CN117266001A - Ultra-high performance concrete beam and construction method thereof - Google Patents

Abstract

The invention discloses an ultra-high performance concrete beam, which includes a concrete beam body and a steel plate assembly. The lower part of the web of the concrete beam body is set as a horseshoe-shaped beam. The steel plate assembly includes a steel plate and several steel tenon plates arranged on the steel plate. The steel plate is arranged along the edges of the steel plate. The length direction of the horseshoe-shaped beam is set at its bottom, and the steel tenon plate is anchored into the horseshoe-shaped beam. It has the advantages of improving crack resistance, simplifying construction procedures and improving construction efficiency.

Description

Ultra-high performance concrete beam and construction method thereof

Technical field

The invention relates to the technical field of bridge engineering, and in particular to an ultra-high performance concrete beam and a construction method thereof.

Background technique

The current application status of concrete beam bridges shows that due to the insufficient tensile properties and poor durability of ordinary concrete, concrete beams suffer from beam body cracking, joint leakage, concrete carbonization and other diseases, which seriously affect the safety of the bridge structure. On the other hand, the self-weight of concrete beams , It is difficult to hoist. In addition, in order to improve the load-bearing capacity and crack resistance of concrete beams, prestressed tendons are often stretched within the concrete beam to apply prestress to it.

Ultra-High Performance Concrete (hereinafter referred to as UHPC) is a new type of fiber-reinforced cement-based composite material. It has excellent mechanical properties, durability and working performance, and has good ductility and toughness after cracking, and can be used very well. to make up for the shortcomings of ordinary concrete. However, when UHPC is used in medium- and small-span girder bridges, for medium-span UHPC girder bridges, in order to meet the requirements of stiffness and bearing capacity, prestressed tendons need to be used. On the one hand, it is necessary to increase the web thickness of the UHPC girder, and on the other hand, it is necessary to increase the web thickness of the UHPC girder. On the other hand, the procedures such as tensioning and grouting of prestressed tendons are complicated and cumbersome, and the construction period is long.

Contents of the invention

The technical problem to be solved by the present invention is to overcome the shortcomings of the existing technology and provide an ultra-high performance concrete beam and its construction method that improve crack resistance, simplify construction procedures, and improve construction efficiency.

In order to solve the above technical problems, the present invention adopts the following technical solutions:

An ultra-high performance concrete beam, including a concrete beam body and a steel plate assembly. The lower part of the web of the concrete beam body is set as a horseshoe-shaped beam. The steel plate assembly includes a steel plate and several steel tenon plates arranged on the steel plate. The steel plate The steel tenon plate is arranged at the bottom of the horseshoe-shaped beam along its length direction, and the steel tenon plate is anchored into the horseshoe-shaped beam.

As a further improvement of the above technical solution:

The steel tenon plate is provided with reserved holes.

Steel bars are placed in the reserved holes.

Shear components are welded to the steel tenon plate.

The steel plate component is welded from steel plates.

The steel plate components are cut from hot-rolled H-shaped steel.

The cross-sectional shape of the concrete beam body is T-shaped or π-shaped.

The steel tenon plate is configured as a rectangular plate, a wedge-shaped plate or a rounded wedge-shaped plate.

A construction method for ultra-high performance concrete beams, including the following steps:

S1: Processing of prefabricated steel plate components in the factory;

S2: Transport the steel plate components to the concrete beam prefabrication factory, place steel bars in the reserved holes and/or weld shear members on the steel tenon plates, tie the steel bars, support the formwork, pour UHPC to form the concrete beam body and perform natural curing;

S3: After the natural curing is completed, the mold is removed and then steam cured.

Compared with the prior art, the advantages of the present invention are:

The concrete beam body of the present invention uses ultra-high performance concrete, which significantly reduces its own weight, reduces the difficulty of hoisting, and is easy to construct. By arranging steel plates at the bottom of the web, it greatly improves the crack resistance of the lower edge of the web and reduces the risk of cracking. , improves the bearing capacity of ultra-high performance concrete beams, eliminates the need to arrange prestressed tendons in the web, simplifies the construction process, reduces the difficulty of construction, and improves construction efficiency. In addition, the lower part of the web is set as a horseshoe-shaped beam, which can be used without On the premise of increasing the overall thickness of the web, the stress section is increased, providing sufficient space for the arrangement of steel plate components.

Description of the drawings

Figure 1 is a schematic diagram of the overall structure of Embodiment 1 of the present invention.

Figure 2 is a schematic diagram of hot-rolled H-shaped steel cutting according to Embodiment 1 of the present invention.

Figure 3 is a schematic structural diagram of the steel plate assembly according to Embodiment 1 of the present invention.

FIG. 4 is a cross-sectional view of FIG. 3 .

Figure 5 is a schematic structural diagram of the steel plate assembly according to Embodiment 2 of the present invention.

Figure 6 is a cross-sectional view of Figure 5 (with steel bars placed).

Figure 7 is a schematic diagram of hot-rolled H-shaped steel cutting according to Embodiment 3 of the present invention.

Figure 8 is a schematic structural diagram of the steel plate assembly according to Embodiment 3 of the present invention.

Figure 9 is a cross-sectional view of Figure 8 (shear members welded).

Each symbol in the figure represents:

1. Concrete beam body; 11. Horseshoe-shaped beam; 2. Steel plate components; 21. Steel plate; 22. Steel tenon plate; 221. Reserved holes; 3. Steel bars; 4. Shear components.

Detailed ways

The present invention will be further described in detail below with reference to the accompanying drawings and specific examples.

Example 1:

As shown in Figures 1 to 4, the first embodiment of the ultra-high performance concrete beam of the present invention includes a concrete beam body 1 and a steel plate assembly 2. The lower part of the web of the concrete beam body 1 is set as a horseshoe-shaped beam 11, and the steel plate assembly 2 2 includes a steel plate 21 and several steel tenon plates 22 arranged on the steel plate 21. The steel plate 21 is arranged at the bottom of the horseshoe-shaped beam 11 along its length direction. The steel tenon plates 22 are anchored into the horseshoe-shaped beam 11. Compared with traditional concrete beams, the concrete beam body 1 of the present invention uses ultra-high performance concrete, which significantly reduces its own weight, reduces the difficulty of hoisting, and is easy to construct. By arranging steel plates 21 at the bottom of the horseshoe-shaped beam 11, it improves the strength of the concrete beam body 1 The bending load-bearing capacity, through the longitudinal shear effect provided by the steel tenon plate 22, ensures that the concrete beam body 1 and the steel plate 21 are stressed together, reducing the slippage between the concrete beam body 1 and the steel plate 21 interface under the action of bending moment, so that The steel plate 21 plays a restraining and strengthening role, limiting the initiation and expansion of cracks at the lower edge of the horseshoe beam 11, greatly improving the crack resistance of the lower edge of the web, reducing the risk of cracking, eliminating the need to arrange prestressed tendons in the web, and simplifying construction. process, which reduces the construction difficulty and improves the construction efficiency. In addition, the lower part of the web is set as a horseshoe-shaped beam 11, which increases the stress section without increasing the overall thickness of the web, and provides a convenient way for the layout of the steel plate assembly 2 enough space.

In this embodiment, the steel tenon plate 22 is provided with reserved holes 221 . In this structure, a reserved hole 221 is opened on the steel tenon plate 22. When the horseshoe-shaped beam 11 is poured, the UHPC grouting material will flow into the reserved hole 221 to form a UHPC tenon. Through the mechanical engagement of the UHPC tenon and the steel tenon plate 22, , improve the synergy between the horseshoe beam 11 and the steel plate component 2, and enhance the shear resistance.

In this embodiment, the steel plate component 2 is cut from hot-rolled H-shaped steel. The existing industrial product H-shaped steel is fully utilized and cut and divided to form the steel plate component 2. There is no need to weld and connect the steel tenon plate 22 and the steel plate 21. The production is simple and the cost is low.

In this embodiment, the cross-sectional shape of the concrete beam body 1 is T-shaped. The structure is simple. In other embodiments, the cross-sectional shape of the concrete beam body 1 can also be set to a π shape.

In this embodiment, the steel tenon plate 22 is configured as a wedge-shaped plate. Its structure is simple and easy to form.

Example 2:

As shown in Figures 5 to 6, the second embodiment of the ultra-high performance concrete beam of the present invention is basically the same as Embodiment 1, and the only difference is:

In this embodiment, steel bars 3 are placed in the reserved holes 221 . In this embodiment, the steel bars 3 can be configured as straight bars. In other embodiments, they can also be configured as L-shaped or U-shaped steel bars. In this structure, the steel bars 3 are placed in the reserved holes 221 of the steel tenon plates 22 in the same row. Within, the synergistic force-bearing effect between the steel plate component 2 and the horseshoe-shaped beam 11 is improved, thereby improving the crack resistance.

In this embodiment, the steel plate assembly 2 is welded from steel plates. In this structure, the steel plate assembly 2 is made up of several steel tenon plates 22 welded and fixed on the steel plate 21. The width of the steel plate 21 is consistent with the width of the bottom of the horseshoe beam 11. The spacing between the steel tenon plates 22 is determined according to the stress of the structure. Each steel tenon plate 22 is an independent unit, and its design and arrangement are flexible. In this embodiment, two rows of steel tenon plates 22 are welded to the steel plate 21. In other embodiments, single or multiple rows of steel tenon plates 22 can be arranged according to the stress conditions. .

In this embodiment, the steel tenon plate 22 is configured as a rectangular plate. Its structure is simple and easy to form.

Example 3:

As shown in Figures 7 to 9, the third embodiment of the ultra-high performance concrete beam of the present invention is basically the same as Embodiment 1, and the only difference is:

In this embodiment, the shear member 4 is welded to the steel tenon plate 22 . In this structure, the shearing member 4 is set as a bolt, and the bolt is welded on the steel tenon plate 22 to further improve the cooperative force-bearing capacity of the steel plate assembly 2 and the horseshoe beam 11, and improve the crack resistance of the overall structure. In other embodiments , the steel bar 3 can be placed in the reserved hole 221, and the shear member 4 can be welded on the steel tenon plate 22.

In this embodiment, the steel tenon plate 22 is provided with a rounded wedge plate. Its structure is simple and easy to form. The rounded wedge plate eliminates sharp parts, prevents stress concentration at the contact point between the steel tenon plate 22 and the horseshoe beam 11, reduces the risk of premature damage to the structure, and makes the steel tenon plate 22 and the horseshoe beam 11 It has good force-bearing performance and improves the safety of the structure.

The construction method of ultra-high performance concrete beams in this embodiment includes the following steps:

S1: Processing of prefabricated steel plate components 2 in the factory;

S2: Transport the steel plate assembly 2 to the concrete beam prefabrication factory, weld the shear member 4 on the steel tenon plate 22, tie the steel bars, support the formwork, pour UHPC to form the concrete beam body 1 and perform natural curing;

S3: After the natural curing is completed, the mold is removed and then steam cured.

Although the present invention has been disclosed above in terms of preferred embodiments, this is not intended to limit the present invention. Any person familiar with the art can, without departing from the scope of the technical solution of the present invention, use the technical content disclosed above to make many possible changes and modifications to the technical solution of the present invention, or modify it into equivalent implementations with equivalent changes. example. Therefore, any simple modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention shall fall within the protection scope of the technical solution of the present invention.

Claims (9)

1. An ultra-high performance concrete beam, which is characterized in that: including concrete beam body (1) and steel sheet subassembly (2), the web lower part of concrete beam body (1) sets up to horseshoe beam (11), steel sheet subassembly (2) include steel sheet (21) and set up a plurality of tenon board (22) on steel sheet (21), steel sheet (21) are followed horseshoe beam (11) length direction sets up in its bottom, in tenon board (22) anchor horseshoe beam (11).

2. The ultra-high performance concrete beam of claim 1, wherein: the steel tenon plate (22) is provided with a preformed hole (221).

3. The ultra-high performance concrete beam of claim 2, wherein: reinforcing steel bars (3) are placed in the reserved holes (221).

4. The ultra-high performance concrete beam of claim 1, wherein: shear members (4) are welded on the steel tenon plates (22).

5. The ultra-high performance concrete beam of claim 1, wherein: the steel plate assembly (2) is formed by welding steel plates.

6. The ultra-high performance concrete beam of claim 1, wherein: the steel plate assembly (2) is formed by cutting hot rolled H-shaped steel.

7. The ultra-high performance concrete beam of claim 1, wherein: the section of the concrete beam body (1) is T-shaped or pi-shaped.

8. The ultra-high performance concrete beam of claim 1, wherein: the steel tenon plate (22) is arranged as a rectangular plate or a wedge plate or a round angle wedge plate.

9. A construction method based on the ultra-high performance concrete beam according to any one of claims 1 to 8, characterized in that: the method comprises the following steps:

s1: machining the prefabricated steel plate assembly (2) in a factory;

s2: transporting the steel plate assembly (2) to a concrete beam prefabrication factory, placing steel bars (3) in the reserved holes (221) and/or welding shear members (4) on the steel tenon plates (22), binding the steel bars and supporting templates, pouring UHPC to form a concrete beam body (1), and naturally curing;

s3: and (5) after the natural curing is finished, removing the die, and then performing steam curing.