High-performance concrete material for precast pile processing and preparation method thereof

Abstract

The application discloses a kind of high-performance concrete materials and preparation method thereof for precast pile processing, belong to concrete preparation technical field, to solve in prior art, the technical problems that the mechanical properties and phosphate resistance of concrete need to be further improved;It is through the combination scheme of seed crystal microsphere surface modification, composite microsphere inorganic shell construction and basalt fiber functionalization, realize the overall improvement of material performance, seed crystal microsphere treated by silanization can be uniformly dispersed in matrix, induce dense precipitation of hydration product, improve interface transition zone structure;Composite microspheres with inorganic shell realize the controlled release of active substances during service, continuously repair and protect the defect site, basalt fiber modified by dopamine and covered by mineralization layer effectively enhance the interfacial adhesion and improve the corrosion resistance, the three form complementary synergistic effect, make material excellent in mechanical properties and corrosion resistance, significantly enhance overall bearing capacity and service life.

Description

Technical Field

[0001] This invention relates to the field of concrete preparation technology, specifically to a high-performance concrete material for precast pile processing and its preparation method. Background Technology

[0002] Precast piles are important load-bearing components in engineering foundations. The performance of concrete directly determines the structural safety and lifespan. Early ordinary concrete was insufficient in strength and toughness, and the pile body was prone to cracking under high loads, making it difficult to meet the needs of large-scale projects. With the development of high-performance concrete, through measures such as optimizing the water-cement ratio, introducing mineral admixtures and reinforcing fibers, the compressive strength, elastic modulus and crack resistance of the material have been significantly improved, enabling it to withstand higher loads and maintain stability.

[0003] Meanwhile, in coastal, saline soil, and chemical environments, sulfate erosion has become a key issue affecting the durability of precast piles. Traditional concrete is prone to expansion, spalling, and strength reduction. To address this issue, researchers have significantly improved the corrosion resistance and service life of materials by improving pore structure, increasing density, and adding sulfate-resistant active components. Overall, the continuous progress of high-performance concrete in mechanical properties and sulfate resistance provides a solid foundation for the long-term safe application of precast piles in complex environments.

[0004] While the concrete materials commonly used in conventional precast pile fabrication have improved in terms of strength and durability, certain limitations still exist: First, in pursuit of high compressive strength, ordinary high-strength concrete often has a low water-cement ratio, which leads to an increase in internal microcracks. Under high loads or uneven settlement of the foundation, the pile is prone to cracking, affecting the structural safety. Secondly, in highly corrosive environments such as coastal areas, saline soils, and chemical plants, the sulfate resistance of traditional concrete is still insufficient, making it prone to expansion, spalling, and strength reduction due to chemical erosion, thus shortening the service life of the pile. Secondly, some processes do not accurately control the proportion of mineral admixtures, making it difficult to effectively optimize the pore structure, resulting in insufficient material density and reduced long-term service performance. In addition, there is a contradiction between the workability and high strength of concrete during the production process, making it difficult to guarantee the compaction degree and easily leading to local defects.

[0005] The aforementioned problems are particularly prominent under complex geological and harsh environmental conditions, limiting the application of traditional processes in high-requirement engineering. Therefore, a solution is proposed. Summary of the Invention

[0006] The purpose of this invention is to provide a high-performance concrete material for precast pile processing and its preparation method, in order to solve the technical problem that the mechanical properties and phosphate resistance of concrete need to be further improved in the prior art.

[0007] The objective of this invention can be achieved through the following technical solution: a high-performance concrete material for precast pile processing, comprising the following raw material components by weight: 360-380 parts cement, 50-60 parts fly ash, 660-680 parts fine aggregate, 1100-1140 parts coarse aggregate, 120-150 parts mixing water, 16-18 parts modified seed crystal microspheres, 8-10 parts modified microcapsules, 6-8 parts modified mineralized fiber, and 4-6 parts polycarboxylate superplasticizer; The modified seed crystal microspheres are prepared as follows: anhydrous ethanol, deionized water and seed crystal microspheres are added to a reaction vessel and stirred. After the temperature of the reaction vessel is raised to 40-50℃, acetic acid is used to adjust the pH of the reaction system to 4-5. After stirring for 10-20 min, trimethyl[3-(trimethoxysilyl)propyl]ammonium chloride is added to the reaction vessel and stirred for 2-3 h. The modified seed crystal microspheres are obtained by post-treatment. The ratio of anhydrous ethanol, deionized water, seed crystal microspheres and trimethyl[3-(trimethoxysilyl)propyl]ammonium chloride is 8-10 mL: 2 mL: 1 g: 0.1 g.

[0008] The reaction principle for preparing seed crystal microspheres is as follows: Under suitable alcohol-water mixed solvent and weak acid conditions, the trimethoxysilyl group in trimethyl[3-(trimethoxysilyl)propyl]ammonium chloride undergoes a hydrolysis reaction to generate active -Si-OH groups. These -Si-OH groups can undergo a condensation reaction with the original -OH or Si-O groups on the surface of the seed crystal microspheres, thereby forming a stable Si-O-Si bonded layer on the surface of the inorganic microspheres. Meanwhile, the organic side chains with quaternary ammonium salt structures in the TMAPS molecules are retained on the surface of the material. In this way, the surface of the microspheres retains the stability of the silicon-oxygen network and introduces positively charged organic functional groups. Finally, through silanization condensation reaction, the silane coupling agent containing functional organic groups is firmly bonded to the surface of the seed crystal microspheres, so that it has both the nucleation characteristics of the inorganic phase and the interface regulation function of the organic phase, thereby obtaining modified seed crystal microspheres.

[0009] Further post-processing includes: after the reaction is completed, wait for the temperature of the reaction vessel to drop to room temperature, filter the reaction solution to collect the filter cake, wash the filter cake with anhydrous ethanol and deionized water until neutral, transfer the filter cake to a vacuum drying oven at 50°C, and vacuum dry it to constant weight to obtain modified seed crystal microspheres.

[0010] Furthermore, the preparation method of seed crystal microspheres includes the following steps: A1. Deionized water, anhydrous ethanol, and tetraethyl orthosilicate were added to a reaction vessel. The pH of the reaction system was adjusted to 2-3 using 1 mol / L hydrochloric acid aqueous solution and stirred at room temperature for 60-80 min. Aluminum nitrate solution was then added dropwise to the reaction vessel over 25-30 min. After the addition was completed, the mixture was stirred at room temperature for 60 min. The pH of the reaction system was then adjusted to 7.5 using 1 mol / L ammonia aqueous solution. The mixture was allowed to stand for 12 h for aging, and then post-processed to obtain microgels. A2. After ball milling and mixing the microgel and lithium carbonate, a mixed powder is obtained. The mixed powder is then calcined to obtain seed crystal microbeads.

[0011] The reaction principle for preparing seed crystal microspheres is as follows: A three-dimensional network structure with -Si-O-Si- as the framework is gradually constructed by hydrolysis and condensation reaction of silicon source under acidic environment. In this process, aluminum ions introduced can replace some silicon sites and embed into the silicon-oxygen network to form a stable Si-O-Al framework structure. This structure is further condensed and aged under subsequent neutral conditions to obtain microgels with high dispersibility and reactivity. Before heat treatment, lithium source was introduced into the microgel system by ball milling. As the temperature rises, lithium salt decomposes and releases active Li2O, which reacts with the Si-O-Al network in the microgel in a solid phase reaction and gradually transforms into lithium-containing silicate or aluminosilicate crystal phase. In this process, the gel framework not only provides a uniform molecular-level mixing environment, but also effectively reduces the activation energy required for crystallization, making the nucleation process more uniform and controllable. Ultimately, through controlled heating and holding, orderly crystallization and sintering occur in the system, generating seed crystal microbeads with dense structure, uniform composition, and stable crystal nuclei. These microbeads have an excellent "seed crystal" effect because they already have an active phase inside that can serve as the starting point for crystal growth. This can significantly accelerate the nucleation rate and improve the grain morphology in subsequent material synthesis.

[0012] Further, in step A1, the ratio of deionized water, anhydrous ethanol, tetraethyl orthosilicate, and aluminum nitrate solution is 3.0 mL:1.5 mL:1.0-1.2 g:1.0 mL. The aluminum nitrate solution is obtained by mixing aluminum nitrate nonahydrate and deionized water at a ratio of 0.38-0.40 g:1.0 mL. The post-treatment includes: after the reaction is completed, the temperature of the reaction vessel is lowered to room temperature, the reaction solution is filtered to collect the filter cake, the filter cake is washed with anhydrous ethanol and deionized water until neutral, and then the filter cake is transferred to a vacuum drying oven at 50°C and vacuum dried to constant weight to obtain microgels. Furthermore, in step A2, the ratio of microgel to lithium carbonate is 1.0g:1.1-1.2g; Further, the ball milling operation is as follows: Microgel and lithium carbonate are added to a planetary ball mill, using zirconium balls with a particle size of 3 mm and controlling the ball-to-material ratio at 10-12:1. The rotation speed is set to 280-320 rpm, and ball milling is performed at a cycle of 10 minutes of milling followed by 5 minutes of rest, until the sampled powder D is obtained. 50 =5μm; Further, the calcination operation is as follows: the mixed powder is transferred to a muffle furnace, heated to 300°C at a heating rate of 2°C / min under an air atmosphere, held for 30 min, then heated to 550°C at a heating rate of 2°C / min, held for 30 min, then heated to 700°C at a heating rate of 3°C / min, held for 2 h, and then naturally cooled to room temperature to obtain seed crystal microspheres.

[0013] Furthermore, the preparation method of the modified microcapsules includes the following steps: B1. Acrylamide, sodium acrylate, N,N′-methylenebisacrylamide, L-calcium lactate pentahydrate and Tris buffer were added to a reaction vessel with an ice bath temperature of 10-15℃ and stirred. After adding ammonium persulfate and N,N,N',N'-tetramethylethylenediamine to the reaction vessel, the reaction solution was quickly transferred to a high-speed shear machine and emulsified at 4000 rpm for 5 min. Then, the temperature of the high-speed shear machine was raised to 40-50℃ and kept at that temperature for 2-3 h. The post-processing yielded elastic microspheres. B2. Add the elastic microspheres and saturated calcium hydroxide aqueous solution to the reaction vessel and stir. Then, add tetraethyl orthosilicate dispersion dropwise to the reaction vessel at room temperature. After the dropwise addition is completed within 50-60 minutes, stir for 2-3 hours. The composite microspheres are then obtained through post-treatment. B3. Add the composite microspheres, deionized water, ethylene glycol and sodium bicarbonate to the reaction vessel and stir. After purging with nitrogen, lower the temperature of the reaction vessel to 3-5℃ and add the organic phase dropwise to the reaction vessel. After the addition is completed within 45-60 minutes, keep the temperature and stir for 15-20 minutes. After stirring, let it stand for 10 minutes and then process to obtain the modified microcapsules.

[0014] The reaction principle for preparing modified microcapsules is as follows: Acrylamide and sodium acrylate undergo free radical polymerization under the combined action of ammonium persulfate initiator and N,N,N′,N′-tetramethylethylenediamine accelerator. N,N′-methylenebisacrylamide acts as a crosslinking agent to introduce a three-dimensional network structure, forming elastic microspheres with a certain degree of elasticity. Among them, L-calcium lactate pentahydrate acts as a complexing agent to regulate the network porosity in the reaction and provides Ca²⁺ binding sites for subsequent silicon source deposition. Saturated calcium hydroxide solution provides an alkaline environment that promotes the hydrolysis and condensation reaction of tetraethyl orthosilicate, generating a Si-O-Si network that deposits on the surface of elastic microspheres. 2+The interaction with silicate ions forms a composite microsphere of "organic polymer framework + silicate inorganic shell", which significantly improves the stability and mechanical strength of the particles. The composite microspheres maintain a weakly alkaline environment in the presence of sodium bicarbonate. Under low temperature and nitrogen protection, a sebacate chloride / n-hexane organic phase is introduced into the system. The sebacate chloride undergoes an interfacial condensation reaction with the residual hydroxyl and carboxyl groups on the surface of the microspheres to form a dense aliphatic amide or esterified cross-linked layer. Finally, an organic shell wall is constructed on the outside of the microspheres. This shell wall endows the particles with excellent dispersibility and interfacial compatibility, and can also serve as a protective layer and sustained-release layer for the carrier, resulting in modified microcapsules with complete structure and stable interface.

[0015] Further, in step B1, the ratio of acrylamide, sodium acrylate, N,N′-methylenebisacrylamide, L-calcium lactate pentahydrate, Tris buffer, ammonium persulfate, and N,N,N',N'-tetramethylethylenediamine is 180-200g:400g:2g:80-100g:2800-3000mL:2.5g:2.0mL, wherein the pH of the Tris buffer is 8.5 and the concentration is 0.05mol / L. The post-treatment includes: after the reaction is completed, the temperature of the reaction vessel is lowered to room temperature, the reaction solution is filtered to collect the filter cake, the filter cake is washed with anhydrous ethanol and deionized water until neutral, and the filter cake is transferred to a vacuum drying oven at 50°C and vacuum dried to constant weight to obtain elastic microspheres; Further, in step B2, the ratio of elastic microspheres, saturated calcium hydroxide aqueous solution, and tetraethyl orthosilicate dispersion is 50g:120-150mL:50mL. The tetraethyl orthosilicate dispersion is obtained by mixing tetraethyl orthosilicate and anhydrous ethanol at a ratio of 6g:25mL. The post-treatment includes: after the reaction is completed, the temperature of the reaction vessel is lowered to room temperature, the reaction solution is filtered to collect the filter cake, the filter cake is washed with anhydrous ethanol and deionized water until neutral, and then the filter cake is transferred to a vacuum drying oven at 50°C and vacuum dried to constant weight to obtain composite microspheres. Further, in step B3, the ratio of composite microspheres, deionized water, ethylene glycol, sodium bicarbonate, and organic phase is 50g:100-120mL:0.3g:0.1g:60mL. The organic phase is obtained by mixing sebacate chloride and n-hexane in a ratio of 1g:10mL. The post-treatment includes: after the reaction is completed, the temperature of the reaction vessel is lowered to room temperature, the reaction solution is filtered to collect the filter cake, the filter cake is washed with anhydrous ethanol and deionized water until neutral, and then the filter cake is transferred to a vacuum drying oven at 50°C and vacuum dried to constant weight to obtain modified microcapsules.

[0016] Furthermore, the preparation method of modified mineralized fibers includes the following steps: C1. Basalt fiber and Tris-HCl buffer solution at pH=8.5 were added to the reactor and stirred. Dopamine hydrochloride was added to the reactor at room temperature and stirring was continued for 2-3 hours. The post-treatment yielded polydopamine modified fiber. C2. Add polydopamine-modified fibers and saturated calcium hydroxide aqueous solution to a reaction vessel, stir at room temperature for 1-2 hours, and then add water glass dispersion to the reaction vessel at room temperature. After the addition is completed within 20-30 minutes, stir for 2-3 hours. The modified mineralized fibers are then obtained through post-treatment.

[0017] The reaction principle for preparing modified mineralized fibers is as follows: In a weakly alkaline Tris-HCl buffer environment, dopamine hydrochloride undergoes an auto-oxidation-polymerization reaction to form a dense polydopamine coating rich in active functional groups on the surface of basalt fibers, resulting in polydopamine-modified fibers. This coating not only enhances the hydrophilicity and interfacial activity of the fiber surface, but also provides abundant complexation sites, facilitating the subsequent binding and deposition of calcium ions and silicate ions.

[0018] Polydopamine-modified fibers adsorb and enrich Ca in saturated calcium hydroxide solution 2+ Subsequently, water glass hydrolyzes in an alkaline environment to generate silicate ions, which react with Ca on the fiber surface. 2+ A deposition reaction occurs, forming a Ca-Si phase mineralization layer. This mineralization layer uniformly covers the polydopamine coating, realizing an organic-inorganic composite interface structure, and obtaining modified mineralized fibers. The resulting modified mineralized fiber combines the surface activity of polydopamine with the mineralization properties of inorganic calcium silicate layers, which not only significantly improves the interfacial bonding between the fiber and the cement matrix, but also endows it with excellent mechanical reinforcement and durability improvement.

[0019] Further, in step C1, the ratio of basalt fiber, pH=8.5 Tris-HCl buffer solution, and dopamine hydrochloride is 1g:5-6mL:0.05-0.06g. The post-treatment includes: after the reaction is completed, wait for the temperature of the reaction vessel to drop to room temperature, filter the reaction solution to collect the filter cake, wash the filter cake with anhydrous ethanol and deionized water until neutral, transfer the filter cake to a vacuum drying oven at 50℃, and vacuum dry it to constant weight to obtain polydopamine modified fiber; Further, in step C2, the ratio of polydopamine modified fiber, saturated calcium hydroxide aqueous solution and water glass dispersion is 1g:5-6mL:4mL. The water glass dispersion is obtained by mixing water glass and deionized water in a ratio of 1mL:1mL. The post-treatment includes: after the reaction is completed, wait for the temperature of the reaction vessel to drop to room temperature, filter the reaction solution to collect the filter cake, wash the filter cake with anhydrous ethanol and deionized water until neutral, transfer the filter cake to a vacuum drying oven at 50°C, and vacuum dry it to constant weight to obtain modified mineralized fiber.

[0020] This invention also proposes a method for preparing high-performance concrete material for precast pile processing. Fine and coarse aggregates are added to a mixing tank and dry-mixed for 8-10 seconds. Cement and fly ash are then added and dry-mixed for 10-15 seconds. Next, 70% mixing water and modified seed crystal microspheres are added and mixed for 60-90 seconds. Then, 30% mixing water and polycarboxylate superplasticizer are added and mixed for 10-15 seconds. Modified mineralized fibers are then added and mixed for 30-45 seconds. Finally, modified microcapsules are added and mixed for 20-30 seconds. The mixture is then cured to obtain high-performance concrete.

[0021] The reaction principle for preparing modified mineralized fibers is as follows: During the hydration and pozzolanic reaction of the cement matrix, modified seed crystal microspheres act as heterogeneous nucleation cores, inducing and regulating the nucleation and growth of hydration products, thus altering the crystal formation pathway; the modified mineralized fibers react with Ca in an alkaline system. 2+ SiO3 2- A deposition reaction occurs, and a stable mineralized layer gradually forms on its surface, thus participating in the construction of the interface structure. Modified microcapsules release active components during hydration and curing, reacting chemically and physically with cement hydration ions and products, regulating the pore structure and interface environment. Through a continuous reaction process of "nucleation-mineralization-release", the three types of materials are coupled with the cement-based system to jointly achieve the formation of high-performance concrete.

[0022] Further, the curing process is as follows: After mixing, the material is transferred to a mold and left to stand for 2-3 hours. Then, the temperature is increased to 55-60℃ at a rate of 10-15℃ / h, and left to stand at a constant temperature for 6-8 hours. Finally, the temperature is reduced to 20-30℃ at a rate of 8-10℃ / h, and the material is demolded to obtain high-performance concrete.

[0023] The present invention has the following beneficial effects: The modified seed crystal microspheres prepared by this invention are uniformly dispersed during cement hydration, effectively promoting the generation and deposition of hydration products as nucleation centers, making the matrix structure denser and enhancing compressive bearing capacity. The modified mineralized fibers not only play a physical bridging role in the slurry, but also form a strong interface with the cement matrix through their surface active layer, effectively blocking and deflecting the development of microcracks under external forces, thereby significantly improving the flexural and splitting tensile strength of concrete. At the same time, the modified microcapsules continuously release active ingredients during the hardening process, further optimizing the microporous structure, reducing interface defects, and making stress transmission more uniform. The three elements form a composite toughening mechanism of "matrix densification-interface enhancement-crack control", which not only improves the individual mechanical properties of the material, but also achieves a balanced and coordinated improvement in overall mechanical properties.

[0024] The seed crystal microspheres prepared by this invention are uniformly distributed in the matrix, which not only makes the hydration products more compact, but also significantly improves the surface hardness and density, reducing the incidence of surface wear from the source. The modified mineralized fibers play an "anti-tensile" role during the wear process. They can tightly bind the surface micro-region structure and prevent particles from peeling off due to friction and impact, thereby effectively delaying the surface roughening and abrasive particle shedding. At the same time, the modified microcapsules gradually release active ingredients under long-term service conditions, which play a secondary filling and lubrication role on the matrix and fiber interface. On the one hand, they repair minor defects, and on the other hand, they reduce the coefficient of friction, significantly improving the durability of the material under dry friction and impact friction environments. The synergistic effect of the three makes the material exhibit superior characteristics of low wear rate, high surface integrity and long service life under repeated friction, particle impact and long-term wear conditions.

[0025] The modified seed crystal microspheres prepared by this invention provide uniform nucleation sites in the early stage of hydration, resulting in a finer distribution of the generated hydration products and a significant reduction in porosity, thereby effectively blocking the penetration channels of sulfate ions. Secondly, the modified mineralized fibers form a spatial skeleton in the matrix, which not only improves the overall toughness but also enhances the interfacial sealing by combining with the hydration products through their surface active groups, further weakening the erosion and damage of the interface by sulfate. Thirdly, the modified microcapsules gradually release functional components under long-term service conditions, which play a secondary filling and passivation role for microcracks and local pores, inhibiting the opportunity for sulfate ions to enter and react with hydrates. Finally, through the synergy of the three, a corrosion resistance mechanism of "dense barrier-interface reinforcement-self-healing passivation" is formed, which effectively reduces the common problems of expansion, cracking and erosion after sulfate intrusion. Detailed Implementation

[0026] The technical solution of the present invention will be clearly and completely described below with reference to the embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0027] The basalt fiber used in this invention was purchased from Jiangsu Jumao New Material Technology Co., Ltd.; the coarse aggregate used was 4.5mm construction crushed stone; the fine aggregate used was natural river sand obtained by passing through a 50-mesh sieve; the cement used was purchased from Jiaozuo Qianye Cement Co., Ltd., model P.O42.5 silicate cement; the fly ash used was purchased from Wuhan Jiyesheng Chemical Co., Ltd., item number A01085; and the polycarboxylate superplasticizer used was purchased from Guangdong Wengjiang Chemical Reagent Co., Ltd., item number PA96208. Example

[0028] This embodiment provides a method for preparing modified seed crystal microspheres for the preparation of high-performance concrete materials for precast pile processing, including the following steps: Step ①: Preparation of microgels Weigh out 38.0 g of aluminum nitrate nonahydrate and mix it with 100.0 mL of deionized water to obtain an aluminum nitrate solution; Weigh out 300.0 mL of deionized water, 150.0 mL of anhydrous ethanol, and 100.0 g of tetraethyl orthosilicate and add them to the reaction vessel. Adjust the pH of the reaction system to 2 using 1 mol / L hydrochloric acid aqueous solution and stir at room temperature for 60 min. Then, add 100.0 mL of aluminum nitrate solution dropwise to the reaction vessel over 25 min. After the addition is complete, stir at room temperature for 60 min. Adjust the pH of the reaction system to 7.5 using 1 mol / L ammonia aqueous solution and allow it to stand for 12 h. After the reaction is complete, wait for the temperature of the reaction vessel to drop to room temperature, filter the reaction solution and collect the filter cake. Wash the filter cake with anhydrous ethanol and deionized water until neutral, then transfer the filter cake to a vacuum drying oven at 50 °C and vacuum dry to constant weight to obtain microgels.

[0029] Step ②: Preparation of seed crystal microbeads Weigh out 100.0g of microgel and 110.0g of lithium carbonate and add them to a planetary ball mill. Use zirconium balls with a particle size of 3mm and control the ball-to-material ratio at 10:1. Set the speed to 280rpm and ball mill at a program of 10min milling / 5min stop until the powder D obtained is sampled. 50 =5μm, to obtain mixed powder; Weigh 200.0g of the mixed powder and transfer it to a muffle furnace. Under an air atmosphere, heat the powder to 300℃ at a heating rate of 2℃ / min, hold for 30min, then continue heating to 550℃ at a heating rate of 2℃ / min, hold for 30min, then heat to 700℃ at a heating rate of 3℃ / min, hold for 2h, and then allow it to cool naturally to room temperature to obtain seed crystal microspheres.

[0030] Step 3: Preparation of modified seed crystal microbeads Weigh out 800.0 mL of anhydrous ethanol, 200.0 mL of deionized water, and 100.0 g of seed crystal microbeads and add them to the reaction vessel. Stir the mixture. After the temperature of the reaction vessel is raised to 40℃, adjust the pH of the reaction system to 4 with acetic acid. After stirring for 10 min, add 10.0 g of trimethyl[3-(trimethoxysilyl)propyl]ammonium chloride to the reaction vessel and stir for 2 h. After the reaction is completed, wait for the temperature of the reaction vessel to drop to room temperature, filter the reaction solution and collect the filter cake. Wash the filter cake with anhydrous ethanol and deionized water until neutral, and then transfer the filter cake to a vacuum drying oven at 50℃. Vacuum dry to constant weight to obtain modified seed crystal microbeads. Example

[0031] This embodiment provides a method for preparing modified seed crystal microspheres for the preparation of high-performance concrete materials for precast pile processing, including the following steps: Step ①: Preparation of microgels Weigh out 40.0 g of aluminum nitrate nonahydrate and mix it with 100.0 mL of deionized water to obtain an aluminum nitrate solution; Weigh out 300.0 mL of deionized water, 150.0 mL of anhydrous ethanol, and 120.0 g of tetraethyl orthosilicate and add them to the reaction vessel. Adjust the pH of the reaction system to 3 using 1 mol / L hydrochloric acid aqueous solution and stir at room temperature for 80 min. Then, add 100.0 mL of aluminum nitrate solution dropwise to the reaction vessel over 30 min. After the addition is complete, stir at room temperature for 60 min. Adjust the pH of the reaction system to 7.5 using 1 mol / L ammonia aqueous solution and allow it to stand for 12 h. After the reaction is complete, wait for the temperature of the reaction vessel to drop to room temperature, filter the reaction solution and collect the filter cake. Wash the filter cake with anhydrous ethanol and deionized water until neutral, then transfer the filter cake to a vacuum drying oven at 50 °C and vacuum dry to constant weight to obtain microgels.

[0032] Step ②: Preparation of seed crystal microbeads Weigh out 100.0g of microgel and 120.0g of lithium carbonate and add them to a planetary ball mill. Use zirconium balls with a particle size of 3mm and control the ball-to-material ratio at 12:1. Set the speed to 320rpm and ball mill at a program of 10min milling / 5min stop until the powder D obtained is sampled. 50 =5μm, to obtain mixed powder; Weigh 200.0g of the mixed powder and transfer it to a muffle furnace. Under an air atmosphere, heat the powder to 300℃ at a heating rate of 2℃ / min, hold for 30min, then continue heating to 550℃ at a heating rate of 2℃ / min, hold for 30min, then heat to 700℃ at a heating rate of 3℃ / min, hold for 2h, and then allow it to cool naturally to room temperature to obtain seed crystal microspheres.

[0033] Step 3: Preparation of modified seed crystal microbeads Weigh out 1000.0 mL of anhydrous ethanol, 200.0 mL of deionized water, and 100.0 g of seed crystal microspheres and add them to the reaction vessel. Stir the mixture. After the temperature of the reaction vessel is raised to 50℃, adjust the pH of the reaction system to 5 with acetic acid. After stirring for 20 min, add 10.0 g of trimethyl[3-(trimethoxysilyl)propyl]ammonium chloride to the reaction vessel and stir for 3 h. After the reaction is completed, wait for the temperature of the reaction vessel to drop to room temperature, filter the reaction solution and collect the filter cake. Wash the filter cake with anhydrous ethanol and deionized water until neutral, and then transfer the filter cake to a vacuum drying oven at 50℃. Vacuum dry to constant weight to obtain modified seed crystal microspheres. Example

[0034] This embodiment provides a method for preparing modified seed crystal microspheres for the preparation of high-performance concrete materials for precast pile processing, including the following steps: Step ①: Preparation of microgels Weigh out 40.0 g of aluminum nitrate nonahydrate and mix it with 100.0 mL of deionized water to obtain an aluminum nitrate solution; Weigh out 300.0 mL of deionized water, 150.0 mL of anhydrous ethanol, and 120.0 g of tetraethyl orthosilicate and add them to the reaction vessel. Adjust the pH of the reaction system to 3 using 1 mol / L hydrochloric acid aqueous solution and stir at room temperature for 70 min. Then, add 100.0 mL of aluminum nitrate solution dropwise to the reaction vessel over 27 min. After the addition is complete, stir at room temperature for 60 min. Adjust the pH of the reaction system to 7.5 using 1 mol / L ammonia aqueous solution and allow it to stand for 12 h. After the reaction is complete, wait for the temperature of the reaction vessel to drop to room temperature, filter the reaction solution and collect the filter cake. Wash the filter cake with anhydrous ethanol and deionized water until neutral, then transfer the filter cake to a vacuum drying oven at 50 °C and vacuum dry to constant weight to obtain microgels.

[0035] Step ②: Preparation of seed crystal microbeads Weigh out 100.0g of microgel and 120.0g of lithium carbonate and add them to a planetary ball mill. Use zirconium balls with a particle size of 3mm and control the ball-to-material ratio at 12:1. Set the speed to 300rpm and ball mill at a program of 10min milling / 5min stop until the powder D obtained is sampled. 50 =5μm, to obtain mixed powder; Weigh 200.0g of the mixed powder and transfer it to a muffle furnace. Under an air atmosphere, heat the powder to 300℃ at a heating rate of 2℃ / min, hold for 30min, then continue heating to 550℃ at a heating rate of 2℃ / min, hold for 30min, then heat to 700℃ at a heating rate of 3℃ / min, hold for 2h, and then allow it to cool naturally to room temperature to obtain seed crystal microspheres.

[0036] Step 3: Preparation of modified seed crystal microbeads Weigh out 900.0 mL of anhydrous ethanol, 200.0 mL of deionized water, and 100.0 g of seed crystal microspheres and add them to the reaction vessel. Stir the mixture and raise the temperature of the reaction vessel to 45°C. Adjust the pH of the reaction system to 4 using acetic acid. After stirring for 16 min, add 10.0 g of trimethyl[3-(trimethoxysilyl)propyl]ammonium chloride to the reaction vessel and stir for 2 h. After the reaction is complete, wait for the temperature of the reaction vessel to drop to room temperature, filter the reaction solution and collect the filter cake. Wash the filter cake with anhydrous ethanol and deionized water until neutral. Transfer the filter cake to a vacuum drying oven at 50°C and vacuum dry it to constant weight to obtain modified seed crystal microspheres. Example

[0037] This embodiment provides a method for preparing modified microcapsules for the preparation of high-performance concrete materials for precast pile processing, including the following steps: Step I: Preparation of elastic microspheres Weigh out 180.0g acrylamide, 400.0g sodium acrylate, 2.0g N,N′-methylenebisacrylamide, 80.0g L-calcium lactate pentahydrate, and 2800.0mL of 0.05mol / L Tris buffer solution (pH=8.5) and add them to a reaction vessel at an ice bath temperature of 10℃. Stir the mixture and add 2.5g ammonium persulfate and 2.0mL N,N,N',N'-tetramethylethylenediamine to the reaction vessel. Immediately transfer the reaction solution to a high-speed shear press and emulsify at 4000rpm for 5min. Then, raise the temperature of the high-speed shear press to 40℃ and keep it at that temperature for 2h. After the reaction is complete, wait for the temperature of the reaction vessel to drop to room temperature, filter the reaction solution and collect the filter cake. Wash the filter cake with anhydrous ethanol and deionized water until neutral, and then transfer the filter cake to a vacuum drying oven at 50℃ and vacuum dry it to constant weight to obtain elastic microspheres.

[0038] Step II: Preparation of composite microspheres Weigh out 12.0 g of tetraethyl orthosilicate and mix it with 50.0 mL of anhydrous ethanol to obtain a tetraethyl orthosilicate dispersion; Weigh 50.0 g of elastic microspheres and 120.0 mL of saturated calcium hydroxide aqueous solution and add them to the reaction vessel and stir. Then, add 50.0 mL of tetraethyl orthosilicate dispersion dropwise to the reaction vessel at room temperature for 50 min. After the addition is completed, stir for 2 h. After the reaction is completed, wait for the temperature of the reaction vessel to drop to room temperature, filter the reaction solution and collect the filter cake. Wash the filter cake with anhydrous ethanol and deionized water until neutral, and then transfer the filter cake to a vacuum drying oven at 50 °C and vacuum dry to constant weight to obtain composite microspheres.

[0039] Step III: Preparation of modified microcapsules Weigh out 10.0 g of sebacate chloride and mix it with 60.0 mL of n-hexane to obtain the organic phase. Weigh out 50.0 g of composite microspheres, 120.0 mL of deionized water, 0.3 g of ethylene glycol, and 0.1 g of sodium bicarbonate and add them to the reaction vessel. Stir the mixture and purge with nitrogen to lower the temperature of the reaction vessel to 3 °C. Then, add 60.0 mL of organic phase dropwise to the reaction vessel over a period of 45 min. After the addition is complete, keep the mixture warm and stir for 15 min. After stirring, let the mixture stand for 10 min. Once the reaction is complete, allow the temperature of the reaction vessel to drop to room temperature. Filter the reaction mixture and collect the filter cake. Wash the filter cake with anhydrous ethanol and deionized water until neutral. Transfer the filter cake to a vacuum drying oven at 50 °C and vacuum dry it to constant weight to obtain the modified microcapsules. Example

[0040] This embodiment provides a method for preparing modified microcapsules for the preparation of high-performance concrete materials for precast pile processing, including the following steps: Step I: Preparation of elastic microspheres Weigh out 200.0g acrylamide, 400.0g sodium acrylate, 2.0g N,N′-methylenebisacrylamide, 100.0g L-calcium lactate pentahydrate, and 3000.0mL of Tris buffer solution with pH=8.5 and a concentration of 0.05mol / L. Add these to a reaction vessel with an ice bath temperature of 15℃ and stir. Then add 2.5g ammonium persulfate and 2.0mL N,N,N',N'-tetramethylethylenediamine to the reaction vessel. Quickly transfer the reaction solution to a high-speed shear press and emulsify at 4000rpm for 5min. Then raise the temperature of the high-speed shear press to 50℃ and keep it at that temperature for 2-3h. After the reaction is complete, wait for the temperature of the reaction vessel to drop to room temperature, filter the reaction solution and collect the filter cake. Wash the filter cake with anhydrous ethanol and deionized water until neutral, then transfer the filter cake to a vacuum drying oven at 50℃ and vacuum dry to constant weight to obtain elastic microspheres.

[0041] Step II: Preparation of composite microspheres Weigh out 12.0 g of tetraethyl orthosilicate and mix it with 50.0 mL of anhydrous ethanol to obtain a tetraethyl orthosilicate dispersion; Weigh 50.0 g of elastic microspheres and 150.0 mL of saturated calcium hydroxide aqueous solution and add them to the reaction vessel and stir. Then, add 50.0 mL of tetraethyl orthosilicate dispersion dropwise to the reaction vessel at room temperature for 60 min. After the addition is completed, stir for 3 h. After the reaction is completed, wait for the temperature of the reaction vessel to drop to room temperature, filter the reaction solution and collect the filter cake. Wash the filter cake with anhydrous ethanol and deionized water until neutral, and then transfer the filter cake to a vacuum drying oven at 50 °C and vacuum dry to constant weight to obtain composite microspheres.

[0042] Step III: Preparation of modified microcapsules Weigh out 10.0 g of sebacate chloride and mix it with 60.0 mL of n-hexane to obtain the organic phase. Weigh out 50.0 g of composite microspheres, 120.0 mL of deionized water, 0.3 g of ethylene glycol, and 0.1 g of sodium bicarbonate and add them to the reaction vessel. Stir the mixture and purge with nitrogen to lower the temperature of the reaction vessel to 5 °C. Then, add 60.0 mL of organic phase dropwise to the reaction vessel over a period of 60 min. After the addition is complete, keep the mixture warm and stir for 20 min. After stirring, let it stand for 10 min. After the reaction is complete, wait for the temperature of the reaction vessel to drop to room temperature. Filter the reaction solution and collect the filter cake. Wash the filter cake with anhydrous ethanol and deionized water until neutral. Transfer the filter cake to a vacuum drying oven at 50 °C and vacuum dry it to constant weight to obtain the modified microcapsules. Example

[0043] This embodiment provides a method for preparing modified microcapsules for the preparation of high-performance concrete materials for precast pile processing, including the following steps: Step I: Preparation of elastic microspheres Weigh out 200.0g acrylamide, 400.0g sodium acrylate, 2.0g N,N′-methylenebisacrylamide, 96.0g L-calcium lactate pentahydrate, and 3000.0mL of 0.05mol / L Tris buffer solution (pH=8.5). Add these to a reaction vessel at 12℃ (ice bath) and stir. Then add 2.5g ammonium persulfate and 2.0mL N,N,N',N'-tetramethylethylenediamine to the reaction vessel. Quickly transfer the reaction solution to a high-speed shear press and emulsify at 4000rpm for 5min. Increase the temperature of the high-speed shear press to 50℃ and maintain the temperature for 3h. After the reaction is complete, wait for the reaction vessel temperature to drop to room temperature, filter the reaction solution, collect the filter cake, wash the filter cake with anhydrous ethanol and deionized water until neutral, and then transfer the filter cake to a vacuum drying oven at 50℃. Vacuum dry to constant weight to obtain elastic microspheres.

[0044] Step II: Preparation of composite microspheres Weigh out 12.0 g of tetraethyl orthosilicate and mix it with 50.0 mL of anhydrous ethanol to obtain a tetraethyl orthosilicate dispersion; Weigh 50.0 g of elastic microspheres and 150.0 mL of saturated calcium hydroxide aqueous solution and add them to the reaction vessel. Stir the mixture and add 50.0 mL of tetraethyl orthosilicate dispersion dropwise to the reaction vessel at room temperature. After the addition is completed in 54 min, stir for 2-3 h. After the reaction is completed, wait for the temperature of the reaction vessel to drop to room temperature, filter the reaction solution and collect the filter cake. Wash the filter cake with anhydrous ethanol and deionized water until neutral, and then transfer the filter cake to a vacuum drying oven at 50 °C. Vacuum dry to constant weight to obtain composite microspheres.

[0045] Step III: Preparation of modified microcapsules Weigh out 10.0 g of sebacate chloride and mix it with 60.0 mL of n-hexane to obtain the organic phase. Weigh out 50.0 g of composite microspheres, 120.0 mL of deionized water, 0.3 g of ethylene glycol, and 0.1 g of sodium bicarbonate and add them to the reaction vessel. Stir the mixture and purge with nitrogen to protect it. Then, lower the temperature of the reaction vessel to 5 °C and add 60.0 mL of organic phase dropwise to the reaction vessel. Continue adding the organic phase dropwise for 50 min. After the addition is complete, keep the mixture warm and stir for 18 min. After stirring, let it stand for 10 min. After the reaction is complete, wait for the temperature of the reaction vessel to drop to room temperature, filter the reaction solution and collect the filter cake. Wash the filter cake with anhydrous ethanol and deionized water until neutral. Transfer the filter cake to a vacuum drying oven at 50 °C and vacuum dry it to constant weight to obtain modified microcapsules. Example

[0046] This embodiment provides a method for preparing high-performance concrete material for precast pile processing, including the following steps: Step 1: Preparation of polydopamine-modified fibers Weigh 10.0g of basalt fiber and 50.0mL of Tris-HCl buffer solution (pH=8.5) and add them to the reaction vessel. Stir and add 0.5g of dopamine hydrochloride to the reaction vessel at room temperature. Continue stirring for 2 hours. After the reaction is complete, wait for the temperature of the reaction vessel to drop to room temperature, filter the reaction solution and collect the filter cake. Wash the filter cake with anhydrous ethanol and deionized water until neutral. Transfer the filter cake to a vacuum drying oven at 50℃ and vacuum dry it to constant weight to obtain polydopamine modified fiber.

[0047] Step 2: Preparation of modified mineralized fibers Weigh out 20.0 mL of water glass and 20.0 mL of deionized water and mix them to obtain a water glass dispersion; Weigh 10.0g of polydopamine modified fiber and 50.0mL of saturated calcium hydroxide aqueous solution and add them to the reactor. Stir at room temperature for 1h, and then add 40.0mL of water glass dispersion to the reactor at room temperature. After the addition is completed in 20min, stir for 2h. The modified mineralized fiber is then obtained after post-treatment.

[0048] Step 3: Preparation of high-performance concrete By weight, 660 parts of fine aggregate and 1100 parts of coarse aggregate were weighed and added to the mixing tank. After dry mixing for 8 seconds, 360 parts of cement and 50 parts of fly ash were added and dry mixed for 10 seconds. Then, 84 parts of mixing water and 16 parts of the modified seed crystal microspheres prepared in Example 1 were added and stirred for 60 seconds. Next, 36 parts of mixing water and 4 parts of polycarboxylate superplasticizer were added and stirred for 10 seconds. Then, 6 parts of modified mineralized fiber were added and stirred for 30 seconds. Finally, 8 parts of the modified microcapsules prepared in Example 4 were added and stirred for 20 seconds. The material was then transferred to a mold and allowed to stand for 2 hours. The temperature was then increased to 55°C at a rate of 10°C / h and kept at a constant temperature for 6 hours. Finally, the temperature was decreased to 20°C at a rate of 8°C / h and demolded to obtain high-performance concrete. Example

[0049] This embodiment provides a method for preparing high-performance concrete material for precast pile processing, including the following steps: Step 1: Preparation of polydopamine-modified fibers Weigh 10.0g of basalt fiber and 60.0mL of Tris-HCl buffer solution (pH=8.5) and add them to the reaction vessel. Stir and add 0.6g of dopamine hydrochloride to the reaction vessel at room temperature. Continue stirring for 3 hours. After the reaction is complete, wait for the temperature of the reaction vessel to drop to room temperature, filter the reaction solution and collect the filter cake. Wash the filter cake with anhydrous ethanol and deionized water until neutral. Transfer the filter cake to a vacuum drying oven at 50℃ and vacuum dry it to constant weight to obtain polydopamine modified fiber.

[0050] Step 2: Preparation of modified mineralized fibers Weigh out 20.0 mL of water glass and 20.0 mL of deionized water and mix them to obtain a water glass dispersion; Weigh 10.0g of polydopamine modified fiber and 60.0mL of saturated calcium hydroxide aqueous solution and add them to the reactor. Stir at room temperature for 2 hours, and then add 40.0mL of water glass dispersion to the reactor at room temperature. After the addition is completed in 30 minutes, stir for 2-3 hours. The modified mineralized fiber is then obtained after post-treatment.

[0051] Step 3: Preparation of high-performance concrete Weigh out 680 parts and 1140 parts of coarse aggregate by weight and add them to the mixing tank. Dry mix for 10 seconds. Then add 380 parts of cement and 60 parts of fly ash and dry mix for 15 seconds. Next, add 105 parts of mixing water and 18 parts of the modified seed crystal microspheres prepared in Example 2 and stir for 90 seconds. Then add 45 parts of mixing water and 6 parts of polycarboxylate superplasticizer and stir for 15 seconds. Then add 8 parts of modified mineralized fiber and stir for 45 seconds. Finally, add 10 parts of the modified microcapsules prepared in Example 5 and stir for 30 seconds. Transfer the material to a mold and let it stand for 3 hours. Then raise the temperature to 60°C at a rate of 15°C / h and keep it at a constant temperature for 8 hours. Then lower the temperature to 30°C at a rate of 10°C / h and demold to obtain high-performance concrete. Example

[0052] This embodiment provides a method for preparing high-performance concrete material for precast pile processing, including the following steps: Step 1: Preparation of polydopamine-modified fibers Weigh 10.0g of basalt fiber and 60.0mL of Tris-HCl buffer solution (pH=8.5) and add them to the reaction vessel. Stir and add 0.6g of dopamine hydrochloride to the reaction vessel at room temperature. Continue stirring for 3 hours. After the reaction is complete, wait for the temperature of the reaction vessel to drop to room temperature, filter the reaction solution and collect the filter cake. Wash the filter cake with anhydrous ethanol and deionized water until neutral. Transfer the filter cake to a vacuum drying oven at 50℃ and vacuum dry it to constant weight to obtain polydopamine modified fiber.

[0053] Step 2: Preparation of modified mineralized fibers Weigh out 20.0 mL of water glass and 20.0 mL of deionized water and mix them to obtain a water glass dispersion; Weigh 10.0g of polydopamine-modified fiber and 60.0mL of saturated calcium hydroxide aqueous solution and add them to the reactor. Stir at room temperature for 2 hours, and then add 40.0mL of water glass dispersion to the reactor at room temperature. After the addition is completed in 24 minutes, stir for 3 hours. The modified mineralized fiber is then obtained after post-treatment.

[0054] Step 3: Preparation of high-performance concrete By weight, 670 parts and 1120 parts of coarse aggregate were weighed and added to the mixing tank and dry-mixed for 9 seconds. Then, 380 parts of cement and 54 parts of fly ash were added and dry-mixed for 12 seconds. Next, 105 parts of mixing water and 17 parts of the modified seed crystal microspheres prepared in Example 3 were added and stirred for 80 seconds. Then, 45 parts of mixing water and 5 parts of polycarboxylate superplasticizer were added and stirred for 12 seconds. Then, 7 parts of modified mineralized fiber were added and stirred for 40 seconds. Finally, 9 parts of the modified microcapsules prepared in Example 6 were added and stirred for 24 seconds. The material was then transferred to a mold and allowed to stand for 3 hours. The temperature was then increased to 60°C at a rate of 12°C / h and kept at a constant temperature for 7 hours. Finally, the temperature was decreased to 24°C at a rate of 9°C / h and demolded to obtain high-performance concrete.

[0055] Comparative Example 1 The difference between this comparative example and Example 9 is that step ③ is omitted in the preparation process of the modified seed crystal microspheres used in step 3.

[0056] Comparative Example 2 The difference between this comparative example and Example 9 is that step II is omitted in the preparation process of the modified microcapsules used in step three.

[0057] Comparative Example 3 The difference between this comparative example and Example 9 is that the modified mineralized fiber was omitted in step three, and basalt fiber was used to replace the modified mineralized fiber in an equal amount.

[0058] Performance testing: The flexural strength, compressive strength, splitting tensile strength, and abrasion resistance of the high-performance concretes prepared in Examples 7-9 and Comparative Examples 1-3 were tested in accordance with the standard GB / T 50081-2019 "Standard for Test Methods of Physical and Mechanical Properties of Concrete". The sulfate resistance of the high-performance concrete prepared in Examples 7-9 and Comparative Examples 1-3 was tested according to the standard GB / T 50082-2024 "Standard for Test Methods of Long-Term Performance and Durability of Concrete". Specific data are shown in Table 1.

[0059] Table 1 - Performance Test Data for Each Sample Flexural strength / MPa 14.81 14.85 14.88 11.61 12.20 9.67 Compressive strength / MPa 67.42 67.84 68.21 55.93 60.02 57.30 Splitting tensile strength / MPa 8.13 8.25 8.38 6.70 7.21 5.70 <![CDATA[Wear amount after 45 cycles / kg·m 2 > 0.96 0.89 0.81 1.30 1.54 1.26 Sulfate resistance grade / level KS150 KS150 KS150 KS90 KS60 KS90 Data Analysis: Comparative analysis of the data in Table 1 reveals that the high-performance concrete prepared by this invention has a flexural strength of 14.88 MPa, a compressive strength of 68.21 MPa, a splitting tensile strength of 8.38 MPa, and an abrasion loss of 0.81 kg·m after 45 cycles. 2 Meanwhile, its sulfate resistance grade is KS150, and all data are superior to the comparative example, indicating that: In Comparative Example 1, the seed crystal microspheres were not subjected to silanization modification, resulting in insufficient dispersibility and poor interfacial compatibility in the slurry system. Due to the lack of active functional groups on the surface, the microspheres could not serve as effective nucleation sites, and the hydration product formation process exhibited uneven characteristics. Pores and microcracks were easily formed in the interfacial transition zone. The accumulation of such defects made the overall structure of the material tend to be loose, and once cracks were formed, they were easy to propagate rapidly, significantly weakening the load-bearing capacity. At the same time, without the protective effect of the functionalized layer, the microspheres were not stable enough in corrosive media and were prone to corrosion and failure, thus significantly reducing the durability. This shows that surface modification of seed crystal microspheres not only helps to improve their dispersibility in the matrix, but also plays a key role in building a dense interface and improving the overall service performance of the material. In Comparative Example 2, the composite microspheres did not form an inorganic shell and consisted only of elastic materials to form repair capsules. Capsules lacking a robust outer shell are prone to breakage during preparation and service, resulting in insufficient morphological stability. At the same time, the release process of the internal active substances lacks control, exhibiting a rapid or disordered release state, failing to achieve the expected sustained release and duration of effect. This change makes the material lack durable repair and protection capabilities when subjected to external abrasion and chemical erosion, and local damage cannot be effectively suppressed, ultimately leading to accelerated overall performance degradation. This indicates that the inorganic shell of the composite microspheres is not only an additional layer in the structure, but also a key factor in ensuring capsule stability, maintaining sustained release function, and improving material durability. In Comparative Example 3, untreated basalt fibers were used directly. Due to the smooth surface of the fibers and the lack of active groups, the interfacial adhesion between the fibers and the matrix was limited, making it difficult to fully exert the anchoring and bridging effects. Cracks could not be effectively blocked by the fibers during propagation and instead tended to extend along the interface, thus significantly weakening the reinforcement effect. At the same time, the lack of dopamine modification and the protection of the mineralization layer resulted in insufficient resistance to erosion, making the fibers prone to deterioration under the influence of external media, and significantly shortening their service life. This demonstrates that untreated basalt fibers not only fail to play a reinforcing and toughening role but may also become a weak link in the structure. This fully illustrates the irreplaceable importance of surface functionalization modification and mineralization treatment in improving interfacial bonding performance and enhancing durability. The final result demonstrates that the components and their treatment methods work synergistically within the system to construct a stable and efficient multi-scale structure. Specifically, seeded microspheres achieve uniform dispersion in the slurry through surface modification and induce the orderly generation of hydration products at the interface, significantly improving the density of the interfacial transition zone. The composite microspheres, protected by an inorganic shell, allow for the slow release of internal active substances, thus continuously exerting repair and protection functions in the local microenvironment. Basalt fibers modified with dopamine and mineralized effectively passivate and block cracks on a macroscopic scale, further enhancing the system's load-bearing capacity and durability. These three components complement each other, strengthening interfacial bonding while also providing self-healing and long-term protection, enabling the material to maintain stable performance under complex service environments, ultimately resulting in a high-performance concrete.

[0060] The preferred embodiments of the present invention disclosed above are merely illustrative of the invention. These preferred embodiments do not exhaustively describe all details, nor do they limit the invention to specific implementations. Clearly, many modifications and variations can be made based on the content of this specification. This specification selects and specifically describes these embodiments to better explain the principles and practical applications of the invention, thereby enabling those skilled in the art to better understand and utilize the invention. The invention is limited only by the claims and their full scope and equivalents.

Claims

1. A high-performance concrete material for precast pile fabrication, characterized in that, The raw materials consist of the following parts by weight: 360-380 parts cement, 50-60 parts fly ash, 660-680 parts fine aggregate, 1100-1140 parts coarse aggregate, 120-150 parts mixing water, 16-18 parts modified seed crystal microspheres, 8-10 parts modified microcapsules, 6-8 parts modified mineralized fiber, and 4-6 parts polycarboxylate superplasticizer. The modified seed crystal microspheres are prepared as follows: anhydrous ethanol, deionized water and seed crystal microspheres are added to a reaction vessel and stirred. After the temperature of the reaction vessel is raised to 40-50℃, acetic acid is used to adjust the pH of the reaction system to 4-5. After stirring for 10-20 min, trimethyl[3-(trimethoxysilyl)propyl]ammonium chloride is added to the reaction vessel and stirred for 2-3 h. After post-treatment, modified seed crystal microspheres are obtained. The ratio of anhydrous ethanol, deionized water, seed crystal microspheres and trimethyl[3-(trimethoxysilyl)propyl]ammonium chloride is 8-10 mL: 2 mL: 1 g: 0.1 g. The method for preparing the seed crystal microspheres includes the following steps: A1. Deionized water, anhydrous ethanol, and tetraethyl orthosilicate were added to a reaction vessel. The pH of the reaction system was adjusted to 2-3 using 1 mol / L hydrochloric acid aqueous solution and stirred at room temperature for 60-80 min. Aluminum nitrate solution was then added dropwise to the reaction vessel over 25-30 min. After the addition was completed, the mixture was stirred at room temperature for 60 min. The pH of the reaction system was then adjusted to 7.5 using 1 mol / L ammonia aqueous solution. The mixture was allowed to stand for 12 h for aging, and then post-processed to obtain microgels. A2. After ball milling and mixing the microgel and lithium carbonate, a mixed powder is obtained. The mixed powder is then calcined to obtain seed crystal microbeads. The method for preparing the modified microcapsules includes the following steps: B1. Acrylamide, sodium acrylate, N,N′-methylenebisacrylamide, L-calcium lactate pentahydrate and Tris buffer were added to a reaction vessel with an ice bath temperature of 10-15℃ and stirred. After adding ammonium persulfate and N,N,N',N'-tetramethylethylenediamine to the reaction vessel, the reaction solution was quickly transferred to a high-speed shear machine and emulsified at 4000 rpm for 5 min. Then, the temperature of the high-speed shear machine was raised to 40-50℃ and kept at that temperature for 2-3 h. The post-processing yielded elastic microspheres. B2. Add the elastic microspheres and saturated calcium hydroxide aqueous solution to the reaction vessel and stir. Then, add tetraethyl orthosilicate dispersion dropwise to the reaction vessel at room temperature. After the dropwise addition is completed within 50-60 minutes, stir for 2-3 hours. The composite microspheres are then obtained through post-treatment. B3. Add composite microspheres, deionized water, ethylene glycol and sodium bicarbonate to the reaction vessel and stir. After purging with nitrogen, reduce the temperature of the reaction vessel to 3-5℃ and add the organic phase dropwise to the reaction vessel. After the addition is completed within 45-60 minutes, keep the temperature and stir for 15-20 minutes. After stirring, let it stand for 10 minutes and then process to obtain modified microcapsules. The preparation method of the modified mineralized fiber includes the following steps: C1. Basalt fiber and Tris-HCl buffer solution at pH=8.5 were added to the reactor and stirred. Dopamine hydrochloride was added to the reactor at room temperature and stirring was continued for 2-3 hours. The post-treatment yielded polydopamine modified fiber. C2. Add polydopamine-modified fibers and saturated calcium hydroxide aqueous solution to a reaction vessel, stir at room temperature for 1-2 hours, and then add water glass dispersion to the reaction vessel at room temperature. After the addition is completed within 20-30 minutes, stir for 2-3 hours. The modified mineralized fibers are then obtained through post-treatment.

2. The high-performance concrete material for precast pile processing according to claim 1, characterized in that, In step A1, the ratio of deionized water, anhydrous ethanol, tetraethyl orthosilicate, and aluminum nitrate solution is 3.0 mL:1.5 mL:1.0-1.2 g:1.0 mL, wherein the aluminum nitrate solution is obtained by mixing aluminum nitrate nonahydrate and deionized water at a ratio of 0.38-0.40 g:1.0 mL; in step A2, the ratio of microgel and lithium carbonate is 1.0 g:1.1-1.2 g.

3. The high-performance concrete material for precast pile processing according to claim 1, characterized in that, In step B1, the ratio of acrylamide, sodium acrylate, N,N′-methylenebisacrylamide, L-calcium lactate pentahydrate, Tris buffer, ammonium persulfate, and N,N,N',N'-tetramethylethylenediamine is 180-200g:400g:2g:80-100g:2800-3000mL:2.5g:2.0mL, wherein the pH of the Tris buffer is 8.5 and the concentration is 0.05mol / L; in step B2, elastic microspheres and saturated calcium hydroxide aqueous solution are used. The ratio of tetraethyl orthosilicate dispersion to total volume is 50g:120-150mL:50mL, wherein the tetraethyl orthosilicate dispersion is obtained by mixing tetraethyl orthosilicate and anhydrous ethanol at a ratio of 6g:25mL; in step B3, the ratio of composite microspheres, deionized water, ethylene glycol, sodium bicarbonate and organic phase is 50g:100-120mL:0.3g:0.1g:60mL, wherein the organic phase is obtained by mixing sebacyl chloride and n-hexane at a ratio of 1g:10mL.

4. The high-performance concrete material for precast pile processing according to claim 1, characterized in that, In step C1, the ratio of basalt fiber, pH 8.5 Tris-HCl buffer solution, and dopamine hydrochloride is 1g:5-6mL:0.05-0.06g; in step C2, the ratio of polydopamine-modified fiber, saturated calcium hydroxide aqueous solution, and water glass dispersion is 1g:5-6mL:4mL, wherein the water glass dispersion is obtained by mixing water glass and deionized water in a ratio of 1mL:1mL.

5. A method for preparing high-performance concrete material for precast pile fabrication as described in any one of claims 1-4, characterized in that, After adding fine and coarse aggregates to the mixing tank and dry mixing for 8-10 seconds, add cement and fly ash and dry mix for 10-15 seconds. Then add 70% mixing water and modified seed crystal microspheres and mix for 60-90 seconds. Next, add 30% mixing water and polycarboxylate superplasticizer and continue mixing for 10-15 seconds. Then add modified mineralized fibers and continue mixing for 30-45 seconds. Finally, add modified microcapsules and continue mixing for 20-30 seconds. After curing, high-performance concrete is obtained.