A kind of anhydrous gypsum-based concrete activated by all solid waste and its preparation method and application

Abstract

The present invention provides an anhydrous gypsum-based concrete activated by all solid waste, and a preparation method and application thereof, belonging to the field of solid waste resource utilization, comprising cementitious materials, fine aggregate, coarse aggregate, a water reducer and water; anhydrous gypsum has extremely low solubility in water, carbide slag can play an alkaline activation role, and yellow phosphorus slag powder and mineral powder, under the activation of carbide slag, generate hydraulic hydration products and calcium aluminate to wrap anhydrous gypsum particles and tightly bond with them to form a stable three-dimensional spatial structure, with greatly enhanced density and water resistance; rice husk ash improves the frost resistance of the material; the concrete prepared by this scheme has high strength, excellent water resistance and frost resistance, and can be used for load-bearing structures in humid environments and cold areas, with a water absorption rate of less than 5%, a softening coefficient of more than 0.85, and more than 100 freeze-thaw cycles; all raw materials are industrial solid waste, do not contain cement clinker, have low cost, energy conservation and emission reduction, and can realize the resource utilization of solid waste.

Description

Technical Field

[0001] The present invention belongs to the field of solid waste resource utilization, and specifically relates to an anhydrous gypsum-based concrete activated by all solid waste, and a preparation method and application thereof. Background Art

[0002] The climate challenges facing humanity today are becoming increasingly severe. Reducing cement use in industrial production and using industrial solid waste to make concrete are of great significance for achieving the "dual carbon" strategic goals and are conducive to sustainable development.

[0003] Phosphogypsum is an industrial waste product discharged during the wet process of phosphoric acid production. For every ton of phosphoric acid produced, 4-5 tons of phosphogypsum are generated. In my country, phosphogypsum is primarily utilized as a resource in cement retarders, for export or external distribution, and for the manufacture of gypsum board, resulting in relatively low utilization. The majority of phosphogypsum remains in storage, exceeding 700 million tons. This large amount of stockpiled phosphogypsum not only encroaches on land, pollutes water and soil, but also negatively impacts the ecological environment. Therefore, there is a need to further develop new applications for phosphogypsum and increase its utilization.

[0004] Similar to cement, phosphogypsum has certain compressive properties, good curing characteristics and plasticity, making it possible to replace cement to prepare concrete. However, due to the presence of harmful substances such as phosphorus and fluorine in phosphogypsum, it will have an adverse effect on groundwater. At the same time, the setting time of commonly used building gypsum is only 3-5 minutes, the setting time is too fast, the workability is poor, the strength is low, and the water resistance is very poor. Therefore, phosphogypsum is converted into anhydrous gypsum at a certain temperature, impurities such as soluble phosphorus and soluble fluorine can be removed therein, water resistance is enhanced, and stability is improved. However, due to the poor gelling properties, low activity and long setting and hardening time of anhydrous gypsum, it needs to be activated when preparing concrete. Summary of the Invention

[0005] In order to solve the above technical problems, the present invention provides an all-solid waste-activated anhydrous gypsum-based concrete composite material and its preparation method and application. Anhydrous gypsum is used as the main material, and mineral powder, rice husk ash, yellow phosphorus slag powder, corn straw ash, and carbide slag are added as cementitious materials. Kaolin tailings are used as fine aggregate and waste ceramics are used as coarse aggregate to prepare an anhydrous gypsum-based concrete that is all-solid waste, low in cost, low-carbon and environmentally friendly, high in strength, and excellent in water resistance and frost resistance.

[0006] To achieve the above-mentioned purpose, the present invention provides a fully solid waste activated anhydrous gypsum-based concrete composite material, comprising 500-800 parts by weight of anhydrous gypsum, 200-400 parts of mineral powder, 10-50 parts of rice husk ash, 50-100 parts of yellow phosphorus slag powder, 10-50 parts of corn straw ash, 10-50 parts of calcium carbide slag, 800-1000 parts of kaolin tailings, 1000-1500 parts of waste ceramics, 2-10 parts of water reducer and 300-500 parts of water.

[0007] Preferably, the anhydrous gypsum is type II anhydrous gypsum; and the mineral powder is type S95 mineral powder.

[0008] Preferably, the SiO2 content in the rice husk ash is greater than 85%; the yellow phosphorus slag powder is a powder cooled after water quenching; the corn straw ash is obtained by removing impurities from corn straw after calcination; and the CaO content in the carbide slag is greater than 90%.

[0009] Preferably, the kaolin tailings are waste materials discharged after kaolin ore dressing, with a particle size of less than 5 mm; the waste ceramics are formed by crushing ceramics, with a particle size of 5 to 15 mm; the water reducer is a polycarboxylic acid water reducer, with a water reduction rate greater than 25%.

[0010] Based on a general inventive concept, this solution also provides a method for preparing anhydrous gypsum-based concrete activated by all-solid waste, characterized in that it comprises the following steps:

[0011] S1. Pour type II anhydrous gypsum, mineral powder, rice husk ash, yellow phosphorus slag powder, corn straw ash and carbide slag into a blender in proportion and mix evenly to obtain a mixed powder;

[0012] S2, pouring kaolin tailings and waste ceramic aggregate into the mixed powder of step S1 and stirring evenly;

[0013] S3, adding a water reducer into water, stirring and dissolving, and then pouring it into the dry material prepared in step S2, stirring evenly, to obtain concrete slurry;

[0014] S4. Pour the mixed slurry in step S3 into a mold and vibrate it on a vibration table. After pouring, place it in a standard curing room for curing to obtain a fully solid waste activated anhydrous gypsum-based concrete composite material.

[0015] Preferably, the stirring time in S1 is 3 min, and the stirring speed is 30-50 r / min.

[0016] Preferably, the stirring time in S2 is 3 min, and the stirring speed is 30-50 r / min.

[0017] Preferably, the stirring time in S3 is 3-5 min and the stirring speed is 50 r / min.

[0018] Preferably, the vibration time in S4 is 2 minutes.

[0019] Based on a general inventive concept, the present invention also provides an application of all-solid waste activated anhydrous gypsum-based concrete in compressive building materials.

[0020] The preparation principle of all-solid waste activated water gypsum concrete in this scheme is as follows:

[0021] The present invention uses Type II anhydrous gypsum as the primary material, and adds mineral powder, rice husk ash, yellow phosphorus slag powder, corn straw ash, and carbide slag as cementitious materials. Kaolin tailings are used as fine aggregate, and discarded ceramics are used as coarse aggregate to prepare anhydrous gypsum-based concrete. Because Type II anhydrous gypsum has low hydration activity, a long setting and hardening time, and relatively average water resistance, it requires activation when used as a building material.

[0022] Anhydrous gypsum has very low solubility in water. Carbide slag can play an alkaline excitation role and release OH in water. - , which greatly promotes the dissolution of anhydrous gypsum in water, forms a saturated solution of anhydrous gypsum and combines with water to form dihydrate gypsum in a relatively short period of time, but the water resistance of dihydrate gypsum is very poor. At the same time, due to the excessively rapid hydration reaction, the hydration heat release is relatively violent, which has a negative impact on the late strength of the hardened body. Mineral powder, corn straw ash, yellow phosphorus slag powder and rice husk ash are usually inert in water and difficult to hydrate. After being added to anhydrous gypsum, they compete with the hydration of anhydrous gypsum, delaying the excessively fast hydration reaction rate of anhydrous gypsum stimulated by single calcium carbide slag, resulting in only a small part of anhydrous gypsum being hydrated. Most of the anhydrous gypsum eventually plays a filling role in the form of micro-aggregate, and the dihydrate gypsum with poor water resistance produced is greatly reduced.

[0023] Yellow phosphorus slag powder and mineral powder contain aluminum phase and silicon oxygen group. Under the stimulation of carbide slag, the active calcium group and silicon aluminum components in yellow phosphorus slag powder and mineral powder are OH- － Hydrolysis generates free cations and produces hydraulic hydration products such as hydrated calcium silicate and hydrated calcium aluminate. At the same time, the dissolution of anhydrous gypsum provides SO4 in the solution. 2-, prompting the hydration reaction to generate a substance that is insoluble in water - calcium aluminite. The hydraulic hydration products and calcium aluminite wrap the anhydrous gypsum particles and tightly bond with them to form a stable three-dimensional spatial structure, which greatly enhances the density and water resistance. Since the particle size of rice husk ash is extremely small, it can improve the pore size distribution of anhydrous gypsum concrete, fill the tiny pores and cracks inside the hardened body, and improve the weak interface transition zone between the aggregate and the cementitious slurry in the hardened body, making the concrete more uniform and dense, and improving the frost resistance. Industrial solid waste kaolin tailings and waste ceramics are used as fine aggregate and coarse aggregate respectively, with high glass content and strong water resistance. At the same time, it can avoid the excessive exploitation of resources such as river sand and ore, and realize the reuse of industrial solid waste.

[0024] Compared with the prior art, the present invention has the following beneficial effects:

[0025] (1) This proposal provides a fully solid waste-activated anhydrous gypsum-based concrete and its preparation method, filling a gap in this field. Anhydrous gypsum is used as the main material, and solid waste mineral powder, rice husk ash, yellow phosphorus slag powder, corn straw ash, and carbide slag are added as cementitious materials. Kaolin tailings are used as fine aggregate and waste ceramics are used as coarse aggregate. The fully solid waste-activated anhydrous gypsum is used to prepare anhydrous gypsum-based concrete. This can promote the development of solid waste-based concrete preparation and is of great significance for the resource utilization of solid waste, reducing environmental pollution, and achieving green and sustainable development in the construction industry.

[0026] (2) The apparent density of the all-solid waste activated anhydrous gypsum-based concrete prepared by this scheme is less than 2200 kg / m 3 , light weight, 28-day flexural strength can reach more than 8MPa, compressive strength can reach more than 40MPa, and high strength.

[0027] (3) The water absorption rate of the all-solid waste-activated anhydrous gypsum-based concrete prepared in this scheme is less than 5%, and the softening coefficient reaches above 0.85, which meets the standards for being a moisture-proof building material. At the same time, the freeze-thaw cycle is greater than 100 times, and the frost resistance is good.

[0028] (4) The raw materials used in the all-solid waste-activated anhydrous gypsum-based concrete prepared by this scheme are all industrial solid waste, which is low-carbon and environmentally friendly, energy-saving and emission-reducing, and can achieve efficient utilization of solid waste resources and reduce pollution to the environment. DETAILED DESCRIPTION

[0029] In order to make the technical problems, technical solutions and advantages to be solved by the present invention clearer, a detailed description will be given below with reference to specific embodiments.

[0030] The following examples are provided to illustrate the present invention but are not intended to limit the scope of the present invention. Without departing from the spirit and substance of the present invention, modifications or substitutions made to the methods, steps or conditions of the present invention are within the scope of the present invention.

[0031] Unless otherwise specified, the technical means used in the examples are conventional means well known to those skilled in the art; unless otherwise specified, the reagents used in the examples are commercially available.

[0032] Example 1 Preparation of all-solid waste activated anhydrous gypsum-based concrete

[0033] (1) 500 parts of type II anhydrous gypsum, 380 parts of S95 mineral powder, 10 parts of rice husk ash (SiO2 content greater than 85%), 50 parts of yellow phosphorus slag powder (powder cooled after water quenching), 40 parts of corn straw ash (calcined to remove impurities) and 20 parts of calcium carbide slag (CaO content greater than 90%) were poured into a blender and stirred at a speed of 50 r / min for 3 minutes to obtain a mixed powder;

[0034] (2) 800 parts of tailings (waste discharged after kaolin ore dressing) and 1200 parts of waste ceramic aggregate (particle size of 5-15 mm) were poured into the mixed powder of step (1) and stirred at a speed of 50 r / min for 3 min;

[0035] (3) adding 3 parts of a polycarboxylate water-reducing agent having a water-reducing rate greater than 25% to 340 parts of water, stirring and dissolving the mixture, and then pouring the mixture into the dry material prepared in step (2), stirring at a speed of 50 r / min for 4 minutes to obtain a concrete slurry;

[0036] (4) Pour the mixed slurry in step (3) into a mold and vibrate it on a vibration table for 2 minutes. After pouring, place it in a standard curing room for curing to obtain a fully solid waste-activated anhydrous gypsum-based concrete.

[0037] Example 2 Preparation of all-solid waste activated anhydrous gypsum-based concrete

[0038] (1) 500 parts of anhydrous gypsum, 300 parts of S95 mineral powder, 40 parts of rice husk ash (SiO2 content greater than 85%), 100 parts of yellow phosphorus slag powder (powder cooled after water quenching), 40 parts of corn straw ash (calcined to remove impurities) and 20 parts of calcium carbide slag (CaO content greater than 90%) were poured into a 30 rpm mixer and stirred for 3 minutes to obtain a mixed powder;

[0039] (2) 800 parts of kaolin tailings (waste material discharged after kaolin ore beneficiation, with a particle size of less than 5 mm) and 1200 parts of waste ceramic aggregate (particle size of 5 to 15 mm) were poured into the mixed powder of step (1) and stirred in a 30 rpm mixer for 3 minutes;

[0040] (3) adding 5 parts of a polycarboxylate water-reducing agent having a water-reducing rate greater than 25% to 340 parts of water, stirring and dissolving the mixture, and then pouring the mixture into the dry material prepared in step (2), stirring the mixture in a mixer at 50 rpm for 4 minutes to obtain a concrete slurry;

[0041] (4) Pour the mixed slurry in step (3) into a mold and vibrate it on a vibration table for 2 minutes. After pouring, place it in a standard curing room for curing to obtain a fully solid waste-activated anhydrous gypsum-based concrete.

[0042] Example 3 Preparation of all-solid waste activated anhydrous gypsum-based concrete

[0043] (1) 550 parts of type II anhydrous gypsum, 320 parts of type S95 mineral powder, 20 parts of rice husk ash (SiO2 content greater than 85%), 60 parts of yellow phosphorus slag powder (powder cooled after water quenching), 30 parts of corn straw ash (calcined to remove impurities) and 20 parts of calcium carbide slag (CaO content greater than 90%) were poured into a blender in proportion and stirred at 50 r / min for 3 minutes to obtain a mixed powder;

[0044] (2) Pour 1000 parts of kaolin tailings (waste material discharged after kaolin ore dressing, with a particle size of less than 5 mm) and 1000 parts of waste ceramic aggregate (particle size of 5 to 15 mm) into the mixed powder of step (1) and stir at 50 r / min for 3 min;

[0045] (3) adding 4 parts of a polycarboxylate water-reducing agent having a water-reducing rate greater than 25% to 340 parts of water, stirring and dissolving the mixture, and then pouring the mixture into the dry material prepared in step (2), stirring at 50 rpm for 4 minutes to obtain a concrete slurry;

[0046] (4) Pour the mixed slurry in step (3) into a mold and vibrate it on a vibration table for 2 minutes. After pouring, place it in a standard curing room for curing to obtain a fully solid waste-activated anhydrous gypsum-based concrete.

[0047] Example 4 Preparation of all-solid waste activated anhydrous gypsum-based concrete

[0048] (1) 600 parts of type II anhydrous gypsum, 300 parts of type S95 mineral powder, 10 parts of rice husk ash (SiO2 content greater than 85%), 50 parts of yellow phosphorus slag powder (powder cooled after water quenching), 20 parts of corn straw ash (calcined to remove impurities) and 20 parts of calcium carbide slag (CaO content greater than 90%) were poured into a blender in proportion and stirred at 50 rpm for 3 minutes to obtain a mixed powder;

[0049] (2) Pour 1000 parts of kaolin tailings (waste material discharged after kaolin ore dressing, with a particle size of less than 5 mm) and 1000 parts of waste ceramic aggregate (particle size of 5 to 15 mm) into the mixed powder of step (1) and stir at 50 r / min for 3 min;

[0050] (3) adding 5 parts of a polycarboxylate water-reducing agent having a water-reducing rate greater than 25% to 340 parts of water, stirring and dissolving the mixture, and then pouring the mixture into the dry material prepared in step (2), stirring at 50 rpm for 4 minutes to obtain a concrete slurry;

[0051] (4) Pour the mixed slurry in step (3) into a mold and vibrate it on a vibration table for 2 minutes. After pouring, place it in a standard curing room for curing to obtain a fully solid waste-activated anhydrous gypsum-based concrete.

[0052] Comparative Example 1 Preparation of anhydrous gypsum-based concrete without rice husk ash

[0053] (1) 500 parts of type II anhydrous gypsum, 380 parts of S95 mineral powder, 50 parts of yellow phosphorus slag powder (water quenched and cooled), 40 parts of corn straw ash (calcined to remove impurities), and 20 parts of carbide slag (CaO content greater than 90%) were poured into a blender and stirred at a speed of 50 r / min for 3 minutes to obtain a mixed powder;

[0054] (2) 800 parts of tailings (waste discharged after kaolin ore dressing) and 1200 parts of waste ceramic aggregate (particle size of 5-15 mm) were poured into the mixed powder of step (1) and stirred at a speed of 50 r / min for 3 min;

[0055] (3) adding 3 parts of a polycarboxylate water-reducing agent having a water-reducing rate greater than 25% to 340 parts of water, stirring and dissolving the mixture, and then pouring the mixture into the dry material prepared in step (2), stirring at a speed of 50 r / min for 4 minutes to obtain a concrete slurry;

[0056] (4) Pour the mixed slurry in step (3) into a mold and vibrate it on a vibration table for 2 minutes. After pouring, place it in a standard curing room for curing to obtain a fully solid waste-activated anhydrous gypsum-based concrete.

[0057] Comparative Example 2 Preparation of anhydrous gypsum-based concrete without yellow phosphorus slag powder and mineral powder

[0058] (1) 500 parts of type II anhydrous gypsum, 10 parts of rice husk ash (SiO2 content greater than 85%), 40 parts of corn straw ash (calcined to remove impurities) and 20 parts of carbide slag (CaO content greater than 90%) were poured into a blender and stirred at a speed of 50 r / min for 3 minutes to obtain a mixed powder;

[0059] (2) 800 parts of tailings (waste discharged after kaolin ore dressing) and 1200 parts of waste ceramic aggregate (particle size of 5-15 mm) were poured into the mixed powder of step (1) and stirred at a speed of 50 r / min for 3 min;

[0060] (3) adding 3 parts of a polycarboxylate water-reducing agent having a water-reducing rate greater than 25% to 340 parts of water, stirring and dissolving the mixture, and then pouring the mixture into the dry material prepared in step (2), stirring at a speed of 50 r / min for 4 minutes to obtain a concrete slurry;

[0061] (4) Pour the mixed slurry in step (3) into a mold and vibrate it on a vibration table for 2 minutes. After pouring, place it in a standard curing room for curing to obtain a fully solid waste-activated anhydrous gypsum-based concrete.

[0062] Comparative Example 3 Preparation of anhydrous gypsum-based concrete without tailings

[0063] (1) 500 parts of type II anhydrous gypsum, 10 parts of rice husk ash (SiO2 content greater than 85%), 40 parts of corn straw ash (calcined to remove impurities) and 20 parts of carbide slag (CaO content greater than 90%) were poured into a blender and stirred at a speed of 50 r / min for 3 minutes to obtain a mixed powder;

[0064] (2) Pour 1200 parts of waste ceramic aggregate (particle size of 5-15 mm) into the mixed powder of step (1) and stir at a speed of 50 r / min for 3 minutes;

[0065] (3) adding 3 parts of a polycarboxylate water-reducing agent having a water-reducing rate greater than 25% to 340 parts of water, stirring and dissolving the mixture, and then pouring the mixture into the dry material prepared in step (2), stirring at a speed of 50 r / min for 4 minutes to obtain a concrete slurry;

[0066] (4) Pour the mixed slurry in step (3) into a mold and vibrate it on a vibration table for 2 minutes. After pouring, place it in a standard curing room for curing to obtain a fully solid waste-activated anhydrous gypsum-based concrete.

[0067] Experimental Example 1: Investigation of the properties of anhydrous gypsum-based concrete

[0068] According to GB / T 50081-2019, GB / T 50082-2009, GB / T 4111-2013, T / CBMF36-2018 and other standards, the all-solid waste activated anhydrous gypsum-based concrete prepared in Examples 1-4 and Comparative Examples 1-2 were tested, and the specific results are shown in Table 1.

[0069]

[0070]

[0071] GB 55007-2021 stipulates that the softening coefficient of load-bearing component materials used in humid environments and freeze-thaw environments should be no less than 0.9, and frost resistance requires that the compressive strength loss rate does not exceed 25% and the mass loss rate does not exceed 5%. Comparing Examples 1-4 with Comparative Example 1, it can be seen that the water resistance and frost resistance of the anhydrous gypsum-based concrete of the comparative example without the addition of rice husk ash have been significantly reduced. After 100 freeze-thaw cycles, the mass loss rate of the anhydrous gypsum-based concrete without the addition of rice husk ash has reached 5.29%, indicating that the addition of rice husk ash significantly improves the frost resistance of the anhydrous gypsum-based concrete.

[0072] Anhydrous gypsum-based concrete without yellow phosphorus slag powder and mineral powder has poor density due to the very small amount of hydraulic hydration products such as hydrated calcium silicate, hydrated calcium aluminate and ettringite produced, which leads to a significant reduction in strength, water resistance and frost resistance.

[0073] Anhydrous gypsum-based concrete without tailings is composed only of coarse aggregate and cementitious materials, lacking fine aggregate, and forming a large number of unclosed macropores inside. These macropores provide channels for the penetration of water molecules, resulting in a significant reduction in water resistance and frost resistance.

[0074] In summary, the apparent density of the anhydrous gypsum-based composite cementitious materials in the embodiments is less than 2200 kg / m 3 The apparent density is low. At the same time, under natural curing, the flexural strength can reach over 8MPa and the compressive strength can reach over 40MPa after 28 days. These characteristics are high strength, with a water absorption rate of less than 5%, a softening coefficient greater than 0.85, good water resistance, and excellent frost resistance. It can be used in load-bearing structures in humid environments and cold regions. Furthermore, since the raw materials are all solid waste materials and no cement is added, the cost is low, it is green, energy-saving, low-carbon and environmentally friendly, and can achieve resource utilization of industrial solid waste.

[0075] The above is only a preferred embodiment of the present invention, and the scope of protection of the present invention is not limited to the above embodiment. For those skilled in the art, improvements and modifications obtained without departing from the technical concept of the present invention should also be considered as the scope of protection of the present invention.

Claims

1. A fully solid waste-inspired anhydrous gypsum-based concrete, characterized in that: The invention comprises the following components by weight: 500-800 parts of anhydrous gypsum, 200-400 parts of mineral powder, 10-50 parts of rice husk ash, 50-100 parts of yellow phosphorus slag powder, 10-50 parts of corn straw ash, 10-50 parts of carbide slag, 800-1000 parts of kaolin tailings, 1000-1500 parts of waste ceramics, 2-10 parts of water reducer and 300-500 parts of water.

2. The all-solid waste activated anhydrous gypsum-based concrete according to claim 1, characterized in that: The anhydrous gypsum is type II anhydrous gypsum; the mineral powder is type S95 mineral powder.

3. The all-solid waste activated anhydrous gypsum-based concrete according to claim 1, characterized in that: The SiO2 content in the rice husk ash is greater than 85%; the yellow phosphorus slag powder is powder obtained by cooling after water quenching; the corn straw ash is obtained by removing impurities from corn straw after calcination; and the CaO content in the carbide slag is greater than 90%.

4. The all-solid waste activated anhydrous gypsum-based concrete according to claim 1, characterized in that: The kaolin tailings are waste materials discharged after kaolin ore dressing, with a particle size of less than 5mm; the waste ceramics are formed by crushing ceramics, with a particle size of 5-15mm; the water reducer is a polycarboxylic acid water reducer, with a water reduction rate greater than 25%.

5. A method for preparing anhydrous gypsum-based concrete activated by all-solid waste according to any one of claims 1 to 4, characterized in that: The following steps are involved: S1. Pour type II anhydrous gypsum, mineral powder, rice husk ash, yellow phosphorus slag powder, corn straw ash and carbide slag into a blender in proportion and mix evenly to obtain a mixed powder; S2, pouring kaolin tailings and waste ceramic aggregate into the mixed powder of step S1 and stirring evenly; S3, adding a water reducer into water, stirring and dissolving, and then pouring it into the dry material prepared in step S2, stirring evenly, to obtain concrete slurry; S4. Pour the mixed slurry in step S3 into a mold and vibrate it on a vibration table. After pouring, place it in a standard curing room for curing to obtain a fully solid waste activated anhydrous gypsum-based concrete composite material.

6. The preparation method according to claim 5, characterized in that The stirring time in S1 is 3 minutes, and the stirring speed is 30-50 r / min.

7. The preparation method according to claim 5, characterized in that The stirring time in S2 is 3 minutes, and the stirring speed is 30-50 r / min.

8. The preparation method according to claim 5, characterized in that The stirring time in S3 is 3 to 5 minutes, and the stirring speed is 50 r / min.

9. The preparation method according to claim 5, characterized in that The vibration time in S4 is 2 minutes.

10. Use of the all-solid waste activated anhydrous gypsum-based concrete according to any one of claims 1 to 4 or the all-solid waste activated anhydrous gypsum-based concrete prepared by the preparation method according to any one of claims 5 to 9 in compressive building materials.

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