JP5735386B2 - Cement composition and method for producing injection material using the same - Google Patents

Description

  The present invention relates to a backfill material for a cavity or void in a natural ground, a filler for a shield segment, a quick setting injection material in a double pipe single phase or double phase injection method, and a double pipe double packer. The present invention relates to a cement composition used for a use in which the viscosity of cement milk, cement mortar, or concrete needs to be rapidly increased by a sealing material or a primary injection material in a construction method, and an injection material using the same.

In recent years, tunnel repair work, where the number of construction works has been increasing, includes a backfill injection method that fills the cavity behind the lining concrete with an injection material.
The backfill injection method is to fill the cavity with an injection material to stabilize the tunnel, and the injection material used here is called a backfill material.

  Conventionally, cement-bentonite has been usually used as the injecting material, but the fluidity is too high, the injecting material unnecessarily flows far away, and if there is spring water, the injecting material flows out or dilutes. As a result, there were problems such as deterioration of physical properties.

As a method to solve the problems of the injection material, a cement composition containing an alkali thickening polymer in combination with the main material of cement, bentonite, hardening accelerator, and coal ash is used. The thing which improved the non-separation property is proposed (patent documents 1-patent documents 3).
However, when these cement compositions are used to obtain high strength, the fluidity is lost and the construction is difficult.

On the other hand, it is known that fluidity is improved by using lignin sulfonate and alkyl allyl sulfonate together (Patent Document 4).
However, in Patent Document 4, lignin sulfonic acid salt, alkylallyl sulfonic acid salt, melamine sulfone sun salt, and polycarboxylic acid salt, which are generally known as dispersants, are not only used alone but also lignin sulfonic acid. The lignin sulfonate and alkyl allyl sulfonate combination system provides fluidity of a mixture of cement and water, as well as a combination of alkali thickening polymer emulsion and water, rather than combinations other than salts and alkyl allyl sulfonates. It is not described that the thickening effect after mixing with the mixture obtained by mixing is large.

JP 2002-029803 A JP 2002-179447 A JP 2004-143037 A JP 2008-247777 A

In the present invention, the fluidity of liquid A, which is a mixture of cement and water, is good, and after mixing with liquid B, which is a mixture of an alkali-thickened polymer emulsion and water, the viscosity increases. Higher strength is obtained.
As a result of various efforts to solve the above problems, the present inventor, by combining specific materials, rapidly increases in viscosity, and can be applied without separation of materials even in the presence of water. As a result, it was found that an injection material having an excellent strength development property and an excellent ground reinforcement effect was obtained, and the present invention was completed.

The present invention employs the following means in order to solve the above problems.
(1) A cement composition comprising a cement, a dispersant comprising a lignin sulfonate and an alkyl allyl sulfonate, and an alkali thickening polymer emulsion.
(2) The cement composition according to (1), wherein a blending ratio of lignin sulfonate / alkyl allyl sulfonate of the dispersant is 30 to 60 parts by mass / 40 to 70 parts by mass. .
(3) The cement composition according to (1) or (2), wherein the dispersant is 0.1 to 2 parts by mass in terms of solid content with respect to 100 parts by mass of cement.
(4) The alkali thickening polymer emulsion is 0.01 to 1 part by mass in terms of solid content with respect to 100 parts by mass of cement, and is any one of the above (1) to (3) It is a cement composition.
(5) The cement composition according to any one of (1) to (4), further comprising a curing accelerator.
(6) The cement composition according to any one of (1) to (5), wherein the curing accelerator is 1 to 30 parts by mass with respect to 100 parts by mass of cement.
(7) An injection material comprising the cement composition according to any one of (1) to (6) and water.
(8) A mixture of cement, a dispersant composed of lignin sulfonate and alkyl allyl sulfonate, and water is used as liquid A, and a mixture of alkali thickening polymer emulsion and water is used as liquid B. A method for producing an injection material, wherein the liquid A and the liquid B are mixed immediately before.
(9) Mixture containing cement, lignin sulfonate and alkyl allyl sulfonate, and water is used as liquid A, and a mixture of alkali thickening polymer emulsion and water is used as liquid B. A mixture of an accelerator and water is used as liquid C, and the liquid A, liquid B, and liquid C are mixed immediately before use.

  According to the present invention, it is possible to perform construction without separating the material even in the presence of water, the viscosity is rapidly increased, excellent strength development after curing, and an excellent ground reinforcement effect.

Hereinafter, the present invention will be described in detail.
In addition, unless otherwise indicated, the part and% in this invention are shown by a mass reference | standard.

  The cement used in the present invention is not particularly limited, and ordinary cement can be used. Specifically, it is possible to use various portland cements such as normal, early strength, ultra-early strength, and moderate heat, and various mixed cements in which blast furnace slag, silica, fly ash, etc. are mixed with these portland cements. . Moreover, it is also possible to use fine particle cements or ultrafine particle cements obtained by further reducing these cements.

In the present invention, liquid A, which is a mixture of cement and water, is produced.
In order to obtain higher strength, the lower the amount of water with respect to the cement, the higher the strength can be obtained. However, when the amount of water decreases, the fluidity is lost, and the kneading property and the pumpability are deteriorated.
Therefore, fluidity after mixing cement and water is essential. Increasing the amount of water improves fluidity, but simply increasing the amount of water does not provide high strength, but the fluidity after mixing with B liquid, which is a mixture of an alkali-thickened polymer emulsion and water, It is not lost and is not water resistant.

In the present invention, in order to improve the fluidity of the liquid A, lignin sulfonate and alkyl allyl sulfonate are used in combination as a dispersant.
The mixing method of lignin sulfonate and alkyl allyl sulfonate is not particularly limited, and may be simultaneous or separate.

Generally, as a dispersing agent used in the cement field, lignin sulfonate, alkylallyl sulfonate, melamine sulfonate, polycarboxylic acid and the like are known.
In the present invention, these dispersants are used alone or in combination other than lignin sulfonate and alkyl allyl sulfonate, but there is no effect, but only when lignin sulfonate and alkyl allyl sulfonate are used in combination, liquid A After obtaining the above fluidity, the fluidity after mixing with the liquid B can be eliminated. Examples of the salt include sodium and potassium.

  The lignin sulfonate used in the present invention can be a general lignin sulfonate water reducing agent, and is not particularly limited, and can be used regardless of powder or liquid. For example, the product name “Sunflow” manufactured by Nippon Paper Chemical Co., Ltd., and the product name “Pozoris” manufactured by BASF Pozzolith are available.

  In addition, as the alkyl allyl sulfonate, a general alkyl allyl sulfonate water reducing agent can be used, and examples thereof include xylene sulfonate, alkyl benzene sulfonate, and naphthalene sulfonate. It can be used regardless of powder or liquid. For example, there is a trade name “Mighty” manufactured by Kao Corporation, a trade name “FT” manufactured by Denki Kagaku Kogyo Co., Ltd. and the like.

The ratio of lignin sulfonate to alkyl allyl sulfonate is preferably 30 to 60 parts of lignin sulfonate and 40 to 70 parts of alkyl allyl sulfonate. The fluidity after mixing can be eliminated.
When the amount of lignin sulfonate exceeds this range, it becomes difficult to obtain the fluidity of the liquid A. When the amount of lignin sulfonate is less than this range, the fluidity after mixing with the liquid B is not lost.
As such a mixture, there is a trade name “FT-80” manufactured by Denki Kagaku Kogyo Co., Ltd., which can be used.

  The amount of the dispersant composed of lignin sulfonate and alkyl allyl sulfonate is preferably 0.1 to 2 parts in terms of solid content with respect to 100 parts of cement. If it is less than this range, the effect of addition is small, and if it exceeds this range, the fluidity after mixing with the liquid B is unlikely to be small.

  The amount of water relative to cement is preferably 30 to 80 parts with respect to 100 parts of cement. If the amount of water is small, the fluidity of the liquid A tends to be unfavorable. If the amount of water is large, the strength of the concrete tends to be weak, which tends to be undesirable.

  The alkali thickening polymer emulsion (hereinafter referred to as the present emulsion) used in the present invention is a polymer emulsion obtained by copolymerization of an unsaturated carboxylic acid and an ethylenically unsaturated compound.

  Here, the alkali thickening type refers to the property that the polymer is neutralized when it comes into contact with, for example, an alkali of cement, an alkali having a pH of 9 to 13, and becomes soluble in water to increase the viscosity of the emulsion.

  Examples of the emulsion include various unsaturated carboxylic acids, ethylenically unsaturated compounds, and copolymers of unsaturated carboxylic acids and ethylenically unsaturated compounds, etc., but in terms of showing a more excellent thickening effect, Polymer emulsions obtained by copolymerization of unsaturated carboxylic acids and ethylenically unsaturated compounds are preferred. Examples of the polymerization method of the unsaturated carboxylic acid and the ethylenically unsaturated compound include a method of copolymerization by a method such as emulsion polymerization, suspension polymerization, solution polymerization, or bulk polymerization.

  Examples of unsaturated carboxylic acids include unsaturated carboxylic acids such as acrylic acid, methacrylic acid, itaconic acid, maleic acid, fumaric acid, citraconic acid, aconitic acid, and crotonic acid, and unsaturated carboxylic acids such as maleic anhydride and citraconic anhydride. Acid anhydrides, and unsaturated carboxylic acid esters such as monomethyl itaconate, monobutyl itaconate, and monoethyl maleate. Among these, unsaturated carboxylic acids are preferred in terms of higher viscosity, and acrylic acid And / or methacrylic acid is more preferred.

The ethylenically unsaturated compound is not particularly limited, but is preferably an acrylate monomer and / or a methacrylic acid ester monomer in terms of more excellent viscosity.
Examples of acrylic esters include methyl acrylate, ethyl acrylate, butyl acrylate, hexyl acrylate, cyclohexyl acrylate, octyl acrylate, hydroxyethyl acrylate, 2-ethylhexyl acrylate, and glycidyl acrylate. Methacrylic acid esters include methyl methacrylate, Examples include ethyl methacrylate, butyl methacrylate, hydroxyethyl methacrylate, and glycidyl methacrylate.

  The solid content concentration of the emulsion for preparing the emulsion is not particularly limited, and is usually preferably about 20 to 60%, more preferably 30 to 50% in terms of solid content concentration. If the concentration is low, the transportation cost is increased, and if the concentration is high, the viscosity becomes high and the handling property is deteriorated.

  The amount of the emulsion used is preferably 0.01 to 1 part in terms of solid content with respect to 100 parts of cement. If it is less than this range, the thickening effect may be small, and if it is more than this range, the initial strength development may be deteriorated.

  The injection material of the present invention includes cement A, a dispersant composed of lignin sulfonate and alkyl allyl sulfonate, and a liquid A that is a mixture of water, and a liquid B that is a mixture of the emulsion and water. Obtained by mixing.

  Also, in the present invention, if the curing of the cement composition is delayed, material separation such as bleeding (floating water) occurs, and voids may be generated after curing, resulting in structural defects. It is also effective to do.

  The hardening accelerator promotes hardening of the cement composition, reduces material separation, suppresses the formation of voids and contributes to strength development, and particularly preferably contains an aluminate and a sulfate. .

As the aluminate, calcium aluminate is preferable, and it is obtained by mixing a raw material containing calcia and a raw material containing alumina, and obtained by heat treatment such as firing in a kiln or melting in an electric furnace. Al ₂ O ₃ is a main component and has a hydration activity. The mineral form may be either crystalline or amorphous.
Among these, amorphous calcium aluminate is preferable in terms of reaction activity, and amorphous calcium aluminate obtained by quenching the heat-treated product corresponding to the 12CaO · 7Al ₂ O ₃ composition is more preferable.
The particle size of the aluminate is preferably 3,000 cm ² / g or more in terms of the specific surface area of the brain (hereinafter referred to as the brain value). If it is less than 3,000 cm ² / g, the initial strength development may decrease.

Moreover, as a sulfate, calcium sulfate and / or aluminum sulfate are preferable.
Examples of calcium sulfate include anhydrous gypsum, hemihydrate gypsum, and dihydrate gypsum. Among these, anhydrous gypsum is preferable in terms of strength development.
The particle size of the sulfate is preferably 3,000 cm ² / g or more in terms of the brain value. If it is less than 3,000 cm ² / g, strength development may be reduced.

  The blending ratio of the aluminate and the sulfate is preferably 20 to 500 parts with respect to 100 parts of the aluminate. If it is less than this range, the strength development may be reduced, and if it is more than this range, the flow value will increase, the inseparability in water will deteriorate, and the long-term strength development may be reduced.

  As for the usage-amount of a hardening accelerator, 1-30 parts are preferable with respect to 100 parts of cement. If the amount is less than this range, the flow value increases, the inseparability in water deteriorates, and the strength development property may be reduced.

  Moreover, when preparing C liquid which is a mixture which mixed the hardening accelerator and water, since a hardening accelerator may be hardened | cured when mixed with water, it is preferable to use a hardening retarder together.

  Curing retarders include oxycarboxylic acids such as citric acid, tartaric acid, gluconic acid and malic acid, or sodium salts or potassium salts thereof, or salts thereof, boric acid, tripolyphosphate, and pyrroline. An acid salt etc. are mentioned, It is possible to use together 1 type, or 2 or more types of these hardening retarders. Among these, oxycarboxylate is preferable and sodium citrate is more preferable in terms of a large delay effect.

  The amount of the curing retarder used is preferably 0.01 to 1 part with respect to 100 parts of cement. If it is less than this range, the delay effect may be small, and if it is more than this range, the strength development may be small.

The mixing method of the cement is not particularly defined, but the dispersing agent, the present emulsion, and the hardening accelerator are mixed with water in advance to form a solution or suspension, so that the mixing property becomes good and the viscosity increases. From the viewpoint of
For example, a mixture obtained by mixing cement, a dispersant and water is designated as liquid A, a mixture obtained by mixing the emulsion and water is designated as liquid B, and the liquid A and B are mixed immediately before use. When strength is required, a mixture obtained by mixing cement, a dispersant and water is used as liquid A, and a mixture obtained by mixing the emulsion and water is used as liquid B, and a curing accelerator and water are mixed. A method in which the mixture is liquid C and the viscosity is rapidly increased by mixing the liquid A, liquid B, and liquid C immediately before use is preferable.

In the present invention, when liquid A and liquid B, or liquid A, liquid B, and liquid C are mixed, fluidity decreases in a few seconds, so liquid A, liquid B, or liquid A, liquid B, and liquid C are separated separately. Work while pumping and mixing at the tip.
As a method of merging and mixing, there is a method of mixing by using a mixing tube such as a Y-shaped tube and then setting and mixing a spiral mixer.

  The fluidity after A liquid, B liquid, A liquid, B liquid, and C liquid are separately pumped and mixed can be confirmed by the flow value. For example, after filling a flow cone having an inner diameter of 80 mm and a height of 80 mm with an injection material, the spread after the flow cone is pulled out is measured. In order to perform construction without separating materials even in the presence of water, the flow value is preferably 150 mm or less. More preferably, it is 120 mm or less.

  Hereinafter, further description will be given based on experimental examples.

Experimental example 1
Cement, various dispersants shown in Table 1, and water were kneaded with a mixer to prepare solution A.
Next, the emulsion shown in Table 1 and water were mixed to prepare solution B.
Liquid A and liquid B were put into a mixer and mixed for 5 seconds so that the emulsion was 0.05 parts in terms of solid content with respect to 100 parts of cement to prepare an injection material.
The flow value, water inseparability, and compressive strength of the prepared injection material were measured. The results are also shown in Table 1.

<Materials used>
Cement: ordinary Portland cement, commercially available dispersant a: sodium lignin sulfonate, commercially available dispersant b: sodium naphthalene sulfonate, commercially available dispersant c: sodium melamine sulfonate, commercially available dispersant d: sodium polycarboxylate, Commercially available emulsion: ethyl acrylate / methacrylic acid copolymer emulsion with solid content of 30%, ethyl acrylate: methacrylic acid = 45:55

<Measurement method>
Flow value: The mixture was put into a cylinder with an inner diameter of 80 mm and a height of 80 mm, and the spread after the cylinder was pulled out was measured after 2 minutes.
Inseparability in water: A cylinder having an inner diameter of 80 mm and a height of 80 mm containing the prepared injection material was put into a 45 liter water tank, and the turbidity of water after the cylinder was pulled out was observed.
Compressive strength: 28-day strength measurement according to JIS R 5201

Experimental example 2
Experimental Example 1 except that a mixture A was prepared by kneading 1 part of a mixture of dispersant a and dispersant b and 43 parts of water with a mixer with respect to 100 parts of cement and 100 parts of cement. The same was done. The results are also shown in Table 2.

Experimental example 3
Except that the liquid A was prepared by kneading an equivalent mixture of dispersant a and dispersant b shown in Table 3 and water with a mixer with respect to 100 parts of cement and 100 parts of cement. went. The results are also shown in Table 3.

Experimental Example 4
Mix 1 part mixture of dispersant a and dispersant b with 43 parts of water and 100 parts of cement with a mixer to prepare liquid A, mix 2 parts of emulsion and 98 parts of water. A liquid B was prepared, and the same procedure as in Experimental Example 1 was performed except that the liquid A and the liquid B were mixed so that the emulsion was in solids equivalent to 100 parts of cement with the amount shown in Table 4. . The results are also shown in Table 4.

Experimental Example 5
Mix 1 part of an equivalent mixture of Dispersant a and Dispersant b and 43 parts of water to 100 parts of cement with a mixer and mix A liquid, then 2 parts of emulsion and 98 parts of water. Liquid B was mixed and liquid accelerator C and water were mixed to prepare liquid C.
With respect to 100 parts of cement, the emulsion is 0.05 parts in terms of solid content, and the liquid A, liquid B, and liquid C are continuously added to the mixer so that the amount of the hardening accelerator is shown in Table 5, The procedure was the same as in Experimental Example 1 except that mixing was performed. The results are also shown in Table 5.

<Materials used>
Hardening accelerator: aluminate (calcium aluminate, heat-treated product corresponding to 12CaO · 7Al ₂ O ₃ composition, amorphous, brane value 6,000cm ² / g) and sulfate (anhydrite) , Blaine value 5,400 cm ² / g) Mixture consisting of 100 parts

Claims (9)

  A cement composition comprising a cement, a dispersant composed of lignin sulfonate and an alkyl allyl sulfonate, and an alkali thickening polymer emulsion.   2. The cement composition according to claim 1, wherein a mixing ratio of lignin sulfonate / alkyl allyl sulfonate of the dispersant is 30 to 60 parts by mass / 40 to 70 parts by mass.   The cement composition according to claim 1 or 2, wherein the dispersant is 0.1 to 2 parts by mass in terms of solid content with respect to 100 parts by mass of cement.   The said alkali-thickening type polymer emulsion is 0.01-1 mass part in conversion of solid content with respect to 100 mass parts of cement, The any one of Claims 1-3 characterized by the above-mentioned. Cement composition.   Furthermore, a hardening accelerator is contained, The cement composition of any one of Claims 1-4 characterized by the above-mentioned.   The said hardening accelerator is 1-30 mass parts with respect to 100 mass parts of cement, The cement composition of any one of Claims 1-5 characterized by the above-mentioned.   An injection material comprising the cement composition according to any one of claims 1 to 6 and water.   A mixture of a cement, a dispersant composed of lignin sulfonate and an alkyl allyl sulfonate, and water is designated as liquid A, and a mixture obtained by mixing an alkali thickening polymer emulsion and water is designated as liquid B. A method for producing an injection material, wherein the liquid and the liquid B are mixed.   Cement, a dispersant composed of lignin sulfonate and alkyl allyl sulfonate, and a mixture of water and liquid A, a mixture of an alkali thickening polymer emulsion and water as liquid B, a curing accelerator, A method for producing an injection material, wherein a mixture obtained by mixing water is used as a liquid C, and the liquid A, liquid B, and liquid C are mixed immediately before use.