Polymer for shrinkage reducing agent, shrinkage reducing agent, grouting material for collapsible loess treatment and grouting slurry

Abstract

The present invention provides a polymer for shrinkage reducing agent, a shrinkage reducing agent, a grouting material for treating collapsible loess, and a grouting slurry. Acetic anhydride, 4-vinylphenol, and 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid are mixed to carry out a first reaction to obtain a first intermediate; maleic anhydride, dipropylene glycol monomethyl ether, a first initiator, and hydroquinone are mixed to carry out a second reaction to obtain a second intermediate; the first intermediate, the second intermediate, and a second initiator are mixed to carry out a third reaction, and after pH adjustment, a polymer for shrinkage reducing agent is obtained. The polymer for shrinkage reducing agent and sodium aminated bentonite are subjected to an adsorption self-assembly reaction to obtain a shrinkage reducing agent. The grouting material includes component A containing cement, polycarboxylate water reducing agent, and shrinkage reducing agent, and component B containing sodium metaaluminate and water glass, which are stored separately. The grouting slurry is formed by mixing slurry A containing water and component A in the grouting material and slurry B containing water and component B in the grouting material.

Description

Technical Field

[0001] The present invention belongs to the technical field of collapsible loess treatment, and particularly relates to a shrinkage reducing agent polymer for a collapsible loess treatment composite grouting material, a shrinkage reducing agent for a collapsible loess treatment composite grouting material, a grouting material for collapsible loess treatment, and a grouting slurry for collapsible loess treatment and a preparation method thereof. Background Art

[0002] Collapsible loess is widely distributed, with a large coverage area and complex geological conditions. This special soil has the characteristic that after being soaked by water, the soil structure is rapidly damaged and significant additional settlement occurs, which brings many difficult problems to various engineering constructions. In many engineering practices, for example, in the foundation construction of building projects, when traditional foundation treatment methods are adopted without fully considering the characteristics of collapsible loess, once the building encounters rainwater infiltration or groundwater level changes after completion, the foundation soil will undergo collapsibility. This will lead to uneven settlement of the building, serious safety accidents such as wall cracking, tilting and even collapse, causing huge losses to people's lives and property. In the field of road engineering, if collapsible loess sections are not properly treated, under the action of rainwater scouring or groundwater, the roadbed will sink and deform, resulting in potholes and cracks on the road surface, seriously affecting the flatness and driving comfort of the road, increasing the risk of traffic accidents, and at the same time greatly increasing the road maintenance cost.

[0003] At present, ordinary cement-based grouting materials are often used for the treatment of collapsible loess. When the grouting slurry prepared from ordinary cement-based grouting materials hardens, a large amount of water is consumed and evaporated due to the cement hydration reaction. Microscopically, with this process, the water in the capillary pores of the material decreases, and the surface tension of the pore fluid increases to generate strong capillary pressure, which acts on the microstructure to form extrusion stress. Once the tensile strength is exceeded, a large number of pores and cracks are generated. The groundwater level in collapsible loess areas is variable and the soil is loose and porous. These cracks and pores become channels for water, harmful gases and erosive ions. The intrusion of water will exacerbate the deterioration of the material and reduce the strength. When the loess collapses, the cracks cannot effectively restrain the displacement of soil particles, and it is difficult to achieve the expected reinforcement effect. The interfacial adhesion between traditional grouting materials and collapsible loess particles is weak because the chemical composition and physical structure of the loess particle surface are complex, with a variety of minerals, active groups and irregular microtopographies, making it difficult to form stable chemical bonding and physical adsorption. When the actual project is loaded or the stress of loess collapse is transmitted, the connecting interface is easily separated and damaged, affecting the stability, safety and durability of the engineering structure. The rheological properties of the grouting slurry prepared from traditional grouting materials result in poor fluidity and permeability. During grouting, it is difficult to penetrate into the tiny pores and fracture networks of collapsible loess, causing local weak areas and unable to comprehensively and evenly penetrate and reinforce. These areas are prone to become the starting points of structural damage under the action of internal and external factors for a long time, leading to potential safety hazards and durability problems. Therefore, in view of the characteristics of collapsible loess and the limitations of traditional materials, it is extremely urgent and important to develop composite grouting materials, which is of great significance for improving the quality and safety of engineering construction in collapsible loess areas.

[0004] In summary, there is still a need to study new grouting materials suitable for the treatment of collapsible loess to improve the reinforcement effect on collapsible loess and enhance the stability, durability and safety of engineering structures in the collapsible loess environment. Summary of the Invention

[0005] The purpose of the present invention is to provide a technical solution for grouting materials suitable for the treatment of collapsible loess to improve the reinforcement effect on collapsible loess and enhance the stability, durability and safety of engineering structures in the collapsible loess environment.

[0006] To achieve the above purpose, the present invention provides the following technical solutions.

[0007] In the first aspect, the present invention provides a preparation method of a polymer for a shrinkage reducing agent, wherein the preparation method includes:

[0008] Mix acetic anhydride, 4-vinylphenol, and 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid, and carry out a first reaction at 100-150 °C; collect the organic phase in the product after the first reaction and dry it to obtain a first intermediate;

[0009] Maleic anhydride and dipropylene glycol monomethyl ether are mixed, and then a first initiator and hydroquinone are added, and a second reaction is carried out at 100-120 °C; the organic phase in the product after the second reaction is collected and dried to obtain a second intermediate;

[0010] The first intermediate and the second intermediate are mixed, and then a second initiator is added, and a third reaction is carried out at 85-100 °C; the pH value of the product after the third reaction is adjusted to 6.5-7.5 to obtain a polymer for shrinkage reducing agent.

[0011] The polymer for shrinkage reducing agent prepared by the preparation method of the polymer for shrinkage reducing agent of the present invention is a polymer for shrinkage reducing agent of a composite grouting material for treating collapsible loess. This polymer for shrinkage reducing agent can adsorb and self-assemble with amino-functionalized sodium-based bentonite to obtain a shrinkage reducing agent for a composite grouting material for treating collapsible loess.

[0012] According to a preferred embodiment of the first aspect, preferably, the first initiator comprises one or a combination of two or more of p-toluenesulfonic acid, titanium acetylacetonate, and trifluoromethanesulfonic anhydride.

[0013] According to a preferred embodiment of the first aspect, preferably, the second initiator comprises one or a combination of two or more of sodium persulfate, ammonium persulfate, and potassium persulfate.

[0014] According to a preferred embodiment of the first aspect, preferably, the pH regulator used to adjust the pH value of the product after the third reaction is sodium hydroxide;

[0015] In a specific embodiment, sodium hydroxide is added in the form of a sodium hydroxide solution. Based on the total mass of the sodium hydroxide solution being 100%, the mass content of sodium hydroxide in the sodium hydroxide solution is 10-20%.

[0016] According to a preferred embodiment of the first aspect, preferably, the mass ratio of acetic anhydride, 4-vinylphenol, and 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid is 1:10-30:30-60.

[0017] According to a preferred embodiment of the first aspect, preferably, the mass ratio of maleic anhydride, dipropylene glycol monomethyl ether, and hydroquinone is 1:2-5:0.01-0.03:0.005-0.01.

[0018] According to a preferred embodiment of the first aspect, preferably, the mass ratio of the first initiator to maleic anhydride is 0.01-0.03:1.

[0019] According to a preferred embodiment of the first aspect, preferably, the mass ratio of the first intermediate to the second intermediate is 1:1-2.

[0020] According to a preferred embodiment of the first aspect, preferably, the mass ratio of the second initiator to the first intermediate is 0.001-0.004:1.

[0021] According to a preferred embodiment of the first aspect, preferably, the addition of the second initiator is achieved by adding a second initiator solution; based on the total mass of the second initiator solution being 100%, the mass content of the second initiator in the second initiator solution is 5-10%;

[0022] More preferably, the mass ratio of the second initiator solution to the first intermediate is 0.02-0.04:1;

[0023] More preferably, the second initiator solution is added dropwise, and the dropping rate is 0.1-0.3 mL / s.

[0024] According to a preferred embodiment of the first aspect, preferably, the time of the first reaction is 5-8 h.

[0025] According to a preferred embodiment of the first aspect, preferably, the time of the second reaction is 5-8 h.

[0026] According to a preferred embodiment of the first aspect, preferably, the time of the third reaction is 3-5 h.

[0027] According to a preferred embodiment of the first aspect, preferably, the mixing of acetic anhydride, 4-vinylphenol, and 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid includes:

[0028] Adding acetic anhydride to 4-vinylphenol and mixing evenly, and then adding 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid and mixing evenly.

[0029] According to a preferred embodiment of the first aspect, preferably, collecting the organic phase in the product after the first reaction includes:

[0030] Adding water (such as deionized water) to the product after the first reaction for liquid separation, and then separating and collecting the organic phase generated by the liquid separation.

[0031] According to a preferred embodiment of the first aspect, preferably, collecting the organic phase in the product after the second reaction includes:

[0032] Adding water (such as deionized water) to the product after the second reaction for liquid separation, and then separating and collecting the organic phase generated by the liquid separation.

[0033] According to a preferred embodiment of the first aspect, preferably, adjusting the pH value of the product after the third reaction is carried out after the product after the third reaction is cooled to room temperature (25-30 °C).

[0034] In a second aspect, the present invention provides a polymer for a shrinkage reducing agent, wherein the polymer for a shrinkage reducing agent can be prepared by the method for preparing a polymer for a shrinkage reducing agent provided in the first aspect of the present invention.

[0035] In a third aspect, the present invention provides a method for preparing a shrinkage reducing agent, wherein the preparation method includes:

[0036] Mixing an aqueous solution of the polymer for a shrinkage reducing agent provided in the second aspect of the present invention with an aqueous suspension of sodium aminated bentonite for a fourth reaction; centrifuging the product after the fourth reaction to separate out the precipitate; and drying the obtained precipitate to obtain the shrinkage reducing agent.

[0037] The shrinkage reducing agent prepared by the method for preparing a shrinkage reducing agent of the present invention is a shrinkage reducing agent for a composite grouting material for treating collapsible loess. In the preparation method of this shrinkage reducing agent, the fourth reaction is an adsorption self-assembly reaction of the polymer for a shrinkage reducing agent and sodium aminated bentonite.

[0038] According to a preferred embodiment of the third aspect, preferably, based on the total mass of the aqueous solution of the polymer for a shrinkage reducing agent being 100%, the mass content of the polymer for a shrinkage reducing agent in the aqueous solution of the polymer for a shrinkage reducing agent is 10-15%.

[0039] According to a preferred embodiment of the third aspect, preferably, the mass ratio of sodium aminated bentonite to water in the aqueous suspension of sodium aminated bentonite is 1:5-10.

[0040] According to a preferred embodiment of the third aspect, preferably, the mass ratio of sodium aminated bentonite in the aqueous suspension of sodium aminated bentonite to the polymer for a shrinkage reducing agent in the aqueous solution of the polymer for a shrinkage reducing agent is 1:0.2-0.6.

[0041] According to a preferred embodiment of the third aspect, preferably, the fourth reaction is carried out at room temperature (25-30°C).

[0042] According to a preferred embodiment of the third aspect, preferably, the sodium aminated bentonite is prepared by the following method:

[0043] Mixing sodium-based bentonite, aminopropyltriethoxysilane, and toluene, carrying out a fifth reaction at 100-120°C (for example, 110°C), centrifuging the product obtained from the fifth reaction, and then drying to obtain the sodium aminated bentonite;

[0044] More preferably, the fifth reaction is carried out under heating reflux conditions;

[0045] More preferably, the time of the fifth reaction is 6-12 h;

[0046] More preferably, the product obtained from the fifth reaction is ultrasonically cleaned with anhydrous ethanol and deionized water before centrifugation;

[0047] In a specific embodiment, the drying is carried out at 70 - 90 °C (for example, 80 °C) for 24 - 36 h.

[0048] According to a preferred embodiment of the third aspect, preferably, the aqueous suspension of sodium aminated bentonite is prepared by the following method:

[0049] Disperse the sodium aminated bentonite in deionized water and stir vigorously at room temperature (25 - 30 °C) for 2 - 5 h to obtain an aqueous suspension of sodium aminated bentonite.

[0050] In a fourth aspect, the present invention provides a shrinkage reducing agent, wherein the shrinkage reducing agent can be prepared by the preparation method of the shrinkage reducing agent provided in the third aspect of the present invention.

[0051] In a fifth aspect, the present invention provides a grouting material for treating collapsible loess, wherein the grouting material includes component A and component B stored separately;

[0052] Component A contains the following components: cement, polycarboxylate superplasticizer and the shrinkage reducing agent provided in the fourth aspect of the present invention in a mass ratio of 30 - 50:1 - 3:2 - 5;

[0053] Component B contains the following components: sodium metaaluminate and water glass in a mass ratio of 10 - 20:20 - 30.

[0054] According to a preferred embodiment of the fifth aspect, preferably, the cement includes at least one of portland cement, aluminate cement, and sulfoaluminate cement.

[0055] According to a preferred embodiment of the fifth aspect, preferably, the superplasticizer includes at least one of polycarboxylate superplasticizer, lignosulfonate superplasticizer, melamine superplasticizer, and naphthalene superplasticizer.

[0056] According to a preferred embodiment of the fifth aspect, preferably, the mass ratio of component A to component B is 1:1 - 3.

[0057] In a sixth aspect, the present invention provides a grouting slurry for treating collapsible loess, wherein the grouting slurry is formed by mixing slurry A and slurry B in a volume ratio of 1:1 - 1:2;

[0058] The A slurry contains water and the A component in the grouting material for collapsible loess treatment provided in the fifth aspect of the present invention, where the mass ratio of water to cement in the A component is 40-60:30-50; that is, the A slurry contains the following components: cement, water, polycarboxylate water reducer, and shrinkage reducing agent provided in the fourth aspect of the present invention, with a mass ratio of 30-50:40-60:1-3:2-5;

[0059] The B slurry contains water and the B component in the grouting material for collapsible loess treatment provided in the fifth aspect of the present invention, where the mass ratio of water to sodium metaaluminate in the B component is 60-80:10-20; that is, the B slurry contains the following components: water, sodium metaaluminate, and sodium silicate, with a mass ratio of 60-80:10-20:20-30.

[0060] In the seventh aspect, the present invention provides a preparation method of the grouting slurry for collapsible loess treatment provided in the sixth aspect of the present invention, where the preparation method includes:

[0061] Mix cement, water, polycarboxylate water reducer, and shrinkage reducing agent proportionally to obtain the A slurry;

[0062] Mix water, sodium metaaluminate, and sodium silicate proportionally to obtain the B slurry;

[0063] Mix the A slurry and the B slurry proportionally to obtain the grouting slurry for collapsible loess treatment.

[0064] According to the preferred embodiment of the seventh aspect, preferably, mixing cement, water, polycarboxylate water reducer, and shrinkage reducing agent proportionally to obtain the A slurry includes:

[0065] Mix cement, water, polycarboxylate water reducer, and shrinkage reducing agent proportionally in a mixer and stir and mix them evenly. The stirring speed is 300-500 r / min, and the stirring time is 10-20 min to obtain the A slurry.

[0066] According to the preferred embodiment of the seventh aspect, preferably, mixing water, sodium metaaluminate, and sodium silicate proportionally to obtain the B slurry includes:

[0067] Mix water, sodium metaaluminate, and sodium silicate proportionally in another mixer and stir and mix them evenly. The stirring speed is 200-400 r / min, and the stirring time is 15-25 min to obtain the B component slurry.

[0068] According to the preferred embodiment of the seventh aspect, preferably, mixing the A slurry and the B slurry proportionally to obtain the grouting slurry for collapsible loess treatment includes:

[0069] Mix the A slurry and the B slurry evenly in proportion and continuously stir during the mixing process. The stirring speed is 100 - 300 r / min, and the stirring time is 5 - 10 min to obtain the grouting slurry for treating collapsible loess.

[0070] According to the preferred embodiment of the seventh aspect, preferably, the ambient temperature during the preparation of the A slurry, the preparation of the B slurry, and the mixing process of the A slurry and the B slurry is controlled at 25 - 30 °C, and the humidity is controlled at 50% - 60%.

[0071] The technical solution of the present invention helps to improve the reinforcement effect on collapsible loess and enhance the stability, durability, and safety of the engineering structure in the collapsible loess environment. Compared with the prior art, the technical solution provided by the present invention has the following beneficial effects:

[0072] (1) The grouting slurry prepared with the grouting material provided by the present invention can effectively overcome the problems of water consumption and evaporation caused by the cement hydration reaction in the treatment of collapsible loess with traditional cement-based grouting slurries, reduce the cracks and pores generated by the reduction of capillary water and the increase of surface tension of pore fluid in the material, and avoid the material deterioration caused by the intrusion of water, harmful gases, and erosive ions. The grouting material provided by the present invention enhances the interfacial adhesion between the grouting material and the collapsible loess particles through a shrinkage reducing agent, effectively restrains the displacement of soil particles, improves the reinforcement effect, and at the same time improves the poor rheological properties of the grouting slurry prepared with traditional grouting materials, increases the fluidity and permeability, and can comprehensively, evenly, and deeply reinforce the micro-pores and fracture networks of collapsible loess, significantly enhancing the stability, durability, and safety of the engineering structure in the collapsible loess environment, and reducing various safety hazards and durability problems caused by collapsible loess.

[0073] (2) The polymer used as the shrinkage reducing agent provided by the present invention is negatively charged in solution and can self-assemble with the charged surface of sodium aminated bentonite to form the shrinkage reducing agent provided by the present invention. The comb-like structure can form a three-dimensional network structure, effectively resist the action of external forces, and prevent problems such as deformation and cracking of the material during use, especially suitable for the soil environment of collapsible loess that is prone to deformation when encountering water or stress. The carboxyl group can chemically react with minerals such as aluminosilicates commonly present in collapsible loess to form stable chemical bonds, making the connection between the grouting material and the soil particles more firm. At the same time, the carboxyl group can also physically adsorb with the active groups on the surface of the soil particles, greatly enhancing the bonding performance, making the soil structure after grouting more stable and reducing the relative displacement of soil particles. The shrinkage reducing agent provided by the present invention is formed by the adsorption and self-assembly of a special polymer with a comb-like structure provided by the present invention and sodium aminated bentonite.

[0074] (3) The main chain of the polymer for shrinkage reducing agent provided by the present invention has a polyoxyethylene structure, which has good flexibility and water solubility. The shrinkage reducing agent formed by its adsorption and self-assembly with sodium aminated bentonite can play a role of plasticization and lubrication in the grouting material, reduce the viscosity of the material, thereby improving its fluidity and making it easier to inject into the tiny pores and fissures of collapsible loess, effectively reducing the pores and cracks in the concrete grouting material, making the microstructure of the material more dense, achieving deep reinforcement. The polyoxyethylene structure can form hydrogen bonds with water molecules to prevent the intrusion of water molecules, thereby improving the water resistance of the grouting material, hindering the intrusion of moisture, harmful gases and ions, improving the impermeability of concrete, reducing the risk of erosion of the concrete structure, and enhancing its durability in harsh environments.

[0075] (4) The polymer for shrinkage reducing agent provided by the present invention has a tetraaza cyclic structure, and this tetraaza cyclic structure can form stable complexes with metal ions, etc. The shrinkage reducing agent formed by its adsorption and self-assembly with sodium aminated bentonite can further reduce the ion concentration in the pore fluid of the grouting material by virtue of the complexing action of the tetraaza cyclic structure, thereby more effectively reducing the surface tension of the pore water, enhancing the inhibitory ability of the shrinkage reducing agent on the drying shrinkage and autogenous shrinkage of the concrete grouting material, reducing the volume shrinkage caused by water evaporation and cement hydration, and reducing the risk of crack generation. Description of the Drawings

[0076] Figure 1 The compressive strength test result diagram of the grouting slurry for treating collapsible loess provided for each example and comparative example.

[0077] Figure 2 The surface tension and viscosity test result diagram provided for each example and comparative example.

[0078] Figure 3 The drying shrinkage test result diagram of the grouting slurry for treating collapsible loess provided for each example and comparative example.

[0079] Figure 4 The impermeability pressure test result diagram of the grouting slurry for treating collapsible loess provided for each example and comparative example. Detailed Embodiments

[0080] To make the objectives, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0081] Example 1

[0082] This embodiment provides a polymer for a shrinkage reducing agent, a shrinkage reducing agent, a grouting material for treating collapsible loess, and a grouting slurry for treating collapsible loess.

[0083] The polymer for the shrinkage reducing agent is prepared by the following method:

[0084] Ingredients are prepared according to the mass ratio of acetic anhydride, 4-vinylphenol, and 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid of 1:30:60. Add acetic anhydride to 4-vinylphenol, stir evenly, then add 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid, react at 150 °C for 8 h, then add deionized water for liquid separation, and collect the organic phase obtained after liquid separation for drying to obtain the first intermediate;

[0085] Ingredients are prepared according to the mass ratio of maleic anhydride, dipropylene glycol monomethyl ether, p-toluenesulfonic acid, and hydroquinone of 1:5:0.03:0.01. Mix maleic anhydride and dipropylene glycol monomethyl ether, then add p-toluenesulfonic acid and hydroquinone, and then react at 120 °C for 5 h. Perform liquid separation with deionized water, and collect the organic phase obtained after liquid separation and dry it to obtain the second intermediate;

[0086] Ingredients are prepared according to the mass ratio of the first intermediate, the second intermediate, and a sodium persulfate solution (the mass content of sodium persulfate in the sodium persulfate solution is 10%) of 1:2:0.04. After mixing the first intermediate and the second intermediate, slowly dropwise add the sodium persulfate solution (the dropping rate is 0.1 - 0.3 mL / s), react at 100 °C for 5 h, then cool to room temperature, and adjust the pH to 7 with a sodium hydroxide solution (the mass content of sodium hydroxide in the sodium hydroxide solution is 10%) to obtain the polymer for the shrinkage reducing agent.

[0087] The shrinkage reducing agent is prepared by the following method:

[0088] Ingredients are prepared according to the mass ratio of sodium-based bentonite, aminopropyltriethoxysilane, and toluene of 1:1.5:40. Add sodium-based bentonite and aminopropyltriethoxysilane to toluene, heat and reflux at 110 °C for 12 h. Ultrasonically clean the obtained suspension with absolute ethanol and deionized water, then centrifuge to separate the precipitate, and dry the separated precipitate at 80 °C for 24 h to obtain amino-functionalized sodium-based bentonite;

[0089] Ingredients are prepared according to the mass ratio of amino-functionalized sodium-based bentonite to deionized water of 1:10. Disperse the amino-functionalized sodium-based bentonite in deionized water and vigorously stir at room temperature for 5 h to obtain an aqueous suspension of amino-functionalized sodium-based bentonite;

[0090] Disperse the polymer for shrinkage reducing agent provided in this embodiment in deionized water, and stir evenly at room temperature to obtain an aqueous solution of the polymer for shrinkage reducing agent with a mass fraction of 15% of the polymer for shrinkage reducing agent.

[0091] Slowly drop the aqueous solution of the polymer for shrinkage reducing agent (the dropping speed is 0.1 - 0.3 mL / s) into the aqueous suspension of sodium aminated bentonite (the mass ratio of sodium aminated bentonite to the aqueous solution of the polymer for shrinkage reducing agent in the aqueous suspension of sodium aminated bentonite is 1:4), and an adsorption self-assembly reaction occurs. Then, centrifuge the obtained suspension to separate the precipitate, and dry the separated precipitate at 80 °C for 24 h to obtain the shrinkage reducing agent.

[0092] The grouting material for treating collapsible loess includes component A and component B separately stored with a volume ratio of 1:1.

[0093] Among them, component A is composed of portland cement, polycarboxylate water reducer (purchased from Wuhan Runxingyuan Technology Co., Ltd.) and the shrinkage reducing agent provided in this embodiment with a mass ratio of 50:3:5.

[0094] Among them, component B is composed of sodium metaaluminate and water glass with a mass ratio of 20:30.

[0095] The grouting slurry for treating collapsible loess is prepared by the following method:

[0096] Fully stir and mix component A of the grouting material for treating collapsible loess provided in this embodiment and water in a mixer at a stirring speed of 500 r / min for 20 min to obtain slurry A; among them, the mass ratio of cement, water, polycarboxylate water reducer and the shrinkage reducing agent provided in this embodiment is 50:60:3:5.

[0097] Fully stir and mix component B of the grouting material for treating collapsible loess provided in this embodiment and water in another mixer at a stirring speed of 400 r / min for 25 min to obtain slurry B; among them, the mass ratio of water, sodium metaaluminate and water glass is 80:20:30.

[0098] Mix slurry A and slurry B evenly at a volume ratio of 1:1 before grouting, and continuously stir during the mixing process at a stirring speed of 300 r / min for 10 min to obtain the grouting slurry for treating collapsible loess.

[0099] Among them, the environmental temperature is controlled at 30 °C and the humidity is controlled at 60% during the preparation process.

[0100] Example 2

[0101] This embodiment provides a polymer for shrinkage reducing agent, a shrinkage reducing agent, a grouting material for treating collapsible loess, and a grouting slurry for treating collapsible loess.

[0102] The polymer for shrinkage reducing agent is prepared by the following method:

[0103] Weigh acetic anhydride, 4-vinylphenol, and 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid according to the mass ratio of 1:10:30. Add acetic anhydride to 4-vinylphenol, stir evenly, then add 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid, react at 100 °C for 5 h, then add deionized water for liquid separation, and collect the organic phase obtained after liquid separation for drying to obtain the first intermediate;

[0104] Weigh maleic anhydride, dipropylene glycol monomethyl ether, p-toluenesulfonic acid, and hydroquinone according to the mass ratio of 1:2:0.01:0.005. Mix maleic anhydride and dipropylene glycol monomethyl ether, then add p-toluenesulfonic acid and hydroquinone, and then react at 100 °C for 5 h. Perform liquid separation with deionized water, and collect the organic phase obtained after liquid separation for drying to obtain the second intermediate;

[0105] Weigh the first intermediate, the second intermediate, and a sodium persulfate solution (the mass content of sodium persulfate in the sodium persulfate solution is 5%) according to the mass ratio of 1:1:0.02. After mixing the first intermediate and the second intermediate, slowly add dropwise (the dropping rate is 0.1 - 0.3 mL / s) the sodium persulfate solution, react at 85 °C for 3 h, then cool to room temperature, and adjust the pH to 7 with a sodium hydroxide solution (the mass content of sodium hydroxide in the sodium hydroxide solution is 10%) to obtain the polymer for shrinkage reducing agent.

[0106] The shrinkage reducing agent is prepared by the following method:

[0107] Weigh sodium bentonite, aminopropyltriethoxysilane, and toluene according to the mass ratio of 1:0.5:20. Add sodium bentonite and aminopropyltriethoxysilane to toluene, heat and reflux at 110 °C for 6 h. Ultrasonically clean the obtained suspension with absolute ethanol and deionized water, then centrifuge to separate the precipitate, and dry the separated precipitate at 80 °C for 24 h to obtain amino-functionalized sodium bentonite;

[0108] Weigh amino-functionalized sodium bentonite and deionized water according to the mass ratio of 1:5. Disperse amino-functionalized sodium bentonite in deionized water, and vigorously stir at room temperature for 2 h to obtain an aqueous suspension of amino-functionalized sodium bentonite;

[0109] Disperse the polymer for shrinkage reducing agent provided in this example in deionized water, and stir evenly at room temperature to obtain an aqueous solution of the polymer for shrinkage reducing agent with a mass fraction of 10% of the polymer for shrinkage reducing agent;

[0110] Slowly drip the aqueous solution of the polymer for shrinkage reducing agent (dripping speed is 0.1 - 0.3 mL / s) into the aqueous suspension of sodium aminated bentonite (the mass ratio of sodium aminated bentonite to the aqueous solution of the polymer for shrinkage reducing agent in the aqueous suspension of sodium aminated bentonite is 1:2), an adsorption self-assembly reaction occurs, then centrifuge the resulting suspension to separate the precipitate, and dry the separated precipitate at 80 °C for 24 h to obtain the shrinkage reducing agent.

[0111] The grouting material for treating collapsible loess includes component A and component B stored separately with a volume ratio of 1:2;

[0112] Among them, component A is composed of aluminate cement, polycarboxylate water reducer (purchased from Wuhan Runxingyuan Technology Co., Ltd.) and the shrinkage reducing agent provided in this example with a mass ratio of 30:1:2;

[0113] Among them, component B is composed of sodium metaaluminate and water glass with a mass ratio of 10:20.

[0114] The grouting slurry for treating collapsible loess is prepared by the following method:

[0115] Fully stir and mix component A of the grouting material for treating collapsible loess provided in this example and water in a mixer at a stirring speed of 300 r / min for 10 min to obtain slurry A; among them, the mass ratio of cement, water, polycarboxylate water reducer and the shrinkage reducing agent provided in this example is 30:40:1:2;

[0116] Fully stir and mix component B of the grouting material for treating collapsible loess provided in this example and water in another mixer at a stirring speed of 200 r / min for 15 min to obtain slurry B; among them, the mass ratio of water, sodium metaaluminate and water glass is 60:10:20;

[0117] Mix slurry A and slurry B evenly at a volume ratio of 1:2 before grouting, and continuously stir during the mixing process at a stirring speed of 100 r / min for 5 min to obtain the grouting slurry for treating collapsible loess;

[0118] Among them, the environmental temperature is controlled at 25 °C and the humidity is controlled at 50% during the preparation process.

[0119] Example 3

[0120] This embodiment provides a polymer for shrinkage reducing agent, a shrinkage reducing agent, a grouting material for treating collapsible loess, and a grouting slurry for treating collapsible loess.

[0121] The polymer for shrinkage reducing agent is prepared by the following method:

[0122] Weigh materials according to the mass ratio of acetic anhydride, 4-vinylphenol, and 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid of 1:20:45. Add acetic anhydride to 4-vinylphenol, stir evenly, then add 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid, react at 125 °C for 6.5 h, then add deionized water for liquid separation, collect the organic phase obtained after liquid separation and dry it to obtain the first intermediate;

[0123] Weigh materials according to the mass ratio of maleic anhydride, dipropylene glycol monomethyl ether, p-toluenesulfonic acid, and hydroquinone of 1:3.5:0.02:0.0075. Mix maleic anhydride and dipropylene glycol monomethyl ether, then add p-toluenesulfonic acid and hydroquinone, and then react at 110 °C for 5 h. Perform liquid separation with deionized water, collect the organic phase obtained after liquid separation and dry it to obtain the second intermediate;

[0124] Weigh materials according to the mass ratio of the first intermediate, the second intermediate, and a sodium persulfate solution (the mass content of sodium persulfate in the sodium persulfate solution is 7.5%) of 1:1.5:0.03. After mixing the first intermediate and the second intermediate, slowly dropwise add (the dropping rate is 0.1 - 0.3 mL / s) the sodium persulfate solution, react at 92.5 °C for 4 h, then cool to room temperature, and adjust the pH to 7 with a sodium hydroxide solution (the mass content of sodium hydroxide in the sodium hydroxide solution is 10%) to obtain the polymer for shrinkage reducing agent.

[0125] The shrinkage reducing agent is prepared by the following method:

[0126] Weigh materials according to the mass ratio of sodium-based bentonite, aminopropyltriethoxysilane, and toluene of 1:1:30. Add sodium-based bentonite and aminopropyltriethoxysilane to toluene, heat under reflux at 110 °C for 9 h. Ultrasonically clean the obtained suspension with absolute ethanol and deionized water, then centrifuge to separate out the precipitate, and dry the separated precipitate at 80 °C for 24 h to obtain amino-functionalized sodium-based bentonite;

[0127] Weigh materials according to the mass ratio of amino-functionalized sodium-based bentonite to deionized water of 1:7.5. Disperse the amino-functionalized sodium-based bentonite in deionized water and vigorously stir at room temperature for 3.5 h to obtain an aqueous suspension of amino-functionalized sodium-based bentonite;

[0128] Disperse the polymer for shrinkage reducing agent provided in this example in deionized water, and stir evenly at room temperature to obtain an aqueous solution of the polymer for shrinkage reducing agent with a mass fraction of 12.5% of the polymer for shrinkage reducing agent.

[0129] Slowly drop the aqueous solution of the polymer for shrinkage reducing agent (the dropping speed is 0.1 - 0.3 mL / s) into the aqueous suspension of sodium aminated bentonite (the mass ratio of sodium aminated bentonite to the aqueous solution of the polymer for shrinkage reducing agent in the aqueous suspension of sodium aminated bentonite is 1:3), and an adsorption self-assembly reaction occurs. Then, centrifuge the obtained suspension to separate the precipitate, and dry the separated precipitate at 80 °C for 24 h to obtain the shrinkage reducing agent.

[0130] The grouting material for treating collapsible loess includes component A and component B stored separately with a volume ratio of 1:2.

[0131] Among them, component A is composed of sulfoaluminate cement, polycarboxylate superplasticizer (purchased from Wuhan Runxingyuan Technology Co., Ltd.) and the shrinkage reducing agent provided in this example with a mass ratio of 40:2:3.5.

[0132] Among them, component B is composed of sodium metaaluminate and sodium silicate with a mass ratio of 15:25.

[0133] The grouting slurry for treating collapsible loess is prepared by the following method:

[0134] Fully stir and mix component A of the grouting material for treating collapsible loess provided in this example and water in a mixer at a stirring speed of 400 r / min for 15 min to obtain slurry A; among them, the mass ratio of cement, water, polycarboxylate superplasticizer and the shrinkage reducing agent provided in this example is 40:50:2:3.5.

[0135] Fully stir and mix component B of the grouting material for treating collapsible loess provided in this example and water in another mixer at a stirring speed of 300 r / min for 20 min to obtain slurry B; among them, the mass ratio of water, sodium metaaluminate and sodium silicate is 70:15:25.

[0136] Mix slurry A and slurry B evenly at a volume ratio of 1:1.5 before grouting, and continuously stir during the mixing process at a stirring speed of 200 r / min for 7.5 min to obtain the grouting slurry for treating collapsible loess.

[0137] Among them, the environmental temperature during the preparation process is controlled at 27.5 °C, and the humidity is controlled at 55%.

[0138] Comparative Example 1

[0139] This comparative example provides a grouting material for treating collapsible loess and a grouting slurry for treating collapsible loess.

[0140] The difference between the grouting material for treating collapsible loess provided in this comparative example and the grouting material for treating collapsible loess provided in Example 3 lies only in the type of shrinkage reducing agent. In this comparative example, a conventional alcohol-based shrinkage reducing agent, fatty alcohol polyoxyethylene ether methacrylate (purchased from Hangzhou Moore New Materials Co., Ltd.), is used as the shrinkage reducing agent.

[0141] Comparative Example 2

[0142] This comparative example provides a polymer for shrinkage reducing agent, a shrinkage reducing agent, a grouting material for treating collapsible loess, and a grouting slurry for treating collapsible loess.

[0143] The polymer for shrinkage reducing agent is prepared by the following method:

[0144] Ingredients are prepared according to the mass ratio of maleic anhydride, dipropylene glycol monomethyl ether, p-toluenesulfonic acid, and hydroquinone of 1:3.5:0.02:0.0075. After mixing maleic anhydride and dipropylene glycol monomethyl ether, p-toluenesulfonic acid and hydroquinone are added, and then the reaction is carried out at 110 °C for 5 h. Liquid separation is carried out with deionized water, and the organic phase obtained after liquid separation is collected and dried to obtain the second intermediate;

[0145] Ingredients are prepared according to the mass ratio of 4-vinylphenol, the second intermediate, and sodium persulfate solution (the mass content of sodium persulfate in the sodium persulfate solution is 7.5%) of 1:1.5:0.03. After mixing the first intermediate and the second intermediate, the sodium persulfate solution is slowly added dropwise (the dropping rate is 0.1 - 0.3 mL / s). After reacting at 92.5 °C for 4 h, it is cooled to room temperature, and the pH is adjusted to 7 with sodium hydroxide solution (the mass content of sodium hydroxide in the sodium hydroxide solution is 10%) to obtain the polymer for shrinkage reducing agent.

[0146] The difference between the polymer for shrinkage reducing agent provided in this comparative example and the polymer for shrinkage reducing agent provided in Example 3 is that 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid is not introduced into the side chain.

[0147] The shrinkage reducing agent is prepared by the following method:

[0148] Ingredients are prepared according to the mass ratio of sodium-based bentonite, aminopropyl ethoxysilane, and toluene of 1:1:30. Sodium-based bentonite and aminopropyl ethoxysilane are added to toluene, and heated under reflux at 110 °C for 9 h. The obtained suspension is ultrasonically cleaned with absolute ethanol and deionized water, and then the precipitate is separated by centrifugation. The separated precipitate is dried at 80 °C for 24 h to obtain amino-functionalized sodium-based bentonite;

[0149] Ingredients are prepared according to the mass ratio of amino-functionalized sodium-based bentonite to deionized water of 1:7.5. The amino-functionalized sodium-based bentonite is dispersed in deionized water and vigorously stirred at room temperature for 3.5 h to obtain an aqueous suspension of amino-functionalized sodium-based bentonite;

[0150] The shrinkage reducing agent provided in this comparative example is dispersed in deionized water with a polymer and stirred evenly at room temperature to obtain an aqueous solution of the polymer for shrinkage reducing agent with a mass fraction of 12.5% of the polymer for shrinkage reducing agent;

[0151] The aqueous solution of the polymer for shrinkage reducing agent is slowly added dropwise (the dropping speed is 0.1 - 0.3 mL / s) to the aqueous suspension of amino-functionalized sodium-based bentonite (the mass ratio of amino-functionalized sodium-based bentonite in the aqueous suspension of amino-functionalized sodium-based bentonite to the aqueous solution of the polymer for shrinkage reducing agent is 1:3), and an adsorption self-assembly reaction occurs. Then, the precipitate is centrifuged from the resulting suspension, and the separated precipitate is dried at 80 °C for 24 h to obtain the shrinkage reducing agent.

[0152] The grouting material for treating collapsible loess includes component A and component B stored separately;

[0153] Among them, component A is composed of cement, polycarboxylate water reducer, and the shrinkage reducing agent provided in this comparative example with a mass ratio of 40:2:3.5;

[0154] Among them, component B is composed of sodium metaaluminate and sodium silicate with a mass ratio of 15:25.

[0155] The grouting slurry for treating collapsible loess is prepared by the following method:

[0156] Component A of the grouting material for treating collapsible loess provided in this comparative example and water are fully stirred and mixed evenly in a mixer at a stirring speed of 400 r / min for 15 min to obtain slurry A; among them, the mass ratio of cement, water, polycarboxylate water reducer, and the shrinkage reducing agent provided in this example is 40:50:2:3.5;

[0157] Component B of the grouting material for treating collapsible loess provided in this comparative example and water are fully stirred and mixed evenly in another mixer at a stirring speed of 300 r / min for 20 min to obtain slurry B; among them, the mass ratio of water, sodium metaaluminate, and sodium silicate is 70:15:25;

[0158] Slurry A and slurry B are mixed evenly at a volume ratio of 1:1 before grouting, and continuous stirring is carried out during the mixing process at a stirring speed of 200 r / min for 7.5 min to obtain the grouting slurry for treating collapsible loess;

[0159] Among them, the environmental temperature is controlled at 27.5 °C and the humidity is controlled at 55% during the preparation process.

[0160] Test Example 1

[0161] Mechanical Property Analysis of Grouting Slurry for Treating Collapsible Loess

[0162] The grouting slurries for treating collapsible loess provided in each example and comparative example were cured in accordance with the curing method of ordinary cement mortar, and the compressive strength was tested at 7 days and 28 days according to the standard of GB / T 17671-2021. The results are shown in Figure 1 。

[0163] It can be seen from Figure 1 that the grouting slurries for treating collapsible loess provided in Examples 1-3 have higher early strength compressive strength and higher 28-day compressive strength compared with the grouting slurries for treating collapsible loess provided in Comparative Examples 1-2. Since the shrinkage reducing agent used in the grouting slurries for treating collapsible loess provided in Examples 1-3 is obtained by the adsorption self-assembly reaction of the polymer for shrinkage reducing agent and sodium aminated bentonite, the shrinkage reducing agent forms a three-dimensional network structure by means of the comb-like structure of the polymer for shrinkage reducing agent, effectively resisting external forces. In the grouting material, this structure can enhance the overall stability of the material, making it less likely to be damaged when stressed, thus improving the compressive strength. Moreover, the comb-like side chains in the shrinkage reducing agent are rich in carboxyl groups, and the carboxyl groups form stable chemical bonds with the minerals in the collapsible loess and produce physical adsorption with the surface active groups of the soil particles, making the soil structure after grouting more stable and reducing the relative displacement of the soil particles. This also indirectly enables the grouting material to better transmit and disperse stress when the overall structure is stressed, thereby improving the compressive strength, and the strength performance is more excellent both in the early stage and in the long term of 28 days.

[0164] Test Example 2

[0165] Analysis of the Effect of Shrinkage Reducing Agent

[0166] Ordinary Portland cement powder and deionized water were mixed evenly at a mass ratio of 1:10 and left standing for 24 h. After filtration, the supernatant was taken, which was the concrete pore solution. The pH value of this concrete pore solution was 12.8. The shrinkage reducing agents used in Examples 1-3 and Comparative Examples 1-2 were incorporated into the above-prepared concrete pore solution at an incorporation amount of 15 wt% respectively, and after mixing evenly, the surface tension and viscosity were measured. The results are shown in Figure 2 。

[0167] It can be seen from Figure 2It can be seen that after the shrinkage reducing agent used in Examples 1 - 3 was incorporated into the concrete pore solution at an incorporation amount of 15 wt%, the surface tension and viscosity exhibited were lower than those after the shrinkage reducing agent used in Comparative Example 1 - Example 2 was incorporated into the concrete pore solution at an incorporation amount of 15 wt%. Since the tetrazacyclic structure in the polymer used as the shrinkage reducing agent in the shrinkage reducing agent can form stable complexes with metal ions, etc., after grafting onto the polymer used as the shrinkage reducing agent in the shrinkage reducing agent, its complexing effect can further reduce the ion concentration in the pore fluid of the grouting material, thereby more effectively reducing the surface tension of the pore water. At the same time, the polyoxyethylene structure of the main chain of the polymer used as the shrinkage reducing agent in the shrinkage reducing agent has good flexibility and water solubility, and can play a plasticizing and lubricating role in the grouting slurry, reducing the viscosity of the material. Therefore, compared with the comparative example, the shrinkage reducing agent in the example shows the advantages of reducing surface tension and viscosity, making it more conducive to injection into small pores and other parts of collapsible loess in practical applications.

[0168] Test Example 3

[0169] Analysis of the anti - shrinkage performance of the grouting slurry for treating collapsible loess

[0170] The drying shrinkage of the grouting slurry for treating collapsible loess provided in each example and each comparative example was tested according to the standard of GB / T 17671 - 2021, and the results are shown in Figure 3 .

[0171] It can be seen from Figure 3 that the drying shrinkage of the grouting slurry for treating collapsible loess provided in the examples increased less with the increase of days. This is because the complexing effect of the tetrazacyclic structure of the polymer used as the shrinkage reducing agent in the shrinkage reducing agent can reduce the surface tension of the pore water, enhance the ability to inhibit the drying shrinkage and autogenous shrinkage of the concrete grouting material. At the same time, the polyoxyethylene structure can form hydrogen bonds with water molecules, prevent the intrusion of water molecules, and reduce the volume shrinkage caused by water evaporation and cement hydration. Therefore, in the test, the grouting slurry for treating collapsible loess provided in the examples showed better anti - shrinkage performance than the grouting slurry for treating collapsible loess provided in the comparative examples, and could better maintain the stability of its own structural dimensions during long - term use, and was more adaptable to the environmental characteristics of collapsible loess that is prone to deformation due to the influence of moisture.

[0172] Test Example 4

[0173] Analysis of the anti - permeability performance of the grouting slurry for treating collapsible loess

[0174] The anti - permeability pressure of the grouting slurry for treating collapsible loess provided in each example and each comparative example was tested according to the standard of GB / T 50082 - 2009, and the results are shown in Figure 4 .

[0175] It can be seen fromFigure 4 It can be seen that the grouting slurry for collapsible loess treatment provided by the embodiment has a higher anti-seepage pressure and good anti-seepage performance. Analyzing the reasons: The polyoxyethylene structure of the main chain of the polymer used as the shrinkage reducing agent in the shrinkage reducing agent can form hydrogen bonds with water molecules, hindering the intrusion of moisture, harmful gases and ions, and improving the anti-seepage performance of concrete. Coupled with its comb-like structure, it can make the microstructure of the grouting material denser, reducing the pores and cracks, which are the weak parts that may become the intrusion channels of external substances. Therefore, compared with the comparative example, the grouting slurry for collapsible loess treatment provided by the embodiment has better anti-seepage performance, can better resist the erosion of external factors such as moisture on the soil structure after grouting reinforcement, and ensure the durability and stability of the engineering structure in the collapsible loess environment.

[0176] The above-described embodiments are for better explaining the present invention. For those skilled in the art of technology research and development, it is not very difficult to make various modifications to these embodiments without departing from the principle and spirit of the present invention. Therefore, the present invention is not limited to the embodiments here, and all improvements and changes made to the present invention by those skilled in the art according to the principle and spirit of the present invention should be within the protection scope of the present invention.

Claims

1. A preparation method of a polymer for a shrinkage reducing agent, characterized in that, The preparation method includes: Mix acetic anhydride, 4-vinylphenol, and 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid, and conduct a first reaction at 100-150 °C; collect the organic phase in the product after the first reaction and dry it to obtain a first intermediate; Mix maleic anhydride and dipropylene glycol monomethyl ether, then add a first initiator and hydroquinone, and conduct a second reaction at 100-120 °C; collect the organic phase in the product after the second reaction and dry it to obtain a second intermediate; Mix the first intermediate and the second intermediate, then add a second initiator, and conduct a third reaction at 85-100 °C; adjust the pH value of the product after the third reaction to 6.5-7.5 to obtain a polymer for shrinkage reducing agent.

2. The preparation method according to claim 1, wherein The first initiator includes one or a combination of two or more of p-toluenesulfonic acid, titanium acetylacetonate, and trifluoromethanesulfonic anhydride; The second initiator includes one or a combination of two or more of sodium persulfate, ammonium persulfate, and potassium persulfate.

3. The preparation method according to claim 1 or 2, wherein The mass ratio of the first initiator to maleic anhydride is 0.01-0.03:1; The mass ratio of the second initiator to the first intermediate is 0.001-0.004:

1.

4. The preparation method according to claim 1, wherein The mass ratio of acetic anhydride, 4-vinylphenol, and 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid is 1:10-30:30-60; The mass ratio of maleic anhydride, dipropylene glycol monomethyl ether, and hydroquinone is 1:2-5:0.01-0.03:0.005-0.01; The mass ratio of the first intermediate to the second intermediate is 1:1-2.

5. A polymer for a shrinkage reducing agent, characterized in that, The polymer for shrinkage reducing agent is a polymer for shrinkage reducing agent prepared by the preparation method of the polymer for shrinkage reducing agent according to any one of claims 1-4.

6. A preparation method of a shrinkage reducing agent, characterized in that, The preparation method includes: Mix an aqueous solution of the polymer for shrinkage reducing agent according to claim 5 with an aqueous suspension of sodium aminated bentonite for a fourth reaction; centrifuge the product after the fourth reaction to separate out the precipitate; dry the obtained precipitate to obtain the shrinkage reducing agent.

7. The preparation method according to claim 6, wherein Based on the total mass of the aqueous solution of the polymer for shrinkage reducing agent being 100%, the mass content of the polymer for shrinkage reducing agent in the aqueous solution of the polymer for shrinkage reducing agent is 10-15%; In the aqueous suspension of sodium aminated bentonite, the mass ratio of sodium aminated bentonite to water is 1:5-10.

8. The preparation method according to claim 6, characterized in that, The mass ratio of sodium aminated bentonite to the polymer for shrinkage reducing agent is 1:0.2-0.

6.

9. The preparation method according to claim 6, characterized in that, The sodium aminated bentonite is prepared by the following method: Mix sodium bentonite, aminopropyltriethoxysilane, and toluene, conduct a fifth reaction at 100-120 °C, centrifuge the product obtained from the fifth reaction, and then dry it to obtain the sodium aminated bentonite.

10. A reducing agent, characterized in that, The shrinkage reducing agent is the shrinkage reducing agent prepared by the preparation method of the shrinkage reducing agent described in any one of claims 6-9.

11. A grouting material for treating collapsible loess, characterized in that, The grouting material includes component A and component B stored separately; Component A contains the following components: cement, polycarboxylate superplasticizer and the shrinkage reducing agent described in claim 10, with a mass ratio of 30-50:1-3:2-5; Component B contains the following components: sodium metaaluminate and water glass with a mass ratio of 10-20:20-30.

12. The grouting material according to claim 11, wherein, The cement includes at least one of Portland cement, aluminate cement, and sulfoaluminate cement.

13. The grouting material according to claim 11, characterized in that, The mass ratio of component A to component B is 1:1-3.

14. A grouting slurry for treating collapsible loess, characterized in that, The grouting slurry is formed by mixing slurry A and slurry B with a volume ratio of 1:1-1:2; Slurry A contains water and component A in the grouting material for treating collapsible loess described in any one of claims 11-13, wherein the mass ratio of water to the cement in component A is 40-60:30-50; Slurry B contains water and component B in the grouting material for treating collapsible loess described in any one of claims 11-13, wherein the mass ratio of water to the sodium metaaluminate in component B is 60-80:10-20.

15. The preparation method of the grouting slurry for collapsible loess treatment according to claim 14, characterized in that, The preparation method includes: Mixing cement, water, polycarboxylate superplasticizer, and shrinkage reducing agent in proportion to obtain slurry A; Mixing water, sodium metaaluminate, and water glass in proportion to obtain slurry B; Mixing slurry A and slurry B in proportion to obtain the grouting slurry for treating collapsible loess.

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