A nano-based antifreeze and anti-seepage coagulum and its preparation method and application

Abstract

The present invention relates to the technical field of building materials, and particularly relates to a nano-based frost and impermeability resistant coagulum and its preparation method and application. The nano-based frost and impermeability resistant coagulum is composed of Group A and Group B. The raw materials of Group A are composed of the following parts by weight: 40-70 parts by weight of epoxy resin, 10-20 parts by weight of rubber-modified epoxy resin, 8-15 parts by weight of multi-functional epoxy resin, 2-7 parts by weight of dispersant, and 8-15 parts by weight of filler; the raw materials of Group B are composed of the following parts by weight: 3-8 parts by weight of emery, 1-3 parts by weight of anti-increasing agent, 1-3 parts by weight of coupling agent, 4-8 parts by weight of toughening agent, 8-14 parts by weight of curing agent, 4-8 parts by weight of nano promoter, and 6-10 parts by weight of functional auxiliary agent. The nano-based frost and impermeability resistant coagulum prepared by the present invention has good impermeability and frost resistance effects when applied to concrete, and can also reduce the chloride ion migration rate, and can be used as a repair material in a special concrete bridge guardrail.

Description

Technical Field

[0001] The present invention relates to the technical field of engineering materials, and particularly relates to a nano-based anti-freezing and anti-seepage coagulum, a preparation method thereof and an application thereof. Background Art

[0002] The bridge anti-collision guardrail is one of the important components of a bridge. Maintaining its integrity is of great significance for ensuring the stability of the bridge structure and the safety of vehicle driving.

[0003] The anti-collision guardrails of bridges built in the early stage generally have design defects. The thickness of their concrete protective layers is mostly less than 3 cm, which can no longer meet the existing code requirements. Especially in areas where deicing salts are used, the code requires that the thickness of the protective layer of the anti-collision guardrail should not be less than 4 cm. With the rapid growth of traffic volume and the continuous increase of vehicle axle loads, before many bridges reach their designed service lives, their cement concrete structures have shown varying degrees of deterioration, damage and decline in service performance, and urgent repairs are needed.

[0004] During the repair construction process, it was found that the thickness of the protective layer of the existing anti-collision guardrails is generally less than 2 cm, and in some local areas, it is even less than 1 cm, which seriously affects the durability of the structure. After analysis, the main reasons for this problem are as follows: First, during the construction process of the original bridge, when pouring concrete, the steel bar cage tilted outwards due to the accumulation of aggregates; second, when construction workers adjusted the position of the formwork to ensure the aesthetic appearance of the guardrail line, they failed to synchronously adjust the steel bar positioning. After long-term use, the steel bars in these parts with too thin protective layers expand due to corrosion, and finally lead to damage phenomena such as cracking and peeling of the concrete surface.

[0005] The road surface is continuously scoured and worn by rainwater and water flow, causing damage to the bottom structure. In addition, when there is snow on the road surface in winter, the brine generated by using snow melting agents seeps into the interior of the cement concrete. The long-term salt corrosion causes the cement mortar to powder, form a white paste when mixed with water and float up, resulting in a decrease in the overall compressive strength of the concrete and surface peeling. For bridge guardrails, snow melting agents are strong corrosive agents that can penetrate into the interior of the bridge cement and corrode the steel bar cage. Due to the continuous downward penetration of the brine, cracks and peeling gradually appear in the concrete at the root of the guardrail, the steel bars are exposed and corroded. This phenomenon is commonly known as "root rot", which not only directly affects the safe operation of the project, but may also cause more serious structural problems, and the subsequent maintenance and reinforcement costs are extremely high.

[0006] Polycarboxylate superplasticizer is the latest generation of high-performance superplasticizer, and there are currently a large number of applications in the field of cement concrete. Based on different cements and different construction requirements, various polycarboxylate superplasticizers with different functions have been developed, such as high-efficiency water-reducing type, slump-retention type, early-strength type, etc. Developing a polycarboxylate admixture for roller-compacted concrete that integrates multiple functions is still a technical challenge. Summary of the Invention

[0007] In view of the deficiencies in the above-mentioned existing technologies, the present invention provides a nano-based anti-freezing and anti-seepage coagulating fat and its preparation method and application.

[0008] To solve the above technical problems, the technical solution adopted by the present invention is as follows:

[0009] A nano-based anti-freezing and anti-seepage coagulating fat, which is composed of Group A and Group B. The raw materials of Group A are composed of the following parts by weight: 40-70 parts by weight of epoxy resin, 10-20 parts by weight of rubber-modified epoxy resin, 8-15 parts by weight of polyfunctional epoxy resin, 2-7 parts by weight of dispersant, and 8-15 parts by weight of filler; the raw materials of Group B are composed of the following parts by weight: 3-8 parts by weight of emery, 1-3 parts by weight of anti-increasing agent, 1-3 parts by weight of coupling agent, 4-8 parts by weight of toughening agent, 8-14 parts by weight of curing agent, 4-8 parts by weight of nano-promoter, and 6-10 parts by weight of functional auxiliary agent, and the functional auxiliary agent is a modified nano-silica composite.

[0010] The weight ratio of Group A to Group B is (1.2-2.8):1.

[0011] The polyfunctional epoxy resin is at least one of polyphenol-type glycidyl ether epoxy resin, bisphenol A-type epoxy resin, hydrogenated bisphenol A-type epoxy resin, bisphenol S-type epoxy resin, and stilbene-type epoxy resin.

[0012] The dispersant is any one of sodium dodecyl benzene sulfonate, octylphenol polyoxyethylene ether, and fatty acid monoethanolamide; the filler is any one of silica, calcium carbonate, talcum powder, alumina, and montmorillonite; the anti-increasing agent is at least one of cellulose hydroxypropyl methyl ether and fiber and non-ionic polyacrylamide; the coupling agent is one or any combination of silane coupling agent, titanate coupling agent, and aluminate coupling agent; the toughening agent is one or any combination of polyethylene glycol, polypropylene glycol, polyethylene glycol monomethyl ether, polyethylene glycol dimethyl ether, and tetraethylene glycol monooctyl ether; the curing agent is a fatty polyamine-type curing agent, an isocyanate curing agent, an acid anhydride-type curing agent, and an aromatic amine-type curing agent; the nano-promoter is tetrabutylthiuram disulfide.

[0013] The preparation method of the rubber-modified epoxy resin is as follows: Under a nitrogen atmosphere, 3-6 parts by weight of hydroxyl-terminated liquid nitrile rubber and 0.5-2 parts by weight of 2,4-toluene diisocyanate are mixed and reacted at 75-100°C for 2-6 hours to obtain a prepolymer; 8-16 parts by weight of epoxy resin are added and heated to 90-110°C, and vacuum is drawn and the reaction is carried out under insulation for 3-6 hours to obtain the rubber-modified epoxy resin.

[0014] Hydroxynitrile rubber modified epoxy resin. The hydroxynitrile rubber has a highly polar -CN group, which can be well dispersed in the epoxy resin matrix during the prepolymerization reaction and curing reaction, improving the toughness of the modified epoxy resin.

[0015] Adding nano-silica into the nano-based antifreeze and impermeable coagulant can effectively eliminate the negative impact of epoxy resin emulsion on cement-based materials. Nano-silica can fill the micropores and fine cracks of the material, effectively improving the microscopic phenomenon of the cement paste, reducing the number of pores. Therefore, it can be used as a densifier, which can promote cement hydration, accelerate the formation of calcium silicate hydrate gel (C-S-H), optimize the pore structure to make up for the strength loss, and improve the frost resistance of the material. However, silica itself does not participate in the cross-linking reaction of epoxy resin, has poor dispersibility in the matrix, and is not well compatible with the epoxy resin matrix. If nano-silica is directly added, it cannot directly enhance the cross-linking density due to easy agglomeration. Therefore, it needs to be modified.

[0016] After modification, the hydrophobicity of silica is improved, and its compatibility with other components of the epoxy resin matrix is also correspondingly improved. It can effectively prevent the penetration of water molecules, further improve the compactness strength of concrete, improve the pore structure, thus reducing the penetration channels and further improving the impermeability of concrete.

[0017] Although adding modified nano-silica can effectively solve the impermeability problem, it cannot solve the frost resistance problem at the same time. Especially when used for the reinforcement of bridges in the extremely cold northern regions, snow can penetrate into the interior of bridge cement and corrode its steel skeleton. Over time, cracks and spalling will appear in the concrete at the root of the guardrail, and the steel bars will be exposed and corroded, commonly known as "root rot". Therefore, there is an urgent need to provide a multifunctional additive that can resist both impermeability and frost resistance to further expand its application range.

[0018] The present invention polymerizes 2-hydroxy-1,3-propylene diacrylate, methallyl alcohol polyoxyethylene ether and acrylic acid to provide relatively long side chains and hydrophilic groups for the polycarboxylate superplasticizer; then by introducing graphene oxide that can fill the micropores and capillary pores in concrete, reduce the porosity, lower the permeability, increase the steric hindrance, enhance the dispersibility, and graphene oxide can reduce the free water in concrete, lower the expansion pressure in freeze-thaw cycles, further enhance its density, reduce the expansion of microcracks caused by freeze-thaw cycles, enhance the impermeability and frost resistance, so that the prepared polycarboxylate superplasticizer has a certain anti-shrinkage effect and can play a role in frost resistance in areas with large day-night temperature differences.

[0019] The preparation method of the modified nano-silica composite is as follows:

[0020] S1: nano-silica and ethanol aqueous solution are mixed and ultrasonicated; silane coupling agent and ammonia water are added, heated and stirred to obtain silane-modified nano-silica;

[0021] S2, acrylic acid, 2-hydroxy-1,3-propylene glycol acrylate, methyl allyl alcohol polyoxyethylene ether and water are uniformly mixed, and graphene oxide is added and stirred; thioglycolic acid and ammonium persulfate are then added and heated, and the solvent is recovered by vacuum distillation to obtain a polycarboxylate water reducer containing graphene;

[0022] S3. Take the above-mentioned silane-modified nano-silica and water, mix them with ultrasound, add the above-mentioned polycarboxylate water-reducing agent containing graphene and ammonium persulfate, heat, and freeze-dry to obtain a modified nano-silica composite.

[0023] The present invention incorporates graphene oxide during the preparation of a polycarboxylate water-reducing agent because it can increase the yield of hydrated calcium silicate in concrete, promote the formation and arrangement of cement hydrate crystals, improve the structure of the cement-aggregate interface, reduce porosity, and increase density. While improving the microstructure, graphene oxide also enhances concrete properties such as compressive strength, tensile strength, impermeability, resistance to chloride ion corrosion, and freeze-thaw resistance. This avoids the problem of directly adding a graphene oxide dispersion alone, which would result in large clumps due to long-term storage. Once incorporated into concrete, the aggregated graphene oxide becomes unevenly distributed within the concrete, creating numerous local pores and degrading the concrete's performance.

[0024] The modified nano-silica composite prepared by the present invention not only has the anti-seepage performance of silica, but also has the anti-freeze and anti-seepage performance of a polycarboxylate water-reducing agent containing graphene. The inventor effectively combines the two to prepare a multifunctional modified nano-silica composite. After adding the polycarboxylate water-reducing agent containing graphene to the concrete system, the number of capillaries in the concrete can be greatly reduced, so that the concrete forms a highly dense microstructure, further reducing the internal defects in the concrete, and having good anti-seepage performance, high and low temperature resistance, and effectively hindering the migration of chloride ions; the modified nano-silica not only has improved hydrophobicity, but also has correspondingly improved compatibility with other components of the epoxy resin matrix, which can effectively prevent the penetration of water molecules, while further improving the concrete density strength, improving the pore structure, thereby reducing the penetration channel, and then greatly improving the anti-freeze and anti-seepage performance of the concrete, thereby effectively improving the durability of the bridge guardrail.

[0025] Preferably, the preparation method of the modified nano-silica composite is as follows:

[0026] S1: Take 3 - 6 parts by weight of nano - silica and 40 - 60 parts by weight of 50 - 70wt% ethanol aqueous solution, mix them, and ultrasonicate for 20 - 50 min at a temperature of 35 - 50 °C, an ultrasonic power of 100 - 300 W, and an ultrasonic frequency of 40 - 70 kHz; add 0.8 - 2 parts by weight of silane coupling agent and 0.5 - 2 parts by weight of ammonia water with a concentration of 20 - 30wt%, stir at 30 - 50 °C and 300 - 500 rpm for 4 - 8 h, cool, centrifuge, wash, and dry to obtain silane - modified nano - silica;

[0027] S2: Mix 2 - 6 parts by weight of acrylic acid, 3 - 7 parts by weight of 2 - hydroxy - 1,3 - propanediol 2 - acrylate, 20 - 40 parts by weight of methallyl alcohol polyoxyethylene ether, and 60 - 120 parts by weight of water uniformly, add 0.1 - 0.4 parts by weight of graphene oxide, stir at 20 - 40 °C and 300 - 500 rpm for 4 - 8 h; then add 0.3 - 0.8 parts by weight of mercaptoacetic acid and 0.3 - 0.8 parts by weight of ammonium persulfate; keep warm at 50 - 70 °C and 300 - 500 rpm for 1 - 4 h, and recover the solvent by vacuum distillation to obtain a polycarboxylate water - reducing agent containing graphene;

[0028] S3: Take 2 - 5 parts by weight of the above - mentioned silane - modified nano - silica and 40 - 100 parts by weight of water, ultrasonicate at an ultrasonic power of 100 - 300 W and an ultrasonic frequency of 40 - 70 kHz for 20 - 50 min, add 3 - 7 parts by weight of the above - mentioned polycarboxylate water - reducing agent containing graphene and 0.1 - 0.5 parts by weight of ammonium persulfate, stir at 70 - 85 °C and 400 - 800 rpm for 50 - 90 min, and freeze - dry to obtain a modified nano - silica composite.

[0029] The silane coupling agent is at least one of 3 - [bis(2 - hydroxyethyl)amino]propane - triethoxysilane, N - (3 - acryloyloxy - 2 - hydroxypropyl) - 3 - aminopropyltriethoxysilane, and N - (6 - aminohexyl)aminomethyltriethoxysilane.

[0030] The preparation method of the nano - based antifreeze and impermeable coagulant fat includes the following steps:

[0031] (1) First, weigh each component raw material;

[0032] (2) Mix epoxy resin, rubber - modified epoxy resin, multi - functional epoxy resin, dispersant, and filler, and stir at 40 - 60 °C and 4000 - 1000 rpm for 20 - 50 min to obtain component A;

[0033] (3) Then, stir carborundum, anti - thickening agent, coupling agent, toughening agent, and functional additive at room temperature and 1000 - 2000 rpm for 0.5 - 2 h, and finally add curing agent and nano - promoter, and continue to stir for 15 min to obtain component B;

[0034] (4) Component A and component B are mixed and stirred evenly to obtain a nano-based antifreeze and anti-seepage gel.

[0035] The nano-based antifreeze and anti-seepage gel is used in concrete bridge guardrails, pavements, and construction projects.

[0036] The nano-based antifreeze and anti-seepage gel is used as a repair material in special concrete bridge guardrails, road surfaces, and construction projects.

[0037] Beneficial effects of the present invention: The present invention provides a nano-based antifreeze and anti-seepage gel and its preparation method and application, adopts specific components with specific contents to achieve overall better interaction. This product has antifreeze and anti-seepage properties as well as resistance to chloride ion migration. It has good crack resistance when used in concrete and is particularly suitable for bridge reinforcement.

[0038] The present invention adds functional additives to the nano-based antifreeze and anti-seepage gel, which can greatly reduce the number of capillaries in concrete, form a highly dense microstructure in the concrete, further reduce internal defects in the concrete, improve the compact strength of the concrete, improve the pore structure, have good anti-seepage performance, effectively hinder the migration of chloride ions, and thus greatly improve the antifreeze and anti-seepage performance of the concrete, thereby effectively improving the durability of bridge guardrails in complex environmental conditions such as high cold and humidity, extending the service life of hydraulic concrete structures in freeze-thaw alternating environments, and reducing later maintenance costs, achieving multiple goals at one stroke, and being suitable for popularization and use. DETAILED DESCRIPTION

[0039] The above content of the present invention will be further described in detail below in conjunction with specific embodiments, but it should not be understood that the scope of the above subject matter of the present invention is limited to the following embodiments.

[0040] Introduction of some raw materials in this application:

[0041] Epoxy resin was purchased from Hubei Zhenzhengfeng New Materials Co., Ltd. with the brand name MF-4101H.

[0042] Hydrogenated bisphenol A epoxy resin was purchased from Green Union (Jining) Chemical Technology Co., Ltd., model 5001.

[0043] Cellulose hydroxypropyl methyl ether was purchased from cellulose hydroxypropyl methyl ether, with a viscosity of 250,000 Pa·s.

[0044] Octylphenol polyoxyethylene ether was purchased from Shanghai Zhenlishi Network Technology Co., Ltd., model DOWFAX X-405.

[0045] Polyethylene glycol dimethyl ether was purchased from Anhui Nanmu Chemical Co., Ltd., model SF-260 / 400.

[0046] The hydroxyl-terminated liquid nitrile rubber was purchased from Jining Tangyi Chemical Co., Ltd., with the model SH-820.

[0047] The methallyl alcohol polyoxyethylene ether was purchased from Liaoning Shengxin Technology Co., Ltd., with the model SX-702.

[0048] The nano-silica was purchased from Qinghe Xingxin New Material Technology Co., Ltd., with a particle size / mesh number of 15,000 meshes.

[0049] The graphene oxide was purchased from Hebei Ruihuang Metal Materials Co., Ltd., with a particle size / mesh number of 35,000 meshes.

[0050] Example 1

[0051] A nano-based anti-freezing and anti-seepage coagulant is composed of Group A and Group B. The weight ratio of Group A to Group B is 2:1. Group A consists of the following raw materials in parts by weight: 50 parts by weight of epoxy resin, 15 parts by weight of rubber-modified epoxy resin, 10 parts by weight of multi-functional epoxy resin, 5 parts by weight of dispersant, and 10 parts by weight of silica; Group B consists of the following raw materials in parts by weight: 4 parts by weight of emery, 2 parts by weight of anti-increment agent, 2 parts by weight of coupling agent, 6 parts by weight of toughening agent, 10 parts by weight of curing agent, 6 parts by weight of nano-accelerator, and 8 parts by weight of functional additive.

[0052] The nano-accelerator is tetrabutylthiuram disulfide.

[0053] The multi-functional epoxy resin is hydrogenated bisphenol A epoxy resin.

[0054] The anti-increment agent is hydroxypropyl methylcellulose.

[0055] The dispersant is octylphenol polyoxyethylene ether.

[0056] The coupling agent is silane coupling agent KH-550.

[0057] The toughening agent is polyethylene glycol dimethyl ether.

[0058] The curing agent is tetraethylenepentamine.

[0059] The preparation method of the rubber-modified epoxy resin is as follows: Under a nitrogen atmosphere, 4 parts by weight of hydroxyl-terminated liquid nitrile rubber is mixed with 1 part by weight of 2,4-toluene diisocyanate, and the mixture is reacted at 90 °C for 4 h to obtain a prepolymer; 12 parts by weight of epoxy resin is added and heated to 100 °C, and the reaction is carried out under vacuum for 4 h to obtain the rubber-modified epoxy resin.

[0060] The functional additive is nano-silica.

[0061] The preparation method of the nano-based anti-freezing and anti-seepage coagulant is as follows:

[0062] (1) Weigh each component raw material first;

[0063] (2) Mix epoxy resin, rubber-modified epoxy resin, multi-functional epoxy resin, dispersant, and silica, and stir at 50 °C and 6000 rpm for 30 min to obtain Component A;

[0064] (3) Then mix emery, anti-blocking agent, coupling agent, toughening agent, and functional additives, stir at room temperature and 1200 rpm for 1 h, and finally add curing agent and nano-promoter, and continue to stir for 15 min to obtain Component B;

[0065] (4) Mix Component A and Component B evenly by stirring to obtain nano-based anti-freezing and anti-seepage coagulant grease.

[0066] Example 2

[0067] A nano-based anti-freezing and anti-seepage coagulant grease is composed of Component A and Component B. The weight ratio of Component A to Component B is 2:1. Component A is composed of the following raw materials in parts by weight: 50 parts by weight of epoxy resin, 15 parts by weight of rubber-modified epoxy resin, 10 parts by weight of multi-functional epoxy resin, 5 parts by weight of dispersant, and 10 parts by weight of silica; Component B is composed of the following raw materials in parts by weight: 4 parts by weight of emery, 2 parts by weight of anti-blocking agent, 2 parts by weight of coupling agent, 6 parts by weight of toughening agent, 10 parts by weight of curing agent, 6 parts by weight of nano-promoter, and 8 parts by weight of functional additives.

[0068] The nano-promoter is tetrabutylthiuram disulfide.

[0069] The multi-functional epoxy resin is hydrogenated bisphenol A epoxy resin.

[0070] The anti-blocking agent is hydroxypropyl methylcellulose.

[0071] The dispersant is octylphenol polyoxyethylene ether.

[0072] The coupling agent is silane coupling agent KH-550.

[0073] The toughening agent is polyethylene glycol dimethyl ether.

[0074] The curing agent is tetraethylenepentamine.

[0075] The preparation method of the rubber-modified epoxy resin is as follows: Under a nitrogen atmosphere, mix 4 parts by weight of hydroxyl-terminated liquid nitrile rubber and 1 part by weight of 2,4-toluene diisocyanate, place it at 90 °C and react for 4 h to obtain a prepolymer; add 12 parts by weight of epoxy resin and heat to 100 °C, evacuate and keep the temperature for reaction for 4 h to obtain rubber-modified epoxy resin.

[0076] The functional additive is modified nano-silica, and the preparation method of the modified nano-silica is as follows: Take 4 parts by weight of nano-silica and 50 parts by weight of 60wt% ethanol aqueous solution, mix them, and ultrasonicate for 30 min at a temperature of 40°C, an ultrasonic power of 200 W, and an ultrasonic frequency of 60 kHz; add 1.2 parts by weight of silane coupling agent and 1 part by weight of 25wt% ammonia water, stir at 40°C and 400 rpm for 6 h, cool, centrifuge, wash, and dry to obtain the modified nano-silica.

[0077] The silane coupling agent is 3-[bis(2-hydroxyethyl)amino]propane-triethoxysilane.

[0078] The preparation method of the nano-based antifreeze and impermeable coagulant is as follows:

[0079] (1) First, weigh each component raw material;

[0080] (2) Mix epoxy resin, rubber-modified epoxy resin, multi-functional epoxy resin, dispersant, and silica, and stir at 50°C and 6000 rpm for 30 min to obtain Component A; [[ID= thirteen]]

[0081] (3) Then, stir carborundum, anti-blocking agent, coupling agent, toughening agent, and functional additive at room temperature and 1200 rpm for 1 h, and finally add curing agent and nano-promoter, and continue to stir for 15 min to obtain Component B;

[0082] (4) Mix Component A and Component B evenly by stirring to obtain the nano-based antifreeze and impermeable coagulant.

[0083] Example 3 [[ID= twenty-three]]

[0084] A nano-based antifreeze and impermeable coagulant is composed of Component A and Component B. The weight ratio of Component A to Component B is 2:1. Component A is composed of the following raw materials in parts by weight: 50 parts by weight of epoxy resin, 15 parts by weight of rubber-modified epoxy resin, 10 parts by weight of multi-functional epoxy resin, 5 parts by weight of dispersant, and 10 parts by weight of silica; Component B is composed of the following raw materials in parts by weight: 4 parts by weight of carborundum, 2 parts by weight of anti-blocking agent, 2 parts by weight of coupling agent, 6 parts by weight of toughening agent, 10 parts by weight of curing agent, 6 parts by weight of nano-promoter, and 8 parts by weight of functional additive.

[0085] The nano-promoter is tetrabutylthiuram disulfide.

[0086] The multi-functional epoxy resin is hydrogenated bisphenol A type epoxy resin.

[0087] The anti-blocking agent is cellulose hydroxypropyl methyl ether.

[0088] The dispersant is octylphenol polyoxyethylene ether.

[0089] The coupling agent is silane coupling agent KH-550.

[0090] The toughening agent is polyethylene glycol dimethyl ether.

[0091] The curing agent is tetraethylenepentamine.

[0092] The preparation method of the rubber-modified epoxy resin is as follows: Under a nitrogen atmosphere, 4 parts by weight of hydroxyl-terminated liquid nitrile rubber and 1 part by weight of 2,4-toluene diisocyanate are mixed and reacted at 90 °C for 4 h to obtain a prepolymer; 12 parts by weight of epoxy resin is added and heated to 100 °C, and vacuum is applied for heat preservation reaction for 4 h to obtain the rubber-modified epoxy resin.

[0093] The functional auxiliary agent is a modified nano-silica composite, and the preparation method of the modified nano-silica composite is as follows:

[0094] S1: 4 parts by weight of acrylic acid, 5 parts by weight of 2-hydroxy-1,3-propanediyl diacrylate, 30 parts by weight of methallyl alcohol polyoxyethylene ether and 80 parts by weight of water are mixed evenly, 0.2 part by weight of graphene oxide is added, and stirred at 30 °C and 400 rpm for 6 h; 0.5 part by weight of mercaptoacetic acid and 0.5 part by weight of ammonium persulfate are added; kept warm at 60 °C and 400 rpm for 2 h, and the solvent is recovered by reduced pressure distillation to obtain a polycarboxylate water reducing agent containing graphene.

[0095] S2: 3 parts by weight of nano-silica and 60 parts by weight of water are mixed, ultrasonicated at an ultrasonic power of 200 W and an ultrasonic frequency of 60 kHz for 30 min, 5 parts by weight of the above polycarboxylate water reducing agent containing graphene and 0.2 part by weight of ammonium persulfate are added, and stirred at 75 °C and 600 rpm for 60 min, and freeze-dried to obtain the modified nano-silica composite.

[0096] The preparation method of the nano-based antifreeze and impermeable coagulant is as follows:

[0097] (1) First, weigh each component raw material;

[0098] (2) Epoxy resin, rubber-modified epoxy resin, polyfunctional epoxy resin, dispersant, and silica are mixed and stirred at 50 °C and 6000 rpm for 30 min to obtain component A;

[0099] (3) Then, emery, anti-increasing agent, coupling agent, toughening agent, and functional auxiliary agent are stirred at room temperature and 1200 rpm for 1 h, and finally the curing agent and nano-promoter are added and stirred for another 15 min to obtain component B;

[0100] (4) Component A and component B are mixed and stirred evenly to obtain the nano-based antifreeze and impermeable coagulant.

[0101] Example 4

[0102] A nano-based antifreeze and anti-seepage coagulating fat, which is composed of Group A and Group B. The weight ratio of Group A to Group B is 2:1. Group A consists of the following raw materials in parts by weight: 50 parts by weight of epoxy resin, 15 parts by weight of rubber-modified epoxy resin, 10 parts by weight of multi-functional epoxy resin, 5 parts by weight of dispersant, and 10 parts by weight of silica; Group B consists of the following raw materials in parts by weight: 4 parts by weight of emery, 2 parts by weight of anti-thickening agent, 2 parts by weight of coupling agent, 6 parts by weight of toughening agent, 10 parts by weight of curing agent, 6 parts by weight of nano promoter, and 8 parts by weight of functional additive.

[0103] The nano promoter is tetrabutylthiuram disulfide.

[0104] The multi-functional epoxy resin is hydrogenated bisphenol A epoxy resin.

[0105] The anti-thickening agent is hydroxypropyl methylcellulose.

[0106] The dispersant is octylphenol polyoxyethylene ether.

[0107] The coupling agent is silane coupling agent KH-550.

[0108] The toughening agent is polyethylene glycol dimethyl ether.

[0109] The curing agent is tetraethylenepentamine.

[0110] The preparation method of the rubber-modified epoxy resin is as follows: Under a nitrogen atmosphere, 4 parts by weight of hydroxyl-terminated liquid nitrile rubber and 1 part by weight of 2,4-toluene diisocyanate are mixed and reacted at 90 °C for 4 h to obtain a prepolymer; 12 parts by weight of epoxy resin is added and heated to 100 °C, and the reaction is carried out under vacuum insulation for 4 h to obtain the rubber-modified epoxy resin.

[0111] The functional additive is a modified nano-silica composite, and the preparation method of the modified nano-silica composite is as follows:

[0112] S1: Take 4 parts by weight of nano-silica and 50 parts by weight of 60 wt% ethanol aqueous solution, and ultrasonicate for 30 min at a temperature of 40 °C, an ultrasonic power of 200 W, and an ultrasonic frequency of 60 kHz; add 1.2 parts by weight of silane coupling agent and 1 part by weight of 25 wt% ammonia water, stir at 40 °C and 400 rpm for 6 h, cool, centrifuge, wash, and dry to obtain silane-modified nano-silica;

[0113] S2. Mix 4 parts by weight of acrylic acid, 5 parts by weight of 2-hydroxy-1,3-propanediyl diacrylate, 30 parts by weight of methallyl alcohol polyoxyethylene ether and 80 parts by weight of water evenly, add 0.2 parts by weight of graphene oxide, and stir at 30 °C and 400 rpm for 6 h; then add 0.5 parts by weight of mercaptoacetic acid and 0.5 parts by weight of ammonium persulfate; keep warm at 60 °C and 400 rpm for 2 h, and recover the solvent by vacuum distillation to obtain a polycarboxylate water reducer containing graphene.

[0114] S3. Take 3 parts by weight of the above-mentioned silane-modified nano-silica and mix it with 60 parts by weight of water, ultrasonicate at an ultrasonic power of 200 W and an ultrasonic frequency of 60 kHz for 30 min, add 5 parts by weight of the above-mentioned polycarboxylate water reducer containing graphene and 0.2 parts by weight of ammonium persulfate, stir at 75 °C and 600 rpm for 60 min, and freeze-dry to obtain a modified nano-silica composite.

[0115] The silane coupling agent is 3-[bis(2-hydroxyethyl)amino]propane-triethoxysilane.

[0116] The preparation method of the nano-based antifreeze and impermeable coagulant fat is as follows:

[0117] (1) First, weigh each component raw material;

[0118] (2) Mix epoxy resin, rubber-modified epoxy resin, multi-functional epoxy resin, dispersant, and silica, and stir at 50 °C and 6000 rpm for 30 min to obtain component A;

[0119] (3) Then, stir emery, anti-blocking agent, coupling agent, toughening agent, and functional auxiliary agent at room temperature and 1200 rpm for 1 h, and finally add curing agent and nano-promoter, and continue to stir for 15 min to obtain component B;

[0120] (4) Mix component A and component B evenly by stirring to obtain nano-based antifreeze and impermeable coagulant fat.

[0121] Example 5

[0122] It is basically the same as Example 4, and the difference is that:

[0123] The functional auxiliary agent is a modified nano-silica composite, and the preparation method of the modified nano-silica composite is as follows:

[0124] S1. Take 4 parts by weight of nano-silica and mix it with 50 parts by weight of 60 wt% ethanol aqueous solution, ultrasonicate at a temperature of 40 °C, an ultrasonic power of 200 W, and an ultrasonic frequency of 60 kHz for 30 min; add 1.2 parts by weight of silane coupling agent and 1 part by weight of 25 wt% ammonia water, stir at 40 °C and 400 rpm for 6 h, cool, centrifuge, wash, and dry to obtain silane-modified nano-silica.

[0125] S2. Mix 4 parts by weight of acrylic acid, 5 parts by weight of 2-hydroxy-1,3-propanediol diacrylate, 30 parts by weight of methallyl alcohol polyoxyethylene ether and 80 parts by weight of water evenly, and stir at 30 °C and 400 rpm for 6 h; then add 0.5 parts by weight of mercaptoacetic acid and 0.5 parts by weight of ammonium persulfate; keep warm at 60 °C and 400 rpm for 2 h, and recover the solvent by vacuum distillation to obtain the polycarboxylate water reducer.

[0126] S3. Take 3 parts by weight of the above-mentioned silane-modified nano-silica and mix it with 60 parts by weight of water, ultrasonicate at an ultrasonic power of 200 W and an ultrasonic frequency of 60 kHz for 30 min, add 5 parts by weight of the above-mentioned polycarboxylate water reducer containing graphene and 0.2 parts by weight of ammonium persulfate, stir at 75 °C and 600 rpm for 60 min, and freeze-dry to obtain the modified nano-silica composite.

[0127] The silane coupling agent is 3-[bis(2-hydroxyethyl)amino]propane-triethoxysilane.

[0128] Example 6

[0129] It is basically the same as Example 4, the difference is that rubber-modified epoxy resin is not added: The A group consists of the following raw materials in parts by weight: 65 parts by weight of epoxy resin, 10 parts by weight of polyfunctional epoxy resin, and 5 parts by weight of dispersant.

[0130] Test Example 1

[0131] Freeze-thaw and impermeability test: Refer to the test method of the national standard GB / T 50082-2024 "Standard for Test Methods of Long-Term Performance and Durability of Concrete" to add the nano-based freeze-thaw and impermeable coagulum prepared in the above Examples 1-6 to the concrete. The formula of the concrete is: 50 parts by weight of cement, 18 parts by weight of fly ash, 100 parts by weight of sand, 160 parts by weight of kaolin, 30 parts by weight of water, and 15 parts by weight of the nano-based freeze-thaw and impermeable coagulum prepared in the above Examples 1-6; conduct freeze-thaw and impermeability tests on the concrete added with the nano-based freeze-thaw and impermeable coagulum prepared in Examples 1-6 respectively, with 5 groups tested in each group, and take the average value. The results are shown in Table 1.

[0132] Table 1 Test results of freeze-thaw and impermeability performance

[0133] Antifreeze ability Impermeability pressure (MPa) Example 1 F375 3.1 Example 2 F400 3.6 Example 3 F425 4.3 Example 4 F450 5.7 Example 5 F440 5.1 Example 6 F445 5.4

[0134] Test Example 2

[0135] Chloride ion migration coefficient test: The chloride ion migration coefficient test was carried out on the concrete added with the nano-based anti-freezing and anti-seepage coagulating fat prepared in Examples 1-6 respectively. The test was carried out with reference to the test method of the national standard GB / T 50082-2024 "Standard for Test Methods of Long-term Performance and Durability of Concrete". Five groups were tested for each group, and the average value was taken. The results are shown in Table 2.

[0136] Table 2 Test results of chloride ion migration coefficient

[0137] <![CDATA[Chloride ion migration coefficient D RCM (×10 -12 m 2 / s)]]> Example 1 11.5 Example 2 9.6 Example 3 7.3 Example 4 2.1 Example 5 3.2 Example 6 2.4

[0138] From the above results, it can be seen that the nano-based anti-freezing and anti-seepage coagulating fat prepared by the present invention has good anti-seepage and anti-freezing effects when applied to concrete, and at the same time can reduce the migration rate of chloride ions. By comparing Examples 1-4, it can be known that the modified nano-silica composite prepared by the present invention not only has the anti-seepage performance of silica, but also has a polycarboxylate water reducer containing graphene with anti-freezing and anti-seepage properties. The inventor effectively combines the two to prepare a multifunctional modified nano-silica composite. After adding the polycarboxylate water reducer containing graphene to the concrete system, the number of capillary pores in the concrete can be greatly reduced, forming a highly dense microstructure, further reducing the internal defects in the concrete, having good anti-seepage performance, high and low temperature resistance, and effectively hindering the migration of chloride ions; the modified nano-silica not only has improved hydrophobicity, but also has improved compatibility with other components of the epoxy resin matrix, can effectively prevent the penetration of water molecules, and at the same time further improves the compactness strength of the concrete, improves the pore structure, thereby reducing the penetration channels, and then greatly improving the anti-freezing and anti-seepage performance of the concrete, thus effectively enhancing the durability of the bridge guardrail.

[0139] Further comparing Examples 4-5, it can be known that graphene oxide is introduced in the preparation of the polycarboxylate water reducer in the present invention because graphene oxide can increase the yield of calcium silicate hydrate in the concrete, promote the formation and arrangement of cement hydration crystals, improve the structure of the cement stone and aggregate interface, reduce the porosity, and increase the density. While improving the microstructure, graphene oxide can also improve the compressive strength, tensile strength, anti-seepage property, anti-chloride ion erosion property, freeze-thaw resistance and other properties of the concrete. It avoids the problem that directly adding the graphene oxide dispersion alone will cause large agglomerates to form after long-term storage. After the agglomerated graphene oxide is incorporated into the concrete, it is unevenly distributed in the concrete, resulting in a large number of pores locally, causing a decline in the performance of the concrete.

[0140] Finally, comparing Example 4 and Example 6, in Example 6, hydroxy nitrile rubber modified epoxy resin was not added, and its effect would be relatively poor. The reason is that hydroxy nitrile rubber has a highly polar -CN group, which can be well dispersed in the epoxy resin matrix during the prepolymerization reaction and curing reaction, improving the toughness of the modified epoxy resin and thus enhancing the comprehensive performance of the concrete.

Claims

1. A nano-based antifreeze and impermeable coagulum fat, characterized in that, It consists of component A and component B. Component A is composed of the following raw materials in parts by weight: 40 - 70 parts by weight of epoxy resin, 10 - 20 parts by weight of rubber-modified epoxy resin, 8 - 15 parts by weight of hydrogenated bisphenol A epoxy resin, 2 - 7 parts by weight of dispersant, and 8 - 15 parts by weight of filler; Component B is composed of the following raw materials in parts by weight: 3 - 8 parts by weight of emery, 1 - 3 parts by weight of anti-blocking agent, 1 - 3 parts by weight of coupling agent, 4 - 8 parts by weight of toughening agent, 8 - 14 parts by weight of curing agent, 4 - 8 parts by weight of nano promoter, 6 - 10 parts by weight of functional additive, and the functional additive is a modified nano-silica composite; The preparation method of the modified nano-silica composite is as follows; S1: Take 3 - 6 parts by weight of nano-silica and 40 - 60 parts by weight of ethanol aqueous solution, mix them, and ultrasonicate for 20 - 50 min at a temperature of 35 - 50 °C; add 0.8 - 2 parts by weight of silane coupling agent and 0.5 - 2 parts by weight of ammonia water with a concentration of 20 - 30 wt%, and stir at 30 - 50 °C and 300 - 500 rpm for 4 - 8 h to obtain silane-modified nano-silica; S2: Mix 2 - 6 parts by weight of acrylic acid, 3 - 7 parts by weight of 2-hydroxy-1,3-propanediol 2-acrylate, 20 - 40 parts by weight of methallyl alcohol polyoxyethylene ether, and 60 - 120 parts by weight of water evenly; add 0.1 - 0.4 parts by weight of graphene oxide, and stir at 20 - 40 °C and 300 - 500 rpm for 4 - 8 h; then add 0.3 - 0.8 parts by weight of mercaptoacetic acid and 0.3 - 0.8 parts by weight of ammonium persulfate; keep warm at 50 - 70 °C and 300 - 500 rpm for 1 - 4 h to obtain a polycarboxylate water reducer containing graphene; S3: Take 2 - 5 parts by weight of the above silane-modified nano-silica and 40 - 100 parts by weight of water, mix and ultrasonicate, add 3 - 7 parts by weight of the above polycarboxylate water reducer containing graphene and 0.1 - 0.5 parts by weight of ammonium persulfate, stir at 70 - 85 °C and 400 - 800 rpm for 50 - 90 min, and freeze-dry to obtain the modified nano-silica composite; The epoxy resin is purchased from Hubei Zhenzhengfeng New Materials Co., Ltd., with the brand MF-4101H; the preparation method of the rubber-modified epoxy resin is as follows: Under a nitrogen atmosphere, mix 3 - 6 parts by weight of hydroxyl-terminated liquid nitrile rubber with 0.5 - 2 parts by weight of 2,4-toluene diisocyanate, place it at 75 - 100 °C and react for 2 - 6 h to obtain a prepolymer; add 8 - 16 parts by weight of epoxy resin, heat to 90 - 110 °C, evacuate and keep warm for reaction for 3 - 6 h to obtain rubber-modified epoxy resin.

2. The nano-based antifreeze and impermeable coagulating fat according to claim 1, characterized in that The weight ratio of component A to component B is (1.2 - 2.8):

1.

3. The nano-based anti-freezing and anti-seepage congealed fat according to claim 1, characterized in that, The dispersant is any one of sodium dodecylbenzenesulfonate, octylphenol polyoxyethylene ether, and fatty acid monoethanolamide; the filler is any one of silica, calcium carbonate, talcum powder, alumina, and montmorillonite; the anti-thickening agent is at least one of hydroxypropyl methylcellulose and fiber and non-ionic polyacrylamide; the coupling agent is one or any combination of silane coupling agents, titanate coupling agents, and aluminate coupling agents; the toughening agent is one or any combination of polyethylene glycol, polypropylene glycol, polyethylene glycol monomethyl ether, polyethylene glycol dimethyl ether, and tetraethylene glycol monooctyl ether; the curing agent is a fatty polyamine type curing agent, an acid anhydride type curing agent, or an aromatic amine type curing agent; the nano promoter is tetrabutylthiuram disulfide.

4. The nano-based antifreeze and impermeable congealing fat according to claim 1, characterized in that, The silane coupling agent is at least one of 3-[bis(2-hydroxyethyl)amino]propane-triethoxysilane, N-(3-acryloyloxy-2-hydroxypropyl)-3-aminopropyltriethoxysilane, and N-(6-aminohexyl)aminomethyltriethoxysilane.

5. The preparation method of the nano-based antifreeze and impermeable coagulum fat according to any one of claims 1-4, characterized in that, It includes the following steps: (1) First, weigh each component raw material; (2) Mix epoxy resin, rubber-modified epoxy resin, hydrogenated bisphenol A epoxy resin, dispersant, and filler, and stir at 40 - 60 °C and 4000 - 1000 rpm for 20 - 50 min to obtain Component A; (3) Then, stir carborundum, anti-thickening agent, coupling agent, toughening agent, and functional additive at room temperature and 1000 - 2000 rpm for 0.5 - 2 h. Finally, add the curing agent and nano promoter and continue stirring for 15 min to obtain Component B; (4) Mix Component A and Component B evenly to obtain the nano-based anti-freezing and anti-seepage coagulating fat.

6. Application of the nano-based anti-freezing and anti-seepage coagulating fat according to any one of claims 1 - 4 in construction engineering.

7. The application according to claim 6, characterized in that, The nano-based anti-freezing and anti-seepage coagulating fat is used as a repair material for construction engineering.