A cementing material for curing high-water-content silt soft soil and a preparation method and application thereof

Abstract

The present application relates to the technical field of building materials, and particularly relates to a cementing material for curing high-water-content silt soft soil and a preparation method and application thereof, the cementing material comprises the following components in percentage by weight: 15-40% of Portland cement, 20-45% of mineral powder, 5-20% of bentonite, 10-30% of zeolite powder, 2-10% of metakaolin and 0.5-6% of activator. The cementing material has simple components and excellent curing performance for high-water-content silt soft soil. The Portland cement, the mineral powder, the bentonite, the zeolite powder, the metakaolin and the activator are mixed in proportion to obtain the cementing material, which has good curing effect for high-water-content silt soft soil, can realize uniform curing, and has high strength and good anti-permeability of the cured silt soft soil, and promotes the strength development of high-water-content silt soft soil, and is suitable for curing silt soft soil with water content higher than 60%.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of building materials, in particular to a cementing material for curing high-water-content silt soft soil and a preparation method and application thereof. BACKGROUND

[0002] In the areas where soft foundation is widely distributed, such as the Pearl River Delta, if the soft foundation is not properly treated, it will affect the safety and stability of the upper structure. In the traditional treatment method, cement reinforcement method is widely used in soft foundation reinforcement due to its advantages such as convenient construction, but for high-water-content silt soft soil, the cement reinforcement method often has low curing strength and slow strength development, and it is still difficult to achieve good reinforcement effect at a high dosage. Therefore, developing a cementing material for curing high-water-content silt soft soil is of great significance for improving the reinforcement strength of high-water-content silt soft soil, improving the engineering quality of soft foundation reinforcement, ensuring the safety, stability and durability of the upper structure.

[0003] Chinese patent application CN117645455A discloses a dredged silt curing material and a pipeline curing filling method. The curing material is composed of sea sand, drag-reducing material, anti-erosion hydraulic cementitious material, dispersing material, early-strength material and water-reducing material. The anti-erosion hydraulic cementitious material is composed of cement and mineral admixture, and the water-reducing material can be one or more of zeolite, calcium-based bentonite, sepiolite and diatomite. The sea sand large particle material provides skeleton support for the later curing reaction, improves the curing strength and the later foundation settlement, and the anti-erosion hydraulic cementitious material and the water-reducing material improve the anti-erosion strength of the cured dredged silt and reduce the cracking and expansion of the cured silt body. However, the composition of raw materials is relatively large, and the unconfined compressive strength still needs to be further improved. SUMMARY

[0004] The technical problem to be solved by the present application is to provide a cementing material for curing high-water-content silt soft soil and a preparation method and application thereof. The cementing material is suitable for curing silt soft soil with a water content of more than 60%, and has good strength and anti-permeability.

[0005] To solve the above technical problems, the present application provides a cementing material for curing high-water-content silt soft soil. The composition of the cementing material includes, by weight percentage, 15-40% of Portland cement, 20-45% of mineral powder, 5-20% of bentonite, 10-30% of zeolite powder, 2-10% of metakaolin and 0.5-6% of activator.

[0006] As an improvement of the above-mentioned scheme, the high-water-content silt soft soil is silt soft soil with a water content of 60-150% and an organic matter content of 5-10%.

[0007] As an improvement of the above-mentioned scheme, the activator is sodium sulfate.

[0008] As an improvement of the above scheme, the fineness of the zeolite powder is less than or equal to 10% of 80 μm square mesh sieve, the ammonium adsorption value is greater than or equal to 100 mmol / 100g, and the 28-day compressive strength ratio of the zeolite powder cement mortar is greater than or equal to 70%.

[0009] As an improvement of the above scheme, the pore size of the zeolite powder satisfies the following relationship:

[0010] (D10+D50) / D90=1.0-1.6;

[0011] D90 / S=2.6-3.5;

[0012] wherein D10 is the corresponding pore size when the cumulative distribution of the zeolite powder is 10%, D50 is the corresponding pore size when the cumulative distribution of the zeolite powder is 50%, and D90 is the corresponding pore size when the cumulative distribution of the zeolite powder is 90%, and the unit is nm;

[0013] S is the specific surface area, and the unit is m 2 / g.

[0014] As an improvement of the above scheme, the chemical composition of the bentonite satisfies the following relationship:

[0015]

[0016] wherein k1 is a constant, and the value range is 1.05-1.1, and k2 is a constant, and the value range is 1.3-1.5;

[0017] n(Na + ) is the exchangeable Na + molar content in the bentonite; n(Ca 2+ ) is the exchangeable Ca 2+ molar content in the bentonite; w(Na2O) is the mass fraction of Na2O measured in the bentonite; w(K2O) is the mass fraction of K2O measured in the bentonite; w(CaO) is the mass fraction of CaO measured in the bentonite; and w(MgO) is the mass fraction of MgO measured in the bentonite;

[0018] The fineness of the bentonite is 200-600 mesh.

[0019] As an improvement of the above scheme, the weight ratio of the zeolite powder to the bentonite is 1:(0.3-0.7).

[0020] As an improvement of the above scheme, the metakaolin is calcined metakaolin, and the fineness of the metakaolin is 200-500 mesh.

[0021] The activity index of the mineral powder reaches 95% or more at 28 days.

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

[0023] The second aspect of the present application provides a preparation method of the cementing material for curing high-water-content sludge soft soil, and the steps include:

[0024] (1) Portland cement, mineral powder, bentonite, zeolite powder, metakaolin and activator are weighed by parts by weight for use;

[0025] (2) The portland cement, mineral powder, bentonite, zeolite powder, metakaolin and activator are mixed uniformly, and the cementing material is obtained.

[0026] The third aspect of the present application provides an application of the cementing material for curing high-water-content sludge soft soil in curing high-water-content sludge soft soil, and the use method is as follows:

[0027] The cementing material is mixed with water to form a cementing material slurry, and then is uniformly stirred with high-water-content sludge soft soil, wherein the mixing ratio of the cementing material to water in the cementing material slurry is 1: (0.6-0.8).

[0028] The present application has the following beneficial effects:

[0029] The cementing material in the present application has simple components and excellent curing performance for high-water-content sludge soft soil. The cementing material obtained by mixing and compounding the portland cement, mineral powder, bentonite, zeolite powder, metakaolin and activator in a certain proportion has good curing effect for high-water-content sludge soft soil, can realize uniform curing, and the cured sludge soft soil has high strength and good impermeability, and promotes the strength development of high-water-content sludge soft soil.

[0030] The portland cement can first have a rapid hydration reaction with water in high-water-content sludge to form a gel-like substance, and the addition of the mineral powder, metakaolin and activator can help to improve the slurry fluidity and workability of the sludge soft soil cementing material, improve the uniformity of the mixing of the curing material and sludge soft soil, and improve the strength of the cured sludge soil. The addition of the bentonite and zeolite powder can reduce the decay effect of the hydration strength of the curing material due to excessive water content, and further increase the curing strength. DETAILED DESCRIPTION

[0031] In order to make the purpose, technical scheme and advantages of the present application clearer, the present application will be further described in detail with specific examples.

[0032] To solve the above problems, the present application provides a cementing material for curing high water content sludge soft soil, the components of the cementing material include Portland cement 15-40%, mineral powder 20-45%, bentonite 5-20%, zeolite powder 10-30%, metakaolin 2-10% and activator 0.5-6% by weight percentage.

[0033] In the present application, the Portland cement, mineral powder, bentonite, zeolite powder, metakaolin and activator are mixed in proportion to form the cementing material, which has good curing effect on high water content sludge soft soil, can realize uniform curing, and the cured sludge soft soil has high strength and good impermeability, and promotes the strength development of high water content sludge soft soil. The Portland cement can first have rapid hydration reaction with water in the high water content sludge to form gel-like material, the addition of mineral powder, metakaolin and activator can help to improve the slurry fluidity and workability of the sludge soft soil cementing material, improve the uniformity of the mixing of the curing material and sludge soft soil, and improve the strength of the cured sludge soil, and the addition of bentonite and zeolite powder can reduce the decay effect of high water content on the hydration strength of the curing material, thereby increasing the curing strength.

[0034] The soft soil in the Pearl River Delta and other regions has the characteristics of high water content, low strength, poor permeability and high compressibility, which affects the stability and consolidation rate of the soft foundation, and the organic matter in the sludge inhibits the hydration of cement. In the present application, the high water content sludge soft soil has a water content of more than 60%, and further has a water content of 60-150% and an organic matter content of 5-10%.

[0035] Preferably, the strength grade of the Portland cement is not less than 42.5, and the Portland cement with strength grade of 42.5, 42.5R, 52.5, 52.5R, 62.5, 62.5R can be selected to ensure that the Portland cement contains a lot of tricalcium silicate to promote the hydration reaction and obtain high-strength cured soft foundation. Specifically, the dosage of the Portland cement is exemplarily 15%, 20%, 25%, 30%, 35% or 40% by weight percentage, but is not limited thereto.

[0036] Further, the mineral powder and the metakaolin can be used as mineral admixtures, which have high pozzolanic activity. In the alkaline environment, the mineral powder and the metakaolin can react to generate a large amount of C-S-H gel, thereby forming strength and further improving the strength of the cured material. The activity index of the mineral powder is greater than 95% at 28 days, i.e., the selected mineral powder is not less than S95 grade. The metakaolin is calcined metakaolin, and the active ingredient of the calcined metakaolin is more likely to react with Ca(OH)2 precipitated in the cement hydration process to generate a product with gel properties, thereby reducing the initial setting and final setting time of the cement paste. The fineness of the metakaolin is 200-500 mesh, and the specific surface area is suitable for more effective participation in the hydration reaction, thereby improving the strength of the cured material. The S95 grade mineral powder, the calcined metakaolin with a fineness of 200-500 mesh, and the activator can be synergistically combined to improve the paste fluidity and workability of the silt soft soil cementing material, and to improve the uniformity of the mixing of the cured material and the silt soft soil. Specifically, the dosage of the mineral powder is exemplarily 20%, 25%, 30%, 35%, 40%, or 45%, but is not limited thereto; and the dosage of the metakaolin is exemplarily 2 parts, 5 parts, 7 parts, 9 parts, or 10 parts, but is not limited thereto.

[0037] In some specific and preferred embodiments, the activator is sodium sulfate. The incorporation of sodium sulfate can activate the mineral powder, the metakaolin, and the zeolite powder. The sulfate ions react with the calcium phase and the aluminum phase to generate a large amount of AFt, thereby improving the hydration strength of the cementing material. In addition, sodium sulfate can improve the paste fluidity and permeability, enhance the uniformity of the mixing of the cementing material and the soft soil particles, and make the hydration products form a dense network structure to wrap the soft soil particles, thereby improving the strength of the cured silt soil. Sodium sulfate can be synergistically combined with the portland cement, the mineral powder, the bentonite, the zeolite powder, and the metakaolin in the system to obtain a cementing material suitable for high-moisture silt soft soil and having excellent curing strength. Specifically, the dosage of the activator is exemplarily 0.5%, 1%, 2%, 3%, 4%, 5%, or 6%, but is not limited thereto. More preferably, the dosage of the activator is 2-4%.

[0038] The bentonite in the application can react with Ca(OH)2 to generate C-S-H gel and C-A-H and the like, form strength, and reinforce the soil body; secondly, the bentonite can adsorb the excessive free water in the high water content silt soil, reduce the attenuation of the hydration strength of the cementing material due to the excessive water content, and swell by absorbing water, and the hydration product extrudes and fills the soil body pores, and enhances the compactness of the soil body skeleton; finally, the active oxide contained in the bentonite can catalyze the hydration of each cementing material, accelerate the generation of the hydration product, improve the early strength, and promote the strength development of the high water content silt soft soil. Moreover, the zeolite powder belongs to a pozzolanic material, has a pozzolanic effect, can generate C-S-H gel by hydration reaction in an alkaline environment, and the incorporation of the zeolite powder is beneficial to improving the compactness and strength. The zeolite powder has a large number of nanoscale pores inside, can adsorb the excessive free water in the silt soil, and improve the strength of the solidified silt soil. However, the water absorption of the cementing material is too high, which can inhibit the hydration reaction of the cement, prolong the setting and solidification time of the cement, and weaken the soft foundation strength.

[0039] Preferably, the fineness of the zeolite powder is less than or equal to 10% of the 80 μm square hole sieve, the ammonium adsorption value is greater than or equal to 100 mmol / 100 g, and the 28-day compressive strength ratio of the zeolite powder cement mortar is greater than or equal to 70%, that is, the zeolite powder can be selected as a grade II zeolite powder, has good dispersibility, high reactivity, and strong ammonium adsorption capacity, can more effectively react with Ca(OH)2 in the cement, is helpful to further improving the strength and impermeability of the solidified soil body, can more quickly participate in the hydration reaction, shorten the gelation time, improve the strength development of the solidified soil body, and improve the durability of the solidified soil body.

[0040] Further, the pore size of the zeolite powder satisfies the following relationship: (D10+D50) / D90=1.0-1.6; D90 / S=2.6-3.5; wherein D10 is the corresponding pore size when the cumulative distribution of the zeolite powder reaches 10%, D50 is the corresponding pore size when the cumulative distribution of the zeolite powder reaches 50%, D90 is the corresponding pore size when the cumulative distribution of the zeolite powder reaches 90%, the unit is nm, the pore size distribution is obtained by BET test; and S is the specific surface area, the unit is m 2 / g, which is obtained by a multi-station full-automatic specific surface area and pore analyzer.

[0041] By controlling the particle size distribution of the zeolite powder, the zeolite powder can be provided with appropriate water absorption and water retention, and D90 / specific surface area=(2.6-3.5) (nm / m 2 ·g -1), so that the zeolite powder has certain porosity, and more water can be stored in the pores of the appropriate particle size and easily released under certain conditions. When the water content in the cement-based material is reduced to a certain extent, the stored water can be released from the pores to promote the further progress of the hydration reaction, not only can enhance the solidification strength of the soft foundation and promote the early strength development of the soft foundation, but also can further reduce the influence of the addition of zeolite powder particles on the fluidity of the system. In addition, it can also delay the internal self-drying of the material, reduce the shrinkage, and improve the solidification strength and anti-seepage performance of the solidified silt soil.

[0042] The chemical composition of the bentonite satisfies the following relationship:

[0043]

[0044] wherein k1 is a constant, and the value range thereof is 1.05-1.1, and k2 is a constant, and the value range thereof is 1.3-1.5;

[0045] n(Na + ) is the exchangeable Na + molar content in the bentonite; n(Ca 2+ ) is the exchangeable Ca 2+ molar content in the bentonite; the exchangeable Na + , Ca 2+ molar content = measured molar concentration * mass of bentonite, wherein the molar concentration can be obtained by quantitative analysis by EDTA-acetate exchange method.

[0046] w(Na2O) is the mass fraction of Na2O measured in the bentonite; w(K2O) is the mass fraction of K2O measured in the bentonite; w(CaO) is the mass fraction of CaO measured in the bentonite; w(MgO) is the mass fraction of MgO measured in the bentonite; w(Na2O), w(K2O), w(CaO), and w(MgO) are obtained by titration.

[0047] When the chemical composition of the bentonite satisfies the above relationship, it has a suitable cation exchange capacity and can accommodate more pore water. When it is used in combination with the zeolite powder, the fluidity of the system can be improved, and it can be used as part of the cementing material to form strength by hydration. When it is used in the silt soft soil with a water content of 60-150%, most of the free water molecules can be adsorbed, the decay effect of the hydration strength of the solidified material due to excessive water content can be reduced, the initial setting time can be shortened, sufficient hydration reaction can occur in the silt soft soil with a water content of 60-150%, and enough water can be stored in the system and slowly released in the later stage to promote the hydration reaction of the soft foundation, shorten the final setting time, and have the effects of curing and preventing shrinkage, which is beneficial to improving the solidification silt soil strength and anti-seepage performance.

[0048] More preferably, the fineness of the bentonite is 200-600 mesh, and the weight ratio of the zeolite powder to the bentonite is 1:(0.3-0.7). Controlling the weight ratio of the zeolite powder to the bentonite can regulate the fluidity and pore structure of the cementing material, thereby simultaneously improving the unconfined compressive strength and impermeability of the solidified silt soil. Specifically, the weight ratio of the zeolite powder to the bentonite is exemplarily 1:0.3, 1:0.4, 1:0.5, 1:0.6, or 1:0.7, but is not limited thereto.

[0049] Correspondingly, the application further discloses a preparation method of the cementing material for solidifying high-water-content silt soft soil.

[0050] (1) A silicate cement, a mineral powder, a bentonite, a zeolite powder, a metakaolin, and an activator are weighed by weight parts for use;

[0051] (2) The silicate cement, the mineral powder, the bentonite, the zeolite powder, the metakaolin, and the activator are uniformly mixed, and the cementing material is obtained.

[0052] Preferably, in step (2), the stirring speed during the uniform mixing is 40-60 revolutions per second, and the stirring time is not less than 180 seconds until the uniform mixing, and then the cementing material can be sealed in bags or cans.

[0053] Correspondingly, the application further discloses an application of the cementing material for solidifying high-water-content silt soft soil in solidifying high-water-content silt soft soil.

[0054] The cementing material is mixed with water to form a cementing material slurry, and then the cementing material slurry is uniformly stirred with the high-water-content silt soft soil, and the mixing ratio of the cementing material to water in the cementing material slurry is 1:(0.6-0.8).

[0055] Further, the added quality of the cementing material is 10-20% of the quality of the high-water-content silt soft soil.

[0056] Preferably, a powerful stirring device can be used to uniformly stir and mix the cementing material slurry with the soft soil.

[0057] The application is further described below with specific examples:

[0058] Example 1

[0059] The application provides a cementing material for solidifying high-water-content silt soft soil, and the components are as follows by weight parts:

[0060] 42.5R silicate cement 40 parts, S95 grade mineral powder 30 parts, sodium-based bentonite 8 parts, grade II zeolite powder 15 parts, 250-mesh calcined metakaolin powder 5 parts, and activator (sodium sulfate) 2 parts, and the total is 100 parts.

[0061] The preparation method is as follows: 42.5R Portland cement, S95 grade mineral powder, sodium bentonite (fineness of 400 mesh), zeolite powder of grade II, 250 mesh calcined metakaolin and sodium sulfate are weighed according to parts by weight, and then uniformly mixed to obtain the cementing material.

[0062] Example 2

[0063] The cementing material for curing high-water-content silt soft soil provided in this example has the following components in parts by weight:

[0064] 42.5R Portland cement 40 parts, S95 grade mineral powder 30 parts, bentonite 8 parts, zeolite powder 15 parts, 250 mesh calcined metakaolin powder 5 parts and activator (sodium sulfate) 2 parts, a total of 100 parts;

[0065] The zeolite powder has D10 of 15 μm, D50 of 40 μm, D90 of 50 μm, (D10+D50) / D90 = 1.1, specific surface area of 15.2 m 2 / g, and D90 / specific surface area = 3.3.

[0066] The chemical components include n(Na + )= 0.25 mol, k1 = 1.08, n(Ca 2 + )= 0.14 mol, k2 = 1.38, w(Na2O) = 0.25%, w(Ka2O) = 0.14%, w(CaO) = 0.26%, w(MgO) = 4.1%, and w(SiO2) = 95.1% based on 1 kg of bentonite (fineness of 400 mesh).

[0067]

[0068] The preparation method is the same as that in Example 1.

[0069] Example 3

[0070] The cementing material for curing high-water-content silt soft soil provided in this example has the following components in parts by weight:

[0071] 42.5R Portland cement 40 parts, S95 grade mineral powder 30 parts, bentonite 8 parts, zeolite powder 15 parts, 250 mesh calcined metakaolin powder 5 parts and activator (sodium sulfate) 2 parts, a total of 100 parts;

[0072] The zeolite powder has D10 of 15 μm, D50 of 50 μm, D90 of 70 μm, (D10+D50) / D90 = 0.9, specific surface area of 14.3 m 2 / g, and D90 / specific surface area = 4.9.

[0073] Based on 1 kg of bentonite (400 mesh), n(Na) + )=0.25mol, k1=1.08, n(Ca 2+ )=0.14mol, k2=1.38, w(Na2O)=0.25%, w(Ka2O)=0.14%, w(CaO)=0.26%, w(MgO)=4.1%,

[0074]

[0075] The preparation method is the same as in Example 1.

[0076] Example 4

[0077] This embodiment provides a cementing material for solidifying silty soft soil with high water content, the composition of which is as follows by weight:

[0078] 40 parts of 42.5R silicate cement, 30 parts of S95 grade mineral powder, 8 parts of bentonite, 15 parts of zeolite powder, 5 parts of 250 mesh calcined metakaolin powder and 2 parts of activator (sodium sulfate), totaling 100 parts.

[0079] The zeolite powder has a D10 of 15 μm, a D50 of 40 μm, a D90 of 50 μm, and a (D10+D50) / D90 ratio of 1.1; its specific surface area is 15.2 m². 2 / g, D90 / specific surface area = 3.3;

[0080] Based on 1 kg of bentonite (400 mesh), n(Na) + )=0.2mol, k1=1.1, n(Ca 2+ )=0.15mol, k2=1.38, w(Na2O)=0.21%, w(Ka2O)=0.16%, w(CaO)=0.27%, w(MgO)=4.1%,

[0081]

[0082] The preparation method is the same as in Example 1.

[0083] Example 5

[0084] This embodiment provides a cementing material for solidifying silty soft soil with high water content, the composition of which is as follows by weight:

[0085] 25 parts of 42.5R silicate cement, 40 parts of S95 grade mineral powder, 8 parts of sodium-based bentonite, 15 parts of grade II zeolite powder, 8 parts of 250-mesh calcined metakaolin powder, and 4 parts of activator (sodium sulfate), totaling 100 parts.

[0086] The preparation method is the same as in Example 1.

[0087] Comparative Example 1

[0088] The present comparative example provides a cementitious material for curing high water content silt soft soil, the components of which are as follows in parts by weight:

[0089] 42.5R Portland cement 42 parts, S95 grade mineral powder 30 parts, sodium bentonite 8 parts, grade II zeolite powder 15 parts, and 250 mesh calcined metakaolin powder 5 parts, totaling 100 parts.

[0090] Comparative Example 2

[0091] The present comparative example provides a cementitious material, the components of which are as follows in parts by weight: 42.5R Portland cement 100 parts.

[0092] Performance Test

[0093] The cementitious materials in Examples 1-5 and Comparative Examples 1-2 were stirred and tested for relevant performance according to the method specified in “Soft Soil Curing Agent” (CJ / T 526-2018), and the permeability coefficient of the cured silt soil was tested according to the method specified in “Standard for Soil Test Methods” (GB / T 50123-2019). The high water content silt soft soil sample was silt soil drilled at a depth of 5-10 m in a project in Foshan, with a water content of 65%, an organic matter content of 7.1%, and a water-binder ratio of 0.7 to obtain a neat paste. The cementitious material dosage was 15% of the mass of the silt soil when forming the cured silt soil test block.

[0094] The specific results are shown in Table 1 below.

[0095] Table 1 Performance Test Results of Examples and Comparative Examples

[0096]

[0097]

[0098] Analyzing the experimental data in Table 1, it can be seen that the addition of the activator plays a crucial role in improving the fluidity of the cementitious material paste, the unconfined compressive strength of the cured silt soil, and the impermeability. Comparing Examples 1-5 with Comparative Example 2, it can be seen that the cementitious material for curing high water content silt soft soil provided by the present application has excellent fluidity of the neat paste and greatly superior curing effect on the cured soil compared to traditional cement curing effect due to the synergistic effect of the specific components and proportions.

[0099] Further, comparing Example 1 with Example 2, it can be seen that the selection of (D10+D50) / D90 = 1.0-1.6 and D90 / specific surface area = (2.6-3.5) (nm / m 2 ·g -1The zeolite powder and the montmorillonite compound with chemical components meeting the formula defined relationship are beneficial to improve the fluidity of the cementing material slurry and the unconfined compressive strength and impermeability of the solidified silt; it can be known from the comparative example 2 and the examples 3 and 4 that changing the parameters of the zeolite powder or increasing the content of the montmorillonite in the bentonite can slightly reduce the fluidity of the cementing material slurry, shorten the setting time, but reduce the unconfined compressive strength and impermeability of the solidified silt; it can be known from the comparative example 1 and the example 5 that simultaneously increasing the dosages of the mineral powder, the metakaolin and the activator can greatly improve the fluidity of the cementing material slurry and the unconfined compressive strength and impermeability of the solidified silt.

[0100] It can be seen from the test results in the table that the cementing material for solidifying the silt soft soil with high water content in the embodiment has good neat slurry fluidity, is convenient for construction, has excellent silt soft soil strength and impermeability, and can be applied to solidifying the silt soft soil with high water content and high organic matter content.

[0101] The above only discloses a preferred embodiment of the present application, and of course cannot limit the scope of the present application, so equivalent changes made according to the claims of the present application are still within the scope of the present application.

Claims

1. A cementitious material for curing soft soil of high water content sludge, characterized by, The cementitious material comprises, in percentage by weight, 15-40% of Portland cement, 20-45% of mineral powder, 5-20% of bentonite, 10-30% of zeolite powder, 2-10% of metakaolin and 0.5-6% of activator; The high-water-content silt soft soil has a water content of 60-150% and an organic matter content of 5-10%. The zeolite powder has a fineness of 80 μm square mesh sieve residue less than or equal to 10%, an ammonium adsorption value greater than or equal to 100 mmol / 100g, and a 28-day compressive strength ratio of zeolite powder cement mortar greater than or equal to 70%. The pore size of the zeolite powder satisfies the following relationship: (D10+D50) / D90=1.0-1.6; D90 / S=2.6-3.5; wherein D10 is the corresponding pore size when the cumulative distribution of the zeolite powder is 10%, D50 is the corresponding pore size when the cumulative distribution of the zeolite powder is 50%, and D90 is the corresponding pore size when the cumulative distribution of the zeolite powder is 90%, and the unit is nm; S is the specific surface area in m2 / g 2 / g.

2. The cementitious material for the solidification of soft soil with high water content according to claim 1, wherein, The activator is sodium sulfate.

3. The cementitious material for the solidification of soft soil with high water content according to claim 1, wherein The chemical composition of the bentonite satisfies the following relationship: wherein k1 is a constant with a value range of 1.05-1.1, and k2 is a constant with a value range of 1.3-1.5; n(Na + ) is the molar content of exchangeable Na + in the bentonite; n(Ca 2+ ) is the molar content of exchangeable Ca 2+ in the bentonite; w(Na2O) is the mass fraction of Na2O measured in the bentonite; w(K2O) is the mass fraction of K2O measured in the bentonite; w(CaO) is the mass fraction of CaO measured in the bentonite; w(MgO) is the mass fraction of MgO measured in the bentonite; The bentonite has a fineness of 200-600 mesh.

4. The cementitious material for the solidification of soft soil with high water content according to claim 3, wherein The weight ratio of the zeolite powder to the bentonite is 1:(0.3-0.7).

5. The cementitious material for the solidification of soft soil with high water content according to claim 1, wherein The metakaolin is calcined metakaolin, and the metakaolin has a fineness of 200-500 mesh; The activity index of the mineral powder is above 95% at 28 days; The strength grade of the Portland cement is not less than 42.

5.

6. A method for preparing the cementing material for curing soft soil with high water content according to any one of claims 1 to 5, characterized by the steps of It comprises: (1) Portland cement, mineral powder, bentonite, zeolite powder, metakaolin and activator are weighed by weight parts for use; (2) the Portland cement, mineral powder, bentonite, zeolite powder, metakaolin and activator are mixed uniformly to obtain the cementitious material.

7. The cementitious material for high-water-content silt soft soil curing according to any one of claims 1-5 or prepared by the preparation method of claim 6 is applied in high-water-content silt soft soil curing, and the use method is as follows: The cementitious material is mixed with water to form a cementitious material slurry, and then is uniformly stirred with the high-water-content silt soft soil, and the mixing ratio of the cementitious material to water in the cementitious material slurry is 1:(0.6-0.8).

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