Elastic epoxy resin grouting materials, their preparation methods and applications

Abstract

This invention provides an elastic epoxy resin grouting material, its preparation method, and its application. The elastic epoxy resin grouting material comprises a first component and a second component. The first component includes: bisphenol F type epoxy resin, epoxy resin reactive diluent, alcohol-based inactive diluent, reactive phase separation toughening agent, and interface treatment agent. The second component includes: a quaternary Mannich reaction curing agent, a chain extender, a compound curing aid, and an amine moisture stabilizer. The quaternary Mannich reaction curing agent is prepared by a Mannich reaction of cashew nut shell phenol, N-aminoethyl piperazine, paraformaldehyde, and polypropylene glycol diglycidyl ether, and has the structure shown in formula (I): (I) where n is 5~10. The reactive phase separation toughening agent includes any one of carboxyl-terminated butadiene nitrile rubber, amino-terminated butadiene nitrile rubber, and polyethersulfone. The compound curing aid includes a tertiary amine curing agent and an organic acid.

Description

Technical Field

[0001] This invention relates to the field of grouting materials technology, and in particular to an elastic epoxy resin grouting material, its preparation method, and its application. Background Technology

[0002] Concrete structures, especially subway tunnels, highway bridges, and building main structures, commonly incorporate "live joints" such as expansion joints, settlement joints, and seismic joints to cope with structural deformation caused by temperature changes, load differences, and earthquakes. However, these areas also become high-risk zones for water leakage. Particularly in subway tunnels, these live joints are constantly exposed to high-frequency vibrations (10-50Hz) and fluctuating temperature and humidity from train operation, leading to frequent deformation and particularly prominent leakage problems. Currently, the main methods for preventing water leakage in concrete live joints include grouting, sealing, surface treatment, replacement of waterstops, structural reinforcement, and drainage. Among these, grouting is a commonly used method. Epoxy resin grouting materials are widely used for grouting reinforcement of concrete structures due to their excellent durability, mechanical properties, and impermeability.

[0003] However, commonly used epoxy resin grouting materials exhibit rigidity after curing, with low elongation at break and high brittleness. When applied to live joints requiring deformation, they cannot adapt to repeated structural deformation, easily cracking at the joint surface and leading to re-leakage. Summary of the Invention

[0004] In view of this, in order to at least partially solve one of the aforementioned technical problems, the present invention provides an elastic epoxy resin grouting material, its preparation method, and its application.

[0005] According to one embodiment of the present invention, an elastic epoxy resin grouting material is provided, comprising a first component and a second component.

[0006] The first component includes:

[0007] Bisphenol F type epoxy resin, epoxy resin reactive diluent, alcohol-based non-reactive diluent, reactive phase separation toughening agent, interface treatment agent;

[0008] The second component includes:

[0009] Quaternary Mannich reaction curing agent, chain extender, compound curing aid, amine moisture stabilizer

[0010] The quaternary Mannich reaction curing agent is prepared by the Mannich reaction of cashew nut phenol, N-aminoethylpiperazine, paraformaldehyde, and polypropylene glycol diglycidyl ether, and has the structure shown in formula (I):

[0011] (I),

[0012] Where n is 5 to 10,

[0013] Reactive phase separation toughening agents include any one of carboxyl-terminated butadiene-acrylonitrile rubber, amino-terminated butadiene-acrylonitrile rubber, and polyethersulfone;

[0014] Compound curing aids include tertiary amine curing agents and organic acids.

[0015] According to another aspect of the present invention, a method for preparing the above-mentioned elastic epoxy resin grouting material is provided, comprising:

[0016] An epoxy resin reactive diluent and an alcohol-based non-reactive diluent are added sequentially to bisphenol F type epoxy resin. After mixing evenly, a reactive phase separation toughening agent and an interface treatment agent are added. The mixture is heated to 40~50℃ and stirred to obtain the first component.

[0017] Add chain extender, compound curing aid and amine moisture stabilizer to quaternary Mannich reaction curing agent and mix and stir to obtain the second component;

[0018] The first component and the second component are mixed to obtain an elastic epoxy resin grouting material.

[0019] According to another aspect of the present invention, an application of the above-described elastic epoxy resin grouting material in the repair of concrete structures is provided.

[0020] The elastic epoxy resin grouting material provided by this invention introduces flexible long chains and active amine groups into the molecular chain through a quaternary Mannich reaction curing agent, forming a cross-linked network that can be moderately deformed after curing. This endows the material with good elasticity and fatigue resistance, enabling it to adapt to repeated deformation of concrete joints and effectively preventing cracking and leakage. The compounded curing aid lowers the ring-opening reaction barrier of epoxy groups through an acid-base synergistic mechanism, allowing the grouting material to cure rapidly even at low temperatures (-5℃), overcoming the limitations of low-temperature construction. Simultaneously, the interface treatment agent and dilution system work synergistically to enhance the chemical bonding with the damp concrete interface while ensuring low viscosity and high permeability, significantly improving underwater bonding reliability. This grouting material maintains the good strength and durability of epoxy resin while possessing excellent elasticity, low-temperature curing activity, and interface adaptability. It is also environmentally friendly, easy to construct, and suitable for treating concrete joint leakage in harsh conditions such as subway tunnels and high-altitude cold tunnels. Detailed Implementation

[0021] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to specific embodiments.

[0022] The endpoints and any values ​​of the ranges invented in this invention are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically invented in this invention.

[0023] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the invention. The terms “comprising,” “including,” etc., as used herein indicate the presence of the stated features, steps, operations, and / or components, but do not exclude the presence or addition of one or more other features, steps, operations, or components.

[0024] In the process of developing this invention, it was discovered that commonly used epoxy resin grouting materials exhibit rigidity after curing, with low elongation at break and high brittleness. When applied to live joints requiring deformation, they cannot adapt to repeated structural deformation, easily cracking at the bonding surface and leading to re-leakage. Existing technologies have many limitations in addressing this problem: flexible segments (such as polyurethane) introduced to improve elasticity often sacrifice material durability, making them prone to hydrolysis and aging in humid environments; some products using toxic dilution systems such as furfural-acetone have poor environmental performance and are unsuitable for construction in confined spaces; moreover, most materials are not designed for the vibration environment of subways, resulting in insufficient fatigue resistance and a significant decrease in bond strength after vibration; in addition, existing materials cure slowly at low temperatures (-5°C), and some high-viscosity products have poor groutability, making it difficult to meet the construction requirements of cold-weather conditions or micro-cracks.

[0025] To address this issue, this invention proposes an elastic epoxy resin grouting material, its preparation method, and its application. By designing a quaternary curing agent prepared from cashew phenol, N-aminoethylpiperazine, paraformaldehyde, and polypropylene glycol diglycidyl ether via the Mannich reaction, a network structure with both good reactivity and long flexible segments is constructed at the molecular level. This synergistically resolves the inherent contradictions between elasticity and durability, low-temperature curing and strength development, and groutability and bonding reliability. Specifically, through the synergistic effect of this quaternary curing agent with epoxy resin, reactive toughening agents, and compounded low-temperature accelerators, the grouting material maintains the high strength and durability of epoxy resin while achieving excellent elasticity, fatigue resistance, low-temperature curing activity, and adhesion to damp interfaces. This provides a long-term and reliable solution for leak control in concrete joints under harsh environments such as subway tunnels and high-altitude cold tunnels.

[0026] According to one aspect of the present invention, an elastic epoxy resin grouting material is provided, comprising a first component and a second component. The first component comprises: bisphenol F type epoxy resin, epoxy resin reactive diluent, alcohol-based inactive diluent, reactive phase separation toughening agent, and interface treatment agent; the second component comprises: quaternary Mannich reactive curing agent, chain extender, compound curing aid, and amine moisture stabilizer.

[0027] Specifically, the quaternary Mannich reaction curing agent is prepared by the Mannich reaction of cashew nut shell powder, N-aminoethylpiperazine, paraformaldehyde, and polypropylene glycol diglycidyl ether. The reactive phase separation toughening agent includes any one of carboxyl-terminated butadiene-acrylonitrile rubber (CTBN), amino-terminated butadiene-acrylonitrile rubber (ATBN), and polyethersulfone (PES); the compounded curing aid includes tertiary amine curing agents and organic acids.

[0028] The quaternary Mannich reactive curing agent has the structure shown in formula (Ⅰ):

[0029] (I)

[0030] Where n is the number of repeating units in the polypropylene glycol chain segment, and n is 5~10, which is controlled according to the molecular weight of polypropylene glycol diglycidyl ether.

[0031] In the molecular structure of the quaternary Mannich reaction curing agent, cashew phenol provides the benzene rings at both ends of the molecule and the hydrophobic long straight-chain alkyl groups (C) attached to them. 15 H 31 -), can reduce the internal stress of the cured grouting material and improve its elasticity, which is a key structural basis for improving the elongation at break.

[0032] The formaldehyde units provided by paraformaldehyde are used to firmly connect the benzene ring of cashew phenol with the piperazine ring of N-aminoethylpiperazine by covalent bonds, forming a Mannich reaction bridging bond structure, which ensures the integrity of the molecular chain.

[0033] The nitrogen atom (secondary amine) on the piperazine ring at the molecular center has a high electron cloud density and reactivity, and can still effectively attack epoxy groups at low temperatures (-5℃), maintaining an active core with a high curing reaction rate. In addition, the aminoethyl primary amine group (-CH2CH2-NH-) provided at the N-aminoethylpiperazine end can quickly initiate a reaction with epoxy groups, significantly shortening the gel time of the system, especially at low temperatures (-5℃), thereby ensuring construction efficiency and early strength development of the material.

[0034] Polypropylene glycol diglycidyl ether provides a flexible ether chain segment of polypropylene glycol (-O-[CH2CH(CH3)-O)). n(n=5~10), which can further reduce the rigidity of the entire cross-linked network, and work synergistically with long alkyl chains to transform the rigid epoxy network into a tough network that can withstand deformation, thereby improving elasticity and vibration fatigue resistance.

[0035] According to embodiments of the present invention, through the molecular structure design of the quaternary Mannich reactive curing agent and the synergistic effect of components such as reactive phase separation toughening agents and compound curing aids, four functions of "low-temperature curing - underwater bonding - high elasticity - vibration resistance" are achieved.

[0036] This invention selects bisphenol F type epoxy resin, which has a lower viscosity than conventional bisphenol A type epoxy resin. With the same amount of diluent, it is easier to obtain a low-viscosity slurry suitable for grouting micro-cracks. Moreover, the bisphenol F epoxy structure gives the cured product better hydrolysis resistance and flexibility, which helps to improve the long-term durability and crack resistance of the material in humid environments.

[0037] Specifically, the epoxy value of bisphenol F type epoxy resin is 0.51~0.55 eq / 100g.

[0038] Furthermore, the tertiary amine curing agent and organic acid in the compound curing aid can form protonated tertiary amine salts, which reduces the ring-opening activation energy of the epoxy groups in the epoxy resin, accelerates the reaction rate between epoxy groups and amine groups, and enables the grouting material to rapidly gel and completely cure at low temperature (-5℃).

[0039] In addition, the flexible segments provided by polypropylene glycol diglycidyl ether in the quaternary curing agent work synergistically with the reactive phase separation toughening agent to form a microphase separation structure, which absorbs vibration energy and keeps the bond strength reduction rate of the material within 10% after 1 million high-frequency vibrations, significantly improving fatigue resistance.

[0040] Specifically, the reactive phase separation toughening agent can be industrial-grade CTBN (carboxyl-terminated nitrile butadiene rubber) with a carboxyl content of 0.8~1.2 mmol / g.

[0041] Meanwhile, the interface treatment agent forms a strong chemical bond with the concrete substrate through its functional groups, and together with the hydrophobic long chain structure of the special curing agent molecules, it enhances the interfacial adhesion reliability and durability of the material in humid or underwater environments.

[0042] According to embodiments of the present invention, the amine value of the quaternary Mannich reaction curing agent is 480~520 mgKOH / g. If the amine value is too low, the curing reaction will be incomplete, resulting in insufficient mechanical properties; if the amine value is too high, the reaction may be too fast, shortening the workable time, and excessive crosslinking density will impair elasticity. The amine value range of the present invention ensures that the quaternary Mannich reaction curing agent has sufficiently high activity to achieve rapid curing at low temperatures, while avoiding brittleness caused by excessive crosslinking.

[0043] According to an embodiment of the present invention, the raw materials of the quaternary Mannich reaction curing agent, calculated by mass parts, include: 60-80 parts of cashew phenol, 20-40 parts of N-aminoethylpiperazine, 20-30 parts of paraformaldehyde, and 10-30 parts of polypropylene glycol diglycidyl ether.

[0044] In some specific embodiments of the present invention, cashew phenol can be, for example, 60 parts, 65 parts, 70 parts, 75 parts, 80 parts, etc.; N-aminoethylpiperazine can be, for example, 20 parts, 25 parts, 30 parts, 35 parts, 40 parts, etc. This range of parts ensures that the Mannich reaction product has a suitable ratio of long aliphatic hydrocarbon chains and highly reactive amine groups. The long chain structure provided by cashew phenol dominates the intrinsic flexibility and hydrophobic aging resistance of the material, while N-aminoethylpiperazine provides the necessary reactivity and crosslinking density, so that the synthesized curing agent molecule has both good flexibility and reactivity.

[0045] In some specific embodiments of the present invention, paraformaldehyde can be, for example, 20 parts, 22 parts, 24 parts, 26 parts, 28 parts, 30 parts, etc., as a structural unit connecting cashew phenol and amine molecules. This dosage range can ensure that cashew phenol is fully incorporated into the molecular chain to form a stable Mannich bridge structure, thereby effectively exerting its toughening and hydrophobic effects.

[0046] In some specific embodiments of the present invention, polypropylene glycol diglycidyl ether can be, for example, 10 parts, 15 parts, 20 parts, 25 parts, 30 parts, etc. As a chain extender and flexible segment introducer, within the above-mentioned part range, it can effectively adjust the chain length and flexible ether bond content of the quaternary Mannich reaction curing agent molecule, further enhance the flexibility of the molecular chain, and synergistically work with the long-chain structure of cashew phenol to significantly improve the elasticity and fatigue resistance of the final cured product.

[0047] According to embodiments of the present invention, the amine curing agent includes any one of 2,4,6-tris(dimethylaminomethyl)phenol (DMP-30) and benzyldimethylamine; the organic acid includes any one of methanesulfonic acid and p-toluenesulfonic acid; the mass ratio of the amine curing agent to the organic acid is 2:1. This specific ratio of compound curing aid system forms a protonated tertiary amine salt through an acid-base synergistic mechanism, which can effectively reduce the activation energy of the ring-opening reaction of epoxy resin (from the conventional 85 kJ / mol to about 55 kJ / mol), thereby increasing the reaction rate of epoxy groups and amine groups of the material at a low temperature of -5℃ by more than 3 times, thus significantly shortening the gel time and achieving complete curing, breaking through the technical bottleneck of insufficient activity of existing curing agents under low temperature conditions.

[0048] According to embodiments of the present invention, the first component, by weight parts, comprises: 70-80 parts of bisphenol F type epoxy resin, 5-15 parts of epoxy resin reactive diluent, 3-8 parts of alcohol-based inactive diluent, 2-5 parts of reactive phase separation toughening agent, and 0.8-1.5 parts of interface treatment agent. The second component, by weight parts, comprises: 70-85 parts of quaternary Mannich reactive curing agent, 10-20 parts of chain extender, 1.0-2.5 parts of compound curing aid, and 2-5 parts of amine moisture stabilizer.

[0049] In some specific embodiments of the present invention, in the first component, the bisphenol F epoxy resin can be, for example, 70 parts, 72 parts, 74 parts, 76 parts, 78 parts, 80 parts, etc.; the epoxy resin reactive diluent can be, for example, 5 parts, 7 parts, 10 parts, 13 parts, 15 parts, etc.; the alcohol-based inactive diluent can be, for example, 3 parts, 4 parts, 5 parts, 6 parts, 7 parts, 8 parts, etc.; the reactive phase separation toughening agent can be, for example, 2 parts, 3 parts, 4 parts, 5 parts, etc.; and the interface treatment agent can be, for example, 0.8 parts, 1.0 parts, 1.2 parts, 1.5 parts, etc. Through the above proportions and synergy, the construction performance and toughness are optimized while ensuring the mechanical strength and durability of the grouting material. Specifically, a high proportion of bisphenol F epoxy resin ensures a high crosslinking density and bulk strength of the cured network; the combination of reactive and inactive diluents controls the grout viscosity (250~520 mPa). The grouting material achieves a balance between permeability to micro-cracks and performance limitations of a single diluent. Appropriate amounts of reactive toughening agents enhance elongation at break and impact resistance through micro-phase separation structures. Interface treatment agents strengthen interfacial bonding by forming strong chemical bonds, ultimately achieving a unified optimization of the grouting material's strength, elasticity, and groutability.

[0050] In some specific embodiments of the present invention, in the second component, the quaternary Mannich reaction curing agent can be, for example, 70 parts, 72 parts, 75 parts, 78 parts, 80 parts, 83 parts, 85 parts, etc.; the chain extender can be, for example, 10 parts, 12 parts, 14 parts, 16 parts, 18 parts, 20 parts, etc.; the compound curing aid can be, for example, 1.0 part, 1.2 parts, 1.5 parts, 1.8 parts, 2.0 parts, 2.3 parts, 2.5 parts, etc.; and the amine moisture stabilizer can be, for example, 2 parts, 3 parts, 4 parts, 5 parts, etc. The high content of the quaternary Mannich curing agent, as the core curing agent, provides the grouting material with a network structure that combines rigidity and flexibility, as well as low-temperature reactivity; the chain extender further enhances elasticity by introducing flexible ether bonds; the compound curing aid effectively reduces the reaction activation energy, promoting low-temperature curing without affecting storage stability; and the amine moisture stabilizer avoids curing defects by capturing moisture.

[0051] In some specific embodiments of the present invention, the volume ratio of the first component and the second component is 1:1 to 1.5, for example, it can be 1:1, 1:1.2, 1:1.5, etc. This volume ratio range allows the first component and the second component to achieve an equivalent reaction between the epoxy group and the active amine hydrogen after mixing, avoiding incomplete curing or residual small molecules due to improper ratio.

[0052] According to an embodiment of the present invention, the viscosity of the bisphenol F type epoxy resin is 2000~2500 mPa. At 25°C, an appropriate resin viscosity can ensure that the grouting material has sufficient intrinsic strength, and through the synergy of an appropriate amount of diluent, the grouting material slurry has suitable fluidity and penetration ability, thereby maintaining good groutability for micro-cracks in concrete.

[0053] Epoxy resin reactive diluents include any one of butyl glycidyl ether (BGE), benzyl glycidyl ether, and ethylene glycol diglycidyl ether. These diluents contain epoxy groups, which can participate in the curing reaction and become part of the cross-linking network. This allows for the reduction of system viscosity and improvement of pourability while ensuring the density and durability of the cured casting material.

[0054] For example, industrial-grade BGE with a purity ≥99% and a viscosity of 3~5 mPa can be selected. s (25℃).

[0055] Alcohol-based inactive diluents include any one of ethanol, propylene glycol, and dipropylene glycol. These diluents have moderate polarity, good compatibility with epoxy resins, and low toxicity. They can further adjust the slurry viscosity, improve penetration into micro-cracks, and gradually evaporate before curing, without affecting the integrity of the final network structure.

[0056] For example, reagent-grade anhydrous ethanol with a purity of ≥99.5% can be selected.

[0057] Interface treatment agents include any one of silane coupling agents and phthalate coupling agents, whose molecular structure contains both reactive groups that can react with the concrete surface and groups that can bind with organic resins. They form a chemical bridge at the concrete-resin interface, significantly enhancing wet bond strength and durability, and preventing interface delamination caused by moisture intrusion.

[0058] For example, industrial-grade silane coupling agents KH-560 or KH-550 with a purity ≥98% can be selected.

[0059] Chain extenders include any one of polypropylene glycol diglycidyl ether, 1,4-butanediol diglycidyl ether, neopentyl glycol diglycidyl ether, polyethylene glycol diglycidyl ether, and 1,6-hexanediol diglycidyl ether. Multiple epoxy end groups and long flexible chains (such as polyether chains) in the molecule are selected to introduce flexible spacers into the cured network, effectively increasing the interchain spacing and mobility, and improving the elongation at break and toughness of the cured product.

[0060] For example, industrial-grade polypropylene glycol diglycidyl ether with an epoxy value of 0.25~0.30 eq / 100g can be selected.

[0061] Amine moisture stabilizers include any one of ketimine, aldolimine, and polyamide ketimine. They slowly release amine groups in humid / underwater environments, preventing curing failure caused by rapid reaction between moisture and amine groups, thereby improving the water resistance of the cured system and reducing performance degradation after long-term immersion.

[0062] For example, industrial-grade ketimine with a purity of ≥95% can be selected.

[0063] According to embodiments of the present invention, the first component further includes a hydrophobic defoamer, selected from any one of organosilicon-fluorine composite defoamers and modified polyether siloxane defoamers, wherein the first component includes 0.3 to 0.7 parts by mass of the defoamer. During the preparation and construction of grouting materials, air bubbles are easily introduced. Adding an appropriate amount of defoamer can quickly break the bubble film and promote the escape of bubbles, ensuring the mechanical strength, impermeability, and durability of the grouting material.

[0064] According to another aspect of the present invention, a method for preparing the above-mentioned elastic epoxy resin grouting material is provided, comprising: sequentially adding an epoxy resin reactive diluent and an alcohol-based inactive diluent to bisphenol F type epoxy resin, mixing evenly, then adding a reactive phase separation toughening agent and an interface treatment agent, heating to 40~50℃ and mixing and stirring to obtain a first component; adding a chain extender, a compound curing aid, and an amine moisture stabilizer to a quaternary Mannich reactive curing agent and mixing and stirring to obtain a second component; and mixing the first component and the second component to obtain the elastic epoxy resin grouting material.

[0065] For example, the preparation method includes: adding bisphenol F type epoxy resin to a stirred tank, starting stirring at a speed of 300-500 r / min at room temperature, adding epoxy resin reactive diluent and alcohol inactive diluent in sequence, and continuing stirring for 15-20 min until uniformly mixed; then adding reactive phase separation toughening agent and interface treatment agent, heating to 40-50℃ and maintaining stirring for 30-40 min, finally cooling to room temperature, and filtering through a 100-mesh filter to obtain the first component (initial viscosity 250-520 mPa). s). Add the quaternary Mannich reaction curing agent to a four-necked flask (equipped with a stirrer, condenser, and thermometer). While stirring at 200-300 r / min, sequentially add the chain extender, compound curing aid, and amine moisture stabilizer, and continue stirring for 15 min to obtain the second component. Mix the first and second components, and stir for 5-10 min using a high-speed disperser (500-1000 r / min) to obtain the elastic epoxy resin grouting material.

[0066] According to embodiments of the present invention, the preparation method of the present invention ensures that each component is fully dispersed and compatible with the interface through stepwise feeding, temperature-controlled stirring and other processes, so that each component is evenly distributed and reacts, thereby ensuring the stability of the material's high elasticity and strength. Physical mixing reduces the difficulty of on-site operation, and while achieving high material performance, it also takes into account process controllability, batch-to-batch consistency and construction convenience.

[0067] According to an embodiment of the present invention, the preparation method of the quaternary Mannich reaction curing agent includes: uniformly mixing cashew phenol and N-aminoethylpiperazine according to the mass fraction, heating to 40~50°C, adding paraformaldehyde in batches at intervals, carrying out the heat preservation reaction at a reaction temperature of ≤80°C, then adding polypropylene glycol diglycidyl ether, heating to 85~85°C and mixing to obtain the quaternary Mannich reaction curing agent.

[0068] According to an embodiment of the present invention, the synergistic reaction principle of the quaternary special curing agent is as follows: paraformaldehyde first reacts with the primary amine of N-aminoethylpiperazine to form an imine intermediate, and then undergoes a Mannich reaction with the ortho-hydrogen of the phenolic hydroxyl group of cashew phenol. Simultaneously, the epoxy group of polypropylene glycol diglycidyl ether ring-opens with the secondary amine of piperazine, forming a composite molecular structure of "amine-terminated - long alkyl chain - flexible ether bond". Among them, the long alkyl chain (from cashew phenol) and the flexible ether bond (from polypropylene glycol diglycidyl ether) synergistically endow the molecular chain with flexibility, forming a flexible network after curing, ensuring good elongation at break of the grouting material; the active amine group (from N-aminoethylpiperazine) can still react rapidly with epoxy resin at low temperature (-5℃), solving the problem of insufficient low-temperature activity of the curing agent; and the stable -CH2-N- bond formed by the Mannich reaction takes into account both elasticity and durability, ensuring that the strength of the grouting material does not decrease under vibration.

[0069] According to another aspect of the present invention, an application of the above-described elastic epoxy resin grouting material in the repair of concrete structures is provided.

[0070] The elastic epoxy resin grouting material of this invention effectively solves the problems of insufficient adaptability of traditional rigid epoxy materials in concrete joint deformation, low-temperature environments (-5℃), and damp interfaces. Its excellent elasticity and fatigue resistance can adapt to repeated expansion and contraction and vibration of concrete joints, avoiding re-leakage caused by deformation; its excellent low-temperature curing performance ensures normal construction and reliability in cold seasons or regions; furthermore, its adhesion to damp and underwater conditions ensures long-term water-stopping effects under leakage conditions. Therefore, its application in concrete structure repair can significantly improve the durability and reliability of concrete joint treatment.

[0071] Grouting materials are used in the repair of concrete structures, and are especially suitable for long-term repairs under harsh conditions such as subway tunnels, water-bearing tunnels in cold regions, expansion joints of highway bridges, and building structures.

[0072] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to specific embodiments. Unless otherwise specified, specific techniques or conditions in the embodiments are conventional methods and can be performed according to the techniques or conditions described in the literature in this field or according to the product instructions. It should be noted that the methods provided by this invention are conventional methods unless otherwise specified, and the reactants and reagents can be obtained commercially through these channels unless otherwise specified.

[0073] Example 1

[0074] This embodiment provides an elastic epoxy resin grouting material 1.

[0075] The elastic epoxy resin grouting material 1 includes a first component and a second component. The first component includes: 80 parts of bisphenol F type epoxy resin, 10 parts of butyl glycidyl ether (BGE), 5 parts of anhydrous ethanol, 3 parts of carboxyl-terminated nitrile rubber (CTBN), 1.2 parts of silane coupling agent KH-560, and 0.5 parts of organosilicon-fluorine composite defoamer.

[0076] The second component comprises: 75 parts of a quaternary Mannich reaction curing agent, 20 parts of polypropylene glycol diglycidyl ether, 1.5 parts of a compound curing aid (2,4,6-tris(dimethylaminomethyl)phenol and methanesulfonic acid in a mass ratio of 2:1), and 3 parts of ketimine. The raw materials for the quaternary Mannich reaction curing agent include: 70 parts of cashew nut shell powder, 30 parts of N-aminoethylpiperazine, 25 parts of paraformaldehyde, and 20 parts of polypropylene glycol diglycidyl ether.

[0077] The specific preparation method of elastic epoxy resin grouting material 1 is as follows.

[0078] (1) Preparation of the first component:

[0079] According to the mass fraction, add bisphenol F type epoxy resin to a 1000mL stirred tank and stir at 300 r / min at room temperature; add BGE and anhydrous ethanol in sequence and continue stirring for 15min until the mixture is uniform; then add CTBN, KH-560 and organosilicon-fluorine composite defoamer, heat to 40℃ and stir for 30min; finally cool to room temperature and filter through a 100-mesh filter to obtain the first component.

[0080] (2) Preparation of the second component:

[0081] According to the mass fractions, cashew phenol and N-aminoethylpiperazine were added to a 2000mL four-necked flask (equipped with a stirrer, condenser and thermometer), and stirred at 200 r / min; the temperature was slowly raised to 50℃ through an oil bath, and paraformaldehyde was added in batches of 5 parts each time, with an interval of 5 min, and the reaction temperature was controlled not to exceed 80℃. After the addition was completed, the reaction was kept at the temperature for 30 min; then polypropylene glycol diglycidyl ether was added, the temperature was raised to 85℃ and the reaction was continued for 3 h. After the reaction was completed, the temperature was cooled to below 40℃, and the compound curing agent and ketimine were added, and the mixture was stirred for 15 min to obtain the second component.

[0082] (3) Preparation of grouting material: The first component and the second component are mixed at a volume ratio of 1:1 and stirred for 10 min at a speed of 800 r / min using a high-speed disperser to obtain elastic epoxy resin grouting material 1.

[0083] Example 2

[0084] This embodiment provides an elastic epoxy resin grouting material 2.

[0085] The elastic epoxy resin grouting material 2 includes a first component and a second component. The first component includes: 75 parts of bisphenol F type epoxy resin, 15 parts of BGE, 3 parts of anhydrous ethanol, 3 parts of carboxyl-terminated butadiene nitrile rubber (CTBN), 1.5 parts of silane coupling agent KH-560, and 0.5 parts of organosilicon-fluorine composite defoamer.

[0086] The second component comprises: 75 parts of a quaternary Mannich reaction curing agent, 20 parts of polypropylene glycol diglycidyl ether, 2.5 parts of a compound curing aid (2,4,6-tris(dimethylaminomethyl)phenol and methanesulfonic acid in a mass ratio of 2:1), and 5 parts of ketoimine. The raw materials for the quaternary Mannich reaction curing agent include: 70 parts of cashew nut shell powder, 30 parts of N-aminoethylpiperazine, 25 parts of paraformaldehyde, and 20 parts of polypropylene glycol diglycidyl ether.

[0087] The preparation method of elastic epoxy resin grouting material 2 is the same as that in Example 1.

[0088] Example 3

[0089] This embodiment provides an elastic epoxy resin grouting material 3.

[0090] The elastic epoxy resin grouting material 3 includes a first component and a second component. The first component includes: 85 parts of bisphenol F type epoxy resin, 8 parts of BGE, 5 parts of anhydrous ethanol, 4 parts of carboxyl-terminated nitrile butadiene rubber (CTBN), 1.0 part of silane coupling agent KH-560, and 0.5 parts of organosilicon-fluorine composite defoamer.

[0091] The second component comprises: 85 parts of a quaternary Mannich reaction curing agent, 10 parts of polypropylene glycol diglycidyl ether, 1.0 part of a compound curing aid (2,4,6-tris(dimethylaminomethyl)phenol and methanesulfonic acid in a mass ratio of 2:1), and 2 parts of ketoimine. The raw materials for the quaternary Mannich reaction curing agent include: 70 parts of cashew nut shell powder, 30 parts of N-aminoethylpiperazine, 25 parts of paraformaldehyde, and 20 parts of polypropylene glycol diglycidyl ether.

[0092] The preparation method of elastic epoxy resin grouting material 3 is the same as that in Example 1.

[0093] Comparative Example 1

[0094] This embodiment provides an epoxy resin grouting material 4.

[0095] The epoxy resin grouting material 4 comprises a first component and a second component. The first component includes 80 parts of E-51 epoxy resin, 10 parts of benzyl glycidyl ether, and 10 parts of allyl glycidyl ether (AGE). The second component includes 50 parts of polyether amine D400 and 50 parts of highly active modified amine.

[0096] The first component and the second component are mixed at a mass ratio of 2:1 to obtain epoxy resin grouting material 4.

[0097] Comparative Example 2

[0098] This embodiment provides an epoxy resin grouting material 5.

[0099] The epoxy resin grouting material 5 includes a first component and a second component. The first component includes: 80 parts of bisphenol A type epoxy resin, 8 parts of BGE, 5 parts of anhydrous ethanol, 3 parts of CTBN, 1.2 parts of silane coupling agent KH-560, and 0.5 parts of organosilicon-fluorine composite defoamer.

[0100] The second component comprises: 80 parts of a quaternary Mannich reaction curing agent, 15 parts of polypropylene glycol diglycidyl ether, 1.5 parts of a compound curing aid (2,4,6-tris(dimethylaminomethyl)phenol and methanesulfonic acid in a mass ratio of 2:1), and 3 parts of ketimine. The raw materials for the quaternary Mannich reaction curing agent include: 70 parts of cashew nut shell powder, 30 parts of N-aminoethylpiperazine, 25 parts of paraformaldehyde, and 20 parts of polypropylene glycol diglycidyl ether.

[0101] The preparation method of epoxy resin grouting material 5 is the same as that in Example 1.

[0102] The grouting materials in Examples 1-3 and Comparative Examples 1-2 were subjected to performance tests. The test items, standards and results are shown in Table 1.

[0103] Table 1

[0104]

[0105] As shown in Table 1, the elastic epoxy resin grouting material provided in the embodiments of the present invention is superior to the comparative example in terms of key performance.

[0106] Regarding workability, the initial viscosity of the examples was significantly lower than that of the comparative examples, indicating that the use of bisphenol F epoxy resin combined with a diluent system (BGE, ethanol) in this invention can effectively reduce viscosity, ensuring the grout's injectability and good penetration into micro-cracks. Especially at -5°C, the gel time of Example 2 was only 68 minutes, while that of Comparative Example 1 was as long as 450 minutes, making it impossible to apply. This demonstrates that the compound curing aid and the quaternary Mannich reaction curing agent of this invention work synergistically to solve the problem of low-temperature curing.

[0107] In terms of mechanical properties, the embodiments exhibit good bonding strength and elasticity. Specifically, the wet bonding strength of Embodiment 3 reaches 3.8 MPa, and the underwater bonding strength reaches 3.3 MPa, which is much higher than that of Comparative Example 1 (3.0 MPa / 1.8 MPa). Meanwhile, the elongation at break of Embodiment 1 is as high as 135%, which is much higher than that of Comparative Example 1 (12%), indicating that the flexible network formed by the curing of the grouting material in the embodiments significantly improves the material's deformation adaptability.

[0108] In the vibration fatigue performance test, the strength reduction rate of the examples was ≤10% after 1 million vibrations. For example, the strength reduction of Example 3 was only 6.5%, while that of Comparative Example 1 was 31% and leakage occurred, and that of Comparative Example 2 was 26.1%. This verifies the durability advantage of the grouting material of this application in long-term vibration environment.

[0109] The elastic epoxy resin grouting material prepared by this invention has at least the following beneficial effects.

[0110] (1) It can adapt to vibration joints in subway tunnels and solve leakage problems: Through the synergistic effect of the flexible chain segment of the quaternary Mannich reactive curing agent and the reactive phase separation toughening agent, a micro-phase separation structure is formed, which makes the elongation at break of the grouting material ≥130%, the elastic recovery rate ≥75%, and the bonding strength decreases by ≤10% after 1 million high-frequency vibrations. It can withstand 1000 cycles of displacement of 5mm joints without cracking, avoiding the problem of "curing brittle cracking - repeated leakage" of traditional materials. The service life of water-stopping joints in subway tunnels is extended from 1~2 years to ≥10 years.

[0111] (2) Breaking through the construction bottleneck in high-altitude and cold environments such as water-bearing tunnels: The elastic epoxy resin grouting material of this invention has excellent low-temperature curing activity: the gel time at -5℃ is 68~85min and it can be completely cured within 24h, solving the problem of low-temperature curing failure of common grouting materials, and is suitable for construction in high-altitude and cold regions such as the Qinghai-Tibet Plateau; good underwater / wet bonding: wet bonding strength ≥3.5MPa, underwater bonding strength ≥3.0MPa, and the strength decreases by ≤10% after long-term immersion for 30 days, meeting the seepage prevention requirements of construction environments such as water-bearing tunnels and wet cracks.

[0112] (3) The grouting material is environmentally friendly, low in toxicity, easy to construct, and low in application cost: It adopts a low-toxicity dilution system of "epoxy resin active diluent - alcohol non-active diluent", the material half lethal dose (LD50) is ≥2000mg / kg and has no irritating odor, which is suitable for construction in enclosed spaces such as subway tunnels; the volume ratio of the first component and the second component of the grouting material is 1:1~1.5, the working time is 30~90min, no precise weighing is required, which is suitable for subway night construction and long window period requirements in cold regions, and the construction efficiency can be improved by about 30%.

[0113] (4) Multi-scenario adaptation and expansion of application scope: In addition to the treatment of water leakage in subway tunnel joints, it can also be widely used in high-altitude and cold water-bearing tunnels, highway bridge deformation joints, building settlement joints and other scenarios, realizing "one material, multi-scenario adaptation", which greatly reduces the cost of engineering material selection.

[0114] (5) Good long-term durability and reduced operation and maintenance expenses: Based on the synergistic effect of bisphenol F epoxy resin and quaternary Mannich reaction curing agent, the hydrolysis resistance and anti-aging performance of grouting materials are improved, so that the performance degradation of grouting materials is ≤15% in 10 years under humid, vibration and low temperature environment (-5℃). The annual operation and maintenance cost of a single 10km subway tunnel can be reduced from RMB3 million to RMB5 million to RMB500,000 to RMB1 million. The cumulative operation and maintenance cost can be reduced by RMB20 million to RMB40 million over 10 years. The frequency of tunnel maintenance in high-altitude and cold regions can be reduced from twice a year to once every 8 years, which significantly reduces the pressure of project operation and maintenance.

[0115] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above descriptions are merely specific embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. An elastic epoxy resin grouting material, comprising a first component and a second component, characterized in that, The first component includes: Bisphenol F type epoxy resin, epoxy resin reactive diluent, alcohol-based non-reactive diluent, reactive phase separation toughening agent, interface treatment agent; The second component includes: Quaternary Mannich reaction curing agent, chain extender, compound curing aid, amine moisture stabilizer The quaternary Mannich reaction curing agent is prepared by the Mannich reaction of cashew nut phenol, N-aminoethylpiperazine, paraformaldehyde, and polypropylene glycol diglycidyl ether, and has the structure shown in formula (I): （Ⅰ） Where n is 5 to 10, Reactive phase separation toughening agents include any one of carboxyl-terminated butadiene-acrylonitrile rubber, amino-terminated butadiene-acrylonitrile rubber, and polyethersulfone; The compound curing aid includes tertiary amine curing agents and organic acids.

2. The elastic epoxy resin grouting material according to claim 1, characterized in that, The amine value of the quaternary Mannich reaction curing agent is 480~520 mgKOH / g; The raw materials of the quaternary Mannich reaction curing agent, calculated by parts by weight, include: Cashew phenol 60-80 parts, N-aminoethylpiperazine 20-40 parts, paraformaldehyde 20-30 parts, polypropylene glycol diglycidyl ether 10-30 parts.

3. The elastic epoxy resin grouting material according to claim 1, characterized in that, The amine curing agent includes any one of 2,4,6-tris(dimethylaminomethyl)phenol and benzyldimethylamine; The organic acid includes either methanesulfonic acid or p-toluenesulfonic acid. The mass ratio of the amine curing agent to the organic acid is 2:

1.

4. The elastic epoxy resin grouting material according to claim 1, characterized in that, The first component, in parts by mass, comprises: 70-80 parts of bisphenol F type epoxy resin, 5-15 parts of epoxy resin reactive diluent, 3-8 parts of alcohol non-reactive diluent, 2-5 parts of reactive phase separation toughening agent, and 0.8-1.5 parts of interface treatment agent; The second component comprises, by mass parts: 70-85 parts of quaternary Mannich reaction curing agent, 10-20 parts of chain extender, 1.0-2.5 parts of compound curing aid, and 2-5 parts of amine moisture stabilizer. The volume ratio of the first component to the second component is 1:1 to 1.

5.

5. The elastic epoxy resin grouting material according to claim 1, characterized in that, The viscosity of the bisphenol F type epoxy resin is 2000~2500 mPa. s; The epoxy resin reactive diluent includes any one of butyl glycidyl ether, benzyl glycidyl ether, and ethylene glycol diglycidyl ether. Alcohol-based inactive diluents include any one of ethanol, propylene glycol, and dipropylene glycol; Interface treatment agents include any one of silane coupling agents and phthalate coupling agents; Chain extenders include any one of the following: polypropylene glycol diglycidyl ether, 1,4-butanediol diglycidyl ether, neopentyl glycol diglycidyl ether, polyethylene glycol diglycidyl ether, and 1,6-hexanediol diglycidyl ether. Amine moisture stabilizers include any one of ketimine, aldolimine, or polyamide ketimine.

6. The elastic epoxy resin grouting material according to claim 1, characterized in that, The first component also includes a hydrophobic defoamer, selected from any one of organosilicon-fluorine composite defoamers and modified polyether siloxane defoamers. The first component, calculated by mass parts, includes 0.3 to 0.7 parts of the defoamer.

7. A method for preparing the elastic epoxy resin grouting material according to any one of claims 1 to 6, characterized in that, The preparation method includes: An epoxy resin reactive diluent and an alcohol-based non-reactive diluent are added sequentially to bisphenol F type epoxy resin. After mixing evenly, a reactive phase separation toughening agent and an interface treatment agent are added. The mixture is heated to 40~50℃ and stirred to obtain the first component. Add chain extender, compound curing aid and amine moisture stabilizer to quaternary Mannich reaction curing agent and mix and stir to obtain the second component; The first component and the second component are mixed to obtain an elastic epoxy resin grouting material.

8. The preparation method according to claim 7, characterized in that, The preparation method of the quaternary Mannich reaction curing agent includes: Cashew phenol and N-aminoethylpiperazine are mixed evenly according to the mass fraction. After heating to 40~50℃, paraformaldehyde is added in batches at intervals. The reaction is carried out at a reaction temperature of ≤80℃. Then, polypropylene glycol diglycidyl ether is added and the mixture is heated to 85~85℃ to obtain the quaternary Mannich reaction curing agent.

9. The application of the elastic epoxy resin grouting material according to any one of claims 1 to 6 in the repair of concrete structures.

10. The application according to claim 9, characterized in that, The concrete structure includes at least one of the following: subway tunnel, water-bearing tunnel, highway bridge, and building structure.

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