CN105256891B - High-strength bottom muscle Precast Concrete Frame - Google Patents

Abstract

The invention discloses a prefabricated concrete frame structure with high-strength bottom reinforcement, which comprises a prefabricated concrete column, a prefabricated concrete beam, a stressed steel bar at the bottom of the beam, a U-shaped key groove, a core beam frame vertical reinforcement, a rectangular airtight stirrup, a core beam and a common beam top. Steel bars: U-shaped key grooves are left at the beam end of the prefabricated concrete beam and high-strength steel bars are used for the stressed steel bars at the bottom of the beam. Core beam frame vertical bars are arranged within the range of the U-shaped key groove above the stressed steel bars at the bottom of the beam, through which the core beam frame In the vertical bar, a rectangular closed stirrup around the stressed steel bar at the bottom of the beam is added in the U-shaped keyway to form a core beam; the stressed steel bar at the bottom of the beam protrudes from the beam end and bends upward to form a hook, and the protruding part is side-bent to avoid Open the main reinforcement of the precast concrete column and anchor it in the core area of the beam-column connection node. The structure of the invention enhances the anti-seismic performance of the prefabricated assembly frame structure, improves the universality of component production and on-site node installation, and conforms to the general trend of popularizing the use of high-strength steel bars.

Description

Precast concrete frame structure with high-strength bottom reinforcement

technical field

The invention relates to a prefabricated concrete frame structure with high-strength bottom bars, belonging to the technical field of concrete frame structures in construction engineering.

Background technique

Prefabricated concrete structure can greatly improve the construction capacity and construction speed, save a lot of labor, ensure the construction quality, and help meet the requirements of "four festivals and one environmental protection". It has good development prospects in the context of green building and green construction. At present, the prefabricated assembly frame structure system that can be put into application generally has problems such as high precision processing requirements, insufficient applicability, and inconvenient construction, which makes the application advantages of prefabricated assembly frame structure not obvious.

Contents of the invention

The purpose of the present invention is to overcome the bottleneck of large-scale application of existing prefabricated concrete frame structures, and provide a prefabricated concrete frame structure with high-strength bottom bars, which can reduce the accuracy requirements for the arrangement of stressed steel bars in the middle beam of prefabricated component manufacturing, and improve the prefabricated structure. The universality of the production of assembly frame structural components and the installation of on-site nodes can effectively solve the above problems.

The technical scheme adopted in the present invention is: a prefabricated concrete frame structure with high-strength bottom bars, including precast concrete columns, precast concrete beams, reinforced steel bars at the bottom of the beams, U-shaped key grooves, core beam frame vertical bars, rectangular airtight stirrups, and core beams and ordinary steel bars on the top of the beam;

The precast concrete column is configured with vertical steel bars, and the precast concrete beam is placed on the concrete protective layer of the precast concrete column to form a beam-column connection node;

The beam end of the prefabricated concrete beam has a U-shaped keyway and the stressed steel bar at the bottom of the beam adopts high-strength steel bars, and a core beam frame vertical bar is arranged in the range of the U-shaped keyway above the stressed steel bar at the bottom of the beam end, and the core beam is erected through the core beam. In the U-shaped keyway, a rectangular airtight stirrup surrounding the stressed steel bar at the bottom of the beam is added to form a core beam;

The stressed steel bar at the bottom of the beam protrudes from the beam end, and bends upward to form a hook, and the protruding part bends sideways to avoid the main reinforcement of the precast concrete column, and is anchored in the core area of the beam-column connection node;

The prefabricated concrete beam is installed with ordinary steel bars on the top of the beam, and cast-in-situ concrete together with the entire beam-column connection node area to form an assembled integral connection node.

As a preference, the stressed steel bar at the bottom of the beam adopts 600MPa grade high-strength steel bar, with a diameter of 12mm to 16mm. The high-strength steel bar extends from the top of the groove bottom plate to a certain length at the beam end, and the end is bent upward to form a hook. The high-strength steel bar at the beam end can be used Its softness starts to flexibly bend from the starting point of the U-shaped groove. During the node installation process, it can smoothly avoid the column reinforcement and anchor into the node area, which facilitates the prefabrication of the beam and the on-site node installation.

Preferably, a welded steel mesh with a skin effect is arranged in the concrete protection layer between the stressed steel bar at the bottom of the beam and the component skin, so as to improve the development of cracks in the mid-span.

As a preference, an additional straight steel bar is placed on the reasonable height of the U-shaped keyway on both sides of the beam-column connection node and the core area of the node, which strengthens the bending resistance of the beam end at the joint surface of the beam-column, so that it can realize the plastic hinge under repeated earthquake loads. move out.

Beneficial effects: (1) The present invention uses high-strength steel bars as the prefabricated concrete beams of the lower reinforced steel bars, which can reduce the amount of steel used in the beams or reduce the cross section of the beams, so as to achieve the purpose of saving materials; (2) The end of the prefabricated beams is provided with a U-shaped groove of a certain length , The concrete in the groove and the joint concrete are integrally poured, which improves the shear resistance of the beam-column joint surface. In addition, the setting of the groove can increase the length of the free bending section of the high-strength reinforcement, and it is convenient to use the softness of the small-sized high-strength reinforcement to perform interlaced bending in space. (3) Continuation of steel bars at the top of the beam, integral pouring of joint concrete, and reinforcement of the core beam part in the keyway of the beam, to achieve a strong connection node, which can fully exert and improve the seismic capacity of the frame structure.

Description of drawings

Fig. 1 is the schematic diagram of prefabricated concrete beam of the present invention;

Fig. 2 is the sectional view of Fig. 1;

Fig. 3 is a schematic diagram of connection nodes of the present invention;

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

Detailed ways

The present invention will be further described below in conjunction with the accompanying drawings.

As shown in Figures 1 and 2: prefabricated beams with high-strength bottom reinforcement prefabricated concrete frame structure, U-shaped key grooves 1 are arranged at both ends, and the stressed steel bars 2 at the bottom of the beam are made of 600MPa heat-treated ribbed high-strength small-sized 12mm, 14mm, 16mm with certain flexibility The steel bar protrudes from the beam connection end, bends upward to form a hook, and sets the core beam frame vertical bar 3 on the upper part of the high-strength bar to form the core beam, in the concrete protective layer between the stressed main bar at the bottom of the beam and the component skin Welded steel mesh 4 with skin function is arranged to improve the cracking condition in the mid-span of the beam.

As shown in Figures 3 and 4: the connection node of the precast concrete frame structure with high-strength bottom reinforcement, after the precast concrete column 5 equipped with vertical reinforcement is installed in place, the precast concrete beam 6 is hoisted and temporarily placed on the concrete protection layer of the precast concrete column 5 Above, the reinforced steel bars 2 at the bottom of the beam end are artificially bent to form a staggered arrangement according to the actual position of the vertical steel bars at the site, and extend into the node area for anchoring. A small rectangular closed stirrup 7 surrounding high-strength bars is added in the keyway of the beam section. Form the core beam 8, and then place additional straight steel bars 9 at a certain height in the U-shaped grooves on both sides of the node and in the core area of the node, insert the common steel bars 10 on the top of the beam into the stirrups of the beam, and bind and fix them, and finally pour the concrete 11 in the node area on site, Form prefabricated assembly integral beam-column connection nodes.

The embodiments of the present invention have been described in detail above in conjunction with the accompanying drawings, but the present invention is not limited to the described embodiments. For those skilled in the art, within the scope of the principles and technical ideas of the present invention, various changes, modifications, substitutions and deformations to these embodiments still fall within the protection scope of the present invention.

Claims (1)

1. A kind of 1. high-strength bottom muscle Precast Concrete Frame, it is characterised in that：Including precast concrete column, precast concrete Beam, beam bottom steel bar stress, U-shaped keyway, core roof beam structure stud, rectangular tight stirrup, core beam and back regular reinforcement；

   The precast concrete column is configured with vertical reinforcement, and the precast concrete beam is shelved on the concrete of precast concrete column On protective layer, beam-column connection is formed；

   The beam-ends of the precast concrete beam leaves U-shaped keyway and beam bottom steel bar stress uses high tensile reinforcement, the beam bottom Core roof beam structure stud is provided with the range of U-shaped keyway above steel bar stress, is set up by core roof beam structure stud in U-shaped keyway around beam The rectangular tight stirrup of bottom steel bar stress, form core beam；

   Beam bottom steel bar stress stretches out beam-ends, and bends up to form crotch upwards, and extension lateral bending avoids precast concrete Post cage bar, it is anchored in beam-column connection core space；

   The precast concrete beam installs back regular reinforcement, and together with the cast-in-place concrete of whole beam-column connection region, shape Into assembled integral connecting node；

   Beam bottom steel bar stress uses 600MPa level high tensile reinforcements, and high tensile reinforcement diameter uses 12 mm or 14mm；

   Steel bar welding of the arrangement with diaphragms effect in beam bottom steel bar stress to the concrete cover between component epidermis Net；

   Place additional straight reinforcing bar in the top of the beam-column connection both sides U-shaped keyway and joint cores.