Method and device for rapidly and intelligently testing water absorption rate of concrete

Abstract

The invention discloses a method and a device for rapidly and intelligently testing the water absorption rate of concrete. The device is mainly composed of a display screen, a test grid, a test box cover plate, a test box, a stainless steel mesh, a temperature sensor, an infrared distance measuring sensor, a pressurizing hole, a water injection hole, a temperature control device, a pressurizing device, a computer host and a water storage device. And the water absorption rate of the concrete can be tested under the pressure of 0-2MPa and the water temperature of 0-80 DEG C. The test piece can be a cube with the size of 100 mm * 100 mm * 100 mm or a cylinder with the size of phi 100 mm * 100 mm. The device has the characteristics of controllable and adjustable pressure and temperature, automatic measurement of liquid level change, real-time display of water absorption and synchronous implementation of multiple groups of tests, and the accuracy, reliability and automation degree of concrete water absorption testing are remarkably improved.

Description

Technical Field

[0001] The invention relates to the field of concrete material property testing, and in particular to a method and device for rapid intelligent testing of concrete water absorption. Background Art

[0002] The durability of reinforced concrete structures depends on the rate and process of the migration of corrosive media into the material, among which water transfer is the most basic and critical. Water is a direct participant in the freeze-thaw damage process of concrete and a carrier for the migration of corrosive media such as chloride ions. The water content significantly affects the migration rate of media such as carbon dioxide and oxygen, and has an important impact on durability degradation.

[0003] Several international standards, represented by ISO standard ISO 15148:2002 / Amd2016 and American Society for Testing and Materials standard ASTM C1585-20, have established standard test methods for capillary water absorption of concrete. In GB / T50081-2019 "Standard for Test Methods for Physical and Mechanical Properties of Concrete", my country uses the weight method to test the water absorption of concrete, that is, the water absorption is calculated by measuring the cumulative water absorption mass per unit area. However, the test specimen needs to be taken out many times during the test, and it is impossible to measure automatically in real time, the measurement error is large, and the test time is as long as several days. The ambient temperature of concrete structures during service varies greatly, which has a great impact on the water absorption of concrete. The existing test methods (CN 218823808 U, CN 105588778 B, CN108132206B, CN 113533141A) do not consider the influence of temperature, let alone the influence and test problems under different temperatures and pressures.

[0004] my country has a large-scale concrete infrastructure. In order to better serve the durability evaluation of concrete, a rapid intelligent testing method and device for concrete water absorption is proposed, which is an urgent problem to be solved by the present invention. Summary of the invention

[0005] In view of this, the present invention proposes a concrete water absorption test method and device which can test different pressures, temperatures and specimen sizes.

[0006] The present invention adopts the following technical solution:

[0007] A rapid intelligent testing device for concrete water absorption, comprising a display screen, a plurality of test grids, a test box cover, a test box, a stainless steel mesh, a temperature sensor, an infrared ranging sensor, a pressurizing hole, a water injection hole, a temperature control device, a pressurizing device, a computer host, and a water storage device;

[0008] The display screen can display the temperature, pressure, liquid level change and water absorption rate in each test cell in real time;

[0009] The bottom of each test cell is a stainless steel mesh, a temperature sensor and a temperature control device;

[0010] The test box cover is connected to the test box, so that a closed space with constant temperature and pressure is formed in each test cell, and the top of the test box cover is an infrared ranging sensor, a pressurization hole and a water injection hole;

[0011] The multiple test cells can be set with different pressures and water temperatures, and the temperature control device in each test cell is relatively independent, so that water absorption tests at different temperatures and pressures can be performed simultaneously;

[0012] The pressurized holes in each test cell are relatively independent, and water absorption tests at different pressures can be carried out simultaneously.

[0013] Furthermore, the pressurizing device is connected to the water storage device through a first rubber hose; water can be automatically injected during the test, and the water injection button is clicked on the display screen, so that the gas in the pressurizing device enters the water storage device through the first rubber hose, so that water is injected into the test grid through the second rubber hose in the test box cover; the infrared ranging sensor automatically monitors the change of the liquid level and responds in real time on the display screen, and when the liquid level change reaches the set value, the water injection is stopped.

[0014] Furthermore, pressure and temperature buttons are set on the display screen, and the start button is clicked. The pressurizing device applies air pressure to the test box through the third rubber hose and the pressurizing hole in the test box cover. At the same time, the temperature control device at the bottom of the test grid starts working. When the set pressure and temperature are reached, the pressurization and heating are stopped.

[0015] Furthermore, the maximum size of the specimen may be a 100 mm × 100 mm × 100 mm concrete cube or a φ100 mm × 100 mm cylinder.

[0016] Furthermore, the temperature control device can control the water temperature to change between 0°C and 80°C to test the water absorption rate of concrete at different temperatures; the test grid is made of constant temperature material, which can keep the water temperature in the test grid constant.

[0017] Furthermore, the pressurizing device can control the pressure to be stable at 0MPa to 2MPa, and the pressure value can be set according to the detection requirements to accelerate the test process.

[0018] Furthermore, the infrared distance measuring sensor has a detection distance of 1 mm to 50 mm, and can automatically detect changes in the liquid level by emitting infrared signals, and can automatically transmit changes in the liquid level to the computer host and reflect them on the display screen; and / or,

[0019] The temperature sensor and infrared distance sensor are connected to the computer host through signal lines, and real-time monitoring can be performed.

[0020] Furthermore, the water absorption of concrete is calculated according to the following formula.

[0021]

[0022] Where: s is the cross-sectional area of ​​the test cell, h is the drop in liquid level, ρ is the density of water at the heating temperature, and m is the mass of the concrete specimen in the dry state.

[0023] A quick and intelligent method for testing the water absorption of concrete is also provided. Using the above-mentioned testing device, a test piece is first made for water absorption testing. The testing steps are as follows:

[0024] S1: Drying the concrete specimens;

[0025] S2: Set the test system, that is, set the temperature and pressure of the concrete specimen;

[0026] S3: Place the dried specimen into the test grid, and connect the test box cover to the test box through the connecting device; start the computer host, and the indicator lights of each sensor on the display screen show normal, and start the test;

[0027] S4: First, water is automatically injected. Click the water injection button on the display screen. The gas in the pressurizing device enters the water storage device through the rubber hose, so that water is injected into the six test cells through the second rubber hose in the test box cover. The infrared ranging sensor automatically monitors the change of the liquid level and reflects it in real time on the display screen. When the change of the liquid level reaches the set value, the test cell automatically stops injecting water, and the rubber hose channel between the pressurizing device and the water storage device is closed.

[0028] S5: Set the pressure and temperature of each test cell on the display screen, click the start button to start the test; the pressurizing device applies air pressure to the test box through the third rubber hose and the pressurizing hole in the test box cover, and the temperature control device at the bottom of the test cell starts working. When the set pressure and temperature are reached, the pressurization and heating are stopped;

[0029] S6: During this process, the infrared ranging sensor continuously monitors the changes in the liquid level and reflects it on the display screen. When the liquid level no longer changes, the test is stopped.

[0030] Furthermore, the drying is as follows: drying the specimen in a blast drying oven controlled at (105±5)°C for 24 hours, cooling it to room temperature and weighing it; continuing to dry it for 24 hours, taking out the specimen, cooling it to room temperature, and recording the mass of the specimen; the specimen drying time should not be less than 48 hours, until the mass change between two consecutive 24-hour intervals is less than 0.2% of the smaller value, stopping the drying, and recording the mass m of the specimen;

[0031] Six concrete specimens were used, and the temperature and pressure of the six specimens were as follows: specimen 1: 20℃, 0.5MPa; specimen 2: 20℃, 1MPa; specimen 3: 20℃, 1.5MPa; specimen 4: 60℃, 0.5MPa; specimen 5: 60℃, 1MPa; specimen 6: 60℃, 1.5MPa.

[0032] Technical effects of the present invention:

[0033] The present invention can simultaneously carry out rapid intelligent testing of concrete water absorption rate at different pressures (0MPa-2MPa), different temperatures (0°C-80°C), and different sizes (maximum size is 100mm×100mm×100mm cube or φ100mm×100mm cylinder, etc.).

[0034] 1. Comprehensive evaluation: Tests under different temperature and pressure conditions can provide more comprehensive concrete water absorption data. These data reflect the water absorption performance of concrete under different environmental conditions, helping engineers and researchers to more comprehensively evaluate the actual use of concrete materials.

[0035] 2. Adapt to different environments: Considering that concrete may face different temperature and humidity conditions in actual applications, multi-condition testing can simulate water absorption in various environments and provide more accurate data support for actual engineering design.

[0036] 3. Save time and cost: By setting up multiple test conditions for testing at one time, more data can be obtained in a shorter time, thus saving experimental time and cost. This is especially important for concrete material evaluation for large-scale or complex projects.

[0037] 4. Optimize concrete formula and design: By comparing the water absorption data under different conditions, it can help engineers optimize concrete formula and structural design to improve the concrete's impermeability and durability, and ensure its long-term stability and performance in different environments.

[0038] 5. Scientific research and theoretical exploration: Systematic research on water absorption under multiple conditions will help to deeply understand the water absorption mechanism and influencing factors of concrete materials at the molecular level, and provide a scientific basis for the further development and improvement of concrete materials.

[0039] In summary, conducting concrete water absorption tests at different temperatures and pressures simultaneously not only helps to improve the comprehensiveness and accuracy of the test, but also provides important data support and theoretical basis for the engineering application and scientific research of concrete materials. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] 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 embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying creative work.

[0041] Figure 1 It is the overall structure diagram of the water absorption test device in the present invention.

[0042] Figure 2 It is a front view of the test box of the water absorption test device in the present invention.

[0043] Figure 3 It is a structural diagram of the control system of the water absorption test device in the present invention.

[0044] 1 display screen, 2 test grid, 3 test box cover, 4 is the test box as a whole, 5 stainless steel mesh, 6 temperature sensor, 7 infrared ranging sensor, 8 pressurizing hole, 9 water injection hole, 10 temperature control device, 11 pressurizing device, 12 computer host, 13 water storage device. DETAILED DESCRIPTION

[0045] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0046] The present embodiment provides a rapid intelligent testing device for concrete water absorption, comprising a display screen 1, a plurality of test grids 2, a test box cover 3, a test box 4, a stainless steel mesh 5, a temperature sensor 6, an infrared ranging sensor 7, a pressurizing hole 8, a water injection hole 9, a temperature control device 10, a pressurizing device 11, a computer host 12, and a water storage device 13;

[0047] The display screen 1 can display the temperature, pressure, liquid level change and water absorption rate in each test cell 2 in real time;

[0048] The bottom of each test cell 2 is a stainless steel mesh 5, a temperature sensor 6 and a temperature control device 10;

[0049] The test box cover 3 is connected to the test box 4, so that a closed space with constant temperature and pressure is formed in each test cell 2. The top of the test box cover 3 is an infrared distance sensor 7, a pressurization hole 8 and a water injection hole 9;

[0050] The multiple test cells 2 can be set with different pressures and water temperatures. The temperature control device 10 in each test cell 2 is relatively independent, and water absorption tests at different temperatures and pressures can be performed simultaneously.

[0051] The pressurized holes in each test cell 2 are relatively independent, and water absorption tests at different pressures can be performed simultaneously.

[0052] The pressurizing device 11 is connected to the water storage device 13 through a first rubber hose. Water can be automatically injected during the test. When the water injection button is clicked on the display screen 1, the gas in the pressurizing device 11 enters the water storage device 13 through the first rubber hose, so that water is injected into the test grid 2 through the second rubber hose in the test box cover. The infrared ranging sensor 7 automatically monitors the change of the liquid level and responds in real time on the display screen 1. When the change of the liquid level reaches the set value, the water injection is stopped.

[0053] Set the pressure and temperature buttons on the display screen 1, click the start button, and the pressurizing device 11 applies air pressure to the test box 4 through the third rubber hose and the pressurizing hole 8 in the test box cover. At the same time, the temperature control device 10 at the bottom of the test grid 2 starts to work. When the set pressure and temperature are reached, the pressurization and heating are stopped.

[0054] The maximum size of the specimen can be a 100mm×100mm×100mm concrete cube or a φ100mm×100mm cylinder.

[0055] The temperature control device 10 can control the water temperature to change between 0°C and 80°C to test the water absorption rate of concrete at different temperatures; the test cell 2 is made of a constant temperature material, which can keep the water temperature in the test cell constant.

[0056] The pressurizing device 11 can control the pressure to be stable at 0MPa to 2MPa, and the pressure value can be set according to the detection requirements to accelerate the test process.

[0057] The infrared distance measuring sensor 7 has a detection distance of 1 mm to 50 mm, and automatically detects the change of the liquid level by emitting infrared signals, and can automatically transmit the change of the liquid level to the computer host 12 and reflect it on the display screen 1; and / or,

[0058] The temperature sensor 6 and the infrared distance sensor 7 are connected to the computer host 12 via a signal line, and real-time monitoring can be performed.

[0059] Calculate the water absorption of concrete according to the following formula.

[0060]

[0061] Where: s is the cross-sectional area of ​​the test cell, h is the drop in liquid level, ρ is the density of water at the heating temperature, and m is the mass of the concrete specimen in the dry state.

[0062] In this embodiment, C40 ordinary concrete was selected to make six cubic specimens of 100 mm×100 mm×100 mm for water absorption test.

[0063] S1: Dry the concrete specimens according to the drying system in GB / T 50081 "Standard for Test Methods of Physical and Mechanical Properties of Concrete". Place the specimens in a forced air drying oven controlled at (105±5)℃ and dry for 24 hours, then cool to room temperature and weigh. Continue drying for 24 hours, take out the specimens, cool to room temperature, and record the mass of the specimens; the drying time of the specimens should not be less than 48 hours, until the mass change between two consecutive 24-hour intervals is less than 0.2% of the smaller value, stop drying, and record the mass m of the specimens.

[0064] S2: Set up the test system. The temperature and pressure of the six test blocks are as follows: Test block 1: 20℃, 0.5MPa; Test block 2: 20℃, 1MPa; Test block 3: 20℃, 1.5MPa; Test block 4: 60℃, 0.5MPa; Test block 5: 60℃, 1MPa; Test block 6: 60℃, 1.5MPa.

[0065] S3: Place the dried test piece into the test grid 2, and connect the test box cover 3 to the test box 4 through the connecting device. Start the computer host 12, and the indicator lights of each sensor on the display screen 1 are normal, and the test begins.

[0066] S4: First, water is automatically injected. Click the water injection button on the display screen 1. The gas in the pressurizing device 11 enters the water storage device 13 through the rubber hose, so that water is injected into the six test cells 2 through the second rubber hose in the test box cover 3. The infrared ranging sensor 7 automatically monitors the change of the liquid level and reflects it in real time on the display screen 1. When the change of the liquid level reaches 150mm, the test cell automatically stops injecting water, and the rubber hose channel between the pressurizing device 11 and the water storage device 13 is closed.

[0067] S5: Set the pressure and temperature of each test cell 2 on the display screen 1, click the start button to start the test. The pressurizing device 11 applies air pressure to the test box 4 through the third rubber hose and the pressurizing hole 8 in the test box cover 3, and the temperature control device 10 at the bottom of the test cell 2 starts working. When the set pressure and temperature are reached, the pressurization and heating are stopped.

[0068] S6: The infrared distance measuring sensor 7 continuously monitors the change of the liquid level during this process and reflects it on the display screen 1. When the liquid level no longer changes, the test is stopped.

[0069] The test results are shown in Table 1:

[0070]

[0071]

[0072] In this specification, each embodiment is described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the embodiments can be referred to each other. For the device disclosed in the embodiment, since it corresponds to the method disclosed in the embodiment, the description is relatively simple, and the relevant parts can be referred to the method part.

[0073] The above description of the disclosed embodiments enables one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A rapid intelligent testing device for concrete water absorption, characterized in that: It comprises a display screen (1), a plurality of test grids (2), a test box cover (3), a test box (4), a stainless steel mesh (5), a temperature sensor (6), an infrared distance sensor (7), a pressurizing hole (8), a water injection hole (9), a temperature control device (10), a pressurizing device (11), a computer host (12), and a water storage device (13); The display screen (1) can display the temperature, pressure, liquid level change and water absorption rate in each test cell (2) in real time; The bottom of each test cell (2) is provided with a stainless steel mesh (5), a temperature sensor (6) and a temperature control device (10); The test box cover (3) is connected to the test box (4) so ​​that a closed space with constant temperature and pressure is formed in each test cell (2); the top of the test box cover (3) is provided with an infrared distance measuring sensor (7), a pressurizing hole (8) and a water injection hole (9); The multiple test cells (2) can be set with different pressures and water temperatures, and the temperature control device (10) in each test cell (2) is relatively independent, so that water absorption tests at different temperatures and pressures can be performed simultaneously; The pressure holes in each test cell (2) are relatively independent, and water absorption tests at different pressures can be performed simultaneously.

2. According to claim 1, a rapid intelligent testing device for concrete water absorption is characterized by: The pressurizing device (11) is connected to the water storage device (13) via a first rubber hose; water can be automatically injected during the test process; by clicking a water injection button on the display screen (1), the gas in the pressurizing device (11) enters the water storage device (13) through the first rubber hose, so that water is injected into the test cell (2) through a second rubber hose in the test box cover; the infrared distance measuring sensor (7) automatically monitors the change in liquid level and reflects it in real time on the display screen (1); when the change in liquid level reaches a set value, water injection is stopped.

3. According to claim 2, a rapid intelligent testing device for concrete water absorption is characterized in that: exist The display screen (1) is provided with pressure and temperature buttons. When the start button is clicked, the pressurizing device (11) applies air pressure to the test box (4) through the third rubber hose and the pressurizing hole (8) in the test box cover. At the same time, the temperature control device (10) at the bottom of the test grid (2) starts to work. When the set pressure and temperature are reached, the pressurizing and heating is stopped.

4. The rapid intelligent testing device for concrete water absorption according to claim 1 is characterized in that: The maximum size of the specimen can be a 100mm×100mm×100mm concrete cube or a φ100mm×100mm cylinder.

5. The rapid intelligent testing device for concrete water absorption according to claim 1 is characterized by: The temperature control device (10) can control the water temperature to change between 0°C and 80°C to test the water absorption rate of concrete at different temperatures; the test grid (2) is made of a constant temperature material, which can keep the water temperature in the test grid constant.

6. A rapid intelligent testing device for concrete water absorption according to claim 1, characterized in that: The pressurizing device (11) can control the pressure to be stable at 0MPa-2MPa, and the pressure value can be set according to the detection requirements to accelerate the test process.

7. The rapid intelligent testing device for concrete water absorption according to claim 1 is characterized by: The infrared distance measuring sensor (7) has a detection distance of 1 mm to 50 mm, and automatically detects changes in the liquid level by emitting infrared signals, and can automatically transmit changes in the liquid level to the computer host (12), and reflect them on the display screen (1); and / or, The temperature sensor (6) and the infrared distance measuring sensor (7) are connected to the computer host (12) via a signal line, and real-time monitoring can be performed.

8. The rapid intelligent testing device for concrete water absorption according to claim 1 is characterized by: Calculate the water absorption of concrete according to the following formula. Where: s is the cross-sectional area of ​​the test cell, h is the drop in liquid level, ρ is the density of water at the heating temperature, and m is the mass of the concrete specimen in the dry state.

9. A quick and intelligent method for testing concrete water absorption, using the testing device as described in claims 1-8, firstly making a test piece for water absorption testing, the testing steps are as follows: S1: Drying the concrete specimens; S2: Set the test system, that is, set the temperature and pressure of the concrete specimen; S3: Place the dried test piece into the test grid (2), and connect the test box cover (3) to the test box (4) through a connecting device; start the computer host (12), and the indicator lights of each sensor on the display screen (1) show normal, and start the test; S4: First, water is automatically injected. The water injection button is clicked on the display screen (1). The gas in the pressurizing device (11) enters the water storage device (13) through the rubber hose, so that water is injected into the six test cells (2) through the second rubber hose in the test box cover (3). The infrared distance sensor (7) automatically monitors the change of the liquid level and reflects it in real time on the display screen (1). When the change of the liquid level reaches the set value, the test cell automatically stops injecting water, and at the same time, the rubber hose channel between the pressurizing device (11) and the water storage device (13) is closed. S5: Set the pressure and temperature of each test cell (2) on the display screen (1), click the start button to start the test; the pressurizing device (11) applies air pressure to the test box (4) through the third rubber hose and the pressurizing hole (8) in the test box cover (3), and at the same time, the temperature control device (10) at the bottom of the test cell (2) starts to work. When the set pressure and temperature are reached, the pressurizing and heating are stopped; S6: During this process, the infrared distance measuring sensor (7) continuously monitors the change of the liquid level and reflects it on the display screen (1). When the liquid level no longer changes, the test is stopped.

10. The rapid intelligent testing method for concrete water absorption as claimed in claim 9, characterized in that: The drying comprises: placing the test piece in a blast drying oven controlled at (105±5)°C and drying for 24 hours, cooling to room temperature and weighing; continuing to dry for 24 hours, taking out the test piece, cooling to room temperature and recording the mass of the test piece; the drying time of the test piece shall not be less than 48 hours, until the mass change between two consecutive 24-hour intervals is less than 0.2% of the smaller value, stopping the drying and recording the mass m of the test piece; and / or, Six concrete specimens were used, and the temperature and pressure of the six specimens were as follows: specimen 1: 20℃, 0.5MPa; specimen 2: 20℃, 1MPa; specimen 3: 20℃, 1.5MPa; specimen 4: 60℃, 0.5MPa; specimen 5: 60℃, 1MPa; specimen 6: 60℃, 1.5MPa.

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