Freeze-thaw test device for plateau railway concrete structure exposure test field and use method of freeze-thaw test device

Abstract

The invention relates to a freeze-thaw test device for a plateau railway concrete structure exposure test field and a use method, and belongs to the technical field of freeze-thaw test devices.The freeze-thaw test device comprises a freeze-thaw test box, a water storage tank, a temperature sensor and a one-way switch valve, the top face of the freeze-thaw test box is open, and a plurality of concrete test samples are placed on the inner bottom face of the freeze-thaw test box; the water storage tank is filled with test water and is communicated with the freezing and thawing test box through a water conveying pipe; the temperature sensor is fixed on the inner side box wall of the freezing and thawing test box; the one-way switch valve is fixed in the water conveying pipe. Concrete test samples are placed on the inner bottom face of the freeze-thaw test box at intervals, then test water is introduced into the freeze-thaw test box through the water storage tank, a temperature sensor is fixed in the freeze-thaw test box, a one-way switch valve is fixed in a water conveying pipe, and the horizontal height of the water storage tank is larger than that of the freeze-thaw test box; temperature control and automatic quantitative water replenishing of the freeze-thaw test in the exposed environment of concrete can be realized, and normal operation of the freeze-thaw test in the exposed environment is ensured.

Description

Technical Field

[0001] The invention relates to the technical field of freeze-thaw test devices, and in particular to a freeze-thaw test device for a plateau railway concrete structure exposure test field and a use method thereof. Background Art

[0002] Chinese scholars have always paid great attention to the freeze-thaw damage of concrete structural materials. It can be said that freeze-thaw cycles are one of the biggest causes of damage to concrete structures. Domestic and foreign researchers have conducted extensive and in-depth research on the freeze-thaw damage and deterioration of concrete structures, and proposed many theories and models to explain the damage and deterioration mechanism of concrete under different freeze-thaw environments, mainly including: hydrostatic pressure theory, osmotic pressure theory, crystallization pressure theory, temperature stress hypothesis, critical water saturation theory, frost heave pressure theory, micro-ice crystal lens model theory, water segregation and stratification theory, flushing coefficient theory, pore structure theory, etc. These theoretical models provide a strong theoretical reference for analyzing the deterioration of concrete under different freeze-thaw environments. However, these studies are all based on the research of indoor test environment of concrete, and there are few studies on the performance of concrete in outdoor exposure environment.

[0003] It is generally believed that the freeze-thaw failure mechanism of structural concrete is quite different in indoor test environment and outdoor exposure environment. Under indoor laboratory environment, the test freeze-thaw system is an accelerated test, the degradation factor set in the test is single and has a strong effect; while outdoor structural concrete is in a natural freeze-thaw environment, the effect is more in line with natural laws, and the damage to concrete materials is more in line with actual service conditions.

[0004] Therefore, carrying out freeze-thaw tests on concrete in exposed environments has great theoretical significance and application value. It can be seen that the freeze-thaw test system for concrete is relatively complex and requires a large number of freeze-thaw cycles. To ensure the smooth progress of this test, if manual methods are used, a large amount of manpower, material resources and financial resources are required.

[0005] The present invention proposes a freeze-thaw test device and method for a plateau railway concrete structure exposure test field, which can realize the automation of concrete freeze-thaw tests in an exposure environment. While ensuring the accuracy of the test, it can also save manpower, material and financial resources, and provide equipment support for the research on the freeze-thaw theory and failure mechanism of structural concrete. Summary of the invention

[0006] The invention provides a freeze-thaw test device for a plateau railway concrete structure exposure test field, which solves the technical problems that the existing freeze-thaw test device for railway concrete exposure test field has a complex structure, cumbersome operation and requires a large amount of manpower, physical and financial resources.

[0007] The technical solution of the present invention to solve the above technical problems is as follows: a freeze-thaw test device for a plateau railway concrete structure exposure test field, comprising: a freeze-thaw test box, a water storage tank, a temperature sensor and a one-way switch valve,

[0008] The top surface of the freeze-thaw test box is open and a plurality of concrete test samples are placed on its inner bottom surface; the water storage tank is filled with test water and is connected to the freeze-thaw test box through a water pipe, and the horizontal height of the water storage tank is higher than the horizontal height of the freeze-thaw test box; the temperature sensor is fixed on the inner wall of the freeze-thaw test box; and the one-way switch valve is fixed in the water pipe.

[0009] The beneficial effects of the present invention are as follows: a freeze-thaw test device for a concrete exposure test field is newly designed, and concrete test samples are first spaced apart on the inner bottom surface of a freeze-thaw test box, and then test water is introduced into the freeze-thaw test box through a water storage tank. Since a temperature sensor is fixed in the freeze-thaw test box and a one-way switch valve is fixed in a water pipe, and since the horizontal height of the water storage tank is higher than the horizontal height of the freeze-thaw test box, temperature control and automatic quantitative water replenishment of the concrete exposure environment freeze-thaw test can be achieved, thereby ensuring the normal progress of the exposure environment freeze-thaw test.

[0010] Based on the above technical solution, the present invention can also be improved as follows.

[0011] Furthermore, it also includes a plurality of sample pads, which are spaced apart and placed on the inner bottom surface of the freeze-thaw test box; and a plurality of the concrete test samples are placed on the plurality of sample pads respectively.

[0012] A further beneficial effect of adopting the above method is that placing the concrete test sample on a plurality of sample pads can prevent the concrete test sample from directly contacting the inner bottom surface of the freeze-thaw test box, thereby preventing the concrete test sample from being bumped.

[0013] Furthermore, it also includes a first water level sensor, which is fixed on the inner wall of the freeze-thaw test box.

[0014] A further beneficial effect of adopting the above method is that by fixing the first water level sensor on the inner wall of the freeze-thaw test box, the amount of test water inside the freeze-thaw test box can be monitored in real time to avoid too little test water in the freeze-thaw test box.

[0015] Furthermore, it also includes a second water level sensor, which is fixed on the inner wall of the water tank.

[0016] A further beneficial effect of adopting the above method is that by fixing the second water level sensor on the inner wall of the water tank, the amount of test water in the water tank can be monitored in real time, and the test water can be added to the water tank in time.

[0017] In addition, a plateau railway concrete freeze-thaw test method is provided, and the specific steps are as follows:

[0018] S1. Place the freeze-thaw test device outdoors and ensure that it is dry and rainproof;

[0019] S2. Place the concrete test sample on the inner bottom surface of the exposed freeze-thaw test box, with a total of 4 test pieces placed at a distance of 5 cm from each other;

[0020] S3, add test water to the water tank, the water level is 20cm to 30cm higher than the position of the second water level sensor;

[0021] S4. Open the one-way switch valve to ensure that the water in the water storage tank can smoothly enter the freeze-thaw test chamber, and ensure that the distance between the water surface of the freeze-thaw test chamber and the upper edge of the concrete test sample is 20 cm to 30 cm. At this time, since the water surface height of the water storage tank is parallel to the horizontal height of the freeze-thaw test chamber, the test water in the water storage tank no longer flows into the freeze-thaw test chamber;

[0022] S5. During the test, when the water level in the freeze-thaw test box is lower than the first water level sensor, water is added to the freeze-thaw test box from the water storage tank; when the water level in the water storage tank is lower than the second water level sensor, the second water level sensor alarms to prompt manual water addition, so as to ensure the water level in the freeze-thaw test box;

[0023] S6. During the test, real-time data from the temperature sensor can be extracted and stored in a timely manner;

[0024] S7. When the preset time or the preset number of freeze-thaw cycles is reached, the one-way switch valve is closed, the concrete test sample is taken out, and subsequent concrete performance tests are carried out. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 The present invention is a schematic diagram of the internal structure of a plateau railway concrete freeze-thaw test device.

[0026] In the accompanying drawings, the components represented by the reference numerals are listed as follows:

[0027] 1. Freeze-thaw test chamber, 2. Water storage tank, 3. Temperature sensor, 4. One-way switch valve, 5. Concrete test sample, 6. Sample pad, 7. First water level sensor, 8. Second water level sensor, 9. Water pipe. DETAILED DESCRIPTION

[0028] The principles and features of the present invention are described below in conjunction with the accompanying drawings. The examples given are only used to explain the present invention and are not used to limit the scope of the present invention.

[0029] like Figure 1As shown, a freeze-thaw test device for a plateau railway concrete structure exposure test field comprises: a freeze-thaw test box 1, a water storage tank 2, a temperature sensor 3 and a one-way switch valve 4,

[0030] The top surface of the freeze-thaw test box 1 is open and a plurality of concrete test samples 5 are placed on its inner bottom surface; the interior of the water storage tank 2 is filled with test water and is connected to the freeze-thaw test box 1 through a water pipe 9, and the horizontal height of the water storage tank 2 is higher than the horizontal height of the freeze-thaw test box 1; the temperature sensor 3 is fixed on the inner wall of the freeze-thaw test box 1; and the one-way switch valve 4 is fixed in the water pipe 9.

[0031] In some specific embodiments, a plurality of sample pads 6 may be further included. The plurality of sample pads 6 are spaced apart and placed on the inner bottom surface of the freeze-thaw test box 1 ; and a plurality of concrete test samples 5 are placed on the plurality of sample pads 6 , respectively.

[0032] In some specific embodiments, a first water level sensor 7 may also be included, and the first water level sensor 7 is fixed on the inner wall of the freeze-thaw test chamber 1 .

[0033] In some specific embodiments, a second water level sensor 8 may also be included, and the second water level sensor 8 is fixed on the inner wall of the water storage tank 2 .

[0034] In addition, a plateau railway concrete freeze-thaw test method is provided, and the specific steps are as follows:

[0035] S1. Place the freeze-thaw test device outdoors and ensure that it is dry and rainproof;

[0036] S2, placing the concrete test sample 5 on the inner bottom surface of the exposed freeze-thaw test box 1, placing a total of 4 test blocks with a spacing of 5 cm between them;

[0037] S3, add test water into the water storage tank 2, the water level is 20cm to 30cm higher than the position of the second water level sensor 8;

[0038] S4, open the one-way switch valve 4 to ensure that the water in the water storage tank 2 can smoothly enter the freeze-thaw test chamber 1, and ensure that the distance between the water surface of the freeze-thaw test chamber 1 and the upper edge of the concrete test sample 5 is 20 cm to 30 cm. At this time, since the water surface height of the water storage tank 2 is parallel to the horizontal height of the freeze-thaw test chamber 1, the test water in the water storage tank 2 no longer flows into the freeze-thaw test chamber 1;

[0039] S5. During the test, when the water level in the freeze-thaw test box 1 is lower than the first water level sensor 7, water is added to the freeze-thaw test box 1 from the water storage tank 2; when the water level in the water storage tank 2 is lower than the second water level sensor 8, the second water level sensor 8 alarms, prompting manual water addition, so as to ensure the water level in the freeze-thaw test box 1;

[0040] S6. During the test, the real-time data in the temperature sensor 3 can be extracted and stored in time;

[0041] S7. When the predetermined time or the predetermined number of freeze-thaw cycles is reached, the one-way switch valve 4 is closed, the concrete test sample 5 is taken out, and subsequent concrete performance test experiments are carried out.

[0042] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A freeze-thaw test device for a plateau railway concrete structure exposure test field, characterized in that: include: A freeze-thaw test box (1), wherein the top surface of the freeze-thaw test box (1) is open and a plurality of concrete test samples (5) are placed on the inner bottom surface thereof; A water storage tank (2), wherein the water storage tank (2) contains test water and is connected to the freeze-thaw test chamber (1) via a water pipe (9), and the water storage tank (2) has a higher level than the freeze-thaw test chamber (1); A temperature sensor (3), wherein the temperature sensor (3) is fixed on the inner wall of the freeze-thaw test chamber (1); A one-way switch valve (4), wherein the one-way switch valve (4) is fixed in the water delivery pipe (9).

2. The freeze-thaw test device for a plateau railway concrete structure exposure test field according to claim 1, characterized in that: It also comprises a plurality of sample pads (6), wherein the plurality of sample pads (6) are placed at intervals on the inner bottom surface of the freeze-thaw test box (1); and the plurality of concrete test samples (5) are placed on the plurality of sample pads (6) respectively.

3. The freeze-thaw test device for a plateau railway concrete structure exposure test field according to claim 1, characterized in that: It also comprises a first water level sensor (7), wherein the first water level sensor (7) is fixed on the inner wall of the freeze-thaw test box (1).

4. The freeze-thaw test device for a plateau railway concrete structure exposure test field according to claim 1, characterized in that: It also comprises a second water level sensor (8), wherein the second water level sensor (8) is fixed on the inner wall of the water storage tank (2).

5. A method for using a freeze-thaw test device in a plateau railway concrete structure exposure test field, characterized in that: The freeze-thaw test device for railway concrete exposure test field according to any one of claims 1 to 4 is provided, and the specific steps are as follows: S1, placing a plurality of concrete test samples (5) at intervals on the inner bottom surface of a freeze-thaw test chamber (1); S2. Add test water into the water storage tank (2). S3, opening the one-way switch valve (4), the test water in the water storage tank (2) flows into the freeze-thaw test chamber (1) through the water delivery pipe (9), and when the test water level in the water storage tank (2) is flush with the test water level in the freeze-thaw test chamber (1), the test water in the water storage tank (2) no longer flows into the freeze-thaw test chamber (1); S4. Continue to maintain the above state until the required age for the test is reached, and then take out the concrete test sample (5).

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