A high-content composite stone powder foam concrete and its preparation method

Abstract

The present invention belongs to the technical field of solid waste utilization and foam concrete preparation, and specifically relates to a high-dosage composite stone powder foam concrete and a preparation method thereof. The foam concrete preparation materials are, by weight, 10-20 parts of coarse stone powder, 30-40 parts of fine stone powder, 2-3 parts of ultrafine stone powder, 30-40 parts of cement, 0.16-0.2 parts of foaming agent, 0.4-1 parts of water reducing agent, 0.8-1.5 parts of coagulant and 25-35 parts of water; the specific surface area of ​​the coarse stone powder is 50-300m 2 / kg; the specific surface area of ​​the fine stone powder is 300~600m 2 / kg; the specific surface area of ​​the ultrafine stone powder is 5000~9000m 2 / kg, the high-content composite stone powder foam concrete prepared by the present invention has high stone powder content, stable mechanical properties, is green and economical, and has good market promotion prospects.

Description

Technical Field

[0001] The invention belongs to the technical field of solid waste utilization and foam concrete preparation, and specifically discloses a high-content composite stone powder foam concrete and a preparation method thereof. Background Art

[0002] The crushing process in the production of manufactured sand and gravel in mines generates a large amount of stone dust. Furthermore, the crushing of lower-quality rock (weathered sludge) also produces a significant amount of stone dust. The lithology of this stone dust depends on the lithology of the mine. Some mines contain a variety of rock types, resulting in a variety of stone dust, such as granite and gneiss. This stone dust is characterized by its often very fine particle size, frequently appearing as dust on production lines. Inhalation of these dust particles can cause serious respiratory illnesses such as bronchitis, asthma, and lung disease. Therefore, production lines often utilize dust removal equipment to collect the stone dust. With the continuous advancement of manufactured sand and gravel production, the amount of stone dust stored on-site at mines has increased, and the area occupied by the dust is also increasing. To prevent these fine particles from escaping into the surrounding environment and disrupting the ecological balance, production personnel have to invest significant manpower and resources in storing this waste stone dust. Therefore, how to quickly and efficiently dispose of this waste stone dust has become a pressing challenge for manufactured sand and gravel mining companies.

[0003] Foam concrete is a lightweight porous material composed of cementitious materials, aggregates, water, foaming agents, etc. It has good thermal insulation, heat insulation, sound insulation, fire resistance, energy absorption and other properties. It is widely used in the fields of construction, geotechnical engineering, transportation, gardening and municipal engineering, and has a wide range of uses. If the stone powder produced by the production of artificial sand and gravel in mines can be applied to foam concrete, a large amount of stone powder can be quickly absorbed. However, the current research and application results of applying stone powder to foam concrete show that the amount of stone powder in foam concrete is low and the mechanical properties of the foam concrete prepared therefrom are poor. In response to the above problems, the present invention proposes a high-content composite stone powder foam concrete and a preparation method thereof, the purpose of which is to increase the amount of stone powder in foam concrete without significantly deteriorating the mechanical properties of foam concrete, and to apply stone powder waste to foam concrete products to the greatest extent, so as to solve the current problem that some mines producing artificial sand and gravel enterprises urgently need to absorb stone powder waste, and at the same time realize the transformation of stone powder into treasure. Summary of the Invention

[0004] The main purpose of the present invention is to apply the stone powder waste generated in the process of producing machine-made sand and gravel to foam concrete, reduce the harm that may be caused by a large amount of accumulated stone powder, and realize its high added value utilization.

[0005] To achieve the above objectives, the present invention provides the following technical solutions:

[0006] The high-content composite stone powder foam concrete is prepared from the following materials, calculated by weight: 10-20 parts of coarse stone powder, 30-40 parts of fine stone powder, 2-3 parts of ultrafine stone powder, 30-40 parts of cement, 0.16-0.2 parts of foaming agent, 0.4-1 parts of water reducing agent, 0.8-1.5 parts of setting accelerator and 25-35 parts of water.

[0007] Preferably, the coarse stone powder is stone powder produced by the process of crushing machine-made sand and gravel, with a specific surface area of ​​50 to 300 m 2 / kg, the lithology of the stone powder is granite and gneiss, and the mass ratio of granite to gneiss in the stone powder is 0.5 to 4:1.

[0008] Preferably, the fine stone powder is stone powder produced in the process of machine-made sand and gravel crushing, with a specific surface area of ​​300 to 600 m 2 / kg, the rock type of the stone powder is granite or gneiss, and the mass ratio of granite to gneiss in the stone powder is: 1 to 4:1.

[0009] Preferably, the ultrafine stone powder is stone powder produced in the process of machine-made sand and gravel crushing and obtained by wet grinding, with a specific surface area of ​​5000 to 9000 m 2 / kg, the stone powder is granite.

[0010] Preferably, the cement is ordinary Portland cement.

[0011] Preferably, the foaming agent is LG-2258 cement foaming agent, produced by Shandong Yousuo Chemical Technology Co., Ltd.

[0012] Preferably, the water reducer is a naphthalene-based water reducer.

[0013] Preferably, the coagulant is anhydrous calcium chloride.

[0014] Preferably, the water is tap water, wherein chloride ≤ 250 mg / L, sulfate ≤ 250 mg / L, and total dissolved solids ≤ 1000 mg / L.

[0015] Furthermore, the present invention also provides a method for preparing high-content composite stone powder foam concrete, comprising the following steps:

[0016] 1) Measure each group of materials according to mass ratio and set aside;

[0017] 2) Dissolve the coagulant completely in tap water and wait for the mixture of water and coagulant to cool to room temperature before use;

[0018] 3) Dilute the foaming agent with tap water at a dilution ratio of 40 to 60 times (mix this product with 40 to 60 times the mass of tap water), and pour the ultrafine stone powder into the diluted foaming agent, stir it in a magnetic stirrer for 5 to 10 minutes to obtain the foam liquid to be used.

[0019] 4) Add coarse and fine stone powder and cement into a mortar mixing pot and stir at a rotation speed of 140±5r / min for 2 minutes to prepare a mixed dry material. Then add a mixture of water and coagulant into the mortar mixing pot and stir at a rotation speed of 140±5r / min for 1.5 minutes to prepare a mixed slurry;

[0020] 5) The prepared foam liquid is passed through a foaming machine to obtain uniform foam, and the foam is added to the mixed slurry and stirred at a rotation speed of 140±5r / min for 1 minute. Then, the stirring pot is removed and the material remaining on the pot wall and bottom is scraped with a tool; the stirring pot is returned to the stirring pot and continued to be stirred at a rotation speed of 140±5r / min for 1-2 minutes to ensure that the foam is evenly dispersed in the mixed slurry. When the final mixture has a creamy, fluid consistency that is easy to pour, a high-content composite stone powder foam concrete slurry is obtained;

[0021] 6) The obtained creamy foamed concrete slurry was injection molded, covered with a polyethylene film and placed in an environment at a temperature of 23±2°C and a relative humidity of 65±15% until it hardened and then demolded. After demolding, it was placed in an environment at a temperature of 20±2°C and a relative humidity of more than 95% and cured for 28 days to prepare a high-content composite stone powder foamed concrete.

[0022] The high-content composite stone powder foam concrete prepared by the present invention has the following advantages:

[0023] 1) The present invention uses stone powder produced in the crushing process of machine-made sand and gravel and weathered stripping materials in mining as the main raw material. The strength of the foamed concrete produced is stable and the utilization rate of stone powder in solid raw materials is as high as over 55%. On the one hand, the foamed concrete can absorb a large amount of stone powder waste, turning stone powder into treasure; on the other hand, using more stone powder to replace cement (producing 1 ton of cement will produce about 1 ton of carbon dioxide and other gases), which is very consistent with the current "dual carbon policy". The more stone powder replaces cement, the more significant the low-carbon effect of the product and the more obvious the economy. In addition, the dry density, thermal conductivity, compressive strength and water absorption properties of high-content composite stone powder foam concrete meet the corresponding requirements of the JG / T266-2011 "Foamed Concrete" standard. Overall, the product is green, economical and has better performance, giving it a broad market promotion prospect.

[0024] 2) The present invention adds a coagulant to the foamed concrete. On the one hand, it can promote the cement hydration reaction, which is beneficial to the structural stability of the foamed concrete and plays a role in optimizing the mechanical properties of the foamed concrete. On the other hand, it is beneficial to shorten the setting time of the foamed concrete, speed up the turnover of the formwork, and improve the production efficiency of the product.

[0025] 3) The molding and mechanical properties of foam concrete depend largely on the quality of the foam. The present invention uses ultrafine stone powder obtained by wet grinding to improve the stability of the foam, prevent the foam from bursting, and thus improve the strength of the final foam concrete. The improvement mechanism of ultrafine stone powder is as follows: on the one hand, the ultrafine stone powder attached to the foam liquid film increases the flow resistance of the liquid on the liquid film, which limits the removal of the liquid. The presence of the liquid inhibits the bursting of the foam and the diffusion of the gas, thereby improving the stability of the foam; on the other hand, the ultrafine stone powder can also absorb the free energy on the liquid film, which inhibits the reduction of the surface tension of the foam, which can make the foam show higher uniformity and strength.

[0026] 4) The invention incorporates coarse stone powder of appropriate particle size into foamed concrete to refine the pore structure of the foamed concrete, thereby improving the mechanical properties of the foamed concrete. Furthermore, the appropriate amount of coarse stone powder enhances the fluidity and plasticity of the foamed concrete, thereby improving its workability, ensuring the overall uniformity of the foamed concrete, and optimizing its mechanical properties.

[0027] 5) The present invention incorporates granite powder and gneiss powder, which can produce a synergistic effect and improve the performance of foam concrete better than single addition. In terms of particle shape, granite powder is generally spherical, while gneiss powder is generally flaky. The different particle shapes of the two give them respective advantages and disadvantages when applied to foam concrete. By mixing the two kinds of stone powder in appropriate proportions, they can complement each other's strengths and overcome their weaknesses, thereby significantly improving the performance of foam concrete. The specific analysis is as follows: First, the flaky particle shape of gneiss powder is not conducive to the fluidity of foam concrete. By adding appropriate granite to gneiss, the spherical particle shape of granite can improve the working performance of foam concrete, thereby ensuring the overall uniformity of foam concrete and optimizing the mechanical properties. Second, the different particle shapes of gneiss and granite allow cement to grow and nucleate (nucleation) on them in various forms, which is more conducive to the hydration reaction of cement, generating more hydration products, thereby improving the mechanical properties of foam concrete. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 The foamed concrete paste mixture exhibits a creamy, easy-to-pour fluid consistency.

[0029] Figure 2 A diagram showing granite and gneiss samples from the mine site;

[0030] Figure 3 Diagram showing samples of coarse stone powder, fine stone powder and ultrafine stone powder.

[0031] Figure 4 The foam concrete product is shown in the following figure:

[0032] Figure 5 Comparative Example 4 shows the foam concrete product.

[0033] Figure 6 Example 2 shows the foamed concrete product.

[0034] Figure 7 The foam concrete product is shown in the following figure:

[0035] Figure 8 The foam concrete product shown in Figure 3 is implemented under control example 3. DETAILED DESCRIPTION

[0036] In order to make the purpose, technical solutions and advantages of the present invention clearer, the technical solutions of the present invention are described clearly and completely below. Obviously, the embodiments described are part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention. Figure 2 、 3 , all materials can be purchased directly from the market, and the specific material specifications are as follows:

[0037] Coarse stone powder is produced in the process of machine-made sand and gravel crushing, with a specific surface area of ​​50 to 300 m 2 / kg, the lithology of the stone powder is granite and gneiss, and the mass ratio of granite to gneiss in the stone powder is 0.5 to 4:1.

[0038] Fine stone powder is stone powder produced in the process of machine-made sand and gravel crushing, with a specific surface area of ​​300 to 600 m 2 / kg, the lithology of the stone powder is granite and gneiss, and the mass ratio of granite to gneiss in the stone powder is 1 to 4:1.

[0039] Ultrafine stone powder is produced in the process of machine-made sand and gravel crushing and is obtained through wet grinding. Its specific surface area is 5000~9000m 2 / kg, the stone powder is granite.

[0040] The cement is ordinary Portland cement.

[0041] The foaming agent is LG-2258 cement foaming agent, produced by Shandong Yousuo Chemical Technology Co., Ltd.

[0042] The water reducer is a naphthalene-based water reducer.

[0043] The coagulant is anhydrous calcium chloride with analytical purity.

[0044] The water is tap water, with chloride ≤ 250 mg / L, sulfate ≤ 250 mg / L, and total dissolved solids ≤ 1000 mg / L.

[0045] Example 1

[0046] A high-content composite stone powder foam concrete consists of 10 parts of coarse stone powder, 30 parts of fine stone powder, 2 parts of ultrafine stone powder, 30 parts of cement, 0.17 parts of foaming agent, 0.45 parts of water reducing agent, 0.85 parts of setting accelerator and 26 parts of water, calculated by weight.

[0047] The dilution ratio of the foaming agent is 40 times (the mass ratio of the foaming agent to tap water is 1:40), the mass ratio of granite to gneiss in the coarse stone powder is 2.5:1, and the specific surface area of ​​the coarse stone powder is 60m 2 / kg, the mass ratio of granite to gneiss in the fine stone powder is 1:1, and the specific surface area of ​​the fine stone powder is 380m 2 / kg, the specific surface area of ​​ultrafine stone powder is 5500m 2 / kg.

[0048] The preparation method of high-content stone powder foam concrete comprises the following steps:

[0049] 1) Measure the materials of each group according to the mass ratio and set aside;

[0050] 2) Dissolve the coagulant completely in tap water and wait for the mixture of water and coagulant to cool to room temperature before use;

[0051] 3) Dilute the foaming agent with tap water at a dilution ratio of 40 times, pour the ultrafine stone powder into the diluted foaming agent, and stir it in a magnetic stirrer for 5 to 10 minutes to obtain the foam liquid to be used.

[0052] 4) Add coarse and fine stone powder and cement into a mortar mixing pot and stir at a rotation speed of 140±5r / min for 2 minutes to prepare a mixed dry material. Then add a mixture of water and coagulant into the mortar mixing pot and stir at a rotation speed of 140±5r / min for 1.5 minutes to prepare a mixed slurry;

[0053] 5) The prepared foam liquid is passed through a foaming machine to obtain uniform foam, and the foam is added to the mixed slurry and stirred at a speed of 140±5r / min for 1 minute. Then, the stirring pot is removed and the material remaining on the pot wall and bottom is scraped with a tool; the stirring pot is returned to the stirring pot and stirred at a speed of 140±5r / min for 1-2 minutes to ensure that the foam is evenly dispersed in the mixed slurry. The final mixture has a creamy, fluid consistency that is easy to pour (below Figure 1 ) when a high content of composite stone powder foam concrete paste is obtained;

[0054] 6) The obtained creamy foamed concrete slurry was injection molded, covered with a polyethylene film and placed in an environment at a temperature of 23±2°C and a relative humidity of 65±15% until it hardened and then demolded. After demolding, it was placed in an environment at a temperature of 20±2°C and a relative humidity of more than 95% and cured for 28 days to prepare a high-content composite stone powder foamed concrete.

[0055] Example 2

[0056] A high-content composite stone powder foam concrete consists of 14.6 parts of coarse stone powder, 35 parts of fine stone powder, 2.2 parts of ultrafine stone powder, 35.8 parts of cement, 0.18 parts of foaming agent, 0.73 parts of water reducing agent, 1.2 parts of setting accelerator and 29.7 parts of water, calculated by weight.

[0057] The dilution ratio of the foaming agent is 50 times (the mass ratio of the foaming agent to tap water is 1:50), the mass ratio of granite to gneiss in the coarse stone powder is 3:1, and the specific surface area of ​​the coarse stone powder is 150m 2 / kg, the mass ratio of granite to gneiss in the fine stone powder is 3:1, and the specific surface area of ​​the fine stone powder is 430m 2 / kg, the specific surface area of ​​ultrafine stone powder is 7200m 2 / kg, the preparation steps are the same as those in Example 1.

[0058] Example 3

[0059] A high-content composite stone powder foam concrete consists of 20 parts of coarse stone powder, 40 parts of fine stone powder, 3 parts of ultrafine stone powder, 40 parts of cement, 0.2 parts of foaming agent, 0.95 parts of water reducing agent, 1.45 parts of setting accelerator and 35 parts of water, calculated by weight.

[0060] The dilution ratio of the foaming agent is 60 times (the mass ratio of the foaming agent to tap water is 1:60), the mass ratio of granite to gneiss in the coarse stone powder is 4:1, and the specific surface area of ​​the coarse stone powder is 230m 2 / kg, the mass ratio of granite to gneiss in the fine stone powder is 4:1, and the specific surface area of ​​the fine stone powder is 550m 2 / kg, the specific surface area of ​​ultrafine stone powder is 8500m 2 / kg, and the preparation steps are the same as those in Example 1.

[0061] Comparative Example 1 (the foamed concrete of this scheme does not contain coarse stone powder)

[0062] A high-content composite stone powder foam concrete consists of 35 parts of fine stone powder, 2.2 parts of ultrafine stone powder, 35.8 parts of cement, 0.18 parts of foaming agent, 0.73 parts of water reducing agent, 1.2 parts of setting accelerator and 29.7 parts of water, calculated by weight.

[0063] The dilution ratio of the foaming agent is 50 times (the mass ratio of the foaming agent to tap water is 1:50), the mass ratio of granite to gneiss in the fine stone powder is 3:1, and the specific surface area of ​​the fine stone powder is 430m 2 / kg, the specific surface area of ​​ultrafine stone powder is 7200m 2 / kg, the preparation steps are roughly the same as those in Example 1, except that the coarse stone powder is not added.

[0064] Comparative Example 2 (the foaming agent of this solution is not pretreated with ultrafine stone powder)

[0065] A high-content composite stone powder foam concrete consists of 14.6 parts of coarse stone powder, 35 parts of fine stone powder, 35.8 parts of cement, 0.18 parts of foaming agent, 0.73 parts of water reducing agent, 1.2 parts of setting accelerator and 29.7 parts of water, calculated by weight.

[0066] The dilution ratio of the foaming agent is 50 times (the mass ratio of the foaming agent to tap water is 1:50), the mass ratio of granite to gneiss in the coarse stone powder is 3:1, and the specific surface area of ​​the coarse stone powder is 150m 2 / kg, the mass ratio of granite to gneiss in the fine stone powder is 3:1, and the specific surface area of ​​the fine stone powder is 430m 2 / kg, the preparation steps are roughly the same as those in Example 1, except that the foaming agent is not pretreated with ultrafine stone powder.

[0067] Comparative Example 3 (the coarse and fine stone powders of the foam concrete in this scheme are both granite stone powder)

[0068] A high-content composite stone powder foam concrete consists of 14.6 parts of coarse stone powder, 35 parts of fine stone powder, 2.2 parts of ultrafine stone powder, 35.8 parts of cement, 0.18 parts of foaming agent, 0.73 parts of water reducing agent, 1.2 parts of setting accelerator and 29.7 parts of water, calculated by weight.

[0069] The dilution ratio of the foaming agent is 50 times (the mass ratio of the foaming agent to tap water is 1:50), the coarse stone powder is all granite stone powder, and the specific surface area of ​​the coarse stone powder is 150m 2 / kg, the fine stone powder is all granite powder, and the specific surface area of ​​the fine stone powder is 430m 2 / kg, the specific surface area of ​​ultrafine stone powder is 7200m 2 / kg, and the preparation steps are the same as those in Example 1.

[0070] Comparative Example 4 (the coarse and fine stone powders of the foam concrete in this scheme are both gneiss stone powder)

[0071] A high-content composite stone powder foam concrete consists of 14.6 parts of coarse stone powder, 35 parts of fine stone powder, 2.2 parts of ultrafine stone powder, 35.8 parts of cement, 0.18 parts of foaming agent, 0.73 parts of water reducing agent, 1.2 parts of setting accelerator and 29.7 parts of water, calculated by weight.

[0072] The dilution ratio of the foaming agent is 50 times (the mass ratio of the foaming agent to tap water is 1:50), the coarse stone powder is all gneiss stone powder, and the specific surface area of ​​the coarse stone powder is 150m 2 / kg, the fine stone powder is all gneiss rock powder, and the specific surface area of ​​the fine stone powder is 430m 2 / kg, the specific surface area of ​​ultrafine stone powder is 7200m 2 / kg, and the preparation steps are the same as those in Example 1.

[0073] After curing for 28 days, the high-content composite stone powder foam concrete was tested for dry density, thermal conductivity, compressive strength, and water absorption according to JG / T 266-2011, "Foamed Concrete," and GB / T 10294-2008, "Insulating Materials - Determination of Steady-State Thermal Resistance and Related Properties - Guarded Hot Plate Method." The performance test results of the high-content composite stone powder foam concrete obtained in the Examples and Comparative Examples are shown in the table below.

[0074]

[0075] From the dry density data, we can see that among the seven groups of foam concrete, the control examples 2 and 4 cannot be formed, and the dry density of the other five groups of foam concrete ranges from 446 to 578 kg / m 3 The stone powder foam concrete of control example 2 cannot be formed, mainly because the quality of the foaming agent is poor. The foaming agent has not been treated with ultra-fine stone powder, resulting in the bubbles it produces being unstable. When poured into the mold for curing and hardening, the foam gradually breaks down ( Figure 4 The stone powder foam concrete of comparative example 4 could not be formed, mainly because the coarse and fine stone powders were both gneiss. The flaky particle shape of the gneiss stone powder was not conducive to the fluidity of the foam concrete, resulting in poor uniformity of the foam concrete after mixing. As a result, the foam of the foam concrete gradually broke during the curing and hardening process, and it could not be formed. ( Figure 5 ).

[0076] From the thermal conductivity data, it can be seen that the thermal conductivity of the embodiment is lower than that of the comparative examples 1 and 3 in the formed foam concrete. The thermal conductivity of foam concrete is related to its dry density and pore structure (pore connectivity, pore shape, etc.). Under normal circumstances, the lower the dry density and the fewer the connected pores, the lower the thermal conductivity. The thermal conductivity of embodiment 2 is significantly lower than that of comparative examples 1 and 3, which may be because embodiment 2 ( Figure 6 ) has fewer interconnected pores, while the control examples 1 and 3 ( Figure 7 、 Figure 8) has more connected pores in its pore structure, which shows that both the external addition of coarse stone powder with appropriate particle size and the composite stone powder addition process can improve the uniformity of the pore structure of high-content composite stone powder foam concrete, and its foam concrete contains fewer connected pores.

[0077] The compressive strength data show that the compressive strength of the foamed concrete in Example 2 is significantly superior to that of Comparative Examples 1 and 3, demonstrating its high strength. The mechanical properties of Example 2 are also significantly improved compared to Comparative Examples 1 and 3, demonstrating that both the addition of coarse stone powder of appropriate particle size and the composite stone powder addition process can improve the mechanical properties of foamed concrete with high composite stone powder content.

[0078] It can be seen from the water absorption data that the water absorption of the molded foamed concrete in the embodiment is significantly lower than that in the control examples 1 and 3, indicating that the addition of coarse stone powder of appropriate particle size and the composite stone powder process improve the density of the foamed concrete (the number of connected pores in the pore structure is reduced and the number of non-connected pores is increased), thereby suppressing the water absorption of the foamed concrete with a high content of composite stone powder.

[0079] The above description is only a preferred embodiment of the present invention. All equivalent changes and modifications made according to the scope of the patent application of the present invention should fall within the scope of the present invention.

Claims

1. A method for preparing high-content composite stone powder foam concrete, characterized in that: The following steps are involved: 1) Measure the materials of each group according to the mass ratio and set aside for use; The foam concrete preparation materials are as follows: 10-20 parts of coarse stone powder, 30-40 parts of fine stone powder, 2-3 parts of ultrafine stone powder, 30-40 parts of cement, 0.16-0.2 parts of foaming agent, 0.4-1 parts of water reducing agent, 0.8-1.5 parts of coagulant and 25-35 parts of water; the specific surface area of ​​the coarse stone powder is 50-300m 2 / kg; the specific surface area of ​​the fine stone powder is 300~600m 2 / kg; the specific surface area of ​​the ultrafine stone powder is 5000~9000m 2 / kg; The lithology of the coarse stone powder is granite and gneiss, and the mass ratio of granite to gneiss in the stone powder is 0.5~4:1; The lithology of fine stone powder is granite and gneiss, and the mass ratio of granite to gneiss in the stone powder is 1~4:1; The lithology of ultrafine stone powder is granite; The foaming agent is LG-2258 cement foaming agent; The water reducer is a naphthalene-based water reducer; The coagulant is anhydrous calcium chloride; The water is tap water, with chloride ≤ 250 mg / L, sulfate ≤ 250 mg / L, and total dissolved solids ≤ 1000 mg / L; 2) Dissolve the coagulant completely in tap water and wait for the mixture of water and coagulant to cool to room temperature before use; 3) Dilute the foaming agent with tap water at a dilution ratio of 40 to 60 times, add the ultrafine stone powder into the diluted foaming agent, and stir in a magnetic stirrer for 5 to 10 minutes to obtain the foam liquid to be used; 4) Add coarse stone powder, fine stone powder and cement into the mortar mixing pot and stir at a speed of 140±5r / min for 2 minutes to prepare a mixed dry material. Then add the mixture of water and coagulant into the mortar mixing pot and stir at a speed of 140±5r / min for 1.5 minutes to prepare a mixed slurry. 5) The prepared foam liquid is passed through a foaming machine to obtain uniform foam, and the foam is added to the mixed slurry. Stir at a speed of 140±5r / min for 1 minute, then remove the mixing pot and use a tool to scrape the material remaining on the pot wall and bottom; return the mixing pot and continue stirring at a speed of 140±5r / min for 1-2 minutes to ensure that the foam is evenly dispersed in the mixed slurry. When the final mixture has a creamy, easy-to-cast fluid consistency, a high-content composite stone powder foam concrete slurry is obtained; 6) The resulting creamy foamed concrete slurry was injection molded, covered with polyethylene film, and placed in an environment at a temperature of 23±2°C and a relative humidity of 65±15% until it hardened and then demolded. After demolding, it was placed in an environment at a temperature of 20±2°C and a relative humidity of greater than 95% and cured for 28 days to prepare a high-content composite stone powder foamed concrete.

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