Low-heat-disturbance grouting suitable for frozen soil construction and preparation method thereof

Abstract

This invention discloses a low-heat disturbance grout suitable for construction in frozen soil and its preparation method. By weight, the raw materials include: 20-30 parts sulfoaluminate cement, 35-40 parts granulated blast furnace slag powder, 20-22.5 parts metakaolin, 15-17.5 parts alkali activator with slow-release effect, 290-310 parts fine aggregate, 30-35 parts water, 3-4 parts calcium nitrite, 0.4-0.6 parts water-reducing agent, and 0.02-0.04 parts triethanolamine. This invention significantly reduces the heat release during hydration while ensuring strength development, solving the problem of rapid, large, and concentrated heat release during cement hydration in frozen soil environments, which causes thermal disturbance to the frozen soil.

Description

Technical Field

[0001] This invention relates to the field of building materials technology, specifically to a low-thermal-disturbance grout suitable for construction in frozen soil and its preparation method. Background Technology

[0002] Drilled pile foundations are the most common construction method in permafrost regions. However, the cement-based materials in the grout release heat rapidly, in large quantities, and in a concentrated manner during hydration. This heat causes a rapid rise in the temperature of the surrounding soil, altering the original thermal balance of the permafrost environment. Furthermore, permafrost has a long-term strength that is far lower than its instantaneous strength. Once the temperature exceeds 0°C, the thawing and rheological properties of the permafrost reduce its freezing strength and the bearing capacity of the foundation, thus damaging the permafrost environment. Simultaneously, the instability of the surrounding soil severely impacts the stability of the pile foundation, jeopardizing construction safety.

[0003] To avoid the impact of thermal disturbance on permafrost foundations, various construction methods have been explored. Chinese utility model patent CN202122614079.5 proposes a drilled pile-heater foundation arrangement structure, which embeds heaters in the permafrost around the pile. The cooling performance of the heaters reduces thermal disturbance to the surrounding soil, thereby enhancing the stability of the pile foundation. Chinese invention patent CN202310670269.X proposes an active cooling construction device and method for drilled piles in permafrost areas. This method removes the heat released during hydration from the soil through a cooling circulation device before heat exchange and diffusion, reducing the degree of thermal disturbance to the permafrost during the grouting and hydration reaction processes. Chinese invention patent CN202210882672.4 proposes a CFG pile-raft composite foundation structure and construction method that can mitigate thermal disturbance in permafrost. This method uses a low-temperature phase change material layer for energy storage and temperature sensors for temperature control, reducing damage to the CFG pile and thermal disturbance to the surrounding soil, especially the permafrost layer. The aforementioned methods reduce thermal disturbance in permafrost environments from the perspective of construction methods and processes. However, these methods all require additional equipment, which not only increases costs but also requires corresponding human resources. Therefore, a low-thermal-disturbance grout that is easy to construct, has low thermal disturbance, and can rapidly develop strength at low temperatures urgently needs to be developed. Summary of the Invention

[0004] To address the problems existing in the prior art, the purpose of this invention is to provide a low-thermal-disturbance grouting method suitable for frozen soil construction and its preparation method. The grouting of this invention can rapidly develop strength at low temperatures and has the characteristics of low thermal disturbance and convenient construction.

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

[0006] A low-heat disturbance grout suitable for construction in frozen soil, comprising, by weight, the following raw materials:

[0007] 20-30 parts of sulfoaluminate cement, 35-40 parts of granulated blast furnace slag powder, 20-22.5 parts of metakaolin, 15-17.5 parts of alkali activator with slow-release effect, 290-310 parts of fine aggregate, 30-35 parts of water, 3-4 parts of calcium nitrite, 0.4-0.6 parts of water-reducing agent, and 0.02-0.04 parts of triethanolamine.

[0008] Preferably, the sulfoaluminate cement is 52.5 cement.

[0009] Preferably, the granulated blast furnace slag powder is of grade S95.

[0010] Preferably, the metakaolin has a mesh size of 600 or higher.

[0011] Preferably, the alkali activator is made from raw materials and sufficient deionized water. By weight percentage, the raw materials of the alkali activator include: 90%-92% anhydrous sodium silicate, 6.4%-8% hydroxypropyl methylcellulose, and 1.6%-2% gelatin.

[0012] Preferably, the preparation method of the alkaline activator of the present invention includes:

[0013] Deionized water is heated to 85-90℃, then hydroxypropyl methylcellulose and gelatin are added and stirred to disperse them evenly. Stirring continues, and the temperature is lowered to room temperature to obtain an aged and homogeneous solution. Anhydrous sodium silicate is added to the aged and homogeneous solution, and stirring is continued to ensure thorough mixing. The mixture is then dried by forced air drying to remove all moisture, yielding an alkali activator with sustained-release function.

[0014] Preferably, after adding hydroxypropyl methylcellulose and gelatin to water, the mixture is stirred at 120-130 r / min for 2-2.2 h to ensure uniform dispersion of the hydroxypropyl methylcellulose and gelatin. Then, the mixture is stirred at 65-75 r / min until the temperature is reduced to room temperature, resulting in an aged and homogeneous solution. Anhydrous sodium silicate is added to the aged and homogeneous solution, and the stirring rate is 120-130 r / min for 1.5-2 h. When the mixture is dried by forced air drying, the drying temperature is 38-42℃ and the drying time is 24-36 h.

[0015] Preferably, the fine aggregate is quartz sand with a fineness modulus of 2.3-2.5.

[0016] Preferably, the water-reducing agent is a polycarboxylate water-reducing agent.

[0017] The method for preparing low-thermal-disturbance grout suitable for frozen soil construction as described above includes the following steps:

[0018] Sulfoaluminate cement, granulated blast furnace slag powder, metakaolin, alkali activator and fine aggregate are mixed to obtain uniform raw materials;

[0019] Calcium nitrite, water-reducing agent, triethanolamine and water are mixed to form a homogeneous solution;

[0020] The raw materials and homogeneous solution are sealed and pre-cooled to obtain pre-cooled raw materials and pre-cooled homogeneous solution, with a pre-cooling temperature of -2 to 0°C.

[0021] The pre-cooled raw materials and the pre-cooled homogeneous solution are mixed and stirred to form a homogeneous slurry, thus obtaining the low-heat disturbance grout suitable for frozen soil construction.

[0022] The present invention has the following beneficial effects:

[0023] The low-heat disturbance grouting method for frozen soil construction provided by this invention is a composite of sulfoaluminate cement, granulated blast furnace slag powder, metakaolin, and an alkali activator with a slow-release effect. It utilizes the rapid hydration rate of sulfoaluminate cement at low temperatures, which generates a large amount of ettringite crystals, resulting in high early strength and allowing the grouting to quickly reach its critical frost resistance strength. Simultaneously, the slow-release alkali activator slowly activates the granulated blast furnace slag powder and metakaolin, allowing the alkali activator to react continuously under a slow alkali release, generating hydrated calcium silicate and hydrated calcium aluminosilicate gel substances that contribute to strength. This reaction process is not violent and is continuous, significantly reducing the heat release during hydration while ensuring strength development, thus minimizing thermal disturbance to the frozen soil environment caused by cement hydration. As can be seen from the above analysis, the low-heat disturbance grouting method of this invention can rapidly develop strength at low temperatures, exhibiting low heat disturbance and convenient construction. Furthermore, the use of a large amount of solid waste in this invention is beneficial for green environmental protection and sustainable development.

[0024] The method for preparing low-thermal disturbance grout provided by this invention reduces the reliance on complex external temperature control equipment. The materials used are readily available, low in cost, and non-toxic. The preparation process is simple and has the advantages of convenient construction, wide applicability, and economic and environmental benefits. Detailed Implementation

[0025] The present invention will be further described below through specific embodiments. The illustrative embodiments and descriptions herein are used to explain the present invention, but are not intended to limit the present invention.

[0026] This invention relates to a method for preparing low-thermal-disturbance grout for frozen soil construction, comprising the following steps:

[0027] Step 1: Place 20-30 parts by weight of sulfoaluminate cement, 35-40 parts by weight of granulated blast furnace slag powder, 20-22.5 parts by weight of metakaolin, 15-17.5 parts by weight of alkali activator, and 290-310 parts by weight of fine aggregate into a mixer and stir at a speed of 135-145 r / min for 4-6 minutes to ensure that the materials are fully mixed and homogeneous, thus obtaining a mixed material.

[0028] Step 2: Add 3-4 parts by weight of calcium nitrite, 0.4-0.6 parts by weight of water-reducing agent, and 0.02-0.04 parts by weight of triethanolamine to 30-35 parts by weight of water, and stir to form a homogeneous solution.

[0029] Step 3: Place the mixed material obtained in Step 1 and the homogeneous solution obtained in Step 2 in an environment of -2 to 0℃ for 24-36 hours to pre-cool them so that the temperature of the mixed material and the solution is between -2 and 0℃.

[0030] Step 4: Place the pre-cooled mixed material and homogeneous solution obtained in Step 3 into a mixer and stir at a speed of 135-145 r / min for 3-5 min, then stir at a speed of 280-290 r / min for 2-3 min to form a homogeneous slurry, thus obtaining a low-heat disturbance grout suitable for frozen soil construction.

[0031] In the above-mentioned scheme of the present invention, the sulfoaluminate cement is 52.5 cement, the granulated blast furnace slag powder is S95 grade, the metakaolin is above 600 mesh, the fine aggregate is quartz sand with a fineness modulus of 2.3-2.5, and the water-reducing agent is polycarboxylate high-efficiency water-reducing agent.

[0032] The alkali activator is made from raw materials and sufficient deionized water. By weight percentage, the raw materials of the alkali activator include: 90%-92% anhydrous sodium silicate, 6.4%-8% hydroxypropyl methylcellulose, and 1.6%-2% gelatin.

[0033] The preparation method of the alkali activator includes: heating deionized water to 85-90℃, wherein the mass of the deionized water is 30-34 times the mass of hydroxypropyl methylcellulose; adding hydroxypropyl methylcellulose and gelatin to the deionized water; stirring at 120-130 r / min for 2-2.2 h to ensure uniform dispersion of hydroxypropyl methylcellulose and gelatin; then stirring slowly at 65-75 r / min and cooling to room temperature to obtain an aged and homogeneous solution; adding anhydrous sodium silicate to the aged and homogeneous solution; stirring at 120-130 r / min for 1.5-2 h to ensure thorough and uniform mixing of the anhydrous sodium silicate to obtain a homogeneous mixture; and drying the mixture in a forced-air drying oven at 38-42℃ for 24-36 h to remove moisture, thereby obtaining an alkali activator with sustained-release function.

[0034] This invention addresses the problem of rapid, large, and concentrated heat release during cement hydration in grouting under frozen soil conditions, which causes thermal disturbance to the frozen soil. It develops a low-thermal-disturbance grouting suitable for frozen soil construction. This invention utilizes a small amount of sulfoaluminate cement to ensure the early strength of the grouting at low temperatures, and a large amount of granulated blast furnace slag powder and metakaolin to reduce the heat of hydration. Simultaneously, it employs an alkali activator with a slow-release effect, allowing the granulated blast furnace slag powder and metakaolin to continuously react under sustained, slow alkali release, generating hydrated calcium silicate and hydrated calcium aluminosilicate gel substances that contribute to later-stage strength. This significantly reduces the heat release during hydration while ensuring strength development, thus minimizing thermal disturbance to the frozen soil environment caused by cement hydration.

[0035] Example 1:

[0036] This embodiment describes a method for preparing low-thermal-disturbance grout for frozen soil construction, comprising the following steps:

[0037] Step 1: Weigh out 30 parts of 52.5 sulfoaluminate cement, 35 parts of S95 grade granulated blast furnace slag powder, 20 parts of metakaolin, 15 parts of alkali activator, and 310 parts of quartz sand with a fineness modulus of 2.5 by weight and place them in a mixer. Stir at 145 r / min for 6 minutes until uniform raw materials are formed.

[0038] Step 2: Weigh out 4 parts calcium nitrite, 0.6 parts polycarboxylate superplasticizer, and 0.04 parts triethanolamine by weight and add them to 35 parts water. Stir to form a homogeneous solution.

[0039] Step 3: Place the mixed material obtained in Step 1 and the homogeneous solution obtained in Step 2 in an environment of 0℃ for 36 hours to pre-cool them so that the temperature of the mixed material and the homogeneous solution is 0℃.

[0040] Step 4: Place the pre-cooled mixed material and homogeneous solution obtained in Step 3 into a mixer, stir at 145 r / min for 5 min, and then stir at 290 r / min for 3 min to form a homogeneous slurry, thus obtaining a low-heat disturbance grout suitable for frozen soil construction.

[0041] The raw materials of the alkali activator used in this embodiment, by weight percentage, include: 90% anhydrous sodium silicate, 8% hydroxypropyl methylcellulose, and 2% gelatin.

[0042] The preparation method of the alkali activator includes: heating deionized water to 90°C, wherein the mass of the deionized water is 34 times the mass of hydroxypropyl methylcellulose; adding hydroxypropyl methylcellulose and gelatin to the deionized water; stirring at 130 r / min for 2.2 h to ensure uniform dispersion of hydroxypropyl methylcellulose and gelatin; then stirring slowly at 75 r / min and cooling to room temperature to obtain an aged and homogeneous solution; adding anhydrous sodium silicate to the aged and homogeneous solution; stirring at 130 r / min for 2 h to ensure thorough and uniform mixing of the anhydrous sodium silicate to obtain a homogeneous mixture; and drying the mixture in a 42°C forced-air drying oven for 36 h to remove moisture, thereby obtaining the alkali activator.

[0043] The low-heat disturbance grout prepared in this embodiment, suitable for construction in frozen soil, was poured into a 40cm×40cm×160cm mortar mold, compacted by vibration, and then covered with a film for curing at -5℃. The strength was determined according to the method specified in GB / T17671-2021 "Test Method for Strength of Cement Mortar (ISO)". The compressive strengths at 1d, 7d, and 28d were measured to be 5.7MPa, 38.2MPa, and 61.5MPa, respectively.

[0044] The low-heat disturbance grout prepared in this embodiment, suitable for frozen soil construction, was poured into a 100cm×100cm×100cm mold. After compaction, it was placed in a -5℃ environment, and the highest core temperature was measured and recorded. The highest core temperature was found to be -0.1℃.

[0045] Example 2:

[0046] This embodiment describes a method for preparing low-thermal-disturbance grout for frozen soil construction, comprising the following steps:

[0047] Step 1: Weigh out 25 parts of 52.5 sulfoaluminate cement, 37.5 parts of S95 grade granulated blast furnace slag powder, 21.3 parts of metakaolin, 16.2 parts of alkali activator, and 300 parts of quartz sand with a fineness modulus of 2.4 by weight and place them in a mixer. Stir at 140 r / min for 5 minutes until uniform raw materials are formed.

[0048] Step 2: Weigh out 3.5 parts of calcium nitrite, 0.5 parts of polycarboxylate superplasticizer, and 0.03 parts of triethanolamine by weight and add them to 32.5 parts of water. Stir to form a homogeneous solution.

[0049] Step 3: Place the mixed material obtained in Step 1 and the homogeneous solution obtained in Step 2 in an environment of -1℃ for 30 hours to pre-cool them so that the temperature of the mixed material and the homogeneous solution is at -1℃.

[0050] Step 4: Place the pre-cooled mixed material and homogeneous solution obtained in Step 3 into a mixer and stir at 140 r / min for 4 min, then stir at 285 r / min for 2.5 min to form a homogeneous slurry, thus obtaining a low-heat disturbance grout suitable for frozen soil construction.

[0051] The raw materials of the alkali activator used in this embodiment, by weight percentage, include: 91% anhydrous sodium silicate, 7.2% hydroxypropyl methylcellulose, and 1.8% gelatin.

[0052] The preparation method of the alkali activator includes: heating deionized water to 87°C, wherein the mass of the deionized water is 32 times the mass of hydroxypropyl methylcellulose; adding hydroxypropyl methylcellulose and gelatin to the deionized water; stirring at 125 r / min for 2.1 h to ensure uniform dispersion of hydroxypropyl methylcellulose and gelatin; then stirring slowly at 70 r / min and cooling to room temperature to obtain an aged and homogeneous solution; adding anhydrous sodium silicate to the aged and homogeneous solution; stirring at 125 r / min for 1.7 h to ensure thorough and uniform mixing of the anhydrous sodium silicate to obtain a homogeneous mixture; and drying the mixture in a 40°C forced-air drying oven for 32 h to remove moisture, thereby obtaining the alkali activator.

[0053] The low-heat disturbance grout prepared in this embodiment, suitable for construction in frozen soil, was poured into a 40cm×40cm×160cm mortar mold, compacted by vibration, and then covered with a film for curing at -5℃. The strength was determined according to the method specified in GB / T17671-2021 "Test Method for Strength of Cement Mortar (ISO)". The compressive strengths at 1d, 7d, and 28d were measured to be 4.8MPa, 35.5MPa, and 57.9MPa, respectively.

[0054] The low-heat disturbance grout prepared in this embodiment, suitable for frozen soil construction, was poured into a 100cm×100cm×100cm mold. After compaction, it was placed in a -5℃ environment, and the highest core temperature was measured and recorded. The highest core temperature was found to be -0.7℃.

[0055] Example 3:

[0056] This embodiment describes a method for preparing low-thermal-disturbance grout for frozen soil construction, comprising the following steps:

[0057] Step 1: Weigh out 22 parts of 52.5 sulfoaluminate cement, 37 parts of S95 grade granulated blast furnace slag powder, 21 parts of metakaolin, 16 parts of alkali activator, and 295 parts of quartz sand with a fineness modulus of 2.4 by weight and place them in a mixer. Stir at 140 r / min for 5 minutes until uniform raw materials are formed.

[0058] Step 2: Weigh out 3 parts calcium nitrite, 0.5 parts polycarboxylate superplasticizer, and 0.03 parts triethanolamine by weight and add them to 33 parts water. Stir to form a homogeneous solution.

[0059] Step 3: Place the mixed material obtained in Step 1 and the homogeneous solution obtained in Step 2 in an environment of -2℃ for 30 hours to pre-cool them so that the temperature of the mixed material and the solution is at -2℃.

[0060] Step 4: Place the pre-cooled mixed material and homogeneous solution obtained in Step 3 into a mixer, stir at 138 r / min for 4 min, and then stir at 285 r / min for 3 min to form a homogeneous slurry, thus obtaining a low-heat disturbance grout suitable for frozen soil construction.

[0061] The raw materials of the alkali activator used in this embodiment, by weight percentage, include: 91.5% anhydrous sodium silicate, 6.8% hydroxypropyl methylcellulose, and 1.7% gelatin.

[0062] The preparation method of the alkali activator includes: heating deionized water to 88°C, wherein the mass of the deionized water is 31 times the mass of hydroxypropyl methylcellulose; adding hydroxypropyl methylcellulose and gelatin to the deionized water; stirring at 124 r / min for 2.1 h to ensure uniform dispersion of hydroxypropyl methylcellulose and gelatin; then stirring slowly at 72 r / min and cooling to room temperature to obtain an aged and homogeneous solution; adding anhydrous sodium silicate to the aged and homogeneous solution; stirring at 125 r / min for 1.8 h to ensure thorough mixing of the anhydrous sodium silicate to obtain a homogeneous mixture; and drying the mixture in a 40°C forced-air drying oven for 28 h to remove moisture, thereby obtaining the alkali activator.

[0063] The low-heat disturbance grout prepared in this embodiment, suitable for frozen soil construction, was poured into a 40cm×40cm×160cm mortar mold, compacted by vibration, and then covered with a film for curing at -5℃. The strength was determined according to the method specified in GB / T17671-2021 "Test Method for Strength of Cement Mortar (ISO)". The compressive strengths at 1d, 7d, and 28d were measured to be 5.2MPa, 40.2MPa, and 63.6MPa, respectively.

[0064] The low-heat disturbance grout prepared in this embodiment, suitable for frozen soil construction, was poured into a 100cm×100cm×100cm mold. After compaction, it was placed in a -5℃ environment, and the highest core temperature was measured and recorded. The highest core temperature was found to be -1.2℃.

[0065] Example 4:

[0066] This embodiment describes a method for preparing low-thermal-disturbance grout for frozen soil construction, comprising the following steps:

[0067] Step 1: Weigh out 20 parts of 52.5 sulfoaluminate cement, 40 parts of S95 grade granulated blast furnace slag powder, 22.5 parts of metakaolin, 17.5 parts of alkali activator, and 290 parts of quartz sand with a fineness modulus of 2.3 by weight and place them in a mixer. Stir at 135 r / min for 4 minutes until uniform raw materials are formed.

[0068] Step 2: Weigh out 3 parts calcium nitrite, 0.4 parts polycarboxylate superplasticizer, and 0.02 parts triethanolamine by weight and add them to 30 parts water. Stir to form a homogeneous solution.

[0069] Step 3: Place the mixed material obtained in Step 1 and the homogeneous solution obtained in Step 2 in an environment of -2℃ for 24 hours to pre-cool them so that the temperature of the mixed material and the solution is at -2℃.

[0070] Step 4: Place the pre-cooled mixed material and homogeneous solution obtained in Step 3 into a mixer, stir at 135 r / min for 3 min, and then stir at 280 r / min for 2 min to form a homogeneous slurry, thus obtaining a low-heat disturbance grout suitable for frozen soil construction.

[0071] The raw materials of the alkali activator used in this embodiment, by weight percentage, include: 92% anhydrous sodium silicate, 6.4% hydroxypropyl methylcellulose, and 1.6% gelatin.

[0072] The preparation method of the alkali activator includes: heating deionized water to 85°C, wherein the mass of the deionized water is 30 times the mass of hydroxypropyl methylcellulose; adding hydroxypropyl methylcellulose and gelatin to the deionized water; stirring at 120 r / min for 2 hours to ensure uniform dispersion of hydroxypropyl methylcellulose and gelatin; then stirring slowly at 65 r / min and cooling to room temperature to obtain an aged and homogeneous solution; adding anhydrous sodium silicate to the aged and homogeneous solution; stirring at 120 r / min for 1.5 hours to ensure thorough mixing of the anhydrous sodium silicate to obtain a homogeneous mixture; and placing the mixture in a 38°C forced-air drying oven for 24 hours to remove moisture, thereby obtaining the alkali activator.

[0073] The low-heat disturbance grout prepared in this embodiment, suitable for construction in frozen soil, was poured into a 40cm×40cm×160cm mortar mold, compacted by vibration, and then covered with a film for curing at -5℃. The strength was determined according to the method specified in GB / T17671-2021 "Test Method for Strength of Cement Mortar (ISO)". The compressive strengths at 1d, 7d, and 28d were measured to be 4.5MPa, 41.2MPa, and 58.8MPa, respectively.

[0074] The low-heat disturbance grout prepared in this embodiment, suitable for frozen soil construction, was poured into a 100cm×100cm×100cm mold. After compaction, it was placed in a -5℃ environment, and the highest core temperature was measured and recorded. The highest core temperature was found to be -1.5℃.

[0075] As can be seen from the compressive strength of the low-thermal-disturbance grout suitable for frozen soil construction prepared in the above embodiments, the low-thermal-disturbance grout prepared by the present invention has a compressive strength higher than the critical frost resistance strength of 3.5 MPa at an early age of 1 day. At a sub-zero temperature of -5℃, under the action of alkali activation, granulated blast furnace slag powder and metakaolin continue to react, continuously generating hydrated calcium silicate and hydrated calcium aluminosilicate gel, resulting in a continuous increase in compressive strength. As can be seen from the maximum core temperature of the low-thermal-disturbance grout suitable for frozen soil construction prepared in the above embodiments, the maximum temperature of the prepared low-thermal-disturbance grout suitable for frozen soil construction is below 0℃, which will not cause the frozen soil to melt, thus exhibiting low thermal disturbance.

[0076] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A low-thermal-disturbance grouting method suitable for construction in frozen soil, characterized in that, The raw materials, by mass parts, include: 20-30 parts of sulfoaluminate cement, 35-40 parts of granulated blast furnace slag powder, 20-22.5 parts of metakaolin, 15-17.5 parts of alkali activator with slow-release effect, 290-310 parts of fine aggregate, 30-35 parts of water, 3-4 parts of calcium nitrite, 0.4-0.6 parts of water-reducing agent, and 0.02-0.04 parts of triethanolamine.

2. The low-thermal-disturbance grouting method suitable for frozen soil construction according to claim 1, characterized in that, The sulfoaluminate cement used is 52.5 cement.

3. The low-thermal-disturbance grouting method suitable for frozen soil construction according to claim 1, characterized in that, The granulated blast furnace slag powder is of grade S95.

4. The low-thermal-disturbance grouting method suitable for frozen soil construction according to claim 1, characterized in that, The metakaolin clay has a mesh size of 600 or higher.

5. A low-thermal-disturbance grouting method suitable for frozen soil construction according to claim 1, characterized in that, The alkali activator is made from raw materials and sufficient deionized water. By weight percentage, the raw materials of the alkali activator include: 90%-92% anhydrous sodium silicate, 6.4%-8% hydroxypropyl methylcellulose, and 1.6%-2% gelatin.

6. A low-thermal-disturbance grouting method suitable for frozen soil construction according to claim 5, characterized in that, The preparation method of the alkaline activator includes: Deionized water is heated to 85-90℃, then hydroxypropyl methylcellulose and gelatin are added and stirred to disperse them evenly. Stirring continues, and the temperature is lowered to room temperature to obtain an aged and homogeneous solution. Anhydrous sodium silicate is added to the aged and homogeneous solution, and stirring is continued to ensure thorough mixing. The mixture is then dried by forced air drying to remove all moisture, yielding an alkali activator with a sustained-release effect.

7. A low-thermal-disturbance grouting method suitable for frozen soil construction according to claim 6, characterized in that, After adding hydroxypropyl methylcellulose and gelatin to water, the mixture is stirred at 120-130 r / min for 2-2.2 h to ensure uniform dispersion of the hydroxypropyl methylcellulose and gelatin. Then, the mixture is stirred at 65-75 r / min until the temperature is lowered to room temperature, resulting in an aged and homogeneous solution. Anhydrous sodium silicate is added to the aged and homogeneous solution, and the stirring speed is 120-130 r / min for 1.5-2 h. The mixture is then dried by forced air at a temperature of 38-42℃ for 24-36 h.

8. A low-thermal-disturbance grouting method suitable for frozen soil construction according to claim 1, characterized in that, The fine aggregate is made of quartz sand, and the fineness modulus of the quartz sand is 2.3-2.

5.

9. A low-thermal-disturbance grouting method suitable for frozen soil construction according to claim 1, characterized in that, The water-reducing agent used is a polycarboxylate water-reducing agent.

10. The method for preparing low-thermal disturbance grout suitable for frozen soil construction according to any one of claims 1-9, characterized in that, The process includes the following: Sulfoaluminate cement, granulated blast furnace slag powder, metakaolin, alkali activator and fine aggregate are mixed to obtain uniform raw materials; Calcium nitrite, water-reducing agent, triethanolamine and water are mixed to form a homogeneous solution; The raw materials and homogeneous solution are sealed and pre-cooled to obtain pre-cooled raw materials and pre-cooled homogeneous solution, with a pre-cooling temperature of -2~0℃. The pre-cooled raw materials and the pre-cooled homogeneous solution are mixed and stirred to form a homogeneous slurry, thus obtaining the low-heat disturbance grout suitable for frozen soil construction.