A method for detecting the quality of steel bar connection joints

Abstract

The present invention relates to the field of steel bar testing technology, and in particular to a method for testing the quality of steel bar connection joints. The present invention tests the conductivity value of the steel bar connection joint to achieve the judgment and screening of the processing accuracy of the steel bar thread head and the abutment state of the steel bar straight thread thread head in the center of the sleeve, the tensile strength and the residual deformation. The detection method is effective, fast, convenient and reproducible, and can also achieve on-site non-destructive detection.

Description

Technical Field

[0001] The invention relates to the technical field of steel bar testing, and in particular to a method for detecting the quality of steel bar connection joints. Background Art

[0002] A steel bar connection joint refers to a transition section formed by connecting two ends of steel wires with a sleeve when two steel bars are mechanically connected. It includes a sleeve and steel wires screwed into the sleeve at both ends. As the connection point where the steel bars are extended, the quality of the steel bar connection joint is directly related to the stability and seismic performance of the building structure. If the steel bar connection is not firm, it may cause serious problems such as cracks, deformation or even fractures in the structure, and the seismic performance of the building will be greatly reduced.

[0003] The existing quality evaluation standards for steel bar connection joints include the manufacturing accuracy of steel bar wire heads, the tightening degree of steel bar connection joints, the ultimate tensile strength of steel bar connection joints in unidirectional tension, and the residual deformation of steel bars. The detection methods are: go and no-go gauge detection, torque wrench tightening torque detection, ultimate tensile strength detection in unidirectional tension, and residual deformation detection in unidirectional tension. The quality of steel bar connection joints is evaluated by combining the test results of these tests. However, these detection methods are independent of each other and are not only affected by the manual sampling process, but some tests also require destructive sampling, which makes it difficult for the test results to represent the final connection quality. Therefore, a more intuitive and reproducible detection method for the quality of steel bar connection joints is needed. Summary of the invention

[0004] The purpose of the present invention is to overcome the above-mentioned shortcomings and provide a method for detecting the quality of steel bar connection joints, which has the advantages of being effective, fast, convenient and supporting on-site detection.

[0005] To achieve the above object, the technical solution of the present invention is: a method for detecting the quality of a steel bar connection joint, which is used to detect whether the quality of the steel bar connection joint meets the standard; wherein the steel bar connection joint includes a sleeve and two steel wire heads screwed into the sleeve from both ends, and the detection method includes the following steps:

[0006] S1: using a steel bar connection joint testing device to input electrical parameters into the steel bar connection joint and record the values ​​of the electrical parameters;

[0007] S2: Collecting electrical parameter values ​​and detecting electrical response signals of the steel bar connection joints. At this time, the current value and voltage value of the steel bar connection joints are obtained through the electrical parameter values ​​and the electrical response signals. The current value and voltage value are input into the detection system to calculate the conductivity value, and finally the conductivity value Gx of the steel bar connection joint is obtained. The conductivity value calculation formula is: Gx=I / U, where I is the current in the steel bar joint and U is the voltage at the steel bar joint.

[0008] S3: Use the detection system to collect the conductivity value Gx of the steel bar connection joint and calculate and determine the conductivity ratio Gs; wherein, the calculation formula of the conductivity ratio Gs is: Gs=Gx / G1, G1 is the conductivity value of the steel bar original material with the same length as the steel bar connection joint.

[0009] S3.1: When the conductivity ratio is ≥1.3, it indicates that the quality of the steel bar connection joint meets the standards.

[0010] S3.2: When 0.9<conductivity ratio<1.3, it means that at least one of the following three situations exists: insufficient processing precision of steel wire head, unqualified tensile strength of steel bar and unqualified residual deformation, and the quality of steel bar connection joint does not meet the standard.

[0011] S3.3: When the conductivity ratio is ≤0.9, it means that the steel wire head in the sleeve is not abutted or the quality of the steel bar connection joint does not meet the standards, and it is necessary to tighten the operation and repeat the test for further verification; if the conductivity ratio is still not higher than 0.9 after repeated testing, it means that there is at least one of the following three situations: insufficient processing accuracy of the steel wire head, unqualified tensile strength of the steel bar, and unqualified residual deformation, and the quality of the steel bar connection joint does not meet the standards.

[0012] Furthermore, before testing the steel bar connection joints, the conductivity value of the steel bars of the same batch needs to be tested; select steel bars of the same length as the steel bar joints as the test objects, and then repeat steps S1 and S2 to test the steel bars 3-5 times, take the average value of the test to obtain the conductivity value of the steel bar raw material and input it into the detection system for calculation.

[0013] Furthermore, the electrical parameter is current, and the electrical response signal is voltage.

[0014] Furthermore, the steel bar connection joint testing device includes a connecting rod, two input rods, and two detection rods; the two detection rods are arranged between the two input rods and the input rod and the detection rod are vertically connected to the connecting rod; the input rod is connected to an external power supply through a circuit, and the detection rod is connected to an external voltage testing device through a circuit, and the detection rod and the input rod are provided with abutment rings on one end away from the connecting rod, and the abutment ring is used to connect the circuit and the object to be tested, and pressure is applied to the abutment ring so that the object to be tested and the testing device form a closed test loop.

[0015] Furthermore, the abutment ring includes a non-closed shell, an active switch and a conductive component. The non-closed shell is connected to the detection rod or the input rod and is provided with a groove for the active switch to be embedded at the connection point. Two conductive components are respectively arranged on the upper and lower sides of the groove. The upper and lower sides of the active switch are provided with a first contact plate and a reset spring is provided on the side close to the groove; the conductive component includes a second contact plate, a converter and a spring sheet. The second contact plate is arranged in the groove and corresponds to the position of the first contact plate. The converter is connected to the second contact plate and processes the current received by the second contact plate. One end of the spring sheet is connected to the converter, and the other end of the spring sheet passes through the inner ring wall of the non-closed shell. The first contact plate is connected to an external circuit. The abutment ring is squeezed to make the first contact plate contact with the second contact plate and transmit electrical parameters or electrical response signals between the two.

[0016] Furthermore, the spring sheet is an upwardly protruding arc-shaped sheet and the other end of the spring sheet is slidably connected to the inner ring of the non-closed shell.

[0017] Furthermore, the steel bar connection joint testing device also includes a reinforcement component, which includes an electric rope collecter, a fixed rope and a fixed plate. The electric rope collecter is arranged on one side of the connecting rod, and the fixed plate is connected to the connecting rod. A limiting hole is provided on the fixed plate. One end of the fixed rope is connected to the electric rope collecter, and the other end of the fixed rope is detachably connected to the limiting hole. When in use, the fixed rope is made to bypass the object to be tested and connected to the limiting hole, and then the electric rope collecter is started to increase the connection between the abutment ring and the object to be tested.

[0018] Furthermore, the detection system is provided with an information storage module. After receiving the conductivity value of the steel bar raw material, the information storage module stores the conductivity value. At this time, the project name and the steel bar diameter of the steel bar raw material are input and a mapping relationship is formed between them and the conductivity value. For subsequent repeated testing of the steel bar connection joints at different connection points, only the corresponding project name and steel bar diameter need to be input to obtain the corresponding conductivity value of the steel bar raw material.

[0019] Furthermore, the detection system is also provided with a statistical module, which collects the conductivity ratios of the steel bar connection joints at different connections, establishes a steel bar connection model and marks the sleeve conductivity ratios at different connections on the model.

[0020] By adopting the above technical solution, the beneficial effects of the present invention are:

[0021] 1. The present invention realizes on-site evaluation of the quality of steel bar connection joints by testing and calculating the conductivity ratio, and realizes the screening of the quality of steel bar connection joints by judging whether the conductivity ratio falls into a preset range. The testing method is effective, fast, convenient, and reproducible, and non-destructive detection is realized on-site; by setting a statistical module, the collection of each steel bar conductivity value and the steel bar connection joint conductivity ratio is realized, which is convenient for subsequent repeated testing and comprehensive evaluation of the entire project, reduces manual calculation steps, and timely guides joint processing and construction to ensure project quality.

[0022] 2. The present invention sets up a steel bar connection joint test device based on the conductivity ratio test principle, fixes the test length, and reduces the error caused by the change of the test length; by setting an abutment ring, it is ensured that when the device starts the test, the target abutment state can be achieved between the device and the object to be tested, thereby preventing the test error caused by operational errors.

[0023] It is to be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the present disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The accompanying drawings are used to provide further understanding of the present invention and constitute a part of the specification. They are used together with the embodiments of the present invention to explain the present invention and do not constitute a limitation of the present invention.

[0025] In the drawings, the same reference numerals are used for the same components and the drawings are schematic and not necessarily drawn to scale.

[0026] 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 one or several embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on such drawings without paying creative work.

[0027] Figure 1 It is a schematic diagram of the structure of the steel bar connection joint testing device in the present invention in use state;

[0028] Figure 2 It is a side view of the connection between the abutment ring and the input rod;

[0029] Figure 3 A three-dimensional diagram showing the connection between the abutment ring and the input rod;

[0030] Figure 4 It is a schematic diagram of the local internal structure of the abutment ring.

[0031] Description of main reference numerals:

[0032] 1- sleeve;

[0033] 2- Connecting rod;

[0034] 3- Input rod;

[0035] 4-Detection rod;

[0036] 5- abutment ring;

[0037] 51-non-closed housing; 511-groove; 52-active switch; 521-first contact plate; 522-reset spring; 53-conductive component; 531-second contact plate; 532-converter; 533-spring sheet;

[0038] 6-Reinforcement components;

[0039] 61-electric rope retractor; 62-fixing rope; 63-fixing plate; 631-limiting hole. DETAILED DESCRIPTION

[0040] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with specific embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention, but are not used to limit the present invention.

[0041] Before describing the specific implementation of the present invention, it is necessary to know that conductivity is a physical quantity that describes the conductivity of a conductor. Ignoring the influence of ambient temperature, it is affected by the conductor material, cross-sectional area and length. Its definition is:

[0042] G = σS / L;

[0043] Where G is the conductivity value, σ is the conductivity of the conductor, S is the cross-sectional area of ​​the conductor, and L is the length of the conductor;

[0044] Therefore, the conductivity value G1 of the steel bar can be calculated as:

[0045] ;

[0046] Where S=π / 4*D1 2 , D1 is the diameter of the steel bar;

[0047] The conductivity value G2 of the steel bar connection joint is:

[0048] ;

[0049] Where S2=π / 4*D2 2 , D2 is the diameter of the sleeve (i.e. the steel bar connection joint) that contains the steel wire head;

[0050] Assuming that the length and material of the steel bar and the sleeve are the same, taking the steel bar with a diameter of 25 as an example, the diameter of the matching sleeve is 37.5, the conductivity ratio of the steel bar and the sleeve can be calculated as:

[0051] G s25 =G2 / G1=S2 / S1=(D2*D2) / (D1*D1)=(37.5*37.5) / (25*25)=2.25;

[0052] Because the current sleeve is made of stainless steel, the electrical conductivity of stainless steel is higher than that of steel bars. Therefore, when the steel wire head and the sleeve are tightly connected and the two steel wire heads are tightly against each other, the conductivity ratio of the 25 diameter steel bar and its matching sleeve with built-in steel bars should be above 2.25.

[0053] However, in actual projects, due to the influence of the steel bar processing accuracy and the tightness of the steel bar wire head, there will be a gap between the steel bar wire head and the sleeve. The medium of the gap is air, which will cause the conductivity value of the steel bar connection joint to decrease.

[0054] Based on the above principle, the present invention provides a method for detecting the quality of a steel bar connection joint, which is used to detect whether the quality of a steel bar connection joint meets the standard. The steel bar connection joint includes a sleeve 1 and two steel wire heads screwed into the sleeve 1 from both ends. The detection method includes the following steps:

[0055] S1: Use a steel bar connection joint testing device to input electrical parameters into the steel bar connection joint and record the electrical parameter values; the electrical parameters can be any one of direct current, alternating current and electromagnetic induction signal.

[0056] S2: Collect electrical parameter values ​​and detect electrical response signals of the steel bar connection joint, where the electrical response signals can be current values ​​or voltage values. At this time, the current value and voltage value of the steel bar connection joint are obtained through the electrical parameter values ​​and the electrical response signals, and the current value and voltage value are input into the detection system for conductivity value calculation, and finally the conductivity value Gx of the steel bar connection joint is obtained. The conductivity value calculation formula is: Gx=I / U, where I is the current in the steel bar joint and U is the voltage at the steel bar joint.

[0057] S3: Use the detection system to collect the conductivity value Gx of the steel bar connection joint and calculate and determine the conductivity ratio Gs, where the calculation formula of the conductivity ratio Gs is: Gs=Gx / G1, G1 is the conductivity value of the steel bar original material with the same length as the steel bar connection joint.

[0058] S3.1: When the conductivity ratio is ≥1.3, it indicates that the quality of the steel bar connection joint meets the standards.

[0059] S3.2: When 0.9<conductivity ratio<1.3, it means that at least one of the following three situations exists: insufficient processing precision of steel wire head, unqualified tensile strength of steel bar and unqualified residual deformation, and the quality of steel bar connection joint does not meet the standard.

[0060] S3.3: When the conductivity ratio is ≤0.9, it means that the steel wire head in the sleeve is not abutted or the quality of the steel bar connection joint does not meet the standards, and it is necessary to tighten the operation and repeat the test for further verification; if the conductivity ratio is still not higher than 0.9 after repeated testing, it means that there is at least one of the following three situations: insufficient processing accuracy of the steel wire head, unqualified tensile strength of the steel bar, and unqualified residual deformation, and the quality of the steel bar connection joint does not meet the standards.

[0061] Furthermore, it should be noted that the detection system is a well-known detection system, and may adopt a conductivity value calculation system such as that in announcement number CN116840719A, or may adopt other detection systems in existing conductivity value detection equipment. On this basis, the present invention adds an information storage module and a statistical module to the detection system.

[0062] After receiving the conductivity value of the steel bar raw material, the information storage module stores the conductivity value. At this time, the project name and steel bar diameter of the steel bar raw material are input and a mapping relationship is formed between them and the conductivity value. For subsequent repeated testing of the steel bar connection joints at different connection points, only the corresponding project name and steel bar diameter need to be input to obtain the corresponding conductivity value of the steel bar raw material.

[0063] The statistical module collects the conductivity ratios of the steel bar connection joints at different connections, establishes a steel bar connection model and marks the sleeve conductivity ratios at different connections on the model.

[0064] In combination with the above, in S3, the conductivity value of the steel bar of the same length as the steel bar connection joint can be obtained by searching the control system, specifically: input the project name and the steel bar diameter to find the corresponding steel bar conductivity value stored in the processing module. If it cannot be retrieved, the same test equipment is used for on-site testing and recording, specifically: select the same batch, the same length and the steel bar connection joint selected at the test voltage for 3-5 times of conductivity value test, and then take the average value of the test to obtain the conductivity value of the steel bar raw material, and store the conductivity value at the same time, so that it forms a mapping relationship with the project name and the steel bar diameter, which is convenient for subsequent repeated tests for retrieval. Similarly, in order to make the test results more intuitive, a steel bar connection model can also be established by combining a computer with a construction drawing. After each steel bar connection joint is measured, the corresponding position on the model is marked with data to form a statistical module, and the output conclusions of the conductivity ratio are marked with three different colors. If necessary, a sound device or a light-emitting device can be connected for reminder.

[0065] Furthermore, it should be noted that the steel bar connection joint test device can be a temporary measuring device composed of a power supply, a voltmeter, an ammeter and a wire. When the electrical parameter is current, the electrical response signal is voltage; at this time, the steel bar connection joint test device includes a connecting rod 2, two input rods 3, and two detection rods 4. The two detection rods 4 are arranged between the two input rods 3, and the input rods 3 and the detection rods 4 are both vertically connected to the connecting rod 2. The input rod 3 is connected to an external power supply through a circuit, and the detection rod 4 is connected to an external voltage testing device through a circuit. The detection rod 4 and the input rod 3 are both provided with an abutment ring 5 at one end away from the connecting rod 2. The abutment ring 5 is used to connect the circuit and the object to be tested, and pressure is applied to the abutment ring 5 so that the object to be tested and the test device form a closed test loop.

[0066] The abutting ring 5 includes a non-closed housing 51, an active switch 52 and a conductive component 53. The non-closed housing 51 is a ring with a notch. The non-closed housing 51 is connected to the detection rod 4 or the input rod 3 and is provided with a groove 511 at the connection for the active switch 52 to be embedded. Two conductive components 53 are respectively arranged on the upper and lower sides of the groove 511. The upper and lower sides of the active switch 52 are provided with a first contact plate 521 and a reset spring 522 is provided on the side close to the groove 511. The conductive component 53 includes a second contact plate 531, a converter 532 and a spring sheet 533. The second contact plate 531 is arranged in the groove 511 and corresponds to the position of the first contact plate 521. There can be several first contact plates 521, which are arranged in parallel and equidistantly; there are also several second contact plates 531, and their arrangement positions are staggered with the first contact plate 521. The converter 532 connects the second contact plate 531 and processes the current received by the second contact plate 531 so that the current of the second electrical contact plate can reach the spring sheet 533. One end of the spring sheet 533 is connected to the converter 532, and the other end of the spring sheet 533 passes through the inner wall of the non-closed housing 51. The first contact plate 521 is connected to the external circuit, and the abutment ring 5 is squeezed to make the first contact plate 521 contact with the second contact plate 531 and transmit electrical parameters or electrical response signals between the two. At this time, the spring sheet 533 abuts the steel bar. To ensure that the abutment ring 5 and the steel bar can be quickly separated, the spring sheet 533 is an upwardly protruding arc sheet and its other end is slidably connected to the inner ring of the non-closed housing 51. In order to increase the connection strength between the test device and the object to be tested, the steel bar connection joint test device also includes a reinforcement component 6, which includes an electric rope retractor 61, a fixing rope 62 and a fixing plate 63. The electric rope take-up device 61 is arranged on one side of the connecting rod 2, the fixing plate 63 is connected to the connecting rod 2, a limiting hole 631 is arranged on the fixing plate 63, one end of the fixing rope 62 is connected to the electric rope take-up device 61, and the other end of the fixing rope 62 is detachably connected to the limiting hole 631. When in use, the fixing rope 62 is made to bypass the object to be measured and connected to the limiting hole 631, and then the electric rope take-up device 61 is started to increase the connection between the abutment ring 5 and the object to be measured.

[0067] The present invention utilizes the conductivity value of the steel bar connection joint to characterize the quality of the steel bar connection joint, that is, the conductivity value of the steel bar connection joint is compared with the conductivity value of a steel bar of equal length to obtain a conductivity ratio, and then the value of the conductivity ratio falls within a range to directly draw a conclusion on whether the quality of the steel bar connection joint meets the standard.

[0068] In order to prove the validity of the above numerical range, several experimental tests were carried out. The test process and results are as follows:

[0069] Test 1: Use the conductivity ratio to determine the effectiveness of the contact between the two steel wire heads in the sleeve.

[0070] Test steps: Three groups of steel bars and sleeve combinations from three batches AC were selected to form test groups 1-3. The distances between the two steel wire heads in the sleeves in the same test group were adjusted in turn and the conductivity ratio test was carried out. The test results are shown in Table 1.

[0071] Table 1 Test table for the effectiveness of conductivity ratio in judging the degree of abutment

[0072]

[0073] As can be seen from the table above, when the distance between the two steel wire heads in the sleeve is greater than 10mm, the conductivity ratio is between 0.03-0.05, and the value of the conductivity ratio does not change significantly with the steel bar spacing; when the distance between the two steel bars in the sleeve is 10mm-5mm, the conductivity ratio is between 0.15-0.41; when the distance between the two steel bars in the sleeve is 0, the conductivity ratio is between 1.29-1.46, and the conductivity ratio of the steel bars in the same batch does not change significantly. Therefore, the degree of abutment of the steel bars in the sleeve can be effectively evaluated according to the size of the conductivity ratio.

[0074] Test 2: Test the effectiveness of using conductivity ratio to determine the machining accuracy of steel wire heads.

[0075] The processing accuracy requires that the through gauge of the steel bar should be able to be screwed in smoothly and reach the required screw-in length, the screw-in of the stop gauge cannot exceed 3p, and the number of self-inspections of each specification should not be less than 10%, and the inspection pass rate should not be less than 95%.

[0076] The present invention selects samples with negative deviation in thread head processing and samples with processing accuracy that meet the requirements to conduct conductivity ratio test and pull-out test, and further subdivides the connection conditions of samples with negative deviation in thread head processing, specifically dividing them into two conditions: two steel bars are completely tightened against each other and two steel bars are partially tightened against each other due to lack of grinding. The test results are shown in Table 2.

[0077] Table 2 Test table of the effectiveness of conductivity ratio in judging wire head processing accuracy

[0078]

[0079] Among them, Class A and Class B are samples with negative deviations in thread head processing, Class C is a sample with thread head processing accuracy that meets the requirements, A-1 and A-2 are two steel bars that are completely against each other and tightened, and A-3 is two steel bars that are not ground flat, resulting in partial offset.

[0080] As can be seen from the above table, when there is a negative deviation in the processing of the steel wire head, its conductivity ratio is less than 1. Although it is greater than 0.8 or close to 1.0, it is still very different from the conductivity ratio of 1.3 that meets the processing accuracy requirements. In the tensile strength test and residual deformation test, although only the residual deformation of the A-2 sample is unqualified and the tensile strength of A-3 is unqualified, the sample failure form is that the steel bar is pulled out of the sleeve, indicating that the joints have not fully exerted the strength of the steel bar. The test results are consistent with the conclusion that when the conductivity ratio is less than 1.3 and greater than 0.9, it means that the steel wire head is abutted in the sleeve, but there are problems with the tensile strength and residual deformation of the steel bar. Therefore, the processing accuracy of the steel wire head can be judged and tested according to the size of the conductivity ratio, and on-site construction tests can be realized, which is conducive to guiding the site to improve the processing accuracy in time and improve the quality of the project. At the same time, the on-site conductivity ratio data tested is collected and counted to realize the calculation of the inspection pass rate in the entire project, making the detection more timely and comprehensive.

[0081] Test three: Use the conductivity ratio to comprehensively judge the effectiveness of the steel bar connection quality.

[0082] Select at least 2 groups of steel bars and sleeves from different batches of steel bars, connect the steel bars and sleeves according to the conventional installation steps, and then carry out conductivity ratio test and connection quality test respectively. Among them, the connection quality test includes four evaluation methods: the manufacturing accuracy of steel wire head, the tightening degree of steel bar connection joint, the uniaxial tensile ultimate tensile strength of steel bar connection joint and the residual deformation of steel bar. The indicators of the four evaluation methods are judged according to the national standards. When one of the four evaluation methods is unqualified, the comprehensive evaluation of the steel bar connection quality is unqualified.

[0083] Among them, the method for making the steel wire head with high precision is to extract the made steel bars for through gauge and no-gauge testing;

[0084] The tightening degree test of the steel bar connection joints is to sample the installed site and then use a torque wrench to tighten the torque test;

[0085] The uniaxial tensile ultimate tensile strength test and residual deformation of steel bars of steel bar connection joints are to cut steel bar connection joint specimens containing joints and a certain length of steel bars in the engineering structure, and then do uniaxial tensile ultimate compressive strength tests in the laboratory and check the residual deformation of the steel bars after the test.

[0086] The test results are shown in Table 3.

[0087] Table 3 Conductivity ratio comprehensive judgment of steel bar connection quality effectiveness test table

[0088]

[0089] It can be seen from the table above that when the conductivity ratio of the steel bar connection joint reaches 1.3 or above, the processing accuracy of the steel bar wire head meets the requirements, the steel bar wire head offsets each other in the sleeve, and the tensile strength and residual deformation meet the requirements. Therefore, when the conductivity ratio is greater than 1.3, it can be judged that the quality of the connection between the steel bar and the sleeve meets the standard.

[0090] When the two ends of the steel wire head are not butted against the steel bar, the conductivity ratio of the joint is less than 0.9, but the tensile strength and residual deformation are mostly qualified, which shows that the conductivity ratio can accurately evaluate whether the steel wire head is butted against each other in the sleeve. Therefore, when the conductivity ratio is less than 0.9, it is possible to first check whether the steel bar and the sleeve are butted, and then repeat the test.

[0091] When the machining accuracy of the steel wire head is insufficient, the joint conductivity ratio is between 0.8-1.29. At this time, most of the tensile strength is qualified, and some of the residual deformation is qualified. Therefore, when the conductivity ratio is between 0.8-1.29, it means that the connection between the steel wire head and the sleeve meets the standard, but there are problems with tensile strength and residual deformation, and replacement and adjustment are required.

[0092] It should be understood that the embodiments disclosed in the present invention are not limited to the specific processing steps or materials disclosed herein, but should be extended to equivalent substitutions of such features understood by ordinary technicians in the relevant field. It should also be understood that the terms used herein are only used for the purpose of describing specific embodiments and are not meant to be limiting.

Claims

1. A method for detecting the quality of a steel bar connection joint, used to detect whether the quality of a steel bar connection joint meets the standard; wherein: The steel bar connection joint comprises a sleeve and two steel bar wire heads respectively screwed into the sleeve from both ends, and is characterized in that the detection method comprises the following steps: S1: using a steel bar connection joint testing device to input electrical parameters into the steel bar connection joint and record the values ​​of the electrical parameters; S2: Collecting electrical parameter values ​​and detecting electrical response signals of the steel bar connection joints. At this time, the current value and voltage value of the steel bar connection joints are obtained through the electrical parameter values ​​and the electrical response signals. The current value and voltage value are input into the detection system to calculate the conductivity value, and finally the conductivity value Gx of the steel bar connection joint is obtained. The conductivity value calculation formula is: Gx=I / U, where I is the current in the steel bar joint and U is the voltage at the steel bar joint. S3: using the detection system to collect the conductivity value Gx of the steel bar connection joint and calculate and determine the conductivity ratio Gs; wherein the calculation formula of the conductivity ratio Gs is: Gs=Gx / G1, G1 is the conductivity value of the steel bar raw material of the same length as the steel bar connection joint; S3.1: When the conductivity ratio is ≥1.3, it means that the quality of the steel bar connection joint meets the standard; S3.2: When 0.9<conductivity ratio<1.3, it means that at least one of the following three situations exists: insufficient processing precision of steel wire head, unqualified tensile strength of steel bar and unqualified residual deformation, and the quality of steel bar connection joint does not meet the standard; S3.3: When the conductivity ratio is ≤0.9, it means that the steel wire head in the sleeve is not in contact or the quality of the steel bar connection joint does not meet the standard, and it is necessary to tighten the operation and repeat the test for further verification; if the conductivity ratio is still not higher than 0.9 after repeated testing, it means that there is at least one of the following three situations: insufficient processing accuracy of the steel wire head, unqualified tensile strength of the steel bar, and unqualified residual deformation, and the quality of the steel bar connection joint does not meet the standard; Among them, the electrical parameter is current, the electrical response signal is voltage, and the steel bar connection joint test device includes a connecting rod, two input rods, and two detection rods; the two detection rods are arranged between the two input rods and the input rod and the detection rod are vertically connected to the connecting rod; the input rod is connected to an external power supply through a circuit, and the detection rod is connected to an external voltage testing device through a circuit. The detection rod and the input rod are provided with an abutment ring at one end away from the connecting rod, and the abutment ring is used to connect the circuit and the object to be tested, and pressure is applied to the abutment ring so that the object to be tested and the test device form a closed test loop; the abutment ring includes a non-closed shell, an active switch and a conductive component, the non-closed shell is connected to the detection rod or the input rod and has a groove at the connection for the active switch to be embedded, and the two conductive components The first contact plate is disposed on the upper and lower sides of the groove respectively, and a reset spring is disposed on the upper and lower sides of the movable switch and the side close to the groove; the conductive component comprises a second contact plate, a converter and a spring sheet, the second contact plate is disposed in the groove and corresponds to the position of the first contact plate, the converter is connected to the second contact plate and processes the current received by the second contact plate, one end of the spring sheet is connected to the converter, and the other end of the spring sheet passes through the inner ring wall of the non-closed housing, the first contact plate is connected to the external circuit, and the abutment ring is pressed to make the first contact plate contact with the second contact plate and transmit electrical parameters or electrical response signals between the two; the spring sheet is an arc-shaped sheet protruding upward and the other end of the spring sheet is slidably connected to the inner ring of the non-closed housing; The detection system is also provided with a statistical module, which collects the conductivity ratios of the steel bar connection joints at different connections, establishes a steel bar connection model and marks the sleeve conductivity ratios at different connections on the model.

2. The method for detecting the quality of a steel bar connection joint according to claim 1, characterized in that: Before testing the steel bar connection joints, the conductivity value of the steel bars in the same batch needs to be tested; select steel bars of the same length as the steel bar joints as the test objects, and then repeat steps S1 and S2 to test the steel bars 3-5 times, take the average value of the test to obtain the conductivity value of the steel bar raw material and input it into the detection system for calculation.

3. The method for detecting the quality of a steel bar connection joint according to claim 1, characterized in that: The steel bar connection joint testing device also includes a reinforcement component, which includes an electric rope collecter, a fixed rope and a fixed plate. The electric rope collecter is arranged on one side of the connecting rod, and the fixed plate is connected to the connecting rod. A limiting hole is provided on the fixed plate. One end of the fixed rope is connected to the electric rope collecter, and the other end of the fixed rope is detachably connected to the limiting hole. When in use, the fixed rope is made to bypass the object to be tested and connected to the limiting hole, and then the electric rope collecter is started to increase the connection between the abutment ring and the object to be tested.

4. The method for detecting the quality of a steel bar connection joint according to claim 2, characterized in that: The detection system is provided with an information storage module. After receiving the conductivity value of the steel bar raw material, the information storage module stores the conductivity value. At this time, the project name and steel bar diameter of the steel bar raw material are input and a mapping relationship is formed between them and the conductivity value. For subsequent repeated testing of the steel bar connection joints at different connection points, only the corresponding project name and steel bar diameter need to be input to obtain the corresponding conductivity value of the steel bar raw material.

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