A compaction segment for solidifying slag soil from weathered granite residual soil and its manufacturing method

Abstract

This invention discloses a compacted segment of weathered granite residual soil with polymer solidification and its manufacturing method. The raw material composition and mass percentage of the segment are as follows: 5.26%-8.31% thermally activated modified weathered granite residual soil residue, 1.21%-2.86% sodium silicate, 4.26%-8.18% deionized water, and 80.98%-89.15% engineering waste soil. The segment is formed by uniformly mixing weathered granite residual soil with polymer slurry and engineering waste soil, followed by compaction and curing. When this segment is used to prepare precast concrete components, it can significantly reduce the amount of new concrete used in subsequent pours, thereby significantly reducing the amount of cement and natural sand and gravel required for preparing new concrete, resulting in high economic and environmental benefits.

Description

Technical Field

[0001] This invention relates to the resource utilization of engineering waste soil and precast concrete components, and particularly to a compacted waste soil solidification segment made of weathered granite residual soil and its manufacturing method. Background Technology

[0002] Precast concrete components have advantages such as fast construction speed, high product quality, and low labor demand on construction sites, and have been widely used in my country in recent years. However, conventional precast concrete components require a large amount of new concrete, resulting in high demand for cement and aggregates, which directly increases carbon emissions in the building materials industry.

[0003] In recent years, with the development of urbanization in my country, the amount of construction waste generated from foundation pit excavation, tunnel excavation, and dredging projects has been increasing. However, my country's capacity to dispose of construction waste is relatively low. Open-air stockpiling of untreated construction waste not only occupies a large amount of land but also poses a significant safety hazard due to landslides and other accidents. If construction waste could replace a portion of the new concrete needed for precast concrete components, it would greatly reduce the amount of cement and natural sand and gravel used, while also enabling the recycling of construction waste, resulting in significant environmental and economic benefits.

[0004] Chinese invention patent CN115627877B discloses a "steel-tube concrete column with built-in compacted cement-soil segments and its construction method." This patent document describes mixing cement and construction waste, filling the mixture into a pipe, and compacting it to form compacted cement-soil segments, which are used to replace new concrete in the preparation of steel-tube concrete columns. Although this compacted cement-soil segment can utilize construction waste and save on natural sand and gravel, its preparation still requires cement and pipe materials, resulting in high energy consumption, carbon emissions, and costs, making it unsuitable for engineering applications. Summary of the Invention

[0005] In view of this, the purpose of this invention is to propose a compaction segment for solidified slag soil from weathered granite residual soil and its manufacturing method, in order to solve the problems of high demand for cement and sand in conventional precast concrete components and the relatively low capacity of my country to dispose of engineering slag soil.

[0006] Based on the above objectives, the present invention provides a compacted section of weathered granite residual soil with polymer solidification, the raw material composition and mass percentage of which are: thermally activated modified weathered granite residual soil residue accounts for 5.26%-8.31%, sodium silicate accounts for 1.21%-2.86%, deionized water accounts for 4.26%-8.18%, and engineering waste soil accounts for 80.98%-89.15%.

[0007] The specific preparation method of the thermally activated modified weathered residual soil of granite is as follows:

[0008] S1. Add the residual soil from weathered granite to a ball mill and grind it at 40-60 rpm for 4-6 hours to obtain refined residual soil from weathered granite.

[0009] S2. Add nanocellulose to deionized water and stir for 30-50 min, then add ammonium persulfate, heat to 50-60℃ and stir for 2-4 h, then centrifuge, wash and dry to obtain carboxylated nanocellulose;

[0010] S3. Add polyvinyl alcohol, carboxylated nanocellulose and 3-methyl-15-phenylpentadecanoic acid to deionized water and stir for 30-50 min. Add catalyst, heat to 60-80℃ with stirring, react for 6-8 h, adjust pH to neutral, filter, wash and dry to obtain modified polyvinyl alcohol.

[0011] S4. Heat the refined weathered residual soil of granite obtained in step S1 to 700-900℃ at a rate of 5-15℃ / min, keep it at that temperature for 1-3 hours, and then cool it to room temperature to obtain thermally activated weathered residual soil of granite.

[0012] S5. Add the modified polyvinyl alcohol obtained in step S3 to deionized water and stir for 30-50 minutes. Add the thermally activated weathered residual soil of granite obtained in step S4 and stir for 3-5 hours to obtain thermally activated modified weathered residual soil of granite.

[0013] Preferably, the solidified slag compaction segment is cylindrical or prismatic in shape.

[0014] Preferably, the sodium silicate is sodium silicate with a modulus of 0.9-1.5.

[0015] Preferably, the engineering waste soil is waste soil with a particle size not exceeding 4.75mm excavated during underground engineering construction.

[0016] Preferably, the residual soil from the weathered granite in step S1 consists of particles with a diameter not exceeding 0.15 mm from the residual soil from the weathered granite excavated during underground engineering construction.

[0017] Preferably, in step S2, the weight ratio of nanocellulose, ammonium persulfate, and deionized water is 0.5-1:0.05-0.1:5-8.

[0018] Preferably, in step S3, the weight ratio of polyvinyl alcohol, carboxylated nanocellulose, 3-methyl-15-phenylpentadecanoic acid and deionized water is 0.8-1.2:0.4-0.6:0.4-0.6:3.2-7.2.

[0019] Preferably, the catalyst in step S3 refers to sulfuric acid with a concentration of 98%.

[0020] Preferably, in step S5, the modified polyvinyl alcohol, deionized water, and thermally activated weathered residual soil of granite are in a weight ratio of 0.25-0.8:1-2.4:5-8.

[0021] Furthermore, the present invention also provides a method for manufacturing the above-mentioned solidified slag compaction segment of weathered granite residual soil, comprising the following steps:

[0022] 1. Add sodium silicate to deionized water, then pour it into the residual mud of thermally activated modified granite weathered soil and stir for 20-30 minutes to obtain granite weathered soil polymer slurry.

[0023] 2. Add engineering waste soil to the granite weathered residual soil polymer slurry obtained in step 1, and stir for 20-30 minutes to obtain a loose waste soil slurry;

[0024] 3. Fill the loose slag slurry obtained in step 2 into a steel mold, and then place a steel pressure head on top of the slag slurry. Use the weight of the pressure head to compact the loose slag slurry. Then use a pressure device to compact the slag slurry in the mold. The pressure value is 65-75MPa, and the pressure is maintained for 10-30 minutes.

[0025] 4. Disassemble the steel mold, take out the compacted solidified soil segment, and place it in an environment with a temperature of 17-23℃ and a relative humidity of over 95% for 28 days to obtain a solidified soil segment of granite weathered residual soil.

[0026] The beneficial effects of this invention are:

[0027] 1. The segmental structure prepared by this invention exhibits rapid setting speed, excellent unconfined compressive strength, and high water stability. Through specific raw material combinations and preparation processes, such as the synergistic effect of components like thermally activated modified weathered residual soil from granite, it achieves high strength in a short time, quickly meeting the requirements of engineering construction schedules, enhancing the stability of building structures, and ensuring project quality.

[0028] 2. By making full use of construction waste as one of the main raw materials, the reliance on traditional cement and natural sand and gravel has been greatly reduced. Given the increasing amount of construction waste generated in my country and the insufficient capacity for disposal, this approach has achieved resource recycling, alleviated the pressure of resource shortage, and provided an effective way for sustainable development.

[0029] 3. This invention uses steel molds as preparation tools, which have high strength and allow for greater pressure to compact the slag slurry. This is beneficial to improving the strength of the solidified slag compaction segment. A certain pressure holding time is maintained during the compaction of the slag slurry until the slag slurry solidifies and hardens. Therefore, the solidified slag compaction segment has a certain strength after demolding and can be used alone without the need for pipes, thus reducing the cost of the segment. Attached Figure Description

[0030] Figure 1 This is a schematic diagram illustrating the fabrication of the compacted soil solidification segment of weathered granite residual soil according to the present invention. Detailed Implementation

[0031] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to specific embodiments.

[0032] Example 1: The specific preparation method of thermally activated modified weathered residual soil from granite is as follows:

[0033] S1. Add 1 kg of weathered residual soil from granite to a ball mill and grind at 40 rpm for 4 hours to obtain refined weathered residual soil from granite.

[0034] S2. Add 50g of nanocellulose to 500g of deionized water and stir for 30min. Then add 5g of ammonium persulfate, heat to 50℃ and stir for 2h. After centrifugation, washing and drying, carboxylated nanocellulose is obtained.

[0035] S3. Add 50g of polyvinyl alcohol, 25g of carboxylated nanocellulose and 25g of 3-methyl-15-phenylpentadecanoic acid to 200g of deionized water and stir for 30min. Add 1.5g of 98% sulfuric acid, heat to 60℃ with stirring, react for 6h, adjust the pH to neutral, filter, wash and dry to obtain modified polyvinyl alcohol.

[0036] S4. Heat 1 kg of refined granite weathered residual soil obtained in step S1 to 700°C at a rate of 5°C / min, keep it at that temperature for 1 hour, and then cool it to room temperature to obtain thermally activated granite weathered residual soil.

[0037] S5. Add 50g of modified polyvinyl alcohol obtained in step S3 to 50g of deionized water, stir for 30min, add 1Kg of thermally activated weathered residual soil from granite obtained in step S4, stir for 3h to obtain thermally activated modified weathered residual soil from granite.

[0038] The specific preparation process of a solidified slag compaction segment of weathered granite residual soil is as follows:

[0039] 1. Add 121g of sodium silicate to 443g of deionized water, then pour in 526g of thermally activated modified weathered residual soil from granite and stir for 20 minutes to obtain granite weathered residual soil polymer slurry.

[0040] 2. Add 8.91 kg of engineering waste soil to the granite weathered residual soil polymer slurry obtained in step 1, and stir for 20 min to obtain a loose waste soil slurry;

[0041] 3. The loose slag slurry obtained in step 2 is loaded into a steel mold, and a steel pressure head is placed on top of the slag slurry. The loose slag slurry is compacted by the weight of the pressure head. Then, a pressure device is used to compact the slag slurry in the mold. The pressure value is 65MPa, and the pressure is maintained for 10 minutes.

[0042] 4. Disassemble the steel mold, take out the compacted solidified soil segment, and place it in an environment with a temperature of 17℃ and a relative humidity of over 95% for 28 days to obtain a solidified soil segment of granite weathered residual soil.

[0043] Example 2: The specific preparation method of thermally activated modified weathered residual soil from granite is as follows:

[0044] S1. Add 1 kg of weathered residual soil from granite to a ball mill and grind at 50 rpm for 5 hours to obtain refined weathered residual soil from granite.

[0045] S2. Add 40g of nanocellulose to 346.5g of deionized water and stir for 40min. Then add 4g of ammonium persulfate, heat to 55℃ and stir for 3h. After centrifugation, washing and drying, carboxylated nanocellulose is obtained.

[0046] S3. Add 77g of polyvinyl alcohol, 38.5g of carboxylated nanocellulose and 38.5g of 3-methyl-15-phenylpentadecanoic acid to 385g of deionized water and stir for 40min. Add 2.3g of 98% sulfuric acid, heat to 70℃ with stirring, react for 7h, adjust pH to neutral, filter, wash and dry to obtain modified polyvinyl alcohol.

[0047] S4. Heat 1 kg of refined granite weathered residual soil obtained in step S1 to 800°C at a rate of 10°C / min, keep it at that temperature for 2 hours, and then cool it to room temperature to obtain thermally activated granite weathered residual soil.

[0048] S5. Add 77g of modified polyvinyl alcohol obtained in step S3 to 230g of deionized water, stir for 40 min, add 1Kg of thermally activated weathered residual soil from granite obtained in step S4, stir for 4 h to obtain thermally activated modified weathered residual soil from granite.

[0049] The specific preparation process of a solidified slag compaction segment of weathered granite residual soil is as follows:

[0050] 1. Add 200g of sodium silicate to 600g of deionized water, then pour in 700g of thermally activated modified weathered residual soil from granite and stir for 25 minutes to obtain granite weathered residual soil polymer slurry.

[0051] 2. Add 8.5 kg of engineering waste soil to the granite weathered residual soil polymer slurry obtained in step 1, and stir for 25 min to obtain a loose waste soil slurry;

[0052] 3. The loose slag slurry obtained in step 2 is loaded into a steel mold, and a steel pressure head is placed on top of the slag slurry. The loose slag slurry is compacted by the weight of the pressure head. Then, a pressure device is used to compact the slag slurry in the mold. The pressure value is 70 MPa, and the pressure is maintained for 20 minutes.

[0053] 4. Disassemble the steel mold, take out the compacted solidified soil segment, and place it in an environment with a temperature of 20℃ and a relative humidity of over 95% for 28 days to obtain a solidified soil segment of granite weathered residual soil.

[0054] Example 3: The specific preparation method of thermally activated modified weathered residual soil from granite is as follows:

[0055] S1. Add 1 kg of weathered residual soil from granite to a ball mill and grind at 60 rpm for 6 hours to obtain refined weathered residual soil from granite.

[0056] S2. Add 50g of nanocellulose to 400g of deionized water and stir for 50min. Then add 5g of ammonium persulfate, heat to 60℃ and stir for 4h. After centrifugation, washing and drying, carboxylated nanocellulose is obtained.

[0057] S3. Add 100g of polyvinyl alcohol, 50g of carboxylated nanocellulose and 50g of 3-methyl-15-phenylpentadecanoic acid to 600g of deionized water and stir for 50min. Add 3g of 98% sulfuric acid, heat to 80℃ with stirring, react for 8h, adjust the pH to neutral, filter, wash and dry to obtain modified polyvinyl alcohol.

[0058] S4. Heat 1 kg of refined granite weathered residual soil obtained in step S1 to 900°C at a rate of 15°C / min, keep it at that temperature for 3 hours, and then cool it to room temperature to obtain thermally activated granite weathered residual soil.

[0059] S5. Add 100g of modified polyvinyl alcohol obtained in step S3 to 250g of deionized water, stir for 50min, add 1Kg of thermally activated weathered residual soil from granite obtained in step S4, stir for 5h to obtain thermally activated modified weathered residual soil from granite.

[0060] The specific preparation process of a solidified slag compaction segment of weathered granite residual soil is as follows:

[0061] 1. Add 286g of sodium silicate to 783g of deionized water, then pour in 831g of thermally activated modified weathered residual soil from granite and stir for 30 minutes to obtain granite weathered residual soil polymer slurry.

[0062] 2. Add 8.1 kg of engineering waste soil to the granite weathered residual soil polymer slurry obtained in step 1, and stir for 30 min to obtain a loose waste soil slurry;

[0063] 3. The loose slag slurry obtained in step 2 is loaded into a steel mold, and a steel pressure head is placed on top of the slag slurry. The loose slag slurry is compacted by the weight of the pressure head. Then, a pressure device is used to compact the slag slurry in the mold. The pressure value is 75 MPa, and the pressure is maintained for 30 minutes.

[0064] 4. Disassemble the steel mold, take out the compacted solidified slag segment, and place it in an environment with a temperature of 23℃ and a relative humidity of over 95% for 28 days to obtain a solidified slag segment of granite weathered residual soil.

[0065] Comparative Example 1: The difference between Comparative Example 1 and Example 2 is that carboxylated nanocellulose is replaced with nanocellulose. The specific preparation process is as follows: The specific preparation method of thermally activated modified weathered residual soil of granite is as follows:

[0066] S1. Add 1 kg of weathered residual soil from granite to a ball mill and grind at 50 rpm for 5 hours to obtain refined weathered residual soil from granite.

[0067] S2. Heat 1 kg of refined granite weathered residual soil obtained in step S1 to 800°C at a rate of 10°C / min, keep it at that temperature for 2 hours, and then cool it to room temperature to obtain thermally activated granite weathered residual soil.

[0068] S3. Add 77g of polyvinyl alcohol and 38.5g of 3-methyl-15-phenylpentadecanoic acid to 385g of deionized water and stir for 40min. Add 2.3g of 98% sulfuric acid, heat to 70℃ with stirring, react for 7h, adjust pH to neutral, filter, wash and dry to obtain modified polyvinyl alcohol.

[0069] S4. Add 39g of modified polyvinyl alcohol and 39g of nanocellulose to 230g of deionized water, stir for 40min, add 1Kg of thermally activated weathered residual soil from granite obtained in step S2, stir for 4h to obtain thermally activated modified weathered residual soil from granite.

[0070] The specific preparation process of a solidified slag compaction segment of weathered granite residual soil is as follows:

[0071] 1. Add 200g of sodium silicate to 600g of deionized water, then pour in 700g of thermally activated modified weathered residual soil from granite and stir for 25 minutes to obtain granite weathered residual soil polymer slurry.

[0072] 2. Add 8.5 kg of engineering waste soil to the granite weathered residual soil polymer slurry obtained in step 1, and stir for 25 min to obtain a loose waste soil slurry;

[0073] 3. The loose slag slurry obtained in step 2 is loaded into a steel mold, and a steel pressure head is placed on top of the slag slurry. The loose slag slurry is compacted by the weight of the pressure head. Then, a pressure device is used to compact the slag slurry in the mold. The pressure value is 70 MPa, and the pressure is maintained for 20 minutes.

[0074] 4. Disassemble the steel mold, take out the compacted solidified soil segment, and place it in an environment with a temperature of 20℃ and a relative humidity of over 95% for 28 days to obtain a solidified soil segment of granite weathered residual soil.

[0075] Comparative Example 2: The difference between Comparative Example 2 and Example 2 is that polyvinyl alcohol is not added. The specific preparation process is as follows: The specific preparation method of thermally activated modified weathered residual soil of granite is as follows:

[0076] S1. Add 1 kg of weathered residual soil from granite to a ball mill and grind at 50 rpm for 5 hours to obtain refined weathered residual soil from granite.

[0077] S2. Heat 1 kg of refined granite weathered residual soil obtained in step S1 to 800°C at a rate of 10°C / min, keep it at that temperature for 2 hours, and then cool it to room temperature to obtain thermally activated granite weathered residual soil.

[0078] S3. Add 50g of nanocellulose to 400g of deionized water and stir for 50min. Then add 5g of ammonium persulfate, heat to 60℃ and stir for 4h. After centrifugation, washing and drying, carboxylated nanocellulose is obtained.

[0079] S4. Add 39g of carboxylated nanocellulose and 39g of 3-methyl-15-phenylpentadecanoic acid obtained in step S3 to 230g of deionized water, stir for 40min, add 1Kg of thermally activated weathered residual soil from granite obtained in step S2, stir for 4h to obtain thermally activated modified weathered residual soil from granite.

[0080] The specific preparation process of a solidified slag compaction segment of weathered granite residual soil is as follows:

[0081] 1. Add 200g of sodium silicate to 600g of deionized water, then pour in 700g of thermally activated modified weathered residual soil from granite and stir for 25 minutes to obtain granite weathered residual soil polymer slurry.

[0082] 2. Add 8.5 kg of engineering waste soil to the granite weathered residual soil polymer slurry obtained in step 1, and stir for 25 min to obtain a loose waste soil slurry;

[0083] 3. The loose slag slurry obtained in step 2 is loaded into a steel mold, and a steel pressure head is placed on top of the slag slurry. The loose slag slurry is compacted by the weight of the pressure head. Then, a pressure device is used to compact the slag slurry in the mold. The pressure value is 70 MPa, and the pressure is maintained for 20 minutes.

[0084] 4. Disassemble the steel mold, take out the compacted solidified soil segment, and place it in an environment with a temperature of 20℃ and a relative humidity of over 95% for 28 days to obtain a solidified soil segment of granite weathered residual soil.

[0085] Comparative Example 3: The difference between Comparative Example 3 and Example 2 is that 3-methyl-15-phenylpentadecanoic acid is not added. The specific preparation process is as follows: The specific preparation method of modified weathered residual soil from granite is as follows:

[0086] S1. Add 1 kg of weathered residual soil from granite to a ball mill and grind at 50 rpm for 5 hours to obtain refined weathered residual soil from granite.

[0087] S2. Add 40g of nanocellulose to 346.5g of deionized water and stir for 40min. Then add 4g of ammonium persulfate, heat to 55℃ and stir for 3h. After centrifugation, washing and drying, carboxylated nanocellulose is obtained.

[0088] S3. Add 77g of polyvinyl alcohol and 38.5g of carboxylated nanocellulose to 385g of deionized water and stir for 40min. Add 2.3g of 98% sulfuric acid, heat to 70℃ while stirring, react for 7h, adjust the pH to neutral, filter, wash and dry to obtain modified polyvinyl alcohol.

[0089] S4. Heat 1 kg of refined granite weathered residual soil obtained in step S1 to 800°C at a rate of 10°C / min, keep it at that temperature for 2 hours, and then cool it to room temperature to obtain thermally activated granite weathered residual soil.

[0090] S5. Add 77g of modified polyvinyl alcohol obtained in step S3 to 230g of deionized water, stir for 40 min, add 1Kg of thermally activated weathered residual soil from granite obtained in step S4, stir for 4 h to obtain thermally activated modified weathered residual soil from granite.

[0091] The specific preparation process of a solidified slag compaction segment of weathered granite residual soil is as follows:

[0092] 1. Add 200g of sodium silicate to 600g of deionized water, then pour in 700g of modified weathered residual soil from granite and stir for 25 minutes to obtain granite weathered residual soil polymer slurry.

[0093] 2. Add 8.5 kg of engineering waste soil to the granite weathered residual soil polymer slurry obtained in step 1, and stir for 25 min to obtain a loose waste soil slurry;

[0094] 3. The loose slag slurry obtained in step 2 is loaded into a steel mold, and a steel pressure head is placed on top of the slag slurry. The loose slag slurry is compacted by the weight of the pressure head. Then, a pressure device is used to compact the slag slurry in the mold. The pressure value is 70 MPa, and the pressure is maintained for 20 minutes.

[0095] 4. Disassemble the steel mold, take out the compacted solidified soil segment, and place it in an environment with a temperature of 20℃ and a relative humidity of over 95% for 28 days to obtain a solidified soil segment of granite weathered residual soil.

[0096] Comparative Example 4: The difference between Comparative Example 4 and Example 2 is that 3-methyl-15-phenylpentadecanoic acid is replaced with 3-methylhexadecanoic acid. The specific preparation process is as follows: The specific preparation method of thermally activated modified weathered residual soil of granite is as follows:

[0097] The specific preparation method of thermally activated modified weathered residual soil from granite is as follows:

[0098] S1. Add 1 kg of weathered residual soil from granite to a ball mill and grind at 50 rpm for 5 hours to obtain refined weathered residual soil from granite.

[0099] S2. Add 40g of nanocellulose to 346.5g of deionized water and stir for 40min. Then add 4g of ammonium persulfate, heat to 55℃ and stir for 3h. After centrifugation, washing and drying, carboxylated nanocellulose is obtained.

[0100] S3. Add 77g of polyvinyl alcohol, 38.5g of carboxylated nanocellulose and 38.5g of 3-methylhexadecanoic acid to 385g of deionized water and stir for 40min. Add 2.3g of 98% sulfuric acid, heat to 70℃ while stirring, react for 7h, adjust the pH to neutral, filter, wash and dry to obtain modified polyvinyl alcohol.

[0101] S4. Heat 1 kg of refined granite weathered residual soil obtained in step S1 to 800°C at a rate of 10°C / min, keep it at that temperature for 2 hours, and then cool it to room temperature to obtain thermally activated granite weathered residual soil.

[0102] S5. Add 77g of modified polyvinyl alcohol obtained in step S3 to 230g of deionized water, stir for 40 min, add 1Kg of thermally activated weathered residual soil from granite obtained in step S4, stir for 4 h to obtain thermally activated modified weathered residual soil from granite.

[0103] The specific preparation process of a solidified slag compaction segment of weathered granite residual soil is as follows:

[0104] 1. Add 200g of sodium silicate to 600g of deionized water, then pour in 700g of thermally activated modified weathered residual soil from granite and stir for 25 minutes to obtain granite weathered residual soil polymer slurry.

[0105] 2. Add 8.5 kg of engineering waste soil to the granite weathered residual soil polymer slurry obtained in step 1, and stir for 25 min to obtain a loose waste soil slurry;

[0106] 3. The loose slag slurry obtained in step 2 is loaded into a steel mold, and a steel pressure head is placed on top of the slag slurry. The loose slag slurry is compacted by the weight of the pressure head. Then, a pressure device is used to compact the slag slurry in the mold. The pressure value is 70 MPa, and the pressure is maintained for 20 minutes.

[0107] 4. Disassemble the steel mold, take out the compacted solidified soil segment, and place it in an environment with a temperature of 20℃ and a relative humidity of over 95% for 28 days to obtain a solidified soil segment of granite weathered residual soil.

[0108] Performance testing

[0109] 1. Final setting time test: The loose slag slurry prepared according to the raw material composition of Examples 1-3 and Comparative Examples 1-4 was poured into the test mold, the surface was smoothed, and a Vicat needle was inserted into the cement slurry. The time when the needle tip could not penetrate the cement slurry was the final setting time. Each group was tested three times and the average value was taken. The experimental data are shown in Table 1.

[0110] 2. Unconfined compressive strength test: A compacted segment of weathered residual granite soil polymer-solidified slag, prepared according to the raw material compositions of Examples 1-3 and Comparative Examples 1-4, was prepared into a cylinder with a height of 100 mm and a diameter of 100 mm in a standard mold and cured in a curing chamber at 20°C and 95% humidity for 28 days. After curing, the specimen was removed from the curing chamber, and its appearance was checked for integrity. The specimen was then placed at the center of the lower platen of a computer-controlled electronic universal testing machine. After adjusting the position, axial pressure was applied to the specimen at a loading rate of 1 mm / min until failure. The maximum load value at failure was recorded. The unconfined compressive strength was calculated according to the formula, where the strength equals the failure load divided by the cross-sectional area of ​​the specimen. The experimental data are shown in Table 1.

[0111] 3. Water stability coefficient test: A compacted section of weathered residual granite soil polymer solidified slag prepared according to the raw material composition of Examples 1-3 and Comparative Examples 1-4 was prepared into a cylinder with a height of 100 mm and a diameter of 100 mm in a standard mold. It was cured in a curing chamber at 20°C and 95% humidity for 28 days. After curing, the specimen was taken out of the curing chamber and the appearance of the specimen was checked for integrity. The cured specimen was completely immersed in water at room temperature for 24 hours. After immersion, the specimen was taken out, the surface moisture was wiped off, and the specimen was placed in the center of the lower platen of the microcomputer-controlled electronic universal testing machine. After adjusting the position, axial pressure was applied to the specimen at a loading rate of 1 mm / min until the specimen was broken. The unconfined compressive strength of each specimen was recorded. The water stability coefficient Cw was calculated according to the formula: Cw = Rw / Rd × 100%, where Rw is the compressive strength after immersion and Rd is the compressive strength tested in the unconfined compressive strength test. The experimental data are shown in Table 1.

[0112] Table 1 Experimental Results

[0113] Final setting time / min Unconfined compressive strength / MPa Water stability coefficient / % Example 1 40 35.8 97.03 Example 2 35 37.1 98.10 Example 3 37 36.7 97.65 Comparative Example 1 47 33.8 92.42 Comparative Example 2 51 29.7 94.14 Comparative Example 3 45 30.4 88.29 Comparative Example 4 44 31.7 93.58

[0114] Data analysis: As can be seen from Examples 1-3 in Table 1, the granite weathered residual soil polymer solidification compacted soil segments prepared by the preparation method of the present invention have rapid solidification ability and excellent unconfined compressive strength. At the same time, they can still maintain good stability when immersed in water for a long time and are not prone to collapse.

[0115] As can be seen from Example 2 and Comparative Example 1 in Table 1, the carboxylated nanocellulose used in this invention greatly helps to reduce setting time, improve unconfined compressive strength, and increase water stability. This may be because carboxylated nanocellulose can undergo esterification with polyvinyl alcohol and thus bond firmly together. During the curing process of the material, carboxylated nanocellulose can interact better with other components and accelerate the reaction process, while ordinary nanocellulose lacks this promoting effect, resulting in a slower reaction and an increased final setting time. In terms of improving unconfined compressive strength, carboxylated nanocellulose can combine with other components chemically to play a role, while ordinary nanocellulose can only participate through physical blending. The bonding force between nanocellulose and other components is not strong, and it cannot play a good role, resulting in a decrease in unconfined compressive strength. The chemical cross-linking structure formed by carboxylated nanocellulose and polyvinyl alcohol may also improve the strength and water resistance of the material to a certain extent. Ordinary nanocellulose cannot form such a cross-linking structure, resulting in poor water stability.

[0116] As can be seen from Example 2 and Comparative Example 2 in Table 1, the various properties of the segments were significantly affected when polyvinyl alcohol was not added. This may be because the lack of polyvinyl alcohol prevented the formation of a cross-linked structure with the thermally activated modified weathered residual soil of granite. At the same time, the carboxylated nanocellulose also lacked suitable grafting sites due to the lack of hydroxyl groups provided by polyvinyl alcohol, and could not be combined with the thermally activated modified weathered residual soil of granite through chemical methods. This resulted in a longer setting time and a decrease in unconfined compressive strength of the segments. Furthermore, polyvinyl alcohol can improve the reactivity of the material system and promote the chemical reaction between other components. When polyvinyl alcohol is lacking, the overall reaction rate decreases, resulting in poor curing effect of the material, which in turn affects water stability.

[0117] As can be seen from Example 2 and Comparative Example 3 in Table 1, the addition of 3-methyl-15-phenylpentadecanoic acid plays a beneficial role in the entire material system. This may be because the long chain structure of 3-methyl-15-phenylpentadecanoic acid itself can crosslink and entangle with materials such as polyvinyl alcohol, accelerating the curing process of the material. Furthermore, due to the presence of benzene rings, it can enhance the mechanical properties of the material as a rigid group. At the same time, the long chain structure is hydrophobic, which can reduce the absorption of water by the material, thereby improving the water resistance of the material.

[0118] As can be seen from Example 2 and Comparative Example 4 in Table 1, when the benzene ring structure is missing, the final setting time of the segment is prolonged, the unconfined compressive strength is reduced, and the water stability is worse. This may be because the benzene ring increases the chemical crosslinking sites and reactivity, accelerates the curing process of the material, and shortens the final setting time. The benzene ring structure can also improve the dispersibility of weathered residual soil of granite, making it more uniformly distributed in the material system and forming a denser microstructure. This dense structure helps to improve the overall strength of the material. The benzene ring structure is hydrophobic, which can reduce the absorption of water by the material. Although the long chain structure has a certain degree of hydrophobicity, it lacks the additional hydrophobic effect of the benzene ring, which leads to increased water absorption and reduced water stability.

[0119] Those skilled in the art should understand that the discussion of any of the above embodiments is merely exemplary and is not intended to imply that the scope of the invention is limited to these examples; within the framework of the invention, the technical features of the above embodiments or different embodiments can also be combined, the steps can be implemented in any order, and there are many other variations of the different aspects of the invention as described above, which are not provided in detail for the sake of brevity.

Claims

1. A compacted segment of a granite weathered residual soil aggregate solidified spoil, characterized in that The raw material composition and mass percentage of the segment are: hot-activated modified granite weathered residual soil mud 5.26%-8.31%, sodium silicate 1.21%-2.86%, deionized water 4.26%-8.18%, and engineering slag 80.98%-89.15%; The specific preparation method of the hot-activated modified granite weathered residual soil mud is as follows: S1. Put the granite weathered residual soil mud into a ball mill, grind at 40-60 rpm for 4-6 h, and obtain refined granite weathered residual soil mud; S2. Mix nano-cellulose, ammonium persulfate and deionized water, stir at 50-60℃ for 2-4 h, centrifuge, wash and dry to obtain carboxylated nano-cellulose; S3. Mix polyvinyl alcohol, carboxylated nano-cellulose, 3-methyl-15-phenyl pentadecanoic acid and deionized water, add catalyst, stir and heat to 60-80℃, react for 6-8 h, adjust the PH to neutral, filter, wash and dry to obtain modified polyvinyl alcohol; S4. Heat the refined granite weathered residual soil mud obtained in step S1 to 700-900℃ at a rate of 5-15℃ / min, keep warm for 1-3 h, then cool to room temperature to obtain hot-activated granite weathered residual soil mud; S5. Mix the modified polyvinyl alcohol obtained in step S3 and deionized water, stir for 30-50 min, add the hot-activated granite weathered residual soil mud obtained in step S4, and stir for 3-5 h to obtain hot-activated modified granite weathered residual soil mud.

2. The compacted segment of granite weathered residuum geopolymer stabilised spoil of claim 1, characterised in that, The shape of the solidified slag compaction segment is a cylinder or a prism.

3. A compacted segment of a granite weathered residuum geopolymer stabilised spoil according to claim 1, characterised in that, The sodium silicate is sodium silicate with a modulus of 0.9-1.

5.

4. A compacted segment of a granite weathered residuum geopolymer stabilised spoil according to claim 1 characterised in that, The engineering slag is waste soil with a particle size of not more than 4.75 mm excavated during underground engineering construction.

5. A compacted segment of a granite weathered residuum geopolymer stabilised spoil according to claim 1 characterised in that, The granite weathered residual soil mud in step S1 is a particle with a particle size of not more than 0.15 mm in the granite weathered residual soil excavated during underground engineering construction.

6. A compacted segment of a granite weathered residuum geopolymer stabilised spoil according to claim 1 characterised in that, The nano-cellulose, ammonium persulfate and deionized water in step S2 are in a weight ratio of 0.5-1:0.05-0.1:5-8.

7. A compacted segment of a granite weathered residuum geopolymer stabilised spoil according to claim 1 characterised in that, The polyvinyl alcohol, carboxylated nano-cellulose, 3-methyl-15-phenyl pentadecanoic acid and deionized water in step S3 are in a weight ratio of 0.8-1.2:0.4-0.6:0.4-0.6:3.2-7.2, and the catalyst refers to sulfuric acid with a concentration of 98%.

8. A compacted segment of a granite weathered residuum geopolymer stabilised spoil according to claim 1 characterised in that, The modified polyvinyl alcohol, deionized water and hot-activated granite weathered residual soil mud in step S5 are in a weight ratio of 0.25-0.8:1-2.4:5-8.

9. A method of producing a compacted segment of a granitic weathered residue aggregate stabilised material according to any one of claims 1 to 8, characterised in that, The method comprises the following steps:

1. Add sodium silicate to deionized water, then pour into hot-activated modified granite weathered residual soil mud and stir for 20-30 min to obtain granite weathered residual soil polymer neat paste; 2. Add engineering slag to the granite weathered residual soil polymer neat paste obtained in step 1, stir for 20-30 min to obtain loose state slag slurry; 3. The loose slurry obtained in step 2 is loaded into a steel mold, and a steel head is placed above the slurry, and the loose slurry is compacted by the weight of the head; then the slurry in the mold is compacted by using a pressure device, the pressure value is 65-75 MPa, and the pressure maintaining time is 10-30 min; 4. The steel mold is disassembled, and the compacted and solidified slurry segment is taken out and placed in an environment with a temperature of 17-23°C and a relative humidity of more than 95% for curing for 28 days, to obtain a compacted segment of a granite weathered residual soil polymer solidified slurry.

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