Autoclaved aerated concrete block and method for manufacturing the same

Abstract

The application relates to the technical field of building material processing, and discloses a steam-pressure aerated concrete block and a preparation method thereof, which are composed of cement 45%, fly ash 25%, gypsum 10%, sand 25%, modifier 3%, high-activity mineral admixture 10%, fiber reinforced material 2%, recycled aggregate 20%, retarder 1% and thickening agent 1%. The high-activity mineral admixture and the additive are selected to effectively improve the mechanical properties of the block, so that the compressive strength of the block reaches 60 MPa, which is 20 MPa higher than that of the prior art, which means that the block can bear greater load and external pressure, and the structural stability and safety of the building are enhanced; meanwhile, the durability of the block reaches 200 cycles, which is 50 cycles more than that of the prior art, and the improvement of the durability means that the block has better stability under long-term use and various environmental conditions, and the service life of the building is prolonged.

Description

Technical Field

[0001] This invention relates to the field of building material processing technology, specifically to an autoclaved aerated concrete block and its preparation method. Background Technology

[0002] In the construction industry, masonry blocks are a common building material used to construct walls and other structures. Current technology has limitations in terms of compressive strength, durability, density, energy efficiency, construction efficiency, environmental friendliness, and cost-effectiveness of masonry blocks.

[0003] In the existing technology, the compressive strength of blocks is usually around 40MPa, the durability is around 150 cycles, the density is around 90%, and the thermal conductivity is 0.3W / m·K.

[0004] However, with the development of the construction industry and the increasing demand for high-performance building materials, there is a need for further improvements in block technology.

[0005] Existing block technologies still have room for improvement in terms of compressive strength, durability, density, energy efficiency, and environmental friendliness. Therefore, a new block technology is needed that can provide higher block strength, better durability, higher density, better energy efficiency, and better environmental friendliness.

[0006] To address the aforementioned technical problems, this invention proposes an improved block technology. By employing specific formulations and processes, it overcomes the limitations of existing technologies in terms of block strength, durability, density, energy efficiency, and environmental friendliness, providing a superior block solution. Summary of the Invention

[0007] To address the shortcomings of existing technologies, this invention provides an autoclaved aerated concrete block and its preparation method, overcoming the problems of existing technologies in terms of block strength, durability, density, energy efficiency, and environmental friendliness.

[0008] To achieve the above objectives, the present invention provides the following technical solution: an autoclaved aerated concrete block and its preparation method, comprising:

[0009] Cement: 35-45%;

[0010] Fly ash: 15-25%;

[0011] Gypsum: 5-10%;

[0012] Sand: 15-25%;

[0013] Modifier: 1-3%;

[0014] Highly active mineral admixtures: 5-10%;

[0015] Fiber-reinforced materials: 0.5-2%;

[0016] Recycled aggregate: 10-20%;

[0017] Retarder: 0.1-1%;

[0018] Thickener: 0.1-1%.

[0019] Preferably, the proportions of the cement, fly ash, gypsum, sand, amendment, highly active mineral admixture, fiber reinforcement, recycled aggregate, retarder, and thickener are 40%:20%:8%:20%:2%:5%:1%:10%:0.3%:0.5%.

[0020] Preferably, the autoclaved aerated concrete block has a compressive strength greater than 60 MPa, a flexural strength greater than 10 MPa, a thermal conductivity less than 0.30 watts / meter·Kelvin, and a water absorption rate of less than 10%.

[0021] Preferably, the fiber reinforcement material is glass fiber or polymer fiber, and the recycled aggregate is recycled construction waste, waste concrete, or waste plastic.

[0022] Preferably, the modifier is one or more of cement water-reducing agents, reinforcing agents, and foaming agents, used to improve the strength, durability, and workability of concrete.

[0023] Preferably, the retarder is one or more of sodium silicate, gluconic acid, and triethanolamine, used to adjust the setting time of the blocks, and the thickener is one or more of hydroxyethyl cellulose, hydroxypropyl methyl cellulose, polyacrylamide, and polyether polyurethane, used to improve the viscosity and fluidity of the block mortar.

[0024] Preferably, a method for preparing autoclaved aerated concrete blocks includes the following steps:

[0025] S1. Mix cement, fly ash, gypsum and sand evenly;

[0026] S2. Add the modifier to the mixture and stir thoroughly to disperse it evenly;

[0027] S3. Add an appropriate amount of water to form a uniform block mortar;

[0028] S4. Add highly active mineral admixtures and stir thoroughly again.

[0029] S5. Add fiber-reinforced materials and recycled aggregates, and mix thoroughly;

[0030] S6. Add retarder and thickener, and stir thoroughly;

[0031] S7. Pour the slurry into the mold and vibrate it to fully fill the mold;

[0032] S8. Place the mold into an automated autoclave for steam heating at a temperature of 180-200 degrees Celsius and apply an autoclave pressure of 2-3 MPa.

[0033] S9. The autoclaved blocks are then naturally cured to obtain finished concrete blocks.

[0034] Preferably, the natural curing time for the blocks is 24-48 hours, the relative humidity is maintained between 80-90%, and the temperature is maintained between 20-30 degrees Celsius.

[0035] This invention provides an autoclaved aerated concrete block and its preparation method. It has the following beneficial effects:

[0036] 1. By selecting highly active mineral admixtures and additives, this invention effectively improves the mechanical properties of the blocks, enabling the blocks to achieve a compressive strength of 60 MPa, which is 20 MPa higher than the prior art. This means that the blocks using this invention can withstand greater loads and external pressures, enhancing the structural stability and safety of buildings. At the same time, the durability of the blocks reaches 200 cycles, 50 cycles more than the prior art. The improved durability means that the blocks have better stability under long-term use and various environmental conditions, extending the life of buildings.

[0037] 2. This invention replaces part of the cement with fly ash, reducing the thermal conductivity and carbon emissions of the blocks, thus minimizing negative environmental impacts. The resulting blocks have a thermal conductivity of 0.2 W / m·K, which is 0.1 W / m·K lower than existing technologies. This lower thermal conductivity means the blocks have better insulation properties, reducing energy transfer and heat loss in buildings and improving energy efficiency.

[0038] 3. This invention utilizes recycled materials, such as waste concrete and waste bricks, as one of the raw materials for building blocks. This not only reduces the demand for raw materials but also effectively solves the problem of waste disposal and reduces carbon emissions by 30%. This helps reduce the consumption of natural resources and environmental pollution, meeting the requirements of sustainable development. Detailed Implementation

[0039] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0040] Example 1:

[0041] This invention provides an autoclaved aerated concrete block, comprising:

[0042] Cement: 35-45%;

[0043] Fly ash: 15-25%;

[0044] Gypsum: 5-10%;

[0045] Sand: 15-25%;

[0046] Modifier: 1-3%;

[0047] Highly active mineral admixtures: 5-10%;

[0048] Fiber-reinforced materials: 0.5-2%;

[0049] Recycled aggregate: 10-20%;

[0050] Retarder: 0.1-1%;

[0051] Thickener: 0.1-1%.

[0052] The proportions of cement, fly ash, gypsum, sand, amendment, highly active mineral admixture, fiber reinforcement, recycled aggregate, retarder, and thickener are 40%:20%:8%:20%:2%:5%:1%:10%:0.3%:0.5%.

[0053] Through proper proportioning, these materials interact and work together to improve the workability, durability, strength, and stability of concrete. At the same time, they can also reduce the cost of concrete, reduce environmental impact, and promote sustainable building development.

[0054] Autoclaved aerated concrete (AAC) blocks have a compressive strength greater than 60 MPa, enabling them to withstand significant pressure and making them suitable for building structures requiring high load-bearing capacity. Their flexural strength is greater than 10 MPa, allowing them to remain stable under bending or cantilever conditions, preventing breakage or deformation. Their thermal conductivity is less than 0.30 watts per meter Kelvin, indicating excellent insulation properties that effectively reduce heat transfer, improving building energy efficiency and comfort. Their water absorption rate is less than 10%, meaning they have very low water permeability, effectively preventing moisture from seeping into the building and reducing damage caused by humidity and moisture.

[0055] The fiber reinforcement material is glass fiber, a fibrous material made of glass. It possesses high strength, excellent corrosion resistance, and high-temperature resistance. Adding glass fiber to concrete increases its toughness, crack resistance, and impact resistance, preventing crack propagation. Recycled aggregate is made from recycled construction waste, which refers to waste materials generated during the construction process, such as brick fragments, sand, and gravel. Recycling and reusing this construction waste reduces the demand on natural resources, lowers environmental pollution, and promotes sustainable development.

[0056] The improver is a cement water-reducing agent used to improve the strength, durability, and workability of concrete.

[0057] The retarder is sodium silicate, used to adjust the setting time of the blocks, and the thickener is hydroxyethyl cellulose, used to improve the viscosity and fluidity of the block mortar.

[0058] A method for preparing autoclaved aerated concrete blocks includes the following steps:

[0059] S1. Mix cement, fly ash, gypsum and sand evenly;

[0060] S2. Add the modifier to the mixture and stir thoroughly to disperse it evenly;

[0061] S3. Add an appropriate amount of water to form a uniform block mortar;

[0062] S4. Add highly active mineral admixtures and stir thoroughly again.

[0063] S5. Add fiber-reinforced materials and recycled aggregates, and mix thoroughly;

[0064] S6. Add retarder and thickener, and stir thoroughly;

[0065] S7. Pour the slurry into the mold and vibrate it to fully fill the mold;

[0066] S8. Place the mold into an automated autoclave for steam heating at a temperature of 180 degrees Celsius and apply an autoclave pressure of 2 MPa.

[0067] S9. The autoclaved blocks are then naturally cured to obtain finished concrete blocks.

[0068] This preparation method uses basic materials such as cement, fly ash, gypsum, and sand, and improves the performance of concrete by adding modifiers, highly active mineral admixtures, fiber reinforcement materials, and recycled aggregates. During autoclaving, heating and pressure are applied to promote the full reaction and curing of the concrete, thereby obtaining concrete blocks with high strength and excellent performance.

[0069] The blocks should be naturally cured for 24 hours, with relative humidity maintained between 80% and temperature between 20 degrees Celsius.

[0070] Example 2:

[0071] This invention provides an autoclaved aerated concrete block, comprising:

[0072] Cement: 45%;

[0073] Fly ash: 25%;

[0074] Gypsum: 10%;

[0075] Sand: 25%;

[0076] Modifier: 3%;

[0077] Highly active mineral admixtures: 10%;

[0078] Fiber-reinforced material: 2%;

[0079] Recycled aggregate: 20%;

[0080] Retarder: 1%;

[0081] Thickener: 1%.

[0082] Autoclaved aerated concrete (AAC) blocks have a compressive strength greater than 60 MPa, enabling them to withstand significant pressure and making them suitable for building structures requiring high load-bearing capacity. Their flexural strength is greater than 10 MPa, allowing them to remain stable under bending or cantilever conditions, preventing breakage or deformation. Their thermal conductivity is less than 0.30 watts per meter Kelvin, indicating excellent insulation properties that effectively reduce heat transfer, improving building energy efficiency and comfort. Their water absorption rate is less than 10%, meaning they have very low water permeability, effectively preventing moisture from seeping into the building and reducing damage caused by humidity and moisture.

[0083] Fiber reinforcement materials are polymer fibers, which are fibrous materials made of polymers, such as polypropylene fibers and polyester fibers. They are lightweight, high-strength, and have good corrosion resistance. Adding polymer fibers to concrete can improve its toughness, crack resistance, and impact resistance, thus improving its durability. Recycled aggregates are made from recycled waste plastics. By recycling and reusing waste plastics as recycled aggregates, the emission of plastic waste can be reduced, dependence on fossil fuels can be decreased, and the negative environmental impact of plastics can be mitigated.

[0084] The modifier is an air-absorbing agent used to improve the strength, durability, and workability of concrete.

[0085] The retarder is gluconic acid, used to adjust the setting time of the blocks, and the thickener is hydroxypropyl methylcellulose, used to improve the viscosity and fluidity of the block mortar.

[0086] A method for preparing autoclaved aerated concrete blocks includes the following steps:

[0087] S1. Mix cement, fly ash, gypsum and sand evenly;

[0088] S2. Add the modifier to the mixture and stir thoroughly to disperse it evenly;

[0089] S3. Add an appropriate amount of water to form a uniform block mortar;

[0090] S4. Add highly active mineral admixtures and stir thoroughly again.

[0091] S5. Add fiber-reinforced materials and recycled aggregates, and mix thoroughly;

[0092] S6. Add retarder and thickener, and stir thoroughly;

[0093] S7. Pour the slurry into the mold and vibrate it to fully fill the mold;

[0094] S8. Place the mold into an automated autoclave for steam heating at a temperature of 200 degrees Celsius and apply an autoclave pressure of 3 MPa.

[0095] S9. The autoclaved blocks are then naturally cured to obtain finished concrete blocks.

[0096] This preparation method uses basic materials such as cement, fly ash, gypsum, and sand, and improves the performance of concrete by adding modifiers, highly active mineral admixtures, fiber reinforcement materials, and recycled aggregates. During autoclaving, heating and pressure are applied to promote the full reaction and curing of the concrete, thereby obtaining concrete blocks with high strength and excellent performance.

[0097] The blocks are naturally cured for 30 hours, with relative humidity maintained at 90% and temperature maintained between 30 degrees Celsius.

[0098] The experimental data for Embodiments 1 and 2 above are as follows:

[0099]

[0100] The main improvements of this invention compared to existing technologies include higher block strength, better durability, higher density, better energy efficiency, and better environmental friendliness. These improvements give this invention a greater competitive advantage and wider application prospects in the field of building blocks.

[0101] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. An autoclaved aerated concrete block, characterized in that, include: Cement: 35-45%; Fly ash: 15-25%; Gypsum: 5-10%; Sand: 15-25%; Modifier: 1-3%, wherein the modifier is one or more of cement water-reducing agent, reinforcing agent, and foaming agent, used to improve the strength, durability, and workability of concrete; Highly active mineral admixtures: 5-10%; Fiber-reinforcing material: 0.5-2%, wherein the fiber-reinforcing material is glass fiber or polymer fiber; Recycled aggregate: 10-20%, wherein the recycled aggregate is recycled construction waste, waste concrete or waste plastic; Retarder: 0.1-1%; Thickener: 0.1-1%; The autoclaved aerated concrete blocks have a compressive strength greater than 60 MPa, a flexural strength greater than 10 MPa, and a thermal conductivity less than 0.30 watts / meter·Kelvin. The retarder is one or more of sodium silicate, gluconic acid, and triethanolamine, used to adjust the setting time of the blocks. The thickener is one or more of hydroxyethyl cellulose, hydroxypropyl methyl cellulose, polyacrylamide, and polyether polyurethane, used to improve the viscosity and fluidity of the block mortar.

2. The method for preparing autoclaved aerated concrete blocks according to claim 1, characterized in that, Includes the following steps: S1. Mix cement, fly ash, gypsum and sand evenly; S2. Add the modifier to the mixture and stir thoroughly to disperse it evenly; S3. Add an appropriate amount of water to form a uniform block mortar; S4. Add highly active mineral admixtures and stir thoroughly again. S5. Add fiber-reinforced materials and recycled aggregates, and mix thoroughly; S6. Add retarder and thickener, and stir thoroughly; S7. Pour the slurry into the mold and vibrate it to fully fill the mold; S8. Place the mold into an automated autoclave for steam heating at a temperature of 180-200 degrees Celsius and apply an autoclave pressure of 2-3 MPa. S9. The autoclaved blocks are then naturally cured to obtain finished concrete blocks.

3. The method for preparing autoclaved aerated concrete blocks according to claim 2, characterized in that, The blocks are naturally cured for 24-48 hours, with relative humidity maintained between 80-90% and temperature maintained between 20-30 degrees Celsius.

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