Connecting joint adopting UHPFRC (Ultra High Performance Fiber Reinforced Concrete) lap joint for vertical steel bars of prefabricated wall panel

Abstract

The invention discloses a connecting joint for vertical steel bars of a prefabricated panel by adopting UHPFRC (Ultra High Performance Fiber Reinforced Concrete) lap joint, and belongs to the technical field of building structures. The connecting joint comprises a first prefabricated wall panel and a second prefabricated wall panel, wherein the first prefabricated wall panel comprises a connecting hole and a first connecting steel bar; the second prefabricated wallboard comprises second connecting steel bars, the first connecting steel bars and the second connecting steel bars are arranged in the connecting holes at intervals, and UHPFRC is poured into the connecting holes. The connecting holes are formed in the horizontal joints of the bottoms or the tops of the prefabricated wall panels, the connecting steel bars are arranged in the connecting holes, the connecting steel bars extending out of the prefabricated wall bodies adjacent to the horizontal joints are in single-row or double-row lap joint in the connecting holes by pouring the UHPFRC, and therefore formworks and sleeves / casing pipes are omitted, and the construction cost is reduced. The construction technology of vertical steel bar connection in the fabricated shear wall is obviously simplified, and the connection cost is reduced.

Description

Technical Field

[0001] The invention belongs to the technical field of building structures, and in particular relates to a connection node in which vertical reinforcements of a prefabricated wall panel are overlapped by UHPFRC. Background Art

[0002] With the continuous advancement of building industrialization and modular construction technology, prefabricated shear wall structures have gradually become one of the main structural forms of high-rise buildings and large public buildings. Prefabricated shear walls not only significantly shorten the construction period through standardized production of prefabricated components and rapid on-site assembly, but also improve the consistency and controllability of construction quality. In addition, prefabricated shear wall structures have excellent seismic performance and good structural stability, can effectively resist horizontal and vertical loads, and meet the high requirements of modern buildings for safety and durability. Therefore, the application of prefabricated shear walls in high-rise buildings is becoming more and more widespread, becoming an important development direction of the construction industry.

[0003] In prefabricated shear wall structures, the connection nodes of vertical steel bars are the key parts to ensure the overall performance of the shear wall. At present, the main connection methods used include grout-anchor lap connection, mechanical connectors and grouting sleeve connection. These methods have their own advantages and disadvantages, but they generally have problems such as high construction complexity and difficulty in cost control. For example, the grout-anchor lap connection relies on the bond force of concrete to transfer loads, and its scope of application is limited. It can only be used for the connection of smaller diameter steel bars, and the connection length is too long. Although mechanical connectors are reliable, they are expensive and the construction process is complicated. In addition, mechanical connection nodes require on-site formwork, which is generally used for cast-in-place structures and is rarely used in precast concrete shear wall structures. Although the grouting sleeve connection can avoid the formwork process, it has strict requirements on construction technology and quality control, and the cost is high due to the large amount of sleeves used.

[0004] Ultra-high performance fiber-reinforced concrete (UHPFRC) has become a hot topic in building materials research in recent years due to its excellent mechanical properties and durability. UHPFRC has high strength, high toughness, low permeability and excellent durability. It can significantly reduce the lap length of steel bars, improve the stress performance and ductility of the connection area, and enhance the overall stability and seismic resistance of the structure. The current application of UHPFRC in steel bar connections still faces problems such as complex structural design, high construction process requirements, and high costs. The existing technology is not yet mature in the structural design, construction method standardization and cost control of UHPFRC connection nodes. Further research and optimization are urgently needed to give full play to the application potential of UHPFRC in the node connection of prefabricated concrete shear wall structures. Summary of the invention

[0005] The object of the present invention is to provide a connection node in which vertical reinforcements of a prefabricated wall panel are overlapped by UHPFRC, wherein a connection hole is provided at a horizontal joint at the bottom or top of the prefabricated wall panel, and connecting reinforcements are arranged in the connection hole. Connecting reinforcements extending from a prefabricated wall body adjacent to the horizontal joint are overlapped and connected by pouring UHPFRC in the connection hole, thereby eliminating the need for formwork and sleeves / tubes, significantly simplifying the construction process of vertical reinforcement connection in an assembled shear wall, and reducing the connection cost, thereby solving at least one technical problem involved in the background technology.

[0006] In order to solve the above-mentioned technical problems, the present invention is achieved as follows: The present invention provides a connection node in which vertical reinforcements of a prefabricated wall panel are overlapped by UHPFRC, comprising a first prefabricated wall panel and a second prefabricated wall panel connected to the first prefabricated wall panel in a vertical direction, wherein the first prefabricated wall panel comprises a connection hole formed by a depression from a top surface or a bottom surface thereof and a first connection reinforcement whose one end is anchored in the first prefabricated wall panel and whose other end extends into the connection hole; the second prefabricated wall panel comprises a second connection reinforcement whose one end is anchored in the second prefabricated wall panel and whose other end extends into the connection hole, wherein the first connection reinforcement and the second connection reinforcement are located in the connection hole. The connecting holes are filled with UHPFRC for overlapping the first connecting steel bars and the second connecting steel bars; the first connecting steel bars and the second connecting steel bars are arranged in pairs in the connecting holes; when a single-row overlapping connection is adopted, one first connecting steel bar and one second connecting steel bar are centrally arranged in the connecting hole along the axis direction of the prefabricated wall panel; when a double-row overlapping connection is adopted, two first connecting steel bars with the same diameter and two second connecting steel bars with the same diameter are arranged in pairs at 1 / 4 and 3 / 4 of the width of the connecting hole along the axis direction of the prefabricated wall panel.

[0007] Optionally, the first connecting steel bar extends vertically from the bottom of the connecting hole to the inside of the connecting hole.

[0008] Optionally, the first connecting steel bars and the second connecting steel bars are arranged in parallel and at intervals.

[0009] Optionally, the diameter and strength of the first connecting steel bar are equal to those of the second connecting steel bar, and the spacing distance between the two is 1 times the diameter of the first connecting steel bar.

[0010] Optionally, the first connecting steel bars and the second connecting steel bars are both ribbed steel bars.

[0011] Optionally, the connecting hole is a rectangular hole. When a single-row lap connection is adopted, the hole length is not less than 7 times the diameter of the first connecting steel bar, the hole depth is not less than the lap length of the first connecting steel bar and the second connecting steel bar, and the hole width is not less than 3.5 times the diameter of the first connecting steel bar; when a double-row connection is adopted, the hole length is not less than 7 times the diameter of the first connecting steel bar, the hole depth is not less than the lap length of the first connecting steel bar and the second connecting steel bar, and the hole width is not less than 7 times the diameter of the first connecting steel bar.

[0012] Optionally, the lap connection length of the first connecting steel bar and the second connecting steel bar is not less than 15 times the diameter of the first connecting steel bar; when the connection node is constrained by a closed stirrup with a diameter of not less than 6 mm and a spacing of not more than 50 mm, the lap connection length of the first connecting steel bar and the second connecting steel bar is not less than 10 times the diameter of the first connecting steel bar. When the types of the first connecting steel bar and the second connecting steel bar are HRB 500 and HRB 600, the lap length increases by 25% and 50% respectively.

[0013] Optionally, the UHPFRC is poured into the connection hole in a pressure-free manner from a pre-buried grouting pipe connected to the connection hole. The axial compressive strength of the UHPFRC is not less than 100 MPa, the axial tensile strength is not less than 7 MPa, and the fiber volume ratio is not less than 1%.

[0014] Optionally, the sum of the cross-sectional areas of the first connecting steel bars is not less than the sum of the cross-sectional areas of the vertically connected steel bars in the first prefabricated wall panel, and the sum of the cross-sectional areas of the second connecting steel bars is not less than the sum of the cross-sectional areas of the vertically connected steel bars in the second prefabricated wall panel.

[0015] Compared with the prior art, the present invention has the following beneficial effects: 1. The present invention provides a connection hole at the bottom or top horizontal joint of the prefabricated wall panel, and arranges connecting steel bars in the connection hole. The connecting steel bars extending from the prefabricated wall adjacent to the horizontal joint are overlapped and connected in a single row or double row in the connection hole, thereby eliminating the need for formwork and sleeves / tubes, significantly simplifying the construction process of vertical steel bar connection in the assembled shear wall, and reducing the connection cost.

[0016] 2. The present invention adopts ultra-high performance fiber reinforced concrete (UHPFRC) as the connection material, and realizes the lap connection of the steel bars by pouring UHPFRC in the connection hole; the high strength, high toughness and excellent grip performance of UHPFRC make the connection node have a stronger force-bearing capacity, and significantly reduce the lap length compared with the traditional slurry anchor lap connection method; in addition, only using UHPFRC in the connection hole significantly reduces the amount of this high-performance material, so that the material cost is effectively controlled.

[0017] 3. The connecting steel bars in the connecting holes of the present invention are connected by non-contact lap joints, and the net distance between the steel bars is preferably 0 to 2 times the diameter of the connecting steel bars; compared with the traditional grouting sleeve connection method, which has high requirements for the hole accuracy of the connecting steel bars, which often makes it difficult to install the prefabricated shear wall, the connection method provided by the present invention allows the connecting steel bars to complete indirect lap joints within a relatively large installation error range, and the hole size of the connecting hole is much larger than the hole size of the sleeve / casing, which significantly reduces the hole accuracy requirements when the prefabricated shear wall is installed, and improves the construction and installation efficiency.

[0018] 4. The opening size of the connection hole used in the present invention is much larger than the opening size of the traditional grout anchor lap joint and sleeve grouting connection method. UHPFRC does not need to use pressure grouting when grouting. The large-diameter pre-buried grouting pipe connected to the connection hole adopts pressure-free (gravity) grouting, which is not only convenient and simple to construct, but also avoids the problems that may occur in sleeve / casing grouting, such as sleeve blockage, incomplete slurry, and difficulty in detecting grouting quality.

[0019] 5. The present invention can appropriately reduce the width and depth of the connection hole (or the lap length of the connection steel bars) by evenly distributing closed stirrups within the height range of the connection hole at the end of the prefabricated wall panel while ensuring that the tensile strength of the connection steel bars is fully utilized; the closed stirrups are preferably welded and can be arranged at the outer or inner edge of the connection hole.

[0020] 6. The present invention improves the seismic performance of the connection nodes to a certain extent by optimizing the lap connection design and using UHPFRC materials. Since the compressive strength and ductility of UHPRFC are better than those of ordinary concrete, the use of UHPFRC at the connection nodes can delay the crushing of the bottom concrete of the wall edge components and enhance the ductility and seismic performance of the wall and structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for describing the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative work, among which: Figure 1 A structural diagram of a connection node in which vertical reinforcements of a prefabricated wall panel provided by the present invention are overlapped by UHPFRC; Figure 2 A schematic diagram of the assembly structure of the connecting steel bar provided by the present invention in the connecting hole; Figure 3 The overall structural diagram of the connection node of the vertical reinforcement of the prefabricated wall panel provided by the present invention is overlapped by UHPFRC.

[0022] Reference numerals: 1: first prefabricated wall panel; 11: connection hole; 12: first connection steel bar; 13: closed stirrup; 14: vertical connected steel bar; 15: horizontal distribution steel bar; 2: second prefabricated wall panel; 21: second connecting steel bar; 3: floor slab; 31: mortar layer; 4:UHPRFC. DETAILED DESCRIPTION

[0023] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0024] See also Figures 1 to 3 As shown, the present invention provides a connection node in which vertical reinforcements of prefabricated wall panels are overlapped by UHPFRC, comprising a first prefabricated wall panel 1 and a second prefabricated wall panel 2 vertically connected to the first prefabricated wall panel 1. In the present embodiment, the connection node also includes a floor slab 3 horizontally arranged between the first prefabricated wall panel 1 and the second prefabricated wall panel 2, and a mortar layer 31 is also provided at the connection between the floor slab 3 and the first prefabricated wall body 1.

[0025] The first prefabricated wall panel 1 includes a connection hole 11 recessed from the top surface or the bottom surface thereof and a first connection steel bar 12 with one end anchored in the first prefabricated wall panel 1 and the other end extending into the connection hole 11 .

[0026] The first connecting steel bar 12 vertically extends from the bottom of the connecting hole 11 to the inside of the connecting hole 11 .

[0027] Specifically, when the first prefabricated wall panel 1 is located above the second prefabricated wall panel 2, the connection hole 11 is formed by being recessed from the bottom surface of the first prefabricated wall panel 1. When the first prefabricated wall panel 1 is located below the second prefabricated wall panel 2, the connection hole 11 is formed by being recessed from the top surface of the first prefabricated wall panel 1.

[0028] The second prefabricated wall panel 2 includes a second connecting steel bar 21 with one end anchored in the second prefabricated wall panel 2 and the other end extending into the connecting hole 11, and the first connecting steel bar 12 and the second connecting steel bar 21 are arranged at intervals in the portion in the connecting hole 11. In this way, by arranging the connecting hole 11 at the bottom or top horizontal joint of the first prefabricated wall panel 1, and arranging the first connecting steel bar 12 in the connecting hole 11 and lap-connecting the second connecting steel bar 21 extending from the second prefabricated wall body 2 adjacent to the horizontal joint in the connecting hole 11, the template and the sleeve / tube are eliminated, which significantly simplifies the construction process of vertical steel bar connection in the assembled shear wall and reduces the connection cost.

[0029] In a specific embodiment, the diameter and strength of the first connecting steel bar 12 and the second connecting steel bar 21 are equal, and the spacing distance between them is 1 times the diameter of the first connecting steel bar 12 .

[0030] The connecting steel bars in the connecting hole 11 are connected by non-contact lap connection, and the net distance between the connecting steel bars is controlled within the range of 0 to 2 times the diameter of the connecting steel bars, that is, the allowable construction deviation is about 1 times the diameter of the first connecting steel bar 12; compared with the traditional grouting sleeve connection method, which has high requirements on the steel bar hole accuracy, which often makes it difficult to install the prefabricated shear wall, the connection method provided by the present invention allows the connecting steel bars to complete indirect lap within a relatively large installation error range, and the orifice size of the connecting hole is much larger than the orifice size of the sleeve / casing, which significantly reduces the hole accuracy requirements when the prefabricated shear wall is installed, and improves the construction and installation efficiency.

[0031] The connection hole 11 is filled with UHPFRC 4 for fixing the first connection steel bar 12 and the second connection steel bar 21. By pouring UHPFRC4 as a connection material in the connection hole 11 to achieve the overlap connection of the steel bars, the high strength, high toughness and excellent grip performance of UHPFRC4 can be used to make the connection node have a stronger force bearing capacity, and the overlap length is significantly reduced compared with the traditional grout anchor overlap connection method; in addition, only using UHPFRC4 in the connection hole 11 significantly reduces the amount of this high-performance material, so that the material cost is effectively controlled.

[0032] The UHPFRC 4 is poured into the connection hole 11 in a pressure-free manner from a large-diameter pre-buried grouting pipe connected to the connection hole 11. The axial compressive strength of the UHPFRC 4 is not less than 100MPa, the axial tensile strength is not less than 7MPa, and the fiber volume rate is not less than 1%. In this way, not only is the construction convenient and simple, but also the problems of sleeve blockage, incomplete slurry, and difficulty in detecting grouting quality that may occur in sleeve / casing grouting are avoided.

[0033] The present invention improves the seismic performance of the connection nodes to a certain extent by optimizing the lap joint design and using UHPFRC materials. Since the compressive strength and ductility of UHPRFC are better than those of ordinary concrete, the use of UHPFRC at the connection nodes can delay the crushing of the concrete at the bottom of the wall edge components and enhance the ductility and seismic performance of the wall and structure.

[0034] See Figure 2 As shown, the first connecting steel bar 12 and the second connecting steel bar 21 are arranged in pairs in the connecting hole 11. When a single-row indirect lap joint is adopted, one first connecting steel bar 12 and one second connecting steel bar 21 are centrally arranged in the connecting hole 11 along the axial direction of the prefabricated wall panel, so as to form a vertical continuous force transmission path; when a double-row lap joint is adopted, two first connecting steel bars 12 with the same diameter and two second connecting steel bars 21 with the same diameter are arranged in pairs at 1 / 4 and 3 / 4 of the width of the connecting hole along the axial direction of the prefabricated wall panel.

[0035] Of course, in other embodiments, the connection nodes may be extended along the axial direction of the wall panel, and multiple connection nodes may be combined into a whole, and multiple pairs of connection steel bars may be provided in the combined connection holes along the length direction.

[0036] The first connecting steel bar 12 and the second connecting steel bar 21 are ribbed steel bars with the same diameter. The connecting hole 11 is a rectangular hole. When a single-row lap connection is adopted, the hole length is not less than 7 times the diameter of the first connecting steel bar 12, the hole depth is not less than the lap length of the first connecting steel bar 12 and the second connecting steel bar 21, and the hole width is not less than 3.5 times the diameter of the first connecting steel bar 12; when a double-row connection is adopted, the hole length is not less than 7 times the diameter of the first connecting steel bar 12, the hole depth is not less than the lap length of the first connecting steel bar 12 and the second connecting steel bar 21, the hole width is not less than 7 times the diameter of the first connecting steel bar 12, and the minimum hole depth is the lap length of the first connecting steel bar 12 and the second connecting steel bar 21. The width of the connecting hole 11 should be able to ensure that the UHPFRC does not suffer from splitting damage before the tensile strength of the connecting steel bar is fully utilized, and should not be greater than the thickness of the first prefabricated wall panel 1 minus the thickness of the protective layer on both sides and the diameter of the horizontally distributed steel bars on both sides. Since the opening size of the connection hole 11 is much larger than the cross-sectional size of the connection steel bar, the hole accuracy requirement during the hoisting of the prefabricated wall panel is reduced, and the problem of difficult hole installation in the traditional grouting sleeve connection method is solved. In addition, the setting of the connection hole eliminates the formwork process, simplifies the construction process and improves the level of construction industrialization.

[0037] It should be additionally explained that the first prefabricated wall panel 1 and the second prefabricated wall panel 2 are further provided with vertically connected steel bars 14 and transversely arranged horizontal distribution steel bars 15 .

[0038] The sum of the cross-sectional areas of the first connecting steel bars 12 is not less than the sum of the cross-sectional areas of the vertically connected steel bars 14 in the first prefabricated wall panel 1 , and the sum of the cross-sectional areas of the second connecting steel bars 21 is not less than the sum of the cross-sectional areas of the vertically connected steel bars 14 in the second prefabricated wall panel 2 .

[0039] Furthermore, UHPFRC not only has high tensile strength, but also can achieve tensile strain hardening due to the addition of steel fibers, thereby improving the toughness and ductility of the material. Compared with the traditional grout-anchor lap connection method, the lap connection method of UHPFRC used in the present invention significantly reduces the lap length of the connecting steel bars (reduced by about 75%). The shortening of the lap length can, firstly, make the horizontal anchor ring spacing of adjacent prefabricated wall panels at the vertical joints meet the hoisting requirements of the wall panels, that is, the vertical connecting steel bar lap length is less than the horizontal anchor ring spacing; secondly, it can shorten the grouting length, thereby improving the grouting quality and saving the amount of UHPFRC. Traditional pressure grouting cannot use steel fibers to enhance the grouting material, but the present invention uses a connection hole size that is much larger than the cross-section of the connecting steel bar, so that UHPFRC can be poured in a pressure-free manner. This simplifies the grouting construction process and improves the tensile performance of the grouting material and its ability to hold the steel bars, effectively reducing the lap length of the connecting steel bars.

[0040] When closed stirrups 13 are provided around the connection hole 11 in the first prefabricated wall panel 1, it helps to prevent splitting damage at the connection node. Under the premise of ensuring that the tensile strength of the connecting steel bars is fully utilized, the width and depth of the connection hole (or the lap length of the connecting steel bars) can be appropriately reduced.

[0041] The minimum lap length of the first connecting steel bar 12 and the second connecting steel bar 21 is 15 times the diameter of the first connecting steel bar 12; when the connection node is constrained by a closed stirrup 13 with a diameter of not less than 6 mm and a spacing of not more than 50 mm, the lap connection length of the first connecting steel bar 12 and the second connecting steel bar 21 is not less than 10 times the diameter of the first connecting steel bar 12. When the types of the first connecting steel bar 12 and the second connecting steel bar 21 are HRB 500 and HRB 600, the lap length increases by 25% and 50% respectively.

[0042] It should be noted that, in this article, the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, an element defined by the sentence "comprises a ..." does not exclude the existence of other identical elements in the process, method, article or device including the element.

[0043] In addition, it should be noted that the scope of the methods and systems in the embodiments of the present invention is not limited to performing functions in the order shown or discussed, and may also include performing functions in a substantially simultaneous manner or in reverse order according to the functions involved. For example, the described methods may be performed in an order different from that described, and various steps may be added, omitted, or combined. In addition, features described with reference to certain examples may be combined in other examples.

[0044] The embodiments of the present invention are described above, but the present invention is not limited to the above-mentioned specific implementation modes. The above-mentioned specific implementation modes are merely illustrative and not restrictive. Under the guidance of the present invention, ordinary technicians in this field can also make many forms without departing from the scope of protection of the purpose of the present invention and the claims, all of which are protected by the present invention.

Claims

1. A connection node in which vertical reinforcements of a prefabricated wall panel are overlapped by UHPFRC, characterized in that: The invention comprises a first prefabricated wall panel and a second prefabricated wall panel connected to the first prefabricated wall panel in a vertical direction, wherein the first prefabricated wall panel comprises a connection hole formed by a depression from a top surface or a bottom surface thereof and a first connection steel bar having one end anchored in the first prefabricated wall panel and the other end extending into the connection hole; the second prefabricated wall panel comprises a second connection steel bar having one end anchored in the second prefabricated wall panel and the other end extending into the connection hole, wherein the first connection steel bar and the second connection steel bar are arranged at intervals in the parts located in the connection hole, and the connection hole is poured with UHPFRC for overlapping the first connection steel bar and the second connection steel bar; the first connection steel bar and the second connection steel bar are arranged in pairs in the connection hole; when a single-row overlap connection is adopted, one first connection steel bar and one second connection steel bar are arranged in the center of the connection hole along the axis direction of the prefabricated wall panel; when a double-row overlap connection is adopted, two first connection steel bars with the same diameter and two second connection steel bars with the same diameter are arranged in pairs at 1 / 4 and 3 / 4 of the width of the connection hole along the axis direction of the prefabricated wall panel.

2. A connection node for overlapping vertical reinforcements of a prefabricated wall panel using UHPFRC according to claim 1, characterized in that: The first connecting steel bar vertically extends from the bottom of the connecting hole to the inside of the connecting hole.

3. The connection node of the prefabricated wall panel vertical reinforcement using UHPFRC overlap according to claim 2, characterized in that: The first connecting steel bars are arranged in parallel and spaced apart from the second connecting steel bars.

4. The connection node of the prefabricated wall panel vertical reinforcement using UHPFRC overlap according to claim 3, characterized in that: The diameter and strength of the first connecting steel bar are equal to those of the second connecting steel bar, and the spacing distance between the two is 1 times the diameter of the first connecting steel bar.

5. A connection node for overlapping vertical reinforcements of a prefabricated wall panel using UHPFRC according to claim 4, characterized in that: The first connecting steel bar and the second connecting steel bar are both ribbed steel bars.

6. The connection node of the prefabricated wall panel vertical reinforcement using UHPFRC overlap according to claim 1, characterized in that: The connecting hole is a rectangular hole. When a single-row lap connection is adopted, the hole length is not less than 7 times the diameter of the first connecting steel bar, the hole depth is not less than the lap length of the first connecting steel bar and the second connecting steel bar, and the hole width is not less than 3.5 times the diameter of the first connecting steel bar; when a double-row connection is adopted, the hole length is not less than 7 times the diameter of the first connecting steel bar, the hole depth is not less than the lap length of the first connecting steel bar and the second connecting steel bar, and the hole width is not less than 7 times the diameter of the first connecting steel bar.

7. A connection node for overlapping vertical reinforcements of a prefabricated wall panel using UHPFRC according to claim 6, characterized in that: The lap connection length of the first connecting steel bar and the second connecting steel bar shall not be less than 15 times the diameter of the first connecting steel bar; when the connection node is constrained by closed stirrups with a diameter of not less than 6 mm and a spacing of not more than 50 mm, the lap connection length of the first connecting steel bar and the second connecting steel bar shall not be less than 10 times the diameter of the first connecting steel bar.

8. The connection node of the prefabricated wall panel vertical reinforcement using UHPFRC overlap according to claim 1, characterized in that: The UHPFRC is poured into the connection hole in a pressure-free manner from a pre-buried grouting pipe connected to the connection hole.

9. The connection node of the prefabricated wall panel vertical reinforcement using UHPFRC overlap according to claim 1, characterized in that: The sum of the cross-sectional areas of the first connecting steel bars is not less than the sum of the cross-sectional areas of the vertically connected steel bars in the first prefabricated wall panel, and the sum of the cross-sectional areas of the second connecting steel bars is not less than the sum of the cross-sectional areas of the vertically connected steel bars in the second prefabricated wall panel.

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