A concrete gas permeability testing device

Abstract

This invention relates to the technical field of concrete testing, specifically to a concrete gas permeability testing device, comprising: an environmental simulation system disposed within a second cavity, the environmental simulation system including a gas-liquid injection port, a detection component, and a heating device; liquid and gas enter the second cavity through the gas-liquid injection port, the heating device is used to heat the liquid, and the detection component is used to detect the temperature, humidity, and pressure values ​​within the second cavity; a gas measurement system disposed within a first cavity, the gas measurement system being used to measure the volume of gas permeating from the second cavity into the first cavity through the concrete specimen; and a specimen fixing system for fixing the concrete specimen. This concrete gas permeability testing device can perform gas permeability testing and real-time monitoring of temperature field and moisture distribution on concrete specimens under the coupled effects of different high temperature, high humidity, and high pressure environmental conditions.

Description

Technical Field

[0001] This invention relates to the technical field of concrete testing, specifically to a concrete gas permeability testing device under high temperature, high humidity, and high pressure coupling. Background Technology

[0002] Concrete is a porous, multiphase medium with numerous pores. Under pressure gradients, gases migrate from high-pressure areas to low-pressure areas through these interconnected pores. This property of allowing gas transport within the pore structure of concrete is its gas permeability. Therefore, the pore structure of concrete, especially the amount of interconnected pores, is the primary factor affecting its gas permeability. Additionally, water, a liquid phase, is present within concrete. The presence of water obstructs gas flow channels, leading to a decrease in gas permeability. Thus, the pore water saturation level is also an important indicator of concrete gas permeability. When the pore water saturation level within concrete reaches a certain critical value, all interconnected pores are blocked, and gas flow within the concrete ceases.

[0003] The environmental conditions under which concrete structures are used, such as temperature, humidity, and gas pressure, also affect the gas permeability of concrete. Driven by temperature, humidity, and pressure gradients, heat and water vapor will conduct and permeate into the concrete, thus affecting the distribution of the internal temperature and humidity field. The specific effects are mainly reflected in the following four aspects: (i) Moisture can easily enter the interior of the concrete structure and come into contact with unhydrated cement particles. The increase in temperature will also promote the continued hydration of unhydrated cement particles, thereby changing the pore structure of the concrete; (ii) The evaporation of free water and the dehydration of bound water produced by the heating of concrete will also increase the pore size of the concrete and even produce microcracks; (iii) The increase in the water content of concrete reduces the air permeability pores. At the same time, the temperature gradient, humidity gradient, and pore pressure gradient within the concrete will promote the migration of internal moisture, forming a local high saturation phenomenon similar to "wet resistance"; (iv) The pore pressure inside the concrete will cause microcracks to expand, increase the transport channels of capillary water and water vapor, and promote the mass transfer of water into the interior of the concrete wall.

[0004] Containing concrete walls typically have significant thickness. Under the combined effects of high temperature, high humidity, and high pressure, their temperature, moisture distribution, pore structure, and gas permeability exhibit time-varying and non-uniform characteristics. To reflect these variations, gas permeability tests under high temperature, high humidity, and high pressure environments are required using concrete specimens of the same thickness. Existing laboratory measurement methods are insufficient for large specimens, while in-situ testing methods struggle to apply the necessary high temperature, high humidity, and high pressure conditions. Therefore, a dedicated testing apparatus is needed to study this issue. Gas permeability is a crucial indicator of concrete durability, representing the first line of defense for concrete durability. In-depth research into the gas permeability of concrete, understanding its permeation mechanism, is essential for durability assessment and remaining life prediction of in-service concrete structures. Furthermore, it can be used for durability prediction of new projects, significantly improving engineering design standards, extending building lifespan, and reducing carbon emissions. Summary of the Invention

[0005] Therefore, the technical problem to be solved by the present invention is to overcome the problem that the above-mentioned laboratory measurement methods in the prior art are difficult to measure large specimens, and the in-situ testing methods are difficult to apply environmental conditions of high temperature, high humidity and high pressure, so as to provide a concrete gas permeability testing device.

[0006] To address the aforementioned technical problems, this invention provides a concrete gas permeability testing device, comprising: an environmental simulation system disposed within a second cavity, the environmental simulation system including a gas-liquid injection port, a detection component, and a heating device; liquid and gas enter the second cavity through the gas-liquid injection port, the heating device is used to heat the liquid, and the detection component is used to detect the temperature, humidity, and pressure values ​​within the second cavity; a gas measurement system disposed within a first cavity, the gas measurement system being used to measure the volume of gas in the second cavity permeating into the first cavity through the concrete specimen; and a specimen fixing system disposed between the environmental simulation system and the gas measurement system, used to fix the concrete specimen, the concrete specimen having a set slope, and a sensor array being disposed within the concrete specimen.

[0007] Furthermore, it includes two implementation methods: a combined gas permeability testing device or an adjustable environmental condition gas permeability measuring device.

[0008] Furthermore, the detection components of the environmental simulation system include an ambient temperature sensor, a humidity sensor, and a pressure sensor. The ambient temperature sensor is used to detect the temperature value inside the second cavity, the humidity sensor is used to detect the humidity value inside the second cavity, and the pressure sensor is used to detect the pressure value inside the second cavity. The environmental simulation system also includes a ceramic pad, and a heating device is mounted on the ceramic pad.

[0009] Further, it includes: a cylindrical body, mounted on a fixed frame, the cylindrical body comprising a first steel cylinder and a second steel cylinder, the first steel cylinder having a first cavity and the second steel cylinder having a second cavity; a supporting structure between the first steel cylinder and the second steel cylinder, the supporting structure being used to support the concrete specimen; a heat insulation component, mounted on the outer wall of the cylindrical body; and a sealing structure, mounted between the first cavity and the second cavity, the sealing structure being used to seal the concrete specimen, the first cavity, and the second cavity.

[0010] Furthermore, the gas measurement system of the combined gas permeability testing device includes: a temperature and humidity sensor located inside the first cavity; a liquid meter penetrating the cylinder and extending into the first cavity, used to detect the volume of liquid in the first cavity; a water tank penetrating the cylinder and extending into the first cavity, used to detect the end of the first cavity away from the concrete specimen; and a metering device connected to the water tank. The gas measurement system also includes a timed camera used to record the water volume in the liquid meter and the metering device at regular intervals.

[0011] Furthermore, the gas measurement system of the adjustable environmental condition gas permeability measuring device includes a gas collection device and a sealing sleeve. The gas collection device is fitted onto the top of the concrete specimen, and the sealing sleeve is used for the first cavity.

[0012] Furthermore, the concrete gas permeability testing device also includes a safety protection system, which includes a wire mesh, an acrylic glass cover, and fuses. The wire mesh and acrylic glass cover are placed around the outer perimeter of the device to prevent gas leakage during the test and to prevent the high-temperature and high-pressure gas inside from burning the test personnel. Fuses are installed in the heating device and each circuit.

[0013] Furthermore, the combined gas permeability testing device also includes a cooling water circulation system, which is located on the outer wall of the cylinder and is used to cool the cylinder.

[0014] Furthermore, the adjustable environmental condition gas permeability measuring device also includes a circulating gas inlet and a circulating gas outlet, which are located on the cavity wall of the second cavity.

[0015] Furthermore, the sensor group includes a specimen temperature sensor, a resistivity sensor, and a gas pressure sensor, which are staggered within the concrete specimen.

[0016] The technical solution of this invention has the following advantages:

[0017] 1. The concrete gas permeability testing device provided by the present invention includes: an environmental simulation system disposed in a second cavity, the environmental simulation system including a gas-liquid injection port, a detection component, and a heating device; liquid and gas enter the second cavity through the gas-liquid injection port, the heating device is used to heat the liquid, and the detection component is used to detect the temperature, humidity, and pressure values ​​in the second cavity; a gas measurement system disposed in a first cavity, the gas measurement system being used to measure the volume of gas in the second cavity permeating into the first cavity through the concrete specimen; and a specimen fixing system disposed between the environmental simulation system and the gas measurement system, used to fix the concrete specimen, the concrete specimen having a set slope, and a sensor group being provided inside the concrete specimen.

[0018] The cylindrical body is divided into two cavities: a first cavity and a second cavity. The concrete specimen is placed in the first cavity. A gas measurement system can be installed in the first cavity, and an environmental simulation system in the second cavity. During actual use, the concrete gas permeability testing device injects liquid and gas into the second cavity through the gas-liquid injection port. A heating device then heats and pressurizes the water and gas within the second cavity. Once the environment reaches the expected temperature and pressure and stabilizes, the concrete gas permeability test begins. A detection component installed in the second cavity monitors relevant indicators within the cavity, namely temperature, humidity, and pressure, and reflects these values ​​in real time to the control system. This information is used to adjust the opening and closing of the heating device, thereby ensuring stable internal environmental conditions. The gas measurement system detects the gas flow rate permeating from the concrete specimen and the gas state changes within the second cavity. After the test, a drain outlet is used to depressurize the concrete gas permeability testing device and drain any remaining water.

[0019] Traditional gas permeability testing apparatuses can only study the influence of single factors on the gas permeability of concrete. Furthermore, the specimen size is limited; for example, they can only study the effects of temperature or air pressure on gas permeability, and cannot investigate the gas permeability of concrete coupled with multiple environmental factors. During the experiment, as water vapor liquefies, water droplets form on the surface of the concrete specimen. These water droplets inhibit the rate at which gas passes through the concrete surface, thus biasing the test results.

[0020] This concrete gas permeability testing device can provide a precise high temperature, high humidity, and high pressure testing environment, and can conduct gas permeability tests and real-time monitoring of temperature field and moisture distribution on concrete specimens under the coupled effects of different high temperature, high humidity, and high pressure environmental conditions.

[0021] This invention designs a liquid meter to collect water liquefied from water vapor on the upper surface of concrete specimens. To allow water droplets to flow out better, the upper surface of the concrete specimen is made into a slope of 2-8%. The space between the concrete specimen and the cylinder is filled with a high-temperature resistant adhesive, or a sealed space is left between the concrete specimen and the cylinder wall, which can reduce the accuracy requirements of the concrete specimen. Large-volume concrete may have dimensional deviations during pouring and curing. This concrete gas permeability testing device can solve the problem of uneven concrete specimen surface and greatly reduce the difficulty of the test.

[0022] 2. The concrete gas permeability testing device provided by the present invention includes a specimen temperature sensor, a resistivity sensor, and a gas pressure sensor, wherein the specimen temperature sensor, the resistivity sensor, and the gas pressure sensor are staggered within the concrete specimen.

[0023] Temperature sensors, resistivity sensors, and gas pressure sensors are pre-embedded at different depths in the concrete specimen to measure the temperature, moisture content, and pore pressure at different depths. The outputs of the temperature sensors, resistivity sensors, and gas pressure sensors are led out from the side of the concrete specimen.

[0024] The summary section is provided to present the chosen concepts in a simplified form, which will be further described in the detailed description below. The summary section is not intended to identify essential or necessary features of this disclosure, nor is it intended to limit the scope of this disclosure. Attached Figure Description

[0025] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0026] Figure 1 A schematic diagram of the combined gas permeability measuring device for the concrete gas permeability testing apparatus provided by the present invention;

[0027] Figure 2 A partial schematic diagram of the connection between the first and second steel cylinders of the combined gas permeability measuring device for the concrete gas permeability testing apparatus provided by the present invention.

[0028] Figure 3 A top view of the first steel cylinder of the combined gas permeability testing device for concrete provided by the present invention;

[0029] Figure 4A schematic diagram of the adjustable environmental conditions gas permeability measuring device of the concrete gas permeability testing apparatus provided by the present invention.

[0030] Explanation of reference numerals in the attached figures:

[0031] 1. Cylinder body; 2. Fixing frame; 3. First cavity; 4. Second cavity; 5. Specimen fixing system; 6. Drain outlet; 7. Concrete specimen; 8. Sensor group; 9. Thermal insulation component; 10. Support structure; 11. Environmental simulation system; 12. Gas-liquid injection port; 13. Heating device; 14. Cooling water circulation system; 15. Gas measurement system; 16. Ambient temperature sensor; 17. Humidity sensor; 18. Air pressure sensor; 19. Ceramic pad; 20. Temperature and humidity sensor; 21. Liquid metering device; 22. Water tank; 23. Metering device; 24. Timer camera; 26. First steel cylinder; 27. Second steel cylinder; 28. Circulating gas injection port; 29. ​​Circulating gas outlet; 30. Gas outlet; 31. Liquid outlet; 32. Sealing gasket; 33. First sealing bolt; 34. Second sealing bolt; 35. Gas collection device; 36. Sealing sleeve; 37. Bolt. Detailed Implementation

[0032] In the following description, only certain exemplary embodiments are briefly described. As those skilled in the art will recognize, the described embodiments can be modified in various ways without departing from the spirit or scope of this disclosure. Therefore, the drawings and description are to be considered exemplary in nature and not restrictive.

[0033] In the description of this disclosure, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," and "counterclockwise," etc., indicating orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, are only for the convenience of describing this disclosure and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this disclosure. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the stated features. In the description of this disclosure, "a plurality of" means two or more, unless otherwise explicitly specified.

[0034] In the description of this disclosure, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "joint" should be interpreted broadly. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections, electrical connections, or connections that allow for communication; they can refer to direct connections or indirect connections through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this disclosure according to the specific circumstances.

[0035] In this disclosure, unless otherwise expressly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature being directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature being directly above or diagonally above the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0036] The following disclosure provides numerous different embodiments or examples for implementing various structures of this disclosure. To simplify the disclosure, specific examples of components and arrangements are described below. These are merely examples and are not intended to limit the scope of this disclosure. Furthermore, reference numerals and / or letters may be repeated in different examples; such repetition is for simplification and clarity and does not in itself indicate a relationship between the various embodiments and / or arrangements discussed. In addition, various specific examples of processes and materials are provided in this disclosure, but those skilled in the art will recognize the application of other processes and / or the use of other materials.

[0037] The preferred embodiments of this disclosure are described below with reference to the accompanying drawings. It should be understood that the preferred embodiments described herein are for illustration and explanation only and are not intended to limit this disclosure.

[0038] Please see Figures 1 to 4As shown, the present invention provides a concrete gas permeability testing device, comprising: an environmental simulation system 11 disposed within a second cavity 4, the environmental simulation system 11 including a gas-liquid injection port 12, a detection component, and a heating device 13; liquid and gas enter the second cavity 4 through the gas-liquid injection port 12, the heating device 13 is used to heat the liquid, and the detection component is used to detect the temperature, humidity, and pressure values ​​within the second cavity 4; a gas measurement system 15 disposed within a first cavity 3, the gas measurement system 15 being used to measure the volume of gas in the second cavity 4 permeating into the first cavity 3 through the concrete specimen 7; and a specimen fixing system 5 disposed between the environmental simulation system 11 and the gas measurement system 15, used to fix the concrete specimen 7, the concrete specimen 7 having a set slope, and a sensor group 8 being provided within the concrete specimen.

[0039] The cylinder 1 is divided into two cavities: a first cavity 3 and a second cavity 4. The concrete specimen 7 is placed in the first cavity 3. A gas measurement system 15 can be installed in the first cavity 3, and an environmental simulation system 11 can be installed in the second cavity 4. During actual use, the concrete gas permeability testing device injects liquid and gas into the second cavity 4 through the gas-liquid injection port 12. The water and gas in the second cavity 4 are heated and pressurized by the heating device 13. Once the environment reaches the expected temperature and pressure and stabilizes, the concrete gas permeability test begins. The detection components installed in the second cavity 4 can monitor relevant indicators within the cavity, namely temperature, humidity, and pressure, and reflect these values ​​in real time to the control system. Based on this, the opening and closing of the heating device 13 is adjusted to ensure stable internal environmental conditions of the testing device. The gas measurement system 15 detects the gas flow rate permeating from the concrete specimen 7 and the gas state changes within the second cavity 4. After the test, the drain port 6 is used to depressurize the concrete gas permeability testing device and drain any remaining water.

[0040] Traditional gas permeability testing equipment can only study the influence of single factors on the gas permeability of concrete. Furthermore, the specimen size is limited; for example, it can only study the effect of temperature or air pressure on gas permeability, and cannot investigate the gas permeability of concrete coupled with multiple environmental factors. During the experiment, as water vapor liquefies, water droplets form on the surface of the concrete specimen, which inhibits the rate at which gas passes through the concrete surface, thus biasing the test results.

[0041] The concrete gas permeability testing device can provide a precise high temperature, high humidity, and high pressure testing environment, and can conduct gas permeability tests and real-time monitoring of temperature field and moisture distribution on concrete specimen 7 under the coupled effects of different high temperature, high humidity, and high pressure environmental conditions.

[0042] This invention designs a liquid meter 21 to collect water liquefied from water vapor on the upper surface of concrete specimen 7; to allow water droplets to flow out better, the upper surface of concrete specimen 7 is made into a slope with a gradient of 2-8%; the space between concrete specimen 7 and cylinder 1 is filled with high-temperature resistant adhesive, or a sealed space is left between concrete specimen 7 and cylinder wall, which can reduce the accuracy requirements of concrete specimen 7. Large-volume concrete will have dimensional deviations during the pouring and curing process. This concrete gas permeability test device can solve the problem of uneven surface of concrete specimen 7 and greatly reduce the difficulty of the test.

[0043] The specimen fixing system 5 is used to fix the concrete specimen 7, and its length matches the length of the concrete specimen 7.

[0044] The safety protection system includes wire mesh, plexiglass cover, and fuses, which are used to prevent experimental accidents and protect the safe conduct of the experiment.

[0045] The concrete gas permeability test device is enclosed with wire mesh and plexiglass cover to prevent gas leakage during the test and to avoid burning the test personnel with high temperature and high pressure gas inside the cylinder.

[0046] The fuse provides overcurrent protection, preventing the gas temperature in the environmental simulation system 11 from becoming too high. When the temperature exceeds the alarm value, the fuse melts quickly, cutting off the circuit and increasing the safety of the test.

[0047] In some alternative embodiments, the concrete gas permeability testing device includes two implementations: a combined gas permeability testing device or an adjustable environmental condition gas permeability measuring device.

[0048] In some optional embodiments, the detection components of the environmental simulation system 11 include an ambient temperature sensor 16, a humidity sensor 17, and a pressure sensor 18. The ambient temperature sensor 16 is used to detect the temperature value inside the second cavity 4, the humidity sensor 17 is used to detect the humidity value inside the second cavity 4, and the pressure sensor 18 is used to detect the pressure value inside the second cavity 4. The environmental simulation system 11 also includes a ceramic pad 19, and a heating device 13 is disposed on the ceramic pad 19. That is, the ambient temperature sensor 16, humidity sensor 17, and pressure sensor 18 installed in the second cavity 4 are all used to monitor the corresponding indicators inside the cavity and reflect them in real time to the control system, thereby adjusting the opening and closing of the heating device 13 to ensure the stability of the internal environmental conditions of the test device.

[0049] In some optional embodiments, the environmental simulation system 11 further includes a ceramic pad 19 on which the heating device 13 is disposed. This prevents the heating device 13 from directly contacting the heat-insulating coating, which could cause the heat-insulating material to burn.

[0050] In some optional embodiments, the cylinder 1 includes: a first steel cylinder 26 and a second steel cylinder 27 disposed on a fixed frame 2, the first steel cylinder 26 having a first cavity 3 and the second steel cylinder 27 having a second cavity 4; a support structure 10 disposed between the first steel cylinder 26 and the second steel cylinder 27 for supporting the concrete specimen 7; and a heat insulation element 9 disposed on the outer wall of the cylinder 1.

[0051] It also includes a sealing structure located between the first cavity 3 and the second cavity 4, which is used to seal the concrete specimen 7, the first cavity 3 and the second cavity 4.

[0052] The sealing structure includes a sealing gasket 32, a first sealing bolt 33, and a second sealing bolt 34;

[0053] The first steel cylinder 26 is composed of two semi-cylindrical cylinders spliced ​​together. The two semi-cylindrical cylinders are sealed by pressing the sealing gasket 32 ​​between the flanges with the first sealing bolt 33. The first steel cylinder 26 and the second steel cylinder 27 are sealed by pressing the sealing gasket 32 ​​with the second sealing bolt 34.

[0054] Furthermore, the concrete specimen 7 and the first steel cylinder 26 are sealed with a high-temperature resistant adhesive.

[0055] The support structure 10 is a support pad installed on the inner wall of the cylinder 1. The support pad is used to fix the concrete specimen 7 to prevent the concrete specimen 7 from sliding down.

[0056] The support pad has multiple support columns at the bottom to prevent deformation during the test.

[0057] The mounting frame 2 is installed on the ground. The mounting frame 2 has two rings (not shown in the figure) at the top and bottom. The two rings are used to fix the concrete gas permeability test device. The two rings are wrapped with heat insulation parts 9, and the inner wall of the cylinder 1 is coated with a uniform heat insulation coating to prevent the concrete gas permeability test device from exchanging heat with the outside.

[0058] In some optional embodiments, the gas measurement system 15 of the combined gas permeability testing apparatus includes: a temperature and humidity sensor 20 disposed in the first cavity 3; a liquid meter 21 penetrating the cylinder 1 and extending into the first cavity 3, the liquid meter 21 being used to detect the volume of liquid in the first cavity 3; a water tank 22 penetrating the cylinder 1 and extending into the first cavity 3, the water tank 22 being used to detect the end of the first cavity 3 away from the concrete specimen 7; and a metering device 23 connected to the water tank 22.

[0059] The temperature and humidity sensor 20 can reflect the changes in temperature and humidity in the first cavity 3 in real time, while the liquid meter 21 is used to measure the volume of water vapor liquefied into water in the first cavity 3.

[0060] The water tank 22 and the metering device 23 together form a gas permeability testing device, used to determine the gas permeability at the upper end of the concrete specimen 7. The metering device 23 is covered with non-woven fabric to prevent moisture from evaporating and escaping, which could lead to inaccurate test results.

[0061] Gas seeping from the concrete specimen 7 is discharged through the gas outlet 30 and introduced into a specially designed water tank 22. The gas pressure causes water to be discharged into the metering device 23, and the volume of water discharged is the volume of gas discharged. The unheated surface of the concrete specimen 7 is reserved with a slope of 2-8%, so that water on the surface of the concrete specimen 7 is discharged into the liquid metering device 21 through the liquid outlet 31.

[0062] The gas measurement system 15 also includes a timed camera 24, which is used to record the amount of water in the liquid metering device 21 and the metering device 23 at regular intervals. The timed camera 24 is placed on the graduated side of the metering device 23 to take pictures and record the gas and liquid volumes in the gas-liquid permeation test device at regular intervals.

[0063] In some alternative embodiments, the gas measurement system 15 of the adjustable environmental condition gas permeability measuring device includes a gas collection device 35 and a sealing sleeve 36, the gas collection device 35 being fitted onto the top of the concrete specimen 7, and the sealing sleeve 36 being used for the first cavity 3.

[0064] Bolt 37 is provided inside the cylinder 1. Bolt 37 is used to press the upper surface of the concrete specimen 7 down and tighten the concrete specimen 7 so that the concrete specimen 7 is tightly fastened to the support pad. A sealing gasket 32 ​​is provided between the bottom surface of the concrete specimen 7 and the support pad to ensure the sealing between the bottom surface of the specimen and the support pad.

[0065] The gas measurement system 15 consists of a gas collection device 35 and a sealing sleeve 36. The gas collection device 35 is a latex balloon that is placed on top of the concrete specimen 7 to collect the gas that permeates from the environmental simulation system 11 through the concrete specimen 7.

[0066] The sealing sleeve 36 serves two purposes: firstly, to ensure the airtightness between the gas collection device 35 and the concrete specimen 7; secondly, to make the side environment of the concrete specimen 7 a closed space, thereby making it easier to adjust its environmental conditions.

[0067] In some optional embodiments, the concrete gas permeability testing device further includes a safety protection system, which includes a wire mesh, an acrylic glass cover, and a fuse. The wire mesh and acrylic glass cover are placed on the outer periphery of the device to prevent gas leakage during the test and to prevent the high temperature and high pressure gas inside from burning the test personnel. Fuses are installed in the heating device 13 and each circuit.

[0068] By placing the cylinder 1 in the safety protection system, the cylinder 1 can be fixed using the safety protection system, thus ensuring the stability of the cylinder 1 test.

[0069] In some optional embodiments, the combined gas permeability testing apparatus further includes a cooling water circulation system 14 disposed on the outer wall of the cylinder 1, the cooling water circulation system 14 being used to cool the cylinder 1.

[0070] The cooling water circulation system 14 is located at the bottom of the cylinder 1 to cool the cylinder 1 and prevent the temperature of the cylinder 1 from becoming too high, which would affect the test. A gas collection system is used to monitor the flow rate of gas permeating from the test specimen.

[0071] In some optional embodiments, the adjustable environmental condition gas permeability measuring device further includes a circulating gas inlet 28 and a circulating gas outlet 29, which are disposed on the cavity wall of the second cavity 4.

[0072] The circulating gas injection port 28 and the circulating gas discharge port 29 can adjust the environmental conditions on the side of the concrete specimen 7 inside the second cavity 4, so that it is stabilized within a certain temperature range.

[0073] In some alternative embodiments, the sensor group 8 includes a specimen temperature sensor, a resistivity sensor, and a gas pressure sensor, which are staggered within the concrete specimen 7.

[0074] Temperature sensors, resistivity sensors, and gas pressure sensors are pre-embedded at different depths in concrete specimen 7 to measure the temperature, moisture content, and pore pressure at different depths in the specimen. The outputs of the temperature sensors, resistivity sensors, and gas pressure sensors are led out from the side of concrete specimen 7.

[0075] To prevent gas from seeping through the interface between the sensor line and the concrete during the test, 1-5 elliptical materials are placed on the sensor line, and the cross-sectional area is increased.

[0076] The present invention also provides a method for operating the concrete gas permeability testing device, comprising the following steps:

[0077] Apply high-temperature resistant resin to the side of the prepared concrete specimen 7 to ensure the sealing of the side of the concrete specimen 7. After the resin has cured, open the upper steel cylinder that fixes the concrete specimen 7 and divide it into two semi-cylindrical cylinders. Place the semi-cylindrical cylinders on a horizontal ground and apply a heat insulation coating and high-temperature resistant adhesive of appropriate thickness to the surface.

[0078] Then, the concrete specimen 7 is placed inside one of the semi-cylindrical tubes and fixed, and the other semi-cylindrical tube is placed on top of the concrete specimen 7. The device is sealed by tightening the second sealing bolt 34.

[0079] The environmental simulation system 11 is connected to the cylinder 1 by the second sealing bolt 34, and the concrete specimen 7 is fixed on the support pad. After connecting the circuit and turning on the power, check whether the environmental simulation system 11 and the gas measurement system 15 can operate normally. Then, open the gas-liquid injection port 12, connect the nitrogen cylinder, inject nitrogen into the second cavity 4, and confirm whether the airtightness of the device is good by observing the reading of the pressure sensor 18.

[0080] After confirming that the airtightness is good, wrap the heat insulation 9 around the outer wall of the cylinder 1 and install it on the fixing frame 2;

[0081] Add an appropriate amount of liquid into the environmental simulation system 11 through the gas-liquid injection port 12, close the gas-liquid injection port 12, turn on the heating device 13 to heat the water in the second cavity 4, and monitor the gas state changes through the ambient temperature sensor 16, humidity sensor 17, and air pressure sensor 18.

[0082] The cooling water circulation system 14 is turned on to continuously cool the first steel cylinder 26 during the test. After the preset test conditions are reached, the heating device 13 of the environmental simulation system 11 switches from continuous heating to intermittent heating to maintain the stability of the internal environmental conditions of the first steel cylinder 26.

[0083] The data logger is turned on to collect data from the testing mechanism 8 inside the concrete specimen 7. The timed camera 24 is turned on to take photos and record the amount of water in the liquid meter 21 and the metering device 23 at regular intervals. The amount of gas seeping out of the concrete specimen 7 is obtained by the drainage method.

[0084] After all the above steps are completed, observe the test outside the wire mesh and plexiglass cover to avoid any emergencies.

[0085] If the environmental simulation system malfunctions, resulting in excessive gas pressure and temperature inside the second steel cylinder 27, the fuse in the heating device 13 will be damaged, stopping heating. Cooling of the cylinder 1 should be performed according to the actual situation to ensure experimental safety.

[0086] After 72 hours, turn off the heating device 13 and the timer camera 24 to stop data acquisition. Remove the heat insulation 9 from the outside of the cylinder 1 and then cool down the cylinder 1. After the device reaches a suitable temperature, open the drain port 6 to balance the air pressure inside and outside the device and drain excess water.

[0087] Unscrew the first sealing bolt 33 and the second sealing bolt 34, and immediately remove the concrete specimen 7 that has completed the permeability test from the device. Cover it with plastic sheeting to prevent changes in humidity for subsequent test research.

[0088] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. A concrete gas permeability testing device, characterized in that, include: An environmental simulation system (11) is located in the second cavity (4). The environmental simulation system (11) includes a gas-liquid injection port (12), a detection component, and a heating device (13). Liquid and gas enter the second cavity (4) through the gas-liquid injection port (12). The heating device (13) is used to heat the liquid. The detection component is used to detect the temperature, humidity, and pressure values ​​in the second cavity (4). A gas measurement system (15) is installed in the first cavity (3). The gas measurement system (15) is used to measure the volume of gas in the second cavity (4) that permeates into the first cavity (3) through the concrete specimen (7). The specimen fixing system (5) is located between the environmental simulation system (11) and the gas measurement system (15) for fixing the concrete specimen (7). The concrete specimen (7) has a set slope and a sensor group (8) is provided inside the concrete specimen. The detection components of the environmental simulation system (11) include an ambient temperature sensor (16), a humidity sensor (17), and a pressure sensor (18). The ambient temperature sensor (16) is used to detect the temperature value inside the second cavity (4), the humidity sensor (17) is used to detect the humidity value inside the second cavity (4), and the pressure sensor (18) is used to detect the pressure value inside the second cavity (4).

2. The concrete gas permeability testing device according to claim 1, characterized in that, It includes two implementation methods: a combined gas permeability testing device or a gas permeability measurement device with adjustable environmental conditions.

3. The concrete gas permeability testing device according to claim 1, characterized in that, The environmental simulation system (11) also includes a ceramic pad (19), and a heating device (13) is located on the ceramic pad (19).

4. The concrete gas permeability testing device according to claim 1, characterized in that, include: A cylindrical body (1) is mounted on a fixed frame (2). The cylindrical body (1) includes a first steel cylinder (26) and a second steel cylinder (27). The first steel cylinder (26) has a first cavity (3), and the second steel cylinder (27) has a second cavity (4). A support structure (10) is provided between the first steel cylinder (26) and the second steel cylinder (27). The support structure (10) is used to support the concrete specimen (7). A heat insulation component (9) is provided on the outer wall of the cylindrical body (1). A sealing structure is provided between the first cavity (3) and the second cavity (4), and the sealing structure is used to seal the concrete specimen (7), the first cavity (3) and the second cavity (4).

5. The concrete gas permeability testing device according to claim 2, characterized in that, The gas measurement system (15) of the combined gas permeability test device includes: a temperature and humidity sensor (17) located in the first cavity (3); a liquid meter (21) penetrating the cylinder (1) and extending into the first cavity (3), the liquid meter (21) being used to detect the volume of liquid in the first cavity (3); a water tank (22) penetrating the cylinder (1) and extending into the first cavity (3), the water tank (22) being used to detect the end of the first cavity (3) away from the concrete specimen (7); a metering device (23) connected to the water tank (22); the gas measurement system (15) also includes a timed camera (24), the timed camera (24) being used to record the amount of water in the liquid meter (21) and the metering device (23) at regular intervals.

6. The concrete gas permeability testing device according to claim 2, characterized in that, The gas measurement system (15) of the adjustable environmental condition gas permeability measuring device includes a gas collection device (35) and a sealing sleeve (36). The gas collection device (35) is fitted on the top of the concrete specimen (7), and the sealing sleeve (36) is used for the first cavity (3).

7. The concrete gas permeability testing device according to claim 1, characterized in that: The concrete gas permeability test device also includes a safety protection system, which includes a wire mesh, an plexiglass cover and a fuse. The wire mesh and plexiglass cover are set on the outer periphery of the device to prevent gas leakage during the test and to prevent the high temperature and high pressure gas inside from burning the test personnel. The heating device (13) and each circuit are equipped with fuses.

8. The concrete gas permeability testing device according to claim 2, characterized in that, The combined gas permeability test device also includes a cooling water circulation system (14), which is located on the outer wall of the cylinder (1) and is used to cool the cylinder (1).

9. The concrete gas permeability testing device according to claim 2, characterized in that, The adjustable environmental condition gas permeability measuring device also includes a circulating gas inlet (28) and a circulating gas outlet (29), which are located on the cavity wall of the second cavity (4).

10. The concrete gas permeability testing device according to claim 1, characterized in that, The sensor group (8) includes a specimen temperature sensor, a resistivity sensor, and a gas pressure sensor, which are staggered inside the concrete specimen.

Images