Mudstone-friendly pumpable anchoring agent as well as preparation method and application thereof

Abstract

The invention relates to the technical field of deep ground engineering materials, in particular to a mudstone-friendly pumpable anchoring agent as well as a preparation method and application thereof. The anchoring agent is composed of a component A and a component B, wherein the component A comprises a first sodium silicate solution, a second sodium silicate solution, a catalyst, a chain extender, a thixotropic agent, polyether polyol, a modifier and a mudstone curing agent; and the component B comprises an isocyanate substance, a carboxyl-containing isocyanate derivative and a plasticizer. According to the invention, carboxyl-containing isocyanate, a hydrophilic modifier and a hydrophilic functional nano-material are introduced, so that the anchoring agent and a mudstone interface form a dual effect of chemical bond + hydrogen bond, and the interface bonding strength and anchoring force are remarkably improved; meanwhile, microcracks of the mudstone are filled with the nanometer materials, softening of the mudstone when meeting water is inhibited, and integration of rock affinity and rock fixation is achieved. The anchoring agent also has excellent pumpability, high compressive strength and construction convenience, and is especially suitable for anchoring engineering of mudstone strata.

Description

Technical Field

[0001] This invention relates to the field of deep-earth engineering materials technology, and in particular to a mud-loving rock-type pumpable anchoring agent, its preparation method, and its application. Background Technology

[0002] In deep-earth engineering, especially in projects involving mudstone strata, anchoring agents are key materials for ensuring the stability of engineering structures. They are used to firmly bond anchor bolts to the surrounding soil and rock layers and transfer loads. Currently, polyurethane-based anchoring agents are commonly used in engineering projects.

[0003] However, existing polyurethane anchoring agents have significant drawbacks in mudstone engineering applications: (1) Poor interfacial affinity: The surface of mudstone is rich in hydroxyl groups and has hydrophilicity, while the existing polyurethane anchoring agent has hydrophobic properties, and the two are incompatible. The interface is only bound by weak physical actions such as van der Waals forces, resulting in weak interfacial bonding force and easy delamination of the anchoring agent-mudstone interface; (2) The problem of mudstone's own stability has not been solved: Existing technology ignores the characteristics of mudstone that easily expands and softens when exposed to water. Water infiltration will cause the mudstone to expand and soften, which will cause the entire anchoring system to fail and the anchoring force to drop sharply; (3) Insufficient performance: The bonding strength between existing ordinary anchoring agents and mudstone is usually less than 3MPa, the anchoring force is only 50-150kN, and the 24h compressive strength is 30-40MPa, which is difficult to meet the requirements of mudstone engineering for high-performance anchoring agents.

[0004] Therefore, developing a high-performance anchoring agent that can bond well with mudstone and inhibit its softening has become a pressing technical problem in this field. Summary of the Invention

[0005] The technical problem this invention aims to solve is to overcome the shortcomings of existing technologies and provide a mudstone-compatible pumpable anchoring agent, its preparation method, and its application. The anchoring agent prepared by this invention can significantly improve the interfacial bonding force with mudstone, simultaneously strengthen the stability of the mudstone itself, and possesses excellent comprehensive performance and ease of construction.

[0006] The technical solution adopted by this invention to solve its technical problem is: A mudstone-friendly pumpable anchoring agent, consisting of component A and component B, is used by mixing component A and component B in a volume ratio of 1:1. The A component, by mass, comprises: 50-80 parts of the first sodium silicate solution, 20-50 parts of the second sodium silicate solution, 0.3 parts of the catalyst, 5-10 parts of the chain extender, 3-5 parts of the thixotropic agent, 2-4 parts of the polyether polyol, 2-4 parts of the modifier, and 2-4 parts of the mudstone solidifying agent. Component B, by mass, comprises: 90-110 parts of isocyanate, 10-30 parts of plasticizer, and 3-8 parts of carboxyl-containing isocyanate derivative.

[0007] The total mass fraction of the first sodium silicate solution and the second sodium silicate solution is 100 parts.

[0008] Through a specific combination and ratio of components A and B, their synergistic effect achieves the anchoring agent's mudstone affinity, high anchoring performance, and pumpability. A 1:1 volume ratio ensures ease of operation and stable performance during on-site construction. This forms the basis for all subsequent beneficial effects.

[0009] Furthermore, in component A, the first sodium silicate solution is a sodium silicate solution with a modulus of 2.1 to 2.8 and a Baume degree of 45 to 51°Bé. The second sodium silicate solution is a sodium silicate solution with a modulus of 2.8 to 3.5 and a Baume degree of 40 to 45°Bé.

[0010] The selected sodium silicate solution is a mixture of solutions with different Baumé degrees and moduli. Baumé degree and modulus are important properties of sodium silicate solutions. The higher the modulus, the higher the silicon content and the stronger the adhesive force, but it will also be more difficult to dissolve in water. Therefore, it is important to select an appropriate range of moduli. Baumé degree indicates the concentration of the solution; the higher the concentration, the more sodium silicate and silicate it contains. By mixing sodium silicate solutions with different Baumé degrees and moduli, the viscosity of component A can be controlled, resulting in a final anchoring agent with good solubility and adhesive force.

[0011] Furthermore, in component A, the catalyst is selected from one or more of the following: a compound of organobismuth catalyst and organozinc catalyst, N,N-dimethylbenzylamine, tetramethyl-1,6-hexanediamine, dimethylaminoethoxyethanol, and tetramethyldipropylenetriamine. The chain extender is selected from one or more of glycerol, isophorone diamine, and allyl propylene diamine; The thixotropic agent is selected from one or more of nano-silica, silane-modified nano-silica, hydrophilic nano-calcium carbonate, and hydrophilic nano-zinc oxide. The polyether polyol is one or two of hydroxyl-terminated polyether-polyester copolyol and polyoxypropylene triamine; The modifier is selected from one or more of γ-glycidyl etheroxypropyltrimethoxysilane, γ-glycidyl etheroxypropyltriethoxysilane, isopropoxytris(dioctylpyrophosphate)titanate, and epoxypropoxytitanate. The mudstone solidifying agent is a hydrophilic functionalized nanomaterial.

[0012] Furthermore, in component A, the hydroxyl-terminated polyether-polyester copolyol is at least one of PCL-PEG-OH, PLA-PEG-OH, and PLGA-PEG-OH.

[0013] Furthermore, in component A, the mudstone solidifying agent is selected from at least one of functionalized silica, p-aminobenzenesulfonic acid modified carbon nanotubes (containing sulfonic acid groups and amino groups), and AP modified carbon nanotubes (containing amino and hydroxyl groups).

[0014] Furthermore, in component B, the isocyanate is selected from one or more of triphenylmethane triisocyanate, trimer isocyanate, diphenylmethane diisocyanate, and isophorone diisocyanate; The plasticizer is selected from one or more of diethylene glycol ethyl ether acetate, diethylene glycol butyl ether acetate, dioctyl phthalate, and tributyl citrate.

[0015] Furthermore, in component B, the carboxyl-containing isocyanate derivative is selected from at least one of HDI-type carboxyl-containing derivatives, IPDI-type carboxyl-containing derivatives, TDI-DMPA derivatives, HDI-TMP-DMPA derivatives, and IPDI-DMPA derivatives.

[0016] A method for preparing a pumpable anchoring agent of the above-mentioned mudstone type specifically includes the following steps: Step S1: Preparation of component A: Weigh each raw material of component A according to the formula, stir at a speed of 300-600 rpm / min for 30-60 minutes, mix evenly, and obtain component A; Step S2: Preparation of Component B: Weigh each raw material of Component B according to the formula, stir at a speed of 100-300 rpm / min for 30-60 minutes, mix evenly, and obtain Component B.

[0017] Furthermore, in step S1, the stirring speed is 450-600 rpm / min; in step S2, the stirring speed is 200-300 rpm / min.

[0018] Anchoring agent application: Before construction, mix component A and component B in a certain proportion (determined according to actual project requirements and anchoring agent performance requirements, usually a volume ratio of component A to component B of 1:1). After stirring evenly, it can be used for anchoring construction in mudstone engineering. This mixture has good pumpability and is convenient for engineering operation.

[0019] An application of a pumpable anchoring agent of the aforementioned mudstone type, wherein the anchoring agent is used in mudstone formation anchoring projects.

[0020] The beneficial effects of this invention are as follows: This invention has a reasonable design and a simple preparation method, and has the following advantages: (1) Significantly improved interfacial bonding strength: By introducing carboxyl-containing isocyanate derivatives, hydroxyl-terminated polyether-polyester copolyols and specific hydrophilic modifiers, the anchoring agent and mudstone surface form a dual effect of "strong chemical bonds (such as CO-Si bonds, ester bonds) + hydrogen bonds", with a bonding strength >3MPa, effectively solving the interfacial peeling problem; (2) The stability of mudstone is greatly enhanced: the introduced hydrophilic functionalized nanomaterials are used as mudstone solidifying agents. Their active groups can react with the surface of mudstone, participate in cross-linking and solidification, and block the interface pores. At the same time, the nanoparticles fill the micro-cracks of mudstone and form a stable complex with clay minerals, which inhibits the swelling and softening of mudstone when it comes into contact with water and improves the durability of the anchoring system. (3) Comprehensive optimization of anchoring performance: The compressive strength of the anchoring agent of this invention reaches more than 35MPa in 1 hour, 55-60MPa in 24 hours, and the anchoring force reaches 210-240kN. Its comprehensive performance is significantly better than that of ordinary anchoring agents. (4) Good construction convenience: By adding thixotropic agents and optimizing the ratio, the anchoring agent has excellent thixotropy and pumpability (viscosity of component A is 200-300 mPa at 25℃). s, Component B viscosity 100-200 mPa (s), with good pumpability, facilitates large-scale and efficient anchoring construction in mudstone engineering, reduces construction difficulty and labor intensity, and is very convenient for engineering applications. Attached Figure Description

[0021] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0022] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0023] Figure 1 shows photographs of the contact angles of the anchoring agents prepared in Example 1(a) and Comparative Example 4(b) on the mudstone surface; Figure 2 Here is a SEM image of the mudstone anchoring agent prepared in Example 1; Figure 3 These are SEM images of the anchoring interface between the anchoring agent and mudstone prepared in Example 1(a) and Comparative Example 4(b). Detailed Implementation

[0024] It should be noted that the following detailed descriptions are illustrative and intended to provide further explanation of this application. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains.

[0025] It should be noted that the terminology used herein is for the purpose of describing particular implementations only and is not intended to limit the exemplary implementations according to this application. As used herein, the singular form includes the plural form unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this description, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0026] The technical solution of the present invention will be clearly and completely described below with reference to the embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. 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.

[0027] In a first aspect, the present invention provides a mudstone-type pumpable anchoring agent, which is composed of component A and component B, and when used, component A and component B are mixed in a volume ratio of 1:1. Component A, by mass, includes: 50-80 parts of first sodium silicate solution, 20-50 parts of second sodium silicate solution, 0.3 parts of catalyst, 5-10 parts of chain extender, 3-5 parts of thixotropic agent, 2-4 parts of polyether polyol, 2-4 parts of modifier, and 2-4 parts of mudstone solidifying agent. Component B, by mass, includes: 90-110 parts of isocyanate substances, 10-30 parts of plasticizer, and 3-8 parts of carboxyl-containing isocyanate derivatives.

[0028] In component A, the first sodium silicate solution is a sodium silicate solution with a modulus of 2.1 to 2.8 and a Baume degree of 45 to 51°Bé; the second sodium silicate solution is a sodium silicate solution with a modulus of 2.8 to 3.5 and a Baume degree of 40 to 45°Bé.

[0029] In component A, the catalyst is selected from one or more of the following: a compound of organobismuth catalyst DY-20 and organozinc catalyst DY-5350 (compound ratio 1:10 to 10:1), N,N-dimethylbenzylamine, tetramethyl-1,6-hexanediamine, dimethylaminoethoxyethanol, and tetramethyldipropylenetriamine; the chain extender is selected from one or more of glycerol, isophorone diamine, and methylallylpropanediamine; the thixotropic agent is selected from one or more of the following: nano-silica, silane-modified nano-silica, hydrophilic nano-calcium carbonate, and hydrophilic nano-zinc oxide; the polyether polyol is one or two of the following: hydroxyl-terminated polyether-polyester copolyol and polyoxypropylene triamine; the modifier is selected from one or more of the following: γ-glycidyl etheroxypropyltrimethoxysilane, γ-glycidyl etheroxypropyltriethoxysilane, isopropoxytris(dioctylpyrophosphate)titanate, and epoxypropoxytitanate; and the mudstone solidifying agent is a hydrophilic functionalized nanomaterial.

[0030] In component A, the hydroxyl-terminated polyether-polyester copolyol is at least one of PCL-PEG-OH, PLA-PEG-OH, and PLGA-PEG-OH.

[0031] In component A, the mudstone solidifying agent is selected from at least one of p-aminobenzenesulfonic acid modified carbon nanotubes, AP modified carbon nanotubes, and functionalized silica.

[0032] In component B, the isocyanate is selected from one or more of triphenylmethane triisocyanate, trimer isocyanate, diphenylmethane diisocyanate, and isophorone diisocyanate.

[0033] In component B, the plasticizer is selected from one or more of diethylene glycol ethyl ether acetate, diethylene glycol butyl ether acetate, dioctyl phthalate, and tributyl citrate.

[0034] In component B, the carboxyl-containing isocyanate derivative is selected from at least one of HDI-type carboxyl-containing derivatives, IPDI-type carboxyl-containing derivatives, TDI-DMPA derivatives, HDI-TMP-DMPA derivatives, and IPDI-DMPA derivatives.

[0035] The roles of each component in Component A are as follows: Sodium silicate solution participates in the curing reaction of the anchoring agent, improving its strength and stability; the catalyst accelerates the curing reaction rate and controls the curing time; the chain extender increases the length of the polymer chain, improving the mechanical properties of the anchoring agent, such as compressive strength; the thixotropic agent imparts good thixotropic properties to the anchoring agent, facilitating pumping during construction and preventing flow during standing, thus ensuring construction quality; polyether polyol, as an important component of the soft segment of the anchoring agent, affects its elasticity and toughness through its structure and properties; the modifier modifies the anchoring agent, enhancing its interfacial affinity with mudstone; the amino groups contained in the mudstone curing agent react with the hydroxyl groups on the mudstone surface, strengthening the rock affinity of the anchoring agent, while also participating in the cross-linking curing reaction of the anchoring agent, blocking interfacial pores, and reducing water penetration; as a nanomaterial, the mudstone curing agent fills micro-cracks in mudstone, forming a stable complex with clay minerals in the mudstone, inhibiting clay swelling upon contact with water.

[0036] The roles of each component in Component B are as follows: Isocyanates, as the main components of the hard segment of the anchoring agent, react with hydroxyl groups and other groups in Component A to form a polymer network structure, which determines the hardness and strength of the anchoring agent. Among them, carboxyl-containing isocyanate derivatives can undergo esterification reactions with hydroxyl groups on the mudstone surface, further enhancing intermolecular forces. At the same time, the hydrophilicity of the carboxyl groups can improve the wettability of polyurethane and mudstone (the contact angle decreases from 70-80° in ordinary polyurethane to 30-40°, and the wettability is improved by more than 50%). Plasticizers can increase the plasticity and flexibility of the anchoring agent, reduce its brittleness after curing, and improve its impact resistance.

[0037] Secondly, the present invention also provides a method for preparing the above-mentioned mud-loving rock type pumpable anchoring agent, specifically including the following steps: Step S1: Preparation of component A: Weigh each raw material of component A according to the formula, stir at a speed of 300-600 rpm / min for 30-60 minutes, mix evenly, and obtain component A; Step S2: Preparation of Component B: Weigh each raw material of Component B according to the formula, stir at a speed of 100-300 rpm / min for 30-60 minutes, mix evenly, and obtain Component B.

[0038] Preferably, in step S1, the stirring speed is 450-600 rpm / min; in step S2, the stirring speed is 200-300 rpm / min.

[0039] Thirdly, the present invention also provides an application of the above-mentioned mudstone-type pumpable anchoring agent, which is used in mudstone formation anchoring projects.

[0040] The anchoring mechanism of the mud-loving rock-type pumpable anchoring agent of the present invention is mainly reflected in the following three synergistic effects: (1) Chemical bonding and hydrogen bonding enhance interfacial bonding By introducing carboxyl-containing isocyanate derivatives and hydroxyl-terminated polyether-polyester copolyols, the active groups such as carboxyl and hydroxyl groups in the anchoring agent undergo esterification and condensation reactions with the hydroxyl groups on the mudstone surface to form stable chemical bonds such as CO-Si bonds and ester bonds. At the same time, the ether bonds in the polyether polyol form a hydrogen bond network with the mudstone surface, achieving a dual effect of "chemical bonds + hydrogen bonds" and significantly improving the interfacial bonding strength.

[0041] (2) Nanomaterial filling and mudstone solidification Adding hydrophilic functionalized nanomaterials (such as modified carbon nanotubes and functionalized silica) as mudstone solidifying agents can effectively fill micro-cracks in mudstone with their nano-sized particles, preventing water penetration. The active groups such as amino and sulfonic acid groups on their surface can form stable complexes with clay minerals in mudstone and undergo covalent chemical reactions with isocyanates in component B, which can further bond the anchoring agent tightly to the mudstone, inhibit the mudstone from swelling and softening when exposed to water, and improve the overall stability of the anchoring system.

[0042] (3) Material synergistic optimization and pumpability assurance By adjusting the modulus and Baumé degree of the sodium silicate solution, adding thixotropic agents (such as nano-silica) and plasticizers, the viscosity and thixotropy of the anchoring agent were optimized, enabling it to maintain fluidity during pumping and cure rapidly after standing, thus ensuring ease of construction and anchoring quality.

[0043] Example 1 The mudstone-type pumpable anchoring agent of this embodiment is composed of component A and component B. When using it, component A and component B are mixed evenly in a volume ratio of 1:1 and then transported to the anchoring site using a pumping device. Component A: 50 parts of first sodium silicate solution (modulus 2.1, Baume degree 45°Bé), 50 parts of second sodium silicate solution (modulus 2.8, Baume degree 40°Bé), 0.3 parts of organobismuth catalyst DY-20 and organozinc catalyst DY-5350 (compound ratio 1:10), 5 parts of chain extender glycerol, 3 parts of mudstone solidifying agent p-aminobenzenesulfonic acid modified carbon nanotubes (containing sulfonic acid groups and amino groups), 3 parts of thixotropic agent nano silica, 2 parts of nano silica polyether polyol PCL-PEG-OH, and 2 parts of modifier γ-glycidoxypropyltrimethoxysilane; Component B contains 90 parts of isocyanate (triphenylmethane triisocyanate), 10 parts of plasticizer diethylene glycol ethyl ether acetate, and 3 parts of HDI-type carboxyl derivative.

[0044] The preparation method of the above-mentioned mud-loving rock type pumpable anchoring agent specifically includes the following steps: Step S1: Preparation of component A: Weigh each raw material of component A according to the formula, stir at 300 rpm / min for 60 minutes, mix evenly, and obtain component A; Step S2: Preparation of Component B: Weigh each raw material of Component B according to the ratio, stir at 100 rpm / min for 60 minutes until uniformly mixed, and Component B is obtained.

[0045] Figure 2 This is a SEM image of the mudstone anchoring agent prepared in Example 1. The image shows that the anchoring agent exhibits a uniform and dense microstructure after curing, with no obvious pores or cracks, indicating good internal bonding of the material, which is beneficial to improving its mechanical properties.

[0046] Example 2 The mudstone-type pumpable anchoring agent of this embodiment is composed of component A and component B. When using it, component A and component B are mixed evenly at a volume ratio of 1:1 and then transported to the anchoring site using a pumping device. Component A: 65 parts of first sodium silicate solution (modulus 2.5, Baume degree 48°Bé), 35 parts of second sodium silicate solution (modulus 3.2, Baume degree 43°Bé), 0.3 parts of catalyst (organobismuth catalyst DY-20 and organozinc catalyst DY-5350 in a 1:1 ratio), 7 parts of chain extender isophorone diamine, 4 parts of thixotropic agent silane-modified nano silica, 3 parts of polyether polyol PLA-PEG-OH, 3 parts of modifier isopropoxytris(dioctylpyrophosphoryloxy) titanate, and 3 parts of AP-modified carbon nanotubes. Component B contains 100 parts of isocyanate (trimeric isocyanate), 20 parts of dioctyl phthalate plasticizer, and 5 parts of IPDI-type carboxyl derivative.

[0047] The preparation method of the above-mentioned mud-loving rock type pumpable anchoring agent specifically includes the following steps: Step S1: Preparation of component A: Weigh each raw material of component A according to the ratio, stir at 450 rpm / min for 45 minutes until uniformly mixed, and component A is obtained. Step S2: Preparation of Component B: Weigh each raw material of Component B according to the ratio, stir at 200 rpm / min for 45 minutes until uniformly mixed, and Component B is obtained.

[0048] Example 3 The mudstone-type pumpable anchoring agent of this embodiment is composed of component A and component B. When using it, component A and component B are mixed evenly at a volume ratio of 1:1 and then transported to the anchoring site using a pumping device. Component A: 80 parts of first sodium silicate solution (modulus 2.8, Baume degree 51°Bé), 20 parts of second sodium silicate solution (modulus 3.5, Baume degree 45°Bé), 0.3 parts of catalyst (organobismuth catalyst DY-20 and organozinc catalyst DY-5350 in a 10:1 ratio), 10 parts of chain extender methylallylpropanediamine, 5 parts of thixotropic agent hydrophilic nano-calcium carbonate, 4 parts of polyether polyol PLGA-PEG-OH, 4 parts of modifier γ-glycidyl etheroxypropyltriethoxysilane, and 4 parts of mudstone solidifying agent AP modified carbon nanotubes; Component B contains 110 parts of isocyanate (diphenylmethane diisocyanate), 30 parts of plasticizer tributyl citrate, and 8 parts of IPDI-DMPA derivative.

[0049] The preparation method of the above-mentioned mud-loving rock type pumpable anchoring agent specifically includes the following steps: Step S1: Preparation of component A: Weigh each raw material of component A according to the formula, stir at 600 rpm / min for 30 minutes, mix evenly, and obtain component A; Step S2: Preparation of Component B: Weigh each raw material of Component B according to the ratio, stir at 300 rpm / min for 30 minutes until uniformly mixed, and Component B is obtained.

[0050] Comparative Example 1 The mudstone-type pumpable anchoring agent in this comparative example consists of component A and component B. When using it, component A and component B are mixed evenly at a volume ratio of 1:1 and then transported to the anchoring site using a pumping device. Component A: 50 parts of first sodium silicate solution (modulus 2.1, Baume degree 45°Bé), 50 parts of second sodium silicate solution (modulus 2.8, Baume degree 40°Bé), 0.3 parts of organobismuth catalyst DY-20 and organozinc catalyst DY-5350 (compound ratio 1:10), 5 parts of chain extender glycerol, 3 parts of mudstone solidifying agent p-aminobenzenesulfonic acid modified carbon nanotubes (containing sulfonic acid groups and amino groups), 3 parts of thixotropic agent nano silica, and 2 parts of nano silica polyether polyol PCL-PEG-OH; Component B contains 90 parts of isocyanate (triphenylmethane triisocyanate), 10 parts of plasticizer diethylene glycol ethyl ether acetate, and 3 parts of HDI-type carboxyl derivative.

[0051] The preparation method of the above-mentioned mud-loving rock type pumpable anchoring agent specifically includes the following steps: Step S1: Preparation of component A: Weigh each raw material of component A according to the formula, stir at 300 rpm / min for 60 minutes, mix evenly, and obtain component A; Step S2: Preparation of Component B: Weigh each raw material of Component B according to the ratio, stir at 100 rpm / min for 60 minutes until uniformly mixed, and Component B is obtained.

[0052] Comparative Example 2 The mudstone-type pumpable anchoring agent in this comparative example consists of component A and component B. When using it, component A and component B are mixed evenly at a volume ratio of 1:1 and then transported to the anchoring site using a pumping device. Component A: 50 parts of first sodium silicate solution (modulus 2.1, Baume degree 45°Bé), 50 parts of second sodium silicate solution (modulus 2.8, Baume degree 40°Bé), 0.3 parts of organobismuth catalyst DY-20 and organozinc catalyst DY-5350 (combination ratio 1:10), 5 parts of chain extender glycerol, 3 parts of thixotropic agent nano silica, 2 parts of nano silica polyether polyol PCL-PEG-OH, and 2 parts of modifier γ-glycidoxypropyltrimethoxysilane; Component B contains 90 parts of isocyanate (triphenylmethane triisocyanate), 10 parts of plasticizer diethylene glycol ethyl ether acetate, and 3 parts of HDI-type carboxyl derivative.

[0053] The preparation method of the above-mentioned mud-loving rock type pumpable anchoring agent specifically includes the following steps: Step S1: Preparation of component A: Weigh each raw material of component A according to the formula, stir at 300 rpm / min for 60 minutes, mix evenly, and obtain component A; Step S2: Preparation of Component B: Weigh each raw material of Component B according to the ratio, stir at 100 rpm / min for 60 minutes until uniformly mixed, and Component B is obtained.

[0054] Comparative Example 3 The mudstone-type pumpable anchoring agent in this comparative example consists of component A and component B. When using it, component A and component B are mixed evenly at a volume ratio of 1:1 and then transported to the anchoring site using a pumping device. Component A: 50 parts of first sodium silicate solution (modulus 2.1, Baume degree 45°Bé), 50 parts of second sodium silicate solution (modulus 2.8, Baume degree 40°Bé), 0.3 parts of organobismuth catalyst DY-20 and organozinc catalyst DY-5350 (compound ratio 1:10), 5 parts of chain extender glycerol, 3 parts of mudstone solidifying agent p-aminobenzenesulfonic acid modified carbon nanotubes (containing sulfonic acid groups and amino groups), 3 parts of thixotropic agent nano silica, 2 parts of nano silica polyether polyol PCL-PEG-OH, and 2 parts of modifier γ-glycidoxypropyltrimethoxysilane; Component B contains 90 parts of isocyanate (triphenylmethane triisocyanate) and 10 parts of plasticizer diethylene glycol ethyl ether acetate.

[0055] The preparation method of the above-mentioned mud-loving rock type pumpable anchoring agent specifically includes the following steps: Step S1: Preparation of component A: Weigh each raw material of component A according to the formula, stir at 300 rpm / min for 60 minutes, mix evenly, and obtain component A; Step S2: Preparation of Component B: Weigh each raw material of Component B according to the ratio, stir at 100 rpm / min for 60 minutes until uniformly mixed, and Component B is obtained.

[0056] Comparative Example 4 The mudstone-type pumpable anchoring agent of this embodiment is composed of component A and component B. When using it, component A and component B are mixed evenly at a volume ratio of 1:1 and then transported to the anchoring site using a pumping device. Component A: 50 parts of primary sodium silicate solution (modulus 2.1, Baume degree 45°Bé), 50 parts of secondary sodium silicate solution (modulus 2.8, Baume degree 40°Bé), 0.3 parts of organobismuth catalyst DY-20 and organozinc catalyst DY-5350 (compound ratio 1:10), 5 parts of chain extender glycerol, 3 parts of thixotropic agent nano silica, and 2 parts of nano silica polyether polyol PCL-PEG-OH; Component B contains 90 parts of isocyanate (triphenylmethane triisocyanate) and 10 parts of plasticizer diethylene glycol ethyl ether acetate.

[0057] The preparation method of the above-mentioned mud-loving rock type pumpable anchoring agent specifically includes the following steps: Step S1: Preparation of component A: Weigh each raw material of component A according to the formula, stir at 300 rpm / min for 60 minutes, mix evenly, and obtain component A; Step S2: Preparation of Component B: Weigh each raw material of Component B according to the ratio, stir at 100 rpm / min for 60 minutes until uniformly mixed, and Component B is obtained.

[0058] Figure 1 This is a comparison diagram of the contact angles of the mudstone anchoring agent prepared in Example 1 and the polyurethane anchoring agent in Comparative Example 4 on the mudstone surface, where a represents the mudstone anchoring agent prepared in Example 1 and b represents the anchoring agent prepared in Comparative Example 4. Figure 1As shown, the mudstone anchoring agent prepared in Example 1 has a contact angle of 32.2° on the mudstone surface, exhibiting good hydrophilicity and wettability, which is beneficial for the spreading and penetration of the anchoring agent on the mudstone surface. In contrast, the anchoring agent in Comparative Example 4 has a contact angle of 80.7°, indicating poor affinity with mudstone and a tendency to peel off at the interface. The contact angle of the anchoring agent clearly demonstrates that the present invention significantly improves the wettability of the anchoring agent on mudstone by introducing hydrophilic components.

[0059] Figure 3 These are SEM images of the anchoring interface between the anchoring agent and mudstone obtained in Example 1(a) and Comparative Example 4(b). Figure 3 As can be seen, the anchoring agent in Example 1 bonds tightly to the mudstone interface without significant interface detachment. In contrast, the anchoring agent in Comparative Example 4 exhibits obvious gaps and peeling at the mudstone interface, indicating weak interfacial bonding. This clearly demonstrates that the anchoring agent of this invention can achieve tight adhesion to mudstone, significantly improving interfacial bonding.

[0060] Test case The anchoring agents of Examples 1 to 3 and Comparative Examples 1 to 4 were subjected to compressive strength tests, and the results are shown in Table 1.

[0061] Table 1 Test Results

[0062] As shown in Table 1: (1) Compressive strength: Examples 1-3 achieved a strength of over 35 MPa within 1 hour, and further increased to 55-59 MPa after 24 hours, indicating that the anchoring agent of the present invention has excellent early strength and later enhancement ability. In contrast, the lack of key components (modifier, mudstone solidifying agent, carboxyl isocyanate, etc.) in Comparative Examples 1-4 resulted in a significant decrease in strength, especially Comparative Example 4 (lacking all three types of functional components) had the lowest strength, indicating that each component has a synergistic enhancement effect in improving mechanical properties.

[0063] (2) Interfacial bonding strength: The bonding strength of Examples 1-3 reached 3.2-3.6 MPa, which is higher than that of Comparative Example 4 (2.2 MPa), indicating that the present invention effectively improves the interfacial bonding strength through the dual action of "chemical bond + hydrogen bond" and nanofilling. The bonding strength of Comparative Example 2 (without mudstone solidifier) ​​and Comparative Example 3 (without carboxyl isocyanate) was 3.0 MPa and 2.8 MPa, respectively. Although it was better than Comparative Example 4, it was still significantly lower than that of Examples 4, proving that mudstone solidifier and carboxyl isocyanate are the key components for improving interfacial bonding.

[0064] (3) Anchoring force: The anchoring forces of all examples exceeded 235kN, with the highest reaching 244kN, which is 33% higher than that of Comparative Example 4 (183kN), indicating that the overall anchoring system of the present invention has a significant advantage in bearing capacity. The anchoring forces of Comparative Example 1 (without modifier) ​​and Comparative Example 3 (without carboxyl isocyanate) were 217kN and 210kN, respectively, further verifying the direct influence of the interface strengthening component on the overall anchoring force.

[0065] Application Example 1: Application of Anchoring Agent in Mudstone Tunnel Support Engineering Application scenario: Support project for mudstone roadway in a coal mine. The surrounding rock of the roadway is soft mudstone, which is easily softened when exposed to water. Traditional anchoring agents have insufficient anchoring force and are prone to failure.

[0066] Construction steps: First, drill anchor holes with a diameter of Φ28 mm at the designed spacing on the tunnel wall; second, insert hollow grouting anchor cables with a diameter of 22 mm into the holes; finally, use a two-component grouting pump to pump components A and B at a volume ratio of 1:1.

[0067] Effect evaluation: (1) The pumping construction is highly adaptable, and can achieve long-distance and large-flow grouting with low labor intensity and a 50% improvement in overall construction efficiency; (2) The anchoring agent has good wettability on the mudstone surface, no flow phenomenon, and is tightly bonded to the surrounding rock; (3) The pull-out force reaches 236kN in 24 hours, far exceeding the industry standard (≥200kN), and has good long-term stability, maintaining more than 95% anchoring force after 28 days; (4) The surrounding rock control effect is excellent, and the deformation of the roadway roof and sides is reduced by about 57%, effectively inhibiting the continuous deformation caused by the softening of mudstone when it encounters water.

[0068] In summary, each functional component (modifier, mudstone solidifier, and carboxyl isocyanate) mutually promotes the improvement of strength, adhesion, and anchoring force, and none can be omitted. The anchoring agent prepared by this invention significantly inhibits mudstone softening and interfacial delamination through chemical bonding and nanofilling, thereby improving long-term anchoring stability. Furthermore, the performance indicators of the examples are significantly better than those of the comparative examples, with a reasonable data gradient, fully verifying the scientific validity and practicality of the formulation of this invention.

[0069] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A pumpable anchoring agent for mudstone-loving rock, characterized in that: It consists of component A and component B, which are mixed in a volume ratio of 1:1 when used. The A component, by mass, comprises: 50-80 parts of a first sodium silicate solution, 20-50 parts of a second sodium silicate solution, 0.3 parts of a catalyst, 5-10 parts of a chain extender, 3-5 parts of a thixotropic agent, 2-4 parts of a polyether polyol, 2-4 parts of a modifier, and 2-4 parts of a mudstone solidifying agent. Component B, by mass, comprises: 90-110 parts of isocyanate, 10-30 parts of plasticizer, and 3-8 parts of carboxyl-containing isocyanate derivative.

2. The mudstone-type pumpable anchoring agent according to claim 1, characterized in that: In component A, the first sodium silicate solution is a sodium silicate solution with a modulus of 2.1 to 2.8 and a Baume degree of 45 to 51°Bé. The second sodium silicate solution is a sodium silicate solution with a modulus of 2.8 to 3.5 and a Baume degree of 40 to 45°Bé.

3. The mudstone-type pumpable anchoring agent according to claim 1, characterized in that: In component A, the catalyst is selected from one or more of the following: a complex of organobismuth catalyst and organozinc catalyst, N,N-dimethylbenzylamine, tetramethyl-1,6-hexanediamine, dimethylaminoethoxyethanol, and tetramethyldipropylenetriamine. The chain extender is selected from one or more of glycerol, isophorone diamine, and allyl propylene diamine; The thixotropic agent is selected from one or more of nano-silica, silane-modified nano-silica, hydrophilic nano-calcium carbonate, and hydrophilic nano-zinc oxide. The polyether polyol is one or two of hydroxyl-terminated polyether-polyester copolyol and polyoxypropylene triamine; The modifier is selected from one or more of γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropyltriethoxysilane, isopropoxytris(dioctylpyrophosphate)titanate, and epoxypropoxytitanate. The mudstone solidifying agent is a hydrophilic functionalized nanomaterial.

4. The mudstone-type pumpable anchoring agent according to claim 3, characterized in that: In component A, the hydroxyl-terminated polyether-polyester copolyol is at least one of PCL-PEG-OH, PLA-PEG-OH, and PLGA-PEG-OH.

5. The mudstone-type pumpable anchoring agent according to claim 3, characterized in that: In component A, the mudstone solidifying agent is selected from at least one of p-aminobenzenesulfonic acid modified carbon nanotubes, AP modified carbon nanotubes, and functionalized silica.

6. The mudstone-type pumpable anchoring agent according to claim 1, characterized in that: In component B, the isocyanate is selected from one or more of triphenylmethane triisocyanate, trimer isocyanate, diphenylmethane diisocyanate, and isophorone diisocyanate; The plasticizer is selected from one or more of diethylene glycol ethyl ether acetate, diethylene glycol butyl ether acetate, dioctyl phthalate, and tributyl citrate.

7. The mudstone-type pumpable anchoring agent according to claim 1, characterized in that: In component B, the carboxyl-containing isocyanate derivative is selected from at least one of HDI-type carboxyl-containing derivatives, IPDI-type carboxyl-containing derivatives, TDI-DMPA derivatives, HDI-TMP-DMPA derivatives, and IPDI-DMPA derivatives.

8. A method for preparing a mudstone-type pumpable anchoring agent as described in any one of claims 1 to 7, characterized in that: Specifically, the steps include the following: Step S1: Preparation of component A: Weigh each raw material of component A according to the formula, stir at a speed of 300-600 rpm / min for 30-60 minutes, mix evenly, and obtain component A; Step S2: Preparation of Component B: Weigh each raw material of Component B according to the formula, stir at a speed of 100-300 rpm / min for 30-60 minutes, mix evenly, and obtain Component B.

9. The mudstone-type pumpable anchoring agent according to claim 1, characterized in that: In step S1, the stirring speed is 450-600 rpm / min; in step S2, the stirring speed is 200-300 rpm / min.

10. An application of the mudstone-type pumpable anchoring agent as described in any one of claims 1 to 7, characterized in that: The application of the anchoring agent in anchoring engineering of mudstone formations.

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