An anti-corrosion mass marine concrete and its preparation method

Abstract

The present invention relates to a corrosion-resistant mass marine concrete and a preparation method thereof. By mass fraction, the mass marine concrete comprises the following components: 250-375 parts of cement, 25-100 parts of fly ash, 20-40 parts of recycled fine powder, 1-40 parts of modified weak basic anion resin, 750-900 parts of manufactured sand, 900-1000 parts of ordinary crushed stone, 150-200 parts of water, and 5-20 parts of water reducing agent. Compared with the prior art, the mass marine concrete prepared by the present invention has the advantages of better corrosion resistance, longer service life, and not being prone to cracking, etc.

Description

Technical Field

[0001] The present invention relates to the technical field of building materials, and particularly to a corrosion-resistant mass marine concrete and a preparation method thereof. Background Art

[0002] With the construction of more and more large-scale marine projects such as cross-sea bridges, the demand for mass marine concrete in engineering is increasing, and the performance requirements for the corresponding mass marine concrete are also getting higher and higher. Mass marine concrete is one of the most important civil engineering materials in modern times. It is an artificial stone prepared by mixing cementitious materials, granular aggregates, water, and, if necessary, admixtures and mineral admixtures in a certain proportion, followed by uniform mixing, dense forming, and curing and hardening.

[0003] When mass marine concrete is applied to coastal area construction, chloride ions in the soil or seawater will corrode the mass marine concrete, penetrate to the surface of the steel bars, reduce the pH value on the surface of the steel bars, and damage the passivation film on the surface of the steel bars, thereby accelerating the corrosion of the steel bars. This not only affects the bonding performance between the mass marine concrete and the steel bars, but also accelerates the appearance of cracks in the mass marine concrete under the action of loads, reducing the effective load-bearing area of the reinforced concrete. In addition, there are other types of trace corrosion ions in seawater that can cause corrosion damage to the mass marine concrete. For example, sulfate ions penetrate into the mass marine concrete from the outside and react with certain components of the mass marine concrete to cause corrosion to the mass marine concrete, gradually degrading the performance of the mass marine concrete. At present, in order to improve the corrosion resistance of mass marine concrete, substances such as fly ash, air-entraining agents, and expansion agents are usually incorporated into the concrete to change the internal structure of the mass marine concrete, thereby enhancing the anti-corrosion performance of the mass marine concrete. However, as the service time of the mass marine concrete extends, chloride ions will continuously migrate into the interior of the mass marine concrete, and the anti-corrosion effect decreases rapidly.

[0004] Due to its large volume, high hydration heat, and complex construction conditions, mass marine concrete is prone to cracking, which affects the safety and durability of the structure. When cracks appear in the mass marine concrete, the impact on the performance of the mass marine concrete is greater. Cracks are likely to occur during the operation of mass marine concrete. The main reason is the influence of cement hydration heat. During the hydration process of cement, a large amount of heat is released. Due to the large volume of the mass marine concrete structure, the heat inside the mass marine concrete is not easily dissipated, resulting in a rapid increase in the internal temperature. The surface of the mass marine concrete dissipates heat relatively quickly, thus forming a large temperature difference between the inside and the outside. This temperature difference will generate temperature stress. When the temperature stress exceeds the tensile strength of the concrete, cracks will be caused.

[0005] Patent Publication No. CN114751683A discloses a geopolymer material capable of restoring chloride curing ability, its preparation method and application. By mass percentage, the geopolymer material comprises the following components: fly ash 8 - 11%; slag 33 - 40%; metakaolin 5 - 8%; silica fume 5 - 8%; quartz sand 11 - 13%; composite alkali activator 15 - 17%; water 10 - 11%; anion exchange resin 1.4 - 1.8%. The anion exchange resin is obtained by pretreating D201 macroporous strong-base anion exchange resin through alkali solution immersion and grinding, and its particle size is 200 - 250 mesh. However, the addition of D201 macroporous strong-base anion exchange resin will further enhance the internal alkaline environment, which will reduce the resistance to sulfate ion corrosion to a certain extent. Moreover, after the geopolymer material is discarded, it releases more alkaline substances, with a relatively high pollution risk to the environment such as soil and water bodies. In addition, due to its complex production process and high cost, compared with ordinary geopolymer materials, the unit cost of D201 macroporous strong-base anion exchange resin is relatively high, which will significantly increase the production cost when applied to the preparation of geopolymer materials. Summary of the Invention

[0006] The object of the present invention is to overcome the defects of the above-mentioned existing technologies and provide an anti-corrosion mass marine concrete with better anti-corrosion performance, longer service life and less prone to cracks, and its preparation method.

[0007] The object of the present invention can be achieved by the following technical solutions:

[0008] On the one hand, the present invention provides an anti-corrosion mass marine concrete. By mass parts, the mass marine concrete comprises the following components: 250 - 375 parts of cement, 25 - 100 parts of fly ash, 20 - 40 parts of recycled fine powder, 1 - 40 parts of modified weak-base anion resin, 750 - 900 parts of manufactured sand, 900 - 1000 parts of ordinary crushed stone, 150 - 200 parts of water, and 5 - 20 parts of water reducer.

[0009] Furthermore, the mass parts of the modified weak-base anion resin are preferably 5 - 40 parts, more preferably 5 - 30 parts, and further preferably 15 - 30 parts.

[0010] Furthermore, the weak-base anion resin used is a weak-base acrylic acid-based anion resin, with a particle size of 0 - 2.56 mm and not including 0.

[0011] Even further, the weak-base anion resin used is D315 weak-base acrylic acid-based anion resin.

[0012] Further, the weakly basic anion resin used is modified before use, and the modification process is as follows: The weakly basic anion resin is soaked in a barium ion-containing solution, and after soaking, the modified weakly basic anion resin is obtained.

[0013] Furthermore, the barium ion-containing solution includes barium nitrate solution, barium carbonate solution, barium hydroxide solution, barium peroxide solution, barium chromate solution, and barium manganate solution, which are other types of barium salts that can be ionized in water except for barium sulfate and barium chloride;

[0014] The mass concentration of the barium ion-containing solution is 20%-80%.

[0015] Furthermore, the soaking time is 2-4 h, and when soaking, the barium ion-containing solution submerges the weakly basic anion resin.

[0016] Furthermore, after soaking, the modified weakly basic anion resin is air-dried until the surface is dry.

[0017] Further, the regenerated micro-powder contains 45%-50% calcium oxide, 34%-40% silicon dioxide, 5%-10% aluminum oxide, 2%-5% iron oxide, and the fineness is 40-50 μm.

[0018] Further, the fly ash is Class II fly ash.

[0019] Further, the manufactured sand is medium-coarse sand, and its fineness modulus is between 2.1 and 3.0.

[0020] Further, the particle size range of the ordinary crushed stone is 5-31.5 mm.

[0021] Further, the cement is PO42.5 ordinary Portland cement.

[0022] Further, the water reducing agent is a polycarboxylate water reducing agent.

[0023] On the other hand, the present invention also provides a preparation method for anti-corrosion mass marine concrete, including the following steps:

[0024] S1. Weigh and reserve cement, fly ash, regenerated micro-powder, modified weakly basic anion resin, manufactured sand, ordinary crushed stone, water, and water reducing agent;

[0025] S2. Stir and mix the weighed cement, fly ash, regenerated micro-powder, modified weakly basic anion resin, manufactured sand, ordinary crushed stone, and water reducing agent, and then add water and stir and mix evenly to obtain anti-corrosion mass marine concrete.

[0026] Further, in step S2, first mix ordinary crushed stones and manufactured sand, then add cement, fly ash, recycled fine powder, and modified weakly basic anion resin and mix and stir them, and then add a water reducer and water and mix and stir them.

[0027] Compared with the prior art, the present invention has the following advantages:

[0028] (1) The present invention modifies the weakly basic anion resin with barium salt. On the one hand, it effectively utilizes the adsorption characteristics of the weakly basic anion resin for sulfate ions, adsorbs sulfate ions onto the resin to chemically react and solidify with barium ions, reducing the number of invading sulfate ions; on the other hand, it uses the precipitate produced by the chemical reaction of sulfate ions and barium ions to block the internal pores of the concrete, optimize the compactness of the concrete, and reduce the further invasion and corrosion of sulfate ions and chloride ions into the concrete.

[0029] (2) As is well known, C 3 A (tricalcium aluminate, 3CaO·Al 2 O 3 , abbreviated as C 3 A) has the fastest hydration rate, the fastest heat release rate and the largest heat release amount, and is the largest source of hydration heat of mass marine concrete. The present invention utilizes recycled fine powder, and the calcium ions in the recycled fine powder can react with the sulfate ions invading into the concrete together with the C 3 A generated by cement hydration to form a small amount of AF t (ettringite, 3CaO·Al 2 O 3 ·3CaSO 4 ·32H 2 O, abbreviated as AF t ). C 3 A will further react with the generated AF t to form AF m (monosulfate calcium aluminate, 3CaO·Al 2 O 3 ·CaSO 4 ·31H 2 O, abbreviated as AF m ), forming a diffusion barrier layer on the surface of C 3 A particles to slow down its hydration reaction. The present invention can effectively reduce the hydration heat release of mass marine concrete through recycled fine powder and modified weakly basic anion resin, and further reduce the possibility of the concrete generating temperature cracks.

[0030] (3) In the present invention, the modified weakly basic anion resin can also effectively utilize barium sulfate precipitation to solidify and adhere chloride ions on the resin surface, reduce or even prevent the erosion of chloride ions on the internal concrete, and improve the chloride ion erosion resistance of the concrete. In addition, the weakly basic environment is not conducive to the reaction of corrosive media such as sulfates with the components in the concrete, which can improve the ability of the concrete to resist sulfate erosion to a certain extent, extend the service life of the concrete in a sulfate environment. When the modified weakly basic anion resin is added to the concrete, it will not effectively increase the pH in the concrete, so it can effectively avoid the increase of the internal alkaline environment of the concrete caused by strongly basic resins and reduce the corrosion resistance to sulfate ions.

[0031] (4) During the use of the modified weakly basic anion resin, due to its relatively weak alkalinity, the impact on the environment is relatively small. After the concrete is discarded, the alkaline substances released are less, and the pollution risk to the environment such as soil and water bodies is relatively low, meeting the requirements of modern engineering construction for environmental protection.

[0032] (5) The production process of the weakly basic anion resin is relatively simple, and the prices of its raw materials are relatively low. When it is applied to concrete, the overall performance of the concrete can be improved at a relatively low price, which will not significantly increase the raw material cost, and can achieve better corrosion resistance, longer service life, and less prone to cracks in the concrete. Specific Embodiments

[0033] The present invention will be described in detail below in conjunction with specific embodiments. These embodiments are implemented on the premise of the technical solution of the present invention, and detailed implementation manners and specific operation processes are given. However, the protection scope of the present invention is not limited to the following embodiments. Based on the given embodiments, all other embodiments obtained by those of ordinary skill in the art without creative efforts fall within the protection scope of this application.

[0034] Unless otherwise specified, the reagents, methods, instruments and equipment used in the present invention are conventional reagents, methods, instruments and equipment in the art.

[0035] Example 1

[0036] A C30 corrosion-resistant mass marine concrete, by mass, the mass marine concrete includes 240 parts of cement, 60 parts of fly ash, 30 parts of recycled fine powder, 20 parts of modified weakly basic anion resin, 800 parts of manufactured sand, 950 parts of ordinary crushed stone, 200 parts of water, and 5 parts of water reducing agent.

[0037] In this example, the weakly basic anion resin used is a weakly basic acrylic anion resin with a particle size of 0 - 2.56 mm and not including 0. The weakly basic anion resin used is D315 weakly basic acrylic anion resin, and the manufacturer is Anhui Sanxing Resin Technology Co., Ltd.

[0038] In this embodiment, the weakly basic anion resin used is subjected to a modification treatment before use. The process of the modification treatment is as follows: The weakly basic anion resin is completely immersed in a barium nitrate solution with a mass concentration of 20% for 3 hours. After soaking, it is air-dried until the surface is dry to obtain the modified weakly basic anion resin.

[0039] In this embodiment, the regenerated fine powder contains 45%-50% calcium oxide, 34%-40% silicon dioxide, 5%-10% aluminum oxide, 2%-5% iron oxide, and has a fineness of 40-50 μm.

[0040] In this embodiment, the fly ash is Class II fly ash.

[0041] In this embodiment, the manufactured sand is medium-coarse sand, and its fineness modulus is between 2.1 and 3.0.

[0042] In this embodiment, the particle size range of the ordinary crushed stone is 5-31.5 mm.

[0043] In this embodiment, the cement is PO42.5 ordinary Portland cement.

[0044] In this embodiment, the water reducer is a polycarboxylate water reducer, with a water reduction rate ≥ 25%, a solid content > 15%, a pH = 7.1, and it is sourced from China State Construction Western Construction New Materials Technology Co., Ltd.

[0045] A preparation method of C30 corrosion-resistant mass marine concrete includes the following steps:

[0046] S1. Weigh and reserve cement, fly ash, regenerated fine powder, modified weakly basic anion resin, manufactured sand, ordinary crushed stone, water, and water reducer.

[0047] S2. First, place the ordinary crushed stone and manufactured sand in a mixer, then add cement, fly ash, regenerated fine powder, and weakly basic anion resin and mix and stir for 30 s. Finally, add the water reducer and water, and mix and stir evenly to obtain C30 fly ash ordinary concrete.

[0048] Example 2

[0049] A C30 corrosion-resistant mass marine concrete, compared with Example 1, except that when the used weakly basic anion resin is subjected to the modification treatment, the mass concentration of the barium nitrate solution is adjusted to 40%, and the others are the same.

[0050] Example 3

[0051] A C30 anti-corrosion mass marine concrete, compared with Example 1, except that when the weak basic anion resin used is subjected to modification treatment, the mass concentration of the barium nitrate solution is adjusted to 60%, and the others are the same.

[0052] Example 4

[0053] A C30 anti-corrosion mass marine concrete, compared with Example 1, except that when the weak basic anion resin used is subjected to modification treatment, the mass concentration of the barium nitrate solution is adjusted to 80%, and the others are the same.

[0054] Example 5

[0055] A C30 anti-corrosion mass marine concrete, compared with Example 3, except that the mass fraction of the modified weak basic anion resin is adjusted to 30 parts, and the others are the same.

[0056] Example 6

[0057] A C30 anti-corrosion mass marine concrete, compared with Example 3, except that the mass fraction of the modified weak basic anion resin is adjusted to 25 parts, and the others are the same.

[0058] Example 7

[0059] A C30 anti-corrosion mass marine concrete, compared with Example 3, except that the mass fraction of the modified weak basic anion resin is adjusted to 15 parts, and the others are the same.

[0060] Example 8

[0061] A C30 anti-corrosion mass marine concrete, compared with Example 3, except that the mass fraction of the modified weak basic anion resin is adjusted to 10 parts, and the others are the same.

[0062] Example 9

[0063] A C30 anti-corrosion mass marine concrete, compared with Example 3, except that the mass fraction of the modified weak basic anion resin is adjusted to 5 parts, and the others are the same.

[0064] Comparative Example 1

[0065] A fly ash ordinary concrete, compared with Example 1, except that no recycled fine powder and modified weak basic anion resin are added, and the others are the same.

[0066] The preparation method of the fly ash ordinary concrete is as follows: each component is prepared according to mass. First, the ordinary crushed stone and manufactured sand are placed in a mixer, then cement and fly ash are added and mixed and stirred for 30 s, and finally a water reducing agent and water are added, and after mixing and stirring evenly, C30 fly ash ordinary concrete is obtained.

[0067] Comparative Example 2

[0068] A C30 anti-corrosion mass marine concrete, compared with Example 6, except that the modified weakly basic anion resin is adjusted to a weakly basic anion resin and it is not soaked in a barium ion-containing solution, the others are the same.

[0069] Comparative Example 3

[0070] A C30 anti-corrosion mass marine concrete, compared with Example 3, except that the modified weakly basic anion resin is adjusted to a weakly basic anion resin and it is not soaked in a barium ion-containing solution, the others are the same.

[0071] Comparative Example 4

[0072] A C30 anti-corrosion mass marine concrete, compared with Example 7, except that the modified weakly basic anion resin is adjusted to a weakly basic anion resin and it is not soaked in a barium ion-containing solution, the others are the same.

[0073] Comparative Example 5

[0074] A C30 anti-corrosion mass marine concrete, compared with Example 3, except that the D315 weakly basic acrylic acid-based anion resin is adjusted to a D201 strongly basic anion resin, the others are the same.

[0075] Comparative Example 6

[0076] Compared with Example 3, except that recycled fine powder is not added, the others are the same.

[0077] Comparative Example 7

[0078] Compared with Example 3, except that the modified weakly basic anion resin is not added, the others are the same.

[0079] Comparative Example 8

[0080] Compared with Example 3, except that the barium nitrate solution is adjusted to a calcium nitrate solution, the others are the same.

[0081] The different raw material compositions and dosages of each example and comparative example are shown in Table 1 below.

[0082] Table 1 Different raw material compositions and dosages of each example and comparative example

[0083]

[0084] The performance characterization results of the concrete prepared by each example and comparative example are shown in Table 2.

[0085] Test the compressive strength of 100 mm cube according to the Standard for Test Methods of Physical and Mechanical Properties of Concrete (CBT50081-2019).

[0086] According to the "Standard Test Method for Long-Term Performance and Durability of Ordinary Concrete" (CB / T 50082-2009), the rapid chloride ion diffusion coefficient DRCM and the electrical flux of the concrete are tested.

[0087] According to the immersion corrosion resistance test method (Method K) in the "Test Method for Resistance of Cement to Sulfate Attack" (GB / T1749-2008), the specimens are immersed in fresh water and SO 4 2- solutions (SO 4 2- with a concentration of 20000 mg / L respectively, and an erosion simulation test is carried out for 12 months). After the immersion is completed, the flexural strength of the specimens is measured, and the corrosion resistance coefficient is calculated. Taking the corrosion resistance coefficient ≥ 0.80 as the qualified standard for corrosion resistance and as the judgment criterion.

[0088] According to the "Standard Test Method for Physical and Mechanical Properties of Concrete" (CBT50081-2019). The adiabatic temperature peak of the concrete is measured by a concrete adiabatic temperature rise measuring instrument.

[0089] Table 2 Performance characterization results of the concrete prepared in each example and comparative example

[0090]

[0091] As can be seen from the above table, the concrete specimens in the examples of the present invention exhibit good resistance to chloride ions and sulfate attack, and maintain good mechanical properties. Among them, by observing Comparative Example 3 and Examples 1-4, it is known that when the amount of recycled fine powder and modified weak basic anion resin is kept unchanged and the mass concentration of the barium nitrate solution used for modification is adjusted, it is found that with the increase of the mass concentration of the barium nitrate solution, the strength of the mass marine concrete can reach or even exceed the strength of the fly ash ordinary concrete.

[0092] In addition, when compared with fly ash ordinary concrete (Comparative Example 1), the chloride ion penetration resistance and sulfate ion resistance of mass marine concrete show a trend of first increasing and then decreasing with the increase of the mass concentration of barium nitrate solution. When the barium salt ions in the recycled fine powder and the modified weak basic anion resin reach a certain ratio, the corrosion resistance of the concrete reaches the best. Among the current examples, Example 3 shows the best performance. Further analyzing the change of the hydration temperature peak of the mass marine concrete in Example 3, it can be seen that the hydration temperature peak is also greatly reduced compared with that of fly ash ordinary concrete. Thus, it can be known that the mass concentration of the barium nitrate solution used for modification has a great influence on the strength, chloride ion penetration resistance, sulfate ion resistance, and hydration temperature peak of mass marine concrete. This is because within a certain range, as the mass concentration of the barium nitrate solution increases, the exchange capacity of the weak base anion resin will increase. More barium ions can combine with the exchangeable groups on the weak base anion resin, enabling the weak base anion resin to adsorb or exchange more target ions, thereby increasing the number of active sites available for exchange and further increasing the barium ion concentration inside the resin. When the mass concentration of the barium nitrate solution is too high, the inversion of the ion exchange equilibrium or an increase in the steric hindrance inside the weak base anion resin may occur. The excessively high barium ion concentration will reduce the barium ion concentration gradient around the resin surface, which is not conducive to the continuous progress of the ion exchange reaction. At the same time, too many barium ions may accumulate inside the resin particles, hindering other ions from approaching the exchangeable sites of the resin, resulting in the exchange capacity not increasing or even decreasing, and further reducing the barium ion concentration inside the resin. The barium ion concentration inside the resin not only affects the amount of barium sulfate precipitate formed but also affects the concentration of sulfate ions eroded into the concrete, which will subsequently affect the reaction of sulfate ions with C 3 A to generate AF t , affecting C 3 A will further react with the generated AFt to form AF m , affecting the formation of a diffusion barrier layer on the surface of C 3 A particles to slow down its hydration reaction, and finally leading to the occurrence of concrete hydration heat. Moreover, with the increase of the mass concentration of the barium nitrate solution, during the modification process of the weak base anion resin, it may affect the particle size, pore structure, and mechanical strength of the weak base anion resin.

[0093] Observing Example 3 and Comparative Example 8, when the barium nitrate solution is replaced with calcium nitrate, the sulfate resistance, sulfate corrosion resistance, and the ability to reduce hydration heat of the concrete will be weakened. Because the solubility of calcium sulfate is much higher than that of barium sulfate, and its solubility in water is strong. Since the content of sulfate ions in the marine environment is relatively low, there is a situation where barium sulfate precipitate is formed but calcium sulfate precipitate is not formed.

[0094] Observing Comparative Examples 1, 6, 7 and Example 3, it can be seen that the effect of separately incorporating recycled micropowder on enhancing the resistance to sulfate ions, sulfate corrosion and reducing the heat of hydration is relatively small. Separately incorporating weakly basic anion resin has a better effect than separately incorporating recycled micropowder, but both are less than the case of simultaneously incorporating modified weakly basic anion resin and recycled micropowder. When modified weakly basic anion resin and recycled micropowder are incorporated together, it can effectively and significantly enhance the resistance to sulfate ions, sulfate corrosion and reduce the heat of hydration, indicating that the incorporation of modified weakly basic anion resin and recycled micropowder has a synergistic enhancing effect.

[0095] Observing Example 3 and Examples 5 - 8, it can be known that when the mass concentration of the recycled micropowder and the barium nitrate solution used for modification is fixed, as the dosage of the modified weakly basic anion resin increases, the strength of the mass concrete at each age gradually increases, and the performance of resisting chloride ions and sulfate ions first increases and then decreases. From this, it can be seen that the dosage of the modified weakly basic anion resin has an important influence on the role played by the adsorbed barium ions in the concrete. Within a certain range, the more the dosage of the modified weakly basic anion resin, the more uniform its distribution in the concrete. When the dosage of the modified weakly basic anion resin incorporated is too much, it will affect the compactness of the internal structure of the concrete, and then affect the performance of the concrete in resisting chloride ions and sulfate ions. When the dosage of the modified weakly basic anion resin reaches a certain optimal dosage, the effect of the adsorbed barium ions is the best.

[0096] Observing Example 6 and Comparative Example 2, Example 1 and Comparative Example 3, Example 7 and Comparative Example 4, it is found that when the weakly basic anion resin is not modified, the incorporation of the weakly basic anion resin itself does not have a good enhancing effect on the concrete strength, chloride ion penetration resistance, sulfate ion resistance and hydration temperature peak. Comparing Comparative Examples 2 - 4 with Comparative Example 7, it is found that the effects of adding unmodified weakly basic anion resin and not adding weakly basic anion resin are the same, without obvious difference. This further shows that when the weakly basic anion resin is not modified, the incorporation of the weakly basic anion resin itself does not have a good enhancing effect on the concrete strength, chloride ion penetration resistance, sulfate ion resistance and hydration temperature peak.

[0097] Observing Example 3 and Comparative Example 5, after adjusting the D315 weakly basic acrylic acid - type anion resin to D201 strongly basic anion resin, the impermeability performance and sulfate corrosion resistance of the mass concrete are weakened. In the environment where the concrete is located, if there is sulfate, the D201 strongly basic anion resin will exchange a large amount of sulfate ions into the interior of the concrete, causing the sulfate ion concentration in the interior of the concrete to increase rapidly. When all the barium ions in the resin react with sulfate ions, the remaining aggregated sulfate ions instead create more favorable conditions for the sulfate to erode the concrete, weakening the impermeability performance and sulfate corrosion resistance.

[0098] Although the present invention has been described in detail above with general descriptions, specific embodiments and experiments, modifications or improvements can be made to it based on the present invention, which are obvious to those skilled in the art. Therefore, these modifications or improvements made without departing from the spirit of the present invention all fall within the scope of protection required by the present invention.

Claims

1. A corrosion-resistant large-volume marine engineering concrete, characterized in that: The large-volume marine engineering concrete comprises the following components by weight: 250-375 parts of cement, 25-100 parts of fly ash, 20-40 parts of recycled micropowder, 1-40 parts of modified weakly alkaline anion resin, 750-900 parts of machine-made sand, 900-1000 parts of ordinary crushed stone, 150-200 parts of water, and 5-20 parts of water reducer; The weakly basic anion resin used is modified before use, and the modification process is as follows: the weakly basic anion resin is soaked in a barium ion solution, and after the soaking is completed, a modified weakly basic anion resin is obtained; The weakly basic anion resin used is a weakly basic acrylic anion resin with a particle size of 0-2.56 mm and excluding 0; The regenerated micro powder has a calcium oxide content of 45%-50%, a silicon dioxide content of 34%-40%, an aluminum oxide content of 5%-10%, an iron oxide content of 2%-5%, and a fineness of 40-50 μm.

2. The corrosion-resistant large-volume marine concrete according to claim 1, characterized in that: The weakly basic anion resin used is D315 weakly basic acrylic anion resin.

3. The corrosion-resistant large-volume marine concrete according to claim 1, characterized in that: The barium ion-containing solution includes barium nitrate solution, barium carbonate solution, barium hydroxide solution, barium peroxide solution, barium chromate solution, and barium manganate solution; The mass concentration of the barium ion-containing solution is 20%-80%.

4. The corrosion-resistant large-volume marine concrete according to claim 1, characterized in that: The fly ash is Class II fly ash.

5. The corrosion-resistant large-volume marine concrete according to claim 1, characterized in that: The machine-made sand is medium-coarse sand, and its fineness modulus is between 2.1 and 3.

0.

6. The corrosion-resistant large-volume marine concrete according to claim 1, characterized in that: The water reducer is a polycarboxylate water reducer.

7. A method for preparing a corrosion-resistant large-volume marine concrete according to any one of claims 1 to 6, characterized in that: The following steps are involved: S1. Weigh cement, fly ash, recycled micro powder, modified weak alkaline anion resin, machine-made sand, ordinary crushed stone, water and water reducing agent for later use; S2. Stir and mix the weighed cement, fly ash, recycled micro powder, modified weak alkaline anion resin, machine-made sand, ordinary crushed stone and water reducing agent, then add water and stir and mix evenly to obtain corrosion-resistant large-volume marine engineering concrete.

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