Multi-field coupling test device and test method for testing self-healing performance of filling body

Abstract

The application discloses a multi-field coupling test device and test method for testing self-healing performance of a filling body, wherein the test device comprises a test box, a solution tank, a loading assembly, a heating component and a data acquisition instrument; the top of the test box is provided with a liquid inlet; the bottom is provided with a liquid outlet; a plurality of independent solution bins are arranged in the solution tank; the solution bins are connected with the liquid inlet through pipelines; the loading assembly comprises a fixed mounting frame, a jack, an elastic member and a load sensor; the jack and the load sensor are respectively arranged at the two ends of the fixed mounting frame, and a filling body test block is arranged between the jack and the load sensor; one end of the elastic member is in abutment with the load sensor, and the other end is used for directly pressing the filling body test block; the heating component is arranged in the test box and is used for heating the solution in the test box; and the load sensor is connected with the data acquisition instrument. The test device can realize multi-field coupling synchronous action and has long-term stable load bearing capacity.

Description

Technical Field

[0001] This invention relates to the field of mine backfilling engineering technology, and more specifically to a multi-field coupling test device and test method for testing the self-healing performance of backfill bodies. Background Technology

[0002] Backfill mining is a key technology for achieving green mining, controlling rock strata movement, and ensuring underground safety. During long-term service, backfill materials are simultaneously subjected to the coupled effects of multiple factors, including in-situ stress loads, groundwater and salt ion erosion, and formation temperature changes. After damage and cracking under load, the self-healing ability of the backfill material, which relies solely on its own hydration reaction, is relatively weak, directly determining its long-term strength and service life. Therefore, developing a testing device capable of simulating the real underground environment to accurately test the self-healing performance of backfill materials is of significant engineering importance.

[0003] Currently, there are some devices available both domestically and internationally for testing the mechanics and durability of filling materials. However, existing technologies have the following fundamental shortcomings in simulating real service environments: (1) Existing test equipment is mostly used to study the durability of filling bodies. There is no test equipment for self-healing of filling bodies. Moreover, the single-factor test equipment can only carry out load test, dry-wet cycle test, salt solution erosion test or temperature effect test alone. It is difficult to apply three conditions at the same time: continuous constant load, controllable temperature environment and aqueous solution / salt solution erosion. This is far from the real working condition of "stress-seepage-temperature-chemical erosion" multi-field coupling downhole. The test results are difficult to reflect the actual service behavior of filling bodies. In particular, there is a lack of a dedicated system that integrates the three functions of loading, temperature control and erosion. Each module is independent and cannot achieve the synergistic, synchronous and long-term effect of force-temperature-chemical multi-field.

[0004] (2) Traditional material testing machines are mainly used for short-term loading. When the load is maintained for a long time, problems such as pressure decay and excessive fluctuation are likely to occur. They cannot provide a stable, constant and long-term stress state for the self-healing of the filling material damage, which leads to interference with the crack propagation and healing process of the filling material and distortion of the test results.

[0005] Therefore, it is an urgent problem for those skilled in the art to develop a multi-field coupling test device and test method that can achieve multi-field coupling synchronization and, in particular, has long-term stable load-bearing capacity for testing the self-healing performance of filling bodies. Summary of the Invention

[0006] In view of this, the present invention provides a multi-field coupling test device and test method that can realize multi-field coupling synchronization and, in particular, have long-term stable load-bearing capacity for testing the self-healing performance of filling bodies.

[0007] To achieve the above objectives, the present invention adopts the following technical solution: A multi-field coupled testing apparatus for testing the self-healing performance of filling materials includes: The test chamber has a liquid inlet at the top and a liquid outlet at the bottom. A solution tank, which contains multiple independent solution compartments; each solution compartment is connected to the inlet via a pipeline. A loading assembly includes: a fixed mounting frame, a jack, an elastic element, and a load sensor; the jack and the load sensor are respectively mounted at both ends of the fixed mounting frame, and a filling material test block is disposed between the jack and the load sensor; the output end of the jack faces and presses against the filling material test block; one end of the elastic element abuts against the load sensor, and the other end is used to directly press against the filling material test block; the jack applies a load to the filling material test block, and the elastic element maintains a long-term constant load on the filling material test block by utilizing its elastic deformation; A heating element is disposed inside the test chamber to heat the solution inside the test chamber; A data acquisition instrument, wherein the load sensor is connected to the data acquisition instrument.

[0008] Preferably, the test chamber is equipped with a temperature sensor for real-time monitoring of the temperature inside the chamber, and the temperature sensor is connected to the data acquisition instrument.

[0009] Preferably, a temperature controller is provided on the outside of the test chamber, and the heating element and temperature sensor are connected to the temperature controller through a temperature control data line. The temperature controller receives the temperature signal transmitted by the temperature sensor and adjusts the heating temperature of the heating element.

[0010] Preferably, the solution tank contains an aqueous solution tank and a compound salt solution tank.

[0011] Preferably, a flow control valve is installed on the pipeline connecting the aqueous solution tank or the composite salt solution tank to the inlet.

[0012] Preferably, the fixed mounting frame includes a base plate and a mounting plate; the mounting plate is disposed at both ends of the top of the base plate, and the jack and load sensor are respectively connected to the mounting plates at both ends.

[0013] Preferably, a reinforcing plate is added at the connection between the mounting plate and the base plate.

[0014] Preferably, a loading frame is provided on the outside of the filling material test block, and the loading frame is placed on top of the base plate; the loading frame includes: adjusting rods and sliding plates, the filling material test block is placed between two of the sliding plates, and the elastic element is provided between the sliding plate near the load sensor and the filling material test block, and multiple adjusting rods pass through the two sliding plates, and the sliding plates slide along the adjusting rods.

[0015] Preferably, the elastic element is a butterfly spring, and the end of the butterfly spring that contacts the sliding plate or the filling material test block is provided with a gasket.

[0016] Preferably, adjusting nuts are threaded to both ends of the adjusting rod.

[0017] The test method for a multi-field coupled test apparatus for testing the self-healing performance of filling materials includes the following test steps: S1, Install the test specimen: Place the cured filling specimen into the test chamber and position the filling specimen between the two sliding plates of the loading frame. Adjust the adjusting nut to make the sliding plate contact the filling specimen. Close and seal the door of the test chamber to ensure a closed test environment. S2, Apply constant load: After the filling material test block is placed into the test chamber, start the jack to push the load sensor and elastic element, so that the elastic element is in close contact with the filling material test block; apply the target load according to the test requirements, and lock the hydraulic circuit of the jack after the preset load value is reached; S3, Set Temperature: Set the target temperature through the temperature controller; the heating element starts heating, and the temperature sensor feeds back the temperature of the solution in the chamber to the temperature controller in real time, so that the temperature of the solution in the chamber can quickly reach the set value and remain constant; S4, Injecting the etching solution: Open the flow control valve corresponding to the required solution chamber, draw the solution from the aqueous solution chamber or composite salt solution chamber of the solution tank, and inject it into the test chamber through the pipeline and inlet until the solution completely soaks the filling block; close the flow control valve to maintain a closed etching environment; S5, Long-term testing and data acquisition: During the set test period, the load sensor and temperature sensor continuously collect data, which is automatically recorded by the multi-channel data acquisition instrument; the device maintains stable operation in the multi-field coupling state of load-temperature-solution until the end of the test, and fully records the entire process of the filling body specimen from loading cracking to self-healing. S6, stop heating, release the load, and drain the solution from the test chamber through the outlet; open the test chamber and take out the filling material test block; test the test block for indicators such as strength recovery rate, crack closure rate, and mass change rate to evaluate the self-healing effect of the filling material.

[0018] As can be seen from the above technical solution, compared with the prior art, the present invention discloses a multi-field coupling test device and test method for testing the self-healing performance of filling bodies, the beneficial effects of which are: (1) The present invention integrates the loading component, heating component, solution tank and temperature control system into one, which can simultaneously apply a continuous constant load, precise and controllable temperature and switchable aqueous / salt solution erosion to the filling body test block, realize the synergistic, synchronous and long-term effect of force-temperature-chemical multi-field, and is closer to the real service environment of "stress-seepage-temperature-chemical erosion" in the mine. (2) The present invention adopts a combined load-holding structure of "hydraulic jack + disc spring". The jack is responsible for applying the target load quickly and accurately, and the disc spring uses its elastic deformation to maintain the load stability for a long time. This effectively overcomes the defects of pressure attenuation and excessive fluctuation when the traditional material testing machine holds the load for a long time, and provides a constant stress environment that is not disturbed for the slow self-healing process of the filling body crack, thus ensuring the authenticity and reliability of the test data. (3) The present invention forms a closed-loop constant temperature control by temperature sensor and temperature controller, which can stably control the test temperature at key temperature points such as 20℃, 30℃, and 40℃; by setting up independently separated aqueous solution chamber and composite salt solution chamber and flow control valve, the rapid switching and circulation erosion of aqueous solution and salt solution can be realized, which solves the problems of single environmental conditions, inconvenient switching and low temperature control accuracy of existing devices. (4) The loading, temperature control, erosion and data acquisition functions of the present invention are highly integrated into one, and the structure is compact. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0020] Figure 1 A top view of the experimental apparatus provided by the present invention; Figure 2 A top view of the external structure of the test apparatus provided by the present invention; Figure 3 This is a schematic diagram of the structure of the loading component for loading the filling body test block provided by the present invention; Figure 4 A top view of the mounting bracket provided by the present invention; Figure 5 This is a front view of the mounting bracket provided by the present invention; Figure 6 This is a top view of the loading frame provided by the present invention.

[0021] In the figure, 1-Test chamber; 11-Inlet; 12-Outlet; 2-Solution tank; 21-Aqueous solution chamber; 22-Compound salt solution chamber; 3-Loading assembly; 31-Fixed mounting bracket; 311-Base plate; 312-Mounting plate; 313-Reinforcing plate; 32-Jack; 33-Elastic element; 34-Load sensor; 35-Loading frame; 351-Adjusting rod; 352-Sliding plate; 353-Gasket; 354-Adjusting nut; 4-Filling block; 5-Heating component; 6-Data acquisition instrument; 7-Temperature sensor; 8-Temperature controller; 9-Flow control valve. Detailed Implementation

[0022] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0023] See Figures 1 to 6 The multi-field coupling test device for testing the self-healing performance of filling bodies provided by the present invention includes: a test chamber 1, a solution tank 2, a loading component 3, a heating component 5, and a data acquisition instrument 6.

[0024] The test chamber 1 is a sealed stainless steel chamber structure with a liquid inlet 11 at the top and a liquid outlet 12 at the bottom. The liquid inlet 11 is located on the upper part of the side wall of the test chamber 1, and the liquid outlet 12 is located on the lower part of the side wall of the test chamber 1. These are used for the injection and discharge of the solution, respectively, to achieve complete immersion and corrosion of the filling material test block 4 and solution replacement. The side walls and top plate of the test chamber 1 are sealed to prevent solution leakage and heat loss.

[0025] The solution tank 2 contains multiple independent solution chambers. In a preferred embodiment, the solution chambers include an aqueous solution chamber 21 and a composite salt solution chamber 22. Each solution chamber is connected to the inlet 11 of the test chamber 1 via an independent pipeline. Each pipeline is equipped with a flow control valve 9 to control the on / off state of the solution, the flow rate, and to switch media between the aqueous solution chamber 21 and the composite salt solution chamber 22, meeting the self-healing test requirements under different corrosion conditions.

[0026] The loading assembly 3 is used to apply and maintain a long-term constant load on the filling material test block 4. The loading assembly 3 includes: a fixed mounting bracket 31, a jack 32, an elastic element 33, and a load sensor 34.

[0027] The fixed mounting bracket 31 includes a base plate 311 and a mounting plate 312, with the mounting plate 312 disposed at both ends of the top of the base plate 311. In a preferred embodiment, a reinforcing plate 313 is added at the connection between the mounting plate 312 and the base plate 311 to improve the overall rigidity.

[0028] The jack 32 and load sensor 34 are respectively mounted on the mounting plates 312 at both ends of the fixed mounting bracket 31, and a filling material test block 4 is disposed between the jack 32 and the load sensor 34. The output end of the jack 32 faces and presses against the filling material test block 4. In this embodiment, the jack 32 is a hydraulic jack, used to apply a preset target load to the filling material test block 4.

[0029] The load sensor 34 is located between the jack 32 and the elastic element 33. It is used to collect the loading force value in real time and is connected to the data acquisition instrument 6 via a data cable.

[0030] One end of the elastic element 33 abuts against the load sensor 34, and the other end is used to directly press against the filling material test block 4. In a preferred embodiment, the elastic element 33 is a butterfly spring, and a washer 353 is provided at the end of the butterfly spring that contacts the sliding plate 352 or the filling material test block 4. After the jack 32 applies a load to the filling material test block 4, the elastic element 33 uses its elastic deformation to maintain a long-term constant load on the filling material test block 4, thereby achieving combined load maintenance by hydraulic and mechanical springs.

[0031] See Figure 3 and Figure 6 In a preferred embodiment, a loading frame 35 is provided on the outside of the filling material test block 4, and the loading frame 35 is placed on top of the base plate 311. The loading frame 35 includes: adjusting rods 351 and sliding plates 352. The filling material test block 4 is placed between the two sliding plates 352, and an elastic element 33 is provided between the sliding plate 352 near the load sensor 34 and the filling material test block 4. Multiple adjusting rods 351 pass through the two sliding plates 352, and the sliding plates 352 can slide along the adjusting rods 351. Adjusting nuts 354 are threaded to both ends of the adjusting rods 351 for adjusting the sliding plates 352 at the extreme positions of the adjusting rods 351.

[0032] Heating element 5 is installed inside the test chamber 1 to heat the solution inside the test chamber 1. In a preferred embodiment, heating element 5 is installed at the bottom of the test chamber 1 and distributed along the four corners of the test chamber 1, or in a ring shape, to ensure more uniform heating of the solution. Heating element 5 is electrically connected to temperature controller 8, which can stably control the temperature inside the chamber at three set values: 20℃, 30℃, and 40℃, thereby regulating the hydration and self-healing rate of the filling material test block 4. Heating element 5 can be an electric heating tube or a heating plate.

[0033] A temperature sensor 7 is installed inside the test chamber 1 for real-time monitoring of the solution temperature inside the chamber. A temperature controller 8 is installed outside the test chamber 1. The heating element 5 and the temperature sensor 7 are both connected to the temperature controller 8 via a temperature control data cable. The temperature controller 8 receives the temperature signal transmitted by the temperature sensor 7 and adjusts the heating temperature of the heating element 5 to form a closed-loop constant temperature control. The temperature sensor 7 is also connected to a data acquisition instrument 6 for real-time recording of temperature data.

[0034] The data acquisition instrument 6 is a multi-channel data acquisition instrument, which is connected to the load sensor 34 and the temperature sensor 7 respectively. It is used to collect load data and temperature data in real time during the test, observe the deformation of the sample, and record the entire process of self-healing of the filling body.

[0035] The test method for a multi-field coupled test apparatus for testing the self-healing performance of filling materials is as follows: S1. Sample Installation: Place the cured standard cubic or cylindrical filling block 4 into the test chamber 1. Position the filling block 4 between the two sliding plates 352 of the loading frame 35. Adjust the adjusting nut 354 to ensure proper contact between the sliding plates 352 and the filling block 4. Close and seal the door of the test chamber 1 to ensure a sealed test environment.

[0036] S2, Apply a constant load: Activate jack 32 (hydraulic jack) to push load sensor 34 and elastic element 33 (disc spring assembly), ensuring tight contact between elastic element 33 and the filling material specimen 4. Apply the target load as required by the test, and lock the hydraulic circuit of jack 32 after reaching the preset load value. At this time, the elastic element 33 mainly maintains the long-term stability of the load by utilizing its elastic deformation, compensating for the pressure attenuation caused by specimen deformation or system relaxation, and ensuring that the filling material specimen 4 is subjected to constant force during the test cycle.

[0037] S3, Set Temperature: Set the target temperature (e.g., 20℃, 30℃, or 40℃) via temperature controller 8. Heating component 5 starts heating, and temperature sensor 7 provides real-time feedback of the solution temperature inside the chamber to temperature controller 8, enabling the solution temperature inside the chamber to quickly reach the set value and remain constant.

[0038] S4, Inject the etching solution: Open the flow control valve 9 corresponding to the required solution chamber, draw the solution from the aqueous solution chamber 21 or the composite salt solution chamber 22 of the solution tank 2, and inject it into the test chamber 1 through the pipeline and inlet 11 until the solution completely soaks the filling block 4. Close the flow control valve 9 to maintain a closed etching environment.

[0039] S5, Long-term testing and data acquisition: Within the set test period (e.g., 28 days), the load sensor 34 and temperature sensor 7 continuously collect data, which is automatically recorded by the multi-channel data acquisition instrument 6. The device maintains stable operation in a multi-field coupling state of load-temperature-solution until the end of the test, and fully records the entire process of the filling block 4 from loading cracking to self-healing.

[0040] S6, stop heating, release the load, and drain the solution from test chamber 1 through outlet 12. Open test chamber 1 and remove the filling material test block 4. Test the test block for indicators such as strength recovery rate, crack closure rate, and mass change rate to evaluate the self-healing effect of the filling material.

[0041] The table below lists the results of three tests: Based on the results of the three tests above, it can be concluded that by integrating controllable temperature, controllable solution, and continuous constant load, the technical problems of existing devices being unable to simulate real multi-field environments downhole, inaccurate temperature control, unstable load maintenance, and uncontrollable erosion have been solved, and accurate, stable, and repeatable testing of the self-healing performance of the filling body has been achieved.

[0042] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0043] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A multi-field coupled test apparatus for testing the self-healing performance of filling materials, characterized in that, include: The test chamber has a liquid inlet at the top and a liquid outlet at the bottom. A solution tank, which contains multiple independent solution compartments; each solution compartment is connected to the inlet via a pipeline. A loading assembly includes: a fixed mounting frame, a jack, an elastic element, and a load sensor; the jack and the load sensor are respectively mounted at both ends of the fixed mounting frame, and a filling material test block is disposed between the jack and the load sensor; the output end of the jack faces and presses against the filling material test block; one end of the elastic element abuts against the load sensor, and the other end is used to directly press against the filling material test block; the jack applies a load to the filling material test block, and the elastic element maintains a long-term constant load on the filling material test block by utilizing its elastic deformation; A heating element is disposed inside the test chamber to heat the solution inside the test chamber; A data acquisition instrument, wherein the load sensor is connected to the data acquisition instrument.

2. The multi-field coupling test apparatus for testing the self-healing performance of filling bodies according to claim 1, characterized in that, The test chamber is equipped with a temperature sensor for real-time monitoring of the temperature inside the chamber, and the temperature sensor is connected to the data acquisition instrument.

3. The multi-field coupling test apparatus for testing the self-healing performance of filling bodies according to claim 2, characterized in that, A temperature controller is installed on the outside of the test chamber. The heating element and the temperature sensor are connected to the temperature controller via a temperature control data line. The temperature controller receives the temperature signal transmitted by the temperature sensor and adjusts the heating temperature of the heating element.

4. The multi-field coupling test apparatus for testing the self-healing performance of filling bodies according to claim 1, characterized in that, The solution tank contains an aqueous solution compartment and a compound salt solution compartment; a flow control valve is installed on the pipeline connecting the aqueous solution compartment or the compound salt solution compartment to the inlet.

5. The multi-field coupling test apparatus for testing the self-healing performance of filling bodies according to claim 1, characterized in that, The fixed mounting frame includes a base plate and a mounting plate; the mounting plate is disposed at both ends of the top of the base plate, and the jack and load sensor are respectively connected to the mounting plates at both ends.

6. The multi-field coupling test apparatus for testing the self-healing performance of filling bodies according to claim 5, characterized in that, A reinforcing plate is added to the connection between the mounting plate and the base plate.

7. The multi-field coupling test apparatus for testing the self-healing performance of filling bodies according to claim 1, characterized in that, The filling material test block is provided with a loading frame on the outside, and the loading frame is placed on top of the base plate; the loading frame includes: adjusting rods and sliding plates, the filling material test block is placed between two sliding plates, and the elastic element is provided between the sliding plate near the load sensor and the filling material test block, and multiple adjusting rods pass through the two sliding plates, and the sliding plates slide along the adjusting rods.

8. The multi-field coupling test apparatus for testing the self-healing performance of filling bodies according to claim 7, characterized in that, The elastic element is a butterfly spring, and a gasket is provided at the end of the butterfly spring that contacts the sliding plate or the filling material test block.

9. The multi-field coupling test apparatus for testing the self-healing performance of filling bodies according to claim 8, characterized in that, The two ends of the adjusting rod are threaded with adjusting nuts.

10. The test method of the multi-field coupled test apparatus for testing the self-healing performance of filling bodies as described in any one of claims 1-9, characterized in that, The test steps include the following: S1, Install the test specimen: Place the cured filling specimen into the test chamber and position the filling specimen between the two sliding plates of the loading frame. Adjust the adjusting nut to make the sliding plate contact the filling specimen. Close and seal the door of the test chamber to ensure a closed test environment. S2, Apply constant load: After the filling material test block is placed into the test chamber, start the jack to push the load sensor and elastic element, so that the elastic element is in close contact with the filling material test block; apply the target load according to the test requirements, and lock the hydraulic circuit of the jack after the preset load value is reached; S3, Set Temperature: Set the target temperature through the temperature controller; the heating element starts heating, and the temperature sensor feeds back the temperature of the solution in the chamber to the temperature controller in real time, so that the temperature of the solution in the chamber can quickly reach the set value and remain constant; S4, Injecting the etching solution: Open the flow control valve corresponding to the required solution chamber, draw the solution from the aqueous solution chamber or composite salt solution chamber of the solution tank, and inject it into the test chamber through the pipeline and inlet until the solution completely soaks the filling block; close the flow control valve to maintain a closed etching environment; S5, Long-term testing and data acquisition: During the set test period, the load sensor and temperature sensor continuously collect data, which is automatically recorded by the multi-channel data acquisition instrument; the device maintains stable operation in the multi-field coupling state of load-temperature-solution until the end of the test, and fully records the entire process of the filling body specimen from loading cracking to self-healing. S6, stop heating, release the load, and discharge the solution inside the test chamber through the outlet; Open the test chamber and take out the filling material test block; test the test block for indicators such as strength recovery rate, crack closure rate, and mass change rate to evaluate the self-healing effect of the filling material.

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