Prefabricated prestressed tendon fracture test device and test method

Abstract

The present invention relates to the field of civil engineering technology, and specifically refers to an assembled prestressed tendon fracture test device and test method. It includes a test block, a tensioning structure, a tensioning groove block, a standard block, a protective structure and a monitoring structure. The test block is a reinforced concrete block used to simulate the use environment of the prestressed tendons to be tested; the tensioning structure is a force-applying structure used to apply tensioning force to the prestressed tendons; the tensioning groove block is a reinforced concrete block connected to the tensioning structure; a plurality of standard blocks are fixed between the test block and the tensioning groove block to form a reinforced concrete test body adapted to the length of the prestressed steel bars; the protective structure is arranged at both ends of the reinforced concrete test body; the monitoring structure is used to monitor vibration, damage and splashing during the test; the test device of the present application has a simple structure and is easy to operate and use, which reduces the difficulty and cost of making a concrete model, and greatly improves the safety and accuracy of the test.

Description

Technical Field

[0001] The invention relates to the technical field of civil engineering, and in particular to an assembled prestressed tendon fracture test device and a test method. Background Art

[0002] As a commonly used prestressed steel bar in engineering, fine-rolled threaded steel bar is widely used in the engineering industry. For example, it is used as an anti-crack anchor in the anchorage area of ​​the cable-stayed cable of the main tower of a cable-stayed bridge, and as a vertical prestressed steel bar in the box girder of a continuous beam bridge to improve the vertical shear resistance of the box girder. Although it has a wide range of uses, it is easy to break during construction and use. After breaking, it will break through the anchor structure and pop out, which is very harmful if it falls.

[0003] In order to prevent secondary disasters caused by the fracture of fine-rolled rebar, its protective measures need to be studied. For example, the Chinese invention patent with the patent number "CN202011125104.7" named "Test device and method for impact protection of prestressed steel bars in the anchorage area of ​​cable-stayed bridge towers". The test device introduced in this patent belongs to the technical field of impact protection test of cable-stayed bridges, including a loading device, a concrete model, a tensioning mechanism, a tensioning pedestal, a high-speed camera and a collector. The tensioning pedestal is distributed on the side wall of the concrete model in a semi-enclosed form, and multiple tensioning mechanisms and loading devices are installed on the tensioning pedestal. The extension lines of multiple tensioning mechanisms are distributed vertically and horizontally and connected to the concrete model. A high-speed camera is arranged obliquely above the concrete model. The high-speed camera, tensioning mechanism and loading device are all electrically connected to the collector. The test device introduced in this patent can complete the impact protection test of prestressed steel bars, which can provide a good theoretical basis for the selection of prestressed steel bars. However, this test device has many problems. This test device is based on the structure of the cable tower anchorage area to make a specific model, and the test is a destructive test. The model is a disposable component. A single model is only suitable for a specific test object. In practice, different bridge towers, different box girders, different anti-floating anchor rods and different wind power steel towers have different sizes. The corresponding prestressed steel bars are of different lengths and fracture positions. The entire protection test is poor in economy and is very environmentally unfriendly. Especially for bridge structures, which are large in size, installation and removal are also a considerable expense. Therefore, there is an urgent need for a reusable, green and environmentally friendly prestressed steel protection test method and system. Summary of the invention

[0004] The purpose of the present invention is to solve the deficiencies of the above-mentioned background technology and to provide an assembled prestressed tendon fracture test device and a test method.

[0005] The technical solution of the present invention is: an assembled prestressed tendon fracture test device, comprising:

[0006] A test block, wherein the test block is a reinforced concrete block used to simulate the use environment of the prestressed tendons to be tested, and a first through hole is provided on the test block for the prestressed tendons to pass through and is fixedly connected to one end of the prestressed tendons;

[0007] A tensioning structure, wherein the tensioning structure is a force-applying structure connected to the other end of the prestressed tendon and used to apply a tensioning force to the prestressed tendon;

[0008] A tensioning groove block, which is a reinforced concrete block connected to the tensioning structure, and is provided with a plurality of second through holes for the prestressed tendons to pass through;

[0009] A plurality of standard blocks, wherein the plurality of standard blocks are fixed between the test block and the tensioning groove block to form a reinforced concrete test body adapted to the length of the prestressed steel bars, and a plurality of third through holes for the prestressed steel bars to pass through are opened on the standard blocks;

[0010] A protective structure, which is arranged at both ends of the reinforced concrete test body to block flying debris generated during the test;

[0011] A monitoring structure, wherein the monitoring structure is used to monitor vibration, damage and splash during the test;

[0012] The first through hole, the second through hole and the third through hole correspond to each other one by one in the prestressed length direction and are connected.

[0013] According to an assembled prestressed tendon fracture test device provided in the present application, the monitoring structure comprises:

[0014] Internal damage sensors, the internal damage sensors comprising linear sensors cast in the test block, the standard block and the tensioning groove block; the linear sensors cast in a single block comprise a plurality of longitudinal parts perpendicular to the prestressed tendons in the horizontal direction and transverse parts connecting adjacent longitudinal parts;

[0015] The connecting nodes are arranged between adjacent blocks and are used to connect the ends of the longitudinal parts extending from the adjacent blocks.

[0016] According to an assembled prestressed tendon fracture test device provided in the present application, the monitoring structure comprises:

[0017] A plurality of external vibration sensors are arranged at the upper end of the standard block, including at least one external vibration sensor arranged on the standard block adjacent to the test block, and at least one external vibration sensor arranged at the upper end of the joint of adjacent standard blocks.

[0018] According to an assembled prestressed tendon fracture test device provided in the present application, the monitoring structure comprises:

[0019] A plurality of internal vibration sensors are cast in the standard block, including at least one internal vibration sensor arranged in the standard block adjacent to the test block and at least one internal vibration sensor arranged in the joint of adjacent standard blocks.

[0020] According to an assembled prestressed tendon fracture testing device provided by the present application, the external vibration sensor and the internal vibration sensor are arranged overlapping in the vertical direction.

[0021] According to the assembled prestressed tendon fracture test device provided by the present application, the monitoring structure further includes:

[0022] A high-speed camera is located between the test block and a protective structure close to one side of the test block, and is used to monitor splashing during the test.

[0023] According to an assembled prestressed tendon fracture test device provided in the present application, the protective structure comprises:

[0024] Two sets of baffles, the two sets of baffles are respectively disposed on a side of the test block away from the standard block and a side of the tensioning groove block away from the standard block;

[0025] Protective sandbags are stacked on the side of the baffle facing the standard block.

[0026] According to an assembled prestressed tendon fracture test device provided in the present application, the protective structure comprises:

[0027] A protective plate, the protective plate is glued and fixed to a portion of the outer side of the test block directly facing the first through hole;

[0028] A protective sheet is adhered and fixed to an end surface of the test block which is away from the standard block.

[0029] According to an assembled prestressed tendon fracture test device provided in the present application, the tensioning structure comprises:

[0030] A bracket, wherein the bracket is arranged between the tensioning groove block and the protective structure close to one side of the tensioning groove block;

[0031] The tensioning jack is installed on the bracket and corresponds one by one to the second through holes on the tensioning slot block.

[0032] According to an assembled prestressed tendon fracture test device provided in the present application, the adjacent test blocks, standard blocks and tensioning groove blocks are fixed as a whole by arc bolts.

[0033] According to an assembled prestressed tendon fracture test device provided by the present application, mutually engaging bosses and grooves are arranged on the adjacent end faces of the adjacent test blocks, standard blocks and tensioning groove blocks; and vibration-proof rubber is arranged between the bosses and grooves.

[0034] The present application also provides a method for testing the fracture of prestressed steel bars. The method is carried out using the above-mentioned test device for testing the fracture of prestressed steel bars, and is carried out according to the following steps:

[0035] S1. Select the appropriate number of standard blocks according to the length of the prestressed tendons;

[0036] S2. Cast the test block according to the test requirements, and perform fracture protection reinforcement on the test block after the test block is cured;

[0037] S3, assembling the test block, the standard block and the tensioning groove block into a reinforced concrete test body;

[0038] S4. Arrange protective structures at both ends of the reinforced concrete test body, install tension structures, and arrange monitoring structures;

[0039] S5, start the tensioning structure to carry out the tensioning fracture test of the prestressed tendons, and monitor the structure to record the test data;

[0040] S6. After the test is completed, remove the damaged test block and perform the next prestressed tendon fracture test according to the above steps.

[0041] According to a prefabricated prestressed tendon fracture test method provided in the present application, in step S2, the method for performing fracture protection reinforcement on the test block after the test block is cured includes: pasting a protective plate at a position corresponding to the first through hole on a side of the test block away from the standard block, and pasting a protective sheet on a side of the test block away from the standard block.

[0042] According to a prefabricated prestressed tendon fracture test method provided by the present application, in step S4, the method of arranging the monitoring structure includes: during the casting process of the test block, the standard block and the tensioning groove block, a linear sensor for monitoring the internal damage is pre-embedded inside the block, an internal vibration sensor for monitoring the internal vibration is pre-embedded inside the standard block adjacent to the test block and at the joint between two adjacent standard blocks, an external vibration sensor for monitoring the external vibration is pre-embedded at the upper end of the standard block adjacent to the test block and at the upper end of the joint between two adjacent standard blocks; after the test block, the standard block and the tensioning groove block are assembled, the linear sensors between adjacent blocks are connected using connecting nodes.

[0043] The advantages of the present application are as follows: 1. The test device of the present application forms a reinforced concrete block for the test through a test block, a standard block and a tensioning groove block, which can be adjusted and combined accordingly according to the length of the prestressed tendon. During the test, only the test block will be damaged, and the standard block and the tensioning groove block can be reused, which reduces the difficulty and cost of making the test model. By setting up a special protective structure, a good protective effect can be achieved. The entire test is very economical and environmentally friendly. The monitoring structure can accurately monitor the vibration, damage and splashing during the test, which is convenient for accurate analysis of the prestressed tendon fracture test.

[0044] 2. The monitoring structure of the present application includes an internal damage sensor, which is cast inside the block and can accurately obtain the damage condition inside the block. In addition, the linear sensor of the present application has a connection node on the outside of the block, and the linear sensors inside the block can be conveniently connected in series through the connection node. The installation method is simple and easy to use.

[0045] 3. This application provides an external vibration sensor on the standard block. The external vibration sensor is used to monitor the vibration during the entire test process from the outside. The external vibration sensor is installed on the standard block and can be reused. It is not easy to be damaged. It can accurately obtain the external vibration during the test and provide good data support for the accurate analysis of the prestressed tendon fracture test.

[0046] 4. The present application provides an internal vibration sensor inside the standard block, which is used to monitor the vibration of the standard block from the inside. The standard block is not easily damaged, and the internal vibration sensor can be reused for a long time, which is convenient for accurately obtaining the internal vibration during the test. In combination with the external vibration sensor, the vibration of the prestressed tendon fracture test can be accurately analyzed;

[0047] 5. The external vibration sensor and the internal vibration sensor of the present application are arranged overlappingly in the vertical direction. In the length direction of the prestressed tendon, the two are equivalent to being in the same position. The external vibration and internal vibration signals during the test are collected respectively, and then analyzed one by one. They can be mutually verified, and the analysis results are more accurate;

[0048] 6. This application sets a high-speed camera on one side of the test block. The high-speed camera is used to capture the splashing debris during the fracture of the prestressed tendons, which can be used to analyze the fracture of the prestressed tendons;

[0049] 7. The protective structure of the present application includes baffles and protective sandbags, which are located at both ends of the reinforced concrete block, that is, at both ends of the length direction of the prestressed tendons, and can effectively block the splashing debris generated during the test to avoid safety accidents. The protective structure is simple to install and arrange and can be reused.

[0050] 8. The protective structure of the present application also includes a protective plate and a protective sheet installed on the test block. The protective plate and the protective sheet are made of carbon fiber and can play a certain interception role. In addition, the fracture of the prestressed tendons can also be analyzed through the damage of the protective plate and the protective sheet;

[0051] 9. The tensioning structure of the present application is very simple. The prestressed tendon fracture test can be completed by applying tensioning force along the length direction to the prestressed tendon through the tensioning jack. The installation and operation of the entire structure are extremely convenient.

[0052] 10. The present application connects adjacent blocks into one by means of bent arc bolts. This connection method is simple. The arc bolts are inside the blocks. During the test, even if damage occurs, the arc bolts will not splash around, which is safer.

[0053] 11. The present application sets bosses and grooves between adjacent blocks to engage with each other, which facilitates the connection of adjacent blocks. In addition, anti-vibration rubber is added between the bosses and grooves to protect the standard blocks and tensioning groove blocks, avoiding damage caused by vibration forces generated during the test;

[0054] 12. The test method of the present application is extremely simple. For each test, only a small test block corresponding to the end of the prestressed tendon needs to be produced. Most of the block structures of the entire test model can be repeatedly used. The test cost of the entire test method has been greatly reduced, the test difficulty has also been reduced, the test is easier to conduct, and the accuracy of the test has also been guaranteed;

[0055] 13. This application can not only intercept the flying debris generated during the test by sticking and fixing the protective plate and protective sheet on the test block, but also analyze the prestressed tendon rupture by the damage of the protective sheet and protective plate after the test is completed;

[0056] 14. The present application arranges a variety of monitoring structures on the reinforced concrete block, including sensors for monitoring the internal vibration, external vibration, and internal damage of the reinforced concrete block. Through these monitoring devices, accurate data analysis can be performed for the prestressed tendon fracture test, and quantitative analysis of the prestressed tendon fracture situation can be performed, providing good theoretical support for the selection of prestressed tendons.

[0057] The test device of the present application has a simple structure and is easy to operate and use, which reduces the difficulty and cost of making a concrete model, greatly improves the safety and accuracy of the test, and has great promotion value. BRIEF DESCRIPTION OF THE DRAWINGS

[0058] Figure 1 : Schematic diagram of the structure of the test device of this application (side view);

[0059] Figure 2 : Schematic diagram of the structure of the test device of the present application (viewed from above);

[0060] Figure 3 : Schematic diagram of the structure of bosses and grooves between adjacent blocks of the present application;

[0061] Figure 4 : Schematic diagram of the anti-vibration rubber arrangement structure of this application;

[0062] Among them: 1—test block; 2—tensioning groove block; 3—standard block; 4—internal damage sensor; 5—connection node; 6—external vibration sensor; 7—internal vibration sensor; 8—high-speed camera; 9—baffle; 10—protective sandbag; 11—bracket; 12—tensioning jack; 13—boss; 14—groove; 15—anti-vibration rubber; 16—protective plate; 17—protective sheet; 18—arc bolt. DETAILED DESCRIPTION

[0063] The embodiments of the present invention are described in detail below, wherein the same or similar reference numerals throughout represent the same or similar elements or elements with the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, and should not be construed as limiting the present invention.

[0064] In the description of the present invention, it should be understood that the terms "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0065] 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 one or more of the features. In the description of the present invention, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0066] The present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments.

[0067] The present application relates to an assembled prestressed tendon fracture test device and a corresponding test method. Compared with the existing prestressed tendon fracture test device, the test device of the present application is simplified in the production of the reinforced concrete model. The test device of the present application only needs to produce a reinforced concrete block connected at the end of the prestressed tendon to be tested to carry out a complete fracture test. The difficulty and cost of producing the reinforced concrete model have been greatly reduced, and the entire test is easier to carry out.

[0068] Specifically, Figures 1-2 As shown, the test device of the present application includes a test block 1, a tensioning structure, a tensioning groove block 2, a plurality of standard blocks 3, a protective structure and a monitoring structure, wherein the test block 1 is a reinforced concrete block used to simulate the use environment of the prestressed tendons to be tested, and the test block 1 is manufactured and formed according to the reinforced concrete standard under the actual use environment of the prestressed tendons. A first through hole is provided on the test block 1 for the prestressed tendons to pass through and is fixedly connected to one end of the prestressed tendons. The test block 1 is only connected to the end position of the prestressed tendons. During the test, the test block 1 will be destroyed, so a test block 1 corresponding to the prestressed tendons needs to be separately manufactured for each test.

[0069] The tensioning structure is a force-applying structure connected to the other end of the prestressed tendon and used to apply a tensioning force to the prestressed tendon. The tensioning structure is located at the other end of the prestressed tendon and applies a tensioning force to the prestressed tendon along the length direction of the prestressed tendon to complete the fracture test of the prestressed tendon.

[0070] The tensioning groove block 2 is a reinforced concrete block connected to the tensioning structure. A plurality of second through holes for the prestressed tendons to pass through are provided on the tensioning groove block 2. The tensioning groove block 2 is connected to the tensioning structure. The tensioning structure applies a tensioning force to the prestressed tendons and simultaneously applies a directional extrusion force to the tensioning groove block 2. The tensioning groove block 2 is a permanent structure and is not easily damaged.

[0071] A plurality of standard blocks 3 are fixed between the test block 1 and the tensioning groove block 2 to form a reinforced concrete test body adapted to the length of the prestressed steel bar, and a plurality of third through holes are provided on the standard block 3 for the prestressed steel bar to pass through. The number of standard blocks 3 can be selected according to the length of the prestressed steel bar, and the length of the reinforced concrete test body formed by the final test block 1, the standard block 3 and the tensioning groove block 2 is required to be equivalent to the length of the prestressed steel bar. The standard block 3 is also a permanent structure and is rarely damaged during the actual test process. Even if it is damaged, it can be quickly replaced. The standard blocks 3 have uniform specifications and sizes for easy deployment.

[0072] The protective structure is set at both ends of the reinforced concrete test body to block the flying debris generated during the test. During the test, the fragments generated by the prestressed tendon rupture and the test block 1 damage tend to fly along the length direction of the prestressed tendon to the side away from the tensioning structure. In order to prevent the flying fragments from injuring people or damaging surrounding objects, the present application sets a protective structure to protect these fragments.

[0073] The monitoring structure is used to monitor vibration, damage and splash during the test. During the test, it is necessary to monitor the prestressed tendon fracture test to provide data support for the subsequent accurate quantitative analysis of the prestressed tendon fracture.

[0074] The first through hole, the second through hole and the third through hole correspond to each other in the length direction of the prestress and are connected. The prestressed tendons are passed through the first through hole, the second through hole and the third through hole for testing.

[0075] During the specific test, the following steps may be followed: S1, selecting an appropriate number of standard blocks 3 according to the length of the prestressed tendons;

[0076] S2. Casting the test block 1 according to the test requirements is actually casting a reinforced concrete block of the same specification according to the use environment characteristics of the prestressed tendons to be tested; after the curing of the test block 1 is completed, fracture protection reinforcement is performed on the test block 1. The fracture protection reinforcement is mainly to prevent the splashing of fragments generated when the prestressed tendons are broken;

[0077] S3, assemble the test block 1, the standard block 3 and the tensioning groove block 2 into a reinforced concrete test body, wherein the test block 1 is at one end of the prestressed tendon, the tensioning groove block 2 is at the other end of the prestressed tendon, and the standard block 3 is filled in the middle, and then these blocks are interconnected into an integral structure, ensuring that the first through hole, the second through hole and the third through hole are aligned one by one in the length direction of the prestressed tendon, and then the prestressed tendon is passed through the first through hole, the second through hole and the third through hole, and one end of the prestressed tendon is fixedly connected to the first through hole;

[0078] S4. Arrange protective structures at both ends of the reinforced concrete test body, install tensioning structures, connect the other end of the prestressed tendons to the tensioning structures, and arrange monitoring structures;

[0079] S5, start the tensioning structure to carry out the tensioning fracture test of the prestressed tendons, and monitor the structure to record the test data;

[0080] S6. After the test is completed, the damaged test block 1 is removed and the next prestressed tendon fracture test is carried out according to the above steps.

[0081] In some embodiments of the present application, the above-mentioned monitoring structure is optimized. The monitoring structure of this embodiment is used to monitor multiple items, including the internal vibration, external vibration and internal damage of reinforced concrete blocks and the splashing of prestressed tendon broken fragments. These monitoring items can be selected according to actual needs and can also be combined in multiple ways to form a multi-channel monitoring structure.

[0082] The specific monitoring structure includes an internal damage sensor 4, such as Figures 1-2 As shown, the internal damage sensor 4 includes linear sensors cast in the test block 1, the standard block 3 and the tensioning groove block 2. The linear sensors are used to monitor the damage inside the above blocks. The linear sensors are sensors pre-buried in the blocks when the blocks are cast and manufactured. The test block 1 will be damaged, so it needs to be replaced every time the test is carried out. The standard block 3 and the tensioning groove block 2 are not easily damaged, and the linear sensors inside are used for a long time. In actual use, it is necessary to connect the linear sensors of all blocks in series. In this embodiment, a connection node 5 is set between adjacent blocks.

[0083] like Figures 1-2 As shown, the linear sensor cast in a single block includes multiple longitudinal parts perpendicular to the prestressed tendons in the horizontal direction and transverse parts connecting adjacent longitudinal parts. The linear sensors in a single block are arranged in a U-shaped, S-shaped or Z-shaped manner. The damage of the block is mainly caused by the length direction of the vertical prestressed tendons. Therefore, it is necessary to ensure that the longitudinal part can roughly cover the block in the longitudinal direction perpendicular to the prestressing force, so that the damage inside the block during the test can be accurately obtained. The connection node 5 is set between adjacent blocks to connect the ends of the longitudinal parts extending from the adjacent blocks.

[0084] In addition, the monitoring structure also includes a plurality of external vibration sensors 6, such as Figures 1-2 The multiple external vibration sensors 6 shown are arranged at the upper end of the standard block 3, including at least one external vibration sensor 6 arranged on the standard block 3 adjacent to the test block 1, and at least one external vibration sensor 6 arranged at the upper end of the joint of adjacent standard blocks 3.

[0085] In this embodiment, two external vibration sensors 6 are arranged on the upper end surface of the standard block 3. The external vibration sensors 6 are arranged on the upper surface of the standard block 3. The standard block 3 is not easily damaged, and the external vibration sensors 6 can be used repeatedly. One external vibration sensor 6 is located on the standard block 3 adjacent to the test block 1, and the external vibration condition of the test block 1 can be directly obtained. One external vibration sensor 6 is located at the joint between adjacent standard blocks 3, and the external vibration condition at the joint position can be obtained. The two vibration conditions can be compared and analyzed to obtain accurate external vibration conditions during the prestressed tendon fracture test.

[0086] The monitoring structure also includes a plurality of internal vibration sensors 7, such as Figures 1-2 As shown, a plurality of internal vibration sensors 7 are cast in the standard block 3 , including at least one internal vibration sensor 7 arranged in the standard block 3 adjacent to the test block 1 , and at least one internal vibration sensor 7 arranged in the joint of adjacent standard blocks 3 .

[0087] In this embodiment, an internal vibration sensor 7 is arranged inside the standard block 3. For the same reason, the standard block 3 is not easily damaged, the internal vibration sensor 7 can be used repeatedly, and the test cost is reduced. One internal vibration sensor 7 is located inside the standard block 3 adjacent to the test block 1, and the internal vibration sensor 7 can obtain a relatively accurate vibration condition inside the test block 1. Another internal vibration sensor 7 is located inside the joint between adjacent standard blocks 3, and can obtain the internal vibration condition between adjacent blocks during the test. By comparing and analyzing the two, the accurate internal vibration condition during the prestressed tendon fracture test can be obtained.

[0088] In fact, the external vibration sensor 6 and the internal vibration sensor 7 of this embodiment are in one-to-one correspondence, and the external vibration sensor 6 and the internal vibration sensor 7 are arranged overlapping in the vertical direction. The external vibration sensor 6 and the internal vibration sensor 7 at the same length position of the prestressed tendon can be used as a group for data analysis, and accurate results can be obtained by comparing them two by two.

[0089] Furthermore, the monitoring structure of this embodiment also includes a high-speed camera 8, such as Figure 2 As shown, the high-speed camera 8 is located between the test block 1 and the protective structure close to one side of the test block 1, and is used to monitor the splashing during the test.

[0090] During the prestressed tendon fracture test, the fragments generated by the prestressed tendon fracture and the destruction of the test block 1 mainly splash to the side away from the standard block 3. By installing a high-speed camera 8 at this position to shoot the splashing fragments, subsequent analysis of the prestressed tendon fracture test is convenient.

[0091] In other embodiments of the present application, the above-mentioned protective structure is optimized. Figures 1-2 As shown, the protective structure includes two groups of baffles 9 and protective sandbags 10, wherein the two groups of baffles 9 are respectively placed on the side of the test block 1 away from the standard block 3 and the side of the tensioning groove block 2 away from the standard block 3, and the protective sandbags 10 are stacked on the side of the baffle 9 facing the standard block 3. As mentioned above, the fragments generated by the prestressed tendon fracture test are mainly splashed along the length direction of the prestressed tendon to the side away from the standard block 3, so it is necessary to arrange a protective structure on the side of the test block 1 away from the standard block 3. In addition, one side of the tensioning structure is a force unit, and during the test, the problem of fracture splashing may also occur. In order to avoid safety accidents, a protective structure is also arranged on the side of the tensioning groove block 2 away from the standard block 3.

[0092] In addition, the protective structure of this embodiment also includes a protective plate 16 and a protective sheet 17, which are sheet structures made of carbon fiber material, wherein the protective plate 16 is glued and fixed to the outside of the test block 1 at a position facing the first through hole, and the protective sheet 17 is glued and fixed to the end face of the side of the test block 1 away from the standard block 3.

[0093] The protection plate 16 and the protection sheet 17 are provided to intercept the fragments generated by the prestressed fracture and the damage of the test block 1 on the one hand, and on the other hand, after the test is completed, the protection plate 16 and the protection sheet 17 can be observed to analyze the splashing of the fragments, for example, the direction and strength of the splashing of the fragments can be determined by observing the bulging degree or damage of the protection plate 16 and the protection sheet 17.

[0094] In a further embodiment of the present application, the present embodiment optimizes the above-mentioned tensioning structure. Specifically, Figures 1-2 As shown, the tensioning structure includes a bracket 11 and a tensioning jack 12. The bracket 11 is arranged between the tensioning groove block 2 and the protective structure close to one side of the tensioning groove block 2. The tensioning jack 12 is installed on the bracket 11 and corresponds one by one to the second through hole on the tensioning groove block 2.

[0095] The tensioning jack 12 corresponds to the prestressed tendons to be tested one by one. The test block 1 of this embodiment is provided with a plurality of first through holes, and the plurality of first through holes correspond to the prestressed tendons one by one. A fracture test of a prestressed tendon can be carried out in each first through hole. Figure 2 As shown, the first through holes in this embodiment include three groups. The middle group is a large-diameter hole, which can be used to carry out tension tests on large-tonnage rods, such as multiple bundles of steel strands and large-diameter alloy prestressed rods; there is a group on each side, which is used for fracture tests of conventional prestressed tendons.

[0096] In the preferred embodiment of the present application, the connection structure of the above blocks is optimized. Figures 1-2As shown, the adjacent test blocks 1, standard blocks 3 and tensioning groove blocks 2 are fixed as a whole by arc bolts 18. The connecting end faces of the test blocks 1, standard blocks 3 and tensioning groove blocks 2 of this embodiment are straight rectangular end faces. In this embodiment, there are connecting through holes at the connecting end faces of the adjacent blocks. When in use, after the adjacent blocks are fitted together, the connecting through holes on the connecting end faces correspond to each other. The arc bolts 18 are passed through the connecting through holes connected together, and the adjacent blocks can be connected as a whole by tightening the bolts. A group of arc bolts 18 is provided at each connecting end face, that is, four groups of arc bolts 18 are required to connect the adjacent blocks as a whole, and the four groups of arc bolts 18 are placed at the four corners of the connecting end faces. After the arc bolts 18 are installed, they are in the structure of the block. During the test, even if they are damaged, they will not splash outward, and the safety of the test is guaranteed.

[0097] In order to facilitate the connection of adjacent blocks, in this embodiment, mutually engaging bosses 13 and grooves 14 are provided on the adjacent end faces of the adjacent test blocks 1, standard blocks 3 and tensioning groove blocks 2. Figure 3 and 4 As shown, an anti-vibration rubber 15 is arranged between the boss 13 and the groove 14 .

[0098] During installation, the bosses 13 and the grooves 14 of the adjacent blocks are aligned and then snapped together to complete the preliminary connection of the adjacent blocks. The anti-vibration rubber 15 is squeezed between the bosses 13 and the grooves 14.

[0099] In actual testing, according to the length of the prestressed tendons, a suitable number of standard blocks 3 are selected, and then reinforced concrete blocks of the same specifications are cast according to the use environment of the prestressed tendon ends, namely, test blocks 1. After the test block 1 is cured, fracture protection reinforcement is performed on the test block 1, specifically, a protective plate 16 is pasted on the position corresponding to the first through hole on the side of the test block 1 away from the standard block 3, and a protective sheet 17 is pasted on the side of the test block 1 away from the standard block 3;

[0100] Then, the test block 1, the standard block 3 and the tensioning groove block 2 are assembled together, the bosses 13 and the grooves 14 of the adjacent blocks are aligned and snapped together, and then the arc bolts 18 are inserted into the connecting through holes at the connecting end faces of the adjacent blocks, and the nuts are tightened to connect the test block 1, the standard block 3 and the tensioning groove block 2 into a reinforced concrete block that meets the requirements for the length of the prestressed tendons;

[0101] At this time, the first through hole, the second through hole and the third through hole on the reinforced concrete block are aligned, and the prestressed tendons are inserted into the through holes at the desired test positions, and one end of the prestressed tendons is fixed to the test block 1, and the other end of the prestressed tendons passes through the reinforced concrete block and extends to one side of the tensioning structure, and then is connected to the tensioning jack 12 at the corresponding position;

[0102] During the casting process of the test block 1, the standard block 3 and the tensioning groove block 2, a linear sensor for monitoring internal damage is embedded in the block, an internal vibration sensor 7 for monitoring internal vibration is embedded in the inside of the standard block 3 adjacent to the test block 1 and in the joint between two adjacent standard blocks 3, and an external vibration sensor 6 for monitoring external vibration is embedded in the upper end of the standard block 3 adjacent to the test block 1 and in the upper end of the joint between two adjacent standard blocks 3. After the test block 1, the standard block 3 and the tensioning groove block 2 are assembled, the linear sensors between adjacent blocks are connected using the connection node 5, and a high-speed camera 8 is arranged on the side of the test block 1 away from the standard block 3;

[0103] The tensioning jack 12 applies tensioning force to the prestressed tendons until the prestressed tendons are broken and the test block 1 is damaged. The internal damage sensor 4 records the damage inside the block during the test. The external vibration sensor 6 and the internal vibration sensor 7 record the vibration inside and outside the block respectively. The high-speed camera 8 takes pictures of the flying debris. The fracture of the prestressed tendons is analyzed in combination with the monitoring data.

[0104] The damaged test block 1 is removed, and then the fracture test of the next prestressed tendon is carried out according to the above process.

[0105] During the test, the standard block 3 may be damaged. In the next test, it can be replaced and adjusted accordingly.

[0106] The above shows and describes the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The above embodiments and descriptions are only for explaining the principles of the present invention. The present invention may be subject to various changes and improvements without departing from the spirit and scope of the present invention. These changes and improvements fall within the scope of the present invention. The scope of protection of the present invention is defined by the attached claims and their equivalents.

Claims

1. An assembled prestressed tendon fracture test device, characterized in that: include, A test block (1), the test block (1) being a reinforced concrete block used to simulate the use environment of the prestressed tendons to be tested, the test block (1) being provided with a first through hole for the prestressed tendons to pass through and fixedly connected to one end of the prestressed tendons; A tensioning structure, wherein the tensioning structure is a force-applying structure connected to the other end of the prestressed tendon and used to apply a tensioning force to the prestressed tendon; A tensioning groove block (2), the tensioning groove block (2) being a reinforced concrete block connected to the tensioning structure, and the tensioning groove block (2) being provided with a plurality of second through holes for the prestressed tendons to pass through; A plurality of standard blocks (3), wherein the plurality of standard blocks (3) are fixed between the test block (1) and the tensioning groove block (2) to form a reinforced concrete test body adapted to the length of the prestressed steel bars, and the standard blocks (3) are provided with a plurality of third through holes for the prestressed steel bars to pass through; A protective structure, which is arranged at both ends of the reinforced concrete test body to block flying debris generated during the test; A monitoring structure, wherein the monitoring structure is used to monitor vibration, damage and splash during the test; The first through hole, the second through hole and the third through hole correspond to each other in the prestressed length direction and are connected; The test blocks will be damaged, but the standard blocks and tension groove blocks can be reused.

2. The assembled prestressed tendon fracture test device according to claim 1, characterized in that: The monitoring structure comprises: An internal damage sensor (4), the internal damage sensor (4) comprising a linear sensor cast in the test block (1), the standard block (3) and the tensioning groove block (2); the linear sensor cast in a single block comprises a plurality of longitudinal portions perpendicular to the prestressed tendons in a horizontal direction and a transverse portion connecting adjacent longitudinal portions; A connecting node (5) is provided between adjacent blocks and is used to connect the ends of the longitudinal portions extending from the adjacent blocks.

3. The assembled prestressed tendon fracture test device according to claim 1, characterized in that: The monitoring structure comprises: A plurality of external vibration sensors (6), wherein the plurality of external vibration sensors (6) are arranged at the upper end of the standard block (3), including at least one external vibration sensor (6) arranged on the standard block (3) adjacent to the test block (1), and at least one external vibration sensor (6) arranged at the upper end of the joint between adjacent standard blocks (3).

4. The assembled prestressed tendon fracture test device according to claim 3, characterized in that: The monitoring structure comprises: A plurality of internal vibration sensors (7), wherein the plurality of internal vibration sensors (7) are cast in a standard block (3), and include at least one internal vibration sensor (7) arranged in a standard block (3) adjacent to a test block (1), and at least one internal vibration sensor (7) arranged in a joint between adjacent standard blocks (3).

5. The assembled prestressed tendon fracture test device according to claim 4, characterized in that: The external vibration sensor (6) and the internal vibration sensor (7) are arranged to overlap in the vertical direction.

6. The assembled prestressed tendon fracture test device according to claim 1, characterized in that: The monitoring structure also includes: A high-speed camera (8) is located between the test block (1) and a protective structure close to one side of the test block (1) and is used to monitor splashing during the test.

7. The assembled prestressed tendon fracture test device according to claim 1, characterized in that: The protective structure comprises: Two groups of baffles (9), the two groups of baffles (9) being respectively disposed on a side of the test block (1) away from the standard block (3) and a side of the tensioning groove block (2) away from the standard block (3); Protective sandbags (10), wherein the protective sandbags (10) are stacked on a side of the baffle (9) facing the standard block (3).

8. The assembled prestressed tendon fracture test device according to claim 1, characterized in that: The tension structure comprises: A bracket (11), wherein the bracket (11) is arranged between the tensioning groove block (2) and a protective structure close to one side of the tensioning groove block (2); A tensioning jack (12), wherein the tensioning jack (12) is mounted on the bracket (11) and corresponds one-to-one with the second through holes on the tensioning slot block (2).

9. A method for testing the fracture of prestressed steel bars, characterized in that: The test method is carried out using an assembled prestressed tendon fracture test device as described in any one of claims 1 to 8, and is carried out according to the following steps: S1. Select an appropriate number of standard blocks (3) according to the length of the prestressed tendons; S2. Casting the test block (1) according to the test requirements, and performing fracture protection reinforcement on the test block (1) after the curing of the test block (1) is completed; S3, assembling the test block (1), the standard block (3) and the tensioning groove block (2) into a reinforced concrete test body; S4. Arrange protective structures at both ends of the reinforced concrete test body, install tension structures, and arrange monitoring structures; S5, start the tensioning structure to carry out the tensioning fracture test of the prestressed tendons, and monitor the structure to record the test data; S6. After the test is completed, the damaged test block (1) is removed and the next prestressed tendon fracture test is carried out according to the above steps.

10. A method for testing the fracture of prestressed steel bars as claimed in claim 9, characterized in that: In the step S4, the method for arranging the monitoring structure comprises: during the casting process of the test block (1), the standard block (3) and the tension groove block (2), a linear sensor for monitoring internal damage is embedded in the block, an internal vibration sensor (7) for monitoring internal vibration is embedded in the interior of the standard block (3) adjacent to the test block (1) and in the joint between two adjacent standard blocks (3), and an external vibration sensor (6) for monitoring external vibration is embedded in the upper end of the standard block (3) adjacent to the test block (1) and in the upper end of the joint between two adjacent standard blocks (3); after the test block (1), the standard block (3) and the tension groove block (2) are assembled, the linear sensors between adjacent blocks are connected using the connection node (5).

Images