes apparent. By rapidly advancing the curing, a cured body having excellent horizontal level properties and excellent surface finish can be obtained.

It is a schematic diagram which shows the general | schematic procedure which evaluates the self-leveling property of mortar (slurry) using a SL measuring device.

Claims (7)

A hydraulic composition comprising a hydraulic component made of alumina cement, Portland cement and gypsum, a setting accelerator, and a fine aggregate. The setting accelerator contains potassium sulfate and a lithium salt, and the fine aggregate is fine. A self-flowing hydraulic composition comprising 3 to 20% by mass of fine particles of 30 μm or more to less than 150 μm and 97 to 80% by mass of particles of 150 μm or more to less than 850 μm in 100% by mass of aggregate. The hydraulic component according to claim 1, wherein the hydraulic component is a hydraulic component comprising 20 to 80% by mass of alumina cement, 10 to 55% by mass of Portland cement, and 5 to 50% by mass of gypsum. Composition. The self-flowing hydraulic composition according to claim 1 or 2, wherein potassium sulfate is 0.02 to 1.0 part by mass with respect to 100 parts by mass of the hydraulic component. The hydraulic composition includes a setting retarder, and further includes at least one component selected from a fluidizing agent, a thickener, and an antifoaming agent. The self-flowing hydraulic composition as described. The hydraulic composition contains at least one inorganic component selected from blast furnace slag fine powder, fly ash, and silica fume, and the self-flowing hydraulic property according to any one of claims 1 to 4. Composition. A mortar obtained by kneading the self-flowing hydraulic composition according to any one of claims 1 to 5 and water. The hardening body obtained by hardening the mortar obtained by knead | mixing the self-fluid hydraulic composition of any one of Claims 1-6, and water.

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