Concrete based on modified shale ceramsite and preparation method thereof

Abstract

The present invention belongs to the field of building materials technology and relates to a concrete based on modified shale ceramsite and its preparation method. The present invention provides a method for preparing concrete based on modified shale ceramsite, comprising: immersing the shale ceramsite in a 1-5wt% ethyl cellulose solution, removing it and curing it at 160-180°C, mixing it with a 10-20wt% phenolic resin solution, and after complete evaporation of the solvent, removing it and curing it at 140-160°C to produce the modified shale ceramsite; and uniformly mixing the modified shale ceramsite, cement, and fine aggregate, then adding water, a water reducer, and an air entraining agent, and stirring thoroughly to produce the concrete. The present invention aims to address the technical problem that the high density of shale ceramsite and cement mortar causes concrete containing shale ceramsite to easily delaminate, exhibit high slump loss, and exhibit high water absorption, which can lead to cracking.

Description

Technical Field

[0001] The invention belongs to the technical field of building materials and relates to concrete based on modified shale ceramsite and a preparation method thereof. Background Art

[0002] Lightweight aggregate concrete (LAC) is a type of concrete that uses lightweight, porous aggregates instead of traditional sand and gravel. Ceramsite concrete is the most common type, while zeolite and coal gangue-based lightweight aggregates are less common. Ceramsite concrete's unique structure gives it a significantly different source of strength than conventional concrete. Studies have shown that in conventional concrete of average strength, aggregate strength is largely unutilized, and concrete failure is determined by the interface transition zone between the other two concrete phases—cement paste and hardened cement paste—and the aggregate. Therefore, in conventional concrete, the strength of coarse aggregate particles has no significant impact on concrete strength. However, the opposite is true for ceramsite concrete. Ceramsite's strength and elastic modulus are often lower than those of the cement mortar matrix. When compressive loads act on ceramsite particles, compressive stresses are generated on both sides of the aggregate. Furthermore, the rough surface of ceramsite and its large specific surface area provide strong adhesion to the cement mortar, making interfacial cracking less likely to occur. The "micro-pump" effect of ceramsite in concrete absorbs some water, reducing the water-cement ratio at the aggregate interface and eliminating water pockets similar to those under ordinary coarse aggregate, i.e., internal stratification of concrete, thereby improving the density of the cement paste and its interface. During the long-term hydration process, the water absorbed by the ceramsite will be released again, continuously providing moisture for the unhydrated cement particles, further filling the pores in the interface transition zone between the ceramsite and concrete, and increasing the interfacial adhesion. At the same time, as the water migrates outward, a certain "self-vacuum" is formed inside the ceramsite, which also improves the strength of the ceramsite concrete. Shale ceramsite concrete is a ceramsite concrete with shale ceramsite as the main aggregate material. It has excellent lightweight, thermal insulation, compression resistance, and crack resistance, and the changes in strength and deformation properties are relatively stable.

[0003] The lightweight aggregate of ceramsite concrete significantly impacts its workability. For freshly mixed ceramsite concrete, good workability primarily refers to good fluidity and a lack of segregation. Existing research indicates that key techniques for producing ceramsite concrete with excellent workability include controlling the particle size of the ceramsite, adding viscosity-enhancing and plastic-retaining admixtures and air-entraining agents, installing a grid to inhibit ceramsite flotation, and optimizing mix parameters. Because ceramsite tends to float, resulting in poor mix stability, ceramsite concrete should not exhibit excessive fluidity. Therefore, the mixing, pouring, and vibration techniques for ceramsite concrete differ from those for conventional concrete. Proper mixing and vibration procedures not only improve the workability of ceramsite concrete but also contribute to increased strength. The pre-wetting process for ceramsite also significantly impacts its workability. Pre-wetting not only improves concrete workability and reduces slump loss over time, but also plays a significant role in its mechanical properties, volume stability, and durability. However, the determination of pre-wetting time is largely empirical and lacks scientific basis, impacting the performance consistency of multiple batches of concrete. Summary of the Invention

[0004] The present invention aims to address the technical problem that shale ceramsite and cement mortar have high densities, resulting in concrete containing shale ceramsite being prone to stratification and segregation, large slump loss, and high water absorption, which can lead to cracks. To this end, the present invention provides a concrete based on modified shale ceramsite and a method for preparing the same to address this need in the art. The present invention uses ethyl cellulose and phenolic resin to synergistically modify shale ceramsite, producing a dense, compact surface layer on the surface of the shale ceramsite with certain hydrophobic properties. This maintains the lightweight characteristics of the shale ceramsite while increasing its particle strength and reducing its water absorption, ultimately improving the stability of the concrete and preventing the occurrence of cracks.

[0005] In one aspect, the present invention relates to a method for preparing concrete based on modified shale ceramsite, comprising: immersing the shale ceramsite in a 1-5 wt% ethyl cellulose solution, curing the shale ceramsite at 160-180° C. after removal, mixing the shale ceramsite with a 10-20 wt% phenolic resin solution, and curing the shale ceramsite at 140-160° C. after the solvent is completely volatilized, thereby preparing the modified shale ceramsite;

[0006] The modified shale ceramsite, cement and fine aggregate are uniformly mixed, and then water, a water reducing agent and an air entraining agent are added and fully stirred to obtain the concrete.

[0007] Optionally, the cement is at least one of ordinary Portland cement, slag-based polymer cement, alkali-activated slag cement or sulphoaluminate cement.

[0008] Generally, in the method for preparing concrete based on modified shale ceramsite provided by the present invention, admixtures are not limited to water reducers and air entraining agents, and may also include defoamers and early strength agents.

[0009] Illustratively, the water reducer is a naphthalene-based high-efficiency water reducer, a lignin sulfonate sodium salt water reducer, an amino-based high-efficiency water reducer, and a polycarboxylic acid-based high-efficiency water reducer; the air entraining agent is a rosin resin-based air entraining agent, an alkyl-based air entraining agent, and a sulfonic acid-based air entraining agent; the defoaming agent is an organosilicon-based defoaming agent, a polyether-based defoaming agent, and a polyether-modified polysiloxane-based defoaming agent; and the early strength agent is nitrite, calcium formate, a composite early strength agent, and triethanolamine.

[0010] Furthermore, in the method for preparing concrete based on modified shale ceramsite provided by the present invention, 30 to 60 mL of the phenolic resin solution is added to every 50 g of shale ceramsite.

[0011] Furthermore, in the preparation method of concrete based on modified shale ceramsite provided by the present invention, the raw materials of the concrete include, by mass: 470-510 parts of modified shale ceramsite, 450-530 parts of cement, 580-620 parts of fine aggregate, 3-6 parts of water reducer, 0.5-1 part of air entraining agent, and 180-210 parts of water.

[0012] Furthermore, in the preparation method of concrete based on modified shale ceramsite provided by the present invention, the raw materials of the concrete include, by mass: 492 parts of modified shale ceramsite, 500 parts of cement, 608 parts of fine aggregate, 5.27 parts of water reducer, 0.73 parts of air entraining agent, and 184 parts of water.

[0013] Furthermore, in the method for preparing concrete based on modified shale ceramsite provided by the present invention, the fine aggregate is a mixture of natural sand and artificial sand, and the fineness modulus is 2.65.

[0014] Furthermore, in the method for preparing concrete based on modified shale ceramsite provided by the present invention, the solvent of the ethyl cellulose solution or the phenolic resin solution is independently selected from at least one of chloroform, ethanol or methanol.

[0015] Furthermore, in the preparation method of concrete based on modified shale ceramsite provided by the present invention, the curing time after the shale ceramsite is immersed in the ethyl cellulose solution and taken out is 1.5 to 3 hours, and the curing time after the solvent is completely volatilized and taken out is 4 to 8 hours.

[0016] Furthermore, in the method for preparing concrete based on modified shale ceramsite provided by the present invention, the particle size of the shale ceramsite is not higher than 16 mm.

[0017] On the other hand, the present invention relates to a concrete based on modified shale ceramsite, which is prepared by adopting the preparation method of the concrete based on modified shale ceramsite.

[0018] Compared with the prior art, the technical solution provided by the present invention has at least the following beneficial effects or advantages:

[0019] The present invention forms a dense hydrophobic layer on the surface of shale ceramsite through the synergistic modification mechanism of ethyl cellulose and phenolic resin, fundamentally optimizing the performance of concrete. Ethyl cellulose, as a film-forming agent, is dissolved in solvents such as ethanol and then penetrates into the pores of shale ceramsite. After curing at 160-180°C, it forms a uniform coating, significantly reducing the surface hydrophilicity. The phenolic resin solution subsequently introduced undergoes a polycondensation reaction when cured at 140-160°C, cross-linking with active groups such as hydroxyl groups on the surface of ethyl cellulose and shale ceramsite to form a three-dimensional network structure, further enhancing the surface density and hydrophobicity. This dual modification not only blocks the water absorption channels of shale ceramsite, but also effectively inhibits aggregate floating and cement paste segregation by improving particle strength and interfacial adhesion. The present invention achieves breakthroughs in lightweight, crack resistance, and workability through the synergistic effects of surface chemical modification and physical structure optimization. DETAILED DESCRIPTION

[0020] The technical solutions of the present invention are described below with reference to the following examples. However, the present invention is not limited to the following examples. The experimental methods and detection methods described in each example are conventional methods unless otherwise specified; the reagents and materials described are commercially available unless otherwise specified. The percentages in the following examples are percentages by mass unless otherwise specified. The ratios in the following examples are ratios by mass unless otherwise specified.

[0021] In the following examples, the cement used was ordinary Portland cement, bagged PO 42.5, produced by Gezhouba Group Cement Co., Ltd.; the fine aggregate was a mixture of natural and manufactured sand with a fineness modulus of 2.65; the water reducer was the high-efficiency retarding water reducer G454 produced by Kunming Baiyi Building Materials Manufacturing Co., Ltd.; and the air-entraining agent was concrete air-entraining agent AE-1450, purchased from Nanjing Xinhai Trading Co., Ltd. Ethyl cellulose, with an ethoxy content of 48.0-49.5%, was purchased from Shandong Xuchen Chemical Technology Co., Ltd. Phenolic resin, with a molecular weight of 122.12134, was purchased from Shandong Guohua Chemical Co., Ltd.

[0022] Shale ceramsite, particle size 8~15mm, bulk density 530kg / m 3 , apparent density 700kg / m 3 , 24h water absorption rate is 14%, cylinder pressure strength is 3.2MPa, needle-like content is less than 10%, mud content is less than 1%, which meets the technical requirements of GB / T 17431.1-2010 "Light aggregate and its test methods Part 1: Light aggregate" standard.

[0023] Example 1

[0024] This embodiment provides a preparation process of modified shale ceramsite.

[0025] Modified shale ceramsite #1: Prepare a 1wt% ethyl cellulose ethanol solution; after washing the shale ceramsite, dry it at 120℃ for 3h, then place it in a container, fully immerse it in the 1wt% ethyl cellulose ethanol solution, press it with a grid, and leave it for 12h; remove the particles and filter out the excess liquid, then place it in a container at room temperature for 24h, and place it in an oven at 160℃ for curing for 1.5h, paying attention to continuous stirring to prevent the particles from clumping; remove the cured particles and place them in a blender, keep stirring, and add 30mL of 10wt% phenolic resin ethanol solution for every 50g of shale ceramsite; after the solvent is completely evaporated, remove the particles and place them in an oven at 140℃ for curing for 4h to obtain modified shale ceramsite.

[0026] Modified shale ceramsite #2: Prepare a 1wt% ethyl cellulose ethanol solution; after washing the shale ceramsite, dry it at 120℃ for 3h, then place it in a container, fully immerse it in the 1wt% ethyl cellulose ethanol solution, press it with a grid, and leave it for 12h; remove the particles and filter out the excess liquid, then place them in a container at room temperature for 24h, and place them in an oven at 160℃ for 2h. Pay attention to continuous stirring to prevent the particles from clumping; remove the solidified particles and place them in a blender, keep stirring, and add 40mL of 14wt% phenolic resin ethanol solution for every 50g of shale ceramsite; after the solvent is completely evaporated, remove the particles and place them in an oven at 140℃ for 6h to obtain modified shale ceramsite.

[0027] Modified shale ceramsite #3: Prepare a 2wt% ethyl cellulose ethanol solution; after washing the shale ceramsite, dry it at 120℃ for 3h, then place it in a container, fully immerse it in the 2wt% ethyl cellulose ethanol solution, press it with a grid, and leave it for 12h; remove the particles and filter out excess liquid, then place them in a container at room temperature for 24h, and place them in an oven at 160℃ for curing for 3h, paying attention to continuous stirring to prevent the particles from clumping; remove the cured particles and place them in a blender, keep stirring, and add 50mL of 18wt% phenolic resin ethanol solution for every 50g of shale ceramsite; after the solvent is completely evaporated, remove the particles and place them in an oven at 140℃ for curing for 8h to obtain modified shale ceramsite.

[0028] Modified shale ceramsite #4: Prepare a 5wt% ethyl cellulose ethanol solution; after washing the shale ceramsite, dry it at 120℃ for 3h, then place it in a container, fully immerse it in the 5wt% ethyl cellulose ethanol solution, press it with a grid, and leave it for 12h; remove the particles and filter out the excess liquid, then place it in a container at room temperature for 24h, and place it in an oven at 180℃ for 3h to cure, paying attention to continuous stirring to prevent the particles from clumping; remove the cured particles and place them in a blender, keep stirring, and add 60mL of 20wt% phenolic resin ethanol solution for every 50g of shale ceramsite; after the solvent is completely evaporated, remove the particles and place them in an oven at 160℃ for 8h to obtain modified shale ceramsite.

[0029] Modified shale ceramsite #5: Prepare a 5wt% ethyl cellulose ethanol solution; after washing the shale ceramsite, dry it at 120℃ for 3h, then place it in a container, fully immerse it in the 5wt% ethyl cellulose ethanol solution, press it with a grid, and leave it for 12h; remove the particles and filter out the excess liquid, then place it in a container at room temperature for 24h, and place it in an oven at 180℃ for curing for 3h, paying attention to continuous stirring to prevent the particles from clumping; remove the cured particles and place them in a blender, keep stirring, and add 60mL of 80wt% phenolic resin ethanol solution for every 50g of shale ceramsite; after the solvent is completely evaporated, remove the particles and place them in an oven at 160℃ for curing for 8h to obtain modified shale ceramsite.

[0030] Modified shale ceramsite #6: Prepare a 0.1wt% ethyl cellulose ethanol solution; after washing the shale ceramsite, dry it at 120℃ for 3h, then place it in a container, fully immerse it in the 0.1wt% ethyl cellulose ethanol solution, press it with a grid, and leave it for 12h; remove the particles and filter out the excess liquid, then place it in a container at room temperature for 24h, and place it in an oven at 180℃ for 3h to cure, paying attention to continuous stirring to prevent the particles from clumping; remove the cured particles and place them in a blender, keep stirring, and add 60mL of 1wt% phenolic resin ethanol solution for every 50g of shale ceramsite; after the solvent is completely evaporated, remove the particles and place them in an oven at 160℃ for 8h to cure to obtain modified shale ceramsite.

[0031] The present invention uses ethyl cellulose solution to modify the surface of shale ceramsite to improve its hydrophobic properties. When heated or under acidic conditions, phenolic resin can undergo polycondensation between hydroxymethyl groups and between hydroxymethyl groups and phenol or substituted phenol at the ortho and para positions, cross-linking to form a high-hardness bulk polymer. At the same time, phenolic resin can react with ethyl cellulose and reactive groups present on the surface of shale ceramsite, thereby improving the compatibility between the modified product and the shale ceramsite, and ultimately producing a dense and compact surface layer on the surface of the shale ceramsite with certain hydrophobic properties, thereby maintaining the lightweight characteristics of the shale ceramsite while improving its particle strength and reducing water absorption, ultimately improving the stability of the concrete and avoiding the occurrence of cracks. Note that when preparing the modified shale ceramsite, no curing agent or coupling agent is needed. If a curing agent is added, the shale ceramsite will be attached with too much ethyl cellulose and phenolic resin, resulting in pore blockage, reduced surface roughness, and reduced bonding strength.

[0032] Example 2

[0033] This embodiment provides a preparation process of concrete based on modified shale ceramsite.

[0034] Since this embodiment intends to verify the improvement effect of modified shale ceramsite on concrete, the modified shale ceramsite or shale ceramsite is not pre-wetted in advance during preparation.

[0035] Concrete 1#: In parts by mass, 470 parts of modified shale ceramsite #1, 450 parts of cement, and 580 parts of fine aggregate were stirred in a mixer for 15 seconds. Then, 3 parts of water reducer, 0.5 parts of air entraining agent, and 180 parts of water were poured into the mixer and stirred evenly for 2 minutes. The concrete was placed with a trowel into a test mold (a concrete prism specimen of 100 mm × 100 mm × 300 mm) that had been brushed with lubricating oil in advance. A vibrator was used to eliminate internal bubbles. The concrete was removed from the mold after standing for 24 hours and then subjected to standard curing for 28 days.

[0036] Concrete 2#: In parts by mass, 440 parts of modified shale ceramsite #2, 480 parts of cement, and 600 parts of fine aggregate were stirred in a mixer for 15 seconds. Then, 4 parts of water reducer, 0.6 parts of air entraining agent, and 200 parts of water were poured into the mixer and stirred evenly for 2 minutes. The concrete was placed into a test mold (a concrete prism specimen of 100 mm × 100 mm × 300 mm) that had been brushed with lubricating oil in advance using a trowel, and internal bubbles were eliminated using a vibrator. The concrete was removed from the mold after standing for 24 hours, and standard curing was performed for 28 days.

[0037] Concrete 3#: In parts by mass, 492 parts of modified shale ceramsite #3, 500 parts of cement, and 608 parts of fine aggregate were stirred in a mixer for 15 seconds. Then, 5.27 parts of water reducer, 0.73 parts of air entraining agent, and 184 parts of water were poured into the mixer and stirred evenly for 2 minutes. The concrete was placed into a test mold (a concrete prism specimen of 100 mm × 100 mm × 300 mm) that had been brushed with lubricating oil in advance using a trowel, and internal bubbles were eliminated using a vibrator. The concrete was removed from the mold after standing for 24 hours, and standard curing was performed for 28 days.

[0038] Concrete 4#: In parts by mass, 510 parts of modified shale ceramsite #4, 530 parts of cement, and 620 parts of fine aggregate were stirred in a mixer for 15 seconds. Then, 6 parts of water reducer, 1 part of air entraining agent, and 210 parts of water were poured into the mixer and stirred evenly for 2 minutes. The concrete was placed into a test mold (a concrete prism specimen of 100 mm × 100 mm × 300 mm) that had been brushed with lubricating oil in advance using a trowel, and internal bubbles were eliminated using a vibrator. The concrete was removed from the mold after standing for 24 hours, and standard curing was performed for 28 days.

[0039] Concrete 5#: In parts by mass, 510 parts of modified shale ceramsite #5, 530 parts of cement, and 620 parts of fine aggregate were stirred in a mixer for 15 seconds. Then, 6 parts of water reducer, 1 part of air entraining agent, and 210 parts of water were poured into the mixer and stirred evenly for 2 minutes. The concrete was placed with a trowel into a test mold (a concrete prism specimen of 100 mm × 100 mm × 300 mm) that had been brushed with lubricating oil in advance. A vibrator was used to eliminate internal bubbles. The concrete was removed from the mold after standing for 24 hours and then subjected to standard curing for 28 days.

[0040] Concrete 6#: In parts by mass, 510 parts of modified shale ceramsite #6, 530 parts of cement, and 620 parts of fine aggregate were stirred in a mixer for 15 seconds. Then, 6 parts of water reducer, 1 part of air entraining agent, and 210 parts of water were poured into the mixer and stirred evenly for 2 minutes. The concrete was placed into a test mold (a concrete prism specimen of 100 mm × 100 mm × 300 mm) that had been brushed with lubricating oil in advance using a trowel, and internal bubbles were eliminated using a vibrator. The concrete was removed from the mold after standing for 24 hours, and standard curing was performed for 28 days.

[0041] Concrete 7#: In parts by mass, 510 parts of shale ceramsite, 530 parts of cement, and 620 parts of fine aggregate are stirred in a mixer for 15 seconds. Then, 6 parts of water reducer, 1 part of air entraining agent, and 210 parts of water are poured into the mixer and stirred evenly for 2 minutes. Use a trowel to put the concrete into a test mold (a concrete prism specimen of 100mm×100mm×300mm) that has been brushed with lubricating oil in advance, and use a vibrator to eliminate internal bubbles. After standing for 24 hours, remove the mold and perform standard curing for 28 days.

[0042] (1) Axial compressive strength test:

[0043] Strength testing was performed using a WAW-600 universal testing machine. Before testing, the upper and lower contact surfaces of the press were wiped clean. The base was adjusted, the specimen was placed in the center of the base, and the press height was slowly adjusted. The loading rate was set to 3 MPa / s, in compliance with the "Standard for Test Methods of Mechanical Properties of Ordinary Concrete" (GB / T 50081-2002). To reduce errors caused by discreteness, three specimens were tested in each group, and the average axial compressive strength was taken. If the measured value exceeded the median by 15%, it was discarded and the median value was used for calculation. Since this test used non-standard specimens, a conversion factor of 0.95 should be applied in the calculation.

[0044] (2) Water absorption test:

[0045] Take the same mass of test sample and place it in a container, completely submerge it in water, and soak it for 3 days. The mass before immersion is m, the mass after immersion is M, and the water absorption rate is [(Mm) / m] × 100%.

[0046] (3) Anti-segregation performance test:

[0047] The degree of stratification is used to evaluate the segregation resistance of concrete mixtures. This test measures the difference in compressive strength between specimens molded from the upper and lower layers of a concrete mixture in a stratification bucket (the bucket is divided into three layers, each 100 mm high and 200 mm long) after 20 seconds of vibration. The difference in 28-day compressive strength of hand-molded specimens from the upper and lower layers of the concrete mixture in the stratification bucket is measured. Vibration is performed on a vibrating table with a frequency of 50 Hz and an amplitude of 0.5 mm. Segregation resistance is measured by the difference in compressive strength. The compressive strength of specimens molded from the upper and lower layers of the concrete mixture is f1, and the compressive strength of specimens molded from the lower layer is f2. The compressive strength difference is [2(f1-f2) / (f1+f2)]×100%.

[0048] The test results are shown in Table 1.

[0049] Table 1 Concrete performance test results

[0050]

[0051] As shown in Table 1, the present invention utilizes a 1-5 wt% ethyl cellulose solution and a 10-20 wt% phenolic resin solution to synergistically modify shale ceramsite, resulting in concrete exhibiting high compressive strength, low water absorption, low compressive strength differential, and high slump. While using an excessively high concentration of phenolic resin solution (Concrete 5#) improves the concrete's compressive strength, the resulting compressive strength differential is too large, easily leading to cracking and making it difficult to use. Using an excessively low concentration of ethyl cellulose and phenolic resin solution (Concrete 6#) yields less significant improvements, achieving results similar to those achieved by using shale ceramsite directly.

[0052] As described above, the basic principles, main features and advantages of the present invention are well described. The above embodiments and descriptions are merely descriptions of preferred embodiments of the present invention, and the present invention is not limited to the above embodiments. Various changes and improvements made to the technical solutions of the present invention by those skilled in the art without departing from the spirit and scope of the present invention should fall within the scope of protection determined by the present invention.

Claims

1. A method for preparing concrete based on modified shale ceramsite, characterized in that: include: The modified shale ceramsite is prepared by immersing the shale ceramsite in a 1-5 wt% ethyl cellulose solution, curing the ceramsite at 160-180°C, mixing the shale ceramsite with a 10-20 wt% phenolic resin solution, and curing the ceramsite at 140-160°C after the solvent is completely evaporated. The modified shale ceramsite, cement and fine aggregate are mixed evenly, and then water, a water reducing agent and an air entraining agent are added, and the mixture is stirred thoroughly to obtain the concrete; Every 50g of shale ceramsite is mixed with 30-60mL of the phenolic resin solution; The raw materials of the concrete include, by mass: 470-510 parts of modified shale ceramsite, 450-530 parts of cement, 580-620 parts of fine aggregate, 3-6 parts of water reducer, 0.5-1 part of air entraining agent, and 180-210 parts of water; The curing time after the shale ceramsite is immersed in the ethyl cellulose solution and taken out is 1.5 to 3 hours, and the curing time after the solvent is completely volatilized and taken out is 4 to 8 hours.

2. The method for preparing concrete based on modified shale ceramsite according to claim 1, characterized in that: The raw materials of the concrete include, by mass, 492 parts of modified shale ceramsite, 500 parts of cement, 608 parts of fine aggregate, 5.27 parts of water reducer, 0.73 parts of air entraining agent, and 184 parts of water.

3. The method for preparing concrete based on modified shale ceramsite according to claim 1, characterized in that: The fine aggregate is a mixture of natural sand and artificial sand, and the fineness modulus is 2.

65.

4. The method for preparing concrete based on modified shale ceramsite according to claim 1, characterized in that: The solvent of the ethyl cellulose solution or the phenolic resin solution is independently selected from at least one of chloroform, ethanol or methanol.

5. The method for preparing concrete based on modified shale ceramsite according to claim 1, characterized in that: The particle size of the shale ceramsite is not greater than 16 mm.

6. A concrete based on modified shale ceramsite, characterized in that: The concrete is prepared by the method for preparing the modified shale ceramsite according to any one of claims 1 to 5.

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