Pre-constrained block beam and connecting system thereof

Abstract

The utility model discloses a pre-constrained block beam and a connecting system thereof. The pre-constrained block beam comprises a block, a constraint cage, a polymer and a beam steel bar, the constraint cage comprises a cage frame and constraint cage holes; the block material is arranged in the constraint cage to form a pre-constraint block material; the beam reinforcing steel bars comprise beam longitudinal reinforcing steel bars and beam transverse reinforcing steel bars; the beam transverse reinforcements are arranged at intervals along the beam longitudinal reinforcements to form a beam reinforcement cage; the constraint cage is surrounded by the beam reinforcement cage; the polymer fills the gaps in the pre-confinement block; the polymer wraps the beam reinforcement cage and fills a gap between the pre-constraint block and the beam reinforcement cage; and polymers are arranged at the holes of the restraint cage, so that the polymers in the restraint cage and the polymers outside the restraint cage are connected into a whole. According to the utility model, the block and the polymer are arranged in the constraint cage to form a pre-constraint block polymer, so that excessive crushing of the block is reduced, and energy consumption and pollution are reduced; the combined action of the block and the polymer is enhanced, and the bearing capacity and ductility of the pre-restrained block beam are improved.

Description

Technical Field

[0001] The utility model belongs to the field of structures, and particularly relates to a pre-constrained block beam and a connection system thereof. Background Art

[0002] In construction projects, structural beams are an important part of building structures and bridges. Structural beams often use reinforced concrete beams, which are composed of concrete and steel bars. This requires a large amount of stone, sand, and cement materials. According to statistics, the amount of stone used in construction in my country accounts for nearly 1 / 2 of the mass of concrete, and its use is widespread in many industries such as construction, transportation, and railways. According to estimates, the annual amount of stone used in construction in the country is about more than 4 billion tons, which is the material that consumes the most natural resources. At present, the natural sand and gravel that meet the requirements of reinforced concrete structures can no longer meet the needs of engineering. In actual engineering, a large amount of machine-made sand and machine-made stone are used. Usually, natural stones are processed by vibrating feeders, jaw crushers, sand making machines, vibrating screens, and belt conveyors. Equipment such as conveyors are used to crush natural stones into small-sized gravel or sand. This process requires high consumption of electricity, transportation, and labor, and produces a lot of dust. This puts great pressure on our resources and environment. How to reduce the use of cement, small-sized sand, and stone in structural beams is of great significance to my country's engineering construction and energy conservation and environmental protection. Utility Model Content

[0003] The purpose of the utility model is to provide a pre-constrained block beam and its connection system, which solves the problem of excessive cement, small-size sand and stone in the structural beam, and solves the problem of coordinated force between the block, steel bar and polymer. The utility model effectively reduces the amount of cement, small-size sand and stone, reduces hydration heat and dust by pre-constraining blocks built into the structural beam; improves the connection and force between the block and the polymer by the constraint cage, and realizes the mechanical properties of the beam. This technology has the advantages of reliable performance, simple structure, fast construction and green environmental protection.

[0004] To achieve the above purpose, the utility model adopts the following technical solutions.

[0005] A pre-constrained block beam comprises a block, a constraint cage, a polymer and beam reinforcement; the constraint cage comprises a cage frame and constraint cage holes; the block is built into the constraint cage to form a pre-constrained block; the constraint cage is closed at the ends; the constraint cage is a constraint reinforcement cage or a grid cage; the beam reinforcement comprises a beam longitudinal reinforcement and a beam transverse reinforcement; the beam transverse reinforcement is arranged at intervals along the beam longitudinal reinforcement to form a beam reinforcement cage; the constraint cage is surrounded by the beam reinforcement cage; the polymer fills the gap in the pre-constrained block; the polymer wraps the beam reinforcement cage and fills the gap between the pre-constrained block and the beam reinforcement cage; the polymer is present at the constraint cage holes to connect the polymer in the constraint cage and the polymer outside the constraint cage into one.

[0006] Preferably, the size of the restraining cage hole is smaller than the size of the block there; the cage frame includes a side wall frame and an end closure; the end closure is formed by extending the side wall frame or is a dedicated end closure; the pre-restrained block is located in the middle area of ​​the beam section height.

[0007] Preferably, the cage frame of the restraining rib cage is composed of restraining ribs; the restraining ribs are steel bars or steel wires or FRP bars; and the cage frame of the grid cage is composed of metal mesh or steel plates with holes.

[0008] Preferably, the restraining ribs include longitudinal ribs, transverse ribs and / or diagonal ribs; the end closures of the restraining rib cage are formed by fixing or bending the longitudinal ribs or diagonal ribs at the ends or are independent end closures; the independent end closures are fixedly connected to the longitudinal ribs or diagonal ribs.

[0009] Preferably, the cage has a plurality of sub-spaces; the sub-spaces are independent of each other and contain blocks of materials.

[0010] Preferably, a steel frame is provided inside the beam reinforcement cage; the steel frame is a steel section or a steel member; there is a gap between the steel frame and the pre-constrained block material and the beam reinforcement cage; and the polymer fills the gap between the pre-constrained block material, the steel frame and the beam reinforcement cage.

[0011] Preferably, the transverse reinforcement of the beam includes closed stirrups, transverse tension bars and rear closed stirrups; the rear closed stirrups are composed of open U-shaped stirrups and rear closed bars; the rear closed bars include rear closed tension bars or rear closed U-shaped stirrups; the rear closed bars are arranged correspondingly to the open U-shaped stirrups.

[0012] Preferably, a connection system for pre-constrained block beams includes pre-constrained block beams and reinforced concrete columns, wherein the pre-constrained block beams are fixedly connected to the reinforced concrete columns to form a beam-column node area; the longitudinal reinforcement of the beams extends into the reinforced concrete columns, is located in the gap between the transverse reinforcement of the columns and the longitudinal reinforcement of the columns, and is wrapped by the column concrete; there are no pre-constrained blocks in the beam-column node area.

[0013] Compared with the prior art, the utility model has the following characteristics and beneficial effects.

[0014] 1. The contact mode and contact area of ​​the blocks during construction are effectively controlled by the restraint cage, so that the polymer can effectively fill the gaps between the blocks, effectively reduce quality defects, improve construction quality, and achieve structural safety.

[0015] 2. By placing blocks inside the beam, the amount of cement, sand and stone used can be reduced, the hydration heat of large beams can be reduced during construction, and energy conservation and emission reduction can be achieved.

[0016] 3. The block materials and polymers in the beam are constrained by the constraint cage inside the beam to form constrained block material polymers, thereby improving the strength and ductility of the combination of block materials and polymers and achieving the mechanical properties of pre-constrained block material beams.

[0017] 4. Pre-constrained blocks can be pre-processed in whole or in part, with high construction efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The utility model is further described in detail below in conjunction with the accompanying drawings.

[0019] Figure 1 It is a schematic diagram of the transverse section of the pre-constrained block beam.

[0020] Figure 2 It is a schematic diagram of the longitudinal section of the pre-constrained block beam.

[0021] Figure 3 It is a schematic longitudinal cross-sectional view of the pre-constrained block 9.

[0022] Figure 4 Schematic diagram of a pre-constrained block 9 with a spacer 7 Figure 1 .

[0023] Figure 5 Schematic diagram of a pre-constrained block 9 with a spacer 7 Figure 2 .

[0024] Figure 6 It is a schematic cross-sectional view of a pre-constrained block beam having a plurality of pre-constrained blocks 9 and positioning members 8.

[0025] Figure 7 It is a schematic longitudinal section diagram of a pre-constrained block beam having a plurality of pre-constrained blocks 9 and positioning members 8.

[0026] Figure 8 It is a schematic diagram of the transverse section of a pre-constrained block beam with steel frame.

[0027] Fig. 9 It is a schematic diagram of the transverse section of a pre-restrained block beam with rear closed stirrups.

[0028] Fig.10 It is a schematic diagram of the longitudinal section of the pre-constrained block beam and column connection system.

[0029] Figure numerals: 1-block, 2-restraint cage, 2.1-cage frame, 2.1.1-side wall frame, 2.1.2-end closure, 2.2-restraint cage hole, 3-polymer, 4-restraint bar, 4.1-longitudinal bar, 4.2-transverse bar, 4.3-diagonal bar, 5-beam reinforcement, 5.1-beam longitudinal reinforcement, 5.2-beam transverse reinforcement, 5.2.1-closed stirrups, 5.2.2-transverse tension bar, 5.2.3-rear closed stirrups, 5.2.4-open U-shaped stirrups, 5.2.5-rear closed bar, 6-beam reinforcement cage, 7-block spacers, 8-steel frame, 9-pre-restraint block, 10-positioning piece. Specific embodiments

[0030] In order to better understand the purpose, technical solution and function of the utility model, the utility model is further described in detail below in conjunction with the accompanying drawings. Here, the illustrative embodiments of the utility model and their descriptions are used to explain the utility model, but are not intended to limit the utility model.

[0031] In the description of the present utility model, it is to be understood that the terms "include / comprise", "consist of..." or any other variations thereof are intended to cover non-exclusive inclusion, so that a product, device, process or method including a series of elements includes not only those elements, but also other elements not explicitly listed when necessary, or also includes elements inherent to such product, device, process or method. In the absence of further restrictions, the elements defined by the sentences "include / comprise..." and "consist of..." do not exclude the presence of other identical elements in the product, device, process or method including the elements.

[0032] In the present utility model, unless otherwise clearly specified and limited, the term "fixed connection" should be understood in a broad sense, for example: it can be a sleeve connection, a lap joint, a welding connection, a bolt connection, or a combination of the above connections; the terms "installation", "connection", "connected" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be directly connected, or indirectly connected through an intermediate medium, it can be the internal connection of two components or the interaction relationship between two components; the term "through-length steel bar" means that the steel bar is continuous without disconnection, or the steel bar is disconnected but the disconnected steel bars are fixedly connected. For ordinary technicians in this field, the specific meanings of the above terms in the present utility model can be understood according to specific circumstances.

[0033] It should also be understood that terms such as "upper", "lower", "front", "back", "left", "right", "top", "bottom", "inside" and "outside" to indicate directions or positional relationships are based on the directions or positional relationships shown in the accompanying drawings and are only for the convenience of describing the present invention and simplifying the description. They do not indicate or imply that the device, component or structure referred to must have a specific direction, be constructed or operate in a specific direction, and should not be understood as a limitation on the present invention.

[0034] The following is a detailed description of the implementation of the present invention using preferred implementation methods in conjunction with the accompanying drawings.

[0035] like Figure 1 , Figure 2As shown, a pre-constrained block beam includes a block 1, a constraint cage 2, a polymer 3 and a beam reinforcement 5, wherein the constraint cage 2 includes a cage frame 2.1 and a constraint cage hole 2.2; the block 1 is built into the constraint cage 2 to form a pre-constrained block 9; the constraint cage 2 is closed at the end; the constraint cage 2 is a constraint reinforcement cage or a grid cage; the beam reinforcement 5 includes a beam longitudinal reinforcement 5.1 and a beam transverse reinforcement 5.2; the beam transverse reinforcement 5.2 is arranged at intervals along the beam longitudinal reinforcement 5.1 to form a beam reinforcement cage 6; the constraint cage 2 is surrounded by the beam reinforcement cage 6; the polymer 3 fills the gap in the pre-constrained block 9; the polymer 3 wraps the beam reinforcement cage 6 and fills the gap between the pre-constrained block 9 and the beam reinforcement cage 6; there is a polymer 3 at the constraint cage hole 2.2, so that the polymer 3 in the constraint cage 2 and the polymer 3 outside the constraint cage 2 are connected as one.

[0036] Since the utility model uses a block material 1 with a larger particle size in the pre-constrained block beam, compared with ordinary concrete beams, it can effectively reduce the amount of cement and small-particle sand and gravel in the beam, effectively saving energy and protecting the environment. When the sand and gravel in the beam uses artificial graded sand and gravel, the pre-constrained block beam can further reduce the high energy consumption and high dust caused by artificial graded sand and gravel.

[0037] Due to the presence of block material 1, the shrinkage creep of pre-constrained block material beam is smaller than that of ordinary concrete beam, thus avoiding the defect that ordinary concrete is prone to cracks during large-volume construction. Block material 1 can greatly reduce the amount of cement used and reduce the hydration heat during construction. For large-volume concrete, hydration heat will cause concrete cracking, resulting in a decrease in the mechanical properties of concrete and a reduction in the service life of the beam component. For pre-constrained block material beams, hydration heat can be reduced, and block material 1 can effectively absorb the hydration heat generated by the surrounding polymer 3, reduce the temperature difference with the surrounding area, and effectively avoid the hydration heat generated by the temperature difference.

[0038] The pre-constrained block beam constrains the block 1 in the cage and the polymer 3 in the constraint cage through the constraint cage 2 in the beam, thereby improving the strength and ductility of the combination of the block 1 and the polymer 3 in the constraint cage, and forming a block polymer with a constraint effect; the constraint cage 2 simultaneously connects the polymer 3 in the constraint cage and the polymer 3 outside the constraint cage, and there is polymer 3 at the constraint cage hole 2.2, so that the polymer 3 in the constraint cage 2 and the polymer 3 outside the constraint cage 2 are connected as a whole; the constraint cage 2 increases the reinforcement content of the pre-constrained block beam, and as a block polymer with a constraint effect, it bears the corresponding force, so that the polymer 3, the constraint cage 2 and the steel bars of the pre-constrained block beam are subjected to force together, and the overall mechanical properties of the pre-constrained block beam are achieved.

[0039] Moreover, during construction, the block material 1 is placed in the constraint cage 2 to form a pre-constrained block material 9, and multiple blocks can be hoisted and transported at one time, thereby improving construction efficiency; the constraint cage 2 can control the contact mode, contact area and shape of the block material 1 during construction, so that the polymer 3 can effectively fill the gaps between the blocks 1, effectively reduce quality defects, improve construction quality, and achieve structural safety.

[0040] In the utility model, the size of the constraint cage hole 2.2 is smaller than the size of the block material 1 at that location; the cage frame 2.1 includes a side wall frame 2.1.1 and an end closure 2.1.2; the end closure 2.1.2 is formed by extending the side wall frame 2.1.1 or is a dedicated end closure 2.1.2; the dedicated end closure 2.1.2 is connected to the side wall frame 2.1.1 as a whole; the cage frame 2.1 can fix the position of the block material 1, and the end closure 2.1.2 can close the cage frame 2.1 to prevent the block material 1 from falling off from the end; the end closure 2.1.2 is formed by extending the side wall frame 2.1.1, and the two are integrated, which is beneficial to improving the strength and ductility of the pre-constrained block material 9; the dedicated end closure 2.1.2 and the side wall frame 2.1.1 are combined for easy production.

[0041] The pre-constrained block 9 is located in the middle area of ​​the beam cross-section height. The distance between the pre-constrained block 9 and the upper and lower surfaces of the beam is not less than 10% of the beam height, which can improve the bending resistance of the beam.

[0042] In the utility model, the block material 1 and the polymer 3 do not undergo a chemical reaction that reduces strength or durability; the surface of the block material 1 is a rough surface; the rough surface of the block material 1 is tightly combined with the polymer 3. The particle size of the block material is 60mm to 400mm (small block material, including 400mm); 400mm to 800mm (medium block material, including 800mm); 800mm to 2000mm (large block material); large block materials and medium block materials can be used for large-section beams (beams with a cross-sectional size greater than 1500m), medium block materials can be used for medium-section beams (beams with a cross-sectional size of 800 to 1500mm, including beams with a cross-sectional size of 1500mm), and small block materials can be used for beams of various cross-sections. Reasonable configuration of blocks of different particle sizes and corresponding cross-sectional beams is conducive to improving the bearing capacity of the beams.

[0043] The mud content of the block is less than 0.7%, and it is not allowed to be concentrated in a few areas. The difference between the block particle size and the average block particle size is not more than 30% of the average particle size. The small difference in block particle size makes it easier to control the contact mode between blocks or reduce their contact area.

[0044] In the utility model, Figure 3 As shown, the restraint cage 2 is a restraint bar cage, and the cage frame 2.1 of the restraint bar cage is composed of restraint bars 4; the restraint bars 4 are steel bars or steel wires or FRP bars; the cage frame 2.1 of the grid cage is composed of metal mesh or steel plates with holes.

[0045] The restraining ribs 4 include longitudinal ribs 4.1, transverse ribs 4.2 and / or diagonal ribs 4.3; the end closures 2.1.2 of the restraining rib cage are formed by fixed connection or bending of the longitudinal ribs 4.1 or the diagonal ribs 4.3 at the ends or are independent end closures 2.1.2; the independent end closures 2.1.2 are fixedly connected to the longitudinal ribs 4.1 or the diagonal ribs 4.3; the fixed connection method is bolting, welding or binding connection.

[0046] The shape of the restraining cage 2 can be cylindrical, spherical, ellipsoidal, etc.

[0047] The distribution spacing of the restraining ribs 4 at the lower part of the restraining cage 2 is smaller than the distribution spacing at the upper part of the restraining cage 2; the grid size formed by the longitudinal ribs 4.1 and the transverse ribs 4.2 is smaller than the size of the block placed at the grid, preventing the block 1 from falling off.

[0048] The block material 1 is an old reinforced concrete block or an old concrete block, which is located in the middle of the beam and has little effect on the mechanical properties of the beam and can be recycled.

[0049] Polymer 3 is high-flow concrete, which includes self-compacting concrete and high-flow concrete. High-flow concrete requires sufficient powder content, and the coarse aggregate can be 5-15mm or 5-25mm in particle size. High-flow concrete is more conducive to filling the gaps between blocks and ensuring the overall compactness of pre-constrained block beams.

[0050] The cage 2.1 is made of steel, and the strength of the steel is not less than 300Mpa; the volume ratio of the block 1 to the constraint cage 2 is 5% to 85%; the volume ratio of the block 1 to the polymer 3 is 5% to 300%; the volume ratio of the cage 2.1 to the constraint cage 2 is 0.02% to 3%. This can improve the strength and ductility of the pre-constrained block beam.

[0051] In the utility model, Figure 4 , Figure 5 As shown, the cage 2.1 of the pre-constrained block beam has multiple sub-spaces; the sub-spaces are independent of each other and contain blocks 1. The sub-spaces are formed by the cage 2.1 being divided by block spacers 7 or external constraints or welds or constraint ribs 4; or the lateral connectors are hooped together by external constraint ribs to form multiple sub-spaces.

[0052] The multiple subspaces divide the block material into multiple parts, which can increase the bonding strength and ductility between the block material 1 and the polymer 3 and facilitate production and transportation.

[0053] The block spacer 7 is composed of a steel mesh or a perforated steel plate, and is fixedly connected to the side wall frame 2.1.1; the gaps in the steel mesh are smaller than the size of the block 1; the hole size of the perforated steel plate is smaller than the size of the block 1; the block spacer 7 is arranged longitudinally and / or transversely and / or vertically.

[0054] In the utility model, Figure 6 , Figure 7 As shown, there are multiple pre-constrained blocks 9 in the pre-constrained block beam; positioning members 10 are arranged between the pre-constrained blocks 9; and the polymer 3 fills the gaps between the pre-constrained blocks 9.

[0055] A plurality of pre-constrained blocks 9 can reduce the amount of polymer 3 used, and the positioning member 10 can effectively fix the pre-constrained blocks 9 to prevent or reduce adverse effects such as displacement or tilting caused by pouring the polymer 3 during construction.

[0056] The clearance of the pre-constrained block material 9 is not less than 15 mm, so that the polymer 3 and the pre-constrained block material 9 can be closely combined.

[0057] In the utility model, Figure 8 As shown, a steel frame 8 is provided inside the beam reinforcement cage 6; the steel frame 8 is a steel section or a steel component; there is a gap between the steel frame 8 and the pre-constrained block material 9 and the beam reinforcement cage 6; the polymer 3 fills the gap between the pre-constrained block material 9, the steel frame 8 and the beam reinforcement cage 6.

[0058] In the utility model, Fig. 9 As shown, the transverse reinforcement 5.2 of the beam includes closed stirrups 5.2.1, transverse tension bars 5.2.2 and rear closed stirrups 5.2.3; the rear closed stirrups 5.2.3 are composed of open U-shaped stirrups 5.2.4 and rear closed bars 5.2.5; the rear closed bars 5.2.5 include rear closed tension bars or rear closed U-shaped stirrups; the rear closed bars 5.2.5 are arranged correspondingly to the open U-shaped stirrups 5.2.4.

[0059] During the construction, the pre-constrained block material 9 is put into the opening, and the net distance between the pre-constrained block material 9 and the beam reinforcement cage 6 is not less than 20 mm; after the construction, it is closed and the polymer 3 is poured.

[0060] In the utility model, Fig.10 As shown, a connection system of pre-constrained block beams includes a pre-constrained block beam A and a reinforced concrete column B, wherein the pre-constrained block beam A is fixedly connected to the reinforced concrete column B to form a beam-column node area; the reinforced concrete column B has column longitudinal steel bars, column transverse steel bars and column concrete; the column transverse steel bars are arranged at intervals along the longitudinal direction of the column; the beam longitudinal steel bars 5.1 extend into the reinforced concrete column B, are located in the gap between the column transverse steel bars and the column longitudinal steel bars, and are wrapped by the column concrete; there is no pre-constrained block material 9 in the beam-column node area.

[0061] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any modifications, equivalent substitutions and improvements made by any technician familiar with the technical field within the technical scope disclosed in the present invention should be covered by the protection scope of the present invention.

Claims

1. A pre-constrained block beam, characterized in that: The pre-constrained block beam comprises a block (1), a constraint cage (2), a polymer (3) and a beam reinforcement (5); the constraint cage (2) comprises a cage frame (2.1) and a constraint cage hole (2.2); the block (1) is built into the constraint cage (2) to form a pre-constrained block (9); the constraint cage (2) is closed at the end; the constraint cage (2) is a constraint reinforcement cage or a grid cage; the beam reinforcement (5) comprises a beam longitudinal reinforcement (5.1) and a beam transverse reinforcement (5.2); the beam transverse reinforcement (5.2) ) are arranged at intervals along the longitudinal reinforcement (5.1) of the beam to form a beam reinforcement cage (6); the constraint cage (2) is surrounded by the beam reinforcement cage (6); the polymer (3) fills the gap in the pre-constrained block (9); the polymer (3) wraps the beam reinforcement cage (6) and fills the gap between the pre-constrained block (9) and the beam reinforcement cage (6); the polymer (3) is present at the constraint cage hole (2.2), so that the polymer (3) in the constraint cage (2) and the polymer (3) outside the constraint cage (2) are connected as a whole.

2. The pre-constrained block beam according to claim 1, characterized in that: The size of the restraining cage hole (2.2) is smaller than the size of the block material (1) at that location; the cage frame (2.1) comprises a side wall frame (2.1.1) and an end closure member (2.1.2); the end closure member (2.1.2) is formed by extending the side wall frame (2.1.1) or is a dedicated end closure member (2.1.2); the pre-restrained block material (9) is located in the middle area of ​​the beam section height.

3. The pre-constrained block beam according to claim 1, characterized in that: The cage frame (2.1) of the restraining rib cage is composed of restraining ribs (4); the restraining ribs (4) are steel bars or steel wires or FRP bars; the cage frame (2.1) of the grid cage is composed of metal mesh or steel plates with holes.

4. The pre-constrained block beam according to claim 3, characterized in that: The restraining ribs (4) include longitudinal ribs (4.1), transverse ribs (4.2) and / or oblique ribs (4.3); the end closures (2.1.2) of the restraining rib cage are formed by fixedly connecting or bending the longitudinal ribs (4.1) or the oblique ribs (4.3) at the ends, or are independent end closures (2.1.2); the independent end closures (2.1.2) are fixedly connected to the longitudinal ribs (4.1) or the oblique ribs (4.3).

5. The pre-constrained block beam according to claim 1, characterized in that: The cage (2.1) has a plurality of sub-spaces; the sub-spaces are independent of each other and contain block materials (1).

6. The pre-constrained block beam according to claim 1, characterized in that: The beam reinforcement cage (6) is provided with a steel frame (8) inside; the steel frame (8) is a steel section or a steel component; there is a gap between the steel frame (8), the pre-constrained block material (9), and the beam reinforcement cage (6); the polymer (3) fills the gap between the pre-constrained block material (9), the steel frame (8), and the beam reinforcement cage (6).

7. The pre-constrained block beam according to claim 1, characterized in that: The transverse reinforcement (5.2) of the beam comprises closed stirrups (5.2.1), transverse tension bars (5.2.2) and rear closed stirrups (5.2.3); the rear closed stirrups (5.2.3) are composed of open U-shaped stirrups (5.2.4) and rear closed bars (5.2.5); the rear closed bars (5.2.5) comprise rear closed tension bars or rear closed U-shaped stirrups; the rear closed bars (5.2.5) are arranged correspondingly to the open U-shaped stirrups (5.2.4).

8. A connection system for pre-constrained block beams, comprising the pre-constrained block beam (A) according to any one of claims 1 to 7 and a reinforced concrete column (B), characterized in that: The pre-constrained block beam (A) is fixedly connected to the reinforced concrete column (B) to form a beam-column node area; the longitudinal reinforcement of the beam (5.1) extends into the reinforced concrete column (B), is located in the gap between the transverse reinforcement of the column and the longitudinal reinforcement of the column, and is wrapped by the column concrete; there is no pre-constrained block (9) in the beam-column node area.

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