Polar rubber modified cementitious composite material and method of making

Abstract

This application relates to the field of cement-based material modification, specifically to a polar rubber-modified cement-based composite material and its preparation method. The material comprises: 100-150 parts silicate cement, 200-300 parts fly ash, 4-20 parts polar rubber, 66-150 parts fine aggregate, 70-110 parts water, 2-5 parts polycarboxylate superplasticizer, and 7-10 parts PVA fiber; the fine aggregate includes quartz sand and natural sand; the polar rubber is prepared by vulcanizing a mixture of carboxylated styrene-butadiene rubber and zinc dimethacrylate; the mass ratio of carboxylated styrene-butadiene rubber to zinc dimethacrylate is 100:29-31. The polar rubber in this application effectively delays the microcrack propagation and mechanical property deterioration of the polar rubber-modified cement-based composite material under freeze-thaw conditions through a synergistic mechanism of interfacial hydrophilic modification, reversible energy dissipation from ionic crosslinking, and matrix densification, thereby improving the freeze-thaw resistance of the polar rubber-modified cement-based composite material.

Description

Technical Field

[0001] This application relates to the field of cement-based material modification, specifically to a polar rubber-modified cement-based composite material and its preparation method. Background Technology

[0002] In high-altitude permafrost regions, freeze-thaw cycles are one of the main factors leading to the degradation of the durability of concrete structures. During freeze-thaw cycles, the repeated expansion and contraction of pore water within the concrete generates periodic stress, triggering the propagation of internal microcracks and surface spalling, thereby significantly weakening the mechanical properties and service life of the structure. In recent years, my country has successively constructed major projects in high-altitude permafrost regions, such as the Qinghai-Tibet Railway, the Sichuan-Tibet Railway, and the Harbin-Dalian High-Speed ​​Railway, placing higher demands on the durability of concrete materials under extreme freeze-thaw environments. Engineered cementitious composites (ECC) are highly ductile cement-based materials prepared from cement, fine sand, mineral admixtures, fibers, and additives. Their tensile strain typically exceeds 2%, exhibiting strain hardening, multi-crack cracking, and excellent crack control capabilities. Studies have shown that ECC exhibits superior freeze-thaw resistance compared to ordinary concrete. The mechanism is mainly manifested in the following ways: the uniformly distributed fibers optimize the pore structure of the matrix, making the pores small and evenly distributed; after the microcracks initiate, the fibers play a bridging role, effectively inhibiting the expansion of harmful pores during the freeze-thaw process and constraining the expansion stress generated by the freezing of pore water; at the same time, the material's high tensile ductility, the self-healing properties of microcracks, and the refined mix design synergistically improve its structural integrity and mechanical stability under repeated freeze-thaw conditions from the micro to the macro level. Although ECC has shown significant advantages in freeze-thaw resistance, the durability evolution law under the coupled effects of freeze-thaw cycles and other loads, salt corrosion, and other factors in complex cold environments is still unclear, and the long-term performance of existing ECC material systems under extreme conditions needs further improvement.

[0003] To mitigate the damage to concrete caused by freeze-thaw cycles, researchers have attempted to incorporate rubber materials into concrete and have conducted extensive studies on their performance under freeze-thaw conditions. In existing technologies, waste rubber granules or rubber powder are often used as admixtures, partially replacing cement or aggregates in the concrete matrix. The high elasticity and low thermal conductivity of rubber materials are utilized to absorb expansion stress during freeze-thaw processes and reduce internal temperature gradients. Studies have shown that ordinary rubber, due to its hydrophobic surface, easily traps air into the matrix during concrete mixing, forming interfacial defects. Simultaneously, its inherent physicochemical properties also adversely affect the freeze-thaw resistance of cement-based materials. Summary of the Invention

[0004] To address the problem of interface defects caused by the hydrophobicity of ordinary rubber in cement-based materials, which reduces the freeze-thaw resistance of cement-based materials, this application provides a polar rubber-modified cement-based composite material and its preparation method.

[0005] In a first aspect, this application provides a polar rubber-modified cement-based composite material, which adopts the following technical solution: A polar rubber-modified cement-based composite material, comprising the following components in parts by weight: 100-150 parts silicate cement, 200-300 parts fly ash, 4-20 parts polar rubber, 66-150 parts fine aggregate, 70-110 parts water, 2-5 parts polycarboxylate superplasticizer, and 7-10 parts PVA fiber. The fine aggregate includes any one of quartz sand and natural sand; The polar rubber is prepared by vulcanizing a mixture of carboxylated styrene-butadiene rubber and zinc dimethacrylate. The mass ratio of the carboxylated styrene-butadiene rubber to zinc dimethacrylate is 100:29-31.

[0006] By employing the above-mentioned technical solution, the zinc dimethacrylate-reinforced rubber nanocomposite material possesses a highly complex microstructure, with numerous ion clusters of 10-30 nm in size generated by the in-situ polymerization of zinc dimethacrylate. In the peroxide-initiated rubber / zinc dimethacrylate system, the rubber molecular chains undergo covalent cross-linking to form CC cross-linking bonds. Furthermore, zinc dimethacrylate traps free radicals and introduces a large number of ion pairs. Due to the electrostatic interactions between these ion pairs, they approach each other and accumulate to form multiple ion pairs, which further aggregate to form ion cluster structures. These ion clusters restrict the movement of polymer chain segments and produce a cross-linking effect to reinforce the rubber. Therefore, the network structure in the rubber / zinc dimethacrylate composite material mainly consists of covalent cross-linking and ionic cross-linking. The peroxide-initiated polymerization of zinc dimethacrylate introduces a large number of ion pairs into the rubber matrix. Due to the strong electrostatic interactions between the ion pairs, they aggregate to form multiple ion pairs and further accumulate to form ion cluster structures. The ion clusters, combined with the movement of the rubber chains, act similarly to cross-linking. The polymerization reaction of zinc dimethacrylate introduces a large number of ionic clusters into the rubber matrix, enhancing the polarity and hydrophilicity of the rubber. A polar rubber was prepared by combining carboxylated styrene-butadiene rubber / zinc dimethacrylate and then incorporated into a polar rubber-modified cementitious composite material.

[0007] In this application, polar rubber replaces a portion of the fine aggregate, which includes any one of quartz sand and natural sand. The mechanism by which polar rubber improves the freeze-thaw resistance of polar rubber-modified cementitious composites stems from the synergistic effect of its multiple physicochemical effects. First, the polar groups (such as carboxyl groups) introduced by zinc dimethacrylate endow the rubber with hydrophilicity, enabling it to form good chemical bonds and hydrogen bonds with the cement matrix, significantly reducing the porosity and initial defects in the interfacial transition zone, fundamentally inhibiting the accumulation of free water and the formation of permeation channels. Second, under the ice expansion stress generated by freeze-thaw cycles, the low-modulus rubber particles act as stress buffers through elastic deformation. More importantly, the ionic cross-linked network (ion clusters) formed by the in-situ polymerization of zinc dimethacrylate in the rubber can act as reversible sacrificial bonds, dissipating destructive energy through reversible breakage and rearrangement of electrostatic interactions, thereby protecting the integrity of the rubber matrix and the covalent cross-linked network. In addition, the dense interfacial bonding prolongs the water permeation path, further enhancing the impermeability of the matrix.

[0008] The polar rubber in this application effectively delays the microcrack propagation and mechanical property deterioration of polar rubber-modified cementitious composites in freeze-thaw environments through the synergistic mechanism of interfacial hydrophilic modification, reversible energy dissipation of ionic crosslinking, and matrix densification, thereby improving the freeze-thaw resistance of polar rubber-modified cementitious composites.

[0009] Preferably, the polar rubber further contains modified graphene oxide, nano-silica, zinc stearate, and zinc-based isomer modified zinc oxide; the mass ratio of the carboxylated styrene-butadiene rubber to the modified graphene oxide, nano-silica, zinc stearate, and zinc-based isomer modified zinc oxide is 100:0.4-0.6:1.4-1.6:1.9-2.1:3.9-4.1.

[0010] Preferably, the method for preparing the polar rubber includes the following steps: Reaction: 1000 parts by volume of zinc sulfate solution and 1000 parts by volume of sodium hydroxide solution were mixed and reacted at 70°C for 80 min. After filtration and drying, zinc hydroxide precipitate was obtained. The zinc sulfate solution contained 15 wt.% zinc sulfate, and the sodium hydroxide solution contained 7 wt.% sodium hydroxide. Calcination: Polyethylene glycol is added to zinc hydroxide precipitate, then calcined, cooled and then silane coupling agent KH550 is added to obtain zinc-based isomer modified zinc oxide; Pretreatment: Add graphene oxide to an ethanol aqueous solution and sonicate for 10 min, then add silane coupling agent KH590, mix and sonicate for 8 h, and then vacuum dry to obtain modified graphene oxide. Preparation: Plasticize 100 parts by weight of carboxylated styrene-butadiene rubber for 2 min, add 1.9-2.1 parts by weight of zinc stearate and mix for 2 min, then add 0.4-0.6 parts by weight of modified graphene oxide and disperse, then mix with 29-31 parts by weight of zinc dimethacrylate, 1.4-1.6 parts by weight of nano silica and 3.9-4.1 parts by weight of zinc-based isomer modified zinc oxide, then add 1.5 parts by weight of dicumyl peroxide and vulcanize at 160℃ for 18 min, then pulverize to obtain polar rubber particles.

[0011] Preferably, in the calcination step, the calcination temperature is 575-585℃ and the calcination time is 2.4-2.6h; The mass ratio of zinc hydroxide precipitate to polyethylene glycol is 100:3.9-4.1; the mass percentage of silane coupling agent KH550 in zinc-based isomer modified zinc oxide is 3.9-4.1 wt.%.

[0012] Preferably, in the pretreatment step, the volume ratio of ethanol to water in the ethanol-water solution is 9:0.9-1.1; The graphene oxide is 100 parts by weight, and the ethanol aqueous solution is 950-1050 parts by volume. The mass ratio of graphene oxide to silane coupling agent KH590 is 100:3.9-4.1.

[0013] By employing the above technical solutions, ordinary graphene oxide, due to its easy clustering caused by van der Waals forces between sheets, becomes a stress concentration point during freeze-thaw cycles. Silane hydrolysis products condense with the carboxyl / hydroxyl groups of graphene oxide to form Si-OC bonds, disrupting the aggregated structure, improving dispersion uniformity, and reducing freeze-thaw microcracks. The directional alignment of silane alkyl chains forms a hydrophobic layer, blocking water migration pathways. After the modified graphene oxide surface becomes hydrophobic, its strong adsorption of water molecules is weakened, increasing the interfacial water molecule migration rate and further lowering the freezing point. The silane-modified graphene oxide sheets form a dense barrier network in the cement matrix, reducing water absorption.

[0014] The long silane chains on the surface of modified graphene oxide form an interlaced arrangement with the alkyl chains of zinc stearate, increasing the contact angle and decreasing the water absorption rate. Zinc ions from zinc stearate form ionic bonds with the carboxyl groups of modified graphene oxide, and simultaneously covalently connect with the rubber crosslinking network through the silane organic ends, constructing a three-dimensional interface of "graphene oxide-zinc stearate-rubber." This improves interfacial adhesion strength and reduces freeze-thaw microcracks. Modified graphene oxide regulates the migration rate of water molecules at the interface, while zinc stearate blocks the liquid water replenishment channels, further lowering the freezing point.

[0015] Nano-sized silica particles can fill cement capillary pores, reducing the content of freezeable water and lowering the risk of frost heave. The Si-OH on the surface of nano-silica reacts with calcium hydroxide in the cement to form additional CSH gel, improving matrix density and early strength. Nano-silica forms nanoscale "rivet" structures at the rubber-cement interface, enhancing the bond strength in the interfacial transition zone and inhibiting the propagation of freeze-thaw microcracks.

[0016] Zinc-based isomer-modified zinc oxide, produced via a wet-calcination co-production process, forms spinel-phase three-dimensional isomer clusters. This reduces grain size, increases specific surface area, exposes more active zinc ion sites, enhances reactivity with cement hydration products, generates a dense zincate layer, and reduces microcracks in the interfacial transition zone. The surface of the zinc-based isomer-modified zinc oxide is then coated with silane to form a hydrophobic layer, blocking water penetration pathways. As a vulcanization activator, the zinc-based isomer-modified zinc oxide synergistically accelerates the crosslinking of dicumyl peroxide with zinc stearate, increasing the rubber's elastic modulus and enhancing its ability to buffer against frost heave stress.

[0017] When polar rubber is prepared, adding one or two of the following: modified graphene oxide, nano-silica, zinc stearate, and zinc-based isomer modified zinc oxide, can only have a slight promoting effect. However, only when they are added together can a good promoting effect be achieved.

[0018] Secondly, this application provides a method for preparing a polar rubber-modified cement-based composite material, using the following technical solution: A method for preparing a polar rubber-modified cementitious composite material, comprising the following steps: Dry material preparation: Mix the silicate cement, fly ash, polar rubber and fine aggregate according to the formula, and stir evenly to obtain dry material; Mixing: Add the water and polycarboxylate superplasticizer of the formula to the dry material and stir evenly to obtain a slurry; then add the PVA fiber of the formula to the slurry and stir until the PVA fiber is completely dispersed to obtain a polar rubber modified cement-based composite material.

[0019] In summary, this application has the following beneficial effects: The polar rubber in this application effectively delays the microcrack propagation and mechanical property deterioration of polar rubber-modified cementitious composites in freeze-thaw environments through the synergistic mechanism of interfacial hydrophilic modification, reversible energy dissipation of ionic crosslinking, and matrix densification, thereby improving the freeze-thaw resistance of polar rubber-modified cementitious composites. Detailed Implementation

[0020] The raw materials in this application include the following: Silicate cement: Commercially available products are used; Fine aggregate: Fine aggregate includes any one of quartz sand and natural sand; PVA fiber: Uses commercially available products with CAS number 9002-89-5; Polycarboxylate superplasticizer: Commercially available products are used; Carboxylated styrene-butadiene rubber: using commercially available products with CAS number 25085-39-6; Zinc dimethacrylate: Use commercially available product with CAS number 13189-00-9; Dicumyl peroxide: Use commercially available products with CAS number 80-43-3; Graphene oxide: A commercially available product with CAS number 1034343-98-0 was used; Zinc stearate: Use commercially available product with CAS number 557-05-1; The present application will be further described in detail below with reference to embodiments and comparative examples.

[0021] Example 1 A method for preparing a polar rubber-modified cement-based composite material includes the following steps: Dry material preparation: Mix 1455g silicate cement, 2910g fly ash, 145g polar rubber and 1292g quartz sand, and stir evenly to obtain dry material; Mixing: Mix 1048g of water and 44g of polycarboxylate superplasticizer and slowly add the mixture to the dry material. Stir until homogeneous to obtain a slurry. Then add 83g of PVA fiber to the slurry and stir until the PVA fiber is completely dispersed to obtain a polar rubber modified cement-based composite material.

[0022] The preparation method of the above-mentioned polar rubber includes the following steps: 100g of carboxylated styrene-butadiene rubber was plasticized for 2 minutes, then mixed with 30g of zinc dimethacrylate, and 1.5g of dicumyl peroxide was added. The mixture was then vulcanized at 160℃ for 18 minutes and pulverized to obtain polar rubber particles.

[0023] Example 2-3 Based on the preparation method of Example 1, Examples 2-3 adjust the content of each component of the polar rubber modified cement-based composite material. The specific adjustments are shown in Table 1.

[0024] Performance testing The polar rubber-modified cementitious composite materials of Examples 1-3 were subjected to the following performance tests, and the test results are shown in Table 1.

[0025] 1. Quality loss rate According to GB / T 50082-2024, the mass of polar rubber modified cementitious composite materials before freeze-thaw is determined. m1. Quality after freeze-thaw m 2. Quality loss rate = [( m 1- m 2) / m 1]×100%.

[0026] 2. Rate of change of relative dynamic elastic modulus According to GB / T 50082-2024, the dynamic elastic modulus of polar rubber modified cementitious composites before freeze-thaw is determined. E 0 Dynamic elastic modulus after freeze-thaw E d，n , n The number of freeze-thaw cycles represents the relative dynamic elastic modulus. P =[ E d，n / E 0 ×100%, the rate of change of relative dynamic elastic modulus = ( P- 1)×100%. In this application n It is 200 times.

[0027] Table 1. Content (g) of each component and performance test results of polar rubber modified cementitious composite materials in Examples 1-3.

[0028] Referring to Table 1, it can be seen from the comparison of Examples 1-3 that Example 1 has the lowest mass loss rate and the highest rate of change of relative dynamic elastic modulus, and the polar rubber modified cement-based composite material prepared in Example 1 has the best performance.

[0029] The polar rubber-modified cement-based composite material prepared using the above formulation exhibits good performance. This is because the zinc dimethacrylate-reinforced rubber nanocomposite material possesses a highly complex microstructure, with numerous ion clusters of 10-30 nm in size generated by the in-situ polymerization of zinc dimethacrylate. In the peroxide-initiated rubber / zinc dimethacrylate system, rubber molecular chains undergo covalent cross-linking to form CC cross-links. Furthermore, zinc dimethacrylate traps free radical polymerization and introduces a large number of ion pairs. Due to the electrostatic interactions between these ion pairs, they approach each other and accumulate to form multiple ion pairs, which further aggregate to form ion cluster structures. These ion clusters restrict the movement of polymer chain segments and produce a cross-linking effect to reinforce the rubber. Therefore, the network structure in the rubber / zinc dimethacrylate composite material mainly consists of covalent cross-linking and ionic cross-linking. The peroxide-initiated polymerization of zinc dimethacrylate introduces a large number of ion pairs into the rubber matrix. Due to the strong electrostatic interactions between these ion pairs, they aggregate to form multiple ion pairs and further accumulate to form ion cluster structures. These ion clusters, combined with the movement of the rubber chains, act similarly to cross-linking. The polymerization reaction of zinc dimethacrylate introduces a large number of ionic clusters into the rubber matrix, enhancing the polarity and hydrophilicity of the rubber. A polar rubber was prepared by combining carboxylated styrene-butadiene rubber / zinc dimethacrylate and then incorporated into a polar rubber-modified cementitious composite material.

[0030] In this application, polar rubber replaces a portion of the fine aggregate, which includes any one of quartz sand and natural sand. The mechanism by which polar rubber improves the freeze-thaw resistance of polar rubber-modified cementitious composites stems from the synergistic effect of its multiple physicochemical effects. First, the polar groups (such as carboxyl groups) introduced by zinc dimethacrylate endow the rubber with hydrophilicity, enabling it to form good chemical bonds and hydrogen bonds with the cement matrix, significantly reducing the porosity and initial defects in the interfacial transition zone, fundamentally inhibiting the accumulation of free water and the formation of permeation channels. Second, under the ice expansion stress generated by freeze-thaw cycles, the low-modulus rubber particles act as stress buffers through elastic deformation. More importantly, the ionic cross-linked network (ion clusters) formed by the in-situ polymerization of zinc dimethacrylate in the rubber can act as reversible sacrificial bonds, dissipating destructive energy through reversible breakage and rearrangement of electrostatic interactions, thereby protecting the integrity of the rubber matrix and the covalent cross-linked network. In addition, the dense interfacial bonding prolongs the water permeation path, further enhancing the impermeability of the matrix.

[0031] The negative mass loss rate may be due to a small amount of matrix peeling caused by freeze-thaw heave, but the enhanced hydrophilicity of the polar rubber strengthens the interfacial bonding and reduces peeling; at the same time, the cementitious material continues to hydrate, and the amount of new products exceeds the amount of peeling, thus increasing the total mass.

[0032] Example 4 adjusts the preparation method of polar rubber based on the preparation method of Example 1: 100g of carboxylated styrene-butadiene rubber was plasticized for 2 minutes. 2g of zinc stearate was added and mixed for 2 minutes. Then, 0.5g of modified graphene oxide was added and dispersed. The mixture was then mixed with 30g of zinc dimethacrylate, 1.5g of nano-silica and 4g of zinc-based isomer modified zinc oxide. 1.5g of dicumyl peroxide was added and vulcanized at 160℃ for 18 minutes. After pulverization, polar rubber particles were obtained.

[0033] The preparation method of modified graphene oxide includes the following steps: 100g of graphene oxide was added to 1L of ethanol aqueous solution (ethanol to water volume ratio of 9:1) and sonicated for 10min. Then, 4g of silane coupling agent KH590 was added and sonicated for 8h. Finally, the mixture was vacuum dried to obtain modified graphene oxide.

[0034] A method for preparing zinc-based isomer-modified zinc oxide includes the following steps: Reaction: 1 L of zinc sulfate solution (zinc sulfate mass fraction 15 wt.%) and 1 L of sodium hydroxide solution (sodium hydroxide mass fraction 7 wt.%) were mixed and reacted at 70 °C for 80 min. After filtration and drying, zinc hydroxide precipitate was obtained. Calcination: Polyethylene glycol was added to zinc hydroxide precipitate at a mass ratio of 100:4. The mixture was then calcined at 580°C for 2.5 h. After cooling, silane coupling agent KH550 was added at a mass ratio of 4 wt.% in the zinc-based isomer modified zinc oxide to obtain zinc-based isomer modified zinc oxide.

[0035] Comparative Examples 1-5 Comparative Example 1 modifies the preparation method of polar rubber based on the preparation method of Example 4: 100g of carboxylated styrene-butadiene rubber was plasticized for 2 minutes. 0.5g of modified graphene oxide was added and dispersed, then mixed with 30g of zinc dimethacrylate. 1.5g of dicumyl peroxide was added and vulcanized at 160℃ for 18 minutes. After pulverization, polar rubber particles were obtained.

[0036] Comparative Example 2 adjusts the preparation method of polar rubber based on the preparation method of Example 4: Plasticize 100g of carboxylated styrene-butadiene rubber for 2 minutes, add 2g of zinc stearate and mix for 2 minutes, then mix with 30g of zinc dimethacrylate, add 1.5g of dicumyl peroxide and vulcanize at 160℃ for 18 minutes, then pulverize to obtain polar rubber particles.

[0037] Comparative Example 3 modifies the preparation method of polar rubber based on the preparation method of Example 4: Plasticize 100g of carboxylated styrene-butadiene rubber for 2 minutes, add 2g of zinc stearate and mix for 2 minutes, then add 0.5g of modified graphene oxide for dispersion, then mix with 30g of zinc dimethacrylate, then add 1.5g of dicumyl peroxide and vulcanize at 160℃ for 18 minutes, and then pulverize to obtain polar rubber particles.

[0038] Comparative Example 4 modifies the preparation method of polar rubber based on the preparation method of Example 4: 100g of carboxylated styrene-butadiene rubber was plasticized for 2 minutes, then mixed with 30g of zinc dimethacrylate and 1.5g of nano silica, and then 1.5g of dicumyl peroxide was added and vulcanized at 160℃ for 18 minutes. After pulverization, polar rubber particles were obtained.

[0039] Comparative Example 5 modifies the preparation method of polar rubber based on the preparation method of Example 4: 100g of carboxylated styrene-butadiene rubber was plasticized for 2 minutes, then mixed with 30g of zinc dimethacrylate and 4g of zinc-based isomer modified zinc oxide, and then 1.5g of dicumyl peroxide was added and vulcanized at 160℃ for 18 minutes. After crushing, polar rubber particles were obtained.

[0040] The polar rubber-modified cementitious composite materials of Examples 4 and Comparative Examples 1-5 were subjected to the above performance tests, and the test results are shown in Table 2.

[0041] Table 2 Performance test results for Examples 1, 4 and Comparative Examples 1-5

[0042] Referring to Table 2, comparing Examples 1, 4, and Comparative Examples 1-5, it can be seen that the mass loss rate of Example 4 is lower than that of Example 1, and the relative dynamic elastic modulus change rate is higher than that of Example 1. This indicates that the addition of modified graphene oxide, nano silica, zinc stearate, and zinc-based isomer modified zinc oxide during the preparation of polar rubber, and the mass ratio of carboxylated styrene-butadiene rubber to modified graphene oxide, nano silica, zinc stearate, and zinc-based isomer modified zinc oxide being 100:0.5:1.5:2:4, will produce a good promoting effect.

[0043] Compared with Comparative Examples 1-5, Example 4 showed a lower mass loss rate and a higher rate of change in relative dynamic elastic modulus. This indicates that adding one or two of the following—modified graphene oxide, nano-silica, zinc stearate, and zinc-based isomer-modified zinc oxide—during the preparation of polar rubber only provides a slight promoting effect; however, a good promoting effect is achieved only when all of them are added together.

[0044] This specific embodiment is merely an explanation of this application and is not intended to limit it. After reading this specification, those skilled in the art can make modifications to this embodiment without contributing any inventive step, but such modifications are protected by patent law as long as they fall within the scope of the claims of this application.

Claims

1. A polar rubber-modified cement-based composite material, characterized in that, The components include the following parts by weight: 100-150 parts silicate cement, 200-300 parts fly ash, 4-20 parts polar rubber, 66-150 parts fine aggregate, 70-110 parts water, 2-5 parts polycarboxylate superplasticizer, and 7-10 parts PVA fiber. The fine aggregate includes any one of quartz sand and natural sand; The polar rubber is prepared by vulcanizing a mixture of carboxylated styrene-butadiene rubber and zinc dimethacrylate. The mass ratio of the carboxylated styrene-butadiene rubber to zinc dimethacrylate is 100:29-31.

2. The polar rubber-modified cement-based composite material according to claim 1, characterized in that: The polar rubber also contains modified graphene oxide, nano silica, zinc stearate, and zinc-based isomer modified zinc oxide; the mass ratio of the carboxylated styrene-butadiene rubber to the modified graphene oxide, nano silica, zinc stearate, and zinc-based isomer modified zinc oxide is 100:0.4-0.6:1.4-1.6:1.9-2.1:3.9-4.

1.

3. The polar rubber-modified cement-based composite material according to claim 2, characterized in that: The method for preparing the polar rubber, Includes the following steps: Reaction: 1000 parts by volume of zinc sulfate solution and 1000 parts by volume of sodium hydroxide solution were mixed and reacted at 70°C for 80 min. After filtration and drying, zinc hydroxide precipitate was obtained. The zinc sulfate solution contained 15 wt.% zinc sulfate, and the sodium hydroxide solution contained 7 wt.% sodium hydroxide. Calcination: Polyethylene glycol is added to zinc hydroxide precipitate, then calcined, cooled and then silane coupling agent KH550 is added to obtain zinc-based isomer modified zinc oxide; Pretreatment: Add graphene oxide to an ethanol aqueous solution and sonicate for 10 min, then add silane coupling agent KH590, mix and sonicate for 8 h, and then vacuum dry to obtain modified graphene oxide. Preparation: Plasticize 100 parts by weight of carboxylated styrene-butadiene rubber for 2 min, add 1.9-2.1 parts by weight of zinc stearate and mix for 2 min, then add 0.4-0.6 parts by weight of modified graphene oxide and disperse, then mix with 29-31 parts by weight of zinc dimethacrylate, 1.4-1.6 parts by weight of nano silica and 3.9-4.1 parts by weight of zinc-based isomer modified zinc oxide, then add 1.5 parts by weight of dicumyl peroxide and vulcanize at 160℃ for 18 min, then pulverize to obtain polar rubber particles.

4. The polar rubber-modified cement-based composite material according to claim 3, characterized in that: In the calcination step, the calcination temperature is 575-585℃, and the calcination time is 2.4-2.6h; The mass ratio of zinc hydroxide precipitate to polyethylene glycol is 100:3.9-4.1; the mass percentage of silane coupling agent KH550 in zinc-based isomer modified zinc oxide is 3.9-4.1 wt.%.

5. The polar rubber-modified cement-based composite material according to claim 3, characterized in that: In the pretreatment step, the volume ratio of ethanol to water in the ethanol-water solution is 9:0.9-1.1; The graphene oxide is 100 parts by weight, and the ethanol aqueous solution is 950-1050 parts by volume. The mass ratio of graphene oxide to silane coupling agent KH590 is 100:3.9-4.

1.

6. The method for preparing the polar rubber-modified cement-based composite material according to any one of claims 1-5, characterized in that, Includes the following steps: Dry material preparation: Mix the silicate cement, fly ash, polar rubber and fine aggregate according to the formula, and stir evenly to obtain dry material; Mixing: Add the water and polycarboxylate superplasticizer of the formula to the dry material and stir evenly to obtain a slurry; then add the PVA fiber of the formula to the slurry and stir until the PVA fiber is completely dispersed to obtain a polar rubber modified cement-based composite material.

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