Organic in-situ polymerization modified cement-based grouting material for plugging leakage / water burst channel and grouting method of organic in-situ polymerization modified cement-based grouting material

Abstract

The invention discloses an organic in-situ polymerization modified cement-based grouting material for plugging a leakage / water burst channel and a grouting method of the organic in-situ polymerization modified cement-based grouting material. According to the method, high-flow-state cement paste containing an initiator and a low-viscosity organic monomer-cross-linking agent solution containing a polymerization inhibitor are injected through a Y-shaped grouting device, after the high-flow-state cement paste containing the initiator and the low-viscosity organic monomer-cross-linking agent solution containing the polymerization inhibitor are mixed at an outlet of the grouting device, good fluidity is kept within preset induction time under the control of the polymerization inhibitor, and it is guaranteed that the paste can be poured into the deep part of a leakage / water burst channel; after the preset induction time is exceeded, the initiator promotes the organic monomer to be subjected to rapid in-situ polymerization, the viscosity of the slurry is suddenly increased instantly, the slurry and the cement which is hydrated gradually form an organic-inorganic composite network, leakage is rapidly blocked, and the water washing resistance is improved. Controllable solidification time is realized by establishing a corresponding relation between a cement-organic matter-initiator-polymerization inhibitor ratio and induction time and adjusting a formula according to grouting flow velocity and distance. The plugging agent has the advantages of low viscosity, easiness in grouting, fast coagulability and high durability, and is suitable for anti-seepage plugging engineering under complex conditions.

Description

Technical Field

[0001] This invention relates to the field of leakage prevention technology, and in particular to an organic in-situ polymerized modified cement-based grouting material and its grouting method suitable for sealing leakage / water inrush channels. Background Technology

[0002] When underground structures and dam structures experience seepage / water inrush under water pressure, grouting materials are often used for rapid sealing. Cement-based materials have advantages such as low cost, good durability, and non-toxicity, but they are difficult to maintain a cohesive state under water scouring conditions, making effective and rapid sealing difficult. Traditional single-component cement grouts have high viscosity, making it difficult to inject into cracks under high-speed water flow conditions; although chemical grouting materials have low viscosity, their curing speed is limited by a single initiator system, often resulting in premature curing or failure to solidify in time, leading to loss with the water flow. CN112159200A discloses a cement-polymer composite grouting material that improves injectability and water scouring resistance by introducing polymer monomers; CN119797875A discloses a rapid-setting, high-strength, expansive seepage channel sealing material, method, and application, which uses an organic water-retaining agent to improve scouring resistance and utilizes the rapid hydration of inorganic materials to seal cracks and fill voids, with an initial setting time of 2-3 minutes and a final setting time of 4-6 minutes. However, current technologies have failed to effectively resolve the contradiction between the ease of injection / operability and the resistance to water erosion of grouting fluids. In particular, they cannot adjust the solidification timing of the grouting fluid according to on-site conditions such as leakage flow rate and underground depth of leakage channels, making it difficult to meet the needs of rapid and precise sealing under complex and variable working conditions.

[0003] Therefore, developing a grouting material and a matching grouting method that is easy to inject, highly operable, has a controllable setting time, and is highly tough and durable is a technical problem that urgently needs to be solved in this field. Summary of the Invention

[0004] The purpose of this invention is to provide a method for controlling in-situ polymerization of organic monomers. A grouting material system and method for sealing leakage / water inrush channels using the "cement hydration" stepwise reaction mechanism and dual-liquid injection process solves the problem in existing technologies where grouting materials cannot simultaneously achieve both injectability and rapid sealing in medium- and high-speed water flow environments.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: An organic in-situ polymerized modified cementitious grouting material for sealing leakage / water inrush channels comprises a first liquid and a second liquid, wherein the first liquid is a highly fluid cement slurry containing an initiator, and the second liquid is a low-viscosity grout (viscosity 1~20 mP at 25°C). organic monomers of s) Crosslinking agent The polymerization inhibitor solution has a volume ratio of the first liquid to the second liquid of (1:1) to (3:1).

[0006] The organic monomer is selected from acrylates, acrylamide, sodium methacrylate, hydroxymethylacrylamide, and 2... Acrylamide 2 One or more of methyl propanesulfonic acid (AMPS) are used, with the organic monomer content being 4.0% to 12.0% of the cement mass.

[0007] The crosslinking agent is one of polyethylene glycol diacrylate (PEGDA, Mn=400-600) and N,N'-methylenebisacrylamide (MBA), and its dosage is 0.5% to 2.5% of the mass of the organic monomer.

[0008] The polymerization inhibitor is one of hydroquinone, p-hydroxyanisole, and hydrogen ester monomethyl ether, and its dosage is 0.015% to 0.25% of the mass of the organic monomer.

[0009] The initiator is one of potassium persulfate or ammonium persulfate, and its dosage is 0.5% to 5.0% of the mass of the organic monomer.

[0010] The components and proportions of the high-fluidity cement slurry are as follows by weight: 100 parts cement, 25-50 parts water, and 0.2-0.5 parts polycarboxylate superplasticizer.

[0011] The present invention also provides a grouting method for sealing leakage / water inrush channels, comprising the following steps: A Y-type grouting device with two independent feed channels is used to instantly mix the first liquid and the second liquid at the grout outlet to form a mixed grout. Then, it is injected into the leakage channel. The induction time and flow rate are set so that the mixed grout is completely injected into the leakage area within a preset time. After standing, the organic in-situ polymerized modified cement-based grouting material solidifies, and the sealing is completed.

[0012] Specifically, the induction time is determined as follows: The distance L between the junction of the first and second liquids in the Y-shaped device and the end of the Y-shaped device (i.e., the injection point of the leakage channel), and the injection rate V are measured. Substituting these values ​​into the formula T=L / V yields the time T, or induction time, for the first and second liquids to flow through the Y-shaped device after mixing. This induction time is achieved through the inhibitory effect of the polymerization inhibitor. The inhibitor suppresses the polymerization reaction within a preset time, maintaining the fluidity of the slurry. Once this time is exceeded, the inhibitor is exhausted or its inhibitory effect weakens, and the initiator promotes rapid polymerization of the organic monomers, causing a sudden increase in slurry viscosity and achieving rapid sealing.

[0013] Furthermore, the ratio of the total water content in the first liquid and the second liquid to the mass of the cement, i.e. the total water-cement ratio of the system, is controlled between 0.4 and 0.6.

[0014] Furthermore, the induction time is set to 1~35 min, and the flow rate is set to 0.05~0.5 m / s.

[0015] A grouting material system for sealing leakage / water inrush includes an organic in-situ polymerized modified cement-based grouting material for sealing leakage / water inrush channels as described above, and a Y-type grouting device for achieving separate delivery of two liquids and mixing at the grout outlet.

[0016] The mechanism of action of the grouting material provided by this invention in sealing leakage / water inrush channels includes the following: 1. Grouting process: The first liquid and the second liquid are instantaneously mixed at the grout outlet to form a mixed slurry. Under the inhibition of the polymerization inhibitor, it maintains good fluidity within a preset induction time, which facilitates the rapid injection of the slurry into the leakage channel along the grouting pipe. When the induction time is exceeded, the inhibition of the polymerization inhibitor weakens or disappears, the initiator starts free radical polymerization, the organic monomers rapidly polymerize in situ to form a three-dimensional network, and the viscosity of the slurry increases instantaneously and solidifies.

[0017] 2. Induction time control: Establishment of cement induction time control through experiments. organic monomers Initiator The relationship between the multi-component ratio of the polymerization inhibitor and the induction time required for a sudden increase in the viscosity of the mixed slurry is calculated based on parameters such as the distance from the mixing point of the grouting device to the leakage point (which depends on the depth of the leakage channel from the ground in the actual project) and the grouting flow rate (the injection speed depends on the channel size; if the channel is large, enough slurry should be injected into the channel per unit time, so the injection speed should be appropriately increased). The required induction time (i.e., the time obtained by dividing the distance L from the mixing point to the endpoint in the Y-type device by the injection speed V) can be determined by adjusting the ratio of organic monomers, initiators, and polymerization inhibitors in the mixture. The ratio of initiators, polymerization inhibitors, and each component is adjusted to ensure that the slurry does not solidify prematurely during injection and solidifies rapidly at the predetermined position.

[0018] 3. Sealing mechanism: The polymer network after in-situ polymerization and the gradually hydrated cement together constitute an organic... In the inorganic composite system, the hydration products of cement fill the polymer network and enhance the interfacial adhesion. The polymer chains and cement hydration products form a strong bond through charge adsorption, coordination bonds, etc., which significantly improves the erosion resistance and long-term durability of the sealing layer.

[0019] In the grouting material system provided by this invention, the proportions of each key component can be adjusted within the following ranges: After mixing the two liquids, the mass ratio of water to cement is 0.4 to 0.6. The dosage of fluidity modifier (superplasticizer) in high-fluidity cement slurry is 0.1% to 0.5% of the cement mass; The organic monomer content is 4.0% to 12.0% of the cement mass; The initiator dosage is 0.5% to 5.0% of the organic monomer mass; The crosslinking agent is added at a concentration of 0.5% to 2.5% of the organic monomer mass. The amount of polymerization inhibitor is 0.015% to 0.25% of the mass of the organic monomer.

[0020] Compared with the prior art, the present invention has the following beneficial effects: 1. Balancing injectionability and rapid solidification: This invention maintains low viscosity and easy injection during the grouting process through two-liquid separation and synergistic regulation of initiator / polymerization inhibitor. It solidifies rapidly after entering the target location, making it suitable for complex environments such as leakage or water inrush.

[0021] 2. High strength and good durability of the sealing layer: The three-dimensional network structure formed by the rapid polymerization of organic monomers and the inorganic skeleton formed by the gradual hydration of cement are interlocked, which can significantly improve the mechanical strength and durability of the final sealing layer and overcome the problems of easy aging and peeling of the solidified layer of single organic or inorganic materials.

[0022] 3. Adjustable induction time: By adjusting the dosage and ratio of initiator and polymerization inhibitor, the induction time and solidification time of the slurry can be customized according to different crack lengths and flow velocities to meet the plugging needs of complex working conditions.

[0023] 4. Wide applicability: The raw materials used are readily available, and the formula can be adjusted according to project needs; the Y-type grouting device has a simple structure, making it easy to promote and apply. This invention does not have special requirements for the structure of the Y-type grouting device; it is generally a symmetrical "Y" structure. Its core lies in its ability to separately transport the two liquids and instantly and uniformly mix them at the grout outlet. This is crucial for ensuring sufficient contact between the organic monomer and the initiator, achieving a controllable and consistent polymerization reaction. The mixed grout is then introduced into the leak to be sealed to complete the grouting process. Attached Figure Description

[0024] Figure 1 A schematic diagram of the Y-type grouting device used in this invention.

[0025] Figure 2 A schematic diagram showing the change in viscosity of the mixed slurry over time under different initiator / inhibitor ratios. Detailed Implementation

[0026] The present invention will be further described below with reference to specific embodiments, but this does not limit the scope of protection of the present invention. In the following embodiments, unless otherwise specified, the experimental methods used are conventional methods, and the materials and reagents used are commercially available.

[0027] Example 1: Induction time approximately 2 minutes, total water-cement ratio 0.4, two-liquid volume ratio 3:1 (1) Preparation of the first liquid: 100 parts of PO 42.5 cement, 30 parts of water, 0.2 parts of polycarboxylate superplasticizer, and 0.12 parts of potassium persulfate (KPS). Mix the above materials evenly to obtain the liquid.

[0028] (2) Preparation of the second liquid: 6 parts sodium acrylate (AANa), 10 parts water, 0.05 parts N,N'-methylenebisacrylamide (MBA), and 0.0012 parts hydroquinone. Mix the above materials evenly to obtain the liquid.

[0029] (3) Preparation of grouting material: The first liquid and the second liquid are mixed in a volume ratio of 3:1 and stirred evenly to obtain the grouting material.

[0030] Effect: The viscosity of the mixed slurry is below 100 mPa·s within 2 minutes, and then increases rapidly to above 1000 mPa·s within 30 seconds, and gels quickly.

[0031] Example 2: Induction time approximately 5 minutes, total water-cement ratio 0.4, two-liquid volume ratio 2:1 (1) Preparation of the first liquid: 100 parts of PO 42.5 cement, 20 parts of water, 0.3 parts of polycarboxylate superplasticizer, and 0.075 parts of ammonium persulfate (APS). Mix the above materials evenly to obtain the liquid.

[0032] (2) Preparation of the second liquid: 5 parts acrylamide (AM), 1 part 2-acrylamide-2-methylpropanesulfonic acid (AMPS), 20 parts water, 0.1 parts polyethylene glycol diacrylate, and 0.003 parts hydroquinone monomethyl ether. Mix the above materials evenly to obtain the liquid.

[0033] (3) Preparation of grouting material: The first liquid and the second liquid are mixed in a volume ratio of 2:1 and stirred evenly to obtain the grouting material.

[0034] Results: The mixture maintained its fluidity for approximately 5 minutes before rapidly gelling.

[0035] Example 3: Induction time approximately 8.5 minutes, total water-cement ratio 0.5, two-liquid volume ratio 2:1 (1) Preparation of the first liquid: 100 parts of PO 42.5 cement, 30 parts of water, 0.4 parts of polycarboxylate superplasticizer, and 0.08 parts of potassium persulfate (KPS). Mix the above materials evenly to obtain the liquid.

[0036] (2) Preparation of the second liquid: 4 parts sodium acrylate (AANa), 1 part sodium methacrylate (MASS), 20 parts water, 0.1 parts polyethylene glycol diacrylate, and 0.0032 parts hydroquinone monomethyl ether. Mix the above materials evenly to obtain the liquid.

[0037] (3) Preparation of grouting material: The first liquid and the second liquid are mixed in a volume ratio of 3:1 and stirred evenly to obtain the grouting material.

[0038] Effect: The slurry reacts rapidly after mixing, and the viscosity increases sharply after about 8.5 minutes, achieving rapid sealing.

[0039] Example 4: Induction time approximately 10 minutes, total water-cement ratio 0.5, two-liquid volume ratio 2:1 (1) Preparation of the first liquid: 100 parts of PO 42.5 cement, 25 parts of water, 0.4 parts of polycarboxylate superplasticizer, and 0.06 parts of potassium persulfate (KPS). Mix the above materials evenly to obtain the liquid.

[0040] (2) Preparation of the second liquid: 4 parts sodium acrylate (AANa), 1 part sodium methacrylate (MASS), 25 parts water, 0.1 parts polyethylene glycol diacrylate, and 0.0048 parts hydroquinone monomethyl ether. Mix the above materials evenly to obtain the liquid.

[0041] (3) Preparation of grouting material: The first liquid and the second liquid are mixed in a volume ratio of 2:1 and stirred evenly to obtain the grouting material.

[0042] Effect: The slurry reacts rapidly after mixing, and its viscosity increases sharply after about 10 minutes, achieving rapid sealing.

[0043] Example 5: Induction time approximately 15 minutes, total water-cement ratio 0.6, two-liquid volume ratio 3:2 (1) Preparation of the first liquid: 100 parts of PO 42.5 cement, 25 parts of water, 0.4 parts of polycarboxylate superplasticizer, and 0.06 parts of potassium persulfate (KPS). Mix the above materials evenly to obtain the liquid.

[0044] (2) Preparation of the second liquid: 4 parts sodium acrylate (AANa), 1 part sodium methacrylate (MASS), 35 parts water, 0.1 parts polyethylene glycol diacrylate, and 0.0048 parts hydroquinone monomethyl ether. Mix the above materials evenly to obtain the liquid.

[0045] (3) Preparation of grouting material: The first liquid and the second liquid are mixed in a volume ratio of 3:2 and stirred evenly to obtain the grouting material.

[0046] Effect: The slurry reacts rapidly after mixing, and its viscosity increases sharply after about 15 minutes, achieving rapid sealing.

[0047] Example 6: Induction time approximately 6 minutes, total water-cement ratio 0.6, two-liquid volume ratio 1:1 (1) Preparation of the first liquid: 100 parts of PO 42.5 cement, 20 parts of water, 0.5 parts of polycarboxylate superplasticizer, and 0.06 parts of ammonium persulfate (APS). Mix the above materials evenly to obtain the liquid.

[0048] (2) Preparation of the second liquid: 4 parts acrylamide (AM), 2 parts sodium acrylate (AANa), 40 parts water, 0.06 parts N,N'-methylenebisacrylamide (MBA), and 0.0025 parts p-hydroxyanisole. Mix the above materials evenly to obtain the liquid.

[0049] (3) Preparation of grouting material: The first liquid and the second liquid are mixed at a volume ratio of 1:1 and stirred evenly to obtain the grouting material.

[0050] Effect: The slurry reacts rapidly after mixing, and its viscosity increases sharply after about 6 minutes, achieving rapid sealing.

[0051] Figure 1 This is a schematic diagram of the Y-type grouting device used in this invention. A symmetrical Y-shaped grouting device is employed, with the first and second liquids injected simultaneously from both ends. The flow rates of the two grouts are controlled to match to ensure mixing at a preset volume ratio. They are instantaneously mixed at the outlet end (the junction point in the Y-type device) and form a mixed grout under the action of a spiral mixer. After flowing into the grouting hole, it enters the depth of the crack. At this time, the grout maintains good fluidity within a preset induction time under the inhibition of the polymerization inhibitor. When this induction time is exceeded, the inhibition effect of the polymerization inhibitor weakens or disappears, and the initiator initiates free radical polymerization. The organic monomers rapidly polymerize in situ to form a three-dimensional network, causing the grout viscosity to rise instantaneously and solidify, thereby plugging the leakage.

[0052] Figure 2 The graphs shown in Examples 1-6 illustrate the viscosity of the mixed slurry over time under different initiator / inhibitor ratios, reflecting the influence of different component dosages and induction times on the viscosity of the mixed slurry. It can be seen that the induction time is significantly shortened as the initiator / inhibitor ratio decreases. The addition of low initiator dosage and high inhibitor dosage further prolongs the induction time. Therefore, the induction time can be precisely controlled by adjusting the initiator-inhibitor ratio, as in Examples 2-15 minutes. In practical applications, the required induction time needs to be calculated based on actual working conditions and measured parameters, including the depth of the leakage channel from the ground and the grouting flow rate (the flow rate after mixing the two liquids). The ratios of initiator, inhibitor, and other components can also be adjusted to prevent premature solidification of the slurry during injection and to ensure rapid solidification at the predetermined location. Therefore, the induction time under actual working conditions is not limited to the time range of the above examples.

Claims

1. An organic in-situ polymerized modified cement-based grout material for leakage / gushing passage plugging, characterized by, comprising a first liquid and a second liquid, wherein the first liquid is a high-fluid high-fluid cement slurry containing an initiator and the second liquid is a low viscosity organic monomer crosslinking agent a solution of a polymerization inhibitor, the first liquid and the second liquid being in a volume ratio of (1:1) to (3:1).

2. The organic in-situ polymerization modified cement-based grout material for leakage / gushing passage plugging according to claim 1, characterized in that, The organic monomer is selected from the group consisting of acrylic acid salts, acrylamides, sodium methacrylate, hydroxymethyl acrylamide, 2 acrylamide 2 one or more of methylpropanesulfonic acid, with the organic monomer content being between 4.0% and 12.0% by mass of the cement.

3. The organic in-situ polymerization modified cement-based grout material for leakage / gushing passage plugging according to claim 1, characterized in that, The crosslinking agent is one of polyethylene glycol diacrylate and N,N'-methylene bisacrylamide, and the amount is 0.5% to 2.5% of the mass of the organic monomer.

4. The organic in-situ polymerization modified cement-based grout material for leakage / gushing passage plugging according to claim 1, characterized in that, The polymerization inhibitor is one of hydroquinone, p-hydroxyanisole and hydrogen ester monomethyl ether, and the amount is 0.015% to 0.25% of the mass of the organic monomer.

5. The organic in-situ polymerizing modified cement-based grout material for leakage / gushing passage plugging according to claim 1, characterized in that, The initiator is one of potassium persulfate and ammonium persulfate, and the amount is 0.5% to 5.0% of the mass of the organic monomer.

6. The organic in-situ polymerizing modified cement-based grout material for leakage / gushing passage plugging according to claim 1, characterized in that, The components and proportions of the high-fluidity cement slurry are as follows: cement 100 parts, water 25 to 50 parts, and polycarboxylic acid water reducer 0.2 to 0.5 parts.

7. A grouting method for sealing a leakage / gushing passage using the grouting material according to any one of claims 1 to 6, characterized in that, The method comprises the following steps: The Y-shaped grouting device with two independent feeding channels is used to mix the first liquid and the second liquid at the grouting end to form a mixed slurry, and then the mixed slurry is injected into the leakage channel, and the induction time (T) and the flow rate (V) are set to make the mixed slurry flow into the leakage position within a preset time, and the organic monomer is immediately polymerized to make the grouting material coagulate to complete the plugging. Specifically, the determination method of the induction time is as follows: the distance L between the intersection point of the first liquid and the second liquid in the Y-shaped device and the end of the Y-shaped device is measured, and the grouting speed V is measured, and then the formula T=L / V is used to obtain the time T of the mixed first liquid and second liquid flowing through the Y-shaped device, that is, the induction time.

8. The grouting method according to claim 7, characterized in that, The mass ratio of the total amount of water in the first liquid and the second liquid to the cement is controlled to be 0.4 to 0.

6.

9. The grouting method according to claim 7, characterized by, The induction time is set to be 1 to 35 min, and the flow rate is set to be 0.05 to 0.5 m / s.

10. A system for plugging a leak / gushing, comprising: The method comprises the following steps: The method comprises the following steps:

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