JP7099799B2 - Fluidizer Composition for Soil Cement, Cement Suspension and Soil Cement - Google Patents

Description

The present invention relates to soil cement applied to a ground improvement method, an underground continuous wall method, a foundation pile method, a backfill method, etc., and a cement-based suspension (“cement milk” or “cement slurry”) used for the preparation thereof. (Also also referred to as) and a fluidizing agent composition for soil cement (hereinafter, also referred to as “fluidizing agent for soil cement”).

Soil cement is generally produced by mixing cement (including a cement-based solidifying material) and water to prepare a cement-based suspension, and then mixing the cement-based suspension with soil. It is a mixture and, if necessary, contains bentonite or a water-soluble polymer in order to suppress breathing and the like. Soil cement is used for ground improvement method, underground continuous wall method, foundation pile method, backfill method, etc. In these methods, solidified material is formed after a certain period of time after soil cement is prepared. Let me. In the soil cement used in these construction methods, the amount of cement-based suspension injected or the amount of waste soil cement (hereinafter referred to as "mud soil") generated is reduced, and the fluidity of the soil cement is improved for construction. In recent years, a fluidizing agent for soil cement has been added to improve efficiency.

The following techniques are known as fluidizing agents for soil cement.
Patent Document 1 discloses a fluidizing agent for soil cement, which comprises a low molecular weight polymer having a carboxylic acid or a monovalent salt thereof as a main constituent monomer unit and an alkali metal carbonate.
Patent Document 2 includes (a) at least one polymer and copolymer selected from ethylenically unsaturated monocarboxylic acid and ethylenically unsaturated dicarboxylic acid, and at least one water-soluble salt thereof. An additive for a ground-improved cement composition containing a coalescing component and (b) a polymer salt component containing at least one of (b) water-soluble polymer salts is disclosed.
Patent Document 3 discloses an additive for soil cement containing a specific phosphoric acid ester-based polymer. Then, an additive in which a phosphoric acid ester-based polymer is used in combination with sodium hydrogen carbonate, potassium hydrogen carbonate or sodium carbonate is described.
Further, Patent Document 4 describes a composition containing a copolymer (X) composed of a unit of (meth) acrylic acid alkaline earth metal salt (A) and a unit of a copolymerization monomer (B). Meta) Acrylic acid alkaline earth metal salt (A) unit is 20 to 85 mol%, copolymerization monomer (B) unit is 15 to 80 mol%, and a soil cement dispersant is disclosed. And it is stated that sodium carbonate may be further contained.

Japanese Unexamined Patent Publication No. 2000-169209 Japanese Unexamined Patent Publication No. 2004-175989 Japanese Unexamined Patent Publication No. 2007-169547 Japanese Unexamined Patent Publication No. 2013-139369

Of the above construction methods, in the underground continuous wall construction method and the foundation pile construction method such as the steel pipe pile construction method, stress materials such as H-shaped steel and steel pipes are built after the soil cement is created in the original ground (underground). .. In this case, from the start of drilling to the completion of building the stress material, the soil cement needs to have an appropriate fluidity so that the stress material can be placed in a predetermined position by the weight of the stress material. Regarding the fluidity of such soil cement, until about 10 years ago, most of the work was done if the table flow value of the soil cement was maintained at 150 mm or more (fluidity retention time) for about 2 to 4 hours. Was able to proceed without any problems.
However, recently, in urban areas, due to the following reasons (a) to (d), the number of construction works requesting the extension of the liquidity retention time is increasing.
A) As an environmental measure (consideration for noise and vibration) of neighboring residents, construction is interrupted during lunch time and construction is canceled after 5 or 6 in the evening. B) Construction-related vehicles are brought in due to traffic congestion and traffic restrictions around the site. Delay in carrying out (interruption of construction due to delay)
C) Delay in construction time per process (from the start of drilling to the completion of stress material construction) due to the interruption of construction in a) and b) above d) Due to the effective utilization of narrow land in urban areas and the development of public infrastructure, etc. Deepening

For construction with construction time restrictions in the evening or deep construction, the construction of one process (from the start of drilling to the completion of building stress material) is completed, and when the same process is performed next time, the construction will be done on that day. If it was judged that the work could not be completed by the time required for the work to be completed, the construction was abandoned even if the time was 2:00 pm. The reason is that if the construction is carried over to the next day, the soil cement prepared the previous day loses its fluidity and solidifies and must be re-drilled (delayed construction period, excess of materials used and generated mud). In addition, when it is judged that the construction of one process (from the start of drilling to the completion of building stress material) is in time for the work end regulation time, drilling is started, and due to sudden troubles or work delays, Even if one process cannot be carried out on that day, re-drilling will be required the next day (delayed construction period, excess of materials used and generated mud).
Furthermore, if the construction time of one process is often delayed, the stress material cannot be built together after the construction of multiple processes, considering the fluidity retention time of the soil cement. In this case, the stress material built in the previous construction sways due to the influence of the stirring blade and high-pressure air for stirring at the time of drilling, and as a result, the building accuracy Decreases.

The subject of the present invention is a cement-based suspension capable of setting the time (fluidity retention time) from the time when the soil cement is prepared until the table flow value becomes less than 150 mm to 6 hours or more, and the soil for giving the cement-based suspension. The present invention is to provide a fluidizing agent composition for cement.

The present inventors have prepared a fluidizing agent composition for soil cement using a water-soluble polymer as a main agent, an alkali metal carbonate, and an alkali metal bicarbonate in combination, and the alkali metal carbonate and the alkali metal carbonate with respect to the water-soluble polymer. The effect of the content of the alkali metal bicarbonate on the fluidity of the soil cement, that is, the effect of the content of the alkali metal bicarbonate on the dispersion retention of the cement and soil in the soil cement was studied diligently, and the present invention was completed.
The present invention is shown below.
[1] A fluidizing agent composition for soil cement containing (A) a water-soluble polymer, (B) an alkali metal carbonate, and (C) an alkali metal bicarbonate, the above-mentioned alkali metal carbonate ( The contents of B) and the alkali metal bicarbonate (C) are 10 to 1300 parts by mass and 10 to 1300 parts by mass, respectively, with respect to 100 parts by mass of the water-soluble polymer (A). The total content of the alkali metal carbonate (B) and the alkali metal bicarbonate (C) is 100 to 1500 parts by mass with respect to 100 parts by mass of the water-soluble polymer (A). A characteristic fluidizing agent composition for soil cement.
[2] The water-soluble polymer (A) is a structural unit derived from a monomer having an ethylenically unsaturated bond, contains a structural unit having a COO bond, and has a weight average molecular weight of 50,000 or less. The fluidizing agent composition for a soil cement according to [1].
[3] The fluidizing agent composition for soil cement according to the above [1] or [2], wherein the water-soluble polymer (A) is a polymer containing a structural unit derived from acrylic acid or a salt thereof.
[4] The soil cement according to any one of the above [1] to [3], wherein the alkali metal carbonate (B) is sodium carbonate and the alkali metal bicarbonate (C) is sodium bicarbonate. For fluidizing agent composition.
[5] The fluidizing agent composition for soil cement according to any one of the above [1] to [3], which is used in the ground improvement method, the underground continuous wall method, the foundation pile method or the backfill method.
[6] A cement-based suspension comprising the soil cement fluidizing agent composition according to any one of the above [1] to [5], cement, and water.
[7] A soil cement containing the cement-based suspension according to the above [6] and soil.
In the present specification, the weight average molecular weight (hereinafter, also referred to as “Mw”) of the polymer is a standard sodium polyacrylate equivalent value measured by gel permeation chromatography (hereinafter, also referred to as “GPC”). Is. The description of "(meth) acrylic" means acrylic and methacrylic. Further, the description of "(co) polymer" means a homopolymer and a copolymer.

The fluidizing agent composition for soil cement, the cement suspension and the soil cement of the present invention are suitable for the ground improvement method, the underground continuous wall method, the foundation pile method, the backfill method and the like.
According to the fluidizing agent composition for soil cement and the cement-based suspension of the present invention, the time (fluidity retention time) from the time when the soil cement is prepared until the table flow value becomes less than 150 mm is 2 to 4. It is possible to provide a soil cement having a fluidity retention time of 6 hours or more, which is about an hour, which is longer than that of a conventional soil cement, that is, a soil cement having excellent dispersion retention of cement and soil. Therefore, even if the construction method described above takes a long time, defects can be suppressed.

In the present invention, soil excavated from the original ground (underground) or soil as it is in the original ground (underground) is mixed with a cement-based suspension to form soil cement, whereby soil cement is formed. A ground improvement method for forming ground with improved strength, soil excavated from the original ground (underground), or soil that remains in the original ground (underground) is mixed with a cement-based suspension. After forming the soil cement, a stress material (H-type steel, I-type steel, etc.) that will be a reinforcing material for the continuous underground wall is built while the soil cement has fluidity. ) And the soil-based suspension are mixed to form soil cement, which is integrated with the steel pipe to construct a synthetic pile. And a cement-based suspension are mixed to form soil cement, which is preferably applied to a backfilling method or the like in which the soil cement is backfilled in the ground.

The fluidizing agent composition for soil cement of the present invention is a composition containing (A) a water-soluble polymer, (B) an alkali metal carbonate metal salt, and (C) an alkali metal bicarbonate metal salt in a specific ratio. It is a composition which may contain other components (described later), if necessary.

The water-soluble polymer (A) is not particularly limited as long as it is soluble in water, and contains, for example, a structural unit derived from a monomer having an ethylenically unsaturated bond (vinyl-based monomer). Vinyl-based (co) polymers or salts thereof (hereinafter, simply referred to as "vinyl-based (co) polymers"), polyalkylene glycols, polysaccharides and the like can be used. The fluidizing agent composition for soil cement of the present invention may contain only one kind of water-soluble polymer (A), or may contain two or more kinds.

（式中、Ｍは、水素原子、アルカリ金属原子、アルカリ土類金属原子又はＮＨ_４であり、Ｒは、炭化水素基である。）
上記ビニル系（共）重合体に含まれる親水性基は、分子末端に位置していてよいし、側鎖に含まれていてもよい。
上記ビニル系（共）重合体は、上記親水性基の少なくとも１つを有するビニル系単量体に由来する構造単位（親水性基含有構造単位）を含むことが好ましい。この場合、親水性基含有構造単位の含有割合は、ビニル系（共）重合体を構成するすべての構造単位の合計を１００質量％とした場合に、好ましくは４０質量％以上、より好ましくは５０質量％以上であり、更に好ましくは７０質量％以上である。尚、上限値は１００質量％である。 The vinyl-based (co) polymer preferably contains at least one of the hydrophilic groups shown below.

(In the formula, M is a hydrogen atom, an alkali metal atom, an alkaline earth metal atom or NH ₄ , and R is a hydrocarbon group.)
The hydrophilic group contained in the vinyl-based (co) polymer may be located at the end of the molecule or may be contained in the side chain.
The vinyl-based (co) polymer preferably contains a structural unit (hydrophilic group-containing structural unit) derived from a vinyl-based monomer having at least one of the hydrophilic groups. In this case, the content ratio of the hydrophilic group-containing structural units is preferably 40% by mass or more, more preferably 50, when the total of all the structural units constituting the vinyl-based (co) polymer is 100% by mass. It is by mass or more, more preferably 70% by mass or more. The upper limit is 100% by mass.

Further, the vinyl-based (co) polymer preferably contains a COO bond. In this case, not only the polymer containing -COOM exemplified as the hydrophilic group, but also the polymer containing a hydrophilic group other than -COOM and a COO bond is preferable. The COO bond means those exemplified below.

The COO bond may be directly bonded to a carbon atom constituting the main chain derived from the ethylenically unsaturated bond, or may be contained in the side chain.

（式中、Ｒ^１は、炭素原子数１～３の炭化水素基であり、Ｒ^２は、炭素原子数１～２０の、置換又は非置換の２価の炭化水素基であり、Ｒ^３は、炭素原子数１～４０の炭化水素基であり、Ｍ^１、Ｍ^２及びＭ^３は、互いに独立して、水素原子、アルカリ金属原子、アルカリ土類金属原子又はＮＨ_４である。）

（式中、Ｒ^１は、炭素原子数１～３の炭化水素基であり、Ｒ^３は、炭素原子数１～４０の炭化水素基であり、Ｒ^４は、炭素原子数２～４の、置換又は非置換の２価の炭化水素基であり、Ｍ^１、Ｍ^２及びＭ^３は、互いに独立して、水素原子、アルカリ金属原子、アルカリ土類金属原子又はＮＨ_４であり、ｎは、１～２０の整数である。）

（式中、Ｒ^１は、炭素原子数１～３の炭化水素基であり、Ｒ^２は、炭素原子数１～２０の、置換又は非置換の２価の炭化水素基であり、Ｒ^４は、炭素原子数２～４の、置換又は非置換の２価の炭化水素基であり、Ｍ^４は、水素原子、アルカリ金属原子、アルカリ土類金属原子又はＮＨ_４であり、ｎは、１～２０の整数である。）

（式中、Ｒ^１は、炭素原子数１～３の炭化水素基であり、Ｒ^５は、炭素原子数２～４の、置換又は非置換の２価の炭化水素基であり、Ｒ^６は、炭素原子数１～４０の炭化水素基であり、Ｒ^７は、炭素原子数１～２０の、置換又は非置換の２価の炭化水素基であり、Ｒ^８は、炭素原子数２～４の、置換又は非置換の２価の炭化水素基であり、Ｒ^９は、炭素原子数１～４０の炭化水素基であり、Ｍ^４は、水素原子、アルカリ金属原子、アルカリ土類金属原子又はＮＨ_４であり、ｎは、１～２０の整数である。） Examples of the vinyl-based monomer giving the hydrophilic group-containing structural unit containing the COO bond include acrylic acid and its salt (sodium acrylate, potassium acrylate, magnesium acrylate, calcium acrylate, etc.), methacrylic acid and its salt. (Sodium methacrylate, potassium methacrylate, etc.), etacrilic acid and its salts, crotonic acid and its salts, cinnamic acid and its salts, maleic acid and its salts (sodium maleate, etc.), methyl maleic acid and its salts, dimethyl maleine Acid and its salt, phenylmaleic acid and its salt, maleic acid half ester and its salt, fumaric acid and its salt (sodium fumarate, etc.), fumaric acid half ester and its salt, itaconic acid and its salt (sodium itaconate, etc.) ), Itaconic acid half ester and its salt, citraconic acid and its salt, citraconic acid half ester and its salt, etc., monomers having a -COMM group; acids such as maleic anhydride, itaconic anhydride, citraconic anhydride, etc. Monomer having an anhydride group; 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, ( 3-Hydroxybutyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, polyethylene glycol mono (meth) acrylate, polypropylene glycol mono (meth) acrylate, di-2-hydroxyethyl maleate, di-4-maleate Monomer having a hydroxyl group such as hydroxybutyl, di-2-hydroxypropyl itaconate; 2- (meth) acryloyloxyethyl phosphate, 2- (meth) acryloyloxypropyl phosphate, 2- (meth) acryloyloxy 3 -Chloropropyl phosphate, phenyl-2- (meth) acryloyloxyethyl phosphate, phosphate ester of polyethylene glycol mono (meth) acrylate, phosphate ester of polypropylene glycol mono (meth) acrylate, etc., the following general formula (1), Phosphorus atom-containing monomer represented by (2), (3) or (4); 1- (meth) acryloyloxyetanesulfonic acid and its salt, 2- (meth) acryloyloxyetanesulfonic acid and its salt, 2- (Meta) acryloyloxypropanesulfonic acid and its salt, 3- (meth) acryloyloxypropanesulfonic acid and its salt, 2- (meth) ac Liloyloxybutane sulfonic acid and its salt, 3- (meth) acryloyloxybutane sulfonic acid and its salt, 4- (meth) acryloyloxybutane sulfonic acid and its salt, 2-hydroxysulfopropyl (meth) acrylate and its salt , 3- (meth) acryloxy-2- (poly) oxyethylene ether propanesulfonic acid and its salt, 3- (meth) acryloxy-2- (poly) oxypropylene ether propanesulfonic acid and its salt, etc. Sulfur atom-containing monomer represented by (5) or (6); sulfur atom-containing monomer represented by the following general formulas (7), (8), (9) or (10) can be mentioned. ..

(In the formula, R ¹ is a hydrocarbon group having 1 to 3 carbon atoms, R ² is a substituted or unsubstituted divalent hydrocarbon group having 1 to 20 carbon atoms, and R ³ is. , A hydrocarbon group having 1 to 40 carbon atoms, and M ¹ , M ² and M ³ are independent of each other, a hydrogen atom, an alkali metal atom, an alkaline earth metal atom or NH ₄ .

(In the formula, R ¹ is a hydrocarbon group having 1 to 3 carbon atoms, R ³ is a hydrocarbon group having 1 to 40 carbon atoms, and R ⁴ is a hydrocarbon group having 2 to 4 carbon atoms. Substituted or unsubstituted divalent hydrocarbon groups, M ¹ , M ² and M ³ are independent of each other, a hydrogen atom, an alkali metal atom, an alkaline earth metal atom or NH ₄ , where n is. It is an integer from 1 to 20.)

(In the formula, R ¹ is a hydrocarbon group having 1 to 3 carbon atoms, R ² is a substituted or unsubstituted divalent hydrocarbon group having 1 to 20 carbon atoms, and R ⁴ is. , Substituent or unsubstituted divalent hydrocarbon group having 2 to 4 carbon atoms, M ⁴ is a hydrogen atom, an alkali metal atom, an alkaline earth metal atom or NH ₄ , and n is 1 to 1. It is an integer of 20.)

(In the formula, R ¹ is a hydrocarbon group having 1 to 3 carbon atoms, R ⁵ is a substituted or unsubstituted divalent hydrocarbon group having 2 to 4 carbon atoms, and R ⁶ is. , 1 to 40 carbon atoms, R ⁷ is a substituted or unsubstituted divalent hydrocarbon group having 1 to 20 carbon atoms, and R ⁸ is a 2 to 4 carbon atoms. , Substituted or unsubstituted divalent hydrocarbon group, R ⁹ is a hydrocarbon group having 1 to 40 carbon atoms, and M ⁴ is a hydrogen atom, an alkali metal atom, an alkaline earth metal atom or It is NH ₄ , and n is an integer of 1 to 20.)

As the vinyl-based monomer constituting the vinyl-based (co) polymer and giving a hydrophilic group-containing structural unit containing a COO bond, a monomer having a -COMM group is preferable, and acrylic acid or a salt thereof is particularly preferable. preferable.

Examples of the vinyl-based monomer that does not contain COO bonds but gives a hydrophilic group-containing structural unit include vinyl alcohol, acrylamide, methacrylamide, dimethylacrylamide, diethylacrylamide, Nn-propylacrylamide, and N-isopropylacrylamide. N-methylol acrylamide, N-methylol methacrylamide, N- (2-hydroxyethyl) acrylamide, N- (2-hydroxyethyl) methacrylamide, N, N-dimethylaminoethyl acrylamide, N, N-dimethylaminoethyl methacrylamide , N-Vinyl-2-pyrrolidone, N-vinyl-4-pyrrolidone, N-vinyl-3-methylpyrrolidone, N-vinyl-5-methylpyrrolidone, N-vinyl-3-benzylpyrrolidone, N-vinyl-3, Examples thereof include 3,5-trimethylpyrrolidone, N-acrylloylpipezirin, N-acrylloylpyrrolidin, vinylformamide, vinylacetamide and the like.

The vinyl-based (co) polymer may further contain a structural unit having no hydrophilic group. Examples of the vinyl-based monomer giving such a structural unit include methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, isopropyl (meth) acrylate, n-butyl (meth) acrylate, and isopropyl. (Meta) acrylate, tert-butyl (meth) acrylate, pentyl (meth) acrylate, hexyl (meth) acrylate, n-octyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, nonyl (meth) acrylate, decyl (meth) ) Acrylate, Isodecyl (meth) acrylate, Lauryl (meth) acrylate, Tetradecyl (meth) acrylate, Octadecyl (meth) acrylate, Isostearyl (meth) acrylate, Cyclopentyl (meth) acrylate, Cyclohexyl (meth) acrylate, tert-butylcyclohexyl (Meta) acrylate, isobornyl (meth) acrylate, 2,2,4-trimethylcyclohexyl (meth) acrylate, phenyl (meth) acrylate, benzyl (meth) acrylate, naphthyl (meth) acrylate, methoxyethyl (meth) acrylate, methoxy Propyl (meth) acrylate, ethoxyethyl (meth) acrylate, ethoxypropyl (meth) acrylate, vinylamine, allylamine, aminostyrene, 2-aminoethyl (meth) acrylate, vinylmethylamine, allylmethylamine, methylaminostyrene, tert- Butylaminoethyl (meth) acrylate, tetramethylpiperidyl (meth) acrylate, dimethylaminoethyl (meth) acrylate, diethylaminoethyl (meth) acrylate, pentamethylpiperidyl (meth) acrylate, N-ethylmorpholino (meth) acrylate, dimethylamino Styrene, styrene, α-methylstyrene, o-methylstyrene, p-methylstyrene, β-methylstyrene, ethylstyrene, p-tert-butylstyrene, vinyltoluene, vinylxylene, vinylnaphthalene, ethylene, propylene, butene, penten , Hexen, octene, etc.

Examples of the polyalkylene glycol include polyethylene glycol, polypropylene glycol, polyethylene polypropylene glycol, polyethylene polybutylene glycol and the like.

Examples of the polysaccharide include nonionic cellulose, anionic cellulose, cationic cellulose and the like.

The weight average molecular weight (Mw) of the water-soluble polymer (A) is preferably 50,000 or less, more preferably 30,000 or less, still more preferably 30,000 or less, from the viewpoint of the fluidity of the soil cement, the strength when the soil cement is solidified, and the like. It is 20000 or less. The lower limit of the weight average molecular weight (Mw) is usually 2000.

The water-soluble polymer (A) according to the present invention contains a structural unit derived from a monomer having a −COM group because the fluidity of the soil cement, the strength when the soil cement is solidified, and the like are more excellent. A vinyl-based (co) polymer is preferable, and a vinyl-based (co) polymer containing a structural unit derived from acrylic acid or a salt thereof is particularly preferable. When the water-soluble polymer (A) is a vinyl-based (co) polymer containing a structural unit derived from acrylic acid or a salt thereof, the acrylic acid or a salt thereof contained in the vinyl-based (co) polymer The ratio of the derived structural unit is preferably 50% by mass or more, more preferably 70% by mass or more, and further preferably 80% by mass or more.

The alkali metal carbonate (B) is preferably a water-soluble compound. Examples of the water-soluble alkali metal carbonate include sodium carbonate, potassium carbonate, lithium carbonate and the like. Of these, sodium carbonate is particularly preferable from the viewpoints of fluidity of soil cement, strength when soil cement is solidified, cost effectiveness, and the like. The fluidizing agent composition for soil cement of the present invention may contain only one kind of alkali metal carbonate (B), or may contain two or more kinds.

The content of the alkali metal carbonate (B) contained in the fluidizing agent composition for soil cement of the present invention is the above-mentioned water-soluble polymer from the viewpoint of the fluidity of the soil cement, the strength when the soil cement is solidified, and the like. (A) 10 to 1300 parts by mass, preferably 10 to 1000 parts by mass, and more preferably 10 to 730 parts by mass with respect to 100 parts by mass.

Further, the bicarbonate alkali metal salt (C) is preferably a water-soluble compound. Examples of the water-soluble bicarbonate alkali metal salt include sodium hydrogen carbonate, potassium hydrogen carbonate and the like. Of these, sodium hydrogencarbonate is particularly preferable from the viewpoints of fluidity of soil cement, strength when soil cement is solidified, cost effectiveness, and the like. The fluidizing agent composition for soil cement of the present invention may contain only one type of alkali metal bicarbonate (C), or may contain two or more types.

The content of the alkali metal bicarbonate (C) contained in the fluidizing agent composition for soil cement of the present invention is the above-mentioned water-soluble weight from the viewpoint of the fluidity of the soil cement, the strength when the soil cement is solidified, and the like. It is 10 to 1300 parts by mass, preferably 10 to 1000 parts by mass, and more preferably 10 to 730 parts by mass with respect to 100 parts by mass of the combined (A).

The mass ratio of the alkali metal carbonate (B) and the alkali metal bicarbonate (C) contained in the fluidizing agent composition for soil cement of the present invention is the fluidity of the soil cement, the strength when the soil cement is solidified, and the like. From the viewpoint of, it is preferably 85:15 to 15:85, and more preferably 70:30 to 30:70.

Further, in the fluidizing agent composition for soil cement of the present invention, the total content of the alkali metal carbonate (B) and the alkali metal bicarbonate (C) is the fluidity of the soil cement and the solidification of the soil cement. From the viewpoint of strength, cost effectiveness, etc., the amount is 100 to 1500 parts by mass, preferably 120 to 1200 parts by mass, and more preferably 150 to 900 parts by mass with respect to 100 parts by mass of the water-soluble polymer (A). ..

The fluidizing agent composition for soil cement of the present invention comprises the quality (clay, silt, sand, gravel) of the soil (target soil) of the original ground and its physical properties (wet density, water content ratio, liquid limit, etc.), and further. Depending on the construction conditions (standard formulation: cement amount, water / cement ratio, injection amount, required quality, etc.) in each construction method, hardening retarders for cement such as gluconate, triethanolamine, saccharose, and hardening promotion Agents, lignin sulfonic acid compounds, naphthalene compounds and other water reducing agents or AE water reducing agents and fluidizing agents, AE agents, foaming agents, foaming agents, defoaming agents, thickeners, separation reducing agents, rust preventives, Conventionally known admixtures such as shrinkage reducing agents, swelling agents, antifreezing agents, and pozolan-based admixtures can be contained.

The properties of the fluidizing agent composition for soil cement of the present invention are not particularly limited, and may be either a solid mixture or a liquid dispersion.

The fluidizing agent composition for soil cement of the present invention can be produced by mixing raw material components. As for the alkali metal carbonate and the alkali metal bicarbonate, these may be used as they are, or the sesqui alkali metal carbonate which is a compound salt may be used. Further, in the case of a liquid dispersion, for example, it can be produced by using an aqueous solution obtained by dissolving a part or all of the raw material components in water in advance.

The cement-based suspension of the present invention contains the above-mentioned fluidizing agent for soil cement of the present invention, cement, and water. That is, the cement-based suspension of the present invention contains a water-soluble polymer (A), an alkali metal carbonate (B), an alkali metal bicarbonate (C), cement, and water.

The cement is not particularly limited as long as it is hardened by a hydration reaction, and is conventionally known Portland cement (normal, fast-strength, ultra-fast-strength, moderate heat, low heat, sulfate-resistant as shown in JIS R5210). Salt), blast furnace cement (A, B, C type shown in JIS R5211), silica cement (A, B, C type shown in JIS R5212), fly ash cement (shown in JIS R5213). Portland-based mixed cement such as (A, B, C), etc., and environment-friendly cement (eco-cement) manufactured from urban waste incineration ash or sewage sludge incineration ash as a raw material can be used. can.
In the present invention, blast furnace cement is preferable, and blast furnace cement type B is preferable because the fluidity of the soil cement and the strength when the soil cement is solidified are excellent.
For loam soil, humus soil, etc., which are difficult to obtain strength after solidification, a cement-based solidifying material commercially available for special soil can be used.

The content of cement contained in the cement-based suspension of the present invention is preferably 500 to 50,000 parts by mass, and more preferably 1,000 to 25,000 parts by mass with respect to 100 parts by mass of the water-soluble polymer (A). ..

The water-cement ratio (hereinafter referred to as "W / C ratio") in the cement-based suspension of the present invention is the quality (clay, silt, sand, gravel) and its physical properties (clay, silt, sand, gravel) of the soil (target soil) of the original ground. It is appropriately selected depending on the wetting density, water content ratio, liquid limit, etc.), but is preferably 60 to 350%.

The cement-based suspension of the present invention may contain other components such as bentonite, wood-knot clay, kaolin-based clay mineral, lime-based solidifying material, neutral solidifying material, weak alkaline solidifying material, and light-baked magnesia. ..

The cement-based suspension of the present invention can be produced by mixing the above-mentioned fluidizing agent for soil cement of the present invention, cement, and water. Further, for example, a part of the fluidizing agent for soil cement of the present invention may be mixed with cement in advance, and then the rest of the fluidizing agent for soil cement of the present invention may be mixed with water. ..

The soil cement of the present invention contains the above-mentioned cement-based suspension of the present invention and soil. That is, the soil cement of the present invention contains a water-soluble polymer (A), an alkali metal carbonate (B), an alkali metal bicarbonate (C), a cement, water, and soil.

The soil cement of the present invention can be obtained by mixing a cement-based suspension with soil in the original ground (underground), and the quality of soil (target soil) (clay, silt, sand, gravel) and Cement type depending on its physical properties (wet density, water content ratio, liquid limit, etc.) and construction conditions (standard formulation: cement amount, water / cement ratio, injection amount, required quality, etc.) in each construction method. The amount of suspension and soil used is set.
Generally, the total solid content of the essential components of the fluidizer for soil cement contained in the cement-based suspension is preferably 2 to 40 kg per 1 m ³ of soil. If it is less than 2 kg, no effect can be obtained due to lack of essential ingredients. On the other hand, when the weight exceeds 40 kg, the desired fluidity retention time cannot be obtained, the soil cement does not solidify rapidly, and the strength is often significantly reduced.

The total amount of essential ingredients is shown concretely. When the soil is cohesive soil, the total solid content of the essential components of the fluidizing agent for soil cement per 1 m ³ of soil is preferably 8 to 40 kg.
When the soil is sandy soil, the total solid content of the essential components of the fluidizing agent for soil cement per 1 m ³ of soil is preferably 4 to 20 kg.
When the soil is gravel soil, the total solid content of the essential components of the fluidizing agent for soil cement per 1 m ³ of soil is preferably 2 to 10 kg.
When the target soil is composed of three soils, cohesive soil, sandy soil, and gravel soil, the total solid content of the essential components is the preferable total solid content of each of the above soils and the composition ratio of each soil ( It may be calculated by weighted averaging with the volume ratio). For example, when the mixing ratio of each soil is cohesive soil: sandy soil: gravel soil = 1: 1: 1, the amount is 4.7 to 23.3 kg per 1 m ³ of soil.

Regarding the fluidity of the soil cement of the present invention, the table flow value according to JIS R5201 is preferably 200 mm or more from the viewpoint of building by the weight of the stress material and self-leveling property.
The time (fluidity retention time) from the time when the soil cement of the present invention is prepared until the table flow value becomes less than 150 mm can be arbitrarily controlled by preferably 6 hours or more, more preferably 8 hours or more. ..
Further, the time (fluidity retention time) from the time when the soil cement of the present invention is prepared until the table flow value becomes less than 200 mm is preferably controlled arbitrarily within 5 hours or more, more preferably 7 hours or more. Can be done.

The soil cement of the present invention can be made in the original ground (underground) or on the ground. Since the soil cement of the present invention has the above-mentioned fluidity retention time, it is particularly useful when it is formed in the original ground (underground), and is particularly useful in the deep mixing treatment method, the middle layer mixing treatment method, and the like. It is suitable for foundation pile construction methods such as ground improvement construction method; underground continuous wall construction method; steel pipe pile construction method. In addition, the backfilling method for creating soil cement on the ground is also suitable for construction that requires high filling property (self-leveling property, high fluidity).

Hereinafter, the present invention will be specifically described with reference to Examples. However, the present invention is not limited to the following examples. In the following, parts and% are based on mass unless otherwise specified.

1. 1. Raw Material of Fluidizer for Soil Cement (1) Aqueous Solution of Water-Soluble Polymer 43.0% Aqueous Solution (W1) of Sodium Polyacrylate (A1) with Mw of 6000 by GPC or Sodium Polyacrylate (A2) with Mw of 19000 ) 42.1% aqueous solution (W2) was used.
[GPC measurement conditions]
Equipment: HLC8020 system (manufactured by Tosoh)
Column: G4000PWxl, G3000PWxl and G2500PWxl (manufactured by Tosoh Corporation) are linked Eluent: 0.1M-NaCl + phosphate buffer (pH 7)
Flow rate: 0.8 mL / min Column temperature: 40 ° C
Detector: RI
Standard substance: Sodium polyacrylate

(2) Alkali carbonate metal salt powder Sodium carbonate powder or potassium carbonate powder was used.
(3) Alkalicarbonate metal salt powder Sodium bicarbonate (sodium hydrogencarbonate) powder or potassium bicarbonate (potassium hydrogencarbonate) powder was used.

2. 2. Manufacture and evaluation of fluidizer for soil cement, cement-based suspension and soil cement Using the above raw materials, a fluidizer for soil cement was manufactured, and the fluidizer for soil cement obtained and the following Okizumi viscosity Cement-based suspensions and soil cements were produced using soil or burial cohesive soil.
-Alluvial cohesive soil (P): Alluvial cohesive soil / Okizumi cohesive soil (Q) with a wet density of 1.817 g / cm ³ and a water content of 36.5% collected at the site of Shinsago 3-chome, Koizumi-ku, Tokyo. Alluvial cohesive soil / Koizumi cohesive soil (R) with a wet density of 1.706 g / cm ³ and a water content of 47.1% collected at Katsudoki 1-chome, Chuo-ku, Tokyo: Yanagibashi, Tsukuba City, Ibaraki Prefecture Alluvial cohesive soil with a wet density of 1.700 g / cm ³ and a water content of 49.6% (S): Wet density collected at Koizumiminami, Shiorai City, Ibaraki Prefecture Alluvial cohesive soil with 1.693 g / cm ³ and a water content of 49.9%

Example 1
5.0 kg of an aqueous sodium polyacrylate solution (W1), 6.25 kg of sodium carbonate powder, and 1.25 kg of sodium bicarbonate powder were mixed to obtain a fluidizing agent for soil cement (S11). The composition of this fluidizing agent for soil cement (S11) is that when the content of sodium polyacrylate (A1) is 100 parts, the content of sodium carbonate is 291 parts and the content of sodium bicarbonate is 291 parts. 58 copies (see Table 1).
Next, 12.5 kg (solid content 9.65 kg) of this fluidizing agent for soil cement (S11), 160 kg of blast furnace cement B type, and 368 kg of water were mixed to obtain a cement-based suspension (C11). After that, the content of sodium polyacrylate (A1) is 2.15 kg, the content of sodium carbonate is 6.25 kg, and the content of sodium bicarbonate is 1.25 kg in 1 m ³ of the Okizumi cohesive soil (P). As described above, a cement-based suspension (C11) was added, and these were mixed to obtain a soil cement (L11).

The table flow value of the obtained soil cement (L11) was measured according to JIS R5201. That is, the prepared soil cement was filled in the flow cone installed in the center of the flow table, and the soil cement was pierced 15 times using a stick. Immediately, the flow cone is removed in the vertical direction, and a falling motion is applied 15 times in 15 seconds. This average value was used as the table flow value (TF).
In addition, the time from the preparation of soil cement (L11) until the table flow value became less than 150 mm or less than 200 mm was determined.
The above results are shown in Table 1.

Example 2
5.0 kg of an aqueous sodium polyacrylate solution (W1), 5.0 kg of sodium carbonate powder, and 2.5 kg of sodium bicarbonate powder were mixed to obtain a fluidizing agent for soil cement (S12). The composition of this fluidizing agent for soil cement (S12) is that when the content of sodium polyacrylate (A1) is 100 parts, the content of sodium carbonate is 233 parts and the content of sodium bicarbonate is 233 parts. There are 116 copies (see Table 1).
Next, 12.5 kg (solid content 9.65 kg) of this fluidizing agent for soil cement (S12), 160 kg of blast furnace cement B type, and 368 kg of water were mixed to obtain a cement-based suspension (C12). After that, the content of sodium polyacrylate (A1) is 2.15 kg, the content of sodium carbonate is 5.0 kg, and the content of sodium bicarbonate is 2.5 kg in 1 m ³ of the Okizumi cohesive soil (P). As described above, a cement-based suspension (C12) was added, and these were mixed to obtain a soil cement (L12).
For the obtained soil cement (L12), the table flow value was measured in the same manner as in Example 1. In addition, the time from the preparation of soil cement (L12) until the table flow value became less than 150 mm or less than 200 mm was determined.
The above results are shown in Table 1.

Example 3
5.0 kg of an aqueous sodium polyacrylate solution (W1), 3.75 kg of sodium carbonate powder, and 3.75 kg of sodium bicarbonate powder were mixed to obtain a fluidizing agent for soil cement (S13). The composition of this fluidizing agent for soil cement (S13) is that when the content of sodium polyacrylate (A1) is 100 parts, the content of sodium carbonate is 174 parts and the content of sodium bicarbonate is 174 parts. 174 copies (see Table 1).
Next, 12.5 kg (solid content 9.65 kg) of this fluidizing agent for soil cement (S13), 160 kg of blast furnace cement B type, and 368 kg of water were mixed to obtain a cement-based suspension (C13). After that, the content of sodium polyacrylate (A1) is 2.15 kg, the content of sodium carbonate is 3.75 kg, and the content of sodium bicarbonate is 3.75 kg in 1 m ³ of the Okizumi cohesive soil (P). As described above, a cement-based suspension (C13) was added, and these were mixed to obtain a soil cement (L13).
For the obtained soil cement (L13), the table flow value was measured in the same manner as in Example 1. In addition, the time from the preparation of soil cement (L13) until the table flow value became less than 150 mm or less than 200 mm was determined.
The above results are shown in Table 1.

Example 4
5.0 kg of an aqueous sodium polyacrylate solution (W1), 2.5 kg of sodium carbonate powder, and 5.0 kg of sodium bicarbonate powder were mixed to obtain a fluidizing agent for soil cement (S14). The composition of this fluidizing agent for soil cement (S14) is that when the content of sodium polyacrylate (A1) is 100 parts, the content of sodium carbonate is 116 parts and the content of sodium bicarbonate is 116 parts. 233 copies (see Table 1).
Next, 12.5 kg (solid content 9.65 kg) of this fluidizing agent for soil cement (S14), 160 kg of blast furnace cement B type, and 368 kg of water were mixed to obtain a cement-based suspension (C14). After that, the content of sodium polyacrylate (A1) is 2.15 kg, the content of sodium carbonate is 2.5 kg, and the content of sodium bicarbonate is 5.0 kg in 1 m ³ of the Okizumi cohesive soil (P). As described above, a cement-based suspension (C14) was added, and these were mixed to obtain a soil cement (L14).
For the obtained soil cement (L14), the table flow value was measured in the same manner as in Example 1. In addition, the time from the preparation of soil cement (L14) until the table flow value became less than 150 mm or less than 200 mm was determined.
The above results are shown in Table 1.

Example 5
5.0 kg of an aqueous sodium polyacrylate solution (W1), 1.25 kg of sodium carbonate powder, and 6.25 kg of sodium bicarbonate powder were mixed to obtain a fluidizing agent for soil cement (S15). The composition of this fluidizing agent for soil cement (S15) is that when the content of sodium polyacrylate (A1) is 100 parts, the content of sodium carbonate is 58 parts and the content of sodium bicarbonate is 58 parts. 291 copies (see Table 1).
Next, 12.5 kg (solid content 9.65 kg) of this fluidizing agent for soil cement (S15), 160 kg of blast furnace cement B type, and 368 kg of water were mixed to obtain a cement-based suspension (C15). After that, the content of sodium polyacrylate (A1) is 2.15 kg, the content of sodium carbonate is 1.25 kg, and the content of sodium bicarbonate is 6.25 kg in 1 m ³ of the Okizumi cohesive soil (P). As described above, a cement-based suspension (C15) was added, and these were mixed to obtain a soil cement (L15).
For the obtained soil cement (L15), the table flow value was measured in the same manner as in Example 1. In addition, the time from the preparation of soil cement (L15) until the table flow value became less than 150 mm or less than 200 mm was determined.
The above results are shown in Table 1.

Example 6
9.0 kg of an aqueous sodium polyacrylate solution (W1), 6.75 kg of sodium carbonate powder, and 6.75 kg of sodium bicarbonate powder were mixed to obtain a fluidizing agent for soil cement (S16). The composition of this fluidizing agent for soil cement (S16) is that when the content of sodium polyacrylate (A1) is 100 parts, the content of sodium carbonate is 174 parts and the content of sodium bicarbonate is 174 parts. 174 copies (see Table 1).
Next, 22.5 kg (solid content 17.37 kg) of this fluidizing agent for soil cement (S16), 160 kg of blast furnace cement B type, and 368 kg of water were mixed to obtain a cement-based suspension (C16). After that, the content of sodium polyacrylate (A1) is 3.87 kg, the content of sodium carbonate is 6.75 kg, and the content of sodium bicarbonate is 6.75 kg in 1 m ³ of the Okizumi cohesive soil (P). As described above, a cement-based suspension (C16) was added, and these were mixed to obtain a soil cement (L16).
For the obtained soil cement (L16), the table flow value was measured in the same manner as in Example 1. In addition, the time from the preparation of soil cement (L16) until the table flow value became less than 150 mm or less than 200 mm was determined.
The above results are shown in Table 1.

Example 7
9.0 kg of an aqueous sodium polyacrylate solution (W1), 6.75 kg of sodium carbonate powder, and 6.75 kg of potassium bicarbonate powder were mixed to obtain a fluidizing agent for soil cement (S17). The composition of this fluidizing agent for soil cement (S17) is that when the content of sodium polyacrylate (A1) is 100 parts, the content of sodium carbonate is 174 parts and the content of potassium bicarbonate is 174 parts. There are 174 copies (see Table 1).
Next, 22.5 kg (solid content 17.37 kg) of this fluidizing agent for soil cement (S17), 160 kg of blast furnace cement B type, and 368 kg of water were mixed to obtain a cement-based suspension (C17). After that, the content of sodium polyacrylate (A1) is 3.87 kg, the content of sodium carbonate is 6.75 kg, and the content of potassium bicarbonate is 6.75 kg in 1 m ³ of the Okizumi cohesive soil (P). As described above, a cement-based suspension (C17) was added, and these were mixed to obtain soil cement (L17).
For the obtained soil cement (L17), the table flow value was measured in the same manner as in Example 1. In addition, the time from the preparation of soil cement (L17) until the table flow value became less than 150 mm or less than 200 mm was determined.
The above results are shown in Table 1.

Example 8
9.0 kg of an aqueous sodium polyacrylate solution (W1), 6.75 kg of potassium carbonate powder, and 6.75 kg of potassium bicarbonate powder were mixed to obtain a fluidizing agent for soil cement (S18). The composition of this fluidizing agent for soil cement (S18) is that the content of potassium carbonate is 174 parts and the content of potassium bicarbonate is 174 parts when the content of sodium polyacrylate (A1) is 100 parts. There are 174 copies (see Table 1).
Next, 22.5 kg (solid content 17.37 kg) of this fluidizing agent for soil cement (S18), 160 kg of blast furnace cement B type, and 368 kg of water were mixed to obtain a cement-based suspension (C18). After that, the content of sodium polyacrylate (A1) is 3.87 kg, the content of potassium carbonate is 6.75 kg, and the content of potassium bicarbonate is 6.75 kg in 1 m ³ of the Okizumi cohesive soil (P). As described above, a cement-based suspension (C18) was added, and these were mixed to obtain a soil cement (L18).
For the obtained soil cement (L18), the table flow value was measured in the same manner as in Example 1. Further, the time from the preparation of the soil cement (L18) until the table flow value became less than 150 mm or less than 200 mm was determined.
The above results are shown in Table 1.

Example 9
9.0 kg of an aqueous sodium polyacrylate solution (W1), 6.75 kg of potassium carbonate powder, and 6.75 kg of sodium bicarbonate powder were mixed to obtain a fluidizing agent for soil cement (S19). The composition of this fluidizing agent for soil cement (S19) is that the content of potassium carbonate is 174 parts and the content of sodium bicarbonate is 174 parts when the content of sodium polyacrylate (A1) is 100 parts. There are 174 copies (see Table 1).
Next, 22.5 kg (solid content 17.37 kg) of this fluidizing agent for soil cement (S19), 160 kg of blast furnace cement B type, and 368 kg of water were mixed to obtain a cement-based suspension (C19). After that, the content of sodium polyacrylate (A1) is 3.87 kg, the content of potassium carbonate is 6.75 kg, and the content of sodium bicarbonate is 6.75 kg in 1 m ³ of the Okizumi clay (P). As described above, a cement-based suspension (C19) was added, and these were mixed to obtain a soil cement (L19).
For the obtained soil cement (L19), the table flow value was measured in the same manner as in Example 1. In addition, the time from the preparation of soil cement (L19) until the table flow value became less than 150 mm or less than 200 mm was determined.
The above results are shown in Table 1.

Example 10
5.0 kg of an aqueous sodium polyacrylate solution (W2), 3.75 kg of sodium carbonate powder, and 3.75 kg of sodium bicarbonate powder were mixed to obtain a fluidizing agent for soil cement (S20). The composition of this fluidizing agent for soil cement (S20) is that when the content of sodium polyacrylate (A2) is 100 parts, the content of sodium carbonate is 178 parts and the content of sodium bicarbonate is 178 parts. There are 178 copies (see Table 1).
Next, 12.5 kg (solid content 9.61 kg) of this fluidizing agent for soil cement (S20), 160 kg of blast furnace cement B type, and 368 kg of water were mixed to obtain a cement-based suspension (C20). After that, the content of sodium polyacrylate (A2) is 2.11 kg, the content of sodium carbonate is 3.75 kg, and the content of sodium bicarbonate is 3.75 kg in 1 m ³ of the Okizumi cohesive soil (P). As described above, a cement-based suspension (C20) was added, and these were mixed to obtain a soil cement (L20).
For the obtained soil cement (L20), the table flow value was measured in the same manner as in Example 1. Further, the time from the preparation of the soil cement (L20) until the table flow value became less than 150 mm or less than 200 mm was determined.
The above results are shown in Table 1.

Comparative Example 1
5.0 kg of an aqueous solution of sodium polyacrylate (W1) and 7.5 kg of sodium carbonate were mixed to obtain a fluidizing agent for soil cement (S21). The composition of this fluidizing agent for soil cement (S21) is that the content of sodium carbonate is 349 parts when the content of sodium polyacrylate (A1) is 100 parts (see Table 1).
Next, 12.5 kg (solid content 9.65 kg) of this fluidizing agent for soil cement (S21), 160 kg of blast furnace cement B type, and 368 kg of water were mixed to obtain a cement-based suspension (C21). After that, the cement-based suspension (C21) was added so that the content of sodium polyacrylate (A1) was 2.15 kg and the content of sodium carbonate was 9.65 kg in 1 m ³ of the Okizumi cohesive soil (P). Was added and these were mixed to obtain soil cement (L21).
For the obtained soil cement (L21), the table flow value was measured in the same manner as in Example 1. Further, the time from the preparation of the soil cement (L21) until the table flow value became less than 150 mm or less than 200 mm was determined.
The above results are shown in Table 1.

Example 11
7.0 kg of an aqueous sodium polyacrylate solution (W1), 7.5 kg of sodium carbonate powder, and 7.5 kg of sodium bicarbonate powder were mixed to obtain a fluidizing agent for soil cement (S22). The composition of this fluidizing agent for soil cement (S22) is that when the content of sodium polyacrylate (A1) is 100 parts, the content of sodium carbonate is 249 parts and the content of sodium bicarbonate is 249 parts. There are 249 copies (see Table 2).
Next, 22.00 kg (solid content 18.01 kg) of this fluidizing agent for soil cement (S22), 170 kg of blast furnace cement B type, and 442 kg of water were mixed to obtain a cement-based suspension (C22). After that, the content of sodium polyacrylate (A1) is 3.01 kg, the content of potassium carbonate is 7.5 kg, and the content of sodium bicarbonate is 7.5 kg in 1 m ³ of the Okizumi clay (Q). As described above, a cement-based suspension (C22) was added, and these were mixed to obtain a soil cement (L22).
For the obtained soil cement (L22), the table flow value was measured in the same manner as in Example 1. In addition, the time from the preparation of soil cement (L22) until the table flow value became less than 150 mm or less than 200 mm was determined.
The above results are shown in Table 2.

Comparative Example 2
7.0 kg of an aqueous sodium polyacrylate solution (W1) and 10.5 kg of sodium carbonate powder were mixed to obtain a fluidizing agent for soil cement (S23). The composition of this fluidizing agent for soil cement (S23) is that the content of sodium carbonate is 349 parts when the content of sodium polyacrylate (A1) is 100 parts (see Table 2).
Next, 17.50 kg (solid content 13.51 kg) of this fluidizing agent for soil cement (S23), 170 kg of blast furnace cement B type, and 442 kg of water were mixed to obtain a cement-based suspension (C23). Then, the cement-based suspension (C23) so that the content of sodium polyacrylate (A1) is 3.01 kg and the content of sodium carbonate is 10.5 kg in the above-mentioned Okizumi cohesive soil (Q) 1 m ³ . Was added and these were mixed to obtain soil cement (L23).
For the obtained soil cement (L23), the table flow value was measured in the same manner as in Example 1. In addition, the time from the preparation of soil cement (L23) until the table flow value became less than 150 mm or less than 200 mm was determined.
The above results are shown in Table 2.

Comparative Example 3
7.0 kg of an aqueous solution of sodium polyacrylate (W1) and 15.0 kg of sodium carbonate powder were mixed to obtain a fluidizing agent for soil cement (S24). The composition of the fluidizing agent for soil cement (S24) is that the content of sodium carbonate is 498 parts when the content of sodium polyacrylate (A1) is 100 parts (see Table 2).
Next, 22.00 kg (solid content 18.01 kg) of this fluidizing agent for soil cement (S24), 170 kg of blast furnace cement B type, and 442 kg of water were mixed to obtain a cement-based suspension (C24). After that, the cement-based suspension (C24) was added so that the content of sodium polyacrylate (A1) was 3.01 kg and the content of sodium carbonate was 15.0 kg in 1 m ³ of the Okizumi cohesive soil (Q). Was added and these were mixed to obtain soil cement (L24).
For the obtained soil cement (L24), the table flow value was measured in the same manner as in Example 1. In addition, the time from the preparation of soil cement (L24) until the table flow value became less than 150 mm or less than 200 mm was determined.
The above results are shown in Table 2.

Comparative Example 4
7.0 kg of an aqueous sodium polyacrylate solution (W1) and 10.5 kg of sodium bicarbonate powder were mixed to obtain a fluidizing agent (S25) for soil cement. The composition of this fluidizing agent for soil cement (S25) is that the content of sodium bicarbonate is 349 parts when the content of sodium polyacrylate (A1) is 100 parts (see Table 2).
Next, 17.50 kg (solid content 13.51 kg) of this fluidizing agent for soil cement (S25), 170 kg of blast furnace cement B type, and 442 kg of water were mixed to obtain a cement-based suspension (C25). After that, the cement-based suspension (C25) so that the content of sodium polyacrylate (A1) is 3.01 kg and the content of sodium bicarbonate is 10.5 kg in the above-mentioned Okizumi cohesive soil (Q) 1 m ³ . ) Was added and these were mixed to obtain a soil cement (L25).
For the obtained soil cement (L25), the table flow value was measured in the same manner as in Example 1. In addition, the time from the preparation of soil cement (L25) until the table flow value became less than 150 mm or less than 200 mm was determined.
The above results are shown in Table 2.

Comparative Example 5
7.0 kg of an aqueous sodium polyacrylate solution (W1) and 15.0 kg of sodium bicarbonate powder were mixed to obtain a fluidizing agent for soil cement (S26). The composition of this fluidizing agent for soil cement (S26) is that the content of sodium bicarbonate is 498 parts when the content of sodium polyacrylate (A1) is 100 parts (see Table 2).
Next, 22.00 kg (solid content 18.01 kg) of this fluidizing agent for soil cement (S26), 170 kg of blast furnace cement B type, and 442 kg of water were mixed to obtain a cement-based suspension (C26). Then, the cement-based suspension (C26) so that the content of sodium polyacrylate (A1) is 3.01 kg and the content of sodium bicarbonate is 15.0 kg in the above-mentioned Okizumi cohesive soil (Q) 1 m ³ . ) Was added and these were mixed to obtain a soil cement (L26).
For the obtained soil cement (L26), the table flow value was measured in the same manner as in Example 1. In addition, the time from the preparation of soil cement (L26) until the table flow value became less than 150 mm or less than 200 mm was determined.
The above results are shown in Table 2.

Example 12
7.0 kg of an aqueous sodium polyacrylate solution (W1), 10.5 kg of sodium carbonate powder, and 10.5 kg of sodium bicarbonate powder were mixed to obtain a fluidizing agent for soil cement (S27). The composition of this fluidizing agent for soil cement (S27) is that when the content of sodium polyacrylate (A1) is 100 parts, the content of sodium carbonate is 349 parts and the content of sodium bicarbonate is 349 parts. 349 copies (see Table 3).
Next, 28.00 kg (solid content 24.01 kg) of this fluidizing agent for soil cement (S27), 170 kg of blast furnace cement B type, and 442 kg of water were mixed to obtain a cement-based suspension (C27). After that, the content of sodium polyacrylate (A1) was 3.01 kg, the content of potassium carbonate was 10.5 kg, and the content of sodium bicarbonate was 10.5 kg in 1 m ³ of the above-mentioned Kozumi cohesive soil (R). Sodium cement (L27) was obtained by adding a cement-based suspension (C27) and mixing them.
For the obtained soil cement (L27), the table flow value was measured in the same manner as in Example 1. In addition, the time from the preparation of soil cement (L27) until the table flow value became less than 150 mm or less than 200 mm was determined.
The above results are shown in Table 3.

Example 13
7.0 kg of an aqueous sodium polyacrylate solution (W1), 10.5 kg of sodium carbonate powder, and 5.25 kg of sodium bicarbonate powder were mixed to obtain a fluidizing agent for soil cement (S28). The composition of this fluidizing agent for soil cement (S28) is that when the content of sodium polyacrylate (A1) is 100 parts, the content of sodium carbonate is 349 parts and the content of sodium bicarbonate is 349 parts. 174 copies (see Table 3).
Next, 22.75 kg (solid content 18.76 kg) of this fluidizing agent for soil cement (S28), 170 kg of blast furnace cement B type, and 442 kg of water were mixed to obtain a cement-based suspension (C28). After that, the content of sodium polyacrylate (A1) was 3.01 kg, the content of potassium carbonate was 10.5 kg, and the content of sodium bicarbonate was 5.25 kg in 1 m ³ of the above-mentioned Kozumi cohesive soil (R). Sodium cement (L28) was obtained by adding a cement-based suspension (C28) and mixing them.
For the obtained soil cement (L28), the table flow value was measured in the same manner as in Example 1. In addition, the time from the preparation of soil cement (L28) until the table flow value became less than 150 mm or less than 200 mm was determined.
The above results are shown in Table 3.

Example 14
7.0 kg of an aqueous sodium polyacrylate solution (W1), 10.0 kg of sodium carbonate powder, and 10.0 kg of sodium bicarbonate powder were mixed to obtain a fluidizing agent for soil cement (S29). The composition of this fluidizing agent for soil cement (S29) is that when the content of sodium polyacrylate (A1) is 100 parts, the content of sodium carbonate is 332 parts and the content of sodium bicarbonate is 332 parts. 332 copies (see Table 3).
Next, 27.00 kg (solid content 23.01 kg) of this fluidizing agent for soil cement (S29), 170 kg of blast furnace cement B type, and 442 kg of water were mixed to obtain a cement-based suspension (C29). After that, the content of sodium polyacrylate (A1) was 3.01 kg, the content of potassium carbonate was 10.0 kg, and the content of sodium bicarbonate was 10.0 kg in 1 m ³ of the above-mentioned Kozumi cohesive soil (R). Sodium cement (L29) was obtained by adding a cement-based suspension (C29) and mixing them.
For the obtained soil cement (L29), the table flow value was measured in the same manner as in Example 1. In addition, the time from the preparation of soil cement (L29) until the table flow value became less than 150 mm or less than 200 mm was determined.
The above results are shown in Table 3.

Example 15
14.0 kg of an aqueous sodium polyacrylate solution (W1), 14.0 kg of sodium carbonate powder, and 7.0 kg of sodium bicarbonate powder were mixed to obtain a fluidizing agent for soil cement (S30). The composition of this fluidizing agent for soil cement (S30) is that when the content of sodium polyacrylate (A1) is 100 parts, the content of sodium carbonate is 233 parts and the content of sodium bicarbonate is 233 parts. There are 116 copies (see Table 3).
Next, 35.00 kg (solid content 27.02 kg) of this fluidizing agent for soil cement (S30), 170 kg of blast furnace cement B type, and 442 kg of water were mixed to obtain a cement-based suspension (C30). After that, the content of sodium polyacrylate (A1) was 6.02 kg, the content of potassium carbonate was 14.0 kg, and the content of sodium bicarbonate was 7.0 kg in 1 m ³ of the above-mentioned Kozumi cohesive soil (R). Sodium cement (L30) was obtained by adding a cement-based suspension (C30) and mixing them.
For the obtained soil cement (L30), the table flow value was measured in the same manner as in Example 1. Further, the time from the preparation of the soil cement (L30) until the table flow value became less than 150 mm or less than 200 mm was determined.
The above results are shown in Table 3.

Example 16
16.5 kg of an aqueous sodium polyacrylate solution (W1), 5.5 kg of sodium carbonate powder, and 5.5 kg of sodium bicarbonate powder were mixed to obtain a fluidizing agent for soil cement (S31). The composition of this fluidizing agent for soil cement (S31) is that when the content of sodium polyacrylate (A1) is 100 parts, the content of sodium carbonate is 78 parts and the content of sodium bicarbonate is 78 parts. There are 78 copies (see Table 3).
Next, 27.50 kg (solid content 18.10 kg) of this fluidizing agent for soil cement (S31), 170 kg of blast furnace cement B type, and 442 kg of water were mixed to obtain a cement-based suspension (C31). After that, the content of sodium polyacrylate (A1) was 7.10 kg, the content of potassium carbonate was 5.5 kg, and the content of sodium bicarbonate was 5.5 kg in 1 m ³ of the above-mentioned Kozumi cohesive soil (R). Sodium cement (L31) was obtained by adding a cement-based suspension (C31) and mixing them.
For the obtained soil cement (L31), the table flow value was measured in the same manner as in Example 1. Further, the time from the preparation of the soil cement (L31) until the table flow value became less than 150 mm or less than 200 mm was determined.
The above results are shown in Table 3.

Example 17
17.5 kg of an aqueous sodium polyacrylate solution (W1), 8.75 kg of sodium carbonate powder, and 8.75 kg of sodium bicarbonate powder were mixed to obtain a fluidizing agent for soil cement (S32). The composition of this fluidizing agent for soil cement (S32) is that when the content of sodium polyacrylate (A1) is 100 parts, the content of sodium carbonate is 116 parts and the content of sodium bicarbonate is 116 parts. There are 116 copies (see Table 3).
Next, 35.000 kg (solid content 25.03 kg) of this fluidizing agent for soil cement (S32), 170 kg of blast furnace cement B type, and 442 kg of water were mixed to obtain a cement-based suspension (C32). After that, the content of sodium polyacrylate (A1) was 7.53 kg, the content of potassium carbonate was 8.75 kg, and the content of sodium bicarbonate was 8.75 kg in 1 m ³ of the above-mentioned Kozumi cohesive soil (R). Sodium cement (L32) was obtained by adding a cement-based suspension (C32) and mixing them.
For the obtained soil cement (L32), the table flow value was measured in the same manner as in Example 1. Further, the time from the preparation of the soil cement (L32) until the table flow value became less than 150 mm or less than 200 mm was determined.
The above results are shown in Table 3.

Comparative Example 6
7.0 kg of an aqueous solution of sodium polyacrylate (W1) and 10.5 kg of sodium carbonate powder were mixed to obtain a fluidizing agent for soil cement (S33). The composition of this fluidizing agent for soil cement (S33) is that the content of sodium carbonate is 349 parts when the content of sodium polyacrylate (A1) is 100 parts (see Table 3).
Next, 17.50 kg (solid content 13.51 kg) of this fluidizing agent for soil cement (S33), 170 kg of blast furnace cement B type, and 442 kg of water were mixed to obtain a cement-based suspension (C33). Then, the cement-based suspension (C33) so that the content of sodium polyacrylate (A1) is 3.01 kg and the content of potassium carbonate is 10.5 kg in the above-mentioned Kozumi cohesive soil (R) 1 m ³ . ) Was added and these were mixed to obtain soil cement (L33).
For the obtained soil cement (L33), the table flow value was measured in the same manner as in Example 1. In addition, the time from the preparation of soil cement (L33) until the table flow value became less than 150 mm or less than 200 mm was determined.
The above results are shown in Table 3.

Example 18
5.0 kg of an aqueous solution of sodium polyacrylate (W1), 3.75 kg of sodium carbonate powder, and 3.75 kg of sodium bicarbonate powder were mixed to obtain a fluidizing agent for soil cement (S34). The composition of this fluidizing agent for soil cement (S34) is that when the content of sodium polyacrylate (A1) is 100 parts, the content of sodium carbonate is 174 parts and the content of sodium bicarbonate is 174 parts. 174 copies (see Table 4).
Next, 12.5 kg (solid content 9.65 kg) of this fluidizing agent for soil cement (S34), 160 kg of blast furnace cement B type, and 480 kg of water were mixed to obtain a cement-based suspension (C34). After that, the content of sodium polyacrylate (A1) was 2.15 kg, the content of sodium carbonate was 3.75 kg, and the content of sodium bicarbonate was 3.75 kg in 1 m ³ of the above-mentioned Kozumi cohesive soil (S). Sodium cement (L34) was obtained by adding a cement-based suspension (C34) and mixing them.
For the obtained soil cement (L34), the table flow value was measured in the same manner as in Example 1. In addition, the time from the preparation of soil cement (L34) until the table flow value became less than 150 mm or less than 200 mm was determined.
The above results are shown in Table 4.

Example 19
5.0 kg of an aqueous sodium polyacrylate solution (W1), 7.5 kg of sodium carbonate powder, and 7.5 kg of sodium bicarbonate powder were mixed to obtain a fluidizing agent for soil cement (S35). The composition of this fluidizing agent for soil cement (S35) is that when the content of sodium polyacrylate (A1) is 100 parts, the content of sodium carbonate is 349 parts and the content of sodium bicarbonate is 349 parts. 349 copies (see Table 4).
Next, 20.0 kg (solid content 17.15 kg) of this fluidizing agent for soil cement (S35), 160 kg of blast furnace cement B type, and 480 kg of water were mixed to obtain a cement-based suspension (C35). After that, the content of sodium polyacrylate (A1) was 2.15 kg, the content of sodium carbonate was 7.5 kg, and the content of sodium bicarbonate was 7.5 kg in 1 m ³ of the above-mentioned Kozumi cohesive soil (S). Sodium cement (L35) was obtained by adding a cement-based suspension (C35) and mixing them.
For the obtained soil cement (L35), the table flow value was measured in the same manner as in Example 1. In addition, the time from the preparation of soil cement (L35) until the table flow value became less than 150 mm or less than 200 mm was determined.
The above results are shown in Table 4.

Example 20
5.0 kg of an aqueous sodium polyacrylate solution (W1), 10.0 kg of sodium carbonate powder, and 10.0 kg of sodium bicarbonate powder were mixed to obtain a fluidizing agent for soil cement (S36). The composition of this fluidizing agent for soil cement (S36) is that the content of sodium carbonate is 465 parts and the content of sodium bicarbonate is 465 parts when the content of sodium polyacrylate (A1) is 100 parts. There are 465 copies (see Table 4).
Next, 25.0 kg (solid content 22.15 kg) of this fluidizing agent for soil cement (S36), 160 kg of blast furnace cement B type, and 480 kg of water were mixed to obtain a cement-based suspension (C36). After that, the content of sodium polyacrylate (A1) was 2.15 kg, the content of sodium carbonate was 10.0 kg, and the content of sodium bicarbonate was 10.0 kg in 1 m ³ of the above-mentioned Kozumi cohesive soil (S). Sodium cement (L36) was obtained by adding a cement-based suspension (C36) and mixing them.
For the obtained soil cement (L36), the table flow value was measured in the same manner as in Example 1. In addition, the time from the preparation of soil cement (L36) until the table flow value became less than 150 mm or less than 200 mm was determined.
The above results are shown in Table 4.

Example 21
4.0 kg of an aqueous sodium polyacrylate solution (W1), 10.0 kg of sodium carbonate powder, and 10.0 kg of sodium bicarbonate powder were mixed to obtain a fluidizing agent for soil cement (S37). The composition of this fluidizing agent for soil cement (S37) is that when the content of sodium polyacrylate (A1) is 100 parts, the content of sodium carbonate is 581 parts and the content of sodium bicarbonate is 581 parts. 581 copies (see Table 4).
Next, 24.0 kg (solid content 21.72 kg) of this fluidizing agent for soil cement (S37), 160 kg of blast furnace cement B type, and 480 kg of water were mixed to obtain a cement-based suspension (C37). After that, the content of sodium polyacrylate (A1) was 1.72 kg, the content of sodium carbonate was 10.0 kg, and the content of sodium bicarbonate was 10.0 kg in 1 m ³ of the above-mentioned Kozumi cohesive soil (S). Sodium cement (L37) was obtained by adding a cement-based suspension (C37) and mixing them.
For the obtained soil cement (L37), the table flow value was measured in the same manner as in Example 1. In addition, the time from the preparation of soil cement (L37) until the table flow value became less than 150 mm or less than 200 mm was determined.
The above results are shown in Table 4.

Example 22
15.0 kg of an aqueous sodium polyacrylate solution (W1), 3.75 kg of sodium carbonate powder, and 3.75 kg of sodium bicarbonate powder were mixed to obtain a fluidizing agent for soil cement (S38). The composition of this fluidizing agent for soil cement (S38) is that when the content of sodium polyacrylate (A1) is 100 parts, the content of sodium carbonate is 58 parts and the content of sodium bicarbonate is 58 parts. 58 copies (see Table 4).
Next, 22.5 kg (solid content 13.95 kg) of this fluidizing agent for soil cement (S38), 160 kg of blast furnace cement B type, and 480 kg of water were mixed to obtain a cement-based suspension (C38). After that, the content of sodium polyacrylate (A1) was 6.45 kg, the content of sodium carbonate was 3.75 kg, and the content of sodium bicarbonate was 3.75 kg in 1 m ³ of the above-mentioned Kozumi cohesive soil (S). Sodium cement (L38) was obtained by adding a cement-based suspension (C38) and mixing them.
For the obtained soil cement (L38), the table flow value was measured in the same manner as in Example 1. In addition, the time from the preparation of soil cement (L38) until the table flow value became less than 150 mm or less than 200 mm was determined.
The above results are shown in Table 4.

Example 23
3.5 kg of an aqueous sodium polyacrylate solution (W1), 10.0 kg of sodium carbonate powder, and 10.0 kg of sodium bicarbonate powder were mixed to obtain a fluidizing agent for soil cement (S39). The composition of this fluidizing agent for soil cement (S39) is that the content of sodium carbonate is 664 parts and the content of sodium bicarbonate is 664 parts when the content of sodium polyacrylate (A1) is 100 parts. 664 copies (see Table 4).
Next, 23.5 kg (solid content 21.51 kg) of this fluidizing agent for soil cement (S39), 160 kg of blast furnace cement B type, and 480 kg of water were mixed to obtain a cement-based suspension (C39). After that, the content of sodium polyacrylate (A1) was 1.51 kg, the content of sodium carbonate was 10.0 kg, and the content of sodium bicarbonate was 10.0 kg in 1 m ³ of the above-mentioned Kozumi cohesive soil (S). Sodium cement (L39) was obtained by adding a cement-based suspension (C39) and mixing them.
For the obtained soil cement (L39), the table flow value was measured in the same manner as in Example 1. In addition, the time from the preparation of soil cement (L39) until the table flow value became less than 150 mm or less than 200 mm was determined.
The above results are shown in Table 4.

Example 24
4.0 kg of an aqueous sodium polyacrylate solution (W1), 12.5 kg of sodium carbonate powder, and 12.5 kg of sodium bicarbonate powder were mixed to obtain a fluidizing agent for soil cement (S40). The composition of this fluidizing agent for soil cement (S40) is that when the content of sodium polyacrylate (A1) is 100 parts, the content of sodium carbonate is 581 parts and the content of sodium bicarbonate is 581 parts. 581 copies (see Table 4).
Next, 29.0 kg (solid content 26.72 kg) of this fluidizing agent for soil cement (S40), 160 kg of blast furnace cement B type, and 480 kg of water were mixed to obtain a cement-based suspension (C40). After that, the content of sodium polyacrylate (A1) was 1.72 kg, the content of sodium carbonate was 12.5 kg, and the content of sodium bicarbonate was 12.5 kg in 1 m ³ of the above-mentioned Kozumi cohesive soil (S). Sodium cement (L40) was obtained by adding a cement-based suspension (C40) and mixing them.
For the obtained soil cement (L40), the table flow value was measured in the same manner as in Example 1. In addition, the time from the preparation of soil cement (L40) until the table flow value became less than 150 mm or less than 200 mm was determined.
The above results are shown in Table 4.

Example 25
5.0 kg of an aqueous sodium polyacrylate solution (W2), 7.5 kg of sodium carbonate powder, and 7.5 kg of sodium bicarbonate powder were mixed to obtain a fluidizing agent for soil cement (S41). The composition of this fluidizing agent for soil cement (S41) is that when the content of sodium polyacrylate (A2) is 100 parts, the content of sodium carbonate is 356 parts and the content of sodium bicarbonate is 356 parts. There are 356 copies (see Table 4).
Next, 20.0 kg (solid content 17.11 kg) of this fluidizing agent for soil cement (S41), 160 kg of blast furnace cement B type, and 480 kg of water were mixed to obtain a cement-based suspension (C41). After that, the content of sodium polyacrylate (A2) was 2.11 kg, the content of sodium carbonate was 7.5 kg, and the content of sodium bicarbonate was 7.5 kg in 1 m ³ of the above-mentioned Kozumi cohesive soil (S). Sodium cement (L41) was obtained by adding a cement-based suspension (C41) and mixing them.
For the obtained soil cement (L41), the table flow value was measured in the same manner as in Example 1. Further, the time from the preparation of the soil cement (L41) until the table flow value became less than 150 mm or less than 200 mm was determined.
The above results are shown in Table 4.

Comparative Example 7
5.0 kg of an aqueous solution of sodium polyacrylate (W1) and 7.5 kg of sodium carbonate powder were mixed to obtain a fluidizing agent for soil cement (S42). The composition of this fluidizing agent for soil cement (S42) is that the content of sodium carbonate is 349 parts when the content of sodium polyacrylate (A1) is 100 parts (see Table 4).
Next, 12.5 kg (solid content 9.65 kg) of this fluidizing agent for soil cement (S42), 160 kg of blast furnace cement B type, and 480 kg of water were mixed to obtain a cement-based suspension (C42). Then, the cement-based suspension (C42) so that the content of sodium polyacrylate (A1) is 2.15 kg and the content of sodium carbonate is 7.5 kg in 1 m ³ of the above-mentioned Kozumi cohesive soil (S). ) Was added and these were mixed to obtain soil cement (L42).
For the obtained soil cement (L42), the table flow value was measured in the same manner as in Example 1. In addition, the time from the preparation of soil cement (L42) until the table flow value became less than 150 mm or less than 200 mm was determined.
The above results are shown in Table 4.

Comparative Example 8
3.0 kg of an aqueous sodium polyacrylate solution (W1), 10.0 kg of sodium carbonate powder, and 10.0 kg of sodium bicarbonate powder were mixed to obtain a fluidizing agent for soil cement (S43). The composition of this fluidizing agent for soil cement (S43) is that the content of sodium carbonate is 775 parts and the content of sodium bicarbonate is 775 parts when the content of sodium polyacrylate (A1) is 100 parts. 775 copies (see Table 4).
Next, 23.0 kg (solid content 21.29 kg) of this fluidizing agent for soil cement (S43), 160 kg of blast furnace cement B type, and 480 kg of water were mixed to obtain a cement-based suspension (C43). After that, the content of sodium polyacrylate (A1) was 1.29 kg, the content of sodium carbonate was 10.0 kg, and the content of sodium bicarbonate was 10.0 kg in 1 m ³ of the above-mentioned Kozumi cohesive soil (S). Sodium cement (L43) was obtained by adding a cement-based suspension (C43) and mixing them.
For the obtained soil cement (L43), the table flow value was measured in the same manner as in Example 1. In addition, the time from the preparation of soil cement (L43) until the table flow value became less than 150 mm or less than 200 mm was determined.
The above results are shown in Table 4.

Comparative Example 9
5.0 kg of an aqueous sodium polyacrylate solution (W1), 1.0 kg of sodium carbonate powder, and 1.0 kg of sodium bicarbonate powder were mixed to obtain a fluidizing agent for soil cement (S44). The composition of this fluidizing agent for soil cement (S44) is that when the content of sodium polyacrylate (A1) is 100 parts, the content of sodium carbonate is 47 parts and the content of sodium bicarbonate is 47 parts. 47 copies (see Table 4).
Next, 7.0 kg (solid content 4.15 kg) of this fluidizing agent for soil cement (S44), 160 kg of blast furnace cement B type, and 480 kg of water were mixed to obtain a cement-based suspension (C44). After that, the content of sodium polyacrylate (A1) was 2.15 kg, the content of sodium carbonate was 1.0 kg, and the content of sodium bicarbonate was 1.0 kg in 1 m ³ of the above-mentioned Kozumi cohesive soil (S). Sodium cement (L44) was obtained by adding a cement-based suspension (C44) and mixing them.
For the obtained soil cement (L44), the table flow value was measured in the same manner as in Example 1. In addition, the time from the preparation of soil cement (L44) until the table flow value became less than 150 mm or less than 200 mm was determined.
The above results are shown in Table 4.

Comparative Example 10
5.0 kg of an aqueous solution of sodium polyacrylate (W1) and 7.5 kg of sodium bicarbonate powder were mixed to obtain a fluidizing agent for soil cement (S45). The composition of the fluidizing agent for soil cement (S45) is that the content of sodium bicarbonate is 349 parts when the content of sodium polyacrylate (A1) is 100 parts (see Table 4).
Next, 12.5 kg (solid content 9.65 kg) of this fluidizing agent for soil cement (S45), 160 kg of blast furnace cement B type, and 480 kg of water were mixed to obtain a cement-based suspension (C45). Then, a cement-based suspension (sodium polyacrylate (A1) content of 2.15 kg and sodium bicarbonate content of 7.5 kg in 1 m ³ of the above-mentioned Kozumi cohesive soil (S)) ( C45) was added and these were mixed to obtain soil cement (L45).
For the obtained soil cement (L45), the table flow value was measured in the same manner as in Example 1. In addition, the time from the preparation of soil cement (L45) until the table flow value became less than 150 mm or less than 200 mm was determined.
The above results are shown in Table 4.

Comparative Example 11
5.0 kg of an aqueous solution of sodium polyacrylate (W1) and 20.0 kg of sodium carbonate powder were mixed to obtain a fluidizing agent for soil cement (S46). The composition of this fluidizing agent for soil cement (S46) is that the content of sodium carbonate is 930 parts when the content of sodium polyacrylate (A1) is 100 parts (see Table 4).
Next, 25.0 kg (solid content 22.15 kg) of this fluidizing agent for soil cement (S46), 160 kg of blast furnace cement B type, and 480 kg of water were mixed to obtain a cement-based suspension (C46). Then, the cement-based suspension (C46) so that the content of sodium polyacrylate (A1) is 2.15 kg and the content of sodium carbonate is 20.0 kg in 1 m ³ of the above-mentioned Kozumi cohesive soil (S). ) Was added and these were mixed to obtain soil cement (L46).
For the obtained soil cement (L46), the table flow value was measured in the same manner as in Example 1. In addition, the time from the preparation of soil cement (L46) until the table flow value became less than 150 mm or less than 200 mm was determined.
The above results are shown in Table 4.

From Tables 1 to 4, the soil cement obtained by using the fluidizer for soil cement and the cement-based suspension in Examples 1 to 25 has a table flow value of less than 150 mm from the time of preparation. It is clear that the time until (flow retention time) can be set to 6 hours or more, and the fluidity retention time can be arbitrarily controlled in the range of 6 to 36 hours.

The fluidizing agent composition for soil cement, the cement-based suspension and the soil cement of the present invention use the soil of the original ground (underground) as a ground improvement method, an underground continuous wall method, a foundation pile method, and backfilling. Suitable for construction methods and the like.

Claims (6)

(A) Water-soluble polymer,
(B) Alkali carbonate metal salt,
as well as,
(C) A fluidizing agent composition for soil cement containing an alkali metal bicarbonate composition.
The water-soluble polymer (A) is a structural unit derived from a monomer having an ethylenically unsaturated bond, contains a structural unit having a COO bond, and has a weight average molecular weight of 50,000 or less. ,
The contents of the alkali metal carbonate (B) and the alkali metal bicarbonate (C) are 10 to 1300 parts by mass and 10 to 10 to 1 parts by mass with respect to 100 parts by mass of the water-soluble polymer (A), respectively. 1300 parts by mass,
The total content of the alkali metal carbonate (B) and the alkali metal bicarbonate (C) is 100 to 1500 parts by mass with respect to 100 parts by mass of the water-soluble polymer (A) .
A fluidizing agent composition for soil cement, wherein the mass ratio of the alkali metal carbonate (B) and the alkali metal bicarbonate (C) is 85:15 to 15:85. The fluidizing agent composition for soil cement according to claim 1, wherein the water-soluble polymer (A) is a polymer containing a structural unit derived from acrylic acid or a salt thereof. The fluidizing agent composition for soil cement according to claim 1 or 2, wherein the alkali metal carbonate (B) is sodium carbonate and the alkali metal bicarbonate (C) is sodium bicarbonate. The fluidizing agent composition for soil cement according to any one of claims 1 to 3, which is used in a ground improvement method, an underground continuous wall method, a foundation pile method or a backfill method. A cement-based suspension comprising the fluidizing agent composition for soil cement according to any one of claims 1 to 4, cement, and water. A soil cement comprising the cement-based suspension according to claim 5 and soil.