JP2013193951A - Self-leveling material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a self-leveling material in which Portland cement is a main component of a hydraulic component, the self-leveling material having excellent workability and hardening properties and, in particular, being capable of achieving stable fluidity even when the amount of unburned carbon in blast-furnace slag fluctuates.SOLUTION: A self-leveling material includes a hydraulic component, blast-furnace slag, fine aggregate, a plasticizer, and a setting modifier, wherein the hydraulic component comprises 20-50 mass% of Portland cement, 25-50 mass% of alumina cement, and 15-45 mass% of gypsum, the fine aggregate contains less than 5 mass% of a coarse-grained fraction having a grain size exceeding 600 μm within 100 mass% of fine aggregate, the amount of unburned carbon contained in the blast-furnace slag is less than 0.18 mass%, and the Blaine specific surface area of the blast-furnace slag is in a range of 2,500-6000 cm/g.

Description

  The present invention relates to a self-leveling material used for construction of a structure such as a concrete floor structure.

  Self-leveling materials are required to have excellent curing characteristics such as excellent workability due to high fluidity and fluidity retention (usable time) and fast curing. In particular, a stable and high fluidity is always required to form a horizontal and smooth floor surface.

  Self-leveling materials can be broadly classified into gypsum and cement, and have a fast setting, can be easily manufactured at low cost, and Patent Document 1 discloses a fine slag powder based on Portland cement. A fast-curing cement composition containing a predetermined amount of alumina cement and anhydrous gypsum and further adding a predetermined amount of a setting regulator 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

  In the cement-based fast-curing cement composition or the self-flowing hydraulic composition, alumina cement or Portland cement is mainly used as the hydraulic component, and blast furnace slag is used. When used as a leveling material, fluidity may be affected by fluctuations in the amount of unburned carbon in the blast furnace slag due to changes in the blast furnace slag lot.

  The present invention is a self-leveling material having Portland cement as a main component of a hydraulic component, and has excellent workability and curing characteristics, in particular, stable fluidity even if the amount of unburned carbon in blast furnace slag varies. It aims at providing the self-leveling material from which (especially outstanding fluidity retention) is obtained.

  In order to solve the above-mentioned problems, the present inventors, in a self-leveling material having Portland cement as a main component of hydraulic component, blended hydraulic component, fine aggregate particle size and water absorption, additive type and As a result of changing the addition conditions and the particle size of the materials used and examining the fluidity in detail, it was found that the desired self-leveling material can be obtained by setting these to certain conditions, and the present invention was completed. .

That is, the present invention is a self-leveling material including a hydraulic component, a blast furnace slag, a fine aggregate, a fluidizing agent, and a setting modifier, and the hydraulic component is 20 to 50 mass of Portland cement. %, Alumina cement 25-50% by mass and gypsum 15-45% by mass, the fine aggregate contains less than 5% by mass of coarse particles having a particle diameter of more than 600 μm in 100% by mass of the fine aggregate, A self-leveling material is provided in which the amount of unburned carbon contained in the blast furnace slag is less than 0.18% by mass, and the blast furnace slag has a brain specific surface area in the range of 2500 to 6000 cm ² / g. Such a self-leveling material has excellent workability and curing characteristics. In particular, even if the amount of unburned carbon in the blast furnace slag varies, stable fluidity and excellent fluidity can be obtained.

  When 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-fluidity of the self-leveling material can be further improved.

  Moreover, the self-leveling material of this invention is the effect of this invention as the said blast furnace slag is 30-200 mass parts and the said fine aggregate is 80-300 mass parts with respect to 100 mass parts of hydraulic components. Can be expressed more reliably.

  According to the present invention, it is possible to provide a self-leveling material having excellent workability and curing characteristics, and in particular, stable fluidity can be obtained even if the amount of unburned carbon in the blast furnace slag varies.

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.

  A preferred embodiment of the self-leveling material of the present invention will be described below.

  The self-leveling material of the present invention includes a hydraulic component, a blast furnace slag, a fine aggregate, a fluidizing agent, and a setting modifier, and the hydraulic component is 20 to 50% by mass of Portland cement and alumina cement. It consists of 25-50 mass% and gypsum 15-45 mass%.

  Here, the Portland cement used for the hydraulic component may be selected from ordinary Portland cement, early-strength Portland cement, ultra-high strength Portland cement, moderately hot Portland cement, low heat Portland cement and sulfate resistant Portland cement. it can. 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.

  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.

  When the hydraulic component is 100% by mass, Portland cement, alumina cement, and gypsum need to be in the above range. This makes it easy to obtain a cured product that is low in material cost, has self-fluidity and rapid curing, and has a small volume change during curing.

  The blending ratio of the hydraulic component is preferably 23 to 45% by mass of Portland cement, 28 to 47% by mass of alumina cement and 18 to 39% by mass of gypsum, more preferably 26 to 37% by mass of Portland cement, 33 to 33% of alumina cement. 45 mass% and gypsum 21 to 37 mass%, particularly preferably Portland cement 27 to 32 mass%, alumina cement 35 to 40 mass% and gypsum 30 to 36 mass%.

In the blast furnace slag according to the present invention, the amount of unburned carbon contained in the blast furnace slag is less than 0.18% by mass, and the brane specific surface area of the blast furnace slag is in the range of 2500 to 6000 cm ² / g. Thus, stable fluidity can be obtained.

  The amount of unburned carbon contained in the above-mentioned blast furnace slag is preferably in the range of more than 0% by mass and less than 0.18% by mass, more preferably in the range of 0.01 to 0.17% by mass, Preferably it is the range of 0.05-0.16 mass%, Most preferably, it is the range of 0.12-0.15 mass%. By including the amount of unburned carbon in the above range, more stable fluidity can be obtained, and in particular, excellent fluidity can be obtained.

The blast furnace slag has a Blaine specific surface area of preferably 2550 to 5000 cm ² / g, more preferably 2800 to 4300 cm ² / g, and still more preferably 3000 to 3700 cm ² / g. Especially preferably, it is the range of 3100-3500 cm < ² > / g. When the specific surface area of the brain is in the above range, more stable fluidity can be obtained, and particularly excellent fluidity can be obtained.

  The fine aggregate according to the present invention contains less than 5% by mass of coarse particles having a particle diameter of more than 600 μm in 100% by mass of the fine aggregate. Such fine aggregates include silica sand, river sand, land sand, sea sand, crushed sand, slag fine aggregate, recycled fine aggregate, waste FCC catalyst, quartz powder, alumina clinker, urethane crushed, EVA It can be suitably selected from resin pulverized products such as foam and foaming resin. In particular, as the fine aggregate, those selected from sands such as quartz sand, river sand, land sand, sea sand, crushed sand, waste FCC catalyst, quartz powder and alumina clinker can be suitably used.

  In the present invention, the particle size of the fine aggregate can be measured 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 particle content in the fine bone agent is preferably 0 to 3% by mass, more preferably 0 to 0.5% by mass, still more preferably 0 to 0.2% by mass, and 01-0.15 mass% is especially preferable.

  In the self-leveling material of the present invention, it is desirable that 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. 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.

  The coarse particle ratio of the fine aggregate is preferably 0.60 to 1.40, more preferably 0.68 to 1.35, still more preferably 0.72 to 1.28, and particularly preferably. 0.74 to 1.25. Further, the lower limit value of the water absorption rate is not particularly limited, and may be 0%. The water absorption of the fine bone agent is preferably 0 to 1.50%, more preferably 0 to 1.40%, still more preferably 0 to 1.30%, and particularly preferably 0.10 to 1.28%.

  In the self-leveling material of the present invention, the blast furnace slag is preferably 30 to 200 parts by mass and the fine aggregate is preferably 80 to 300 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 content of the blast furnace slag is more preferably 45 to 150 parts by mass, further preferably 55 to 100 parts by mass, and 60 to 80 parts by mass with respect to 100 parts by mass of the hydraulic component. Particularly preferred.

  The content of the fine aggregate is more preferably 100 to 250 parts by mass, further preferably 120 to 210 parts by mass, and 140 to 180 parts by mass with respect to 100 parts by mass of the hydraulic component. Is particularly preferred.

  The self-leveling material is usually used with a small amount of mixing water in order to obtain a high-strength cured body while suppressing material separation. Therefore, in the self-leveling material 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 can be appropriately added in a range that does not impair the characteristics, depending on the hydraulic component used, and is preferably 0.01 to 2.0 parts by mass, more preferably 100 parts by mass with respect to the hydraulic component. Can be blended in an amount of 0.02 to 1.0 parts by mass, more preferably 0.05 to 0.80 parts by mass, and particularly preferably 0.08 to 0.40 parts by mass. 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-leveling material of the present invention contains a setting modifier as an essential component in order to adjust the pot life (fluid retention) and fast curing. As the setting modifier, there are a setting accelerator and a setting retarder, and these components and addition amount are appropriately selected according to the blending of the hydraulic component to be used.

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

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

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

  The setting retarder is preferably 0.01 to 2.0 parts by weight, more preferably 0.05 to 1.5 parts by weight, and still more preferably 0.08 to 1 part per 100 parts by weight of the hydraulic component. .2 parts by mass, particularly preferably by using in the range of 0.10 to 1.0 parts by mass, a pot life (handling time) with which suitable fluidity can be obtained can be ensured. Furthermore, by adjusting the addition amount of the setting retarder to the above preferable range, a mortar having self-fluidity (self-leveling property) and having a pot life (handling time) capable of obtaining suitable fluidity is obtained. be able to.

  As the setting accelerator contained in the self-leveling material of the present invention, a known component for promoting setting can be used. For example, lithium salt, aluminum sulfate, and calcium chloride having a setting acceleration effect can be preferably used, and several of these can be used in combination.

  Examples of lithium salts include inorganic lithium salts such as lithium carbonate, lithium chloride, lithium sulfate, lithium nitrate and lithium hydroxide, and organic acid organics such as lithium oxalate, lithium acetate, lithium tartrate, lithium malate and lithium citrate. A lithium salt can be mentioned. In particular, lithium carbonate is preferable from the viewpoint of the setting acceleration effect, availability, and cost.

  As the setting accelerator, those having a particle size that does not interfere with the properties of the self-leveling material are preferably used, and the particle size is preferably 50 μm or less. Particularly when a lithium salt is used, the particle diameter of the lithium salt is preferably 50 μm or less, more preferably 30 μm or less, still more preferably 20 μm or less, and particularly preferably 10 μm or less. When the particle diameter of the lithium salt is larger than the above range, the solubility of the lithium salt becomes small, which is not preferable. In particular, in the pigment addition system, it is noticeable as a large number of fine spots, and the appearance may be impaired.

  The setting accelerator is preferably 0.01 to 1.0 part by weight, more preferably 0.01 to 0.5 part by weight, still more preferably 0.02 to 0 part with respect to 100 parts by weight of the hydraulic component. .3 parts by mass, particularly preferably in the range of 0.03 to 0.2 parts by mass, is preferable because suitable fast-curing properties can be obtained after securing the pot life of the self-leveling material. By adjusting the addition amount of the setting accelerator within the above-mentioned preferable range, a mortar having self-fluidity (self-leveling property) and securing a good pot life is obtained, and a suitable fast-curing property is obtained. Can do.

  In addition to the essential components described above, a thickener, an antifoaming agent, and the like can be appropriately added to the self-leveling material of the present invention within a range that does not impair the characteristics of the present invention.

  Examples of the thickener include commercially available products such as cellulose, protein, latex, and water-soluble polymer. Among these, cellulose thickeners are preferable from the viewpoint of price and availability. Cellulosic thickeners include hydroxyethyl cellulose, hydroxyethyl methyl cellulose, hydroxypropyl methyl cellulose, and the like, which can be used in any combination. It can be expected that the material separation resistance of the self-leveling material is improved by using the thickener.

  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 defoaming effect of the self-leveling material is improved.

  Since the self-leveling material of the present invention has excellent workability (high fluidity, pot life) and curing characteristics (fast curing), it is a school, apartment, convenience store, hospital, veranda, factory, warehouse, parking lot. It can be used for floor foundations and floor finishing materials such as gas stations, kitchens and rooftops. In addition, since the self-leveling material of the present invention can provide stable fluidity even if the amount of unburned carbon in the blast furnace slag varies, it should be used for these applications stably regardless of the production lot or production area. Can do.

  A mortar slurry can be produced by mixing and stirring the self-leveling material of this embodiment with a predetermined amount of water. By adjusting the amount of water added, it is possible to adjust the fluidity of the mortar slurry, the pot life and material separability, the strength of the cured mortar slurry, and the like.

  The mortar slurry has a mass ratio (W / S) of water (W) to the self-leveling material (S), preferably 0.21 to 0.29, more preferably 0.22 to 0.28, still more preferably. It can mix | blend and knead | mix so that it may become 0.23-0.27, Most preferably, it is the range of 0.24-0.26.

  From the viewpoint of the fluidity of the mortar slurry, the flow value of the mortar slurry is preferably 190 mm to 260 mm, more preferably 210 mm to 240 mm, still more preferably 215 to 235 mm, and particularly preferably 220 to 230 mm. . When the flow value is in the above range, the fluidity is suitable, and the cured body surface having high smoothness tends to be obtained.

  Moreover, the self-leveling property of the mortar 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 evaluation of the self-leveling property of a mortar slurry. The SL measuring instrument 10 is made of a synthetic resin and has internal dimensions of 30 mm width × 30 mm height × 750 mm length. And only one end is an open end. The SL measuring instrument 10 includes a filling portion 11 for filling the closed end side with slurry, and a synthetic resin dam plate 12 adjacent to the filling portion 11 for blocking the filled slurry. The filling portion 11 has a capacity with an internal dimension 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 mortar slurry using the above-described SL measuring device. First, as shown to (a) of FIG. 2, the mortar slurry immediately after kneading | mixing is poured so that the filling part 11 may be satisfy | filled. Next, when the weir plate 12 is pulled up, the poured mortar slurry flows out toward the opening end side of the SL measuring device 10 as shown in FIG.

  The time required for the mortar slurry that has flowed out to flow a distance of 200 mm from the mark 13 is the SL flow time (seconds), and the distance from the mark 13 to the end point 14 at which the flow of the mortar slurry stops is the SL value (mm). And By measuring the SL flow time and the SL value by changing the holding time of the mortar slurry in the filling unit 11 (the time from pouring the mortar slurry immediately after kneading to the filling unit 11 until the weir plate 12 is pulled up), The self-leveling property of the mortar slurry can be evaluated.

Immediately after the mortar slurry is poured into the filling section 11 (holding time 0 minutes, hereinafter referred to as “L0”), the weir plate 12 is pulled up, and the flow time (L0) during which the mortar slurry flows through a distance of 200 mm is 30 ° C. Under the environment,
Preferably it is 3 to 35 seconds,
More preferably 5 to 25 seconds,
More preferably, it is 9-20 seconds,
Particularly preferably, it is 10 to 16 seconds.

The SL value (L0) of the mortar slurry is as follows:
Preferably it is 400-600mm,
More preferably, it is 420-550 mm,
More preferably, it is 430-520 mm,
Especially preferably, it is 440-500 mm.

Further, after pouring the mortar slurry into the filling part 11 and holding it for 20 minutes (hereinafter referred to as “L20”), the weir plate 12 is pulled up, and after the flow of the mortar slurry is stopped, from the mark 13 to the end point 14 of the mortar slurry. The SL value (L20), which is the distance of
Preferably it is 200-550 mm,
More preferably, it is 300-500 mm.
More preferably, it is 350-480 mm,
Especially preferably, it is 400-460 mm.

  When the value of L20 is in the above range, it tends to be a mortar slurry excellent in fluidity and fluidity retention (pot life).

Furthermore, after pouring the mortar slurry into the filling part 11 and holding it for 30 minutes (hereinafter referred to as “L30”), the weir plate 12 is pulled up, and after the flow of the mortar slurry is stopped, from the mark 13 to the end point 14 of the mortar slurry SL value (L30), which is the distance of
Preferably it is 100-500mm,
More preferably, it is 200-450 mm,
More preferably, it is 250-400 mm,
Especially preferably, it is 300-350 mm.

  When the value of L30 is in the above range, it tends to be a mortar slurry excellent in fluidity and fluidity retention (pot life) and excellent in separation resistance.

  Mortar slurry begins to harden within 50 minutes to 2 hours after the completion of construction, depending on the temperature and humidity conditions at the construction site (water pulling: the surface water of the mortar slurry disappears), and with the progress of curing The surface hardness of the cured body increases, and the water content on the surface of the cured body tends to decrease.

The shore hardness of the surface of the cured body after 1.5 hours formed by casting the mortar slurry and finishing the surface of the mortar slurry under an environment of a temperature of 30 ° C.
Preferably it is 1 or more,
More preferably, it is 5 or more,
More preferably, it is 8 or more,
Particularly preferably, it is 10 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. When the shore hardness of the surface of the mortar slurry is within the above range, it is easy to form a concrete floor structure in a short period of time after the mortar slurry construction (laying and finishing) is completed Become.

  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] (TERNAL CC, manufactured by Kerneos, Blaine specific surface area 3340 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) Blast furnace slag [BFS]
Table 2 shows the amount of unburned carbon and the specific surface area of the brane of the blast furnace slag used.

Here, the “unburned carbon amount” is obtained by dissolving blast furnace slag with hydrochloric acid, measuring the carbon amount of the remaining residue by the method prescribed in JIS R 1603, and obtaining the carbon amount (unit: Mass%). “Blaine specific surface area” refers to the specific surface area (unit: cm ² / g) measured according to the physical test method for cement specified in JIS R 5201.

(3) Fine aggregate Silica sand [S] (coarse fraction having a particle diameter of more than 600 μm = 0.12% by mass, coarse grain rate = 1.20%, water absorption = 0.79%)
(4) Fluidizing agent Polycarboxylic acid based fluidizing agent (Kao Corporation)
(5) Setting retarder A: Na tartrate (manufactured by Fuso Chemical Industries)
B: Bicarbonate Na (manufactured by Tosoh Corporation)
(6) Setting accelerator Lithium carbonate (particle size 3.5 ± 1 μm, manufactured by Honjo Chemical Co., Ltd.)
(7) Thickener Cellulosic thickener (Hydroxyethylmethylcellulose, viscosity of 2% aqueous solution of thickener at 20 ° C. = 28,800 mPa · s, manufactured by Matsumoto Yushi Co., Ltd.)
The viscosity of the cellulosic thickener was measured for an aqueous solution (20 ° C.) containing 2% by mass of the thickener using a B-type viscometer (Toki Sangyo Co., Ltd. digital viscometer, DVL-B type). In this measurement, the rotational speed was 12 rpm, and the rotor No. 4 was used.

  Table 3 shows the blending ratio of the above materials for obtaining a self-leveling material.

[Preparation of mortar]
The above materials (total amount: 1.5 kg) were mixed at a blending ratio shown in Table 2 to prepare a self-leveling material. Next, 375 g of water was added to the obtained self-leveling material and kneaded for 3 minutes using a chemistor to obtain a mortar slurry. The mortar slurry was prepared in a thermostatic chamber at a temperature of 30 ° 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 30 ° C. Table 4 shows the measurement results.

[Self-leveling (SL) value]
Immediately after pouring the mortar slurry immediately after kneading into the filling part 11 of the SL measuring device 10 shown in FIG. 1 (holding time 0 minute), the weir plate 12 was pulled up and flowed out from the filling part 11 as shown in FIG. After the flow of the mortar slurry stopped, the distance from the gauge point (dam plate installation portion) 13 to the end point 14 at which the flow of the mortar slurry stopped was measured as the SL value (L0). Further, the SL flow time (L0) required for the mortar slurry to flow a distance of 200 mm from the mark 13 was measured. Similarly, the dam plate 12 is pulled up 20 minutes after filling with the mortar slurry, and after stopping the flow of the mortar slurry, the distance from the gauge point 13 to the end point 14 of the mortar slurry is measured as an SL value (L20). 30 minutes after the slurry filling, the weir plate 12 was pulled up, and after stopping the flow of the mortar slurry, the distance from the gauge point 13 to the end point 14 of the mortar slurry was measured as the SL value (L30). Table 4 shows the measurement results.

[Watering time]
After pouring the prepared mortar slurry into a synthetic resin container having internal dimensions of width 130 x length 190 x height 17 mm to a thickness of 15 mm, the surface water of the cured body disappears with the start of condensation (light The time when the reflection was lost and clouded) was measured as the watering time. Table 4 shows the measurement results.

[surface hardness]
After a predetermined elapsed time after mortar slurry placement, the hardness of the hardened surface (Shore hardness) is determined by using a spring type hardness tester type D type (manufactured by Ueshima Seisakusho Co., Ltd.) at any four locations. The average value of the readings of the spring type hardness tester type D gauge was defined as the surface hardness at that time. In this example and comparative example, the Shore hardness after 1.5 hours was measured. Table 4 shows the measurement results.

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

  As shown in Examples 1 to 5, the mortar slurry prepared using the self-leveling material of the present invention exhibited excellent flow value and SL value (fluidity and fluidity retention). In particular, Example 3 and Example 4 were 300 mm or more even in the SL value (L30) after 30 minutes and were excellent in fluidity retention, while Comparative Example 1 and Comparative Example 2 were SL after 20 minutes. The value (L20) was 0 mm, and the fluidity retention was not sufficient. In Examples 1 to 5, the Shore hardness after 1.5 hours was 10 or more, excellent curing characteristics (fast curing), and surface flatness was also good.

  From Examples 1 to 5 of the present invention, the mixing ratio of the hydraulic component, the particle size of the fine aggregate and the water absorption rate are made appropriate, and by having other essential components, it has excellent workability and curing characteristics, It was confirmed that a self-leveling material capable of obtaining stable fluidity can be obtained when the amount of unburned carbon in the blast furnace slag is less than 0.18% by mass. Thereby, it can use for these uses stably regardless of a manufacturing lot and a manufacturing area.

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

Claims (3)

A self-leveling material comprising a hydraulic component, blast furnace slag, fine aggregate, a fluidizing agent, and a setting modifier,
The hydraulic component is composed of 20-50% by weight of Portland cement, 25-50% by weight of alumina cement and 15-45% by weight of gypsum,
The fine aggregate includes less than 5% by mass of coarse particles having a particle diameter of more than 600 μm in 100% by mass of the fine aggregate,
A self-leveling material, wherein the amount of unburned carbon contained in the blast furnace slag is less than 0.18% by mass, and the brain specific surface area of the blast furnace slag is in the range of 2500 to 6000 cm ² / g.   The self-leveling material according to claim 1, wherein the fine aggregate has a coarse particle ratio in a range of 0.60 to 1.40 and a water absorption rate of 1.6% or less.   The self-leveling material according to claim 1 or 2, wherein the blast furnace slag is 30 to 200 parts by mass and the fine aggregate is 80 to 300 parts by mass with respect to 100 parts by mass of the hydraulic component.

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