A highly efficient heat-insulating autoclaved concrete block

Abstract

The invention discloses an efficient heat-insulating autoclaved concrete block, relates to the technical field of concrete blocks, and is made of the following raw materials in parts by weight: 20 to 40 parts by weight of Portland cement, 30 to 60 parts by weight of quartz sand, 40 to 60 parts by weight of water, 5 to 15 parts by weight of lime, 0.6 to 3 parts by weight of aluminum powder, 10 to 20 parts by weight of slag, 5 to 8 parts by weight of polystyrene particles, 1 to 2 parts by weight of reinforcing fiber, and 0.5 to 2 parts by weight of foam stabilizer. The invention increases the lightweight and heat-insulating performance of the block by adding polystyrene particles, reduces heat conduction, and improves the thermal insulation effect. The autoclaved concrete block has a lower thermal conductivity coefficient, so that the air bubble structure generated by the foaming of the aluminum powder is effectively stabilized by the use of aluminum powder and the foam stabilizer, so that the foamed slurry forms a more uniform, dense and stable porous structure, thereby improving the heat-insulating performance and strength of the block.

Description

Technical Field

[0001] The invention relates to the technical field of concrete blocks, in particular to an efficient heat-insulating autoclaved concrete block. Background Art

[0002] As a new type of building material, the porous structure of autoclaved concrete blocks can effectively prevent the conduction of heat, thereby reducing the energy consumption of buildings and adapting to the development trend of building energy conservation. Modern building industrialization requires building materials to have the characteristics of standardization, high quality and easy processing. Autoclaved concrete blocks can be formed by molds, and the size and shape can be precisely controlled to meet the requirements of building industrialization for the standardization of building components. Moreover, this type of block has good processability and can be easily cut, laid and other operations can be carried out at the construction site.

[0003] At present, the pore size distribution inside the existing autoclaved concrete blocks is uneven. Larger pores will make the insulation effect of the air therein worse, because the air in larger pores is more likely to form convection. Moreover, the uneven pore distribution may also lead to local heat conduction differences, affecting the insulation stability of the entire block. Summary of the invention

[0004] The object of the present invention is to provide a highly efficient heat-insulating autoclaved concrete block to solve the problem of uneven distribution of pore sizes in the existing autoclaved concrete blocks mentioned in the above-mentioned background technology. Larger pores will make the heat-insulating effect of air therein worse because the air in larger pores is more likely to form convection. Moreover, the uneven pore distribution may also lead to local heat conduction differences, affecting the heat-insulating stability of the entire block.

[0005] To achieve the above object, the present invention provides the following technical solution: an efficient heat-insulating autoclaved concrete block, the efficient heat-insulating autoclaved concrete block is made of the following raw materials in parts by weight: 20 to 40 parts by weight of Portland cement, 30 to 60 parts by weight of quartz sand, 40 to 60 parts by weight of water, 5 to 15 parts by weight of lime, 0.6 to 3 parts by weight of aluminum powder, 10 to 20 parts by weight of slag, 5 to 8 parts by weight of polystyrene particles, 1 to 2 parts by weight of reinforcing fiber and 0.5 to 2 parts by weight of foam stabilizer;

[0006] The method for preparing the highly efficient heat-insulating autoclaved concrete block comprises the following steps:

[0007] S1. Accurately weigh silicate cement, quartz sand, lime, slag and reinforcing fiber, add them into a blender and stir for 2-3 minutes, add the surface pretreated polystyrene particles and water into the mixed raw materials and stir and mix continuously;

[0008] S2. Slowly add aluminum powder and foam stabilizer under stirring and continue to mix evenly for 6-10 minutes to cause the mixture to foam;

[0009] S3, pouring the foamed slurry into a pre-prepared mold for foaming to form a porous structure;

[0010] S4. Use special cutting equipment to demould the foamed blocks and cut them into the required length and thickness. The cut blocks should be placed in an autoclave for autoclave curing at a temperature of 180-200°C and a pressure of 1.2-1.5MPa.

[0011] S5. Conduct quality inspection on the steam-cured concrete blocks, and dry and store them after they are qualified.

[0012] Preferably, the reinforcing fiber is any one of basalt fiber, glass fiber and carbon fiber.

[0013] Preferably, in step S1, the surface pretreatment of the polystyrene particles comprises the following steps:

[0014] S11, preparing a 2%-5% alcohol solution of a silane coupling agent;

[0015] S12, adding polystyrene particles, stirring and heating to 40-60° C.;

[0016] S13. After the mixing is completed, the mixture is kept for 30-60 minutes to complete the polystyrene particle coating process.

[0017] Preferably, in step S2, the aluminum powder is added three times, and stirred for 2-3 minutes after each addition.

[0018] Preferably, in step S3, the foamed slurry is left to stand for 1-3 minutes before being poured into the mold.

[0019] Preferably, in step S4, the autoclave curing adopts a process of heating up, constant temperature and cooling in stages, including the following steps:

[0020] S41, heating stage: heating to 60-80℃ at a rate of 15-20℃ / h and maintaining the temperature at this temperature for 2-3h to allow the hydration reaction inside the block to proceed initially and further stabilize the bubble structure;

[0021] S42, then raise the temperature to 180-200°C at a rate of 20-25°C / h and keep the temperature constant for 6-8h to carry out hydration reaction and strength formation;

[0022] S43, during the cooling stage, the temperature is slowly lowered to room temperature at a rate not exceeding 30°C / h to avoid cracking of the blocks due to temperature stress caused by a sudden drop in temperature.

[0023] Preferably, in step S4, the foamed blocks are lightly sprayed before demoulding to ensure that the surface is moistened.

[0024] Preferably, the foam stabilizer is any one of sodium dodecylbenzene sulfonate, sodium fatty alcohol polyoxyethylene ether sulfate and polyvinyl alcohol.

[0025] Compared with the prior art, the present invention has the following beneficial effects:

[0026] 1. In the present invention, the addition of polystyrene particles increases the weight and thermal insulation performance of the blocks, reduces heat conduction, and improves the thermal insulation effect. The autoclaved concrete blocks have a lower thermal conductivity coefficient so that they can effectively prevent the transfer of heat. The use of aluminum powder and a foam stabilizer effectively stabilizes the bubble structure generated by the foaming of aluminum powder, prevents the bubbles from bursting and merging, and makes the foamed slurry form a more uniform, dense and stable porous structure, thereby improving the thermal insulation performance and strength of the blocks.

[0027] 2. In the present invention, the surface properties of polystyrene particles are improved by coating them, so that chemical bonding or strong physical adsorption is formed between the polystyrene particles and the cement matrix, thereby enhancing the interfacial bonding force, ensuring the integrity and mechanical properties of the blocks, and having high compressive strength so that the autoclaved concrete blocks can withstand the dead weight and additional loads of the building. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 The present invention is a flow chart of a highly efficient heat-insulating autoclaved concrete block. DETAILED DESCRIPTION

[0029] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the implementation regulations described are only part of the embodiments of the present invention, not all of the embodiments. 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.

[0030] The present invention will be further described below in conjunction with the embodiments.

[0031] Example 1

[0032] like Figure 1 As shown, this embodiment provides a highly efficient heat-insulating autoclaved concrete block, which is made of the following raw materials in parts by weight: 20 parts by weight of Portland cement, 30 parts by weight of quartz sand, 40 parts by weight of water, 5 parts by weight of lime, 0.6 parts by weight of aluminum powder, 10 parts by weight of slag, 5 parts by weight of polystyrene particles, 1 part by weight of reinforcing fiber and 0.5 parts by weight of foam stabilizer;

[0033] Among them, basalt fiber is used as reinforcing fiber, and sodium dodecylbenzene sulfonate is used as foam stabilizer;

[0034] The method for preparing a highly efficient heat-insulating autoclaved concrete block comprises the following steps:

[0035] Step 1: Accurately weigh silicate cement, quartz sand, lime, slag and reinforcing fiber, add them into a blender and stir for 2-3 minutes, add the surface pretreated polystyrene particles and water into the mixed raw materials and stir and mix continuously;

[0036] The process of pretreatment of the surface of polystyrene particles is as follows: first, a silane coupling agent is prepared into a 2%-5% alcohol solution; then, polystyrene particles are added thereto, stirred and heated to 40-60° C.; after mixing, the mixture is kept for 30-60 minutes to complete the coating treatment of the polystyrene particles;

[0037] Step 2: slowly add aluminum powder and foam stabilizer under stirring and continue to mix evenly for 6-10 minutes to cause the mixture to foam; wherein, the aluminum powder is added three times, and stirred for 2-3 minutes after each addition;

[0038] Step 3: Pour the foamed slurry into a pre-prepared mold for foaming to form a porous structure; wherein, before pouring the foamed slurry into the mold, let it stand for 1-3 minutes;

[0039] Step 4: Use special cutting equipment to demould the foamed blocks and cut them into the required length and thickness. The cut blocks should be placed in an autoclave for autoclave curing at a temperature of 180-200°C and a pressure of 1.2-1.5MPa. Before demoulding, lightly spray the foamed blocks to ensure that the surface is moist.

[0040] Among them, the autoclave curing adopts a process of heating up, constant temperature and cooling in stages, including the following steps:

[0041] 41) During the heating stage, the temperature is raised to 60-80°C at a rate of 15-20°C / h and maintained at this temperature for 2-3h;

[0042] 42) Then raise the temperature to 180-200°C at a rate of 20-25°C / h and keep the temperature constant for 6-8h;

[0043] 43) During the cooling stage, the temperature is slowly cooled to room temperature at a rate not exceeding 30°C / h;

[0044] Step 5: Conduct quality inspection on the steamed concrete blocks, and dry and store them after they pass the inspection.

[0045] Example 2

[0046] like Figure 1 As shown, this embodiment provides a highly efficient heat-insulating autoclaved concrete block, which is made of the following raw materials in parts by weight: 30 parts by weight of Portland cement, 45 parts by weight of quartz sand, 50 parts by weight of water, 10 parts by weight of lime, 2 parts by weight of aluminum powder, 15 parts by weight of slag, 6 parts by weight of polystyrene particles, 1.5 parts by weight of reinforcing fiber and 1 part by weight of foam stabilizer;

[0047] Among them, glass fiber is used as reinforcing fiber, and sodium dodecylbenzene sulfonate is used as foam stabilizer;

[0048] The method for preparing a highly efficient heat-insulating autoclaved concrete block comprises the following steps:

[0049] Step 1: Accurately weigh silicate cement, quartz sand, lime, slag and reinforcing fiber, add them into a blender and stir for 2-3 minutes, add the surface pretreated polystyrene particles and water into the mixed raw materials and stir and mix continuously;

[0050] The process of pretreatment of the surface of polystyrene particles is as follows: first, a silane coupling agent is prepared into a 2%-5% alcohol solution; then, polystyrene particles are added thereto, stirred and heated to 40-60° C.; after mixing, the mixture is kept for 30-60 minutes to complete the coating treatment of the polystyrene particles;

[0051] Step 2: slowly add aluminum powder and foam stabilizer under stirring and continue to mix evenly for 6-10 minutes to cause the mixture to foam; wherein, the aluminum powder is added three times, and stirred for 2-3 minutes after each addition;

[0052] Step 3: Pour the foamed slurry into a pre-prepared mold for foaming to form a porous structure; wherein, before pouring the foamed slurry into the mold, let it stand for 1-3 minutes;

[0053] Step 4: Use special cutting equipment to demould the foamed blocks and cut them into the required length and thickness. The cut blocks should be placed in an autoclave for autoclave curing at a temperature of 180-200°C and a pressure of 1.2-1.5MPa. Before demoulding, lightly spray the foamed blocks to ensure that the surface is moist.

[0054] Among them, the autoclave curing adopts a process of heating up, constant temperature and cooling in stages, including the following steps:

[0055] 41) During the heating stage, the temperature is raised to 60-80°C at a rate of 15-20°C / h and maintained at this temperature for 2-3h;

[0056] 42) Then raise the temperature to 180-200°C at a rate of 20-25°C / h and keep the temperature constant for 6-8h;

[0057] 43) During the cooling stage, the temperature is slowly cooled to room temperature at a rate not exceeding 30°C / h;

[0058] Step 5: Conduct quality inspection on the steamed concrete blocks, and dry and store them after they pass the inspection.

[0059] Example 3

[0060] like Figure 1 As shown, this embodiment provides a highly efficient heat-insulating autoclaved concrete block, which is made of the following raw materials in parts by weight: 40 parts by weight of Portland cement, 60 parts by weight of quartz sand, 60 parts by weight of water, 15 parts by weight of lime, 3 parts by weight of aluminum powder, 20 parts by weight of slag, 8 parts by weight of polystyrene particles, 2 parts by weight of reinforcing fiber and 2 parts by weight of foam stabilizer;

[0061] Among them, glass fiber is used as reinforcing fiber, and sodium dodecylbenzene sulfonate is used as foam stabilizer;

[0062] The method for preparing a highly efficient heat-insulating autoclaved concrete block comprises the following steps:

[0063] Step 1: Accurately weigh silicate cement, quartz sand, lime, slag and reinforcing fiber, add them into a blender and stir for 2-3 minutes, add the surface pretreated polystyrene particles and water into the mixed raw materials and stir and mix continuously;

[0064] The process of pretreatment of the surface of polystyrene particles is as follows: first, a silane coupling agent is prepared into a 2%-5% alcohol solution; then, polystyrene particles are added thereto, stirred and heated to 40-60° C.; after mixing, the mixture is kept for 30-60 minutes to complete the coating treatment of the polystyrene particles;

[0065] Step 2: slowly add aluminum powder and foam stabilizer under stirring and continue to mix evenly for 6-10 minutes to cause the mixture to foam; wherein, the aluminum powder is added three times, and stirred for 2-3 minutes after each addition;

[0066] Step 3: Pour the foamed slurry into a pre-prepared mold for foaming to form a porous structure; wherein, before pouring the foamed slurry into the mold, let it stand for 1-3 minutes;

[0067] Step 4: Use special cutting equipment to demould the foamed blocks and cut them into the required length and thickness. The cut blocks should be placed in an autoclave for autoclave curing at a temperature of 180-200°C and a pressure of 1.2-1.5MPa. Before demoulding, lightly spray the foamed blocks to ensure that the surface is moist.

[0068] Among them, the autoclave curing adopts a process of heating up, constant temperature and cooling in stages, including the following steps:

[0069] 41) During the heating stage, the temperature is raised to 60-80°C at a rate of 15-20°C / h and maintained at this temperature for 2-3h;

[0070] 42) Then raise the temperature to 180-200°C at a rate of 20-25°C / h and keep the temperature constant for 6-8h;

[0071] 43) During the cooling stage, the temperature is slowly cooled to room temperature at a rate not exceeding 30°C / h;

[0072] Step 5: Conduct quality inspection on the steamed concrete blocks, and dry and store them after they pass the inspection.

[0073] Comparative Example 1

[0074] The highly efficient heat-insulating autoclaved concrete block provided in this embodiment is substantially the same as that in Embodiment 1, with the main difference being that no polystyrene particles are added to the raw materials.

[0075] Comparative Example 2

[0076] The highly efficient heat-insulating autoclaved concrete block provided in this embodiment is substantially the same as that in Embodiment 1, with the main difference being that no foam stabilizer is added to the raw materials.

[0077] Comparative Example 3

[0078] The highly efficient heat-insulating autoclaved concrete block provided in this embodiment is substantially the same as that in Embodiment 1, with the main difference being that in step 1, the polystyrene particles are not subjected to surface pretreatment.

[0079] Performance testing and result analysis

[0080] The high-efficiency heat-insulating autoclaved concrete blocks prepared in Examples 1-3 and Comparative Examples 1-3 were respectively subjected to performance tests: thermal conductivity test, compressive strength test, water absorption test and freeze-thaw cycle frost resistance test, testing standard: GB / T11968-2020, and the relevant data are recorded in Table 1;

[0081] Table 1: Test data record table

[0082]

[0083] As can be seen from Table 1, compared with the comparative example, the highly efficient heat-insulating autoclaved concrete blocks prepared in Examples 1-3 have excellent thermal conductivity, compressive strength, water absorption and frost resistance. The lower thermal conductivity enables the autoclaved concrete blocks to effectively prevent the transfer of heat, and the higher compressive strength enables the autoclaved concrete blocks to withstand the deadweight and additional loads of the building. The lower water absorption can prevent the blocks from absorbing too much moisture, and avoid the increase in thermal conductivity due to the entry of moisture into the pores, thereby maintaining its good thermal insulation performance. It will not excessively absorb water and expand in a humid environment, and will not excessively shrink due to water loss in a dry environment, thereby extending the service life of the blocks and improving the durability of the building. The autoclaved concrete blocks with excellent frost resistance can withstand multiple freeze-thaw cycles without obvious damage, and the present invention has a uniform pore structure that helps to improve the thermal insulation performance, because the uniformly distributed micropores can minimize heat conduction and heat convection.

[0084] Although the present invention has been described in detail with reference to the aforementioned embodiments, it is still possible for those skilled in the art to modify the technical solutions described in the aforementioned embodiments, or to make equivalent substitutions for some of the technical features therein. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A highly efficient heat-insulating autoclaved concrete block, characterized in that: The highly efficient heat-insulating autoclaved concrete block is made of the following raw materials in parts by weight: 20 to 40 parts by weight of Portland cement, 30 to 60 parts by weight of quartz sand, 40 to 60 parts by weight of water, 5 to 15 parts by weight of lime, 0.6 to 3 parts by weight of aluminum powder, 10 to 20 parts by weight of slag, 5 to 8 parts by weight of polystyrene particles, 1 to 2 parts by weight of reinforcing fiber and 0.5 to 2 parts by weight of a foam stabilizer; The method for preparing the highly efficient heat-insulating autoclaved concrete block comprises the following steps: S1. Accurately weigh silicate cement, quartz sand, lime, slag and reinforcing fiber, add them into a blender and stir for 2-3 minutes, add the surface pretreated polystyrene particles and water into the mixed raw materials and stir and mix continuously; S2. Slowly add aluminum powder and foam stabilizer under stirring and continue to mix evenly for 6-10 minutes to cause the mixture to foam; S3, pouring the foamed slurry into a pre-prepared mold for foaming to form a porous structure; S4. Use special cutting equipment to demould the foamed blocks and cut them into the required length and thickness. The cut blocks should be placed in an autoclave for autoclave curing at a temperature of 180-200°C and a pressure of 1.2-1.5MPa. S5. Conduct quality inspection on the steam-cured concrete blocks, and dry and store them after they are qualified.

2. The highly efficient heat-insulating autoclaved concrete block according to claim 1, characterized in that: The reinforcing fiber is selected from any one of basalt fiber, glass fiber and carbon fiber.

3. The highly efficient heat-insulating autoclaved concrete block according to claim 1, characterized in that: In step S1, the surface pretreatment of the polystyrene particles comprises the following steps: S11, preparing a 2%-5% alcohol solution of a silane coupling agent; S12, adding polystyrene particles, stirring and heating to 40-60° C.; S13. After the mixing is completed, the mixture is kept for 30-60 minutes to complete the polystyrene particle coating process.

4. The highly efficient heat-insulating autoclaved concrete block according to claim 1, characterized in that: In step S2, the aluminum powder is added three times, and stirred for 2-3 minutes after each addition.

5. The highly efficient heat-insulating autoclaved concrete block according to claim 1, characterized in that: In step S3, before the foamed slurry is poured into the mold, it is first left to stand for 1-3 minutes.

6. The highly efficient heat-insulating autoclaved concrete block according to claim 1, characterized in that: In step S4, the autoclave curing adopts a process of heating up, constant temperature and cooling in stages, including the following steps: S41, heating stage: heating to 60-80℃ at a rate of 15-20℃ / h, and keeping the temperature constant for 2-3h; S42, then raise the temperature to 180-200°C at a rate of 20-25°C / h and keep the temperature constant for 6-8h; S43, cooling stage: slowly cooling to room temperature at a rate not exceeding 30°C / h.

7. The highly efficient heat-insulating autoclaved concrete block according to claim 1, characterized in that: In step S4, the foamed blocks are lightly sprayed before demoulding to ensure that the surface is moistened.

8. The highly efficient heat-insulating autoclaved concrete block according to claim 1, characterized in that: The foam stabilizer is selected from any one of sodium dodecylbenzene sulfonate, sodium fatty alcohol polyoxyethylene ether sulfate and polyvinyl alcohol.

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