Preparation method of quick-hardening solidifying agent suitable for silt soft soil

Abstract

The application relates to the technical field of silt soft soil and discloses a preparation method of a quick-hardening solidifying agent suitable for silt soft soil, which comprises the following preparation steps: 1) configuring main materials, wherein the main materials comprise fly ash, gypsum, aluminate cement and mineral powder; configuring an activator, wherein the activator comprises quicklime, water glass and sodium hydroxide; the proportion of the main materials and the activator is (9.5-11):(0.8-1.2) according to the mass ratio; 2) placing the main materials and the activator in a stirrer to stir and mix, forming a mixture; placing the mixture and water in the stirrer to stir and mix, forming a solidifying agent; the proportion of the mixture and the water is (0.9-1.3):(0.8-1.2) according to the mass ratio. Through the action of the activator, the problem that the high organic matter content, the weak acidic soil and the low pH value of the silt soft soil in the coastal area affect the role of the solidifying agent in the activation process and cannot completely activate the activity of the mineral admixture is overcome.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of silt soft soil, in particular to a preparation method of a fast-hardening solidifying agent suitable for silt soft soil. BACKGROUND

[0002] Silt geology has the characteristics of high water content, large porosity, large deformation, low strength, and thixotropy, rheology, etc. Influenced by this geological environment, large machinery cannot proceed with the next step of construction because of its excessive self-weight when engineering construction is carried out in this area. Therefore, it is necessary to solidify the shallow surface silt soft soil foundation before construction.

[0003] In the prior art, the most commonly used method for reinforcing silt soft soil is to use ordinary Portland cement type solidifying agent to reinforce the silt in situ, which has the advantages of low cost, convenient material selection, and good stability of solidified silt soil, etc. However, its early strength is low, which affects the construction progress of the project. The main reasons are as follows: on the one hand, the ordinary Portland cement type solidifying agent is mixed into the soft soil and hydrates slowly, and the rate of generating calcium silicate hydrate gel and calcium hydroxide is slow, so the early strength of the solidified soil rises slowly; on the other hand, the existing solidifying agent will mix mineral admixtures such as mineral powder, fly ash, etc. into it, and a higher alkaline environment is needed to activate the activity of the mineral admixtures using an activator. However, the silt soft soil in coastal areas has a high content of organic matter, the soil quality is weakly acidic, and the pH value is low, which will reduce the pH value of the solidified soil, resulting in that the cement solidifying agent is affected during the activation process and cannot fully activate the activity of the mineral admixtures. The above reasons result in that the early hydration products in the solidified soil are generated slowly, the strength is low, and further the construction progress of the project is affected. SUMMARY

[0004] The purpose of the present application is to provide a preparation method of a fast-hardening solidifying agent suitable for silt soft soil, which aims to solve the problem of low early strength of the solidified soil formed by using a solidifying agent to reinforce the silt soft soil in coastal areas in situ in the prior art.

[0005] The present application is implemented as follows: a preparation method of a fast-hardening solidifying agent suitable for silt soft soil, comprising the following preparation steps:

[0006] 1) configuring a main material, the main material comprising fly ash, gypsum, aluminate cement and mineral powder; configuring an activator, the activator comprising quicklime, water glass and sodium hydroxide; according to the mass ratio, the ratio of the main material to the activator is (9.5-11):(0.8-1.2);

[0007] 2) placing the main material and the activator in a stirrer to stir and mix, forming a mixture, placing the mixture and water in the stirrer to stir and mix, forming a solidifying agent, according to the mass ratio, the ratio of the mixture to water is (0.9-1.3):(0.8-1.2).

[0008] Optionally, in the preparation step 1), according to the proportion of components, the main material comprises 30-50 parts of mineral powder, 20-30 parts of fly ash, 15-20 parts of aluminate cement and 15-20 parts of desulfurization gypsum.

[0009] Optionally, in the preparation step 1), the mineral powder is S95 mineral powder or S105 mineral powder, and the specific surface area of the mineral powder is greater than 450 kg / m 2 .

[0010] Optionally, in the preparation step 1), the fly ash is first-grade fly ash or superfine fly ash, and the specific surface area of the fly ash is greater than 400 kg / m 2 .

[0011] Optionally, in the preparation step 1), the aluminate cement has a label of CA50, the aluminate cement contains aluminum oxide, and the content of the aluminum oxide is not less than 50%.

[0012] Optionally, in the preparation step 1), the gypsum is desulfurization gypsum, and the fineness of the gypsum is not less than 270 mesh.

[0013] Optionally, in the preparation step 1), according to the proportion of components, the activator comprises 25-50 parts of quicklime, 25-50 parts of water glass and 25-50 parts of sodium hydroxide.

[0014] Optionally, in the preparation step 1), the quicklime contains calcium oxide, and the water glass contains sodium silicate.

[0015] Optionally, in the preparation step 2), the stirrer has a stirring cavity, a stirring shaft is arranged in the stirring cavity, a plurality of transversely arranged blades are arranged on the stirring shaft, and the plurality of blades are arranged in the axial direction and the circumferential direction of the stirring shaft.

[0016] A plurality of feeding ports are arranged at the top of the stirring cavity, the inside of the stirring shaft is in a hollow shape and forms a hollow cavity, the hollow cavity extends along the axial direction of the stirring shaft, the hollow cavity penetrates the outer periphery of the stirring shaft and forms a water outlet, the water outlet is formed with a one-way membrane sleeve, the one-way membrane sleeve has a one-way channel, the inner end of the one-way membrane sleeve is connected to the water outlet, and the outer end of the one-way membrane sleeve is arranged in a flexible manner.

[0017] The water outlet is provided with a limiting ring, which is arranged on the inner side of the water outlet along the extension direction of the hollow cavity, the one-way membrane sleeve is arranged on the outer side of the limiting ring, and the outer section of the limiting ring is fixedly connected to the side wall of the hollow cavity; when the water is sprayed into the stirring cavity through the water outlet, the one-way membrane sleeve deforms outward away from the water outlet, the one-way channel expands outward, and the water is sprayed into the stirring cavity through the one-way channel; when the water extrudes the one-way membrane sleeve from the stirring cavity, the limiting ring limits the deformation of the one-way membrane sleeve towards the hollow cavity.

[0018] In the preparation step 2), the stirring shaft rotates to stir, the main material and the activator are synchronously introduced into the stirring cavity through a plurality of feeding ports, respectively, and after stirring and mixing for a set time by the plurality of blades of the stirring shaft, the mixed material is formed.

[0019] During the rotation of the stirring shaft, water is injected into the hollow cavity, the water is sprayed into the stirring cavity through a plurality of water outlets and a one-way membrane sleeve, and the water is mixed with the mixed material to form the curing agent.

[0020] Optionally, the inner end of the blade is connected to the stirring shaft, the outer end of the blade extends away from the stirring shaft to form an outer section, the outer section is formed with a plurality of flexible pieces, the flexible pieces are arranged at intervals, and the adjacent flexible pieces have elastic intervals.

[0021] The elastic intervals are provided with elastic strips, and the elastic strips in the adjacent elastic intervals are arranged in a staggered manner along the length direction of the blade; in the preparation step 2), the stirring shaft rotates at variable speed, the plurality of flexible strips on the blade rotate synchronously with the stirring shaft, and the flexible strips reciprocate synchronously during rotation with the change of the rotating speed of the stirring shaft and the elastic expansion and contraction of the elastic strips.

[0022] Compared with the prior art, the fast-hardening curing agent preparation method suitable for silt soft soil provided by the application provides that the main component of the quicklime in the activator is calcium oxide, which reacts with water in the soil to generate an alkaline environment, providing necessary conditions for the hydration of the mineral powder.

[0023] The main component of the water glass in the activator is sodium silicate, which is combined with quicklime after being dissolved, and the generated sodium ions are combined with hydroxyl ions in calcium hydroxide to generate a strong alkaline environment in the environment, further enhancing the alkalinity of the solidified soil body, and the sodium silicate is combined with calcium ions to generate hydrated calcium silicate gel, which is a substance with gelation, which can effectively cement the soil particles, and enhance the strength and stability of the solidified soil body. Secondly, the hydrated calcium silicate gel fills the gaps between the soil particles, further improving the compactness and impermeability of the solidified soil body.

[0024] The sodium hydroxide in the activator enhances the pH value of the solidified soil, and enhances the alkali activation effect. In this way, the problem that the high organic matter content, the weak acidic soil, and the low pH value of the silt soft soil in the coastal area affect the role of the solidifying agent in the activation process and cannot fully activate the activity of the mineral admixture is overcome. BRIEF DESCRIPTION OF DRAWINGS

[0025] Figure 1 is a flowchart of the preparation method of the fast-hardening solidifying agent for silt soft soil provided by the present application;

[0026] Figure 2 is a partial schematic view of the stirring cavity provided by the present application;

[0027] Figure 3 is a schematic view of the connection of the plurality of flexible sheets provided by the present application;

[0028] Figure 4 is an enlarged schematic view of position A in Figure 2 . DETAILED DESCRIPTION

[0029] In order to make the purpose, technical solutions and advantages of the present application clearer, the present application is further described in detail below in combination with the drawings and examples. It should be understood that the specific examples described herein are only used to explain the present application, and are not used to limit the present application.

[0030] The implementation of the present application is described in detail below in combination with specific examples.

[0031] In the drawings of the present embodiment, the same or similar reference numerals correspond to the same or similar components; in the description of the present application, it should be understood that the orientations or positional relationships indicated by the terms "upper", "lower", "left", "right", etc. are based on the orientations or positional relationships shown in the drawings, and are only used to facilitate the description of the present application and simplify the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, therefore the terms describing the positional relationships in the drawings are used only for exemplary illustration, and cannot be understood as a limitation on the present patent, for those skilled in the art, the specific meanings of the above terms can be understood according to the specific circumstances.

[0032] Referring to Figures 1-4 , a preferred embodiment provided by the present application is shown.

[0033] The preparation method of the fast-hardening solidifying agent for silt soft soil provided by the present application comprises the following preparation steps:

[0034] 1), configuration of main material, main material includes fly ash, gypsum, aluminate cement and mineral powder; configuration of activator, activator includes quicklime, water glass and sodium hydroxide; according to the mass ratio, the ratio of main material and activator is (9.5-11):(0.8-1.2);

[0035] 2), the main material and the activator are placed in the stirrer 10 to stir and mix, forming a mixture, the mixture and water are placed in the stirrer 10 to stir and mix, forming a curing agent, according to the mass ratio, the ratio of the mixture and water is (0.9-1.3):(0.8-1.2).

[0036] The above provided preparation method of fast hardening curing agent suitable for silt soft soil is provided, the main component of quicklime in the activator is calcium oxide, which reacts with water in the soil to generate an alkaline environment, providing necessary conditions for the hydration of mineral powder.

[0037] The main component of water glass in the activator is sodium silicate, which is combined with quicklime after dissolution, and the sodium ions generated can combine with hydroxyl ions in calcium hydroxide to generate a strong alkaline environment in the environment, further enhancing the alkalinity of the cured soil, while the sodium silicate combines with calcium ions to generate hydrated calcium silicate gel, which is a substance with gelation, which can effectively cement the soil particles, enhance the strength and stability of the cured soil. Secondly, the hydrated calcium silicate gel fills the voids between the soil particles, further improving the density and impermeability of the cured soil.

[0038] The sodium hydroxide in the activator enhances the pH value of the cured soil and enhances the alkali activation effect. In this way, the problem that the silt soft soil in coastal areas has high organic matter content, the soil is weakly acidic, and the pH value is low, which affects the role of the curing agent in the activation process and cannot fully activate the activity of the mineral admixture is overcome.

[0039] The aluminate cement is CA50, wherein the content of aluminum oxide is not less than 50%, the 1d compressive strength is not less than 50MPa, and the 3d strength is not less than 60MPa; the gypsum is desulfurization gypsum, and the fineness is not less than 270 mesh.

[0040] The mineral powder is a molten material with calcium silicate as the main component obtained by the blast furnace smelting of the iron mill, which is water quenched into particles, dried, and ground to obtain high-activity high-quality mineral admixture. After alkali activation, the mineral powder can form hydrated calcium silicate and hydrated calcium aluminate, thereby playing a role in curing the soil.

[0041] Fly ash is fine ash discharged from the blast furnace flue gas of the coal-fired power plant. It contains a large amount of amorphous active silicon dioxide and active aluminum oxide, which can generate hydrated calcium silicate and hydrated calcium aluminate after alkali activation, which can cement soil particles and enhance the strength of the cured soil.

[0042] Aluminate cement, which mainly includes calcium aluminate, dicalcium aluminate, is a hydraulic cementitious material. When mixed with water, it hydrates to form calcium aluminate hydrate and aluminum hydroxide. At this time, the calcium aluminate hydrate further reacts with another component of the curing agent, gypsum, to form ettringite, which can greatly fill the voids between soil particles; aluminum hydroxide has cementitious properties and can cement soil particles.

[0043] Specifically, in the preparation step 1), according to the proportion of components, the main materials include 30-50 parts of mineral powder, 20-30 parts of fly ash, 15-20 parts of aluminate cement and 15-20 parts of desulfurization gypsum.

[0044] Specifically, in the preparation step 1), the mineral powder is S95 mineral powder or S105 mineral powder, and the specific surface area of the mineral powder is greater than 450 kg / m 2 .

[0045] Specifically, in the preparation step 1), the fly ash is first-grade fly ash or superfine fly ash, and the specific surface area of the fly ash is greater than 400 kg / m 2 .

[0046] Specifically, in the preparation step 1), the aluminate cement has a CA50 label, and the aluminate cement contains aluminum oxide, and the content of the aluminum oxide is not less than 50%. And the 1d compressive strength is not less than 50MPa, and the 3d strength is not less than 60MPa.

[0047] Specifically, in the preparation step 1), the gypsum is desulfurization gypsum, and the fineness of the gypsum is not less than 270 mesh.

[0048] Specifically, in the preparation step 1), according to the proportion of components, the activator includes 25-50 parts of quicklime, 25-50 parts of water glass and 25-50 parts of sodium hydroxide.

[0049] Specifically, in the preparation step 1), the quicklime contains calcium oxide, and the water glass contains sodium silicate.

[0050] In the preparation step 2), the stirrer 10 has a stirring cavity 11, a stirring shaft 100 in the stirring cavity 11, a plurality of transversely arranged blades on the stirring shaft 100, and a plurality of blades arranged along the axial direction and the circumferential direction of the stirring shaft 100;

[0051] The top of the stirring cavity 11 is provided with a plurality of feeding ports, the inside of the stirring shaft 100 is hollow, and a hollow cavity 101 is formed, which extends along the axial direction of the stirring shaft 100 and penetrates the outer periphery of the stirring shaft 100 to form a water outlet; the water outlet is formed with a one-way membrane sleeve 110, the one-way membrane sleeve 110 has a one-way channel 111, the inner end of the one-way membrane sleeve 110 is connected to the water outlet, and the outer end of the one-way membrane sleeve 110 is flexibly arranged;

[0052] A limiting ring 120 is fixed on the water outlet, and is arranged on the inner side of the water outlet along the extension direction of the hollow cavity 101. The one-way membrane sleeve 110 is arranged on the outer side of the limiting ring 120. The outer section of the limiting ring 120 is fixedly connected to the side wall of the hollow cavity 101. When the water is sprayed into the stirring cavity 11 through the water outlet, the one-way membrane sleeve 110 deforms outward away from the water outlet, the one-way channel 111 expands outward, and the water is sprayed into the stirring cavity 11 through the one-way channel 111. When the water extrudes the one-way membrane sleeve 110 from the stirring cavity 11, the limiting ring 120 limits the one-way membrane sleeve 110 from deforming towards the hollow cavity 101.

[0053] In the preparation step 2), the stirring shaft 100 rotates to stir. The main material and the activator are synchronously introduced into the stirring cavity 11 through the plurality of feeding ports. After being stirred and mixed by the plurality of blades of the stirring shaft 100 for a set time, the mixed material is formed.

[0054] In the process of rotating and stirring, the stirring shaft 100 injects water into the hollow cavity 101. The water is sprayed into the stirring cavity 11 through the plurality of water outlets and the one-way membrane sleeve 110. The water is stirred and mixed with the mixed material to form the curing agent. In this way, the main material and the activator are first stirred and mixed uniformly to form the mixed material. Then, water is sprayed into the stirring cavity 11 through the plurality of water outlets. The water sprayed from the plurality of water outlets is uniformly mixed with the mixed material to form the curing agent. The stirring is complete and the mixing is uniform. The water flows in one direction through the action of the one-way membrane sleeve 110 and the limiting ring 120.

[0055] The inner end of the blade is connected to the stirring shaft 100, and the outer end of the blade extends away from the stirring shaft 100 to form an outer section. The outer section has a plurality of flexible pieces 200. The plurality of flexible pieces 200 are arranged at intervals. The adjacent flexible pieces 200 have elastic intervals.

[0056] The elastic strip 210 is arranged in the elastic interval. Along the length direction of the blade, the elastic strips 210 in the adjacent elastic intervals are arranged in a staggered manner. In the preparation step 2), the stirring shaft 100 rotates at a variable speed. The plurality of flexible pieces 200 on the blade rotate synchronously with the stirring shaft 100. The plurality of flexible pieces 200 reciprocate synchronously in the process of rotating, along with the change of the rotating speed of the stirring shaft 100 and the elastic expansion and contraction of the elastic strip 210. In this way, through the connection relationship between the plurality of flexible pieces 200 and the elastic strip 210, the flexible piece 200 is subjected to resistance in the process of rotating the stirring shaft 100. The elastic strip 210 elastically contracts. Along with the change of the rotating speed, the resistance changes to make the elastic strip 210 deform repeatedly. The flexible piece 200 repeatedly swings to promote uniform stirring.

[0057] The above merely describes preferred embodiments of the present application, and is not used to limit the present application, any modification, equivalent replacement and improvement within the spirit and principle of the present application should be included in the protection scope of the present application.

Claims

1. A method for preparing a quick-hardening solidifying agent for soft silt soil, characterized by, The preparation method comprises the following steps: 1) configure the main material, the main material comprises fly ash, gypsum, aluminate cement and mineral powder; configure the activator, the activator comprises quicklime, water glass and sodium hydroxide; according to the mass ratio, the ratio of the main material and the activator is (9.5~11):(0.8~1.2); 2) the main material and the activator are placed in the stirrer for stirring and mixing to form a mixture, and the mixture and water are placed in the stirrer for stirring and mixing to form a curing agent, according to the mass ratio, the ratio of the mixture and water is (0.9~1.3):(0.8~1.2); in the preparation step 2), the stirrer has a stirring cavity, a stirring shaft is arranged in the stirring cavity, a plurality of transversely arranged blades are arranged on the stirring shaft, and the plurality of blades are arranged along the axial direction and the circumferential direction of the stirring shaft; a plurality of feeding ports are arranged on the top of the stirring cavity, the inside of the stirring shaft is hollow to form a hollow cavity, the hollow cavity extends along the axial direction of the stirring shaft, the hollow cavity penetrates through the outer periphery of the stirring shaft to form a water outlet, the water outlet is formed with a one-way membrane sleeve, the one-way membrane sleeve has a one-way channel, the inner end of the one-way membrane sleeve is connected to the water outlet, and the outer end of the one-way membrane sleeve is arranged in a flexible manner; a limiting ring is fixedly arranged on the water outlet, along the extension direction of the hollow cavity, the limiting ring is arranged on the inner side of the water outlet, the one-way membrane sleeve is arranged on the outer side of the limiting ring, and the outer section of the limiting ring is fixedly connected to the side wall of the hollow cavity; when the water is sprayed into the stirring cavity through the water outlet, the one-way membrane sleeve deforms outward away from the water outlet, the one-way channel expands outward, and the water is sprayed into the stirring cavity through the one-way channel; when the water extrudes the one-way membrane sleeve from the stirring cavity, the limiting ring limits the deformation of the one-way membrane sleeve towards the hollow cavity; in the preparation step 2), the stirring shaft rotates to stir, the main material and the activator are synchronously fed into the stirring cavity through the plurality of feeding ports, and the mixture is formed after the stirring and mixing of the main material and the activator by the plurality of blades of the stirring shaft for a certain time; during the rotation and stirring of the stirring shaft, water is injected into the hollow cavity, the water is sprayed into the stirring cavity through the plurality of water outlets and the one-way membrane sleeve, and the water is stirred and mixed with the mixture to form the curing agent; the inner end of the blade is connected to the stirring shaft, the outer end of the blade extends away from the stirring shaft to form an outer section, the outer section is formed with a plurality of flexible pieces, the plurality of flexible pieces are arranged in an elastic interval, and the adjacent flexible pieces are arranged in an elastic interval; elastic strips are arranged in the elastic interval, adjacent elastic strips in the elastic interval are arranged in a staggered manner along the length direction of the blade; in the preparation step 2), the stirring shaft rotates at variable speed, the plurality of flexible strips on the blade rotate synchronously with the stirring shaft, and the plurality of flexible strips reciprocate synchronously during the rotation of the stirring shaft.

2. The method for preparing a rapid hardening solidifying agent for soft silt according to claim 1, wherein In the preparation step 1), the main materials include 30-50 parts of mineral powder, 20-30 parts of fly ash, 15-20 parts of aluminate cement and 15-20 parts of desulfurization gypsum according to the proportion of components.

3. The method for preparing a rapid hardening solidifying agent for soft silt according to claim 1, wherein In the preparation step 1), the mineral powder is S95 mineral powder or S105 mineral powder, and the specific surface area of the mineral powder is greater than 450 kg / m 2 .

4. The method for preparing a rapid hardening solidifying agent for soft silt according to claim 1, wherein In the step 1) of the preparation, the fly ash is primary fly ash or ultra-fine fly ash, and the specific surface area of the fly ash is greater than 400 kg / m 2 .

5. The method for preparing a rapid hardening solidifying agent for soft sludge according to claim 1, wherein In the preparation step 1), the aluminate cement has a mark of CA50, contains alumina, and the content of the alumina is not less than 50%.

6. The method for preparing a rapid hardening solidifying agent for soft sludge according to claim 1, wherein In the preparation step 1), the gypsum is desulfurization gypsum, and the fineness of the gypsum is not less than 270 mesh.

7. The method for preparing a rapid hardening solidifying agent for soft sludge according to claim 1, wherein In the preparation step 1), the activator includes 25-50 parts of quicklime, 25-50 parts of water glass and 25-50 parts of sodium hydroxide according to the proportion of components.

8. The method for preparing a rapid hardening solidifying agent for soft sludge according to claim 1, wherein In the preparation step 1), the quicklime contains calcium oxide, and the water glass contains sodium silicate.

Images