A high-precision concrete liquid penetration test integrated system and usage method

Abstract

A high-precision integrated system for concrete liquid penetration testing and its use method are described. The system includes a sealed liquid holding tank, a self-priming turbine, a tank, an upstream high-precision flowmeter, a downstream high-precision flowmeter, a data acquisition port set, a downstream data acquisition port set, a liquid pressure detector, a digital differential pressure sensor, a concrete penetration device, and a multi-channel recorder. The system comprehensively collects the flow velocity, surface pressure, and upper and lower pressure differential of liquid before and after flowing through a concrete specimen, and synchronously displays the real-time data to computer software. Synchronous data acquisition ensures the accuracy of test data under different boundary conditions. The system can accurately measure the penetration performance of concrete specimens of different shapes and fracture states under different pressures without affecting the structural integrity of the specimens.

Description

Technical Field

[0001] The present invention relates to the field of liquid penetration ability evaluation of different concrete materials, and in particular to a high-precision concrete liquid penetration test integrated system and a use method. Background Art

[0002] Functional concrete materials have been widely used in the construction field due to their excellent mechanical properties. However, due to their internal porous structure and easy cracking characteristics, their permeability and transmission performance has become a matter of great concern. In order to better understand the connectivity paths in the internal structure of concrete, it is crucial to reasonably and effectively evaluate its permeability, which is directly related to the durability prediction of concrete and the material transmission performance of functional concrete. In particular, the existence of connectivity paths increases the risk of intrusion of harmful substances, which in turn leads to steel corrosion and changes in the internal microstructure, ultimately affecting the service life of structural concrete. In the permeability test, the connectivity paths inside the concrete simultaneously affect the viscosity and inertial dissipation capacity of the fluid, thereby affecting the material transmission efficiency. Therefore, accurately measuring the viscous permeability and inertial permeability of concrete is crucial for quantifying its related performance, which not only provides reliable data support for the full life cycle prediction of concrete, but also lays a quantitative parameter foundation for the material design of functional concrete.

[0003] The HS concrete permeameter, included in the "Concrete Impermeability Tester" (JG / T 249-2009), mentioned in the "Standard for Test Methods for Long-Term Performance and Durability of Ordinary Concrete" (GB / T 50082-2009), is widely used to determine the penetration depth and permeability grade of uncracked ordinary concrete. However, this test method has limitations and cannot directly measure the permeability coefficient of concrete. This is because the boundary parameters for water penetration into concrete are difficult to determine during the test, and the water flux cannot be directly estimated. Furthermore, the test requires splitting measurements of the concrete specimens, a cumbersome process with limited accuracy, making it difficult to apply to the assessment of various concrete transport properties. Numerous authoritative journal articles have pointed out that liquids exhibit significant nonlinear flow behavior when flowing through interconnected voids or cracks within concrete. Research has shown that, in practical engineering, a reasonable assessment of concrete's material transport properties and accurate determination of its inherent permeability are crucial for the mix design of permeable concrete and the assessment of the durability of cracked or uncracked structural concrete. Furthermore, testing the transport velocity under multiple pressure gradients is also essential. The permeability coefficient measuring instruments recommended in the current "Permeable Concrete Test Method" (T / CSTM 00040-2019), or the permeability coefficient testing devices provided in patents CN109142183A and CN110618069A, all use a test method based on a specific liquid level, calculating the time required for a specific amount of water to permeate a permeable concrete specimen. However, these devices and methods have several shortcomings: 1. Single pressure gradient measurement: Current testing methods rely on Darcy's law and measure flow rate only under a single pressure gradient. This makes it difficult to observe the nonlinear behavior of the fluid or analyze the geometric characteristics of the interconnecting paths within the concrete by varying the pressure gradient. This limits a comprehensive understanding of complex permeability paths and concrete permeability behavior under different operating conditions. 2. Inaccurate pressure measurement: The pressure obtained during the test is the pressure on the upper surface of the specimen, not the effective pressure gradient. As a result, the test results do not fully reflect the actual fluid transmission within the specimen. 3. Complex channel connectivity and inaccurate boundary parameters: The channel connectivity between the upper and lower liquid levels of the specimen is complex, making it difficult for the test device's sensors to effectively measure pressure changes between the upper and lower liquid levels. When liquid flows through these complex channels, the resulting pressure loss is not accurately recorded, resulting in an underestimation of the permeability coefficient test result. 4. Single test conditions: Existing testing systems are only applicable under specific conditions and are difficult to adapt to concrete specimens under different working conditions, especially specimens of different sizes, shapes, and types. This makes the testing system limited when dealing with complex and changing real-world conditions.

[0004] Publication No. CN114923833B describes a device for measuring the permeability coefficient of high-permeability concrete. This device utilizes a gravity sensor and an open-type data acquisition method to measure water flux per unit time under varying pressure gradients by varying water pressure. However, this device still suffers from several drawbacks: 1. Data acquisition is discontinuous, resulting in low cumulative observation efficiency and a lack of fluid temperature observation. The device uses a gravimetric method to measure flow rate, requiring cumulative flow observations over a specific time period, resulting in low test efficiency. Furthermore, pressure control is limited to a specific gradient, and the test fluid temperature is not effectively monitored, making it difficult to achieve a more accurate assessment of fluid transport behavior and subjecting the observed data to errors. 2. The test sample application range is limited. Due to the limited pressure adjustment range, the device is primarily suitable for highly permeable concrete specimens, such as cracked concrete or permeable concrete. It has limitations when testing uncracked, ordinary concrete, and cannot effectively measure its permeability. 3. The fluid circulation is not closed, posing a safety hazard. The device uses an open-type test method, which cannot achieve fluid circulation within a closed pipe. This design can easily cause liquid splashing, especially toxic liquids, which can cause environmental pollution and operational safety issues. 4. Separate data collection increases analysis complexity. Pressure gradient and water flow rate are collected separately, lacking simultaneous data, resulting in high data integration and analysis costs. Furthermore, the increased time required to collect and analyze data compromises the convenience of the testing process. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to overcome the multiple limitations of the existing penetration testing technology in the prior art, namely, the inability to accurately measure fluid transmission behavior under multiple pressure gradients, the cumbersome operation steps and the unsuitability for boundary condition control under complex working conditions, the difficulty in keeping data collection and analysis synchronized, and provide a high-precision concrete liquid penetration test integrated system and usage method.

[0006] The technical solution adopted by the present invention to solve the technical problem is a high-precision concrete liquid penetration test integrated system, including a closed liquid holding box, a self-priming turbine, a tank body, an upstream high-precision flow meter, a downstream high-precision flow meter, a data acquisition port set, a downstream data acquisition port set, a liquid pressure detector, a digital display differential pressure sensor, a concrete penetration device, and a multi-channel recorder;

[0007] The self-priming turbine is connected to the closed liquid holding tank via a conduit, the closed liquid holding tank is connected to the tank body via a conduit, an air compressor and a fine-tuning pressure ball valve are provided on the tank body, and the tank body is connected to an upstream high-precision flow meter via the fine-tuning pressure ball valve;

[0008] The upstream high-precision flow meter is connected to the data acquisition port set through a conduit. The data acquisition port set is provided with no less than four ports, and is respectively connected to a liquid pressure detector, a digital differential pressure sensor, and a concrete penetration device through conduits. At the same time, the concrete penetration device is connected to the downstream data acquisition port set.

[0009] The downstream data acquisition port set is provided with no less than three ports, and is connected to the digital differential pressure sensor and the downstream high-precision flow meter via a conduit, and the downstream high-precision flow meter flows back to the closed liquid holding tank via the conduit;

[0010] The upstream high-precision flow meter, the downstream high-precision flow meter, the liquid pressure detector, and the digital differential pressure sensor are all connected to the multi-channel recorder through lines, and the multi-channel recorder is connected to the computer terminal through lines.

[0011] Furthermore, the sealed liquid holding box has no less than four connection ports, which are respectively connected to an outflow pipe, a pumping and filling pipe, a reflux pipe, and a temperature measuring instrument.

[0012] Furthermore, the self-priming turbine has a suction end and an output end, the outflow pipe is connected to the suction end, and the self-priming turbine generates pumping pressure for the liquid and pumps the liquid from the output end to the tank.

[0013] Furthermore, the tank body has no less than three connection ports, which are respectively connected to an air compressor, a pumping pipe, and a check pipe. A third one-way check valve is provided on the check pipe. The other end of the third one-way check valve is connected to an intermediate pipe, and the other end of the intermediate pipe is connected to a fine-tuning pressure ball valve.

[0014] Furthermore, the conduits are all made of high-pressure resistant materials, and the joint parts are all connected by high-pressure resistant threaded sealing.

[0015] Furthermore, the concrete infiltration device includes a penetration box, a liquid inlet pipe, a liquid outlet pipe, and a liquid collection container. The liquid inlet and liquid outlet are both provided with liquid separation channels, and the liquid separation channels are both connected to ball valves, and the ball valves are both connected to the liquid collection container through a conduit; the liquid inlet and liquid outlet are relatively arranged on both sides of the penetration box.

[0016] Furthermore, a concrete specimen is sealed in the penetration box, a side of the concrete specimen is sealed with adhesive tape, and a gap between the penetration box and the concrete specimen is filled with liquid sealant.

[0017] The present invention further solves the technical problem by adopting a technical solution that provides a method for using a high-precision concrete liquid penetration test integrated system, comprising the following steps:

[0018] S1. Perform vacuum saturation treatment on the concrete specimen for 1 to 2 hours to reduce the time to reach a stable state, wherein the treatment area includes the crack area of ​​cracked concrete or the hydraulic exposure area of ​​permeable concrete / porous ordinary concrete;

[0019] S2. Before installing the concrete specimen, there are no restrictions on the geometric shape of the specimen cross section. However, the cross section must remain consistent in the direction of liquid flow or specimen height, and the communication path between the upper and lower pressure surfaces of the specimen must be free of lateral leakage. Initially seal the concrete specimen with tape on the sides and upper and lower ends. Place the concrete specimen in a penetration box and fill the gap between the penetration box and the specimen with liquid sealant. After the sealant dries, cut off the tape on the upper and lower pressure surfaces to expose the test area.

[0020] S3. Install the sealed concrete specimen into the concrete penetration device, and install the device into the high-precision concrete liquid penetration test integrated system;

[0021] S4. Check the liquid level of the sealed liquid holding tank to ensure that the liquid level is between 2 / 3 and 4 / 5 of the total height of the tank, and place the probe of the temperature detector between 1 / 3 and 2 / 3 of the distance between the liquid level and the bottom of the tank;

[0022] S5. Test-run the equipment, set the pressure of the self-priming turbine to 0.01 to 1 MPa, open the fine-tuning pressure ball valve, check that the wiring is in good contact, confirm that the data collected by the upstream and downstream high-precision flow meters, liquid pressure detectors, and digital differential pressure sensors can be recorded and displayed by the multi-channel recorder and displayed on the computer, and check all conduit interfaces to ensure that they are leak-proof and well-sealed;

[0023] S6. Gradually increase the pressure of the self-priming turbine to ensure that the pressure of the liquid pressure detector is lower than the compressive strength of the concrete specimen. When the flow rate reaches 80% of the range of the upstream high-precision flow meter or 80% of the range of the digital differential pressure sensor, stop pressurizing. If the pressure is insufficient, increase the pressure through the conduit and air compressor. Maintain this flow state during the test, observe the bubbles in the liquid collection container, and close the ball valve to effectively remove the gas in the system. When the flow rate difference does not exceed 7% of the reading, it is considered that a turbulent state has been achieved. For denser specimens, the ball valve can be selectively opened to accelerate the time it takes for the liquid to fill the entire system.

[0024] S7. After the entire test system is filled with liquid, formal testing and data collection begin. Adjust the pressure value of the self-priming turbine so that the reading of the digital differential pressure sensor or the flow rate reading of the downstream high-precision flow meter reaches the minimum. Turn on the temperature measuring instrument to record the temperature of the test liquid, and gradually increase the pressure of the liquid pump system until the collected reading reaches 80% of the measuring range. Record the collected results as continuous pressure gradients {ΔP│ΔP1, ΔP2, ΔP3, ..., ΔPn} and flow rates {Q│Q1, Q2, Q3, ..., Qn}, where the data have isochronous properties.

[0025] S8. Query the fluid physical property data according to the liquid temperature value to confirm the viscosity and density of the liquid at that temperature; import the collected data {ΔP│ΔP1, ΔP2, ΔP3, …, ΔPn} and {Q│Q1, Q2, Q3, …, Qn} into the calculation, and use the formula to calculate the linear coefficient A and the nonlinear coefficient B, and then import the results into the formula to calculate the inherent permeability coefficient K v and inertial permeability coefficient K i .

[0026] Furthermore, the calculation formula in step S8 is:

[0027]

[0028] The linear coefficient A and nonlinear coefficient B are calculated and substituted into formulas (2) and (3) to calculate the inherent permeability coefficient K. v and inertial permeability coefficient K i :

[0029]

[0030]

[0031] In summary, the present invention has the following beneficial technical effects:

[0032] 1. A sealed closed-loop liquid seepage test helps prevent liquid splashing, contamination, and even safety hazards. 2. Digitally controlled pressure gradient and upper surface pressure detection reduce pressure fluctuations, enabling more accurate testing of the boundary parameters required for concrete permeability. It also monitors liquid pressure to prevent excessive hydraulic pressure on the upper surface of the concrete, which could alter or even damage the pore structure. 3. High-precision flowmeters are used upstream and downstream to monitor the inflow and outflow of liquid, allowing real-time observation of capillary suction, determining the saturated flow stage of the liquid as it passes through the test concrete, and measuring the time required to reach this stage. 4. Isochronous and real-time observation of each boundary parameter reduces measurement errors caused by various human factors during manual testing, and the device features coarse and fine adjustments to the pressure gradient of the specimen. 5. Highly portable and maneuverable, it is suitable for concrete specimens under different working conditions, providing accurate evaluation and testing, and providing hardware and testing method support for the connectivity of concrete voids, durability assessment during service, and the quantification of transmission performance in the mix design of permeable concrete. 6. This design contributes to the integration and intelligent automation of concrete material permeability testing and provides theoretical support for the manufacture of precision instruments in laboratories. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 This is a structural schematic diagram of an embodiment of a high-precision concrete liquid penetration test integrated system of the present invention;

[0034] Figure 2 This is a structural schematic diagram of a concrete penetration device according to an embodiment of a high-precision concrete liquid penetration test integrated system of the present invention;

[0035] Figure 3 It is a schematic diagram of a specimen sealing joint in an embodiment of a high-precision concrete liquid penetration test integrated system of the present invention.

[0036] Description of reference numerals:

[0037] 100, sealed liquid holding tank; 101, outflow port; 102, return port; 103, pumping port; 110, outflow pipe; 111, pumping pipe; 112, return pipe; 120, temperature measuring instrument; 121, probe; 130, tank filter; 200, self-priming turbine; 201, suction port; 202, output port; 203, digital display; 204, pressure control button; 300, tank; 301, boost port; 302, pumping port; 303, check port; 310, inlet pipe ; 311, first one-way check valve; 312, pump inlet pipe; 320, connecting conduit; 321, second one-way check valve; 322, air inlet pipe; 323, air compressor; 330, check pipe; 331, third one-way check valve; 332, intermediate pipe; 340, fine-tuning pressure ball valve; 400, upstream high-precision flowmeter; 401, inlet conduit; 402, outflow conduit; 410, downstream high-precision flowmeter; 411, downstream flowmeter conduit; 500, data acquisition port set; 501, flowmeter Port; 502, upstream pressure differential port; 503, penetration port; 504, pressure detection port; 510, downstream data acquisition port set; 511, filter port; 512, downstream pressure differential port; 513, downstream flow meter port; 520, intermediate filter; 521, filter inlet conduit; 522, filter outlet conduit; 600, liquid pressure detector; 700, digital pressure differential sensor; 701, high-pressure area conduit; 702, low-pressure area conduit; 800, concrete penetration device; 801, penetration inlet Catheter; 810, penetration box; 811, liquid sealant; 812, liquid inlet pipe; 813, liquid outlet pipe; 814, inlet liquid separation channel; 815, outlet liquid separation channel; 816, tape; 820, concrete specimen; 830, liquid collection container; 831, toxic gas filter; 840, inlet duct; 841, first ball valve; 842, upstream duct; 843, downstream duct; 844, second ball valve; 845, outlet duct; 900, multi-channel recorder; 910, computer terminal. DETAILED DESCRIPTION

[0038] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments.

[0039] Reference Figure 1 This embodiment includes a sealed liquid holding tank 100, a self-priming turbine 200, a tank body 300, an upstream high-precision flow meter 400, a downstream high-precision flow meter 410, a data acquisition port set 500, a downstream data acquisition port set 510, a liquid pressure detector 600, a digital differential pressure sensor 700, a concrete penetration device 800, and a multi-channel recorder 900.

[0040] The sealed liquid holding box 100 is made of a high-strength, corrosion-resistant material with good sealing properties and is used to store test liquid. The sealed liquid holding box 100 is equipped with four connection ports, namely an outflow port 101, a reflux port 102, a pumping and filling port 103, and a port for temperature measurement. The outflow port 101 is connected to an outflow pipe 110, the reflux port 102 is connected to a reflux pipe 112, and the pumping and filling port 103 is connected to a pumping and filling pipe 111, through which liquid can be taken out and filled. A temperature measuring instrument 120 is provided on the temperature measurement port, and a probe 121 is provided at the bottom of the temperature measuring instrument 120 so that the liquid temperature can be displayed in real time by the temperature measuring instrument 120. In addition, a high-mesh, low-pore size box filter 130 is installed at one end of the outflow pipe 110 located inside the sealed liquid holding box 100 to ensure the purity and safety of the liquid in the entire system. In this embodiment, the liquid level of the sealed liquid holding box 100 should be located at 2 / 3 to 4 / 5 of the total height of the box, the probe 121 should be placed at 1 / 3 to 2 / 3 between the liquid level and the bottom of the box, and the bottom of the return pipe 112 should be higher than the top of the liquid level.

[0041] The self-priming turbine 200 has two ports, a suction port 201 and an output port 202, as well as a digital display 203 and a pressure control button 204. Liquid enters the suction port 201 of the self-priming turbine 200 through the outflow pipe 110 of the sealed liquid holding tank 100, connecting the outflow pipe 110 to the suction port 201. The self-priming turbine 200 generates pumping pressure for the liquid, which is then adjusted in conjunction with the digital display 203, the switch, and the pressure control button 204 to regulate the system pressure. Furthermore, the self-priming turbine 200 incorporates an intelligent pressure control module, enabling silent, self-priming, variable-frequency, and constant-pressure pumping, ensuring system safety and stability during extended seepage tests.

[0042] The tank body 300 is made of high-pressure-resistant steel and has three ports: a boost port 301, a pumping port 302, and a check port 303. The boost port 301 is connected in sequence to a connecting conduit 320, a second one-way check valve 321, an air inlet pipe 322, and an air compressor 323. The compressed air inlet pipe 322 and the air compressor 323 further increase the pressure, thereby ensuring the stability of the liquid pressure within the system. The pumping port 302 is connected in sequence to an inlet pipe 310, a first one-way check valve 311, and a pumping pipe 312. The check port 303 is connected in sequence to a check pipe 330, a third one-way check valve 331, an intermediate pipe 332, and a fine-tuning pressure ball valve 340. Driven by sufficient pressure, the liquid flows from the check pipe 330 into the third one-way check valve 331 and then to the fine-tuning pressure ball valve 340, which is used to adjust the flow rate and pressure of the liquid.

[0043] The regulated liquid enters the upstream high-precision flowmeter 400 through the inlet conduit 401 on the left side of the upstream high-precision flowmeter 400. After being measured, it enters the data acquisition port set 500 through the outlet conduit 402. Furthermore, the upstream high-precision flowmeter 400 and the downstream high-precision flowmeter 410 are two flowmeters with identical properties. The type of flowmeter can be selected based on the test conditions and is not limited to a specific type. Applicable flowmeter types include, but are not limited to, mass flowmeters, volume flowmeters, differential pressure flowmeters, float flowmeters, turbine flowmeters, electromagnetic flowmeters, vortex flowmeters, and ultrasonic flowmeters.

[0044] The data acquisition port set 500 has four ports, namely a flow meter port 501, an upstream pressure differential port 502, a penetration port 503, and a pressure detection port 504. The flow meter port 501 is connected to the outflow conduit 402, the upstream pressure differential port 502 is connected to the digital pressure differential sensor 700, the penetration port 503 is connected to the concrete penetration device 800 through the penetration inlet conduit 801, and the pressure detection port 504 is connected to the liquid pressure detector 600.

[0045] Downstream data acquisition port set 510 has three ports: a filter port 511, a downstream differential pressure port 512, and a downstream flowmeter port 513. Filter port 511 is connected to the output side of concrete infiltration device 800. An intermediate filter 520 is located between filter port 511 and concrete infiltration device 800. Liquid flows through filter inlet conduit 521 into intermediate filter 520 and then out of filter outlet conduit 522 to filter port 511. Downstream differential pressure port 512 is connected to digital differential pressure sensor 700. Specifically, upstream differential pressure port 502 is connected to the left side of digital differential pressure sensor 700 via high-pressure conduit 701, while downstream differential pressure port 512 is connected to the right side of digital differential pressure sensor 700 via low-pressure conduit 702. Downstream flowmeter port 513 is connected to downstream high-precision flowmeter 410 via downstream flowmeter conduit 411. After measurement, liquid flows back to sealed liquid storage tank 100 via return pipe 112, ensuring liquid circulation within the system.

[0046] Reference Figure 2 and Figure 3The concrete penetration device 800 is suitable for measuring the permeability of concrete specimens 820 of various shapes under different load environment conditions, such as cracked specimens, cracked specimens under load, or permeable concrete specimens 820 of different shapes. The system can perform permeability measurements safely and efficiently. The concrete infiltration device 800 includes a penetration box 810, a liquid inlet pipe 812, a liquid outlet pipe 813, and a liquid collection container 830. The liquid inlet pipe 812 has an inlet liquid separation channel 814, and the liquid outlet pipe 813 has an outlet liquid separation channel 815. The inlet liquid separation channel 814 is connected to a first ball valve 841 through an inlet conduit 840, and the outlet liquid separation channel 815 is connected to a second ball valve 844 through an outlet conduit 845. At the same time, the first ball valve 841 is connected to the left side of the liquid collection container 830 through an upstream conduit 842, and the second ball valve 844 is connected to the right side of the liquid collection container 830 through a downstream conduit 843. A toxic gas filter 831 is also provided above the liquid collection container 830. Liquid can selectively flow into the diverted liquid collection container 830 through the inlet liquid separation channel 814, and the air in the system is removed through the toxic gas filter 831. A concrete specimen 820 is sealed in the penetration box 810 . The side of the concrete specimen 820 is sealed with adhesive tape 816 , and a gap between the penetration box 810 and the concrete specimen 820 is filled with liquid sealant 811 .

[0047] The multi-channel recorder 900 is connected to the upstream high-precision flowmeter 400, the downstream high-precision flowmeter 410, the liquid pressure detector 600, and the digital differential pressure sensor 700 through lines. During the test process, the test data are recorded in the multi-channel recorder 900 and digitally displayed on the computer.

[0048] In this embodiment, all conduits are made of high-pressure-resistant materials, and the connectors or ports are all sealed with high-pressure-resistant threads. High-pressure-resistant materials may include, but are not limited to, hard, corrosion-resistant metals or soft, wire-braided rubber tubing to ensure system reliability and sealing in high-pressure environments.

[0049] The present invention uses a method for using a high-precision concrete liquid penetration test integrated system, comprising the following steps:

[0050] Step 1: Prior to testing, for concrete specimen 820 (e.g., cracked concrete, permeable concrete, or porous concrete), the test area of ​​the specimen should preferably be vacuum saturated for 1 to 2 hours to reduce the time to reach a stable state. Specifically, the test area should be: the cracks of cracked concrete, or the hydraulically exposed areas of permeable concrete or porous concrete.

[0051] Step 2: When installing concrete specimen 820, the test method does not specify the geometric shape of the specimen cross section, allowing for a high degree of flexibility in the design of the penetration box 810. However, it is important to note that the specimen cross section must remain consistent in the direction of liquid flow or height, and that the communication path between the upper and lower pressure surfaces of the specimen must not exhibit lateral leakage. Therefore, the upper and lower pressure surfaces must be sealed from the penetration box 810, forming independent sealed chambers. The distance between the upper and lower pressure surfaces of the specimen is L, and the effective penetration area is AS. To do this, apply tape 816 to the sides of the specimen and cover the penetration areas on the upper and lower end surfaces with tape 816. Place the preliminarily sealed specimen into the penetration box 810 and fill the gap between the penetration box 810 and the specimen with liquid sealant 811. A polymer sealant with elastic properties after drying is preferred. After the sealant has fully cured and developed strength, carefully remove the tape 816 from the upper and lower pressure surfaces to ensure the entire test area is exposed.

[0052] Step 3: To prepare for the test, install the concrete specimen 820 into the system and ensure that the equipment is safely started. The specific steps are as follows:

[0053] Step 3.1: Install the fixed concrete specimen 820 to Figure 2 The concrete penetration device 800 is shown and then installed in the Figure 1 High-precision concrete liquid penetration test integrated system;

[0054] Step 3.2: Check the liquid level of the sealed liquid holding tank 100 to ensure that the liquid level is between 2 / 3 and 4 / 5 of the total height of the tank. The probe 121 of the temperature detector 120 should be placed between 1 / 3 and 2 / 3 of the distance between the liquid level and the bottom of the tank.

[0055] Step 3.3: During the equipment test run, set the self-priming turbine 200's on / off switch and the pressure control button 204 to the preset liquid pressure value; the recommended range is 0.01 to 1 MPa. Open the fine-adjustment pressure ball valve 340 and ensure that the sensor connections are secure. Check the upstream and downstream high-precision flowmeters 400 and 410, the liquid pressure detector 600, and the digital differential pressure sensor 700 to ensure that their data can be effectively collected by the paperless recorder and displayed on the computer 910. Check the piping connections throughout the system to ensure there are no leaks and that they are properly sealed.

[0056] Step 3.4: Gradually increase the reading on the digital display 203 of the self-priming turbine 200 so that the pressure reading on the liquid pressure detector 600 remains below the compressive strength of the concrete specimen 820. When the flow rate reaches % of the range of the upstream high-precision flowmeter 400 or differential pressure sensor, stop increasing the pressure. If the pressure is insufficient, start the air compressor 323 to increase the pressure through the connecting conduit 320, the second one-way check valve 321, the air inlet pipe 322, and the air compressor 323. Maintain this flow state, open the first ball valve 841, and observe for bubbles in the liquid collection container 830. When the bubbles significantly decrease, close the first ball valve 841 to ensure that all gas in the system has been removed. This ensures that the difference in flow rates between the upstream and downstream high-precision flowmeters 410 does not exceed 7% of the reading on the upstream high-precision flowmeter 400. At this point, the system has reached a stable turbulent state. For the dense and poorly permeable concrete specimen 820, the slow exhaust rate may result in a negative pressure in the liquid outlet pipe 813. At this time, the second ball valve 844 can be selectively opened to partially pressurize liquid into the liquid outlet pipe 813 to accelerate the system filling process. After the operation is completed, the second ball valve 844 is closed.

[0057] Step 4: After the system is fully filled with liquid, the test officially begins and data collection begins. Adjust the reading on the digital display 203 of the self-priming turbine 200 so that the differential pressure ΔP of the digital differential pressure sensor 700 or the flow rate Q of the downstream flow meter reaches its minimum value. Activate the temperature measuring instrument 120 and record the temperature T of the test liquid. Gradually increase the pressure control button 204 until the digital differential pressure sensor 700 or the downstream flow meter reaches 80% of its range. The data collection results are {ΔP│ΔP1, ΔP2, ΔP3, …, ΔPn} and {Q│Q1, Q2, Q3, …, Qn}, with ΔPn corresponding to Qn, respectively.

[0058] Step 5: Data processing. According to the temperature T of the test liquid, consult the "Fluid Physical Properties Data Handbook" to determine the liquid viscosity μ and density ρ. Import the collected {ΔP│ΔP1, ΔP2, ΔP3, ..., ΔPn} and {Q│Q1, Q2, Q3, ..., Qn} data into formula (1) for fitting:

[0059]

[0060] The linear coefficient A and nonlinear coefficient B are calculated and substituted into formulas (2) and (3) to calculate the inherent permeability coefficient K. v and inertial permeability coefficient K i :

[0061]

[0062]

[0063] The units of pressure gradient ΔP, linear coefficient A, nonlinear coefficient B and flow rate Q in formula (1) are Pa / m, kg / m5·s, kg / m8 and m3 / s respectively; the units of effective permeable area AS, viscosity μ and L in formulas (2) and (3) are m, Pa·s and m respectively; the water permeability coefficient K v , inertial permeability coefficient K i The units of and density ρ are m2, m and kg / m3 respectively.

[0064] By integrating multiple high-precision sensing and control modules, the present invention enables high-precision, real-time, dynamic monitoring and data collection of the liquid permeability of concrete specimens 820 under varying pressure and temperature conditions. Furthermore, through an innovative closed liquid circulation design, the risk of test liquid leakage is effectively reduced, further ensuring the safety of the experimental environment and the reliability of the test results. Specifically, the entire system design includes, but is not limited to, the following key components: First, a self-priming turbine 200 serves as the core liquid supply and regulation unit. By configuring the self-priming turbine 200 and an intelligent pressure control module, the liquid output is ensured to maintain a stable pressure under various test conditions. Second, a closed liquid holding tank 100 serves as the core unit for liquid storage and temperature control. A temperature detector and tank filter 130 ensure that the liquid remains highly pure before and after entering the test cycle. Furthermore, the tank's liquid level control design effectively prevents liquid overflow. Furthermore, the system includes a high-pressure steel tank 300, which is connected to an air compressor 323 via multiple connection ports. This compressor 323 provides auxiliary pressurization when the liquid pressure is insufficient, ensuring a stable pressure gradient during the liquid permeation process. In terms of data acquisition and monitoring, the present invention utilizes an upstream high-precision flowmeter 400, a downstream high-precision flowmeter 410, and a digital differential pressure sensor 700 for real-time data monitoring and recording. This data is synchronously transmitted to a computer via a multi-channel recorder 900. Combined with dedicated data acquisition and visualization software, operators can observe and analyze changes in various parameters during the test in real time, ensuring high accuracy and stability in observing liquid penetration into concrete under varying operating conditions. In particular, in conjunction with a concrete penetration device 800, the system can accurately measure the penetration performance of concrete specimens 820 of varying shapes and fracture states under varying pressures without compromising the structural integrity of the specimens, further enhancing the system's applicability.

[0065] The above are all preferred embodiments of the present invention and are not intended to limit the scope of protection of the present invention. Among them, the same parts are represented by the same figure numerals. It should be noted that the words "front", "rear", "left", "right", "up" and "down" used in the following description refer to directions in the accompanying drawings, and the words "inside" and "outside" refer to directions toward or away from the geometric center of a specific component, respectively. Therefore, all equivalent changes made according to the structure, shape, and principle of the present invention should be included in the scope of protection of the present invention.

Claims

1. A high-precision concrete liquid penetration test integrated system, characterized in that: The device comprises a sealed liquid holding tank (100), a self-priming turbine (200), a tank body (300), an upstream high-precision flow meter (400), a downstream high-precision flow meter (410), a data acquisition port set (500), a downstream data acquisition port set (510), a liquid pressure detector (600), a digital differential pressure sensor (700), a concrete penetration device (800), and a multi-channel recorder (900); The self-priming turbine (200) is connected to the sealed liquid holding tank (100) via a conduit, and the self-priming turbine (200) is connected to the tank body (300) via a conduit. The tank body (300) is provided with an air compressor (323) and a fine-tuning pressure ball valve (340), and the tank body (300) is connected to an upstream high-precision flow meter (400) via the fine-tuning pressure ball valve (340); The upstream high-precision flow meter (400) is connected to the data acquisition port set (500) via a conduit. The data acquisition port set (500) is provided with no less than four ports and is respectively connected to a liquid pressure detector (600), a digital differential pressure sensor (700), and a concrete penetration device (800) via conduits. The concrete penetration device (800) is also connected to the downstream data acquisition port set (510). The downstream data acquisition port set (510) is provided with no less than three ports, and is connected to the digital differential pressure sensor (700) and the downstream high-precision flow meter (410) via a conduit, and the downstream high-precision flow meter (410) flows back to the sealed liquid holding tank (100) via the conduit; The upstream high-precision flowmeter (400), the downstream high-precision flowmeter (410), the liquid pressure detector (600), and the digital differential pressure sensor (700) are all connected to the multi-channel recorder (900) via lines, and the multi-channel recorder (900) is connected to the computer terminal (910) via lines; The concrete infiltration device (800) comprises a permeation box (810), a liquid inlet pipe (812), a liquid outlet pipe (813) and a liquid collection container (830); the liquid inlet pipe (812) has an inlet liquid separation channel (814); the liquid outlet pipe (813) has an outlet liquid separation channel (815); the inlet liquid separation channel (814) is connected to a first ball valve (841); the outlet liquid separation channel (815) is connected to a second ball valve (844); the first ball valve (841) and the second ball valve (844) are both connected to the liquid collection container (830) via a conduit; the liquid inlet pipe (812) and the liquid outlet pipe (813) are arranged on opposite sides of the permeation box (810); A concrete test piece (820) is sealed in the penetration box (810), a side of the concrete test piece (820) is sealed with adhesive tape (816), and a gap between the penetration box (810) and the concrete test piece (820) is filled with liquid sealant (811).

2. A high-precision concrete liquid penetration test integrated system according to claim 1, characterized in that: The sealed liquid holding box (100) has no less than four connection ports, which are respectively connected to an outflow pipe (110), a pumping and filling pipe (111), a return pipe (112) and a temperature measuring instrument (120).

3. A high-precision concrete liquid penetration test integrated system according to claim 2, characterized in that: The self-priming turbine (200) has a suction end (201) and an output end (202), the outflow pipe (110) is connected to the suction end (201), and the self-priming turbine (200) generates pumping pressure for the liquid and pumps the liquid from the output end (202) to the tank (300).

4. The high-precision concrete liquid penetration test integrated system according to claim 1, characterized in that: The tank body (300) has no less than three connection ports, which are respectively connected to an air compressor (323), a pump inlet pipe (312) and a check pipe (330). The check pipe (330) is provided with a third one-way check valve (331). The other end of the third one-way check valve (331) is connected to an intermediate pipe (332). The other end of the intermediate pipe (332) is connected to a fine-tuning pressure ball valve (340).

5. The high-precision concrete liquid penetration test integrated system according to claim 1, characterized in that: The conduits are made of high-pressure resistant materials, and the joints are connected with high-pressure resistant threaded seals.

6. A method for using the high-precision concrete liquid penetration test integrated system according to any one of claims 1 to 5, characterized in that: The following steps are involved: S1. performing vacuum saturation treatment on the concrete specimen (820) for 1 to 2 hours to reduce the time to reach a stable state, wherein the treated area includes the crack area of ​​the cracked concrete or the hydraulic exposure area of ​​the permeable concrete / porous ordinary concrete; S2. Before the concrete specimen (820) is installed, there is no restriction on the geometric shape of the specimen cross section, but the shape of the specimen cross section must be kept consistent in the direction of liquid flow or the height of the specimen, and the communication path between the upper pressure surface and the lower pressure surface of the specimen must be ensured to prevent lateral leakage. The concrete specimen (820) is initially sealed with adhesive tape (816) on the sides and upper and lower end surfaces using adhesive tape (816). The concrete specimen (820) is then placed in the penetration box (810), and the gap between the penetration box (810) and the specimen is filled with liquid sealant (811). After the sealant dries, the adhesive tape (816) on the upper and lower pressure surfaces is cut off to expose the test area. S3, installing the sealed concrete specimen (820) into the concrete penetration device (800), and installing the device into a high-precision concrete liquid penetration test integrated system; S4. Check the liquid level of the sealed liquid holding box (100) to ensure that the liquid level is between 2 / 3 and 4 / 5 of the total height of the box, and place the probe (121) of the temperature measuring instrument (120) between 1 / 3 and 2 / 3 of the distance between the liquid level and the bottom of the box; S5. Test run the equipment, set the pressure value of the self-priming turbine (200) to 0.01 to 1 MPa, open the fine-tuning pressure ball valve (340), check that the wiring is in good contact, confirm that the data collected by the upstream high-precision flow meter (400) and the downstream high-precision flow meter (410), the liquid pressure detector (600) and the digital differential pressure sensor (700) can be recorded and displayed by the multi-channel recorder (900) and displayed on the computer terminal, check all catheter interfaces to ensure that they are leak-proof and well sealed; S6. Gradually increase the pressure value of the self-priming turbine (200) to ensure that the pressure of the liquid pressure detector (600) is lower than the compressive strength of the concrete specimen (820). When the flow rate reaches 80% of the range of the upstream high-precision flow meter (400) or 80% of the range of the digital differential pressure sensor (700), stop pressurizing. If the pressure is insufficient, increase the pressure through the conduit and the air compressor (323). Maintain the current flow state and observe the bubbles in the liquid collection container (830). Close the first ball valve (841) to effectively remove the gas in the system until the difference in flow rate between the upstream high-precision flow meter (400) and the downstream high-precision flow meter (410) does not exceed 7% of the reading of the upstream high-precision flow meter (400). It is considered that the turbulent state has been reached. For denser specimens, the second ball valve (844) can be selectively opened to accelerate the time for the liquid to fill the entire system. S7. When the liquid fills the entire test system, formal testing and data collection begin; adjust the pressure value of the self-priming turbine (200) so that the reading of the digital differential pressure sensor (700) or the flow rate reading of the downstream high-precision flow meter (410) reaches the minimum; turn on the temperature measuring instrument (120) to record the temperature of the test liquid, and gradually increase the pressure of the self-priming turbine (200) so that the reading of the downstream high-precision flow meter (410) reaches 80% of the range; record the collection results, which are continuous pressure gradient and flow rates {Q│Q1, Q2, Q3, …, Qn}, where the data have isochronous properties; S8. Query the fluid physical property data according to the liquid temperature value to confirm the viscosity and density of the liquid at that temperature; and {Q│Q1,Q2,Q3,…,Qn} are imported into formula (1) for fitting: （1） The linear coefficient A and nonlinear coefficient B are calculated using the formula, and then substituted into formulas (2) and (3) to calculate the inherent permeability coefficient K v and inertial permeability coefficient K i : （2） （3） The pressure gradient in formula (1) The units of linear coefficient A, nonlinear coefficient B and flow rate Q are Pa / m and kg / m respectively. 5 s, kg / m 8 and m 3 / s; effective permeability area A in formula (2) and (3) S The units of viscosity μ and L are m, Pa·s and m respectively; the intrinsic permeability coefficient K v , inertial permeability coefficient K i The units of and density ρ are m 2 , m and kg / m 3 .

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