Concrete impervious material and preparation method and application thereof

Abstract

The invention belongs to the technical field of concrete impervious materials, and particularly provides a concrete impervious material and a preparation method and application thereof.The concrete impervious material is prepared from, by weight, 100-130 parts of cement, 25-40 parts of silica fume, 20-25 parts of fly ash, 10-15 parts of PBA composite materials, 7-12 parts of polyurea, 5-10 parts of bentonite, 2-3 parts of silane coupling agents and 1.5-2 parts of water reducing agents; the PBA composite material is of a core-shell structure with modified chitosan as a shell and Zn-Co nanoparticles as a core. The concrete anti-seepage material prepared by the invention has the advantage of good anti-seepage performance.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of concrete impermeable materials, and particularly relates to a concrete impermeable material and a preparation method and application thereof. BACKGROUND

[0002] The durability failure of concrete structures is the primary challenge faced by infrastructure. Among them, chloride ions and structural water penetration lead to service performance degradation and durability failure problems, which have long restricted the safety and service life of engineering structures. Chloride ions or water molecules and other penetrating media penetrate through the pore network of concrete to the surface of steel bars, destroy the passivation film, and trigger electrochemical corrosion. Therefore, developing an impermeable material that can stably solidify chloride ions and other penetrating media for a long time is the core scientific problem and technical key to improving the service life of concrete.

[0003] Technical personnel usually use chemical bonding or physical adsorption methods to improve the impermeability of concrete. For example, chemical bonding uses the aluminate phase in cement and the single-sulfur type of hydrated calcium aluminate sulfate to react with chloride ions to generate Friedel salt, which is a main form of fixing chloride ions through chemical bonding. However, this method has two inherent defects: one is the limited capacity, and the total content of aluminate minerals in cement completely determines the chemical bonding capacity, and there is a clear saturation threshold; the other is environmental instability, Friedel salt is a pH-sensitive compound, when the pore solution pH value of concrete decreases due to carbonation, Friedel salt will decompose, and this process causes the re-release of the fixed chloride ions, forming "secondary permeation".

[0004] Physical adsorption uses materials with high specific surface area or special layered structure, such as layered double hydroxides, zeolites, silica fume, etc., to capture chloride ions through physical adsorption and anion exchange. This method provides some additional chloride ion storage capacity, but still has significant shortcomings: on the one hand, there are many anions in the pore solution of concrete, which have strong competition for interlayer sites, severely inhibiting the selective exchange capacity of chloride ions; secondly, the adsorption of chloride ions is a reversible ion exchange process, and the adsorption strength is limited, when the external environment chloride ion concentration decreases or the pH value changes dramatically, there is a risk of desorption, and permanent fixation cannot be achieved; thirdly, in the complex cement hydration environment, the adsorption structure may dissolve or reconfigure, leading to the decay of ion exchange performance over time.

[0005] Currently, during the whole life cycle of concrete, especially in dynamic environments such as carbonation, wet-dry cycling, sulfate attack, etc., how to achieve high-capacity, high-selectivity, and irreversible stable solidification of chloride ions and other penetrating media is of practical significance and value. SUMMARY

[0006] In order to further improve the impermeability of concrete in complex service environment, the application provides a concrete impermeable material, a preparation method and application thereof.

[0007] The application first provides a concrete impermeable material, which comprises the following raw materials in parts by weight: cement 100-130 parts, microsilica powder 25-40 parts, fly ash 20-25 parts, PBA composite material 10-15 parts, polyurea 7-12 parts, bentonite 5-10 parts, silane coupling agent 2-3 parts, and water reducing agent 1.5-2 parts; the PBA composite material is a core-shell structure with modified chitosan as the shell and Zn-Co nanoparticles as the core.

[0008] Further, the PBA composite material is prepared by the following method: 1) Dissolve cobalt nitrate and zinc nitrate in deionized water to obtain a cobalt-zinc precursor solution, then drop the cobalt-zinc precursor solution into a trisodium citrate solution, and stir to obtain a mixed solution; 2) Drop potassium ferricyanide solution into the mixed solution, stir in an ice water bath for 3-5 h, centrifuge the obtained reaction solution, wash the obtained separation with deionized water and ethanol, then re-disperse in deionized water to obtain a dispersion; 3) Take the dispersion, adjust the pH value to 6.5, then add a chitosan / acetic acid mixed solution dropwise, after the dropwise addition is completed, add EDC and NHS and stir to react, after the reaction is completed, drop calcium chloride solution and 2-aldehyde benzene boronic acid solution, stir overnight, centrifuge and wash the final product, and dry to obtain the product.

[0009] Further, in the step 1), the molar ratio of cobalt nitrate, zinc nitrate and trisodium citrate in the mixed solution is (0.6-0.7):(0.3-0.35):1.

[0010] Further, in the step 2), the molar ratio of potassium ferricyanide to trisodium citrate is 1:(1-1.15).

[0011] Further, in the step 2), the centrifugation is at a speed of 12000-15000 rpm for 10-15 min.

[0012] Further, in the step 3), the mass ratio of chitosan to acetic acid in the chitosan / acetic acid mixed solution is 1:(1-1.5).

[0013] Further, in the step 3), the pH value is adjusted to 6.5 by using an organic base.

[0014] Further, the organic base is a quaternary ammonium base or a quaternary phosphonium base.

[0015] The application further provides a preparation method of the concrete anti-permeation material, which comprises the following steps: uniformly mixing cement, microsilica powder, fly ash, PBA composite material, polyurea, bentonite, silane coupling agent and water reducing agent according to proportions.

[0016] The application further provides an application of the concrete anti-permeation material, which is used in water conservancy facilities and building construction.

[0017] Compared with the prior art, the application has the following beneficial effects: The microsilica powder, fly ash and bentonite are used as inorganic filling components in the application, which can form an anti-permeation plugging system with cement gel materials, and has a good plugging and anti-permeation effect on point-line-surface leakage such as cracks. In addition, the polyurea and PBA composite material are introduced into the system, the polyurea material can further fill the finer micro-nano cracks and inhibit the transmission and diffusion of the permeation medium. In addition, the PBA composite material has a higher capture capacity of chloride ions by using multiple mechanisms such as ion exchange / coordination and electrostatic adsorption, and can resist the displacement of other anions to a certain extent, and has a more stable anti-permeation effect. In addition, the PBA composite material of the application can be bonded with the concrete hydration products to a certain extent, and can be better compatible with the concrete microstructure, auxiliary improve the pore structure, and overall improve the anti-permeation performance of the concrete under complex service environment. BRIEF DESCRIPTION OF DRAWINGS

[0018] Figure 1 The figure is a schematic diagram of the anti-permeation performance test data of the concrete anti-permeation materials of examples 1-2 and control groups 1-2 of the application. DETAILED DESCRIPTION

[0019] The technical solutions in the embodiments of the application will be clearly and completely described below with reference to the drawings in the embodiments of the application. Obviously, the described embodiments are only part of the embodiments of the application, not all the embodiments. Based on the embodiments in the application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the application.

[0020] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the application belongs. The terms used in the specification of the application are only for the purpose of describing the specific embodiments and are not intended to limit the application. The term "and / or" used herein includes any and all combinations of one or more related listed items.

[0021] In the case of using "include", "have", and "contain" described in this document, it is intended to cover non-exclusive inclusion, unless the explicit limiting language such as "only", "consisting of", etc. is used, another component can also be added.

[0022] The words "preferably", "more preferably", "most preferably", "particularly", "more particularly", "particularly preferably", and "most particularly" in the specification are used to describe the embodiments of the application. However, it is to be understood that the words "preferably", "more preferably", "most preferably", "particularly", "more particularly", "particularly preferably", and "most particularly" are not used to limit alternatives that can also be preferred in some circumstances. Furthermore, the use of these words in some areas of the specification is not intended to mean that other embodiments of the application in other areas are not also preferred.

[0023] In this document, "further", "furthermore", "in addition", and the like are used to describe additional features that are not essential to the technical solution of the application, and should not be understood as limiting the scope of protection of the application.

[0024] In this document, "at least one" means one or more, such as one, two, and two or more. The meaning of "a plurality" or "several" is at least two, such as two, three, etc. The meaning of "a plurality of" is at least two, such as two, three, etc., unless otherwise explicitly specified. In the description of the application, the meaning of "several" is at least one, such as one, two, etc., unless otherwise explicitly specified.

[0025] When a numerical range is disclosed herein, the above range is considered to be continuous and includes the minimum and maximum values of the range, as well as every value between the minimum and maximum values. Further, when the range refers to integers, every integer between the minimum and maximum values of the range is included. In addition, when multiple ranges are provided to describe a feature or characteristic, the ranges can be combined. In other words, unless otherwise indicated, all ranges disclosed herein should be understood to include any and all sub-ranges subsumed therein.

[0026] If not otherwise specified, all steps of the present application can be performed in sequence or randomly. For example, the method comprises steps (a) and (b) means that the method can comprise steps (a) and (b) in sequence, or steps (b) and (a) in sequence. For example, the method can further comprise step (c) means that step (c) can be added to the method in any sequence, for example, the method can comprise steps (a), (b) and (c), or steps (a), (c) and (b), or steps (c), (a) and (b), etc. Unless otherwise mentioned, the singular form of the term can include the plural form and cannot be understood as one in number.

[0027] In the present application, "above" or "below" includes the number itself. For example, 1 below includes 1.

[0028] In the present application, room temperature refers to 0-40℃, including but not limited to 10-40℃, or further 20-30℃.

[0029] The present application provides a kind of concrete impermeable material after a large number of experimental research, comprising the following weight parts of raw materials: cement 100-130 parts, microsilica 25-40 parts, fly ash 20-25 parts, PBA composite material 10-15 parts, polyurea 7-12 parts, bentonite 5-10 parts, silane coupling agent 2-3 parts, water reducing agent 1.5-2 parts;The PBA composite material is with modified chitosan as shell, with Zn-Co nanoparticles as core core-shell structure.

[0030] Further, the PBA composite material is prepared by the following method: 1) dissolve cobalt nitrate and zinc nitrate in deionized water to obtain a cobalt-zinc precursor solution, then add the cobalt-zinc precursor solution dropwise into a trisodium citrate solution, and stir to obtain a mixed solution; 2) add potassium ferricyanide solution dropwise into the mixed solution, stir in ice water bath for 3-5h, centrifuge the obtained reaction solution, wash the obtained separation with deionized water and ethanol, then re-disperse in deionized water to obtain a dispersion; 3) take the dispersion, adjust the pH value to 6.5, then add a chitosan / acetic acid mixed solution dropwise, after the dropwise addition is completed, add EDC and NHS and stir to react, after the reaction is completed, add calcium chloride solution and 2-aldehyde benzene boronic acid solution, stir overnight, centrifuge and wash the final product, and dry to obtain.

[0031] Further, in step 1), the molar ratio of cobalt nitrate, zinc nitrate and trisodium citrate in the mixed solution is (0.6-0.7):(0.3-0.35):1.

[0032] Further, in the step 2), the molar ratio of potassium ferricyanide to trisodium citrate is 1:(1-1.15).

[0033] In some embodiments, in the step 2), the molar ratio of potassium ferricyanide to trisodium citrate can be 1:1, 1:1.05, 1:1.1, 1:1.15, 1:1.2, 1:1.25, 1:1.3, 1:1.35, 1:1.4, 1:1.45, 1:1.5. In general, in the step 2), the molar ratio of potassium ferricyanide to trisodium citrate is 1:1, 1:1.05, which can achieve better experimental results.

[0034] Further, in the step 2), the centrifugation is at a speed of 12000-15000 rpm for 10-15 min.

[0035] Further, in the step 3), the mass ratio of chitosan to acetic acid in the chitosan / acetic acid mixed solution is 1:(1-1.5).

[0036] In some embodiments, in the step 3), the mass ratio of chitosan to acetic acid in the chitosan / acetic acid mixed solution can be 1:1, 1:1.15, 1:1.2, 1:1.25, 1:1.3, 1:1.35, 1:1.4, 1:1.45, 1:15. In general, in the step 3), the mass ratio of chitosan to acetic acid in the chitosan / acetic acid mixed solution is 1:1.2, 1:1.25, which can achieve better experimental results.

[0037] Further, in the step 3), the pH value is adjusted to 6.5 by using an organic base.

[0038] Further, the organic base is a quaternary ammonium base or a quaternary phosphorus base.

[0039] More preferably, the quaternary ammonium base is selected from tetrabutylammonium hydroxide. The quaternary phosphorus base is selected from tetrabutylphosphonium hydroxide.

[0040] The application also provides a preparation method of a concrete impermeable material, comprising the following steps: uniformly mixing cement, microsilica powder, fly ash, PBA composite material, polyurea, bentonite, silane coupling agent, and water reducing agent in a proportion to obtain the concrete impermeable material.

[0041] The application also provides an application of the concrete impermeable material, which is used in water conservancy facilities and building construction.

[0042] The application will be further described below by examples, but the scope of the application is not limited by the examples.

[0043] When the embodiments give numerical ranges, it is understood that unless the application specifically states to the contrary, the two endpoints of each numerical range and any number between the two endpoints are optional. Unless otherwise defined, all technical and scientific terms used in the application have the same meaning as commonly understood by one of ordinary skill in the art. Unless specific conditions are indicated in the embodiments, the procedures are carried out under conventional conditions or manufacturer's recommended conditions. Unless the manufacturer is specified, all reagents or instruments are conventional products that can be purchased on the market. In addition to the specific methods, devices, materials used in the embodiments, any method, device and material of the prior art similar or equivalent to the methods, devices and materials described in the embodiments of the application can also be used to implement the application according to the mastery of the prior art by those skilled in the art and the description of the application.

[0044] Embodiment 1 The concrete impermeable material of the embodiment comprises the following raw materials by weight: cement 12 kg, microsilica 3.5 kg, fly ash 2 kg, PBA composite material 1.25 kg, polyurea 0.85 kg, bentonite 0.75 kg, silane coupling agent 250 g, water reducing agent 100 g.

[0045] The cement is ordinary portland cement with a label of 42.5. The microsilica is low-expansion microsilica. The fly ash is first-grade fly ash. The bentonite is sodium-based bentonite. The silane coupling agent is KH550. The water reducing agent is polycarboxylic acid high-efficiency water reducing agent.

[0046] The PBA composite material of the embodiment is prepared by the following method: 1) Dissolve 8.73 g of cobalt nitrate and 2.38 g of zinc nitrate in 500 mL of deionized water to obtain a cobalt-zinc precursor solution; take 8.23 g of potassium ferricyanide and dissolve it in 500 mL of deionized water to prepare a potassium ferricyanide solution; weigh 7.35 g of sodium citrate dihydrate and dissolve it in 200 mL of deionized water to prepare a trisodium citrate solution; then slowly add the cobalt-zinc precursor solution to the trisodium citrate solution, and stir to obtain a mixed solution; 2) Slowly add the potassium ferricyanide solution to the mixed solution, and stir vigorously in an ice water bath for 5 h, then age at room temperature overnight, centrifuge the resulting reaction solution at 12000 rpm for 15 min, wash the resulting separation with deionized water and ethanol, then re-disperse it in 500 mL of deionized water to obtain a dispersion; 3) Take the dispersion liquid, adjust the pH value to 6.5 with tetrabutylammonium hydroxide, keep in a water bath at 60℃, then add dropwise 500mL of 5wt% chitosan / acetic acid mixed solution, the mass ratio of chitosan to acetic acid in the chitosan / acetic acid mixed solution is 1:1.25, after dropwise addition, add 0.192g of EDC and 0.288g of NHS and stir to react, after the reaction is completed, add dropwise 100mL of 0.5mol / L calcium chloride solution and 30mL of 0.15mol / L 2-aldehyde benzene boronic acid solution, stir overnight, centrifuge and wash the final product, and dry to obtain.

[0047] The preparation method of the concrete impermeable material of the embodiment comprises the following steps: placing cement, microsilica powder, fly ash, PBA composite material, polyurea, bentonite, silane coupling agent and water reducing agent in a high-speed mixer in the above proportions and mixing uniformly to obtain the product.

[0048] Example 2 The concrete impermeable material of the embodiment comprises the following raw materials by weight: cement 12kg, microsilica powder 3.5kg, fly ash 2kg, PBA composite material 1.25kg, polyurea 0.85kg, bentonite 0.75kg, silane coupling agent 250g and water reducing agent 100g.

[0049] The cement is ordinary portland cement with a label of 42.5. The microsilica powder is low-expansion microsilica powder. The fly ash is first-grade fly ash. The bentonite is sodium-based bentonite. The silane coupling agent is KH550. The water reducing agent is polycarboxylic acid high-efficiency water reducing agent.

[0050] The PBA composite material of the embodiment is prepared by the following method: 1) Dissolve 8.73g of cobalt nitrate and 2.38g of zinc nitrate in 500mL of deionized water to obtain a cobalt-zinc precursor solution; dissolve 8.23g of potassium ferricyanide in 500mL of deionized water to prepare a potassium ferricyanide solution; weigh 7.35g of sodium citrate dihydrate and dissolve it in 200mL of deionized water to prepare a trisodium citrate solution; then slowly add the cobalt-zinc precursor solution to the trisodium citrate solution, and stir to obtain a mixed solution; 2) Slowly add the potassium ferricyanide solution to the mixed solution, and stir vigorously in an ice water bath for 5h, then age at room temperature overnight, centrifuge the obtained reaction liquid at a speed of 12000rpm for 15min, wash the obtained separation with deionized water and ethanol, then re-disperse it in 500mL of deionized water to obtain a dispersion liquid; 3) Take the dispersion liquid, adjust the pH value to 6.5 with tetrabutylphosphonium hydroxide, keep in 60℃ water bath, then add dropwise 500mL 5wt% chitosan / acetic acid mixed solution, the mass ratio of chitosan to acetic acid in the chitosan / acetic acid mixed solution is 1:1.25, after dropwise addition, add 0.192g EDC and 0.288g NHS, stir and react, after the reaction is completed, add dropwise 200mL 0.5mol / L calcium chloride solution and 50mL 0.15mol / L 2-aldehyde benzene boronic acid solution, stir overnight, centrifugal wash and dry the final product.

[0051] The preparation method of the concrete impermeable material of the embodiment comprises the following steps: placing cement, microsilica powder, fly ash, PBA composite material, polyurea, bentonite, silane coupling agent and water reducing agent in a high-speed mixer according to the above proportions and mixing uniformly to obtain the concrete impermeable material.

[0052] Control group 1 The concrete impermeable material of the control group comprises the following raw materials by weight: cement 12kg, microsilica powder 3.5kg, fly ash 2kg, polyurea 0.85kg, bentonite 0.75kg, silane coupling agent 250g and water reducing agent 100g.

[0053] The cement is ordinary Portland cement with a label of 42.5. The microsilica powder is low-expansion microsilica powder. The fly ash is first-grade fly ash. The bentonite is sodium-based bentonite. The silane coupling agent is KH550. The water reducing agent is a polycarboxylic acid high-efficiency water reducing agent.

[0054] The preparation method of the concrete impermeable material of the control group comprises the following steps: placing cement, microsilica powder, fly ash, polyurea, bentonite, silane coupling agent and water reducing agent in a high-speed mixer according to the above proportions and mixing uniformly to obtain the concrete impermeable material.

[0055] Control group 2 The concrete impermeable material of the control group comprises the following raw materials by weight: cement 12kg, microsilica powder 3.5kg, fly ash 2kg, PBA composite material 1.25kg, polyurea 0.85kg, bentonite 0.75kg, silane coupling agent 250g and water reducing agent 100g.

[0056] The cement is ordinary Portland cement with a label of 42.5. The microsilica powder is low-expansion microsilica powder. The fly ash is first-grade fly ash. The bentonite is sodium-based bentonite. The silane coupling agent is KH550. The water reducing agent is a polycarboxylic acid high-efficiency water reducing agent.

[0057] The PBA composite material of the control group is prepared by the following method: 1) 8.73 g of cobalt nitrate and 2.38 g of zinc nitrate were dissolved in 500 mL of deionized water to obtain a cobalt-zinc precursor solution; 8.23 g of potassium ferricyanide was dissolved in 500 mL of deionized water to obtain a potassium ferricyanide solution; 7.35 g of sodium citrate dihydrate was dissolved in 200 mL of deionized water to obtain a trisodium citrate solution; then the cobalt-zinc precursor solution was slowly added to the trisodium citrate solution, and stirring was performed to obtain a mixed solution; 2) The potassium ferricyanide solution was slowly added to the mixed solution, and the reaction was performed under vigorous stirring in an ice water bath for 5 h, and then the reaction liquid was aged at room temperature overnight; the obtained reaction liquid was centrifuged at a speed of 12000 rpm for 15 min, and the obtained separation was washed with deionized water and ethanol, and dried to obtain the product.

[0058] The preparation method of the concrete impermeable material of the control group comprises the following steps: the cement, the microsilica powder, the fly ash, the PBA composite material, the polyurea, the bentonite, the silane coupling agent and the water reducing agent are placed in a high-speed mixer and uniformly mixed to obtain the product.

[0059] Performance detection The concrete impermeable material, the coarse aggregate and the fine aggregate of Example 1-2 and Control Group 1-2 were mixed and stirred for 5 min, then water was added and mixed for 5 min, then poured into a mold, vibrated and compacted, demolded after 24 h, and cured in a standard curing room (temperature 20±2℃, RH>90%) for 28 d; after curing, the sample was obtained for standby use. The components and mixing parameters of the sample are as follows: the fine aggregate is natural sand, the coarse aggregate is 5-15 mm gravel, the water-binder ratio is 0.4, the gel material content is 530 kg / m 3 , the fine aggregate content is 600 kg / m 3 , and the amount of coarse aggregate is 900 kg / m 3 .

[0060] The above sample was taken, and the electric flux method in GB / T 50082-2024 “Standard for Testing Methods for Long-term Performance and Durability of Concrete” was used to test the resistance of the concrete to chloride ion penetration by using an external electric field to accelerate the diffusion of chloride ions. The test block cured for 28 d was saturated by using a vacuum water saturation machine, so that the test piece reached a saturated state. After the test piece was vacuum saturated, a Nielde PEU type intelligent electric flux tester was used to detect the electric flux of the test block for 6 h. The test block was placed in an electrolytic tank, and the tank body was filled with prepared NaCl and NaOH solutions at both ends. A high-precision direct current power supply was used to apply a voltage of 60 V to establish a stable electric field gradient, and the electric flux at different times was recorded in real time. The test results are shown in Figure 1 .

[0061] Analysis Figure 1It can be seen that the concrete anti-permeation material has good anti-permeation performance, especially has better anti-permeation effect on chloride ions, and the electric flux under the same time is lower, which indicates that the anti-chloride ion permeation performance is better.

[0062] Although the present application has been described in detail with reference to the foregoing embodiments, technical solutions recorded in the foregoing embodiments can be modified or some technical features can be replaced by equivalent ones by those skilled in the art, and any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A concrete impermeable material, characterized by: The raw materials include the following parts by weight: 100-130 parts cement, 25-40 parts silica fume, 20-25 parts fly ash, 10-15 parts PBA composite material, 7-12 parts polyurea, 5-10 parts bentonite, 2-3 parts silane coupling agent, and 1.5-2 parts water-reducing agent; the PBA composite material is a core-shell structure with modified chitosan as the shell and Zn-Co nanoparticles as the core.

2. The concrete impermeable material of claim 1, wherein: The PBA composite material was prepared by the following method: 1) Dissolve cobalt nitrate and zinc nitrate in deionized water to obtain a cobalt-zinc precursor solution. Then, add the cobalt-zinc precursor solution dropwise to a trisodium citrate solution and stir to obtain a mixed solution. 2) Add potassium ferricyanide solution dropwise to the mixture, stir the reaction in an ice-water bath for 3-5 hours, centrifuge the resulting reaction solution, wash the separated product with deionized water and ethanol, and then redisperse it in deionized water to obtain a dispersion. 3) Take the dispersion, adjust the pH to 6.5, and then add chitosan / acetic acid mixed solution dropwise. After the addition is complete, add EDC and NHS and stir to react. After the reaction is complete, add calcium chloride solution and 2-aldehyde phenylboronic acid solution dropwise, stir overnight, centrifuge, wash and dry the final product.

3. The concrete impermeable material of claim 1, wherein: In step 1), the molar ratio of cobalt nitrate, zinc nitrate, and trisodium citrate in the mixture is (0.6-0.7):(0.3-0.35):

1.

4. The concrete impermeable material of claim 1, wherein: In step 2), the molar ratio of potassium ferricyanide to trisodium citrate is 1:(1-1.15).

5. The concrete impermeable material of claim 1, wherein: In step 2), centrifugation is performed at a speed of 12000-15000 rpm for 10-15 minutes.

6. The concrete impermeable material according to claim 1, characterized in that: In step 3), the mass ratio of chitosan to acetic acid in the chitosan / acetic acid mixed solution is 1:(1-1.5).

7. The concrete impermeable material according to claim 1, characterized in that: In step 3), adjusting the pH value to 6.5 is done using an organic base.

8. The concrete impermeable material according to claim 7, characterized in that: The organic base is a quaternary ammonium base or a quaternary phosphorus base.

9. A method for preparing a concrete impermeable material as described in claim 1, characterized in that: The process includes the following steps: mixing cement, silica fume, fly ash, PBA composite material, polyurea, bentonite, silane coupling agent, and water-reducing agent evenly in proportion.

10. An application of a concrete impermeable material, characterized in that: The concrete impermeable material according to any one of claims 1-8 is used in water conservancy facilities and building construction.

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