High-performance concrete and preparation method thereof

Abstract

The invention discloses high-performance concrete and a preparation method thereof, and relates to the technical field of concrete, the high-performance concrete comprises the following components: a gel material, a CO2 load, a fine aggregate, a coarse aggregate, an additive and water; in the preparation process of the CO2 load, firstly, gradient pickling is conducted through an oxalic acid solution, micropores and mesopores with different sizes are formed, the mesopores reserve aluminum oxalate chelate as CO2 adsorption points and Fe < 2 + > binding sites, Fe < 2 + > and the aluminum oxalate chelate are combined to form a Fe-OOC-Al structure, and the adsorption capacity of the Fe < 2 + > and the aluminum oxalate chelate is higher; then, carbon quantum dot layers are plated in the mesopores, the carbon quantum dot layers can generate local high temperature when generating friction heat in the stirring process of concrete preparation, Fe-CO2 coordination bond breakage is promoted, CO2 release is facilitated, released CO2 reacts with a cementing material to form carbonized products calcium carbonate and silica gel, mineralization maintenance in the concrete preparation process is facilitated, and the service life of the concrete is prolonged. Further, the mechanical property of the concrete can be improved, and the porosity is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of concrete, and particularly relates to a high-performance concrete and a preparation method thereof. Background Art

[0002] As an environmentally friendly and integrated technology, carbonation curing achieves the dual goals of greenhouse gas sequestration and optimization of the performance of building materials. This technology converts carbon dioxide into a stable carbonate form at the initial stage of the hydration reaction, not only achieving the goal of carbon sequestration, but also significantly improving the initial mechanical properties and structural compactness of the cement-based material, thereby enhancing its durability in harsh service environments. Compared with traditional steam curing or high-temperature water curing processes, this technology exhibits significant energy-saving advantages, and thus has attracted much attention from the academic and engineering circles under the background of the global low-carbon transformation.

[0003] The core of carbonation curing is to utilize the chemical reaction between CO2 and alkaline substances such as calcium hydroxide (Ca(OH)2) and calcium silicate in the cement-based material to generate calcium carbonate (CaCO3) and water. This process not only fixes CO2 in the material in a stable form, but also fills the pores inside the material through the formation of calcium carbonate, improving the density and strength of the material. Specifically, carbonation curing can accelerate the hydration reaction of cement and significantly improve the early strength. For example, at the age of 3 days, carbonation curing can increase the concrete strength by more than 20%. The formation of calcium carbonate fills the pores inside the material, reduces the porosity, and improves the impermeability and durability. Carbonation curing converts the easily soluble calcium hydroxide into stable calcium carbonate, reducing the mass loss and strength loss of the material in a corrosive environment. Therefore, carbonation curing can be used as an alternative to traditional accelerated curing technologies such as steam curing and high-temperature water curing, significantly reducing energy consumption. For example, carbonation curing can be carried out at normal temperature and pressure without high-temperature and high-pressure equipment. In the field of construction engineering technology, carbonation curing can improve the mechanical properties and durability of recycled aggregate concrete to reach the level of original aggregate concrete; carbonation curing is also applicable to large-volume projects (such as dams and foundations), improving the early strength through carbonation curing and reducing the risk of cracks.

[0004] However, it should be noted that there are still several key bottlenecks in the current carbonation curing technology: firstly, the depth of carbon dioxide reaction is limited to the surface area of the material, resulting in limited carbon sequestration efficiency and affecting the effect of mineralization curing in the concrete preparation process; secondly, the dependence of the existing process on high-pressure reaction conditions limits its direct application at the engineering site. Summary of the Invention

[0005] The purpose of the present invention is to provide a high-performance concrete and a preparation method thereof, and solve the following technical problems: How to improve the effect of carbon dioxide mineralization curing in the concrete preparation process.

[0006] The object of the present invention can be achieved by the following technical solutions: In a first aspect, the present invention discloses a high-performance concrete, which comprises the following components in parts by weight: 35-50 parts of gel material, 2-10 parts of CO2 load, 60-80 parts of fine aggregate, 70-120 parts of coarse aggregate, 0.5-2 parts of admixture, and 13-17 parts of water; Preferably, it comprises the following components in parts by weight: 42 parts of gel material, 6 parts of CO2 load, 70 parts of fine aggregate, 95 parts of coarse aggregate, 1 part of admixture, and 15 parts of water.

[0007] Among them, the CO2 load is modified zeolite loaded with CO2 gas;

[0008] The preparation method of the CO2 load comprises the following steps: Step A1: Gradient acidification treatment of natural zeolite in oxalic acid solution to obtain acidified zeolite; Step A2: Immerse the acidified zeolite in an ethanol solution of FeCl2·4H2O with a concentration of 0.5 mol / L, evacuate to -0.08 MPa, oscillate for 30 min, filter and take out, dry, and calcine in a nitrogen atmosphere at 350 °C for 1 h to obtain a modified zeolite precursor; Step A3: Ultrasonically treat the modified zeolite precursor in an ethanol solution of carbon quantum dots with a concentration of 2 mg / mL for 20-30 min, take it out after completion and cure at 120 °C for 10 min to form a carbon quantum dot layer, then ultrasonically treat it in an ethanol solution of tetraethyl orthosilicate with a concentration of 10 wt% for 10-20 min, take it out after completion and cure at 120 °C for 10 min to form a SiO2 nanoporous layer to obtain modified zeolite; Step A4: Place the modified zeolite in a CO2 atmosphere with a concentration of 70%-80%, first adsorb at 0.8 MPa for 30 min, then reduce the pressure to 0.1 MPa and adsorb for 1 h to obtain the CO2 load.

[0009] Furthermore, the gradient acidification treatment includes three steps, namely: The first step: Treat natural zeolite in an oxalic acid solution with a temperature of 60 °C and a concentration of 2 wt% for 1 h to remove impurities such as Mg and Ca; The second step: After filtration, transfer it to an oxalic acid solution with a temperature of 80 °C and a concentration of 5 wt% for 2 h to form micropores with a pore size of 0.5-1 nm and retain the molecular sieve characteristics of zeolite; The third step: After filtration, transfer it to an oxalic acid solution with a temperature of 25 °C and a concentration of 8 wt% for 24 h to form mesopores with a pore size of 2-5 nm, and the oxalate root and zeolite framework Al 3+Form a stable five-membered ring chelate, which can serve as a CO2 adsorption site and an Fe 2+ binding site.

[0010] Based on this, a preferred method for preparing a CO2 loading material is obtained, including the following steps: Step a1: Place natural zeolite in an oxalic acid solution with a temperature of 60 °C and a concentration of 2 wt% for 1 h, filter and transfer it to an oxalic acid solution with a temperature of 80 °C and a concentration of 5 wt% for 2 h, filter and transfer it to an oxalic acid solution with a temperature of 25 °C and a concentration of 8 wt% for 24 h, filter and take it out to air dry to obtain acidified zeolite; Step a2: In a reaction kettle, immerse the acidified zeolite in an ethanol solution of FeCl2·4H2O with a concentration of 0.5 mol / L, evacuate to -0.08 MPa, oscillate for 30 min, filter and take it out and place it in an oven, dry at 60 °C for 1 h, place it in a sintering furnace, and calcine at 350 °C for 1 h in a nitrogen atmosphere to obtain a modified zeolite precursor; Step a3: In an ultrasonic mixer, place the modified zeolite precursor in an ethanol solution of carbon quantum dots with a concentration of 2 mg / mL and ultrasonically treat it at 40 Hz for 25 min. After completion, take it out and cure it at 120 °C for 10 min, then place it in an ethanol solution of tetraethyl orthosilicate with a concentration of 10 wt% and ultrasonically treat it at 40 Hz for 15 min. After completion, take it out and cure it at 120 °C for 10 min to obtain modified zeolite; Step a4: Place the modified zeolite in an adsorber, introduce a CO2 atmosphere with a concentration of 75%, first adsorb at 0.8 MPa for 30 min, and then reduce the pressure to 0.1 MPa and adsorb for 1 h to obtain a CO2 loading material.

[0011] Furthermore, the gel material is a mixture of cement and mineral admixtures; Preferably, the mass ratio of the cement to the mineral admixture is (18 - 20):(3 - 5).

[0012] Furthermore, the cement is a mixture of any one or more of Portland cement, sulfoaluminate cement, and aluminate cement in any proportion; Preferably, the cement is a mixture of Portland cement and sulfoaluminate cement in a mass ratio of 1:1.

[0013] Furthermore, the mineral admixture is a mixture of any one or more of fly ash, ground granulated blast furnace slag, silica fume, steel slag powder, gypsum powder, and limestone powder in any proportion; Preferably, the mineral admixture is fly ash.

[0014] Furthermore, the fine aggregate is a mixture of any one or two of natural sand and manufactured sand in any proportion; Preferably, the fine aggregate is natural sand.

[0015] Furthermore, the coarse aggregate is a mixture composed of any one or two of crushed stone, pebbles, and recycled aggregate in any proportion; Preferably, the coarse aggregate is pebbles.

[0016] Furthermore, the admixture is a polycarboxylate water reducer.

[0017] In a second aspect, the present invention also discloses a preparation method of the high-performance concrete as described above, comprising the following steps: Step 1: Mix the cementitious material, fine aggregate, and coarse aggregate evenly to obtain mixture 1; Step 2: Mix the admixture and water evenly and then add them to mixture 1 and continue stirring for 120 s to obtain mixture 2; Step 3: Add the CO2 carrier to mixture 2, heat up to 45 °C and continue stirring for 20 - 30 s, and then let it stand for 60 seconds to obtain mixture 3; Step 4: Pour mixture 3 into a mold and obtain a high-performance concrete product after natural air drying.

[0018] Advantages of the present invention: (1) In the preparation process of the high-performance concrete product of the present invention, a CO2 carrier is added. During the preparation process, the CO2 carrier is first subjected to gradient pickling with oxalic acid solution to form micropores and mesopores of different sizes. Among them, the micropores retain the characteristics of zeolite molecular sieve, and the mesopores retain the oxalate aluminum chelate as the CO2 adsorption site and the Fe 2+ binding site. Then it is treated in an ethanol solution of FeCl2·4H2O, so that Fe 2+ binds with the oxalate aluminum chelate to form an Fe-OOC-Al structure, which has a stronger adsorption capacity for CO2; then a carbon quantum dot layer and an SiO2 nanoporous layer are successively plated in the mesopores. Among them, the carbon quantum dot layer can generate local high temperature when generating frictional heat during the stirring process of concrete preparation, promoting the breakage of the Fe-CO2 coordination bond and facilitating the release of CO2, while the SiO2 nanoporous layer protects the carbon quantum dot layer and allows the release of CO2. Therefore, the adsorbed CO2 can be released efficiently and completely. The released CO2 reacts with the cementitious material to form carbonation products calcium carbonate and silica gel, which is beneficial to the mineralization curing during the concrete preparation process, and thus can improve the mechanical properties of the concrete and reduce its porosity.

[0019] (2) The above CO2 carrier adopts a two-step adsorption method when adsorbing CO2. First, it adsorbs at 0.8 MPa to quickly saturate the CO2 in the zeolite mesopores, and then reduces the pressure to 0.1 MPa to maintain equilibrium adsorption, which can achieve full filling of the mesopores and further enhance the CO2 adsorption capacity.

[0020] (3) The high-performance concrete of the present invention can reduce the energy consumption and shorten the curing time brought by autoclave curing of high-performance concrete, reduce the production cost, has a simple process, and can improve the production efficiency. Description of the Drawings

[0021] The present invention will be further described below in conjunction with the drawings.

[0022] Figure 1 It is the SEM characterization diagram of the surface morphology of the CO2 loading obtained in Preparation Example 1 of the present invention; Figure 2 It is the SEM characterization diagram of the surface morphology of the CO2 loading obtained in Comparative Preparation Example 1 of the present invention; Figure 3 It is the SEM characterization diagram of the surface morphology of the high-performance concrete obtained in Example 1 of the present invention; Figure 4 It is the SEM characterization diagram of the surface morphology of the high-performance concrete obtained in Comparative Example 1 of the present invention. Detailed Description of the Invention

[0023] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative work shall fall within the protection scope of the present invention.

[0024] The terms used in the embodiments of the present application are only for the purpose of describing specific embodiments, and are not intended to limit the present application. The singular forms of "a", "the" and "said" used in the embodiments of the present application and the appended claims are also intended to include the plural forms unless the context clearly indicates otherwise.

[0025] It should be understood that in various embodiments of the present application, the magnitude of the sequence numbers of the various processes does not mean the order of execution. Some or all of the steps can be executed in parallel or successively. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation to the implementation process of the embodiments of the present application.

[0026] The weights of the relevant components mentioned in the specification of the embodiments of the present application not only can refer to the specific contents of the components, but also can represent the proportional relationship of the weights between the components. Therefore, as long as the contents of the relevant components in the specification of the embodiments of the present application are enlarged or reduced in proportion, they are within the scope disclosed in the specification of the embodiments of the present application. Specifically, the mass described in the specification of the embodiments of the present application can be mass units well-known in the chemical industry such as μg, mg, g, kg, etc.

[0027] Unless otherwise defined, all technical terms used hereinafter have the same meaning as commonly understood by those skilled in the art. The technical terms used herein are for the purpose of describing specific embodiments only and are not intended to limit the scope of protection of the present invention.

[0028] The experimental methods in the following examples are all conventional methods unless otherwise specified, and are carried out according to the techniques or conditions described in the literature in this field or according to the product specifications. The materials, reagents, etc. used in the following examples can be obtained from commercial sources unless otherwise specified; the parts by weight involved in the following examples are such that 1 part = 1 kg.

[0029] Preparation Example 1

[0030] To prepare a CO₂-loaded material, the following steps are carried out in sequence: Step a1: Place natural zeolite in an oxalic acid solution with a temperature of 60 °C and a concentration of 2 wt% for 1 h, filter and transfer it to an oxalic acid solution with a temperature of 80 °C and a concentration of 5 wt% for 2 h, filter and transfer it to an oxalic acid solution with a temperature of 25 °C and a concentration of 8 wt% for 24 h, filter and take out, and air-dry for 24 h to obtain acidified zeolite; Step a2: In a reaction kettle, immerse the acidified zeolite in an ethanol solution of FeCl₂·4H₂O with a concentration of 0.5 mol / L, evacuate to -0.08 MPa, oscillate for 30 min, filter and take out, place in an oven, dry at 60 °C for 1 h, place in a sintering furnace, and calcine at 350 °C in a nitrogen atmosphere for 1 h to obtain a modified zeolite precursor; Step a3: In an ultrasonic mixer, place the modified zeolite precursor in a carbon quantum dot ethanol solution with a concentration of 2 mg / mL and perform ultrasonic treatment at 40 Hz for 25 min. After completion, take it out and cure at 120 °C for 10 min, then place it in a tetraethyl orthosilicate ethanol solution with a concentration of 10 wt% and perform ultrasonic treatment at 40 Hz for 15 min. After completion, take it out and cure at 120 °C for 10 min to obtain modified zeolite; Step a4: Place the modified zeolite in an adsorber, introduce a CO₂ atmosphere with a concentration of 75%, first adsorb at 0.8 MPa for 30 min, then reduce the pressure to 0.1 MPa and adsorb for 1 h to obtain a CO₂-loaded material. The SEM characterization diagram of its surface morphology is as Figure 1 shown. By observing Figure 1 it can be found that its pore structure is uniform and the porosity is high.

[0031] Preparation Example 2

[0032] To prepare a CO₂ adsorbent, compared with Preparation Example 1, the only difference is that in step a3, the sonication time in the carbon quantum dot ethanol solution is changed to 20 min, and at the same time, the sonication time in the tetraethyl orthosilicate ethanol solution is changed to 10 min. Other steps and conditions remain the same, and finally a CO₂ adsorbent is obtained.

[0033] Preparation Example 3

[0034] To prepare a CO₂ adsorbent, compared with Preparation Example 1, the only difference is that in step a3, the sonication time in the carbon quantum dot ethanol solution is changed to 30 min, and at the same time, the sonication time in the tetraethyl orthosilicate ethanol solution is changed to 20 min. Other steps and conditions remain the same, and finally a CO₂ adsorbent is obtained.

[0035] Comparative Preparation Example 1

[0036] To prepare a CO₂ adsorbent, compared with Preparation Example 1, the only difference is that in step a1: natural zeolite is treated with an oxalic acid solution at a temperature of 80 °C and a concentration of 5 wt% for 27 h, filtered and taken out, and then air-dried for 24 h to obtain acidified zeolite; other steps and conditions remain the same, and finally a CO₂ adsorbent is obtained. The SEM characterization diagram of its surface morphology is as Figure 2 shown. By observing Figure 2 , it can be found that compared with the Figure 1 CO₂ adsorbent, the uniformity of its pore structure is significantly worse, and the porosity is significantly reduced.

[0037] Comparative Preparation Example 2

[0038] To prepare a CO₂ adsorbent, compared with Preparation Example 1, the only difference is that in step a2: in a reaction kettle, the acidified zeolite is placed in a sintering furnace and calcined at 350 °C for 1 h in a nitrogen atmosphere to obtain a modified zeolite precursor; other steps and conditions remain the same, and finally a CO₂ adsorbent is obtained.

[0039] Comparative Preparation Example 3

[0040] To prepare a CO₂ adsorbent, compared with Preparation Example 1, the only difference is that in step a3: in an ultrasonic mixer, the modified zeolite precursor is placed in a carbon quantum dot ethanol solution with a concentration of 2 mg / mL and sonicated at 40 Hz for 25 min, then taken out and cured at 120 °C for 10 min to obtain modified zeolite; other steps and conditions remain the same, and finally a CO₂ adsorbent is obtained.

[0041] Comparative Preparation Example 4

[0042] To prepare the CO₂ adsorbent, compared with Preparation Example 1, the difference is only that in step a3: in an ultrasonic mixer, the modified zeolite precursor is placed in a tetraethyl orthosilicate ethanol solution with a concentration of 10 wt% and ultrasonically treated at 40 Hz for 15 min, and then taken out and cured at 120 °C for 10 min to obtain the modified zeolite; the conditions of other steps remain the same, and finally the CO₂ adsorbent is prepared.

[0043] Comparative Preparation Example 5

[0044] To prepare the CO₂ adsorbent, compared with Preparation Example 1, the difference is only that step a3 is cancelled; the conditions of other steps remain the same, and finally the CO₂ adsorbent is prepared.

[0045] Comparative Preparation Example 6

[0046] To prepare the CO₂ adsorbent, compared with Preparation Example 1, the difference is only that in step a4: the modified zeolite is placed in an adsorber, and a CO₂ atmosphere with a concentration of 75% is introduced, and adsorbed at 0.1 MPa for 1.5 h to obtain the CO₂ adsorbent.

[0047] Perform performance tests on the CO₂ adsorbents of the above Preparation Examples 1-3 and Comparative Preparation Examples 1-6 for the CO₂ adsorption capacity. The test method refers to the standard method of GB / T 35208-2017, and the test results are listed in Table 1 as follows: Table 1

[0048] By analyzing the data in Table 1, it can be known that compared with Comparative Preparation Examples 1-6, the CO₂ adsorbents prepared in Preparation Examples 1-3 have a higher CO₂ adsorption capacity.

[0049] Example 1

[0050] To prepare high-performance concrete, the following steps are carried out in sequence: Step 1: Prepare 18 parts of portland cement, 18 parts of sulfoaluminate cement, 6 parts of fly ash, 6 parts of the CO₂ adsorbent prepared in Preparation Example 1, 70 parts of natural sand, 95 parts of pebbles, 1 part of polycarboxylate water reducer, and 15 parts of water by weight.

[0051] Step 2: Mix the cementitious materials, fine aggregates, and coarse aggregates evenly to obtain mixture 1; Step 3: Mix the admixture and water evenly and then add them to mixture 1 and continue stirring for 120 s to obtain mixture 2; Step 4: Add the CO₂ adsorbent to mixture 2, heat up to 45 °C and continue stirring for 25 s, and then let it stand for 60 seconds to obtain mixture 3; Step 5: Pour mixture 3 into a mold and air-dry naturally to obtain a high-performance concrete product, and the SEM characterization diagram of its surface morphology is asFigure 3 As shown, by observing Figure 3 , it can be found that a large amount of calcium carbonate is generated on its surface.

[0052] Example 2

[0053] To prepare high-performance concrete, the following steps are carried out in sequence: Step 1: Prepare 15 parts of Portland cement, 15 parts of sulfoaluminate cement, 5 parts of fly ash, 2 parts of the CO2 adsorbent prepared in Preparation Example 1, 60 parts of natural sand, 70 parts of pebbles, 0.5 part of polycarboxylate water reducer, and 13 parts of water by weight.

[0054] Step 2: Mix the cementitious materials, fine aggregates, and coarse aggregates evenly to obtain mixture 1; Step 3: Mix the admixture and water evenly and then add them to mixture 1 and continue stirring for 120 s to obtain mixture 2; Step 4: Add the CO2 adsorbent to mixture 2, heat up to 45 °C and continue stirring for 25 s, and then let it stand for 60 seconds to obtain mixture 3; Step 5: Pour mixture 3 into a mold and let it air-dry naturally to obtain a high-performance concrete product.

[0055] Example 3

[0056] To prepare high-performance concrete, the following steps are carried out in sequence: Step 1: Prepare 20 parts of Portland cement, 20 parts of sulfoaluminate cement, 10 parts of fly ash, 10 parts of the CO2 adsorbent prepared in Preparation Example 1, 80 parts of natural sand, 120 parts of pebbles, 2 parts of polycarboxylate water reducer, and 17 parts of water by weight.

[0057] Step 2: Mix the cementitious materials, fine aggregates, and coarse aggregates evenly to obtain mixture 1; Step 3: Mix the admixture and water evenly and then add them to mixture 1 and continue stirring for 120 s to obtain mixture 2; Step 4: Add the CO2 adsorbent to mixture 2, heat up to 45 °C and continue stirring for 25 s, and then let it stand for 60 seconds to obtain mixture 3; Step 5: Pour mixture 3 into a mold and let it air-dry naturally to obtain a high-performance concrete product.

[0058] Example 4

[0059] To prepare high-performance concrete, compared with Example 1, the difference is only that the CO2 adsorbent prepared in Preparation Example 1 is replaced by the CO2 adsorbent prepared in Preparation Example 2, and other steps and conditions remain the same, and finally a high-performance concrete product is obtained.

[0060] Example 5

[0061] To prepare high-performance concrete, compared with Example 1, the only difference is that the CO2 loading obtained in Preparation Example 1 is replaced with the CO2 loading obtained in Preparation Example 3, and other steps and conditions remain the same, and finally a high-performance concrete product is obtained.

[0062] Comparative Example 1

[0063] To prepare high-performance concrete, compared with Example 1, the only difference is that the CO2 loading obtained in Preparation Example 1 is replaced with the CO2 loading obtained in Comparative Preparation Example 1, and other steps and conditions remain the same, and finally a high-performance concrete product is obtained. The SEM characterization diagram of its surface morphology is as Figure 4 shown. By observing Figure 4 , it can be found that compared with the high-performance concrete product of Figure 3 , the amount of calcium carbonate formed on its surface is significantly reduced.

[0064] Comparative Example 2

[0065] To prepare high-performance concrete, compared with Example 1, the only difference is that the CO2 loading obtained in Preparation Example 1 is replaced with the CO2 loading obtained in Comparative Preparation Example 2, and other steps and conditions remain the same, and finally a high-performance concrete product is obtained.

[0066] Comparative Example 3

[0067] To prepare high-performance concrete, compared with Example 1, the only difference is that the CO2 loading obtained in Preparation Example 1 is replaced with the CO2 loading obtained in Comparative Preparation Example 3, and other steps and conditions remain the same, and finally a high-performance concrete product is obtained.

[0068] Comparative Example 4

[0069] To prepare high-performance concrete, compared with Example 1, the only difference is that the CO2 loading obtained in Preparation Example 1 is replaced with the CO2 loading obtained in Comparative Preparation Example 4, and other steps and conditions remain the same, and finally a high-performance concrete product is obtained.

[0070] Comparative Example 5

[0071] To prepare high-performance concrete, compared with Example 1, the only difference is that the CO2 loading obtained in Preparation Example 1 is replaced with the CO2 loading obtained in Comparative Preparation Example 5, and other steps and conditions remain the same, and finally a high-performance concrete product is obtained.

[0072] Comparative Example 6

[0073] To prepare high-performance concrete, compared with Example 1, the only difference is that the CO2 loading obtained in Preparation Example 1 is replaced with the CO2 loading obtained in Comparative Preparation Example 6, and other steps and conditions remain the same, and finally a high-performance concrete product is obtained.

[0074] Performance tests were carried out on the high-performance concrete products prepared in Examples 1-5 and Comparative Examples 1-6, including compressive strength tests and porosity tests. The test methods were as follows: Compressive strength: Refer to the standard method of GB / T 50081-2019; Porosity: Refer to the standard method of ASTM D4404-18.

[0075] The test results are listed in Table 2 as follows: Table 2

[0076] By analyzing the data in Table 2, it can be known that compared with Comparative Examples 1-6, the high-performance concrete prepared in Examples 1-5 has significantly stronger compressive strength and lower porosity. This shows that the mineralization effect of the high-performance concrete in Examples 1-5 is stronger, corresponding to the test results of the CO2 load in Table 1, indicating that the CO2 load in the high-performance concrete of the present invention plays a key role in the performance of the concrete.

[0077] The above has described in detail a plurality of embodiments of the present invention, but the content described is only the preferred embodiments of the present invention and cannot be considered as limiting the scope of implementation of the present invention. Any equivalent changes and improvements made within the scope of the application of the present invention should still fall within the scope covered by the patent of the present invention.

Claims

1. A high-performance concrete, characterized in that, Comprising the following components by weight parts: 35 - 50 parts of gel material, 2 - 10 parts of CO₂ loading, 60 - 80 parts of fine aggregate, 70 - 120 parts of coarse aggregate, 0.5 - 2 parts of admixture, 13 - 17 parts of water; Wherein, the CO₂ loading is modified zeolite loaded with CO₂ gas; The preparation method of the CO₂ loading comprises the following steps: Step A1: Place natural zeolite in an oxalic acid solution for gradient acidification treatment to obtain acidified zeolite; Step A2: Immerse the acidified zeolite in an ethanol solution of FeCl₂·4H₂O with a concentration of 0.5 mol / L, evacuate to -0.08 MPa, oscillate for 30 min, filter and take out, then dry, and calcine in a nitrogen atmosphere at 350 °C for 1 h to obtain a modified zeolite precursor; Step A3: Place the modified zeolite precursor in an ethanol solution of carbon quantum dots with a concentration of 2 mg / mL and ultrasonically treat for 20 - 30 min. After completion, take out and cure at 120 °C for 10 min, then place in an ethanol solution of tetraethyl orthosilicate with a concentration of 10 wt% and ultrasonically treat for 10 - 20 min. After completion, take out and cure at 120 °C for 10 min to obtain modified zeolite; Step A4: Place the modified zeolite in a CO₂ atmosphere with a concentration of 70% - 80%. First, adsorb at 0.8 MPa for 30 min, then reduce the pressure to 0.1 MPa and adsorb for 1 h to obtain the CO₂ loading.

2. The high-performance concrete according to claim 1, wherein The gradient acidification treatment includes three steps, namely: The first step: Place natural zeolite in an oxalic acid solution at a temperature of 60 °C and a concentration of 2 wt% and treat for 1 h; The second step: After filtration, transfer to an oxalic acid solution at a temperature of 80 °C and a concentration of 5 wt% and treat for 2 h; The third step: After filtration, transfer to an oxalic acid solution at a temperature of 25 °C and a concentration of 8 wt% and treat for 24 h.

3. The high-performance concrete according to claim 1, wherein The gel material is a mixture of cement and mineral admixture.

4. The high-performance concrete according to claim 3, wherein, The cement is a mixture composed of any one or more of portland cement, sulfoaluminate cement, and aluminate cement in any proportion.

5. The high-performance concrete according to claim 3, wherein The mineral admixture is a mixture composed of any one or more of fly ash, ground granulated blast furnace slag, silica fume, steel slag powder, gypsum powder, and limestone powder in any proportion.

6. The high-performance concrete according to claim 1, characterized in that, The fine aggregate is a mixture composed of any one or two of natural sand and manufactured sand in any proportion.

7. The high-performance concrete according to claim 1, wherein The coarse aggregate is a mixture composed of any one or two of crushed stone, pebble, and recycled aggregate in any proportion.

8. The high-performance concrete according to claim 1, wherein, The admixture is a polycarboxylate water reducer.

9. A method for preparing a high-performance concrete according to any one of claims 1-8, characterized in that, Including the following steps: Step one: Mix the gelling material, fine aggregate, and coarse aggregate evenly to obtain mixture 1; Step two: Mix the admixture and water evenly and then add them to mixture 1 and continue to stir for 120 s to obtain mixture 2; Step three: Add the CO₂ loading to mixture 2, heat up to 45 °C and continue to stir for 20 - 30 s, then stand for 60 seconds to obtain mixture 3; Step four: Pour mixture 3 into a mold and air dry naturally to obtain a high-performance concrete product.

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