Steam-curing aerated concrete admixture as well as preparation method and application thereof
By combining polyoxyethylene laurate, lithium sulfate, triethanolamine, sodium thiocyanate, and polycarboxylate superplasticizer in specific proportions as an admixture for autoclaved aerated concrete, the problem of high production cost of autoclaved aerated concrete blocks is solved, achieving cost reduction and shortening of process cycle, while maintaining the physical properties of concrete.
Patent Information
- Application Number
- CN202511603837.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-11-05
- Publication Date
- 2026-01-13
AI Technical Summary
The production cost of autoclaved aerated concrete blocks is high and the process cycle is long, making it difficult to meet the economic value requirements.
By using a specific ratio of components such as polyoxyethylene laurate, lithium sulfate, triethanolamine, sodium thiocyanate, and polycarboxylate superplasticizer, this admixture for autoclaved aerated concrete significantly reduces the amount of cement and lime used, and ensures uniform dispersion of the components by optimizing the mixing speed and time.
It significantly reduces the production cost of autoclaved aerated concrete blocks, increases their economic value, shortens the curing time, and maintains the physical properties of the concrete.
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Abstract
Description
Technical Field
[0001] This invention relates to the field of concrete admixtures, and in particular to an admixture for steam-cured aerated concrete, its preparation method, and its application. Background Technology
[0002] Autoclaved aerated concrete (AAC) blocks are porous concrete products made from cement, lime, slag, sand, fly ash, foaming agent, bubble stabilizer, and regulator as main raw materials. They are manufactured through processes such as grinding, metering, mixing and pouring, foaming and expansion, static curing, cutting, autoclaving, and finished product processing. They are mainly suitable for frame structures, external wall filling of cast-in-place concrete, and internal wall partitions. They can also be used for external walls of multi-story buildings with seismic ring beam structures or thermal insulation composite walls, and can also be used for thermal insulation of building roofs.
[0003] Although autoclaved aerated concrete (AAC) blocks have good performance, their production cost is also relatively high. The production process requires high oxygen evaporation temperature (50℃-70℃) and high pressure (generally reaching 1.2MPa), and the production cycle is 8-14 hours. As a result, the economic value of autoclaved aerated concrete (AAC) blocks is difficult to meet the demand, so there is still room for improvement. Summary of the Invention
[0004] In order to reduce the production cost of autoclaved aerated concrete (AAC) blocks and improve their economic value, this application provides an admixture for autoclaved aerated concrete, its preparation method, and its application.
[0005] In a first aspect, this application provides an admixture for autoclaved aerated concrete, employing the following technical solution: An admixture for steam-cured aerated concrete comprises the following components in parts by weight: 12-15 parts of polyoxyethylene laurate; 5-8 parts of lithium sulfate; 20-25 parts of triethanolamine; 4-7 parts sodium thiocyanate; 5-10 parts water-reducing agent; Solvent 40-60 parts.
[0006] By adopting the above technical solution, and by using polyoxyethylene laurate, lithium sulfate, triethanolamine, and sodium thiocyanate in a specific ratio, the addition of admixtures to concrete can significantly reduce the total amount of cement and lime used without significantly reducing the strength. This significantly reduces the cost of raw materials and better meets the requirements for low carbon emissions. At the same time, it can also shorten the curing time and improve production efficiency, resulting in a significant reduction in the production cost of autoclaved aerated concrete (AAC) blocks and giving them higher economic value.
[0007] Preferably, the water-reducing agent is a polycarboxylate water-reducing agent.
[0008] By adopting the above technical solution and adding polycarboxylate superplasticizer, the production process difficulty of autoclaved aerated concrete (AAC) blocks can be further reduced.
[0009] Preferably, the solvent is water.
[0010] By adopting the above technical solution and specifically selecting water as the solvent, the components can be fully dissolved in the solvent, thereby making the autoclaved aerated concrete admixture more stable and the product quality better.
[0011] Preferably, the mass ratio of polyoxyethylene laurate, lithium sulfate, triethanolamine, and sodium thiocyanate is 13:7:22:6.
[0012] By adopting the above technical solution and specifically selecting the mass ratio of polyoxyethylene laurate, lithium sulfate, triethanolamine, and sodium thiocyanate, the admixture can better improve the effect of aerated concrete, reduce cement usage, and achieve more significant cost reduction and efficiency improvement.
[0013] Secondly, this application provides a method for preparing an admixture for autoclaved aerated concrete, employing the following technical solution: A method for preparing the above-mentioned autoclaved aerated concrete admixture includes the following steps: Step 1), mix polyoxyethylene laurate, lithium sulfate, triethanolamine, sodium thiocyanate and solvent evenly to obtain a premix; Step 2) Add the water-reducing agent to the premix and mix evenly to obtain the admixture for steam-cured aerated concrete.
[0014] By adopting the above technical solution, the core components can be better dispersed and evenly mixed before adding the water-reducing agent, which is achieved by first mixing polyoxyethylene laurate, lithium sulfate, triethanolamine, sodium thiocyanate, and solvent. This results in a better effect of reducing cement usage in autoclaved aerated concrete admixtures.
[0015] Preferably, in step 1), the stirring speed is 60-80 r / min and the stirring is carried out at room temperature for 10-15 min; in step 2), the stirring speed is 45-55 r / min and the stirring is carried out at room temperature for 5-10 min.
[0016] By adopting the above technical solution and using a special stirring speed and time combination, it is possible to better ensure the uniform dispersion of each component, guarantee stable product quality, reduce energy and time waste, and have higher economic value.
[0017] Thirdly, this application provides an application of an admixture for autoclaved aerated concrete, employing the following technical solution: An application of the above-mentioned autoclaved aerated concrete admixture, wherein the autoclaved aerated concrete admixture is added to the aerated concrete formulation for the preparation of autoclaved aerated concrete.
[0018] By adopting the above technical solutions, the autoclaved aerated concrete produced can maintain good performance while significantly reducing the amount of cement used, which can significantly reduce the production cost of autoclaved aerated concrete and significantly improve its economic value.
[0019] Preferably, the mass content of the autoclaved aerated concrete admixture in the aerated concrete formula is 0.01%-0.02%.
[0020] By adopting the above technical solution, the amount of cement used in concrete can be significantly reduced by adding a small amount of autoclaved aerated concrete admixture. The cost of using autoclaved aerated concrete admixture is low, which can more significantly reduce the production cost of autoclaved aerated concrete.
[0021] In summary, this application has the following beneficial effects: 1. Because this application uses polyoxyethylene laurate, lithium sulfate, triethanolamine, and sodium thiocyanate in a specific ratio, the addition of admixtures to concrete can significantly reduce the total amount of cement and lime used without significantly reducing the strength. This significantly reduces the cost of raw materials and better meets the requirements for low carbon emissions. At the same time, it can also shorten the curing time and improve production efficiency, resulting in a significant reduction in the production cost of autoclaved aerated concrete (AAC) blocks and thus higher economic value.
[0022] 2. In this application, by specifically selecting the mass ratio of polyoxyethylene laurate, lithium sulfate, triethanolamine, and sodium thiocyanate, the admixture can better improve the effect of aerated concrete, reduce cement usage, and achieve more significant cost reduction and efficiency improvement.
[0023] 3. In this application, water is preferably selected as the solvent, so that each component can be fully dissolved in the solvent, thereby making the autoclaved aerated concrete admixture more stable and the product quality better. Detailed Implementation
[0024] The present application will be further described in detail below with reference to the embodiments. Example 1
[0025] An admixture for steam-cured aerated concrete, the preparation method of which includes the following steps: Step 1): Add 12 kg of polyoxyethylene laurate, 5 kg of lithium sulfate, 20 kg of triethanolamine, 4 kg of sodium thiocyanate, and 40 kg of water into a mixing tank. Stir at 60 r / min for 10 min at room temperature to obtain a premix.
[0026] Step 2) Add 5 kg of polycarboxylate superplasticizer to the premix, stir at a speed of 45 r / min, and stir at room temperature for 5 min to obtain the autoclaved aerated concrete admixture.
[0027] The polyoxyethylene laurate is commercially available and contains 99% laurate.
[0028] Triethanolamine was sourced from commercially available sources and contained 99% purity.
[0029] Sodium thiocyanate is commercially available and has a purity of 99%.
[0030] Lithium sulfate was prepared in-house using the following method: Step 01), mix lepidolite and limestone in a mass ratio of 1:3, and crush the mixture in a ball mill to K±2% to obtain a mixture; Step 02): The mixture is fed into a rotary kiln and calcined at 1000℃ for 40 minutes to obtain the pretreated material.
[0031] Step 03): Mix the pretreated material with deionized water at a mass ratio of 1:5, stir at 60 r / min for 30 min, filter, take the filtrate, heat and concentrate the filtrate to a paste, and dry at 110℃ to obtain lithium sulfate.
[0032] The polycarboxylate superplasticizer was prepared in-house, and the preparation method is as follows: Step 001): Mix 300g of water, 340g of methoxy polyethylene glycol (molecular weight 4000-4500), and 2g of sodium hypophosphite evenly to obtain the base material.
[0033] Step 002): Mix 30g of water and 15g of red acid evenly to obtain material A.
[0034] Step 003): Mix 0.4g of sodium dioctyl succinate sulfonate, 2g of sodium hypophosphite, and 60g of water evenly to obtain material B.
[0035] Step 004): Mix 70g of water and 0.72g of carboxyethanol evenly to obtain material C.
[0036] Step 005): 640g of the base material is put into a four-necked flask, heated and kept at a constant temperature of 14°C. At the same time, 45g of component A, 63g of component B, and 70g of component C are added dropwise to the base material at a constant rate. The addition time of component A is 45min, the addition time of component B is 55min, and the addition time of component C is 45min. After all the components are added, the mixture is kept at 33°C for 60min and then cooled naturally to obtain polycarboxylate early-strength water-reducing agent. Example 2
[0037] An admixture for steam-cured aerated concrete, the preparation method of which includes the following steps: Step 1): Add 13 kg of polyoxyethylene laurate, 7 kg of lithium sulfate, 22 kg of triethanolamine, 6 kg of sodium thiocyanate, and 50 kg of water to a mixing tank. Stir at 70 r / min for 135 min at room temperature to obtain a premix.
[0038] Step 2) Add 8 kg of polycarboxylate superplasticizer to the premix, stir at 50 r / min, and stir at room temperature for 8 min to obtain the autoclaved aerated concrete admixture.
[0039] The polyoxyethylene laurate is commercially available and contains 99% laurate.
[0040] Triethanolamine was sourced from commercially available sources and contained 99% purity.
[0041] Sodium thiocyanate is commercially available and has a purity of 99%.
[0042] Lithium sulfate was prepared in-house using the following method: Step 01), mix lepidolite and limestone in a mass ratio of 1:3, and crush the mixture in a ball mill to K±2% to obtain a mixture; Step 02): The mixture is fed into a rotary kiln and calcined at 1000℃ for 40 minutes to obtain the pretreated material.
[0043] Step 03): Mix the pretreated material with deionized water at a mass ratio of 1:5, stir at 60 r / min for 30 min, filter, take the filtrate, heat and concentrate the filtrate to a paste, and dry at 110℃ to obtain lithium sulfate.
[0044] The polycarboxylate superplasticizer was prepared in-house, and the preparation method is as follows: Step 001): Mix 300g of water, 340g of methoxy polyethylene glycol (molecular weight 4000-4500), and 2g of sodium hypophosphite evenly to obtain the base material.
[0045] Step 002): Mix 30g of water and 15g of red acid evenly to obtain material A.
[0046] Step 003): Mix 0.4g of sodium dioctyl succinate sulfonate, 2g of sodium hypophosphite, and 60g of water evenly to obtain material B.
[0047] Step 004): Mix 70g of water and 0.72g of carboxyethanol evenly to obtain material C.
[0048] Step 005): 640g of the base material is put into a four-necked flask, heated and kept at a constant temperature of 14°C. At the same time, 45g of component A, 63g of component B, and 70g of component C are added dropwise to the base material at a constant rate. The addition time of component A is 45min, the addition time of component B is 55min, and the addition time of component C is 45min. After all the components are added, the mixture is kept at 33°C for 60min and then cooled naturally to obtain polycarboxylate early-strength water-reducing agent. Example 3
[0049] An admixture for steam-cured aerated concrete, the preparation method of which includes the following steps: Step 1): Add 15 kg of polyoxyethylene laurate, 8 kg of lithium sulfate, 25 kg of triethanolamine, 7 kg of sodium thiocyanate, and 60 kg of water to a mixing tank. Stir at 80 r / min for 15 min at room temperature to obtain a premix.
[0050] Step 2) Add 10 kg of polycarboxylate superplasticizer to the premix, stir at 55 r / min, and stir at room temperature for 10 min to obtain the autoclaved aerated concrete admixture.
[0051] The polyoxyethylene laurate is commercially available and contains 99% laurate.
[0052] Triethanolamine was sourced from commercially available sources and contained 99% purity.
[0053] Sodium thiocyanate is commercially available and has a purity of 99%.
[0054] Lithium sulfate was prepared in-house using the following method: Step 01), mix lepidolite and limestone in a mass ratio of 1:3, and crush the mixture in a ball mill to K±2% to obtain a mixture; Step 02): The mixture is fed into a rotary kiln and calcined at 1000℃ for 40 minutes to obtain the pretreated material.
[0055] Step 03): Mix the pretreated material with deionized water at a mass ratio of 1:5, stir at 60 r / min for 30 min, filter, take the filtrate, heat and concentrate the filtrate to a paste, and dry at 110℃ to obtain lithium sulfate.
[0056] The polycarboxylate superplasticizer was prepared in-house, and the preparation method is as follows: Step 001): Mix 300g of water, 340g of methoxy polyethylene glycol (molecular weight 4000-4500), and 2g of sodium hypophosphite evenly to obtain the base material.
[0057] Step 002): Mix 30g of water and 15g of red acid evenly to obtain material A.
[0058] Step 003): Mix 0.4g of sodium dioctyl succinate sulfonate, 2g of sodium hypophosphite, and 60g of water evenly to obtain material B.
[0059] Step 004): Mix 70g of water and 0.72g of carboxyethanol evenly to obtain material C.
[0060] Step 005): 640g of the base material is put into a four-necked flask, heated and kept at a constant temperature of 14°C. At the same time, 45g of component A, 63g of component B, and 70g of component C are added dropwise to the base material at a constant rate. The addition time of component A is 45min, the addition time of component B is 55min, and the addition time of component C is 45min. After all the components are added, the mixture is kept at 33°C for 60min and then cooled naturally to obtain polycarboxylate early-strength water-reducing agent.
[0061] Comparative Example 1 An admixture for steam-cured aerated concrete, which differs from Example 2 only in that: Urea was used to replace polyoxyethylene laurate in equal amounts.
[0062] The urea is commercially available and has a purity of 99%.
[0063] Comparative Example 2 An admixture for steam-cured aerated concrete, which differs from Example 2 only in that: Lithium sulfate was replaced with an equal amount of calcium formate.
[0064] Calcium formate is commercially available and has a purity of 99%.
[0065] Comparative Example 3 An admixture for steam-cured aerated concrete, which differs from Example 2 only in that: Triethanolamine was replaced with an equal amount of triisopropanolamine.
[0066] Triisopropanolamine is commercially available and contains 99% purity.
[0067] Comparative Example 4 An admixture for steam-cured aerated concrete, which differs from Example 2 only in that: Sodium thiocyanate was replaced with an equal amount of sodium nitrite.
[0068] The sodium nitrite was sourced commercially and contained 99% sodium nitrite.
[0069] Comparative Example 5 An admixture for steam-cured aerated concrete, which differs from Example 2 only in that: Urea was used to replace polyoxyethylene laurate in equal amounts, calcium formate was used to replace lithium sulfate in equal amounts, triisopropanolamine was used to replace triethanolamine in equal amounts, and sodium nitrite was used to replace sodium thiocyanate in equal amounts.
[0070] The urea is commercially available and has a purity of 99%.
[0071] Calcium formate is commercially available and has a purity of 99%.
[0072] Triisopropanolamine is commercially available and contains 99% purity.
[0073] The sodium nitrite was sourced commercially and contained 99% sodium nitrite.
[0074] Application Example 1 A method for preparing autoclaved aerated concrete is as follows: Step 1): Mix 320kg cement, 200kg lime, 2700kg sand slurry, 1000kg mud slurry, 37kg aluminum powder, 1750kg water, and 1kg autoclaved aerated concrete admixture evenly, pour the mixture into a mold, let it stand to dry, demold, and form a blank.
[0075] Step 2) The preform is sent into a steam curing tank and steamed at 1.2 MPa and 60℃ for 7 hours, then naturally cooled to obtain steam-cured aerated concrete.
[0076] The cement is commercially available, ordinary Portland cement, specification: PO 42.5.
[0077] The lime is slaked lime, sourced from commercially available sources, with a content of 99%.
[0078] The sand slurry is made by mixing river sand, tailings sand and water in a mass ratio of 2:1:0.6.
[0079] The mud is made by mixing granite powder and water in a 3:1 mass ratio.
[0080] The aluminum powder is commercially available, 200 mesh.
[0081] The admixture for autoclaved aerated concrete is the admixture for autoclaved aerated concrete in Example 1.
[0082] Application Example 2 A type of steam-cured aerated concrete differs from application example 1 only in that: The admixture for autoclaved aerated concrete is the admixture for autoclaved aerated concrete in Example 2.
[0083] Application Example 3 A type of steam-cured aerated concrete differs from application example 1 only in that: The admixture for autoclaved aerated concrete is the admixture for autoclaved aerated concrete in Example 4.
[0084] Comparative Application Example 1 A type of steam-cured aerated concrete differs from application example 1 only in that: The admixture for autoclaved aerated concrete is the same as that in Comparative Example 1.
[0085] Comparative Application Example 2 A type of steam-cured aerated concrete differs from application example 1 only in that: The admixture for autoclaved aerated concrete is the same as that in Comparative Example 2.
[0086] Comparative Application Example 3 A type of steam-cured aerated concrete differs from application example 1 only in that: The admixture for autoclaved aerated concrete is the same as that in Comparative Example 3.
[0087] Comparative Application Example 4 A type of steam-cured aerated concrete differs from application example 1 only in that: The admixture for autoclaved aerated concrete is the admixture for autoclaved aerated concrete in Comparative Example 4.
[0088] Comparative Application Example 5 A type of steam-cured aerated concrete differs from application example 1 only in that: The admixture for autoclaved aerated concrete is the autoclaved aerated concrete admixture of Comparative Example 5.
[0089] Blank comparison example A method for preparing autoclaved aerated concrete is as follows: Step 1): Mix 420kg cement, 180kg lime, 2400kg sand slurry, 1000kg mud slurry, 37kg aluminum powder, and 2080kg water evenly, pour the mixture into a mold, let it stand to dry, demold, and form a blank.
[0090] Step 2) The preform is sent into a steam curing tank and steamed at 1.2 MPa and 60℃ for 9 hours, then naturally cooled to obtain steam-cured aerated concrete.
[0091] The cement is commercially available, ordinary Portland cement, specification: PO 42.5.
[0092] The lime is slaked lime, sourced from commercially available sources, with a content of 99%.
[0093] The sand slurry is made by mixing river sand, tailings sand and water in a mass ratio of 2:1:0.6.
[0094] The mud is made by mixing granite powder and water in a 3:1 mass ratio.
[0095] The aluminum powder is commercially available, 200 mesh.
[0096] The admixture for autoclaved aerated concrete is the admixture for autoclaved aerated concrete in Example 1.
[0097] Experiment 1 The compressive strength and dry density of autoclaved aerated concrete samples were tested according to GB / T 11969-2020 "Test Methods for Performance of Autoclaved Aerated Concrete", including application examples, comparative application examples, and blank control examples. Detailed experimental data are shown in Table 1.
[0098] Table 1
[0099] According to the data in Table 1, under the same dry density, the compressive strength of Application Example 1-3 is significantly improved compared to the control example 1-5, and is higher than that of the blank control example. It can be seen that after adding the autoclaved aerated concrete admixture of the embodiment, Application Example 1-3 can obtain higher physical properties compared to the blank control example after a significant reduction in the total amount of cement + lime. On the other hand, after adding the comparative autoclaved aerated concrete admixture of the embodiment, the physical properties of the control example show a significant decrease compared to the blank control example after a significant reduction in the total amount of cement + lime.
[0100] The examples demonstrate that the autoclaved aerated concrete admixture can help reduce the total amount of cement and lime used in autoclaved concrete, thereby effectively reducing costs. Furthermore, the autoclaving time in Examples 1-3 is significantly shorter than that in the control examples. It is evident that the autoclaved aerated concrete admixture in these examples can help shorten the process cycle, and its cost reduction and efficiency improvement effects are particularly significant.
[0101] This specific embodiment is merely an explanation of this application and is not intended to limit it. After reading this specification, those skilled in the art can make modifications to this embodiment without contributing any inventive step, but such modifications are protected by patent law as long as they fall within the scope of the claims of this application.
Claims
1. An admixture for steam-cured aerated concrete, characterized in that: The components include the following parts by mass: 12-15 parts of polyoxyethylene laurate; 5-8 parts of lithium sulfate; 20-25 parts of triethanolamine; 4-7 parts sodium thiocyanate; 5-10 parts of water-reducing agent; Solvent 40-60 parts.
2. The admixture for autoclaved aerated concrete according to claim 1, characterized in that: The water-reducing agent is a polycarboxylate water-reducing agent.
3. The admixture for autoclaved aerated concrete according to claim 2, characterized in that: The solvent is water.
4. The admixture for autoclaved aerated concrete according to claim 3, characterized in that: The mass ratio of polyoxyethylene laurate, lithium sulfate, triethanolamine, and sodium thiocyanate is 13:7:22:
6.
5. A method for preparing an admixture for autoclaved aerated concrete according to any one of claims 1-4, characterized in that: Includes the following steps: Step 1), mix polyoxyethylene laurate, lithium sulfate, triethanolamine, sodium thiocyanate and solvent evenly to obtain a premix; Step 2) Add the water-reducing agent to the premix and mix evenly to obtain the admixture for steam-cured aerated concrete.
6. The method for preparing an admixture for autoclaved aerated concrete according to claim 5, characterized in that: In step 1), the stirring speed is 60-80 r / min, and the stirring is carried out at room temperature for 10-15 min. In step 2), the stirring speed is 45-55 r / min, and the stirring is carried out at room temperature for 5-10 min.
7. An application of the autoclaved aerated concrete admixture according to any one of claims 1-4, characterized in that: The autoclaved aerated concrete admixture is added to the aerated concrete formula to prepare autoclaved aerated concrete.
8. The application of the autoclaved aerated concrete admixture according to claim 7, characterized in that: The mass content of the autoclaved aerated concrete admixture in the aerated concrete formula is 0.01%-0.02%.