An erosion-resistant hydraulic concrete and a method for producing the same

Abstract

The application provides an anti-erosion hydraulic concrete and a preparation method thereof, and belongs to the technical field of concrete. The concrete components include composite cement, high-activity nano-modified metakaolin, blast furnace slag powder, low-calcium fly ash, coarse aggregate, natural river sand fine aggregate, granite machine-made sand fine aggregate, erosion inhibitor, functional additive, early-strength polycarboxylate high-performance water reducing agent and composite air-entraining agent. The composite cement includes sulphoaluminate cement, Portland cement and polymer waterproof mortar. The high-activity nano-modified metakaolin is obtained by drying metakaolin modified by a silicone-ZnO composite emulsion. The erosion inhibitor includes organic carboxylate, hydrophobic-crystalline composite agent and pH buffer type corrosion inhibitor. The functional additive includes itaconic acid-acrylic acid copolymer, JRY-F concrete waterproof agent and polyethylene glycol-400 dilauryl ester. The composite air-entraining agent includes liquid sodium abietate and alpha-alkenyl sodium sulfonate. Through component synergy, modification and grading, an anti-erosion barrier is constructed.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of concrete, and particularly relates to an anti-erosion hydraulic concrete and a preparation method thereof. BACKGROUND

[0002] As the core material of water conservancy construction, hydraulic concrete bears the heavy responsibility of constructing various hydraulic structures such as dams, sluices, and water pipelines, and plays a key role in the rational use of water resources, flood control, irrigation, and power generation. Its development process is closely linked to the progress of water conservancy, and its technology is constantly innovated and its performance is gradually optimized.

[0003] Early hydraulic concrete, with relatively simple composition, is mainly composed of cement, aggregate, and water. However, with the continuous expansion of water conservancy projects and the increasing demand for engineering durability, this simple concrete soon exposed many problems. For example, in the long-term contact with water, its impermeability is insufficient, which leads to water easily penetrating into the interior of the concrete, causing steel corrosion, loose concrete structure, and other diseases; in cold regions, poor frost resistance makes the internal structure of the concrete suffer severe damage under the action of freeze-thaw cycles, greatly shortening the service life of hydraulic structures. To solve these problems, water-reducing agents, air-entraining agents, and other admixtures have been widely used in hydraulic concrete. In addition, mineral admixtures such as fly ash and slag powder have also gradually become an important part of hydraulic concrete.

[0004] With the continuous progress of material science and engineering technology, high-performance hydraulic concrete has emerged. This concrete further improves its overall performance by optimizing the mix design and using high-quality raw materials. For example, by adjusting the gradation of the aggregate, the density of the concrete is higher; using high-performance water-reducing agents, lower water-cement ratios are achieved, thereby improving the strength and durability of the concrete. At the same time, some new types of admixtures and admixtures are also emerging, such as silica fume, which has extremely high pozzolanic activity, can fill the pores inside the concrete, enhance the bonding force between the cement paste and the aggregate, and significantly improve the impermeability and erosion resistance of the concrete.

[0005] Although hydraulic concrete has made significant progress in technology, its erosion resistance still faces many challenges in practical application, and needs to be further improved. Hydraulic concrete is in a complex water environment for a long time and is affected by various erosion media. In addition to the common sulfate erosion, it may also be eroded by acid, alkali, seawater, and microorganisms, affecting the service life and safety.

[0006] In order to improve the anti-erosion performance of hydraulic concrete, it is necessary to start from multiple aspects. In the aspect of material research and development, new types of admixtures and admixtures should be continuously explored to optimize the microstructure of concrete and improve its anti-erosion ability. In the aspect of mix proportion design, the water-cement ratio, aggregate gradation and admixture content should be accurately adjusted to optimize the performance of concrete. In order to meet the increasing use requirements of hydraulic concrete. SUMMARY

[0007] In order to improve the anti-erosion performance of existing hydraulic concrete, it is necessary to improve the anti-erosion performance of existing hydraulic concrete. In order to meet the increasing use requirements of hydraulic concrete. The present application provides an anti-erosion hydraulic concrete and a preparation method thereof. The special compounded composite cement, high-activity nano-modified metakaolin, erosion inhibitor, functional additive, composite air-entraining agent and specific gradation of coarse aggregate and fine aggregate are used to prepare concrete. By optimizing the cementitious system and aggregate gradation, a high-density structure is formed to block the penetration path of moisture, sulfate, chloride ion and other erosion media from the physical level. With the help of functional additives, the erosion reaction is inhibited from the chemical level. At the same time, through the synergistic hydration reaction, the early and late strength, frost resistance and shrinkage resistance are considered. The durability short board of traditional hydraulic concrete caused by loose structure and insufficient impermeability is solved. Through the design of component material synergy, modification and particle size gradation, a multi-level anti-erosion barrier is built. The specific technical scheme is as follows:

[0008] An anti-erosion hydraulic concrete, comprising the following raw materials in parts by mass: composite cement 200-220 parts, high-activity nano-modified metakaolin 30-40 parts, blast furnace slag powder 80-100 parts, low-calcium fly ash 70-80 parts, coarse aggregate 1050-1100 parts, natural river sand fine aggregate 650-700 parts, granite machine-made sand fine aggregate 80-100 parts, erosion inhibitor 10-15 parts, functional additive 10-15 parts, early strength type polycarboxylate high-performance superplasticizer 5-7 parts, composite air-entraining agent 0.06-0.09 parts and water 135-150 parts;

[0009] The composite cement is compounded by sulphoaluminate cement, Portland cement and polymer waterproof mortar in a mass ratio of 1: (1.4-1.6): (0.2-0.3);

[0010] The high-activity nano-modified metakaolin is obtained by drying the metakaolin modified by organic silicon-ZnO composite emulsion; the organic silicon-ZnO composite emulsion is prepared from water, polyether modified organic silicon emulsion, KH-570 silane coupling agent and nano ZnO;

[0011] The coarse aggregate is compounded by basalt crushed stone and granite crushed stone in a mass ratio of 1: (1-1.5);

[0012] The erosion inhibitor is prepared by mixing organic carboxylic acid salt, hydrophobic-crystallization complexing agent and pH buffering corrosion inhibitor in a mass ratio of (1.0-1.5):(3.0-4.5):(1.7-2.4); the organic carboxylic acid salt is prepared by mixing sodium citrate and potassium tartrate in a mass ratio of (2-2.5):(1-1.2); the hydrophobic-crystallization complexing agent is prepared by mixing hydrophobic nano-silicon dioxide and crystalline active component CaSiO3 in a mass ratio of 1:(1-1.5); the pH buffering corrosion inhibitor is prepared by mixing sodium molybdate and cyclohexylamine in a mass ratio of (4-5):1.

[0013] The functional aid is prepared by mixing itaconic acid acrylic acid copolymer, JRY-F concrete waterproofing agent and polyethylene glycol-400 dilauryl ester in a mass ratio of 3:(1-1.5):(0.6-0.8).

[0014] The composite air entraining agent is prepared by mixing liquid sodium abietate and sodium alpha-alkenyl sulfonate in a mass ratio of 5:(1-1.5).

[0015] In the concrete, the high-activity nano-modified metakaolin is prepared by mixing metakaolin and organic silicon-ZnO composite emulsion, drying and airflow pulverizing to D50 of 3 microns or less to obtain high-activity nano-modified metakaolin.

[0016] In the preparation method of the high-activity nano-modified metakaolin, the particle size of the metakaolin is 650-800 mesh; the amount of the organic silicon-ZnO composite emulsion is 15-20% of the mass of the metakaolin; the organic silicon-ZnO composite emulsion is prepared by mixing water, polyether-modified organic silicon emulsion, KH-570 silane coupling agent and nano-ZnO in a mass ratio of 10:(3-5):(0.5-0.8):(1.5-2) and adjusting pH to 8.3-8.8; the solid content of the polyether-modified organic silicon emulsion is 60-65 wt%; and the drying temperature is 60-65℃.

[0017] In the concrete, the D50 of the blast furnace slag powder is 10 microns or less.

[0018] In the concrete, the D50 of the low-calcium fly ash is 50 microns or less, and the CaO content is less than 5 wt%.

[0019] In the concrete, the continuous grading of the coarse aggregate is: 5-10 mm accounts for 30-35 wt%, 10-18 mm accounts for 35-40 wt%, and 18-25 mm accounts for 25-30 wt%.

[0020] In the concrete, the intermittent grading of the natural river sand fine aggregate is as follows: the interval of 40 meshes to 50 meshes accounts for 35wt% to 40wt%, the interval of 60 meshes to 80 meshes accounts for 45wt% to 50wt%, and the interval of 100 meshes to 120 meshes accounts for 15wt% to 20wt%.

[0021] In the concrete, the intermittent grading of the granite machine-made sand fine aggregate is as follows: the interval of 50 meshes to 70 meshes accounts for 60wt% to 70wt%, and the interval of 100 meshes to 150 meshes accounts for 30wt% to 40wt%.

[0022] In the concrete, the index of the water is as follows: the content of chloride ions is less than 200mg / L, and the content of sulfate ions is less than 600mg / L.

[0023] The preparation method of the anti-erosion hydraulic concrete comprises the following steps:

[0024] S1: mixing, according to mass fractions, the composite cement, the blast furnace slag powder and the low-calcium fly ash to obtain a mixture;

[0025] S2: mixing, according to mass fractions, the coarse aggregate, the natural river sand fine aggregate and the granite machine-made sand fine aggregate; then adding 70wt% to 80wt% of water, the early-strength type polycarboxylate high-performance water reducing agent and the composite air-entraining agent for mixing; then adding the mixture, the high-activity nano-modified metakaolin, the erosion inhibitor and the functional additive for mixing; finally adding the remaining water for mixing to obtain the concrete.

[0026] The anti-erosion hydraulic concrete and the preparation method thereof have the beneficial effects as follows:

[0027] Firstly, the anti-erosion hydraulic concrete forms a high-density structure by optimizing the cementitious system and the aggregate grading, thereby blocking the penetration path of the erosion medium such as water, sulfate and chloride ions from the physical level; the erosion reaction is inhibited from the chemical level by means of the functional additives; meanwhile, the early and late strength, the frost resistance and the anti-shrinkage performance are considered by means of the synergistic hydration reaction, so that the short board of the durability of the traditional hydraulic concrete caused by the loose structure and the insufficient impermeability is solved, and the multi-level anti-erosion barrier is constructed by means of the synergy, modification and particle size grading of the designed component materials.

[0028] Secondly, the composite cement is compounded by the sulphoaluminate cement, the portland cement and the polymer waterproof mortar according to a specific proportion, the sulphoaluminate cement has fast hydration, high early strength and low Ca(OH)2 content in the hydration product, the portland cement provides late strength support, and the two form a double-gel structure to consider the early and late strength; the polymer waterproof mortar fills the capillary pores and microcracks in the cement stone to form a continuous hydrophobic system, thereby blocking the penetration path of the erosion medium, and improving the interface bonding between the cement and the aggregate and reducing the interface pores.

[0029] Three, high-activity nano-modified metakaolin: after modified by silicone-ZnO composite emulsion, the silicone chain segment forms a hydrophobic film to avoid particle agglomeration, and nano-ZnO fills the micropores, combined with the ultra-fine particle size (D50 < 3 μm) after airflow crushing, significantly improving the compactness of concrete, enhancing the impermeability and corrosion resistance. Blast furnace slag powder (D50 < 10 μm) participates in the later hydration reaction, supplements the generation of C-S-H gel, and enhances the stability of concrete structure. Low-calcium fly ash (D50 < 50 μm, CaO < 5 wt%) fills the voids of the cementitious system through particle size optimization, reduces porosity, and improves density.

[0030] Four, coarse aggregate uses basalt and granite crushed stones in a specific ratio and designs continuous gradation to reduce voids and enhance the skeleton support effect through different particle sizes.

[0031] Five, fine aggregate uses natural river sand and granite machine-made sand in a specific ratio and designs intermittent gradation: river sand is mainly 40-50 mesh and 60-80 mesh, and machine-made sand is mainly 50-70 mesh, the particle sizes of the two are complementary to achieve "coarse-medium-fine" continuous filling, reduce the void ratio of fine aggregate, and the angular structure of granite machine-made sand enhances the biting effect with cement paste, improving the interface transition zone.

[0032] Six, erosion inhibitor: organic carboxylate (sodium citrate + potassium tartrate) chelates free Ca 2+ , reduces sulfate reaction raw materials; hydrophobic-crystalline complex agent (hydrophobic nano-SiO2 + CaSiO3) forms a hydrophobic layer and generates calcium silicate crystals to block micropores; pH buffer type corrosion inhibitor (sodium molybdate + cyclohexylamine) stabilizes the internal environment and synergistically inhibits the erosion reaction.

[0033] Seven, functional additives: itaconic acid acrylic copolymer disperses cementitious particles through electrostatic repulsion to avoid agglomeration; JRY-F waterproofing agent enhances impermeability; polyethylene glycol-400 dilaurate retains water (reduces drying cracks) and plasticizes (improves vibration compaction).

[0034] Eight, composite air entraining agent (liquid sodium abietate + α-alkyl sodium sulfonate): α-alkyl sodium sulfonate efficiently introduces small air bubbles, and liquid sodium abietate stabilizes the bubble film. The bubbles absorb and expand stress in freeze-thaw cycles, improving frost resistance.

[0035] Nine, preparation steps: stage mixing (first aggregate with part of water and water reducing agent, then adding cementitious materials, etc.) to ensure uniform material dispersion; control mixing speed and time to avoid excessive stirring leading to bubble escape or particle agglomeration.

[0036] Ten, the components of concrete achieve performance leap through three-dimensional synergy of "structure-function-reaction":

[0037] (1) Structure synergy: The double gel structure of composite cement and the ultra-fine particles of mineral admixtures (metakaolin, slag powder, fly ash) form a dense matrix, combined with the optimization of aggregate gradation (continuous gradation + intermittent gradation), to reduce porosity from macro to micro, providing a physical basis for erosion resistance.

[0038] (2) Functional synergy: The "chelation-hydrophobic-buffering" function of the erosion inhibitor and the "hydrophobic-filling" effect of the high-activity nano-modified metakaolin are superimposed, which not only blocks the penetration of erosion medium, but also inhibits its reaction with cement hydration products; The "water retention-foam stabilization" synergy of composite air entraining agent and functional additives improves frost resistance while reducing drying shrinkage.

[0039] (3) Reaction synergy: The early hydration of sulphoaluminate cement and the late hydration of Portland cement and slag powder complement each other to avoid the strength development fault; The interface optimization synergy of polymer waterproof mortar and aggregate reduces the defects in the interface transition zone and enhances the overall structural stability, making the concrete achieve better performance in strength, impermeability, erosion resistance and other properties. DETAILED DESCRIPTION

[0040] The application will be further described below in conjunction with specific implementation examples, but the application is not limited to these examples.

[0041] Example 1

[0042] An anti-erosion hydraulic concrete, comprising the following raw materials in mass fraction: composite cement 200 parts, high-activity nano-modified metakaolin 30 parts, blast furnace slag powder 80 parts, low calcium fly ash 70 parts, coarse aggregate 1050 parts, natural river sand fine aggregate 650 parts, granite machine-made sand fine aggregate 80 parts, erosion inhibitor 10 parts, functional additive 10 parts, early strength type polycarboxylate high performance water reducing agent 5 parts, composite air entraining agent 0.06 parts and water 135 parts.

[0043] The composite cement is prepared by mixing sulphoaluminate cement, Portland cement and polymer waterproof mortar in a mass ratio of 1:1.5:0.25.

[0044] The preparation method of the high-activity nano-modified metakaolin comprises: mixing water, polyether modified organosilicon emulsion, KH-570 silane coupling agent and nano-ZnO in a mass ratio of 10:3:0.5:1.5, adjusting the pH to 8.3 to obtain an organosilicon-ZnO composite emulsion; sieving the metakaolin through a 650-mesh sieve; spraying the metakaolin in a stirring state with 15% of the organosilicon-ZnO composite emulsion based on the mass of the metakaolin, mixing uniformly, drying at 60°C until constant weight, and airflow pulverizing to D50 of 3 μm or less to obtain the high-activity nano-modified metakaolin.

[0045] The blast furnace slag powder has a D50 of 10 μm or less. The low calcium fly ash has a D50 of 50 μm or less and a CaO content of 3.6 wt%.

[0046] The coarse aggregate is made of basalt gravel and granite gravel in a mass ratio of 1:1; the continuous gradation of the coarse aggregate is: 5mm≤particle size<10mm accounts for 30wt%, 10≤particle size<18mm accounts for 40wt%, and 18≤particle size<25mm accounts for 30wt%. The discontinuous gradation of the natural river sand fine aggregate is: 40mesh~50mesh accounts for 35wt%, 60mesh~80mesh accounts for 50wt%, and 100mesh~120mesh accounts for 15wt%, with a mud content of 2.8wt%. The discontinuous gradation of the granite machine-made sand fine aggregate is: 50mesh~70mesh accounts for 65wt%, and 100mesh~150mesh accounts for 35wt%.

[0047] The erosion inhibitor is made of organic carboxylic acid salt, hydrophobic-crystalline composite agent and pH buffer type corrosion inhibitor in a mass ratio of 1.0:3.0:1.7. The organic carboxylic acid salt is made of sodium citrate and potassium tartrate in a mass ratio of 2:1; the hydrophobic-crystalline composite agent is made of hydrophobic nano-silicon dioxide and crystalline active component CaSiO3 in a mass ratio of 1:1; the pH buffer type corrosion inhibitor is made of sodium molybdate and cyclohexylamine in a mass ratio of 4:1.

[0048] The functional aid is made of itaconic acid acrylic acid copolymer, JRY-F concrete waterproof agent and polyethylene glycol-400 dilauryl ester in a mass ratio of 3:1:0.6.

[0049] The composite air entraining agent is made of liquid sodium abietate and α-alkenyl sodium sulfonate in a mass ratio of 5:1.

[0050] The water has an index of: chloride ion content 170mg / L, sulfate ion 385mg / L.

[0051] The preparation method of the above-mentioned anti-erosion hydraulic concrete comprises the following steps:

[0052] S1: mix the composite cement, blast furnace slag powder and low calcium fly ash in a mass ratio of 30rpm for 2min to obtain a mixture;

[0053] S2: mix the coarse aggregate, natural river sand fine aggregate and granite machine-made sand fine aggregate in a mass ratio of 15rpm for 2min; then add 70wt% water, early strength type polycarboxylate high performance superplasticizer and composite air entraining agent, and mix at 35rpm for 3min; then add the mixture, high-activity nano-modified metakaolin, erosion inhibitor and functional aid, and mix at 35rpm for 2min; finally add the remaining water, and mix at 35rpm for 1min to obtain the concrete.

[0054] Example 2

[0055] An anti-erosion hydraulic concrete comprises the following raw materials in mass fractions: composite cement 210 parts, high-activity nano-modified metakaolin 35 parts, blast furnace slag powder 90 parts, low-calcium fly ash 75 parts, coarse aggregate 1080 parts, natural river sand fine aggregate 675 parts, granite machine-made sand fine aggregate 90 parts, erosion inhibitor 13 parts, functional additive 12 parts, early-strength polycarboxylate high-performance water reducing agent 6 parts, composite air-entraining agent 0.07 parts and water 142 parts.

[0056] The composite cement is prepared by mixing sulphoaluminate cement, Portland cement and polymer waterproof mortar at a mass ratio of 1:1.4:0.2.

[0057] The preparation method of the high-activity nano-modified metakaolin comprises the following steps: mixing water, polyether-modified silicone emulsion, KH-570 silane coupling agent and nano-ZnO at a mass ratio of 10:4:0.7:1.8, adjusting pH to 8.5 to obtain an organic silicon-ZnO composite emulsion; screening metakaolin through an 800-mesh sieve; spraying the metakaolin in a stirring state with the organic silicon-ZnO composite emulsion at 18% of the mass of the metakaolin, uniformly mixing, drying at 62℃ until constant weight, and airflow pulverizing to less than 3μm in D50 to obtain the high-activity nano-modified metakaolin.

[0058] The blast furnace slag powder has a D50 of less than 10μm. The low-calcium fly ash has a D50 of less than 50μm and a CaO content of 4.2wt%.

[0059] The coarse aggregate is prepared by mixing basalt crushed stone and granite crushed stone at a mass ratio of 1:1.2; the continuous grading of the coarse aggregate is: 5mm≤particle size<10mm accounts for 35wt%, 10≤particle size<18mm accounts for 35wt%, and 18≤particle size<25mm accounts for 30wt%. The natural river sand fine aggregate has an intermittent grading of: 40-mesh~50-mesh accounts for 40wt%, 60-mesh~80-mesh accounts for 45wt%, 100-mesh~120-mesh accounts for 15wt%, and the mud content is 2.2wt%. The intermittent grading of the granite machine-made sand fine aggregate is: 50-mesh~70-mesh accounts for 60wt%, and 100-mesh~150-mesh accounts for 40wt%.

[0060] The erosion inhibitor is prepared by mixing organic carboxylate, hydrophobic-crystalline composite agent and pH buffering corrosion inhibitor at a mass ratio of 1.3:3.8:2.0. The organic carboxylate is prepared by mixing sodium citrate and potassium tartrate at a mass ratio of 2.3:1.1; the hydrophobic-crystalline composite agent is prepared by mixing hydrophobic nano-silicon dioxide and crystalline active component CaSiO3 at a mass ratio of 1:1.2; and the pH buffering corrosion inhibitor is prepared by mixing sodium molybdate and cyclohexylamine at a mass ratio of 4.5:1.

[0061] The functional additive is prepared by mixing itaconic acid acrylic acid copolymer, JRY-F concrete waterproof agent and polyethylene glycol-400 dilauryl ester at a mass ratio of 3:1.3:0.7.

[0062] The composite air entraining agent is prepared by mixing liquid sodium abietate and sodium alpha-olefin sulfonate at a mass ratio of 5:1.2.

[0063] The index of water is: chloride ion content 154mg / L, sulfate ion 526mg / L.

[0064] The preparation method of the anti-erosion hydraulic concrete comprises the following steps:

[0065] S1: according to the mass fraction, the composite cement, the blast furnace slag powder and the low calcium fly ash are mixed at 32 rpm for 1.5 min to obtain a mixture;

[0066] S2: according to the mass fraction, the coarse aggregate, the natural river sand fine aggregate and the granite machine-made sand fine aggregate are mixed at 18 rpm for 1.5 min; then 75wt% water, the early strength type polycarboxylate high performance water reducing agent and the composite air entraining agent are added and mixed at 32 rpm for 4 min; then the mixture, the high activity nano modified metakaolin, the erosion inhibitor and the functional additive are added and mixed at 32 rpm for 2.5 min; finally, the remaining water is added and mixed at 32 rpm for 1.5 min to obtain the concrete.

[0067] Example 3

[0068] An anti-erosion hydraulic concrete comprises the following raw materials in mass fraction: composite cement 220 parts, high activity nano modified metakaolin 40 parts, blast furnace slag powder 100 parts, low calcium fly ash 80 parts, coarse aggregate 1100 parts, natural river sand fine aggregate 700 parts, granite machine-made sand fine aggregate 100 parts, erosion inhibitor 15 parts, functional additive 15 parts, early strength type polycarboxylate high performance water reducing agent 7 parts, composite air entraining agent 0.09 parts and water 150 parts.

[0069] The composite cement is prepared by mixing sulphoaluminate cement, Portland cement and polymer waterproof mortar at a mass ratio of 1:1.6:0.3.

[0070] The preparation method of the high activity nano modified metakaolin comprises the following steps: mixing water, polyether modified silicone emulsion, KH-570 silane coupling agent and nano ZnO at a mass ratio of 10:5:0.8:2, adjusting pH to 8.8 to obtain an organic silicon-ZnO composite emulsion; screening the metakaolin through an 800 mesh screen; spraying the metakaolin in a stirring state with the organic silicon-ZnO composite emulsion at 20% of the mass of the metakaolin, uniformly mixing, drying at 65 DEG C until constant weight, and airflow pulverizing to D50 of 3 microns or less to obtain the high activity nano modified metakaolin.

[0071] The D50 of the blast furnace slag powder is 10 microns or less. The D50 of the low calcium fly ash is 50 microns or less, and the CaO content is 4.5wt%.

[0072] The coarse aggregate is made of basalt gravel and granite gravel in a mass ratio of 1:1.5; the continuous grading of the coarse aggregate is: 5mm≤particle size<10mm accounts for 35wt%, 10≤particle size<18mm accounts for 40wt%, and 18≤particle size<25mm accounts for 25wt%. The discontinuous grading of the natural river sand fine aggregate is: 40mesh~50mesh accounts for 35wt%, 60mesh~80mesh accounts for 45wt%, and 100mesh~120mesh accounts for 20wt%, with a mud content of 2.5wt%. The discontinuous grading of the granite machine-made sand fine aggregate is: 50mesh~70mesh accounts for 70wt%, and 100mesh~150mesh accounts for 30wt%.

[0073] The erosion inhibitor is made of organic carboxylic acid salt, hydrophobic-crystalline composite agent and pH buffering corrosion inhibitor in a mass ratio of 1.5:4.5:2.4. The organic carboxylic acid salt is made of sodium citrate and potassium tartrate in a mass ratio of 2.5:1.2; the hydrophobic-crystalline composite agent is made of hydrophobic nano-silicon dioxide and crystalline active component CaSiO3 in a mass ratio of 1:1.5; the pH buffering corrosion inhibitor is made of sodium molybdate and cyclohexylamine in a mass ratio of 5:1.

[0074] The functional aid is made of itaconic acid acrylic acid copolymer, JRY-F concrete waterproof agent and polyethylene glycol-400 dilauryl ester in a mass ratio of 3:1.5:0.8.

[0075] The composite air entraining agent is made of liquid sodium abietate and α-alkenyl sodium sulfonate in a mass ratio of 5:1.5.

[0076] The water has an index of: chloride ion content 125mg / L, and sulfate ion 438mg / L.

[0077] The preparation method of the above-mentioned anti-erosion hydraulic concrete comprises the following steps:

[0078] S1: mix the composite cement, blast furnace slag powder and low-calcium fly ash in a mass ratio of 35rpm for 1min to obtain a mixture;

[0079] S2: mix the coarse aggregate, natural river sand fine aggregate and granite machine-made sand fine aggregate in a mass ratio of 20rpm for 1min; then add 80wt% water, early strength type polycarboxylate high-performance superplasticizer and composite air entraining agent, and mix at 30rpm for 5min; then add the mixture, high-activity nano-modified metakaolin, erosion inhibitor and functional aid, and mix at 30rpm for 3min; finally add the remaining water, and mix at 30rpm for 2min to obtain the concrete.

[0080] The raw materials used in the above examples are as follows: the sulphoaluminate cement is from Wuxi Jingpeng New Building Material Co., Ltd., low alkali. The Portland cement is from Ningguo Cement Plant of Anhui Conch Cement Co., Ltd., P.II 52.5R Portland cement. The polymer waterproof mortar is from Wuxi Jingpeng New Building Material Co., Ltd., cement-based solid material. The polyether modified silicone emulsion is from Dongguan Haoyouduo New Material Co., Ltd., product code D-001, solid content adjusted to 60wt%-65wt%. The silane coupling agent KH-570 is from Dongguan Kangjin New Material Technology Co., Ltd. The nano-ZnO is from Hangzhou Jiupeng New Material Co., Ltd., model J50, specification 50nm grade. The metakaolin is from Guangzhou Changyu Chemical Co., Ltd., undersize product after screening with 650-800 mesh screen. The blast furnace slag powder is from Lingshou Yaoxin Mineral Product Processing Plant, S95 mineral powder. The low-calcium fly ash is from Shijiazhuang Xuhann New Material Technology Co., Ltd. The sodium citrate is from Suzhou Yueda Chemical Co., Ltd. The potassium tartrate is from Henan Chengke New Material Technology Co., Ltd. The hydrophobic nano-silica is from Jiangsu Tianxing New Material Co., Ltd., model TSP-L12, specification 20nm grade. The crystalline active component CaSiO3 is from Jinan Zhiheng Chihuan Chemical Technology Co., Ltd., anhydrous calcium sulfate. The sodium molybdate is from Henan Zhongjie Chemical Product Co., Ltd. The cyclohexylamine is from Shandong Qiyun Chemical Technology Co., Ltd. The itaconic acid-acrylic acid copolymer is from Changzhou Runyang Chemical Co., Ltd., model GY-318. The JRY-F concrete waterproofing agent is from Shanxi Jinyongyuan Building Material Technology Co., Ltd. The polyethylene glycol-400 dilaurate is from Haian Petroleum Chemical Plant of Jiangsu Province, specification PEG400DL. The early-strength polycarboxylate high-performance water reducing agent is from Shanxi Jinyongyuan Building Material Technology Co., Ltd., JRY-A polycarboxylate high-performance water reducing agent (early-strength type). The liquid sodium abietate is from Zhengzhou Chengao Chemical Product Co., Ltd. The sodium α-alkenyl sulfonate is from Zhongqing Chemical Co., Ltd.

[0081] Comparative Example 1

[0082] The difference from Example 1 is that the composite cement is compounded by sulphoaluminate cement and Portland cement at a mass ratio of 1:1.75, i.e. without adding polymer waterproof mortar.

[0083] Comparative Example 2

[0084] The difference from Example 1 is that the composite cement is compounded by Portland cement, sulphoaluminate cement and polymer waterproof mortar at a mass ratio of 1:1.5:0.25, i.e. the proportion of sulphoaluminate cement and Portland cement is interchanged.

[0085] Comparative Example 3

[0086] The difference from Example 1 is that the high-activity nano-modified metakaolin is directly replaced by metakaolin, i.e. without high-activity nano-modification.

[0087] Comparative Example 4

[0088] The difference from Example 1 is that the high-activity nano-modified metakaolin is not added in the preparation of the high-activity nano-modified metakaolin.

[0089] Comparative Example 5

[0090] The difference from Example 1 is that the natural river sand fine aggregate is replaced by 730 parts, and the granite machine-made sand fine aggregate is replaced by 0 parts.

[0091] Comparative Example 6

[0092] The difference from Example 1 is that the intermittent grading of the granite machine-made sand fine aggregate is: 40-50 mesh interval accounts for 35wt%, 60-80 mesh interval accounts for 50wt%, and 100-120 mesh interval accounts for 15wt%, i.e. the same as the natural river sand fine aggregate grading.

[0093] Comparative Example 7

[0094] The difference from Example 1 is that in the erosion inhibitor, all the organic carboxylate is sodium citrate; all the hydrophobic-crystalline composite agent is hydrophobic nano-silicon dioxide; and all the pH buffer type corrosion inhibitor is sodium molybdate.

[0095] Comparative Example 8

[0096] The difference from Example 1 is that in the erosion inhibitor, no hydrophobic-crystalline composite agent is added.

[0097] Comparative Example 9

[0098] The difference from Example 1 is that the erosion inhibitor is composed of organic carboxylate, hydrophobic-crystalline composite agent and pH buffer type corrosion inhibitor with a mass ratio of 3.0:1.7:1.0, i.e. the ratio is changed.

[0099] Comparative Example 10

[0100] The difference from Example 1 is that the functional adjuvant does not contain itaconic acid-acrylic acid copolymer.

[0101] Comparative Example 11

[0102] The difference from Example 1 is that the functional adjuvant does not contain polyethylene glycol-400 bis laurate.

[0103] Comparative Example 12

[0104] The difference from Example 1 is that the functional adjuvant is composed of acrylic acid and itaconic acid copolymer, JRY-F concrete waterproofing agent and polyethylene glycol-400 dilaurate in a mass ratio of 0.6:3:1, i.e. the ratio is changed.

[0105] Comparative Example 13

[0106] The difference from Example 1 is that the composite air entraining agent is all sodium liquid rosin acid.

[0107] Comparative Example 14

[0108] The difference from Example 1 is that the composite air entraining agent is all sodium a-alkenyl sulfonate.

[0109] Comparative Example 15

[0110] The difference from Example 1 is that the composite air entraining agent is composed of sodium liquid rosin acid and sodium a-alkenyl sulfonate in a mass ratio of 1:5, i.e. the ratio is changed.

[0111] The performance of the concrete of each of the above examples and comparative examples is detected, as follows:

[0112] Table 1. Detection items and parameters

[0113]

[0114] Sample preparation and curing: the concrete is poured and vibrated on a vibration table (frequency 50 Hz, amplitude 0.5 mm), and is left to stand for 24 h at 20±5℃, RH≥80% to remove the formwork, and is immediately transferred to a standard curing room at 20±2℃, RH≥95% for curing until the required specified age for testing. There are 5 parallel samples in each group; the detection results are shown in Table 2 below.

[0115] Table 2. Detection results (interval value of parallel samples)

[0116]

[0117] From the above results, it can be seen that the concrete of Examples 1 to 3 provides a scientific material ratio and particle size grading, and at the same time has good strength, impermeability and corrosion resistance.

[0118] Comparative Example 1 (composite cement without polymer waterproofing mortar):

[0119] The polymer waterproofing mortar can on the one hand fill the capillary pores and microcracks inside the cement stone, form a continuous hydrophobic system, and block water, SO4 2- , Cl -On the one hand, the polymer can penetrate into the interface transition zone between the cement and the aggregate, improve the interface bonding state, and reduce the interface pores. After the component is missing, the porosity of the cement stone increases significantly, and the penetration channels increase: not only the anti-permeability decreases, but also the erosion medium is more likely to enter the interior and react with the cement hydration products to generate expansive ettringite, causing the concrete volume deformation to intensify; at the same time, the interface transition zone bonding force weakens, the compressive strength development is hindered, and the water in the pores is more likely to freeze and expand in the freeze-thaw cycle, intensifying the structure damage.

[0120] Comparative Example 2 (the proportion of sulphoaluminate cement and Portland cement is interchanged in the composite cement): there are essential differences in the hydration characteristics of sulphoaluminate cement and Portland cement, the hydration speed of sulphoaluminate cement is fast, and dense calcium sulphoaluminate hydrate crystals can be generated early, and the content of Ca(OH)2 in the hydration product is low; while the hydration of Portland cement generates hydration calcium silicate (C-S-H) gel with weak density, and a large amount of Ca(OH)2 is precipitated. After the proportion is interchanged, the proportion of sulphoaluminate cement decreases: first, the density of early hydration product is insufficient, the porosity of the cement stone increases, and the anti-permeability decreases; second, the content of Ca(OH)2 increases, which can further react with calcium aluminate to generate ettringite, and intensify the sulfate erosion damage; third, the hydration heat release rate slows down, the early strength development lags behind, and the overall structure density formation is delayed. 2- Providing more reaction sites to further react with calcium aluminate to generate ettringite, and intensifying the sulfate erosion damage; third, the hydration heat release rate slows down, the early strength development lags behind, and the overall structure density formation is delayed.

[0121] Comparative Example 3 (high-activity nano-modified metakaolin is replaced by unmodified metakaolin): the performance of the "high-activity nano-modified metakaolin" in the embodiment depends on two modification mechanisms: first, the hydrophobic film formed by the organosilicon-ZnO composite emulsion on the surface of metakaolin reduces its surface energy and avoids aggregation; second, the introduction of nano-ZnO can fill the micropores. The unmodified metakaolin has no above-mentioned functions, and the metakaolin is easy to aggregate without the protection of the hydrophobic film, which not only cannot fill the micropores, but also forms gaps between the aggregates, becoming new channels for the erosion medium; and the water is easy to stay in the pores in the freeze-thaw cycle, intensifying the freezing damage.

[0122] Comparative Example 4 (high-activity nano-modified metakaolin prepared without polyether-modified silicone emulsion): The polyether-modified silicone emulsion plays three major roles in the modification process: first, as a dispersant, its polyether segment can adsorb on the surface of metakaolin particles, preventing particle agglomeration through steric hindrance, ensuring stable metakaolin particle size; second, as a hydrophobic modifier, its silicone segment can form a continuous hydrophobic layer on the surface of metakaolin, reducing the hydrophilicity of cement stone; third, as a compatibility regulator, it enhances the interfacial bonding between metakaolin and cement paste, preventing the modified particles from separating from the cement paste. Without this component, metakaolin particles agglomerate severely due to high surface energy: on the one hand, the agglomerates cannot uniformly fill the pores of cement stone, instead forming large-sized gaps, increasing the number of penetration channels; on the other hand, the agglomerated metakaolin cannot fully contact Ca(OH)2, resulting in insufficient reaction and reduced C-S-H gel production, leading to decreased cement stone density; meanwhile, the absence of a hydrophobic layer leads to increased water absorption of cement stone, more severe ice expansion damage during freeze-thaw cycles, and intensified drying shrinkage due to increased porosity.

[0123] Comparative Example 5 (granite mechanism sand fine aggregate increased to 0 parts, natural river sand increased to 730 parts): There are key differences in particle shape and grading characteristics between granite mechanism sand and natural river sand. Granite mechanism sand is angular and has a 65% share of 50-70 mesh coarse particle size in the discontinuous grading, which can enhance the mechanical bonding force with cement paste through angular interlocking and fill the gaps of natural river sand (35% of 40-50 mesh), reducing the overall void ratio of fine aggregate. Natural river sand is round or oval, has weak interlocking effect, and has a high void ratio in single grading. Without granite mechanism sand: first, the void ratio of fine aggregate increases, requiring more cement paste to fill, resulting in a decrease in effective cementitious materials participating in the cementation reaction, limiting the development of compressive strength; second, the interlocking effect between aggregate and cement paste is weakened, and microcracks are easily generated in the interfacial transition zone, becoming a weak link for the penetration of erosion medium; third, the single natural river sand has poor continuous grading, and the uniformity of the internal structure of concrete decreases, affecting the impermeability and frost resistance.

[0124] Comparative Example 6 (granite mechanism sand grading is the same as natural river sand): The core of the grading design of "natural river sand + granite mechanism sand" in the example is "complementary filling": natural river sand mainly has medium particle size (60-80 mesh), and granite mechanism sand mainly has coarse particle size (50-70 mesh), and the two are combined to achieve continuous filling of fine aggregate from coarse to fine, minimizing void ratio. After overlapping the grading, the coarse particle size (50-70 mesh) share is insufficient, and the fine aggregate system has the problem of "medium particle size enrichment and coarse particle size deficiency": on the one hand, the void ratio increases, and more cementitious materials are needed to fill the cement stone, leading to decreased structural density and weakened impermeability; on the other hand, the coarse particle size aggregate share is insufficient, and the "skeletal support" effect between aggregates is weakened, hindering the development of compressive strength.

[0125] Comparative Example 7 (erosion inhibitor single component instead of composite component): the function of the erosion inhibitor depends on "multi-component synergy", and single replacement destroys the synergy mechanism: (1) sodium citrate (strong Ca 2+ chelating ability) and potassium tartrate (high corrosion inhibition efficiency) are compounded, sodium citrate chelates free Ca 2+ in concrete, reducing the raw materials for the formation of gypsum and ettringite, and potassium tartrate forms an adsorption film on the surface of cement particles to inhibit the reaction of calcium aluminate hydrate and SO4 2- ; single sodium citrate cannot simultaneously achieve "chelation + corrosion inhibition", and the reaction rate of SO4 2- significantly increases. (2) Hydrophobic nano-silica forms a hydrophobic layer on the surface of cement stone, reducing water intrusion, and CaSiO3 (crystalline active component) reacts with cement hydration products to form fibrous calcium silicate crystals, blocking internal micropores; single hydrophobic nano-silica can only prevent surface water penetration and cannot repair internal pores, so the penetration channel still exists. Single sodium molybdate has poor synergy film formation and stability with other components.

[0126] Comparative Example 8 (no hydrophobic-crystalline complex added in the erosion inhibitor): the hydrophobic-crystalline complex is the core component of the erosion inhibitor: hydrophobic nano-silica reduces water adsorption and penetration on the surface of cement stone through physical filling and hydrophobic modification; CaSiO3 crystallizes in the micropores and cracks inside the cement stone, and the generated calcium silicate crystals gradually block the penetration channel, forming a "self-repairing" effect. Without this component, the erosion inhibitor only retains the functions of "chelating Ca 2+ + buffering pH", and cannot solve the "penetration channel" problem: on the one hand, water and erosion medium can still penetrate into the interior through micropores, and the reaction between SO4 2- , Cl - and cement hydration products continues to occur; on the other hand, the internal micropores cannot be blocked by crystallization, and water is easily retained in the pores during freeze-thaw cycles, leading to structure damage due to ice expansion, and the compressive strength decreases due to the increase in internal porosity.

[0127] Comparative Example 9 (change of component ratio of the erosion inhibitor): the design logic of the original ratio is "anti-permeation as the core, supplemented by chelation and pH buffering", and the hydrophobic-crystalline complex has the highest proportion, which prioritizes the construction of "hydrophobic + pore blocking" anti-permeation barrier to reduce the intrusion of erosion medium, at which time a small amount of organic carboxylate and pH buffering corrosion inhibitor can inhibit the remaining erosion reaction. After the ratio is changed, the proportion of the hydrophobic-crystalline complex is insufficient: first, the anti-permeation barrier cannot be effectively formed, and the amount of water and erosion medium intrusion increases, far exceeding the chelating capacity of the organic carboxylate, and SO4 2-The reaction with the cement hydration product is intensified; the proportion of the pH buffer type corrosion inhibitor is reduced, which cannot stabilize the internal environment of the concrete; meanwhile, the excess organic carboxylate salt slightly inhibits the cement hydration, resulting in a decrease in the amount of C-S-H gel generated and a hindered development of the compressive strength.

[0128] Comparative Example 10 (no itaconic acid-acrylic acid copolymer is added in the functional additive): The itaconic acid-acrylic acid copolymer is the “dispersion core” in the functional additive, which is electrostatically adsorbed on the surface of cement, high-activity nano-modified metakaolin, blast furnace slag powder and other cementitious materials particles, and prevents particle agglomeration through electrostatic repulsion and steric hindrance effect, so that the cementitious materials are uniformly dispersed in the cement paste. After the component is missing, the cementitious materials are prone to agglomeration: on the one hand, large-size gaps are formed between the agglomerates, the porosity of the cement stone increases, the impermeability decreases, and the erosion medium easily enters the interior; on the other hand, uneven dispersion leads to insufficient cement hydration reaction, a decrease in the amount of C-S-H gel generated and uneven distribution, and a hindered development of the compressive strength; meanwhile, the agglomerates are enriched near the aggregate interface, intensifying the pores in the interface transition zone, reducing the density of the concrete and affecting the erosion resistance; local shrinkage stress is easily generated in some areas due to excessive hydration, causing micro-cracks, and the dry shrinkage rate increases accordingly.

[0129] Comparative Example 11 (no polyethylene glycol-400 dilaurate is added in the functional additive): The polyethylene glycol-400 dilaurate is the “water-retaining-plasticizing synergistic component” in the functional additive, and its mechanism of action includes two points: first, as a water-retaining agent, the polyethylene glycol segment (hydrophilic) in the molecule forms a hydrogen bond with the free water in the cement paste, slowing down the evaporation rate of water, especially in the initial setting stage after the concrete is poured, to avoid the “surface dry shrinkage cracks” caused by the rapid loss of surface water; second, as a plasticizer, the lauric acid segment (hydrophobic) in the molecule is adsorbed on the surface of the cement particles, reducing the friction between the particles, improving the workability of the concrete, ensuring that the bubbles are fully discharged and the aggregate and cement paste are uniformly wrapped during the vibrating process, and reducing the internal pores caused by insufficient compaction. After the component is missing, the “water-retaining-density balance” of the concrete is broken, the insufficient water retention causes dry defects and the permeability decreases; the lack of plasticizing effect leads to insufficient density, the porosity of the interface transition zone increases, and a local loose structure is formed, resulting in a decrease in the compressive strength; the insufficient water retention leads to uneven distribution of water in the concrete, causing a freeze-thaw stress concentration point, and the cement stone around the bubbles is prone to cracking, resulting in an increase in the freeze-thaw mass loss rate.

[0130] Comparative Example 12 (functional additive component ratio change): The design logic of the ratio of the example is to "first ensure uniform dispersion, then strengthen waterproofing and water retention". The acrylic acid-itaconic acid copolymer has the highest proportion to ensure uniform dispersion of the cementitious material, providing a "uniform matrix" for the action of the waterproofing agent and water-retaining agent. The ratio of Comparative Example 12 breaks this logic. The core problem is "insufficient dispersion capacity, unable to support the action of excess waterproofing agent". The acrylic acid-itaconic acid copolymer has a low proportion, and the cementitious material will still agglomerate, forming a large number of gaps and local loose areas. Waterproofing substances form in local dense areas, and uncovered areas are still permeable channels, reducing the impermeability. Excess JRY-F concrete waterproofing agent will accelerate the hydration rate of cement, causing early hydration heat to be released in a concentrated manner, resulting in temperature stress in the interior of the concrete, which is prone to cause temperature cracks and hinder the development of compressive strength. Although the proportion of polyethylene glycol-400 dilaurate has increased slightly, due to the uneven dispersion of the cementitious material, the water-retaining effect cannot be uniformly exerted. In local areas, the water-retaining agent cannot contact the free water due to the obstruction of agglomerates, and the water will still evaporate quickly, forming dry cracks. In local areas, due to the excess of water-retaining agent, too much water is retained, and the water slowly dissipates during the late hardening of the concrete, which in turn leads to an increase in dry shrinkage.

[0131] Comparative Example 13 (all composite air entraining agents use liquid sodium abietate): The function of the composite air entraining agent relies on the "air entraining-stable bubble synergistic mechanism": sodium a-olefin sulfonate acts as an anionic surfactant, with the hydrophilic group (sodium sulfonate) in the molecular structure adsorbed on the cement paste-air interface and the hydrophobic group (alkenyl) facing the air, rapidly reducing the interfacial tension and thus efficiently introducing a large number of small bubbles. The role of liquid sodium abietate is "bubble stabilization", with the abietic acid structure in its molecule forming a tough adsorption film on the bubble surface, enhancing the mechanical strength of the bubble wall and preventing bubbles from merging into large bubbles or escaping during stirring and vibrating, ultimately forming a small-diameter and uniformly distributed bubble group. After changing to a single liquid sodium abietate, the air entraining capacity is insufficient, and it cannot quickly introduce sufficient bubbles. The appropriate amount of uniformly distributed small bubbles formed by the two can absorb the volume expansion stress caused by water freezing during freeze-thaw cycles, reducing structural damage. When the number of bubbles is insufficient and the diameter is large, the stress absorption capacity decreases, and the freeze-thaw mass loss rate increases. The small number of large bubbles in Comparative Example 13 have little effect on the overall porosity, and the impermeability grade and compressive strength change little, but due to the uneven distribution of bubbles, there are still permeable channels in local areas, and the chloride ion migration coefficient is slightly higher.

[0132] Comparative Example 14 (all the air entraining agent is α-alkenyl sulfonate sodium): the single α-alkenyl sulfonate sodium destroys the "air entraining-stable bubble balance", its air entraining capacity is strong, and a large amount of bubbles is quickly introduced, but it lacks the bubble stabilizing effect of liquid rosin acid sodium, the adsorption film formed by α-alkenyl sulfonate sodium on the bubble surface is thin and weak, and in the process of concrete mixing and vibrating, the bubbles are easy to collide and merge into large bubbles, or escape due to insufficient film strength, finally leading to "a large number of bubbles but uneven distribution and large size" in the concrete. In terms of frost resistance, the large bubbles not only cannot effectively absorb the frost heaving stress, but also become "containers" for water accumulation, and the water in the bubbles is easy to freeze and expand in the freeze-thaw cycle, which easily causes the surrounding cement stone to crack, so the freeze-thaw mass loss rate is higher than that of the example. Large-sized bubbles can significantly increase the connected porosity inside the concrete, increase the penetration channels, and large bubbles are equivalent to "internal defects", which can weaken the structural integrity of the concrete and reduce the compressive strength. In addition, after the bubbles escape, small pits are easy to form on the surface, which increases the water adsorption area and further increases the probability of invasion of chloride ions, sulfates and other erosion media.

[0133] Comparative Example 15 (the proportion of the composite air entraining agent is changed to liquid rosin acid sodium: α-alkenyl sulfonate sodium = 1:5): the design logic of the ratio of the example is "stability as the core, control air entraining efficiency", and the high proportion of liquid rosin acid sodium can ensure that the bubbles introduced by α-alkenyl sulfonate sodium exist stably and are uniformly distributed; and the ratio of Comparative Example 15 breaks this balance, and the bubble stability of liquid rosin acid sodium cannot match the high air entraining capacity of α-alkenyl sulfonate sodium, forming a "large bubble and small bubble" bubble structure, and the bubble distribution is relatively uneven, which affects the decline of various indicators.

Claims

1. An anti-erosion hydraulic concrete, characterized in that, The concrete comprises the following raw materials in parts by weight: 200-220 parts composite cement, 30-40 parts high-activity nano-modified metakaolin, 80-100 parts blast furnace slag powder, 70-80 parts low-calcium fly ash, 1050-1100 parts coarse aggregate, 650-700 parts natural river sand fine aggregate, 80-100 parts granite manufactured sand fine aggregate, 10-15 parts erosion inhibitor, 10-15 parts functional additives, 5-7 parts early-strength polycarboxylic acid high-performance water-reducing agent, 0.06-0.09 parts composite air-entraining agent, and 135-150 parts water; The composite cement is made of sulfoaluminate cement, silicate cement and polymer waterproof mortar in a mass ratio of 1:(1.4~1.6):(0.2~0.3); The highly active nano-modified metakaolin is obtained by drying metakaolin after modification with an organosilicon-ZnO composite emulsion; the organosilicon-ZnO composite emulsion is formulated with water, polyether-modified organosilicon emulsion, KH-570 silane coupling agent and nano ZnO. The coarse aggregate is composed of basalt crushed stone and granite crushed stone in a mass ratio of 1:(1~1.5); The corrosion inhibitor is composed of an organic carboxylate, a hydrophobic-crystallizing composite agent, and a pH-buffered corrosion inhibitor in a mass ratio of (1.0–1.5):(3.0–4.5):(1.7–2.4); the organic carboxylate is composed of sodium citrate and potassium tartrate in a mass ratio of (2–2.5):(1–1.2); the hydrophobic-crystallizing composite agent is composed of hydrophobic nano-silica and crystalline active component CaSiO3 in a mass ratio of 1:(1–1.5); the pH-buffered corrosion inhibitor is composed of sodium molybdate and cyclohexylamine in a mass ratio of (4–5):

1. The functional additive is composed of itaconic acid acrylic copolymer, JRY-F concrete waterproofing agent and polyethylene glycol-400 dilaurate in a mass ratio of 3:(1-1.5):(0.6-0.8). The composite air-entraining agent is made by mixing liquid sodium rosinate and sodium α-olefin sulfonate in a mass ratio of 5:(1 to 1.5).

2. The anti-erosion hydraulic concrete according to claim 1, characterized in that, The preparation method of the highly active nano-modified metakaolin includes: mixing metakaolin with organosilicon-ZnO composite emulsion evenly, drying, and air-jet pulverizing to a D50 of less than 3 μm to obtain highly active nano-modified metakaolin.

3. The anti-erosion hydraulic concrete according to claim 2, characterized in that, The metakaolin has a particle size that passes through a 650-800 mesh sieve; the amount of the organosilicon-ZnO composite emulsion is 15%-20% of the mass of the metakaolin; the organosilicon-ZnO composite emulsion is prepared by mixing water, polyether-modified organosilicon emulsion, KH-570 silane coupling agent, and nano-ZnO in a mass ratio of 10:(3-5):(0.5-0.8):(1.5-2), and adjusting the pH to 8.3-8.8; the solid content of the polyether-modified organosilicon emulsion is 60wt%-65wt%; and the drying temperature is 60℃-65℃.

4. The anti-erosion hydraulic concrete according to claim 1, characterized in that, The D50 of the blast furnace slag powder is below 10μm.

5. The anti-erosion hydraulic concrete according to claim 1, characterized in that, The low-calcium fly ash has a D50 of less than 50 μm and a CaO content of less than 5 wt%.

6. The anti-erosion hydraulic concrete according to claim 1, characterized in that, The continuous gradation of the coarse aggregate is as follows: 5mm ≤ particle size < 10mm accounts for 30wt% to 35wt%, 10 ≤ particle size < 18mm accounts for 35wt% to 40wt%, and 18 ≤ particle size < 25mm accounts for 25wt% to 30wt%.

7. The anti-erosion hydraulic concrete according to claim 1, characterized in that, The discontinuous gradation of the natural river sand fine aggregate is as follows: 35wt% to 40wt% of the 40-50 mesh range, 45wt% to 50wt% of the 60-80 mesh range, and 15wt% to 20wt% of the 100-120 mesh range.

8. The anti-erosion hydraulic concrete according to claim 1, characterized in that, The discontinuous gradation of the manufactured fine aggregate of the granite is as follows: 60wt% to 70wt% of the 50-mesh to 70-mesh range, and 30wt% to 40wt% of the 100-mesh to 150-mesh range.

9. The anti-erosion hydraulic concrete according to claim 1, characterized in that, The water specifications are: chloride ion content <200mg / L, sulfate ion content <600mg / L.

10. The method for preparing erosion-resistant hydraulic concrete according to claim 1, characterized in that, Includes the following steps: S1: Mix composite cement, blast furnace slag powder and low-calcium fly ash according to the mass fraction to obtain the mixture; S2: Mix coarse aggregate, natural river sand fine aggregate, and granite manufactured sand fine aggregate according to the mass fraction; then add 70wt%~80wt% water, early-strength polycarboxylic acid high-performance water-reducing agent and composite air-entraining agent, and mix; then add the mixture, highly active nano-modified metakaolin, erosion inhibitor and functional additives, and mix; finally add the remaining water, mix, and obtain concrete.

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