Solidified soil prepared from solid waste and preparation method thereof

Abstract

The invention discloses a solidified soil prepared from solid waste and a preparation method thereof, and relates to the technical field of building engineering materials. The solidified soil prepared from solid waste of the invention is added with a self-made anti-dispersant and a composite curing agent, wherein the self-made anti-dispersant is prepared by introducing graphene oxide on the surface of pretreated aramid fiber and then in-situ generating nano-silicon dioxide on the surface, and then entering into the solidified soil component to reduce dispersion, thereby maintaining the strength of the solidified soil; the composite curing agent includes modified glass fiber reinforced plastics, sulphoaluminate cement, silicate cement and gypsum powder, wherein the modified glass fiber reinforced plastics are prepared by carboxylating the glass fiber reinforced plastics and coating the mercapto cross-linked polymer, and then entering into the structure of the solidified soil to prevent shrinkage and deformation, and enhance the curing strength.

Description

Technical Field

[0001] The invention relates to the technical field of building engineering materials, in particular to solidified soil prepared from solid waste and a preparation method thereof. Background Art

[0002] my country's urban construction is in a stage of rapid development, among which road backfilling is a problem that often needs to be faced, such as backfilling after trenching of urban roadbed for pipeline burial, backfilling around inspection wells, backfilling of road excavation, etc. The traditional road backfilling method treats the excavated slag as construction waste, and then backfills with a large amount of external backfill materials such as slag powder and fine silt sand. This will not only produce a large amount of solid waste, increase the pressure of transportation, and affect construction efficiency, but also require the purchase of a large amount of backfill materials, resulting in high economic costs. Weathered material refers to a material formed by rock under weathering. The weathering action causes the rock to break and change its composition, and the particle size, shape and composition of the weathered material produced are different. In the fields of construction engineering, weathered materials can be used as building materials if they are properly handled. For example, weathered sand and other weathered materials are used as roadbed materials in some highway construction.

[0003] However, unlike the terrestrial environment, underwater, the slurry formed during the preparation of fluidized solidified soil is easily lost due to water erosion, and the dispersion of the slurry will affect the strength performance of the fluidized solidified soil, and it is also very easy to pollute the water environment, thus limiting the wide application of solidified soil. Therefore, the present invention uses solid waste and weathered materials to prepare high-strength solidified soil, which can not only utilize waste, but also solve the problem of using solidified soil. Summary of the invention

[0004] The technical problem to be solved by the present invention is to provide a solidified soil prepared from solid waste and a preparation method thereof.

[0005] The present invention proposes a technical solution to solve the above technical problems: a solidified soil prepared from solid waste, comprising solid waste, weathered material, water, cement, fly ash, a homemade anti-dispersion agent and a composite curing agent; the homemade anti-dispersion agent is prepared by introducing graphene oxide onto the surface of pretreated aramid fiber and then generating nano-silicon dioxide in situ on the surface; the aramid fiber is chopped aramid fiber.

[0006] Preferably, the composite curing agent comprises modified glass fiber reinforced plastics, sulphoaluminate cement, silicate cement and gypsum powder; the modified glass fiber reinforced plastics are obtained by carboxylating glass fiber reinforced plastics and then coating them with a mercapto cross-linked polymer; the glass fiber reinforced plastics are glass fiber reinforced plastic powder.

[0007] Preferably, the solid waste includes any one of waste cement, waste mortar, waste concrete, stone powder, waste ceramic bricks or industrial tailings, or a combination of at least two of them.

[0008] Preferably, the cement is at least one of Portland cement, ordinary Portland cement, slag Portland cement, pozzolanic Portland cement, fly ash Portland cement or composite Portland cement.

[0009] Preferably, the method for preparing solidified soil prepared from solid waste comprises the following specific steps:

[0010] S1. The pretreated aramid fiber, hydroxypolyvinyl pyrrolidone and chloroform were mixed in a mass ratio of 8:1-3:50, heated to 80-90°C, and concentrated sulfuric acid was added in an amount of 0.1-0.2 times the mass of hydroxypolyvinyl pyrrolidone, and the reaction was continued for 6-8 hours. Graphene oxide was added in an amount of 0.2-0.4 times the mass of hydroxypolyvinyl pyrrolidone, and the reaction was continued for 2-4 hours. The mixture was cooled to room temperature, filtered, and transferred to a mixture of ethyl orthosilicate in an amount of 20-30 times the mass of hydroxypolyvinyl pyrrolidone. The mass ratio of ethyl orthosilicate, anhydrous ethanol and deionized water in the ethyl orthosilicate mixture was 0. .8~1.2:7:3, after shaking for 3~5 minutes, adjust the pH to 2~3 with hydrochloric acid, heat to 40~45℃, react for 1~2 hours, cool to room temperature, adjust the pH to 6.8~7.2 with ammonia water, let stand for 5~8 minutes after gelation, add 4~8 times the mass of hydroxy polyvinyl pyrrolidone of tetraethyl orthosilicate and 10~20 times the mass of hydroxy polyvinyl pyrrolidone of anhydrous ethanol, stir evenly and age at room temperature for 12~14 hours, place at 80~90℃ to dry for 3~4 hours, heat to 120~130℃ to dry for 5~6 hours, and prepare the homemade anti-dispersion agent;

[0011] S2. Carboxylated FRP, mercapto cross-linked polymer and anhydrous ethanol are mixed in a mass ratio of 3-5:1:30-50, stirred evenly and heated to 80-90°C, and 0.02-0.04 times the mass of carboxylated FRP sodium hydroxide is added, reacted for 6-8 hours, filtered and washed with deionized water for 3-5 times, and dried to obtain modified FRP;

[0012] S3. The modified glass fiber reinforced plastic, sulphoaluminate cement, silicate cement and gypsum powder were mixed in a mass ratio of 1:20~40:20:4~8 and stirred to obtain a composite curing agent;

[0013] S4. Crush the solid waste and weathered materials, remove foreign matter and polluted and deteriorated parts in the solid waste, add water, cement, fly ash, retarder, homemade anti-dispersion agent and composite curing agent, stir evenly, and obtain solidified soil prepared from solid waste.

[0014] Preferably, in the above step S1, the process of pretreating the aramid fiber is: placing the aramid fiber in a 60-80kHz ultrasonic cleaning for 8-10 minutes, drying it and immersing it in a lithium chloride solution with a mass fraction of 7-10%, heating it to 76-78°C, reacting it for 3-4 hours, taking it out and washing it with deionized water and anhydrous ethanol for 3-5 times in sequence, and drying it to obtain the pretreated aramid fiber.

[0015] Preferably, in the above step S1, the preparation method of hydroxypolyvinyl pyrrolidone is: under a nitrogen atmosphere, isopropanol, thioglycerol, N-vinyl pyrrolidone and azobisisobutyronitrile are mixed in a mass ratio of 5:10~20:1:0.02~0.04, stirred evenly and heated to 78~82°C, reacted for 24 hours, cooled to room temperature and rotary evaporated, washed with ether 3~5 times, filtered under reduced pressure, dissolved in chloroform, precipitated with ether, and finally dried to obtain hydroxypolyvinyl pyrrolidone.

[0016] Preferably, in the above step S2, the preparation method of the carboxylated glass fiber reinforced plastic is: deionized water, tetrabutylammonium iodide and glass fiber reinforced plastic are mixed in a mass ratio of 100:0.4~0.6:6~8, the temperature is raised to 70~72°C, a 2 mol / L sodium hydroxide solution of 4~8 times the mass of the glass fiber reinforced plastic is added, the reaction is stirred at 60~80rpm for 3~5h, the mixture is filtered and washed with hydrochloric acid until the pH value is 1.8~2.2, then washed with deionized water for 8~10 times, and finally dried at 80~90°C to obtain the carboxylated glass fiber reinforced plastic.

[0017] Preferably, in the above step S2, the preparation method of the thiol cross-linked polymer is: under a nitrogen atmosphere, dibenzyl disulfide, biphenyl dichlorobenzyl and 1,2-dichloromethane are mixed in a mass ratio of 0.03-0.05:10:4, the temperature is raised to 40-42°C, and after stirring evenly, ferric chloride is added in an amount of 2.2-2.4 times the mass of dibenzyl disulfide, the temperature is raised to 60-80°C, and the reaction is carried out for 24 hours, and Soxhlet extraction is carried out with methanol, and the pH is adjusted to 4.8-5.2 with a mass fraction of 1-3% tris(2-carboxyethyl)phosphine hydrochloride solution, and ethanol is added in an amount of 0.02-0.04 times the mass of dibenzyl disulfide. After reacting for 1-2 hours, the mixture is filtered and dried to obtain a thiol cross-linked polymer.

[0018] Preferably, in the above step S4, the mass ratio of solid waste, water, cement, fly ash, homemade anti-dispersion agent and composite curing agent is 15~20:5~10:8~10:1~3:0.3~0.6:0.2~0.6:1~3.

[0019] Compared with the prior art, the beneficial effects achieved by the present invention are:

[0020] The solidified soil prepared from solid waste of the present invention is added with a self-made anti-dispersion agent and a composite solidifying agent;

[0021] The self-made anti-dispersion agent is prepared by introducing graphene oxide on the surface of pretreated aramid fiber and then generating nano-silicon dioxide in situ on the surface; the hydrogen bonds between the molecular chains of the pretreated aramid fiber are destroyed, and then hydroxyl polyvinyl pyrrolidone is coated on the surface, and the hydroxyl groups on the fiber surface react with the surface active groups of graphene oxide, and graphene oxide with a two-dimensional nano-layered structure is introduced on the surface of the aramid fiber, and then nano-silicon dioxide is generated in situ on the surface, forming an aerogel with a rough surface and adsorption capacity, which can absorb free water, promote the hydration reaction between the components in the solidified soil, enter the solidified soil components, reduce dispersion, and thus maintain the strength of the solidified soil;

[0022] The composite curing agent includes modified glass fiber reinforced plastics, sulphoaluminate cement, silicate cement and gypsum powder. The modified glass fiber reinforced plastics are prepared by carboxylating the glass fiber reinforced plastics and then coating them with a thiol cross-linked polymer. The thiol cross-linked polymer is coated on the glass fiber reinforced plastic powder to form a cross-linked network structure on the surface, so that the composite curing agent forms a through curing network during the curing process, enters into the structure of the cured soil, prevents shrinkage and deformation, and enhances the curing strength. DETAILED DESCRIPTION

[0023] The present invention is described in detail below by way of examples. It is necessary to point out that the following examples are only used to further illustrate the present invention and cannot be understood as limiting the scope of protection of the present invention. Those skilled in the art can make some non-essential improvements and adjustments to the present invention based on the above content of the present invention. Unless otherwise defined, all professional and scientific terms used herein have the same meanings as those familiar to those skilled in the art.

[0024] In order to more clearly illustrate the method provided by the present invention, the following examples are used to describe in detail the various index testing methods of the solidified soil prepared from the solid waste prepared in the examples and comparative examples as follows:

[0025] Anti-dispersion: The loss of the solidified soil prepared from the solid wastes of the examples and comparative examples was measured with reference to DL / T5117.

[0026] Compressive strength: The unconfined compressive strength of the solidified soil prepared from the solid wastes in the examples and comparative examples was measured with reference to GB / T50123 after curing for 7 days, 14 days and 28 days.

[0027] Example 1: The method for preparing solidified soil from solid waste in this example is as follows:

[0028] S1. The aramid fiber was placed in a 60kHz ultrasonic cleaning for 8 minutes, and then immersed in a 7% lithium chloride solution after drying, heated to 76°C, reacted for 3 hours, taken out and washed three times with deionized water and anhydrous ethanol in turn, and dried to obtain the pretreated aramid fiber; in a nitrogen atmosphere, isopropanol, thioglycerol, N-vinyl pyrrolidone and azobisisobutyronitrile were mixed in a mass ratio of 5:10:1:0.02, stirred evenly and heated to 78°C, reacted for 24 hours, cooled to room temperature and rotary evaporated, washed three times with ether, filtered under reduced pressure, dissolved in chloroform, precipitated with ether, and finally dried to obtain hydroxypolyvinyl pyrrolidone; the pretreated aramid fiber, hydroxypolyvinyl pyrrolidone and chloroform were mixed in a mass ratio of 8:1:50, heated to 80°C, and hydroxypolyvinyl pyrrolidone was added. 0.1 times the mass of hydroxypolyvinyl pyrrolidone concentrated sulfuric acid, react for 6 hours, add 0.2 times the mass of hydroxypolyvinyl pyrrolidone graphene oxide, continue to react for 2 hours, cool to room temperature, filter, transfer to a mixture of ethyl orthosilicate with 20 times the mass of hydroxypolyvinyl pyrrolidone, the mass ratio of ethyl orthosilicate, anhydrous ethanol and deionized water in the ethyl orthosilicate mixture is 0.8:7:3, shake for 3 minutes, adjust the pH to 2 with hydrochloric acid, heat to 40°C, react for 1 hour, cool to room temperature, adjust the pH to 6.8 with ammonia water, stand for 5 minutes after gelation, add 4 times the mass of hydroxypolyvinyl pyrrolidone ethyl orthosilicate and 10 times the mass of hydroxypolyvinyl pyrrolidone anhydrous ethanol, stir evenly, age at room temperature for 12 hours, dry at 80°C for 3 hours, heat to 120°C and dry for 5 hours to obtain a homemade anti-dispersion agent;

[0029] S2. Deionized water, tetrabutylammonium iodide and FRP were mixed in a mass ratio of 100:0.4:6, heated to 70°C, 2 mol / L sodium hydroxide solution of 4 times the mass of FRP was added, stirred at 60rpm for 3h, filtered and washed with hydrochloric acid to pH 1.8, then washed with deionized water 8 times, and finally dried at 80°C to obtain carboxylated FRP; dibenzyl disulfide, biphenyl dichlorobenzyl and 1,2-dichloromethane were mixed in a mass ratio of 0.03:10:4 under a nitrogen atmosphere, heated to 40°C, stirred evenly, and 2.2 times the mass of dibenzyl disulfide was added. Ferric chloride, heated to 60°C, reacted for 24 hours, extracted with methanol for Soxhlet extraction, adjusted the pH to 4.8 with 1% tri(2-carboxyethyl)phosphine hydrochloride solution, added ethanol with a mass fraction of 0.02 times that of dibenzyl disulfide, reacted for 1 hour, filtered and dried to obtain a thiol cross-linked polymer; carboxylated FRP, thiol cross-linked polymer and anhydrous ethanol were mixed in a mass ratio of 3:1:30, stirred evenly, heated to 80°C, added sodium hydroxide with a mass fraction of 0.02 times that of carboxylated FRP, reacted for 6 hours, filtered and washed 3 times with deionized water, dried to obtain a modified FRP;

[0030] S3. The modified glass fiber reinforced plastic, sulphoaluminate cement, silicate cement and gypsum powder were mixed in a mass ratio of 1:20:20:4 and stirred to obtain a composite curing agent;

[0031] S4. Crush the solid waste and weathered materials and remove foreign matter and contaminated and deteriorated parts in the solid waste, add water, cement, fly ash, retarder, homemade anti-dispersion agent and composite curing agent, the mass ratio of solid waste, weathered materials, water, cement, fly ash, homemade anti-dispersion agent and composite curing agent is 15:5:8:1:0.3:0.2:1, stir evenly to obtain solidified soil prepared from solid waste.

[0032] Example 2: The method for preparing solidified soil from solid waste in this example is as follows:

[0033] S1. The aramid fiber was placed in a 70kHz ultrasonic cleaning for 9 minutes, and after drying, it was immersed in a lithium chloride solution with a mass fraction of 7-10%, heated to 77°C, reacted for 3.5 hours, taken out and washed with deionized water and anhydrous ethanol four times in sequence, and dried to obtain the pretreated aramid fiber; in a nitrogen atmosphere, isopropanol, thioglycerol, N-vinyl pyrrolidone and azobisisobutyronitrile were mixed in a mass ratio of 5:15:1:0.03, stirred evenly and heated to 80°C, reacted for 24 hours, cooled to room temperature and rotary evaporated, washed with ether four times, filtered under reduced pressure, dissolved in chloroform, precipitated with ether, and finally dried to obtain hydroxypolyvinylpyrrolidone; the pretreated aramid fiber, hydroxypolyvinylpyrrolidone and chloroform were mixed in a mass ratio of 8:2:50, heated to 85°C, and hydroxypolyvinylpyrrolidone was added. 0.15 times the mass of concentrated sulfuric acid, react for 7 hours, add 0.3 times the mass of hydroxypolyvinyl pyrrolidone graphene oxide, continue to react for 3 hours, cool to room temperature, filter, transfer to a mixture of 25 times the mass of hydroxypolyvinyl pyrrolidone with tetraethyl orthosilicate, the mass ratio of tetraethyl orthosilicate, anhydrous ethanol and deionized water in the tetraethyl orthosilicate mixture is 1:7:3, shake for 4 minutes, adjust the pH to 2.5 with hydrochloric acid, heat to 43°C, react for 1.5 hours, cool to room temperature, adjust the pH to 7.0 with ammonia water, stand for 7 minutes after gelation, add 6 times the mass of hydroxypolyvinyl pyrrolidone with tetraethyl orthosilicate and 15 times the mass of hydroxypolyvinyl pyrrolidone with anhydrous ethanol, stir evenly, age at room temperature for 13 hours, dry at 85°C for 3.5 hours, heat to 125°C and dry for 5.5 hours to obtain a homemade anti-dispersion agent;

[0034] S2. Deionized water, tetrabutylammonium iodide and FRP were mixed in a mass ratio of 100:0.5:7, heated to 71°C, 4 to 8 times the mass of FRP was added with a 2 mol / L sodium hydroxide solution, stirred at 70 rpm for 3 to 5 hours, filtered and washed with hydrochloric acid until the pH value was 2.0, then washed with deionized water for 9 times, and finally dried at 85°C to obtain carboxylated FRP; in a nitrogen atmosphere, dibenzyl disulfide, biphenyl dichlorobenzyl and 1,2-dichloromethane were mixed in a mass ratio of 0.04:10:4, heated to 41°C, stirred evenly, and 2.3 times the mass of dibenzyl disulfide was added. The mixture was heated to 70°C, reacted for 24 hours, extracted with methanol, adjusted to pH 5.0 with 2% tri(2-carboxyethyl)phosphine hydrochloride solution, added with ethanol in an amount of 0.03 times the mass of dibenzyl disulfide, reacted for 1.5 hours, filtered and dried to obtain a thiol cross-linked polymer; carboxylated FRP, thiol cross-linked polymer and anhydrous ethanol were mixed in a mass ratio of 4:1:40, stirred evenly, heated to 85°C, added with sodium hydroxide in an amount of 0.03 times the mass of carboxylated FRP, reacted for 7 hours, filtered and washed with deionized water 4 times, dried to obtain a modified FRP;

[0035] S3. The modified glass fiber reinforced plastic, sulphoaluminate cement, silicate cement and gypsum powder were mixed in a mass ratio of 1:30:20:6 and stirred to obtain a composite curing agent;

[0036] S4. Crush the solid waste and weathered materials and remove foreign matter and contaminated and deteriorated parts in the solid waste, add water, cement, fly ash, retarder, homemade anti-dispersion agent and composite curing agent, the mass ratio of solid waste, weathered materials, water, cement, fly ash, homemade anti-dispersion agent and composite curing agent is 18:8:9:2:0.5:0.4:2, stir evenly to obtain solidified soil prepared from solid waste.

[0037] Embodiment 3: The method for preparing solidified soil from solid waste in this embodiment is as follows:

[0038] S1. The aramid fiber was placed in an 80kHz ultrasonic cleaning for 10 minutes, and after drying, it was immersed in a 10% lithium chloride solution by mass fraction, heated to 78°C, reacted for 4 hours, taken out and washed with deionized water and anhydrous ethanol for 5 times in sequence, and dried to obtain the pretreated aramid fiber; in a nitrogen atmosphere, isopropanol, thioglycerol, N-vinyl pyrrolidone and azobisisobutyronitrile were mixed in a mass ratio of 5:20:1:0.04, stirred evenly and heated to 82°C, reacted for 24 hours, cooled to room temperature and rotary evaporated, washed with ether for 5 times, filtered under reduced pressure, dissolved in chloroform, precipitated with ether, and finally dried to obtain hydroxypolyvinyl pyrrolidone; the pretreated aramid fiber, hydroxypolyvinyl pyrrolidone and chloroform were mixed in a mass ratio of 8:3:50, heated to 90°C, and hydroxypolyvinyl pyrrolidone was added. The mixture was stirred for 5 minutes, and the pH value was adjusted to 3 with hydrochloric acid, and the mixture was heated to 45°C for 2 hours. The mixture was cooled to room temperature, and the pH value was adjusted to 7.2 with ammonia water. After gelation, the mixture was allowed to stand for 8 minutes. 8 times the mass of hydroxypolyvinyl pyrrolidone of ethyl orthosilicate and 20 times the mass of hydroxypolyvinyl pyrrolidone of ethyl orthosilicate were added. After stirring, the mixture was aged at room temperature for 14 hours, dried at 90°C for 4 hours, and dried at 130°C for 6 hours to obtain a self-made anti-dispersant.

[0039] S2. Deionized water, tetrabutylammonium iodide and FRP were mixed in a mass ratio of 100:0.6:8, heated to 72°C, 2 mol / L sodium hydroxide solution (8 times the mass of FRP) was added, stirred at 80 rpm for 5 h, filtered and washed with hydrochloric acid until the pH value was 2.2, then washed with deionized water for 8 to 10 times, and finally dried at 90°C to obtain carboxylated FRP; dibenzyl disulfide, biphenyl dichlorobenzyl and 1,2-dichloromethane were mixed in a mass ratio of 0.05:10:4 under a nitrogen atmosphere, heated to 42°C, stirred evenly, and 2.4% dibenzyl disulfide was added. times of ferric chloride, heated to 80°C, reacted for 24 hours, extracted with methanol for Soxhlet extraction, adjusted the pH to 5.2 with a 3% tri(2-carboxyethyl)phosphine hydrochloride solution, added ethanol with a mass fraction of 0.04 times of dibenzyl disulfide, reacted for 2 hours, filtered and dried to obtain a thiol cross-linked polymer; carboxylated FRP, thiol cross-linked polymer and anhydrous ethanol were mixed in a mass ratio of 5:1:50, stirred evenly, heated to 90°C, added sodium hydroxide with a mass fraction of 0.04 times of the carboxylated FRP, reacted for 8 hours, filtered and washed with deionized water 5 times, and dried to obtain a modified FRP;

[0040] S3. The modified glass fiber reinforced plastic, sulphoaluminate cement, silicate cement and gypsum powder were mixed in a mass ratio of 1:40:20:8 and stirred to obtain a composite curing agent;

[0041] S4. Crush the solid waste and weathered materials and remove foreign matter and contaminated and deteriorated parts in the solid waste, add water, cement, fly ash, retarder, homemade anti-dispersion agent and composite curing agent, the mass ratio of solid waste, weathered materials, water, cement, fly ash, homemade anti-dispersion agent and composite curing agent is 20:10:10:3:0.6:0.6:3, stir evenly to obtain solidified soil prepared from solid waste.

[0042] Comparative Example 1: The difference between the solidified soil prepared from the solid waste and Example 2 is that the homemade anti-dispersion agent is obtained by directly generating nano-silicon dioxide in situ on the surface of the pretreated aramid fiber, and the rest is the same as Example 2.

[0043] Comparative Example 2: The difference between the solidified soil prepared from the solid waste and Example 2 is that step S1 is different, and step S1 is modified as follows: aramid fiber, hydroxypolyvinyl pyrrolidone and chloroform are mixed in a mass ratio of 8:2:50, heated to 85°C, concentrated sulfuric acid with a mass of 0.15 times that of hydroxypolyvinyl pyrrolidone is added, reacted for 7 hours, cooled to room temperature, filtered, and transferred to a mixture of ethyl orthosilicate with a mass of 25 times that of hydroxypolyvinyl pyrrolidone, wherein ethyl orthosilicate, anhydrous ethanol and deionized water in the ethyl orthosilicate mixture are mixed. The mass ratio is 1:7:3. After shaking for 4 minutes, the pH is adjusted to 2.5 with hydrochloric acid, the temperature is raised to 43°C, the reaction is carried out for 1.5 hours, and the mixture is cooled to room temperature. The pH is adjusted to 7.0 with aqueous ammonia. After gelation, it is allowed to stand for 7 minutes. Six times the mass of hydroxypolyvinyl pyrrolidone is tetraethyl orthosilicate and 15 times the mass of hydroxypolyvinyl pyrrolidone is added. After stirring evenly, the mixture is aged at room temperature for 13 hours, dried at 85°C for 3.5 hours, and dried at 125°C for 5.5 hours to obtain a homemade anti-dispersant. The rest is the same as in Example 2.

[0044] Comparative Example 3: The difference between the solidified soil prepared from the solid waste and Example 2 is that the composite curing agent includes glass fiber reinforced plastics, sulphoaluminate cement, silicate cement and gypsum powder, and the rest is the same as Example 2.

[0045] Comparative Example 4: The difference between the solidified soil prepared from the solid waste and Example 2 is that the composite curing agent includes sulphoaluminate cement, silicate cement and gypsum powder, and the rest is the same as Example 2.

[0046] Effect example: Table 1 below shows the performance analysis results of the solidified soil prepared by using the solid wastes obtained by Examples 1 to 3 of the present invention and Comparative Examples 1 to 4:

[0047] Table 1 Performance analysis data of stabilized soil

[0048]

[0049] By comparing the experimental data of the examples and the comparative examples in Table 1, it can be clearly found that the solidified soil prepared using the solid waste prepared in Examples 1, 2 and 3 has excellent anti-dispersion and strength.

[0050] From the comparison of the experimental data of Example 1, Example 2, Example 3 and Comparative Example 1, Comparative Example 2, it can be found that the hydrogen bonds between the molecular chains of the pretreated aramid fiber are destroyed, and then the surface is coated with hydroxyl polyvinyl pyrrolidone, and the hydroxyl groups on the fiber surface react with the surface active groups of graphene oxide, and graphene oxide with a two-dimensional nano-layered structure is introduced on the surface of the aramid fiber, and then nano-silicon dioxide is generated in situ on the surface to form an aerogel with a rough surface and adsorption capacity, which can absorb free water, promote the hydration reaction between the components in the solidified soil, enter the solidified soil components, reduce dispersion, and thus maintain the strength of the solidified soil.

[0051] From the comparison of the experimental data of Example 1, Example 2, Example 3 and Comparative Example 3, Comparative Example 4, it can be found that when the FRP powder is coated with the mercapto cross-linked polymer, a cross-linked network structure is formed on the surface, so that the composite curing agent forms a through curing network during the curing process, enters into the structure of the cured soil, prevents shrinkage and deformation, and enhances the curing strength.

[0052] Obviously, the above embodiments are merely examples for clearly illustrating the embodiments of the present invention, and are not intended to limit the embodiments of the present invention. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the embodiments here. However, these obvious changes or modifications derived from the spirit of the present invention are still within the scope of protection of the present invention.

Claims

1. A solidified soil prepared from solid waste, characterized in that: The invention comprises solid waste, weathered material, water, cement, fly ash, a self-made anti-dispersant and a composite curing agent; the self-made anti-dispersant is prepared by introducing graphene oxide on the surface of pretreated aramid fiber and then in-situ generating nano-silicon dioxide on the surface; the aramid fiber is short-cut aramid fiber; the composite curing agent comprises modified glass fiber reinforced plastic, sulphoaluminate cement, silicate cement and gypsum powder; the modified glass fiber reinforced plastic is prepared by carboxylating glass fiber reinforced plastic and coating it with a mercapto cross-linked polymer; the glass fiber reinforced plastic is glass fiber reinforced plastic powder The preparation method of the self-made anti-dispersion agent is as follows: the aramid fiber is placed in a 60-80kHz ultrasonic cleaning for 8-10 minutes, and after drying, it is immersed in a lithium chloride solution with a mass fraction of 7-10%, heated to 76-78°C, reacted for 3-4 hours, taken out and washed with deionized water and anhydrous ethanol for 3-5 times in sequence, and dried to obtain the pretreated aramid fiber; the pretreated aramid fiber, hydroxypolyvinyl pyrrolidone and chloroform are mixed in a mass ratio of 8:1-3:50, and heated to 80-9 0℃, add concentrated sulfuric acid with a mass of 0.1~0.2 times that of hydroxypolyvinyl pyrrolidone, react for 6~8h, add graphene oxide with a mass of 0.2~0.4 times that of hydroxypolyvinyl pyrrolidone, continue to react for 2~4h, cool to room temperature, filter, transfer to a mixture of ethyl orthosilicate with a mass of 20~30 times that of hydroxypolyvinyl pyrrolidone, the mass ratio of ethyl orthosilicate, anhydrous ethanol and deionized water in the ethyl orthosilicate mixture is 0.8~1.2:7:3, shake for 3~5min, and then add hydrochloric acid The pH value was adjusted to 2-3, the temperature was raised to 40-45°C, the reaction was performed for 1-2 hours, the mixture was cooled to room temperature, the pH value was adjusted to 6.8-7.2 with aqueous ammonia, the mixture was allowed to stand for 5-8 minutes after gelation, 4-8 times the mass of hydroxypolyvinyl pyrrolidone of tetraethyl orthosilicate and 10-20 times the mass of hydroxypolyvinyl pyrrolidone of anhydrous ethanol were added, the mixture was stirred evenly, and the mixture was aged at room temperature for 12-14 hours, the mixture was dried at 80-90°C for 3-4 hours, the temperature was raised to 120-130°C and dried for 5-6 hours to obtain a homemade anti-dispersant.

2. The solidified soil prepared from solid waste according to claim 1, characterized in that: The solid waste includes any one of waste cement, waste concrete, waste ceramic bricks or industrial tailings, or a combination of at least two of them.

3. The solidified soil prepared from solid waste according to claim 1, characterized in that: The cement is at least one of slag silicate cement and fly ash silicate cement.

4. A method for preparing solidified soil from solid waste, characterized in that: The specific steps include: S1. The pretreated aramid fiber, hydroxypolyvinyl pyrrolidone and chloroform were mixed in a mass ratio of 8:1-3:50, heated to 80-90°C, and concentrated sulfuric acid was added in an amount of 0.1-0.2 times the mass of hydroxypolyvinyl pyrrolidone, and the reaction was continued for 6-8 hours. Graphene oxide was added in an amount of 0.2-0.4 times the mass of hydroxypolyvinyl pyrrolidone, and the reaction was continued for 2-4 hours. The mixture was cooled to room temperature, filtered, and transferred to a mixture of ethyl orthosilicate in an amount of 20-30 times the mass of hydroxypolyvinyl pyrrolidone. The mass ratio of ethyl orthosilicate, anhydrous ethanol and deionized water in the ethyl orthosilicate mixture was 0. .8~1.2:7:3, after shaking for 3~5 minutes, adjust the pH to 2~3 with hydrochloric acid, heat to 40~45℃, react for 1~2 hours, cool to room temperature, adjust the pH to 6.8~7.2 with ammonia water, let stand for 5~8 minutes after gelation, add 4~8 times the mass of hydroxy polyvinyl pyrrolidone of tetraethyl orthosilicate and 10~20 times the mass of hydroxy polyvinyl pyrrolidone of anhydrous ethanol, stir evenly and age at room temperature for 12~14 hours, place at 80~90℃ to dry for 3~4 hours, heat to 120~130℃ to dry for 5~6 hours, and prepare the homemade anti-dispersion agent; S2. Carboxylated FRP, mercapto cross-linked polymer and anhydrous ethanol are mixed in a mass ratio of 3-5:1:30-50, stirred evenly and heated to 80-90°C, and 0.02-0.04 times the mass of carboxylated FRP sodium hydroxide is added, reacted for 6-8 hours, filtered and washed with deionized water for 3-5 times, and dried to obtain modified FRP; S3. The modified glass fiber reinforced plastic, sulphoaluminate cement, silicate cement and gypsum powder were mixed in a mass ratio of 1:20~40:20:4~8 and stirred to obtain a composite curing agent; S4. Crush the solid waste and weathered materials, remove foreign matter and polluted and deteriorated parts in the solid waste, add water, cement, fly ash, retarder, homemade anti-dispersion agent and composite curing agent, stir evenly, and obtain solidified soil prepared from solid waste.

5. The method for preparing solidified soil from solid waste according to claim 4, characterized in that: In the above step S1, the preparation method of hydroxypolyvinyl pyrrolidone is: under a nitrogen atmosphere, isopropanol, thioglycerol, N-vinyl pyrrolidone and azobisisobutyronitrile are mixed in a mass ratio of 5:10~20:1:0.02~0.04, stirred evenly and heated to 78~82°C, reacted for 24 hours, cooled to room temperature and rotary evaporated, washed with ether 3~5 times, filtered under reduced pressure, dissolved in chloroform, precipitated with ether, and finally dried to obtain hydroxypolyvinyl pyrrolidone.

6. The method for preparing solidified soil from solid waste according to claim 4, characterized in that: In the above step S2, the preparation method of carboxylated glass fiber reinforced plastic is: deionized water, tetrabutylammonium iodide and glass fiber reinforced plastic are mixed in a mass ratio of 100:0.4~0.6:6~8, the temperature is raised to 70~72°C, a 2 mol / L sodium hydroxide solution of 4~8 times the mass of the glass fiber reinforced plastic is added, the reaction is stirred at 60~80rpm for 3~5h, the filter is filtered and washed with hydrochloric acid to a pH of 1.8~2.2, and then washed with deionized water 8~10 times, and finally dried at 80~90°C to obtain the carboxylated glass fiber reinforced plastic.

7. The method for preparing solidified soil from solid waste according to claim 4, characterized in that: In the above step S2, the preparation method of the thiol cross-linked polymer is: under a nitrogen atmosphere, dibenzyl disulfide, biphenyl dichlorobenzyl and 1,2-dichloromethane are mixed in a mass ratio of 0.03-0.05:10:4, the temperature is raised to 40-42°C, and after stirring evenly, ferric chloride is added in an amount of 2.2-2.4 times the mass of dibenzyl disulfide, the temperature is raised to 60-80°C, the reaction is carried out for 24 hours, and Soxhlet extraction is carried out with methanol. The pH is adjusted to 4.8-5.2 with a tris(2-carboxyethyl)phosphine hydrochloride solution with a mass fraction of 1-3%, ethanol is added in an amount of 0.02-0.04 times the mass of dibenzyl disulfide, and the reaction is carried out for 1-2 hours, followed by suction filtration and drying to obtain a thiol cross-linked polymer.

8. The method for preparing solidified soil from solid waste according to claim 4, characterized in that: In the above step S4, the mass ratio of solid waste, weathered material, water, cement, fly ash, homemade anti-dispersion agent and composite curing agent is 15~20:5~10:8~10:1~3:0.3~0.6:0.2~0.6:1~3.

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