Solid waste-based soft soil curing agent and use method thereof

Abstract

The invention relates to the field of waste slurry treatment, in particular to a solid-waste-based soft soil curing agent and a preparation method thereof.The curing agent is prepared by mixing, by weight, 15-35 parts of cement, 25-50 parts of mineral powder, 15-35 parts of activated and regenerated micro powder, 10-20 parts of modified steel slag powder, 5-10 parts of desulfurized gypsum and 0.5-2 parts of alkali activator; the sum of the parts by weight of the components is 100 parts. The mineral powder and the power plant desulfurized gypsum are introduced into the curing agent, and the curing strength can be greatly improved under the synergistic effect of the mineral powder and the power plant desulfurized gypsum; the activated regenerated micro powder and the modified steel slag powder are doped, the active components participate in hydration to form strength, and the other components mainly play a role in filling micro aggregates, so that the porosity is reduced, the compactness is improved, the curing strength is improved, and the permeability coefficient is reduced; an alkaline environment provided by doping the alkali activator is beneficial to exciting the activity of the gelling component and quickly curing to form strength.

Description

Technical Field

[0001] This invention relates to the field of building materials technology, specifically to a solid waste-based soft soil solidifying agent and its preparation method. Background Technology

[0002] Soft soil is widely distributed in the Pearl River Delta region, and improper treatment of soft soil can lead to settlement and instability of the superstructure. Cement can effectively solidify sandy soil, but when used to solidify soft soil with high water content and high organic matter content, it is difficult to form dense and stable cementitious hydration products, resulting in low solidification strength. Simply increasing the amount of cement not only provides limited improvement in solidification strength but also leads to a waste of cement resources. This invention aims to develop a solid waste-based soft soil solidifying agent. This solidifying agent includes a large amount of solid waste and activated recycled micro-powder, which can reduce the amount of cement used, is environmentally friendly and low-cost, and can also effectively improve the reinforcement strength of soft soil. Summary of the Invention

[0003] In view of the shortcomings of the prior art, the purpose of this invention is to provide a solid waste-based soft soil solidifying agent and its application method, which has a good solidification effect on regional soft soil, and at the same time, the addition of a large amount of solid waste and activated regenerated micro powder is beneficial to the reuse of solid waste.

[0004] To achieve the above objectives, the present invention adopts the following technical solution: In a first aspect, the present invention provides a solid waste-based soft soil solidifying agent, wherein the solidifying agent is composed of the following raw materials in parts by weight: 15-35 parts cement, 20-40 parts mineral powder, 15-35 parts activated and regenerated micro powder, 15-30 parts modified steel slag powder, 3-10 parts desulfurized gypsum, and 0.5-2 parts sodium carbonate; the sum of the parts by weight of the above components is 100 parts.

[0005] As an improvement to the above scheme, the cement is silicate cement with a strength grade ≥42.5.

[0006] As an improvement to the above scheme, the mineral powder is not lower than grade S95.

[0007] As an improvement to the above scheme, the activated and regenerated micro powder is prepared by the following method: a. Mechanically crush waste concrete into small pieces; b. Grind the crushed waste concrete to a specific surface area > 250 m². 2 / kg, to obtain regenerated micro powder; c. The regenerated micro powder is calcined at 550-650℃ for 0.5-2 hours to obtain calcined regenerated micro powder; d. Mix the calcined regenerated micro powder with Ca(OH)2 and CaCl2 in a weight ratio of 1~2:0.03~0.08:0.01~0.05 for 3~5 minutes to obtain the activated regenerated micro powder.

[0008] As an improvement to the above scheme, the modified steel slag powder is prepared by the following method: a. Grind steel slag to a specific surface area > 400 m² 2 / kg, wherein the steel slag is grade II or higher steel slag powder; b. Mix the finely ground steel slag powder with water glass and NaOH with a modulus of 1 to 1.2 in a ratio of 1 to 2: 0.03 to 0.05: 0.03 to 0.05 for 3 to 5 minutes to obtain the modified steel slag powder.

[0009] As an improvement to the above scheme, the main component of the desulfurized gypsum is CaSO4•2H2O, and the content of the main component CaSO4•2H2O is ≥85wt%.

[0010] As an improvement to the above scheme, the sodium carbonate is a white powder with a purity of ≥99%.

[0011] This invention also provides a method for using the above-mentioned solid waste-based soft soil solidification agent, comprising the following steps: The solid waste-based soft soil solidification agent is mixed with water to form a slurry. Mix the slurry with the soft soil until homogeneous.

[0012] As an improvement to the above scheme, the weight ratio of the curing agent to water is 0.7~1.0.

[0013] As an improvement to the above scheme, the weight ratio of the slurry to the soft soil is 0.1 to 0.2, the water content of the soft soil is 50 to 60%, and the organic matter content is 5 to 8%.

[0014] The beneficial effects of this invention are: The curing agent of this invention incorporates activated and regenerated micro-powder, whose activity is enhanced through mechanical, thermal, and chemical activation methods, significantly increasing the content of active micro-particle components. A small amount of inactive micro-particles serve as micro-aggregate fillers. Modified steel slag powder is also incorporated, whose hydration activity is greatly improved through grinding and chemical activation. The remaining components primarily function as micro-aggregate fillers. Furthermore, mineral powder and power plant desulfurization gypsum are introduced into the curing agent, and their synergistic effect significantly improves the curing strength. The addition of sodium carbonate provides an alkaline environment, which is beneficial for activating the activity of the cementitious components and rapidly curing to achieve strength. Through the synergistic effect of these components, the solid waste-based soft soil curing agent of this invention can be obtained. Simultaneously, the mineral powder, activated and regenerated micro-powder, modified steel slag powder, and power plant desulfurization gypsum introduced into the formulation of this invention replace more than 60% of cement, realizing the reuse of solid waste materials, reducing waste, and lowering cement consumption. Detailed Implementation

[0015] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be described in further detail below. This invention can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a thorough and complete understanding of the disclosure of this invention.

[0016] Where specific techniques or conditions are not specified in the embodiments, they shall be performed in accordance with the techniques or conditions described in the literature in this field or in accordance with the product instructions. Raw materials whose manufacturers are not specified are all conventional products that can be obtained commercially.

[0017] The technical solution of the present invention will be further described below with reference to specific embodiments and comparative examples.

[0018] This invention provides a solid waste-based soft soil solidifying agent, which is composed of the following raw materials in parts by weight: 15-35 parts cement, 20-40 parts mineral powder, 15-35 parts activated and regenerated micro powder, 15-30 parts modified steel slag powder, 3-10 parts desulfurized gypsum, and 0.5-2 parts sodium carbonate; the sum of the parts by weight of the above components is 100 parts.

[0019] Cement is one of the components that contributes to the solidification strength. In this invention, the cement is ordinary Portland cement, and the cement strength grade can be greater than or equal to 42.5. Specifically, in the formulation of the solid waste-based soft soil solidification agent of this invention, the amount of cement is 15 to 35 parts, exemplarily 15 parts, 20 parts, 25 parts, or 30 parts, but not limited thereto.

[0020] As an improvement to the above scheme, the main component of the desulfurized gypsum is CaSO4•2H2O, and the content of the main component CaSO4•2H2O is ≥85wt%.

[0021] As an improvement to the above scheme, the alkaline activator is sodium carbonate.

[0022] Mineral powder is also an important component for the solidification strength of this invention. Under the dual stimulation of alkali and sulfate, it undergoes a significant pozzolanic reaction, generating a large amount of CSH gel and ettringite. This consumes the easily soluble and crystallizable Ca(OH)2 produced by cement hydration, increasing the stability of the gel and significantly improving the early and long-term strength of the solidified soil. Specifically, in the formulation of the solid waste-based soft soil solidification agent of this invention, the amount of mineral powder is 20-40 parts, exemplarily 25 parts, 28 parts, 30 parts, or 35 parts, but not limited to these.

[0023] Preferably, in the formulation of the present invention, the mineral powder is not lower than grade S95. The specific standard can be referred to the national standard "Granulated Blast Furnace Slag Powder for Cement, Mortar and Concrete" (GB / T 18046-2017) to have a high activity index, high fineness, improved workability, reduced heat of hydration, improved early strength and later strength, and thus improved durability.

[0024] The preparation method of activated regenerated micro powder is as follows: a. Mechanically crush waste concrete into small pieces; b. Grind the crushed waste concrete to a specific surface area > 250 m². 2 / kg, to obtain regenerated micro powder; c. calcine the regenerated micro powder at 550-650℃ for 0.5-2h to obtain calcined regenerated micro powder; d. mix the calcined regenerated micro powder with Ca(OH)2 and CaCl2 in a weight ratio of 1-2:0.03-0.08:0.01-0.05 for 3-5min to obtain the activated regenerated micro powder. It is prepared by sequential mechanical, thermal, and chemical activation methods, mainly serving as an active supplement and micro-aggregate. Unreacted C3S / C2S particles and activated components hydrate in an alkaline environment to form strength, while the remaining components act as micro-aggregate fillers. Specifically, in the formulation of the solid waste-based soft soil solidification agent of this invention, the amount of activated regenerated micro powder is 15-35 parts, exemplarily 20 parts, 25 parts, 30 parts, or 35 parts, but not limited to these.

[0025] The preparation method of modified steel slag powder is as follows: a. Grind the steel slag powder to a specific surface area > 400 m². 2 / kg, wherein the steel slag is grade II or higher steel slag powder; b. The finely ground steel slag powder is mixed with water glass and NaOH with a modulus of 1~1.2 in a ratio of 1~2:0.03~0.05:0.03~0.05 for 3~5 minutes to obtain the modified steel slag powder. The modified steel slag powder mainly acts as an auxiliary cementing material and micro-aggregate, providing an active iron-calcium phase, which hydrates in an alkaline environment to generate CSH gel, contributing strength, while the remaining microparticles fill the pores and reduce porosity. Specifically, in the formulation of the solid waste-based soft soil solidification agent of the present invention, the amount of modified steel slag powder is 15~30 parts, exemplarily 18 parts, 20 parts, 24 parts or 27 parts, but not limited thereto.

[0026] Among them, desulfurized gypsum provides SO4 2- This promotes the hydration of mineral powder to increase its strength, and simultaneously reacts with the aluminum phase in cement / modified steel slag powder and the active Al2O3 in mineral powder / activated regenerated micro powder to generate needle-like ettringite, which fills the pores and produces micro-expansion, enhancing compactness. Specifically, in the formulation of the solid waste-based soft soil solidification agent of this invention, the amount of desulfurized gypsum is 3 to 10 parts, exemplarily 4 parts, 6 parts, 8 parts or 9 parts, but not limited to these.

[0027] The incorporation of sodium carbonate creates an alkaline environment, further stimulating the pozzolanic activity of mineral powder, modified steel slag powder, and activated regenerated micro-powder. Simultaneously, it reacts with the calcium phase to generate calcium carbonate, filling pores, and with the aluminum phase to generate hydrated sodium aluminum carbonate (NASH gel), supplementing the cementitious network. Specifically, in the formulation of the solid waste-based soft soil solidifying agent of this invention, the amount of sodium carbonate is 0.5 to 2 parts, exemplarily 0.5 parts, 0.8 parts, 1 part, or 1.5 parts, but not limited to these.

[0028] This invention also provides a method for using the above-mentioned solid waste-based soft soil solidification agent, comprising the following steps: The solid waste-based soft soil solidifying agent is mixed with water to form a slurry, and then the slurry is mixed evenly with soft soil.

[0029] The weight ratio of the curing agent to water can be 0.7 to 1.0.

[0030] The weight ratio of the slurry to the soft soil can be 0.1 to 0.2, the water content of the soft soil is 50 to 60%, and the organic matter content is 5 to 8%.

[0031] The invention is described below with specific embodiments. The test soil was silt from a project in Sanshui District, Foshan City, at a depth of 2-5 meters. Testing showed its moisture content was 59% and organic matter content was 6.8%. A planetary mortar mixer was used for molding the solidified soil. First, the curing agent was mixed evenly at a water-cement ratio of 0.8 to prepare a slurry. Then, silt (15% of the silt mass) was added, and the mixture was slowly stirred for 2 minutes, then rapidly stirred for 2 minutes before being poured into molds. The unconfined compressive strength and permeability coefficient of the solidified soil were measured after 7 days and 28 days of standard curing. After 28 days, two groups of solidified soil were taken. One group was further cured to 180 days for unconfined compressive strength measurement, while the other group was immersed in a 5% sodium chloride solution for 180 days for unconfined compressive strength measurement, to evaluate the durability of the solidified soil in a chloride-salt environment.

[0032] Example 1 This embodiment provides a solid waste-based soft soil solidification agent, which is composed of the following raw materials in parts by weight: 32 parts of 42.5R silicate cement, 28 parts of S95 grade mineral powder, 17 parts of activated and recycled micro powder, 18 parts of modified steel slag powder, 4 parts of desulfurized gypsum, and 1 part of sodium carbonate.

[0033] The activated and regenerated micro powder is prepared by the following method: First, the waste concrete is mechanically crushed into small pieces. Then, the crushed waste concrete is ground in a ball mill until the specific surface area is greater than 250 m². 2 / kg, then the finely ground regenerated micro powder is placed in a resistance furnace at 600℃ and calcined for 1h. Finally, the calcined regenerated micro powder is mixed with Ca(OH)2 and CaCl2 in a ratio of 1:0.05:0.03 for 5min to obtain the activated regenerated micro powder.

[0034] The modified steel slag powder is prepared by the following method: The secondary steel slag was ground using a ball mill until its specific surface area was greater than 400 m². 2 / kg, then mix the finely ground steel slag powder with water glass and NaOH with a low modulus of 1 in a ratio of 1:0.05:0.05 for 5 minutes to obtain the modified steel slag powder.

[0035] Example 2 This embodiment provides a solid waste-based soft soil solidification agent, which is composed of the following raw materials in parts by weight: 25 parts of 42.5R silicate cement, 25 parts of S95 grade mineral powder, 25 parts of activated and recycled micro powder, 20 parts of modified steel slag powder, 4 parts of desulfurized gypsum, and 1 part of sodium carbonate.

[0036] The activated and regenerated micro powder is prepared by the following method: First, the waste concrete is mechanically crushed into small pieces. Then, the crushed waste concrete is ground in a ball mill until the specific surface area is greater than 250 m². 2 / kg, then the finely ground regenerated micro powder is placed in a resistance furnace at 600℃ and calcined for 1h. Finally, the calcined regenerated micro powder is mixed with Ca(OH)2 and CaCl2 in a ratio of 1:0.05:0.03 for 5min to obtain the activated regenerated micro powder.

[0037] The modified steel slag powder is prepared by the following method: The secondary steel slag was ground using a ball mill until its specific surface area was greater than 400 m². 2 / kg, then the finely ground steel slag powder is mixed with water glass and NaOH with a low modulus of 1 in a ratio of 1:0.05:0.05 for 5 minutes to obtain the modified steel slag powder.

[0038] Example 3 This embodiment provides a solid waste-based soft soil solidification agent, which is composed of the following raw materials in parts by weight: 20 parts of 42.5R silicate cement, 28 parts of S95 grade mineral powder, 23 parts of activated and recycled micro powder, 22 parts of modified steel slag powder, 5.5 parts of desulfurized gypsum, and 1.5 parts of sodium carbonate.

[0039] The activated and regenerated micro powder is prepared by the following method: First, the waste concrete is mechanically crushed into small pieces. Then, the crushed waste concrete is ground in a ball mill until the specific surface area is greater than 250 m². 2 / kg, then the finely ground regenerated micro powder is placed in a resistance furnace at 600℃ and calcined for 1h. Finally, the calcined regenerated micro powder is mixed with Ca(OH)2 and CaCl2 in a ratio of 1:0.05:0.03 for 5min to obtain the activated regenerated micro powder.

[0040] The modified steel slag powder is prepared by the following method: The secondary steel slag was ground using a ball mill until its specific surface area was greater than 400 m². 2 / kg, then the finely ground steel slag powder is mixed with water glass and NaOH with a low modulus of 1 in a ratio of 1:0.05:0.05 for 5 minutes to obtain the modified steel slag powder.

[0041] Example 4 This embodiment provides a solid waste-based soft soil solidification agent, which is composed of the following raw materials in parts by weight: 18 parts of 42.5R silicate cement, 28 parts of S95 grade mineral powder, 30 parts of activated and recycled micro powder, 17 parts of modified steel slag powder, 5.5 parts of desulfurized gypsum, and 1.5 parts of sodium carbonate.

[0042] The activated and regenerated micro powder is prepared by the following method: First, the waste concrete is mechanically crushed into small pieces. Then, the crushed waste concrete is ground in a ball mill until the specific surface area is greater than 250 m². 2 / kg, then the finely ground regenerated micro powder is placed in a resistance furnace at 600℃ and calcined for 1h. Finally, the calcined regenerated micro powder is mixed with Ca(OH)2 and CaCl2 in a ratio of 1:0.05:0.03 for 5min to obtain the activated regenerated micro powder.

[0043] The modified steel slag powder is prepared by the following method: The secondary steel slag was ground using a ball mill until its specific surface area was greater than 400 m². 2 / kg, then the finely ground steel slag powder is mixed with water glass and NaOH with a low modulus of 1 in a ratio of 1:0.05:0.05 for 5 minutes to obtain the modified steel slag powder.

[0044] Example 5 This embodiment provides a solid waste-based soft soil solidification agent, which is composed of the following raw materials in parts by weight: 18 parts of 42.5R silicate cement, 30 parts of S95 grade mineral powder, 20 parts of activated and recycled micro powder, 23 parts of modified steel slag powder, 7.5 parts of desulfurized gypsum, and 1.5 parts of sodium carbonate.

[0045] The activated and regenerated micro powder is prepared by the following method: First, the waste concrete is mechanically crushed into small pieces. Then, the crushed waste concrete is ground in a ball mill until the specific surface area is greater than 250 m². 2 / kg, then the finely ground regenerated micro powder is placed in a resistance furnace at 600℃ and calcined for 1h. Finally, the calcined regenerated micro powder is mixed with Ca(OH)2 and CaCl2 in a ratio of 1:0.05:0.03 for 5min to obtain the activated regenerated micro powder.

[0046] The modified steel slag powder is prepared by the following method: The secondary steel slag was ground using a ball mill until its specific surface area was greater than 400 m². 2 / kg, then the finely ground steel slag powder is mixed with water glass and NaOH with a low modulus of 1 in a ratio of 1:0.05:0.05 for 5 minutes to obtain the modified steel slag powder.

[0047] Comparative Example 1 This comparative example provides a soft soil solidifying agent, which is composed of the following raw materials in parts by weight: 32 parts of 42.5R silicate cement, 28 parts of S95 grade mineral powder, 17 parts of unactivated recycled micro powder, 18 parts of modified steel slag powder, 4 parts of desulfurized gypsum, and 1 part of sodium carbonate.

[0048] The regenerated micro powder used in the formula is unactivated regenerated micro powder, which is prepared by the following method: First, the waste concrete is mechanically crushed into small pieces. Then, the crushed waste concrete is ground in a ball mill until the specific surface area is greater than 250 m². 2 / kg, to obtain the unactivated regenerated micro powder.

[0049] The modified steel slag powder is prepared by the following method: The secondary steel slag was ground using a ball mill until its specific surface area was greater than 400 m². 2 / kg, then the finely ground steel slag powder is mixed with water glass and NaOH with a low modulus of 1 in a ratio of 1:0.05:0.05 for 5 minutes to obtain the modified steel slag powder.

[0050] Comparative Example 2 This comparative example provides a soft soil solidifying agent, which is composed of the following raw materials in parts by weight: 32 parts of 42.5R silicate cement, 28 parts of S95 grade mineral powder, 17 parts of activated and recycled micro powder, 18 parts of unmodified steel slag powder, 4 parts of desulfurized gypsum, and 1 part of sodium carbonate.

[0051] The activated and regenerated micro powder is prepared by the following method: First, the waste concrete is mechanically crushed into small pieces. Then, the crushed waste concrete is ground in a ball mill until the specific surface area is greater than 250 m². 2 / kg, then the finely ground regenerated micro powder is placed in a resistance furnace at 600℃ and calcined for 1h. Finally, the calcined regenerated micro powder is mixed with Ca(OH)2 and CaCl2 in a ratio of 1:0.05:0.03 for 5min to obtain the activated regenerated micro powder.

[0052] The unmodified steel slag powder is prepared by the following method: The secondary steel slag was ground using a ball mill until its specific surface area was greater than 400 m². 2 / kg, to obtain the unmodified steel slag powder.

[0053] Comparative Example 3 This comparative example provides a soft soil solidifying agent, which is composed of the following raw materials in parts by weight: 32 parts of 42.5R silicate cement, 29 parts of S95 grade mineral powder, 17 parts of activated and recycled micro powder, 18 parts of modified steel slag powder, and 4 parts of desulfurized gypsum.

[0054] The regenerated micro powder is an activated regenerated micro powder, prepared by the following method: First, the waste concrete is mechanically crushed into small pieces. Then, the crushed waste concrete is ground in a ball mill until the specific surface area is greater than 250 m². 2 / kg, then the finely ground regenerated micro powder is placed in a resistance furnace at 600℃ and calcined for 1h. Finally, the calcined regenerated micro powder is mixed with Ca(OH)2 and CaCl2 in a ratio of 1:0.05:0.03 for 5min to obtain the activated regenerated micro powder.

[0055] The modified steel slag powder is prepared by the following method: The secondary steel slag was ground using a ball mill until its specific surface area was greater than 400 m². 2 / kg, then the finely ground steel slag powder is mixed with water glass and NaOH with a low modulus of 1 in a ratio of 1:0.05:0.05 for 5 minutes to obtain the modified steel slag powder.

[0056] Comparative Example 4 This comparative example provides a soft soil solidifying agent, which is composed of the following raw materials in parts by weight: 32 parts of 42.5R silicate cement, 32 parts of S95 grade mineral powder, 17 parts of activated and recycled micro powder, 18 parts of modified steel slag powder, and 1 part of sodium carbonate.

[0057] The regenerated micro powder is an activated regenerated micro powder, prepared by the following method: First, the waste concrete is mechanically crushed into small pieces. Then, the crushed waste concrete is ground in a ball mill until the specific surface area is greater than 250 m². 2 / kg, then the finely ground regenerated micro powder is placed in a resistance furnace at 600℃ and calcined for 1h. Finally, the calcined regenerated micro powder is mixed with Ca(OH)2 and CaCl2 in a ratio of 1:0.05:0.03 for 5min to obtain the activated regenerated micro powder.

[0058] The modified steel slag powder is prepared by the following method: Steel slag is ground using a ball mill until its specific surface area is greater than 400 m². 2 / kg, then the finely ground steel slag powder is mixed with water glass and NaOH with a low modulus of 1 in a ratio of 1:0.05:0.05 for 5 minutes to obtain the modified steel slag powder.

[0059] The curing agents from the above embodiments and comparative examples were used for soft soil solidification. The specific application method is as follows: Weigh the silt and solidifying agent components according to the formula, and carry out mixing, molding, curing and unconfined compressive strength testing of the solidified soil according to the method specified in "Soft Soil Solidifying Agent" (CJ / T 526-2018). Test the permeability coefficient of the solidified soil according to the method specified in "Standard for Geotechnical Testing Methods" (GB / T50123-2019).

[0060] The specific results are shown in Table 1 below.

[0061] Table 1. Test results for each embodiment and comparative example.

[0062] Comparison of the results of each embodiment and comparative example shows that the incorporation of activated recycled micro powder, modified steel slag powder, desulfurized gypsum, and sodium carbonate has a superior solidification effect on silty soil, significantly improving the strength of solidified silty soft soil and its durability under chloride salt environments. The solid waste-based soft soil solidifiers provided in Examples 1-5 can replace more than 60% of cement and exhibit good solidification mechanical and durability properties for silty soft soil, making them highly suitable for the reinforcement of silty soft soil in coastal areas.

[0063] The technical features of the embodiments described above can be combined arbitrarily. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as the combination of these technical features does not contradict each other, it should be considered within the scope of this specification. It should be noted that those skilled in the art can make several modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this patent should be determined by the appended claims.

Claims

1. A solid waste-based soft soil stabilizing agent, characterized in that, The curing agent is composed of the following raw materials in parts by weight: 15-35 parts cement, 25-50 parts mineral powder, 15-35 parts activated and regenerated micro powder, 10-20 parts modified steel slag powder, 5-10 parts desulfurized gypsum, and 0.5-2 parts alkali activator; the sum of the parts by weight of the above components is 100 parts.

2. The solid waste-based soft soil solidification agent according to claim 1, characterized in that, The cement is silicate cement with a strength grade ≥42.

5.

3. The solid waste-based soft soil stabilizing agent according to claim 1, characterized in that, The mineral powder is of grade S95 or higher.

4. The solid waste-based soft soil solidifying agent according to claim 1, characterized in that, The activated and regenerated micro powder is prepared by the following method: a. Mechanically crush waste concrete into small pieces; b. Grind the crushed waste concrete to a specific surface area > 250 m². 2 / kg, to obtain regenerated micro powder; c. The regenerated micro powder is calcined at 550-650℃ for 0.5-2 hours to obtain calcined regenerated micro powder; d. Mix the calcined regenerated micro powder with Ca(OH)2 and CaCl2 in a weight ratio of 1~2:0.03~0.08:0.01~0.05 for 3~5 minutes to obtain the activated regenerated micro powder.

5. The solid waste-based soft soil solidification agent according to claim 1, characterized in that, The modified steel slag powder is prepared by the following method: a. Grind steel slag to a specific surface area > 400 m² 2 / kg, wherein the steel slag is grade II or higher steel slag powder; b. Mix the finely ground steel slag powder with water glass and NaOH with a modulus of 1 to 1.2 in a ratio of 1 to 2: 0.03 to 0.05: 0.03 to 0.05 for 3 to 5 minutes to obtain the modified steel slag powder.

6. The solid waste-based soft soil solidifying agent according to claim 1, characterized in that, The main component of the desulfurized gypsum is CaSO4•2H2O, and the content of the main component CaSO4•2H2O is ≥85wt%.

7. The solid waste-based soft soil solidifying agent according to claim 1, characterized in that, The alkaline activator is sodium carbonate.

8. The method of using the solid waste-based soft soil solidification agent as described in any one of claims 1-7, characterized in that, Including the following steps: The solid waste-based soft soil solidification agent is mixed with water to form a slurry. Mix the slurry with the soft soil until homogeneous.

9. The method of use according to claim 8, characterized in that, The weight ratio of the curing agent to water is 0.7 to 1.

0.

10. The method of use according to claim 9, characterized in that, The weight ratio of the slurry to the soft soil is 0.1 to 0.2, the water content of the soft soil is 50 to 60%, and the organic matter content is 5 to 8%.

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