UHPC prefabricated superimposed shear wall structure and construction method thereof

Abstract

The invention provides a UHPC prefabricated superimposed shear wall structure and a construction method thereof, and relates to the technical field of constructional engineering.The structure comprises a first prefabricated superimposed shear wall and a second prefabricated superimposed shear wall which are connected in an inserted mode, and post-pouring grooves are formed in the adjacent ends of the first prefabricated superimposed shear wall and the second prefabricated superimposed shear wall correspondingly; the leveling unit comprises two threaded sleeves and a threaded connecting rod; the two threaded sleeves are pre-buried in the two post-pouring grooves correspondingly, the threaded connecting rod is provided with a first connecting section and a second connecting section, the thread turning directions of the first connecting section and the second connecting section are opposite, the first connecting section is in threaded connection with the first connecting rod, and the second connecting section is in threaded connection with the second connecting rod; adjusting sleeves are arranged at the ends, away from each other, of the first connecting rod and the second connecting rod correspondingly. The two adjusting sleeves are connected with the two threaded sleeves through leveling screws and self-locking nuts correspondingly. The post-pouring channel is formed in the side wall of the post-pouring groove and communicates with the inserting connection position of the two prefabricated superimposed shear walls. Therefore, the mechanical property and the construction efficiency of the shear wall are improved.

Description

TECHNICAL FIELD

[0001] The present application generally relates to the technical field of building engineering, and particularly relates to a UHPC prefabricated composite shear wall structure and a construction method thereof. BACKGROUND

[0002] In building engineering, prefabricated composite shear wall structures are widely used due to their high construction efficiency and controllable quality. However, there are many problems in the connection between existing prefabricated shear wall panels. On the one hand, the leveling process at the connection joint during panel assembly is complex, making it difficult to achieve accurate and rapid leveling. On the other hand, when the concrete is poured after the disassembly of the leveling device at the joint position, the flow of the concrete will impact the already leveled joint position, affecting the flatness between the prefabricated shear wall panels, often requiring secondary leveling, which seriously affects the construction period.

[0003] Currently, ultra-high performance concrete (UHPC) has been applied to prefabricated composite shear walls. However, in order to achieve high strength performance, existing UHPC usually uses fine aggregate to achieve close packing, resulting in a large self-weight and increasing the difficulty of construction. In addition, high cement usage can easily cause concrete shrinkage and cracking, affecting durability and service life, and also leading to excessive carbon emissions, which does not meet environmental protection requirements. Therefore, we propose a UHPC prefabricated composite shear wall structure and a construction method thereof to solve the above problems. SUMMARY

[0004] In view of the above defects or deficiencies in the prior art, it is desirable to provide a UHPC prefabricated composite shear wall structure and a construction method thereof that improve the mechanical properties and construction efficiency of the shear wall.

[0005] In a first aspect, the present application provides a UHPC prefabricated composite shear wall structure, comprising: a plurality of shear wall units used in cooperation, the shear wall units comprising first and second prefabricated composite shear walls connected by insertion, the first and second prefabricated composite shear walls having rear-poured grooves at adjacent end positions, respectively; a leveling unit arranged between the first and second prefabricated composite shear walls, the leveling unit comprising two threaded sleeves and a threaded connecting rod, the two threaded sleeves being pre-buried at the two rear-poured grooves, respectively, the threaded connecting rod having a first connecting segment and a second connecting segment, the first and second connecting segments having opposite thread directions, the first connecting segment being threadedly connected with a first connecting rod, and the second connecting segment being threadedly connected with a second connecting rod, the first and second connecting rods having adjustment sleeves at mutually distant ends, respectively, the two adjustment sleeves being connected with the two threaded sleeves through a leveling screw and a self-locking nut, respectively. A post-casting channel, wherein the post-casting channel is opened on the side wall of the post-casting groove, and the post-casting channel is connected to the plug-in connection position of the first prefabricated composite shear wall and the second prefabricated composite shear wall; the post-casting channel is used to transport grouting liquid to the plug-in connection position of the first prefabricated composite shear wall and the second prefabricated composite shear wall after the leveling unit leveled the first prefabricated composite shear wall and the second prefabricated composite shear wall.

[0006] According to the technical solution provided in this application, the first prefabricated composite shear wall and the second prefabricated composite shear wall both include: A prefabricated base having a well-shaped structure, comprising a plurality of main ribs arranged along a first direction and a plurality of secondary ribs arranged along a second direction, wherein the main ribs and the secondary ribs are connected at intersection nodes, and an installation space is enclosed between adjacent main ribs and the secondary ribs; the first direction and the second direction are arranged perpendicularly; UHPC prefabricated blocks, the number of which is equal to the number of the installation spaces; the UHPC prefabricated blocks are assembled at the installation spaces; Cast-in-situ anti-cracking concrete is poured on the prefabricated base and the UHPC prefabricated block, and the post-cast groove is formed at the end of the prefabricated composite shear wall.

[0007] According to the technical solution provided in this application, the components of the UHPC prefabricated block include at least: a gelling system, a polymer emulsion, fibers, water, quartz sand, and a polyhydroxy acid water reducer; The water-to-cement ratio of the gelling system and the water is 0.17, and the mortar-to-sand ratio of the gelling system and the quartz sand is 1; The cementitious system comprises cement, metakaolin and silica fume; the mass ratio of cement, metakaolin and silica fume in the cementitious system is 7:1:2; The maximum particle size of the quartz sand is 5 mm, and the gradation thereof is 292 parts by weight of 4-8 mesh sand, 222 parts by weight of 8-10 mesh sand, 139 parts by weight of 10-30 mesh sand, 102 parts by weight of 30-50 mesh sand, 72 parts by weight of 50-100 mesh sand, and 173 parts by weight of 100-120 mesh sand; The amount of the polyhydroxy acid water reducer added is 2% of the total mass of the gelling system.

[0008] According to the technical solution provided in this application, the polymer emulsion is an acrylic emulsion; the amount of the acrylic emulsion incorporated is 4% of the total mass of the gelling system; the fiber is copolymerized oxymethylene fiber, and the amount of the copolymerized oxymethylene fiber incorporated is 2% of the total volume of the UHPC prefabricated block.

[0009] According to the technical solution provided in this application, the method for preparing the UHPC prefabricated block includes the following steps: 700 parts of cement, 100 parts of metakaolin, and 200 parts of silica fume were added to a mixer in order according to weight parts, and then quartz sand graded to, by weight, 292 parts of 4-8 mesh sand, 222 parts of 8-10 mesh sand, 139 parts of 10-30 mesh sand, 102 parts of 30-50 mesh sand, 72 parts of 50-100 mesh sand, and 173 parts of 100-120 mesh sand was added to the mixer, and dry mixed at a first preset speed for 3 minutes to obtain a mixed dry material; While stirring at a first preset speed, 170 parts of water, 40 parts of acrylic emulsion, and 20 parts of polyhydroxy acid water reducer are added to the mixer according to parts by weight until they are stirred into a plastic state, and then 2% of the total volume of the UHPC prefabricated block is added to the mixer, and stirred at a second preset speed for 5 minutes, and then stirred at the first preset speed for 3 minutes to obtain a slurry; the first preset speed is less than the second preset speed; The slurry obtained after stirring is introduced into the test mold, and the mortar vibrating table is controlled to vibrate for a preset number of times to obtain a molded test block; The formed test block is placed in a standard curing box for curing to obtain the UHPC prefabricated block.

[0010] According to the technical solution provided in this application, the adjacent end surfaces of the first prefabricated composite shear wall and the second prefabricated composite shear wall form a splicing surface; The splicing surface of the first prefabricated composite shear wall is provided with at least two plug-in rods, and the splicing surface of the second prefabricated composite shear wall is provided with connecting grooves matching the plug-in rods; or, the splicing surface of the second prefabricated composite shear wall is provided with at least two plug-in rods, and the splicing surface of the first prefabricated composite shear wall is provided with connecting grooves matching the plug-in rods.

[0011] According to the technical solution provided in this application, the side wall of the plug rod is provided with a slide groove opened along its axial direction, the bottom of the slide groove is hingedly connected to one side of the wedge-shaped connecting piece, and an elastic element is further provided between the slide groove and the surface of the wedge-shaped connecting piece; When the plug-in rod is inserted into the connecting groove, the wedge-shaped connecting piece rotates relative to the sliding groove and abuts against the connecting groove.

[0012] According to the technical solution provided in the present application, it also includes: an exhaust hole, which is opened on the prefabricated composite shear wall having the post-casting channel; the exhaust hole is connected to the post-casting channel and the connecting groove.

[0013] According to the technical scheme provided in the application, the first connecting rod and the second connecting rod are both provided with a connecting hole threadedly connected with the threaded connecting rod; and the inner wall of the connecting hole is connected with the elastic retaining frame and the pawl ring. The first connecting section and the second connecting section are both provided with a ratchet tooth matched with the corresponding pawl ring, and the rotation directions of the ratchet teeth of the first connecting section and the second connecting section are opposite.

[0014] In a second aspect, the application provides a construction method of the UHPC prefabricated composite shear wall structure, including the following steps: The UHPC prefabricated blocks and the prefabricated shear wall units are prepared, the first prefabricated composite shear wall and the second prefabricated composite shear wall are hoisted, the insertion rod is inserted into the corresponding connecting groove, and the elastic clamping of the wedge-shaped connecting piece is used for preliminary positioning; The threaded connecting rod is rotated by using the externally applied force to adjust the vertical height of the first prefabricated composite shear wall and the second prefabricated composite shear wall to be consistent; and the threaded connecting rod is rotated by using the externally applied force to synchronously tighten the first connecting rod and the second connecting rod for horizontal direction fastening, and the self-locking nut is locked to fix the current leveling state; The gap between the insertion rod and the connecting groove is grouted with the grouting liquid through the post-pouring channel, and the air is discharged through the air vent until the concrete is hardened to form the UHPC prefabricated composite shear wall structure.

[0015] According to the above technical scheme, the application has at least the following beneficial effects: The application provides a UHPC prefabricated composite shear wall structure, including: a plurality of cooperatively used shear wall units, the shear wall unit including a first prefabricated composite shear wall and a second prefabricated composite shear wall connected by insertion, the first prefabricated composite shear wall and the second prefabricated composite shear wall having post-pouring grooves at the positions of the adjacent ends, respectively; a leveling unit arranged between the first prefabricated composite shear wall and the second prefabricated composite shear wall; the leveling unit including: two threaded sleeves and a threaded connecting rod; the two threaded sleeves being pre-buried at the post-pouring grooves, respectively; the threaded connecting rod having a first connecting section and a second connecting section, the threaded rotation directions of the first connecting section and the second connecting section being opposite, the first connecting section being threadedly connected with the first connecting rod, and the second connecting section being threadedly connected with the second connecting rod; the first connecting rod and the second connecting rod having adjustment sleeves at the ends away from each other, respectively; the two adjustment sleeves being connected with the two threaded sleeves through a leveling screw and a self-locking nut, respectively; a post-pouring channel being arranged in the side wall of the post-pouring groove and being in communication with the insertion connection position of the first prefabricated composite shear wall and the second prefabricated composite shear wall; the post-pouring channel being used for conveying grouting liquid to the insertion connection position of the first prefabricated composite shear wall and the second prefabricated composite shear wall after the first prefabricated composite shear wall and the second prefabricated composite shear wall are leveled by the leveling unit.

[0016] The present application designs the first connecting section and the second connecting section of the threaded connecting rod to have opposite thread rotation directions. By rotating the threaded connecting rod, the first connecting rod and the second connecting rod connected by the threaded connecting rod are synchronously moved toward or away from each other, ensuring the installation accuracy of the two prefabricated composite shear walls, and coordinating the adjustment of the leveling screw and the self-locking nut to avoid late displacement, so as to minimize the flatness error of the first prefabricated composite shear wall and the second prefabricated composite shear wall, and achieve high-precision position calibration under a small operating range. Furthermore, the post-cast groove in the present application is connected to the post-cast channel. After the leveling operation is completed, the slurry is continuously filled along the gap of the plug-in connection position and around the leveling unit through the post-cast channel, and then the various components of the adjustment unit are wrapped to form a steel-slurry composite force system, avoiding the connection node from becoming a weak force area, and improving the stability of the overall structure. The overall structural design of the present application takes into account both installation efficiency and connection strength, is suitable for prefabricated and assembled building construction, effectively reduces on-site work volume, and shortens the construction period. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Other features, objects and advantages of the present application will become more apparent from the detailed description of non-limiting embodiments made with reference to the following drawings.

[0018] Figure 1 Schematic diagram of UHPC prefabricated composite shear wall structure.

[0019] Figure 2 Schematic diagram of the leveling unit.

[0020] Figure 3 Schematic diagram of the prefabricated base.

[0021] Figure 4 Schematic diagram of the pawl ring and elastic retainer.

[0022] Figure 5 Schematic diagram of a ratchet.

[0023] Figure 6 Schematic diagram of a wedge-shaped connecting piece.

[0024] Figure 7 Flowchart of the construction method for UHPC precast composite shear wall structure.

[0025] Numbers in the figure: 1. First precast composite shear wall; 2. Second precast composite shear wall; 3. UHPC precast block; 4. Cast-in-place crack-resistant concrete; 5. Elastic element; 6. Main rib; 7. Secondary rib; 8. Post-cast groove; 9. Connecting rod; 10. Connecting groove; 11. Ratchet; 12. Threaded sleeve; 13. Leveling screw; 14. Adjusting sleeve; 15. Connecting hole; 16. First connecting rod; 17. Second connecting rod; 18. Threaded connecting rod; 19. Post-cast channel; 20. Self-locking nut; 21. Exhaust hole; 22. Ratchet ring; 23. Elastic retainer; 24. Wedge-shaped connecting piece. DETAILED DESCRIPTION

[0026] The present application will be further described in detail below with reference to the accompanying drawings and examples. It should be understood that the specific embodiments described herein are merely for the purpose of explaining the relevant invention and are not intended to limit the invention. It should also be noted that, for ease of description, only portions relevant to the invention are shown in the accompanying drawings.

[0027] It should be noted that, in the absence of conflict, the embodiments and features of the embodiments in this application can be combined with each other. The present application will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0028] like Figure 1 As shown, the present application provides a UHPC prefabricated composite shear wall structure, comprising: A plurality of shear wall units for use in combination, the shear wall units comprising a first prefabricated composite shear wall 1 and a second prefabricated composite shear wall 2 connected by plugging, the first prefabricated composite shear wall 1 and the second prefabricated composite shear wall 2 respectively having post-cast grooves 8 at adjacent end positions; A leveling unit is provided between the first prefabricated composite shear wall 1 and the second prefabricated composite shear wall 2. The leveling unit comprises two threaded sleeves 12 and a threaded connecting rod 18. The two threaded sleeves 12 are respectively embedded in the two post-cast grooves 8. The threaded connecting rod 18 comprises a first connecting section and a second connecting section. The threads of the first and second connecting sections have opposite directions of rotation. The first connecting section is threadedly connected to the first connecting rod 16, and the second connecting section is threadedly connected to the second connecting rod 17. Adjustment sleeves 14 are respectively provided at the ends of the first and second connecting rods 16 and 17 that are away from each other. The two adjustment sleeves 14 are respectively connected to the two threaded sleeves 12 via a leveling screw 13 and a self-locking nut 20. The post-casting channel 19 is opened on the side wall of the post-casting groove 8, and the post-casting channel 19 is connected to the plug-in connection position of the first prefabricated composite shear wall 1 and the second prefabricated composite shear wall 2; the post-casting channel 19 is used to transport the grouting liquid to the plug-in connection position of the first prefabricated composite shear wall 1 and the second prefabricated composite shear wall 2 after the leveling unit leveled the first prefabricated composite shear wall 1 and the second prefabricated composite shear wall 2.

[0029] Wherein, the number of shear wall units is two, three or more, each shear wall unit comprises a first prefabricated composite shear wall 1 and a second prefabricated composite shear wall 2; adjacent shear wall units can be connected by the assembly mode between the first prefabricated composite shear wall 1 and the second prefabricated composite shear wall 2, forming a continuous overall structure.

[0030] The first prefabricated composite shear wall 1 and the second prefabricated composite shear wall 2 adopt a plug-in connection form, specifically, as shown in Figure 1 The adjacent end faces of the first prefabricated composite shear wall 1 and the second prefabricated composite shear wall 2 form a splicing surface; the splicing surface serves as a reference surface for connection, ensuring close fitting when splicing.

[0031] The splicing surface of the first prefabricated composite shear wall 1 is provided with at least two plug-in rods 9, and the splicing surface of the second prefabricated composite shear wall 2 is provided with a connecting groove 10 matched with the plug-in rod 9; or, the splicing surface of the second prefabricated composite shear wall 2 is provided with at least two plug-in rods 9, and the splicing surface of the first prefabricated composite shear wall 1 is provided with a connecting groove 10 matched with the plug-in rod 9.

[0032] Wherein, the plug-in connection of the two prefabricated composite shear walls adopts a one-way plug-in design, which has two symmetrical structural forms: The first form: the splicing surface of the first prefabricated composite shear wall 1 is provided with at least two plug-in rods 9 (usually steel reinforced concrete or steel rods, uniformly distributed in the vertical or horizontal direction), and the splicing surface of the second prefabricated composite shear wall 2 is provided with a connecting groove 10 matched in size with the plug-in rod 9 at the corresponding position, and the depth of the connecting groove 10 is greater than the length of the plug-in rod 9, leaving a grouting gap.

[0033] The second form: symmetrical to the first form, the splicing surface of the second prefabricated composite shear wall 2 is provided with plug-in rods 9, and the splicing surface of the first prefabricated composite shear wall 1 is provided with connecting grooves 10.

[0034] The above two forms have the same function, both of which realize the preliminary mechanical connection of the two shear walls by the way of rod into groove, avoiding horizontal or vertical misalignment during splicing.

[0035] It should be noted that the plug-in rod 9 is, for example, cylindrical or square in cross-section, and its length can be designed according to the thickness of the shear wall, generally 100-300mm, and the surface can be provided with rough texture such as threads or protrusions to enhance the bonding force with the later grouting paste. The number of plug-in rods 9 is at least two, which are uniformly distributed along the splicing surface, such as one above and one below, to ensure the parallelism of the splicing surface through multi-point positioning. The groove cross-section of the connecting groove 10 matches the plug-in rod 9, and the gap is controlled within 5-10mm, leaving space for grouting, and the bottom is provided with a circular arc transition to avoid stress concentration, and the inner wall can be embedded with metal mesh or roughened to improve the bonding strength with the paste.

[0036] During hoisting, the plug-in rod 9 is inserted into the connecting groove 10 to quickly determine the relative position of the two prefabricated composite shear walls, replacing the traditional temporary support positioning method, shortening the initial alignment time to less than 10 minutes, and greatly improving construction efficiency. In the plug-in state, the plug-in rod 9 can transmit part of the vertical shear force, such as the deadweight load during hoisting, to avoid collision or displacement of the shear wall due to shaking before leveling, and provide a stable foundation for subsequent leveling operations. In addition, after the gap between the plug-in rod 9 and the connecting groove 10 is poured with slurry through the post-casting channel 19, a rod-slurry-groove composite structure is formed. The hardened slurry connects the plug-in rod and the groove as a whole, which increases the shear bearing capacity of the node by more than 40%, far exceeding traditional bolt connections or welded nodes.

[0037] Compared with the flange connection or welding connection of traditional prefabricated shear walls, this plug-in connection form allows the plug-in rod 9 and the connecting groove 10 to be formed during prefabrication in the factory, with controllable dimensional accuracy (error ≤ 1mm), avoiding quality fluctuations in on-site processing; reducing the workload of high-altitude open flame operations and bolt tightening, reducing construction safety risks, and complying with the "green construction" concept of prefabricated buildings; if the plug-in rod 9 and the connecting groove 10 are slightly damaged during transportation, they can be restored to function through on-site repair (such as filling with high-strength mortar) without the need to replace the entire component.

[0038] Furthermore, if Figure 6 As shown, the side wall of the plug rod 9 is provided with a slide groove opened along its axial direction, the bottom of the slide groove is hingedly connected to one side of the wedge-shaped connecting piece 24, and an elastic element 5 is further provided between the slide groove and the surface of the wedge-shaped connecting piece 24; When the plug-in rod 9 is inserted into the connecting groove 10 , the wedge-shaped connecting piece 24 rotates relative to the sliding groove and abuts against the connecting groove 10 .

[0039] Among them, the slide groove is machined on the side wall along the axial direction of the plug-in rod 9, and the cross-section is "U"-shaped. The depth and width must match the size of the wedge-shaped connecting piece 24 to ensure that the wedge-shaped connecting piece 24 can rotate flexibly in the groove. The wedge-shaped connecting piece 24 is made of metal sheet, such as spring steel; one end of the wedge-shaped connecting piece 24 is a hinged end, and the other end is a wedge-shaped free end (with a triangular cross-section and smooth edges), which has a certain elastic deformation ability. The wedge-shaped connecting piece 24 is connected to the bottom of the slide groove through a hinge axis and can rotate around the hinge axis. Its rotation angle is usually designed to be 0°-30°. The elastic element 5 is located between the inner wall of the slide groove and the surface of the wedge-shaped connecting piece 24. The elastic element 5 is, for example, a compression spring or an elastic rubber block. In the natural state, the elastic element 5 is in a slightly compressed state, exerting an outward thrust on the wedge-shaped connecting piece 24, causing the free end of the wedge-shaped connecting piece to protrude from the side wall of the plug-in rod 9.

[0040] In the splicing process of the first prefabricated composite shear wall 1 and the second prefabricated composite shear wall 2, when the insertion rod 9 begins to enter the connecting groove 10, the wedge-shaped free end of the wedge-shaped connecting piece 24 first contacts the entrance edge of the connecting groove 10. Because the wedge-shaped connecting piece 24 protrudes from the side wall of the insertion rod 9, the edge of the connecting groove 10 will exert an inward pressure on it. Under the action of the pressure, the wedge-shaped connecting piece 24 rotates to the inside of the sliding groove around the hinge shaft, while compressing the elastic element 5, and the wedge-shaped connecting piece 24 gradually retracts into the sliding groove, avoiding rigid collision with the inner wall of the groove, and ensuring that the insertion rod 9 can be smoothly inserted to the preset depth. When the insertion rod 9 is completely inserted into the connecting groove 10, the wedge-shaped connecting piece 24 is released from the pressure of the groove entrance, and the elastic element 5 releases the elastic force to push the wedge-shaped connecting piece 24 to rotate outward around the hinge shaft until the wedge-shaped free end tightly abuts against the inner wall of the connecting groove 10. At this time, the normal pressure between the wedge-shaped connecting piece 24 and the inner wall of the connecting groove 10 is generated, forming a static friction force. In the abutting state, the friction force between the wedge-shaped connecting piece 24 and the inner wall of the connecting groove 10 can limit the axial movement and radial movement of the insertion rod 9 in the groove, so that the two shear walls remain relatively fixed before leveling, reducing the need for temporary support. Moreover, if there is a slight size deviation between the insertion rod 9 and the connecting groove 10, such as manufacturing error or transportation deformation, the elastic force of the elastic element 5 can adaptively compensate for the gap by adjusting the rotation angle of the wedge-shaped connecting piece 24, ensuring that the wedge-shaped connecting piece 24 is always in close contact with the inner wall of the connecting groove 10, avoiding looseness.

[0041] In addition, the close contact between the wedge-shaped connecting piece 24 and the inner wall of the connecting groove 10 can reduce the gap space before grouting, making it easier for the slurry injected through the post-pouring channel 19 to fill the remaining gaps; at the same time, the connecting piece can block part of the air channel, cooperating with the exhaust hole 21 to improve the grouting density. After grouting and hardening, the wedge-shaped connecting piece 24 is wrapped in the slurry, forming a metal slurry composite stress structure with the insertion rod 9 and the connecting groove 10, and the wedge-shaped design can transfer part of the shear force, improving the shear bearing capacity of the joint.

[0042] Further, as shown in Figure 3 the first prefabricated composite shear wall 1 and the second prefabricated composite shear wall 2 each include: The prefabricated base has a crisscross structure and includes a plurality of primary ribs 6 arranged along a first direction and a plurality of secondary ribs 7 arranged along a second direction. The primary ribs 6 and secondary ribs 7 are snap-connected at their intersections, and installation spaces are defined between adjacent primary ribs 6 and secondary ribs 7. The first and second directions are perpendicular to each other. Here, the first direction is, for example, perpendicular to the length of the primary ribs 6, and the second direction is, for example, perpendicular to the length of the secondary ribs 7. The snap-connection method at the intersections of the primary and secondary ribs 6 and 7 is, for example, to reserve slots on the primary ribs 6, with the slots at the same position on all primary ribs 6 arranged along the first direction. The secondary ribs 7 are snapped into the slots at the same position on the primary ribs 6, one by one, to achieve snap connection between the primary and secondary ribs 6 and 7. Once the primary and secondary ribs 6 and 7 are snap-connected, installation spaces are defined between adjacent primary and secondary ribs 6 and 7, resulting in multiple installation spaces. The dimensions of these installation spaces match the dimensions of the UHPC prefabricated block 3. In addition, the main ribs 6 and the secondary ribs 7 are prefabricated with reinforced concrete, for example, and have rigidity and toughness. Moreover, the crisscross structure formed by the main ribs 6 and the secondary ribs 7 can also disperse the force path, thereby reducing material usage (reducing weight by more than 30% compared to a solid wall) and improving the anti-lateral displacement performance.

[0043] UHPC prefabricated blocks 3, the number of which is equal to the number of installation spaces; UHPC prefabricated blocks 3 are assembled in the installation spaces; wherein, after being embedded in the installation spaces, the UHPC prefabricated blocks 3 form a coordinated force-bearing system with the main ribs 6 and secondary ribs 7. When subjected to force, the main ribs 6 and secondary ribs 7 bear the transverse / longitudinal shear force, while the UHPC prefabricated blocks 3 bear the main pressure, thereby greatly improving the overall bearing capacity of the structure.

[0044] Cast-in-place anti-cracking concrete 4 is poured onto the precast base and UHPC precast blocks 3, forming a post-cast groove 8 at the end of the resulting precast composite shear wall. Here, the cast-in-place anti-cracking concrete is poured onto the surfaces and gaps between the precast base and the UHPC precast blocks 3. After hardening, the dispersed precast components are bonded together to form a complete precast composite shear wall, preventing relative displacement of the components under stress. Furthermore, during the pouring process, a post-cast groove 8 is reserved at the joint between one precast composite shear wall and another using a mold. The size and position of the post-cast groove 8 must match the pre-embedded threaded sleeve 12 of the leveling unit, providing space for subsequent grouting connections.

[0045] The leveling unit comprises two threaded sleeves 12 and a threaded connecting rod 18. The two threaded sleeves 12 are embedded in the two post-cast grooves 8 respectively, serving as the fixed base points of the leveling unit and the corresponding prefabricated composite shear walls. The threaded connecting rod 18 has a first connecting section and a second connecting section, and the threads of the two connecting sections are opposite in rotation direction. The first connecting rod 16 and the second connecting rod 17 are respectively threaded with the two connecting sections, and the ends of the first connecting rod 16 and the second connecting rod 17 away from the threaded connecting rod 18 are respectively provided with an adjusting sleeve 14. The leveling screw 13 is connected with the threaded sleeve 12 through the adjusting sleeve 14, and cooperates with the self-locking nut 20 to realize vertical height locking. Specifically, when the threaded connecting rod 18 is rotated by external force, the first and second connecting rods will move synchronously towards each other (tighten) or away from each other (loosen) due to the opposite rotation direction of the threads of the two connecting sections, thereby realizing the precise alignment of the first prefabricated composite shear wall 1 and the second prefabricated composite shear wall 2 in the horizontal direction (such as controlling the flatness error within millimeter level). The horizontal direction here refers to the coplanar of the surfaces of the two prefabricated composite shear walls on the same side. Here, the tool for applying external force is, for example, a special wrench. By rotating the leveling screw 13 to adjust the relative position of the adjusting sleeve 14 and the threaded sleeve 12, and locking it with the self-locking nut 20, the vertical height of the two prefabricated composite shear walls can be ensured to be consistent, thereby avoiding later settlement or displacement. Here, the vertical direction refers to the thickness direction of the prefabricated composite shear wall.

[0046] Further, as shown in Figure 4 the first connecting rod 16 and the second connecting rod 17 are both provided with a connecting hole 15 threaded with the threaded connecting rod 18. The inner wall of the connecting hole 15 is connected with the elastic retainer 23 and the pawl ring 22. The first connecting section and the second connecting section are both provided with a ratchet 11 matched with the corresponding pawl ring 22, and the rotation directions of the ratchets 11 of the first connecting section and the second connecting section are opposite.

[0047] It should be noted that the ends of the first connecting rod 16 and the second connecting rod 17 are both provided with a connecting hole 15, and the inner wall of the connecting hole 15 is provided with internal threads matched with the external threads (first connecting section, second connecting section) of the threaded connecting rod 18, thereby achieving preliminary connection through thread rotation. Moreover, the connecting hole 15 is not only a channel for force transmission, but also a mounting carrier for the anti-loose structure, and the inner wall thereof is provided with an annular groove for fixing the elastic retainer 23 and the pawl ring 22. Here, the anti-loose structure refers to the pawl ring 22 and the ratchet 11.

[0048] The pawl ring 22 is an annular component, and the inner side of the pawl ring 22 is provided with a plurality of one-way inclined pawls (similar to a ratchet structure), the direction of the pawls matches the ratchet teeth 11 on the threaded connecting rod 18, and only allows the threaded connecting rod to rotate in a specific direction (such as the tightening direction), and when reversely rotating, the pawl ring 22 is clamped. The elastic retainer 23 is made of elastic material (such as spring steel sheet), and is installed between the inner wall of the connecting hole 15 and the pawl ring 22. The elastic retainer 23 functions to ensure that the pawl ring 22 is tightly attached to the ratchet teeth 11 of the threaded connecting rod 18 by continuously exerting radial elastic force, so as to avoid disengagement caused by vibration or stress. The outer surfaces of the first connecting section and the second connecting section of the threaded connecting rod 18 are both provided with ratchet teeth 11, which are sawtooth structures distributed along the axial direction. Among them, the ratchet teeth 11 of the first connecting section and the ratchet teeth 11 of the second connecting section are opposite in rotation direction (such as the ratchet teeth of the first connecting section are inclined clockwise, and the ratchet teeth of the second connecting section are inclined counterclockwise), which corresponds to the direction of the pawls of the two connecting rod inner pawl rings 22.

[0049] When it is necessary to tighten the first prefabricated composite shear wall 1 and the second prefabricated composite shear wall 2, the threaded connecting rod 18 is rotated, the first connecting section drives the first connecting rod 16 to move towards the threaded connecting rod 18, and the second connecting section drives the second connecting rod 17 to move synchronously (because the rotation directions of the threads are opposite). At this time, the pawls of the pawl ring 22 slide along the inclined direction of the corresponding ratchet teeth 11 (without being clamped), and the elastic retainer 23 is slightly compressed, allowing the two connecting rods to rotate relative to the threaded connecting rod 18, realizing horizontal tension leveling. When the leveling is completed and the load (such as earthquake, wind) is borne, if the threaded connecting rod 18 has a reverse rotation trend, at this time, the ratchet teeth 11 of the first connecting section will be clamped with the pawls of the first connecting rod 16 inner pawl ring 22, and the ratchet teeth 11 of the second connecting section will be clamped with the pawls of the second connecting rod 17 inner pawl ring 22; due to the one-way locking characteristics of the pawls and the ratchet teeth, the reverse rotation is completely prevented, and the elastic force of the elastic retainer 23 ensures that the clamping is tight, avoiding loosening. In addition, after grouting, the grout wraps the pawl ring 22, the elastic retainer 23 and other components, further combining mechanical anti-loosening with material bonding, forming a steel-grout composite locking form, so that the shear strength of the connecting joint is improved by more than 40%.

[0050] The post-pouring channel 19 is arranged on the side wall of the post-pouring groove 8, one end of the post-pouring channel 19 is communicated with the insertion connection position of the two prefabricated composite shear walls (i.e. the gap between the insertion rod 9 and the connection groove 10), and the other end can be externally connected to the grouting equipment. After leveling is completed, high-strength grouting material is poured into the insertion gap and the post-pouring groove 8 through the post-pouring channel 19, so that the grout body wraps each component of the leveling unit and fills the insertion gap, forming a steel grout concrete integrated structure. After grouting, the strength of the connection joint is not less than that of the shear wall body, avoiding the problem of weak joints in traditional splicing; at the same time, the grout body is further fixed after hardening, realizing secondary fastening. Here, the post-pouring channel 19 is arranged obliquely, and the oblique angle is, for example, 15° downward horizontally.

[0051] Further, as shown in Figure 1 the application further includes: an exhaust hole 21 arranged on the prefabricated composite shear wall with the post-pouring channel 19; the exhaust hole 21 is communicated with the post-pouring channel 19 and the connection groove 10.

[0052] Here, the diameter and orientation of the exhaust hole 21 can be designed according to the grouting amount and channel size, for example, a cylindrical through hole with a diameter of 10-20 mm, and the orientation needs to ensure that it forms a through path with the post-pouring channel 19 and the connection groove 10, avoiding bending or blockage. One end of the exhaust hole 21 is connected with the post-pouring channel 19, ensuring that when grouting, the grout body is injected from the bottom of the post-pouring channel 19, and the gas can be discharged through the exhaust hole 21; the other end of the exhaust hole 21 extends to the top area of the connection groove 10, directly communicating with the gap between the insertion rod 9 and the connection groove 10, and can discharge the air trapped in the connection groove 10, avoiding the air in the gap which cannot be discharged, forming air bubbles or cavities, resulting in uneven stress on the connection joint. In addition, during the grouting process, when the grout body overflows from the exhaust hole 21, it can be directly judged that the connection groove 10 and the post-pouring channel 19 have been filled with grout, at which time the grouting can be stopped, avoiding excessive grouting leading to material waste or excessive pressure damaging the wall. The dense grout body without air bubbles can be closely combined with the insertion rod 9, the inner wall of the connection groove 10 and the leveling unit, forming a steel grout concrete integrated force system, avoiding interface peeling caused by air trapping, and significantly improving the shear strength and durability of the joint.

[0053] Further, the components of the UHPC prefabricated block 3 at least include: a cementitious system, a polymer emulsion, fibers, water, quartz sand and polyhydroxy acid water reducing agent; The water-binder ratio of the cementitious system and water is 0.17, and the binder-sand ratio of the cementitious system and quartz sand is 1; The cementitious system includes cement, metakaolin and silica fume; the mass ratio of the cement, metakaolin and silica fume in the cementitious system is 7:1:2; The maximum particle size of the quartz sand is 5 mm, and the gradation is 292 parts of 4-8 mesh sand, 222 parts of 8-10 mesh sand, 139 parts of 10-30 mesh sand, 102 parts of 30-50 mesh sand, 72 parts of 50-100 mesh sand, and 173 parts of 100-120 mesh sand by weight; The incorporation amount of the polyhydroxy acid water reducing agent is 2% of the total mass of the cementitious system.

[0054] Specifically, the cementitious system is the core of strength formation, which builds the hardened skeleton through hydration reaction to provide the basic mechanical properties for the UHPC precast block 3. The quartz sand as fine aggregate fills the internal gaps of the material, optimizes the compactness, and enhances the structural stability. The polymer emulsion is used to improve the interfacial bonding performance between components and enhance the toughness and crack resistance of the material. The fiber is used to inhibit the generation and expansion of cracks and enhance the bending and impact resistance of the UHPC precast block 3. Water is used to participate in the hydration reaction of the cementitious system and adjust the fluidity of the paste for easy construction and molding. The polyhydroxy acid water reducing agent is used to reduce the water consumption while ensuring the good fluidity of the paste, which helps to improve the material strength.

[0055] The water-binder ratio of 0.17 means that the mass ratio of the cementitious system to water is 0.17; this ratio is much lower than that of ordinary concrete, and by using a low water-binder ratio, the porosity of the material can be significantly reduced, thereby greatly improving the strength. At the same time, with the use of the polyhydroxy acid water reducing agent, the problem of dry paste caused by low water content can be avoided, ensuring that the paste has appropriate fluidity during the construction process.

[0056] The cement-sand ratio of 1 means that the ratio of the total mass of the cementitious system to the total mass of the quartz sand is 1; this equal mass ratio design can achieve tight packing of the fine aggregate, allowing the cementitious material to fully fill the gaps between the sand particles, forming a high-density structure, and thereby improving the impermeability and durability of the material.

[0057] The cementitious system includes cement, metakaolin, and silica fume, with a mass ratio of 7:1:2. Among them, the cement accounts for 70%, as the main cementitious material, which provides the basic strength through hydration reaction; the metakaolin accounts for 10%, as an auxiliary cementitious material, which can generate additional gel through secondary hydration reaction to improve the late strength and sulfate resistance of the material; the silica fume accounts for 20%, whose ultra-fine particles can fill the gaps between the cement particles, participate in the hydration reaction, and enhance the compactness of the interfacial transition zone, thereby improving the early strength and impermeability of the material.

[0058] The maximum particle size of quartz sand is 5 mm, and multi-level mixing is adopted, and the proportion of each particle size range is as follows: 4-8 mesh sand 292 parts, 8-10 mesh sand 222 parts, 10-30 mesh sand 139 parts, 30-50 mesh sand 102 parts, 50-100 mesh sand 72 parts, and 100-120 mesh sand 173 parts. This continuous grading design can realize the close packing of "coarse sand-medium sand-fine sand", reduce the internal pores through the mutual filling of sand particles of different sizes, and improve the density of the material.

[0059] The incorporation amount of polyhydroxy acid water reducing agent is 2% of the total mass of the cementitious system. This proportion can effectively disperse the cementitious material particles, ensure the slurry has good fluidity under low water-binder ratio, ensure that the slurry can smoothly fill all parts of the mold, and at the same time reduce the bleeding phenomenon and avoid problems such as sanding on the surface of the material.

[0060] This proportioning design realizes the optimization of multiple performances. Low water-binder ratio combined with high-activity cementitious materials ensures the ultra-high strength of the material, and the use of fibers and polymer emulsion improves the brittleness of traditional high-strength concrete and enhances the toughness of the material. The continuous grading of quartz sand and the low water-binder ratio reduce the internal pores, and the polymer emulsion optimizes the interfacial transition zone, making the material have excellent impermeability and crack resistance, which can meet the waterproofing requirements of shear walls. In addition, the use of water reducing agent to adjust the fluidity of the slurry ensures the feasibility of construction, and the low water consumption reduces the hardening shrinkage, avoiding cracking after the prefabricated block is formed.

[0061] Further, the polymer emulsion is an acrylic emulsion; the incorporation amount of the acrylic emulsion is 4% of the total mass of the cementitious system; the fiber is a co-polyoxymethylene fiber, and the incorporation amount of the co-polyoxymethylene fiber is 2% of the total volume of the UHPC prefabricated block 3.

[0062] It should be noted that the acrylic emulsion is the core component of interface modification and toughness improvement. The acrylic emulsion is a high-molecular polymer water dispersion, which has good adhesion, flexibility and chemical stability. Its molecular chain can form physical adsorption or chemical combination with inorganic cementitious materials (cement, silica fume, etc.). The incorporation amount of the acrylic emulsion is 4% of the total mass of the cementitious system, i.e. 4 parts of acrylic emulsion correspond to 100 parts of cementitious material. This proportion has been verified by experiments: it can ensure the modification effect, and will not cause the strength of the material to decrease due to excessive incorporation (excessive incorporation of polymer will dilute the concentration of cementitious materials).

[0063] In ordinary concrete, the interfacial transition zone between aggregate and cementitious material becomes a weak link due to the directional arrangement of Ca(OH)2 crystals. The high-molecular chains of the acrylic emulsion can be adsorbed on the surface of the cementitious particles, reducing the enrichment of Ca(OH)2 at the interface, forming a more dense transition zone, and improving the crack resistance and impermeability of the UHPC prefabricated block (the impermeability grade can reach above P25).

[0064] The acrylic emulsion forms an elastic film after drying, which is distributed in the pores of the gelled system. When the material is subjected to external force, the film can absorb energy through deformation to relieve stress concentration, so that the breaking elongation of the UHPC prefabricated block is increased to 3-5 times that of ordinary high-strength concrete, and brittle failure is avoided.

[0065] The surface active ingredients in the acrylic emulsion can assist the water reducing agent to play a role, further improve the fluidity and water retention of the slurry, reduce the bleeding phenomenon during mixing, and ensure the dense filling of the corner parts of the UHPC prefabricated block 3 during molding.

[0066] Copolymerized formaldehyde fiber is the key skeleton material for enhancing mechanical properties. Copolymerized formaldehyde fiber is a high-strength synthetic fiber with excellent tensile strength (≥800 MPa), corrosion resistance (acid and alkali resistance, organic solvent resistance), and compatibility with cement-based materials. Its surface is specially treated to enhance the adhesion to the gelled system. The copolymerized formaldehyde fiber has a mixing amount of 2% of the total volume of the UHPC prefabricated block 3, i.e. the fiber volume ratio is 2%. This ratio is determined by balancing dispersibility and enhancement effect. If it is lower than 2%, the fiber bridging effect is insufficient and cannot effectively inhibit cracks; if it is higher than 2%, fiber agglomeration is easy to occur, which reduces the homogeneity of the material.

[0067] When the UHPC prefabricated block 3 produces microcracks due to shrinkage or stress, the uniformly distributed copolymerized formaldehyde fiber can transfer stress through the bridging effect to prevent further expansion of the cracks. Tests show that the crack width can be controlled within 0.05 mm, which is especially suitable for components such as shear walls that are easily affected by temperature stress. The fiber forms a three-dimensional random support system inside the material, which can significantly improve the breaking strength (by 30-40%) and impact resistance (impact toughness is 10-15 times that of ordinary concrete) of the UHPC prefabricated block 3, meeting the mechanical requirements of shear walls under dynamic loads such as earthquakes.

[0068] The fiber and the acrylic emulsion work together to form an organic-inorganic composite reinforcement network. The emulsion improves the interfacial adhesion between the fiber and the gelled material, and the fiber bears the tensile stress through its high strength, so that the UHPC prefabricated block exhibits "plastic deformation" characteristics under load, rather than sudden fracture.

[0069] The combination of acrylic emulsion and copolymerized formaldehyde fiber is not a simple performance superposition, but achieves the effect of 1+1>2 through synergistic effect. The emulsion optimizes the interfacial adhesion between the fiber and the gelled system to ensure that the fiber can effectively transfer stress when subjected to stress; the fiber reduces the local stress concentration of the emulsion film through physical support, and the two together improve the integrity of the material.

[0070] The low water-cement ratio and highly active cementitious materials ensure the ultra-high strength of UHPC precast blocks (compressive strength ≥150MPa), while acrylic emulsion and copolymerized acetal fiber make up for the brittle defects of traditional high-strength concrete, giving the material both high strength and high toughness, perfectly adapting to the dual requirements of precast composite shear walls for bearing capacity and seismic performance.

[0071] The 2% by volume fiber can be evenly dispersed through high-speed stirring (combined with a second preset speed stirring process), and the 4% by mass emulsion does not significantly increase the slurry viscosity. Both are suitable for large-scale production in factory prefabrication, ensuring the quality stability of UHPC prefabricated blocks.

[0072] Furthermore, the preparation method of the UHPC prefabricated block 3 includes the following steps: Step 1. Add 700 parts of cement, 100 parts of metakaolin, and 200 parts of silica fume to the mixer in order according to weight, and then add quartz sand graded to 292 parts of 4-8 mesh sand, 222 parts of 8-10 mesh sand, 139 parts of 10-30 mesh sand, 102 parts of 30-50 mesh sand, 72 parts of 50-100 mesh sand, and 173 parts of 100-120 mesh sand into the mixer, and dry mix at a first preset speed for 3 minutes to obtain a mixed dry material.

[0073] Among them, the cementitious materials (cement, metakaolin, silica fume) are added first, and then the quartz sand is added to prevent the fine aggregate (such as 100 mesh-120 mesh sand) from being thrown out by high-speed stirring, ensuring that the dry materials are evenly mixed.

[0074] Low-speed dry mixing can reduce dust flying, and at the same time allow solid particles of different densities (such as silica fume density 2.2g / cm³, cement density 3.1g / cm³) to achieve initial dispersion through gravity sedimentation and mechanical stirring, laying the foundation for subsequent mixing with liquid components.

[0075] Experimental verification shows that a 3-minute stirring time can control the component deviation at any sampling point in the dry material within ±2%, ensuring material homogeneity.

[0076] Step 2: While stirring at a first preset speed, add 170 parts of water, 40 parts of acrylic emulsion, and 20 parts of polyhydroxy acid water reducer to the mixer according to parts by weight until they are stirred into a plastic state. Then, add copolymer formaldehyde fiber accounting for 2% of the total volume of the UHPC prefabricated block 3 to the mixer, stir at a second preset speed for 5 minutes, and then stir at the first preset speed for 3 minutes; the first preset speed is less than the second preset speed.

[0077] Among them, water, acrylic emulsion (4% of the mass of the gelling system), polyhydroxy acid water reducing agent (2% of the mass of the gelling system) need to be added under low-speed stirring to avoid liquid splashing; the polyhydroxy acid water reducing agent disperses the gelling particles, and under a low water-binder ratio (0.17), the slurry can still reach a plastic state (extension ≥ 250 mm), ensuring uniform dispersion of the subsequent fibers.

[0078] After adding the copolyformal fiber, switch to high-speed stirring (second preset speed): use strong shear force to break the fiber agglomerates, so that the fibers form a three-dimensional random distribution in the slurry (fiber spacing uniformity improved by more than 40%), and a 5-minute duration can ensure that more than 95% of the fiber filaments are dispersed.

[0079] Finally, return to low-speed stirring to eliminate the air bubbles generated by high-speed stirring, and at the same time, let the slurry restore a stable cohesive state to avoid directional arrangement of the fibers due to high-speed rotation, and ensure consistent mechanical properties in all directions.

[0080] Here, the difference between the first preset speed (low speed) and the second preset speed (high speed) (such as a difference of 500 r / min) is the core design of the scheme, which uses low speed to ensure gentle mixing of components and high speed to achieve fiber dispersion, both of which ensure material uniformity and avoid excessive stirring that causes the slurry to heat up (temperature rise accelerates cement hydration, affecting construction time).

[0081] Step 3, introduce the obtained slurry into the mold, and control the vibrating table to vibrate at a preset number of times to obtain a shaped test block.

[0082] Among them, the size of the mold is consistent with the design of the precast block to be formed, and the preset number of times is, for example, 20-30 times.

[0083] Vibration causes the slurry to produce a liquefaction effect, temporarily improving flowability, and can fill the corners and other fine parts of the mold to avoid the formation of cavities or honeycombs.

[0084] The vibration is preset to, for example, 20-30 times. If the vibration is too little, air bubbles cannot be completely removed, and residual air bubbles will reduce the strength. If the vibration is too much, it may cause aggregate settlement, separation of quartz sand and cementitious materials, and affect material homogeneity.

[0085] The mold needs to be coated with a release agent in advance to ensure that the surface of the shaped test block is smooth and reduce the workload of post-processing.

[0086] Step 4, place the shaped test block in a standard curing box for curing to obtain the UHPC precast block 3.

[0087] Here, the standard curing box has a control temperature of, for example, 20±2℃ and a relative humidity of, for example, ≥95%, which provides the best environment for cement hydration, especially the secondary hydration of silica fume and metakaolin, to ensure that the 28-day compressive strength meets the standard (≥150 MPa).

[0088] During the curing process, the acrylic emulsion gradually loses water and solidifies, forming an elastic film on the surface of the cementitious system and the fiber, further enhancing the interfacial bonding; the co-polyoxymethylene fiber remains dimensionally stable in a humid environment, avoiding interface cracks caused by dry shrinkage. The curing period is usually no less than 28 days to ensure that the hydration reaction proceeds fully and the material properties tend to be stable, meeting the precast block factory strength requirements (compressive strength ≥ 90% of the design value).

[0089] This scheme controls the performance fluctuation range of the precast block to within ± 5% by standardizing the step-by-step stirring of dry materials to wet materials, the number of vibrations, and the curing environment, which is much lower than the quality deviation of site pouring. The reasonable design of total stirring time, vibration frequency, and curing period ensures performance while controlling the production cycle of a single precast block to within 30 days, meeting the needs of large-scale construction. Moreover, the process design fully adapts to the characteristics of acrylic emulsion (interfacial modification) and co-polyoxymethylene fiber (reinforcement), allowing them to play their optimal roles in the precast block. Tests show that the precast block prepared by this process has a 25% increase in flexural strength and a 30% increase in crack resistance compared to traditional processes.

[0090] As shown in Figure 7 The present application provides a construction method of a UHPC precast composite shear wall structure, comprising the following steps: S100, preparing UHPC precast blocks 3 and precast shear wall units, hoisting a first precast composite shear wall 1 and a second precast composite shear wall 2, inserting a plug-in rod 9 into a corresponding connecting groove 10, and preliminarily positioning by elastic clamping of a wedge-shaped connecting piece 24.

[0091] First, the UHPC precast blocks 3 are prepared according to the formula and process to ensure that their strength and dimensional accuracy meet the standards (compressive strength ≥ 150 MPa, dimensional error ≤ 1 mm). Then, the precast shear wall units are assembled, the UHPC precast blocks 3 are assembled in the mounting space of the cross-shaped precast base, the cast-in-place crack-resistant concrete 4 is poured, and the first precast composite shear wall 1 and the second precast composite shear wall 2 with post-cast grooves 8, plug-in rods 9 or connecting grooves 10 are formed, and the precise embedding of leveling unit embedded parts such as threaded sleeves 12 is completed at the same time.

[0092] Two precast shear walls are hoisted to the mounting position using lifting equipment, and the plug-in rod 9 and the connecting groove 10 are matched to achieve preliminary alignment. The plug-in rod 9 is inserted into the corresponding connecting groove 10 without the need for temporary support to achieve basic fixation.

[0093] During insertion, the inner wall of the connecting groove 10 squeezes the wedge-shaped connecting piece 24 to rotate around the hinge axis, compressing the elastic element 5; after being fully inserted, the elastic element 5 rebounds and pushes the wedge-shaped connecting piece 24 to tightly contact the inner wall of the connecting groove 10, limiting the lateral and vertical movement of the shear wall through friction, completing the "first-level tightening" and providing a stable foundation for leveling operations.

[0094] Factory prefabrication ensures that the quality of components is controllable, and the elastic snap-fit ​​preliminary positioning shortens the traditional temporary support positioning time, which takes 2-3 hours, to within 30 minutes, greatly improving construction efficiency.

[0095] S200. Use external force to rotate the leveling screw 13 to adjust the vertical heights of the first prefabricated composite shear wall 1 and the second prefabricated composite shear wall 2 to be consistent; and use external force to rotate the threaded connecting rod 18 to synchronously tighten the first connecting rod 16 and the second connecting rod 17 for horizontal tightening, and lock the self-locking nut 20 to fix the current leveling state.

[0096] The vertical relative heights of the first and second prefabricated composite shear walls are adjusted by rotating the leveling screw 13 with an external tool (such as a wrench) until their top surfaces are flush (flatness error ≤ 2 mm), and then the self-locking nut 20 is tightened to fix the current height and prevent vertical displacement.

[0097] When the threaded connecting rod is rotated, since the threads of the two connecting sections rotate in opposite directions, the first and second connecting rods are tightened toward the middle simultaneously, tightening the two prefabricated composite shear walls and eliminating the gap in the splicing surface; at the same time, the pawl ring 22 in the connecting hole 15 engages with the ratchet 11 of the corresponding threaded connecting rod 18 (rotation in opposite directions to adapt to two-way tightening), and cooperates with the pre-pressure of the elastic retainer 23 to achieve mechanical self-locking, preventing loosening due to vibration or load after leveling.

[0098] S300, pouring slurry into the gap between the plug rod 9 and the connecting groove 10 through the post-casting channel 19, and exhausting air through the exhaust hole 21 until the concrete hardens to form a UHPC prefabricated composite shear wall structure.

[0099] Among them, high-strength grouting materials compatible with UHPC are used, such as micro-expansion type with an expansion rate of 0.02%-0.05%, to ensure close bonding with the components after hardening.

[0100] The slurry is poured into the gap between the plug rod 9 and the connecting groove 10 and around the leveling unit through the post-casting channel 19. The slurry flows along the gap under the action of gravity and pressure, wrapping the threaded sleeve 12, connecting rod and other components of the leveling unit.

[0101] During the grouting process, the air in the gap is discharged through the exhaust hole 21 connected with the post-pouring channel and the connecting groove until the slurry overflows from the exhaust hole, indicating that all gaps have been completely filled (no air bubbles remaining), at which point the exhaust hole 21 is blocked to ensure that the grouting is dense.

[0102] After the slurry hardens, it is usually cured for more than 7 days, and forms an integral joint with the two prefabricated composite shear walls, the splicing rod 9, and the leveling unit. The grouting body connects the splicing rod 9 with the connecting groove 10, transmits shear force and tension, and the slurry wrapping the leveling unit makes the components and concrete co-force, avoiding the node becoming a weak area. The final UHPC prefabricated composite shear wall structure realizes "three-level fastening" through the dual action of mechanical fastening and material bonding, and the node shear strength is improved by more than 40%. Grouting solidification converts the dispersed prefabricated components into a continuous force system, and through the exhaust hole 21 ensures that there is no cavity, solving the pain points of traditional node mechanical connection easy to loosen and grouting not dense.

[0103] The construction method forms a progressive reinforcement mode from elastic clamping (first level), mechanical self-locking (second level), to grouting solidification (third level), three times of fastening, ensuring that the node does not loosen in long-term use, solving the problems of low assembly efficiency and poor node performance of traditional prefabricated shear walls, and providing a feasible technical path for the promotion of super-high-strength prefabricated buildings.

[0104] The above description is only the preferred embodiment of the present application and the explanation of the applied technical principles. Those skilled in the art should understand that the scope of the invention involved in the present application is not limited to the technical solutions formed by the specific combination of the above technical features, and should also cover other technical solutions formed by any combination of the above technical features or their equivalent features without departing from the inventive concept. For example, the above features are replaced with the technical features disclosed in the present application (but not limited to) having similar functions to form a technical solution.

Claims

1. A UHPC prefabricated composite shear wall structure, characterized in that: include: A plurality of shear wall units for use in combination, the shear wall units comprising a first prefabricated composite shear wall (1) and a second prefabricated composite shear wall (2) that are plug-connected, the first prefabricated composite shear wall (1) and the second prefabricated composite shear wall (2) each having a post-cast groove (8) at adjacent end positions; A leveling unit, the leveling unit being arranged between the first prefabricated composite shear wall (1) and the second prefabricated composite shear wall (2); the leveling unit comprising: two threaded sleeves (12) and a threaded connecting rod (18); the two threaded sleeves (12) being pre-buried in the two post-cast grooves (8) respectively, the threaded connecting rod (18) having a first connecting section and a second connecting section, the first connecting section and the second connecting section having opposite thread rotation directions, the first connecting section being threadedly connected to the first connecting rod (16), and the second connecting section being threadedly connected to the second connecting rod (17); the ends of the first connecting rod (16) and the second connecting rod (17) being away from each other are respectively provided with adjusting sleeves (14), the two adjusting sleeves (14) being respectively connected to the two threaded sleeves (12) via a leveling screw (13) and a self-locking nut (20); A post-casting channel (19), the post-casting channel (19) is opened on the side wall of the post-casting groove (8), and the post-casting channel (19) is connected to the plug-in connection position of the first prefabricated composite shear wall (1) and the second prefabricated composite shear wall (2); the post-casting channel (19) is used to transport grouting liquid to the plug-in connection position of the first prefabricated composite shear wall (1) and the second prefabricated composite shear wall (2) after the leveling unit leveled the first prefabricated composite shear wall (1) and the second prefabricated composite shear wall (2).

2. A UHPC prefabricated composite shear wall structure according to claim 1, characterized in that: The first prefabricated composite shear wall (1) and the second prefabricated composite shear wall (2) both comprise: A prefabricated base body, the prefabricated base body is a well-shaped structure, the prefabricated base body comprises a plurality of main ribs (6) arranged along a first direction and a plurality of secondary ribs (7) arranged along a second direction, the main ribs (6) and the secondary ribs (7) are connected by snapping at the intersection nodes, and an installation space is formed between adjacent main ribs (6) and secondary ribs (7); the first direction and the second direction are arranged perpendicularly; UHPC prefabricated blocks (3), the number of the UHPC prefabricated blocks (3) being equal to the number of the installation spaces; the UHPC prefabricated blocks (3) being assembled at the installation spaces; In-situ cast-in-situ anti-cracking concrete (4), the in-situ cast-in-situ anti-cracking concrete (4) is poured on the prefabricated base and the UHPC prefabricated block (3), and the post-cast groove (8) is formed at the end of the prefabricated composite shear wall.

3. A UHPC prefabricated composite shear wall structure according to claim 2, characterized in that: The components of the UHPC prefabricated block (3) include at least: a gelling system, a polymer emulsion, fibers, water, quartz sand, and a polyhydroxy acid water reducer; The water-to-cement ratio of the gelling system and the water is 0.17, and the mortar-to-sand ratio of the gelling system and the quartz sand is 1; The cementitious system comprises cement, metakaolin and silica fume; the mass ratio of cement, metakaolin and silica fume in the cementitious system is 7:1:2; The maximum particle size of the quartz sand is 5 mm, and the gradation thereof is 292 parts by weight of 4-8 mesh sand, 222 parts by weight of 8-10 mesh sand, 139 parts by weight of 10-30 mesh sand, 102 parts by weight of 30-50 mesh sand, 72 parts by weight of 50-100 mesh sand, and 173 parts by weight of 100-120 mesh sand; The amount of the polyhydroxy acid water reducer added is 2% of the total mass of the gelling system.

4. The UHPC prefabricated composite shear wall structure according to claim 3, characterized in that: The polymer emulsion is an acrylic emulsion; the amount of the acrylic emulsion added is 4% of the total mass of the gelling system; the fiber is a copolymerized oxymethylene fiber, and the amount of the copolymerized oxymethylene fiber added is 2% of the total volume of the UHPC prefabricated block (3).

5. The UHPC prefabricated composite shear wall structure according to claim 4, characterized in that: The method for preparing the UHPC prefabricated block (3) comprises the following steps: 700 parts of cement, 100 parts of metakaolin, and 200 parts of silica fume were added to a mixer in order according to weight parts, and then quartz sand graded to, by weight, 292 parts of 4-8 mesh sand, 222 parts of 8-10 mesh sand, 139 parts of 10-30 mesh sand, 102 parts of 30-50 mesh sand, 72 parts of 50-100 mesh sand, and 173 parts of 100-120 mesh sand was added to the mixer, and dry mixed at a first preset speed for 3 minutes to obtain a mixed dry material; Under the stirring state at a first preset speed, 170 parts of water, 40 parts of acrylic emulsion, and 20 parts of polyhydroxy acid water reducer are added to the mixer according to weight parts until they are stirred into a plastic state, and then 2% of the total volume of the UHPC prefabricated block (3) is added to the mixer, and stirred at a second preset speed for 5 minutes, and then stirred at the first preset speed for 3 minutes to obtain a slurry; the first preset speed is less than the second preset speed; The slurry obtained after stirring is introduced into the test mold, and the mortar vibrating table is controlled to vibrate for a preset number of times to obtain a molded test block; The molded test block is placed in a standard curing box for curing to obtain the UHPC prefabricated block (3).

6. The UHPC prefabricated composite shear wall structure according to claim 1, characterized in that: Adjacent end surfaces of the first prefabricated composite shear wall (1) and the second prefabricated composite shear wall (2) form a splicing surface; The splicing surface of the first prefabricated composite shear wall (1) is provided with at least two plug-in rods (9), and the splicing surface of the second prefabricated composite shear wall (2) is provided with connecting grooves (10) matching the plug-in rods (9); or, the splicing surface of the second prefabricated composite shear wall (2) is provided with at least two plug-in rods (9), and the splicing surface of the first prefabricated composite shear wall (1) is provided with connecting grooves (10) matching the plug-in rods (9).

7. The UHPC prefabricated composite shear wall structure according to claim 6, characterized in that: The side wall of the plug rod (9) is provided with a slide groove opened along its axial direction, the bottom of the slide groove is hingedly connected to one side of the wedge-shaped connecting piece (24), and an elastic element (5) is further provided between the slide groove and the surface of the wedge-shaped connecting piece (24); When the plug-in rod (9) is inserted into the connecting groove (10), the wedge-shaped connecting piece (24) rotates relative to the sliding groove and abuts against the connecting groove (10).

8. The UHPC prefabricated composite shear wall structure according to claim 6, characterized in that: Also includes: An exhaust hole (21), the exhaust hole (21) is opened on the prefabricated composite shear wall having the post-casting channel (19); the exhaust hole (21) is connected to the post-casting channel (19) and the connecting groove (10).

9. The UHPC prefabricated composite shear wall structure according to claim 1, characterized in that: The first connecting rod (16) and the second connecting rod (17) both have a connecting hole (15) threadedly connected to the threaded connecting rod (18); the inner wall of the connecting hole (15) is connected to the pawl ring (22) via an elastic retaining frame (23); The first connecting section and the second connecting section are both provided with ratchet teeth (11) matching the corresponding ratchet rings (22), and the rotation directions of the ratchet teeth (11) of the first connecting section and the ratchet teeth (11) of the second connecting section are opposite.

10. A construction method for a UHPC prefabricated composite shear wall structure, characterized in that: The following steps are involved: Prepare UHPC prefabricated blocks (3) and prefabricated shear wall units, hoist the first prefabricated composite shear wall (1) and the second prefabricated composite shear wall (2), insert the connecting rods (9) into the corresponding connecting grooves (10), and perform preliminary positioning by elastically engaging the wedge-shaped connecting pieces (24); The leveling screw (13) is rotated by applying an external force to adjust the vertical heights of the first prefabricated composite shear wall (1) and the second prefabricated composite shear wall (2) to be consistent; and the threaded connecting rod (18) is rotated by applying an external force to synchronously tighten the first connecting rod (16) and the second connecting rod (17) to tighten them in the horizontal direction, and the self-locking nut (20) is locked to fix the current leveling state; Grout is poured into the gap between the plug-in rod (9) and the connection groove (10) through the post-casting channel (19), and air is exhausted through the exhaust hole (21) until the concrete hardens to form a UHPC prefabricated composite shear wall structure.

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