A fluidized solidified soil improver and preparation method thereof

Abstract

The present invention proposes a fluidized solidified soil improver and a preparation method thereof, and belongs to the technical field of improvers. The fluidized solidified soil improver is prepared by the following raw materials by weight: 20-40 parts of modified glue, 4-7 parts of active materials, 15-25 parts of micro-expansion materials, 1-2 parts of stimulants, and 2-4 parts of auxiliary agents. The soil solidified by the fluidized solidified soil improver of the present invention has good mechanical strength, small dosage, low cost, convenient construction, high early strength and late stable strength of the soil, and good water retention and water resistance. The strength does not change much after encountering water, and the active material has good stability, low cost, high enzyme loading, improved enzyme catalytic ability, safe and non-toxic, low maintenance cost in the later stage, reusable, heavy metal pollution repair ability, can degrade heavy metals, reduce the amount of chemical degradation elements, and has broad application prospects.

Description

Technical Field

[0001] The present invention relates to the technical field of improvers, and in particular to a fluidized solidified soil improver and a preparation method thereof. Background Art

[0002] Fluidized solidified soil conditioner is a composite material composed of a variety of inorganic and organic materials used to improve and enhance the engineering performance of fluidized soil. It has the advantages of fast curing speed, high early strength, long consolidation time, high late strength, small dosage, local materials, saving construction time and reducing project costs. It has broad application prospects in highway, railway, subway, water conservancy, housing and other engineering construction.

[0003] There are many types of fluidized solidified soil improvers, but they can be divided into lime cement curing agents, slag silicate curing agents, polymer curing agents and ion solution curing agents according to the development process. Among them, polymer curing agents also include a variety of resins, fibers, surfactants and other curing agents. Polymer curing agents are a type of soil curing agent that uses surfactants to change the hydrophilic properties of the surface of soil particles, or uses polymer cross-linking to form a three-dimensional structure to wrap and cement soil particles. On the basis of soil compaction, it can obtain a good compressive strength. It has the advantages of small dosage, low cost, convenient construction, and both the early strength and later stable strength of the soil can meet the requirements; but it also has the disadvantages of poor water resistance and a sharp decrease in strength when exposed to water.

[0004] Chinese invention patent CN107032710A discloses a composite soil solidifier, which is composed of the following components by weight: 5-15 parts of ordinary Portland cement, 60-90 parts of sulfur-fixing ash, 3-8 parts of activator, 1-5 parts of early strength agent, 1-3 parts of silica fume, 2-6 parts of quicklime, and 0.02-0.1 parts of polyacrylamide. Although the composite soil solidifier can improve the roadbed structure and enhance the roadbed strength, it takes a long time to solidify, and the solidification process is prone to cracking and collapse in the later stage, and the comprehensive solidification effect is not good. Summary of the invention

[0005] The purpose of the present invention is to provide a fluidized solidified soil improver and a preparation method thereof. The solidified soil has good mechanical strength, small dosage, low cost, convenient construction, high early soil strength and late stable strength, good water retention and water resistance, and little change in strength after contact with water. The active material has good stability, low cost, high enzyme loading, improved enzyme catalytic ability, safety and non-toxicity, low late maintenance cost, reusability, heavy metal pollution repair ability, heavy metal degradability, and reduced chemical degradation element dosage, and has broad application prospects.

[0006] The technical solution of the present invention is achieved in this way:

[0007] The invention provides a fluidized solidified soil improver, which is prepared from the following raw materials in parts by weight: 20-40 parts of modified glue, 4-7 parts of active materials, 15-25 parts of micro-expansion materials, 1-2 parts of activators, and 2-4 parts of auxiliary agents.

[0008] As a further improvement of the present invention, the preparation method of the modified glue solution is as follows:

[0009] Alkyl orthosilicate, ethanol and water are uniformly mixed and stirred, and a silane coupling agent is added and stirred to react to obtain a modified adhesive solution.

[0010] As a further improvement of the present invention, the mass ratio of the alkyl orthosilicate, ethanol, water and silane coupling agent is 10-12:60-80:10-15:3-5; the alkyl orthosilicate is methyl orthosilicate or ethyl orthosilicate, the silane coupling agent is a mixture of KH550, KH570 and KH580 in a mass ratio of 10:7-9:2-4, and the stirring reaction time is 1-2h.

[0011] As a further improvement of the present invention, the preparation method of the micro-expanded material is as follows:

[0012] Add methyl acrylate, acrylic acid and styrene into water, add surfactant, heat and stir to mix, add initiator, increase the temperature, stir to react, cool to room temperature, filter and grind to obtain micro-expanding material.

[0013] As a further improvement of the present invention, the mass ratio of the methyl acrylate, acrylic acid, styrene, surfactant and initiator is 7-10:4-6:3-5:0.5-1:0.1-0.15, the surfactant includes Tween and Span, the mass ratio is 1-2:1, the Tween is selected from at least one of Tween-20, Tween-40, Tween-60 and Tween-80, the Span is selected from at least one of Span-20, Span-40, Span-60 and Span-80, the initiator is selected from at least one of sodium persulfate, potassium persulfate and ammonium persulfate, the temperature of the heating, stirring and mixing is 40-50°C, the temperature is increased to 80-90°C, and the stirring reaction time is 3-5h.

[0014] As a further improvement of the present invention, the active material is an immobilized biological enzyme, and the preparation method is as follows:

[0015] S1. Collect saliva, dry it, and mix it evenly with laccase to obtain a biological enzyme;

[0016] S2. The nano-silica balls were added to water, ferric chloride and ferrous chloride were added, stirred and mixed, ammonia was added dropwise to adjust the pH value of the solution, heated and stirred, centrifuged, washed, dried, and calcined to obtain magnetic nano-silica balls;

[0017] S3. The magnetic nano-silica spheres are added to an ethanol solution, a silane coupling agent is added, the reaction is heated and stirred, the reaction is separated by a magnet, washed, and dried to obtain modified magnetic nano-silica spheres;

[0018] S4. Add silk fibroin peptide and biological enzyme into water, add NHS and EDC, stir to activate, then add modified magnetic nano-silica spheres and chitosan, stir to react, separate with a magnet, wash, and dry to obtain immobilized biological enzyme.

[0019] As a further improvement of the present invention, the mass ratio of saliva to laccase in step S1 is 100:2-3; the average particle size of the nano-silica balls in step S2 is 100-200nm, the mass ratio of the nano-silica balls, ferric chloride and ferrous chloride is 10:3.24:1.26, the pH value of the adjusted solution is 9-10, the temperature of the heated and stirred reaction is 80-90°C, the time is 2-4h, the calcination temperature is 400-500°C, and the time is 1-2h; the silane coupling agent in step S3 is KH550, KH602 or KH792, the mass ratio of the magnetic nano-silica spheres and the silane coupling agent is 10:1-2, the temperature of the heating and stirring reaction is 40-50°C, and the time is 2-3h; the mass ratio of the silk fibroin peptide, biological enzyme, NHS, EDC, modified magnetic nano-silica spheres and chitosan in step S4 is 3-5:4-6:0.5-1:0.7-1.2:20-30:7-10, the stirring activation time is 1-2h, and the stirring reaction time is 10-12h.

[0020] As a further improvement of the present invention, the activator is a composition of hydrochloric acid and an initiator, the mass ratio of which is 100:2-3, the concentration of the hydrochloric acid is 3-4 mol / L, and the initiator is selected from at least one of sodium persulfate, potassium persulfate, and ammonium persulfate.

[0021] As a further improvement of the present invention, the auxiliary agent comprises a mixture of a binder and a reinforcing agent in a mass ratio of 2-3:1-2, the binder is sodium alginate, and the reinforcing agent is silica fume.

[0022] The present invention further protects a method for preparing the above-mentioned fluidized solidified soil conditioner, comprising the following steps:

[0023] (1) uniformly mixing the modified adhesive, micro-expansion material, active material and additive to obtain a mixture;

[0024] (2) Add an activator to the mixture, heat to 50-60°C, stir and react for 3-5 hours, and dry to obtain a fluidized solidified soil conditioner.

[0025] The present invention has the following beneficial effects:

[0026] The invention relates to a fluidized solidified soil improver, the raw materials of which are composed of a cementitious material, an active material, a micro-expansion material, an activator and an auxiliary agent. The solidified soil mixture prepared by the fluidized soil improver has the advantages of high fluidity and dispersion retention, low construction cost, strong adaptability to base soil, high mechanical properties and the like.

[0027] After the biological enzyme is mixed with the soil, the catalytic activity reaction of the enzyme can accelerate the rate of decomposition and metabolism of organic matter in the soil, reduce the content of organic matter in the pores, reduce the resistance of soil compaction, and improve the density, bearing capacity, compression and frost resistance of the soil, so that the soil has good consolidation and stability. Under the compaction effect, the compacted soil no longer has the ability to absorb water, which reduces the water content of the soil, weakens the tendency of soil particles to absorb water and expand, and produces a shielding effect on water, forming a waterproof soil layer, thereby increasing the density of the compacted soil. However, directly adding the biological enzyme to the soil, because it is soluble in water, it is very easy to be lost under the scouring effect of running water in the soil, which not only greatly reduces its effect, but also makes the amount of biological enzyme added have to be greatly increased, thereby greatly increasing its cost, which is not conducive to industrial application, and enzymes, as proteins, are easy to deteriorate and have poor stability.

[0028] The present invention adopts immobilized biological enzymes and magnetic modification. After the fluidized solidified soil improver is solidified and modified, only simple magnetic separation is required for recovery. The present invention has high mechanical strength and good stability. The immobilized biological enzyme can be reused, thereby greatly reducing the cost. At the same time, the biological enzyme of the present invention uses animal saliva as the main raw material, and the raw material source is wide and the cost is low. The immobilized enzyme carrier has a large specific surface area and a high enzyme loading capacity, which greatly improves the catalytic ability of the enzyme, has good biocompatibility, is safe and non-toxic. By adding the immobilized biological enzyme, the construction process of the fluidized solidified soil improver is simple, the construction period can be shortened after use, the construction efficiency is improved, and the later maintenance cost is low. At the same time, the present invention has the ability to repair heavy metal pollution, can adsorb and fix heavy metals, and reduce the amount of chemical degradation factors.

[0029] In the present invention, magnetic ferrosoferric oxide is deposited in situ on the surface of nano-silicon dioxide to prepare magnetic nano-silicon dioxide balls, the surface of which is modified by a silane coupling agent with an amino group, and then silk fibroin peptides and biological enzymes are activated by carboxyl groups and react with the amino groups of the modified magnetic nano-silicon dioxide balls and chitosan, so that a large amount of biological enzymes are loaded on the surface of the carrier, and the coating of chitosan and silk fibroin peptides greatly increases the specific surface area of ​​the carrier and the protective effect on the biological enzymes, thereby improving the stability of the biological enzymes, making them less likely to be inactivated, and at the same time, having little effect on the enzyme activity, and having the ability to repair heavy metal pollution.

[0030] The modified glue liquid of the present invention is prepared by modifying the silica sol with a silane coupling agent. Under the catalytic action of an activator, the silica sol can be promoted to undergo a sol-gel reaction. At the same time, the initiator can promote the copolymerization of the part with double bonds with the micro-swelling material, thereby cross-linking, or the part with amino or thiol groups is hydrogen-bonded with the micro-swelling material, thereby improving the structure of the soil and thus increasing the soil cohesion. Due to its water absorption and hydrophilic properties, it can adsorb a part of smaller aggregates to form a larger aggregate structure, effectively increase the content of water-stable aggregates in the soil, have a certain retention effect on water, and improve the solidification ability of the convective soil.

[0031] The soil solidified by the fluidized solidified soil improver of the present invention has good mechanical strength, small dosage, low cost, convenient construction, high early soil strength and late stable strength, good water retention and water resistance, and little change in strength after contacting water. The active material has good stability, low cost, high enzyme loading, improved enzyme catalytic ability, safety and non-toxicity, low late maintenance cost, reusability, heavy metal pollution repair ability, can degrade heavy metals, reduce the amount of chemical degradation elements, and has broad application prospects. DETAILED DESCRIPTION

[0032] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0033] The average particle size of nano-silica spheres was 100-200 nm and was purchased from Jinan Yongyue Chemical Co., Ltd.

[0034] Silk fibroin peptide, content >90%, was purchased from Wuhan Kemik Biopharmaceutical Technology Co., Ltd.

[0035] Chitosan, with a deacetylation degree of >80%, was purchased from Anhui Xinsheng Biotechnology Co., Ltd.

[0036] Preparation Example 1 Preparation of modified rubber solution

[0037] Here’s how:

[0038] Mix 10 g of methyl orthosilicate, 60 g of ethanol and 10 g of water evenly, stir to mix, add 3 g of silane coupling agent, stir and react at 40° C. for 1 hour to obtain a modified rubber solution.

[0039] The silane coupling agent is a mixture of KH550, KH570 and KH580, with a mass ratio of 10:7:2.

[0040] Preparation Example 2 Preparation of modified adhesive solution

[0041] Here’s how:

[0042] Mix 12g of ethyl orthosilicate, 80g of ethanol and 15g of water evenly, stir to mix, add 5g of silane coupling agent, stir and react at 40°C for 2h to obtain a modified rubber solution.

[0043] The silane coupling agent is a mixture of KH550, KH570 and KH580, with a mass ratio of 10:9:4.

[0044] Preparation Example 3 Preparation of modified rubber solution

[0045] Here’s how:

[0046] Mix 11 g of ethyl orthosilicate, 70 g of ethanol and 12 g of water evenly, stir to mix, add 4 g of silane coupling agent, stir and react at 40° C. for 1.5 hours to obtain a modified rubber solution.

[0047] The silane coupling agent is a mixture of KH550, KH570 and KH580, with a mass ratio of 10:8:3.

[0048] Comparative Preparation Example 1

[0049] Compared with Preparation Example 3, the difference is that the silane coupling agent is a mixture of KH550 and KH580, and the mass ratio is 18:3.

[0050] Comparative Preparation Example 2

[0051] Compared with Preparation Example 3, the difference is that the silane coupling agent is KH570.

[0052] Comparative Preparation Example 3

[0053] Compared with Preparation Example 3, the difference is that no silane coupling agent is added.

[0054] The details are as follows:

[0055] 11 g of ethyl orthosilicate, 70 g of ethanol and 12 g of water were mixed evenly, and stirred at 40° C. for 1.5 h to obtain a glue solution.

[0056] Preparation Example 4 Preparation of micro-expansion material

[0057] Here’s how:

[0058] 7 g of methyl acrylate, 4 g of acrylic acid, and 3 g of styrene were added to 200 mL of water, 0.5 g of a surfactant was added, the mixture was heated to 40° C., stirred and mixed for 20 min, 0.1 g of ammonium persulfate was added, the temperature was raised to 80° C., the mixture was stirred and reacted for 3 h, the mixture was cooled to room temperature, filtered, and ground to obtain a micro-expandable material;

[0059] The surfactant includes Tween-20 and Span-20 in a mass ratio of 1:1.

[0060] Preparation Example 5 Preparation of micro-expansion material

[0061] Here’s how:

[0062] 10 g of methyl acrylate, 6 g of acrylic acid, and 5 g of styrene were added to 200 mL of water, 1 g of a surfactant was added, the mixture was heated to 50° C., stirred and mixed for 20 min, 0.15 g of potassium persulfate was added, the temperature was raised to 90° C., the mixture was stirred and reacted for 5 h, the mixture was cooled to room temperature, filtered, and ground to obtain a micro-expandable material;

[0063] The surfactant includes Tween-40 and Span-40, with a mass ratio of 2:1.

[0064] Preparation Example 6 Preparation of micro-expansion material

[0065] Here’s how:

[0066] 8 g of methyl acrylate, 5 g of acrylic acid, and 4 g of styrene were added to 200 mL of water, 0.7 g of a surfactant was added, the mixture was heated to 45° C., stirred and mixed for 20 min, 0.12 g of sodium persulfate was added, the temperature was raised to 85° C., the mixture was stirred and reacted for 4 h, the mixture was cooled to room temperature, filtered, and ground to obtain a micro-expandable material;

[0067] The surfactant includes Tween-80 and Span-80, with a mass ratio of 1.5:1.

[0068] Preparation Example 7 Preparation of immobilized enzyme

[0069] Here’s how:

[0070] S1. 100 g of saliva was collected and dried, and mixed with 2 g of laccase to obtain a biological enzyme;

[0071] S2. 10 g of nano-silica spheres were added to 200 mL of water, 3.24 g of ferric chloride and 1.26 g of ferrous chloride were added, the mixture was stirred and mixed evenly, ammonia water was added dropwise to adjust the pH value of the solution to 9, the mixture was heated to 80°C, stirred and reacted for 2 h, centrifuged, washed, dried, and calcined at 400°C for 1 h to obtain magnetic nano-silica spheres;

[0072] S3. 10 g of magnetic nano-silica spheres were added to 200 mL of ethanol solution, 1 g of silane coupling agent KH602 was added, the mixture was heated to 40°C, stirred for reaction for 2 h, separated by magnet, washed, and dried to obtain modified magnetic nano-silica spheres;

[0073] S4. Add 3g silk fibroin peptide and 4g bio-enzyme into 200mL water, add 0.5g NHS and 0.7g EDC, stir and activate for 1h, then add 20g modified magnetic nano-silica spheres and 7g chitosan, stir and react for 10h, separate with a magnet, wash and dry to obtain the immobilized bio-enzyme.

[0074] Preparation Example 8 Preparation of immobilized enzyme

[0075] Here’s how:

[0076] S1. 100 g of saliva was collected and dried, and mixed evenly with 3 g of laccase to obtain a biological enzyme;

[0077] S2. 10 g of nano-silica spheres were added to 200 mL of water, 3.24 g of ferric chloride and 1.26 g of ferrous chloride were added, the mixture was stirred and evenly mixed, ammonia water was added dropwise to adjust the pH value of the solution to 10, the mixture was heated to 90°C, stirred and reacted for 4 h, centrifuged, washed, dried, and calcined at 500°C for 2 h to obtain magnetic nano-silica spheres;

[0078] S3. 10 g of magnetic nano-silica spheres were added to 200 mL of ethanol solution, 2 g of silane coupling agent KH792 was added, the mixture was heated to 50°C, stirred for reaction for 3 h, separated by magnet, washed, and dried to obtain modified magnetic nano-silica spheres;

[0079] S4. Add 5g silk fibroin peptide and 6g bio-enzyme into 200mL water, add 1g NHS and 1.2g EDC, stir and activate for 2h, then add 30g modified magnetic nano-silica spheres and 10g chitosan, stir and react for 12h, separate with a magnet, wash and dry to obtain the immobilized bio-enzyme.

[0080] Preparation Example 9 Preparation of immobilized enzyme

[0081] Here’s how:

[0082] S1. 100 g of saliva was collected and dried, and mixed with 2.5 g of laccase to obtain a biological enzyme;

[0083] S2. 10 g of nano-silica spheres were added to 200 mL of water, 3.24 g of ferric chloride and 1.26 g of ferrous chloride were added, the mixture was stirred and evenly mixed, ammonia water was added dropwise to adjust the pH value of the solution to 9.5, the solution was heated to 85°C, stirred and reacted for 3 h, centrifuged, washed, dried, and calcined at 450°C for 1.5 h to obtain magnetic nano-silica spheres;

[0084] S3. 10 g of magnetic nano-silica spheres were added to 200 mL of ethanol solution, 1.5 g of silane coupling agent KH550 was added, the mixture was heated to 45°C, stirred for reaction for 2.5 h, separated by magnet, washed, and dried to obtain modified magnetic nano-silica spheres;

[0085] S4. Add 4g silk fibroin peptide and 5g bio-enzyme into 200mL water, add 0.7g NHS and 1g EDC, stir and activate for 1.5h, then add 25g modified magnetic nano-silica spheres and 8.5g chitosan, stir and react for 11h, separate with a magnet, wash and dry to obtain the immobilized bio-enzyme.

[0086] Comparative Preparation Example 4

[0087] Compared with Example 9, the difference is that laccase is not added in step S1.

[0088] The details are as follows:

[0089] S1. Collect 100g of saliva and dry it to obtain biological enzyme.

[0090] Comparative Preparation Example 5

[0091] Compared with Example 9, the difference is that no saliva is added in step S1.

[0092] The details are as follows:

[0093] S1. Laccase as a biological enzyme.

[0094] Comparative Preparation Example 6

[0095] Compared with Example 9, the difference is that silk fibroin peptide and chitosan are not added in step S4.

[0096] The details are as follows:

[0097] S4. Add 5g of bio-enzyme into 200mL of water, add 0.7g of NHS and 1g of EDC, stir and activate for 1.5h, then add 25g of modified magnetic nano-silica balls, stir and react for 11h, separate with a magnet, wash, and dry to obtain the immobilized bio-enzyme.

[0098] Comparative Preparation Example 7

[0099] Compared with Example 9, the difference is that chitosan is not added in step S4.

[0100] The details are as follows:

[0101] S4. Add 4g silk fibroin peptide and 5g bio-enzyme into 200mL water, add 0.7g NHS and 1g EDC, stir and activate for 1.5h, then add 25g modified magnetic nano-silica balls, stir and react for 11h, separate with a magnet, wash and dry to obtain the immobilized bio-enzyme.

[0102] Example 1

[0103] This embodiment provides a method for preparing a fluidized solidified soil conditioner, comprising the following steps:

[0104] (1) 20 g of the modified adhesive prepared in Preparation Example 1, 15 g of the micro-expandable material prepared in Preparation Example 4, 4 g of the active material prepared in Preparation Example 7, and 2 g of the auxiliary agent were stirred and mixed for 30 minutes to prepare a mixture;

[0105] The auxiliary agent is a mixture of sodium alginate and silica fume, with a mass ratio of 2:1.

[0106] (2) Add 1 g of activator to the mixture, heat to 50°C, stir and react for 3 h, and dry to obtain a fluidized solidified soil conditioner;

[0107] The activator is a composition of hydrochloric acid and sodium persulfate, with a mass ratio of 100:2, and the concentration of the hydrochloric acid is 3 mol / L.

[0108] Example 2

[0109] This embodiment provides a method for preparing a fluidized solidified soil conditioner, comprising the following steps:

[0110] (1) 40 g of the modified adhesive prepared in Preparation Example 2, 25 g of the micro-expandable material prepared in Preparation Example 5, 7 g of the active material prepared in Preparation Example 8, and 4 g of the auxiliary agent were stirred and mixed for 30 minutes to prepare a mixture;

[0111] The auxiliary agent is a mixture of sodium alginate and silica fume, with a mass ratio of 3:2.

[0112] (2) Add 2 g of activator to the mixture, heat to 60°C, stir and react for 5 h, and dry to obtain a fluidized solidified soil conditioner;

[0113] The activator is a composition of hydrochloric acid and potassium persulfate, with a mass ratio of 100:3, and the concentration of the hydrochloric acid is 4 mol / L.

[0114] Example 3

[0115] This embodiment provides a method for preparing a fluidized solidified soil conditioner, comprising the following steps:

[0116] (1) 30 g of the modified adhesive prepared in Preparation Example 3, 20 g of the micro-expandable material prepared in Preparation Example 6, 5.5 g of the active material prepared in Preparation Example 9, and 3 g of the auxiliary agent were stirred and mixed for 30 minutes to prepare a mixture;

[0117] The auxiliary agent is a mixture of sodium alginate and silica fume, with a mass ratio of 2.5:1.5.

[0118] (2) Add 1.5 g of activator to the mixture, heat to 55°C, stir and react for 4 h, and dry to obtain a fluidized solidified soil conditioner;

[0119] The activator is a composition of hydrochloric acid and ammonium persulfate, with a mass ratio of 100:2.5, and the concentration of the hydrochloric acid is 3.5 mol / L.

[0120] Comparative Example 1

[0121] Compared with Example 3, the difference is that the modified rubber solution is prepared by Comparative Preparation Example 1.

[0122] Comparative Example 2

[0123] Compared with Example 3, the difference is that the modified rubber solution is prepared by Comparative Preparation Example 2.

[0124] Comparative Example 3

[0125] Compared with Example 3, the difference is that the modified rubber solution is prepared by Comparative Preparation Example 3.

[0126] Comparative Example 4

[0127] Compared with Example 3, the difference is that the active material is prepared by Comparative Preparation Example 4.

[0128] Comparative Example 5

[0129] Compared with Example 3, the difference is that the active material is prepared by Comparative Preparation Example 5.

[0130] Comparative Example 6

[0131] Compared with Example 3, the difference is that the active material is prepared by Comparative Preparation Example 6.

[0132] Comparative Example 7

[0133] Compared with Example 3, the difference is that the active material is prepared by Comparative Preparation Example 7.

[0134] Comparative Example 8

[0135] Compared with Example 3, the difference is that no modified glue solution is added.

[0136] The details are as follows:

[0137] (1) 20 g of the micro-expanded material prepared in Preparation Example 6, 5.5 g of the active material prepared in Preparation Example 9, and 3 g of the auxiliary agent were stirred and mixed for 30 minutes to prepare a mixture;

[0138] The auxiliary agent is a mixture of sodium alginate and silica fume, with a mass ratio of 2.5:1.5.

[0139] (2) Add 1.5 g of activator to the mixture, heat to 55°C, stir and react for 4 h, and dry to obtain a fluidized solidified soil conditioner;

[0140] The activator is a composition of hydrochloric acid and ammonium persulfate, with a mass ratio of 100:2.5, and the concentration of the hydrochloric acid is 3.5 mol / L.

[0141] Comparative Example 9

[0142] The difference compared with Example 3 is that no active material is added.

[0143] The details are as follows:

[0144] (1) 30 g of the modified adhesive prepared in Preparation Example 3, 20 g of the micro-expansion material prepared in Preparation Example 6, and 3 g of an auxiliary agent were stirred and mixed for 30 minutes to prepare a mixture;

[0145] The auxiliary agent is a mixture of sodium alginate and silica fume, with a mass ratio of 2.5:1.5.

[0146] (2) Add 1.5 g of activator to the mixture, heat to 55°C, stir and react for 4 h, and dry to obtain a fluidized solidified soil conditioner;

[0147] The activator is a composition of hydrochloric acid and ammonium persulfate, with a mass ratio of 100:2.5, and the concentration of the hydrochloric acid is 3.5 mol / L.

[0148] Comparative Example 10

[0149] Compared with Example 3, the difference is that no micro-expansion material is added.

[0150] The details are as follows:

[0151] (1) 30 g of the modified rubber solution prepared in Preparation Example 3, 5.5 g of the active material prepared in Preparation Example 9, and 3 g of the auxiliary agent were stirred and mixed for 30 minutes to prepare a mixture;

[0152] The auxiliary agent is a mixture of sodium alginate and silica fume, with a mass ratio of 2.5:1.5.

[0153] (2) Add 1.5 g of activator to the mixture, heat to 55°C, stir and react for 4 h, and dry to obtain a fluidized solidified soil conditioner;

[0154] The activator is a composition of hydrochloric acid and ammonium persulfate, with a mass ratio of 100:2.5, and the concentration of the hydrochloric acid is 3.5 mol / L.

[0155] Test Example 1

[0156] Sandy soil was used as the basic soil sample and passed through an 80-mesh round hole sieve before use. The fluidized solidified soil modifiers prepared in Examples 1-3 and Comparative Examples 1-10 of the present invention were added to the soil to be reinforced in an amount of 5%. The conventional engineering implementation method of fluidized solidified soil was used for construction. A cubic specimen with a side length of 70.7 mm was used as a standard size specimen. The molding of the specimen should be carried out according to the method specified in the current industry standard "Cement Soil Mix Design Code" JGJ / T 233. The flow expansion was between 160-220 mm. Then, according to DBJ51 / T188-2022 "Technical Standard for Engineering Application of Premixed Fluidized Solidified Soil", the 28-day compressive strength and water stability coefficient of the fluidized solidified soil were respectively determined, and the compressive strength after ten freeze-thaw cycles was tested. The test results are shown in Table 1.

[0157] Table 1

[0158]

[0159] It can be seen from the above table that the soil improved by the fluidized solidified soil conditioner prepared in Examples 1-3 of the present invention has high compressive strength and low water absorption rate, can significantly improve the strength and water resistance of the reinforced soil, has high compressive strength after ten freeze-thaw cycles, good frost resistance, high water stability coefficient, and good water stability, durability, and impermeability.

[0160] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A fluidized solidified soil conditioner, characterized in that: The invention is prepared from the following raw materials by weight: 20-40 parts of modified adhesive, 4-7 parts of active material, 15-25 parts of micro-expansion material, 1-2 parts of activator, and 2-4 parts of auxiliary agent; The preparation method of the modified glue solution is as follows: Mix alkyl orthosilicate, ethanol and water evenly, stir to mix, add silane coupling agent, stir to react, and prepare modified glue solution; The mass ratio of the alkyl orthosilicate, ethanol, water and silane coupling agent is 10-12:60-80:10-15:3-5; the alkyl orthosilicate is methyl orthosilicate or ethyl orthosilicate, the silane coupling agent is a mixture of KH550, KH570 and KH580, the mass ratio is 10:7-9:2-4, and the stirring reaction time is 1-2h; The preparation method of the micro-expanded material is as follows: Add methyl acrylate, acrylic acid and styrene into water, add surfactant, heat and stir to mix, add initiator, increase temperature, stir to react, cool to room temperature, filter and grind to obtain micro-expandable material; The active material is an immobilized biological enzyme, and the preparation method is as follows: S1. Collect saliva, dry it, and mix it evenly with laccase to obtain a biological enzyme; S2. The nano-silica balls were added to water, ferric chloride and ferrous chloride were added, stirred and mixed, ammonia was added dropwise to adjust the pH value of the solution, heated and stirred, centrifuged, washed, dried, and calcined to obtain magnetic nano-silica balls; S3. The magnetic nano-silica spheres are added to an ethanol solution, a silane coupling agent is added, the reaction is heated and stirred, the reaction is separated by a magnet, washed, and dried to obtain modified magnetic nano-silica spheres; S4. Adding silk fibroin peptide and biological enzyme to water, adding NHS and EDC, stirring to activate, then adding modified magnetic nano-silica spheres and chitosan, stirring to react, separating with a magnet, washing, and drying to obtain an immobilized biological enzyme; The stimulator is a composition of hydrochloric acid and an initiator, the mass ratio of which is 100:2-3, the concentration of the hydrochloric acid is 3-4 mol / L, and the initiator is selected from at least one of sodium persulfate, potassium persulfate, and ammonium persulfate; The auxiliary agent comprises a binder and a reinforcing agent in a mass ratio of 2-3:1-2. The binder is sodium alginate and the reinforcing agent is silica fume.

2. The fluidized solidified soil conditioner according to claim 1, characterized in that: The mass ratio of methyl acrylate, acrylic acid, styrene, surfactant and initiator is 7-10:4-6:3-5:0.5-1:0.1-0.15, the surfactant includes Tween and Span in a mass ratio of 1-2:1, the Tween is selected from at least one of Tween-20, Tween-40, Tween-60 and Tween-80, the Span is selected from at least one of Span-20, Span-40, Span-60 and Span-80, the initiator is selected from at least one of sodium persulfate, potassium persulfate and ammonium persulfate, the temperature of heating, stirring and mixing is 40-50°C, the temperature is increased to 80-90°C, and the stirring reaction time is 3-5h.

3. The fluidized solidified soil conditioner according to claim 1, characterized in that: The mass ratio of saliva to laccase in step S1 is 100:2-3; the average particle size of the nano-silica spheres in step S2 is 100-200 nm, and the mass ratio of the nano-silica spheres, ferric chloride and ferrous chloride is 10: 3.24:1.26, the pH value of the adjusted solution is 9-10, the temperature of the heated stirring reaction is 80-90°C, the time is 2-4h, the temperature of the calcination is 400-500°C, and the time is 1-2h; the silane coupling agent in step S3 is KH550, KH602 or KH792, the mass ratio of the magnetic nano-silica spheres and the silane coupling agent is 10:1-2, the temperature of the heated stirring reaction is 40-50°C, and the time is 2-3h; the mass ratio of the silk protein peptide, biological enzyme, NHS, EDC, modified magnetic nano-silica spheres, and chitosan in step S4 is 3-5:4-6:0.5-1:0.7-1.2:20-30:7-10, the stirring activation time is 1-2h, and the stirring reaction time is 10-12h.

4. A method for preparing the fluidized solidified soil conditioner according to any one of claims 1 to 3, characterized in that: The following steps are involved: (1) uniformly mixing the modified adhesive, micro-expansion material, active material and additive to obtain a mixture; (2) Add an activator to the mixture, heat to 50-60°C, stir and react for 3-5 hours, and dry to obtain a fluidized solidified soil conditioner.

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