Prestressed steel strand tensioning auxiliary device
By designing a prestressed steel strand tension auxiliary device including anchor plate, clip, connecting seat and jack, the prestress loss caused by steel strand retraction during pretension construction is solved, and effective control of the backlash is achieved The effect of shrinking and reducing prestress loss.
Patent Information
- Application Number
- CN202421302749.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-06-07
- Publication Date
- 2025-02-25
- Estimated Expiration
- 2034-06-07
AI Technical Summary
In the construction of the pre-tension method, the retraction of the steel strand will lead to prestress loss, especially in the construction of small and medium-sized components, the length of the steel strand is short and the amount of retraction is large, resulting in serious prestress loss.
A prestressed steel strand tension auxiliary device is designed, including anchor plate, clamp, connecting seat and jack. Pressurized by jack, the clamp of the conical surface clamps clamp the steel strand to fix its position and reduce shrinkage. quantity.
The retraction of the steel strand is effectively controlled, prestress loss is reduced, construction efficiency is improved, and errors caused by prestress loss during construction are reduced.
Smart Images
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Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of prestressed concrete, in particular to a prestressed steel strand tensioning auxiliary device. Background Art
[0002] The construction process of prestressed concrete includes pre-tensioning and post-tensioning. Among them, the pre-tensioning construction process can ensure the effective bonding force between the prestressed steel strands and concrete. It is simple to construct, has good economic benefits, stable quality, and is suitable for the industrial production of small and medium-sized components. The journal "Transportation World" Issue 8, 2023 proposed an overall tensioning method for tensioning the steel strands of multi-body beams in series at one time. The key technologies of tensioning pedestals, tensioning, and tensioning the steel strands of multi-body beams in series were studied. The steel strands of multiple beams are connected through steel strand connectors and wire rod connectors. During the tensioning process of the steel strands, the steel strands of the series beams can be tensioned at one time, overcoming the time-consuming and labor-intensive shortcomings of the segmented tensioning method, saving labor time for tensioning steel strands, and effectively improving construction efficiency.
[0003] "Technical Specifications for Highway Bridge and Culvert Construction" JTJ041-2000 stipulates: The difference between the actual elongation value and the theoretical elongation value of the prestressed tendons shall meet the design requirements. When there is no design requirement, the difference between the actual elongation value and the theoretical elongation value shall be controlled within ±6%. The above journals have achieved one-time tensioning of the steel strands of multiple beams in series, which can be well applied to environments with limited construction conditions and shorten the construction period. However, for small and medium-sized components, the length of the steel strands in each section of the beam is relatively short. In actual engineering construction, the shrinkage of the steel strands during the tensioning process will cause the loss of prestress applied to each section of the beam. The greater the shrinkage of the steel strands, the greater the loss of prestress. Therefore, in the process of one-time tensioning of the steel strands of the series beams in the pre-tensioning construction, how to reduce the shrinkage of each section of the steel strands, thereby reducing the prestress loss of the beams, is a difficult problem that needs to be solved urgently.
[0004] Appendix E of the current national standard "Concrete Structure Engineering Construction Code" GB50666 stipulates the "Calculation and Measurement Method of Prestressed Tendon Tensioning Elongation Value". The relative allowable error between the actual prestress value established by the prestressed steel strands by the pre-tensioning method and the verification value specified in the engineering design is ±5%. One of the keys to prestressed concrete construction is to control prestress loss. Although the above-mentioned journals can be well applied to environments with limited construction conditions and shorten construction periods, in actual engineering construction, the shrinkage of the steel strands during the tensioning process will cause the loss of prestress applied to each section of the beam. The greater the shrinkage of the steel strands, the greater the prestress loss. Therefore, in the process of one-time tensioning of the steel strands of the series beams in the pre-tensioning construction, how to reduce the shrinkage of the steel strands and thus reduce the prestress loss of the beams is a problem that needs to be solved urgently. Summary of the invention
[0005] In order to solve the problems pointed out in the background technology, the utility model proposes a prestressed steel strand tensioning auxiliary device which has a simple and reliable structure, is easy to use and can effectively reduce prestress loss.
[0006] In order to achieve the above purpose, the technical solution of the utility model is:
[0007] A prestressed steel strand tensioning auxiliary device comprises a steel strand body and an anchor plate arranged at the end surface of a beam body, wherein a clip 1 is arranged inside the anchor plate, a connecting seat is movably sleeved outside the steel strand body, and a jack is arranged between the anchor plate and the connecting seat;
[0008] The connecting seat comprises an upper seat body and a lower seat body which cover each other, the upper seat body is arranged on the cylinder body of the jack through a bracket, a first arc groove is opened in the middle of one side of the upper seat body close to the lower seat body, and a second arc groove is opened in the middle of one side of the lower seat body close to the upper seat body, and the first arc groove and the second arc groove both comprise a coaxially arranged equal diameter section and a reduced diameter section;
[0009] The upper seat body and the lower seat body are covered with each other by fasteners, the equal-diameter sections of the first arc-shaped groove and the second arc-shaped groove are covered with each other to form a circular hole, the steel strand body passes through the circular hole, the first arc-shaped groove and the reduced-diameter sections of the second arc-shaped groove are covered with each other to form a tapered hole, and a second clip is arranged in the tapered hole;
[0010] A limit plate is arranged on one end of the piston rod of the jack close to the anchor plate, and a U-shaped groove for the steel strand body to pass through is opened on the limit plate, and the limit plate is pressed against the end face of the large end of the clamping piece 1.
[0011] Preferably, the limit plate and the piston rod of the jack are connected by a connecting piece, a coaxial mounting portion is integrally provided on the end face of the piston rod away from the cylinder body, a through hole is opened at the end of the limit plate away from the steel strand body, and the mounting portion is penetrated in the through hole;
[0012] A coaxial threaded hole is formed on the end surface of the mounting portion away from the cylinder body; the connecting piece comprises a large diameter section and a small diameter section threadedly matched with the threaded hole, and the diameter of the large diameter section is larger than the inner diameter of the through hole.
[0013] Preferably, two grooves are provided on the circumferential outer wall of the mounting portion, and the two grooves are symmetrically arranged along the axis of the mounting portion; two bosses are provided on the inner wall of the through hole, and the two bosses are symmetrically arranged along the axis of the through hole, and the bosses cooperate with the grooves.
[0014] Preferably, the small end of the variable diameter section is connected to the constant diameter section, and the diameter of the variable diameter section gradually increases from the end connected to the constant diameter section toward a direction away from the constant diameter section.
[0015] Preferably, the large ends of the second clip and the first clip are oriented in the same direction.
[0016] Preferably, clamping blocks are protrudingly provided on both sides of the notch of the first arc-shaped groove, and the clamping block is located in the middle of the upper seat body, and clamping grooves matching the clamping blocks are provided on both sides of the notch of the second arc-shaped groove.
[0017] Preferably, the upper seat and the lower seat are respectively provided with flanges, and through grooves for installing fasteners are provided on the flanges of the upper seat and the lower seat; the fasteners include a stopper and an L-shaped plate, and a notch is provided on the side wall of the stopper.
[0018] Preferably, one end of the stopper and the transverse portion of the L-shaped plate are respectively provided with circular holes, and bolts are passed through the circular holes.
[0019] The beneficial effects of the utility model are:
[0020] The utility model applies pressure through a jack, so that a first clamping piece with a conical surface is clamped in the conical hole of the anchor plate, and at the same time, a second clamping piece with a conical surface is clamped in the conical hole formed by the lower seat body and the upper seat body covering each other. At this time, the first clamping piece has locked and fixed the steel strand, and the retraction of the steel strand is effectively controlled, thereby reducing the prestress loss.
[0021] The utility model realizes the reduction of prestress loss by processing a boss on the piston rod of the jack and adding a connecting seat on the cylinder body, and there is no need to modify the tensioning equipment and the clamping piece in the prestressing method construction. The improvement method is simple, low in cost and strong in practicability, and a simple structure is used to reduce the prestress loss, thereby reducing the error caused by the prestress loss in the prestressed concrete construction process. BRIEF DESCRIPTION OF THE DRAWINGS
[0022] Figure 1 This is a schematic diagram of a prestressed steel strand tensioning auxiliary device of the utility model. Figure 1 .
[0023] Figure 2 This is a schematic diagram of a prestressed steel strand tensioning auxiliary device of the utility model. Figure 2 .
[0024] Figure 3 The utility model is a schematic diagram of an upper seat body in a prestressed steel strand tensioning auxiliary device.
[0025] Figure 4 The utility model is a schematic diagram of a lower seat body in a prestressed steel strand tensioning auxiliary device.
[0026] Figure 5 The utility model is a cross-sectional view of a connecting seat formed by an upper seat body and a lower seat body covering each other in a prestressed steel strand tensioning auxiliary device.
[0027] Figure 6 The utility model is a schematic diagram of the connection between a fastener and a connecting seat in a prestressed steel strand tensioning auxiliary device.
[0028] Figure 7 The utility model is a schematic diagram of the explosion state of a fastener in a prestressed steel strand tensioning auxiliary device.
[0029] Figure 8 The utility model is a schematic diagram of the connection between a limit plate and a piston rod of a jack in a prestressed steel strand tensioning auxiliary device.
[0030] Fig. 9 The utility model is a schematic diagram of the application state of a prestressed steel strand tensioning auxiliary device. DETAILED DESCRIPTION
[0031] The utility model is further described below in conjunction with the accompanying drawings and specific embodiments:
[0032] like Figures 1 to 9 As shown, a prestressed steel strand tensioning auxiliary device includes a steel strand body 1 and an anchor plate 2 arranged at the end surface of the beam body, a clip 3 is arranged inside the anchor plate 2, and it is characterized in that the outer movable sleeve of the steel strand body 1 is connected with a connecting seat, and a jack 4 is arranged between the anchor plate 2 and the connecting seat.
[0033] Specifically, the connecting seat includes an upper seat body 5 and a lower seat body 6 that cover each other. The upper seat body 5 is set on the cylinder body of the jack 4 through a bracket 7. A first arc groove 8 is opened in the middle of one side of the upper seat body 5 close to the lower seat body 6, and a second arc groove 9 is opened in the middle of one side of the lower seat body 6 close to the upper seat body 5. The first arc groove 8 and the second arc groove 9 both include a coaxially arranged equal diameter section 801 and a reducing diameter section 802.
[0034] The upper seat body 5 and the lower seat body 6 are covered with each other by a fastener 10, and the equal-diameter sections 801 of the first arc groove 8 and the second arc groove 9 are covered with each other to form a circular hole, and the steel strand body 1 passes through the circular hole, and the reducing-diameter sections 802 of the first arc groove 8 and the second arc groove 9 are covered with each other to form a tapered hole, in which a clip 2 11 is arranged.
[0035] A limit plate 12 is provided on one end of the piston rod of the jack 4 close to the anchor plate 2, and a U-shaped groove 14 for the steel strand body 1 to pass through is opened on the limit plate 12, and the limit plate 12 presses on the end surface of the large end of the clamp 3.
[0036] Please refer again Figure 8The limit plate 12 and the piston rod of the jack 4 are connected by a connecting piece 13, and a coaxial mounting portion 15 is integrally provided on the end face of the piston rod away from the cylinder body. A through hole 16 is provided on the end of the limit plate 12 away from the steel strand body 1, and the mounting portion 15 is penetrated in the through hole 16; a coaxial threaded hole 17 is provided on the end face of the mounting portion 15 away from the cylinder body; the connecting piece 13 includes a large diameter section and a small diameter section threadedly matched with the threaded hole 17, and the diameter of the large diameter section is larger than the inner diameter of the through hole 16.
[0037] In this embodiment, two grooves 18 are provided on the circumferential outer wall of the mounting portion 15, and the two grooves 18 are symmetrically arranged along the axis of the mounting portion 15; two bosses 19 are provided on the inner wall of the through hole 16, and the two bosses 19 are symmetrically arranged along the axis of the through hole 16. The bosses 19 cooperate with the grooves 18 to position the limit plate 12, thereby ensuring that the steel wire rope body 1 passes through the U-shaped groove 14 smoothly.
[0038] In this embodiment, the small end of the variable diameter section 802 is connected to the equal diameter section 801, and the diameter of the variable diameter section 802 gradually increases from the end connected to the equal diameter section 801 toward the direction away from the equal diameter section 801; in addition, the large ends of the clip 2 11 and the clip 1 3 are oriented in the same direction, thereby ensuring the force direction of the clip 1 3 and the clip 2 11.
[0039] Please refer again Figure 3 and Figure 4 The first arc-shaped groove 8 has blocks 20 protruding from both sides of its opening. The blocks 20 are located in the middle of the upper seat 5 . The second arc-shaped groove 9 has slots 21 matching the blocks 20 protruding from both sides of its opening.
[0040] Furthermore, the upper seat body 5 and the lower seat body 6 are respectively provided with flanges, and the flanges of the upper seat body 5 and the lower seat body 6 are provided with through slots 22 for installing the fastener 10; please refer to Figure 6 and Figure 7 The fastener 10 includes a stopper 23 and an L-shaped plate 24, a side wall of the stopper 23 is provided with a notch 25; and one end of the stopper 23 and a transverse portion of the L-shaped plate 24 are respectively provided with circular holes, and bolts 26 are passed through the circular holes.
[0041] The usage of this product is as follows:
[0042] When installing this unit, please refer to Figure 2, first connect the jack 4 to the limit plate 12, and then install the lower seat body 6 and the second clip 11 in sequence. During installation, the steel strand body 1 is required to align the U-shaped groove on the limit plate 12. After the installation is completed, the steel strand body 1 passes through the clip 1 3, the U-shaped groove 14, the circular hole formed by the upper seat body 5 and the lower seat body 6, and the second clip 11 in sequence. The state is as follows Figure 1 shown.
[0043] The utility model is applied in the construction process of tensioning the steel strands of the series beam body at one time, and the steel strands at the tensioning end are tensioned by the pre-tensioning method. Please refer to Figure 6 The device is installed at both ends of each section of the beam. When prestressing is performed, when the prestressing reaches the design stress, the jack 4 in the device is started to apply pressure. The clamp 1 3 with a conical surface is clamped in the conical hole of the anchor plate 2. At the same time, the clamp 2 11 with a conical surface is clamped in the conical hole formed by the upper seat 5 and the lower seat 6 covering each other. At this time, the clamp 1 3 has locked and fixed the steel strand body 1. Therefore, when the load of the tensioning equipment is released, the retraction of the heavy steel strand of each section of the beam is effectively controlled under the pressure of the jack 4, thereby reducing the prestress loss.
[0044] The embodiments described above are only preferred embodiments of the present invention and are not intended to limit the scope of implementation of the present invention. Therefore, any equivalent changes or modifications made based on the structures, features and principles described in the patent scope of the present invention should be included in the patent application scope of the present invention.
Claims
1. A prestressed steel strand tensioning auxiliary device, comprising a steel strand body (1) and an anchor plate (2) arranged at the end surface of a beam body, wherein a clip 1 (3) is arranged in the anchor plate (2), characterized in that: The outer movable sleeve of the steel strand body (1) is provided with a connecting seat, and a jack (4) is provided between the anchor plate (2) and the connecting seat; The connecting seat comprises an upper seat body (5) and a lower seat body (6) which cover each other, the upper seat body (5) being arranged on the cylinder body of the jack (4) via a bracket (7), a first arc-shaped groove (8) being provided in the middle of a side of the upper seat body (5) close to the lower seat body (6), and a second arc-shaped groove (9) being provided in the middle of a side of the lower seat body (6) close to the upper seat body (5), the first arc-shaped groove (8) and the second arc-shaped groove (9) both comprising a coaxially arranged equal-diameter section (801) and a reduced-diameter section (802); The upper seat body (5) and the lower seat body (6) are overlapped with each other via a fastener (10); the equal-diameter sections (801) of the first arc-shaped groove (8) and the second arc-shaped groove (9) are overlapped with each other to form a circular hole; the steel strand body (1) passes through the circular hole; the reduced-diameter sections (802) of the first arc-shaped groove (8) and the second arc-shaped groove (9) are overlapped with each other to form a tapered hole; a second clip (11) is arranged in the tapered hole; A limit plate (12) is provided on one end of the piston rod of the jack (4) close to the anchor plate (2), and a U-shaped groove (14) is provided on the limit plate (12) for the steel strand body (1) to pass through, and the limit plate (12) is pressed against the end surface of the large end of the clamping piece (3).
2. A prestressed steel strand tensioning auxiliary device according to claim 1, characterized in that: The limit plate (12) and the piston rod of the jack (4) are connected via a connecting piece (13); a coaxial mounting portion (15) is integrally provided on an end surface of the piston rod away from the cylinder body; a through hole (16) is provided on an end of the limit plate (12) away from the steel strand body (1); and the mounting portion (15) is inserted into the through hole (16); A coaxial threaded hole (17) is formed on an end surface of the mounting portion (15) away from the cylinder body; the connecting piece (13) comprises a large diameter section and a small diameter section threadably matched with the threaded hole (17); the diameter of the large diameter section is larger than the inner diameter of the through hole (16).
3. A prestressed steel strand tensioning auxiliary device according to claim 2, characterized in that: Two grooves (18) are provided on the circumferential outer wall of the mounting portion (15), and the two grooves (18) are symmetrically arranged along the axis of the mounting portion (15); two bosses (19) are provided on the inner wall of the through hole (16), and the two bosses (19) are symmetrically arranged along the axis of the through hole (16), and the bosses (19) cooperate with the grooves (18).
4. The prestressed steel strand tensioning auxiliary device according to claim 1, characterized in that: The small end of the reduced diameter section (802) is connected to the equal diameter section (801), and the diameter of the reduced diameter section (802) gradually increases from the end connected to the equal diameter section (801) in a direction away from the equal diameter section (801).
5. The prestressed steel strand tensioning auxiliary device according to claim 1, characterized in that: The large ends of the second clip (11) and the first clip (3) are oriented in the same direction.
6. A prestressed steel strand tensioning auxiliary device according to claim 1, characterized in that: Blocks (20) are protrudingly provided on both sides of the notch of the first arc-shaped groove (8), and the block (20) is located in the middle of the upper seat body (5). Slots (21) matching the block (20) are provided on both sides of the notch of the second arc-shaped groove (9).
7. The prestressed steel strand tensioning auxiliary device according to claim 1, characterized in that: The upper seat body (5) and the lower seat body (6) are each provided with a flange, and a through groove (22) for installing a fastener (10) is provided on the flange of the upper seat body (5) and the lower seat body (6); the fastener (10) comprises a stopper (23) and an L-shaped plate (24), and a notch (25) is provided on a side wall of the stopper (23).
8. The prestressed steel strand tensioning auxiliary device according to claim 7, characterized in that: One end of the stopper (23) and the transverse portion of the L-shaped plate (24) are respectively provided with circular holes, and bolts (26) are passed through the circular holes.