High-permeability nano-modified acrylic salt grouting material and preparation method thereof

Abstract

The application belongs to the field of tunnel and underground engineering stratum reinforcement grouting material, and provides a high-permeability nano-modified acrylate grouting material and a preparation method thereof.The nano-modified acrylate composite grouting material is formed by mixing component A and component B.The component A comprises 50-120 parts of acrylate solution, 0.1-10 parts of crosslinking agent, 1-60 parts of nano-modifying agent, 0-0.05 parts of surfactant, 0.1-10 parts of silane coupling agent and 0.1-4 parts of accelerator.The component B comprises 0.1-4 parts of initiator, 1-40 parts of rubber additive, 5-120 parts of inorganic reinforcing agent and 0-20 parts of water.The material has the characteristics of low viscosity, controllable gel time, strong injectability, good permeation and diffusion effect, high consolidation body strength and good toughness, can significantly improve the physical and mechanical properties of dense soft and weak surrounding rock of tunnels and underground engineering, greatly reduce the risk of major disasters such as water and mud inrush and collapse, and ensure the safety of engineering construction.

Description

Technical Field

[0001] This invention belongs to the technical field of grouting materials for tunnel and underground engineering strata reinforcement, and particularly relates to a high-permeability nano-modified acrylate grouting material and its preparation method. Background Technology

[0002] The information disclosed in this background section is intended only to enhance understanding of the overall background of the invention and is not necessarily to be construed as an admission or in any way implying that such information constitutes prior art known to those skilled in the art.

[0003] In recent years, the scale and speed of tunnel and underground engineering construction have been continuously increasing, and the geological conditions faced have become increasingly complex. Tunnel and underground engineering construction often encounters unfavorable geological formations such as fault fracture zones and water-rich soft rock, which can easily induce major geological disasters such as water and mud inrushes and surrounding rock collapses. Among the many unfavorable geological types, dense and weak strata, represented by siltstone and fine sand, are widely distributed, highly hazardous, and difficult to manage, posing a great challenge to the safe construction of traffic tunnels and water diversion tunnels.

[0004] Taking a water diversion project as an example, a large-scale distribution of water-rich silty rock strata was exposed during construction, resulting in dozens of water and mud inrushes, large deformations of the surrounding rock, and landslides, posing extremely high construction safety risks. This silty rock strata is a fine powdery medium formed under the compression and grinding action of faults. It is characterized by small particle size, high density, low cohesion, weak bearing capacity, and severe softening upon contact with water. Under the influence of groundwater, it is extremely prone to seepage and damage, leading to disasters.

[0005] Pre-consolidation grouting is a primary method for reinforcing and impermeable treatment of dense and weak strata such as siltstone. However, due to the small particle size and poor permeability of these strata, conventional grouting materials often fail to achieve the desired results. Currently, commonly used grouting materials in engineering mainly include inorganic grouting materials (such as cement and water glass) and organic chemical grouting materials (such as polyurethane, acrylamide, and lignin). The most commonly used inorganic grouting materials, such as single-component cement grout and cement-water glass two-component grout, are difficult to penetrate and diffuse in these dense and weak strata. Furthermore, high-pressure fracturing grouting can cause problems such as surrounding rock deformation and stress accumulation. While water glass grouting materials have some permeability, their consolidated strength is low, and their consolidation performance is poor in water-rich environments. Commonly used organic grouting materials, such as acrylamide and lignin grouting materials, have poor environmental friendliness, while polyurethane materials have high viscosity and poor injectability, making them unsuitable for dense and weak strata. Compared to other organic grouting materials, acrylate materials have strong injectability in dense formations and great modification potential, but they suffer from low strength and adhesion. For example, patent CN106927719A discloses an acrylate composite grouting filler material and its preparation method and application, which is prepared by mixing material A and material B. Material A consists of the following components by weight: 30-40 parts of main agent, 6-10 parts of crosslinking agent, and 50-64 parts of water. The main agent is a mixture of magnesium acrylate, calcium acrylate, and copper acrylate, and the crosslinking agent is one or a mixture of two of polyethylene glycol diallyl ether and bisphenol A diallyl ether. Material B consists of the following components by weight: 3-6 parts of accelerator, 1-4 parts of initiator, 3-7 parts of composite reinforcing agent (nano silica), 0.04-0.3 parts of additive, 0-0.1 parts of retarder, and 82.6-92.96 parts of water. However, the inventors discovered that the strength of the solidified body prepared using this material still needs to be improved. Summary of the Invention

[0006] To overcome the problem that existing grouting materials are not well-suited for dense and weak strata, the main objective of this invention is to provide a high-permeability nano-modified acrylate grouting material for the reinforcement and seepage prevention of dense and weak strata such as siltstone. This material has the characteristics of low viscosity, controllable gelation time, strong injectability, good penetration and diffusion effect, high strength of the consolidated body, and good toughness. It can significantly improve the physical and mechanical properties of dense and weak surrounding rock in tunnels and underground engineering, greatly reduce the risk of major disasters such as water inrush, mudslides, and collapses, and ensure the safety of engineering construction.

[0007] To achieve the above objectives, the present invention adopts the following technical solution:

[0008] In a first aspect, the present invention provides a high-permeability nano-modified acrylate grouting material, comprising: component A and component B, wherein the volume ratio of component A to component B is 1:0.2-1;

[0009] Component A is composed of the following raw materials in parts by weight: 50-120 parts acrylate solution, 0.1-10 parts crosslinking agent, 1-60 parts nano-modifier, 0-0.05 parts surfactant, 0.1-10 parts silane coupling agent, and 0.1-4 parts accelerator.

[0010] Component B is composed of the following raw materials in parts by weight: 0.1-4 parts initiator, 1-40 parts rubber additives, 5-120 parts inorganic reinforcing agent, and 0-20 parts water.

[0011] To meet the grouting treatment needs of dense formations, this invention has developed a highly permeable, strongly cementing, nano-modified acrylate grouting material.

[0012] A second aspect of the present invention provides a method for preparing a high-permeability nano-modified acrylate grouting material, comprising:

[0013] Add crosslinking agent, nano-modifier, surfactant and accelerator to acrylate solution respectively, mix well, and then add silane coupling agent to form component A slurry for later use. The nano-modifier is added in multiple batches.

[0014] Mix the initiator, rubber additives, inorganic reinforcing agent, and water evenly to form component B slurry, and set aside for later use.

[0015] Mix component A and component B grout uniformly at a volume ratio of 1:0.2-1 to form a high-permeability nano-modified acrylate grouting material.

[0016] A third aspect of the present invention provides the application of the above-described high-permeability nano-modified acrylate grouting material in grouting of dense formations.

[0017] Beneficial effects of the present invention

[0018] (1) The material of this invention consists of two components, A and B. Component A includes an acrylate solution, a green crosslinking agent, a nano-modifier, a surfactant, a silane coupling agent, and an accelerator; component B includes an initiator, an inorganic reinforcing agent, a rubber additive, and water. The acrylate is the main component of component A. Due to its simple molecular structure and low aqueous solution viscosity, it ensures the overall injectability and permeability of the slurry. The working principle of the slurry material is as follows: after the accelerator in component A contacts the initiator in component B, a redox free radical initiation system is formed. The free radicals break the double bonds in the acrylate monomers and generate molecular chains, which then react with the green crosslinking agent to gradually form a three-dimensional network structure, giving the gel high elasticity and high toughness. Therefore, the solidified body formed after the slurry is injected into a dense and weak stratum has high tensile and compressive strength. To further improve its solidification strength while ensuring good injectability, silica-rich nanomaterials are added as modifiers and reinforcements. Since the nanoparticles are uniformly distributed in the acrylate organic matrix, they have almost no effect on the viscosity of the slurry. However, the interaction of hydroxyl groups on the surface of the nanomaterials and the formation of silicon-oxygen bonds (Si-O-Si) after dehydration condensation have an enhancing effect on the strength of the solidified body. Organic acrylate gels have good toughness but low strength, while inorganic gels formed by silicon-oxygen bonds have high strength but poor toughness. By adding silane coupling agents as a "bridge" between organic and inorganic components, the compatibility of the two matrices is enhanced, and the complementary properties of the two can be achieved, which can simultaneously improve the mechanical strength and toughness of the slurry gel.

[0019] (2) In this invention, rubber additives are used to improve the bonding performance of materials and the strength of solidified bodies, while inorganic reinforcing agents can significantly improve the strength of pulverized rock solidified bodies.

[0020] (3) The preparation method of the present invention is simple, practical and easy to promote. Attached Figure Description

[0021] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. Exemplary embodiments of the invention and their descriptions are used to explain the invention and do not constitute an improper limitation of the invention.

[0022] Figure 1 This is a microscopic photograph of the distribution of nanoparticles in component A prepared in Example 1 of the present invention.

[0023] Figure 2 The image shows the microscopic cementation morphology of the slurry prepared in Example 1 of this invention mixed with crushed rock.

[0024] Figure 3 The slurry prepared in Example 1 of this invention was mixed with crushed rock, and the solidified solidified body was subjected to a uniaxial compressive strength test.

[0025] Figure 4The internal structure of the fracture after fracturing of the grouting material prepared in Example 1 of this invention is shown.

[0026] Figure 5 Photograph of the solidified body of the grouting material prepared in Example 1 of the present invention in field application. Detailed Implementation

[0027] It should be noted that the following detailed descriptions are exemplary and intended to provide further illustration of the invention. Unless otherwise specified, all technical and scientific terms used in this invention have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0028] The first objective of this invention is to provide a high-permeability nano-modified acrylate grouting material for reinforcing dense and fractured strata and its preparation method.

[0029] A second objective of this invention is to provide an application of the above-mentioned high-permeability nano-modified acrylate grouting material.

[0030] To achieve the above objectives, the present invention specifically discloses the following technical solutions:

[0031] The above-mentioned nano-modified acrylate composite grouting material is composed of component A and component B, with a volume ratio of liquid A to liquid B of 1:0.2-1.

[0032] Component A is composed of the following components by weight: 50-120 parts acrylate solution, 0.1-10 parts crosslinking agent, 1-60 parts nano-modifier, 0-0.05 parts surfactant, 0.1-10 parts silane coupling agent, and 0.1-4 parts accelerator; Component B is composed of the following components by weight: 0.1-4 parts initiator, 1-40 parts rubber additives, 5-120 parts inorganic reinforcing agent, and 0-20 parts water.

[0033] In some embodiments, the acrylate solution is at least one of sodium acrylate, magnesium acrylate, calcium acrylate, and zinc acrylate;

[0034] In some embodiments, the crosslinking agent is at least one of polyethylene glycol monoallyl ether, polyethylene glycol dielyl ether, polyethylene glycol diacrylate, and polyethylene glycol diacrylate, wherein the molecular weight of polyethylene glycol is between 200 and 2000.

[0035] In some embodiments, the nano-modifier is nano-silica, nano-fly ash, nano-carbide slag, or nano-kaolin, wherein the particle size of the nano-reinforcing material ranges from 4 to 100 nm.

[0036] In some embodiments, the surfactant is at least one of fatty alcohol polyoxyethylene ether and alkylphenol polyoxyethylene ether.

[0037] In some embodiments, the silane coupling agent is at least one selected from vinylsilane, aminosilane, epoxysilane, mercaptosilane, and methacryloxysilane.

[0038] In some embodiments, the promoter is at least one selected from triethanolamine, diethanolamine, tetramethylethylenediamine, and triethylenediamine.

[0039] In some embodiments, the initiator is at least one selected from potassium persulfate, ammonium persulfate, sodium persulfate, and potassium persulfate.

[0040] In some embodiments, the rubber additive is at least one of solution-polymerized styrene-butadiene rubber, aqueous chlorinated rubber emulsion, nitrile emulsion, and acrylic emulsion.

[0041] In some embodiments, the inorganic reinforcing agent is a nano-silica sol, not limited to alkaline, neutral or acidic silica sol, with an average particle size of 7-80 nm.

[0042] The preparation method of the above-mentioned high-permeability nano-modified acrylate grouting material includes the following steps:

[0043] (1) Add crosslinking agent, nano-modifier, surfactant and accelerator to acrylate solution respectively, stir evenly, and then add silane coupling agent. The nano-modifier needs to be added in multiple batches to form component A slurry for later use.

[0044] (2) Add the initiator, rubber additives and inorganic reinforcing agent to water and stir evenly to form component B slurry for later use.

[0045] (3) Mix component A and component B uniformly at a volume ratio of 1:0.2-1 to form a high-permeability nano-modified acrylate grouting material.

[0046] The resulting acrylate grouting material has a viscosity of less than 10 cP, an adjustable initial setting time within 2 hours, high permeability, and strong injectability. Experimental results show that this grouting material, when mixed with powdery rock mass, forms a strongly bonded, highly tough consolidated body, such as... Figure 2 As shown, even when damaged, it still retains a certain strength. Artificially opening cracks in the consolidated body may even reveal stringy colloids, which can effectively bind rock particles. Figure 3 As shown.

[0047] The material is delivered using a dual-liquid pump during grouting. In field applications, the initial setting time of the grout is controlled by adjusting the volume ratio of liquid A and liquid B or by adjusting the content of accelerator and initiator, depending on the required grouting diffusion range. During grouting, liquids A and B are mixed at the orifice or inside the hole and injected into the target location. Adjustments are made based on factors such as the rock strata properties, grouting process, grouting location, and grouting section length.

[0048] The aforementioned high-permeability nano-modified acrylate grouting material can be applied to the treatment of major disasters such as water inrush and mud inrush in tunnels and underground engineering. It is especially suitable for rock masses that are dense, easily loosened by excavation disturbance, and easily turn into mud when exposed to water. It can effectively reinforce the surrounding rock mass, reduce the permeability of the rock mass, and reduce the occurrence of disasters such as collapse, water inrush and mud inrush.

[0049] The present invention will be further described in detail below with reference to specific embodiments. It should be noted that the specific embodiments are explanations of the present invention and not limitations thereof.

[0050] Example 1

[0051] The preparation of a high-permeability nano-modified acrylate grouting material includes the following steps:

[0052] (1) By weight, take 90 parts of 25% acrylate, 2 parts of crosslinking agent (ethylene glycol diacrylate), 2 parts of nano silica, 0.01 parts of fatty alcohol polyoxyethylene ether, 2 parts of accelerator (triethanolamine), and 3 parts of epoxy silane. Mix the above materials and stir thoroughly to prepare component A for later use.

[0053] (2) Take 0.2 parts of initiator (potassium persulfate), 80 parts of silica sol, 10 parts of water, and 10 parts of styrene-butadiene emulsion. Mix the above materials and stir thoroughly to prepare component B for later use.

[0054] (3) Mix components A and B thoroughly in a 1:1 ratio, and it can be used for grouting.

[0055] Example 2

[0056] The preparation of a high-permeability nano-modified acrylate grouting material includes the following steps:

[0057] (1) By weight, take 90 parts of 20% acrylate, 3 parts of crosslinking agent (ethylene glycol diacrylate), 4 parts of nano silica, 2 parts of accelerator (triethanolamine), and 2 parts of epoxy silane. Mix the above materials and stir thoroughly to prepare component A for later use.

[0058] (2) Take 0.1 parts of initiator (potassium persulfate), 20 parts of silica sol, 10 parts of water, and 5 parts of styrene-butadiene emulsion. Mix the above materials and stir thoroughly to prepare component B for later use.

[0059] (3) Mix components A and B thoroughly in a 1:1 ratio, and it can be used for grouting.

[0060] Example 3

[0061] The preparation of a high-permeability nano-modified acrylate grouting material includes the following steps:

[0062] (1) By weight, take 90 parts of 25% acrylate, 2 parts of crosslinking agent (ethylene glycol diacrylate), 2 parts of nano silica, 0.01 parts of surfactant, 4 parts of accelerator (triethanolamine), and 2 parts of epoxy silane. Mix the above materials and stir thoroughly to prepare component A for later use.

[0063] (2) Take 4 parts of initiator (potassium persulfate), 80 parts of silica sol, 10 parts of water and 10 parts of styrene-butadiene emulsion, mix the above materials and stir thoroughly to prepare component B for later use.

[0064] (3) Mix components A and B thoroughly in a 1:1 ratio, and it can be used for grouting.

[0065] Example 4

[0066] The preparation of a high-permeability nano-modified acrylate grouting material includes the following steps:

[0067] (1) By weight, take 90 parts of 25% acrylate, 2 parts of crosslinking agent (ethylene glycol dipropylene propyl ether), 2 parts of nano silica, 4 parts of accelerator (triethanolamine), and 2 parts of epoxy silane. Mix the above materials and stir thoroughly to prepare component A for later use.

[0068] (2) Take 4 parts of initiator (potassium persulfate), 80 parts of silica sol, 10 parts of water and 10 parts of styrene-butadiene emulsion, mix the above materials and stir thoroughly to prepare component B for later use.

[0069] (3) Mix components A and B thoroughly in a ratio of 1:0.8, and it can be used for grouting.

[0070] The crushed rock was sieved and mixed separately with the slurries prepared in Examples 1-4 above. After solidification, the compressive strength, permeability coefficient, solidification time, and viscosity of the solidified crushed rock were measured, and the results are as follows:

[0071] Table 1

[0072]

[0073] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A high-permeability nano-modified acrylate grouting material, characterized in that, It includes component A and component B, with a volume ratio of component A to component B of 1:0.8; Component A is composed of the following raw materials in parts by weight: 90 parts of 25% acrylate, 2 parts of ethylene glycol dipropylene propyl ether, 2 parts of nano silica, 4 parts of triethanolamine, and 2 parts of epoxy silane. Component B is composed of the following raw materials in parts by weight: 4 parts potassium persulfate, 80 parts silica sol, 10 parts water, and 10 parts styrene-butadiene emulsion. The particle size range of the nano-silica is 4-100 nm; The silica sol is not limited to alkaline, neutral or acidic silica sol, and has an average particle size of 7-80 nm. The acrylate solution is at least one of sodium acrylate, magnesium acrylate, calcium acrylate, and zinc acrylate.

2. A method for preparing a high-permeability nano-modified acrylate grouting material, characterized in that, include: By weight, take 90 parts of 25% acrylate, 2 parts of ethylene glycol dipropylene propyl ether, 2 parts of nano silica, 4 parts of triethanolamine, and 2 parts of epoxy silane. Mix the above materials and stir thoroughly to prepare component A for later use. Take 4 parts potassium persulfate, 80 parts silica sol, 10 parts water, and 10 parts styrene-butadiene emulsion, mix the above materials and stir thoroughly to prepare component B for later use; Mix components A and B thoroughly in a ratio of 1:0.8 to form a high-permeability nano-modified acrylate grouting material; The particle size range of the nano-silica is 4-100 nm; The silica sol is not limited to alkaline, neutral or acidic silica sol, and has an average particle size of 7-80 nm. The acrylate solution is at least one of sodium acrylate, magnesium acrylate, calcium acrylate, and zinc acrylate.

3. The application of the high-permeability nano-modified acrylate grouting material according to claim 1 in grouting of dense formations.

Images