A high-water content soft soil solidification material and its preparation method and application

Abstract

The present invention relates to a kind of high-water content soft soil solidification material and its preparation method and application, the high-water content soft soil solidification material is measured by mass percentage, including cement gelling material 90%-10%, alkali-activated gelling material 10%-90% and acrylate gelling material 0-1%; wherein, cement gelling material can play the role of water absorption, alkali-activated gelling material plays the role of drainage, acrylate gelling material plays the role of water retention, after synergistic chemical modification, while being able to quickly reduce the silt moisture content, ettringite, hydrated calcium silicate, hydrated calcium aluminate and hydrated calcium silicate aluminate and other gelling materials are produced, thereby improving the strength of solidified soil. Compared with existing curing agents, the curing material of the present invention has the advantages of high curing strength, short time, low cost and good water resistance, can effectively improve the bearing capacity of soft foundation, and meet the needs of on-site in-situ curing.

Description

Technical Field

[0001] The present invention belongs to the technical field of civil engineering and building materials, and specifically relates to a soft soil solidification material, and in particular to a high-water content soft soil solidification material, a preparation method thereof, and an application thereof. Background Art

[0002] my country's coastal mudflats are vast. With the rapid development of the economy and infrastructure, land resources are becoming increasingly scarce. Consequently, numerous projects, including housing, municipal roads, utility corridors, power tunnels, and sewage networks, have had to be constructed on soft soils. This is particularly true in coastal areas, where soft soils generally exhibit unfavorable properties such as high water content, a large porosity, low strength, high compressibility, and poor permeability, making them difficult to use directly. Therefore, artificial treatment is often required to improve the strength and bearing capacity of the soft soil to meet construction requirements. This not only increases construction costs but, if improperly treated, can also seriously impact the stability and safety of the project.

[0003] During the construction of engineering projects, engineering problems caused by weak foundations often occur. For example, due to the inability of machinery and vehicles to enter the site smoothly in the early stages, most projects still use the traditional brick slag replacement method to form mechanical operating platforms, construction access roads, and material storage areas. This is not environmentally friendly and is greatly affected by regional factors, which will additionally increase the cost of the project. In addition, due to the special characteristics of the stratum, problems such as instability or overturning of foundation pit excavation support, silting of foundation pits, and ground collapse and settlement frequently occur, greatly increasing the difficulty of engineering construction. Therefore, how to efficiently deal with engineering soft soil is an unavoidable problem during project construction.

[0004] Among the many soft foundation treatment methods, solidification / stabilization technology is an effective method that can achieve in-situ solidification and treatment of silt, avoiding dredging and transportation and purchasing earth for backfill. The essence of soil solidification is to strengthen the structural connection between soil particles through physical, chemical, or biological methods, thereby achieving the purpose of solidifying the soil. Examples include traditional cement-lime solidification, slag silicate solidification, ionic solution solidification, enzyme solidification, and microbial solidification. However, these methods generally have disadvantages such as low solidification efficiency, high solidification costs, and limited applicability to different soil types. Currently, most sites still use a mixture of cement and fly ash as a solidification material. Although the cost is relatively low, the dosage is high, the solidification time is long, and the overall treatment effect is poor.

[0005] Furthermore, most published literature only provides indoor curing strength data. Given the higher moisture content and uneven mixing of silt on site, these results can differ significantly from indoor curing results. Indoor strength results often fail to meet the actual bearing capacity requirements of the field. Therefore, it is necessary to develop a cost-effective, environmentally friendly soft soil curing material with high curing strength that can meet the requirements of in-situ curing. Summary of the Invention

[0006] Based on the technical problems existing in the prior art, the purpose of the present invention is to provide an economical, efficient and environmentally friendly solidification material that can reduce the dosage and solidification cost, while improving the solidification strength and shortening the solidification time, so as to overcome the problems of high water content, high clay mineral content and high organic matter content of silt-like soft soil and meet the needs of on-site in-situ solidification.

[0007] To achieve the above-mentioned purpose, the solidification material provided by the present invention uses active waste slag (blast furnace slag, fly ash, silica fume, natural volcanic ash, steel slag, etc.) as the main raw materials, and is composited with silicate cement binder. While exerting its own water absorption properties, it quickly hydrates and consolidates silty soil with high moisture content, fine particles and high consistency, effectively improving the solidification strength of soft soil, and is environmentally friendly and economical.

[0008] In order to achieve the above object, the technical solution of the present invention is as follows:

[0009] A high-water content soft soil solidification material, the solidification material comprising a cement gelling material, an alkali-activated gelling material and an acrylate gelling material, wherein the solidification material comprises, by mass percentage, 90%-10% of the cement gelling material, 10%-90% of the alkali-activated gelling material, and 0-1% of the acrylate gelling material; the content of the acrylate gelling material is greater than 0;

[0010] The cementitious material comprises, by mass percentage:

[0011] Portland cement 10%-80%

[0012] Stone powder 5%-60%

[0013] Gypsum 5%-30%;

[0014] The alkali-activated gelling material comprises, by mass percentage:

[0015] Gelling component 30%-95%

[0016] Alkali activator 5%-40%;

[0017] The acrylate gel material comprises, by mass percentage:

[0018] Acrylate 0-50%

[0019] Polyaluminium chloride 100%-50%;

[0020] The moisture content of the high-moisture soft soil or high-moisture slag soil is above 70%; the moisture content of the high-moisture soft soil or high-moisture slag soil is reduced by more than 20% after being solidified by the solidifying material for 1 day.

[0021] In some embodiments, the solidifying material comprises the following raw materials by mass percentage: 80%-20% cement gelling material, 20%-80% alkali-activated gelling material, and 0-1% acrylate gelling material.

[0022] In some embodiments, the stone powder in the cementitious material is at least one of natural stone powder, construction waste powder, and quartz powder.

[0023] In some embodiments, the stone powder is at least one of natural stone powder and construction waste powder; the natural stone powder is produced during the processing of mineral rocks or is stone powder directly ground from waste materials; the main components of the construction waste powder are concrete and bricks and tiles, and are particles with a particle size of less than 75 μm that are produced during the preparation of recycled aggregates from construction waste or are directly ground from them.

[0024] In some embodiments, the gypsum is at least one of anhydrous gypsum, hemihydrate gypsum, and dihydrate gypsum.

[0025] In some embodiments, the gypsum is at least one of industrial by-product gypsums such as desulfurized gypsum, phosphogypsum, and titanium gypsum.

[0026] More preferably, the gypsum is one or more of anhydrous gypsum or hemihydrate gypsum.

[0027] In some embodiments, the gelling component is at least one of blast furnace slag, fly ash, silica fume, natural pozzolana, and steel slag.

[0028] In some embodiments, the alkali activator is at least one of quicklime, sodium carbonate, sodium silicate, sodium metaaluminate, and sodium sulfate.

[0029] In some embodiments, the acrylate is at least one of magnesium acrylate, sodium acrylate, and calcium acrylate.

[0030] In some embodiments, the polyaluminum chloride (PAC) is in the form of a solid powder.

[0031] In some embodiments, the high-moisture content soft soil has a moisture content of 70%-90%.

[0032] The present invention also provides a method for preparing a high-water content soft soil solidification material according to any of the above-mentioned embodiments, the method comprising the following steps: uniformly mixing the cement gelling material, alkali-activated gelling material and acrylate gelling material in corresponding mass proportions and grinding them to a size of 200 mesh or above, wherein particles with a particle size of less than 10 μm account for more than 30%, thereby obtaining the obtained material.

[0033] The present invention also provides an application of the high-water content soft soil solidification material of any of the above-mentioned embodiments, specifically: using the solidification material as a solidifying agent for solidifying soft soils such as soft clay, silty soil, silt, and excavated soil such as sandy soil, clay soil, silty clay, sandy clay soil, and collapsible soil.

[0034] Specifically, during actual use of the high-water content soft soil solidification material, the powdered solidification material can be directly mixed with the silt soft soil, or the solidification material can be mixed with water into a slurry and then evenly mixed with the soft soil.

[0035] In some embodiments, the method for using the solidifying material to solidify high-water content soft soil is: 3 Mix the solidifying material with the high moisture content soft soil at a dosage of 50-150kg / m 3 The solidifying material is mixed with water to form a slurry and then mixed evenly with the soft soil.

[0036] Compared with the prior art, the present invention has the following beneficial effects:

[0037] Silt soft soil, excavated debris, etc. have the characteristics of high water content, fine particles, and are difficult to handle. Based on this, the curing material of the present invention includes a compound of three materials: cement gelling material, alkali-activated gelling material and acrylate gelling material. Among them, the cement gelling material first plays a role in absorbing water during the hydration process, and then the alkali-activated gelling material plays a role in drainage, and the acrylate gelling material plays a role in retaining water. After synergistic chemical modification, it can quickly reduce the water content of the silt while producing gelling substances such as ettringite, hydrated calcium silicate, hydrated calcium aluminate and hydrated calcium silicate aluminate, thereby improving the strength of the cured soil.

[0038] Specifically, cement binder is composed of silicate cement, stone powder and gypsum. The tricalcium silicate (C3S), dicalcium silicate (C2S), tricalcium aluminate (C3A) and other substances in the cement undergo hydration reaction to generate calcium silicate hydrate (CSH), ettringite (AFt) and Ca(OH)2, which quickly consume the moisture in the sludge while obtaining initial strength. The addition of gypsum is on the one hand to delay the setting of cement and prevent the cementitious substances generated by the violent hydration reaction from adhering to the cement particles, thereby hindering the hydration reaction. On the other hand, it can prevent the existing ettringite crystals from being converted into monosulfide calcium sulfoaluminate hydrate (AFm) after the gypsum in the cement is consumed. Stone powder mainly acts as a fine aggregate in the cement binder to play a skeleton structure role, strengthen the bonding between the cementitious substances and the sludge particles, and improve the curing strength.

[0039] The gelling components in alkali-activated cementitious materials are highly active. Under the action of the alkali activator, the silicon-oxygen and aluminum-oxygen bonds in the glassy structure of the gelling components break, and then undergo a polycondensation reaction to form a gel phase of calcium silicate hydrate, calcium aluminate hydrate, and calcium aluminosilicate hydrate. These gels fill the pores within the silt and, as the alkali-activated reaction progresses, gradually encapsulate the silt particles, further reducing the moisture content and increasing the structural strength of the solidified soil. During the alkali-activated reaction, water serves only as a medium and is not consumed. Due to the excellent water resistance of the alkali-activated cementitious materials, water is gradually expelled during the solidification process. The formation of alkali-activated cementitious materials ensures the improvement and stability of the later-stage strength of the solidified silt soil under high moisture content. Quicklime, sodium carbonate, sodium silicate, sodium metaaluminate, and sodium sulfate, acting as alkali activators, can activate the activity of the gelling components individually or in combination to produce a synergistic effect. In particular, a combined alkali-activated and sulfate-activated system significantly enhances the effectiveness of the alkali-activated reaction. In addition, the small amount of sodium hydroxide produced by the alkaline activator can catalyze the hardening of cement in cementitious materials, causing the aluminosilicate in the cement to form sodium silicate and sodium metaaluminate, which further react with calcium hydroxide to form hydrated silicon and calcium aluminate, prompting the cement to harden and regenerate sodium hydroxide, which continues to catalyze the next round of reactions. Cementitious components such as blast furnace slag, fly ash, and silica fume, under the combined action of acrylates, can also promote the early hydration of cement, producing hydration products that fill the pores of silt soil.

[0040] Acrylate gel material is formed by the reaction of acrylate and polyaluminum chloride. Magnesium acrylate, sodium acrylate or calcium acrylate are intricately interwoven with polyaluminum chloride to form a network of composite polymer gels, which have the effect of retaining water without undergoing hydrolysis or other decomposition reactions. This ensures the complexation under high water content and maintains the long-term strength of solidified silt soil under water content. Calcium acrylate can also promote the formation of early ettringite (AFt) in cement binder materials, promote the continuous hydrolysis of tricalcium silicate (C3S), inhibit the transformation of AFt into monosulfur-type hydrated calcium sulfoaluminate (AFm), avoid the nucleation and precipitation of Ca(OH)2, and improve the dispersibility of cement paste and the Ca content in the liquid phase. 2+ Concentration, making hydration more complete. At the same time, acrylates react with Ca in cement binder and alkali activated binder 2+ Complexation occurs, firmly adsorbed on the surface of sludge particles, and improves the interaction between interfaces.

[0041] The present invention utilizes the compounding and synergistic effects of three materials: cement binder, alkali-activated binder, and acrylate gel. These materials not only utilize their inherent water absorption properties but also expel internal moisture, maintaining a trace amount of moisture to ensure rapid hydration of the solidified material and consolidate high-moisture-content, fine-grained, and high-consistency silty soils. This continuously improves the solidification strength, effectively overcoming the challenges of in-situ solidification of high-moisture-content silts and avoiding the problems of traditional solidification materials that only absorb water and thus fail to increase subsequent strength and crack the solidified soil. Furthermore, grinding further accelerates the hydration reaction process.

[0042] Compared with traditional curing agents, the curing material of the present invention has the advantages of high curing strength, short curing time and low cost. For high-moisture sludge, the moisture content can be reduced by more than 20% after curing for 1 day, and the bearing capacity reaches more than 120KPa after curing for 7 days, meeting the needs of on-site in-situ curing. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Figure 1 This is a graph showing the unconfined compressive strength of high-water content sludge after 3 and 7 days of solidification at different dosages of the solidification material in Example 1 of the present invention;

[0044] Figure 2 This is a diagram showing the water seepage condition of the curing material after in-situ curing in Example 1 of the present invention;

[0045] Figure 3 This is a diagram of the on-site coring process of the area after the curing material is in-situ cured in Example 1 of the present invention;

[0046] Figure 4 This is a graph showing the unconfined compressive strength of high-moisture sludge after 3 and 7 days of solidification at different dosages of the solidification material in Example 2 of the present invention;

[0047] Figure 5 This is a graph showing the unconfined compressive strength of high-moisture sludge after 3 and 7 days of solidification at different dosages of the solidification material in Example 3 of the present invention;

[0048] Figure 6 This is a graph showing the unconfined compressive strength of high-moisture sludge after 3 and 7 days of solidification at different dosages of the solidification material in Example 4 of the present invention;

[0049] Figure 7 This is a graph showing the unconfined compressive strength of high-moisture sludge after curing for 3 days and 7 days at different dosages of the curing material in comparative example 1 of the present invention. DETAILED DESCRIPTION

[0050] To make the above-mentioned objects, features, and advantages of the present invention more readily apparent, specific embodiments of the present invention are described in detail below with reference to the accompanying drawings. The following description sets forth numerous specific details to facilitate a full understanding of the present invention. However, the present invention can be implemented in many other ways than those described herein, and those skilled in the art may make similar modifications without departing from the scope of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0051] The present invention aims to provide a high-water content soft soil solidification material, which specifically comprises a cement gelling material, an alkali-activated gelling material and an acrylate gelling material; in terms of mass percentage, the material comprises 90%-10% of the cement gelling material, 10%-90% of the alkali-activated gelling material and 0-1% of the acrylate gelling material; the content of the acrylate gelling material is greater than 0.

[0052] The cement gelling material comprises, by mass percentage, 10%-80% of Portland cement, 5%-60% of stone powder and 5%-30% of gypsum; the alkali-activated gelling material comprises, by mass percentage, 30%-95% of gelling components and 5%-40% of alkali activator; and the acrylate gelling material comprises, by mass percentage, 0-50% of acrylate and 100%-50% of polyaluminium chloride.

[0053] Preferably, the stone powder in the cementitious material is at least one of natural stone powder, construction waste powder, and quartz powder; natural stone powder is produced during the processing of mineral rocks or is directly ground from waste materials; the main components of construction waste powder are concrete and bricks and tiles, and are particles with a particle size of less than 75 μm that are produced in the process of preparing recycled aggregates from construction waste or are directly ground from them; the stone powder not only exerts a micro-aggregate effect but also has a certain activity effect, thereby improving the compactness of silt soil.

[0054] The gypsum in the cementitious material is at least one of anhydrous gypsum, hemihydrate gypsum, and dihydrate gypsum, preferably industrial by-product gypsum such as desulfurized gypsum, phosphogypsum, and titanium gypsum. Gypsum is used to slow the setting of cement, preventing the vigorous hydration reaction from forming cementitious materials that adhere to the cement particles and hinder the hydration reaction. It also prevents the conversion of existing ettringite crystals into monosulfide calcium sulfoaluminate hydrate after the gypsum in the cement is consumed. Furthermore, the use of anhydrous gypsum or hemihydrate gypsum can help consume some free water.

[0055] The cementitious component in the alkali-activated cementitious material is at least one of blast furnace slag, fly ash, silica fume, natural volcanic ash, and steel slag. The cementitious component has high activity. Under the action of alkaline activators such as quicklime, sodium carbonate, sodium silicate, sodium aluminate, and sodium sulfate, the silicon-oxygen network structure layer, that is, the "protective film" on the surface of the glass in the cementitious component is destroyed, thereby generating very stable hydration products such as hydrated calcium silicate and zeolites, which have excellent mechanical properties, water resistance, and corrosion resistance.

[0056] The acrylate in the acrylate gel material is one or more of magnesium acrylate, sodium acrylate, and calcium acrylate. Polyaluminium chloride (PAC) is a solid powder, an inorganic high molecular polymer, easily soluble in water, and has properties such as adsorption, coagulation, and precipitation. After being dissolved in water, polyaluminium chloride undergoes a polymerization reaction with magnesium acrylate, sodium acrylate, or calcium acrylate under a high water content to form a gel phase material, thereby improving the curing strength. A trace amount of acrylate gel material can maintain a certain amount of moisture in the micropores inside the solidified soil without affecting the water absorption of cement binder materials and the drainage of alkali-activated binder materials, thereby preventing the water from being absorbed and discharged in a short period of time and blocking the infiltration channel, thereby hindering the subsequent reaction.

[0057] The method for preparing the high-moisture content soft soil solidification material comprises the following steps: uniformly mixing a cement binder, an alkali-activated binder, and an acrylate gel material in appropriate mass proportions and grinding them to a size of 200 mesh or larger, with particles having a size of less than 10 μm accounting for at least 30%. By grinding the mixed solidification materials, the fine particle content is increased, which helps accelerate the hydration reaction and alkali-activated reaction, thereby improving the solidification effect.

[0058] In the following examples and comparative examples, the sludge was obtained from a project in Binhaiwan New Area, Dongguan City. The area is a typical mudflat stratum with a maximum thickness of 15m. The initial moisture content was above 70%, the liquid limit was 56.5%, the plastic limit was 36.2%, and the density was 1.55g / cm 3 The porosity is 68%, with a porosity ratio of 2.14. The particle size analysis results are Dv(10)=1.678μm, Dv(50)=8.834μm, and Dv(90)=24.886μm. The gradation curve is discontinuous. The main chemical components are: SiO2 accounts for 62.8%, Al2O3 accounts for 20.8%, Fe2O3 accounts for 7.2%, and K2O accounts for 3.3%. The main mineral components are: quartz 47.7%, illite 22.2%, kaolinite 19.7%, montmorillonite 3.2%, chlorite 0.5%, and albite 3.3%.

[0059] Example 1

[0060] A high-water-content soft soil solidification material comprises a cement binder, an alkali-activated binder, and an acrylate gel material in the following mass percentages: 51% cement binder, 48.5% alkali-activated binder, and 0.5% acrylate gel material. The cement binder comprises the following raw materials by mass percentage: 68.6% PO42.5 cement, 15.7% limestone powder, and 15.7% desulfurized gypsum; the alkali-activated binder comprises the following raw materials by mass percentage: 82.5% gelling component and 17.5% alkali activator; the gelling component comprises the following raw materials by mass percentage: 61.9% blast furnace slag, 20.6% fly ash, 4.1% quicklime, 4.1% sodium carbonate, 4.1% sodium silicate, 3.1% sodium metaaluminate, and 2.1% sodium sulfate; and the acrylate gel material comprises the following raw materials by mass percentage: 40% acrylate and 60% polyaluminium chloride. The cement gelling material, alkali-activated gelling material and acrylate gelling material are mixed uniformly according to the above mass ratio and ground to above 200 mesh, wherein particles with a particle size of less than 10 μm account for 40%, thereby obtaining the final high-moisture content soft soil solidification material.

[0061] The solidified material and sludge with a water content of 77% were mixed at a rate of 50 kg / m 3 , 75kg / m 3 , 100kg / m 3 、125kg / m 3 、150kg / m 3 The five dosages were mixed and stirred evenly, then poured into a mold (size 70.7*70.7*70.7mm), covered and naturally cured at room temperature. The test showed that the moisture content of the cured specimen was 56% after 1 day, which means that the moisture content of the sludge decreased by 21% after 1 day of curing. Figure 1 As shown, the 3d average compressive strength of the cured specimens at the five dosages were 0.19MPa, 0.55MPa, 0.97MPa, 1.19MPa, and 2.03MPa, respectively; the 7d average compressive strength were 0.30MPa, 0.68MPa, 1.31MPa, 2.00MPa, and 2.63MPa, respectively.

[0062] The curing material is used for on-site in-situ curing treatment, with a dosage of 100kg / m 3 , water-cement ratio 1:1, curing area 30m long, 8m wide, curing depth 3m, using a powerful mixing head to mix the slurry curing material with the on-site silt and stir evenly, after 7 days the composite bearing capacity was tested. The pressure plate test results show that the composite bearing capacity of the in-situ curing area is 150KPa, which meets the bearing capacity requirement of 120KPa. Figure 2 As shown in the figure, it is a regional water seepage situation diagram during the on-site in-situ solidification process. Figure 3The figure shows the process of coring in the area after in-situ solidification, from which a complete core sample can be taken.

[0063] Example 2

[0064] A high-water-content soft soil solidification material comprises a cement gelling material, an alkali-activated gelling material and an acrylate gelling material in the following mass percentages: 54% cement gelling material, 45.5% alkali-activated gelling material and 0.5% acrylate gelling material; wherein the cement gelling material comprises the following raw materials in mass percentages: 74.1% PO42.5 cement, 9.2% limestone powder and 16.7% desulfurized gypsum; the alkali-activated gelling material comprises the following raw materials in mass percentages: 87.9% gelling component and 12.1% alkali activator; wherein the gelling component comprises, by mass percentage, 65.9% blast furnace slag, 11.0% fly ash, 11% silica fume, 2.2% quicklime, 2.2% sodium carbonate, 2.2% sodium silicate, 3.3% sodium metaaluminate and 2.2% sodium sulfate; and the acrylate gelling material comprises the following raw materials in mass percentages: 40% acrylate and 60% polyaluminium chloride. The cement gelling material, alkali-activated gelling material and acrylate gelling material are mixed uniformly according to the above mass ratio and ground to above 200 mesh, wherein particles with a particle size of less than 10 μm account for 40%, thereby obtaining the final high-moisture content soft soil solidification material.

[0065] The solidified material and sludge with a water content of 77% were mixed at a rate of 50 kg / m 3 , 75kg / m 3 、100kg / m 3 、125kg / m 3 、150kg / m 3 The five dosages were mixed and stirred evenly, then poured into a mold (size 70.7*70.7*70.7mm), covered and naturally cured at room temperature. The test showed that the moisture content of the cured specimen was 55% after 1 day, that is, the moisture content of the sludge decreased by 22% after 1 day of curing. Figure 4 As shown, the 3d average compressive strength of the cured specimens at the five dosages were 0.20MPa, 0.51MPa, 0.99MPa, 1.16MPa, and 1.83MPa, respectively; the 7d average compressive strength were 0.28MPa, 0.69MPa, 1.36MPa, 1.74MPa, and 2.16MPa, respectively.

[0066] Example 3

[0067] A high-water-content soft soil solidification material comprises a cement gelling material, an alkali-activated gelling material and an acrylate gelling material in the following mass percentages: 40% cement gelling material, 59.5% alkali-activated gelling material and 0.5% acrylate gelling material; wherein the cement gelling material comprises the following raw materials in mass percentages: 75.0% PO42.5 cement, 12.5% ​​limestone powder and 12.5% ​​desulfurized gypsum; the alkali-activated gelling material comprises the following raw materials in mass percentages: 84.0% gelling component and 16.0% alkali activator; wherein the gelling component comprises, by mass percentage, 67.2% blast furnace slag, 8.4% fly ash, 8.4% steel slag, 3.4% quicklime, 3.4% sodium carbonate, 3.4% sodium silicate, 3.3% sodium metaaluminate and 2.5% sodium sulfate; and the acrylate gelling material comprises the following raw materials in mass percentages: 40% acrylate and 60% polyaluminium chloride. The cement gelling material, alkali-activated gelling material and acrylate gelling material are mixed uniformly according to the above mass ratio and ground to above 200 mesh, wherein particles with a particle size of less than 10 μm account for 35%, thereby obtaining the final high-moisture content soft soil solidification material.

[0068] The solidified material and sludge with a water content of 77% were mixed at a rate of 50 kg / m 3 , 75kg / m 3 、100kg / m 3 、125kg / m 3 、150kg / m 3 The five dosages were mixed and stirred evenly, then poured into a mold (size 70.7*70.7*70.7mm), covered and naturally cured at room temperature. The test showed that the moisture content of the cured specimen was 57% after 1 day, that is, the moisture content of the sludge decreased by 20% after 1 day of curing. Figure 5 As shown, the 3d average compressive strength of the cured specimens at the five dosages were 0.16MPa, 0.36MPa, 0.89MPa, 0.96MPa, and 1.91MPa, respectively; the 7d average compressive strength were 0.21MPa, 0.59MPa, 0.93MPa, 1.97MPa, and 2.14MPa, respectively.

[0069] Example 4

[0070] A high-water content soft soil solidification material comprises a cement gelling material, an alkali-activated gelling material and an acrylate gelling material in the following mass percentages: 63% cement gelling material, 36.7% alkali-activated gelling material and 0.3% acrylate gelling material; wherein the cement gelling material comprises the following raw materials in mass percentages: 71.4% PO42.5 cement, 14.3% construction waste powder and 14.3% phosphogypsum; the alkali-activated gelling material comprises the following raw materials in mass percentages: 84.5% gelling component and 15.5% alkali activator; wherein the gelling component comprises, by mass percentage, 54.5% blast furnace slag, 13.6% fly ash, 16.4% steel slag, 2.7% quicklime, 5.4% sodium carbonate, 4.1% sodium silicate and 3.3% sodium metaaluminate; and the acrylate gelling material comprises the following raw materials in mass percentages: 33.3% acrylate and 66.7% polyaluminium chloride. The cement gelling material, alkali-activated gelling material and acrylate gelling material are mixed uniformly according to the above mass ratio and ground to above 200 mesh, wherein particles with a particle size of less than 10 μm account for 35%, thereby obtaining the final high-moisture content soft soil solidification material.

[0071] The solidified material and sludge with a water content of 77% were mixed at a rate of 50 kg / m 3 , 75kg / m 3 、100kg / m 3 、125kg / m 3 、150kg / m 3 The five dosages were mixed and stirred evenly, then poured into a mold (size 70.7*70.7*70.7mm), covered and naturally cured at room temperature. The test showed that the moisture content of the cured specimen was 52% after 1 day, that is, the moisture content of the sludge decreased by 25% after 1 day of curing. Figure 6 As shown, the 3d average compressive strength of the cured specimens at the five dosages were 0.11MPa, 0.43MPa, 0.72MPa, 0.97MPa, and 1.57MPa, respectively; the 7d average compressive strength were 0.23MPa, 0.57MPa, 0.94MPa, 1.73MPa, and 1.91MPa, respectively.

[0072] Comparative Example 1

[0073] A high-water content soft soil solidification material is prepared by grinding PO42.5 cement until particles with a diameter of less than 10 μm account for 40% of the total volume, thereby obtaining the final high-water content soft soil solidification material.

[0074] The solidified material and sludge with a water content of 77% were mixed at a rate of 50 kg / m 3 , 75kg / m 3 、100kg / m 3 、125kg / m 3 、150kg / m3 The five dosages were mixed and stirred evenly, then poured into the mold (size 70.7*70.7*70.7mm), covered and naturally cured at room temperature. Figure 7 As shown, the 3d average compressive strength of the cured specimens at the five dosages were 0.15MPa, 0.26MPa, 0.50MPa, 0.67MPa, and 0.84MPa, respectively; the 7d average compressive strength were 0.17MPa, 0.43MPa, 0.67MPa, 0.84MPa, and 1.24MPa, respectively.

[0075] Comparative Example 2

[0076] A high-moisture content soft soil solidification material is composed of a cement gelling material and an alkali-activated gelling material, and does not contain an acrylate gelling material. The cement gelling material and the alkali-activated gelling material are mixed in the same proportions as in Example 1. The cement gelling material and the alkali-activated gelling material are uniformly mixed according to the mass ratios in Example 1 and ground to a size of 200 mesh or larger, wherein particles having a particle size of less than 10 μm account for 40%, thereby obtaining a final high-moisture content soft soil solidification material.

[0077] The solidified material and sludge with a water content of 77% were mixed at a rate of 50 kg / m 3 , 75kg / m 3 、100kg / m 3 、125kg / m 3 、150kg / m 3 The five different dosages were mixed and stirred uniformly before being poured into a mold (70.7*70.7*70.7mm), covered with a film, and naturally cured at room temperature. Testing showed that the average 3-day compressive strength of the cured specimens at the five dosages was 0.16MPa, 0.44MPa, 0.68MPa, 0.81MPa, and 1.61MPa, respectively; and the average 7-day compressive strength was 0.26MPa, 0.60MPa, 1.10MPa, 1.62MPa, and 2.23MPa, respectively.

[0078] Comparative Example 3

[0079] A high-moisture content soft soil solidification material is provided, comprising an alkali-activated cementitious material in the following mass percentages: 61.9% blast furnace slag, 20.6% fly ash, 4.1% quicklime, 4.1% sodium carbonate, 4.1% sodium silicate, 3.1% sodium metaaluminate, and 2.1% sodium sulfate (the same proportions as the alkali-activated cementitious material in Example 1). The alkali-activated cementitious material is uniformly mixed in the above mass proportions and ground to a size of at least 200 mesh, wherein particles having a particle size of less than 10 μm account for 40%, thereby obtaining a final high-moisture content soft soil solidification material.

[0080] The solidified material and sludge with a water content of 77% were mixed at a rate of 50 kg / m 3 , 75kg / m3 , 100kg / m 3 、125kg / m 3 、150kg / m 3 The five different dosages were mixed and stirred thoroughly before being poured into a mold (70.7 x 70.7 x 70.7 mm), covered with a film, and naturally cured at room temperature. Testing showed that the cured specimens with all five dosages did not harden after 3 or 7 days, indicating no cured strength.

[0081] From the results of Examples 1 to 4, it can be seen that the curing effect of the present invention is significantly better than that of Comparative Example 1, and is generally better than that of Comparative Example 2. 3 The curing strength of Example 1 is 1.5-2.4 times that of Comparative Example 1. Compared with Example 1, under the conditions of natural curing at room temperature and the same dosage, the 3d compressive strength of Comparative Example 2 decreased by 15.8%, 20%, 29.9%, 31.9%, and 20.7%, respectively, and the 7d compressive strength decreased by 13.3%, 11.8%, 16%, 19%, and 15.2%, respectively. The 3d compressive strength decreased significantly under natural curing at room temperature, especially at 100kg / m 3 and 125kg / m 3 The two dosages reached 30% and above, while 50kg / m 3 , 75kg / m 3 、150kg / m 3 The strength reductions at the three dosage levels are relatively small. This is because the curing strength is inherently low at lower dosages. At higher dosages, the curing strength is inherently high, making the effect of the film coating less noticeable. The 7-day compressive strength decreases less than the 3-day compressive strength. This is because, although the film coating is used for natural room temperature curing, the moisture within the cured sludge inevitably evaporates as the curing time increases, weakening the curing effect of the film coating.

[0082] Other beneficial effects of the solidified material of the present invention are as follows:

[0083] (1) The curing time is fast, the cost is low, and the construction is convenient. The curing material and the silt can be mixed and stirred evenly on site;

[0084] (2) Good curing / stabilization performance, strong water resistance, etc., and the strength increases slowly over time, ensuring long-term use;

[0085] (3) Avoid using gravel, brick slag, etc. to backfill, which may cause mud and uneven subsidence after rain. No secondary treatment is required.

[0086] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which the present invention pertains. The terms used herein in the specification of the present invention are for the purpose of describing specific embodiments only and are not intended to limit the present invention. The various technical features of the embodiments described above may be combined arbitrarily. To simplify the description, not all possible combinations of the various technical features in the embodiments described above are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

Claims

1. A high-water content soft soil solidification material, characterized in that: The solidifying material comprises, by mass percentage, 90%-10% of cement gelling material, 10%-90% of alkali-activated gelling material and 0-1% of acrylate gelling material; the content of the acrylate gelling material is greater than 0; The cementitious material comprises, by mass percentage: Portland cement 10%-80% Stone powder 5%-60% Gypsum 5%-30%; The alkali-activated gelling material comprises, by mass percentage: Gelling component 30%-95% Alkali activator 5%-40%; The acrylate gel material comprises, by mass percentage: Acrylate 0-50% Polyaluminium chloride 100%-50%; The content of the acrylate is greater than 0; The moisture content of the high-moisture soft soil is above 70%; the moisture content of the high-moisture soft soil is reduced by more than 20% after being cured by the curing material for 1 day; The gelling component is at least one of blast furnace slag, fly ash, silica fume, natural pozzolana and steel slag.

2. The high-water content soft soil solidification material according to claim 1, characterized in that: Calculated by mass percentage, the solidifying material includes: 80%-20% cement gelling material, 20%-80% alkali-activated gelling material and 0-1% acrylate gelling material.

3. The high-water content soft soil solidification material according to claim 1, characterized in that: The stone powder is at least one of natural stone powder, construction waste powder and quartz powder.

4. The high-water content soft soil solidification material according to claim 1, characterized in that: The gypsum is at least one of anhydrous gypsum, hemihydrate gypsum and dihydrate gypsum.

5. The high-water content soft soil solidification material according to claim 1, characterized in that: The alkali activator is at least one of quicklime, sodium carbonate, sodium silicate, sodium metaaluminate and sodium sulfate.

6. The high-water content soft soil solidification material according to claim 1, characterized in that: The acrylate is at least one of magnesium acrylate, sodium acrylate and calcium acrylate.

7. The high-water content soft soil solidification material according to claim 1, characterized in that: The polyaluminium chloride is in the form of solid powder.

8. The method for preparing the high-water content soft soil solidification material according to any one of claims 1 to 7, characterized in that: The cement gelling material, alkali-activated gelling material and acrylate gelling material are uniformly mixed according to corresponding mass ratios and ground to a size of 200 mesh or above, wherein particles with a particle size of less than 10 μm account for more than 30%, thereby obtaining the product.

9. Use of the high-water content soft soil solidification material according to any one of claims 1 to 7, characterized in that: The solidification material is used as a solidifying agent for solidification treatment of soft clay, silty soil, silt and silty clay.

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