A large spatial span post-tensioned prestressed beam and construction method
By setting up arched prestressed pipelines in large-span prestressed concrete beams and tensile steel strands, compressive stress is introduced to offset external tensile stress, the problem of excessive internal tensile stress of concrete in large-span prestressed concrete beams is solved, and efficient load bearing and durability of the structure are achieved.
Patent Information
- Application Number
- CN202510082854.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-01-20
- Publication Date
- 2025-04-04
AI Technical Summary
In the construction of large-span prestressed concrete beams, the external tensile stress introduced by the single-layer tensioning method leads to a significant increase in the internal tensile stress of the concrete, increasing the risk of cracks and affecting the durability and load-bearing capacity of the structure.
The large space span post-tension method is designed to design prestressed beams. By setting the first arch and the second arch prestressed pipeline inside the beam body, and tensioning the steel strands inside it are introduced to introduce compressive stress to offset the external tensile stress and optimize the stress distribution.
Effectively reduce the tensile stress level inside the concrete, reduce the risk of cracks, and improve the load-bearing capacity and durability of the structure.
Smart Images
Figure CN119754482A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to the technical field of building engineering construction, and in particular to a large-span post-tensioned prestressed beam and a construction method. Background Art
[0002] Large spatial span prestressed concrete beams refer to prestressed concrete beams used in structures such as bridges and buildings with large spans. Their "large spatial span" usually refers to a span exceeding a certain length (the specific value varies depending on the type of project and the technical level, generally tens of meters or even hundreds of meters), and their spans are significantly larger than those of ordinary concrete beams.
[0003] Prestressed concrete technology is its core, which applies prestress to steel bars or strands before pouring concrete, thereby improving the tensile strength and crack resistance of concrete. When the beam is loaded, the prestress can offset part of the tensile stress caused by the load, thereby improving its bearing capacity and service life.
[0004] In the existing construction process of prestressed concrete beams with large spatial spans, single-layer tensioning is generally used to apply prestress. However, when faced with large spatial spans, this method will introduce large external tensile stress. Due to the relatively low tensile strength of concrete materials, this external tensile stress will lead to a significant increase in the tensile stress level inside the concrete, thereby increasing the risk of cracks, especially on the surface of the beam. The formation of cracks not only affects the durability of the structure, but may also affect its bearing capacity and safety. Summary of the invention
[0005] The present application provides a large spatial span post-tensioned prestressed beam and a construction method, which has the effect of reducing the tensile stress level inside the concrete and reducing the risk of cracks.
[0006] The present application provides a large spatial span post-tensioned prestressed beam and a construction method, which adopts the following technical solutions: A large-span post-tensioned prestressed beam and a construction method, wherein the large-span post-tensioned prestressed beam comprises a cast beam body, a first arched prestressed pipe is arranged inside the cast beam body and along its own length direction, a plurality of the first arched prestressed pipes are arranged at equal intervals along the width direction of the cast beam body, a first steel strand is arranged inside the first arched prestressed pipe of the cast beam body; two ends of the first steel strand respectively penetrate two ends of the first arched prestressed pipe of the cast beam body and are connected to a first tensioning structure; A second arched prestressed pipe is arranged inside the casting beam body and along its own length direction, and a plurality of the second arched prestressed pipes are arranged at equal intervals along the width direction of the casting beam body, and a second steel strand is arranged inside the second arched prestressed pipe of the casting beam body; two ends of the second steel strand respectively penetrate through two ends of the second arched prestressed pipe of the casting beam body and are connected to a second tensioning structure; The center of the arc segment corresponding to the second arched prestressed pipe coincides with the center of the arc segment corresponding to the first arched prestressed pipe, and the second arched prestressed pipe is located inside the first arched prestressed pipe.
[0007] By adopting the above technical scheme, the design of the post-tensioned prestressed beam with a large spatial span adopts a first arched prestressed pipe and a second arched prestressed pipe; the setting of the two arched prestressed pipes helps to optimize the stress distribution inside the beam body, thereby enhancing the stability and bearing capacity of the structure; specifically, this design can effectively bear and reasonably distribute the loads generated by the upper load and its own weight; in actual construction, the first steel strand and the second steel strand are tensioned through their respective arched prestressed pipes, thereby introducing compressive stress in the concrete; this compressive stress can effectively offset the tensile stress applied from the outside, thereby reducing the tensile stress level inside the concrete and reducing the risk of cracks; through such a design and layout, the prestressed beam is improved in terms of bearing performance and durability.
[0008] Preferably, a pre-buried reinforcement piece is provided between the first steel strand and the second steel strand.
[0009] By adopting the above technical solution, the setting of embedded reinforcement parts significantly enhances the rigidity inside the beam body, thereby effectively limiting the relative displacement between the various parts; this design measure not only improves the overall bending resistance of the structure, but also enhances the shear resistance, ensuring the stability and durability of the structure under stress; by optimizing the stress transfer path, the introduction of embedded reinforcement parts improves the performance of the beam body and reduces the potential risk of deformation and damage.
[0010] Preferably, the embedded reinforcement member includes a plurality of reinforcement shafts arranged along the width direction of the cast beam body, the plurality of reinforcement shafts are parallel to each other, and the reinforcement shafts are alternately arranged up and down along an arc track.
[0011] By adopting the above technical solution, the setting of the reinforcement shaft in the embedded reinforcement member is intended to improve the overall stiffness and bending resistance between the first steel strand and the second steel strand; the design of the reinforcement shaft significantly enhances the anti-lateral displacement ability and overall stability of the structure through a specific geometric shape and arrangement; the reinforcement shaft is arranged alternately up and down along the arc track, so that the beam body can effectively disperse and transfer stresses in different parts under stress; this design helps to achieve a more uniform force distribution, thereby reducing the risk of local damage caused by concentrated force; through this optimized stress transfer mechanism, the durability and reliability of the structure are further improved.
[0012] Preferably, the embedded reinforcement member further comprises an expanded metal mesh, and the expanded metal mesh passes through the surface of the reinforcement shaft alternately up and down.
[0013] By adopting the above technical solutions, the combined design of the expanded metal mesh not only significantly improves the performance and safety of the structure, but also shows significant advantages in terms of economy and construction efficiency; this comprehensive reinforcement solution is suitable for a variety of engineering structures subjected to complex loads, and can effectively meet the mechanical requirements under different working conditions; by integrating superior material properties and innovative design concepts, the solution achieves the best balance between structural enhancement and economic benefits, ensuring the convenience of the construction process and the reliability of subsequent use.
[0014] Preferably, a plurality of reinforcement protrusions are evenly arranged on the mesh surface of the extended metal mesh, and the cross-section of the reinforcement protrusions is a polygonal structure.
[0015] By adopting the above technical solution, the design of polygonal reinforcement protrusions provides a larger surface area and increases the contact points with concrete, thereby effectively improving the bonding strength between the two; as the contact surface and contact area increase, the friction force also increases, thereby significantly improving the bonding effect with concrete; this design helps to more effectively transfer the externally applied load to the concrete, improve its bearing capacity, and reduce the risk of local fatigue and cracking; the larger contact area not only makes the load applied to the structure more evenly distributed, but also reduces the local stress concentration phenomenon; this optimized load distribution helps to improve the mechanical properties of the entire component and enhance the overall stability and durability of the structure; by comprehensively considering the bonding strength and load transfer mechanism, the design provides a more reliable solution for engineering applications under complex working conditions.
[0016] Preferably, the construction method of the above-mentioned large spatial span post-tensioned prestressed beam comprises the following construction steps: S1. Construction preparation; Review the design drawings and construction plans in detail to ensure that all materials and specifications meet the requirements; purchase high-strength steel strands, concrete, expanded metal mesh, reinforcement bosses and other construction materials and conduct quality inspections; and inspect concrete mixers, prestressing equipment, tensioning equipment and other construction tools to ensure they are functioning properly; S2. Formwork construction; Construct formwork for beams to ensure that their size and shape meet design requirements and are reinforced to withstand the deadweight of the concrete and construction loads; S3. Prestressed pipe installation; Install the first arched prestressed pipe and the second arched prestressed pipe along the predetermined position in the template to ensure that their positions and quantities meet the design requirements; and inspect the installed first arched prestressed pipe and the second arched prestressed pipe to ensure that there is no deviation and they are firmly fixed; S4. Laying of expanded metal mesh and reinforcement blocks; According to the fixing effect of the template in S2, a pre-buried reinforcement member is installed in the area between the first arched prestressed pipe and the second arched prestressed pipe; S5. Concrete pouring; Mix concrete according to the designed mix ratio to ensure that its strength and workability meet the engineering requirements; pour concrete in the formwork to avoid segregation and voids during the pouring process; vibrate the concrete with a vibrator to eliminate bubbles and ensure that the concrete is dense; S6. Maintenance and demoulding; After the concrete is poured, it is cured as required to ensure its strength growth and crack resistance. After the concrete reaches the designed strength, the formwork is removed and the surface is treated; S7. Tension prestressing; The prestressed steel strands are tensioned according to the design requirements and prestressed using tensioning equipment; after tensioning, anchoring is performed to ensure that the prestressed steel strands are stable in force; S8. Inspection and acceptance; The bearing capacity and deformation of the beam are tested to ensure that they meet the design standards; after completing various tests, a final acceptance is carried out to ensure that the construction quality meets the requirements.
[0017] By adopting the above technical scheme, the construction method of the post-tensioned prestressed beam with a large spatial span sequentially includes construction preparation, formwork construction, prestressed pipe installation, laying of extended metal mesh and reinforcement blocks, concrete pouring, maintenance and demolding, prestressing, testing and acceptance; it can effectively enhance the bearing capacity of the beam to adapt to the application requirements of larger spans; and reduce structural deformation, improve rigidity, and ensure a good user experience.
[0018] Preferably, in S4, the embedded reinforcement member includes a reinforcement shaft, and the reinforcement shaft is first installed so that the reinforcement shaft extends and is alternately distributed along the long side direction of the prestressed beam.
[0019] By adopting the above technical solution, the distribution of the reinforcement axis along the long side direction can enhance the shear resistance of the beam, improve the seismic performance and ensure the safety of the structure.
[0020] Preferably, in S4, after the reinforcement shaft is installed, the extended metal mesh is alternately passed through the surface of the reinforcement shaft up and down, and then one end of the extended metal mesh is fixed to the reinforcement shaft at the endmost end, and the other end is fixed to the reinforcement shaft at the other end after adjusting the tension.
[0021] By adopting the above technical solution, the expanded metal mesh is stably fixed on the reinforcement shaft, and the expanded metal mesh is tensioned so that the expanded metal mesh generates a contraction force on the reinforcement shaft, thereby having a good tensile resistance effect.
[0022] Preferably, in S7, the prestressed steel strands in S1 are passed through the first arched prestressed pipe and the second arched prestressed pipe, and then the first arched prestressed pipe is tensioned first and then the second arched prestressed pipe is tensioned in sequence.
[0023] By adopting the above technical solution, tensioning the first arched prestressed pipe first can provide the necessary support and stability, creating good conditions for the subsequent tensioning of the second arched prestressed pipe, thereby improving the stability of the overall structure; tensioning in sequence can better control the transmission of force, thereby reducing uneven force and stress concentration, and improving the safety and durability of the structure.
[0024] Preferably, the tensioning ratio of the prestressed steel strand in the first arched prestressed pipe is greater than the tensioning ratio of the prestressed steel strand in the second arched prestressed pipe.
[0025] By adopting the above technical solution, the second arched prestressed pipe is located on the inner side of the first arched prestressed pipe; the larger tension force will significantly improve the bending strength of the first arched prestressed pipe, so that it can more effectively resist deformation and damage when subjected to external loads; at the same time, since the second arched prestressed pipe is located on the inner side, it can help provide additional rigidity and further enhance the stability of the overall component.
[0026] In summary, this application has the following beneficial effects: 1. The design of the large-span post-tensioned prestressed beam adopts the first arched prestressed pipe and the second arched prestressed pipe; the setting of the two arched prestressed pipes helps to optimize the stress distribution inside the beam body, thereby enhancing the stability and bearing capacity of the structure; specifically, this design can effectively bear and reasonably distribute the loads generated by the upper load and its own weight; in actual construction, the first steel strand and the second steel strand are tensioned through their respective arched prestressed pipes, thereby introducing compressive stress in the concrete; this compressive stress can effectively offset the tensile stress applied from the outside, thereby reducing the tensile stress level inside the concrete and reducing the risk of cracks; through such design and layout, the prestressed beam is improved in terms of bearing performance and durability.
[0027] 2. The construction method of the post-tensioned prestressed beam with a large spatial span includes construction preparation, formwork construction, prestressed pipe installation, laying of extended metal mesh and reinforcement blocks, concrete pouring, maintenance and demolding, prestressing, testing and acceptance. It can effectively enhance the bearing capacity of the beam to meet the application requirements of larger spans, reduce structural deformation, improve rigidity, and ensure a good user experience. BRIEF DESCRIPTION OF THE DRAWINGS
[0028] Figure 1 Schematic diagram of the overall structure of the cast beam body in this embodiment; Figure 2 is a schematic diagram of the explosion structure between the cast beam body, the first steel strand and the second steel strand in this embodiment; Figure 3 Schematic diagram of the internal structure of the embedded reinforcement member in this embodiment; Figure 4 is a schematic diagram of the connection structure between the extended metal mesh and the reinforcement protrusion block in this embodiment; Figure 5 Schematic diagram of the construction process of the large spatial span post-tensioned prestressed beam in this embodiment; Explanation of the reference numerals: 1. Cast beam; 2. First steel strand; 3. Second steel strand; 4. Embedded reinforcement member; 41. Reinforcement shaft; 42. Extended metal mesh; 43. Reinforcement protrusion. DETAILED DESCRIPTION
[0029] The present application is further described in detail below in conjunction with the accompanying drawings. It is necessary to point out here that the following specific implementation methods are only used to further illustrate the present application and cannot be understood as limiting the scope of protection of the present application. Technical personnel in this field can make some non-essential improvements and adjustments to the present application based on the above application content. Example
[0030] The present invention discloses a large spatial span post-tensioned prestressed beam and a construction method thereof. Figure 1 and Figure 2 As shown, the large spatial span post-tensioned prestressed beam includes a cast beam body 1, a first arched prestressed pipe is arranged inside the cast beam body 1 and along its own length direction, a plurality of first arched prestressed pipes are arranged at equal intervals along the width direction of the cast beam body 1, and a first steel strand 2 is arranged inside the first arched prestressed pipe of the cast beam body 1; both ends of the first steel strand 2 are respectively passed through the two ends of the first arched prestressed pipe of the cast beam body 1 and are connected to a first tensioning structure.
[0031] like Figure 1 and Figure 2 As shown, a second arched prestressed pipe is arranged inside the cast beam body 1 and along its own length direction, and a plurality of second arched prestressed pipes are arranged at equal intervals along the width direction of the cast beam body 1, and a second steel strand 3 is arranged inside the second arched prestressed pipe of the cast beam body 1; both ends of the second steel strand 3 respectively pass through the two ends of the second arched prestressed pipe of the cast beam body 1 and are connected to a second tensioning structure.
[0032] like Figure 1 and Figure 2 As shown, the arch structure can effectively disperse the load; by setting the first arch prestressed pipe and the second arch prestressed pipe, the stress distribution inside the beam body can be optimized; this design enables the structure to better bear and distribute the load from the upper part and its own weight; the first steel strand 2 and the second steel strand 3 are tensioned through their channels respectively, so that the steel bars generate compressive stress in the concrete; this compressive stress can offset the tensile stress applied from the outside, thereby reducing the tensile stress of the concrete and reducing the probability of crack formation.
[0033] like Figure 1 and Figure 2 As shown, the center of the arc segment corresponding to the second arched prestressed pipe coincides with the center of the arc segment corresponding to the first arched prestressed pipe, and the second arched prestressed pipe is located on the inner side of the first arched prestressed pipe. The second arched prestressed pipe is arranged on the inner side of the first arched prestressed pipe, and its layout design utilizes the synergistic effect of two groups of steel bars; through this layout, the bearing capacity and overall stability of the entire beam body can be effectively improved; the post-tensioning method can be tensioned after the concrete is cured, which provides greater flexibility for construction and reduces potential risks during construction.
[0034] like Figure 2 and Figure 3As shown, a pre-embedded reinforcement member 4 is arranged between the first steel strand 2 and the second steel strand 3. The pre-embedded reinforcement member 4 includes a plurality of reinforcement shafts 41 arranged along the width direction of the cast beam body 1. By arranging the reinforcement shafts 41 along the width direction, the bending stiffness of the beam body can be significantly improved, and the bearing capacity of the beam body with a large spatial span under heavy load conditions can be enhanced; the plurality of reinforcement shafts 41 are parallel to each other, and the reinforcement shafts 41 are alternately arranged up and down along an arc track.
[0035] like Figure 2 and Figure 3 As shown, the setting of the reinforcement shaft 41 in the embedded reinforcement member 4 is intended to enhance the overall stiffness and bending resistance between the first steel strand 2 and the second steel strand 3; the design of the reinforcement shaft 41 improves the lateral displacement resistance and integrity of the structure through a certain geometric shape and arrangement.
[0036] like Figure 3 As shown, the reinforcement shafts 41 are alternately arranged up and down along the arc track, so that when the beam body is subjected to force, the stress in different parts can be effectively dispersed and transmitted; this design can achieve a more uniform force distribution and help avoid local damage caused by concentrated force.
[0037] like Figure 3 As shown, the design of the reinforcement shaft 41 increases the rigidity inside the beam body, thereby limiting the relative displacement between the various parts and improving the overall bending and shearing resistance of the structure.
[0038] like Figure 3 As shown, the embedded reinforcement member 4 also includes an extended metal mesh 42, which passes through the surface of the reinforcement shaft 41 alternately up and down. The function of the extended metal mesh 42 is to provide additional tensile and shear strength; by alternately passing the extended metal mesh 42 near the reinforcement shaft 41, the load can be effectively distributed evenly to the entire structure to avoid concentrated stress in local areas; the combination of the extended metal mesh 42 and concrete can enhance the bonding strength between the two; the porous design of the metal mesh surface can be better embedded in the concrete during pouring, thereby improving the integrity and bonding strength of the structure.
[0039] like Figure 3 As shown, when the prestressed beam structure is subjected to dynamic load or vibration, the extended metal mesh 42 can provide a certain energy absorption capacity, reduce damage to concrete, and improve seismic performance; the setting of the metal mesh can significantly increase the tensile strength of concrete, especially in high stress areas, and can effectively prevent concrete from cracking.
[0040] like Figure 3As shown, the expanded metal mesh 42 is made of one of carbon steel, stainless steel and alloy steel; applying the expanded metal mesh 42 made of carbon steel, stainless steel or alloy steel to the prestressed beam can significantly improve the tensile strength and durability of the beam and improve the performance of the overall structure; according to specific engineering requirements, selecting appropriate materials can achieve economic benefits and durability while ensuring structural safety.
[0041] like Figure 3 and Figure 4 As shown, a plurality of reinforcing protrusions 43 are evenly arranged on the mesh surface of the extended metal mesh 42. The cross-section of the reinforcing protrusions 43 is a triangular structure. The triangular reinforcing protrusions 43 provide a larger surface area, and the number of bonding points with the concrete is increased, which can effectively improve the bonding strength between the two. The larger the contact surface, the greater the contact area, and the greater the friction force, thereby improving the bonding effect with the concrete. This helps to better transfer the externally applied load to the concrete, reducing local fatigue and cracking. A larger contact area means that the load applied to the structure can be more evenly distributed, reducing local stress concentration, thereby improving the mechanical properties of the entire component.
[0042] like Figure 3 and Figure 4 As shown, the reinforced protrusions 43 can reduce the risk of peeling due to repeated loads or temperature and humidity changes by increasing the bonding area with the concrete, and enhance the stability of the extended metal mesh 42 during long-term service; the triangular cross-section can effectively resist shear force, provide better structural stability, and reduce deformation of the mesh surface caused by load.
[0043] like Figure 3 and Figure 4 As shown, by providing a reinforcing protrusion 43 with a triangular cross-section on the extended metal mesh 42, not only can the contact area with the concrete be significantly increased, but also the bonding strength and durability can be improved, thereby improving the overall performance and safety of the structure.
[0044] like Figure 5 As shown, the construction method of the large spatial span post-tensioned prestressed beam comprises the following construction steps: S1. Construction preparation; Review the design drawings and construction plans in detail to ensure that all materials and specifications meet the requirements; purchase high-strength steel strands, concrete, expanded metal mesh 42, reinforcement convex blocks 43 and other construction materials, and conduct quality inspections; and inspect concrete mixers, prestressing equipment, tensioning equipment and other construction tools to ensure that they are operating normally; S2. Formwork construction; Construct formwork for beams to ensure that their size and shape meet design requirements and are reinforced to withstand the deadweight of the concrete and construction loads; S3. Prestressed pipe installation; Install the first arched prestressed pipe and the second arched prestressed pipe along the predetermined position in the template to ensure that their positions and quantities meet the design requirements; and inspect the installed first arched prestressed pipe and the second arched prestressed pipe to ensure that there is no deviation and they are firmly fixed; S4. Extended metal mesh 42 and reinforcement block laying; According to the fixing effect of the template in S2, the reinforcing shaft 41 in the embedded reinforcing member 4 is installed in the area between the first arched prestressed pipe and the second arched prestressed pipe, so that the reinforcing shaft 41 extends and is alternately distributed along the long side direction of the prestressed beam, and then the extended metal mesh 42 is alternately passed through the surface of the reinforcing shaft 41 up and down, and then one end of the extended metal mesh 42 is fixed to the reinforcing shaft 41 at the end, and the other end is fixed to the reinforcing shaft 41 at the other end after adjusting the tension; S5. Concrete pouring; Mix concrete according to the designed mix ratio to ensure that its strength and workability meet the engineering requirements; pour concrete in the formwork to avoid segregation and voids during the pouring process; vibrate the concrete with a vibrator to eliminate bubbles and ensure that the concrete is dense; S6. Maintenance and demoulding; After the concrete is poured, it is cured as required to ensure its strength growth and crack resistance. After the concrete reaches the designed strength, the formwork is removed and the surface is treated; S7. Tension prestressing; The prestressed steel strand in S1 is passed through the first arched prestressed pipe and the second arched prestressed pipe, and then the first arched prestressed pipe is tensioned first and then the second arched prestressed pipe is tensioned, and then the prestressed steel strand is tensioned in the first arched prestressed pipe and the second arched prestressed pipe respectively according to the design requirements and in sequence, and the prestress is applied by tensioning equipment; after the tensioning is completed, anchoring is performed to ensure that the prestressed steel strand is stable in force; The tension ratio of the tensioned prestressed steel strand in the first arched prestressed pipe is greater than the tension ratio of the prestressed steel strand in the second arched prestressed pipe; S8. Inspection and acceptance The bearing capacity and deformation of the beam are tested to ensure that they meet the design standards; after completing various tests, a final acceptance is carried out to ensure that the construction quality meets the requirements.
[0045] Working principle: Before construction, construction preparation is carried out first, then the formwork of the beam is built to ensure that its size and shape meet the design requirements, and it is reinforced to withstand the dead weight of the concrete and the construction load.
[0046] Install the first arch prestressed pipe and the second arch prestressed pipe along the predetermined position in the template to ensure that their position and quantity meet the design requirements; and check the installed first arch prestressed pipe and the second arch prestressed pipe to ensure that there is no deviation and they are firmly fixed.
[0047] According to the fixing function of the template, the reinforcement shaft 41 in the embedded reinforcement member 4 is installed in the area between the first arched prestressed pipe and the second arched prestressed pipe, so that the reinforcement shaft 41 extends and is distributed alternately along the long side direction of the prestressed beam, and then the extended metal mesh 42 is alternately passed through the surface of the reinforcement shaft 41 up and down, and then one end of the extended metal mesh 42 is fixed to the reinforcement shaft 41 at the end, and the other end is fixed to the reinforcement shaft 41 at the other end after adjusting the tension.
[0048] Then pour the concrete in the formwork, try to avoid segregation and voids during the pouring process; vibrate the concrete with a vibrator to eliminate bubbles and ensure that the concrete is dense.
[0049] After the concrete is poured, it is cured as required to ensure its strength growth and crack resistance; after the concrete reaches the designed strength, the formwork is removed and the surface is treated.
[0050] Then the prestressed steel strand is passed through the first arched prestressed pipe and the second arched prestressed pipe, and then the first arched prestressed pipe is tensioned first and then the second arched prestressed pipe is tensioned. Then the prestressed steel strand is tensioned in the first arched prestressed pipe and the second arched prestressed pipe respectively according to the design requirements and in sequence, and prestress is applied using tensioning equipment; after the tensioning is completed, anchoring is performed to ensure that the prestressed steel strand is stable in force.
[0051] The above are all preferred embodiments of the present application, and the protection scope of the present application is not limited thereto. Therefore, any equivalent changes made according to the structure, shape, and principle of the present application should be included in the protection scope of the present application.
Claims
1. A post-tensioned prestressed beam with a large spatial span, comprising a cast beam body (1), characterized in that: A first arched prestressed pipe is arranged inside the cast beam body (1) and along its own length direction, and a plurality of the first arched prestressed pipes are arranged at equal intervals along the width direction of the cast beam body (1), and a first steel strand (2) is arranged inside the first arched prestressed pipe of the cast beam body (1); two ends of the first steel strand (2) respectively penetrate through two ends of the first arched prestressed pipe of the cast beam body (1) and are connected to a first tensioning structure; A second arched prestressed pipe is arranged inside the cast beam body (1) and along its own length direction, and a plurality of the second arched prestressed pipes are arranged at equal intervals along the width direction of the cast beam body (1). A second steel strand (3) is arranged inside the second arched prestressed pipe of the cast beam body (1); two ends of the second steel strand (3) respectively penetrate through two ends of the second arched prestressed pipe of the cast beam body (1) and are connected to a second tensioning structure; The center of the arc segment corresponding to the second arched prestressed pipe coincides with the center of the arc segment corresponding to the first arched prestressed pipe, and the second arched prestressed pipe is located inside the first arched prestressed pipe.
2. The large spatial span post-tensioned prestressed beam according to claim 1, characterized in that: A pre-buried reinforcement member (4) is provided between the first steel strand (2) and the second steel strand (3).
3. The large spatial span post-tensioned prestressed beam according to claim 2, characterized in that: The embedded reinforcement member (4) comprises a plurality of reinforcement shafts (41) arranged along the width direction of the cast beam body (1), the plurality of reinforcement shafts (41) are parallel to each other, and the reinforcement shafts (41) are arranged alternately up and down along an arc track.
4. The large spatial span post-tensioned prestressed beam according to claim 3, characterized in that: The embedded reinforcement member (4) further comprises an extended metal mesh (42), wherein the extended metal mesh (42) passes through the surface of the reinforcement shaft (41) alternately up and down.
5. The large spatial span post-tensioned prestressed beam according to claim 4, characterized in that: A plurality of reinforcing protruding blocks (43) are evenly arranged on the mesh surface of the extended metal mesh (42), and the cross-section of the reinforcing protruding blocks (43) is a polygonal structure.
6. A construction method for a large spatial span post-tensioned prestressed beam as claimed in any one of claims 1 to 7, characterized in that: The construction steps include: S1. Construction preparation; Review the design drawings and construction plans in detail to ensure that all materials and specifications meet the requirements; purchase high-strength steel strands, concrete, expanded metal mesh (42), reinforcement bosses (43) and other construction materials and conduct quality inspections; and inspect concrete mixers, prestressing equipment, tensioning equipment and other construction tools to ensure that they are functioning properly; S2. Formwork construction; Construct formwork for beams to ensure that their size and shape meet design requirements and are reinforced to withstand the deadweight of the concrete and construction loads; S3. Prestressed pipe installation; Install the first arched prestressed pipe and the second arched prestressed pipe along the predetermined position in the template to ensure that their positions and quantities meet the design requirements; and inspect the installed first arched prestressed pipe and the second arched prestressed pipe to ensure that there is no deviation and they are firmly fixed; S4. Laying of extended metal mesh (42) and reinforcement blocks; According to the fixing function of the template in S2, a pre-buried reinforcement member (4) is installed in the area between the first arched prestressed pipe and the second arched prestressed pipe; S5. Concrete pouring; Mix concrete according to the designed mix ratio to ensure that its strength and workability meet the engineering requirements; pour concrete in the formwork to avoid segregation and voids during the pouring process; vibrate the concrete with a vibrator to eliminate bubbles and ensure that the concrete is dense; S6. Maintenance and demoulding; After the concrete is poured, it is cured as required to ensure its strength growth and crack resistance. After the concrete reaches the designed strength, the formwork is removed and the surface is treated. S7. Tension prestressing; The prestressed steel strands are tensioned according to the design requirements and prestressed using tensioning equipment; after tensioning, anchoring is performed to ensure that the prestressed steel strands are stable in force; S8. Inspection and acceptance; The bearing capacity and deformation of the beam are tested to ensure that they meet the design standards; after completing various tests, a final acceptance is carried out to ensure that the construction quality meets the requirements.
7. The construction method of a large spatial span post-tensioned prestressed beam according to claim 6, characterized in that: In S4, the embedded reinforcement member (4) includes a reinforcement shaft (41), and the reinforcement shaft (41) is first installed so that the reinforcement shaft (41) extends and is alternately distributed along the long side direction of the prestressed beam.
8. The construction method of the post-tensioned prestressed beam with a large spatial span according to claim 7 is characterized in that: In S4, after the reinforcement shaft (41) is installed, the extended metal mesh (42) is passed through the surface of the reinforcement shaft (41) alternately up and down, and then one end of the extended metal mesh (42) is fixed to the reinforcement shaft (41) at the end, and the other end is fixed to the reinforcement shaft (41) at the other end after adjusting the tension.
9. The construction method of a large spatial span post-tensioned prestressed beam according to claim 6, characterized in that: In S7, the prestressed steel strands in S1 are passed through the first arched prestressed pipe and the second arched prestressed pipe, and then the first arched prestressed pipe is tensioned first and then the second arched prestressed pipe is tensioned in sequence.
10. The construction method of a large spatial span post-tensioned prestressed beam according to claim 9, characterized in that: The tensioning ratio of the prestressed steel strand in the first arched prestressed pipe is greater than the tensioning ratio of the prestressed steel strand in the second arched prestressed pipe.