A high-fluidity grouting material and its preparation method

Abstract

The present invention belongs to the technical field of building materials, and particularly relates to a highly fluid grouting material and a preparation method thereof. The highly fluid grouting material is composed of the following raw materials in parts by weight: 49 - 59 parts of portland cement, 30 - 37 parts of ionic liquid aerogel composite, 10 - 13 parts of active filler, 0.5 part of defoamer, and 1 - 4 parts of hydroxypropyl methylcellulose. The ionic liquid aerogel composite loads choline propionate ionic liquid through a hydrophobic aerogel skeleton, releases a lubricating phase under the trigger of shear stress, and realizes self-leveling perfusion and vibration-free filling of microcracks. The bio-based cellulose network balances the flow and segregation resistance behaviors through dynamic hydrogen bonds. The grouting material provided by the present invention has the characteristics of low-viscosity penetration, environment-responsive curing, and low-carbon environmental protection, and is suitable for complex structure repair, underground engineering, and green building fields.

Description

Technical Field

[0001] The present invention belongs to the technical field of building materials, and particularly relates to a high-fluidity grouting material and a preparation method thereof. Background Art

[0002] As the core functional material of modern engineering structures, the rheological properties and reliability of grouting materials directly affect building safety and engineering life. The traditional technical system uses portland cement as the matrix, relying on chemical water reducers for adsorption and dispersion and the optimization of the grading of mineral admixtures to improve fluidity. However, due to the limitations of the intrinsic properties and action mechanisms of the materials, it has long faced three major technical contradictions: 1. It is difficult to balance the segregation and strength attenuation caused by excessive water reducers. Especially under low water-binder ratio conditions, the regulation of the thixotropy of the slurry has reached a bottleneck; 2. The composition ratio of the materials is restricted by the theory of the densest packing of particles. The interaction between micron-millimeter cross-scale particles is complex, and it is difficult to simultaneously achieve high fluidity and high density; 3. Although the modification of nanomaterials can improve the rheological properties, due to the interfacial energy effect and process compatibility limitations, the contradiction between dispersion stability and cost-effectiveness is prominent in industrial applications. These defects lead to problems such as fluidity loss, shear stratification, and insufficient environmental adaptability of traditional grouting materials in scenarios such as ultra-high-rise pumping and deep-sea structure sealing, seriously restricting the refined construction requirements of major projects.

[0003] In recent years, the global infrastructure construction has extended to extreme environments such as deep earth, deep sea, and polar regions, putting forward multi-dimensional collaborative requirements for the performance of grouting materials. However, due to the single lubrication mechanism and weak functional expansibility of the existing technical system, the engineering community is forced to adopt multi-material compounding or post-treatment processes, resulting in an extended construction period and a sharp increase in carbon emissions. Although emerging technologies such as self-healing and phase change temperature regulation provide directions for performance upgrading, their compatibility with traditional grouting systems and the reliability of the whole life cycle still need to be verified. Summary of the Invention

[0004] In view of the above situation, the present invention provides a high-fluidity grouting material and a preparation method thereof, constructing a composite system with portland cement as the matrix, ionic liquid-aerogel as the fluidity medium, and bio-based components as the dynamic regulation network. Utilizing the metal-like flow characteristics of ionic liquids and the pore orientation regulation ability of aerogels, the self-adaptive flow of the grouting material during the construction stage and the strength growth during the curing stage are realized, promoting the progress of engineering materials towards high fluidity, low carbonization, and functionality.

[0005] To achieve the above object, the technical solution adopted by the present invention is as follows:

[0006] The present invention provides a high-fluidity grouting material, and the grouting material comprises the following raw materials in parts by weight: 49-59 parts of portland cement, 30-37 parts of ionic liquid aerogel composite, 10-13 parts of active filler, 0.5 part of defoamer, and 1-4 parts of hydroxypropyl methylcellulose.

[0007] Furthermore, the active filler is composed of metakaolin and fly ash in a mass ratio of 1:1.

[0008] Furthermore, the defoaming agent is selected from any one of 0.5% (w / v) polyether modified silicone, emulsified silicone oil, and sodium lignosulfonate.

[0009] Furthermore, the ionic liquid aerogel composite includes the following raw materials: silica aerogel, choline hydroxide, propionic acid, activated carbon, and deionized water. The mass ratio of silica aerogel, choline hydroxide, propionic acid, activated carbon, and deionized water is 1:10 - 20:5 - 10:2:67 - 82. The preparation method of the ionic liquid aerogel composite includes the following steps:

[0010] S1: Weigh silica aerogel, choline hydroxide, propionic acid, activated carbon, and deionized water according to the mass ratio of 1:10 - 20:5 - 10:2:67 - 82. Dissolve the weighed choline hydroxide in deionized water to prepare a choline solution. Add propionic acid to the choline solution and place it in a reaction kettle. Stir magnetically at 4°C and 100 rpm for 4 h to obtain a crude product.

[0011] S2: Mix the activated carbon with the crude product, stir magnetically at 100 rpm for 2 h, filter to remove the activated carbon, collect the filtrate, and filter the filtrate through a 0.22 μm filter membrane to obtain an ionic liquid.

[0012] S3: Immerse the silica aerogel in absolute ethanol, ultrasonically clean it for 30 min, then vacuum dry it at 60°C for 12 h to obtain an activated aerogel. Place the activated aerogel in a closed reaction kettle, introduce HMDS (hexamethyldisilazane) vapor, maintain it at 120°C for 2 h, and take it out after cooling to room temperature to obtain a hydrophobic aerogel.

[0013] S4: Mix the hydrophobic aerogel with the ionic liquid and place it in a vacuum impregnation tank for 30 min to obtain an ionic liquid aerogel composite.

[0014] The present invention also provides a preparation method of a high-fluidity grouting material, which specifically includes the following steps:

[0015] Step 1: Weigh 30 - 37 parts of the ionic liquid aerogel composite, preheat it at 40°C for 30 min, then weigh 0.5 part of the defoaming agent and add it thereto, and perform high-speed shearing and pre-dispersion at 2000 rpm for 5 min to obtain a dispersion liquid.

[0016] Step 2: Weigh 49 - 59 parts of portland cement, dry it at 105 °C for 2 h, and pass it through an 80 - mesh sieve to obtain activated cement. Weigh 10 - 13 parts of active filler, calcine it in a muffle furnace at 500 °C for 1 h, then put it into a blender together with the activated cement, and mix at 500 rpm for 10 min to obtain a uniform dry powder system;

[0017] Step 3: Slowly add the dispersion liquid to the uniform dry powder system, continue to mix at 1000 rpm for 15 min, and measure the viscosity to be 200 - 300 mPa·s to obtain a wet - mixed material;

[0018] Step 4: Weigh 1 - 4 parts of hydroxypropyl methylcellulose, add it to the wet - mixed material and let it stand for 20 min, then shear it at 2000 rpm for 3 min, degas it with a vacuum degasser for 20 min, and circulate it through a three - roll mill 2 times to obtain the grouting material.

[0019] The beneficial effects obtained by the present invention are as follows:

[0020] A high - fluidity grouting material provided by the present invention, through the innovative integration of portland cement and ionic liquid aerogel composite medium, endows the grouting material with breakthrough self - driving flow performance; the ionic liquid, with the extremely low viscosity characteristic of a liquid - like metal, forms a continuous lubricating phase under the directional guidance of the multi - level pores of the aerogel, enabling the slurry to achieve extension and penetration without external force and accurately filling millimeter - level cracks and complex cavities. The aerogel skeleton dynamically captures and releases the ionic liquid through nano - pores, and cooperates with the shear response characteristics of the bio - based cellulose network to achieve self - adaptive adjustment of the flow behavior with construction stress. It presents the characteristics of a water - like fluid under high shear and quickly reconstructs into an anti - settlement gel state when standing, essentially solving the common problem that it is difficult to balance the fluidity and stability of traditional materials; the ionic liquid - aerogel composite system not only acts as a'molecular - level lubricant' to reduce the flow resistance, but also triggers a directional hydration reaction during the curing stage through the hydrophobic interface effect of the aerogel and the polarity regulation of the ionic liquid, enabling the slurry to quickly form a dense reinforcing body after penetration. The bio - based cellulose network runs through the whole process and balances the rheological behavior through dynamic hydrogen - bond dissociation and association, not only ensuring the capillary penetration ability in extremely narrow spaces but also avoiding the risk of segregation and delamination. This 'flow - curing - strengthening' integrated design enables the material to show subversive engineering applicability in scenarios such as complex geological structures and special - shaped components, providing a new paradigm for green and low - carbon building materials. Description of the Drawings

[0021] Figure 1 It is the inspection result of the slump and spread diameter of the grouting materials prepared in Examples 1 - 6 and Comparative Example 1;

[0022] Figure 2 It is the compressive strength test result of the grouting materials prepared in Examples 1 - 6 and Comparative Example 1;

[0023] Figure 3 Viscosity test results of the grouting materials prepared in Examples 1-6 and Comparative Example 1;

[0024] Figure 4 Thixotropic recovery rate test results of the grouting materials prepared in Examples 1-6 and Comparative Example 1;

[0025] Figure 5 Scanning electron microscope characterization results of the ionic liquid aerogel composite and the grouting material prepared in Example 5. Detailed implementation manners

[0026] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all 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.

[0027] Unless otherwise defined, all professional and scientific terms used herein have the same meaning as those familiar to those skilled in the art. In addition, any methods and materials similar or equivalent to the described content can be applied to the present invention. The preferred implementation methods and materials described herein are only for illustrative purposes and do not limit the content of this application.

[0028] In the following embodiments, unless otherwise specified, all are conventional methods; in the materials used in the following embodiments, unless otherwise specified, the raw materials are newly purchased materials on the market. Among them, in the following examples and comparative examples, the Portland cement used is P.O42.5, and the specifications of the silica aerogel used are: porosity 92%, specific surface area 1000 m 2 / g, density 0.03 g / cm 3 , the fly ash in the active filler used is Class II fly ash, the metakaolin in the active filler used is Class II metakaolin powder, the polyether-modified silicone used is a conventional commercially available non-ionic type, the sulfonation degree of the sodium lignosulfonate used is 3.0 mmol / g, the moisture content is 3.2%, the hydroxypropyl methylcellulose used is construction grade EH100, and the activated carbon used is wood particle activated carbon, passing through an 18-mesh sieve, and the specific surface area is 1100 m 2 / g.

[0029] Example 1: This example provides a highly fluid grouting material, and the grouting material includes the following raw materials in parts by weight: 49 parts of Portland cement, 37 parts of ionic liquid aerogel composite, 10 parts of active filler, 0.5 part of 0.5% polyether-modified silicone, and 4 parts of hydroxypropyl methylcellulose;

[0030] The ionic liquid aerogel composite comprises the following raw materials in parts by weight: 1 part of silica aerogel, 10 parts of choline hydroxide, 5 parts of propionic acid, 2 parts of activated carbon, and 82 parts of deionized water. The specific preparation method is as follows:

[0031] S1: Weigh 10 parts of choline hydroxide and dissolve it in 82 parts of deionized water to prepare a choline solution. Weigh 5 parts of propionic acid and add it to the choline solution, then place it in a reaction kettle and stir magnetically at 4 °C and 100 rpm for 4 h to obtain a crude product.

[0032] S2: Weigh 2 parts of activated carbon and mix it with the crude product, stir magnetically at 100 rpm for 2 h, filter to remove the activated carbon, collect the filtrate, and filter the filtrate through a 0.22 μm filter membrane to obtain an ionic liquid.

[0033] S3: Weigh 1 part of silica aerogel, immerse it in absolute ethanol, ultrasonically clean it for 30 min, then vacuum dry it at 60 °C for 12 h to obtain an activated aerogel. Place the activated aerogel in a closed reaction kettle, introduce HMDS vapor, maintain it at 120 °C for 2 h, cool it to room temperature and then take it out to obtain a hydrophobic aerogel.

[0034] S4: Mix the hydrophobic aerogel with the ionic liquid and place it in a vacuum impregnation tank for 30 min to obtain an ionic liquid aerogel composite.

[0035] This example also provides a preparation method of a highly fluid grouting material, which specifically includes the following steps:

[0036] Step 1: Weigh 37 parts of the ionic liquid aerogel composite, preheat it at 40 °C for 30 min, then weigh 0.5 part of polyether-modified silicone and add it thereto, and perform high-speed shearing and pre-dispersion at 2000 rpm for 5 min to obtain a dispersion liquid.

[0037] Step 2: Weigh 49 parts of portland cement, dry it at 105 °C for 2 h, and pass it through an 80-mesh sieve to obtain activated cement. Weigh 10 parts of active filler, calcine it in a muffle furnace at 500 °C for 1 h, then put it into a mixer together with the activated cement and mix at 500 rpm for 10 min to obtain a uniform dry powder system.

[0038] Step 3: Slowly add the dispersion liquid to the uniform dry powder system, continue to mix at 1000 rpm for 15 min, and detect the viscosity to be 237 mPa·s to obtain a wet-mixed material.

[0039] Step 4: Weigh 4 parts of hydroxypropyl methylcellulose and add it to the wet-mixed material, let it stand for 20 min, then shear it at 2000 rpm for 3 min, degas it with a vacuum degasser for 20 min, and circulate it through a three-roll mill 2 times to obtain a grouting material.

[0040] Example 2: This example provides a high-fluidity grouting material, and the grouting material comprises the following raw materials in parts by weight: 54 parts of portland cement, 32 parts of ionic liquid aerogel composite, 12 parts of active filler, 0.5 part of 0.5% polyether-modified silicone, and 2 parts of hydroxypropyl methylcellulose;

[0041] The ionic liquid aerogel composite comprises the following raw materials in parts by weight: 1 part of silica aerogel, 16 parts of choline hydroxide, 8 parts of propionic acid, 2 parts of activated carbon, and 73 parts of deionized water. The specific preparation method is as follows:

[0042] S1: Weigh 16 parts of choline hydroxide and dissolve it in 73 parts of deionized water to prepare a choline solution. Weigh 8 parts of propionic acid, add it to the choline solution, and place it in a reaction kettle. Stir magnetically at 4 °C and 100 rpm for 4 h to obtain a crude product;

[0043] S2: Weigh 2 parts of activated carbon and mix it with the crude product. Stir magnetically at 100 rpm for 2 h, filter to remove the activated carbon, collect the filtrate, and filter the filtrate through a 0.22 μm filter membrane to obtain an ionic liquid;

[0044] S3: Weigh 1 part of silica aerogel, immerse it in absolute ethanol, ultrasonically clean it for 30 min, and then vacuum dry it at 60 °C for 12 h to obtain an activated aerogel. Place the activated aerogel in a closed reaction kettle, introduce HMDS vapor, maintain it at 120 °C for 2 h, cool it to room temperature and then take it out to obtain a hydrophobic aerogel;

[0045] S4: Mix the hydrophobic aerogel with the ionic liquid and place it in a vacuum impregnation tank for 30 min to obtain an ionic liquid aerogel composite.

[0046] This example also provides a preparation method of a high-fluidity grouting material, which specifically comprises the following steps:

[0047] Step 1: Weigh 32 parts of the ionic liquid aerogel composite, preheat it at 40 °C for 30 min, then weigh 0.5 part of 0.5% polyether-modified silicone and add it thereto. Perform high-speed shearing and pre-dispersion at 2000 rpm for 5 min to obtain a dispersion;

[0048] Step 2: Weigh 54 parts of portland cement, dry it at 105 °C for 2 h, pass it through an 80-mesh sieve to obtain activated cement. Weigh 12 parts of active filler, calcine it in a muffle furnace at 500 °C for 1 h, and then put it into a mixer together with the activated cement and mix at 500 rpm for 10 min to obtain a uniform dry powder system;

[0049] Step 3: Slowly add the dispersion to the uniform dry powder system, continue to mix at 1000 rpm for 15 min, and detect the viscosity to be 244 mPa·s to obtain a wet-mixed material;

[0050] Step 4: Weigh 2 parts of hypromellose, add it to the wet mixture, and let it stand for 20 min. Then shear it at 2000 rpm for 3 min, degas it with a vacuum degasser for 20 min, and circulate it through a three-roll mill 2 times to obtain the grouting material.

[0051] Example 3: This example provides a highly fluid grouting material, and the grouting material comprises the following raw materials in parts by weight: 59 parts of portland cement, 30 parts of ionic liquid aerogel composite, 10 parts of active filler, 0.5 part of emulsifying silicone oil, and 1 part of hypromellose;

[0052] The ionic liquid aerogel composite comprises the following raw materials in parts by weight: 1 part of silica aerogel, 20 parts of choline hydroxide, 10 parts of propionic acid, 2 parts of activated carbon, and 67 parts of deionized water. The specific preparation method is as follows:

[0053] S1: Weigh 20 parts of choline hydroxide and dissolve it in 67 parts of deionized water to prepare a choline solution. Weigh 10 parts of propionic acid, add it to the choline solution, and place it in a reaction kettle. Stir magnetically at 4°C and 100 rpm for 4 h to obtain a crude product;

[0054] S2: Weigh 2 parts of activated carbon, mix it with the crude product, stir magnetically at 100 rpm for 2 h, filter to remove the activated carbon, collect the filtrate, and filter the filtrate through a 0.22 μm filter membrane to obtain an ionic liquid;

[0055] S3: Weigh 1 part of silica aerogel, immerse it in absolute ethanol, ultrasonically clean it for 30 min, then vacuum dry it at 60°C for 12 h to obtain an activated aerogel. Place the activated aerogel in a closed reaction kettle, introduce HMDS vapor, maintain it at 120°C for 2 h, take it out after cooling to room temperature to obtain a hydrophobic aerogel;

[0056] S4: Mix the hydrophobic aerogel with the ionic liquid and place it in a vacuum impregnation tank for 30 min to obtain the ionic liquid aerogel composite.

[0057] This example also provides a preparation method of a highly fluid grouting material, which specifically comprises the following steps:

[0058] Step 1: Weigh 30 parts of the ionic liquid aerogel composite, preheat it at 40°C for 30 min, then weigh 0.5 part of emulsifying silicone oil and add it thereto. Perform high-speed shearing and pre-dispersion at 2000 rpm for 5 min to obtain a dispersion;

[0059] Step 2: Weigh 59 parts of portland cement, dry it at 105°C for 2 h, pass it through an 80-mesh sieve to obtain activated cement. Weigh 10 parts of active filler, calcine it in a muffle furnace at 500°C for 1 h, then put it into a blender together with the activated cement and mix at 500 rpm for 10 min to obtain a uniform dry powder system;

[0060] Step 3: Slowly add the dispersion liquid to the uniform dry powder system, continue to mix at 1000 rpm for 15 min, detect the viscosity of 268 mPa·s, and obtain the wet mixture.

[0061] Step 4: Weigh 1 part of hydroxypropyl methylcellulose and add it to the wet mixture. After standing for 20 min, shear it at 2000 rpm for 3 min, degas it with a vacuum degasser for 20 min, and circulate it through a three-roll mill 2 times to obtain the grouting material.

[0062] Example 4: This example provides a high-fluidity grouting material, and the grouting material comprises the following raw materials in parts by weight: 54 parts of portland cement, 30 parts of ionic liquid aerogel composite, 13 parts of active filler, 0.5 part of emulsifying silicone oil, and 3 parts of hydroxypropyl methylcellulose.

[0063] The ionic liquid aerogel composite comprises the following raw materials in parts by weight: 1 part of silica aerogel, 12 parts of choline hydroxide, 6 parts of propionic acid, 2 parts of activated carbon, and 79 parts of deionized water. The specific preparation method is as follows:

[0064] S1: Weigh 12 parts of choline hydroxide and dissolve it in 79 parts of deionized water to prepare a choline solution. Weigh 6 parts of propionic acid and add it to the choline solution, and place it in a reaction kettle. Stir magnetically at 4°C and 100 rpm for 4 h to obtain a crude product.

[0065] S2: Weigh 2 parts of activated carbon and mix it with the crude product, stir magnetically at 100 rpm for 2 h, filter to remove the activated carbon, collect the filtrate, and filter the filtrate through a 0.22 μm filter membrane to obtain the ionic liquid.

[0066] S3: Weigh 1 part of silica aerogel, immerse it in absolute ethanol, ultrasonically clean it for 30 min, and then vacuum dry it at 60°C for 12 h to obtain an activated aerogel. Place the activated aerogel in a sealed reaction kettle, introduce HMDS vapor, maintain it at 120°C for 2 h, cool it to room temperature and then take it out to obtain a hydrophobic aerogel.

[0067] S4: Mix the hydrophobic aerogel with the ionic liquid and place it in a vacuum impregnation tank for 30 min to obtain the ionic liquid aerogel composite.

[0068] This example also provides a preparation method of a high-fluidity grouting material, which specifically comprises the following steps:

[0069] Step 1: Weigh 30 parts of the ionic liquid aerogel composite, preheat it at 40°C for 30 min, then weigh 0.5 part of emulsifying silicone oil and add it thereto, and perform high-speed shear predispersion at 2000 rpm for 5 min to obtain a dispersion liquid.

[0070] Step 2: Weigh 54 parts of portland cement, dry it at 105 °C for 2 h, and pass it through an 80-mesh sieve to obtain activated cement. Weigh 13 parts of active filler, calcine it in a muffle furnace at 500 °C for 1 h, then put it into a mixer together with the activated cement, and mix at 500 rpm for 10 min to obtain a uniform dry powder system;

[0071] Step 3: Slowly add the dispersion liquid to the uniform dry powder system, continue to mix at 1000 rpm for 15 min, and measure the viscosity to be 257 mPa·s to obtain a wet mixture;

[0072] Step 4: Weigh 3 parts of hydroxypropyl methylcellulose, add it to the wet mixture and let it stand for 20 min, then shear it at 2000 rpm for 3 min, degas it with a vacuum degasser for 20 min, and circulate it through a three-roll mill 2 times to obtain the grouting material.

[0073] Example 5: This example provides a highly fluid grouting material, and the grouting material includes the following raw materials in parts by weight: 53 parts of portland cement, 33 parts of ionic liquid aerogel composite, 10 parts of active filler, 0.5 part of sodium lignosulfonate, and 4 parts of hydroxypropyl methylcellulose;

[0074] The ionic liquid aerogel composite includes the following raw materials in parts by weight: 1 part of silica aerogel, 14 parts of choline hydroxide, 7 parts of propionic acid, 2 parts of activated carbon, and 76 parts of deionized water. The specific preparation method is as follows:

[0075] S1: Weigh 14 parts of choline hydroxide and dissolve it in 76 parts of deionized water to prepare a choline solution. Weigh 7 parts of propionic acid, add it to the choline solution, and place it in a reaction kettle. Stir magnetically at 4 °C and 100 rpm for 4 h to obtain a crude product;

[0076] S2: Weigh 2 parts of activated carbon and mix it with the crude product, stir magnetically at 100 rpm for 2 h, filter to remove the activated carbon, collect the filtrate, and filter the filtrate through a 0.22-μm filter membrane to obtain the ionic liquid;

[0077] S3: Weigh 1 part of silica aerogel, immerse it in absolute ethanol, ultrasonically clean it for 30 min, then vacuum dry it at 60 °C for 12 h to obtain activated aerogel. Place the activated aerogel in a closed reaction kettle, introduce HMDS vapor, maintain it at 120 °C for 2 h, and take it out after cooling to room temperature to obtain hydrophobic aerogel;

[0078] S4: Mix the hydrophobic aerogel with the ionic liquid and place it in a vacuum impregnation tank for 30 min to obtain the ionic liquid aerogel composite.

[0079] This example also provides a preparation method of a highly fluid grouting material, which specifically includes the following steps:

[0080] Step 1: Weigh 33 parts of the ionic liquid aerogel composite and preheat it at 40 °C for 30 min. Then, weigh 0.5 part of sodium lignosulfonate and add it thereto. Perform high-speed shearing pre-dispersion at 2000 rpm for 5 min to obtain a dispersion liquid.

[0081] Step 2: Weigh 53 parts of portland cement, dry it at 105 °C for 2 h, and pass it through an 80-mesh sieve to obtain activated cement. Weigh 10 parts of active filler, calcine it in a muffle furnace at 500 °C for 1 h, and then put it into a blender together with the activated cement. Mix at 500 rpm for 10 min to obtain a uniform dry powder system.

[0082] Step 3: Slowly add the dispersion liquid to the uniform dry powder system, continue to mix at 1000 rpm for 15 min, and detect the viscosity to be 223 mPa·s to obtain a wet mixture.

[0083] Step 4: Weigh 4 parts of hydroxypropyl methylcellulose and add it to the wet mixture. After standing for 20 min, perform shearing at 2000 rpm for 3 min, degas with a vacuum degasser for 20 min, and circulate through a three-roll mill 2 times to obtain a grouting material.

[0084] Example 6: This example provides a high-fluidity grouting material, and the grouting material comprises the following raw materials in parts by weight: 58 parts of portland cement, 31 parts of ionic liquid aerogel composite, 10 parts of active filler, 0.5 part of sodium lignosulfonate, and 1 part of hydroxypropyl methylcellulose.

[0085] The ionic liquid aerogel composite comprises the following raw materials in parts by weight: 1 part of silica aerogel, 10 parts of choline hydroxide, 10 parts of propionic acid, 2 parts of activated carbon, and 77 parts of deionized water. The specific preparation method is as follows:

[0086] S1: Weigh 10 parts of choline hydroxide and dissolve it in 77 parts of deionized water to prepare a choline solution. Weigh 10 parts of propionic acid and add it to the choline solution, and place it in a reaction kettle. Perform magnetic stirring at 4 °C and 100 rpm for 4 h to obtain a crude product.

[0087] S2: Weigh 2 parts of activated carbon and mix it with the crude product. Perform magnetic stirring at 100 rpm for 2 h, filter to remove the activated carbon, collect the filtrate, and filter the filtrate through a 0.22-μm filter membrane to obtain an ionic liquid.

[0088] S3: Weigh 1 part of silica aerogel, immerse it in absolute ethanol, perform ultrasonic cleaning for 30 min, and then perform vacuum drying at 60 °C for 12 h to obtain an activated aerogel. Place the activated aerogel in a closed reaction kettle, introduce HMDS vapor, maintain at 120 °C for 2 h, and take it out after cooling to room temperature to obtain a hydrophobic aerogel.

[0089] S4: Mix the hydrophobic aerogel with the ionic liquid and place it in a vacuum impregnation tank for 30 min to obtain an ionic liquid aerogel composite.

[0090] This embodiment also provides a preparation method of a high-fluidity grouting material, which specifically includes the following steps:

[0091] Step 1: Weigh 31 parts of the ionic liquid aerogel composite and preheat it at 40 °C for 30 min. Then, weigh 0.5 part of sodium lignosulfonate and add it thereto, and perform high-speed shearing and pre-dispersion at 2000 rpm for 5 min to obtain a dispersion liquid;

[0092] Step 2: Weigh 58 parts of portland cement, dry it at 105 °C for 2 h, and pass it through an 80-mesh sieve to obtain activated cement. Weigh 10 parts of active filler, calcine it in a muffle furnace at 500 °C for 1 h, and then put it into a mixer together with the activated cement, and mix at 500 rpm for 10 min to obtain a uniform dry powder system;

[0093] Step 3: Slowly add the dispersion liquid to the uniform dry powder system, continue to mix at 1000 rpm for 15 min, and detect the viscosity to be 241 mPa·s to obtain a wet-mixed material;

[0094] Step 4: Weigh 1 part of hydroxypropyl methylcellulose and add it to the wet-mixed material. After standing for 20 min, perform shearing at 2000 rpm for 3 min, degas with a vacuum degasser for 20 min, and circulate through a three-roll mill 2 times to obtain the grouting material.

[0095] The difference between Comparative Example 1 and Example 5 is that 5 parts by weight of quartz sand and 28 parts by weight of deionized water are used to replace the ionic liquid aerogel composite, and the rest is the same as Example 5.

[0096] Slump and spread diameter investigation

[0097] Pour the grouting materials prepared in Examples 1-6 and Comparative Example 1 into a slump cone (upper opening diameter 100 mm, lower opening diameter 200 mm, height 300 mm) until it is full. After vertically lifting the cone, measure the slump height and spread diameter. The results are shown in Figure 1 .

[0098] Compressive strength investigation

[0099] Take the grouting materials prepared in Examples 1-6 and Comparative Example 1, pour them into 40 mm × 40 mm × 160 mm test blocks, and after standard curing (20 °C, RH>95%) for 28 days, use a universal testing machine to load them at a rate of 2.4 kN / s until failure, and measure the strength. The results are shown in Figure 2 .

[0100] Viscosity investigation

[0101] Use a rotational viscometer (rotor model LV-64) to measure the viscosities of the grouting materials prepared in Examples 1-6 and Comparative Example 1 at 25 °C, and the shear rate gradient is 0.1-100 s-1 , the viscosity test results are shown in Figure 3 .

[0102] Thixotropic recovery rate investigation

[0103] Under the condition of constant temperature of 25 °C ± 0.5 °C, a rheometer was used for testing. The grouts prepared in Examples 1-6 and Comparative Example 1 were loaded and then left standing for 5 min to eliminate the sample loading stress, and a steady-state shear rate of 10 s -1 was applied for 30 s to destroy the internal structure of the material to a stable low-viscosity state (η1), and the final shear stress was recorded; immediately stop shearing and start the time scan mode, leave standing for 60 s, monitor the structural recovery kinetic process, and collect the complex viscosity (η * ) once every 0.5 s; the ratio of the viscosity at the end of standing to the initial viscosity η0 before pre-shearing (previously measured at a low shear rate of 0.1 s -1 ) was defined as the thixotropic recovery rate R = (η * / η0) × 100%, and the results are shown in Figure 4 .

[0104] Morphology characterization

[0105] The ionic liquid aerogel composite and grout prepared in Example 5 were respectively dispersed on the specimen holder, sputter-coated with gold, and then placed under a scanning electron microscope (SEM) to observe the micro-morphology. The results are shown in Figure 5 .

[0106] Figure 1 The results show that the slump and spread diameter of Example 5 are better than those of other examples, and the flowability is significantly improved compared with the results of Comparative Example 1. This is mainly because the nano-pores of the hydrophobic aerogel act as a "liquid reservoir", releasing ionic liquid under the trigger of shear force to form a metal-like lubricating layer, which greatly reduces the friction between particles.

[0107] Figure 2 The compressive strength results show that the flowability of the grout in Comparative Example 1 prepared from traditional materials decreases with the strength loss. During the curing stage of the grout prepared in Example 5, the ionic liquid sealed in the aerogel is gradually released, continuously providing moisture to promote the deep hydration of cement, reducing shrinkage micro-cracks, and improving the overall compressive strength of the material. In Example 3, due to the low dosage of hydroxypropyl methylcellulose and the imbalance of the ionic liquid ratio, the cellulose network is loose, and the compressive strength is only 34.8 MPa, and the strength and flowability cannot be optimized synergistically.

[0108] Figure 3 The viscosity test results show that in Comparative Example 1, replacing the composite with quartz sand results in the loss of the ionic liquid lubricating phase, and the viscosity surges to 850 mPa·s, which is significantly higher than the viscosities of the grouts prepared in Examples 1-6, proving that the "liquid storage-release" function of the aerogel is the core driving force for low viscosity.

[0109] Figure 4 The thixotropic recovery rate test results show that in the grouting material prepared in Example 5, during the shearing stage, the ionic liquid in the pores is extruded and released to form a lubricating layer; when standing still, the hydrophobic skeleton of the aerogel re-adsorbs the ionic liquid, promoting network reconstruction and improving the thixotropic recovery ability; meanwhile, sodium lignosulfonate acts as an antifoaming agent, and its sulfonic acid group can be adsorbed on the surface of cement particles, reducing agglomeration through electrostatic repulsion, thereby reducing the interference of inter-particle friction on network recovery.

[0110] Figure 5 The SEM characterization results show that the ionic liquid aerogel composite presents a spherical structure with uniform shape and a particle size of about 200 nm. The microstructure of the grouting material is interconnected, with a skeleton and a large number of pores, having a certain support strength and good flow performance.

[0111] Although the embodiments of the present invention have been shown and described, it will be understood by those of ordinary skill in the art that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.

[0112] The above describes the present invention and its embodiments. Such description is not restrictive. What is shown in the drawings is only one of the embodiments of the present invention, and the actual application is not limited thereto. Generally speaking, if those of ordinary skill in the art are inspired by it and design similar methods and embodiments to this technical solution without creative efforts and without departing from the purpose of the present invention, they shall fall within the protection scope of the present invention.

Claims

1. A high-fluidity grouting material, characterized in that, The high-fluidity grouting material comprises the following raw materials in parts by weight: 49-59 parts of portland cement, 30-37 parts of ionic liquid aerogel composite, 10-13 parts of active filler, 0.5 part of defoamer and 1-4 parts of hypromellose; The defoamer used is 0.5% polyether modified silicone; The ionic liquid aerogel composite comprises the following raw materials: silica aerogel, choline hydroxide, propionic acid, activated carbon and deionized water. The mass ratio of silica aerogel, choline hydroxide, propionic acid, activated carbon and deionized water is 1:10-20:5-10:2:67-82. The specific preparation method of the ionic liquid aerogel composite is as follows: S1: Weigh choline hydroxide and dissolve it in deionized water, add propionic acid and react to obtain a crude product; S2: Weigh activated carbon and mix it with the crude product, filter to obtain an ionic liquid; S3: Weigh silica aerogel and perform activation and hydrophobic treatment to obtain a hydrophobic aerogel; S4: Mix the hydrophobic aerogel with the ionic liquid to obtain an ionic liquid aerogel composite.

2. The highly fluid grouting material according to claim 1, wherein In step S3, the activation process is to immerse the silica aerogel in absolute ethanol and then dry it, and the hydrophobic treatment uses HDMS vapor.

3. A highly fluid grouting material according to claim 1, characterized in that, The active filler is composed of metakaolin and fly ash with a mass ratio of 1:

1.

4. A method for preparing a highly fluid grouting material according to any one of claims 1-3, characterized in that, Specifically, it includes the following preparation steps: Step 1: Weigh the ionic liquid aerogel composite and preheat it, add the defoamer and pre-disperse it to obtain a dispersion; Step 2: Weigh portland cement and dry it to obtain activated cement. Weigh the active filler, calcine it and mix it with the activated cement to obtain a uniform dry powder system; Step 3: Add the dispersion to the uniform dry powder system to obtain a wet mix; Step 4: Weigh hypromellose and add it to the wet mix, shear and degas to obtain the high-fluidity grouting material.

5. The preparation method of a highly fluid grouting material according to claim 4, characterized in that, In step 2, the portland cement is dried and passed through an 80-mesh sieve. In step 3, the viscosity of the wet mix is 200-300 mPa·s.

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