Modified material for composite admixture, composite admixture and prepared concrete

Abstract

The invention relates to the technical field of solid waste treatment and building materials, in particular to a modified material for a waste stone composite admixture, the composite admixture and prepared concrete. The modified material for the composite admixture comprises the following components in parts by weight: 40-50 parts of diatomite, 30-40 parts of white carbon black, 20-30 parts of glass beads, 4-6 parts of magnesium aluminum silicate, 3-5 parts of a dispersing agent and 2-4 parts of an exciting agent. The diatomite, the white carbon black, the glass beads, the magnesium aluminum silicate, the dispersing agent and the exciting agent are compounded according to a certain proportion, so that the early activity, the flowability, the cohesiveness and the long-term strength increasing performance of the stone powder can be synergistically improved, and the comprehensive performance of a composite admixture prepared from high-dosage stone powder can be greatly improved; it is guaranteed that the concrete prepared from the stone powder has good construction workability, strength and durability, stone solid waste resources such as hole slag excavation are fully utilized, and the additional value is increased.

Description

Technical Field

[0001] The present invention relates to the technical fields of solid waste treatment and building materials, and particularly relates to a modification material for a composite admixture, the composite admixture, and the prepared concrete. Background Art

[0002] Mineral admixtures are an important and indispensable part of modern concrete. After being proportionally blended with cement, sand, stones, water, and admixtures and going through stages such as mixing, pouring, and curing and hardening, concrete is formed. The performance of mineral admixtures has a significant impact on the performance of concrete. The specific mechanism is that the admixtures affect the comprehensive performance of concrete through their activity, fine aggregate, morphology, and other action effects. Different types of admixtures have different degrees of exertion of action effects.

[0003] Mineral admixtures have gradually developed from the initial single and traditional material types such as fly ash and slag powder to single and new material types such as various metallurgical solid waste fine powders (steel slag powder, gold / tungsten / copper tailings powder) other than slag powder, and rock fine powders of different lithologies (limestone, granite, gneiss). And on this basis, mineral admixtures are gradually moving towards compounding on the basis of various single and new materials, that is, a new and composite material formed by mixing two or more of the above materials. And with the transfer of infrastructure projects to mountainous and plateau areas, it is becoming increasingly difficult to obtain traditional mineral admixtures such as fly ash and slag powder. The resource utilization of waste stones excavated in mountainous engineering construction is of great significance. Waste stones can be prepared into stone powder, which is one of the raw materials for mineral admixtures. However, limited by the activity of stone powder, existing composite admixtures cannot contain a large amount of stone powder or even cannot contain stone powder at all.

[0004] In order to improve the activity of stone powder, currently, mainly mechanical grinding is used to increase the fineness of stone powder, or chemical substances are used for modification to increase the activation energy on the surface of stone powder to improve the activity. However, the performance of stone powder after current modification treatment still has many deficiencies compared with fly ash or slag powder in terms of performance. Not only is the addition amount low, but also the performance of the concrete cannot be guaranteed after the admixture containing stone powder is used to prepare concrete.

[0005] In view of this, the present invention is particularly proposed. Summary of the Invention

[0006] An object of the present invention is to provide a modification material for a composite admixture, which can significantly improve the comprehensive performance of the composite admixture prepared with a large amount of stone powder.

[0007] Another object of the present invention is to provide a composite admixture, which is prepared by compounding a large amount of stone powder and a modification material, and can significantly improve the performance of concrete after the concrete is prepared.

[0008] Another object of the present invention is to provide a concrete comprising the above composite admixture.

[0009] To achieve the above object of the present invention, a first aspect of the present invention provides a modifying material for a composite admixture, comprising the following components by weight:

[0010] 40 - 50 parts of diatomaceous earth, 30 - 40 parts of white carbon black, 20 - 30 parts of glass microspheres, 4 - 6 parts of magnesium aluminum silicate, 3 - 5 parts of dispersant, and 2 - 4 parts of activator.

[0011] In a specific embodiment of the present invention, the dispersant is a naphthalene sulfonic acid formaldehyde condensate.

[0012] In a specific embodiment of the present invention, the activator is triisopropanolamine and / or ethylenediamine.

[0013] In a specific embodiment of the present invention, the mass ratio of the sum of the masses of the diatomaceous earth and the white carbon black to the mass of the glass microspheres is (3 - 3.5):1.

[0014] In a specific embodiment of the present invention, the mass ratio of the sum of the masses of the diatomaceous earth and the white carbon black to the mass of the magnesium aluminum silicate is (15 - 20):1.

[0015] The present invention also provides a preparation method for the modifying material for a composite admixture according to the first aspect, comprising the following steps:

[0016] Mix the components in proportion to obtain a dry mixture; mix the dry mixture with water at a mass ratio of 100:(2 - 5) evenly to obtain a wet mixture; press the wet mixture into a shape to obtain the modifying material for a composite admixture.

[0017] A second aspect of the present invention provides a composite admixture, comprising stone powder and any one of the modifying materials for a composite admixture provided by the first aspect of the present invention.

[0018] In a specific embodiment of the present invention, in the composite admixture, the mass ratio of the stone powder to the modifying material for a composite admixture is (2 - 9):1.

[0019] In a specific embodiment of the present invention, the stone powder is made from tunnel slag stone powder. Further, the stone powder is at least one of gneiss stone powder and limestone powder. For example, the stone powder is microcrystalline limestone powder.

[0020] In a specific embodiment of the present invention, the fineness of the composite admixture is 325 mesh ± 25 mesh.

[0021] The present invention also provides a method for preparing the composite admixture in the second aspect, comprising the following steps: mixing stone powder with the modifying material for the composite admixture in a proportion and then performing grinding treatment.

[0022] In the third aspect of the present invention, a concrete is provided, which comprises any one of the composite admixtures provided in the second aspect of the present invention.

[0023] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0024] (1) The modifying material obtained by compounding diatomite, silica white, glass microspheres, magnesium aluminum silicate, dispersant and activator in a certain proportion in the present invention can synergistically improve the early activity, fluidity, cohesiveness and long-term strength growth performance of stone powder, can greatly improve the comprehensive performance of the composite admixture prepared with a large amount of stone powder, ensure that the concrete prepared with stone powder has good workability, strength and durability during construction, is beneficial to making full use of stone waste resources such as tunnel slag excavation, and improves the added value;

[0025] (2) The concrete prepared with the composite admixture of the present invention not only has excellent workability during construction, but also can significantly improve the strength and durability of the concrete. Specific Embodiments

[0026] The technical solutions of the present invention will be clearly and completely described below in conjunction with specific embodiments. However, those skilled in the art will understand that the following described embodiments are some embodiments of the present invention, rather than all embodiments, and are only used to illustrate the present invention and should not be construed as limiting the scope of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative efforts fall within the scope of protection of the present invention. For those conditions not specified in the embodiments, they are carried out according to conventional conditions or conditions recommended by the manufacturer. For the reagents or instruments not specified by the manufacturer, they are all conventional products that can be obtained through commercial purchase.

[0027] During the infrastructure construction process, a large amount of tunnel muck is generated during tunnel excavation. This type of tunnel muck faces problems such as high treatment costs, low degree of resource utilization, and potential risks in existing treatment technologies. Currently, the modification of the stone powder obtained from tunnel muck is relatively single, only focusing on one index, the activity index, and its fluidity, cohesiveness, long-term activity, etc. have not been improved, resulting in many deficiencies in the performance of the stone powder after the current modification treatment compared to fly ash or slag powder. Based on this, the present invention proposes a method for utilizing tunnel muck solid waste with high added value and high resource utilization rate, develops a modification material suitable for the stone powder obtained from tunnel muck, and compound the modification material with the stone powder obtained from tunnel muck to form a composite admixture. This composite admixture can not only significantly increase the dosage of stone powder, but also effectively improve the workability, strength, and durability of the concrete prepared with it as an admixture.

[0028] Based on this, in the first aspect of the present invention, there is provided a modification material for a composite admixture, comprising the following components in parts by weight: 40-50 parts of diatomite, 30-40 parts of white carbon black, 20-30 parts of glass microspheres, 4-6 parts of magnesium aluminum silicate, 3-5 parts of a dispersant, and 2-4 parts of an activator.

[0029] The present invention uses diatomite, white carbon black, glass microspheres, magnesium aluminum silicate, a dispersant, and an activator, and compound them in a certain proportion, which can synergistically improve the early activity, fluidity, cohesiveness, and long-term strength growth performance of the stone powder from aspects such as surface chemical modification and promotion of hydration reaction, can greatly improve the comprehensive performance of the composite admixture prepared with a large dosage of stone powder, and ensure that the concrete prepared with the stone powder has good workability, strength, and durability.

[0030] The addition of diatomite and white carbon black in the present invention can, on the one hand, improve the early activity of the stone powder in the admixture. The active components in diatomite and white carbon black can react with cement to form a gelling substance, increase the hydration rate, and thus improve the early strength of the concrete. At the same time, the compounding of glass microspheres and magnesium aluminum silicate ensures that the admixture has a certain fluidity and cohesiveness, improves the uniformity of hydration products, and ensures the workability of the concrete. The appropriate introduction of the dispersant, in combination with glass microspheres and magnesium aluminum silicate, makes the hydration products finer and more uniform, and fully exerts its strengthening effect on the concrete.

[0031] For example, in different embodiments, in the modification material for the composite admixture of the present invention, the dosages of each component in parts by weight can be as follows:

[0032] The dosage of diatomaceous earth can be 40 parts, 42 parts, 45 parts, 48 parts, 50 parts or the range composed of any two of them; the introduction of diatomaceous earth can, on the one hand, be filled in concrete to fill the gaps between sand particles and cement particles, improve the density of the concrete system, and then improve the strength, etc.; on the other hand, the active components in diatomaceous earth can react with cement to generate substances with hydraulic characteristics such as calcium silicate hydrate (C-S-H) and calcium aluminate hydrate (C-A-H). Combined with dispersants, etc., the hydration products are made finer and more uniform, which helps to further fill the capillary pores and enhance the strength of the concrete; when the dosage of diatomaceous earth is too low, it will lead to insufficient overall activity of the admixture, and then lead to low concrete strength and poor durability; when the dosage of diatomaceous earth is too high, not only the cost is too high, but also the particle size of the hydration products will increase, and the construction performance is not easy to control;

[0033] The dosage of silica white can be 30 parts, 32 parts, 35 parts, 38 parts, 40 parts or the range composed of any two of them; the introduction of silica white can also fill the gaps and improve the density; and it can react to generate calcium silicate hydrate (C-S-H) gel to enhance the strength; in addition, the introduction of an appropriate amount of silica white helps to improve the fluidity of the admixture, etc.; when the dosage of silica white is too high, on the one hand, the cost is too high, and on the other hand, it is easy to cause the concrete to be not easy to form;

[0034] The dosage of glass microspheres can be 20 parts, 22 parts, 25 parts, 28 parts, 30 parts or the range composed of any two of them; among them, the glass microspheres are hollow glass microspheres; the introduction of an appropriate amount of glass microspheres in the modified material of the present invention is beneficial to improving the overall fluidity of the composite admixture to ensure the uniform dispersion of each substance in the concrete slurry and is beneficial to improving the uniformity and fineness of the hydration products generated during the hydration process to fully exert the strengthening effect of the hydration products;

[0035] The dosage of magnesium aluminum silicate can be 4 parts, 4.5 parts, 5 parts, 5.5 parts, 6 parts or the range composed of any two of them; the magnesium aluminum silicate in the modified material of the present invention has a thickening effect to ensure the formability of the concrete structure and avoid segregation;

[0036] The dosage of the dispersant can be 3 parts, 3.5 parts, 4 parts, 4.5 parts, 5 parts or the range composed of any two of them; the addition of an appropriate amount of dispersant can improve the overall fluidity of the system after the composite admixture is used in concrete, and at the same time helps to obtain finer and more uniform hydration products;

[0037] The dosage of the activator can be 2 parts, 2.5 parts, 3 parts, 3.5 parts, 4 parts or the range composed of any two of them; the introduction of an appropriate amount of activator helps the composite admixture to better participate in the reaction of concrete and improve the overall strength and durability of the concrete, etc.

[0038] In a specific embodiment of the present invention, the dispersant is a naphthalene sulfonic acid formaldehyde condensate. Further research in the present invention has found that when using a naphthalene sulfonic acid formaldehyde condensate as a dispersant for modifying the stone powder admixture, it is more helpful to improve the fluidity of the stone powder and uniformly refine the hydration products obtained during the hydration process, and thus is more conducive to improving the strength of the concrete.

[0039] In a specific embodiment of the present invention, the activator is triisopropanolamine and / or ethylenediamine. Further research in the present invention has found that introducing triisopropanolamine into the modified material results in a composite admixture that is beneficial to improving the early strength of the concrete and can also promote the stable growth of the later strength of the concrete.

[0040] In a specific embodiment of the present invention, the mass ratio of the sum of the masses of diatomaceous earth and silica white to the mass of glass microspheres is (3 - 3.5):1, for example, it can be 3:1, 3.1:1, 3.2:1, 3.3:1, 3.4:1, 3.5:1 or the range composed of any two of them. Research has found that in the modified material of the present invention, the introduction of diatomaceous earth and silica white is mainly used to improve the activity of the composite admixture, and at the same time, glass microspheres are used to improve the overall fluidity of the composite admixture. When the mass ratio of the sum of the masses of diatomaceous earth and silica white to the mass of glass microspheres meets the above conditions, it is more conducive to improving the balance between the activity and fluidity of the large-volume stone powder admixture.

[0041] In a specific embodiment of the present invention, the mass ratio of the sum of the masses of diatomaceous earth and silica white to the mass of magnesium aluminum silicate is (15 - 20):1, for example, it can be 15:1, 16:1, 17:1, 18:1, 19:1, 20:1 or the range composed of any two of them. In the modified material of the present invention, the introduction of magnesium aluminum silicate can improve the viscosity of the composite admixture and improve the interfacial adhesion. When the dosage of magnesium aluminum silicate is adjusted to meet the above requirements, it is more conducive to improving the cohesiveness of the composite admixture and taking into account ensuring the uniform distribution and fineness of the hydration products, and avoiding problems such as poor uniformity caused by excessive agglomeration.

[0042] In a specific embodiment of the present invention, the particle size of the glass microspheres is 25 - 45 μm.

[0043] In a specific embodiment of the present invention, the particle size of the diatomaceous earth is 15 - 40 μm.

[0044] In a specific embodiment of the present invention, the particle size of the silica white is 10 - 100 nm.

[0045] In a specific embodiment of the present invention, the particle size of the magnesium aluminum silicate is 150 - 400 μm.

[0046] The present invention also provides a preparation method for the modified material for the composite admixture of the first aspect, including the following steps:

[0047] Mix each component proportionally to obtain a dry mixture; mix the dry mixture with water at a mass ratio of 100:(2 - 5) evenly to obtain a wet mixture; press the wet mixture into shape to obtain a modified material for composite admixture.

[0048] In different embodiments, the mass ratio of the dry mixture to water can be 100:2, 100:3, 100:4, 100:5 or the range composed of any two of them. In actual operation, the pressing into shape can be carried out by a rolling ball machine or a briquetting machine to obtain a modified material in the form of a sphere. Further, the particle size of the sphere can be 15 - 50 mm, for example, it can be 15 mm, 20 mm, 30 mm, 40 mm, 50 mm or the range composed of any two of them.

[0049] The second aspect of the present invention provides a composite admixture, which includes stone powder and any one of the modified materials for composite admixture provided in the first aspect of the present invention.

[0050] In the specific embodiments of the present invention, in the composite admixture, the mass ratio of the stone powder to the modified material for composite admixture is (2 - 9):1, for example, it can be 2:1, 4:1, 6:1, 8:1, 9:1 or the range composed of any two of them.

[0051] In the specific embodiments of the present invention, in the composite admixture, the mass proportion of the stone powder is 70% - 90%. The modified material of the present invention can improve the performance of concrete in all aspects while significantly increasing the dosage of stone powder in the composite admixture.

[0052] In the specific embodiments of the present invention, the stone powder is prepared from tunnel slag stone powder. Further, it is at least one of gneiss stone powder and limestone powder. For example, the stone powder used in the specific embodiments of the present invention is microcrystalline limestone powder.

[0053] In the specific embodiments of the present invention, the fineness of the composite admixture is 325 mesh ± 25 mesh. When the fineness of the composite admixture is regulated within the above range, it is more conducive to giving full play to the activity of the composite admixture and ensuring appropriate viscosity and fluidity. When the fineness is too fine, although the activity is significantly increased, it is too viscous, the fluidity becomes poor, and the uniformity becomes poor; when the fineness is too coarse, the activity is low.

[0054] The present invention also provides a preparation method of the composite admixture in the second aspect, which includes the following steps: mix the stone powder and the modified material for composite admixture proportionally and then carry out grinding treatment until the fineness reaches 325 mesh ± 25 mesh.

[0055] The third aspect of the present invention provides a kind of concrete, which includes any one of the composite admixtures provided in the third aspect of the present invention.

[0056] In a specific embodiment of the present invention, the concrete comprises the following components by weight: 260 - 320 parts of cement, 40 - 100 parts of composite admixture, 830 - 890 parts of sand, 1050 - 1110 parts of gravel, 140 - 160 parts of water, and 3 - 4 parts of liquid admixture.

[0057] Example 1

[0058] This example provides a modifying material for composite admixture, which comprises the following components by weight: 45 parts of diatomite, 35 parts of silica white, 25 parts of hollow glass microspheres, 5 parts of magnesium aluminum silicate, 4 parts of naphthalene sulfonic acid formaldehyde condensate, and 3 parts of triisopropanolamine.

[0059] Among them, the average particle size of the hollow glass microspheres is 25 μm, the average particle size of the diatomite is 30 μm, the average particle size of the silica white is 50 nm, and the average particle size of the magnesium aluminum silicate is 200 μm.

[0060] The preparation method of the modifying material for composite admixture in this example comprises the following steps:

[0061] (1) Weigh the above components proportionally, stir and mix them evenly to obtain a dry mixture.

[0062] (2) Weigh the dry mixture and water according to a mass ratio of 100﹕3.5 and mix them, stir evenly to obtain a wet mixture.

[0063] (3) Place the wet mixture in a pelletizing machine, press it into balls to obtain spheres of the modifying material for composite admixture, with an average particle size of about 20 mm.

[0064] This example also provides a composite admixture, which comprises 80% of microcrystalline limestone powder by mass percentage and 20% of the spheres of the modifying material for composite admixture as described above. Among them, the preparation of the microcrystalline limestone powder includes: crushing the limestone stone into particles with a size of less than 5 mm, and the fineness characteristics are: the average particle size is 30 μm, D10 = 18 μm, D50 = 33 μm, D90 = 44 μm, and the specific surface area is 430 m 2 / kg. Those skilled in the art should understand that the parameters of the microcrystalline limestone powder listed in this example are only exemplary and should not be construed as a limitation.

[0065] The preparation method of the composite admixture includes: mixing the microcrystalline limestone powder and the spheres of the modifying material proportionally, and then placing them in a mill and grinding to a fineness of 325 mesh ± 25 mesh to obtain the composite admixture.

[0066] Examples 2 - 9

[0067] Examples 2 to 9 refer to the modified material for composite admixture, its preparation method, the composite admixture and its preparation method in Example 1, with the only difference being the dosages of the components of the modified material for composite admixture are different.

[0068] The dosage information of the components of the modified material for composite admixture in Examples 2 to 9 is shown in Table 1.

[0069] Table 1 Dosage information of different examples (parts by weight)

[0070] Number Diatomaceous earth Silica white Glass microspheres Magnesium aluminum silicate Naphthalene sulfonic acid formaldehyde condensate Triisopropanolamine Example 2 40 40 30 6 3 4 Example 3 50 30 20 4 5 2 Example 4 44.3 34.5 26.2 5 4 3 Example 5 46 35.7 23.3 5 4 3 Example 6 48 37 20 5 4 3 Example 7 42 33 30 5 4 3 Example 8 45 35 25 4 4 3 Example 9 45 35 25 6 4 3

[0071] Example 10

[0072] This example refers to the modified material for composite admixture, its preparation method, the composite admixture and its preparation method in Example 1, with the only difference being that in the preparation of the modified material for composite admixture, an equal weight of polycarboxylate superplasticizer is used to replace naphthalene sulfonate formaldehyde condensate.

[0073] Example 11

[0074] This example refers to the modified material for composite admixture, its preparation method, the composite admixture and its preparation method in Example 1, with the only difference being that in the preparation of the modified material for composite admixture, an equal weight of melamine superplasticizer is used to replace naphthalene sulfonate formaldehyde condensate.

[0075] Example 12

[0076] This example refers to the modified material for composite admixture, its preparation method, the composite admixture and its preparation method in Example 1, with the only difference being that in the preparation of the modified material for composite admixture, an equal weight of sodium sulfate is used to replace triisopropanolamine.

[0077] Example 13

[0078] This example refers to the modified material for composite admixture, its preparation method, the composite admixture and its preparation method in Example 1, with the only difference being that in the composite admixture, the contents of the components are different.

[0079] In the composite admixture of this example, it includes 90% of microcrystalline grey rock powder and 10% of the modified material spheres for composite admixture by mass percentage.

[0080] Example 14

[0081] This example refers to the modified material for composite admixture, its preparation method, the composite admixture and its preparation method in Example 1, with the only difference being that in the composite admixture, the contents of the components are different.

[0082] In the composite admixture of this embodiment, it includes 70% of microcrystalline limestone powder and 30% of the modified material spheres for the composite admixture by mass percentage.

[0083] Example 15

[0084] This embodiment refers to the modified material for the composite admixture and its preparation method, the composite admixture and its preparation method in Example 1. The difference is only that in the preparation of the composite admixture, the fineness after grinding is different.

[0085] In the preparation of the composite admixture of this embodiment, it is ground to a fineness of 300 mesh ± 25 mesh.

[0086] Example 16

[0087] This embodiment refers to the modified material for the composite admixture and its preparation method, the composite admixture and its preparation method in Example 1. The difference is only that in the preparation of the composite admixture, the fineness after grinding is different.

[0088] In the preparation of the composite admixture of this embodiment, it is ground to a fineness of 350 mesh ± 25 mesh.

[0089] Comparative Examples 1 - 4

[0090] Comparative Examples 1 - 4 refer to the modified material for the composite admixture and its preparation method, the composite admixture and its preparation method in Example 1. The difference is that the dosages of the components of the modified material for the composite admixture are different.

[0091] Table 2 Dosage information of different comparative examples (parts by weight)

[0092] Number Diatomaceous earth Silica white Glass microspheres Magnesium aluminum silicate Naphthalene sulfonic acid formaldehyde condensate Triisopropanolamine Comparative Example 1 80 / 25 5 4 3 Comparative Example 2 / 80 25 5 4 3 Comparative Example 3 45 35 35 5 4 3 Comparative Example 4 45 35 15 5 4 3

[0093] Comparative Example 5

[0094] Comparative Example 5 refers to the composite admixture and its preparation method in Example 1. The difference is that only microcrystalline limestone powder is used and no modified material is added.

[0095] Experimental Example

[0096] Prepare concrete with the composite admixtures prepared in different examples and comparative examples according to the following ratio, and then test various properties of the concrete. The test results are shown in Table 3.

[0097] The concrete composition (by parts by weight) includes: 290 parts of cement, 80 parts of composite admixture, 860 parts of sand, 1080 parts of stone, 150 parts of water, and 3.5 parts of liquid polycarboxylate - based superplasticizer; the preparation of the concrete includes: mixing the six materials in the above ratio evenly, and then using a mixer to stir for 180 s, and then forming several test blocks to test properties such as strength.

[0098] Test method: The state of the mixture was observed and tested in accordance with the Standard Test Method for Performance of Ordinary Concrete Mixtures (GB / T 50080-2016). The strength test was carried out in accordance with the Standard Test Method for Physical and Mechanical Properties of Concrete (GB / T 50081-2019), and the durability performance was tested in accordance with the Standard Test Method for Long-Term and Durability Performance of Concrete (GB / T 50082-2024).

[0099] Table 3 Test Results of Different Concretes

[0100]

[0101] From the above test results, it can be seen that using the modified material of the present invention to modify the stone powder can greatly improve the comprehensive performance of the composite admixture prepared with a large amount of stone powder, and ensure that the concrete prepared with stone powder has good workability, strength and durability during construction.

[0102] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements for some or all of the technical features; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A modified material for composite admixtures, characterized in that: It includes the following components by weight: 40-50 parts of diatomaceous earth, 30-40 parts of white carbon black, 20-30 parts of glass microspheres, 4-6 parts of magnesium aluminum silicate, 3-5 parts of dispersant and 2-4 parts of activator.

2. The modified material for composite admixture according to claim 1, characterized in that: The dispersant is naphthalenesulfonic acid formaldehyde condensate.

3. The modified material for composite admixture according to claim 1, characterized in that: The activator is triisopropanolamine and / or ethylenediamine.

4. The modified material for composite admixture according to claim 1, characterized in that: The mass ratio of the diatomaceous earth to the white carbon black and to the glass microspheres is (3-3.5):

1.

5. The modified material for composite admixture according to claim 1, characterized in that: The mass ratio of the diatomaceous earth to the white carbon black and to the magnesium aluminum silicate is (15-20):

1.

6. Composite admixture, characterized in that: The invention comprises stone powder and the modified material for composite admixture as claimed in any one of claims 1 to 5.

7. The composite admixture according to claim 6, characterized in that: The mass ratio of the stone powder to the modified material used for the composite admixture is (2-9):

1.

8. The composite admixture according to claim 6, characterized in that: The stone powder is made from slag stone powder; Preferably, the stone powder is at least one of gneiss stone powder and limestone stone powder.

9. The composite admixture according to claim 6, characterized in that: The fineness of the composite admixture is 325 mesh±25 mesh.

10. Concrete, characterized in that The composite admixture comprises the composite admixture described in any one of claims 6 to 9.

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