CN201024538Y - Prefabricated prestressed concrete structural beam and column hybrid joints - Google Patents

Abstract

The invention relates to a prefabricated prestressed concrete structure beam and column mixed connection joint, which belongs to the technical field of concrete structure. It consists of prefabricated columns (1) and prefabricated beams (2), both of which are composed of unbonded prestressed tendons (6). ) is a single-bay member, the shortest length of the spiral reinforcement (8) in the beam is the length of the short side of the beam, the stirrups (10) are densely distributed in the node area of the beam, and the arrangement length of the stirrups (10) is the length of the short side of the beam, and the additional structure in the beam The steel bar (9) passes through the non-prestressed bonding rib (5) in the bellows (3), leaving a 30-40mm wide gap between the column (1) and the beam (2). This joint can be widely used in earthquake areas. The fabricated concrete structure using this joint has excellent seismic performance, which can reduce the residual deformation of the structure in the event of a large earthquake and reduce the damage of structural components.

Description

Prefabricated prestressed concrete structural beam and column hybrid joints

technical field

The prefabricated prestressed concrete structure beam-column hybrid connection node is a node processing form, which belongs to the technical field of prefabricated concrete structures in civil engineering.

Background technique

The seismic performance of prefabricated structures is determined by the connections between prefabricated components. Most areas in my country are in seismic fortification areas, so whether the connection is reliable or not directly affects the application of prefabricated structures. For a long time, due to the unsolved technical problems of assembled structure nodes, the application of assembled structures in my country's earthquake areas has been restricted. The current seismic codes generally encourage the use of cast-in-place nodes, which cause great pollution to the surrounding environment. , such as the waste of construction water and construction materials, and the noise brought by the construction also troubles the surrounding residents.

Utility model content

In order to improve the seismic performance of prefabricated structures, we proposed a prefabricated prestressed concrete structural beam and column hybrid joint through research. The utility model can provide a new type of connection node that does not require cast-in-place concrete and can make the assembled concrete structure have good seismic performance. This node can be used for both side column nodes and center column nodes in the structure , can be widely used in earthquake-resistant areas.

The structural connection of the present utility model is shown in Fig. 1, 2, is made up of prefabricated column 1 and prefabricated beam 2, and both are formed integral body by unbonded prestressed tendon 6. Its characteristics are: column 1 is a member that passes continuously through 2-3 floors to ensure the continuity of the column; beam 2 is a single-bay member, and the length of the spiral rib 8 arranged in the beam is the length of the short side of the beam. Stirrup bars 10 are densely distributed near the area, and the length of the stirrup bars 10 is the length of the short side of the beam. The structural steel bar 9 is arranged along the beam height, and the non-prestressed bonding rib 5 is passed through the bellows 3. There is a gap between the column 1 and the beam 2. There is a 30-40mm wide gap, which can not only adjust the dimensional error during structure installation, but also ensure the effective connection between the beam 2 and the column 1. The gap 4 is closed by the non-shrinkage grouting material. When the strength of the grouting material reaches 70% of its design strength, the grouting of the pre-embedded metal bellows channel 3 is carried out. When the design strength is reached, the unbonded prestressed tendons are 6 tensegrity.

The spacing of densely distributed stirrups 10 is 50-80mm, and the arrangement length is the length of the short side of the beam. The stirrups 10 can make the concrete in the beam in the joint area be in a restrained concrete state, so as to improve the ultimate compressive capacity of the concrete.

The disposition length of the spiral reinforcement 8 is the length of the short side of the section of the beam 2, and the diameter of the selected reinforcement is 8-10 mm.

The structural steel bars 9 are arranged along the beam height and length with a spacing of 200-300mm, and the structural steel bars 9 can increase the axial compressive capacity of the beam end.

The post-passing non-prestressed bonding rib 5 is mainly used to increase the energy dissipation capacity of the joint and assist in improving the bending resistance of the joint. Bonding and anchoring properties of non-prestressed steel bars.

The unbonded prestressed steel bar 6 can provide the clamping force at the beam-column interface, through this clamping force, it can resist the vertical shear force of the node due to the vertical load on the beam and the horizontal earthquake action, and at the same time, the clamping force can also make the The structure has good self-recovery ability, which reduces the residual deformation of the structure.

A steel plate should be pre-embedded on the anchoring surface of the side column. This steel plate can be used as a bearing plate when the unbonded prestressed tendon is stretched. Anchorage requirements for steel bars.

The use of such joints does not require on-site wet work to pour concrete, and also makes the structure have excellent seismic performance. The use of this kind of joint can make the nonlinear deformation of the structure mainly concentrate in the joint connection area under the condition of large earthquake, so that the damage is mainly concentrated at the beam-column interface, the damage degree of the structural components is light, and there are almost no large cracks on the beam. Since the prestressed tendons of this kind of joint are always in an elastic working state, the structure has strong self-recovery ability and small residual deformation, which reduces the repair work after the earthquake. This kind of node has less impact on the surrounding construction environment due to the reduction of wet work. This node can be widely used in earthquake areas, especially high-intensity areas, which brings huge benefits to my country's economic and social development, and has broad application prospects.

Description of drawings

The front elevation of the node in Figure 1

Figure 2 is the elevation view of the side and side nodes respectively

Fig. 3 is a sectional view along A-A of Fig. 1, 2;

Fig. 4 is the sectional view along B-B of Fig. 1, 2;

Fig. 5 is a sectional view along C-C of Fig. 2 .

In the figure: 1 is a column, 2 is a beam, 3 is a corrugated pipe, 4 is a gap, 5 is a non-prestressed bonded tendon, 6 is an unbonded prestressed tendon, 7 is a channel, 8 is a spiral steel bar, and 9 is a structural steel bar , 10 is a stirrup, and 11 is an embedded steel plate.

Note: In order to make the drawing clear, other reinforcements of beams and columns are not drawn, and other reinforcements should be determined according to the design.

Detailed ways

Example 1

The structure of the prefabricated prestressed concrete structural beam and column hybrid connection node is shown in Figure 1: column 1 and beam 2 are both prefabricated, the column is a component that passes continuously through 2-3 floors, and the beam is a single-bay component. After the column 1 is positioned, the beam 2 is hoisted and positioned by supporting or installing steel corbels on the column 1, and then the non-prestressed bonding rib 5 is passed through the bellows 3, and the corrugated tube 3 is left in the gap 4 when grouting. Air outlet, the setting of the air outlet can refer to the method of grouting with bonded prestressed channels, the gap 4 is closed by non-shrinkage joint filling material, and the early strength of the joint filling material is required, and its design compressive strength is not lower than that of the prefabricated column 1 and beam 2 design compressive strength. When the strength of the grouting material reaches 70% of its design strength, the grouting of the pre-embedded bellows channel 3 is performed, and when the design strength is reached, the unbonded prestressed tendons 6 are stretched.

The inner diameters of the pre-embedded corrugated pipe 3 and the pre-embedded non-bonded rib channel 7 are more than 7mm larger than the diameter of the steel bar to be worn. When there are multiple prestressed steel strands in the tunnel 7 without bonding ribs, the inner diameter of the tunnel 7 should be greater than 2 times of the total area of the steel strands.

The configuration length of the spiral reinforcement 8 is the length of the short side of the beam 2 section, the diameter of the selected steel bar is 8-10mm, the screw moment is 1/4 of the diameter of the spiral reinforcement, and the spiral diameter should be 0.5 times the length of the short side of the beam 2. Tunnels for prestressed tendons are included.

Structural steel bars 9 are arranged along the beam height and length, with a spacing of 200-300mm, and the diameter is set according to the requirements of GB50010-2002 structural bars.

The spacing of the densely distributed stirrups 10 is 50-80mm, the arrangement length is the length of the short side of the beam, and the diameter is set according to the requirements of the stirrups in the middle beam of GB50010-2002.

The allocation amount of non-prestressed bonded steel bar 5 should be determined according to the fact that it bears no more than half of the design flexural bearing capacity of the connecting section. The design principle of the prestress size of unbonded prestressed tendons is to ensure the frictional shear resistance of the joints and to keep the stress in the prestressed tendons in an elastic working state, so prestressed steel strands should be used.

Other design requirements shall comply with specifications GB50010-2002 and JGJ92-2004.

Example 2

When it is a side column node, see Figure 2, other measures are the same as in embodiment 1, except that the steel plate 11 is pre-embedded in the side column, and the post-passing non-prestressed bonding rib is welded to the steel plate 11 to increase the anchoring performance.

Claims (3)

1. A prefabricated prestressed concrete structural beam and column hybrid connection node, composed of prefabricated columns (1) and prefabricated beams (2), the two are composed of unbonded prestressed tendons (6); it is characterized in that: (1) is a member that passes continuously through 2-3 floors. The beam (2) is a single-bay member. The shortest length of the spiral reinforcement (8) in the beam is the length of the short side of the beam. The arrangement length of the ribs (10) is the length of the short side of the beam. The structural steel bar (9) is added to the beam, and the non-prestressed bonded ribs (5) are passed through the bellows (3). Leave a 30-40mm wide gap between them. 2. The prefabricated prestressed concrete structural beam and column hybrid connection node according to claim 1, characterized in that, the distance between the stirrups (10) is 50-80mm. 3. The prefabricated prestressed concrete structure beam-column hybrid connection node according to claim 1, characterized in that, the structural steel bars (9) are arranged along the beam height and length with a spacing of 200-300mm.