CN104727441B - Prestress assembled concrete beam column joint structure and construction method thereof - Google Patents

Abstract

The invention relates to a prestressed assembled concrete beam-column joint structure and a construction method thereof, comprising a prefabricated column and a prefabricated beam, and the prefabricated beam and the prefabricated column are prestressed and connected through prestress formed by tensioning of prestressed steel bars. The bottom of the beam end on one side of the node is connected to the top of the beam end on the other side through prestressed tendons, and a symmetrical crossing arrangement of prestressed tendons is formed on the facade. When making prefabricated beams, the prestressed tendons and their anchors are pre-embedded at the bottom of the beam ends, and the prestressed tendon channels and anchorage areas are reserved at the top of the beam ends, and open stirrups are used in the anchorage areas. The beam end section is welded with the longitudinal reinforcement to set the force transmission steel plate. Oblique prestressed tendon channels are reserved in the joint area of prefabricated columns, and channel-shaped steel plates are pre-embedded on both sides of the column joints, and high-damping rubber layers are pasted inside the channel-shaped steel plates. When connecting, the beam is clamped into the channel steel, and the prestressed tendon passes through the core area of the node to the top of the beam end on the other side, and is anchored after being stretched to the design stress. The invention is convenient for assembly and construction, and can realize high shear resistance capacity, energy consumption capacity and self-resetting capacity of the connecting nodes.

Description

A prestressed assembled concrete beam-column joint structure and its construction method

technical field

The invention relates to a prestressed assembled concrete beam-column node structure and a construction method thereof in the field of construction.

Background technique

The prefabricated concrete structure refers to the structural system in which the main load-bearing components of the structural system, such as beams, columns, walls, etc., are prefabricated and transported to the construction site for assembly. Prefabricated concrete structures are being rapidly popularized and applied due to their advantages of energy saving, environmental protection, and little impact on the construction environment. In terms of the mechanical properties of the structure, the key issue of the prefabricated structure is the reliability of the connecting nodes. Previous structural earthquake damages have shown that the main cause of failure of most prefabricated structures is the failure of the structural system due to the failure of the beam-column joints.

Prestressed preloaded connection is a main type of node connection in prefabricated structures. The connecting section resists shear through the friction generated by the beam-column preload, while the prestressed tendon can be used for the bending resistance of the connecting section. In the prestressed connection of beams and columns of frame structures currently used, the prestressed steel bars are usually arranged along the entire length of the beam. Use more prestressed steel bars. This puts higher demands on the installation process. How to make the connection section have higher strength and facilitate construction through reasonable design is one of the key issues of prestressed connection.

Previous experimental studies have shown that prestressed prefabricated joints exhibit nonlinear elastic mechanical properties and have high deformation recovery capabilities, but their energy dissipation capabilities are weak, and they are prone to large deformations under earthquake action. Therefore, ensuring that the prefabricated structure has a certain energy dissipation capacity through reasonable node design has a positive effect on improving the overall seismic performance of the prefabricated structure.

Contents of the invention

The technical problem to be solved by the present invention is to construct a prestressed assembled concrete beam-column node with convenient assembly and construction, high shear resistance, energy dissipation capacity and self-resetting capacity and its construction method.

The technical scheme adopted by the present invention to solve the technical problem is: to construct a prestressed assembled concrete beam-column joint structure, including prefabricated columns, prefabricated beams and prestressed tendons, and to bury channel steel on both sides of the joints of the prefabricated columns, The channel steel on both sides is welded and connected by the steel bars passing through the core area of the node. The high damping rubber layer is pasted in the groove of the channel steel. The above-mentioned prefabricated beams are clamped into the grooves of the channel steel, and the prefabricated beams on both sides of the node are connected by the prestressed steel bars passing through the core area of the node. At the top, it is arranged in an "X" shape on the facade.

In the above scheme, the prestressed steel bars are arranged only at the end of the beam, and are arranged in three or more lines, and are symmetrically arranged in two directions from the bottom of the beam end on both sides to the top of the other side beam end. The vertical component balance of the resultant prestress force.

In the above solution, the two sides of the prefabricated column node are provided with channel-shaped steel plates for improving the shear resistance of the connecting section.

In the above solution, the channel-shaped steel plate is provided with a high-damping rubber layer for improving the energy dissipation capacity of the node during deformation.

The present invention also provides a construction method for prestressed assembled concrete beam-column joint construction, comprising the following steps:

S1. Manufacture of prefabricated beams: arrange beam longitudinal reinforcement and stirrups, pre-embed prestressed tendons on the lower side of beam ends, connect anchors at the ends of prestressed tendons, pre-embed hole-forming materials on the upper side of beam ends to form prestressed tendon tunnels, and pre-stress The prestressed reinforcement anchorage area is reserved, and the end of the longitudinal reinforcement of the beam is welded with the steel plate. After the reinforcement layout is completed, the formwork is poured with concrete and cured to reach the design strength;

S2. Fabrication of prefabricated columns: Arrange the longitudinal reinforcement and stirrups of the column in place, weld the grooved steel plates with rubber layers on both sides through the reinforcement, and the reinforcement passes through the node area; arrange holes in the node area and reserve the material Prestressed tendon channel, cast concrete and maintain;

S3. Hoist the prefabricated beam and prefabricated column in place, pass the prestressed steel bar through the core area of the column joint, pass through the prestressed tendon channel on the upper side of the beam end on the other side, clamp the steel plate at the beam end into the channel steel plate, and tension the prestressed steel bar. Stressed steel bars are anchored to the design stress, and the prestressed steel bars are arranged in an "X" shape on the facade; the open stirrups in the anchorage area are bound and sealed, and the upper surface of the beam is leveled by pouring concrete.

Implementing the prestressed assembled concrete beam-column joint structure and construction method thereof of the present invention has the following beneficial effects:

1. The prestressed steel bars are arranged in an "X" shape. Under the action of horizontal load, the bending moment of the beam ends on both sides of the column is antisymmetrically distributed, and the tension areas of the beam ends on both sides are connected by the same prestressed tendons. A large amount of elongation will produce a higher stress growth, thereby forming a higher self-recovery ability of the node deformation.

2. Under the action of bending moment, the beams and columns will rotate relative to each other at the joints, and the high-damping rubber arranged between the beams and columns will switch between the tension zone and the compression zone, so that the rubber layer is repeatedly pulled and compressed to generate energy dissipation, which plays a role Improve the structural damping ratio and reduce the structural dynamic response.

3. After the assembly is completed, the beam end should be snapped into the channel-shaped steel plate, and the channel-shaped steel plate flange plate can bear part of the shear force of the section.

4. The prestressed steel bars are only connected to the beam ends on both sides of the column. The prestressed steel bars are arranged in a short length and arranged in a straight line, with low prestress loss and easy construction.

5. The channel-shaped steel plate and the steel plate at the end of the beam can make the force transmission on the surface of the beam and column more uniform, and reduce the possibility of local compression of the concrete.

6. The construction scope of the concrete beam-column joint structure is small during the prestressed assembly, and the construction operation is convenient.

Description of drawings

The present invention will be further described below in conjunction with accompanying drawing and embodiment, in the accompanying drawing:

Fig. 1 is the schematic diagram of the facade that beam-column node of the present invention forms;

Fig. 2 is the schematic diagram of the plane that the beam-column node of the present invention forms;

Fig. 3 is the schematic diagram of prefabricated beam of the present invention;

Figure 4 is a schematic diagram of the open stirrup used in the anchorage area at the top of the beam end.

detailed description

In order to have a clearer understanding of the technical features, purposes and effects of the present invention, the specific implementation manners of the present invention will now be described in detail with reference to the accompanying drawings.

As shown in Figures 1-3, the prestressed fabricated concrete beam-column joint structure of the present invention includes a prefabricated column 1 passing through the joint area, prefabricated beams 2 arranged on both sides of the joint, prestressed steel bars 9, and prefabricated beams 2 integrated Beam-end steel plate 4 poured together, channel-shaped steel plate 5 on both sides of the node that is welded and connected with steel bars 8 and integrally poured together with the column, high damping rubber layer 6, concrete post-casting belt 7 in the tension anchorage area.

Channel steel 5 is buried on both sides of the joint between prefabricated column 1 and prefabricated beam 2, and the channel steel 5 on both sides is welded and connected by steel bars 8 passing through the core area of the node. 2 is provided with an end steel plate 4, the beam end longitudinal reinforcement of the prefabricated beam 2 is extended and welded on the end steel plate 4, the end steel plate 4 is inserted into the groove of the channel steel 5, and the prefabricated beam 2 on both sides of the node is formed by Connected by the prestressed steel bars 9 in the core area of the node, the prestressed steel bars 9 are arranged obliquely and straightly to connect the bottom of the prefabricated beam 2 on one side and the top of the prefabricated beam 2 on the other side, and are arranged in an "X" shape on the facade.

One or two prestressed tendons 9 are pre-embedded on the lower side of the beam end of the prefabricated beam 2. In this embodiment, the prestressed reinforcing bars 9 are arranged in three lines, the middle one is arranged in the opposite direction to the side two prestressed tendons, and the side two prestressed tendons The tendon tension is half of the middle prestressed tendon tension. The ends of the prestressed tendons 9 are connected to the anchors, and the prefabricated beam 2 is provided with a prestressed tendon channel 3 and an anchorage area on the upper side of the beam end, and an open stirrup is used in the anchorage area to facilitate the anchoring construction of the prestressed tendons, as shown in Figure 4.

The present invention also provides a construction method for the above node structure, comprising the following steps:

S1. For prefabricated beams, beam longitudinal bars and stirrups shall be arranged according to general concrete structure design requirements. One or two prestressed steel bars 9 are pre-embedded on the lower side of the beam end, and the ends of the prestressed bars are connected with anchors. The hole-forming material is pre-embedded on the upper side of the beam end to form the prestressed tendon channel 3, and an anchorage area for the prestressed tendon is reserved. The stirrups in the anchorage area are open-type stirrups (Figure 4), and the steel plate 4 at the beam end is welded to the longitudinal reinforcement of the beam. After all the reinforcing bars are laid out, the formwork is poured with concrete and cured to reach the design strength.

S2. For prefabricated columns, before pouring concrete, the longitudinal bars and stirrups of the column are arranged in place, and the grooved steel plates 5 pasted with rubber layers 6 on both sides are welded together through steel bars 8, and the steel bars 8 pass through the joint core area. In the core area of the node, the hole material is arranged according to the design position of the prestressed steel bar 9 to form the channel of the prestressed steel bar, and then the formwork is poured with concrete and maintained.

S3. After the prefabrication of columns and beams is completed, they shall be assembled and connected at the construction site. Hoist the beam and column in place, pass the prestressed tendon at the beam end through the core area of the column joint, pass through the prestressed tendon channel at the top of the beam end on the other side, and clamp the beam into the channel-shaped steel plate. The prestressed steel bars are stretched to the design stress on both sides and anchored. In Fig. 3, 9 prestressed reinforcement bars are arranged in three lines, and the middle one is arranged oppositely to the side two prestressed bars, and the tensile force of the two side prestressed bars is half of the tension force of the middle prestressed bars. This can ensure the balance of the vertical components of the resultant force of the prestressed tendons in the two directions, and avoid additional out-of-plane bending moments in the beam. After all the prestressed steel bars are anchored, the open stirrups in the anchorage area are bound and sealed, and the upper surface of the beam is leveled by pouring concrete in the anchorage area on the upper side of the beam end.

Embodiments of the present invention have been described above in conjunction with the accompanying drawings, but the present invention is not limited to the above-mentioned specific implementations, and the above-mentioned specific implementations are only illustrative, rather than restrictive, and those of ordinary skill in the art will Under the enlightenment of the present invention, many forms can also be made without departing from the gist of the present invention and the protection scope of the claims, and these all belong to the protection of the present invention.

Claims (1)

1. A construction method of prestressed assembled concrete beam-column joint structure, is characterized in that, comprises the following steps: S1. Manufacture of prefabricated beams: arrange beam longitudinal reinforcement and stirrups, pre-embed prestressed steel bars on the lower side of the beam end, connect anchors at the end of the prestressed steel bar, and pre-embed hole-forming materials on the upper side of the beam end to form prestressed tendon tunnels, and pre-stress The prestressed reinforcement anchorage area is reserved, and the longitudinal reinforcement of the beam is welded to the steel plate at the beam end. After the reinforcement layout is completed, the formwork is poured with concrete and cured to reach the design strength; S2. Fabrication of prefabricated columns: Arrange the longitudinal reinforcement and stirrups of the column in place, weld the grooved steel plates with rubber layers on both sides together through the reinforcement, and the reinforcement passes through the core area of the node; arrange hole-forming materials in the core area of the node Reserve the prestressed tendon channel, set up the formwork to pour concrete and maintain it; S3. Hoist the beam and column in place, pass the prestressed steel bar through the core area of the column joint, and pass through the prestressed tendon channel on the upper side of the beam end on the other side, clamp the steel plate at the beam end into the channel steel plate, and stretch the prestressed steel bar When the design stress is reached and anchored, the prestressed steel bars are arranged in an "X" shape on the facade; the open stirrups in the anchorage area are bound and sealed, and the upper surface of the beam is leveled by pouring concrete.