Fabricated prestressed beam with evacuated middle part

Abstract

The utility model relates to the technical field of prestressed beams, in particular to an assembly type prestressed beam with an evacuated middle part, which comprises a U-shaped beam and a floor support plate arranged on the top surface of the U-shaped beam, an anchor bar structure for connecting the U-shaped beam and the floor support plate is arranged between the U-shaped beam and the floor support plate, and a prestressed bar structure is arranged in the U-shaped beam. By optimizing the cross section form, the problem that the self-weight burden of the beam is large due to the fact that the cross section of the prestressed beam under the large span is too large is effectively solved, and the bearing capacity of the beam can be effectively improved while the rigidity is not affected.

Description

Technical Field

[0001] The utility model relates to the technical field of prestressed beams, in particular to an assembled prestressed beam with a hollowed-out middle portion. Background Art

[0002] Prestressed concrete structures are increasingly used in the construction industry. Before the structural components are subjected to external loads, pressure is artificially applied to them. The resulting prestressed state is used to reduce or offset the tensile stress caused by the external load. That is, the higher compressive strength of concrete is used to compensate for its lack of tensile strength, thereby delaying the cracking of concrete in the tensile zone.

[0003] Due to the significant role of prestressed concrete structures, prestressed structures in long-span structures are receiving increasing attention and attention. However, to ensure strength and rigidity, long-span concrete beams require larger cross-sections. The larger the beam cross-section, the higher the proportion of its deadweight load in the total load. Therefore, optimizing the cross-section of the prestressed beam and reducing its deadweight without affecting rigidity can effectively improve the beam's load-bearing capacity. Utility Model Content

[0004] The purpose of the utility model is to provide a prestressed beam with a hollow center, which is hollow and uses an anchor structure to fix the beam and the floor slab together to improve the rigidity of the beam.

[0005] The technical solution adopted by the present invention to solve its technical problems is: an assembled prestressed beam with a hollow middle portion, comprising a U-shaped beam and a floor decking plate arranged on the top surface of the U-shaped beam, an anchor bar structure connecting the U-shaped beam and the floor decking plate is arranged between the two, and a prestressed bar structure is arranged inside the U-shaped beam.

[0006] Preferably, the U-shaped beam includes two side plates and a bottom plate, and the prestressed tendon structure is arranged in the two side plates.

[0007] Preferably, longitudinal reinforcement is provided in both side plates and the bottom plate of the U-shaped beam.

[0008] Preferably, the two side plates and the bottom plate of the U-shaped beam are provided with at least two layers of longitudinal reinforcement along their respective thickness directions.

[0009] Preferably, the U-shaped beam is provided with several groups of internal stirrups along its length direction, and each group of internal stirrups comprises several U-shaped steel bars respectively connected to each layer of the internal longitudinal reinforcement of the beam.

[0010] Preferably, the floor deck is a steel truss floor deck.

[0011] Preferably, the anchor bar structure is evenly distributed in several groups along the length direction of the U-shaped beam.

[0012] Preferably, the anchor bar structure includes a pre-embedded part arranged on the top of the U-shaped beam. The pre-embedded part is connected to the U-shaped beam through the lower anchor bars, and the pre-embedded part is connected to the floor bearing plate through the upper top studs.

[0013] Preferably, four anchor bars are welded to the pre-embedded part, and the top studs pass through the bottom formwork of the steel bar truss and are welded to the pre-embedded part.

[0014] Preferably, the prestressed tendon structure includes a prestressed duct, a tension bar arranged in the prestressed duct, and concrete filling the prestressed duct.

[0015] The beneficial effects of the present utility model are as follows: An assembled prestressed beam with a hollow middle part includes a U-shaped beam and a floor bearing plate arranged on the top surface of the U-shaped beam. An anchor bar structure for connecting the two is arranged between the U-shaped beam and the floor bearing plate, and a prestressed tendon structure is arranged in the U-shaped beam. By optimizing the cross-sectional form, the present utility model effectively reduces the problem of the large self-weight burden of the prestressed beam caused by the too large cross-section of the prestressed beam under large spans, and can effectively improve the bearing capacity of the beam without affecting the stiffness. Description of the Drawings

[0016] Figure 1 is a schematic sectional view of an assembled prestressed beam with a hollow middle part of the present utility model;

[0017] Figure 2 is an isometric schematic view of an assembled prestressed beam with a hollow middle part of the present utility model;

[0018] Figure 3 is a schematic diagram of the steel bar arrangement of an assembled prestressed beam with a hollow middle part of the present utility model.

[0019] Description of the Reference Numerals:

[0020] 1 - U-shaped beam, 11 - longitudinal bars in the beam, 12 - stirrups in the beam, 2 - floor bearing plate, 3 - anchor bar structure, 31 - pre-embedded part, 32 - anchor bars, 33 - top studs, 4 - prestressed tendon structure. Detailed Embodiments

[0021] The following further describes the present utility model in detail with reference to the drawings and specific embodiments, and does not limit the scope of implementation of the present utility model thereto.

[0022] As Figures 1 to 3 shown, an assembled prestressed beam with a hollow middle part in this embodiment includes a U-shaped beam 1 and a floor bearing plate 2 arranged on the top surface of the U-shaped beam 1. An anchor bar structure 3 for connecting the two is arranged between the U-shaped beam 1 and the floor bearing plate 2, and a prestressed tendon structure 4 is arranged in the U-shaped beam 1.

[0023] In this embodiment, the U-shaped beam 1 is taken as an example for illustration, but it is not limited to the U-shaped structural beam, and it can also be applied to other structural beams in the middle of the interior.

[0024] The thickness of the bottom plate of the U-shaped beam 1 is not less than that of the two side plates, and the thickness of the two side plates should be able to meet the setting standard of the prestressed tendon structure 4. At least two layers of longitudinal bars 11 in the beam are arranged along the width direction of the bottom plate and the two side plates of the U-shaped beam 1, and at least two layers of the longitudinal bars 11 in the beam are close to the surfaces of the bottom plate or the two side plates. According to the thickness of the bottom plate and the two side plates of the U-shaped beam 1, the additional longitudinal bars 11 in the beam with more than two layers are located in the middle of the bottom plate and the two side plates. In order to connect each of the longitudinal bars 11 in the beam into one body, a U-shaped steel bar is arranged for each layer of the longitudinal bars 11 in the beam to connect and fix each of the longitudinal bars 11 in the beam of this layer into one body, and then the U-shaped steel bars of each layer are connected into one body through steel bars. A plurality of U-shaped steel bars in the same plane form a group of stirrups 12 in the beam, and several groups of the stirrups 12 in the beam are arranged along the length direction of the U-shaped beam.

[0025] Several groups of the anchor bar structures 3 are evenly distributed along the length direction of the U-shaped beam. In this embodiment, the spacing between two adjacent anchor bar structures 3 is 200 mm; the anchor bar structure 3 includes a pre-embedded part 31 arranged on the top of the U-shaped beam 1, the pre-embedded part 31 is connected to the U-shaped beam 1 through the lower anchor bars 32, and the pre-embedded part 31 is connected to the floor slab formwork 2 through the upper stud bolts 33.

[0026] The floor slab formwork 2 in this embodiment adopts a steel bar truss floor slab formwork.

[0027] During construction operations, the pre-embedded part 31 with four anchor bars 32 welded at the bottom is placed on the top of the U-shaped beam 1, and integral pouring is carried out. After the pouring is completed, the whole pre-embedded part 31 is wrapped by the concrete of the U-shaped beam 1, but the upper surface of the pre-embedded part 31 is exposed. After the U-shaped beam 1 is cured, the formwork is removed. Then, the steel bar truss of the floor slab formwork 2 is placed on the top of the U-shaped beam 1, and the stud bolts 33 are passed through the bottom formwork of the steel bar truss and welded to the pre-embedded part 31. The height of the stud bolts 33 remaining in the floor slab formwork 2 is not less than 80% of the thickness of the floor slab formwork 2; alternatively, the stud bolts 33 can be welded to the pre-embedded part 31 first, then holes are drilled in the bottom formwork of the steel bar truss, and then the steel bar truss is placed; finally, the floor slab formwork 2 is poured.

[0028] This embodiment adopts the anchor bar structure 3 to connect the U-shaped beam 1 and the floor slab formwork 2, so that the stiffness of the U-shaped beam 1 can be enhanced by using the floor slab formwork 2.

[0029] The prestressed tendon structure 4 includes prestressed ducts, tension bars arranged in the prestressed ducts, and concrete filling the prestressed ducts. In this embodiment, the post-tensioning method is adopted for setting the prestressed tendons. Therefore, prestressed ducts need to be preset when casting the U-shaped beam 1. After the U-shaped beam 1 is completely cured, tension bars with a certain tension are arranged in the prestressed ducts, and concrete is poured.

[0030] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention. For the convenience of describing the technical solutions, the front, rear, left, right, upper, middle, lower and other orientations adopted are based on the drawings, rather than limiting the protection scope of the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that the technical solutions of the present invention can be modified or equivalently replaced without departing from the essence and scope of the technical solutions of the present invention.

Claims

1. An assembled prestressed beam with a hollow middle part, characterized in that: It includes a U-shaped beam and a floor bearing plate arranged on the top surface of the U-shaped beam. An anchor bar structure for connecting the two is arranged between the U-shaped beam and the floor bearing plate, and a prestressed tendon structure is arranged in the U-shaped beam.

2. The prefabricated prestressed beam with a hollow middle part according to claim 1, characterized in that: The U-shaped beam includes two side plates and a bottom plate, and the prestressed tendon structure is arranged in the two side plates.

3. The prefabricated prestressed beam with a hollow middle according to claim 2, characterized in that: Longitudinal bars in the beam are arranged in both the two side plates and the bottom plate of the U-shaped beam.

4. A prefabricated prestressed beam with a hollow middle according to claim 2, characterized in that: At least two layers of longitudinal bars in the beam are arranged in the two side plates and the bottom plate of the U-shaped beam along their respective thickness directions.

5. The prefabricated prestressed beam with a hollow middle according to claim 4, characterized in that: A number of groups of stirrups in the beam are arranged along the length direction of the U-shaped beam. Each group of stirrups in the beam includes a number of U-shaped steel bars respectively connecting each layer of the longitudinal bars in the beam.

6. The precast prestressed beam with a hollow middle according to claim 1, characterized in that: The floor bearing plate is a steel truss floor bearing plate.

7. A prefabricated prestressed beam with a hollow middle according to claim 1, characterized in that: A number of groups of the anchor bar structure are evenly distributed along the length direction of the U-shaped beam.

8. A prefabricated prestressed beam with a hollow middle according to claim 1, characterized in that: The anchor bar structure includes embedded parts arranged on the top of the U-shaped beam. The embedded parts are connected to the U-shaped beam through lower anchor bars, and the embedded parts are connected to the floor bearing plate through upper stud bolts.

9. The prefabricated prestressed beam with a hollow middle according to claim 8, characterized in that: Four lower anchor bars are welded to the embedded parts, and the stud bolts pass through the bottom formwork of the steel truss and are welded to the embedded parts.

10. A prefabricated prestressed beam with a hollow middle according to claim 1, characterized in that: The prestressed tendon structure includes a prestressed duct, a tension bar arranged in the prestressed duct, and concrete filling the prestressed duct.

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