A soil stabilizer for a yellow flood region and a method for using the same

Abstract

The application discloses a yellow flood area soil solidifying agent and a use method thereof, and the yellow flood area soil solidifying agent comprises the following raw materials in parts by weight: 40-70 parts of blast furnace slag, 5-20 parts of fly ash, 10-20 parts of lime, 10-20 parts of ordinary Portland cement, 10-20 parts of dust removal ash, 0.5-2 parts of fatty alcohol polyoxyethylene ether and 0.5-2 parts of nano silicon dioxide. The soil solidifying agent is low in price, has a remarkable reinforcing effect on the yellow flood area soil body, can effectively solve the problem of reduction and utilization of a large amount of solid waste, can reduce the cost of solidifying the yellow flood area silt, and has remarkable economic benefits and environmental protection benefits.

Description

Technical Field

[0001] This invention relates to the field of road engineering materials technology, and in particular to a soil stabilizer for the Yellow River floodplain and its application method. Background Technology

[0002] The information disclosed in the background section of this invention is intended only to enhance the understanding of the overall background of the invention and is not necessarily to be construed as an admission or in any way implying that such information constitutes prior art known to those skilled in the art.

[0003] The alluvial silt deposited by the Yellow River in the Yellow River floodplain is widespread across Shandong, Henan, and other vast areas, covering an area of ​​52,100 km². 2 The silt from the Yellow River floodplain is characterized by a uniform particle distribution, with silt particles ranging from 0.075 to 2 mm in diameter typically comprising over 80% of the composition. It has extremely low clay content, resulting in poor bonding properties. The particles are highly rounded, with poor gradation and a lack of fine particle filling, making compaction difficult. When used in areas with high groundwater levels, the well-developed pores of the Yellow River floodplain cause water absorption and softening due to capillary action, increasing the likelihood of soil defects and potential disasters during use. Furthermore, it cannot form a stable structure, exhibiting poor contact performance with other materials and unstable strength. Therefore, the primary challenge in utilizing silt from the Yellow River floodplain is improving its skeletal strength and water stability. Currently available silt solidifiers use high amounts of cement, leading to high construction costs. There is an urgent need to develop a targeted and cost-effective green silt solidifier for the Yellow River floodplain.

[0004] Patent CN 115417652B (authorization announcement date: June 9, 2023) discloses a soil stabilizer for the Yellow River floodplain and its application. It comprises three solid wastes: blast furnace slag, fly ash, and desulfurized gypsum, as well as cement. Diethanolamine monoisopropanolamine is used as a cement activator to compensate for the strength reduction caused by the addition of solid waste. In the soil stabilizer prepared by this patent, the cement content is approximately 30-35% (calculated based on the provided examples). This relatively high cement content results in low unconfined compressive strength, all below 1.7 MPa. Therefore, how to effectively utilize solid waste to prepare a soil stabilizer for silty soil in the Yellow River floodplain while significantly reducing cement usage, and achieving high compressive strength and high water stability in the stabilized soil, remains a challenge. Summary of the Invention

[0005] In view of this, the present invention provides a soil stabilizer for the Yellow River flood plain and its application method. The soil stabilizer can make the stabilized soil have high compressive strength and high water stability while making full use of solid waste and significantly reducing the amount of cement used, thus having good environmental and economic benefits.

[0006] In a first aspect, the present invention provides a soil stabilizer for the Yellow River floodplain, comprising the following raw materials in parts by weight:

[0007] 40-70 parts blast furnace slag, 5-20 parts fly ash, 10-20 parts lime, 10-20 parts ordinary silicate cement, 10-20 parts dust collector ash, 0.5-2 parts fatty alcohol polyoxyethylene ether and 0.5-2 parts nano silica.

[0008] Secondly, the present invention provides a method for using the above-mentioned soil stabilizer in the Yellow River floodplain, comprising the following steps:

[0009] Dust collector ash, fly ash, lime, and silt from the Yellow River floodplain are mixed in a certain proportion to obtain a dry mixture. The dry mixture is then mixed with water and left to stand to obtain a stand mixture.

[0010] Blast furnace slag and ordinary silicate cement are dry-mixed in proportion, and then mixed with the first batch of filling material mixture to obtain the second batch of filling material mixture.

[0011] Fatty alcohol polyoxyethylene ether and nano silica are added to water to prepare a fatty alcohol polyoxyethylene ether-nano silica aqueous solution;

[0012] Add fatty alcohol polyoxyethylene ether-nano silica aqueous solution to curing mixture 2, stir and then cure.

[0013] Compared with the prior art, the present invention has achieved the following beneficial effects:

[0014] (1) This invention provides a green soil solidification agent with solid waste such as dust collector ash, blast furnace slag and fly ash as the main raw materials. It is inexpensive, has a significant strengthening effect on soil, can effectively solve the problem of reducing the amount of solid waste, and can reduce the cost of solidifying silty soil. Compared with cement as a solidification agent, its cost can be reduced by 10-20%, which has significant economic and environmental benefits.

[0015] (2) After solidifying the silt with the soil stabilizer of the present invention, the unconfined compressive strength of the solidified soil samples after 7 days and 28 days of standard curing is high, and the water stability coefficient is high. Moreover, the addition of surfactant fatty alcohol polyoxyethylene ether and auxiliary activator nano silica can improve the soil strength with very small amounts, resulting in a low overall solidification cost. The overall material ratio makes the functions of each material synergistic, maximizing the performance of solidified silt.

[0016] (3) The soil stabilizer of this invention is used to specifically stabilize the silt in the Yellow River floodplain from a mechanistic perspective. Dust collector ash is added to fill the pores of the silt, improving its gradation. Nano-silica adheres to the surface of soil particles, increasing its contact performance with solid waste and cementing materials. The cementing material produced by the combination of multi-component solid waste and ordinary silicate cement, under the action of the surfactant fatty alcohol polyoxyethylene ether, tightly binds the large-scale cementing material between soil particles and solid waste particles, preventing water penetration and evaporation, and improving strength and water stability. This addresses the problems of high sphericity, poor gradation, unstable strength, and weak water stability of the silt. The stabilizer of this invention can transform the silt along the Yellow River Avenue into an economical, reliable, and practically valuable high-quality soil base material. Attached Figure Description

[0017] The accompanying drawings, which form part of this specification, are used to provide a further understanding of the invention. The illustrative embodiments and descriptions of the invention are used to explain the invention and do not constitute an undue limitation thereof. Obviously, those skilled in the art can obtain other drawings based on these drawings without any inventive effort.

[0018] Figure 1 This is a cumulative particle mass percentage distribution diagram of silt from this invention;

[0019] Figure 2 This is a cumulative particle mass distribution diagram of the dust collected by the present invention;

[0020] Figure 3 This is the XRD pattern of the silt solidified by the present invention after 7 days;

[0021] Figure 4 This is the XRD pattern of the silt solidified by the present invention after 28 days. Detailed Implementation

[0022] It should be noted that the following detailed descriptions are exemplary and intended to provide further illustration of the invention. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0023] As noted in the background section, existing soil stabilizers often contain high levels of cement, which inevitably leads to a reduction in strength when solid waste is incorporated. Therefore, this invention provides a soil stabilizer for the Yellow River floodplain and its application method.

[0024] In one embodiment of the present invention, a soil stabilizer for the Yellow River floodplain is provided, comprising the following raw materials in parts by weight:

[0025] 40 - 70 parts of blast furnace slag, 5 - 20 parts of fly ash, 10 - 20 parts of lime, 10 - 20 parts of ordinary Portland cement, 10 - 20 parts of dust removal ash, 0.5 - 2 parts of fatty alcohol polyoxyethylene ether, and 0.5 - 2 parts of nano - silica.

[0026] In some embodiments of the present invention, the particle size of the blast furnace slag does not exceed 0.075 mm, and its calcium oxide content is 30 - 50%. Blast furnace slag is a white powdery industrial waste generated during the process of smelting pig iron. After being mixed with cement clinker and lime, it exhibits certain hydraulic gel properties. The blast furnace slag of the present invention needs to be dried before use.

[0027] In some embodiments of the present invention, the particle size of the fly ash is not greater than 400 mesh, and its main components are silica, alumina, iron oxide, calcium oxide, and sulfur trioxide. Among them, the calcium oxide content is 10 - 15%. Fly ash is the tiny ash particles discharged during the coal - burning process of thermal power generation. It is the most widely used industrial solid waste at present and has potential hydraulicity.

[0028] In some embodiments of the present invention, the particle size of the dust removal ash is 0.31 - 208 μm, and it is a material with good gradation. The dust removal ash is the converter dust removal ash of the steel plant, and its main components are SiO2, KCl, CaMg(CO3)2, Fe2O3, Al2O3, Al6Si2O 13 and (Ca 1-x Mg x )CO3 (0 < x < 0.5). In the prior art, the dust removal ash is often only used as a filler. For example, Patent CN 111635204A uses the waste treatment dust removal ash as a filler for soil stabilizer. However, on the one hand, in the present invention, the good gradation and particle size range of the dust removal ash itself are used to fill the particle size range of silt, forming a good framework of silt + dust removal ash. Due to the relatively large friction angle of the dust removal ash itself, its contact with silt is good, enabling the soil stabilizer and silt to form an overall support effect; on the other hand, the inventors found that SiO2, KCl, CaMg(CO3)2, Al2O3, and Fe2O3 in the dust removal ash of the present invention participate in the formation of tricalcium aluminate ferrite hydrate (C3(AF)H6), thereby greatly improving the strength of the soil stabilizer. The iron oxide content in the dust removal ash of the present invention is 40 - 50%. The presence of a large amount of Fe2O3 can promote the occurrence of the gypsum - free iron phase solid solution reaction inside the material, generating C4(AF)H 13 , and then gradually turning into stable tricalcium aluminate ferrite hydrate (C3(AF)H6), ensuring the further solidification of the soil.

[0029] In some embodiments of the present invention, the lime is lime with a calcium oxide content of more than 90%, and its calcination temperature is generally above 1150℃, with a particle size of 0.1-2mm. In this invention, lime acts as an activator to activate tricalcium silicate and tricalcium aluminate in ordinary silicate cement, fly ash, and blast furnace slag, accelerating the pozzolanic reaction process and ensuring the later-stage strength of the solidified soil.

[0030] In some embodiments of the present invention, the ordinary silicate cement is selected from one of PO 42.5, PO 52.5, and PO 62.5. Cement is a pozzolanic or potentially hydraulic material. During the hydration reaction, the active tricalcium aluminate and tricalcium silicate in the cement form CSH and CASH gels, which are the main cementing materials. At the same time, it drives the less active iron oxide and alumina in the dust to participate in the reaction, and together with nano-silica, it promotes the rate of pozzolanic reaction, allowing the dust to further participate in the pozzolanic reaction. For general soil stabilizers, cement is the most important cementing material, but this only utilizes the material's inherent properties. In the present invention, the main role of ordinary silicate cement is to drive the active components inside the solid waste to participate in the reaction.

[0031] In this invention, fatty alcohol polyoxyethylene ether (EOE) is used as a surfactant. The hydrophobic fatty alcohol segments in its molecular structure effectively encapsulate the highly hydrophobic dust particles, while the hydrophilic EO segments allow for full contact and chemical reaction with the hydrophilic silt particles. The use of surfactant increases the hydrophilicity of the silt surface, enabling the highly hydrophobic dust particles to be well physically encapsulated by the silt and cementing materials, promoting the hydration reaction of the dust particles. Simultaneously, it promotes full contact between solid waste and soil, improving the strength of the modified silt. Furthermore, the surfactant can generate ion exchange, thereby reducing the thickness of the water film on the soil particle surface, increasing particle attraction, enriching more nano-silica on the silt particle surface, expanding the bonding surface between soil particles and cementing products, and thus enhancing water permeability resistance. Therefore, the use of the surfactant fatty alcohol EOE not only improves the strength of the curing agent itself but also enhances its water stability, and only a very small amount is needed to achieve significant results.

[0032] In some embodiments of the present invention, nano-silica is used as an auxiliary activator with a purity exceeding 99%. Nano-silica participates in the pozzolanic reaction, thereby increasing the content of hydrated calcium silicate within the soil, balancing the initial and later strength of the solidified soil, and improving its water stability. Simultaneously, nano-silica exhibits good adsorption properties for silt and solid waste, increasing the friction between these materials, increasing the number of interfacial physical interactions, and enhancing compressive bearing capacity. Furthermore, the amount of nano-silica added is very small, significantly reducing costs while ensuring the performance of the solidified soil.

[0033] In another embodiment of the present invention, a method for using the above-mentioned soil stabilizer in the Yellow River floodplain is provided, comprising the following steps:

[0034] Dust collector ash, fly ash, lime, and silt from the Yellow River floodplain are mixed in a certain proportion to obtain a dry mixture. The dry mixture is then mixed with water and left to stand to obtain a stand mixture.

[0035] Blast furnace slag and ordinary silicate cement are dry-mixed in proportion, and then mixed with the first batch of filling material mixture to obtain the second batch of filling material mixture.

[0036] Fatty alcohol polyoxyethylene ether and nano silica are added to water to prepare a fatty alcohol polyoxyethylene ether-nano silica aqueous solution;

[0037] Add fatty alcohol polyoxyethylene ether-nano silica aqueous solution to curing mixture 2, stir and then cure.

[0038] In some embodiments of the present invention, a pretreatment step of the raw materials is also included, namely, drying the blast furnace slag, dust collector ash and fly ash, and then sieving them separately.

[0039] In some embodiments of the present invention, the weight ratio of soil stabilizer to silt in the Yellow River floodplain is 2~10:90~98, more preferably 5:95.

[0040] In some embodiments of the present invention, the total amount of water accounts for 12-16% of the total weight of the soil stabilizer and the silt from the Yellow River floodplain.

[0041] The technical solution of the present invention will be further described below with reference to specific embodiments. In the following embodiments, the ordinary Portland cement is of type PO 42.5.

[0042] Example 1

[0043] This embodiment provides a soil stabilizer for the Yellow River floodplain, comprising the following raw materials in parts by weight:

[0044] 60 parts blast furnace slag; 5 parts fly ash; 10 parts lime; 20 parts dust collector ash; 20 parts ordinary silicate cement; 0.6 parts fatty alcohol polyoxyethylene ether; 0.6 parts nano silica.

[0045] The method of use is as follows: Dry the dust collector ash, blast furnace slag, and fly ash in an oven at a temperature of 105℃. After drying, blast furnace slag and fly ash are sieved separately. The weight ratio of soil stabilizer to Yellow River floodplain silt is 5:95, and the total amount of water accounts for 14.4% of the total weight of soil stabilizer and Yellow River floodplain silt. First, dry mix lime, dust collector ash, fly ash, and Yellow River floodplain silt in proportion. Mix the dry mixture with some water and let it sit for a period of time according to the "Test Procedure for Inorganic Binder Stabilized Materials for Highway Engineering" (JTGE51-2009). To avoid premature hydration of cement, add blast furnace slag and ordinary silicate cement to the mixture after sitting for 1 hour before molding. Then, add fatty alcohol polyoxyethylene ether and nano silica to the remaining water to make an aqueous solution of fatty alcohol polyoxyethylene ether and nano silica, add it to the above mixture, and stir.

[0046] Example 2

[0047] This embodiment provides a soil stabilizer for the Yellow River floodplain, comprising the following raw materials in parts by weight:

[0048] 50 parts blast furnace slag; 15 parts fly ash; 10 parts lime; 10 parts dust collector ash; 20 parts ordinary silicate cement; 0.6 parts fatty alcohol polyoxyethylene ether; 0.6 parts nano silica.

[0049] The method of use is as follows: Dry the dust collector ash, blast furnace slag, and fly ash in an oven at a temperature of 105℃. After drying, blast furnace slag and fly ash are sieved separately. The weight ratio of soil stabilizer to Yellow River floodplain silt is 5:95, and the total amount of water accounts for 13% of the total weight of soil stabilizer and Yellow River floodplain silt. First, dry mix lime, dust collector ash, fly ash, and Yellow River floodplain silt in proportion. Mix the dry mixture with some water and let it sit for a period of time according to the "Test Procedure for Inorganic Binder Stabilized Materials for Highway Engineering" (JTGE51-2009). To avoid premature hydration of cement, add blast furnace slag and ordinary silicate cement to the mixture after sitting for 1 hour before molding. Then, add fatty alcohol polyoxyethylene ether and nano silica to the remaining water to make an aqueous solution of fatty alcohol polyoxyethylene ether and nano silica, add it to the above mixture, and stir.

[0050] Example 3

[0051] This embodiment provides a soil stabilizer for the Yellow River floodplain, comprising the following raw materials in parts by weight:

[0052] 60 parts blast furnace slag; 5 parts fly ash; 15 parts lime; 10 parts dust collector ash; 15 parts ordinary silicate cement; 0.6 parts fatty alcohol polyoxyethylene ether; 0.6 parts nano silica.

[0053] The usage method is as follows: Dry the dust collector ash, blast furnace slag, and fly ash in an oven at a temperature of 105℃. After drying, blast furnace slag and fly ash are sieved separately. The weight ratio of soil stabilizer to Yellow River floodplain silt is 5:95, and the total amount of water accounts for 15% of the total weight of soil stabilizer and Yellow River floodplain silt. First, dry mix lime, dust collector ash, fly ash, and Yellow River floodplain silt in proportion. Mix the dry mixture with some water and let it sit for a period of time according to the "Test Procedure for Inorganic Binder Stabilized Materials in Highway Engineering" (JTGE51-2009). To avoid premature hydration of cement, add blast furnace slag and ordinary silicate cement to the mixture after sitting for 1 hour before molding. Then, add fatty alcohol polyoxyethylene ether and nano silica to the remaining water to make an aqueous solution of fatty alcohol polyoxyethylene ether and nano silica, add it to the above mixture, and stir.

[0054] Example 4

[0055] This embodiment provides a soil stabilizer for the Yellow River floodplain, comprising the following raw materials in parts by weight:

[0056] 60 parts blast furnace slag; 5 parts fly ash; 15 parts lime; 20 parts dust collector ash; 10 parts ordinary silicate cement; 0.6 parts fatty alcohol polyoxyethylene ether; 0.6 parts nano silica.

[0057] The method of use is as follows: Dry the dust collector ash, blast furnace slag, and fly ash in an oven at a temperature of 105℃. After drying, blast furnace slag and fly ash are sieved separately. The weight ratio of soil stabilizer to Yellow River floodplain silt is 5:95, and the total amount of water accounts for 16% of the total weight of soil stabilizer and Yellow River floodplain silt. First, dry mix lime, dust collector ash, fly ash, and Yellow River floodplain silt in proportion. Mix the dry mixture with some water and let it sit for a period of time according to the "Test Procedure for Inorganic Binder Stabilized Materials in Highway Engineering" (JTGE51-2009). To avoid premature hydration of cement, add blast furnace slag and ordinary silicate cement to the mixture after sitting for 1 hour before molding. Then, add fatty alcohol polyoxyethylene ether and nano silica to the remaining water to make an aqueous solution of fatty alcohol polyoxyethylene ether and nano silica, add it to the above mixture, and stir.

[0058] Comparative Example 1

[0059] The difference compared to Example 1 is that no dust is added.

[0060] The soil stabilizer in this comparative example comprises the following raw materials in parts by weight:

[0061] 60 parts blast furnace slag; 5 parts fly ash; 10 parts lime; 20 parts ordinary silicate cement; 0.6 parts fatty alcohol polyoxyethylene ether; 0.6 parts nano silica.

[0062] Comparative Example 2

[0063] The difference compared to Example 1 is that no nano-silica is added.

[0064] The soil stabilizer in this comparative example comprises the following raw materials in parts by weight:

[0065] 60 parts blast furnace slag; 5 parts fly ash; 10 parts lime; 20 parts dust collector ash; 20 parts ordinary silicate cement; 0.6 parts fatty alcohol polyoxyethylene ether.

[0066] Comparative Example 3

[0067] Compared with Example 1, the difference is that blast furnace slag, fly ash, dust collector ash, fatty alcohol polyoxyethylene ether and nano silica are not added.

[0068] The soil stabilizer in this comparative example comprises the following raw materials in parts by weight:

[0069] 10 parts lime; 20 parts ordinary silicate cement.

[0070] Comparative Example 4

[0071] The difference from Example 1 is that no blast furnace slag and fly ash are added.

[0072] The soil stabilizer in this comparative example comprises the following raw materials in parts by weight:

[0073] 20 parts lime; 20 parts dust removal ash; 20 parts ordinary silicate cement; 0.6 parts fatty alcohol polyoxyethylene ether; 0.6 parts nano silica.

[0074] Comparative Example 5

[0075] The difference compared to Example 1 is that no fatty alcohol polyoxyethylene ether is added.

[0076] The soil stabilizer in this comparative example comprises the following raw materials in parts by weight:

[0077] 60 parts blast furnace slag; 5 parts fly ash; 10 parts lime; 10 parts dust collector ash; 20 parts ordinary silicate cement; 0.6 parts nano silica.

[0078] Comparative Example 6

[0079] The difference compared to Example 1 is that no ordinary silicate cement is added.

[0080] The soil stabilizer in this comparative example comprises the following raw materials in parts by weight:

[0081] 60 parts blast furnace slag; 5 parts fly ash; 10 parts lime; 20 parts dust collector ash; 0.6 parts fatty alcohol polyoxyethylene ether; 0.6 parts nano silica.

[0082] Comparative Example 7

[0083] Compared with Example 1, the difference is that fatty alcohol polyoxyethylene ether is replaced with diethanol monoisopropanolamine.

[0084] The soil stabilizer in this comparative example comprises the following raw materials in parts by weight:

[0085] 60 parts blast furnace slag; 5 parts fly ash; 10 parts lime; 10 parts dust collector ash; 20 parts ordinary silicate cement; 0.6 parts nano silica; 0.6 parts diethanol monoisopropanolamine.

[0086] Test case

[0087] The mechanical properties and water stability of the solidified soils from Examples 1-4 and Comparative Examples 1-7 were determined using the following methods: Cylindrical specimens with a diameter × height of 50 mm × 50 mm were prepared according to the "Test Procedure for Inorganic Binder Stabilized Materials in Highway Engineering" (JTGE51-2009). The unconfined compressive strength of specimens cured in moisture for 6 days and soaked for 1 day, as well as specimens cured for 7 days and 28 days, were tested at 20℃±2℃ and 95% relative humidity. The water stability coefficient was determined according to "Soil Stabilizing Admixtures" CJ / T486. The water stability coefficient is the ratio of the unconfined compressive strength after 6 days of moist curing and 1 day of soaking at 20℃±2℃ and 95% relative humidity to the unconfined compressive strength after 7 days of moist curing at 20℃±2℃ and 95% relative humidity. The test results are listed in Table 1.

[0088] Table 1 Mechanical properties and water stability of solidified soils in the examples and comparative examples

[0089]

[0090] As shown in Table 1, after standard curing, the 7-day unconfined compressive strength of the solidified soil in Examples 1-4 was all above 1.24 MPa, and the 28-day unconfined compressive strength was all above 1.89 MPa. This indicates that the soil stabilizer of the present invention has good early and late strength after solidifying silt. The water stability coefficient was all above 0.89, indicating that the solidified soil obtained using the soil stabilizer of the present invention has good water stability. Furthermore, in the examples, the cement addition percentage was all below 20%, demonstrating significant economic and environmental benefits.

[0091] As can be seen from the comparison between Example 1 and Comparative Example 1, the absence of dust removal ash significantly reduced the early strength and later strength. This is partly because the addition of dust removal ash filled the pores of the silt, forming an early soil skeleton. Figure 1 This is a map showing the cumulative particle size percentage distribution of silt in the Yellow River floodplain. Figure 2 The graph shows the cumulative particle size distribution of dust collector ash. It can be seen that the particle size of silt is mainly concentrated in the 20-200µm range, with a uniform distribution, while the dust collector ash particles are well-graded in the 1-200µm range, filling the internal pores of the silt and forming a soil skeleton structure. On the other hand, X-ray diffraction (XRD) results show... Figure 3 This is the XRD pattern of silty soil after 7 days of solidification. Figure 4 The image shows the XRD pattern of silt cured for 28 days. The peak intensity and peak area of ​​quartz (SiO2), KCl, dolomite [CaMg(CO3)2], and hematite (Fe2O3) in the dust decreased with increasing curing time, while the peak intensity and peak area of ​​tricalcium ferroaluminate hydrate [C3(AF)H6], calcium aluminosilicate hydrate (CASH), ettringite (Aft), and hydrated calcium hydrate (4CaO·Al2O3·12H2O) increased with increasing curing time. This indicates that SiO2, KCl, CaMg(CO3)2, and Fe2O3 participate in the chemical reaction that forms strength, leading to the accumulation of cementing products such as C3(AF)H6, thus increasing the strength in the later stage.

[0092] As can be seen from the comparison between Example 1 and Comparative Example 2, the absence of nano-silica has a significant impact on the later strength and water stability of the solidified soil. This is because the addition of nano-silica not only participates in the volcanic ash reaction, but also has good adsorption properties for silt and solid waste, increasing the friction between silt and solid waste materials. Therefore, nano-silica plays a synergistic role in stimulating the hydration reaction of the entire system.

[0093] The comparison between Example 1 and Comparative Example 3 shows that it is difficult to achieve a good solidification effect by using only ordinary silicate cement and lime as soil stabilizers. It is evident that the introduction of solid waste can not only play a role in disposing of a large amount of solid waste, but also help to improve the mechanical strength and water stability of the solidified soil.

[0094] The comparison between Example 1 and Comparative Example 4 shows that the absence of blast furnace slag and fly ash significantly reduces both mechanical properties and water stability. The solidified soil in Comparative Example 4 exhibits a more significant increase in early strength compared to Comparative Example 3, but the later strength difference is not substantial. This is because the addition of dust fills the pores of the silt, forming an early soil skeleton. It also demonstrates that the surfactants fatty alcohol polyoxyethylene ether and nano-silica require solid waste materials such as fly ash and blast furnace slag to function effectively, indirectly indicating the synergistic effect of fatty alcohol polyoxyethylene ether and nano-silica between the silt in the Yellow River floodplain and solid wastes such as fly ash and blast furnace slag.

[0095] The comparison between Example 1 and Comparative Example 5 shows that the surfactant fatty alcohol polyoxyethylene ether increases the hydrophilicity of the silt surface. This allows the highly hydrophobic dust to be effectively physically encapsulated by the silt and cementing materials. Simultaneously, the dust reacts with the water-containing silt particles to form hydrated calcium aluminoferrite. It can be seen that only a small amount of the surfactant fatty alcohol polyoxyethylene ether is needed to achieve a significant effect.

[0096] The comparison between Example 1 and Comparative Example 6 shows that the absence of cement leads to a significant decrease in the compressive strength and water stability of the solidified soil. The active tricalcium aluminate and tricalcium silicate in the cement form CSH and CASH gels, which are the main cementing materials. Simultaneously, they can drive the less active iron oxide and alumina in the dust to react, and together with nano-silica, they promote the rate of the pozzolanic reaction, allowing the dust to further participate in the pozzolanic reaction.

[0097] As can be seen from the comparison between Example 1 and Comparative Example 7, when fatty alcohol polyoxyethylene ether is replaced with diethanol monoisopropanolamine, the compressive strength and water stability of the solidified soil both decrease, indicating that fatty alcohol polyoxyethylene ether is more effective in promoting the contact between solid waste and soil.

[0098] The main reaction processes in Examples 1-4 of this invention are as follows: After fly ash, slag, and cement are mixed, C3A and C3S in the clinker rapidly undergo hydration reactions, producing hydrated calcium silicate (CSH) gel, ettringite (3CaO·Al2O3·3CaSO4·32H2O), and Ca(OH)2, generating very little hydrated calcium aluminate (CAH) gel, and precipitating a large number of hydroxide ions. The dust collector provides a large amount of Fe2O3, which can promote the gypsum-free iron phase solid solution reaction inside the material, generating C4(AF)H. 13 It then gradually transforms into stable hydrated tricalcium ferroaluminate C3(AF)H6.

[0099]

[0100]

[0101]

[0102]

[0103]

[0104] This invention addresses the various challenges of silt solidification in the Yellow River floodplain by adding dust collector ash to fill the pores of the silt, which is modified by fatty alcohol polyoxyethylene ether. This significantly improves the gradation of the soil material itself. Nano-silica adheres to the surface of soil particles, greatly reducing particle roundness, increasing contact performance with solid waste and cementing materials, and improving overall bonding strength. Solid waste containing cementing components, such as dust collector ash, fly ash, and slag, are activated by lime and nano-silica, and the resulting cementing material, produced together with ordinary silicate cement, provides a guarantee for the strength of the silt. The surfactant fatty alcohol polyoxyethylene ether increases particle attraction, adsorbing more cementing materials. The strong cementing effect prevents water penetration and evaporation, improving water stability. This invention specifically solves the problem of soil solidification in the Yellow River floodplain, providing an economical and reliable solidification material for silt along the Yellow River, and has significant theoretical and practical value.

[0105] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A soil stabilizer for the Yellow River floodplain, characterized in that, The ingredients include the following parts by weight: 40-70 parts blast furnace slag, 5-20 parts fly ash, 10-20 parts lime, 10-20 parts ordinary silicate cement, 10-20 parts dust collector ash, 0.5-2 parts fatty alcohol polyoxyethylene ether and 0.5-2 parts nano silica. The calcium oxide content of the blast furnace slag is 30-50%; The iron oxide content in the dust is 40-50%; the particle size of the dust is 0.31-208μm; the dust is dust from a steel plant converter. The method of using the soil stabilizer in the Yellow River floodplain includes the following steps: Dust collector ash, fly ash, lime, and silt from the Yellow River floodplain are mixed in a certain proportion to obtain a dry mixture. The dry mixture is then mixed with water and left to stand to obtain a stand mixture. Blast furnace slag and ordinary silicate cement are dry-mixed in proportion, and then mixed with the first batch of filling material mixture to obtain the second batch of filling material mixture. Fatty alcohol polyoxyethylene ether and nano silica are added to water to prepare a fatty alcohol polyoxyethylene ether-nano silica aqueous solution; Add fatty alcohol polyoxyethylene ether-nano silica aqueous solution to curing mixture 2, stir and then cure; The weight ratio of the soil stabilizer in the Yellow River floodplain to the silt in the Yellow River floodplain is 2~10:90~98.

2. The soil stabilizer for the Yellow River floodplain as described in claim 1, characterized in that, The particle size of the blast furnace slag does not exceed 0.075 mm.

3. The soil stabilizer for the Yellow River floodplain as described in claim 1, characterized in that, The particle size of the fly ash is no greater than 400 mesh.

4. The soil stabilizer for the Yellow River floodplain as described in claim 1, characterized in that, The lime contains more than 90% calcium oxides and has a particle size of 0.1-2 mm.

5. The method of using the soil stabilizer for the Yellow River floodplain as described in any one of claims 1-4, characterized in that, Includes the following steps: Dust collector ash, fly ash, lime, and silt from the Yellow River floodplain are mixed in a certain proportion to obtain a dry mixture. The dry mixture is then mixed with water and left to stand to obtain a stand mixture. Blast furnace slag and ordinary silicate cement are dry-mixed in proportion, and then mixed with the first batch of filling material mixture to obtain the second batch of filling material mixture. Fatty alcohol polyoxyethylene ether and nano silica are added to water to prepare a fatty alcohol polyoxyethylene ether-nano silica aqueous solution; Add fatty alcohol polyoxyethylene ether-nano silica aqueous solution to curing mixture 2, stir and then cure.

6. The method of use as described in claim 5, characterized in that, The weight ratio of the soil stabilizer in the Yellow River floodplain to the silt in the Yellow River floodplain is 2~10:90~98.

7. The method of use as described in claim 6, characterized in that, The total amount of water used accounts for 12-16% of the total weight of soil stabilizer and silt in the Yellow River floodplain.

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