Grouting reinforcement material and preparation method and application thereof

Abstract

The invention discloses a grouting reinforcement material and a preparation method and application thereof, and the method comprises the following steps: mixing a sodium silicate aqueous solution, a chain extension cross-linking agent, distilled water and a composite catalyst to obtain a component A; reacting the polymethylene polyphenyl polyisocyanate with polyether polyol to obtain an isocyanate prepolymer, and carrying out self-polymerization on the polymethylene polyphenyl polyisocyanate under the action of a catalyst to obtain an isocyanate polymer; the preparation method comprises the following steps: mixing a component A and a component B according to a mass ratio of (1.2: 1)-(1: 1.2), then stirring an isocyanate prepolymer, an isocyanate polymer, a plasticizer and a diluent at room temperature and constant temperature to obtain the component B, and finally mixing the component A and the component B according to a mass ratio of (1.2: 1)-(1: 1.2) to obtain the target grouting reinforcement material. The invention aims to realize effective compounding of an organic phase and an inorganic phase, and the prepared reinforcing material has early strength and toughening, low heat release, and environment-friendly grouting performance capable of being cured in water.

Description

Technical Field

[0001] The present invention relates to the technical field of reinforcement materials, and particularly relates to a grouting reinforcement material, a preparation method thereof, and an application thereof. Background Art

[0002] Currently, the grouting reinforcement technology uses a high-pressure device to quickly inject grouting materials (such as cement slurry, chemical grouting materials, etc.) into damaged projects. Traditional chemical grouting materials often use materials such as cement slurry or a mixture of water glass and cement for grouting reinforcement. Such grouting materials have the characteristics of low cost and convenient and fast construction, but they also have disadvantages such as high brittleness, long gel time, long curing time, and high viscosity, making it difficult to penetrate into fine cracks or even the soil; while new chemical grouting materials often use polyurethane chemical grouting materials, which have the characteristics of high strength, good toughness, adjustable viscosity, adjustable gel time and curing time, and high bonding strength of the reinforcement material, but they have high cost, are not environmentally friendly, have a large amount of heat generated during the reaction, and have a risk of smoldering.

[0003] The existing patent with the publication number CN109233259A discloses an organic-inorganic composite reinforcement material and a preparation method thereof. It is composed of two components, A and B; Component A includes raw materials in the following weight parts: 40-100 parts of polyisocyanate, 5-10 parts of defoamer, 2-8 parts of plasticizer, 10-30 parts of auxiliary plasticizer, 1-8 parts of rigid foam polyether, and 0.1-0.3 parts of polymerization inhibitor; Component B includes raw materials in the following weight parts: 75-95 parts of water glass, 5-10 parts of small molecule cross-linking agent, and 0.5-1.5 parts of catalyst. Although this patent realizes the combined use of organic and inorganic types, there may be a risk of phase separation in the mixture of organic and inorganic materials, especially under different temperature and humidity conditions. At the same time, the highest reaction temperature in this patent is 94.1 °C. Although it is lower than that of traditional polyurethane, whether this temperature may still cause local overheating, especially during large-scale construction, heat accumulation may lead to uneven material performance and even safety hazards. Summary of the Invention

[0004] The main purpose of the present invention is to provide a grouting reinforcement material, a preparation method thereof, and an application thereof, aiming to solve the technical problem that there are still safety hazards in the combination of existing organic and inorganic materials.

[0005] To achieve the above object, the present invention provides a preparation method of a grouting reinforcement material, and the method includes the following steps:

[0006] Step 1, uniformly stir and mix an aqueous sodium silicate solution, a chain extender cross-linking agent, distilled water, and a composite catalyst in a preset mass ratio to obtain Component A;

[0007] Step 2: Add polymethylene polyphenyl polyisocyanate of a preset quality into a reaction kettle, charge nitrogen for protection, stir and heat up to 40°C - 45°C, dropwise add polyether polyol of a preset quality while stirring, control the temperature below 60°C during the dropping process, keep the temperature constant for a preset time after the dropping is completed, then continue to heat up to 80°C - 85°C, keep the temperature constant at 80°C for 1 - 3 hours, and after cooling to room temperature, obtain an isocyanate prepolymer;

[0008] Step 3: Add polymethylene polyphenyl polyisocyanate of a preset quality into a reaction kettle, charge nitrogen for protection, stir and heat up to 50°C - 60°C, add a preset quality of catalyst, keep the temperature constant at 60°C for 1 - 3 hours, add phosphoric acid accounting for 0.05% - 0.1% of the mass of polymethylene polyphenyl polyisocyanate to terminate the reaction after the reaction ends, and cool to room temperature to obtain an isocyanate polymer;

[0009] Step 4: Keep the preset quality of isocyanate prepolymer, isocyanate polymer, plasticizer and diluent stirred at a constant temperature of 25 - 30°C for 30 - 60 minutes at room temperature to obtain Component B;

[0010] Step 5: Mix Component A and Component B according to a mass ratio of (1.2:1) to (1:1.2) to obtain the target grouting reinforcement material.

[0011] Optionally, Component A includes 80 - 100 parts of sodium silicate aqueous solution, 0 - 15 parts of chain extender crosslinking agent, 0 - 8 parts of distilled water, and 0 - 2 parts of composite catalyst by mass. The Baumé degree of the sodium silicate aqueous solution is 40 - 50, the modulus of the sodium silicate aqueous solution is 2.0 - 3.0, and the viscosity of Component A is 100 - 300 mPa·s.

[0012] Optionally, Component B includes 30 - 80 parts of isocyanate prepolymer, 0 - 30 parts of isocyanate polymer, 18 - 26 parts of plasticizer, and 5 - 15 parts of diluent by mass. The viscosity of Component B is 90 - 300 mPa·s.

[0013] Optionally, the polyether polyol includes at least one of polyether polyol 3Y - 208, 3Y - 28 - 00, and 3Y - 28 - 82.

[0014] Optionally, the chain extender crosslinking agent includes glycerol.

[0015] Optionally, the composite catalyst is composed of CUCAT - WNT05A and DMP - 30 in combination.

[0016] Optionally, the diluent includes at least one of propylene carbonate, propylene glycol methyl ether acetate, diethylene glycol ethyl ether acetate, ethylene glycol diacetate, N,N-dimethylformamide, and glycol ether ester, and the plasticizer includes at least one of dibutyl phthalate, diethylene glycol ethyl ether acetate, dioctyl phthalate, dioctyl adipate, didodecyl adipate, and dioctyl terephthalate.

[0017] Optionally, the catalyst added in step 3 is DMP-30, and the mass of DMP-30 is 0.05% of the mass of the added isocyanate.

[0018] In addition, to achieve the above object, the present invention also provides a grouting reinforcement material prepared by the method described in any one of the above.

[0019] In addition, to achieve the above object, the present invention also provides the application of the grouting reinforcement material prepared by the method described above or the above grouting reinforcement material in frozen soil subgrade, water-rich dam tunnels, and coal mine reinforcement projects.

[0020] Beneficial effects:

[0021] The grouting reinforcement material of the present invention is obtained by mixing an aqueous sodium silicate solution, a chain extender crosslinking agent, distilled water, and a composite catalyst to obtain component A, and reacting polymethylene polyphenyl polyisocyanate with polyether polyol to obtain an isocyanate prepolymer, and self-polymerizing polymethylene polyphenyl polyisocyanate under the action of a catalyst to obtain an isocyanate polymer; then stirring the isocyanate prepolymer, the isocyanate polymer, a plasticizer, and a diluent at a constant temperature at room temperature to obtain component B, and finally mixing component A and component B to obtain the target grouting reinforcement material. The purpose of this invention is to effectively compound the organic phase and the inorganic phase. Water can be used not only as a diluent for component A but also as a chain extender for isocyanate. Water reacts with isocyanate to form CO2 through a chain extension reaction; the chain extender crosslinking agent reacts with isocyanate, which can increase the hard segment content of polyurethane. The higher the hard segment content, the higher the strength of the consolidated body after curing; in addition, CUCAT-WNT05A, as an amine catalyst, can catalyze the reaction of isocyanate with water or the chain extender crosslinking agent, and DMP-30, as an isocyanate trimerization catalyst, can further catalyze the self-polymerization of isocyanate into a trimer during the mixing reaction of the two components, further increasing the content of the rigid structure of the material and thus enhancing the strength of the material. Finally, the prepared reinforcement material has the properties of early strength and toughness enhancement, low heat release, and environmental protection grouting that can be cured in water. It can be applied to non-excavation and non-destructive reinforcement and repair of diseases in frozen soil subgrade, water-rich dam tunnels, coal mines and other facilities. Description of the drawings

[0022] Figure 1 It is a schematic flow chart of an embodiment of a preparation method of a grouting reinforcement material of the present invention;

[0023] Figure 2Schematic diagram of the stress-strain test results of Embodiment 1 of the present invention;

[0024] Figure 3 Schematic diagram of the stress-strain test results of Embodiment 2 of the present invention;

[0025] Figure 4 Schematic diagram of the stress-strain test results of Embodiment 3 of the present invention.

[0026] The realization, functional features and advantages of the object of the present invention will be further described in conjunction with the embodiments with reference to the drawings. Detailed implementation manners

[0027] It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0028] As Figure 1 shown, the present invention provides a flow schematic diagram of an embodiment of a preparation method of a grouting reinforcement material. Among them, the method includes the following steps:

[0029] Step 1, stir and mix evenly an aqueous sodium silicate solution, a chain extender crosslinking agent, distilled water, and a composite catalyst in a preset mass ratio to obtain Component A. Among them, Component A includes 80-100 parts by mass of the aqueous sodium silicate solution, 0-15 parts of the chain extender crosslinking agent, 0-8 parts of distilled water, and 0-2 parts of the composite catalyst. The Baume degree of the aqueous sodium silicate solution is 40-50, the modulus of the aqueous sodium silicate solution is 2.0-3.0, and the viscosity of Component A is 100-300 mPa·s; preferably, the composite catalyst is composed of CUCAT-WNT05A and DMP-30. The catalyst CUCAT-WNT05A is purchased from Guangzhou Yourun Synthetic Materials Co., Ltd., and the catalyst DMP-30 is 2,4,6-tris(dimethylaminomethyl)phenol, purchased from Xindian Chemical Materials (Shanghai) Co., Ltd., and the distilled water plays a dilution effect and has environmental protection. The chain extender crosslinking agent includes glycerol.

[0030] Step 2: Add polymethylene polyphenylene polyisocyanate of a preset quality into a reaction kettle, fill it with nitrogen for protection, stir and heat up to 40°C - 45°C, and while stirring, dropwise add polyether polyol of a preset quality. During the dropping process, control the temperature to be less than 60°C. After the dropping is completed, keep it at a constant temperature for a preset time, then continue to heat up to 80°C - 85°C, keep it at 80°C for 1 - 3 hours, and after cooling to room temperature, obtain an isocyanate prepolymer, the structure of which is a substance with isocyanate groups -NCO at both ends. Among them, the polymethylene polyphenylene polyisocyanate is preferably pm-200, purchased from Shandong Wanhua Energy Saving Technology Group Co., Ltd. The polyether polyol includes at least one of polyether polyol 3Y-208, 3Y-28-00, and 3Y-28-82. The above three polyether polyols are purchased from Jiangsu Zhongshan Chemical Co., Ltd. And in this step, the isocyanate prepolymer is prepared by pre-polymerizing polymethylene polyphenylene polyisocyanate and bifunctional polyether polyol, so that the molecular weight distribution of the obtained polymer resin is relatively narrow, and the molecular structural units are relatively regular. Compared with direct mixing, it is beneficial to improve the toughness of the material. At the same time, part of the -NCO groups react with -OH in advance, reducing the heat generated by the reaction and lowering the highest reaction temperature of the subsequent two-component mixing.

[0031] Step 3: Add polymethylene polyphenylene polyisocyanate PAPI of a preset quality into a reaction kettle, fill it with nitrogen for protection, stir and heat up to 50°C - 60°C, add a preset quality of catalyst, keep it at 60°C for 1 - 3 hours, and after the reaction is completed, add phosphoric acid accounting for 0.05% - 0.1% of the mass of polymethylene polyphenylene polyisocyanate to terminate the reaction, and cool to room temperature to obtain an isocyanate poly-mer. Among them, the polymethylene polyphenylene polyisocyanate is pm-200, purchased from Wanhua Energy Saving Technology Group Co., Ltd. And the isocyanate poly-mer contains a ring structure, and its structure is a substance with isocyanate groups -NCO at both ends. And the catalyst in this step is DMP-30, which is used as a trimerization catalyst for isocyanate in this step, and the mass of DMP-30 is 0.05% of the mass of the added polymethylene polyphenylene polyisocyanate. Its mechanism of action is that the free monomers or isocyanate groups in polyisocyanate pm-200 can self-polymerize to form trimers under the action of a certain temperature (50°C - 60°C) and catalyst DMP-30; the polyisocyanate pm-200 also contains low-polymer isocyanates with 3 - 6 functionality, which can also self-polymerize to form trimers under the action of a certain temperature (50°C - 60°C) and catalyst DMP-30.

[0032] Among them, the specific reaction process of polymethylene polyphenylene polyisocyanate self-polymerizing to form trimers under heating and the catalysis of catalyst (DMP-30) is as follows:

[0033]

[0034] Step 4: Prepolymer of isocyanate, polyisocyanate, plasticizer and diluent with a preset quality are stirred at a constant temperature of 25 - 30°C for 30 - 60 minutes at room temperature to obtain Component B. Among them, Component B includes 30 - 80 parts by mass of prepolymer of isocyanate, 0 - 30 parts by mass of polyisocyanate, 18 - 26 parts by mass of plasticizer, 5 - 15 parts by mass of diluent, and the viscosity of Component B is 90 - 300 mPa·s. And in the preparation of Component B, the polyisocyanate is prepared in advance. Both the trimer and the polyisocyanate contain a rigid six-membered ring structure, which can further improve the strength of the material and play an important role in early strength and high strength. At the same time, the polyisocyanate is similar to a spherical structure, and has less influence on the viscosity of the component compared with the chain structure of the prepolymerized polyurethane resin (there is molecular entanglement in the linked structure). Preferably, the diluent includes at least one of propylene carbonate, propylene glycol methyl ether acetate, diethylene glycol ethyl ether acetate, ethylene glycol diacetate, N,N-dimethylformamide, and glycol ether ester, and the plasticizer includes at least one of dibutyl phthalate, diethylene glycol ethyl ether acetate, dioctyl phthalate, dioctyl adipate, didecyl adipate, and dioctyl terephthalate.

[0035] Step 5: The preset quality of Component A and Component B are mixed to obtain the target grouting reinforcement material. Among them, the mass ratio of Component A to Component B is (1.2:1) - (1:1.2). And the curing time of the grouting reinforcement material can be adjusted with the change of the catalyst dosage. The heat release is small, and the strength of the consolidated body remains above 50 MPa. It can be used for non-excavation and non-destructive reinforcement and repair of diseases in facilities such as frozen soil subgrade, water-rich dam tunnels, and coal mines. The specific reaction process includes: The water in Component A reacts with the isocyanate group -NCO for chain extension as follows:

[0036] NCO-R-NCO + 2H2O → H2N-R-NH2 + 2CO2;

[0037] The amino compound generated by the chain extension reaction can further react with the isocyanate group -NCO to generate substituted urea, thereby increasing the content of the hard segment of the polymer and improving the strength of the consolidated body. The specific reaction formula is as follows:

[0038] NCO-R-NCO + H2N-R-NH2 → NCO-R-NH-CO-NH-R-NH2

[0039] And the chain extension cross-linking agent in Component A reacts with the isocyanate group -NCO as follows:

[0040]

[0041] And the sodium silicate solution in Component A can also absorb CO2. The specific reaction equation is as follows:

[0042] Na2SiO3 + CO2 + H2O → Na2CO3 + H2SiO3↓;

[0043] The silicic acid formed by the reaction is unstable and easily further associates into polysilicic acid. The specific reaction equation is as follows:

[0044] H2SiO3 + H2O → mSiO2·nH2O;

[0045] The polysilicic acid will further condense into a three-dimensional network structure of SiO2 (inorganic silicate network structure):

[0046]

[0047] It can be seen that the crosslinking density of the inorganic silicate network structure is large. The more the content per unit volume, the greater the strength of the material.

[0048] Furthermore, in order to better illustrate the grouting reinforcement material of the present invention, the following is illustrated by specific examples.

[0049] Example 1

[0050] In this example, the sodium silicate aqueous solution in component A has a Baume degree of 45A and a modulus of 2.7, and is purchased from Foshan Zhongfa Water Glass Factory. The chain extender crosslinking agent is glycerol; the composite catalyst is composed of CUCAT-WNT05A and DMP-30.

[0051] In component B, the polymethylene polyphenyl polyisocyanate is pm-200, purchased from Wanhua Energy Saving Technology Group Co., Ltd.; the polyether polyol model is polyether 3Y-208, with a hydroxyl value of 56 and a functionality of 2. The plasticizer is dibutyl phthalate (DBP). The diluent is propylene carbonate.

[0052] Step 1.1, Mix 90 parts of the sodium silicate aqueous solution, 10 parts of the chain extender crosslinking agent, and 0.85 parts of the composite catalyst and stir for 1 hour to mix evenly to obtain component A, which is sealed and stored for later use.

[0053] Step 1.2, Add 72.25 g of polymethylene polyphenyl polyisocyanate to the reaction kettle, charge nitrogen for protection, stir and heat up to 40 °C, and while stirring, dropwise add 3.75 g of polyether polyol. During the dropping process, control the temperature to be less than 60 °C. After the dropping is completed, keep the temperature constant for 10 minutes, then continue to heat up to 80 °C, keep the temperature constant at 80 °C for 2 hours, and cool down to room temperature, and seal and store for later use.

[0054] Step 1.3, Mix 75 parts of the prepolymer obtained in step 1.2, 20 parts of the plasticizer, and 5 parts of the diluent at a constant temperature of 25 °C for 60 minutes and stir evenly to obtain component B, which is sealed and stored for later use.

[0055] Step 1.4, mix the above-prepared Component A and Component B according to a certain mass ratio to obtain the grouting reinforcement material 1.

[0056] Example 2

[0057] In this example, the sodium silicate aqueous solution in Component A has a Baume degree of 45A and a modulus of 2.7, and is purchased from Foshan Zhongfa Water Glass Factory. The chain extender crosslinking agent is glycerol. The composite catalyst is composed of CUCAT-WNT05A and DMP-30.

[0058] In Component B, the polymethylene polyphenyl polyisocyanate is pm-200, purchased from Wanhua Energy Saving Technology Group Co., Ltd. The polyether polyol model is polyether 3Y-208, with a hydroxyl value of 56 and a functionality of 2. The plasticizer is dibutyl phthalate (DBP). The diluent is propylene carbonate.

[0059] Step 2.1, add 90 parts of sodium silicate aqueous solution, 10 parts of chain extender crosslinking agent, and 0.85 parts of composite catalyst, stir for 1 hour to mix evenly to obtain Component A, and seal and store for later use.

[0060] Step 2.2, add 95 g of polymethylene polyphenyl polyisocyanate to the reaction kettle, charge with nitrogen for protection, stir and heat up to 40 °C, dropwise add 7.5 g of polyether polyol while stirring, control the temperature below 60 °C during the dropping process, keep the temperature constant at 10 minutes after the dropping is completed, then continue to heat up to 80 °C, keep the temperature constant at 80 °C for 2 hours, cool down to room temperature, and seal and store for later use.

[0061] Step 2.3, add 60 g of polymethylene polyphenyl polyisocyanate to the reaction kettle, charge with nitrogen for protection, stir and heat up to 60 °C, add 0.03 g of catalyst DMP-30, keep the temperature constant at 60 °C for 2 hours, add 0.05 g of phosphoric acid to terminate the reaction after the reaction is completed, cool down to room temperature, and seal and store for later use.

[0062] Step 2.4, add 51.25 parts of the prepolymer obtained in Step 2.2, 23.75 parts of the polymer obtained in Step 2.3, 20 parts of plasticizer, and 5 parts of diluent, stir evenly at a constant temperature of 25 °C for 60 minutes at room temperature to obtain Component B, and seal and store for later use.

[0063] Step 2.5, mix the above-prepared Component A and Component B according to a certain mass ratio to obtain the grouting reinforcement material 2.

[0064] Example 3

[0065] In this example, the sodium silicate aqueous solution in Component A has a Baume degree of 45A and a modulus of 2.7, and is purchased from Foshan Zhongfa Water Glass Factory. The chain extender crosslinking agent is glycerol. The composite catalyst is composed of CUCAT-WNT05A and DMP-30.

[0066] The polymethylene polyphenyl polyisocyanate in Component B is pm-200, purchased from Wanhua Energy Saving Technology Group Co., Ltd. The polyether polyol model is Polyether 3Y-208, with a hydroxyl value of 56 and a functionality of 2. The plasticizer is dibutyl phthalate (DBP). The diluent is propylene carbonate.

[0067] Step 3.1: Mix 90 parts of sodium silicate aqueous solution, 10 parts of chain extender crosslinker, and 0.85 parts of composite catalyst by stirring for 1 hour to obtain Component A, which is sealed and stored for later use.

[0068] Step 3.2: Add 72.5 g of polymethylene polyphenyl polyisocyanate to the reaction kettle, fill with nitrogen for protection, stir and heat up to 40 °C, and dropwise add 7.5 g of polyether polyol while stirring. During the dropping process, control the temperature below 60 °C. After the dropping is completed, keep the temperature constant for 10 minutes, then continue to heat up to 80 °C, keep the temperature constant at 80 °C for 2 hours, cool down to room temperature, and seal and store for later use.

[0069] Step 3.3: Add 60 g of polymethylene polyphenyl polyisocyanate to the reaction kettle, fill with nitrogen for protection, stir and heat up to 60 °C, add 0.03 g of catalyst DMP-30, keep the temperature constant at 60 °C for 2 hours. After the reaction is completed, add 0.05 g of phosphoric acid to terminate the reaction, cool down to room temperature, and seal and store for later use.

[0070] Step 3.4: Mix 40 parts of the prepolymer obtained in Step 3.2, 35 parts of the polymer obtained in Step 3.3, 20 parts of plasticizer, and 5 parts of diluent, and stir evenly at a constant temperature of 25 °C for 60 minutes at room temperature to obtain Component B, which is sealed and stored for later use.

[0071] Step 3.5: Mix the above-prepared Component A and Component B in a certain mass ratio to obtain the grouting reinforcement material 3.

[0072] Comparative Example 1

[0073] The sodium silicate aqueous solution in Component A of this example has a Baume degree of 45A and a modulus of 2.7, and is purchased from Foshan Zhongfa Water Glass Factory. The chain extender crosslinker is glycerol. The composite catalyst is composed of CUCAT-WNT05A and DMP-30.

[0074] The polymethylene polyphenyl polyisocyanate in Component B is pm-200, purchased from Wanhua Energy Saving Technology Group Co., Ltd. The polyether polyol model is Polyether 3Y-208, with a hydroxyl value of 56 and a functionality of 2. The plasticizer is dibutyl phthalate (DBP). The diluent is propylene carbonate.

[0075] Step 1.1: Take 90 parts of sodium silicate aqueous solution, 10 parts of chain extender crosslinking agent, and 0.85 parts of composite catalyst, stir for 1 hour to mix evenly to obtain Component A, and store it sealed for later use.

[0076] Step 1.2: Add 60 g of polymethylene polyphenyl polyisocyanate into the reaction kettle, fill with nitrogen for protection, stir and heat up to 60 °C, add 0.03 g of catalyst DMP-30, keep the temperature constant at 60 °C for 2 hours. After the reaction is completed, add 0.05 g of phosphoric acid to terminate the reaction, add 20 parts of plasticizer and 5 parts of diluent, and stir at room temperature of 25 °C to obtain Component B, and store it sealed for later use.

[0077] Step 1.3: Mix the above-prepared Component A and Component B according to a certain mass ratio to obtain the grouting reinforcement material.

[0078] Comparative Example 2: A product purchased from Wanhua Energy Saving Technology Group Co., Ltd.

[0079] Perform compressive strength, reaction temperature and failure deformation tests on the grouting reinforcement materials prepared in the above Examples 1-3 and the corresponding materials of Comparative Examples 1-2, and finally obtain the results shown in Table 1.

[0080] Table 1 Performance of Grouting Reinforcement Materials

[0081]

[0082] As can be seen from Table 1 above, the 1-hour strength of the grouting reinforcement materials in the embodiments of the present invention is greater than 30 MPa, the 24-hour strength is also greater than 50 MPa, and the underwater curing 24-hour strength can reach 42.5 MPa in Example 1, 43.07 MPa in Example 2, and 45.17 MPa in Example 3, all of which are greater than the reinforcement materials in Comparative Examples 1-2; at the same time, the highest reaction temperature < 90 °C, which is lower than the highest reaction temperature of the commonly used polyurethane-modified sodium silicate grouting reinforcement materials on the market, and the viscosities of Component A and Component B are at low viscosity. During grouting reinforcement, it has excellent permeability, and the compression deformation rate ≥ 34%, with good toughness.

[0083] Furthermore, stress-strain tests were carried out on the reinforcement materials in Examples 1-3, and the specific results are as Figures 2-4 shown. Among them, when the strain is 32-36%, the stress peak can reach above 50 MPa.

[0084] Furthermore, the reinforcement materials in Examples 1-3 were subjected to acute oral toxicity tests according to GB 15193.3-2014 "National Food Safety Standard". Under the conditions of this test, the extract of the test sample had an acute oral LD 50 > 5000 mg / kg for ICR mice. According to the acute toxicity classification, the test sample belongs to the non-toxic class.

[0085] It should be noted that in this document, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, such that a process, method, article or system comprising a series of elements includes not only those elements but also other elements not expressly listed, or further includes elements inherent to such process, method, article or system. Without further limitation, an element defined by the statement "comprising one..." does not exclude the existence of additional identical elements in the process, method, article or system comprising such element.

[0086] The serial numbers of the embodiments of the present invention above are for description only and do not represent the superiority or inferiority of the embodiments.

[0087] The above are only the preferred embodiments of the present invention, and do not limit the patent scope of the present invention accordingly. Any equivalent structure or equivalent process transformation made by using the content of the specification and drawings of the present invention, or directly or indirectly applied in other related technical fields, shall equally be included in the patent protection scope of the present invention.

Claims

1. A preparation method of a grouting reinforcement material, characterized in that, The method includes the following steps: Step 1: Stir and mix evenly an aqueous sodium silicate solution, a chain extender crosslinking agent, distilled water, and a composite catalyst in a preset mass ratio to obtain Component A; Step 2: Add a preset mass of polymethylene polyphenyl polyisocyanate into a reaction kettle, fill it with nitrogen for protection, stir and heat up to 40°C - 45°C, dropwise add a preset mass of polyether polyol while stirring, control the temperature below 60°C during the dropping process, keep the temperature constant for a preset time after the dropping is completed, then continue to heat up to 80°C - 85°C, keep the temperature constant at 80°C for 1 - 3 hours, and after cooling to room temperature, obtain an isocyanate prepolymer; Step 3: Add a preset mass of polymethylene polyphenyl polyisocyanate into a reaction kettle, fill it with nitrogen for protection, stir and heat up to 50°C - 60°C, add a preset mass of catalyst, keep the temperature constant at 60°C for 1 - 3 hours, add phosphoric acid accounting for 0.05% - 0.1% of the mass of polymethylene polyphenyl polyisocyanate to terminate the reaction after the reaction ends, and cool to room temperature to obtain an isocyanate polymer; Step 4: Keep the temperature constant and stir a preset mass of isocyanate prepolymer, isocyanate polymer, plasticizer, and diluent at room temperature of 25 - 30°C for 30 - 60 minutes to obtain Component B; Step 5: Mix Component A and Component B according to a mass ratio of (1.2:1) to (1:1.2) to obtain the target grouting reinforcement material.

2. The preparation method of the grouting reinforcement material according to claim 1, characterized in that, Component A includes, by mass, 80 - 100 parts of aqueous sodium silicate solution, 0 - 15 parts of chain extender crosslinking agent, 0 - 8 parts of distilled water, 0 - 2 parts of composite catalyst. The Baume degree of the aqueous sodium silicate solution is 40 - 50, the modulus of the aqueous sodium silicate solution is 2.0 - 3.0, and the viscosity of Component A is 100 - 300 mPa·s.

3. The preparation method of the grouting reinforcement material according to claim 1, characterized in that, Component B includes, by mass, 30 - 80 parts of isocyanate prepolymer, 0 - 30 parts of isocyanate polymer, 18 - 26 parts of plasticizer, 5 - 15 parts of diluent. The viscosity of Component B is 90 - 300 mPa·s.

4. The preparation method of the grouting reinforcement material according to claim 1, characterized in that, In Step 2, the polyether polyol includes at least one of polyether polyol 3Y - 208, 3Y - 28 - 00, and 3Y - 28 - 82.

5. The preparation method of the grouting reinforcement material according to claim 1, wherein, In Step 1, the chain extender crosslinking agent includes glycerol.

6. The preparation method of the grouting reinforcement material according to claim 1, wherein, The composite catalyst is composed of CUCAT - WNT05A and DMP - 30 in combination.

7. The preparation method of the grouting reinforcement material according to claim 1, characterized in that, The diluent includes at least one of propylene carbonate, propylene glycol methyl ether acetate, diethylene glycol ethyl ether acetate, ethylene glycol diacetate, N,N - dimethylformamide, and glycol ether ester. The plasticizer includes at least one of dibutyl phthalate, diethylene glycol ethyl ether acetate, dioctyl phthalate, dioctyl adipate, didecyl adipate, and dioctyl terephthalate.

8. The preparation method of the grouting reinforcement material according to claim 1, characterized in that, The catalyst added in Step 3 is DMP - 30, and the mass of DMP - 30 is 0.05% of the mass of the added polymethylene polyphenyl polyisocyanate.

9. A grouting reinforcement material prepared by the method according to any one of claims 1 to 8.

10. The application of the grouting reinforcement material prepared by the method according to any one of claims 1 to 8 or the grouting reinforcement material in claim 9 in frozen soil subgrade, water - rich dam tunnels, and coal mine reinforcement projects.

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