A process for processing autoclaved aerated concrete thermal insulation wall

Abstract

The application relates to the technical field of building materials, and discloses a steam-pressure aerated concrete heat-insulation wall processing technology, which comprises the following steps: S1, heat-insulation core material pretreatment: cutting vertical-silk rock wool into a designed size, injecting liquid modified polyurethane into the rock wool through a vacuum-pressing device, the injection pressure being 0.5 MPa-1.5 MPa, and keeping for 30 min-60 min; the modified polyurethane is composed of polyurethane prepolymer, a water-repellent agent and a guide agent, and the weight ratio is 100:3-8:0.5-2; S2, concrete pouring: fixing the pretreated heat-insulation core material in a mold, pouring foamed concrete slurry, the water-cement ratio being 0.45-0.55, and the curing temperature being 50 DEG C-70 DEG C. The unique modified polyurethane is gasified to form a microporous structure, stress concentration is effectively relieved, the low-temperature crack resistance index is greatly improved, and the durability and stability of the wall in a low-temperature environment are greatly enhanced.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of building materials, in particular to a steam-cured aerated concrete thermal insulation wall processing technology. BACKGROUND

[0002] Steam-cured aerated concrete thermal insulation walls have been widely used in the construction field due to their light weight, thermal insulation, sound insulation and other advantages. However, the existing steam-cured aerated concrete thermal insulation walls still have deficiencies in low-temperature crack resistance, water absorption rate and overall thermal insulation performance. In a low-temperature environment, the wall is prone to cracking, affecting its structural stability and service life; a higher water absorption rate can cause water accumulation inside the wall, reducing the thermal insulation effect and possibly causing freeze-thaw damage and other problems. Therefore, it is of great practical significance to develop a steam-cured aerated concrete thermal insulation wall processing technology that can effectively improve low-temperature crack resistance and reduce water absorption rate. SUMMARY

[0003] In view of the deficiencies of the prior art, the present application provides a steam-cured aerated concrete thermal insulation wall processing technology, which significantly improves the low-temperature crack resistance of the thermal insulation wall and reduces the water absorption rate through a series of innovative steps such as pretreatment of the thermal insulation core material, preparation of modified polyurethane and high-temperature steam curing, to meet the demand for high-performance thermal insulation walls in the construction field.

[0004] To achieve the above-mentioned purpose, the present application provides the following technical solution: a steam-cured aerated concrete thermal insulation wall processing technology, comprising the following steps:

[0005] S1, thermal insulation core material pretreatment: cutting vertical filament rock wool to the designed size, injecting liquid modified polyurethane into the rock wool through a vacuum pressurization device, the injection pressure being 0.5 MPa to 1.5 MPa, and maintaining for 30 minutes to 60 minutes; the modified polyurethane is composed of polyurethane prepolymer, hydrophobic agent and directing agent, with a weight ratio of 100:3-8:0.5-2;

[0006] S2, concrete pouring: fixing the pretreated thermal insulation core material in a mold, pouring foamed concrete slurry with a water-cement ratio of 0.45-0.55, and curing at a temperature of 50℃-70℃;

[0007] S3, high-temperature steam curing: curing at 180℃-200℃ and 1.2 MPa-1.5 MPa steam pressure for 8-12 hours, so that the modified polyurethane gasifies and is discharged from the concrete airway, forming a microporous structure.

[0008] Preferably, the preparation method of the directing agent comprises the following steps:

[0009] a. mixing 30-50 parts by weight of silane coupling agent KH-550, 5-10 parts by weight of nano-silicon dioxide and 10-20 parts by weight of graphene dispersion liquid;

[0010] b. In the ultrasonic oscillator, frequency 40 kHz, process 30 min ~ 60 min;

[0011] c. Add polyvinyl butyral 2 ~ 5 parts by weight, stirring at 60 ℃ ~ 80 ℃ until completely dissolved.

[0012] Preferably, the composition of the guiding agent is silane coupling agent KH-550 40 parts by weight, nano-silica 8 parts by weight, graphene dispersion liquid 15 parts by weight, polyvinyl butyral 3 parts by weight.

[0013] Preferably, the hydrophobic agent is a mixture of silicone resin and calcium stearate, the weight ratio is 2:1 ~ 5:1.

[0014] Preferably, the vacuum degree is -0.08 MPa ~ -0.1 MPa, and the pressure stage is divided into three times of stepwise pressure increase, and each pressure increase interval is 5 min.

[0015] Preferably, the preparation method of the modified polyurethane comprises the following steps:

[0016] A. Prepolymer synthesis: polyether polyol (molecular weight 3000 ~ 5000) and polyisocyanate (MDI) are mixed according to the molar ratio of -OH to -NCO 1:1.2 ~ 1:1.5, and reacted at 80 ℃ ~ 90 ℃ under nitrogen protection for 2 h ~ 3 h to prepare a polyurethane prepolymer;

[0017] B. Hydrophobic agent composite: Dissolve silicone resin and calcium stearate in xylene according to the weight ratio of 3:1 ~ 5:1, ultrasonic dispersion for 20 min ~ 30 min, and form a hydrophobic agent suspension;

[0018] C. Guiding agent loading: Mix the guiding agent with n-heptane according to the volume ratio of 1:5 ~ 1:10, high-speed shear emulsification, speed 8000 rpm ~ 12000 rpm, time 15 min ~ 30 min, form nanoscale micelles;

[0019] D. Blending modification: Cool the prepolymer to 50 ℃ ~ 60 ℃, and then add the hydrophobic agent suspension (3wt.% ~ 8wt.%) and the guiding agent micelles (0.5wt.% ~ 2wt.%), and stir and degas under a vacuum degree of -0.05 MPa ~ -0.08 MPa for 1 h ~ 2 h to obtain a liquid modified polyurethane.

[0020] Preferably, the temperature of the high-speed shear emulsification is 25 ℃ ~ 35 ℃, the micelle particle size is 50 nm ~ 200 nm, the viscosity of the modified polyurethane is controlled at 800 mPa·s ~ 1200 mPa·s (25 ℃), the surface tension is ≤25 mN / m, the frequency of the ultrasonic dispersion is 40 kHz, and the power density is 0.5 W / cm 31.0 W / cm 3 .

[0021] Preferably, after autoclaved curing in the high-temperature autoclaved curing, the surface of the concrete forms connected micropores with a pore size of 50-200 mu m, the porosity increases by 5-8%, and the foamed concrete slurry contains 40-60% of Portland cement, 20-30% of fly ash and 0.1-0.3% of foaming agent (aluminum powder).

[0022] Preferably, the low-temperature crack resistance index (residual rate of flexural strength after 50 times of freeze-thaw cycles at-20 DEG C) is greater than or equal to 85%, and the water absorption is less than or equal to 5%.

[0023] Preferably, the thermal conductivity is less than or equal to 0.12 W / (m*K), and the compressive strength is greater than or equal to 3.5 MPa.

[0024] Compared with the prior art, the present application provides a steam pressure aerated concrete thermal insulation wall processing technology, which has the following beneficial effects: from the low-temperature crack resistance, the unique modified polyurethane gasification forms a microporous structure, effectively relieves stress concentration, greatly improves the low-temperature crack resistance index, and greatly enhances the durability and stability of the wall in low-temperature environment;

[0025] In terms of water absorption, the synergistic effect of the hydrophobic agent and the modified polyurethane significantly reduces the water absorption and reduces various problems caused by water intrusion;

[0026] In terms of thermal conductivity, the microporous structure formed by the modified polyurethane plays a good thermal insulation role, effectively improving the energy utilization efficiency of the building; in terms of compressive strength, the process of the present application has reasonable raw material ratio, preparation process and stress dispersion effect of the microporous structure, so that the compressive strength of the wall is significantly improved, meeting the mechanical requirements of the building structure. DETAILED DESCRIPTION

[0027] The technical solutions in the embodiments of the present application will be described below in conjunction with the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the present application.

[0028] Low-temperature crack resistance, test standard: according to the relevant provisions of the low-temperature crack resistance of the thermal insulation wall in the "JGJ144-2019 External Wall External Insulation Engineering Technical Standard".

[0029] Test method: cut the prepared thermal insulation wall test piece into a specified size, put it into a low temperature test box, and freeze-thaw cycle test is carried out according to the temperature condition of-20℃. After each freeze-thaw cycle (frozen stage: keep at-20℃ for a specified time; thawing stage: soak in water at a certain temperature for a specified time), the test piece is tested for bending strength. After 50 freeze-thaw cycles, the bending strength retention rate is calculated, that is, the ratio of the bending strength after 50 freeze-thaw cycles to the initial bending strength, which is taken as the low temperature crack resistance index.

[0030] Water absorption, test standard: refer to the standard for water absorption test in GB / T2542-2012 "Test method for wall brick".

[0031] Test method: select thermal insulation wall test pieces of the required size, first dry the test pieces in an oven at (105±5)℃ to constant weight, record the mass m1 of the test pieces at this time. Then soak the dried test pieces in room temperature water for 48h, remove the surface moisture with a wet cloth, and immediately weigh the test pieces to get the mass m2. The water absorption formula is: (m2-m1) / m1×100%.

[0032] Thermal conductivity, test standard: follow GB / T10294-2008 "Determination of thermal resistance and related properties of thermal insulation materials by guarded hot plate method" for testing.

[0033] Test method: process the thermal insulation wall test piece into a size and shape that meets the requirements of the guarded hot plate method, and install it in the guarded hot plate device. Under steady state conditions, measure the heat flow through the test piece, the cold and hot surface temperature of the test piece, and the geometric size of the test piece, etc. The thermal conductivity of the test piece is calculated.

[0034] Compressive strength, test standard: follow the provisions of GB / T11969-2020 "Test method for performance of autoclaved aerated concrete" for compressive strength test.

[0035] Test method: cut the thermal insulation wall test piece into a standard size cubic test piece, and cure it in an environment of (20±5)℃ to a specified age. Then place the test piece on a pressure testing machine and apply pressure uniformly at a specified loading speed until the test piece fails, and record the failure load value. According to the compression area of the test piece, the compressive strength of the test piece is calculated.

[0036] The common preparation method of autoclaved aerated concrete thermal insulation wall on the market is usually to use ordinary rock wool as the thermal insulation core material without special pretreatment. The foamed concrete slurry is prepared by using Portland cement 55%, fly ash 25%, foaming agent (aluminum powder) 0.2%, and water-cement ratio 0.5. It is cured at room temperature, and then cured at 180℃, 1.2MPa steam pressure for 10h.

[0037] The relevant test equipment used in the present application is as follows, which is not specifically limited, and the corresponding test purposes can be achieved:

[0038] Low temperature test chamber: for example, GDJS-1000 high and low temperature test chamber produced by Ningbo Haishu Saifu Test Instrument Factory, which can accurately control the temperature, meet the low temperature environment requirement of-20℃, and the internal space can accommodate the specified size of the thermal insulation wall test piece for freeze-thaw cycle test.

[0039] Bending strength testing machine: WDW-100 microcomputer control electronic universal testing machine of Jinan Zhongchuang Testing Machine Factory, which has a high-precision force value measurement system and can accurately measure the bending strength of the test piece at different stages, meeting the detection requirements of the bending strength of the test piece in low temperature crack resistance performance test.

[0040] Oven: DHG-9070A electric heating constant temperature air drying oven of Shanghai Yiheng Scientific Instrument Co., Ltd., which can stably control the temperature at (105±5)℃, ensuring that the test piece is dried to a constant weight for accurate mass measurement.

[0041] Electronic balance: ME204E / 02 electronic balance of Mettler-Toledo, with an accuracy of 0.0001g, which can accurately measure the mass of the test piece before and after drying, providing accurate data for water absorption calculation.

[0042] Protective hot plate device: DRPL-II type protective hot plate heat meter of Xiangtan Xiangyi Instrument Co., Ltd., which is strictly designed according to the standard of GB / T10294-2008, can accurately measure the heat flow and cold-hot surface temperature of the test piece under stable conditions, and then accurately calculate the thermal conductivity of the test piece.

[0043] Pressure testing machine: YE-2000B type pressure testing machine of Wuxi Jianyi Instrument & Machinery Co., Ltd., with a maximum test force of 2000kN, uniform and stable loading speed, which can apply pressure to the standard size cubic test piece until failure, and accurately record the failure load value for calculating the compressive strength.

[0044] Example one

[0045] A autoclaved aerated concrete thermal insulation wall processing technology, comprising the following steps:

[0046] The preparation steps of the directing agent are as follows:

[0047] Mixing: mix 30 parts by weight of silane coupling agent KH-550, 5 parts by weight of nano silicon dioxide and 10 parts by weight of graphene dispersion liquid;

[0048] Ultrasonic treatment: treat in an ultrasonic oscillator with a frequency of 40kHz for 30min;

[0049] Dissolution: add polyvinyl butyral 2 parts by weight, stir at 60°C until completely dissolved.

[0050] The modified polyurethane is prepared as follows:

[0051] Prepolymer synthesis: polyether polyol with a molecular weight of 3000 is mixed with polyisocyanate (MDI) at an -OH to -NCO molar ratio of 1:1.2, and reacted at 80°C for 2h under nitrogen protection to prepare a polyurethane prepolymer;

[0052] Hydrophobic agent compounding: silicone resin and calcium stearate are dissolved in xylene at a weight ratio of 3:1, and ultrasonically dispersed at a frequency of 40kHz and a power density of 0.5W / cm³ for 20min to form a hydrophobic agent suspension;

[0053] Guiding agent loading: the guiding agent is mixed with n-heptane at a volume ratio of 1:5, and high-speed sheared at a speed of 8000rpm for 15min at 25°C to form nanoscale micelles;

[0054] Blending modification: the prepolymer is cooled to 50°C, and 3wt.% of the hydrophobic agent suspension and 0.5wt.% of the guiding agent micelles are added in sequence, and stirred to degas under a vacuum degree of -0.05MPa for 1h to obtain a liquid modified polyurethane.

[0055] The steps for preparing the thermal insulation wall body are as follows:

[0056] Thermal insulation core material pretreatment: cut the vertical filament rock wool to the designed size, set the vacuum degree of the vacuum pressure equipment to -0.08MPa, and pressurize in 3 steps with an interval of 5min each time, and inject the pressure to 0.5MPa and maintain for 30min;

[0057] Concrete pouring: fix the pretreated thermal insulation core material in the mold, pour the foamed concrete slurry (portland cement 40%, fly ash 30%, foaming agent (aluminum powder) 0.1%), and maintain the water-cement ratio at 0.45 and the curing temperature at 50°C;

[0058] High-temperature autoclave curing: maintain at 180°C and 1.2MPa steam pressure for 8h.

[0059] Example two

[0060] A processing technology for autoclaved aerated concrete thermal insulation wall body, comprising the following steps:

[0061] The guiding agent is prepared as follows:

[0062] Mixing: mix 40 parts by weight of silane coupling agent KH-550, 8 parts by weight of nanosilica, and 15 parts by weight of graphene dispersion liquid;

[0063] Ultrasonic treatment: Treat in an ultrasonic oscillator at a frequency of 40kHz for 45 minutes;

[0064] Dissolving: Add 3 parts by weight of polyvinyl butyral and stir at 70°C until completely dissolved.

[0065] The preparation steps for modified polyurethane are as follows:

[0066] Prepolymer synthesis: Polyether polyol with a molecular weight of 4000 and polyisocyanate (MDI) were mixed at a molar ratio of -OH to -NCO of 1:1.3 and reacted at 85°C for 2.5 h under nitrogen protection to obtain polyurethane prepolymer;

[0067] Hydrophobic agent composite: Organosilicon resin and calcium stearate are dissolved in xylene at a weight ratio of 4:1, and ultrasonically dispersed at a frequency of 40kHz and a power density of 0.7W / cm³ for 25min to form a hydrophobic agent suspension;

[0068] Initiator loading: The initiator was mixed with n-heptane at a volume ratio of 1:7 and emulsified at 30°C and 10,000 rpm for 20 min to form nano-sized micelles.

[0069] Blending modification: The prepolymer was cooled to 55°C, and 5 wt.% of hydrophobic agent suspension and 1 wt.% of directing agent micelles were added sequentially. The mixture was stirred and degassed for 1.5 h under a vacuum of -0.06 MPa to obtain liquid modified polyurethane.

[0070] The steps for preparing thermal insulation walls are as follows:

[0071] Pretreatment of thermal insulation core material: Cut vertical rock wool into the design size, set the vacuum degree of the vacuum pressurization equipment to -0.09MPa, pressurize in three steps with a 5-minute interval between each pressurization, inject pressure of 1.0MPa and maintain for 45 minutes;

[0072] Concrete pouring: Fix the pretreated insulation core material into the mold, pour foamed concrete slurry (50% silicate cement, 25% fly ash, 0.2% foaming agent (aluminum powder)), water-cement ratio 0.5, curing temperature 60℃;

[0073] High-temperature steam curing: Curing at 190℃ and 1.3MPa steam pressure for 10 hours.

[0074] Example 3

[0075] A process for processing autoclaved aerated concrete (AAC) insulated walls includes the following steps:

[0076] The preparation steps for the induction agent are as follows:

[0077] Mixing: 50 parts by weight of silane coupling agent KH-550, 10 parts by weight of nano-silica, and 20 parts by weight of graphene dispersion liquid were mixed;

[0078] Ultrasonic treatment: treated for 60 min in an ultrasonic oscillator with a frequency of 40 kHz;

[0079] Dissolution: 5 parts by weight of polyvinyl butyral was added and stirred at 80°C until completely dissolved.

[0080] The modified polyurethane was prepared as follows:

[0081] Prepolymer synthesis: polyether polyol with a molecular weight of 5000 was mixed with polyisocyanate (MDI) at an -OH to -NCO molar ratio of 1:1.5, and reacted at 90°C for 3h under nitrogen protection to obtain a polyurethane prepolymer;

[0082] Hydrophobic agent compounding: silicone resin and calcium stearate were dissolved in xylene at a weight ratio of 5:1, and ultrasonically dispersed at a frequency of 40 kHz and a power density of 1.0 W / cm³ for 30 min to form a hydrophobic agent suspension;

[0083] Guiding agent loading: the guiding agent was mixed with n-heptane at a volume ratio of 1:10, and high-speed sheared at a speed of 12000 rpm for 30 min at 35°C to form nanoscale micelles;

[0084] Blending modification: the prepolymer was cooled to 60°C, and 8wt.% of the hydrophobic agent suspension and 2wt.% of the guiding agent micelles were added in sequence, and stirred to degas under a vacuum degree of-0.08 MPa for 2h to obtain a liquid modified polyurethane.

[0085] The steps for preparing the thermal insulation wall are as follows:

[0086] Thermal insulation core material pretreatment: the vertical filament rock wool was cut to the designed size, the vacuum degree of the vacuum pressure equipment was set to-0.1 MPa, the pressure was increased in three steps with an interval of 5 min each time, the injection pressure was 1.5 MPa, and the pressure was maintained for 60 min;

[0087] Concrete pouring: the pretreated thermal insulation core material was fixed in the mold, and the foamed concrete slurry (portland cement 60%, fly ash 20%, foaming agent (aluminum powder) 0.3%) was poured, the water-cement ratio was 0.55, and the curing temperature was 70°C;

[0088] High-temperature autoclave curing: cured at 200°C and 1.5 MPa steam pressure for 12h.

[0089] Comparative Example 1

[0090] Without pre-treatment of the core material, the vertical fiber rock wool is directly fixed in the mold, and the foamed concrete slurry (portland cement 50%, fly ash 25%, foaming agent (aluminum powder) 0.2%) is poured, the water-cement ratio is 0.5, the curing temperature is 60℃, and the curing is carried out at 190℃ and 1.3MPa steam pressure for 10h.

[0091] Comparative Example Two

[0092] The unmodified polyurethane is injected into the vertical fiber rock wool, and the other steps are the same as in Example Two.

[0093] Comparative Example Three

[0094] The commonly used method on the market is selected to prepare the concrete thermal insulation wall.

[0095] Comparative Example Four

[0096] The modified polyurethane is injected into the core material in the same way as in Example Two, but during the high-temperature autoclave curing stage, the temperature and pressure are controlled to prevent the modified polyurethane from being vaporized and discharged (100℃, 0.5MPa curing for 10h).

[0097] The thermal insulation wall of the examples and comparative examples is tested for low-temperature crack resistance, water absorption, thermal conductivity, and tensile strength, and the test results are shown in Tables 1 and 2.

[0098] Table 1 Test results of examples and comparative examples on low-temperature crack resistance and water absorption

[0099]

[0100] Table 2 Test results of examples and comparative examples on thermal conductivity and tensile strength

[0101]

[0102] From the above experimental data, it can be clearly seen that the low-temperature crack resistance is significantly improved: the low-temperature crack resistance indices of Comparative Example One (without pre-treatment of the core material), Comparative Example Two (without modification of polyurethane), Comparative Example Three (commonly used preparation method on the market), and Comparative Example Four (modified polyurethane not vaporized and discharged) are 70%, 75%, 72% and 78% respectively, while the low-temperature crack resistance indices of Examples One to Three are as high as 86%, 88% and 89%. Among them, the comparison between Comparative Example Four and Example Two is particularly striking, as both have similar early treatment, but the low-temperature crack resistance index of Comparative Example Four is much lower than that of Example Two due to the modified polyurethane not being vaporized and discharged. This clearly shows that the microporous structure formed by the vaporization and discharge of the modified polyurethane can effectively relieve low-temperature stress concentration and greatly improve the durability and stability of the wall in a low-temperature environment.

[0103] The water absorption is significantly reduced: the water absorption of the comparative examples 1 to 4 is 8.0%, 7.0%, 7.5% and 6.5% respectively, while the water absorption of the examples 1 to 3 is only 4.8%, 4.5% and 4.2%. The process of the application significantly reduces the surface energy of the material by adding the hydrophobic agent and filling the pores of the thermal insulation core material with modified polyurethane, effectively prevents moisture from entering, greatly reduces the freeze-thaw damage and wall mildew caused by moisture, and the like;

[0104] The thermal conductivity is lower, and the thermal insulation performance is better: the thermal conductivity of the comparative examples 1 to 4 is 0.15 W / (m·K), 0.14 W / (m·K), 0.13 W / (m·K) and 0.13 W / (m·K) respectively, and the thermal conductivity of the examples 1 to 3 is as low as 0.11 W / (m·K), 0.10 W / (m·K) and 0.09 W / (m·K). The microporous structure formed by the modified polyurethane gasification plays a good thermal insulation role, effectively hinders the heat transfer, reduces the thermal conductivity of the wall, significantly improves the energy utilization efficiency of the building, and reduces the energy consumption;

[0105] The compressive strength is higher, and meets the mechanical requirements: the compressive strength of the comparative examples 1 to 4 is 3.0 MPa, 3.2 MPa, 3.1 MPa and 3.3 MPa respectively, and the compressive strength of the examples 1 to 3 is 3.6 MPa, 3.8 MPa and 4.0 MPa. The microporous structure under the process of the application can effectively disperse stress, combined with reasonable raw material ratio and preparation process, greatly improves the compressive performance of the wall, fully guarantees that the wall will not be damaged due to external force in long-term use, and meets the mechanical requirements of the building structure.

[0106] The above is only a specific embodiment of the application, but the technical features of the application are not limited thereto. Any simple change, equivalent replacement or modification made on the basis of the application to solve the same technical problem and achieve the same technical effect is covered by the protection scope of the application.

Claims

1. A processing technology for autoclaved aerated concrete (AAC) insulated walls, characterized in that: Includes the following steps: S1. Pretreatment of thermal insulation core material: Cut vertical rock wool into the designed size, and inject liquid modified polyurethane into the rock wool through a vacuum pressurization device at an injection pressure of 0.5MPa~1.5MPa for 30min~60min; The modified polyurethane is composed of polyurethane prepolymer, water repellent and guiding agent, with a weight ratio of 100:3~8:0.5~2. S2. Concrete pouring: Fix the pretreated insulation core material into the mold, pour foamed concrete slurry, water-cement ratio 0.45~0.55, curing temperature 50℃~70℃; S3. High-temperature autoclaving: Curing at 180℃~200℃ and 1.2MPa~1.5MPa steam pressure for 8h~12h, so that the modified polyurethane is vaporized and discharged from the concrete air duct, forming a microporous structure. The preparation method of the guiding agent includes the following steps: a. Mix 30-50 parts by weight of silane coupling agent KH-550, 5-10 parts by weight of nano-silica, and 10-20 parts by weight of graphene dispersion; b. Treat in an ultrasonic oscillator at a frequency of 40kHz for 30 to 60 minutes; c. Add 2-5 parts by weight of polyvinyl butyral and stir at 60℃-80℃ until completely dissolved.

2. The processing technology for autoclaved aerated concrete (AAC) insulated walls according to claim 1, characterized in that: The guiding agent consists of 40 parts by weight of silane coupling agent KH-550, 8 parts by weight of nano-silica, 15 parts by weight of graphene dispersion, and 3 parts by weight of polyvinyl butyral.

3. The processing technology for autoclaved aerated concrete (AAC) insulated walls according to claim 1, characterized in that: The water-repellent agent is a mixture of organosilicon resin and calcium stearate in a weight ratio of 2:1 to 5:

1.

4. The processing technology for autoclaved aerated concrete (AAC) insulated walls according to claim 1, characterized in that: The operating parameters of the vacuum pressurization equipment in the pretreatment of the thermal insulation core material are: vacuum degree -0.08MPa to -0.1MPa, and the pressurization stage is divided into 3 steps with an interval of 5 minutes between each pressurization.

5. The processing technology for autoclaved aerated concrete (AAC) insulated walls according to claim 1, characterized in that: The preparation method of the modified polyurethane includes the following steps: A. Synthesis of prepolymer: Polyether polyol and polyisocyanate (MDI) are mixed at a molar ratio of -OH to -NCO of 1:1.2 to 1:1.5 and reacted at 80℃ to 90℃ for 2h to 3h under nitrogen protection to obtain polyurethane prepolymer; B. Hydrophobic agent composite: Dissolve organosilicon resin and calcium stearate in xylene at a weight ratio of 3:1 to 5:1, and disperse ultrasonically for 20 to 30 minutes to form a hydrophobic agent suspension. C. Initiator loading: The initiator is mixed with n-heptane at a volume ratio of 1:5 to 1:10, and emulsified by high-speed shearing at a speed of 8000 rpm to 12000 rpm for 15 min to 30 min to form nano-sized micelles. D. Blending modification: Cool the prepolymer to 50℃~60℃, add 3wt.%~8wt.% of hydrophobic agent suspension and 0.5wt.%~2wt.% of guiding agent micelles in sequence, stir and degas under vacuum of -0.05MPa~-0.08MPa for 1h~2h to obtain liquid modified polyurethane.

6. The processing technology for autoclaved aerated concrete (AAC) insulated walls according to claim 5, characterized in that: The high-speed shear emulsification temperature is 25℃~35℃, the micelle size is 50nm~200nm, the viscosity of the modified polyurethane is controlled at 800mPa·s~1200mPa·s, the surface tension is ≤25mN / m, and the ultrasonic dispersion frequency is 40kHz with a power density of 0.5W / cm³. 3 ~1.0W / cm 3 .

7. The processing technology for autoclaved aerated concrete (AAC) insulated walls according to claim 1, characterized in that: After autoclaving in the high-temperature autoclaving process, interconnected micropores with a diameter of 50μm to 200μm are formed on the concrete surface, increasing the porosity by 5% to 8%. The foamed concrete slurry contains 40% to 60% silicate cement, 20% to 30% fly ash, and 0.1% to 0.3% foaming agent.

8. A thermal insulation wall, characterized in that: Prepared using any one of the processes described in claims 1-7, the low-temperature crack resistance index is ≥85% and the water absorption rate is ≤5%.

9. The thermal insulation wall according to claim 8, characterized in that: Thermal conductivity ≤0.12W / (m·K), compressive strength ≥3.5MPa.

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