A testing device for the air content of concrete under constant temperature and humidity

Abstract

The present invention provides a test device for the air content of concrete under constant temperature and humidity, which relates to the field of testing the air content of concrete. The test device for the air content of concrete under constant temperature and humidity includes a bowl body and a bowl cover. A constant temperature chamber, a cavity and a pressurization chamber are arranged inside the bowl body. A rotating cylinder for storing concrete is rotatably installed on the inner side of the bowl body. An air inlet and an air outlet are formed in the cavity, and an opening is arranged inside the rotating cylinder. For the test device for the air content of concrete under constant temperature and humidity, chambers of different levels can independently and precisely control and adjust different pressure ranges. The chamber with the highest pressure can preliminarily measure and balance larger bubbles, and the chambers with lower pressures respectively measure medium-sized and tiny bubbles. This hierarchical measurement method can capture the pressure changes generated by bubbles of different sizes more accurately. Compared with a single air pump for switching pressures, it can measure the air content in concrete more accurately.

Description

Technical Field

[0001] The present invention relates to the field of measuring the air content of concrete, and specifically to a test device for the air content of concrete under constant temperature and humidity. Background Art

[0002] The measurement of the air content of concrete is a technical means for determining the percentage of the volume of gas contained in concrete in the total volume of concrete, and plays an important role in the quality control and performance research of concrete. The air content in concrete has a significant impact on its frost resistance. An appropriate air content can form tiny closed bubbles inside the concrete. During the freeze-thaw cycle, it provides space for the ice expansion of water, relieves internal stress, and improves frost resistance. Through the air content test, it can be ensured that concrete has sufficient durability in harsh environments, such as hydraulic structures, road bridges, etc. in cold regions. Hydraulic structures such as dams, canals, and ports are in a water environment for a long time and are strongly affected by the freeze-thaw cycle. They have strict requirements for the air content of concrete and need to measure the air content to ensure the impermeability and frost resistance of the structure. At present, the commonly used method for measuring the air content of concrete is the air pressure method, that is, using a concrete air content tester. The concrete mixture is loaded into the container of the air content tester, and by applying air pressure, the pressure in the container reaches a certain value, and then the air content of the concrete is calculated according to the pressure change and relevant formulas. This method is relatively simple to operate and is suitable for construction sites and laboratories.

[0003] At present, the traditional concrete air content test widely adopts the method of loading the concrete mixture into the container of the air content tester in three layers. Each layer is evenly tamped with a tamping rod a certain number of times to achieve the compaction of the concrete. After the last layer is tamped, the surface is leveled with a trowel. However, the size distribution range of air bubbles inside the concrete is extremely wide, covering various types from larger-sized bubbles to tiny bubbles.

[0004] The commonly used air pressure method for the test device of concrete air content to measure the air content can measure more accurately when facing larger bubbles because the influence of larger bubbles on the pressure change is significant and easy to be detected. However, when facing tiny bubbles, due to the weak influence of tiny bubbles on the pressure change, it is difficult to accurately capture this subtle change, resulting in the inability to accurately measure in some scenarios with high precision requirements for the measurement of the content of tiny bubbles. Furthermore, it affects the evaluation of the true air content of the concrete, leading to deviations in the accurate judgment of the concrete performance and being unfavorable to the precise control of the concrete quality. Therefore, there is an urgent need for a device that can effectively solve the problem of measuring tiny bubbles and more accurately measure the air content of concrete. Summary of the Invention

[0005] Aiming at the deficiencies of the prior art, the present invention provides a test device for the air content of concrete under constant temperature and humidity, which solves the problem of inaccurate measurement of tiny bubbles.

[0006] To achieve the above object, the present invention is realized through the following technical solutions: A test device for the air content of concrete under constant temperature and humidity, comprising a bowl body and a bowl cover. A constant temperature chamber, a cavity, and a pressurizing chamber are provided inside the bowl body. A rotating cylinder for storing concrete is rotatably installed on the inner side of the bowl body. An air inlet and an air outlet are provided in the cavity. An opening is provided inside the rotating cylinder. The pressurizing chamber includes chambers with gradually increasing air pressure. Each chamber is provided with an exhaust port for delivering gas to the opening. Both ends of the rotating cylinder are fixedly connected with turntables. A rotating rod for rotation is installed between the two turntables. A transmission mechanism is installed on the outer side of the rotating rod.

[0007] An assembled pad in a star shape is provided inside the rotating cylinder. The assembled pad includes a number of arc pads A, a number of arc pads B, and a number of inclined pads. The arc pads A are in contact with the rotating cylinder. A support rod is fixedly connected to the arc surface of each arc pad A close to the rotating rod. When the rotating rod rotates, the support rod is controlled to move through the transmission mechanism. A push rod is fixedly connected to the arc surface of each arc pad B away from the rotating rod. The push rod presses the arc pad B towards the rotating rod through a spring assembly.

[0008] Preferably, an air inlet pipe B for delivering warm air to the constant temperature chamber is communicated with the outside of the constant temperature chamber. A valve is installed at one end of the air inlet pipe B.

[0009] Preferably, an air inlet pipe A is communicated with the outside of each chamber. A valve is installed at one end of each air inlet pipe A.

[0010] Preferably, a driving motor A is installed inside one of the turntables. The output end of the driving motor A is fixedly connected to the rotating rod. One end of the other turntable is connected to an external motor.

[0011] Preferably, the transmission mechanism includes a runner, a guiding wheel for rotation, a number of fixed columns, and a number of push-pull plates. The runner is fixedly connected to the rotating rod. A number of sliding grooves are provided inside the runner. Each push-pull plate is slidably connected to the sliding groove close to it and is fixedly connected to the support rod close to it. The guiding wheel is rotatably connected to the rotating rod. A number of arc grooves are provided inside the guiding wheel. Each fixed column is slidably connected to the arc groove close to it and is fixedly connected to the push-pull plate close to it.

[0012] Preferably, a mounting plate is fixedly connected to the outer side of the rotating rod. A driving motor B is fixedly installed on one side of the mounting plate. The output end of the driving motor B is fixed to a gear B. A gear A is rotatably connected to the outer side of the rotating rod. The gear A is fixedly connected to one of the guiding wheels. The outer surface of the gear A is meshed with the gear B. The output end of the driving motor B is fixedly connected to the gear B.

[0013] Preferably, a feed hopper is fixedly connected inside the cavity. A sealing cover is provided at the inlet of the feed hopper. When the opening moves to a position corresponding to the feed hopper, it is used to convey concrete into the opening.

[0014] Preferably, the upper surface and the bottom surface of the combined pad are in close contact with the two turntables respectively.

[0015] Preferably, both the arc-shaped pad A and the arc-shaped pad B are made of silica gel material, and the inclined pad is made of rubber material.

[0016] Preferably, the spring assembly includes a spring, a plug rod, a fixed cylinder and a fixing plate. The fixed cylinder is slidably connected to the inner wall of the rotating cylinder. An arc-shaped piece is installed on the outside of the fixed cylinder, and the arc-shaped piece is slidably connected to the rotating cylinder. The plug rod is slidably connected to the fixed cylinder, and the intersection of the two is sealed. The other end of the plug rod is fixedly connected to the push rod close to it. The fixing plate is fixedly connected to the plug rod. The two ends of the spring are respectively fixedly connected to the fixed cylinder and the fixing plate, and the spring is in a compressed state.

[0017] Compared with the prior art, the present invention has the following beneficial effects:

[0018] 1. For the test device of the air content of concrete under constant temperature and humidity, by applying gradually increasing air pressures to the three chambers through three air inlet pipes A respectively, different levels of chambers can independently and precisely control and adjust different pressure ranges. The chamber with the highest pressure can preliminarily measure and balance larger bubbles, and the chambers with lower pressures respectively measure medium-sized and tiny bubbles. This hierarchical measurement method can capture the pressure changes generated by bubbles of different sizes more accurately. Compared with a single air pump for switching pressures, it can measure the air content in concrete more accurately. The multi-stage chamber structure forms a relatively stable pressure environment in each chamber, and each chamber has an independent pressure regulation and balancing system. When the air pump provides pressure for the next-level chamber, the pressure of the upper-level chamber is not disturbed, thereby reducing the influence of pressure fluctuations on the measurement results and improving the accuracy and reliability of the measurement.

[0019] 2. The test device for the air content of concrete under constant temperature and humidity. The runner, guide wheel, and rotating cylinder can all rotate independently or work together. Their respective rotation controls are achieved through different drive motors and transmission mechanisms, providing multiple operation modes for the test of the air content of concrete. For example, the rotation of the runner can control the rotation of the combined pad to achieve the feeding and mixing of concrete; the rotation of the guide wheel can adjust the distance between the combined pad and the rotating cylinder to enable the concrete to circulate or be separated from each other; the rotation of the rotating cylinder facilitates the feeding of concrete and the test docking of different chambers. This flexible design meets the requirements of different stages during the test process. The combination of multiple rotation methods avoids complex manual operations and improves the automation level of the test process. The operator only needs to control different drive motors to complete a series of operations such as loading, mixing, compaction, and testing of concrete, reducing the errors and uncertainties that may be brought by manual intervention.

[0020] 3. The test device for the air content of concrete under constant temperature and humidity. By rotating the rotating cylinder to align the opening with the feed hopper, concrete is put into the rotating cylinder. Then, the runner drives the combined pad to rotate, enabling the concrete to sequentially enter several sealed spaces formed between the combined pad and the rotating cylinder, achieving uniform feeding. This uniform loading method avoids the problems of concrete accumulation or uneven distribution in the rotating cylinder, laying a foundation for accurately measuring the air content subsequently. The star-shaped structure of the combined pad can stir the concrete during rotation, making the air bubbles in the concrete evenly distributed. At the same time, by adjusting the distance between the combined pad and the rotating cylinder through the guide wheel, the concrete circulates and then is separated, further promoting the uniform dispersion of air bubbles, which helps to improve the accuracy of the air content test. The inclined pad of the combined pad is made of rubber material, which can squeeze the concrete and compact it when returning to its original position. This process does not require manual ramming, avoiding the problem of uneven air bubble distribution caused by excessive or insufficient manual ramming, ensuring the consistency of the internal structure of the concrete, and thus enabling the measured air content to more truly reflect the actual situation of the concrete. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 is a schematic diagram of the overall structure of the present invention;

[0022] Figure 2 is a cross-sectional view of the front view of the bowl body of the present invention;

[0023] Figure 3 is a cross-sectional view of the top view of the bowl body of the present invention;

[0024] Figure 4 is a cross-sectional view of the top views of the bowl body and the rotating cylinder of the present invention;

[0025] Figure 5 is of the present invention Figure 4 magnified schematic diagram of the structure at A in;

[0026] Figure 6Cross-sectional view of the top view of the combined pad of the present invention;

[0027] Figure 7 Cross-sectional view of the top view of the rotating rod of the present invention;

[0028] Figure 8 Cross-sectional view of the top view of the runner of the present invention;

[0029] Figure 9 Cross-sectional view of the bottom view of the pot body of the present invention;

[0030] Figure 10 Schematic structural diagram of the support rod of the present invention.

[0031] Wherein: 1, pot body; 2, pot cover; 3, constant temperature chamber; 4, cavity; 5, pressure increasing chamber; 6, rotating cylinder; 7, air inlet; 8, air outlet; 9, opening; 10, chamber; 11, exhaust port; 12, turntable; 13, rotating rod; 14, combined pad; 141, arc pad A; 142, arc pad B; 143, inclined pad; 15, support rod; 16, push rod; 17, intake pipe B; 18, intake pipe A; 19, drive motor A; 20, runner; 21, guide wheel; 22, fixed column; 23, push-pull plate; 24, arc groove; 25, mounting plate; 26, gear B; 27, feed hopper; 28, inserting rod; 29, fixed cylinder; 30, fixing plate; 31, arc piece. Detailed implementation mode

[0032] As Figures 1 - 10As shown in the figure, a test device for the air content of concrete under constant temperature and humidity includes a bowl body 1 and a bowl cover 2. The bowl body 1 and the bowl cover 2 are sealed and installed. Inside the bowl body 1, there are a constant temperature chamber 3, a cavity 4, and a pressurization chamber 5. An air inlet pipe B17 for delivering warm air to the constant temperature chamber 3 is connected to the outside of the constant temperature chamber 3. One end of the air inlet pipe B17 is equipped with a valve. The warm air is delivered into the constant temperature chamber 3 through the air inlet pipe B17 to provide a constant temperature environment for the concrete. A feed hopper 27 is fixedly connected inside the cavity 4. A sealing cover is provided at the inlet of the feed hopper 27. When the opening 9 moves to a position corresponding to the feed hopper 27, it is used to convey the concrete into the opening 9. A rotating drum 6 for storing the concrete is rotatably installed on the inner side of the bowl body 1. The rotating drum 6 is in close contact with the bowl body 1. An air inlet 7 and an air outlet 8 are opened inside the cavity 4. An opening 9 is provided inside the rotating drum 6. The pressurization chamber 5 includes chambers 10 with gradually increasing air pressure. An air inlet pipe A18 is connected to the outside of each chamber 10. A valve is installed at one end of each air inlet pipe A18. An exhaust port 11 for delivering gas to the opening 9 is provided in each chamber 10. Both ends of the rotating drum 6 are fixedly connected with turntables 12. A driving motor A19 is installed inside one of the turntables 12. The output end of the driving motor A19 is fixedly connected to a rotating rod 13. One end of the other turntable 12 is connected to an external motor. The driving motor A19 is used to drive the rotating rod 13 to rotate, and the external motor is used to drive the turntable 12 to rotate. A rotating rod 13 for rotation is installed between the two turntables 12. A transmission mechanism is installed on the outer side of the rotating rod 13. The number of transmission mechanisms is two, and the two transmission mechanisms are respectively located at both ends of the rotating rod 13. The transmission mechanism includes a runner 20, a guiding wheel 21 for rotation, a number of fixing columns 22, and a number of push-pull plates 23. The runner 20 is fixedly connected to the rotating rod 13. A number of sliding grooves are provided inside the runner 20. Each push-pull plate 23 is slidably connected to the sliding groove close to it and is fixedly connected to the supporting rod 15 close to it. The guiding wheel 21 is rotatably connected to the rotating rod 13. A number of arc-shaped grooves 24 are provided inside the guiding wheel 21. Each fixing column 22 is slidably connected to the arc-shaped groove 24 close to it and is fixedly connected to the push-pull plate 23 close to it. When the guiding wheel 21 rotates, it can push the fixing column 22 to move through the arc-shaped groove 24, so that the push-pull plate 23 drives the supporting rod 15 to move. An installation plate 25 is fixedly connected to the outer side of the rotating rod 13. A driving motor B is fixedly installed on one side of the installation plate 25. The output end of the driving motor B is fixed to a gear B26. A gear A is rotatably connected to the outer side of the rotating rod 13. The gear A is fixedly connected to one of the guiding wheels 21. The outer surface of the gear A is meshed with the gear B26. The output end of the driving motor B is fixedly connected to the gear B26.

[0033] Inside the rotary drum 6, there is a combined gasket 14 in a star shape. The upper surface and the bottom surface of the combined gasket 14 are in close contact with the two turntables 12 respectively, forming a sealed space. The combined gasket 14 includes a number of arc-shaped gaskets A141, a number of arc-shaped gaskets B142 and a number of inclined gaskets 143. The arc-shaped gasket A141 is in contact with the rotary drum 6. Both the arc-shaped gasket A141 and the arc-shaped gasket B142 are made of silica gel material, and the inclined gasket 143 is made of rubber material. A support rod 15 is fixedly connected to the arc surface of each arc-shaped gasket A141 near the rotating rod 13. When the rotating rod 13 rotates, the movement of the support rod 15 is controlled by a transmission mechanism. A push rod 16 is fixedly connected to the arc surface of each arc-shaped gasket B142 away from the rotating rod 13. The push rod 16 presses the arc-shaped gasket B142 towards the direction close to the rotating rod 13 through a spring assembly. The spring assembly includes a spring, a plug rod 28, a fixed cylinder 29 and a fixing plate 30. The fixed cylinder 29 is slidably connected to the inner wall of the rotary drum 6. An arc-shaped piece 31 is installed on the outer side of the fixed cylinder 29. The arc-shaped piece 31 is slidably connected to the rotary drum 6. The plug rod 28 is slidably connected to the fixed cylinder 29, and the intersection of the two is sealed. The other end of the plug rod 28 is fixedly connected to the push rod 16 close to it. The fixing plate 30 is fixedly connected to the plug rod 28. The two ends of the spring are fixedly connected to the fixed cylinder 29 and the fixing plate 30 respectively. The spring is in a compressed state.

[0034] Working principle:

[0035] First of all, it should be noted that the runner 20, the guide wheel 21 and the rotary drum 6 can all rotate independently. When the runner 20 needs to rotate, the rotating rod 13 is driven to rotate by the driving motor A19. The rotating rod 13 is fixed to the runner 20. Therefore, the rotating rod 13 can drive the runner 20 to rotate. When the runner 20 rotates, it is used to control the rotation of the combined gasket 14. This is because the runner 20 can drive a number of push-pull plates 23 to rotate. The push-pull plates 23 drive the support rods 15 to rotate. The combined gasket 14 is driven to rotate through the support rods 15. When the combined gasket 14 rotates, it can also drive the spring assembly to rotate. When the guide wheel 21 needs to rotate, the gear A is driven to rotate by the driving motor B. The gear A drives the gear B26 to rotate. The gear B26 drives the guide wheel 21 to rotate. The arc-shaped groove 24 inside the guide wheel 21 can push the fixed column 22 to move. The fixed column 22 drives the push-pull plate 23 to move. Since the push-pull plate 23 is slidably connected to the chute inside the runner 20, when the position of the runner 20 remains unchanged, the push-pull plate 23 can drive the support rod 15 to move towards the direction close to the rotating rod 13. When the rotary drum 6 needs to rotate, one of the turntables 12 is connected to an external motor, and the rotary drum 6 is driven to rotate through the external motor. The turntable 12 is fixed to the rotary drum 6. Therefore, the rotation of the rotary drum 6 can be realized. The runner 20, the guide wheel 21 and the rotary drum 6 can also work together, laying a foundation for the subsequent test work of the air content of concrete.

[0036] Next, by rotating the rotary drum 6, the opening 9 of the rotary drum 6 is rotated to a position corresponding to the feed hopper 27, and then the concrete to be tested is put into the feed hopper 27. The concrete in the feed hopper 27 enters the opening 9 and then enters the rotary drum 6. At this time, a number of arc-shaped pads A141 of the combined pad 14 should be in contact with the inner wall of the rotary drum 6, and a number of sealed spaces are formed between the combined pad 14 and the rotary drum 6. The concrete in the opening 9 enters a space close to it, and then by controlling the rotation of the runner 20, the combined pad 14 can be rotated. During the uniform rotation of the combined pad 14, the concrete in the opening 9 enters a number of spaces in turn, making the feeding between the combined pad 14 and the rotary drum 6 more uniform; since the rotating rod 13 is connected to the driving motor A19, the rotation of the rotating rod 13 can be restricted by the driving motor A19, and then the position of the rotating rod 13 needs to be fixed by the restriction of the driving motor A19. The rotating rod 13 is fixed to the runner 20, so the position of the runner 20 can be fixed. Then, the driving motor B drives the gear A to rotate, the gear A drives the gear B26 to rotate, the gear B26 drives the guide wheel 21 to rotate, and the arc-shaped groove 24 inside the guide wheel 21 can push the fixed column 22 to move. The fixed column 22 drives the push-pull plate 23 to move. Since the push-pull plate 23 is slidably connected to the chute inside the runner 20 and the position of the runner 20 remains unchanged, the push-pull plate 23 can drive the support rod 15 to move towards the direction close to the rotating rod 13. At this time, a gap is generated between the arc-shaped pad A141 of the combined pad 14 and the rotary drum 6. This gap enables the concrete in each space to flow through each other. It should be noted that due to the elastic force of the spring, a thrust will be exerted on the insertion rod 28, so that the push rod 16 continuously presses against the arc-shaped pad B142 of the combined pad 14, enabling the combined pad 14 to maintain a stable star-shaped structure. Then, by rotating the runner 20, the combined pad 14 is rotated. The star-shaped structure of the combined pad 14 can stir the concrete, making the air bubbles in the concrete evenly distributed, which helps to improve the measurement of the air content in the concrete. After stirring, the combined pad 14 is returned to its original position again. At this time, the combined pad 14 separates the concrete into a number of sealed spaces. Moreover, the inclined pad 143 of the combined pad 14 will squeeze the concrete and compact it. It should be noted that the inclined pad 143 of the combined pad 14 is made of rubber material, which can not only enable the whole combined pad 14 to shrink, but also rely on its certain hardness to compact the concrete, and the worker does not need to perform the ramming work to compact the concrete. Since the uniformity of concrete loading and the degree of ramming have a great influence on the measurement results, if the loading is uneven, or the ramming is excessive or insufficient, the air bubble distribution inside the concrete will be uneven, resulting in the measured air content not being able to truly reflect the actual air content of the concrete. For example, excessive ramming may cause some air bubbles to be squeezed out, resulting in a lower measured value; insufficient ramming may cause larger pores to exist inside the concrete, resulting in a higher measured value.

[0037] Subsequently, successively increasing air pressures are applied to the three chambers 10 through the three air inlet pipes A18 respectively. Then, the rotating cylinder 6 is rotated so that the opening 9 in the rotating cylinder 6 faces the chamber 10 with the lowest air pressure. The gas in the chamber 10 enters the space between the combined gasket 14 and the rotating cylinder 6. As the combined gasket 14 rotates, pressure is applied to the concrete at different positions. Since the concrete is separated into multiple spaces, the detection accuracy of the concrete can be improved. Then, in accordance with the above operations, the opening 9 in the rotating cylinder 6 is successively oriented towards the remaining two chambers 10. It should be noted that the air pressure should increase successively. It should be explained that chambers of different levels can independently perform precise control and adjustment for different pressure ranges. For example, the chamber 10 with the highest pressure can, under a relatively high pressure, preliminarily measure and balance the larger air bubbles in the concrete, causing most of the larger air bubbles to be released and participate in the pressure balance. One of the chambers 10 can, at a lower pressure, more specifically measure the influence of medium-sized air bubbles on the pressure. The chamber 10 can, at an even lower pressure, specifically measure the minute air bubbles. This hierarchical measurement method can more precisely capture the pressure changes generated by air bubbles of different sizes. Compared with a simple switching of three pressures by a single air pump, it can more accurately measure the air content in the concrete. During the measurement process, pressure fluctuations may occur when the air pump switches pressures. However, the multi-stage chamber structure can form a relatively stable pressure environment in each chamber. Each chamber has an independent pressure regulation and balance system. When the air pump provides pressure for the next-level chamber, the pressure in the previous-level chamber will not be disturbed, thereby reducing the influence of pressure fluctuations on the measurement results and improving the measurement accuracy.

[0038] Although the embodiments of the present invention have been shown and described, it will be understood by those of ordinary skill in the art that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A device for testing the air content of concrete under constant temperature and humidity, comprising a bowl body (1) and a bowl cover (2), characterized in that: The bowl body (1) is provided with a constant temperature chamber (3), a cavity (4) and a pressurizing chamber (5). A rotating drum (6) for storing concrete is rotatably mounted on the inner side of the bowl body (1). An air inlet (7) and an air outlet (8) are provided in the cavity (4). An opening (9) is provided inside the rotating drum (6). The pressurizing chamber (5) includes chambers (10) with successively increasing air pressures. Each chamber (10) is provided with an exhaust port (11) for conveying gas to the opening (9). Both ends of the rotating drum (6) are fixedly connected with a rotating disk (12). A rotating rod (13) for rotating is installed between the two rotating disks (12). A transmission mechanism is installed on the outer side of the rotating rod (13). The transmission mechanism comprises a rotating wheel (20), a guide wheel (21) for rotation, a plurality of fixed columns (22) and a plurality of push-pull plates (23); the rotating wheel (20) is fixedly connected to the rotating rod (13); a plurality of slide grooves are arranged inside the rotating wheel (20); each push-pull plate (23) is slidably connected to a slide groove adjacent to it and is fixedly connected to a support rod (15) adjacent to it; the guide wheel (21) is rotatably connected to the rotating rod (13); a plurality of arc grooves (24) are arranged inside the guide wheel (21); each fixed column (22) is slidably connected to a arc groove (24) adjacent to it and is fixedly connected to a push-pull plate (23) adjacent to it; A star-shaped combined pad (14) is provided inside the rotating drum (6). The upper surface and the bottom surface of the combined pad (14) are in close contact with the two rotating disks (12) respectively. The combined pad (14) comprises a plurality of arc pads A (141), a plurality of arc pads B (142) and a plurality of inclined pads (143). The arc pads A (141) are in contact with the rotating drum (6). A support rod (15) is fixedly connected to the arc surface of each arc pad A (141) close to the rotating rod (13). When the rotating rod (13) rotates, the support rod (15) is controlled to move by a transmission mechanism. A push rod (16) is fixedly connected to the arc surface of each arc pad B (142) away from the rotating rod (13). The push rod (16) presses the arc pad B (142) in a direction close to the rotating rod (13) through a spring assembly.

2. The device for testing the air content of concrete under constant temperature and humidity according to claim 1, characterized in that: The outside of the constant temperature chamber (3) is connected to an air inlet pipe B (17) for supplying warm air to the constant temperature chamber (3), and a valve is installed at one end of the air inlet pipe B (17).

3. The device for testing the air content of concrete under constant temperature and humidity according to claim 1, characterized in that: The outside of each chamber (10) is connected to an air intake pipe A (18), and a valve is installed at one end of each air intake pipe A (18).

4. The device for testing the air content of concrete under constant temperature and humidity according to claim 1, characterized in that: A driving motor A (19) is installed inside one of the rotating disks (12), and an output end of the driving motor A (19) is fixedly connected to the rotating rod (13). One end of the other rotating disk (12) is connected to an external motor.

5. The device for testing the air content of concrete under constant temperature and humidity according to claim 1, characterized in that: The outer side of the rotating rod (13) is fixedly connected to a mounting plate (25), a driving motor B is fixedly mounted on one side of the mounting plate (25), an output end of the driving motor B is fixed to a gear B (26), a gear A is rotatably connected to the outer side of the rotating rod (13), gear A is fixedly connected to one of the guide wheels (21), an outer surface of the gear A is meshingly connected to the gear B (26), and the output end of the driving motor B is fixedly connected to the gear B (26).

6. The device for testing the air content of concrete under constant temperature and humidity according to claim 1, characterized in that: A feed hopper (27) is fixedly connected to the cavity (4), and a sealing cover is provided at the inlet of the feed hopper (27). When the opening (9) moves to a position corresponding to the feed hopper (27), concrete is transported into the opening (9).

7. The device for testing the air content of concrete under constant temperature and humidity according to claim 1, characterized in that: The arc pad A (141) and the arc pad B (142) are both made of silicone material, and the tilt pad (143) is made of rubber material.

8. The device for testing the air content of concrete under constant temperature and humidity according to claim 1, characterized in that: The spring assembly comprises a spring, an insert rod (28), a fixed cylinder (29) and a fixed plate (30); the fixed cylinder (29) is slidably connected to the inner wall of the rotating cylinder (6); an arc-shaped sheet (31) is installed on the outer side of the fixed cylinder (29); the arc-shaped sheet (31) is slidably connected to the rotating cylinder (6); the insert rod (28) is slidably connected to the fixed cylinder (29); a sealing is arranged at the intersection of the two; the other end of the insert rod (28) is fixedly connected to a push rod (16) adjacent to the insert rod (28); the fixed plate (30) is fixedly connected to the insert rod (28); the two ends of the spring are respectively fixedly connected to the fixed cylinder (29) and the fixed plate (30); and the spring is in a compressed state.

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