Prestressed reinforcement sleeve grouting lap joint

Abstract

The utility model discloses a prestressed reinforcement sleeve grouting lap joint, and belongs to the technical field of fabricated buildings. Comprising a sleeve, and a grouting hole and a grout outlet are formed in the sleeve; a prestressed reinforcement penetrates through the sleeve, one end of the prestressed reinforcement is a prestressed reinforcement upsetting end, and a base plate is arranged between the prestressed reinforcement upsetting end and the outer wall of the sleeve; the upsetting ends of the prestressed reinforcements are tightly attached to the base plates, and the base plates are tightly attached to the outer walls of the sleeves; the other ends of the prestressed reinforcements extend out of the sleeves to be connected with tensioning equipment; according to the utility model, the bearing capacity is improved, cracks are reduced, the stress concentration phenomenon is reduced, and the problems of weak sleeve constraint capacity and unreliable force transmission existing in the existing assembly type component connection are solved.

Description

Technical Field

[0001] The utility model belongs to the technical field of assembled buildings, in particular to a prestressed steel bar sleeve grouting lap joint. Background Art

[0002] Prefabricated buildings are a fast, efficient and environmentally friendly construction method and have been widely used. However, there are several problems with the steel sleeve grouting connection in prefabricated concrete structures:

[0003] 1. Large-size sleeves have weak restraint capabilities:

[0004] The steel sleeve grouting lap joint uses a large-sized sleeve. The sleeve has a large size, a large inner diameter, and a large internal space. The steel bar is easy to insert into the sleeve, which is convenient for construction. However, as the sleeve size increases, the sleeve's restraint ability on the grouting material decreases significantly, and the bonding strength between the steel bar and the grouting material decreases. Existing technical measures cannot effectively solve this problem:

[0005] One of the existing methods is to reduce the inner diameter of the sleeve to enhance the restraint of the sleeve on the grouting material. However, this requires precise positioning of the component production, hoisting and installation during the construction process, and the allowable error is at the millimeter level, which causes great inconvenience to the on-site construction dominated by manual labor.

[0006] The second existing method is to increase the wall thickness of the sleeve to improve the restraint of the sleeve on the grouting material. As the sleeve wall thickness increases, the sleeve restraint capacity will be enhanced to a certain extent, but as the wall thickness continues to increase, the sleeve restraint capacity is not significantly improved.

[0007] 2. Unreliable force transmission caused by grouting defects:

[0008] The steel sleeve grouting joint is prone to loose grouting. If the grouting is loose, the space inside the sleeve is not filled with grouting material, which will reduce the sleeve's restraint ability, and then reduce the friction and mechanical bite force between the steel bar and the grouting material, and the reliable force transmission of the joint cannot be guaranteed. The mechanical properties of the lap joint are unstable, leaving a great safety hazard. Utility Model Content

[0009] The utility model overcomes the shortcomings of the prior art and proposes a prestressed steel bar sleeve grouting lap joint to solve the problems of weak restraint force of the prior sleeve and unreliable force transmission after grouting.

[0010] In order to achieve the above purpose, the utility model is implemented through the following technical solutions.

[0011] A prestressed steel bar sleeve grouting lap joint comprises a sleeve, on which a grouting hole and a grout outlet hole are opened; a prestressed steel bar is connected through the sleeve, one end of the prestressed steel bar is a prestressed steel bar butt end, and a pad is arranged between the prestressed steel bar butt end and the sleeve outer wall; the prestressed steel bar butt end and the pad, as well as the pad and the sleeve outer wall, are tightly fitted; the other end of the prestressed steel bar extends out of the sleeve for connecting a tensioning device.

[0012] Furthermore, the prestressed steel bar passes through the center point of the sleeve and is perpendicular to the axis of the sleeve.

[0013] Furthermore, prestressed tendon holes are provided on the front and rear walls of the sleeve, and the prestressed steel bars pass through the prestressed tendon holes.

[0014] Furthermore, the outer wall of the prestressed steel bar is sheathed with a polyethylene plastic sleeve.

[0015] Furthermore, the prestressed steel bars are coated with protective grease.

[0016] Furthermore, the sleeve is a cylindrical structure or an elliptical cylindrical structure.

[0017] Furthermore, the grouting hole is opened at the lower end of the sleeve, and the grouting hole is opened at the upper end of the sleeve.

[0018] Furthermore, the reserved steel bars are spot welded on the inner wall of the sleeve, and then the steel bars are inserted and placed in the sleeve.

[0019] Furthermore, the tensioning equipment includes a conical anchor and a jack, and the conical anchor is connected to the prestressed steel bar.

[0020] Furthermore, the conical anchor includes an anchor ring and an anchor plug.

[0021] The beneficial effects of the utility model compared with the prior art are:

[0022] 1. Improve the bearing capacity: Applying prestress can significantly increase the bearing capacity of the joint. By applying prestress to the sleeve, the restraining effect of the sleeve on the grouting material can be greatly enhanced, thereby greatly improving the friction and mechanical bite force between the steel bar and the grouting material, making the joint force transmission reliable and increasing the safety of the prefabricated component connection.

[0023] 2. Reduce cracks and stress concentration: Prestressing helps reduce cracks and stress concentration in the grouting material in the sleeve. By applying prestress to the sleeve, lateral restraint is provided to the grouting material, thereby reducing cracks in the grouting material caused by tensile stress in actual use and reducing splitting cracks in the grouting material.

[0024] 3. Improved durability: The application of prestress reduces cracks in the grouting material inside the sleeve and cracks in the concrete outside the sleeve, thereby reducing the penetration of moisture and harmful substances, and improving the durability of the component and the corrosion resistance of the sleeve.

[0025] 4. Reduce material consumption: As the application of prestressing improves the bonding performance between the steel bar and the grouting material, the length of the steel sleeve can be reduced, the wall thickness of the steel sleeve can be reduced, and the amount of steel required can be reduced. The reduction in the volume of the sleeve will also reduce the amount of grouting material used, thereby saving costs.

[0026] 5. Improve the overall safety of the structure: The application of prestress can improve the performance of component connections under extreme loads (such as earthquakes and wind loads) and improve the overall safety of prefabricated assembly results.

[0027] 6. Simple structure and convenient construction: The utility model has a simple structure and is convenient to construct, and can solve the problems of weak sleeve constraint ability and unreliable force transmission in the existing prefabricated component connections. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 is a cross-sectional view of the grouting lap joint described in Example 1;

[0029] Figure 2 is a top view of the grouting lap joint described in Example 1;

[0030] Figure 3 is a front view of the grouting lap joint described in Example 1;

[0031] Figure 4 is a rear view of the grouting lap joint described in Example 1;

[0032] Figure 5 It is a schematic diagram of the structure of prestressed steel bars;

[0033] Figure 6 is a schematic diagram of the structure of a conical anchor;

[0034] Figure 7 A side view of the grouting lap joint described in Example 1 Figure 1 ;

[0035] Figure 8 A side view of the grouting lap joint described in Example 1 Figure 2 ;

[0036] Fig. 9 is a cross-sectional view of the grouting lap joint described in Example 2;

[0037] Fig.10 is a top view of the grouting lap joint described in Example 2;

[0038] Fig.11 is a front view of the grouting lap joint described in Example 2;

[0039] Fig.12 is a rear view of the grouting lap joint described in Example 2;

[0040] Fig.13 A side view of the grouting lap joint described in Example 2 Figure 1 ;

[0041] Fig.14 A side view of the grouting lap joint described in Example 2 Figure 2 ;

[0042] In the figure:

[0043] 1-reserved steel bars, 2-later inserted steel bars, 3-sleeves, 4-grouting holes, 5-grouting holes, 6-prestressed tendon holes, 7-prestressed steel bars, 8-prestressed steel bar pier thick ends, 9-polyethylene plastic sleeves, 10-pads, 11-conical anchors, 71-protective grease, 111-anchor rings, 112-anchor plugs. DETAILED DESCRIPTION

[0044] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present invention more clearly understood, the present invention is further described in detail in combination with the embodiments and the accompanying drawings. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention. The technical solution of the present invention is described in detail below in combination with the embodiments and the accompanying drawings, but the scope of protection is not limited thereto.

[0045] Example 1

[0046] like Figure 1-8 As shown, this embodiment provides a prestressed steel bar sleeve grouting lap joint, including a cylindrical sleeve 3, on which a grouting hole 4 and a grouting hole 5 are provided; the grouting hole 4 is provided at the lower end of the sleeve 3, and the grouting hole 5 is provided at the upper end of the sleeve 3. A prestressed steel bar 7 is connected through the sleeve 3, one end of the prestressed steel bar 7 is a prestressed steel bar butt end 8, and a pad 10 is provided between the prestressed steel bar butt end 8 and the outer wall of the sleeve 3; the prestressed steel bar butt end 8 and the pad 10, as well as the pad 10 and the outer wall of the sleeve 3 are tightly fitted; the other end of the prestressed steel bar 7 extends out of the sleeve 3 for connecting the tensioning equipment.

[0047] Specifically, the front and rear walls of the sleeve 3 are provided with prestressed tendon holes 6, and the prestressed steel bars 7 pass through the prestressed tendon holes 6. The prestressed steel bars 7 pass through the center point of the sleeve 3 and are perpendicular to the axis of the sleeve 3.

[0048] Specifically, the prestressed steel bar 7 is coated with protective grease 71. The outer wall of the prestressed steel bar 7 is sheathed with a polyethylene plastic sleeve 9.

[0049] A reserved steel bar 1 is spot welded on the inner wall of the sleeve 3, and a rear inserted steel bar 2 is placed in the sleeve 3.

[0050] Specifically, the tensioning device includes a conical anchor 11 and a jack, wherein the conical anchor 11 is connected to the prestressed steel bar 7. The conical anchor 11 includes an anchor ring 111 and an anchor plug 112.

[0051] The specific steps are:

[0052] Step 1: The prestressed steel bar 7 is made of φ15 finely rolled threaded steel bar, brand PSB500; one end of the prestressed steel bar 7 is pre-upset with a steel bar upsetting machine to increase the diameter of the prestressed steel bar in the processing section, forming a prestressed steel bar pier end 8; the prestressed steel bar 7 is coated with a prestressed steel bar coating layer, and the prestressed steel bar coating layer uses professional anti-corrosion protective grease 71, and complies with the "Technical Code for Unbonded Prestressed Concrete Structures" JGJ92-2016;

[0053] Step 2: Put the polyethylene plastic sleeve 9 on the prestressed steel bar 7, then pass it through the prestressed steel bar hole 6 and place it in the sleeve 3; make the prestressed steel bar pier end 8 close to the pad 10;

[0054] Step 3: spot weld the reserved steel bar 1 to both ends of the sleeve 3 to fix the position of the reserved steel bar 1; then place the rear inserted steel bar 2 in the sleeve 3;

[0055] Step 4: Inject grouting material from the grouting hole 4, and stop grouting when qualified grout overflows from the grouting hole 5.

[0056] Step 5: Maintenance.

[0057] Step 6: After the strength of the grouting material inside the sleeve 3 reaches 75% of the design strength, install the tensioning equipment. The tensioning equipment type is a conical anchor 11, which complies with the "Technical Specification for Application of Anchors, Clamps and Connectors for Prestressed Reinforcement" JGJ85-2010;

[0058] Step 7: Before tensioning, cut off the exposed plastic sleeve and clean the grease, and install the conical anchor 11 and the jack at the end of the prestressed steel bar 7. The tensioning construction technology should comply with the relevant requirements of the Technical Code for Unbonded Prestressed Concrete Structures JGJ / T92-2016.

[0059] Step 8: Apply prestressing force by post-tensioning method without bonding. And tension the prestressed steel bar 7. Use one-end tensioning method to tension the prestressed steel bar 7. When tensioning, ensure that the tensioning action line coincides with the center of the prestressed steel bar 7; when tensioning, hold the load for 2 minutes after reaching the controlled stress before returning the oil and removing the pump. Lock the working anchor, remove the tool anchor and jack, and ensure that the exposed length of the steel bar is not less than 30mm (anti-slip design).

[0060] Step 9: Pressurize and measure.

[0061] Step 10: Anti-corrosion of anchors and prestressed bars, pouring anchor concrete. The strength grade of anchor concrete shall not be lower than the strength grade of concrete in the corresponding sleeve, and shall not be less than C40.

[0062] Example 2

[0063] See also Figure 9-14 ,as well as Figure 5 and Figure 6 The difference between this embodiment and embodiment 1 is that the structure of the sleeve 3 is an elliptical cylinder, and a reserved steel bar 1 is spot-welded on both sides of the prestressed steel bar 7 in the sleeve 3, and a steel bar 2 is inserted next to each reserved steel bar 1. The rest of the structure and working principle are the same as those in embodiment 1.

[0064] The above content is a further detailed description of the utility model in combination with a specific preferred implementation method. It cannot be determined that the specific implementation methods of the utility model are limited to this. For ordinary technicians in the technical field to which the utility model belongs, they can make several simple deductions or substitutions without departing from the utility model, which should be regarded as belonging to the utility model and the scope of patent protection determined by the submitted claims.

Claims

1. A prestressed steel bar sleeve grouting lap joint, comprising a sleeve (3), the sleeve (3) being provided with a grouting hole (4) and a grout outlet hole (5); characterized in that: A prestressed steel bar (7) is connected through the sleeve (3); one end of the prestressed steel bar (7) is a prestressed steel bar butt end (8); a pad (10) is provided between the prestressed steel bar butt end (8) and the outer wall of the sleeve (3); the prestressed steel bar butt end (8) and the pad (10), as well as the pad (10) and the outer wall of the sleeve (3), are tightly fitted; the other end of the prestressed steel bar (7) extends out of the sleeve (3) for connection to a tensioning device.

2. A prestressed steel sleeve grouting lap joint according to claim 1, characterized in that: The prestressed steel bar (7) passes through the center point of the sleeve (3) and is perpendicular to the axis of the sleeve (3).

3. A prestressed steel sleeve grouting lap joint according to claim 1 or 2, characterized in that: Prestressed tendon holes (6) are provided on the front and rear walls of the sleeve (3), and prestressed steel bars (7) pass through the prestressed tendon holes (6).

4. A prestressed steel sleeve grouting lap joint according to claim 1, characterized in that: The outer wall of the prestressed steel bar (7) is sheathed with a polyethylene plastic sleeve (9).

5. A prestressed steel sleeve grouting lap joint according to claim 4, characterized in that: The prestressed steel bar (7) is coated with protective grease (71).

6. A prestressed steel sleeve grouting lap joint according to claim 1, characterized in that: The sleeve (3) is a cylindrical structure or an elliptical cylindrical structure.

7. A prestressed steel sleeve grouting lap joint according to claim 1, characterized in that: The grouting hole (4) is provided at the lower end of the sleeve (3), and the grouting hole (5) is provided at the upper end of the sleeve (3).

8. The prestressed steel sleeve grouting lap joint according to claim 1, characterized in that: The reserved steel bar (1) is spot welded on the inner wall of the sleeve (3), and then the steel bar (2) is inserted and placed in the sleeve (3).

9. The prestressed steel sleeve grouting lap joint according to claim 1, characterized in that: The tensioning device comprises a conical anchor (11) and a jack, wherein the conical anchor (11) is connected to the prestressed steel bar (7).

10. A prestressed steel sleeve grouting lap joint according to claim 9, characterized in that: The conical anchor (11) comprises an anchor ring (111) and an anchor plug (112).

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