CN220451075U - Post-tensioned unbonded prestressed concrete frame structure system connected by UHPC (ultra high pressure polyethylene) - Google Patents

Abstract

The utility model discloses a post-tensioned unbonded pre-stressed concrete frame structure system connected by UHPC, which comprises a pre-cast concrete upper column, a pre-cast concrete lower column, a post-tensioned unbonded pre-stressed concrete superposed beam, a UHPC node core area and a superposed plate. The upper longitudinal main ribs extend out of the bottom surface of the prefabricated upper column, the lower longitudinal main ribs extend out of the top surface of the prefabricated lower column, and the end surfaces of the common reinforcing steel bars extending out of the prefabricated concrete beam are directly anchored in the UHPC node core area. The structural system is convenient and quick to construct on site, improves the installation efficiency of the components, can greatly reduce the anchoring length of the reinforcing steel bars, greatly reduces the hooping consumption of the node core area, avoids crowding the reinforcing steel bars of the node core area, reduces the section height of the components, lightens the dead weight, improves the crack resistance and the bearing capacity of the components, and has no binding prestress rib to provide self-recovery performance for the structure, enhances the integrity and the structural toughness of the structure, thereby improving the earthquake resistance of the whole frame structure and reducing the repair cost after earthquake.

Description

Post-tensioned unbonded prestressed concrete frame structure system connected by UHPC (ultra high pressure polyethylene)

Technical Field

The utility model relates to the technical field of prefabricated prestressed assembly type building construction, in particular to a post-tensioned unbonded prestressed concrete frame structure system connected by UHPC.

Background

The cast-in-situ structure has the defects of low construction efficiency, high energy consumption and the like, and is difficult to adapt to the development requirements of building industrialization. The prefabricated building has become the development direction of building industrialization due to the advantages of high construction speed, industrialized production of components, field wet operation reduction, environmental pollution reduction and the like. Through years of development and popularization, prefabricated assembled concrete structures have been widely studied and used.

The prefabricated assembled concrete frame structure refers to a structure that beam column components are prefabricated in a prefabrication factory and transported to a construction site to be connected to form an integral structure. Compared with the cast-in-place concrete structure, the cast-in-place concrete structure has the advantages of high construction speed, easily guaranteed component quality, good quality, small environmental pollution, labor cost saving, a large number of templates and supports saving and the like, and is a structure form with very broad prospects. For the wet connection assembly type concrete frame structure, the node construction form which is easy to construct and effectively ensures the integrity is key to popularization and application. However, from the view of the past earthquake disasters, the assembled structure is seriously damaged in the earthquake, and the same earthquake-resistant performance as that of the cast-in-situ structure is difficult to achieve. In order to improve the integrity and reliability of the node connection of the assembled concrete frame and achieve and even exceed the earthquake-resistant performance of the cast-in-place concrete structure, a prestress technology and UHPC materials are introduced into the assembled structure.

The post-tensioned unbonded prestressed assembled concrete structure is formed by splicing prefabricated components together through tensioning prestressed tendons and has the characteristics of the post-tensioned unbonded prestressed concrete structure and an assembled structure. The internal stress generated by the prestress on the concrete section can partially or completely offset the section stress under the load, delay the occurrence of cracks and improve the rigidity of the component. During unloading, the crack can be partially or completely closed, and the elastic recovery performance of the structure is good. Meanwhile, the prestressed concrete can fully utilize the material strength of the prestressed tendons and the concrete, and lighten the dead weight of the structure. And the application of the prestress is beneficial to the improvement of the usability and the integrity of the assembled structure, and the application of the assembled structure in a large-span and heavy-load structure is promoted.

The UHPC has excellent bonding performance, and can greatly reduce the anchoring length of the steel bar and the prestressed steel bar; the strength is high, the hooping consumption of the node core area can be reduced, and the UHPC is used for the node core area, so that the structure is simple and the frame integrity is good. The pre-stress structure has excellent stress performance, and UHPC is applied to the node core area to form the pre-stress frame structure. The structure is subjected to intensive research, and is favorable for further popularization and application of the prefabricated prestressed concrete frame structure.

Disclosure of Invention

Aiming at the defects existing in the prior art and combining the excellent performance of UHPC, the utility model provides a post-tensioned unbonded prestressed concrete frame structure system connected by UHPC. The post-tensioning unbonded prestressed structure, the assembled structure and the superposed structure are combined, and the UHPC high-performance material is adopted, so that the aim of improving the earthquake resistance of the prefabricated assembled concrete frame structure is fulfilled.

The utility model has the advantages of mainly representing the two aspects of the connection technology of the precast concrete beam column components and the steel bar connection technology between the components. In the aspect of component connection technology, beam column components are connected through UHPC with excellent performance, a UHPC node core area is formed, and the anti-seismic fortification requirements of strong-node weak components are more easily realized, so that the ductility of beam column nodes is improved, and the anti-seismic performance of the whole frame structure is improved. In the aspect of the steel bar connection technology, the steel bars between the beam column components only need simple lap joint, and the lap joint length is small, so that the manufacturing time and the field installation time of the prefabricated components are greatly saved.

The technical problems solved by the utility model can be realized by adopting the following technical scheme:

the post-tensioned unbonded pre-stressed concrete frame structure system connected by UHPC comprises a pre-cast concrete upper column, a pre-cast concrete lower column, a post-tensioned unbonded pre-stressed concrete superposed beam, a UHPC node core area and a superposed plate;

the precast concrete is characterized in that an upper longitudinal main rib is arranged in an upper precast concrete column, a lower longitudinal main rib is arranged in a lower precast concrete column, a precast concrete beam, a beam lamination layer and a post-tensioning unbonded prestressed rib are arranged in a post-tensioning unbonded precast prestressed concrete lamination beam, a common reinforcing steel bar is arranged at the bottom of the precast concrete beam, a top through length reinforcing steel bar is arranged in the beam lamination layer, and the lamination plate consists of a precast concrete slab and a plate lamination layer poured on the plate.

The upper longitudinal main ribs extend out of the bottom surface of the prefabricated upper column and are directly anchored in the UHPC node core area, the lower longitudinal main ribs extend out of the top surface of the prefabricated lower column and are directly anchored in the UHPC node core area, and the common reinforcing steel bars extend out of the end surface of the prefabricated concrete beam and are directly anchored in the UHPC node core area.

The unbonded prestressed tendons comprise straight-line, broken-line or curved prestressed tendons;

the post-tensioned unbonded prestressed concrete composite beam is subjected to construction checking calculation according to a force transmission mode which is suitable for the setting of a common concrete simple beam and a support before a beam composite layer, a plate composite layer and a UHPC node core area are poured, after the node core area, the beam composite layer and the plate composite layer are poured, the concrete strength of the node and the composite layer meets the design requirement, the unbonded prestressed tendons are tensioned, the support is removed after the tensioning is completed, and the construction phase checking calculation is carried out according to the frame beam; after the prestress is established, the unbonded prestress rib is calculated by effective prestress in construction checking and normal use limit state checking, and the stress increment is considered in carrying out bearing capacity limit state checking.

Further, the post-tensioned unbonded prestressed concrete composite beam consists of a precast concrete beam, a beam composite layer and post-tensioned unbonded prestressed tendons; the laminated slab consists of a precast concrete slab and a slab laminated layer poured on the slab.

Further, the post-tensioned unbonded prestressed tendons are pre-buried in the precast concrete beam member and penetrate through the UHPC node core area, two ends of the post-tensioned unbonded prestressed tendons extend out of the UHPC node core area, two ends of the post-tensioned unbonded prestressed tendons are fixedly provided with clamps and anchors respectively, one ends of the post-tensioned unbonded prestressed tendons are arranged on the outer side of the column, and one ends of the post-tensioned unbonded prestressed tendons are arranged in the beam superposition layer.

Further, the bottom surface of the precast concrete upper column, the top surface of the precast concrete lower column and the end surface of the post-tensioned unbonded precast prestressed concrete superposed beam are all provided with inward concave grooves.

Further, the precast concrete upper column is fixed at the corresponding position by a reliable support.

Further, stirrups in the precast concrete upper column, the precast concrete lower column and the post-tensioned unbonded precast prestressed concrete superposed beam are divided into an encryption area and a non-encryption area, stirrups in a UHPC node core area are arranged according to design requirements, a shear-resistant bearing capacity in the core area is calculated according to a diagonal compression rod and a truss model, steel fibers in the UHPC are equivalent to horizontal stirrups and vertical longitudinal ribs, the contribution of the steel fibers to the shear resistance of the node core area is considered, and meanwhile the beneficial contribution of the unbonded prestressed ribs to the shear resistance of the node is considered.

Further, the precast concrete beam and the top surface of the precast concrete slab are provided with a fur layer. A post-tensioned unbonded prestressed concrete frame structure system for UHPC connection comprising the steps of:

step 1: manufacturing a precast concrete lower column, a precast concrete upper column, a precast concrete beam and a precast concrete slab; the prefabricated concrete lower column and the prefabricated concrete upper column extend out of the longitudinal ribs and are anchored into the node core area, and enough anchoring length is reserved; the common steel bars extending out of the precast concrete beam are anchored into the core area of the node, and enough anchoring length is reserved; pre-burying the prestressed tendons at the designed positions when manufacturing the precast concrete beam, and reserving enough lengths at two ends;

step 2: after the prefabricated part is maintained, hoisting a lower column of the prefabricated concrete, installing the lower column on a foundation, and installing a sufficient number of stirrups on a longitudinal main rib extending out of the lower column;

step 3: hoisting the precast concrete beam to the top surface of the precast concrete lower column, enabling the bottom surface of the precast concrete beam to be flush with the top surface of the precast concrete lower column, enabling the end part of the precast concrete beam to be placed on the precast concrete lower column, and fixing the precast concrete beam by using a support; the common reinforcing steel bars extending out of the precast concrete beams at the two sides are reasonably avoided and directly anchored in the node core area according to construction requirements;

step 4: hoisting the precast concrete upper column to the position right above the precast concrete lower column, fixing the precast concrete upper column at a corresponding position by a reliable support, and binding stirrups installed in the step 2 with column longitudinal ribs; wherein, the longitudinal ribs extending from the upper and lower columns of the precast concrete are reasonably avoided in the node core area and directly anchored;

step 5: the method comprises the steps of enabling a through-length reinforcing steel bar at the top to pass through a stirrup reserved in a beam overlapping layer area and a node core area and binding, binding pre-embedded and extending prestressed tendons in a precast concrete beam at the node core area according to a design position, pouring a UHPC node core area, and setting a template so that the UHPC cannot enter the beam overlapping layer;

step 6: after the UHPC node core area is cured to be of sufficient strength, hoisting the precast concrete slab to the precast concrete beam, and fixing;

step 7: pouring a beam lamination layer and a plate lamination layer;

step 8: after the concrete of the beam lamination layer and the plate lamination layer is cured to have enough strength, stretching the unbonded prestressed tendons;

step 9: repeating the manufacturing process to finish the post-tensioned unbonded precast prestressed concrete frame structure system.

Compared with the prior art, the utility model has the advantages that:

1. the utility model combines the prefabricated concrete structure with the post-tensioned unbonded prestressed structure, and improves the service performance of the structure, reduces the section height of the component, lightens the dead weight, improves the cracking resistance of the component and self-restores the advantages of the integral frame structure by combining the post-tensioned unbonded prestressed structure on the basis of utilizing the advantages of the prefabricated concrete structure, such as convenient and quick construction, good construction quality, energy conservation and environmental protection. The unbonded prestressed tendons provide self-resetting capability for the structure, enhance the integrity and the structural toughness of the structure and reduce the repair cost after earthquake.

2. The UHPC material with excellent performance is adopted and applied to the node core area, so that the reliable connection of the precast beam column components can be realized, the bearing capacity and the anti-seismic performance of the node can be improved, the anchoring length of the reinforcing steel bars and the prestressed reinforcing steel bars can be greatly reduced, the amount of the stirrups in the node core area can be remarkably reduced, the crowding of the reinforcing steel bars in the node core area is avoided, and the manufacturing, transporting and mounting efficiency of the precast beam column components is greatly improved.

Drawings

FIG. 1 is a schematic structural diagram of a UHPC-based precast prestressed concrete frame structure system of the present utility model

FIG. 2 is a schematic view of a two-span frame structure of the present utility model

FIG. 3 is a schematic view of a two-truss frame construction material according to the present utility model

FIG. 4 is a detailed view of the intermediate layer frame edge node construction of the present utility model

FIG. 5 is an isometric view of an intermediate layer frame edge node of the present utility model

FIG. 6 is a detailed view of the construction of nodes in the intermediate layer frame of the present utility model

FIG. 7 is an isometric view of a node in the middle layer frame of the present utility model

Detailed Description

So that the manner in which the features, objects, and advantages of the utility model can be better understood, a more particular description of the utility model, briefly summarized below, may be had by reference to the appended drawings.

As shown in fig. 1-7, the post-tensioned unbonded precast prestressed concrete frame structure system connected by UHPC comprises a precast concrete upper column 1, a precast concrete lower column 2, a post-tensioned unbonded precast prestressed concrete superposed beam 3, a UHPC node core area 4 and a superposed plate 17;

the precast concrete upper column 1 is internally provided with an upper longitudinal main rib 5, the precast concrete lower column 2 is internally provided with a lower longitudinal main rib 6, the post-tensioned unbonded precast prestressed concrete superposed beam 3 is internally provided with a precast concrete beam 7, a beam superposed layer 8 and a post-tensioned unbonded prestressed rib 9, the bottom of the precast concrete beam 7 is provided with a common reinforcing steel bar 10, the beam superposed layer 8 is internally provided with a top through-length reinforcing steel bar 11, and the superposed plate 17 consists of a precast concrete slab 18 and a slab superposed layer 19 poured on the slab.

The upper longitudinal main ribs 5 extend out of the bottom surface of the precast concrete upper column 1 and are directly anchored in the UHPC node core area 4, the lower longitudinal main ribs 6 extend out of the top surface of the precast concrete lower column 2 and are directly anchored in the UHPC node core area 4, and the common reinforcing steel bars 10 extend out of the end surface of the precast concrete beam 7 and are directly anchored in the UHPC node core area 4.

The post-tensioned unbonded prestressed tendons 9 comprise linear prestressed tendons, broken lines or curved prestressed tendons;

the post-tensioned unbonded prestressed concrete composite beam 3 is constructed and checked according to a force transmission mode which is suitable for the arrangement of a common concrete simple beam and a support before a beam composite layer 8, a plate composite layer 19 and a UHPC node core area 4 are poured, after the UHPC node core area 4, the beam composite layer 8 and the plate composite layer 19 are poured, the concrete strength of the node and the composite layer meets the design requirement, the post-tensioned unbonded prestressed tendons 9 are tensioned, the support is removed after the tensioning is completed, and the construction stage checking is performed according to the frame beam; after the establishment of the prestress, the post-tensioned unbonded prestress rib 9 is calculated by effective prestress in the construction checking calculation and the checking calculation of the normal use limit state, and the stress increment is considered in the carrying capacity limit state checking calculation.

The post-tensioned unbonded prestressed concrete composite beam 3 consists of a precast concrete beam 7, a beam composite layer 8 and post-tensioned unbonded prestressed tendons 9; the superimposed sheet 17 consists of precast concrete panels 18 and a sheet laminate 19 cast onto the panels.

The post-tensioned unbonded prestressed tendons 9 are pre-buried in the precast concrete beam 7 member and penetrate through the UHPC node core area 4, two ends of the post-tensioned unbonded prestressed tendons extend out of the UHPC node core area 4, two ends of the post-tensioned unbonded prestressed tendons are fixedly provided with clamps 15 and anchors 16 respectively, one ends of the post-tensioned unbonded prestressed tendons are arranged outside the column, and one ends of the post-tensioned unbonded prestressed tendons are arranged in the beam overlapping layer.

The bottom surface of the precast concrete upper column 1, the top surface of the precast concrete lower column 2 and the end surface of the post-tensioned unbonded precast prestressed concrete superposed beam 3 are all provided with inward concave grooves (U-shaped grooves can be arranged at the beam end, and structural shear steel bars can be arranged if necessary).

The precast concrete upper column 1 is fixed at a corresponding position by a reliable support 12.

The non-encrypted stirrups 13 in the precast concrete upper column 1, the precast concrete lower column 2 and the post-tensioned unbonded precast prestressed concrete superposed beam 3 are divided into an encrypted area and a non-encrypted area, the encrypted 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 a diagonal compression bar and truss model, the steel fibers in the UHPC are equivalent to horizontal stirrups and vertical longitudinal ribs, the contribution of the steel fibers to the shear resistance of the node core area is considered, and the shearing beneficial contribution of the unbonded prestressed ribs to the node core area is considered.

The precast concrete beams 7 and the top surfaces of the precast concrete panels 18 are provided with a fur layer.

A post-tensioned unbonded pre-stressed concrete frame structure system for UHPC connection, comprising the steps of:

step 1: manufacturing a precast concrete lower column 2, a precast concrete upper column 1, a precast concrete beam 7 and a precast concrete slab 18; the prefabricated concrete lower column 2 and the prefabricated concrete upper column 1 extend out of the longitudinal ribs and are anchored into the UHPC node core area 4, and enough anchoring length is reserved; the common steel bars 10 extending out of the precast concrete beams 7 are anchored into the UHPC node core area 4, and enough anchoring length is reserved; pre-burying post-tensioned unbonded prestressed tendons 9 at design positions when manufacturing the precast concrete beam 7, and reserving enough lengths at two ends;

step 2: after the prefabricated part is maintained, hoisting the precast concrete lower column 2 and installing the precast concrete lower column on a foundation, and installing a sufficient number of encryption stirrups 14 on the longitudinal main reinforcements 6 extending out of the lower column 2;

step 3: hoisting the precast concrete beam 7 to the top surface of the precast concrete lower column 2, enabling the bottom surface of the precast concrete beam 7 to be flush with the top surface of the precast concrete lower column 2, enabling the end part of the precast concrete beam 7 to be placed on the precast concrete lower column 2, and fixing the precast concrete lower column 2 by a support; the common steel bars 10 extending out of the precast concrete beams 7 at the two sides are reasonably avoided and directly anchored in the node core area according to the construction requirement;

step 4: hoisting the precast concrete upper column 1 to the position right above the precast concrete lower column 2, fixing the precast concrete upper column 1 at a corresponding position by using a reliable support 12, and binding the encrypted stirrups 14 installed in the step 2 with column longitudinal ribs; wherein, the longitudinal ribs extending from the upper and lower columns of the precast concrete are reasonably avoided in the node core area and directly anchored;

step 5: the method comprises the steps of enabling a top through-length reinforcing steel bar 11 to pass through a reserved non-encryption stirrup 13 in a beam overlapping layer area and a UHPC node core area 4 and binding, then binding a post-tensioned unbonded prestressed reinforcement 9 pre-embedded and extended in a precast concrete beam in the node core area according to a design position, pouring the UHPC node core area 4, and setting a template so that the UHPC cannot enter the beam overlapping layer 8;

step 6: after the UHPC node core area 4 is cured to have enough strength, hoisting a precast concrete panel (or a superimposed sheet, a double T plate and a secondary beam) 18 onto the precast concrete beam 7, and fixing;

step 7: pouring a beam lamination layer 8 and a plate lamination layer 19;

step 8: after the concrete of the beam lamination layer 8 and the plate lamination layer 19 is cured to have enough strength, the unbonded prestressed tendons 9 are tensioned;

step 9: repeating the manufacturing process to finish the post-tensioned unbonded precast prestressed concrete frame structure system.

While the utility model has been described above by way of example only, it will be apparent that the utility model is not limited to the particular embodiments described, i.e., it is not limited thereto, but is susceptible to various modifications, changes or substitutions without departing from the spirit and scope of the present utility model.

Claims (7)

1. The post-tensioned unbonded pre-stressed concrete frame structure system connected by UHPC comprises a pre-cast concrete upper column (1), a pre-cast concrete lower column (2), a post-tensioned unbonded pre-stressed concrete superposed beam (3), a UHPC node core area (4) and a superposed plate (17);

the concrete pile is characterized in that an upper longitudinal main rib (5) is arranged in a precast concrete upper column (1), a lower longitudinal main rib (6) is arranged in a precast concrete lower column (2), a precast concrete beam (7), a beam lamination layer (8) and a post-tensioning unbonded prestressed rib (9) are arranged in a post-tensioning unbonded precast prestressed concrete laminated beam (3), a common reinforcing steel bar (10) is arranged at the bottom of the precast concrete beam (7), a top through-length reinforcing steel bar (11) is arranged in the beam lamination layer (8), and a laminated slab (17) consists of a precast concrete slab (18) and a slab lamination layer (19) poured on the slab;

the upper longitudinal main ribs (5) extend out of the bottom surface of the precast concrete upper column (1) and are directly anchored in the UHPC node core area (4), the lower longitudinal main ribs (6) extend out of the top surface of the precast concrete lower column (2) and are directly anchored in the UHPC node core area (4), and the common reinforcing steel bars (10) extend out of the end surface of the precast concrete beam (7) and are directly anchored in the UHPC node core area (4);

the post-tensioned unbonded prestressed tendons (9) comprise linear, broken line or curve-shaped prestressed tendons;

after the UHPC node core area (4), the beam lamination layer (8) and the plate lamination layer (19) are poured, the concrete strength of the node and the lamination layer reach the design requirement, the post-tensioning unbonded prestressed tendons (9) are tensioned, and after the tensioning is completed, the support is removed.

2. The post-tensioned unbonded prestressed concrete frame structure system of a UHPC connection according to claim 1, characterized in that the post-tensioned unbonded prestressed concrete composite beam (3) consists of a precast concrete beam (7), a beam composite layer (8) and post-tensioned unbonded tendons (9); the laminated slab (17) consists of a precast concrete slab (18) and a slab laminated layer (19) poured on the slab.

3. The post-tensioned unbonded prestressed concrete frame structure system of the UHPC connection according to claim 1, wherein the post-tensioned unbonded prestressed tendons (9) are embedded in the precast concrete beam (7) and pass through the UHPC node core area (4) and extend out of the UHPC node core area (4) from both ends, the two ends of the post-tensioned unbonded prestressed tendons are fixedly provided with a clamp (15) and an anchor (16) respectively, one end of the post-tensioned unbonded prestressed tendons is arranged outside the column, and the other end of the post-tensioned unbonded tendons is arranged in the beam overlapping layer.

4. The post-tensioned unbonded prestressed concrete frame structure system of a UHPC connection according to claim 1, wherein the bottom surface of the precast concrete upper column (1), the top surface of the precast concrete lower column (2) and the end surface of the post-tensioned unbonded precast prestressed concrete composite beam (3) are provided with recessed grooves.

5. Post-tensioned unbonded pre-stressed concrete frame structure system with UHPC connection according to claim 1, characterized in that the pre-cast concrete upper column (1) is fixed in the corresponding position with a reliable support (12).

6. The post-tensioned unbonded pre-stressed concrete frame structure system of a UHPC connection according to claim 1, wherein the pre-cast concrete upper column (1), the pre-cast concrete lower column (2), the non-encrypted stirrups (13) in the post-tensioned unbonded pre-stressed concrete composite beam (3) and the encrypted stirrups (14) in the UHPC node core area (4) are arranged according to design requirements.

7. The UHPC-connected post-tensioned unbonded precast prestressed concrete frame structure system of claim 1, characterized in that the top surfaces of the precast concrete beams (7) and the precast concrete panels (18) are provided with a wool top.