A full-precast light steel keel intelligent composite wall and a preparation method thereof

Abstract

This invention discloses a fully prefabricated lightweight steel keel intelligent composite wall and its preparation method, comprising four parts: a UHPC decorative thin panel system, a modified lightweight steel keel gradient interlocking structure, a lightweight concrete phase change matrix, and intelligent sensing nodes. The lightweight concrete phase change matrix has the following composition: 95-120 parts ordinary Portland cement, 20-40 parts fly ash, 5-15 parts granulated blast furnace slag powder, 20-35 parts highly active rice husk ash, 40-70 parts expanded vitrified microspheres, 8-20 parts microencapsulated phase change material, 3-10 parts nano-aerogel particles, 1-4 parts modified waste PET fiber, 1.0-3.5 parts polycarboxylate-based high-efficiency water-reducing agent, 0.1-0.5 parts tartaric acid, and 30-55 parts water. The composite wall exhibits a compressive strength of 5.4 MPa or higher and a dry density of less than 840 kg / m³. 3 The heat transfer coefficient (K value) is less than 0.35 W / (m²). 2 It has a fire resistance rating of A2 and a sound insulation rating of 6, and excellent durability. The fully prefabricated light steel keel intelligent composite wall system can be prefabricated in the factory and directly assembled on-site.

Description

Technical Field

[0001] This invention relates to the field of building industrialization and high-performance building envelope technology, specifically to a fully prefabricated light steel keel intelligent composite wall system that integrates ultra-high performance, intelligent sensing and green low carbon. Background Technology

[0002] With the development of prefabricated buildings, the performance requirements for building envelopes have evolved from a single structural enclosure to a combination of high durability, high decoration, intelligence and low carbon. Existing prefabricated light steel walls often face the following bottlenecks: (1) The material system has a single function and lacks intelligent response capability: Existing walls are mostly focused on structural load-bearing, basic insulation (rock wool, polystyrene board, etc.) and static decoration. They cannot actively adjust the indoor thermal comfort according to changes in the external environment (such as temperature difference), nor can they perceive and warn of their own structural health in real time; (2) The structure-function synergy is insufficient and there are performance shortcomings: The performance improvement of traditional insulation materials is limited and there is a thermal bridge effect. Simply increasing the thickness is not economical, which makes it difficult to break through the overall heat transfer coefficient (K value) of the wall and cannot easily meet the requirements of ultra-low energy consumption buildings; (3) It is difficult to balance green and low carbon with high performance: Many solutions rely on high energy consumption and high carbon emission cement-based materials to achieve high performance (such as high strength and thinness). At the same time, the high-value-added and high-performance utilization of bulk solid waste (such as fly ash and rice husk ash) in the wall is limited, and the "green" and "high-performance" are not deeply integrated; (4) Production process and cost constraints: Some on-site composite processes have problems such as many procedures, long construction period and quality dependence on workers' skills, which can easily lead to cracking of board joints. Although the application of high-performance materials such as UHPC is good, if the cost cannot be optimized through system innovation (such as intelligent material reduction), it will restrict its market promotion.

[0003] Based on this, we are now studying a precast wall preparation method that is comprehensively innovative from the material source to the structural construction and system function. Summary of the Invention

[0004] Purpose of the invention: This invention aims to overcome the deficiencies of existing technologies and provide a fully prefabricated light steel keel intelligent composite wall and its preparation method. The wall consists of four parts: a UHPC decorative thin panel system, a modified light steel keel gradient interlocking structure, a lightweight concrete phase change matrix, and intelligent sensing nodes, achieving a deep integration of ultra-high performance, long-term durability, intelligent sensing, and green low-carbon features.

[0005] Technical solution A fully prefabricated light steel keel intelligent composite wall system, characterized in that it comprises, from the outside to the inside: (1) UHPC decorative thin panel system: As the exterior cladding and first protective layer of the wall, it is prefabricated from ultra-high performance concrete with a thickness of 10-25mm. Three-dimensional deformable flexible connectors are pre-embedded on its interior side. The thin panel has extremely high compressive strength (≥100MPa), flexural toughness and excellent impermeability, frost resistance and corrosion resistance.

[0006] (2) Modified light steel keel frame: It is made of keel formed by cold bending of aluminum zinc plate. Its web and wing plates are stamped with asymmetrical gradient tooth-shaped holes or protrusions. The size and density of the teeth change in a gradient along the length direction, and are most dense at the ends and connection areas.

[0007] (3) Lightweight concrete phase change matrix: It is formed by high pressure injection process and modified light steel keel skeleton, and the skeleton is completely covered to form the main structural layer.

[0008] (4) Intelligent sensing and connection nodes: Intelligent nodes with shape memory alloy (SMA) limit pins and fiber optic grating (FBG) sensors are prefabricated around the keel frame for connection with adjacent components and real-time monitoring of internal strain and temperature.

[0009] One end of the three-dimensional deformable flexible connector is anchored inside the UHPC decorative sheet, and the other end is reliably connected to the modified light steel keel frame through an adjustable mechanical connection. This forms a stress-relieving layer between the decorative sheet and the main substrate that allows for slight relative displacement due to temperature and humidity changes, ensuring that the two work together without cracking during long-term use.

[0010] This invention also provides a method for preparing the above-mentioned lightweight concrete phase change matrix, comprising the following steps: (1) Raw material pretreatment: ordinary silicate cement, fly ash, granulated blast furnace slag powder, and high-activity rice husk ash are mixed in a dry state for 5-8 minutes to form a uniform composite cementitious powder A; nano aerogel particles are premixed with a small amount of expanded vitrified microspheres for 1-2 minutes to form lightweight functional aggregate B; water, water-reducing agent and tartaric acid are mixed evenly in a mixing pot, and all the composite cementitious powder A is added and stirred to form a uniform slurry C.

[0011] (2) Refined composite of functional materials and aggregates: Modified waste PET fibers (dispersed and stirred for 1-2 min) and microencapsulated phase change materials (gently stirred for 2-4 min until uniformly dispersed) are added sequentially to activated slurry C. Then, the remaining expanded vitrified microspheres and premixed lightweight functional aggregates B are added in two batches, using a "spreading-cutting" stirring method until the aggregates are completely coated by the slurry and evenly distributed. The total stirring time should be strictly controlled within 10-15 min to prevent the lightweight aggregates from floating or breaking.

[0012] (3) Casting: The prepared lightweight concrete phase change matrix slurry is injected into a sealed mold with a built-in modified light steel keel frame through a high-pressure injection device. The injection pressure is 0.4-1.0 MPa and the injection speed is 0.5-2.0 L / s to ensure that the slurry can fully fill the gradient toothed structure and expel air. After casting, the mold is subjected to low-frequency micro-amplitude vibration (frequency 30-50 Hz, time 30-60 s) to assist in final compaction.

[0013] (4) Curing: Move the mold to the curing kiln and steam it for 12-16 hours at (60±5)℃ and ≥95% humidity. Then switch to constant temperature sealed curing at (20±5)℃ for more than 7 days.

[0014] Beneficial effects: Compared with the prior art, the significant advantages of the present invention are: (1) Performance leap and long-term durability: UHPC decorative thin panels provide extraordinary mechanical properties, weather resistance and rich decorative possibilities, realizing the same lifespan for the surface and structure. The flexible connection system completely solves the problem of deformation coordination between heterogeneous materials. (2) Structural integration and high strength and lightweight: The "gradient interlocking structure" makes the light steel keel and bio-based concrete form a highly mechanically interlocked integrated composite load-bearing body, significantly improving the overall stiffness and shear strength, and the wall maintains lightweight while achieving high performance. (3) Green and low carbon and intelligent temperature regulation: The lightweight concrete phase change matrix makes extensive use of solid waste such as rice husk ash, fly ash, and granulated blast furnace slag powder. The addition of microencapsulated phase change materials and nano aerogels gives the wall "thermal inertia" and ultra-high thermal insulation, significantly reducing building energy consumption. (4) Intelligent Sensing and High-Efficiency Prefabrication: The built-in SMA and FBG sensors together constitute the "sensory nerves" and "conditioned reflex muscles" of the wall intelligent system. When an external force (such as an earthquake) acts on the wall, the FBG sensor first senses the strain change on the keel and issues an early warning signal. At the same time, the SMA limit pins activate, consuming a large amount of input energy through hyperelastic deformation and limiting displacement. After the external force ends, the SMA limit pins drive the wall to return to its original position; meanwhile, the FBG sensor continuously monitors the reset process and residual deformation, verifies the reset effect, and provides data for maintenance decisions, greatly improving the safety and toughness of the building. All components of this invention are prefabricated with high precision in the factory, allowing for quick on-site installation and controllable quality. Attached Figure Description

[0015] Figure 1 This is a schematic cross-sectional view of the three-dimensional wall structure of the present invention.

[0016] Figure 2 A cross-sectional view AA of the gradient toothed structure of the main keel of the modified light steel keel.

[0017] Figure 3 Cross-sectional view of a three-dimensional deformable flexible connector pre-embedded in a UHPC thin sheet.

[0018] Figure 4 Positioning of SMA limit pins and FBG sensor smart nodes. Detailed Implementation

[0019] The technical solution of the present invention will be further described in detail below with reference to the embodiments.

[0020] It should be noted that the shape memory alloy (SMA) limiting pins and fiber optic grating (FBG) sensors are both integrated into the four connecting nodes of the modified light steel keel frame during the factory prefabrication stage. Specifically, the SMA limiting pins are fixed to the connecting plates at the ends of the keel, while the FBG sensors are attached to key stress-bearing parts of the main keel and the top and bottom keels. All sensing circuits converge to a junction box pre-embedded in the side of the wall panel.

[0021] Example 1 A fully prefabricated light steel keel intelligent composite wall system consists of the following components: (1) Prefabrication of UHPC decorative thin plate: Prefabricate UHPC decorative thin plate with a width of 3000mm, a height of 4200mm and a thickness of 25mm, and embed 8 three-dimensional deformable stainless steel flexible connectors on the inner side, allowing in-plane displacement of ±1.5mm.

[0022] (2) Preparation of modified light steel keel frame: 1.2mm thick aluminum zinc plate, 12 trapezoidal teeth with a depth of 1.5mm are stamped on the web of C-shaped keel within 200mm of the end, and 6 trapezoidal teeth with a depth of 1.0mm are in the middle area. Smart nodes for fixing SMA limit pins and 4 FBG sensors are pre-embedded around the frame.

[0023] (3) Preparation of lightweight concrete phase change matrix: Table 1. Component content of the phase change matrix in lightweight concrete of Example 1 Serial Number Components Content / serving 1 Ordinary Portland cement 100 2 fly ash 21 3 Granulated blast furnace slag powder 9 4 Highly active rice husk ash 25 5 Expanded vitrified microspheres 60 6 Microencapsulated phase change materials (phase change temperature 25℃) 18 7 Nano aerogel particles 6 8 Modified waste PET fiber 2 9 Polycarboxylate superplasticizer 2.2 10 tartaric acid 0.2 11 water 35 The lightweight concrete phase change matrix of Example 1 was prepared by the following steps: ① Raw material pretreatment: Mix ordinary silicate cement, fly ash, granulated blast furnace slag powder, and highly active rice husk ash in a dry state for 5 minutes to form a uniform composite cementitious powder A; premix nano aerogel particles with a small amount of expanded vitrified microspheres for 2 minutes to form lightweight functional aggregate B; mix water, water-reducing agent, and tartaric acid evenly in a mixing pot, and add all of the composite cementitious powder A, stirring to form a uniform slurry C.

[0024] ② Refined compounding of functional materials and aggregates: Modified waste PET fibers are added sequentially to activated slurry C (dispersed and stirred for 1 min), followed by microencapsulated phase change material (gently stirred for 2 min until uniformly dispersed). Then, the remaining expanded vitrified microspheres and premixed lightweight functional aggregate B are added in two batches, using a "spreading-cutting" stirring method until the aggregate is completely coated by the slurry and evenly distributed. The total stirring time should be strictly controlled within 10 min to prevent the lightweight aggregate from floating or breaking.

[0025] ③ Pouring: The prepared lightweight concrete phase change matrix slurry is injected into a sealed mold with a built-in modified light steel keel frame using a high-pressure injection device. The injection pressure is 0.7 MPa and the injection speed is 1.2 L / s to ensure that the slurry can fully fill the gradient toothed structure and expel air. After pouring, the mold is subjected to low-frequency micro-vibration (frequency 40 Hz, time 45 s) to assist in final compaction.

[0026] ④ Curing: Move the mold to the curing kiln and steam it for 16 hours at 65℃ and ≥95% humidity. After demolding, seal and cure it for 7 days at a constant temperature of (20±5)℃.

[0027] (4) Wall connection and post-treatment: Secure the connectors on the inside of the UHPC sheet to the light steel keel with nuts and adjust them to the designed position. Integrate the system wiring and seal the surface joints.

[0028] Example 2 A fully prefabricated light steel keel intelligent composite wall system consists of the following components: (1) Prefabrication of UHPC decorative thin plate: Prefabricate UHPC decorative thin plate with a width of 3000mm, a height of 4200mm and a thickness of 15mm, and embed 8 three-dimensional deformable stainless steel flexible connectors on the inner side, allowing in-plane displacement of ±1.5mm.

[0029] (2) Preparation of modified light steel keel frame: 0.8mm thick aluminum zinc plate, on the web of C-shaped keel, 10 trapezoidal teeth with a depth of 1.2mm are stamped within 150mm of the end, and 5 trapezoidal teeth with a depth of 0.8mm are in the middle area. One FBG sensor is pre-embedded in the center of each of the upper and lower side beams. SMA component is omitted.

[0030] (3) Preparation of lightweight concrete phase change matrix: Table 2 Component content of lightweight concrete phase change matrix in Example 2 Serial Number Components Content / serving 1 Ordinary Portland cement 110 2 fly ash 30 3 Granulated blast furnace slag powder 5 4 Highly active rice husk ash 30 5 Expanded vitrified microspheres 70 6 Microencapsulated phase change materials 0 7 Nano aerogel particles 3 8 Modified waste PET fiber 1.5 9 Polycarboxylate superplasticizer 1.8 10 tartaric acid 0.25 11 water 39 The lightweight concrete phase change matrix of this embodiment 2 is prepared by the following steps: ① Raw material pretreatment: Mix ordinary silicate cement, fly ash, granulated blast furnace slag powder, and highly active rice husk ash in a dry state for 6 minutes to form a uniform composite cementitious powder A; premix nano aerogel particles with a small amount of expanded vitrified microspheres for 2 minutes to form lightweight functional aggregate B; mix water, water-reducing agent, and tartaric acid evenly in a mixing pot, add all of the composite cementitious powder A, and stir to form a uniform slurry C.

[0031] ② Refined compounding of functional materials and aggregates: Modified waste PET fibers are added sequentially to activated slurry C (dispersed and stirred for 1 min), followed by microencapsulated phase change material (gently stirred for 2 min until uniformly dispersed). Then, the remaining expanded vitrified microspheres and premixed lightweight functional aggregate B are added in two batches, using a "spreading-cutting" stirring method until the aggregate is completely coated by the slurry and evenly distributed. The total stirring time should be strictly controlled within 10 min to prevent the lightweight aggregate from floating or breaking.

[0032] ③ Pouring: The prepared lightweight concrete phase change matrix slurry is injected into a sealed mold with a built-in modified light steel keel frame using a high-pressure injection device. The injection pressure is 0.5 MPa and the injection speed is 1.0 L / s to ensure that the slurry can fully fill the gradient toothed structure and expel air. After pouring, the mold is subjected to low-frequency micro-vibration (frequency 35 Hz, time 40 s) to assist in final compaction.

[0033] ④ Curing: Move the mold to the curing kiln and steam it for 14 hours at 65℃ and ≥95% humidity. After demolding, seal and cure it for 7 days at a constant temperature of (20±5)℃.

[0034] (4) Wall connection and post-treatment: Secure the connectors on the inside of the UHPC sheet to the light steel keel with nuts and adjust them to the designed position. Integrate the system wiring and seal the surface joints.

[0035] Example 3 A fully prefabricated light steel keel intelligent composite wall system consists of the following components: (1) Prefabrication of UHPC decorative thin plate: Prefabricate UHPC decorative thin plate with a width of 3000mm, a height of 4200mm and a thickness of 20mm, and embed 8 three-dimensional deformable stainless steel flexible connectors on the inner side, allowing in-plane displacement of ±1.5mm.

[0036] (2) Preparation of modified light steel keel frame: 1.2mm thick aluminum zinc plate, 12 trapezoidal teeth with a depth of 1.5mm are stamped on the web of C-shaped keel within 200mm of the end, and 6 trapezoidal teeth with a depth of 1.0mm are stamped in the middle area, and the smart nodes with pre-embedded SMA limit pins and FBG sensors are fixed around the frame.

[0037] (3) Preparation of lightweight concrete phase change matrix: Table 3 Component content of lightweight concrete phase change matrix in Example 3 Serial Number Components Content / serving 1 Ordinary Portland cement 95 2 fly ash 30 3 Granulated blast furnace slag powder 5 4 Highly active rice husk ash 20 5 Expanded vitrified microspheres 55 6 Microencapsulated phase change materials (phase change temperature 22℃) 15 7 Nano aerogel particles 3 8 Modified waste PET fiber 2.5 9 Polycarboxylate superplasticizer 2.0 10 tartaric acid 0.16 11 water 30 The lightweight concrete phase change matrix of Example 3 was prepared by the following steps: ① Raw material pretreatment: Mix ordinary silicate cement, fly ash, granulated blast furnace slag powder, and highly active rice husk ash in a dry state for 5 minutes to form a uniform composite cementitious powder A; premix nano aerogel particles with a small amount of expanded vitrified microspheres for 1.5 minutes to form lightweight functional aggregate B; mix water, water-reducing agent, and tartaric acid evenly in a mixing pot, and add all of the composite cementitious powder A, stirring to form a uniform slurry C.

[0038] ② Refined compounding of functional materials and aggregates: Modified waste PET fibers are added sequentially to activated slurry C (dispersed and stirred for 1 min), followed by microencapsulated phase change material (gently stirred for 2 min until uniformly dispersed). Then, the remaining expanded vitrified microspheres and premixed lightweight functional aggregate B are added in two batches, using a "spreading-cutting" stirring method until the aggregate is completely coated by the slurry and evenly distributed. The total stirring time should be strictly controlled within 10 min to prevent the lightweight aggregate from floating or breaking.

[0039] ③ Pouring: A "step-by-step gradient pouring" process is adopted. High-pressure injection equipment is used to inject the material. First, the outdoor concrete layer with a high aerogel content (7 parts nano-aerogel, no microencapsulated phase change material, otherwise consistent with the lightweight concrete phase change matrix formula) is poured. Then, the keel frame is installed, followed by the pouring of the indoor layer (lightweight concrete phase change matrix) containing phase change material. The injection pressure for the outer layer is 0.6 MPa, and for the inner layer, it is 0.8 MPa, with an injection speed of 1.0 L / s, ensuring that the slurry fully fills the gradient toothed structure and expels air. After pouring, the mold is subjected to low-frequency micro-vibration (45 Hz, 50 s) to assist in final compaction.

[0040] ④ Curing: Move the mold to the curing kiln and steam it for 16 hours at 65℃ and ≥95% humidity. After demolding, seal and cure it for 7 days at a constant temperature of (20±5)℃.

[0041] (4) Wall connection and post-treatment: Secure the connectors on the inside of the UHPC sheet to the light steel keel with nuts and adjust them to the designed position. Integrate the system wiring and seal the surface joints.

[0042] Comparative Example 1 The specific preparation method is basically the same as in Example 1, except that the expanded vitrified microspheres in the lightweight concrete phase change matrix component raw materials are replaced with polystyrene particles, and the microencapsulated phase change material is removed.

[0043] Comparative Example 2 The specific preparation method is basically the same as in Example 1, except that no nano-aerogel particles are added to the lightweight concrete phase change matrix component.

[0044] Performance testing According to standards such as GB / T 13475-2008, GB / T 9978.1-2008, GB / T 19889.3-2005, JC / T 2111-2012, GB / T 50081-2019, and GB / T 23451-2023, performance tests were conducted on Examples 1-3 and Comparative Examples 1-2, and the results are shown in Table 4 below.

[0045] Table 4 Performance Table of Fully Prefabricated Light Steel Keel Intelligent Composite Wall Example Compressive strength / MPa <![CDATA[Dry density / (kg / m 3 )]]> <![CDATA[Heat transfer coefficient (K value) / [W / (m 2 ·K)]]]> Phase change temperature regulation effect (ΔT / ℃) Fire resistance limit / h Fire rating Weighted sound insulation (Rw) / dB Durability (freeze-thaw resistance / weather resistance) Example 1 8.5 840 0.25 8-10 ≥2.0 A2 ≥50 Excellent Example 2 5.4 750 0.35 / ≥1.5 A2 ≥45 good Example 3 7.5 810 0.18 5-8 ≥2.0 A2 ≥48 Excellent Comparative Example 1 4.6 730 0.30 / ≤1.0 B1 ≥44 Poor Comparative Example 2 7.8 820 0.40 8-10 ≥2.0 A2 ≥49 good Table 4 shows that the fully prefabricated light steel keel intelligent composite wall prepared in Example 1 has balanced and top-notch performance in all aspects, integrating high strength, ultra-low heat transfer, active temperature regulation, and excellent fire resistance, making it suitable for most climate zones. Example 2 significantly reduces costs by omitting phase change materials while ensuring Class A fire resistance and good thermal insulation, demonstrating market flexibility. Example 3, through a "gradient composite" design, achieves the lowest K value (≤0.18) and excellent anti-condensation ability by asymmetrically and functionally distributing phase change materials and aerogel along the wall thickness direction, specifically designed for harsh climates.

[0046] Comparative Example 1 replaced expanded vitrified microspheres with polystyrene particles while removing the microencapsulated phase change material. This is because the introduction of polystyrene particles poses risks of flammability and low strength, and the addition of temperature- and dispersion-sensitive microencapsulated phase change material would further exacerbate the system's instability, inhomogeneity, and safety hazards. Although polystyrene particles are lightweight and have a acceptable K-value, their drastic drop in fire resistance (B1 rating) and poor durability are fatal flaws. This comparison strongly demonstrates that replacing inorganic vitrified microspheres with inexpensive organic materials fundamentally undermines the safety baseline and long-term reliability necessary for walls as building envelopes, thus highlighting the innovative level of the original patented formula in the synergy of "safety-performance-green" integration.

[0047] Comparative Example 2, without the addition of nano-aerogel particles, showed that under the exact same formulation, simply removing the nano-aerogel resulted in a decrease in the heat transfer coefficient K value from 0.25 to 0.40, with a reduction in thermal insulation performance of over 37%. This comparison clearly quantifies the core role of nano-aerogel particles in achieving an "ultra-low heat transfer coefficient," making them a key technical component for achieving high-performance thermal insulation goals for walls.

[0048] The technical effects claimed by this invention can be achieved by using the preparation process and the parameter range defined in this invention, and therefore no further examples will be provided to support these claims.

Claims

1. A fully prefabricated light steel keel intelligent composite wall system, characterized in that, include: As shown in Figure 1, the UHPC decorative thin panel (1) is located on the outermost side of the wall and has a pre-fabricated drip groove (1.1) at the bottom. The lightweight concrete phase change matrix (3) is filled and solidified in the cavity of the modified light steel keel frame (2). The intelligent sensing node (4) is integrated at the four-sided connection of the modified light steel keel frame (2). The steel mesh (5) is composited on the inner and outer sides of the modified light steel keel frame (2). The innermost side of the wall is provided with a leveling plaster layer (6).

2. The fully prefabricated light steel keel intelligent composite wall system according to claim 1, characterized in that, The lightweight concrete phase change matrix comprises the following raw materials by weight: 95-120 parts ordinary silicate cement, 20-40 parts fly ash, 5-15 parts granulated blast furnace slag powder, 20-35 parts highly active rice husk ash, 40-70 parts expanded vitrified microspheres, 8-20 parts microencapsulated phase change material, 3-10 parts nano aerogel particles, 1-4 parts modified waste PET fiber, 1.0-3.5 parts polycarboxylate-based high-efficiency water-reducing agent, 0.1-0.5 parts tartaric acid, and 30-55 parts water.

3. The fully prefabricated light steel keel intelligent composite wall system according to claim 1, characterized in that, The modified light steel keel skeleton has an asymmetrical gradient tooth structure on its web and wing plates, as shown in Figure 2. The asymmetrical trapezoidal teeth (7) are stamped on the light steel keel web (8) and light steel keel wing plates (9), and the size and density of the directional teeth change in a gradient.

4. The fully prefabricated light steel keel intelligent composite wall system according to claim 1, characterized in that, The UHPC decorative sheet is mechanically connected to the internal modified light steel keel frame through a pre-embedded three-dimensional deformable flexible connector, as shown in Figure 3. The three-dimensional deformable flexible connector has a groove design (11) in the X / Y direction to absorb the in-plane deformation caused by thermal expansion and contraction between the UHPC decorative sheet (1) and the internal structure; the Z direction is the rotation direction of the ball joint design and has an elastic pad (10). The ball joint design allows the connector to undergo small angular deflection in multiple directions to adapt to the uneven deformation of the structure; the elastic pad provides vertical elastic support, allows small warping deformation, absorbs vibration, and ensures that the connection point does not form a rigid hard point.

5. The fully prefabricated light steel keel intelligent composite wall system according to claim 1, characterized in that, The intelligent sensing nodes are shape memory alloy (SMA) limiting pins and fiber optic grating (FBG) sensors. As shown in Figure 4, the FBG sensor (12) and the SMA limiting pin (13) are both set at the key stress-bearing parts of the modified light steel keel frame. The SMA limiting pins are pre-embedded at the four corner ends of the modified light steel keel. The FBG sensor is pasted on the middle of the four vertical keels and the upper and lower keels near the SMA limiting pins.

6. The fully prefabricated light steel keel intelligent composite wall system according to claim 2, characterized in that, The microencapsulated phase change material has a core material of disodium hydrogen phosphate dodecahydrate (Na2HPO4·12H2O), an inorganic hydrated salt phase change material. Through microencapsulation technology, the core material is encapsulated within an inorganic-organic composite wall material, forming micron / nano-scale composite particles. The phase change temperature is stable at 23℃-26℃, and the latent heat of phase change is not less than 180 J / g.

7. The fully prefabricated light steel keel intelligent composite wall system according to claim 2, characterized in that, The nano-aerogel particles are hydrophobic nano-silica aerogel particles with a thermal conductivity of 0.020 W / (m·K).

8. The fully prefabricated light steel keel intelligent composite wall system according to claim 2, characterized in that, The preparation of the lightweight concrete phase change matrix includes the following steps: (1) Raw material pretreatment: ordinary silicate cement, fly ash, granulated blast furnace slag powder and high-activity rice husk ash are mixed in a dry state for 5-8 minutes to form a uniform composite cementitious powder A; nano aerogel particles and a small amount of expanded vitrified microspheres are premixed for 1-2 minutes to form lightweight functional aggregate B; water, water-reducing agent and tartaric acid are mixed evenly in a mixing pot, and all the composite cementitious powder A is added and stirred to form a uniform slurry C; (2) Refined compounding of functional materials and aggregates: Modified waste PET fibers (dispersed and stirred for 1-2 min) and microencapsulated phase change materials (gently stirred for 2-4 min until uniformly dispersed) are added sequentially to activated slurry C. Then, the remaining expanded vitrified microspheres and premixed lightweight functional aggregate B are added in two batches, using a "spreading-cutting" stirring method until the aggregate is completely coated by the slurry and evenly distributed. The total stirring time should be strictly controlled within 10-15 min to prevent the lightweight aggregate from floating or breaking. (3) Casting: The prepared lightweight concrete phase change matrix slurry is injected into a sealed mold with a built-in modified light steel keel frame through a high-pressure injection device. The injection pressure is 0.4-1.0 MPa and the injection speed is 0.5-2.0 L / s to ensure that the slurry can fully fill the gradient toothed structure and expel air. After casting, the mold is subjected to low-frequency micro-vibration (frequency 30-50 Hz, time 30-60 s) to assist in final compaction. (4) Curing: Move the mold to the curing kiln and steam it for 12-16 hours at (60±5)℃ and ≥95% humidity. Then switch to constant temperature sealed curing at (20±5)℃ for more than 7 days.

9. The fully prefabricated light steel keel intelligent composite wall system according to claim 5, characterized in that, The shape memory alloy (SMA) limiting pin is made of nickel-titanium alloy, and its austenitic phase transformation end temperature (Af) is set to (20±5)℃. It has superelastic properties and can recover strain of not less than 6%. It is used to dissipate energy through superelastic hysteresis under earthquake or wind load and to assist the wall in resetting after the load is unloaded.

10. The fully prefabricated light steel keel intelligent composite wall system according to claim 5, characterized in that, The fiber optic grating (FBG) sensor has a strain measurement accuracy of no less than ±1με and a temperature measurement accuracy of no less than ±0.5℃. It is encapsulated with an alkali-resistant polyimide coating and is used to monitor the strain distribution and internal temperature field of the wall in real time.

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