Concrete anti-freezing aggregate, anti-freezing concrete and preparation method

Abstract

The invention belongs to the technical field of building materials, and particularly relates to concrete anti-freezing aggregate, anti-freezing concrete and a preparation method. The main component river sand of the concrete aggregate is modified, and functional components such as the modified diatomite, the succinic anhydride-polyvinyl alcohol composite material and the epoxidized graphene are introduced, so that the concrete anti-freezing aggregate is prepared, the water absorption rate of the aggregate is reduced, the crushing index is reduced, and meanwhile, good anti-freezing and anti-thawing deformation performance is obtained; the anti-freezing agent is applied to anti-freezing concrete.

Description

Technical Field

[0001] The invention belongs to the technical field of building materials, and in particular relates to a concrete antifreeze aggregate, antifreeze concrete and a preparation method. Background Art

[0002] Sand and gravel aggregates are the largest component in concrete, and they are also the most stable component in concrete. In order to achieve high durability in concrete, it is necessary to increase the proportion of aggregates as much as possible and control and reduce the proportion of slurry while meeting the construction performance. The quality of aggregates directly affects the workability of fresh concrete, the volume stability of concrete, and ultimately the durability of concrete. Aggregates are the upstream link of concrete quality control. If the quality of sand and gravel is poor, the porosity is high, and the particle shape is not good, it will not only affect the workability of the concrete mixture, but also have an adverse effect on the mechanical properties and durability of concrete.

[0003] A Chinese patent (publication number CN116947350A) discloses a method for reinforcing recycled concrete aggregates. The invention prepares concrete aggregates after pre-treatment of 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 in the fine aggregate and open the pores in the fine aggregate. Then, the modified powder prepared from fly ash, diatomaceous earth, and basalt is filled into the pores of the fine aggregate by high-pressure impregnation treatment, further enriching and refining the pores in the aggregate, and increasing the toughness and crack resistance of the aggregate. However, the patent does not solve the problems of large water absorption, high crushing index, and poor freeze-thaw deformation resistance of concrete aggregates in the prior art, which seriously affects its actual use.

[0004] Therefore, how to modify the main components of concrete aggregate and introduce functional components to reduce the water absorption of concrete aggregate, lower the crushing index, and obtain good anti-freeze-thaw deformation performance has become a direction that needs to be focused on. Summary of the invention

[0005] In view of the deficiencies in the prior art, the purpose of the present invention is to provide a concrete frost-resistant aggregate, frost-resistant concrete and a preparation method, aiming to solve the problems of concrete aggregate in the prior art, such as high water absorption, high crushing index and poor anti-freeze-thaw deformation performance.

[0006] The present invention prepares frost-resistant concrete aggregate by modifying river sand, the main component of concrete aggregate, and introducing functional components such as modified diatomaceous earth, succinic anhydride-polyvinyl alcohol composite material and epoxidized graphene, thereby reducing the water absorption rate of the aggregate and the crushing index, while obtaining good anti-freeze-thaw deformation performance, and applying the concrete aggregate to frost-resistant concrete.

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

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

[0009] Step S1: adding 10 to 20 parts of ferric nitrate to 90 to 100 parts of deionized water by weight to fully dissolve, then adding 40 to 50 parts of river sand and adjusting the pH to 9.2 to 9.6, stirring at a speed of 120 to 160 r / min for 4 to 6 hours, transferring to an oven after stirring, and heating at 100 to 104° C. for 10 to 12 hours to obtain modified river sand;

[0010] Step S2: adding 16 to 20 parts of diatomaceous earth, 8 to 12 parts of soluble carbonate, 4 to 8 parts of polyvinyl alcohol, 2 to 6 parts of graphene and 1 to 3 parts of water reducing agent to 80 to 100 parts of deionized water, and mixing them uniformly to obtain a mixture;

[0011] Step S3: In parts by weight, 40 to 50 parts of crushed stone and 30 to 40 parts of modified river sand are added to 80 to 100 parts of the mixture, and stirred for 2 to 4 hours to obtain frost-resistant concrete aggregate.

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

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

[0014] Modified diatomite can optimize the pore structure of diatomite and reduce the number of tiny pores by introducing aluminum ions, thereby weakening the capillary effect of water in the aggregate and improving the hydrophobic effect; at the same time, aluminum ion modification can reduce the hydrophilicity of the diatomite surface, 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.

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

[0016] The dispersibility of polyvinyl alcohol in succinic anhydride-polyvinyl alcohol composite materials can be improved through modification treatment, so that the composite materials can be evenly dispersed in the matrix of concrete aggregate, playing a bridging role at the micro level, preventing the expansion of microcracks and absorbing energy, thereby improving the overall mechanical properties and reducing the crushing index of concrete aggregate.

[0017] As a preferred technical solution of the present invention, the graphene is epoxidized graphene; the preparation method of the epoxidized graphene comprises: in parts by weight, in a nitrogen atmosphere, adding 14 to 18 parts of graphene oxide to 90 to 100 parts of a solvent and dispersing them uniformly, then adding 1 to 3 parts of n-butyl lithium for ultrasonic activation for 60 to 90 minutes, adding 8 to 16 parts of epichlorohydrin after the activation is completed to carry out a nucleophilic substitution reaction, centrifuging, washing, and obtaining epoxidized graphene.

[0018] As a preferred technical solution 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 technical solution of the present invention, the conditions of the nucleophilic substitution reaction include: temperature of 16 to 20° C. and time of 6 to 8 hours.

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

[0021] As a preferred technical solution 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 technical solution of the present invention, the water reducer is selected from at least one of polycarboxylic acid water reducer, melamine water reducer and naphthalene water reducer.

[0023] The second aspect of the present invention provides a frost-resistant concrete aggregate prepared by the method described in the first aspect.

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

[0025] The preparation method of the frost-resistant concrete comprises:

[0026] (1) By weight, 50 to 60 parts of cement and 30 to 40 parts of fly ash are mixed to obtain a rubber mixture;

[0027] (2) By weight, 80 to 100 parts of the adhesive mixture, 40 to 50 parts of the concrete antifreeze aggregate and 20 to 30 parts of hemp fiber are mixed and stirred uniformly 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 group 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 group of the epoxide graphene and combine with the modified diatomaceous earth with hydroxyl groups on the surface, thereby forming a network interpenetrating structure, reducing the water absorption rate of the concrete aggregate, reducing the crushing index, and obtaining good anti-freeze-thaw deformation ability.

[0030] (2) The iron oxide introduced into 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 moisture 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 and reduce the number of tiny pores by introducing aluminum ions, thereby weakening the capillary action of water in the aggregate and improving the hydrophobic effect; at the same time, aluminum ion modification can reduce the hydrophilicity of the diatomite surface, significantly reducing its surface energy, resulting in an increase in the difficulty of water molecules spreading on the surface, thereby reducing the water absorption rate of the 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 evenly dispersed in the matrix of concrete aggregate, play a bridging role at the micro level, prevent the expansion of micro cracks, and absorb energy, thereby improving the overall mechanical properties and reducing the crushing index of concrete aggregate.

[0033] (5) The epoxidized graphene of the present invention has good thermal conductivity, which can improve the thermal conductivity efficiency of concrete aggregates, making the temperature changes more evenly distributed throughout the structure rather than concentrated in certain areas, thereby reducing stress concentration caused by local overheating or cooling, thereby reducing the thermal shrinkage coefficient of the aggregates. DETAILED DESCRIPTION

[0034] For the convenience of understanding the present invention, the present invention lists the following embodiments. It should be understood by those skilled in the art that the embodiments are only to help understand the present invention and should not be regarded as specific limitations of the present invention.

[0035] The sources of some components in the embodiments 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, was 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, CAS 497-19-8, was purchased from Sinopharm Chemical Reagent Co., Ltd.;

[0040] Lithium carbonate, CAS554-13-2, was 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 Zhiti Nano Micro New Materials Co., Ltd.;

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

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

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

[0046] Ferric nitrate, CAS No. 7782-61-8, was 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, catalog number PA82160, purchased from Shanghai Chuangsai Technology Co., Ltd.;

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

[0052] Glutaraldehyde, CAS No. 111-30-8, was 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, purchased from Shanghai MacLean Biochemical Technology Co., Ltd.;

[0056] N,N-dimethylformamide, CAS number 68-12-2, purchased from Sinopharm Chemical Reagent Co., Ltd.;

[0057] n-Butyl lithium, 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: In parts by weight, 30 parts of aluminum chloride hexahydrate are added to 120 parts of deionized water and stirred to dissolve, and then 40 parts of diatomaceous earth and 8 parts of sodium hydroxide are added to obtain a mixture, and the mixture is vibrated at a rotation speed of 200 rpm for 4 hours through a vibrating screen, centrifuged, and the solid is washed with deionized water and dried to obtain modified diatomaceous earth.

[0060] Preparation of succinic anhydride-polyvinyl alcohol composite material: in parts by weight, 60 parts of n-heptane and 4 parts of Span60 are mixed evenly, 20 parts of 5% polyvinyl alcohol aqueous solution and 8 parts of 10% hydrochloric acid solution are added at 68°C, stirred for 80 minutes, 6 parts of glutaraldehyde are added, and the mixture is kept warm at 64°C for 2 hours, washed, and dried to obtain polyvinyl alcohol microspheres; 6 parts of the polyvinyl alcohol microspheres are added to 80 parts of ethyl acetate and mixed evenly, and then 1.6 parts of succinic anhydride and 0.4 parts of 4-dimethylaminopyridine are added, and the reaction is stirred at 90°C for 1 hour. After the reaction is completed, it is cooled to room temperature, washed, and dried to obtain a succinic anhydride-polyvinyl alcohol composite material.

[0061] Preparation of epoxidized graphene: In parts by weight, under a nitrogen atmosphere, 18 parts of graphene oxide are added to 100 parts of N,N-dimethylformamide and dispersed evenly, and then 3 parts of n-butyl lithium are added for ultrasonic activation for 90 minutes. After the activation is completed, 16 parts of epichlorohydrin are added for nucleophilic substitution reaction (temperature is 20°C, time is 6 hours), centrifuged, washed, and epoxidized graphene is obtained.

[0062] Example 1

[0063] This embodiment provides a method for preparing frost-resistant concrete aggregate, comprising the following steps:

[0064] Step S1: by weight, 20 parts of ferric nitrate are added to 100 parts of deionized water to fully dissolve, and then 50 parts of river sand are added and the pH is adjusted to 9.6, and the mixture is stirred at a speed of 160 r / min for 4 hours. After the stirring is completed, the mixture is transferred to an oven and heated at 104° C. for 10 hours to obtain modified river sand;

[0065] Step S2: adding 20 parts of modified diatomaceous earth, 12 parts of soluble carbonate (8 parts of sodium carbonate and 4 parts of lithium carbonate), 8 parts of succinic anhydride-polyvinyl alcohol composite material, 6 parts of epoxidized graphene and 3 parts of polycarboxylic acid water reducer to 100 parts of deionized water, mixing evenly to obtain a mixture;

[0066] Step S3: In parts by weight, 50 parts of crushed stone and 40 parts of modified river sand are added to 100 parts of the mixture, and stirred for 4 hours to obtain concrete antifreeze aggregate.

[0067] Example 2

[0068] This embodiment provides a method for preparing frost-resistant concrete aggregate, comprising the following steps:

[0069] Step S1: In parts by weight, 10 parts of ferric nitrate are added to 90 parts of deionized water to fully dissolve, and then 40 parts of river sand are added and the pH is adjusted to 9.2, and the mixture is stirred at a speed of 120 r / min for 6 hours. After the stirring is completed, the mixture is transferred to an oven and heated at 100° C. for 12 hours to obtain modified river sand;

[0070] Step S2: adding 16 parts of modified diatomaceous earth, 8 parts of soluble carbonate (4 parts of sodium carbonate and 4 parts of lithium carbonate), 4 parts of succinic anhydride-polyvinyl alcohol composite material, 2 parts of epoxy graphene and 1 part of melamine water reducer to 80 parts of deionized water, mixing evenly to obtain a mixture;

[0071] Step S3: In parts by weight, 40 parts of crushed stone and 30 parts of modified river sand are added to 80 parts of the mixture, and stirred for 2 hours to obtain concrete antifreeze aggregate.

[0072] Example 3

[0073] This embodiment provides a method for preparing frost-resistant concrete aggregate, comprising the following steps:

[0074] Step S1: by weight, 15 parts of ferric nitrate are added to 95 parts of deionized water to fully dissolve, and then 45 parts of river sand are added and the pH is adjusted to 9.4, and the mixture is stirred at a speed of 140 r / min for 5 hours. After the stirring is completed, the mixture is transferred to an oven and heated at 102° C. for 11 hours to obtain modified river sand;

[0075] Step S2: adding 18 parts of modified diatomaceous earth, 10 parts of soluble carbonate (6 parts of sodium carbonate and 4 parts of lithium carbonate), 6 parts of succinic anhydride-polyvinyl alcohol composite material, 4 parts of epoxidized graphene and 2 parts of naphthalene-based water reducer to 90 parts of deionized water, mixing evenly to obtain a mixture;

[0076] Step S3: In parts by weight, 45 parts of crushed stone and 35 parts of modified river sand are added to 90 parts of the mixture, and stirred for 3 hours to obtain concrete antifreeze aggregate.

[0077] Comparative Example 1

[0078] This comparative example provides a method for preparing frost-resistant concrete 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 a concrete antifreeze aggregate, which is different 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 antifreeze aggregate for concrete, which is different from Example 1 in 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 antifreeze aggregate for concrete, which is different from Example 1 in 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 a frost-resistant concrete aggregate, which differs from Example 1 in that commercially available polyvinyl alcohol is used instead of the succinic anhydride-polyvinyl alcohol composite material.

[0087] Comparative Example 6

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

[0089] The performance of the concrete antifreeze aggregate provided in the above embodiments and comparative examples was tested, and the specific testing method is as follows:

[0090] (1) Water absorption test: refer to the requirements of GB / T 14685-2022 Pebbles and crushed stones for construction for testing.

[0091] (2) Crushing index test: refer to the requirements of GB / T 14685-2022 Pebbles and crushed stones for construction for testing.

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

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

[0094] Table 1 Performance test results

[0095]

[0096]

[0097] From the above content, it can be seen that the present invention prepares concrete antifreeze aggregate (Examples 1 to 3) by modifying the main component of concrete aggregate, river sand, and introducing functional components such as modified diatomaceous earth, succinic anhydride-polyvinyl alcohol composite material and epoxy graphene, and the water absorption rate is 2.21-2.28%, the crushing index is 14.78-14.86%, and the temperature shrinkage coefficient (10-6 / ℃) is 9.5~10.2.

[0098] Compared with Example 1, commercially available river sand was used instead of modified river sand, and the water absorption rate of the aggregate increased, the crushing index increased, and the thermal shrinkage coefficient increased (Comparative Example 1); Compared with Example 1, commercially available diatomaceous earth was used instead of modified diatomaceous earth, and the water absorption rate of the aggregate increased, the crushing index increased, and the thermal shrinkage coefficient increased (Comparative Example 2); Compared with 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 the small amount of sodium carbonate, the compounding effect was not good, the water absorption rate of the aggregate increased, the crushing index increased, and the thermal shrinkage coefficient increased (Comparative Example 3); Compared with Example 1 , 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 small amount of sodium carbonate, the compounding effect was not good, the water absorption rate of the aggregate increased, the crushing index increased, and the thermal shrinkage coefficient increased (Comparative Example 4); compared with Example 1, commercially available polyvinyl alcohol was used to replace the succinic anhydride-polyvinyl alcohol composite material, the water absorption rate of the aggregate increased, the crushing index increased, and the thermal shrinkage coefficient increased (Comparative Example 5); compared with Example 1, commercially available graphene oxide was used to replace epoxidized graphene, the water absorption rate of the aggregate increased, the crushing index increased, and the thermal shrinkage coefficient increased (Comparative Example 6).

[0099] In summary, the present invention prepares frost-resistant concrete aggregate by modifying river sand, the main component of concrete aggregate, and introducing functional components such as modified diatomaceous earth, succinic anhydride-polyvinyl alcohol composite material and epoxidized graphene, thereby reducing the water absorption rate of the aggregate and the crushing index, while obtaining good anti-freeze-thaw deformation performance, and applying it to frost-resistant concrete.

Claims

1. A method for preparing frost-resistant concrete aggregate, characterized in that: The following steps are involved: Step S1: adding 10 to 20 parts of ferric nitrate to 90 to 100 parts of deionized water by weight to fully dissolve, then adding 40 to 50 parts of river sand and adjusting the pH to 9.2 to 9.6, stirring at a speed of 120 to 160 r / min for 4 to 6 hours, transferring to an oven after stirring, and heating at 100 to 104° C. for 10 to 12 hours to obtain modified river sand; Step S2: adding 16 to 20 parts of diatomaceous earth, 8 to 12 parts of soluble carbonate, 4 to 8 parts of polyvinyl alcohol, 2 to 6 parts of graphene and 1 to 3 parts of water reducing agent to 80 to 100 parts of deionized water, and mixing them uniformly to obtain a mixture; Step S3: In parts by weight, 40 to 50 parts of crushed stone and 30 to 40 parts of modified river sand are added to 80 to 100 parts of the mixture, and stirred for 2 to 4 hours to obtain frost-resistant concrete aggregate.

2. The method for preparing a frost-resistant concrete aggregate according to claim 1, characterized in that: The diatomaceous earth is modified diatomaceous earth; The preparation method of the modified diatomite comprises: adding 20 to 30 parts of aluminum chloride hexahydrate to 100 to 120 parts of deionized water by weight, stirring and dissolving, then adding 30 to 40 parts of diatomite and 4 to 8 parts of sodium hydroxide to obtain a mixture, vibrating the mixture for 2 to 4 hours at a rotation speed of 160 to 200 rpm through a vibrating screen, centrifuging, washing the solid with deionized water, and drying to obtain the modified diatomite.

3. The method for preparing a frost-resistant concrete aggregate according to claim 1, characterized in that: The polyvinyl alcohol is a succinic anhydride-polyvinyl alcohol composite material; The preparation method of the succinic anhydride-polyvinyl alcohol composite material comprises: mixing 50-60 parts of n-heptane and 2-4 parts of Span60 by weight, adding 16-20 parts of polyvinyl alcohol aqueous solution with a mass concentration of 5% and 4-8 parts of hydrochloric acid solution with a mass concentration of 10% at 66-68° C., stirring for 60-80 minutes, adding 4-6 parts of glutaraldehyde, keeping warm at 60-64° C. for 2-4 hours, washing, drying, and obtaining polyvinyl alcohol microspheres; adding 4-6 parts of the polyvinyl alcohol microspheres to 70-80 parts of ethyl acetate and mixing evenly, then adding 1.2-1.6 parts of succinic anhydride and 0.2-0.4 parts of 4-dimethylaminopyridine, stirring and reacting at 80-90° C. for 1-3 hours, cooling to room temperature after the reaction is completed, washing, drying, and obtaining the succinic anhydride-polyvinyl alcohol composite material.

4. The method for preparing a frost-resistant concrete aggregate according to claim 1, characterized in that: The graphene is epoxidized graphene; The preparation method of the epoxidized graphene comprises: adding 14 to 18 parts of graphene oxide to 90 to 100 parts of solvent in a nitrogen atmosphere and dispersing the mixture uniformly, then adding 1 to 3 parts of n-butyl lithium for ultrasonic activation for 60 to 90 minutes, adding 8 to 16 parts of epichlorohydrin for nucleophilic substitution reaction after activation, centrifuging, washing, and obtaining the epoxidized graphene.

5. The method for preparing a frost-resistant concrete aggregate according to claim 4, characterized in that: The solvent is selected from at least one of N,N-dimethylformamide, N,N-dimethylacetamide and dimethyl sulfoxide.

6. The method for preparing a frost-resistant concrete aggregate according to claim 4, characterized in that: The conditions of the nucleophilic substitution reaction include: temperature of 16-20° C. and time of 6-8 h.

7. The method for preparing a frost-resistant concrete aggregate according to claim 1, characterized in that: The soluble carbonates are sodium carbonate and lithium carbonate; the mass ratio of sodium carbonate to lithium carbonate in the soluble carbonate is (1-2):

1.

8. The method for preparing frost-resistant concrete aggregate according to claim 1, characterized in that: The water reducer is selected from at least one of polycarboxylic acid water reducer, melamine water reducer and naphthalene water reducer.

9. A concrete antifreeze aggregate, characterized in that: Prepared according to the method according to any one of claims 1 to 8.

10. A frost-resistant concrete, characterized in that: The concrete antifreeze aggregate as claimed in claim 9; The preparation method of the frost-resistant concrete comprises: (1) By weight, 50 to 60 parts of cement and 30 to 40 parts of fly ash are mixed to obtain a rubber mixture; (2) By weight, 80 to 100 parts of the adhesive mixture, 40 to 50 parts of the concrete antifreeze aggregate and 20 to 30 parts of hemp fiber are mixed and stirred uniformly to obtain antifreeze concrete.

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