Members configured with ultra-high strength prestressed tendons and high strength steel

Abstract

The utility model discloses a kind of component of combined configuration of superhigh-strength prestressed tendon and high-strength steel bar, and the component includes: component frame and the component body of component frame wrapping;Component frame includes: multiple high-strength steel bars and multiple superhigh-strength prestressed tendons.Multiple high-strength steel bars extend along the length direction of component body and are respectively arranged at the top and bottom of component body;Multiple superhigh-strength prestressed tendons are arranged in the inside of component body along the length direction of component body;Wherein, the yield strength standard value of high-strength steel bar is 600Mpa-700Mpa, and the ultimate strength standard value of superhigh-strength prestressed steel bar is 2160Mpa-2500Mpa.The component uses superhigh-strength prestressed tendon and high-strength steel bar combination, so that component body large crack width limit value is consistent with ordinary reinforced concrete structure.Compared with the component of existing prestressed tendon, reinforcement ratio is lower under the same crack limit value, and structure seismicity is better, to effectively control crack width to ensure the durability and seismic performance of component.

Description

Technical Field

[0001] This utility model belongs to the field of civil engineering technology, specifically relating to a component using a combination of ultra-high strength prestressed tendons and high strength steel bars. Background Technology

[0002] High-strength steel and prestressed application technology have both been listed as ten key new technologies for the construction industry to be promoted and applied. Their application in concrete components is of great significance for effectively utilizing natural resources, reducing carbon emissions, reducing material consumption, and improving the safety performance of reinforced concrete components.

[0003] For members employing prestressed tendons, the durability of the prestressed tendons has a significant impact on the performance of the member; therefore, the durability guarantee rate of prestressed tendons should be higher than that of ordinary steel reinforcement. The classification of crack control levels in prestressed concrete members is based on factors such as the functional requirements of the member, environmental category, and the duration of load application. However, considering that the current national standard "Standard for Design of Concrete Structures" GB / T 50010 has relatively strict crack control level classifications, and the significant gradient from Level II (generally requiring no cracks) to Level III (allowing cracks of 0.2 mm), the overall reinforcement ratio of the member is relatively large to meet the crack limit requirements, which is not conducive to the seismic ductility design of prestressed concrete members and the widespread application of prestressing technology.

[0004] The information disclosed in this background section is intended only to enhance the understanding of the overall background of this utility model and should not be construed as an admission or in any way implying that the information constitutes prior art known to those skilled in the art. Utility Model Content

[0005] The purpose of this invention is to provide a component that uses a combination of ultra-high strength prestressed tendons and high strength steel bars, which has a lower reinforcement ratio and better seismic ductility under the same crack limit.

[0006] To achieve the above objectives, a specific embodiment of this utility model provides the following technical solution: A component using a combination of ultra-high strength prestressed tendons and high-strength steel bars, comprising: a component frame and a component body enclosing the component frame; the component frame includes: multiple high-strength steel bars and multiple ultra-high strength prestressed tendons. The multiple high-strength steel bars extend along the length of the component body and are respectively disposed at the top and bottom of the component body; the multiple ultra-high strength prestressed tendons are arranged inside the component body along the length of the component body; wherein, the standard value of the yield strength of the high-strength steel bars is 600 MPa-700 MPa, and the standard value of the ultimate strength of the ultra-high strength prestressed tendons is 2160 MPa-2500 MPa.

[0007] In one or more embodiments of this utility model, the component frame further includes a plurality of rectangular stirrups, a plurality of waist reinforcements, and a plurality of tie reinforcements. The plurality of rectangular stirrups are arranged at intervals along the length direction of the component body; each waist reinforcement extends along the length direction of the component body, and the plurality of waist reinforcements are respectively fixedly connected to the middle of the left and right edges of the rectangular stirrups; each tie reinforcement extends along the width direction of the component body, and the plurality of tie reinforcements are fixedly arranged at the middle of the left and right edges of the rectangular stirrups and connected to the waist reinforcements on both sides.

[0008] In one or more embodiments of this utility model, the plurality of high-strength steel bars are respectively fixedly connected to the upper and lower edges of the rectangular stirrup.

[0009] In one or more embodiments of this utility model, the plurality of high-strength steel bars are evenly spaced at the upper and lower edges of the rectangular stirrup.

[0010] In one or more embodiments of this utility model, a waist bar is provided at the middle of the left and right edges of the rectangular stirrup, and the multiple waist bars are arranged at intervals along the height direction of the rectangular stirrup.

[0011] In one or more embodiments of this utility model, a plurality of tie bars are spaced apart on the rectangular stirrups along the height direction, and at most one of two adjacent rectangular stirrups is provided with a tie bar. Another specific embodiment of this utility model provides a component crack resistance design method, which includes: establishing different levels of crack resistance standards for the component; determining the environmental category of the application location of the component; selecting ultra-high strength prestressed tendons and obtaining the corrosion resistance performance parameters of the ultra-high strength prestressed tendons to determine the applicable crack resistance level of the component; and obtaining the crack width limit of the component using the ultra-high strength prestressed tendons based on the applicable crack resistance level of the component and the environmental category.

[0012] In one or more embodiments of this utility model, the ultra-high strength prestressed tendon has a minimum stress corrosion test time of 2 hours and a median of 5 hours under the first or second level crack resistance standard; and a minimum stress corrosion test time of 5 hours and a median of 8 hours under the third level crack resistance standard. The stress corrosion test is performed in accordance with the provisions of the current national standard GB / T 21839 "Test Methods for Steel for Prestressed Concrete".

[0013] In one or more embodiments of this utility model, the environmental category adopts the provisions of the national standard "Design Standard for Concrete Structures" GB / T 50010.

[0014] In one or more embodiments of this utility model, the crack control level and maximum crack width limit parameters of the component crack resistance standard are as follows:

[0015] For components used in Class I environments with an annual average relative humidity of less than 60%, the maximum crack width limit can be the value in parentheses.

[0016] Compared with existing technologies, the component of this invention, which employs a combination of ultra-high strength prestressed tendons and high-strength steel bars, achieves a maximum crack width limit in the cross-section of the component that is consistent with or close to that of ordinary reinforced concrete structures. Under the same crack limit, it requires a lower reinforcement ratio and exhibits better seismic ductility, thereby effectively controlling crack width to ensure the durability and structural ductility of the component. This crack-resistant design method allows for the determination of the component's crack resistance performance during the design phase, based on the relevant performance parameters of the ultra-high strength prestressed tendons and environmental conditions. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 This is a cross-sectional schematic diagram of a component using a combination of ultra-high strength prestressed tendons and high strength steel bars in one embodiment of the present invention; Figure 2 This is a schematic diagram of the component frame in one embodiment of the present invention.

[0019] Explanation of key figure labels: 1-Frame structure, 11-High-strength steel bars, 12-Ultra-high-strength prestressed tendons, 13-Rectangular stirrups, 14-Waist bars, 15-Tie bars, 2-Structure body. Detailed Implementation

[0020] To enable those skilled in the art to better understand the technical solutions of this utility model, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, and not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort should fall within the protection scope of this utility model.

[0021] like Figure 1-2As shown, an embodiment of this utility model discloses a component using a combination of ultra-high strength prestressed tendons and high-strength steel bars. The component includes a component frame 1 and a component body 2 enclosing the component frame 1, wherein the component body 2 is made of concrete. The component frame 1 includes multiple high-strength steel bars 11 and multiple ultra-high strength prestressed tendons 12. The multiple high-strength steel bars 11 extend along the length of the component body 2 and are respectively disposed at the top and bottom of the component body 2. The multiple ultra-high strength prestressed tendons 12 are arranged inside the component body 2 along the length of the component body 2. The standard value of the yield strength of the high-strength steel bars 11 is 600 MPa-700 MPa, and the standard value of the ultimate strength of the ultra-high strength prestressed tendons is 2160 MPa-2500 MPa.

[0022] This component employs a combination of ultra-high strength prestressed tendons 12 and high-strength steel bars 11, ensuring that the maximum crack width limit of the component's main body 2 is consistent with or close to that of ordinary reinforced concrete structures. Compared to existing components using prestressed tendons, it has a lower reinforcement ratio and better seismic resistance under the same crack limit, thereby effectively controlling the crack width to ensure the component's durability and seismic performance.

[0023] In one implementation, such as Figure 2 As shown, the component frame 1 also includes multiple rectangular stirrups 13, multiple web reinforcements 14, and multiple tie rods 15. The multiple rectangular stirrups 13 are arranged sequentially at intervals along the length of the component body 2. Each web reinforcement 14 extends along the length of the component body 2 and is fixedly connected to the middle and lower parts of the left and right edges of the rectangular stirrups 13, respectively. Each tie rod 15 extends along the width of the component body 2. The multiple tie rods 15 are fixedly arranged at the middle and lower parts of the left and right edges of the rectangular stirrups 13 and connected to the web reinforcements 14 on both sides.

[0024] Preferably, multiple high-strength steel bars 11 are fixedly connected to the upper and lower edges of the rectangular stirrup 13. The multiple high-strength steel bars 11 are evenly spaced along the upper and lower edges of the rectangular stirrup 13 to ensure the strength of the upper and lower parts of the frame 1. Further, a web reinforcement 14 is provided at the center of both the left and right edges of the rectangular stirrup 13, and multiple web reinforcements 14 are arranged sequentially at intervals along the height direction of the rectangular stirrup 13. Multiple tie bars 15 are spaced along the height direction of the rectangular stirrup 13, and at most one of two adjacent rectangular stirrups 13 is provided with a tie bar 15. Here, the middle part of the rectangular stirrup 13 includes the middle position, the upper middle position, and the lower middle position. With this design, the overall strength of component frame 1 is higher, and compared with existing components using prestressed steel bars, it uses fewer types of steel bars. At the same time, it can have a maximum crack width limit similar to that of ordinary reinforced concrete structures, reducing costs while also taking into account durability and seismic resistance.

[0025] Another embodiment of this utility model provides a method for designing crack resistance of components, which includes the following steps: establishing crack resistance standards for different levels of components; determining the environmental category of the application location of the component; selecting ultra-high strength prestressed tendons and obtaining the corrosion resistance performance parameters of the ultra-high strength prestressed tendons to determine the applicable crack resistance level of the component; and obtaining the crack width limit of the component using ultra-high strength prestressed tendons based on the applicable crack resistance level and environmental category of the component.

[0026] For prestressed structural members, the durability of prestressing tendons has a significant impact on structural performance. Therefore, the durability guarantee rate of ultra-high strength prestressing tendons should be higher than that of ordinary steel bars. Especially when structural members face complex environmental conditions, simply improving the material quality and thickness of the concrete cover is often insufficient to guarantee the design service life. For critical components such as prestressed steel strands that are difficult to inspect and maintain during use, ultra-high stress corrosion resistant and slow-bonding prestressed steel bars can be used to better adapt to the durability and crack resistance design of the structural members and improve their seismic ductility.

[0027] Specifically, the classification standards for the crack resistance levels of components are as follows: For ultra-high strength prestressed tendons, under the first or second level crack resistance standards, the minimum stress corrosion test time is greater than or equal to 2 hours, and the median is greater than or equal to 5 hours; under the third level crack resistance standards, the minimum stress corrosion test time is greater than or equal to 5 hours, and the median is greater than or equal to 8 hours. The stress corrosion test shall be carried out in accordance with the provisions of the current national standard "Test Methods for Steel for Prestressed Concrete" GB / T 21839.

[0028] Among them, Level 1 crack resistance is defined as: components that are strictly required to be free of cracks. When calculated according to the standard load combination, the concrete at the tension edge of the component should not generate tensile stress.

[0029] Class I crack resistance (Level II) refers to structural members that are generally required to be free of cracks. When calculating according to the standard load combination, the tensile stress in the concrete at the tension edge of the member should not exceed the standard value of the concrete tensile strength.

[0030] Class II crack resistance refers to structural members for which cracks are generally permissible. When calculating based on the standard load combination and considering the long-term effects, the maximum crack width of the member should not exceed the maximum crack width value specified in the table. When calculating based on the permanent combination in the load standard, the tensile stress in the concrete at the tension edge of the member should not exceed the standard value of the concrete tensile strength.

[0031] Level 3 crack resistance: Components where cracks are permissible. When calculating according to the standard load combination and considering the long-term effects, the maximum crack width of the component should not exceed the maximum crack width limit specified in the table. In Level 3 crack resistance, for components in Class I environments with an annual average relative humidity of less than 60%, the maximum crack width limit can be the value in parentheses.

[0032] Specifically, the environmental category adopts the provisions of the national standard "Standard for Design of Concrete Structures" GB / T 50010. The crack control level and maximum crack width limit parameters for the component crack resistance standard are as follows:

[0033] This crack-resistant design method allows for the determination of crack width limits for prestressed concrete structures during the design phase, based on the performance parameters of the ultra-high-strength prestressed tendons and environmental conditions. This enables a determination of whether the structure using the ultra-high-strength prestressed tendons meets the corresponding crack resistance requirements. Furthermore, this method enhances the seismic design of prestressed concrete structures and the application of prestressing technology.

[0034] In summary, this component employs a combination of ultra-high-strength prestressed tendons and high-strength steel reinforcement, resulting in a maximum crack width limit on the cross-section that is consistent with or close to that of ordinary reinforced concrete structures. Compared to existing components using prestressed tendons, it exhibits a lower reinforcement ratio and better seismic ductility under the same crack limit, effectively controlling crack width to ensure the component's durability and structural ductility. This crack-resistant design method allows for the determination of the component's crack resistance during the design phase, based on the relevant performance parameters of the ultra-high-strength prestressed tendons and environmental conditions, thereby enhancing the component's seismic ductility design and the application of prestressing technology.

[0035] It will be apparent to those skilled in the art that this invention is not limited to the details of the exemplary embodiments described above, and that it can be implemented in other specific forms without departing from the spirit or essential characteristics of this invention. Therefore, the embodiments should be considered illustrative and non-limiting in all respects, and the scope of this invention is defined by the appended claims rather than the foregoing description. Thus, it is intended that all variations falling within the meaning and scope of equivalents of the claims be included within this invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

[0036] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A component employing a combination of ultra-high strength prestressed tendons and high-strength steel bars, characterized in that, include: The component frame and the component body that encloses the component frame; The component frame includes: Multiple high-strength steel bars extend along the length of the component body and are respectively disposed at the top and bottom of the component body; and Multiple ultra-high strength prestressing tendons are arranged inside the component body along the length direction of the component body; The standard value of the yield strength of the high-strength steel bar is 600Mpa-700Mpa, and the standard value of the ultimate strength of the ultra-high-strength prestressed tendon is 2160Mpa-2500Mpa.

2. The component using a combination of ultra-high strength prestressed tendons and high-strength steel bars as described in claim 1, characterized in that, The component frame also includes: Multiple rectangular stirrups are arranged at intervals along the length of the component body; Multiple reinforcing bars, each extending along the length of the component body, are respectively fixedly connected to the middle of the left and right edges of the rectangular stirrup; and Multiple tie rods, each extending along the width of the component body, are fixedly disposed at the middle of the left and right edges of the rectangular stirrup and connected to the waist reinforcement on both sides.

3. The component using a combination of ultra-high strength prestressed tendons and high strength steel bars according to claim 2, characterized in that, The multiple high-strength steel bars are respectively fixedly connected to the upper and lower edges of the rectangular stirrup.

4. The component using a combination of ultra-high strength prestressed tendons and high strength steel bars according to claim 2, characterized in that, The multiple high-strength steel bars are evenly spaced at the upper and lower edges of the rectangular stirrup.

5. The component using a combination of ultra-high strength prestressed tendons and high strength steel bars according to claim 2, characterized in that, The rectangular stirrup has a waist reinforcement at the middle of its left and right edges, and the multiple waist reinforcements are arranged at intervals along the height direction of the rectangular stirrup.

6. The component using a combination of ultra-high strength prestressed tendons and high-strength steel bars according to claim 2, characterized in that, Multiple tie rods are spaced apart on the rectangular stirrups along the height direction, and at most one of two adjacent rectangular stirrups is provided with a tie rod.

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