Curing agent for foundation reinforcement mixing pile and application thereof

Abstract

The invention relates to the field of sludge curing, in particular to a curing agent for a foundation reinforcing mixing pile and application of the curing agent. The curing agent for the foundation reinforcement stirring pile comprises the following raw materials in percentage by mass: 89-93% of an active material, 0.5-1% of a viscosity adjusting material, 0.2-0.8% of a workability adjusting material, 3-5% of a strength adjusting material and 2-5% of a setting time adjusting material, wherein the active material comprises a hydraulic active material and an expansive active material. The curing agent provided by the invention takes the hydraulic active material and the expansive active material as main raw materials, and cooperates with the synergistic interaction effect of the functional additive, so that the curing agent has functionality, and can generate mutual reaction and synergistic promotion effect among the curing agent, water, cured object soil, sludge and solid waste; the strength and other various performance indexes of the solidified soil can be greatly improved, rapid, efficient and uniform solidification of soft soil and sludge is achieved, the mechanical property and durability of the solidified soil are improved, and a high-quality solidified soil material is provided for infrastructure construction.

Description

Technical Field

[0001] This invention relates to the field of sludge solidification, and more particularly to a solidifying agent for foundation reinforcement mixing piles and its application. Background Technology

[0002] Soft soil and silt are mainly formed by the deposition of fine particles such as clay minerals in still or slow-flowing water environments under the influence of electrostatic forces and molecular attraction, and then forming a honeycomb structure through biochemical processes. This type of soil has high natural water content, large void ratio, strong compressibility, low shear strength, poor permeability, and also exhibits thixotropy and fluidity, making it unsuitable for direct engineering applications.

[0003] Mixing piles are a common technical measure for treating silty soft soil foundations. Among them, cement mixing piles are widely used in the reinforcement of weak foundations due to their simple process, convenient construction, and significant economic benefits. Currently, this technology has developed into a mature soft soil treatment method applicable to both land and sea, using both mortar and cement mixtures. The quality of cement mixing piles is mainly affected by two factors: equipment and process, and solidification materials. For a long time, research has focused on improving equipment and processes, aiming to enhance mixing efficiency and quality, especially improving the uniformity of solidified soil mixing. Due to the uneven vertical distribution of soil layers, the quality of cement mixing in local sections may become a bottleneck restricting the overall bearing capacity of the pile. Uneven mixing further amplifies this defect, making it difficult for the performance of other high-strength sections to be fully utilized. Therefore, developing high-performance solidification materials is particularly important.

[0004] Currently, traditional single cementitious materials such as cement and lime often face numerous practical engineering problems when treating soil, silt, and urban solid waste, making it difficult to meet the engineering needs of special environments. Especially in the reinforcement of silty soft soil foundations, cement, as the most commonly used solidification material, often fails to effectively form piles in situations with high organic matter, high salt content silt, or poor geological conditions, or the strength of the piles after formation often fails to meet design requirements, thus limiting its applicability in complex working conditions.

[0005] Therefore, developing a curing agent that can ensure the strength of the piles meets the requirements has become a key issue that urgently needs to be addressed. Summary of the Invention

[0006] This invention provides a curing agent for foundation reinforcement mixing piles and its application, in order to solve the problem of poor strength after pile formation using existing cement curing agents.

[0007] To solve the above-mentioned technical problems, the present invention provides the following technical method: This invention provides a curing agent for foundation reinforcement mixing piles, comprising the following raw materials in weight percentages: Active materials 89%~93%, viscosity modifiers 0.5%~1%, workability modifiers 0.2%~0.8%, strength modifiers 3%~5%, setting time modifiers 2%~5%; The active materials include hydraulic active materials and expandable active materials.

[0008] In some specific embodiments, the mass ratio of the hydraulic active material to the expandable active material is (90~95):(5~10).

[0009] In some specific embodiments, the hydraulic active material includes at least one of cement, mineral powder, power plant slag, fly ash, red mud, and steel slag.

[0010] In some specific embodiments, the expansive active material includes at least one of desulfurized gypsum, silica fume densifier, and calcium-based bentonite.

[0011] In some specific embodiments, the silica content in the silica ash densifier is ≥95% by mass.

[0012] In some specific embodiments, the viscosity modifier includes at least one of cellulose, dispersible powder, polyacrylamide, and xanthan gum.

[0013] In some specific embodiments, the viscosity modifier includes cellulose, dispersible powder, polyacrylamide, and xanthan gum.

[0014] In some specific embodiments, the viscosity modifier comprises the following raw materials in parts by weight: In some specific embodiments, the mass ratio of the cellulose, the dispersible gum powder, the polyacrylamide, and the xanthan gum is 1:(0.8~1.3):(0.3~0.6):(0.8~1.3).

[0015] In some specific embodiments, the workability adjusting material includes a water-reducing agent; the water-reducing agent includes a naphthalene-based water-reducing agent or a polycarboxylate water-reducing agent.

[0016] In some specific embodiments, the setting time regulating material includes alumina and / or calcium oxide.

[0017] In some specific embodiments, the strength-adjusting material comprises a first mixture or a second mixture; the first mixture comprises sodium sulfate and sodium nitrate; the second mixture comprises calcium nitrate and calcium chloride.

[0018] In some specific embodiments, the mass ratio of the sodium sulfate to the sodium nitrate is 20:(10~15).

[0019] In some specific embodiments, the mass ratio of calcium nitrate to calcium chloride is (15~22):(13~20).

[0020] In some specific embodiments, the condensation time regulating material includes alumina and calcium oxide, wherein the mass ratio of alumina to calcium oxide is 30:(25~35).

[0021] A second aspect of the present invention also provides the application of a curing agent in the reinforcement of silty soil foundation mixing piles.

[0022] Compared with the prior art, the present invention has the following beneficial effects: The curing agent of this invention includes an active material, a viscosity modifier, a workability modifier, a strength modifier, and a setting time modifier. When the active material is mixed with silt, it undergoes a hydration reaction under the influence of water. On one hand, the cementing hydrates produced by the hydraulic active material fully encapsulate and cement the soil particles; on the other hand, the expansive hydrates produced by the expansive active material compress and fill the voids between and within the soil particles. Through synergistic action, these two components ultimately form a dense, solidified soil structure, making it a compact and robust whole. The viscosity modifier is specifically designed to address adverse conditions such as high organic matter content, underground liquefiable sand layers, or dynamic water environments. By providing additional cohesion, it tightly encapsulates the active material and soil particles into a single unit, ensuring that the structure is not easily damaged by the environment before solidification. The main function of workability modifiers is to optimize construction performance, effectively reducing water consumption during the preparation of mixing piles and curing agents, making mixing pile construction more convenient and energy-efficient, while also protecting the drill bit. Strength modifiers can be evenly dispersed into the components of the solidified soil during mixing. Within the coating formed by viscosity modifiers, they enhance the strength of active cementitious materials, especially crucial for ensuring strength development in the early stages under harsh environmental conditions. Setting time modifiers are used to regulate the reaction rate, accelerating the release of heat of hydration in the hydration reaction of active cementitious materials. When the underground ambient temperature is low, their setting-promoting effect can rapidly promote hydration and release a large amount of heat energy, thereby effectively promoting the forming process of mixing piles and avoiding problems such as failure to form piles or poor pile quality.

[0023] In summary, the curing agent provided by this invention uses hydraulic active materials and expansive active materials as the main raw materials, combined with the synergistic effect of unique functional additives. It possesses functionality, enabling the curing agent and water to react and promote synergistic effects with the soil, silt, and solid waste being cured. This significantly improves the strength and other performance indicators of the cured soil, meeting the technical requirements for foundation strength and stability. It achieves rapid, efficient, and uniform curing of soft soil and silt, enhancing the mechanical properties and durability of the cured soil, and providing high-quality cured soil materials for infrastructure construction. Detailed Implementation

[0024] The present invention will be described below through specific embodiments. Those skilled in the art will understand that the specific embodiments described below are for illustrative purposes only and do not limit the scope of the invention in any way. Furthermore, in the following embodiments, unless otherwise specified, the reagents and equipment used are commercially available. If specific processing conditions and methods are not explicitly described in the following embodiments, conditions and methods known in the art can be used for processing.

[0025] This invention provides a curing agent for foundation reinforcement mixing piles, comprising the following raw materials in weight percentages: Active materials 89%~93%, viscosity modifiers 0.5%~1%, workability modifiers 0.2%~0.8%, strength modifiers 3%~5%, setting time modifiers 2%~5%; The active materials include hydraulic active materials and expandable active materials.

[0026] In this invention, the active material is a composite core system of hydraulic active material and intumescent active material, rather than a single material selection. The hydraulic active material possesses excellent hydration and cementing capabilities, while the intumescent active material generates a controllable volume expansion effect through hydration. When the active material is mixed with sludge, the hydration reaction is rapidly initiated under the stimulation of water within the system: On one hand, the hydraulic active material generates cementing hydrates through hydration. These hydrates have a three-dimensional network structure and possess extremely strong adhesive properties, allowing them to fully penetrate into the micropores on the surface of soil aggregates, achieving comprehensive encapsulation and tight cementation of the dispersed soil aggregates, and initially constructing the framework structure of the solidification system; on the other hand, the intumescent active material simultaneously hydrates to generate intumescent hydrates, producing a controllable volume expansion of 2%-4%. This expansion force effectively compresses the macroscopic voids between soil aggregates while filling the microscopic pores inside the soil aggregates, precisely compensating for the volume shrinkage (shrinkage rate ≤0.5%) generated during the hydration process of the hydraulic active material. Through the synergistic effect of "cemented skeleton construction - expansion pore filling", the two gradually eliminate various pore defects in the solidification system, and finally form a dense solidified soil structure without obvious pores, making the solidified product a dense and solid whole, laying the foundation for the excellent mechanical properties of solidified soil.

[0027] In some embodiments, the mass percentage of active material in the curing agent can be any one of 89%, 89.5%, 90%, 90.5%, 91%, 91.5%, 92%, 92.5%, and 93%, or a range between any two.

[0028] In this invention, by controlling the content of active materials in the curing agent within the aforementioned range, it is beneficial for the overall performance of the solidified soil to reach its optimal level. If the content of active materials in the curing agent is too high, it will lead to the failure of pile formation or poor pile formation effect under certain special working conditions, such as high-salt silt soil and high-organic-matter silt soil. If the content of active materials in the curing agent is too low, it will be difficult for the hydration active materials that coat the silt soil to fully bond, making it difficult for the solidified soil to form a whole.

[0029] In some embodiments, the mass percentage of viscosity modifier in the curing agent can be any one of 0.5%, 0.55%, 0.6%, 0.65%, 0.7%, 0.75%, 0.8%, 0.85%, 0.9%, 0.95%, and 1%, or a range between any two.

[0030] In this invention, by controlling the content of viscosity-regulating material in the curing agent within the aforementioned range, it is beneficial to adjust the viscosity of the curing agent slurry, facilitating grouting during the mixing pile construction process. Furthermore, it ensures that the curing agent slurry, after being uniformly mixed with the silt, forms a cohesive whole, effectively hydrating and avoiding the erosion effects of groundwater in the underground environment. If the content of viscosity-regulating material in the curing agent is too high, the curing agent slurry will be too thick, making grouting difficult; if the content of viscosity-regulating material is too low, the slurry will be too thin, easily leading to segregation and bleeding during the grouting process, affecting the ratio of the curing agent to the surrounding silt during the mixing pile process, and causing unevenness.

[0031] In some embodiments, the mass percentage of workability modifier in the curing agent can be any one of 0.2%, 0.25%, 0.3%, 0.35%, 0.4%, 0.45%, 0.5%, 0.55%, 0.6%, 0.65%, 0.7%, 0.75%, and 0.8%, or a range between any two.

[0032] When the workability modifier is a naphthalene-based water-reducing agent, the preferred mass percentage of the workability modifier is 0.8%.

[0033] When the workability modifier is a polycarboxylate superplasticizer, the preferred mass percentage of the workability modifier is 0.2%.

[0034] In this invention, by controlling the content of the workability modifier in the curing agent within the aforementioned range, it is beneficial to control the water-to-solid ratio during the curing agent slurry preparation process, thereby achieving the grouting process. If the content of the workability modifier in the curing agent is too high, it will cause the curing agent slurry to easily exhibit segregation and bleeding, making grouting difficult; if the content of the workability modifier in the curing agent is too low, it will cause the water-to-solid ratio of the slurry preparation to be difficult to meet the design requirements, resulting in water consumption exceeding the design requirements, and ultimately the overall performance of the resulting mixing pile will be difficult to meet the requirements.

[0035] In some embodiments, the mass percentage of the strength-modifying material in the curing agent can be any one of 3%, 3.2%, 3.5%, 3.8%, 4%, 4.2%, 4.5%, 4.8%, and 4%, or a range between any two.

[0036] In this invention, by controlling the content of the strength-regulating material in the curing agent within the aforementioned range, it is beneficial to rapidly increase the strength of the cured soil and achieve high bearing capacity of the mixing pile. If the content of the strength-regulating material in the curing agent is too high, it will lead to increased costs and the strength increase will not be significant; if the content of the strength-regulating material in the curing agent is too low, it will result in insufficient early strength or poor pile formation.

[0037] In some embodiments, the mass percentage of the setting time regulating material in the curing agent can be any one of 2%, 2.2%, 2.5%, 2.8%, 3%, 3.2%, 3.5%, 3.7%, 4%, 4.3%, 4.5%, 4.8%, and 5%, or a range between any two.

[0038] In this invention, by adjusting the setting time of the curing agent and regulating the content of the material within the aforementioned range, it is beneficial to rapidly form the mixing piles from the curing agent slurry and silt, avoiding interference from disturbances and groundwater in foundation engineering. If the content of the setting time regulating material in the curing agent is too high, the curing agent slurry will set too quickly, the hydration reaction will be too intense, and the resulting mixing pile will be brittle. If the content of the setting time regulating material in the curing agent is too low, the curing agent slurry will hydrate normally, making it difficult to achieve the requirement of rapid setting and early forming.

[0039] In some embodiments, the hydraulic active material includes at least one of cement, mineral powder, power plant slag, fly ash, red mud, and steel slag.

[0040] Alternatively, in some embodiments, the hydraulic active material may be at least one of silicate cement, sulfoaluminate cement, and aluminate cement.

[0041] In some embodiments, the expansive active material includes at least one of desulfurized gypsum, silica fume densifier, and calcium-based bentonite.

[0042] Alternatively, in some embodiments, the expansive active material may be at least one of ettringite-type expansive, magnesium oxide-type expansive, and gypsum-based expansive.

[0043] In this invention, the cementing hydrates generated by the hydraulic active material fully encapsulate and cement the soil particles; on the other hand, the expansive hydrates generated by the expansive active material squeeze and fill the gaps between and inside the soil particles. Through synergistic action, the two ultimately form a dense and solidified soil structure, making it a dense and firm whole.

[0044] In this invention, using the above-mentioned substances as active materials not only solves the problem of treating large amounts of waste soil such as silt, but also realizes the resource utilization of waste soil, reduces environmental damage, conforms to the current social and economic development trend of low carbon, environmental protection, green energy conservation, and improves engineering quality and safety; on the other hand, it will reduce dependence on traditional building materials, reduce environmental pollution, and promote sustainable development.

[0045] In some embodiments, the mass ratio of the hydraulic active material to the expandable active material is (90~95):(5~10). As an example, the mass ratio of the hydraulic active material to the expandable active material can be 90:10, 91:9, 92:8, 93:7, 94:6, and 95:5, etc.

[0046] In this invention, by controlling the mass ratio of hydraulic active material and expansive active material within the aforementioned range, it helps to achieve excellent comprehensive performance of the mixing pile in foundation reinforcement engineering, including compressive strength, bearing capacity, and impermeability coefficient. After the curing agent slurry is evenly mixed with the silt, its expansive hydration characteristics effectively fill the pores and internal spaces of the solidified soil, ultimately improving the impermeability coefficient of the mixing pile. If the content of hydraulic active material is too high, micro-cracks will appear in the mixing pile during the hydration and drying process, affecting its strength and impermeability coefficient; if the content of expansive active material is too high, the compressive strength will decrease.

[0047] In some embodiments, the silica fume densifier contains ≥95% silica by mass. There are no special limitations on the components in the silica fume densifier other than silica, as long as the silica by mass content is ≥95%.

[0048] In some embodiments, the viscosity modifier includes at least one of cellulose, dispersible powder, polyacrylamide, and xanthan gum.

[0049] Preferably, the viscosity modifier includes cellulose, dispersible powder, polyacrylamide, and xanthan gum.

[0050] Preferably, the mass ratio of the cellulose, the dispersible powder, the polyacrylamide, and the xanthan gum is 1:(0.8~1.3):(0.3~0.6):(0.8~1.3). As an example, the mass ratio of cellulose, dispersible powder, polyacrylamide, and xanthan gum can be any one of the following values ​​or a range between any two: 1:0.8:0.3:0.8, 1:0.8:0.5:1.3, 1:0.9:0.35:0.9, 1:0.9:0.6:0.9, 1:1.05:0.45:1.05, 1:0.95:0.48:1.25, 1:1.2:0.3:1.2, 1:1.2:0.55:1.2, 1:1.3:0.4:0.8, and 1:1.3:0.6:1.3.

[0051] Alternatively, in some embodiments, the viscosity-modifying material can also be a modified polymer material, specifically selected from one or more of acrylamide-acrylate copolymer, sodium carboxymethyl cellulose, and xanthan gum, designed specifically for unfavorable geological and environmental conditions such as high organic matter sludge (organic matter content ≥8%), underground liquefied sand layers (relative density Dr < 30%), or dynamic water environments (water flow velocity ≥ 0.3 m / s). In the above-mentioned complex environments, conventional solidification materials are prone to problems such as system collapse and molding failure due to insufficient adhesion to soil particles. However, the viscosity-modifying material of the present invention contains polar groups such as hydroxyl (-OH), carboxyl (-COOH), and amide (-CONH2) groups on its molecular chain, which can form stable hydrogen bonds with the hydroxyl groups on the surface of soil particles, and at the same time, interweave to form a three-dimensional network structure within the solidification system, significantly improving the cohesiveness of the system. Through this action, the viscosity modifier can tightly wrap the active material particles with the soil particles to form stable aggregates. The aggregate particle size can be controlled within 5-10 mm, ensuring that the solidification system can resist the damage caused by environmental factors such as water erosion and sand liquefaction before initial setting (initial setting time ≥ 2 h), ensuring the continuous and stable progress of the hydration reaction, and providing good conditions for subsequent strength development.

[0052] In some embodiments, the workability-adjusting material includes a water-reducing agent.

[0053] In some embodiments, the water-reducing agent includes a naphthalene-based water-reducing agent or a polycarboxylate water-reducing agent.

[0054] Alternatively, in some embodiments, the water-reducing agent can be a composite system of polycarboxylate-based high-efficiency water-reducing agent and polyacrylamide-based water-retaining agent, wherein the polycarboxylate-based high-efficiency water-reducing agent is preferably a product with a solid content ≥40%, and the water-retaining agent is preferably a polyacrylamide material with a water absorption rate ≥300 times, with a mass ratio of 3:1-5:1. The core function of this material is to optimize the construction performance of the curing system, specifically in three aspects: First, the polycarboxylate-based high-efficiency water-reducing agent can break the agglomeration state between active material particles through adsorption-dispersion, reducing the water consumption during mixing pile construction and curing agent slurry preparation by 18%-25% while ensuring the fluidity of the curing system meets construction requirements; second, the reduction in water consumption not only makes the slurry transport smoother during mixing pile construction but also improves the uniformity of mixing and reduces construction energy consumption; third, the water-retaining agent can firmly lock in the free water in the system, avoiding the phenomenon of slurry drying caused by excessive evaporation of water, reducing the adhesion of slurry to the mixing drill bit, effectively reducing the wear rate of the drill bit, protecting the drill bit, extending its service life, and thus reducing construction and maintenance costs.

[0055] In some embodiments, the strength-adjusting material comprises a first mixture or a second mixture.

[0056] In some embodiments, the first mixture includes sodium sulfate and sodium nitrate.

[0057] In some embodiments, the second mixture comprises calcium nitrate and calcium chloride.

[0058] In some embodiments, the mass ratio of the sodium sulfate to the sodium nitrate is 20:(10~15).

[0059] In some embodiments, the mass ratio of calcium nitrate to calcium chloride is (15~22):(13~20).

[0060] Alternatively, in some embodiments, the strength-adjusting material may be a composite system of nanoscale reinforcing materials and ultrafine mineral admixtures, wherein the nanoscale reinforcing materials are preferably nano-silica or nano-alumina with a particle size of 50-200 nm, and the ultrafine mineral admixtures are preferably those with a specific surface area ≥400 m². 2The material comprises ultrafine fly ash and finely ground slag powder at a mass ratio of 1:6 to 1:9. It exhibits excellent dispersibility, allowing for uniform dispersion throughout the solidified soil components via Brownian motion during mixing. Within the three-dimensional network structure formed by the viscosity-regulating material, it fully exerts its reinforcing effect: nanoscale reinforcing materials fill the micropores of the cementitious hydrates, acting as "nanocrystalline nuclei" to promote further growth and densification; ultrafine mineral admixtures undergo secondary hydration with calcium hydroxide produced by the hydration of hydraulic active materials, generating additional CSH cementitious products that synergistically enhance the system strength along with the primary hydration products. Especially in the early stages under harsh environmental conditions such as low temperature (≤10℃) and high humidity, conventional solidified soils often exhibit slow strength development. However, the strength-regulating material of this invention can increase the 3-day compressive strength of solidified soil by 35%-50% and the 7-day compressive strength by 25%-35%, effectively ensuring rapid early strength development and preventing structural instability due to insufficient early strength during construction.

[0061] In some embodiments, the setting time regulating material includes alumina and / or calcium oxide.

[0062] Preferably, the condensation time regulating material includes alumina and calcium oxide.

[0063] Preferably, the mass ratio of alumina to calcium oxide is 30:(25~35). As an example, the mass ratio of alumina to calcium oxide can be any one of 30:25, 30:26, 30:27, 30:28, 30:29, 30:30, 30:31, 30:32, 30:33 and 30:35 or a range between any two.

[0064] Alternatively, in some embodiments, the setting time regulating material may further comprise a composite temperature-controlled regulating system of a setting accelerator and a retarder in a mass ratio of (65~75):(25~35), wherein the setting accelerator is preferably calcium chloride or calcium sulfoaluminate, and the retarder is preferably citric acid or tartaric acid. The core function of this material is to precisely control the hydration reaction rate of the curing system. By adjusting the ratio of the setting accelerator to the retarder, the initial setting time of the curing system can be flexibly adjusted within the range of 2.5-7 hours, and the final setting time within the range of 4.5-11 hours. Simultaneously, the setting accelerator can accelerate the release of heat of hydration in the hydration reaction of the active cementitious material, increasing the heat of hydration release rate by 30%-40%. When the underground ambient temperature is low (≤10℃), the hydration reaction rate will decrease significantly. At this time, the setting time regulating material can quickly promote the hydration reaction and release a large amount of heat energy, raising the internal temperature of the solidification system by 6-10℃. This effectively accelerates the formation of cementitious hydrates and structural shaping, avoiding problems such as failure to form piles or poor pile quality caused by low temperature. When the ambient temperature is high (≥35℃), the proportion of retarding components can be appropriately increased to avoid problems such as insufficient mixing and internal defects caused by excessively rapid solidification of the solidification system, ensuring the stability of the solidification quality.

[0065] In some embodiments, to further enhance the environmental adaptability and durability of the curing agent, the present invention may selectively add 0.5%-2% of antifreeze components (such as ethylene glycol, urea) or 0.3%-1% of anticorrosive components (such as sodium benzoate, calcium nitrite) according to actual curing requirements. The antifreeze components can improve the freeze-thaw resistance of the cured soil in low-temperature freezing environments (≤-10℃). Tests have verified that after 5 freeze-thaw cycles, the compressive strength loss rate of the cured soil with added antifreeze components is ≤12%. The anticorrosive components can improve the corrosion resistance of the cured soil in saline-alkali environments (salt content ≥5%), ensuring that after immersion in a saline-alkali environment for 6 months, the compressive strength loss rate is ≤8%, significantly extending the service life of the cured soil.

[0066] In this invention, the preparation method of the curing agent is not specifically limited; the raw materials can be physically mixed evenly.

[0067] A second aspect of the present invention also provides the application of a curing agent in the reinforcement of silty soil foundation mixing piles.

[0068] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments. The embodiments of this application are only examples, and all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0069] In the following embodiments, the silica fume densifier comprises silica powder, wherein the silica content is 95 wt%; The dispersible binder powder was purchased from Tianjin Keyuan, model number 0520; The naphthalene-based water-reducing agent powder was purchased from Tianjin Feilong, model JFL-5. The polycarboxylate superplasticizer powder was purchased from Tianjin Feilong, model JFL-2.

[0070] Example 1 The curing agent provided in this embodiment is made from the following raw materials in the following mass percentages: The composition consists of 90% active material, 1% viscosity modifier, 0.6% workability modifier, 5% strength modifier, and 3.4% setting time modifier. The active material consists of a hydraulic active material and an intumescent active material in a mass ratio of 92:8. The hydraulic active material is composed of solid waste cement and fly ash in a 1:1 mass ratio: The expandable active material is desulfurized gypsum; The viscosity modifier is made from the following raw materials in parts by weight: 1 part cellulose, 1 part dispersible colloid powder, 0.5 parts polyacrylamide and 1 part xanthan gum; The workability modifier is a naphthalene-based water-reducing agent powder; The strength-regulating material is composed of sodium sulfate and sodium nitrate in a mass ratio of 2:1; The setting time regulating material consists of alumina and calcium oxide in a mass ratio of 30:30.

[0071] Example 2 The curing agent provided in this embodiment is made from the following raw materials in the following mass percentages: The composition consists of 89% active materials, 1% viscosity modifiers, 0.8% workability modifiers, 5% strength modifiers, and 4.2% setting time modifiers. The active material consists of a hydraulic active material and an intumescent active material in a mass ratio of 90:10. The hydraulic active material is composed of mineral powder, power plant slag, and red mud in a mass ratio of 1:1:1. The expandable active material is composed of desulfurized gypsum and silica fume densifier in a mass ratio of 1:1; The viscosity modifier is made from the following raw materials in parts by weight: 1 part cellulose, 0.8 parts dispersible colloid powder, 0.3 parts polyacrylamide, and 0.8 parts xanthan gum; The workability modifier is polycarboxylate superplasticizer powder; The strength-regulating material consists of calcium nitrate and calcium chloride in a mass ratio of 20:15; The setting time regulating material consists of alumina and calcium oxide in a mass ratio of 30:35.

[0072] Example 3 The curing agent provided in this embodiment is made from the following raw materials in the following mass percentages: The composition includes 93% active materials, 0.5% viscosity modifiers, 0.3% workability modifiers, 3% strength modifiers, and 3.2% setting time modifiers. The active material consists of a hydraulic active material and an intumescent active material in a mass ratio of 95:5. The hydraulic active material is composed of solid waste cement, mineral powder and steel slag in a mass ratio of 1:1:1:1; The expansive active material is composed of silica fume densifier and calcium-based bentonite in a mass ratio of 1:1; The viscosity modifier is made from the following raw materials in parts by weight: 1 part cellulose, 0.8 parts dispersible colloid powder, 0.6 parts polyacrylamide, and 1.3 parts xanthan gum; The workability modifier is a naphthalene-based water-reducing agent powder; The strength-regulating material is composed of sodium sulfate and sodium nitrate in a mass ratio of 20:15; The setting time regulating material consists of alumina and calcium oxide in a mass ratio of 30:25.

[0073] Comparative Example 1 The curing agent used is P.O42.5 ordinary Portland cement.

[0074] Performance testing In the following tests, the compressive strength was tested according to standard CJ T526-2018; In the following tests, the strength was tested according to standard CJ T526-2018; In the following tests, the impermeability coefficient was determined according to standard CJ T526-2018.

[0075] 1. Laboratory tests: (1) The curing agent in the examples and comparative examples was mixed with water to make a slurry with a water-cement ratio of 0.6. Then, the curing agent was mixed with a water-mixing pile (moisture content 43%) of a reservoir anti-seepage wall at a dosage of 12%, 16%, 20% and 24% respectively to form a mixing pile. The strength was tested after 7 days. The results are shown in Table 1.

[0076] Table 1. Comparison of indoor mixing piles (moisture content 43%) for seepage-resistant walls of a reservoir under the same conditions and with the same dosage.

[0077] (2) The curing agent in the examples and comparative examples was mixed with water to make a slurry with a water-cement ratio of 0.6. Then, the curing agent was mixed with a coastal silt (moisture content of 65%) at concentrations of 16%, 20% and 24% to form a mixing pile. The strength was tested after 7 days. The results are shown in Table 2.

[0078] Table 2. Comparison of mixing piles with the same conditions and dosage for silt (65% moisture content) in a coastal area.

[0079] (2) Field test The curing agents from Examples 1, 2, and Comparative Example 1 were mixed with water to form a slurry with a water-cement ratio of 0.6. The curing agent was then injected into the silt at a grouting pressure of 0.5 MPa, a drilling speed of 0.8 m / min, and a lifting speed of 0.6 m / min. The mixing process consisted of two sprays and four stirs to form mixing piles with a diameter of 0.6 m and a length of 10 m. Performance tests were then conducted. The dosage of the curing agent in Examples 1, 2, and Comparative Example 1 is shown in Table 3, and the performance test results are shown in Table 4.

[0080] Table 3. Dosage of curing agent in Examples 1, 2 and Comparative Example 1

[0081] Table 4 Performance test results of the curing agent mixing piles in Examples 1, 2 and Comparative Example 1

[0082] (3) The curing agent (GH) in Example 1 and the curing agent (SN) in Comparative Example 1 were mixed with water to form a slurry with a water-cement ratio of 0.6. Then, the curing agent was injected into the silt at different dosages according to the grouting pressure of 0.5 MPa, the drilling speed of 0.8 m / min and the lifting speed of 0.6 m / min. The number of spraying and stirring passes was two sprays and four stirring passes to form a mixing pile with a pile diameter of 0.6 m and a pile length of 10 m. Then, the performance of the mixing piles at different ages and different pile lengths was tested. The results are shown in Table 5.

[0083] In Table 5, GH-1 and SN-1 have a dosage of 12%; GH-2 and SN-2 have a dosage of 16%; GH-3 and SN-3 have a dosage of 20%; GH-4 and SN-4 have a dosage of 24%; 1m, 2m, 3m, 4m, 5m, 6m, 7m, 8m, 9m, and 10m represent the intensity from the surface to the ground at depths of 0-1m, 1-2m, 2-3m, 3-4m, 4-5m, 5-6m, 6-7m, 7-8m, 8-9m, and 9-10m, respectively.

[0084] In summary, the curing agent of this invention is a multi-component synergistic optimization system, specifically composed of active materials, viscosity modifiers, workability modifiers, strength modifiers, and setting time modifiers compounded in a specific mass ratio. Each component has complementary functions and synergistic effects, precisely addressing common technical pain points in the curing process of soft soil, silt, and various solid wastes, such as molding difficulties, insufficient early strength, poor environmental adaptability, and inadequate durability. It has significant advantages over existing single-function curing agents. Specifically, the curing agent provided by this invention uses hydraulic active materials and expansive active materials as core raw materials, combined with the synergistic effects of unique viscosity modifiers, workability modifiers, strength modifiers, and setting time modifiers, possessing comprehensive functionality and extremely strong environmental adaptability. Compared with existing technologies, the curing agent of this invention can drive a multi-dimensional interaction and synergistic effect among the curing agent, water, and the object being cured (soil, silt, solid waste), involving "hydration activation, cementation and agglomeration, expansion and densification, strength enhancement, and coagulation regulation." Through precise proportioning and functional synergy of each component, the strength and other performance indicators of the cured soil are significantly improved. This invention can meet the technical requirements for foundation strength and stability in different infrastructure construction scenarios such as highways, railways, ports, and airports. It achieves rapid, efficient, and uniform curing of soft soil and silt, successfully solving the technical problems of difficult curing and shaping of soft soil, low strength, and poor durability in complex environments. It significantly improves the mechanical properties and durability of the cured soil, providing high-quality and highly reliable cured soil materials for infrastructure construction, with broad application prospects and significant economic and social benefits.

[0085] Although preferred embodiments of the invention have been shown and described, it is conceivable that those skilled in the art can devise various modifications to the invention within the spirit and scope of the appended claims.

Claims

1. A curing agent for foundation reinforcement mixing piles, characterized in that, Raw materials including the following percentages by mass: Active materials 89%~93%, viscosity modifiers 0.5%~1%, workability modifiers 0.2%~0.8%, strength modifiers 3%~5%, setting time modifiers 2%~5%; The active materials include hydraulic active materials and expandable active materials.

2. The curing agent for foundation reinforcement mixing piles according to claim 1, characterized in that, The mass ratio of the hydraulic active material to the expandable active material is (90~95):(5~10); The hydraulic active material includes at least one of cement, mineral powder, power plant slag, fly ash, red mud, and steel slag; The expansive active material includes at least one of desulfurized gypsum, silica fume densifier, and calcium-based bentonite. The silica densifier contains ≥95% silica by mass.

3. The curing agent for foundation reinforcement mixing piles according to claim 1, characterized in that, The viscosity modifier includes at least one of cellulose, dispersible powder, polyacrylamide, and xanthan gum.

4. The curing agent for foundation reinforcement mixing piles according to claim 4, characterized in that, The viscosity modifiers include cellulose, dispersible powder, polyacrylamide, and xanthan gum; The mass ratio of the cellulose, the dispersible gum powder, the polyacrylamide, and the xanthan gum is 1:(0.8~1.3):(0.3~0.6):(0.8~1.3).

5. The curing agent for foundation reinforcement mixing piles according to claim 1, characterized in that, The workability-adjusting material includes a water-reducing agent; the water-reducing agent includes a naphthalene-based water-reducing agent or a polycarboxylate water-reducing agent.

6. The curing agent for foundation reinforcement mixing piles according to claim 1, characterized in that, The setting time regulating material includes alumina and / or calcium oxide.

7. The curing agent for foundation reinforcement mixing piles according to claim 6, characterized in that, The condensation time regulating material includes alumina and calcium oxide, and the mass ratio of alumina to calcium oxide is 30:(25~35).

8. The curing agent for foundation reinforcement mixing piles according to claim 1, characterized in that, The strength-adjusting material includes a first mixture or a second mixture; the first mixture includes sodium sulfate and sodium nitrate; the second mixture includes calcium nitrate and calcium chloride.

9. The curing agent for foundation reinforcement mixing piles according to claim 8, characterized in that, The mass ratio of sodium sulfate to sodium nitrate is 20:(10~15). The mass ratio of calcium nitrate to calcium chloride is (15~22):(13~20).

10. The application of the curing agent for foundation reinforcement mixing piles according to any one of claims 1 to 9 in the reinforcement mixing piles of silty soil foundations.

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