High performance concrete and preparation method thereof

Abstract

The present invention discloses a high-performance concrete and a preparation method thereof, which relates to the field of concrete technology. The high-performance concrete comprises the following components: a gel material, a CO2 loading substance, fine aggregate, coarse aggregate, an admixture, and water. During the preparation process, the CO2 loading substance is first subjected to gradient pickling with an oxalic acid solution to form micropores and mesopores of different sizes, wherein the mesopores retain aluminum oxalate chelates as CO2 adsorption sites and Fe 2+ binding site, making Fe 2+ It combines with aluminum oxalate chelate to form a Fe‑OOC‑Al structure, which has a stronger adsorption capacity for CO2; then a carbon quantum dot layer is plated in the mesopores. When the carbon quantum dot layer generates friction heat during the mixing process of concrete preparation, it can generate local high temperature, promote the breaking of Fe‑CO2 coordination bonds, and facilitate the release of CO2. The released CO2 reacts with the cementitious material to form carbonization products calcium carbonate and silica gel, which is beneficial to the mineralization and curing during the concrete preparation process, thereby improving the mechanical properties of the concrete and reducing its porosity.

Description

Technical Field

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

[0002] Carbonation curing, as an environmentally friendly, integrated technology, simultaneously achieves the dual goals of greenhouse gas sequestration and building material performance optimization. By converting carbon dioxide into a stable carbonate form during the initial hydration reaction, this technology not only achieves carbon sequestration but also significantly improves the initial mechanical properties and structural density of the cement matrix, thereby enhancing its durability in harsh service environments. Compared to traditional steam curing or high-temperature water curing processes, this technology exhibits significant energy-saving advantages, and has therefore attracted considerable attention from academia and engineering communities amid the global low-carbon transition.

[0003] The core of carbonation curing is the chemical reaction of CO2 with alkaline substances such as calcium hydroxide (Ca(OH)2) and calcium silicate in cement-based materials, producing calcium carbonate (CaCO3) and water. This process not only stabilizes the CO2 within the material but also fills the pores within the material through the formation of calcium carbonate, thereby increasing the material's density and strength. Specifically, carbonation curing accelerates the hydration reaction of cement and significantly improves early strength. For example, at three days of age, carbonation curing can increase concrete strength by over 20%. The formation of calcium carbonate fills the pores within the material, reducing porosity and improving impermeability and durability. Carbonation curing converts soluble calcium hydroxide into stable calcium carbonate, minimizing mass and strength loss in corrosive environments. Therefore, carbonation curing can be an alternative to traditional accelerated curing techniques such as steam curing and high-temperature water curing, significantly reducing energy consumption. For example, carbonation curing can be carried out at room temperature and pressure, eliminating the need for 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, bringing it to the level of original aggregate concrete; carbonation curing is also suitable for large-volume projects (such as dams and foundations), by increasing early strength and reducing the risk of cracks.

[0004] However, it is worth noting that the current carbonation curing technology still has several key bottlenecks: first, the depth of carbon dioxide reaction is limited to the surface area of ​​the material, resulting in limited carbon sequestration efficiency, which affects the effect of mineralization curing during concrete preparation; second, the existing process relies on high-pressure reaction conditions, which limits its direct application on engineering sites. Summary of the Invention

[0005] The purpose of the present invention is to provide a high performance concrete and a preparation method thereof to solve the following technical problems:

[0006] How to improve the effect of carbon dioxide mineralization curing during concrete preparation.

[0007] The purpose of the present invention can be achieved through the following technical solutions:

[0008] In a first aspect, the present invention discloses a high-performance concrete comprising the following components in parts by weight: 35-50 parts of a gel material, 2-10 parts of a CO2 loading substance, 60-80 parts of a fine aggregate, 70-120 parts of a coarse aggregate, 0.5-2 parts of an admixture, and 13-17 parts of water;

[0009] Preferably, the mixture comprises the following components in parts by weight: 42 parts of gel material, 6 parts of CO2 loading material, 70 parts of fine aggregate, 95 parts of coarse aggregate, 1 part of admixture, and 15 parts of water.

[0010] Wherein, the CO2 load is a modified zeolite loaded with CO2 gas;

[0011] The preparation method of the CO2 loading material comprises the following steps:

[0012] Step A1, placing natural zeolite in an oxalic acid solution for gradient acidification to obtain acidified zeolite;

[0013] Step A2, immersing the acidified zeolite in a 0.5 mol / L FeCl2·4H2O ethanol solution, evacuating to -0.08 MPa, shaking for 30 min, filtering out, drying, and calcining at 350°C in a nitrogen atmosphere for 1 h to obtain a modified zeolite precursor;

[0014] Step A3, placing the modified zeolite precursor in a 2 mg / mL carbon quantum dot ethanol solution and ultrasonically treating it for 20-30 minutes, then taking it out and curing it at 120°C for 10 minutes to form a carbon quantum dot layer, and then placing it in a 10 wt% ethyl orthosilicate ethanol solution and ultrasonically treating it for 10-20 minutes, then taking it out and curing it at 120°C for 10 minutes to form a SiO2 nanoporous layer to obtain a modified zeolite;

[0015] Step A4: Place the modified zeolite in a CO2 atmosphere with a concentration of 70%-80%, first adsorb at 0.8 MPa for 30 minutes, then reduce the pressure to 0.1 MPa and adsorb for 1 hour to obtain a CO2 loaded substance.

[0016] Furthermore, the gradient acidification treatment includes three steps, namely:

[0017] The first step is to place the natural zeolite in a 2 wt% oxalic acid solution at 60°C for 1 hour to remove impurities such as Mg and Ca.

[0018] The second step is to transfer the filtered product to a 5 wt% oxalic acid solution at 80°C for 2 hours to form micropores with a pore size of 0.5-1 nm and retain the molecular sieve properties of the zeolite.

[0019] The third step is to transfer the filtered water into an oxalic acid solution with a temperature of 25°C and a concentration of 8 wt% for 24 hours to form mesopores with a pore size of 2-5 nm and the oxalate radicals are bonded to the zeolite framework Al 3+ Forming a stable five-membered ring chelate, which can serve as a CO2 adsorption site and Fe 2+ Binding site.

[0020] Based on this, a preferred method for preparing a CO2-loaded material is obtained, comprising the following steps:

[0021] Step a1, placing the natural zeolite in a 2 wt% oxalic acid solution at 60°C for 1 hour, filtering and then transferring it to a 5 wt% oxalic acid solution at 80°C for 2 hours, filtering and then transferring it to an 8 wt% oxalic acid solution at 25°C for 24 hours, filtering and then air-drying to obtain the acidified zeolite;

[0022] Step a2: In a reaction kettle, the acidified zeolite was immersed in a 0.5 mol / L FeCl2·4H2O ethanol solution, evacuated to -0.08 MPa, shaken for 30 min, filtered out, placed in an oven, dried at 60°C for 1 h, placed in a sintering furnace, and calcined at 350°C for 1 h in a nitrogen atmosphere to obtain a modified zeolite precursor;

[0023] Step a3, in an ultrasonic mixer, the modified zeolite precursor was placed in a 2 mg / mL carbon quantum dot ethanol solution and ultrasonically treated at 40 Hz for 25 min, then taken out and cured at 120° C. for 10 min, and then placed in a 10 wt% ethyl orthosilicate ethanol solution and ultrasonically treated at 40 Hz for 15 min, and then taken out and cured at 120° C. for 10 min to obtain a modified zeolite;

[0024] 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 minutes, then reduce the pressure to 0.1 MPa and adsorb for 1 hour to obtain a CO2 loaded substance.

[0025] Furthermore, the gel material is a mixture of cement and mineral admixtures;

[0026] Preferably, the mass ratio of the cement to the mineral admixture is (18-20):(3-5).

[0027] Furthermore, the cement is any one of silicate cement, sulphoaluminate cement and aluminate cement or a mixture of any two or more thereof in any proportion;

[0028] Preferably, the cement is a mixture of Portland cement and sulphoaluminate cement in a mass ratio of 1:1.

[0029] Furthermore, the mineral admixture is any one of fly ash, slag powder, silica fume, steel slag powder, gypsum powder, and limestone powder, or a mixture of any two or more thereof in any proportion;

[0030] Preferably, the mineral admixture is fly ash.

[0031] Furthermore, the fine aggregate is any one of natural sand and machine-made sand, or a mixture of the two in any proportion;

[0032] Preferably, the fine aggregate is natural sand.

[0033] Furthermore, the coarse aggregate is any one of crushed stone, pebbles, and recycled aggregate, or a mixture of two of them in any proportion;

[0034] Preferably, the coarse aggregate is pebbles.

[0035] Furthermore, the admixture is a polycarboxylate water reducer.

[0036] In a second aspect, the present invention further discloses a method for preparing the high performance concrete as described above, comprising the following steps:

[0037] Step 1: Evenly mix the cementitious material, fine aggregate, and coarse aggregate to obtain a mixture 1;

[0038] Step 2: Mix the admixture and water evenly, add them to the mixture 1, and continue stirring for 120 seconds to obtain the mixture 2;

[0039] Step 3: Add the CO2 loading substance to the mixture 2, heat it to 45°C and continue stirring for 20-30 seconds, then let it stand for 60 seconds to obtain the mixture 3;

[0040] Step 4: pouring the mixture 3 into a mold and allowing it to dry naturally to obtain a high-performance concrete product.

[0041] Beneficial effects of the present invention:

[0042] (1) The high performance concrete product of the present invention is added with a CO2 loading material during the preparation process. During the preparation process, the CO2 loading material is first subjected to gradient acid washing with an oxalic acid solution to form micropores and mesopores of different sizes, wherein the micropores retain the characteristics of the zeolite molecular sieve, and the mesopores retain the aluminum oxalate chelate as a CO2 adsorption site and Fe 2+ The binding site was then treated in FeCl2·4H2O ethanol solution to make Fe 2+It combines with aluminum oxalate chelate to form a Fe-OOC-Al structure, which has a stronger adsorption capacity for CO2; then a carbon quantum dot layer and a SiO2 nanoporous layer are sequentially plated in the mesopores. Among them, the carbon quantum dot layer can generate local high temperature when friction heat is generated during the stirring process of concrete preparation, promotes the breaking of Fe-CO2 coordination bonds, and is beneficial to the release of CO2, while the SiO2 nanoporous layer protects the carbon quantum dot layer and allows CO2 to be released, so the adsorbed CO2 can be released efficiently and completely. The released CO2 reacts with the cementitious material to form carbonization products calcium carbonate and silica gel, which is beneficial to the mineralization and maintenance during the concrete preparation process, thereby improving the mechanical properties of the concrete and reducing its porosity.

[0043] (2) The above-mentioned CO2 load 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.

[0044] (3) The high-performance concrete of the present invention can reduce the energy consumption caused by the autoclaving of high-performance concrete and shorten the curing time, thereby reducing production costs, simplifying the process, and improving production efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] The present invention will be further described below with reference to the accompanying drawings.

[0046] Figure 1 This is a SEM characterization image of the surface morphology of the CO2 load obtained in Preparation Example 1 of the present invention;

[0047] Figure 2 This is a SEM characterization image of the surface morphology of the CO2 load obtained in Comparative Preparation Example 1 of the present invention;

[0048] Figure 3 is a SEM characterization image of the surface morphology of the high performance concrete prepared in Example 1 of the present invention;

[0049] Figure 4 This is a SEM characterization image of the surface morphology of the high performance concrete prepared in Comparative Example 1 of the present invention. DETAILED DESCRIPTION

[0050] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts shall fall within the scope of protection of the present invention.

[0051] The terms used in the examples of this application are for the purpose of describing specific implementation rules only and are not intended to limit this application. The singular forms "a", "an", "the" and "the" used in the implementation rules of this application and the appended claims are also intended to include the plural forms unless the context clearly indicates otherwise.

[0052] It should be understood that in the various embodiments of the present application, the size of the serial number of each process does not mean the order of execution. Some or all steps can be executed in parallel or sequentially. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the implementation regulations of this application.

[0053] The weights of the relevant components mentioned in the examples of this application may not only refer to the specific content of each component, but also represent the weight ratio between the components. Therefore, as long as the content of the relevant components is proportionally enlarged or reduced according to the examples of this application, it is within the scope disclosed in the examples of this application. Specifically, the mass described in the examples of this application may be a mass unit known in the chemical industry, such as μg, mg, g, kg, etc.

[0054] Unless otherwise defined, all technical terms used hereinafter have the same meanings as those generally understood by those skilled in the art. The technical terms used herein are only for the purpose of describing specific embodiments and are not intended to limit the scope of protection of the present invention.

[0055] Unless otherwise noted, the experimental methods in the following examples are conventional methods and were performed according to the techniques or conditions described in literature in the field or according to product specifications. Materials and reagents used in the following examples were commercially available unless otherwise noted. References to parts by weight in the following examples refer to 1 part = 1 kg.

[0056] Preparation Example 1

[0057] Prepare the CO2 load according to the following steps:

[0058] Step a1, placing the natural zeolite in a 2 wt% oxalic acid solution at 60°C for 1 hour, filtering and then transferring it to a 5 wt% oxalic acid solution at 80°C for 2 hours, filtering and then transferring it to an 8 wt% oxalic acid solution at 25°C for 24 hours, filtering and then air-drying it for 24 hours to obtain an acidified zeolite;

[0059] Step a2: In a reaction kettle, the acidified zeolite was immersed in a 0.5 mol / L FeCl2·4H2O ethanol solution, evacuated to -0.08 MPa, shaken for 30 min, filtered out, placed in an oven, dried at 60°C for 1 h, placed in a sintering furnace, and calcined at 350°C for 1 h in a nitrogen atmosphere to obtain a modified zeolite precursor;

[0060] Step a3, in an ultrasonic mixer, the modified zeolite precursor was placed in a 2 mg / mL carbon quantum dot ethanol solution and ultrasonically treated at 40 Hz for 25 min, then taken out and cured at 120° C. for 10 min, and then placed in a 10 wt% ethyl orthosilicate ethanol solution and ultrasonically treated at 40 Hz for 15 min, and then taken out and cured at 120° C. for 10 min to obtain a modified zeolite;

[0061] Step a4: Place the modified zeolite in an adsorber, introduce a 75% CO2 atmosphere, 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 load. The SEM characterization of its surface morphology is shown in the figure below. Figure 1 As shown, through Figure 1 Through observation, it can be found that its pore structure is uniform and the porosity is high.

[0062] Preparation Example 2

[0063] The CO2 load was prepared in accordance with Preparation Example 1, except that, in step a3, the ultrasonic treatment time in the carbon quantum dot ethanol solution was changed to 20 min, and the ultrasonic treatment time in the ethyl orthosilicate ethanol solution was changed to 10 min. The other steps and conditions remained the same, and the CO2 load was finally obtained.

[0064] Preparation Example 3

[0065] The CO2 load was prepared in accordance with Preparation Example 1, except that, in step a3, the ultrasonic treatment time in the carbon quantum dot ethanol solution was changed to 30 min, and the ultrasonic treatment time in the ethyl orthosilicate ethanol solution was changed to 20 min. The other steps and conditions remained the same, and the CO2 load was finally obtained.

[0066] Comparative Preparation Example 1

[0067] Preparation of CO2 loaded material, compared with Preparation Example 1, the only difference is that step a1 is: placing the natural zeolite in a 5wt% oxalic acid solution at a temperature of 80°C for 27 hours, filtering it out and air-drying it for 24 hours to obtain acidified zeolite; the other step conditions remain the same, and finally a CO2 loaded material is obtained, and its surface morphology is characterized by SEM as shown in the figure Figure 2 As shown, through Figure 2 Through observation, we can find that compared with Figure 1 The pore structure uniformity of the CO2-loaded material is significantly worse and the porosity is significantly reduced.

[0068] Comparative Preparation Example 2

[0069] The preparation of the CO2 load is different from that of Preparation Example 1 only in that step a2 is: placing the acidified zeolite in a sintering furnace in a reactor and calcining it at 350°C for 1 hour in a nitrogen atmosphere to obtain a modified zeolite precursor; the conditions of the other steps remain the same, and the CO2 load is finally obtained.

[0070] Comparative Preparation Example 3

[0071] Preparation of CO2 load, compared with Preparation Example 1, the only difference is that step a3 is: 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 ultrasonically treated at 40 Hz for 25 min. After the end, it is taken out and cured at 120°C for 10 min to obtain the modified zeolite; the conditions of the other steps remain the same, and the CO2 load is finally obtained.

[0072] Comparative Preparation Example 4

[0073] The preparation of the CO2 load is different from that in Preparation Example 1, except that step a3 is as follows: in an ultrasonic mixer, the modified zeolite precursor is placed in a 10 wt% ethyl orthosilicate ethanol solution and ultrasonically treated at 40 Hz for 15 min. After the treatment, the precursor is taken out and cured at 120°C for 10 min to obtain the modified zeolite; the other step conditions remain the same, and the CO2 load is finally obtained.

[0074] Comparative Preparation Example 5

[0075] The preparation of the CO2 loaded material is different from that of Preparation Example 1 only in that step a3 is eliminated; the conditions of other steps remain the same, and the CO2 loaded material is finally prepared.

[0076] Comparative Preparation Example 6

[0077] The preparation of the CO2 load is different from that of Preparation Example 1 only in that step a4 is: placing the modified zeolite in an adsorber, introducing a CO2 atmosphere with a concentration of 75%, and adsorbing at 0.1 MPa for 1.5 hours to obtain the CO2 load.

[0078] The CO2 loads of the above-mentioned Preparation Examples 1-3 and Comparative Preparation Examples 1-6 were subjected to a performance test of CO2 adsorption capacity. The test method was based on the GB / T 35208-2017 standard method. The test results are listed in Table 1. Table 1 is as follows:

[0079] Table 1

[0080]

[0081] By analyzing the data in Table 1, it can be seen that compared with Comparative Preparation Example 1-6, the CO2 load prepared in Preparation Example 1-3 has a higher CO2 adsorption capacity.

[0082] Example 1

[0083] To prepare high performance concrete, follow the steps below:

[0084] Step 1: Prepare, by weight, 18 parts of Portland cement, 18 parts of sulfoaluminate cement, 6 parts of fly ash, 6 parts of the CO2 load obtained in Preparation Example 1, 70 parts of natural sand, 95 parts of pebbles, 1 part of polycarboxylate water reducer, and 15 parts of water.

[0085] Step 2: Evenly mix the cementitious material, fine aggregate, and coarse aggregate to obtain a mixture 1;

[0086] Step 3: Mix the admixture and water evenly, add them to the mixture 1, and continue stirring for 120 seconds to obtain the mixture 2;

[0087] Step 4: Add the CO2 loading substance to the mixture 2, heat it to 45°C and continue stirring for 25 seconds, then let it stand for 60 seconds to obtain the mixture 3;

[0088] Step 5: Pour the mixture 3 into the mold and air dry it to obtain a high performance concrete product. The SEM characterization of its surface morphology is shown in the figure below. Figure 3 As shown, through Figure 3 Upon observation, it was found that a large amount of calcium carbonate was generated on its surface.

[0089] Example 2

[0090] To prepare high performance concrete, follow the steps below:

[0091] Step 1: Prepare, by weight, 15 parts of Portland cement, 15 parts of sulfoaluminate cement, 5 parts of fly ash, 2 parts of the CO2 load obtained in Preparation Example 1, 60 parts of natural sand, 70 parts of pebbles, 0.5 parts of polycarboxylate water reducer, and 13 parts of water.

[0092] Step 2: Evenly mix the cementitious material, fine aggregate, and coarse aggregate to obtain a mixture 1;

[0093] Step 3: Mix the admixture and water evenly, add them to the mixture 1, and continue stirring for 120 seconds to obtain the mixture 2;

[0094] Step 4: Add the CO2 loading substance to the mixture 2, heat it to 45°C and continue stirring for 25 seconds, then let it stand for 60 seconds to obtain the mixture 3;

[0095] Step 5: Pour the mixture 3 into a mold and allow it to dry naturally to obtain a high-performance concrete product.

[0096] Example 3

[0097] To prepare high performance concrete, follow the steps below:

[0098] Step 1: Prepare, by weight, 20 parts of Portland cement, 20 parts of sulfoaluminate cement, 10 parts of fly ash, 10 parts of the CO2 load obtained in Preparation Example 1, 80 parts of natural sand, 120 parts of pebbles, 2 parts of polycarboxylate water reducer, and 17 parts of water.

[0099] Step 2: Evenly mix the cementitious material, fine aggregate, and coarse aggregate to obtain a mixture 1;

[0100] Step 3: Mix the admixture and water evenly, add them to the mixture 1, and continue stirring for 120 seconds to obtain the mixture 2;

[0101] Step 4: Add the CO2 loading substance to the mixture 2, heat it to 45°C and continue stirring for 25 seconds, then let it stand for 60 seconds to obtain the mixture 3;

[0102] Step 5: Pour the mixture 3 into a mold and allow it to dry naturally to obtain a high-performance concrete product.

[0103] Example 4

[0104] The preparation of high-performance concrete is different from that of Example 1, except that the CO2 loading material prepared in Preparation Example 1 is replaced by the CO2 loading material prepared in Preparation Example 2, and the other steps and conditions remain the same, and finally a high-performance concrete product is prepared.

[0105] Example 5

[0106] The preparation of high-performance concrete is different from that of Example 1, except that the CO2 loading material prepared in Preparation Example 1 is replaced by the CO2 loading material prepared in Preparation Example 3, and the other steps and conditions remain the same, and finally a high-performance concrete product is prepared.

[0107] Comparative Example 1

[0108] Preparation of high performance concrete, compared with Example 1, the only difference is that the CO2 loading material prepared in Preparation Example 1 is replaced by the CO2 loading material prepared in Comparative Preparation Example 1, and the other steps and conditions remain the same, and finally a high performance concrete product is prepared, and its surface morphology is characterized by SEM as shown in FIG. Figure 4 As shown, through Figure 4 Through observation, we can find that compared with Figure 3 The amount of calcium carbonate generated on the surface of high-performance concrete products is significantly reduced.

[0109] Comparative Example 2

[0110] The preparation of high-performance concrete is different from that of Example 1, except that the CO2 loading material prepared in Preparation Example 1 is replaced by the CO2 loading material prepared in Comparative Preparation Example 2, and the other steps and conditions remain the same, and finally a high-performance concrete product is prepared.

[0111] Comparative Example 3

[0112] The high performance concrete was prepared in accordance with Example 1, except that the CO2 loading material prepared in Preparation Example 1 was replaced by the CO2 loading material prepared in Comparative Preparation Example 3, and the other steps and conditions remained the same, ultimately producing a high performance concrete product.

[0113] Comparative Example 4

[0114] The preparation of high-performance concrete is different from that of Example 1, except that the CO2 loading material prepared in Preparation Example 1 is replaced by the CO2 loading material prepared in Comparative Preparation Example 4, and the other steps and conditions remain the same, and finally a high-performance concrete product is prepared.

[0115] Comparative Example 5

[0116] The high performance concrete was prepared in accordance with Example 1, except that the CO2 loading material prepared in Preparation Example 1 was replaced by the CO2 loading material prepared in Comparative Preparation Example 5, and the other steps and conditions remained the same, ultimately producing a high performance concrete product.

[0117] Comparative Example 6

[0118] The preparation of high-performance concrete is different from that of Example 1, except that the CO2 loading material prepared in Preparation Example 1 is replaced by the CO2 loading material prepared in Comparative Preparation Example 6, and the other steps and conditions remain the same, and finally a high-performance concrete product is prepared.

[0119] The high performance concrete products prepared in Examples 1-5 and Comparative Examples 1-6 were subjected to performance tests, including compressive strength tests and porosity tests, using the following test methods:

[0120] Compressive strength: refer to GB / T 50081-2019 standard method;

[0121] Porosity: Refer to ASTM D4404-18 standard method.

[0122] The test results are listed in Table 2, which is as follows:

[0123] Table 2

[0124]

[0125] Analysis of the data in Table 2 shows that, compared with Comparative Examples 1-6, the high-performance concrete prepared in Examples 1-5 has significantly stronger compressive strength and lower porosity, which indicates that the high-performance concrete of Examples 1-5 has a stronger mineralization effect, which corresponds to the test results for 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.

[0126] The above describes in detail several embodiments of the present invention. However, the above contents are only preferred embodiments of the present invention and should not be considered as limiting the scope of the present invention. All equivalent changes and improvements made within the scope of the present invention should still fall within the scope of the present invention.

Claims

1. A high performance concrete, characterized in that: The components include the following in parts by weight: 35-50 parts of gel material, 2-10 parts of CO2 loading material, 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 material is a modified zeolite loaded with CO2 gas; The preparation method of the CO2 loading material comprises the following steps: Step A1, placing natural zeolite in an oxalic acid solution for gradient acidification to obtain acidified zeolite; Step A2, immersing the acidified zeolite in a 0.5 mol / L FeCl2·4H2O ethanol solution, evacuating to -0.08 MPa, shaking for 30 min, filtering out, drying, and calcining at 350°C in a nitrogen atmosphere for 1 h to obtain a modified zeolite precursor; Step A3, placing the modified zeolite precursor in a 2 mg / mL carbon quantum dot ethanol solution and ultrasonically treating it for 20-30 minutes, then taking it out and curing it at 120°C for 10 minutes, and then placing it in a 10 wt% ethyl orthosilicate ethanol solution and ultrasonically treating it for 10-20 minutes, then taking it out and curing it at 120°C for 10 minutes to obtain a modified zeolite; Step A4, placing the modified zeolite in a CO2 atmosphere with a concentration of 70%-80%, first adsorbing it at 0.8 MPa for 30 minutes, then reducing the pressure to 0.1 MPa and adsorbing it for 1 hour to obtain a CO2 loaded substance; The gradient acidification treatment includes three steps, namely: The first step is to place the natural zeolite in a 2 wt% oxalic acid solution at 60°C for 1 hour; Step 2: After filtration, transfer to 80°C 5wt% oxalic acid solution for treatment for 2h; The third step is to transfer the filtered product into an oxalic acid solution at a temperature of 25°C and a concentration of 8 wt% for treatment for 24 hours.

2. The high performance concrete according to claim 1, characterized in that The gel material is a mixture of cement and mineral admixtures.

3. The high performance concrete according to claim 2, characterized in that The cement is any one of silicate cement, sulphoaluminate cement and aluminate cement, or a mixture of any two or more of them in any proportion.

4. The high performance concrete according to claim 2, characterized in that The mineral admixture is any one of fly ash, slag powder, silica fume, steel slag powder, gypsum powder, and limestone powder, or a mixture of any multiple thereof in any proportion.

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

6. The high performance concrete according to claim 1, characterized in that The coarse aggregate is any one of crushed stone, pebble, and recycled aggregate, or a mixture of two of them in any proportion.

7. The high performance concrete according to claim 1, characterized in that The admixture is a polycarboxylate water reducer.

8. A method for preparing high performance concrete according to any one of claims 1 to 7, characterized in that: The steps include: Step 1: Evenly mix the cementitious material, fine aggregate, and coarse aggregate to obtain a mixture 1; Step 2: Mix the admixture and water evenly, add them to the mixture 1, and continue stirring for 120 seconds to obtain the mixture 2; Step 3: Add the CO2 loading substance to the mixture 2, heat it to 45°C and continue stirring for 20-30 seconds, then let it stand for 60 seconds to obtain the mixture 3; Step 4: pouring the mixture 3 into a mold and allowing it to dry naturally to obtain a high-performance concrete product.

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