Cement-based material electrical property convenient detection tool and rapid detection method

Abstract

The invention discloses a cement-based material electrical property convenient detection tool and a rapid monitoring method.The cement-based material electrical property convenient detection tool is mainly composed of a tubular embedded part with a conductive point, a tubular sensor assembly with a spring contact and a magnetic attraction mechanism, a vertical groove is formed in the inner wall of a pipe of the embedded part, a vertical protrusion is arranged on the outer wall of a pipe of the sensor assembly, and the magnetic attraction mechanism is arranged in the vertical groove; when the sensor assembly extends into the embedded part along the groove through the protrusion, the conductive contact and the spring contact are just in close contact through the magnetic attraction mechanism. The method only needs to operate on a computer in the data collection stage, only needs to replace the sensor assembly in the maintenance stage, and is convenient to operate, simple and easy to learn. And the whole device is mainly made of resin, so that the cost is lower, and the device has a great advantage in cost compared with a detection device in the market at present.

Description

Technical Field

[0001] The present invention relates to the technical field of detecting the electrical properties of cement-based materials, and specifically to a buried-type technology for detecting the electrical properties of cement-based materials. Background Art

[0002] The conductivity of cement-based materials is of great significance. With the in-depth research on cement-based materials in recent years, it has been possible to obtain the conductivity index of cement-based materials through relatively simple methods, and the conductivity of cement-based materials has gradually been taken seriously in theoretical research and practical applications. The measurement of the conductivity of cement-based materials is simple, fast, and convenient, and has been used as a new non-destructive testing technology for cement-based materials in engineering surveys.

[0003] Currently, the main methods for measuring the electrical properties of cement-based materials are the contact method and the non-contact method. The conductivity data measured by the non-contact method has poor stability and can only be applied to small-volume cement-based material samples in the laboratory, making it difficult to be used in actual engineering detections; the contact method has good stability in measuring conductivity data and is the main direction of current research on the conductivity of cement-based materials.

[0004] The contact method mainly includes the two-electrode method and the four-electrode method. The four-electrode method has high detection accuracy, but due to the use of an equivalent circuit, the data is complex, the timeliness is low, and the detection device cannot be made low-cost and miniaturized, resulting in the difficulty of large-scale application of the four-electrode method in engineering detections; the two-electrode method has relatively high detection accuracy, simple data, good timeliness, and the detection device is small, flexible, and low-cost, and can be widely applied, which is favored by researchers.

[0005] Nowadays, the buried-type technology of the contact method shows the possibility of expanding the application scenario in international research. The buried-type technology of the contact method is expected to demonstrate its potential in actual engineering applications, such as the buried-type durability non-destructive testing system for trapezoidal anode concrete structures invented by the Institute of Civil Engineering of RWTH Aachen University in Germany, the ring-shaped sensor in Denmark, and the ECI-2 durability monitoring sensor in the United States. However, the existing sensors may have the fatal defect of short service life and inability to be replaced and maintained, and even the situation where the buried detection instruments are damaged before the project is completed, and the detection procedure is complex.

[0006] Therefore, it is necessary to develop a new tool for detecting the conductivity of cement-based materials to solve the applicable problems in actual engineering. Summary of the Invention

[0007] Aiming at the industry pain points of short service life, difficult maintenance, and high cost of the detection device and the technical defect of complex detection method in the method for detecting the electrical properties of cement-based materials, the present invention provides a convenient buried-type tool for detecting the electrical properties of cement-based materials.

[0008] The present invention also provides a method for quickly detecting the electrical properties of cement-based materials using such a detection tool.

[0009] To achieve the above object, the technical solution adopted by the present invention is:

[0010] A convenient detection tool for the electrical properties of cement-based materials, characterized in that it mainly consists of a tubular embedded part with conductive points, a tubular sensor assembly with spring contacts, and a magnetic attraction mechanism. A vertical groove is provided along the inner wall of the tube of the embedded part, and a vertical protrusion is provided along the outer wall of the tube of the sensor assembly. When the sensor assembly extends into the embedded part along the protrusion along the groove, the conductive contact and the spring contact just come into close contact through the magnetic attraction mechanism.

[0011] Further: The embedded part includes a housing with a closed bottom and an open top. A pair of stainless steel contacts are provided on the housing of the embedded part, and the stainless steel contacts penetrate through the housing of the embedded part.

[0012] Further, the sensor assembly includes a housing with a shape that matches the shape of the housing of the embedded part and open ends at both ends. A pair of spring contacts are provided on the housing of the sensor assembly, and the spring contacts penetrate through the sensor assembly. During use, the spring contacts are connected to the analog-to-digital conversion module through wires.

[0013] Further, the magnetic attraction mechanism includes two sets, which are respectively arranged on the outer wall of the sensor assembly and the inner wall of the embedded part by embedding. When the sensor assembly extends into the embedded part, the stainless steel contacts and the spring contacts come into close contact through the two sets of magnetic attraction mechanisms.

[0014] Further, the magnetic attraction mechanism is composed of a plurality of magnets, and the plurality of magnets are evenly arranged around the stainless steel contacts or the spring contacts. The magnetic attraction mechanism is preferably composed of three magnets, and the three magnets are arranged in an isosceles triangle to increase the anti-deformation ability of the magnetic attraction mechanism and promote the stable contact between the stainless steel contacts and the spring contacts.

[0015] Further, in order to make it easier for the conductive contacts and the spring contacts to come into contact after the sensor assembly extends into the embedded part, the housing of the embedded part and the housing of the embedded part are both cylindrical.

[0016] Further, the inner wall of the housing of the embedded part includes two vertically symmetric parallel planes, and the outer wall of the housing of the sensor assembly includes two vertically symmetric parallel planes. The two sets of magnetic attraction mechanisms are respectively embedded on their respective parallel planes. At the same time, the conductive contacts and the spring contacts are respectively perpendicular to one of their respective parallel planes. At this time, the groove of the embedded part and the protrusion of the sensor assembly are just on their respective other parallel planes, so as to ensure that when the sensor assembly extends into the embedded part along the protrusion along the groove, the conductive contacts and the spring contacts just come into close contact through the magnetic attraction mechanism.

[0017] Furthermore, in order to facilitate the rapid sequential detection of the electrochemical properties of cement-based materials at different depths, a plurality of conductive contacts and corresponding magnetic attraction mechanisms are provided at intervals along the height direction on the embedded part housing.

[0018] In order to detect the electrochemical properties of cement-based materials at different depths at one time, a plurality of spring contacts and corresponding magnetic attraction mechanisms are also provided on the sensor assembly, so that one set of spring contacts corresponds to one set of conductive contacts. In this way, when in use, each set of spring contacts can be electrically connected to a single-channel analog-to-digital conversion module, or all sets of spring contacts can be electrically connected to a multi-channel analog-to-digital conversion module.

[0019] A method for quickly detecting the electrical properties of cement-based materials by using the above-mentioned electrical property table convenient detection tool for cement-based materials includes the following steps:

[0020] S1. When making the concrete block, after fully stirring, pour the cement mortar into the mold. After pouring, vibrate and compact it. Precisely insert the embedded part to the designated position. After the cement mortar solidifies, the conductive contacts on the embedded part are tightly combined with the cement-based material.

[0021] S2. Align the protrusion of the sensor assembly with the groove of the embedded part, and then push the sensor assembly into the embedded part until the magnetic attraction structure is engaged. After confirming that the plane of the sensor assembly is tightly attached to the plane of the embedded part and there is no sign of sagging or loosening, at this time, the sensor assembly is fixed to the embedded part, and the spring contacts of the sensor assembly are tightly combined with the conductive contacts of the embedded part.

[0022] S3. The spring contacts of the sensor assembly are connected to the analog-to-digital conversion module through wires. The analog-to-digital conversion module converts the electrical response analog signal of the cement-based material transmitted by the contacts into a communication signal, and the communication signal is then transmitted to a computer with data processing function, and the computer calculates the conductivity of the cement-based material.

[0023] Compared with the prior art, the positive effects of the present invention are:

[0024] 1. Through the embedded scheme, while retaining the accuracy and stability of detecting the conductivity of cement-based materials by the contact method, the present invention expands the application scenario to the actual engineering application.

[0025] 2. Through the magnetic attraction and contact detection structure, the purpose of replacing the sensor assembly is realized, which greatly prolongs the service life of the embedded structure and reduces the cost at the same time. The service life of the detection tool is made equivalent to the engineering design life, and the detection and maintenance cost of the project is reduced.

[0026] 3. The real-time monitoring of the electrical conductivity of cement-based materials has been realized in actual engineering. For actual projects using cement-based materials, in order to achieve the maximum time and economic effects, the measurement method should be as simple as possible, acceptable to general technicians of construction units, and the volume and cost of the detection device at each measurement point. In the data collection stage of the present invention, only operations on a computer are required. In the maintenance stage, only the sensor assembly needs to be replaced, with convenient operation and easy to learn. Moreover, the overall device is mainly made of resin, with low cost, and has a great advantage in cost compared with the detection devices on the current market. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for the description of the embodiments will be briefly introduced below. The drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0028] Figure 1 It is a three-dimensional view of an embedded cement-based material electrical property detection tool of the present invention.

[0029] Figure 2 For the present invention Figure 1 Internal structure diagram of the embedded part 3 therein.

[0030] Figure 3 It is a sectional view of the installation and setting of the embedded part after the construction of the bridge tower of the hollow bridge is completed according to the present invention.

[0031] In the figure: 1 - embedded part, 2 - sensor assembly, 3 - stainless steel detection contact, 4 - spring contact, 5 - embedded part magnetic attraction mechanism, 6 - sensor assembly magnetic attraction mechanism. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0032] The technical solutions in the embodiments of the present invention will be clearly, completely and detailedly described below in conjunction with the drawings in the specific engineering implementation of the present invention. However, it should be noted that the described embodiments are only some embodiments of the present invention, rather than all embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts belong to the scope of protection of the present invention.

[0033] As Figure 1 and Figure 2 shown, the detection tool of the present invention as a whole includes an embedded part 1, a sensor assembly 2 and a magnetic attraction mechanism, wherein;

[0034] The embedded part 1 mentioned above is a cylinder with a closed bottom and an open top. There are two vertically symmetric parallel planes on the inner wall of the cylinder. A pair of small holes parallel to the horizontal direction are provided at the bottom of the cylinder. Stainless steel contacts 3 are installed in the small holes. One end (i.e., the top end) of the stainless steel contact 3 is exposed to contact with the cement-based material, and the other end (i.e., the bottom end) penetrates the wall thickness of the embedded part 1 and is perpendicular to one of the parallel planes of the cylinder. A groove (not shown in the figure) is provided on the other parallel plane of the inner wall of the embedded part 1.

[0035] The sensor assembly 2 mentioned above is also a cylinder with both ends open. There are also two vertically symmetric parallel planes on the surface of the sensor cylinder. A pair of circular small holes parallel to the horizontal direction are provided on one parallel plane. Spring contacts 4 are installed in the small holes. The bottom end of the spring contact 4 extends into the inner cavity of the sensor cylinder, and the top end of the spring contact 4 penetrates the wall thickness of the sensor cylinder and is perpendicular to one of the parallel planes of the sensor cylinder. A protrusion (not shown in the figure) is provided on the other parallel plane of the outer wall of the sensor assembly 2. During use, the spring contact 4 is electrically connected to the analog-to-digital conversion module (preferably an ads1115 chip) through a wire. At this time, the analog-to-digital conversion module can be arranged in the inner cavity of the sensor assembly 2 or can be independent of the sensor assembly 2 and arranged outside the sensor assembly 2.

[0036] There are two sets of magnetic attraction mechanisms, which are respectively called the embedded part magnetic attraction mechanism 5 and the sensor assembly magnetic attraction mechanism 6, and are respectively embedded in the inner wall of the embedded part 1 and the outer wall of the sensor assembly 2. It can be seen from the figure that the magnetic attraction mechanism is composed of three magnets, which are arranged in an isosceles triangle around the stainless steel contact 3 or the spring contact 4. When the sensor assembly 2 extends into the embedded part 1 along the groove through the protrusion, the stainless steel contact 3 and the spring contact 4 can be in close contact through the embedded part magnetic attraction mechanism 5 and the sensor assembly magnetic attraction mechanism 6.

[0037] In order to test the conductivity of the cement-based material at different depths, multiple groups of stainless steel contacts are provided at vertical intervals on the embedded part.

[0038] In the embodiment, the length of the cylinder of the embedded part 1 is 100 - 110 mm, the inner wall radius is 15 - 18 mm, and the arc angle is 250° - 300°; the wall thickness of the curved surface part is 2 - 3 mm, the wall thickness of the plane part is 3 - 4 mm, and the wall thickness of the bottom is 2 - 3 mm; the center distance between the two small holes for installing the stainless steel contacts is 11 - 14 mm, the opening radius is 1 - 1.5 mm, and the center of the hole is 14 - 17 mm away from the bottom of the embedded part. The radius of the circular groove for installing the three magnets on the embedded part magnetic attraction mechanism 5 is 2.5 - 3.5 mm, the depth is 1.5 - 2.5 mm, and the 3 circular grooves are distributed in an isosceles triangle and are symmetric in the vertical direction. The center distance between the two lower grooves is 9 - 11 mm, the center of the groove is 7 - 9 mm away from the bottom surface of the embedded part, and the distance from the center of the upper groove to the bottom of the embedded part is 21 - 24 mm. The distance between the circular opening and the circular groove is not less than 2 mm.

[0039] In the embodiment, the cylindrical body of the sensor assembly 2 is 40-90 mm long, with an outer wall radius of 14-17 mm (the outer wall radius of the sensor assembly housing = the inner wall radius of the embedded part - 1), and an arc angle of 250°-300°; the wall thickness of the curved portion is 2-3 mm, and the wall thickness of the flat portion is 3-4 mm. The distance between the centers of the two circular openings for mounting the spring contacts is 11-14 mm, the opening radius is 1-1.5 mm, and the distance between the center of the opening and the bottom of the sensor assembly housing is equal to the distance between the center of the embedded part and the bottom of the embedded part - 3. The circular grooves for mounting the three magnets of the sensor assembly magnetic attraction mechanism 6 have a radius of 2.5-3.5 mm and a depth of 1.5-2.5 mm. They are distributed in the same manner as the circular grooves on the inner plane of the embedded part and are symmetrical in the vertical direction. The distance between the center of the groove and the bottom of the sensor assembly housing is equal to the distance between the center of the groove and the bottom of the embedded part - 3. The distance between the circular opening and the circular groove is not less than 2 mm, and the distance from the bottom of the sensor assembly housing is not less than 2 mm.

[0040] In order to reduce costs, the sensor assembly 2 and the embedded component 1 in the embodiment are both made of resin material.

[0041] The detection method of the present invention is described below by way of examples.

[0042] Example 1

[0043] Cement mortar was prepared and thoroughly mixed before pouring into the mold. After pouring, the mortar was compacted using a vibrating table. The embedded component was precisely inserted into the designated position. The embedded component was a vertically cut hollow cylinder with a closed bottom and an open top, made of resin. The cylinder was 102.5 mm long, with an inner wall radius of 16.5 mm and an arc angle of 274.03°. The wall thickness of the curved surface was 2 mm, the flat surface was 4 mm, and the bottom wall was 2.5 mm. The specimen was left to stand for 24 hours until the mortar solidified, then demolded. After curing for 28 days, the conductivity of the specimen was measured using a sensor assembly. The sensor assembly housing was similar to the embedded component, made of resin. The cylinder was 60 mm long, with an outer wall radius of 15.5 mm (sensor assembly housing outer wall radius = embedded component inner wall radius - 1), an arc angle of 212.17°, and a wall thickness of 3 mm on the curved surface and 3.39 mm on the flat surface.

[0044] Example 2

[0045] When building a new bridge, before the main concrete-based material project such as bridge piers is poured and shaped, an embedded component with multiple groups of stainless steel contacts is installed near the steel bars inside the steel cage. The electrical properties of the main body of the concrete-based material project at different depths are detected one by one using the sensor component. During measurement, the electrical properties of the deepest part of the main body of the concrete-based material project are measured first, then the sensor component is withdrawn, and the electrical properties of the second deepest part are measured, and so on, until the full coverage of the electrical property measurement of the entire main body of the concrete-based material project is achieved. In practice, the sensor component 2 can also be correspondingly provided with multiple groups of spring contacts and magnetic attraction mechanisms (the same number as the groups of stainless steel contacts). Each group of spring contacts is electrically connected to a data conversion module, or all groups of spring contacts are electrically connected to a multi-channel data conversion module. In this way, when the sensor component extends into the embedded component, each group of contacts measures the electrical properties of the main body of the concrete-based material project at one depth, and the full coverage of the electrical property measurement of the entire main body of the concrete-based material project can also be achieved. This is not difficult to implement in this field. Of course, this is not the focus of the protection of the present invention, so it will not be elaborated further here.

[0046] Embodiment III

[0047] In the case of a bridge using a hollow bridge tower where it is impossible to build an entire embedded pipe, during the construction of the hollow bridge tower, at equally spaced positions inside the bridge tower, the embedded part 1 is buried from the tower to the outside for detection (see Figure 3 ).

[0048] Of course, the above description is not a limitation of the present invention, and the present invention is not limited to the above examples. Changes, modifications, additions, or substitutions made by those skilled in the art within the scope of the essence of the present invention should also fall within the protection scope of the present invention.

Claims

1. A convenient detection tool for the electrical properties of cement-based materials, characterized in that, It mainly consists of three parts: a tubular embedded part with conductive points, a tubular sensor assembly with spring contacts, and a magnetic attraction mechanism. A vertical groove is provided along the inner wall of the tube of the embedded part, and a vertical protrusion is provided along the outer wall of the tube of the sensor assembly. When the sensor assembly extends into the embedded part through the protrusion along the groove, the conductive contact and the spring contact just come into close contact through the magnetic attraction mechanism.

2. The convenient detection tool for the electrical properties of the cement-based material according to claim 1, characterized in that, The embedded part includes a housing with a closed bottom and an open top. A pair of stainless-steel contacts are provided on the housing of the embedded part, and the stainless-steel contacts penetrate through the housing of the embedded part.

3. The convenient detection tool for the electrical properties of the cement-based material according to claim 2, characterized in that, The sensor assembly includes a housing with a shape that matches the shape of the housing of the embedded part and open ends at both ends. A pair of spring contacts are provided on the housing of the sensor assembly, and the spring contacts penetrate through the sensor assembly.

4. The convenient detection tool for the electrical properties of the cement-based material according to claim 3, wherein The magnetic attraction mechanism includes two sets, which are respectively arranged on the outer wall of the sensor assembly and the inner wall of the embedded part by an embedding method.

5. The convenient detection tool for the electrical properties of the cement-based material according to claim 4, wherein The magnetic attraction mechanism consists of multiple magnets, and the multiple magnets are evenly arranged around the stainless-steel contact or the spring contact; preferably, the magnetic attraction mechanism consists of three magnets, and the three magnets are arranged in an isosceles triangle.

6. The convenient detection tool for the electrical properties of the cement-based material according to claim 1, characterized in that The conductive contact and the spring contact are more likely to come into contact. The housing of the embedded part and the housing of the embedded part are both cylindrical.

7. The convenient detection tool for the electrical properties of the cement-based material according to claim 1, characterized in that, The inner wall of the housing of the embedded part includes two vertically symmetric parallel planes, and the outer wall of the housing of the sensor assembly includes two vertically symmetric parallel planes. The two sets of magnetic attraction mechanisms are respectively embedded on their respective parallel planes. At the same time, the conductive contact and the spring contact are respectively perpendicular to one of their respective parallel planes. At this time, the groove of the embedded part and the protrusion of the sensor assembly are just on their respective other parallel planes.

8. The convenient detection tool for the electrical properties of the cement-based material according to claim 1, wherein, Multiple sets of stainless-steel contacts and corresponding magnetic attraction mechanisms are provided on the housing of the embedded part at intervals in the height direction.

9. The convenient detection tool for the electrical properties of the cement-based material as described in claim 8, wherein, Multiple sets of spring contacts and corresponding magnetic attraction mechanisms are also provided on the sensor assembly, so that a set of spring contacts pairs with a set of stainless-steel contacts.

10. A method for rapidly detecting the electrical properties of a cement-based material by using the convenient detection tool for the electrical properties of the cement-based material described in any one of claims 1-9, characterized in that, It includes the following steps: S1. When making the concrete block, after sufficient stirring, pour the cement mortar into the mold. After pouring, vibrate and compact it. Precisely insert the embedded part to the designated position. After the cement mortar solidifies, the conductive contacts on the embedded part are tightly combined with the cement-based material. S2. Align the protrusion of the sensor assembly with the groove of the embedded part, and then push the sensor assembly into the embedded part until the magnetic attraction structure is attracted. After confirming that the plane of the sensor assembly is tightly attached to the plane of the embedded part and there is no sign of sagging or loosening, at this time, the sensor assembly and the embedded part are fixed together, and the spring contacts of the sensor assembly are tightly combined with the conductive contacts of the embedded part. S3. The spring contacts of the sensor assembly are connected to the analog-to-digital conversion module through wires. The analog-to-digital conversion module converts the electrical response analog signal of the cement-based material transmitted by the contacts into a communication signal, and the communication signal is then transmitted to a computer with data processing function, and the computer calculates the conductivity of the cement-based material.

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