High-strength reinforced concrete shear wall locally reinforced by UHPC (Ultra High Performance Concrete)
By partially adopting UHPC to enhance high-strength reinforced concrete structure in shear walls, the problem of large residual deformation and difficulty in repair caused by bending shear complex in high-rise buildings is solved, high lateral stiffness and bearing capacity are achieved, and the durability of the structure is improved.
Patent Information
- Application Number
- CN202421974458.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-08-15
- Publication Date
- 2025-06-13
- Estimated Expiration
- 2034-08-15
AI Technical Summary
Existing shear walls are prone to crushing and bending of the concealed column concrete due to the bending shearing complex in high-rise buildings, resulting in large residual deformation and difficult repair. At the same time, the strength level of high-strength steel bars and concrete is relatively low, making it difficult to exert its high performance.
The high-strength reinforced concrete shear wall is enhanced by locally using UHPC. Through the mutual cooperation between UHPC and high-strength steel bars, the lateral stiffness and bearing capacity of the shear wall are improved, and the residual deformation after earthquake is reduced. The high permeability of UHPC is used to reduce carbonization and steel corrosion, and the durability of the structure is improved.
The goal of small residual deformation after earthquake is achieved and easy to repair, while improving the lateral stiffness and bearing capacity of the structure, extending the service life of the structure.
Smart Images
Figure CN222976165U_ABST
Abstract
Description
Technical Field
[0001] The utility model belongs to the technical field of shear wall structures, and particularly relates to a high-strength reinforced concrete shear wall locally enhanced by UHPC. Background Technique
[0002] Shear walls have the advantages of reasonable structure, overall stability, large stiffness, and reasonable cost, and are widely used in high-rise and super-high-rise buildings. With the continuous increase of the height of modern buildings, the shear walls at the bottom of the building are often in a complex stress state under the combined action of bending and shear, which is likely to cause damage such as crushing of the concrete in the concealed column and buckling of the longitudinal reinforcement, resulting in large residual deformation and difficulties in repair. High-strength materials can be used to reduce the residual deformation of the structure after an earthquake due to their high elastic recovery performance, enabling the structure to have self-centering ability.
[0003] Compared with ordinary steel bars, high-strength steel bars have the advantages of high strength, good ductility, material saving, and economic rationality. However, the low concrete strength grade matched with high-strength steel bars will lead to the difficulty in giving full play to their high performance and high strength, and the strength loss is large after corrosion, reducing the seismic performance and durability.
[0004] Ordinary concrete has a low strength and a large porosity, and its internal steel bars are easily corroded in a harsh environment. When used in concealed columns, it is easily crushed, causing the yield of the longitudinal reinforcement and resulting in irreparable damage to the structure. Moreover, as the strength grade of ordinary concrete increases, its ductility decreases and it is prone to brittle failure, causing irreparable damage after an earthquake. The concept of UHPC was proposed in the 1990s. Compared with ordinary concrete, it increases the use of water reducers, highly reactive admixtures, steel fibers, etc., reduces the porosity, and improves the microstructure, making UHPC extremely excellent in toughness and fracture performance, and enabling the structure to have better reliability and reparability under earthquake action. Summary of the Invention
[0005] In order to overcome the deficiencies of the prior art, the purpose of the utility model is to provide a high-strength reinforced concrete shear wall locally enhanced by UHPC, which utilizes the mutual cooperation of UHPC and high-strength steel bars to improve the bearing capacity and lateral stiffness of the shear wall, reduce the residual deformation of the structure after an earthquake, and enable the structure to have self-centering ability; utilize the high anti-seepage performance of UHPC to reduce its own carbonation and the corrosion of internal steel bars, and improve the durability of the structure.
[0006] To achieve the object of the present utility model, the following technical solutions are adopted: A high-strength reinforced concrete shear wall locally strengthened with UHPC, including a shear wall web, concealed columns, longitudinal bars and stirrups arranged in the concealed columns, vertical distributed longitudinal bars of the wall, horizontal distributed bars, normal concrete and UHPC. Among them, the longitudinal bars and stirrups of the concealed columns, the vertical distributed longitudinal bars and horizontal distributed bars of the wall are all made of high-strength steel bars; the concrete in the concealed columns is UHPC, and the UHPC refers to ultra-high performance concrete with a compressive strength greater than 120 MPa, and the shear wall web is made of normal concrete.
[0007] Furthermore, the high-strength steel bars include steel bars with a yield strength above 500 MPa, steel wires, steel strands and fiber-reinforced composite bars.
[0008] Furthermore, distribution steel bars are arranged in the shear wall web, and the distribution steel bars include horizontal distributed bars and vertical distributed longitudinal bars. The two sides of the horizontal distributed bars extend into the concealed columns, and the ends adopt a 90° hook form.
[0009] Furthermore, stirrups for binding longitudinal bars are provided in the concealed columns. The stirrups and longitudinal bars are bound to form a rectangular steel cage, and the rectangular steel cage is cast with UHPC.
[0010] The positive and beneficial technical effects of the present utility model are as follows: For a high-strength reinforced concrete shear wall locally strengthened with UHPC of the present utility model, among which, the longitudinal bars, stirrups of the concealed columns, vertical distributed longitudinal bars and horizontal distributed bars of the web all adopt high-strength steel bars, and the concrete of the concealed columns adopts UHPC. The high-strength property of UHPC makes it difficult to be crushed, which can prevent the longitudinal bars of the concealed columns from buckling due to the loss of protection, give full play to the performance advantages of high-strength steel bars, enhance the lateral stiffness and bearing capacity of the structure, so as to achieve the purpose of small residual deformation and easy repair after an earthquake. The high ductility and relatively high tensile strength of UHPC result in fewer cracks under load, which can reduce steel consumption. By using the combination of UHPC and high-strength steel bars, the cross-sectional dimensions of the shear wall components can be reduced, the material cost can be saved, and the building use space can be increased. In natural environments and even harsh environments, the multi-crack cracking characteristics and high impermeability of UHPC reduce its own carbonation, and at the same time can provide anti-corrosion protection for the internal steel bars, improving the durability of the structure. Description of the Drawings
[0011] Figure 1 It is the main structural schematic diagram of the present utility model;
[0012] Figure 2 It is the structural schematic diagram of the A-A section of the present utility model;
[0013] Figure 3Comparison diagram of residual deformations of high-strength steel bar reinforced ordinary concrete shear walls, ordinary steel bar reinforced ordinary concrete shear walls, and high-strength steel bar shear walls locally strengthened with UHPC under horizontal cyclic loads. Detailed implementation manners
[0014] The following introduces the detailed implementation manners of the present utility model in combination with the accompanying drawings and embodiments:
[0015] A high-strength steel bar reinforced concrete shear wall locally strengthened with UHPC according to an embodiment of the present utility model, referring to Figure 1 and Figure 2 includes a shear wall web 1, a concealed column 2, longitudinal bars 3 and stirrups 4 arranged in the concealed column, vertical distributed bars 5 and horizontal distributed bars 6 of the web, ordinary concrete 7, and UHPC 8. Among them, the longitudinal bars 3 and stirrups 4 of the concealed column, the vertical distributed bars 5 and horizontal distributed bars 6 of the shear wall web use high-strength steel bars; only the concrete in the concealed column 2 is replaced with UHPC 8.
[0016] As a preferred embodiment, distribution bars are arranged in the shear wall web 1. The distribution bars include horizontal distributed bars 6 and vertical distributed bars 5. The two sides of the horizontal distributed bars 6 extend into the concealed column 2, and the ends adopt a 90° hook form.
[0017] As a preferred embodiment, stirrups 4 for tying longitudinal bars 3 are arranged in the concealed column 2. The stirrups 4 and the longitudinal bars 3 are tied to form a rectangular steel cage, and the rectangular steel cage is poured with UHPC 8.
[0018] As a preferred embodiment, first pour the UHPC 8 of the concealed column 2, construct a partition between the concealed column 2 and the web 1, remove the formwork of the concealed column 2 and remove the partition after 1 day, and then pour the ordinary concrete 7 of the web 1.
[0019] As a preferred embodiment, the high-strength steel bars include steel bars, steel wires, steel strands, and fiber reinforced composite material (FRP) bars with a yield strength above 500 MPa. The flexural bearing capacity of the component is mainly borne by the longitudinal bars 3 of the concealed column. Using high-strength steel bars here can utilize their high-strength characteristics and high ductility to improve the flexural bearing capacity of the component and reduce residual deformation. The vertical and horizontal components of the principal tensile stress of the shear wall web are mainly borne by the vertical distributed bars 5 and horizontal distributed bars 6 of the web respectively. Using high-strength steel bars here can control the development of diagonal cracks, increase the height of the compression zone of the concrete, delay the crushing of the concrete, thereby increasing the bearing capacity and lateral stiffness of the shear wall, making the structure less damaged and easy to repair. Using high-strength steel bars for the stirrups 4 of the concealed column can restrain the concrete in the compression zone, delay the crushing of the concrete in the compression zone, and improve the ductility of the shear wall.
[0020] As a preferred embodiment, the concrete of the concealed column 2 is UHPC8, and the concrete of the web 1 is ordinary concrete 7. The concealed column is the main body that bears bending moment and axial force. Using UHPC only for the concealed column can reduce the amount of UHPC, maximize the role of UHPC, improve economy, and the high-strength characteristics of UHPC make it difficult to be crushed, which can prevent the buckling of the longitudinal bars of the concealed column due to the loss of protection, give full play to the performance advantages of high-strength steel bars, enhance the lateral stiffness and bearing capacity of the structure, so as to achieve the purpose of small residual deformation and easy repair after an earthquake. In natural environments and even harsh environments, the multi-crack cracking characteristics and high impermeability of UHPC reduce its own carbonation, and at the same time can provide anti-corrosion protection for the internal steel bars, improving the durability of the structure. Embodiment
[0021] As Figure 1 , Figure 2 As shown in the figure, a high-strength reinforced concrete shear wall locally strengthened with UHPC includes a shear wall web 1, a concealed column 2, longitudinal bars 3 and stirrups 4 arranged in the concealed column, vertical distributed bars 5 of the web, horizontal distributed bars 6, ordinary concrete 7 and UHPC8. Among them, the longitudinal bars 3 and stirrups 4 of the concealed column, the vertical distributed bars 5 of the shear wall web and the horizontal distributed bars 6 use high-strength steel bars; the concrete in the concealed column 2 is UHPC8; the concrete of the web 1 is ordinary concrete 7.
[0022] As an embodiment, the high-strength steel bars use CRB600H steel bars. The longitudinal bars of the concealed column use CRB600H steel bars with a diameter of 12 mm, the stirrups of the concealed column use CRB600H steel bars with a diameter of 8 mm, and the vertical and horizontal distributed bars of the web use CRB600H steel bars with a diameter of 10 mm, with an ultimate tensile strength of 600 - 700 MPa and an elastic modulus of about 200 GPa.
[0023] As an embodiment, the UHPC8 is ultra-high performance concrete with a compressive strength greater than 120 MPa.
[0024] As an embodiment, the ordinary concrete 7 uses ordinary C30 concrete.
[0025] Figure 3 It is a comparison chart of the residual deformations of a high-strength reinforced concrete shear wall with ordinary concrete, a high-strength reinforced concrete shear wall with ordinary steel bars in ordinary concrete, and a high-strength reinforced concrete shear wall locally strengthened with UHPC under horizontal cyclic loading. All three undergo flexural-shear failure, and except for the different concrete grades of the concealed column and the different grades of the steel bars configured in the shear wall, the other conditions are the same. It can be seen from the comparison chart of the residual deformations that using UHPC for the concealed column and high-strength steel bars for the wall will significantly reduce the residual deformation of the shear wall under horizontal cyclic loading, achieving the purpose of small residual deformation and easy repair after an earthquake, and endowing the structure with self-centering ability.
Claims
1. A high-strength reinforced concrete shear wall partially reinforced with UHPC, characterized in that: It includes shear wall webs, concealed columns, longitudinal reinforcement and stirrups arranged in concealed columns, vertical longitudinal reinforcement of walls, horizontal distribution reinforcement, ordinary concrete and UHPC, wherein the longitudinal reinforcement and stirrups of concealed columns, vertical distribution reinforcement and horizontal distribution reinforcement of walls are all made of high-strength steel bars; the concrete in the concealed columns is UHPC, and the UHPC refers to ultra-high performance concrete with a compressive strength greater than 120MPa; the shear wall webs are made of ordinary concrete.
2. The high-strength reinforced concrete shear wall partially reinforced with UHPC according to claim 1, characterized in that: The high-strength steel bars include steel bars, steel wires, steel strands and fiber-reinforced composite material bars with a yield strength of more than 500 MPa.
3. The high-strength reinforced concrete shear wall partially reinforced with UHPC according to claim 1, characterized in that: Distributed steel bars are arranged in the web of the shear wall, and the distributed steel bars include horizontal distributed steel bars and vertical distributed longitudinal steel bars. Both sides of the horizontal distributed steel bars extend into concealed columns, and the ends are in the form of 90° hooks.
4. The high-strength reinforced concrete shear wall partially reinforced with UHPC according to claim 1, characterized in that: Stirrups for tying longitudinal reinforcements are arranged in the concealed column. The stirrups and the longitudinal reinforcements are tied together to form a rectangular reinforcement cage, and the rectangular reinforcement cage is cast with UHPC.