Low-carbon high-performance concrete auxiliary cementing material

Abstract

The invention relates to a low-carbon high-performance concrete auxiliary cementing material, and relates to the technical field of building materials, the auxiliary cementing material comprises, by weight, 83.0-94.5 parts of an activated solid waste matrix, 5.0-15.0 parts of a catalysis and functional medium, and 0.5-2.0 parts of a seed crystal inducer. Wherein the activated solid waste matrix is composed of red mud and steel slag, and the catalysis and functional medium is functionalized ionic liquid loaded on the surfaces of matrix particles. The preparation method comprises the following steps: adding the red mud, the steel slag, the seed crystal inducer and the functionalized ionic liquid into closed mechanochemical reaction equipment, and carrying out high-energy grinding reaction in a specific atmosphere at the temperature of 60-80 DEG C after atmosphere replacement. According to the invention, low-energy-consumption and high-efficiency activation of solid waste is realized; through atmosphere control, the final performance of the product can be regulated and controlled. The method is short in technological process and low in energy consumption, and high-value utilization of various industrial solid wastes can be achieved.

Description

Technical Field

[0001] This application relates to the field of building materials technology, and in particular to a low-carbon, high-performance concrete auxiliary cementitious material. Background Technology

[0002] In the concrete industry, partially replacing cement with auxiliary cementitious materials is an important technical approach to reduce carbon emissions and improve concrete performance. Red mud and steel slag, as two industrial solid wastes produced in large quantities, have the potential to be used as auxiliary cementitious materials. However, there are several technical problems in applying these two solid wastes directly or after simple treatment to concrete.

[0003] Existing technologies have limitations in addressing the inherent chemical defects of red mud and steel slag. Red mud, due to the large amount of free alkali remaining from its production process, can lead to excessively high alkalinity in concrete mixes when used directly, posing a potential risk of alkali-aggregate reaction. Steel slag, containing unstable free calcium oxide, undergoes volume expansion during later hydration, causing cracking of the cement stone structure and impairing the long-term durability of concrete. Conventional technical approaches typically employ separate processes to address these two defects, such as acid washing and neutralization of red mud and aging or water quenching of steel slag. These methods are complex, costly, and may introduce new impurity ions, failing to provide a solution for addressing multiple complex defects of solid waste in situ within a single process.

[0004] Furthermore, current technologies largely rely on high-temperature calcination to activate the cementitious activity of inert mineral phases in red mud and steel slag. This method requires heating the material to above 800°C, using thermal energy to drive the decomposition and recombination of the mineral phases. This process not only consumes large amounts of fossil fuels and generates significant carbon emissions, contradicting the low-carbon goals of auxiliary cementitious materials, but the high temperature may also lead to sintering or vitrification of some components, resulting in unstable activation effects. Although mechanical grinding is also used for physical activation, its effect on improving the chemical activity of materials is limited when used alone, making it difficult to prepare high-performance auxiliary cementitious materials. Therefore, developing a low-energy, low-temperature preparation method to achieve efficient activation of solid waste materials is a problem to be solved in this field.

[0005] Meanwhile, the physicochemical properties (such as color) of solid waste-based auxiliary cementitious materials prepared using existing technologies are passively determined by the inherent components of the raw materials. For example, the color of the material mainly depends on the original valence state and content of variable-valence metal elements such as iron, resulting in a single and uncontrollable color. This inherent limitation restricts the application of such materials in fields with specific performance or appearance requirements (such as decorative concrete). Currently, the technical means to actively control the final properties of the product during material preparation are not yet mature, and there is a lack of technical solutions that can customize production according to application needs. Summary of the Invention

[0006] The purpose of this application is to provide a low-carbon, high-performance auxiliary cementitious material for concrete, which solves the problems of unstable raw material supply, large quality fluctuations, high cost, and high energy consumption in existing auxiliary cementitious materials.

[0007] To address the aforementioned technical problems, the first aspect of this application provides a low-carbon, high-performance concrete auxiliary cementitious material, which, by weight, comprises the following components: Activated solid waste matrix: 83–94.5 parts; Catalytic and functional media: 5–15 parts; Seed inducer: 0.5-2.0 parts.

[0008] The activated solid waste matrix is ​​composed of red mud and steel slag. The catalytic and functional medium is a functionalized ionic liquid, which exists in a loaded form on the particle surface of the activated solid waste matrix.

[0009] In a preferred embodiment, the activated solid waste matrix contains 40.0% to 60.0% red mud and 40.0% to 60.0% steel slag by weight.

[0010] In a preferred embodiment, the functionalized ionic liquid is a carboxylic acid-functionalized choline ionic liquid.

[0011] Furthermore, in a more preferred embodiment, the carboxylic acid-functionalized choline ionic liquid is acetylcholine.

[0012] A second aspect of the present invention provides a method for preparing the aforementioned low-carbon high-performance concrete auxiliary cementitious material, comprising the following steps: (a) Raw material mixing and atmosphere replacement: Red mud, steel slag, seed crystal inducer and the functionalized ionic liquid are added to a closed mechanochemical reaction device. After the air inside the device is removed, a specific atmosphere gas is introduced for replacement. (b) Mechanochemical reaction: Mechanochemical reaction is carried out by high-energy grinding under the specific atmosphere; (c) Cooling and discharge: After the reaction is completed, the product is cooled and taken out to obtain the auxiliary cementitious material.

[0013] In a preferred embodiment, the reaction temperature of the mechanochemical reaction in step (b) is 60°C to 80°C.

[0014] In a preferred embodiment, the duration of the mechanochemical reaction in step (b) is 60 to 120 minutes.

[0015] In a preferred embodiment, the specific atmosphere gas in step (a) is an inert atmosphere or a slightly reducing atmosphere.

[0016] Furthermore, in a more preferred embodiment, the inert atmosphere is nitrogen; the micro-reducing atmosphere is a mixture of nitrogen and hydrogen, wherein the volume percentage of hydrogen is 1.0%-5.0%.

[0017] In a preferred embodiment, the high-energy grinding speed in step (b) is 400 rpm to 600 rpm.

[0018] In summary, this application includes at least one of the following beneficial technical effects: 1. This application utilizes a specific functionalized ionic liquid as both a catalyst and a functional medium, simultaneously addressing two major application bottlenecks in a single preparation process: the strong alkalinity of red mud and the stability of free calcium oxide in steel slag. This functionalized ionic liquid can convert harmful components in solid waste into chemically stable salts in situ, fundamentally improving the chemical stability and environmental compatibility of the final product, and avoiding the problems of secondary pollution or the inability to eradicate inherent defects introduced by traditional methods. 2. The low-temperature mechanochemical preparation method employed in this application efficiently couples the chemical reaction with the mechanical activation process. Compared with traditional high-temperature calcination activation technology, this method operates within a significantly lower temperature range, drastically reducing energy consumption and carbon emissions during the production process. Simultaneously, the synergistic effect of mechanical force and the chemical action of ionic liquids efficiently disrupts the inert crystal structure of solid waste and promotes mineral phase reconstruction, achieving high-efficiency activation with low energy consumption. 3. This application introduces specific atmosphere control during the preparation process, thereby endowing the final product with controllable performance. By selecting an inert atmosphere or a micro-reducing atmosphere, the final valence state of variable-valence metal elements present in solid waste raw materials can be actively controlled, thus obtaining auxiliary cementitious materials with specific physical (e.g., color) or chemical (e.g., redox potential) properties. This allows the product to meet the customized needs of different application scenarios (e.g., decorative concrete or corrosion-resistant environments), expanding the breadth of high-value utilization of solid waste. Detailed Implementation

[0019] This application will be further described in detail below.

[0020] Example 1: This embodiment provides a low-carbon, high-performance concrete auxiliary cementitious material, comprising: Raw material preparation: Red mud: Bayer process red mud, dried in an oven at 105°C for 12 hours and passed through a 200-mesh sieve.

[0021] Steel slag: Converter steel slag, after being crushed and magnetically separated, is ground to an average particle size (D50) of 15μm.

[0022] Seed inducing agent: Commercially available nano-hydrated calcium silicate powder.

[0023] Functionalized ionic liquid: commercially available acetylcholine, 98% purity.

[0024] Component composition: Weigh the following components by weight: Red mud: 44.25 parts Steel slag: 44.25 parts Acetylcholine: 10.0 parts Nano-hydrated calcium silicate powder: 1.5 parts Preparation steps: (1) The weighed red mud, steel slag and nano-hydrated calcium silicate powder are loaded into a planetary high-energy ball mill with a temperature control jacket and gas pipeline. The ball-to-material mass ratio is 10:1.

[0025] (2) Seal the ball mill jar and evacuate it until the absolute pressure inside the jar is below 10 kPa. Then, introduce a mixture of nitrogen and hydrogen (with hydrogen accounting for 3.0% of the volume) to atmospheric pressure and repeat this atmosphere replacement operation twice.

[0026] (3) Inject 10.0 parts of acetylcholine through the injection valve and run at 100 rpm for 15 minutes to mix the components evenly.

[0027] (4) Start the temperature control jacket to raise the material temperature to and maintain it at 70°C. Then, increase the ball mill speed to 500 rpm to carry out the mechanochemical reaction for 90 minutes.

[0028] (5) After the reaction is complete, stop heating and grinding, and cool the material to below 40°C by passing cooling water through the jacket. Open the ball mill jar, take out the product, and you will get the auxiliary cementitious material.

[0029] Example 2: This embodiment provides a low-carbon, high-performance concrete auxiliary cementitious material, comprising: Raw material preparation: Same as Example 1.

[0030] Component composition: Weigh the following components by weight: Red mud: 37.4 parts Steel slag: 56.1 parts Acetylcholine: 6.0 parts Nano-hydrated calcium silicate powder: 0.5 parts Preparation steps: (1) The weighed red mud, steel slag and nano-hydrated calcium silicate powder are loaded into a planetary high-energy ball mill with a temperature control jacket and gas pipeline. The ball-to-material mass ratio is 8:1.

[0031] (2) Seal the ball mill jar, evacuate it until the absolute pressure inside the jar is below 10 kPa, then introduce high-purity nitrogen to atmospheric pressure, and repeat this atmosphere replacement operation 3 times.

[0032] (3) Inject 6.0 parts of acetic choline through the injection valve and run at 80 rpm for 20 minutes to mix the components evenly.

[0033] (4) Start the temperature control jacket to raise the material temperature to and maintain it at 60°C. Then, increase the ball mill speed to 400 rpm to carry out the mechanochemical reaction for 60 minutes.

[0034] (5) After the reaction is complete, stop heating and grinding, and cool the material to below 40°C by passing cooling water through the jacket. Open the ball mill jar, take out the product, and you will get the auxiliary cementitious material.

[0035] Example 3: This embodiment provides a low-carbon, high-performance concrete auxiliary cementitious material, comprising: Raw material preparation: Same as Example 1.

[0036] Component composition: Weigh the following components by weight: Red mud: 49.8 parts Steel slag: 33.2 parts Acetylcholine: 15.0 parts Nano-hydrated calcium silicate powder: 2.0 parts Preparation steps: (1) The weighed red mud, steel slag and nano-hydrated calcium silicate powder are loaded into a planetary high-energy ball mill with a temperature control jacket and gas pipeline. The ball-to-material mass ratio is 12:1.

[0037] (2) Seal the ball mill jar and evacuate it until the absolute pressure inside the jar is below 10 kPa. Then, introduce a mixture of nitrogen and hydrogen (of which the volume percentage of hydrogen is 5.0%) to atmospheric pressure. Repeat this atmosphere replacement operation twice.

[0038] (3) Inject 15.0 parts of acetic choline through the injection valve and run at 120 rpm for 10 minutes to mix the components evenly.

[0039] (4) Start the temperature control jacket to raise the material temperature to and maintain it at 80°C. Then, increase the ball mill speed to 600 rpm to carry out the mechanochemical reaction for 120 minutes.

[0040] (5) After the reaction is complete, stop heating and grinding, and cool the material to below 40°C by passing cooling water through the jacket. Open the ball mill jar, take out the product, and you will get the auxiliary cementitious material.

[0041] Comparative Example 1 The difference from Example 1 is that 10.0 parts of acetylcholine were replaced with 10.0 parts of deionized water, while the rest were the same.

[0042] Comparative Example 2 The difference from Example 1 is that acetylcholine is not added and a dry mechanochemical reaction is carried out; otherwise, they are the same.

[0043] Comparative Example 3 The difference from Example 1 is that no seed inducer (nano-hydrated calcium silicate powder) is added; all other aspects are the same.

[0044] Comparative Example 4 Compared with Example 1, the difference is that in step (4), instead of high-energy grinding at 500 rpm, low-speed stirring is performed at 100 rpm, while the rest are the same.

[0045] Comparative Example 5 Compared with Example 1, the difference is that in step (4), no heating operation is performed, and the entire mechanochemical reaction process is carried out at room temperature (25°C), while the rest are the same.

[0046] Comparative Example 6 Compared with Example 1, the difference is that in step (2), no vacuuming and atmosphere replacement operations are performed, and the entire preparation process is carried out in an air atmosphere, while the rest are the same.

[0047] Test Example 1: Chemical Stability and Leaching Characteristics Test of Auxiliary Cementitious Materials 1. pH test of leachate This test is used to evaluate the alkali release capacity of different sample powders in an aqueous environment.

[0048] Experimental steps: (1) Use an electronic balance (accuracy 0.01g) to accurately weigh 10.00g of each of the dry powder samples prepared in Examples 1-3 and Comparative Examples 1-2, and place them in 250mL beakers respectively.

[0049] (2) The sample was added to a beaker containing 100.0 mL of deionized water to form a suspension with a solid-liquid mass ratio of 1:10.

[0050] (3) Place the beaker on a magnetic stirrer and stir continuously at 300 rpm for 30 minutes to ensure that the powder is fully dispersed.

[0051] (4) Stop stirring and let the suspension stand for 10 minutes. After most of the solid particles have settled, use a calibrated pH meter (accuracy 0.01) to measure the pH value of the supernatant.

[0052] (5) Each sample was tested three times, all data were recorded and their arithmetic mean was calculated.

[0053] 2. Stability Testing This test is used to evaluate the impact of using different samples as auxiliary cementitious materials on the volume stability of the cement matrix.

[0054] Experimental steps: (1) Preparation of cement paste: The samples prepared by Examples 1-3 and Comparative Examples 1-2 were mixed with PO 42.5 cement at a mass substitution rate of 30% to prepare the test group cement paste. The water-cement ratio was fixed at 0.35.

[0055] (2) Molding and curing: The prepared paste is poured into a 25mm×25mm×285mm mold and compacted by vibration. The mold is placed in a standard curing room (temperature 20±1℃, relative humidity ≥90%) for 24 hours and then demolded.

[0056] (3) Initial length measurement: The initial length L0 of each specimen after demolding was measured using a length comparator, accurate to 0.01 mm.

[0057] (4) High-pressure autoclave cooking: After measuring the initial length, place the specimen horizontally on the specimen rack inside the autoclave. Close the autoclave lid and uniformly raise the saturated steam pressure inside the autoclave to 2.0 MPa within 3 hours, and maintain this pressure for 3 hours.

[0058] (5) Cooling and final length measurement: Stop heating and allow the autoclave to cool naturally to room temperature within 1.5 hours. Open the lid and take out the specimen. After it cools to 20±1℃, use the length comparator to measure its final length L1 again.

[0059] (6) Calculate the expansion rate: Calculate the length change rate of each specimen according to the formula expansion rate (%) = [(L1-L0) / (285-25)] × 100%. Prepare three specimens for each sample and take the average value as the final result.

[0060] The experimental data are shown in Table 1: Table 1. Test results of chemical stability and leaching characteristics of auxiliary cementitious materials

[0061] The data in Table 1 show that the pH value of the leachate prepared by Examples 1-3 was all below 10.0, and the expansion rate after autoclaving was all below 0.05%. In contrast, the pH value of the leachate prepared by Comparative Examples 1 and 2 was all above 12.0, and the expansion rate after autoclaving was all above 1.0%.

[0062] In this technical solution, a functionalized ionic liquid is used as a non-aqueous reaction medium. Its anions (such as the acetate ion in acetylcholine) undergo an acid-base neutralization reaction with the free alkaline components present in the red mud. This reaction converts the highly soluble strong base into a salt with lower solubility and stable chemical properties, which is then fixed on the surface of the product particles. As a result, when the final product comes into contact with water, the number of alkaline ions released into the water is reduced, which manifests as a decrease in the pH value of the leachate.

[0063] Simultaneously, the anions of the functionalized ionic liquid chemically react with the free calcium oxide present in the steel slag, converting it into soluble or complexed calcium salts. This conversion process consumes f-CaO during the material preparation stage, preventing the formation of Ca(OH)2 due to volume expansion during later hydration, thereby suppressing the macroscopic volume expansion caused by f-CaO. Therefore, the sample prepared using this technical solution showed an expansion rate of less than 0.05% in the stability test, while the comparative sample without this medium showed an expansion rate of more than 1.0% due to the later hydration of f-CaO.

[0064] Test Example 2: Gelation Activity Test of Auxiliary Cementitious Materials Gelation activity index test This test is used to evaluate the contribution of different samples as auxiliary cementitious materials to the mechanical properties of the cement matrix. The core indicator is the 28-day strength activity index (SAI). Experimental procedures: (1) Ingredients: Reference group: Weigh 450g PO 42.5 cement, 1350g standard sand and 225g water.

[0065] Experimental group: Weigh 315g of PO 42.5 cement, 135g of sample powder prepared by Examples 1-3 and Comparative Examples 1-5 (i.e., replacing cement by 30% by mass), 1350g of standard sand and 225g of water.

[0066] (2) Mixing and molding: Pour the cementitious material (cement or a mixture of cement and the sample) and standard sand into a mixing bowl and stir at low speed for 30 seconds.

[0067] Slowly add all the water and continue stirring at low speed for 30 seconds.

[0068] Switch to high speed and stir for 60 seconds.

[0069] Stop the machine for 15 seconds, then stir at high speed again for 60 seconds.

[0070] The prepared cement mortar was poured into a 40mm×40mm×160mm mold and compacted on a vibrating table.

[0071] (3) Maintenance and testing: After molding, the specimens were placed in a standard curing room (temperature 20±1℃, relative humidity ≥90%) for 24 hours and then demolded.

[0072] Immediately after demolding, the specimens were placed in water at (20±1℃) and continued to be cured for 28 days.

[0073] Remove the specimen from the water, wipe off the surface moisture, and test the compressive strength using a compressive strength testing machine at a loading rate of 2.4 kN / s. Test 6 compressive strength values ​​for each group of samples and take their arithmetic mean. (4) Calculation: Strength activity index (%) = (28-day compressive strength of test group mortar / 28-day compressive strength of reference group mortar) × 100%.

[0074] The experimental data are shown in Table 2: Table 2. Test results of the gelling activity of auxiliary cementing materials

[0075] Test Result Analysis The data in Table 2 show that the cement mortars corresponding to the samples prepared in Examples 1-3 all have a 28-day strength activity index of over 80%. In contrast, the samples prepared in Comparative Examples 1-5 have significantly lower strength activity indices than the sample samples in the examples, with Comparative Example 2 (dry grinding) and Comparative Example 4 (low-speed stirring) having activity indices below 55%.

[0076] The low-temperature mechanochemical method employed in this technical solution uses high-energy grinding to input mechanical energy, thereby disrupting the original stable lattice structure of red mud and steel slag, increasing the specific surface area, and exposing chemically reactive sites. This is the basis for the material to acquire gelling activity. In contrast, Comparative Example 4, due to the lack of high-energy grinding mechanical force input, has a low degree of physical activation, and therefore its strength activity index is only 51%.

[0077] Simultaneously with the application of mechanical force, the functionalized ionic liquid, acting as the reaction medium, promotes element migration and recombination between solid waste particles in its ionic environment, resulting in the in-situ formation of a calcium aluminosilicate precursor layer with potential cementing activity. This process pre-activates the chemical activity of the solid waste. Comparative Example 1 (water substitution) and Comparative Example 2 (no medium), lacking this specific chemical reaction environment, failed to effectively form this precursor layer, resulting in activity indices of only 55% and 48%, respectively. Furthermore, increasing the reaction temperature (comparative Example 1 and Comparative Example 5) can improve the ion migration rate and reaction efficiency, thereby obtaining products with higher activity indices. Finally, the introduction of a seed inducer (comparative Example 1 and Comparative Example 3) provides additional nucleation sites for the subsequent cement hydration process, lowers the energy barrier for the formation of hydration products, and further enhances the strength performance of the material in the cement system.

[0078] Test Example 3: Atmosphere Control Effect Test Powder color test This test is used to evaluate the color difference of the final product powder under different preparation atmospheres.

[0079] Experimental steps: (1) Sample preparation: Take about 5g of each of the dry powder samples prepared in Example 1 and Comparative Example 6. Put the powder into a special powder sample dish and gently press it with a flat glass plate to form a flat and dense test surface.

[0080] (2) Instrument calibration: Using a portable colorimeter, calibrate the instrument in sequence using a standard white plate and a standard black tube, according to the instrument operating procedure.

[0081] (3) Data Acquisition: Place the calibrated colorimeter measuring port vertically against the surface of the sample dish to be tested, ensuring no light leakage. Trigger the measurement and record the CIELAB color space parameters displayed by the instrument, including the luminance value L. * Red / green value a and yellow / blue value b.

[0082] (4) Repeated measurements: Three different locations were selected on the surface of each sample for measurement, and the L value was recorded each time. * a * b * The values ​​are calculated, and their arithmetic mean is taken as the final test result for the sample.

[0083] The experimental data are shown in Table 3: Table 3. Color Test Results of Auxiliary Cementitious Material Powder

[0084] Test Result Analysis Table 3 shows that the sample prepared in Example 1 has a brightness value L of 38.4. The sample prepared in Comparative Example 6 has a brightness value L of 55.7. A lower L value indicates a darker material color. The values ​​of a and b for the sample in Example 1 are also shown. * The values ​​were also lower than those of the sample in Comparative Example 6, indicating that its redness and yellowness were lower.

[0085] This technical solution introduces a specific reaction atmosphere during the preparation process. Red mud and steel slag contain variable-valence metal elements, mainly iron. Under the air atmosphere of Comparative Example 6, the localized high temperature during the mechanochemical reaction promotes the oxidation of iron to a higher valence state (ferric oxide). Ferric oxide exhibits a reddish-brown color, corresponding to a higher brightness value L and higher a and b values. * value.

[0086] In the micro-reducing atmosphere of Example 1, the reducing component (hydrogen) in the atmosphere inhibited the oxidation of iron and promoted its partial conversion to lower valence states (ferrous iron or metallic iron). These lower valence iron compounds are darker in color, typically grayish-black or black, thus significantly reducing the brightness value L* of the final product and shifting its color towards dark gray. Therefore, by controlling the atmosphere within the reaction equipment during the mechanochemical reaction stage, the final valence state of the variable-valence metal elements in the product can be actively controlled, thereby achieving control over the color of the final product.

[0087] The embodiments described herein are preferred embodiments of this application and are not intended to limit the scope of protection of this application. Identical components are indicated by the same reference numerals. Therefore, all equivalent changes made to the structure, shape, and principle of this application should be included within the scope of protection of this application.

Claims

1. A low-carbon, high-performance concrete auxiliary cementitious material, characterized in that, By weight, it includes the following components: Activated solid waste matrix: 83–94.5 parts; Catalytic and functional media: 5–15 parts; Seed inducer: 0.5–2 parts; The activated solid waste matrix is ​​composed of red mud and steel slag; The catalytic and functional medium is a functionalized ionic liquid, which is loaded onto the particle surface of the activated solid waste matrix.

2. The low-carbon high-performance concrete auxiliary cementitious material according to claim 1, characterized in that, In the activated solid waste matrix, the weight percentage of red mud is 40.0% to 60.0%, and the weight percentage of steel slag is 40.0% to 60.0%.

3. The low-carbon high-performance concrete auxiliary cementitious material according to claim 1, characterized in that, The functionalized ionic liquid is a carboxylic acid-functionalized choline ionic liquid.

4. The low-carbon high-performance concrete auxiliary cementitious material according to claim 3, characterized in that, The carboxylic acid-functionalized choline ionic liquid is acetic acid choline.

5. A method for preparing a low-carbon, high-performance concrete auxiliary cementitious material, as described in any one of claims 1-4, characterized in that, Includes the following steps: S1. Raw material mixing and atmosphere replacement: Red mud, steel slag, seed crystal inducer and the functionalized ionic liquid are added to a closed mechanochemical reaction device. After the air inside the device is removed, a specific atmosphere gas is introduced for replacement. S2, Mechanochemical reaction: Mechanochemical reaction is carried out by high-energy grinding under the specified atmosphere; S3. Cooling and Discharging: After the reaction is complete, the product is cooled and removed to obtain the auxiliary cementitious material.

6. The method for preparing a low-carbon, high-performance concrete auxiliary cementitious material according to claim 5, characterized in that, The reaction temperature of the mechanochemical reaction in step S2 is 60℃~80℃.

7. The method for preparing a low-carbon, high-performance concrete auxiliary cementitious material according to claim 5, characterized in that, The duration of the mechanochemical reaction described in step S2 is 60 to 120 minutes.

8. The method for preparing a low-carbon, high-performance concrete auxiliary cementitious material according to claim 5, characterized in that, The specific atmosphere gas mentioned in step S1 is an inert atmosphere or a slightly reducing atmosphere.

9. The method for preparing a low-carbon, high-performance concrete auxiliary cementitious material according to claim 5, characterized in that, The inert atmosphere is nitrogen; The micro-reducing atmosphere is a mixture of nitrogen and hydrogen, wherein the volume percentage of hydrogen is 1.0% to 5.0%.

10. The method for preparing a low-carbon, high-performance concrete auxiliary cementitious material according to claim 5, characterized in that, The high-energy grinding speed in step S2 is 400 rpm to 600 rpm.

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