Concrete antifreeze aggregate, antifreeze concrete and preparation method

Abstract

This invention belongs to the field of building materials technology, specifically relating to a concrete antifreeze aggregate, antifreeze concrete, and its preparation method. This invention modifies river sand, the main component of concrete aggregate, and introduces functional components such as modified diatomaceous earth, succinic anhydride-polyvinyl alcohol composite material, and graphene oxide to prepare an antifreeze concrete aggregate. This reduces the aggregate's water absorption rate and crushing index, while achieving excellent freeze-thaw resistance, and is then applied to antifreeze concrete.

Description

Technical Field

[0001] This invention belongs to the field of building materials technology, specifically relating to a concrete antifreeze aggregate, antifreeze concrete, and its preparation method. Background Art

[0002] Sand and gravel aggregates constitute the largest proportion of concrete and are also its most stable component. To achieve high durability in concrete, the proportion of aggregates must be maximized while controlling or minimizing the proportion of paste, all while meeting workability requirements. The quality of aggregates directly affects the workability of fresh concrete, its volume stability, and ultimately, its durability. Aggregates are an upstream element in concrete quality control; poor-quality sand and gravel with high porosity and undesirable particle shape not only negatively impact the workability of the concrete mixture but also adversely affect its mechanical properties and durability.

[0003] Chinese patent (publication number CN116947350A) discloses a method for enhancing recycled concrete aggregate. This invention prepares concrete aggregate by pre-treating waste concrete, which can improve the utilization rate of waste and reduce the consumption of natural resources. In the preparation process, the fine aggregate is first subjected to hydrochloric acid ultrasonic treatment to remove impurities and open the pores. Then, modified powders prepared from fly ash, diatomaceous earth, and basalt are filled into the pores of the fine aggregate through high-pressure impregnation, further enriching and refining the porosity of the aggregate and increasing its toughness and crack resistance. However, this patent does not solve the problems of high water absorption, high crushing index, and poor freeze-thaw deformation resistance of existing concrete aggregates, which seriously affect their practical use.

[0004] Therefore, how to modify the main components of concrete aggregates, introduce functional components, reduce the water absorption rate of concrete aggregates, lower the crushing index, and obtain good freeze-thaw resistance has become a key area that needs to be addressed. Summary of the Invention

[0005] In view of the shortcomings of the prior art, the purpose of this invention is to provide a concrete antifreeze aggregate, antifreeze concrete and preparation method, which aims to solve the problems of high water absorption, high crushing index and poor freeze-thaw deformation resistance of concrete aggregate in the prior art.

[0006] This invention modifies river sand, the main component of concrete aggregate, and introduces functional components such as modified diatomaceous earth, succinic anhydride-polyvinyl alcohol composite material, and epoxide graphene to prepare antifreeze concrete aggregate. This reduces the water absorption rate of the aggregate, lowers the crushing index, and obtains good antifreeze-thaw deformation performance, which can then be applied to antifreeze concrete.

[0007] The technical solution adopted by the present invention to solve the above-mentioned technical problems is as follows:

[0008] In a first aspect, the present invention provides a method for preparing frost-resistant aggregate for concrete, comprising the following steps:

[0009] Step S1: By weight, add 10-20 parts of ferric nitrate to 90-100 parts of deionized water and dissolve them completely. Then add 40-50 parts of river sand and adjust the pH to 9.2-9.6. Stir at 120-160 r / min for 4-6 hours. After stirring, transfer to an oven and heat at 100-104℃ for 10-12 hours to obtain modified river sand.

[0010] Step S2: By weight, add 16-20 parts of diatomaceous earth, 8-12 parts of soluble carbonate, 4-8 parts of polyvinyl alcohol, 2-6 parts of graphene and 1-3 parts of water-reducing agent to 80-100 parts of deionized water and mix evenly to obtain a mixture.

[0011] Step S3: By weight, add 40-50 parts of crushed stone and 30-40 parts of modified river sand to 80-100 parts of the mixture and stir for 2-4 hours to obtain concrete antifreeze aggregate.

[0012] The iron oxide introduced by the modified river sand will be distributed on the surface of the river sand particles, filling or sealing the tiny pores and cracks on the surface. Through the sealing effect of the river sand surface, the chance of water entering the interior of the river sand is effectively reduced, thereby reducing the overall water absorption rate of the aggregate.

[0013] As a preferred technical solution of the present invention, the diatomite is modified diatomite; the preparation method of the modified diatomite includes: adding 20-30 parts by weight of aluminum chloride hexahydrate to 100-120 parts by weight of deionized water and stirring to dissolve, then adding 30-40 parts by weight of diatomite and 4-8 parts by weight of sodium hydroxide to obtain a mixture, vibrating the mixture through a vibrating screen at a speed of 160-200 rpm for 2-4 hours, centrifuging, washing the solid with deionized water, and drying to obtain modified diatomite.

[0014] Modified diatomaceous earth, by introducing aluminum ions, can optimize the pore structure of diatomaceous earth, reduce the number of micropores, thereby weakening the capillary effect of water in aggregates and improving the hydrophobic effect. At the same time, aluminum ion modification can reduce the hydrophilicity of the diatomaceous earth surface, significantly reducing its surface energy, which makes it more difficult for water molecules to spread on the surface, thereby reducing the water absorption rate of concrete aggregates.

[0015] As a preferred embodiment of the present invention, the polyvinyl alcohol is a succinic anhydride-polyvinyl alcohol composite material; the preparation method of the succinic anhydride-polyvinyl alcohol composite material includes: mixing 50-60 parts by weight of n-heptane and 2-4 parts by weight of Span60 uniformly, adding 16-20 parts by weight of 5% polyvinyl alcohol aqueous solution and 4-8 parts by weight of 10% hydrochloric acid solution at 66-68°C, stirring for 60-80 min, adding 4-6 parts by weight of glutaraldehyde, keeping warm at 60-64°C for 2-4 h, washing, and drying to obtain polyvinyl alcohol microspheres; adding 4-6 parts by weight of the polyvinyl alcohol microspheres to 70-80 parts by weight of ethyl acetate and mixing uniformly, then adding 1.2-1.6 parts by weight of succinic anhydride and 0.2-0.4 parts by weight of 4-dimethylaminopyridine, stirring and reacting at 80-90°C for 1-3 h, cooling to room temperature after the reaction is completed, washing, and drying to obtain the succinic anhydride-polyvinyl alcohol composite material.

[0016] The succinic anhydride-polyvinyl alcohol composite material can be modified to improve the dispersibility of polyvinyl alcohol, enabling the composite material to be uniformly dispersed in the matrix of concrete aggregate. At the microscopic level, it acts as a bridge, preventing the propagation of microcracks and absorbing energy, thereby improving the overall mechanical properties and reducing the crushing index of concrete aggregate.

[0017] As a preferred embodiment of the present invention, the graphene is epoxide graphene; the preparation method of the epoxide graphene includes: by weight, adding 14-18 parts of graphene oxide to 90-100 parts of solvent under a nitrogen atmosphere and dispersing them evenly, then adding 1-3 parts of n-butyllithium and ultrasonically activating for 60-90 min, after activation, adding 8-16 parts of epichlorohydrin to carry out a nucleophilic substitution reaction, centrifuging, washing, and obtaining epoxide graphene.

[0018] As a preferred embodiment of the present invention, the solvent is selected from at least one of N,N-dimethylformamide, N,N-dimethylacetamide, and dimethyl sulfoxide.

[0019] As a preferred embodiment of the present invention, the conditions for the nucleophilic substitution reaction include: a temperature of 16–20°C and a time of 6–8 h.

[0020] Epoxy graphene has good thermal conductivity, which can improve the thermal conductivity of concrete aggregates, making temperature changes more evenly distributed throughout the structure rather than concentrated in certain areas. This reduces stress concentration caused by local overheating or cooling, thereby lowering the thermal shrinkage coefficient of the aggregates.

[0021] As a preferred embodiment of the present invention, the soluble carbonate is sodium carbonate and lithium carbonate; the mass ratio of sodium carbonate to lithium carbonate in the soluble carbonate is (1-2):1.

[0022] As a preferred embodiment of the present invention, the water-reducing agent is selected from at least one of polycarboxylate water-reducing agents, melamine water-reducing agents, and naphthalene-based water-reducing agents.

[0023] A second aspect of the present invention provides a concrete antifreeze aggregate prepared by the method described in the first aspect.

[0024] A third aspect of the present invention provides a frost-resistant concrete, comprising frost-resistant aggregates as described in the second aspect;

[0025] The method for preparing the frost-resistant concrete includes:

[0026] (1) Mix 50-60 parts of cement and 30-40 parts of fly ash by weight to obtain a rubber mixture;

[0027] (2) By weight, 80-100 parts of the adhesive mixture, 40-50 parts of the concrete antifreeze aggregate and 20-30 parts of hemp fiber are mixed and stirred evenly to obtain antifreeze concrete.

[0028] Compared with the prior art, the present invention has the following beneficial effects:

[0029] (1) The concrete aggregate of the present invention uses modified river sand as the main material. The iron oxide on the surface of the modified river sand can interact with the carboxyl groups in the succinic anhydride-polyvinyl alcohol composite material to form a stable complex. At the same time, the succinic anhydride-polyvinyl alcohol composite material can react with the epoxy groups of graphene oxide and combine with the modified diatomaceous earth with hydroxyl groups on the surface to form a network interpenetrating structure, reduce the water absorption rate of the concrete aggregate, reduce the crushing index, and obtain good resistance to freeze-thaw deformation.

[0030] (2) The iron oxide introduced by the modified river sand of the present invention will be distributed on the surface of the river sand particles, filling or sealing the tiny pores and cracks on the surface. The sealing effect of the river sand surface effectively reduces the chance of water entering the interior of the river sand, thereby reducing the water absorption rate of the overall aggregate.

[0031] (3) The modified diatomite of the present invention can optimize the pore structure of diatomite by introducing aluminum ions, reduce the number of micropores, thereby weakening the capillary effect of water in aggregate and improving the hydrophobic effect; at the same time, aluminum ion modification can reduce the hydrophilicity of the surface of diatomite, significantly reduce its surface energy, and make it more difficult for water molecules to spread on the surface, thereby reducing the water absorption rate of concrete aggregate.

[0032] (4) The succinic anhydride-polyvinyl alcohol composite material of the present invention can improve the dispersibility of polyvinyl alcohol through modification treatment, so that the composite material can be uniformly dispersed in the matrix of concrete aggregate, play a bridging role at the micro level, prevent the propagation of microcracks, and absorb energy, thereby improving the overall mechanical properties and reducing the crushing index of concrete aggregate.

[0033] (5) The epoxide graphene of the present invention has good thermal conductivity, which can improve the thermal conductivity of concrete aggregate, so that the temperature change is more evenly distributed throughout the structure, rather than concentrated in certain areas, reducing the stress concentration caused by local overheating or cooling, thereby reducing the thermal shrinkage coefficient of the aggregate. Detailed Implementation

[0034] To facilitate understanding of the present invention, the following embodiments are provided. Those skilled in the art should understand that these embodiments are merely illustrative and should not be construed as limiting the scope of the invention.

[0035] The sources of some components in the examples and comparative examples are as follows:

[0036] Crushed stone, item number LC01, purchased from Laizhou Baolailuo Stone Co., Ltd.

[0037] River sand, item number 5768, purchased from Lingshou County Zehong Mineral Products Processing Plant;

[0038] Diatomaceous earth, CAS No. 61790-53-2, was purchased from Shanghai Maclean Biochemical Technology Co., Ltd.

[0039] Sodium carbonate, CAS497-19-8, purchased from Sinopharm Chemical Reagent Co., Ltd.

[0040] Lithium carbonate, CAS554-13-2, purchased from Sinopharm Chemical Reagent Co., Ltd.

[0041] Polyvinyl alcohol, product number P139540, was purchased from Shanghai Aladdin Biochemical Technology Co., Ltd.

[0042] Graphene oxide, model DN-20DY, was purchased from Zhejiang Zhitai Nano-Micro New Materials Co., Ltd.

[0043] Polycarboxylate superplasticizer, model ZWL-A-Ⅸ, purchased from Zhejiang Wulong Chemical Co., Ltd.

[0044] Melamine water-reducing agent, model VF-8, was purchased from Shanghai Lujia Chemical Co., Ltd.

[0045] Naphthalene-based water-reducing agent, model SNF-A, purchased from Shenyang Xingzhenghe Chemical Co., Ltd.

[0046] Ferric nitrate, CAS No. 7782-61-8, purchased from Sinopharm Chemical Reagent Co., Ltd.

[0047] Aluminum chloride hexahydrate, CAS No. 7784-13-6, was purchased from Sinopharm Chemical Reagent Co., Ltd.

[0048] Sodium hydroxide, CAS No. 1310-73-2, was purchased from Sinopharm Chemical Reagent Co., Ltd.

[0049] n-Heptane, CAS No. 142-82-5, was purchased from Shanghai Maclean Biochemical Technology Co., Ltd.

[0050] Span60, part number PA82160, purchased from Shanghai Chuangsai Technology Co., Ltd.

[0051] Hydrochloric acid, CAS No. 7647-01-0, purchased from Sinopharm Chemical Reagent Co., Ltd.

[0052] Glutaraldehyde, CAS No. 111-30-8, purchased from Sinopharm Chemical Reagent Co., Ltd.

[0053] Ethyl acetate, CAS No. 141-78-6, was purchased from Sinopharm Chemical Reagent Co., Ltd.

[0054] Succinic anhydride, CAS No. 108-30-5, was purchased from Shanghai Maclean Biochemical Technology Co., Ltd.

[0055] 4-Dimethylaminopyridine, CAS No. 1122-58-3, was purchased from Shanghai Maclean Biochemical Technology Co., Ltd.

[0056] N,N-Dimethylformamide, CAS No. 68-12-2, was purchased from Sinopharm Chemical Reagent Co., Ltd.

[0057] n-Butyllithium, CAS No. 109-72-8, purchased from Shanghai Maclean Biochemical Technology Co., Ltd.

[0058] Epichlorohydrin, CAS No. 106-89-8, was purchased from Sinopharm Chemical Reagent Co., Ltd.

[0059] Preparation of modified diatomaceous earth: 30 parts by weight of aluminum chloride hexahydrate were added to 120 parts of deionized water and stirred to dissolve. Then, 40 parts of diatomaceous earth and 8 parts of sodium hydroxide were added to obtain a mixture. The mixture was vibrated on a vibrating screen at 200 rpm for 4 hours, centrifuged, the solid was washed with deionized water and dried to obtain modified diatomaceous earth.

[0060] Preparation of succinic anhydride-polyvinyl alcohol composite material: 60 parts by weight of n-heptane and 4 parts by weight of Span60 were mixed evenly. 20 parts by weight of 5% (w / w) polyvinyl alcohol aqueous solution and 8 parts by weight of 10% (w / w) hydrochloric acid solution were added at 68°C. After stirring for 80 min, 6 parts by weight of glutaraldehyde were added. The mixture was kept at 64°C for 2 h, washed, and dried to obtain polyvinyl alcohol microspheres. 6 parts by weight of the polyvinyl alcohol microspheres were added to 80 parts by weight of ethyl acetate and mixed evenly. Then, 1.6 parts by weight of succinic anhydride and 0.4 parts by weight of 4-dimethylaminopyridine were added. The mixture was stirred at 90°C for 1 h. After the reaction was completed, the mixture was cooled to room temperature, washed, and dried to obtain the succinic anhydride-polyvinyl alcohol composite material.

[0061] Preparation of epoxidized graphene: By weight, 18 parts of graphene oxide were added to 100 parts of N,N-dimethylformamide under a nitrogen atmosphere and dispersed evenly. Then, 3 parts of n-butyllithium were added and ultrasonically activated for 90 min. After activation, 16 parts of epichlorohydrin were added to carry out a nucleophilic substitution reaction (temperature 20℃, time 6 h). After centrifugation and washing, epoxidized graphene was obtained.

[0062] Example 1

[0063] This embodiment provides a method for preparing antifreeze aggregate for concrete, including the following steps:

[0064] Step S1: By weight, add 20 parts of ferric nitrate to 100 parts of deionized water and dissolve them completely. Then add 50 parts of river sand and adjust the pH to 9.6. Stir at 160 r / min for 4 hours. After stirring, transfer to an oven and heat at 104℃ for 10 hours to obtain modified river sand.

[0065] Step S2: By weight, add 20 parts modified diatomaceous earth, 12 parts soluble carbonate (8 parts sodium carbonate and 4 parts lithium carbonate), 8 parts succinic anhydride-polyvinyl alcohol composite material, 6 parts epoxidized graphene and 3 parts polycarboxylate superplasticizer to 100 parts deionized water and mix evenly to obtain a mixture.

[0066] Step S3: By weight, add 50 parts crushed stone and 40 parts modified river sand to 100 parts of the mixture and stir for 4 hours to obtain concrete antifreeze aggregate.

[0067] Example 2

[0068] This embodiment provides a method for preparing antifreeze aggregate for concrete, including the following steps:

[0069] Step S1: By weight, add 10 parts of ferric nitrate to 90 parts of deionized water and dissolve them completely. Then add 40 parts of river sand and adjust the pH to 9.2. Stir at 120 r / min for 6 hours. After stirring, transfer to an oven and heat at 100℃ for 12 hours to obtain modified river sand.

[0070] Step S2: By weight, add 16 parts modified diatomaceous earth, 8 parts soluble carbonate (4 parts sodium carbonate and 4 parts lithium carbonate), 4 parts succinic anhydride-polyvinyl alcohol composite material, 2 parts epoxidized graphene and 1 part melamine water-reducing agent to 80 parts deionized water and mix evenly to obtain a mixture.

[0071] Step S3: By weight, add 40 parts crushed stone and 30 parts modified river sand to 80 parts of the mixture and stir for 2 hours to obtain concrete antifreeze aggregate.

[0072] Example 3

[0073] This embodiment provides a method for preparing antifreeze aggregate for concrete, including the following steps:

[0074] Step S1: By weight, 15 parts of ferric nitrate were added to 95 parts of deionized water and dissolved completely. Then, 45 parts of river sand were added and the pH was adjusted to 9.4. The mixture was stirred at 140 r / min for 5 h. After stirring, it was transferred to an oven and heated at 102 ℃ for 11 h to obtain modified river sand.

[0075] Step S2: By weight, add 18 parts modified diatomaceous earth, 10 parts soluble carbonate (6 parts sodium carbonate and 4 parts lithium carbonate), 6 parts succinic anhydride-polyvinyl alcohol composite material, 4 parts epoxidized graphene and 2 parts naphthalene-based water reducing agent to 90 parts deionized water and mix evenly to obtain a mixture.

[0076] Step S3: By weight, add 45 parts crushed stone and 35 parts modified river sand to 90 parts of the mixture and stir for 3 hours to obtain concrete antifreeze aggregate.

[0077] Comparative Example 1

[0078] This comparative example provides a method for preparing concrete antifreeze aggregate, which differs from Example 1 in that commercially available river sand is used instead of modified river sand.

[0079] Comparative Example 2

[0080] This comparative example provides a method for preparing concrete antifreeze aggregate, which differs from Example 1 in that commercially available diatomaceous earth is used instead of modified diatomaceous earth.

[0081] Comparative Example 3

[0082] This comparative example provides a method for preparing concrete antifreeze aggregate. The difference from Example 1 is that the amount of sodium carbonate in the soluble carbonate is changed to 4 parts and the amount of lithium carbonate is changed to 8 parts.

[0083] Comparative Example 4

[0084] This comparative example provides a method for preparing concrete antifreeze aggregate. The difference from Example 1 is that the amount of sodium carbonate in the soluble carbonate is changed to 10 parts and the amount of lithium carbonate is changed to 2 parts.

[0085] Comparative Example 5

[0086] This comparative example provides a method for preparing concrete antifreeze aggregate, which differs from Example 1 in that commercially available polyvinyl alcohol is used instead of succinic anhydride-polyvinyl alcohol composite material.

[0087] Comparative Example 6

[0088] This comparative example provides a method for preparing concrete antifreeze aggregate, which differs from Example 1 in that commercially available graphene oxide is used instead of epoxide graphene.

[0089] The performance of the concrete antifreeze aggregates provided in the above embodiments and comparative examples was tested, and the specific test methods are as follows:

[0090] (1) Water absorption test: The test shall be conducted in accordance with the requirements of GB / T 14685-2022 Construction Pebbles and Crushed Stones.

[0091] (2) Crushing index test: The test shall be conducted in accordance with the requirements of GB / T 14685-2022 Construction gravel and crushed stone.

[0092] (3) Freeze-thaw deformation resistance test: The test shall be conducted in accordance with the requirements of the "Test Procedure for Inorganic Binder Stabilized Materials for Highway Engineering" (JTG3441-2024).

[0093] The performance test data above are shown in Table 1.

[0094] Table 1 Performance Test Results

[0095]

[0096]

[0097] As can be seen from the above, this invention modifies river sand, the main component of concrete aggregate, and introduces functional components such as modified diatomaceous earth, succinic anhydride-polyvinyl alcohol composite material, and epoxide graphene to prepare concrete antifreeze aggregate (Examples 1-3). Its water absorption rate is 2.21-2.28%, its crushing index is 14.78-14.86%, and its thermal shrinkage coefficient (10...-6 The value (°C) ranged from 9.5 to 10.2.

[0098] Compared to Example 1, using commercially available river sand instead of modified river sand resulted in increased water absorption, increased crushing index, and increased coefficient of thermal shrinkage of the aggregate (Comparative Example 1); compared to Example 1, using commercially available diatomaceous earth instead of modified diatomaceous earth resulted in increased water absorption, increased crushing index, and increased coefficient of thermal shrinkage of the aggregate (Comparative Example 2); compared to Example 1, the amount of sodium carbonate in the soluble carbonate was changed to 4 parts and the amount of lithium carbonate was changed to 8 parts. Due to insufficient sodium carbonate, the compounding effect was poor, resulting in increased water absorption, increased crushing index, and increased coefficient of thermal shrinkage of the aggregate (Comparative Example 3); compared to Example 1... In Comparative Example 4, the amount of sodium carbonate in the soluble carbonate was changed to 10 parts and the amount of lithium carbonate was changed to 2 parts. Due to the insufficient amount of sodium carbonate, the compounding effect was not good, resulting in an increase in the water absorption rate of the aggregate, an increase in the crushing index, and an increase in the coefficient of thermal shrinkage (Comparative Example 5). In Comparative Example 6, the water absorption rate of the aggregate increased, the crushing index increased, and the coefficient of thermal shrinkage increased when commercially available polyvinyl alcohol was used instead of succinic anhydride-polyvinyl alcohol composite material (Comparative Example 1). In Comparative Example 7, the water absorption rate of the aggregate increased, the crushing index increased, and the coefficient of thermal shrinkage increased when commercially available graphene oxide was used instead of epoxide graphene (Comparative Example 6).

[0099] In summary, this invention modifies river sand, the main component of concrete aggregate, and introduces functional components such as modified diatomaceous earth, succinic anhydride-polyvinyl alcohol composite material, and epoxide graphene to prepare antifreeze aggregate for concrete. This reduces the water absorption rate of the aggregate, lowers the crushing index, and obtains good freeze-thaw deformation resistance, which can then be applied to antifreeze concrete.

Claims

1. A method for preparing frost-resistant aggregate for concrete, Its features are, Includes the following steps: Step S1: By weight, add 10-20 parts of ferric nitrate to 90-100 parts of deionized water and dissolve them completely. Then add 40-50 parts of river sand and adjust the pH to 9.2-9.

6. Stir at 120-160 r / min for 4-6 hours. After stirring, transfer to an oven and heat at 100-104℃ for 10-12 hours to obtain modified river sand. Step S2: By weight, add 16-20 parts of modified diatomaceous earth, 8-12 parts of soluble carbonate, 4-8 parts of succinic anhydride-polyvinyl alcohol composite material, 2-6 parts of epoxidized graphene and 1-3 parts of water-reducing agent to 80-100 parts of deionized water and mix evenly to obtain a mixture. Step S3: By weight, add 40-50 parts of crushed stone and 30-40 parts of modified river sand to 80-100 parts of the mixture, and stir for 2-4 hours to obtain concrete antifreeze aggregate; The method for preparing the modified diatomaceous earth includes: adding 20-30 parts by weight of aluminum chloride hexahydrate to 100-120 parts by weight of deionized water and stirring to dissolve; then adding 30-40 parts by weight of diatomaceous earth and 4-8 parts by weight of sodium hydroxide to obtain a mixture; vibrating the mixture through a vibrating screen at a speed of 160-200 rpm for 2-4 hours; centrifuging; washing the solid with deionized water; and drying to obtain the modified diatomaceous earth. The preparation method of the succinic anhydride-polyvinyl alcohol composite material includes: mixing 50-60 parts by weight of n-heptane and 2-4 parts by weight of Span60 evenly, adding 16-20 parts by weight of 5% polyvinyl alcohol aqueous solution and 4-8 parts by weight of 10% hydrochloric acid solution at 66-68℃, stirring for 60-80 min, adding 4-6 parts by weight of glutaraldehyde, keeping warm at 60-64℃ for 2-4 h, washing, and drying to obtain polyvinyl alcohol microspheres; adding 4-6 parts by weight of the polyvinyl alcohol microspheres to 70-80 parts by weight of ethyl acetate and mixing evenly, then adding 1.2-1.6 parts by weight of succinic anhydride and 0.2-0.4 parts by weight of 4-dimethylaminopyridine, stirring and reacting at 80-90℃ for 1-3 h, cooling to room temperature after the reaction is completed, washing, and drying to obtain the succinic anhydride-polyvinyl alcohol composite material; The method for preparing the epoxidized graphene includes: adding 14-18 parts by weight of graphene oxide to 90-100 parts by weight of solvent under a nitrogen atmosphere and dispersing them evenly; then adding 1-3 parts by weight of n-butyllithium and ultrasonically activating for 60-90 min; after activation, adding 8-16 parts by weight of epichlorohydrin to carry out a nucleophilic substitution reaction; centrifuging and washing to obtain epoxidized graphene.

2. The method for preparing concrete antifreeze aggregate according to claim 1, characterized in that, The solvent is selected from at least one of N,N-dimethylformamide, N,N-dimethylacetamide, and dimethyl sulfoxide.

3. The method for preparing concrete antifreeze aggregate according to claim 1, characterized in that, The conditions for the nucleophilic substitution reaction include a temperature of 16–20 °C and a time of 6–8 h.

4. The method for preparing concrete antifreeze aggregate according to claim 1, characterized in that, The soluble carbonate is sodium carbonate and lithium carbonate; the mass ratio of sodium carbonate to lithium carbonate in the soluble carbonate is (1-2):

1.

5. The method for preparing concrete antifreeze aggregate according to claim 1, characterized in that, The water-reducing agent is selected from at least one of polycarboxylate water-reducing agents, melamine water-reducing agents, and naphthalene-based water-reducing agents.

6. A concrete antifreeze aggregate, characterized in that... ， Prepared by the method according to any one of claims 1-5.

7. A type of frost-resistant concrete, characterized in that, Includes the concrete antifreeze aggregate as described in claim 6; The method for preparing the frost-resistant concrete includes: (1) Mix 50-60 parts of cement and 30-40 parts of fly ash by weight to obtain a rubber mixture; (2) By weight, 80-100 parts of the adhesive mixture, 40-50 parts of the concrete antifreeze aggregate and 20-30 parts of hemp fiber are mixed and stirred evenly to obtain antifreeze concrete.

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