High-fluidity grouting material and preparation method thereof

Abstract

The invention belongs to the technical field of building materials, and particularly relates to a high-fluidity grouting material and a preparation method thereof.The high-fluidity grouting material is prepared from, by weight, 49-59 parts of Portland cement, 30-37 parts of ionic liquid aerogel compound, 10-13 parts of active filler, 0.5 part of defoaming agent and 1-4 parts of hydroxypropyl methylcellulose; the ionic liquid aerogel compound loads choline propionate ionic liquid through a hydrophobic aerogel skeleton, a lubricating phase is released under triggering of shear stress, self-leveling filling and micro-crack vibration-free filling are achieved, a bio-based cellulose network balances flow and anti-segregation behaviors through dynamic hydrogen bonds, and the self-leveling filling and micro-crack vibration-free filling are achieved. The grouting material provided by the invention has the characteristics of low viscosity permeation, environmental response curing, low carbon and environmental protection, and is suitable for the fields of complex structure repair, underground engineering and green buildings.

Description

Technical Field

[0001] The 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 the safety of buildings and the life of the project. The traditional technical system uses silicate cement as the matrix, relying on the adsorption and dispersion of chemical water reducers and the optimization of mineral admixture grading to improve fluidity. However, it is subject to the limitations of the intrinsic properties and action mechanisms of the materials and 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-cement ratio conditions, the thixotropy regulation of the slurry has reached a bottleneck; 2. The material composition ratio is restricted by the theory of the densest packing of particles, and the interaction between micron-millimeter cross-scale particles is complex, making it difficult to achieve high fluidity and high density simultaneously; 3. Although nanomaterial modification can improve rheological properties, it is limited by the interfacial energy effect and process compatibility, and the contradiction between dispersion stability and cost-effectiveness is prominent in industrial applications. These defects cause traditional grouting materials to be prone to problems such as fluidity loss, shear stratification and insufficient environmental adaptability in scenarios such as ultra-high-rise pumping and deep-sea structure sealing, which seriously restricts the demand for refined construction of major projects.

[0003] In recent years, global infrastructure construction has extended to extreme environments such as deep earth, deep sea, and polar regions, which has put forward multi-dimensional coordinated requirements for the performance of grouting materials. However, the existing technical system has a single lubrication mechanism and weak functional expansion, forcing the engineering community to adopt multi-material compounding or post-processing processes, resulting in extended construction periods and a surge in carbon emissions. Although emerging technologies such as self-repair and phase change temperature regulation provide directions for performance upgrades, their compatibility with traditional grouting systems and full life cycle reliability remain 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 silicate cement as a matrix, ionic liquid-aerogel as a fluidity medium, and bio-based components as a dynamic control network, utilizing the metal-like flow characteristics of the ionic liquid and the pore-directional control ability of the aerogel to achieve adaptive flow of the grouting material in the construction stage and strength growth in the curing stage, thereby promoting the progress of engineering materials towards high fluidity, low carbonization, and functionalization.

[0005] To achieve the above purpose, the technical solution adopted by the present invention is as follows: The invention provides a high-fluidity grouting material, which comprises the following raw materials in parts by weight: 49-59 parts of silicate cement, 30-37 parts of ionic liquid aerogel composites, 10-13 parts of active fillers, 0.5 parts of defoaming agents and 1-4 parts of hydroxypropyl methylcellulose.

[0006] Furthermore, the active filler consists of metakaolin and fly ash in a mass ratio of 1:1.

[0007] Furthermore, the defoaming agent is selected from any one of 0.5% (w / v) polyether-modified siloxane, emulsified silicone oil, and sodium lignin sulfonate.

[0008] Furthermore, the ionic liquid aerogel composite comprises the following raw materials: silica aerogel, choline hydroxide, propionic acid, activated carbon and deionized water, wherein the mass ratio of the silica aerogel, choline hydroxide, propionic acid, activated carbon and deionized water is 1:10-20:5-10:2:67-82, and the preparation method of the ionic liquid aerogel composite comprises the following steps: S1: Silica aerogel, choline hydroxide, propionic acid, activated carbon and deionized water were weighed in a mass ratio of 1:10-20:5-10:2:67-82, the weighed choline hydroxide was dissolved in deionized water to prepare a choline solution, propionic acid was added to the choline solution and placed in a reactor, and magnetically stirred at 4°C and 100 rpm for 4 h to obtain a crude product; 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 the ionic liquid; S3: The silica aerogel was immersed in anhydrous ethanol, ultrasonically cleaned for 30 min, and then vacuum dried at 60 °C for 12 h to obtain activated aerogel. The activated aerogel was placed in a closed reactor, and HMDS (hexamethyldisilazane) vapor was introduced at 120 °C for 2 h. After cooling to room temperature, it was taken out to obtain a hydrophobic aerogel. S4: After the hydrophobic aerogel and the ionic liquid were mixed and placed in a vacuum impregnation tank for 30 min, an ionic liquid aerogel composite was obtained.

[0009] The present invention also provides a method for preparing a high-fluidity grouting material, which specifically comprises the following steps: Step 1: Weigh 30-37 parts of the ionic liquid aerogel composite, preheat at 40°C for 30 min, weigh 0.5 parts of the defoaming agent, add it, and pre-disperse at 2000 rpm for 5 min to obtain a dispersion; Step 2: Weigh 49-59 parts of silicate 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, roast it in a muffle furnace at 500°C for 1 h, and put it into a mixer together with the activated cement, mix it at 500 rpm for 10 min, and obtain a uniform dry powder system; Step 3: Slowly add the dispersion to the uniform dry powder system, continue mixing at 1000 rpm for 15 min, and measure the viscosity of 200-300 mPa·s to obtain a wet mixture; Step 4: Weigh 1-4 parts of hypromellose, add to the wet mixture and let it stand for 20 minutes, then shear at 2000 rpm for 3 minutes, degas with a vacuum degasser for 20 minutes, and grind twice with a three-roll mill to obtain a grouting material.

[0010] The beneficial effects achieved by the present invention are as follows: The high-fluidity grouting material provided by the present invention is endowed with breakthrough self-driven flow performance through the innovative fusion of silicate cement and ionic liquid aerogel composite medium; the ionic liquid has an extremely low viscosity characteristic similar to that of liquid metal, and forms a continuous lubricating phase under the directional guidance of the multi-level pores of the aerogel, so that the slurry can achieve extension and penetration without external force, and accurately fill millimeter-level cracks and complex cavities; the aerogel skeleton dynamically captures and releases the ionic liquid through nanopores, and cooperates with the shear response characteristics of the bio-based cellulose network to achieve adaptive adjustment of the flow behavior with construction stress, presents water-like fluid characteristics under high shear, and quickly reconstructs into an anti-sedimentation gel state when standing, which essentially solves the common problem that traditional materials are difficult to balance fluidity and stability; the ionic liquid-aerogel composite system not only acts as a "molecular-level lubricant" to reduce flow resistance, but also triggers a directional hydration reaction in the curing stage through the hydrophobic interface effect of the aerogel and the polarity regulation of the ionic liquid, so that the slurry quickly forms a dense reinforcement after the penetration is completed. The bio-based cellulose network runs through the entire process, and through the dynamic decomposition of hydrogen bonds to balance the rheological behavior, it not only ensures the capillary permeability in extremely narrow spaces, but also avoids the risk of segregation and stratification. This "flow-solidification-enhancement" integrated design enables the material to demonstrate subversive engineering applicability in scenes such as complex geological structures and special-shaped components, providing a new paradigm for green and low-carbon building materials. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 The results of investigating the slump and expansion diameter of the grouting materials prepared in Examples 1-6 and Comparative Example 1; Figure 2 The compressive strength test results of the grouting materials prepared in Examples 1-6 and Comparative Example 1; Figure 3 The viscosity test results of the grouting materials prepared in Examples 1-6 and Comparative Example 1; Figure 4 The thixotropic recovery rate test results of the grouting materials prepared in Examples 1-6 and Comparative Example 1; Figure 5 These are the scanning electron microscopy characterization results of the ionic liquid aerogel composite and grouting material prepared in Example 5. DETAILED DESCRIPTION

[0012] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only 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 ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0013] Unless otherwise defined, all professional and scientific terms used herein have the same meanings as those familiar to those skilled in the art. In addition, any methods and materials similar or equivalent to those described herein may be applied to the present invention. The preferred implementation methods and materials described herein are for demonstration purposes only and are not intended to limit the content of this application.

[0014] In the following examples, unless otherwise specified, conventional methods are used; the materials used in the following examples, unless otherwise specified, are all new materials purchased from the market, wherein the silicate cement used in the following examples and comparative examples is P.O42.5, and the silica aerogel used has a porosity of 92% and a specific surface area of ​​1000 m 2 / g, density 0.03 g / cm 3 The fly ash used in the active filler is Class II fly ash, the kaolin used in the active filler is Class II kaolin powder, the polyether-modified siloxane used is a conventional commercially available non-ionic type, the sodium lignin sulfonate used has a sulfonation degree of 3.0 mmol / g and a moisture content of 3.2%, the hydroxypropyl methylcellulose used is construction grade EH100, and the activated carbon used is wood granular activated carbon, which has been sieved through an 18-mesh screen and has a specific surface area of ​​1100 m 2 / g.

[0015] Example 1: This example provides a high-fluidity grouting material, which comprises the following raw materials in parts by weight: 49 parts of silicate cement, 37 parts of ionic liquid aerogel composite, 10 parts of active filler, 0.5 parts of 0.5% polyether-modified siloxane and 4 parts of hydroxypropyl methylcellulose; 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: S1: Weigh 10 parts of choline hydroxide and dissolve them in 82 parts of deionized water to prepare a choline solution. Weigh 5 parts of propionic acid and add them to the choline solution and place them in a reactor. Stir magnetically at 4°C and 100 rpm for 4 h to obtain a crude product. S2: Weigh 2 parts of activated carbon and mix 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; S3: Weigh 1 part of silica aerogel and immerse it in anhydrous ethanol. After ultrasonic cleaning for 30 min, vacuum dry it at 60 °C for 12 h to obtain activated aerogel. Place the activated aerogel in a closed reactor, introduce HMDS vapor, maintain at 120 °C for 2 h, cool it to room temperature and take it out to obtain hydrophobic aerogel. S4: After the hydrophobic aerogel and the ionic liquid were mixed and placed in a vacuum impregnation tank for 30 min, an ionic liquid aerogel composite was obtained.

[0016] This embodiment also provides a method for preparing a high-fluidity grouting material, which specifically comprises the following steps: Step 1: Weigh 37 parts of the ionic liquid aerogel composite, preheat at 40°C for 30 min, weigh 0.5 parts of 0.5% polyether-modified siloxane, add it, and pre-disperse at 2000 rpm for 5 min to obtain a dispersion; Step 2: Weigh 49 parts of silicate cement and dry them at 105°C for 2 h, pass them through an 80-mesh sieve to obtain activated cement, weigh 10 parts of active filler and roast them in a muffle furnace at 500°C for 1 h, then put them into a mixer together with the activated cement and mix them at 500 rpm for 10 min to obtain a uniform dry powder system; Step 3: Slowly add the dispersion into the uniform dry powder system, continue mixing at 1000 rpm for 15 min, and measure the viscosity to 237 mPa·s to obtain a wet mixture; Step 4: Weigh 4 parts of hypromellose, add it to the wet mixture and let it stand for 20 minutes, then shear at 2000 rpm for 3 minutes, degas with a vacuum degasser for 20 minutes, and cycle twice with a three-roll mill to obtain a grouting material.

[0017] Example 2: This example provides a high-fluidity grouting material, which comprises the following raw materials in parts by weight: 54 parts of silicate cement, 32 parts of ionic liquid aerogel composite, 12 parts of active filler, 0.5 parts of 0.5% polyether-modified siloxane and 2 parts of hydroxypropyl methylcellulose; 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: S1: Weigh 16 parts of choline hydroxide and dissolve them in 73 parts of deionized water to prepare a choline solution. Weigh 8 parts of propionic acid and add them to the choline solution and place them in a reactor. Stir magnetically at 4°C and 100 rpm for 4 h to obtain a crude product. S2: Weigh 2 parts of activated carbon and mix 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; S3: Weigh 1 part of silica aerogel and immerse it in anhydrous ethanol. After ultrasonic cleaning for 30 min, vacuum dry it at 60 °C for 12 h to obtain activated aerogel. Place the activated aerogel in a closed reactor, introduce HMDS vapor, maintain at 120 °C for 2 h, cool it to room temperature and take it out to obtain hydrophobic aerogel. S4: After the hydrophobic aerogel and the ionic liquid were mixed and placed in a vacuum impregnation tank for 30 min, an ionic liquid aerogel composite was obtained.

[0018] This embodiment also provides a method for preparing a high-fluidity grouting material, which specifically comprises the following steps: Step 1: Weigh 32 parts of the ionic liquid aerogel composite, preheat at 40°C for 30 min, weigh 0.5 parts of 0.5% polyether-modified siloxane, add it, and pre-disperse at 2000 rpm for 5 min to obtain a dispersion; Step 2: Weigh 54 parts of silicate cement and dry them at 105°C for 2 h, pass them through an 80-mesh sieve to obtain activated cement, weigh 12 parts of active filler and roast them in a muffle furnace at 500°C for 1 h, then put them into a mixer together with the activated cement and mix them at 500 rpm for 10 min to obtain a uniform dry powder system; Step 3: Slowly add the dispersion into the uniform dry powder system, continue mixing at 1000 rpm for 15 min, and measure the viscosity to 244 mPa·s to obtain a wet mixture; Step 4: Weigh 2 parts of hypromellose, add it to the wet mixture and let it stand for 20 minutes, then shear at 2000 rpm for 3 minutes, degas with a vacuum degasser for 20 minutes, and cycle twice with a three-roll mill to obtain a grouting material.

[0019] Example 3: This example provides a high-fluidity grouting material, which comprises the following raw materials in parts by weight: 59 parts of silicate cement, 30 parts of ionic liquid aerogel composite, 10 parts of active filler, 0.5 parts of emulsified silicone oil and 1 part of hydroxypropyl methylcellulose; 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: S1: Weigh 20 parts of choline hydroxide and dissolve them in 67 parts of deionized water to prepare a choline solution. Weigh 10 parts of propionic acid and add them to the choline solution and place them in a reactor. Stir magnetically at 4°C and 100 rpm for 4 h to obtain a crude product. S2: Weigh 2 parts of activated carbon and mix 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; S3: Weigh 1 part of silica aerogel and immerse it in anhydrous ethanol. After ultrasonic cleaning for 30 min, vacuum dry it at 60 °C for 12 h to obtain activated aerogel. Place the activated aerogel in a closed reactor, introduce HMDS vapor, maintain at 120 °C for 2 h, cool it to room temperature and take it out to obtain hydrophobic aerogel. S4: After the hydrophobic aerogel and the ionic liquid were mixed and placed in a vacuum impregnation tank for 30 min, an ionic liquid aerogel composite was obtained.

[0020] This embodiment also provides a method for preparing a high-fluidity grouting material, which specifically comprises the following steps: Step 1: Weigh 30 parts of the ionic liquid aerogel composite and preheat it at 40°C for 30 min, then weigh 0.5 parts of the emulsified silicone oil and add it thereto, and pre-disperse it at a high speed of 2000 rpm for 5 min to obtain a dispersion; Step 2: Weigh 59 parts of silicate cement and 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 and roast it in a muffle furnace at 500°C for 1 h, then put it into a mixer together with the activated cement, and mix it at 500 rpm for 10 min to obtain a uniform dry powder system; Step 3: Slowly add the dispersion into the uniform dry powder system, continue mixing at 1000 rpm for 15 min, and measure the viscosity to 268 mPa·s to obtain a wet mixture; Step 4: Weigh 1 portion of hypromellose, add it to the wet mixture and let it stand for 20 minutes, then shear at 2000 rpm for 3 minutes, degas with a vacuum degasser for 20 minutes, and cycle twice with a three-roll mill to obtain a grouting material.

[0021] Example 4: This example provides a high-fluidity grouting material, which comprises the following raw materials in parts by weight: 54 parts of silicate cement, 30 parts of ionic liquid aerogel composite, 13 parts of active filler, 0.5 parts of emulsified silicone oil and 3 parts of hydroxypropyl methylcellulose; 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: S1: Weigh 12 parts of choline hydroxide and dissolve them in 79 parts of deionized water to prepare a choline solution. Weigh 6 parts of propionic acid and add them to the choline solution and place them in a reactor. Stir magnetically at 4°C and 100 rpm for 4 h to obtain a crude product. S2: Weigh 2 parts of activated carbon and mix 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; S3: Weigh 1 part of silica aerogel and immerse it in anhydrous ethanol. After ultrasonic cleaning for 30 min, vacuum dry it at 60 °C for 12 h to obtain activated aerogel. Place the activated aerogel in a closed reactor, introduce HMDS vapor, maintain at 120 °C for 2 h, cool it to room temperature and take it out to obtain hydrophobic aerogel. S4: After the hydrophobic aerogel and the ionic liquid were mixed and placed in a vacuum impregnation tank for 30 min, an ionic liquid aerogel composite was obtained.

[0022] This embodiment also provides a method for preparing a high-fluidity grouting material, which specifically comprises the following steps: Step 1: Weigh 30 parts of the ionic liquid aerogel composite and preheat it at 40°C for 30 min, then weigh 0.5 parts of the emulsified silicone oil and add it thereto, and pre-disperse it at a high speed of 2000 rpm for 5 min to obtain a dispersion; Step 2: Weigh 54 parts of silicate cement and dry them at 105°C for 2 h, pass them through an 80-mesh sieve to obtain activated cement, weigh 13 parts of active filler and roast them in a muffle furnace at 500°C for 1 h, then put them into a mixer together with the activated cement, and mix them at 500 rpm for 10 min to obtain a uniform dry powder system; Step 3: Slowly add the dispersion into the uniform dry powder system, continue mixing at 1000 rpm for 15 min, and measure the viscosity to 257 mPa·s to obtain a wet mixture; Step 4: Weigh 3 parts of hypromellose, add it to the wet mixture and let it stand for 20 minutes, then shear at 2000 rpm for 3 minutes, degas with a vacuum degasser for 20 minutes, and cycle twice with a three-roll mill to obtain a grouting material.

[0023] Example 5: This example provides a high-fluidity grouting material, which comprises the following raw materials in parts by weight: 53 parts of silicate cement, 33 parts of ionic liquid aerogel composite, 10 parts of active filler, 0.5 parts of sodium lignin sulfonate and 4 parts of hydroxypropyl methylcellulose; The ionic liquid aerogel composite comprises 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: S1: Weigh 14 parts of choline hydroxide and dissolve them in 76 parts of deionized water to prepare a choline solution. Weigh 7 parts of propionic acid and add them to the choline solution and place them in a reactor. Stir magnetically at 4°C and 100 rpm for 4 h to obtain a crude product. S2: Weigh 2 parts of activated carbon and mix 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; S3: Weigh 1 part of silica aerogel and immerse it in anhydrous ethanol. After ultrasonic cleaning for 30 min, vacuum dry it at 60 °C for 12 h to obtain activated aerogel. Place the activated aerogel in a closed reactor, introduce HMDS vapor, maintain at 120 °C for 2 h, cool it to room temperature and take it out to obtain hydrophobic aerogel. S4: After the hydrophobic aerogel and the ionic liquid were mixed and placed in a vacuum impregnation tank for 30 min, an ionic liquid aerogel composite was obtained.

[0024] This embodiment also provides a method for preparing a high-fluidity grouting material, which specifically comprises the following steps: Step 1: Weigh 33 parts of the ionic liquid aerogel composite, preheat at 40°C for 30 min, weigh 0.5 parts of sodium lignin sulfonate, add it, and pre-disperse at 2000 rpm for 5 min to obtain a dispersion; Step 2: Weigh 53 parts of silicate cement and 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 and roast it in a muffle furnace at 500°C for 1 h, then put it into a mixer together with the activated cement, and mix it at 500 rpm for 10 min to obtain a uniform dry powder system; Step 3: Slowly add the dispersion into the uniform dry powder system, continue mixing at 1000 rpm for 15 min, and measure the viscosity to 223 mPa·s to obtain a wet mixture; Step 4: Weigh 4 parts of hypromellose, add it to the wet mixture and let it stand for 20 minutes, then shear at 2000 rpm for 3 minutes, degas with a vacuum degasser for 20 minutes, and cycle twice with a three-roll mill to obtain a grouting material.

[0025] Example 6: This example provides a high-fluidity grouting material, which comprises the following raw materials in parts by weight: 58 parts of silicate cement, 31 parts of ionic liquid aerogel composite, 10 parts of active filler, 0.5 parts of sodium lignin sulfonate and 1 part of hydroxypropyl methylcellulose; 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: S1: Weigh 10 parts of choline hydroxide and dissolve them in 77 parts of deionized water to prepare a choline solution. Weigh 10 parts of propionic acid and add them to the choline solution and place them in a reactor. Stir magnetically at 4°C and 100 rpm for 4 h to obtain a crude product. S2: Weigh 2 parts of activated carbon and mix 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; S3: Weigh 1 part of silica aerogel and immerse it in anhydrous ethanol. After ultrasonic cleaning for 30 min, vacuum dry it at 60 °C for 12 h to obtain activated aerogel. Place the activated aerogel in a closed reactor, introduce HMDS vapor, maintain at 120 °C for 2 h, cool it to room temperature and take it out to obtain hydrophobic aerogel. S4: After the hydrophobic aerogel and the ionic liquid were mixed and placed in a vacuum impregnation tank for 30 min, an ionic liquid aerogel composite was obtained.

[0026] This embodiment also provides a method for preparing a high-fluidity grouting material, which specifically comprises the following steps: Step 1: Weigh 31 parts of the ionic liquid aerogel composite and preheat it at 40°C for 30 min, then weigh 0.5 parts of sodium lignin sulfonate and add it thereto, and pre-disperse it at a high speed of 2000 rpm for 5 min to obtain a dispersion; Step 2: Weigh 58 parts of silicate cement and dry them at 105°C for 2 h, pass them through an 80-mesh sieve to obtain activated cement, weigh 10 parts of active filler and roast them in a muffle furnace at 500°C for 1 h, then put them into a mixer together with the activated cement, and mix them at 500 rpm for 10 min to obtain a uniform dry powder system; Step 3: Slowly add the dispersion into the uniform dry powder system, continue mixing at 1000 rpm for 15 min, and measure the viscosity to be 241 mPa·s to obtain a wet mixture; Step 4: Weigh 1 portion of hypromellose, add it to the wet mixture and let it stand for 20 minutes, then shear at 2000 rpm for 3 minutes, degas with a vacuum degasser for 20 minutes, and cycle twice with a three-roll mill to obtain a grouting material.

[0027] 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 instead of the ionic liquid aerogel composite, and the rest is the same as Example 5.

[0028] Slump and expansion diameter inspection Pour the grouts prepared in Examples 1-6 and Comparative Example 1 into a slump cone (upper diameter 100 mm, lower diameter 200 mm, height 300 mm) until full, lift the cone vertically and measure the slump height and expansion diameter. The results are shown in Figure 1 .

[0029] Compressive strength test The grouting materials prepared in Examples 1-6 and Comparative Example 1 were cast into test blocks of 40 mm×40 mm×160 mm. After standard curing (20°C, RH>95%) for 28 days, the test blocks were loaded to failure at a rate of 2.4 kN / s using a universal testing machine to measure the strength. The results are shown in Figure 2 .

[0030] Viscosity investigation The viscosity of the grouting materials prepared in Examples 1-6 and Comparative Example 1 was measured at 25°C using a rotational viscometer (rotor model LV-64) with a shear rate gradient of 0.1-100 s -1 , viscosity test results see Figure 3 .

[0031] Investigation of Thixotropic Recovery Rate Under the condition of constant temperature of 25℃±0.5℃, the rheometer was used for testing. The grouting materials prepared in Examples 1-6 and Comparative Example 1 were loaded and then left to stand for 5 min to eliminate the loading stress. The steady-state shear rate was applied for 10 s -1 The shear stress was recorded for 30 s to destroy the internal structure of the material to a stable low viscosity state (η1). The shear stress was immediately stopped and the time scan mode was started. The material was left to stand for 60 s to monitor the structural recovery kinetics. The complex viscosity (η1) was collected every 0.5 s. * ); the viscosity at the end of standing and the initial viscosity η0 before pre-shearing (previously at 0.1 s -1 The thixotropic recovery rate R is defined as the ratio of (η * / η0)×100%, the results are shown in Figure 4 .

[0032] Morphological characterization The ionic liquid aerogel composite and the grouting material prepared in Example 5 were dispersed on the grid, sprayed with gold and placed under a scanning electron microscope (SEM) to observe the microscopic morphology. Figure 5 .

[0033] Figure 1 The results show that the slump and expansion 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 nanopores of the hydrophobic aerogel act as a "liquid reservoir" to release ionic liquid under shear force triggering, forming a metal-like lubricating layer, which greatly reduces the friction between particles.

[0034] Figure 2 The compressive strength results show that the fluidity of the grouting material in Comparative Example 1 prepared from traditional materials is lost along with the strength. In the curing stage of the grouting material prepared in Example 5, the ionic liquid sealed in the aerogel is gradually released, and the continuous supply of moisture promotes the deep hydration of cement, reduces shrinkage microcracks, and improves the overall compressive strength of the material. In Example 3, due to the low dosage of hydroxypropyl methylcellulose and the unbalanced ratio of ionic liquid, the cellulose network is loose, the compressive strength is only 34.8 MPa, and the strength and fluidity are not optimized synergistically.

[0035] Figure 3The viscosity test results show that the viscosity of Comparative Example 1 increased sharply to 850 mPa·s due to the replacement of the composite with quartz sand, which lost the ionic liquid lubricating phase. This is significantly higher than the viscosity of the grouting materials prepared in Examples 1-6, proving that the "liquid storage-release" function of aerogel is the core driving force for low viscosity.

[0036] Figure 4 The thixotropic recovery rate test results show that in the shear stage, the ionic liquid in the pores of the grouting material prepared in Example 5 is squeezed and released to form a lubricating layer; when standing still, the hydrophobic skeleton of the aerogel re-absorbs the ionic liquid to promote network reconstruction and improve the thixotropic recovery ability; at the same time, sodium lignin sulfonate is used as a defoaming 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 friction between particles on network recovery.

[0037] Figure 5 The SEM characterization results show that the ionic liquid aerogel composite has a spherical structure with uniform shape and a particle size of about 200 nm. The microstructure of the grouting material is interconnected, and there is a skeleton and a large number of pores, which has a certain supporting strength and good flow properties.

[0038] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

[0039] The present invention and its implementation methods are described above, which is not restrictive. The drawings are only one of the implementation methods of the present invention, and the actual application is not limited thereto. In short, if ordinary technicians in the field are inspired by it and design methods and embodiments similar to the technical solution without creativity without departing from the purpose of the invention, they should all 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 silicate cement, 30-37 parts of ionic liquid aerogel composite, 10-13 parts of active filler, 0.5 parts of defoamer and 1-4 parts of hydroxypropyl methylcellulose; The ionic liquid aerogel composite comprises the following raw materials: silicon dioxide aerogel, choline hydroxide, propionic acid, activated carbon and deionized water. 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 to react, and obtain a crude product; S2: Weigh the activated carbon and mix with the crude product, filter and obtain the ionic liquid; S3: Weighing and activating the silica aerogel, and subjecting it to hydrophobic treatment to obtain a hydrophobic aerogel; S4: mixing the hydrophobic aerogel with the ionic liquid to obtain an ionic liquid aerogel composite.

2. A high fluidity grouting material according to claim 1, characterized in that: The mass ratio of the silica aerogel, choline hydroxide, propionic acid, activated carbon and deionized water is 1:10-20:5-10:2:67-82; In step S3, the activation process is to immerse the silica aerogel in anhydrous ethanol and then dry it, and the hydrophobic treatment uses HDMS vapor.

3. A high fluidity grouting material according to claim 1, characterized in that: The active filler consists of metakaolin and fly ash in a mass ratio of 1:

1.

4. A high-fluidity grouting material according to claim 1, characterized in that: The defoamer is selected from any one of 0.5% polyether modified siloxane, emulsified silicone oil, and sodium lignin sulfonate.

5. A method for preparing a high-fluidity grouting material according to any one of claims 1 to 4, characterized in that: The specific preparation steps include: Step 1: Weigh the ionic liquid aerogel composite, preheat it, add a defoaming agent and pre-disperse it to obtain a dispersion; Step 2: Weigh silicate cement and dry it to obtain activated cement, weigh active filler and roast it and mix it with the activated cement to obtain a uniform dry powder system; Step 3: adding the dispersion liquid to the uniform dry powder system to obtain a wet mixture; Step 4: Weigh hydroxypropyl methylcellulose and add it to the wet mixture, shear and degas to obtain a high-fluidity grouting material.

6. The method for preparing a high-fluidity grouting material according to claim 5, characterized in that: In step 2, the silicate 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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