Device for releasing prestressed concrete

Abstract

The device comprises a bottom plate and a top plate located over the bottom plate, a first circular through hole is formed in the middle of the bottom plate, a second circular through hole is formed in the middle of the top plate, and the bottom plate and the top plate are connected through a plurality of bearing columns surrounding the first circular through hole at intervals; the bottom plate is matched with an anchor bearing plate on prestressed concrete to be released, the first circular through hole is matched with a working anchorage device on the prestressed concrete to be released, the top plate is matched with an oil cylinder of the jack, and all steel strands on the working anchorage device can pass through the second circular through hole; the interval between every two adjacent bearing columns is not larger than the size of a working clamping piece used for fixing a steel strand. When the prestressed concrete beam body needs to be released, a single steel strand does not need to be sequentially and circularly released, and potential safety hazards existing in non-released steel strands and damage to prestressed tendons caused by multiple times of releasing do not need to be worried about.

Description

Technical Field

[0001] The utility model relates to the technical field of road and bridge construction equipment, in particular to a device for releasing prestressed concrete. Background Art

[0002] Prestressed concrete beams are the most common form of crossing obstacles in road and bridge construction. In the construction of prestressing, post-tensioning method is often used for construction. When pouring concrete, vibrators are generally inserted for vibration. The vibrators are manually operated, and the concrete vibration requirements are high. The vibration quality is difficult to control. The steel bars behind the anchor pad are dense, and the vibrator is not easy to insert. It is difficult to make the concrete vibrated dense, and holes are easy to appear and difficult to see with the naked eye. When the concrete strength reaches the design strength and the prestressing begins, the holes behind the anchor pad and the loose vibration make it difficult to support the stress applied by the jack to the steel strands of the beam body, resulting in concrete cracking or the working anchor moving backward and sinking into the concrete, or the steel strands are stored in an unqualified manner and rusted, affecting the mechanical properties of the steel strands, and then wire breakage and root breakage occur. At this time, we can only release the steel strands of the beam body, repair the damaged concrete or replace the steel strands, and tension them again.

[0003] At present, when encountering such a situation, a single steel strand is often used for cyclic tensioning. When a single steel strand is used for cyclic tensioning, when one of the strands is tensioned, the steel strands of other strands are exposed outside, and the safety of the construction workers cannot be well guaranteed. Cyclic tensioning for multiple times in sequence causes excessive damage to the reserved exposed steel strands. When prestressing is applied in the later stage, the probability of broken wires and roots increases, and safety hazards increase accordingly, which leads to long construction period, high cost and high risk. Summary of the invention

[0004] In view of the problems existing in the prior art, the utility model provides a device for prestressed concrete tensioning. When the prestressed concrete beam needs to be tensioned, it is no longer necessary to tension a single steel strand in a cycle, nor is there any need to worry about the safety hazards of untensioned steel strands and the damage to the prestressed tendons caused by multiple tensioning. Construction efficiency can be improved, construction costs can be reduced, construction period can be shortened, and risks can be avoided.

[0005] In order to solve the above technical problems, the utility model is implemented through the following technical solutions:

[0006] A device for tensioning prestressed concrete, comprising a bottom plate and a top plate located directly above the bottom plate, wherein a first circular through hole is provided in the middle of the bottom plate, and a second circular through hole is provided in the middle of the top plate, and the bottom plate and the top plate are connected by a plurality of load-bearing columns spaced around the first circular through hole; the bottom plate matches an anchor plate on the prestressed concrete to be tensioned, the first circular through hole matches a working anchor on the prestressed concrete to be tensioned, the top plate matches an oil cylinder of a jack, and the second circular through hole allows all steel strands on the working anchor to pass through; the interval between two adjacent load-bearing columns is not greater than the size of a working clip for fixing the steel strands.

[0007] Furthermore, it also includes a working clip remover, which includes a straight rod and a hook connected to one end of the straight rod, the curvature of the hook matches the groove of the working clip, and the hook can extend into the gap between two adjacent load-bearing columns.

[0008] Furthermore, the inner side surface of each load-bearing column is an arc surface, and the arc surface is tangent to and concentric with the first circular through hole.

[0009] Furthermore, the height of the load-bearing column is greater than the sum of the thickness of the working anchor and the length of the working clip.

[0010] Furthermore, the axes of the first circular through hole and the second circular through hole coincide with each other.

[0011] Furthermore, a plurality of load-bearing columns are evenly distributed around the first circular through hole.

[0012] Furthermore, the upper and lower ends of the load-bearing column are fixed to the corresponding top plate and bottom plate by welding.

[0013] Compared with the prior art, the utility model has at least the following beneficial effects:

[0014] The utility model provides a device for prestressed concrete tensioning. When tensioning, a tensioner is used to place a bottom plate on an anchor pad where a steel strand bundle is to be tensioned, so that the bottom plate matches the anchor pad, and a working anchor is placed at a first circular through hole on the bottom plate. The working anchor is in close contact with the first circular through hole and is at the same center of a circle. The load-bearing column bears the pressure applied by the jack during tensioning, and the distance between two adjacent load-bearing columns is smaller than the geometric dimensions of the working clip, ensuring the safety of personnel and equipment during tensioning. The top plate matches the oil cylinder of the jack. When stress is applied, the top plate transfers the stress to the bottom plate through the load-bearing column, and then transfers it to the anchor pad to disperse the stress, ensuring the safety of personnel and components during tensioning. The second circular through hole on the top plate allows the steel strand to pass smoothly and there is no contact between the steel strand and the tensioner, ensuring safety during tensioning. When the tensioning device of the utility model is used for prestressed concrete that needs to be tensioned, the size of the tensioner can be adjusted according to the size of the working anchor and the number of steel strand bundles to achieve the overall tensioning effect, and all working clips are in the load-bearing column, and no splashing will occur during tensioning, thereby avoiding injury to personnel and mechanical equipment. It is no longer necessary to tension a single steel strand in a cycle in sequence, and the overall number of cycles during tensioning is small, which greatly reduces the probability of wire breakage and root breakage when prestressing is applied in the later stage, thereby improving construction efficiency, reducing construction costs and reducing construction risks.

[0015] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, preferred embodiments are given below and described in detail with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solutions in the specific implementation modes of the present invention, the drawings required for use in the description of the specific implementation modes will be briefly introduced below. Obviously, the drawings described below are some implementation modes of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0017] Figure 1 This is a schematic diagram of the structure of a device for prestressed concrete tensioning according to the utility model;

[0018] Figure 2 This is a schematic diagram of the structure of a working clip remover in a device for prestressed concrete tensioning according to the utility model;

[0019] Figure 3 It is a schematic diagram of the planing surface of a device for prestressed concrete tensioning during tensioning of the utility model;

[0020] Figure 4 The utility model is a partial schematic diagram of a device for prestressed concrete tensioning.

[0021] In the figure: 1-bottom plate; 100-first circular through hole; 2-top plate; 200-second circular through hole; 3-load-bearing column; 4-working anchor; 5-jack; 500-oil cylinder; 6-working clip remover; 600-straight rod; 601-bend hook; 7-tool anchor. DETAILED DESCRIPTION

[0022] In order to make the purpose, technical solution and advantages of the embodiments of the utility model clearer, the technical solution of the utility model will be clearly and completely described below in conjunction with the accompanying drawings. Obviously, the described embodiments are part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0023] Combination Figures 1 to 4 As shown, an embodiment of the utility model provides a device for prestressed concrete tensioning, including a bottom plate 1, a top plate 2, a plurality of load-bearing columns 3 and a working clip remover 6. The bottom plate 1 and the top plate 2 located directly above the bottom plate 1, the bottom plate 1 is the basic part of the device, and its shape and size are designed according to actual needs. The size and shape of the bottom plate 1 need to ensure that it matches the anchor plate on the prestressed concrete to be tensioned, so that it can be stably placed on the anchor plate. A first circular through hole 100 is opened in the middle position of the bottom plate 1. The size of the first circular through hole 100 matches the working anchor 4 on the prestressed concrete to be tensioned, ensuring that the working anchor 4 can smoothly cooperate with the first circular through hole 100.

[0024] The top plate 2 is located directly above the bottom plate 1 , and a second circular through hole 200 is opened in the middle of the top plate 2 . The size of the second circular through hole 200 needs to be sufficient to allow all steel strands on the working anchor 4 to pass through without interference. The top plate 2 matches the cylinder 500 of the jack 5 .

[0025] The bottom plate 1 and the top plate 2 are connected by a plurality of load-bearing columns 3 that are spaced around the first circular through hole 100, and the spacing between two adjacent load-bearing columns 3 is not larger than the size of the working clips used to fix the steel strands. In other words, the load-bearing columns 3 are important components that connect the bottom plate 1 and the top plate 2. They surround the first circular through hole 100 and are evenly distributed at certain intervals. The spacing between two adjacent load-bearing columns 3 is not larger than the size of the working clips used to fix the steel strands to prevent the working clips from popping out and injuring people. Exemplarily, the upper and lower ends of the load-bearing columns 3 are fixed to the corresponding top plate 2 and bottom plate 1 by welding to ensure the stability and safety of the device.

[0026] Preferably, the inner side surface of each load-bearing column 3 is an arc surface, which is tangent to and concentric with the first circular through hole 100 to ensure a smooth transition between the load-bearing column and the through hole, and to avoid interference between the steel strand and the load-bearing column 3, thereby preventing damage to the steel strand. In this embodiment, the height of the load-bearing column 3 is greater than the sum of the thickness of the working anchor 4 and the length of the working clip.

[0027] like Figure 2 As shown, the working clip remover 6 includes a straight rod 600 and a hook 601 connected to one end of the straight rod 600. The curvature of the hook 601 matches the groove of the working clip. The hook 601 can extend into the interval between two adjacent load-bearing columns 3 to facilitate the movement of the working clip during the release process. It should be noted that the working clip remover 6 is an independent tool. Exemplarily, the straight rod 600 and the hook 601 are integrally formed or connected by welding.

[0028] In one embodiment, the outer diameter of the bottom plate 1 is the same as the outer diameter of the anchor plate, the inner diameter of the first circular through hole 100 on the bottom plate 1 needs to be close to the working anchor 4, the load-bearing columns 3 are evenly arranged between the upper and lower steel plates, and are connected to the upper and lower steel plates by welding. The inner side of the load-bearing columns 3 is arc-shaped and the outer side is square. The arc is the same as the circular through holes on the upper and lower steel plates, and the load-bearing columns 3 must meet the pressure applied by the jack during tensioning. The outer diameter of the top plate 2 needs to match the cylinder 500 of the jack 5, and the inner diameter of the second circular through hole 200 on the top plate 2 needs to allow the steel strand on the working anchor 4 to pass smoothly, and the steel strand has no contact with the tensioner to ensure safety during tensioning.

[0029] Combination Figure 3 As shown, the device for prestressed concrete tensioning provided by this embodiment is used to first tension the beam body, and then re-tension it after solving the existing problems. The tensioning method is as follows: first clean the cement slurry on the anchor plate and then install the tensioning device, then install the tensioning jack 5, then install the tool anchor 7 and the tool clip, and finally the jack 5 applies pressure to complete the tensioning. The details are as follows:

[0030] First, clean the residual cement slurry on the anchor plate of the beam to be tensioned, so that the bottom plate 1 is completely fitted with the anchor plate, the first circular through hole 100 is completely fitted with the working anchor 4, the outer diameter of the top plate 2 needs to match the cylinder 500 of the jack, and the second circular through hole 200 needs to allow the steel strand to pass smoothly without any contact between the steel strand and the tensioner 1 to ensure safety during tensioning. The tensioner is installed in place, and then the jack 5 and the tool anchor 7 are installed to ensure that the tensioner, jack 5, and tool anchor 7 are on the same axis.

[0031] Secondly, before the jack 5 starts to apply stress, the jack's oil cylinder 500 is first stroked to more than 5cm and stopped working, and then the tool anchor 7 and tool clip are installed to prevent the jack 5 from clamping after the pressure is relieved. Before the release begins, calculate how many release cycles are needed, and each release stroke must not be greater than the length of a working clip to prevent the working clip from detaching and being difficult to install, causing sluggishness and ensuring the safety of personnel and mechanical equipment.

[0032] The jack 5 applies pressure again to make the working clip slightly detach from the working anchor 4 (as long as the working clip can move), then the jack 5 stops applying pressure and enters the pressure stabilization stage, and then the working clip remover 6 is used to move the working clip to detach the working clip from the working anchor 4 by the length of one working clip, (the outward stroke of the jack's oil cylinder 5 must be greater than the length of one working clip and greater than 5cm), and the working clip is moved from the middle to both sides in sequence. After confirmation, the jack unloads the pressure and allows the working clip to be embedded in the working anchor 4 to complete the anchoring. Check that the leakage length of the jack's oil cylinder 500 must be greater than 5cm. If it is not satisfied, the jack is operated at a no-load position greater than 5cm, and then the tool anchor 7 and the tool clip are installed, and the process is repeated in sequence to complete the release work.

[0033] Finally, remove the jack and tensioner and check the damage of the steel strands. If any of the steel strands are too damaged to meet the stress of the later tensioning, they need to be replaced in time.

[0034] It should be noted that, in the present embodiment, the outer diameter of the bottom plate is determined according to the diameter of the anchor plate; the inner diameter of the first circular through hole is determined according to the diameter of the working anchor; the height of the load-bearing column is determined according to the thickness of the working anchor and the length of the working clip; the outer diameter of the top plate is determined according to the cylinder diameter of the jack; the inner diameter of the second circular through hole is determined according to the spacing between the steel strand bundle holes; the diameter and shape of the hook at the end of the working clip remover are determined according to the groove at the tail of the working clip, and the length of the clip remover is determined according to the actual working space on site.

[0035] Exemplarily, the bottom plate 1 and the top plate 2 can be cut and formed using ordinary steel plates Q345b, and the load-bearing columns 3 must be cut and formed using high-quality steel Q370r.

[0036] The load-bearing columns 3 are evenly distributed between the bottom plate 1 and the top plate 2. The column spacing of the load-bearing columns 3 must allow the working clip remover 6 to enter and exit freely, and the column spacing of the load-bearing columns 3 must be smaller than the geometric dimensions of the working clip to prevent the working clip from splashing when being released and injuring personnel and mechanical equipment.

[0037] Exemplarily, the height of the load-bearing column 3 is equal to the thickness of a working anchor plus the length of a working clip plus 2 cm. The tensioner can be purchased on site or made by yourself.

[0038] When releasing the prestressing, the lower steel plate is in close contact with the anchor plate, the upper steel plate is in close contact with the jack, the inner side of the load-bearing column is in close contact with the working anchor, and the distance between two adjacent load-bearing columns is smaller than the geometric dimensions of the clip, ensuring the safety of personnel and equipment during the release. This device directly solves the dilemma of no equipment available when releasing multiple prestressing beams at the same time, and also solves the safety and quality risks caused by the release of a single prestressing equipment. This device has a simple structure, convenient processing, simple operation, flexible use, low cost, quick installation, and strong on-site applicability.

[0039] In one embodiment, when cracks or depressions occur at the end of the beam body or the strands of steel wire are broken or rooted, and the design requirements are no longer met, and tensioning must be performed, the tensioning device of this embodiment can be used for tensioning. First, the degree of damage to the end of the beam body is evaluated or the strands of steel wire with broken wires or roots are evaluated to understand the degree of damage and the degree of safety hazards during tensioning. It should be noted that if cracks or depressions occur in the concrete beam body, the beam end must be reinforced before tensioning can be performed.

[0040] When the stress of the beam body is stable or the working anchor 4 is no longer displaced, the measurement can be arranged to process and install the tensioner and other equipment to enter the site for tensioning. After the tensioning work is completed, the reserved working length of the steel strand and the concrete at the beam end are evaluated to check whether the reserved working length of the steel strand and the concrete at the beam end meet the requirements of re-applying prestress without wire breakage, root breakage, depression, cracks, etc. If wire breakage, root breakage, etc. exist before tensioning, the replacement of the steel strand can be completed after tensioning. If cracks, depressions, etc. exist in the concrete at the beam end before tensioning, the reinforcement facilities are removed after tensioning is completed to complete the remedial work of the concrete at the beam end.

[0041] Before laying the steel strands, the mechanical equipment must be inspected and all construction personnel participating in the laying must be briefed on safety techniques. Non-construction personnel are not allowed to enter the area affected by the laying. Laying of steel strands is prohibited at night and a safety warning area and full-time safety inspectors must be set up.

[0042] The utility model is suitable for prestressed concrete beams when prestress is applied, the beam ends are dented, cracked or the steel strands are broken, and the design requirements can no longer be met and tensioning must be performed. The tensioner is easy to process and has a low manufacturing cost. It is easy to operate, quick to install, flexible to use, reduces the cost of processing prestressed concrete beams, shortens the construction period, and directly solves the dilemma of no equipment available when multiple prestressing beams are tensioned at the same time. It also solves the safety and quality risks caused by the tensioning of a single prestressing device, and is suitable for on-site application.

[0043] In the description of the present invention, it is necessary to understand that the terms "upper", "lower", "bottom", "inside", "outside", etc., indicating the orientation or position relationship are based on the orientation or position relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0044] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of the present utility model, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0045] In the present invention, unless otherwise clearly defined and limited, the terms "connected", "connection" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection, an electrical connection, or communication with each other; it can be a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0046] In the present utility model, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being "above", "above" or "above" a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being "below", "below" or "below" a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0047] In the present utility model, the terms "one embodiment", "some embodiments", "examples", "specific examples", or "some examples" etc. mean that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present utility model. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the described specific features, structures, materials or characteristics may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0048] Finally, it should be noted that the above-described embodiments are only specific implementation methods of the utility model, which are used to illustrate the technical solution of the utility model, rather than to limit it. The protection scope of the utility model is not limited thereto. Although the utility model is described in detail with reference to the above-mentioned embodiments, ordinary technicians in this field should understand that any technician familiar with the technical field can still modify the technical solution recorded in the above-mentioned embodiments within the technical scope disclosed by the utility model, or can easily think of changes, or make equivalent replacements for some of the technical features therein; and these modifications, changes or replacements do not make the essence of the corresponding technical solution deviate from the spirit and scope of the technical solution of the embodiment of the utility model, and should be included in the protection scope of the utility model. Therefore, the protection scope of the utility model shall be based on the protection scope of the claims.

Claims

1. A device for prestressed concrete tensioning, characterized in that: The invention comprises a bottom plate (1) and a top plate (2) located directly above the bottom plate (1); a first circular through hole (100) is opened in the middle of the bottom plate (1); a second circular through hole (200) is opened in the middle of the top plate (2); the bottom plate (1) and the top plate (2) are connected by a plurality of load-bearing columns (3) spaced around the first circular through hole (100); the bottom plate (1) matches the anchor plate on the prestressed concrete to be tensioned; the first circular through hole (100) matches the working anchor (4) on the prestressed concrete to be tensioned; the top plate (2) matches the oil cylinder (500) of the jack (5); the second circular through hole (200) allows all the steel strands on the working anchor (4) to pass through; the interval between two adjacent load-bearing columns (3) is not greater than the size of the working clamp used to fix the steel strands.

2. A device for prestressed concrete tensioning according to claim 1, characterized in that: It also includes a working clip remover (6), which includes a straight rod (600) and a hook (601) connected to one end of the straight rod (600), the curvature of the hook (601) matches the groove of the working clip, and the hook (601) can extend into the gap between two adjacent load-bearing columns (3).

3. A device for prestressed concrete tensioning according to claim 2, characterized in that: The straight rod (600) and the curved hook (601) are integrally formed.

4. The device for prestressed concrete tensioning according to claim 1, characterized in that: The inner side surface of each load-bearing column (3) is an arc surface, and the arc surface is tangent to and concentric with the first circular through hole (100).

5. The device for prestressed concrete tensioning according to claim 1, characterized in that: The height of the load-bearing column (3) is greater than the sum of the thickness of the working anchor (4) and the length of the working clip.

6. The device for prestressed concrete tensioning according to claim 1, characterized in that: The axes of the first circular through hole (100) and the second circular through hole (200) coincide with each other.

7. The device for prestressed concrete tensioning according to claim 1, characterized in that: A plurality of load-bearing columns (3) are evenly distributed around the first circular through hole (100).

8. The device for prestressed concrete tensioning according to claim 1, characterized in that: The upper and lower ends of the load-bearing column (3) are fixed to the corresponding top plate (2) and bottom plate (1) by welding.

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