Concrete freezing and thawing cycle testing machine and use method thereof

Abstract

The invention discloses a concrete freezing and thawing cycle testing machine and a using method thereof. The problem of manual water changing is solved. The quality problem that the test piece needs to be carried and manually weighed is solved; the mass loss of the test piece is continuously monitored; according to the technical scheme, the testing machine comprises a control panel, a testing machine main body and a dynamic elastic modulus tester, the cover plate is arranged above the testing machine main body, a plurality of testing cabins are arranged in the testing machine main body, and a partition plate is arranged between every two adjacent testing cabins; a lofting window is formed in the upper part of the test cabin; a test piece frame is arranged in the test cabin, a pressure sensor is arranged at the end part of the test piece frame, the test piece frame is in contact with the partition plate through the pressure sensor, and a temperature control device is also arranged in the partition plate; a dynamic elastic modulus tester is mounted in the test piece frame; the dynamic elastic modulus tester, the temperature control device and the pressure sensor are all connected with the control panel; a water inlet and a water outlet are formed in the test cabin wall.

Description

Technical Field

[0001] The invention belongs to the technical field of concrete index detection, and particularly relates to a concrete freeze-thaw cycle testing machine and a use method thereof. Background Art

[0002] The statements in this section merely provide background information related to the present invention and do not necessarily constitute prior art.

[0003] As a common building material, concrete has good compressive strength and durability and is often used in building and road construction. However, in seasonally frozen areas, the alternating positive and negative temperature changes can cause freeze-thaw damage to concrete, leading to volume expansion, crack formation, and strength loss, which in turn affects the stability and service life of the structure. In order to study the performance changes of concrete under freeze-thaw cycle conditions, freeze-thaw cycle tests are often performed to observe the changes and evaluate the durability of concrete.

[0004] At present, freeze-thaw cycle tests for concrete are often conducted using freeze-thaw cycle machines and are tested according to the methods provided in the Standard for Test Methods for Long-term Performance and Durability of Ordinary Concrete. However, in the traditional test process, a large number of specimen handling processes occur, requiring manual removal of specimens from the specimen box, wiping of moisture on the surface of the specimens, and weighing of the mass loss of the specimens. In addition, the medium solution in the specimen box needs to be replaced manually after each freeze-thaw cycle, which is time-consuming and labor-intensive. The specimens may also be damaged during the handling process, affecting the test results. In addition, when the dynamic elastic modulus is used as an indicator to evaluate specimen damage, additional instruments are required to measure the dynamic elastic modulus of the specimens. Summary of the invention

[0005] In view of the above problems, the present invention provides a concrete freeze-thaw cycle testing machine and a method for using the same. Automatic water change is achieved by connecting the water inlet and outlet, thus solving the problem of manual water change. The built-in pressure sensor and the built-in retractable dynamic elastic modulus tester solve the problems of needing to transport test pieces and manually weigh the test piece mass. The test piece rack is of hollow design, and by connecting the pressure sensor and the control panel, uninterrupted observation of the test piece mass loss can be achieved.

[0006] In order to achieve the above object, the present invention is implemented through the following technical solutions:

[0007] In a first aspect, the present invention provides a concrete freeze-thaw cycle testing machine, including a control panel, a cover plate, a testing machine body, and a dynamic elastic modulus tester;

[0008] The cover is arranged above the testing machine body, and a plurality of test chambers are arranged inside the testing machine body, with partitions arranged between adjacent test chambers; a sample placement window is opened above the test chamber; a specimen rack is arranged in the test chamber, a pressure sensor is arranged at the end of the specimen rack, the specimen rack contacts the partition through the pressure sensor, and a temperature control device is also arranged in the partition; a dynamic elastic modulus tester is installed in the specimen rack; the dynamic elastic modulus tester, the temperature control device and the pressure sensor are all connected to the control panel; a water outlet is arranged below the test chamber, and a water inlet is arranged on the side of the test chamber.

[0009] Furthermore, at least two rows of test chambers are arranged in the main body of the test machine, and each row is arranged with at least four test chambers.

[0010] Furthermore, the specimen rack is a support structure formed by a plurality of U-shaped metal wires arranged vertically and horizontally; both ends of the metal wires are fixedly connected to one side of the upper portion of the pressure sensor, and the metal wires are wrapped with rubber.

[0011] Furthermore, the lower portion of the pressure sensor is fixedly connected to the edge of the lofting window on the top of the test chamber.

[0012] Furthermore, the edge of the lofting window is provided with a mounting hole for the dynamic elastic modulus tester, and the mounting hole is arranged in a vertical direction.

[0013] Furthermore, the dynamic elastic modulus tester is composed of a transmitter, a receiver, a mounting bracket and a folding rod; the mounting bracket is a U-shaped structure, the transmitter and the receiver are installed at one end of the opening of the mounting bracket, and the transmitter and the receiver are arranged relative to each other; the end of the mounting bracket away from the opening is connected to one end of the folding rod, and the mounting bracket and the folding rod are hingedly connected.

[0014] Furthermore, the other end of the folding rod is inserted into the mounting hole.

[0015] Furthermore, the water inlet and the water outlet are respectively provided with electromagnetic valves, and the electromagnetic valves are connected to the control panel.

[0016] Furthermore, the control panel is arranged on one side of the testing machine, and the control panel is provided with a touch screen for displaying test data and for controlling the electromagnetic valve and the temperature control device;

[0017] The testing machine body and the cover plate are hinged to facilitate opening and closing of the cover plate.

[0018] In a second aspect, the present invention further provides a method for using a concrete freeze-thaw cycle testing machine, comprising:

[0019] S1. Prepare concrete beam specimens according to the specification requirements, soak them in water at a set temperature for N days. The water level should be higher than the top surface of the specimens during soaking. After soaking, select the curing age according to different specimen types to cure the specimens. After curing, conduct subsequent tests;

[0020] S2. Take out the specimens that have reached the curing age, wipe off the surface moisture, measure the appearance dimensions, put them into the specimen rack of the testing machine according to the number, weigh the initial mass of each specimen, and obtain the data on the control panel;

[0021] S3. Operate the control panel, use the control panel to control the electromagnetic valve at the water inlet to open, inject water into the water inlet, the water level is higher than the top surface of the specimen, use the control panel to control the electromagnetic valve at the water inlet to close, and then perform freeze-thaw cycles in accordance with the specification requirements;

[0022] S4. After the freeze-thaw cycle, operate the control panel, use the control panel to control the electromagnetic valve at the water outlet to open, discharge water through the water outlet, observe the changes in the appearance of the specimen, and use the dynamic elastic modulus tester to test, until the water in the test chamber is completely discharged, the electromagnetic valve at the water outlet is closed;

[0023] S5. Retrieve various data from the control panel for analysis.

[0024] Compared with the prior art, the present invention has the following advantages and positive effects:

[0025] The present invention connects a pressure sensor to the end of a specimen rack and sets a dynamic elastic modulus tester. Both the pressure sensor and the dynamic elastic modulus tester are connected to a control panel via cables stored in the top space of a box body to obtain data changes before and after. The present invention abandons a specimen box and sets an independent sealed test chamber, which can simultaneously measure various test parameters under different medium solution conditions by injecting different medium solutions. The independent compartment realizes automatic water change by connecting a water inlet and a water outlet, thereby solving the problem of manual water change. The built-in pressure sensor solves the problem of needing to carry the specimen and manually weighing the specimen mass. The built-in storable dynamic elastic modulus tester solves the problem of needing additional instruments and manually carrying the specimen, thereby saving time and manpower and reducing test errors.

[0026] The specimen rack of the present invention is of hollow design. After each freeze-thaw cycle, the damaged and peeled fragments of the specimen will fall off to the bottom of the compartment. By connecting the pressure sensor and the control panel, uninterrupted observation of the mass loss of the specimen can be achieved. The metal wire of the specimen rack is wrapped with rubber to prevent the specimen from adhering to the wall of the test cabin during the test. The lower part of the pressure sensor is fixedly connected to the edge of the lofting window on the top of the test cabin, so that the mass change of the sample can be monitored in real time during the test, and at the same time, the problem of inaccurate quality monitoring caused by the adhesion of the specimen rack to the wall of the test cabin is prevented. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] The accompanying drawings in the specification, which constitute a part of the present invention, are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations on the present invention.

[0028] Figure 1 The overall structure diagram of the testing machine of the present invention;

[0029] Figure 2 It is a schematic diagram of the internal structure of the testing machine of the present invention;

[0030] Figure 3 It is a schematic diagram of the test piece rack and the partition structure of the present invention;

[0031] Figure 4 This is a schematic diagram of the installation of the test piece rack and the pressure sensor of the present invention;

[0032] Figure 5 This is a cross-sectional view of the internal structure of the test chamber of the present invention;

[0033] Figure 6 It is a schematic diagram of the dynamic elastic modulus tester of the present invention.

[0034] In the figure: 1. control panel; 2. cover plate; 3. testing machine body; 4. dynamic elastic modulus tester; 401. transmitter; 402. receiver; 403. folding rod; 5. specimen rack; 6. water inlet; 7. water outlet; 8. pressure sensor; 9. partition; 10. cable. DETAILED DESCRIPTION

[0035] It should be noted that the following detailed descriptions are illustrative and intended to provide further explanation of the present invention. Unless otherwise specified, all technical and scientific terms used in the present invention have the same meanings as those commonly understood by those skilled in the art to which the present invention belongs.

[0036] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present invention. As used herein, unless otherwise explicitly stated in the present invention, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "include" and / or "include" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof;

[0037] This embodiment discloses a concrete freeze-thaw cycle testing machine, such as Figure 1-Figure 6 As shown, it includes a control panel 1, a cover plate 2, a testing machine body 3, and a dynamic elastic modulus tester 4; the cover plate 2 is arranged above the testing machine body 3, and a plurality of test chambers are arranged inside the testing machine body 3, and a partition plate 9 is arranged between adjacent test chambers; in this embodiment, the test chambers are arranged in two rows, each row is provided with four test chambers, and a sample placement window is opened above the test chamber; a specimen rack 5 is arranged in the test chamber, a pressure sensor 8 is arranged at the end of the specimen rack 5, the specimen rack 5 is in contact with the partition plate 9 through the pressure sensor 8, and a temperature control device is also arranged in the partition plate 9; a dynamic elastic modulus tester 4 is installed in the specimen rack 5; the dynamic elastic modulus tester 4, the temperature control device and the pressure sensor 8 are all connected to the control panel 1; a water outlet 7 is arranged below the test chamber, and a water inlet 6 is arranged on the side of the test chamber. In this embodiment, the form of the specimen box in the traditional testing machine is changed, and an independently sealed test chamber is provided. Different medium solutions can be injected into the test chamber to realize the simultaneous measurement of various test parameters under different medium solution conditions; the test chamber realizes automatic water change by connecting the water inlet 6 and the water outlet 7, which solves the problem of manual water change; the built-in pressure sensor 8 solves the problem of needing to transport the specimen and manually weigh the specimen mass.

[0038] The specimen rack 5 provided in the test chamber is a support structure formed by a plurality of U-shaped metal wires arranged vertically and horizontally, both ends of the metal wires are fixedly connected to one side of the upper part of the pressure sensor 8, and the metal wires are wrapped with rubber to prevent the specimen from adhering to the wall of the test chamber during the test; the lower part of the pressure sensor 8 is fixedly connected to the edge of the lofting window at the top of the test chamber, so that the mass change of the sample can be monitored in real time during the test, and at the same time, the problem of inaccurate quality monitoring caused by the adhesion of the specimen rack 5 to the wall of the test chamber is prevented; the middle position of the top of the pressure sensor 8 is connected to one end of the cable 10, and the other end of the cable 10 is connected to the control panel 1; the built-in pressure sensor 8 solves the problem of needing to transport the specimen and manually weigh the specimen mass; since the specimen rack 5 is a hollow design, the damaged and peeled fragments of the specimen will fall to the bottom of the compartment after each freeze-thaw cycle, and the uninterrupted observation of the specimen mass loss is achieved by connecting the pressure sensor 8 and the control panel 1.

[0039] The edge of the lofting window is provided with a mounting hole for the dynamic elastic modulus tester, and the mounting hole is arranged in a vertical direction; the dynamic elastic modulus tester 4 is composed of a transmitter 401, a receiver 402, a mounting bracket and a folding rod 403; the mounting bracket is in a U-shaped structure, the transmitter 401 and the receiver 402 are mounted at one end of the opening of the mounting bracket, and the transmitter 401 and the receiver 402 are arranged oppositely; the end of the mounting bracket away from the opening is connected to one end of the folding rod 403, and the mounting bracket is connected to the folding rod 403. The rods 403 are hingedly connected; the other end of the folding rod 403 is inserted into the installation hole of the dynamic elastic modulus tester; when the sample needs to be placed in the specimen rack 5 or the sample needs to be taken out, the installation bracket needs to be lifted, and when the operation is completed, the installation bracket is lowered to avoid touching the elastic modulus tester during sampling or placement, causing damage to the elastic modulus tester; by having a built-in retractable dynamic elastic modulus tester 4, the problem of needing additional instruments and manual handling of specimens is solved, saving time and manpower, and reducing test errors.

[0040] The water inlet 6 and the water outlet 7 are respectively provided with electromagnetic valves, and the electromagnetic valves are connected to the control panel 1. When water injection or drainage is required, the opening and closing of the electromagnetic valves are controlled by the control panel 1.

[0041] The method of use includes the following steps:

[0042] S1. Prepare concrete beam specimens in accordance with the requirements of the specification, and soak them in water at a set temperature for N days. The water temperature and soaking time are selected according to actual needs. The water surface should be higher than the top surface of the specimen during soaking. After soaking, select the curing age according to different specimen types to cure the specimens. After curing, conduct subsequent tests; for example, the curing age of some specimens needs to reach 28 days before freeze-thaw tests are conducted; for freeze-thaw test specimens that are always cured in water, when the curing age of the specimens reaches 28 days, subsequent tests can be directly conducted;

[0043] S2. After reaching the curing age, remove the specimens, wipe off the surface moisture, measure the appearance dimensions, place them on the specimen rack 5 of the testing machine according to the number, weigh the initial mass of each specimen, and obtain the data in the control panel 1;

[0044] S3. Operate the control panel 1, use the control panel 1 to control the electromagnetic valve at the water inlet 6 to open, inject water into the water inlet 6, the water level is higher than the top surface of the specimen, use the control panel 1 to control the electromagnetic valve at the water inlet 6 to close, and then perform freeze-thaw cycles in accordance with the specification requirements;

[0045] S4. After the freeze-thaw cycle, operate the control panel 1, use the control panel 1 to control the electromagnetic valve at the water outlet 7 to open, discharge water through the water outlet 7, observe the changes in the appearance of the specimen, and use the dynamic elastic modulus tester 4 to test, until the water in the test chamber is completely discharged, the electromagnetic valve at the water outlet 7 is closed;

[0046] S5. Retrieve various data from the control panel 1 for analysis.

[0047] Although the above describes the specific implementation mode of the present invention in conjunction with the accompanying drawings, it is not intended to limit the scope of protection of the present invention. Those skilled in the art should understand that various modifications or variations that can be made by those skilled in the art on the basis of the technical solution of the present invention without creative work are still within the scope of protection of the present invention.

Claims

1. A concrete freeze-thaw cycle testing machine, characterized in that: Including control panel, cover plate, testing machine body, dynamic elastic modulus tester; The cover is arranged above the testing machine body, and a plurality of test chambers are arranged inside the testing machine body, with partitions arranged between adjacent test chambers; a sample placement window is opened above the test chamber; a specimen rack is arranged in the test chamber, a pressure sensor is arranged at the end of the specimen rack, the specimen rack contacts the partition through the pressure sensor, and a temperature control device is also arranged in the partition; a dynamic elastic modulus tester is installed in the specimen rack; the dynamic elastic modulus tester, the temperature control device and the pressure sensor are all connected to the control panel; a water outlet is arranged below the test chamber, and a water inlet is arranged on the side of the test chamber.

2. A concrete freeze-thaw cycle testing machine as claimed in claim 1, characterized in that: At least two rows of test chambers are arranged in the main body of the test machine, and each row is provided with at least four test chambers.

3. A concrete freeze-thaw cycle testing machine as claimed in claim 1, characterized in that: The test piece rack is a support structure formed by a plurality of U-shaped metal wires arranged vertically and horizontally; both ends of the metal wires are fixedly connected to one side of the upper part of the pressure sensor, and the metal wires are wrapped with rubber.

4. A concrete freeze-thaw cycle testing machine as claimed in claim 1, characterized in that: The lower part of the pressure sensor is fixedly connected to the edge of the lofting window on the top of the test chamber.

5. A concrete freeze-thaw cycle testing machine as claimed in claim 1, characterized in that: The edge of the lofting window is provided with mounting holes for the dynamic elastic modulus tester, and the mounting holes are arranged in a vertical direction.

6. A concrete freeze-thaw cycle testing machine as claimed in claim 5, characterized in that: The dynamic elastic modulus tester consists of a transmitter, a receiver, a mounting bracket and a folding rod; the mounting bracket is a U-shaped structure, the transmitter and the receiver are mounted at one end of the opening of the mounting bracket, and the transmitter and the receiver are arranged relative to each other; the end of the mounting bracket away from the opening is connected to one end of the folding rod, and the mounting bracket and the folding rod are hingedly connected.

7. A concrete freeze-thaw cycle testing machine as claimed in claim 6, characterized in that: The other end of the folding rod is inserted into the mounting hole.

8. A concrete freeze-thaw cycle testing machine as claimed in claim 7, characterized in that: The water inlet and the water outlet are respectively provided with electromagnetic valves, and the electromagnetic valves are connected to the control panel.

9. A concrete freeze-thaw cycle testing machine as claimed in claim 8, characterized in that: The control panel is arranged on one side of the testing machine, and the control panel is provided with a touch screen for displaying test data and for controlling the electromagnetic valve and the temperature control device; The testing machine body and the cover plate are hinged to facilitate opening and closing of the cover plate.

10. A method for using a concrete freeze-thaw cycle testing machine according to any one of claims 2 to 9, characterized in that: include: S1. Prepare concrete beam specimens according to the specification requirements, soak them in water at a set temperature for N days. The water level should be higher than the top surface of the specimens during soaking. After soaking, select the curing age according to different specimen types to cure the specimens. After curing, conduct subsequent tests; S2. Take out the specimens that have reached the curing age, wipe off the surface moisture, measure the appearance dimensions, put them into the specimen rack of the testing machine according to the number, weigh the initial mass of each specimen, and obtain the data on the control panel; S3. Operate the control panel, use the control panel to control the electromagnetic valve at the water inlet to open, inject water into the water inlet, the water level is higher than the top surface of the specimen, use the control panel to control the electromagnetic valve at the water inlet to close, and then perform freeze-thaw cycles in accordance with the specification requirements; S4. After every 25 cycles, operate the control panel to control the electromagnetic valve at the water outlet to open, drain water through the water outlet, observe the changes in the appearance of the specimen, and use the dynamic elastic modulus tester to test, until the water in the test chamber is completely drained, the electromagnetic valve at the water outlet is closed; S5. Retrieve various data from the control panel for analysis.

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