Salinized soil curing agent and in-situ curing method of salinized soil

Abstract

The invention provides a salinized soil curing agent and an in-situ curing method of salinized soil, and belongs to the field of industrial solid waste resource utilization and road engineering. The salinized soil curing agent comprises solid waste dry powder and a meta-aluminate enhancer, the solid waste dry powder comprises 20-25 parts by mass of fly ash, 30-35 parts by mass of superfine slag powder, 25-35 parts by mass of superfine steel slag powder and 10-25 parts by mass of desulfurized gypsum; the mass of the meta-aluminate enhancer is 1%-5% of the mass of the solid waste dry powder; the salinized soil is sulfate salinized soil or sulfite salinized soil. According to the salinized soil curing agent, sulfate or sulfite in salinized soil can be directly used as an exciting agent, salt stabilization and soil body structure strengthening are synchronously achieved, meanwhile, industrial solid waste can be effectively utilized, use of traditional high-energy-consumption cementing materials is avoided, construction energy consumption is reduced, and the environmental protection pressure of road construction is relieved.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to the fields of industrial solid waste resource utilization and road engineering, in particular, to a saline soil salinity-activated saline soil solidifying agent and an in-situ solidification method of saline soil. BACKGROUND

[0002] Due to the presence of high-concentration sulfate and chloride salts in saline soil, engineering diseases such as salt heaving damage, corrosion failure, and salt freezing synergistic damage are easily induced, resulting in increased costs of roadbed repair and road maintenance. It is a difficult problem in the industry to solidify the saline soil roadbed and ensure the long-term service performance of the saline soil. Traditional cementitious materials such as cement are easily eroded by sulfate and chloride salts, and pose a greater threat to the environment. Using industrial solid waste as a cementitious material for solidifying saline soil can alleviate the corrosion problem of saline soil and achieve resource utilization of solid waste, thereby reducing the pressure on the environment, and thus has attracted widespread attention and application.

[0003] However, there are still limitations in using industrial solid waste-based cementitious materials to solidify saline soil at the present stage. Patent CN114940608A discloses a method for improving sulfate saline soil and a solidifying agent. Although the invention effectively manages sulfate saline soil, the design and preparation of the solidifying agent still rely on the addition of cement, and the activity of the salt in the soil is not utilized. In addition, since the solidifying agent uses cement and magnesium oxide, its economy and environmental friendliness still need to be further investigated.

[0004] Patent CN118930159A discloses a roadbed filler for treating tunnel excavation waste saline loess based on a solidifying agent, which includes 23-27 parts of magnesium slag, 3-5 parts of fly ash, 1-3 parts of an activator, 6-8 parts of a reinforcing agent, and 3-5 parts of an adsorbent. The invention makes full use of industrial solid waste materials and effectively adsorbs sulfate in the soil. However, the preparation of the adsorbent requires high-temperature baking, and the preparation process is relatively complex, consuming time and energy. The above-mentioned patent has a common technical defect, which is that the salt is regarded as a harmful substance rather than a usable chemical reaction activator, the activation of solid waste relies on a high-alkaline environment, and it poses a threat to the soil environment. Therefore, there is an urgent need to develop environmentally friendly industrial solid waste-based solidifying agents and green and efficient saline soil solidification methods.

[0005] It should be noted that the information disclosed in the above background section is only used to strengthen the understanding of the background of the present disclosure, and therefore can include information that does not constitute prior art known to those of ordinary skill in the art. SUMMARY

[0006] The present disclosure aims to overcome the deficiencies of the prior art, and provides a saline soil salinity-activated saline soil stabilizer and a saline soil in-situ stabilization method. The saline soil stabilizer can directly use sulfate or sulfite in the saline soil as an activator, simultaneously achieving salt stabilization and soil structure strengthening, and can effectively utilize industrial solid waste, avoid the use of traditional high-energy consumption cementing materials, reduce construction energy consumption, and relieve environmental pressure in road construction.

[0007] According to one aspect of the present disclosure, a saline soil salinity-activated saline soil stabilizer is provided, comprising solid waste dry powder and metasilicate reinforcing agent; the solid waste dry powder comprises fly ash 20-25 parts by mass, slag powder 30-35 parts by mass, steel slag powder 25-35 parts by mass, and desulfurization gypsum 10-25 parts by mass; The mass of the metasilicate reinforcing agent is 1%-5% of the mass of the solid waste dry powder; The saline soil is sulfate saline soil or sulfite saline soil.

[0008] According to one embodiment of the present disclosure, the specific surface area of the fly ash is not less than 350 The specific surface area of the slag powder is not less than 420 The specific surface area of the steel slag powder is not less than 450 The specific surface area of the desulfurization gypsum is between 300 and 350 .

[0009] According to one embodiment of the present disclosure, the fly ash is produced by burning lignite or sub-bituminous coal.

[0010] According to one embodiment of the present disclosure, the metasilicate reinforcing agent is calcium-based metasilicate.

[0011] According to one embodiment of the present disclosure, the solid waste dry powder comprises fly ash 25 parts by mass, slag powder 30 parts by mass, steel slag powder 25 parts by mass, and desulfurization gypsum 20 parts by mass; the mass of the metasilicate reinforcing agent is 3% of the mass of the solid waste dry powder.

[0012] According to one embodiment of the present disclosure, the solid waste dry powder comprises fly ash 20 parts by mass, slag powder 30 parts by mass, steel slag powder 35 parts by mass, and desulfurization gypsum 15 parts by mass; the mass of the metasilicate reinforcing agent is 2% of the mass of the solid waste dry powder.

[0013] According to one embodiment of the present disclosure, the mass content of soluble salt in the sulfate saline soil is not less than 2%.

[0014] According to one embodiment of the present disclosure, the saline soil stabilizer is composed of solid waste dry powder and metasilicate reinforcing agent; The solid waste dry powder is composed of fly ash 20-25 parts by mass, slag powder 30-35 parts by mass, steel slag powder 25-35 parts by mass, and desulfurization gypsum 10-25 parts by mass.

[0015] According to another aspect of the present disclosure, a method for in-situ solidification of saline soil is provided, comprising: Step 1, mixing the solid waste dry powder of the above-mentioned saline soil solidification agent with a metasilicate reinforcing agent, then adding water and mixing uniformly to obtain an activated saline soil solidification agent; Step 2, incorporating the activated saline soil solidification agent into the saline soil by mechanical mixing; Step 3, compacting the saline soil into which the saline soil solidification agent is incorporated to form a subgrade and curing; wherein during the compaction and curing of the saline soil, the soluble salt in the saline soil acts as an activator to activate the saline soil solidification agent, and ettringite is generated in-situ, the cementing phase, and the cementing phase, while consuming the soluble salt in the saline soil, forming a cemented soil structure, and completing the in-situ solidification of the saline soil.

[0016] According to an embodiment of the present disclosure, the mass of the saline soil solidification agent is 6%-18% of the mass of the saline soil to be solidified.

[0017] The saline soil solidification agent activated by the salt in the saline soil provided by the present application can utilize the sulfate or sulfite in the saline soil to react with the silicon-aluminum phase component in the solid waste to generate controllable hydration products, activate the solid waste-based solidification agent, and at the same time avoid diseases such as erosion and expansion of the salt, thereby improving the durability of the saline soil subgrade. Compared with other technologies, the present application makes full use of the salt resources in the saline soil as an activation source, avoiding the use of strong alkaline activators to damage the soil environment. At the same time, the saline soil solidification agent of the present application effectively consumes the salt in the saline soil while ensuring the reactivity of the solidification agent, thereby ensuring the strength of the subgrade. In addition, since industrial solid waste is used as the solidification material, the use of traditional high-energy consumption cementitious materials is avoided, reducing resource and energy consumption, alleviating environmental pressure, widening the high-value utilization way of industrial solid waste, and being conducive to the green development of road engineering. In particular, the low-cost steel slag powder is used in the solid waste dry powder of the present application to replace part of the slag powder, which expands the utilization way of steel slag solid waste and reduces the cost of the saline soil solidification agent.

[0018] For the soluble salt content of 3.1% of the sulfate saline soil, after curing with the saline soil curing agent with a mass fraction of not more than 12%, the 7-day compressive strength of the cured saline soil is not less than 1.5 MPa, the 28-day compressive strength is not less than 5 MPa, and the strength loss after 10 cycles of salt freezing (-20℃~45℃ to reflect the extreme environment) is less than 15%. The saline soil curing agent of the saline soil salt excitation of the application has obvious curing effect on the high-soluble salt saline soil compared with common curing agents such as cement.

[0019] It should be understood that the above general description and the following detailed description are only exemplary and explanatory, and cannot limit the present disclosure. BRIEF DESCRIPTION OF DRAWINGS

[0020] The drawings herein are incorporated into the specification and form a part of the specification, show embodiments consistent with the present disclosure, and together with the specification serve to explain the principles of the present disclosure. Obviously, the drawings in the following description are only some embodiments of the present disclosure, and other drawings can also be obtained from these drawings without creative labor for those skilled in the art.

[0021] Figure 1 The unconfined compressive strength diagram of the cured soil sample of each example and comparative example.

[0022] Figure 2 The strength loss rate diagram of the cured soil sample of each example and comparative example caused by salt freeze-thaw test. DETAILED DESCRIPTION

[0023] Example implementations will now be described more fully with reference to the accompanying drawings. Example implementations, however, can be implemented in many different forms and should not be construed as limited to the implementations set forth herein; rather, these implementations are provided so that this disclosure will be thorough and complete, and will fully convey the concept of example implementations to those skilled in the art. Like reference numerals refer to like elements throughout the drawings, and thus a detailed description of them will not be repeated. In addition, the drawings are merely schematic and are not necessarily drawn to scale.

[0024] Although relative terms such as "upper" and "lower" are used in this specification to describe the relative relationship of one component of the icon to another component, these terms are used in this specification only for convenience, for example, according to the direction of the examples described in the drawings. It can be understood that if the device of the icon is turned upside down, the component described as "upper" will become the component described as "lower". When a structure is "on" another structure, it can mean that the structure is integrally formed on the other structure, or that the structure is "directly" disposed on the other structure, or that the structure is "indirectly" disposed on the other structure through another structure.

[0025] The application provides a saline soil salinity-activated saline soil curing agent and a in-situ curing method for curing saline soil by using the saline soil curing agent.

[0026] The saline soil curing agent comprises solid waste dry powder and metakaolin reinforcing agent; the solid waste dry powder comprises fly ash 20-25 parts by mass, slag powder 30-35 parts by mass, steel slag powder 25-35 parts by mass, and desulfurization gypsum 10-25 parts by mass; the mass of the metakaolin reinforcing agent is 1%-5% of the mass of the solid waste dry powder; and the saline soil is sulfate saline soil or sulfite saline soil.

[0027] The in-situ curing method for curing saline soil by using the saline soil curing agent comprises the following steps: Step 1, mixing the solid waste dry powder and the metakaolin reinforcing agent, then adding water and mixing uniformly to obtain an activated saline soil curing agent; Step 2, mixing the activated saline soil curing agent into the saline soil by mechanical mixing; Step 3, compacting the saline soil into which the saline soil curing agent is mixed to form a subgrade and curing; during the compaction and curing of the saline soil, the soluble salt in the saline soil acts as an activator to activate the saline soil curing agent, and at the same time, ettringite, gel phase (C-S-H gel phase) and gel phase (C-A-S-H gel phase) are generated in-situ, the soluble salt in the saline soil is consumed, a cemented soil structure is formed, and the in-situ curing of the saline soil is completed.

[0028] In the application, the soluble salt in the saline soil can activate the saline soil curing agent, so that the solid waste powder is rapidly hydrated to form C-S-H gel phase, thereby rapidly curing the saline soil. During the curing process, sulfate ions can participate in the formation of ettringite and fill in the voids, sodium ions can be adsorbed and ion-exchanged by the C-S-H gel phase, and possible sulfite ions can be oxidized by the iron phase in the steel slag to be converted into sulfate ions and fixed. Therefore, in the early stage of the in-situ curing of the saline soil, most of the soluble salt in the saline soil is consumed or cured, and the rapidly formed C-S-H gel phase can provide a larger initial strength. During the subsequent curing process, the gel phase is gradually formed and further exchanges with sodium ions, the sodium ions are more strongly fixed, and the long-term development of the strength of the cured saline soil is promoted. At the same time, gypsum, steel slag and the like promote the continuous generation of ettringite during the curing process to improve the curing strength of the sulfur ions, and the continuously generated ettringite microcrystals fill in the voids of the soil body and are wrapped and fixed by the gradually developed gel phase, thereby realizing the continuous cementation of the soil structure.

[0029] The salted soil salt content excited salted soil curing agent of the present application does not need to add calcium oxide, calcium hydroxide, magnesium oxide or other high alkaline components as an exciter, which can reduce the cost of the salted soil curing agent on the one hand, and can avoid the environmental pollution risk caused by the additional addition of strong alkali on the other hand.

[0030] In the present application, if the molar concentration of sulfate ions in the soluble salt of the salted soil is not less than twice the molar concentration of chloride ions, the salted soil is taken as a sulfate salted soil. If the molar concentration of sulfate ions in the soluble salt of the salted soil is 1-2 times the molar concentration of chloride ions, the salted soil is taken as a sulfite salted soil.

[0031] In an embodiment of the present disclosure, the specific surface area of the fly ash is not less than 350 , the specific surface area of the slag powder is not less than 420 , the specific surface area of the steel slag powder is not less than 450 , and the specific surface area of the desulfurization gypsum is between 300 ~ 350 . In this way, the glass body of the solid waste powder is effectively broken in the excitation stage to quickly improve the early strength of the cured salted soil; on the other hand, it is beneficial to the release of calcium, aluminum and other components of the solid waste to promote the long-term development of the gel phase and the continuous formation of ettringite microcrystals, which is beneficial to the long-term development of the strength of the cured salted soil and the more complete consumption of soluble salt.

[0032] In an embodiment of the present disclosure, the fly ash is the fly ash produced by the combustion of lignite or sub-bituminous coal. In this way, the development speed of C-S-H gel phase in the cured salted soil can be improved and the excitation speed of the salted soil curing agent can be reduced.

[0033] In an embodiment of the present disclosure, the aluminate strengthening agent is a calcium-based aluminate. In this way, the continuous development of C-A-S-H gel phase can be further promoted, which is beneficial to the continuous development of the strength of the cured salted soil and the long-term adsorption / exchange capacity of the soluble salt. In an example, the calcium-based aluminate is monocalcium aluminate powder, dicalcium aluminate powder or heptacalcium dodecylaluminate powder.

[0034] In an embodiment of the present disclosure, the solid waste dry powder includes 25 parts by mass of fly ash, 30 parts by mass of slag powder, 25 parts by mass of steel slag powder and 20 parts by mass of desulfurization gypsum; the mass of the aluminate strengthening agent is 3% of the mass of the solid waste dry powder.

[0035] In an embodiment of the present disclosure, the solid waste dry powder includes 20 parts by mass of fly ash, 30 parts by mass of slag powder, 35 parts by mass of steel slag powder and 15 parts by mass of desulfurization gypsum; the mass of the aluminate strengthening agent is 2% of the mass of the solid waste dry powder.

[0036] In an embodiment of the present disclosure, the mass content of soluble salt in the sulfate saline soil is not less than 2%, for example, the mass content of soluble salt is between 2% and 5%, particularly between 3.0% and 5.0%. For example, the mass content of soluble salt in the sulfate saline soil is 3%, 3.1%, 3.2%, 3.3%, 3.4%, 3.5%, 3.6%, 3.7%, 3.8%, 3.9%, 4%, 4.1%, 4.2%, 4.3%, 4.4%, 4.5%, 4.6%, 4.7%, 4.8%, 4.9% or 5%.

[0037] In an embodiment of the present disclosure, the saline soil curing agent is composed of solid waste dry powder and metasilicate reinforcing agent; the solid waste dry powder is composed of fly ash 20-25 parts by mass, slag powder 30-35 parts by mass, steel slag powder 25-35 parts by mass, and desulfurization gypsum 10-25 parts by mass.

[0038] In other words, the saline soil curing agent provided by the present application is composed of all industrial solid wastes except the metasilicate reinforcing agent, and the curing of the saline soil is achieved by the combination of the four kinds of industrial solid waste powders. The saline soil curing agent of the present application does not contain additional strong alkali and does not contain organic materials (such as cellulose-based adhesives, surfactants, etc.).

[0039] In an embodiment of the present disclosure, the mass of the saline soil curing agent is 6%-18% of the mass of the saline soil to be cured, particularly 8%-12%. For example, the mass of the saline soil curing agent is 8%, 8.5%, 9%, 9.5%, 10%, 10.5%, 11%, 11.5% or 12% of the mass of the saline soil to be cured.

[0040] In an embodiment of the present disclosure, after the activated saline soil curing agent is mixed into the saline soil by mechanical mixing, the water content of the saline soil mixed with the curing agent is between 10% and 18%.

[0041] Optionally, before the saline soil is cured using the saline soil curing agent, a test can be performed to determine the amount of water to be added in actual application. For example, the optimal water content of the saline soil mixed with the curing agent and the natural water content of the saline soil to be cured can be determined by experiment, and then the amount of water to be added in step 1 can be determined.

[0042] In an example, the optimal water content of the saline soil mixed with the curing agent can be determined by a compaction test.

[0043] In an example, the compaction degree of the field construction can be determined by a compaction test.

[0044] The in-situ solidification effect of the saline soil solidification agent for saline soil activated by salt content of saline soil provided by the embodiments of the present disclosure on the saline soil is introduced as follows in multiple embodiments and comparative examples.

[0045] Example 1 The in-situ solidification method of the saline soil solidification agent for saline soil activated by salt content of saline soil includes: Step 1, preparation of the saline soil solidification agent. Fly ash (25 parts by mass), ground slag (30 parts by mass), ground steel slag (25 parts by mass) and desulfurization gypsum (20 parts by mass) are uniformly mixed as dry solid waste powder; calcium-based metakaolin is used as a reinforcing agent, and the addition amount is 1% of the mass of the dry solid waste powder.

[0046] Step 2, preparation of the test soil material. The test soil material is a mixture of the saline soil solidification agent and the saline soil to be solidified, and the mass of the saline soil solidification agent is 8% of the mass of the saline soil.

[0047] Step 3, compaction test of the test soil material, and the optimal water content is determined to be 14%.

[0048] Step 4, mixing of the saline soil solidification agent and water according to the optimal water content, and then mixing with the saline soil to be solidified to obtain the solidified soil material. The mass of the saline soil solidification agent is 8% of the mass of the saline soil. The saline soil is sulfate saline soil, and the mass content of soluble salt is 3.1%.

[0049] Step 5, compaction molding of the solidified soil material by vibration compaction, and the solidified soil is obtained after standard curing.

[0050] Example 2 The in-situ solidification method of the saline soil solidification agent for saline soil activated by salt content of saline soil includes: Step 1, preparation of the saline soil solidification agent. Fly ash (25 parts by mass), ground slag (30 parts by mass), ground steel slag (25 parts by mass) and desulfurization gypsum (20 parts by mass) are uniformly mixed as dry solid waste powder; calcium-based metakaolin is used as a reinforcing agent, and the addition amount is 1% of the mass of the dry solid waste powder.

[0051] Step 2, preparation of the test soil material. The test soil material is a mixture of the saline soil solidification agent and the saline soil to be solidified, and the mass of the saline soil solidification agent is 8% of the mass of the saline soil.

[0052] Step 3, compaction test of the test soil material, and the optimal water content is determined to be 14%.

[0053] Step 4, mixing of the saline soil solidification agent and water according to the optimal water content, and then mixing with the saline soil to be solidified to obtain the solidified soil material. The mass of the saline soil solidification agent is 8% of the mass of the saline soil. The saline soil is sulfate saline soil, and the mass content of soluble salt is 3.1%.

[0054] Step 5, the solidified soil material is compacted by vibration compaction, and the solidified soil is obtained after standard curing.

[0055] Example 3 The in-situ solidification method of saline soil by saline soil salt-activated saline soil solidifier includes: Step 1, preparing the saline soil solidifier. Fly ash (25 parts by mass), slag powder (30 parts by mass), steel slag powder (25 parts by mass), and desulfurization gypsum (20 parts by mass) are uniformly mixed as solid waste dry powder; the calcium-based metakaolin is used as a reinforcing agent, and the addition amount is 3% of the mass of the solid waste dry powder.

[0056] Step 2, preparing the test soil material. The test soil material is a mixture of the saline soil solidifier and the saline soil to be solidified, and the mass of the saline soil solidifier is 12% of the mass of the saline soil.

[0057] Step 3, conducting the compaction test on the test soil material to determine that the optimal water content is 17.5%.

[0058] Step 4, mixing the saline soil solidifier with water according to the optimal water content, and then mixing it with the saline soil to be solidified to obtain the solidified soil material. The mass of the saline soil solidifier is 12% of the mass of the saline soil. The saline soil is sulfate saline soil, and the mass content of soluble salt is 3.1%.

[0059] Step 5, compacting the solidified soil material by vibration compaction, and obtaining the solidified soil after standard curing.

[0060] Example 4 The in-situ solidification method of saline soil by saline soil salt-activated saline soil solidifier includes: Step 1, preparing the saline soil solidifier. Fly ash (20 parts by mass), slag powder (30 parts by mass), steel slag powder (35 parts by mass), and desulfurization gypsum (15 parts by mass) are uniformly mixed as solid waste dry powder; the calcium-based metakaolin is used as a reinforcing agent, and the addition amount is 2% of the mass of the solid waste dry powder.

[0061] Step 2, preparing the test soil material. The test soil material is a mixture of the saline soil solidifier and the saline soil to be solidified, and the mass of the saline soil solidifier is 12% of the mass of the saline soil.

[0062] Step 3, conducting the compaction test on the test soil material to determine that the optimal water content is 16%.

[0063] Step 4, mixing the saline soil solidifier with water according to the optimal water content, and then mixing it with the saline soil to be solidified to obtain the solidified soil material. The mass of the saline soil solidifier is 12% of the mass of the saline soil. The saline soil is sulfate saline soil, and the mass content of soluble salt is 3.1%.

[0064] Step 5, the solidified soil material is compacted by vibration compaction, and the solidified soil is obtained after standard curing.

[0065] Comparative Example 1 The solidification method of the saline soil comprises: Step 1, preparing the test soil material. The test soil material is a mixture of ordinary Portland cement and the saline soil to be solidified, and the mass of the ordinary Portland cement is 8% of the mass of the saline soil.

[0066] Step 2, performing the compaction test on the test soil material to determine that the optimal water content is 13.8%.

[0067] Step 3, mixing the ordinary Portland cement, the saline soil and water according to the optimal water content to obtain the solidified soil material. The mass of the ordinary Portland cement is 8% of the mass of the saline soil. The saline soil is a sulfate saline soil, and the mass content of the soluble salt is 3.1%.

[0068] Step 4, compacting the solidified soil material by vibration compaction, and the solidified soil is obtained after standard curing.

[0069] Comparative Example 2 The solidification method of the saline soil comprises: Step 1, preparing the test soil material. The test soil material is a mixture of sulfate-resistant cement and the saline soil to be solidified, and the mass of the sulfate-resistant cement is 8% of the mass of the saline soil.

[0070] Step 2, performing the compaction test on the test soil material to determine that the optimal water content is 14.5%.

[0071] Step 3, mixing the sulfate-resistant cement, the saline soil and water according to the optimal water content to obtain the solidified soil material. The mass of the sulfate-resistant cement is 8% of the mass of the saline soil. The saline soil is a sulfate saline soil, and the mass content of the soluble salt is 3.1%.

[0072] Step 4, compacting the solidified soil material by vibration compaction, and the solidified soil is obtained after standard curing.

[0073] The strength and durability of the solidified soil samples obtained in the above Examples 1 to 4 and Comparative Examples 1 to 2 are effectively detected and analyzed by using the compressive strength test and the salt freeze-thaw cycle test.

[0074] A 30kN pressure testing machine is selected to measure the unconfined compressive strength of the solidified soil samples after curing for 7d and 28d, and the measurement results are as follows: Figure 1As shown. By analyzing the figure, it can be seen that under the same curing agent dosage, the 7d unconfined compressive strength of the cured soil sample cured by the saline soil curing agent stimulated by the saline soil provided by the present invention is basically the same as that of the cured soil sample cured by sulfate-resistant cement and ordinary Portland cement; under the same curing agent dosage, the 28d unconfined compressive strength of the cured soil sample cured by the saline soil curing agent stimulated by the saline soil provided by the present invention is significantly higher than that of the cured soil sample cured by sulfate-resistant cement and ordinary Portland cement. At the same time, according to Figure 1 It can be seen that increasing the dosage of the saline soil salt-activated saline soil solidifier can further improve the initial strength and long-term strength of the solidified soil sample. This shows that the saline soil salt-activated saline soil solidifier provided by the present invention can achieve rapid solidification and sustained strength development of saline soil without the need for additional strong alkaline activators and organic materials.

[0075] The salt freeze-thaw test temperature was set at -10℃~45℃ and the number of cycles was 10. After the cycles, the durability of the different solidified soil samples was compared by the strength loss rate. Figure 2 .according to Figure 2 It can be seen that the strength loss rate of the solidified soil samples formed by the saline soil solidifying agent activated by the salt of the saline soil provided by the present invention is less than that of the solidified soil samples solidified by sulfate-resistant cement and ordinary Portland cement, and the strength loss of the solidified soil samples solidified by ordinary Portland cement is the largest. This shows that the saline soil solidifying agent activated by the salt of the saline soil provided by the present invention significantly improves the salt erosion resistance and durability of the solidified soil. This is mainly because the solid waste components of the saline soil solidifying agent activated by the salt of the saline soil effectively fix and consume the soluble salt ions in the saline soil and convert them into hydration products, realizing the consumption of salt and the development of the strength of the solidified soil, thereby improving the durability of the solidified soil.

[0076] Those skilled in the art will readily appreciate other embodiments of the present disclosure after considering the specification and practicing the invention disclosed herein. This application is intended to cover any variations, uses, or adaptations of the present disclosure that follow the general principles of the present disclosure and include common knowledge or customary techniques in the art not disclosed herein. The description and examples are to be considered as exemplary only, with the true scope and spirit of the present disclosure being indicated by the appended claims.

Claims

1. A saline soil solidifier activated by saline soil salt, characterized in that: It includes solid waste dry powder and a metaaluminate strengthener; the solid waste dry powder includes 20-25 parts by mass of fly ash, 30-35 parts by mass of slag fine powder, 25-35 parts by mass of steel slag fine powder, and 10-25 parts by mass of desulfurization gypsum; The mass of the metaaluminate enhancer is 1% to 5% of the mass of the solid waste dry powder; The saline soil is sulfate saline soil or sulfite saline soil.

2. The saline soil solidifying agent according to claim 1, characterized in that The specific surface area of ​​the fly ash is not less than 350 The specific surface area of ​​the slag powder is not less than 420 The specific surface area of ​​the steel slag powder is not less than 450 The specific surface area of ​​the desulfurized gypsum is 300 ~ 350 between.

3. The saline soil solidifying agent according to claim 1, characterized in that: The fly ash is fly ash produced by burning lignite or sub-bituminous coal.

4. The saline soil solidifying agent according to claim 1, characterized in that The aluminate strengthener is calcium-based aluminate.

5. The saline soil solidifying agent according to any one of claims 1 to 4, characterized in that: The solid waste dry powder includes 25 parts by mass of fly ash, 30 parts by mass of slag powder, 25 parts by mass of steel slag powder, and 20 parts by mass of desulfurization gypsum; the mass of the aluminate strengthener is 3% of the mass of the solid waste dry powder.

6. The saline soil solidifying agent according to any one of claims 1 to 4, characterized in that: The solid waste dry powder includes 20 parts by mass of fly ash, 30 parts by mass of slag powder, 35 parts by mass of steel slag powder, and 15 parts by mass of desulfurization gypsum; the mass of the aluminate strengthener is 2% of the mass of the solid waste dry powder.

7. The saline soil solidifying agent according to any one of claims 1 to 4, characterized in that: The mass content of soluble salt in the sulfate saline soil is not less than 2%.

8. The saline soil solidifying agent according to any one of claims 1 to 4, characterized in that: The saline soil solidifying agent is composed of solid waste dry powder and aluminate strengthening agent; The solid waste dry powder consists of 20-25 parts by mass of fly ash, 30-35 parts by mass of slag fine powder, 25-35 parts by mass of steel slag fine powder, and 10-25 parts by mass of desulfurization gypsum.

9. An in-situ solidification method for saline soil, characterized in that: include: Step 1: mixing the solid waste dry powder of the saline soil solidifying agent according to any one of claims 1 to 8 with a metaaluminate strengthener, adding water and mixing evenly to obtain an activated saline soil solidifying agent; Step 2, adding the activated saline soil solidifying agent into the saline soil by mechanical mixing; Step 3, compacting the saline soil mixed with the saline soil curing agent to form a roadbed and curing; wherein, during the compaction and curing process of the saline soil, the soluble salt in the saline soil acts as an activator to stimulate the saline soil curing agent, generating ettringite, Gel phase and While the cementing phase is in progress, the soluble salts in the saline soil are consumed to form a cemented soil structure, thus completing the in-situ solidification of the saline soil.

10. The in-situ solidification method for saline soil according to claim 9, characterized in that: The mass of the saline soil curing agent is 6% to 18% of the mass of the saline soil to be cured.

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