CN205617560U - Beam column node of intensity prestressing tendons and regular steel bar muffjoint in breast - Google Patents

Abstract

The utility model discloses a beam-column node for connecting medium-strength prestressed tendons at the bottom of the beam with common steel bar sleeves, comprising prefabricated concrete beams, prefabricated concrete columns, medium-strength prestressed tendons, connecting sleeves, anti-seismic steel bars, and rear joint areas. Ordinary stressed steel bars at the top of cast section beams and steel bars inside columns. The bottom of the beam is only equipped with medium-strength prestressed tendons, and the prestressed tendons protrude from the end of the beam, and are connected with the anti-seismic steel bars through sleeves, and pass the post-cast concrete together with the precast concrete beam columns to form precast concrete beam-column nodes. In order to improve the energy dissipation capacity of the beam-column joint, the post-cast sections at both ends of the prefabricated beam are poured with high ultimate strain concrete. The utility model reduces the difficulty of production and construction, reduces the section height or steel consumption of the prefabricated concrete beam, and ensures the integrity and seismic performance of the beam-column joint.

Description

A beam-column joint connecting medium-strength prestressed tendons at the bottom of the beam and common steel bar sleeves

technical field

The utility model relates to a beam-column node connection structure in which medium-strength prestressed tendons at the bottom of a beam are connected with common steel bar sleeves, and belongs to the technical field of civil engineering prefabricated concrete structures.

Background technique

The frame structure is mainly constructed of beams, columns and beam-column joints, which is the most widely used structural form in construction engineering. The prefabricated prestressed concrete assembled monolithic frame structure meets the requirements of "building industrialization, housing industrialization" and green building. This type of structural system has the advantages of fast construction speed, low environmental pollution, guaranteed quality, and good durability. features.

The core technology of precast prestressed concrete assembly integral frame structure is the joint connection structure form of precast concrete beams and precast concrete columns, and its quality directly affects the ultimate bearing capacity and seismic performance of this type of structure. At present, the existing prefabricated frame structure beam-column joint connection technology is provided with keyway or U-shaped groove at the end of the beam, and is equipped with prestressed tendons and ordinary steel bars, sometimes supplemented with U-shaped steel bars, which are overlapped and anchored in the core area of the joint. In the post-casting section of the node area, the precast concrete beams and columns are formed into a whole by using concrete cast-in-place. Or use high-strength steel bars at the bottom of the beam, and place additional vertical steel bars in the core area of the joints, but there are disadvantages such as high cost, insufficient space for construction operations, and lack of ductility of the joints. Most of the above prefabricated frame beam-column joint connection technologies have problems such as insufficient applicability and inconvenient construction, which makes the application advantages of prefabricated prestressed concrete assembled integral frame structures not obvious.

How to construct a new beam-column joint connection structure with good mechanical performance, reasonable structural measures, and convenient construction has always been a technical difficulty in the precast prestressed concrete assembly integral frame structure.

Utility model content

Technical problem: The utility model provides a connection structure of prefabricated prestressed concrete assembly integral frame beam-column joints with low production difficulty, convenient construction, simple connection form and clear force.

Technical solution: The beam-column joint connecting the medium-strength prestressed tendon at the bottom of the beam and the ordinary steel bar sleeve of the utility model includes a post-casting section in the joint area, precast concrete beams arranged at both horizontal ends of the post-casting section in the joint area, and a Prefabricated concrete columns at the upper and lower ends of the post-casting section in the node area, above the precast concrete beam and the post-casting section in the node area, there is a cast-in-place area on the upper part of the composite beam, and the precast concrete column is equipped with vertical stress reinforcement in the column , the upper cast-in-place area of the composite beam is equipped with ordinary stressed steel bars, the bottom of the precast concrete beam is only equipped with medium-strength prestressed bars, and the post-cast section of the node area is equipped with stressed steel bars. The medium-strength prestressed tendons protrude from the beam end and are connected with the stressed steel bars through connecting sleeves.

Further, in the beam-column joint of the utility model, the tensile strength of the medium-strength prestressed tendons is 700MPa-1300MPa, and the total elongation of the medium-strength prestressed tendons under the maximum force is not less than 3.5%. The diameter of the medium-strength prestressed tendon is 6mm-30mm.

Further, in the beam-column joint of the present invention, in the post-casting section of the joint area, the cross-sectional area A _s of the stressed steel bar is 0.2A′ _s to 0.8A′ _s , where A′ _s is the area in the upper cast-in-place area of the composite beam The total cross-sectional area of ordinary stressed steel bars.

Further, in the beam-column joint of the utility model, the reserved length of the post-cast section in the joint area, that is, the horizontal distance between the edge of the precast concrete column and the end of the precast concrete beam is 0.5h to 2h, where h is the height of the composite concrete beam , which is the sum of the heights of the precast concrete beam and the upper cast-in-place area of the composite beam.

Beneficial effect: compared with the prior art, the utility model has the following advantages:

(1) Conventional precast concrete beams are equipped with ordinary stressed steel bars, and the spanning capacity of the beams is poor. In order to improve the spanning capacity, prefabricated prestressed concrete beams are equipped with prestressed tendons and ordinary stressed steel bars to meet the cracks of concrete beams, Tensile stress and other control requirements lead to high cost of components. In the effective cast-in-place construction space, the connection and construction work of the node area is very difficult. However, the bottom of the prefabricated beam in the utility model is only equipped with medium-strength prestressed tendons with good elongation, and does not need to be additionally equipped with ordinary steel bars, and still achieves the same bearing capacity and seismic performance as the cast-in-place concrete frame structure, reducing the prefabricated beam. The beam section or steel consumption is reduced, so that the cost and construction difficulty of the components are significantly reduced, and the purpose of material saving and high efficiency is achieved.

(2) The bottom of the prefabricated beam does not need to be equipped with ordinary stressed steel bars. On the one hand, it reduces the complexity of the core area of the precast concrete beam-column joints, which is beneficial to the lap connection between the stressed steel bars at the bottom of the beam. On the other hand, it also significantly reduces the The difficulty of making and producing precast concrete beam components improves the convenience and efficiency of on-site construction.

(3) The stressed steel bar at the bottom of the beam protrudes from the beam end and connects with the ordinary steel bar that meets the seismic requirements through a sleeve, and the beam-column joint is formed by integral casting in the core area of the joint, which is the premise of ensuring the integrity and seismic performance of the beam-column joint In this case, the connection structure is relatively simple, the force transmission method is direct, and the force is clear.

Description of drawings

Fig. 1 is a schematic diagram of the beam-column node connection between the medium-strength prestressed tendon at the bottom of the beam and the common steel bar sleeve of the utility model.

Fig. 2 is a cross-sectional view of the prefabricated concrete beam and the upper cast-in-place area of the composite beam in Fig. 1 .

Among them: 1 is the precast concrete beam, 2 is the upper cast-in-place area of the composite beam, 3 is the medium-strength prestressed tendon at the bottom of the precast concrete beam, 4 is the precast concrete column, and 5 is the post-casting section of the precast beam-column node area, 6 is the ordinary stressed steel bar at the top of the beam, 7 is the vertical stressed steel bar equipped in the precast concrete column, 8 is the connecting sleeve used to connect the medium-strength prestressed tendon on both sides of the column, 9 is connected with the sleeve and Stressed reinforcement meeting the seismic requirements, 10 is a stirrup.

detailed description

Below in conjunction with specific embodiment, and with reference to accompanying drawing, the utility model is further described:

Fig. 1 is a schematic diagram of the beam-column node connection between the medium-strength prestressed tendon at the bottom of the beam and the common steel bar sleeve of the utility model, and Fig. 2 corresponds to the cross-sectional view of the precast concrete beam and the upper part of the composite beam in Fig. 1 . As shown in Figure 1 and Figure 2, the beam-column joints connecting the medium-strength prestressed tendons at the bottom of the beam and the ordinary steel sleeves include prefabricated concrete beam 1, the upper cast-in-place area 2 of the composite beam, medium-strength prestressed tendons 3, prefabricated Concrete column 4, post-casting section in node area 5, ordinary stressed steel bar at the top of the beam 6, vertical stressed steel bar inside the column 7, connecting sleeve 8 and stressed steel bar 9 meeting the seismic requirements. The bottom of the precast concrete beam 1 is only equipped with medium-strength prestressed tendons 3, and the prestressed tendons 3 protrude from the beam end, and the connecting sleeve 8 and the stressed steel bars 9 are used to post-cast the section 5 in the node area. Internally connected, the prefabricated concrete beam 1, the medium-strength prestressed tendon 3, the precast concrete column 4, and the vertically stressed steel bar 7 in the column realize the reliable connection of the prefabricated concrete beam and the precast concrete column through post-cast concrete, and form Precast concrete beam-column joints.

As shown in Figure 1, the tensile strength of the medium-strength prestressed tendon 3 is 700MPa～1300MPa (for example, its tensile strength is 750MPa), and the total elongation under the maximum force of the medium-strength prestressed tendon 3 Not less than 3.5%, the diameter of the medium-strength prestressed tendons 3 is 6mm-30mm (for example, the diameter is 12mm). The strength of prestressed tendons is high, but the elongation is low (about 3.5%), which is much lower than that of ordinary stressed steel bars. When only prestressed tendons are configured, the seismic performance is poor, so it is usually supplemented by ordinary stressed steel bars , to improve node ductility. However, the utility model makes full use of the advantages of medium-strength prestressed tendons, avoids the configuration of ordinary stressed steel bars, and still achieves the same bearing capacity and seismic performance as the cast-in-place concrete frame structure, reducing the beam section or steel consumption of prefabricated beams , so that the cost and construction difficulty of the components are significantly reduced, and the purpose of material saving and high efficiency is achieved.

It should be pointed out that the reinforced steel bar 9 connected with the sleeve 8 in Fig. 1 and meeting the seismic requirements should not only meet the relevant performance index requirements of ordinary steel bars, but also need to meet the three requirements in terms of seismic resistance, namely: the measured resistance of the stressed steel bar 9 The ratio of the tensile strength to the measured yield strength is not less than 1.25, the ratio of the measured yield strength of the stressed steel bar 9 to the strength characteristic value of common hot-rolled steel bars is not greater than 1.30, and the maximum force total elongation of the stressed steel bar 9 is not less than 9%. .

The reserved length of the post-casting area 5 of the prefabricated beam-column joint described in Fig. 1 is 0.5h to 2h, where h is the height of the composite concrete beam. As shown in Fig. 2, the bottom of each prefabricated concrete beam 1 does not need to be equipped with ordinary stressed steel bars, and the number and strength level of the medium-strength prestressed tendons 3 are the same. The cross-sectional area A _s of the stressed steel bars 9 meeting the seismic requirements is 0.2A' _s to 0.8A' _s , wherein A' _s is the total cross-sectional area of the common stressed steel bars 6 at the top of the beam, and the number of them should be the same as the middle The strong prestressed tendon 3 is the same. When the precast concrete beam 1 is used in a high-intensity area, ordinary stress reinforcement should be provided; when the beam height is high, waist reinforcement should be provided on both sides of the beam, and the stirrups should be closed stirrups. The distribution of the strong prestressed tendons 3 at the bottom of the beam should be dispersed and symmetrical; the anchorage length and the thickness of the concrete cover should meet the relevant requirements of the current national industry standards and national specifications.

During on-site construction, after the precast concrete beam 1 and the precast concrete column 4 are hoisted in place, temporary supports and formwork are set up, and the medium-strength prestressed tendons 3 at the bottom of the beam, ordinary stressed steel bars 6 at the top, stirrup bars 10 and the inner columns The vertical stress reinforcement 7 is installed, and concrete is poured to form precast concrete beam-column joints.

The above has schematically described the utility model and its implementation, and the description is not restrictive. The accompanying drawings 1-2 are only one of the implementations of the utility model. When the connection method disclosed in the present invention is applied to more general frame structure beam-column joints, the medium-strength The number and distribution of prestressed tendons should be adjusted appropriately. Therefore, if other technicians adopt component connection methods and embodiments similar to the technical solution without departing from the inventive purpose of the present utility model, they shall all belong to the protection scope of the present utility model.

Claims (4)

1. A beam-column joint connected by medium-strength prestressed tendon and common steel bar sleeve at the bottom of the beam, characterized in that the joint comprises a post-cast section (5) in the joint area, and is arranged on a post-cast section (5) in the joint area The precast concrete beams (1) at both horizontal ends, the precast concrete columns (4) arranged at the upper and lower ends of the post-cast section (5) in the node area, and the precast concrete beam (1) and the post-cast section (5) in the node area are arranged above There is an upper cast-in-place area (2) of the composite beam, the prefabricated concrete column (4) is equipped with vertical stress steel bars (7) inside the column, and the upper cast-in-place area (2) of the composite beam is equipped with ordinary Stressed steel bars (6), the bottom of the prefabricated concrete beam (1) is only equipped with medium-strength prestressed bars (3), and the post-casting section (5) of the node area is equipped with stressed steel bars (9), so The above-mentioned medium-strength prestressed tendon (3) protrudes from the beam end, and is connected with the stressed steel bar (9) through the connecting sleeve (8). 2. The beam-to-column node where the medium-strength prestressed tendon at the bottom of the beam is connected with the ordinary steel bar sleeve according to claim 1, wherein the tensile strength of the medium-strength prestressed tendon (3) is 700MPa～1300MPa, The total elongation under the maximum force of the medium-strength prestressed tendon (3) is not less than 3.5%, and the diameter of the medium-strength prestressed tendon (3) is 6 mm to 30 mm. 3. the beam-column node that the medium-strength prestressed tendon at the bottom of the beam according to claim 1 is connected with the ordinary steel bar sleeve, it is characterized in that, in the post-casting section (5) of the node area, the stressed steel bar (9) The cross-sectional area A _s ranges from 0.2A' _s to 0.8A' _s , wherein A' _s is the total cross-sectional area of the ordinary stressed steel bar (6) in the upper cast-in-place area (2) of the composite beam. 4. according to claim 1,2 or 3 described beam bottom medium strength prestressed tendon and the beam-column node that ordinary steel bar sleeve is connected, it is characterized in that, the reserved length of post-casting section (5) of described node area , that is, the horizontal distance between the edge of the precast concrete column (4) and the end of the precast concrete beam (1) is 0.5h to 2h, where h is the height of the composite concrete beam, that is, the precast concrete beam (1) and the upper part of the composite beam are now The sum of the heights of pouring areas (2).