Grouting plugging material for karst pipeline and preparation method of grouting plugging material

Abstract

The invention relates to a grouting plugging material for karst pipelines and a preparation method thereof, and relates to the technical field of grouting plugging materials, the grouting plugging material comprises a component A and a component B; the component A comprises the following raw materials in parts by weight: 90-100 parts of cement, 5-10 parts of an additive, 1-3 parts of a water reducing agent and 95-105 parts of water; the additive is obtained by sequentially calcining and ball-milling boron mud and green mud; the component B is prepared from the following raw materials in parts by weight: 20 to 30 parts of water glass, 0.5 to 2 parts of four-arm polyethylene glycol and 95 to 105 parts of water. The four-arm polyethylene glycol with proper molecular weight and the additive prepared from the boron mud and the green mud are mainly added, so that the mechanical property and the slurry retention rate of the obtained grouting plugging material are remarkably improved, the grouting plugging material can meet the plugging requirement of karst pipeline flowing water, secondary utilization of solid wastes is realized, and the grouting plugging material is green and environment-friendly.

Description

Technical Field

[0001] This invention relates to the field of grouting and sealing materials, and in particular to a grouting and sealing material for karst pipelines and its preparation method. Background Technology

[0002] Karst conduits, as unique geological structures formed during karst development, often contain dynamic water environments. These dynamic waters not only have large flows but also high velocities, posing a serious threat to the safety and stability of surrounding buildings, water conservancy projects, and transportation facilities. For example, in water conservancy construction, dynamic water in karst conduits may cause reservoir leakage, reducing the reservoir's water storage capacity and affecting its normal irrigation and power generation functions. In traffic tunnel construction, encountering dynamic water in karst conduits may trigger disasters such as water inrush and mudslides, creating construction safety hazards, delaying the construction period, and even causing tunnel structural damage.

[0003] Currently, grouting and sealing technology is one of the effective means to control the problem of flowing water in karst pipelines. By injecting specific sealing materials into the karst pipelines, they solidify and harden inside the pipeline, forming a strong barrier that stops the flow of water, thereby achieving the purpose of control. Therefore, the development of high-performance grouting and sealing materials is of great significance for ensuring the safe operation of various projects in karst areas.

[0004] However, existing grouting and sealing materials mainly have the following problems: 1. Currently, commonly used grouting and sealing materials on the market have certain limitations in terms of mechanical properties. Some traditional cement-based grouting materials, while possessing a certain strength, are prone to cracking and spalling when faced with the complex geological conditions and long-term erosion by flowing water in karst pipelines, leading to sealing failure. For example, in the treatment of karst pipelines in some water conservancy projects, after using ordinary cement grouting materials for sealing, significant damage appears on the surface of the grout after a period of water erosion, allowing flowing water to seep out again, failing to meet the requirements for long-term stable sealing.

[0005] 2. Grout retention rate is one of the important indicators for evaluating the performance of grouting and sealing materials. A low grout retention rate means that the grout injected into the karst pipeline is easily lost before solidification, failing to form a sufficiently thick seal at the target location, thus affecting the sealing effect. Some existing grouting materials, due to their fine particles and low viscosity, are easily carried away by flowing water, resulting in a low grout retention rate. For example, in the grouting construction of karst pipelines in traffic tunnels, after injection, most of the grout is lost with the flowing water, with only a small amount remaining in the pipeline, failing to achieve the expected sealing effect and increasing construction costs and difficulty. Summary of the Invention

[0006] To address the above problems, this invention provides a grouting and sealing material for karst pipelines and its preparation method.

[0007] In a first aspect, the present invention provides a grouting and sealing material for karst pipelines, the grouting and sealing material comprising component A and component B; By weight, component A comprises the following raw materials: 90-100 parts cement, 5-10 parts additives, 1-3 parts water-reducing agent and 95-105 parts water; The additive is obtained by calcining and ball milling boron mud and green mud in sequence. By weight, component B comprises the following raw materials: 20-30 parts water glass, 0.5-2 parts four-arm polyethylene glycol, and 95-105 parts water; The weight-average molecular weight of the four-armed polyethylene glycol is 10k~20k.

[0008] Furthermore, the volume ratio of component A to component B is (3~4):1.

[0009] Furthermore, the weight ratio of the boron mud to the green mud is (10~13):(3~5).

[0010] Furthermore, the working conditions for calcination include: calcination temperature of 450~550℃ and calcination time of 1~2 hours.

[0011] Furthermore, the working conditions parameters of the ball mill include: a ball-to-material ratio of (5~8):1, a ball milling medium of zirconia balls, and a ball milling time of 1~2 hours.

[0012] Further, by weight, component A comprises the following raw materials: 95 parts cement, 7 parts additives, 2 parts water-reducing agent and 100 parts water.

[0013] Further, by weight, component B comprises the following raw materials: 26.5 parts water glass, 1.5 parts four-arm polyethylene glycol and 100 parts water.

[0014] Furthermore, the cement includes silicate cement, and the water-reducing agent includes polycarboxylate-based water-reducing agents.

[0015] Furthermore, the modulus of the water glass is 2.0 to 2.5.

[0016] Secondly, based on the same inventive concept, the present invention provides a method for preparing the grouting and sealing material for karst pipelines as described in any of the first aspects, the method comprising the following steps: The raw materials in component A are mixed to obtain component A; The raw materials in component B are mixed to obtain component B; The A component and the B component are mixed to obtain the grouting and sealing material for karst pipelines.

[0017] The technical solutions provided in the embodiments of the present invention have at least the following advantages compared with the prior art: This invention provides a grouting and sealing material for karst pipelines and its preparation method. The invention primarily improves the mechanical properties and grout retention rate of the resulting grouting and sealing material by adding tetra-arm polyethylene glycol of suitable molecular weight and additives made from boron mud and green mud. This allows the material to meet the sealing requirements for flowing water in karst pipelines and also achieves the secondary utilization of solid waste, making it environmentally friendly. Specifically: 1. The functions of each raw material in component A are as follows: Cement: Cement is the main cementing material in grouting and sealing materials. When mixed with water, cement undergoes a hydration reaction, producing hydration products such as hydrated calcium silicate and hydrated calcium aluminate. These products intertwine to form a network structure, causing the material to gradually harden and acquire a certain strength.

[0018] Additives: The additives are obtained by sequentially calcining and ball milling boron mud and green mud. The calcination process alters the mineral structure of the boron mud and green mud, increasing their activity. Ball milling further refines the particles, increases the specific surface area, and enhances reactivity. The active ingredients in the additives can undergo secondary reactions with cement hydration products, generating more hydration products that fill the pores of the cement paste, improving the material's density and strength. Simultaneously, the additives can also regulate the cement hydration rate, improving the material's workability.

[0019] Water-reducing agents: The function of water-reducing agents is to reduce water consumption without altering the material's workability. They adsorb onto the surface of cement particles, causing the particles to carry the same electrical charge, thus repelling each other, dispersing them, and releasing the water trapped within the cement particles, thereby improving the fluidity of the paste. This not only reduces the water-cement ratio and improves the material's strength and durability but also enhances its workability.

[0020] 2. The functions of each raw material in component B are as follows: Water glass: Water glass can react with calcium hydroxide in cement hydration products to form calcium silicate gel, accelerating the hardening process of cement and improving the early strength of the material. Simultaneously, water glass can also react with active ingredients in additives, further enhancing the adhesion and density of the material.

[0021] Tetra-armed polyethylene glycol (TEG): TEG possesses a unique molecular structure with a weight-average molecular weight of 10kJ - 20kJ. This suitable molecular weight allows TEG to form a three-dimensional network structure within materials, intertwining with cement hydration products and water glass reaction products, thus enhancing the material's toughness and resistance to deformation. Furthermore, TEG exhibits excellent hydrophilicity and adsorption properties, enabling it to adsorb onto the walls of karst pipes, improving grout retention and reducing grout loss in flowing water.

[0022] Therefore, when components A and B are mixed, the hydration reactions of cement and additives, the reaction between water glass and calcium hydroxide, and the network formation process of four-arm polyethylene glycol synergistically interact. This network structure restricts the movement of cement hydration products and water glass reaction products, allowing them to be more evenly distributed throughout the material and improving its mechanical properties. Simultaneously, the synergistic effect of additives and water glass promotes the hydration reaction of cement, accelerates the hardening rate of the material, and improves its early strength. This synergistic effect enables the material to rapidly solidify under dynamic water conditions in karst pipes, forming a stable sealing structure and achieving efficient sealing. Detailed Implementation

[0023] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0024] Unless otherwise specified, all raw materials, reagents, instruments, and equipment used in this invention can be purchased commercially or prepared using existing methods. For example, boron mud is a grayish-white or yellowish-white solid waste generated during the production of boric acid, borax, and other products. Its main components include: MgO (34.6-45.9% by weight), SiO2 (22.3-35.5% by weight), B2O3 (2.1-5.4% by weight), and Fe2O3 (5.7-10.8% by weight), etc., and its code in the "Solid Waste Classification and Code Catalog" is 261-012-S16; green mud... The green mud is from the causticizing section of the alkali recovery section of a paper mill. Its main components include: CaO (37.1-42.5% by weight), SiO2 (4.9-7.1% by weight), MgO (3.0-4.4% by weight), Na2O (5.4-6.2% by weight), and Al2O3 (1.1-2.0% by weight). Its code in the "Solid Waste Classification and Code Catalog" is 221-006-S15.

[0025] The present invention will be further illustrated below with reference to specific embodiments. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the invention. Experimental methods in the following embodiments, unless otherwise specified, are generally performed according to national standards. If no corresponding national standard exists, then generally accepted international standards, conventional conditions, or conditions recommended by the manufacturer are followed.

[0026] Example 1 This example provides a grouting and sealing material for karst pipelines, the grouting and sealing material comprising component A and component B in a volume ratio of 3.5:1; By weight, component A comprises the following raw materials: 95 parts cement (specifically, silicate cement with a strength grade of 42.5), 7 parts additives, 2 parts water-reducing agent (specifically, polycarboxylate water-reducing agent, model PCE-412), and 100 parts water; The additive is obtained by calcining and ball milling boron mud and green mud in a weight ratio of 11:4. The working conditions for calcination include: calcination temperature of 500℃ and calcination time of 1.5 hours. The working conditions for ball milling include: ball-to-material ratio of 6:1, ball milling media of zirconia balls, ball milling time of 1.5 hours and ball milling speed of 200 rpm. By weight, component B comprises the following raw materials: 26.5 parts of water glass (modulus 2.2), 1.5 parts of four-arm polyethylene glycol (weight average molecular weight 20k), and 100 parts of water.

[0027] The preparation method of the above-mentioned grouting and sealing material for karst pipelines includes the following steps: The raw materials in component A are mixed to obtain component A; The raw materials in component B are mixed to obtain component B; The A component and the B component are mixed to obtain the grouting and sealing material for karst pipelines.

[0028] Example 2 This example provides a grouting and sealing material for karst pipelines, the grouting and sealing material comprising component A and component B in a volume ratio of 3:1; By weight, component A comprises the following raw materials: 90 parts cement (specifically, silicate cement with a strength grade of 42.5), 5 parts additives, 1 part water-reducing agent (specifically, polycarboxylate superplasticizer, model PCE-412), and 95 parts water; The additive is obtained by calcining and ball milling boron mud and green mud in a weight ratio of 10:3. The working conditions for calcination include: calcination temperature of 450℃ and calcination time of 2 hours. The working conditions for ball milling include: ball-to-material ratio of 5:1, ball milling media of zirconia balls, ball milling time of 2 hours and ball milling speed of 200 rpm. By weight, component B comprises the following raw materials: 20 parts water glass (modulus 2.0), 0.5 parts four-arm polyethylene glycol (weight average molecular weight 10k) and 95 parts water.

[0029] The preparation method of the above-mentioned grouting and sealing material for karst pipelines is the same as that in Example 1.

[0030] Example 3 This example provides a grouting and sealing material for karst pipelines, the grouting and sealing material comprising component A and component B in a volume ratio of 4:1; By weight, component A comprises the following raw materials: 100 parts cement (specifically, silicate cement with a strength grade of 42.5), 10 parts additives, 3 parts water-reducing agent (specifically, polycarboxylate water-reducing agent, model PCE-412), and 105 parts water; The additive is obtained by calcining and ball milling boron mud and green mud in a weight ratio of 13:5. The working conditions for calcination include: calcination temperature of 550℃ and calcination time of 1 hour. The working conditions for ball milling include: ball-to-material ratio of 8:1, ball milling media of zirconia balls, ball milling time of 1 hour and ball milling speed of 200 rpm. By weight, component B comprises the following raw materials: 30 parts water glass (modulus 2.5), 2 parts four-arm polyethylene glycol (weight average molecular weight 20k), and 105 parts water.

[0031] The preparation method of the above-mentioned grouting and sealing material for karst pipelines is the same as that in Example 1.

[0032] Example 4 This example provides a grouting and sealing material for karst pipelines and its preparation method, which differs from Example 1 only in that: (1) The weight ratio of the boron mud and the green mud is 1:1.

[0033] Comparative Example 1 This example provides a grouting and sealing material for karst pipelines and its preparation method, which differs from Example 1 only in that: (1) The additive is obtained only from boron mud through calcination and ball milling (i.e., without the addition of green mud).

[0034] Comparative Example 2 This example provides a grouting and sealing material for karst pipelines and its preparation method, which differs from Example 1 only in that: (1) The additive is obtained solely from green clay through sequential calcination and ball milling (i.e., without the addition of boron clay).

[0035] Comparative Example 3 This example provides a grouting and sealing material for karst pipelines and its preparation method, which differs from Example 1 only in that: (1) The weight-average molecular weight of the four-arm polyethylene glycol is 5k.

[0036] Test case This example demonstrates the performance testing of the grouting and sealing materials for karst pipelines obtained in Examples 1-4 and Comparative Examples 1-3.

[0037] 1) Mechanical performance test: The grouting sealing material is tested at a depth of 25m. 3 The material was poured into the mold at a set pouring speed of / h. After the outer surface of the material had initially set, it was finished. The material was then left to stand in a dry and ventilated place for 2 hours before demolding. After demolding, the material was placed in a standard curing room with a temperature of (23±1)℃ and a relative humidity of ≥95% for curing. The 3-day compressive strength was measured, and the results are shown in Table 1.

[0038] 2) Slurry retention rate test: The test was conducted in a transparent plexiglass tube with an inner diameter of 150 mm and a length of 10 m. The inclination angle of the transparent plexiglass tube was 30° and the water velocity was 1.5 m / s. The results are shown in Table 1.

[0039] Table 1 As shown in Table 1, compared with Comparative Examples 1-3, the grouting and sealing materials for karst pipelines provided in Examples 1-4 of the present invention have superior mechanical properties and higher grout retention rates. Meanwhile, in Comparative Examples 1 and 2, the absence of a combination of boron mud and green mud resulted in varying degrees of reduction in mechanical properties and grout retention rates. In Comparative Example 3, the small molecular weight of the four-arm polyethylene glycol led to shorter molecular chains and increased diffusion loss, resulting in a significant decrease in grout retention rate. Furthermore, the grouting and sealing materials provided in the embodiments of the present invention have an initial setting time ≤30s and a final setting time ≤25min, which meets the sealing requirements for flowing water in karst pipelines.

[0040] In summary, the embodiments of the present invention provide a grouting and sealing material for karst pipelines and its preparation method. The present invention mainly improves the mechanical properties and grout retention rate of the obtained grouting and sealing material by adding four-arm polyethylene glycol of appropriate molecular weight and additives made of boron mud and green mud, so that it can meet the sealing requirements of flowing water in karst pipelines, and realizes the secondary utilization of solid waste, which is green and environmentally friendly.

[0041] Various embodiments of the present invention may exist in the form of a range; it should be understood that the description in the form of a range is merely for convenience and brevity and should not be construed as a hard limitation on the scope of the invention; therefore, it should be considered that the range description has specifically disclosed all possible subranges and single numerical values ​​within that range. For example, it should be considered that the range description from 1 to 6 has specifically disclosed subranges such as from 1 to 3, from 1 to 4, from 1 to 5, from 2 to 4, from 2 to 6, from 3 to 6, etc., and single numbers within the range, such as 1, 2, 3, 4, 5, and 6, regardless of the range. Furthermore, whenever a numerical range is referred to herein, it means including any referenced number (fraction or integer) within the range referred to.

[0042] The above description is merely a specific embodiment of the present invention, enabling those skilled in the art to understand or implement the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the present invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features claimed herein.

Claims

1. A grouting and sealing material for karst pipelines, characterized in that, The grouting and sealing material includes component A and component B; By weight, component A comprises the following raw materials: 90-100 parts cement, 5-10 parts additives, 1-3 parts water-reducing agent and 95-105 parts water; The additive is obtained by calcining and ball milling boron mud and green mud in sequence. By weight, component B comprises the following raw materials: 20-30 parts water glass, 0.5-2 parts four-arm polyethylene glycol, and 95-105 parts water; The weight-average molecular weight of the four-armed polyethylene glycol is 10k~20k.

2. The grouting and sealing material for karst pipelines according to claim 1, characterized in that, The volume ratio of component A to component B is (3~4):

1.

3. The grouting and sealing material for karst pipelines according to claim 1, characterized in that, The weight ratio of the borax mud to the green mud is (10~13):(3~5).

4. The grouting and sealing material for karst pipelines according to claim 1, characterized in that, The working conditions for calcination include: calcination temperature of 450~550℃ and calcination time of 1~2 hours.

5. The grouting and sealing material for karst pipelines according to claim 1, characterized in that, The working conditions parameters of the ball mill include: a ball-to-material ratio of (5~8):1, a ball milling medium of zirconia balls, and a ball milling time of 1~2 hours.

6. The grouting and sealing material for karst pipelines according to any one of claims 1 to 5, characterized in that, By weight, component A comprises the following raw materials: 95 parts cement, 7 parts additives, 2 parts water-reducing agent and 100 parts water.

7. The grouting and sealing material for karst pipelines according to any one of claims 1 to 5, characterized in that, By weight, component B comprises the following raw materials: 26.5 parts water glass, 1.5 parts four-arm polyethylene glycol and 100 parts water.

8. The grouting and sealing material for karst pipelines according to any one of claims 1 to 5, characterized in that, The cement includes silicate cement, and the water-reducing agent includes polycarboxylate-based water-reducing agent.

9. The grouting and sealing material for karst pipelines according to any one of claims 1 to 5, characterized in that, The modulus of the water glass is 2.0 to 2.

5.

10. A method for preparing a grouting and sealing material for karst pipelines according to any one of claims 1 to 9, characterized in that, The preparation method of the grouting and sealing material for karst pipelines includes the following steps: The raw materials in component A are mixed to obtain component A; The raw materials in component B are mixed to obtain component B; The A component and the B component are mixed to obtain the grouting and sealing material for karst pipelines.

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