Lightweight high-strength concrete material and method for producing the same

Abstract

The application provides a lightweight high-strength concrete material and a preparation method thereof. The application comprises the following steps: taking cement, silica fume, saw mud, fly ash floating beads, hollow glass microbeads, fly ash coarse ash and ceramsite according to preset weight proportions, mixing the cement, the silica fume, the saw mud, the fly ash floating beads, the hollow glass microbeads, the fly ash coarse ash and the ceramsite, adding a predetermined amount of water, fully mixing to obtain a raw material mixture; adding the remaining water and a predetermined amount of a water reducing agent into the raw material mixture, uniformly stirring to obtain a concrete slurry; and shaping and curing the concrete slurry to obtain the lightweight high-strength concrete material. Through the above method, the application can not only compensate for the shortcomings of traditional lightweight aggregates, such as low strength, high water absorption and easy stratification, but also fully improve the compactness, homogeneity and mechanical properties of the concrete, so that higher strength can be achieved under the premise of reducing the concrete bulk density, so that the lightweight high-strength concrete material prepared has low bulk density and high strength, and the unity of lightweight and high strength of the cement-based material is achieved.

Description

Technical Field

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

[0002] With the advancement of science and technology and the demands of economic and social development, the drawback of ordinary concrete, whose deadweight accounts for a large proportion of the total building load, has become more prominent. The demand for lightweight, high-strength materials in the engineering field has become increasingly apparent. Lightweight, high-strength concrete is one of the current hot development directions in concrete technology. It has the advantages of high strength, light weight, good durability, good volume stability, and excellent thermal insulation properties. It has broad application prospects in super high-rise buildings, long-span structures, bridge engineering, marine engineering and other fields.

[0003] Currently, the quality of traditional lightweight aggregates is generally low, limiting the strength and bulk density of the lightweight, high-strength concrete they produce. When it comes to creating lightweight, high-strength materials with even lower bulk densities, the strength drops significantly, making it difficult to meet the required standards. Therefore, balancing strength with low bulk density—ensuring sufficient strength while minimizing bulk density—is a top priority for lightweight, high-strength materials.

[0004] Patent publication number CN115557801A provides a lightweight, high-strength, low-shrinkage concrete and its preparation method. The lightweight concrete is prepared using glass microspheres, coarse lightweight aggregate, and discarded hard plastic particles. The close-packing theory is employed to prepare a high-strength concrete system of cement, mineral admixtures, quartz sand, and glass microspheres. An optimized construction process is then used to produce the lightweight, high-strength, low-shrinkage concrete. However, to ensure high strength, the concrete produced by this method has a relatively high bulk density, which limits its application. Achieving a low bulk density while maintaining high strength remains a pressing issue.

[0005] In view of this, it is necessary to design an improved lightweight high-strength concrete material and a preparation method thereof to solve the above problems. Summary of the Invention

[0006] In response to the shortcomings of the above-mentioned prior art, the present invention aims to provide a lightweight, high-strength concrete material with low bulk density and high strength, and a method for preparing the same. This invention utilizes hollow glass microspheres of specific particle sizes, fly ash floating beads, and fly ash coarse ash in specific proportions to reduce the bulk density of the slurry while maintaining its strength. This material, in combination with ceramsite, improves the homogeneity of the concrete. Furthermore, sawdust, a solid waste from cutting and polishing natural stone, is added as a filler to improve the compactness of the concrete structure. The resulting lightweight, high-strength concrete material achieves the desired balance of lightness and high strength expected of cement-based materials.

[0007] To achieve the above object, the present invention provides a method for preparing a lightweight high-strength concrete material, comprising the following steps:

[0008] S1. Weigh cement, silica fume, sawdust, fly ash beads, hollow glass microspheres, fly ash coarse ash, and ceramsite according to preset weight proportions, mix them, add a predetermined amount of water, and mix thoroughly to obtain a raw material mixture;

[0009] S2. Add the remaining water and a predetermined amount of water reducing agent to the raw material mixture obtained in step S1, and stir evenly to obtain concrete slurry;

[0010] S3. The concrete slurry obtained in step S2 is molded and cured to obtain a lightweight and high-strength concrete material.

[0011] As a further improvement of the present invention, the weight proportions of the raw materials in the lightweight high-strength concrete material are as follows:

[0012] Cement, 15-25 parts;

[0013] Silica fume, 5-10 parts;

[0014] Sawdust, 5-8 parts;

[0015] Fly ash beads, 5-10 parts;

[0016] Hollow glass microspheres, 2-4 parts;

[0017] Fly ash coarse ash, 8-12 parts;

[0018] Ceramsite, 30-40 parts;

[0019] Water reducing agent, 1 to 2 parts;

[0020] Water, 6-10 parts.

[0021] As a further improvement of the present invention, the apparent density of the hollow glass microspheres is 350 to 450 kg / m 3 , particle size is 150 ~ 200μm; the fly ash coarse ash particle size greater than 45μm particles account for 70%, the apparent density is 1800 ~ 2000kg / m 3 The fly ash floating beads are light floating beads separated from fly ash in power plants, with a particle size of 20 to 40 mesh and an apparent density of 500 to 520 kg / m 3 .

[0022] As a further improvement of the present invention, the ceramsite is shale ceramsite with an apparent density of 1300-1400 kg / m 3 .

[0023] As a further improvement of the present invention, the saw mud is the original wet saw mud produced by granite cutting, with a moisture content of 10% to 30%, and the specific surface area of ​​the saw mud after drying is 620 to 700 m 2 / kg.

[0024] As a further improvement of the present invention, the cement is ordinary Portland cement with a strength of ≥52.5 MPa.

[0025] As a further improvement of the present invention, the specific surface area of ​​the silica fume is ≥15000m 2 / kg, the SiO2 content in the silica ash is greater than 92% to 95%.

[0026] As a further improvement of the present invention, in step S1, the added water accounts for 70% to 85% of the total water; the water reducer is a polycarboxylic acid water reducer powder, and the water reduction rate is 35% to 40%.

[0027] As a further improvement of the present invention, in step S3, the curing method is curing under standard conditions for 28 days or curing in 70°C water for 5 days.

[0028] To achieve the above objectives, the present invention further provides a lightweight high-strength concrete material, which is prepared according to the method described in any of the above technical solutions.

[0029] The bulk density of the lightweight high-strength concrete is 1250-1400 kg / m 3 , the compressive strength is 55~70MPa.

[0030] The beneficial effects of the present invention are:

[0031] 1. The preparation method of the lightweight high-strength concrete material provided by the present invention, by using hollow glass microspheres as high-strength lightweight powder, the strength of the slurry is ensured while the bulk density of the slurry is greatly reduced, and on this basis, fly ash floating beads and coarse fly ash are used together as lightweight concrete fine aggregate, which can not only make up for the shortcomings of low strength and high water absorption of traditional lightweight aggregate, but also can further achieve higher strength under the premise of reducing the bulk density of concrete slurry, and stimulate its pozzolanic effect under the action of calcium hydroxide produced by cement hydration, enhance the interfacial bonding strength between the cementitious material matrix and the aggregate, and fully improve the mechanical properties of concrete. At the same time, the present invention uses hollow glass microspheres, fly ash floating beads and fly ash coarse ash of specific particle size and ratio to reduce the wet density of concrete slurry to a degree comparable to that of lightweight coarse aggregate ceramsite and slightly lower than the density of ceramsite. At this time, after adding ceramsite, the floating phenomenon of ceramsite under vibration conditions can be stopped, thereby greatly improving the overall homogeneity of lightweight concrete, which is beneficial to the improvement of its strength. In addition, fly ash coarse ash is a bulk solid waste. Using it in lightweight and high-strength concrete can also increase its added value and has important economic and environmental benefits.

[0032] 2. The method for preparing lightweight, high-strength concrete materials provided by the present invention introduces original sawdust with a high water content as a raw material for preparing concrete. The ultrafine powder in the sawdust can fully fill the gaps between cement and silica fume, effectively enhancing the density of the lightweight, high-strength concrete structure and improving the strength of the resulting lightweight concrete. At the same time, the sawdust powder is mainly composed of siliceous materials, which can be further hydrated in high-strength concrete to form hydrated calcium silicate, further improving the strength of the concrete. In addition, this type of original sawdust is a solid waste generated during the cutting and polishing process of natural stone. Due to its high water content and sticky texture, conventional processing is very difficult. The present invention applies it in the preparation process of lightweight, high-strength concrete, which also improves the applicability of sawdust and has important guiding significance for the resource utilization of sawdust.

[0033] 3. The preparation method of the lightweight high-strength concrete material provided by the present invention can reduce the bulk density of the final concrete by using low-density raw materials by regulating the composition, particle size and dosage of each raw material. At the same time, the particle gradation between the raw materials is used to increase the bulk density, so that the concrete has higher density. The synergistic effect between the raw materials is used to improve the homogeneity and mechanical properties of the concrete. The bulk density of the final lightweight high-strength concrete is in the range of 1250-1400 kg / m 3The material boasts a compressive strength of 58-70 MPa, a low bulk density, and high strength, achieving the ideal balance of lightweight and high strength for cement-based materials. Furthermore, the raw materials for this lightweight, high-strength concrete can be directly mixed on-site with water, exhibiting excellent fluidity and self-compacting properties. This material is particularly suitable for use in prefabricated, cast-in-place lightweight floor slabs or lightweight, cast-in-place wall load-bearing structures, demonstrating promising application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 This is a diagram of the internal structure of the lightweight and high-strength concrete material prepared in Example 1. DETAILED DESCRIPTION

[0035] In order to make the objectives, technical solutions and advantages of the present invention more clear, the present invention is described in detail below with reference to the accompanying drawings and specific embodiments.

[0036] It should also be noted here that, in order to avoid obscuring the present invention due to unnecessary details, only structures and / or processing steps closely related to the solutions of the present invention are shown in the drawings, while other details that are not closely related to the present invention are omitted.

[0037] In addition, it should be noted that the terms "comprises", "includes" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article or apparatus that includes a series of elements includes not only those elements, but also includes other elements not explicitly listed, or also includes elements inherent to such process, method, article or apparatus.

[0038] The present invention provides a method for preparing a lightweight high-strength concrete material, comprising the following steps:

[0039] S1. Weigh cement, silica fume, sawdust, fly ash beads, hollow glass microspheres, fly ash coarse ash, and ceramsite according to preset weight proportions, mix them, add a predetermined amount of water, and mix thoroughly to obtain a raw material mixture;

[0040] S2. Add the remaining water and a predetermined amount of water reducing agent to the raw material mixture obtained in step S1, and stir evenly to obtain concrete slurry;

[0041] S3. The concrete slurry obtained in step S2 is molded and cured to obtain a lightweight and high-strength concrete material.

[0042] In the lightweight high-strength concrete material, the weight proportions of the various raw materials are as follows:

[0043] Cement, 15-25 parts;

[0044] Silica fume, 5-10 parts;

[0045] Sawdust, 5-8 parts;

[0046] Fly ash beads, 5-10 parts;

[0047] Hollow glass microspheres, 2-4 parts;

[0048] Fly ash coarse ash, 8-12 parts;

[0049] Ceramsite, 30-40 parts;

[0050] Water reducing agent, 1 to 2 parts;

[0051] Water, 6-10 parts.

[0052] The apparent density of the hollow glass microspheres is 350-450 kg / m 3 , particle size is 150 ~ 200μm; the fly ash coarse ash particle size greater than 45μm particles account for 70%, the apparent density is 1800 ~ 2000kg / m 3 The fly ash floating beads are light floating beads separated from fly ash in power plants, with a particle size of 20 to 40 mesh and an apparent density of 500 to 520 kg / m 3 . With such an arrangement, hollow glass microspheres, as high-strength and lightweight powders, can ensure the strength of the slurry while significantly reducing the bulk density of the slurry. On this basis, fly ash floating beads and coarse fly ash are used together as fine aggregates for lightweight concrete. This can not only make up for the shortcomings of low strength and high water absorption of traditional lightweight aggregates, but also further achieve higher strength while reducing the bulk density of the concrete slurry. Under the action of calcium hydroxide produced by cement hydration, the volcanic ash effect is stimulated, the interfacial bonding strength between the cementitious material matrix and the aggregate is enhanced, and the mechanical properties of the concrete are fully improved. Moreover, based on the synergistic effect of hollow glass microspheres, coarse fly ash and fly ash floating beads, the amount of hollow glass microspheres added, which are more expensive, can be effectively reduced, and the unity of low bulk density and high strength can be achieved while reducing costs.

[0053] The ceramsite is shale ceramsite with an apparent density of 1300-1400 kg / m 3 The present invention uses hollow glass microspheres, fly ash floating beads and fly ash coarse ash of specific particle sizes and proportions to reduce the wet density of the concrete slurry to a level equivalent to the density of ceramsite as a lightweight coarse aggregate and slightly lower than the aggregate density. With this arrangement, after the ceramsite is added, the floating phenomenon of the ceramsite under vibration conditions can be eliminated, effectively solving the problem of easy stratification of traditional lightweight aggregates, greatly improving the overall homogeneity of the lightweight concrete, and facilitating the improvement of its strength.

[0054] The cement is ordinary Portland cement with a strength of ≥52.5MPa; the specific surface area of ​​the silica fume is ≥15000m 2 / kg, the SiO2 content in the silica fume is greater than 92% to 95%; the saw mud is the original wet saw mud produced by granite cutting, with a moisture content of 10% to 30%, and the specific surface area of ​​the saw mud after drying is 620 to 700m 2 This arrangement allows the ultrafine powder in sawdust to fully fill the gaps between cement and silica fume, effectively enhancing the density of lightweight, high-strength concrete structures and improving the strength of the resulting lightweight concrete. Furthermore, sawdust powder, primarily composed of siliceous materials, further hydrates in high-strength concrete to form hydrated calcium silicate, further increasing the concrete's strength.

[0055] In step S1, the added water accounts for 70% to 85% of the total water volume; the water reducer is a polycarboxylic acid water reducer powder, and the water reduction rate is 35% to 40%.

[0056] In step S3, the curing method is curing under standard conditions for 28 days or curing in 70°C water for 5 days.

[0057] The present invention also provides a lightweight high-strength concrete material, which is prepared according to the method described in any of the above technical solutions; the bulk density of the lightweight high-strength concrete is 1250-1400 kg / m 3 , the compressive strength is 58~70MPa.

[0058] The lightweight high-strength concrete material and the preparation method thereof provided by the present invention are described in detail below with reference to specific embodiments and comparative examples.

[0059] Example 1

[0060] This embodiment provides a lightweight high-strength concrete material, which includes the following components in parts by weight:

[0061] cement, 21 parts;

[0062] Silica fume, 7.5 parts;

[0063] Sawdust, 6 parts;

[0064] Fly ash beads, 7.5 parts;

[0065] hollow glass microspheres, 2.5 parts;

[0066] fly ash coarse ash, 10 parts;

[0067] ceramsite, 36 parts;

[0068] Water reducing agent, 1.5 parts;

[0069] Water, 8 parts.

[0070] Among them, the sources and performance parameters of each raw material are as follows:

[0071] Cement: P.O 52.5 Portland cement produced by Wuhan Huaxin Cement Co., Ltd., apparent density 3140 kg / m 3 3 ; silica fume: semi-encrypted silica fume, apparent density 2200 kg / m 2 , SiO2 content 94%, specific surface area 18000 m 2 / kg; saw mud: tailings of Ma City granite cutting, water content 19.3%, after drying, the powder with particle size less than 45 μm accounts for 88%, specific surface area (powder below 45 μm) 660 m 3 / kg, apparent density 2620 kg / m 3 , powder flow ratio 102%; fly ash floating beads: fineness 20-40 mesh, apparent density 510 kg / m 3 ; hollow glass microspheres: apparent density 400 kg / m 3 , particle size 150-200 μm; fly ash raw ash: produced by Yanglu Power Plant, particles with particle size greater than 45 μm in fly ash coarse ash accounts for 70%, apparent density 1900 kg / m 3 , 28d activity index 60%; ceramsite: commercially available lightweight aggregate shale ceramsite, apparent density 1350 kg / m 3 .

[0072] The embodiment also provides a preparation method of the lightweight high-strength concrete, comprising the following steps:

[0073] S1, the cement, silica fume, saw mud, fly ash floating beads, hollow glass microspheres, fly ash coarse ash and ceramsite are weighed according to the above weight proportions, then mixed, 80% of the total water is added, stirred for 2 min, and uniformly mixed to obtain a raw material mixture;

[0074] S2, 20% of the total water and the polycarboxylic acid water reducer weighed according to the weight proportion are added to the raw material mixture obtained in step S1, and stirring is continued for 5 min, and a concrete slurry with good fluidity is obtained after uniform stirring (the slump of the slurry is measured to be 260 mm, and the spread is 710 mm);

[0075] S3, the concrete slurry obtained in step S2 is poured into a mold, bubbles are removed after vibration, and then shaped after standing, and then cured under standard conditions for 28 days to obtain a lightweight high-strength concrete material.

[0076] ​The properties of the lightweight high-strength concrete obtained in this example were tested. The wet bulk density and compressive strength of the lightweight high-strength concrete were measured in accordance with JGJ / T70-2009 "Standard for Test Methods for Basic Properties of Building Concrete". The results are shown in Table 1:

[0077] Table 1 Performance parameters of lightweight high-strength concrete materials prepared in Example 1

[0078] <![CDATA[容重(kg / m 3 )]]> Compressive strength (MPa) 1324 62.1

[0079] It can be seen from the above table that the lightweight high-strength concrete prepared in this embodiment has both low bulk density and high strength, achieving the unity of lightweight and high strength of cement-based materials.

[0080] The cross-sectional view of the lightweight high-strength concrete prepared in this embodiment is as follows: Figure 1 As shown by Figure 1 It can be seen that the concrete has good density and homogeneity.

[0081] Examples 2 to 11 and Comparative Examples 1 to 6

[0082] Examples 2 to 11 and comparative examples 1 to 6 respectively provide a method for preparing a lightweight high-strength concrete material. Compared with Example 1, the only difference is that the weight proportions of the raw materials are changed. The raw material proportions corresponding to each embodiment and comparative example are shown in Table 2. The remaining steps and parameters are the same as those in Example 1 and are not repeated here.

[0083] Table 2 Raw material ratios of Examples 2 to 13 and Comparative Examples 1 to 6 (unit: parts by weight)

[0084]

[0085] The bulk density and 28d compressive strength of the lightweight high-strength concrete materials prepared in the above embodiments and comparative examples were tested, and the results are shown in Table 3.

[0086] Table 3 Performance data of Examples 2 to 11 and Comparative Examples 1 to 6

[0087] Example / Comparative Example <![CDATA[容重(kg / m 3 )]]> Compressive strength (MPa) Example 2 1318 60.6 Example 3 1337 61.4 Example 4 1369 67.7 Example 5 1277 58.3 Example 6 1354 63.5 Example 7 1290 58.1 Example 8 1315 59.3 Example 9 1332 60.3 Example 10 1319 63.4 Example 11 1327 60.7 Comparative Example 1 1295 54.3 Comparative Example 2 1536 63.9 Comparative Example 3 1410 60.8 Comparative Example 4 1282 52.5 Comparative Example 5 1329 57.6 Comparative Example 6 1334 51.9

[0088] It can be seen from Table 3 that the change of raw material composition has an important influence on the bulk density and compressive strength of the prepared concrete.

[0089] More specifically, a comparison of Examples 1-3 and Comparative Example 1 shows that the amount of sawdust used has a relatively significant impact on concrete strength, with either too much or too little leading to reduced strength in the resulting concrete. This is primarily because the sawdust in the present invention primarily serves as a filler, and too little of it makes it difficult to achieve effective filling, resulting in more voids between the cement and silica fume, leading to reduced strength. However, sawdust itself is not highly active, and if too much sawdust is added, the proportion of the more active cement and silica fume decreases, further reducing strength. Therefore, by adjusting the sawdust dosage to a specific ratio, optimal strength can be achieved.

[0090] By comparing Example 1, Examples 4 to 9, and Comparative Examples 2 to 4, it can be seen that the addition of fly ash floating beads and hollow glass microspheres is beneficial to effectively reduce the bulk density, but will lead to a decrease in strength, while the change in the amount of fly ash coarse ash has little effect on the bulk density, and too much or too little fly ash coarse ash will lead to a decrease in the strength of the concrete. However, if any of the fly ash floating beads, hollow glass microspheres, and fly ash coarse ash are not added at all, not only will the final bulk density be affected by the change in raw material density, but the concrete strength will also be reduced due to the impact on the particle grading effect and the homogeneity of the concrete. Therefore, fly ash floating beads, hollow glass microspheres, and fly ash coarse ash are indispensable, and the amount of each raw material needs to be controlled within a specific range.

[0091] By comparing Example 1, Examples 10 to 11 and Comparative Examples 5 to 6, it can be seen that the change in the amount of ceramsite has little effect on the bulk density. This is mainly because the present invention regulates the ratio of other raw materials to make the concrete slurry have a density similar to that of ceramsite. On this basis, the amount of ceramsite is adjusted, which basically does not affect the bulk density of the prepared concrete, but mainly affects the strength of the concrete. In addition, too much or too little ceramsite is not conducive to improving the strength of the concrete.

[0092] Therefore, the present invention can ensure that the bulk density of the prepared concrete is between 1250 and 1400 kg / m by controlling the amount of each raw material within a specific range. 3 At the same time, its compressive strength can still reach 58-70MPa, and it has lower bulk density and higher strength, so as to achieve the unity of light weight and high strength of cement-based materials.

[0093] Comparative Examples 7-8

[0094] Comparative Examples 7 and 8 provide a method for preparing a lightweight high-strength concrete material. Compared with Example 1, Comparative Example 7 changes the specifications of the hollow glass microspheres used, and selects an apparent density of 500 kg / m 3 , hollow glass microspheres with a particle size range of 50 to 100 μm; Comparative Example 8 is to replace the fly ash coarse ash and fly ash floating beads with conventional fly ash (apparent density of 2700 kg / m3 , particle size <45 μm), and the remaining raw materials and their weight proportions are the same as those in Example 1 and will not be repeated here.

[0095] The bulk density and 28d compressive strength of the lightweight high-strength concrete material prepared in the above comparative example were tested, and the results are shown in Table 4.

[0096] Table 4 Performance data of comparative examples 7 to 8

[0097]

[0098]

[0099] As can be seen in Table 4, the particle size of the raw materials has a significant impact on the bulk density and compressive strength of the resulting lightweight, high-strength concrete. Even under the same composition, changes in the particle size of the raw materials can affect the overall density and the gradation between the raw materials, thereby affecting the bulk density and compressive strength of the lightweight, high-strength concrete. By selecting hollow glass microspheres, fly ash coarse ash, and fly ash floating beads of specific sizes, the present invention can simultaneously reduce the bulk density and improve the overall gradation, resulting in a low bulk density and high strength, achieving the goal of combining lightweight and high strength in cement-based materials.

[0100] In summary, the present invention provides a lightweight and high-strength concrete material and a preparation method thereof. The present invention weighs cement, silica fume, sawdust, fly ash floating beads, hollow glass microspheres, fly ash coarse ash, and ceramsite according to preset weight proportions and mixes them, then adds a predetermined amount of water and mixes them thoroughly to obtain a raw material mixture; adds the remaining water and a predetermined amount of water reducer to the raw material mixture, stirs evenly to obtain a concrete slurry; and forms and cures the concrete slurry to obtain a lightweight and high-strength concrete material. In the above manner, the present invention can not only make up for the shortcomings of traditional lightweight aggregates such as low strength, high water absorption, and easy stratification, but also fully improve the density, homogeneity, and mechanical properties of concrete, and can achieve higher strength while reducing the bulk density of concrete, so that the obtained lightweight and high-strength concrete material has both low bulk density and high strength, realizing the unity of lightness and high strength of cement-based materials.

[0101] The above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, it should be understood by those skilled in the art that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present invention.

Claims

1. A method for preparing a lightweight high-strength concrete material, characterized in that: Includes the following steps S1. Weigh cement, silica fume, sawdust, fly ash floating beads, hollow glass microspheres, fly ash coarse ash, and ceramsite according to preset weight proportions and mix them, then add a predetermined amount of water and mix thoroughly to obtain a raw material mixture; the apparent density of the hollow glass microspheres is 350-450 kg / m 3 , with a particle size of 150~200μm; the particles with a particle size greater than 45μm account for 70% of the coarse fly ash, and the apparent density is 1800~2000kg / m 3 The fly ash floating beads are light floating beads selected from fly ash of power plants, with a particle size of 20~40 mesh and an apparent density of 500~520 kg / m 3 The apparent density of the ceramsite is 1300-1400 kg / m 3 ; S2. Add the remaining water and a predetermined amount of water reducing agent to the raw material mixture obtained in step S1, and stir evenly to obtain concrete slurry; S3, forming and curing the concrete slurry obtained in step S2 to obtain a lightweight high-strength concrete material; the bulk density of the lightweight high-strength concrete is 1250~1400kg / m 3 ; In the lightweight high-strength concrete material, the weight proportions of the various raw materials are as follows: Cement, 15-25 parts; Silica fume, 5-10 parts; Sawdust, 5-8 parts; Fly ash beads, 5-10 parts; Hollow glass microspheres, 2-4 parts; Fly ash coarse ash, 8-12 parts; Ceramsite, 30-40 parts; Water reducing agent, 1~2 parts; Water, 6-10 parts.

2. The method for preparing a lightweight high-strength concrete material according to claim 1, characterized in that: The ceramsite is shale ceramsite.

3. The method for preparing a lightweight high-strength concrete material according to claim 1, wherein the saw mud is original wet saw mud produced by cutting granite, has a moisture content of 10% to 30%, and has a specific surface area of ​​620 to 700 m2 after drying. 2 / kg.

4. The method for preparing a lightweight high-strength concrete material according to claim 1, wherein the cement is ordinary Portland cement with a strength of ≥52.5 MPa.

5. The method for preparing a lightweight high-strength concrete material according to claim 1, wherein the specific surface area of ​​the silica fume is ≥ 15000 m 2 / kg, SiO2 content is greater than 92%~95%.

6. The method for preparing a lightweight high-strength concrete material according to claim 1, wherein in step S1, the added water accounts for 70% to 85% of the total water; the water reducer is a polycarboxylic acid water reducer powder, and the water reduction rate is 35% to 40%.

7. The method for preparing a lightweight high-strength concrete material according to claim 1, wherein in step S3, the curing method is curing for 28 days under standard conditions or curing in 70°C water for 5 days.

8. A lightweight high-strength concrete material, characterized in that: The product is prepared by the preparation method described in any one of claims 1 to 7.

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