Epoxy mortar, method for producing same, and use thereof

Abstract

The application provides an epoxy mortar and a preparation method and application thereof; the composition of the epoxy mortar comprises an epoxy resin, a modified curing agent, a toughening agent, a cementing material and an aggregate; the mass proportions of the epoxy resin, the modified curing agent, the toughening agent, the cementing material and the aggregate in the epoxy mortar are 25-40%, 20-30%, 2-5%, 5-20% and 30-50% respectively; the composition of the modified curing agent comprises triethylenetetramine, modified polyamide, modified polyether amine, nano silicon dioxide and a water resistance dispersant. The epoxy mortar provided by the application has excellent water resistance, wet interface bonding strength and compressive strength, and can efficiently deal with the problems of high water head non-uniform stress distribution and high pressure water jet erosion in a gate sealing system.

Description

Technical Field

[0001] This invention belongs to the field of building materials technology, specifically relating to an epoxy mortar, its preparation method, and its application. Background Technology

[0002] As a crucial temporary structure in the overall cofferdam method, the diversion tunnel serves to create dry conditions for the main construction project while ensuring upstream flood control and downstream water supply, thus playing a vital role in ensuring construction progress and project safety. Typically, the diversion tunnel needs to be sealed once the main dam structure is completed and the reservoir is ready for impoundment. Rapid sealing of the diversion tunnel facilitates early reservoir impoundment and power generation, bringing significant economic and social benefits to the project. Currently, the sealing of the diversion tunnel intake often utilizes flat steel gates. Before gate installation, a complex gate-like portal needs to be pre-cast, and secondary concrete is poured within the gate slot to accommodate embedded components. The subsequently installed flat steel gate can slide within the gate slot to achieve opening and closing operations.

[0003] However, due to improper design and construction, when the deviation between the embedded parts of the gate slot and the centerline of the orifice exceeds the allowable range of the installation and acceptance specification "NB / T35045", a series of problems will arise: Under high water head pressure, point contact is likely to occur between the gate and the main rail of the gate slot after the gate is lowered, and the local contact stress increases significantly, exceeding the bearing limit of the slider material; the installation gap between the water-stop structure and the water-stop seat plate in the gate slot is prone to serious leakage under high water head conditions, which greatly hinders the subsequent plugging construction; when high-speed water flows through the gate slot, the negative pressure formed by the change of boundary conditions will cause cavitation and cavitation erosion damage, threatening the stability of the gate slot structure and the safety of the entire gate sealing system.

[0004] In critical processes such as diversion tunnel sealing, commonly used mortar materials are significantly inadequate in dealing with non-uniform stress distribution under high water head and resisting erosion by high-pressure water jets. There is an urgent need to develop a high-performance modified mortar material to ensure the stability and reliability of the gate sealing system. Summary of the Invention

[0005] To address the significant shortcomings of existing mortar materials in coping with high water head and non-uniform stress distribution, and resisting high-pressure water jet erosion, this invention provides an epoxy mortar. The epoxy mortar comprises epoxy resin, a modified curing agent, a toughening agent, a cementitious material, and aggregates. In the epoxy mortar, the mass percentages of the epoxy resin, the modified curing agent, the toughening agent, the cementitious material, and the aggregates are 25%–40%, 20%–30%, 2%–5%, 5%–20%, and 30%–50%, respectively.

[0006] The modified curing agent comprises triethylenetetramine, modified polyamide, modified polyetheramine, nano silica, and an anti-water dispersant.

[0007] Furthermore, in the raw material composition of the modified curing agent, the mass ratio of the triethylenetetramine, the modified polyamide, the modified polyetheramine, the nano-silica, and the anti-water dispersibility agent is 1:1.5~2:0.5~1:0.2~0.5:0.05~0.2;

[0008] The preparation process of the modified curing agent includes the following steps:

[0009] The triethylenetetramine was mixed with the modified polyamide and subjected to a first heat treatment to obtain an amine-amide pre-crosslinking intermediate.

[0010] The modified polyetheramine is mixed with the amine-amide pre-crosslinking intermediate and subjected to a second heat treatment to obtain the polyetheramine modified crosslinking intermediate;

[0011] The nano-silica was mixed with the polyetheramine-modified crosslinking intermediate and subjected to a third heat treatment to obtain a nano-silica composite crosslinked body.

[0012] Under heat preservation conditions, a mixture of the nano-silica composite crosslinker and the anti-water dispersant is obtained, and then cooled to room temperature to obtain the modified curing agent.

[0013] Furthermore, in the raw material composition of the modified polyetheramine, the mass ratio of polyetheramine, stearic acid, epichlorohydrin, and silane coupling agent is 4~6:1~3:1~3:1;

[0014] The preparation process of the modified polyetheramine includes the following steps: mixing the polyetheramine with the epichlorohydrin and subjecting it to a fourth heat treatment to obtain an epoxy-grafted polyetheramine intermediate;

[0015] Under heat preservation conditions, the epoxy-grafted polyetheramine intermediate is mixed with the stearic acid, and after the mixture is completely mixed, it is subjected to a fifth heat treatment to obtain the esterified polyetheramine modified body.

[0016] The esterified polyetheramine modifier is mixed with the silane coupling agent, and after the reaction is completed under heat preservation conditions, it is cooled to room temperature to obtain the modified polyetheramine.

[0017] Furthermore, the temperature of the first heating treatment is 120℃~150℃; the temperature of the second heating treatment is 160℃~180℃; the temperature of the third heating treatment is 180℃~200℃; the temperature of the fourth heating treatment is 60℃~80℃; and the temperature of the fifth heating treatment is 90℃~100℃.

[0018] Furthermore, the epoxy resin is prepared by mixing bisphenol A type epoxy resin, bisphenol F type epoxy resin and toughened epoxy resin;

[0019] The mass ratio of the bisphenol A type epoxy resin, the bisphenol F type epoxy resin, and the toughened epoxy resin is 4~6:2~3:1~2.

[0020] Furthermore, the epoxy mortar also includes a solvent; the solvent in the epoxy mortar accounts for 2% to 5% by mass; the solvent includes acetone;

[0021] The toughening agent includes dibutyl phthalate, the cementitious material includes PO425 cement, and the aggregate includes marble medium sand.

[0022] Furthermore, the nano-silica has a particle size of 20-50 nm and a specific surface area of ​​200-350 m² / g;

[0023] The preparation process of the modified polyamide includes: mixing ethylenediamine and terephthalic acid, subjecting the mixture to a sixth heating treatment to undergo a polycondensation reaction, thereby obtaining the modified polyamide; wherein the mass ratio of ethylenediamine to terephthalic acid is 1:0.62~1.85.

[0024] This invention provides another method for preparing epoxy mortar as described in any one of the above claims, wherein the epoxy resin, the modified curing agent, the toughening agent, the cementitious material, and the aggregate in the raw material composition of the epoxy mortar have mass percentages of 25%–40%, 20%–30%, 2%–5%, 5%–20%, and 30%–50%, respectively.

[0025] The preparation process of the epoxy mortar includes the following steps:

[0026] The cementitious material and the aggregate are mixed to obtain a dry cement mortar mix;

[0027] The epoxy resin, the toughening agent, and the solvent are mixed to obtain an epoxy resin mixture.

[0028] The modified curing agent, the epoxy resin mixture, and the cement mortar dry mix are mixed to obtain the epoxy mortar; the mass ratio of the triethylenetetramine, the modified polyamide, the modified polyetheramine, the nano silica, and the anti-water dispersibility agent in the modified curing agent is 1:1.5~2:1:0.5~1:0.2~0.5:0.05~0.2.

[0029] This invention provides an application of epoxy mortar as described in any of the above claims in the field of water conservancy engineering.

[0030] This invention provides an application of epoxy mortar as described in any of the above claims in the sealing and reinforcement of gate slots in diversion tunnels.

[0031] Compared with the prior art, the present invention has at least the following advantages:

[0032] This invention provides an epoxy mortar, comprising epoxy resin and a modified curing agent, wherein the modified curing agent comprises triethylenetetramine, modified polyamide, modified polyetheramine, nano-silica, and an anti-water dispersibility agent. The epoxy mortar provided by this invention possesses excellent anti-water dispersibility, wet interface bonding strength, and compressive strength, effectively addressing the problems of high-head non-uniform stress distribution and high-pressure water jet erosion in gate sealing systems.

[0033] Optimized water dispersibility. The epoxy mortar prepared in this invention achieves excellent water dispersibility through a four-pronged synergistic mechanism of chemical anchoring (modified curing agent), interface strengthening (nano-silica), dynamic protection (anti-water dispersibility agent), and physical sealing (hydration of cementitious materials). The modified curing agent "chemically locks" the particles in the cross-linked network; the anti-water dispersibility agent prevents particle detachment through steric hindrance and electrostatic repulsion; nano-silica strengthens the interfacial transition zone, resisting shear stripping; and the hydration products of the cementitious material seal the pores, limiting water permeation.

[0034] Optimization of bonding strength at damp interfaces. The modified curing agent achieves full-process interface strengthening through multi-component synergy, including "rapid cross-linking and anchoring, water molecule replacement, chemical bonding, and hydrophobic sealing"; nano-silica and toughening agents improve interface toughness from the perspectives of microstructure and stress absorption, respectively; cementitious materials and aggregates reduce porosity through physical filling and chemical composite, blocking the path of moisture intrusion.

[0035] Compressive strength optimization. The modified curing agent, through multi-component synergy, constructs a high cross-linking density network (triethylenetetramine + modified polyamide), achieves nanoscale reinforcement (nano silica) and hydrophobic barrier (modified polyetheramine), and improves the intrinsic strength of the material from the molecular to the microscale; epoxy resin and toughening agent form a "rigid-tough" composite matrix, which absorbs stress and prevents crack propagation; cementitious materials and aggregates, through multi-level filling and chemical compounding, reduce porosity and compensate for shrinkage, forming a dense and defect-free microstructure.

[0036] In summary, the epoxy mortar of this invention achieves excellent water dispersibility, wet interface bonding strength, and optimized compressive strength through the synergistic effect of its components, providing reliable material support for key components such as gate sealing systems in water conservancy projects.

[0037] This invention provides a method for preparing epoxy mortar. By precisely controlling the mass ratio of each component of the modified curing agent and the mass percentage of each component in the epoxy mortar, a cross-linked structure with optimized performance is formed, resulting in epoxy mortar with excellent resistance to water dispersibility, wet interface bonding strength, and compressive strength.

[0038] This invention provides an application of epoxy mortar in hydraulic engineering. Based on the optimized water dispersibility, wet interface bonding strength, and compressive strength of the epoxy mortar in this invention, it exhibits excellent application prospects in the field of hydraulic engineering, and can be applied to scenarios such as dam crack repair, hydraulic structure reinforcement, and underwater structure repair. For example, in dam crack repair, the excellent adhesion and high compressive strength of epoxy mortar can accurately fill cracks, restore the integrity of the dam structure, effectively block leakage, and build a solid defense for dam safety. In the reinforcement of hydraulic structures, due to its high strength and excellent adhesion to metal components, it can strengthen key parts of structures such as sluice gates and aqueducts, significantly improving their load-bearing capacity and stability. In the field of underwater structure repair, its excellent water dispersibility allows for smooth underwater construction without vibration, perfectly meeting the repair needs of underwater structures such as hydropower station intakes and locks, effectively solving underwater construction problems, and providing a solid guarantee for the stable operation of hydraulic projects.

[0039] This invention provides the application of epoxy mortar in the sealing and reinforcement of gate slots in diversion tunnels. The solidified epoxy mortar has high bonding strength and high compressive strength, and can be tightly bonded to concrete and metal components. When poured under dynamic water conditions, it exhibits excellent water dispersibility and good adaptability to grouting construction, making it suitable for sealing and reinforcement of gate slots in diversion tunnels of hydropower stations. Detailed Implementation

[0040] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. 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.

[0041] Furthermore, the technical solutions of the various embodiments of the present invention can be combined with each other, but only if they are based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such combination of technical solutions does not exist and is not within the scope of protection claimed by the present invention.

[0042] When numerical ranges are given in the embodiments, it should be understood that, unless otherwise stated in the present invention, both endpoints of each numerical range and any value between the two endpoints may be selected. Unless otherwise defined, all technical and scientific terms used in this invention, as well as the prior art known to those skilled in the art and the description of the invention, may be implemented using any prior art methods, devices, and materials similar to or equivalent to the methods, devices, and materials in the embodiments of the present invention.

[0043] This invention provides an epoxy mortar, the raw material composition of which includes epoxy resin, modified curing agent, toughening agent, cementitious material and aggregate; in the epoxy mortar, the mass percentages of epoxy resin, modified curing agent, toughening agent, cementitious material and aggregate are 25% to 40%, 20% to 30%, 2% to 5%, 5% to 20%, and 30% to 50%, respectively.

[0044] It should be noted that in some embodiments of the present invention, the total mass percentage of epoxy resin, modified curing agent, toughening agent, cementing material and aggregate is 100%; in other embodiments of the present invention, the total mass percentage of epoxy resin, modified curing agent, toughening agent, cementing material, aggregate and solvent is 100%.

[0045] In this invention, epoxy mortar can be applied to the field of water conservancy engineering.

[0046] In this invention, epoxy mortar can be applied to the sealing and reinforcement of the gate slot of the diversion tunnel. Especially when the deviation between the centerline of the embedded part of the gate slot and the centerline of the orifice exceeds the allowable range of the installation and acceptance specification "NB / T 35045", the following problems are likely to occur. In this case, the application of epoxy mortar is crucial:

[0047] Stress concentration at contact: After the gate is lowered, point contact is easily formed between it and the main rail of the gate slot. Under the action of high water head pressure, the stress at the contact point of the slider will increase significantly, exceeding the ultimate bearing capacity of the slider material.

[0048] Sealing failure: Gaps may occur between the water-stop structure and the water-stop seat plate inside the door groove due to installation deviations. Under high water head conditions, this may lead to serious water leakage, which will cause great difficulties for subsequent plugging construction.

[0049] Cavitation and cavitation damage: When high-speed water flows through the gate slot, negative pressure will be formed locally due to changes in boundary conditions, which will lead to cavitation and cavitation damage. In severe cases, it will cause the gate slot structure to become unstable, endangering the safety of the entire gate sealing system.

[0050] In this invention, the epoxy resin can be prepared by mixing bisphenol A type epoxy resin, bisphenol F type epoxy resin and toughened epoxy resin; in some embodiments, the mass ratio of bisphenol A type epoxy resin, bisphenol F type epoxy resin and toughened epoxy resin can be 4~6:2~3:1~2.

[0051] In this invention, the toughening agent may include dibutyl ester.

[0052] In this invention, the cementitious material may include PO425 cement.

[0053] In this invention, the aggregate may include sand from marble, and the fineness modulus of the aggregate may be 2.2 to 2.8.

[0054] In this invention, the epoxy mortar may also include a solvent, which may include acetone, and the mass percentage of the solvent in the epoxy mortar may be 2% to 5%.

[0055] In this invention, the modified curing agent may comprise triethylenetetramine, modified polyamide, modified polyetheramine, nano-silica, and an anti-water-dispersibility agent. The mass ratio of triethylenetetramine, modified polyamide, modified polyetheramine, nano-silica, and the anti-water-dispersibility agent is 1:1.5~2:1:0.5~1:0.2~0.5:0.05~0.2.

[0056] In some embodiments of the present invention, the particle size of nano-silica can be 20-50 nm, and the specific surface area can be 200-350 m² / g. Nano-silica of this particle size can effectively fill the micropores in the mortar, enhance the compactness of the mortar, and form a stronger interfacial bond with epoxy resin and modified curing agent. Furthermore, the addition of nano-silica helps to provide higher reactivity, significantly enhancing the speed and strength of the curing reaction and improving the adhesion of the epoxy resin.

[0057] In this embodiment of the invention, the water-resistant dispersant can be COADIS™ 123K high water-resistant dispersant.

[0058] In some embodiments of the present invention, the preparation of the modified curing agent may include the following steps:

[0059] A1. Triethylenetetramine is mixed with modified polyamide and subjected to a first heat treatment to obtain an amine-amide pre-crosslinking intermediate. In step A1, the amino groups in the triethylenetetramine react with the amide groups in the modified polyamide to promote the initial crosslinking of the modified curing agent system.

[0060] In some embodiments, the temperature of the first heat treatment can be 120°C to 150°C.

[0061] In some embodiments of the present invention, the preparation of modified polyamide may include the steps of: mixing ethylenediamine and terephthalic acid, subjecting the mixture to a sixth heating treatment to undergo a polycondensation reaction, thereby obtaining modified polyamide; wherein the mass ratio of ethylenediamine to terephthalic acid is 1:0.62~1.85.

[0062] The temperature for the sixth heat treatment can be 200℃~250℃.

[0063] In some specific embodiments of the present invention, the preparation of modified polyamide may include the following steps: First, ethylenediamine and terephthalic acid are mixed in a reaction vessel at a mass ratio of 1:0.62~1.85. Then, the mixture is heated to 200℃~250℃ to induce a polycondensation reaction, where the amino groups in the ethylenediamine react with the carboxyl groups in the terephthalic acid to form amide bonds (–CONH–), while simultaneously releasing water. Finally, after appropriate evaporation and dehydration treatment, the modified polyamide is obtained.

[0064] A2. The modified polyetheramine is mixed with the amine-amide pre-crosslinking intermediate and subjected to a second heat treatment to obtain the polyetheramine modified crosslinking intermediate.

[0065] In some embodiments, mixing the modified polyetheramine with the amine-amide precrosslinking intermediate may include: gradually adding the modified polyetheramine to the amine-amide precrosslinking intermediate.

[0066] In some embodiments, the duration of the second heat treatment can be 160°C to 180°C.

[0067] In some embodiments, the modified polyetheramine can be prepared by mixing polyetheramine, stearic acid, epichlorohydrin and silane coupling agent, wherein the mass ratio of polyetheramine, stearic acid, epichlorohydrin and silane coupling agent can be 4~6:1~3:1~3:1; in some specific embodiments, the mass ratio of polyetheramine, stearic acid, epichlorohydrin and silane coupling agent can be 4.5~5.5:1.5~2.5:1.5~2.5:1.5

[0068] In some more specific embodiments, the preparation of modified polyetheramines may include the steps of:

[0069] A21. Polyetheramine is mixed with epichlorohydrin and subjected to a fourth heat treatment to obtain an epoxy-grafted polyetheramine intermediate.

[0070] In some embodiments, the temperature of the fourth heat treatment can be 60°C-80°C.

[0071] A22. Under heat preservation conditions, epoxy-grafted polyetheramine intermediates are mixed with stearic acid, and after the mixture is completely mixed, it is subjected to a fifth heat treatment to obtain esterified polyetheramine modified body.

[0072] In some embodiments, the system temperature under insulation conditions can be 60-80°C, that is, stearic acid is added dropwise to epoxy-grafted polyetheramine, and the system temperature is controlled at 60-80°C throughout the entire addition process. In other embodiments, the system temperature under insulation conditions can be controlled at 65-75°C.

[0073] In some embodiments, the temperature of the fifth heating treatment can be 90°C to 100°C, and the duration can be 2 to 3 hours.

[0074] A23. The esterified polyetheramine modifier is mixed with a silane coupling agent, and after the reaction is completed under heat preservation conditions, it is cooled to room temperature to obtain the modified polyetheramine;

[0075] The mass ratio of polyetheramine, stearic acid, epichlorohydrin and silane coupling agent is 4~6:1~3:1~3:1.

[0076] In some more specific embodiments, the preparation of modified polyetheramines may include the steps of:

[0077] First, pour 2.5 parts of polyetheramine and 1 part of epichlorohydrin into a reaction flask and start stirring, controlling the stirring speed at 150~200 r / min to ensure uniform mixing of the reactants. Next, heat the reaction system to 60℃~80℃ to promote the reaction between epichlorohydrin and the amino groups in the polyetheramine, forming a partially modified product. Then, add stearic acid (1 part) dropwise over 1.5 hours. The addition of stearic acid improves the hydrophobicity of the polyetheramine and enhances its compatibility with other components. Maintain the system temperature at 60℃~80℃ throughout the dropwise addition process to ensure a stable reaction. After the dropwise addition is complete, raise the reaction system temperature to 90℃~100℃ and continue the reaction for 2~3 hours to ensure sufficient reaction between stearic acid and polyetheramine, forming a modified polyetheramine. Finally, add 0.5 parts of silane coupling agent to improve the bonding force between the modified polyetheramine and nano-silica. After adding the silane coupling agent, continue stirring for 30–60 minutes to ensure that the silane coupling agent reacts fully and is uniformly dispersed with the modified polyetheramine. After the reaction is complete, lower the system temperature to 50°C, and then cool to room temperature to obtain the modified polyetheramine.

[0078] In some embodiments, the molecular chain of the modified polyetheramine obtained by the present invention comprises the following characteristics:

[0079] Polyether segments: accounting for 60% to 75% of the main chain mass (measured by carbon NMR spectroscopy).

[0080] Stearate group: 10-15 g per 100 g of product (quantitative analysis by infrared spectroscopy);

[0081] Silane coupling agent residues: X-ray photoelectron spectroscopy (XPS) showed that the silicon content was 0.5% to 1.2% by mass.

[0082] A3. Nano-silica is mixed with polyetheramine modified crosslinking intermediate, and subjected to a third heat treatment. Through uniform dispersion and reaction, a high-performance nanocomposite structure is formed, which enhances the mechanical strength and water resistance of the modified curing agent, thus obtaining a nano-silica composite crosslinked body.

[0083] In some embodiments, mixing nano-silica with a polyetheramine-modified crosslinking intermediate may include adding nano-silica to the polyetheramine-modified crosslinking intermediate.

[0084] In some embodiments, in step A3, the temperature of the third heating treatment can be 180°C to 200°C.

[0085] A4. Under heat preservation conditions, a mixture of nano-silica composite crosslinker and anti-water dispersant is obtained, and then cooled to room temperature to obtain a modified curing agent.

[0086] In some specific embodiments of the present invention, the preparation of the modified curing agent may include the following steps:

[0087] First, triethylenetetramine and modified polyamide were poured into a reaction vessel according to their weight and mixed. The mixture was then heated to 120°C–150°C to allow the amino groups in the triethylenetetramine to react with the amide groups in the modified polyamide, promoting the initial crosslinking of the modified curing agent system. Next, modified polyetheramine was gradually added, and the mixture was heated further to 160°C–180°C. At this temperature, the amino groups in the modified polyetheramine reacted with the epoxy groups in the epoxy resin, improving the flexibility and water resistance of the modified curing agent. Then, nano-silica was added to the reaction mixture in an appropriate proportion, and the mixture was heated further to 180°C–200°C. Through uniform dispersion and reaction, a high-performance nanocomposite structure was formed, enhancing the mechanical strength and water resistance of the modified curing agent. Finally, an anti-water dispersant was added to ensure uniform mixing with the other components, and the system was cooled to room temperature to obtain the modified curing agent.

[0088] In this invention, step A4 is carried out under heat preservation conditions, which serves the following purposes: ensuring uniform dispersion and stable binding of the anti-water dispersant; promoting chemical bonding or physical adsorption; and avoiding phase separation of components caused by cooling.

[0089] It should be noted that the detailed reactions between the components in the modified curing agent provided by this invention are as follows:

[0090] The modified curing agent provided by the present invention is made by reacting triethylenetetramine, modified polyamide, modified polyetheramine, nano silica and anti-water dispersibility agent.

[0091] The epoxy mortar provided by this invention has an unconfined compressive strength of not less than 130 MPa at 28 days, an unconfined compressive strength of not less than 120 MPa at 28 days, a wet interface bond strength of not less than 6.5 MPa, an initial setting time of not more than 80 min, a final setting time of not more than 150 min, and a flowability of 210–250 mm.

[0092] This invention provides a method for preparing any of the epoxy mortars described above, comprising the following steps:

[0093] S1. Mix the cementitious materials and aggregates to obtain dry cement mortar mix.

[0094] In this invention, the aggregate may include sand from marble, and the fineness modulus of the aggregate may be 2.2 to 2.8.

[0095] In this invention, the cementitious material may include PO425 cement.

[0096] In some embodiments, PO425 cement and dry marble sand can be poured into a twin-shaft mixer and mixed at a speed of 50-70 r / min for 5-10 min to obtain cement mortar dry mix A.

[0097] S2. Mix epoxy resin, toughening agent and solvent to obtain epoxy resin mixture.

[0098] In this invention, the epoxy resin can be prepared by mixing bisphenol A type epoxy resin, bisphenol F type epoxy resin, and toughened epoxy resin; in some embodiments, the mass ratio of bisphenol A type epoxy resin, bisphenol F type epoxy resin, and toughened epoxy resin can be 4~6:2~3:1~2. Compared with mainstream single-component or two-component epoxy resins, the three-component epoxy resin of this invention can provide better dynamic mechanical properties, maintaining high consolidation characteristics and compressive strength under high water head pressure, while improving the toughness and ductility of the mortar and reducing crack formation.

[0099] In this invention, the toughening agent may include dibutyl ester.

[0100] In this invention, the solvent may include acetone.

[0101] In some embodiments of the present invention, the step of mixing epoxy resin, toughening agent, and solvent to obtain an epoxy resin mixture may include: placing type A epoxy resin (EPIKOTE 828), bisphenol F type epoxy resin (EPIKOTE 862), and toughening epoxy resin (EPIKOTE 1001) in an oven for preheating for 10-20 minutes at a temperature controlled at 40-50°C to ensure good flowability of the epoxy resin. Then, pour the mixture into a corrosion-resistant stainless steel mixing vessel and initially stir at 60-80 r / min for 8-10 minutes to ensure complete resin mixing, thus obtaining mixed epoxy resin B.

[0102] Then, slowly pour dibutyl ester into the mixed epoxy resin B to avoid uneven mixing caused by adding it all at once. Then cool down, controlling the temperature at 30~35℃, and stir at 80~100 r / min for 10~15 min to ensure that the dibutyl ester and the mixed epoxy resin are fully mixed to obtain mixed epoxy resin C.

[0103] Finally, slowly pour acetone into the mixed epoxy resin C and stir at 80~120 r / min for 15~20 min to ensure that the acetone is completely dissolved in the resin solution, thus obtaining mixed epoxy resin D, i.e., epoxy resin mixture.

[0104] S3. Preparation of the modified curing agent; the mass ratio of triethylenetetramine, modified polyamide, modified polyetheramine, nano-silica, and anti-water dispersibility agent in the modified curing agent is 1:1.5~2:0.5~1:0.2~0.5:0.05~0.2. This invention, through the use of the modified curing agent, significantly optimizes the curing process of epoxy mortar, enhances the adhesion between the mortar and the substrate, improves the overall durability and anti-water dispersibility, thereby improving its application effect in the sealing of gate slots in diversion tunnels of hydropower stations.

[0105] In some embodiments, the preparation of modified polyamide may include the steps of: mixing ethylenediamine and terephthalic acid, subjecting the mixture to a sixth heating treatment to undergo a polycondensation reaction, thereby obtaining modified polyamide; wherein the mass ratio of ethylenediamine to terephthalic acid is 1:0.62~1.85.

[0106] In some specific embodiments of the present invention, the preparation of modified polyamide may include the following steps: First, ethylenediamine and terephthalic acid are mixed in a reaction vessel at a mass ratio of 1:0.62~1.85. Then, the mixture is heated to 200℃~250℃ to induce a polycondensation reaction, where the amino groups in the ethylenediamine react with the carboxyl groups in the terephthalic acid to form amide bonds (–CONH–), while simultaneously releasing water. Finally, after appropriate evaporation and dehydration treatment, the modified polyamide is obtained.

[0107] In some embodiments, the molecular chain of the modified polyamide obtained in this invention comprises the following characteristics:

[0108] Amide bonds: comprise 100% of the repeating units in the main chain;

[0109] Benzene ring: 12-18 g per 100 g of product;

[0110] Terminal group type: The molar ratio of amino terminal group (–NH2) to carboxyl terminal group (–COOH) is 0.8~1.2:1.

[0111] In some embodiments, the preparation of modified polyetheramine includes steps A21 to A23 described above.

[0112] In some more specific embodiments, the preparation of the modified curing agent includes the following steps: First, triethylenetetramine and modified polyamide are poured into a reaction vessel and mixed, then heated to 120°C~150°C, allowing the amino groups in the triethylenetetramine to react with the amide groups in the modified polyamide, promoting the initial crosslinking of the modified curing agent system. Then, modified polyetheramine is gradually added, and heating continues to 160°C~180°C. At this temperature, the amino groups in the modified polyetheramine react with the epoxy groups in the epoxy resin, improving the flexibility and water resistance of the modified curing agent. Next, nano-silica is added to the reaction mixture in an appropriate proportion, and heating continues to 180°C~200°C, forming a high-performance nanocomposite structure through uniform dispersion and reaction, enhancing the mechanical strength and water resistance of the modified curing agent. Finally, an anti-water dispersant is added to ensure uniform mixing with other components, and the system is cooled to room temperature to obtain the modified curing agent.

[0113] It should be noted that the above steps S1, S2, and S3 do not need to follow a specific order. Operators can flexibly adjust the execution order of each step according to the specific situation.

[0114] In some embodiments, the modified curing agent prepared according to the present invention has a pot life extended to 2-6 hours as measured by ASTM D2471 "Determination of pot life of thermosetting materials", a tensile strength of 50-80 MPa as measured by ASTM D638 "Test method for tensile properties of plastics", an impact strength of 40-60 kJ / m² as measured by ISO 179-1 "Test method for impact properties of simply supported beams of plastics", and a water absorption rate of <1% as measured by ASTM D570 "Test method for water absorption of plastics".

[0115] S4. Mix the modified curing agent, epoxy resin mixture and cement mortar dry mix to obtain epoxy mortar.

[0116] In some embodiments, step S4 may include:

[0117] S41. First, preheat the modified curing agent to 30~40℃, then pour it into the epoxy resin mixture in batches to avoid local curing or uneven mixing caused by adding it all at once. Increase the stirring speed to 100~150 r / min and stir for 20~30 min. After mixing, let it stand for 10~15 minutes to allow internal air bubbles to escape, thus obtaining the epoxy adhesive.

[0118] S42. Next, add the epoxy adhesive to the dry cement mortar in batches, stirring for 5 minutes after each addition to ensure that the epoxy adhesive fully coats the cement and sand particles. After all the epoxy adhesive has been added, increase the stirring speed to 100~150 r / min and stir for 10~15 minutes. After mixing, let it stand for 10 minutes to allow the air bubbles to escape naturally. The epoxy mortar preparation is now complete.

[0119] The mass percentages of epoxy resin, modified curing agent, toughening agent, cementitious material and aggregate in epoxy mortar are 25%–40%, 20%–30%, 2%–5%, 5%–20%, and 30%–50%, respectively.

[0120] This invention provides an application of any of the epoxy mortars described above in the field of water conservancy engineering.

[0121] In some embodiments of the present invention, the epoxy mortar may include epoxy mortar prepared by the above preparation method.

[0122] This invention provides an application of any of the above-mentioned epoxy mortars in the sealing and reinforcement of gate slots in diversion tunnels.

[0123] In some embodiments of the present invention, the epoxy mortar may include epoxy mortar prepared by the above preparation method.

[0124] Based on the aforementioned performance improvements of epoxy mortar, the application effects of the epoxy mortar in this application during the sealing and reinforcement of gate slots in water conservancy projects and diversion tunnels are as follows:

[0125] The epoxy mortar provided by this invention is not limited by reservoir operating conditions and has strong construction adaptability. Its mixing and underwater pouring processes are simple, require no complex equipment, have low construction costs, and short construction periods, meeting the needs of high-efficiency projects;

[0126] During the pouring process, the epoxy mortar provided by this invention has self-leveling and self-compacting properties, allowing for construction without vibration, and exhibits extremely strong resistance to water dispersion in underwater environments. The solidified body formed after curing has high compressive and shear strength, enabling it to bond tightly to concrete and gate metal components, ensuring the overall structural stability of the system.

[0127] After sealing, the epoxy mortar consolidation body provided by this invention can effectively share the non-uniform load of the gate under high water head pressure and transfer the load to the concrete structure downstream of the gate slot, thereby improving the bearing capacity. At the same time, the consolidation body can seal irregular water-stop gaps, prevent leakage, avoid cavitation and erosion damage to the gate slot caused by high-speed water flow, significantly improve the safety factor of the diversion tunnel sealing system, and ensure the long-term stable operation of the project.

[0128] To facilitate a further understanding of the present invention by those skilled in the art, the following examples are provided:

[0129] Example 1

[0130] This embodiment provides a modified epoxy mortar for sealing and reinforcing the gate slot of a diversion tunnel, with the following ingredients:

[0131] Epoxy mortar is composed of epoxy resin, modified curing agent, toughening agent, cementitious materials and aggregates, and solvent acetone, wherein:

[0132] Epoxy resin: The raw materials for epoxy resin are bisphenol A type epoxy resin EPIKOTE 828 (15 parts), bisphenol F type epoxy resin EPIKOTE 862 (9 parts) and toughened epoxy resin EPIKOTE 1001 (6 parts).

[0133] Modified curing agent: The raw materials are triethylenetetramine (6 parts), modified polyamide (11 parts), modified polyetheramine (5 parts), nano silica (2 parts) and anti-water dispersing agent (1 part).

[0134] The modified polyamide is obtained by the following method: It is prepared by reacting ethylenediamine and terephthalic acid. Specifically, 5 parts ethylenediamine and 6 parts terephthalic acid are mixed in a reaction vessel, then heated to 230°C and stirred at 400 r / min to induce a polycondensation reaction. The amino groups in the ethylenediamine react with the carboxyl groups of the terephthalic acid to form amide bonds (–CONH–), releasing water simultaneously. Finally, after appropriate evaporation and dehydration treatment, the modified polyamide is obtained.

[0135] Modified polyetheramine was obtained by the following method: First, 2.5 parts of polyetheramine and 1 part of epichlorohydrin were poured into a reaction flask and stirred at a speed of 150-200 r / min to ensure uniform mixing of the reactants. Next, the reaction system was heated to 80℃ to promote the reaction between epichlorohydrin and the amino groups in the polyetheramine, forming an epoxy-grafted polyetheramine intermediate. Then, stearic acid (1 part) was added dropwise to the epoxy-grafted polyetheramine intermediate over a period of 1.5 h. The addition of stearic acid improves the hydrophobicity of the polyetheramine and enhances its compatibility with other components. The system temperature was maintained at 70℃ throughout the addition process to ensure a stable reaction. After the addition was complete, the reaction system temperature was raised to 90℃ and the reaction continued for 2.5 h to ensure sufficient reaction between stearic acid and polyetheramine, forming the esterified polyetheramine modifier. Finally, 0.5 parts of silane coupling agent were added to improve the bonding force between the modified polyetheramine and nano-silica. After adding the silane coupling agent, stirring was continued for 50 minutes to ensure that the silane coupling agent and the modified polyetheramine reacted fully and were evenly dispersed. After the reaction was complete, the system temperature was lowered to 50°C and then cooled to room temperature to obtain the modified polyetheramine.

[0136] Toughening agent: dibutyl ester (2 parts);

[0137] Solvent: Acetone (3 parts);

[0138] Cementitious material: PO425 cement (5 parts);

[0139] The aggregate is medium marble sand (35 parts) with a fineness modulus of 2.2~2.8.

[0140] The preparation process of epoxy mortar is as follows:

[0141] S1. Pour PO425 cement and dry marble medium sand into a twin-shaft mixer and mix at 50 r / min for 10 min to obtain cement mortar dry mix A.

[0142] S2. Mix epoxy resin, toughening agent and solvent to obtain epoxy resin mixture.

[0143] Type A epoxy resin (EPIKOTE 828), bisphenol F type epoxy resin (EPIKOTE 862), and toughened epoxy resin (EPIKOTE 1001) were preheated in an oven for 15 minutes at 45°C to ensure good flowability. The mixture was then poured into a corrosion-resistant stainless steel mixing vessel and stirred at 70 rpm for 9 minutes to ensure complete resin mixing, yielding mixed epoxy resin B.

[0144] Then, dibutyl ester is slowly poured into the mixed epoxy resin B to avoid uneven mixing caused by adding it all at once. Then, the temperature is lowered to 35°C and stirred at 90 r / min for 15 min to ensure that the dibutyl ester and the mixed epoxy resin are fully mixed, thus obtaining mixed epoxy resin C.

[0145] Finally, acetone is slowly poured into mixed epoxy resin C and stirred at 100 r / min for 15 min to ensure that the acetone is completely dissolved in the resin solution, thus obtaining mixed epoxy resin D, i.e., epoxy resin mixture.

[0146] S3. Prepare the modified curing agent.

[0147] First, triethylenetetramine and modified polyamide are mixed in a reactor and heated to 150°C to allow the amino groups in the triethylenetetramine to react with the amide groups in the modified polyamide, promoting the initial crosslinking of the modified curing agent system. Then, modified polyetheramine is gradually added, and heating continues to 180°C. Next, nano-silica is added to the reaction mixture in an appropriate proportion, and heating continues to 180°C. Through uniform dispersion and reaction, a high-performance nanocomposite structure is formed, enhancing the mechanical strength and water resistance of the modified curing agent. Finally, an anti-water dispersant is added to ensure uniform mixing with other components, and the system is cooled to room temperature to obtain the modified curing agent.

[0148] S4. Mix the modified curing agent, epoxy resin mixture and cement mortar dry mix to obtain epoxy mortar.

[0149] First, preheat the modified curing agent to 40℃, then pour it into the epoxy resin mixture in batches to avoid localized curing or uneven mixing caused by adding it all at once. Increase the stirring speed to 150 r / min and stir for 25 min. After mixing, let it stand for 15 minutes to allow internal air bubbles to escape, thus obtaining the epoxy adhesive.

[0150] Next, add the epoxy adhesive to the dry cement mortar in batches, stirring for 5 minutes after each addition to ensure that the epoxy adhesive fully coats the cement and sand particles. After all the epoxy adhesive has been added, increase the stirring speed to 150 r / min and stir for 15 minutes. After mixing, let it stand for 10 minutes to allow the air bubbles to escape naturally. The epoxy mortar is now ready.

[0151] The properties of the epoxy mortar prepared in this embodiment are shown in Table 1.

[0152] Referring to the provisions of GB / T 17671-1999 "Test Method for Strength of Cement Mortar" regarding the immersion test, the mass loss rate of epoxy mortar measured in this embodiment was 2.1% to 3.8% in multiple 28-day underwater immersion tests.

[0153] Example 2

[0154] This embodiment proposes a novel method for sealing and reinforcing the gate slot of a diversion tunnel. The following section, using a practical engineering example, details the preparation and application of the epoxy mortar used for sealing and reinforcing the gate slot of the diversion tunnel in this invention.

[0155] This case study presents a hydropower station project located on the upper reaches of a river. With a designed installed capacity of 2 million kilowatts, it is classified as a Class I large-scale project, primarily focused on power generation while also promoting local economic and social development. The project area is situated in a high mountain and canyon region, with a V-shaped valley, robust mountains, and roughly symmetrical sides, exposing bedrock. During construction, a full-section cofferdam method was used for riverbed diversion, and two diversion tunnels were constructed. A central pier was installed in the middle of each diversion tunnel, dividing it into left and right openings, each equipped with a sealing gate.

[0156] To address the gate installation and sealing reinforcement requirements in the aforementioned project, the epoxy mortar prepared in Example 1 was used to solve the problems of water leakage and excessive slider line load caused by installation deviations in the diversion tunnel gates of the aforementioned large high-head hydropower station.

[0157] Application effect:

[0158] The epoxy mortar prepared in Example 1 is not limited by reservoir operating conditions and has strong construction adaptability. Its mixing and underwater pouring processes are simple, require no complex equipment, have low construction costs, and short construction periods, meeting the needs of high-efficiency projects.

[0159] During the pouring process, epoxy mortar exhibits self-leveling and self-compacting properties, allowing for construction without vibration, and demonstrates strong resistance to water dispersion in underwater environments. The solidified body formed after curing possesses high compressive and shear strength, enabling it to bond tightly to damp concrete and gate metal components, ensuring the overall structural stability of the system.

[0160] After sealing, the epoxy mortar consolidation effectively distributes the non-uniform load on the gate under high water head pressure and transfers the load to the downstream concrete structure of the gate slot, thus improving its bearing capacity. Simultaneously, this consolidation seals irregular water-stop gaps, preventing leakage and avoiding cavitation and erosion damage to the gate slot caused by high-speed water flow. This significantly improves the safety factor of the diversion tunnel sealing system and ensures the long-term stable operation of the project.

[0161] Comparative Example 1

[0162] Compared to Example 1, all other conditions remained unchanged in this comparative example, except that the preparation of the modified polyamide was adjusted as follows:

[0163] Modified polyamide is prepared by reacting diethylenetriamine and terephthalic acid. Specifically, 4 parts of diethylenetriamine (TETA) and 6 parts of terephthalic acid (TPA) are mixed and dissolved in acetone. The reaction is carried out in a three-necked flask at a temperature of 230°C, a stirring rate of 400 r / min, and a reaction time of 4 h. During the reaction, moisture is removed through a condenser to maintain a stable temperature. After the reaction, the mixture is allowed to cool naturally to room temperature, and the modified polyamide product is extracted and separated using a solvent to remove unreacted substances. Finally, the product is vacuum dried (50°C to 80°C) and pulverized into granules or blocks.

[0164] According to the provisions of GB / T 17671-1999 "Test Method for Strength of Cement Mortar" regarding the immersion test, the mass loss rate of the epoxy mortar measured in this comparative example during the 28-day underwater immersion test was 6% to 7%.

[0165] Comparative Example 2

[0166] Compared to Example 1, all other conditions remained unchanged in this comparative example, except that the preparation of the modified polyetheramine was adjusted as follows:

[0167] Modified polyetheramine is prepared by reacting a mixture of vinyl polyether, DGEBA type epoxy resin, lauric acid and γ-aminopropyltriethoxysilane.

[0168] Specifically: 3 parts of aminovinyl polyether (Jeffamine ED-600) and 1 part of DGEBA type epoxy resin were added to a reaction flask. Stirring was started and maintained at 150-200 r / min to ensure uniform mixing of the reactants. The reaction system was heated to 80℃ to promote the reaction between the epoxy resin and the amino group in the polyetheramine, and the reaction was continued for 1.5 hours. Lauric acid (0.8 parts) was added dropwise over 1 hour, maintaining the temperature at 70℃ to ensure uniform mixing of stearic acid. The temperature was raised to 100℃, and the reaction continued for 2 hours to ensure complete reaction and formation of the modified product. 0.8 parts of KH-550 silane coupling agent were added, and stirring was continued for 30 minutes to ensure sufficient reaction and dispersion of the coupling agent and the modified polyetheramine. After the reaction was complete, the system temperature was lowered to 60℃ and then allowed to cool naturally to room temperature to obtain the modified polyetheramine.

[0169] According to the provisions of GB / T 17671-1999 "Test Method for Strength of Cement Mortar" regarding the immersion test, the mass loss rate of the epoxy mortar measured in this comparative example during the 28-day underwater immersion test was 5% to 6%.

[0170] Comparative Example 3

[0171] Compared to Example 1, all other conditions remained unchanged in this comparative example, except for the composition of the epoxy resin:

[0172] The epoxy mortar contains only one type of bisphenol F epoxy resin, EPIKOTE862, in 30 parts by weight. The weight parts of other components and the preparation process remain unchanged.

[0173] According to the provisions of GB / T 17671-1999 "Test Method for Strength of Cement Mortar" regarding immersion test, the mass loss rate of epoxy mortar measured in this comparative example was 5% to 6% in multiple 28-day underwater immersion tests.

[0174] Comparative Example 4

[0175] Compared to Example 1, all other conditions remained unchanged in this comparative example, except for the composition of the epoxy resin:

[0176] The epoxy resin consists of bisphenol A type epoxy resin E-51 (21 parts) and bisphenol F type epoxy resin EPIKOTE862 (9 parts), with the weight parts of other components and the preparation process remaining unchanged.

[0177] According to the provisions of GB / T 17671-1999 "Test Method for Strength of Cement Mortar" regarding immersion test, the mass loss rate of epoxy mortar measured in this comparative example was 5% to 6% in multiple 28-day underwater immersion tests.

[0178] Comparative Example 5

[0179] Compared to Example 1, this comparative example retains all other conditions except that the modified polyamide in the modified curing agent is replaced with a commonly used commercially available polyamide, namely T31 polyamide curing agent. The weight parts of other components and the preparation process remain unchanged.

[0180] According to the provisions of GB / T 17671-1999 "Test Method for Strength of Cement Mortar" regarding immersion test, the mass loss rate of epoxy mortar measured in this comparative example was 7% to 8% in multiple 28-day underwater immersion tests.

[0181] Comparative Example 6

[0182] Compared to Example 1, all other conditions remained unchanged in this comparative example except that the modified polyetheramine in the modified curing agent was replaced with a commonly used commercially available polyamide curing agent, namely 593 polyamide curing agent. The weight parts of other components and the preparation process remained unchanged.

[0183] According to the provisions of GB / T 17671-1999 "Test Method for Strength of Cement Mortar" regarding immersion test, the mass loss rate of epoxy mortar measured in this comparative example was 7% to 8% in multiple 28-day underwater immersion tests.

[0184] Comparative Example 7

[0185] Compared to Example 1, this comparative example keeps all other conditions unchanged except that the modified polyetheramine in the modified curing agent is replaced with a mixture of modified polyetheramine (3.5 parts) and epichlorohydrin (1.5 parts), while the weight parts of other components and the preparation process remain unchanged.

[0186] According to the provisions of GB / T 17671-1999 "Test Method for Strength of Cement Mortar" regarding immersion test, the mass loss rate of epoxy mortar measured in this comparative example was 6% to 7% in multiple 28-day underwater immersion tests.

[0187] Comparative Example 8

[0188] Compared to Example 1, all other conditions remained the same in this comparative example except that the toughening agent dibutyl ester was no longer added to the preparation of the epoxy mortar, while the weight parts of other components and the preparation process remained unchanged.

[0189] According to the provisions of GB / T 17671-1999 "Test Method for Strength of Cement Mortar" regarding immersion test, the mass loss rate of epoxy mortar measured in this comparative example was 4% to 6% in multiple 28-day underwater immersion tests.

[0190] Analysis example

[0191] Epoxy mortar specimens were prepared using the component ratios and preparation methods of Examples 1 and 1-8. The slump, initial and final setting times, wet interface bond strength, and unconfined compressive strength (1d, 3d, 7d, 10d, 28d) of the epoxy mortar were tested according to the test methods in JC / T2630-2021, GB / T1346-2011, GB / T 50081-2019, and GB / T 17671-2021.

[0192] (1) Effect of epoxy resin (Example 1 and Comparative Examples 1 and 2).

[0193] The epoxy mortar prepared with a single type of epoxy resin (comparison of Example 1 and Comparative Example 1) has lower compressive strength, bond strength and fluidity than the modified epoxy mortar in Example 1, but it shortens the initial setting and final setting time, which helps to accelerate curing during pouring.

[0194] Two-component epoxy resins composed of bisphenol A and bisphenol F epoxy resins (comparison of Example 1 and Comparative Example 2) exhibit reduced compressive and bond strength, but increased setting time and fluidity. By incorporating toughening epoxy resins into bisphenol A and bisphenol F epoxy resins, the overall performance of the epoxy mortar is significantly improved.

[0195] (2) Effect of modified curing agent (Example 1 and Comparative Examples 1, 2, 5, 6).

[0196] Comparing Example 1 and Comparative Examples 1 and 2, changing the composition of the modified polyamide and modified polyetheramine compounds in the modified curing agent alters the mechanical and flow properties of the epoxy mortar. Specifically, the conversion of ethylenediamine in the modified polyamide to diethylenetriamine increases the setting time of the epoxy mortar. Furthermore, the modified polyetheramine, prepared by the reaction of vinyl polyether, DGEBA-type epoxy resin, lauric acid, and γ-aminopropyltriethoxysilane, results in a decrease in unconfined compressive strength when preparing epoxy mortar, indicating a weakened reinforcement effect on the door groove.

[0197] Compared with Comparative Examples 5 and 6, Example 1 shows that replacing the modified polyamide or modified polyetheramine with commercially available polyamide curing agents (T31 polyamide curing agent and 593 polyamide curing agent) results in epoxy mortar with lower compressive strength and bond strength than epoxy mortar made with self-made modified curing agents, and the fluidity does not meet industry standards.

[0198] (3) Effect of dibutyl ester content (Example 1 and Comparative Example 8).

[0199] When dibutyl ester, used as a toughening agent, is not added to epoxy mortar, the compressive strength and wet interface bond strength of the epoxy mortar solidified body are reduced by more than 25%.

[0200] The performance test tables of the epoxy mortars prepared in Example 1 and Comparative Examples 1 to 8 are shown in Table 1.

[0201] Table 1 Performance Test Table for Epoxy Mortar

[0202]

[0203] The modified epoxy mortar of this invention possesses excellent properties such as high strength, impact resistance, strong water dispersibility, and good fluidity. It effectively improves sealing performance and load-bearing capacity in the sealing of gate slots in diversion tunnels, and can resist non-uniform stress and cavitation damage under high water head pressure.

[0204] The formulation of Example 1 achieves optimal strength, flowability, and adhesion properties, demonstrating the reliability and superiority of this formulation in practical applications.

[0205] The above technical solutions of the present invention are merely preferred embodiments of the present invention and do not limit the patent scope of the present invention. All equivalent structural transformations made using the contents of the present invention under the technical concept of the present invention, or direct / indirect applications in other related technical fields, are included in the patent protection scope of the present invention.

Claims

1. An epoxy mortar, characterized in that, The raw material composition includes epoxy resin, modified curing agent, toughening agent, cementitious material and aggregate in a mass ratio of 25%~40%, 20~30%, 2~5%, 5~20% and 30~50% respectively; The modified curing agent comprises triethylenetetramine, modified polyamide, modified polyetheramine, nano-silica, and an anti-water dispersing agent in a mass ratio of 1:1.5~2:0.5~1:0.2~0.5:0.05~0.

2. The preparation of the modified curing agent includes the following steps: The triethylenetetramine was mixed with the modified polyamide and subjected to a first heat treatment at 120°C to 150°C to obtain an amine-amide pre-crosslinking intermediate. The modified polyetheramine is mixed with the amine-amide pre-crosslinking intermediate and subjected to a second heat treatment at 160°C to 180°C to obtain the polyetheramine modified crosslinking intermediate; The nano-silica is mixed with the polyetheramine modified crosslinking intermediate and subjected to a third heat treatment at 180℃~200℃ to obtain a nano-silica composite crosslinked body. Under heat preservation conditions, a mixture of the nano-silica composite crosslinker and the anti-water dispersing agent is obtained and cooled to room temperature to obtain the modified curing agent; The modified polyetheramine comprises polyetheramine, stearic acid, epichlorohydrin, and silane coupling agent in a mass ratio of 4~6:1~3:1~3:

1. The preparation of the modified polyetheramine includes the following steps: mixing the polyetheramine with the epichlorohydrin and subjecting it to a fourth heat treatment at 60℃~80℃ to obtain an epoxy-grafted polyetheramine intermediate. Under heat preservation conditions, the epoxy-grafted polyetheramine intermediate is mixed with the stearic acid. After the mixture is completely mixed, it is subjected to a fifth heat treatment at 90°C to 100°C to obtain the esterified polyetheramine modified body. The esterified polyetheramine modified body is mixed with the silane coupling agent. After the reaction is completed under heat preservation conditions, it is cooled to room temperature to obtain the modified polyetheramine. The preparation of the modified polyamide includes the following steps: mixing ethylenediamine and terephthalic acid in a mass ratio of 1:0.62~1.85, subjecting the mixture to a sixth heating treatment to induce a polycondensation reaction, thereby obtaining the modified polyamide.

2. The epoxy mortar according to claim 1, characterized in that, The epoxy resin is prepared by mixing bisphenol A type epoxy resin, bisphenol F type epoxy resin and toughened epoxy resin; The mass ratio of the bisphenol A type epoxy resin, the bisphenol F type epoxy resin, and the toughened epoxy resin is 4~6:2~3:1~2.

3. The epoxy mortar according to claim 1, characterized in that, The epoxy mortar also includes a solvent; the solvent in the epoxy mortar accounts for 2% to 5% of the total mass; the solvent includes acetone; The toughening agent includes dibutyl phthalate, the cementitious material includes PO425 cement, and the aggregate includes marble medium sand.

4. The epoxy mortar according to claim 1, characterized in that, The nano-silica has a particle size of 20-50 nm and a specific surface area of ​​200-350 m² / g.

5. A method for preparing epoxy mortar as described in any one of claims 1 to 4, characterized in that, In the raw material composition of the epoxy mortar, the mass percentages of the epoxy resin, the modified curing agent, the toughening agent, the cementitious material, and the aggregate are 25%~40%, 20%~30%, 2%~5%, 5%~20%, and 30%~50%, respectively. The preparation process of the epoxy mortar includes the following steps: The cementitious material and the aggregate are mixed to obtain a dry cement mortar mix; The epoxy resin, the toughening agent, and the solvent are mixed to obtain an epoxy resin mixture. The modified curing agent, the epoxy resin mixture, and the cement mortar dry mix are mixed to obtain the epoxy mortar; the mass ratio of the triethylenetetramine, the modified polyamide, the modified polyetheramine, the nano silica, and the anti-water dispersibility agent in the modified curing agent is 1:1.5~2:1:0.5~1:0.2~0.5:0.05~0.

2.

6. The application of epoxy mortar as described in any one of claims 1 to 4 in the field of water conservancy engineering.

7. The application of epoxy mortar as described in any one of claims 1 to 4 in the sealing and reinforcement of gate slots in diversion tunnels.

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