Self-fire-resistant ECC fabricated superimposed shear wall structure and construction method

Abstract

The invention discloses a self-fire-resistant ECC fabricated composite shear wall structure and a construction method, and belongs to the technical field of fabricated constructions.The self-fire-resistant ECC fabricated composite shear wall structure comprises two opposite leaf plates, a cast-in-place cavity is reserved between the leaf plates, a plurality of rows of outwards-protruding stirrups are evenly pre-embedded in the opposite faces of the leaf plates, and a plurality of positioning rib plates are pre-embedded in the top of each row of outwards-protruding stirrups; a plurality of positioning rib holes are uniformly formed in the positioning rib plate; after the two blade plates are installed, U-shaped steel bars are inserted into the opposite positioning rib plates; the blade plate comprises a self-fire-resistant ECC prefabricated plate body; the self-fire-resistant ECC is prepared from the following raw materials in parts by weight: 1 part of cement; 0.545 part of metakaolin; 0.273 part of lime powder; 1.455 parts of fly ash; 1.117 parts of sand; 0.193 part of nano silicon dioxide; 0.385 part of high-performance hollow glass beads; 1.040 parts of water; 0.033 part of a water reducing agent; the fiber volume accounts for 2% of the preparation volume. The technical problems that in the prior art, an assembly type shear wall adopts common concrete, inner and outer leaf plates are thick, and a fireproof layer needs to be additionally constructed are solved.

Description

Technical Field

[0001] This invention belongs to the field of prefabricated building technology, specifically relating to a prefabricated composite shear wall structure with self-fire-resistant ECC and its construction method. Background Technology

[0002] The statements in this section are merely background information related to the present invention and do not necessarily constitute prior art.

[0003] Traditional cast-in-place shear walls have disadvantages such as low construction efficiency and large labor requirements. Therefore, existing technologies mostly use precast shear walls. However, precast shear walls have disadvantages such as heavy weight and the use of sleeve grouting connection, which make transportation and installation difficult and result in poor overall integrity.

[0004] The prior art discloses a double-panel split composite shear wall, including two precast wall panels. Bolt holes are provided at the four corners of each precast wall panel for setting adjustment bolts. There is a connecting component between the precast wall panels. The connecting component includes a wire mesh with multiple rows of rings. Fixed reinforcing bars are connected to the rings. Hooks are connected to the fixed reinforcing bars. When the precast wall panels are connected, the fixed reinforcing bars are rotated so that the hooks hook onto the truss of the wall panels. Finally, concrete is poured between the precast wall panels.

[0005] The above-mentioned solution has the advantages of being lighter and having better overall integrity compared to a monolithic precast shear wall, but it still has the following problems: When assembling precast wall panels, the connecting components must first be placed between two wall panels. The connecting components are easily damaged when aligning the precast wall panels. In addition, the precast shear wall uses ordinary concrete, which has poor crack resistance, resulting in thicker inner and outer leaf panels. Furthermore, it is prone to cracking and peeling under long-term service loads or seismic loads, which weakens its strength and durability. Therefore, an additional fireproof layer needs to be applied to both sides of the wall for fire protection. Summary of the Invention

[0006] In view of this, the purpose of the present invention is to provide a prefabricated composite shear wall structure and construction method with self-fire-resistant ECC, so as to solve the technical problems in the prior art where the connecting components of the prefabricated shear wall are easily damaged when aligning the prefabricated wall panels, and the use of ordinary concrete has poor crack resistance, resulting in thicker inner and outer leaf panels and the need to apply an additional fireproof layer.

[0007] To achieve the above objectives, the present invention adopts the following technical solution: In the first aspect, a prefabricated composite shear wall structure with self-fire-resistant ECC is provided, including two opposing blades, with a pre-reserved cast-in-place cavity between the blades for cast-in-place concrete; Multiple rows of outwardly protruding stirrups are evenly embedded on the opposite surfaces of the two blades. Multiple positioning ribs are embedded at the top of each row of outwardly protruding stirrups. Multiple positioning rib holes are evenly opened on the positioning ribs along the length of the blade. After the two leaf plates are installed, U-shaped steel bars are inserted into the positioning rib holes of the relative positioning rib plates; The blade includes a plate body, which is precast and cast using self-fire-resistant ECC. The raw material composition and weight parts of the self-fire-resistant ECC are as follows: 1 part cement; 0.545 parts metakaolin; 0.273 parts lime powder; 1.455 parts fly ash; 1.117 parts sand; 0.193 parts nano silica; 0.385 parts high-performance hollow glass microspheres; 1.040 parts water; 0.033 parts water-reducing agent; the self-fire-resistant ECC also contains fibers, and the fiber volume accounts for 2% of the volume of the self-fire-resistant ECC preparation.

[0008] Preferably, the self-fire-resistant ECC has an apparent density of 1500 kg / m³, a thermal conductivity of 0.6 W / (m·K), a tensile strength of 5 MPa, a tensile strain of 8%, and a compressive strength of 37.5 MPa.

[0009] Preferably, when the two blades are arranged opposite each other, the protruding stirrups are staggered vertically; and the length of the protruding stirrups protruding from the blade is shorter than the thickness of the cast-in-place cavity.

[0010] Preferably, the leaf plate contains a steel mesh, and the protruding stirrups are tied together with the steel mesh at the designed spacing.

[0011] Preferably, the positioning rib plate is a T-shaped plate, including a flat plate and a vertical plate connected to the center line of the flat plate. The positioning rib holes are opened on the vertical plate, and the flat plate is welded to the steel mesh of the leaf plate.

[0012] Preferably, mounting holes are provided at the four corners of the blade for mounting positioning and limiting components.

[0013] Preferably, the positioning and limiting component includes a positioning element and a positioning screw. The positioning element includes a long plate that connects two fixed clamping plates. The distance between the fixed clamping plates is equal to the thickness of the cast-in-place cavity minus the sum of the thicknesses of the two fixed clamping plates. The positioning element also includes two movable clamping plates. The fixed clamping plates and the movable clamping plates are the same size, and each has a screw hole in its center.

[0014] Preferably, the long plate is attached to the sides of the two blades and aligned. The position of the positioning component is adjusted so that the screw hole is aligned with the mounting hole. The positioning screw passes through the screw hole and the mounting hole, and the moving clamp is installed on the positioning screw on the outside of the blade.

[0015] Secondly, a construction method for the aforementioned prefabricated composite shear wall structure with self-fire-resistant ECC is provided, the specific steps of which include: Precast blades: The mold for assembling blades is used to tie steel mesh, and external convex stirrups and positioning ribs are connected to the steel mesh. At the same time, lifting points are also embedded; the positions of each embedded part are calibrated, and then self-fire-resistant ECC is prepared and cast. After pouring, the surface is finished and cured, and it is safely removed after its strength meets the requirements; prefabricate U-shaped steel bars that match the specifications of the leaf plates generated by the current mold; On-site assembly of blades: Assemble two opposing blades, keeping the outwardly protruding stirrups staggered vertically; then install the positioning and limiting components, followed by the U-shaped steel bars; seal the formwork at both ends of the cast-in-place cavity; finally, pour concrete into the cast-in-place cavity.

[0016] Preferably, the preparation process of the self-fire-resistant ECC is as follows: Determine the total volume and total mass based on the required number of blades to be manufactured; weigh the raw materials of each component of the self-fire-resistant ECC and prepare sufficient raw materials; First, put cement, metakaolin, lime powder, fly ash, nano silica, high-performance hollow glass microspheres, and water-reducing agent into the mixing drum and dry mix them to obtain a uniformly mixed dry material. Then add water and water-reducing agent and stir until the cement becomes a fluid plastic state; Adding polyethylene fiber and stirring until uniform yields self-fire-resistant ECC.

[0017] Compared with the prior art, the advantages and positive effects of this invention are: This invention pre-embeds multiple positioning ribs on one side of two blades facing each other. After the two blades are installed facing each other, the two ends of the U-shaped steel bars are inserted into the positioning ribs of the two blades. During the assembly and construction stage, there is no interference from longitudinal steel bars between the blades, making installation more convenient. The U-shaped steel bars are inserted after the blades are installed, avoiding damage to the U-shaped steel bars during blade installation and improving connection quality. The blade body of this invention is a self-fire-resistant ECC precast panel, which has good crack resistance and high temperature resistance. At high temperatures, the damage of self-fire-resistant ECC is less than that of ordinary ECC, and it has excellent self-fire-resistant performance. It can reduce the thickness of the blades, increase the thickness of the cast-in-place cavity, reduce the difficulty of pouring cast-in-place concrete in the cast-in-place cavity, improve the pouring quality and efficiency, and eliminate the need for a separate fireproof layer later, saving construction time and costs. Attached Figure Description

[0018] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an improper limitation of the invention.

[0019] Figure 1 This is a schematic diagram of the prefabricated composite shear wall structure of Embodiment 1 or 2 of the present invention; Figure 2 This is a schematic diagram of the positioning stiffener plate in Embodiment 1 or 2 of the present invention; Figure 3 This is a schematic diagram of the positioning restriction component in Embodiment 1 or 2 of the present invention; In the picture: 1. Leaf plate; 11. Mounting hole; 2. Outwardly protruding stirrup; 3. U-shaped steel bar; 4. Cast-in-place cavity; 5. Positioning rib plate; 51. Positioning rib hole; 6. Positioning restraint component; 61. Positioning component; 611. Long plate; 612. Fixed clamping plate; 613. Moving clamping plate; 62. Positioning screw. Detailed Implementation

[0020] It should be noted that the following detailed description is illustrative and intended to provide further explanation of the invention. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0021] The present invention will now be described in detail with reference to the accompanying drawings.

[0022] Example 1 This embodiment discloses a prefabricated composite shear wall structure with self-fire-resistant ECC, such as... Figure 1 As shown, the structure includes two opposing blades 1, with a pre-reserved cast-in-place cavity 4 between the blades 1 for casting concrete. The cast-in-place concrete and the two blades 1 together form a shear wall. Within the cast-in-place cavity 4, the two opposing blades 1 are connected to the cast-in-place concrete by protruding stirrups 2 and U-shaped steel bars 3, thus connecting the two opposing blades 1 into a single unit. In this embodiment, the blades 1 are prefabricated components, with molds corresponding to the blades 1 prefabricated in a prefabrication plant.

[0023] like Figure 1 As shown, the outwardly protruding stirrups 2 are embedded in the blade plate 1. Specifically, multiple rows of outwardly protruding stirrups 2 are embedded on one side of the two blade plates 1 facing each other. The multiple rows of outwardly protruding stirrups 2 are evenly distributed along the length direction of the blade plate 1. Each row of outwardly protruding stirrups 2 includes multiple outwardly protruding stirrups 2, and the multiple outwardly protruding stirrups 2 are evenly distributed along the height direction of the blade plate 1.

[0024] like Figure 1 As shown, horizontal positioning ribs 5 are also pre-embedded on the opposite side of the two blades 1. Specifically, on the opposite side of the two blades 1, multiple positioning ribs 5 are pre-embedded on the top of each row of outwardly protruding stirrups 2. Along the length of the blade 1, multiple positioning rib holes 51 are evenly opened on the positioning ribs 5. The positioning ribs 5 are used to install and fix the U-shaped steel bars 3. Figure 1 As shown, after the two leaf plates 1 are installed opposite each other, the two ends of the U-shaped steel bar 3 are inserted into the positioning rib holes 51 of the positioning rib plates 5 of the two leaf plates 1. The purpose of setting multiple positioning rib plates 5 is to prevent the two ends of the U-shaped steel bar 3 from tilting and to keep it as vertical as possible when inserted into the cast-in-place cavity 4.

[0025] In this embodiment, horizontal outward-protruding stirrups 2 and vertical U-shaped steel bars 3 are installed inside the cast-in-place cavity 4 to ensure the overall connection and stability of the wall after concrete is poured inside the cast-in-place cavity 4. The purpose of setting the positioning rib plate 5 is to position the U-shaped steel bars 3 and limit their deflection or displacement.

[0026] It is understandable that simply pouring cast-in-place concrete between the two leaf plates 1, relying solely on the adhesive strength of the panels, cannot guarantee the stability of the connection between the two leaf plates 1 and the cast-in-place concrete. By inserting the U-shaped reinforcing bars 3 into the positioning reinforcement plates 5 only after the two leaf plates 1 are installed relative to each other, the technical problem of easily damaging the connecting components when pre-placing the connecting components between the two precast wall panels during assembly in existing technologies is solved. The connection method in this embodiment ensures connection quality, and during the assembly and construction phase, there is no interference from longitudinal reinforcing bars between the leaf plates, making installation more convenient.

[0027] In this embodiment, each blade 1 includes a plate body, which is precast using self-fire-resistant ECC (ECC stands for Engineered Cementitious Composites). Traditional engineered cementitious composites are ultra-high ductility fiber-reinforced cementitious composites formed by adding a certain amount of short fibers to a matrix composed of water, silicate cement, quartz sand, fly ash, and high-performance water-reducing agents. Their ultimate tensile strain can reach 3% to 6%, which is 300 to 600 times that of ordinary concrete, exhibiting extremely high toughness, tensile strength, crack resistance, and high energy consumption characteristics.

[0028] In addition to its superior crack resistance and high energy consumption characteristics, the self-fire-resistant ECC of this embodiment also possesses self-fire resistance. Because the performance of the self-fire-resistant ECC is superior to that of traditional concrete, the thickness of the blade 1 can be reduced, and the reinforcement of the blade 1 can also be reduced, thereby increasing the thickness of the cast-in-place cavity 4. This reduces the difficulty of pouring the cast-in-place concrete within the cavity 4, improving pouring quality and efficiency. Furthermore, it eliminates the need for a separate fireproof layer application later, saving time and costs.

[0029] In this embodiment, the raw material composition and weight parts of the self-fire-resistant ECC used are as follows: 1 part cement; 0.545 parts metakaolin; 0.273 parts lime powder; 1.455 parts fly ash; 1.117 parts sand; 0.193 parts nano silica; 0.385 parts high-performance hollow glass microspheres; 1.040 parts water; 0.033 parts water-reducing agent; the self-fire-resistant ECC also contains fibers, which are added at 2% of the total volume of the self-fire-resistant ECC preparation.

[0030] In this embodiment, high-performance hollow glass microspheres (HGM, a hollow spherical powdered ultralight inorganic non-metallic material) were added to the fire-resistant ECC. Due to its unique hollow structure, HGM has low density and good thermal insulation properties. Under high-temperature conditions, HGM undergoes a chemical reaction, and its products effectively enhance the interfacial bonding with cement paste. Furthermore, the hollow structure of HGM effectively alleviates the vapor pressure inside the material, thereby improving its fire resistance.

[0031] In this embodiment, fly ash and metakaolin are added to the self-fire-resistant ECC. Fly ash and metakaolin, acting as auxiliary cementing materials, can generate a large number of high-temperature resistant phases under high-temperature conditions, thereby significantly improving the fire resistance of the self-fire-resistant ECC and increasing its residual strength after high temperatures. The blade 1 prepared from the self-fire-resistant ECC has higher strength, allowing for a reduction in the thickness of the blade 1 and an increase in the thickness of the cast-in-place cavity 4.

[0032] In this embodiment, nano-silica (NS) is also added to the self-fire-resistant ECC. On the one hand, it can achieve a good filling effect, which significantly reduces the porosity and microcracks of the self-fire-resistant ECC and increases its density. On the other hand, the addition of a set amount of nano-silica can also improve the strength of the self-fire-resistant ECC and make up for the strength loss caused by the addition of high-performance hollow glass microspheres.

[0033] Lime powder is a cementitious material with a lower cost than cement. In self-fire-resistant ECC, it can replace part of the cement, reducing material costs while maintaining excellent performance. Cement production is one of the main sources of carbon dioxide emissions, and adding some lime powder can reduce carbon emissions. In addition, lime powder can be used as a microfiller to fill the gaps between cement particles, making the microstructure of the matrix more compact and uniform, which helps to improve the initial strength and toughness of the matrix.

[0034] In this embodiment, the self-fire-resistant ECC prepared according to the above-mentioned proportions has the following characteristics: apparent density of 1500 kg / m³, thermal conductivity of 0.6 W / (m·K), tensile strength of 5 MPa, tensile strain of 8%, exhibiting significant tensile strain hardening and multi-crack characteristics, and compressive strength of 37.5 MPa. Simultaneously, the incorporation of high-performance hollow glass microspheres and nano-silica not only significantly reduces the apparent density and thermal conductivity of the ECC, but also provides good tensile strain and relatively high strength.

[0035] In this embodiment, compared with ordinary ECC with the same water-cement ratio, the tensile strength of the self-fire-resistant ECC is slightly lower, while the compressive strength of the self-fire-resistant ECC is increased by 19.37%. After being subjected to a high temperature of 200°C, unlike ordinary ECC which experiences a decrease in strength, the compressive strength of the self-fire-resistant ECC is increased by 8% compared with the strength at room temperature. When the temperature exceeds 200°C, the compressive strength decreases with the increase of the constant temperature time. At 800°C, the residual strength of the self-fire-resistant ECC is 52% of the strength at room temperature, while the residual strength of ordinary ECC is only 26% of the strength at room temperature. It can be seen that the self-fire-resistant ECC suffers relatively less damage at high temperatures and has excellent self-fire-resistant properties.

[0036] In this embodiment, the fiber is polyethylene fiber.

[0037] In this embodiment, the length of the U-shaped steel bar 3 is equal to the distance between the top positioning rib plate 5 of the leaf plate 1 and the bottommost outwardly protruding stirrup 2 of the leaf plate 1; two positioning rib plates 5 are set in the same column, with a spacing of 15 to 30 centimeters. This distance is set because the thickness of the cast-in-place cavity 4 is limited, and it is not easy to insert the U-shaped steel bar 3 into the lower positioning rib plate 5 when the spacing of the positioning rib plates 5 is too long.

[0038] It should be noted that in this embodiment, the elevations of the protruding stirrups 2 on the two oppositely arranged blades 1 are inconsistent. The elevation of the protruding stirrup 2 on one blade 1 is set at a certain distance higher or lower than the elevation of the protruding stirrup 2 on the other blade 1. In this embodiment, this set distance is three centimeters, allowing the protruding stirrups 2 on the two blades 1 to be staggered vertically. When the two blades 1 are installed opposite each other, the protruding stirrups 2 on the two blades 1 can overlap vertically. In this embodiment, after the two blades 1 are installed opposite each other, the protruding stirrups 2 on the sides and top, which are easy to tie, can be fixed using steel wire.

[0039] like Figure 1 As shown, the thickness of the cast-in-place cavity 4 is equal to the design required wall thickness minus the thickness of the two leaf plates 1. The length of the protruding stirrup 2 protruding from the leaf plate 1 is shorter than the thickness of the cast-in-place cavity 4 by a predetermined distance (in this embodiment, this distance is set to three centimeters), so that the cast-in-place concrete can completely enclose the protruding stirrup 2. In addition, since the length of the protruding stirrup 2 protruding from the leaf plate 1 is shorter than the predetermined distance, after the relative arrangement of the two leaf plates 1 is completed, the two ends of the U-shaped steel bar 3 can pass through the outside of the protruding stirrup 2 of the two leaf plates 1 respectively.

[0040] In this embodiment, the blade plate 1 contains a steel mesh, and the outwardly protruding stirrups 2 are tied together with the steel mesh of the blade plate 1 according to the design spacing. After the self-fire-resistant ECC is poured, they are connected to the blade plate 1 as a whole.

[0041] In this embodiment, the positioning rib plate 5 is a T-shaped plate, including a flat plate and a vertical plate connected vertically to the center line of the flat plate. The positioning rib hole 51 is opened on the vertical plate. The flat plate is welded to the steel mesh of the leaf plate 1 and is connected to the leaf plate 1 as a whole after the self-fire-resistant ECC is poured.

[0042] like Figure 2 As shown, mounting holes 11 are made at the four corners of the blade 1. The mounting holes 11 are used to install positioning restraint components 6 of corresponding specifications (i.e., shear walls of different thicknesses have different positioning restraint components). When concrete is poured into the cast-in-place cavity 4, the pressure inside the cast-in-place cavity 4 increases, causing the blades 1 to move away from each other. Installing positioning restraint components 6 at the four corners of two opposing blades 1 can prevent the pressure inside the cast-in-place cavity 4 from increasing and causing the blades 1 to move away from each other.

[0043] like Figure 3 As shown, the positioning limiting component 6 includes a positioning element 61 and a positioning screw 62. The positioning element 61 includes a long plate 611, which is fixedly connected to two fixed clamping plates 612. The distance between the fixed clamping plates 612 is equal to the thickness of the cast-in-place cavity 4 minus the sum of the thicknesses of the two fixed clamping plates 612. The positioning element 61 also includes two movable clamping plates 613. The fixed clamping plates 612 and the movable clamping plates 613 are the same size, and each has a screw hole in its center. When installing two opposing blades 1, the long plate 611 of the positioning element 61 is attached to the side of the two blades 1 and aligned. Then, the position of the positioning element 61 is adjusted so that the screw hole is aligned with the mounting hole 11. Then, the positioning screw 62 passes through the screw hole and the mounting hole 11. On the outside of the blade 1, the movable clamping plate 613 is installed on the positioning screw 62. A nut is threaded onto the outside of the movable clamping plate 613 to complete the installation of the positioning limiting component 6. It should be noted that the fixed clamping plate 612 can prevent the blade 1 from shifting inward, and the movable clamping plate 613 cooperates with the positioning screw 62 and nut to restrict the blade 1 from shifting outward.

[0044] It should be noted that a plastic tube is first inserted into the screw hole and the mounting hole 11, and then the positioning screw 62 is passed through the plastic tube so that the positioning screw 62 can be removed after the in-situ pouring; finally, grout is injected into the plastic tube to seal it.

[0045] In this embodiment, the positioning member 61 at the bottom of the blade plate 1 is different from the positioning member 61 at the top in that the long plate 611 of the bottom positioning member 61 is a regular long plate, while the long plate 611 of the top positioning member 61 is an L-shaped long plate with two regular long plates connected vertically, including regular long plates attached to the side and top of the blade plate 1.

[0046] Example 2 This embodiment discloses a construction method for a prefabricated composite shear wall structure with self-fire-resistant ECC, the specific steps of which include: Precast blades: Ensure the mold of blade 1 is clean and complete its precise assembly, then apply a layer of water-based release agent evenly to the surface to improve the demolding effect; tie the steel mesh of blade 1, and connect the protruding stirrups and positioning ribs to the steel mesh, while also embedding the lifting points; After confirming that the position calibration is correct, prepare the self-fire-resistant ECC and pour it into the mold; After pouring, the surface is finished and cured. Once the strength meets the requirements, it can be safely removed. Prefabricate U-shaped steel bars that match the specifications of leaf plate 1 generated by the current mold; On-site assembly of blades: Assemble two opposing blades 1, keeping the protruding stirrups 2 of the two opposing blades 1 staggered vertically; install positioning and limiting components 6, then install U-shaped steel bars; finally, seal the formwork at both ends of the cast-in-place cavity 4. Cast-in-place concrete: Concrete is poured into the cast-in-place cavity 4.

[0047] In this embodiment, the preparation process of the self-fire-resistant ECC specifically includes: Determine the total volume and total mass based on the required number of blades 1 to be manufactured; weigh the raw materials of each component of the self-fire-resistant ECC and prepare sufficient raw materials; First, cement, metakaolin, lime powder, fly ash, nano silica, and high-performance hollow glass microspheres are put into a mixing cylinder and dry-mixed to obtain a uniformly mixed dry material. Then add water and water-reducing agent and stir until the cement becomes a fluid plastic state; Adding polyethylene fiber and stirring until uniform yields self-fire-resistant ECC.

[0048] The raw material composition and weight percentages of the self-fire-resistant ECC are as follows: 1 part cement; 0.545 parts metakaolin; 0.273 parts lime powder; 1.455 parts fly ash; 1.117 parts sand; 0.193 parts nano silica; 0.385 parts high-performance hollow glass microspheres; 1.040 parts water; 0.033 parts water-reducing agent; and fiber added at 2% of the total volume of the self-fire-resistant ECC preparation.

[0049] While the specific embodiments of the present invention have been described above in conjunction with the accompanying drawings, this is not intended to limit the scope of protection of the present invention. Those skilled in the art should understand that various modifications or variations that can be made by those skilled in the art without creative effort based on the technical solutions of the present invention are still within the scope of protection of the present invention.

Claims

1. A prefabricated composite shear wall structure with self-fire-resistant ECC, characterized in that, It includes two opposing blades, with a pre-reserved cavity between the blades for casting in place; Multiple rows of outwardly protruding stirrups are evenly embedded on the opposite surfaces of the two blades. Multiple positioning ribs are embedded at the top of each row of outwardly protruding stirrups. Multiple positioning rib holes are evenly opened on the positioning ribs along the length of the blade. After the two leaf plates are installed, U-shaped steel bars are inserted into the positioning rib holes of the relative positioning rib plates; The blade includes a plate body, which is precast and cast using self-fire-resistant ECC. The raw material composition and weight parts of the self-fire-resistant ECC are as follows: 1 part cement; 0.545 parts metakaolin; 0.273 parts lime powder; 1.455 parts fly ash; 1.117 parts sand; 0.193 parts nano silica; 0.385 parts high-performance hollow glass microspheres; 1.040 parts water; 0.033 parts water-reducing agent; the self-fire-resistant ECC also contains fibers, and the fiber volume accounts for 2% of the volume of the self-fire-resistant ECC preparation.

2. The prefabricated composite shear wall structure with self-fire-resistant ECC as described in claim 1, characterized in that, The self-fire-resistant ECC has an apparent density of 1500 kg / m³, a thermal conductivity of 0.6 W / (m·K), a tensile strength of 5 MPa, a tensile strain of 8%, and a compressive strength of 37.5 MPa.

3. The prefabricated composite shear wall structure with self-fire-resistant ECC as described in claim 1, characterized in that, When the two blades are arranged opposite each other, the protruding stirrups are staggered vertically; and the length of the protruding stirrups protruding from the blade is shorter than the thickness of the cast-in-place cavity.

4. The prefabricated composite shear wall structure with self-fire-resistant ECC as described in claim 1, characterized in that, The blade contains a steel mesh, and the outwardly protruding stirrups are tied together with the steel mesh at the designed spacing.

5. A prefabricated composite shear wall structure with self-fire-resistant ECC as described in claim 4, characterized in that, The positioning rib plate is a T-shaped plate, including a flat plate and a vertical plate connected to the center line of the flat plate. Positioning rib holes are opened on the vertical plate, and the steel mesh of the flat plate and the leaf plate are welded together.

6. The prefabricated composite shear wall structure with self-fire-resistant ECC as described in claim 1, characterized in that, Mounting holes are provided at the four corners of the blade for mounting positioning and limiting components.

7. A prefabricated composite shear wall structure with self-fire-resistant ECC as described in claim 6, characterized in that, The positioning and limiting component includes a positioning element and a positioning screw. The positioning element includes a long plate that connects two fixed clamping plates. The distance between the fixed clamping plates is equal to the thickness of the cast-in-place cavity minus the sum of the thicknesses of the two fixed clamping plates. The positioning element also includes two movable clamping plates. The fixed clamping plates and the movable clamping plates are the same size, and each has a screw hole in its center.

8. A prefabricated composite shear wall structure with self-fire-resistant ECC as described in claim 7, characterized in that, The long plate is attached to the sides of the two blades and aligned. The position of the positioning component is adjusted so that the screw hole is aligned with the mounting hole. The positioning screw passes through the screw hole and the mounting hole. The moving clamp is installed on the positioning screw on the outside of the blade.

9. A construction method for a prefabricated composite shear wall structure with self-fire-resistant ECC as described in any one of claims 1-8, characterized in that, The specific steps include: Precast blade: Assemble the mold of the blade and tie the steel mesh therein, connect the outwardly protruding stirrups and the positioning ribs to the steel mesh, and also embed the lifting points; calibrate the position of each embedded part, and then prepare and cast the self-fire-resistant ECC; After pouring, the surface is finished and cured, and it is safely removed after its strength meets the requirements; the U-shaped steel bars are prefabricated to match the specifications of the leaf plates generated by the current mold. On-site assembly of blades: Assemble two opposing blades, keeping the outwardly protruding stirrups staggered vertically; then install the positioning and limiting components, followed by the U-shaped steel bars; seal the formwork at both ends of the cast-in-place cavity, and finally pour concrete into the cast-in-place cavity.

10. The construction method of a prefabricated composite shear wall structure with self-fire-resistant ECC as described in claim 9, characterized in that, The specific preparation process of the self-fire-resistant ECC is as follows: Determine the total volume and total mass based on the required number of blades to be manufactured; weigh the raw materials of each component of the self-fire-resistant ECC and prepare sufficient raw materials; First, cement, metakaolin, lime powder, fly ash, nano silica, and high-performance hollow glass microspheres are put into a mixing drum and dry-mixed to obtain a uniformly mixed dry material; then water and water-reducing agent are added and stirred until the cement becomes a fluid plastic state. Adding polyethylene fiber and stirring until uniform yields self-fire-resistant ECC.

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