Prefabricated prestressed concrete beam-slab joint

Abstract

The utility model discloses an assembly type prestressed concrete beam slab joint for connecting prestressed concrete composite floor and prestressed steel-concrete composite beam. The reinforced concrete floor body of the prestressed concrete composite floor adopts first tension method prestress one-time pouring forming, and the upper part of the slab end has a vacancy relative to the composite beam, forming a thickness reduction section as the engagement space filled by post-cast concrete. The longitudinal stress reinforcement and prestressed reinforcement in the reinforced concrete floor body extend to the composite layer of the beam, and together with the beam body steel framework, form dense steel mesh. The thickness reduction section creates "engagement space" for on-site pouring, allowing concrete to flow smoothly into the wrapped slab edge reinforcement, filling densely, improving the overall integrity and shear capacity of the joint. At the same time, the "steel mesh" formed by the key steel reinforcement in the slab extending to the composite layer makes the prefabricated slab and the composite beam form a nearly rigid or semi-rigid high-performance connection, which can more efficiently transfer the load when bearing the load and improve the shear capacity of the joint.

Description

Technical Field

[0001] This utility model relates to the technical field of prefabricated buildings and precast building components, and in particular to a prefabricated prestressed concrete beam-slab joint. Background Technology

[0002] In prefabricated concrete building structures, the connection details between precast floor slabs (including prestressed hollow slabs, double-T slabs, and other precast slab types) and precast beams (or composite beams) are a core element determining the overall performance of the building structure. Their quality directly affects several key indicators such as structural integrity, seismic performance, and construction efficiency. However, the traditional connection methods commonly used in current engineering practice present numerous technical challenges that urgently need to be addressed. 1. Weak bond performance and insufficient integrity at slab-beam joints: Current practices typically involve simply placing precast slabs on beams or beam trunnions, relying solely on the limited reinforcement extending from the slab ends (in most cases, only negative moment reinforcement) to connect with the post-cast concrete of the beam. This connection method results in a severely insufficient bond contact area, making the interface region a weak point in the structure. It not only fails to meet shear resistance requirements but also cannot effectively transfer bending moments, ultimately significantly weakening the overall stiffness of the structure.

[0003] 2. The prestressing effect is not fully utilized: In the application of precast prestressed slabs, the prestressing tendons are usually cut off at the ends of the slab or simply anchored. This construction method makes it impossible for the strength advantage of the prestressing material to be effectively extended to the joint area, resulting in a serious waste of valuable prestressing resources.

[0004] Although various improvement schemes have been proposed in the engineering field (such as setting shear keyways, adding U-shaped reinforcing bars, and adopting wet connection technology), these technical measures generally suffer from inherent defects such as high structural complexity, cumbersome construction procedures, increased economic costs, or failure to effectively utilize the advantages of prestressing. Therefore, developing a high-performance connection structure that combines structural rationality, ease of construction, and economy, while fully leveraging the performance advantages of precast components, has become a key issue that urgently needs to be addressed in the development of prefabricated building technology. Summary of the Invention

[0005] To address the aforementioned problems, this utility model aims to provide a prefabricated prestressed concrete beam-slab joint to solve many issues existing in precast floor slabs, improving the joint's bonding performance, integrity, and prestress utilization efficiency. This joint, with its unique structural design, effectively overcomes the shortcomings of traditional connection methods.

[0006] To achieve the above objectives, this utility model discloses a prefabricated prestressed concrete beam-slab joint for connecting a prestressed concrete composite floor slab and a prestressed steel-concrete composite beam. The key features are: the prestressed concrete composite floor slab includes a reinforced concrete slab body formed by prestressing in a single casting using the pre-tensioning method; the reinforced concrete slab body has a gap at the upper end relative to the prestressed steel-concrete composite beam, thus forming a thinned section; this thinned section serves as an interlocking space for the subsequent filling of the prestressed steel-concrete composite beam with cast concrete; wherein the longitudinal reinforcing bars and prestressing tendons arranged within the reinforced concrete slab body extend to the composite layer of the prestressed steel-concrete composite beam, thereby forming a dense steel mesh together with the beam reinforcement skeleton of the composite layer.

[0007] Furthermore, the thinned section is also provided with end reinforcement bars that act on the post-cast concrete of the prestressed steel-concrete composite beam.

[0008] Furthermore, the longitudinal reinforcing bars consist of top longitudinal bars and bottom longitudinal bars, with upper and lower transverse distribution bars arranged between them.

[0009] Furthermore, the top longitudinal reinforcement of the slab is made of negative moment reinforcement, and the bottom longitudinal reinforcement is made of prestressed reinforcement.

[0010] Furthermore, the thickness of the reinforced concrete floor slab in the non-thickness reduction section is twice the thickness of the thickness reduction section.

[0011] Furthermore, the length of the thickness reduction section is 200mm-300mm.

[0012] Furthermore, the interface between the thickness-reduced section and the post-cast concrete of the prestressed steel-concrete composite beam is set as a rough surface.

[0013] Furthermore, the prestressed steel-concrete composite beam includes a precast layer and a composite layer. The precast layer is prestressed and cast in one go using the pre-tensioning method, and steel connectors are installed at both ends in an embedded manner. Inside the concrete of the precast layer, the entire beam reinforcement skeleton is constructed by configuring bottom longitudinal bars, top longitudinal bars, web bars, tie bars, and stirrups. The top longitudinal bars of the slab are lapped with the top longitudinal bars of the beam, and the bottom longitudinal bars of the slab extend to the space between the concrete of the precast layer and the top longitudinal bars of the beam.

[0014] Furthermore, the height of the composite layer of the prestressed steel-concrete composite beam is consistent with the full thickness of the prestressed concrete composite floor slab.

[0015] Compared with the prior art, the significant advantages of this utility model are: (1) Regarding the reinforced concrete floor slab itself, the arrangement and extension of the internal reinforcement is a key factor in improving the performance of the joint. The longitudinal reinforcing bars and prestressing bars extend to the composite layer of the prestressed steel-concrete composite beam, forming a dense steel mesh with the beam reinforcement skeleton. This mesh acts like a tight three-dimensional network, closely connecting the floor slab and the composite beam, creating a near-rigid or semi-rigid high-performance connection between the precast slab and the composite beam. When bearing loads, the steel mesh can transfer loads more efficiently, giving the joint superior shear resistance and avoiding the structural weakness caused by the traditional practice of only extending the main reinforcing bars. This connection method achieves a qualitative leap in structural performance, significantly enhancing the integrity and continuity of the floor slab, significantly improving the seismic performance of the structure, effectively improving the dynamic response characteristics of the structure, providing a higher level of protection for the safety of the building structure, and making the overall structural performance far exceed conventional design standards. (2) The design of the thickness reduction section is also of great significance. With the help of the thickness reduction section at the end of the slab, a depth-optimized "interlocking space" is created at the junction of the precast slab and the beam composite layer, so that the post-cast concrete can flow more smoothly and wrap the steel bars extending from the edge of the slab, especially the wrapping effect on the longitudinal bars at the top of the slab is very significant. During the on-site pouring process, the concrete can fully fill the space to form a dense structure. This design not only greatly increases the effective anchorage length of the steel bars, but also significantly expands the bonding contact area between the steel bars and the concrete, thereby comprehensively improving the shear bearing capacity, bending stiffness and negative bending moment transmission capacity of the joint in terms of mechanical properties, making the structural connection more reliable and stable; (3) Regarding the application of prestressing, on the one hand, the prestressing tendons are extended as the bottom longitudinal reinforcement of the slab and anchored in the beam joint area. The prestressing effect not only acts on the slab itself, but its residual stress also plays multiple roles in the joint area, such as effectively restraining concrete deformation, significantly inhibiting crack propagation, and improving the overall stiffness and crack resistance of the joint area. This design fully explores and utilizes the full life cycle value of the prestressing tendons, and maximizes the utilization of material properties. On the other hand, the prestressed steel-concrete composite beam is also positively affected by the prestressing effect. The precast layer is prestressed and cast in one go using the pre-tensioning method, so that the beam has a certain initial stress during the construction stage, which can better resist various loads during subsequent construction and use. During the construction of the composite layer, the post-cast concrete connects the precast layer and the thickness reduction section into one, further enhancing the overall performance of the joint; (4) From the perspective of construction convenience and economy, the node design of this utility model has obvious advantages. The reinforced concrete floor slab body cast in one piece by prestressing and the prestressed steel-concrete composite beam cast in one piece by prestressing can both be produced in a standardized manner in the factory. This prefabrication production mode not only ensures the quality and precision of the components, but also greatly shortens the on-site construction time. During on-site installation, it is only necessary to splice the prefabricated floor slab body and the composite beam, and then pour the post-cast concrete. The thickness reduction section makes the pouring of post-cast concrete smoother, reduces the construction difficulty and construction error, and improves the construction efficiency and quality. At the same time, due to the improvement of node performance, the cost of later maintenance and reinforcement is reduced, and the overall cost of the entire building project is reduced. (5) The setting of end reinforcement bars is also a major highlight of this utility model. The end reinforcement bars are located in the thickness reduction section. They act as a sturdy "guardian" and play a role in strengthening the connection between the concrete and the slab during the filling process of the post-cast concrete of the composite beam. The end reinforcement bars can effectively disperse stress and prevent stress concentration in the joint area, further improving the shear resistance and integrity of the joint. At the same time, the end reinforcement bars, longitudinal reinforcing bars and prestressing bars work together to form a more stable steel reinforcement system, enabling the joint to work more reliably when subjected to various complex loads; (6) The interface between the thickness reduction section and the post-cast concrete of the prestressed steel-concrete composite beam is set as a rough surface, which further increases the friction and bonding force between the concrete, just like adding "grooves" between two objects, making them bond more tightly. This rough surface design makes the bond between the post-cast concrete and the thickness reduction section stronger, and can work together better when subjected to external forces, effectively reducing the relative sliding and separation between the interfaces, thereby further improving the overall performance and reliability of the joint. At the same time, the rough surface can also increase the pull-out resistance of the concrete, preventing the concrete from separating from the steel reinforcement when subjected to tensile forces, ensuring the safety and stability of the joint under various complex stress states. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 This is a schematic diagram of the overall structure of the prefabricated prestressed concrete beam-slab joint in Example 1 (I). Figure 2This is a schematic diagram of the overall structure of the prefabricated prestressed concrete beam-slab joint in Example 1 (II); Figure 3 This is a schematic diagram of the external structure of the reinforced concrete floor slab in Example 1 (I); Figure 4 This is a schematic diagram of the external structure of the reinforced concrete floor slab in Example 1 (II); Figure 5 This is a schematic diagram of the internal structure of the reinforced concrete floor slab in Example 1 (I); Figure 6 This is a schematic diagram (II) of the internal structure of the reinforced concrete floor slab in Example 1. The numbers in the diagram are: 1-Prestressed concrete composite floor slab, 2-Prestressed steel-concrete composite beam, 3-Slab end reinforcement, 101-Reinforced concrete floor slab body, 102-Thickness reduction section, 103-Top longitudinal reinforcement of slab, 104-Prestressed tendon, 105-Upper layer transverse distribution reinforcement, 106-Lower layer transverse distribution reinforcement, 107-Keyway, 201-Precast layer, 202-Composite layer, 203-Steel connector, 204-Beam reinforcement skeleton. Detailed Implementation

[0018] The embodiments of this utility model are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain this utility model, and should not be construed as limiting this utility model.

[0019] In the description of this utility model, it should be understood that the terms "length," "width," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the accompanying drawings and are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model. Furthermore, in the description of this utility model, "a plurality of" means two or more, unless otherwise explicitly specified.

[0020] Figures 1 to 6The first embodiment of the present invention is shown: a prefabricated prestressed concrete beam-slab joint for connecting a prestressed concrete composite floor slab 1 and a prestressed steel-concrete composite beam 2. The prestressed concrete composite floor slab 1 includes a reinforced concrete floor slab body 101 formed by prestressing in a single casting using the pre-tensioning method. The reinforced concrete floor slab body 101 has a gap at the upper part of the slab end relative to the prestressed steel-concrete composite beam 2, thereby forming a thickness reduction section 102. The thickness reduction section 102 serves as an interlocking space for the subsequent filling of the prestressed steel-concrete composite beam 2 with concrete. The longitudinal reinforcing bars and prestressing bars 104 arranged in the reinforced concrete floor slab body 101 extend to the composite layer 202 of the prestressed steel-concrete composite beam 2, thereby forming a dense steel mesh together with the beam reinforcement skeleton 204 of the composite layer 202.

[0021] In this embodiment, the prestressed concrete slab body 101 is formed by pre-tensioning and one-time casting, which ensures the overall strength and stability of the slab. The resulting thinning section 102 is the ingenious part of the entire structure. When the post-cast concrete of the composite beam 2 fills into this interlocking space, it forms a strong anchoring force with the longitudinal reinforcing bars and prestressing tendons 104 extending outward from the edge of the slab.

[0022] like Figure 1 As shown, in specific implementation, slab end reinforcing bars 3 are also provided on the thickness reduction section 102 to act on the post-cast concrete of the prestressed steel-concrete composite beam 2. These slab end reinforcing bars 3 act as a strong safety net for the joint area, playing a crucial role in the connection between the prestressed concrete composite slab 1 and the prestressed steel-concrete composite beam 2. During construction, under the constraint of the slab end reinforcing bars 3, the post-cast concrete can better fill the interlocking space formed by the thickness reduction section 102, avoiding concrete voids or incomplete compaction. From a mechanical perspective, the slab end reinforcing bars 3 cooperate with the longitudinal reinforcing bars and prestressing tendons 104 to jointly bear loads from all directions. When the structure is subjected to vertical loads, the slab end reinforcing bars 3 can assist the longitudinal reinforcing bars in transferring the load to the beam, reducing the burden on the longitudinal reinforcing bars and preventing them from failing due to excessive stress. Under horizontal loads, such as lateral forces generated by earthquakes, the end stiffeners 3 can enhance the shear and bending resistance of the joint, ensuring its stability even under complex stress conditions. Furthermore, the addition of end stiffeners 3 improves the joint's durability. During long-term use, the structure is affected by environmental factors such as humidity changes and temperature cycles, which can lead to microcracks in the concrete. The end stiffeners 3 can limit the propagation of these microcracks and prevent moisture and harmful chemicals from penetrating the concrete, thereby extending the joint's service life.

[0023] like Figure 5 and Figure 6 As shown, the longitudinal reinforcement consists of top longitudinal bars 103 and bottom longitudinal bars, with upper transverse distribution bars 105 and lower transverse distribution bars 106 arranged between them. The top longitudinal bars 103 are negative moment bars, which play a key role in the connection with the beam composite layer 202. During actual stress, the negative moment bars can effectively resist the negative bending moment generated at the beam end, rationally transferring the force to the entire structure and enhancing the bending resistance of the structure. The bottom longitudinal bars are prestressed tendons 104, which are extended and anchored in the beam joint area. The presence of the prestressed tendons 104 gives the floor slab a certain prestress before bearing the load. When the floor slab bears external loads, the prestress can offset part of the tensile stress, thereby delaying the generation and development of cracks and improving the crack resistance and durability of the floor slab. The upper transverse distribution bars 105 and the lower transverse distribution bars 106 extend transversely beyond the edge of the slab, intertwining with the longitudinal reinforcing bars to form a robust steel reinforcement skeleton, enhancing the overall rigidity of the reinforced concrete slab body 101. When these extended sections of the distribution bars combine with the post-cast concrete, they further increase the bond strength between the steel bars and the concrete, enabling the post-cast concrete to work better in conjunction with the composite slab 1.

[0024] In specific application scenarios, the thickness of the reinforced concrete floor slab body 101 in the non-thickness-reduced section 102 is twice the thickness of the thickness-reduced section 102. This reasonable thickness design ensures the load-bearing capacity of the floor slab in the main area and facilitates the filling of post-cast concrete and the anchoring of reinforcing bars in the thickness-reduced section 102. The length of the thickness-reduced section 102 is 200mm-300mm. This size range has been verified in construction to meet the requirements of the concrete flowing into and wrapping the extended reinforcing bars at the edge of the composite beam 202 without affecting the overall structural performance of the floor slab due to excessive length.

[0025] The interface between the thinned section 102 and the post-cast concrete of the prestressed steel-concrete composite beam 2 is roughened. This roughened surface design significantly increases the friction and adhesion of the interface, allowing the post-cast concrete to bond better with the precast floor slab, thus improving the integrity and shear resistance of the joint. Simultaneously, keyways 107 (see figure) are provided at the ends of the reinforced concrete floor slab 101 connecting adjacent components. The presence of keyways 107 further enhances the connection strength and integrity between the precast slab and adjacent components, making the entire building structure more stable and reliable.

[0026] Please see Figure 2In this embodiment, the prestressed steel-concrete composite beam 2 includes a precast layer 201 and a composite layer 202. The precast layer 201 is prestressed and cast in one piece using the pre-tensioning method, and steel connectors 203 are embedded at both ends. Inside the concrete of the precast layer 201, the entire beam reinforcement skeleton 204 is constructed by configuring bottom longitudinal bars, top longitudinal bars, web bars, tie bars, and stirrups. The top longitudinal bars 103 are lapped with the top longitudinal bars of the beam, and the bottom longitudinal bars extend to the space between the concrete of the precast layer 201 and the top longitudinal bars. This arrangement of reinforcements ensures a tight structural connection between the reinforced concrete slab and the prestressed steel-concrete composite beam 2, effectively transferring the load on the slab. During the construction of the composite layer 202, the surface of the precast layer 201 is first cleaned and roughened to ensure good adhesion between the composite layer 202 and the precast layer 201. The composite layer 202 is poured in two stages using high-performance concrete with a strength grade slightly higher than that of the precast layer 201 concrete, in order to improve the overall performance of the composite beam 2.

[0027] Specifically, the height of the composite layer 202 of the prestressed steel-concrete composite beam 2 is consistent with the full thickness of the prestressed concrete composite floor slab 1. This allows the composite beam 2 and the composite floor slab 1 to achieve a perfect fit in vertical space, further enhancing their collaborative working ability. During actual stress loading, the composite beam 2 and the composite floor slab 1 can share the external load, avoiding stress concentration that may occur due to height differences, resulting in a more uniform and reasonable stress distribution throughout the entire structural system. Furthermore, the design that the height of the composite layer 202 is consistent with the full thickness of the composite floor slab 1 simplifies dimensional control and elevation adjustment during construction, reduces construction errors, and improves construction efficiency and quality. Simultaneously, this design facilitates the installation of waterproofing structures, forming a continuous and complete waterproof layer at the junction of the composite beam 2 and the composite floor slab 1, effectively preventing the leakage of rainwater or other liquids and extending the service life of the structure. In addition, from an architectural aesthetic perspective, the consistent height makes the internal structural surfaces of the building smoother and more regular, providing a good foundation for subsequent decoration and finishing work, and contributing to the creation of a simple and elegant interior space environment.

[0028] In summary, the prefabricated prestressed concrete beam-slab joint design of this utility model exhibits significant advantages in several aspects: Regarding the reinforced concrete floor slab 101, the arrangement and extension of the internal reinforcing bars are key factors in improving the joint performance. The longitudinal reinforcing bars and prestressed tendons 104 extend to the composite layer 202 of the prestressed steel-concrete composite beam 2, forming a dense reinforcing mesh with the beam's reinforcing skeleton 204. This mesh acts like a tight three-dimensional network, closely connecting the floor slab 101 and the composite beam 2, creating a near-rigid or semi-rigid high-performance connection between the precast slab and the composite beam 2. Under load, the reinforcing mesh can transfer loads more efficiently, giving the joint superior shear resistance and avoiding the structural weakness caused by the traditional approach of only extending the main reinforcing bars. This connection method represents a qualitative leap in structural performance, significantly enhancing the integrity and continuity of the floor slab, significantly improving the seismic performance of the structure, effectively improving the dynamic response characteristics of the structure, providing a higher level of protection for building structural safety, and making the overall structural performance far exceed conventional design standards. The design of the thickness reduction section 102 is also of great significance. By utilizing the thickness reduction section 102 at the slab end, a depth-optimized "interlocking space" is created at the junction of the precast slab and the beam composite layer 202, allowing the post-cast concrete to flow more smoothly and wrap around the reinforcing bars extending from the slab edge, especially significantly wrapping the longitudinal reinforcement 103 at the top of the slab. During on-site pouring, the concrete can fully fill this space, forming a dense structure. This design not only significantly increases the effective anchorage length of the reinforcing bars but also significantly expands the bond contact area between the reinforcing bars and concrete, thereby comprehensively improving the shear capacity, flexural stiffness, and negative moment transfer capacity of the joint in terms of mechanical properties, making the structural connection more reliable and stable. Regarding the application of prestressing, on the one hand, the prestressing tendons 104 are extended as longitudinal reinforcement at the bottom of the slab and anchored in the beam joint area. The prestressing effect not only acts on the slab itself, but its residual stress also plays multiple roles in the joint area, such as effectively restraining concrete deformation, significantly inhibiting crack propagation, and improving the overall stiffness and crack resistance of the joint area. This design fully explores and utilizes the full life cycle value of the prestressing tendons 104, maximizing the utilization of material properties. On the other hand, the prestressed steel-concrete composite beam 2 is also positively affected by the prestressing effect. The precast layer 201 is prestressed and cast in one go using the pre-tensioning method, so that the beam has a certain initial stress during the construction stage, which can better resist various loads during subsequent construction and use. During the construction of the composite layer 202, the post-cast concrete connects the precast layer 201 and the thickness reduction section 102 into one, further enhancing the overall performance of the joint. From the perspectives of ease of construction and economy, the node design of this utility model has significant advantages. Both the prestressed reinforced concrete floor slab body 101, cast in one piece using the prestressed prestressing method, and the prestressed steel-concrete composite beam 2, cast in one piece using the prestressed prestressing method, can be produced in a standardized factory. This prefabrication production mode not only ensures the quality and precision of the components but also significantly shortens on-site construction time. During on-site installation, only the prefabricated floor slab body 101 and the composite beam 2 need to be spliced ​​together, followed by the pouring of post-cast concrete. The thickness reduction section 102 makes the pouring of post-cast concrete smoother, reducing construction difficulty and errors, and improving construction efficiency and quality. At the same time, due to the improved node performance, the cost of later maintenance and reinforcement is reduced, lowering the overall cost of the entire construction project. The addition of end-reinforcing ribs 3 is a major highlight of this invention. Located in the thickness-reducing section 102, the end-reinforcing ribs 3 act as sturdy "guardians," enhancing the connection between the concrete and the slab during the post-cast concrete filling process of the composite beam 2. The end-reinforcing ribs 3 effectively disperse stress, preventing stress concentration in the joint area and further improving the shear resistance and overall integrity of the joint. Simultaneously, the end-reinforcing ribs 3, in conjunction with the longitudinal reinforcing bars and prestressed tendons 104, form a more robust steel reinforcement system, enabling the joint to function more reliably under various complex loads. The interface between the thinned section 102 and the post-cast concrete of the prestressed steel-concrete composite beam 2 is roughened, further increasing the friction and adhesion between the concrete. This acts like adding "grooves" between two objects, making their bond tighter. This roughened surface design strengthens the bond between the post-cast concrete and the thinned section 102, allowing them to work together better under external forces, effectively reducing relative sliding and separation at the interface, thus further improving the overall performance and reliability of the joint. Simultaneously, the roughened surface increases the pull-out resistance of the concrete, preventing separation between the concrete and reinforcing steel under tensile forces, ensuring the safety and stability of the joint under various complex stress conditions.

[0029] The above-disclosed embodiments are merely preferred embodiments of the present utility model and should not be construed as limiting the scope of the present utility model. Those skilled in the art can understand that implementing all or part of the above-described embodiments and making equivalent changes in accordance with the claims of the present utility model are still within the scope of the utility model.

Claims

1. A prefabricated prestressed concrete beam-slab joint for connecting a prestressed concrete composite floor slab and a prestressed steel-concrete composite beam, characterized in that: The prestressed concrete composite floor slab includes a reinforced concrete floor slab body formed by prestressing in a single casting using the pre-tensioning method; the reinforced concrete floor slab body has a gap at the upper part of the slab end relative to the prestressed steel-concrete composite beam, thus forming a thickness reduction section; this thickness reduction section serves as an interlocking space for the subsequent filling of the prestressed steel-concrete composite beam with cast concrete; wherein, the longitudinal reinforcing bars and prestressing bars arranged in the reinforced concrete floor slab body extend to the composite layer of the prestressed steel-concrete composite beam, thereby forming a dense steel mesh together with the beam reinforcement skeleton of the composite layer.

2. The fabricated prestressed concrete beam-slab joint of claim 1, wherein: The thinning section is also provided with end reinforcement bars that act on the post-cast concrete of the prestressed steel-concrete composite beam.

3. The fabricated prestressed concrete beam-slab joint according to claim 1 or 2, characterized in that: The longitudinal reinforcing bars consist of top longitudinal bars and bottom longitudinal bars, with upper and lower transverse distribution bars arranged between them.

4. The fabricated prestressed concrete beam-slab joint of claim 3, wherein: The top longitudinal reinforcement of the slab is a negative moment reinforcement, and the bottom longitudinal reinforcement is a prestressed reinforcement.

5. The precast prestressed concrete beam-slab joint according to claim 1 or 4, characterized in that: The thickness of the reinforced concrete floor slab in the non-thickness reduction section is twice the thickness of the thickness reduction section.

6. The fabricated prestressed concrete beam-slab joint of claim 5, wherein: The length of the thickness reduction section is 200mm-300mm.

7. The precast prestressed concrete beam-slab joint according to claim 6, characterized in that: The interface between the thickness reduction section and the post-cast concrete of the prestressed steel-concrete composite beam is set as a rough surface.

8. The fabricated prestressed concrete beam-slab joint of claim 4, wherein: The prestressed steel-concrete composite beam includes a precast layer and a composite layer. The precast layer is prestressed and cast in one go using the pre-tensioning method, and steel connectors are installed at both ends in an embedded manner. Inside the concrete of the precast layer, the entire beam reinforcement skeleton is constructed by configuring bottom longitudinal bars, top longitudinal bars, web bars, tie bars, and stirrups. The top longitudinal bars of the slab are lapped with the top longitudinal bars of the beam, and the bottom longitudinal bars of the slab extend to the space between the concrete of the precast layer and the top longitudinal bars of the beam.

9. The precast prestressed concrete beam-slab joint of claim 8, wherein: The height of the composite layer of the prestressed steel-concrete composite beam is consistent with the full thickness of the prestressed concrete composite floor slab.

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