Self-sensing sprayed high-performance glass aggregate concrete and preparation method thereof

Abstract

The present invention discloses a self-sensing sprayed high-performance glass aggregate concrete and a preparation method thereof, and belongs to the field of concrete technology. The raw materials of the self-sensing sprayed high-performance glass aggregate concrete are calculated by mass and include: 749-763 parts of cement, 154-170 parts of fly ash, 154-170 parts of silica fume, 115-125 parts of metakaolin, 840 parts of fine aggregate, 225-255 parts of water, 14.6-19.0 parts of water reducer and 8.75-15.75 parts of carbon fiber; the fine aggregate is composed of glass sand and machine-made sand. The high-performance sprayed concrete prepared by the present invention uses glass sand to replace part of the machine-made sand, which solves the problems of low strength and insufficient durability of traditional sprayed concrete. At the same time, it also has the ability to perform real-time health monitoring of the concrete structure after shaping, so as to ensure the reliability and safety of the structure, extend the service life and reduce maintenance costs.

Description

Technical Field

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

[0002] With the widespread use of concrete, the demand for sand has gradually increased. Both standard and high-performance concrete use quartz sand, river sand, and manufactured sand. In concrete, sand plays multiple roles, including lubrication, structural support, and filler. However, the large-scale use of sand also has some negative effects. During use, fine particles of quartz sand become suspended in the air, increasing the risk of silicosis and damaging the respiratory system. Furthermore, river sand resources are limited, and the mining process can severely damage the ecological balance of rivers and endanger the habitats of aquatic life. Therefore, some regions have banned river sand mining. Manufactured sand is produced from mountain rocks through mechanical crushing, making it easier to obtain raw materials than river sand. However, due to the strong force of mechanical crushing, the particles of manufactured sand are often angular, with a rough surface and poor flowability. Furthermore, the mining process directly damages the mountain structure and disrupts the ecological balance. Therefore, in order to achieve sustainable development of ecological balance and promote harmonious coexistence of humans and nature, people urgently need an economical, efficient, resource-saving, green and low-carbon high-performance concrete preparation method to more comprehensively utilize resources, improve environmental quality and enhance the stability of the ecosystem.

[0003] Guided by the need to meet the performance requirements of concrete for different purposes, concrete needs to be guaranteed in terms of durability, workability, applicability, strength, volume stability, etc. To achieve this goal, improvements need to be made in many aspects during the preparation process.

[0004] Shotcrete is a type of concrete that is sprayed onto the sprayed surface using a pressure spray gun and compacted instantly. With the development of society, traditional shotcrete can no longer meet the needs of tunnel lining. The engineering use environment of shotcrete is diverse, involving complex geological, hydrological and meteorological conditions. To ensure the safety and reliability of tunnel structures, real-time monitoring of the concrete status is also crucial. In addition, over time, concrete structures may deform and damage. To ensure that the tunnel structure remains in good working condition throughout its life cycle, it is crucial to regularly inspect the structure for deformation and damage. Therefore, how to prepare a shotcrete high-performance concrete that has excellent adhesion, durability and strength properties while also meeting the needs of environmental protection and real-time health monitoring is a technical problem that those skilled in the art urgently need to solve. Summary of the Invention

[0005] The present invention aims to provide a self-sensing, high-performance glass aggregate sprayed concrete and its preparation method. This high-performance sprayed concrete uses glass sand in place of some machine-made sand, addressing the low strength and durability issues of traditional sprayed concrete. It also provides real-time health monitoring of the finalized concrete structure, ensuring structural reliability and safety, extending its service life, and reducing maintenance costs.

[0006] To achieve the above object, the present invention provides the following technical solutions:

[0007] One of the technical solutions of the present invention is to provide a self-sensing sprayed high-performance glass aggregate concrete, in which glass sand is used to partially replace machine-made sand as the fine aggregate of the self-sensing sprayed high-performance glass aggregate concrete. Calculated by mass fraction, the amount of glass sand is 25-75% of the total mass of the fine aggregate.

[0008] Preferably, the raw materials include, by mass, 749-763 parts of cement, 154-170 parts of fly ash, 154-170 parts of silica fume, 115-125 parts of metakaolin, 840 parts of fine aggregate, 225-255 parts of water, 14.6-19.0 parts of water reducer, and 8.75-15.75 parts of carbon fiber;

[0009] The fine aggregate consists of glass sand and machine-made sand.

[0010] More preferably, the water reducer is one or more of lignin sulfonate water reducer, naphthalene water reducer, melamine water reducer, aminosulfonate water reducer, aliphatic water reducer and polycarboxylic acid water reducer.

[0011] Preferably, the particle size of the machine-made sand is 0-4.75 mm, and is not 0.

[0012] Preferably, the average particle size of the glass sand is 0.15 mm.

[0013] More preferably, the raw materials, calculated by mass, are: 756 parts of cement, 162 parts of fly ash, 162 parts of silica fume, 120 parts of metakaolin, 210 parts of machine-made sand, 630 parts of glass sand, 240 parts of water, 16.8 parts of water reducer and 15.75 parts of carbon fiber.

[0014] The second technical solution of the present invention is to provide a method for preparing the self-sensing sprayed high-performance glass aggregate concrete, comprising the following steps:

[0015] The self-sensing sprayed high-performance glass aggregate concrete is obtained by mixing the raw materials.

[0016] The third technical solution of the present invention is to provide an application of the above-mentioned self-sensing sprayed high-performance glass aggregate concrete in tunnel lining.

[0017] The beneficial technical effects of the present invention are as follows:

[0018] The present invention uses glass sand to replace part of the machine-made sand to prepare high-performance sprayed concrete. Glass sand is a good substitute for machine-made sand and can react with Ca(OH)2 produced during concrete hydration to further promote the secondary hydration of cement, thereby improving the strength of cement. Moreover, the glass sand used is in the form of microbeads from a microscopic point of view, and its surface is smooth, round and uniform. The present invention further limits the particle size of glass sand to partially replace machine-made sand, thereby compensating for the performance loss caused by the rough surface of machine-made sand, reducing the weak areas that are easily formed between the interface of aggregate and slurry, improving the fluidity, impermeability and filling properties of cement slurry, reducing the porosity, and thus improving the density and strength of sprayed concrete.

[0019] This invention uses carbon fiber as a component in the preparation of high-performance shotcrete. The three-dimensional, random distribution of carbon fibers effectively limits the expansion of microcracks within the concrete and the formation of macrocracks. Furthermore, the introduction of carbon fiber, a material with excellent electrical conductivity, effectively enhances the electrical conductivity of concrete, forming a conductive network that allows current to flow along the interface between the carbon fiber and the cement paste, thereby facilitating structural health monitoring.

[0020] This invention uses a cementitious material mixed with water to form a soft slurry, which tightly wraps and packs the manufactured sand and glass sand. This not only provides sufficient compressive strength to meet engineering requirements, but also enhances the cohesiveness of the shotcrete and increases the thickness of a single coat of high-performance concrete. By replacing manufactured sand with glass sand, this invention conserves resources, reduces energy consumption, and minimizes environmental damage. This approach not only reduces dependence on natural resources but also helps lower carbon emissions, creating environmentally friendly conditions for sustainable development.

[0021] The high-performance shotcrete produced by this method addresses the low strength and durability issues of conventional shotcrete. It also provides real-time health monitoring of finalized concrete structures, ensuring timely detection and prevention of potential damage and disasters during their use, ensuring structural reliability and safety, extending service life, and reducing maintenance costs. This method can be widely applied in tunnel linings, while also mitigating the environmental impact of construction.

[0022] By maximizing the use of various raw materials, reducing the amount of water and cementitious materials added, and fully utilizing the functions of admixtures and additives, the present invention improves resource utilization efficiency during the preparation process, thereby making the preparation process more economical, rational, and efficient. This method has achieved positive results in terms of resource utilization efficiency, environmental protection, and economic rationality, providing strong support for sustainable development. DETAILED DESCRIPTION

[0023] Various exemplary embodiments of the present invention are now described in detail. This detailed description should not be considered as a limitation of the present invention, but should be understood as a more detailed description of certain aspects, features, and embodiments of the present invention. It should be understood that the terms used in the present invention are only for describing specific embodiments and are not intended to limit the present invention.

[0024] In addition, for numerical ranges in the present invention, it is understood that each intervening value between the upper and lower limits of the range is also specifically disclosed. Each smaller range between any stated value or stated range, and any other stated value or intervening value in the stated range, is also included in the present invention. The upper and lower limits of these smaller ranges may independently be included or excluded in the range.

[0025] 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 the invention pertains. Although preferred methods and materials have been described herein, any methods and materials similar or equivalent to those described herein can also be used in the practice or testing of the present invention.

[0026] The terms “include,” “including,” “have,” “contain,” etc. used in the present invention are open-ended terms, meaning including but not limited to.

[0027] On one hand, the present invention provides a self-sensing sprayed high-performance glass aggregate concrete, in which glass sand is partially used instead of machine-made sand as fine aggregate of the self-sensing sprayed high-performance glass aggregate concrete. Calculated by mass fraction, the amount of the glass sand is 25-75% of the total mass of the fine aggregate.

[0028] The raw materials, calculated by mass, include: 749-763 parts of cement, 154-170 parts of fly ash, 154-170 parts of silica fume, 115-125 parts of metakaolin, 840 parts of fine aggregate, 225-255 parts of water, 14.6-19.0 parts of water reducer, and 8.75-15.75 parts of carbon fiber;

[0029] The fine aggregate consists of glass sand and machine-made sand.

[0030] The water reducer is one or more of lignin sulfonate water reducer, naphthalene water reducer, melamine water reducer, aminosulfonate water reducer, aliphatic water reducer and polycarboxylic acid water reducer.

[0031] In a preferred embodiment of the present invention, the water reducer is an HLX standard polycarboxylic acid high performance water reducer aqueous solution.

[0032] HLX standard polycarboxylic acid high-performance water-reducing agent aqueous solution can greatly reduce water demand and water-binder ratio without changing the working performance of sprayed high-performance concrete, thereby effectively improving the mechanical properties and durability of sprayed high-performance concrete and improving the bearing capacity of tunnel structures.

[0033] In a preferred embodiment of the present invention, the average particle size of the glass sand is 0.15 mm.

[0034] The glass sand is prepared by grinding the glass material into particles with an average particle size of 0.15 mm, then heating and melting the particles at 730° C. to form microbeads under the action of surface tension.

[0035] Although there are existing technical solutions for partially replacing machine-made sand with recycled glass sand, since recycled glass sand has a higher water absorption rate than natural sand, conventionally increasing the amount of glass sand added will significantly affect the water-cement ratio, thereby reducing the workability and strength of concrete and affecting the mechanical properties of the product. To address the above technical problems, the present invention uses glass sand with a particle size of 0.15 mm. Its regular and smooth microbead shape not only reduces water absorption (it can reduce the water absorption rate to lower than that of machine-made sand), but also fills the pores in the concrete, reducing the void content of the concrete, thereby improving the mechanical strength of the shotcrete. This phenomenon allows the gaps within the shotcrete caused by the particle size of the machine-made sand to be filled, improving the gradation of the concrete. Therefore, when the glass sand content is 0-75%, its compressive strength shows an upward trend. However, when glass sand is further used to replace machine-made sand, it will reduce the gap gradation and bulk density of the aggregate, resulting in an increase in the void content of the concrete, which will reduce the density and bond strength of the concrete, thereby reducing the strength of the concrete. Moreover, the alkali content of recycled glass sand is higher than that of natural sand. During the use of concrete structures, recycled glass sand may react with certain active aggregates to produce alkali-aggregate reaction, resulting in cracking and performance degradation of concrete, which will permanently affect the durability of concrete while reducing its strength. The mix ratio of this patent contains rich high-activity admixtures, whose hydration products can undergo sufficient secondary hydration reaction with fine-grained glass sand to form more hydrated calcium silicate, which greatly reduces the concentration of alkaline solution in the pores of concrete. In addition, the glass sand selected this time is 0.15mm micro-beads, which greatly increases the specific surface area. The increase in specific surface area further promotes the reaction, greatly reducing the impact of the later alkali-aggregate reaction on concrete, thereby effectively improving the strength of concrete while improving its durability.

[0036] In a preferred embodiment of the present invention, the particle size of the machine-made sand used is 0 to 4.75 mm. Since there is no coarse aggregate in the mixed slurry, it can be transported more smoothly in the pipeline without causing pipeline blockage, thereby improving the spraying effect of high-performance concrete.

[0037] In a preferred embodiment of the present invention, the raw materials, calculated by mass, are: 756 parts of cement, 162 parts of fly ash, 162 parts of silica fume, 120 parts of metakaolin, 210 parts of machine-made sand, 630 parts of glass sand, 240 parts of water, 16.8 parts of water reducer and 15.75 parts of carbon fiber.

[0038] Another aspect of the present invention provides a method for preparing the self-sensing sprayed high-performance glass aggregate concrete, comprising the following steps:

[0039] The self-sensing sprayed high-performance glass aggregate concrete is obtained by mixing the raw materials.

[0040] In a preferred embodiment of the present invention, the preparation steps are as follows:

[0041] (1) Cement, fly ash, silica fume, metakaolin, machine-made sand and glass sand are mixed evenly, and then carbon fiber is added and mixed again to obtain a shotcrete dry mix;

[0042] (2) Mix the water reducer with water, pour it into the above-mentioned shotcrete dry mix and mix it into a slurry, then spray the slurry onto the sprayed surface and obtain the shotcrete after solidification.

[0043] Whether the distribution of carbon fiber in concrete is uniform determines the mechanical properties and self-sensing properties of shotcrete to a large extent, and excessive addition will lead to fiber agglomeration and difficulty in dispersion, thereby affecting the improvement effect of carbon fiber on the mechanical properties of concrete. In order to make the carbon fiber dispersed as evenly as possible in the concrete matrix, so as to play a better effect, the present invention first puts sand and cementitious materials (cement, fly ash, silica fume and metakaolin) into a mixer and stirs them, and then puts in carbon fiber for stirring; the addition of glass sand promotes the dispersion of carbon fiber to a certain extent. Moreover, the incorporation of carbon fiber will also have a synergistic effect with other cementitious materials. Carbon fiber forms a three-dimensional connection system in concrete, hinders the expansion and penetration of cracks, and increases the bearing capacity and toughness of cracks. Cementitious materials can improve the mechanical properties of concrete through hydration reaction, reduce the porosity of concrete, and thus reduce the generation and development of cracks. The synergistic effect of the two effectively improves the splitting tensile strength and flexural strength of shotcrete.

[0044] Another aspect of the present invention provides an application of the self-sensing sprayed high-performance glass aggregate concrete in tunnel lining.

[0045] The cement used in the following examples and comparative examples of the present invention is P.II52.5 cement with a specific surface area of ​​365 kg / m 2 , loss on ignition ≤3.5%, purchased from Jilin Yatai Cement Co., Ltd.

[0046] The fly ash used in the following examples and comparative examples of the present invention is Class I fly ash with a loss on ignition of ≤5% and a strength activity index of ≥70%, purchased from Hebei Shengyi Mineral Products Trading Co., Ltd.

[0047] The silica fume used in the following examples and comparative examples of the present invention has a SiO2 content of ≥90%, a pH value of 4.0-8.5, and a loss on ignition of ≤2%, and is purchased from Gansu Sanyuan Silicon Materials Co., Ltd.

[0048] The metakaolin used in the following examples and comparative examples of the present invention has a SiO2 content of 51-57%, an Al2O3 content of 40-46%, a 7-day activity index ≥110%, and a 28-day activity index ≥120%, and is purchased from Inner Mongolia Chaopai New Materials Co., Ltd.

[0049] The particle size of the machine-made sand used in the following embodiments and comparative examples of the present invention is 0-4.75 mm and not 0, the fineness modulus is 2.66, the stone powder content is ≤2%, and it is purchased from Qingfeng Mining in Jilin Province.

[0050] The carbon fibers used in the following examples and comparative examples of the present invention have a carbon content of 95.9%, an elastic modulus of 238 GPa, and a length of 6 mm, and were purchased from Shanghai Lishuo Composite Materials Technology Co., Ltd.

[0051] The glass sand used in the following examples and comparative examples of the present invention has an average particle size of 0.15 mm, a SiO2 content of 72.81%, a melting point of 730°C, and a specific gravity of 2.4 to 2.6 g / cm 3 , purchased from Ningbo Hongyang Cleaning Equipment Co., Ltd. The glass sand used was prepared by grinding the glass material to particles with an average particle size of 0.15 mm, then heating and melting it at 730°C to form micro beads under the action of surface tension.

[0052] The polycarboxylic acid water reducer used in the following examples and comparative examples of the present invention is an HLX standard polycarboxylic acid high-performance water reducer aqueous solution with a solid content of 38±1.9%, a pH value of 5.0±1.0, a water reduction rate of ≥25%, and an air content of ≤6.0%, purchased from Shanxi Feike New Material Technology Co., Ltd.

[0053] The slurries in the following embodiments and comparative examples of the present invention were sprayed using a PT850 wet coarse sand sprayer manufactured by Hubei Locomotive Huanfa Machinery Manufacturing Co., Ltd.

[0054] The raw materials used in the following examples and comparative examples of the present invention are all commercially available products.

[0055] Example 1

[0056] The raw materials for shotcrete are as follows:

[0057] 756 parts of cement, 162 parts of fly ash, 162 parts of silica fume, 120 parts of metakaolin, 630 parts of machine-made sand, 210 parts of glass sand, 240 parts of water, 16.8 parts of water reducer and 8.75 parts of carbon fiber.

[0058] The specific preparation steps are as follows:

[0059] (1) Cement, fly ash, silica fume, metakaolin, machine-made sand and glass sand are mixed evenly, and then carbon fiber is added and mixed again to obtain a shotcrete dry mix.

[0060] (2) Mix the water reducer with water, pour it into the above-mentioned shotcrete dry mix and mix it into a slurry, then spray the slurry onto the sprayed surface and obtain the shotcrete after solidification.

[0061] Example 2

[0062] The raw materials of shotcrete are as follows:

[0063] 756 parts of cement, 162 parts of fly ash, 162 parts of silica fume, 120 parts of metakaolin, 420 parts of machine-made sand, 420 parts of glass sand, 240 parts of water, 16.8 parts of water reducer and 8.75 parts of carbon fiber.

[0064] The specific preparation steps are shown in Example 1.

[0065] Example 3

[0066] The raw materials of shotcrete are as follows:

[0067] 756 parts of cement, 162 parts of fly ash, 162 parts of silica fume, 120 parts of metakaolin, 210 parts of machine-made sand, 630 parts of glass sand, 240 parts of water, 16.8 parts of water reducer and 8.75 parts of carbon fiber.

[0068] The specific preparation steps are shown in Example 1.

[0069] Example 4

[0070] The raw materials of shotcrete are as follows:

[0071] 756 parts of cement, 162 parts of fly ash, 162 parts of silica fume, 120 parts of metakaolin, 840 parts of glass sand, 240 parts of water, 16.8 parts of water reducer and 8.75 parts of carbon fiber.

[0072] The specific preparation steps are as follows:

[0073] (1) Cement, fly ash, silica fume, metakaolin and glass sand are mixed evenly, and then carbon fiber is added and mixed again to obtain a shotcrete dry mix.

[0074] (2) Mix the water reducer with water, pour it into the above-mentioned shotcrete dry mix and mix it into a slurry, then spray the slurry onto the sprayed surface and obtain the shotcrete after solidification.

[0075] Example 5

[0076] The only difference from Example 1 is that the mass fraction of carbon fiber is changed from 8.75 parts to 12.25 parts.

[0077] Example 6

[0078] The only difference from Example 2 is that the mass fraction of carbon fiber is changed from 8.75 parts to 12.25 parts.

[0079] Example 7

[0080] The only difference from Example 3 is that the mass fraction of carbon fiber is changed from 8.75 parts to 12.25 parts.

[0081] Example 8

[0082] The only difference from Example 4 is that the mass fraction of carbon fiber is changed from 8.75 parts to 12.25 parts.

[0083] Example 9

[0084] The only difference from Example 1 is that the mass fraction of carbon fiber is changed from 8.75 parts to 15.75 parts.

[0085] Example 10

[0086] The only difference from Example 2 is that the mass fraction of carbon fiber is changed from 8.75 parts to 15.75 parts.

[0087] Example 11

[0088] The only difference from Example 3 is that the mass fraction of carbon fiber is changed from 8.75 parts to 15.75 parts.

[0089] Example 12

[0090] The only difference from Example 4 is that the mass fraction of carbon fiber is changed from 8.75 parts to 15.75 parts.

[0091] Comparative Example 1

[0092] The only difference from Example 1 is that the addition of glass sand is omitted and an equal mass of machine-made sand is added.

[0093] Comparative Example 2

[0094] The only difference from Example 5 is that the addition of glass sand is omitted and an equal mass of machine-made sand is added.

[0095] Comparative Example 3

[0096] The only difference from Example 9 is that the addition of glass sand is omitted and an equal mass of machine-made sand is added.

[0097] Comparative Example 4

[0098] The only difference from Example 4 is that the addition of carbon fibers is omitted.

[0099] Comparative Example 5

[0100] The only difference from Example 8 is that the addition of carbon fiber is omitted and an equal volume of polypropylene fiber purchased from Beijing Zhongfang Fiber Construction Technology Co., Ltd. is added.

[0101] Comparative Example 6

[0102] The only difference from Example 8 is that the addition of carbon fibers is omitted and an equal volume of steel fibers purchased from Wuyi Nengda Metal Products Co., Ltd. is added.

[0103] Comparative Example 7

[0104] The only difference from Example 1 is that the cement is replaced with P.042.5 cement of equal mass purchased from Jilin Yatai Cement Co., Ltd.

[0105] The remaining steps are the same as in Example 1.

[0106] Comparative Example 8

[0107] The only difference from Example 4 is that the addition of glass sand is omitted and quartz sand of equal mass purchased from Foshan Yufeng Powder Material Co., Ltd. is supplemented.

[0108] Effect verification

[0109] (1) Mechanical properties of the shotcrete prepared in Examples 1-12 and Comparative Examples 1-8 were tested. Compressive strength and splitting tensile strength of the shotcrete were tested in accordance with JGJ / T372-2016, GB / T 50080-2011, GB / T 50081-2019, and GB / T 50082-2009. Compressive strength includes compressive strength at 1 day, 7 days, 14 days, 28 days, and 56 days. The test results are shown in Table 1.

[0110] Table 1 Mechanical properties test

[0111]

[0112] As shown in Table 1, the 56-day compressive strength of Examples 1-4 shows that when the ratio of glass sand addition to fine aggregate content (glass sand + machine-made sand) is between 0-75%, the greater the amount of glass sand used, the greater the strength of the concrete specimen; however, if further addition is made, the compressive strength will decrease to a level far lower than that of Example 1; this is mainly because further increasing the proportion of glass sand will have an adverse effect on grading. At the same time, a comparison of the data in Table 1 shows that further increasing the amount of carbon fiber added based on the examples with higher glass sand additions can further improve product performance, indicating that adding more glass sand can improve the uniformity of carbon fiber distribution in concrete.

[0113] In addition, although the inventors also prepared a slurry with a higher carbon fiber addition amount than Examples 10-12, they observed the agglomeration of carbon fibers and considered that once the fibers agglomerated, the jet would be blocked, which would cause great losses. Therefore, for practical considerations, no relevant data was tested.

[0114] (2) The sprayed concrete prepared in Examples 1-12 and Comparative Examples 1-8 was subjected to pressure-sensitive performance testing. Using the two-electrode method, the initial resistance and resistance under loads of 2 MPa, 4 MPa, 6 MPa, 8 MPa, and 10 MPa were measured. The test results are shown in Table 2.

[0115] Table 2 Pressure-sensitive performance test

[0116]

[0117] It is a consensus in the existing technology that using glass aggregate as aggregate will lead to a decrease in the pressure-sensitive performance of the specimen. Therefore, glass aggregate is generally not used when preparing self-sensing concrete.

[0118] However, as shown in Table 2 of the present invention, the concrete produced using the present invention exhibits a good correlation between resistance and load, demonstrating excellent pressure sensitivity and fully meeting the requirements of practical applications. This is primarily due to the design of the raw material types and proportions of the reactive powder concrete, which reduces the proportion of cementitious materials and porosity, thereby minimizing the loss of concrete pressure sensitivity. As the load increases, the resistance tends to decrease. This is because when external force is applied to the composite material, the distance between the conductive fillers changes, resulting in a change in resistance.

[0119] The sprayed concrete prepared by the present invention has high early strength and late strength, is highly practical, saves construction costs, and ensures high project quality. Therefore, the sprayed concrete prepared by the present invention has strong scalability.

[0120] (3) The sprayed concrete prepared in Examples 1-12 was subjected to a durability test.

[0121] The durability of shotcrete directly impacts the safety and service life of engineering structures. As a supporting material for tunnels, water conservancy projects, and mining operations, shotcrete must withstand a variety of environmental factors and loads. Poor durability can lead to reduced strength, increased cracking, structural damage, and even engineering accidents.

[0122] Permeability is a key indicator of shotcrete's durability, directly impacting its strength, stability, safety, and service life. Therefore, the present invention tested the impermeability of shotcrete. The test method was based on GB / T 50082-2009, Standard for Test Methods for Long-Term Properties and Durability of Ordinary Concrete, and was used to measure the permeability of Examples 1-12.

[0123] According to the test results, the water seepage height of the sprayed concrete in Examples 1-12 was 0 mm. After splitting the test specimens, no water was found to have penetrated into the high-performance sprayed concrete. This phenomenon can be attributed to the lower water-to-binder ratio used in the present invention compared to conventional sprayed concrete, which significantly reduces the void content. Furthermore, the filling effect of the fine-grained glass sand and the secondary hydration of the highly reactive admixture significantly reduce the void content. Therefore, the anti-seepage performance of the sprayed concrete is significantly improved.

[0124] The embodiments described above are merely descriptions of preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Without departing from the spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by persons skilled in the art should fall within the scope of protection defined by the claims of the present invention.

Claims

1. A self-sensing sprayed high-performance glass aggregate concrete, characterized in that: Using glass sand to partially replace machine-made sand as the fine aggregate of the self-sensing sprayed high-performance glass aggregate concrete, the amount of the glass sand is 25-75% of the total mass of the fine aggregate; The raw materials of the self-sensing sprayed high-performance glass aggregate concrete are calculated by weight: 749-763 parts of cement, 154-170 parts of fly ash, 154-170 parts of silica fume, 115-125 parts of metakaolin, 840 parts of fine aggregate, 225-255 parts of water, 14.6-19.0 parts of water reducer and 8.75-15.75 parts of carbon fiber; The fine aggregate consists of glass sand and machine-made sand; The particle size of the machine-made sand is 0-4.75 mm, and is not 0; The average particle size of the glass sand is 0.15 mm; The glass sand is prepared by grinding glass material into particles with an average particle size of 0.15 mm, then heating and melting the particles at 730° C. to form microbeads under the action of surface tension.

2. The self-sensing sprayed high-performance glass aggregate concrete according to claim 1, characterized in that: The water reducer is one or more of lignin sulfonate water reducer, naphthalene water reducer, melamine water reducer, aminosulfonate water reducer, aliphatic water reducer and polycarboxylic acid water reducer.

3. The self-sensing sprayed high-performance glass aggregate concrete according to claim 1, characterized in that: The raw materials are calculated by mass as follows: 756 parts of cement, 162 parts of fly ash, 162 parts of silica fume, 120 parts of metakaolin, 210 parts of machine-made sand, 630 parts of glass sand, 240 parts of water, 16.8 parts of water reducer and 15.75 parts of carbon fiber.

4. A method for preparing the self-sensing sprayed high-performance glass aggregate concrete according to any one of claims 1 to 3, characterized in that: The following steps are involved: The self-sensing sprayed high-performance glass aggregate concrete is obtained by mixing the raw materials.

5. Use of the self-sensing sprayed high-performance glass aggregate concrete according to any one of claims 1 to 3 in tunnel lining.

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