High-strength environment-friendly concrete and preparation method thereof

Abstract

The invention belongs to the field of building materials, and particularly relates to high-strength environment-friendly concrete and a preparation method thereof.The concrete is mainly prepared from sulphoaluminate cement, silica fume, granulated blast-furnace slag, limestone powder, river sand, gravel, a water reducing agent, basalt fibers, phosphate-grafted chitin nanocrystals and a hyperbranched polyether interface coupling agent. The preparation method comprises the following steps: mixing dry materials except the fibers; preparing the two modified compounds and water into suspension liquid, adding the suspension liquid, and stirring to obtain slurry; and finally, adding fibers, uniformly stirring, forming and curing. Through the synergistic effect of the two compounds, the phosphate grafted chitin nanocrystals can effectively reinforce a matrix and promote hydration, and the hyperbranched polymer can significantly improve interface adhesion and workability, so that the concrete is endowed with high strength, high toughness and excellent durability while the environmental load is reduced.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of building materials, and particularly relates to a high-strength environment-friendly concrete and a preparation method thereof. BACKGROUND

[0002] As the most widely used artificial building material in the world, concrete is an indispensable cornerstone for modern social infrastructure construction. However, the traditional concrete industry's excessive dependence on Portland cement has brought serious challenges of resource consumption and environmental pollution. Cement production is not only a high-energy process, but also an important source of greenhouse gas emissions, which is in sharp contradiction with the current global green and low-carbon development strategy. Therefore, the academic and industrial circles are actively exploring technical paths to replace cement with auxiliary cementitious materials, such as using industrial by-products such as silica fume, granulated blast furnace slag, and limestone powder. These materials can effectively reduce the carbon footprint of concrete and improve its long-term durability, but often come with problems such as slow early strength development and fluctuating mechanical properties, especially when the replacement rate is high, the loosening of the matrix structure due to the "dilution effect" becomes the main bottleneck restricting its application in high-performance fields. In addition, simply relying on physical mixing of mineral admixtures is difficult to achieve active design and precise control of the microstructure of cement-based composite materials.

[0003] In the process of pursuing high performance of concrete, its inherent interface transition zone is always the key factor restricting the breakthrough of mechanical properties and durability. Especially the introduction of various fiber reinforced materials to improve toughness, the interfacial bonding strength between them and the cement matrix directly determines the load transfer efficiency and the final toughening effect. Existing chemical admixtures, such as common water reducing agents, mainly improve the workability of fresh concrete and have limited effect on strengthening the multi-phase interface and optimizing the distribution of hydration products. Although the introduction of nanomaterials (such as nano-silicon dioxide, carbon nanotubes, etc.) has been proven to enhance the matrix at the microscale, these materials often face difficulties in dispersion, high cost, single function, and may bring new environmental and safety risks in the production and use process. Therefore, developing a new multifunctional additive that can simultaneously achieve efficient dispersion, interface coupling, and activation of the cementitious system is an important direction to break through the technical bottlenecks of current environmentally friendly high-performance concrete.

[0004] To address these dual challenges, this invention aims to propose a fundamental solution. Its core idea is not simply to blend existing materials, but rather to create two novel compounds with entirely new structures and specific functions through molecular design and synthesis, and to synergistically apply them to a multi-component composite cementitious system. The first compound focuses on reinforcing and densifying the matrix at the nanoscale. Through chemical modification of natural biomass polymers, it enables them to be stably dispersed in alkaline cement paste and actively participate in the hydration process, becoming preferred nucleation sites for high-strength hydration products. The second compound focuses on constructing strong interfacial bridges at both the micro and macro scales. Its unique molecular structure allows it to simultaneously generate powerful interactions with cement minerals, reinforcing fibers, and the first nano-reinforcing phase, thereby firmly binding material components at different scales into a unified whole. The synergistic effect of these two compounds is expected to significantly reduce cement usage while simultaneously greatly improving the early and later strength, fracture toughness, and resistance to degradation of concrete, ultimately achieving a balance between high strength and high environmental friendliness. Summary of the Invention

[0005] In view of the shortcomings of the existing technology, the purpose of this invention is to provide a high-strength environmentally friendly concrete and its preparation method.

[0006] In a first aspect, the present invention provides a method for preparing high-strength environmentally friendly concrete, comprising the following steps: S1. By weight, add 700-850 parts of sulfoaluminate cement, 30-50 parts of silica fume, 120-180 parts of granulated blast furnace slag, 80-120 parts of limestone powder, 750-950 parts of river sand, and 800-1050 parts of crushed stone to a mixer and dry mix to obtain a dry mixture; premix 5-15 parts of hyperbranched polyether interface coupling agent, 3-10 parts of polycarboxylate-based high-performance water-reducing agent, and 160-210 parts of water and stir to obtain a solution; add 3-10 parts of phosphate ester-grafted chitin nanocrystals to the solution and continue stirring to obtain a composite modifier suspension; S2. Add the composite modifier suspension to the mixer and stir to obtain a slurry. Add 15-30 parts of basalt fiber to the slurry and continue stirring to obtain a concrete mixture. Pour the concrete mixture into a mold, let it stand at room temperature, and then demold to obtain a demolded specimen. Transfer the demolded specimen to a standard curing room for curing.

[0007] In this invention, the reaction mechanism for preparing high-strength environmentally friendly concrete is concentrated in the multi-scale, multi-level synergistic enhancement effect generated between two innovative compounds, a multi-component cementitious system, and reinforcing fibers. Essentially, it achieves fundamental control over macroscopic material properties through active design at the molecular and nanoscale. In the initial stage of concrete mixing, when the composite modifier suspension comes into contact with the dry mix, the hyperbranched polyether interface coupling agent immediately exerts its core regulatory role. Its three-dimensional hyperbranched structure carries a large number of polar functional groups (such as carboxyl groups and ether bonds), which can be rapidly adsorbed onto the surface of cementitious material particles such as sulfoaluminate cement, silica fume, and slag. Through strong steric hindrance and electrostatic repulsion, it effectively breaks the flocculation structure between particles, releasing the trapped free water, thereby achieving an extremely high water reduction rate and endowing the freshly mixed slurry with excellent fluidity and self-compacting properties. Meanwhile, phosphate-grafted chitin nanocrystals are uniformly dispersed in the slurry. The phosphate groups on their surface have a high affinity for calcium ions, allowing them to bind with calcium ions that rapidly dissolve upon contact with water. This not only stabilizes the dispersion of the nanocrystals and prevents their aggregation in alkaline environments, but more importantly, it forms a stable calcium ion-rich layer on the nanocrystal surface. This enriched layer provides a lower-energy nucleation substrate for the deposition of hydrated calcium silicate gel, guiding the hydration products to grow in an orderly and dense manner with the nanocrystals as nuclei. This changes the traditional random stacking pattern of hydration products, constructing a more uniform, dense, and less defective matrix microstructure at the nanoscale. As hydration progresses, the synergistic effect of these two compounds further manifests at the micro and macro interfaces. On one hand, the abundant, dense hydration products with nanocrystals as nuclei intertwine to form a network, significantly enhancing the intrinsic strength and stiffness of the cementitious matrix. On the other hand, the long-chain polyethylene glycol segments and polar groups in the hyperbranched interface coupling agent molecules can be tightly adsorbed onto the surface of basalt fibers, while its hyperbranched core is anchored in the hydration product network through physical interpenetration and chemical bonding, thus constructing a "molecular bridge" interface transition zone between the fiber and the matrix that combines strong adhesion and flexibility. This transition zone can efficiently transfer stress, allowing the reinforcing and toughening effects of the fibers to be fully utilized and inhibiting the initiation and propagation of microcracks. In addition, the secondary pozzolanic reaction of silica fume, slag, etc. in the multi-component cementitious material further consumes the unfavorable calcium hydroxide, generating more gel, which complements the effects of the two compounds, jointly optimizing the pore structure and improving durability. Therefore, the reaction mechanism of the entire system is a complex and orderly process that starts from molecular design, guided by nano-nucleation, supramolecular interface assembly, and multi-component cementitious synergy, ultimately achieving simultaneous leaps in material mechanical properties, durability, and environmental friendliness.

[0008] According to a preferred embodiment of the present invention, in step S1, the dry mixing time is 3-5 minutes.

[0009] According to a preferred embodiment of the present invention, in step S2, the stirring time is 3-5 minutes.

[0010] According to a preferred embodiment of the present invention, the method for preparing the phosphate-grafted chitin nanocrystals includes: A1. Chitosan powder and hydrochloric acid solution were stirred and refluxed at 78-82℃ to obtain a chitosan nanocrystal suspension; the chitosan nanocrystal suspension was cooled to room temperature, centrifuged and washed to obtain a precipitate, the precipitate was redispersed in deionized water and ultrasonically treated to obtain a dispersion. A2. Add an aqueous solution containing 2-hydroxyethyl methacrylate phosphate and potassium persulfate dropwise to the dispersion while stirring. Under nitrogen protection, heat to 68-72℃ to react and obtain a mixture. Dialyze the mixture and freeze-dry it.

[0011] In this invention, the preparation of phosphate-grafted chitin nanocrystals is a precise process involving biomass nanostructuring and surface chemical modification. Its core mechanism lies in obtaining nanocrystal nuclei through controlled acid hydrolysis and introducing highly reactive phosphate functional groups onto their surface using a free radical graft copolymerization reaction. First, using natural chitin as a raw material, selective glycosidic bond cleavage occurs under moderately acidic conditions. Specifically, in a heated reflux hydrochloric acid solution, hydrogen ions preferentially attack and disintegrate the disordered amorphous regions in the chitin fibers, while the more crystalline regions are preserved. Under precise control of temperature, acid concentration, and time, this process can dissociate macroscopic chitin powder into nanoscale crystals with high aspect ratios and large specific surface areas—i.e., chitin nanocrystals. The surface of these nanocrystals is rich in hydroxyl and acetylamino groups, providing abundant reaction sites for subsequent chemical modification. The subsequent surface grafting is a crucial step in endowing them with specific functions. A methacrylate phosphate monomer containing unsaturated double bonds and potassium persulfate, a free radical initiator, were introduced into a nanocrystalline dispersion system. Under an inert atmosphere, heating caused the potassium persulfate to decompose and generate sulfate free radicals. These highly reactive free radicals not only initiated the homopolymerization of the monomers but, more importantly, could abstract hydrogen atoms from the sugar rings on the surface of the chitin nanocrystals, forming large molecular free radical active sites on the nanocrystal surface. These active sites underwent chain growth reactions with the methacrylate phosphate monomers in the surrounding solution, thereby covalently grafting polymer chains onto the nanocrystal surface. The phosphate groups carried at the ends of the grafted polymer side chains possessed extremely strong complexing capabilities. Finally, the target product obtained through dialysis purification was a nano-reinforced phase with a surface coated with a phosphate-functionalized polymer layer. The innovation of this product lies in the fact that it not only retains the inherent high strength, high modulus, and good dispersibility of biomass nanomaterials but also introduces chemical groups through surface modification that can strongly interact with calcium ions in the cement hydration environment, transforming it from an inert filler into an active nanounit that can actively participate in and guide the hydration process.

[0012] According to a preferred embodiment of the present invention, the mass ratio of chitosan powder, 2-hydroxyethyl methacrylate phosphate, and potassium persulfate is 20:(4-6):(0.8-1.2).

[0013] According to a preferred embodiment of the present invention, in step A2, the reaction time is 6-8 hours after heating to 68-72°C.

[0014] According to a preferred embodiment of the present invention, the preparation method of the hyperbranched polyether interfacial coupling agent includes: B1. In a four-necked flask, add pentaerythritol and N-methylpyrrolidone, stir and dissolve under a nitrogen atmosphere, and heat to 98-102℃; add dropwise a mixed solution of adipic acid and p-toluenesulfonic acid dissolved in N-methylpyrrolidone, and after the addition is complete, raise the temperature to 135-145℃ to react and obtain the reaction mixture; cool the reaction mixture to 55-65℃, add monomethoxy polyethylene glycol and dicyclohexylcarbodiimide, and continue the reaction under nitrogen protection to obtain the product; B2. Cool the product and pour it into acetone for precipitation. Filter and collect the precipitate. Wash the precipitate with acetone and dry it in a vacuum drying oven at 38-42℃.

[0015] In this invention, the synthesis of the hyperbranched polyether interfacial coupling agent is a polymerization process based on condensation polymerization and precise molecular structure design. Its mechanism revolves around constructing a multifunctional polymer with a three-dimensional spherical topology, a surface rich in hydrophilic segments, and an interior containing hydrophobic microregions. The synthesis employs a "core-first, then divergent" strategy, using pentaerythritol as the initial core. The pentaerythritol molecule possesses four symmetrically distributed primary hydroxyl groups with equal reactivity, providing a perfect geometric foundation for constructing a highly branched molecular structure. In the first stage, the core molecule undergoes an esterification condensation reaction with adipic acid catalyzed by p-toluenesulfonic acid. The two carboxyl groups of the acid molecule can react with the hydroxyl groups of different core molecules or growing polymer chains. Due to the excess and high reactivity of the reactive functional groups, the polymerization reaction diverges from the core in multiple directions in three-dimensional space, rapidly forming a hyperbranched polyester intermediate with numerous terminal carboxyl groups, low viscosity, and no chain entanglement. The degree of reaction and the acid-base molar ratio in this stage precisely control the branching generation and molecular weight. The second stage is a crucial step in functionalization, end-capping, and structural transformation. After cooling the aforementioned intermediate, the numerous carboxyl groups at its ends, activated by the condensing agent dicyclohexylcarbodiimide, undergo a highly efficient esterification reaction with the terminal hydroxyl groups of monomethoxy polyethylene glycol. The introduction of the long polyethylene glycol chain is like attaching countless flexible hydrophilic "tentacles" to the surface of the hyperbranched molecular sphere. This design brings multiple benefits: on the one hand, the hydrophilic polyethylene glycol segments endow the entire molecule with excellent water solubility and affinity for polar surfaces (such as cement particles and basalt fibers); on the other hand, the structural difference between the hyperbranched core and the polyethylene glycol chain, as well as the conformational freedom of the long chain, allows the molecule to generate a strong steric hindrance effect in solution. The final product, purified by acetone precipitation, is a multifunctional polymer with efficient dispersion, water reduction, toughening, and interfacial bridging functions. Its molecular structure is not a simple linear arrangement, but rather, through precise synthetic control, it forms an intelligent coupling medium capable of simultaneously generating multiple physicochemical interactions with the inorganic mineral phase, organic fiber, and nano-reinforcing phase in concrete.

[0016] According to a preferred embodiment of the present invention, in step B1, the mass ratio of pentaerythritol, adipic acid, p-toluenesulfonic acid, monomethoxy polyethylene glycol and dicyclohexylcarbodiimide is 1:(3.83-5.19):(0.02-0.04):(26.4-32.3):(0.02-0.04).

[0017] According to a preferred embodiment of the present invention, in step B2, the drying time in a vacuum drying oven at 38-42°C is 48-50 hours.

[0018] In a second aspect, the present invention provides a high-strength environmentally friendly concrete prepared according to the method for preparing high-strength environmentally friendly concrete.

[0019] Compared with the prior art, the present invention has the following beneficial effects: (1) In terms of core mechanical properties, the effects of this invention are particularly outstanding. First, the phosphate-grafted chitin nanocrystals, as a nanoscale reinforcing phase, have phosphate groups introduced on their surface that can generate strong chemical complexation with the large amount of calcium ions generated during cement hydration. This not only significantly improves the dispersion stability of nanoparticles in strongly alkaline slurry and avoids agglomeration, but more importantly, it provides a large number of uniformly distributed optimal nucleation sites for hydrated calcium silicate gel, thereby guiding the formation of a denser and more uniform microstructure. This nanoscale regulation of the hydration process greatly accelerates early strength development and lays the foundation for ultra-high strength in the later stages. Second, the synergistic effect of the hyperbranched polyether interface coupling agent and basalt fiber thoroughly improves the toughness and crack resistance of concrete. The unique three-dimensional spherical molecular structure of this coupling agent enables it to tightly bridge the fiber surface and the cement matrix through a dual mechanism of physical adsorption and chemical bonding, firmly combining the brittle cement stone matrix and the fiber into a whole, so that the toughening and crack-resistant capabilities of the fiber can be fully utilized. Ultimately, while maintaining ultra-high compressive strength, the concrete also achieved significant improvements in flexural strength, fracture energy, and flexural toughness, thus overcoming the drawback of high-strength concrete being typically brittle.

[0020] (2) In terms of long-term durability and volume stability, this invention exhibits outstanding advantages. The filling and nucleation effect of phosphate ester-grafted chitin nanocrystals, combined with the pozzolanic reaction and micro-filling effect of the multi-component composite cementitious system (silica fume, slag, limestone powder), produces a multi-scale pore structure refinement effect, which can significantly reduce the proportion of harmful pores and make the concrete structure more compact. This highly compact microstructure constitutes a strong barrier against the intrusion of external corrosive media, so the concrete exhibits an extremely low chloride ion diffusion coefficient and excellent carbonation resistance, ensuring long-term durability. At the same time, the reinforcing effect of the hyperbranched interface coupling agent on the interface reduces the generation of microcracks, while the optimized cementitious system has lower heat of hydration and less autogenous shrinkage, which together promotes the excellent volume stability of the concrete. Its long-term drying shrinkage rate is significantly lower than that of ordinary high-performance concrete, which is of great significance for the preparation of large-volume components or engineering structures requiring high dimensional accuracy.

[0021] (3) This invention achieves a good balance between environmental friendliness and workability. On the one hand, by using a large amount of industrial by-products (silica fume, granulated blast furnace slag) and limestone powder to replace traditional sulfoaluminate cement, the energy consumption and carbon emissions in the production of cementitious materials are significantly reduced from the source, demonstrating significant environmental benefits. On the other hand, the introduction of the two modified compounds does not increase the difficulty of construction, but rather improves the performance of fresh concrete. The hyperbranched polyether interface coupling agent itself has efficient dispersion and plasticizing functions. In synergy with the water-reducing agent, it can still enable the slurry to obtain excellent fluidity and self-compacting properties at extremely low water-cement ratios, ensuring the uniform distribution of basalt fibers in the high-viscosity system. The addition of phosphate ester grafted chitin nanocrystals further stabilizes the slurry state. Therefore, this concrete can achieve vibration-free pouring of complex structures while ensuring a dense and smooth surface after hardening, with comprehensive performance far exceeding that of traditional environmentally friendly concrete. Detailed Implementation

[0022] To facilitate understanding of the present invention, the following embodiments are provided. Those skilled in the art should understand that these embodiments are merely illustrative and should not be construed as limiting the scope of the invention.

[0023] Example 1

[0024] This embodiment provides a method for preparing high-strength, environmentally friendly concrete, the steps of which include: Preparation of phosphate-grafted chitin nanocrystals: A1. Accurately weigh 20.0 g of chitosan powder and place it in a 2000 mL three-necked round-bottom flask. Add 500 mL of 3 mol / L hydrochloric acid solution to the flask. Place the flask on a heated magnetic stirrer with a reflux condenser, turn on the stirrer and heat until the reaction system temperature stabilizes at 80.0 °C. Continue stirring and refluxing at this temperature for 3.0 h. After the reaction is complete, a milky white suspension is obtained, which is the coarse suspension of chitosan nanocrystals. Remove the flask from the heat source and allow it to cool naturally at room temperature (25.0 °C). After the suspension cools to room temperature, aliquot it into centrifuge tubes and centrifuge at 8000 rpm for 10 min using a high-speed refrigerated centrifuge. Carefully discard the supernatant. Add 500 mL of deionized water to the centrifuged precipitate and redisperse it using a vortex mixer. Centrifuge again under the same conditions. Repeat this washing process 5 times until the pH of the supernatant is approximately 7 when measured with pH paper. The resulting white precipitate was transferred to a 1000 mL beaker, and 500 mL of deionized water was added. The mixture was then ultrasonically dispersed using an ultrasonic cell disruptor (probe type, 6 mm diameter). The ultrasonic conditions were set as follows: power 600 W, cycle time 2 seconds of sonication followed by a 1-second interval, for a total ultrasonic treatment time of 60 min. During this time, the beaker was placed in an ice-water bath to prevent overheating. The resulting product was a translucent, homogeneous, and stable dispersion of chitin nanocrystals.

[0025] A2. Surface Grafting Modification. Transfer the above dispersion to a 1000mL three-necked flask and place it on a magnetic stirrer, maintaining a medium stirring speed. Measure 50mL of deionized water into a small beaker, and add 5.0g of 2-hydroxyethyl methacrylate phosphate (HEMAP) monomer and 0.8g of potassium persulfate (KPS) initiator sequentially, stirring until completely dissolved. Using a constant-pressure dropping funnel, slowly and dropwise add the monomer-initiator solution to the continuously stirred chitin nanocrystal dispersion, controlling the dropping time to approximately 30min. After the addition is complete, continuously purge high-purity nitrogen gas (purity ≥99.999%) into the reaction system at a flow rate of 50mL / min for 15min to displace the air in the system. Then switch the nitrogen gas line to the top of the liquid surface for atmosphere protection. Turn on the heater and raise the temperature of the reaction system to 70.0℃ and maintain it constant. At this temperature, continuously stir the reaction for 7.0h to carry out the free radical graft copolymerization reaction. After the reaction was complete, the heating was turned off, and the reaction mixture was allowed to cool to room temperature. The reaction mixture was transferred to a dialysis bag with a molecular weight cutoff of 8000-14000, and dialysis was performed using distilled water as the external dialysis solution under magnetic stirring. The dialysis water was changed every 6 hours for a total of 72 hours to completely remove unreacted HEMAP monomers, homopolymers, and residual salts. Finally, the purified suspension in the dialysis bag was poured into a tray of a freeze dryer for pre-freezing, and then placed in the freeze dryer and freeze-dried at -50°C and 10 Pa for 48 hours to obtain phosphate-grafted chitin nanocrystals. The mass was weighed and recorded, and then sealed and stored in a desiccator for later use.

[0026] Preparation of hyperbranched polyether interfacial coupling agents: B1. Assemble a mechanical stirrer, thermometer, nitrogen inlet tube, and water separator (connected to a reflux condenser) on a dry 500mL four-necked round-bottom flask. Add 6.8g (0.05mol) pentaerythritol and 100mL of N-methylpyrrolidone solvent to the flask. Start stirring and purge with nitrogen at a flow rate of 30mL / min, allowing the solvent to bubble for 5min to remove air. Then, purge nitrogen above the liquid surface to maintain an inert atmosphere. Slowly heat the oil bath to raise the temperature inside the flask to 100°C and stir at this temperature for 15min to ensure complete dissolution of the pentaerythritol. In a 150mL Erlenmeyer flask, weigh 30.6g (0.21mol) adipic acid and 0.3g p-toluenesulfonic acid, add 50mL of N-methylpyrrolidone, gently heat and shake to dissolve completely, preparing a mixed solution. The mixed solution was transferred to a constant-pressure dropping funnel and slowly added dropwise to the flask starting at 100°C under continuous stirring and nitrogen protection, controlling the dropping rate to complete the process within 2.0 h. After the addition was complete, the oil bath temperature was gradually increased, raising the reaction system temperature to 140°C within 30 min. Melt polycondensation was carried out at this temperature, and the water generated in the reaction was collected and removed using a water separator. The reaction continued for 8.0 h, maintaining stable stirring and a nitrogen atmosphere. After the reaction was complete, the oil bath temperature was lowered to 60°C. 196.0 g (approximately 0.196 mol based on a molecular weight of 1000) of monomethoxy polyethylene glycol and 1.2 g of dicyclohexylcarbodiimide were added sequentially to the reaction system. Maintaining the temperature at 60°C and nitrogen protection, the reaction was stirred and continued for 12.0 h to carry out the end-capping grafting reaction. After the reaction was complete, the heating was turned off, and the reaction mixture was allowed to cool naturally to near room temperature (approximately 25°C).

[0027] B2. Under vigorous stirring, slowly pour the viscous reaction product into 1000 mL of anhydrous acetone pre-cooled to 4°C. A pale yellow flocculent precipitate immediately forms. Continue stirring for 10 min to ensure complete precipitation, then filter using a Buchner funnel and collect all the precipitate. Wash the precipitate with 3 × 100 mL of fresh anhydrous acetone on the funnel. Transfer the washed precipitate to a watch glass and place it in a vacuum drying oven at 40°C. Dry continuously at a vacuum of -0.095 MPa for 48 h to completely remove residual solvent and water, yielding a pale yellow to amber viscous resinous solid, which is the finished hyperbranched polyether interfacial coupling agent (HBP-EA). Weigh and seal for storage.

[0028] Preparation of high-strength, environmentally friendly concrete: S1. Dry Material Premixing. Using an electronic balance with an accuracy of 0.1g, weigh the following raw materials in sequence: 700.0g sulfoaluminate cement, 40.0g silica fume, 150.0g granulated blast furnace slag, 100.0g limestone powder, 920.0g river sand, and 880.0g crushed stone. Add all the weighed dry materials to the mixing bowl of a 5L planetary cement mortar mixer. Cover the bowl, start the mixer, and dry mix at low speed (revolution speed 62±5rpm, rotation speed 140±5rpm) for 4.0min to ensure that all powders and aggregates are evenly mixed to obtain a dry mix. Let it stand for later use. Preparation of Composite Modifier Suspension. Take a 500mL plastic beaker and weigh 8.5g of the hyperbranched polyether interface coupling agent (HBP-EA) and 6.0g of polycarboxylate-based high-performance water-reducing agent prepared above using an electronic balance. Measure 180.0g of clean tap water using a graduated cylinder and add it to the same beaker. Using a high-speed shear dispersion emulsifier (rotor diameter 20mm), set the speed to 3000rpm and shear-stir the mixture in the beaker for 5.0min until HBP-EA is completely dissolved, resulting in a clear or slightly turbid viscous solution. Next, accurately weigh 5.5g of the phosphate-grafted chitin nanocrystals (P-ChNC) prepared above using an electronic balance, and slowly sprinkle it into the above solution in small amounts multiple times while the high-speed shear stirring is running continuously. After all the water has been added, continue shearing and stirring at 3000rpm for 10.0min until a uniform composite modifier suspension without obvious particles or agglomerates is obtained.

[0029] S2. Wet Mixing and Fiber Incorporation. Reinstall the mixing bowl onto the planetary mixer. While the mixer is running at low speed, slowly pour all the composite modifier suspension prepared in S1 into the center of the dry mix in the mixing bowl. After all the liquid has been added, immediately switch the mixer to high speed (revolution speed 125±10 rpm, rotation speed 285±10 rpm) and continue mixing for 5.0 min. During this time, occasionally clean the bowl wall with a rubber scraper to ensure complete mixing of the materials, ultimately obtaining a homogeneous slurry with excellent fluidity and gloss. Keeping the mixer running at high speed, slowly and evenly sprinkle 22.5 g (volume admixture approximately 0.75%) of basalt fiber with a length of 12 mm into the slurry in a "snowflake" manner, completing this process within 1.0 min. After all the fibers have been added, continue mixing at high speed for 4.0 min to ensure that all fibers are fully coated and evenly dispersed in the slurry, with no visible fiber clumps, obtaining the final concrete mixture. Step 4: Shaping and Curing. The mixed concrete was poured into a pre-coated 40mm×40mm×160mm triple steel mold in two batches. After each batch, the mold was vibrated 60 times at a frequency of 60 times / min using a cement mortar vibrating table. Excess mortar was then scraped off with a metal scraper, and the surface was smoothed. The molded specimens were immediately covered with plastic film to prevent moisture evaporation and allowed to stand for 24 hours at a temperature of 20.0±1.0℃. After standing, the molds were carefully removed to obtain the demolded concrete specimens. The demolded specimens were immediately placed in a standard curing chamber and cured at a temperature of 20.0±1.0℃ and a relative humidity ≥95% until the specified test age (e.g., 3d, 7d, 28d).

[0030] Example 2

[0031] The difference between this embodiment and Example 1 is that phosphate-grafted chitin nanocrystals are prepared: A1. Accurately weigh 20.0 g of chitosan powder and place it in a 2000 mL three-necked flask. Add 500 mL of 3 mol / L hydrochloric acid solution. Place the flask on a thermostatically heated magnetic stirrer, equip it with a reflux condenser, turn on the stirrer and heat, and stabilize the reaction system temperature at 79.0 °C. Continue stirring and refluxing at this temperature for 3.5 h. After the reaction is complete, a suspension is obtained and allowed to cool naturally to 25.0 °C. Aliquot the suspension and centrifuge at 8000 rpm for 10 min using a high-speed refrigerated centrifuge, discarding the supernatant. Resuspend the precipitate in 500 mL of deionized water and centrifuge again. Repeat this process 5 times until the pH of the supernatant is approximately 7. Add the final precipitate to 500 mL of deionized water and disperse it using an ultrasonic cell disruptor (probe type, 6 mm diameter) at 600 W, with a cycle of 2 s sonication followed by 1 s intermittent sonication, for a total processing time of 90 min. Cool in an ice-water bath throughout the process to obtain a homogeneous dispersion.

[0032] A2. Surface grafting modification. Transfer the dispersion to a 1000 mL three-necked flask and stir. Measure 50 mL of deionized water and dissolve 4.8 g of HEMAP monomer and 1.1 g of KPS initiator. Add this solution dropwise to the dispersion over 30 min using a constant-pressure dropping funnel. After the addition is complete, purge with high-purity nitrogen (50 mL / min) for 15 min, then switch to liquid-top protection. Heat to 71.0 °C and maintain this temperature with stirring for 6.5 h. After the reaction is complete and cooled, transfer the mixture to a dialysis bag with a molecular weight cutoff of 8000-14000 and dialyze with distilled water for 72 h, changing the water every 6 h. Finally, freeze-dry the suspension in the bag (-50 °C, 10 Pa, 48 h) and store in a sealed container.

[0033] Preparation of hyperbranched polyether interfacial coupling agents: B1. Assemble a mechanical stirrer, thermometer, nitrogen inlet tube, and water separator on a dry 500mL four-necked flask. Add 6.8g pentaerythritol and 100mL N-methylpyrrolidone. Stir under nitrogen and heat to 101℃ to dissolve the pentaerythritol. In a 150mL conical flask, dissolve 27.2g adipic acid and 0.2g p-toluenesulfonic acid in 50mL N-methylpyrrolidone. Add this mixture dropwise to the flask over 2.0h using a constant-pressure dropping funnel, maintaining 101℃ and nitrogen protection. After the addition is complete, raise the temperature to 138℃ and carry out a melt polycondensation reaction for 8.5h, removing the generated water using a water separator. After the reaction is complete, cool to 62℃. Add 170.0g monomethoxy polyethylene glycol (Mw=1000) and 1.4g dicyclohexylcarbodiimide, and continue the reaction at 62℃ under nitrogen for 12.0h.

[0034] B2. After the reaction is complete, cool to 25°C; while stirring, pour the product into 1000 mL of anhydrous acetone at 4°C to precipitate, collect the precipitate by filtration, and wash with 3 × 100 mL of fresh acetone. Place the precipitate in a vacuum drying oven at 41°C (-0.095 MPa) and dry for 50 h, then seal and store.

[0035] Preparation of high-strength, environmentally friendly concrete: S1. Dry Material Premixing. Weigh 680.0g of sulfoaluminate cement, 35.0g of silica fume, 130.0g of granulated blast furnace slag, 85.0g of limestone powder, 860.0g of river sand, and 820.0g of crushed stone. Add to a 5L planetary mixer and dry mix at low speed for 3.5min to obtain a dry mix. Second step: Preparation of Composite Modifier Suspension. Weigh 6.5g of HBP-EA and 5.0g of polycarboxylate-based high-performance water-reducing agent into a 500mL beaker and add 160.0g of tap water. Use a high-speed shear dispersion emulsifier to shear and stir at 3000rpm for 5.0min to obtain a solution. Weigh 4.2g of P-ChNC and add it to the solution under continuous shear, continuing to stir at 3000rpm for 10.0min to obtain a uniform suspension.

[0036] S2. Wet Mixing and Fiber Incorporation. While the mixer is running at low speed, pour the suspension into the dry mix. Switch to high speed and mix for 5.0 minutes to obtain a homogeneous slurry. Maintaining high speed, slowly and evenly sprinkle 18.0 g (approximately 0.6% by volume) of 12 mm long basalt fiber into the mixture, and continue high-speed mixing for 3.5 minutes until the fiber is evenly dispersed. Fourth Step, Molding and Curing. Pour the mixture into a 40 mm × 40 mm × 160 mm mold, compact it on a vibrating table, level it, cover it with a film, and let it stand at 20.0 ± 1.0℃ for 24.0 hours before demolding. Transfer the demolded specimens to a standard curing chamber at 20.0 ± 1.0℃ and humidity ≥ 95% for curing until the test age.

[0037] Example 3

[0038] The difference between this embodiment and Example 1 is that phosphate-grafted chitin nanocrystals are prepared: A1. Accurately weigh 20.0 g of chitosan powder and place it in a 2000 mL three-necked flask. Add 500 mL of 3 mol / L hydrochloric acid solution. Place the flask on a thermostatically heated magnetic stirrer, equip it with a reflux condenser, turn on the stirrer and heat, and stabilize the reaction system temperature at 81.0 °C. Continue stirring and refluxing at this temperature for 2.5 h. After the reaction is complete, a suspension is obtained and allowed to cool naturally to 25.0 °C. Aliquot the suspension and centrifuge at 8000 rpm for 10 min using a high-speed refrigerated centrifuge, discarding the supernatant. Resuspend the precipitate in 500 mL of deionized water and centrifuge again. Repeat this process 5 times until the pH of the supernatant is approximately 7. Add the final precipitate to 500 mL of deionized water and disperse it using an ultrasonic cell disruptor (probe type, 6 mm diameter) at 600 W, with a cycle of 2 s sonication followed by 1 s intermittent sonication, for a total processing time of 30 min. Cool in an ice-water bath throughout the process to obtain a homogeneous dispersion.

[0039] A2. Surface grafting modification. Transfer the dispersion to a 1000mL three-necked flask and stir. Measure 50mL of deionized water and dissolve 5.8g of HEMAP monomer and 0.9g of KPS initiator. Add this solution dropwise to the dispersion over 30min using a constant-pressure dropping funnel. After the addition is complete, purge with high-purity nitrogen (50mL / min) for 15min, then switch to liquid-top protection. Heat to 69.0℃ and maintain this temperature with stirring for 7.5h. After the reaction is complete and cooled, transfer the mixture to a dialysis bag with a molecular weight cutoff of 8000-14000 and dialyze with distilled water for 72h, changing the water every 6h. Finally, freeze-dry the suspension in the bag (-50℃, 10Pa, 48h) and store in a sealed container.

[0040] Preparation of hyperbranched polyether interfacial coupling agents: B1. Assemble a mechanical stirrer, thermometer, nitrogen inlet tube, and water separator on a dry 500mL four-necked flask. Add 6.8g pentaerythritol and 100mL N-methylpyrrolidone. Stir under nitrogen and heat to 99℃ to dissolve the pentaerythritol. In a 150mL conical flask, dissolve 33.5g adipic acid and 0.4g p-toluenesulfonic acid in 50mL N-methylpyrrolidone. Add this mixture dropwise to the flask over 2.0h using a constant-pressure dropping funnel, maintaining 99℃ and nitrogen protection. After the addition is complete, raise the temperature to 142℃ and carry out a melt polycondensation reaction for 7.5h, removing the generated water using a water separator. After the reaction is complete, cool to 58℃. Add 210.0g monomethoxy polyethylene glycol (Mw=1000) and 1.0g dicyclohexylcarbodiimide, and continue the reaction at 58℃ under nitrogen for 12.0h.

[0041] B2. After the reaction is complete, cool to 25°C, and while stirring, pour the product into 1000 mL of anhydrous acetone at 4°C to precipitate. Collect the precipitate by filtration and wash with 3 × 100 mL of fresh acetone. Place the precipitate in a vacuum drying oven at 39°C (-0.095 MPa) and dry for 49 h. Store in a sealed container.

[0042] Preparation of high-strength, environmentally friendly concrete: S1. Dry Material Premixing. Weigh 720.0g of sulfoaluminate cement, 45.0g of silica fume, 170.0g of granulated blast furnace slag, 115.0g of limestone powder, 900.0g of river sand, and 950.0g of crushed stone. Add to a 5L planetary mixer and dry mix at low speed for 4.5min to obtain a dry mix. Prepare a composite modifier suspension. Weigh 10.5g of HBP-EA and 8.0g of polycarboxylate-based high-performance water-reducing agent into a 500mL beaker and add 180.0g of tap water. Use a high-speed shear dispersion emulsifier to shear and stir at 3000rpm for 5.0min to obtain a solution. Weigh 7.2g of P-ChNC and add it to the solution under continuous shear, and continue stirring at 3000rpm for 10.0min to obtain a uniform suspension.

[0043] S2. Wet Mixing and Fiber Incorporation. While the mixer is running at low speed, pour the suspension into the dry mix. Switch to high speed and mix for 5.0 minutes to obtain a homogeneous slurry. Maintaining high speed, slowly and evenly sprinkle 27.0 g (approximately 0.9% by volume) of 12 mm long basalt fibers into the mixture, and continue high-speed mixing for 4.5 minutes until the fibers are evenly dispersed. Fourth Step, Molding and Curing. Pour the mixture into a 40 mm × 40 mm × 160 mm mold, compact it on a vibrating table, level it, cover it with a film, and let it stand at 20.0 ± 1.0℃ for 24.0 hours before demolding. Transfer the demolded specimens to a standard curing chamber at 20.0 ± 1.0℃ and humidity ≥ 95% for curing until the test age.

[0044] Comparative Example 1

[0045] The difference between this comparative example and Example 1 is that phosphate-grafted chitin nanocrystals, hyperbranched polyether interface coupling agents, and basalt fibers are not added. 700.0g of sulfoaluminate cement, 40.0g of silica fume, 150.0g of granulated blast furnace slag, 100.0g of limestone powder, 920.0g of river sand, and 880.0g of crushed stone were weighed and added to a 5L planetary mixer. The mixture was dry-mixed at low speed for 4.0min to obtain a dry mix. 180.0g of clean tap water and 6.0g of polycarboxylate-based high-performance water-reducing agent were added directly to the dry mix, and the mixture was then switched to high speed and mixed for 5.0min to obtain ordinary concrete slurry. The slurry was poured into 40mm×40mm×160mm molds, compacted, leveled, covered with a film, and allowed to stand at 20.0±1.0℃ for 24.0h before demolding. Demolded specimens were transferred to a standard curing chamber at 20.0±1.0℃ and humidity ≥95% for curing until the test age.

[0046] Comparative Example 2

[0047] The difference between this comparative example and Example 1 is that only basalt fiber is added, without the addition of phosphate-grafted chitin nanocrystals and hyperbranched polyether interface coupling agent. 700.0g of sulfoaluminate cement, 40.0g of silica fume, 150.0g of granulated blast furnace slag, 100.0g of limestone powder, 920.0g of river sand, and 880.0g of crushed stone were weighed and added to a 5L planetary mixer. The mixture was dry-mixed at low speed for 4.0min to obtain a dry mix. 180.0g of clean tap water and 6.0g of polycarboxylate-based high-performance water-reducing agent were added directly to the dry mix, and the mixture was switched to high speed and stirred for 5.0min to obtain a reference slurry. While maintaining high-speed stirring, 22.5g of basalt fiber with a length of 12mm was slowly and evenly sprinkled into the slurry, and high-speed stirring was continued for another 4.0min. The mixture was placed into a 40mm×40mm×160mm mold, compacted, leveled, and covered with a film. After standing at 20.0±1.0℃ for 24.0h, the molded specimens were demolded. The demolded specimens were then transferred to a standard curing chamber at 20.0±1.0℃ and humidity ≥95% for curing until the test age.

[0048] Comparative Example 3

[0049] The difference between this comparative example and Example 1 is that phosphate-grafted chitin nanocrystals and hyperbranched polyether interfacial coupling agent are added, but basalt fibers are not added. 700.0g of sulfoaluminate cement, 40.0g of silica fume, 150.0g of granulated blast furnace slag, 100.0g of limestone powder, 920.0g of river sand, and 880.0g of crushed stone were weighed and added to a 5L planetary mixer, and dry-mixed at low speed for 4.0min to obtain a dry mix. Separately, 8.5g of the hyperbranched polyether interfacial coupling agent (HBP-EA) and 6.0g of polycarboxylate-based high-performance water-reducing agent were weighed and mixed with 180.0g of tap water in a beaker, and stirred at 3000rpm for 5.0min using a high-speed shear mixer to obtain a solution. Then, 5.5g of phosphate-grafted chitin nanocrystals (P-ChNC) were added, and the mixture was stirred at 3000rpm for 10.0min to obtain a composite modifier suspension. With the mixer running at low speed, pour the suspension into the dry mix. Switch to high speed and mix for 5.0 min to obtain a homogeneous slurry (without adding basalt fiber). Pour the slurry into a 40mm×40mm×160mm mold, vibrate to compact, level, cover with a film, and let stand at 20.0±1.0℃ for 24.0 h before demolding. Transfer the demolded specimens to a standard curing chamber at 20.0±1.0℃ and humidity ≥95% for curing until the test age.

[0050] The performance of the high-strength environmentally friendly concrete obtained in Examples 1-3 and Comparative Examples 1-3 was tested in accordance with national and industry standard testing specifications.

[0051] All concrete specimens were cured in a standard curing room to the specified age and then removed. After standing in a constant temperature and humidity laboratory (temperature 20±2℃, relative humidity 60±5%) for 24 hours, performance tests were conducted.

[0052] Mechanical property testing: The tests were performed using a microcomputer-controlled electro-hydraulic servo universal testing machine. Flexural strength testing was conducted using the three-point bending method, with a specimen clear span of 100 mm and a loading rate controlled at 50 N / s until specimen fracture. The peak load was recorded, and the strength value was calculated. Immediately afterwards, the compressive strength was tested using two half-prism specimens obtained from the flexural test. The specimen was placed at the center of the pressure plate of the compression testing machine, with a loading rate controlled at 2.4 kN / s, continuously and uniformly loaded until specimen failure, and the maximum load was recorded. Six valid specimens were tested for each performance index, and the results were taken as the arithmetic mean.

[0053] Chloride ion permeability test: Durability performance was evaluated using the Rapid Chloride Ion Migration Coefficient (RCM) method. A Φ100mm × 50mm cylindrical specimen, cured for 28 days, was vacuum-saturated with water and then mounted in a test fixture. A 0.3mol / L NaOH solution was injected into the anode tank, and a 10% (w / w) NaCl solution was injected into the cathode tank. A DC power supply was connected, and a constant voltage of 30V was applied. The test duration (typically 6 to 96 hours) was determined based on the initial current. After the test, the specimen was axially split, and a 0.1mol / L AgNO3 solution was sprayed onto the split surface for color development. The depth of the chloride ion penetration front was measured, and the chloride ion unsteady-state migration coefficient was calculated.

[0054] Fracture energy testing: A three-point bending test was conducted on a prism specimen with a pre-cut notch to characterize fracture toughness. The specimen dimensions were 40mm × 40mm × 160mm, with a span of 120mm, and a 10mm deep notch was pre-cut in the middle. On a universal testing machine, a load was applied at a controlled displacement rate of 0.05mm / min, and the load and displacement at the loading point were continuously recorded using sensors until the specimen completely fractured. A complete load-displacement curve was plotted, and the area under the curve (i.e., the energy consumed during fracture) was calculated. Dividing this energy value by the net area of ​​the ligament in the specimen yielded the fracture energy.

[0055] The performance test data above are shown in Table 1.

[0056] Table 1 Performance Test Results

[0057] The test results in Table 1 clearly show that Examples 1-3, through the combined use of phosphate-grafted chitin nanocrystals (P-ChNC), hyperbranched polyether interfacial coupling agent (HBP-EA), and basalt fiber, systematically solved the three core problems commonly found in existing concrete materials represented by the comparative examples: insufficient strength, poor durability (weak impermeability), and high brittleness (low fracture energy). Specifically, compared with Comparative Example 1 (standard ordinary concrete) without any added modifiers, the 28-day compressive strength (92.8-103.6 MPa) and flexural strength (13.9-16.1 MPa) of each example achieved a leap in improvement, with increases of approximately 42-59% and 96-127%, respectively. This is mainly attributed to the nano-filling and reinforcing effect of P-ChNC and the excellent interfacial bonding and bridging effect of HBP-EA, which significantly optimized the microstructure and interfacial transition zone of the cement matrix.

[0058] Regarding durability, the chloride ion migration coefficient of the examples is (0.94-1.28×10⁻⁶). -12 (m² / s) compared to Comparative Example 1 (5.67×10) -12The permeability (m² / s) decreased by approximately 77-83%, indicating a fundamental improvement in its resistance to chloride ion penetration. This is attributed to the refining and densification of the matrix pores by P-ChNC and HBP-EA, effectively blocking the migration pathways of corrosive ions. Compared to Comparative Example 2, which only added basalt fibers, the example also showed significant advantages in strength and impermeability, demonstrating that fiber reinforcement alone cannot achieve matrix densification and interfacial strengthening; the synergistic effect of nanomaterials and polymer modifiers is essential.

[0059] Crucially, the embodiments successfully addressed the material's brittleness by combining the modifier with fibers. The fracture energy of the embodiments (198-285 J / m²) was significantly higher than that of Comparative Example 2 (85 J / m²) containing only fibers and Comparative Example 3 (78 J / m²) containing only modifiers, and even 4.7-6.8 times that of Comparative Example 1 (42 J / m²). This indicates that P-ChNC and HBP-EA not only improved the matrix strength but also greatly enhanced the interfacial bonding between the matrix and basalt fibers, allowing the fibers to fully exert their bridging and toughening effects in preventing microcrack propagation. This achieved a shift from brittle failure to a significant pseudo-plastic failure mode, comprehensively resolving the technical contradiction of simultaneously achieving high strength and high toughness. Therefore, the embodiments of this invention provide a concrete material solution that combines ultra-high mechanical properties, excellent durability, and outstanding toughness.

Claims

1. A method for preparing high-strength environmentally friendly concrete, characterized in that the steps include... include: S1. By weight, add 700-850 parts of sulfoaluminate cement, 30-50 parts of silica fume, 120-180 parts of granulated blast furnace slag, 80-120 parts of limestone powder, 750-950 parts of river sand, and 800-1050 parts of crushed stone to a mixer and dry mix to obtain a dry mixture; premix 5-15 parts of hyperbranched polyether interface coupling agent, 3-10 parts of polycarboxylate-based high-performance water-reducing agent, and 160-210 parts of water and stir to obtain a solution; add 3-10 parts of phosphate ester-grafted chitin nanocrystals to the solution and continue stirring to obtain a composite modifier suspension; S2. Add the composite modifier suspension to the mixer and stir to obtain a slurry. Add 15-30 parts of basalt fiber to the slurry and continue stirring to obtain a concrete mixture. Pour the concrete mixture into a mold, let it stand at room temperature, and then demold to obtain a demolded specimen. Transfer the demolded specimen to a standard curing room for curing.

2. The method for preparing high-strength environmentally friendly concrete according to claim 1, characterized in that, In step S1, the dry mixing time is 3-5 minutes.

3. The method for preparing high-strength environmentally friendly concrete according to claim 1, characterized in that, In step S2, continue stirring for 3-5 minutes.

4. The method for preparing high-strength environmentally friendly concrete according to claim 1, characterized in that, The method for preparing the phosphate-grafted chitin nanocrystals includes: A1. Chitosan powder and hydrochloric acid solution were stirred and refluxed at 78-82℃ to obtain a chitosan nanocrystal suspension; the chitosan nanocrystal suspension was cooled to room temperature, centrifuged and washed to obtain a precipitate, the precipitate was redispersed in deionized water and ultrasonically treated to obtain a dispersion. A2. Add an aqueous solution containing 2-hydroxyethyl methacrylate phosphate and potassium persulfate dropwise to the dispersion while stirring. Under nitrogen protection, heat to 68-72℃ to react and obtain a mixture. Dialyze the mixture and freeze-dry it.

5. The method for preparing high-strength environmentally friendly concrete according to claim 4, characterized in that, The mass ratio of chitosan powder, 2-hydroxyethyl methacrylate phosphate, and potassium persulfate is 20:(4-6):(0.8-1.2).

6. The method for preparing high-strength environmentally friendly concrete according to claim 4, characterized in that, In step A2, the temperature is raised to 68-72℃ and the reaction time is 6-8 hours.

7. The method for preparing high-strength environmentally friendly concrete according to claim 1, characterized in that, The preparation method of the hyperbranched polyether interfacial coupling agent includes: B1. In a four-necked flask, add pentaerythritol and N-methylpyrrolidone, stir and dissolve under a nitrogen atmosphere, and heat to 98-102℃; add dropwise a mixed solution of adipic acid and p-toluenesulfonic acid dissolved in N-methylpyrrolidone, and after the addition is complete, raise the temperature to 135-145℃ to react and obtain the reaction mixture; cool the reaction mixture to 55-65℃, add monomethoxy polyethylene glycol and dicyclohexylcarbodiimide, and continue the reaction under nitrogen protection to obtain the product; B2. Cool the product and pour it into acetone for precipitation. Filter and collect the precipitate. Wash the precipitate with acetone and dry it in a vacuum drying oven at 38-42℃.

8. The method for preparing high-strength environmentally friendly concrete according to claim 7, characterized in that, In step B1, the mass ratio of pentaerythritol, adipic acid, p-toluenesulfonic acid, monomethoxy polyethylene glycol, and dicyclohexylcarbodiimide is 1:(3.83-5.19):(0.02-0.04):(26.4-32.3):(0.02-0.04).

9. The method for preparing high-strength environmentally friendly concrete according to claim 7, characterized in that, In step B2, the drying time in a vacuum drying oven at 38-42℃ is 48-50 hours.

10. A high-strength, environmentally friendly concrete, characterized in that, The high-strength environmentally friendly concrete is prepared by the method of preparing high-strength environmentally friendly concrete according to any one of claims 1-9.

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