A device and method for measuring temperature and humidity of concrete under constant axial tension
By designing the lever principle and the concrete temperature and humidity measurement device of the temperature and humidity probe, the problem of difficult to measure the temperature and humidity of concrete under constant axial tension in the prior art is solved, and the accurate prediction of early cracking of concrete is achieved.
Patent Information
- Application Number
- CN202110291458.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2021-03-18
- Publication Date
- 2024-12-13
- Estimated Expiration
- 2041-03-18
AI Technical Summary
The prior art is difficult to effectively measure the temperature and humidity changes of concrete under constant axial tension, which leads to the inability to accurately predict the occurrence of early cracks in concrete.
A concrete temperature and humidity measurement device using the lever principle is designed, including a loading frame and a temperature and humidity probe. The temperature and humidity measurement under constant axial tension is achieved through the lever and the Z-shaped transmission device, and the concrete is connected by the embedded parts and the ball hinge. The test piece is adjusted by stress sensor and the loading capacity is monitored in combination with the temperature and humidity data collector.
Accurate measurement of the temperature and humidity changes of concrete specimens under tensile stress state is achieved, the impact of the vertical self-weight of concrete is reduced, and important basis for predicting early cracking is provided through continuous monitoring.
Smart Images
Figure CN113063671B_ABST
Abstract
Description
Technical Field
[0001] The invention belongs to the field of concrete temperature and humidity measurement, and in particular relates to a device and method for measuring concrete temperature and humidity under constant axial tension. Background Art
[0002] In the early stage of concrete pouring, cement hydration will cause drastic changes in temperature and humidity. Concrete will experience large temperature deformation and shrinkage deformation in the early stage. The tensile strength of early concrete is low. Once the tensile stress generated by the deformation under internal and external constraints exceeds the tensile strength, the concrete will crack, affecting the durability and other service performance of the concrete structure. Therefore, the temperature and humidity changes inside the concrete are important indicators for predicting early cracking. A large number of experimental studies on the temperature and humidity of concrete have been carried out at home and abroad, but these experiments are conducted on concrete in a free state. The existing technology (a method for measuring the temperature and humidity of concrete specimens under constant axial compression load, patent number: ZL201711053941.1) realizes the measurement of the temperature and humidity of concrete under compressive stress state, but the main cause of concrete cracking is tensile stress rather than compressive stress. Therefore, studying the changes in temperature and humidity inside concrete under tensile stress state can provide an important basis for more accurate prediction of early cracking of concrete. Summary of the invention
[0003] The technical problem to be solved by the present invention is to address the shortcomings of the background technology and provide a device and method for measuring the temperature and humidity of concrete under constant axial tension. The present invention utilizes the principle of lever and uses the simple temperature and humidity measuring device provided by this patent to measure the temperature and humidity changes of concrete specimens under tensile stress state.
[0004] The present invention adopts the following technical solutions to solve the above technical problems:
[0005] A device for measuring temperature and humidity of concrete under constant axial tension comprises a loading frame, the loading frame comprises a first column and a second column, a lever is hinged on the upper end of the first column, the lever comprises a forearm and a rear arm, the length of the forearm is smaller than the length of the rear arm, a Z-shaped transmission device is hinged on one side wall of the column, one end of the Z-shaped transmission device is connected to the end of the forearm through a pull rod one, and the other end is connected to a ball joint through the pull rod one, and a ball joint is arranged through the pull rod two at the same height of the side wall of the second column located at a pulley; a stress sensor is arranged on the pull rod one; a crossbeam for placing concrete specimens is arranged between the first column and the second column; the rear arm is located directly above the second column, and a hanging weight rod is connected to its end, and a plurality of counterweights are arranged under the hanging weight rod; it also comprises a plurality of temperature and humidity probes and a temperature and humidity data collector connected to the temperature and humidity probes.
[0006] Furthermore, an adjusting weight is slidably arranged on the lever.
[0007] Furthermore, bases are provided at the bottoms of the first column and the second column.
[0008] Furthermore, a safety wheel frame for limiting the position of the lever is provided at the upper end of the second column.
[0009] Furthermore, a polytetrafluoroethylene plate is provided on the crossbeam, and oil is applied between the polytetrafluoroethylene plate and the crossbeam, and between the polytetrafluoroethylene plate and the concrete specimen.
[0010] A method for measuring the temperature and humidity of concrete under constant axial tension using a measuring device, comprising the following steps:
[0011] Step 1, preparing a concrete specimen and embedding embedded parts at both ends of the concrete specimen along the pulling direction;
[0012] Step 2: Place the concrete specimen on the polytetrafluoroethylene plate according to the pulling direction, and connect the embedded parts at both ends of the concrete specimen with two ball joints;
[0013] Step 3: bury the temperature and humidity probe in the concrete specimen;
[0014] Step 4: Place the counterweight on the weight hanging rod for loading, and control the weight of the configured weight and adjust the loading force by observing the stress sensor;
[0015] Step 5: After loading is completed, the ball joint is removed and the concrete specimen is placed in the curing room for curing. The temperature and humidity monitoring system continuously monitors the state of the concrete.
[0016] Furthermore, in step 4, the loading force can be further accurately adjusted by sliding the adjustment weight.
[0017] Compared with the prior art, the present invention adopts the above technical solution and has the following technical effects:
[0018] By using the lever principle, a simple device can be used to measure the temperature and humidity changes of concrete specimens under tensile stress. In addition, placing the concrete specimens horizontally can reduce the influence of the vertical deadweight of the concrete, and using embedded parts can avoid considering the shape of the concrete parts. BRIEF DESCRIPTION OF THE DRAWINGS
[0019] Figure 1 It is a schematic diagram of the overall structure of this embodiment.
[0020] In the figure, 1. counterweight; 2. hanging weight rod; 3. safety wheel frame; 4. lever; 41. front arm; 42. rear arm; 5. adjustment weight; 6. pull rod 1; 7. stress sensor; 8. ball joint; 9. concrete specimen; 10. temperature and humidity probe; 11. crossbeam; 12. column 1; 13. column 2; 14. base; 15. temperature and humidity data collector; 16. Z-shaped transmission device; 171. embedded parts; 18. polytetrafluoroethylene plate; 19. hanging foot; 20. pull rod 2. DETAILED DESCRIPTION
[0021] The technical solution of the present invention is further described in detail below in conjunction with the accompanying drawings:
[0022] A device for measuring temperature and humidity of concrete under constant axial tension, such as Figure 1 As shown, the loading frame includes a column 12 and a column 2 13. The upper end of the column 12 is hinged with a lever 4, and the lever 4 includes a front arm 41 and a rear arm 42. The length of the front arm 41 is much smaller than the length of the rear arm 42. A Z-shaped transmission device 16 is hinged on the side wall of the column 12. One end of the Z-shaped transmission device 16 is connected to the end of the front arm 41 through a pull rod 16, and the other end is connected to a ball joint 8 through the pull rod 16. The side wall of the column 2 12 is located at the same height as the pulley 16 and is also provided with a ball joint 8 through the pull rod 20; a space for the column 12 and the column 2 13 is provided between the column 12 and the column 2. The crossbeam 11 on which the concrete specimen is placed; the embedded parts 171 extending from both sides of the concrete specimen placed on the crossbeam 11 are connected to the column 12 and the column 2 13 respectively by means of the ball joint 8 and the tie rod 1 6, wherein a stress sensor 7 is arranged between the Z-shaped transmission device 16 and the ball joint 8, and hanging feet 19 are arranged under the tie rod 1 6 on both sides of the stress sensor 7; the rear arm 42 is located directly above the column 2 13, and a hanging weight rod 2 is connected to its end, and a number of counterweights are arranged under the hanging weight rod 2; 1 also includes a number of temperature and humidity probes 10 and a temperature and humidity data collector 15 connected to the temperature and humidity probes 10. The lever 4 is slidably provided with an adjustment weight 5. The bottom of the column 12 and the column 2 13 is provided with a base 14. A safety wheel frame 3 for limiting the lever 4 is arranged at the upper end of the second column 13, and a polytetrafluoroethylene plate 18 is arranged on the cross beam 11, and oil is coated between the polytetrafluoroethylene plate 18 and the cross beam 11, and between the polytetrafluoroethylene plate 18 and the concrete specimen 9.
[0023] A method for measuring the temperature and humidity of concrete under constant axial tension using a measuring device comprises the following steps:
[0024] Step 1, preparing a concrete specimen and embedding embedded parts at both ends of the concrete specimen along the pulling direction;
[0025] Step 2: Place the concrete specimen on the polytetrafluoroethylene plate according to the pulling direction, and connect the embedded parts at both ends of the concrete specimen with two ball joints;
[0026] Step 3: bury the temperature and humidity probe in the concrete specimen;
[0027] Step 4: Place the counterweight on the weight hanging rod for loading, and control the weight of the configured weight by observing the stress sensor to adjust the loading force; the loading force can be further accurately adjusted by sliding the weight.
[0028] Step 5: After loading is completed, the ball joint is removed and the concrete specimen is placed in the curing room for curing. The temperature and humidity monitoring system continuously monitors the state of the concrete.
[0029] It will be understood by those skilled in the art that, unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as generally understood by those skilled in the art in the art to which the present invention belongs. It should also be understood that terms such as those defined in common dictionaries should be understood to have meanings consistent with the meanings in the context of the prior art, and will not be interpreted with idealized or overly formal meanings unless defined as herein.
[0030] The above embodiments are only for explaining the technical idea of the present invention, and cannot be used to limit the protection scope of the present invention. Any changes made on the basis of the technical solution according to the technical idea proposed by the present invention shall fall within the protection scope of the present invention. The above embodiments of the present invention are described in detail, but the present invention is not limited to the above embodiments. Various changes can be made within the knowledge scope of ordinary technicians in the field without departing from the purpose of the present invention.
Claims
1. A device for measuring temperature and humidity of concrete under constant axial tension, characterized in that: The loading frame comprises a loading frame, wherein the loading frame comprises a column 1 (12) and a column 2 (13), the upper end of the column 1 (12) is hinged with a lever (4), the lever (4) comprises a front arm (41) and a rear arm (42), the length of the front arm (41) is less than the length of the rear arm (42), a Z-shaped transmission device (16) is hinged on the side wall of the column 1 (12), one end of the Z-shaped transmission device (16) is connected to the end of the front arm (41) through a pull rod 1 (6), and the other end is connected to a ball joint (8) through the pull rod 1 (6), and the side wall of the column 2 (13) is located at the Z-shaped A ball joint (8) is provided at the same height of the transmission device (16) through the second pull rod (20); a stress sensor (7) is provided on the first pull rod (6); a crossbeam (11) for placing a concrete test piece (9) is provided between the first column (12) and the second column (13); the rear arm (42) is located directly above the second column (13), and its end is connected to a hanging weight rod (2), and a plurality of counterweights (1) are placed under the hanging weight rod (2); and it also includes a plurality of temperature and humidity probes (10) and a temperature and humidity data collector (15) connected to the temperature and humidity probes (10); The lever (4) is slidably provided with an adjustment weight (5); A base (14) is provided at the bottom of the first column (12) and the second column (13).
2. The device for measuring temperature and humidity of concrete under constant axial tension according to claim 1, characterized in that: A safety wheel frame (3) for limiting the position of the lever (4) is arranged at the upper end of the second upright column (13).
3. The device for measuring temperature and humidity of concrete under constant axial tension according to claim 1, characterized in that: A polytetrafluoroethylene plate (18) is arranged on the cross beam (11), and oil is applied between the polytetrafluoroethylene plate (18) and the cross beam (11), and between the polytetrafluoroethylene plate (18) and the concrete test piece (9).
4. A method for measuring the temperature and humidity of concrete under constant axial tension using the measuring device according to claim 1, characterized in that: The following steps are involved: Step 1, making a concrete specimen and embedding embedded parts (171) at both ends of the concrete specimen along the pulling direction; Step 2: placing the concrete specimen on the polytetrafluoroethylene plate (18) according to the pulling direction, and connecting the embedded parts (171) at both ends of the concrete specimen with two ball joints (8); Step 3, embedding the temperature and humidity probe (10) in the concrete specimen; Step 4: Place the counterweight (1) on the weight hanging rod (2) for loading, and control the weight of the counterweight by observing the stress sensor (7) to adjust the loading force; Step 5: After loading is completed, the ball joint (8) is disassembled and the concrete specimen is placed in a curing room for curing. The temperature and humidity monitoring system continuously monitors the state of the concrete.
5. The method for measuring temperature and humidity of concrete under constant axial tension by the measuring device according to claim 4 is characterized in that: In step 4, the loading force can be further accurately adjusted by sliding the adjustment weight (5).