Graphene concrete with heat-storage seepage-proofing composite structure and preparation method of graphene concrete

Abstract

The invention discloses graphene concrete with a heat-storage seepage-proofing composite structure and a preparation method of the graphene concrete. The invention relates to graphene concrete with a heat-storage anti-seepage composite structure. The graphene concrete comprises the following components in parts by weight: 900-1100 parts of cement; 530-630 parts by weight of coarse sand; 1310 to 1470 parts by weight of broken stone; 430 to 510 parts by weight of water; and 2-8 parts by weight of graphene. The invention relates to a preparation process of graphene concrete which is composed of cement, coarse sand, common gravel, water and graphene and has a heat-storage seepage-proofing composite structure. The result shows that compared with common concrete, the graphene is doped, so that the multi-aspect performance of the concrete is obviously changed. Specifically, the graphene reinforced concrete has a denser microstructure and more hydration products, and shows excellent mechanical properties, enhanced photo-thermal properties and improved penetration resistance, which verifies the working mechanism of the graphene reinforced concrete.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of building materials, in particular to a graphene concrete with heat storage and anti-seepage composite structure and a preparation method thereof. BACKGROUND

[0002] Concrete is recognized for its sustainability, low cost, and good structural performance, making it the world's leading building material. It is widely used in infrastructure, commercial buildings, and residential construction. However, the continuous growth of the concrete industry has led to an increase in demand for cement and aggregates, resulting in increased carbon dioxide emissions. Therefore, developing high-performance, multifunctional concrete is crucial for promoting a sustainable and resource-saving construction industry.

[0003] Patent publication number CN119774956A discloses an anti-corrosion mass concrete for marine engineering and its preparation method, which has the following raw material composition: cement 250-375 parts, fly ash 25-100 parts, recycled micro powder 20-40 parts, modified weak alkaline anion resin 1-40 parts, machine-made sand 750-900 parts, ordinary crushed stone 900-1000 parts, water 150-200 parts, and water reducing agent 5-20 parts. This patent makes the concrete have good corrosion resistance and is not prone to cracking. However, compared to ordinary anti-corrosion concrete, its unit cost is higher.

[0004] Patent publication number CN115650664A discloses a formula and production method of an environmentally friendly ecological concrete, which has the following raw material composition: cement 50-180 parts, saw mud 30-110 parts, modified sepiolite powder 30-110 parts, phosphogypsum aggregate 900-1500 parts, water reducing agent 5-10 parts, water 70-170 parts, polypropylene potassium 3-8 parts, polyvinyl acetate emulsion 4-9 parts, and 2-methyl-2,4-pentanediol 3-6 parts. This patent recycles industrial waste, making the concrete have both structural performance and ecological functions, including pollutant adsorption, water purification, water permeability, and humidity regulation. However, this material has limitations in compressive strength and pore structure, which may affect the development of plant roots.

[0005] Graphene material has high thermal conductivity, stable lattice structure, excellent thermal conductivity, and significant strength, making it an effective thermal conductivity enhancer. Its excellent mechanical, photothermal, chemical, and electrical properties make it widely used in various fields. Therefore, it is necessary to develop a graphene reinforced concrete to improve the overall performance of concrete. Patent publication number CN106431137A discloses a graphene concrete and its preparation method, which includes the following formula: graphene oxide 0.2-0.5 kg / m 3 , water 150-200 kg / m 3 , cement 395415 kg / m 3, fly ash 50-70 kg / m 3 , silica ash 10-40 kg / m 3 , gravel 1000-1200 kg / m 3 , fine sand 600-700 kg / m 3 , water reducing agent 4.5-7 kg / m 3 The three-dimensional structure formed by the regular growth of cement hydration crystals fills the micro defects of the concrete, thereby improving the mechanical properties and durability of the concrete. However, the preparation process of the concrete is complex, which is not conducive to industrial production.

[0006] Patent publication number CN113372064A discloses a graphene oxide modified cement concrete and a preparation method thereof, which comprises the following components: cement 300-500 parts; fine sand 150-300 parts; medium-coarse sand 100-200 parts; mineral powder 80-110 parts; gravel 1000-1150 parts; concrete fiber 0.6-1.2 parts; graphene oxide 5-15 parts; water reducing agent 5-10 parts; dispersant 4-8 parts; retarder 4-8 parts; water 120-200 parts. By optimizing the components of the graphene oxide modified cement concrete, the technical problems of poor durability and low fluidity of traditional cement concrete are solved, but the characteristics of graphene are not detailed, which may lead to uncontrollable material quality and affect the interface bonding with the concrete. Moreover, the function of the concrete is single, and the research indicators are limited to fluidity and mechanical properties.

[0007] Patent publication number CN113372065A discloses a heat storage concrete and a preparation method thereof, which comprises the following components: cement 220-260 parts, coarse aggregate 900-1100 parts, fine aggregate 800-900 parts, water 140-180 parts, additive 4.8-8 parts, fly ash 80-100 parts, aramid fiber 3-8 parts, graphite 10-15 parts, and microcapsule 5-10 parts. The heat storage concrete has good heat storage performance, high heat storage and release efficiency after multiple cycles, good durability, long service life, and high thermal cycle stability. However, the compatibility of paraffin in the microcapsule with the concrete is poor, which may greatly reduce the heat storage; in addition, like the above research, the microstructure and working mechanism of the concrete are rarely mentioned.

[0008] Therefore, how to simplify the composition and preparation process of graphene reinforced concrete, deeply explore the microstructure and working mechanism of graphene reinforced concrete, and prepare graphene concrete with heat storage and anti-seepage composite structure is a technical problem to be solved at present. SUMMARY

[0009] The present application aims to provide a graphene concrete with heat storage and anti-seepage composite structure and a preparation method thereof. The present application is a preparation process of a graphene concrete with heat storage and anti-seepage composite structure, which is composed of cement, coarse sand, ordinary crushed stone, water and graphene. We studied the influence of different graphene dosages on the performance of the concrete. The results show that, compared with ordinary concrete, the incorporation of graphene significantly changes the performance of the concrete in many aspects. Specifically, graphene-reinforced concrete exhibits a denser microstructure and more hydration products, as well as excellent mechanical properties, enhanced photothermal properties and improved anti-seepage properties.

[0010] In order to achieve the above-mentioned purpose, the present application adopts the following technical solutions:

[0011] The first aspect of the present application is to provide a graphene concrete with heat storage and anti-seepage composite structure, which comprises the following components:

[0012] 900-1100 parts by weight of cement; such as 900, 920, 950, 1000, 1050, 1100 parts by weight of cement

[0013] 530-630 parts by weight of coarse sand; such as 530, 550, 570, 590, 160, 630 parts by weight of coarse sand;

[0014] 1310-1470 parts by weight of crushed stone; such as 1310, 1330, 1350, 1370, 1390, 1410, 1430, 1450, 1470 parts by weight of crushed stone;

[0015] 430-510 parts by weight of water; such as 430, 450, 470, 490, 510 parts by weight of water;

[0016] 2-8 parts by weight of graphene; such as 2, 3, 4, 5, 6, 7, 8 parts by weight of graphene.

[0017] As a preferred embodiment,

[0018] The graphene concrete comprises the following components:

[0019] 950-1050 parts by weight of cement;

[0020] 550-600 parts by weight of coarse sand;

[0021] 1350-1450 parts by weight of crushed stone;

[0022] 450-500 parts by weight of water;

[0023] 2-6 parts by weight of graphene.

[0024] As a preferred embodiment,

[0025] The graphene concrete comprises the following components:

[0026] 970-1030 parts by weight of cement;

[0027] 560-590 parts by weight of coarse sand;

[0028] 1380-1400 parts by weight of gravel;

[0029] 460-490 parts by weight of water;

[0030] 4-6 parts by weight of graphene.

[0031] As a preferred embodiment,

[0032] The graphene concrete comprises the following components:

[0033] 1000 parts by weight of cement;

[0034] 580 parts by weight of coarse sand;

[0035] 1390 parts by weight of gravel;

[0036] 470 parts by weight of water;

[0037] 4-6 parts by weight of graphene.

[0038] The components of the graphene concrete of the present application can be adjusted according to actual needs to meet different concrete strength requirements, and the present application can be researched under the premise of different strength concrete and different graphene content to seek the optimal content of graphene mixed in the conventional strength concrete.

[0039] As a preferred embodiment,

[0040] The graphene is single-layer graphene;

[0041] The cement is P·O42.5R grade ordinary portland cement;

[0042] The particle size of the coarse sand is 1-5mm;

[0043] The particle size of the gravel is 12-15mm.

[0044] Although the coarse sand and the gravel in the present application are both conventional substances in the field, the particle size range is the result of a large number of experiments and optimization in the present application, rather than a simple conventional selection (the particle size of the coarse aggregate is between 4.75-90mm according to the national standard “Building Pebbles and Gravel” (GB / T 14685-2011)), and the existing invention does not combine the particle size range with the performance of the concrete.

[0045] As a preferred embodiment,

[0046] In the Raman spectrum of the graphene, 0.5<=I(D) / I(G)<=1;

[0047] In the Raman spectrum of the graphene, the value of I(2D) / I(G) is greater than or equal to 2;

[0048] The graphene is graphene with a two-dimensional sheet structure.

[0049] The graphene reinforced concrete has a more compact microstructure and more hydration products; this is not mentioned in the prior art.

[0050] The graphene used in the application is provided by Tianjin Jiayin Nanometer Technology Co., Ltd., and the graphene material has a clear two-dimensional sheet structure and good crystallinity.

[0051] The second aspect of the application is to provide a preparation method of graphene concrete with heat storage and anti-seepage composite structure according to the first aspect of the application, comprising the following steps:

[0052] S1, add part of water to the graphene, ultrasonic vibration, homogenization treatment, then add the remaining water, mix uniformly to obtain a graphene dispersion liquid;

[0053] S2, after the cement, coarse sand, gravel and the graphene dispersion liquid are mixed again, pour into a mold, and maintain, a graphene concrete with heat storage and anti-seepage composite structure is obtained.

[0054] As a preferred embodiment,

[0055] In S1, the mass ratio of part of water to the remaining water is 110-150:339;

[0056] The ultrasonic vibration time is 4-5 minutes;

[0057] The homogenization treatment is stirring at a speed of 7950-8050 revolutions per minute for 3-4 minutes by using a high-speed homogenizer.

[0058] As a preferred embodiment,

[0059] In S2, the re-stirring conditions are: stirring at a speed of 950-1050 revolutions per minute for 4-6 minutes.

[0060] The preparation of the concrete in the application needs to be completed within three hours after the preparation of the graphene dispersion liquid.

[0061] As a preferred embodiment,

[0062] The curing conditions of the concrete are: temperature is 18℃, relative humidity is 90%, and curing time is 28 days.

[0063] In this invention, the specific sequence of steps and parameter ranges (such as temperature and stirring speed) in concrete preparation are not disclosed in the prior art, and this selection has a decisive impact on many aspects of the final concrete performance. Insufficient or uneven mixing can directly lead to a decline in overall performance. Multiple steps / parameters in the preparation method are interdependent; for example, ultrasonic vibration and homogenization treatment are indispensable. Concrete preparation needs to be completed within three hours after the preparation of the graphene dispersion; otherwise, graphene deposition will occur, directly affecting the microstructure and overall performance of the concrete. The curing conditions are optimized based on existing specifications and research, and are not a simple combination.

[0064] In this invention, concrete test blocks are prepared within 3 hours after the dispersion is prepared. To prevent water evaporation during the test block formation process, a waterproof film should be immediately applied to the concrete. The curing conditions for the concrete are: temperature of 18°C, relative humidity of 90%, and curing time of 28 days, which yields 100mm concrete test blocks.

[0065] Compared with the prior art, the beneficial effects of the present invention are:

[0066] This invention characterizes the basic features of graphene using Raman spectroscopy and selects high-quality monolayer graphene. Based on this monolayer graphene, the concrete formulation and preparation process can be simplified. The concrete of this invention has a denser microstructure and more hydration products. The addition of monolayer graphene, without affecting the concrete strength, allows graphene to construct a thermally conductive structure within the concrete, enabling rapid heat storage and release when needed; simultaneously, it creates an impermeable structure, achieving a waterproof effect. This invention provides a graphene-reinforced concrete with superior comprehensive performance, including better mechanical properties, better photothermal conversion performance, and improved water permeability. Detailed Implementation

[0067] The present invention will be further described in detail below through specific embodiments.

[0068] Graphene: The quality of graphene was evaluated using the Raman spectroscopy ratios I(D) / I(G) and I(2D) / I(G). I(D) / I(G) = 0.83, and I(2D) / I(G) = 2.66. The graphene's I(D) / I(G) approaching 0 and I(2D) / I(G) greater than 2 indicate good monolayer characteristics, low defect density, and high crystallinity, suggesting the sample is high-quality CVD graphene, meeting its applicability in this study. The graphene material described above was produced by Tianjin Jiayin Nanotechnology Co., Ltd., and was purchased from the company.

[0069] The elemental composition of the graphene was determined by X-ray photoelectron spectroscopy (XPS) analysis, and the curve fitting of the high-resolution XPS spectrum showed that the peak intensities of O, N and C elements were 20455.58, 54383.66 and 215663.8, respectively, and the corresponding binding energies of O, N and C were 532.36 eV, 399.26 eV and 284.83 eV, respectively. Among them, the C1s spectrum peak is particularly prominent, because it represents the 1s electron binding energy of carbon atoms in graphene. The symmetry and sharpness of the C1s peak indicate that the carbon atoms are in a highly uniform sp 2 hybrid state with good crystallinity.

[0070] Ordinary Portland cement, use: as a cementitious material, through the hydration reaction to bond the aggregate (coarse sand, ordinary crushed stone, graphene) to form an integral structure, grade: P·O42.5R grade, brand: Anhui Conch Cement.

[0071] Coarse sand, use: to form a more compact aggregate structure in concrete, thereby improving the compressive strength of concrete, while reducing the porosity of the interior of the concrete, improving the density and impermeability of the concrete, thereby prolonging the service life of the concrete, particle size: 1-5mm.

[0072] Ordinary crushed stone, use: good bonding performance with cement paste, and uniform particle size, combination is more compact, thereby improving the strength and durability of concrete, particle size: 12-15mm.

[0073] Water, ordinary tap water.

[0074] Example 1

[0075] A preparation process of a graphene concrete with heat storage and anti-seepage composite structure is as follows:

[0076] Step 1: Select graphene material produced by Tianjin Jiayin Nanometer Technology Co., Ltd.

[0077] Step 2: The graphene used is subjected to dispersion treatment before being mixed with concrete. The dispersion treatment process is as follows: first, weigh 2 parts by weight of graphene using an analytical balance and place it in a beaker. Then add 131 parts by weight of water and use a 325W ultrasonic material emulsifier to vibrate for 5 minutes. Then use an adjustable high-speed homogenizer to stir at a speed of 8000 revolutions per minute for 3 minutes. Finally, add 339 parts by weight of water and stir the mixture until uniform, thereby preparing a graphene dispersion liquid.

[0078] Step 3: The weighed cement, coarse sand, ordinary gravel, graphene dispersion liquid are mixed to ensure that there are 1000 parts by weight of cement, 580 parts by weight of coarse sand, 1390 parts by weight of ordinary gravel, 470 parts by weight of water, 2 parts by weight of graphene, and the mass ratio of cement to graphene is 1:0.002 respectively. Stir at 1000 rpm for 5 minutes, then pour into the mold coated with release agent. The concrete is slightly higher than the upper edge of the mold, then placed on the vibration table for vibration compaction. The concrete test block is prepared within 3 hours after the dispersion liquid is configured. In order to prevent water evaporation during the formation of the test block, a layer of waterproof film should be immediately covered on the concrete. The curing conditions of the concrete are: temperature is 18℃, relative humidity is 90%, and 100mm concrete test block can be prepared after curing.

[0079] Example 2

[0080] A preparation process of graphene concrete with heat storage and anti-seepage composite structure is as follows:

[0081] Step 1: Select graphene material produced by Tianjin Jiayin Nanotechnology Co., Ltd.

[0082] Step 2: The graphene used is dispersed before mixing with concrete. The dispersion process is as follows: first, weigh 4 parts by weight of graphene using an analytical balance and place it in a beaker. Then add 131 parts by weight of water and use a 325W ultrasonic material emulsifier to vibrate for 5 minutes. Then use an adjustable high-speed homogenizer to stir at 8000 rpm for 3 minutes. Finally, add 339 parts by weight of water and stir the mixture until uniform, thereby preparing a graphene dispersion liquid.

[0083] Step 3: The weighed cement, coarse sand, ordinary gravel, graphene dispersion liquid are mixed to ensure that there are 1000 parts by weight of cement, 580 parts by weight of coarse sand, 1390 parts by weight of ordinary gravel, 470 parts by weight of water, 4 parts by weight of graphene, and the mass ratio of cement to graphene is 1:0.004 respectively. Stir at 1000 rpm for 5 minutes, then pour into the mold coated with release agent. The concrete is slightly higher than the upper edge of the mold, then placed on the vibration table for vibration compaction. The concrete test block is prepared within 3 hours after the dispersion liquid is configured. In order to prevent water evaporation during the formation of the test block, a layer of waterproof film should be immediately covered on the concrete. The curing conditions of the concrete are: temperature is 18℃, relative humidity is 90%, and 100mm concrete test block can be prepared after curing.

[0084] Example 3

[0085] A preparation process of graphene concrete with heat storage and anti-seepage composite structure is as follows:

[0086] Step 1: Select graphene material produced by Tianjin Jiayin Nanotechnology Co., Ltd.

[0087] Step 2: The graphene used is dispersed before mixing with the concrete. The dispersion process is as follows: first, 6 parts by weight of graphene is weighed using an analytical balance and placed in a beaker. Then 131 parts by weight of water is added and vibrated for 5 minutes using a 325W ultrasonic material emulsifier. Then, an adjustable high-speed homogenizer is used to stir at 8000 rpm for 3 minutes. Finally, 339 parts by weight of water is added and the mixture is stirred until uniform, thereby preparing a graphene dispersion liquid.

[0088] Step 3: The weighed cement, coarse sand, ordinary gravel, and graphene dispersion liquid are mixed, ensuring that there are 1000 parts by weight of cement, 580 parts by weight of coarse sand, 1390 parts by weight of ordinary gravel, 470 parts by weight of water, and 6 parts by weight of graphene, corresponding to a mass ratio of cement to graphene of 1:0.006. Stir at 1000 rpm for 5 minutes, then pour into a mold coated with a release agent. The concrete is slightly higher than the upper edge of the mold, then placed on a vibrating table for vibration compaction. The concrete test block is prepared within 3 hours after the dispersion liquid is prepared. In order to prevent water evaporation during the formation of the test block, a layer of waterproof film should be immediately covered on the concrete. The curing conditions of the concrete are: temperature of 18℃, relative humidity of 90%, and after curing, 100mm concrete test blocks can be prepared.

[0089] Example 4

[0090] A preparation process of graphene concrete with heat storage and anti-seepage composite structure is as follows:

[0091] Step 1: Select graphene material produced by Tianjin Jiayin Nanotechnology Co., Ltd.

[0092] Step 2: The graphene used is dispersed before mixing with the concrete. The dispersion process is as follows: first, 6 parts by weight of graphene is weighed using an analytical balance and placed in a beaker. Then 131 parts by weight of water is added and vibrated for 5 minutes using a 325W ultrasonic material emulsifier. Then, an adjustable high-speed homogenizer is used to stir at 8000 rpm for 3 minutes. Finally, 339 parts by weight of water is added and the mixture is stirred until uniform, thereby preparing a graphene dispersion liquid.

[0093] Step 3: The weighed cement, coarse sand, ordinary gravel, graphene dispersion liquid are mixed to ensure that there are 1000 parts by weight of cement, 580 parts by weight of coarse sand, 1390 parts by weight of ordinary gravel, 470 parts by weight of water, and 8 parts by weight of graphene, and the mass ratio of cement to graphene is 1:0.008, respectively. Stir at a speed of 1000 revolutions per minute for 5 minutes, then pour into a mold coated with a release agent. The concrete is slightly higher than the upper edge of the mold, then placed on a vibrating table for vibration compaction. The concrete test block is prepared within 3 hours after the dispersion liquid is configured. In order to prevent water evaporation during the formation of the test block, a layer of waterproof film should be immediately covered on the concrete. The curing conditions of the concrete are: temperature is 18℃, relative humidity is 90%, and 100mm concrete test block can be prepared after curing.

[0094] Comparative Example 1

[0095] A preparation process of a graphene concrete with heat storage and anti-seepage composite structure is as follows:

[0096] The weighed cement, coarse sand, ordinary gravel, water are mixed to ensure that there are 1000 parts by weight of cement, 580 parts by weight of coarse sand, 1390 parts by weight of ordinary gravel, 470 parts by weight of water, and 0 parts by weight of graphene, and the mass ratio of cement to graphene is 1:0, respectively. Stir at a speed of 1000 revolutions per minute for 5 minutes, then pour into a mold coated with a release agent. The concrete is slightly higher than the upper edge of the mold, then placed on a vibrating table for vibration compaction. The concrete test block is prepared within 3 hours after the dispersion liquid is configured. In order to prevent water evaporation during the formation of the test block, a layer of waterproof film should be immediately covered on the concrete. The curing conditions of the concrete are: temperature is 18℃, relative humidity is 90%, and 100mm concrete test block can be prepared after curing.

[0097] Comparative Example 2

[0098] A preparation process of a graphene concrete with heat storage and anti-seepage composite structure is as follows:

[0099] It uses basically the same preparation method as Example 2, the only difference is that the graphene I(D) / I(G) = 2.1, I(2D) / I(G) is about 0.9, that is, I(D) / I(G) is greater than 1, I(2D) / I(G) is less than 1, and the graphene has the characteristics of multi-defect and few layers.

[0100] Comparative Example 3

[0101] A preparation process of a graphene concrete with heat storage and anti-seepage composite structure is as follows:

[0102] The preparation method is substantially the same as that of Example 2, and the only difference is that the graphene used has I(D) / I(G) approximately equal to 0.3 and I(2D) / I(G) approximately equal to 1.7, i.e. I(D) / I(G) is in the range of 0.1-0.5 and I(2D) / I(G) is in the range of 1.5-2, and the graphene has the characteristics of low-defect double layers.

[0103] Test Example 1

[0104] The compressive strength of the graphene reinforced concrete prepared in the application is tested according to the Standard for Testing Methods of Physical and Mechanical Properties of Concrete GB / T 50081-2019.

[0105] Mechanical property test: the compressive strength of the test piece is evaluated on the 3rd, 7th and 28th day of curing. The UH-200 rock pressure testing machine produced by Youhongya Measurement and Control Technology Co., Ltd. is used to test the compressive strength of the cubic test block. The loading rate is set to 0.5 MPa / s, the loading method is force loading, and the oil temperature is maintained at 29℃. The test is terminated when the peak force reaches 30% of the failure. The failure process is monitored and recorded before and after the test block reaches 40% of the peak strength. The test results are shown in Table 1.

[0106] Table 1

[0107]

[0108] As can be seen from the results in Table 1, the compressive strength of the concrete of the example is significantly improved compared to the results of Comparative Example 1 when cured for 28 days, but the concentration of the graphene dispersion should not be too high, otherwise it will reduce the strength of the test block.

[0109] In addition, as can be seen from the results in Table 1, in terms of mechanical properties, after 28 days of curing, the incorporation of a certain amount of graphene improves the elastic modulus of the concrete, enabling it to effectively withstand and transmit stress, thereby improving the compressive strength of the material. This improvement is because graphene, while effectively transmitting stress and enhancing the toughness of the concrete, also promotes crack bridging and improves hydration, thereby improving the compressive strength. The appropriate concentration of graphene dispersion is crucial, and a high concentration will result in a decrease in the strength of the concrete. When the content of graphene is too high, it will aggregate, resulting in uneven dispersion. Due to the coating of cement particles, this clumping will interfere with the cement hydration process and can cause additional pores and weak interfaces to form due to accumulation, ultimately reducing the compressive strength of the concrete. Therefore, the relationship between the content of graphene and the compressive strength is complex and is affected by multiple mechanisms, and the content of graphene and the strength of the concrete are not linearly related.

[0110] Test Example 2

[0111] Photo-thermal performance test:

[0112] The photothermal experiments were performed on the five test blocks with the same curing time but different graphene contents in Comparative Example 1, Example 1-Example 4. The experimental device includes a thermocouple thermometer (model: RE-Y2101B) of People's Electrical Appliance Group Co., Ltd., a temperature sensor, and a reflective indoor heater (rated power: 700W, model: RSN22-S07J) of Guangdong Rongsheng Electrical Appliance Co., Ltd. The temperature sensor is embedded in the front (with the face facing away from the reflective indoor heater as the front), back, upper, and left four positions of each test block, respectively, to monitor temperature changes from multiple directions. During the entire experiment, the distance between the reflective indoor heater and the test block remains constant. After preheating for 1 minute, the infrared light source irradiates the test block for 10 minutes, and the temperature is recorded every 30 seconds. After irradiation, the indoor reflective heater is turned off, and the temperature is recorded every 30 seconds for 10 minutes. In order to minimize potential experimental errors, the test is performed simultaneously over three consecutive days. The test results are shown in Table 2.

[0113] Table 2

[0114]

[0115]

[0116] As can be seen from the results in Table 2, the temperature of the rear surface of the concrete with graphene added in the examples of the present application is significantly improved compared to the results of Comparative Example 1, indicating that graphene helps to improve the heat absorption capacity of the concrete.

[0117] The temperature of the upper surface of the concrete with graphene added in the examples of the present application is significantly reduced compared to the results of Comparative Example 1, indicating that graphene helps to improve the heat release capacity of the concrete.

[0118] As can also be seen from the results in Table 2, in terms of photothermal performance, the high specific surface area of graphene enables the concrete to absorb and store a large amount of heat, while effectively dispersing the heat to one side of the wall, thereby preventing local heat accumulation. In addition, graphene has a broad spectrum of light absorption capability (covering ultraviolet, visible, and infrared wavelengths), which greatly enhances the ability of the wall to capture sunlight. When there is a large temperature difference between the indoor and outdoor environments, heat is conducted through the wall, and graphene helps to distribute the heat more evenly within the wall structure. Excessive graphene can lead to the formation of micron-sized clumps, thereby reducing the specific surface area. This aggregation can also cause light scattering, resulting in a decrease in the effective path of photothermal conversion. In addition, poor interfaces between aggregates and the cement matrix can form a thermal resistance layer, ultimately weakening the overall heat transfer efficiency.

[0119] Test Example 3

[0120] Impermeability test: In this study, the method described in the literature was used. Five completely dried test blocks in Comparative Example 1, Example 1-4 were immersed in water, and the initial water level was set at 2.5 cm above the bottom of the test block. The soaking time in water was 7 days, and the maximum immersion depth k (the difference between the final immersion height and the initial immersion height) of each test piece was recorded. The area of the test block surface that was immersed in water to reach the maximum immersion depth was named the seepage area S. The k and S were quantitatively evaluated, and the effect of graphene on the impermeability of concrete was discussed. The test results are shown in Table 2.

[0121] Table 3

[0122] Experimental protocol k (cm) [S (cm 2 )]]> Comparative example 1 1.5 29.5 Example 1 1.0 25 Example 2 0.5 25 Example 3 0.8 26 Example 4 0.9 30 Comparative example 2 1.2 28 Comparative example 3 1.0 29

[0123] As can be seen from the results in Table 3, the maximum immersion depth k and the seepage area S of the concrete with graphene added in the examples of the present application are significantly lower than those of Comparative Example 1, indicating that graphene helps to improve the impermeability of concrete. This is because graphene can effectively fill the internal pores of concrete, improve the microstructure of concrete, and make the concrete have a certain impermeability. It can also induce the directional growth of C-S-H gel in the cement on its surface to form a more dense network structure, thereby effectively reducing the ion penetration path. However, the concentration of graphene dispersion should not be too high, as too much graphene can form a weak interface, interface defects, and agglomeration in the local area of the concrete, resulting in a decrease in impermeability and a significant increase in permeation area.

[0124] As can be seen from the results in Table 3, in terms of impermeability, graphene effectively fills the internal pores of concrete, enhances its microstructure, and thus improves the impermeability of concrete. In addition, graphene promotes the directional growth of C-S-H gel on its surface to form a more dense network structure, significantly reducing the ion penetration path. There is an optimal dosage range for graphene to enhance the impermeability of concrete. Within this range, graphene is uniformly dispersed, and when the mass ratio of cement to graphene is 1:0.04, the impermeability is most significantly improved. However, when the mass ratio of cement to graphene increases to 1:0.08, the impermeability of the test block decreases due to the formation of local weak interfaces, interface defects, and agglomeration of graphene, resulting in a significant increase in permeation area.

[0125] Test Example 4

[0126] Graphene reinforced concrete: To investigate the effect of graphene on the microstructure of hydrated concrete, scanning electron microscopy (SEM) was used to compare the microstructural characteristics of ordinary concrete (Comparative Example 1) and the concrete specimens of Examples 1-4 with different graphene contents after 28 days of curing. The SEM analysis was performed on cross-section thin sections (size of about 5 mm x 2 mm) with the sampling focused on the interfacial transition zone between the aggregate and the mortar and the bonding area of the coarse aggregate. The brand and model of the instrument used was Zeiss G360, provided by Zhengzhou Quantum Detection Technology Center. The results of the detection images showed that the cross-sectional morphology of ordinary concrete exhibited significant roughness and obvious cracks at both 200 pm and 20 pm scales. At a higher resolution (2 pm scale), the hydration products showed a mainly loose and disordered lamellar structure. In contrast, the graphene reinforced concrete of the present application exhibited a smoother cross-section, no observable cracks and a more dense microstructure at the same magnification (200 pm and 20 pm). At a 2 pm scale, the graphene reinforced concrete showed higher and more ordered hydration products. At the same time, thermogravimetric analysis (TG) was performed on the graphene reinforced concrete to evaluate the effect of graphene on the durability of the concrete. For this purpose, the concrete fragments with different graphene contents were ground into uniform powders (particle size < 100 pm). The TG measurement was performed under a nitrogen atmosphere with a heating rate of 20 °C / min and a temperature range of 40-1000 °C. To ensure reproducibility, three repeated analyses were performed for each sample type. The instrument used was a thermogravimetric analyzer (TGA / DSC 3+, HKG), provided by Beijing Hengju Experimental Equipment Co., Ltd. TG revealed different mass loss stages of the concrete test blocks within a specific temperature range. Between 150 and 400 °C, the main mass loss was due to the dehydration of calcium silicate hydrate gel (C-S-H), which is the main hydration product of cement. Subsequently, from 400 to 600 °C, the decomposition of calcium hydroxide (CH) led to the observed mass reduction, while the decarburization of calcium carbonate (CaCO3) dominated between 600 and 1000 °C. Residual mass analysis showed that the graphene reinforced concrete of the present application exhibited a higher proportion of CH and C-S-H compared to ordinary concrete, indicating more hydration product formation and a more dense microstructure. Especially at a cement to graphene mass ratio of 1:0.006, the DTG peak intensity decreased most significantly, indicating the inhibitory effect of graphene on the local rapid pyrolysis caused by microcrack propagation. The DTG curve showed a significant peak near 600 °C, confirming the substantial effect of graphene on the thermal stability of the concrete. The change in peak characteristics highlights the role of graphene in regulating the decomposition kinetics of the concrete at high temperatures. In summary, the microstructure characterization revealed that the graphene modified concrete of the present application exhibited a more dense microstructure.

[0127] In conclusion, the basic characteristics of graphene are characterized by using Raman spectrum, and single-layer graphene with high quality is selected, and based on the single-layer graphene, the formula and preparation process of the concrete can be more simplified. In the concrete of the application, the single-layer graphene is added without affecting the strength of the concrete, and the graphene builds a heat conduction structure in the concrete, so that the heat can be quickly stored, and when needed, the heat can be quickly conducted and released; meanwhile, an anti-permeation structure can be built to achieve the effect of anti-permeation. The graphene concentration of the embodiment 2-3 is moderate, and the best balance among the strength, anti-permeation and photothermal performance is achieved. The graphene reinforced concrete has great application potential in the field of future building.

[0128] The above examples are only examples for clearly illustrating the application, and are not intended to limit the embodiments. Based on the above description, other different forms of changes or variations can be made by those skilled in the art. Here, all the embodiments cannot be exhausted, and the obvious changes or variations derived therefrom are still within the protection scope of the application.

Claims

1. A graphene concrete with a heat storage and seepage prevention composite structure, characterized in that, The graphene concrete comprises the following components: 900-1100 parts by weight of cement; 530-630 parts by weight of coarse sand; 1310-1470 parts by weight of crushed stone; 430-510 parts by weight of water; 2-8 parts by weight of graphene.

2. The graphene concrete with a heat storage and seepage prevention composite structure according to claim 1, characterized in that, The graphene concrete comprises the following components: 950-1050 parts by weight of cement; 550-600 parts by weight of coarse sand; 1350-1450 parts by weight of crushed stone; 450-500 parts by weight of water; 2-6 parts by weight of graphene.

3. The graphene concrete with a heat storage and seepage prevention composite structure according to claim 1, characterized in that, The graphene concrete comprises the following components: 970-1030 parts by weight of cement; 560-590 parts by weight of coarse sand; 1380-1400 parts by weight of crushed stone; 460-490 parts by weight of water; 4-6 parts by weight of graphene.

4. The graphene concrete with a heat storage and seepage prevention composite structure according to claim 1, characterized in that, The graphene concrete comprises the following components: 1000 parts by weight of cement; 580 parts by weight of coarse sand; 1390 parts by weight of crushed stone; 470 parts by weight of water; 4-6 parts by weight of graphene.

5. The graphene concrete with a heat storage and seepage prevention composite structure according to claim 1. Its characteristic is that... The graphene is a single-layer graphene; The cement is P·O42.5R grade ordinary Portland cement; The coarse sand has a particle size of 1-5 mm; The particle size of the crushed stone is 12-15 mm.

6. The graphene concrete with a heat storage and seepage prevention composite structure according to claim 5, characterized in that, In the Raman spectrum of the graphene, 0.5 ≤ I(D) / I(G) ≤ 1; In the Raman spectrum of the graphene, the I(2D) / I(G) value is ≥2; The graphene is graphene with a two-dimensional sheet structure.

7. A method for preparing graphene concrete with a heat storage and seepage prevention composite structure as described in any one of claims 1-6, characterized in that, Includes the following steps: S1. Add some water to graphene, vibrate ultrasonically, homogenize, add the remaining water, mix evenly, and obtain graphene dispersion. S2. After mixing the cement, coarse sand, crushed stone and graphene dispersion again, pour it into the mold and cure it to obtain graphene concrete with a heat storage and seepage prevention composite structure.

8. The method for preparing graphene concrete with a heat storage and seepage prevention composite structure according to claim 7, characterized in that, In S1, the mass ratio of some water to the remaining water is 110-150:339; The duration of ultrasonic vibration is 4-5 minutes; The homogenization process involves using a high-speed homogenizer to stir the mixture at a speed of 7950-8050 rpm for 3-4 minutes.

9. The method for preparing graphene concrete with a heat storage and seepage prevention composite structure according to claim 7, characterized in that, In S2, the conditions for stirring again are: stirring at a speed of 950-1050 rpm for 4-6 minutes.

10. The method for preparing graphene concrete with a heat storage and seepage prevention composite structure according to claim 7, characterized in that, The curing conditions for the concrete are: temperature of 18℃, relative humidity of 90%, and curing time of 28 days.

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