Preparation method of efficient composite additive for autoclaved aerated concrete production

Abstract

The invention discloses a preparation method of an efficient composite additive for autoclaved aerated concrete production, and belongs to the technical field of building materials. The efficient composite additive is prepared from the following components: a naphthalene water reducer, a silicone amide foam stabilizer, a polypropylene fiber reinforcing agent, a thickening agent compounded by inorganic kaolin and organic polyvinyl alcohol, a triethanolamine early strength agent and a waterproof agent compounded by silicone zirconium-stearic acid and polyethyl hydroxyl siloxane. And preparing into slurry. According to the efficient composite additive, the production performance and the product quality of autoclaved aerated concrete can be remarkably improved through reasonable proportioning of all the components, the preparation method of the efficient composite additive is simple and easy to operate, all the components are common materials, the cost is low, and in practical application, the efficient composite additive has good application prospects. The high-efficiency composite additive only needs to be added into the production process of autoclaved aerated concrete, so that the stability, the gas forming effect and the product performance of slurry can be remarkably improved, and the high-efficiency composite additive has a wide application prospect.

Description

Technical Field

[0001] This invention belongs to the field of building materials, and specifically relates to a method for preparing a high-efficiency composite additive for the production of autoclaved aerated concrete. Background Technology

[0002] Autoclaved aerated concrete (AAC) has been widely used in the construction industry due to its excellent properties such as light weight, heat insulation, sound insulation, and fire resistance. However, under the background of my country's "carbon neutrality" policy, the traditional AAC production process still faces significant problems of high carbon emissions and high energy consumption. How to achieve energy conservation and carbon reduction in the production process is a key issue that the industry urgently needs to solve. Currently, the siliceous materials used in AAC production are generally recycled solid waste materials. Due to their complex physical properties, these materials are prone to unstable product quality. At the same time, many process problems such as unstable slurry viscosity, poor gas generation effect, and high production energy consumption also result in low product yield and poor production efficiency. Therefore, developing an additive that can improve the production performance of AAC is of great significance. Patent CN201510430881.5 discloses a composite foam stabilizer for AAC and its preparation method, which uses ceramic polishing waste as a carrier and combines the reaction products of triethanolamine and oleic acid to improve the foam stabilization effect. However, the patent imposes certain quality requirements on ceramic polishing waste, which are difficult to obtain in practical applications. Pre-treatment of the waste is often necessary to meet these requirements, increasing cost and process complexity. Furthermore, the ratio and reaction degree of triethanolamine and oleic acid, the characteristics and dosage of ceramic polishing waste, and the type and dosage of suspending agents all present significant challenges for process control in actual production. Patent CN201210018763.X discloses a method for preparing a special mortar additive for autoclaved aerated concrete (AAC). This additive allows for rapid preparation of reliable, low-cost, and easily applied AAC mortars with good adhesion and suitable for on-site preparation of different strength grades. However, using this additive to prepare mortar requires specific construction conditions and procedures. For example, the mixing steps must be precise; water and the additive must be mixed to form a slurry before adding cement and sand. The water content in the mix design is specific to dry sand, and the moisture content of the sand on-site can affect mortar performance. This can be difficult to control precisely in actual construction, leading to unstable mortar quality. This invention uses a variety of materials to form a uniform gel paste, which can be directly added to the mixing stage of concrete preparation. A small amount can achieve a comprehensive improvement in product quality, and it has a very high application prospect. Summary of the Invention

[0003] To address the problems in current autoclaved aerated concrete (AAC) production processes, such as unstable product quality due to the complex physical properties of raw materials, unstable slurry viscosity, poor gas generation effect, and high production energy consumption, this invention provides a method for preparing an additive used in the production of autoclaved aerated concrete. By adding this additive during the mixing stage, the stability of the slurry can be improved, the gas generation rate and amount can be controlled and adjusted, the gas generation effect can be optimized, the hardening of the green body can be accelerated, the curing time can be greatly shortened, the production energy consumption can be reduced, and the product quality and yield can be improved.

[0004] The additive of this invention is mainly composed of the following components (by weight percentage): 5%-15% naphthalene-based water-reducing agent, 3%-10% silicone amide foam stabilizer, 10%-25% polypropylene fiber reinforcing agent, 5%-10% thickener, 5%-20% triethanolamine early strength agent, 5%-15% waterproofing agent, and deionized water and glycerin as solvents: 3%-25% deionized water and 5%-37.5% glycerin.

[0005] The preparation method includes the following steps:

[0006] Step 1: Weigh out the solid components in the composition, including: naphthalene-based water-reducing agent, polypropylene fiber, inorganic kaolin in the thickener, and silicone zirconium-stearic acid in the waterproofing agent, in proportion, and perform preliminary dry mixing of the solid components until they are evenly mixed to form a solid mixture.

[0007] Step 2: The solid mixture is subjected to solid-phase grinding and initially passed through a 200-mesh sieve to achieve a particle size of 500nm-2000nm. 10-50 mL of glycerol is added during the grinding process.

[0008] Step 3: Disperse the other liquid components in the composition, including: silicone amide, organic polyvinyl alcohol in the thickener, triethanolamine, polyethyl hydroxysiloxane in the waterproofing agent, deionized water and glycerin in the solvent, and stir for 2-5 hours to form a homogeneous liquid composition;

[0009] Step four: Add the liquid components to the dry-mixed and ground solid mixture, stir until homogeneous, and stir for 2-5 hours.

[0010] Preferably, the thickener is a mixture of inorganic kaolin and organic polyvinyl alcohol, wherein the mixing ratio of inorganic kaolin and organic polyvinyl alcohol is 2:3.

[0011] Preferably, the waterproofing agent is a mixture of zirconium silicone-stearic acid and polyethyl hydroxysiloxane, wherein the mixing ratio of zirconium silicone-stearic acid and polyethyl hydroxysiloxane is 1:5.

[0012] Preferably, the solvent is a mixture of deionized water and glycerin, with a ratio of 2:3.

[0013] Preferably, the high-efficiency composite additive can be applied to the production of autoclaved aerated concrete, which can significantly improve the stability of the slurry, the gas generation effect and the quality performance of the product.

[0014] As a preferred method, the additive is applied in the production of autoclaved aerated concrete as follows: after the raw material slurry preparation process, the additive is further added. The amount of additive does not exceed 30% of the total weight of the raw materials. It can play a role in modifying and regulating the raw materials in the slurry. Other processes can be carried out in accordance with conventional production processes, such as mixing, pouring, curing, cutting and autoclaving. The autoclaving time can be appropriately shortened to 10 hours.

[0015] Based on the above technical solutions and the technical problems solved, the advantages and positive effects of the technical solution to be protected by this invention are as follows:

[0016] 1. Improve slurry stability: The use of high-efficiency composite additives can completely separate siliceous material particles in solid waste tailings, eliminate sticky obstacles in the slurry, and improve the stability of the slurry.

[0017] 2. Optimize gas generation effect: enable aluminum powder particles in aluminum paste to fully contact with calcareous materials in lime and siliceous materials in cement and tailings, and regulate the stability of bubble structure with foam stabilizer to achieve uniform and controllable foaming. This fundamentally solves the influence of the physical properties of solid waste raw materials on gas generation and completely eliminates quality problems caused by gas generation during casting.

[0018] 3. Reduced production energy consumption: During the autoclave curing process, due to the complete and sufficient contact between the calcareous materials in lime and cement and the siliceous materials in tailings, as well as the modification of the calcareous materials by the high-efficiency composite additives, the pressure during autoclave constant pressure can be reduced to 1.2MPa-1.35MPa, the autoclave pressure is reduced by about 10-20%, the curing time is reduced from 12 hours to 8-10 hours, the time cost is reduced by 16.6-32.2%, and the boiler fuel (natural gas, etc.) consumption is reduced by about 8-15%.

[0019] 4. The high-efficiency composite additive prepared by this invention can improve the compressive strength and waterproof performance of autoclaved aerated concrete blocks and panels, while reducing the amount of calcium-based materials used, and has good application prospects. Detailed Implementation

[0020] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0021] To enable those skilled in the art to fully understand how the present invention is specifically implemented, this section provides an explanatory description of the embodiments that expand upon the technical solutions of the claims.

[0022] The present invention relates to a method for preparing a high-efficiency composite additive used in the production of autoclaved aerated concrete, comprising the following steps:

[0023] S101, the solid components in the composition, including: naphthalene-based water-reducing agent, polypropylene fiber, inorganic kaolin in the thickener, and silicone zirconium-stearic acid in the waterproofing agent, are weighed in proportion, and the solid components are initially dry-mixed and mixed evenly to form a solid mixture.

[0024] S102, the solid mixture is subjected to solid-phase grinding and initially passed through a 200-mesh sieve to achieve a particle size of 500nm-2000nm. 10-50 mL of glycerol is added during the grinding process.

[0025] S103, other liquid components in the composition, including: silicone amide, organic polyvinyl alcohol in the thickener, triethanolamine, polyethyl hydroxysiloxane in the waterproofing agent, deionized water and glycerin, are dispersed in a solvent and stirred for 2-5 hours to form a homogeneous liquid composition;

[0026] S104, the liquid component is added to the dry-mixed and ground solid mixture, and stirred evenly for 2-5 hours.

[0027] Furthermore, the thickener is a mixture of inorganic kaolin and organic polyvinyl alcohol, wherein the mixing ratio of inorganic kaolin and organic polyvinyl alcohol is 2:3.

[0028] Furthermore, the waterproofing agent is a mixture of zirconium silicone-stearic acid and polyethyl hydroxysiloxane, wherein the mixing ratio of zirconium silicone-stearic acid and polyethyl hydroxysiloxane is 1:5.

[0029] Furthermore, the solvent is a mixture of deionized water and glycerol, with a ratio of 2:3.

[0030] To make the present invention more fully disclosed, more specific embodiments are described below.

[0031] Example 1

[0032] The high-efficiency composite additive of the present invention is mainly composed of the following components (by weight percentage): 8% naphthalene-based water-reducing agent, 4% silicone amide foam stabilizer, 12% polypropylene fiber reinforcing agent, 3% inorganic kaolin, 4.5% organic polyvinyl alcohol, 15% triethanolamine, 1% silicone zirconium-stearic acid, 5% polyethyl hydroxysiloxane, 19% deionized water, and 28.5% glycerol. The high-efficiency composite additive is then prepared as follows: (1) the solid components of the above components are first passed through a 200-mesh sieve and weighed according to the proportion, and then the solid components are initially mixed evenly; (2) the mixture is subjected to solid-phase grinding so that the particle size reaches 500nm-2000nm, and 20mL of glycerol is added per kilogram of solid during the grinding process; (3) the other liquid components are dispersed in a solvent and stirred for 3h to form a uniform liquid component; (4) the liquid component is added to the solid component after dry mixing and grinding, and stirred for 3h.

[0033] Example 2

[0034] The high-efficiency composite additive of the present invention is mainly composed of the following components (by weight percentage): 10% naphthalene-based water-reducing agent, 6% silicone amide foam stabilizer, 18% polypropylene fiber reinforcing agent, 4% inorganic kaolin, 6% organic polyvinyl alcohol, 6% triethanolamine, 1.5% silicone zirconium-stearic acid, 7.5% polyethyl hydroxysiloxane, 16.4% deionized water, and 24.6% glycerol. The high-efficiency composite additive is then prepared as follows: (1) the solid components of the above components are first passed through a 200-mesh sieve and weighed according to the proportion, and then the solid components are initially mixed evenly; (2) the mixture is subjected to solid-phase grinding so that the particle size reaches 500nm-2000nm, and 10mL of glycerol is added per kilogram of solid during the grinding process; (3) the other liquid components are dispersed in a solvent and stirred for 2 hours to form a uniform liquid component; (4) the liquid component is added to the solid component after dry mixing and grinding, and stirred for 3 hours.

[0035] Example 3

[0036] The high-efficiency composite additive of the present invention is mainly composed of the following components (by weight percentage): 15% naphthalene-based water-reducing agent, 9% silicone amide foam stabilizer, 22% polypropylene fiber reinforcing agent, 4% inorganic kaolin, 6% organic polyvinyl alcohol, 20% triethanolamine, 2% silicone zirconium-stearic acid, 10% polyethyl hydroxysiloxane, 4.8% deionized water, and 7.2% glycerol. The high-efficiency composite additive is then prepared as follows: (1) the solid components of the above components are first passed through a 200-mesh sieve and weighed according to the proportion, and then the solid components are initially mixed evenly; (2) the mixture is subjected to solid-phase grinding so that the particle size reaches 500nm-2000nm, and 50mL of glycerol is added per kilogram of solid during the grinding process; (3) the other liquid components are dispersed in a solvent and stirred for 5h to form a uniform liquid component; (4) the liquid component is added to the solid component after dry mixing and grinding, and stirred for 5h.

[0037] Example 4

[0038] The high-efficiency composite additive of the present invention is mainly composed of the following components (by weight percentage): 10% naphthalene-based water-reducing agent, 3% silicone amide foam stabilizer, 10% polypropylene fiber reinforcing agent, 2% inorganic kaolin, 3% organic polyvinyl alcohol, 5% triethanolamine, 1% silicone zirconium-stearic acid, 5% polyethyl hydroxysiloxane, 24.4% deionized water, and 36.6% glycerol. The high-efficiency composite additive is then prepared as follows: (1) the solid components of the above components are first passed through a 200-mesh sieve and weighed according to the proportion, and then the solid components are initially mixed evenly; (2) the mixture is subjected to solid-phase grinding so that the particle size reaches 500nm-2000nm, and 12mL of glycerol is added per kilogram of solid during the grinding process; (3) the other liquid components are dispersed in a solvent and stirred for 2 hours to form a uniform liquid component; (4) the liquid component is added to the solid component after dry mixing and grinding, and stirred for 2 hours.

[0039] Example 5

[0040] The high-efficiency composite additive of the present invention is mainly composed of the following components (by weight percentage): 12% naphthalene-based water-reducing agent, 7% silicone amide foam stabilizer, 21% polypropylene fiber reinforcing agent, 4% inorganic kaolin, 6% organic polyvinyl alcohol, 10% triethanolamine, 2% silicone zirconium-stearic acid, 10% polyethyl hydroxysiloxane, 11.2% deionized water, and 16.8% glycerol. The high-efficiency composite additive is then prepared as follows: (1) the solid components of the above components are first passed through a 200-mesh sieve and weighed according to the proportion, and then the solid components are initially mixed evenly; (2) the mixture is subjected to solid-phase grinding so that the particle size reaches 500nm-2000nm, and 18mL of glycerol is added per kilogram of solid during the grinding process; (3) the other liquid components are dispersed in a solvent and stirred for 2 hours to form a uniform liquid component; (4) the liquid component is added to the solid component after dry mixing and grinding, and stirred for 3 hours.

[0041] The above demonstrates the inventiveness and technical value of the present invention. The high-efficiency composite additives prepared according to Examples 1-5, when used in the production of autoclaved aerated concrete, can completely separate the siliceous material particles in the solid waste tailings, eliminating viscous obstacles in the slurry and improving its stability. Furthermore, it allows the aluminum powder particles in the aluminum paste to fully contact the calcareous materials in the lime and the siliceous materials in the cement tailings. The foam stabilizer regulates the stability of the bubble structure, achieving uniform and controllable foaming. This fundamentally solves the problem of the influence of the physical properties of the solid waste raw materials on gas generation, completely eliminating the effects of pouring on gas generation. The quality issues caused by gas problems are addressed. Simultaneously, during autoclaving, the complete and thorough contact between the calcareous materials in the lime and the siliceous materials in the tailings, along with the modification of the calcareous materials by high-efficiency composite additives, allows for a reduction in the autoclave's constant pressure to 1.2MPa-1.35MPa, a 10-20% reduction in autoclaving pressure, and a reduction in curing time from 12 hours to 8-10 hours, resulting in a 16.6-32.2% reduction in time costs. This also reduces boiler fuel (natural gas, etc.) consumption by approximately 8-15%, achieving green and low-carbon production of autoclaved aerated concrete. Autoclaved aerated concrete blocks and slabs using high-efficiency composite additives exhibit an 8% increase in compressive strength and a 46% improvement in waterproofing performance, while reducing the amount of calcareous materials used by approximately 3-10%, demonstrating significant application potential.

[0042] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any modifications, equivalent substitutions, and improvements made by those skilled in the art within the scope of the technology disclosed in the present invention, and within the spirit and principles of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A high-efficiency composite additive for the production of autoclaved aerated concrete, characterized in that: The high-efficiency composite additive is mainly composed of the following components (by weight percentage): naphthalene-based water-reducing agent at 5%-15%, silicone amide foam stabilizer at 3%-10%, polypropylene fiber reinforcing agent at 10%-25%, thickener at 5%-10%, triethanolamine early-strength agent at 5%-20%, waterproofing agent at 5%-15%, and solvent: the solvent is composed of deionized water and glycerin, with deionized water at 3%-25% and glycerin at 5%-37.5%. The preparation method of the high-efficiency composite additive includes the following steps: Step 1: Weigh the solid components in the composition, including naphthalene-based water-reducing agent, polypropylene fiber, inorganic kaolin in the thickener, and silicone zirconium-stearic acid in the waterproofing agent, in proportion, and perform preliminary dry mixing of the solid components until they are evenly mixed to form a solid mixture. Step 2: The solid mixture is subjected to solid-phase grinding and initially passed through a 200-mesh sieve to achieve a particle size of 500nm-2000nm. 10-50 mL of glycerol is added during the grinding process. Step 3: Disperse the other liquid components in the composition, including silicone amide, organic polyvinyl alcohol in the thickener, triethanolamine, polyethyl hydroxysiloxane in the waterproofing agent, water and glycerin in the solvent, and stir for 2-5 hours to form a homogeneous liquid composition. Step 4: Add the liquid component to the dry-mixed and ground solid mixture, stir until homogeneous, and stir for 2-5 hours.

2. The high-efficiency composite additive for autoclaved aerated concrete production according to claim 1, characterized in that: The thickener is a mixture of inorganic kaolin and organic polyvinyl alcohol, with a mixing ratio of 2:

3.

3. The high-efficiency composite additive for autoclaved aerated concrete production according to claim 1, characterized in that: The waterproofing agent is a mixture of zirconium silicone-stearic acid and polyethyl hydroxysiloxane, wherein the mixing ratio of zirconium silicone-stearic acid and polyethyl hydroxysiloxane is 1:

5.

4. The high-efficiency composite additive for autoclaved aerated concrete production according to claim 1, characterized in that: The solvent is a mixture of deionized water and glycerin, with a ratio of 2:

3.

5. The high-efficiency composite additive for the production of autoclaved aerated concrete according to claim 1, characterized in that: The high-efficiency composite additive can be applied to the production of autoclaved aerated concrete, and can significantly improve the stability of the slurry, the gas generation effect, and the quality performance of the product.