Cementing material for anti-freezing soft soil and preparation method thereof

Abstract

The invention discloses a cementing material for anti-freezing soft soil. The cementing material comprises the following components in parts by weight: 40-60 parts of modified steel slag powder, 10-25 parts of sodium hydroxide, 8-15 parts of sodium carbonate, 8-15 parts of modified waste gypsum and 3-8 parts of cement. The prepared cementing material for the anti-freezing soft soil can reduce the use amount of cement, and enables the solidified soft soil to have a good anti-freezing and anti-thawing cycle effect.

Description

Technical Field

[0001] The present invention relates to the technical field of cementing materials, and in particular to a cementing material for antifreeze soft soil and a preparation method thereof. Background Art

[0002] The natural moisture content of soft soil is usually over 50%, and the porosity is high. After solidification, as the water evaporates, there are many internal pores with large pore diameters, which makes it very easy to crack under the action of freeze-thaw cycles. The temperature difference between day and night is large in the northern coastal areas. The solidified soft soil formed by the construction of soft soil solidification projects, such as cement mixing piles and in-situ solidification, is very easy to crack under the action of freeze-thaw cycles due to its high initial moisture content and relatively large pores. At present, cement is still used as the main soft soil solidification material in projects. Cement production belongs to a high-pollution and high-carbon emission industry, which is not conducive to environmental protection.

[0003] Therefore, it is necessary to propose a green soil binder with excellent anti-freeze-thaw cycle effect to replace cement for soft soil solidification related projects in areas with large temperature differences between day and night. It can be widely used in mixing piles / jet grouting piles, in-situ solidification and other fields. Summary of the invention

[0004] The technical problem to be solved by the present invention is to provide a cementing material for antifreeze soft soil, which can reduce the amount of cement and make the solidified soft soil have better anti-freeze-thaw cycle effect.

[0005] The technical problem to be solved by the present invention is also to provide a method for preparing a cementing material for antifreeze soft soil, wherein the preparation method is simple and does not require complicated processing conditions.

[0006] In order to solve the above problems, the present invention provides a bonding material for antifreeze soft soil, which includes the following components by weight: 40-60 parts of modified steel slag powder, 10-25 parts of sodium hydroxide, 8-15 parts of sodium carbonate, 8-15 parts of modified waste gypsum, and 3-8 parts of cement.

[0007] In some embodiments, the modified steel slag powder is prepared by the following method:

[0008] The steel slag powder, organic silane and propylene glycol triglycidyl ether are mixed, heated to 50° C. to 55° C. and stirred for 30 min to 45 min to obtain modified steel slag powder.

[0009] In some embodiments, the amount of steel slag powder added: the amount of organosilane added: the amount of propylene glycol triglycidyl ether added is (40-45): (20-25): (40-45).

[0010] In some embodiments, the particle size of the steel slag powder is less than 0.15 mm;

[0011] The activity index of the steel slag powder is greater than 50%.

[0012] In some embodiments, the modified waste gypsum is prepared by the following method:

[0013] Mixing the waste gypsum and the sodium hydroxide solution, and reacting them at 50° C. to 55° C. for a first preset time to obtain alkalized waste gypsum;

[0014] Add hexadecyltrimethylammonium bromide to the alkalized waste gypsum, react at 50°C to 55°C for a second preset time, adjust the pH value to neutral after the reaction is completed, then precipitate and filter the reaction product in anhydrous ethanol, dry and grind the filtered precipitate to obtain modified waste gypsum.

[0015] In some embodiments, the amount of the sodium hydroxide solution added is 20% to 30% of the amount of the waste gypsum added.

[0016] The added amount of the hexadecyltrimethylammonium bromide is 3% to 6% of the added amount of the waste gypsum.

[0017] In some embodiments, the waste gypsum is phosphogypsum;

[0018] The first preset time is 1h to 2h;

[0019] The second preset time is 3 hours to 5 hours.

[0020] In some embodiments, the sodium hydroxide is white granular sodium hydroxide, and the effective ingredient content is greater than 98%.

[0021] The anhydrous sodium carbonate is white powdered anhydrous sodium carbonate, and the effective ingredient is greater than 99%;

[0022] The strength grade of the silicate cement is not less than 42.5.

[0023] To solve the above problem, the present invention provides a method for preparing a binder material for antifreeze soft soil, comprising the following steps: mixing 40 to 60 parts of modified steel slag powder, 10 to 25 parts of sodium hydroxide, 8 to 15 parts of sodium carbonate, 8 to 15 parts of modified waste gypsum, and 3 to 8 parts of cement, by weight, to obtain a binder material for antifreeze soft soil.

[0024] And the application of the above-mentioned cementing material for antifreeze soft soil in the solidification of antifreeze soft soil.

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

[0026] The cementing material for antifreeze soft soil provided by the present invention significantly reduces the amount of cement by 90%, greatly reducing carbon emissions. Moreover, the added sodium hydroxide, sodium carbonate, and modified waste gypsum can all react chemically with the modified steel slag powder to generate expansive substances, wherein sodium hydroxide can react with the calcium oxide in the modified steel slag powder to generate expansive source calcium hydroxide; sodium carbonate can react with the calcium oxide in the modified steel slag powder to generate expansive source calcium carbonate; modified waste gypsum can react with sodium hydroxide and modified steel slag powder to generate expansive source calcium aluminate; in addition, the free calcium oxide in the modified steel slag powder can react with water to generate expansive source calcium hydroxide. The four expansive sources simultaneously fill the pores existing in large quantities in the solidified soft soil, significantly improve the density of the solidified soft soil, reduce the water infiltration space, and thus greatly reduce freeze-thaw damage. DETAILED DESCRIPTION

[0027] In order to make the purpose, technical scheme and advantages of the present invention clearer, the present invention is further described in detail below in conjunction with embodiment. The same or similar reference numerals throughout the described embodiment represent the same or similar elements or elements with the same or similar functions. The following is exemplary by reference to the embodiment, which is only used to explain the present invention and is not to be construed as limiting the present invention. In addition, it should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0028] In the description of the present invention, it is necessary to understand that the terms "length", "width", "up", "down", "left", "right", "horizontal", "top", "bottom" and the like indicating directions or positional relationships are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore should not be understood as a limitation on the present invention.

[0029] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0030] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection, an electrical connection, or mutual communication; it can be a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0031] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0032] The disclosure below provides many different embodiments or examples to realize different structures of the present invention. In order to simplify the disclosure of the present invention, the parts and settings of specific examples are described below. Of course, they are only examples, and the purpose is not to limit the present invention. In addition, the present invention can repeat reference numbers and / or reference letters in different examples, and this repetition is for the purpose of simplification and clarity, which itself does not indicate the relationship between the various embodiments and / or settings discussed. In addition, the examples of various specific processes and materials provided by the present invention, but those of ordinary skill in the art can be aware of the application of other processes and / or the use of other materials.

[0033] In the present invention, "preferred" and "better" are only used to describe implementation methods or embodiments with better effects, and it should be understood that they do not constitute a limitation on the scope of protection of the present invention. In the present invention, the technical features described in an open manner include closed technical solutions composed of the listed features, and also include open technical solutions containing the listed features. In the present invention, when involving numerical ranges, unless otherwise specified, the two endpoints of the numerical range are included.

[0034] The invention provides a cementing material for antifreeze soft soil, which comprises the following components by weight: 40-60 parts of modified steel slag powder, 10-25 parts of sodium hydroxide, 8-15 parts of sodium carbonate, 8-15 parts of modified waste gypsum and 3-8 parts of cement.

[0035] The cementing material for antifreeze soft soil provided by the present invention significantly reduces the amount of cement by 90%, greatly reducing carbon emissions. Moreover, the added sodium hydroxide, sodium carbonate, and modified waste gypsum can all react chemically with the modified steel slag powder to generate expansive substances, wherein sodium hydroxide can react with the calcium oxide in the modified steel slag powder to generate expansive source calcium hydroxide; sodium carbonate can react with the calcium oxide in the modified steel slag powder to generate expansive source calcium carbonate; modified waste gypsum can react with sodium hydroxide and modified steel slag powder to generate expansive source calcium aluminate; in addition, the free calcium oxide in the modified steel slag powder can react with water to generate expansive source calcium hydroxide. The four expansive sources simultaneously fill the pores existing in large quantities in the solidified soft soil, significantly improve the density of the solidified soft soil, reduce the water infiltration space, and thus greatly reduce freeze-thaw damage.

[0036] The following is a further description of the components and characteristics of the cementing material for antifreeze soft soil provided by the present invention:

[0037] In some embodiments, exemplary weight portions of the modified steel slag powder are 42 parts, 44 parts, 46 parts, 48 ​​parts, 50 parts, 52 parts, 54 parts, 56 parts, and 58 parts, but are not limited to the above enumeration.

[0038] In some embodiments, the modified steel slag powder is a modified steel slag powder with organic silane grafted on the surface.

[0039] Furthermore, in some embodiments, the modified steel slag powder is prepared by the following method:

[0040] The steel slag powder, organic silane and propylene glycol triglycidyl ether are mixed, heated to 50° C. to 55° C. and stirred for 30 min to 45 min to obtain modified steel slag powder.

[0041] Preferably, the addition amount of steel slag powder: the addition amount of organosilane: the addition amount of propylene glycol triglycidyl ether is (40-45): (20-25): (40-45). Under this condition, it can be ensured that the surface of the modified steel slag powder is grafted with an appropriate amount of organosilane.

[0042] Steel slag powder is an industrial waste in the crude steel production process. Steel slag powder mainly comes from oxides formed by oxidation of various elements in the metal furnace charge, such as oxides of silicon, aluminum, and manganese, as well as impurities such as mud and sand brought into the metal charge, added slag-making materials, iron ore, sintered ore, and iron oxide scale used as oxidants or coolants, etc. Preferably, the particle size of the steel slag powder is less than 0.15 mm; the activity index of the steel slag powder is greater than 50%. Under this condition, it can be ensured that the modified steel slag powder has sufficient effective components such as CaO, SiO2, Al2O3, and FeO.

[0043] It should be noted that, in the above-mentioned embodiment, the modified steel slag powder is modified to obtain the modified steel slag powder with surface grafted organosilane, so that the organosilane can be evenly embedded in the interior of the cement structure along with the steel slag particles, so that the soil binder solidified soil with the modified steel slag powder as the main component has an excellent hydrophobic effect from the inside to the outside. Under the action of freeze-thaw cycles, it is difficult for moisture to enter the interior of the solidified soil structure, thereby greatly reducing freeze-thaw damage.

[0044] In some embodiments, exemplary weight portions of the modified waste gypsum are 8 parts, 9 parts, 10 parts, 11 parts, 12 parts, 13 parts, 14 parts, and 15 parts, but are not limited to the above enumeration.

[0045] In some embodiments, the modified waste gypsum is etherified modified waste gypsum. Further, in some embodiments, the modified waste gypsum is prepared by the following method:

[0046] Mixing the waste gypsum and the sodium hydroxide solution, and reacting them at 50° C. to 55° C. for a first preset time to obtain alkalized waste gypsum;

[0047] Add hexadecyltrimethylammonium bromide to the alkalized waste gypsum, react at 50°C to 55°C for a second preset time, adjust the pH value to neutral after the reaction is completed, then precipitate and filter the reaction product in anhydrous ethanol, dry and grind the filtered precipitate to obtain modified waste gypsum.

[0048] Preferably, the amount of the sodium hydroxide solution added is 20% to 30% of the amount of the waste gypsum added. The amount of the hexadecyltrimethylammonium bromide added is 3% to 6% of the amount of the waste gypsum added; the first preset time is 1h to 2h; the second preset time is 3h to 5h. Under these conditions, it can be ensured that an appropriate amount of waste gypsum participates in etherification modification to obtain an appropriate amount of etherified modified waste gypsum.

[0049] Preferably, the waste gypsum is phosphogypsum. Phosphogypsum is mainly a solid waste generated in the wet phosphoric acid process. The main component of phosphogypsum is calcium sulfate dihydrate, and the content is generally between 85% and 90%. Moreover, phosphogypsum accounts for the majority of the total amount of waste gypsum. The resource utilization of phosphogypsum is of great benefit to the comprehensive utilization of waste gypsum.

[0050] It should be noted that the surface of the etherified waste gypsum has long-chain groups, which are embedded in the gel structure, which can not only improve the curing fastness of the cementing material, but also block water penetration, increase the hydrophobicity of the solidified soft soil, thereby reducing the absorption capacity of the solidified soft soil to water, thereby reducing freeze-thaw damage. In some embodiments, the surface of the modified steel slag powder modified by the above specific method has a negative charge, and the surface of the modified waste gypsum modified by the above specific method has a positive charge. The two may have electrostatic interaction, thereby generating agglomeration, and the soft soil particles are gradually adsorbed to the surface of the cementing material, and under the sweeping and entrainment of the long chain structure of the cementing material, more soft soil particles are entrained into the agglomerates of the cementing material to promote the formation of larger agglomerates, thereby improving the curing ability of the cementing material with the modified steel slag powder as the main component.

[0051] In some embodiments, the exemplary weight parts of the sodium hydroxide are 12 parts, 14 parts, 16 parts, 18 parts, 20 parts, 22 parts, 24 parts, not limited to the above list; the sodium hydroxide is white granular sodium hydroxide, and the effective component is greater than 98%. Sufficient sodium hydroxide can generate expansion source calcium hydroxide with calcium oxide in the modified steel slag powder.

[0052] In some embodiments, exemplary weight portions of the anhydrous sodium carbonate are 8 parts, 9 parts, 10 parts, 11 parts, 12 parts, 13 parts, and 14 parts, not limited to the above enumeration; the anhydrous sodium carbonate is anhydrous sodium carbonate in white powder form, and the effective ingredient is greater than 99%; sufficient sodium carbonate can react with the calcium oxide in the modified steel slag powder to generate expansion source calcium carbonate.

[0053] In some embodiments, the exemplary weight parts of the silicate cement are 3 parts, 4 parts, 5 parts, 6 parts, 7 parts, and 8 parts, not limited to the above list; the strength grade of the silicate cement is not less than 42.5. The cementing material for antifreeze soft soil provided by the present invention significantly reduces the amount of cement by 90%, greatly reducing carbon emissions.

[0054] Accordingly, the present invention also provides a method for preparing a cementing material for antifreeze soft soil, comprising the following steps:

[0055] In parts by weight, 40 to 60 parts of modified steel slag powder, 10 to 25 parts of sodium hydroxide, 8 to 15 parts of sodium carbonate, 8 to 15 parts of modified waste gypsum, and 3 to 8 parts of cement are mixed to obtain a binder material for antifreeze soft soil. In some embodiments, the mixing process is stirred at a rate of not less than 50 revolutions per second.

[0056] And, the application of the above-mentioned cementing material for antifreeze soft soil in the solidification of antifreeze soft soil. In some embodiments, at the construction site such as the mixing pile, water is added and stirred to prepare a cementing material slurry for antifreeze soft soil that meets the water-cement ratio requirements, and the slurry is pumped into the soil body with a mixing machine to form solidified soil.

[0057] The present invention is further described below with reference to specific embodiments.

[0058] Example 1

[0059] The present embodiment provides a bonding material for antifreeze soft soil, which includes the following components in parts by weight: 60 parts of modified steel slag powder, 12 parts of sodium hydroxide, 13 parts of sodium carbonate, 10 parts of modified waste gypsum, and 5 parts of cement.

[0060] The modified steel slag powder is prepared by the following method:

[0061] Steel slag powder, organosilane and propylene glycol triglycidyl ether were mixed, heated to 50° C. and stirred for 35 minutes to obtain modified steel slag powder, wherein the ratio of the added amount of steel slag powder: the added amount of organosilane: the added amount of propylene glycol triglycidyl ether was 2:1:2.

[0062] The modified waste gypsum is prepared by the following method:

[0063] The waste gypsum and the sodium hydroxide solution are mixed and reacted at 50° C. for 1 hour to obtain alkalized waste gypsum;

[0064] Adding hexadecyltrimethylammonium bromide to the alkalized waste gypsum, reacting at 50°C for 3h, adjusting the pH value to neutral after the reaction is completed, and then precipitating and filtering the reaction product in anhydrous ethanol, drying and grinding the filtered precipitate to obtain modified waste gypsum. The amount of the sodium hydroxide solution added is 25% of the amount of the waste gypsum added, and the amount of the hexadecyltrimethylammonium bromide added is 5% of the amount of the waste gypsum added.

[0065] Example 2

[0066] The present embodiment provides a bonding material for antifreeze soft soil, which includes the following components in parts by weight: 52 parts of modified steel slag powder, 10 parts of sodium hydroxide, 15 parts of sodium carbonate, 15 parts of modified waste gypsum, and 8 parts of cement.

[0067] The modified steel slag powder is prepared by the following method:

[0068] Steel slag powder, organosilane and propylene glycol triglycidyl ether were mixed, heated to 50° C. and stirred for 35 minutes to obtain modified steel slag powder, wherein the ratio of the added amount of steel slag powder: the added amount of organosilane: the added amount of propylene glycol triglycidyl ether was 2:1:2.

[0069] The modified waste gypsum is prepared by the following method:

[0070] The waste gypsum and the sodium hydroxide solution are mixed and reacted at 50° C. for 1 hour to obtain alkalized waste gypsum;

[0071] Adding hexadecyltrimethylammonium bromide to the alkalized waste gypsum, reacting at 50°C for 3h, adjusting the pH value to neutral after the reaction is completed, and then precipitating and filtering the reaction product in anhydrous ethanol, drying and grinding the filtered precipitate to obtain modified waste gypsum. The amount of the sodium hydroxide solution added is 25% of the amount of the waste gypsum added, and the amount of the hexadecyltrimethylammonium bromide added is 5% of the amount of the waste gypsum added.

[0072] Example 3

[0073] The present embodiment provides a bonding material for antifreeze soft soil, which includes the following components in parts by weight: 50 parts of modified steel slag powder, 20 parts of sodium hydroxide, 5 parts of sodium carbonate, 10 parts of modified waste gypsum, and 5 parts of cement.

[0074] The modified steel slag powder is prepared by the following method:

[0075] Steel slag powder, organosilane and propylene glycol triglycidyl ether were mixed, heated to 50° C. and stirred for 35 minutes to obtain modified steel slag powder, wherein the ratio of the added amount of steel slag powder: the added amount of organosilane: the added amount of propylene glycol triglycidyl ether was 2:1:2.

[0076] The modified waste gypsum is prepared by the following method:

[0077] The waste gypsum and the sodium hydroxide solution are mixed and reacted at 50° C. for 1 hour to obtain alkalized waste gypsum;

[0078] Adding hexadecyltrimethylammonium bromide to the alkalized waste gypsum, reacting at 50°C for 3h, adjusting the pH value to neutral after the reaction is completed, and then precipitating and filtering the reaction product in anhydrous ethanol, drying and grinding the filtered precipitate to obtain modified waste gypsum. The amount of the sodium hydroxide solution added is 25% of the amount of the waste gypsum added, and the amount of the hexadecyltrimethylammonium bromide added is 5% of the amount of the waste gypsum added.

[0079] Example 4

[0080] The present embodiment provides a bonding material for antifreeze soft soil, which includes the following components in parts by weight: 40 parts of modified steel slag powder, 25 parts of sodium hydroxide, 15 parts of sodium carbonate, 15 parts of modified waste gypsum, and 5 parts of cement.

[0081] The modified steel slag powder is prepared by the following method:

[0082] Steel slag powder, organosilane and propylene glycol triglycidyl ether were mixed, heated to 50° C. and stirred for 35 minutes to obtain modified steel slag powder, wherein the ratio of the added amount of steel slag powder: the added amount of organosilane: the added amount of propylene glycol triglycidyl ether was 2:1:2.

[0083] The modified waste gypsum is prepared by the following method:

[0084] The waste gypsum and the sodium hydroxide solution are mixed and reacted at 50° C. for 1 hour to obtain alkalized waste gypsum;

[0085] Adding hexadecyltrimethylammonium bromide to the alkalized waste gypsum, reacting at 50°C for 3h, adjusting the pH value to neutral after the reaction is completed, and then precipitating and filtering the reaction product in anhydrous ethanol, drying and grinding the filtered precipitate to obtain modified waste gypsum. The amount of the sodium hydroxide solution added is 25% of the amount of the waste gypsum added, and the amount of the hexadecyltrimethylammonium bromide added is 5% of the amount of the waste gypsum added.

[0086] Comparative Example 1

[0087] This comparative example provides a bonding material for antifreeze soft soil, which includes the following components in parts by weight: 60 parts of unmodified steel slag powder, 12 parts of sodium hydroxide, 13 parts of sodium carbonate, 10 parts of modified waste gypsum, and 5 parts of cement.

[0088] The modified waste gypsum is prepared by the following method:

[0089] The waste gypsum and the sodium hydroxide solution are mixed and reacted at 50° C. for 1 hour to obtain alkalized waste gypsum;

[0090] Adding hexadecyltrimethylammonium bromide to the alkalized waste gypsum, reacting at 50°C for 3h, adjusting the pH value to neutral after the reaction is completed, and then precipitating and filtering the reaction product in anhydrous ethanol, drying and grinding the filtered precipitate to obtain modified waste gypsum. The amount of the sodium hydroxide solution added is 25% of the amount of the waste gypsum added, and the amount of the hexadecyltrimethylammonium bromide added is 5% of the amount of the waste gypsum added.

[0091] Comparative Example 2

[0092] This comparative example provides a bonding material for antifreeze soft soil, which includes the following components in parts by weight: 60 parts of modified steel slag powder, 12 parts of sodium hydroxide, 13 parts of sodium carbonate, and 5 parts of cement.

[0093] The modified steel slag powder is prepared by the following method:

[0094] Steel slag powder, organosilane and propylene glycol triglycidyl ether were mixed, heated to 50° C. and stirred for 35 minutes to obtain modified steel slag powder, wherein the ratio of the added amount of steel slag powder: the added amount of organosilane: the added amount of propylene glycol triglycidyl ether was 2:1:2.

[0095] Comparative Example 3

[0096] This comparative example provides a bonding material for antifreeze soft soil, which includes the following components in parts by weight: 60 parts of modified steel slag powder, 12 parts of sodium hydroxide, 10 parts of modified waste gypsum, and 5 parts of cement.

[0097] The modified steel slag powder is prepared by the following method:

[0098] Steel slag powder, organosilane and propylene glycol triglycidyl ether were mixed, heated to 50° C. and stirred for 35 minutes to obtain modified steel slag powder, wherein the ratio of the added amount of steel slag powder: the added amount of organosilane: the added amount of propylene glycol triglycidyl ether was 2:1:2.

[0099] The modified waste gypsum is prepared by the following method:

[0100] The waste gypsum and the sodium hydroxide solution are mixed and reacted at 50° C. for 1 hour to obtain alkalized waste gypsum;

[0101] Adding hexadecyltrimethylammonium bromide to the alkalized waste gypsum, reacting at 50°C for 3h, adjusting the pH value to neutral after the reaction is completed, and then precipitating and filtering the reaction product in anhydrous ethanol, drying and grinding the filtered precipitate to obtain modified waste gypsum. The amount of the sodium hydroxide solution added is 25% of the amount of the waste gypsum added, and the amount of the hexadecyltrimethylammonium bromide added is 5% of the amount of the waste gypsum added.

[0102] The soft soil was solidified by using the cementing materials for antifreeze soft soil prepared in Examples 1 to 4 and Comparative Examples 1 to 3 to obtain soil cementing material solidified soil, and the moisture content, porosity and antifreeze performance of the soil cementing material solidified soil were tested. Among them, the moisture content is the mass loss rate measured by drying the surface moisture of the soil cementing material solidified soil after curing it to the age under standard curing conditions, crushing it into particles less than 4.75 mm, and baking it at 60°C for 24 hours, which is the moisture content of the solidified soil; the unconfined compressive strength is tested according to the "Cement Soil Mix Design Code" JGJ / T 233; the porosity is tested by CT tomography and calculated by software processing; the permeability coefficient test and freeze-thaw cycle test refer to the "Highway Geotechnical Test Code" (JTG 3430-2020).

[0103] The test results of Examples 1 to 4 and Comparative Examples 1 to 3 are shown in Table 1.

[0104] Table 1 Test results of Examples 1 to 4 and Comparative Examples 1 to 3

[0105]

[0106] As shown in Table 1, by comparing Examples 1 to 4 with Comparative Examples 1 to 3, it can be seen that the addition of modified steel slag powder, modified waste gypsum and sodium carbonate plays a vital role in improving the solidified soft soil and its anti-freeze-thaw performance. The binder material for antifreeze soft soil provided in Examples 1 to 4 can significantly reduce the amount of cement used, and make the solidified soft soil have a good anti-freeze-thaw cycle effect. It is a green soil binder that can replace cement for soft soil solidification related projects in areas with large temperature differences between day and night, and can be widely used in the fields of mixing piles / jet grouting piles, in-situ solidification, etc.

[0107] In the description of this specification, the description with reference to the terms "some embodiments", "illustrative embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiments or examples are included in at least one embodiment or example of the present application. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0108] The above disclosure is only a preferred embodiment of the present invention, which certainly cannot be used to limit the scope of the present invention. Therefore, equivalent changes made according to the claims of the present invention are still within the scope of the present invention.

Claims

1. A cementing material for antifreeze soft soil, characterized in that: The invention comprises the following components in parts by weight: 40-60 parts of modified steel slag powder, 10-25 parts of sodium hydroxide, 8-15 parts of sodium carbonate, 8-15 parts of modified waste gypsum and 3-8 parts of cement.

2. The cementing material for antifreeze soft soil according to claim 1, characterized in that: The modified steel slag powder is prepared by the following method: The steel slag powder, organic silane and propylene glycol triglycidyl ether are mixed, heated to 50° C. to 55° C. and stirred for 30 min to 45 min to obtain modified steel slag powder.

3. The cementing material for antifreeze soft soil according to claim 2, characterized in that: The addition amount of the steel slag powder: the addition amount of the organosilane: the addition amount of propylene glycol triglycidyl ether is (40-45): (20-25): (40-45).

4. The cementing material for antifreeze soft soil according to claim 2, characterized in that: The particle size of the steel slag powder is less than 0.15 mm; The activity index of the steel slag powder is greater than 50%.

5. The cementing material for antifreeze soft soil according to claim 1, characterized in that: The modified waste gypsum is prepared by the following method: Mixing the waste gypsum and the sodium hydroxide solution, and reacting them at 50° C. to 55° C. for a first preset time to obtain alkalized waste gypsum; Add hexadecyltrimethylammonium bromide to the alkalized waste gypsum, react at 50°C to 55°C for a second preset time, adjust the pH value to neutral after the reaction is completed, then precipitate and filter the reaction product in anhydrous ethanol, dry and grind the filtered precipitate to obtain modified waste gypsum.

6. The cementing material for antifreeze soft soil according to claim 5, characterized in that: The amount of the sodium hydroxide solution added is 20% to 30% of the amount of the waste gypsum added. The added amount of the hexadecyltrimethylammonium bromide is 3% to 6% of the added amount of the waste gypsum.

7. The cementing material for antifreeze soft soil according to claim 5, characterized in that: The waste gypsum is phosphogypsum; The first preset time is 1h to 2h; The second preset time is 3 hours to 5 hours.

8. The cementing material for antifreeze soft soil according to claim 1, characterized in that: The sodium hydroxide is white granular sodium hydroxide, and the effective component is greater than 98%. The anhydrous sodium carbonate is white powdered anhydrous sodium carbonate, and the effective ingredient is greater than 99%; The strength grade of the silicate cement is not less than 42.

5.

9. A method for preparing a cementing material for antifreeze soft soil according to any one of claims 1 to 8, characterized in that: The following steps are involved: In parts by weight, 40-60 parts of modified steel slag powder, 10-25 parts of sodium hydroxide, 8-15 parts of sodium carbonate, 8-15 parts of modified waste gypsum and 3-8 parts of cement are mixed to obtain a binder material for antifreeze soft soil.

10. Use of the cementing material for frost-resistant soft soil according to any one of claims 1 to 8 in the solidification of frost-resistant soft soil.

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