A UHPC connected post-tensioned slow-bonding co-tension prefabricated prestressed concrete opening beam frame structure and a design and construction method thereof

Abstract

The application discloses a UHPC connected post-tensioned slow-bonding co-tensioned prefabricated prestressed concrete open-hole beam frame structure system, which comprises a prefabricated concrete upper column, a prefabricated concrete lower column, a post-tensioned slow-bonding co-tensioned prefabricated prestressed concrete open-hole composite beam, a UHPC node core area and a composite slab. The upper longitudinal main reinforcement, the lower longitudinal main reinforcement, the common steel bars and the pre-tensioned prestressed reinforcement are directly anchored or bent and anchored in the UHPC node core area. The structure system not only is convenient and fast in on-site construction, improves the component installation efficiency, but also can greatly reduce the anchoring length of the steel bars, greatly reduce the amount of the stirrups in the node core area, avoid the congestion of the steel bars, 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. Meanwhile, the pre-tensioned prestress can realize the prefabricated beam with less support or without support construction, the post-tensioned slow-bonding reinforcement has good durability, is convenient in construction and solves the problem of the non-compactness of post-tensioned bonding grouting.

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 slow-bonding co-tension prefabricated prestressed concrete open-hole beam frame structure and its design and construction method. BACKGROUND

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

[0003] The prefabricated assembly type concrete frame structure refers to the structure in which the 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 structures, it has the advantages of fast construction speed, easy guarantee of component quality, good quality, small environmental pollution, saving of labor cost, and saving of a large amount of formwork and support, and is a structure form with very broad prospects. For wet connection assembly type concrete frame structures, the node construction form which is easy to construct and effectively guarantees the integrity is the key to the popularization and application. However, from the past earthquake disasters, the assembly type structure is severely 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) materials are introduced into the assembly type structure.

[0004] The post-tensioned slow-bonding co-tension prestressed assembly type concrete structure is formed by assembling the prefabricated ordinary concrete components and the prefabricated pre-tensioned prestressed components together to work together through tensioning the prestressed reinforcement, and has the characteristics of pre-tensioned prestressed, post-tensioned slow-bonding prestressed concrete structure and assembly type structure. The internal stress generated by the 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 the 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 integrity of the frame good. The prestressed structure has excellent stress performance, and the application of UHPC in the core area of the joint forms a prefabricated prestressed frame structure. Further research on this structure is beneficial to the further promotion and application of prefabricated prestressed concrete frame structures. SUMMARY

[0006] The purpose of the present application is to overcome the shortcomings of the prior art, combine the excellent performance of UHPC, and propose a UHPC connected post-tensioned slow-bonding co-tension prefabricated prestressed concrete open-hole beam frame structure and its design and construction method. It combines three traditional structures of pre-tensioned prestressed structure, post-tensioned slow-bonding prestressed structure, and assembled structure and composite structure, and uses UHPC high-performance materials, so as to improve the seismic performance of prefabricated assembled concrete frame structure.

[0007] The advantages of the present application mainly lie in the connection technology of prefabricated pre-tensioned prestressed concrete open-hole beam column components and the steel bar connection technology between components. In terms of component connection technology, the beam column components are connected through UHPC with excellent performance to form a UHPC joint core area, which is more easily to realize the seismic fortification requirement of strong joints and weak components, thereby improving the ductility of beam column joints and improving the seismic performance of the overall frame 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 on-site installation time. Therefore, the UHPC connected post-tensioned slow-bonding co-tension prefabricated prestressed concrete open-hole beam frame 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 slow-bonding co-tension prefabricated prestressed concrete open-hole beam frame structure, comprising a prefabricated concrete upper column, a prefabricated concrete lower column, a post-tensioned slow-bonding co-tension prefabricated prestressed concrete open-hole 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 and slowly-bonded co-tensioned prefabricated prestressed concrete open-hole composite beam is provided with prefabricated pre-tensioned prestressed concrete open-hole beam, beam composite layer and post-tensioned and slowly-bonded prestressed reinforcement, the prefabricated pre-tensioned prestressed concrete open-hole beam is provided with ordinary reinforcement and pre-tensioned prestressed reinforcement, and when necessary, hanging reinforcement or steel mesh can be arranged around the hole, and the steel mesh can also be welded steel mesh, the beam composite layer is provided with top longitudinal reinforcement, and the composite slab is composed of prefabricated concrete slab and 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, and the ordinary reinforcement and pre-tensioned prestressed reinforcement extends out of the end surface of the prefabricated pre-tensioned prestressed concrete open-hole beam and is directly anchored in the UHPC node core area;

[0012] The pre-tensioned prestressed reinforcement (17) comprises straight-line or broken-line reinforcement, and the post-tensioned bonded prestressed reinforcement (9) comprises straight-line, broken-line or curved-line reinforcement;

[0013] The post-tensioned and slowly-bonded co-tensioned prefabricated prestressed concrete open-hole composite beam (3) can also be a full prefabricated prestressed open-hole beam;

[0014] The post-tensioned bonded prestressed reinforcement (9) can be bonded, partially bonded or unbonded, and unbonded in the node core area;

[0015] The post-tensioned and slowly-bonded co-tensioned prefabricated prestressed concrete open-hole composite beam (3) is calculated according to the pre-tensioned prestressed concrete open-hole simple beam before pouring the beam composite layer (8), slab composite layer (20) and UHPC node core area (4), and after pouring the node core area (4), beam composite layer (8) and slab composite layer (20), the node and composite layer concrete strength reaches the design requirement, the post-tensioned bonded prestressed reinforcement (9) is tensioned, and after the tensioning is completed, the construction stage calculation is carried out according to the frame beam; the post-tensioned and slowly-bonded co-tensioned prefabricated prestressed concrete open-hole composite beam is different in the upper chord section at the hole and in the stress state before and after pouring the beam composite layer, slab composite layer and UHPC node core area, and the prefabricated pre-tensioned prestressed concrete open-hole beam hole upper and lower chord is calculated according to the construction; the post-tensioned and slowly-bonded prestressed reinforcement (9) is calculated according to the effective prestress after the prestress is established, the effective prestress is calculated for the node core area partially bonded and unbonded, and unbonded, the effective prestress is calculated in the normal use limit state, the stress increment of the unbonded reinforcement is considered in the ultimate bearing limit state, and the restoring performance provided by the unbonded reinforcement is considered under the earthquake load.

[0016] Further, the post-tensioned and slowly bonded co-tensioned prefabricated prestressed concrete open-hole composite beam is composed of a prefabricated pre-tensioned prestressed concrete open-hole beam, a beam composite layer and post-tensioned and slowly bonded prestressed reinforcement.

[0017] Further, the post-tensioned and slowly bonded prestressed reinforcement is embedded in the prefabricated pre-tensioned prestressed concrete open-hole beam component according to the designed position, passes through the UHPC node core area and extends out of the UHPC node core area at both ends, and is fixedly provided with a clamp and an anchor at both ends, one end being arranged outside the column and the other end being arranged in the beam composite layer.

[0018] 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 and slowly bonded co-tensioned prefabricated prestressed concrete open-hole composite beam are all provided with recessed grooves.

[0019] Further, the prefabricated concrete upper column is fixed at the corresponding position by reliable support.

[0020] Further, the stirrups in the prefabricated concrete upper column, the prefabricated concrete lower column and the post-tensioned and slowly bonded co-tensioned prefabricated prestressed concrete open-hole 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 the design requirement, the shear bearing capacity of the core area is calculated according to the inclined strut model, the steel fibers in the UHPC are equivalent to horizontal stirrups and vertical longitudinal reinforcement, the contribution of the steel fibers to the shear resistance of the node core area is considered, and the beneficial contribution of the slowly bonded prestressed reinforcement to the shear resistance of the node is considered.

[0021] Further, the top surface of the prefabricated pre-tensioned prestressed concrete open-hole beam and the prefabricated concrete plate is provided with a rough surface layer.

[0022] The application also provides a design method of the system, which comprises the following steps:

[0023] Step 1: the beam and the column are designed according to the existing specification and the invention patent;

[0024] Step 2: the strength of the upper chord and the lower chord at the hole of the prefabricated pre-tensioned prestressed concrete open-hole beam before pouring the beam composite layer, the plate composite layer and the UHPC node core area of the post-tensioned and slowly bonded co-tensioned prefabricated prestressed concrete open-hole composite beam is checked;

[0025] Step 3: the hole position in the post-tensioned and slowly bonded co-tensioned prefabricated prestressed concrete open-hole composite beam should be located in the 1 / 3 section of the span as much as possible, and when the hole position is located in the 1 / 3 section of the beam end, the distance from the edge of the hole close to the node to the inner edge of the node should be greater than 1.5 times the beam height.

[0026] A UHPC connected post-tensioned and slowly bonded co-tensioned prefabricated prestressed concrete open-hole beam frame structure comprises the following steps:

[0027] Step 1: making prefabricated concrete lower column, prefabricated concrete upper column, prefabricated pre-tensioned prestressed concrete opening beam, prefabricated concrete slab; wherein the prefabricated concrete lower column and the prefabricated concrete upper column extend the longitudinal reinforcement to anchor into the node core area and need to reserve sufficient anchoring length; when prefabricating the pre-tensioned prestressed concrete opening beam, the pre-tensioned prestressed reinforcement is tensioned on the pedestal, the post-tensioned slow-bonding prestressed reinforcement is pre-buried in the beam according to the design position, and sufficient length is reserved on both sides, 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 end of the beam;

[0028] 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;

[0029] Step 3: the prefabricated pre-tensioned prestressed concrete opening beam is hoisted to the top surface of the prefabricated concrete lower column, the bottom surface of the prefabricated pre-tensioned prestressed concrete opening beam is flush with the top surface of the prefabricated concrete lower column, the end of the prefabricated pre-tensioned prestressed concrete opening beam is placed on the prefabricated concrete lower column and fixed with support, and since the beam has the pre-tensioned prestressed action, support can also be omitted; wherein the ordinary reinforcement and pre-tensioned prestressed reinforcement extending from both sides of the pre-tensioned prestressed concrete opening beam are reasonably avoided and directly anchored or bent and anchored in the node core area according to the construction requirements;

[0030] Step 4: the prefabricated concrete upper column is hoisted to directly above the prefabricated concrete lower column, the prefabricated concrete upper column is fixed in the corresponding position with reliable support, at this time the stirrups 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 and directly anchored in the node core area;

[0031] Step 5: the top longitudinal reinforcement is passed through the stirrups reserved in the beam composite layer area and the node core area and is bound well, then the slow-bonding prestressed reinforcement pre-buried in the pre-tensioned prestressed concrete opening beam and extending therefrom is bound well in the node core area according to the design position, a sleeve is needed to be sleeved on the slow-bonding reinforcement for the non-bonding part of the node, then the UHPC node core area is poured, and the formwork is set to make the UHPC not enter the beam composite layer part;

[0032] Step 6: after the UHPC node core area is cured to sufficient strength, the prefabricated concrete flat slab (or composite slab, double T slab, secondary beam) is hoisted to the prefabricated prestressed concrete beam and is fixed;

[0033] Step 7: pouring the beam composite layer and the slab composite layer;

[0034] Step 8: after the beam composite layer and the slab composite layer are cured to sufficient strength, the slow-bonding prestressed reinforcement is tensioned;

[0035] Step 9: Repeat the above manufacturing process, and after completion, the frame structure system of the post-tensioned precast prestressed concrete opening beam with slow bonding is completed.

[0036] Compared with the prior art, the present application has the advantages that:

[0037] 1. The present application combines precast assembly type concrete structure, pre-tensioned prestressed structure and post-tensioned slow bonding prestressed structure together. On the basis of the advantages of precast assembly type structure, such as convenient and fast construction, good construction quality, energy saving and environmental protection, the post-tensioned slow bonding prestressed structure can improve the service performance of the structure, reduce the cross-sectional height of the component, reduce the self weight, improve the crack resistance and self-recovery performance of the component, thereby improving the seismic performance of the overall frame structure. The pre-tensioned prestressed structure can realize precast beam construction with less support or without support, and the post-tensioned slow bonding tendon has good durability and convenient construction, which solves the problem of non-compact grouting of post-tensioned bonding.

[0038] 2. The present application adopts UHPC material with excellent performance, which is applied in the node core area, so as to realize reliable connection of the precast beam and column component. Not only can the bearing capacity and seismic performance of the node be improved, but also the anchoring length of the steel bar and steel strand can be greatly reduced, and the amount of stirrup in the node core area can be significantly reduced, thereby avoiding the congestion of steel bars in the node core area, and greatly improving the production, transportation and installation efficiency of the precast beam and column component. BRIEF DESCRIPTION OF DRAWINGS

[0039] Figure 1 It is a structural schematic diagram of the precast prestressed concrete opening beam frame structure system based on UHPC of the present application

[0040] Figure 2 It is a reinforcement schematic diagram of a two-span frame structure of the present application

[0041] Figure 3 It is a material schematic diagram of a two-span frame structure of the present application

[0042] Figure 4 It is a detailed drawing of the edge node of the intermediate layer frame of the present application

[0043] Figure 5 It is an axonometric view of the edge node of the intermediate layer frame of the present application

[0044] Figure 6 It is a detailed drawing of the middle node of the intermediate layer frame of the present application

[0045] Figure 7 It is an axonometric view of the middle node of the intermediate layer frame of the present application DETAILED DESCRIPTION

[0046] In order to make the features, objectives and advantages of the present application more easily understood, the following further describes the present application in conjunction with the accompanying drawings and specific embodiments.

[0047] As shown in Figures 1-7 The UHPC connected post-tensioned slow-bonding co-tension prefabricated prestressed concrete open-hole beam frame structure system of the present application comprises a prefabricated concrete upper column (1), a prefabricated concrete lower column (2), a post-tensioned slow-bonding co-tension prefabricated prestressed concrete open-hole composite beam (3), a UHPC node core area (4), and a composite slab (18);

[0048] The prefabricated concrete upper column (1) is provided with an upper longitudinal main reinforcement (5), the prefabricated concrete lower column (2) is provided with a lower longitudinal main reinforcement (6), the post-tensioned slow-bonding co-tension prefabricated prestressed concrete open-hole composite beam (3) is provided with a prefabricated pre-tensioned prestressed concrete open-hole beam (7) and a beam composite layer (8) and a post-tensioned slow-bonding prestressed reinforcement (9), the prefabricated pre-tensioned prestressed concrete open-hole beam (7) is provided with ordinary reinforcement (10) and pre-tensioned prestressed reinforcement (17), the beam composite layer (8) is provided with a top-through steel bar (11), and the composite slab (18) is composed of a prefabricated concrete slab (19) and a slab composite layer (20) poured on the slab;

[0049] 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 open-hole beam (7) and are directly anchored in the UHPC node core area (4);

[0050] The pre-tensioned prestressed reinforcement (17) comprises a straight line or a folded line, and the post-tensioned slow-bonding prestressed reinforcement (9) comprises a straight line, a folded line, or a curved line;

[0051] The post-tensioned slow-bonding prestressed reinforcement (9) can be bonded, partially bonded, or unbonded in the node core area;

[0052] The post-tensioned slow-bonding co-tension prefabricated prestressed concrete composite beam (3) is calculated according to the pre-tensioned concrete open-hole simple beam before pouring the beam composite layer (8), the plate composite layer (20) and the UHPC node core area (4), and after pouring the node core area (4) and the beam composite layer (8), the plate composite layer (20), when the strength of the node and the composite layer concrete reaches the design requirement, the tension of the bonded prestressed tendon (9) is carried out, and after the tension is completed, the construction stage calculation is carried out according to the frame beam; the post-tensioned slow-bonding co-tension prefabricated prestressed concrete open-hole composite beam is different in the upper chord section at the hole opening before pouring the beam composite layer, the plate composite layer and the UHPC node core area and after pouring, and the stress state is also different, so the construction calculation of the upper and lower chord of the prefabricated pre-tensioned concrete open-hole beam at the hole opening should be carried out; after the prestress is established, the construction calculation of the post-tensioned slow-bonding prestressed tendon (9) is carried out by effective prestress, and for the node core area part with bonding and without bonding, without bonding, in the normal use limit state, the calculation is carried out according to the effective prestress, and in the ultimate bearing limit state, the stress increment of the unbonded tendon is considered; under the earthquake load, the restoring performance provided by the unbonded tendon is considered;

[0053] The post-tensioned slow-bonding co-tension prefabricated prestressed concrete open-hole composite beam (3) is composed of a prefabricated pre-tensioned concrete open-hole beam (7), a beam composite layer (8) and a post-tensioned slow-bonding prestressed tendon (9); the composite plate (18) is composed of a prefabricated concrete plate (19) and a plate composite layer (20) poured on the plate;

[0054] The post-tensioned slow-bonding prestressed tendon (9) is embedded in the prefabricated pre-tensioned concrete open-hole beam (7) according to the designed position, and passes through the UHPC node core area (4) and extends out of the UHPC node core area (4) at both ends, and clamps (15) and anchors (16) are respectively arranged at both ends, one end is arranged outside the column, and the other end is arranged in the beam composite layer;

[0055] 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 slow-bonding co-tension prefabricated prestressed concrete open-hole composite beam (3) are provided with recesses;

[0056] The prefabricated concrete upper column (1) is fixed in the corresponding position by reliable supports (12);

[0057] The stirrups (13) in the prefabricated concrete upper column (1), the prefabricated concrete lower column (2) and the post-tensioned slow-bonding co-tension prefabricated prestressed concrete open-hole composite beam (3) are divided into an encryption area and a non-encryption area, 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 inclined strut model, and the steel fibers in the UHPC are equivalent to horizontal stirrups and vertical longitudinal reinforcement, and the contribution of the steel fibers to the shear resistance of the node core area is considered, and the beneficial contribution of the slow-bonding prestressed reinforcement to the shear resistance of the node is also considered;

[0058] The top surface of the prefabricated pre-tensioned prestressed concrete open-hole beam (7) and the prefabricated concrete slab (19) is provided with a rough surface layer;

[0059] The seismic design of the system includes the following steps:

[0060] Step 1: The beam and column are designed according to existing specifications and invention patents;

[0061] Step 2: Check the strength of the upper and lower chord bars at the opening of the pre-tensioned prestressed concrete open-hole beam before pouring the beam composite layer, the slab composite layer and the UHPC node core area of the post-tensioned slow-bonding co-tension prefabricated prestressed concrete open-hole composite beam;

[0062] Step 3: The opening position in the post-tensioned slow-bonding co-tension prefabricated prestressed concrete open-hole composite beam should be located as far as possible in the 1 / 3 section of the span, and when located in the 1 / 3 section of the beam end, the distance from the edge of the hole near the node to the inner edge of the node should be greater than 1.5 times the beam height.

[0063] A UHPC connected post-tensioned slow-bonding co-tension prefabricated prestressed concrete open-hole beam frame structure, characterized by comprising the following steps:

[0064] Step 1: prefabricated concrete lower column (2), prefabricated concrete upper column (1), prefabricated pre-tensioned prestressed concrete open-hole beam (7), prefabricated concrete slab (19); wherein the prefabricated concrete lower column (2), the prefabricated concrete upper column (1) extends the longitudinal reinforcement anchor into the node core area (4) and needs to reserve enough anchoring length; when prefabricating the pre-tensioned prestressed concrete open-hole beam (7), the pre-tensioned prestressed reinforcement (17) is tensioned on the pedestal, the post-tensioned slow-bonding prestressed reinforcement (9) is pre-buried in the beam according to the design position, and enough length is reserved on both sides, 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;

[0065] Step 2: After the prefabricated components are cured, the prefabricated concrete lower column (2) is hoisted and installed on the foundation, and then a proper number of stirrups (14) are installed on the extended longitudinal reinforcement (6);

[0066] Step 3: Hoist the prefabricated pre-tensioned concrete open-hole beam (7) to the top surface of the prefabricated concrete lower column (2), make the bottom surface of the prefabricated pre-tensioned concrete open-hole beam (7) flush with the top surface of the prefabricated concrete lower column (2), make the end of the prefabricated pre-tensioned concrete open-hole beam (7) rest on the prefabricated concrete lower column (2), and fix it with supports. Since the beam already has a pre-tensioning effect, it can also be free of support. The ordinary steel bars (10) and pre-tensioned steel bars (17) extending from the pre-tensioned concrete open-hole beams (7) on both sides are reasonably avoided and directly anchored or bent and anchored in the node core area according to the construction requirements.

[0067] Step 4: Hoist the prefabricated concrete upper column (1) directly above the prefabricated concrete lower column (2), and fix the prefabricated concrete upper column (1) in the corresponding position with reliable supports (12). At this time, the stirrups (14) installed in step 2 are tied together with the column longitudinal bars. The longitudinal bars extending from the prefabricated concrete upper and lower columns are reasonably avoided and directly anchored in the node core area.

[0068] Step 5: Pass the top longitudinal steel bars (11) through the stirrups (13) reserved in the beam composite layer area and the node core area (4) and tie them together. Then, tie the design position of the embedded slow-bonding prestressed steel bars (9) extending from the pre-tensioned concrete open-hole beam (7) in the node core area. For the unbonded part of the node, a sleeve is needed on the slow-bonding steel bar. 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.

[0069] Step 6: After the UHPC node core area (4) is cured to sufficient strength, hoist the prefabricated concrete slab (or composite slab, double T slab, secondary beam) (19) to the prefabricated pre-tensioned concrete beam (7) and fix it.

[0070] Step 7: Pour the beam composite layer (8) and the slab composite layer (20).

[0071] Step 8: After the beam composite layer (8) and the slab composite layer (20) are cured to sufficient strength, tension the slow-bonding prestressed steel bars (9).

[0072] Step 9: Repeat the above manufacturing process to complete the post-tensioned slow-bonding co-tensioned prefabricated pre-tensioned concrete open-hole beam frame structure system.

[0073] The above description is merely an exemplary description of the present application. It is obvious that the specific implementation of the present application is not limited to the above manner. That is, the description is not limiting. Without departing from the method concept and technical solution of the present application, the present application can be easily improved, changed or replaced, and these improvements and changes are within the protection scope of the present application.

Claims

1. A UHPC connected post-tensioned and slow-bonded co-tensioned precast prestressed concrete open-hole beam frame structure system, comprising a precast concrete upper column (1), a precast concrete lower column (2), a post-tensioned and slow-bonded co-tensioned precast prestressed concrete open-hole 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 an upper longitudinal main reinforcement (5), the precast concrete lower column (2) is provided with a lower longitudinal main reinforcement (6), the post-tensioned and slow-bonded co-tensioned precast prestressed concrete open-hole composite beam (3) is provided with a precast pre-tensioned prestressed concrete open-hole beam (7), a beam composite layer (8) and a post-tensioned and slow-bonded prestressed reinforcement, the precast pre-tensioned prestressed concrete open-hole beam (7) is provided with ordinary reinforcement (10) and pre-tensioned prestressed reinforcement, and a hanging reinforcement (21) or a steel mesh (22) is arranged around the hole, the steel mesh is a welded steel mesh, the beam composite layer (8) is provided with a top longitudinal reinforcement (11), and the composite slab (18) is composed of a precast concrete slab (19) and a slab composite layer (20) poured 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 UHPC node core area (4), the lower longitudinal main reinforcement (6) extends out of the top surface of the precast 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 extend out of the end surface of the precast pre-tensioned prestressed concrete open-hole beam (7) and are directly anchored in the UHPC node core area (4) ; The pre-tensioned prestressed reinforcement includes straight or folded line reinforcement, and the post-tensioned and slow-bonded prestressed reinforcement includes straight, folded line or curved line reinforcement; The post-tensioned and slow-bonded prestressed reinforcement is bonded, partially bonded, unbonded or unbonded in the node core area; The post-tensioned and slow-bonded co-tensioned precast prestressed concrete open-hole composite beam (3) is calculated according to the pre-tensioned prestressed concrete open-hole simply supported beam before pouring the beam composite layer (8), the slab composite layer (20) and the UHPC node core area (4), and after pouring the node core area (4) and the beam composite layer (8) and the slab composite layer (20), the node and the composite layer concrete strength reaches the design requirement, the post-tensioned and slow-bonded prestressed reinforcement is tensioned, and after the tensioning is completed, the construction stage calculation is carried out according to the frame beam; the post-tensioned and slow-bonded co-tensioned precast prestressed concrete open-hole composite beam is different in the section of the upper chord at the hole and the stress state before and after pouring the beam composite layer, the slab composite layer and the UHPC node core area, and the precast pre-tensioned prestressed concrete open-hole beam hole upper and lower chord should be calculated; the post-tensioned and slow-bonded prestressed reinforcement is calculated according to the effective prestress after the prestress is established, the node core area is partially bonded or unbonded, and the unbonded reinforcement is calculated according to the effective prestress in the normal use limit state, the stress increment of the unbonded reinforcement is considered in the ultimate bearing limit state, and the restoring performance provided by the unbonded reinforcement is considered under the seismic load. The post-tensioned and slowly-bonded prestressed tendon is embedded in the prefabricated pre-tensioned prestressed concrete open-hole beam (7) component according to the design position, passes through the UHPC node core area (4) and extends out of the UHPC node core area (4) at both ends, and is fixedly provided 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. The edge node, the middle node and the corner node core area of the post-tensioned and slowly-bonded and co-tensioned prefabricated prestressed concrete open-hole beam frame structure system are all UHPC node core areas (4). The stirrups in the UHPC node core area (4) are arranged according to design requirements, and the calculation of the shear bearing capacity of the core area considers that the steel fibers in the UHPC are equivalent to horizontal stirrups and vertical longitudinal reinforcement, and considers the contribution of the steel fibers to the shear resistance of the node core area, and also considers the beneficial contribution of the slowly-bonded prestressed tendon to the shear resistance of the node. The construction method of the post-tensioned and slowly-bonded and co-tensioned prefabricated prestressed concrete open-hole beam frame structure system comprises the following steps: The end of the prefabricated pre-tensioned prestressed concrete open-hole beam (7) is placed on the prefabricated concrete lower column (2), the prefabricated concrete upper column (1) is hoisted to directly above the prefabricated concrete lower column (2), and the area enclosed between the prefabricated pre-tensioned prestressed concrete open-hole beam and the prefabricated concrete lower column and upper column is the UHPC node core area.

2. The UHPC connected post-tensioned slow-bonded co-tensioned precast prestressed concrete perforated beam frame structural system according to claim 1, characterized in that, The post-tensioned and slowly-bonded and co-tensioned prefabricated prestressed concrete open-hole composite beam (3) is composed of a prefabricated pre-tensioned prestressed concrete open-hole beam (7), a beam composite layer (8) and a post-tensioned and slowly-bonded prestressed tendon; and the composite slab (18) is composed of a prefabricated concrete slab (19) and a slab composite layer (20) poured on the slab.

3. The UHPC connected post-tensioned slow-bonded co-tensioned precast prestressed concrete perforated beam frame structural system according to claim 1, characterized in that, 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 and slowly-bonded and co-tensioned prefabricated prestressed concrete open-hole composite beam (3) are all provided with recessed grooves.

4. The UHPC connected post-tensioned slow-bonded co-tensioned precast prestressed concrete open-web beam framed structural system according to claim 1, characterized in that, The stirrups in the prefabricated concrete upper column (1), the prefabricated concrete lower column (2) and the post-tensioned and slowly-bonded and co-tensioned prefabricated prestressed concrete open-hole composite beam (3) are divided into dense areas and non-dense areas.

5. The UHPC connected post-tensioned slow-bonded co-tensioned precast prestressed concrete open-web beam framed structural system according to claim 1, characterized in that, The top surface of the prefabricated pre-tensioned prestressed concrete open-hole beam (7) and the prefabricated concrete slab (19) is provided with a rough surface layer.

6. A design method of the UHPC connected post-tensioned slow-bonded co-tensioned precast prestressed concrete open-web beam frame structural system according to claim 1, characterized in that: The hole position in the beam should be located as far as possible in the 1 / 3 section of the span, and when located in the 1 / 3 section of the beam end, the distance from the edge of the hole near the node to the inner edge of the node should be greater than 1.5 times the height of the beam.

7. The construction method of the UHPC connected post-tensioned slow-bonding and co-tensioning precast prestressed concrete open-hole beam frame structure according to any one of claims 1 to 5, characterized in that, The method comprises the following steps: Step 1: prefabricate a prefabricated concrete lower column (2), a prefabricated concrete upper column (1), a prefabricated pre-tensioned prestressed concrete open-hole beam (7) and a prefabricated concrete slab (19); wherein the prefabricated concrete lower column (2) and the prefabricated concrete upper column (1) need to reserve sufficient anchoring length for the anchoring of the longitudinal reinforcement into the node core area (4); when prefabricating the prestressed concrete open-hole beam (7), the pre-tensioned prestressed tendon is tensioned on the pedestal, the post-tensioned and slowly-bonded prestressed tendon is embedded in the beam according to the design position and sufficient length is reserved on both sides, then the concrete is poured, the pre-tensioned prestressed tendon is released when the concrete is cured to sufficient strength, and sufficient anchoring length is reserved at the beam end; Step 2: After the curing of the precast component is completed, hoist the precast concrete lower column (2) and install it on the foundation, and then install a proper number of stirrups on the protruding longitudinal main reinforcement (6); Step 3: Hoist the precast pretensioned prestressed concrete hole beam (7) to the top surface of the precast concrete lower column (2), make the bottom surface of the precast pretensioned prestressed concrete hole beam (7) flush with the top surface of the precast concrete lower column (2), make the end of the precast pretensioned prestressed concrete hole beam (7) rest on the precast concrete lower column (2), and fix it with a support, and since there is a pretensioning effect in the beam, the support can be omitted; wherein the ordinary steel bars (10) and pretensioning reinforcement bars protruding from the two side pretensioned prestressed concrete hole beams (7) are reasonably avoided and directly anchored or bent and anchored in the node core area according to the construction requirements; Step 4: Hoist the precast concrete upper column (1) to 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, the stirrups installed in step 2 are tied together with the column longitudinal reinforcement; wherein the longitudinal reinforcement protruding from the precast concrete upper and lower columns is reasonably avoided and directly anchored in the node core area; Step 5: Pass the top longitudinal steel bar (11) through the stirrups reserved in the beam composite layer area and the node core area (4) and tie them well, then tie the embedded and protruding slow-bonding prestressed reinforcement bars in the pretensioned prestressed concrete hole beam (7) in the node core area according to the design position, and for the unbonded part of the node, a sleeve is needed on the slow-bonding reinforcement bar, 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; Step 6: After the UHPC node core area (4) is cured to sufficient strength, hoist the precast concrete slabs, composite slabs, double T slabs or secondary beams to the precast prestressed concrete hole beam (7) and fix them; Step 7: Pour the beam composite layer (8) and the slab composite layer (20); Step 8: After the beam composite layer (8) and the slab composite layer (20) are cured to sufficient strength, tension the slow-bonding prestressed reinforcement bars; Step 9: Repeat the above manufacturing process to complete the post-tensioned slow-bonding co-tensioned precast prestressed concrete hole beam frame structure system.

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