High corrosion resistant artificial aggregates and their preparation of corrosion resistant and crack-resistant cement concrete and their application in bridge components

Abstract

This invention discloses a high-corrosion-resistant artificial aggregate, its preparation method, and corrosion-resistant and crack-resistant cement concrete. The high-corrosion-resistant artificial aggregate comprises: dredged soil, calcium oxide, magnesium oxide, magnesium chloride, waterproofing agent, rice husk ash, polyacrylamide, montmorillonite, sodium aluminate, and water. The corrosion-resistant and crack-resistant cement concrete comprises: the high-corrosion-resistant artificial aggregate, cement, natural sand, natural coarse aggregate, and impermeable and crack-resistant microcapsules, suitable for bridge components. The high-corrosion-resistant artificial aggregate provided by this invention is a porous material, which improves the resistance of bridge components to chloride ion erosion while reducing the self-weight of the components. The impermeable and crack-resistant microcapsules have crack recognition capabilities, which can accurately seal cracks in bridge components and adsorb chloride ions. The high-corrosion-resistant artificial aggregate and corrosion-resistant and crack-resistant cement concrete of this invention can reduce the diffusion of external chloride ions into concrete through both chemical reaction and physical adsorption, greatly preventing or delaying the corrosion of bridge structures by chloride ions.

Description

Technical Field

[0001] This invention belongs to the field of building materials technology, and relates to chloride ion resistant materials, specifically to a highly corrosion-resistant artificial aggregate and its preparation method, and corrosion-resistant and crack-resistant cement concrete suitable for bridge components. Background Technology

[0002] Cement-based materials, due to their low tensile strength and early shrinkage deformation, are easily affected by temperature gradients, humidity changes, plastic shrinkage, and settlement shrinkage, resulting in surface cracks and deep internal microcracks. Cement concrete bridges, due to limitations in structural design, material selection, and construction techniques, as well as the complex service environment, suffer damage such as cracking caused by harmful ion corrosion during use, affecting vehicle safety and reducing the bridge's service life. Therefore, improving the corrosion and crack resistance of bridge components is particularly urgent.

[0003] Chloride ions are widely present in salt lakes, saline-alkali lands, and seawater. They enter road structures through diffusion and infiltration, causing adverse effects such as crystallization and salt swelling. Currently, measures to improve the chloride ion resistance of concrete structures mainly include improving concrete quality and applying anti-corrosion coatings to the surface of concrete components. However, improving the chloride ion erosion resistance of road structures solely through these two methods is insufficient. They cannot fundamentally hinder or delay the transport and erosion of chloride ions, and anti-corrosion measures for bridge components cannot cover all parts. For some components, it is impossible to prevent localized erosion by chloride ions from the natural environment.

[0004] Based on existing technology, it is necessary to develop a type of cement concrete that is resistant to chloride ion corrosion and cracking, and can resist the erosion of harmful ions in the natural environment. Summary of the Invention

[0005] To address the shortcomings of existing technologies, the present invention aims to provide a highly corrosion-resistant artificial aggregate, its preparation method, and corrosion-resistant and crack-resistant cement concrete suitable for bridge components, which can effectively improve the bridge structure's resistance to harmful ion erosion.

[0006] Dredged soil is soil produced during underwater earthwork excavation projects, whether manually or mechanically, when dredging, widening, or deepening rivers, lakes, or other bodies of water. It is characterized by fine particles and low bearing capacity. The most common disposal method is landfilling, but this cannot remove the pollutants and causes secondary pollution. Another common recycling method involves solidifying the dredged soil to improve its strength, pore structure, and compaction, transforming it into usable civil engineering building materials. However, solidified dredged soil is generally used as a raw material for soil and rock; there are no reports of it being used as artificial aggregate or possessing corrosion-resistant properties.

[0007] To solve the above-mentioned technical problems, the embodiments of this application adopt the following technical solutions:

[0008] In a first aspect, embodiments of this application provide a highly corrosion-resistant artificial aggregate, wherein the highly corrosion-resistant artificial aggregate has a core-shell structure, comprising a core material and an outer shell material surrounding the core material;

[0009] The core material is made of the following materials in parts by weight: 35-55 parts dredged soil, 2-7 parts calcium oxide, 5-11 parts magnesium oxide, 0.17-0.35 parts magnesium chloride, and 0.1-0.5 parts water-resistant agent;

[0010] The outer shell material is made of the following materials in parts by weight: 10-15 parts rice husk ash, 5-10 parts polyacrylamide, 2-5 parts montmorillonite, 1-2 parts sodium aluminate, and 12-14 parts water.

[0011] The ratio of the amount of core material to the amount of outer shell material is 6-12:2-6.

[0012] Furthermore, the water-resistant agent may be one or more of sodium phosphate, ferrous sulfate, magnesium sulfate, or alum.

[0013] Preferably, the core material is made of the following materials in parts by weight: 35-45 parts dredged soil, 5-7 parts calcium oxide, 5-11 parts magnesium oxide, 0.17-0.35 parts magnesium chloride, and 0.1-0.5 parts water-resistant agent;

[0014] Preferably, the outer shell material is made of the following materials in parts by weight: 10-15 parts rice husk ash, 8-10 parts polyacrylamide, 2-5 parts montmorillonite, 1-2 parts sodium aluminate, and 12-14 parts water.

[0015] The preferred ratio of the core material to the outer shell material is 9-12:4-6.

[0016] Furthermore, the core material is prepared by the following method: 35-55 parts of dredged soil, 2-7 parts of calcium oxide, 5-11 parts of magnesium oxide, 0.17-0.35 parts of magnesium chloride, and 0.1-0.5 parts of water-resistant agent are mixed and granulated to obtain the core material. Specifically, a pelletizing machine is generally used for granulation.

[0017] The outer shell material is prepared by mixing all the outer shell raw materials into a slurry, adding 2 to 6 parts of the slurry to 6 to 12 parts of the core material for coating, and then screening after natural curing for 7 days to obtain the high corrosion resistant artificial aggregate. Specifically, the coating is generally carried out in a pelletizing machine.

[0018] Natural maintenance conditions are generally 85±5% relative humidity and 23±2℃ temperature.

[0019] Further, particles with a diameter of 4.75 mm to 15 mm are screened out to obtain the high corrosion-resistant artificial aggregate.

[0020] Secondly, this application embodiment also provides a method for preparing the high corrosion-resistant artificial aggregate, the method comprising the following steps;

[0021] (1) Weigh out 35-55 parts of dredged soil, 2-7 parts of calcium oxide, 5-11 parts of magnesium oxide, 0.17-0.35 parts of magnesium chloride, and 0.1-0.5 parts of water-resistant agent by weight, mix them well, pour them into a pelletizing machine for granulation, and obtain the core material.

[0022] (2) Weigh out 10-15 parts of rice husk ash, 5-10 parts of polyacrylamide, 2-5 parts of montmorillonite, 1-2 parts of sodium aluminate, and 12-14 parts of water by weight and mix them to obtain a slurry.

[0023] (3) Add 6 to 12 parts of the core material prepared in step (1) into the pelletizing machine, and then add 2 to 6 parts of the slurry prepared in step (2) for coating. Then cure for 7 days under natural conditions of 85±5% relative humidity and 23±2℃ temperature. Finally, sieve out particles with a particle size of 4.75mm to 15mm to obtain the high corrosion resistant artificial aggregate.

[0024] Furthermore, in step (1), water is generally sprayed simultaneously as an adhesive during granulation in the pelletizing machine.

[0025] Thirdly, embodiments of this application also provide the application of the aforementioned high corrosion-resistant artificial aggregate in the preparation of corrosion-resistant and crack-resistant cement concrete.

[0026] Fourthly, embodiments of this application also provide a corrosion-resistant and crack-resistant cement concrete comprising the aforementioned highly corrosion-resistant artificial aggregate.

[0027] Furthermore, the corrosion-resistant and crack-resistant cement concrete is made from raw materials comprising the following parts by weight:

[0028] The composition includes 0.4-1.1 parts of high corrosion resistant artificial aggregate, 1 part of cement, 1.5-1.55 parts of natural sand, 2.1-2.2 parts of natural coarse aggregate, 0.01-0.02 parts of impermeable and crack-resistant microcapsules, and 0.35-0.45 parts of water.

[0029] The natural coarse aggregate is aggregate with a particle size greater than 4.75 mm.

[0030] The natural sand is composed of particles with a diameter of 75μm to 4.75mm.

[0031] The cement may be silicate cement.

[0032] Fifthly, this application also provides a method for preparing the aforementioned corrosion-resistant and crack-resistant cement concrete, the method being:

[0033] By weight, 0.4-1.1 parts of the high corrosion-resistant artificial aggregate, 1 part of cement, 1.5-1.55 parts of natural sand, 2.1-2.2 parts of natural coarse aggregate, and 0.01-0.02 parts of impermeable and crack-resistant microcapsules are mixed evenly. 0.35-0.45 parts of water are added to the above mixture and mixed evenly to obtain the corrosion-resistant and crack-resistant cement concrete.

[0034] The corrosion-resistant and crack-resistant cement concrete provided by this invention is suitable for bridge components.

[0035] Furthermore, the impermeable and crack-resistant microcapsules are prepared by the following method:

[0036] Step 1: Emulsify 1-2 wt% sodium alginate solution with N-vinylpyrrolidone to obtain an emulsion;

[0037] Step 2: Add the emulsion dropwise at a concentration of 0.5–2 mol·L⁻¹ -1 Capsule particles were obtained by immersing the capsules in an aqueous solution of AgNO3, and then washed to obtain anti-permeability and anti-crack microcapsules.

[0038] Furthermore, the volume ratio of the sodium alginate solution to the N-vinylpyrrolidone is 1:0.25 to 0.5.

[0039] Furthermore, the sodium alginate solution preferably has a mass fraction of 1.5%.

[0040] Furthermore, the concentration of the AgNO3 aqueous solution is preferably 1 mol·L⁻¹. -1 .

[0041] Furthermore, in step two, the particle size of the impermeable and crack-resistant microcapsules obtained by granulation is 0.1 to 0.3 mm.

[0042] Compared with the prior art, the present invention has at least the following beneficial effects:

[0043] (1) This invention utilizes dredged soil from industrial waste to produce artificial aggregates, realizing waste recycling and reuse, which is of great significance to the sustainable development of society and economy and solves the problem of large amounts of waste that cannot be effectively disposed of. This invention uses polyacrylamide, montmorillonite, and sodium aluminate to modify rice husk ash, ensuring that it has a very high curing effect on chloride ions; and rice husk ash has a large specific surface area, which can adsorb a large amount of sodium aluminate and other substances, ensuring that the modified material can effectively combine with rice husk ash.

[0044] (2) The present invention uses magnesium oxychloride cement as a binder and sodium phosphate as a water-resistant agent to effectively ensure the strength and water resistance of artificial aggregates; the dredged soil contains active silicon dioxide, aluminum oxide and other substances, which will continuously generate strong hydration products under the action of magnesium hydroxide, further improving the strength of the aggregates.

[0045] (3) The anti-seepage and anti-crack microcapsule provided by the present invention has an N-vinylpyrrolidone core that can expand in volume when exposed to water. The capsule wall is a chloride ion triggering material. When the chloride ion concentration in the environment exceeds the threshold, the capsule wall ruptures and releases the anti-crack and leak-stopping material of the core, thereby achieving the purpose of precise anti-crack.

[0046] (4) The high corrosion-resistant artificial aggregate provided by this invention is a porous material, which can reduce the self-weight of bridge components while improving their resistance to chloride ion erosion. The anti-permeability and crack-resistant microcapsules have crack recognition capabilities, which can accurately seal cracks in bridge components and adsorb chloride ions. The high corrosion-resistant artificial aggregate and anti-corrosion and crack-resistant cement concrete of this invention can reduce the diffusion of external chloride ions into concrete from both chemical reaction and physical adsorption aspects, greatly preventing or delaying the degree of chloride ion erosion on bridge structures. Detailed Implementation

[0047] The present invention will now be described in detail with reference to specific embodiments. These embodiments will help those skilled in the art to further understand the present invention, but do not limit the invention in any way.

[0048] It should be noted that, for those skilled in the art, several changes and improvements can be made without departing from the concept of the present invention, including any combination of the various examples.

[0049] Example 1

[0050] This embodiment provides a corrosion-resistant and crack-resistant cement concrete suitable for bridge components. By mass percentage, the proportions of high corrosion-resistant artificial aggregate, silicate cement, water, natural sand (particle size 0.15mm~4.75mm), natural coarse aggregate (particle size greater than 4.75mm), and impermeable and crack-resistant microcapsules are 0.6 parts, 1 part, 0.38 parts, 1.5 parts, 2.2 parts, and 0.015 parts, respectively.

[0051] High corrosion-resistant artificial aggregate, cement, natural sand, natural coarse aggregate and anti-seepage and crack-resistant microcapsules are mixed evenly, water is added and mixed evenly to obtain anti-corrosion and crack-resistant cement concrete.

[0052] The specific preparation process of the high corrosion-resistant artificial aggregate described in this embodiment is as follows:

[0053] S1, weigh 45 parts of dredged soil, 5 parts of calcium oxide, 10 parts of magnesium oxide, 0.25 parts of magnesium chloride, and 0.3 parts of sodium phosphate by weight, mix them well, pour them into a pelletizing machine for water spraying and granulation to obtain the core material;

[0054] S2, by weight, weigh 10 parts rice husk ash, 8 parts polyacrylamide, 3 parts montmorillonite, 1.5 parts sodium aluminate, and 12 parts water and mix them to obtain a slurry;

[0055] S3. Add 4 parts of the slurry prepared in step S2 into the pelletizing machine, and then add 9 parts of the core material prepared in step S1 to coat the pellet. Then cure it under natural conditions of 85±5% relative humidity and 23±2℃ for 7 days. Finally, sieve out the particles with a particle size of 4.75mm to 15mm to obtain the high corrosion resistant artificial aggregate.

[0056] The preparation steps of the anti-permeability and anti-crack microcapsules in this embodiment are as follows:

[0057] Step 1: Emulsify 300 mL of 1.5 wt% sodium alginate solution with 150 mL of N-vinylpyrrolidone using ultrasonication to obtain an O / W emulsion.

[0058] Step 2: Use a syringe to drop the emulsion into a 1 mol·L⁻¹ solution. -1 Microcapsules were formed in an aqueous solution of AgNO3; after washing with deionized water, anti-permeability and anti-crack microcapsules were obtained.

[0059] The anti-permeability and anti-crack microcapsules in this embodiment have a particle size of 0.15 mm.

[0060] The apparent density, compressive strength and chloride ion curing rate of the high corrosion-resistant artificial aggregate prepared in this embodiment were tested, and the test results are shown in Table 1; the impermeability of the molded corrosion-resistant and crack-resistant cement concrete was tested, and the test results are shown in Table 2.

[0061] Example 2

[0062] This embodiment provides a corrosion-resistant and crack-resistant cement concrete suitable for bridge components. The mass percentages of high corrosion-resistant artificial aggregate, cement, water, natural sand, natural coarse aggregate, and impermeable and crack-resistant microcapsules are 1.1, 1, 0.45, 1.55, 2.1, and 0.02, respectively.

[0063] High corrosion-resistant artificial aggregate, cement, natural sand, natural coarse aggregate and anti-seepage and crack-resistant microcapsules are mixed evenly, water is added and mixed evenly to obtain anti-corrosion and crack-resistant cement concrete.

[0064] The specific preparation process of the high corrosion-resistant artificial aggregate in this embodiment is as follows:

[0065] S1, weigh out 35 parts of dredged soil, 7 parts of calcium oxide, 5 parts of magnesium oxide, 0.17 parts of magnesium chloride, and 0.1 parts of sodium phosphate by weight, mix them well, pour them into a pelletizing machine for water spraying and granulation to obtain the core material;

[0066] S2, weigh out 15 parts rice husk ash, 10 parts polyacrylamide, 5 parts montmorillonite, 2 parts sodium aluminate, and 14 parts water by weight and mix them to obtain a slurry.

[0067] S3. Add 6 parts of the slurry prepared in step S2 into the pelletizing machine, and then add 12 parts of the core material prepared in step S1 for coating. Then cure for 7 days under natural conditions of 85±5% relative humidity and 23±2℃. Finally, sieve out the particles with a particle size of 4.75mm to 15mm to obtain the high corrosion resistant artificial aggregate.

[0068] The preparation steps of the anti-permeability and anti-crack microcapsules in this embodiment are as follows:

[0069] Step 1: Ultrasonically emulsify 300 mL of 1.5 wt% sodium alginate solution with 90 mL of N-vinylpyrrolidone to obtain an emulsion;

[0070] Step 2: Use a syringe to drop the emulsion into a 1 mol·L⁻¹ solution. -1 Microcapsules were formed in an aqueous solution of AgNO3; after washing with deionized water, the anti-permeability and anti-crack microcapsules were obtained.

[0071] The anti-permeability and anti-crack microcapsules in this embodiment have a particle size of 0.1 mm.

[0072] The apparent density, compressive strength and chloride ion curing rate of the high corrosion-resistant artificial aggregate prepared in this embodiment were tested, and the test results are shown in Table 1. The mechanical properties and impermeability of the molded corrosion-resistant and crack-resistant cement concrete were tested, and the test results are shown in Table 2.

[0073] Comparative Example 1

[0074] This comparative example did not use a shelling process to produce artificial aggregates.

[0075] Specifically, the difference between Comparative Example 1 and Example 1 is that Comparative Example 1 does not include step S2 of Example 1, and in step S3, the core material is cured under natural conditions for 7 days, and then particles with a particle size of 4.75 mm to 15 mm are screened out to obtain artificial aggregate.

[0076] All other implementation methods in Comparative Example 1 are the same as those in Example 1.

[0077] Comparative Example 2

[0078] This comparative example did not use sodium phosphate-modified artificial aggregate.

[0079] Specifically, the difference between Comparative Example 2 and Example 1 is that the amount of sodium phosphate used in step S1 of Comparative Example 2 is 0.

[0080] All other implementation methods in Comparative Example 2 are the same as those in Example 1.

[0081] Comparative Example 3

[0082] This comparative example did not use highly corrosion-resistant artificial aggregates to form corrosion-resistant and crack-resistant cement concrete.

[0083] Specifically, the aggregates used in Comparative Example 3 are all natural aggregates, which are formulated according to the following formula: the mass parts of cement, water, natural sand, natural coarse aggregate, and anti-seepage and anti-crack microcapsules are 1, 0.38, 1.5, 2.6, and 0.015, respectively.

[0084] All other implementation methods in Comparative Example 3 are the same as those in Example 1.

[0085] Comparative Example 4

[0086] This comparative example did not use impermeable and crack-resistant microcapsule molding for corrosion-resistant and crack-resistant cement concrete.

[0087] Specifically, Comparative Example 4 did not use anti-seepage and anti-crack microcapsule molding to form anti-corrosion and anti-crack cement concrete. Instead, it was prepared according to the following formula: the mass parts of high anti-corrosion artificial aggregate, cement, water, natural sand, and natural coarse aggregate were 0.6, 1, 0.38, 1.5, and 2.2, respectively.

[0088] All other implementation methods in Comparative Example 4 are the same as those in Example 1.

[0089] It should be noted that the apparent density and compressive strength of artificial aggregates were tested according to GB / T17431-2010 "Standard for Lightweight Aggregates and Their Test Methods"; the 28-day compressive and flexural strength of molded concrete were tested according to GB / T 50107-2010 "Standard for Testing and Evaluation of Concrete Strength"; the chloride ion penetration resistance of corrosion-resistant and crack-resistant cement concrete was measured using the electrical flux method and the rapid chloride ion penetration coefficient method (RCM); the concrete specimens were pre-damaged under 60% ultimate load, and then the intact samples and the pre-damaged samples were immersed in 3.5% NaCl solution for 3 days, and then the electrical flux of the samples was tested to evaluate the corrosion resistance and crack resistance of cement concrete.

[0090] Table 1 shows the test results of apparent density, compressive strength, and chloride ion curing rate of the artificial aggregates in the examples and comparative examples. It can be seen that the compressive strengths of Example 1 and Example 2 are 5.3 and 5.2 MPa, respectively, and the apparent density reaches 1400 kg / m³. 3The above meets the specifications. As can be seen from Comparative Examples 1 and 2, the strength of the uncoated aggregate is lower than that of the coated aggregate, and the strength reduction is most significant in the aggregate without sodium phosphate modification. Comparative Example 1 has the lowest chloride ion curing rate, which is because the uncoated aggregate lacks chloride ion adsorption capacity.

[0091] Table 1

[0092] Example Example 1 Example 2 Comparative Example 1 Comparative Example 2 <![CDATA[Apparent density (kg / m 3 )]]> 1480 1430 1320 1110 Cylinder compressive strength (MPa) 5.3 5.2 4.9 3.6 Chloride ion curing rate (%) 81.5 79.3 62.4 76.9

[0093] Table 2 shows the test results of compressive strength, flexural strength, and electrical flux for the examples and comparative examples. It can be seen that the mechanical properties of the concrete formed from the unmodified sodium phosphate aggregate in Comparative Example 2 decreased, and the electrical flux was high, indicating that Comparative Example 2 had poor impermeability and crack resistance, and poor chloride ion adsorption capacity. Comparative Example 3 used natural aggregate, which had high strength, but also high electrical flux. Although anti-impermeability and crack-resistant microcapsules were added to Comparative Example 3, it lacked the chloride ion solidification ability of highly corrosion-resistant artificial aggregate, thus resulting in poor impermeability and crack resistance. Comparative Example 4 showed little change in mechanical properties, but had the highest electrical flux, indicating that the anti-cracking and anti-impermeability microcapsules of the present invention can effectively improve the crack resistance and impermeability of concrete components.

[0094] Table 2

[0095]

[0096] The above description is merely a preferred embodiment of this application and is not intended to limit this application in any form or substance. It should be noted that those skilled in the art can make various improvements and additions without departing from the method of this application, and these improvements and additions should also be considered within the scope of protection of this invention. Any modifications, alterations, and equivalent variations made by those skilled in the art without departing from the spirit and scope of this application, based on the disclosed technical content, are equivalent embodiments of this application. Furthermore, any modifications, alterations, and variations made to the above embodiments based on the essential technology of this application still fall within the scope of the technical solution of this application.

Claims

1. A highly corrosion-resistant artificial aggregate, characterized in that, The highly corrosion-resistant artificial aggregate has a core-shell structure, which includes a core material and an outer shell material wrapped around the core material; The core material is made of the following materials in parts by weight: 35-55 parts dredged soil, 2-7 parts calcium oxide, 5-11 parts magnesium oxide, 0.17-0.35 parts magnesium chloride, and 0.1-0.5 parts water-resistant agent; The outer shell material is made of the following materials in parts by weight: 10-15 parts rice husk ash, 5-10 parts polyacrylamide, 2-5 parts montmorillonite, 1-2 parts sodium aluminate, and 12-14 parts water. The ratio of the amount of the core material to the amount of the outer shell material is 6-12:2-6.

2. The high corrosion-resistant artificial aggregate as described in claim 1, characterized in that, The water-resistant agent is one or more of sodium phosphate, ferrous sulfate, magnesium sulfate, or alum.

3. The high corrosion-resistant artificial aggregate as described in claim 1, characterized in that, The core material is prepared by the following method: Mix 35-55 parts of dredged soil, 2-7 parts of calcium oxide, 5-11 parts of magnesium oxide, 0.17-0.35 parts of magnesium chloride, and 0.1-0.5 parts of water-resistant agent, and granulate to obtain the core material.

4. The high corrosion-resistant artificial aggregate as described in claim 1, characterized in that, The outer shell material is prepared by mixing all the outer shell raw materials into a slurry, adding 2 to 6 parts of the slurry to 6 to 12 parts of the core material for coating, curing naturally for 7 days, and then screening to obtain the high corrosion resistant artificial aggregate.

5. The method for preparing high-corrosion-resistant artificial aggregate as described in any one of claims 1 to 4, characterized in that, The method includes the following steps: (1) Weigh out 35-55 parts of dredged soil, 2-7 parts of calcium oxide, 5-11 parts of magnesium oxide, 0.17-0.35 parts of magnesium chloride, and 0.1-0.5 parts of water-resistant agent by weight, mix them well, pour them into a pelletizing machine for granulation, and obtain the core material. (2) Weigh out 10-15 parts of rice husk ash, 5-10 parts of polyacrylamide, 2-5 parts of montmorillonite, 1-2 parts of sodium aluminate, and 12-14 parts of water by weight and mix them to obtain a slurry. (3) Add 6 to 12 parts of the core material prepared in step (1) into the pelletizing machine, and then add 2 to 6 parts of the slurry prepared in step (2) for coating. Then cure for 7 days under natural conditions of 85±5% relative humidity and 23±2℃ temperature. Finally, sieve out particles with a particle size of 4.75mm to 15mm to obtain high corrosion resistant artificial aggregate.

6. The application of the high corrosion-resistant artificial aggregate as described in any one of claims 1 to 4 in the preparation of corrosion-resistant and crack-resistant cement concrete.

7. A corrosion-resistant and crack-resistant cement concrete comprising the high corrosion-resistant artificial aggregate as described in any one of claims 1 to 4.

8. The anti-corrosion and crack-resistant cement concrete as described in claim 7, characterized in that, The corrosion-resistant and crack-resistant cement concrete is made from the following raw materials in parts by weight: The composition includes 0.4-1.1 parts of high corrosion resistant artificial aggregate, 1 part of cement, 1.5-1.55 parts of natural sand, 2.1-2.2 parts of natural coarse aggregate, 0.01-0.02 parts of impermeable and crack-resistant microcapsules, and 0.35-0.45 parts of water.

9. The anti-corrosion and crack-resistant cement concrete as described in claim 8, characterized in that, The impermeable and crack-resistant microcapsules were prepared by the following method: Step 1: Emulsify 1-2 wt% sodium alginate solution with N-vinylpyrrolidone to obtain an emulsion; Step 2: Add the emulsion dropwise at a concentration of 0.5–2 mol·L⁻¹ -1 Capsule particles were obtained by immersing the capsules in an aqueous solution of AgNO3, and the anti-permeability and anti-crack microcapsules were prepared by washing.

10. The application of corrosion-resistant and crack-resistant cement concrete as described in claim 8 or 9 in bridge components.

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