Aerated concrete block and light thermal and sound insulation composite block

Abstract

The application relates to the technical field of concrete, and particularly discloses an aerated concrete block and a light-weight heat-preservation and sound-insulation composite block, the aerated concrete block comprises the following raw materials in parts by weight: ordinary Portland cement 120-180 parts, lime 100-120 parts, quartz sand 650-750 parts, aluminum powder paste 0.8-1.2 parts, modified fiber 0.5-0.8 parts and water 300-357 parts; the modified fiber is one or both of poly-caprolactone modified polypropylene fiber and ethylene-vinyl acetate modified basalt fiber. The organic groups of the modified fiber can form molecular entanglement with the organic components of the foaming heat-preservation layer, and simultaneously form weak bonds with the hydroxyl groups and calcium ions of the hydration products of the aerated concrete matrix, so that the chemical barrier of the inorganic-organic interface is broken from the side of the matrix, the bonding strength of the aerated concrete block and the heat-preservation core layer is improved, and the heat-preservation property and the sound-insulation effect of the composite block are improved.

Description

Technical Field

[0001] This application relates to the field of concrete technology, and more specifically, to an aerated concrete block and a lightweight thermal insulation and soundproof composite block. Background Technology

[0002] With the rapid development of the green building and building energy conservation industry, my country has put forward higher requirements for the lightweight, thermal insulation, sound insulation and noise reduction, structural stability and environmental protection of wall materials. The 75% building energy conservation standard has become a mandatory requirement for new buildings. At the same time, the resource utilization of industrial solid waste and the research and development of low-carbon building materials have become the core directions of the industry.

[0003] Among existing wall materials, traditional clay bricks have been abandoned due to their high energy consumption and damage to arable land; although aerated concrete blocks have lightweight characteristics, they have problems such as poor sound insulation, insufficient crack resistance, and thermal insulation performance greatly affected by pore structure; ordinary concrete composite blocks mostly adopt a structural composite mode of concrete shell and thermal insulation core material, relying on mechanical composite to achieve functional integration, but they generally have defects such as low bonding strength between core material and matrix interface, easy peeling and falling off, obvious thermal bridging effect, and prominent low-frequency sound insulation shortcomings. For example, patent application CN107268870A discloses an autoclaved aerated concrete composite self-insulating block and its manufacturing method. It has a three-layer composite structure, including autoclaved aerated concrete layers on both sides and a foamed phenolic board insulation layer disposed between the two autoclaved aerated concrete layers. An interface agent layer is independently disposed between the foamed phenolic insulation layer and the two autoclaved aerated concrete layers. The insulating block also includes a tie member, which penetrates the foamed phenolic board insulation layer. The two ends of the tie member are respectively disposed inside the two autoclaved aerated concrete layers.

[0004] Although the patent application optimizes the interface bonding through an interface bonding reinforcement layer and tie-in components, it does not disclose the specific formula of the interface layer and relies solely on physical interlocking to bond the aerated concrete layer with the foamed phenolic board insulation layer. However, there is a difference in the coefficients of thermal expansion and contraction between aerated concrete and organic insulation core layer. During long-term service, the interface stress concentration can easily lead to delamination, resulting in gaps between the aerated concrete and the composite core layer. These gaps form air channels, destroying the continuous insulation barrier and reducing the insulation performance of the composite block. At the same time, the gaps form sound bridges, allowing high-frequency sound waves to propagate directly, while low-frequency sound waves are more easily transmitted due to the unrestrained interface vibration, weakening the sound insulation effect of the composite block. Summary of the Invention

[0005] In order to develop a lightweight thermal insulation and sound insulation composite block, this application provides an aerated concrete block and a lightweight thermal insulation and sound insulation composite block.

[0006] In a first aspect, this application provides an aerated concrete block, which adopts the following technical solution:

[0007] An aerated concrete block comprises the following raw materials in parts by weight: 120-180 parts ordinary silicate cement, 100-120 parts lime, 650-750 parts quartz sand, 0.8-1.2 parts aluminum powder paste, 0.5-0.8 parts modified fiber, and 300-357 parts water; wherein the modified fiber is one or two of polycaprolactone-modified polypropylene fiber and ethylene-vinyl acetate-modified basalt fiber.

[0008] By adopting the above technical solution, the organic groups of the modified fiber can form molecular entanglement with the organic components of the foamed insulation layer, and at the same time form weak bonds with the hydroxyl and calcium ions of the hydration products of the aerated concrete matrix. This breaks the chemical barrier of the inorganic-organic interface from the matrix side, improves the bonding strength between the aerated concrete block and the insulation core layer, and thus improves the thermal insulation and sound insulation effect of the composite block.

[0009] Preferably, the modified fiber is a mixture of polycaprolactone-modified polypropylene fiber and ethylene-vinyl acetate-modified basalt fiber in a mass ratio of (6-8):(2-4).

[0010] By adopting the above technical solutions, the high proportion of polycaprolactone-modified polypropylene fiber can form stable weak bonds with the hydroxyl and calcium ions of the hydration products of the aerated concrete matrix through its surface ester groups, strengthening the bond between the fiber and the matrix. At the same time, the polycaprolactone segments are flexible, which can buffer the interfacial stress between the matrix and the core layer caused by thermal expansion and contraction, avoiding interfacial cracking caused by stress concentration. The flexible segments can also form certain molecular interactions with the organic core layer, laying the foundation for basic compatibility. The low proportion of ethylene-vinyl acetate (EVA)-modified basalt fiber, with the high strength of basalt fiber, constructs a rigid support network, inhibiting the drying shrinkage cracks and macroscopic damage of the aerated concrete matrix, avoiding interfacial gaps caused by matrix defects. Its surface EVA-modified layer can also improve the compatibility with various interfacial bonding materials, further ensuring the stability of the interfacial connection between the matrix and the core layer. The combined use of these two methods can create an interface-friendly foundation for the core layer from the matrix side through the synergy of flexible stress buffering and rigid structural reinforcement. At the same time, the modified groups can improve the bonding ability, providing a guarantee for the chemical and physical bonding between the matrix and the core layer. This avoids the limitations of single fiber modification, which can only buffer stress without structural support or provide strong support but is prone to stress cracking.

[0011] Secondly, this application provides a lightweight thermal insulation and soundproof composite block, which adopts the following technical solution:

[0012] A lightweight thermal insulation and soundproof composite block includes two layers of aerated concrete blocks, an inner and an outer layer, and a composite core layer sandwiched between the two layers of aerated concrete blocks.

[0013] By adopting the above technical solution, the structural design of double-layer modified aerated concrete blocks with a composite core layer can not only rely on the modified matrix to ensure the overall structural stability, but also reduce the formation of thermal bridges and sound bridges. While retaining the lightweight characteristics of aerated concrete, it effectively improves the defects of traditional composite blocks, such as poor thermal insulation performance, insufficient sound insulation effect, and easy peeling of the interface.

[0014] The composite core layer comprises the following raw materials in parts by weight: 65-70 parts polystyrene, 5-10 parts heat insulation agent, 5-6 parts foaming agent, 2-3 parts talc powder, and 15-19 parts modifier.

[0015] The preparation method of the modifier includes the following steps:

[0016] (1) Add 100 parts by weight of nano-calcium carbonate to 350-450 parts by weight of xylene, disperse by ultrasonication, then add 10-14 parts by weight of polycaprolactone and 0.4-0.6 parts by weight of tetrabutyl titanate, heat to 90-100℃ and stir for 5-7 hours. After the reaction is completed, filter and dry to obtain nano-calcium carbonate grafted with polycaprolactone.

[0017] (2) 100 parts by weight of linear SBS and 0.4-0.6 parts by weight of antioxidant 1010 are melted together, and 45-55 parts by weight of nano-calcium carbonate grafted polycaprolactone are added. The mixture is then extruded and granulated to obtain the composite.

[0018] By adopting the above technical solutions, the modifier can effectively enhance the interfacial bonding strength between the composite core layer and the inner and outer aerated concrete blocks, solving the common problems of weak interfacial bonding and easy peeling and detachment between the core material and the matrix in ordinary concrete composite blocks. At the same time, the composite structure of the inner and outer aerated concrete and the composite core layer can synergistically improve the overall sound insulation performance, especially making up for the poor sound insulation effect of aerated concrete blocks and the prominent low-frequency sound insulation shortcomings of ordinary composite blocks. It achieves simultaneous optimization of thermal insulation and sound insulation performance, and finally forms a composite block with lightweight, high thermal insulation, strong interfacial bonding and excellent sound insulation performance, meeting the comprehensive needs of building walls for weight reduction, thermal insulation, sound insulation and structural stability.

[0019] Preferably, the preparation method of the modifier further includes step (3), which is: mixing the composite with modified perlite in a mass ratio of (5-7):(3-5) to obtain the modifier; wherein the modified perlite is obtained by modifying perlite micro powder with mercaptosilane coupling agent.

[0020] By employing the above technical solution, perlite micropowder is surface-modified using a mercaptosilane coupling agent. The alkoxy groups of the silane molecules hydrolyze to generate silanol groups, which then undergo a condensation reaction with the hydroxyl groups on the surface of the perlite micropowder to achieve chemical grafting. This transforms the perlite surface from an inorganic polarity to one with organic compatibility. Furthermore, the surface mercapto groups can interact with the double bonds of SBS and the ester groups of polycaprolactone in the composite to obtain the modifier. This not only improves the bidirectional compatibility of the modifier with the composite core layer and aerated concrete, but also enhances the interfacial bonding strength through the bridging effect of mercaptosilane and the physical anchoring of perlite. Moreover, the porous structure of the modified perlite synergistically improves the thermal insulation and sound insulation performance of the composite core layer.

[0021] Preferably, the preparation method of the slurry used in the composite core layer is as follows: weigh the raw materials according to the formula, mix them evenly, and then extrude and foam them to obtain the core layer slurry.

[0022] By employing the above technical solution, the thermal insulation performance relies on the closed-cell structure of the polystyrene substrate and the low-emissivity of graphite micropowder to achieve a low thermal conductivity. Meanwhile, the high-density characteristics of the dispersed phase nano-calcium carbonate increase the density of the core layer, effectively blocking high-frequency sound waves according to the mass law. The high damping characteristics of the SBS elastomer combined with the flexibility of the PCL grafted chains effectively absorb mid-frequency sound wave vibration energy. Furthermore, the uniform dispersion of the dispersed phase prevents the formation of sound bridges. These three factors synergistically improve the sound insulation performance of the composite core layer. The preparation method is simple and has high industrial feasibility.

[0023] Preferably, the foaming agent is a mixture of sodium bicarbonate and pentane in a mass ratio of (4-6):(4-5).

[0024] By adopting the above technical solution, sodium bicarbonate decomposes upon heating to release carbon dioxide, with a wide gas production temperature range, and can form a stable bubble structure; pentane has a low boiling point and volatilizes first at a lower temperature to produce gas, replenishing the number of bubbles; when the two are used together, they can achieve continuous low-temperature gas induction and medium-high temperature bubble stabilization during the extrusion-foaming process of the composite core layer, achieving synergistic optimization of lightweight, heat insulation and sound insulation performance.

[0025] Preferably, the heat insulation agent is obtained by grafting polycaprolactone onto the surface of the heat insulation material; the heat insulation material is graphite and / or nano-silica aerogel.

[0026] By adopting the above technical solution, the hydroxyl groups on the surfaces of graphite and aerogel can form hydrogen bonds with the terminal hydroxyl groups of polycaprolactone (PCL), forming a stable interfacial connection. At the same time, the flexible long chains of PCL form a dense steric hindrance layer on the surfaces of the two materials. This not only breaks the van der Waals forces between graphite sheets and covers the hydroxyl groups on the aerogel surface that are prone to forming hydrogen bonds, but also fundamentally inhibits the aggregation tendency of the two materials individually and after mixing. Furthermore, because PCL is homologous with the polystyrene (PS), SBS, and modifiers in the composite core layer, the compatibility between the thermal insulation agent and the organic substrate is greatly improved, ensuring better dispersion uniformity without modifying the original preparation process. Moreover, the grafting process does not damage the infrared reflection characteristics of graphite and the porous thermal insulation structure of aerogel. The low thermal conductivity of PCL itself does not affect the synergistic effect of dual thermal insulation. Its flexible chains can also alleviate the shear stress during the extrusion-foaming process, reduce shrinkage cracks in the composite core layer, and indirectly improve the structural stability and sound insulation performance of the lightweight thermal insulation and soundproofing blocks.

[0027] The heat insulation agent is a mixture of graphite-grafted polycaprolactone and nano-silica aerogel-grafted polycaprolactone in a mass ratio of (6-8):(2-4).

[0028] By adopting the above technical solution, PCL is stably grafted onto graphite and aerogel respectively. The flexible PCL chains construct a steric hindrance layer on the surface of the two components and impart organic affinity properties. The high proportion of graphite-grafted PCL dominates radiative heat insulation, while the low proportion of aerogel-grafted PCL focuses on blocking heat conduction. The two form a dual heat insulation barrier of radiation and conduction. This ensures that the graphite is evenly distributed to avoid radiative heat insulation blind spots, while a small amount of aerogel can make up for the shortcomings of conduction heat insulation. At the same time, both components have homologous PCL chains on their surfaces, with consistent interfacial tension. After mixing, they are evenly dispersed without agglomeration and have high compatibility with composite core layers such as polystyrene and SBS, thereby improving the thermal insulation stability of lightweight thermal and sound insulation blocks.

[0029] Preferably, the aerated concrete blocks and the composite core layer are bonded together by polymer-modified mortar.

[0030] Preferably, the polymer-modified mortar comprises the following raw materials in parts by weight: 40-45 parts of ordinary silicate cement, 35-40 parts of quartz sand, 10-12 parts of ethylene-vinyl acetate emulsion, 2-3 parts of perlite micro powder modified with mercaptosilane coupling agent, 0.3-0.5 parts of cellulose ether, and 12-14 parts of water.

[0031] By adopting the above technical solution, ordinary silicate cement is used as the inorganic matrix. Its chemical compatibility with the cement-based surface of aerated concrete provides basic bonding strength through the interaction of hydroxyl groups from hydration products with the hydroxyl groups on the aerated concrete surface. Quartz sand, with a particle size adapted to the rough texture of the aerated concrete interface, controls the mortar shrinkage rate and avoids curing cracking. Ethylene-vinyl acetate emulsion is homologous to the polystyrene and SBS elastomers in the composite core layer, enhancing the organic compatibility between the mortar and the core layer and imparting flexibility. A mercaptosilane coupling agent modifies perlite micropowder, playing a bidirectional bridging role. Silyl groups condense with the hydroxyl groups on the aerated concrete surface, and mercapto groups interact with the SBS double bonds in the core layer, further strengthening the interfacial connection. Cellulose ether improves water retention and adapts to the extrusion and foaming processes of the core layer. Through the synergistic effect of the components, the above formulation improves the adhesion between aerated concrete blocks and the composite core layer.

[0032] In summary, this application has the following beneficial effects:

[0033] 1. The modified fibers in the aerated concrete blocks of this application break down the chemical barrier of the inorganic-organic interface from the matrix side, improve the bonding strength between the aerated concrete blocks and the insulation core layer, thereby improving the thermal insulation and sound insulation effect of the composite blocks.

[0034] 2. The modifier in the composite core layer of this application can effectively enhance the interfacial bonding strength between the composite core layer and the inner and outer aerated concrete blocks, solving the common problem of weak interfacial bonding between the core material and the matrix and easy peeling and falling off in ordinary concrete composite blocks.

[0035] 3. The thermal insulation agent of this application is graphite-grafted polycaprolactone and nano-silica aerogel-grafted polycaprolactone. PCL is grafted onto graphite and aerogel respectively. The flexible chain of PCL constructs a steric hindrance layer and imparts organic affinity properties, forming a dual barrier with high proportion of graphite as the main radiative thermal insulation and low proportion of aerogel as the main conductive thermal insulation. Moreover, the two are uniformly dispersed without agglomeration due to the homologous PCL chain, and have high compatibility with the composite core substrate, thereby improving the thermal insulation stability of the lightweight thermal insulation and sound insulation block. Detailed Implementation

[0036] The present application will be further described in detail below with reference to the embodiments. Unless otherwise specified, the raw materials used in the preparation examples, embodiments and comparative examples of the present application are all commercially available.

[0037] Preparation Example 1

[0038] This preparation example discloses a composite core layer, which specifically includes the following steps:

[0039] (1) Modifier: Weigh 100 kg of 50-100 nm nano-calcium carbonate and add it to 400 kg of xylene. After ultrasonic dispersion at 300 W for 30 min, add 12 kg of 5000 molecular weight polycaprolactone and 0.5 kg of tetrabutyl titanate catalyst. Heat to 95 °C and stir for 6 h. After the reaction is completed, filter and vacuum dry at 80 °C for 4 h to obtain nano-calcium carbonate grafted polycaprolactone. Add 100 kg of linear SBS (block ratio 30:70) and 0.5 kg of antioxidant 1010 to a twin-screw extruder. Melt according to the temperature parameters of 120 °C in the feeding section, 150-160 °C in the melting section and 140 °C in the homogenization section. Add 50 kg of nano-calcium carbonate grafted polycaprolactone in the homogenization section through side feeding. Extrude at a screw speed of 180 rpm and then water-cool and pelletize to obtain a modifier with a particle size of 2-3 mm.

[0040] (2) Insulating agent: Place graphite powder (D50≤5μm) in a vacuum drying oven and dry it at 80℃ and -0.08MPa for 2h. After cooling to room temperature, seal it for later use. Take 10kg of dried graphite powder and spread it evenly on the sample holder of the plasma processor. Under the conditions of vacuum degree of 0.1Pa and power of 120W, introduce oxygen at a flow rate of 5sccm and treat for 12min to obtain activated graphite. Dissolve 0.6kg of polycaprolactone with a molecular weight of 5000 in 3 Polycaprolactone ethanol solution was obtained by stirring in anhydrous ethanol for 10 min until completely dissolved. The polycaprolactone ethanol solution was injected into a reaction vessel containing activated graphite, stirred at 200 r / min, heated to 65 °C, and reacted at a constant temperature for 2.5 h. After the reaction was completed, the mixture was filtered through a Buchner funnel, the filter cake was collected, and washed three times with anhydrous ethanol. The filter cake was placed in a vacuum drying oven and dried at 80 °C and -0.08 MPa for 2 h. After cooling, it was passed through a 200-mesh sieve to obtain graphite-grafted polycaprolactone.

[0041] (3) 67.5 kg of polystyrene (HIPS) and 7.5 kg of heat insulation agent were dry-mixed at 800 rpm for 3 min, then 17 kg of modifier was added and mixed at 500 rpm for 4 min. Then 2.5 kg of talc powder and 0.5 kg of antioxidant 1010 were added and mixed for 1 min. Finally, 5.5 kg of foaming agent (2.9 kg of sodium bicarbonate and 2.6 kg of pentane) was added and mixed at 1000 rpm for 30 s to obtain a mixture. The mixture was fed into a twin-screw extruder. Under the conditions of 110°C in the feeding section, 150-160°C in the melting section, 140°C in the homogenization section, and 200 rpm in the screw speed, the molten material was extruded through the die and foamed under a pressure of 13 MPa. Then it was shaped at a cooling rate of 5°C / s to finally obtain a composite core layer with a thickness of 50 mm.

[0042] Preparation Example 2

[0043] This preparation example is basically the same as Preparation Example 1, except that: (1) Modifier: 100 kg of 50-100 nm nano-calcium carbonate was weighed and added to 400 kg of xylene. After ultrasonic dispersion at 300 W for 30 min, 12 kg of 5000 molecular weight polycaprolactone and 0.5 kg of tetrabutyl titanate catalyst were added. The mixture was heated to 100 °C and stirred for 6 h. After the reaction was completed, the mixture was filtered and vacuum dried at 80 °C for 4 h to obtain nano-calcium carbonate grafted polycaprolactone. 100 kg of linear SBS (block ratio 30:70) and 0.5 kg of antioxidant 1010 were added to a twin-screw extruder and melted according to the temperature parameters of 120 °C in the feeding section, 150-160 °C in the melting section, and 140 °C in the homogenization section. 50 kg of nano-calcium carbonate grafted polycaprolactone was added in the homogenization section by side feeding and at 180 rpm. The screw speed was adjusted, and after extrusion, the material was water-cooled and pelletized to obtain a composite with a particle size of 2-3 mm. In a nitrogen atmosphere, 6 kg of the composite and 4 kg of modified perlite were stirred at 3000 rpm for 5 min to obtain a modifier. Specifically, the modified perlite was prepared by adding 0.3 kg of KH590 mercaptosilane coupling agent to 1.2 kg of anhydrous ethanol and stirring until homogeneous to obtain a KH590 ethanol solution. 10 kg of perlite micro powder (particle size 100-200 mesh, pass rate ≥90%), KH590 ethanol solution, and 20 kg of deionized water were mixed and stirred at 60℃ and 300 rpm for 1.5 h. After stirring, the resulting mixture was centrifuged, the supernatant was discarded, and the mixture was washed with anhydrous ethanol until the washing liquid was neutral. Then, it was dried at 80℃ to constant weight to obtain modified perlite.

[0044] Preparation Example 3

[0045] This preparation example is basically the same as preparation example 2, except that: (2) heat insulation agent: the nano silica aerogel (D50=10-50nm) was dried at 100℃ and -0.09MPa for 3h, and immediately transferred to a desiccator for storage after cooling; 0.5kg of polycaprolactone with a molecular weight of 5000 was dissolved in 2L of anhydrous ethanol and stirred until dissolved; the polycaprolactone ethanol solution was added to 10kg of dried aerogel powder, stirred at 150r / min, and the temperature was controlled at 45℃ for 1.8h; the filter cake was collected by suction filtration, washed twice with anhydrous ethanol, and vacuum dried at 60℃ and -0.09MPa for 2h, and then passed through a 200-mesh sieve after cooling to obtain silica aerogel grafted with polycaprolactone.

[0046] Preparation Example 4

[0047] This preparation example is basically the same as preparation example 3, except that: (2) 7 kg of graphite-grafted polycaprolactone and 3 kg of silica aerogel-grafted polycaprolactone are stirred at 1300 r / min for 15 min, and then 0.03 kg of KH-570 silane coupling agent diluted with 0.3 L of anhydrous ethanol solution is added dropwise at a rate of 5 mL / min. After the addition is completed, stirring is continued for 20 min to obtain a mixture. The mixture is dried at 60 °C and -0.08 MPa for 1 h, and after cooling, a heat insulation agent is obtained. The preparation method of graphite-grafted polycaprolactone is the same as that of preparation example 1, and the preparation method of silica aerogel-grafted polycaprolactone is the same as that of preparation example 3.

[0048] Preparation Example 5

[0049] This preparation example discloses a composite core layer, which specifically includes the following steps:

[0050] (1) Modifier: Weigh 100 kg of 50-100 nm nano-calcium carbonate and add it to 350 kg of xylene. After ultrasonic dispersion at 300 W for 30 min, add 10 kg of 5000 molecular weight polycaprolactone and 0.4 kg of tetrabutyl titanate catalyst. Heat to 90 °C and stir for 7 h. After the reaction is complete, filter and vacuum dry at 80 °C for 4 h to obtain nano-calcium carbonate grafted polycaprolactone. Add 100 kg of linear SBS (block ratio 30:70) and 0.4 kg of antioxidant 1010 to a twin-screw extruder and melt it according to the temperature parameters of 120 °C in the feeding section, 150-160 °C in the melting section and 140 °C in the homogenization section. In the homogenization section, add 45 kg of nano-calcium carbonate grafted polycaprolactone through side feeding and stir at 180 rpm. The extruder was rotated at a certain speed, and after extrusion, it was water-cooled and pelletized to obtain a composite with a particle size of 2-3 mm. In a nitrogen atmosphere, 5 kg of the composite and 5 kg of modified perlite were stirred at 3000 rpm for 5 min to obtain a modifier. Specifically, the modified perlite was prepared by adding 0.3 kg of KH590 mercaptosilane coupling agent to 1.2 kg of anhydrous ethanol and stirring until homogeneous to obtain a KH590 ethanol solution. 10 kg of perlite powder, KH590 ethanol solution and 20 kg of deionized water were mixed and stirred at 60℃ and 300 rpm for 1.5 h. After stirring, the resulting mixture was centrifuged, the supernatant was discarded, and the mixture was washed with anhydrous ethanol until the washing liquid was neutral. Then, it was dried at 80℃ to constant weight to obtain modified perlite.

[0051] (2) Heat insulation agent: 6 kg of graphite-grafted polycaprolactone and 4 kg of silica aerogel-grafted polycaprolactone were stirred at 1300 r / min for 15 min. Then, 0.03 kg of KH-570 silane coupling agent diluted with 0.3 L of anhydrous ethanol solution was added dropwise at a rate of 5 mL / min. After the addition was completed, the mixture was stirred for 20 min to obtain a mixture. The mixture was dried at 60 °C and -0.08 MPa for 1 h. After cooling, the modifier was obtained. The preparation method of graphite-grafted polycaprolactone was the same as that of Preparation Example 1, and the preparation method of silica aerogel-grafted polycaprolactone was the same as that of Preparation Example 3.

[0052] (3) 65 kg of polystyrene (HIPS) and 5 kg of heat insulation agent were dry-mixed at 800 rpm for 3 min, then 15 kg of modifier was added and mixed at 500 rpm for 4 min. Then 2 kg of talc powder and 0.4 kg of antioxidant 1010 were added and mixed for 1 min. Finally, 5 kg of foaming agent (3 kg of sodium bicarbonate and 2 kg of pentane) was added and mixed at 1000 rpm for 30 s to obtain a mixture. The mixture was fed into a twin-screw extruder. Under the conditions of 110°C in the feeding section, 150-160°C in the melting section, 140°C in the homogenization section and 200 rpm in the screw speed, the molten material was extruded through the die and foamed under a pressure of 13 MPa. Then it was shaped at a cooling rate of 5°C / s to finally obtain a composite core layer with a thickness of 50 mm.

[0053] Preparation Example 6

[0054] This preparation example discloses a composite core layer, which specifically includes the following steps:

[0055] (1) Modifier: Weigh 100 kg of 50-100 nm nano-calcium carbonate and add it to 450 kg of xylene. After ultrasonic dispersion at 300 W for 30 min, add 14 kg of 5000 molecular weight polycaprolactone and 0.6 kg of tetrabutyl titanate catalyst. Heat to 100 °C and stir for 5 h. After the reaction is complete, filter and vacuum dry at 80 °C for 4 h to obtain nano-calcium carbonate grafted polycaprolactone. Add 100 kg of linear SBS (block ratio 30:70) and 0.6 kg of antioxidant 1010 to a twin-screw extruder and melt according to the temperature parameters of 120 °C in the feeding section, 150-160 °C in the melting section, and 140 °C in the homogenization section. In the homogenization section, add 55 kg of nano-calcium carbonate grafted polycaprolactone through side feeding and stir at 180 rpm. The screw speed was adjusted, and after extrusion, the material was water-cooled and pelletized to obtain a composite with a particle size of 2-3 mm. In a nitrogen atmosphere, 7 kg of the composite and 3 kg of modified perlite were stirred at 3000 rpm for 5 min to obtain a modifier. Specifically, the modified perlite was prepared by adding 0.3 kg of KH590 mercaptosilane coupling agent to 1.2 kg of anhydrous ethanol and stirring until homogeneous to obtain a KH590 ethanol solution. 10 kg of perlite powder, the KH590 ethanol solution, and 20 kg of deionized water were mixed and stirred at 60℃ and 300 rpm for 1.5 h. After stirring, the resulting mixture was centrifuged, the supernatant was discarded, and the mixture was washed with anhydrous ethanol until the washing liquid was neutral. The mixture was then dried at 80℃ to constant weight to obtain the modified perlite.

[0056] (2) Heat insulation agent: 8 kg of graphite-grafted polycaprolactone and 2 kg of silica aerogel-grafted polycaprolactone were stirred at 1300 r / min for 15 min. Then, 0.03 kg of KH-570 silane coupling agent diluted with 0.3 L of anhydrous ethanol solution was added dropwise at a rate of 5 mL / min. After the addition was completed, the mixture was stirred for 20 min to obtain a mixture. The mixture was dried at 60 °C and -0.08 MPa for 1 h. After cooling, the modifier was obtained. The preparation method of graphite-grafted polycaprolactone was the same as that of Preparation Example 1, and the preparation method of silica aerogel-grafted polycaprolactone was the same as that of Preparation Example 3.

[0057] (3) 70 kg of polystyrene (HIPS) and 10 kg of heat insulation agent were dry-mixed at 800 rpm for 3 min, then 19 kg of modifier was added and mixed at 500 rpm for 4 min. Then 3 kg of talc powder and 0.4 kg of antioxidant 1010 were added and mixed for 1 min. Finally, 6 kg of foaming agent (2.67 kg of sodium bicarbonate and 3.33 kg of pentane) was added and mixed at 1000 rpm for 30 s to obtain a mixture. The mixture was fed into a twin-screw extruder. Under the conditions of 110°C in the feeding section, 150-160°C in the melting section, 140°C in the homogenization section, and 200 rpm in the screw speed, the molten material was extruded through the die and foamed under a pressure of 13 MPa. Then it was shaped at a cooling rate of 5°C / s to finally obtain a composite core layer with a thickness of 50 mm.

[0058] Example 1

[0059] This embodiment provides a method for preparing lightweight thermal insulation and soundproof composite blocks, including the following steps:

[0060] Aerated concrete blocks: Dry mix 700kg of quartz sand (passing through 200 mesh with a passing rate ≥90%), 150kg of ordinary Portland cement (P·O42.5 grade), 100kg of lime (passing through 80 mesh with a passing rate ≥5%), and 0.5kg of modified fiber at 350rpm for 4min. Then add 300kg of deionized water and wet mix at 450rpm for 7min to form a slurry. Next, dilute 0.8kg of aluminum powder paste (particle size 20-50μm) with water at a ratio of 1:8 and add it to the slurry. Stir at 700rpm for 1.5min. Pour the slurry into molds and place at 25±5℃ and humidity ≥8%. The aerated concrete blocks are left to stand in a 0% environment to generate gas. Finally, the blocks are placed in an autoclave and heated to 175℃ and 0.8MPa at a rate of 10℃ / h. They are then cured at constant temperature and pressure for 12 hours. After cooling to room temperature, a 100mm thick aerated concrete block can be obtained. The modified fiber is prepared as follows: polypropylene fibers (diameter 20-30μm, length 6-12mm) are dried at 55℃ for 2 hours, then soaked in a polycaprolactone emulsion with a concentration of 8% (solid content 30%). The fibers are ultrasonically dispersed at 300W for 15 minutes. The soaked polypropylene fibers are then removed and dried at 60℃ to constant weight to obtain polycaprolactone modified polypropylene fibers.

[0061] The composite core layer was obtained from Preparation Example 1;

[0062] Polymer-modified mortar: 40 kg of ordinary Portland cement (P·O42.5 grade), 35 kg of quartz sand (passing through 200 mesh with a passing rate ≥90%), 2 kg of mercaptosilane coupling agent-modified perlite powder (the modification method is the same as that used in Preparation Example 2 for modified perlite), and 0.3 kg of hydroxypropyl methylcellulose ether (viscosity 25℃, 100,000-200,000 mPa). s) Dry mix at 350 rpm for 4 min, then add 10 kg of ethylene-vinyl acetate emulsion (solid content 40%) and 12 kg of deionized water, and wet mix at 450 rpm for 9 min to prepare a homogeneous mortar.

[0063] Next, prepare two layers of aerated concrete blocks with dimensions of 600mm×240mm×100mm (inner and outer) and a composite core layer with dimensions of 600mm×240mm×50mm. Apply a 4mm thick layer of polymer-modified mortar evenly to the bonding surface of the aerated concrete blocks. Place the composite core layer in the middle between the two layers of blocks and apply a pressure of 0.2MPa to ensure tight adhesion. Then, place it in an environment with a temperature of 25℃ and a relative humidity of ≥80% for 7 days (with the first 3 days of moist curing) to obtain a lightweight thermal insulation and sound insulation composite block.

[0064] Example 2

[0065] This embodiment is basically the same as Embodiment 1, except that the modified fiber in the aerated concrete block is prepared as follows: basalt fiber (diameter 10-20μm, length 3-6mm) is soaked in 5% hydrochloric acid solution for 30min, rinsed with deionized water until neutral, and then dried at 60℃ for 2h; using water as solvent, 1.5% KH-550 aminosilane coupling agent and 5% ethylene-vinyl acetate emulsion (solid content 40%) are added, stirred evenly, and the pretreated basalt fiber is completely immersed in the mixture, stirred at room temperature for 20min and ultrasonically treated at 300W power for 15min, the impregnated basalt fiber is taken out and dried at 70℃ to constant weight to obtain ethylene-vinyl acetate modified basalt fiber.

[0066] Example 3

[0067] This embodiment is basically the same as Embodiment 2, except that the modified fibers in the aerated concrete blocks are 0.3 kg of polycaprolactone-modified polypropylene fiber (preparation method is the same as in Embodiment 1) and 0.2 kg of ethylene-vinyl acetate-modified basalt fiber (preparation method is the same as in Embodiment 2).

[0068] Example 4

[0069] This embodiment provides a method for preparing lightweight thermal insulation and soundproof composite blocks, including the following steps:

[0070] Aerated concrete blocks: Dry mix 650kg of quartz sand (passing through 200 mesh with a passing rate ≥90%), 120kg of ordinary Portland cement (P·O42.5 grade), 110kg of lime (passing through 80 mesh with a passing rate ≥5%), and 0.7kg of modified fiber at 350rpm for 4min. Then add 330kg of deionized water and wet mix at 450rpm for 7min to form a slurry. Subsequently, dilute 1kg of aluminum powder paste (particle size 20-50μm) with water at a ratio of 1:8 and add it to the slurry. Mix at 700rpm. After stirring for 1.5 minutes, the slurry was poured into a mold and placed in an environment of 25±5℃ and ≥80% humidity for static gas generation. Finally, the green body was placed in an autoclave and heated to 175℃ and 0.8MPa at a rate of 10℃ / h. It was then cured at constant temperature and pressure for 12 hours. After cooling to room temperature, a 100mm thick aerated concrete block was obtained. The modified fibers were 0.49kg of polycaprolactone-modified polypropylene fiber (preparation method as in Example 1) and 0.21kg of ethylene-vinyl acetate-modified basalt fiber (preparation method as in Example 2).

[0071] The composite core layer was obtained from Preparation Example 1;

[0072] Polymer-modified mortar: 42.5 kg of ordinary Portland cement (P·O 42.5 grade), 37.5 kg of quartz sand (passing through 200 mesh with a passing rate ≥90%), 2.5 kg of perlite powder modified with mercaptosilane coupling agent (the modification method is the same as that used in Preparation Example 2 for modified perlite), and 0.4 kg of hydroxypropyl methylcellulose ether (viscosity 25℃, 100,000-200,000 mPa) were prepared. s) Dry mix at 350 rpm for 4 min, then add 11 kg of ethylene-vinyl acetate emulsion (solid content 40%) and 13 kg of deionized water, and wet mix at 450 rpm for 9 min to prepare a homogeneous mortar.

[0073] Next, prepare two layers of aerated concrete blocks with dimensions of 600mm×240mm×100mm (inner and outer) and a composite core layer with dimensions of 600mm×240mm×50mm. Apply a 4mm thick layer of polymer-modified mortar evenly to the bonding surface of the aerated concrete blocks. Place the composite core layer in the middle between the two layers of blocks and apply a pressure of 0.2MPa to ensure tight adhesion. Then, place it in an environment with a temperature of 25℃ and a relative humidity of ≥80% for 7 days (with the first 3 days of moist curing) to obtain a lightweight thermal insulation and sound insulation composite block.

[0074] Example 5

[0075] This embodiment provides a method for preparing lightweight thermal insulation and soundproof composite blocks, including the following steps:

[0076] Aerated concrete blocks: Dry mix 750kg of quartz sand (passing through 200 mesh with a passing rate ≥90%), 180kg of ordinary Portland cement (P·O42.5 grade), 120kg of lime (passing through 80 mesh with a passing rate ≥5%), and 0.8kg of modified fiber at 350rpm for 4min. Then add 357kg of deionized water and wet mix at 450rpm for 7min to form a slurry. Subsequently, dilute 1.2kg of aluminum powder paste (particle size 20-50μm) with water at a ratio of 1:8 and add it to the slurry. Mix at 700rpm. After stirring for 1.5 minutes, the slurry is poured into a mold and placed in an environment of 25±5℃ and ≥80% humidity for static gas generation. Finally, the green body is placed in an autoclave and heated to 175℃ and 0.8MPa at a rate of 10℃ / h, and cured at constant temperature and pressure for 12 hours. After cooling to room temperature, a 100mm thick aerated concrete block is obtained. The modified fiber consists of 0.64kg of polycaprolactone-modified polypropylene fiber (preparation method as in Example 1) and 0.16kg of ethylene-vinyl acetate-modified basalt fiber (preparation method as in Example 2).

[0077] The composite core layer was obtained from Preparation Example 1;

[0078] Polymer-modified mortar: 45 kg of ordinary Portland cement (P·O42.5 grade), 40 kg of quartz sand (passing through 200 mesh with a passing rate ≥90%), 3 kg of perlite powder modified with mercaptosilane coupling agent (the modification method is the same as that used in Preparation Example 2 for modified perlite), and 0.5 kg of hydroxypropyl methylcellulose ether (viscosity 25℃, 100,000-200,000 mPa). s) Dry mix at 350 rpm for 4 min, then add 12 kg of ethylene-vinyl acetate emulsion (solid content 40%) and 14 kg of deionized water, and wet mix at 450 rpm for 9 min to prepare a homogeneous mortar.

[0079] Next, prepare two layers of aerated concrete blocks with dimensions of 600mm×240mm×100mm (inner and outer) and a composite core layer with dimensions of 600mm×240mm×50mm. Apply a 4mm thick layer of polymer-modified mortar evenly to the bonding surface of the aerated concrete blocks. Place the composite core layer in the middle between the two layers of blocks and apply a pressure of 0.2MPa to ensure tight adhesion. Then, place it in an environment with a temperature of 25℃ and a relative humidity of ≥80% for 7 days (with the first 3 days of moist curing) to obtain a lightweight thermal insulation and sound insulation composite block.

[0080] Example 6

[0081] This embodiment is basically the same as Example 4, except that the composite core layer is the one obtained in Preparation Example 2.

[0082] Example 7

[0083] This embodiment is basically the same as Example 4, except that the composite core layer is the one obtained in Preparation Example 3.

[0084] Example 8

[0085] This embodiment is basically the same as Example 4, except that the composite core layer is the one obtained in Example 4.

[0086] Example 9

[0087] This embodiment is basically the same as Example 4, except that the composite core layer is the one obtained in Preparation Example 5.

[0088] Example 10

[0089] This embodiment is basically the same as Example 4, except that the composite core layer is the one obtained in Preparation Example 6.

[0090] Comparative Example 1

[0091] This comparative example provides a lightweight thermal insulation and soundproof composite block, including the following steps:

[0092] Aerated concrete blocks: 700 kg of quartz sand (passing through a 200-mesh sieve with a passing rate ≥90%), 150 kg of ordinary Portland cement (P·O42.5 grade), 100 kg of lime (passing through an 80-mesh sieve with a passing rate ≥5%), and 0.5 kg of polypropylene fiber (diameter 20-30 μm, length 6-12 mm) are dry-mixed at 350 rpm for 4 minutes. Then, 300 kg of deionized water is added and wet-mixed at 450 rpm for 7 minutes to form a slurry. Then, 0.8 kg of aluminum powder paste (particle size 20-50 μm) is diluted with water at a ratio of 1:8 and added to the slurry. The mixture is stirred at 700 rpm for 1.5 min. The slurry is poured into a mold and placed in an environment of 25±5℃ and humidity ≥80% to allow it to stand and generate gas. Finally, the green body is placed in an autoclave and heated to 175℃ and 0.8 MPa at a rate of 10℃ / h. It is then cured at constant temperature and pressure for 12 h. After cooling to room temperature, a 100 mm thick aerated concrete block can be obtained.

[0093] The composite core layer was obtained from Preparation Example 1;

[0094] Polymer-modified mortar: 40 kg of ordinary Portland cement (P·O42.5 grade), 35 kg of quartz sand (passing through 200 mesh with a passing rate ≥90%), 2 kg of mercaptosilane coupling agent-modified perlite powder (the modification method is the same as that used in Preparation Example 2 for modified perlite), and 0.3 kg of hydroxypropyl methylcellulose ether (viscosity 25℃, 100,000-200,000 mPa). s) Dry mix at 350 rpm for 4 min, then add 10 kg of ethylene-vinyl acetate emulsion (solid content 40%) and 12 kg of deionized water, and wet mix at 450 rpm for 9 min to prepare a homogeneous mortar.

[0095] Next, prepare two layers of aerated concrete blocks with dimensions of 600mm×240mm×100mm (inner and outer) and a composite core layer with dimensions of 600mm×240mm×50mm. Apply a 4mm thick layer of polymer-modified mortar evenly to the bonding surface of the aerated concrete blocks. Place the composite core layer in the middle between the two layers of blocks and apply a pressure of 0.2MPa to ensure tight adhesion. Then, place it in an environment with a temperature of 25℃ and a relative humidity of ≥80% for 7 days (with the first 3 days of moist curing) to obtain a lightweight thermal insulation and sound insulation composite block.

[0096] Comparative Example 2

[0097] This comparative example provides a method for preparing a lightweight thermal insulation and soundproof composite block, including the following steps:

[0098] Aerated concrete blocks: Dry mix 700kg of quartz sand (passing through 200 mesh with a passing rate ≥90%), 150kg of ordinary Portland cement (P·O42.5 grade), 100kg of lime (passing through 80 mesh with a passing rate ≥5%), and 0.5kg of modified fiber at 350rpm for 4min. Then add 300kg of deionized water and wet mix at 450rpm for 7min to form a slurry. Next, dilute 0.8kg of aluminum powder paste (particle size 20-50μm) with water at a ratio of 1:8 and add it to the slurry. Stir at 700rpm for 1.5min. Pour the slurry into molds and place at 25±5℃ and humidity ≥8%. The aerated concrete blocks are left to stand in a 0% environment to generate gas. Finally, the blocks are placed in an autoclave and heated to 175℃ and 0.8MPa at a rate of 10℃ / h. They are then cured at constant temperature and pressure for 12 hours. After cooling to room temperature, a 100mm thick aerated concrete block can be obtained. The modified fiber is prepared as follows: polypropylene fibers (diameter 20-30μm, length 6-12mm) are dried at 55℃ for 2 hours, then soaked in a polycaprolactone emulsion with a concentration of 8% (solid content 30%). The fibers are ultrasonically dispersed at 300W for 15 minutes. The soaked polypropylene fibers are then removed and dried at 60℃ to constant weight to obtain polycaprolactone modified polypropylene fibers.

[0099] Composite core layer: 67.5 kg of polystyrene (HIPS) and 7.5 kg of graphite (D50≤5μm) were dry-mixed at 800 rpm for 3 min. Then, 2.5 kg of talc powder and 0.5 kg of antioxidant 1010 were added and mixed for another 1 min. Finally, 5.5 kg of foaming agent (2.9 kg of sodium bicarbonate and 2.6 kg of pentane) were added and mixed at 1000 rpm for 30 s to obtain a mixture. The mixture was fed into a twin-screw extruder. Under the conditions of 110℃ in the feeding section, 150-160℃ in the melting section, 140℃ in the homogenization section, and a screw speed of 200 rpm, the molten material was extruded through the die and foamed under a pressure of 13 MPa. Then, it was shaped by cooling at a rate of 5℃ / s to finally obtain a composite core layer with a thickness of 50 mm.

[0100] Polymer-modified mortar: 40 kg of ordinary Portland cement (P·O42.5 grade), 35 kg of quartz sand (passing through 200 mesh with a passing rate ≥90%), 2 kg of mercaptosilane coupling agent-modified perlite powder (the modification method is the same as that used in Preparation Example 2 for modified perlite), and 0.3 kg of hydroxypropyl methylcellulose ether (viscosity 25℃, 100,000-200,000 mPa). s) Dry mix at 350 rpm for 4 min, then add 10 kg of ethylene-vinyl acetate emulsion (solid content 40%) and 12 kg of deionized water, and wet mix at 450 rpm for 9 min to prepare a homogeneous mortar.

[0101] Next, prepare two layers of aerated concrete blocks with dimensions of 600mm×240mm×100mm (inner and outer) and a composite core layer with dimensions of 600mm×240mm×50mm. Apply a 4mm thick layer of polymer-modified mortar evenly to the bonding surface of the aerated concrete blocks. Place the composite core layer in the middle between the two layers of blocks and apply a pressure of 0.2MPa to ensure tight adhesion. Then, place it in an environment with a temperature of 25℃ and a relative humidity of ≥80% for 7 days (with the first 3 days of moist curing) to obtain a lightweight thermal insulation and sound insulation composite block.

[0102] Comparative Example 3

[0103] This embodiment provides a method for preparing lightweight thermal insulation and soundproof composite blocks, including the following steps:

[0104] Aerated concrete blocks: Dry mix 700kg of quartz sand (passing through 200 mesh with a passing rate ≥90%), 150kg of ordinary Portland cement (P·O42.5 grade), 100kg of lime (passing through 80 mesh with a passing rate ≥5%), and 0.5kg of modified fiber at 350rpm for 4min. Then add 300kg of deionized water and wet mix at 450rpm for 7min to form a slurry. Next, dilute 0.8kg of aluminum powder paste (particle size 20-50μm) with water at a ratio of 1:8 and add it to the slurry. Stir at 700rpm for 1.5min. Pour the slurry into molds and place at 25±5℃ and humidity ≥8%. The aerated concrete blocks are left to stand in a 0% environment to generate gas. Finally, the blocks are placed in an autoclave and heated to 175℃ and 0.8MPa at a rate of 10℃ / h. They are then cured at constant temperature and pressure for 12 hours. After cooling to room temperature, a 100mm thick aerated concrete block can be obtained. The modified fiber is prepared as follows: polypropylene fibers (diameter 20-30μm, length 6-12mm) are dried at 55℃ for 2 hours, then soaked in a polycaprolactone emulsion with a concentration of 8% (solid content 30%). The fibers are ultrasonically dispersed at 300W for 15 minutes. The soaked polypropylene fibers are then removed and dried at 60℃ to constant weight to obtain polycaprolactone modified polypropylene fibers.

[0105] The composite core layer was obtained from Preparation Example 1;

[0106] Modified mortar: 40 kg ordinary Portland cement (P·O42.5 grade), 35 kg quartz sand (passing through 200 mesh with a passing rate ≥90%), 2 kg perlite powder (particle size 100-200 mesh, passing rate ≥90%), and 0.3 kg hydroxypropyl methylcellulose ether (viscosity 25℃, 100,000-200,000 mPa). s) Dry mix at 350 rpm for 4 min, then add 12 kg of deionized water and wet mix at 450 rpm for 9 min to make a homogeneous mortar.

[0107] Next, prepare two layers of aerated concrete blocks with dimensions of 600mm×240mm×100mm (inner and outer) and a composite core layer with dimensions of 600mm×240mm×50mm. Apply a 4mm thick layer of modified mortar evenly to the bonding surface of the aerated concrete blocks. Place the composite core layer in the middle between the two layers of blocks and apply a pressure of 0.2MPa to ensure tight adhesion. Then, place it in an environment with a temperature of 25℃ and a relative humidity of ≥80% for 7 days (with the first 3 days of moist curing) to obtain a lightweight thermal insulation and sound insulation composite block.

[0108] Performance testing

[0109] Thermal conductivity (25℃): GB / T10294-2008;

[0110] In accordance with the above testing standards, the thermal insulation performance of the composite core layers prepared in Examples 1-6 was tested, and the test results are recorded in Table 1.

[0111] Bulk density: GB / T11968-2020;

[0112] Airborne sound insulation (100-3150Hz): GB / T50121-2005;

[0113] Interfacial bond strength: GB / T25181-2010;

[0114] Drying shrinkage rate (28d): GB / T23451-2009;

[0115] Compressive strength (28d): GB / T11968-2020;

[0116] Freeze-thaw resistance (25 freeze-thaw cycles): GB / T11969-2008.

[0117] In accordance with the above testing standards, the lightweight thermal insulation and sound insulation composite blocks obtained in Examples 1-10 and Comparative Examples 1-3 were subjected to performance tests. The test results are shown in Tables 2 and 3.

[0118] Table 1. Thermal insulation performance test data of composite core layers in Examples 1-6

[0119]

[0120] Table 2 Performance test data of lightweight thermal insulation and soundproofing composite blocks in Examples 1-10 and Comparative Examples 1-3

[0121]

[0122] Table 3 Performance test data of lightweight thermal insulation and soundproofing composite blocks in Examples 1-10 and Comparative Examples 1-3

[0123]

[0124] Combining Example 1 and Comparative Example 1 with reference to Tables 1-3, it can be seen that Example 1 uses polycaprolactone-modified polypropylene fibers. The ester groups on the surface of these fibers can form a chemical bond with the hydration products of the aerated concrete matrix and the organic components of the composite core layer. At the same time, the flexible chain segments buffer the interfacial stress, which not only avoids the thermal and acoustic bridging problems caused by interfacial gaps, but also enhances the overall structural integrity and crack resistance. In contrast, Comparative Example 1 uses ordinary unmodified polypropylene fibers, which can only achieve basic physical dispersion and cannot build a stable chemical bond. It is prone to defects such as shrinkage cracking and peeling due to weak interfacial bonding. Consequently, the overall lightweight characteristics, thermal insulation effect, sound insulation performance, structural strength, and freeze-thaw durability are all inferior to those of Example 1. This fully demonstrates the multi-dimensional optimization effect of modified fibers on the comprehensive performance of masonry blocks from the perspectives of chemical bonding, stress buffering, and structural stability.

[0125] Combining Example 1 and Comparative Example 2 and referring to Tables 1-3, it can be seen that the composite core layer of Example 1, combined with a special modifier and graphite-grafted polycaprolactone thermal insulation agent, can form a chemical bond between the core layer and the aerated concrete matrix. The grafted graphite can avoid agglomeration and uniformly disperse to form a continuous thermal and sound insulation barrier, reducing the generation of thermal and acoustic bridges. However, the composite core layer of Comparative Example 2 lacks a special modifier and uses ordinary graphite without polycaprolactone grafting. It can only rely on physical bonding to achieve the connection between the core layer and the matrix. The graphite is prone to agglomeration, resulting in blind spots in thermal and sound insulation, and the interface bonding lacks chemical support. This makes Example 1 superior in terms of thermal insulation, sound insulation and noise reduction, with a more stable interface connection, less shrinkage deformation, no peeling or blistering during freeze-thaw cycles, and better structural stability and durability. In contrast, Comparative Example 2, due to insufficient optimization of the core layer composition, not only has limited thermal insulation and sound insulation performance, but also suffers from defects such as localized blistering at the interface, high shrinkage rate, and poor freeze-thaw resistance, failing to meet the comprehensive performance requirements of composite blocks.

[0126] Combining Example 1 and Comparative Example 3 and referring to Tables 1-3, it can be seen that Example 1 uses polymer-modified mortar containing ethylene-vinyl acetate emulsion and mercaptosilane coupling agent modified perlite as the bonding layer. The mercaptosilane coupling agent can achieve bidirectional chemical bridging between the aerated concrete matrix and the composite core layer. The ethylene-vinyl acetate emulsion and the organic components of the core layer are homologous and compatible. It can also optimize water retention and control shrinkage through cellulose ether, so that the interface forms a stable chemical bond and physical adhesion, effectively avoiding the formation of gaps. In contrast, Comparative Example 3 uses ordinary cement mortar without any modified components. It only relies on cement hydration products to achieve simple physical adhesion with the matrix and core layer. It lacks chemical synergy and is prone to interfacial gaps due to inconsistent shrinkage. This makes the interface connection of Example 1 more robust, without peeling, cracking or other problems, resulting in better thermal insulation and sound insulation performance, less shrinkage deformation, and superior compressive strength and freeze-thaw resistance. In contrast, Comparative Example 3, due to the inability of the adhesive layer to solve the bonding problem of the inorganic-organic interface, not only is the interface prone to obvious peeling, but also thermal and acoustic bridges are formed due to gaps, leading to a significant decrease in thermal insulation and sound insulation performance, higher shrinkage rate, and significant deterioration in compressive strength and freeze-thaw resistance, which cannot meet the structural stability and comprehensive use requirements of composite blocks.

[0127] This specific embodiment is merely an explanation of this application and is not intended to limit it. After reading this specification, those skilled in the art can make modifications to this embodiment without contributing any inventive step, but such modifications are protected by patent law as long as they fall within the scope of the claims of this application.

Claims

1. An aerated concrete block, characterized in that, The raw materials include the following parts by weight: 120-180 parts of ordinary silicate cement, 100-120 parts of lime, 650-750 parts of quartz sand, 0.8-1.2 parts of aluminum powder paste, 0.5-0.8 parts of modified fiber, and 300-357 parts of water; the modified fiber is a mixture of polycaprolactone-modified polypropylene fiber and ethylene-vinyl acetate-modified basalt fiber in a mass ratio of (6-8):(2-4). The preparation method of the polycaprolactone-modified polypropylene fiber is as follows: Polypropylene fibers are dried at 55℃ for 2 hours, then immersed in an 8% polycaprolactone emulsion, and ultrasonically dispersed at 300W for 15 minutes. The immersed polypropylene fibers are then removed and dried at 60℃ to constant weight to obtain the polycaprolactone-modified polypropylene fiber. The diameter of the polypropylene fiber is 20-30 μm, and the length is 6-12 mm. The solid content of the polycaprolactone emulsion is 30%. The preparation method of the ethylene-vinyl acetate modified basalt fiber is as follows: basalt fiber is immersed in a 5% hydrochloric acid solution for 30 minutes, then rinsed with deionized water until neutral, and subsequently dried at 60°C for 2 hours; using water as a solvent, 1.5% KH-550 aminosilane coupling agent and 5% ethylene-vinyl acetate emulsion are added, stirred evenly, and the pretreated basalt fiber is completely immersed in the mixture. The mixture is stirred at room temperature for 20 minutes and simultaneously ultrasonically treated at 300W power for 15 minutes. The immersed basalt fiber is then removed and dried at 70°C to constant weight to obtain the ethylene-vinyl acetate modified basalt fiber; the diameter of the basalt fiber is 10-20 μm and the length is 3-6 mm; the solid content of the ethylene-vinyl acetate emulsion is 40%.

2. A lightweight thermal insulation and soundproof composite block, characterized in that, It includes two layers of aerated concrete blocks as described in claim 1, and a composite core layer sandwiched between the two layers of aerated concrete blocks.

3. The lightweight thermal insulation and soundproof composite block according to claim 2, characterized in that, The composite core layer comprises the following raw materials in parts by weight: 65-70 parts polystyrene, 5-10 parts heat insulation agent, 5-6 parts foaming agent, 2-3 parts talc powder, and 15-19 parts modifier. The preparation method of the modifier includes the following steps: (1) Add 100 parts by weight of nano-calcium carbonate to 350-450 parts by weight of xylene, disperse by ultrasonication, then add 10-14 parts by weight of polycaprolactone and 0.4-0.6 parts by weight of tetrabutyl titanate, heat to 90-100℃ and stir for 5-7 hours. After the reaction is completed, filter and dry to obtain nano-calcium carbonate grafted with polycaprolactone. (2) 100 parts by weight of linear SBS and 0.4-0.6 parts by weight of antioxidant 1010 are melted together, and 45-55 parts by weight of nano-calcium carbonate grafted polycaprolactone are added. The mixture is then extruded and granulated to obtain the composite.

4. The lightweight thermal insulation and soundproof composite block according to claim 3, characterized in that, The preparation method of the modifier further includes step (3), which is: mixing the composite with modified perlite in a mass ratio of (5-7):(3-5) to obtain the modifier; the modified perlite is obtained by modifying perlite micro powder with mercaptosilane coupling agent.

5. The lightweight thermal insulation and soundproof composite block according to claim 3, characterized in that, The foaming agent is a mixture of sodium bicarbonate and pentane in a mass ratio of (4-6):(4-5).

6. The lightweight thermal insulation and soundproof composite block according to claim 3, characterized in that, The heat insulation agent is obtained by grafting polycaprolactone onto the surface of the heat insulation material; the heat insulation material is graphite and / or nano-silica aerogel.

7. The lightweight thermal insulation and soundproof composite block according to claim 6, characterized in that, The heat insulation agent is a mixture of graphite-grafted polycaprolactone and nano-silica aerogel-grafted polycaprolactone in a mass ratio of (6-8):(2-4).

8. The lightweight thermal insulation and soundproof composite block according to claim 2, characterized in that, The aerated concrete blocks and the composite core layer are bonded together by polymer-modified mortar.

9. The lightweight thermal insulation and soundproof composite block according to claim 8, characterized in that, The polymer-modified mortar comprises the following raw materials in parts by weight: 40-45 parts of ordinary silicate cement, 35-40 parts of quartz sand, 10-12 parts of ethylene-vinyl acetate emulsion, 2-3 parts of perlite micro powder modified with mercaptosilane coupling agent, 0.3-0.5 parts of cellulose ether, and 12-14 parts of water.

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