Foamed slurry with volume expansion and contraction properties and method of preparation

Abstract

The present application relates to the technical field of building materials, and particularly relates to a foamed slurry with volume expansion and shrinkage characteristics and a preparation method thereof.The foamed slurry comprises the following components in a weight ratio: 1000 parts of dry slag; 200-300 parts of a curing agent; 650-750 parts of water; 1-3 parts of a foaming agent; 1-2 parts of an anti-dispersant; and 2-4 parts of a stabilizer.The foamed slurry with volume expansion and shrinkage characteristics is stable in volume after curing, and can be subjected to volume compression transportation, filling and other operations in the uncured stage due to the presence of internal closed-cell flexible bubbles, and is suitable for engineering scenarios such as ground reinforcement, tunnel support, anti-seismic structure, cavity filling and underground plugging.

Description

Technical Field

[0001] This invention relates to the field of building materials technology, and in particular to a foamed slurry with volume expansion and contraction characteristics and its preparation method. Background Technology

[0002] In traditional engineering construction, commonly used materials such as cement grout, polymer grout, and foamed concrete are mainly used for filling, reinforcement, and sealing. However, existing materials have the following limitations:

[0003] (1) Cement grout:

[0004] After cement grout solidifies, it forms a rigid structure that cannot provide flexible resilience and its volume changes irreversibly, making it difficult to adapt to dynamic load environments.

[0005] In application scenarios, cement grout is mainly used for permanent filling and support, but it lacks the buffering effect against instantaneous loads or impacts.

[0006] (2) Chemical grouting materials (such as polyurethane grouting):

[0007] Chemical grouting materials cure quickly, can fill gaps and provide a certain strength, but the cured structure is brittle and lacks durability and impact resistance.

[0008] These materials typically expand or solidify irreversibly, and once formed, they cannot achieve prestress control or rebound. Their main applications are in compressed volume transportation and filling scenarios.

[0009] (3) Foamed concrete:

[0010] Foamed concrete reduces material density by introducing air bubbles, providing some heat insulation and filling effects, but its mechanical properties are limited. After curing, the air bubbles cannot be controlled and cannot form outward rebound force.

[0011] Under high load conditions, foamed concrete is prone to permanent deformation or cracking, making it difficult to achieve the effect of dynamic prestressing.

[0012] The existing materials have the following problems:

[0013] (1) Insufficient rigidity, making it difficult to generate prestress: Traditional materials are rigid structures after curing, which cannot form outward rebound force and are difficult to resist external loads.

[0014] (2) Poor energy absorption performance: Under the action of earthquake or impact load, traditional materials are difficult to effectively absorb energy, which can easily lead to structural damage.

[0015] (3) Irreversible volume change: Existing foam materials undergo irreversible volume change after pressurization or curing, and cannot adapt to the pressure requirements in dynamic environments.

[0016] In summary, existing materials have significant shortcomings in terms of flexibility, resilience, dynamic prestressing effect, and volume stability, making them unsuitable for complex dynamic environments and high-load conditions. Therefore, there is an urgent need for an engineering material with prestressing characteristics, volume stability after curing, and superior energy absorption performance to fill the gaps in existing technologies and meet the practical needs of engineering reinforcement and support. Summary of the Invention

[0017] This invention provides a foamed mud with volume expansion and contraction characteristics and a preparation method thereof, aiming to solve the problems existing in commonly used materials such as cement grout, polymer grout and foamed concrete in engineering construction.

[0018] This invention provides a foamed mud with volume expansion and contraction characteristics, comprising the following components in the indicated weight proportions:

[0019] 1000 parts dry slag; 200-300 parts curing agent; 650-750 parts water; 1-3 parts foaming agent; 1-2 parts anti-dispersing agent; 2-4 parts stabilizer.

[0020] As a further improvement of the present invention, the curing agent is a geopolymer-based curing agent, comprising: 50-60 parts of mineral powder, 30-40 parts of cement, and 10-20 parts of water glass.

[0021] As a further improvement of the present invention, the selection of the foaming agent components includes: for high-pressure environments, fluorocarbon-based foaming agents are selected; for humid and water-permeable environments, silane-modified foaming agents are selected.

[0022] As a further improvement of the present invention, the foam mud with volume expansion and contraction characteristics also includes a component by weight: 1-2 parts of waterproofing agent, wherein the waterproofing agent is selected from components including silane impregnating agent.

[0023] As a further improvement of the present invention, the anti-dispersant is selected from polyvinyl alcohol or sodium carboxymethyl cellulose; the stabilizer is selected from guar gum or nano silica sol.

[0024] As a further improvement of the present invention, the foam slurry with volume expansion and contraction characteristics also includes the following component ratio by weight: 5-8 parts of expansion agent; 3-5 parts of reinforcing agent; 0.5-1.5 parts of crack-resistant reinforcing material; and one or more of the expansion agent, reinforcing agent, and crack-resistant reinforcing material are selected for addition.

[0025] As a further improvement of the present invention, the expanding agent is selected from expanding microspheres or polyacrylamide; the reinforcing agent is selected from nano-silica or quartz powder; and the crack-resistant reinforcing material is selected from polypropylene fiber.

[0026] This invention also provides a method for preparing foamed mud with volume expansion and contraction characteristics, comprising the following steps:

[0027] S1. Preparation of materials for each component of foam mud:

[0028] S10. Sift the dry slag to ensure uniform particle size;

[0029] S11. Mix 50-60 parts of mineral powder, 30-40 parts of cement and 10-20 parts of water glass evenly to prepare a geopolymer-based curing agent for later use;

[0030] S12. Use clean, impurity-free water for later use;

[0031] S13. Select foaming agent according to application scenario: For high pressure environment, use fluorocarbon-based foaming agent; for humid and water-permeable environment, use silane-modified foaming agent.

[0032] S14. Polyvinyl alcohol or sodium carboxymethyl cellulose is selected as the anti-dispersant;

[0033] S15. Guar gum or nano silica sol shall be selected as stabilizers;

[0034] S2. Mixing of all components of foam slurry:

[0035] S21. Add 1000 parts of dry slag and 200-300 parts of geopolymer-based solidifier to the mixing device, and stir at low speed for 1-2 minutes to ensure uniform dispersion;

[0036] S22. Slowly add 650-750 parts of water to the mixing device while increasing the mixing speed to gradually form the slurry;

[0037] S23. Add 1-3 parts foaming agent, 1-2 parts anti-dispersant agent, and 2-4 parts stabilizer to the mixing device in sequence, and continue stirring for 3-5 minutes to form a uniform foam system.

[0038] As a further improvement of the present invention, step S1 further includes the following steps:

[0039] S16. Select one or more of the following additives: waterproofing agent, expanding agent, reinforcing agent, and crack-resistant reinforcing material, depending on the application scenario; among them, silane impregnating agent is selected as waterproofing agent; expandable microspheres or polyacrylamide are selected as expanding agent; nano silica or quartz powder is selected as reinforcing agent; and polypropylene fiber is selected as crack-resistant reinforcing material.

[0040] Step S2 further includes the following steps:

[0041] S24. Add 5-8 parts of expansion agent and 3-5 parts of reinforcing agent to the mixing device, and continue mixing for 5 minutes to ensure that the expansion agent and reinforcing agent are evenly distributed;

[0042] S25. Add 1-2 parts of waterproofing agent and 0.5-1.5 parts of crack-resistant reinforcing material to the mixing device, mix at low speed for 2 minutes to complete the preparation of foam mud.

[0043] As a further improvement of the present invention, after the preparation of the foamed mud is completed, the following step is also included:

[0044] S3. Foam Slurry Detection:

[0045] S31. Use a wet density meter to test the wet density of the foamed mud to ensure that the foamed mud meets the set wet density requirements;

[0046] S32. Conduct fluidity and expansion rate tests, and adjust the slurry state to the optimal working conditions;

[0047] S4. Pressure application: Inject foam mud into the target area using a high-pressure pump, while applying a predetermined pressure to cause the closed-cell bubbles to form a rebound force;

[0048] S5. Curing and solidification: Curing is carried out under a predetermined pressure, maintaining the moisture of the foam slurry until the volume of the foam slurry stabilizes after solidification.

[0049] The beneficial effects of this invention are: the foam mud with volume expansion and contraction characteristics has a stable volume after solidification, and due to the presence of internal closed-cell tough air bubbles, it can be transported and injected in volume compression during the unsolidified stage, making it suitable for engineering scenarios such as foundation reinforcement, tunnel support, seismic structures, cavity filling and well sealing. Attached Figure Description

[0050] Figure 1 These are diagrams showing the solidified foam mud product with volume expansion and contraction characteristics of the present invention before pressurization, during pressurization, and after depressurization.

[0051] Figure 2 This is a bar graph showing the volume, compressibility, and pressure of the solidified foam mud product with volume expansion and contraction characteristics before, during, and after pressurization. Detailed Implementation

[0052] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments.

[0053] A foamed mud with volume expansion and contraction characteristics according to the present invention comprises the following components in the indicated weight ratios:

[0054] 1000 parts dry slag; 200-300 parts curing agent; 650-750 parts water; 1-3 parts foaming agent; 1-2 parts anti-dispersion agent; 2-4 parts stabilizer; 5-8 parts expansion agent; 3-5 parts reinforcing agent; 1-2 parts waterproofing agent; 0.5-1.5 parts crack-resistant reinforcing material.

[0055] Dry slag, solidifying agent, water, foaming agent, anti-dispersing agent, and stabilizer are the main materials of foam slurry with volume expansion and contraction characteristics, while expanding agent, reinforcing agent, waterproofing agent, and crack-resistant reinforcing material are additional materials that can be selected individually or in combination depending on the application scenario.

[0056] The curing agent is a geopolymer-based curing agent, comprising: 50-60 parts mineral powder, 30-40 parts cement, and 10-20 parts water glass.

[0057] The selection of foaming agent components includes: for high-pressure environments, fluorocarbon-based foaming agents are selected, suitable for high-pressure conditions and complex load environments, possessing high stability and high-temperature resistance; for humid and seeping environments, silane-modified foaming agents are selected, suitable for environments with high humidity or strong groundwater permeability, providing excellent water resistance and durability.

[0058] The selection of waterproofing agents includes silane impregnating agents. Waterproofing agents are optional additives, added selectively depending on the environment in which the foam slurry will be used. For example, in humid and seeping environments, waterproofing agents can be added to improve the waterproofing properties of the foam slurry. The small molecular structure of silane impregnating agents allows them to deeply penetrate the substrate to form a durable waterproof layer with a long service life; the material is also highly durable and environmentally friendly.

[0059] Polyvinyl alcohol (PVA) or sodium carboxymethyl cellulose (CMC) are selected as anti-dispersants. PVA dissolves rapidly in water and forms a uniform protective film, effectively encapsulating particles, reducing dispersion, and exhibiting good adhesion and temperature stability. CMC has strong hydrophilicity and thickening properties, significantly increasing system viscosity, inhibiting particle sedimentation and segregation, and performing particularly well under alkaline conditions. Both are environmentally friendly and biodegradable, and are compatible with other additives, synergistically enhancing the anti-dispersant effect.

[0060] Stabilizers selected include guar gum or nano-silica sol. Guar gum possesses excellent thickening and suspending abilities, effectively preventing particle sedimentation or phase separation by forming a three-dimensional network structure. It also exhibits high biocompatibility, biodegradability, and low cost. Nano-silica sol, on the other hand, significantly enhances system stability through the high specific surface area and surface activity of its nano-sized silica particles, while simultaneously imparting enhanced mechanical strength, high-temperature resistance, and transparency to the material.

[0061] Expanding agents such as expandable microspheres (e.g., Expansionl) or polyacrylamide (PAM) are used: by introducing air bubbles or expandable microspheres into the material, the volume of the foamed mud is increased, allowing it to expand and rebound during pressurization or solidification, thus enhancing the material's elasticity and stability. Expanding agents are used in applications requiring volume expansion, such as foundation reinforcement, cavity filling, or downhole sealing.

[0062] The reinforcing agent is selected from nano-silica (SiO2) or quartz powder: it improves the mechanical properties of foamed mud, enhances the strength and wear resistance of the material, and gives it better load-bearing capacity under high pressure. The reinforcing agent is used in scenarios requiring high-strength support, such as tunnel support and structural reinforcement.

[0063] The crack-resistant reinforcement material uses polypropylene fibers: by adding fiber material to the slurry, stress is effectively dispersed, reducing cracks caused by external forces after curing. This crack-resistant reinforcement material is used in scenarios requiring prevention of crack propagation, such as seismic structures and earthquake strengthening projects.

[0064] This invention also provides a method for preparing foamed mud with volume expansion and contraction characteristics, characterized by comprising the following steps:

[0065] S1. Preparation of materials for each component of foam mud:

[0066] S10. Sift the dry slag to ensure uniform particle size;

[0067] S11. According to the geopolymer-based formula, 50-60 parts of mineral powder, 30-40 parts of cement and 10-20 parts of water glass are mixed evenly to prepare a geopolymer-based curing agent for later use.

[0068] S12. Use clean, impurity-free water for later use;

[0069] S13. Select the appropriate foaming agent according to the application scenario: For high-pressure environments, use fluorocarbon-based foaming agents; for humid and water-permeable environments, use silane-modified foaming agents.

[0070] S14. Polyvinyl alcohol (PVA) or sodium carboxymethyl cellulose (CMC) are selected as anti-dispersants;

[0071] S15. Guar gum or nano silica sol shall be selected as stabilizers;

[0072] S16. Select one or more of the following additives as the application scenario: waterproofing agent, expanding agent, reinforcing agent, and crack-resistant reinforcing material; among them, silane impregnating agent is selected as waterproofing agent; expandable microspheres (such as Expansionl) or polyacrylamide (PAM) are selected as expanding agent; nano silica (SiO2) or quartz powder is selected as reinforcing agent; and polypropylene fiber is selected as crack-resistant reinforcing material.

[0073] S2. Mixing of all components of foam slurry:

[0074] S21. Add 1000 parts of dry slag and 200-300 parts of geopolymer-based solidifier to the mixing device, and stir at low speed for 1-2 minutes to ensure uniform dispersion;

[0075] S22. Slowly add 650-750 parts of water to the mixing device while increasing the mixing speed to ensure that the slurry gradually takes shape;

[0076] S23. Add 1-3 parts of foaming agent (fluorocarbon-based foaming agent or silane-modified foaming agent depending on the application scenario), 1-2 parts of anti-dispersant agent, and 2-4 parts of stabilizer to the mixing device in sequence, and continue to stir for 3-5 minutes to form a uniform foam system;

[0077] S24. Add 5-8 parts of expansion agent (optional) and 3-5 parts of reinforcing agent (optional) to the mixing device, and continue mixing for 5 minutes to ensure that the expansion agent and reinforcing agent are evenly distributed;

[0078] S25. Finally, add 1-2 parts of waterproofing agent (optional) and 0.5-1.5 parts of crack-resistant reinforcing material (optional) to the mixing device, mix at low speed for 2 minutes to complete the preparation of foam mud.

[0079] The order of addition and the stirring intensity determine the uniformity of the distribution of each component in the slurry. Adding dry powder materials (such as dry slag and hardener) first, with low-speed stirring, helps disperse the base. Then, slowly add water and increase the stirring speed to ensure a well-flowing slurry.

[0080] Adding foaming agents, anti-dispersants, and stabilizers after the basic slurry is formed can ensure that the slurry forms a stable foam system under dynamic stirring, while avoiding premature reaction or clumping between components.

[0081] Foaming agents need to be added to a well-dispersed slurry system to form uniform bubbles and provide a density-reducing effect.

[0082] The order and timing of adding anti-dispersants and stabilizers (usually after the foaming agent) help maintain the rheological properties of the slurry and the stability of the foam, preventing bubbles from breaking or collapsing during stirring.

[0083] Expanding agents and reinforcing agents are typically added after the foam system has formed, and extending the stirring time allows for full utilization of their expansion and reinforcing effects. This process also directly affects the compressive strength of the slurry and its resilience after curing.

[0084] Waterproofing agents and crack-resistant reinforcing materials are typically added in the final stage to prevent excessive shearing or damage during vigorous mixing. These components directly affect the durability and crack resistance of the material after curing.

[0085] After the foam mud preparation is completed, the following steps are also included:

[0086] S3. Foam Slurry Detection:

[0087] S31. Use a wet density meter to test the wet density of the foamed mud to ensure that the foamed mud meets the set wet density requirements; the design requirement for wet density is generally 0.5~1.3 g / cm³. 3 This ensures the uniformity and stability of the material. If the wet density measurement does not meet the requirements, the relative proportions of the foaming agent, hardener, and water can be adjusted within the set range to bring the wet density within the required range. Wet density directly affects the fluidity of the slurry during subsequent construction and its mechanical properties after curing.

[0088] S32. Conduct fluidity and expansion rate tests, and adjust the slurry state to the optimal working conditions.

[0089] The fluidity test primarily ensures that the grout flows smoothly during construction, avoiding uneven grouting due to excessive viscosity or insufficient fluidity. The flow time is measured using a standard funnel, with 35-45 seconds considered the optimal fluidity. The expansion rate test ensures that the material provides the expected expansion effect in a dynamic environment, meeting the requirements of the application scenario (such as crack resistance or resilience). It is generally 5%-10%, with this range representing the optimal expansion rate.

[0090] The process of adjusting the slurry to optimal working conditions mainly includes: adjusting the ratio of water to curing agent to change the viscosity or flowability of the slurry; adjusting the amount of foaming agent as needed to ensure that the density and resilience of the slurry meet the standards; and correcting performance by appropriately increasing or decreasing the amount of components when deviations from target values ​​are found during testing. The ultimate goal of these operations is to ensure that the slurry, after curing, possesses the volumetric expansion and contraction characteristics and other physical properties required by the design, such as compressive strength and volume stability.

[0091] After preparing the foamed mud according to the component proportions, the following steps are also included:

[0092] S4. Pressure application: Inject the foam mud into the target area using a high-pressure pump, and apply a predetermined pressure to make the closed-cell bubbles form a rebound force. After the pressure is applied, the foam mud will generate a rebound force. The pressure needs to be adjusted according to the engineering requirements, but should not exceed 500 kPa to avoid overpressure causing bubble rupture or excessive compression.

[0093] S5. Curing and Maintenance: Curing is carried out under a predetermined pressure, maintaining the moisture of the foam slurry until its volume stabilizes after curing. The curing environment needs to maintain appropriate humidity (generally controlled at 80%-90%). Humidity can be maintained by covering with a damp cloth, spraying water, or using a wet curing membrane. Avoid excessive volume shrinkage during curing due to rapid water evaporation, which can lead to cracks or performance degradation. The temperature of the curing area is generally controlled between 10-30℃ to avoid excessively high or low temperatures affecting the chemical reaction and curing speed of the material. The curing time varies depending on the actual environment and material ratio, typically ranging from 6-48 hours. After curing, the externally applied pressure is gradually released to avoid sudden pressure release that could damage the internal structure of the slurry. Ensure a rebound rate of over 95% to confirm that the slurry's volume is basically stable after curing. The closed-cell air bubbles inside the cured product generate outward rebound force, providing a stable prestressing effect.

[0094] This foamed mud has the following characteristics: before curing, pressure is applied to cause the closed-cell air bubbles inside the mud to form an initial rebound force, and the volume can be restored after the pressure is released; when the set force is reached, the volume no longer shrinks, and the volume is stable after curing; after the mud is cured, the closed-cell air bubbles generate an outward rebound force, providing an effect similar to prestressed concrete.

[0095] like Figure 1 As shown, the compression test data of the solidified foam mud of the present invention are as follows: before pressurization: volume is 150ml; during pressurization (maximum pressure 500kPa): volume shrinks to 100ml; after depressurization: volume recovers to 148ml, with a rebound rate of 98.7%.

[0096] Pressure-volume curve analysis: such as Figure 2 As shown, with increasing pressure, the volume of the finished foamed mud gradually decreases, and after reaching the maximum compression, the volume tends to stabilize. After depressurization, the foamed mud exhibits good resilience and can recover to a state close to its initial volume.

[0097] Data comparison: The rebound rate of traditional foamed concrete is 80%; the rebound rate of the foamed slurry of this invention is 98.7%.

[0098] Strength test after curing: The compressive strength of the foamed mud of the present invention reached 5.8 MPa after curing for 28 days, which far exceeded the 3.2 MPa of ordinary foamed concrete.

[0099] The following two examples illustrate the preparation process of the foamed mud of the present invention under high pressure and humid environments, respectively.

[0100] Example 1: Foundation prestressing reinforcement (high pressure environment).

[0101] a1. Material selection and proportioning:

[0102] Dry slag soil: 1000 parts, selected from dry slag soil with uniform particle size and free of organic impurities.

[0103] Geopolymer-based curing agent: Mineral powder: 60 parts, providing basic strength support. Cement: 40 parts, enhancing the hardness and stability of the material. Water glass: 20 parts, acting as an initiator for the geopolymer reaction.

[0104] Water: 700 parts, to ensure the slurry has good fluidity.

[0105] Foaming agent: Select 2 parts of fluorocarbon-based foaming agent, which has high stability and is suitable for high-pressure foundation reinforcement environments.

[0106] Expanding agent: 6 parts, polyacrylamide (PAM) is selected to provide a certain degree of expansion.

[0107] Anti-dispersant: 1.5 parts, polyvinyl alcohol (PVA) is selected.

[0108] Reinforcing agent: 4 parts, selected from nano-silica (SiO2).

[0109] Stabilizer: 2 parts, guar gum is preferred.

[0110] Crack-resistant reinforcing material: 1 part, made of polypropylene fiber.

[0111] a2. Production process:

[0112] a21. Material mixing:

[0113] First, add the dry slag and geopolymer-based solidifier to the mixing equipment and mix at low speed for 2 minutes;

[0114] Add water slowly while gradually increasing the stirring speed to form a uniformly flowing slurry;

[0115] Add the foaming agent, expansion agent and reinforcing agent in sequence, and stir continuously for 5 minutes;

[0116] Finally, add the anti-dispersant and anti-cracking reinforcement materials, stir at low speed for 2 minutes, and the slurry preparation is complete.

[0117] a22. Slurry testing:

[0118] Wet density test: Measure the slurry density using a wet density meter, and control it within 1.2-1.3 g / cm³. 3 ;

[0119] Flowability test: Use a standard funnel to test the flow time, ensuring it is within 35-45 seconds.

[0120] a3. Construction process:

[0121] a31. On-site investigation: Conduct geological investigation of the foundation to determine the grouting location and depth.

[0122] a32. Grouting equipment preparation: High-pressure grouting equipment is used to inject foam slurry into the target area at a design pressure of 500 kPa.

[0123] a33. Pressure application: Initial pressure is applied by forming closed-cell bubbles through continuous high-pressure pumping.

[0124] a34. Curing and maintenance: After grouting is completed, maintain pressure for 24 hours until the grout cures; after curing, closed-cell air bubbles provide resilience and form a prestressed support layer.

[0125] a4. Effect detection:

[0126] a41. Prestressing effect: Pressure distribution inside the support layer is measured using pressure sensors. The pressure distribution within the support layer is uniform, with the maximum pressure concentrated in the central area, ensuring balanced load transfer and effective stress distribution.

[0127] a42. Rebound performance test: Using pressure-volume curve analysis, the rebound rate reaches over 98%.

[0128] a43. Foundation strength test: The compressive strength of the solidified support layer is 5.8 MPa.

[0129] Example 2: Downhole plugging (humid environment).

[0130] b1. Material selection and proportioning:

[0131] Dry slag: 1000 parts.

[0132] Geopolymer-based curing agent: Mineral powder: 50 parts. Cement: 35 parts. Water glass: 15 parts.

[0133] Water: 750 portions.

[0134] Foaming agent: Use 2 parts of silane-modified foaming agent, which is suitable for environments with high humidity and water penetration.

[0135] Expanding agent: 8 parts polyacrylamide.

[0136] Reinforcing agent: 5 parts nano-silica.

[0137] Stabilizer: 2 parts guar gum.

[0138] Anti-dispersant: 1 part polyvinyl alcohol.

[0139] b2. Production process:

[0140] b21. Material mixing:

[0141] First, add the dry slag and geopolymer-based solidifier to the mixing equipment and mix at low speed for 2 minutes;

[0142] Add water slowly while gradually increasing the stirring speed to form a uniformly flowing slurry;

[0143] Add the foaming agent, expansion agent and reinforcing agent in sequence, and stir continuously for 5 minutes;

[0144] Finally, add the anti-dispersant and anti-cracking reinforcement materials, stir at low speed for 2 minutes, and the slurry preparation is complete.

[0145] b22. Slurry testing:

[0146] Wet density test: Measure the slurry density using a wet density meter, and control it within 1.2-1.3 g / cm³. 3 ;

[0147] Flowability test: Use a standard funnel to test the flow time, ensuring it is within 35-45 seconds.

[0148] b3. Construction process:

[0149] b31. Investigation of the sealing area: Determine the location of downhole fractures and cavities.

[0150] b32. Foam grout injection: Inject grout into the target area using a low-pressure grouting pump.

[0151] b33. Pressure control and curing: Maintain pressure for 48 hours to ensure the slurry cures.

[0152] b4. Effect detection:

[0153] b41. Permeability: The permeability resistance coefficient of the cured material reaches 10. -8 cm / s.

[0154] b42. Stability: No obvious leakage or settlement occurs in the sealed area.

[0155] b43. Rebound rate test: The material rebound rate reaches over 95%.

[0156] The above description, in conjunction with specific preferred embodiments, provides a further detailed explanation of the present invention. It should not be construed that the specific implementation of the present invention is limited to these descriptions. For those skilled in the art, various simple deductions or substitutions can be made without departing from the concept of the present invention, and all such modifications and substitutions should be considered within the scope of protection of the present invention.

Claims

1. A foamed mud with volume expansion and contraction characteristics, characterized in that, Includes the following weight component proportions: 1000 portions of dry slag; 200-300 parts of curing agent; 650-750 parts water; 1-3 parts foaming agent; 1-2 parts anti-dispersant; Stabilizer 2-4 parts; The curing agent is a geopolymer-based curing agent, comprising: 50-60 parts mineral powder, 30-40 parts cement, and 10-20 parts water glass; The selection of foaming agent components includes: for high-pressure environments, fluorocarbon-based foaming agents are selected; for humid and water-permeable environments, silane-modified foaming agents are selected.

2. The foamed mud with volume expansion and contraction characteristics according to claim 1, characterized in that, It also includes components by weight: 1-2 parts of waterproofing agent, wherein the composition of the waterproofing agent includes silane impregnating agent.

3. The foamed mud with volume expansion and contraction characteristics according to claim 1, characterized in that, The anti-dispersant is selected from polyvinyl alcohol or sodium carboxymethyl cellulose; the stabilizer is selected from guar gum or nano silica sol.

4. The foamed mud with volume expansion and contraction characteristics according to claim 1, characterized in that, It also includes the following weight distribution ratios: 5-8 parts of expanding agent; 3-5 parts of reinforcing agent; 0.5-1.5 parts of crack-resistant reinforcing material; One or more of the following can be added: expansion agent, reinforcing agent, and crack-resistant reinforcing material.

5. The foamed mud with volume expansion and contraction characteristics according to claim 4, characterized in that, The expanding agent is selected from expanded microspheres or polyacrylamide; the reinforcing agent is selected from nano-silica or quartz powder; and the crack-resistant reinforcing material is selected from polypropylene fiber.

6. A method for preparing foamed mud with volume expansion and contraction characteristics, characterized in that, Includes the following steps: S1. Preparation of materials for each component of foam mud: S10. Sift the dry slag to ensure uniform particle size; S11. Mix 50-60 parts of mineral powder, 30-40 parts of cement and 10-20 parts of water glass evenly to prepare a geopolymer-based curing agent for later use; S12. Use clean, impurity-free water for later use; S13. Select foaming agent according to application scenario: For high pressure environment, use fluorocarbon-based foaming agent; for humid and water-permeable environment, use silane-modified foaming agent. S14. Polyvinyl alcohol or sodium carboxymethyl cellulose is selected as the anti-dispersant; S15. Guar gum or nano silica sol shall be selected as stabilizers; S2. Mixing of all components of foam slurry: S21. Add 1000 parts of dry slag and 200-300 parts of geopolymer-based solidifier to the mixing device, and stir at low speed for 1-2 minutes to ensure uniform dispersion; S22. Slowly add 650-750 parts of water to the mixing device while increasing the mixing speed to gradually form the slurry; S23. Add 1-3 parts foaming agent, 1-2 parts anti-dispersant agent, and 2-4 parts stabilizer to the mixing device in sequence, and continue stirring for 3-5 minutes to form a uniform foam system.

7. The method for preparing foamed mud with volume expansion and contraction characteristics according to claim 6, characterized in that, Step S1 further includes the following steps: S16. Select one or more of the following additives: waterproofing agent, expanding agent, reinforcing agent, and crack-resistant reinforcing material, depending on the application scenario; among them, silane impregnating agent is selected as waterproofing agent; expandable microspheres or polyacrylamide are selected as expanding agent; nano silica or quartz powder is selected as reinforcing agent; and polypropylene fiber is selected as crack-resistant reinforcing material. Step S2 further includes the following steps: S24. Add 5-8 parts of expansion agent and 3-5 parts of reinforcing agent to the mixing device, and continue mixing for 5 minutes to ensure that the expansion agent and reinforcing agent are evenly distributed; S25. Add 1-2 parts of waterproofing agent and 0.5-1.5 parts of crack-resistant reinforcing material to the mixing device, mix at low speed for 2 minutes to complete the preparation of foam mud.

8. The method for preparing foamed mud with volume expansion and contraction characteristics according to claim 6, characterized in that, After the foam mud preparation is completed, the following steps are also included: S3. Foam Slurry Detection: S31. Use a wet density meter to test the wet density of the foamed mud to ensure that the foamed mud meets the set wet density requirements; S32. Conduct fluidity and expansion rate tests, and adjust the slurry state to the optimal working conditions; S4. Pressure application: Inject foam mud into the target area using a high-pressure pump, while applying a predetermined pressure to cause the closed-cell bubbles to form a rebound force; S5. Curing and solidification: Curing is carried out under a predetermined pressure, maintaining the moisture of the foam slurry until the volume of the foam slurry stabilizes after solidification.

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