Single-hole clip anchor capable of measuring force for prestressing and device and method for measuring force of prestressing value

Abstract

The present invention discloses a single-hole clip anchor with force measurable for prestressing and a device and method for measuring force of prestressing value. The single-hole clip anchor with force measurable can replace the currently used single-hole clip anchor for use in engineering projects. When prestressing needs to be detected, a matching prestressing detection device can be used to perform prestressing detection. The force-measurable anchor comprises a pressure plate and a force-measurable anchor when in use. When prestressing is detected, the anchor comprises a force-measurable steel strand, a connecting anchor, a reaction frame, a pressure sensor, a tensioning jack, an electronic displacement meter and a data acquisition system. The single-hole clip anchor with force measurable in the present invention is provided with threads on the outside on the basis of the existing anchor, has a simple structure, is easy to detect with a matching detection device, and saves costs. The force-measurable steel strand and the connecting anchor can be used to extend any prestressing steel strand, tension the force-measuring steel strand, and read the force value and electronic displacement count value of the pressure sensor for detection.

Description

Technical Field

[0001] The present invention relates to the field of prestress detection technology, and more specifically to a single-hole anchor for the tensioning end of an unbonded prestressed steel strand and a slow-bonded prestressed steel strand, and a connecting device and a detection method for detecting the end prestress value by using the tensioning end anchor after cutting the reinforcement. Background Art

[0002] Unbonded prestressed tendons and slow-bonded prestressed tendons are widely used in construction projects. After the construction is completed, the ends of the unbonded prestressed tendons and slow-bonded prestressed tendons are fixed to the end faces of the concrete through clip anchors and pressure plates. After the prestressed tendons are cut, the ends exposed from the anchors should be no less than 30mm and generally no more than 50mm as specified in the specifications. Many construction projects need to test the prestress of the unbonded prestressed tendons because their functions need to be changed after several years of use. Slow-bonded prestressed projects also encounter the problem of testing the prestress value before the slow-bonding agent is cured. The commonly used unbonded prestressed tendons are steel strands with a diameter of 15.2mm and a cross-sectional area of ​​140mm. 2 The prestress is generally 14 to 20 tons. It is very difficult to measure the end tension. There is no effective detection device and detection method. The existing jacks must leave at least 200mm steel strands for prestressing detection. Therefore, the existing jacks cannot directly tension the 30mm to 50mm steel strands exposed at the end of the anchor and detect the prestress value.

[0003] Therefore, how to provide a tensioning end anchor, a detection device and a method that are simple to operate and can accurately measure the prestress value is a problem that technical personnel in this field urgently need to solve. Summary of the invention

[0004] In view of this, the present invention provides a prestressed force-measurable single-hole clip anchor connection device, aiming to solve the above-mentioned technical problems.

[0005] In order to achieve the above object, the present invention adopts the following technical solution:

[0006] A single-hole clip anchor capable of measuring force for prestressing is used for tensioning and anchoring prestressed steel strands in concrete structures. The anchor comprises a pressure plate and a measurable anchor. When force measurement is required, force measurement can be conveniently performed.

[0007] The pressure bearing plate is sleeved on the prestressed steel strand and fits with the end surface of the concrete structure;

[0008] The force-measurable anchor comprises a force-measurable anchor ring and a force-measurable wedge-shaped clip; the force-measurable anchor ring is sleeved on the end of the prestressed steel strand and has an external thread on the outside; the force-measurable wedge-shaped clip is tightened between the side wall of the end of the prestressed steel strand and the force-measurable anchor ring, and the force-measurable anchor ring is pressed against the pressure plate.

[0009] Through the above technical scheme, the force-measurable single-hole clip anchor provided by the present invention can replace the currently used single-hole clip anchor in engineering projects; a thread is set on the outside on the basis of the existing anchor, and when prestress needs to be detected, a matching prestress detection device can be used to perform prestress detection, which has a simple structure and saves costs.

[0010] The present invention also provides a prestress value force measuring device connected to a prestress force-measurable single-hole clip anchor, comprising: a pressure plate, a force-measurable anchor, a steel strand for force measurement, a connecting anchor, a force-applying component and a data acquisition system;

[0011] The pressure bearing plate is sleeved on the prestressed steel strand and fits with the end surface of the concrete structure;

[0012] The force-measurable anchor comprises a force-measurable anchor ring and a force-measurable wedge-shaped clip; the force-measurable anchor ring is sleeved on the end of the prestressed steel strand and has an external thread on the outside; the force-measurable wedge-shaped clip is tightened between the side wall of the end of the prestressed steel strand and the force-measurable anchor ring, and the force-measurable anchor ring is pressed against the pressure plate;

[0013] The end of the force measuring steel strand corresponds to the end of the prestressed steel strand and is coaxially arranged to extend in the opposite direction of the concrete structure;

[0014] The connecting anchor comprises a connecting anchor ring and a connecting wedge-shaped clip; the connecting anchor ring is sleeved on the end of the force measuring steel strand, and the end has an internal thread and is threadedly connected with the force measuring anchor ring; the connecting wedge-shaped clip is pressed tightly between the side wall of the end of the force measuring steel strand and the connecting anchor ring;

[0015] The force-applying assembly is located at the end surface of the concrete structure and is connected to the extended force-measuring steel strand, and is used to apply tension to the force-measuring steel strand and detect its force value and displacement value;

[0016] The data acquisition system is used to collect the force value and displacement value detected by the force application component.

[0017] Through the above technical scheme, the present invention directly fixes a measurable force anchor with external threads on the prestressed steel strand, and by providing a force measuring steel strand, the connecting anchor is directly connected to the measurable force anchor, so that the prestressed steel strand and the force measuring steel strand are quickly connected to form a whole, and the prestress value can be quickly obtained through the cooperation of the force-applying component and the data acquisition system. It is suitable for the prestress detection of the ends of unbonded prestressed tendons and slow-bonded prestressed tendons whose ends are fixed to the end face of the concrete structure through anchors and pressure plates inside the structure. It has a simple structure, convenient connection, low cost and high measurement accuracy.

[0018] It should be noted that the inner wall of the force-measurable anchor ring has an inclined surface structure that matches the angle of the force-measurable wedge-shaped clip; the inner wall of the connecting anchor ring has an inclined surface structure that matches the angle of the connecting wedge-shaped clip, so that a clamping effect can be formed between the anchor ring and the wedge-shaped clip.

[0019] Preferably, in the above-mentioned prestress value force measuring device connected to the prestressing force-measurable single-hole clip anchor, the force-applying assembly includes a reaction frame, a pressure sensor, a tensioning jack and an electronic displacement meter; the reaction frame passes through the force-measuring steel strand and fits against the end face of the concrete structure; the pressure sensor passes through the force-measuring steel strand and presses against the reaction frame; the tensioning jack passes through the force-measuring steel strand and presses against the pressure sensor, and the tensioning jack is connected to the force-measuring steel strand; the electronic displacement meter is installed at the exposed part of the oil cylinder of the tensioning jack. Through the cooperation of the tensioning jack and the pressure sensor, the tensioning of the force-measuring steel strand and the detection of the tension value and displacement value can be stably and effectively achieved.

[0020] Preferably, in the above-mentioned prestress value force measuring device connected to the prestress force-measurable single-hole clip anchor, the data acquisition system is electrically connected to the pressure sensor and the electronic displacement meter respectively. The connection is simple and the detection is effective.

[0021] Preferably, in the above-mentioned prestress value force measuring device connected to the prestressed force-measurable single-hole clip anchor, the reaction frame includes a round steel pipe, a force diffusion steel plate, an end round steel plate and a triangular stiffening plate; the round steel pipe is coaxially sleeved on the outside of the force-measuring steel strand; the force diffusion steel plate is fixed to the end of the round steel pipe, and has a first through hole passing through the force-measuring steel strand, and fits with the end face of the concrete structure; the end round steel plate is fixed to the other end of the round steel pipe, and has a second through hole for the force-measuring steel strand to pass through; the triangular stiffening plates are multiple in number, and are fixed between the outer wall of the round steel pipe and the force diffusion steel plate. The reaction frame has a simple structure and is easy to use. It does not need to be rigidly connected to the concrete structure, can play a good supporting effect, and can evenly distribute the reaction force on the surface of the concrete structure.

[0022] Preferably, in the above-mentioned prestress value force measuring device connected to the prestressed force-measurable single-hole clip anchor, the length of the round steel pipe is 120mm-150mm, the wall thickness is 6mm-8mm, and the inner diameter is 5mm-10mm larger than the outer diameter of the connecting anchor ring; the thickness of the force diffusion steel plate is 16mm-20mm, the inner diameter of the first through hole is 5mm-10mm larger than the outer diameter of the connecting anchor ring; the outer diameter of the end round steel plate is 10mm larger than the outer diameter of the round steel pipe, and the thickness is 10mm. It can meet the size requirements of the connection.

[0023] Preferably, in the above-mentioned prestress value force measuring device connected to the prestress force-measurable single-hole clip anchor, the number of the triangular stiffening plates is 3-4, which can improve the structural strength and stability of the connection.

[0024] Preferably, in the above-mentioned prestress value force measuring device connected to the prestress force-measurable single-hole clip anchor, the length of the prestressed steel strand exposed from the end surface of the concrete structure is greater than 30 mm, which can meet the measurement requirements.

[0025] Preferably, in the above-mentioned prestress value force measuring device connected to the prestress force-measurable single-hole clip anchor, the force-measuring steel strand has the same specifications as the engineering steel strand and a length of 500mm-600mm, which can meet the subsequent tensioning length.

[0026] Preferably, in the above-mentioned prestress value force measuring device connected to the prestress force-measurable single-hole clip anchor, the threaded connection length of the connecting anchor ring and the force-measurable anchor ring is 13mm-15mm, which can meet the stability of the connection.

[0027] Preferably, in the above-mentioned prestress value force measuring device connected to the prestressing force-measurable single-hole clip anchor, the connection anchor ring and the force-measurable anchor ring have a cavity inside after being connected to prevent the steel strands from interfering with each other.

[0028] The present invention also provides a method for detecting a prestress value force measuring device connected to a prestress force-measurable single-hole clip anchor, comprising the following steps:

[0029] S1. Clamp and anchor the prestressed steel strand exposed from the concrete structure by means of a force-measurable anchor ring and a force-measurable wedge-shaped clamp, so that the force-measurable anchor ring clamps the prestressed steel strand and presses against the pressure plate;

[0030] S2. Clamp and anchor one end of the force measuring steel strand by connecting the anchor ring and the connecting wedge-shaped clamp;

[0031] S3, tighten the threaded connection between the connecting anchor ring and the force-measurable anchor ring;

[0032] S4. Coaxially sleeve the reaction frame on the outside of the force measuring steel strand and place it close to the end face of the concrete structure;

[0033] S5. Install a pressure sensor and a tensioning jack on the force measuring steel strand in sequence, and install an electronic displacement meter at the exposed position of the tensioning jack cylinder;

[0034] S6, connecting the values ​​of the pressure sensor and the electronic displacement meter to the data acquisition system;

[0035] S7, perform tensioning test, the oil cylinder of the tensioning jack begins to extend, the pressure sensor begins to generate pressure value, and the data is read and recorded;

[0036] S8. During the tension test, a tension-displacement curve is drawn. When a turning point appears in the tension-displacement curve and the slope decreases significantly, the force value at the turning point is the detected prestress value.

[0037] S9. Stop the test, unload the tensioning jack, remove the tensioning jack, electronic displacement meter, pressure sensor and reaction frame, unscrew the force measuring steel strand and connecting anchor, and complete the prestressing test of a prestressed tendon.

[0038] Through the above technical scheme, the present invention directly fixes a measurable force anchor with external threads on the prestressed steel strand, and the provided method utilizes the force-measuring steel strand and the connecting anchor to extend the prestressed steel strand, which can be directly threaded. A reaction frame, a pressure sensor, and a tensioning jack are sequentially installed on the prestressed steel strand, and an electronic displacement meter is installed to measure the extension of the oil cylinder of the tensioning jack; the force-measuring steel strand is tensioned, the force value and the electronic displacement count value of the pressure sensor are read, and the data is collected through a data acquisition system; by observing the force-displacement curve, when the force-displacement curve suddenly turns and tends to be flat, the force value is the prestress value; the present invention has a simple structure and is easy to detect. Experiments have shown that when the prestressed steel strand is exposed to the end face of the concrete structure by more than or equal to 30 mm, the prestress value can be detected.

[0039] It can be seen from the above technical solutions that, compared with the prior art, the present invention discloses a prestressed force-measurable single-hole clip anchor connection device and a detection method, which have the following beneficial effects:

[0040] 1. The force-measurable single-hole clip anchor provided by the present invention can replace the currently used single-hole clip anchor in engineering projects; a thread is provided on the outside of the existing anchor, and when prestress needs to be detected, a matching prestress detection device can be used for prestress detection, which has a simple structure and saves costs.

[0041] 2. The present invention directly fixes a measurable force anchor with external threads on the prestressed steel strand. By providing a force measuring steel strand, the connecting anchor is directly connected to the measurable force anchor, so that the prestressed steel strand and the force measuring steel strand are quickly connected to form a whole. The prestress value can be quickly obtained through the cooperation of the force-applying component and the data acquisition system. It is suitable for the end prestress detection of unbonded prestressed tendons and slow-bonded prestressed tendons whose ends are fixed to the end face of the concrete structure through anchors and pressure plates inside the structure. It has a simple structure, convenient connection, low cost and high measurement accuracy.

[0042] 3. The present invention directly fixes a force-measurable anchor with external threads on the prestressed steel strand. The provided method utilizes the force-measuring steel strand and the connecting anchor to extend the prestressed steel strand. Direct threaded connection is sufficient. A reaction frame, a pressure sensor, and a tensioning jack are sequentially installed on the prestressed steel strand, and an electronic displacement meter is installed to measure the extension of the oil cylinder of the tensioning jack. The force-measuring steel strand is tensioned, the force value and the electronic displacement count value of the pressure sensor are read, and the data is collected through a data acquisition system. By observing the force-displacement curve, when the force-displacement curve suddenly turns and tends to be flat, the force value is the prestress value. The present invention has a simple structure and is easy to detect. Experiments have shown that when the prestressed steel strand is exposed to the end face of the concrete structure by more than or equal to 30 mm, the prestress value can be detected. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying creative work.

[0044] Figure 1 The accompanying drawing is a schematic structural diagram of a prestressed force-measurable single-hole clip anchor provided by the present invention;

[0045] Figure 2 The accompanying drawing is a schematic structural diagram of a prestress value force measuring device provided by the present invention connected to a prestress force-measurable single-hole clip anchor;

[0046] Figure 3 The accompanying drawing is a schematic structural diagram of a reaction frame provided by the present invention;

[0047] Figure 4 The accompanying drawing is a schematic diagram of the structure of step S1 in the detection method provided by the present invention;

[0048] Figure 5 The accompanying drawing is a schematic diagram of the structure of step S2 in the detection method provided by the present invention;

[0049] Figure 6 The accompanying drawing is a schematic diagram of the structure of step S3 in the detection method provided by the present invention;

[0050] Figure 7 The accompanying drawing is a schematic diagram of the structure of step S4 in the detection method provided by the present invention;

[0051] Figure 8 The accompanying drawing is a schematic diagram of the structure of step S5 in the detection method provided by the present invention;

[0052] Fig. 9The attached drawing is a curve diagram of the detection force and displacement of the prestressed steel strand provided by the present invention.

[0053] in:

[0054] 1- Concrete structure;

[0055] 2- Prestressed steel strand;

[0056] 3-pressure plate;

[0057] 4-Measurable force anchor;

[0058] 41-Measurable force anchor ring;

[0059] 42-force measurable wedge-shaped clamp;

[0060] 5-Steel strand for force measurement;

[0061] 6-Connect the anchor;

[0062] 61-connecting anchor ring;

[0063] 62-connecting wedge-shaped clip;

[0064] 7-Force application component;

[0065] 71-reaction frame;

[0066] 711-round steel pipe;

[0067] 712-force diffusion steel plate;

[0068] 7121-first through hole;

[0069] 713-end round steel plate;

[0070] 7131-second through hole;

[0071] 714-triangular stiffening plate;

[0072] 72-pressure sensor;

[0073] 73- tension jack;

[0074] 74-Electronic displacement meter;

[0075] 8-Data acquisition system. DETAILED DESCRIPTION

[0076] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0077] Embodiment 1:

[0078] See attached Figure 1 The embodiment of the present invention discloses a single-hole clip anchor with measurable force for prestressing, which is used for tensioning and anchoring a prestressed steel strand 2 in a concrete structure 1; it comprises: a pressure plate 3 and a measurable force anchor 4;

[0079] The pressure plate 3 is sleeved on the prestressed steel strand 2 and fits the end surface of the concrete structure 1;

[0080] The measurable force anchor 4 includes a measurable force anchor ring 41 and a measurable force wedge-shaped clip 42; the measurable force anchor ring 41 is sleeved on the end of the prestressed steel strand 2 and has an external thread on the outside; the measurable force wedge-shaped clip 42 is tightened between the side wall of the end of the prestressed steel strand 2 and the measurable force anchor ring 41, and the measurable force anchor ring 41 is pressed against the pressure plate 3.

[0081] like Figure 1 As shown in , when the prestressed steel strand 2 does not need to be tested for prestress, the prestressed steel strand 2 can be anchored after being tensioned.

[0082] When the prestressed steel strand 2 needs to be measured, the concrete sealing the anchor is removed, such as Figure 1 to Figure 2 The force can be measured in the following way.

[0083] Embodiment 2:

[0084] See attached Figure 2 and attached Figure 3 The embodiment of the present invention discloses a prestress value force measuring device connected to a prestress force-measurable single-hole clip anchor, comprising: a force-measuring steel strand 5, a connecting anchor 6, a force-applying component 7 and a data acquisition system 8;

[0085] The end of the force measuring steel strand 5 corresponds to the end of the prestressed steel strand 2 and is coaxially arranged to extend in the opposite direction of the concrete structure 1;

[0086] The connecting anchor 6 comprises a connecting anchor ring 61 and a connecting wedge-shaped clip 62; the connecting anchor ring 61 is sleeved on the end of the force measuring steel strand 5, and the end has an internal thread and is threadedly connected with the force measuring anchor ring 41; the connecting wedge-shaped clip 62 is tightened between the side wall of the end of the force measuring steel strand 5 and the connecting anchor ring 61;

[0087] The force-applying assembly 7 is located at the end surface of the concrete structure 1 and is connected to the extended force-measuring steel strand 5, and is used to apply tension to the force-measuring steel strand 5 and detect its force value and displacement value;

[0088] The data acquisition system 8 is used to collect the force value and displacement value detected by the force application component 7.

[0089] In order to further optimize the above technical solution, the force-applying assembly 7 includes a reaction frame 71, a pressure sensor 72, a tensioning jack 73 and an electronic displacement meter 74; the reaction frame 71 passes through the force-measuring steel strand 5 and fits against the end face of the concrete structure 1; the pressure sensor 72 passes through the force-measuring steel strand 5 and presses against the reaction frame 71; the tensioning jack 73 passes through the force-measuring steel strand 5 and presses against the pressure sensor 72, and the tensioning jack 73 is connected to the force-measuring steel strand 5; the electronic displacement meter 74 is installed at the exposed part of the oil cylinder of the tensioning jack 73.

[0090] In order to further optimize the above technical solution, the data acquisition system 8 is electrically connected to the pressure sensor 72 and the electronic displacement meter 74 respectively.

[0091] In order to further optimize the above technical solution, the reaction frame 71 includes a round steel pipe 711, a force diffusion steel plate 712, an end round steel plate 713 and a triangular stiffening plate 714; the round steel pipe 711 is coaxially sleeved on the outside of the force measuring steel strand 5; the force diffusion steel plate 712 is fixed to the end of the round steel pipe 711, and has a first through hole 7121 for passing the force measuring steel strand 5, and fits with the end face of the concrete structure 1; the end round steel plate 713 is fixed to the other end of the round steel pipe 711, and has a second through hole 7131 for passing the force measuring steel strand 5; there are multiple triangular stiffening plates 714, which are fixed between the outer wall of the round steel pipe 711 and the force diffusion steel plate 712.

[0092] In order to further optimize the above technical solution, the length of the round steel pipe 711 is 120mm-150mm, the wall thickness is 6mm-8mm, and the inner diameter is 5mm-10mm larger than the outer diameter of the connecting anchor ring 61; the thickness of the force diffusion steel plate 712 is 16mm-20mm, and the inner diameter of the first through hole 7121 is 5mm-10mm larger than the outer diameter of the connecting anchor ring 61; the outer diameter of the end round steel plate 713 is 10mm larger than the outer diameter of the round steel pipe 711, and the thickness is 10mm; the number of triangular stiffening plates 714 is 3-4.

[0093] In order to further optimize the above technical solution, the length of the prestressed steel strand 2 exposed from the end surface of the concrete structure 1 is greater than 5 mm.

[0094] In order to further optimize the above technical solution, the force measuring steel strand 5 has the same specifications as the engineering steel strand and a length of 500mm-600mm.

[0095] In order to further optimize the above technical solution, the length of the threaded connection between the anchor ring 61 and the force-measurable anchor ring 41 is 13 mm-15 mm.

[0096] In order to further optimize the above technical solution, a cavity is formed inside the connecting anchor ring 61 and the force-measurable anchor ring 41 after they are connected.

[0097] The detection method of the prestressed force-measurable single-hole clip anchor connection device provided in this embodiment includes the following steps:

[0098] S1. See Appendix Figure 4 , the prestressed steel strand 2 is partially clamped and anchored out of the concrete structure 1 through the force-measurable anchor ring 41 and the force-measurable wedge-shaped clamping piece 42, so that the force-measurable anchor ring 41 clamps the prestressed steel strand 2 and presses against the pressure plate 3;

[0099] S2. See Appendix Figure 5 , clamp and anchor one end of the force measuring steel strand 5 by connecting the anchor ring 61 and the connecting wedge-shaped clamp 62; the force measuring steel strand 5 has the same specifications as the engineering steel strand, with a length of 500mm-600mm, which can meet the subsequent tensioning length;

[0100] S3. See Appendix Figure 6 , connect the connecting anchor ring 61 and the force-measurable anchor ring 41 by thread and tighten them. Tightening the threads by about 13mm-15mm can meet the detection force requirement;

[0101] S4. See Appendix Figure 7 , the reaction frame 71 is coaxially sleeved on the outside of the force-measuring steel strand 5 and is close to the end face of the concrete structure 1; the reaction frame 71 includes a round steel pipe 711, a force diffusion steel plate 712, an end round steel plate 713 and a triangular stiffening plate 714; the round steel pipe 711 is coaxially sleeved on the outside of the force-measuring steel strand 5; the force diffusion steel plate 712 is fixed to the end of the round steel pipe 711, and has a first through hole 7121 that passes through the force-measuring steel strand 5, and fits with the end face of the concrete structure 1; the end round steel plate 713 is fixed to the other end of the round steel pipe 711, and has a second through hole 7131 for the force-measuring steel strand 5 to pass through; the triangular stiffening plate 7 There are multiple 14, which are fixed between the outer wall of the round steel pipe 711 and the force diffusion steel plate 712; the length of the round steel pipe 711 is 120mm-150mm, the wall thickness is 6mm-8mm, and the inner diameter is 5mm-10mm larger than the outer diameter of the connecting anchor ring 61; the thickness of the force diffusion steel plate 712 is 16mm-20mm, and the inner diameter of the first through hole 7121 is 5mm-10mm larger than the outer diameter of the connecting anchor ring 61; the outer diameter of the end round steel plate 713 is 10mm larger than the outer diameter of the round steel pipe 711, and the thickness is 10mm; the number of triangular stiffening plates 714 is 3-4; all steel plates are welded and fixed;

[0102] S5. See Appendix Figure 7 , a pressure sensor 72 and a tensioning jack 73 are sequentially installed on the force measuring steel strand 5, and an electronic displacement meter 74 is installed at the exposed position of the cylinder of the tensioning jack 73;

[0103] S6. See Appendix Figure 8 , connecting the values ​​of the pressure sensor 72 and the electronic displacement meter 74 to the data acquisition system 8;

[0104] S7, perform tensioning test, the oil cylinder of the tensioning jack 73 begins to extend, the pressure sensor 72 begins to generate pressure value, and the data is read and recorded;

[0105] S8. During the tension test, a tension-displacement curve is drawn. When a turning point appears in the tension-displacement curve and the slope decreases significantly, the force value at the turning point is the detected prestress value.

[0106] S9, stop testing, unload the tensioning jack 73, remove the tensioning jack 73, the electronic displacement meter 74, the pressure sensor 72 and the reaction frame 71, unscrew the force measuring steel strand 5 and the connecting anchor 6, and complete the prestressing test of one prestressed tendon.

[0107] See attached Fig. 9 The force-displacement curve of a prestressed steel strand is shown in the figure. It can be found that when the force is 155KN, the force-displacement curve has an obvious turning point, and it can be judged that the prestress value is 155KN.

[0108] In this specification, each embodiment is described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the embodiments can be referred to each other. For the device disclosed in the embodiment, since it corresponds to the method disclosed in the embodiment, the description is relatively simple, and the relevant parts can be referred to the method part.

[0109] The above description of the disclosed embodiments enables one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A prestress value force measuring device connected to a prestressing force-measurable single-hole clip anchor, characterized in that: include: A force measuring steel strand (5), a connecting anchor (6), a force applying component (7) and a data acquisition system (8); A single-hole clip anchor with measurable force for prestressing, used for tensioning and anchoring prestressed steel strands (2) in a concrete structure (1); comprising: a pressure plate (3) and a measurable force anchor (4); The pressure-bearing plate (3) is sleeved on the prestressed steel strand (2) and is in contact with the end surface of the concrete structure (1); The force-measurable anchor (4) comprises a force-measurable anchor ring (41) and a force-measurable wedge-shaped clip (42); the force-measurable anchor ring (41) is sleeved on the end of the prestressed steel strand (2) and has an external thread on the outside; the force-measurable wedge-shaped clip (42) is tightened between the side wall of the end of the prestressed steel strand (2) and the force-measurable anchor ring (41), and the force-measurable anchor ring (41) is pressed against the pressure plate (3); The end of the force measuring steel strand (5) corresponds to the end of the prestressed steel strand (2), and is coaxially arranged to extend in the opposite direction of the concrete structure (1); The connecting anchor (6) comprises a connecting anchor ring (61) and a connecting wedge-shaped clamp (62); the connecting anchor ring (61) is sleeved on the end of the force measuring steel strand (5), and the end has an internal thread and is threadedly connected to the force measuring anchor ring (41); the connecting wedge-shaped clamp (62) is tightened between the side wall of the end of the force measuring steel strand (5) and the connecting anchor ring (61); The force-applying assembly (7) is located on the end surface of the concrete structure (1) and is connected to the extended force-measuring steel strand (5), and is used to apply tension to the force-measuring steel strand (5) and detect its force value and displacement value; The data acquisition system (8) is used to acquire the force value and displacement value detected by the force application component (7); The force measurement steel strand (5) has the same specifications as the engineering steel strand and has a length of 500 mm to 600 mm; The threaded connection length of the connecting anchor ring (61) and the force-measurable anchor ring (41) is 13 mm to 15 mm.

2. A prestress value force measuring device connected to a prestress force-measurable single-hole clip anchor according to claim 1, characterized in that: The force-applying assembly (7) comprises a reaction frame (71), a pressure sensor (72), a tensioning jack (73) and an electronic displacement meter (74); the reaction frame (71) passes through the force-measuring steel strand (5) and is in contact with the end surface of the concrete structure (1); the pressure sensor (72) passes through the force-measuring steel strand (5) and is pressed against the reaction frame (71); the tensioning jack (73) passes through the force-measuring steel strand (5) and is pressed against the pressure sensor (72), and the tensioning jack (73) is connected to the force-measuring steel strand (5); and the electronic displacement meter (74) is installed at the exposed portion of the oil cylinder of the tensioning jack (73).

3. A prestress value force measuring device connected to a prestress force-measurable single-hole clip anchor according to claim 2, characterized in that: The data acquisition system (8) is electrically connected to the pressure sensor (72) and the electronic displacement meter (74) respectively.

4. A prestress value force measuring device connected to a prestress force-measurable single-hole clip anchor according to claim 2 or 3, characterized in that: The reaction frame (71) comprises a round steel pipe (711), a force diffusion steel plate (712), an end round steel plate (713) and a triangular stiffening plate (714); the round steel pipe (711) is coaxially sleeved on the outside of the force-measuring steel strand (5); the force diffusion steel plate (712) is fixed to the end of the round steel pipe (711), has a first through hole (7121) for passing the force-measuring steel strand (5), and is fitted with the end surface of the concrete structure (1); the end round steel plate (713) is fixed to the other end of the round steel pipe (711), has a second through hole (7131) for passing the force-measuring steel strand (5); the triangular stiffening plates (714) are multiple in number and are fixed between the outer wall of the round steel pipe (711) and the force diffusion steel plate (712).

5. A prestress value force measuring device connected to a prestress force-measurable single-hole clip anchor according to claim 4, characterized in that: The length of the round steel pipe (711) is 120 mm to 150 mm, the wall thickness is 6 mm to 8 mm, and the inner diameter is 5 mm to 10 mm larger than the outer diameter of the connecting anchor ring (61); the thickness of the force diffusion steel plate (712) is 16 mm to 20 mm, and the inner diameter of the first through hole (7121) is 5 mm to 10 mm larger than the outer diameter of the connecting anchor ring (61); the outer diameter of the end round steel plate (713) is 10 mm larger than the outer diameter of the round steel pipe (711), and the thickness is 10 mm; the number of the triangular stiffening plates (714) is 3 to 4.

6. A prestress value force measuring device connected to a prestress force-measurable single-hole clip anchor according to claim 1, characterized in that: The length of the prestressed steel strand (2) exposed from the end surface of the concrete structure (1) is greater than 5 mm.

7. A method for detecting a prestress value force measuring device connected to a prestress force-measurable single-hole clip anchor according to any one of claims 1 to 6, characterized in that: The following steps are involved: S1, clamping and anchoring the portion of the prestressed steel strand (2) exposed from the concrete structure (1) by means of a force-measurable anchor ring (41) and a force-measurable wedge-shaped clamp (42), so that the force-measurable anchor ring (41) clamps the prestressed steel strand (2) and presses against the pressure plate (3); S2, clamping and anchoring one end of the force measuring steel strand (5) by connecting the anchor ring (61) and the wedge-shaped clamping piece (62); S3, threading the connecting anchor ring (61) and the force-measurable anchor ring (41) and tightening them; S4, connecting the force-applying assembly (7) to the outside of the force-measuring steel strand (5), applying a tensile force to the force-measuring steel strand (5) and detecting its force value and displacement value; S5, perform tension testing, start generating pressure values, and read and record data; S6. During the tension test, a tension-displacement curve is drawn. When a turning point appears in the tension-displacement curve and the slope decreases significantly, the force value at the turning point is the detected prestress value. S7, stop the test, unload the force-applying assembly (7), unscrew the force-measuring steel strand (5) and the connecting anchor (6), and the prestressing test of one prestressed tendon is completed.

Images