A uhcp connected post-tensioned unbonded co-tension prefabricated prestressed concrete frame structure system and its design and construction method

Abstract

The application discloses a UHPC connected post-tensioned non-bonded co-tension prefabricated prestressed concrete frame structure system, which comprises a prefabricated concrete upper column, a prefabricated concrete lower column, a post-tensioned non-bonded co-tension prefabricated prestressed concrete composite beam, a UHPC node core area and a composite slab. The structure system is not only convenient and fast in on-site construction and improves the component installation efficiency, but also can greatly reduce the steel bar anchoring length, greatly reduce the amount of stirrups in the node core area, avoid the congestion of the steel bars in the node core area, reduce the component section height, reduce the self weight, improve the component crack resistance and self-recovery performance, thereby improving the seismic performance of the overall frame structure. The pre-tensioned prestressed steel bars can make the prefabricated beam less supported or free of support during construction, thereby reducing the construction cost, and the post-tensioned non-bonding can enhance the integrity of the frame, so that the structure has a certain self-resetting capacity and structural toughness in the earthquake, and the post-earthquake repair cost is reduced.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of prefabricated prestressed assembly type building construction, in particular to a UHPC connected post-tensioned unbonded co-tension prefabricated prestressed concrete frame structure system and a design and construction method thereof. BACKGROUND

[0002] The construction efficiency of cast-in-place structure is low, and the energy loss is high, and many limitations, which gradually cannot meet the development requirements of building industrialization. Prefabricated assembly type building has become the development direction of building industrialization because of its fast construction speed, factory production of components, reduction of on-site wet work and reduction of environmental pollution. After years of development and promotion, prefabricated assembly type concrete structure has been widely researched and used.

[0003] Prefabricated assembly type concrete frame structure refers to the structure that beam-column components are prefabricated in a prefabrication plant and transported to the construction site for connection to form an integral structure. Compared with cast-in-place concrete structure, it has the advantages of fast construction speed, easy guarantee of component quality, good quality, less environmental pollution, saving of labor cost, and saving of a large amount of formwork and support, etc., and is a structure form with very broad prospects. For wet connection assembly type concrete frame structure, the node construction form which is easy to construct and effectively guarantees the integrity is the key to its popularization and application. However, from the past earthquake disasters, the assembly type structure is seriously damaged in the earthquake, and it is difficult to achieve the same seismic performance as the cast-in-place structure. In order to improve the integrity and reliability of the assembly type concrete frame node connection and achieve or even exceed the seismic performance of the cast-in-place concrete structure, prestressing technology and UHPC (Ultra High Performance Concrete, ultra high performance concrete) material are introduced into the assembly type structure.

[0004] Post-tensioned unbonded co-tension prestressed assembly type concrete structure is a structure formed by assembling prefabricated ordinary concrete components and prefabricated pretensioned prestressed components together to work together through tensioning of prestressed reinforcement, which has the characteristics of pretensioned prestressed, post-tensioned unbonded prestressed concrete structure and assembly type structure. The internal stress generated by prestress in the concrete section can partially or completely offset the stress in the section under the use load, delay the occurrence of cracks and improve the stiffness of the component. When unloaded, the cracks can be partially or completely closed, and the elastic recovery performance of the structure is good. At the same time, the prestressed concrete can fully utilize the material strength of the prestressed reinforcement and the concrete, and reduce the self-weight of the structure. And the application of prestress helps to improve the performance and integrity of the assembly type structure, and promotes the application of assembly type structure in large-span and heavy-load structures.

[0005] UHPC has excellent bonding performance, which can greatly reduce the anchorage length of steel bars and steel strands in it; it has high strength, which can reduce the amount of stirrups in the core area of the joint, and using UHPC in the core area of the joint can make the structure simple and the overall framework good. The prestressed structure has excellent stress performance, and the application of UHPC in the core area of the joint forms a prefabricated prestressed framework structure. Further research on this structure is conducive to the further promotion and application of prefabricated prestressed concrete framework structure. SUMMARY

[0006] The purpose of the present application is to overcome the shortcomings of the prior art, combined with the excellent performance of UHPC, a UHPC connected post-tensioned un-bonded co-tension prefabricated prestressed concrete framework structure system and its design and construction method are proposed. It combines three traditional structures: pretensioning prestressed structure, post-tensioned un-bonded prestressed structure and assembled structure, and uses UHPC high-performance materials, so as to improve the seismic performance of prefabricated assembled concrete framework structure.

[0007] The advantages of the present application mainly lie in the connection technology of prefabricated pretensioning prestressed concrete beam-column components and the steel bar connection technology between components. In terms of component connection technology, the beam-column components are connected by UHPC with excellent performance to form a UHPC joint core area, which is more conducive to achieving the seismic fortification requirements of strong joints and weak components, thereby improving the ductility of beam-column joints and improving the seismic performance of the overall framework structure. In terms of steel bar connection technology, the steel bars between beam-column components only need to be simply overlapped, and the overlap length is very small, thereby greatly saving the production time of prefabricated components and the installation time on site. Therefore, the UHPC connected post-tensioned un-bonded co-tension prefabricated prestressed concrete framework structure system and its design and construction method proposed by the present application meet the green development strategy of China's building industrialization.

[0008] The technical problems solved by the present application can be realized by using the following technical solutions:

[0009] A UHPC connected post-tensioned un-bonded co-tension prefabricated prestressed concrete framework structure system, comprising a prefabricated concrete upper column, a prefabricated concrete lower column, a post-tensioned un-bonded co-tension prefabricated prestressed concrete composite beam, a UHPC joint core area and a composite slab.

[0010] The prefabricated concrete upper column is provided with upper longitudinal main reinforcement, the prefabricated concrete lower column is provided with lower longitudinal main reinforcement, the post-tensioned un-bonded co-tension prefabricated prestressed concrete composite beam is provided with a prefabricated pretensioning prestressed concrete beam, a beam composite layer and a post-tensioned un-bonded prestressed reinforcement, the prefabricated pretensioning prestressed concrete beam is provided with ordinary steel bars and pretensioning prestressed reinforcement, the beam composite layer is provided with top longitudinal steel bars, and the composite slab is composed of a prefabricated concrete slab and a slab composite layer poured on the slab.

[0011] The upper longitudinal main reinforcement extends out of the bottom surface of the prefabricated upper column and is directly anchored in the UHPC node core area, the lower longitudinal main reinforcement extends out of the top surface of the prefabricated lower column and is directly anchored in the UHPC node core area, the ordinary steel and the pre-tensioned prestressed reinforcement extends out of the end surface of the prefabricated pre-tensioned prestressed concrete beam and is directly anchored in the UHPC node core area;

[0012] The pre-tensioned prestressed reinforcement includes straight and folded line-shaped reinforcement, and the post-tensioned unbonded prestressed reinforcement includes straight, folded, and curved line-shaped reinforcement.

[0013] The post-tensioned unbonded co-tensioned prefabricated prestressed concrete composite beam is calculated according to the pre-tensioned prestressed concrete simply supported beam before pouring the beam composite layer, the plate composite layer, and the UHPC node core area, after pouring the node core area and the beam composite layer and the plate composite layer, when the node and the composite layer concrete strength reaches the design requirement, the post-tensioning of the unbonded prestressed reinforcement is carried out, after the tensioning is completed, the construction stage calculation is carried out according to the frame beam; after the pre-stress is established, the construction calculation, the calculation of the normal use limit state are calculated by the effective pre-stress, and the stress increment is considered in the calculation of the bearing capacity limit state; under the seismic load, the recovery performance of the unbonded prestressed reinforcement to the node is considered.

[0014] Further, the post-tensioned unbonded co-tensioned prefabricated prestressed concrete composite beam is composed of a prefabricated pre-tensioned prestressed concrete beam, a beam composite layer, and a post-tensioned unbonded prestressed reinforcement; the composite plate is composed of a prefabricated concrete plate and a plate composite layer poured on the plate.

[0015] Further, the post-tensioned unbonded prestressed reinforcement is embedded in the prefabricated pre-tensioned prestressed concrete beam component and passes through the UHPC node core area and extends out of the UHPC node core area at both ends, and clamps and anchors are respectively fixed at both ends, one end is arranged outside the column, and the other end is arranged in the beam composite layer.

[0016] Further, the bottom surface of the prefabricated concrete upper column, the top surface of the prefabricated concrete lower column, and the end surface of the post-tensioned unbonded co-tensioned prefabricated prestressed concrete composite beam are provided with recesses (U-shaped grooves can also be arranged at the beam end, and constructional shear reinforcement can be arranged if necessary).

[0017] Further, the prefabricated concrete upper column is fixed in the corresponding position by reliable support.

[0018] Further, the stirrups in the precast concrete upper column, the precast concrete lower column and the post-tensioned unbonded and co-tensioned precast prestressed concrete composite beam are divided into an encryption area and a non-encryption area, the stirrups in the UHPC node core area are arranged according to design requirements, the shear bearing capacity of the core area is calculated according to the softened strut-and-tie model, and the steel fibers in the UHPC are equivalent to horizontal stirrups and vertical longitudinal reinforcement, the contribution of the steel fibers to the shear of the node core area is considered, and the beneficial contribution of the unbonded prestressed tendon to the shear of the node is considered.

[0019] Further, the top surface of the precast prestressed concrete beam and the precast concrete slab is provided with a rough surface layer.

[0020] The application also provides a design method of the system, including the following steps:

[0021] Step 1: the beam and the column are designed according to existing specifications and invention patents;

[0022] Step 2: the seismic design of the node needs to be carried out according to the following method, and the horizontal shear bearing capacity V of the node is calculated jh :

[0023] The shear bearing capacity of the frame beam-column node should meet the following provisions:

[0024]

[0025]

[0026]

[0027] Step 3: at the intermediate node in the intermediate layer of the frame, the upper longitudinal reinforcement of the frame beam should penetrate the intermediate node; the diameter of each beam longitudinal reinforcement penetrating the middle column should not be greater than the smaller value of 1 / 18 and x of the column sectional size in the direction when the column is a rectangular section for the first, second and third seismic grades; x is calculated according to the following formula:

[0028]

[0029] In the formula: - design axial compression ratio;

[0030] A s,top - the area of the longitudinal reinforcement at the top of the beam, if the areas of the longitudinal reinforcement at the bottom of the left and right beams are not equal, the average value is taken;

[0031] A s - the area of the longitudinal reinforcement at the top and bottom of the beam.

[0032] A kind of UHPC connection's post-tensioned unbonded and co-tensioned precast prestressed concrete frame structure system, including the following steps:

[0033] Step 1: making prefabricated concrete lower column, prefabricated concrete upper column, prefabricated pre-tensioned prestressed concrete beam, prefabricated concrete slab; wherein the prefabricated concrete lower column and the prefabricated concrete upper column extend the longitudinal reinforcement to be anchored into the node core area and need to reserve sufficient anchoring length; when prefabricating the pre-tensioned prestressed concrete beam, the pre-tensioned prestressed reinforcement is tensioned on the pedestal, the post-tensioned unbonded prestressed reinforcement is pre-buried in the beam according to the design position, and sufficient structural length is reserved at both ends, then the concrete is poured, the pre-tensioned prestressed reinforcement is released when the concrete is cured to sufficient strength, and sufficient anchoring length is reserved at the beam end;

[0034] Step 2: after the prefabricated components are cured, the prefabricated concrete lower column is hoisted and installed on the foundation, then a proper number of stirrups are installed on the extended longitudinal reinforcement;

[0035] Step 3: hoist the prefabricated pre-tensioned prestressed concrete beam to the top surface of the prefabricated concrete lower column, make the bottom surface of the prefabricated pre-tensioned prestressed concrete beam flush with the top surface of the prefabricated concrete lower column, make the end of the prefabricated pre-tensioned prestressed concrete beam rest on the prefabricated concrete lower column, and fix it with support, or it can be free of support due to the pre-tensioned prestressed action in the beam; wherein the ordinary steel reinforcement and the pre-tensioned prestressed reinforcement on both sides of the pre-tensioned prestressed concrete beam are reasonably avoided and directly anchored or bent and anchored in the node core area according to the structural requirements;

[0036] Step 4: hoist the prefabricated concrete upper column to directly above the prefabricated concrete lower column, fix the prefabricated concrete upper column in the corresponding position with reliable support, at this time, the stirrups installed in step 2 are tied together with the column longitudinal reinforcement; wherein the longitudinal reinforcement of the prefabricated concrete upper and lower columns is reasonably avoided and directly anchored in the node core area;

[0037] Step 5: pass the top longitudinal reinforcement through the stirrups reserved in the beam composite layer area and the node core area and tie them well, then tie the unbonded prestressed reinforcement pre-buried and extended in the pre-tensioned prestressed concrete beam in the node core area according to the design position, and then pour the UHPC node core area and set the formwork so that the UHPC does not enter the beam composite layer part;

[0038] Step 6: after the UHPC node core area is cured to sufficient strength, hoist the prefabricated concrete flat slab, composite slab, double-T slab or secondary beam to the prefabricated prestressed concrete beam and fix it;

[0039] Step 7: pour the beam composite layer and the slab composite layer;

[0040] Step 8: after the beam composite layer and the slab composite layer are cured to sufficient strength, tension the prestressed reinforcement;

[0041] Step 9: repeat the above manufacturing process to complete the post-tensioned unbonded co-tensioned prefabricated prestressed concrete frame structure system.

[0042] Compared with the prior art, the application has the advantages that:

[0043] 1. The application combines prefabricated concrete structure, pre-tensioned prestress and post-tensioned unbonded prestress structure together, and uses the advantages of prefabricated structure, such as convenient and fast construction, good construction quality, energy saving and environmental protection, and combines post-tensioned unbonded shared tension prestress structure to improve the structural performance, reduce the cross-section height of the component, reduce the self weight, improve the crack resistance and self-recovery of the component, thereby improving the seismic performance of the overall frame structure. The pre-tensioned prestress makes the prefabricated beam less supported or free of support during construction, reduces the construction cost, and the post-tensioned unbonded structure enhances the integrity of the frame, so that the structure has certain self-resetting capacity and structural toughness in the earthquake, and reduces the post-earthquake repair cost.

[0044] 2. The application adopts UHPC material with excellent performance, which is applied in the node core area, can realize reliable connection of the prefabricated beam and column component, not only can improve the bearing capacity and seismic performance of the node, but also can greatly reduce the anchoring length of the steel bar and steel strand, and can significantly reduce the amount of stirrup in the node core area, thereby avoiding the congestion of the steel bar in the node core area, and greatly improving the production, transportation and installation efficiency of the prefabricated beam and column component. BRIEF DESCRIPTION OF DRAWINGS

[0045] Figure 1 It is a structural schematic diagram of the prefabricated prestressed concrete frame structure system based on UHPC of the application

[0046] Figure 2 It is a reinforcement schematic diagram of a two-span frame structure of the application

[0047] Figure 3 It is a material schematic diagram of a two-span frame structure of the application

[0048] Figure 4 It is a detailed drawing of the edge node of the intermediate layer frame of the application

[0049] Figure 5 It is an axonometric view of the edge node of the intermediate layer frame of the application

[0050] Figure 6 It is a detailed drawing of the middle node of the intermediate layer frame of the application

[0051] Figure 7 It is an axonometric view of the middle node of the intermediate layer frame of the application DETAILED DESCRIPTION

[0052] In order to make the features, objects and advantages of the application more easily understood, the application will be further described below in combination with the drawings and specific embodiments.

[0053] AsFigures 1-7 The UHPC connected post-tensioned unbonded co-tension prefabricated prestressed concrete frame structure system comprises a prefabricated concrete upper column (1), a prefabricated concrete lower column (2), a post-tensioned unbonded co-tension prefabricated prestressed concrete composite beam (3), a UHPC node core area (4), and a composite slab (18).

[0054] The prefabricated concrete upper column (1) is internally provided with upper longitudinal main reinforcement (5), the prefabricated concrete lower column (2) is internally provided with lower longitudinal main reinforcement (6), the post-tensioned unbonded co-tension prefabricated prestressed concrete composite beam (3) is internally provided with a prefabricated pre-tensioned prestressed concrete beam (7) and a beam composite layer (8) and a post-tensioned unbonded prestressed reinforcement (9), the prefabricated pre-tensioned prestressed concrete beam (7) is provided with ordinary reinforcement (10) and pre-tensioned prestressed reinforcement (17), the beam composite layer (8) is internally provided with top-through steel bars (11), and the composite slab (18) is composed of a prefabricated concrete slab (19) and a slab composite layer (20) poured on the slab.

[0055] The upper longitudinal main reinforcement (5) extends out of the bottom surface of the prefabricated upper column (1) and is directly anchored in the UHPC node core area (4), the lower longitudinal main reinforcement (6) extends out of the top surface of the prefabricated lower column (2) and is directly anchored in the UHPC node core area (4), and the ordinary reinforcement (10) and the pre-tensioned prestressed reinforcement (17) extend out of the end surface of the prefabricated pre-tensioned prestressed concrete beam (7) and are directly anchored in the UHPC node core area (4).

[0056] The pre-tensioned prestressed reinforcement (17) comprises straight-line and folded-line-shaped reinforcement, and the post-tensioned unbonded prestressed reinforcement (9) comprises straight-line, folded-line, and curved-line-shaped reinforcement.

[0057] The post-tensioned unbonded co-tension prefabricated prestressed concrete composite beam (3) is calculated according to the pre-tensioned prestressed concrete simply supported beam before pouring the beam composite layer (8), the slab composite layer (20), and the UHPC node core area (4), after pouring the node core area (4) and the beam composite layer (8) and the slab composite layer (20), when the strength of the node and the composite layer concrete reaches the design requirement, the post-tensioned unbonded prestressed reinforcement (9) is tensioned, after the tensioning is completed, the construction stage calculation is performed according to the frame beam, the post-tensioned unbonded prestressed reinforcement (9) is calculated according to the effective prestress in the construction calculation and the normal use limit state calculation, and the stress increment is considered in the bearing capacity limit state calculation; under the seismic load, the recovery performance of the post-tensioned unbonded prestressed reinforcement (9) on the node is considered.

[0058] The post-tensioned unbonded co-tension prefabricated prestressed concrete composite beam (3) is composed of the prefabricated pre-tensioned prestressed concrete beam (7), the beam composite layer (8), and the post-tensioned unbonded prestressed reinforcement (9), and the composite slab (18) is composed of the prefabricated concrete slab (19) and the slab composite layer (20) poured on the slab.

[0059] The post-tensioned un-bonded prestressed tendon (9) is embedded in the prefabricated pre-tensioned prestressed concrete beam (7) component, passes through the UHPC node core area (4) and extends out of the UHPC node core area (4), and is fixed with a clamp (15) and an anchor (16) at both ends, one end being arranged outside the column and the other end being arranged in the beam composite layer.

[0060] The bottom surface of the prefabricated concrete upper column (1), the top surface of the prefabricated concrete lower column (2) and the end surface of the post-tensioned un-bonded co-tensioned prefabricated prestressed concrete composite beam (3) are provided with recessed grooves (U-shaped grooves can also be arranged at the beam ends, and construction shear reinforcement can be arranged if necessary).

[0061] The prefabricated concrete upper column (1) is fixed in the corresponding position by reliable support (12).

[0062] The stirrups (13) in the prefabricated concrete upper column (1), the prefabricated concrete lower column (2) and the post-tensioned un-bonded co-tensioned prefabricated prestressed concrete composite beam (3) are divided into densified areas and non-densified areas, the stirrups (14) in the UHPC node core area (4) are arranged according to design requirements, the shear bearing capacity of the core area is calculated according to the softened strut-and-tie model, and the steel fibers in the UHPC are equivalent to horizontal stirrups and vertical longitudinal reinforcement, and their contribution to the shear resistance of the node core area is considered, and the beneficial contribution of un-bonded prestressed tendons to the shear resistance of the node is also considered.

[0063] The top surface of the prefabricated pre-tensioned prestressed concrete beam (7) and the prefabricated concrete slab (19) is provided with a rough surface layer.

[0064] The seismic design of the system includes the following steps:

[0065] Step 1: The beam and column are designed according to existing specifications and invention patents;

[0066] Step 2: The seismic design of the node needs to be carried out according to the following method: calculate the horizontal shear bearing capacity V jh of the node.

[0067] Step 3: The diameter of each longitudinal steel bar penetrating the middle column should not be greater than the smaller value of 1 / 18 of the cross-sectional size of the column in that direction and x.

[0068] A UHPC connected post-tensioned un-bonded co-tensioned prefabricated prestressed concrete frame structure system, characterized by comprising the following steps:

[0069] Step 1: make prefabricated concrete lower column (2), prefabricated concrete upper column (1), prefabricated pre-tensioned prestressed concrete beam (7), prefabricated concrete slab (19); wherein the prefabricated concrete lower column (2), the prefabricated concrete upper column (1) extends the longitudinal reinforcement anchoring into the node core area (4) and needs to reserve enough anchoring length; when prefabricating the pre-tensioned prestressed concrete beam (7), the pre-tensioned prestressed reinforcement (17) is pre-tensioned on the pedestal, the post-tensioned unbonded prestressed reinforcement (9) is pre-buried in the beam according to the design position, and enough construction length is reserved at both ends, then the concrete is poured, and when the concrete is cured to enough strength, the pre-tensioned prestressed reinforcement (17) is released and enough anchoring length is reserved at the beam end;

[0070] Step 2: after the prefabricated components are cured, the prefabricated concrete lower column (2) is hoisted and installed on the foundation, then a proper number of stirrups (14) are installed on the extended longitudinal reinforcement (6);

[0071] Step 3: hoist the prefabricated pre-tensioned prestressed concrete beam (7) to the top surface of the prefabricated concrete lower column (2), make the bottom surface of the prefabricated pre-tensioned prestressed concrete beam (7) flush with the top surface of the prefabricated concrete lower column (2), make the end of the prefabricated pre-tensioned prestressed concrete beam (7) rest on the prefabricated concrete lower column (2), and fix it with support, and since the beam has pre-tensioned prestressed action, it can also be free of support; wherein the ordinary steel bars (10) and pre-tensioned prestressed reinforcement (17) extending from the pre-tensioned prestressed concrete beam (7) on both sides are reasonably avoided according to the construction requirements in the node core area and are directly anchored or bent and anchored;

[0072] Step 4: hoist the prefabricated concrete upper column (1) to the directly above the prefabricated concrete lower column (2), fix the prefabricated concrete upper column (1) in the corresponding position with reliable support (12), at this time, the stirrups (14) installed in step 2 are bound together with the column longitudinal reinforcement; wherein the longitudinal reinforcement extending from the prefabricated concrete upper and lower columns is reasonably avoided in the node core area and directly anchored;

[0073] Step 5: pass the top longitudinal steel bar (11) through the stirrup (13) reserved in the beam composite layer area and the node core area (4) and bind them well, then bind the unbonded prestressed reinforcement (9) pre-buried and extending from the pre-tensioned prestressed concrete beam (7) in the node core area according to the design position, and then pour the UHPC node core area (4) and set the formwork so that the UHPC does not enter the beam composite layer (8) part;

[0074] Step 6: after the UHPC node core area (4) is cured to enough strength, hoist the prefabricated concrete flat slab, composite slab, double T slab or secondary beam to the prefabricated prestressed concrete beam (7) and fix it;

[0075] Step 7: pour the beam composite layer (8) and the slab composite layer (20);

[0076] Step 8: after the beam superposition layer (8) and the plate superposition layer (20) are cured to sufficient strength, the prestressed tendon (9) is tensioned;

[0077] Step 9: the above manufacturing process is repeated, and after completion, the post-tensioned unbonded shared-tension prefabricated prestressed concrete frame structure system is completed.

[0078] The above is only an exemplary description of the present application, and it is obvious that the specific implementation of the present application is not limited by the above method, that is, the description is not limiting, and various improvements, changes or replacements can be easily made to the present application without departing from the method concept and technical solution of the present application, and these improvements and changes all belong to the protection scope of the present application.

Claims

1. A UHPC-connected post-tensioned unbonded co-tensioned prestressed concrete frame structure system, comprising a precast concrete upper column (1), a precast concrete lower column (2), a post-tensioned unbonded co-tensioned prestressed concrete composite beam (3), a UHPC node core area (4), and a composite slab (18). characterized in that The precast concrete upper column (1) is provided with upper longitudinal main reinforcement (5), the precast concrete lower column (2) is provided with lower longitudinal main reinforcement (6), the post-tensioned unbonded co-tensioned prestressed concrete composite beam (3) is provided with precast pre-tensioned prestressed concrete beam (7), beam composite layer (8) and post-tensioned unbonded prestressing tendons (9), the precast pre-tensioned prestressed concrete beam (7) is provided with ordinary steel bars (10) and pre-tensioned prestressing tendons (17), the beam composite layer (8) is provided with top continuous steel bars (11), and the composite slab (18) is composed of a precast concrete slab (19) and a slab composite layer (20) cast on the slab; The upper longitudinal main reinforcement (5) extends out of the bottom surface of the precast upper column (1) and is directly anchored in the core area (4) of the UHPC node; the lower longitudinal main reinforcement (6) extends out of the top surface of the precast lower column (2) and is directly anchored in the core area (4) of the UHPC node; the ordinary steel reinforcement (10) and the prestressed tendon (17) extend out of the end face of the precast prestressed concrete beam (7) and are directly anchored in the core area (4) of the UHPC node; The pre-tensioned prestressing tendons (17) include straight and broken line tendons, and the post-tensioned unbonded prestressing tendons (9) include straight, broken line, and curved tendons; Before pouring the beam composite layer (8), slab composite layer (20), and UHPC node core area (4), the post-tensioned unbonded co-tensioned prestressed concrete composite beam (3) is constructed and verified as a pre-tensioned prestressed concrete simply supported beam. After pouring the node core area (4), beam composite layer (8), and slab composite layer (20), when the concrete strength of the node and composite layer reaches the design requirements, the unbonded prestressing tendons (9) are tensioned. After tensioning, the construction stage verification is performed as a frame beam. After the prestress is established, the post-tensioned unbonded prestressing tendons (9) are calculated based on the effective prestress during construction verification and serviceability limit state verification. When performing the ultimate limit state verification, the stress increment should be considered. Under seismic load, the recovery performance of the unbonded prestressing tendons (9) on the node is considered. The post-tensioned unbonded prestressed tendons (9) are embedded in the precast pre-tensioned prestressed concrete beam (7) component, pass through the UHPC node core area (4) and extend beyond the UHPC node core area (4) at both ends. Clamps (15) and anchors (16) are fixedly installed at both ends respectively, with one end set on the outside of the column and the other end set in the beam composite layer. The core areas of the edge nodes, middle nodes and corner nodes of the co-tensioned prestressed concrete frame structure system are all UHPC node core areas (4); The stirrups in the core area (4) of the UHPC node are arranged according to the design requirements. The shear bearing capacity calculation of the core area considers the steel fibers in the UHPC as equivalent to horizontal stirrups and vertical longitudinal bars, and considers their contribution to the shear resistance of the core area of ​​the node. At the same time, the beneficial contribution of unbonded prestressed tendons to the shear resistance of the node is also considered. The construction method of the co-tensioned prestressed concrete frame structure system includes: The end of the precast prestressed concrete beam (7) is placed on the precast concrete lower column (2), and the precast concrete upper column (1) is hoisted to the top of the precast concrete lower column (2). The area enclosed between the precast prestressed concrete beam and the precast concrete lower and upper columns is the core area of ​​the UHPC node.

2. The UHPC-connected post-tensioned unbonded co-tensioned prestressed concrete frame structure system according to claim 1, characterized in that, The post-tensioned unbonded co-tensioned prestressed concrete composite beam (3) consists of a pre-tensioned prestressed concrete beam (7), a beam composite layer (8), and post-tensioned unbonded prestressing tendons (9); the composite slab (18) consists of a precast concrete slab (19) and a slab composite layer (20) cast on the slab.

3. The UHPC-connected post-tensioned unbonded co-tensioned prestressed concrete frame structure system according to claim 1, characterized in that, The bottom surface of the precast concrete upper column (1), the top surface of the precast concrete lower column (2), and the end face of the post-tensioned unbonded precast prestressed concrete composite beam (3) are all provided with recessed grooves or U-shaped grooves.

4. The UHPC-connected post-tensioned unbonded co-tensioned prestressed concrete frame structure system according to claim 1, characterized in that, The stirrups in the precast concrete upper column (1), precast concrete lower column (2), and post-tensioned unbonded precast prestressed concrete composite beam (3) are divided into a dense zone and an undense zone.

5. The UHPC-connected post-tensioned unbonded co-tensioned prestressed concrete frame structure system according to claim 1, characterized in that, The top surfaces of the precast prestressed concrete beam (7) and the precast concrete slab (19) are provided with a rough surface layer.

6. The construction method of the UHPC-connected post-tensioned unbonded co-tensioned prestressed concrete frame structure system according to any one of claims 1 to 5, characterized in that, Includes the following steps: Step 1: Construct precast concrete lower column (2), precast concrete upper column (1), precast prestressed concrete beam (7), and precast concrete slab (19); among them, the precast concrete lower column (2) and precast concrete upper column (1) need to reserve sufficient anchorage length for the longitudinal reinforcement extending into the core area (4) of the node; when precasting the prestressed concrete beam (7), the prestressed tendons (17) are first tensioned on the platform, and the unbonded prestressed tendons (9) are pre-embedded in the beam according to the design position, and sufficient structural length is reserved at both ends, and then the concrete is poured. When the concrete is cured to sufficient strength, the prestressed tendons (17) are released and sufficient anchorage length is reserved at the beam end; Step 2: After the precast components have been cured, hoist the precast concrete lower column (2) and install it on the foundation, and then install an appropriate number of stirrups on the extended longitudinal main reinforcement (6); Step 3: Hoist the precast prestressed concrete beam (7) to the top surface of the precast concrete lower column (2), so that the bottom surface of the precast prestressed concrete beam (7) is flush with the top surface of the precast concrete lower column (2), and place the end of the precast prestressed concrete beam (7) on the precast concrete lower column (2) and fix it with a support. Since the beam already has prestressing effect, it can be without support. Among them, the ordinary steel bars (10) and prestressed tendons (17) extending from the prestressed concrete beams (7) on both sides should be reasonably avoided in the core area of ​​the node and directly anchored or bent and anchored according to the structural requirements. Step 4: Hoist the precast concrete upper column (1) directly above the precast concrete lower column (2), and fix the precast concrete upper column (1) in the corresponding position with a reliable support (12). At this time, tie the stirrups installed in step 2 together with the column longitudinal reinforcement. The longitudinal reinforcements extending from the precast concrete upper and lower columns should be reasonably avoided in the core area of ​​the node and directly anchored. Step 5: Pass the top continuous steel bar (11) through the stirrups reserved in the beam composite layer area and the node core area (4) and tie it. Then tie the unbonded prestressed tendons (9) pre-embedded and extended in the pre-tensioned prestressed concrete beam (7) in the node core area according to the design position. Then pour the UHPC node core area (4) and set the formwork so that the UHPC will not enter the beam composite layer (8). Step 6: After the core area (4) of the UHPC node has been cured to a sufficient strength, the precast concrete slab, composite slab, double T slab or secondary beam is hoisted onto the precast prestressed concrete beam (7) and fixed. Step 7: Pour the beam composite layer (8) and slab composite layer (20); Step 8: After the concrete of the beam composite layer (8) and slab composite layer (20) has been cured to sufficient strength, the prestressing tendons (9) are tensioned. Step 9: Repeat the above production process to complete the unbonded prestressed concrete frame structure system.

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