Grouting composition for rock consolidation

Abstract

To provide an injection chemical composition for ground solidification, which suppresses separation of an aqueous sodium silicate solution and an organic component in a polyol component and which secures stable reactivity and a range of ground improvement under an environment where water leakage and spring water abound.SOLUTION: Provided is an injection chemical composition for ground solidification comprising a polyol component (A) and a polyisocyanate component (B), where the polyol component (A) comprises an aqueous sodium silicate solution (A-1), a polyol (A-2) containing a polyol (p-1) having at least one selected from the group consisting of a bromine atom, a phosphorus atom, and chlorine atom in the molecule, and a tertiary amine catalyst (A-3), and the polyisocyanate component (B) is a mixture (B-1) of diphenylmethane diisocyanate and polyphenyl polymethylene polyisocyanate or a reaction product (B-2) of a polyol having active hydrogens and (B-1).SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a grouting composition for rock consolidation that can be used even in environments with a lot of spring water or leaks. [Background technology]

[0002] One method for strengthening unstable rock mass or unstable ground is the rock bolting method, which stabilizes the surrounding ground during tunnel excavation. This method aims to protect the tunnel structure by fixing and anchoring bolts with a chemical solution. Traditionally, inorganic materials such as mortar, which have high strength, have been used as the injection solution for consolidating rock mass. However, these inorganic materials have poor work efficiency due to the long time required for them to develop strength, and also have the problem of the material flowing into the water in the event of water leakage or spring water.

[0003] Recently, tunnel excavation has been carried out in areas prone to water leaks and springs. Contamination of springs by chemicals and water leaks that cannot be stopped even by injecting chemicals are hindering the efficiency and safety of excavation work, and improvements are being called for.

[0004] To solve these problems, an inorganic-organic composite soil stabilization liquid, that is, an injection liquid that combines an aqueous silicate solution called water glass with a polyisocyanate composition, is used.

[0005] For example, Patent Document 1 reports that by using a silicate aqueous solution component containing an amine catalyst and an organic polyol and diphenylmethane diisocyanate modified with a polyether polyol as an injection solution for rock consolidation, it is possible to improve the long hardening time, strength development time, and groundwater and spring water contamination that are disadvantages of inorganic systems. However, because the silicate aqueous solution component containing the amine catalyst and short-chain diol is very susceptible to separation, it is necessary to stir it in the tank of the injection device and then immediately perform the injection work. If an interval occurs during injection, there is a concern that an abnormal reaction will occur due to the separated amine catalyst and organic polyol, which will result in the injection port being blocked, reducing the area of ​​ground improvement. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] JP2006-131785Publication Summary of the Invention [Problem to be solved by the invention]

[0007] The present invention has been made in view of the above-mentioned background art, and aims to provide a grouting composition for rock consolidation that suppresses separation of the sodium silicate aqueous solution and the organic component in the polyol component, and ensures stable reactivity and a range of ground improvement even in environments with frequent water leakage and spring water. [Means for solving the problem]

[0008] As a result of extensive research, the inventors have discovered that the above-mentioned problems can be solved by a liquid injection composition for rock consolidation agents, which comprises a specific polyol component (A) containing an aqueous sodium silicate solution as the main component, and a specific polyisocyanate component (B), and have thus completed the present invention.

[0009] That is, the present invention includes the following embodiments [1] to [9].

[0010] [1] A grout composition for rock consolidation comprising a polyol component (A) and a polyisocyanate component (B), wherein the polyol component (A) comprises an aqueous sodium silicate solution (A-1), a polyol (A-2) containing a polyol (p-1) having at least one atom selected from the group consisting of bromine atoms, phosphorus atoms, and chlorine atoms in its molecule, and a tertiary amine catalyst (A-3), and the polyisocyanate component (B) is a mixture (B-1) of diphenylmethane diisocyanate and polyphenylpolymethylene polyisocyanate, or a reaction product of a polyol (B-2) having active hydrogen and (B-1).

[0011] [2] The grouting composition for rock consolidation according to the above [1], characterized in that the mass ratio of diphenylmethane diisocyanate (B-1) to polyphenylpolymethylene polyisocyanate in the polyisocyanate component (B) is 35 / 65 to 75 / 25, and the mass ratio of 4,4'-diphenylmethane diisocyanate in the diphenylmethane diisocyanate to the total of 2,2'-diphenylmethane diisocyanate and 2,4'-diphenylmethane diisocyanate is 85 / 15 to 55 / 45.

[0012] [3] The grouting composition for rock consolidation according to the above [1] or [2], characterized in that (p-1) contained in (A-2) of the polyol component (A) contains at least one polyol having a specific gravity of 1.30 or more at 25°C.

[0013] [4] A grouting composition for rock consolidation according to any one of [1] to [3] above, characterized in that (A-2) in the polyol component (A) is a mixed polyol of (p-1) and a polyol other than (p-1), and the specific gravity of the mixed polyol at 25°C is 1.20 or more.

[0014] [5] A grouting composition for rock consolidation according to any one of [1] to [4] above, characterized in that the specific gravity of the mixture of (A-2) and (A-3) in the polyol component (A) at 25°C is 1.15 or more.

[0015] [6] The grout composition for rock consolidation according to any one of [1] to [5] above, wherein the polyol component (A) contains a dispersant.

[0016] [7] The grout composition for rock consolidation according to any one of [1] to [6] above, wherein the polyisocyanate component (B) contains a viscosity reducer.

[0017] [8] The grouting composition for rock consolidation according to any one of [1] to [7] above, wherein the polyisocyanate component (B) contains a foam stabilizer.

[0018] [9] A solidified body obtained from the grout composition for rock consolidation according to any one of [1] to [8] above. [Effects of the Invention]

[0019] According to the grouting composition for rock consolidation of the present invention, by suppressing separation of the amine catalyst and organic polyol from the sodium silicate aqueous solution component, it is possible to obtain stable reactivity and a range of ground improvement even in environments with frequent water leakage and spring water due to sufficient injection stability. DETAILED DESCRIPTION OF THE INVENTION

[0020] The grouting composition for rock consolidation in the present invention comprises a polyol component (A) (hereinafter also referred to simply as "component (A)") and a polyisocyanate component (B) (hereinafter also referred to simply as "component (B)").

[0021] First, the polyol component (A) will be described.

[0022] The polyol component (A) comprises an aqueous sodium silicate solution (A-1) (hereinafter also referred to as (A-1)), a polyol (A-2) (hereinafter also referred to as (A-2)), which comprises a polyol (p-1) (hereinafter also referred to as (p-1)) having at least one atom selected from the group consisting of bromine atoms, phosphorus atoms, and chlorine atoms in its molecule, and a tertiary amine catalyst (A-3) (hereinafter also referred to as (A-3)).

[0023] Commercially available aqueous sodium silicate solutions can be used as (A-1) in the present invention. Sodium silicate is generally represented by the formula Na2O·xSiO2·nH2O. Here, x represents the molar ratio of SiO2 (silicon dioxide) to Na2O (sodium oxide), and in the present invention, it is preferably 2.0 to 3.0, more preferably 2.0 to 2.5, and most preferably 2.0 to 2.4. If x is less than 2.0, foaming properties may not be achieved when components (A) and (B) are mixed and cured, and curing properties may be impaired. If x exceeds 3.0, the viscosity of the aqueous sodium silicate solution increases, which may impair mixing with component (B) and reduce workability at low temperatures.

[0024] The solids content of (A-1), excluding water, is preferably 30 to 50% by mass, more preferably 33 to 42% by mass, even more preferably 34 to 41% by mass, and most preferably 35 to 40% by mass. If the solids content of the sodium silicate aqueous solution is too high, it can be adjusted by diluting it with water. If the solids content is lower than 30% by mass, when components (A) and (B) are mixed and cured, a sufficient expansion ratio cannot be ensured, and the mechanical strength of the cured foam may decrease. If the solids content exceeds 50% by mass, the viscosity of the sodium silicate aqueous solution increases, which may impair its mixability with component (B) and reduce workability at low temperatures.

[0025] The solid content of (A-1) in the present invention refers to the ratio of components other than water contained in (A-1) to (A-1).

[0026] The (A-2) of the present invention contains a polyol (p-1) having at least one atom selected from the group consisting of bromine, phosphorus, and chlorine atoms in the molecule. The inclusion of (p-1) increases the specific gravity of the mixed organic phase when mixed with other polyols or when an amine catalyst is added, and when mixed with an aqueous sodium silicate solution, creaming of the organic layer is suppressed, making it difficult for the organic layer to float and separate.

[0027] Examples of (p-1) include brominated polyols having bromine atoms, phosphorus polyols having phosphorus atoms, chlorinated polyols having chlorine atoms, etc. The structure of the polyol is not particularly limited, and examples include those having a hydrocarbon, ether structure, ester structure, carbonate structure, etc.

[0028] (p-1) preferably contains at least one polyol having a specific gravity of 1.30 or more. Examples of polyols having a specific gravity of 1.30 or more include Ixol M125 (manufactured by Solvey) and EXOLIT OP550 (manufactured by CLARIANT). Note that the specific gravity in the present invention is the value at 25°C unless otherwise specified.

[0029] (A-2) may further contain a polyol other than (p-1), and examples of such polyols include polyether polyols, polyester polyols, and short-chain diols having a molecular weight of 200 or less.

[0030] Examples of polyether polyols that can be used include polyethylene ether polyol, polypropylene ether polyol, polyethylene polypropylene ether polyol, and polytetramethylene ether glycol.

[0031] As the polyester polyol, for example, a polyester polyol formed from adipic acid and a diol, which is a polycondensation type polyester polyol, or a polycaprolactone polyol, which is a lactone type polyester polyol, can be used.

[0032] Examples of short-chain diols having a molecular weight of 200 or less include ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 3-methyl-1,5-pentanediol, 1,8-octanediol, 1,3-cyclohexanedimethanol, 1,4-cyclohexanedimethanol, 1,9-nonanediol, 2-methyl-1,8-octanediol, 1,10-decamethylene glycol, 1,2-tetradecanediol, 2,4-diethyl-1,5-pentanediol, butylethylpropanediol, 1,3-cyclohexanedimethanol, 1,3-xylylene glycol, 1,4-xylylene glycol, diethylene glycol, triethylene glycol, and dipropylene glycol.

[0033] Furthermore, when (A-2) contains a polyol other than (p-1), the specific gravity of (A-2) is preferably 1.20 or more. If it is less than 1.20, the specific gravity of the organic phase decreases when an amine catalyst is added, and when mixed with an aqueous sodium silicate solution, the organic layer may easily float and separate due to creaming.

[0034] The content of (A-2) in component (A) is preferably 1 to 15% by mass. If it is less than 1% by mass, a sufficient expansion ratio may not be ensured, while if it exceeds 15% by mass, the viscosity of component (A) may increase, which may result in poor workability and reduced penetration into the ground during chemical injection.

[0035] Examples of (A-3) in the present invention include N,N,N',N'-tetramethylhexamethylenediamine, N,N,N',N'-tetramethylpropylenediamine, N,N,N',N',N"-pentamethyldiethylenetriamine, N,N',N'-trimethylaminoethylpiperazine, N,N,N',N'-tetramethylethylenediamine, bis-(dimethylaminoethyl)ether, N,N',N'-tris(3-dimethylaminopropyl)hexahydro-S-triamine, amine, 2-methyltriethylenediamine, N,N-dimethylaminoethylmorpholine, dimethylaminopropylimidazole, hexamethyltriethylenetetramine, hexamethyltripropylenetetramine, N,N,N-tris(3-dimethylaminopropyl)amine, N-methyl-N,N-bis(3-dimethylaminopropyl)amine, triethylenediamine, N-methylmorpholine, N-methylimidazole, N,N-dimethylethanolamine, N-methyl- N-(N',N'-dimethylaminoethyl)aminoethanol, N,N-dimethylethoxyethanol, 1,4-diazabicyclo[2.2.2]octane-2-methanol, 6-dimethylamino-1-hexanol, N',N-dimethylethoxy-N'-methyl-N'-ethylmethanol, N'',N''-dimethylamino-N'-methylethylamino-N-methyl-2-propanol, bis(2-dimethylaminoethylamino)-2-propanol, N'-[2-( Examples of such an amine include 2-[2-(dimethylamino)ethoxy]-N-[2-[2-(dimethylamino)ethoxy]ethyl]-N,N-dimethylethylenediamine, 3,3-iminobis(N,N-dimethyl-1-propanamine), N'-[2-(dimethylamino)methyl]-N,N-dimethylmethylenediamine, N,N,N',N'-tetraethyldiethylenetriamine, 2-[2-(dimethylamino)ethoxy]-N-[2-[2-(dimethylamino)ethoxy]ethyl]-ethanamine, and two or more of the above may be used in combination to adjust the reaction, etc.

[0036] The content of (A-3) in component (A) is preferably 0.1 to 5% by mass. If it is less than 0.1% by mass, there is a risk of deterioration in curing and a decrease in expansion ratio, while if it exceeds 5% by mass, it becomes difficult to control the reactivity and there is a risk of injection failure due to clogging of the resin during chemical injection.

[0037] The specific gravity of the mixture of (A-2) and (A-3) is preferably 1.15 or more. When the specific gravity of the mixture is 1.15 or more, the difference in specific gravity with the aqueous sodium silicate solution is small, and when mixed with the aqueous sodium silicate solution, creaming of the organic layer is suppressed, making it difficult for the organic layer to float and separate.

[0038] In the present invention, additives such as dispersion stabilizers can be used to further improve the dispersion stability of component (A) and to improve the compatibility between component (A) and component (B). Examples of dispersion stabilizers include anionic dispersion stabilizers, cationic dispersion stabilizers, and nonionic dispersion stabilizers.

[0039] Examples of the anionic dispersion stabilizer include alkyl carboxylates, alkyl sulfates, alkyl sulfonates, and alkyl phosphates.

[0040] Examples of cationic dispersion stabilizers include ammonium salts such as benzalkonium chloride.

[0041] Examples of nonionic dispersion stabilizers include glycerin fatty acid esters, alkyl polyethylene glycols, polyoxyethylene alkyl phenyl ethers, and alkyl glycosides.

[0042] These dispersion stabilizers can be used alone or in combination of two or more.

[0043] Component (B) in the present invention includes a mixture (B-1) (hereinafter also referred to as (B-1)) of diphenylmethane diisocyanate (hereinafter referred to as MDI) and polyphenylpolymethylene polyisocyanate (hereinafter referred to as polymeric MDI), or a reaction product of a polyol (B-2) (hereinafter referred to as (B-2)) having an active hydrogen and (B-1).

[0044] In the present invention, MDI includes various isomers of 4,4'-MDI, 2,4'-MDI, and 2,2'-MDI, and polymeric MDI means MDI to which one or more phenyl groups having an isocyanate group are added via methylene groups.

[0045] As for (B-1), the mass ratio of MDI to polymeric MDI is preferably MDI / polymeric MDI=35 / 65 to 75 / 25, more preferably 40 / 60 to 75 / 25. If the mass ratio of MDI is less than 35%, the viscosity of the polyisocyanate increases, which may result in poor resin fluidity during ground injection and a smaller area of ​​ground improvement, while if it exceeds 75%, the strength of the foamed resin may decrease.

[0046] Furthermore, the mass ratio of 4,4'-MDI to the total of 2,4'-MDI and 2,2'-MDI in the MDI is preferably 85 / 15 to 55 / 45, more preferably 80 / 20 to 55 / 45. If the total mass ratio of 2,4'-MDI and 2,2'-MDI is less than 15%, the low-temperature stability of the polyisocyanate may deteriorate, resulting in solidification, whereas if it exceeds 45%, the strength of the foamed resin may decrease.

[0047] Examples of (B-2) include polyether polyols, polyester polyols, hydrocarbon polyols, polycarbonate polyols, etc. From the viewpoint of the viscosity of the reaction product with (B-1), polyether polyols are preferred.

[0048] The polyether polyol preferably has a number average molecular weight of 400 to 4000, and the polyol may contain ethylene oxide (hereinafter, EO) units. There are no particular restrictions on the amount of EO units, but when they are contained, it is preferable that the amount is 60 to 90 mass%. There are no particular restrictions on the components other than the EO units in the polyether polyol, but propylene oxide (hereinafter, PO) units are preferred.

[0049] The amount of (B-2) incorporated into component (B) is preferably 0.5 to 20% by mass, more preferably 0.5 to 15% by mass. If it is less than 0.5% by mass, compatibility with polyol component (A) may be impaired, and the strength of the cured product may decrease during chemical injection. If it exceeds 15.0% by mass, the viscosity of the polyisocyanate may increase, which may impair resin flowability during ground injection and reduce the area of ​​ground improvement.

[0050] The (A-2) and (B-2) can be synthesized by known methods or commercially available products can be used.

[0051] In the present invention, a foam stabilizer may be used in component (B) to stabilize the cell size during foaming, and examples of the foam stabilizer include silicone-based foam stabilizers, such as polyoxyalkylenedimethylpolysiloxane copolymers and organopolysiloxanes.

[0052] When a foam stabilizer is used in the present invention, its content is preferably 3% by mass or less in component (B). If it exceeds 3% by mass, the strength of the resin may decrease.

[0053] Component (B) may also be used in combination with a viscosity reducer for the purpose of adjusting viscosity. Examples of viscosity reducers that have excellent compatibility with component (B), viscosity reducing properties, and mixing stability include alkylene carbonates such as propylene carbonate, and alkyl ethers and esters such as propylene glycol monomethyl ether acetate and diethylene glycol monomethyl ether acetate. From the viewpoints of the working environment and safety, the amount of these added to component (B) is preferably 1 to 5% by mass.

[0054] The grout composition for rock consolidation comprising the above-described components (A) and (B) can provide a consolidated body with excellent void-filling properties. [Example]

[0055] Examples of the present invention will be described in detail below, but the present invention is not limited to these examples. Unless otherwise specified, "%" in the examples is based on mass.

[0056] <Preparation of Polyol Component (A)> The polyol component was prepared according to the formulation shown in Table 1.

[0057] [Table 1]

[0058] The ingredients in Table 1 are as follows: Sodium silicate aqueous solution: solid content 40.5%, molar ratio (SiO2 / Na2O) = 2.0 (product name: No. 1 sodium silicate O0, manufactured by Toso Sangyo Co., Ltd.) Polyol A: Brominated polyol Ixol M125 (manufactured by Solvay), number average molecular weight 400, number of functional groups 2, specific gravity at 25°C 1.57 1,3-BG: 1,3-butanediol, molecular weight 90, functional group 2, specific gravity at 25°C 1.01 Polyol B: Polyethylene glycol, number average molecular weight 200, functionality 2, specific gravity at 25°C 1.12 EG: Ethylene glycol, molecular weight 62, functional groups 2, specific gravity at 25°C 1.11 DEG: Diethylene glycol, molecular weight 102, functional groups 2, specific gravity at 25°C 1.12 Catalyst 1: N-methyl-N-(N',N'-dimethylaminoethyl)aminoethanol (trade name: TOYOCAT RX5, manufactured by Tosoh Corporation), specific gravity at 25°C: 0.91 Catalyst 2: Triethylenediamine (trade name: TEDA L33, manufactured by Tosoh Corporation), specific gravity at 25°C: 1.03.

[0059] <Evaluation method for polyol components> The polyols (S-1 to S-15) shown in Table 1 were adjusted to a temperature of 20° C. and stirred at 1000 rpm for 1 minute using a Three-One Motor, then allowed to stand, and the time until the components separated was measured. A:60min or more C: Less than 60 minutes A rating of A is considered good.

[0060] The polyols rated C (S-13 to S-15) were not subjected to a foaming test.

[0061] <Preparation of Polyisocyanate Component (B)> <Preparation Example 1> A 1 L reactor equipped with a stirrer, thermometer, condenser, and nitrogen gas inlet tube was charged with 758.0 g of polyisocyanate 1, 179.0 g of diisocyanate 1, 20.1 g of diisocyanate 2, and 38.3 g of polyol 1, and the temperature was raised to 80°C. While maintaining the temperature, the mixture was mixed uniformly with a stirring blade and a urethane reaction was carried out for 3 hours. The mixture was then cooled to 60°C, 5.0 g of foam stabilizer was added, and the mixture was stirred for 30 minutes to obtain polyisocyanate composition (I-1) (NCO content 29.1%, viscosity at 25°C 110 mPa s).

[0062] <Preparation Example 2> A 1 L reactor equipped with a stirrer, thermometer, condenser, and nitrogen gas inlet tube was charged with 813.9 g of polyisocyanate 1, 111.2 g of diisocyanate 1, and 17.8 g of polyol 2, and the temperature was raised to 80°C. While maintaining the temperature, the mixture was mixed uniformly with a stirring blade for 3 hours to carry out a urethane reaction. The mixture was then cooled to 60°C, and 47.6 g of diluent and 9.5 g of foam stabilizer were added. The mixture was stirred for 30 minutes to obtain polyisocyanate composition (I-2) (NCO content 28.6%, viscosity at 25°C 130 mPa s).

[0063] <Preparation Example 3> A 1 L reactor equipped with a stirrer, thermometer, condenser, and nitrogen gas inlet tube was charged with 494.4 g of polyisocyanate 1, 448.2 g of diisocyanate 1, and 49.5 g of polyol 3, and the temperature was raised to 80°C. While maintaining the temperature, the mixture was mixed uniformly with a stirring blade to carry out a urethane reaction for 3 hours. The mixture was then cooled to 60°C, 7.9 g of a foam stabilizer was added, and the mixture was stirred for 30 minutes to obtain polyisocyanate composition (I-3) (NCO content 29.3%, viscosity at 25°C 100 mPa s).

[0064] [Table 2]

[0065] The ingredients in Table 2 are as follows: Polyisocyanate 1: MDI / polymeric MDI = 40 / 60 (PA ratio), total of 2,4'-MDI and 2,2'-MDI in MDI / 4,4'-MDI = 3 / 97 (mass ratio), NCO content 31.0% (product name: MR-200, manufactured by Tosoh Corporation) Diisocyanate 1: MDI / polymeric MDI = 100 / 0 (PA ratio), total of 2,4'-MDI and 2,2'-MDI in MDI / 4,4'-MDI = 55 / 45 (mass ratio), NCO content 33.5% (trade name: Millionate NM, manufactured by Tosoh Corporation) Diisocyanate 2: MDI / polymeric MDI = 100 / 0 (PA ratio), total of 2,4'-MDI and 2,2'-MDI in MDI / 4,4'-MDI = 99 / 1 (mass ratio), NCO content 33.5% (trade name: Millionate MT, manufactured by Tosoh Corporation) Polyol 1: PO-based polyether polyol, number average molecular weight 4000, functionality 2 Polyol 2: PO-based polyether polyol, number average molecular weight 400, functionality 2 Polyol 3: PO / EO polyether polyol, number average molecular weight 400, functionality 2, EO content 75% Foam stabilizer: Siloxane-polyalkylene oxide copolymer (product name: NIAX SILICONE Y-16136, manufactured by MOMENTIVE) Diluent: Propylene carbonate (product name: Propylene Carbonate S, manufactured by BASF) The MDI / polymeric MDI ratios of Polyisocyanate 1, Diisocyanate 1, and Diisocyanate 2 are the peak area ratios (PA ratios) obtained by GPC measurement, and represent (MDI monomer peak area) / (sum of peak areas of MDI oligomers other than MDI monomer). The PA ratio can be treated essentially as the mass ratio.

[0066] The GPC measurement conditions are as follows: (1) Measuring instrument: HLC-8220 (manufactured by Tosoh Corporation) (2) Column: TSKgel (Tosoh Corporation) G3000H-XL G2500H-XL G2000H-XL G1000H-XL (3) Carrier: THF (tetrahydrofuran) (4) Detector: RI (refractive index) detector (5) Temperature: 40℃ (6)Flow rate: 1.000ml / min (7) Calibration curve: Standard polystyrene (manufactured by Tosoh Corporation) ·F-80 (molecular weight: 7.06×10 5 , molecular weight distribution: 1.05) ·F-20 (molecular weight: 1.90×10 5 , molecular weight distribution: 1.05) ·F-10 (molecular weight: 9.64×10 4 , molecular weight distribution: 1.01) ·F-2 (molecular weight: 1.81×10 4 , molecular weight distribution: 1.01) ·F-1 (molecular weight: 1.02×10 4 , molecular weight distribution: 1.02) ·A-5000 (molecular weight: 5.97×10 3 , molecular weight distribution: 1.02) ·A-2500 (molecular weight: 2.63×10 3 , molecular weight distribution: 1.05) ·A-500 (molecular weight: 5.0×102 , molecular weight distribution: 1.14) (8) Sample solution concentration: 0.5% THF solution.

[0067] <Reaction behavior and various evaluation methods> A foaming test was carried out using the polyol component (A) and polyisocyanate component (B) in the formulation shown in Table 3. The stirring conditions were a liquid temperature of 20°C, stirring at 400 rpm for 10 seconds using a Three-One motor, and the results are shown in Table 3.

[0068] [Table 3]

[0069] In the reactivity test, "free foaming" refers to blending component (A) and component (B) in a 1 L cup under the above conditions, mixing and stirring, and allowing foaming to occur in the cup. "Foaming in water" refers to blending component (A) and component (B) in a 1 L cup under the above conditions, mixing and stirring, and then quickly pouring 100 mL of the blended liquid into another 1 L cup containing 500 mL of water, and stirring the water vigorously with a stirring rod for 30 seconds to allow foaming.

[0070] Cream time: The time (seconds) from the start of mixing and stirring the polyol component (A) and the polyisocyanate component (B) until the mixture becomes cloudy and creamy and the liquid surface rises. Rise time: The time (seconds) from the start of mixing and stirring the polyol component (A) and the polyisocyanate component (B) until the compounded liquid foams and reaches its maximum height.

[0071] · Expansion ratio: The expansion ratio during free expansion is calculated using the following formula. Expansion ratio (times) = volume of foamed product (cm 3 ) / volume of the mixture before foaming (cm 3 ) Water turbidity after foaming: In the underwater foaming test, the turbidity of the water was measured using a turbidity meter (TURBIDIMETER 2100N, manufactured by HACH) as an indicator of water contamination after the rise time had finished. A turbidity of 20 NTU or less is considered to be good.

[0072] Foaming after foaming: In the underwater foaming test, foaming of water is measured as an indicator of water contamination after the rise time has finished. 125 mL of the water used in the underwater foaming test after the rise time has finished is placed in a 250 mL polyethylene bottle, sealed, shaken vigorously for 10 seconds, and then allowed to stand. The time (seconds) until the foam disappears from the water surface is measured. A time of 60 seconds or less is considered good.

Claims

1. A grouting composition for rock consolidation comprising a polyol component (A) and a polyisocyanate component (B), wherein the polyol component (A) comprises a sodium silicate aqueous solution (A-1), a polyol (A-2) containing a polyol (p-1) having at least one atom selected from the group consisting of bromine atoms, phosphorus atoms, and chlorine atoms in the molecule, and a tertiary amine catalyst (A-3), and the polyisocyanate component (B) is a mixture (B-1) of diphenylmethane diisocyanate and polyphenylpolymethylene polyisocyanate, or a reaction product of a polyol (B-2) having active hydrogen and (B-1).

2. The mass ratio of diphenylmethane diisocyanate and polyphenylpolymethylene polyisocyanate (B-1) in the polyisocyanate component (B) is 35 / 65 to 75 / 25, and the mass ratio of 4,4'-diphenylmethane diisocyanate in diphenylmethane diisocyanate to the total of 2,2'-diphenylmethane diisocyanate and 2,4'-diphenylmethane diisocyanate is 85 / 15 to 55 / 45. The grouting composition for rock consolidation according to claim 1, characterized in that

3. The grouting composition for rock consolidation according to claim 1 or 2, characterized in that (p-1) contained in (A-2) in the polyol component (A) contains at least one polyol having a specific gravity of 1.30 or more at 25 ° C.

4. The grouting composition for rock consolidation according to any one of claims 1 to 3, characterized in that (A-2) in the polyol component (A) is a mixed polyol of (p-1) and a polyol other than (p-1), and the specific gravity of the mixed polyol at 25 ° C. is 1.20 or more.

5. The mixture of (A-2) and (A-3) in the polyol component (A) has a specific gravity of 1.15 or more at 25 ° C. The grouting composition for rock consolidation according to any one of claims 1 to 4.

6. 6. The grout composition for rock consolidation according to claim 1, wherein the polyol component (A) contains a dispersant.

7. 7. The grout composition for rock consolidation according to claim 1, wherein the polyisocyanate component (B) contains a viscosity reducer.

8. 8. The grout composition for rock consolidation according to claim 1, wherein the polyisocyanate component (B) contains a foam stabilizer.

9. A solidified body obtained from the grout composition for rock consolidation according to any one of claims 1 to 8.

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