A polymer cement-based composite material, a method for preparing the same and applications thereof

Abstract

The application relates to the technical field of concrete, and discloses a polymer cement-based composite material and a preparation method and application thereof. According to mass parts, the polymer cement-based composite material comprises the following preparation raw materials: cementitious material 80-120 parts, aggregate 160-240 parts, polymer monomer 1-5 parts, initiator 0.04-0.07 parts, crosslinking agent 0.01-0.03 parts and mixing water 35-55 parts; the polymer monomer is a combination of a sulfonic acid-based vinyl monomer and an acrylic monomer. In-situ copolymerization is carried out by introducing the sulfonic acid-based vinyl monomer and the acrylic monomer, the synergistic effect of sulfonic acid groups and cement hydration products is utilized, the negative influence of pure acrylic monomers on early hydration is significantly relieved, when the sulfonic acid-based vinyl monomer accounts for 30% of the total amount of polymer monomers, the 3-day flexural strength of the material is about 7.5 times that of a pure acrylic monomer system, the 28-day flexural strength is higher than that of the pure acrylic monomer system, and the compressive strength is equivalent, and the defects of traditional modified products, such as toughness increase and strength decrease or early loss, are overcome.

Description

Technical Field

[0001] This invention relates to the field of concrete technology, and in particular to a polymer cement-based composite material, its preparation method, and its application. Background Technology

[0002] Cement-based materials are the most widely used and consumed basic structural materials in modern construction engineering. They possess core advantages such as readily available raw materials, controllable strength, excellent durability, and low cost, making them widely applicable in various infrastructure construction fields, including housing, roads and bridges, water conservancy projects, and underground structures. They are key materials supporting the development of the civil engineering industry. However, from a microstructural perspective, cement-based materials are inherently porous, heterogeneous, and brittle. During their hydration and hardening process, inherent defects such as microcracks, pores, and interface transition zones inevitably arise. These defects significantly reduce the material's toughness and flexural strength, making it prone to cracking and breakage under load, temperature stress, and wet-dry cycles, directly affecting the safety, stability, and service life of the structure. Therefore, overcoming these defects and preparing cement-based materials with high toughness and high flexural strength has always been a research hotspot in the field of building materials.

[0003] To improve the brittleness of cement-based materials, the industry commonly uses polymer incorporation for modification. Traditional modification techniques mainly involve directly adding polymer emulsions and polymer powders, leveraging the bridging and filling effects of polymers to enhance material toughness. However, this approach suffers from several insurmountable drawbacks in practical applications: Firstly, polymers are difficult to disperse uniformly in cement paste, easily leading to agglomeration. This results in poor compatibility and weak interfacial bonding between the polymer and cement hydration products, preventing the formation of a stable composite structure and significantly reducing the modification effect. Secondly, traditional polymer addition processes are complex and difficult to operate, requiring additional emulsification, dispersion, and mixing steps. This not only increases production costs but also hinders large-scale on-site application, resulting in insufficient engineering practicality and economic efficiency.

[0004] Based on the aforementioned issues, in-situ polymerization of polymer monomers to modify cement-based materials has become a research hotspot in recent years. This technology first uniformly disperses small-molecule polymer monomers in cement slurry, and then initiates a polymerization reaction in situ under cement hydration conditions to generate high-molecular polymers. Compared with traditional modification methods, in-situ polymerization technology can significantly improve the dispersion uniformity of polymers in the cement matrix, enhance the interfacial compatibility between the polymer and the cement matrix, and the in-situ generated polymers can directly fill the micropores inside the material, optimizing the density of the matrix structure. At the same time, the preparation process is simpler and lower in cost, showing good prospects for industrial application.

[0005] However, existing in-situ polymerization systems still face key technological bottlenecks. Commonly used carboxyl monomers, such as sodium acrylate (SA), can severely interfere with and delay the early hydration process of cement during in-situ polymerization, directly leading to a significant reduction in the early-age strength (e.g., 3 days) of composite materials, which cannot meet the requirements of early strength for engineering construction. At the same time, most monomer systems are unable to simultaneously coordinate the reaction rates of organic polymerization and cement hydration, making it difficult to stably form an organic-inorganic interpenetrating network structure. This makes it difficult to balance the early strength of the material with its mid-to-late-stage toughness and mechanical properties, thus restricting the practical application and development of in-situ polymerized modified cement-based materials. Summary of the Invention

[0006] The present invention aims to at least solve one of the aforementioned technical problems existing in the prior art. Therefore, one object of the present invention is to provide a polymer cement-based composite material.

[0007] The second objective of this invention is to provide a method for preparing this polymer cement-based composite material.

[0008] The third objective of this invention is to provide applications of this polymer cementitious composite material.

[0009] To achieve the above objectives, the technical solution adopted by the present invention is as follows: The first aspect of the present invention provides a polymer cement-based composite material, comprising, by weight, the following raw materials: 80-120 parts of cementitious material, 160-240 parts of aggregate, 1-5 parts of polymeric monomer, 0.04-0.07 parts of initiator, 0.01-0.03 parts of crosslinking agent, and 35-55 parts of mixing water; wherein the polymeric monomer is a combination of sulfonic acid vinyl monomer and acrylic monomer.

[0010] In some embodiments of the present invention, the polymer cement-based composite material comprises, by weight, the following raw materials: 90-110 parts of cementitious material, 180-220 parts of aggregate, 3-5 parts of polymeric monomer, 0.05-0.07 parts of initiator, 0.01-0.02 parts of crosslinking agent, and 40-50 parts of mixing water.

[0011] In some embodiments of the present invention, the amount of the sulfonic acid-based vinyl monomer accounts for more than 10% of the total amount of the polymeric monomer.

[0012] In some preferred embodiments of the present invention, the amount of the sulfonic acid-based vinyl monomer accounts for 20%-40% of the total amount of the polymeric monomer.

[0013] In some more preferred embodiments of the present invention, the amount of the sulfonic acid-based vinyl monomer accounts for 30% of the total amount of the polymeric monomer.

[0014] In some embodiments of the present invention, the sulfonic acid vinyl monomer includes 2-acrylamide-2-methylpropanesulfonic acid (AMPS).

[0015] In some embodiments of the present invention, the acrylic monomer includes sodium acrylate (SA).

[0016] In some preferred embodiments of the present invention, the polymeric monomer is a compound of 2-acrylamide-2-methylpropanesulfonic acid and sodium acrylate.

[0017] In some embodiments of the present invention, the cementing material comprises ordinary Portland cement with a strength grade of 42.5.

[0018] In some embodiments of the present invention, the aggregate gradation includes a three-gradation of 1.0-2.0 mm, 0.50-1.0 mm, and 0.08-0.50 mm.

[0019] In some preferred embodiments of the present invention, the aggregate comprises Chinese ISO standard sand.

[0020] In some embodiments of the present invention, the initiator includes at least one of ammonium persulfate, benzoyl peroxide, and potassium persulfate.

[0021] In some preferred embodiments of the present invention, the initiator is ammonium persulfate (APS).

[0022] In some embodiments of the present invention, the crosslinking agent includes at least one of N,N'-methylenebisacrylamide, polyethylene glycol diacrylate, polyethylene glycol dimethacrylate, and trimethylolpropane triacrylate.

[0023] In some preferred embodiments of the present invention, the crosslinking agent is N,N'-methylenebisacrylamide (MBA).

[0024] A second aspect of the present invention provides a method for preparing the polymer cement-based composite material described in the first aspect of the present invention, comprising the following steps: S1. Sulfonic acid vinyl monomers, acrylic monomers, initiators, and crosslinking agents are mixed with water to form sulfonic acid vinyl monomer solutions, acrylic monomer solutions, initiator solutions, and crosslinking agent solutions; S2. After mixing the cementitious material and aggregate, add the acrylic monomer solution, the sulfonic acid vinyl monomer solution, the initiator solution and the crosslinking agent solution in sequence, and stir to form a slurry; S3. The slurry is shaped and in-situ polymerized during the hydration process to obtain the polymer cement-based composite material.

[0025] In some embodiments of the present invention, in step S1, the mass ratio of the sulfonic acid vinyl monomer to water is 1:(4-6); the mixing process is supplemented by stirring for 1.5-2.5 hours.

[0026] In some embodiments of the present invention, in step S1, the mass ratio of the acrylic monomer to water is 1:(2-4); the mixing process is supplemented by stirring for 1.5-2.5 hours.

[0027] In some embodiments of the present invention, in step S1, the mass ratio of the initiator to water is 1:(16-24); the mixing process is supplemented by stirring for 20-40 minutes.

[0028] In some embodiments of the present invention, in step S1, the mass ratio of the crosslinking agent to water is 1:(160-240); the mixing process is supplemented by water bath heating and stirring, the water bath heating temperature is 30-40°C, and the stirring time is 20-40 min.

[0029] In some embodiments of the present invention, in step S2, the mixing process of the cementitious material and the aggregate is supplemented by stirring, and the stirring time is 2-4 minutes.

[0030] In some embodiments of the present invention, in step S2, the stirring includes stirring at low speed for 1-2 minutes, letting it stand for 20-40 seconds, and then stirring at high speed for 1-2 minutes; wherein the low-speed stirring has a self-speed rate of 130-150 rpm and a common speed rate of 50-70 rpm; the high-speed stirring has a self-speed rate of 270-300 rpm and a common speed rate of 110-140 rpm.

[0031] In some preferred embodiments of the present invention, in step S2, the self-speed rate of the low-speed stirring is 135-145 rpm, and the common speed rate is 57-67 rpm.

[0032] In some preferred embodiments of the present invention, in step S2, the self-speed rate of the high-speed stirrer is 275-295 rpm, and the public speed rate is 115-135 rpm.

[0033] In some embodiments of the present invention, step S3 specifically includes: placing the slurry in a mold, compacting and smoothing it, sealing it, and then performing in-situ polymerization.

[0034] In some embodiments of the present invention, in step S3, the in-situ polymerization time is 38-58 hours.

[0035] In some preferred embodiments of the present invention, in step S3, the in-situ polymerization time is 43-53 hours.

[0036] In some embodiments of the present invention, step S3, after the in-situ polymerization is completed, also includes demolding and curing operations.

[0037] In some embodiments of the present invention, in step S3, the curing temperature is 20±2℃ and the relative humidity is not less than 90%.

[0038] In some embodiments of the present invention, in step S3, the curing time is 3-28 days.

[0039] The third aspect of the present invention provides the application of the polymer cement-based composite material described in the first aspect of the present invention in the preparation of structural components for building engineering, road pavements, and hydraulic engineering components.

[0040] Compared with the prior art, the beneficial effects of the present invention are: 1) The polymer cement-based composite material provided by this invention introduces sulfonic acid vinyl monomers (such as 2-acrylamide-2-methylpropanesulfonic acid) and acrylic monomers for in-situ copolymerization. By utilizing the synergistic effect of sulfonic acid groups and cement hydration products, the negative impact of pure acrylic monomers on early hydration is significantly alleviated. When the amount of sulfonic acid vinyl monomers is 30% of the total amount of polymer monomers, the 3-day flexural strength of the composite material is about 7.5 times that of the pure acrylic monomer system, achieving a breakthrough improvement in early strength. It also constructs a stable organic-inorganic interpenetrating network structure, which continues to play a toughening role in the middle and late stages. The 28-day flexural strength is slightly higher than that of the pure acrylic monomer system, and the compressive strength is comparable, overcoming the defects of traditional modified products that toughen but reduce strength or suffer early loss. 2) The preparation method of polymer cement-based composite material provided by the present invention is simple, requires no special equipment, and has controllable raw material costs, which is conducive to its engineering application. 3) The polymer cement-based composite material provided by this invention has excellent early and late mechanical properties and can be widely used in building structural components, road pavement and water conservancy projects. Attached Figure Description

[0041] Figure 1 This is a comparison diagram of the flexural strength of cement-based material specimens in Examples 1-4 and the comparative example; Figure 2 The image shows a comparison of the compressive strength of cement-based material specimens in Examples 1-4 and the comparative examples. Detailed Implementation

[0042] The present invention will be further described in detail below through specific embodiments. Unless otherwise specified, the raw materials, reagents, or apparatus used in the embodiments and comparative examples are all available from conventional commercial sources or can be obtained by existing technical methods. Unless otherwise specified, the test or experimental methods are conventional methods in the art.

[0043] Note: The aggregate used in the following examples and comparative examples is Chinese ISO standard sand, with a three-gradation of 1.0-2.0mm, 0.50-1.0mm and 0.08-0.50mm; Unless otherwise specified, "parts" in the following examples and comparative examples refer to "parts by mass".

[0044] Example 1 This embodiment prepares a polymer cementitious composite material. The raw materials and their amounts are shown in Table 1. Table 1. Raw materials and dosages used in the preparation of polymer cement-based composite materials in Example 1

[0045] Of these, 2-acrylamide-2-methylpropanesulfonic acid accounts for 10% of the total amount of polymer monomers.

[0046] The preparation steps are as follows: S11. Mix 2-acrylamide-2-methylpropanesulfonic acid with water at a mass ratio of 1:5 and stir for 2 hours until homogeneous to obtain a 2-acrylamide-2-methylpropanesulfonic acid solution; mix sodium acrylate with water at a mass ratio of 1:3 and stir for 2 hours until homogeneous to obtain a sodium acrylate solution; mix ammonium persulfate with water at a mass ratio of 1:20 and stir for 30 minutes until homogeneous to obtain an ammonium persulfate solution; mix N,N'-methylenebisacrylamide with water at a mass ratio of 1:200 and stir for 30 minutes in a water bath at 35°C until homogeneous to obtain an N,N'-methylenebisacrylamide solution. S21. Place 42.5 grade ordinary Portland cement and Chinese ISO standard sand in a mixing pot and mix at low speed for 3 minutes to mix evenly. Then add sodium acrylate solution, 2-acrylamide-2-methylpropanesulfonic acid solution, ammonium persulfate solution and N,N'-methylenebisacrylamide solution in sequence. First, mix at low speed for 1 minute, let stand for 30 seconds and then mix at high speed for 1 minute to obtain a slurry. The rotation speed of the low-speed mixing is 140 rpm and the rotation speed is 62 rpm. The rotation speed of the high-speed mixing is 280 rpm and the rotation speed is 120 rpm. S31. Pour the slurry into the mold (4cm×4cm×16cm), vibrate it 20 times, smooth it, cover it with plastic wrap, and carry out in-situ polymerization for 48 hours during the cement hydration process. S32. After demolding, the material is cured for 28 days under standard curing conditions (temperature 20±2℃, relative humidity ≥90%) to obtain polymer cement-based composite material.

[0047] Example 2 This embodiment prepares a polymer cementitious composite material. The raw materials and their amounts are shown in Table 2. Table 2. Raw materials and dosages used in the preparation of polymer cement-based composite materials in Example 2

[0048] Of these, 2-acrylamide-2-methylpropanesulfonic acid accounts for 20% of the total amount of polymer monomers.

[0049] The preparation steps are as follows: S11. Mix 2-acrylamide-2-methylpropanesulfonic acid with water at a mass ratio of 1:5 and stir for 2 hours until homogeneous to obtain a 2-acrylamide-2-methylpropanesulfonic acid solution; mix sodium acrylate with water at a mass ratio of 1:3 and stir for 2 hours until homogeneous to obtain a sodium acrylate solution; mix ammonium persulfate with water at a mass ratio of 1:20 and stir for 30 minutes until homogeneous to obtain an ammonium persulfate solution; mix N,N'-methylenebisacrylamide with water at a mass ratio of 1:200 and stir for 30 minutes in a water bath at 35°C until homogeneous to obtain an N,N'-methylenebisacrylamide solution. S21. Place 42.5 grade ordinary Portland cement and Chinese ISO standard sand in a mixing pot and mix at low speed for 3 minutes to mix evenly. Then add sodium acrylate solution, 2-acrylamide-2-methylpropanesulfonic acid solution, ammonium persulfate solution and N,N'-methylenebisacrylamide solution in sequence. First, mix at low speed for 1 minute, let stand for 30 seconds and then mix at high speed for 1 minute to obtain a slurry. The rotation speed of the low-speed mixing is 140 rpm and the rotation speed is 62 rpm. The rotation speed of the high-speed mixing is 280 rpm and the rotation speed is 120 rpm. S31. Pour the slurry into the mold (4cm×4cm×16cm), vibrate it 20 times, smooth it, cover it with plastic wrap, and carry out in-situ polymerization for 48 hours during the cement hydration process. S32. After demolding, the material is cured for 28 days under standard curing conditions (temperature 20±2℃, relative humidity ≥90%) to obtain polymer cement-based composite material.

[0050] Example 3 This embodiment prepares a polymer cementitious composite material. The raw materials and their amounts are shown in Table 3. Table 3. Raw materials and dosages for the preparation of polymer cement-based composite materials in Example 3

[0051] Of these, 2-acrylamide-2-methylpropanesulfonic acid accounts for 30% of the total amount of polymer monomers.

[0052] The preparation steps are as follows: S11. Mix 2-acrylamide-2-methylpropanesulfonic acid with water at a mass ratio of 1:5 and stir for 2 hours until homogeneous to obtain a 2-acrylamide-2-methylpropanesulfonic acid solution; mix sodium acrylate with water at a mass ratio of 1:3 and stir for 2 hours until homogeneous to obtain a sodium acrylate solution; mix ammonium persulfate with water at a mass ratio of 1:20 and stir for 30 minutes until homogeneous to obtain an ammonium persulfate solution; mix N,N'-methylenebisacrylamide with water at a mass ratio of 1:200 and stir for 30 minutes in a water bath at 35°C until homogeneous to obtain an N,N'-methylenebisacrylamide solution. S21. Place 42.5 grade ordinary Portland cement and Chinese ISO standard sand in a mixing pot and mix at low speed for 3 minutes to mix evenly. Then add sodium acrylate solution, 2-acrylamide-2-methylpropanesulfonic acid solution, ammonium persulfate solution and N,N'-methylenebisacrylamide solution in sequence. First, mix at low speed for 1 minute, let stand for 30 seconds and then mix at high speed for 1 minute to obtain a slurry. The rotation speed of the low-speed mixing is 140 rpm and the rotation speed is 62 rpm. The rotation speed of the high-speed mixing is 280 rpm and the rotation speed is 120 rpm. S31. Pour the slurry into the mold (4cm×4cm×16cm), vibrate it 20 times, smooth it, cover it with plastic wrap, and carry out in-situ polymerization for 48 hours during the cement hydration process. S32. After demolding, the material is cured for 28 days under standard curing conditions (temperature 20±2℃, relative humidity ≥90%) to obtain polymer cement-based composite material.

[0053] Example 4 This embodiment prepares a polymer cementitious composite material. The raw materials and their amounts are shown in Table 4. Table 4. Raw materials and dosages used in the preparation of polymer cement-based composite materials in Example 4

[0054] Of these, 2-acrylamide-2-methylpropanesulfonic acid accounts for 40% of the total amount of polymer monomers.

[0055] The preparation steps are as follows: S11. Mix 2-acrylamide-2-methylpropanesulfonic acid with water at a mass ratio of 1:5 and stir for 2 hours until homogeneous to obtain a 2-acrylamide-2-methylpropanesulfonic acid solution; mix sodium acrylate with water at a mass ratio of 1:3 and stir for 2 hours until homogeneous to obtain a sodium acrylate solution; mix ammonium persulfate with water at a mass ratio of 1:20 and stir for 30 minutes until homogeneous to obtain an ammonium persulfate solution; mix N,N'-methylenebisacrylamide with water at a mass ratio of 1:200 and stir for 30 minutes in a water bath at 35°C until homogeneous to obtain an N,N'-methylenebisacrylamide solution. S21. Place 42.5 grade ordinary Portland cement and Chinese ISO standard sand in a mixing pot and mix at low speed for 3 minutes to mix evenly. Then add sodium acrylate solution, 2-acrylamide-2-methylpropanesulfonic acid solution, ammonium persulfate solution and N,N'-methylenebisacrylamide solution in sequence. First, mix at low speed for 1 minute, let stand for 30 seconds and then mix at high speed for 1 minute to obtain a slurry. The rotation speed of the low-speed mixing is 140 rpm and the rotation speed is 62 rpm. The rotation speed of the high-speed mixing is 280 rpm and the rotation speed is 120 rpm. S31. Pour the slurry into the mold (4cm×4cm×16cm), vibrate it 20 times, smooth it, cover it with plastic wrap, and carry out in-situ polymerization for 48 hours during the cement hydration process. S32. After demolding, the material is cured for 28 days under standard curing conditions (temperature 20±2℃, relative humidity ≥90%) to obtain polymer cement-based composite material.

[0056] Comparative Example This comparative example prepares a polymer cementitious composite material. The raw materials and their amounts are shown in Table 5. Table 5. Raw materials and dosages used in the preparation of polymer cement-based composite materials in the comparative examples.

[0057] The preparation steps are as follows: S11. Sodium acrylate and water are mixed at a mass ratio of 1:3 and stirred for 2 hours to obtain a sodium acrylate solution; ammonium persulfate and water are mixed at a mass ratio of 1:20 and stirred for 30 minutes to obtain an ammonium persulfate solution; N,N'-methylenebisacrylamide and water are mixed at a mass ratio of 1:200 and stirred for 30 minutes in a water bath at 35°C to obtain an N,N'-methylenebisacrylamide solution. S21. Place 42.5 grade ordinary Portland cement and Chinese ISO standard sand in a mixing pot and mix at low speed for 3 minutes until uniform. Then add sodium acrylate solution, ammonium persulfate solution and N,N'-methylenebisacrylamide solution in sequence. First, mix at low speed for 1 minute, let stand for 30 seconds and then mix at high speed for 1 minute to obtain a slurry. The rotation speed of the low-speed mixing is 140 rpm and the rotation speed is 62 rpm. The rotation speed of the high-speed mixing is 280 rpm and the rotation speed is 120 rpm. S31. Pour the slurry into the mold (4cm×4cm×16cm), vibrate it 20 times, smooth it, cover it with plastic wrap, and carry out in-situ polymerization for 48 hours during the cement hydration process. S32. After demolding, the material is cured for 28 days under standard curing conditions (temperature 20±2℃, relative humidity ≥90%) to obtain polymer cement-based composite material.

[0058] Performance testing Referring to GB / T 17671-2021 "Test Method for Strength of Cement Mortar (ISO Method)", the flexural strength and compressive strength of the cement-based material specimens prepared in Examples 1-4 and the comparative examples were tested: Table 6. Flexural strength (MPa) of cement-based material specimens in Examples 1-4 and Comparative Examples

[0059] Table 7 Compressive strength (MPa) of cement-based material specimens in Examples 1-4 and Comparative Examples

[0060] Table 6 shows the flexural strength of the cement-based material specimens in Examples 1-4 and the comparative examples. Figure 1 Table 7 shows a comparison of the flexural strength of the cement-based material specimens in Examples 1-4 and the comparative example. Table 7 shows the compressive strength of the cement-based material specimens in Examples 1-4 and the comparative example. Figure 2 The chart shows a comparison of the compressive strength of cement-based material specimens in Examples 1-4 and the comparative example, as shown in Tables 6 and 7. Figure 1 and Figure 2It is known that the pure sodium acrylate monomer (SA) system severely inhibits early hydration of cement, resulting in a 3-day flexural strength of only 0.9 MPa and a compressive strength of only 4.6 MPa, leading to early-age performance failure. With the increase of the proportion of 2-acrylamido-2-methylpropanesulfonic acid (AMPS), the early hydration inhibition phenomenon of the composite material is significantly alleviated, and the 3-day flexural and compressive strengths are rapidly repaired and significantly improved. When the proportion of AMPS is in the range of 20%-40%, the composite material can achieve the goal of no loss of early-age strength and significant toughening effect in the long term. Among them, when the proportion of AMPS is 30%, the improvement effect is optimal, with the 3-day flexural strength increasing to 6.7 MPa and the compressive strength increasing to 15.6 MPa. At the same time, the 5-day, 7-day, and 28-day flexural strengths are all higher than those of the pure SA system, and the compressive strength remains stable. This achieves synergistic improvement of early-age strength repair and long-term toughening enhancement, fundamentally overcoming the early strength defects of the pure SA in-situ polymerization system, and has good engineering application prospects.

Claims

1. A polymer cementitious composite material, characterized in that, The preparation materials, by weight, include the following raw materials: 80-120 parts of cementitious material, 160-240 parts of aggregate, 1-5 parts of polymeric monomer, 0.04-0.07 parts of initiator, 0.01-0.03 parts of crosslinking agent, and 35-55 parts of mixing water; wherein the polymeric monomer is a combination of sulfonic acid vinyl monomer and acrylic monomer.

2. The polymer cementitious composite material according to claim 1, characterized in that, The amount of the sulfonic acid-based vinyl monomer accounts for more than 10% of the total amount of the polymeric monomer.

3. The polymer cementitious composite material according to claim 2, characterized in that, The amount of the sulfonic acid-based vinyl monomer accounts for 20%-40% of the total amount of the polymeric monomer.

4. The polymer cementitious composite material according to claim 3, characterized in that, The sulfonic acid vinyl monomers include 2-acrylamide-2-methylpropanesulfonic acid; the acrylic monomers include sodium acrylate.

5. The polymer cementitious composite material according to claim 1, characterized in that, The aggregate gradation includes three gradations: 1.0-2.0mm, 0.50-1.0mm, and 0.08-0.50mm.

6. The polymer cementitious composite material according to claim 1, characterized in that, The initiator includes at least one of ammonium persulfate, benzoyl peroxide, and potassium persulfate.

7. The polymer cementitious composite material according to claim 1, characterized in that, The crosslinking agent includes at least one of N,N'-methylenebisacrylamide, polyethylene glycol diacrylate, polyethylene glycol dimethacrylate, and trimethylolpropane triacrylate.

8. The method for preparing the polymer cementitious composite material according to any one of claims 1-7, characterized in that, Includes the following steps: S1. Sulfonic acid vinyl monomers, acrylic monomers, initiators, and crosslinking agents are mixed with water to form sulfonic acid vinyl monomer solutions, acrylic monomer solutions, initiator solutions, and crosslinking agent solutions; S2. After mixing the cementitious material and aggregate, add the acrylic monomer solution, the sulfonic acid vinyl monomer solution, the initiator solution and the crosslinking agent solution in sequence, and stir to form a slurry; S3. The slurry is shaped and in-situ polymerized during the hydration process to obtain the polymer cement-based composite material.

9. The preparation method according to claim 8, characterized in that, In step S2, the stirring includes stirring at low speed for 1-2 minutes, letting it stand for 20-40 seconds, and then stirring at high speed for 1-2 minutes; wherein the low-speed stirring has a self-speed rate of 130-150 rpm and a common speed rate of 50-70 rpm; the high-speed stirring has a self-speed rate of 270-300 rpm and a common speed rate of 110-140 rpm.

10. The application of the polymer cement-based composite material according to any one of claims 1-7 in the preparation of building structural components, road pavements, and hydraulic engineering components.

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