Prefabricated concrete frame prestressed component structure and construction method

Abstract

The invention belongs to the field of fabricated concrete frame structures, and particularly relates to a fabricated concrete frame prestressed member structure and a construction method, and the fabricated concrete frame prestressed member structure comprises a prefabricated concrete column, a prefabricated concrete beam, a post-tensioned prestressed tendon, a U-shaped steel bar I, a sleeve and a linear steel bar correspondingly matched with the sleeve. One end of the linear steel bar is connected with an in-column anchoring steel bar arranged in the precast concrete column, and the other end of the linear steel bar extends out of the sleeve arranged on the linear steel bar in a sleeving mode and is bonded with the sleeve. The closed end of the first U-shaped steel bar is arranged in the prefabricated concrete beam, and the post-tensioned prestressed tendon penetrates through the inner side of the closed end of the first U-shaped steel bar. The separated end of the first U-shaped steel bar is exposed out of the prefabricated concrete beam and matched with the concave portion on the sleeve, and the sleeve is clamped between the U-shaped steel bar and the prefabricated concrete beam. And a post-pouring layer in which the sleeve, the linear steel bar and the U-shaped steel bar I are embedded is poured on the precast concrete beam. The anti-seismic performance of the beam-column connection joint structure can be improved.

Description

Technical Field

[0001] This invention belongs to the technical field of prefabricated concrete frame structure, specifically relating to the prestressed component structure and construction method of prefabricated concrete frame. Background Technology

[0002] Prefabricated concrete frame structure systems are widely used due to their advantages such as fast construction speed and good environmental benefits. Moreover, their connection strength and seismic performance are mainly determined by the connection nodes between prefabricated components.

[0003] In existing technologies, prefabricated concrete frame structure systems mainly fall into two categories: semi-dry and dry. In dry construction systems, dry connection nodes primarily employ two methods: one involves setting energy-dissipating reinforcement bars at both the top and bottom of the precast beams; the other connects the precast beams and columns solely through post-tensioned prestressed steel reinforcement bars. While the former demonstrates excellent energy dissipation capacity during strong earthquakes, its node construction process is complex, particularly the installation of energy-dissipating reinforcement bars at the bottom of the beams, which is extremely inconvenient. The latter, although easier to construct, exhibits relatively poor energy dissipation performance during strong earthquakes and insufficient shear resistance at the nodes. Summary of the Invention

[0004] To improve the seismic performance of post-tensioned prestressed steel reinforcement connection nodes between beams and columns, this invention provides a prefabricated concrete frame prestressed member structure and construction method.

[0005] The technical solution adopted by this invention to solve its technical problem is: a precast concrete frame prestressed member structure, including precast concrete columns, precast concrete beams, and post-tensioned prestressed steel reinforcement bundles disposed between the two. It also includes multiple U-shaped steel bars fixedly pre-installed on the precast concrete beams, and at least one sleeve and straight steel bars corresponding to each sleeve.

[0006] Straight reinforcing bars extend along the length of the precast concrete beam. A sleeve is fitted over the straight reinforcing bars and bonded to them. One end of the straight reinforcing bar is fixedly connected to the precast concrete column's internal anchoring reinforcement, and the other end extends out of the sleeve.

[0007] The closed end of the U-shaped steel bar is embedded in the precast concrete beam, and the duct for passing through the post-tensioned prestressed steel bar bundle passes through the inside of the closed end of the U-shaped steel bar. The open end of the U-shaped steel bar protrudes beyond the upper surface of the precast concrete beam.

[0008] Multiple pairs of recesses are formed on the front and rear sides of the outer wall of the sleeve, arranged alternately in the axial direction. The separate ends of each U-shaped steel bar pass through the recesses and can clamp the sleeve in the middle. A post-cast layer is poured on the upper part of the precast concrete beam, embedding the sleeve, straight steel bars and the separate ends of the U-shaped steel bars inside.

[0009] Optionally, the bottom surface of the recess is arc-shaped, and the opening width of the recess is greater than the outer diameter of the U-shaped steel bar. Specifically, the opening width of the recess can be more than 1.3 times the outer diameter of the U-shaped steel bar, preferably in the range of 1.5 to 1.8 times.

[0010] The depth of the recess is less than the outer diameter of the U-shaped steel bar. Specifically, the depth of the recess can be 0.3 to 0.6 times the outer diameter of the U-shaped steel bar.

[0011] Optionally, a countersunk hole is formed at the end of the straight reinforcing bar exposed outside the sleeve, and multiple axial grooves are formed on the wall of the countersunk hole in alternating circumferential patterns. A conical body is embedded in the countersunk hole, causing the wall of the countersunk hole to expand outward into a conical shape.

[0012] Optionally, the system also includes multiple U-shaped reinforcing bars II, the same number as U-shaped reinforcing bars I, in a one-to-one matching / configuration relationship. The width of the U-shaped reinforcing bars II is greater than the width of U-shaped reinforcing bars I. The closed end of the U-shaped reinforcing bars II is also embedded in the precast concrete beam, and the open end is also exposed outside the upper surface of the precast concrete beam. The U-shaped reinforcing bars II are located away from the precast concrete column relative to their corresponding U-shaped reinforcing bars I. The exposed ends of the corresponding matching U-shaped reinforcing bars II and U-shaped reinforcing bars I can be sequentially connected to form a V-shape. The post-cast layer can also embed the open ends of the U-shaped reinforcing bars II within it.

[0013] Optionally, the separated end of the second U-shaped steel bar is located above the separated end of the first U-shaped steel bar, and the post-cast layer can embed the separated end of the second U-shaped steel bar inside it; that is, the height of the separated end of the second U-shaped steel bar is higher than the height of the separated end of the first U-shaped steel bar, and the exposed ends of each U-shaped steel bar are embedded in the post-cast layer.

[0014] Optionally, the two U-shaped steel bars are connected at their separated ends on the same side by binding steel bars.

[0015] Optionally, a fin is provided on the outer wall of the sleeve, corresponding to the side of the recess away from the precast concrete column. The fin extends obliquely away from the recess relative to the axial direction of the sleeve. An elastic deformation portion is formed at the root of the inner side of the fin. The elastic deformation portion allows the fin to elastically deform towards the outer wall of the sleeve. An annular elastic body is provided between the root of the inner side of the fin and the outer wall of the sleeve.

[0016] Optionally, the axial distance between the fin and the corresponding matching recess increases in a stepwise manner from the side closer to the precast concrete column towards the free end of the straight steel bar.

[0017] Optionally, a second fin is provided on the outer wall of the sleeve, near the inner side of the first fin, which is located close to the free end of the straight reinforcing bar. The second fin extends obliquely away from the recess relative to the axial direction of the sleeve. An elastic deformation portion two is formed at the root of the inner side of the second fin. The elastic deformation portion two allows the second fin to elastically deform in the direction closer to the outer wall of the sleeve. An elastic body is sandwiched between the first fin and the second fin.

[0018] This application also relates to a construction method based on the prestressed concrete frame structure described above, comprising the following steps: 1) According to the design plan, after installing temporary supports on the precast concrete columns, the verticality of the precast concrete columns is adjusted through the temporary supports during the hoisting process. 2) Hoist the precast concrete beam and fix it above the temporary support; 3) Install post-tensioned prestressed steel reinforcement bundles between the precast concrete columns and precast concrete beams; 4) Fill the joint between the beam and column with grout, and after the grout in the joint has reached the required strength, tension the post-stressed steel bars and fix them. 5) After installing a sleeve over the straight reinforcing bar and securing the sleeve between the separated ends of the U-shaped reinforcing bar, connect the straight reinforcing bar to the anchoring reinforcing bar inside the column. 6) After pouring, the cast layer should cover the separated ends of the sleeve, straight steel bars and U-shaped steel bars.

[0019] The beneficial effects of the present invention are as follows: The precast concrete frame prestressed member structure and construction method of the present invention can improve the current situation of insufficient seismic resistance when the precast concrete frame uses post-tensioned prestressed steel bars as prestressed member structure as beam-column joint, and help improve the energy dissipation capacity at the connection joint of precast beam and column, so that the prestressed member structure formed has good seismic resistance and collapse resistance. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the main view section structure of this application.

[0021] Figure 2 This is a top view of the structure of this application (the state when no post-cast layer is set).

[0022] Figure 3 for Figure 2 A magnified schematic diagram of the structure at point A in the middle.

[0023] Figure 4 for Figure 2 A magnified schematic diagram of the structure at point B in the middle.

[0024] Figure 5This is a structural schematic diagram of the end of the shear reinforcement.

[0025] In the diagram: 100 Precast concrete column, 101 Duct 1, 102 Anchored steel bar inside the column; 200 Precast concrete beam, 201 Duct 2; 300 Post-cast layer; 10 Post-tensioned prestressed steel bar bundle; 20 U-shaped steel bar 1; 30 Sleeve, 31 Recess, 32 Wing 1, 321 Elastic deformation part 1, 33 Elastic body, 34 Wing 2, 341 Elastic deformation part 2; 40 Straight steel bar, 41 Countersunk hole, 42 Axial groove; 50 Mechanical connector; 60 Grouting adhesive; 70 U-shaped steel bar 2; 80 Binding steel bar. Detailed Implementation

[0026] The structures, proportions, and sizes illustrated in the accompanying drawings are merely for illustrative purposes and to aid those skilled in the art in understanding and reading the invention. They are not intended to limit the scope of the invention and therefore have no substantial technical significance. Any modifications to the structure, changes in proportions, or adjustments to size, provided they do not affect the effectiveness or purpose of the invention, should still fall within the scope of the technical content disclosed herein. Furthermore, terms such as "upper," "lower," "front," "rear," and "middle" used in this specification are merely for clarity and not intended to limit the scope of the invention. Changes or adjustments to their relative relationships, without substantially altering the technical content, should also be considered within the scope of the invention's implementation.

[0027] like Figures 1 to 5 The precast concrete frame prestressed member structure shown includes a precast concrete column 100, a precast concrete beam 200, a post-tensioned prestressed steel bar bundle 10 disposed between the precast concrete column 100 and the precast concrete beam 200, a plurality of U-shaped steel bars 20 fixedly pre-set on the precast concrete beam 200, and at least one sleeve 30 and straight steel bars 40 corresponding to the sleeve 30.

[0028] The straight reinforcing bar 40 extends along the length of the precast concrete beam 200. The sleeve 30 is fitted over the straight reinforcing bar 40 and bonded to it. One end of the straight reinforcing bar 40 is fixedly connected to the column anchoring reinforcing bar 102 pre-installed in the precast concrete column 100 via a mechanical connector 50, and the other end extends out of the sleeve 30. The mechanical connector 50 can be a stud sleeve commonly used to connect the ends of two reinforcing bars.

[0029] The closed end of the U-shaped steel bar 20 is embedded in the precast concrete beam 200, and the duct through which the post-tensioned prestressed steel bar bundle 10 passes (i.e., duct 201 shown in the figure) passes through the closed end of the U-shaped steel bar 20. That is, when the post-tensioned prestressed steel bar bundle 10 extends from the duct 201 on one side of the precast concrete beam 200 (the precast concrete column 100) into the duct 101 on the precast concrete column 100, and extends into the duct 201 on the other side of the precast concrete column 100, it can sequentially pass through the closed ends of each of the U-shaped steel bars 20 on both sides (i.e., the post-tensioned prestressed steel bar bundle 10 is placed in the notch of the U-shaped steel bar 20), as shown in the figure. Figure 1 .

[0030] The separated end of the U-shaped steel bar 20 (extending upwards) protrudes beyond the upper surface of the precast concrete beam 200.

[0031] Multiple pairs of recesses 31, arranged alternately in the axial direction, are formed on the front and rear sides of the outer wall of the sleeve 30. The separate ends of each U-shaped steel bar 20 pass upward through the recesses 31 and can clamp the sleeve 30 in the middle. A post-cast layer 300 is poured on the upper part of the precast concrete beam 200, which can embed the sleeve 30, the straight steel bar 40, and the separate ends of the U-shaped steel bars 20 inside it. The bottom surface of the recess 31 is an arc-shaped bottom surface that extends in the axial direction.

[0032] When the bottom surface of the recess 31 is arc-shaped, the opening width of the recess 31 (a dimensional parameter in the axial direction of the sleeve 30) is greater than the outer diameter of the U-shaped steel bar 20. Specifically, the opening width of the recess 31 can be 1.5 to 1.8 times the outer diameter of the U-shaped steel bar 30. The depth of the recess 31 (a dimensional parameter in the radial direction of the sleeve 30) can be 0.3 to 0.6 times the outer diameter of the U-shaped steel bar 20.

[0033] In the above technical solution, the U-shaped steel bar 20 can be used to combine the precast concrete beam 200 and the post-cast layer 300 into a whole, forming a complete force system, which can effectively improve the shear resistance of the beam structure; at the same time, the two free ends of the U-shaped steel bar 20 can clamp the sleeve 30 in the middle, so that the upper part of the U-shaped steel bar 20 can establish a mechanical connection with the sleeve 30 through the recess 31. In the event of a strong earthquake, it can dissipate seismic energy through friction and elastic deformation, thereby improving the earthquake resistance performance of the connection node structure between beam and column (i.e., precast concrete column 100 and precast concrete beam 200).

[0034] The gap between the joint surfaces of the precast concrete column 100 and the precast concrete beam 200 is filled with grouting adhesive 60 to achieve good sealing and waterproofing.

[0035] like Figure 5 As shown, a countersunk hole 41 is provided at the end of the straight reinforcing bar 40 that is exposed outside the sleeve 30, and multiple axial grooves 42 are formed on the wall of the countersunk hole 41, which are distributed alternately around the circumference. A conical body (not shown in the figure) is embedded in the countersunk hole 41, so that the wall (outer circumferential surface) of the countersunk hole 41 is expanded into a conical shape (outer conical surface) (larger diameter end facing outward), making it less likely for the straight reinforcing bar 40 to detach from the sleeve 30 in the event of a strong earthquake, thereby increasing the safety of the beam-column connection structure and making the beam less likely to collapse.

[0036] The technical solution of this application also includes a plurality of U-shaped reinforcing bars 20, with the number of each U-shaped reinforcing bar 20 corresponding to that of the U-shaped reinforcing bars 20. Each U-shaped reinforcing bar 20 is matched with one U-shaped reinforcing bar 20. The width of each U-shaped reinforcing bar 20 is greater than the width of each U-shaped reinforcing bar 20, and the closed end of each U-shaped reinforcing bar 200 is embedded in the precast concrete beam 200, while the open end protrudes beyond the upper surface of the precast concrete beam 200. The location of each U-shaped reinforcing bar 20 is further away from the precast concrete column 100 than the location of its corresponding U-shaped reinforcing bar 20. The exposed ends of the corresponding U-shaped reinforcing bars 20 and 20 can be sequentially connected to form a V-shape. The separated end of the second U-shaped steel bar 70 is located above the separated end of the first U-shaped steel bar 20, and the post-cast layer 300 can embed the separated end of the second U-shaped steel bar 70 inside it.

[0037] like Figures 2 to 4 As shown, the U-shaped steel bar 20 and the U-shaped steel bar 70, corresponding to the matching U-shaped steel bar 1, are connected at their separated ends on the same side by a binding steel bar 80. To fully demonstrate the contact matching state between the recess 31 and the end of the U-shaped steel bar 20, in... Figure 2 , Figure 4 The fact that the binding steel bars 80 are not fully tied between the separated ends of the U-shaped steel bar 20 and the U-shaped steel bar 70 on the right side of the scheme shown does not mean that the binding steel bars 80 are not required between the separated ends of this part.

[0038] In actual construction, after the sleeve 30 is clamped between the separated ends of the U-shaped steel bar 20, a force is applied to the free / separated ends of the U-shaped steel bar 20 to bring the two free ends closer together, thereby increasing the firmness of the U-shaped steel bar 20 in fixing the sleeve 30. Simultaneously, a force can be applied to the separated ends of the U-shaped steel bar 70 to move the two separated / free ends away from each other, and then the separated ends of the U-shaped steel bar 20 and the U-shaped steel bar 70 are connected by the binding steel bar 80. This operation applies elastic prestress to the separated ends of the U-shaped steel bar 20, thereby improving the energy dissipation effect between the U-shaped steel bar 20 and the sleeve 30, and enhancing the ability to dissipate seismic energy.

[0039] like Figures 2 to 4 As shown, fins 32 are provided on the outer wall of the sleeve 30, corresponding to the side of the recess 31 away from the precast concrete column 100. The fins 32 extend obliquely away from the recess 31 relative to the axial direction of the sleeve 30. An elastic deformation portion 321 is formed at the root of the inner surface of the fin 32. The elastic deformation portion 321 allows the fin 32 to elastically deform towards the outer wall of the sleeve 30. An annular elastic body 33 is provided between the root of the inner surface of the fin 32 and the outer wall of the sleeve 30.

[0040] The free end of the fin plate 32 is further outward / farther from the axis of the sleeve 30 in the radial direction relative to the separated end of the U-shaped steel bar 20, see [reference]. Figure 3 , Figure 4 In this way, the wing plate 32 can mechanically block the end of the U-shaped steel bar 20 when the separating end of the U-shaped steel bar 20 slides out of the recess 31, thereby preventing the beam from completely separating from the column and better suppressing the collapse.

[0041] The elastic body 33 is sleeved outside the sleeve 30 and inserted into the acute angle at the root of the fin 32, filling the elastic deformation portion 321 and preventing it from being filled with cement. The elastic body 33 provides sufficient elastic deformation space for the elastic deformation portion 321, enabling it to function normally and fully in terms of energy dissipation and collapse prevention during strong earthquakes.

[0042] To further optimize the collapse resistance of the fin plate 32, the axial distance between the fin plate 32 and the corresponding matching recess 31 increases in a stepped manner from the side closer to the precast concrete column 100 towards the free end of the straight steel bar 40. (See [reference needed]). Figure 4 .

[0043] To further optimize the collapse resistance of this application. For example... Figure 3 , Figure 4 As shown, a second fin 34 is provided on the inner side of the first fin 32, located on the outer wall of the sleeve 30 near the free end of the straight reinforcing bar 40. The second fin 34 extends obliquely away from the recess 31 relative to the axial direction of the sleeve 30, that is, the oblique extension directions of the first fin 32 and the second fin 34 are basically the same. An elastic deformation portion 341 is formed at the root of the inner side of the second fin 34. The elastic deformation portion 341 allows the second fin 34 to elastically deform in a direction closer to the outer wall of the sleeve 30. The thickness of the second fin 34 is less than the thickness of the first fin 32. The elastic body 33 is sandwiched between the first fin 32 and the second fin 34.

[0044] The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the invention. Many aspects of the present invention can be improved without departing from the overall concept. Those skilled in the art can modify or change the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or changes made by those skilled in the art without departing from the spirit and technical concept disclosed in the present invention should still be covered by the claims of the present invention.

Claims

1. A precast concrete frame prestressed member structure, comprising precast concrete columns (100), precast concrete beams (200), and post-tensioned prestressed steel reinforcement bundles (10) disposed between the two; characterized in that: It also includes multiple U-shaped steel bars (20) fixed on the precast concrete beam (200), and at least one sleeve (30) and straight steel bars (40) that correspond one-to-one with the sleeve (30). The straight reinforcing bar (40) extends along the length of the precast concrete beam (200); the sleeve (30) is fitted over the straight reinforcing bar (40) and bonded to it; one end of the straight reinforcing bar (40) is fixedly connected to the column anchoring reinforcing bar (102) pre-installed in the precast concrete column (100), and the other end extends out of the sleeve (30); The closed end of the U-shaped steel bar (20) is embedded in the precast concrete beam (200), and the duct for passing through the post-tensioned prestressed steel bar bundle (10) passes through the closed end of the U-shaped steel bar (20); the open end of the U-shaped steel bar (20) is exposed outside the upper surface of the precast concrete beam (200). Multiple pairs of recesses (31) are formed on the front and rear sides of the outer wall of the sleeve (30) and are distributed axially. The separate ends of each U-shaped steel bar (20) pass through the recesses (31) and can hold the sleeve (30) in the middle. A post-cast layer (300) is poured on the upper part of the precast concrete beam (200) to embed the sleeve (30), the straight steel bar (40) and the separate ends of the U-shaped steel bar (20) inside.

2. The precast concrete frame prestressed member structure according to claim 1, characterized in that: The bottom surface of the recess (31) is arc-shaped, and the opening width of the recess (31) is greater than the outer diameter of the U-shaped steel bar (20).

3. The precast concrete frame prestressed member structure according to claim 1 or 2, characterized in that: The depth of the recess (31) is less than the outer diameter of the U-shaped steel bar (20).

4. The precast concrete frame prestressed member structure according to claim 1, characterized in that: A countersunk hole (41) is provided at one end of the straight steel bar (40) that is exposed outside the sleeve (30), and multiple axial grooves (42) are formed on the wall of the countersunk hole (41) in alternating circumference; a conical body is embedded in the countersunk hole (41) so that the wall of the countersunk hole (41) expands outward into a conical shape.

5. The precast concrete frame prestressed member structure according to claim 1, characterized in that: It also includes multiple U-shaped steel bars II (70) with the same number as U-shaped steel bar I (20); the width of U-shaped steel bar II (70) is greater than the width of U-shaped steel bar I (20); the closed end of U-shaped steel bar II (70) is embedded in the precast concrete beam (200), and the separated end is exposed outside the upper surface of the precast concrete beam (200); U-shaped steel bar II (70) is far away from the precast concrete column (100) relative to its corresponding U-shaped steel bar I (20); the exposed ends of the corresponding matching U-shaped steel bar II (70) and the exposed ends of U-shaped steel bar I (20) can be connected in sequence to form a V shape.

6. The precast concrete frame prestressed member structure according to claim 5, characterized in that: The separated end of the second U-shaped steel bar (70) is located above the separated end of the first U-shaped steel bar (20), and the post-cast layer (300) can embed the separated end of the second U-shaped steel bar (70) inside it.

7. The precast concrete frame prestressed member structure according to claim 6, characterized in that: Between the corresponding matching U-shaped steel bar 1 (20) and U-shaped steel bar 2 (70), the separated ends on the same side are connected by binding steel bar (80).

8. The precast concrete frame prestressed member structure according to claim 1, characterized in that: On the outer wall of the sleeve (30), and on the side of the recess (31) away from the precast concrete column (100), there is a fin plate (32); the fin plate (32) extends obliquely away from the recess (31) relative to the axial direction of the sleeve (30); an elastic deformation part (321) is formed at the root of the inner side of the fin plate (32); the elastic deformation part (321) can make the fin plate (32) elastically deform in the direction close to the outer wall of the sleeve (30); an annular elastic body (33) is provided between the root of the inner side of the fin plate (32) and the outer wall of the sleeve (30).

9. The precast concrete frame prestressed member structure according to claim 8, characterized in that: On the outer wall of the sleeve (30), a second wing (34) is provided near the inner side of a wing plate (32) located close to the free end of a straight steel bar (40); the second wing (34) extends obliquely away from the recess (31) relative to the axial direction of the sleeve (30); an elastic deformation part (341) is formed at the root of the inner side of the second wing (34); the elastic deformation part (341) enables the second wing (34) to undergo elastic deformation in the direction close to the outer wall of the sleeve (30); an elastic body (33) is sandwiched between the first wing (32) and the second wing (34).

10. A construction method for the precast concrete frame prestressed member structure according to claim 1, comprising the following steps: 1) According to the design plan, after installing temporary supports on the precast concrete column (100), the precast concrete column (100) is hoisted. During the hoisting process, the verticality of the precast concrete column (100) is adjusted by the temporary supports. 2) Hoist the precast concrete beam (200) and fix it above the temporary support; 3) Install post-tensioned prestressed steel reinforcement bundles (10) between the precast concrete column (100) and the precast concrete beam (200). 4) Fill the beam-column joint with grout (60), and after the grout in the beam-column joint reaches the required strength, tension the post-stressed steel reinforcement bundles (10) and fix them; Its characteristic is that... It also includes the following steps: 5) After installing a sleeve (30) over the straight steel bar (40) and clamping the sleeve (30) between the separated ends of the U-shaped steel bar (20), connect the straight steel bar (40) to the anchoring steel bar (102) inside the column. 6) After pouring the post-cast layer (300), the sleeve (30), straight steel bar (40) and U-shaped steel bar (20) will be completely covered.

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