CN111236419A - A new type of reinforced concrete structure beam-column joint and construction method - Google Patents

Abstract

The invention provides a novel beam-column joint of a reinforced concrete structure, which comprises a beam-column joint core area and a reinforced concrete ring beam, wherein the reinforced concrete ring beam is arranged around the beam-column joint core area. The beam-column joint core area comprises a main reinforcement penetrating through the joint core area in the frame column, and stirrups, reinforcing stirrups, steel plate sleeves, concrete and the like in the core area, wherein the stirrups are bound outside the main reinforcement, and the steel plate sleeves sleeved outside the stirrups are supported on the reinforcement at the bottom of the frame beam penetrating through the core area; a steel plate belt is adopted to replace part of stirrups, the distance between the stirrups is reduced, the construction measures are perfected, and the like, a space with the diameter of about 200mm is vacated in the center of a node core area, so that an operation space is provided for binding and installing the steel bars; meanwhile, the vibrating rod is convenient to insert and pull out, so that the concrete can be vibrated tightly; be in node core region concrete in the closed region of steel sheet cover can pour simultaneously with the lower post, when can easily solving the post concrete strength and be higher than the beam slab, the difficult problem of pouring of core region concrete.

Description

A new type of reinforced concrete structure beam-column joint and construction method

technical field

The invention relates to the technical field of building structure engineering, in particular to a novel reinforced concrete structure beam-column joint and a construction method.

Background technique

The quality of construction projects is related to the safety of buildings, and is closely related to the safety of people's lives and property, social harmony, stability and stability. Therefore, the construction authorities have always attached great importance to the quality management of construction projects. In recent years, with the increasing supervision of construction quality, the overall level of construction quality has steadily improved. However, in the process of housing construction in my country, many common construction quality problems still lack effective solutions.

The beam-column joint is the key part of the reinforced concrete frame structure, and it is the pivot linking the structural system, which plays a linking role. From the point of view of stress, the stress situation in the core area of beam-column joints is more complicated. It not only directly bears the pressure, shear force and bending moment from the column end of the frame, but also bears the shear force and bending moment of the beam end. During repeated earthquakes, the core concrete is in a state of complex shear-compression stress, which often results in crossed cracks in the core area, compression of column ends, spalling, and buckling of steel bars. In particular, corner columns and side columns, due to the influence of torsion and eccentricity, are subjected to more complex forces and are more likely to cause earthquake damage than inner frame columns. The previous earthquake damages show that the most serious parts of the frame structure occur in the beam-column joints with the most complex stress. Therefore, the beam-column joint is the weak link of the quality of the concrete structure, and the beam-column joint with reliable quality is the basic guarantee to ensure the safe service of the structural system.

The investigation and analysis show that the stirrups in the reinforced concrete beam-column joints are rarely placed, missing or not placed according to the design spacing requirements, and the main reinforcement bending anchors are not in place. seriously affect the quality of the structure.

For the problems existing in the construction of beam-column joints of reinforced concrete structures, the industry is not surprised. The industry believes that although the relevant specifications have detailed regulations, due to the large number of steel bars in the beam-column joint area, especially at the middle column joints, the steel bars are dense: ① In the vertical direction, the longitudinal steel bars of the frame columns pass through the core area of the node; ② In the horizontal direction, the stressed steel bars of the longitudinal and transverse frame beams pass through or are anchored to the inner side of the longitudinal steel bars of the frame columns, forming a three-dimensional cross in the shape of a zigzag; ③ In addition There are also transverse stirrups tied to the main reinforcement.

For operators who mainly work by hand, it is difficult to complete the reinforcement work that fully meets the requirements of the specification when performing reinforcement binding operations in a small space.

In summary, the lack of vertical and horizontal cross-section of steel bars in the beam-column joint area of reinforced concrete structures is the main reason for the difficulty in binding steel bars. It is also difficult to insert the vibrating rod and the concrete is not vibrated in place, resulting in insufficient concrete density in the joint area, beams and beams. The main reason why the construction quality of column joints is difficult to be guaranteed.

In addition, it is often encountered in engineering practice that the design strength of frame column concrete is two grades or more higher than the design strength of beam-slab concrete. In this regard, "Concrete Structure Engineering Construction Specification" GB50666 and "Concrete Structure Engineering Construction Quality Acceptance Specification" GB50204 both clearly stipulate that separation measures should be taken in the junction area.

At present, the following two methods are mainly used in the project to solve this problem. First, improve the strength level of beam-slab concrete, so that the difference between beam-column concrete strength level is not higher than 5Mpa. After that, with the approval of the design unit, the concrete with the same design strength grade as the beam and slab concrete is used for pouring. Using this method is bound to increase the project cost by a large margin.

Second, at a distance of 500mm from the edge of the column and not less than 1/2 the height of the frame beam, along the 45-degree slope from the top of the beam to the bottom of the beam, use steel mesh to separate the concrete of different strength grades, and pour the concrete of the frame column first. . This is feasible in theory, but due to the need of pumping in practical projects, the slump of commercial concrete is relatively large, generally 180-220mm, so it is difficult to operate in practical projects.

SUMMARY OF THE INVENTION

The technical problem to be solved by the present invention is to provide a new type of reinforced concrete with the advantages of relatively scattered reinforcement in the core area, convenient installation of reinforcement in the core area of beam-column joints, insertion of vibrating rods, vibration of concrete, and controllable construction quality. Structural beam-column connections.

The present invention is realized in this way: a novel reinforced concrete structure beam-column joint, comprising:

The beam-column node core area where the frame beam and the frame column are connected; the beam-column node core area includes the main reinforcement passing through the beam-column node core area in the frame column, the stirrups in the core area, the reinforcing stirrups, and the welded steel plates Cover, concrete; the stirrup is bound outside the main reinforcement, the steel plate sleeve is sleeved outside the stirrup, and the steel plate sleeve is also supported on the main reinforcement at the bottom of the frame beam that crosses the core area;

A reinforced concrete ring beam, the reinforced concrete ring beam surrounds the core area of the beam-column joint.

Further, the concrete strength of the described reinforced concrete ring beam is the same as the beam slab, and the height of the ring beam≥the height+50mm of the frame beam; the width of the reinforced concrete ring beam≥the width of the frame beam, and should be able to satisfy the frame beam The anchorage requirements of the main reinforcement, the anchorage of the main reinforcement of the frame beam in the ring beam shall be carried out according to the provisions of GB50010.

Further, the diameter of the main bars of the reinforced concrete ring beam is greater than or equal to B16, and the spacing is less than or equal to 200mm; when the height of the web of the ring beam is greater than or equal to 450mm, longitudinal structural steel bars (waist bars) are arranged on both sides of the ring beam along the height, the diameter is greater than or equal to B14, and the longitudinal direction of each side is The spacing of structural steel bars is ≤200mm, and the spacing between tie bars between waist bars is less than or equal to 200mm; welded joints are used for main bars and waist bars. Configure stirrup diameter ≥ A8, spacing ≤ 100mm.

Further, in the core area of beam-column joints, measures such as replacing some stirrups with steel plate sleeves, appropriately reducing the spacing of stirrups, and optimizing the structural plan of the core area of the joints are adopted. , The stirrups are installed away from the middle part of the core area to ensure that no steel bars and stirrups pass through the middle part of the cross section of the core area of the reinforced concrete beam-column joint with a diameter of about 200mm, and the vibrating rod can be inserted and pulled out without obstacles.

Further, the steel plate sleeve is formed by welding four steel plates, and the steel plate sleeve is welded with full penetration welds within the full height range; The clear distance between the beam surface reinforcement in the area is -10mm.

Further, the corner bars of the two-way frame beam and the beam side bars located in the second row cross the core area and form a whole with the reinforced concrete ring beam to enhance the ability of the core area to resist damage; After passing through the core area of the reinforced concrete beam-column joint, the beam-side reinforcement bars in the ~2 rows are anchored in the ring beam on the other side; while the non-beam-side reinforcement bars in the 1st-2nd row and the third row and above in the frame beams The steel bars are completely pierced through the reinforced concrete ring beam on the same side and then bent and anchored, which facilitates the impact of the vibrating rod to reach every corner.

Further, when the cross section of the column is changed, the main reinforcement of the lower column extends to the top of the steel plate sleeve and then is bent and anchored in the ring beam on the same side. After extending to the bottom of the steel plate sleeve, it is bent and anchored in the ring beam on the same side. The total anchorage length is ≥1.2laE, and the anchorage length of the horizontal section is ≥12d, where d is the diameter of the main reinforcement, and laE is the anchorage length of the tensile reinforcement during earthquake resistance. .

Further, at the top node, the main reinforcement of the lower column extends to the top of the steel plate sleeve and then is bent and anchored in the ring beam on the same side.

Further, reinforcing stirrups with a diameter ≥ B12 are welded at positions corresponding to the beam surface and the bottom of the beam in the core area of the beam-column node.

Further, measures such as increasing the diameter of the stirrups and appropriately reducing the spacing of the stirrups are taken in the frame column. On the premise that the distance between the stirrups meets the requirements of GB50011 of the Code for Seismic Design of Buildings, the stirrups should avoid the middle diameter of the core area. It is installed for the 200mm part, which is convenient for the vibrator to function.

If the frame column still cannot meet the shear bearing capacity requirements, the steel plate sleeve welded by the steel strip can also be used to replace part of the stirrups in the frame column. The steel plate sleeve in the frame column is also welded by four steel plates. The steel plate sleeve in the frame column adopts full penetration weld within the range of H _n /3 at the lower end of the bottom column, and adopts full penetration welding in the range of Sc at the upper end of the bottom column. For penetration welds, partial penetration welds can be used in the middle; the height of the steel plate sleeve of the bottom column = the distance from the bottom of the frame beam on the second floor to the top surface of the foundation -10mm.

The steel plate sleeves in the frame column shall adopt full penetration welds within the range of Sc at both ends of the other layers, and partial penetration welds can be used in the middle part, where _Sc≥hc , _Sc≥Hn /6, and Sc≥ 500mm, h _c is the length of the cross section of the frame column, H _n is the net height of the frame column; the height of the steel plate sleeve in the frame column = the distance from the bottom of the upper frame beam to the next floor -10mm.

The present invention has the following advantages:

(1) Set up reinforced concrete ring beams around the core area of the beam-column joint. The corner bars in the frame beams and the beam side bars in the second row pass through the core area and form a whole with the reinforced concrete ring beams to enhance the resistance of the core area to damage. In the frame beam, the non-beam side steel bars located in the 1st to 2nd rows and the steel bars on the third row and above completely pass through the reinforced concrete ring beam on the same side and then bend and anchor; at the top node, the main bars of the frame column are bent. It is folded to the ring beam on the same side and anchored, so as to avoid the crisscrossing of steel bars in the core area of the node, provide necessary operating space for the binding and installation of steel bars, and provide the necessary guarantee for improving the binding quality of steel bars in the core area of beam-column joints .

(2) In the core area of beam-column joints, measures such as replacing part of the stirrups with steel plate sleeves welded by steel strips, appropriately reducing the spacing of stirrups, and optimizing the structural plan of the core area of the joint are further improved to further improve the dense distribution of steel bars in the core area of the joint. ; On the premise that the distance between the stirrups meets the requirements of GB50011 of "Code for Seismic Design of Buildings", the stirrups should be installed away from the middle part of the core area to ensure that the middle part of the section of the core area of the reinforced concrete beam-column joint is about 200mm in diameter. The rib and main rib pass through, which is convenient for the insertion and extraction of the vibrating rod, ensuring that the effect of the vibrating rod is transmitted to every part of the core area, so that the concrete can be effectively vibrated, and the air bubbles in the concrete can be eliminated in time, which can effectively improve the concrete. density and improve the strength of concrete.

(3) Under the premise of facilitating construction, appropriately reducing the spacing of stirrups in the core area of the node, coupled with the effect of confining the concrete by the steel plate sleeve, can greatly enhance the deformation capacity of the core area and improve the seismic performance of the structure; The concrete is restrained by steel plate sleeves around it, which can avoid the risk of high-strength concrete bursting at high temperature in case of fire emergency.

(4) In the beam-column joint of the new reinforced concrete structure, the steel plate sleeves outside the stirrups enclose the core area of the beam-column joint to form a relatively closed area, which can separate the concrete in different areas. The concrete in the core area is separated from the concrete of the frame beam, so the new type of reinforced concrete beam-column joint can easily solve the construction problem when the strength of the concrete in the core area of the frame joint is higher than that of the beam-slab concrete.

(5) The implementation of the new reinforced concrete structure beam-column joint can provide the necessary guarantee for the realization of the design concept of "strong column, weak beam, stronger joint".

Description of drawings

The present invention will be further described below with reference to the accompanying drawings and embodiments.

FIG. 1 is a schematic diagram of the novel reinforced concrete frame structure according to the present invention.

Among them, _Sc≥hc , _Sc≥Hn /6, and _Sc≥500mm , hc is the length of the cross-section of the frame column, _Hn is the clear height of the frame column; S is the length of the beam end stirrup densification area, When the seismic grade is Grade 1, the length of the beam end stirrup densification area S ≥ 2.0hb (hb is the beam height) and not less than 500mm; when the seismic grade is 2 to 4, the beam end stirrup densified area length S ≥ 1.5hb ( hb is the frame beam height) and not less than 500mm, H1, H2, Hw are the structural elevations of the 2nd, 3rd and roof layers respectively.

FIG. 2 is a plan view of the beam-column joint of the novel reinforced concrete structure according to the present invention.

FIG. 3 is an elevation view of the beam-column joint of the novel reinforced concrete structure according to the present invention.

Figure 4 is a schematic diagram of the relative positional relationship between the main reinforcement of the frame beam and the main reinforcement of the reinforced concrete core area in a plane.

FIG. 5 is a schematic diagram of the section A-A in FIG. 4 , and is also a schematic diagram of the vertical relative positional relationship between the steel plate sleeve and the main reinforcement of the frame beam.

FIG. 6 is a schematic diagram of reinforcement in section B-B in FIG. 5 .

Among them, b is the width of the frame beam, and hb is the height of the frame beam.

Figure 7 is a schematic diagram 1 of the cross-section reinforcement in the reinforced concrete core area.

FIG. 8 is a schematic diagram 2 of the cross-section reinforcement in the reinforced concrete core area.

FIG. 9 is a schematic diagram 3 of the cross-section reinforcement in the reinforced concrete core area.

FIG. 10 is a schematic diagram of the reinforcement arrangement in the core area in the C-C section in FIG. 9 .

FIG. 11 is a schematic structural diagram of a steel plate sleeve 32 formed by welding steel strips.

Among them, the index number of the nock in the welding seam marking is shown in Appendix A of the National Standard Atlas 15G909-1 (the same as the rest).

Figure 12 is a schematic diagram of the anchorage structure of the main bars of the frame column in the core area of the node when the cross-section of the reinforced concrete frame column is changed.

where d is the diameter of the rebar.

Figure 13 is a schematic diagram of the anchorage of the main bars of the reinforced concrete frame column at the top edge nodes.

where d is the diameter of the rebar.

FIG. 14 is a schematic diagram of the reinforcement configuration of the reinforced concrete ring beam according to the present invention.

Where bc is the width of the frame column, hc is the section height of the frame column.

Fig. 15 is an enlarged view of the main reinforcement of the reinforced concrete ring beam according to the present invention.

FIG. 16 is a cross-sectional view of the reinforced concrete ring beam located on the left side of the core region of the node in FIG. 14 .

Fig. 17 is a plan view of reinforcement reinforcement of a reinforced concrete ring beam at a corner node of an intermediate floor.

Where bc is the width of the frame column, hc is the section height of the frame column.

Fig. 18 is a plan view of reinforcement reinforcement of a reinforced concrete ring beam at an edge node of an intermediate layer.

Where bc is the width of the frame column, hc is the section height of the frame column.

Figure 19 is a schematic diagram of the anchorage of the main reinforcement of the intermediate layer reinforced concrete frame beam in the core area of the edge node.

Figure 20 is a schematic diagram of the anchorage of the main reinforcement of the reinforced concrete frame beam in the core area of the top edge node.

Figures 21 and 22 are schematic diagrams of the anchoring structure of the main reinforcement of the frame beam in the core area of the node when the section height of the reinforced concrete frame beam is different.

where HE is the height difference between the bottom main bars of the frame beams on both sides of the core area, and Bhu is the width of the ring beam.

Figure 23 is a schematic diagram of the frame column structure, wherein Sc is the length of the column end encryption zone;

Figures 24 to 26 are schematic diagrams of cross-section reinforcement of reinforced concrete frame columns, where bc and hc are the dimensions of the short side and the long side of the frame column, respectively.

FIG. 27 is a schematic diagram of the structure of the steel plate sleeve 42 when a full penetration weld is used.

FIG. 28 is a schematic diagram of the structure of the steel plate sleeve 42 when a partial penetration weld is used.

Among them, the index number of the nock in the welding seam marking is shown in Appendix A of the National Standard Atlas 15G909-1 (the same as the rest).

Description of reference numbers:

Reinforced concrete ring beam 1, main bars 11, 12, 13, stirrups 14, beam side waist bars 15, tie bars 16, see Figure 16;

Frame beam 2, bottom corner bars 21, the second row of beam side main bars at the bottom of the beam 22, other bottom main bars 23, stirrups 24, beam face corner bars 25, beam face second row beam side main bars 26, beam surface other main bars 27; Waist tendon 28, Lajin 29, see Figures 4-6;

The beam-column joint core area 3, the main reinforcement 31, the main reinforcement 311 of the lower column, the main reinforcement 312 of the upper column, the steel plate sleeve 32 in the core area, the stirrups 33, and the reinforcement stirrups 331, 332, see Figure 5, Figure 8-12;

Frame column 4, main reinforcement 311, stirrup 41, column steel plate sleeve 42, see Figures 23 to 28;

Foundation 5.

Detailed ways

The inventive concept of the present invention is as follows:

(1) Set up reinforced concrete ring beams around the core area of the beam-column joint, and pass the main bars on the side of the frame beams that extend into the core area and have little effect on the work of the vibrating rods through the core area to form a whole with the reinforced concrete ring beams to strengthen the core area. The ability to resist damage in the core area; and the beam-column steel bars that pass through or anchor in the core area, which will hinder the insertion and extraction of the vibrating rod, are anchored in the reinforced concrete ring beam on the same side, so as to avoid the criss-crossing condition of the steel bars in the core area of the node. The binding and installation of steel bars provides necessary operation space, and provides a necessary guarantee for improving the binding quality of steel bars in the core area of beam-column joints.

(2) In the core area of beam-column joints and frame columns, steel plate sleeves are used to replace some stirrups, and the spacing of stirrups in the core area is appropriately reduced, and the reinforcement arrangement plan is optimized to further improve the dense distribution of reinforcement in the core area of the node. ; On the premise that the distance between the stirrups meets the requirements of GB50011 of the Code for Seismic Design of Buildings, the stirrups should be installed away from the middle part of the core area of about 200mm to ensure that the diameter of the middle part of the core area of the frame column and the reinforced concrete beam-column joint is about 200mm. There are no steel bars and stirrups passing through the range, which is convenient for the insertion and extraction of the vibrating rod, ensuring that the effect of the vibrating rod is transmitted to every part of the core area, so that the concrete can be effectively vibrated, and the air bubbles in the concrete can be eliminated in time. Effectively improve the compactness of concrete and increase the strength of concrete.

(3) In the beam-column joint of the new reinforced concrete structure, the core area of the beam-column joint is surrounded by welded steel plate sleeves, and the steel plate sleeve separates the concrete in different areas, that is, the concrete in the core area and the The concrete of the beam is separated, and concrete can be poured at the same time as the lower column. Therefore, the use of a new type of reinforced concrete structure beam-column joint can effectively solve the core of the beam-column joint when the design strength of the ground-column concrete is two levels or more higher than the design strength of the beam-slab concrete. To solve the problem of concrete pouring in the area, ensure that the concrete strength grade in the core area of the node is the same as that of the lower column.

See Figures 1 through 28.

Example:

A novel reinforced concrete structure beam-column joint of the present invention comprises:

(1) The core area 3 of the beam-column joint where the frame beam 2 and the frame column 4 meet, as shown in Figures 1-11. The core area 3 of the beam-column node includes the main reinforcement 31 passing through the core area 3 of the beam-column node in the frame column 4, the concrete and steel plate sleeves 32 and the stirrups 33 in the core area, and the reinforcement stirrups 331, 332, see Fig. 5 and As shown in Figure 10; when the column cross section is changed, it also includes the main reinforcement 311 of the lower column and the main reinforcement 312 of the upper column, as shown in Figure 12 for details; the stirrups 33 are bound outside the main reinforcement 31, 311, and then the stirrups The rib 33 is sheathed into the steel plate sleeve 32, and is supported on the beam side steel bar 22 passing through the core area in the two-way frame beam 2, wherein the beam side steel bar 22 is located at the beam side of the second row at the bottom of the frame beam, and is bound or passed through. The short steel bars are welded and fixed on the main bars in the core area, as shown in Figures 4 and 5 for details.

In a specific embodiment, the spacing between the stirrups 33 in the core area is less than or equal to 100 mm. Under the condition that the operating conditions are met, the spacing is as small as possible, generally 50 to 100 mm; ≥200mm, and should meet the requirements of the national standard "Code for Seismic Design of Buildings" GB50011; stirrups 33 can be in the form shown in Figures 7 to 9, and tie bars are avoided in the middle of the core area to ensure that the beam-column joints The center diameter of the core area 3 is about 200mm without stirrups and main bars passing through, as shown by the dotted circles in Figures 7 to 9, which is convenient for the insertion and extraction of the vibrating rod, and ensures that every concrete in the core area is vibrating. Within the effective radius of the action, the concrete can be effectively vibrated, and the air bubbles in the concrete can be removed in time, which can effectively improve the compactness of the concrete and increase the strength of the concrete.

The steel plate sleeve 32 in the core area is welded by four steel plates, and its large sample is shown in Figure 11; the full-penetration weld is welded within the full height of the steel plate sleeve, and the welding seam is marked with reference to the National Standard Design Atlas " Steel structure connection construction diagram "15G909-1 implementation, the height of the steel plate sleeve = the clear distance between the bottom reinforcement of the frame beam passing through the core area and the beam surface reinforcement passing through the core area -10mm; where t ₁ and t ₂ are respectively is the thickness of the steel plate strip on the two opposite sides. The strength, thickness of the steel plate and the shear bearing capacity of the joint should be calculated according to the current national standard "Building Structure Load" GB50009, "Concrete Structure Design Code" GB50010, "Steel Structure Design Standard" GB50017, "Technical Specifications for Concrete-filled Steel Tubular Structures" GB50936, "Technical Specifications for Design of Concrete Structures of High-rise Buildings" JGJ3, "Technical Specifications for Steel Structures of High-rise Civil Buildings" JGJ99 and China Engineering Construction Association Standard "Technical Specifications for Rectangular Concrete-filled Steel Tube Joints" and other regulations; The designed frame structure should still comply with the current national standard "Code for Seismic Design of Buildings" GB50011.

Reinforcing stirrups 331 are arranged outside the main bars 31 or 311 in the core area corresponding to the bottom of the frame beam, and reinforcing stirrups 332 are arranged outside the main bars 31 or 312 in the core area corresponding to the frame beam surface, as shown in FIG. 12 . Show.

When the cross-sectional dimensions of the upper and lower columns are different, the main reinforcement 311 of the lower column extends to the top of the steel plate sleeve and then bends and anchors it in the ring beam on the same side. 312 is extended to the bottom of the steel plate sleeve and then bent and anchored in the ring beam on the same side. The total anchorage length is greater than or equal to 1.2laE, and the anchorage length of the horizontal section is greater than or equal to 12d, where d is the diameter of the main reinforcement, and laE is the anchorage of the tensile reinforcement during earthquake The length and structure diagram are shown in Figure 12.

At the top node, the main reinforcement 311 of the lower column extends to the top of the steel plate sleeve and then is bent and anchored in the ring beam on the same side. The total anchorage length is ≥1.2laE and the anchorage length of the horizontal section is ≥12d.

(2) Reinforced concrete ring beam 1, the reinforced concrete ring beam 1 is set outside the core area 3 of the beam-column joint, as shown in Figures 14-18, in the specific implementation, the strength grade of the reinforced concrete ring beam 1 The same as the frame beam, it is cast in one piece with the beam plate.

In the beam-column joint of the novel reinforced concrete structure of the present invention, a reinforced concrete ring beam 1 is arranged around the core area 3 of the beam-column joint, and the corner bars 21 and 25 in the frame beam and the beam side bars 22 and 26 in the second row are connected. Passing through the core area, it forms a whole with the reinforced concrete ring beam, which enhances the ability of the core area to resist damage; while other longitudinal steel bars 23, 27, 28 are scattered and anchored in the reinforced concrete ring beam on the same side to avoid the reinforcement in the core area of the node. The criss-crossing situation provides necessary operating space for the binding and installation of steel bars, and provides a necessary guarantee for improving the binding quality of steel bars in the core area of beam-column joints, which can effectively solve the common quality problem that the construction quality of reinforced concrete frame node areas is difficult to guarantee.

In a specific embodiment, as shown in FIGS. 14-18 , the height of the reinforced concrete ring beam 1 ≥ the height of the frame beam 2 + 50 mm; the width of the reinforced concrete ring beam 1 ≥ the width of the frame beam 2 , and It should be able to meet the anchorage requirements of the main reinforcement of frame beam 2, and the anchorage of the main reinforcement of frame beam 2 in the reinforced concrete ring beam 1 shall be carried out according to the provisions of GB50010.

Reinforced concrete ring beam 1 is provided with closed welded main bars 11, 12, 13 in the upper part, and its area is not less than 0.7 times that of the upper main reinforcement of the frame beam, and closed welded main reinforcement bars 17-19 are set in the lower part, and its area is not less than 0.7 times of the lower main reinforcement of the frame beam ; The length of the main bars 13 and 19 = (bc+hc+50)*2, where bc and hc are the short and long sides of the frame column, respectively, as shown in Figures 14 to 15; the main bars 11 (17), 12 ( The distance between 18) and 13 (19) is less than or equal to 200mm; the diameter of stirrup 14 is greater than or equal to A8mm, the spacing is less than or equal to 100mm, the diameter of waist bar 15 is greater than or equal to B14, the spacing between adjacent waist bars 15 is less than or equal to 200mm, and the distance between ties 16 is less than or equal to 200mm. The spacing is less than or equal to 200mm, see Figure 16.

(3) The section size and reinforcement of the frame beam 2 shall comply with the provisions of the relevant codes and the requirements of the design documents. The position of the main reinforcement of the frame beam in the plane of the core area is shown in Figure 4, the vertical relative position of the steel plate sleeve and the main reinforcement of the frame beam in the core area is shown in Figure 5, and the schematic diagram of the cross-section reinforcement of the reinforced concrete frame beam 2 is shown in Figure 6, where b is The section width of the frame beam, hb is the section height.

The frame beam is provided with stirrup densification areas at both ends, starting from the edge of the ring beam, the length of the stirrup densification zone is S, and when the seismic grade is level 1, the length of the stirrup densification zone at the beam end is S≥2.0hb and not less than 500mm; the seismic grade When it is grade two to four, the length of the reinforced area of the stirrup at the beam end is S ≥ 1.5hb and not less than 500mm, where hb is the height of the frame beam.

The bottom corner bars 21 of the reinforced concrete frame beam 2 and the beam side bars 22 located in the second row at the bottom penetrate through the core area 3 of the reinforced concrete beam-column joint from the steel plate cover; the rest of the beam bottom bars 23 completely pass through the ring beam on the same side Bending anchorage, the total anchorage length ≥laE, of which the anchorage length of the horizontal section is ≥0.4labE; the beam surface angle bars 25 of the reinforced concrete frame beam 2 and the beam side reinforcement bars 26 of the second row pass through the reinforced concrete beam from the top of the steel plate sleeve In the core area 3 of the column node, the rest of the beam surface steel bars 27 completely pass through the ring beam on the same side and then bend and anchor. The anchorage length, labE, is the basic anchorage length of the tensile reinforcement of the main reinforcement; see Figure 5 for details.

For edge nodes with only one-sided frame beams, the bottom corner bars 21 of the reinforced concrete frame beam 2 and the beam side bars 22 of the second row at the bottom extend through the core area 3 of the reinforced concrete beam-column node to the ring beam edge anchoring on the other side. , the total anchorage length is greater than or equal to laE, and the anchorage length of the horizontal section is greater than or equal to 0.4labE; as shown in Figure 19 and Figure 20, if the anchorage length is insufficient, anchor bars with a length of 3 times the diameter of the steel bar can be welded on both sides of the end of the main bar; The beam face corner bars 25 of the reinforced concrete frame beam 2 and the beam side bars 26 of the second row are covered from the steel plate and cross the core area 3 of the reinforced concrete beam-column joint, and are bent and anchored after completely passing through the ring beam on the other side. The total anchorage length is greater than or equal to laE, and the anchorage length of the horizontal section is greater than or equal to 0.4labE; where laE is the anchorage length of the tensile reinforcement during earthquake resistance, and labE is the basic anchorage length of the tensioned reinforcement for the main reinforcement.

When the heights of the frame beams located on both sides of the core area are different, the schematic diagrams of the anchorage structure of the main reinforcement of the frame beam in the node core area are shown in Figure 21 and Figure 22; And the beam side reinforcement 22 of the second row passes through the core area and then bends upward and connects with the main reinforcement at the bottom of the beam on the other side; if HE/Bhu>1/6, then the corner reinforcement 21 at the bottom of the beam with high height and the second row The beam side reinforcement 22 passes through the core area and the ring beam on the other side and is then bent and anchored in the ring beam. The total anchorage length is ≥laE, and the anchorage length of the horizontal section is ≥0.4labE; The beam side reinforcement bars 22 of the second row extend to the steel plate sleeve and anchor in the ring beam on the same side. The total anchorage length is greater than or equal to laE, and the anchorage length of the horizontal section is greater than or equal to 0.4labE. labE is the basic anchorage length of the tensile reinforcement of the main reinforcement; HE is the positional height difference of the main reinforcement on both sides, and Bhu is the width of the ring beam.

(4) Related components

①In order to facilitate the insertion and extraction of the vibrating rod, measures such as increasing the diameter of the stirrups and appropriately reducing the spacing of the stirrups are taken in the frame column. 41 Avoid the middle part of the core area with a diameter of about 200mm and install it.

If the frame column still cannot meet the shear bearing capacity requirements after taking the above measures, the steel plate sleeve 42 welded by the steel plate strip can also be used in the frame column to replace part of the stirrups. At this time, the steel plate sleeve 42 in the frame column is also welded by _four steel plates, wherein _t3 and t4 are the thickness of the steel plate strips on the two opposite sides, respectively. The strength and thickness of the steel plate and the shear bearing capacity of the frame column are calculated. The current national standards "Building Structural Load" GB50009, "Code for Design of Concrete Structures" GB50010, "Standards for Design of Steel Structures" GB50017, "Technical Specifications for Concrete-filled Steel Tubular Structures" GB50936, "Technical Specifications for Design of Concrete Structures for High-rise Buildings" JGJ3, "High-rise Buildings Concrete Structure Design Technical Specifications" The technical regulations for steel structures of civil buildings JGJ99 and the China Engineering Construction Association standard “Technical Regulations for Rectangular Steel Tube Concrete Joints” shall be implemented; the frame structure of seismic design shall still comply with the provisions of the current national standard “Code for Seismic Design of Buildings” GB50011; The contribution of the steel plate sleeve is ignored in the calculation of the flexural bearing capacity of the column, and it is implemented in accordance with the current relevant regulations.

The steel plate sleeve 42 adopts a full penetration weld within the range of H _n /3 at the lower end of the bottom column, and the steel plate sleeve 42 adopts a full penetration weld within the range of the upper end Sc of the bottom column. The penetration weld is shown in Figure 28; the height of the steel plate sleeve 42 of the bottom column = the distance from the bottom of the frame beam on the second floor to the top surface of the foundation -10mm;

The steel plate sleeve 42 adopts full penetration welds in the range of Sc at both ends of the other layers, and can use partial penetration welds in the middle part, where _Sc≥hc , _Sc≥Hn /6, and Sc≥500mm, h _c is the length of the cross-section of the frame column, H _n is the net height of the frame column; the height of the steel plate sleeve 42 = the distance from the bottom of the upper frame beam to the next floor -10mm.

At the column end of the steel plate sleeve 42 where the full penetration weld is used, a stirrup densification area is set up, and the stirrup spacing is ≤100mm, and in other column sections, the stirrup spacing is ≤200mm, see Figure 23.

② Foundation, foundation 5 is constructed according to the actual design drawings.

Described new reinforced concrete structure beam-column joint construction method:

1) According to the requirements of the design drawings, the steel strip is processed and made, and welded into a steel plate sleeve according to the design requirements.

2) Process and manufacture annular main bars, frame beam bars, waist bars, frame column bars and stirrups, etc.

3) The construction process of the new reinforced concrete structure beam-column joint:

Floor axis positioning → draw the column edge line on the floor → weld or bind the vertical stress bar 31 or 311 of the frame column → draw the stirrup spacing line on the main bar of the column → bind the stirrup 41 of the frame column 4 → set it into the column The steel plate sleeve 42 → the reinforcing stirrups 331 in the core area 3 of the beam-column node binding → installation support, and the bottom formwork of the frame column, plate, frame beam bottom and ring beam → set into the frame beam stirrup 24 → wear the frame beam 2 Bottom reinforcement → insert the steel plate sleeve 32 on the main reinforcement 31 or 312 of the frame column 4 → install the main reinforcement, waist reinforcement and stirrups of the ring beam → wear the upper reinforcement reinforcement of the frame beam 2 → install the stirrup 33 in the core area → Set the steel plate sleeve 32 in the core area → Install the reinforcing stirrups 322 in the core area → Bind the stirrups of the frame beam 2 → Install the lateral formwork of the frame beam and the ring beam → Use the chute to cast the frame column 4 and the beam-column joint core area 3 Concrete → Concrete for frame beam slabs and ring beams.

The invention is suitable for the beam-column joints in the cast-in-place reinforced concrete frame structure system and the cast-in-place reinforced concrete frame-shear structure system.

Although the specific embodiments of the present invention have been described above, those skilled in the art should understand that the specific embodiments we describe are only illustrative, rather than used to limit the scope of the present invention. Equivalent modifications and changes made by a skilled person in accordance with the spirit of the present invention should be included within the scope of protection of the claims of the present invention.

Claims (8)

1. The utility model provides a novel reinforced concrete structure beam column node which characterized in that: comprises that

A beam-column joint core area at the joint of the frame beam and the frame column; the beam-column joint core area comprises a main rib penetrating through the beam-column joint core area in the frame column, and stirrups, reinforcing stirrups, a steel plate sleeve and concrete in the core area, wherein the stirrups are bound outside the main rib, the steel plate sleeve is sheathed outside the stirrups, and the steel plate sleeve is also supported on the main rib penetrating through the bottom of the frame beam in the core area;

the reinforced concrete ring beam surrounds the periphery of the beam column joint core area.

2. The novel beam-column joint of a reinforced concrete structure as claimed in claim 1, wherein: the concrete strength of the reinforced concrete ring beam is the same as that of the beam slab, and the height of the ring beam is more than or equal to the height of the frame beam plus 50 mm; the width of the reinforced concrete ring beam is larger than or equal to that of the frame beam, the anchoring requirement of the main reinforcement of the frame beam can be met, and the anchoring of the main reinforcement of the frame beam in the ring beam is executed according to the regulation of GB 50010.

3. The novel beam-column joint of a reinforced concrete structure as claimed in claim 2, wherein: the diameter of the main reinforcement of the reinforced concrete ring beam is more than or equal to B16, and the distance is less than or equal to 200 mm; the diameter of the stirrup is more than or equal to A8, and the distance is less than or equal to 100 mm; when the height of the web plate of the ring beam is more than or equal to 450mm, waist ribs are arranged along the height of two side surfaces of the ring beam, the diameter is more than or equal to B14, the distance between the waist ribs on each side is less than or equal to 200mm, and the space between the lacing wires between the waist ribs is less than or equal to 200 mm; the main rib and the waist rib are connected by welding.

4. The novel beam-column joint of a reinforced concrete structure as claimed in claim 1, wherein: the steel plate sleeve is formed by welding four steel plates, and full penetration welding seams are adopted for welding within the full height range of the steel plate sleeve; the height of the steel plate sleeve is equal to the clear distance between the frame beam bottom reinforcing steel bars passing through the core area and the beam surface reinforcing steel bars passing through the core area, and is-10 mm.

5. The novel reinforced concrete structure beam column node of claim 1, wherein: the angle bars in the frame beam and the beam side steel bars in the second row penetrate through the core area to form a whole with the reinforced concrete ring beam, so that the damage resistance of the core area is enhanced; the reinforcing steel bars on the non-beam side and the reinforcing steel bars on the third row and above in the 1 st-2 nd row in the frame beam completely penetrate through the reinforced concrete ring beam on the same side and then are bent and anchored; for the side frame node, after the beam side reinforcing steel bars located in the 1 st to 2 nd rows in the frame beam penetrate through the core area of the reinforced concrete beam-column node, the beam side reinforcing steel bars are anchored in the ring beam on the other side.

6. The novel reinforced concrete structure beam column node of claim 1, wherein: when the section sizes of the upper column and the lower column are different, the main ribs of the lower column extend to the top of the steel plate sleeve and then are bent and anchored in the ring beam on the same side, the anchoring total length is more than or equal to 1.2laE, and the anchoring length of the horizontal section is more than or equal to 12 d; the main reinforcement of the upper column extends to the bottom of the steel plate sleeve and then is bent and anchored in the ring beam on the same side, the anchoring total length is more than or equal to 1.2laE, the anchoring length of the horizontal section is more than or equal to 12d, wherein d is the diameter of the main reinforcement, and laE is the anchoring length of the tension reinforcement in earthquake resistance.

7. The novel reinforced concrete structure beam column node of claim 1, wherein: at the top node, the main rib of the lower column extends to the top of the steel plate sleeve and then is bent and anchored in the ring beam on the same side, the anchoring total length is more than or equal to 1.2laE, and the anchoring length of the horizontal section is more than or equal to 12 d.

8. The novel beam-column joint of a reinforced concrete structure as claimed in claim 1, wherein: and reinforcing stirrups with the diameter larger than or equal to B12mm are welded on the beam surface and the bottom of the frame beam in the beam-column joint core area.

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