Ultra-high performance concrete, compressed air energy storage cavern lining and preparation method of compressed air energy storage cavern lining

Abstract

The invention discloses ultra-high performance concrete, a compressed air energy storage cavern lining and a preparation method of the compressed air energy storage cavern lining, and belongs to the technical field of underground engineering building materials. The ultra-high performance concrete is prepared from the following raw materials: 500 to 520 parts of cement, 100 to 110 parts of fly ash, 120 to 130 parts of silica fume, 200 to 220 parts of mullite powder, 450 to 500 parts of corundum coarse aggregate, 750 to 800 parts of fine aggregate and 30 to 50 parts of basalt fiber. In the preparation method, carbon dioxide curing is carried out, the volume concentration is 20-30%, and the gas pressure difference of the curing environment is 0.4-0.5 MPa. A high-temperature-resistant mineral system is constructed according to the formula, the overall strength, compactness and high-temperature stability are improved through grading design, and the toughness and crack resistance are improved through basalt material fibers; the carbon dioxide curing is cooperated with the dual regulation and control effects of a high-temperature-resistant material system and an optimized aggregate structure, so that excellent mechanical properties and air tightness under high-pressure and high-temperature conditions are ensured.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of underground engineering building materials, and particularly relates to an ultra-high performance concrete, a compressed air energy storage cavern lining and a preparation method thereof. BACKGROUND

[0002] The information disclosed in this Background section is only for the purpose of increasing an understanding of the general background of the application and does not necessarily constitute an admission by the patent applicant or the assignee that this information constitutes prior art.

[0003] Large-scale energy storage technology has gradually become an important means to ensure the safe and stable operation of the power system. Among them, compressed air energy storage (CAES) technology is a green and efficient large-capacity energy storage method. The principle of compressed air energy storage technology is to store compressed air in an underground cavern during the low valley period of power load, and release the compressed air to drive power generation during the peak period of power load, so as to realize time shift and balance of energy. The underground cavern, as the core infrastructure of the compressed air energy storage system, its structural safety and air tightness directly affect the operation efficiency and reliability of the whole system. The underground compressed air energy storage cavern needs to be located in a hard rock stratum with stable geology and high integrity, so as to realize basic gas containment through the high strength and low permeability of the natural surrounding rock. However, the natural rock inevitably has structural defects such as joints and fissures, which are extremely easy to become air leakage channels under high pressure, seriously affecting the gas storage efficiency, and even causing safety problems. Therefore, in order to improve the air tightness and structural stability of the gas storage cavern, a composite lining technology is usually used in engineering to close and reinforce the cavern by artificially constructing an inner lining structure.

[0004] The currently widely used composite lining structure mostly uses steel lining plus ordinary concrete, flexible polymer concrete or coating materials to enhance the sealing performance. Although these methods improve the impermeability and air tightness of the lining structure to some extent, they also have many shortcomings. Steel has a high cost and the steel lining structure has a complex construction process, high requirements for construction environment and technology, and a long construction period, which increases the engineering risk. Ordinary concrete has low strength and poor toughness, and is prone to cracking in a long-period and high-frequency pressure fluctuation environment, resulting in a decrease in air tightness. Steel fibers and plastic fibers can improve the crack resistance and toughness of concrete, but steel fibers are prone to corrosion failure in humid and high-temperature environments, and plastic fibers have low melting point and poor thermal stability, which makes it difficult to maintain stable performance in the high-temperature and high-pressure operating environment of the gas storage cavern, and cannot meet the requirements of long-term and safe operation of the energy storage project. The single-angle improvement of the reinforcing fibers cannot meet the working condition requirements of the long-term service of the gas storage cavern. Therefore, developing a new type of concrete material with excellent performance and suitable for complex underground energy storage environment has become a key technical problem that needs to be broken through in the current CAES infrastructure field. SUMMARY

[0005] In order to solve the problems of the prior art, the present application aims to provide an ultra-high performance concrete, a compressed air energy storage cavern lining and a preparation method thereof, which significantly improves the strength, toughness and compactness of the material by introducing coarse aggregate and optimizing the aggregate gradation, and preferably uses high-temperature-resistant coarse aggregate, fibers and mineral admixtures to improve the stability and crack resistance of the concrete under high-temperature cyclic loading conditions, and the preparation process is simple and efficient, the material utilization rate is high, and the whole has excellent structural performance, durability and economic adaptability.

[0006] In order to achieve the above-mentioned purpose, the technical scheme of the present application is as follows: In a first aspect, an ultra-high performance concrete is prepared from the following raw materials by mass: cement 500-520 parts, fly ash 100-110 parts, silica fume 120-130 parts, mullite powder 200-220 parts, corundum coarse aggregate 450-500 parts, fine aggregate 750-800 parts, basalt fiber 30-50 parts, water reducing agent 4-8 parts, and water 100-200 parts.

[0007] In a second aspect, a preparation method of a compressed air energy storage cavern lining based on the above-mentioned ultra-high performance concrete comprises the following steps: S1, mixing and stirring cement, fly ash, silica fume, mullite powder, corundum coarse aggregate and fine aggregate, then adding water reducing agent, water and steel fiber and stirring uniformly, and pouring into a compressed air energy storage cavern lining structure; S2, after pouring for 1-2 days, remove the mold, and perform carbon dioxide curing for 1-2 days, during the curing process, the volume concentration of carbon dioxide gas is 20-30%, and the gas pressure difference of the curing environment is 0.4-0.5 MPa; S3, curing under standard conditions for more than 28 days to obtain a compressed air energy storage cavern lining.

[0008] In a third aspect, the compressed air energy storage cavern lining prepared by the above-mentioned preparation method.

[0009] The present application has the following advantages: 1. The application adds coarse aggregate to ultra-high performance concrete, and selects corundum as the coarse aggregate, and combines mullite powder, fly ash and silica ash to build a high-temperature-resistant mineral system, wherein the main component of corundum is alpha-Al2O3, which has high melting point and high strength, does not deform and soften at high temperature, and can significantly improve the thermal resistance of the concrete framework; mullite powder has stable structure and small thermal expansion coefficient, and has excellent heat resistance and high-temperature creep resistance, fly ash and silica ash can promote UHPC to form a dense gel structure, inhibit the generation of microcracks, reduce porosity, and avoid high-temperature cracking. Further, by matching particles of different particle sizes in a suitable proportion, small particles can fill the gaps between large particles to achieve close packing, and the material has a "coarse-medium-fine-micro" multi-level structure, which improves the density, strength and stability of the material at high temperature, that is, the overall strength, density and high-temperature stability of the ultra-high performance concrete are improved by reasonable particle grading design, and excellent mechanical properties and air tightness are ensured under high pressure and high temperature. Basalt fiber is selected, which has high tensile strength and good heat resistance, can effectively inhibit the expansion of microcracks in a high-temperature environment, improve the toughness and crack resistance of concrete under cyclic loading, and is suitable for long-term complex service environment. The problems of poor sealing, low strength and insufficient durability of the existing lining material in a high-temperature and high-pressure cyclic environment are solved.

[0010] 2. In the preparation process of the pressure gas energy storage cavern lining, carbon dioxide is used for curing for 1-2 days after pouring, and then standard curing is carried out for 28 days, which can improve the early strength and density, and is beneficial to the continuous hydration reaction in the later period, and improves the overall durability. The dual regulation effect of the high-temperature-resistant material system and the optimized aggregate structure is suitable for the construction of large-volume lining in underground high-pressure complex environment, reduces the complexity of construction process, and improves the efficiency of engineering implementation.

[0011] 3. The application uses high-performance mineral admixtures to replace part of the cement, which helps to reduce carbon emissions and achieve the development goal of green and low-carbon building materials. DETAILED DESCRIPTION

[0012] The drawings accompanying the specification of the application form part of the disclosure and serve to further provide a further understanding of the application, the illustrative embodiments thereof and the description thereof serve to explain the application without constituting an improper limitation thereof.

[0013] Figure 1 It is a performance synergistic improvement technology idea diagram of the ultra-high performance concrete for pressure gas energy storage cavern lining in the specific embodiment of the application. DETAILED DESCRIPTION

[0014] It should be noted that the following detailed description is exemplary in nature and is intended to provide further description of the application. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs.

[0015] It is also to be understood that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of example embodiments in accordance with the present application. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms "comprises" and / or "comprising," when used in this specification, specify the presence of stated features, steps, operations, elements, components, and / or groups thereof, but do not preclude the presence or addition of one or more other features, steps, operations, elements, components, and / or groups thereof.

[0016] In an exemplary embodiment of the present application, an ultra-high performance concrete is provided, which is prepared from the following raw materials by mass: cement 500-520 parts, fly ash 100-110 parts, silica fume 120-130 parts, mullite powder 200-220 parts, corundum coarse aggregate 450-500 parts, fine aggregate 750-800 parts, basalt fiber 30-50 parts, water reducing agent 4-8 parts, and water 100-200 parts.

[0017] In the above components, high-temperature-resistant coarse aggregate is introduced to optimize the aggregate gradation and improve the structural strength and compactness, and the mullite powder (3Al2O3·2SiO2), fly ash, and silica fume can form a high-temperature-resistant mineral system; the main component of corundum is α-Al2O3 3， It has a high melting point, high strength, and does not deform or soften at high temperatures, and as a concrete skeleton, it can significantly improve the thermal performance of the material; mullite powder has a stable structure and a small thermal expansion coefficient, and has excellent heat resistance and high-temperature creep resistance; fly ash and silica fume can promote the formation of a dense cementitious structure in UHPC, inhibit the generation of microcracks, reduce porosity, and avoid high-temperature cracking; basalt material fiber has high tensile strength and good heat resistance, and can effectively inhibit the expansion of microcracks in a high-temperature environment, and can achieve a synergistic improvement in mechanical stability and sealing durability under high-temperature cyclic loading under simple preparation process.

[0018] Optionally, the cement is ordinary Portland cement of grade 52.5 or 52.5R, which has good compatibility with polycarboxylate-based water reducing agents.

[0019] Optionally, the fly ash is Grade I fly ash with a loss on ignition of less than 3.0% and a specific surface area of more than 1100 cm 2 / g, which is used to provide a pozzolanic effect, improve material density, improve flowability, and improve durability, and the inert substances can delay phase transition at high temperatures.

[0020] Optionally, the silica ash / volcanic ash has an activity index greater than 95%, wherein the mass percentage of silica is not less than 97%, and the specific surface area is greater than 21.0 m². 2 / g, used to fill micropores in materials, participate in hydration reactions to improve material density, enhance the performance of the interfacial transition zone, and reduce the risk of concrete cracking at high temperatures.

[0021] Optionally, the mullite powder has a particle size of less than 100µm and is a white powder obtained by calcining natural kaolin at a constant temperature between 1450℃ and 1600℃ for 2 to 4 hours, cooling, crushing, and grinding. It has a high melting point, low expansion coefficient, and excellent thermal shock resistance. As an inert mineral bone meal in concrete, it improves the overall high-temperature stability of the material.

[0022] Optionally, the corundum coarse aggregate has a particle size of 5–10 mm and a bulk density of 1.75–1.90 g / cm³. 3 .

[0023] Optionally, the fine aggregate is quartz sand of 180-240 mesh.

[0024] Optionally, the basalt fiber has a length of 10-15 mm, a width of 0.2-0.4 mm, and a tensile strength of not less than 2200 MPa, which is used to improve the crack resistance under high temperature environment and effectively improve impermeability and air tightness.

[0025] Optionally, the water-reducing agent is a polycarboxylate-based high-performance water-reducing agent.

[0026] A typical embodiment of the present invention provides a method for preparing compressed air storage cavern lining based on the above-mentioned ultra-high performance concrete, comprising the following steps: S1. Mix cement, fly ash, silica fume, mullite powder, corundum coarse aggregate and fine aggregate to obtain a mixed dry mix. Then add water-reducing agent, water and steel fiber and mix evenly. Pour into a compressed air storage cavern lining structure. S2. After pouring for 1-2 days, remove the formwork and carry out carbon dioxide curing for 1-2 days. During the curing process, the volume concentration of carbon dioxide gas is 20-30%, and the gas pressure difference of the curing environment is 0.4-0.5 MPa. S3. Under standard conditions, the compressed gas storage cavern lining is obtained after curing for more than 28 days.

[0027] In the above process, ultra-high performance concrete slurry is first prepared and poured into a lining structure. Then, carbon dioxide curing and standard curing are carried out respectively. This can give full play to the advantages of the high-temperature resistant mineral system and achieve a synergistic improvement in mechanical stability and sealing durability under high-temperature cyclic loads.

[0028] Optionally, in S1, after mixing all the water-reducing agent and all the water to obtain a mixture, 60-70% of the mixture is first added to the dry mix and stirred to obtain ultra-high performance concrete slurry. Then, the remaining 30-40% of the mixture and basalt fiber are dispersed and added to the ultra-high performance concrete slurry and stirred evenly.

[0029] Optionally, the mixing method for obtaining the dry mixture is low-speed mixing for 1 to 2 minutes; the mixing method for obtaining the ultra-high performance concrete slurry is high-speed mixing for 3 to 5 minutes, followed by high-speed mixing for 2 to 3 minutes after adding steel fibers.

[0030] Thirdly, the compressed gas energy storage cavern lining prepared by the above-mentioned preparation method.

[0031] Optionally, the lining thickness is 200-250mm, suitable for compressed air energy storage caverns with pressure parameters of 4-8MPa, and the temperature of the stored air after compression is 150℃. The lining structure of the compressed air energy storage cavern does not require steel lining, which can significantly reduce costs and simplify construction.

[0032] The present invention will be further described below with reference to the embodiments.

[0033] Example 1 An ultra-high performance concrete for lining compressed air storage caverns is made from the following raw materials in parts by weight: 510 parts cement, 105 parts fly ash, 125 parts silica fume, 210 parts mullite powder, 475 parts corundum coarse aggregate, 775 parts fine aggregate, 40 parts basalt fiber, 6 parts water-reducing agent, and 150 parts water.

[0034] The cement is grade 52.5 ordinary Portland cement, which has good compatibility with polycarboxylate superplasticizer.

[0035] The fly ash is Class I fly ash, with a loss on ignition of less than 3.0% and a specific surface area greater than 1100 cm². 2 / g.

[0036] The silica ash / volcanic ash has an activity index greater than 95%, wherein the mass percentage of silica is not less than 97%, and the specific surface area is greater than 21.0 m². 2 / g, density is 2.20g / cm³ 3 .

[0037] The mullite powder has a particle size of less than 100µm and is a white powder obtained by calcining natural kaolin at a constant temperature between 1550℃ and 1600℃ for 3 hours, followed by cooling, crushing, and grinding.

[0038] The corundum coarse aggregate has a particle size of 5–10 mm and a bulk density of 1.90 g / cm³. 3 .

[0039] The fine aggregate is 200-mesh quartz sand with a bulk density of less than 1500 kg / m³. 3 .

[0040] The basalt fiber has a length of 13mm, a tensile strength of 2200MPa, and a width of 0.2mm.

[0041] The water-reducing agent is a polycarboxylate-based high-performance water-reducing agent with a solid content greater than 20%, a pH value of around 7.5, and a water reduction rate of over 30%.

[0042] The preparation method of the compressed air storage cavern lining based on the above-mentioned ultra-high performance concrete includes the following steps: S1. Cement, fly ash, silica fume, mullite powder, corundum coarse aggregate and fine aggregate are mixed and stirred at low speed (45 r / min) for 2 min to obtain a dry mixture. All water-reducing agent and all water are mixed to obtain a liquid mixture. 70% of the liquid mixture is added to the dry mixture and stirred at high speed (150 r / min) for 5 min to obtain an ultra-high performance concrete slurry. Then, the remaining 30% of the liquid mixture and basalt fiber are dispersed into the ultra-high performance concrete slurry and stirred at high speed (150 r / min) for 3 min. The mixture is then poured into an ultra-high performance concrete lining for compressed air storage caverns. S2. After pouring for 1 day, the formwork is removed and carbon dioxide curing is carried out for 2 days. During the curing process, the volume concentration of carbon dioxide gas is 30%, and the gas pressure difference of the curing environment is 0.5 MPa (i.e., 0.5 MPa higher than atmospheric pressure). S3, cure under standard conditions for more than 28 days.

[0043] Example 2 An ultra-high performance concrete for lining compressed air energy storage caverns is made from the following raw materials in parts by weight: 500 parts cement, 100 parts fly ash, 120 parts silica fume, 200 parts mullite powder, 450 parts corundum coarse aggregate, 750 parts fine aggregate, 30 parts basalt fiber, 4 parts water-reducing agent, and 100 parts water.

[0044] The requirements for each raw material and the preparation method are the same as in Example 1.

[0045] Example 3 An ultra-high performance concrete for lining compressed air storage caverns is made from the following raw materials in parts by weight: 520 parts cement, 110 parts fly ash, 130 parts silica fume, 220 parts mullite powder, 500 parts corundum coarse aggregate, 800 parts fine aggregate, 50 parts basalt fiber, 8 parts water-reducing agent, and 200 parts water.

[0046] The requirements for each raw material and the preparation method are the same as in Example 1.

[0047] Comparative Example 1 An ultra-high performance concrete for lining compressed air energy storage caverns is made from the following raw materials in parts by weight: 720 parts cement, 105 parts fly ash, 125 parts silica fume, 475 parts corundum coarse aggregate, 775 parts fine aggregate, 40 parts basalt fiber, 6 parts water-reducing agent, and 150 parts water.

[0048] The difference from Example 1 is that the mullite is replaced with the same mass of cement, so that it does not have the high-temperature resistant mineral system of Example 1.

[0049] The other raw materials and preparation methods are the same as in Example 1.

[0050] Comparative Example 2 An ultra-high performance concrete for lining compressed air storage caverns is made from the following raw materials in parts by weight: 620 parts cement, 125 parts fly ash, 155 parts silica fume, 210 parts mullite powder, 875 parts fine aggregate, 40 parts basalt fiber, 6 parts water-reducing agent, and 150 parts water.

[0051] The difference from Example 1 is that no coarse aggregate is added, and the mass fractions of other components in the dry mix, except for mullite powder, are added accordingly.

[0052] The other raw materials and preparation methods are the same as in Example 1.

[0053] Comparative Example 3 An ultra-high performance concrete for lining compressed air energy storage caverns is made from the following raw materials in parts by weight: 510 parts cement, 105 parts fly ash, 125 parts silica fume, 210 parts mullite powder, 475 parts corundum coarse aggregate, 775 parts fine aggregate, 40 parts steel fiber, 6 parts water-reducing agent, and 150 parts water.

[0054] The steel fibers are 13mm long, 0.2mm wide, and have a tensile strength of 2500MPa.

[0055] The difference from Example 1 is that the basalt fiber in Example 1 is replaced with steel fiber, so that it does not have the fiber that can maintain its performance in a high-temperature environment as in Example 1.

[0056] The other raw materials and preparation methods are the same as in Example 1.

[0057] Comparative Example 4 An ultra-high performance concrete for lining compressed air storage caverns is made from the following raw materials in parts by weight: 800 parts cement, 160 parts fly ash, 132 parts silica fume, 900 parts natural river sand, 40 parts steel fiber, 6 parts water-reducing agent, and 210 parts water.

[0058] The natural river sand is classified as medium sand, with a particle size distribution that meets the requirements of "T / CECS 10107-2020 Technical Requirements for Ultra-High Performance Concrete", and a bulk density of 1400 kg / m³. 3 .

[0059] The difference from Comparative Example 3 is that mullite powder, corundum coarse aggregate and fine aggregate are not added. Instead, natural river sand is added as a component of the dry mix, and the mass fraction of other components in the dry mix is ​​increased accordingly, so that it does not have the gradation characteristics of Example 1.

[0060] The remaining raw materials and preparation methods are the same as in Example 1. Comparative Example 5 An ultra-high performance concrete for lining compressed air energy storage caverns is made from the following raw materials in parts by weight: 510 parts cement, 105 parts fly ash, 125 parts silica fume, 210 parts mullite powder, 475 parts corundum coarse aggregate, 775 parts fine aggregate, 40 parts steel fiber, 6 parts water-reducing agent, and 150 parts water.

[0061] In the preparation method, the carbon dioxide curing step in S2 is not used. Instead, the mold is removed 1 day after casting, and then the standard conditions are directly used for curing until 28 days.

[0062] The difference from Example 1 is that carbon dioxide curing is not used.

[0063] The raw materials and other preparation methods are the same as in Example 1.

[0064] The performance of each embodiment and preparation example was then tested, including expansion, room temperature testing, and 80°C testing. The room temperature test and 80°C test included compressive strength, total crack area per unit area, and measurement of ultrasonic wave propagation rate, respectively. The performance test results are shown in Table 1.

[0065] The method for obtaining the total crack area per unit area includes: obtaining the length and width of all cracks on the measurement surface after 28 days of curing, and then dividing them by the area of ​​the measurement surface to obtain the total crack area per unit area, which is used to characterize the degree of cracking.

[0066] The propagation rate of ultrasonic waves is used to characterize the density of a material.

[0067] Table 1

[0068] It can be seen that the ultra-high performance concrete in Example 1 exhibits significant performance improvements, reflected in higher compressive strength, lower crack initiation rate, and higher density. Specifically, Example 1 demonstrates excellent comprehensive performance under both ambient and 80°C high-temperature conditions. In terms of mechanical properties, Example 1 shows higher compressive strength at 3 days and 28 days at ambient temperature than most comparative examples, and retains a strength of 125.3 MPa at 28 days under high-temperature conditions. The compressive strength retention rate is significantly better than other comparative groups, indicating that the material possesses excellent structural load-bearing capacity and high-temperature stability. Regarding key indicators such as crack resistance and density, the total crack area per unit area of ​​Example 1 is only 130.8 mm² at ambient temperature. 2 / m 2 At high temperatures, it is 134.8 mm. 2 / m 2 The density was significantly lower than that of comparative examples 1 to 5, reflecting extremely high density and structural homogeneity, which ensured the long-term airtightness of the lining in a high-pressure fluctuating environment.

[0069] The ultra-high performance concrete lining material and its preparation method proposed in this invention are based on the stringent requirements of complex underground gas storage environments for material strength, sealing, and durability, and fully integrate material system innovation with curing process optimization. For example... Figure 1 As shown, in terms of the material system, by introducing high-temperature stable components such as corundum coarse aggregate and mullite powder, a mineral framework structure with high density and strong thermal stability is constructed, which significantly enhances the structural stability and airtightness of concrete under high-temperature and high-pressure cyclic conditions. The addition of basalt fiber endows the concrete with excellent toughness and crack resistance, effectively inhibiting the development of microcracks and improving the service reliability of the material under high-frequency loads. In terms of curing, this invention adopts a combination of "early carbonization + later standard curing," which not only improves early strength and structural density but also promotes the continuous development of later hydration reactions, thereby enhancing the overall durability and airtightness retention of concrete. Comparative performance test data from the examples and multiple comparative groups show that the UHPC prepared by this invention exhibits higher compressive strength, smaller crack area, and higher ultrasonic propagation rate under both room temperature and 80℃ high-temperature conditions, comprehensively outperforming existing mix proportions, verifying its applicability and advantages in high-temperature and high-pressure gas energy storage caverns. In summary, this invention not only solves the problems of poor sealing performance and low temperature resistance of existing materials, but also achieves multiple breakthroughs in structural performance, maintenance technology, and the application of green and low-carbon materials, providing key material support and a practical technical path for the construction of efficient, safe, and environmentally friendly compressed gas energy storage infrastructure.

[0070] Example 4 A pneumatic energy storage cavern has an internal structure lined with ultra-high performance concrete prepared using the formula and preparation method described in Example 1. Specifically, after pouring concrete on the inner surface of the pneumatic energy storage cavern, carbon dioxide gas is injected into the pneumatic energy storage cavern, and curing is carried out according to the method described in Example 1.

[0071] The prepared gas-pressure energy storage cavern lining has mechanical stability and sealing durability under high-temperature cyclic load. The service conditions include a lining thickness of 250 mm, a compressed air energy storage cavern parameter of 8 MPa, and an air temperature of up to 150 °C after compression.

[0072] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A type of ultra-high performance concrete, characterized in that, It is made from the following raw materials in parts by weight: 500-520 parts cement, 100-110 parts fly ash, 120-130 parts silica fume, 200-220 parts mullite powder, 450-500 parts corundum coarse aggregate, 750-800 parts fine aggregate, 30-50 parts basalt fiber, 4-8 parts water-reducing agent, and 100-200 parts water.

2. The ultra-high performance concrete as described in claim 1, characterized in that, The cement is ordinary Portland cement of grade 52.5 or 52.5R, which has good compatibility with polycarboxylate superplasticizer; Alternatively, the fly ash is Class I fly ash with a loss on ignition of less than 3.0% and a specific surface area greater than 1100 cm². 2 / g.

3. The ultra-high performance concrete as described in claim 1, characterized in that, The silica ash / volcanic ash has an activity index greater than 95%, wherein the mass percentage of silica is not less than 97%, and the specific surface area is greater than 21.0 m². 2 / g; Alternatively, the mullite powder may have a particle size of less than 100µm.

4. The ultra-high performance concrete as described in claim 1, characterized in that, The corundum coarse aggregate has a particle size of 5–10 mm and a bulk density of 1.75–1.90 g / cm³. 3 ; Alternatively, the fine aggregate may be quartz sand of 180-240 mesh.

5. The ultra-high performance concrete as described in claim 1, characterized in that, The basalt fibers have a length of 10–15 mm, a width of 0.2–0.4 mm, and a tensile strength of not less than 2200 MPa. Alternatively, the water-reducing agent may be a polycarboxylate-based high-performance water-reducing agent.

6. A method for preparing compressed air storage cavern lining based on ultra-high performance concrete as described in any one of claims 1-5, characterized in that, Includes the following steps: S1. Mix cement, fly ash, silica fume, mullite powder, corundum coarse aggregate and fine aggregate to obtain a mixed dry mix. Then add water-reducing agent, water and steel fiber and mix evenly. Pour into a compressed air storage cavern lining structure. S2. After pouring for 1-2 days, remove the formwork and carry out carbon dioxide curing for 1-2 days. During the curing process, the volume concentration of carbon dioxide gas is 20-30%, and the gas pressure difference of the curing environment is 0.4-0.5 MPa. S3. Under standard conditions, the compressed gas storage cavern lining is obtained after curing for more than 28 days.

7. The method for preparing the lining of the compressed gas energy storage cavern as described in claim 6, characterized in that, In S1, all water-reducing agent and all water are mixed to obtain a mixture. First, 60-70% of the mixture is added to the dry mix and stirred to obtain ultra-high performance concrete slurry. Then, the remaining 30-40% of the mixture and basalt fiber are dispersed and added to the ultra-high performance concrete slurry and stirred evenly.

8. The method for preparing the lining of the compressed gas energy storage cavern as described in claim 7, characterized in that, The mixing method for obtaining the dry mixture is low-speed mixing for 1-2 minutes; the mixing method for obtaining the ultra-high performance concrete slurry is high-speed mixing for 3-5 minutes, followed by high-speed mixing for 2-3 minutes after adding steel fibers.

9. A compressed gas storage cavern lining prepared by the preparation method according to any one of claims 7-8.

10. The compressed air storage cavern lining as described in claim 9, characterized in that, The lining thickness is 200-250mm.

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